title: The anatomy and embryology of posterior urethral valves.
abstract: OBJECTIVE
  We reviewed the literature to better elucidate the history behind our understanding of the anatomy, classification and embryology of posterior urethral valves.
  
  
  METHODS
  A directed MEDLINE literature review of the anatomy, classification and embryology of posterior urethral valves was performed. An effort was made to focus on the most frequently cited historical articles as well as those including detailed anatomical analyses of fetal specimens. Also included was the analysis of a specimen obtained at our institution in a novel manner that to our knowledge has not been previously described in the literature with respect to the anatomy of posterior urethral valves.
  
  
  RESULTS
  The precise origins regarding the anatomy and embryology of posterior urethral valves remain undefined. However, the literature is abundant in theories regarding the origin of posterior urethral valves, based primarily on small uncontrolled series or case reports. There are a limited number of reports of the anatomy of posterior urethral valves in methodical fashion using reproducible scientific techniques such as histopathology. These reports are invaluable for providing a foundation of how to properly study and define the origins of posterior urethral valves.
  
  
  CONCLUSIONS
  Elucidating this most fundamental feature of a congenital condition central to the practice of pediatric urology is essential. More well designed studies specifically with this goal in mind are necessary. Incorporating new reconstructive imaging modalities may assist us in pinpointing the elusive origins of the embryology and anatomy of posterior urethral valves.
authors.affiliation: Department of Urology, University of California-San Francisco Children's Medical Center, University of California, San Francisco, California, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Krishnan
authors.forename: Antonio
authors.initials: A
authors.lastname: de Souza
authors.forename: Rama
authors.initials: R
authors.lastname: Konijeti
authors.forename: Laurence S
authors.initials: LS
authors.lastname: Baskin
mesh_terms: D006801:Humans; D008297:Male; D014521:Urethra / Q000002:abnormalities* / Q000033:anatomy & histology / Q000196:embryology