The reason the investigators are doing this study is to compare the results of laser atherectomy versus angioplasty with or without the placement of a stent in the artery. A stent is a metal tube used to open up narrow arteries in the body.

People with peripheral artery disease that has severely reduced blood flow in their lower leg are usually treated with surgical bypass. This condition is known as Critical Limb Ischemia or CLI. Over the last decade, advances in techniques and tools have allowed surgeons to more aggressively treat complex cases. Studies have shown successful treatment of CLI with endovascular techniques (less invasive surgical procedures through a small incision for the treatment of vascular disease), including laser atherectomy and angioplasty. Surgical guidelines are not clear as to the best procedure to use for CLI. To the best of our knowledge, a study comparing laser atherectomy and angioplasty has not been done. Laser atherectomy works by releasing ultraviolet light which is absorbed by the plaque in the arteries. This will then get rid of the plaque. Angioplasty is a procedure used to open blocked or narrowed arteries. Currently, it is not known if laser atherectomy has better results than angioplasty.

Inclusion Criteria:

• 18 years of age and older
• Male or female (non-pregnant females)
• Patients with peripheral artery disease that has progressed to critical limb ischemia (CLI)
• Patients undergoing angiography with possible intervention for Rutherford Class 4-6 limb ischemia that may benefit from revascularization