Due to the results of interim analysis at the time 44 patients were recruited.

The aim of the study is to compare PTFE-graft bypass surgery versus Viabahn endoprosthesis for femoropopliteal arterial occlusion in intermittent claudication and critical ischaemia in patients who would be technically amenable for both treatments. The primary objective is to compare primary patencies of the two treatments. The secondary objective of the study is to evaluate secondary patency, functional status, the quality of life and costs of the new endovascular therapy.

Femoropopliteal bypass graft surgery with PTFE-prosthesis has proven to be an acceptable treatment for stable incapacitating claudication and critical ischaemia in patients with superficial femoral artery occlusion. Preliminary results of a thrupass endoprosthesis in the treatment of femoral lesions are promising. Less morbidity and better cost-effectiveness are suggested to be achieved in treatment of chronic lower limb ischaemia with endovascular treatment comparing to surgical treatment.

A randomised multicentre trial aims to enrol a pilot group of 60 + 60 patients to be followed for 3 years. Patients are treated either with Viabahn thrupass endoprosthesis (Gore corp.) or with 6 mm PTFE-prosthesis bypass graft surgery. Primary patency at three years is the primary end point and secondary patency, functional success, costs and quality of life are the secondary end points.

Inclusion Criteria:

1. Superficial femoral artery occlusion from 5 to 25 cm in length above the knee joint.
2. Patient must be equally eligible for both procedures.
3. Patient must present intermittent claudication with resistance to medical therapy and exercise or critical ischaemia.
4. Normal adjacent vessel diameter must be between 4.8 and 6.5 mm.
5. At least one patent distal run-off vessel and at least 1 cm of healthy superficial femoral artery below and above the lesion to allow proper placement of the endoprosthesis.
6. Patient must be 18 years or older.
7. Women of childbearing age must have negative pregnancy test prior to inclusion.

Exclusion Criteria:

1. Known allergy or contraindications to aspirin, clopidogrel, dipyridamole or anticoagulants.
2. Bleeding diatheses
3. Presence of one or several previously placed endoprosthesis or grafts in the superficial femoral artery segment.
4. Planned other endovascular therapy of the same segment.
5. Other than 6-7 mm diameter endoprosthesis or 6 mm PTFE-prosthesis is needed.
6. Presence of evolving malignant cancer or any other illness posing an immediate threat to life.
7. Life-expectancy less than 2 years due to co-morbidity or other situation that would make the patient unlikely candidate for follow-up visits.
8. Participation in another vascular clinical study less than 30 days prior to inclusion.
9. Patients unable to fill out the prescribed quality of life questionnaires themselves or unable to understand the full meaning of the informed consent.