Endoleak after endovascular aortic repair: classification, diagnosis and management following endovascular thoracic and abdominal aortic repair.

Endoleak is a common and unique complication of endovascular aortic repair (EVAR) and its persistence represents a failure of the endovascular treatment. Accurate detection and classification is essential for the proper management since the method of endoleak treatment is determined by the different source. In general, high-pressure leaks (type I and type III) require urgent management because of the relatively high short-term risk of sac rupture. Although precise differentiation between type I and type III endoleaks may not be possible at cross- sectional imaging, differentiation is often unnecessary because both lesions are considered high-risk and require angiographic evaluation and subsequent treatment. Low-pressure lesions (types II and V or endotension) are considered less urgent but may warrant continued endovascular evaluation if there is impending growth of the aneurysm sac or if the patient presents with symptoms. Once detected, endoleaks warranting correction (all type I and III; persistent endotension and type II associated with aneurysm enlargement) are usually treated by endovascular route. A variety of techniques including extension endografts or cuff, balloon angioplasty, bare stents and a combination of transvascular and direct sac puncture embolization techniques has allowed to treat the vast majority of these endoleaks without conversion to open surgical repair. Type II endoleak continues to be the most common but also the most controversial in terms of evaluation, the need of treatment, and methods of treatment. Careful and rigorous postoperative lifelong follow-up with computed tomography (CT) and high quality imaging continue to be essential for all patients after EVAR.