title: Middle ear packing: comparison of materials in an animal model of mucosal trauma.
abstract: OBJECTIVE
  To compare absorbable gelatin sponge (AGS) with an injectable esterified hyaluronic acid (EHA) as middle ear packing material after mucosal trauma.
  
  
  METHODS
  Randomized, blinded, and controlled study.
  
  
  METHODS
  Tertiary university-based hospital.
  
  
  METHODS
  Twenty-three guinea pigs underwent middle ear surgery with mucosal trauma performed on both ears and one ear packed with either EHA or AGS. Contralateral ears were used as nonpacked paired controls. Auditory brainstem response (ABR) thresholds were measured preoperatively and repeated at 1, 2, and 6 weeks postoperatively. Macroscopic and microscopic analysis measured inflammatory reaction in each group.
  
  
  RESULTS
  ABR threshold changes from baseline in the EHA and both control groups were minor. Threshold levels were higher in the AGS group compared with the AGS control group. This trend was seen in each frequency tested at each time interval. Macroscopic analysis showed tympanic membrane perforation was rare, effusions were common in the AGS group, mucosal edema was most frequent in the AGS group, and unabsorbed packing was usually detected in the AGS group with little EHA detectable at 6 weeks. Microscopic analysis showed normal mucosal healing in all groups. Two AGS ears demonstrated excessive middle ear packing with exuberant osteoneogenesis.
  
  
  CONCLUSIONS
  Middle ear function and mucosal healing after surgery occurred similarly between the EHA control group and the EHA group. In contrast, the AGS group demonstrated worse hearing and a greater level of osteoneogenesis compared with the AGS control group. These results support EHA as an alternative middle ear packing material in otologic surgery.
authors.affiliation: Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida 33136-1015, USA. mlipan@med.miami.edu
authors.forename: Michael Julian
authors.initials: MJ
authors.lastname: Lipan
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Alava
authors.forename: Ralph
authors.initials: R
authors.lastname: Abi-Hachem
authors.forename: Stephen
authors.initials: S
authors.lastname: Vernon
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Van De Water
authors.forename: Simon I
authors.initials: SI
authors.lastname: Angeli
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D004432:Ear, Middle / Q000293:injuries; D005260:Female; D005781:Gelatin Sponge, Absorbable; D006168:Guinea Pigs; D006490:Hemostatics; D006820:Hyaluronic Acid / Q000008:administration & dosage; D007267:Injections; D023421:Models, Animal; D009092:Mucous Membrane / Q000293:injuries
chemical_list: D001672:Biocompatible Materials; D006490:Hemostatics; D006820:Hyaluronic Acid