Early Experience with Ovation Alto Stent-Graft

Background: Alto is the latest generation of the Ovation stent-graft platform for endovascular aneurysm repair (EVAR). Its ultra-low profile and its proximal sealing zone close to the lowest renal artery (≥7 mm) increase standard EVAR eligibility. We report early clinical and technical outcomes with the Alto stent-graft in our University Hospital Center after CE Mark approval in August 2020.

Methods: Seven patients (all male, mean age 76.1 ± 6.2 years) underwent EVAR with Ovation Alto stent-graft between June 2021 and February 2022. All the EVAR procedures were performed by a team of vascular surgeons experienced on EVAR with previous generation of Ovation platform. Follow-up consisted of duplex ultrasound examination at 1, 3, and 6 months and of a 1-month control computed tomography angiography (CTA). Patients treated gave consent to participate in this case series and publication. A descriptive analysis of variables was performed. SPSS (version 25) and Excel were used for statistical analysis.

Results: Most of the patients had a fusiform abdominal aortic aneurysm (n = 5; 71.4%). The median maximal transversal aortic diameter was 5.06 cm (range, 3.98-6.99). Because of hostile aortic neck anatomy, on-label EVAR was considered feasible only with Ovation Alto stent-graft. Narrow iliac arteries (<6 mm) were also present in 2 cases. All procedures were performed according to the instruction for the use of the device. Technical success was achieved in all cases. No type IA/IB/III endoleak occurred at completion angiography. No distal migration (>10 mm) but 2 distal displacements (≥2 mm) were observed at control CTA. During follow-up, duplex ultrasound and CTA showed no type I/III endoleak, no stent-graft migration (>10 mm), and no proximal aortic neck variations (P = not statistically significant). Three patients (42.8%) are under strict surveillance because of low-flow type II endoleak not associated with sac variations.

Conclusions: Our early experience shows promising technical and clinical success with Alto stent-graft. The proximal relocation of the proximal sealing rings and the ultra-low profile delivery system allow on-label EVAR in a wider range of aortic anatomies. Notwithstanding, further studies, meta-analysis, and prospective registries are mandatory to evaluate mid- and long-term efficacy and safety of this latest Ovation platform.