Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies

Objectives : Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described. Methods : We studied all elective EVAR from 2010-2018 in a single institution. Late endoleaks were defined as those appearing after one year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival. Results : Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92% and 81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine one-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P=.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P=.02), neck length 60 degrees (HR 3.4 [1.5-7.9], P=.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. Two patients had proximal degeneration and 5 experienced graft migration. There were two ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years). Conclusion : Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.