Type II endoleak and aortic aneurysm sac shrinkage after preemptive embolization of aneurysm sac side branches

Objective: Type II endoleak (T2EL) is the most common endoleak after endovascular aneurysm repair (EVAR). Its optimal management has been controversially discussed. Thus, preliminary selective embolization of aneurysm sac side branches (ASSBs) has been adopted to prevent T2EL. Our goal was to determine the rate of T2EL and the diameter decrease of abdominal aortic aneurysms (AAAs) after EVAR performed after preemptive embolization of ASSBs. Methods: From September 2014 to September 2019, 139 patients with AAAs underwent percutaneous ASSB embolization before EVAR. Follow-up imaging studies were performed at 1 and 6 months and annually thereafter. The end points included freedom from T2EL, AAA sac shrinkage, T2EL-related reinterventions, and all-cause mortality. Results: The mean follow-up was 23 +/- 16 months (range, 1-61 months). The patients had had a median of five (range, one to eight) patent ASSBs found on preoperative imaging studies. After completion of embolization, 76.4% of the initially patent ASSBs were occluded, with no major procedure-related complications. Follow-up imaging studies showed T2ELs in seven patients (5%), with an aneurysm sac increase seen in six of these patients. The number of ASSBs remaining patent after embolization was the only discriminative factor in patients with and without T2EL. Six T2EL-related reinterventions were performed during follow-up. Most patients (n = 91; 86.7%) had experienced aneurysm sac shrinkage, and the mean diameter reduction was 9.2 +/- 7.7 mm (P<.001) in all patients with follow-up data available. One aneurysm-related death occurred within 30 days after EVAR. Conclusions: Preemptive embolization of ASSBs for patients with AAAs is safe and effective in preventing T2ELs after EVAR. Aneurysm sac shrinkage was observed in a high proportion of patients.