BACKGROUND AND PURPOSE: To undertake a morphometric comparative study of the longitudinal and circular layers of the small bowel muscularis propria in rats, whom underwent surgical construction of one and two pylorus in the small bowel, utilizing the technique of the creation of two pylorus described by Rena et al. METHODS: 52 male Wistar rats were divided in three groups. Group A, 10 animals, was defined as the control group, and 20 mm of the bowel segment were removed for the study. Group B animals underwent construction of two pylorus, with one at 100 mm and the second at 150 mm from the ileo-cecal valve, 10 animals. Animals from group C, 32 animals, underwent construction of one pylorus at 100 mm from the ileo-cecal valve. The rats were sacrificed at ten days after the procedure. The morphometric analysis of the longitudinal and circular layers of the muscularis propria above and below the pylorus were studied with the help of a microscope Axiostar Plus model connected to the Axioncam camera version 5.05.10 with 5x/0,12 objective utilizing the software Axion Vision 3.1.2.1. RESULTS: The bowel loops demonstrated thickening of the muscular layer in segments above and below the point where the surgical procedure took place. The morphometric comparative study of the longitudinal and circular muscular layers demonstrated significant increase when compared to the control group. There were no significant differences among groups B and C. CONCLUSION: The results demonstrated significant increase in muscle layers, however not to the point of the increase reported in the literature for animals that underwent fixed stenosis. These data indicates that surgical construction of the pylorus by the technic used by us promotes muscular changes of minor significance, possibly, by the valvular function of the pylorus.
Intestine, small; Muscle, smooth; Hypertrophy; Hyperplasia; Short bowel syndrome
