Cavopulmonary anastomosis improves left ventricular assist device support in acute biventricular failure

Right ventricular failure during left ventricular assist device (LVAD) support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavopulmonary anastomosis on right ventricular loading and LVAD performance in a model of severe biventricular failure.

LVAD support was performed by means of centrifugal pump implantation in 14 anesthetized dogs (20-30 kg) with severe biventricular failure obtained by ventricular fibrillation induction. Animals were randomized to be submitted to classical cavopulmonary anastomosis (Glenn shunt) or to control group and were maintained under LVAD support for 2h. Left and right atrial, right ventricular and systemic pressures were monitored, while total pulmonary flow was simultaneously recorded by transonic flowmeters located on the superior vena cava and pulmonary trunk. Blood gas and venous lactate determinations were also obtained.

Ventricular fibrillation maintenance resulted in acute LVAD performance impairment after 90 min in the control group, while animals with Glenn circuit maintained normal LVAD pump flow (55+/-13 ml kg(-1)min(-1) vs 21+/-4 ml kg(-1)min(-1), p<0.001) and better peripheral perfusion (blood lactate of 29+/-10 pg/ml vs 46+/-9 pg/ml, p<0.001). Left and right atrial pressures did not change significantly, while right ventricular pressure was lower in animals with Glenn circuit (13+/-3 mm Hg vs 22+/-8 mm Hg, p=0.005). Right ventricular unloading with Glenn shunt also resulted in superior total pulmonary flow (59+/-13 ml kg(-1)min(-1) vs 17+/-3 ml kg(-1)min(-1), p<0.001).

The concomitant use of cavopulmonary anastomosis during LVAD support in a model of severe biventricular failure limited right ventricular overloading and resulted in better hemodynamic performance.