[Evaluation of the pulmonary artery and its branches by two-dimensional echocardiography in the tetralogy of Fallot and pulmonary atresia in infants. Angiocardiographic correlation and therapeutic implications].

Twenty-two infants aged 5 days to one year (mean: 3.8 months), consisting of 17 with tetralogy of Fallot and 5 with pulmonary atresia-ventricular septal defect, were prospectively investigated by two dimensional echocardiography (2 D echo) in order to evaluate the severity of the impairment of the pulmonary outflow tract and value of 2 D echo in the preoperative evaluation. Right pulmonary artery (PA), observed by angiography in 20 patients, was correctly recorded and could be measured in all cases (20/20), whereas the left PA was seen in 19 patients (19/20). Pulmonary confluence was recognized in 20/20 cases and its absence in 2 cases. In one patient without pulmonary confluence, a large substituted systemic vessel was mistaken for right PA. Echo established in the 22 patients (100%) the presence (17 cases) or absence (5 cases) of continuity between the right ventricle and the PA. Echo demonstrated 2 out of the 3 stenoses of the branches found by angiography. The internal diameter of PA measured by echo, ranging from 3 to 9 mm, was compared with angiographic measurements. A significant linear correlation was observed for each diameter (ring, trunk and branches) between the two techniques. However, echo slightly under-estimated the angiographic diameters. These results show that 2 D echo is a reliable method to determine the severity of impairment of the pulmonary outflow tract in infants with tetralogy of Fallot. They suggest that is may be used to guide the choice of surgical procedure and is adequate, in selected patients, to carry out a palliative intervention without open surgical procedure.