Histopathological elements analyzed in dynamics in mechanical bowel obstructions - experimental study on laboratory animals.

Bowel obstruction is a syndrome that produces important alterations to the digestive tract, both macroscopically and microscopically. We conducted an experimental study using rats, Wistar strain, as subjects, dividing them into three groups. The group A consisted of six rats and served as control group, in the first day of the experiment a surgical procedure being performed to resect a small bowel and a colic segment to be analyzed microscopically afterwards. The 10 subjects from group B underwent a surgical procedure, in which we induced a mechanical bowel obstruction in the sigmoid colon, while to the 10 subjects from group C we induced a mechanical bowel obstruction in the small bowel. The initial protocol implied to observe the macroscopic modifications from five subjects from each group B and C after two days and afterwards to resect the digestive tract segment adjacent to the obstruction site. After another two days, a similar procedure was planned for the remaining subjects alive from both groups. A few subjects from group C died prematurely and the initial protocol had to be partially modified. The results highlighted an important distension of the digestive tract proximal to the obstruction, with important microscopically reactions, including edema, thrombosis, ischemic lesions and accumulation of polymorphonuclear neutrophils (PMN) and macrophages.