Endoleaks: Types and Causes | Tampa General Hospital


An endoleak is a complication of endovascular aneurysm repair (EVAR) surgery, which involves inserting a stent to support parts of the aorta that were weakened by an aortic aneurysm. Ideally, the stent should serve as a new pathway for blood to flow through. With an endoleak, however, some amount of blood continues to leak into the aneurysm sac.

Causes of Endoleaks

There are five types of endoleaks, all of which have different causes:

  • Type I – These are leaks that develop at either end of the stent graft or where the components overlap due to an insufficient seal.
  • Type II – These leaks occur when blood flows from branches of the aorta into the aneurysm sac.
  • Type III – These are leaks that result from some type of defect in the stent graft (for example, a hole in the fabric or a separation between the components).
  • Type IV – This type occurs when blood leaks through the pores of the stent graft.
  • Type V – Also known as endotension, this is not a leak but rather the continued enlargement of the aneurysm sac when there is no evidence of a leak.

Symptoms of Endoleaks

Endoleaks typically don’t cause any noticeable symptoms. However, if the leaking blood causes the aneurysm sac to expand to the point where it ruptures, it can become a life-threatening emergency.

Diagnosing Endoleaks

Certain types of endoleaks can be seen on the angiogram that’s typically performed at the end of EVAR surgery. In order to catch any leaks that may develop at a future time, patients generally have to undergo imaging tests—which might consist of computed tomography (CT) scans, magnetic resonance imaging (MRI) scans or ultrasounds—on a regular basis for the rest of their lives. Because endoleaks can occur years after EVAR surgery, it’s important to follow instructions for long-term follow-up monitoring and care.

Treatment for Endoleaks

Treatment for endoleaks will vary depending on the type of leak present and the size of the aneurysm sac. For example, while Type II endoleaks often resolve on their own, Type I endoleaks generally require immediate treatment. The specialists at Tampa General Hospital assess endoleaks on a case-by-case basis and provide patients with highly individualized treatment recommendations.