BACKGROUND:

Expanded polytetrafluoroethylene (PTFE) has been used for infrainguinal revascularization when the saphenous vein is unavailable or unsuitable. Patency rates are, however, decidedly inferior to those with autologous vein, especially when anastomosed distally to the infrageniculate popliteal or tibial arteries. Although there are theoretical advantages to the use of reinforced grafts, the issue of external support for infrainguinal grafts has not been addressed in large clinical trials. Despite the insufficiency of data to support their use, externally supported PTFE grafts are widely used in clinical practice. This study attempts to determine whether or not external reinforcement of PTFE grafts affects patency when the graft crosses a joint in a canine arterial model. STUDY DESIGN:

Patency rates of standard PTFE prostheses were compared with those of externally supported PTFE across the hip joint in 19 mongrel dogs. In each animal, one limb was randomly assigned to receive standard PTFE and the other, externally supported PTFE. External iliac-superficial femoral artery grafts were constructed in a standardized fashion. At 12 to 16 weeks after implantation, graft patency was assessed by arteriography. RESULTS:

Thirteen animals (26 grafts) underwent angiographic evaluatIon of patency. Overall patency was 42 percent at 84 to 113 days. There was no statistically significant difference in patency between the two graft materials. CONCLUSIONS:

Intrinsic factors, rather than the presence or absence or external graft reinforcement, are the most important determinants of graft patency in this model. These data do not support the routine clinical use of externally reinforced PTFE grafts for infrainguinal revascularization.