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

Cardiovasc Intervent Radiol. 2025 Apr;48(4):438-446. doi: 10.1007/s00270-025-03996-x. Epub 2025 Mar 17.

Abstract

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.

Keywords: abdominal aortic aneurysms; endovascular aneurysm repair; proximal neck dilatation.

Publication types

  • Multicenter Study
  • Observational Study
  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aortic Aneurysm, Abdominal* / diagnostic imaging
  • Aortic Aneurysm, Abdominal* / surgery
  • Blood Vessel Prosthesis Implantation* / methods
  • Blood Vessel Prosthesis*
  • Dilatation, Pathologic
  • Endovascular Aneurysm Repair
  • Endovascular Procedures* / methods
  • Female
  • Humans
  • Japan
  • Male
  • Postoperative Complications*
  • Prosthesis Design
  • Retrospective Studies
  • Stents*
  • Treatment Outcome