GROWTH OF PULMONARY-ARTERY AFTER ARTERIAL SWITCH OPERATION FOR SIMPLETRANSPOSITION OF THE GREAT-ARTERIES

This retrospective study attempts to assess the size and growth patter n of the pulmonary artery about 1 year after neonatal arterial switch operation for simple transposition of the great arteries. Sixty-seven patients underwent cardiac catheterization, including catheterization of the right and left pulmonary arteries, and right ventricular angiog raphy an average of 13.9 months after arterial switch operation. In 34 of these patients pre-operative right ventricular angiocardiograms we re available. The diameter of the main pulmonary artery and that of it s proximal right and left branches were measured. The values were comp ared to those of normal children matched for body surface area, taken from the literature and, for the branch values, related to the degree of branch stenosis and to the corresponding values, measured on pre-op erative angiocardiograms. The cross-section of the main pulmonary arte ry after arterial switch operation with Lecompte manoeuvre becomes ova l. The branches of the pulmonary artery are sometimes underdeveloped a nd this finding is related to branch stenosis. The ratio of the branch gradients is inversely proportional to the growth ratio of both branc hes while the pre- and postoperative Nakata indices are identical. Con clusion The Lecompte manoeuvre induces a flattening of the main pulmon ary artery with concomitant reduction of its cross-sectional area. The re is also frequently trivial or rarely moderate branch pulmonary sten osis which is accompanied by growth retardation of the concerned branc h.