PURPOSE To develop an economic and efficient concept for more time-saving local rt-PA thrombolysis therapy. METHOD 40 patients with peripheral vascular occlusive disease stage IIb-III according to the Fontaine classification and with angiographically proven occluded segments of pelvic and lower limb arteries were treated by a modified concept of local rt-PA catheter thrombolysis. Via a thin guide wire the catheter for thrombolysis is slowly advanced through the thrombus without fluoroscopic control, outside the room in which angiography is performed. In 24 cases a short-term lysis and in 16 cases a long-term lysis was carried out. RESULTS The initial success rate was 75%, the patency rate in six months' follow-up was 66.7%. The ankle-brachial index decreased from 0.4 +/- 0.3 to 0.8 +/- 0.2 on the average. There were no relevant clinical complications. The average occupancy time of the angiography room or table was 60 +/- 52 min, the average time of fluoroscopy was 17 +/- 13 min. CONCLUSION In modified local rt-PA thrombolysis, short-term lysis and long-term lysis were mostly performed outside the angiography room, so that the exposure to radiation and there fore the radiation dose were reduced for both the patient and the attending staff. The angiography room is thus available for other patients and can therefore be used more efficiently.