[Results of in situ bypass].

The "in situ" bypass technique was adopted by our group in 1986. A total of 53 "in situ" bypasses were carried out until June 1989. The worst symptoms were incapacitating claudication, rest pain or ischemic necrosis, each in about one third of the patients. The site of the distal anastomosis was the popliteal artery below the knee in 40 instances, the peroneal artery in 7 and other infrapopliteal vessels in 6. Valve incisions were performed uneventfully with reusable instruments featuring a sharp-edged blade and an indicator for rotation control of the blade ("Insitutom RC"). Vein branches were located mostly by angiography, but residual arteriovenous fistula remained a vexing problem. In the beginning they were ligated under local anaesthesia. Later on they were dealt with successfully using transluminal embolization. Patients were last examined in July 1990 when the follow-up time ranged from 12 to 51 months. 4 patients had died and 5 were lost to follow-up. Patency rates were evaluated according to the life-table method. They were gratifying for femoro-popliteal bypasses with 87 percent after one year and 83 percent after two and three years. Femoro-tibial-peroneal bypasses performed below average, but their number was too small to draw conclusions.