MICROANGIOGRAPHIC STUDY OF ULCERATIVE COLITIS ASSOCIATED WITH MORPHOLOGICAL DIFFERENCES

In order to know the clinicopathological features of ulcerative colitis (UC) in more detail, the vascular patterns were morphologically investigated by microangiography of surgical specimens. Seven patients with UC treated by surgical resection were subjected to this study. 1) The vascular disarrangement of UC were mainly mucosal and submucosal vessels. Muscular and/or subserosal layers maintained the normal vascular patterns even though the muscular and submuscular vessels were extremely disarranged. The lack of convergent vascular coursings toward the surface of ulceration in UC was observed. 2) Inflammatory polyps, in which there were the penetrating vessels originated from muscularis propria, were classified into 2 groups, i.e., proliferative inflammatory polyp and mucosal tags formed by the ulceration. 3) Pseudopolyposis types of UC were composed of the proliferative inflammatory vessels, whereas the vessels of atrophic types were greatly altered, tortuous and irregularly narrowed in reflection to pathologically muscular thickness. Toxic megacolon showed thin proper muscle layer, mucosal tags with normal vascular pattern and the lack of mucosal vessels in ulcerated zones. 4) The vessels beneath mucosa in zones of healed ulcer still remained dilated and proliferative, which was suspected a factor affecting the ulcer recurrence. The vascular patterns of UC appeared to be a response to the inflammatory component of UC and to affect promotion or improvement of colitis in relation to the pathogenesis of the disease.