Right lung agenesis. A case report.

This report describes a combination of a ventricular septal defect and partial anomalous pulmonary venous drainage in an infant with right lung agenesis. Unilateral agenesis of the lung has been rarely described. Although this condition is compatible with long survival, morbidity and mortality are increased by the associations with other malformations both intra- and extracardiac. In unilateral lung agenesis although there is a compensatory increase in volume of the single lung, there is a reduction in the number of branches of the pulmonary artery and the whole right ventricular output passes through a reduced vascular bed. In isolated unilateral agenesis of the lung, pulmonary hypertension is present in about 19% of cases, while in patients with additional left to right shunt the incidence is 88%. The basic condition of increased pulmonary blood flow (single lung) and the undiagnosed partial anomalous pulmonary venous drainage may explain why the early closure of the ventricular septal defect did not prevent the progressive pulmonary vascular disease. We discuss shortly Tolazoline as pulmonary vasodilator.