The common trunk of the left pulmonary vein injured incidentally during lung cancer surgery.

We report a case in which the common trunk of the left pulmonary vein was injured incidentally due to a misunderstanding of the anatomy. After cutting the trunk, we recognized that the vessel included not only the superior but also the inferior component of the pulmonary vein. The cut end of the trunk and the left atrium were successfully anastomosed without any surgical morbidity. Although we retrospectively determined that the common trunk was visualized on preoperative computed tomography, we missed this finding during the preoperative evaluation. Furthermore, because we used the endostapler to cut the vessel, exposure of the pulmonary hilum was too short to identify the anomaly correctly. In the era of the endoscopic devices, exposure of the anatomical structures at surgery has become more limited, resulting in a tendency to misunderstand the anatomy during surgery. Because the common trunk of the left pulmonary vein occurs in 14% of patients demonstrating anatomical variations, thoracic surgeons should be aware of this type of anomaly not only before but also during surgery, and meticulous intraoperative confirmation of the vascular anatomy is required when using endoscopic devices.