title: Fontan hemodynamics: importance of pulmonary artery diameter.
abstract: OBJECTIVE
  We quantify the geometric and hemodynamic characteristics of extracardiac and lateral tunnel Fontan surgical options and correlate certain anatomic characteristics with their hemodynamic efficiency and patient cardiac index.
  
  
  RESULTS
  The study was conducted retrospectively on 22 patients undergoing Fontan operations (11 extracardiac and 11 lateral tunnel operations). Total cavopulmonary connection geometric parameters such as vessel areas, curvature, and offsets were quantified using a skeletonization method. Energy loss at the total cavopulmonary connection junction was available from previous in vitro experiments and computational fluid dynamic simulations for 5 and 9 patients, respectively. Cardiac index data were available for all patients. There was no significant difference in the mean and minimum cross-sectional vessel areas of the pulmonary artery between the extracardiac and lateral tunnel groups. The indexed energy dissipation within the total cavopulmonary connection was strongly correlated to minimum cross-sectional area of the pulmonary arteries (R(2) value of 0.90 and P < .0002), whereas all other geometric features, including shape characteristics, had no significant correlation. Finally, cardiac index significantly correlated with the minimum pulmonary artery area (P = .006), suggesting that total cavopulmonary connection energy losses significantly affect resting cardiac output.
  
  
  CONCLUSIONS
  The minimum outlet size of the total cavopulmonary connection (ie, minimum cross section of pulmonary artery) governs the energy loss characteristics of the total cavopulmonary connection more strongly than variations in the shapes corresponding to extracardiac and lateral tunnel configurations. Differences in pulmonary artery sizes must be accounted for when comparing energy losses between extracardiac and lateral tunnel geometries.
authors.affiliation: Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0535, USA.
authors.forename: Lakshmi P
authors.initials: LP
authors.lastname: Dasi
authors.forename: Resmi
authors.initials: R
authors.lastname: Krishnankuttyrema
authors.forename: Hiroumi D
authors.initials: HD
authors.lastname: Kitajima
authors.forename: Kerem
authors.initials: K
authors.lastname: Pekkan
authors.forename: Kartik S
authors.initials: KS
authors.lastname: Sundareswaran
authors.forename: Mark
authors.initials: M
authors.lastname: Fogel
authors.forename: Shiva
authors.initials: S
authors.lastname: Sharma
authors.forename: Kevin
authors.initials: K
authors.lastname: Whitehead
authors.forename: Kirk
authors.initials: K
authors.lastname: Kanter
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Yoganathan
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018729:Fontan Procedure / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D011651:Pulmonary Artery / Q000033:anatomy & histology* / Q000502:physiology* / Q000601:surgery; D012189:Retrospective Studies; D014683:Vena Cava, Superior / Q000601:surgery