Catheterizing Modified Blalock-Taussig Shunts: Technique and Results

Measurement of pulmonary artery (PA) size and pressure is essential for indication of permanent palliation of definitive surgery in complex lesions with pulmonary stenosis (PS) or atresia, previously palliated with modified Blalock-Taussing (MBT) shunts. From February 1992 to October 1993 with the aid of Judkins right coronary artery catheter (JR4) and 0.038 mm J curve guide-wire, we have achieved easy access to the PA through a MBT shunt in 11 consecutive patients aged 4 to 22 years (mean 8.18±5.2), weight 14 to 45 kg (mean 20.5±8.9). The patients' diagnoses were tricuspid atresia with pulmonary stenosis or pulmonary atresia (n=4), dextrocardia and complete atrio-ventricular (A-V) canal defect with PS (n=3), single ventricle with pulmonary atresia (n=1), left A-V valve atresia and malposition of the great arteries with PS (n=1), dextrocardia and right A-V valve atresia and ventricular septal defect with pulmonary atresia (n=1), and transposition of the great arteries with a ventricular septal defect and pulmonary stenosis (n=1). No complications, e.g., worsening hypoxia or dysrhythmia occurred except 1 femoral artery thrombosis. As a conclusion: access to pulmonary artery through a MBT shunt is easy, safe and effective for the visualisation of pulmonary arterial tree and measurement of the pulmonary arterial pressure.