Methods: 15 patients with heal neobladder underwent endoscopic biopsy
at different postoperative intervals. The specimens were analyzed by e
lectron microscopy in order to evaluate the evolution of the mucosal c
hanges ultrastructurally. Results: No significant change was observed
3 months after the operation. After 6 months, the number and height of
the microvilli were reduced, the cell borders crooked and the termina
l web upset. After 12 months disappearance of the glycocalyx, increase
d lysosomal features, increased activity of the muciparous cells, roun
ded mitochondria and loss of the polarized disposition of the cytoplas
mic organelles were detected in the enterocytes. We observed no other
substantial change after 24 months and more. Conclusions: Progressive
modifications occur in the cytoplasmic structures involved in the abso
rptive process. They do not seem to begin before 3 months and are almo
st totally completed after 1 year.