An Unusual Variant of Pulmonary Arteriovenous Fistula

T HE CLINICAL INTEREST evidenced in recent years in pulmonary arteriovenous fistula results in part from the availability of curative surgical procedures for its treatment. Since over 140 cases of this condition have been reported in recent years, it can no longer be considered rare. In pulmonary arteriovenous fistula a direct communication exists between a large pulmonary artery, on the one hand, and a pulmonary vein on the other. Therefore, pulmonary arterial blood low in oxygen content is delivered without further oxygenation through the fistula to the left atrium. The result of this right-toleft shunt may be cyanosis, clubbing, dyspnea, polycythemia, and the opportunity for paradoxic embolization to the systemic circuit. The brain seems particularly prone to receive such emboli. Pulmonary arteriovenous fistulas range in size from very small, without clinical findings, to very large communications with prominent clinical manifestations. This report presents the case of a patient with an unusual form of pulmonary arteriovenous fistula, namely, direct communication of the right lower pulmonary artery with the left atrium. This anomaly had evidently been responsible for a large right-to-left shunt, as cyanosis had been a prominent clinical sign in this patient who succumbed to a cerebral abscess.