Erectile function restoration after repair of excised cavernous nerves by autologous vein graft in rats

Abstract

Introduction: Cavernous nerves (CNs) injury is the main cause of erectile dysfunction (ED) following radical prostatectomy. Its restoration remains challenging.

Aim: To investigate the feasibility of erectile function recovery by autologous vein graft after bilateral CNs being excised in a rat model.

Methods: A total of 36 adult male Sprague-Dawley rats were randomized into three groups. A 5mm segment of CN was excised bilaterally in group B and C. In group B, a 7-mm segment of autologous saphenous vein was interposed at the defect site bilaterally, with two nerve stumps inserted into the vein lumen. Group C underwent no repair. Group A was accepted a sham operation. 4 months later, apomorphine tests were performed on each rat, followed by injection of 4% fluorogold into bilateral corpus cavernous. 5 days later, after monitoring intracorporal pressure (ICP) changes induced by electrostimulation of CN, rats were sacrificed and their bilateral major pelvic ganglions were obtained for detection of fluorogold, and penile tissues of middle shaft were obtained for detecting nitric oxide synthase-containing nerve fibers in penile dorsal nerves.

Main outcome measures: Erectile function was assessed by apomorphine test and ICP monitoring. CN regeneration was judged by fluoroglod tracing and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining.

Results: Apomorphine tests resulted in 58% rats with erectile responses in group B, whereas no erection was observed in group C. ICP monitoring also demonstrated a significant recovery in erectile function in group B compared with group C. Much more and brighter fluorogold coloring cells were examined in major pelvic ganglions of group B than those of group C. NADPH-diaphorase staining also showed much more positive fibers were detected in penile dorsal nerves in group B than in group C.

Conclusion: Autologous vein graft could provide a guide channel to induce CN regeneration and successfully restore autonomic erectile function after CNs being excised in rats.