Intrasplenic pressure was measured in 12 cases where portal splenography was performed and was raised in all patients. Portopulmonary fistulas could not be demonstrated on portosplenography in any patient. In five cases, the portal vein could not be visualized and a few large colaterals were seen to open into the inferior vena cava. In the remaining cases, portal vein was seen and the intrahepatic pattern was distorted. Chest x-ray films showed mild cardiomegaly with somewhat increased pulmonary vascularity in 13 cases and were normal in the remaining patients. The electrocardiogram was within normal limits in 16, and showed nonspecific ST-T changes in four. Table 1 shows the intracardiac pressures to be normal in all. this
There was marked desaturation of the femoral arterial blood in all, which could not be restored to normal by inhalation of 100 percent oxygen for ten minutes. Pulmonary venous samples were obtained in six and were found to be markedly desaturated. Selective right ventriculography, pulmonary angiography, left ventriculography, aortography, and right superior pulmonary vein angiography revealed no evidence of shunt at atrial, ventricular, or aortopulmonary level in any case. Selective pulmonary angiography revealed two patterns of pulmonary vasculature. The pulmonary vasculature appeared blotchy on main pulmonary angiography (Fig 2) and showed multiple small pulmonary arteriovenous fistulas on selective left or right lower lobe angiography (Fig 3) in 15 cases (type A). In five cases, the pattern of pulmonary vasculature appeared indistinguishable from normal (Fig 4) and no convincing evidence of arteriovenous fistulas could be demonstrated (type B). Peripheral vein contrast studies demonstrated passage of contrast material in the left atrium and left ventricle four to five cycles after its appearance in the right heart chambers (Fig 5). The contrast studies thus suggested right to left intrapulmonary shunting through pulmonary arteriovenous fistulas too small to be observed on selective main pulmonary artery or lobar angiography. Open lung biopsy performed in one patient showed a collection of arterial spaces filled with blood and crowded in certain areas. These probably represent pulmonary arteriovenous fistulas (Fig 6).