Treatment of instent restenosis following stent‐supported renal artery angioplasty

Objectives: We prospectively studied the long‐term outcome of endovascular treatment of instent renal artery stenosis (IRAS). Background: Restenosis is a considerable drawback of stent‐supported angioplasty of renal artery stenosis especially in small vessel diameters. The appropriate treatment strategy is not yet defined. Patients and Methods: During a 10‐year period 56 consecutive patients (65 lesions) with their first IRAS were included in a prospective follow‐up program (mean follow‐up 53 ± 25 months, range 6–102). Primary endpoint of the study was the reoccurrence of IRAS (≥ 70%) after primarily successful treatment of the first IRAS determined by duplex ultrasound. Results: Primary success rate was 100%, no major complication occurred. Nineteen lesions were treated with plain balloon angioplasty (group 1, 30%), 42 lesions with stent‐in‐stent placement (group 2, 65%) using various bare metal balloon expandable stents, and 4 lesions with drug‐eluting stent angioplasty (group 3, 6%). During follow‐up, overall 21 lesions (32%) developed reoccurrence of IRAS: n = 7/19 in group 1 (37%), n = 14/42 in group 2 (33%), and n = 0/4 in group 3 (0%; P = 0.573). Reoccurrence of IRAS was more likely to occur in smaller vessel diameters than in larger ones [3–4mm: 4/7 (57%); 5 mm: 11/26 (42%); 6 mm: 5/25 (20%); 7 mm: 1/7 (14%), P = 0.088]. Multivariable analysis found bilateral IRAS and IRAS of both renal arteries of the same side in case of multiple ipsilateral renal arteries as independent predictors for reoccurrence of IRAS. Conclusion: Treatment of IRAS is feasible and safe. The data demonstrate a nonsignificant trend towards lower restenosis with restenting of IRAS versus balloon angioplasty of IRAS. Individual factors influence the likelihood of reoccurrence of IRAS. © 2007 Wiley‐Liss, Inc.