Lack of durability after transarterial ethylene-vinyl alcohol copolymer-embolization of type II endoleak following endovascular abdominal aortic aneurysm repair.

Background: Type II endoleak (T2EL) after endovascular aortic repair is associated with AAA sac enlargements in up to 25%, reduction of attachment zones and rarely with aortic rupture. Indications for therapy and efficacy of interventions of T2EL are not clearly established. Transarterial embolization with application of ethylene-vinyl alcohol copolymer has been described with varying outcomes. Aim of this study is to evaluate durability of OnyxTM embolization (OE) in T2EL in a consecutive series at a single tertiary vascular center. Patients and methods: Demographic data, technical success, pre- and postoperative aneurysm growth, morbidity, mortality and reintervention rates during hospital stay as well as in follow up were recorded in patients treated with OE for T2EL between 01/2015 and 12/2017. The primary endpoint was defined as persistence or reoccurrence of T2EL (durability of OE). Results: In total 15 patients (78 ± 6 years, 13 men) were treated with OE because of sac enlargement (average growth of 12 ± 8%, n = 12), persistent bleeding after AAA rupture (n = 2) or persistent T2EL with stable but large aneurysm diameter (n = 1). Mean length of stay was 8 ± 11 days. Technical success was 93.3% (n = 14). Inhospital-morbidity was 26.7%, in-hospital- and 1-year-mortality rate were 6.6% (n = 1) and 20.0% (n = 3). T2EL persisted in 20.0% (n = 3) despite of OE. Re-EL-II occurred after 40 (30-114) days in 33.3% (n = 5). Reintervention rate was 13.3% (n = 2, at day 48 and 319). Altogether clinical success with stable aneurysm diameter was achieved in 80.0% (n = 12), but durable elimination of EL was only achieved in 46.7% of patients (n = 7). Conclusions: OE is technically possible in more than 90% of patients but might be associated with severe complications. Durability of this treatment is low, since T2EL persist or reoccur in more than 50% of all patients. OE of T2EL should be reserved for few selected cases.