RESUMEN
INTRODUCTION: currently, endoscopic methods are the main option for surgical treatment of patients with urolithiasis (ICD). The widespread use of these operations has led to the development of a number of specific complications associated with the technology of their implementation. One of the frequent complications is the development of postoperative acute pyelonephritis against the background of intraoperative pyelovenous reflux. THE PURPOSE OF THE STUDY: to study under experimental conditions the severity of pathomorphological changes in the ureter and kidney tissue against the background of pyelovenous reflux in the presence and absence of bacterial flora. MATERIALS AND METHODS: 32 mature female rabbits of the "White Giant" breed were selected as an experimental model. Experimental strain of the E. Coli microorganism 105 KOE/ml. Laboratory animals were divided into 4 groups, 1-3 experimental groups, 4 control group of observation without surgical intervention. In experimental groups, NaCl 0.9% 2.0 ml was injected into the ureteral lumen in group 1, E. Coli 1x105 CFU/ml 1.0 ml in group 2, NaCl 0.9% 1.0 ml + E. Coli 1x105 CFU/ml 1.0 ml in group 3. RESULTS: Results: according to the results of the study, the pathomorphological evaluation of kidney and ureter preparations revealed pronounced inflammatory changes in group 3. CONCLUSIONS: pyelovenous reflux does not independently lead to the development of acute pyelonephritis. The combination of reflux and microbial flora leads to inflammatory changes in the wall of the calyx-pelvic system with the development of acute pyelonephritis, which is confirmed by the results of pathomorphological examination of kidney and ureter tissue.