Absence of proximal neck dilatation and graft migration after endovascular aneurysm repair with balloon-expandable stent-based endografts

Objective: Proximal neck dilatation (PND) and/or endograft migration with the subsequent development of type I endoleak is a significant cause of late endograft failure after endovascular abdominal aortic aneurysm repair (EVAR). Although there are numerous reports examining PND in patients receiving endografts that use self-expanding stents (SES) for proximal fixation, there are no such reports for patients treated with endografts that use balloon-expanding stents (BES). The purpose of this study was to investigate PND and endograft migration after EVAR with BES endografts. Methods: We retrospectively reviewed all charts and all serial computed tomographic scans available for patients who underwent EVAR with a BES endograft (surgeon-made, aortounifemoral polytetrafluoroethylene graft with a proximal Palmaz stent) between August 1997 and October 2002. Only patients with longer than a 12-month follow-up were analyzed. Neck diameter was measured at the level of the lowest renal artery and at 5 mm below it. PND was defined as neck enlargement of 2.5 mm or more. To assess endograft migration, the distance between the superior mesenteric artery and the cranial end of the BES was measured. Stent migration was defined as a change of 5 mm or more. Results: A total of 77 patients received this device during the study period. The technical success rate was 99%. The 1-, 3-, and 5-year survival was 66%, 48%, and 29.5%, respectively. Complete serial computed tomographic scans were available in 41 of the 48 patients who survived 12 months or longer after the operation. The mean follow-up period for these patients was 31 months (range, 12-66 months). The maximum aneurysm diameter was either unchanged or decreased in 35 patients (85%). The immediate postoperative proximal neck diameter was 19 to 29 mm (median, 24 mm). This was unchanged at the latest follow-up. None of the patients had significant PND. The cranial end of the BES was located in the area between 14 mm proximal and 36 mm distal to the superior mesenteric artery (median, 6 mm). None of the patients developed significant endograft migration. Conclusions: Neither PND nor endograft migration was observed with the BES endograft. The nature of the SES may be responsible for the observed neck dilatation and device migration after EVAR with SES endografts. This study suggests that BES may be a better fixation method for EVAR.