Systematic Long-term Follow Up After Endovascular Abdominal Aortic Aneurysm Repair With the Zenith Stent Graft

Although endovascular aneurysm repair (EVAR) has been widely adopted, long-term data remain limited. This study analyses the long-term outcome (16 years) after EVAR with the Zenith stent graft in a single academic centre.

From 2000 to 2010, 282 patients with an abdominal aortic aneurysm (AAA) were treated electively and monitored annually. Primary outcomes were overall and AAA rupture free survival; the secondary outcomes were complication and re-intervention free survival. Kaplan-Meier analysis was used to examine survival.

The median patient age was 76 years (range 49-92 years) and mean aneurysm diameter 61 mm (range 40-110 mm). Patients were followed for a median of 76 months (range 0-201 months). Overall survival was 93% (SE 0.02), 61% (SE 0.08), 25% (SE 0.16), and 9% (0.19) at 1, 2, 5, 10, and 16 years, respectively. Ten (3.5%) AAA ruptures occurred, and the cumulative AAA rupture free survival was 100%, 98% (SE 0.01), 96% (SE0.02), and 79% (SE 0.12) at 1, 5, 10, and 16 years, respectively. The mean annual AAA rupture rate was 0.5%. Freedom from any stent graft related complications was 68% (SE 0.03), 58% (SE 0.09), 54% (SE 0.17), and 52% (SE 0.21), respectively; freedom from graft related re-interventions was 95% (SE 0.01), 80% (SE 0.08), 73% (SE 0.11), 70% (SE 0.16), at 1, 5, 10, and 16 years, respectively. Five (1.8%) late conversions were required during follow up. The variables that significantly and independently correlated with ruptured AAA were pre-operative aneurysm size and primary type II endoleak. The latter was the only independent significant factor to increase the risk of re-intervention.

The number of graft related complications is high after EVAR, and new complications keep appearing years after the initial procedure. Even though fatal AAA rupture after EVAR is rare, it cannot be totally avoided despite systematic follow up.