[Treatment of supravalvular pulmonary stenosis after arterial switch operations (ASO)].

The aim of this study was to evaluate the incidence of postoperative pulmonary supravalvular stenosis in patients with d-TGA and to assess the rate of success or failure of balloon angioplasty. Out of 70 patients with d-TGA 67 patients underwent successful arterial switch operation. Twelve children developed severe supravalvular pulmonary stenosis with a peak gradient above 50 mmHg (range: 50-120 mmHg). In these patients 19 high pressure dilatations were performed up to a diameter of 130% of the native valve dimension. The mean age at angioplasty was 17 months (range: 3-36 months). Successful intervention was defined as a > 50% decrease of predilatation peak pressure gradient or right ventricular pressure < 50 mmHg. Dilatations were performed without complications. Complete resolution was primarily achieved in 1 patient. In 7 patients the pressure gradients could be reduced to 10-45 mmHg (mean: 25 mmHg). In another two patients a palliative stent-implantation into the pulmonary trunk was necessary to reduce the pressure gradient. Because unsuccessful intervention, two patients needed subsequent operation. During follow-up of 6-9 months after intervention severe restenosis occurred in 3 patients (2 after stent-implantation; 1 after re-re-dilatation) who then also needed operation. Balloon dilatation should be the first treatment in patients with pulmonary stenosis after ASO in TGA owing to the low complication rate and the potential benefit of this procedure. Recurrent and combined stenoses with narrow pulmonary valve annulus should be treated surgically.