FREQUENCY OF SEAL DISRUPTION WITH THE SARNS CENTRIFUGAL PUMP IN POSTCARDIOTOMY CIRCULATORY ASSIST

We have used the Sarns centrifugal pump for uni- or biventricular assi st in 58 patients with postcardiotomy cardiogenic shock. This device u tilizes a spinning impeller pump hat is magnetically coupled to a moto r imparting rotary motion to incoming perfusate. Nine patients (16%) e xperienced 22 device failures, which consisted of a nonvisible disrupt ion of the seal within the pumphead. This allowed fluid to accumulate between the pumphead and the motor necessitating change of the pumphea d. The time to seal disruption was 10-149 h (median 48). Of the 22 sea l disruptions, 18 occurred in 73 left ventricular pumps (25%), and 4 o ccurred in 38 right ventricular pumps (11%) p= 0.015. Left ventricular pumps failed at 10-144 h (median 48), and right ventricular pumps fai led at 48-149 h (median 83) p = 0.02. The Sarns centrifugal pump is de pendable for its intended use of cardiopulmonary perfusion. However, w hen used for postcardiotomy assist, seal disruption should be expected . It occurs sooner and is more common during left ventricular assist. We recommend inspection of the magnet chamber for evidence of seal dis ruption every 12 h with left ventricular assist and every 24 h with ri ght ventricular assist.