title: Single dose intratympanic mesna application inhibits propylene glycol induced cholesteatoma formation.
abstract: OBJECTIVE
  Mesna (i.e. sodium 2-mercaptoethanesulfonate; C2H5NaO3S2) has been used in otological surgery such as cholesteatoma dissection and tympanic membrane lateralisation in atelectatic ears. However, this study aimed to investigate its effect on cholesteatoma formation.
  
  
  METHODS
  A total of 20 Wistar rats were divided into two groups of 10 animals. The right and left ears of control animals were treated with saline (saline control group; n = 10 ears) and propylene glycol plus saline (propylene glycol control group; n = 10 ears), respectively. In the mesna group, both ears were treated with propylene glycol plus mesna (n = 20 ears). On days 1, 8 and 15, the saline control group had intratympanic injections of 0.2 ml saline and the propylene glycol control and mesna groups had intratympanic injections of 0.2 ml 100 per cent propylene glycol. On day 22, the propylene glycol control group had a single intratympanic injection of 0.2 ml saline and the mesna group had a single intratympanic injection of 10 per cent mesna. Animals were killed 12 weeks after the last injection and the temporal bones were sent for histopathological evaluation.
  
  
  RESULTS
  The cholesteatoma formation rate was 88 per cent in the propylene glycol control group, but was significantly lower in the mesna group (p = 0.01). There were no significant differences in granulation tissue formation (p = 0.498), cyst formation in the bulla (p = 0.381), fibrosis (p = 0.072) and epithelial hyperplasia (p = 0.081) among experimental groups.
  
  
  CONCLUSIONS
  Intratympanic propylene glycol administration is an effective method of promoting experimental cholesteatoma formation. Administration of a single dose of intratympanic mesna inhibited cholesteatoma formation in an animal model.
authors.affiliation: Department of Otorhinolaryngology,Faculty of Medicine,University of Mersin,Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Ismi
authors.affiliation: Department of Pathology,Faculty of Medicine,University of Mersin,Turkey.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Karabulut
authors.affiliation: Department of Otorhinolaryngology,Faculty of Medicine,University of Mersin,Turkey.
authors.forename: K K
authors.initials: KK
authors.lastname: Bal
authors.affiliation: Department of Otorhinolaryngology,Faculty of Medicine,University of Mersin,Turkey.
authors.forename: Y
authors.initials: Y
authors.lastname: Vayisoglu
authors.affiliation: Department of Otorhinolaryngology,Faculty of Medicine,University of Mersin,Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Unal
mesh_terms: D000818:Animals; D018424:Cholesteatoma, Middle Ear / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D005355:Fibrosis; D006097:Granulation Tissue / Q000473:pathology; D006965:Hyperplasia; D000069555:Injection, Intratympanic; D008297:Male; D015080:Mesna / Q000008:administration & dosage*; D019946:Propylene Glycol; D020011:Protective Agents / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents; D013701:Temporal Bone / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D020011:Protective Agents; D012997:Solvents; D019946:Propylene Glycol; D015080:Mesna
keywords: Cholesteatoma; Mesna; Otitis Media; Propylene Glycol