Alfred Blalock and Helen Taussig ushered in the surgical treatment of congenital heart disease with the introduction in clinical practice of a systemic artery-to-pulmonary artery (PA) shunt in 1944. In the current era of early complete correction of congenital heart disease, the Blalock–Taussig shunt still plays an important role in the surgical management of newborns and infants with inadequate pulmonary blood flow.1–3 The paradigm shift emphasizing early complete repair is based on contemporary data demonstrating the deleterious effects of palliative physiology, coupled with the realization that most infants can tolerate operative correction. However, some malformations still require a staged approach toward eventual correction, while others may necessitate a palliative procedure when anatomic or patient factors preclude complete repair. A staged repair is often favored when there are extenuating technical issues that stem from morphologic complexity or severe extracardiac pathology that would make one-stage correction prohibitive. The functionally single ventricle (Chapter 77) is an example of this strategy, by which a staged palliative approach eventually achieves the goal of separating the pulmonary and systemic circulations.
Palliative or staged procedures are primarily designed to modify pulmonary blood flow, enhance intracardiac mixing, or rehabilitate a ventricle prior to definitive surgery. For example, aortopulmonary shunts will increase pulmonary blood flow, while a pulmonary artery band (PAB) will limit pulmonary perfusion. Although conceptually simple, palliative operations pose several unique challenges. Intraoperatively, the infants are often low birth-weight or even preterm, and might have other extracardiac factors that have mitigated against complete repair. Postoperatively, the palliated state complicates patient management, as equipoise must be achieved between the pulmonary and systemic circulations (Chapter 60), also inviting the opportunity for interstage attrition.
As early complete repair has become increasingly more common, indications for systemic-to-PA shunts are in some respects controversial. However, a shunt still remains the initial procedure for duct-dependent single-ventricle lesions and also specific lesions with inadequate pulmonary blood flow in the presence of two adequate ventricles. In those instances, a systemic-to-PA shunt may be necessary for early survival, at the expense of further surgical procedures.
A systemic-to-PA shunt could be indicated in any anomaly that presents with obstruction of blood flow either entering or exiting the right heart (in specific types of tricuspid atresia, or pulmonary stenosis or atresia not amenable to percutaneous intervention, for example). Other indications include anomalies with unbalanced pulmonary blood flow where a systemic-to-PA shunt (alone or, rarely, with a PAB) can be used to provide a controlled source of pulmonary blood flow.
Classic Blalock–Taussig Shunt
The development of palliative procedures began at the Johns Hopkins Hospital with the goal of providing improved blood flow to the pulmonary vascular bed in cyanotic children; the subclavian-to-right PA shunt was introduced clinically in 1944.3 This method of systemic-to-PA shunt followed the pioneering experimental ...