EXPERIMENTAL MODELING OF ADHESION DISEASE IN RATS

Abstract

The persistent causes of adhesion formation in the abdominal cavity remain inflammatory processes, previous abdominal surgeries, blunt and sharp abdominal trauma, including those of military origin, and congenital adhesions. According to the literature, peritoneal adhesion disease remains common in emergency surgery, with its incidence showing no decline. Acute adhesive intestinal obstruction ranks first among causes of intestinal obstruction of various origins. The severity of complications and postoperative mortality related to this condition show no tendency to decrease.

Currently, there are no experimental methods for inducing adhesion formation in the abdominal cavity of rats that closely mimic practical surgical conditions.

Objective: To develop and study, in an experimental setting, the morphological manifestations of the adhesion process using our proposed method of inducing adhesions in the abdominal cavity of rats, which would be as close as possible to the current clinical requirements of operative surgery.

Materials and Methods: Laparotomy, macroscopic, microscopic, histological examination (preparation of slide specimens), staining with hematoxylin and eosin, statistical analysis using Fisher’s exact test, determination of median adhesion formation frequency, interquartile range, and confidence interval for the median.

Results: No adhesions formed in animals of the control group. In the second group, on day 7 after adhesion induction, 90 % of rats showed thin membranous avascular adhesions that were easily disrupted. In the third group, on day 14, adhesions were observed in 90 % of animals; these were denser, partially vascularized, and required blunt or sharp dissection. In the fourth group, on day 21, 80 % of rats exhibited dense adhesive bands with high vascularization. Histologically, a transition was noted from granulation tissue with dense infiltration (day 7) to mature fibrous tissue with minimal signs of inflammation (day 21).

Conclusions: Injury to the parietal peritoneum alone during laparotomy does not lead to adhesion formation. In most rats, the adhesion process progressed sequentially from thin membranous formations to dense fibrous tissue with vascularization. The visceral peritoneum was more prone to adhesion formation compared to the parietal peritoneum. Involvement of uninjured organs in the adhesion process indicates a systemic pathological process extending beyond local injury.