McGowan Institute for Regenerative Medicine faculty member Peter Wearden, MD, PhD, Director, Pediatric Mechanical Cardiopulmonary Support at the Children's Hospital of Pittsburgh of UPMC, has shared his observations re a study of Sanjiv Gandhi, MD, Surgical Director of the Heart Failure Program at Saint Louis Children's Hospital in Missouri. The article in the Cardiovascular Surgery Supplement of Circulation discusses the findings that the Berlin Heart EXCOR pediatric ventricular assist device is an option for children awaiting heart transplant. The EXCOR is currently in use in Europe, and Dr. Wearden recently assessed the small clinical research study of the device in the U.S. conducted by Dr. Gandhi. "These are fantastic outcomes, better than you see in many other centers," said Dr. Wearden. But, he cautioned, "This is not a complete panacea." There are still risks, and he said that parents often focus on the potential benefits and don't always hear that there can be complications.
The EXCOR is an extra corporeal, pulsatile ventricular assist device, supporting the pumping function of a weakened heart. Extra corporeal means that the actual blood pumps are outside of the patient’s body, connected to the heart via cannulas. Due to the availability of different pumps and cannula sizes, the system is suitable for all patients: adults, children, toddlers, and newborns. Berlin Heart is among a few companies worldwide that offer cardiac assist systems for children. The device was developed mainly for patients whose heart is not strong enough to provide their vital organs with an adequate supply of blood. There are a number of possible reasons for this condition – e.g. cardiomyopathy, a sudden heart attack, acute myocarditis, or, especially in children, following heart surgery.
The system’s main component is the blood pump consisting of transparent polyurethane, thus the blood passing through the pumps can be observed giving medical teams an additional diagnostic option to check. The pump consists of two chambers: one air chamber and one blood chamber. These two chambers are parted by a triple membrane from each other. The chamber which comes in touch with the blood is coated with Heparin (a drug which modifies the coagulation ability). The pump has one inflow and one outflow socket. On one end the cannulas are fastened to these sockets; on the other, they are connected with the heart and the vessels. To ensure that the blood flows in the correct direction the pump is equipped with two hatches that operate as valves.
In Pittsburgh, work continues on the development of a pediatric ventricular heart assist device about the size of a quarter for infants. The miniature centrifugal pump utilizes suspended magnetic levitation technology for use in babies between 5 and 35 pounds. It's conceived that the device could be used for up to 6 months as a bridge to heart transplantation. In some babies, the device may allow the heart to recover. As such, Dr. Wearden and the research team plan to develop a smart control system that will indicate patterns consistent with a recovering heart. Since the device will be fully implantable with a small lead to an external power supply, children supported by the device will be able to be mobile and active.
Dr. Wearden is also an Assistant Professor of Cardiothoracic Surgery, University of Pittsburgh School of Medicine.
Illustration: Berlin Heart.
Washington Post (09/29/08)
US News & World Report (09/29/08)
Berlin Heart – EXCOR Pediatric (Children)
Bio: Peter Wearden, MD, PhD
Regenerative Medicine Today – Peter Wearden, MD, PhD
McGowan Institute for Regenerative Medicine In the News: Institute Receives NIH Funding to Develop Heart Assist Device For Infants