title: Addition of a small curvature reduces power losses across total cavopulmonary connections.
abstract: BACKGROUND
  In the Fontan circulation the vis a tergo for lung perfusion is limited. The hypothesis of this in vitro study was that energy dissipation at the common cavopulmonary connection can be reduced by the addition of caval curvature.
  
  
  METHODS
  Two Perspex models were analyzed, the commonly used crosslike cavopulmonary connection (model 1) and a modified curved configuration (model 2). Pressures and flows across the connections were measured simultaneously at various caval and pulmonary artery flow splits and resistances. Mixing of inferior and superior caval fluid was evaluated.
  
  
  RESULTS
  Caval pressure oscillations occurred in model 1 only. Curvature reduced power losses in all settings significantly (alpha = 0.05), most successfully at adult caval flow ratios and at high flow rates. At equal pulmonary resistances pulmonary flow was balanced in both models. The inferior caval fluid is preferably directed to the right lung in model 2 predominantly for caval flow conditions in younger patients.
  
  
  CONCLUSIONS
  Our data show that the modified curved cavopulmonary connection is hydrodynamically advantageous but might impair caval fluid mixing in younger children.
authors.affiliation: Department of Cardiac Surgery, Medical University of Lübeck, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gerdes
authors.forename: J
authors.initials: J
authors.lastname: Kunze
authors.forename: G
authors.initials: G
authors.lastname: Pfister
authors.forename: H H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D000367:Age Factors; D055592:Biophysical Phenomena; D001703:Biophysics; D018610:Heart Bypass, Right / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D008953:Models, Anatomic; D011312:Pressure; D011651:Pulmonary Artery / Q000502:physiology / Q000601:surgery; D012039:Regional Blood Flow; D014682:Vena Cava, Inferior / Q000502:physiology / Q000601:surgery