Entrapped thrombus in a patent foramen ovale: complicated by pulmonary embolism without paradoxical embolism.

A 47-year-old man presented at our emergency department with sudden-onset dyspnea, chest pain, tachycardia, and bilateral leg swelling. He had hypotension and tachycardia. His oxygen saturation was 82% and plasma D-dimer level was 455 μg/L. An electrocardiogram showed sinus tachycardia and an S1Q 3T3 pattern. Transesophageal echocardiography (TEE) revealed a large thrombus (cross-sectional area, 3 × 5 cm) in the right atrium and a thrombus extending from the right atrium to the left atrium through a patent foramen ovale (PFO) (Fig. 1A). In addition, the right cardiac chambers were enlarged, and the pulmonary artery pressure was elevated, which suggested pulmonary embolism. The right atrial thrombus was mobile and, during diastole, protruded from the tricuspid valve into the right ventricle. Chest spiral computed tomography revealed bilateral pulmonary embolism (Fig. 1B). Doppler ultrasonography of the lower limbs revealed acute, bilateral, femoral deep-vein thrombosis. The patient’s respiratory and hemodynamic conditions worsened, and, without insertion of a vena cava filter, he was taken into emergency surgery. With the patient under cardiopulmonary bypass, the right atrium was incised, and the suspected thrombus was found in the right atrium, entrapped within the PFO. Most of the thrombus (16 cm) was floating in the right atrium, and a long portion was in the left atrium (Fig. 2A). There was a 1-cm-diameter thrombus on the tricuspid valve and within the pulmonary arteries. The thrombus was removed from the right chambers and the PFO, and the remnants were cleared from the left atrium. The PFO was closed by direct suture. The pulmonary arteries were incised to the level of the segmental arteries, and pulmonary artery thrombi were removed via surgical embolectomy (Fig. 2B). There was no thrombus observed on the postoperative TEE. A vena cava filter was inserted later. Images in Cardiovascular Medicine