Medium and Long Term Time to Event Outcomes after Elective Fenestrated and 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 branched endovascular aortic repair for complex abdominal and thoraco-abdominal aneurysms and to assess the certainty of the available evidence. 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 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 mortality 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 mortality and re-intervention, and very low for target vessel patency. CONCLUSION: Elective fenestrated and branched endovascular aortic repair provides durable aneurysm exclusion with low aneurysm related mortality. 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.