Techniques to Enhance the Ileal Conduit

Further observations on histological changes at the ureteroileal junction in ileal conduits

Seventy-two ureteroileal anastomoses taken from ileal conduits removed from 62 patients were examined histologically to characterize the range of mucosal and stromal changes at these sites. All 72 demonstrated variable amounts of subepithelial chronic inflammation and fibrosis. Other histological features included: cystic spaces lined by transitional epithelium (N = 29; 40%; average diameter 1.2 mm); cystic spaces lined by mixed intestinal/transitional epithelium (N = 5; 7%; average diameter 0.77 mm); and cystically dilated intestinal glands (N = 21; 29%; average diameter 0.24 mm). The latter were associated with overgrowth by transitional epithelium, which had prevented mucus drainage. Twenty-one (29%) had mucus pools with no epithelial lining (average diameter 1.2 mm), and polypoidal protrusions into the lumen of the anastomosis were found containing mucus pools (N = 4; 6%; average diameter 1.4 mm), transitional-lined cysts (N = 5; 7%; average diameter 2.2 mm), and mixed intestinal/transitional-lined cysts (N = 2; 3%; average diameter 2.5 mm). Focal rupture of dilated intestinal glands with interstitial pooling of mucus was not uncommon, and marked dystrophic calcification was found in 1 case within a large collection of extracellular mucus. This series confirms that inflammation, fibrosis, and glandular overgrowth by transitional epithelium are common occurrences at ureteroileal anastomosis sites. Subsequent gland rupture may result in sizable accumulations of interstitial mucus, and rarely in marked dystrophic calcification.

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.