title: Effect of topical hyaluronic acid on experimental cholesteatoma.
abstract: OBJECTIVE
  Inflammation and connective tissue hyperplasia are believed to be important etiological factors in cholesteatoma pathogenesis. Previous work has shown that topically applied hyaluronic acid can reduce connective tissue proliferation in healing wounds and accelerate healing of tympanic membrane perforations. This study was undertaken to determine whether the antiproliferative effect of hyaluronic acid may inhibit propylene glycol-induced cholesteatoma in an animal model.
  
  
  METHODS
  A 60% propylene glycol solution was injected bilaterally into the middle ear cavities of 20 adult chinchillas. The control group (N = 10) received propylene glycol alone. In addition to propylene glycol injections, the experimental group (N = 10) received repeated bilateral topical applications of 1.5% hyaluronic acid onto the tympanic membranes. Animals were killed at 4 weeks for gross and light microscopic examination.
  
  
  RESULTS
  Seven control and 10 experimental animals survived the full 1-month study period. At the end of that time, cholesteatoma was found in 71% (10/14) of control ears and 70% (14/20) of experimental ears. Tympanic membrane structure did not differ significantly between groups by light microscopy and, in all animals, cholesteatomas originated by migration of hyperplastic epidermis through the tympanic membrane, as has been observed in previous studies using this animal model.
  
  
  CONCLUSIONS
  Under the conditions of this study, topical hyaluronic acid had no significant effect on cholesteatoma formation.
authors.affiliation: Department of Otolaryngology, University of Texas Southwestern Medical Center, Dallas 75235-9035, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: White
authors.forename: C G
authors.initials: CG
authors.lastname: Wright
authors.forename: K S
authors.initials: KS
authors.lastname: Robinson
authors.forename: W L
authors.initials: WL
authors.lastname: Meyerhoff
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D002455:Cell Division / Q000187:drug effects; D002682:Chinchilla; D018424:Cholesteatoma, Middle Ear / Q000139:chemically induced / Q000517:prevention & control*; D003238:Connective Tissue / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D004817:Epidermis / Q000187:drug effects / Q000473:pathology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D006965:Hyperplasia; D007249:Inflammation; D008297:Male; D019946:Propylene Glycol; D011409:Propylene Glycols / Q000009:adverse effects; D014432:Tympanic Membrane / Q000187:drug effects / Q000473:pathology; D014945:Wound Healing
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D011409:Propylene Glycols; D019946:Propylene Glycol; D006820:Hyaluronic Acid