title: A pulsatile hemodynamic evaluation of the commercially available bifurcated Y-graft Fontan modification and comparison with the lateral tunnel and extracardiac conduits.
abstract: OBJECTIVE
  Fontan completion, resulting in a total cavopulmonary connection, is accomplished using a lateral tunnel, extracardiac conduit, or bifurcated Y-graft. The use of Y-grafts is hypothesized to provide symmetric hepatic blood flow distribution to the lungs, a factor related to pulmonary arteriovenous malformations. The present study evaluates the hemodynamic performance of the largest commercially available Y-graft cohort to date, highlights 6 representative cases, and compares commercially available Y-graft performance with lateral tunnel/extracardiac conduit connections.
  
  
  METHODS
  A total of 30 patients with commercially available Y-grafts and 30 patients with lateral tunnel/extracardiac conduits were analyzed. Total cavopulmonary connection anatomies and flow waveforms were reconstructed using cardiac magnetic resonance images and phase-contrast cardiac magnetic resonance. Computational fluid dynamic simulations were performed to quantify total cavopulmonary connection power loss, resistance, and hepatic flow distribution. Comparisons between graft types were investigated.
  
  
  RESULTS
  Total cavopulmonary connection resistance was significantly higher for Y-grafts. Hepatic flow distribution was similar overall but showed discrepancies at extreme values with more unbalanced flow in the Y-graft cohort. Power loss was more sensitive to left pulmonary artery stenosis in the Y-graft cohort. Prediction of Y-graft hepatic flow distribution is multifactorial.
  
  
  CONCLUSIONS
  Commercially available Y-grafts do not inherently provide more balanced hepatic flow distribution than lateral tunnel/extracardiac conduit connections, which are more energetically favorable and less sensitive to pulmonary artery stenosis. Graft type should be considered on an individual basis because hemodynamic performance is based on a combination of factors, including pulmonary flow distribution, pulmonary artery stenosis, and superior vena cava positioning.
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Ga.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Trusty
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Ga.
authors.forename: Maria
authors.initials: M
authors.lastname: Restrepo
authors.affiliation: Division of Cardiothoracic Surgery, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Ga.
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Kanter
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Ga. Electronic address: ajit.yoganathan@bme.gatech.edu.
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Yoganathan
authors.affiliation: Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Fogel
authors.affiliation: Division of Cardiology, Department of Pediatrics, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Ga.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Slesnick
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000295:instrumentation* / Q000379:methods; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007223:Infant; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000502:physiology; D014683:Vena Cava, Superior / Q000000981:diagnostic imaging / Q000502:physiology
keywords: Fontan; Y-graft; hepatic flow distribution; single ventricle