An experimental study on effect of bladder reflex arc with sensory afferent pathway in the treatment of atonic bladder after spinal cord injury / 中华骨科杂志

ABSTRACT

Objective To establish bladder reflex arc with sensory afferent pathway using SD rats,and evaluate its effect in the treatment of atonic bladder after spinal cord injury.Methods Twenty-four male SD rats were used in the study.For each rat,the right side was the experimental side,and the left side was the control side.In the right side,the L5 ventral root (VR) was anastomosed to S2 VR,and the distal end of S2 dorsal root (DR) was anastomosed to the proximal end of L5 peripheral process of dorsal ganglion.In the left side,no treatment was done.In order to evaluate the validity of the bladder reflex arc,general observation,neuro-electrophysiological test and wheat germ agglutinin horseradish peroxidase (WGA-HRP) method were used before and after the spinal cord destruction between L6 and S2 level at 3 months postoperatively.Results Twenty-one rats survived 3 months after the operation,and anastomotic nerves were separated successfully only in seven rats.Compound action potentials (CAPs) of plexus vesica and compound muscle action potentials (CMAPs) of bladder smooth muscle were found by electrical stimulation in distal end of the anastomotic stoma of the right S2 DR.There was no statistically significant difference in action potential before and after paraplegia.No action potential was detected in control sides after paraplegia.The curves of CAPs and CMAPs in the right side were similar to those in the control side,and the mean maximum amplitude reached respectively 71.9％ and 82.4％ of those in the left side before paraplegia.In addition,WGAHRP labeled cells were observed in L5 anterior horn and posterior horn in the experimental side after WGAHRP injection.Conclusion Reconstruction of bladder reflex arc with sensory afferent pathway can promote axonal regeneration of motor and sensory nerves,and then the regenerated axon could contact with cells in anterior and posterior horn of spinal cord through parasympathetic nerves,ultimately the capability of axoplasmic transportation could be reestablished.Therefore,this method can be used for treating atonic bladder.