Echocardiographic assessment of pulmonary blood supply in patients with pulmonary atresia and ventricular septal defect

Abstract

The purpose of this study was to determine the role of high resolution two-dimensional echocardiographic imaging and color flow Doppler study in assessing the pulmonary blood supply in patients with pulmonary atresia and ventricular septal defect (VSD). Although echocardiography is a well established technique for assessing central pulmonary arteries in pulmonary atresia VSD and for determining the presence or absence of a patent arterial duct, few data are available on its role in patients whose source of blood supply is from collateral vessels. Forty-two patients aged a few hours to 19 months (mean 29 days) were prospectively assessed by high resolution echocardiography, including color flow Doppler study, during a 4-year period ending in 1994, before any intervention other than intravenous administration of prostaglandins. Angiographic confirmation was available in 29 patients, including 18 (95%) of 19 with aortopulmonary collateral channels. A patent arterial duct was correctly identified as the sole source of pulmonary blood supply in 23 patients, whereas aortopulmonary collateral channels were detected in 19, with one of these having a small patent arterial duct and collateral channels. The patent arterial duct originated from the undersurface of the aorta in 16 (67%) of 24 patients and from the base of the brachiocephalic trunk in 7 (33%) of 24. All patients with a patent ductus as the sole source of pulmonary blood supply had confluent pulmonary arteries. Nonconfluent pulmonary arteries were present in six patients, with all but one having aortopulmonary collateral channels as the sole source of pulmonary flow. Aortopulmonary collateral channels were direct in 17 (89%) of 19 patients, whereas in 2 (11%) of 19, both direct and indirect collateral channels were present. Color flow Doppler study was accurate in determining the presence or absence, the side and the origin of the collateral channels in all patients, with the correct number being determined in 12 (67%) of 18. "Wash-in" to the hilar pulmonary arteries (retrograde color flow) was seen in 12 (92%) of 13 patients with collateral channels and confluent pulmonary arteries. Failure to identify a tiny central pulmonary artery occurred in one patient. High resolution imaging and color flow Doppler study provide good appreciation of the source of pulmonary blood supply in neonates and young infants with pulmonary atresia VSD.