Understanding the Hybrid Stage I Approach for Hypoplastic Left Heart Syndrome.

Hybrid stage I palliation combines cardiothoracic surgery and interventional transcatheter procedures for treatment of hypoplastic left heart syndrome. The approach is an alternative to the Norwood procedure, the traditional first stage of surgical palliation. Hybrid stage I palliation involves placing bilateral branch pulmonary artery bands and a patent ductus arteriosus stent through a median sternotomy, performed without cardiopulmonary bypass. The purpose of the bands is to control blood flow to the lungs and protect the pulmonary bed while the stent sustains systemic cardiac output. A balloon atrial septostomy is performed to create an atrial septal defect for unobstructed blood flow from the left atrium to the right atrium. The second stage of palliative surgery is the comprehensive stage II, which incorporates removal of the stent and pulmonary artery bands, atrial septectomy, anastomosis of the diminutive ascending aorta to the main pulmonary artery, aortic arch augmentation, and bidirectional cavopulmonary anastomosis. The traditional Fontan procedure completes the series of palliation.