Ventricular Assist Devices
According to the United Network of Organ Sharing (UNOS), as of May 2009, 2700 patients in the United States are waiting to receive a heart transplant. However, only about 2,200 donated hearts are transplanted each year.
Patients who are waiting for a heart donor and transplant are at great risk of dying before a heart becomes available. During this waiting period, the doctor may implant a ventrical assist device (VAD) to keep these patients alive. These high-tech machines help the failing heart pump blood throughout the body, bridging the time until a donor heart becomes available. In some cases, the machine allows the heart to rest and recover so that the VAD can be removed and the patient no longer needs a transplant.
Candidates for this device include transplant-ready patients, those in danger of dying before a donor heart is available and those who do not respond to standard cardiac treatments yet are not transplant candidates. VADs have been placed in patients as young as seven years old and as old as 70. Patients weighing as little as 40 pounds or as much as 345 pounds can be supported by these devices.
The surgeon connects the VAD to the bottom of the heart and the main heart artery (aorta). Blood then flows into the heart and out the aorta by means of a small electrically or pneumatically driven motor that is part of the VAD. In some cases a tube is passed through the patient's skin. The tube connects to a controller and a battery pack that the patient wears or carries. This allows the patient to be fully mobile with the device in place.
VADs are not experimental. They are approved by the U.S. Food and Drug Administration and have been used since the early 1990s. Several thousand have been implanted in patients worldwide.
Cedars-Sinai Medical Center uses several types of VADs including the Thoratec XVE VAD, and the HeartMate II VAD. These allow patients who would otherwise be bedridden while they waited for a donor heart to walk around the hospital, participate in activities and in many cases return to home and work with the device in place.