Operative outcome and intermediate term follow-up of neonatal Blalock-Taussig shunts

The neonatal age group is considered to be one of the important risk factors for perioperative morbidity and mortality as well as poor long-term patency following Blalock-Taussig shunts.

Out of a total of 190 patients who underwent Blalock-Taussig shunts in our institute between July 1998 and July 2000, 20 patients were aged less than 30 days and this neonatal cohort was studied retrospectively. The mean age was 18+/-11 days (range: 3-30 days). The mean weight of the babies was 3.1+/-0.7 kg, the smallest weighed 2.1 kg. The cardiac anatomy was tetralogy of Fallot with pulmonary atresia in 6, pulmonary atresia with intact ventricular septum in 3, tricuspid atresia in 5 and complex single ventricle physiology in the rest. All patients were deeply cyanotic and preoperative prostaglandin E1 was needed in 10 patients to ensure ductal patency and maintain oxygen saturations prior to the shunt operation. The mean hilar right and left pulmonary artery sizes were 3.99+/-0.44 mm and 3.69+/-0.79 mm, respectively. Three patients (15%) had significant stenosis at the site of duct insertion. The shunts were accomplished with 3.5 mm polytetrafluoroethylene grafts in 7 patients (35%) and 4 mm in the rest. The mean duration of mechanical ventilation was 2.0+/-2.83 days, one patient who developed bronchopneumonia needed prolonged ventilation for 14 days. The mean intensive care unit stay was 4.79+/-2.66 days. The mean hospital stay was 11.7+/-6.4 days. Five patients who developed sepsis stayed beyond 14 days. There were 3 deaths (immediate post-operative shock and possibly shunt malfunction in 1, bronchopneumonia in 1 and late shunt thrombosis at 3 months in 1). Two patients had late shunt block, one of those mentioned above and the other at 3 months secondary to infective endarteritis of the right pulmonary artery. All these infants received 4 mm grafts. All the 3.5 mm grafts were patent at follow-up. Seventeen patients were alive and well at follow-up (mean: 9 months, range: 3-21 months) with a mean resting systemic oxygen saturation of 77% (66%-95%).

The overall shunt patency rate after neonatal Blalock-Taussig shunt is about 80% on intermediate term follow-up. A smaller graft size (3.5 mm) does not appear to be an incremental risk factor for shunt blockade and operative mortality.