Surgical Resection of Biatrial Myxoma Complicated by Massive Bilateral Pulmonary Tumor Embolism Under Deep Hypothermic Circulatory Arrest: A Case Report.

Primary cardiac myxomas are the most common benign cardiac tumors and typically originate in the left atrium. Biatrial myxomas are extremely rare, and their association with massive bilateral pulmonary tumor embolism is even more uncommon. We report the case of a 32-year-old woman who presented with severe dyspnea and hypoxemia. Echocardiography and contrast-enhanced computed tomography revealed a large spherical tumor in the right atrium, a band-like tumor in the left atrium, and extensive tumor emboli obstructing the bilateral main and peripheral pulmonary arteries. The biatrial tumors were resected en bloc with the interatrial septum, and the pulmonary artery tumor emboli were removed under deep hypothermic circulatory arrest. Histopathological examination confirmed that all specimens were myxomas. Postoperatively, the patient's respiratory symptoms resolved, her estimated pulmonary artery systolic pressure decreased from 90 mmHg to 50 mmHg, and her oxygen saturation improved from 88% to 93% on room air. Although follow-up computed tomography performed three months after surgery demonstrated a residual tumor in the left pulmonary artery, the patient remained asymptomatic under warfarin anticoagulation therapy at the six-month postoperative follow-up. This case highlights a rare presentation of biatrial myxoma with massive bilateral pulmonary tumor embolism, in which intracardiac flow dynamics may have contributed to the distinct tumor morphologies, and demonstrates the utility of deep hypothermic circulatory arrest for complex pulmonary embolectomy.