Case contributed by Dr Donna D'Souza

Contrast enhancement is seen within the aneurysmal sac but outside the EVAR, consistent with an endoleak. 

Case Discussion

An endoleak is characterized by persistent blood flow within the aneurysm sac following endovascular aneurysm repair (EVAR). Normally the aortic stent-graft used in EVAR excludes the aneurysm from the circulation by providing a conduit for blood to bypass the sac.

Endoleak is a common complication of EVAR found in up to 40% of patients. It is seen on CTA, MRA and DSA as contrast opacification of the aneurysm sac outside the graft. Flow in the sac may also be detected on ultrasound. When an endoleak occurs, flow within the aneurysm sac is at systemic or near-systemic pressure. If untreated, the aneurysm may expand and is at risk of rupture. Aneurysm expansion following EVAR always warrants investigation for endoleak.

There are several causes of endoleak which are classified into 5 types as follows:

  • type I: leak at graft attachment attachment site
  • type II: aneurysm sac filling via branch vessel (most common)
  • type III: leak through defect in graft
  • type IV: leak through graft fabric as a result of graft porosity
  • type V: continued expansion of aneurysm sac without demonstrable leak on imaging (endotension)

Types II and IV usually resolve spontaneously. Type I and III do not, and require immediate treatment. Endoleak may become evident intra-operatively, or months or years later. Therefore life-long imaging surveillance is necessary, usually performed with CTA.

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Case information

rID: 7821
Published: 15th Dec 2009
Last edited: 24th Mar 2019
System: Vascular
Inclusion in quiz mode: Included

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