Abstract:Abstract: Objective?To evaluate the operation security and learning curve of 3D total thoracoscopic atrial septal defect repair.?Methods?From January 2015 to August 2017, 206 ASD patients were enrolled in this study. 3D thoracoscopic ASD repair concomitant tricuspid valve annuloplasty in 44 cases (observation group) while in the same period, conventional thoracotomy (control group) were treated with propensity score matching, and determine the learning curve of 3D thoracoscopic ASD repair technique by the CUSUM analysis method, and analyzed thoracoscopic surgery the clinical effect and safety during the period of learning.?Results?The CUSUM learning curve showed that operative failure rate, operative time, cardiopulmonary bypass time and postoperative complications were 34th, 21st, 29th and 39th patients below acceptable level respectively. There was no significant difference between the two groups of preoperative characteristics after matching. Cardiopulmonary bypass time in the observation group was significantly longer than that in the control group (P?=?0.000). There was no significant difference among the operative time, mechanical ventilation time, ICU monitoring time, postoperative complications and total hospitalization expenses between the two groups (P?>?0.05). The postoperative drainage of the observation group was significantly less than that in the control group (P?=?0.000).?Conclusions?3D thoracoscopic surgery for the repair of atrial septal defect can make endoscopic surgery more simplified and safely. The learning curve stage does not increase surgical complications and hospitalization costs, and can span the learning curve after 39 cases.