Modified Microvascular Plug as a Flow Restrictor in Hypoplastic Left Heart Syndrome with Dysplastic Tricuspid and Pulmonary Valves.

While the Norwood operation is the most common palliative surgery for neonates with hypoplastic left heart syndrome (HLHS), initial hybrid strategy aiming to restrict pulmonary blood flow and maintain systemic output is necessary when Norwood is contraindicated or at high risk. The traditional mainstay of initial hybrid palliation is surgical pulmonary artery branch banding (PABB) plus interventional ductal stenting. We present a case of a transcatheter approach for pulmonary flow restriction (PFR) that was accomplished by modifying a Medtronic microvascular plug (MVP)™. The patient is a 2.4 kg neonate diagnosed with HLHS, dysplastic tricuspid and pulmonary valves with pulmonary stenosis, tricuspid stenosis, and regurgitation. He was not considered a candidate for surgical intervention. He started developing sequelae of unbalanced pulmonary and systemic blood flow; therefore, he underwent placement of transcatheter PFR as alternative to PABB. He underwent successful orthotopic heart transplant 104 days after index procedure. This case demonstrates the significant complexity that can occur in patients with HLHS and abnormal right sided valves. Additionally, it is another example that transcatheter branch pulmonary artery flow restriction can be a safe and feasible alternative to PABB as initial palliation strategy. It may benefit patients in whom primary Norwood procedure would have increased risks or who will undergo primary transplant.