Development of a Miniaturized, Pediatric Continuous-Flow Total Artificial Heart with a Single Moving Part - Project Summary
Mechanical circulatory support (MCS) is already a standard therapy in adult patients with end-stage heart
failure. In pediatric patients with congenital heart diseases (CHDs), however, no implantable devices are
currently available. Congenital anomalies in pediatric patients can make it difficult to use ventricular assist
devices (VADs) to sustain hemodynamics. While heart transplantation can be an ideal therapy, donor hearts
suitable for small children are very limited. Although total artificial heart (TAH) is an alternative for complex
cardiac anomalies, no pediatric TAHs exist, other than SynCardia's 50cc Total Artificial Heart that is under
investigational device exemption clinical study. This device is smaller than their regular 70cc TAH but is
intended only for patients with a body surface area (BSA) of ≥ 1.2 m2, i.e., that of an average 11-year-old. The
goal of this proposal is to develop a pediatric TAH based on Cleveland Clinic’s continuous-flow TAH (CFTAH),
designed for use in adult patients (R01HL096619). Similar to the adult CFTAH, this pediatric CFTAH (P-
CFTAH) is designed with one motor and one rotating assembly supported by a hydrodynamic bearing; it is
valveless and sensorless and has the ability to produce pulsatile flow, self-balance left and right circulation
without electronic intervention, and control speed automatically. Chronic animal experiments of the adult
CFTAH have demonstrated stable hemodynamics and good biocompatibility for 3 months. It was possible to
reduce the size of this CFTAH to 30% smaller in diameter (3.5 cm) and 30% shorter in the length (4.8 cm) with
1/3 of the total device volume, such that it can be implanted in the chest of most infants whose BSA is ≥ 0.3 m2.
The pump flow range of 1.5-4.5 L/min will support patients weighing up to 50 kg (the average weight of 14-
year-old children). For destination therapy, when the patient grows beyond the requirement of 4.5 L/min, the
P-CFTAH can be replaced by the adult CFTAH, by disconnecting the inflow and outflow ports of the P-CFTAH
from their respective inflow cuffs and outflow grafts and connecting a new adult CFTAH under cardiopulmonary
bypass. The Specific Aims to achieve this goal are: (1) Refine our initial P-CFTAH prototype device for
hydraulic performance and biocompatibility by using validated computational fluid dynamics analysis, and
include new manufacturing improvements, which are also being applied to the adult CFTAH, (2) Perform
intraoperative fitting studies to confirm the smallest patient size and critical dimensions to determine fitting
requirements, (3) Perform in vitro system characterization, hemolysis testing, and endurance testing to verify
that the P-CFTAH meets requirements for system performance, and (4) Perform acute and chronic in vivo
experiments to validate hemodynamic response, the self-regulating mechanical design, system performance,
and biocompatibility. The successful completion of this program will demonstrate the feasibility of this
approach applied to a P-CFTAH and ultimately provide clinicians and pediatric patients with a valuable
treatment option for heart failure.
