title: Utility and safety of commercially available injection laryngoplasty materials in a rabbit model.
abstract: OBJECTIVE
  To demonstrate foreign body and chronic inflammatory reaction of commercially available injection materials using the rabbit vocal fold paralysis model.
  
  
  METHODS
  Animal study.
  
  
  METHODS
  The left recurrent laryngeal nerve was identified and divided at the tracheoesophageal groove. Amounts (100 μL) of phosphate-buffered saline (PBS), polyacrylamide hydrogel (Aquamid; Ferrosan A/S, Søborg, Denmark), calcium hydroxyapatite (Radiesse; BioForm Medical Inc., San Mateo, CA), or hyaluronic acid derivative (Rofilan; Rofil Medical International, Breda, Netherlands) were injected into the left vocalis muscle. Six months later, the larynx was harvested. Hematoxylin/eosin and Masson trichrome staining were performed to compare inflammatory and foreign body reactions, granuloma development, and relative vocal fold areas among groups.
  
  
  RESULTS
  Compared with the PBS (control) group, the Aquamid, Radiesse, and Rofilan groups exhibited only mild chronic inflammatory reactions that did not significantly differ among groups, or from controls (P > 0.05). However, the Aquamid and Radiesse groups exhibited moderate foreign body reactions that were significantly greater than those of controls (P < 0.05). No foreign body granuloma formed in any group. All test groups exhibited significant increases in vocal fold areas at 6 months (P < 0.05).
  
  
  CONCLUSIONS
  Although commercially available injection materials induced more foreign body reactions than a control injection of PBS, no foreign body granuloma developed and the augmented vocal fold area was maintained until 6 months after injection.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Il Ha
authors.initials: IH
authors.lastname: Moon
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Ki Nam
authors.initials: KN
authors.lastname: Park
authors.affiliation: Department of Pathology, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon, Korea. Electronic address: lsw0922@schmc.ac.kr.
authors.forename: SeungWon
authors.initials: S
authors.lastname: Lee
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage / Q000633:toxicity; D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000633:toxicity*; D004353:Drug Evaluation, Preclinical; D017886:Durapatite / Q000008:administration & dosage / Q000633:toxicity; D005260:Female; D005549:Foreign-Body Reaction / Q000139:chemically induced; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000633:toxicity; D007249:Inflammation / Q000139:chemically induced; D058753:Laryngoplasty; D008422:Materials Testing; D023421:Models, Animal; D011817:Rabbits; D014827:Vocal Cords / Q000187:drug effects*
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; C016680:polyacrylamide gels; D006820:Hyaluronic Acid; D017886:Durapatite
keywords: Foreign body; Injection laryngoplasty; Vocal fold