Restoration Of Penile Afferent Pathway Through End-to-side Dorsal Root Neurorrhaphy In Rats

Objective:To study the feasibility of restoration of penile afferent pathway through end-to-side dorsal root(DR)neurorrhaphy in rat.Methods:40 male adult Sprague-Dawley rats were divided into model group(n=20),resection group(n=10)and sham group(n=10).In the model and resection group,the right L6 DR,S1 DR,and the contralateral branch of the dorsal penile nerve were transected.The distal stump of L6 DR in the model group was then anastomosed to the intact L4 DR through end-to-side neurorrhaphy.No anastomosis was done in the resection group.No neural damage was done in the sham group.Four months later,the reconstruction of the afferent pathway was tested by retrograde and transganglionic neural labeling.The reflective erection(RE)was valued by detecting the intracavernous pressure elicited by stimulation of dorsal nerve of penis(DNP).The restoration of L6 DR was further detected by morphological examination,immunofluorescence(IF),and ultrastructure observation.Results:The neural labeling tests indicated the integrity of the entire rebuilt penile afferent pathway.The morphological studies,IF,and ultrastructure observation revealed that the regeneration of L6 axons in the model group was significantly better than that in the resection group yet did not reach the level of the sham group.Rats in the sham group exhibited typical RE following DNP stimulation,while the results in the model and resection group were negative.Conclusion:Our studies demonstrated the feasibility of the end-to-side DR transfer neurorrhaphy to restore the afferent pathway of penile sensation in rats.