Assessment of a policy to reduce placement of prosthetic hemodialysis access

Background. The aim of this study was to evaluate the determinants of acces s patency and revision, including the effects of reducing the placement of prosthetic hemodialysis access. Methods. A retrospective cohort study of all hemodialysis accesses placed a t the Veteran's Administration Puget Sound Health Care System between 1992 and 1999 was conducted. A policy was instituted in 1996 that maximized the use of autogenous hemodialysis access. The impacts of the policy change, de mographics, and comorbid factors on access type and patency, were examined. Primary and secondary patency rates were examined using the Kaplan-Meier m ethod, and factors associated with failure and revision were examined using Cox proportional hazard models and Poisson regression. Results. During the study, 104 accesses (61 prosthetic grafts and 43 autoge nous fistulas) were placed prior to 1996, and 118 (31 prosthetic grafts and 87 autogenous fistulas) were placed after 1996. There was a significant in crease in autogenous fistulas placed after 1996 (87 out of 118) compared wi th before 1996 (43 out of 104, P < 0.001). At one year, autogenous fistulas demonstrated superior primary patency (56 vs. 36%, P = 0.001) and secondar y patency (72 vs. 58%, P = 0.003) compared with prosthetic grafts. After ad justment for age, race, side of access placement, and history of prior acce ss placement, patients with a prosthetic graft were estimated to experience a 78% increase in the risk of primary access failure when compared with si milar patients having an autogenous access [adjusted relative risk (aRR) = 1.78, 95% CI 1.21-2.62, P = 0.003)]. Similarly, the adjusted relative risk of secondary access failure for comparing prosthetic grafts with autogenous fistulas was estimated to be 2.21 (95% CI 1.38-3.54, P = 0.001). The adjus ted risk of access revision was 2.89-fold higher for prosthetic grafts than for autogenous fistulas (95% CI 1.88-4.44, P < 0.001). Conclusions. Autogenous conduits demonstrated superior performance when com pared with prosthetic grafts in terms of primary and secondary patency and number of revisions. A policy emphasizing the preferential placement of aut ogenous fistulas over prosthetic grafts may result in improved patency and a reduction in the number of procedures required to maintain dialysis acces s patency.