Abstract: Objective To investigate the learning curve and clinical efficacy of aortic dissection and non-dissection aortic surgeries through upper hemisternotomy. Methods We retrospectively analyzed the perioperative data of aortic dissection and non-dissection surgeries through upper hemisternotomy performed by the same surgical team. Based on cardiopulmonary bypass time and aortic cross-clamping time, the learning curves were plotted using cumulative (CUSUM) analysis and the fitting curve, and the learning process was divided into the improvement period and proficiency period. We compared the perioperative parameters in the two stages, and verified whether the critical point was the number of operations required to overcome the learning curve. The safety and short-term efficacy of the aortic surgeries were analyzed after achieving proficiency. Results A total of 107 patients were analyzed, including 47 undergoing aortic dissection (ascending aorta replacement + arch replacement + descending aorta stent implantation and/or aortic root treatment) and 60 undergoing non-dissection surgeries (artery root surgery and/or ascending aorta replacement). The optimal fitting equation was y=-0.019x3+0.251x2+28.852x-6.076 (R2=0.918, P<0.05) for CPB time and y=-0.015x3-0.093x2+34.799x-27.316 (R2=0.92, P<0.05) for aortic cross-clamping time. In the dissection group, with 27 cases as the boundary, the perioperative parameters were significantly better in the proficiency stage than in the improvement stage, and the critical point was the number of surgeries needed to overcome the learning curve. The best fitting equation was y=0.013x3-1.826x2+ 62.353x + 193.189 (R2=0.906, P<0.05) for CPB time and y=0.009x3-1.416x2+49.389x+177.335 (R2=0.90, P<0.05) for aortic cross-clamping time. In the non-dissecting aorta group, where 22 cases served as the boundary, the perioperative parameters were also better in the proficiency period than in the improvement period. Conclusion Both aortic dissection and non-dissection surgeries through upper hemisternotomy are safe and can significantly improve the short-term postoperative efficacy after achieving proficiency, but the latter approach has a shorter learning curve.

Key words: upper hemisternotomy; aortic surgery; aortic dissection; learning curve