At the 2016 Annual Scientific Meeting of the Society of Interventional Radiology, Dheeraj K. Rajan, MD, FRCPC, FSIR, from the University of Toronto in Toronto, Canada, presented a late-breaking abstract on 12- and 24-month follow-up data from the Fluency Plus Endovascular Stent Graft for In-stent Restenosis, called the RESCUE study, sponsored by C. R. Bard. Dr. Rajan spoke with Vascular Disease Management about these data.
VDM: Could you describe the design of the trial?
Rajan: RESCUE was a multicenter, prospective, randomized study conducted at 23 investigational sites. There were 275 patients enrolled in the study on an intent-to-treat basis that had an in-stent stenosis greater than 50% in the venous outflow circuit of a mature fistula or arteriovenous (AV) access graft. Exclusion criteria included thrombosis at the treatment site or stenoses in the cephalic arch or cannulation zone. The primary study endpoints were safety through 30 days and access circuit primary patency at 6 months. Patients were evaluated in office at 90 days and 6 months, and an angiogram was required at 90 days that was reviewed by an angiographic core laboratory. Additional follow-up through 24 months was completed either in office and/or by telephone interviews with the patient and dialysis center to determine whether there had been any adverse events or interventions since the time of the last visit and patency of the access.
VDM: What were some of the most important results?
Rajan:The study was designed to address the problem of in-stent stenosis in the dialysis access patient. In-stent stenosis is a very common problem for patients receiving hemodialysis, and there was no on-label approved device for treatment of in-stent stenosis at the time of the RESCUE trial. So this study aimed to address a very big problem experienced by dialysis patients in North America. The study evaluated the use of a covered stent, or stent graft to deal with intimal hyperplasia that migrates through stents, and to determine whether the device was as safe as and more effective than balloon angioplasty, the standard of care. The primary takeaways from this study were that at 6 months the stent graft patients demonstrated better overall access circuit and postintervention lesion patency compared to angioplasty, and use of the device was as safe as percutaneous transluminal angioplasty.
I presented access circuit and target lesion patency at 12 and 24 months. Beyond 6 months these were secondary outcomes, but it was still important to understand if there were longer-term benefits for these patients. There was a sustained benefit seen with the use of stent grafts compared to angioplasty for in-stent stenosis with the patency benefit extending through 24 months. Comparing both groups, some people might argue that stent grafts might be more dangerous for a variety of reasons, one of them being infection. We looked at adverse events through 24 months and there was no difference in safety events and adverse outcomes between angioplasty and stent grafts.
VDM: What do you think this means in practical terms for the interventionalist?
Rajan: In terms of applicability in practice, the study actually introduced a new tool to deal with a persistent problem. RESCUE demonstrated that the Fluency Plus stent graft was effective for treatment of in-stent stenosis in the AV access circuit. The study also showed that there was a potential longer term, sustained benefit of stent graft use.
Another thing the study examined was the index of patency function, meaning the number of times the access site requires intervention from initial intervention to the time of loss of access. So in 2 years, if you angioplasty every month or so, you can keep it open for 2 years, but how many times can you realistically intervene? With the Fluency Plus stent graft, through the 2-year period, the number of interventions was actually lower than angioplasty, so there was sustained benefit in terms of reduced interventions. So not only does it treat a disease process that’s present, but also it points out that use of this device does have a sustained benefit in terms of a reduced number of interventions over the life of the access.
VDM: Does that translate to reduced cost?
Rajan: Unfortunately, the RESCUE trial did not include a cost analysis and comparison. By maintaining access-circuit patency, however, and reducing the number of overall procedures needed to maintain access flow, you reduce the morbidity and mortality associated with reintervention, which indirectly reduces cost. Patients receiving hemodialysis are very sick and want to minimize their time in the access center or hospital. When they need an intervention, there’s always a chance of a complication; so reducing the number of overall interventions potentially reduces the risk to the patient and also hopefully reduces overall costs.
VDM: What is the most important takeaway message for an interventionalist?
Rajan: The most important takeaway message for the interventionalist is that there is now Level 1 clinical evidence that shows there is a device available to treat in-stent stenosis that provides a durable and safe result.
Editor’s note: Dr. Rajan reports consultancy to C. R. Bard.