左A4b＋5とA8＋9の分岐異常を有する肺癌症例に対する完全鏡視下肺切除

Experience with Pulmonary Resection under Thoracoscopic Surgery for Lung Cancer Patient with Abnormal Left A4b＋5 and A8＋9 Branching

きわめてまれな縦隔型肺底区動脈の症例に対し，3D-CT血管造影像による術前の異常走行の把握により，完全鏡視下で安全に左上葉切除術を施行することができた例を経験したので報告する．

The case was a 56-year-old man. A nodular shadow of the left upper lobe was found in the chest computed tomography, and a diagnosis of adenocarcinoma was obtained by bronchoscopy. Preoperative 3-dimensional computed tomography （3D-CT） angiography indicated an extremely rare pulmonary artery bifurcation abnormality in which A4b＋5 and A8＋9 bifurcate from the left main pulmonary artery. Thoracoscopic left upper lobectomy and lymph node dissection were performed. Pathological diagnosis was adenocarcinoma with pStage ⅠB.

The mediastinal basal pulmonary artery is extremely rare, and to our knowledge, the bifurcation pattern of this case has not been reported elsewhere. The 3D-CT angiography was useful to detect the anatomical vascular abnormalities of the pulmonary artery before surgery, for the safe performance of the thoracoscopic surgery.