The purpose of this study is to evaluate the safety and efficacy of an excimer laser in the treatment of patients with lower extremity vascular disease with chronic total occlusions.

The study is a multi center, prospective, non-randomized, open-label study conducted at a minimum of one investigational center. 50 subjects can be enrolled. Follow-up occurs at the end of the procedure in the form of an angiogram to determine if the lesion was crossed. Additional follow-up may not necessary because of the binary nature of the crossing, and also because any future follow-up would be assessing the effectiveness of adjunct therapy, e.g. balloon angioplasty. Long term results are entirely dependent on this subsequent treatment. Because the DABRA crosser only allows adjunct devices to be used, 30-day follow-up measuring the performance of the adjunct therapy might affect the physician's choice of therapy, and compromise the patient's treatment. Therefore, 30-day follow-up, which evaluates the effectiveness of the adjunct therapy, might raise ethical concerns. However, the follow-up can be done by Ankle-Brachial Index, Doppler ultrasound, auscultation, or by discussion of the level of claudication and motion pain with the patient. To evaluate the safety and efficacy of the RA-308 Excimer Laser System and DABRA Catheter for treating subjects with symptomatic infrainguinal lower extremity vascular disease with chronic total occlusions that cannot be crossed with standard guide wires, or lesions where an attempt to cross would, in the opinion of the interventionalist, result in either a subintimal path or a perforation.

Inclusion Criteria:

• signed informed consent
• symptomatic infrainguinal lower extremity vascular disease (Rutherford category 3, 4, 5 or 6), stable for at least 2 weeks prior to study inclusion
• lesions in the superficial femoral artery (SFA), popliteal, or infrapopliteal arteries at least one angiographically identifiable infrageniculate artery
• patients must be poor surgical candidates, indicated by at least one of the following conditions:
• absence of venous autologous grafts (that is, lack of a suitable vein to use for bypass)
• poor (diffusely diseased or <=1mm diameter) or no distal vessels available for graft anastamosis
• high risk of surgical mortality, evidenced by American Society of Anesthesiologists Physical Class 4 or higher

Exclusion Criteria:

• age below 18 years
• pregnancy, or plan to become pregnant
• participation in another cardiovascular or peripheral vascular study
• myocardial infarction (MI) in prior month
• stents at treatment site
• disorders or allergies precluding use of radiographic contrast
• renal insufficiency sever enough to contraindicate use of radiographic contrast
• contraindication to treatment with anticoagulants
• untreated ipsilateral iliac stenosis >70%
• inability or unwillingness of the patient to comply with intended examinations
• unavailability of required procedural or imaging equipment
• lesion located in a graft
• hemodynamically significant arrhythmia or left ventricular ejection fraction <20%
• life expectancy less than 6 months
• necrosis necessitating major amputation
• unwillingness of the patient to be anti-coagulated

subjects have a chronic total occlusion in the infrainguinal lower extremities

adverse event data was collected from the time of the procedure up to 6 months post-procedure