Structural and Functional Transformation of the Small Intestine Wall in the Conditions of the Functioning of the Artificial Urinary Reservoir in the Experiment

Abstract

Morphological changes of the wall of the artificial urinary bladder are various and its investigation continues from the moment of the creation of the first conduit on the ileum’s section. The aim of the work is to explore the structural-functional transformation of the mucous and the neobladder wall in 12 months after ileocystoplasty in the experimental conditions on mini-pigs. The results of the neobladder’s experimental model, created by the execution of cystectomy and ileocystoplasty in 9 experimental mini-pigs are the material of this work. 12 months after the operation of modeling the urinary bladder, animals were removed from the experiment of nembutal overdosing, following the provisions of “The European convention for the Protection of vertebrate animals being in use for experiments or for other scientific purposes”. Our morphological changes of the artificial urinary bladder, formed from the segment ileum 12 months after the orthotopic ileoplasty proved significant ultra-structural changes in the neobladder’s epithelial layer. Ileum’s villi within the conditions of the artificial urinary bladder are decreased and smoothed, epithelial cells are similar to the interjacent epithelium. The connective-tissue plate is thickened and becomes callous, the muscular layer is also thickened. The samples of the ileum, that remained in the normal environment without the compatibility with urine, did not undergo the significant morphological transformations and did not differ from the samples of the intact ileum. The transplantation of the ileum segment for performing new, not-programmed functions causes it to adapt to new conditions, although the urinary bladder and the ileum have different origins and structures from the very beginning. New aggressive conditions and constant contact with urine lead to the transformation of the mucous of the ileum and acquire new features necessary for performing new functions.