Pathomorphological manifestations of ischemic involvement of the small intestine in acute occlusion of the mesenteric artery

Relevance. Lethality rates (63-95%) among patients with acute intestinal ischemia remain consistently high during the last decades. Despite the high urgency of the problem and numerous works devoted to visualization, early laboratory and instrumental diagnostics of ischemic bowel disease, clinical results have not changed significantly during the last 15-20 years. Pathogenetic mechanisms of various variants of ischemic intestinal lesion and their pathomorphological manifestations should become the basis for the development of surgical tactics and require specification. The aim is to study pathomorphological manifestations and to clarify on their basis the pathogenetic mechanisms of ischemic involvement of the small intestine in acute occlusion of the mesenteric artery in the experiment. Materials and methods. An experimental study was performed on 10 laboratory animals - male rats of the Wistar line. Modeling acute mesenteric ischemia was carried out via dressing of the jejunal artery. The ischemic intestine was collected for a stepwise histological study, the morphometry of the layers of the intestinal wall and the prevalence of necrosis. Results. At the time of the appearance of macroscopic signs of lack of vitality in the central sector of the ischemic intestine, the wall thickness was 47.6% less than normal and in the adjacent peripheral sectors by 40.6%. Thinning of the intestinal wall was due to alteration of the mucosa with a decrease in its share in the total wall thickness from 86 to 82% (p = 0.021) in all sectors. The share of area occupied by necrosis in groups B and C was not statistically significant (p = 0.872) and amounted to 17.1 [7.3; 64.9]%. The state of the intramural vessels of the intestinal wall had significantly changed in comparison with the intact intestine. Signs of hypoperfusion in the form of sludge in the microvessels of the mucous membrane and the submucosa had been revealed. Conclusions. Pathomorphological manifestations of ischemic bowel disease in acute occlusive mesenteric ischemia resulted in a decrease in the total thickness of the wall and a change in the ratio of serous-muscular and mucosal-submucosal layers due to a decrease in the proportion of the latter. The severity of necrosis in the central and peripheral parts of the ischemic intestine did not differ.