title: Evaluation of esterified hyaluronic acid as middle ear-packing material.
abstract: OBJECTIVE
  To evaluate the efficacy of esterified hyaluronic acid (MeroGel) as a middle ear (ME)-packing material.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Twenty-four guinea pigs.
  
  
  METHODS
  Group 1, MeroGel-treated animals (n = 10), bilateral wounding of ME mucosa with 5 of the animals receiving the MeroGel packing in the left ME and 5 of the animals receiving MeroGel in the right ME; group 2, absorbable gelatin sponge-treated animals (n = 10), with the same experimental protocol as in group 1 except that the absorbable gelatin sponge was the packing material; group 3, untreated animals (n = 4), unilateral wounding of the left ME mucosa in 2 animals and in 2 animals in the right ME, with no packing material. Auditory brainstem recordings were performed for all groups before the ME operation and 5 days and 6 weeks after the operation.
  
  
  RESULTS
  Auditory brainstem response recordings at postoperative day 5 showed that all ears with ME packing had hearing losses in the frequency range of 500 to 4000 Hz. The recovery of hearing acuity at postoperative week 6 was significantly better in group 1 (MeroGel-treated) guinea pigs compared with group 2 (the absorbable gelatin sponge-treated) animals. In group 2 animals, 20% of the packing material remained in the ME cavities and new bone formation was observed, while in group 1 animals, there was less packing material in the ME and no formation of new bone.
  
  
  CONCLUSIONS
  MeroGel is a nonototoxic packing material with a high level of biocompatibility for ME mucosa; it is an effective supportive material following ME surgery and is easily expelled from the ME cavity.
authors.affiliation: Department of Otolaryngology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: G
authors.initials: G
authors.lastname: Li
authors.forename: J G
authors.initials: JG
authors.lastname: Feghali
authors.forename: E
authors.initials: E
authors.lastname: Dinces
authors.forename: J
authors.initials: J
authors.lastname: McElveen
authors.forename: T R
authors.initials: TR
authors.lastname: van de Water
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000493:pharmacokinetics* / Q000633:toxicity; D004432:Ear, Middle / Q000187:drug effects* / Q000293:injuries / Q000601:surgery; D004951:Esterification; D005781:Gelatin Sponge, Absorbable; D006168:Guinea Pigs; D006309:Hearing / Q000187:drug effects; D006820:Hyaluronic Acid / Q000494:pharmacology* / Q000633:toxicity; D009092:Mucous Membrane / Q000187:drug effects; D011897:Random Allocation; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D001672:Biocompatible Materials; D006820:Hyaluronic Acid