Reestablishment of pulmonary-artery flow after prolonged complete occlusion. Studies in dogs.

The ability of the pulmonary vascular bed to accept normal blood flow after prolonged occlusion is important in corrective procedures for tetralogy of Fallot. Preparation of the pulmonary bed by systemic pulmonary shunt prior to complete correction has been considered advantageous by some. Although the final answer to this question will probably come from surgical statistics rather than laboratory experimentation, we thought it would be of interest to study pulmonary blood flow in dogs following reanastomosis of the pulmonary artery after periods of complete occlusion. Methods Direct measurement of left-lung blood flow in dogs weighing in the vicinity of 10 kg (22 lb) was obtained by individual cannulation of the three left pulmonary veins. Measurements were taken during a state of steady flow with mean systemic pressure maintained at 100 mm Hg and the blood volume kept constant by venous infusion of blood equal to that removed for measurement. Total