Angio-architecture of the colon in Crohn disease and ulcerative colitis. Light microscopy and scanning electron microscopy studies with reference to the morphology of the healthy large intestine

The etiology and the pathogenesis of the chronic inflammatory bowel diseases known as Crohn's disease and ulcerative colitis have not been defined. Therefore, in this study the main emphasis was placed on description of the pathologic anatomy. Disturbed blood supply and vascular disorders have been discussed as etiopathogenetic factors. The results in the literature are frequently contradictory. For this reason, the vascular system of the colon in Crohn's disease and ulcerative colitis was systematically examined by means of various morphological methods in this study. Microvascular corrosion casting and translucent specimens were taken from operative specimens taken from 12 patients with Crohn's disease and 8 with ulcerative colitis. For comparison, tumor-free parts of 6 colon cancer specimens were examined. The evaluation was done by scanning electron- and/or stereoscopic microscopy. In the presence of chronic inflammatory bowel disease dilatation of the submucosal veins, caliber differences in the tunica muscularis and rarefaction of the penetrating blood vessels were found. In summary, an impairment of the blood flow in the tunica muscularis can be postulated. For the first time, the resulting venous stasis has been described, in contrast to the previously described disturbed arterial blood supply.