Outcomes and computational analysis of visceral branches in thoracoabdominal aortic aneurysm endovascular repair: a single-center study

To report the clinical outcomes of endovascular repair for thoracoabdominal aortic aneurysms (TAAA) and to investigate the hemodynamic mechanisms underlying post-operative visceral artery complications using computational fluid dynamics (CFD). A retrospective analysis was conducted on 40 consecutive patients underwent TAAA endovascular repair between 2015 and 2023. Given the lack of access to commercial branched devices, a range of techniques were employedincluding fenestrated (f-EVAR), chimney (ch-EVAR), and physician-modified multibranch endografts. Patient demographics, operative details, and outcomes were collected. For four patients who developed renal artery stenosis or occlusion, patient-specific CFD models were constructed to analyze hemodynamic parameters. The cohort was predominantly male (80.0%) with a mean age of 58.0 ± 17.5 years. Primary technical success was 92.5%. The 30-day mortality rate was 2.5% with a 30-day complication rate of 32.5%. Multivariable analysis identified history of stroke (OR = 51.224, p = 0.007), compression symptoms (OR = 21.811, p = 0.048), and higher post-operative creatinine (OR = 1.046, p = 0.006) as independent predictors for 30-day adverse events. During a median long-term follow-up of 54 months, all-cause mortality rate was 21.1% (8/38), with an aneurysm-related mortality of 5.3% (2/38). The 1-year and 3-year, and 5-year survival rates were 89.5%, 84.0%, and 80.9%. Four patients (10%) developed renal artery stenosis/occlusion. CFD analysis revealed two distinct hemodynamic phenotypes: one associated with abnormally high time-averaged wall shear stress (TAWSS) and the other with low TAWSS at the site of complication. Patient-specific endovascular repair of TAAA is feasible and associated with acceptable long-term outcomes. The occurrence of visceral artery complications may be driven by divergent hemodynamic profiles.