Introduction
The treatment of children with pulmonary hypertension (PH) has evolved dramatically over the last 30 years. Early data demonstrated a median survival of less than one year whereas current estimates now predict 5-year survival rates of at least 80%. 1,2,3 This improvement likely reflects the development of PH-specific drugs and an increased awareness and understanding of PH pathology along with the development of specialized centers and personnel to treat it. Nonetheless, despite these advances, children still die from their disease. Children with severe PH who fail aggressive medical management have limited options. Historically, lung transplantation has been the palliative procedure most often considered in these critically compromised children. However, survival with pediatric lung transplantation remains relatively limited with current median survival of ~7 years in children transplanted for idiopathic PH and even lower survival for children with non-idiopathic PH, a median of ~3 years.4,5 In addition, lung transplantation involves expensive, highly technical and specialized care that only a relatively small number of centers around the world can afford to offer. Consequently, care providers have looked for other ways in which to treat these medically refractory children. Ultimately, most children with severe PH die because of right ventricular failure. Thus, a number of interventions have developed over the years as a means to ameliorate right ventricular dysfunction short of transplantation. Physiologically these procedures fall into two categories: 1) creating a pre-tricuspid valve shunt, essentially making an atrial septal defect, or 2) creating a post-tricuspid valve shunt, typically a pulmonary-to-systemic anastomosis at the level of the great vessels, e.g., a Potts shunt. We will discuss these options in more detail. Other interventions for supporting the failing right ventricle such as ECMO, paracorporeal lung assist devices or right ventricular assist devices are therapies that are utilized almost exclusively in the intensive care setting and will not be covered in this article.