Biological consequences of exposing ileal mucosa to urine.

Abstract

AbstractSegments of ileum are often used as conduits in connection with supravesicle diversion or sometimes for bladder augmentation. This implies that ileal mucosa will be deprived of the normal intestinal contents and instead exposed to urine. Reports on the morphological consequences of exposure to urine have been contradictory. Either normal structure or various degrees of atrophy have been reported. For this reason, an investigation was designed for systematic follow‐up of effects on the ileal mucosa in patients with continent ileal reservoirs for urinary collection (Kock pouch). These investigations showed that there were significant changes in villous height, crypt depth, and number of goblet cells starting early after construction and leading to complete atrophy in certain areas. Electron microscopy and enzyme histochemistry also showed, in the epithelial cells, that there was a reduction in the number of cell organelles and microvillous units, and also decreased metabolic activity. Reductions were also recorded in studies of net transport of both water and electrolytes across the mucosa of the ileal reservoir used for urinary collection.From the clinical point of view, the adaptive changes recorded in the investigations of ileal mucosa exposed to urine are advantageous, since the risk of metabolic disturbances due to reabsorption of urine is diminished.