Pathologic features of the ureteroileal anastomosis in ileal conduits in childhood.

Ileal conduit urinary diversions are associated with a high incidence of late complications often requiring major revision surgery. Although the etiology of the late complications is not always clear, there may be unilateral or bilateral hydroureteronephrosis, with the conduits showing narrowing and stricture formation with villous atrophy, chronic inflammation, and fibrosis. Histologic review of 20 ureteroileal anastomoses from 12 patients showed variable degrees of chronic changes. In addition, cystically dilated intestinal glands were noted in six anastomoses, transitional epithelial-lined cysts were noted in nine, aggregated pools of mucus were noted in four, mixed transitional and intestinal epithelial-lined cysts were noted in two, and polypoid lesions with mucus pools or cysts projecting into the lumen were noted in five. Twelve cysts measured over 1 mm in diameter; six measured over 2 mm. These histologic features may result from overgrowth of intestinal glands by transitional epithelium, with subsequent gland dilatation, rupture, and mucus pooling. It is possible that the larger "cysts" and "polyps" may have contributed to the ureteroileal obstruction, a finding that may have bearing on other types of urinary tract reconstructions using bowel segments.