Several complications of robot-assisted partial nephrectomy (RAPN) have been reported; however, there are limited data on thoracic findings and complications. We investigated the risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy. MethodsThis retrospective cohort study included 84 consecutive patients who underwent robot-assisted partial nephrectomy with the da Vinci Si System and the AirSeal TM Insufflation System. Based on chest radiography findings obtained postoperatively in the operating room, patients with and without atelectasis or pneumomediastinum were categorized into Groups A and B, respectively. Patient characteristics (age, sex, body mass index (BMI), RENAL nephrometry score, tumor size, and surgical approach) and perioperative outcomes (total operative time, console time, warm ischemic time, and estimated blood loss) were compared using the Mann-Whitney U test and chi-square test. A multivariate logistic regression analysis was performed to identify the risk factors associated with atelectasis or pneumomediastinum. ResultsGroups A and B included 31 and 53 patients, respectively. Although the rate of the retroperitoneal approach was significantly higher in Group A than in Group B, the other parameters and perioperative outcomes did not differ. The multivariate logistic regression analysis showed that the retroperitoneal approach and high body mass index were risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy. However, these abnormal findings disappeared spontaneously without requiring postoperative treatment. ConclusionsThe retroperitoneal approach and high body mass index may be risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy.