Natural History, Diagnosis, and Management of Type II Endoleaks after Endovascular Aortic Repair: Review and Update.

Endoleaks (ELs), defined as continued perfusion of the aneurysm sac despite stent-graft deployment, are the most common adverse event after endovascular aortic repair (EVAR) and account for most of the reinterventions. Type 2 EL (T2EL), caused by backflow of collateral arteries into the aneurysm sac, are the most frequently encountered and may account for the need for secondary interventions after EVAR in up to 40% of the cases. Contrast-enhanced ultrasound and magnetic resonance imaging may be better able to quantify and characterize low-flow T2EL as compared with computed tomography angiography. Support for conservative management of T2EL derives from the relatively high percentage of T2EL that will resolve spontaneously over a variable period (more than 30%) and the estimated low risk of post-EVAR rupture secondary to isolated T2EL (less than 1%). Current guidelines are that a conservative approach is appropriate for isolated T2EL without sac expansion while intervention is recommended when sac enlargement of ≥10 mm as compared with pre-EVAR is detected. Although generally safe, secondary interventions for T2EL are often unsatisfactory since persistence and recurrence are commonly encountered problems and long-term follow-up is mandatory. Further investigation is required to determine the factors associated with abdominal aortic aneurysm progression in the presence of isolated T2EL and the most cost-effective technique to manage this complication.