Pelvic nerve grafts restore bladder function in denervated rats

Abstract

Background: Autonomic nerve preservation techniques for use during surgery for rectal cancer have improved. Nevertheless, in some patients pelvic nerves must be sacrificed to excise all tumor. For these patients, nerve reconstruction at the time of operation by using nerve grafting would be useful. A rat model of this type of nerve reconstruction is described. Methods: Animals were divided into three groups. In the sham control group, a pelvic exploration was conducted without division of the pelvic nerves. In the nerve ablation group, both pelvic nerves were excised segmentally. In the graft group, both pelvic nerves were excised and genitofemoral nerves were interposed bilaterally. At 2-week intervals postoperatively, animals from each group underwent cystometry under urethane anesthesia and neuronal tracing using fragment C of tetanus toxin for demonstration of axonal transport via regenerated nerves. Results: At 6 weeks postoperatively, 60% of the grafted animals produced rhythmic contractions of the bladder. In neuronal tracing studies at weeks 4 and 6, respectively, 40% and 100% of the nerve-grafted rats had labeled neurons in the sacral parasympathetic nucleus. Conclusions: These findings suggest that pelvic nerve grafting in rats can successfully restore bladder function after surgical injury. Clinical use of pelvic nerve grafting may be indicated for patients whose pelvic nerves must be sacrificed to excise all tumor. (Surgery 1998;123:672-8.)