Five-Year Outcomes of Endovascular Aneurysm Repair (EVAR) Performed Using a Polymer-Based Aortic Endograft System.

Abstract

Background Endovascular aneurysm repair (EVAR) is a widely used, minimally invasive alternative management option to open surgical repair for infrarenal abdominal aortic aneurysms (infrarenal AAAs). However, standard stent grafts have their challenges for complex aortic anatomies. The Ovation Abdominal Stent Graft System (Endologix Inc., Santa Rosa, CA), which is a polymer-filled sealing ring endograft, has emerged as a promising solution for patients with challenging anatomical features. This study aims to evaluate the Technical success, effectiveness, and long-term outcomes, including reintervention and survival, of the Ovation system in treating complex infrarenal AAAs. Methods We conducted a single-centre, retrospective observational study of 103 patients with anatomically challenging infrarenal AAAs treated with the Ovation stent graft between January 2015 and November 2017 in a UK-based tertiary centre. Anatomical parameters included short necks, severe angulation (>60°), significant thrombus or calcification (>180 degree of the wall diameter), non-cylindrical neck shapes, or an iliac access diameter <6 mm. Outcomes assessed included technical procedural success, Endoleak incidence, Conversion to open, reintervention rates, 30-day aneurysm-related mortality, and all-cause mortality over a 5-year follow-up. Results A total of 103 patients underwent EVAR using the Ovation stent graft between January 2015 and November 2017, with a 5-year follow-up. All patients had at least one adverse anatomical feature, including short necks, significant thrombus or calcification, severe neck angulation, or narrow iliac access. The cohort was predominantly male, comprising 80 patients (77.7%) with a mean age of 76.4 years (SD = 6.67). Technical success was achieved in 97% of cases, with Type I endoleak observed intraoperatively in 3 patients (2.9%). Intraoperative complications occurred in 4.8% of patients, with no aneurysm rupture or conversions to open surgery. The 30-day aneurysm-related mortality was 0%, and the overall reintervention rate over five years was 9.7%. The five-year all-cause mortality rate was 16.5%. Conclusions The Ovation polymer-based endograft demonstrates excellent technical success and favourable long-term outcomes in patients with infrarenal AAA with unfavourable anatomy, including low rates of type I endoleaks, reintervention, and aneurysm-related mortality. These findings support its use as a durable and effective EVAR solution in anatomically challenging cases beyond the standard IFU. Further multicentre prospective studies are warranted to confirm these promising results.