Covered stents vs. PTA for ISR in AVGs and AVFs: Results from the RESCUE study

Despite the prevalence and morbidity conveyed by in-stent restenosis following bare-metal stent placement in hemodialysis access circuits, there has been limited evidence to guide optimal therapy. The RESCUE Study was the first prospective multicenter randomized, concurrently-controlled clinical trial designed to compare the efficacy and safety of expanded polytetrafluoroethylene (ePTFE) stent-grafts following balloon pre-dilation (n=132) versus percutaneous transluminal angioplasty (PTA) alone (n=143) for the treatment of venous outflow in-stent stenosis. Primary outcomes were access circuit primary patency (ACPP) at 6 months and freedom from complications through 30 days. The stent-graft group demonstrated significantly higher ACCP at 6 months, of 18.6% compared to 4.5% in the PTA group (p<0.001), an effect which was maintained to 12 months (6.2% vs. 1.5% respectively). These differences persisted when stratifying by access type (grafts versus fistulae) or stenosis location (peripheral versus central veins). A secondary outcome, treatment area primary patency (TAPP) at 6 months, was also significantly higher in the stent-graft (66.4%) versus PTA (12.3%) groups (p<0.001). There was no significant difference in the rate of safety events between treatment groups at 30 days (p<0.003) or through the full 24-month follow-up period. The investigators concluded that stent grafts provide superior primary patency than PTA alone for in-stent stenosis in AV grafts or native fistulae, for both peripheral and central veins, while maintaining a non-inferior safety profile to PTA.

Commentary

The RESCUE study serves as a well-designed and powered, comprehensive evaluation on the use of stent-grafts versus PTA alone to address in-stent restenosis for dialysis access circuits, an area which was previously under-investigated. The improved patency outcomes and absence of more frequent adverse events for stent-grafts compared to PTA in both fistulae and grafts provide strong support for their broader application in the setting of in-stent restenosis, and echoes favorable stent-graft outcomes seen in other locations in dialysis access circuits (i.e. venous anastomosis in RENOVA study). The cost efficacy of stent-grafts was not addressed in this study, but is an issue which necessitates future investigation, particularly when considering that the long-term ACCP rates remained very low (0.9% for stent-graft versus 0.8% for PTA at 24 months), despite concurrent improvements in TAPP. Nonetheless, the RESCUE study provides much needed evidence toward elucidating the optimal role of stent-grafts in dialysis access circuit preservation.



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Falk A, Maya ID, Yevzlin AS, Investigators R. A Prospective, Randomized Study of an Expanded Polytetrafluoroethylene Stent Graft versus Balloon Angioplasty for In-Stent Restenosis in Arteriovenous Grafts and Fistulae: Two-Year Results of the RESCUE Study. J Vasc Interv Radiol 2016; 27:1465-76.

Post Authors:

Jeffrey Forris Beecham Chick, MD, MPH
University of Michigan Hospital System

James X. Chen, MD
Hospital of the University of Pennsylvania