Nonapposed stent graft size placement reduces edge stenosis in the peripheral outflow vein of hemodialysis patients.

Abstract

To evaluate the risk of edge stenosis in the peripheral outflow vein (OFV) of hemodialysis patients in association with apposed vs nonapposed stent graft placement. The indications of stent graft placement in this study were early recoil vascular stenosis or vascular peroration after balloon dilation in either arteriovenous graft or arteriovenous fistula patients. Only the stent end located within the peripheral OFV was included. The nonapposed patients were further divided into three groups as having received undersized, in-valve, or in-aneurysm placement. Endoprostheses 5 to 8 mm in diameter (Viabahn, or Covera) were used. Target lesion primary patency (TLPP), access circuit primary patency (ACPP) and secondary access patency were analyzed and reported. We retrospectively reviewed 138 patients (47 male and 91 female) with a total of 145 stent graft ends deployed in the peripheral OFV (arteriovenous graft: 79, arteriovenous fistula: 66). We classified 54 stent grafts as apposed and 91 as nonapposed (undersized, 51; in-valve, 25; in-aneurysm, 15). Technical and clinical successes were achieved in 100%. The median ACPP of the apposed and nonapposed patients were 3 and 6 months (P = .001). The median TLPP of the apposed and nonapposed groups were 6 and 26 months (P < .001) with 16 months in the undersized subgroup, 24 months in the in-valve subgroup, and not reached in the in-aneurysm subgroup (P = .003). In hemodialysis patients, nonapposed stent placements showed better TLPP rates, especially in the in-valve and in-aneurysm patient subgroups, which is contrary to the manufacturer's instructions for use and the results of some previosuly published articles.