S状結腸癌術後の気管分岐部単独リンパ節転移に対して腹臥位胸腔鏡下腫瘍摘出術を施行した1例

Thoracoscopic resection in prone position for posterior mediastinal lymph node metastasis from sigmoid colon cancer

◆要旨：患者は52歳，女性．S状結腸癌に対し腹腔鏡下S状結腸切除術を施行した．術後1年9か月で右肺S¹⁰に転移を認め，胸腔鏡下右肺部分切除術を施行した．肺切除4年後に，CTで気管分岐部リンパ節の腫脹を認めた．生検で腺癌の転移と診断した．PETにて同部位以外に集積を認めなかったため，手術の方針とした．手術は腹臥位胸腔鏡下腫瘍摘出術を施行した．腫瘍は気管分岐下に認め，周囲への浸潤を認めなかった．迷走神経の肺枝1本のみ切離し腫瘍を摘出した．経過良好で術後3日目に退院した．病理学的所見にてS状結腸癌の転移と診断された．中・下縦隔腫瘍に対して腹臥位胸腔鏡下手術は左側臥位と比較して術野展開が良く，手術操作性も良好であるため手術法の選択肢の1つと考えられた．

　The patient was a 52-year-old woman with a mediastinal tumor. She had a history of laparoscopic-assisted sigmoid colectomy for sigmoid cancer and postoperative adjuvant chemotherapy. One year and 9 months later, she underwent resection of segment 10 of the lung because of lung metastasis. Four years later, computed tomography revealed subcarinal lymphadenopathy. The diagnosis of a lymph node metastasis from sigmoid cancer was confirmed by endoscopic ultrasound-guided fine-needle aspiration biopsy of the tumor. High FDG uptake by this tumor was seen on positron emission tomogramphy-CT. The mediastinal tumor was removed completely by thoracoscopic resection with the patient in a prone position. Intraoperatively, the tumor didn't adhere to surrounding tissue, and was completely resected with a pulmonary branch of vagus nerve. The postoperative course was uneventful, and the patient was discharged on postoperative day 3 with no complications. Compared to the left lateral position, the prone position provides a much better exposure of the operating field in the inferior mediastinum, and we recommend using this position whenever the tumor is located in this region.