Popliteal Venous Aneurysm Causing Pulmonary Embolism and Paradoxical Embolisation in a Patient with Antiphospholipid Syndrome

Abstract Introduction Popliteal venous aneurysms are rare and can cause recurrent pulmonary emboli despite adequate anticoagulation. Report A 43-year old patient with known antiphospholipid syndrome developed an extensive pulmonary embolus and ischaemic stroke despite anticoagulation. Duplex ultrasound confirmed a right popliteal venous aneurysm containing non-adherent multi-layered thrombus. At operation an 8 cm × 5 cm true aneurysm of the popliteal vein was excised. A postoperative echocardiogram revealed a patent foramen ovale. Discussion This case is unusual as the patient suffered a paradoxical embolism due to his patent foramen ovale. Although antiphospholipid syndrome is associated with venous thrombosis, this is usually prevented by therapeutic anticoagulation.