A new ventricular assist device (VAD) developed by Symbion, Inc., received its initial biventricular clinical use in a 53-year-old man suffering cardiogenic shock from severe congestive heart failure secondary to cardiomyopathy and a 15-year history of coronary artery disease.The eight-day period of biventricular support on the Symbion devices was satisfactory in spite of two complications probably unrelated to the pump. First, a neurologic deficit was noted after transition from the temporary support pumps to the Symbion pumps, ostensibly from a small air bolus entering the aortic return line. The deficit was deemed mild and reversible, and the patient showed improvement. Secondly, poor renal function secondary to prolonged hypotension associated with cardiac arrest persisted throughout the support period. All other organs, however, were well supported.On the eighth day of support, a dramatic change in hepatic function and neurologic deterioration justified termination of support. At explant of the devices, a kink and an occluding thrombus were found at the inferior port of the right atrial outflow cannula, undoubtedly the cause of the declining hepatic status. Clots were also found adherent to both VAD chambers at the air vents, but no evidence of emboli was found at autopsy.Redesign of the air vent sites and cannulae may be required to improve the Symbion VAD's performance.