虚血性腸病変の臨床像―虚血性大腸炎の再評価と問題点を中心に

Clinical Features of Ischemic Lesions of the Intestine: Focused on Ischemic Colitis

要旨　筆者らが経験した虚血性大腸炎82例の臨床像を分析した．その結果，①狭窄型（21例）と一過性型（61例）の比較では，年齢，下血の有無，併存疾患の有無，発病5日以内の血沈1時間値が有意に異なっていた，②若年者群（44歳以下の20例）と高齢者群（70歳以上の16例）の比較では，発症前の便秘の有無，病型，発病4日以内の血沈1時間値に有意差を認めた，③狭窄型21例中5例にX線上管状狭窄を認め，治癒が遷延した，④再発が5例（6.1％）にみられた．本症の診断に際しては，糞便あるいは生検組織の細菌培養（特に病原大腸菌感染の除外）が重要と考えられた．虚血性大腸炎以外の虚血性腸病変として，閉塞性大腸炎，虚血性小腸炎，経口避妊薬服用後の虚血性大腸炎，腹部外傷後の虚血性腸炎，静脈硬化症による虚血性腸病変，アミロイドーシス，膠原病，放射線腸炎，Schönlein-Henoch紫斑病，宿便性潰瘍，急性出血性直腸潰瘍が挙げられる．また，病原大腸菌（O157：H7）による感染性大腸炎，合成ペニシリン起因性大腸炎，潰瘍性大腸炎，Crohn病でも虚血性変化の関与が疑われている．虚血性腸病変の分類は，臨床像と病因を加味して行うことが重要である．

　Eighty-two cases of ischemic colitis were analyzed for its clinical features. The results were summarized as follows. 1) There were significant differences in the following four items between 21 cases of the stricturing form and 61 cases of the transient form; the age, melena or hematochizia, diseases associated with arteriosclerosis, and one hour value of erythrocyte sedimentation rate in the 5 days since the onset of symptoms. 2) The transient form of ischemic colitis and constipation prior to the onset of symptoms were more common in young patients (20 cases of 44 years old and under) than in older patients (16 cases of 70 years old and over). 3) Five out of 21 patients with the structuring form had tubular narrowing and delayed healing which were shown by x-ray examination. 4) There was recurrence of the disease in 5 patients (6.1%). 5) Negative cultures of bacteria including enterohemorrhagic Escherichia coli were important for the diagnosis of ischemic colitis.

　As ischemic lesions of the intestine excluding ischemic colitis, there are obstructive colitis, ischemic enteritis, ischemic colitis caused by oral contraceptives, posttraumatic ischemic stricture, ischemic lesion due to phlebosclerosis, amyloidosis, collagen disease, radiation enteritis, Schönlein-Henoch purpura, stercoral ulcer, and acute hemorrhagic ulcer of the rectum In addition to above diseases, ischemic lesions may be caused by Escherichia coli O157: H7-associated coliris, non-pseudomembranous penicillin-related colitis, ulcerative colitis, and Crohen's disease. Pathogenesis as well as clinical features should be discussed for the classification of ischemic lesions of the intestine.