[Functional rehabilitation of the urinary bladder after transection of cauda equina]

12 dogs were divided into three groups of L4 root crossover anastomosis S2 root, sacral root free anastomosis and control. All dogs received urodynamic test before and after operation and before sacrifice. The results of cystometry demonstrated the detrusor reflex had returned 7 months after operation in two groups of nerve renovation. The characteristics of axonal regeneration were revealed by immunohisto-cytochemistry and the count of nerve fibres numbers was compared with that by morphometric analysis in proximal and distal end of anastometric stoma. The comparison displayed a significant difference between nerve anastomosis groups and control group. Neural tracing study with horseradish peroxidase (HRP) in two dogs with the operation of L4 crossover S2 showed that lumbar somatic motor axons had regenerated successfully into the bladder and replaced previous sacral parasym-pathetic. Urethral sphincter function was still poor and urethral pressure was not changed post-operatively, though the electromyograme showed some improvement. The method of lumbar root or free sacral root anastomosis with sacral root is practicable for restoration of bladder function.