Percutaneous transluminal angioplasty (PTA) is a minimally invasive technique for treatment of superficial femoropopliteal artery (SFA) obstructions or occlusions in patients with intermittent claudication as well as critical limb ischemia. Initial technical success rates of above 95% can be achieved and acceptably low rates of complications are consistently reported in the literature. There is a direct relation between treated vessel length and patency rates. One year patency of lesions longer than 10cm has only been 22% at one-year follow up. This major drawback limits a widespread applicability of PTA, and the indication of PTA particularly in patients with intermittent claudication is discussed controversially.With the introduction of endovascular stents, the problems of elastic recoil and residual stenoses due to arterial dissection could be resolved and initial reports of stenting for the treatment of occlusive atherosclerotic disease of the SFA showed promising results with primary and secondary patency rates of 87% to 90% after 18 months. However, subsequent studies demonstrated that exaggerated neo-intimal hyperplasia in the stented segment frequently leads to instent restenosis. This condition will be of greater importance with increasing number of stent implantation procedures during the last years. The concept of cutting balloon seems appealing for this indication, as the balloon-mounted microtomes guarantee smooth lumen gain within the stent, without the risk of vessel wall perforation. Initial reports of the use of the cutting balloon for the treatment of occlusive atherosclerotic disease of the SFA show promising results, indicating that the problems of elastic recoil and residual stenoses due to arterial dissection might be resolved. The cutting balloon has four tiny microtomes (< 0.1mm height) on the outside, which cut the fibrous plaque during expansion of the balloon. Consequently the problem of elastic recoil is ideally addressed, additionally less trauma is exercised on the vessel wall during dilatation of the balloon. This might be achieved by a reduction of vessel wall trauma, vessel wall inflammation and consequently reduced neointimal formation. Although the indications for CB-PTA in the SFA includes significant residual stenosis or in-stent restenosis, there are currently no published randomized controlled trials (RCT) comparing PTA vs. cutting balloon angioplasty (CB-PTA) for any specific condition. This lack of data led us to initiate a RCT comparing primary PTA vs.

CB-PTA for treatment of in-stent restenoses in patients with intermittent claudication or critical limb ischemia with TASC category A-B in the femoropopliteal artery .