Natural History of Late Type IA Endoleaks

Abstract

Although early type IA endoleaks are well described, late-appearing proximal endoleaks are less understood. All patients who underwent elective endovascular aneurysm repair without prior aortic surgery at a single institution from 2010 to 2018 were studied. Only type IA endoleaks diagnosed on postoperative computed tomography scans were considered, not completion angiograms. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late type IA endoleaks. There were 477 patients who underwent endovascular aneurysm repair, of whom 411 (86%) had adequate follow-up. There were 24 type IA endoleaks, 4 early and 20 late. The freedom from type IA endoleaks was 99%, 92%, and 81% at 1 year, 5 years, and 8 years, with a median time to occurrence of 2.5 years (3 days-8.2 years). Only 40% of patients with type IA endoleaks were treated within the initial graft instructions for use. Although 75% of the early type IA endoleaks appeared on completion angiography, only 10% of patients with a late type IA endoleak had a proximal endoleak on completion angiography, and 60% had no endoleak at the completion of the index case. Only 21% of late type IA endoleaks were evident by 1 year, but 79% had stable or expanding sacs. Twelve (60%) late type IA endoleaks had prior interventions for other endoleaks, mostly type II (10/12). Age (hazard ratio [HR], 1.07 per year [1.02-1.12]; P = .01), neck diameter >28 mm (HR, 3.5 [1.2-10.3]; P = .02), neck length <20 mm (HR, 3.0 [1.1-8.6]; P = .04), and neck angle >60 degrees (HR, 3.4 [1.5-7.9]; P = .004) were all independently associated with higher rates of type IA endoleak, but not female sex, endograft, or the use of suprarenal fixation. Two patients had proximal degeneration and five experienced graft migration. There were two ruptures (10%), and 14 patients underwent repair (5 open, 9 endovascular), 3 of whom underwent multiple interventions. Median survival after late type IA endoleak repair was 6.6 years (0-8.4 years). Late-appearing type IA endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful follow-up is needed, especially in patients with hostile neck anatomy and those undergoing intervention for other endoleaks.