ObjectiveTo investigate the changes in pulmonary function after video-assisted thoracic surgery (VATS) and robot-assisted thoracic surgery (RATS) segmentectomy.MethodsA total of 59 patients (30 males and 29 females) who underwent segmentectomy in the Affiliated Hospital of Qingdao University from July to October 2017 were included. There were 33 patients (18 males and 15 females) in the VATS group and 26 patients (12 males and 14 females) in the RATS group. Lung function tests were performed before surgery, 1 month, 6 months, and 12 months after surgery. Intra- and inter-group comparisons of lung function retention values were performed between the two groups of patients to analyze differences in lung function retention after VATS and RATS segmentectomy.ResultsThe forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in the VATS group and the RATS group were significantly lower than those before surgery (P<0.05), and they increased significantly within 6 months after surgery (P<0.05). The recovery was not obvious after 6 months (P>0.05), and they were still lower than those before surgery. In addition, the retentions of FEV1 and FVC in the VATS group and the RATS group were similar in 1 month, 6 months, and 12 months after operation with no statistical difference(P>0.05). ConclusionPulmonary function decreases significantly in 1 month after minimally invasive segmentectomy, and the recovery is obvious in 6 months after the operation, then the pulmonary function recovery gradually stabilizes 12 months after surgery. FEV1 of the patients in the two groups recovers to 93% and 94%, respectively. There is no statistical difference in pulmonary function retention after VATS and RATS segmentectomy.