Growth of the pulmonary arteries following Blalock-Taussig shunt

The Blalock-Taussig (BT) shunt remains the standard systemic-to-pulmonary artery shunt. We reviewed our experience with the classic BT shunt in terms of mortality, patency, duration of palliation, and growth of the pulmonary artery. Records were reviewed in 49 consecutive patients, 25 of whom were less than one month old at the time of operation. They underwent a total of 53 BT shunts. Also, the pulmonary artery index (PAI), or the sum of the cross-sectional areas of the right and left pulmonary arteries standardized by the body surface area (BSA), was calculated. There were 4 operative deaths (7.5%) and 1 late death (2.0%). Early shunt thrombosis (within 72 hours postoperatively) occurred in 3 patients. Four patients required a second BT shunt, 5 underwent a palliative outflow tract reconstruction, and 5 required a polytetrafluoroethylene graft. Twenty-one patients underwent a corrective procedure, and 26 underwent a second cardiac catheterization. Of these 26 patients, 24 represent the subgroup used to assess the growth of the pulmonary arteries. The mean duration of palliation was 25.15 months. Mean PAI increased significantly from 127 +/- 40 mm2/BSA pre-shunt to 286.1 +/- 144 mm2/BSA post-shunt (p less than .004). This series demonstrates that the pulmonary arteries do grow after BT shunt. Pulmonary artery growth in patients with tetralogy of Fallot was greater than that in patients with single ventricle, and the duration of palliation was acceptable in most patients. Calculation of PAI may aid in the decision whether to perform a corrective surgical procedure or a second palliative shunt procedure.