The Novel Use of Mechanical Circulatory Support to Demonstrate Pulmonary Hypertension Reversibility in Mitral Stenosis

Abstract

<h3>Introduction</h3> Pulmonary Hypertension (PHT) presents a significant risk factor for cardiac surgery. Patients with reversible PHT have better surgical outcomes. We present a novel and successful approach to demonstrate PHT reversibility and relieve pulmonary congestion in a patient with severe mitral stenosis using extracorporeal left atrial to femoral artery bypass MCS. <h3>Case Report</h3> A 56-year-old female with a history of rheumatic mitral stenosis presented with severe pulmonary edema. Transthoracic echocardiogram demonstrated severe MS (mean valve area .5 cm2, mean gradient of 20 mmHg) with preserved left ventricular ejection fraction. TEE confirmed no thrombus formation in the left atrium. Right heart catheter exam demonstrated elevated pulmonary artery (PA) pressures of 110/80 mmHg and a wedge pressure of 40 mmHg. PHT reversibility was desired to demonstrate the benefit of surgical intervention. A simulation using pulmonary vasodilator therapy would likely exacerbate her pulmonary venous congestion; an intra-aortic balloon pump or a percutaneous left ventricular assist device would not adequately unload the pulmonary venous pressure. Extracorporeal left atrial to femoral artery bypass MCS was used to unload the left atrium directly. After MCS initiation, PHT reversibility and surgical indication was confirmed with significantly improved pulmonary pressures (Table 1). The volume status and lung congestion were optimized preoperatively. Intraoperatively, the MCS left atrial inflow cannula was pulled back into the right heart and used as a venous cannula for cardiopulmonary bypass. Successful mitral valve replacement was performed. Postoperatively, the mitral valve mean gradient was 3 mmHg. The patient was discharged home on day 15. <h3>Summary</h3> The novel use of extracorporeal MCS with left atrial to femoral arterial bypass provides a novel strategy to simulate PHT reversibility and optimization for MS surgery.