潰瘍性大腸炎の経過に関するX線学的検討―結腸炎と直腸炎との対比

Radiological Study on Prognosis of Ulcerative Colitis: Colitis vs Proctitis

　潰瘍性大腸炎（ulcerative colitis，以下UCと略）は成書的には病変は直腸から始まり，漸次，口側へと進展し，肛門側ほど変化が強いとみなす見解が支配的である．しかし現在の進歩した検査法と診断能とで検討すると，必ずしもそうではない例を多く経験する．ところで，病変には病型と病期があり，腫瘍が非可逆的変化であるのに比し，炎症性疾患は程度の差はあれ，可逆的であることが多い．特にUCは再発・再燃を繰り返す率が高い疾患であるため，UCの経過をX線学的に論じる場合には，どの病型で，どの病期に撮られた写真であるかを常に考慮しておかねばならない．実際，UCを初発時の早期からその成り立ちを観察することは難しく，日常の診療でUCと診断されている例の多くは，検査時には既にかなりの日数を経ており，また何回も再発・再燃を繰り返した例の一時期，病態の一断面をみているにすぎない．だからUCの本態を追求するには，多くの症例を集めて，各断面を埋め合わせると共に，1つ1つの例については経過を経時的または遡及的に検討し，断面をつなぎ合わせることが重要である．これは時間的要素を重視した診断学の概念が加わっており，X線病態学の分野に属すると言えよう．幸いなことに本邦では，西沢，狩谷らにより理論化された注腸二重造影法¹⁾の普遍化と共に，10年を越えるUCの経過観察例も次第にその数が増してきており，その中で狩谷²⁾は最近，病変の固定化という概念を唱えはじめている．本稿では1年以上の間隔で2回以上の注腸検査が施行された例（以下，経過例）にて，注腸X線像の推移を経時的，または遡及的に検討を加え，その変化が結腸と直腸とで差があるか否かを，対比して検討したので，その結果を報告し，UCの本態，自然史の一端を明らかにしたい．

　During the last 12 years (1970～1982), we experience 22 cases of ulcerative colitis who had barium enema examination more than twice with an interval of more than one year. To understand a natural history of the ulcerative colitis, clinical course of the 22 cases were studied radiologically and the results obtained were as follows.

　1) Of the 22 cases, 15 cases (18%) were less than 40 years old at the onset of the disease.

　2) Teenager patients tended to have the involvement of right side colon or entire colon already at the onset of the disease, and tended to have frequent relapses and flare-ups.

　3) Inflammatory polyps were farmed after a severe attack.

　4) Shortening and narrowing of the colon during an active stage were reversible. On the other hand, they were irreversible if they were noted during remission, and the irreversible changes were found to develop in cases which had more than five year clinical course.

　5) In the colon, its shortening and narrowing got worse whenever relapse and flare-ups occured.

　6) So-called ulcerative proctitis of which inflammation is limited in the rectum was seen in two out of 22 cases and its incidence was low.

　7) In cases which severe attacks or repeated relapses and flare-ups, neighther shortening nor narrowing occured in the rectum. Among 22 cases, furthermore, only one case was found to have inflammatory polyps in the rectum.

　The above findings indicate that ulcerative colitis may not necessarily start from the rectum and progress up to the oral site by repeating relapses and flare-ups. The factors which regulate their extent and prognosis were patients age at the onset of the disease, type of the lesion, extent and severity of the lesion. It is also assumed that younger onset of the disease have especially extensive lesion and tends to have relapses and flare-ups. In majority of the cases, the extension of the lesion during relapses and flare-ups did not indicate new up wards extension but worsened and relapsed lesions in the range at the onset of the disease. Furthermore, severity of the lesion was different between the colon and the rectum.

　In general, the shortening and narrowing of the intestine as well as inflammatory polyps tend to occur in the colon, but they are extremely rare in the rectum.