STRUCTURAL AND ULTRASTRUCTURAL-CHANGES IN ILEAL NEOBLADDER MUCOSA - A7-YEAR FOLLOW-UP

Objective To investigate the long-term morphological changes in the in testinal segment used to create an orthotopic ileal neobladder, Materi als and methods Periodic endoscopy with biopsy of the ileal mucosa was performed in 90 patients 3-84 months after radical cystectomy and uri nary diversion via an orthotopic neobladder, Three cold-cup biopsies w ere taken from each patient and mucosal specimens processed for light and electronic microscopy.Results Early changes (up to 1 year after su rgery) comprised a marked shortening of the villi with loss of microvi lli, After 4 years, the prevalent finding was of flat, avillous epithe lium that tended to stratify in some areas, The avillous areas were mi xed with islets of villous mucosa. There was no dysplasia or malignanc y in any of the 90 patients. Conclusions Prolonged contact with urine elicited a biphasic response in the ileal mucosa, i.e. an early inflam matory phase, ascribed to the noxious action of urine, followed by a r egressive phase in which the epithelium tended to assume a morphology similar to the urothelium, The atrophic changes were almost totally co mpleted after 4 years, although areas with marked modifications altern ated with others where the morphology was normal, even many pears afte r surgery. Late changes in the ileal neobladder mucosa appear to be an expression of a functional adaptation of the mucosa to the new enviro nment.