Cost efficacy of duplex surveillance and prophylactic angioplasty of arteriovenous ePTFE grafts

Poor patency of arteriovenous ePTFE grafts remains a major clinical problem. Prophylactic balloon angioplasty of stenoses has been claimed to prolong graft patency and has been widely introduced into practice. In this manuscript we report the cost incurred in application of such a program involving graft surveillance and prophylactic angioplasty of ePTFE graft stenoses >50% diameter. All patients in a single dialysis unit with ePTFE bridge grafts were subject to a surveillance duplex ultrasound and those with a perigraft stenosis of >50% then underwent angiography. Those patients confirmed to have a stenosis >50% within the graft, were randomized to prophylactic percutaneous transluminal angioplasty (PTA) versus no intervention (observation). Patients were followed every 3 months with ultrasound and those in the treatment group with recurrent stenosis (>50%) were subject to repeat PTA. The outcome was thrombosis. Relevant charges were considered to be: initial duplex screening of the entire ePTFE dialysis group; professional and technical fees for angiography and angioplasty; follow-up duplex scanning; repeat angioplasty; and costs of lytic therapy for an intraprocedure lysis. In the treatment and observation group the 6-month patencies were 69% +/- 7% and 70% +/- 7%, respectively. Twelve-month patencies for the treatment and observation groups were 51% +/- 6% and 47% +/- 4%. There was no significant difference between these two groups (p = 0.97), with an 80% confidence limit for detection of a difference >20%. Cost for duplex screening of all patients in the dialysis unit with ePTFE grafts was $40,440 (@ $337 each x 120 patients). Total charges for initial angiography was $178. Angioplasty charges were $143,040. Cost of the follow-up duplex ultrasound scanning in the treated group was $32,352. Charges for repeat angiograms in those with recurrent stenoses were $83,682 (professional fee $1733 + $229; technical fee + $820; equipment charges x 32 x 0.94). One patient required urokinase therapy for an occlusion following PTA. The overall charge for treating the 32 patients in the treatment arm of this study was $440,834, there was net improvement in patency. A policy of generic graft surveillance and prophylactic is expensive and does not lead to improved patency. Until an effective intervention is defined by prospective randomized trial, surveillance duplex scanning cannot be justified.