Preparation of a pig experimental model of defective colon anastomosis - review

Anastomotic leak is a serious complication in colorectal surgery. The problem of intestinal anastomosis healing disorders is dealt with by a number of experimental studies, especially in applied research. The design of animal models is diverse and the results of individual studies are difficult to compare. This paper summarizes the main issues of planning animal models of intestinal anastomoses, which are discussed individually. The main part of the text is a description of the defective intestinal anastomosis model of the pig. The anastomosis is constructed in the model with a localized mucosal protrusion. The animals are monitored for 3 weeks postoperatively, the clinical condition and changes in vital values and laboratory parameters are monitored, and CT examinations are performed at defined points. At the end of the observation period, samples are taken, macroscopic findings in the abdominal cavity are evaluated, adhesions are scored, and signs of leakage or passage disorders are assessed. The preparations are evaluated histologically both by standard methods analyzing vascularity, inflammatory infiltration and the proportion of collagen, and by methods developed de novo for the needs of the experiment, such as the analysis of the integrity of the intestinal wall at the site of the mucosal protrusion. We value the experimental model for the possibility of a systematic and detailed analysis of the healing state of the anastomosis in combination with a detailed observation protocol, which produces clinically relevant results.