title: Neural supply of the male urethral sphincter: comprehensive anatomical review and implications for continence recovery after radical prostatectomy.
abstract: OBJECTIVE
  To review the anatomical facts of urethral sphincter (US) innervation discovered over the last three decades and to determine the implications for continence recovery after radical prostatectomy (RP).
  
  
  METHODS
  Using the PubMed®database, we searched for peer-reviewed articles in English between January 1985 and September 2015, with the following terms: 'urethral sphincter,' 'urethral rhabdosphincter,' 'urinary continence and nerve supply' and 'neuroanatomy and nerve sparing.' The anatomical methodology, number of bodies examined, data, figures, relevant facts and text were analyzed.
  
  
  RESULTS
  Seventeen articles on 254 anatomical subjects were reviewed. Coexisting pathways were described in every article. Dissection, histology, simulation or electron microscopy evidence supported arguments for somatic and autonomic pathways. From the most to the least substantiated, somatic sphincteric fibers were described extra- or intrapelvic as: direct from the distal pudendal nerve (PuN), recurrent from the dorsal nerve of the penis, from the proximal PuN with an intrapelvic course, extrapudendal somatic fibers dispersed among autonomic pelvic fibers. From the pelvic plexus, or from the neurovascular bundles, autonomic fibers to the US have been described in 13 of the reviewed articles, with at least each of the available anatomical methods.
  
  
  CONCLUSIONS
  Because continence depends on a number of factors, it is challenging to delineate the specific impact of periprostatic nerve sparing on continence, but the anatomical data suggest that RP surgeons should steer toward the preservation and protection of these nerves whenever possible.
authors.affiliation: Department of Urology, Icahn School of Medicine at Mount Sinai, New York City, NY, 10029, USA. thomas.bessede@gmail.com.|U1195, Univ. Paris Sud, INSERM, Université Paris-Saclay, 94270, Le Kremlin-Bicetre, France. thomas.bessede@gmail.com.|Department of Urology, Hopitaux Universitaires Paris-Sud, APHP, 94 270, Le Kremlin-Bicetre, France. thomas.bessede@gmail.com.
authors.forename: Thomas
authors.identifier: http://orcid.org/0000-0003-3215-1332
authors.initials: T
authors.lastname: Bessede
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK.|Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Prasanna
authors.initials: P
authors.lastname: Sooriakumaran
authors.affiliation: Division of Urology, Department of Surgery, Faculty of Medicine, Tottori University, Tottori, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takenaka
authors.affiliation: Department of Urology, Icahn School of Medicine at Mount Sinai, New York City, NY, 10029, USA.
authors.forename: Ash
authors.initials: A
authors.lastname: Tewari
mesh_terms: D017776:Autonomic Pathways / Q000033:anatomy & histology*; D006801:Humans; D007001:Hypogastric Plexus / Q000033:anatomy & histology*; D008297:Male; D059351:Organ Sparing Treatments; D011183:Postoperative Complications; D011467:Prostate / Q000033:anatomy & histology*; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000601:surgery*; D060525:Pudendal Nerve / Q000033:anatomy & histology*; D020127:Recovery of Function; D014521:Urethra / Q000294:innervation*; D014549:Urinary Incontinence
keywords: Innervation; Nerve sparing; Prostate; Urinary continence