大腸壁在神経叢の神経細胞の変性・脱落による慢性偽性腸閉塞症の1例

Acquired Hypoganglionosis of the Colon Resembling Pseudo-obstruction, Report of a Case

要旨　患者は31歳，女性．過去に排便に関する異常なく腸閉塞が発症した．妊娠7か月より徐々に便秘傾向となり，たまたま罹患した風疹後，全く便が出なくなり，緊急に人工肛門造設．その後腸閉塞の改善がないため，左半結腸切除術を施行した．X線学的に強い狭窄があったにもかかわらず，病理標本では狭窄はなく，腸閉塞の原因は腸管の攣縮によるものと判明した．病理組織学的には，粘膜・筋層の異常はなく，粘膜下および筋層間神経叢の神経細胞の変性・脱落が認められた．これが腸管の攣縮を引き起こしたと考えられた．この神経細胞の変性・脱落は妊娠＋風疹によって生じたと推測された．

　A 31-year-old woman, gravida 2, para 2, visited our hospital in September 1982 with severe obstipation. Her history of constipation had begun in April 1982 in the seventh month of pregnancy. After she had rubella in May 1982 she could not move bowel movement. She delivered a premature baby on May 28, who died twenty days postpartum. She visited another hospital on May 30 with obstructive symptoms, including abdominal cramps and vomiting. Abdominal film revealed megacolon. On the first day of hospitalization a descending colostomy was performed to decompress the bowel. At surgery, hard fecal mass was found in the descending colon and the splenic flexure; proximal transverse, colon was dilated extremely. The fecal mass was not able to be passed. Postoperatively three barium enema studies revealed the stenotic descending colon. Then she was admitted to our hospital.

　On physical examination she appeared reasonably healthy. The abdomen was slightly distended. There was no tenderness. Results of laboratory studies were within normal limits. Barium enema study showed a narrow segment in the region of descending colon and the splenic flexure. The transverse colon was definitely dilated above the narrow segment. Double contrast study disclosed spastic, wavy margined colon without ulceration. Endoscopic examination revealed spastic, edematous colon with intact mucosal surface. These findings were similar to those in ischemic colitis. Upper gastrointestinal series disclosed no abnormalities. On October 5 a left hemicolectomy was performed with closure of the artificial anus. At surgery, the colon had same appearance at the first operation.

　The resected segment of colon was 41 cm before fixation and showed almost entirely slight narrowing of the lumen. Microscopically, there was thickening of all muscle layers in almost all resected bowel but this occurred especially in the inner circular layer. The Auerbach's and Meissner's plexuses showed loss and/or reduction in the number of ganglion cells with a slight, resultant increase in Schwann cells. A few remaining ganglion cells were swollen and some of them had bizarre shapes and multinucleated giant cell-like appearance.

　Postoperatively she discharged on the thirty hospital day having had regular, soft bowel movements. She continues to do well two years postoperatively.

　We believe that acquired colonic hypoganglionosis in this case may have resulted from enteric circulatory ischemia due to pregnancy and from rubella virus infection.