SOME FEATURES OF THE KIDNEY SCAR FORMATION AFTER SURGERY IN THE EXPERIMENT
Authors:   Federal Research Center of Fundamental and Translational Medicine of the Ministry of Science and Higher Education of Russia, Institute of Molecular Pathology and Pathomorphology, Institute of Chemical Biology and Fundamental Medicine of the Russian Academy of Sciences, Siberian Branch, Maiborodin I.V. , Marchukov S.V. ,   Institute of Chemical Biology and Fundamental Medicine of the Russian Academy of Sciences, Siberian Branch, Maiborodina V.I. ,   Federal Research Center of Fundamental and Translational Medicine of the Ministry of Science and Higher Education of Russia, Institute of Molecular Pathology and Pathomorphology
Published: August 2021

Objective. To study the features of scar formation and structural changes in the remaining renal parenchyma in rats after the kidney resection in various terms. Methods. A layeredclosure of midline laparotomy and the caudal part of the left kidney removal was performed in rats under general inhalation ether anesthesia in a clean operating room. The morphology of the remaining kidney part after resection was studied using light microscope in different terms. Results. Athrombusfrom blood leaking outof the cut vessels is formed on the damaged surface of the kidney immediately after the resection. This clot with the parenchyma is gradually replaced by the connective tissue along the edge of the defect with the subsequently formation of a thin connective or fibrous tissue scar. However, in many cases, the number of which in rats can reach 40%, the processes of kidney damage continue for a long time after surgery, and leading to total or subtotal nephrosclerosis. The detected cystic change in tubular structures, apparently, occurred firstly due to their intersection during the resection, clamping by a blood clot and / or compression by edema distal to the observation site. Then, the forming extensive scar again clamped the adjacent tubular structures with subsequent cystic degeneration and sclerosis. In this case, detritus formed from non-viable renal tissues is eliminated by macrophages, which can form multinucleated cells with fused cytoplasm. Conclusion. Structural changes in the nephrosclerosis progression after kidney resection consist in the gradual replacement of the all renal cortical and medullar parenchyma by the connective tissue. This is not associated with the autoimmune process, but is more likely due to both impaired urine outflow after intercut of the tubular structures at resection and/or compression by edema, inflammatory infiltrate, forming or organizing scar, and vascular disorders associated with these causes. The inflammation accompanying necrosis and sclerosis of the renal structures can become granulomatous. What this paper adds For the first time, it has been shown that the progressively enlarging scar can be formed after the kidney resection, resulting in total nephrosclerosis. Such changes develop both due to the intersection of the tubular structures during the resection and their compression by edema, inflammatory infiltrate, forming or organizing a scar, and vascular disorders due to the above-mentioned causes.