Growth of stenotic lesions after balloon angioplasty for pulmonary artery stenosis after arterial switch operation

Little is known about the growth potential of pulmonary stenotic lesions after balloon angioplasty (BA) in patients after the arterial switch operation. The aim of this study was to evaluate the growth potential of pulmonary stenotic lesions after BA and assess the midterm results of BA for pulmonary artery stenosis after the arterial switch operation. Thirty-seven patients who had undergone 52 procedures had repeat catheterization at a median of 43 years (range 1.2 to 9.3 ys) after BA. To adjust growth-related changes in the size of the pulmonary artery, the stenotic diameter was expressed as a percentage of normal (%N). An immediate increase of 63 +/- 45% in the stenotic diameter and a reduction of 51 +/- 33% in the pressure gradient occurred across the stenotic lesions after BA. The right ventricular-aortic systolic pressure ratio decreased from 0.67 +/- 0.24 to 0.51 +/- 0.12 after BA (p0.0001). Compared with immediate data after BA, there was no significant change in the growth-adjusted diameter of the stenotic lesions (68 +/- 26 %N after BA vs 65 +/- 25 %N at follow-up, p = 0.08), and the pressure gradient (16 +/- 13 mm Hg after BA vs 20 +/- 21 mm Hg at follow-up, p = 0.10). The ventricular-aortic systolic pressure ratio also did not change (0.51 +/- 0.12 after BA vs 0.50 +/- 0.21 at follow-up, p = 0.57). Restenosis occurred in 3 of 26 vessels (12%) after successful BA in which the diameter increased50% after BA. Our data suggest that pulmonary stenotic lesions after BA develop with age in growing children after the arterial switch operation, and the efficacy of the BA may be long lasting.