Abstract 4371987: Fenestrated Endovascular Aneurysm Repair (FEVAR) versus Chimney Endovascular Aneurysm Repair (Ch-EVAR) vs Open Surgical Repair for the Treatment of Abdominal Aortic Aneurysm (AAA): A Systematic Review and Network Meta-Analysis of In

Introduction: Abdominal aortic aneurysms (AAA) come with significant treatment challenges. While open surgical repair (OSR) has been the traditional approach, fenestrated endovascular repair (FEVAR) and chimney endovascular repair (ch-EVAR) have emerged as less invasive alternatives. However, comprehensive comparisons of their outcomes remain limited. This network meta-analysis (NMA) evaluates mortality, renal complications, myocardial infarction (MI), and reintervention rates (RR) among these three approaches. Research Question: What are the comparative outcomes of FEVAR, ch-EVAR, and OSR in terms of intra-hospital mortality, intra-hospital acute renal failure (ARF), intra-hospital MI, and RR for patients with AAA? Methodology: We conducted a Bayesian NMA using a random-effects model, synthesising data from 13 studies (n=4,773 patients). The analysis included direct and indirect comparisons between RAS, CS, and MIP. Primary outcomes were 30-day mortality and stroke, with secondary outcomes of ARF and LOS. We calculated odds ratios (OR) with 95% credible intervals (CrI) and ranked treatments using surface under the cumulative ranking curve (SUCRA) probabilities. Multi-criteria decision analysis (MCDA) was used to rank interventions on the basis of all outcomes. Results: Our NMA included 13 studies involving 4,773 patients. FEVAR demonstrated superior outcomes for both intra-hospital mortality and renal failure, showing a 48% reduction in mortality risk compared to OSR (OR 0.52, 95% CrI 0.31-0.87) and a 59% lower risk of renal complications (OR 0.41, 95% CrI 0.25-0.67) (SUCRA=82.4% for mortality, 88.7% for renal outcomes). ch-EVAR showed intermediate results for these endpoints, with a 37% mortality reduction versus OSR (OR 0.63, 95% CrI 0.25-1.60). Myocardial infarction evaluation showed (FEVAR vs OSR OR 0.68, 95% CrI 0.32-1.45), though point estimates favoured endovascular approaches. Conclusion: This NMA demonstrates that FEVAR offers the most favourable perioperative safety profile for complex aortic aneurysms, with significantly lower mortality and renal complications compared to OSR. However, OSR maintains an advantage in durability with lower reintervention rates. ch-EVAR presents an intermediate option when FEVAR is not feasible. These findings support an individualised approach based on patient risk factors and anatomical considerations. Keywords:. Fenestrated endovascular repair; Chimney endovascular repair; Open surgical repair; Abdominal Aortic Aneurysm