Commentary: The Hybrid Vascular Graft

Since its inception in the 1960s, the autologous arteriovenous (AV) fistula has revolutionized the care of end-stage renal failure patients by providing a reliable high-flow, lowresistance conduit for hemodialysis. Since then, the dialysis population has grown considerably, along with significant improvements in dialysis technology. In the intervening period, synthetic AV grafts and tunneled dialysis catheters (TDC) became popular and were often used as a first choice over an autologous AV fistula in many countries. Historically, there have been significant international differences in practice, with European countries generally favoring autologous AV fistulas and North America favoring AV grafts. It has been shown that reliance on TDC for hemodialysis leads to increased morbidity and mortality compared with AV fistulas in large population studies. In 2003, following the recognition that AV fistulas conveyed an improved longevity with less risk of infection, the Fistula First initiative was born in the United States. Despite the advantages of promoting the use of autologous AV fistulas for dialysis, there are an increasing number of patients who are presenting with complex vascular access problems that often preclude the formation of an autologous AV fistula. This is not necessarily a direct result of poor planning or poor practice but is multifactorial due to extended indications for dialysis, with increased longevity of renal patients owing to improvements in nephrologic care and more options for endovascular maintenance and salvage of dysfunctional AV access. Vascular access problems in dialysis patients can include diseased arteries, but more often the venous aspects pose more of a challenge. Exhausted peripheral veins due to multiple failed fistulas and stenotic venous outflow secondary to multiple TDC often preclude the creation of AV fistulas and even AV graft insertion. This progression of increasing complexity of vascular anatomy requires paralleled creativity of the surgeon and radiologist in finding anatomic sites suitable for inflow and venous drainage. The development of novel devices has aided in this challenge, and one example is the Hybrid vascular graft (W.L. Gore & Associates, Flagstaff, AZ, USA). The Hybrid vascular graft is a polytetrafluoroethylene (PTFE) graft with a reinforced nitinol section, akin to a Viabahn stent-graft, that serves to avoid a true venous anastomosis and does not compromise future access sites. The graft component contains a covalently bonded heparin surface aimed at prolonging patency, and it is this portion of the device that forms the arterial interface. Overall, the device is designed to reduce intimal hyperplasia by improving hemodynamics and reducing vessel manipulation at the venous-graft interface. It also serves to expand treatment options for placing an AV graft in more challenging anatomic sites and deeper, more central vessels with its “over-the-wire” nature. To date, reports of the application of this device in dialysis access are limited to case reports. In this edition of the JEVT, Anaya-Ayala et al report a retrospective study of the application of the Hybrid graft compared with conventional PTFE grafts in a similar number of AV access patients with comparable challenging vascular anatomy. This is the largest published series to date reporting on the application of this device in AV access. In our opinion, the most important finding of this study is the demonstration of very good patency of the Hybrid graft out to 2 years. Recognizing the retrospective nature of this study and the relatively small patient numbers, statistically significant superior primary patency results were 600837 JETXXX10.1177/1526602815600837Journal of Endovascular TherapyJones and Inston research-article2015