Removal of vena caval filter at 224 days.

Abstract: Patients at risk of pulmonary embolism usually receive anticoagulants, which are contraindicated in trauma victims. A woman with extensive deep venous thrombosis after a vehicle accident had a nitinol Recovery Filter inserted prophylactically. After her recovery, she requested filter removal because of her intention to become pregnant. The filter was removed percutaneously without difficulty 224 days after implantation.

Key Words: deep venous thrombosis, pulmonary embolism, Recovery Filter, trauma, vena caval filters

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Venous thromboembolism (VTE) is a significant health burden, with more than 2 million cases of deep venous thrombosis (DVT) annually. In addition, approximately 600,000 patients have pulmonary embolism (PE), of which 60,000 die. (1) As many as 15% of trauma patients die of PE. (2)

Although anticoagulation is the standard treatment for VTE, inferior vena cava (IVC) filter placement is considered when anticoagulation is contraindicated or unsafe. (3) Prophylactic insertion in patients at high risk has been more controversial. The concern of many physicians has been the offset of the filter's initial benefit by the long-term risk of recurrent DVT. (4) Because of these concerns, and because many patients do not need permanent IVC filtration, there is growing enthusiasm for removable filters. (5)

Case Report

A 27-year-old woman received a LeFort I facial fracture and subdural hematoma after an accident involving a vehicle in which she was an unrestrained passenger. Initially, she had a Glasgow Coma Scale score of 6, and her hospital course was complicated by extensive DVT and upper gastrointestinal bleeding secondary to stress ulcers.

Because of the patient's age, after discussions with her parents, a nitinol Recovery Filter (C.R. Bard, Inc, Murray Hill, NJ; Fig. 1) was placed. At that time, this device was approved by the Food and Drug Administration only for permanent use in the United States, although it was cleared as both a permanent and a retrievable filter elsewhere. The patient stabilized and was transferred to an acquired brain injury unit (Shepherd Center, Atlanta, GA), where she made a full recovery. She later expressed a desire to have the filter removed, as the planned to become pregnant. In the interim, the filter became Food and Drug Administration-approved for retrieval. The Recovery Filter was removed percutaneously 224 days after implantation.

With the patient under conscious sedation, a 12F sheath was placed in the right internal jugular vein, and a 5F straight multisidehole catheter (Cook, Inc, Bloomington, IN) was advanced through the filter over an angled Glidewire (Terumo Medical, Somerset, NJ). The filter evidenced a slight leftward tilt but had no visible thrombus (Figs. 2 and 3). Exchange was made for a 5F Davis catheter over an exchange-length Glidewire, which was used to pass the wire just to the left of the midline vertical axis of the filter. The Recovery tapered sheath was then advanced so that its radiopaque tip was approximately 6 cm above the filter apex, the tapered dilator was removed, and the Recovery Cone Retrieval System was passed over the guide wire, deployed, and slid over the filter apex. The filter was removed, and a cavagram confirmed absence of IVC injury from filter removal (Fig. 4). Of particular importance was the absence of trapped thrombus.

Discussion

Removable filters may be temporary or optional. The former must be removed and usually remain anchored outside the body ("filter on a leash"), whereas the latter may be temporary or permanent. In a multicenter registry of temporary filters in Germany, (6) temporary filters remained for no longer than 14 days because of explantation problems caused by endothelialization, which is assumed to increase the longer the filter remains in situ. (7)

[FIGURE 1 OMITTED]

The first temporary filter to undergo a clinical trial in the United States was the Tempofilter (B. Braun Medical Inc, Bethlehem, PA), which has a silicone olive for implantation in the subcutaneous tissue. The trial was halted in December 1997 when a patient had a fatal PE after device migration to the right atrium.

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

Interest in optional filters began with the first report of successful retrieval in 1986. (8) Optional filters have several advantages. First, they are not connected to the skin insertion site, limiting the risk of thrombosis or infection. (9) Second, they can be left in permanently if necessary. One example is the Gunther Tulip filter (Cook, Inc., Bloomington, IN). The manufacturer recommends removal within 10 days because of the potential for endothelialization, which might make removal dangerous or impossible. However, several studies have shown successful removal after as long as 62 days. (10) This maneuver adds its own risk and expense to the procedure. A major injury to the IVC can result from aggressive attempts to remove a filter that has become incorporated into the wall of the IVC. (11) Although the absolute length of time filter protection will be needed is not always known, a filter that must be removed or manipulated with 12 to 14 days probably is of limited utility.

[FIGURE 4 OMITTED]

The "window of risk" for VTE is particularly difficult to evaluate in trauma patients. These patients are often young, with extensive injuries that necessitate prolonged immobilization, contraindicate anticoagulation, and make surveillance of the lower extremities with ultrasound difficult or impossible. Prophylactic IVC filters appear to be the ideal solution. However, the risk of long-term complications with permanent filters in this situation is as high as approximately 6%, (12) and the risks to the mother or fetus during later pregnancy are largely unknown. Temporary filters would cover these patients through the critical period and could be removed when it is safe to resume anticoagulation.

The Eastern Association for the Surgery of Trauma has developed guidelines for prophylactic IVC filters in high-risk patients, recommending them for those who cannot receive anticoagulation or who have conditions such as severe closed head injury (Glasgow Coma Scale < 8) or complex pelvic fractures. The rate of PE development in this setting is as high as 32%, (13) and prophylactic filters appear to be warranted. (14) Guidelines also have been published for the use of IVC filters in trauma patients. (15)

Conclusion

Asch (16) was the first to describe use of the nitinol Recovery Filter. The mean implantation time (53 days) was far greater than in reports with other retrievable devices, and retrieval as late as 134 days was reported. In the present case, a Recovery Filter was safely retrieved more than 7 months after implantation. The benefit of IVC filtration, combined with avoidance of the long-term effects of an implantable device, particularly in a patient with a long life expectancy, is a significant step in the prevention of VTE in a case such as this.

The light shines not on us, but in us.
--John Muir

Accepted October 19, 2004.

References

1. Hirsh J, Hoak J. Management of deep vein thrombosis and pulmonary embolism: a statement for healthcare professionals: Council on Thrombosis (in consultation with the Council on Cardiovascular Radiology), American Heart Association. Circulation 1996;93:2212-2245.

2. Elliott CG, Dudney TM, Egger M, et al. Calf-thigh sequential pneumatic compression compared with plantar venous pneumatic compression to prevent deep-vein thrombosis after non-lower extremity trauma. J Trauma 1999;47:25-32.

3. Levine MN, Raskob G, Landefeld S, et al. Hemorrhagic complications of anticoagulant treatment. Chest 1998;114:511S-523S

4. Duperier T, Mosenthal A, Swan KG, et al. Acute complications associated with Greenfield filter insertion in high-risk trauma patients. J Trauma 2003;54:545-549.

5. Athanasoulis CA, Kaufman JA, Halpern EF, et al. Inferior vena caval filters: review of a 26-year single-center clinical experience. Radiology 2000;216:54-66.

6. Lorch H, Welger D, Wagner V, et al. Current practice of temporary vena cava filter insertion: a multicenter registry. J Vasc Interv Radiol 2000;11:83-88.

7. Burbridge BE, Walker DR, Millward SF. Incorporation of the Gunther temporary inferior vena cava filter into the caval wall. J Vasc Interv Radiol 1996;7:289-290.

8. Darcy MD, Smith TP, Hunter DW, et al. Short-term prophylaxis of pulmonary embolism by using a retrievable vena cava filter. Am J Roentgenol 1986;147:836-838.

9. Millward SF. Temporary and retrievable inferior vena cava filters: current status. J Vasc Interv Radiol 1998;9:381-387.

10. de Gregorio MA, Gamboa P, Gimeno MJ, et al. The Gunther Tulip retrievable filter: prolonged temporary filtration by repositioning within the inferior vena cava. J Vasc Interv Radiol 2003;14:1259-1265.

11. Epstein DH, Darcy MD, Hunter DW, et al. Experience with the Amplatz retrievable vena cava filter. Radiology 1989;172:105-110.

12. Gosin JS, Graham AM, Ciocca RG, et al. Efficacy of prophylactic vena cava filters in high-risk trauma patients. Ann Vasc Surg 1997;11:100-105.

13. Velmahos GC, Kern J, Chan LS, et al. Prevention of venous thromboembolism after injury: an evidence-based report, II: analysis of risk factors and evaluation of the role of vena caval filters. J Trauma 2000;49:140-144.

14. Rogers FB, Strindberg G, Shackford SR, et al. Five-year follow-up of prophylactic vena cava filters in high-risk trauma patients. Arch Surg 1998;133:406-411.

15. Recommended reporting standards for vena caval filter placement and patient follow-up: Vena Caval Filter Consensus Conference. J Vasc Surg 1999;30:573-579.

16. Asch MR. Initial experience in humans with a new retrievable inferior vena cava filter. Radiology 2002;225:835-844.

RELATED ARTICLE: Key Points

* Prophylactic placement of a vena caval filter in patients at high risk of pulmonary embolism has been controversial.

* Certain optional vena caval filters may remain in place safely for extended periods.

* The benefit of inferior vena cava filtration with a removable filter is a significant step in the prevention of pulmonary embolism.

John C. Lipman, MD, FSIR 

From the Atlanta Interventional Institute, Marietta, GA.

The author has no financial relationship, ownership, or stake in the Recovery Filter or C.R. Bard, Inc.

Reprint requests to Dr. John C. Lipman, 2480 Windy Hill Road, Marietta, GA 30067. Email: [e-mail]