The ileal orthotopic neobladder is increasingly becoming a more desirable method of urinary diversion. This transition has been due to the increasing importance of providing patients with a favourable cosmetic outcome and the best quality of life after cystectomy. Bladder control and micturition reflex change after neobladder surgery due to the neobladder replacement and the injury of the peripheral nerve during the operation. In this study, we determine brain responses to micturition, bladder filling and voluntary voiding control using functional magnetic resonance imaging in subjects with ileal orthotopic neobladder.

We performed BOLD-fMRI imaging in seven men undergoing radical cystoprostatectomy and ileal orthotopic bladder substitution, aged 46 to 74 years, postoperative time 10-36 months. Meaningful data were obtained on 5 of these subjects. Brain activity was recorded during micturition, bladder filling and voluntary voiding control.

During micturition, we identified clusters of brain activity in the inferior temporal gyrus, inferior parietal lobule, parahippocampal gyrus, anterior cingulate gyrus, and basal ganglia. There was no activation in the pons region, which was identified in healthy men during urination. During bladder filling, we identified clusters of brain activity in frontal lobe, parietal/occipital region, insula, vermis, thalamus, parahippocampal gyrus, anterior cingulate gyrus, sensory/motor region. During voiding control, we identified clusters of brain activity in precentral gyrus, postcentral gyrus, supplementary motor cortex, inferior frontal gyrus, insula, vermis, thalamus, and cingulate cortex.

There was no activation in the pons region, which was identified in healthy men during urination, probably due to changes in the micturition reflex pathways after surgery. During bladder filling, activation area was conform to that of normal intestine capacity sensory activation area, which may mainly reflect activation of the visceral sensory control area of the ileal neobladder. During voiding control，brain activation was conform to that of healthy subject, mainly reflecting the feeling of neobladder filling and the brain activation area refer to pelvic floor contraction.

In men undergoing radical cystoprostatectomy and ileal orthotopic bladder substitution, no clusters of brain activity of the pontine micturition centre was found during micturition. The clusters of brain activity during bladder filling is conform to normal intestine capacity sensory.