Histological and histochemical changes of the intestinal mucosa at the urothelial-enteric anastomotic site

Abstract

Objective: The incorporation of bowel segments for urinary tract reconstruction may induce intestinal mucosal changes with the development of metabolic, nutritional, gastrointestinal and carcinogenic complications. The early histological and histochemical changes of the intestinal mucosa in contact with the feces-urine mixture, are evaluated in the present study. Materials and Methods: Twelve rats (operated group) were submitted to a vesico-colonic anastomosis, and 10 rats (control group) underwent a sham operation (the colon was opened and immediately sutured). On the operated group, the left colon was divided into 3 equal portions and the middle segment was used for the bladder-colonic anastomosis. After 20 weeks, the animals were sacrificed and the entire left colon in each group, as well as the bladder and the vesico-colonic anastomosis in the operated group, was removed. The proximal, middle (anastomotic site in the operated group and sutured portion in the control group) and distal colon were used for histological and histochemical studies. Results: Metaplasia, chronic inflammatory process and fibrosis were significantly greater at the anastomotic site compared to the middle segment of the control group. There were no differences in both groups in terms of dysplasia, atrophy and hypertrophy either on the proximal, middle or anastomotic area and distal portion of the left colon. All animals in the operated group showed a reduced presence of sulfomucin and an increase in the sialomucin content. Conclusion:The histological changes observed in this study may suggest a precancerous phenomenon.

Quantification by computerized morphometry of tissue levels of sulfomucins and sialomucins in diversion colitis in rats

“…Some authors consider that this change in the inflamed epithelium might precede the development of neoplasia, thus making it useful to investigate the tissue expression of mucins, in order to evaluate the risk of malignant transformation 12 . This evidence is corroborated by the results from experimental studies that demonstrated increased sialomucin production in colon mucosal cells in segments without fecal stream that were used to reconstruct the urinary transit 13 . Since patients who undergo ureterosigmoid diversion present a greater risk of developing neoplasia, it is possible that modifications to the tissue expression of mucins might also be considered in such patients to be a potential histological marker capable of predicting the risk of developing neoplasia 14,15 .…”

“…distribution pattern in the intestinal epithelium have been demonstrated in various diseases that affect the colon [11][12][13] . Studies using biochemical, histochemical and immunohistochemical techniques have demonstrated that, in the different forms of colitis, abnormalities occur not only in the tissue content but also in the expression pattern of mucins along the crypts of the colon mucosa 21,22,[30][31][32][33] .…”

Tissue quantification of neutral and acid mucins in the mucosa of the colon with and without fecal stream in rats

“…The expression of mucins in the colon epithelium is well known and can be categorized by histochemical techniques as neutral or acid 9 . According to their content of sialic acid or sulfate, the acid mucins are, in turn, subdivided into sialomucins and sulfomucins 9,21 .…”

“…It has also been shown that such changes may even precede the development of neoplasia 7,8 . Likewise, changes to mucin synthesis and distribution along the mucosa of colon segments without fecal stream that are used as reservoirs or by-pass for reconstituting the urinary transit have been demonstrated 9,10,11 . This suggests that alterations to the expression of these glycoprotein might, in these patients, be considered to be precursory changes for neoplasm development 9,10 .…”

“…Likewise, changes to mucin synthesis and distribution along the mucosa of colon segments without fecal stream that are used as reservoirs or by-pass for reconstituting the urinary transit have been demonstrated 9,10,11 . This suggests that alterations to the expression of these glycoprotein might, in these patients, be considered to be precursory changes for neoplasm development 9,10 . Despite the histopathological similarities between UC and DC, to the best of our knowledge, only a single experimental study has evaluated, specifically, the quantification and modifications to acid mucins expression in experimental model of DC 5 .…”