Femoro-popliteal and femoro-distal bypass: a comparison between in situ and reversed technique. The present report compares the in situ technique with that using the reversed vein for femoropopliteal bypass. In 1986 the in situ technique was introduced at our clinic as the preferred method for femoropopliteal bypass with the lower anastomosis below the knee or femorodistal bypass. Forty patients operated with the in situ technique were compared with an equal number of patients operated with the reversed technique 1983-1985. The two groups were comparable regarding concomitant cardiovascular and pulmonary disease, preoperative ankle-brachial index and level of distal anastomosis. Patency after 6 months was significantly higher (84%) for the in situ grafts compared to reversed veins (49%). The difference was mainly caused by a significantly higher patency for in situ grafts anastomosed to infrapopliteal arteries. Despite better patency rates in the in situ group limb salvage at 6 months was the same in both groups. Operating time was also similar in both groups. It is concluded that the in situ technique is superior to the reversed technique, at least in infrapopliteal reconstructions. The superior patency rate and the technical advantages without apparent disadvantages are the basis for the recommendation to use the in situ technique for femoropopliteal and femorodistal bypass. 