A Narrative Review of Competing Risks and Real-World Elective Abdominal Aortic Aneurysm Repair Mortality

AbstractObjective To synthesize current evidence on competing-risk analyses of abdominal aortic aneurysm (AAA) natural history, the real-world operative mortality after elective open aortic repair (OAR) and endovascular aneurysm repair (EVAR), and the influence of surgical volume, geographic region, and rurality on perioperative outcomes. Methods A narrative review was conducted using PubMed through March 2025, supplemented by manual review of reference lists from key studies and clinical practice guidelines. Studies were included if they reported competing-risk analyses of AAA rupture, perioperative or in-hospital mortality after elective OAR or EVAR with region-specific data, or associations between surgical volume, institutional factors, or rurality and AAA repair outcomes. Results Only two studies have applied competing-risk methodology to AAA natural history, both reporting substantially lower rupture risk than historical estimates, including annual rupture rates below 2% for aneurysms measuring 5.5–6.0 cm. Real-world perioperative mortality varies widely across healthcare systems, ranging from 0.8% to 18.6% for OAR and from 0.2% to 3.4% for EVAR, frequently exceeding rates reported in the randomized trials that inform current guidelines. Volume–outcome relationships are more pronounced for OAR than EVAR and appear mediated not only by procedural volume but also by institutional capacity to manage adverse events. Limited data suggest that rurality does not adversely affect perioperative outcomes after elective AAA repair, likely reflecting referral to specialized centers. Representation from low- and middle-income countries remains scarce. Conclusion Evidence on competing-risk methodology applied to AAA natural history is scarce, but existing studies suggest lower rupture risk than historically estimated. Real-world AAA repair mortality is highly variable across healthcare systems, raising the possibility that current diameter-based thresholds may overestimate rupture risk and underestimate operative mortality in certain settings. Future decision-support tools integrating competing-risk estimates, competing mortality, and locally benchmarked operative outcomes may improve individualized decision-making.