Aneurysm Repair with Endovascular Aneurysm Sealing: Technique, Patient Selection, and Management of Complications.

Endovascular aneurysm sealing (EVAS) is conceptually different than endovascular aneurysm repair (EVAR). Unlike EVAR which seals in healthy tissue at the proximal and distal attachment sites without direct treatment of the aneurysm sac, EVAS uses polymer to fill and actively treat the entire aneurysm. This "active sac management" addresses some of the limitations of the current EVAR devices including prevention of type II endoleak and low rates of sac expansion and rupture. The Nellix System is the only commercially available EVAS platform and has been available in Europe and New Zealand since 2013. Early outcomes with the Nellix System were encouraging and demonstrated high procedural and technical success with very low morbidity and mortality as well as low endoleak and secondary intervention rates. Two-year results have maintained a high freedom from overall endoleak and rupture, but 2-year imaging identified a low incidence of late complications-device migration, type 1A endoleak, and aneurysm sac expansion. In response, a field safety notification was issued by the manufacturer (Endologix, Inc, Irvine, CA) in October 2016. A dedicated root cause analysis resulted in refinements to the Instructions for Use. The EVAS procedure continues to evolve and improve. There have been alterations to procedural technique, device modification, and patient selection. Optimum management strategies for complications have also been developed. The focus of this article is to highlight the updates to the Nellix Instructions for Use for both patient selection and procedural techniques along with the associated clinical benefits as well as describe the management of migration, sac expansion, and type 1A endoleak.