Branching patterns of right pulmonary artery in cardiovascular anomalies

The branch of the right pulmonary artery (RPA) to the upper lobe of the right lung (RUL), the truncus anterior of the RPA, and the pars anterior of the left pulmonary artery, which supplies the left upper lung lobe (LUL), were demonstrated by both dissection of postmortem specimens and angiography for 20 infants and children, by angiography only for 57, and by specimen dissection only for 59 (total 136). In posteroanterior angiograms, the RUL artery branches from the RPA near the right lateral border of the vertebral column, while the LUL artery or arteries arise more laterally, near the left midclavicular plane. This pattern is reversed in situs inversus (eight patients studied). Thirty-nine patients in other categories of congenital cardiovascular disease showed an abnormal RUL or LUL arterial pattern, including pulmonary isomerism, right lung type (RUL artery pattern present bilaterally, 12 patients); pulmonary isomerism, left lung type (RUL artery pattern absent bilaterally, 11 patients); scimitar syndrome (RUL artery pattern normal, 1 patient; absent bilaterally, 4 patients); and left pulmonary artery sling (RUL artery normal, one; hypoplastic, one; absent, two patients). Five patients with tetralogy of Fallot (TOF) with right aortic arch (RAA) and 1 of 15 with RAA not TOF or situs inversus showed a relatively large RUL artery arising more laterally than usual. Three of six patients with double outlet right ventricle had the LUL artery larger than usual plus two accessory RUL arteries, and one patient with crossed pulmonary arteries showed a similar pattern. Two patients with single ventricle had an RUL artery of normal pattern although the RUL bronchus was absent, and one patient with single ventricle and situs inversus had a comparable pattern in the left lung. The ease of demonstration of the right and left upper lobe branches of the pulmonary artery by dissection or angiocardiography warrants greater attention to their patterns in patients with congenital cardiovascular disease. Dissociation of upper lobe bronchial and vascular patterns is unusual and may also be of diagnostic value.