Endoleak as a predictor of outcome after endovascular aneurysm repair: AneuRx multicenter clinical trial

Objective: The purpose of this study was to determine whether evidence of b lood flow in the aneurysm sac (endoleak) is a meaningful predictor of clini cal outcome after successful endovascular aneurysm repair. Methods: We reviewed all patients in Phase II of the AneuRx Multicenter Cli nical Trial with successful stent graft implantation and predischarge contr ast computed tomographic (CT) imaging. The clinical outcome of patients wit h evidence of endoleak was compared with the outcome of patients without ev idence of endoleak. The CT endoleak status before hospital discharge at 6, 12, and 24 months was determined by each clinical center as well as by an i ndependent core laboratory. Endoleak status at 1 month was assessed with du plex scanning examination or CT at each center without confirmation by the core laboratory. Results: Centers reported endoleaks in 152 (38%) of 398 patients on predisc harge CT, whereas the core laboratory reported endoleaks in 50% of these pa tients (P < .001). The center-reported endoleak rate decreased to 13% at 1 month. Follow-up extended to 2 years (mean, 10 +/- 4 months). One patient h ad aneurysm rupture and underwent successful open repair at 14 months. This patient had a Type I endoleak at discharge but no endoleak at 1 month or a t subsequent follow-up times. There were no differences between patients wi th and patients without endoleak at discharge in the following outcome meas ures: patient survival, aneurysm rupture, surgical conversion, the need for an additional procedure for endoleak or graft patency, aneurysm enlargemen t more than 5 mm, the appearance of a new endoleak, or stent graft migratio n. Despite a higher endoleak rate identified by the core laboratory neither the endoleak rate reported by the core laboratory nor the endoleak rate re ported by the center at discharge was significantly related to subsequent o utcome measures. Patients with endoleak at 1 month were more likely to unde rgo an additional procedure for endoleak than patients without endoleaks. P atients with Type I endoleaks at discharge and patients with endoleak at 1 month were more likely to experience aneurysm enlargement at 1 year. Howeve r, there was no difference in patient survival, aneurysm rupture rate, or p rimary or secondary success rate between patients with or without endoleak. Actuarial survival of all patients undergoing endovascular aneurysm repair was 96% at 1 year and was independent of endoleak status. Primary outcome success was 92% at 12 months and 88% at 18 months. Secondary outcome succes s was 96% at 12 months and 94% at 18 months. Conclusions: The presence or absence of endoleak on CT scan before hospital discharge does not appear to predict patient survival or aneurysm rupture rate after endovascular aneurysm repair using the AneuRx stent graft. Altho ugh the identification of blood flow in the aneurysm sac after endovascular repair is a meaningful finding and may at times indicate inadequate stent graft fixation, the usefulness of endoleak as a primary indicator of proced ural success or failure is unclear. Therefore, all patients who have underg one endovascular aneurysm repair should be carefully followed up regardless of endoleak status.