title: Norwood with right ventricle-to-pulmonary artery conduit is more effective than Norwood with Blalock-Taussig shunt for hypoplastic left heart syndrome: mathematic modeling of hemodynamics.
abstract: OBJECTIVE
  The introduction of right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure for hypoplastic left heart syndrome resulted in a higher survival rate in many centers. A higher diastolic aortic pressure and a higher mean coronary perfusion pressure were suggested as the hemodynamic advantage of this source of pulmonary blood flow. The main objective of this study was the comparison of two models of Norwood physiology with different types of pulmonary blood flow sources and their hemodynamics.
  
  
  METHODS
  Based on anatomic details obtained from echocardiographic assessment and angiographic studies, two three-dimensional computer models of post-Norwood physiology were developed. The finite-element method was applied for computational hemodynamic simulations. Norwood physiology with RV-PA 5-mm conduit and Blalock-Taussig shunt (BTS) 3.5-mm shunt were compared. Right ventricle work, wall stress, flow velocity, shear rate stress, energy loss and turbulence eddy dissipation were analyzed in both models.
  
  
  RESULTS
  The total work of the right ventricle after Norwood procedure with the 5-mm RV-PA conduit was lower in comparison to the 3.5-mm BTS while establishing an identical systemic blood flow. The Qp/Qs ratio was higher in the BTS group.
  
  
  CONCLUSIONS
  Hemodynamic performance after Norwood with the RV-PA conduit is more effective than after Norwood with BTS. Computer simulations of complicated hemodynamics after the Norwood procedure could be helpful in establishing optimal post-Norwood physiology.
authors.affiliation: Department of Pediatric Cardiac Surgery, Jagiellonian University, Krakow, Poland. t_mroczek@hotmail.com
authors.forename: Tomasz
authors.initials: T
authors.lastname: Mroczek
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Małota
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Wójcik
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Nawrat
authors.forename: Janusz
authors.initials: J
authors.lastname: Skalski
mesh_terms: D058366:Blalock-Taussig Procedure / Q000379:methods*; D001794:Blood Pressure / Q000502:physiology; D003198:Computer Simulation; D015150:Echocardiography, Doppler; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007231:Infant, Newborn; D008955:Models, Cardiovascular; D058327:Norwood Procedures / Q000379:methods*; D011184:Postoperative Period; D011651:Pulmonary Artery / Q000601:surgery; D013314:Stress, Mechanical