Update on the Role of the Distal Arteriovenous Fistula as an Adjunct for Improving Graft Patency and Limb Salvage Rates after Crural Revascularization

Background: Critical ischemia of the lower limb continues to challenge the ingenuity of all interventionalists in achieving reliable, predictable, and durable patency. The objective of this study was to investigate the role of the distal arteriovenous fistula (dAVF) to enhance crural revascularization patency rates particularly when prosthetics are used. Methods: All patients who underwent crural bypass with dAVF since 1979 were included. Graft patency was assessed periodically by clinical examination and Doppler studies. Results were analyzed by life-table methodology to obtain primary and secondary patency rates and limb salvage rates. Results: A total of 502 crural bypass plus dAVF procedures were studied within 4 consecutive periods. Primary patency rates at 1 and 3 years for each of the 4 consecutive periods were (1) 36% and 10%, (2) 52% and 15%, (3) 54% and 31%, and (4) 70% and 46%. Corresponding secondary patency rates were (1) 43% and 17%, (2) 60% and 29%, (3) 60% and 44%, and (4) 72% and 50%. There was a statistically significant improvement for primary and secondary patency rates when comparing the last 2 periods with the first 2. Limb salvage rates also showed significant improvement for the same periods. Conclusions: Creation of a dAVF should be considered as a component of crural revascularization when prosthetics are used. The altered hemodynamics associated with dAVF prevents overload and as a consequence, potential bypass closure. The contribution of dAVF for enhancing patency rates when autologous vein is used with compromised runoff requires further study.