The modified Blalock-Taussig shunt: clinical impact and morbidity in Fallot's tetralogy in the current era

The Blalock-Taussig shunt is considered a low-risk management option for palliation in tetralogy of Fallot, but the morbidity associated with a Blalock-Taussig shunt can have a significant impact on patient care. We reviewed the outcome for this operation in the current era.

Between 1990 and 1994, 65 children with tetralogy of Fallot received a modified Blalock-Taussig shunt. Sixty patients who had follow-up angiography were assessed for clinical outcomes and shunt-related morbidity and mortality. From the same study period, 68 of 247 pediatric patients who underwent angiography and tetralogy repair, but did not receive palliation, were randomly selected to comprise a comparison group.

Palliation was more likely in the presence of a complicated tetralogy malformation or if there was an associated medical condition. Median age at palliation was 58 days (range: 1 to 535 days). Ninety-five percent of shunts were right-sided. Self-limited morbidity complicated 11% of shunt operations. Significantly smaller distal right pulmonary arteries were observed in the palliated group before total repair compared with findings in the group without palliation and 33% of patients who underwent palliation had angiographic evidence of pulmonary artery distortion. Shunt stenosis was common and correlated with younger age at palliation. Shunt occlusion resulted in one death. Excluding noncardiac causes of death, overall survival was 90% in the palliated group versus 97% in the nonpalliated group (p = 0.09).

Pulmonary artery hypoplasia and angiographic evidence of pulmonary artery distortion are common after initial palliation by a modified Blalock-Taussig shunt. Neonatal palliation was associated with significantly smaller pulmonary arteries before repair, which necessitated additional interventions.