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.