腹腔鏡補助下結腸右半切除を施行した右腎回転異常を伴う上行結腸癌の1例

Laparoscopy-assisted resection for a patient with ascending colon cancer and a malrotated kidney : A case report

◆要旨：症例は77歳の男性で，貧血精査目的に紹介された．精査の結果，右腎回転異常を伴う上行結腸癌と診断し，腹腔鏡補助下結腸右半切除術（D3郭清）を施行した．後腹膜アプローチを先行し，右側結腸間膜の授動を行った．術前CT検査より腎門部は腹側を向き，総腸骨動脈分岐部レベルに位置していたことがわかっていたので，副損傷を回避するため頭側にあたる十二指腸付着部から腸間膜根の切開を開始し腎前筋膜上を剝離した．腎回転異常は解剖学的変位を伴うことが多く，術前の十分な解剖学的検討が重要である．また，本症例では十二指腸付着部を腸間膜根切開開始の指標にすることで，安全な手術が可能であった．

　A 77-year-old man presented with anemia. A tumor in the ascending colon and right hilum of the kidney ventral of the bifurcation of the common iliac artery was identified on contrast-enhanced computed tomography （CT） and three-dimensional CT. Under a diagnosis of ascending colon cancer with a right malrotated kidney, laparoscopy-assisted D3 right hemicolon resection was performed. We first employed an approach using retroperitoneal peeling （i.e. retroperitoneal-approach） with an incision at the mesenteric root. Because the right hilum of the kidney was rotated ventrally and laterally （toward the ileocecal area）, the risk of injuring the hilum was associated with the lateral incision of the mesenteric root. Therefore, the mesenteric root was incised from the medial cranial side （duodenal attachment）. The malrotated kidney showed some anatomical anomalies, so careful consideration based on preoperative three-dimensional CT was necessary. In our case, the operation was able to be safely performed due to the landmark of a mesentery incision at the duodenal attachment.