Hybrid Therapy for Hypoplastic Left Heart Syndrome: Reality Check

Abstract

Pilla et al. [2] are to be congratulated and commended for their honesty and integrity in reporting an unfavorable outcome for the new management strategy of patients with hypoplastic left heart syndrome (HLHS) in their article in this issue of Pediatric Cardiology. What is a hybrid intervention for HLHS? And why do it? Hybrid therapy refers to a collaborative effort between a cardiac surgeon and an interventional cardiologist in managing these patients. Ideally, this is conducted in a hybrid suite. Through a median sternotomy, the surgeon bands the branch pulmonary arteries (left and right), followed by stent implantation in the ductus arteriosus by the interventional cardiologist. In the event the atrial septal communication is restrictive, a stent is placed across the patent foramen ovale either percutaneously or via a peratrial route. This procedure is completed without the need for cardiopulmonary bypass. A few months later, when the infant is larger, a comprehensive stage II (Norwood) with a bidirectional Glenn anastomosis is performed. The obvious advantage of such an approach is the avoidance of a major operation with potential circulatory arrest in the immediate neonatal period with the known risks this carries on the developing brain. In addition, some believe that by postponing a major procedure until the infant is a few months of age, the mortality rate associated with the Norwood operation is reduced. Many centers throughout the world, including experienced centers in the United States, report high surgical mortality for the Norwood operation performed in the immediate neonatal period. In a study by the Congenital Heart Surgeon Society involving 29 centers and 710 neonates from 1994 to 2000, only 54% of patients with HLHS were alive after the Fontan operation [1]. Mortality continues to be high even with modifications of the Norwood, such as the Sano operation, in which a conduit is placed between the right ventricle and the main pulmonary artery. Additional complications may occur in the future after the Sano procedure secondary to right ventriculotomy. This has led some experienced surgeons to abandon this modification. With the newer innovation of the hybrid intervention, many believed that adopting this technique would result in a decreased mortality rate for HLHS. Unfortunately, this was not the case, as shown in the study of Pilla et al., in which there was a high mortality rate for their group of patients. In examining this study, I believe there are potential factors that have contributed to this unwanted outcome, including the small sample size at each site, the different postoperative management strategies for each site, and the lack of infrastructure. Even in centers with good postoperative management and strong infrastructure, the mortality rate of this new hybrid therapy is still high. The group at Nationwide Children’s Hospital in Columbus, Ohio, and our group in Chicago had to change the approach a few times until mortality was decreased with better outcome. It is perhaps advisable for centers wanting to pursue the hybrid approach to management of HLHS to collaborate with centers with well-established track records, such as the team at Columbus, and witness first hand the hybrid procedure and postoperative care that follows. This can be followed by proctoring by experienced cardiologists and surgeons, such as those from Columbus or the group in Giessen, Germany, conducted at the institution seeking to adopt this new methodology. Z. M. Hijazi (&) Rush Center for Congenital & Structural Heart Disease, Rush University Medical Center, Jones 770, 1653 W. Congress Parkway, Chicago, IL 60612, USA e-mail: zhijazi@rush.edu