Erectile functional restoration with genital branch of genitofemoral nerve to cavernous nerve transfer after bilateral cavernous nerve resection in the rat

Abstract

Objective: To investigate the feasibility of erectile function restoration by genital branch of genitofemoral nerve (GN) to cavernous nerve (CN) transfer in rats.

Materials and methods: Thirty adult (3 months) male Sprague-Dawley rats were divided into 3 groups (n = 10 per group). Rats in sham group underwent sham operation, rats in nerve resection (NR) group underwent bilateral GN and CN resection to make a 2.5-mm gap, and rats in nerve transfer (NT) group underwent nerve anastomosis bilaterally between proximal stump of GN and distal stump of CN after nerve resection.

Results: Three months postoperatively, mating test observed 70% rats with intromission behaviors in NT group but only 10% rats in NR group. Electrostimulating the GN of NT group rats resulted in a significant increase in intracavernous pressure, and the ratio of intracavernous pressure increase to mean arterial pressure in NT group was significantly higher than that in NR group. Seven days after Fluoro-Gold injection into the penile crus, Fluoro-Gold-labeled neurons were found in ventral horn of L1 and L2 in NT group, indicating that a new erectile efferent pathway might be established. Axon counting and ultrastructure observation confirmed axonal regeneration in NT group. Furthermore, NT group had a higher expression of nitric oxide synthase in the dorsal penile nerve than that in NR group.

Conclusion: The results have demonstrated that nerve regeneration can be obtained, and erectile function may be restored after GN to CN nerve transfer in bilateral CN resection rats, which provides an innovative and promising treatment for neurogenic erectile dysfunction.