Right-to-left veno-arterial shunting for right-sided circulatory failure

Background.: Right-sided circulatory failure, a complication of heart transplantation and left ventricular assist device use, results in decreased cardiac output due to diminished flow across the pulmonary circuit. We hypothesized that creation of a controlled right-to-left shunt would result in decompression of the right ventricle and improved systemic cardiac output at tolerable oxygen saturations. We also hypothesized that a peripheral veno-arterial shunt is physiologically superior to a central shunt. Methods.: Right atrial-femoral artery and right atrial-left atrial shunts were created in a large animal model (calf). Right-sided circulatory failure was induced by banding the pulmonary artery. Hemodynamic measures and blood gas determinations were obtained during nonshunted and shunted states. Results.: Peripheral and central shunts resulted in decreased right-sided pressures and increased cardiac output. Arterial oxygen saturation remained greater than 90% during shunting. The peripheral shunt had the added advantage of decreasing left ventricular end-diastolic pressure and left ventricular stroke work. Conclusions.: A controlled right-to-left shunt improved hemodynamics and cardiac output in a large animal model with right-sided circulatory failure. This strategy may be useful in the management of transplant and left ventricular assist device recipients with perioperative right-sided circulatory failure. Our studies also indicate that creation of a peripheral shunt has both physiologic and technical advantages over a central shunt.