Abdominal Aortic Endografting Beyond the Trials: A 15-Year Single-Center Experience Comparing Newer to Older Generation Stent-Grafts

Purpose: To evaluate the late results of endovascular aneurysm repair (EVAR) with the endografts currently in use and compare outcomes to older devices. Methods: Clinical, demographic, and imaging data on consecutive patients undergoing elective EVAR from January 1997 to December 2011 at a single center were retrieved from an electronic database and reviewed. Newer stent-grafts (NSG) were defined as those introduced after 2004 (second-generation Excluder and Anaconda) or currently in use without modifications (Zenith, Endurant). Of the 1412 consecutive patients (1290 men; mean age 73 years) who underwent elective EVAR in a tertiary university hospital, 882 were treated with NSGs and 530 with older stent-grafts (OSGs). Results: In the NSG group, the abdominal aortic aneurysms (AAA) were larger (55.7 vs. 53.2 mm, p<0.0001) and the patients were older (p<0.0001) and less frequently smokers or had pulmonary disease, while hypertension and diabetes were more frequent (all p<0.0001). Thirty-day mortality was 0.8% in the NSG group vs. 1.1% in the OSG group (p=NS). Follow-up ranged from 1 to 174 months (mean 54.1 +/- 42.4); the OSG patients had longer mean follow-up compared to the NSG group (80.2 +/- 47.9 vs. 38.4 +/- 29.1 months, p<0.0001). All-cause survival rates were comparable in both groups. Freedom from late conversion (96.1% vs. 89.1% at 7 years, p<0.0001) or reintervention (83.6% vs. 74.2% at 7 years, p=0.015) and freedom from AAA diameter growth >5 mm (p=0.022) were higher in the NSG group. In adjusted analyses, the use of a new-generation device was a negative independent predictor of reintervention [hazard ratio (HR) 0.67, 95% confidence interval (CI) 0.49 to 0.93, p=0.015] and aneurysm growth (HR 0.63, 95% CI 0.45 to 0.89, p=0.010). Conclusion: Newer-generation endografts can perform substantially better than the older devices. In the long term, incidences of reintervention, conversion, and AAA growth are decreased in patients treated with devices currently in use. However, the need for continuous surveillance is still imperative for all endografts.