title: Computational fluid dynamics of the right ventricular outflow tract and of the pulmonary artery: a bench model of flow dynamics.
abstract: OBJECTIVE
  The reconstruction of the right ventricular outflow tract (RVOT) with valved conduits remains a challenge. The reoperation rate at 5 years can be as high as 25% and depends on age, type of conduit, conduit diameter and principal heart malformation. The aim of this study is to provide a bench model with computer fluid dynamics to analyse the haemodynamics of the RVOT, pulmonary artery, its bifurcation, and left and right pulmonary arteries that in the future may serve as a tool for analysis and prediction of outcome following RVOT reconstruction.
  
  
  METHODS
  Pressure, flow and diameter at the RVOT, pulmonary artery, bifurcation of the pulmonary artery, and left and right pulmonary arteries were measured in five normal pigs with a mean weight of 24.6 ± 0.89 kg. Data obtained were used for a 3D computer fluid-dynamics simulation of flow conditions, focusing on the pressure, flow and shear stress profile of the pulmonary trunk to the level of the left and right pulmonary arteries.
  
  
  RESULTS
  Three inlet steady flow profiles were obtained at 0.2, 0.29 and 0.36 m/s that correspond to the flow rates of 1.5, 2.0 and 2.5 l/min flow at the RVOT. The flow velocity profile was constant at the RVOT down to the bifurcation and decreased at the left and right pulmonary arteries. In all three inlet velocity profiles, low sheer stress and low-velocity areas were detected along the left wall of the pulmonary artery, at the pulmonary artery bifurcation and at the ostia of both pulmonary arteries.
  
  
  CONCLUSIONS
  This computed fluid real-time model provides us with a realistic picture of fluid dynamics in the pulmonary tract area. Deep shear stress areas correspond to a turbulent flow profile that is a predictive factor for the development of vessel wall arteriosclerosis. We believe that this bench model may be a useful tool for further evaluation of RVOT pathology following surgical reconstructions.
authors.affiliation: Department of Cardiovascular Surgery, University Hospital Lausanne, Lausanne, Switzerland.
authors.forename: Selim
authors.initials: S
authors.lastname: Mosbahi
authors.affiliation: CFS Engineering, Lausanne, Switzerland.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Mickaily-Huber
authors.affiliation: CFS Engineering, Lausanne, Switzerland.
authors.forename: Dominique
authors.initials: D
authors.lastname: Charbonnier
authors.affiliation: Department of Cardiology, University Hospital Lausanne, Lausanne, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Hullin
authors.affiliation: Department of Surgery and Anesthesiology, Cardiovascular Research, University Hospital Lausanne, Lausanne, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Burki
authors.affiliation: Department of Cardiovascular Surgery, University Hospital Lausanne, Lausanne, Switzerland.
authors.forename: Enrico
authors.initials: E
authors.lastname: Ferrari
authors.affiliation: Department of Surgery and Anesthesiology, Cardiovascular Research, University Hospital Lausanne, Lausanne, Switzerland.
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
authors.affiliation: Department of Cardiovascular Surgery, University Hospital Lausanne, Lausanne, Switzerland denis.berdajs@chuv.ch.
authors.forename: Denis A
authors.initials: DA
authors.lastname: Berdajs
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002405:Catheterization, Central Venous; D002407:Catheterization, Swan-Ganz; D003196:Computer Graphics; D003198:Computer Simulation; D006439:Hemodynamics; D021621:Imaging, Three-Dimensional; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000033:anatomy & histology / Q000503:physiopathology*; D011652:Pulmonary Circulation; D034421:Sus scrofa; D013997:Time Factors; D016278:Ventricular Function, Right
keywords: Computational fluid dynamics modelling; Pulmonary artery; Right ventricular outflow tract