Medium and Long Term Time to Event Outcomes after Elective Fenestrated and or Branched Endovascular Repair of Complex Abdominal and Thoraco-abdominal Aortic Aneurysms: A Systematic Review and Meta-analysis

OBJECTIVE: To define contemporary medium (3 - 5 years) and long term (> 5 years) survival and durability outcomes after elective fenestrated and or branched endovascular aortic repair for complex abdominal and thoraco-abdominal aneurysms and to assess the certainty of the available evidence. DATA SOURCES: MEDLINE, Embase, and Cochrane Library. REVIEW METHODS: MEDLINE, Embase, and the Cochrane Library were searched from January 2000 to February 2026, supplemented by citation screening. Published Kaplan-Meier time to event data were digitised and reconstructed into individual patient datasets. Pooled survival probabilities were generated using validated methods for meta-analytic methods for survival curves. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework, and risk of bias was assessed with Risk of Bias in Non-Randomised Studies - of Interventions (ROBINS-1) (v2). The protocol was registered in the International Prospective Register of Systematic Reviews (CRD42024565664). RESULTS: Twenty four studies comprising 8 886 patients were included. Pooled overall survival was 91.3% (95% confidence interval [CI] 90.7 - 91.9) at 1 year, 73.0% (95% CI 71.9 - 74.0) at 3 years, and 55.4% (95% CI 53.9 - 56.8) at 5 years. Estimated median overall survival was 6.36 years. Based on studies that reported this, at 5 years, freedom from aneurysm related death was 96.4% (95% CI 95.3 - 97.2), and freedom from re-intervention was 66.5% (95% CI 64.6 - 68.2). Target vessel patency, based on two studies, was 94.8% (95% CI 93.3 - 96.0). Certainty of evidence was low for overall survival, freedom from aneurysm related death and re-intervention, and very low for target vessel patency. CONCLUSION: Elective fenestrated and or branched endovascular aortic repair provides durable aneurysm exclusion with a low aneurysm related mortality rate. However, survival beyond 5 years declines substantially. There is a need for more robust survival data and improved tools to support patient selection, shared decision making, and assessment of anticipated benefit when considering prophylactic complex endovascular repair.