Hemodynamic effect of a low-resistance artificial lung in series with the native lungs of sheep

Background. An artificial lung with 1 to 6 month work life could act as a bridge to transplantation. A pumpless artificial lung has been developed. Methods. The artificial lung was placed in series with the native lungs of adult sheep. Hemodynamics were observed, as the right ventricle generated flow through the device. Through a left thoracotomy, two 20-mm grafts were anastomosed in an end-to-side fashion to the pulmonary artery. The grafts were externalized, and directed flow through the chest wall, to the extracorporeal lung. The animals were recovered, weaned from the ventilator, and when standing, flow was diverted through the device. Results. Five of 7 animals survived 24 hours with 75% to 100% of the cardiac output diverted through the device. All animals were active, with interest in food and water, and able to stand. Conclusions. The right ventricle perfused the artificial lung with 75% to 100% of the cardiac output for 24 hours. This device demonstrates the feasibility of a pumpless pulmonary assist device relying on the right ventricle for perfusion.