Re-Innervation of the Bladder through End-to-Side Neurorrhaphy of Autonomic Nerve and Somatic Nerve in Rats

Abstract

End-to-side neurorrhaphy is widely used in the peripheral nervous system for nerve repair; however, the application of this technique has been limited to somatic nerves. The feasibility of nerve regeneration through end-to-side neurorrhaphy between autonomic and somatic nerves with different characteristics in the peripheral nervous system is still undetermined. In this study, rats were divided into three groups for different treatments (n = 10 per group). In the end-to-side neurorrhaphy group, left L6 and S1 were transected in the dura, and the distal stump of L6 ventral root was sutured to the lateral face of L4 ventral root through end-to-side coaptation. In the no repair group, the rats did not undergo neurorrhaphy. In the control group, the left L6 dorsal root and S1 roots were transected, respectively, but the L6 ventral root was kept intact. After 16 weeks, the origin and mechanism of nerve regeneration was evaluated by retrograde double labeling technique as well as histological examination and intravesical pressure measurement. Retrograde double labeling indicated that the reconstructed reflex pathway was successfully established and the primary regeneration mechanism involved axon collateral sprouting. Morphological examination and intravesical pressure measurement indicated prominent nerve regeneration and successful re-innervation of the bladder in the neurorrhaphy group, compared with the ''no repair'' group ( p < 0.05). No significant changes were observed in the histology of the donor nerve and the bilateral extensor digitorum longus muscles in the neurorrhaphy group. Nerve regeneration may be achievable for nerve repair through end-to-side neurorrhaphy between autonomic and somatic nerves without apparent impairment of donor somatic nerve.

Reconstruction of bladder function and prevention of renal deterioration by means of end‐to‐side neurorrhaphy in rats with neurogenic bladder

“…In the same line of experiments, Gao et al found that end‐to‐side neurorrhaphy is an effective procedure for treating NB with limited donor nerve morbidity in rats. However, cystometry was not performed in their experiment, and therefore its exact effect on restoration of bladder function remains unknown.…”

“…The rats were assigned randomly to three groups (Figure ): the end‐to‐side nerve coaptation group (ECG), no nerve coaptation group (NCG), and control group (CG). Rats in the ECG underwent laminectomy from L3 to S1 with modifications as described previously . In brief, following anesthesia induction by 10% chloral hydrate, a dorsal median incision exposed the dorsal and ventral roots of L3‐S1.…”

“…More animal studies have been performed to determine the optimal approach and the efficacy of neurorrhaphy. Recently, Gao et al demonstrated that transection followed by end‐to‐side neurorrhaphy of the left L6 ventral root and left L4 ventral root (VR) can restore bladder innervation without apparent impairment of the donor nerve. Restored bladder innervation was demonstrated through retrograde nerve tracing and electrical stimulation.…”

The effects of FK1706 on nerve regeneration and bladder function recovery following an end-to-side neurorrhaphy in rats

“…Previously we have reported that nerve regeneration and functional recovery could be achieved through ETS neurorrhaphy with preserving the donor nerve function simultaneously. The main regeneration mechanism was that the somatic motor axons grown into autonomic nerve was through axon collateral sprouting only [ 4 , 18 ]. However, the results of nerve regeneration and function rehabilitation after ETS neurorrhaphy were unsatisfactory, which is a key point to the application of this technique in clinic in the future.…”

Experimental research on end-to-side anastomosis of peripheral nerves and effect of FK506 on end-to-side anastomosis

“…The motor end plate degenerates and disappears. Whether the motor end plate can regenerate after its disappearance and nerve regeneration is still controversial (4). Many scholars have found that nerves can regenerate and obtain partial physiological functions through end-to-side anastomosis but many issues remain to be solved on applying nerve end-toside anastomosis to clinic treatment of nerve injury and making it a regular surgical method (5).…”