Percutaneous transluminal balloon angioplasty of stenotic standard Blalock-Taussig shunts: Effect on choice of initial palliation in cyanotic congenital heart disease

To date, attempted balloon dilation of stenotic standard Blalock-Taussig shunts has been largely disappointing. It has been suggested that this may be due to the use of balloons of insufficient diameter. Balloon dilation of stenotic Blalock-Taussig shunts was attempted with use of relatively targe balloons in five patients (11 to 67 months old) with cyanotic heart disease who were becoming progressively cyanotic and polycythemic (hemoglobin 17.9 ± 1.1 g/dl) because of discrete shunt stenosis at the site of pulmonary anastomosis. Balloon diameters selected were equal to or within 1 mm of the unobstructed proximal shunt diameter. Before balloon dilation the diameter at the site of the stenosis was 2.8 ± 0.8 mm (range 1.7 to 4): after balloon dilation it was 5.7 ±I.I mm (range 4.5 to / 5). The diameter increased in all patients (range 2.0 to 3.5 mm): (he mean increase was 2.8 ± 0.2 mm (p < 0.005). Expressed as a percent, the increase in diameter at the stenosis ranged from 89% to 182.4% (mean 108.2 ± 16.8%) Before balloon dilation the systemic oxygen saturation was 72.8 ± 9.2% (range 55% to 80%) and after balloon dilation it was 83.6 ± 2.9% (range 80% to 87%). A satisfactory increase (range 6% to 25%) in blood oxygen saturation was seen in all patients; the mean increase was 10.8 ± 3.2% (p < 0.01). At follow-up, the oxygen saturation by pulse oximetry was 85.8 ±2.9% (mean 5.8 ± 1.7 months after balloon dilation) and the hemoglobin was 15.6 ± 1.9 g/dl (mean 6.6 ± 1.5 months after balloon dilation). Balloon dilation can satisfactorily relieve standard Blalock-Taussig shunt stenosis when an adequate balloon size is used. Consideration should be given to the dilatability of standard Blalock-Taussig shunts when selecting an initial palliative systemic to pulmonary shunt.