Composite grafts for critical ischaemia.

A total of 236 femoropopliteal below the knee and 64 femorotibial bypasses were carried out for critical ischaemia of the lower limbs using various prosthetic materials. These were evaluated in order to assess the patency of composite grafts (29 cases) compared with autogenous saphenous veins (189) and polytetrafluoroethylene (PTFE) (82). The composite graft was made by anastomosing a segment of autogenous vein in the distal position and joining it by an end-to-end oblique anastomosis to a PTFE prosthesis in the proximal position. These grafts were employed when an adequate autogenous vein could not be used for the entire length of the bypass. The graft-graft anastomosis was never placed near the knee-joint and if the PTFE segment had to cross the knee, it was always of the externally supported type. There were no early occlusions in the composite grafts. A total of 257 grafts were available for assessment at a mean of 4 years (range 6 months to 15 years). The patency for autologous saphenous vein was: 81.2% (121/142 femoropopliteal and 13/23 femorotibial). The patency for PTFE was 67.1% (41/58 femoropopliteal and 4/9 femorotibial) and for composite grafts was 76% (10/11 femoropopliteal and 9/14 femorotibial). There was no significant difference in patency between the autologous saphenous vein and the composite grafts, both in the femoropopliteal and femorotibial positions. Both were significantly better than PTFE grafts. Composite grafts are the best alternative when an autologous saphenous vein is not available.