MORPHOMETRY OF THE SMALL-INTESTINE IN PIGS WITH ILEORECTAL ANASTOMOSIS

IIeo-rectal anastomosis (IRA), which is frequently used to measure pre cecal digestibility in pigs, could induce some disturbances of the nor mal absorptive function. Our aim was to investigate the effects of dif ferent IRA surgical procedures on the main histologic characteristics of the small intestine in pigs. The 4 different IRA procedures compare d to intact pigs (INT) were the following: either end to end (EE) or e nd to side (ES) with or without preservation of the ileocecal valve (E EV, EE, ESV, ES respectively). At 147 d after surgery, samples of the wall of the duodenum, jejunum and ileum were taken under anesthesia an d histometric examinations were performed on HE- and PAS-colored secti ons to estimate changes mainly of mucosa and muscle layers. The values recorded for villus length, crypt depth, and whole thickness of the m ucosa suggested that the EE procedures disturb the small intestine les s than the ES models. A new parameter, called epithelial quotient and calculated as [(villus length/crypt depth)/mitotic index], was propose d to improve the comparisons. According to this quotient, EE procedure s did not significantly affect the mucosa of the whole small intestine . An increased density of goblet cells was recorded in all operated pi gs along the small intestine, but mainly in the ileum after EE-IRA. Th e lymphatic follicle area was reduced. These findings, which were in a greement with a reduced mitotic index in the ileum of EE-pigs, indicat ed a decreased effect of noxious factors on the small intestinal mucos a in IRA-pigs, especially after the EE-IRA procedure. Some atrophic or hypertrophic effects on the muscle layers were related to the absence or preservation of the ileo-cecal valve. Finally it was concluded tha t i) there was no major disturbance after IRA, and ii) the end to end procedure was most beneficial for the structural integrity of the smal l intestine.