What is an endoleak in relation to graft complications?

An endoleak refers to a situation where there is blood flow outside the lumen of a vascular graft but still contained within the aneurysm sac. This condition is problematic because it indicates that there is a failure of the graft to completely seal the aneurysm. The presence of an endoleak can compromise the long-term success of the graft, leading to potential complications such as aneurysm expansion or rupture.

In essence, endoleaks signify that while the graft itself may remain patent, there are areas where blood is not being appropriately diverted away from the aneurysm sac. This can occur through several mechanisms, such as a gap between the graft and the vessel wall, or through fenestrations in the graft.

Understanding endoleaks is crucial in the context of post-operative monitoring of patients who have undergone endovascular aneurysm repair (EVAR), as these leaks can lead to severe outcomes if not addressed.