Histological adaptation of orthotopic ileal neobladder mucose: 4-year follow-up of 30 patients

Objective: For 4 years we have monitored the histological evolution of ilea l neobladders in a single cohort of 30 patients in order to systematically describe the histological changes occurring after surgery. The aim of the s tudy was to evaluate the long-term evolution of many histological parameter s with functional relevance as to the metabolic outcome of the reservoirs. Methods: Ileal samples were collected during surgery and by random biopsies during cystoscopy 6, 12, 18, 24, 36 and 48 months later. At each step qual itative and quantitative assessment of the histological and cytological con ditions of the samples was carried out. Results: Morphological changes deve lop relatively early but the situation tends to level out in about 1 year, The morphological changes are topographically uneven and, although mucosal flattening becomes progressively prevalent, areas with shortened villi pers ist indefinitely, Goblet cells prevail over enterocytes and the secretive p attern shifts towards sialomucins. The overall replication rate decreases i nitially but tends to restore in 1 year. Dysplasia or atrophy were never re corded. Conclusions: The 4-year systematic follow-up revealed a typical his totogical adaptation pattern in the ileal neobladder without signs of dyspl asia. The changes seem to be induced by the aggressive environment and deve lop in the time lag required for functional adaptation of the epithelium. C opyright (C) 1999 S. Karger AG, Basel.