ObjectivesA consensus on the management of thoracoabdominal aortic aneurysms (TAAA) in patients with Marfan syndrome (MFS) has not yet been established. This study aimed to compare the long-term outcomes after open TAAA repair in patients with and without MFS. MethodsThis retrospective study encompassed 230 consecutive patients who underwent TAAA repair between 2012 and 2022, including a comparison of 69 MFS patients and 161 non-MFS patients. The primary endpoint was long-term mortality. The secondary endpoint was early composite adverse events, including early mortality, permanent stroke, permanent paraplegia, permanent renal failure, and reoperation. Univariable and multivariable logistic regression analyses were employed to assess the impact of MFS on early composite adverse events, while univariable and multivariable Cox proportional hazards models were constructed to evaluate the association between MFS and overall mortality. ResultsCompared with non-MFS patients, MFS patients were younger (31.9±8.5 vs 44.8±12.3 years; P<0.001), with less comorbid coronary artery disease (0 vs 8.1%; P=0.034), more frequently underwent Crawford extent III repair (56.5% vs 34.8%; P=0.002) and applied normothermic iliac perfusion (91.3% vs 81.4%; P=0.057). There was no significant difference in the rate of early composite adverse events between MFS and non-MFS groups (23.2% vs 14.3%; P=0.099), which was verified by multivariable logistic regression analyses with multiple models. Overall mortality was significantly lower in MFS group compared to non-MFS group (log-rank P=0.026), with 1-, 5- and 10-year cumulative mortality of 4.4% vs 8.7%, 8.1% vs 17.2% and 20.9% vs 36.4%, respectively. Multivariable Cox regression analyses across different models further confirmed MFS as a significant protective factor for overall mortality (Model1: HR 0.31, 95%CI 0.13-0.73, P=0.007; Model2: HR 0.32, 95%CI 0.13-0.75, P=0.009; Model3: HR 0.38, 95%CI 0.15-0.95, P=0.039). ConclusionsDespite varying risk profiles, MFS patients undergoing open TAAA repair can achieve comparable or even superior outcomes to non-MFS patients under tailored surgical strategies, meticulous perioperative care, and close follow-up surveillance, especially in the long term.