Four-Year Experience With the ALTO Stent Graft in Abdominal Aortic Aneurysms With Hostile Features

Low-profile stent grafts with polymer ring sealing technology expanded the use of endovascular aortic repair (EVAR) to include short conical necks and small access vessels in general. We examined the use of the ALTO stent graft (Endologix LLC, Irvine, CA) in our regional vascular centre to assess its real-life performance in cases deemed not suitable for standard stenting. This was an independent, single-centre study with no financial or material involvement from the device manufacturer.

This was a retrospective observational review of all consecutive patients treated with the ALTO stent graft between May 2020 and June 2024. Patient demographics, anatomical and radiological features, re-interventions, and general follow-up data were collected. Primary endpoints included long-term survival and freedom from Type Ia endoleak. Secondary outcomes included sac expansion and reinterventions.  Results: Forty-nine patients were included, of whom 71.4% were not fit for open repair. Median follow-up was 48 months. Half of the patients had a flared/conical neck, 20% had significant neck thrombus, and 30% had a small aortic bifurcation or small iliac vessels. The median length of the conical/flared neck was 10.5 mm (4-48 mm). Median maximal aortic neck diameter was 25.5 mm (19.5-31 mm). Median iliac artery diameter was 6.5 mm (4-9 mm). The technical success rate was 98%, with only one patient converted to open. One patient died within 30 days after discharge from chronic obstructive pulmonary disease (COPD)/COVID. Freedom from reintervention at 12, 24, 36, and 48 months was 100%, 100%, 100%, and 85.71%, respectively. One patient developed a Type III endoleak after four years. We observed no aneurysm-related mortality.  Conclusion: The ALTO stent-graft system demonstrates an effective and durable seal in abdominal aortic aneurysm (AAA) cases with hostile features, with outcomes comparable to standard EVAR, expanding the options for patients less fit for open repair.