Distal migration of stent-grafts after endovascular repair of abdominal aortic aneurysms

PURPOSE: To analyze patients after endovascular repair of abdominal aortic aneurysm (AAA) with respect to distal migration of stent-grafts and its und erlying causes. MATERIALS AND METHODS: Sixty-five patients underwent endovascular repair be tween January 1994 and February 1997, There were seven women and 58 men, wi th a mean age of 71 years (range, 51-84 years). Three patients died in the perioperative period (one of myocardial infarction and two of multiorgan fa ilure) and two patients died within 4 months of the procedure of non-proced ure-related causes. In addition, two patients were followed at another hosp ital. The remaining 58 patients were followed up with spiral computed tomog raphy scans at 1, 3, and 6 months, and biannually thereafter. Angiography w as performed at 1 month and 1 year after the procedure and additionally whe n deemed clinically necessary, Mean follow-up was 29 months (range, 1-49), Migration more than 5 mm was considered significant, RESULTS: Twenty-six patients (45%) showed distal migration of stent-grafts during follow-up. Mean follow-up time at detection of migration was 13 mont hs (range, 1-36 months). Thirteen cases of migration were ascribed to dilat ation of the proximal aneurysmal neck during follow-up. Ten cases of migrat ion were ascribed to causes other than neck dilatation or poor patient sele ction. In three cases, no obvious cause for the migration was found. The mi gration was complete in eight cases, leading to late conversion to open sur gical repair. On two of these occasions, complete migration lead to aneurys m rupture, In addition, four patients received additional stent-grafts as p roximal extensions, CONCLUSIONS: Distal migration of stent-grafts after endovascuIar AAA repair occurred frequently in this series, Dilatation of the proximal aneurysmal neck is a major cause of distal migration of stent-grafts, Improved proxima l fixation is needed to secure long-term durability.