Less Aortic Neck Dilatation of the ALTO Stent Graft compared to the Self-Expanding Stent Grafts after Endovascular Aortic Repair for Abdominal Aortic Aneurysms.

PURPOSE: Proximal neck dilatation (PND) is a common issue after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs), being a potential cause of stent graft migration or type Ia endoleak. The ALTO stent graft, featuring a unique polymer sealing mechanism, has been reported to exhibit less PND. This study aims to compare PND and clinical outcomes between the ALTO stent graft and alternative self-expanding stent grafts.

METHODS

The CustomSEAL study is a multi-center retrospective observational study involving 18 institutions in Japan. It compares EVAR outcomes using the ALTO stent graft and alternative self-expanding stent grafts for fusiform AAAs. The primary outcome measure was the difference in PND at 12 months post-EVAR. Secondary outcome measures included aneurysm sac diameter changes, reintervention rates, and mortality outcomes during the follow-up.

RESULTS

After propensity score matching, 111 patient pairs were extracted. Baseline characteristics, including proximal neck length/diameter and stent graft oversizing, were comparable between groups. The ALTO stent graft was associated with significantly less PND at 12 months (2.3% vs. 26.7%, P < 0.001). There were no significant differences in perioperative outcomes, aneurysm sac diameter changes, reintervention rates, or overall survival between the groups.

CONCLUSIONS

The ALTO stent graft demonstrated significantly less PND at 12 months post-EVAR compared to alternative self-expanding stent grafts, highlighting its potential advantage in exerting less chronic expanding force on the proximal aortic neck. Long-term follow-up is needed to validate the clinical benefits of the ALTO stent graft over the alternative self-expanding stent grafts.

LEVEL OF EVIDENCE: Non-randomized controlled cohort/follow-up study.