Popliteal venous aneurysm causing pulmonary embolism and paradoxical embolisation in a patient with antiphospholipid syndrome.

Background: Popliteal venous aneurysms are rare and can cause recurrent pulmonary emboli despite adequate anticoagulation.

Methods: 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 x 5 cm true aneurysm of the popliteal vein was excised. A postoperative echocardiogram revealed a patent foramen ovale.

Conclusions: 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.