Pathogenetic features of formation of strictures of biliodigestive anastomoses during their in experimental modeling

Objective. To create an experimental model of choledochojejunostomy stricture in laboratory animals, which would be as close as possible in its characteristics to clinical conditions, while assessing the role of biochemical markers associated with vascular damage, inflammation and fibrosis in the blood and tissues of the pathological process formation zone, in the development of extrahepatic bile duct strictures.

Materials and methods. All animals were divided into two groups: control (group 1) and main (group 2). The observation time after pathology modeling was 15 and 30 days. Group 1 — a standard choledochojejunostomy was formed on a Roux-en-Y loop; subgroup 2a — a choledochojejunostomy was formed on a Roux-en-Y loop with impregnation of the anastomosis zone with potassium nitrate to form a stricture; subgroup 2b — a choledochojejunostomy was formed on a Roux-en-Y loop with mechanical trauma to the anastomosis zone to form a stricture. After removal, material was collected (a section of the choledochojejunostomy zone) for subsequent morphological and immunological studies.

Results. In the control group (group 1), adequate healing of the anastomosis was noted on days 15 and 30 with the formation of unexpressed scar tissue in the anastomosis zone (as an element of standard regenerative processes during anastomosis formation). In subgroups 2a and 2b against the background of the effect of potassium nitrate on the anastomosis tissue and mechanical trauma, necrosis of the mucosa and deeper tissues was noted with the formation of a scar, formed as in ischemic tissue damage with the development of coarse connective tissue and anastomotic stricture.

Conclusion. As a result of experimental modeling of choledochojejunostomy stricture on laboratory animals, the role of specific biomarkers in establishing the causes of excessive scarring of biliodigestive anastomoses was revealed. The proposed model allows studying the phases of the pathological process and pathogenesis of the development of choledochojejunostomy stricture and outlining ways to prevent its formation in clinical conditions.

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