Failed AAA endograft exclusion due to type II endoleak: explant analysis

To report the patient history and analysis of an explanted modular bifurcated endograft that was implanted to exclude an abdominal aortic aneurysm (AAA).

An 80-year-old man with a 6-cm AAA underwent uneventful endovascular implantation of a bifurcated AneuRx stent-graft. His postprocedural clinical course was uneventful, although persistent contrast enhancement of the aneurysm remained via the inferior mesenteric artery (IMA). By 6 months, an endoleak connecting to the lumbar and mesenteric arteries became apparent. Over the ensuing 12 months, the endoleak and aneurysm enlarged; branch artery embolization was attempted in 4 percutaneous procedures. Despite successful IMA occlusion, the aneurysm continued to increase in diameter and volume, necessitating conversion to a conventional bypass at 20 months. Analysis of the explanted specimen revealed an intact endograft with fibrous incorporation of the stent framework at the proximal and distal fixation sites only; no incorporation of the endograft was noted within the aneurysm. The feeding channel for the endoleak was not identified.

Serial imaging is a vital component of endograft surveillance, and persistent type II endoleaks that cannot be completely embolized endanger the longevity of the aneurysm exclusion. Explant analysis can play an important role in understanding the mechanisms of endograft failure.