Reinnervation of the rectum with a somatic nerve: a canine study

The purpose of this communication was to evaluate the possibility of rectal stimulation through nerve autografting. Eleven mongrel dogs were studied. The abdomen was opened under anesthesia. The obturator nerve was cut at its entrance into the obturator foramen and was embedded in a tunnel within the musculature of the rectal wall. Six months later, the abdomen was re-opened and bilateral pelvic ganglionectomy was done to denervate the rectum. As the urinary bladder was also denervated subsequent to the pelvic ganglionectomy, cystostomy was performed. Two bipolar electrodes were applied to the obturator nerve. The effects of electrostimulation were evaluated under basic conditions after urecholine and atropine administration and after xylocaine topical application to the obturator nerve. After bilateral pelvic neurectomy, the basic rectal pressure dropped (P < 0.05) and there was no response to urecholine or to atropine injection. Obturator nerve electrostimulation induced evoked potentials within the nerve as well as rectal pressure rise (P < 0.001); the former was abolished with xylocaine topical application to the nerve and the latter with atropine administration. Microscopic examination revealed that the Schwann cells and axons grew in the connective tissue between the rectal muscle bundles. In conclusion, reinnervation of the denervated rectum using a somatic nerve implant is possible. To our knowledge this study is the first to show "smooth' muscle excitability by stimulation of a somatic nerve implant.