title: Biochemical basis of vocal fold mobilization after microflap surgery in a rabbit model.
abstract: OBJECTIVE
  To investigate phonation-related extracellular matrix (ECM) changes in the vocal fold lamina propria after microflap surgery using an in vivo rabbit phonation model.
  
  
  METHODS
  Prospective animal study.
  
  
  METHODS
  Twenty-four New Zealand White rabbits were used in this study. Quantitative polymerase chain reaction and immunohistochemistry were used to investigate alterations in vocal fold ECM proinflammatory and profibrotic gene, and protein expression from a control group of animals receiving a microflap without phonation and a separate group of animals receiving experimentally induced phonation on postmicroflap days 0, 3, and 7.
  
  
  RESULTS
  IHC demonstrated the highest concentration of CD45 in vocal folds on postoperative day 0. Staining for CD45 was absent by postoperative day 7, with no differences in CD45 staining between groups. Fibronectin gene expression increased significantly on postoperative day 3 in the control and experimentally induced phonation groups, with maximal staining of fibronectin around the microflap incision on postoperative day 7. No alterations in cyclooxygenase-2, interleukin-1β, and transforming growth factor-β1 gene expression were observed between groups.
  
  
  CONCLUSIONS
  Results of the present study revealed an acute inflammatory response in the vocal fold at the time of microflap (day 0) and up to 3 days post-microflap. By post-operative day 3, staining of CD45 positive cells decreased, with essentially no evidence of inflammation by post-operative day 7. With the end of the acute inflammatory response occurring around day 3, these data may provide support for mobilizing tissue after inflammation has subsided and the process of active tissue remodeling has ensued (days 3-7).
  
  
  METHODS
  N/A.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery (, Vanderbilt University, Nashville, Tennessee, U.S.A.
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Mitchell
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kojima
authors.forename: Hongmei
authors.initials: H
authors.lastname: Wu
authors.forename: C Gaelyn
authors.initials: CG
authors.lastname: Garrett
authors.forename: Bernard
authors.initials: B
authors.lastname: Rousseau
mesh_terms: D000818:Animals; D004867:Equipment Design; D005109:Extracellular Matrix / Q000378:metabolism; D015870:Gene Expression; D008866:Microsurgery / Q000295:instrumentation; D023421:Models, Animal; D010699:Phonation; D011817:Rabbits; D013524:Surgical Flaps; D014827:Vocal Cords / Q000502:physiology* / Q000601:surgery*
keywords: Gene expression; immunohistochemistry; microflap; phonomicrosurgery; vocal fold; voice rest; wound healing