title: Is the pelviureteric junction an anatomical entity?
abstract: OBJECTIVE
  The concept of the pelviureteric junction has existed for more than a century and yet there is no clear anatomical definition of this junction. This systematic review addresses the question of whether the human pelviureteric junction is a discrete anatomical entity.
  
  
  METHODS
  A systematic literature review was undertaken to investigate the normal gross and microscopic anatomy of the pelviureteric junction using the electronic databases MEDLINE, PubMed, Cochrane Library and Google Scholar.
  
  
  RESULTS
  In most individuals there is a gradual transition between the renal pelvis and ureter with no external features indicating the presence of a discrete pelviureteric 'junction'. Internally, however, luminal mucosal folds are prominent in this region. There is no consensus on the arrangement of muscle fibers at the pelviureteric junction (which may be age-dependent) although some studies suggest a focal thickening in the muscle wall consistent with physiological observations suggesting a high pressure zone capable of regulating urine flow. Studies of innervation have shown no evidence of specialization at this site.
  
  
  CONCLUSIONS
  There is some evidence that a pelviureteric region can be delineated anatomically and physiologically. However, although it may be a useful clinical concept, there is no sound anatomical basis for an actual pelviureteric junction.
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, University of Otago, PO Box 913, Dunedin, New Zealand. mark.stringer@anatomy.otago.ac.nz
authors.forename: Mark D
authors.initials: MD
authors.lastname: Stringer
authors.forename: Shahed
authors.initials: S
authors.lastname: Yassaie
mesh_terms: D002648:Child; D006801:Humans; D006869:Hydronephrosis / Q000473:pathology* / Q000503:physiopathology; D007682:Kidney Pelvis / Q000033:anatomy & histology* / Q000294:innervation / Q000502:physiology; D014513:Ureter / Q000033:anatomy & histology* / Q000294:innervation / Q000502:physiology