title: Reinnervation of urethral and anal sphincters with femoral motor nerve to pudendal nerve transfer.
abstract: OBJECTIVE
  Lower motor neuron damage to sacral roots or nerves can result in incontinence and a flaccid urinary bladder. We showed bladder reinnervation after transfer of coccygeal to sacral ventral roots, and genitofemoral nerves (L1, 2 origin) to pelvic nerves. This study assesses the feasibility of urethral and anal sphincter reinnervation using transfer of motor branches of the femoral nerve (L2-4 origin) to pudendal nerves (S1, 2 origin) that innervate the urethral and anal sphincters in a canine model.
  
  
  METHODS
  Sacral ventral roots were selected by their ability to stimulate bladder, urethral sphincter, and anal sphincter contraction and transected. Bilaterally, branches of the femoral nerve, specifically, nervus saphenous pars muscularis [Evans HE. Miller's anatomy of the dog. Philadelphia: W.B. Saunders; 1993], were transferred and end-to-end anastomosed to transected pudendal nerve branches in the perineum, then enclosed in unipolar nerve cuff electrodes with leads to implanted RF micro-stimulators.
  
  
  RESULTS
  Nerve stimulation induced increased anal and urethral sphincter pressures in five of six transferred nerves. Retrograde neurotracing from the bladder, urethral sphincter, and anal sphincter using fluorogold, fast blue, and fluororuby, demonstrated urethral and anal sphincter labeled neurons in L2-4 cord segments (but not S1-3) in nerve transfer canines, consistent with reinnervation by the transferred femoral nerve motor branches. Controls had labeled neurons only in S1-3 segments. Postmortem DiI and DiO labeling confirmed axonal regrowth across the nerve repair site.
  
  
  CONCLUSIONS
  These results show spinal cord reinnervation of urethral and anal sphincter targets after sacral ventral root transection and femoral nerve transfer (NT) to the denervated pudendal nerve. These surgical procedures may allow patients to regain continence.
authors.affiliation: Department of Urology, Temple University, Pennsylvania, USA. rugg@temple.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ruggieri
authors.forename: Alan S
authors.initials: AS
authors.lastname: Braverman
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Bernal
authors.forename: Neil S
authors.initials: NS
authors.lastname: Lamarre
authors.forename: Justin M
authors.initials: JM
authors.lastname: Brown
authors.forename: Mary F
authors.initials: MF
authors.lastname: Barbe
mesh_terms: D001003:Anal Canal / Q000294:innervation* / Q000503:physiopathology; D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D004599:Electric Stimulation Therapy / Q000295:instrumentation; D005240:Feasibility Studies; D005242:Fecal Incontinence / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005267:Femoral Nerve / Q000601:surgery*; D058542:Implantable Neurostimulators; D009416:Nerve Regeneration; D016067:Nerve Transfer; D056347:Neuroanatomical Tract-Tracing Techniques; D011312:Pressure; D060525:Pudendal Nerve / Q000601:surgery*; D013119:Spinal Cord Injuries / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D013127:Spinal Nerves / Q000601:surgery; D013997:Time Factors; D014521:Urethra / Q000294:innervation* / Q000503:physiopathology; D014549:Urinary Incontinence / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D014563:Urodynamics