title: The effect of in-stent restenosis on hemodialysis access patency.
abstract: Endovascular stents have recently been shown to extend access patency in thrombosed and stenotic arteriovenous grafts (AVG). Concern remains over the frequency and severity of in-stent restenosis, though this has not been rigorously defined to date. The study was a retrospective analysis of hemodialysis patients referred for access dysfunction during a 2-year period. Using a prospectively collected, vascular access database, we identified 76 patients seen for follow-up angiography due to access dysfunction after stent placement. We compared the effect of in-stent restenosis vs. de novo lesions in patients with previously placed endovascular stents. Measured outcomes were primary assisted patency and frequency of in-stent and de novo lesions. Thirty-five (46.1%) patients had de novo lesions, while 41 (53.9%) had in-stent restenosis. In-stent restenosis was found to be the only factor associated with severity of luminal stenosis (beta=0.35, 95% confidence interval 2.21-15.48, P=0.01). In-stent restenosis was associated with increased primary patency among AVGs (hazards ratio 3.10; 95% confidence interval 1.35-7.10; P=0.008). Primary patency of in-stent restenosis vs. de novo lesions for AVGs were respectively: 78% vs. 94% at 1 month, 56% vs. 42% at 3 months, 33% vs. 6% at 6 months. For arteriovenous fistulae, the difference in primary patency of in-stent vs. de novo lesions was not statistically significant. In-stent restenosis is associated with higher percent luminal diameter lesions, while de novo lesions rather than in-stent restenosis are associated with higher risk of AVG access failure and reduced primary patency.
authors.affiliation: Department of Medicine, Division of Nephrology, University of Wisconsin, Madison, Wisconsin 53713, USA. mr.chan@hosp.wisc.edu
authors.forename: Micah R
authors.initials: MR
authors.lastname: Chan
authors.forename: Henry N
authors.initials: HN
authors.lastname: Young
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Yevzlin
mesh_terms: D000368:Aged; D019917:Blood Vessel Prosthesis Implantation; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D006435:Renal Dialysis / Q000379:methods; D012307:Risk Factors; D015607:Stents; D014654:Vascular Patency