Lung Transplantation and Pulmonary Arteriolar Circulation

Abstract

The pathophysiological basis of the increase in pulmonary vascular resistance associated to lung transplantation has not been indisputably clarified. The purpose of the present work was to study the effect of lung transplantation on the pulmonary circulation at the ar-teriolar level. Autotransplantation of the left lung was performed on 9 mongrel dogs. Pulmonary arteriolar pulsation was measured by cinédensitography before and after autotransplantation. The aortic, pulmonary arterial and venous and left atrial pressures, as well as ECG, were recorded simultaneously. A comparison was made between the simultaneous arteriolar pulsation curves of the transplanted left and intact right lungs. The operation produced a fall in the aortic and pulmonary arterial pressures and an increase in the pulse rate due to blood loss during the operation, but no notable pressure gradients in pulmonary arterial or venous anastomoses. The autotransplantation caused a slight, but not significant, decrease in the arteriolar pulsation of the transplanted lung as compared with the intact contra-lateral lung. It was, therefore, concluded that the increase in pulmonary vascular resistance observed in earlier investigations could not be explained on the basis of an impaired distensibility of the pulmonary arterioles.