title: Assessment of the mechanics of a tissue-engineered rat trachea in an image-processing environment.
abstract: OBJECTIVE
  Despite the recent success regarding the transplantation of tissue-engineered airways, the mechanical properties of these grafts are not well understood. Mechanical assessment of a tissue-engineered airway graft before implantation may be used in the future as a predictor of function. The aim of this preliminary work was to develop a noninvasive image-processing environment for the assessment of airway mechanics.
  
  
  METHODS
  Decellularized, recellularized and normal tracheas (groups DECEL, RECEL, and CONTROL, respectively) immersed in Krebs-Henseleit solution were ventilated by a small-animal ventilator connected to a Fleisch pneumotachograph and two pressure transducers (differential and gauge). A camera connected to a stereomicroscope captured images of the pulsation of the trachea before instillation of saline solution and after instillation of Krebs-Henseleit solution, followed by instillation with Krebs-Henseleit with methacholine 0.1 M (protocols A, K and KMCh, respectively). The data were post-processed with computer software and statistical comparisons between groups and protocols were performed.
  
  
  RESULTS
  There were statistically significant variations in the image measurements of the medial region of the trachea between the groups (two-way analysis of variance [ANOVA], p<0.01) and of the proximal region between the groups and protocols (two-way ANOVA, p<0.01).
  
  
  CONCLUSIONS
  The technique developed in this study is an innovative method for performing a mechanical assessment of engineered tracheal grafts that will enable evaluation of the viscoelastic properties of neo-tracheas prior to transplantation.
authors.affiliation: Biomedical Engineering Laboratory, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Thiago Henrique Gomes da
authors.initials: TH
authors.lastname: Silva
authors.affiliation: Heart Institute (InCor), Thoracic Surgery Research Laboratory (LIM 61), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Rogerio
authors.initials: R
authors.lastname: Pazetti
authors.affiliation: Biomedical Engineering Laboratory, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Fabio Gava
authors.initials: FG
authors.lastname: Aoki
authors.affiliation: Heart Institute (InCor), Thoracic Surgery Research Laboratory (LIM 61), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Paulo Francisco Guerreiro
authors.initials: PF
authors.lastname: Cardoso
authors.affiliation: Biomedical Engineering Laboratory, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo Henrique
authors.initials: MH
authors.lastname: Valenga
authors.affiliation: Tissue Engineering Laboratory, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
authors.forename: Elenice
authors.initials: E
authors.lastname: Deffune
authors.affiliation: Tissue Engineering Laboratory, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
authors.forename: Thaiane
authors.initials: T
authors.lastname: Evaristo
authors.affiliation: Heart Institute (InCor), Thoracic Surgery Research Laboratory (LIM 61), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Paulo Manuel
authors.initials: PM
authors.lastname: Pêgo-Fernandes
authors.affiliation: Biomedical Engineering Laboratory, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Henrique Takachi
authors.initials: HT
authors.lastname: Moriya
mesh_terms: D000818:Animals; D005947:Glucose; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008488:Medical Illustration; D011312:Pressure; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012016:Reference Values; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*; D014132:Trachea / Q000033:anatomy & histology* / Q000637:transplantation*; D014325:Tromethamine; D012122:Ventilators, Mechanical
chemical_list: C074097:Krebs-Henseleit solution; D014325:Tromethamine; D005947:Glucose