title: [Clinical relevance of developmental changes of the endolymphatic sac].
abstract: BACKGROUND
  Outcome of endolymphatic sac shunt surgery crucially depends on endolymphatic sac morphology. The intraoperative finding of a fibrotic sac, e.g., will lead to therapy-failure. Aim of the present study was to determine possible developmental changes in endolymphatic sac morphology which could imply, that a shunt operation should not be undertaken in older age.
  
  
  METHODS
  46 histological temporal bone serial sections were examined. All sections were taken from the "Wittmaack Temporal Bone Collection". All specimens were obtained from patients with morphologically healthy ears, especially without a history of Menière's disease or other kinds of vertigo.
  
  
  RESULTS
  During the fetal period the endolymphatic sac is a wide cavity that is surrounded by immature embryonal connective tissue. In older age this cavity gradually shrinks, leading to stenosis in about 80% of the cases. The endolymphatic duct, however, remains open.
  
  
  CONCLUSIONS
  The increasing fibrosis of the endolymphatic sac is part of the natural involution of the inner ear. It constitutes a natural limitation for the outcome of endolymphatic sac shunt surgery in the elderly.
authors.affiliation: Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde, Universitätsklinikum Hamburg-Eppendorf. ussmueller@uke.uni-hamburg.de
authors.forename: J
authors.initials: J
authors.lastname: Ussmüller
authors.forename: M
authors.initials: M
authors.lastname: Sanchez-Hanke
authors.forename: R
authors.initials: R
authors.lastname: Leuwer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004712:Endolymphatic Sac / Q000473:pathology* / Q000601:surgery; D005260:Female; D005355:Fibrosis; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008575:Meniere Disease / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D011247:Pregnancy; D012016:Reference Values