Micro-stucture of Mucosal Surface and Microvascular Architecture in Ulcerative Colitis

We studied the mucosal surface and microvascular architecture in ulcerative colitis by a dissecting microscope. Microphil injection, mucosal staining by alcian-blue or hematoxylin and alchol-methyl salicylate clearing were performed for 8 resected colons of ulcerative colitis (7 cases ; operation, 1 case ; autopsy). Normal mucosal surface of colon showed regular arrengement of oval pits (50 microns in diameter) and regular superficial capillaries with honeycomb pattern. On the surface of ulcers and erosions, the aggregation of markedly dilatated capillaries were observed, but no pits were found. At the early stage of the mucosal regeneration, large and deformed pits such as sulciolar pits disclosed, and many dilateted superficial capillaries with complex anastomosis each other were observed. According to the regeneration, oval pits incresed and simple honeycomb pattern of the superficial capillaries was observed. At the ulcer and it's regenerative mucosa, submucosal vascular network disappeared, and the perpendicular vessels were observed in the submucosal layer. On the other hand, at the erosion and it's regenerative mucosa, markedly dilatated and coiled submucosal vascular networks were observed. Further, we investigated pseudo-polyps, mucosal bridges, atrophic areas, and crypt abscessiss. It was suspected that gastric area-like structure observed on the regenerative mucosa was formed according to regeneration of many micro-erosions. Restricted microvascular dilatation and increasing in the mucosa were observed on the macroscopically normal mucosa of ulcerative colitis.