[Unilateral agenesis of the main branch of the pulmonary artery].

We studied ten patients with unilateral absence of main branch of pulmonary artery (UAMBPA). Six patients with absent right pulmonary artery (ARPA) and four with the left pulmonary artery (ALPA). The presence of either atrial septal defect, ventricular septal defect and patent ductus arteriosus alone or combinated were associated with pulmonary hypertension (mean pressure of the pulmonary artery greater than 48 mm Hg). The patients without associated cardiac defects were asymptomatic and with little elevation of the pulmonary arterial pressure (mean pressure of the pulmonary artery less than 26 mmHg).