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PHILADELPHIA -- A stent graft may improve vascular access patency in dialysis patients who've had stenosis in an original venous stent, researchers reported here.
In the RESCUE study, rates of access circuit primary patency were better over 6 months among patients who had a flexible stent graft placed inside the stenosed stent (16.7% versus 3%, P<0.001), , of the University of Wisconsin, and colleagues reported at .
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
"We found that the stent graft is far superior to angioplasty alone, which was previously the standard of care," Yevzlin told 鶹ý, saying the results should change practice. "This is level 1 evidence that stent grafts are superior to angioplasty alone."
About 5 years ago, Yevzlin said nephrologists started to see increasing use of bare metal stents for stenosis at vascular access sites, in both fistulas and grafts. Bare metal stents were being used because angioplasty alone has been limited in efficacy, it doesn't last long, and leads to other recurrent problems, he said.
But bare metal stents have also been linked to troubles like intimal hyperplasia and high restenosis rates. Lesions inside bare metal stents are more difficult to treat, he added, and can lead to thrombosis and other problems.
That's why Yevzlin and colleagues decided to test the , which can open blockages in previously placed stents on the venous side of the dialysis access circuit. The stent graft is placed inside the stent to reopen it, allowing for adequate blood flow and for dialysis to take place.
The graft is made of a flexible metal and lined with expanded polytetrafluoroethylene (ePTFE) plastic, and the goal is to reduce the risk of restenosis.
Yevzlin noted that an earlier study looked at this device, but only in arteriovenous grafts -- not fistulas -- and only at the location of the graft. The stent graft did show improved outcomes compared with angioplasty alone, Yevzlin said, but he and his team wanted to investigate these grafts in fistulas as well.
They enrolled 265 patients from 23 U.S. sites who had in-stent restenotic lesions in the venous outflow of their vascular access, and randomized them to angioplasty alone, or angioplasty plus the stent graft.
The primary endpoints were superiority of access circuit primary patency through 6 months and safety through 30 days, and a secondary endpoint was post-intervention lesion patency.
Ultimately 244 patients were evaluated for 30-day safety, and 220 patients were evaluated for 6-month effectiveness.
Yevzlin and colleagues found that patency of vascular access at 6 months was significantly higher in the stent graft group than in the angioplasty alone group (16.7% versus 3%, P<0.001).
Safety was similar: the percentage of patients free from safety events through 30 days was comparable between groups (96.6% for the stent graft group and 96.8% for the angioplasty alone group, P=0.007).
Post-intervention lesion patency was higher in stent graft group, they found (65.2% versus 10.4%, P<0.001) -- and this was true for patients whether they had a graft or a fistula:
- Graft: 57.7% versus 5.2%, P<0.001
- Fistula: 72% versus 14.7%, P<0.001
They also found that freedom from binary restenosis at 90 days was markedly higher in the stent graft group (81% versus 25%).
"This should change the first-line therapy for this disease state," Yevzlin told 鶹ý. "It will reduce the frequency with which patients need to be treated for in-stent restenosis."
Disclosures
Yevzlin disclosed no financial relationships with industry.
Primary Source
Kidney Week
Source Reference: Yevzlin AS, et al "Six-month results of the RESCUE trial: Fluency Plus endovascular stent graft versus PTA for in-stent restenosis" Kidney Week 2014; Late-Breaking Trials.