| New implantable device
capable of supporting both ventricles moves to human trial in the
United States The first human trials of an experimental implantable ventricular assist device have begun in 10 U.S. medical centers. The Intracorporeal Ventricular Assist Device, developed by Thoratec Corporation, shows particular clinical promise because it can be used to support the pumping function of one or both ventricles. Just a few years ago, assist devices and their control units and power sources were large, unwieldy bedside machines that required patients to stay in the hospital. As the devices have become smaller and more sophisticated, patients have been able to be far more active and enjoy a significantly better quality of life. The new device consists of a small pump (weight less than 1 pound/ 0.45 kg) that is positioned inside the chest wall and upper abdomen and is connected by a thin, flexible line to a control unit and battery pack that is collectively about the size of a briefcase. The control unit monitors the pump and adjusts pumping rate as needed. Initial human trials have begun based on success in animal studies. Before implantation, cardiologists can decide whether to adapt the pump for support of left or right ventricular function. If needed, two devices can be implanted to support both ventricles. Before the current device was developed, the only assist devices that provided dual-ventricular support were positioned outside the body on the abdominal wall with tubes crossing through the diaphragm to connect with the heart and great vessels. The small size of the experimental device
-- about half that of existing implantable left-ventricular systems
-- makes the implantable pump an option for many smaller patients
whose chest cavities were not able to accommodate the larger size
of the current devices, said Kathy E. Magliato, M.D., principal
investigator at Cedars-Sinai Medical Center, 1 of the 10 U.S. centers
in the clinical trial.
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