Risk factors for mortality and morbidity after the neonatal Blalock-Taussig shunt procedure

Perioperative advances have led to significant improvements in outcomes after many complex neonatal open heart procedures. Whether similar improvements have been realized for the modified Blalock-Taussig shunt, the most common palliative neonatal closed-heart procedure, is not known.

Data were abstracted from The Society of Thoracic Surgeons Congenital Heart Surgery Database (2002 to 2009). Inclusion criteria were all neonates who received a modified Blalock-Taussig shunt with or without cardiopulmonary bypass, and with or without concomitant ligation of a patent ductus arteriosus. Discharge mortality was the primary end point. A composite morbidity end point one or more of the following: postoperative extracorporeal membrane oxygenation, low cardiac output, or unplanned reoperation. Associations with patient and procedural variables were assessed with univariable and multivariable analyses.

The inclusion criteria were met by 1273 patients. The discharge mortality rate was 7.2%, and composite morbidity, as defined, was 13.1%. Primary diagnoses were classified as (1) those potentially amenable to biventricular repair (62%), (2) functionally univentricular hearts (22%), and (3) pulmonary atresia with intact ventricular septum (PA/IVS; 14%), and miscellaneous (2%). Discharge mortality stratified by primary diagnoses was PA/IVS (15.6%), functionally univentricular hearts (7.2%), and diagnoses potentially amenable to biventricular repair (5.1%). Need for preoperative ventilatory support, diagnosis of PA/IVS or functionally univentricular hearts, and any weight less than 3 kg, were risk factors for death. Preoperative acidosis or shock (resolved or persistent) and diagnosis of PA/IVS or functionally univentricular hearts were predictors of composite morbidity. Nearly 33% of the deaths occurred within 24 hours postoperatively, and 75% within the first 30 days.

The mortality rate after the neonatal modified Blalock-Taussig shunt remains high, particularly for infants weighing less than 3 kg and those with the diagnosis of PA/IVS.