BackgroundDue to advances in video-assisted thoracic surgery (VATS), the majority of lung resections can be performed safely via VATS with low morbidity and mortality. However, pulmonary artery (PA) bleeding often requires emergency conversion to thoracotomy, potentially leading to a life-threatening situation. We report a case of pulmonary artery injury caused by an unexpected stapler-tissue interaction during uniportal VATS lobectomy, highlighting the importance of recognizing and managing such rare complications to improve patient outcomes.Case presentationA 63-year-old man underwent uniportal VATS left upper lobectomy for a suspected primary lung cancer. During the procedure, unexpected bleeding occurred from the third branch of the pulmonary artery (A3) after withdrawal of an unfired stapler. The protruding staple of the A3 stump was inadvertently hooked and stretched by the groove of the staple anvil. Although the bleeding was controlled by compression with the lung, the injured A3 stump required repair. Due to the extensive intimal injury near the central part of the left main pulmonary artery and the potential risk of fatal postoperative complications, we converted to open thoracotomy for definitive vascular repair by suturing. The patient had no postoperative complications and was discharged on postoperative day 8.ConclusionsThis case report provides valuable lessons regarding the rare stapler-related vascular injury during uniportal VATS lobectomy. It is important to note that even during non-vascular dissection, unexpected stapler-tissue interactions can lead to bleeding. To prevent the vessel stump entanglement with stapler components, maintaining separation between the stapler and staple stumps is crucial. In uniportal VATS, manipulation during stapler insertion is one of the most challenging phases for instrument interference, requiring increased caution to prevent complications such as the vascular injury described in this case. Thorough preoperative planning, specific intraoperative precautions, and adapted safety protocols that address the limitations of uniportal VATS are essential for effective management of potential complications. Although techniques for thoracoscopic vascular control exist, they are not always feasible and conversion to open thoracotomy should be considered when necessary to ensure patient safety.