Determinants of successful synthetic hemodialysis vascular access graft placement.

Abstract

Synthetic vascular grafts, the most common type of permanent dialysis graft used in the United States, are associated with great morbidity and expense. In this cohort study of patients undergoing hemodialysis and receiving a new synthetic vascular graft, detailed intraoperative procedural data were examined as predictors of graft dysfunction and failure. A prospective cohort study of patients receiving hemodialysis who had undergone synthetic (polytetrafluoroethylene) graft placement over 4(1/2) years were followed up until either the graft was no longer usable, kidney transplantation was performed, the patient died, or the study ended. The principal methods of analysis used were the Kaplan-Meier method, to compute survival function for primary and secondary graft patency, and Cox proportional hazards regression, to model associations between predictor variables and graft failure. Of 284 patients enrolled in the study, 172 patients (61%) had at least one graft-related event, ie, temporary graft dysfunction or graft failure, during follow-up. Three-year cumulative graft survival was 54% (95% confidence interval, 45%-62%). Using proportional hazards analysis, history of claudication (rate ratio [RR], 2.14 [range, 0.97-4.73]; P =.06), number of previous permanent grafts (1 graft: RR, 1.49 [range, 0.88-2.51]; 2 or more grafts: RR, 2.85 [range, 1.43-5.69]; P =.01), dialysis dependency at surgery (RR, 2.96 [range, 1.23-7.12]; P =.02), and use of arterial clamps in construction of the graft (RR, 2.32 [range, 1.14-4.73]; P =.02) were associated with lower survival, even after accounting for medical history. Type of graft material, ie, Gore-Tex versus other material (RR, 0.28 [range, 0.16-0.50]; P <.01) and use of the axillary vein (RR, 0.61 [range, 0.36- 1.02]; P =.06) for the access site were associated with a lower rate of graft failure. Similar results were found with Poisson analysis of all graft-related events. In addition, acute arterial anastomosis, ie, arterial angle less than 90 degrees (RR, 0.63 [range, 0.45-0.91]; P =.01) and use of the brachial artery versus the radial artery (RR, 0.54 [range, 0.33-0.54]; P =.01) were associated with a lower rate of graft-related events. These findings suggest possible areas for intervention to improve synthetic vascular graft outcome.