The impact of large aneurysm diameter on the outcomes of thoracoabdominal aneurysm repair by fenestrated and branched endografts

Objectives: Aim of the study was to analyze the impact of preoperative thoraco-abdominal aneurysm diameter on the outcomes of fenestrated/branched endografting. Methods: Patients underwent endovascular thoraco-abdominal repair at 2 European centers (2011-2021) were analyzed. Median diameter was calculated; third quartile was considered as cut-off. Outcomes were compared in two groups based on the diameter value. Primary end-points were technical success, spinal cord ischaemia and 30-day/in-hospital mortality. Survival, freedom-from-reintervention and target-visceral-vessels instability were follow-up outcomes. Results: Out of 247 thoraco-abdominal aortic aneurysms, the median diameter was 65 mm, first quartile was 57 mm; third quartile was 80 mm, set as cut-off value. Fifty-nine(24%) patients had diameter ≥80mm. Custom-Made and off-the-shelf branched endograft were used in 160(65%) and 87(35%), respectively. Technical success was 93% (<80mm : 91% vs ≥80mm : 94%; P:0.47). Twenty-three(9%) patients had spinal injury (<80mm : 7% vs ≥80mm : 17%; P:0.03). Twenty-two(9%) patients died within 30-day/in-hospital (<80mm : 7%; vs ≥80mm : 15%; P:0.06). Multivariate analysis did not report pre-operative diameter ≥80mm as significant risk factor for primary end-points. The median follow-up was 13 (interquartile-range : 2-37) months and at 3-years survival and freedom from reintervention rates were 65% and 62%, respectively. After univariate and multivariate analysis preoperative diameter ≥80mm was considered an independent risk factor for reinterventions (HR : 1.9; 95% CI : 1.1-3.6; P:0.04), and for target visceral vessels instability (HR : 3.1; 95% CI : 1.3-5.1; P:0.04), occurred in 45(18%) cases. However after competing risk methods preoperative diameter did not show significance for follow-up results. Conclusions: A pre-operative thoraco-abdominal aortic aneurysm diameter greater than 80 mm has not a direct impact on early technical and clinical outcomes. Diameter ≥80mm is considered risk-factor for reinterventions and target-vessels instability considered separately during follow-up.