The U.S. Food and Drug Administration approved a new type of heart-pumping device designed by Pleasanton, Calif.-based Thoratec Corp to help advanced-stage heart failure patients survive while awaiting heart transplants.

The HeartMate II Left Ventricular Assist System is just 3 inches in length and weighs about 1 pound. The device can be powered either by battery or while connected to an electrical outlet, as a cable that powers it, passes through the patient’s skin to an external controller.

“The HeartMate II is an important advance in mechanical heart technology. Until now, some heart transplant candidates have been underserved due to the large size of previously approved heart assist devices,” stated Dr. Daniel Schultz, director of the FDA's Center for Devices and Radiological Health, according to the Wall Street Journal.

The HeartMate II is designed to be implanted next to the patient’s heart and then removed after the patient gets a heart transplant. It can pump up to 10 liters of blood per minute – the full output of a healthy heart – Thoratec said in a press release. The device has already been approved in Europe since November 2005.

The approval comes after a clinical study of 126 patients at 26 transplant centers showed that 57 percent of patients with the HeartMate II survived the heart transplant, which is comparable to the survival of patients treated with previously approved heart-assist devices, the FDA said.

The agency also added that the manufacturer will be required to conduct a post-approval study of the device’s performance.