Do distal arteriovenous fistulae improve patency rates of prosthetic infrapopliteal arterial bypasses?

We retrospectively analyzed if distal anastomotic adjunctive arteriovenous fistulae (AVF) improved patency rates of prosthetic bypasses to infrapopliteal arteries. Between July 1, 1991 and June 30, 1996, we performed 43 polytetrafluoroethylene (PTFE) bypasses to infrapopliteal (19 peroneal, 13 anterior tibial, 11 posterior tibial) arteries. All bypasses were performed for limb salvage when autologous vein was not available for a conduit. Adjunctive AVFs were performed in 21 bypasses (PTFE-AVF) and 22 bypasses did not have a fistula (PTFE-ONLY). Patients were allocated to the PTFE-AVF or PTFE-ONLY groups at the discretion of the surgeons, with adjunctive AVFs being performed for small arteries with poor run-off. There were no significant differences in age, sex, site of the proximal anastomosis, or indication for surgery (p > 0.05). There were statistically significant differences in the site of distal anastomosis and quality of arterial run-off based on the Society for Vascular Surgery Ad Hoc Committee on Reporting Standards criteria (p < 0.05). All patients were placed on heparin 500 units/hour postoperatively, maintained on life-long Coumadin and followed every 3 months with duplex ultrasonography to assess graft patency. Aggressive intervention was carried out for failing grafts suspected by duplex scanning. The hospital mortality rate was 2.3% (1/43; 1 PTFE-AVF). Two-year primary patency rates were significantly better for PTFE-AVF grafts than for PTFE-ONLY grafts (23% versus 5%) (p = 0.04). Although statistical significance was not reached, there was a suggestion of higher assisted primary (34% versus 1 5%) (p > 0.05) and secondary (61% versus 48%) (p > 0.05) patency rates in the PTFE-AVF group versus the PTFE-ONLY group, although limb salvage rates were similar (74% versus 71%) (p > 0.05). Two AVFs required ligation because of steal resulting in diminished distal perfusion. These results support the use of adjunctive distal AVFs to improve overall two-year patency rates of prosthetic infrapopliteal arterial bypasses.