BACKGROUND: Despite the remarkable outcome of open thoracoabdominal aortic repairs of high-volume aortic centers, generalized result that spans diverse clinical settings are needed in the era of thoracic endovascular aortic repair (TEVAR). This study explored the national real-world data focusing on the impact of cumulative surgical volume on the operative outcomes. METHODS: Using data from the Korean National Health Insurance Service claims database, the cohort included adult patients who underwent open thoracoabdominal or descending thoracic aortic aneurysm repairs from 2008 to 2020. The primary outcome was operative mortality defined as 30-day mortality or in-hospital mortality. The secondary outcome was adverse early outcome defined as a composite measure of operative mortality, stroke, and spinal cord injury. RESULTS: A total of 2,514 patients (mean age, 60.7 years
615 (24.5%) female) were included in the study. Distribution of cases revealed a pronounced bias towards a limited number of larger centers: 1,724 surgeries (68.6%) were concentrated in 6 highest-volume centers. Operative mortality rates decreased with increasing surgical volume: 30.1% in institutions with <
50 cases, 20.6% for 50-99, 15.0% for 100-299, and 10.5% for those with ≥300 cases (P<
0.002). Multivariable analyses further revealed that higher hospital volume was associated with lower risks of operative mortality and adverse early outcomes. CONCLUSIONS: The early operative outcomes of open thoracoabdominal aortic aneurysm repairs were significantly influenced by the institutional volume of the operating centers, highlighting the indispensable role of experience and expertise. This suggests the strategic aggregation of cases towards specialized, high-volume centers to optimize surgical results.