title: Topographic anatomy of the male perineal structures with special reference to perineal approaches for radical prostatectomy.
abstract: OBJECTIVE
  Although perineal approaches for radical prostatectomy have recently gained renewed attention as excellent methods for minimally invasive surgery, the most commonly used techniques, Belt's and Young's approaches, have inadequacies regarding the topographical relationship between the rectourethral and levator ani muscles.
  
  
  METHODS
  Using macroscopic observations of sagittal slices of 27 male pelvises and smooth muscle immunohistochemical staining of semiserial sections of another eight pelvises, we investigated the topographical anatomy of the perineal structures and their interindividual variations in elderly Japanese men.
  
  
  RESULTS
  The inferomedial edge of the levator ani was located 5-15 mm lateral to the midsagittal plane in an area between the urethra and the rectum. The rectourethral smooth muscle had a superoinferior thickness of 5-10 mm and occupied a space between the right and left levator slings. The levator was adjacent to, or continuous with, the striated anal sphincters. A thick connective tissue septum, composed of smooth muscle, was evident between the rectal smooth muscle and the anal sphincter-levator ani complex.
  
  
  CONCLUSIONS
  Because the connective tissue septum guides the surgeon's finger upwards towards the rectoprostatic space, Belt's approach appears relatively easy; however, rectal injury can sometimes occur if the surgeon loses this guidance. In contrast, if the levator edge is identified as the first step in Young's approach, the rectourethral muscle can be precisely divided, leaving a 3-5-mm margin from the rectum and sphincter-levator complex. Clinical investigations are now required to modify Young's approach based on the present results.
authors.affiliation: Department of Urology, Hiroshima University, Hiroshima, Department of Anatomy, Sapporo Medical University School of Medicine, Sapporo, Japan. matsua@hiroshima-u.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Matsubara
authors.forename: Gen
authors.initials: G
authors.lastname: Murakami
authors.forename: Takashi
authors.initials: T
authors.lastname: Arakawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yasumoto
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Mutaguchi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Akita
authors.forename: Kousuke
authors.initials: K
authors.lastname: Asano
authors.forename: Kouji
authors.initials: K
authors.lastname: Mita
authors.forename: Tsuguru
authors.initials: T
authors.lastname: Usui
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000033:anatomy & histology / Q000601:surgery; D002102:Cadaver; D006801:Humans; D008297:Male; D008953:Models, Anatomic; D010502:Perineum / Q000033:anatomy & histology* / Q000601:surgery; D011468:Prostatectomy / Q000379:methods*