Retrievable Vena Cava Filters
Could these devices reduce morbidity while offering optimal protection?
Pulmonary embolism affects the lives of more than 600,000 patients in the US and claims the lives of 20% of these patients.1 Although thrombolytic therapy has been used with great success, anticoagulation remains the accepted standard therapy for many patients with deep venous thrombosis and pulmonary embolism. The major risk factors of older age, immobility, hypercoagulable states, and a history of deep venous thrombosis are well known. Recent studies have added morbid obesity, total hip and knee replacement surgery, major trauma, and extensive abdominal and pelvic surgery to the growing list of high-risk patients.2
CURRENT PERMANENT DEVICES
There is no argument that subcutaneous heparin or low-molecular-weight heparin and pneumatic compression devices have reduced the risk of deep venous thrombosis and pulmonary embolism. However, the prophylactic placement of vena cava filters in high-risk patients has been documented in the trauma litera-ture.3-5 As interventionalists, we see the benefits of reducing the risk of pulmonary embolism to nearly zero—but at what cost?6 The morbidity of the procedure is very low and includes access site thrombosis, as well as errors associated with malpositioning and migration.7 The true incidence of vena cava occlusion is unknown, but some studies have shown filter occlusion rates up to 19%.7 Perforation is extremely rare, but cases of abdominal pain and duodenal erosion have been reported.8 This brings to mind an interesting question: Because most complications of vena cava filters occur as late events, could retrievable vena cava filters reduce the morbidity while offering optimal protection during a critical period when the risk of pulmonary embolism is greatest?
RETRIEVABLE VENA CAVA FILTERS
There are countless new designs for retrievable vena cava filters, ranging from spiral filters to square stents.9,10 There are three FDA-approved permanent vena cava filters that may soon have an additional indication for retrieval.
Gunther Tulip Filter
The Gunther Tulip filter (Cook Inc., Bloomington, IN) (Figure 1) has perhaps the widest experience in both the US and Europe. There are several reports in the literature supporting its value as a temporary filter.11-13 It has the capability of deployment from either a femoral or jugular route. It must be retrieved from a jugular vein approach. Most authors recommended retrieval within 14 days.
The OptEase filter (Cordis Endovascular, a Johnson & Johnson company, Miami, FL) (Figure 2) has a unique self-centering design that provides dual-level filtration. It can be deployed from both the transfemoral and transjugular approaches using the same kit. It is the only potentially retrievable filter that is recovered from a femoral vein approach and requires a small retrieval system (10F guiding catheter) (Figure 3).
Recovery Nitinol Filter
The Recovery nitinol filter (Bard Peripheral Vascular, Tempe, AZ) (Figure 4) has generated a great deal of interest as a retrievable system because it has no barbs for fixation, and therefore has a much longer potential window for retrieval. One group has reported successful retrieval of filters as long as 134 days after insertion.14 There was, however, one filter that migrated after clot capture. This emphasizes the one minor weakness of retrievable filters with extended placement times; these filters may have less surface area of contact with the vena cava to avoid tissue ingrowth and fixation.
Are physicians willing to trade better vena cava wall fixation for extended retrieval times? My approach to this problem is simple—if the patient is too ill to retrieve a filter within 14 to 21 days, leave the device as a permanent vena cava filter. Most patients who are candidates for retrievable filters are high-risk patients because of multiple injuries or impending major surgery. If they are recovering sufficiently within 2 weeks and a venous duplex scan is negative for deep venous thrombosis, they can be taken to the radiology suite for central venography. If the retrievable filter is free of major clot, it can be safely removed. If a large thrombus is seen, one could argue for mechanical or thrombolytic removal of the clot and filter retrieval but, in my opinion, this is a good reason to keep the filter in the patient. There are some physicians who have used periodic repositioning of the filter to extend the retrieval time.15 This can be done safely, but entails recurrent central venous access. Again, I would carefully consider whether the added procedure has greater benefit to the patient than leaving the filter alone. This issue is best settled on a case-by-case basis.
There are potential future applications of retrievable vena cava filters. Case reports in the literature cite success in the use of retrievable vena cava filters for pregnant patients with thromboembolism.16,17 The treatment of extensive iliofemoral deep venous thrombosis with thrombolytic therapy or surgical thrombectomy can cause pulmonary embolism during the procedure. Although permanent vena cava filters have been used in this setting, retrieval of the filter after resolution of the deep vein thrombosis is appealing. We have also used retrievable vena cava filters “off label” as temporary filters during resection of renal cell cancers with tumor thrombus extension into the inferior vena cava. Trauma and major orthopedic surgery will most likely encompass the greatest use of retrievable vena cava filters, but with the increasing number of obese patients undergoing major operations, the use of retrievable filters will continue to grow. I believe ongoing prospective studies will support elevated body mass index as a major predictor of pulmonary embolism and will have a tremendous impact on the future of retrievable vena cava filters.
John H. Matsuura, MD, is Assistant Professor of Surgery, Emory University School of Medicine, Atlanta; Assistant Professor of Surgery, Medical College of Georgia, Augusta; Director of Vascular Surgery, Atlanta Medical Center, Atlanta, Georgia. He holds no financial interest in any product or manufacturer mentioned herein. Dr. Matsuura may be reached at (404) 524-0095;
1. Bick RI, Kaplan H. Syndromes of thrombosis and hypercoagulability: congenital and acquired causes of thrombosis. Med Clin North Am. 1998;82:409-458.
2. Kroegel C, Reissig A. Principle mechanisms underlying venous thromboembolism: epidemiology, risk factors, pathophysiology, and pathogenesis. Respiration. 2003;70:7-30.
3. Khansarinia S, Dennis JW, Veldenz HC, et al. Prophylactic Greenfield filter placement in selected high-risk trauma patients. J Vasc Surg. 1995;22:231-236.
4. Langan EM, Miller RS, Cassey WJ, et al. Prophylactic inferior vena cava filters in trauma patients at high-risk: follow-up examination and risk/benefit assessment. J Vasc Surg. 1999;30:484-490.
5. Carlin AM, Tyburski JG, Wilson RF, et al. Prophylactic and therapeutic inferior vena cava filters to prevent pulmonary emboli in trauma patients. Arch Surg. 2002;137:521-527.
6. Greenfield LJ, Proctor MC, Michaels AJ, et al. Prophylactic vena caval filters in trauma: the rest of the story. J Vasc Surg. 2000;32:490-497.
7. Becker DM. Inferior vena cava filters: indications, safety, effectiveness. Arch Intern Med. 1992;152:1985-1994.
8. Feezor RJ, Huber TS, Welborn BM, et al. Duodenal perforation with an inferior vena cava filter: an unusual cause of abdominal pain. J Vasc Surg. 2002;35:1010-1012.
9. Xian AY, Roy S, Hosaka J, et al. In vitro evaluation of a new temporary venous filter: the spring filter. Cardiovasc Intervent Radiol. 1995;18:315-320.
10. Pavcnik D, Uchida BT, Keller FS, et al. Retrievable IVC square stent filter: experimental study. Cardiovasc Intervent Radiol. 1999;22:239-245.
11. Millward SF, Bhargava A, Aquino J, et al. Gunther tulip filter: preliminary clinical experience with retrieval. J Vasc Intervent Radiol. 2000;11:75-82.
12. Neuerburg JM, Gunther RW, Vorwerk D, et al. Results of a multicenter study of the retrievable tulip vena cava filter: early clinical experience. Cardiovasc Intervent Radiol. 1997;20:10-16.
13. Millward SF, Olivia VL, Stuart SD, et al. Gunther tulip retrievable vena cava filter: results from the registry of the Canadian Interventional Radiology Association. J Vasc Intervent Radiol. 2001;12:1053-1058.
14. Asch MR. Initial experience in humans with a new retrievable inferior vena cava filter. Radiology. 2002;225:835-844.
15. Tay K, Martin ML, Fry PD, et al. Repeated Gunther tulip inferior vena cava filter repositioning to prolong implantation time. J Vasc Intervent Radiol. 2002;13:509-512.
16. Meill AM, Appleton DS, Richards P. Retrievable inferior vena cava filter for thromboembolic disease in pregnancy. Br J Obstet Gynecol. 1997;104:1416-1418.
17. Ferraro F, D’Ignazio N, Matarazzo A, et al. Thromboembolism in pregnancy: a new temporary caval filter. Minerva Anestesiologica. 2001;67:381-385.