Bilateral iliac vein filtration. An effective alternative to caval filtration in patients with megacava.

Greenfield filters were placed bilaterally in the iliac veins in five of 250 patients undergoing percutaneous filter placements. Four of the five patients had megacava (inferior vena cava diameter greater than 28 mm). In all patients, the filters were effective in preventing pulmonary embolism. Follow-up at 9 months in two patients revealed no changes of chronic venous insufficiency or venous stasis. Iliac filtration should be considered in patients in whom a caval filter cannot be placed because of large caval size or because it is technically difficult due to iliac vein tortuosity.