Kovalov A. Prediction and prevention of acute adhesive small bowel obstruction

Experimental part of the work on modeling Acute adhesive small bowel obstruction (AASBO) and evaluating the effectiveness of the method of prevention of adhesion was performed in the vivarium KMAPO. Experimental studies involved 104 Wistar rats weighing 160-220 g, of which 2 groups were formed - the main (96 rats) and the comparison (8 rats). The main group was divided into 3 subgroups. Animals of the first subgroup were simulated AASBO according to the method developed by us with the artificial formation of annulments of the small intestine (patent of Ukraine №138593 G09B 23/28 (2006.01) from 10.12.2019 Bull. № 23/2019). Experimental animals of this subgroup did not prevent adhesion formation, but studied the morphological changes of the intestine and mesentery of the small intestine with progressive AASBO. Animals of the second subgroup, which were also simulated AASBO according to the method developed by us and on the 3rd day of the experiment performed relaparotomy with the elimination of AASBO, by dissection of adhesions and removal of the suture of the small intestine. A solution of Polyethilenglicol (PEG) 4000 was injected into the abdominal cavity to prevent adhesions. Animals of the third subgroup after simulation of AASBO according to the method developed by us also performed relaparotomy with elimination of obstruction. Intra-abdominal prophylaxis of adhesions was performed with the drug "Dekasan". According to the plan, the animals were removed from the experiment on 3,7,14,28 days of the experiment. Part of the animals of the first subgroup died prematurely on the 9th and 10th day of the experiment from the progressive phenomena of intestinal obstruction. Preparations of experimental animals were studied using standard morphological and immunohistochemical techniques. In our study, we proved the effectiveness of our proposed method for modeling AASBO, the effectiveness of which was confirmed morphologically. Thus, it was shown that in the absence of local prophylaxis of ADP, with increasing experimental time, the processes of formation of intestinal adhesions, represented by a layer of granulation tissue with a predominance of fibrous and reduced cellular and vascular components. In the fibrous component of granulation tissue at earlier stages (3 days) only immature collagen of type III was noted, and at later stages mature collagen of type I was also determined. With the intensification of adhesions in the wall of the small intestine, there was an increase in the severity of dystrophic, necrotic, inflammatory and vascular changes. Alternative changes began on the part of the mucous membrane (most sensitive to ischemia and hypoxia) of the small intestine.