Type IIIb Endoleak: A Rare Complication Identified

Purpose: The purpose of this abstract is to discuss a case of an endovascular aneurysm repair (EVAR) that upon initial postdeployment angiographic evaluation displayed an endoleak. The type of endoleak was challenging to identify because of confounding prominent lumbar arteries as well as the supposed unlikeliness of type IIIb endoleaks. This project will discuss identification and evaluation techniques.

Materials and Methods: A 73-year-old male patient underwent a planned EVAR for a nonsymptomatic abdominal aortic aneurysm (AAA) with bilateral iliac aneurysmal involvement. During this procedure, an endoleak was identified, correctly subcategorized as a rare subtype, and managed to resolution.

Results: Immediately after intragraft ballooning of the main body and bilateral limb extensions, an endoleak was identified. Contrast was identified in the AAA sac that appeared to be most prominent near the right common iliac segment. Angiography revealed multiple late-filling lumbar arteries in this area. Further confounding our evaluation, the region in question was near to the connection of the main body with the right limb extension. In a stepwise fashion using occluding balloons and various beam obliquities, more common causes of endoleak were excluded, and a type IIIb endoleak was identified. The stent graft was then relined, and the endoleak resolved.

Conclusions: Type IIIb endoleaks, although considered to be rare compared with other subtypes, do occur and must be kept in mind during EVAR deployment and evaluation. There are specific techniques that an operator can use to evaluate an EVAR and properly identify the cause of an endoleak; these techniques include the use of occluding balloons and various beam obliquities.