Influence of Type 2 Endoleaks on Long-Term Outcomes after Endovascular Repair for Abdominal Aortic Aneurysms: A National Hospital Organization Network Study for Abdominal Aortic Aneurysms in Japan.

ABSTRACT

BACKGROUND: Although endovascular repair (EVAR) is the first-line treatment for abdominal aortic aneurysm, type 2 endoleak (EL), which is associated with late sac enlargement or rupture, remains a concern. The present study aimed to assess the influence of type 2 EL on long-term outcomes after EVAR. METHODS: Among 550 patients who underwent EVAR between 2007 and 2013 at 14 Japanese national hospitals, 135 patients had type 2 EL diagnosed on follow-up computed tomography (CT) within 12 months after EVAR (EL2[+] group) and 415 patients did not have EL within 12 months (EL2[-] group). The cumulative incidences of sac enlargement, late intervention, and aneurysm-related death after EVAR were estimated using the cumulative incidence function method, and prognostic factors were investigated using the Fine-Gray hazard model. RESULTS: The median follow-up period was 5 years, and the 5-year cumulative incidence rates of sac enlargement, late intervention, and aneurysm-related death were 30.7% ± 4.4%, 25.3% ± 4.1%, and 2.6% ± 1.4%, respectively, in the EL2(+) group, and 8.7% ± 1.6%, 7.6% ± 1.4%, and 0.3% ± 0.3%, respectively, in the EL2(-) group. The cumulative incidence rates of sac enlargement (P = 0.002), late intervention (P < 0.001), and aneurysm-related death (P = 0.015) were significantly different between the 2 groups. As the first-line treatment for sac enlargement with type 2 EL, transcatheter coil embolization was performed in 30 patients. Information about sac behavior on CT after coil embolization was available in 20 of the 30 patients. Among these patients, no patients experienced sac shrinkage, and the aneurysmal sac dilated after coil embolization in 18 patients. CONCLUSIONS: Type 2 EL affects the long-term outcomes after EVAR. It is not recommended to observe large aneurysmal sacs conservatively as they tend to dilate in the presence of type 2 EL.