INTESTINAL ANASTOMOTIC LEAK: HISTOLOGICAL AND IMMUNOHISTOCHEMICAL ASPECTS

Summary. The aim. Improving the results of treatment of patients with intestinal anastomotic leak by determining the role of undifferentiated connective tissue dysplasia in the development of these complications. Materials and methods The object of the study comprises 45 patients with anastomotic leak and with phenotypic signs of undifferentiated connective tissue dysplasia, who were treated in the Shalimov National Institute of Surgery and Transplantology during 2017-2020. Laboratory, histological, immunohistochemical studies and statistical analysis were performed. Results and discussion. With comprehensive study of tissue fragments small and large intestines revealed similar morphological characteristics in groups of phenotypic traits undifferentiated connective tissue dysplasia and with intestinal anastomotic leak. In immunohistochemical study of tissues with monoclonal antibodies to α-smooth muscle actin revealed uneven focal expression in smooth muscle cells and fibroblast; with monoclonal antibodies to Collagen IV there is a moderate positive expression in the basement membrane of blood vessels, in smooth muscle cells of the muscular layer of the vascular wall, in areas of connective tissue. Conclusions. Immunohistochemical examination of small and large intestinal tissues with monoclonal antibodies to Collagen IV and α-smooth muscle actin revealed signs of pathological connective tissue remodeling in the areas of anastomotic leak.