Impact of Cuffed, Expanded Polytetrafluoroethylene Dialysis Grafts on Graft Outlet Stenosis

Abstract

The graft outlet stricture of cuffed ePTFE grafts for hemodialysis 3 months after implantation was less severe than that for the standard ePTFE graft. The correlation between the stricture level and dialysis graft patency requires further clarification.

A computational simulation of the effect of hybrid treatment for thoracoabdominal aortic aneurysm on the hemodynamics of abdominal aorta

“…The investigation of fluid dynamics in artery bypass graft (ABG) has pointed out that geometric factors including the anastomosis angle, the graft-to-host diameter ratio, surface irregularities and out-of-plane graft curvature are important parameters to affect the flow division in anastomoses and the hemodynamics in ABG 21 . In addition, it is reported that grafts featuring an extended patch or cuff may effectively provide a hood to ease the flow transition from the graft to the host which help to improve graft patency 22 . Furthermore, compliance mismatch has also been suggested as a cause for the bypass graft failure 23 .…”

Comparison of straight and Venaflo-type cuffed arteriovenous ePTFE grafts in an animal study

“…22 These findings correlate well with the reported early clinical results of the Venaflo graft that showed that the short-term prognosis could be improved as opposed to the straight graft. 4,15 However, the long-term prognosis of cuffed grafts is still very limited, since the grafts start to fail after a delayed time.…”

“…However, even for the latter the long-term patency rates are unsatisfactory. 4,15 The hemodynamics of an arteriovenous shunt anastomosis is intricate. Several computational and in vitro studies revealed the complex flow pattern of these rather nonphysiologic conjunctions of an arterial pulsatile high-pressure high-flow circulation with a venous low-pressure low-flow system.…”

Graft Modification Strategies to Improve Patency of Prosthetic Arteriovenous Grafts for Hemodialysis

“…Although some beneficial effects have been observed, the Venaflo™ graft did not seem to increase graft patency compared to control grafts. In one study, the Venaflo™ graft demonstrated a decrease in NIH formation (12). The lack of a beneficial effect on patency of the Venaflo™ graft can possibly be attributed to pseudo-intima formation in its cuff, which has been described in a Venaflo™ porcine model (6).…”

“…An animal study supported this potentially beneficial hemodynamic effect on the development of NIH; however, a high incidence of pseudo-intima formation was observed within the cuff leading to early graft dysfunction (6). Several retrospective analyses and randomized clinical trials (RCTs) comparing either the Venaflo™ graft or a PTFE graft with autologous venous cuff with a standard PTFE graft have been conducted; however, with modest results (7–12). Although some beneficial effects have been observed, the Venaflo™ graft did not seem to increase graft patency compared to control grafts.…”