Trapped Thrombus in the Open Foramen Ovale

A 73-year-old woman with history of malignant melanoma successfully treated 20 years previously presented to the emergency department with sudden dyspnoea and a swollen right leg. A deep venous thrombosis in the right common femoral vein was diagnosed. Based on the suspicion of a mass in the right atrium during a transthoracic echocardiography, a transoesophageal examination was performed, which showed a large thrombus trapped in a patent foramen ovale. The patient was referred to the Department of Cardiovascular Surgery for surgical thrombectomy. A Trendelenburg operation was adopted due to developing haemodynamic instability. During the heart surgery no intracardiac or intraaortic thrombus could be found. A patent foramen ovale was surgical closed and thrombectomy of old thrombus material in the pulmonary artery performed and anticoagulation with unfractionated heparin induced. An acute systemic embolism was ruled out by a computed tomography scan. The reasons for the deep venous thrombosis remained unknown. No clinical signs of recurrence of the malignant melanoma could be detected. The woman remained healthy and was discharged to a rehabilitation clinic.