Venous Thromboembolism: Role of Vena Cava Filter in the Prophylaxis and Treatment of PE (UPDATE IN PROCESS)

Authors

Rogers, Frederick B. MD; Cipolle, Mark D. MD, PhD; Velmahos, George MD, PhD; Rozycki, Grace MD; Luchette, Fred A. MD

Author Information

From the University of Vermont, Department of Surgery, Fletcher Allen Health Care (F.B.R.), Burlington, Vermont, Department of Surgery, Lehigh Valley Hospital (M.D.C.), Allentown, Pennsylvania, Department of Surgery, Division of Trauma and Critical Care, University of Southern California (G.V.), Los Angeles, California, Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, and Department of Surgery, Division of Trauma, Critical Care, and Burns, Loyola University Medical Center (F.A.L.), Maywood, Illinois.

Submitted for publication September 1, 2001.

Accepted for publication March 15, 2002.

Any reference in this guideline to a specific commercial product, process, or service by trade name, trademark, or manufacturer does not constitute or imply an endorsement, recommendation, or any favoritism by the authors or EAST. The views and opinions of the authors do not necessarily state or reflect those of EAST and shall not be used for advertising or product endorsement purposes.

Address for reprints: Frederick B. Rogers, MD, University of Vermont Department of Surgery, Fletcher Allen Health Care, 111 Colchester Avenue, Burlington, VT 05401; email: frederick.rogers@vtmednet.org.

Statement of the Problem

Vena caval interruption is a form of PE prophylaxis that is being used more frequently in trauma patients. Many trauma patients have ongoing bleeding or recent brain, spinal cord, or ocular injury that will not tolerate even minor amounts of bleeding. These patients cannot have pharmacologic prophylaxis with heparin or heparin-like derivatives. Furthermore, patients with multiple injuries often have extremity injuries, which preclude the use of PCDs. The decision to place a prophylactic vena cava filter (VCF) in a trauma patient requires a fundamental understanding of the risk/benefit ratio. In this review, the risk/benefit ratio is explored in the high-risk trauma patient.

Process

A MEDLINE search from 1980 to 2001 was performed in which vena cava filter was cross-referenced with trauma. Four articles specifically addressed complications and long-term follow up and are included in this review (Table 6).

Recommendations

A. Level I: A Level I recommendation on this topic cannot be supported because of insufficient data.

B. Level II: A Level II recommendation on this topic cannot be supported because of insufficient data.

C. Level III: Insertion of a prophylactic VCF should be considered in very-high-risk trauma patients:

D. 1. Who cannot receive anticoagulation because of increased bleeding risk, and

E. 2. Have an injury patterns rendering them immobilized for a prolonged period of time, including the following:^52-69]

F. a. Severe closed head injury (GCS score < 8).

G. b. Incomplete spinal cord injury with paraplegia or quadriplegia.

H. c. Complex pelvic fractures with associated long bone fractures.

I. d. Multiple long bone fractures.

Patients at high risk for bleeding complications for 5 to 10 days after injury would include those with intracranial hemorrhage, ocular injury with associated hemorrhage, solid intra-abdominal organ injury (i.e., liver, spleen, kidney), and/or pelvic or retroperitoneal hematoma requiring transfusion. Other risk factors for bleeding include cirrhosis; active peptic ulcer disease; end-stage renal disease; and coagulopathy caused by injury, medication, or congenital/hereditary. In addition, it appears that age is a significant risk factor for VTE, but it is unclear at what age risk of VTE significantly increases. The need to place a prophylactic VCF may be increased in an older patient with one of the above-mentioned injuries.^[70]

Scientific Foundation

The placement of a VCF in a trauma patient who does not have an established DVT or PE is certainly controversial; however, there is no question that VCFs are efficacious. They prevent the occurrence of PE from lower extremity DVT with a success rate of about 98%.^[71] The real issue is defining who should receive these filters, and whether they are without significant complications and are cost-effective.

Several studies have reported on the use of VCFs for prophylactic indications. Golueke et al.^[72] reported on 21 filters placed prophylactically before total joint replacement. All patients received LDH, aspirin and, when possible, graduated compression stockings. No filter-related complications or episodes of PE occurred in this group. Likewise, in 1992, Webb et al.^52] reported their results of using a prophylactic filter in 24 of 52 patients undergoing acetabular fracture repair with sufficient risk factors. No insertion complications were reported. Four patients had leg edema, one with phlegmasia, and no PEs. In the 27 patients who did not receive a filter, 2 PEs were noted, one of which was fatal. Rohrer et al.^[73] reported on the use of VCFs for extended indications in 66 patients (many of whom were trauma patients). Only one PE was fatal in this group, and 22 patients had no documented DVT before filter insertion. The recurrent nonfatal PE rate was 3% and symptomatic occlusion of the inferior vena cava (IVC) occurred 4.5% of the time in this study. Major limitations of this study include the retrospective design, the inability to distinguish outcomes in the 21 patients with VCF used as prophylaxis from the 45 others, and unspecified follow-up duration. Jarrell et al.^[53] reported a favorable experience with 21 Greenfield filters that were placed in spinal cord-injured patients with documented DVT or PE. Only one PE death occurred in this group, and two instances of IVC thrombus were noted, both of which were well tolerated.

Several reports now exist in the literature on the use of prophylactic vena caval filters in trauma pa-tients.^{[53-62][64-69][74-78]} Six of these studies^{[55][56][63][64][69]} demonstrated a significant reduction in the incidence of PE in their trauma population compared with historical controls. Minimal insertion and short-term complications were reported, with 1-year patency rates ranging from 82% to 96%,^[56][58] and 2-year patency rates at 96%^56] in prophylactic filters inserted in trauma patients. Moreover, a higher DVT rate was not seen in prophylactic filter patients compared with nonfilter patients.^[55][79] A recent follow-up study with a minimum of 5 years in 199 patients showed that the filters were well tolerated. Patients went on to live active lives, with a minimal migration or cava thromboses.^[66] Likewise, Greenfield et al.^[67] reported on 249 prophylactic VCFs for trauma and noted an incidence of PE in 1.5%, a caval occlusion rate of 3.5%, and good outcome with regard to the mechanical stability of the filter. The authors concluded that the prophylactic VCF placement was associated with a low incidence of adverse outcomes and provided protection from fatal PE. However, none of these studies were Class I studies.

In contrast to the above-mentioned studies, McMurty et al.,^[77] in a retrospective review of 299 patients who had prophylactic filters placed over an 8-year period, failed to demonstrate an overall decrease in their trauma population compared with historical controls. This is the only study to date that failed to report a benefit of prophylactic VCFs in high-risk trauma patients. This study only looked at the incidence of PE in their overall trauma population and could have missed a significant decrease of PE in their high-risk population if subset analysis was performed.

The data presented herein would indicate that the risk/benefit ratio is favorable in the high-risk trauma patients. The problem is defining the high-risk patient. In the first section of this review (Risk Factors for Venous Thromboembolism after Trauma), we defined the high-risk patient for DVT, but not necessarily for PE (arguably a more serious complication of VTE). One trauma study^[61] identified four injury patterns that accounted for 92% of PEs: spinal cord injury with paraplegia or quadriplegia; severe closed head injury with a GCS score ≤ 8 for > than 48 hours; age > 55 years with isolated long bone fractures; and complex pelvic fractures associated with long bone fractures. This single-institution study may seem at conflict with what was presented in the first section of this review, which showed that on meta-analysis, head injury was not a high-risk factor. It must be noted, however, the meta-analysis dealt only with DVT. Furthermore, this study found those patients who had a GCS score > 8 for greater than 48 hours at greater risk for PE, whereas the meta-analysis did not make such a distinction. This may explain the apparent conflict in head injury as a risk factor after injury. Another retrospective review including 9,721 patients^[59] showed that the high-risk categories include head injury plus spinal cord injury, head injury plus long bone fracture, severe pelvic fracture plus long bone fracture, and multiple long bone fractures. These authors estimate that if they had used a prophylactic filter in these 2% of patients, a very dramatic reduction in PE would have been seen. They suggested that patients with an estimated risk of PE of 2% to 5%, despite prophylaxis, are reasonable candidates for prophylactic VCF placement, especially if conventional prophylactic measures cannot be used. Many years of experience with the Greenfield filter indicate that it has a patency rate of about 96%, a recurrent PE rate of 3% to 5%, and a caval penetration rate of about 2%.^[79] These complication rates were reasonable, but multiplied over the lifetime of a young patient, these rates could become important. One study indicated a significant amount of chronic venous insufficiency in long-term follow-up of prophylactic filter patients.^[62] However, with no nonfilter group to compare with, whether the filter was the cause of this chronic venous insufficiency in this very-high-risk group is not clear.

The more recent literature on this subject of VCFs discusses the bedside placement of filters^[68][75][80] and the use of ultrasound as an imaging modality in the placement of filters.^68][75][78] These studies showed that filters could be placed safely at the bedside, resulting in a decrease in operating room use and cost. Ashley et al.^[78] compared intravascular ultrasonography to contrast venography in 21 trauma patients who had prophylactic VCF placement. The authors noted that contrast venography overestimated the size of the vena cava in all cases (average vena cava diameter was 26.4 ± 3.3 mm by venography vs. 20.6 ± 3.1 mm by intravascular ultrasound). The use of contrast venography presents a significant concern when one notes that a vena cava of greater than 28 mm is a contraindication to the placement of a Greenfield VCF.

More recently, interest and experience have been increasing for the many types of retrievable filters. Much of this early work has been performed in Europe.^[81][82] The use of retrievable filters is particularly appealing to trauma surgeons whose patients are at high risk for PE for a relatively short period. Technical problems with the retrievable filters have prevented their widespread application at the present time. Nevertheless, they may have potential in the future. A recent survey of 620 trauma surgeons across the United States revealed that the potential removability of filters would significantly increase (p < 0.01) prophylactic filter placement from 29% to 53%.

Summary

No Class I studies exist to support insertion of a VCF in a trauma patient without an established DVT or PE. A fair amount of Class II and III data that may support VCF use has been accumulated in high-risk trauma patients without a documented occurrence of a DVT or PE. At this time, we recommend consideration of IVC filter insertion in patients without a documented DVT or PE who meet high-risk criteria and cannot be anticoagulated.

Future Investigation

Important unresolved issues with regard to filter use in trauma patients include the following:

• Do VCFs significantly reduce the incidence of clinically important PE in patients who receive optimal prophylaxis?
• If so, can a group of patients be identified who have a high failure rate with optimal prophylaxis?
• What are the short-term and long-term complications of VCF insertion used as primary prophylaxis in trauma patients?
• Is VCF insertion cost-effective?
• Do temporary VCFs have a role in trauma patients whose risk of PE may be high for only a short time?

Acknowledgment

We thank Jody Ciano for her help in the preparation of this article.

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