title: Quantification of ventricular volume load in the context of a bidirectional cavopulmonary shunt: a theoretical treatise.
abstract: BACKGROUND
  Functional univentricular hearts are currently palliated by a staged procedure of which the bidirectional cavopulmonary shunt is usually the second stage. In addition to this stage, a calibrated amount of additional pulmonary blood flow may be preserved to promote pulmonary artery growth and increase the length of the interval preceding the total cavopulmonary connection. However, additional pulmonary blood flow can be deleterious for ventricular functioning and development as it increases functional ventricular volume load.
  
  
  METHODS
  Using the Fick principle we devised a theoretic framework to estimate the ventricular volume loading caused by additional pulmonary and collateral aortopulmonary flow. To use this framework, blood samples need to be taken intraoperatively from the aorta, pulmonary veins, and inferior caval vein to determine oxygen saturations. The oxygen saturation samples have to be taken sequentially with and without additional pulmonary blood flow.
  
  
  RESULTS
  The objective of this paper is to provide a theoretic framework to estimate the ventricular volume loading caused by collateral aortopulmonary flow and additional pulmonary blood flow in the context of a bidirectional cavopulmonary shunt in the staged palliation of univentricular hemodynamics. The formulas have not yet systematically been applied in vivo.
  
  
  CONCLUSIONS
  The added volume loading of the ventricle caused by additional pulmonary blood flow can theoretically be estimated using the newly devised formulas so as to calibrate ventricular volume loading to a desired level intraoperatively.
authors.affiliation: Department of Cardiothoracic Surgery, Centre for Congenital Heart Diseases, University Medical Centre Groningen, Groningen, the Netherlands. t.ebels@thorax.umcg.nl
authors.forename: Tjark
authors.initials: T
authors.lastname: Ebels
authors.forename: Ymkje J
authors.initials: YJ
authors.lastname: van Slooten
authors.forename: Nynke J
authors.initials: NJ
authors.lastname: Elzenga
authors.forename: Tjalling W
authors.initials: TW
authors.lastname: Waterbolk
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D003097:Collateral Circulation / Q000502:physiology; D018729:Fontan Procedure / Q000379:methods*; D006330:Heart Defects, Congenital / Q000503:physiopathology* / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000503:physiopathology* / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D010100:Oxygen / Q000097:blood; D011183:Postoperative Complications / Q000503:physiopathology*; D011651:Pulmonary Artery / Q000503:physiopathology; D014682:Vena Cava, Inferior / Q000503:physiopathology
chemical_list: D010100:Oxygen