Comparative analysis of risk profile and treatment outcomes in patients with thoracoabdominal aortic aneurysm: Chronic dissection vs. degenerative disease

Abstract OBJECTIVES This study aimed to compare operative outcomes between patients undergoing thoraco-abdominal aortic aneurysm (TAAA) repair for degenerative disease and chronic dissected aneurysm. METHODS A retrospective analysis was conducted on consecutive patients who underwent elective TAAA repair for chronic dissection or degenerative disease between 1997 and 2025. The primary outcome measure was operative mortality, while secondary outcomes included major adverse events (MAE). Factors associated with mortality or MAE were identified using multivariable analysis. RESULTS A total of 734 patients underwent open TAAA repair, with 339(46%) having atherosclerotic disease and 395(54%) having chronic dissection. The degenerative disease group was characterized by older age (71.2 ± 10.2vs.58.9 ± 13.7, p < 0.001), higher comorbidity burden (such as ischaemic heart disease, pulmonary disease, diabetes, and renal impairment), and lower rates of connective tissue disorders (2.4%vs.26.1%, p < 0.001), and Extent I or II TAAA (57.5% vs.84.3%, p < 0.001). The overall operative mortality rate for the entire cohort was 5.9% and was higher in the chronic dissection group [OR2.54 (1.15–5.69), p = 0.022]. Incidence of paraplegia (either immediate or delayed) was higher in the degenerative group (2.8%vs.0.8%,p = 0.028). Both groups had similar risk of MAE [OR1.49 (0.90–2.45),p = 0.119]. Factors that were associated with MAE included older age [OR1.02(1.00–1.04),p = 0.050], preoperative renal impairment [OR1.83(1.17–2.85),p = 0.007], Extent I or II TAAA [OR 1.76(1.17–2.65),p = 0.007], and lower preoperative FEV1 [OR0.97(0.95–0.99),p = 0.001]. CONCLUSIONS Chronic dissection etiology was associated with higher adjusted operative mortality following open TAAA repair, likely reflecting greater anatomical complexity, with similar risk of major adverse events.