RESUMO
The use of prosthetic conduits for lower extremity revascularization in the infrapopliteal location remains controversial. The objective of this report is to describe the immediate and long-term results in a series collected over two decades. Of the approximately 1,500 lower extremity revascularizations performed between 1978 and 1998, 81 infrapopliteal bypass cases using polytetrafluoroethylene (PTFE) as conduit in 77 patients were identified. Autogenous conduit was unavailable (86%) due to prior surgery: coronary artery bypass graft (25%), femoro-popliteal bypass (60%), or femoro-distal bypass (23%). All cases were done for critical ischemia using PTFE (6 mm, 95%; ring reinforced, 54%) under general (75%) or regional (25%) anesthesia. The distal anastomosis was to the anterior tibial artery (43%), posterior tibial artery (28%), tibioperoneal trunk (16%), or peroneal artery (12%), and vein patch was used in 25% of cases. Postoperative features included acute graft thrombosis in 11 cases (14%), all done under general anesthesia, perioperative death in 3 (4%), and a mean in-hospital stay of 17 days. Long-term follow-up has ranged from 1 to 144 months (mean, 22 months). At 36 months, primary patency was 20%, secondary patency 42%, and limb salvage 55% calculated by the Kaplan-Meier method. Univariate analyses revealed regional anesthesia was associated with prolonged primary patency (35% vs 15%, p=0.026) while the use of ring-reinforced PTFE conduit was associated with prolonged limb salvage (65% vs 40%, p=0.042). All other variables including gender, smoking, diabetes mellitus, renal failure, decade of operation, use of vein patch or postoperative warfarin were not significantly associated with either prolonged patency or limb salvage. Despite poor primary patency, distal prosthetic bypass can lead to long-term limb salvage. These data suggest distal anastomotic vein patches and postoperative anticoagulation may not be beneficial adjuncts. However, the use of regional anesthesia may decrease the incidence of perioperative thrombosis and the use of ring reinforced conduit may prolong limb salvage.
