Left Main Coronary Artery Compression following Melody Pulmonary Valve Implantation: Use of Impella Support as Rescue Therapy and Perioperative Challenges with ECMO

The purpose of this case is to describe the complex perioperative management of a 30-year-old woman with congenital heart disease and multiple resternotomies presenting with pulmonary homograft dysfunction and evaluation for percutaneous pulmonary valve replacement. Transvenous, transcatheter Melody valve placement caused left main coronary artery occlusion and cardiogenic shock. An Impella ventricular assist device (VAD) provided rescue therapy during operating room transport for valve removal and pulmonary homograft replacement. ECMO support was required following surgery. Several days later during an attempted ECMO wean, her hemodynamics deteriorated abruptly. Transesophageal and epicardial echocardiography identified pulmonary graft obstruction, requiring homograft revision due to large thrombosis. This case illustrates a role for Impella VAD as bridge to definitive procedure after left coronary occlusion and describes management of complex perioperative ECMO support challenges. 1. Case Report A 30-year-old woman with prior Ross procedure for subaortic stenosis, presented with moderate to severe pulmonary homograft stenosis/regurgitation and New York Heart Association class II symptoms. Due to four prior sternotomies, she was considered high surgical risk and the decision was made to proceed with percutaneous transvenous transcatheter pulmonary valve replacement (Melody valve (Medtronic Inc., Minneapolis, MN, USA)) in the catheterization laboratory. After initial balloon inflation, there was visible homograft enlargement, and simultaneous aortic root angiogram was performed demonstrating patent right and left coronary arteries (LCA). The right ventricular outflow tract was then prepared with successful placement of two Palmaz stents. Repeat coronary angiography demonstrated patent LCA prior to Melody valve deployment. The Melody valve was then deployed and the patient developed progressive, severe hypotension, bradycardia, and cardiogenic shock. Transthoracic echocardiogram (TTE) demonstrated akinesis of the lateral and anterior walls of the left ventricle (LV) and severe acute mitral valve regurgitation. She instantly developed severe pulmonary edema with fluid filling the endotracheal tube and anesthesia circuit (Figure 1). A repeat coronary angiogram demonstrated acute LCA occlusion. CPR was instituted in an attempt to crush the valve and relieve the obstruction without success or hemodynamic improvement. Arrangements were immediately made for transport to the operating room, but the patient needed cardiovascular support in the interim. An