An Implantable Blood Pump for Adult Congenital Heart Disease Patients with a Failed Fontan Circulation

Project: Research project

Project Details

Description

For children born with cardiac malformations resulting in a single functional ventricle, the Fontan operation has provided palliation such that children are increasingly surviving into adulthood. The Fontan circulation allows systemic venous blood to bypass the pulmonary ventricle and flow directly into the pulmonary arteries, and utilizes the functioning single ventricle only to provide the systemic (left-sided) cardiac output. Due to improvements in operative procedures, timing, staging, and management, early mortality is now less than 5% and survival at 20 years is 85%. However, morbidity is significant due to venous congestion and elevated pulmonary vascular resistance, progressive ventricular dysfunction, dysrhythmias, hypoxemia, and protein-losing enteropathy.

As more patients with Fontan palliation grow into adulthood, there is an increasing need for means to support patients with failing Fontan physiology. Heart transplantation is currently the only viable option, but the morbidity of the failing Fontan makes these patients suboptimal candidates for heart transplantation, and competition for available donor organs remains a limitation.

The left ventricular assist device (LVAD) continues to expand in use for bridge-to-transplant and long-term destination therapy for isolated left heart failure. However, these devices are not suitable for Fontan support because of the anatomy of the total cavopulmonary connection, as well as concerns with off-design point operation of LVADs into the lower right-sided outlet pressure. There is currently no long-term mechanical support device for this patient population.

A number of catheter-based pumps are being developed for placement in or near the total cavopulmonary connection, but these are intended to provide only short-term support since they require a catheter drive cable exiting through the femoral or jugular vein.

Our group is proposing a permanently implantable device for chronic support. Based on prior work at Penn State with systems for long-term mechanical support in adults and pediatrics, we are proposing a novel pump, called the Fontan Circulation Assist Device (FCAD), designed specifically for the anatomic and hemodynamic requirements of the right-sided circulation. The FCAD is based on a Tesla viscous pump. The FCAD has two opposing inlet ports for the superior and inferior cavae and two outlet ports for the left and right pulmonary arteries. Prototypes have been designed, built, and tested. A reduced size pump has also been designed.

Specific Aim 1: Miniaturize and optimize the FCAD with the goals of minimizing hemolysis, thrombosis, pump size, and power consumption. Computational fluid dynamics will be used to evaluate the effect of key design variables on performance, and velocity results will be validated using experimental fluid dynamics. Candidate designs will be built and tested in vitro and in vivo to validate computational results.

Specific Aim 2: Validate the biocompatibility of pump designs in vivo in the sheep model. Thirty-day chronic studies will be used. The primary objective is to assess thrombosis potential, through measurement of coagulation parameters and platelet activation, pump surface analysis, and necropsy.

Specific Aim 3: Perform limited reliability assessment with initial in vitro reliability testing of the FCAD pump. The long-term objective of this research is to incorporate the FCAD pump into a wireless, fully implantable system, based on technology our group has previously developed for a fully implantable LVAD and total artificial heart. The FCAD system has the potential to normalize the right-sided circulation and provide a vastly improved quality of life in patients with a failing Fontan.

StatusFinished
Effective start/end date9/15/169/14/19

Funding

  • Congressionally Directed Medical Research Programs: $2,760,035.00

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