The structure of the pulmonary circulation in tetralogy of Fallot with pulmonary atresia. A quantitative cineangiographic study.

Unlabelled: Cineangiograms of 172 patients with tetralogy of Fallot and pulmonary atresia were qualitatively and quantitatively analyzed retrospectively.

Findings: Twenty-eight (16%) patients had congenital absence of the central and unbranched hilar portions of the left or right pulmonary artery or both, and thus had congenitally nonconfluent pulmonary arteries. Five additional patients (3%) with originally confluent pulmonary arteries had nonconfluent ones because of an end-to-end surgical shunt, as did seven others (4%) because of thrombosis of one pulmonary artery. Among the 132 patients with confluent right and left pulmonary arteries, 70 (53% of 132) had incomplete arborization (distribution) of one or both, as did 23 (82% of 28) of those with congenitally nonconfluent pulmonary arteries (P for difference = 0.005). Ten (36% of 28) of the latter group had fewer than 10 pulmonary vascular segments (normal is 20) in continuity with central pulmonary arteries, compared with four (3%) of the former group. The proximal left and right pulmonary arteries were small but variable in size in all groups (median value 1.05 McGoon ratio), but were largest in the patients with confluent pulmonary arteries. Seventy-nine (60% of 132) patients with confluent left and right pulmonary arteries had large aortopulmonary collateral arteries, as did 100% of those with congenitally nonconfluent pulmonary arteries (P less than 0.001). The number of large aortopulmonary collateral arteries correlated inversely with the completeness of arborization of the left and right pulmonary arteries (P less than 0.0001). Inferences: Most patients with tetralogy and pulmonary atresia have gross morphologic abnormalities in the pulmonary vasculature and differ quantitatively in this regard from those with tetralogy and pulmonary stenosis. The prevalences of the various types of these abnormalities are considerably interrelated.