6) 虚血性腸炎

Ischemic Enteritis

要旨　虚血性小腸炎は，腸管の微小循環障害による可逆性の虚血性病変である．狭窄型の報告が多くを占め，60歳代の男性に好発し，初発症状は突発する腹痛，嘔気・嘔吐で，慢性期にはイレウス症状を認める．高血圧，虚血性心疾患などの基礎疾患を伴うことが多い．好発部位は回腸であり，狭窄型では慢性期に小腸X線造影や小腸内視鏡検査で全周性の管状狭窄，口側腸管の拡張などの所見を認める．病理組織学的所見として，腸管壁の肥厚を伴う境界明瞭な管状・求心性狭窄と同部の全周性潰瘍，粘膜下層を中心とする線維化，比較的強い慢性炎症細胞浸潤などが特徴である．狭窄型虚血性小腸炎は保存的治療により改善する可能性は少なく，手術が必要になる場合が多い．

　Ischemic enteritis is a reversible ischemic lesion caused by a miniature circulatory disease of the intestine. Stricturing types are often found and the average age of the patients is 62.5 years. The initial symptoms include abdominal pain and nausea/vomiting, and show an ileus symptom in the chronic stage. The patients tend also suffer from hypertension, ischemic heart disease, et al. The lesion is most frequently found in the ileum. Radiography and enteroscopy of the small intestine show concentric tubular stenosis, dilated proximal bowel and multiple small ulcers. The macroscopic finding of the resected specimen in this case revealed concentric tubular stenosis, segmental annular ulcer, and marked thickening of the wall. The histological characteristics of the lesions are fibrosis mainly in the submucosa and are relatively marked by inflammatory infiltrate consisting chiefly of lymphocytes and plasma cells. Ischemic enteritis of the stricturing type is progressive and results in complete stricture, so requires an operation.