title: Cross-linked hydrogel and polyester resorbable ventilation tubes in a Chinchilla model.
abstract: OBJECTIVE
  To determine the resorption rate and biocompatibility characteristics of novel cross-linked hydrogel ventilation tubes and varied formulations of polyester ventilation tubes in a Chinchilla model.
  
  
  METHODS
  Animal Study.
  
  
  METHODS
  Three cross-linked glycosaminoglycan hydrogel ventilation tubes fabricated by cross-linking thiol-modified chondroitin sulfate or thiol-modified carboxymethylated hyaluronic acid, four different polyester ventilation tubes (poly L-lactide [PLA], 50/50 poly D,L-lactide-co-glycolide [PLGA], and silver-impregnated versions of PLA and PLGA tubes) were placed into the tympanic membranes of chinchillas. Commercially available fluoroplastic ventilation tubes were placed in the contralateral ear of each animal to serve as a control. Integrity of the tubes was assessed by weekly otoscopy. Biocompatibility was assessed by auditory brainstem response, by otoscopic and histologic examination of the tympanic membrane at the tube site.
  
  
  RESULTS
  The hydrogel tubes had very short resorption times that expanded and enlarged the myringotomy site. PLGA and silver-coated PLGA tubes maintained their integrity in the tympanic membrane for similar durations of 18.9 ± 6.4 days and 21.0 ± 6.0 days, respectively. The silver-coated PLGA tubes had lower neutrophil and fibrosis scores than PLGA tubes. PLA tubes demonstrated equivalent findings to commercially available nonresorbable tubes with respect to otoscopic findings, auditory brainstem response thresholds, and histologic inflammatory scores.
  
  
  CONCLUSIONS
  Resorbable polyester pressure equalization tubes demonstrate predictable resorption behavior and similar biocompatibility characteristics when compared with nonresorbable tubes. Silver modification may confer some stability to PLGA tubes. Hydrogel tubes have very short resorption times, tend to enlarge the myringotomy site, and show greater inflammatory changes.
authors.affiliation: University of Utah School of Medicine, Division of Otolaryngology–Head and Neck Surgery, Salt Lake City, Utah 84132, USA. pcapark@ihc.com
authors.forename: Albert H
authors.initials: AH
authors.lastname: Park
authors.forename: David
authors.initials: D
authors.lastname: Hoyt
authors.forename: David
authors.initials: D
authors.lastname: Britt
authors.forename: Shane
authors.initials: S
authors.lastname: Chase
authors.forename: Kristina
authors.initials: K
authors.lastname: Tansavatdi
authors.forename: Lisa
authors.initials: L
authors.lastname: Hunter
authors.forename: Lawrence
authors.initials: L
authors.lastname: McGill
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Sheng
authors.forename: Aleksander
authors.initials: A
authors.lastname: Skardal
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Prestwich
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials; D002682:Chinchilla; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008876:Middle Ear Ventilation / Q000295:instrumentation*; D023421:Models, Animal; D011091:Polyesters; D014432:Tympanic Membrane / Q000601:surgery
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate