Bard Recovery Filter: Evaluation and Management of Vena Cava Limb Perforation, Fracture, and Migration

Appearance of perforated arms on CT and inferior vena cavogram. The Recovery filter has six arms and six legs. (a) Intact top of the filter with six arms. On images (b), note that all the arms are outside the IVC. Several of the arms are completely surrounded by fat. The arm at 7 o'clock (white arrow) appears to be in a small vein. The six legs are in the center of IVC and none of the legs have perforated the IVC. (c) On an image taken caudal to b, the tips of only four arms are noted. Arms at 5 and 7 o'clock are adjacent to but outside the IVC (note acute angle between arm and IVC wall), and these were counted as perforations. (d) Anteroposterior view of the IVC shows the arms on either side to be well outside the IVC.

Narrowed and irregular IVC is seen below the Recovery filter. There is a prominent collateral vessel to the left.

(a) Filter arm fracture site just below filter cap (arrow) viewed through a dissecting microscope. Scanning electron micrographs of representative arm fracture (b) and hook fracture (c) surfaces. Arm fractures were characterized by high-cycle fatigue fracture with initiation at the surface of each wire (arrow), propagation of the fatigue crack through approximately 25% of the arm wall thickness, and final ductile overload failure. Hook fractures were characterized by ductile bending overload failure with possible initiation from low-cycle bending fatigue most likely attributed to the retrieval operation. (Available in color online at www.jvir.org.)

Chest radiograph obtained in a patient with a Recovery filter who was seen in the emergency room for atypical chest pain.

Abdominal CT findings of fracture. (a) At the top of the filter, the cap is in the center of the IVC. Only five arms are present (compare with Fig 1a). The arm at nine o'clock is absent. (b) The most caudal image demonstrates the tips of the remaining arms: three arms have perforated the IVC, extending beyond the IVC wall. Arms at 3 and 6 o'clock were not counted as perforations because of a lack of a clear acute angle of tissue between the arm and the IVC wall.

(a) Magnified view of right upper lobe (same as Fig 4). Migrated arm (open arrow) was missed on numerous chest radiographs and chest CT examinations over a period of 18 months. (b) Fragment in right upper lobe is seen on contrast-enhanced chest CT scan (white arrow). (c) Axial images with and without contrast medium windowed and leveled for mediastinum, lung, and bone, respectively. White arrow points to the hard-to-see filter fragment on the contrast images.