Plain English Summary
Background and study aims
Atherosclerosis is a serious disease where a fatty substance, called plaque, builds up in the arteries. Over time, plaque causes hardening and narrowing of the arteries, which leads to reduced flow of blood through the blood vessels. Over time this can cause the main arteries in the legs, usually the femoral (thigh level) and/or popliteal (knee level) arteries, to become narrowed (stenosed) or blocked (occluded). This can cause a severe cramping pain in the legs when exercising, as the restricted blood flow cannot deliver enough oxygen to the leg muscles. As the arteries become narrower, patients begin the feel pain even when at rest and are at severe risk of developing ulcers or gangrene (critical limb ischaemia). At this point, the only viable treatment option is to surgically restore blood flow to the leg (revascularisation). This is done by either bypass surgery (where a superficial (close to the skin surface) vein is used to divert blood around the obstruction) or endovascular techniques (where the blocked artery is reopened using a balloon (angioplasty) and possibly held open with a mesh tube (stent) which is placed inside the artery). The current international guidelines (TransAtlantic Inter-Society Consensus, TASC II) recommend that short blockages (TASC II Type A and B) be treated using endovascular techniques and long blockages (TASC II Type C and D) of the femoral and/or popliteal arteries be treated using bypass surgery. Most patients prefer to have endovascular surgery as it is much less invasive however it is not known whether these techniques would be as effective as bypass surgery in long blockages. The aim of this study is to compare the effectiveness and complication rates of endovascular and bypass surgery in long blockages of the femoral and/or popliteal arteries.
Who can participate?
Patients aged 30 years or over who have blocked arteries in their lower legs which is causing them disabling claudication or critical limb ischaemia.
What does the study involve?
Participants are randomly allocated to one of two groups. Participants in the first group receive the standard bypass surgery. This involves the removal of the greater saphenous vein (superficial vein running from the foot to the upper thigh) from the affected leg, and attaching (grafting) it above and below the blockage so that the blood can go around it. Participants in the second group receive endovascular surgery. This involves a tube being placed inside the affected artery with a small balloon on the end. This balloon is then inflated to flatten the blockage up against the artery wall. A small mesh tube is then placed in the artery to keep it open. After the procedures, participants in both groups have an angiography (type of x-ray to see inside the blood vessels) in order to judge the success of the operation. Participants in both groups also have an ultrasound scan of their arteries at the start of the study, after 2 and 4 weeks and after 3, 6 and 12 months in order to monitor the patency (openness) of the arteries to make sure they are not becoming narrowed again (restenosis).
What are the possible benefits and risks of participating?
There are no specific benefits of taking part, as participants who receive surgery anyway. There are no specific risks of taking part other than the general risks associated with undergoing major surgery.
Where is the study run from?
Paracelsus Medical University Salzburg (Austria)
When is the study starting and how long is it expected to run for?
March 2016 to March 2021
Who is funding the study?
Paracelsus Medical University (Austria)
Who is the main contact?
Dr Klaus Linni
Dr Klaus Linni
Paracelsus Medical University
Müllner Hauptstraße 48
+43 662 4482 53201
Stent versus bypass for femoropopliteal TASC II Type C and D lesions: a prospective randomised trial
There will be no difference between percutaneous transluminal angioplasty (PTA) with stent and bypass operation regarding patency in patients undergoing revascularization of the lower limb due to TASC II Type C or D femoropopliteal lesions.
There is a difference between both therapies concerning patency rates.
Local research ethics committee, Salzburg (Austria), 30/09/2015, ref: 415-E/1938/3-2015
Prospective randomised parallel trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet.
Patients are allocated to one of two groups by computer generated randomizing. Block variables are TASC C lesions, TASC D lesions, Fontaine Stage IIb (intermittent claudication) and Fontaine Stage III+IV (critical limb ischemia).
Group 1: Participants receive a bypass operation with ipsilateral greater saphenous vein. The procedure is carried out in general anesthesia oder regional anesthesia. First arteries for proximal and distal anastomosis are exposed. Then the preoperatively marked ipsilateral greater saphenous vein is harvested via multiple vertical skin incisions with intervening cutaneous bridges. The vein is prepared for the bypass with ligation of side branches and lysis of vein valves with a valvulotome (a small hook). Before clamping of the arteries 70-100 IE/kg heparin are administered intravenously, followed by clamping and incision of the artery. The next step is the proximal anastomosis between artery and vein bypass. Thereafter the bypass is placed subcutaneously for the distal anastomosis. Afterwards the arterial clamps are removed to ensure bloodstrem to the distal artery and control the leakproofness of the anastomoses. At the end of the procedure a control angiography, bleeding control and wound closure are carried out. The procedure takes approximately three hours. After five to seven days the patient can leave the hospital.
Group 2: Participants receive a percutaneous transluminal angioplasty with stent placement. The procedure is carried out in local anesthesia in the operating room using a c-arm. After puncture of the ipsilateral or contralateral common femoral artery the guide wire and introducer sheath are inserted under fluoroscopy. Thereafter 5000 IE heparin are administered. In case of successfull passing of guidewire and catheter of the complicated femoropopliteal lesions predilatation takes place by balloon catheter followed by self expandable stent placement and post dilatation. Technical success is achived in case of reststenosis of less than 30 percent in completion angiography. After removing of the sheath the common femoral artery is sealed with a closure device. The procedure takes approximately one and a half hours. If the next 24 hours are uneventful, the patient can leave the hospital.
Post-operatively the patients receive aspirin 100 mg per day (Group 1) or aspirin 100 mg per day plus Clopidogrel 75 mg per day for six weeks (Group 2). During hospital stay the patients get low-molecular-weight heparin subcutaneously. The follow up in the outpatient clinic is performed after two and four weeks, 3, 6 and 12 months.
Primary outcome measure
1. Technical success is measured using control angiography at the end of the procedure
2. Primary and secondary patency is measured using clinical examination and ultrasound examination at baseline, 2 weeks, 4 weeks, 3 months, 6 months and 12 months
Secondary outcome measures
1. Local complications (e.g. surgical site infection, bleeding) are measured using clinical and ultrasound examination at baseline, 2 weeks, 4 weeks, 3 months, 6 months and 12 months. If extensive local complications computed tomography angiography is performed. For surgical site infections blood samples and samples for bacterial culture are taken.
2. Systemic complications (e.g. myocardial infarction, stroke) are measured using clinical examinations at baseline, 2 weeks, 4 weeks, 3 months, 6 months and 12 months
3. Limb salvage rate is determined using Kaplan Meier estimation at the end of the study
4. Survival rate is determined using Kaplan Meier estimation at the end of the study
5. Costs are calculated by the hospital's accounting department at the end of the study
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged 30 years and over
2. Peripheral arterial occlusive disease of the lower extremity due to atherosclerosis
3. Disabling claudication (walking distance < 200 m) or critical ischemia (rest pain and/or tissue loss)
4. Radiologically verified long lesions (TASC II Type C or D) of the femoral and/or politeal artery
5. Symptoms for more than 2 months
6. Unimpaired ipsilateral iliac arteries
7. Capacity to provide informed consent
Target number of participants
Participant exclusion criteria
1. Acute ischemia
2. Embolic occlusion of the femoropopliteal segment
4. Non-disabling claudication (walking distance > 200 m)
5. Radiologically verified short femoropopliteal lesions (TASC II Type A and B)
7. Renal insufficiency (glomerular filtration rate < 45 ml/min/1.73 m2)
8. No informed consent
10. Patient too frail for bypass surgery: American Society of Anesthesiologists (ASA) - Class >3
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Paracelsus Medical University Salzburg
Müllner Hauptstrasse 48
Paracelsus Medical University
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication of study results in a peer reviewed journal, with interim analysis after three years and end results after 5 years.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)