腹腔鏡下S状結腸切除術と直視下D3リンパ節郭清を施行した馬蹄腎合併S状結腸癌の1例

Successful treatment of laparoscopic sigmoidectomy and D3 lymphadenectomy associated with horseshoe kidney : a case report

◆要旨：患者は73歳，男性．S状結腸癌の精査で馬蹄腎の合併を認めた．CTによる血管構築（3D-CTA）と静脈性腎盂造影で血管と尿管の走行を評価して，腹腔鏡下S状結腸切除術，D3リンパ節郭清を行った．体位変換により馬蹄腎は変位するので，主リンパ節郭清の操作ではほぼ水平位に戻した．下腸間膜動脈根部が十二指腸と馬蹄腎峡部に挟まれており，腹腔鏡下での処理は困難と判断し，直視下に主リンパ節郭清と血管切離を行った．また上下腹神経叢が馬蹄腎峡部の前面を走行しており，自律神経温存に注意が必要であった．解剖学的な位置関係を十分に把握し，体位変換や小開腹などの工夫で，馬蹄腎合併の結腸切除でも安全に腹腔鏡下手術が行える．

We report a case of laparoscopic resection of sigmoid colon cancer associated with horseshoe kidney. A 73-year-old male referred for sigmoid colon cancer detected by colonoscopy was recognized by abdominal computed tomography to have a horseshoe kidney. The running of blood vessels and urinary duct were evaluated by three-dimensional CT angiography （3D-CTA） and intravenous pyelography. After preoperative examinations, laparoscopic sigmoidectomy and D3 lymphadenectomy were performed. Since the horseshoe kidney was displaced by postural change, we returned the patient to the horizontal position at the main lymphadenectomy. But, the root of inferior mesenteric artery remained unclear, because it was sandwiched between the duodenum and the horseshoe kidney isthmus. It was determined that treating it laparoscopically would be difficult. Therefore, a main lymphadenectomy and a blood vessel dissection were performed under direct vision from a small laparotomy wound. Moreover, superior hypogastric plexus ran in front of the horseshoe kidney isthmus. Hence, it was necessary to pay attention to the autonomic nerve preservation. If we fully understand the anatomical position relationship and devise a plan, such as postural change, small laparotomy and so on, laparoscopic surgery can be performed safely even in a colectomy associated with horseshoe kidney.