Development of pulmonary arteries after central aortopulmonary shunt in newborns

Background. Central shunt (CS) is frequently used to treat diminished pulmonary blood flow in newborns. We analyzed the impact of CS on the growth of the pulmonary arteries (PAs). Methods. Twenty-two consecutive newborns underwent a CS procedure. In 15 newborns the preoperative angiograms and angiograms taken before undergoing anatomic or hemodynamic correction procedures were analyzed. The patients were divided retrospectively into two groups by the size of the PA in the preoperative angiogram: group I, patients with PAs more than 4 mm (n = 10), group II, PAs 4 mm or less (n = 5). To compare the development of the PAs in the groups, the Nakata index, McGoon ratio, and lower lobe indices were calculated from angiograms. Results. The indices were significantly higher in group I before CS, but no differences was found between the groups before anatomic or hemodynamic correction. The postoperative Nakata indices and the McGoon ratios in the groups were higher when compared with preoperative values (group I, p = 0.037 and p = 0.013; group II, p = 0.043 and p = 0.043, respectively). The significant increase of the lower lobe indices only in group II (p = 0.043) suggests faster growth of the PA in this group. Conclusions. Optimal diameters of the CS promote growth of the PAs, which was confirmed by the increased Nakata and McGoon indices. The benefit in smaller PAs is greater.