Long-term Survival After Endovascular Repair for Intact Infrarenal Abdominal Aortic Aneurysms is Improving Over Time

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Introduction: There is a growing body of literature raising concerns over the long-term durability of endovascular repair (EVAR) for abdominal aortic aneurysms (AAA) and suggesting that long-term outcomes may be better after open AAA repair. However, the data investigating these long-term outcomes largely originate from early in the endovascular era and therefore do not account for increasing clinical experience and technological improvements. Therefore, we investigated whether long-term outcomes after EVAR and open repair have improved over time. Methods: We identified all EVARs and open repairs for intact infrarenal AAA within an international vascular clinical database (2003-2018). We then stratified patients by procedure year into treatment cohorts of four years: 2003-2006, 2007-2010, 2011-2014, and 2015-2018. We used Kaplan-Meier analysis and Cox proportional hazards models to assess whether there was an improvement in EVAR or open repair over time. Additionally, we matched EVAR and open repairs for each time cohort, to investigate whether the relative survival benefit of EVAR over open repair changed over time. Results: We included 40,811 EVARs (increasing from 549 performed between 2003-2006 to 24,059 between 2015-2018) and 9,241 open AAA repairs (increasing from 739 performed between 2003-2006 to 4,273 between 2015-2018). For both EVAR and open repair, median age decreased over time (EVAR: 75 vs. 74 vs. 74 vs. 73, P< .001; open repair: 72 vs. 70 vs. 70 vs. 70, P< .001). Four-year survival increased for the periods 2003-2006, 2007-2010, 2011-2014, and 2015-2018 as 76% vs. 80% vs. 84% vs. 88% for EVAR (P< .001) and 81% vs. 85% vs. 86% vs. 88% for open repair (P=.003; Figure 1). After risk-adjustment, compared to 2003-2006, the hazard ratio (HR) for long-term mortality after EVARs performed between 2011-2014 was 0.64 (95%CI: 0.47-0.88; P=.017) and 0.46 for those performed between 2015-2018 (95%CI: 0.34-0.64; P< .001). In contrast, the risk-adjusted mortality did not decrease for open repair cohorts over time (2007-2010: HR: 1.23 [95%CI: 0.85-1.77; P=.28]; 2011-2014: HR: 0.98 [95%CI: 0.64-1.51; P=.94]; 2015-2018: HR: 0.91 [95%CI: 0.58-1.43; P=.69]). From the early to the latest follow-up cohort, we matched 365, 431, 1,339, and 1,211 EVAR to open repair patients. Survival curves for these cohorts are displayed in Figure 2: whereas EVAR and open repair showed similar survival in the first two cohorts, EVAR patients treated between 2011-2014 showed only a survival benefit up to two years, with no difference in four-year survival (P=.15). However, EVAR patients in the latest cohort experienced a higher survival over the full time period (P=.02).Figure 2Four-year Survival for Matched EVAR and Open Repair Procedures per Treatment Cohort.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Conclusion: Long-term outcomes following EVAR are still improving over time, but not following open repair. Consequently, we found a trend towards higher relative survival rates after EVAR compared to open repair over time. These finding suggests that long-term durability following EVAR may be improving with new generations of endografts and increased experience, information that should be considered by surgeons and policymakers when evaluating the long-term value of contemporary EVAR to open AAA repair. Disclosure: HV is a consultant for Medtronic, WL Gore, Endologix, Abbott, Arsenal AAA MS is a consultant for Abbott Vascular, Cook Medical, Endologix, Medtronic, and Silk Road