Is intervention better than surveillance in patients with type 2 endoleak post-endovascular abdominal aortic aneurysm repair?

A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether, in patients with persistent type 2 endoleak (T2EL) post-endovascular abdominal aortic aneurysm repair (EVAR), intervention is associated with better outcomes than observation. Four hundred and eighty-three papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In a recently published systematic review including 21 744 patients who underwent EVAR, 35.4% of T2ELs resolved spontaneously, 28.5% of secondary interventions were unsuccessful and rupture occurred in only 0.9% of patients with isolated T2EL. Spontaneous sealing in 62-75% of T2ELs were reported by two included studies. A failure rate of 80% associated with transarterial embolization in aggressive treatment of any T2EL was reported by one study. Conversely, another study reported a clinical success rate of 80% associated with the transarterial approach. One study reported that of patients who underwent embolization of a persistent T2EL, 37.9% continued to experience sac growth and 20% had recurrent endoleak at 5 years. One study demonstrated that the transealing procedure for T2EL had a technical success rate of 94.1%. We conclude that the available evidence with regard to management of persistent T2EL is mainly based on retrospective case series. Conflicting results from heterogeneous studies, however, failed to support an optimal threshold for intervention. Considering the reported relatively benign natural course of most T2ELs and the fact that most T2ELs seal spontaneously, conservative management of persistent T2EL in the absence of sac expansion might be appropriate. Where intervention is indicated, imaging should exclude occult type I and III leaks as similar to 25% are not simple T2EL. Translumbar embolization of T2EL is associated with higher success rates than transarterial. Following a successful intervention, continued long-term surveillance is necessary due to the high risk (25-80%) of recurrence. The current evidence indicates that aneurysmal rupture due to an isolated T2EL is rare. Long-term prospective studies may provide better evidence to define the optimal threshold for intervention.