A rare case of arteriovenous fistula formation in a patient with inferior vena cava thrombosis, successfully managed with endovascular recanalisation

Inferior vena cava (IVC) filters are recommended for patients with proximal deep vein thrombosis (DVT) who are not eligible for anticoagulation. Long-dwelling filters are well-known to be associated with the development of IVC thrombosis. Chronic caval occlusion can lead to a severe post-thrombotic syndrome (PTS), with manifestations of chronic venous insufficiency in the lower extremities. Animal studies have shown that post-thrombotic inflammation can trigger the development of an arteriovenous fistula (AVF), however, there is limited evidence for this phenomenon in patients with PTS. We describe the case of a spontaneous AVF in a patient with long-standing IVC thrombosis. It was postulated that the AVF could be compounding the venous hypertension and severe swelling of his lower extremities. The case additionally demonstrates the successful results of endovascular recanalisation for an occluded filter in the presence of an AVF.