IntroductionPosterolateral thoracotomy was the access of choice in surgical treatment of patent ductus arteriosus (PDA) for many years before the introduction of video-assisted thoracoscopic surgery (VATS). The latter is thought to reduce postoperative pain and improve musculoskeletal system status. However, it carries a potential risk of conversion to thoracotomy.AimTo evaluate the rate, reasons and outcomes of VATS conversion to thoracotomy in surgical PDA patients.Material and methodsFrom 2012 to 2017, 112 children were qualified for VATS closure of symptomatic PDA. Among them, 19 (16.9%) with the median age of 19.4 months required conversion to thoracotomy. The predominant reasons for conversion, early mortality and morbidity as well as late survival were evaluated.ResultsThe overall conversion rate was 16.9% with an evident learning curve as it decreased significantly from more than 20% at the beginning to approximately 10% in the last 2 years. The predominant reasons were incomplete PDA closure (n = 6; 31.6%) followed by ductal bleeding after clip application (n = 5; 26.3%) and inadequate visualization (n = 5). One child died 48 h after the surgery due to acute cardiopulmonary failure (mortality 5.9%). All patients required postoperative chest tube insertion, and two of them developed postoperative pneumothorax. Neither deaths nor severe adverse events were noted throughout the follow-up period.ConclusionsThe rate of VATS PDA closure conversion to standard thoracotomy features a learning curve. Although it must be considered as a serious complication, probably it does not negatively affect either early the mortality rate or long-term survival.