Type II endoleaks most commonly arise from which source?

Type II endoleaks are a specific type of endoleak that occur when there is continued perfusion to the exclusion sac of the aneurysm after the placement of an endovascular device. The most common sources for type II endoleaks are usually the branches of the aorta that maintain blood flow into the aneurysmal sac.

The inferior mesenteric artery (IMA) and lumbar arteries are particularly notable as they can provide blood flow that leads to a type II endoleak. The IMA supplies branches that can reach the lower segment of the aorta, and when there is retrograde flow through these vessels into an aneurysm, it can result in the formation of a type II endoleak. Lumbar arteries, which are also branches off the aorta, can similarly serve as a source of blood flow that leads to this condition.

While other sources of collateral flow exist, such as the renal arteries or aortic collaterals, they are less frequently implicated compared to the IMA and lumbar arteries. The duodenum is not associated with type II endoleaks, as it does not provide vascular supply leading to such complications. Recognizing the specific blood vessels involved in type II endoleaks is crucial for management, as