Abstract:Objective To investigate the safety and feasibility of the improved robot-assisted atrial septal defect (ASD) repair under beating-heart(using two robotic arms and two special instruments for robotic surgery),through a retrospective study. Methods From December 2016 to September 2018,47 cases of modified robot-assisted ASD repair under beating-heart were completed in the Department of Cardiovascular Surgery of First Affiliated Hospital of Nanjing Medical University.Based on the steady-state learning curve of cardiopulmonary bypass (CPB) time and operation time made by regression analysis,25 patients from September 2017 to September 2018 were selected as modified robot group;27 patients undergoing ASD repair by 3D thoracoscopy with three-ports were served as 3D thoracoscopic group in the same period.Through femoral artery,vein and internal jugular vein cannulation,extracorporeal circulation was established in both groups.The perioperative situation,operation related data and postoperative follow-up were compared between two groups. Results ASD repair closures were successfully performed without in-hospital mortality or other serious complications in both groups. Regression analysis and learning curve showed that in 47 cases of modified robot-assisted ASD repair under beating-heart,the learning curve for operation time was y=302-41.79 ln(x)(r²=0.904,P<0.01),and the learning curve for CPB time was y=162-40.684 ln(x)（r²=0.877，P<0.01）.There were 12 cases (48.00%) of undergoing tricuspid valvuloplasty simultaneously in modified robot group and 11 cases (40.74%) in 3D thoracoscopic group(P>0.05).CPB duration and postoperative ventilator support time in modified robot group were lower than those in 3D thoracoscopic group,and the operation time was longer than that in 3D thoracoscopic group (P<0.05,P<0.01).There were no significant differences in ICU stay time,postoperative drainage volume and length of hospital stay between two groups (all P>0.05).During postoperative follow-up,no residual shunt or tricuspid regurgitation occurred. ConclusionsModified robot-assisted ASD repair under beating-heart is a safe and effective surgical method,and the operation time and CPB time tend to be stable after the learning curve reaches a steady state.The mothed has advantages in speeding up the completion of microsurgery,shortening the CPB time,reducing the surgical trauma and promoting the rapid recovery of patients with good minimally invasive and cosmetic effects.