Management of Nellix migration and type IA endoleak from proximal EVAS relining to late open conversion.

Abstract Background Despite promising early results, mid-term failures of the Nellix endovascular aneurysm sealing (EVAS) system have been reported at higher than expected rates. The management of proximal endoleaks and migrations differs from the conventional endovascular aortic repair (EVAR) due to the peculiar design of the Nellix device. In this study, we report a monocentric experience in the management of EVAS’ complications with various techniques. We also performed a comprehensive review of the relevant literature on both open surgical and endovascular management of proximal failures of EVAS on the MEDLINE database. Methods We retrospectively analyzed the reinterventions for type IA endoleak and migration after elective infrarenal EVAS at our institution. We collected preoperative, intraoperative and follow-up data. Open and endovascular techniques are described. Overall survival, aortic-related mortality and technical success rate (rate of exclusion of the endoleak) with endovascular techniques are the primary outcomes. Results We performed 101 infrarenal elective EVAS procedures between 2013 and 2018. The 19.8% (20/101) of patients underwent reintervention for proximal sealing failure. Indications were type IA (Is2, Is3) endoleak, migration > 5 mm, sac expansion > 5 mm or secondary rupture. Six cases (6/20, 30%) were managed with endovascular techniques: 2 chimney Nellix-in-Nellix applications (ChNiNa) and 4 proximal relinings with covered stents. The 70% (14/20) of patients were treated with late open conversion (OC). The average time from EVAS procedure to reintervention was 36.1 months (range 3-65 months). Six patients (30%) were treated with OC in an emergent setting due to secondary rupture. Technical success rate in patients treated with endovascular reinterventions was 100%. The 30-day mortality was 20% (4/20), all among emergent cases (4/6 emergent repairs, 67%). Overall survival was 75% (15/20) at a mean follow-up of 15.1 months (range 2-47 months). One patient died after 7 months for non-aortic related causes. Conclusions The high reintervention rate of this graft mandates careful evaluation for its further use with the revised IFU and it should not be used off-label. Open conversion remains the strategy of choice when dealing with Nellix proximal sealing failures in fit patients. ChNiNa and transcatheter embolization are feasible alternative techniques. Proximal relining appears to be an effective alternative to more complex interventions although it requires further studies to be validated.