A total of 85 occluded superficial femoral arteries were treated using the rotational transluminal angioplasty catheter system (ROTACS). The mean length of the occlusions was 7cm; 76% were uncalcified or only slightly calcified whereas 24% were calcified or highly calcified. The mean preoperative ankle:brachial index was 0.51. Primary success was achieved in 62 of 85 cases (73%). The mean length of reperfused occlusions was 6.2 cm: 26% of these lesions were calcified. The mean ankle:brachial index was 0.91. There were 23 primary failures (27%): reperfusion was impossible in 11 cases (including one complicated by perforation) and there were eight dissections, three cases where residual stenosis exceeded 50%, and one other unspecified failure. The mean length of these occlusions was 10.5 cm; 17% were calcified. Two patients developed a distal embolus and one died 10 days after reperfusion. The probability of primary patency of a reperfused artery was 44% at 1 year. Forty-two of the 62 patients who achieved primary success remained symptom free; the mean length of the original occlusion was 4.5 cm. Fifteen patients developed a new area of stenosis whereas five others exhibited new occlusion after a mean interval of 6 months. The mean length of these reperfused arteries was 9 cm. The probability of secondary patency at 1 year was 58%. Arterial calcification did not appear to influence the feasibility of reperfusion using the catheter. The main factor determining successful reperfusion was the length of the occlusal defect (P < 0.05). Reperfusion using the ROTACS did not improve the feasibility of reperfusion by conventional transluminal angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)