Introduction to Endoleak

Abstract

Endoleak is defined as persistent blood flow in the aneurysm sac after endovascular aneurysm repair (EVAR). Most of sac growth after EVAR could be originated from endoleak during long-term follow-up. The cause of type I endoleak may change with the period after EVAR. Endovascular treatment may be difficult for type Ia endoleak due to disease progression. Fenestrated/branched EVAR may be an alternative treatment to open conversion. Type II endoleak is not always benign. Large and late type II endoleak may lead to sac growth, and slow flow type II endoleak may be complex to treat. Treatment for type II endoleak with hostile neck aneurysm should be considered to prevent type I endoleak due to disease progression. Occult type I or III endoleak should be noted in patients with type II endoleak. The mortality is high in patients with ruptured aneurysm due to type III endoleak, while the perioperative mortality is low in patients with unruptured aneurysm with type III endoleak. Therefore, type III endoleak should be diagnosed before rupture. However, the diagnosis of type IIIb endoleak by imaging may be challenging.