Hypoxia and hydrothoraces in a case of liver cirrhosis: Correlation of physiological, radiographic, scintigraphic, and pathological findings

Abstract

A case is reported of liver cirrhosis complicated by cyanosis and recurrent right hydrothorax. A diagnostic pneumoperitoneum demonstrated that direct movement of ascites through a diaphragmatic defect was responsible for the hydrothoraces. Pulmonary function tests between episodes of hydrothorax showed severe arterial hypoxemia, a 23% right-to-left shunt, and a reduction in the carbon monoxide transfer factor to less than half of the predicted value. Evidence of abnormal intrapulmonary arteriovenous communications was obtained by perfusions scanning. At necropsy the central tendon of the diaphragm showed numerous areas of thinning which were easily ruptured. Injection of the pulmonary arterial tree demonstrated precapillary arteriovenous anastomoses and pleural spider naevi. A morphometric analysis provided quantitative evidence of pulmonary vasodilatation limited to the intra-acinar arteries, consistent with the effct of a circulating vasodilator. The scintigraphic and pathological findings suggested that shunting had been greater in the right than the left lung. Examination of thin lung sections by light microscopy showed that the walls of small veins were thickened, and electron microscopy showed that this was due to a layer of collagen. The walls of capillaries were similarly thickened, which caused an approximately two-fold increase in the minimum blood-gas distance and contributed to the reduction in transfer factor.