Functional Restoration of Erectile Function Using End-to-side Autonomic-to-somatic Neurorrhaphy in Rats

Erectile Functional Restoration With Genital Branch of Genitofemoral Nerve to Pelvic Nerve Transfer After Spinal Root Transection in Rats

OBJECTIVE

To investigate the feasibility of erectile function restoration by the genitofemoral nerve to pelvic nerve transfer in rats.

METHODS

Thirty-six male rats were included in this study. Rats in the nerve transfer group (n = 12) were subjected to pelvic nerve, sacral roots, and L6 roots transection and then bilateral genitofemoral nerve to pelvic nerve transfer, rats in the nerve resection group (n = 12) were subjected to pelvic nerve, sacral roots, and L6 roots transection without nerve transfer, and rats in the control group (n = 12) served as controls. After reinnervation, intracavernous pressure (ICP) assessment was performed. Fluoro-Gold was injected into the corpus cavernosum. Immediately before euthanasia, transferred nerves were stimulated to test penile intracavernous pressure. The L6, S1, and L1-2 spinal cord segments were used for retrogradely labeled neurons. Regenerative nerve morphologic examination assessment was performed.

RESULTS

Genitofemoral nerve stimulation induced an increase in ICP in the nerve transfer group. The mean ICP in this group was (33.8 ± 9.4 mm Hg), which is higher than the mean value in the nerve resection group (3.9 ± 1.0 mm Hg) but lower than that in the control group (69.8 ± 12.2 mm Hg; P < .05). The formation of new neural pathways was confirmed by the appearance of Fluoro-Gold labeled neurons in the L-1 and L-2 spinal cord segments in the nerve transfer group. Regenerative nerve morphologic examination showed good axonal regeneration after genitofemoral nerve transfer.

CONCLUSION

Nerve regeneration can be obtained by genitofemoral nerve to pelvic nerve transfer, and erectile function can be restored.

End-to-side Somatic-to-autonomic Nerve Grafting to Restore Erectile Function and Improve Quality of Life After Radical Prostatectomy

BACKGROUND

Radical prostatectomy (RP) is recommended for the treatment of men with clinically localised prostate cancer. However, RP is associated with a high incidence of erectile dysfunction (ED), which can impact the quality of life (QoL) significantly.

OBJECTIVE

To evaluate the effectiveness of end-to-side nerve grafting surgery to restore erectile function and improve sexual QoL in men with ED after RP.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review of a single-centre experience of nerve grafting in men with ED following RP was performed. Seventeen men had surgery between March 2015 and October 2017 in Melbourne, Australia, which fulfilled study inclusion and exclusion criteria.

INTERVENTION

Microsurgical bilateral end-to-side nerve grafts from a selective fascicular neurotomy of the femoral nerve to the penile corpora cavernosa.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Results were serially measured utilising the International Index of Erectile Function (IIEF-5) and the sexual domain of Expanded Prostate Cancer Index Composite (EPIC-26). The proportion and 95% confidence interval (CI) of men recovering sexual function following nerve grafting were determined.

RESULTS AND LIMITATIONS

All patients had ED following their RP. Median age at nerve grafting was 64yr (interquartile range [IQR] 60-66yr). Median time between nerve- and non-nerve-sparing RP, and nerve grafting was 2.4 (IQR 2.1-3.1) and 2.2 (IQR 1.7-5.1)yr, respectively. Median follow-up was 18 (IQR 15-24) mo. At 12mo after nerve grafting, 71% (95% CI 44-90%) of patients had erectile function recovery sufficient for satisfactory sexual intercourse, and 94% (95% CI 71-99%) and 82% (95% CI 57-96%) had clinically significant improvements in sexual function and reduced bother, respectively. There were two minor wound infections. Limitations include the retrospective study design.

CONCLUSIONS

End-to-side nerve grafting restored erectile function in 71% of men with ED following RP, supporting previous findings. Of the men, 94% had clinically relevant improvements in sexual QoL. We recommend multicentre implementation of post-RP nerve grafting into clinical practice with appropriate data collection to confirm its efficacy and feasibility.

PATIENT SUMMARY

We provide confirmatory evidence that end-to-side nerve grafting surgery restored erectile function and improved sexual quality of life in, respectively, 71% and 94% of men with erectile dysfunction following radical prostatectomy.

Reinnervation of the rectum with transfer of the genital branch of the genitofemoral nerve to the pelvic nerve in rats

OBJECTIVE

The purpose of this study was to determine the feasibility of rectum reinnervation with transfer of a primarily genitofemoral nerve to the pelvic nerve in the rat.

METHODS

Thirty-six male rats were randomly divided into 3 groups: rats in the nerve transfer group (n = 12) were subjected to rectal denervation and then bilateral genitofemoral nerve–pelvic nerve transfer; rats in the nerve resection group (n = 12) underwent rectum denervation without nerve transfer; and rats in the control group (n = 12) underwent sham surgery. Rectum denervation was achieved by transection of the L-6 spinal nerves, the spinal nerves below L-6, and the pelvic nerve. Four months postoperatively, retrograde nerve tracing, regenerative nerve morphological examination, and rectal manometry assessment were performed.

RESULTS

Regenerative nerve morphological examination showed good axonal regeneration after genitofemoral nerve transfer. Nerve stimulation induced increased rectal pressures in 10 of 12 rats in the nerve transfer group. The mean rectal pressure in this group was 54.9 ± 7.1 mm Hg, which is higher than the mean value in the nerve resection group (5.5 ± 2.0 mm Hg) but lower than that in the control group (70.6 ± 8.5 mm Hg) (p < 0.05). The appearance of FluoroGold-labeled neurons in the L-1 and L-2 spinal cord segments in the nerve transfer group confirmed the formation of new neural pathways.

CONCLUSIONS

The results have demonstrated that genitofemoral nerve–pelvic nerve transfer can achieve nerve regeneration. In this animal model, the authors were able to reinnervate the rectum by nerve transfer.