title: In VitroUltrasound Measurements of Powered and Unpowered Total Cavopulmonary Connection.
abstract: Three-staged Fontan palliation is performed on children suffering from single ventricle congenital heart disease. The series of surgical procedures reroutes blood from the vena cavae directly to the pulmonary arteries, creating a total cavopulmonary connection (TCPC). A viscous impeller pump (VIP) is currently being developed as a cavopulmonary assist device that can modestly augment cavopulmonary flow, reduce systemic venous pressure, and improve ventricular preload. This study used ultrasound to visualize complex flow patterns in powered and unpoweredin vitromock Fontan circulations. The idealized TCPC was modeled with a silicone mold and blood analog made of water and glycerol that was seeded with 10-μm glass beads. B-mode, color Doppler, and pulsed-wave Doppler images were used to visualize complex flow patterns in the idealized TCPC with (1) no VIP, (2) static VIP, and powered VIP rotation rates of (3) 500 and (4) 2,000 rotations per minute (RPM). Pulsed-wave Doppler data showed higher mean velocities and greater variance in the outlets relative to the larger inlets. The maximum inlet velocity ± SD increased from 10.9 ± 3.53 cm/s with no VIP to 15.9 ± 1.03 when the VIP was rotating at 2,000 RPM. Likewise, the maximum outlet velocity increased from 14.9 ± 11.2 cm/s to 18.9 ± 7.25 cm/s at 2,000 RPM. The faster mean velocities with the VIP rotating suggest that the pump augments cavopulmonary flow. The results of this study suggest that measuring complex flow patterns with ultrasoundin vivocould be used clinically to optimize VIP positioning and rotation rate during and after implantation.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA.
authors.forename: Bp
authors.initials: B
authors.lastname: Iliff
authors.affiliation: School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA.
authors.forename: Aem
authors.initials: A
authors.lastname: Kerlo
authors.affiliation: Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Md
authors.initials: M
authors.lastname: Rodefeld
authors.forename: Cj
authors.initials: C
authors.lastname: Goergen
keywords: Doppler; Fontan; Hemodynamics; Total cavopulmonary connection; Ultrasound