腹腔鏡下下行結腸癌手術後に発症した吻合部肛門側壊死型虚血性腸炎の1例

A case of gangrenous ischemic colitis after laparoscopic colectomy for descending colon cancer, isolated by anastomosis and located at anal side colorectum

◆要旨：今回，腹腔鏡下下行結腸癌根治手術後に虚血性腸炎を発症した1例を報告する．患者は65歳，男性．手術施行後半年で虚血性腸炎を発症して入院した．吻合部により炎症範囲が明確に境界された肛門側結腸および直腸に病変を認めた．保存的治療が奏効せず病状は増悪し，腹会陰式直腸切断術を施行した．虚血性腸炎は心血管系疾患，糖尿病，高血圧や便秘など便通異常を有する高齢者に頻度の高い疾患で，血管炎以外の末梢循環系の異常により引き起こされるとされているが，詳細な病因は未だ明らかにされていない．本症が大腸癌術後晩期に，吻合部肛門側に発症した文献報告は比較的稀であり，術後静脈環流障害が病状に影響した可能性を考察した．

　A 65-year-old man underwent laparoscopic colectomy for descending colon cancer （T3N0M0 c-Stage II）. Inferior mesenteric vein was ligated for D3 lymph nodes dissection, but inferior mesenteric artery and supra rectal artery were preserved. Six months later, the patient had ischemic colitis which was isolated by anastomosis and located at the anal side colorectum. He was unresponsive to less invasive therapies and finally needed abdominoperineal resection of the rectum, including anastomosis. Ischemic colitis usually occurs to aged patients with cardiovascular disease, diabetes, hypertension and chronic constipation. Although peripheral circulatory failure excluding vasculitis is said to be related, the etiology of this disease is still unknown. Late-onset ischemic colitis at anal side of anastomotic colorectal lesion, after colorectal cancer surgery, is rare. It might be possible that post-operative impairment of venous outflow has affected the progression of this disease.