Arteriovenous graft configuration in hemodialysis: does it matter?

Abstract

The current guidelines for arteriovenous graft (AVG) configuration in hemodialysis state the following sequence: forearm loop, upper arm straight or curved and upper arm looped. These recommendations are based upon literature from the 1980s. Modern patient demographics and patient treatment algorithms, i.e., the Fistula First initiative (FFI), have greatly changed the current practice environment. It is not clear if these changes alter the outcomes of AVGs based upon configuration. The most recent National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF/K-DOQI) guidelines for vascular access were reviewed. Articles cited to support recommendations for AVG configuration were evaluated. The following search terms: arteriovenous graft configuration, access configuration, PTFE configuration in hemodialysis and straight, looped, curved graft configuration were used to search PubMed, Ovid, Medline and Google scholar. Articles that included data comparing AVG configuration were included. Citations within those articles were examined for publications overlooked in the initial search. Four articles and one abstract were reviewed and separated into pre- and post-FFI groups. Pre-FFI articles demonstrate superiority of forearm looped AVG over straight forearm grafts. Post-FFI, the literature suggests that primary patency, thrombosis and steal are not affected by configuration and location, although looped configuration may have superior secondary patency. The available literature is mixed regarding the effect of configuration on AVG outcomes. Current studies illustrate the effect may be limited and that larger randomized controlled trials are necessary to draw firm conclusions. Regardless, adequate inflow and an appropriately sized outflow vein are paramount for optimal graft performance.