Endovascular Treatment of Type II Endoleaks: Update and Overview

Abstract

Endoleaks are a common complication following endovascular aneurysm repair, despite EVAR being the preferred method for the repair of abdominal aortic aneurysms. Endoleaks are continued blood flow into the aneurysmal sac, or more broadly elevated pressure outside of the endograft, and are classified into five types based on the source of blood flow or elevated pressure. Type II endoleaks are the most common and are a result of retrograde flow to the sac most commonly from the inferior mesenteric artery or lumbar artery. Endovascular treatment options for type II endoleaks include transarterial, transcaval, translumbar, and transabdominal approaches. This review discusses the indication for endovascular treatment of type II endoleaks, the selection of approach, and technical considerations.

Keywords: aneurysm; embolization; endograft; endoleak; interventional radiology.

Fig. 1

Endoleak types. ( a ) Sagittal CTA demonstrating perfusion to the sac posterior to the proximal portion of the aortic stent graft (arrow), consistent with a type IA endoleak. ( b ) Sagittal CTA demonstrating inadequate sealing and aneurysm sac perfusion between the proximal fenestrated stent and distal stent (arrow) consistent with a type III endoleak. ( c ) Aortography after placement of an endograft in 2013 demonstrating a type IV endoleak due to graft porosity (arrow). Examples of type II endoleaks are included below.

Fig. 2

Basic flowchart for selecting embolization approach.

Fig. 3

Patient with a history of AAA status post EVAR in March 2021. The excluded aneurysm sac (* a ) continued to grow on surveillance imaging, with an increase in size of 1.6 cm in the 3 months prior to intervention. CTA demonstrates a complex type 2 endoleak in the anterior sac, which was traced back to the IMA on ( a ) arterial (arrow) and ( b ) delayed (arrow) imaging. ( c ) A 5-Fr RC2 catheter was used to select the SMA (*), which was widely patent and demonstrated perfusion of the aneurysm sac (arrow) on angiography. ( d ) The nidus was embolized using detachable and pushable coils. The proximal IMA was then embolized using additional coils (arrow). Completion angiography (not shown) demonstrated no perfusion of the aneurysm sac.

Fig. 4

Patient with a history of AAA status post EVAR in 2018. The aneurysm sac had been enlarging, most recently up to 6.8 cm with delayed enhancement of the posterior aspect of the sac, concerning for a type 2 endoleak. ( a ) Preprocedure CTA shows filling of the posterior aspect of the sac (arrow) with close apposition of the IVC (*). ( b ) Using a transjugular liver biopsy set placed from the groin into the IVC, the aortic sac was punctured using a 21-gauge fenestration needle (arrow). ( c ) A Nitrex wire and telescoping Navicross catheters were advanced. Onyx embolization was performed (arrow).

Fig. 5

Patient with a history of AAA status post EVAR in 2010 with growing sac from 7.3 to 7.8 cm. ( a ) Preprocedure CTA demonstrated contrast filling the posterior portion of the sac (*) on delayed imaging (arrow). ( b ) The posterior aspect of the sac at the level of the previously described endoleak was punctured with a 22-gauge Chiba needle (arrow). ( c ) EVOH embolization was performed (arrow).

Fig. 6

Patient with a history of an EVAR in 2019 s/p previous L5 lumbar artery embolization in 2021 with continued sac enlargement. Presented for transabdominal endoleak embolization. ( a ) The sac was punctured through the anterior abdominal wall under ultrasound guidance (arrow). ( b ) A 22-gauge Inrad needle was used to puncture the sac and CT was performed (arrow). ( c ) Over a Nitrex wire, a 4-Fr catheter was advanced into the sac and arteriography was performed. Contrast was seen along the medial bilateral iliac endograft limbs, consistent with a type IB endoleak (arrow). Decision was made to extend the bilateral iliac limbs. ( d ) Embolization of the aortic sac was then performed with 2 vials of EVOH.