Fontan hemodynamics: Importance of pulmonary artery diameter

• Authors: Lakshmi P. Dasi, Georgia Institute of Technology; Resmi Krishnankutty Rema, Georgia Institute of Technology; Hiroumi Kitajima, Emory University; Kerem Pekkan, Georgia Institute of Technology; Kartik S. Sundareswaran, Children's Healthcare of Atlanta; Mark Fogel, Children's Hospital of Philadelphia; Shiva Sharma, Pediatric Cardiology Services; Kevin Whitehead, Children's Hospital of Philadelphia; Kirk Kanter, Emory University; Ajit Yoganathan, Emory University
• Journal Title: Journal of Thoracic and Cardiovascular Surgery
• Volume: Volume 137, Number 3
• Publisher: Elsevier | 2009-03-01, Pages 560-564
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.jtcvs.2008.04.036
• Subjects: Health Sciences, General
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems; Respiratory System; Surgery; Cardiovascular System & Cardiology; TOTAL CAVOPULMONARY CONNECTION; HEPATIC VENOUS-BLOOD; IN-VITRO; LATERAL TUNNEL; EXTRACARDIAC CONDUIT; FLOW; RECONSTRUCTION; GEOMETRY

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. Methods and 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 (R2 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.