The Bird's Nest Filter. An alternative to long-term oral anticoagulation in patients with advanced malignancies

Thromboembolic complications are common in patients with advanced malignancies. For these patients anticoagulation with warfarin is often complicated by severe bleeding. For this reason we evaluated the safety and efficacy of the Bird's Nest Filter, a new device capable of preventing migration of thromboemboli to the pulmonary arteries through interruption of the inferior vena cava. We report a series of 31 unselected patients with advanced malignancies and thromboembolic disease in whom the filter was used in lieu of chronic full-dose warfarin anticoagulation. No documented cases of pulmonary emboli occurred after insertion of the filter. Placement of the filter was uncomplicated. Eight patients (25.8%) developed lower-extremity edema. Venous thrombosis distal to the filter was documented in six (19.4%) patients but did not require institution of heparin or warfarin. Two patients (6.5%) required treatment with aspirin for painful lower-extremity thrombophlebitis. No filter migration was documented. We conclude that the use of the Bird's Nest Filter is an option for patients with cancer-related lower-extremity thrombosis who are at risk for pulmonary emboli and are poor candidates for full-dose systemic anticoagulation with warfarin. A prospective randomized trial comparing the filter and the new strategy of low-dose anticoagulation with warfarin will be needed to completely validate this approach.