Cardiovascular Systems Inc - Annual Report: 2011 (Form 10-K)

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K

For the fiscal year ended June 30, 2011

OR

Commission file number: 000-52082

CARDIOVASCULAR SYSTEMS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code:

(651) 259-1600

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨      No  þ

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act.    Yes  ¨      No  þ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  þ    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).     Yes   ¨    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.     ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

(Do not check if a smaller reporting company)

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨      No  þ

As of December 31, 2010, the aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was $154,270,452 based on the closing sale price as reported on the NASDAQ Global Market.

The number of shares of the registrant’s common stock outstanding as of August 30, 2011 was 17,696,121.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the proxy statement for the registrant’s 2011 Annual Meeting of Stockholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this report.

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We make available, free of charge, copies of our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act on our web site, http://www.csi360.com, as soon as reasonably practicable after filing such material electronically or otherwise furnishing it to the Securities and Exchange Commission (“SEC”). We are not including the information on our web site as a part of, or incorporating it by reference into, our Form 10-K.

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PART I

Item 1.    Business.

Special Note Regarding Forward Looking Statements

This report contains plans, intentions, objectives, estimates and expectations that constitute forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which are subject to the “safe harbor” created by those sections. Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “could,” “would,” “expect,” “plans,” “anticipates,” “believes,” “estimates,” “projects,” “predicts,” “potential” and similar expressions intended to identify forward-looking statements. Examples of these statements include, but are not limited to, any statements regarding our future financial performance, results of operations or sufficiency of capital resources to fund our operating requirements, and other statements that are other than statements of historical fact. Our actual results could differ materially from those discussed in these forward-looking statements due to a number of factors, including the risks and uncertainties are described more fully by us in Part I, Item 1A and Part II, Item 7 of this report and in our other filings with the SEC. You should not place undue reliance on these forward-looking statements, which apply only as of the date of this report. You should read this report completely and with the understanding that our actual future results may be materially different from what we expect. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.

Corporate Information

We were incorporated as Replidyne, Inc. in Delaware in 2000. On February 25, 2009, Replidyne, Inc. completed its business combination with Cardiovascular Systems, Inc., a Minnesota corporation (“CSI-MN”), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of November 3, 2008, by and among Replidyne, Responder Merger Sub, Inc., a wholly-owned subsidiary of Replidyne (“Merger Sub”), and CSI-MN (the “Merger Agreement”). Pursuant to the Merger Agreement, Merger Sub merged with and into CSI-MN, with CSI-MN continuing after the merger as the surviving corporation and a wholly-owned subsidiary of Replidyne. At the effective time of the merger, Replidyne changed its name to Cardiovascular Systems, Inc. (“CSI”) and CSI-MN changed its name to CSI Minnesota, Inc. As of immediately following the effective time of the merger, former CSI-MN stockholders owned approximately 80.2% of the outstanding common stock of the combined company, and Replidyne stockholders owned approximately 19.8% of the outstanding common stock of the combined company. Following the merger of Merger Sub with CSI-MN, CSI-MN merged with and into CSI, with CSI continuing after the merger as the surviving corporation. These transactions are referred to herein as the “merger.” Unless the context otherwise requires, all references herein to the “Company,” “CSI,” “we,” “us” and “our” refer to CSI-MN prior to the completion of the merger and to CSI following the completion of the merger and the name change, and all references to “Replidyne” refer to Replidyne prior to the completion of the merger and the name change.

Replidyne was a biopharmaceutical company focused on discovering, developing, in-licensing and commercializing anti-infective products.

CSI-MN was incorporated in Minnesota in 1989. From 1989 to 1997, we engaged in research and development on several different product concepts that were later abandoned. Since 1997, we have devoted substantially all of our resources to the development of the PAD Systems (as hereafter defined) and our Viper line of ancillary products.

Our principal executive office is located at 651 Campus Drive, St. Paul, Minnesota 55112. Our telephone number is (651) 259-1600, and our website is www.csi360.com. The information contained in or accessible through our website is not incorporated by reference into, and should not be considered part of, this Annual Report on Form 10-K.

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We have received federal registration in the U.S. Patent and Trademark Office, or USPTO, of certain marks including “Diamondback 360°”, “CSI”, a first “CSI” logo, a second “CSI” logo, “Lumen Library”, “ViperWire”, “ViperWire Advance”, “Viperslide”, “ViperTrack”, and “ViperCaddy.” We have applied for federal registration with the USPTO of certain marks, including “Predator 360°”, “Stealth 360°”, “Attack the Plaque. Preserve the Media” and “Change Compliance First.” All other trademarks, trade names and service marks appearing in this Form 10-K are the property of their respective owners.

Business Overview

We are a medical device company focused on developing and commercializing minimally invasive treatment solutions for vascular disease. Interventional endovascular treatment of peripheral artery disease, or PAD, is our initial area of focus. PAD is caused by the accumulation of plaque in peripheral arteries, most commonly occurring in the pelvis and legs. PAD is a progressive disease, and, if left untreated, can lead to limb amputation or death.

Our primary products, the Diamondback 360° PAD System (“Diamondback 360°”), Diamondback Predator 360° PAD System (“Predator 360°”) and Stealth 360° PAD System (“Stealth 360°”), are catheter-based platforms capable of treating a broad range of plaque types in leg arteries both above and below the knee and address many of the limitations associated with existing treatment alternatives. We refer to the Diamondback 360°, the Predator 360° and the Stealth 360° collectively in this Annual Report on Form 10-K as the “PAD Systems.” In August 2007, the U.S. Food and Drug Administration, or FDA, granted us 510(k) clearance for the use of the Diamondback 360° as a therapy in patients with PAD. We commenced a limited commercial introduction of the Diamondback 360° in the United States in September 2007 and began a full commercial launch during the quarter ended March 31, 2008. We received 510(k) clearance of the Predator 360° in March 2009 and commenced commercial launch in April 2009. We received 510(k) clearance of the Stealth 360° in March 2011 and commenced a limited market release that same month. We expect to continue this limited release through the first quarter of fiscal 2012, ending September 30, 2011, after which we plan to begin a broader commercial launch. As of June 30, 2011, the PAD Systems had been utilized in more than 50,000 procedures.

We intend to leverage the capabilities of the PAD Systems to expand into the interventional coronary market though we need to complete certain clinical trials and receive FDA approval to do so. In May 2011, we received approval from the FDA to complete enrollment of 429 patients in our ORBIT II clinical trial for a coronary application for the Diamondback 360°, which followed the FDA’s review of data from the first 50 cases in the ORBIT II trial.

In addition to the PAD Systems, we are expanding our product portfolio through internal product development and establishment of business relationships with other medical device companies. We now offer multiple accessory products designed to complement the use of the PAD Systems, and we have entered into a distribution agreement with Asahi Intecc Co., Ltd. to market its peripheral guidewire line in the United States.

Market Overview

Peripheral Artery Disease

PAD is a circulatory problem in which plaque deposits build up on the walls of the arteries, reducing blood flow to the limbs. The most common early symptoms of PAD are pain, cramping or fatigue in the leg or hip muscles while walking. Symptoms may progress to include numbness, tingling or weakness in the leg and, in severe cases, burning or aching pain in the leg, foot or toes while resting. As PAD progresses, additional signs and symptoms occur, including cooling or color changes in the skin of the legs or feet, and sores on the legs or feet that do not heal. If untreated, PAD may lead to critical limb ischemia, a condition in which the amount of oxygenated blood being delivered to the limb is insufficient to keep the tissue alive. Critical limb ischemia often leads to large non-healing ulcers, infections, gangrene and, eventually, limb amputation or death.

PAD affects approximately eight to 12 million people in the United States, as cited by the authors of the PARTNERS study published in the Journal of the American Medical Association in 2001. According to 2007 statistics from the American Heart Association, PAD becomes more common with age and affects approximately

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12% to 20% of the population over 65 years old. An aging population, coupled with increasing incidence of diabetes and obesity, is likely to increase the prevalence of PAD. In many older PAD patients, particularly those with diabetes, PAD is characterized by fibrotic (moderately hard) or calcified (extremely hard) plaque deposits that have not been successfully treated with existing non-invasive treatment techniques. PAD may involve arteries throughout the leg. Arteries above the knee are generally long, straight and relatively wide, while arteries below the knee are shorter and branch into arteries that are progressively smaller in diameter.

Despite the severity of PAD, it remains relatively underdiagnosed. According to an article published in Podiatry Today in 2006, only approximately 2.5 million of the eight to 12 million people in the United States with PAD are diagnosed. Although we believe the rate of diagnosis of PAD is increasing, underdiagnosis continues due to patients failing to display symptoms or physicians misinterpreting symptoms as normal aging. Recent emphasis on PAD education from medical associations, insurance companies and other groups, coupled with publications in medical journals, is increasing physician and patient awareness of PAD risk factors, symptoms and treatment options. The PARTNERS study advocated increased PAD screening by primary care physicians.

Physicians treat a significant portion of the 2.5 million people in the United States who are diagnosed with PAD using medical management, which includes lifestyle changes, such as diet and exercise and drug treatment. For instance, within a reference group of more than 1,000 patients from the PARTNERS study, 54% of the patients with a prior diagnosis of PAD were receiving antiplatelet medication treatment. While medications, diet and exercise may improve blood flow, they do not treat the underlying obstruction and many patients have difficulty maintaining lifestyle changes. Additionally, many prescribed medications are contraindicated, or inadvisable, for patients with heart disease, which often exists in PAD patients. As a result of these challenges, many medically managed patients develop more severe symptoms that require procedural intervention.

Coronary Artery Disease

Based on data from the U.S. Agency for Healthcare Research and Quality, or AHRQ, and the U.S. Centers for Medicare and Medicaid Services, we estimate that approximately 924,000 percutaneous coronary interventions, or PCI, procedures occurred in the United States in 2009. Based on various studies, we believe that more than 25% of PCI procedures involve moderate to severe levels of calcified coronary arteries and could benefit from the use of our device. In addition, based on AHRQ data, we estimate that in 2009 approximately 478,000 coronary artery bypass graft surgeries were performed in the United States. These patients generally have higher rates of calcification and we believe they could benefit from the use of our device.

Our Product

Components of the PAD Systems

The PAD Systems each use a single-use, low-profile catheter that travels over our proprietary ViperWire Advance™ Guide Wire and is powered by either an external control unit (Diamondback 360° or Predator 360°) or a saline infusion pump (Stealth 360°).

Catheter.    The catheter consists of:

ViperWire Advance Guidewire.    The ViperWire Advance is the second generation of the ViperWire. The ViperWire Advance was designed to offer an improved ability to maneuver through tortuous, twisting blood vessels and cross challenging lesions. The PAD Systems travel over this wire to the lesion and operate on this wire.

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ViperSlide Lubricant.    ViperSlide is an exclusive lubricant designed to optimize the smooth operation of the PAD Systems. On April 4, 2011, we entered into a five-year supply agreement with Fresenius Kabi AB (“Fresenius”), pursuant to which Fresenius will manufacture and serve as a single-source supplier of the ViperSlide lubricant through March 2016.

Control Unit.    Used in conjunction with the Diamondback 360° and Predator 360° PAD Systems, the control unit incorporates a touch-screen interface on an easily maneuverable, lightweight pole. Using an external air supply, the control unit regulates air pressure to drive the turbine located in the catheter handle to speeds ranging up to 200,000 revolutions per minute. Saline, delivered by a pumping mechanism on the control unit, bathes the device shaft and crown. The constant flow of saline reduces the risk of heat generation.

Saline Infusion Pump.    Used exclusively with the Stealth 360°, the saline infusion pump mounts directly to the intravenous pole and bathes the devices shaft and crown and provides a power supply for the operation of the catheter.

Technology Overview

The two technologies used in the PAD Systems are plaque modification through differential sanding and plaque removal.

Plaque Modification through Differential Sanding.    The PAD Systems were designed to allow the devices to differentiate between soft compliant and harder diseased arterial tissue. This property is consistent with sanding material such as the diamond grit used in the PAD Systems. The diamond preferentially engages and sands harder material. The PAD Systems also treat soft plaque, which is still harder than a normal vessel wall. Arterial lesions tend to be harder and stiffer than compliant, undiseased tissue, and they often are fibrotic or calcified. The PAD Systems sand the lesion but are designed not to damage more compliant parts of the artery. The mechanism is a function of the centrifugal force generated by the PAD Systems as they rotate. As the crown moves outward, the centrifugal force is offset by the counterforce exerted by the arterial wall. If the tissue is compliant, it should flex away, rather than generating an opposing force that would allow the PAD Systems to engage and sand the wall. Diseased tissue provides resistance and is able to generate an opposing force that allows the PAD Systems to engage and sand the plaque. The sanded plaque is broken down into particles generally smaller than circulating red blood cells that are washed away downstream with the patient’s natural blood flow. Of 36 consecutive experiments that we performed in carbon blocks, animal and cadaver models:

The small particle size minimizes the risk of vascular bed overload, or a saturation of the peripheral vessels with large particles, which may cause slow or reduced blood flow to the foot. We believe that the small size of the particles also allows them to be managed by the body’s natural cleansing of the blood, whereby various types of white blood cells eliminate worn-out cells and other debris in the bloodstream.

Plaque Removal.    The systems operate on the principles of centrifugal force. As the speed of the crown’s rotation increases, it creates centrifugal force, which increases the crown’s orbit and presses the diamond grit coated offset crown against the lesion or plaque, removing a small amount of plaque with each orbit. Normal arteries are compliant; they have the ability to expand and contract as needed to supply blood flow to the legs and feet. Arteries burdened with fibrotic (moderately hard) and/or calcified (extremely hard) plaque often lose their compliance, which makes other therapies such as angioplasty, stenting, surgical bypass and atherectomy problematic. The characteristics of the orbit and the resulting lumen size can be adjusted by modifying three variables:

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We view the PAD Systems as platforms that can be used to develop additional products by adjusting one or more of the speed, crown and shaft variables.

Applications

The PAD Systems can be used to treat plaque in multiple anatomic locations.

Below-the-Knee and Behind-the-Knee Peripheral Artery Disease.    Arteries below and behind the knee have small diameters and may be diffusely diseased, calcified or both, limiting the effectiveness of traditional devices. Behind-the-knee lesions also present challenges if a stent is required because stents frequently fracture due to the forces exerted on the vessels when the knee bends or flexes. The PAD Systems are effective in both diffused and calcified vessels. This was demonstrated in the OASIS trial, where 94.5% of lesions treated with the Diamondback 360° were behind or below the knee.

Above-the-Knee Peripheral Artery Disease.    Plaque in arteries above the knee may also be diffuse, fibrotic and calcific; however, these arteries are longer, straighter and wider than below-the-knee vessels. While effective in difficult-to-treat below-the-knee vessels, and indicated for vessels up to four millimeters in diameter, our products are also being used to treat lesions above the knee.

Coronary Artery Disease.    Given the many similarities between peripheral and coronary artery disease, we have developed a modified version of the Diamondback 360° to treat coronary arteries. We have conducted numerous bench studies, pre-clinical animal studies, and our ORBIT I 50-patient human clinical study to evaluate the Diamondback 360° in coronary artery disease. A coronary application requires us to conduct a clinical trial and file a premarket application (PMA) and obtain approval from the FDA. We participated in three pre-investigational device exemption, or IDE, meetings with the FDA and completed the human feasibility portion of a coronary trial in the summer of 2008 in India, enrolling 50 patients. The FDA agreed to accept the data from the India trial to support an IDE submission. The FDA granted unconditional approval in April 2010 to begin the ORBIT II coronary study in the United States. In May 2011, we received approval from the FDA to complete enrollment of 429 patients in our ORBIT II clinical trial for a coronary application for the Diamondback 360°, which followed the FDA’s review of data from the first 50 cases in the ORBIT II trial.

Our Solution

The PAD Systems represent an innovative approach to the treatment of PAD that provides physicians and patients with a procedure that addresses many of the limitations of traditional treatment alternatives. The PAD Systems each use single-use catheters that incorporate a flexible drive shaft with an offset diamond grit coated crown. Physicians position the crown at the site of an arterial plaque-containing lesion and remove the plaque by positioning the crown to orbit against it, creating a smooth lumen, or channel, in the vessel. The PAD Systems are designed to differentiate between hard plaque and soft, compliant arterial tissue, a concept that we refer to as “differential sanding.”

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Normal arteries are compliant; they have the ability to expand and contract as needed to supply blood flow to the legs and feet. Arteries burdened with fibrotic (moderately hard) and/or calcified (extremely hard) plaque due to PAD lose their compliance which makes other therapies such as angioplasty, stenting, surgical bypass and atherectomy problematic. The PAD Systems sand plaque into small particles and restore both blood flow and vessel compliance. The particles created by the PAD Systems are generally smaller than red blood cells and are carried away by the bloodstream. The small size of the particles avoids the need for plaque collection reservoirs. The PAD Systems can typically treat the diseased arteries with less than two to three minutes of sanding time, potentially reducing the overall procedure time.

We believe that the PAD Systems offer the following key benefits:

Strong Safety Profile

Proven Efficacy

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Ease of Use

Treatment Area

Cost and Time Efficient Procedure

Our Strategy

Our goal is to be the leading provider of minimally invasive solutions for the treatment of vascular disease. The key elements of our strategy include:

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We are continuing to evaluate internal product development to further expand our portfolio of PAD treatment solutions.

In addition to adding to our product portfolio through internal development efforts, we intend to continue to explore the acquisition of other product lines, technologies or companies that may leverage our sales force or complement our strategic objectives. We plan to continue to evaluate distribution agreements, licensing transactions, other strategic partnerships, and the financial viability of marketing the PAD Systems internationally.

Clinical Trials and Studies for Our Products

We are committed to providing relevant clinical evidence to allow physicians to select and utilize the best treatment options for their patients. We have conducted twelve clinical trials to demonstrate the safety and efficacy of the PAD Systems in treating PAD, enrolling a total of 3,746 patients in our PAD I and PAD II pilot trials, OASIS pivotal trial, OASIS LT study demonstrating long term durability of the Diamondback 360º and the CONFIRM DIAMONDBACK, CONFIRM PREDATOR and CONFIRM OUTFLOW Post-Market Registries. In

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addition, we have also completed enrollment in the CALCIUM 360° and COMPLIANCE 360° post-market, randomized feasibility studies that further differentiate the performance of the Diamondback 360° and Predator 360° from conventional balloon angioplasty.

To demonstrate the safety and effectiveness of the Diamondback 360° for use in coronary arteries we also completed the ORBIT I coronary clinical trial in India in 2009. In 2010, we began the ORBIT II pivotal study in the United States, evaluating the use of the Diamondback 360° in coronary arteries.

Metrics Used in PAD Trials

The common metrics used to evaluate plaque modification and removal devices for PAD include:

The common metrics used to evaluate atherectomy devices for PAD include:

Inclusion criteria for trials often limit size of lesion and severity of disease, as measured by the Rutherford Class, which utilizes a scale of I to VI, with I being mild and VI being most severe, and the ABI.

PAD Feasibility Trials

The first clinical trial was a two-site, 17-patient feasibility clinical trial in Europe, referred to as PAD I, which began in March 2005. Patients enrolled in the trial had lesions that were less than 10 cm in length in

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arteries between 1.5 mm and 6.0 mm in diameter, with Rutherford Class scores of IV or lower. Patients were evaluated at the time of the procedure and at 30 days following treatment. The purpose of PAD I was to obtain the first human clinical experience and evaluate the safety of the Diamondback 360°. This was determined by estimating the cumulative incidence of patients experiencing one or more SAEs within 30 days post-treatment.

The results of PAD I confirmed that the Diamondback 360° was safe and established that the Diamondback 360° could be used to treat vessels in the range of 1.5 mm to 4.0 mm, which are found primarily below the knee. PAD I also showed that removal of plaque could be accomplished and the resulting device-to-lumen ratio was approximately 1.0 to 2.0. The SAE rate in PAD I was 6% (one of 17 patients).

After being granted the CE Mark in May 2005, a 66-patient European clinical trial, PAD II, was initiated at seven sites, in August 2005. All patients had stenosis in vessels below the femoral artery of between 1.5 mm and 4.0 mm in diameter, with at least 50% blockage. The primary objectives of this study were to evaluate the acute (30 days or less) risk of experiencing an SAE post procedure and provide evidence of device effectiveness. Effectiveness was confirmed angiographically and based on the percentage of absolute plaque reduction.

The PAD II results demonstrated safe and effective debulking in vessels with diameters ranging from 1.5 mm to 4.0 mm with a mean absolute plaque reduction of 55%. The SAE rate in PAD II was 9% (six of 66 patients), which did not differ significantly from existing non-invasive treatment options.

OASIS Pivotal Trial

An IDE was approved in September 2005 to begin our pivotal United States trial, OASIS. OASIS was a 124-patient, 20-center, prospective trial that began enrollment in January 2006.

Patients included in the trial had:

The primary efficacy study endpoint was absolute plaque reduction of the target lesions from baseline to immediately post procedure. The primary safety endpoint was the cumulative incidence of SAEs at 30 days.

In the OASIS trial, 94.5% of lesions treated were behind or below the knee, an area where lesions have traditionally gone untreated until they require bypass surgery or amputation. Of the lesions treated in OASIS, 55% were comprised of calcified plaque, which presents a challenge to proper expansion and apposition of balloons and stents, and 48% were diffuse, or greater than 3 cm in length, which typically requires multiple balloon expansions or stent placements. Competing plaque removal devices are often ineffective with these difficult to treat lesions.

The average time of treatment in the OASIS trial was three minutes per lesion, which compares favorably to the treatment time required by other plaque removal devices. The following table is a summary of the OASIS trial results:

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CLEAR 360° Study

We conducted the CLEAR 360° study to evaluate the incidence of clinically significant hemolysis associated with orbital atherectomy used to treat severe peripheral arterial disease. This study enrolled 31 patients at four U.S. medical centers and was completed in 2009. This trial concluded that there was no clinically significant hemolysis after orbital atherectomy.

OASIS Long-Term Study

In 2009 we completed a retrospective study evaluating the long-term results of 64 patients from the pivotal OASIS trial. Outcomes were analyzed out to a mean of 29 months and include limb salvage rate, TLR rate and ABI. TLR, or reintervention in the originally treated lesion, was 13.6%. A 100% limb salvage rate was maintained. ABI scores remained significantly improved. This 29 month data of OASIS patients adds to our confidence in the safety and efficacy of the Diamondback 360°.

Post-Market Feasibility Studies

In May 2010, enrollment was completed in the COMPLIANCE 360° clinical trial, the first of two PAD post-market studies initiated in calendar 2009. This prospective, randomized, multi-center study evaluated the clinical and economic benefits of modifying plaque to change large vessel compliance above the knee with the Diamondback 360° or Predator 360°. The study compared the performance of the Diamondback 360° or Predator 360°, plus low-pressure balloon inflation, if desired, with that of high-pressure balloon inflation alone. Fifty patients were enrolled at nine U.S. medical centers. The results of this trial showed that the Diamondback 360° or Predator 360° can achieve superior results in treating calcified plaque by improving lesion compliance through differential sanding, without the need for stent placement. Trial results with a p-value of less than 0.0001 statistically demonstrated the success rate in the Diamondback 360° or Predator 360° arm of the trial had a procedural success rate of 360% greater than in the balloon arm of the trial and required 91% less bailout stenting. The six month study results will be presented as an oral presentation at the Transcatheter Cardiovascular Therapeutics, or TCT, conference in November 2011 in San Francisco, CA. Patients will complete their 12 month follow up by the end of September 2011. Twenty four months of data will continue to be collected.

In April 2010, enrollment was completed in the CALCIUM 360^° study, a prospective, randomized, multi-center study comparing the effectiveness of the Diamondback 360° and Predator 360° to balloon angioplasty in treating calcified lesions below the knee. Calcified plaque exists in about 75 percent of lesions below the knee. Fifty patients were enrolled at eight U.S. medical centers. Six-month results showed orbital treatment outperformed balloon angioplasty. A key finding was that by modifying calcified lesions first, the Diamondback 360° and Predator 360° allow use of a lower-pressure adjunctive balloon therapy, reducing the need for bailout stenting with anticipated improved longer-term patient outcomes. Orbital treatment outperformed balloon angioplasty on the primary endpoint of device success (less than or equal to 30% restenosis with no dissection C-F) with 92.6% in the Diamondback 360° and Predator 360° arm of the trial versus 78.8% in the balloon arm of the trial. These results will be reported as an abstract at the San Francisco TCT conference. Patients will complete their 12 month follow up by the end of September 2011. Twenty four months of data will continue to be collected.

CONFIRM Post-Market Clinical Registry Series

We are conducting the CONFIRM Post-Market Clinical Registry Series, which will further evaluate acute and economic parameters related to the use of the PAD Systems. The CONFIRM Series currently consists of three registries: CONFIRM I DIAMONDBACK, CONFIRM II PREDATOR, and CONFIRM III OUTFLOW.

Enrollment of 728 patients in the CONFIRM I DIAMONDBACK Post-Market Registry was completed in March 2010. In this prospective registry, 1,138 lesions were treated by 84 investigators at 57 medical centers with the Diamondback 360°. Patient characteristics were as follows: 81.6% were smokers, 60.0% were diabetic, and 89.7% had hypertension. Lesions treated were above the knee (46.5%), behind the knee (17.5%), and below the knee (36.0%). Lesions were long and calcified. Lesions were treated with the Diamondback 360° followed by

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low pressure balloon angioplasty, if desired. An average residual stenosis of 10.5% was achieved following treatment, which is consistent with that, achieved in PAD I, PAD II, and OASIS. Bail-out stenting, or stenting required due to tears in the vessel wall, occurred in 2.2% of lesions, which is also consistent with the 2.5% reported in OASIS. This is lower than the 35% to 40% bail-out stent rate reported in the literature for patients treated with high pressure balloon angioplasty alone in this type of challenging patient population.

Enrollment of 1,145 patients in the prospective CONFIRM II PREDATOR Post-Market Registry was completed December 2010. The CONFIRM II PREDATOR evaluated clinical performance of the Predator 360°. Data on acute clinical performance and short-term economic parameters were collected during this study. An abstract will be presented at the San Francisco TCT conference.

Data from CONFIRM DIAMONDBACK and PREDATOR registries were used to design the CONFIRM III OUTFLOW registry. This is the third study in the CONFIRM series to further evaluate acute procedural outcomes and economic parameters associated with use of the PAD Systems. Enrollment of 1,275 patients in the CONFIRM III OUTFLOW Post-Market Registry was completed June 2011. Data will be reported at future scientific conferences.

ORBIT I Coronary Feasibly Safety Study

The ORBIT I trial, a 50-patient study in India, was completed in 2009. This feasibility trial investigated the safety of the Diamondback 360° in treating calcified coronary artery lesions. The safety was evaluated by six-months MACE rate. Study results showed the device success for the study was 100%. Six months MACE rate was 8%. The ORBIT I trial confirmed that the OAS is safe in treating subjects with de novo calcified coronary artery disease. The 6 month results will be presented at the TCT conference in 2011.

ORBIT II Coronary IDE Study

To market the Diamondback 360° in the United States for use in the coronary arteries, we are required to conduct further clinical trials and obtain premarket approval from the FDA. In May 2010, the IDE was FDA approved and we began the ORBIT II pivotal clinical trial. This trial plans to enroll 429 patients in up to 50 U.S. investigational centers to evaluate the safety and effectiveness of the Diamondback 360° in treating severely calcified coronary lesions. In May 2011, we received approval from the FDA to complete enrollment of 429 patients in our ORBIT II clinical trial for a coronary application for the Diamondback 360°, which followed the FDA’s review of data from the first 50 cases in the ORBIT II trial.

Sales and Marketing

We market and sell the PAD Systems through a direct sales force in the United States. While we sell directly to hospitals and office based laboratories, we have targeted sales and marketing efforts to interventional cardiologists, vascular surgeons and interventional radiologists with experience using similar catheter-based procedures, such as angioplasty, stenting, and cutting or laser atherectomy. Physician referral programs and peer-to-peer education are other key elements of our sales strategy. Patient referrals come from general practitioners, podiatrists, nephrologists and endocrinologists.

We target our marketing efforts to practitioners through physician education, medical conferences, seminars, peer reviewed journals and marketing materials. Our sales and marketing program focuses on:

We are not marketing our products internationally; however, we will continue to evaluate international opportunities.

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We executed a Purchasing Agreement with HealthTrust Purchasing Group, L.P., or HPG, that became effective on July 15, 2011. HPG acts as a group purchasing organization for the healthcare providers belonging to HPG as participants. Under the Purchasing Agreement, all of HPG’s participants located in the United States or its territories are eligible to purchase the PAD Systems and related products at prices set forth in the Purchasing Agreement. HPG has agreed not to contract with more than one alternative supplier from which participants may purchase products comparable to ours under the agreement. During the term of the agreement, we have agreed to not solicit any HPG participant to enter into a separate agreement for our products.

Research and Development

Our research and development efforts are focused in the development of products to penetrate our three key target markets: below and behind-the-knee, above-the-knee and coronary vessels. Research and development projects include the development of electric versions of the PAD Systems, shaft designs, crown designs, and PAD and coronary clinical trials. Research and development expenses for fiscal 2011, fiscal 2010 and fiscal 2009 were $8.9 million, $10.3 million and $14.7 million, respectively.

Manufacturing

We use internally-manufactured and externally-sourced components to manufacture the PAD Systems. Most of the externally-sourced components are available from multiple suppliers; however, a few key components, including the diamond grit coated crown, micro motors, and printed circuit board assemblies, are single sourced. We assemble the shaft, crown and handle components on-site, and test, pack, seal and label the finished assembly before sending the packaged product to a contract sterilization facility. Upon return from the sterilizer, product is held in inventory prior to shipping to our customers.

Our manufacturing facility in Minnesota, including the shaft manufacturing and the controlled-environment assembly areas, are equipped to accommodate approximately 30,000 devices per shift annually. It also has storage capacity for approximately 8,000 devices and 50 control units. As the control unit becomes obsolete, we will convert our storage space for use with the Stealth 360° PAD System.

Our Pearland, Texas facility is 46,000 square feet and includes a custom-built clean room and production space for future expansion of value-add processes, including machining and electronics assembly. The facility, when it becomes fully staffed and equipped, will have the capacity to produce approximately 75,000 devices per shift annually. This facility has finished goods storage capacity for greater than 15,000 devices of the PAD Systems and other accessory products and over 500 Stealth 360° saline infusion pumps.

We are registered with the FDA as a medical device manufacturer. We have opted to maintain quality assurance and quality management certifications to enable us to market our products in the member states of the European Union, the European Free Trade Association and countries that have entered into Mutual Recognition Agreements with the European Union. We are ISO 13485:2003 certified, and our renewal is due by December 2012. During the time of commercialization, we have had two minor instances of recall, involving one single lot of Diamondback 360° devices (eight units), and two boxes of ViperWires (ten wires), related to “Use By” date labeling issues. While these recalls were reported to the FDA, according to regulations, they did not provide a risk to patient safety. A third recall, initiated in 2009 and completed in 2010, involved the ViperSheath, which is owned and manufactured by Thomas Medical Products. As the distributor for the ViperSheath, we were required to recall all unused units from our customers and return them to Thomas Medical Products. All of the unused ViperSheaths were captured and subsequently destroyed by Thomas Medical Products, with FDA observance.

Third-Party Reimbursement and Pricing

Third-party payors, including private insurers, and government insurance programs, such as Medicare and Medicaid, pay for a significant portion of patient care provided in the United States. The single largest payor in the United States is the Medicare program, a federal governmental health insurance program administered by the Centers for Medicare and Medicaid Services, or CMS. Medicare covers certain medical care expenses for eligible elderly and disabled individuals, including a large percentage of the population with PAD who could be

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treated with the PAD Systems. In addition, private insurers often follow the coverage and reimbursement policies of Medicare. Consequently, Medicare’s coverage and reimbursement policies are important to our operations.

CMS has established Medicare reimbursement codes describing atherectomy products and procedures using atherectomy products, and many private insurers follow these policies. We believe that physicians and hospitals that treat PAD with the PAD Systems will generally be eligible to receive reimbursement from Medicare and private insurers for the cost of the single-use catheter and the physician’s services.

The continued availability of insurance coverage and reimbursement for newly approved medical devices is uncertain. The commercial success of our products in both domestic and international markets will be dependent on whether third-party coverage and reimbursement is available for patients that use our products. Medicare, Medicaid, health maintenance organizations and other third-party payors are increasingly attempting to contain healthcare costs by limiting both coverage and the level of reimbursement of new medical devices, and, as a result, they may not continue to provide adequate payment for our products. To position our device for acceptance by third-party payors, we may have to agree to a lower net sales price than we might otherwise charge. The continuing efforts of governmental and commercial third-party payors to contain or reduce the costs of healthcare may limit our revenue.

In some foreign markets, pricing and profitability of medical devices are subject to government control. In the United States, we expect that there will continue to be federal and state proposals for similar controls. Also, the trends toward managed healthcare in the United States and legislation intended to reduce the cost of government insurance programs could significantly influence the purchase of healthcare services and products and may result in lower prices for our products or the exclusion of our products from reimbursement programs.

Competition

The medical device industry is highly competitive, subject to rapid change and significantly affected by new product introductions and other activities of industry participants. The PAD Systems compete with a variety of other products or devices for the treatment of vascular disease, including stents, balloon angioplasty catheters and atherectomy catheters, as well as products used in vascular surgery. Large competitors in the stent and balloon angioplasty market segments include Abbott Laboratories, Boston Scientific, Cook Medical, Johnson & Johnson and Medtronic. We also compete against manufacturers of atherectomy catheters including, among others, Covidien, Spectranetics, Boston Scientific and Pathway Medical Technologies, as well as other manufacturers that may enter the market due to the increasing demand for treatment of vascular disease. Other competitors include pharmaceutical companies that manufacture drugs for the treatment of mild to moderate PAD and companies that provide products used by surgeons in peripheral bypass procedures. We are not aware of any competing catheter systems either currently on the market or in development that also use an orbital motion to create lumens larger than the catheter itself.

Because of the size of the peripheral opportunities, competitors and potential competitors have historically dedicated significant resources to aggressively promote their products. We believe that the PAD Systems compete primarily on the basis of:

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Patents and Intellectual Property

We rely on a combination of patent, copyright and other intellectual property laws, trade secrets, nondisclosure agreements and other measures to protect our proprietary rights. As of July 31, 2011, we held 21 issued U.S. patents and have 31 U.S. patent applications pending, as well as 63 issued or granted foreign patents and 98 foreign patent applications, each of which corresponds to aspects of our U.S. patents and applications. Our issued U.S. patents expire between 2011 and 2027, and our most important patent, U.S. Patent No. 6,494,890, is due to expire in 2017. Our issued patents and patent applications relate primarily to the design and operation of certain interventional atherectomy devices, including the PAD Systems. These patents and applications include claims covering key aspects of certain rotational atherectomy devices, including the design, manufacture and therapeutic use of certain atherectomy abrasive heads, drive shafts, control systems, handles and couplings. As we continue to research and develop our atherectomy technology, we intend to file additional U.S. and foreign patent applications related to the design, manufacture and therapeutic uses of atherectomy devices. In addition, we hold ten registered U.S. trademarks, six registered marks in Europe, five registered marks in Canada, and three U.S. trademark applications pending.

We also rely on trade secrets, technical know-how and continuing innovation to develop and maintain our competitive position. We seek to protect our proprietary information and other intellectual property by requiring our employees, consultants, contractors, outside scientific collaborators and other advisors to execute non-disclosure and assignment of invention agreements on commencement of their employment or engagement. Agreements with our employees also forbid them from bringing the proprietary rights of third parties to us. We also require confidentiality or material transfer agreements from third parties that receive our confidential data or materials.

Government Regulation of Medical Devices

Governmental authorities in the United States at the federal, state and local levels and in other countries extensively regulate, among other things, the development, testing, manufacture, labeling, promotion, advertising, distribution, marketing and export and import of medical devices such as the PAD Systems.

Failure to obtain approval to market our products under development and to meet the ongoing requirements of these regulatory authorities could prevent us from marketing and continuing to market our products.

United States

The Federal Food, Drug, and Cosmetic Act, or FDCA, and the FDA’s implementing regulations govern medical device design and development, preclinical and clinical testing, premarket clearance or approval, registration and listing, manufacturing, labeling, storage, advertising and promotion, sales and distribution, export and import, and post-market surveillance. Medical devices and their manufacturers are also subject to inspection by the FDA. The FDCA, supplemented by other federal and state laws, also provides civil and criminal penalties for violations of its provisions. We manufacture and market medical devices that are regulated by the FDA, comparable state agencies and regulatory bodies in other countries.

Unless an exemption applies, each medical device we wish to commercially distribute in the United States will require marketing authorization from the FDA prior to distribution. The two primary types of FDA marketing authorization are premarket notification (also called 510(k) clearance) and premarket approval (also called PMA approval). The type of marketing authorization applicable to a device — 510(k) clearance or PMA approval — is generally linked to classification of the device. The FDA classifies medical devices into one of three classes (Class I, II or III) based on the degree of risk FDA determines to be associated with a device and the extent of control deemed necessary to ensure the device’s safety and effectiveness. Devices requiring fewer controls because they are deemed to pose lower risk are placed in Class I or II. Class I devices are deemed to pose the least risk and are subject only to general controls applicable to all devices, such as requirements for device labeling, premarket notification, and adherence to the FDA’s current good manufacturing practice requirements, as reflected in its Quality System Regulation, or QSR. Class II devices are intermediate risk devices that are subject to general controls and may also be subject to special controls such as performance standards, product-specific guidance documents, special labeling requirements, patient registries or postmarket

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surveillance. Class III devices are those for which insufficient information exists to assure safety and effectiveness solely through general or special controls, and include life-sustaining, life-supporting or implantable devices, and devices not “substantially equivalent” to a device that is already legally marketed.

Most Class I devices and some Class II devices are exempted by regulation from the 510(k) clearance requirement and can be marketed without prior authorization from FDA. Class I and Class II devices that have not been so exempted are eligible for marketing through the 510(k) clearance pathway. By contrast, devices placed in Class III generally require PMA approval prior to commercial marketing. The PMA approval process is generally more stringent, time-consuming and expensive than the 510(k) clearance process.

510(k) Clearance.    To obtain 510(k) clearance for a medical device, an applicant must submit a premarket notification to the FDA demonstrating that the device is “substantially equivalent” to a predicate device legally marketed in the United States. A device is substantially equivalent if, with respect to the predicate device, it has the same intended use and has either (i) the same technological characteristics or (ii) different technological characteristics and the information submitted demonstrates that the device is as safe and effective as a legally marketed device and does not raise different questions of safety or effectiveness. A showing of substantial equivalence sometimes, but not always, requires clinical data. Generally, the 510(k) clearance process can exceed 90 days and may extend to a year or more.

After a device has received 510(k) clearance for a specific intended use, any modification that could significantly affect its safety or effectiveness, such as a significant change in the design, materials, method of manufacture or intended use, will require a new 510(k) clearance or PMA approval (if the device as modified is not substantially equivalent to a legally marketed predicate device). The determination as to whether new authorization is needed is initially left to the manufacturer; however, the FDA may review this determination to evaluate the regulatory status of the modified product at any time and may require the manufacturer to cease marketing and recall the modified device until 510(k) clearance or PMA approval is obtained. The manufacturer may also be subject to significant regulatory fines or penalties.

We received 510(k) clearance for use of the Diamondback 360° as a therapy in patients with PAD in the United States on August 22, 2007. We received additional 510(k) clearances for the control unit used with the Diamondback 360° on October 25, 2007 and for the solid crown version of the Diamondback 360° on November 9, 2007. We were granted 510(k) clearance of the Predator 360° in March 2009 and Stealth 360° in March 2011.

Premarket Approval.    A PMA application requires the payment of significant user fees and must be supported by valid scientific evidence, which typically requires extensive data, including technical, preclinical, clinical and manufacturing data, to demonstrate to the FDA’s satisfaction the safety and efficacy of the device. A PMA application must also include a complete description of the device and its components, a detailed description of the methods, facilities and controls used to manufacture the device, and proposed labeling. After a PMA application is submitted and found to be sufficiently complete, the FDA begins an in-depth review of the submitted information. During this review period, the FDA may request additional information or clarification of information already provided. Also during the review period, an advisory panel of experts from outside the FDA may be convened to review and evaluate the application and provide recommendations to the FDA as to the approvability of the device. In addition, the FDA will conduct a pre-approval inspection of the manufacturing facility to ensure compliance with the FDA’s Quality System Regulations, or QSR, which requires manufacturers to follow design, testing, control, documentation and other quality assurance procedures.

FDA review of a PMA application is required by statute to take no longer than 180 days, although the process typically takes significantly longer, and may require several years to complete. The FDA can delay, limit or deny approval of a PMA application for many reasons, including:

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If the FDA evaluations of both the PMA application and the manufacturing facilities are favorable, the FDA will either issue an approval letter or an approvable letter, which usually contains a number of conditions that must be met in order to secure final approval of the PMA. When and if those conditions have been fulfilled to the satisfaction of the FDA, the agency will issue a PMA approval letter authorizing commercial marketing of the device for certain indications. If the FDA’s evaluation of the PMA or manufacturing facilities is not favorable, the FDA will deny approval of the PMA or issue a not approvable letter. The FDA may also determine that additional clinical trials are necessary, in which case the PMA approval may be delayed for several months or years while the trials are conducted and then the data submitted in an amendment to the PMA. Even if a PMA application is approved, the FDA may approve the device with an indication that is narrower or more limited than originally sought. The agency can also impose restrictions on the sale, distribution or use of the device as a condition of approval, or impose post approval requirements such as continuing evaluation and periodic reporting on the safety, efficacy and reliability of the device for its intended use.

New PMA applications or PMA supplements may be required for modifications to the manufacturing process, labeling, device specifications, materials or design of a device that is approved through the PMA process. PMA approval supplements often require submission of the same type of information as an initial PMA application, except that the supplement is limited to information needed to support any changes from the device covered by the original PMA application and may not require as extensive clinical data or the convening of an advisory panel.

We are currently enrolling patients in an FDA approved Investigational Device Exemption (IDE) trial to support a PMA to use the Diamondback 360° as a therapy in treating patients with coronary artery disease. The FDA granted unconditional approval in April 2010 to begin the ORBIT II coronary trial in the United States. This pivotal trial is set up in two phases; Phase I allows us to enroll up to 100 patients at as many as 50 U.S. sites, Phase II allows us to expand the trial to the full complement of 429 patients. The FDA granted us approval to move to Phase II in May of 2011.

Clinical Trials.    Clinical trials are almost always required to support a PMA application and are sometimes required for a 510(k) clearance. These trials generally require submission of an application for an IDE to the FDA. The IDE application must be supported by appropriate data, such as animal and laboratory testing results, showing that it is safe to test the device in humans and that the testing protocol is scientifically sound. The IDE application must be approved in advance by the FDA for a specified number of patients, unless the product is deemed a non-significant risk device and eligible for more abbreviated IDE requirements. Generally, clinical trials for a significant risk device may begin once the IDE application is approved by the FDA and the study protocol and informed consent are approved by appropriate institutional review boards at the clinical trial sites.

FDA approval of an IDE allows clinical testing to go forward but does not bind the FDA to accept the results of the trial as sufficient to prove the product’s safety and efficacy, even if the trial meets its intended success criteria. With certain exceptions, changes made to an investigational plan after an IDE is approved must be submitted in an IDE supplement and approved by FDA (and by governing institutional review boards when appropriate) prior to implementation.

All clinical trials must be conducted in accordance with regulations and requirements collectively known as good clinical practice. Good clinical practices include the FDA’s IDE regulations, which describe the conduct of clinical trials with medical devices, including the recordkeeping, reporting and monitoring responsibilities of sponsors and investigators, and labeling of investigation devices. They also prohibit promotion, test marketing or commercialization of an investigational device and any representation that such a device is safe or effective for the purposes being investigated. Good clinical practices also include the FDA’s regulations for institutional review board approval and for protection of human subjects (such as informed consent), as well as disclosure of financial interests by clinical investigators.

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Required records and reports are subject to inspection by the FDA. The results of clinical testing may be unfavorable or, even if the intended safety and efficacy success criteria are achieved, may not be considered sufficient for the FDA to grant approval or clearance of a product. The commencement or completion of any clinical trials may be delayed or halted, or be inadequate to support approval of a PMA application or clearance of a premarket notification for numerous reasons, including, but not limited to, the following:

Continuing Regulation.    After a device is approved and placed in commercial distribution, numerous regulatory requirements continue to apply. These include:

In addition, the FDA may require a company to conduct postmarket surveillance studies or order it to establish and maintain a system for tracking its products through the chain of distribution to the patient level.

Failure to comply with applicable regulatory requirements, including those applicable to the conduct of clinical trials, can result in enforcement action by the FDA, which may lead to any of the following sanctions:

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We and our contract manufacturers, specification developers and suppliers are also required to manufacture our products in compliance with current Good Manufacturing Practice, or GMP, requirements set forth in the QSR.

The QSR requires a quality system for the design, manufacture, packaging, labeling, storage, installation and servicing of marketed devices, and includes extensive requirements with respect to quality management and organization, device design, buildings, equipment, purchase and handling of components, production and process controls, packaging and labeling controls, device evaluation, distribution, installation, complaint handling, servicing and record keeping. The FDA enforces the QSR through periodic announced and unannounced inspections that may include the manufacturing facilities of subcontractors. If the FDA believes that we or any of our contract manufacturers or regulated suppliers is not in compliance with these requirements, it can shut down our manufacturing operations, require recall of our products, refuse to clear or approve new marketing applications, institute legal proceedings to detain or seize products, enjoin future violations or assess civil and criminal penalties against us or our officers or other employees. Any such action by the FDA would have a material adverse effect on our business.

Fraud and Abuse

Our operations will be directly, or indirectly through our customers, subject to various state and federal fraud and abuse laws, including, without limitation, the FDCA, federal Anti-Kickback Statute and False Claims Act. These laws may impact, among other things, our proposed sales, marketing, and education programs. In addition, these laws require us to screen individuals and other companies, suppliers and vendors in order to ensure that they are not “debarred” by the federal government and therefore prohibited from doing business in the healthcare industry.

The federal Anti-Kickback Statute prohibits persons from knowingly and willfully soliciting, offering, receiving or providing remuneration, directly or indirectly, in exchange for or to induce either the referral of an individual, or the furnishing or arranging for a good or service, for which payment may be made under a federal healthcare program such as the Medicare and Medicaid programs. Several courts have interpreted the statute’s intent requirement to mean that if any one purpose of an arrangement involving remuneration is to induce referrals of federal healthcare covered business, the statute has been violated. The Anti-Kickback Statute is broad and prohibits many arrangements and practices that are lawful in businesses outside of the healthcare industry. Many states have also adopted laws similar to the federal Anti-Kickback Statute, some of which apply to the referral of patients for healthcare items or services reimbursed by any source, not only the Medicare and Medicaid programs.

The federal False Claims Act prohibits persons from knowingly filing or causing to be filed a false claim to, or the knowing use of false statements to obtain payment from, the federal government. Various states have also enacted laws modeled after the federal False Claims Act.

In addition to the laws described above, the Health Insurance Portability and Accountability Act of 1996 created two new federal crimes: healthcare fraud and false statements relating to healthcare matters. The healthcare fraud statute prohibits knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private payors. The false statements statute prohibits knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services.

Voluntary industry codes, federal guidance documents and a variety of state laws address the tracking and reporting of marketing practices relative to gifts given and other expenditures made to doctors and other

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healthcare professionals. In addition to impacting our marketing and educational programs, internal business processes will be affected by the numerous legal requirements and regulatory guidance at the state, federal and industry levels.

International Regulation

International sales of medical devices are subject to foreign government regulations, which may vary substantially from country to country. The time required to obtain approval in a foreign country may be longer or shorter than that required for FDA approval and the requirements may differ. For example, the primary regulatory environment in Europe with respect to medical devices is that of the European Union, which includes most of the major countries in Europe. Other countries, such as Switzerland, have voluntarily adopted laws and regulations that mirror those of the European Union with respect to medical devices. The European Union has adopted numerous directives and standards regulating the design, manufacture, clinical trials, labeling and adverse event reporting for medical devices. Devices that comply with the requirements of a relevant directive will be entitled to bear the CE conformity marking, indicating that the device conforms to the essential requirements of the applicable directives and, accordingly, can be commercially distributed throughout the European Union, although actual implementation of these directives may vary on a country-by-country basis. The method of assessing conformity varies depending on the class of the product, but normally involves a combination of submission of a design dossier, self-assessment by the manufacturer, a third-party assessment and, review of the design dossier by a “Notified Body.” This third-party assessment generally consists of an audit of the manufacturer’s quality system and manufacturing site, as well as review of the technical documentation used to support application of the CE mark to one’s product and possibly specific testing of the manufacturer’s product. An assessment by a Notified Body of one country within the European Union is required in order for a manufacturer to commercially distribute the product throughout the European Union. We obtained CE marking approval for sale of the Diamondback 360° in May 2005.

Environmental Regulation

Our operations are subject to regulatory requirements relating to the environment, waste management and health and safety matters, including measures relating to the release, use, storage, treatment, transportation, discharge, disposal and remediation of hazardous substances. We are currently classified and licensed as a Very Small Quantity Hazardous Waste Generator within Ramsey County, Minnesota. There are no regulated wastes requiring licensing in our Texas facility.

Employees

As of June 30, 2011, we had 286 employees, including 66 employees in manufacturing, 166 employees in sales, six employees in marketing, seven employees in clinical, 23 employees in general and administrative, and 18 employees in research and development, all of which are full-time employees. None of our employees are represented by a labor union or parties to a collective bargaining agreement, and we believe that our employee relations are good.

Risks Relating to Our Business and Operations

We have a history of net losses and may continue to incur losses.

We are not profitable and have incurred net losses in each fiscal year since our formation in 1989. In particular, we had net losses of $11.1 million in fiscal 2011, $23.9 million in fiscal 2010, and $31.9 million in fiscal 2009. As of June 30, 2011, we had an accumulated deficit of approximately $162.4 million. We commenced commercial sales of the Diamondback 360° in September 2007, and our short commercialization experience makes it difficult for us to predict future performance. We also expect to incur significant additional expenses for sales and marketing and manufacturing as we continue to commercialize the PAD Systems and additional expenses as we seek to develop and commercialize future versions of the PAD Systems and other products. Additionally, we expect that our general and administrative expenses will increase as our business grows. As a result, our operating losses could continue.

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We may be unable to sustain our revenue growth.

Our revenue has grown in each of the three complete fiscal years since we commenced commercial sales of the Diamondback 360° in September 2007. Our ability to continue to increase our revenues in future periods will depend on our ability to increase sales of the PAD Systems and new and improved products we introduce, including growing our customer base and reorders of the PAD Systems from those customers. We may not be able to generate, sustain or increase revenues on a quarterly or annual basis. If we cannot achieve or sustain revenue growth for an extended period, our financial results will be adversely affected and our stock price may decline.

Economic conditions may adversely affect our business.

Adverse worldwide economic conditions may have adverse implications on our business. For example, our customers’ ability to borrow money from their existing lenders or to obtain credit from other sources to fund operations may be impaired resulting in a decrease in sales. Although we review our customers’ financial condition and ability to pay on an ongoing basis and we maintain allowances for doubtful accounts for estimated losses resulting from the inability of our customers to make required payments, we cannot guarantee that we will continue to experience the same loss rates that we have in the past. A significant change in the liquidity or financial condition of our customers could cause unfavorable trends in our receivable collections and additional allowances may be required, which could adversely affect our operating results. Adverse worldwide economic conditions may also adversely impact our suppliers’ ability to provide us with materials and components, which could adversely affect our business and operating results. In addition, uncertainty about current global economic conditions could increase the volatility of our stock price.

We have a limited history selling the PAD Systems, which are currently our primary products, and our inability to market these products successfully would have a material adverse effect on our business and financial condition.

Although we also sell a variety of ancillary products, the PAD Systems are our primary products and we are largely dependent on them. We have limited experience in the commercial manufacturing and marketing of these products. Our ability to generate revenue will depend upon our ability to further successfully commercialize the PAD Systems and to develop, manufacture and receive required regulatory clearances and approvals and patient reimbursement for treatment with future versions of the PAD Systems. As we continue to commercialize the PAD Systems, we may need to expand our sales force to reach our target market. Developing a sales force is expensive and time consuming and could delay or limit the success of any product launch. Thus, we may not be able to expand our sales and marketing capabilities on a timely basis or at all. If we are unable to adequately increase these capabilities, we will need to contract with third parties to market and sell the PAD Systems and any other products that we may develop. To the extent that we enter into arrangements with third parties to perform sales, marketing and distribution services on our behalf, our product revenues could be lower than if we marketed and sold our products on a direct basis. Furthermore, any revenues resulting from co-promotion or other marketing and sales arrangements with other companies will depend on the skills and efforts of others, and we do not know whether these efforts will be successful. If we fail to successfully develop, commercialize and market the PAD Systems or any future versions of these products that we develop, our business will be materially adversely affected.

The PAD Systems and future products may never achieve broad market acceptance.

The PAD Systems and future products we may develop may never gain broad market acceptance among physicians, patients and the medical community. The degree of market acceptance of any of our products will depend on a number of factors, including:

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Failure of the PAD Systems to significantly penetrate current or new markets would negatively impact our business, financial condition and results of operations.

If longer-term or more extensive clinical trials performed by us or others indicate that procedures using the PAD Systems or any future products are not safe, effective and long lasting, physicians may choose not to use our products. Furthermore, unsatisfactory patient outcomes or injuries could cause negative publicity for our products. Physicians may be slow to adopt our products if they perceive liability risks arising from the use of these products. It is also possible that as our products become more widely used, latent defects could be identified, creating negative publicity and liability problems for us, thereby adversely affecting demand for our products. If the PAD Systems and our future products do not achieve an adequate level of acceptance by physicians, patients and the medical community, our overall business and profitability would be harmed.

Our future growth depends on physician adoption of the PAD Systems, which requires physicians to change their screening and referral practices.

We believe that we must educate physicians to change their screening and referral practices. For example, although there is a significant correlation between PAD and coronary artery disease, many physicians do not routinely screen for PAD while screening for coronary artery disease. We target our sales efforts to interventional cardiologists, vascular surgeons and interventional radiologists because they are often the primary care physicians diagnosing and treating both coronary artery disease and PAD. However, the initial point of contact for many patients may be general practitioners, podiatrists, nephrologists and endocrinologists, each of whom commonly treats patients experiencing complications resulting from PAD. If referring physicians are not educated about PAD in general and the existence of the PAD Systems in particular, they may not refer patients to interventional cardiologists, vascular surgeons or interventional radiologists for the procedure using the PAD Systems, and those patients may instead be surgically treated or treated with an alternative interventional procedure. If we are not successful in educating physicians about screening for PAD or referral opportunities, our ability to increase our revenue may be impaired.

Our customers may not be able to achieve adequate reimbursement for using the PAD Systems, which could affect the acceptance of our products and cause our business to suffer.

The availability of insurance coverage and reimbursement for newly approved medical devices and procedures is uncertain. The commercial success of our products is substantially dependent on whether third-party insurance coverage and reimbursement for the use of such products and related services are available. We expect the PAD Systems to generally be purchased by hospitals and other providers who will then seek reimbursement from various public and private third-party payors, such as Medicare, Medicaid and private insurers, for the services provided to patients. We can give no assurance that these third-party payors will provide adequate reimbursement for use of the PAD Systems to permit hospitals and doctors to consider the products cost-effective for patients requiring PAD treatment, or that current reimbursement levels for the PAD Systems will continue. In addition, the overall amount of reimbursement available for PAD treatment could decrease in the future. Failure by hospitals and other users of our products to obtain sufficient reimbursement could cause our business to suffer.

Medicare, Medicaid, health maintenance organizations and other third-party payors are increasingly attempting to contain healthcare costs by limiting both coverage and the level of reimbursement, and, as a result, they may not cover or provide adequate payment for use of the PAD Systems. In order to position the PAD Systems for acceptance by third-party payors, we may have to agree to lower prices than we might otherwise charge.

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Governmental and private sector payors have instituted initiatives to limit the growth of healthcare costs using, for example, price regulation or controls and competitive pricing programs. Some third-party payors also require demonstrated superiority, on the basis of randomized clinical trials, or pre-approval of coverage, for new or innovative devices or procedures before they will reimburse healthcare providers who use such devices or procedures. It is uncertain whether the PAD Systems or any future products we may develop will be viewed as sufficiently cost-effective to warrant adequate coverage and reimbursement levels.

If third-party coverage and reimbursement for the PAD Systems is limited or not available, the acceptance of the PAD Systems and, consequently, our business will be substantially harmed.

Healthcare reform legislation could adversely affect our operating results and financial condition.

There have been and continue to be proposals by the federal government, state governments, regulators and third-party payors to control healthcare costs and, more generally, to reform the U.S. healthcare system. Certain of these proposals could limit the prices we are able to charge for our products or the amounts of reimbursement available for our products and could limit the acceptance and availability of our products. The adoption of some or all of these proposals, including the recent federal legislation, could adversely affect our revenue and financial condition.

On March 23, 2010, President Obama signed the Patient Protection and Affordable Care Act, or the Patient Act. The impact on the healthcare industry of the Patient Act is extensive and includes, among other things, having the federal government assume a larger role in the healthcare system, expanding healthcare coverage of United States citizens and mandating basic healthcare benefits. Elements of this legislation, such as comparative effectiveness research, an independent payment advisory board, payment system reforms, including shared savings programs and other provisions, could meaningfully change the way healthcare is developed and delivered, and may materially impact numerous aspects of our business. These changes may impact reimbursement for health care services, including reimbursement to hospitals and physicians. States may also enact further legislation that impacts Medicaid payments to hospitals and physicians. In addition, the Centers for Medicare & Medicaid Services, the Federal agency responsible for administering the Medicare program, may establish new payment levels for hospitals and physicians in line with the new legislation, which could increase or decrease payment to such entities. The healthcare reform legislation and any future legislative and regulatory initiatives could adversely affect demand for our products and have a material adverse impact on our operating results. Any healthcare reforms enacted in the future may, like the Patient Act, be phased in over a number of years but, if enacted, could reduce our revenues, increase our costs, or require us to revise the ways in which we conduct business or put us at risk for loss of business. Our results of operations, financial position and cash flows could be materially adversely affected by changes under the Patient Act and changes under any federal or state legislation adopted in the future.

The Patient Act also imposes significant new taxes on medical device makers. These taxes will result in a significant increase in the tax burden on our industry, which could have a material, negative impact on our results of operations, financial position and cash flows. As rules and regulations are developed under the new law, there may be exemptions created for certain types or classes of products. We may find, however, that there are no exemptions applicable to our products. This tax will impact our cost of doing business and may ultimately lower our profit margins. Additionally, the increased cost of business caused by this tax may hinder our ability to spend money on research and development of our products. We may be required to increase the prices of our devices to offset the additional cost of the tax. Medicaid and health insurance providers may place a cap on the reimbursement for purchases of our devices that will not allow us to offset the cost of the tax. We may ultimately lose customers who are unwilling or unable to pay the increased costs, which could adversely affect our business and operating results.

We have limited data and experience regarding the safety and efficacy of the PAD Systems. Any long-term data that is generated may not be positive or consistent with our limited short-term data, which would affect market acceptance of these products.

Our success depends on the acceptance of the PAD Systems by the medical community as safe and effective. Because our technology is relatively new in the treatment of PAD, we have performed clinical trials

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only with limited patient populations. The long-term effects of using the PAD Systems in a large number of patients are not known and the results of short-term clinical use of the PAD Systems do not necessarily predict long-term clinical benefit or reveal long-term adverse effects. If the results obtained from any future clinical trials or clinical or commercial experience indicate that the PAD Systems are not as safe or effective as other treatment options or as current short-term data would suggest, adoption of these products may suffer and our business would be harmed.

Even if we believe that the data collected from clinical trials or clinical experience indicate positive results, each physician’s actual experience with our device will vary. Clinical trials conducted with the PAD Systems have involved procedures performed by physicians who are very technically proficient. Consequently, both short and long-term results reported in these studies may be significantly more favorable than typical results achieved by physicians, which could negatively impact market acceptance of the PAD Systems.

We face significant competition and may be unable to sell the PAD Systems at profitable levels.

We compete against very large and well-known stent and balloon angioplasty device manufacturers, including Abbott Laboratories, Boston Scientific, Cook Medical, Johnson & Johnson and Medtronic. We may have difficulty competing effectively with these competitors because of their well-established positions in the marketplace, significant financial and human capital resources, established reputations and worldwide distribution channels. We also compete against manufacturers of atherectomy catheters including, among others, Covidien, Spectranetics, Boston Scientific and Pathway Medical Technologies, as well as other manufacturers that may enter the market due to the increasing demand for treatment of vascular disease. Several other companies provide products used by surgeons in peripheral bypass procedures. Other competitors include pharmaceutical companies that manufacture drugs for the treatment of mild to moderate PAD and companies that provide products used by surgeons in peripheral bypass procedures.

Our competitors may:

We have encountered and expect to continue to encounter potential customers who, due to existing relationships with our competitors, are committed to or prefer the products offered by these competitors. If we are unable to compete successfully, our revenue will suffer. Increased competition might lead to price reductions and other concessions that might adversely affect our operating results. Competitive pressures may decrease the demand for our products and could adversely affect our financial results.

Our ability to compete depends on our ability to innovate successfully. If our competitors demonstrate the increased safety or efficacy of their products as compared to ours, our revenue may decline.

The market for medical devices is highly competitive, dynamic and marked by rapid and substantial technological development and product innovations. Our ability to compete depends on our ability to innovate successfully, and there are few barriers that would prevent new entrants or existing competitors from developing products that compete directly with our products. Demand for the PAD Systems could be diminished by equivalent or superior products and technologies offered by competitors. Our competitors may produce more advanced products than ours or demonstrate superior safety and efficacy of their products. If we are unable to innovate successfully, the PAD Systems could become obsolete and our revenue would decline as our customers purchase competitor products.

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We have limited commercial manufacturing experience and could experience difficulty in producing the PAD Systems or will need to depend on third parties to manufacture the products.

We have limited experience in commercially manufacturing the PAD Systems and have no experience manufacturing these products in the volume that we anticipate will be required if we achieve planned levels of commercial sales. As a result, we may not be able to develop and implement efficient, low-cost manufacturing capabilities and processes that will enable us to manufacture the PAD Systems or future products in significant volumes, while meeting the legal, regulatory, quality, price, durability, engineering, design and production standards required to market our products successfully. If we fail to develop and implement these manufacturing capabilities and processes, we may be unable to profitably commercialize the PAD Systems and any future products we may develop because the per unit cost of our products is highly dependent upon production volumes and the level of automation in our manufacturing processes. There are technical challenges to increasing manufacturing capacity, including equipment design and automation capabilities, material procurement, problems with production yields and quality control and assurance. Increasing our manufacturing capacity may require that we invest substantial additional funds and hire and retain additional management and technical personnel who have the necessary manufacturing experience. We may not successfully complete any required increase in manufacturing capacity in a timely manner or at all. If we are unable to manufacture a sufficient supply of our products, maintain control over expenses or otherwise adapt to anticipated growth, or if we underestimate growth, we may not have the capability to satisfy market demand and our business will suffer.

The forecasts of demand we use to determine order quantities and lead times for components purchased from outside suppliers may be incorrect. Failure to obtain required components or subassemblies when needed and at a reasonable cost would adversely affect our business.

In addition, we may in the future need to depend upon third parties to manufacture the PAD Systems and future products. We also cannot assure you that any third-party contract manufacturers will have the ability to produce the quantities of our products needed for development or commercial sales or will be willing to do so at prices that allow the products to compete successfully in the market. Additionally, we can give no assurance that even if we do contract with third-party manufacturers for production that these manufacturers will not experience manufacturing difficulties or experience quality or regulatory issues. Any difficulties in locating and hiring third-party manufacturers, or in the ability of third-party manufacturers to supply quantities of our products at the times and in the quantities we need, could have a material adverse effect on our business.

We depend upon third-party suppliers, including single source suppliers to us and our customers, making us vulnerable to supply problems and price fluctuations.

We rely on third-party suppliers to provide us with certain components of our products and to provide key components or supplies to our customers for use with our products. We rely on single source suppliers for the components of the PAD Systems. We purchase components from these suppliers on a purchase order basis and carry only limited levels of inventory for these components. If we underestimate our requirements, we may not have an adequate supply, which could interrupt manufacturing of our products and result in delays in shipments and loss of revenue. Conversely, an overestimation of our requirements will reduce our cash available for operations and may result in excess or obsolete materials.

We depend on our suppliers to provide us and our customers with materials in a timely manner that meet our and their quality, quantity and cost requirements. These suppliers may encounter problems during manufacturing for a variety of reasons, any of which could delay or impede their ability to meet our demand and our customers’ demand. Our reliance on these outside suppliers also subjects us to other risks that could harm our business, including:

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Any supply interruption from our suppliers or failure to obtain additional suppliers for any of the components used in our products would limit our ability to manufacture our products and could have a material adverse effect on our business, financial condition and results of operations. If we lost one of these suppliers and were unable to obtain an alternate source on a timely basis or on terms acceptable to us, our production schedules could be delayed, our margins could be negatively impacted, and we could fail to meet our customers’ demand. Our customers rely upon our ability to meet committed delivery dates and any disruption in the supply of key components would adversely affect our ability to meet these dates and could result in legal action by our customers, cause us to lose customers or harm our ability to attract new customers, any of which could decrease our revenue and negatively impact our growth. In addition, to the extent that our suppliers use technology or manufacturing processes that are proprietary, we may be unable to obtain comparable materials or components from alternative sources.

We may be faced with a supplier’s decision to discontinue manufacturing a component, which may force us or our customers to make last time purchases, qualify a substitute part, or make a design change which may divert engineering time away from the development of new products.

Consolidation in the healthcare industry could lead to demands for price concessions or the exclusion of some suppliers from our market segment, which could have an adverse effect on our business, financial condition or results of operations.

The cost of healthcare has risen significantly over the past decade and numerous initiatives and reforms by legislators, regulators and third-party payors to curb these costs have resulted in a consolidation trend in the healthcare industry. This in turn has resulted in greater pricing pressures and the exclusion of certain suppliers from important market segments as group purchasing organizations, independent delivery networks and large single accounts continue to consolidate purchasing decisions for some of our hospital customers. We expect that market demand, government regulation, third-party reimbursement policies, government contracting requirements, and societal pressures will continue to change the worldwide healthcare industry, resulting in further business consolidations and alliances among our customers and competitors, which may reduce competition, exert downward pressure on the prices of our products and adversely impact our business, financial condition or results of operations.

We may need to increase the size of our organization and we may experience difficulties managing growth. If we are unable to manage the anticipated growth of our business, our future revenue and operating results may be adversely affected.

The growth we may experience in the future may provide challenges to our organization, requiring us to rapidly expand our sales and marketing personnel and manufacturing operations. Our sales and marketing force

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has increased from six full-time employees on January 1, 2007 to 172 full-time employees on June 30, 2011, and we expect to continue to grow our sales and marketing force in the future. We also expect to significantly expand our manufacturing operations to meet anticipated growth in demand for our products. Rapid expansion in personnel may result in less experienced people producing and selling our product, which could result in unanticipated costs and disruptions to our operations. If we cannot scale and manage our business appropriately, our anticipated growth may be impaired and our financial results will suffer.

We may require additional financing, and our failure to obtain additional financing when needed could force us to delay, reduce or eliminate our product development programs or commercialization efforts.

We may be dependent on additional financing to execute our business plan. We may require additional capital in order to continue to conduct the research and development and obtain regulatory clearances and approvals necessary to bring any future products to market and to establish effective marketing and sales capabilities for existing and future products. Our operating plan may change, and we may need additional funds sooner than anticipated to meet our operational needs and capital requirements for product development, clinical trials and commercialization. Additional funds may not be available when we need them on terms that are acceptable to us, or at all. If adequate funds are not available on a timely basis, we may terminate or delay the development of one or more of our products, or delay establishment of sales and marketing capabilities or other activities necessary to commercialize our products.

Our future capital requirements will depend on many factors, including:

Disruptions in the global financial markets, including the bankruptcy, failure, collapse or sale of various financial institutions and an unprecedented level of intervention from the United States and other governments and the related liquidity crisis, considerably disrupted the credit and capital markets at the end of 2008 and markets have not fully recovered since then. In the event we need or desire additional financing, we may be unable to obtain it by borrowing money in the credit markets or raising money in the capital markets.

We face a risk of non-compliance with the financial covenants in our loan and security agreements with Silicon Valley Bank and Partners for Growth.

We are party to loan and security agreements with Silicon Valley Bank and Partners for Growth. These agreements require us to maintain, among other things, a monthly specified liquidity ratio and a monthly adjusted earnings before interest, taxes, depreciation and amortization, or EBITDA, level. The agreements contain customary events of default, including, among others, the failure to comply with certain covenants or other agreements. Upon the occurrence and during the continuation of an event of default, amounts due under the agreements may be accelerated by Silicon Valley Bank or Partners for Growth. We were not in compliance with some of the financial covenants contained in our prior loan agreement with Silicon Valley Bank during certain months in the year ended June 30, 2010, which Silicon Valley Bank waived and these covenants were subsequently changed in our amended and restated loan and security agreement with Silicon Valley Bank. If we are unable to meet the financial or other covenants under the current loan and security agreements or negotiate future waivers or amendments of such covenants, events of default could occur under the agreements. Upon the occurrence and during the continuance of an event of default under the agreements, Silicon Valley Bank and Partners for Growth have available a range of remedies customary in these circumstances, including declaring all

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outstanding debt, together with accrued and unpaid interest thereon, to be due and payable, foreclosing on the assets securing the agreements and/or ceasing to provide additional loans, which could have a material adverse effect on us.

The restrictive covenants in our loan and security agreements could limit our ability to conduct our business and respond to changing economic and business conditions and may place us at a competitive disadvantage relative to other companies that are subject to fewer restrictions.

Our loan and security agreements with Silicon Valley Bank and Partners for Growth limit our ability to, among other things:

The restrictive covenants under these agreements could limit our ability to obtain future financing, withstand a future downturn in our business or the economy in general or otherwise conduct necessary corporate activities. The financial and restrictive covenants contained in the agreements could also adversely affect our ability to respond to changing economic and business conditions and place us at a competitive disadvantage relative to other companies that may be subject to fewer restrictions. Transactions that we may view as important opportunities, such as acquisitions, may be subject to the consent of Silicon Valley Bank and Partners for Growth, which consents may be withheld or granted subject to conditions specified at the time that may affect the attractiveness or viability of the transaction.

We do not intend to market the PAD Systems internationally in the near future, which will limit our potential revenue from these products.

While we plan to continue to evaluate the financial viability of marketing the PAD Systems internationally, we currently do not intend to market the PAD Systems internationally in the near future in order to focus our resources and efforts on the U.S. market, as international efforts would require substantial additional sales and marketing, regulatory and personnel expenses. Our decision to market these products only in the United States will limit our ability to reach all of our potential markets and will limit our potential sources of revenue. In addition, our competitors will have an opportunity to further penetrate and achieve market share abroad until such time, if ever, that we market the PAD Systems or other products internationally.

We are dependent on our senior management team and highly skilled personnel, and our business could be harmed if we are unable to attract and retain personnel necessary for our success.

We are highly dependent on our senior management, especially David L. Martin, our President and Chief Executive Officer. Our success will depend on our ability to retain senior management and to attract and retain qualified personnel in the future, including scientists, clinicians, engineers and other highly skilled personnel and to integrate current and additional personnel in all departments. Competition for senior management personnel, as well as scientists, clinical and regulatory specialists, engineers and sales personnel, is intense and we may not be able to retain our personnel. The loss of members of our senior management, scientists, clinical and regulatory specialists, engineers and sales personnel could prevent us from achieving our objectives of continuing to grow the company. The loss of a member of our senior management or professional staff would require the remaining senior executive officers to divert immediate and substantial attention to seeking a replacement. In particular, we expect to substantially increase the size of our sales force, which will require management’s attention. We do not carry key person life insurance on any of our employees.

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Risks Related to Government Regulation

Our ability to market the PAD Systems in the United States is limited to use as a therapy in patients with PAD, and if we want to expand our marketing claims, we will need to file for additional FDA clearances or approvals and conduct further clinical trials, which would be expensive and time-consuming and may not be successful.

The PAD Systems received FDA 510(k) clearances in the United States for use as a therapy in patients with PAD. This general clearance restricts our ability to market or advertise the PAD Systems beyond this use and could affect our growth. While off-label uses of medical devices are common and the FDA does not regulate physicians’ choice of treatments, the FDA does restrict a manufacturer’s communications regarding such off-label use. We are not permitted to promote or advertise the PAD Systems for off-label uses. In addition, we cannot make comparative claims regarding the use of the PAD Systems against any alternative treatments without conducting head-to-head comparative clinical trials, which would be expensive and time consuming. If our promotional activities fail to comply with the FDA’s regulations or guidelines, we may be subject to FDA warnings or enforcement action.

If we determine to market the PAD Systems in the United States for other uses, for instance, use in the coronary arteries, we would need to conduct further clinical trials and obtain premarket approval from the FDA. In 2008, we completed the ORBIT I trial, a 50-patient study in India which investigated the safety of the Diamondback 360° in treating calcified coronary artery lesions, and results successfully met both safety and efficacy endpoints. In May 2011, we received approval from the FDA to complete enrollment of 429 patients in our ORBIT II clinical trial for a coronary application for the Diamondback 360°, which followed the FDA’s review of data from the first 50 cases in the ORBIT II trial. Clinical trials are complex, expensive, time consuming, uncertain and subject to substantial and unanticipated delays. Clinical trials generally involve a substantial number of patients in one or more multi-year studies. We may encounter problems with our clinical trials, and any of those problems could cause us or the FDA to suspend those trials, or delay the analysis of the data derived from them.

A number of events or factors, including any of the following, could delay the completion of our clinical trials in the future and negatively impact our ability to obtain FDA clearance or approval for, and to introduce, a particular future product:

Our clinical trials may not begin as planned, may need to be redesigned, and may not be completed on schedule, if at all. Delays in our clinical trials may result in increased development costs for our future product candidates, which could limit our ability to obtain additional financing. In addition, if one or more of our clinical trials is delayed, competitors may be able to bring products to market before we do, and the commercial viability of our future product candidates could be significantly reduced.

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We may become subject to regulatory actions if we are found to have promoted the PAD Systems for unapproved uses.

If the FDA determines that our promotional materials, training or other activities constitute promotion of our products for unapproved uses, it could request that we cease use of or modify our training or promotional materials or subject us to regulatory enforcement actions, including the issuance of an untitled or warning letter, injunction, seizure, civil fine and criminal penalties. It is also possible that other federal, state or foreign enforcement authorities might take action if they consider promotional, training or other materials to constitute promotion of our products for an unapproved or uncleared use, which could result in significant fines or penalties under other statutory authorities, such as laws prohibiting false claims for reimbursement.

The PAD Systems may in the future be subject to product recalls that could harm our reputation.

The FDA and similar governmental authorities in other countries have the authority to require the recall of commercialized products in the event of material regulatory deficiencies or defects in design or manufacture. A government mandated or voluntary recall by us could occur as a result of component failures, manufacturing errors or design or labeling defects. During the time of commercialization, we have had two minor instances of recall, involving a single lot of Diamondback 360° devices (eight units), and two boxes of ViperWires (ten wires), related to “Use By” date labeling issues. In addition, a third recall, initiated in 2009 and completed in 2010, involved the ViperSheath, which is owned and manufactured by Thomas Medical Products. As the distributor for the ViperSheath, we were required to recall all unused units from our customers and return them to Thomas Medical Products. Any additional recalls of our products or products that we distribute would divert managerial and financial resources, harm our reputation with customers and have an adverse effect on our financial condition and results of operations.

If we or our suppliers fail to comply with ongoing regulatory requirements, or if we experience unanticipated problems, our products could be subject to restrictions or withdrawal from the market.

The PAD Systems and related manufacturing processes, clinical data, adverse events, recalls or corrections and promotional activities, are subject to extensive regulation by the FDA and other regulatory bodies. In particular, we are required to comply with the FDA’s Quality System Regulation, or QSR, and other regulations, which cover the methods and documentation of the design, testing, production, control, quality assurance, labeling, packaging, storage and shipping of any product for which we obtain marketing clearance or approval. We are also responsible for the quality of components received by our suppliers. Failure to comply with the QSR requirements or other statutes and regulations administered by the FDA and other regulatory bodies, or failure to adequately respond to any observations, could result in, among other things:

If any of these actions were to occur, it would harm our reputation and cause our product sales to suffer.

Furthermore, any modification to a device that has received FDA clearance or approval that could significantly affect its safety or efficacy, or that would constitute a major change in its intended use, design or

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manufacture, requires a new clearance or approval from the FDA. If the FDA disagrees with any determination by us that new clearance or approval is not required, we may be required to cease marketing or to recall the modified product until we obtain clearance or approval. In addition, we could be subject to significant regulatory fines or penalties.

Regulatory clearance or approval of a product may also require costly post-marketing testing or surveillance to monitor the safety or efficacy of the product. Later discovery of previously unknown problems with our products, including unanticipated adverse events or adverse events of unanticipated severity or frequency, manufacturing problems, or failure to comply with regulatory requirements such as the QSR, may result in restrictions on such products or manufacturing processes, withdrawal of the products from the market, voluntary or mandatory recalls, fines, suspension of regulatory approvals, product seizures, injunctions or the imposition of civil or criminal penalties.

The use, misuse or off-label use of the PAD Systems may increase the risk of injury, which could result in product liability claims and damage to our business.

The use, misuse or off-label use of the PAD Systems may result in injuries that lead to product liability suits, which could be costly to our business. The PAD Systems are not FDA-cleared or approved for treatment of the carotid arteries, the coronary arteries, within bypass grafts or stents, of thrombus or where the lesion cannot be crossed with a guidewire or a significant dissection is present at the lesion site. We cannot prevent a physician from using the PAD Systems for off-label applications. The off-label use of the PAD Systems may be more likely to result in complications that have serious consequences, including, in certain circumstances, death.

We may face risks related to product liability claims, which could exceed the limits of available insurance coverage.

If the PAD Systems are defectively designed, manufactured or labeled, contain defective components or are misused, we may become subject to costly litigation by our customers or their patients. The medical device industry is subject to substantial litigation, and we face an inherent risk of exposure to product liability claims in the event that the use of our products results or is alleged to have resulted in adverse effects to a patient. In most jurisdictions, producers of medical products are strictly liable for personal injuries caused by medical devices. We may be subject in the future to claims for personal injuries arising out of the use of our products. Product liability claims could divert management’s attention from our core business, be expensive to defend and result in sizable damage awards against us. A product liability claim against us, even if ultimately unsuccessful, could have a material adverse effect on our financial condition, results of operations, and reputation. While we have product liability insurance coverage for our products and intend to maintain such insurance coverage in the future, there can be no assurance that we will be adequately protected from the claims that will be brought against us.

Compliance with environmental laws and regulations could be expensive. Failure to comply with environmental laws and regulations could subject us to significant liability.

Our operations are subject to regulatory requirements relating to the environment, waste management and health and safety matters, including measures relating to the release, use, storage, treatment, transportation, discharge, disposal and remediation of hazardous substances. Although we are currently classified as a Very Small Quantity Hazardous Waste Generator within Ramsey County, Minnesota, we cannot ensure that we will maintain our licensed status as such, nor can we ensure that we will not incur material costs or liability in connection with our operations, or that our past or future operations will not result in claims or injury by employees or the public. Environmental laws and regulations could also become more stringent over time, imposing greater compliance costs and increasing risks and penalties associated with violations.

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We and our distributors must comply with various federal and state anti-kickback, self-referral, false claims and similar laws, any breach of which could cause a material adverse effect on our business, financial condition and results of operations.

Our relationships with physicians, hospitals and the marketers of our products are subject to scrutiny under various federal anti-kickback, self-referral, false claims and similar laws, often referred to collectively as healthcare fraud and abuse laws.

Healthcare fraud and abuse laws are complex, and even minor, inadvertent violations can give rise to claims that the relevant law has been violated. If our operations are found to be in violation of these laws, we, as well as our employees, may be subject to penalties, including monetary fines, civil and criminal penalties, exclusion from federal and state healthcare programs, including Medicare, Medicaid, Veterans Administration health programs, workers’ compensation programs and TRICARE (the healthcare system administered by or on behalf of the U.S. Department of Defense for uniformed services beneficiaries, including active duty and their dependents, retirees and their dependents), and forfeiture of amounts collected in violation of such prohibitions. Individual employees may need to defend such suits on behalf of us or themselves, which could lead to significant disruption in our present and future operations. Certain states in which we intend to market our products have similar fraud and abuse laws, imposing substantial penalties for violations. Any government investigation or a finding of a violation of these laws would likely have a material adverse effect on our business, financial condition and results of operations.

Anti-kickback laws and regulations prohibit any knowing and willful offer, payment, solicitation or receipt of any form of remuneration in return for the referral of an individual or the ordering or recommending of the use of a product or service for which payment may be made by Medicare, Medicaid or other government-sponsored healthcare programs. In addition, the cost of non-compliance with these laws could be substantial, since we could be subject to monetary fines and civil or criminal penalties, and we could also be excluded from federally funded healthcare programs for non-compliance.

We have entered into consulting agreements with physicians, including some who may make referrals to us or order our products. One of these physicians was one of 20 principal investigators in our OASIS clinical trial at the same time he was acting as a paid consultant for us. In addition, prior to our merger with Replidyne, some of these physicians purchased our stock in arm’s-length transactions on terms identical to those offered to non-physicians or received stock options from us as consideration for consulting services performed by them. We believe that these consulting agreements and equity investments by physicians are common practice in our industry, and while these transactions were structured with the intention of complying with all applicable laws, including the federal ban on physician self-referrals, commonly known as the “Stark Law,” state anti-referral laws and other applicable anti-kickback laws, it is possible that regulatory or enforcement agencies or courts may in the future view these transactions as prohibited arrangements that must be restructured or for which we would be subject to other significant civil or criminal penalties, or prohibit us from accepting referrals from these physicians. Because our strategy relies on the involvement of physicians who consult with us on the design of our product, we could be materially impacted if regulatory or enforcement agencies or courts interpret our financial relationships with our physician advisors who refer or order our products to be in violation of applicable laws and determine that we would be unable to achieve compliance with such applicable laws. This could harm our reputation and the reputations of our clinical advisors.

The scope and enforcement of all of these laws is uncertain and subject to rapid change. There can be no assurance that federal or state regulatory or enforcement authorities will not investigate or challenge our current or future activities under these laws. Any investigation or challenge could have a material adverse effect on our business, financial condition and results of operations. Any state or federal regulatory or enforcement review of us, regardless of the outcome, would be costly and time consuming. Additionally, we cannot predict the impact of any changes in these laws, whether these changes are retroactive or will have effect on a going-forward basis only.

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We incur significant costs as a result of operating as a public company, and our management is required to devote substantial time to compliance initiatives.

As a public company, we incur significant legal, accounting and other expenses. In addition, the Sarbanes-Oxley Act, as well as rules subsequently implemented by the SEC and the Nasdaq Global Market, have imposed various requirements on public companies, including requiring the establishment and maintenance of effective disclosure and financial controls and changes in corporate governance practices. Our management and other personnel devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations have increased our legal and compliance costs and made some activities more time consuming and costly. We cannot ensure that our corporate compliance program is in compliance with or will continue to comply with all potentially applicable regulations.

The Sarbanes-Oxley Act requires, among other things, that we maintain effective internal controls for financial reporting and disclosure controls and procedures. In particular, we must perform system and process evaluation and testing of our internal controls over financial reporting to allow management and our independent registered public accounting firm to report on the effectiveness of our internal controls over financial reporting. Our testing, or the subsequent testing by our independent registered public accounting firm, may reveal deficiencies in our internal controls over financial reporting that are deemed to be material weaknesses. Moreover, if we are not able to comply with these requirements in a timely manner, or if we or our independent registered public accounting firm identifies deficiencies in our internal controls over financial reporting that are deemed to be material weaknesses, the market price of our stock could decline and we could be subject to sanctions or investigations by Nasdaq, the SEC or other regulatory authorities, which would require additional financial and management resources.

These obligations divert management’s time and attention away from our business. Our management may not be able to effectively and timely implement controls and procedures that adequately respond to the increased regulatory compliance and reporting requirements that are applicable. If we fail to staff our accounting and finance function adequately or maintain internal controls adequate to meet the demands that are placed upon us a public company, including the requirements of the Sarbanes-Oxley Act, we may be unable to report our financial results accurately or in a timely manner, and our business and stock price may suffer. The costs of being a public company, as well as diversion of management’s time and attention, may have a material adverse effect on our business, financial condition and results of operations.

Additionally, these laws and regulations could make it more difficult or more costly for us to obtain certain types of insurance, including director and officer liability insurance, and we may be forced to accept reduced policy limits and coverage or incur substantially higher costs to obtain the same or similar coverage. The impact of these events could also make it more difficult for us to attract and retain qualified persons to serve on our board of directors, board committees or as executive officers.

Risks Relating to Our Intellectual Property

Our inability to adequately protect our intellectual property could allow our competitors and others to produce products based on our technology, which could substantially impair our ability to compete.

Our success and ability to compete depends, in part, upon our ability to maintain the proprietary nature of our technologies. We rely on a combination of patents, copyrights and trademarks, as well as trade secrets and nondisclosure agreements, to protect our intellectual property. As of July 31, 2011, we had a portfolio of 21 issued U.S. patents, 31 pending U.S. patent applications, 63 issued or granted non-U.S. patents, and 98 pending non-U.S. patent applications covering aspects of our core technology, which expire between 2011 and 2027. However, our issued patents and related intellectual property may not be adequate to protect us or permit us to gain or maintain a competitive advantage. The issuance of a patent is not conclusive as to its scope, validity or enforceability. The scope, validity or enforceability of our issued patents can be challenged in litigation or proceedings before the U.S. Patent and Trademark Office, or the USPTO. In addition, our pending patent applications include claims to numerous important aspects of our products under development that are not currently protected by any of our issued patents. We cannot assure you that any of our pending patent applications will result in the issuance of patents to us. The USPTO may deny or require significant narrowing of

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claims in our pending patent applications. Even if any patents are issued as a result of pending patent applications, they may not provide us with significant commercial protection or be issued in a form that is advantageous to us. Proceedings before the USPTO could result in adverse decisions as to the priority of our inventions and the narrowing or invalidation of claims in issued patents. Further, if any patents we obtain or license are deemed invalid and unenforceable, or have their scope narrowed, it could impact our ability to commercialize or license our technology.

Changes in either the patent laws or in interpretations of patent laws in the United States and other countries may diminish the value of our intellectual property. For instance, the U.S. Supreme Court has recently modified some tests used by the USPTO in granting patents during the past 20 years, which may decrease the likelihood that we will be able to obtain patents and increase the likelihood of challenge of any patents we obtain or license. In addition, the U.S. Congress is now considering patent reform legislation that could transition the U.S. to a “first to file” system and alter the processes for challenging issued patents. These reforms could increase the uncertainties surrounding the prosecution of our patent applications and the enforcement of our issued patents. The laws of some foreign countries may not protect our intellectual property rights to the same extent as the laws of the United States, if at all.

We may, in the future, need to assert claims of infringement against third parties to protect our intellectual property. The outcome of litigation to enforce our intellectual property rights in patents, copyrights, trade secrets or trademarks is highly unpredictable, could result in substantial costs and diversion of resources, and could have a material adverse effect on our financial condition, reputation and results of operations regardless of the final outcome of such litigation. In the event of an adverse judgment, a court could hold that some or all of our asserted intellectual property rights are not infringed, invalid or unenforceable, and could order us to pay third-party attorneys’ fees.

Despite our efforts to safeguard our unpatented and unregistered intellectual property rights, we may not be successful in doing so or the steps taken by us in this regard may not be adequate to detect or deter misappropriation of our technology or to prevent an unauthorized third party from copying or otherwise obtaining and using our products, technology or other information that we regard as proprietary. In addition, we may not have sufficient resources to litigate, enforce or defend our intellectual property rights. Additionally, third parties may be able to design around our patents.

We also rely on trade secrets, technical know-how and continuing innovation to develop and maintain our competitive position. In this regard, we seek to protect our proprietary information and other intellectual property by having a policy that our employees, consultants, contractors, outside scientific collaborators and other advisors execute non-disclosure and assignment of invention agreements on commencement of their employment or engagement. Agreements with our employees also forbid them from bringing the proprietary rights of third parties to us. We also require confidentiality or material transfer agreements from third parties that receive our confidential data or materials. However, trade secrets are difficult to protect. We cannot provide any assurance that employees and third parties will abide by the confidentiality or assignment terms of these agreements, or that we will be effective securing necessary assignments from these third parties. Despite measures taken to protect our intellectual property, unauthorized parties might copy aspects of our products or obtain and use information that we regard as proprietary. Enforcing a claim that a third party illegally obtained and is using any of our trade secrets is expensive and time consuming, and the outcome is unpredictable. In addition, courts outside the United States are sometimes less willing to protect trade secrets. Finally, others may independently discover trade secrets and proprietary information, and this would prevent us from asserting any such trade secret rights against these parties.

Claims of infringement or misappropriation of the intellectual property rights of others could prohibit us from commercializing products, require us to obtain licenses from third parties or require us to develop non-infringing alternatives, and subject us to substantial monetary damages and injunctive relief.

The medical technology industry is characterized by extensive litigation and administrative proceedings over patent and other intellectual property rights. The likelihood that patent infringement or misappropriation claims may be brought against us increases as we achieve more visibility in the marketplace and introduce

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products to market. All issued patents are entitled to a presumption of validity under the laws of the United States. Whether a product infringes a patent involves complex legal and factual issues, the determination of which is often uncertain. Therefore, we cannot be certain that we have not infringed the intellectual property rights of such third parties or others. Our competitors may assert that our products are covered by U.S. or foreign patents held by them. We are aware of numerous patents issued to third parties that relate to the manufacture and use of medical devices for interventional cardiology. The owners of each of these patents could assert that the manufacture, use or sale of our products infringes one or more claims of their patents. Because patent applications may take years to issue, there may be applications now pending of which we are unaware that may later result in issued patents that we infringe. If another party has filed a U.S. patent application on inventions similar to ours, we may have to participate in an interference proceeding declared by the USPTO to determine priority of invention in the United States. The costs of these proceedings can be substantial, and it is possible that such efforts would be unsuccessful if unbeknownst to us, the other party had independently arrived at the same or similar invention prior to our own invention, resulting in a loss of our U.S. patent position with respect to such inventions. There could also be existing patents of which we are unaware that one or more aspects of our technology may inadvertently infringe. In some cases, litigation may be threatened or brought by a patent-holding company or other adverse patent owner who has no relevant product revenues and against whom our patents may provide little or no deterrence.

Any infringement or misappropriation claim could cause us to incur significant costs, place significant strain on our financial resources, divert management’s attention from our business and harm our reputation. Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. In addition, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on our ability to raise the funds necessary to continue our operations. Although patent and intellectual property disputes in the medical device area have often been settled through licensing or similar arrangements, costs associated with such arrangements may be substantial and could include ongoing royalties. If the relevant patents were upheld in litigation as valid and enforceable and we were found to infringe, we could be prohibited from commercializing any infringing products unless we could obtain licenses to use the technology covered by the patent or are able to design around the patent. We may be unable to obtain a license on terms acceptable to us, if at all, and we may not be able to redesign any infringing products to avoid infringement. Further, any redesign may not receive FDA clearance or approval or may not receive such clearance or approval in a timely manner. Any such license could impair operating margins on future product revenue. A court could also order us to pay compensatory damages for such infringement, and potentially treble damages, plus prejudgment interest and third-party attorneys’ fees. These damages could be substantial and could harm our reputation, business, financial condition and operating results. A court also could enter orders that temporarily, preliminarily or permanently enjoin us and our customers from making, using, selling, offering to sell or importing infringing products, or could enter an order mandating that we undertake certain remedial activities. Depending on the nature of the relief ordered by the court, we could become liable for additional damages to third parties. Adverse determinations in a judicial or administrative proceeding or failure to obtain necessary licenses could prevent us from manufacturing and selling our products, which would have a significant adverse impact on our business.

Risks Relating to Ownership of Our Common Stock

Our stock price is volatile and you may not be able to resell your shares.

The market price of our common stock could be subject to significant fluctuations. Market prices for securities of early-stage pharmaceutical, medical device, biotechnology and other life sciences companies have historically been particularly volatile. Our common stock traded as low as $3.75 and as high as $15.72 per share during the twelve-month period ended June 30, 2011. In addition to the risk factors described in this section, factors that may cause the market price of our common stock to fluctuate include, but are not limited to:

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In addition, if securities class action litigation is initiated against us, we would incur substantial costs and our management’s attention would be diverted from operations. All of these factors could cause the price of our stock to decline, and you may lose some or all of your investment.

Moreover, the stock markets in general have experienced substantial volatility that has often been unrelated to the operating performance of individual companies. These broad market fluctuations may also adversely affect the trading price of our common stock.

In the past, following periods of volatility in the market price of a company’s securities, stockholders have often instituted class action securities litigation against such company. Such litigation, if instituted, could result in substantial costs and diversion of management attention and resources, which could significantly harm our profitability and reputation.

We do not expect to pay cash dividends for the foreseeable future, and accordingly, stockholders must rely on stock appreciation for any return on their investment in the company.

We anticipate that we will retain our earnings, if any, for future growth and therefore do not anticipate that we will pay cash dividends for the foreseeable future. As a result, appreciation of the price of our common stock is the only potential source of return to stockholders. Investors seeking cash dividends should not invest in our common stock.

If equity research analysts cease to publish research or reports about our business or if they issue unfavorable research or downgrade our common stock, the price of our common stock could decline.

Investors look to reports of equity research analysts for additional information regarding our industry and operations and rely in part on the research and reports that equity research analysts publish about us and our business. We do not control these analysts. Equity research analysts may elect to cease research coverage of our common stock, which may adversely affect the market price of our common stock. The price of our common stock could decline if one or more of these analysts downgrade the common stock or if they issue other unfavorable commentary about us or our business.

Some provisions of our charter documents and Delaware law may have anti-takeover effects that could discourage an acquisition of us by others, even if an acquisition would be beneficial to our stockholders.

Provisions in our restated certificate of incorporation and bylaws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us, even if doing so would benefit our stockholders. These provisions include:

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In addition, we are subject to Section 203 of the Delaware General Corporation Law, which generally prohibits a Delaware corporation from engaging in any of a broad range of business combinations with an interested stockholder for a period of three years following the date on which the stockholder became an interested stockholder, unless such transactions are approved by such corporation’s board of directors. This provision could have the effect of delaying or preventing a change of control, whether or not it is desired by or beneficial to our stockholders.

Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to equity incentive plans, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.

Sales of a substantial number of shares of our common stock in the public market or the perception that these sales might occur, could depress the market price of our common stock and could impair our ability to raise capital through the sale of additional equity securities. We are unable to predict the effect that sales may have on the prevailing market price of the common stock.

To the extent we raise additional capital by issuing equity securities, including in a debt financing where we issue convertible notes or notes with warrants, our stockholders may experience substantial dilution. We may sell common stock in one or more transactions at prices and in a manner we determine from time to time. If we sell common stock in more than one transaction, existing stockholders may be materially diluted. In addition, new investors could gain rights superior to existing stockholders, such as liquidation and other preferences. We have stock options and warrants outstanding to purchase shares of our capital stock. Our stockholders will incur dilution upon exercise of any outstanding stock options or warrants.

Item 1B.    Unresolved Staff Comments.

Not applicable.

Item 2.    Properties.

Our principal executive offices are located in a 47,000 square foot facility located in St. Paul, Minnesota. We have leased this facility through November 2012 with an option to renew through November 2017. This facility accommodates our research and development, sales, marketing, manufacturing, finance and administrative activities.

In September 2009, we entered into an agreement to lease a 46,000 square foot production facility in Pearland, Texas beginning on April 1, 2010. We have leased this facility through March 2020. This facility primarily accommodates additional manufacturing activities.

We believe that our current premises are substantially adequate for our current and anticipated future needs for the foreseeable future.

Item 3.    Legal Proceedings.

Dr. Leonid Shturman Claim

On October 27, 2009, Dr. Leonid Shturman, CSI-MN’s founder, filed a complaint (the “First Complaint”) in the U.S. District Court in Minnesota (the “Court”) against us. The First Complaint asserted that our filing of an action in Switzerland against Dr. Shturman violated provisions of a settlement agreement that we and Dr. Shturman entered into in September 2008. The 2008 settlement resolved a lawsuit we had brought against Dr. Shturman for breach of his employment agreement with us. Dr. Shturman’s complaint sought an award of damages and injunctive relief to bar us from litigating the action in Switzerland. Dr. Shturman died subsequent to the filing of the complaint. Within three months of Dr. Shturman’s death, demands for settlement were made on behalf of the sole heir of Dr. Shturman’s estate, his wife, Leila Nadirashvili (“Mrs. Shturman”). We declined Mrs. Shturman’s demands. Thereafter, there was no activity for approximately nine months.

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Earlier this year, the Court issued an order requesting counsel for Dr. Shturman to advise the Court regarding the status of the First Complaint. Subsequent to the Court’s order, Mrs. Shturman again began making demands for money in exchange for Dr. Shturman’s alleged patent portfolio. We again declined Mrs. Shturman’s demands but instead made our own offer of settlement. Counsel for Mrs. Shturman rejected the offer and instead informed us that they intend to file an amended complaint in the U.S. District Court in Minnesota.

On August 24, 2011, instead of filing an amended complaint, Mrs. Shturman filed a second complaint in federal court seeking a declaration regarding ownership of the patent portfolio that she claims belongs to Dr. Shturman, slander by us of title to patent rights, tortious interference with prospective business relations, breach of settlement contract, and statutory unfair competition. Also, Mrs. Shturman filed a motion to be substituted in the First Complaint. We intend to file a motion in opposition to Mrs. Shturman’s motion to be substituted to have the First Complaint dismissed.

In addition, Mrs. Shturman filed a writ to dismiss our Switzerland lawsuit based on res judicata and collateral estoppel, alleging that the claims in Switzerland are identical to the previously dismissed lawsuit in Minnesota. Our counsel in Switzerland has filed a response to the motion to dismiss stating that the claims in Switzerland are not subject to res judicata. In particular, we reserved the rights in the previously dismissed Minnesota lawsuit to assert claims to an invention included in the patents filed in Switzerland by Dr. Shturman.

Michael Kallok Claim

On July 18, 2011, we received a demand letter from legal counsel for Michael Kallok, a former officer, director and consultant to us, claiming that Mr. Kallok is entitled to 42,594 shares of our common stock or, alternatively, the value of those shares as of July 15, 2011, which was $610,798. Mr. Kallok asserts that we improperly deemed such shares forfeited under a restricted stock agreement with Mr. Kallok. This matter is proceeding to arbitration.

We are defending this claim vigorously, and believe that an adverse outcome of this dispute would not have a materially adverse effect on our business, operations, cash flows or financial condition. We have not recognized any expense related to the settlement of this matter as we believe an adverse outcome of this action is not probable.

Executive Officers of the Registrant.

The names, ages and positions of our executive officers are as follows:

David L. Martin, President and Chief Executive Officer.    Mr. Martin has been our President and Chief Executive Officer since February 2007, and a director since August 2006. Mr. Martin also served as our Interim Chief Financial Officer from January 2008 to April 2008. Prior to joining us, Mr. Martin was Chief Operating Officer of FoxHollow Technologies, Inc. from January 2004 to February 2006, Executive Vice President of Sales and Marketing of FoxHollow Technologies, Inc. from January 2003 to January 2004, Vice President of Global Sales and International Operations at CardioVention Inc. from October 2001 to May 2002, Vice President of Global Sales for RITA Medical Systems, Inc. from March 2000 to October 2001 and Director of U.S. Sales, Cardiac Surgery for Guidant Corporation from September 1999 to March 2000. Mr. Martin has also held sales and sales management positions for The Procter & Gamble Company and Boston Scientific Corporation.

Laurence L. Betterley, Chief Financial Officer.    Mr. Betterley joined us in April 2008 as our Chief Financial Officer. Previously, Mr. Betterley was Chief Financial Officer at Cima NanoTech, Inc. from May 2007

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to April 2008, Senior Vice President and Chief Financial Officer of PLATO Learning, Inc. from June 2004 to January 2007, Senior Vice President and Chief Financial Officer of Diametrics Medical, Inc. from 1996 to 2003, and Chief Financial Officer of Cray Research Inc. from 1994 to 1996.

James E. Flaherty, Chief Administrative Officer and Secretary.    Mr. Flaherty has been our Chief Administrative Officer since January 14, 2008. Mr. Flaherty was our Chief Financial Officer from March 2003 to January 14, 2008. As Chief Administrative Officer, Mr. Flaherty reports directly to our Chief Executive Officer and has responsibility for information technology, facilities, legal matters, financial analysis of business development opportunities and business operations. Prior to joining us, Mr. Flaherty served as an independent financial consultant from 2001 to 2003 and Chief Financial Officer of Zomax Incorporated from 1997 to 2001 and Racotek, Inc. from 1990 to 1996. On June 9, 2005, the Securities and Exchange Commission filed a civil injunctive action charging Zomax Incorporated with violations of federal securities law by filing a materially misstated Form 10-Q for the period ended June 30, 2000. The SEC further charged that in a conference call with analysts, certain of Zomax’s executive officers, including Mr. Flaherty, misrepresented or omitted to state material facts regarding Zomax’s prospects of meeting quarterly revenue and earnings targets, in violation of federal securities law. Without admitting or denying the SEC’s charges, Mr. Flaherty consented to the entry of a court order enjoining him from any violation of certain provisions of federal securities law. In addition, Mr. Flaherty agreed to disgorge $16,770 plus prejudgment interest and pay a $75,000 civil penalty.

Kevin Kenny, Executive Vice President of Sales and Marketing.    Mr. Kenny joined us in May 2011 as Executive Vice President of Sales and Marketing. From 2002 to 2011, Mr. Kenny served in various positions with Medtronic Inc.’s U.S. Spine and Biologics division, including Vice President of Sales. Previously, Mr. Kenny served as Vice President of U.S. sales for Bausch and Lomb and held various sales and marketing leadership roles with B. Braun/McGaw and Smithkline Beecham.

Paul Koehn, Vice President of Quality and Operations.    Mr. Koehn joined us in March 2007 as Director of Manufacturing and was promoted to Vice President of Quality and Manufacturing in October 2007. In August 2011, Mr. Koehn became Vice President of Quality and Operations. Previously, Mr. Koehn was Vice President of Operations for Sewall Gear Manufacturing from 2000 to March 2007 and before joining Sewall Gear, Mr. Koehn held various quality and manufacturing management roles with Dana Corporation.

Robert J. Thatcher, Executive Vice President.    Mr. Thatcher joined us as Senior Vice President of Sales and Marketing in October 2005 and became Vice President of Operations in September 2006. Mr. Thatcher became Executive Vice President in August 2007. Previously, Mr. Thatcher was Senior Vice President of TriVirix Inc. from October 2003 to October 2005. Mr. Thatcher has more than 29 years of medical device experience in both large and start-up companies. Mr. Thatcher has held various sales management, marketing management and general management positions at Medtronic, Inc., Schneider USA, Inc. (a former division of Pfizer Inc.), Boston Scientific Corporation and several startup companies.

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PART II

Price Range of Common Stock and Dividend Policy

Prior to the closing of the merger on February 25, 2009, the stock of Replidyne was traded on the Nasdaq Global Market under the symbol “RDYN.” On February 26, 2009, the stock of CSI began trading on the Nasdaq Global Market under the symbol “CSII.” The following table sets forth the high and low sales prices for our common stock (based upon intra-day trading) as reported by the Nasdaq Global Market:

The number of record holders of our common stock on August 30, 2011 was approximately 584. No cash dividends have been previously paid on our common stock and none are anticipated during fiscal year 2012. We are restricted from paying dividends under our Loan and Security Agreements with Silicon Valley Bank and Partners for Growth.

Recent Sales of Unregistered Securities

None.

Issuer Purchases of Equity Securities

None.

Securities Authorized For Issuance Under Equity Compensation Plans

For information on our equity compensation plans, refer to Item 12, “Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.”

Item 7.    Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of financial condition and results of operations together with our consolidated financial statements and the related notes included elsewhere in this Form 10-K. This discussion and analysis contains forward-looking statements about our business and operations, based on current expectations and related to future events and our future financial performance, that involve risks and uncertainties. Our actual results may differ materially from those we currently anticipate as a result of many important factors, including the factors we describe under “Risk Factors” and elsewhere in this Form 10-K.

OVERVIEW

We are a medical device company focused on developing and commercializing interventional treatment systems for vascular disease. Our primary products, the Diamondback 360° PAD System (“Diamondback 360°”), Diamondback Predator 360° PAD System (“Predator 360°”) and Stealth 360° PAD System (“Stealth 360°”), are catheter-based platforms capable of treating a broad range of plaque types in arteries throughout the leg and

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address many of the limitations associated with existing treatment alternatives. We also intend to pursue approval of our products for coronary use. We refer to the Diamondback 360°, Predator 360° and Stealth 360° collectively in this report as the “PAD Systems.”

We were incorporated as Replidyne, Inc. in Delaware in 2000. On February 25, 2009, Replidyne, Inc. completed its business combination with Cardiovascular Systems, Inc., a Minnesota corporation (“CSI-MN”), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of November 3, 2008 (the “Merger Agreement”). Pursuant to the Merger Agreement, CSI-MN continued after the merger as the surviving corporation and a wholly-owned subsidiary of Replidyne. Replidyne changed its name to Cardiovascular Systems, Inc. (“CSI”) and CSI-MN merged with and into CSI, with CSI continuing after the merger as the surviving corporation. These transactions are referred to herein as the “merger.” Unless the context otherwise requires, all references herein to the “Company,” “CSI,” “we,” “us” and “our” refer to CSI-MN prior to the completion of the merger and to CSI following the completion of the merger and the name change, and all references to “Replidyne” refer to Replidyne prior to the completion of the merger and the name change. Replidyne was a biopharmaceutical company focused on discovering, developing, in-licensing and commercializing anti-infective products.

At the closing of the merger, Replidyne’s net assets, as calculated pursuant to the terms of the Merger Agreement, were approximately $36.6 million as adjusted. As of immediately following the effective time of the merger, former CSI stockholders owned approximately 80.2% of the outstanding common stock of the combined company, and Replidyne stockholders owned approximately 19.8% of the outstanding common stock of the combined company.

CSI was incorporated in Minnesota in 1989. From 1989 to 1997, we engaged in research and development on several different product concepts that were later abandoned. Since 1997, we have devoted substantially all of our resources to the development of the PAD Systems.

From 2003 to 2005, we conducted numerous bench and animal tests in preparation for application submissions to the FDA. We initially focused our testing on providing a solution for coronary in-stent restenosis, but later changed the focus to PAD. In 2006, we obtained an investigational device exemption from the FDA to conduct our pivotal OASIS clinical trial, which was completed in January 2007. The OASIS clinical trial was a prospective 20-center study that involved 124 patients with 201 lesions.

In August 2007, the FDA granted us 510(k) clearance for the use of the Diamondback 360° as a therapy in patients with PAD. We commenced commercial introduction of the Diamondback 360° in the United States in September 2007. We were granted 510(k) clearance of the Predator 360° in March 2009 and Stealth 360° in March 2011. We market the PAD Systems in the United States through a direct sales force and expend significant capital on our sales and marketing efforts to expand our customer base and utilization per customer. We assemble at our facilities the saline infusion pump used with our Stealth 360° product and the single-use catheter used in the PAD Systems with components purchased from third-party suppliers, as well as with components manufactured in-house. The control unit and guidewires are purchased from third-party suppliers.

As of June 30, 2011, we had an accumulated deficit of $162.4 million. We expect our losses to continue but generally decline as revenue grows from continued commercialization activities, development of additional product enhancements, accumulation of clinical data on our products, and further regulatory submissions. To date, we have financed our operations primarily from the issuance of common and preferred stock, convertible promissory notes, and debt.

FINANCIAL OVERVIEW

Revenues.    We derive substantially all of our revenues from the sale of PAD Systems and other ancillary products. The PAD Systems each use a disposable, single-use, low-profile catheter that travels over our proprietary ViperWire guidewire. The Diamondback 360° and Predator 360° PAD Systems use an external control unit that powers the system, while the Stealth 360° PAD System uses a saline infusion pump as a power supply for the operation of the catheter. Our ancillary products include the ViperSlide™ Lubricant and ViperTrack™ Radiopaque Tape. We also have an exclusive distribution agreement with Asahi-Intecc, Ltd. to market its peripheral guide wire line in the United States.

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Cost of Goods Sold.    We assemble the single-use catheter with components purchased from third-party suppliers, as well as with components manufactured in-house. The control unit and guidewires are purchased from third-party suppliers. Our cost of goods sold consists primarily of raw materials, direct labor, and manufacturing overhead.

Selling, General and Administrative Expenses.    Selling, general and administrative expenses include compensation for executive, sales, marketing, finance, information technology, human resources and administrative personnel, including stock-based compensation. Other significant expenses include travel and marketing costs and professional fees.

Research and Development.    Research and development expenses include costs associated with the design, development, testing, enhancement and regulatory approval of our products. Research and development expenses include employee compensation including stock-based compensation, supplies and materials, patent expenses, consulting expenses, travel and facilities overhead. We also incur significant expenses to operate clinical trials, including trial design, third-party fees, clinical site reimbursement, data management and travel expenses. All research and development expenses are expensed as incurred.

Interest and Other Income (Expense).    Interest and other income (expense) primarily includes interest expense (net of premium and discount amortization), interest income, change in the fair value of conversion option, net write-offs upon conversion (option and unamortized premium), decretion of redeemable convertible preferred stock warrants, and gain on investments.

Decretion (Accretion) of Redeemable Convertible Preferred Stock.    Decretion (accretion) of redeemable convertible preferred stock reflected the change in the current estimated fair market value of the redeemable preferred stock on a quarterly basis, as determined by management and the board of directors. Decretion (accretion) was recorded as a decrease (increase) to redeemable convertible preferred stock in the consolidated balance sheet and a decrease (increase) to the loss attributable to common stockholders in the consolidated statement of operations. The redeemable convertible preferred stock was converted into common stock immediately prior to the effective time of the merger with Replidyne. As such, the preferred stockholders forfeited their liquidation preferences and we stopped recording decretion (accretion) as of the merger date.

Net Operating Loss Carryforwards.    We have established valuation allowances to fully offset our deferred tax assets due to the uncertainty about our ability to generate the future taxable income necessary to realize these deferred assets, particularly in light of our historical losses. The future use of net operating loss carryforwards is dependent on us attaining profitable operations and will be limited in any one year under Internal Revenue Code

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Section 382 due to significant ownership changes (as defined in Section 382) resulting from our equity financings. At June 30, 2011, we had net operating loss carryforwards for federal and state income tax reporting purposes of approximately $146.2 million, which will expire at various dates through fiscal 2031.

CRITICAL ACCOUNTING POLICIES AND SIGNIFICANT JUDGMENTS AND ESTIMATES

Our management’s discussion and analysis of our financial condition and results of operations are based on our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States. The preparation of our consolidated financial statements requires us to make estimates, assumptions and judgments that affect amounts reported in those statements. Our estimates, assumptions and judgments, including those related to revenue recognition, allowance for doubtful accounts, excess and obsolete inventory, debt conversion option, stock-based compensation, and preferred stock warrants are updated as appropriate at least quarterly. We use authoritative pronouncements, our technical accounting knowledge, cumulative business experience, judgment and other factors in the selection and application of our accounting policies. While we believe that the estimates, assumptions and judgments that we use in preparing our consolidated financial statements are appropriate, these estimates, assumptions and judgments are subject to factors and uncertainties regarding their outcome. Therefore, actual results may materially differ from these estimates.

Some of our significant accounting policies require us to make subjective or complex judgments or estimates. An accounting estimate is considered to be critical if it meets both of the following criteria: (1) the estimate requires assumptions about matters that are highly uncertain at the time the accounting estimate is made, and (2) different estimates that reasonably could have been used, or changes in the estimate that are reasonably likely to occur from period to period, would have a material impact on the presentation of our financial condition, results of operations, or cash flows. We believe that the following are our critical accounting policies and estimates:

Revenue Recognition.    We sell the majority of our products via direct shipment to hospitals or clinics. We recognize revenue when all of the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred; the sales price is fixed or determinable; and collectability is reasonably assured. These criteria are generally met at the time of delivery when the risk of loss and title passes to the customer. We record estimated sales returns, discounts and rebates as a reduction of net sales in the same period revenue is recognized.

Costs related to products delivered are recognized in the period revenue is recognized. Cost of goods sold consists primarily of raw materials, direct labor, and manufacturing overhead.

Allowance for Doubtful Accounts.    We maintain allowances for doubtful accounts. This allowance is an estimate and is regularly evaluated for adequacy by taking into consideration factors such as past experience, credit quality of the customer base, age of the receivable balances, both individually and in the aggregate, and current economic conditions that may affect a customer’s ability to pay. Provisions for the allowance for doubtful accounts attributed to bad debt are recorded in general and administrative expenses.

Excess and Obsolete Inventory.    We have inventories that are principally comprised of capitalized direct labor and manufacturing overhead, raw materials and components, and finished goods. Due to the technological nature of our products, there is a risk of obsolescence to changes in our technology and the market, which is impacted by technological developments and events. Accordingly, we write down our inventories as we become aware of any situation where the carrying amount exceeds the estimated realizable value based on assumptions about future demands and market conditions. The evaluation includes analyses of inventory levels, expected product lives, product at risk of expiration, sales levels by product and projections of future sales demand.

Debt Conversion Option.    The fair value of the conversion option is related to the loan and security agreement with Partners for Growth and has been included as a component of debt conversion option and other assets on our balance sheet. The Monte Carlo option pricing model used to determine the value of the conversion option included various inputs including historical volatility, stock price simulations, and the assessed behavior of us and Partners for Growth based on those simulations.

Stock-Based Compensation.    We recognize stock-based compensation expense in an amount equal to the fair value of share-based payments computed at the date of grant. The fair value of all stock option and restricted stock awards and units are expensed in the consolidated statements of operations over the related vesting period. We calculate the fair value on the date of grant using a Black-Scholes model.

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To determine the inputs for the Black-Scholes option pricing model, we are required to develop several assumptions, which are highly subjective. These assumptions include:

Prior to the consummation of the merger, we used comparable public company data to determine volatility for option grants. Expected volatility is now based on the historical volatility of our stock. We use a weighted average calculation to estimate the time our options will be outstanding. We estimated the number of options that are expected to be forfeited based on our historical experience. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for the estimated life of the option. We use our judgment and expectations in setting future dividend rates, which is currently expected to be zero.

All options we have granted become exercisable over periods established at the date of grant. The option exercise price is generally not less than the estimated fair market value of our common stock at the date of grant, as determined by management and the board of directors.

The absence of an active market for our common stock prior to the merger required our management and board of directors to estimate the fair value of our common stock for purposes of granting options and for determining stock-based compensation expense. In response to these requirements, prior to the merger our management and board of directors estimated the fair market value of common stock at each date at which options are granted based upon stock valuations and other qualitative factors. Our management and board of directors conducted stock valuations using two different valuation methods: the option pricing method and the probability weighted expected return method. Both of these valuation methods took into consideration the following factors: financing activity, rights and preferences of our preferred stock, growth of the executive management team, clinical trial activity, the FDA process, the status of our commercial launch, our mergers and acquisitions and public offering processes, revenues, the valuations of comparable public companies, our cash and working capital amounts, and additional objective and subjective factors relating to our business. Our management and board of directors set the exercise prices for option grants based upon their best estimate of the fair market value of the common stock at the time they made such grants, taking into account all information available at those times. In some cases, management and the board of directors made retrospective assessments of the valuation of the common stock at later dates and determined that the fair market value of the common stock at the times the grants were made was different than the exercise prices established for those grants. In cases in which the fair market was higher than the exercise price, we recognized stock-based compensation expense for the excess of the fair market value of the common stock over the exercise price. Following the merger, our stock valuations are based upon the market price for our common stock.

Legal Proceedings.    In accordance with FASB guidance, we record a liability in our consolidated financial statements related to legal proceedings when a loss is known or considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or probable loss is a range, and no amount within the range is a better estimate than any other, the minimum amount of the range is accrued. If a loss is possible, but not known or probable, and can be reasonably estimated, the estimated loss or range of loss is disclosed in the notes to the consolidated financial statements. In most cases, significant judgment is required to estimate the amount and timing of a loss to be recorded. Our significant legal proceedings are discussed in Note 11 to the consolidated financial statements.

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RESULTS OF OPERATIONS

The following table sets forth, for the periods indicated, our results of operations expressed as dollar amounts (in thousands), and, for certain line items, the changes between the specified periods expressed as percent increases or decreases:

Comparison of Fiscal Year Ended June 30, 2011 with Fiscal Year Ended June 30, 2010

Revenues.    Revenues increased by $14.0 million, or 21.5%, from $64.8 million for the year ended June 30, 2010 to $78.8 million for the year ended June 30, 2011. This increase was attributable to an $11.5 million, or 20.1%, increase in sales of PAD Systems and a $2.4 million, or 32.0%, increase in sales of supplemental and other revenue during the year ended June 30, 2011 compared to the year ended June 30, 2010. Supplemental products include our Viper product line and distribution partner products. Currently, all of our revenues are in the United States; however, we may potentially sell internationally in the future. We expect our revenue to increase as we continue to increase the number of physicians using the devices, and increase the usage per physician as we continue to focus on physician education programs, introduce new and improved products, and generate clinical data.

Cost of Goods Sold.    Cost of goods sold increased by $1.3 million, or 8.5%, from $15.0 million for the year ended June 30, 2010 to $16.3 million for the year ended June 30, 2011. These amounts represent the cost of materials, labor and overhead for single-use catheters, guidewires, control units, pumps, and other supplemental products. The increase in gross margin from 76.9% during the year ended June 30, 2010 to 79.3% for the year ended June 30, 2011 was primarily due to operating efficiencies, product cost reductions, and a favorable product mix resulting in a reduction in shipments of lower margin control units. Cost of goods sold for the years ended June 30, 2011 and 2010 includes $312,000 and $548,000, respectively, for stock-based compensation. We expect that gross margin will slightly decline in the first half of fiscal 2012 due to Stealth 360° becoming a higher percentage of revenue, as the Stealth 360° has higher unit costs compared to the Diamondback 360° or Predator 360° due to lower production volumes. In addition, we expect the ramp-up of our second manufacturing facility in Texas, with higher future production capacity, will temporarily increase production costs but enhance efficiencies over time. We expect that gross margin in the second half of fiscal 2012 will be fairly consistent with fiscal 2011, although quarterly fluctuations could occur based on production volumes, timing of new product introductions, sales mix, pricing changes, or other unanticipated circumstances.

Selling, General and Administrative Expenses.    Selling, general, and administrative expense was $62.4 million for the years ended June 30, 2010 and June 30, 2011. Our selling, general and administrative expenses for

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the year ended June 30, 2011 have increased due to building our sales organization, along with increased professional fees offset by lower stock-based compensation. Selling, general, and administrative expenses for the years ended June 30, 2011 and 2010 includes $5.6 million and $7.3 million, respectively, for stock-based compensation. We expect our selling, general and administrative expenses to increase in the future due primarily to the costs associated with expanding our sales and marketing organization and programs to further commercialize our products, but at an annual rate less than revenue growth.

Research and Development Expenses.    Research and development expenses decreased by $1.4 million, or 13.0%, from $10.3 million for the year ended June 30, 2010 to $8.9 million for the year ended June 30, 2011. Research and development expenses relate to specific projects to improve our product or expand into new markets, such as the development of electric versions of the PAD Systems, shaft designs, crown designs, and PAD and coronary clinical trials. The reduction in these expenses related to the decreased numbers and sizes of PAD development projects in fiscal 2011, as well as the timing of those projects. Research and development expenses for the year ended June 30, 2011 and 2010 includes $587,000 and $1.3 million, respectively, for stock-based compensation. As we continue to expand our product portfolio within the market for the treatment of peripheral arteries and leverage our core technology into the coronary market, we generally expect to incur research and development expenses above amounts incurred for the year ended June 30, 2011; however, we expect these expenses to remain fairly consistent as a percentage of revenue. Fluctuations could occur based on the number of projects and studies and the timing of expenditures.

Interest and Other Income (Expense).    Interest and other income (expense) decreased by $1.3 million, or 130.4%, from ($1.0) million for the year ended June 30, 2010 to ($2.3) million for the year ended June 30, 2011. Significant changes in interest and other income (expense) during these periods included:

Net Loss Available to Common Stockholders.    Net loss available to common stockholders for the year ended June 30, 2011 was ($11.1) million, or ($0.70) per basic and diluted share, compared to ($23.9) million, or ($1.62) per basic and diluted share for the year ended June 30, 2010.

Comparison of Fiscal Year Ended June 30, 2010 with Fiscal Year Ended June 30, 2009

Revenues.    Revenues increased by $8.4 million, or 14.8%, from $56.5 million for the year ended June 30, 2009 to $64.8 million for the year ended June 30, 2010. This increase was attributable to a $6.1 million, or 11.8%, increase in sales of PAD Systems and a $2.3 million, or 45.0%, increase in sales of supplemental and other revenue during the year ended June 30, 2010 compared to the year ended June 30, 2009. Supplemental products include our Viper product line and distribution partner products, some of which have been introduced over the last year. All of our revenues were in the United States.

Cost of Goods Sold.    Cost of goods sold decreased by $1.2 million, or 7.4%, from $16.2 million for the year ended June 30, 2009 to $15.0 million for the year ended June 30, 2010. This decrease in cost of goods sold

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resulted in an increase to gross margin of six percentage points, from 71% for the year ended June 30, 2009 to 77% for the year ended June 30, 2010. These amounts represent the cost of materials, labor and overhead for single-use catheters, guidewires, control units, and other supplemental products. The increase in gross margin from the year ended June 30, 2009 to June 30, 2010 was primarily due to manufacturing efficiencies, product cost reductions, and a favorable product mix resulting in a reduction in shipments of lower margin control units. Cost of goods sold for the years ended June 30, 2010 and 2009 includes $548,000 and $475,000, respectively, for stock-based compensation.

Selling, General and Administrative Expenses.    Selling, general and administrative expenses increased by $2.6 million, or 4.4%, from $59.8 million for the year ended June 30, 2009 to $62.4 million for the year ended June 30, 2010. The primary reasons for the increase included increased sales and marketing expenses of $4.8 million from building our sales organization along with additional education programs, partially offset by reduced consulting and professional services, primarily from a $1.7 million write-off of previously capitalized initial public offering costs in fiscal 2009. Selling, general, and administrative expenses for the years ended June 30, 2010 and 2009 includes $7.3 million and $5.7 million, respectively, for stock-based compensation.

Research and Development Expenses.    Research and development expenses decreased by $4.4 million, or 30.0%, from $14.7 million for the year ended June 30, 2009 to $10.3 million for the year ended June 30, 2010. Research and development expenses relate to specific projects to improve our product or expand into new markets, such as the development of electric versions of the PAD Systems, shaft designs, crown designs, and PAD and coronary clinical trials. The reduction in these expenses related to the decreased numbers and sizes of PAD development projects in fiscal 2010, as well as the timing of those projects. Research and development expenses for the year ended June 30, 2010 and 2009 includes $1.3 million and $612,000, respectively, for stock-based compensation.

Interest and Other Income (Expense).    Interest and other income (expense) decreased by $3.3 million, or 143.0%, from income of $2.3 million for the year ended June 30, 2009 to expense of ($1.0) million for the year ended June 30, 2010. Significant changes in interest and other income (expense) during these periods included:

Decretion of Redeemable Convertible Preferred Stock.    Decretion of redeemable convertible preferred stock reflected the change in estimated fair value of preferred stock at the balance sheet dates. Decretion of redeemable convertible preferred stock for the year ended June 30, 2009 was $22.8 million. There was no decretion of redeemable convertible preferred stock during the year ended June 30, 2010 because all preferred stock was converted to common stock in conjunction with the merger.

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Net Loss Available to Common Stockholders.    Net loss available to common stockholders for year ended June 30, 2010 was $(23.9) million, or ($1.62) per basic and diluted share, compared to $(9.1) million, or ($1.13) per basic and diluted share for the year ended June 30, 2009.

NON-GAAP FINANCIAL INFORMATION

To supplement our consolidated condensed financial statements prepared in accordance with GAAP, our management uses a non-GAAP financial measure referred to as “Adjusted EBITDA.” The following table sets forth, for the periods indicated, a reconciliation of Adjusted EBITDA to the most comparable U.S. GAAP measure expressed as dollar amounts (in thousands):

The improvement in Adjusted EBITDA of $11.6 million, or 87.7%, is primarily the result of the $14.1 million, or 61.5%, improvement in the loss from operations. The loss from operations was significantly impacted by increases in revenue and gross margin, and a decrease in operating expenses, as discussed above.

Adjusted EBITDA was also impacted by a decrease in stock-based compensation and increase in depreciation and amortization. Stock-based compensation decreased $2.6 million, or 28.9%, from $9.1 million for the year ended June 30, 2010 to $6.5 million for the year ended June 30, 2011. Stock-based compensation decreased as a result of prior year charges for extending the terms of certain expired stock options. Depreciation and amortization increased as a result of additional investment in capital equipment.

Use and Economic Substance of Non-GAAP Financial Measures Used and Usefulness of Such Non-GAAP Financial Measures to Investors

We use Adjusted EBITDA as a supplemental measure of performance and believe this measure facilitates operating performance comparisons from period to period and company to company by factoring out potential differences caused by depreciation and amortization expense and non-cash charges such as stock-based compensation. Our management uses Adjusted EBITDA to analyze the underlying trends in our business, assess the performance of our core operations, establish operational goals and forecasts that are used to allocate resources and evaluate our performance period over period and in relation to our competitors’ operating results. Additionally, our management is partially evaluated on the basis of Adjusted EBITDA when determining achievement of their incentive compensation performance targets.

We believe that presenting Adjusted EBITDA provides investors greater transparency to the information used by our management for its financial and operational decision-making and allows investors to see our results “through the eyes” of management. We also believe that providing this information better enables our investors to understand our operating performance and evaluate the methodology used by our management to evaluate and measure such performance. Adjusted EBITDA is also used to measure performance in our financial covenants as required by Silicon Valley Bank and Partners for Growth.

The following is an explanation of each of the items that management excluded from Adjusted EBITDA and the reasons for excluding each of these individual items:

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Material Limitations Associated with the Use of Non-GAAP Financial Measures and Manner in which We Compensate for these Limitations

Non-GAAP financial measures have limitations as analytical tools and should not be considered in isolation or as a substitute for our financial results prepared in accordance with GAAP. Some of the limitations associated with our use of these non-GAAP financial measures are:

We compensate for these limitations by relying primarily upon our GAAP results and using non-GAAP financial measures only supplementally.

LIQUIDITY AND CAPITAL RESOURCES

We had cash and cash equivalents of $21.2 million and $23.7 million at June 30, 2011 and 2010, respectively. During the year ended June 30, 2011, net cash used in operations amounted to $8.4 million. As of June 30, 2011, we had an accumulated deficit of $162.4 million. We have historically funded our operating losses primarily from the issuance of common and preferred stock, convertible promissory notes, debt, and the merger with Replidyne in February 2009.

Loan and Security Agreement with Silicon Valley Bank

On March 29, 2010, we entered into an amended and restated loan and security agreement with Silicon Valley Bank. The agreement includes a $10.0 million term loan and a $15.0 million line of credit. The terms of each of these loans are as follows:

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Borrowings from Silicon Valley Bank are secured by all of our assets. The borrowings are subject to prepayment penalties and financial covenants, including maintaining certain liquidity and fixed charge coverage ratios and certain three-month EBITDA targets. We were in compliance with all financial covenants as of June 30, 2011. The agreement also includes subjective acceleration clauses which permit Silicon Valley Bank to accelerate the due date under certain circumstances, including, but not limited to, material adverse effects on our financial status or otherwise. Any non-compliance by us under the terms of our debt arrangements could result in an event of default under the Silicon Valley Bank loan, which, if not cured, could result in the acceleration of this debt.

Loan and Security Agreement with Partners for Growth

On April 14, 2010, we entered into a loan and security agreement with Partners for Growth III, L.P. (PFG). The agreement provides that PFG will make loans to us up to $4.0 million. The agreement has a maturity date of April 14, 2015. The loans bear interest at a floating per annum rate equal to 2.75% above Silicon Valley Bank’s prime rate, and such interest is payable monthly. The principal balance of and any accrued and unpaid interest on any notes are due on the maturity date and may not be prepaid by us at any time in whole or in part.

Under the agreement, PFG provided us with an initial loan of $1.5 million (the “initial loan”) on April 15, 2010. During the three months ended December 31, 2010, PFG, at its option, converted the entire $1.5 million (at par) into 276,243 shares of our common stock in accordance with the conversion terms set forth in the note for the initial loan. On December 3, 2010, and January 26, 2011, we issued PFG additional convertible notes under the agreement of $3.5 million and $500,000, respectively (“subsequent loans”). During the three months ended June 30, 2011, PFG, at its option, converted the $3.5 million subsequent loan (at par) into 362,320 shares of our common stock in accordance with the conversion terms set forth in the note for the subsequent loan. On June 30, 2011, we issued PFG an additional convertible note under the agreement of $3.5 million (the “current loans”). At any time prior to the maturity date, PFG may at its option convert the remaining $500,000 subsequent loan or the $3.5 million current loan into shares of our common stock at $12.40 or $13.64 per share, respectively, which equaled the ten-day volume weighted average price per share of our common stock prior to the issuance date of each note. We may also effect at any time a mandatory conversion of amounts, subject to certain terms, conditions and limitations provided in the agreement, including a requirement that the ten-day volume weighted average price of our common stock prior to the date of conversion is at least 15% greater than the conversion price. We may reduce the conversion price to a price that represents a 15% discount to the ten-day volume weighted average price of its common stock to satisfy this condition and effect a mandatory conversion. As a result of the various note issuances and conversions, we have reflected a net expense of $859,000 for the year ended June 30, 2011 as a component of interest and other, net on the accompanying statement of operations which represents the net effect of (i) the write-off of the conversion option on the initial loan and subsequent loan, (ii) the write-off of the unamortized debt premium on the initial and subsequent loan and (iii) the change in fair value of the conversion options on all loans. The balance outstanding under the loan and security agreement at June 30, 2011 was $4.6 million, including the net unamortized premium associated with our conversion option and related beneficial conversion feature. The balance outstanding under the loan and security agreement at June 30, 2010 was $1.3 million, including the net unamortized discount associated with the warrant and our conversion option.

On July 26, 2011, PFG at its option converted the remaining subsequent loan of $500,000 (at par) into 40,323 shares of our common stock in accordance with the conversion terms set forth in the note for the subsequent loan. We then subsequently issued PFG a new convertible note of $500,000. At any time prior to the maturity date, PFG may at its option convert the $500,000 note into shares of our common stock at $15.30 per share, which equaled the ten-day volume weighted average price per share of our common stock prior to the issuance date of the note.

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On August 23, 2011, the loan and security agreement was amended. The amended agreement provides that PFG will make loans to us up to $5.0 million. All other terms of the original agreement remain the same. We then subsequently issued PFG a new convertible note of $1.0 million, which increased the aggregate amount drawn under the loan and security agreement, as amended, to the full available amount of $5.0 million. At any time prior to the maturity date, PFG may at its option convert the $1.0 million note into shares of our common stock at $13.42 per share, which equaled the ten-day volume weighted average price per share of our common stock prior to the issuance date of the note.

The loans are secured by certain assets, and the agreement contains customary covenants limiting the our ability to, among other things, incur debt or liens, make certain investments and loans, effect certain redemptions of and declare and pay certain dividends on our stock, permit or suffer certain change of control transactions, dispose of collateral, or change the nature of our business. In addition, the PFG loan and security agreement contains financial covenants requiring us to maintain certain liquidity and fixed charge coverage ratios, and certain three-month EBITDA targets. We were in compliance with all financial covenants at June 30, 2011. If we do not comply with the various covenants, PFG may, subject to various customary cure rights, decline to provide additional loans, require amortization of the loan over its remaining term, or require the immediate payment of all amounts outstanding under the loan and foreclose on any or all collateral, depending on which financial covenants are not maintained.

In connection with the execution of the PFG loan and security agreement, we issued a warrant to PFG on April 14, 2010, which allows PFG to purchase 147,330 shares of our common stock at a price per share of $5.43, which price was based on the ten-day volume weighted average price per share of our common stock prior to the date of the agreement. The warrant was exercised in June 2011.

Cash and Cash Equivalents.    Cash and cash equivalents was $21.2 million and $23.7 million at June 30, 2011 and 2010, respectively. This decrease is primarily attributable net cash used in operations during the year ended June 30, 2011, partially offset by proceeds drawn on our convertible debt agreement.

Operating Activities.    Net cash used in operating activities improved 38.4% to $8.4 million from $13.6 million for the years ended June 30, 2011 and 2010, respectively. For the years ended June 30, 2011 and 2010, we had a net loss of $11.1 million and $23.9 million, respectively. Changes in working capital accounts also contributed to the net cash used in the years ended June 30, 2011 and 2010. Significant changes in working capital during these periods included:

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Investing Activities.    Net cash (used in) provided by investing activities was ($1.7) million and $21.8 million for the years ended June 30, 2011 and 2010, respectively. For the year ended June 30, 2011, cash (used in) investing activities resulted from investment in property plant, equipment, and patents. For the year ended June 30, 2010, cash provided by investing activities primarily resulted from the selling of investments in the amount of $23.0 million.

Financing Activities.    Net cash provided by (used in) financing activities was $7.5 million and ($17.9) million during the years ended June 30, 2011 and 2010, respectively. Cash provided by financing activities during these periods included:

Cash used in financing activities in these periods included:

Our future liquidity and capital requirements will be influenced by numerous factors, including the extent and duration of future operating losses, the level and timing of future sales and expenditures, the results and scope of ongoing research and product development programs, working capital required to support our sales growth, the receipt of and time required to obtain regulatory clearances and approvals, our sales and marketing programs, the continuing acceptance of our products in the marketplace, competing technologies and market and regulatory developments. As of June 30, 2011, we believe our current cash and cash equivalents and available debt will be sufficient to fund working capital requirements, capital expenditures and operations for at least the next 12 months. We intend to retain any future earnings to support operations and to finance the growth and development of our business, and we do not anticipate paying any dividends in the foreseeable future. We may raise additional capital in the future, to fund acceleration of our current growth initiatives or additional growth opportunities, if we believe it will significantly enhance our value.

Contractual Cash Obligations.    Our contractual obligations and commercial commitments as of June 30, 2011 are summarized below:

INFLATION

We do not believe that inflation has had a material impact on our business and operating results during the periods presented.

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OFF-BALANCE SHEET ARRANGEMENTS

Since inception, we have not engaged in any off-balance sheet activities as defined in Item 303(a)(4) of Regulation S-K.

RECENT ACCOUNTING PRONOUNCEMENTS

In May 2011, the FASB issued guidance to amend the accounting and disclosure requirements on fair value measurements. The new guidance limits the highest-and-best-use measure to nonfinancial assets, permits certain financial assets and liabilities with offsetting positions in market or counterparty credit risks to be measured at a net basis, and provides guidance on the applicability of premiums and discounts. Additionally, the new guidance expands the disclosures on Level 3 inputs by requiring quantitative disclosure of the unobservable inputs and assumptions, as well as description of the valuation processes and the sensitivity of the fair value to changes in unobservable inputs. The new guidance will be effective for us beginning January 1, 2012. Other than requiring additional disclosures, we do not anticipate material impacts on our consolidated financial statements upon adoption.

In June 2011, the FASB issued guidance requiring that all non-owner changes in stockholders’ equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. In the two-statement approach, the first statement should present total net income and its components followed consecutively by a second statement that should present total other comprehensive income, the components of other comprehensive income, and the total of comprehensive income. The new guidance will be effective for us beginning July 1, 2012. Other than requiring additional disclosures, we do not anticipate material impacts on our consolidated financial statements upon adoption.

PRIVATE SECURITIES LITIGATION REFORM ACT

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements. Such “forward-looking” information is included in this Form 10-K and in other materials filed or to be filed by us with the Securities and Exchange Commission (as well as information included in oral statements or other written statements made or to be made by us). Forward-looking statements include all statements based on future expectations. This Form 10-K contains forward-looking statements that involve risks and uncertainties, including our expectations regarding commercial launch of the Stealth 360° the adoption of the PAD Systems through our direct sales force; the use of the PAD Systems to treat coronary lesions and the potential market for this application in the interventional coronary market; our clinical trials and future presentations of clinical trial results; our plans to explore the acquisition of other product lines, technologies or companies and to continue to evaluate distribution agreements, licensing transactions and other strategic partnerships; future reimbursement for the PAD Systems; the possibility that we may sell internationally in the future; the conversion of and future capacity of our facilities; an increase in revenues; a temporarily increase in production costs; gross margins in the second half of fiscal 2012 will be fairly consistent with fiscal 2011; an increase in selling, general and administrative expenses; research and development expenses being above amounts incurred in fiscal 2011; no payment of dividends in the foreseeable future; and the sufficiency of our current and anticipated financial resources to fund operating expenses for at least the next 12 months. In some cases, you can identify forward-looking statements by the following words: “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “ongoing,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would,” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. Forward-looking statements are only predictions and are not guarantees of performance. These statements are based on our management’s beliefs and assumptions, which in turn are based on their interpretation of currently available information.

These statements involve known and unknown risks, uncertainties and other factors that may cause our results or our industry’s actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. These factors include regulatory developments in the U.S. and foreign countries; the experience of physicians regarding the effectiveness and reliability of the PAD Systems; the potential for unanticipated delays in enrolling medical centers and patients for

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clinical trials; actual clinical trial results; dependence on market growth; the reluctance of physicians to accept new products; the effectiveness of the Stealth 360° the difficulty of successfully managing operating costs; FDA clearances and approvals; the impact of competitive products and pricing; approval of products for reimbursement and the level of reimbursement; unanticipated developments affecting our estimates regarding expenses, future revenues and capital requirements; fluctuations in results and expenses based on new product introductions, sales mix, unanticipated warranty claims, and the timing of project expenditures; our inability to expand our sales and marketing organization and research and development efforts; our ability to obtain and maintain intellectual property protection for product candidates; our actual financial resources; general economic conditions; and those matters identified and discussed in Item 1A of this Form 10-K under “Risk Factors.”

You should read these risk factors and the other cautionary statements made in this Form 10-K as being applicable to all related forward-looking statements wherever they appear in this Form 10-K. We cannot assure you that the forward-looking statements in this Form 10-K will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. You should read this Form 10-K completely. Other than as required by law, we undertake no obligation to update these forward-looking statements, even though our situation may change in the future.

The primary objective of our investment activities is to preserve our capital for the purpose of funding operations while at the same time maximizing the income we receive from our investments without significantly increasing risk or availability. To achieve these objectives, our investment policy allows us to maintain a portfolio of cash equivalents and investments in a variety of marketable securities, including money market funds, U.S. government securities, and certain bank obligations. Our cash and cash equivalents as of June 30, 2011 include liquid money market accounts. Due to the short-term nature of these investments, we believe that there is no material exposure to interest rate risk.

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Item 8.    Financial Statements and Supplementary Data.

Index to Financial Statements

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Report of Independent Registered Public Accounting Firm

To the Board of Directors and Stockholders of

Cardiovascular Systems, Inc.

In our opinion, the accompanying consolidated balance sheets and the related consolidated statements of operations, of changes in stockholders’ equity (deficiency) and comprehensive loss and of cash flows present fairly, in all material respects, the financial position of Cardiovascular Systems, Inc. at June 30, 2011 and 2010, and the results of their operations and cash flows for each of the three years in the period ended June 30, 2011 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of June 30, 2011, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). The Company’s management is responsible for these financial statements, for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control over Financial Reporting included in item 9A. Our responsibility is to express opinions on these financial statements and on the Company’s internal control over financial reporting based on our audits (which was an integrated audit in 2011). We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements are free of material misstatement and whether effective internal control over financial reporting was maintained in all material respects. Our audits of the financial statements included examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ PricewaterhouseCoopers LLP

Minneapolis, MN

September 12, 2011

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Cardiovascular Systems, Inc.

Consolidated Balance Sheets

The accompanying notes are an integral part of these consolidated financial statements.

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Cardiovascular Systems, Inc.

Consolidated Statements of Operations