The use of retrievable inferior vena cava filters in severely injured military trauma patients

Prophylactic Inferior Vena Cava Filters for Venous Thromboembolism in Adults With Trauma: An Updated Systematic Review and Meta-Analysis

Background: Trauma is an independent risk factor for venous thromboembolism (VTE). Due to contraindications or delay in starting pharmacological prophylaxis among trauma patients with a high risk of bleeding, the inferior vena cava (IVC) filter has been utilized as alternative prevention for pulmonary embolism (PE). Albeit, its clinical efficacy has remained uncertain. Therefore, we performed an updated systematic review and meta-analysis on the effectiveness and safety of prophylactic IVC filters in severely injured patients. Methods: Three databases (MEDLINE, EMBASE, and Cochrane) were searched from August 1, 2012, to October 27, 2021. Independent reviewers performed data extraction and quality assessment. Relative risk (RR) at 95% confidence interval (CI) pooled in a randomized meta-analysis. A parallel clinical practice guideline committee assessed the certainty of evidence using the GRADE approach. The outcomes of interest included VTE, PE, deep venous thrombosis, mortality, and IVC filter complications. Results: We included 10 controlled studies (47 140 patients), of which 3 studies (310 patients) were randomized controlled trials (RCTs) and 7 were observational studies (46 830 patients). IVC filters demonstrated no significant reduction in PE and fatal PE (RR, 0.27; 95% CI, 0.06-1.28 and RR, 0.32; 95% CI, 0.01-7.84, respectively) by pooling RCTs with low certainty. However, it demonstrated a significant reduction in the risk of PE and fatal PE (RR, 0.25; 95% CI, 0.12-0.55 and RR, 0.09; 95% CI, 0.011-0.81, respectively) by pooling observational studies with very low certainty. IVC filter did not improve mortality in both RCTs and observational studies (RR, 1.44; 95% CI, 0.86-2.43 and RR, 0.63; 95% CI, 0.3-1.31, respectively). Conclusion: In trauma patients, moderate risk reduction of PE and fatal PE was demonstrated among observational data but not RCTs. The desirable effect is not robust to outweigh the undesirable effects associated with IVC filter complications. Current evidence suggests against routinely using prophylactic IVC filters.

Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Venous thromboembolism (VTE) is a potential sequela of injury, surgery, and critical illness. Patients in the Trauma Intensive Care Unit are at risk for this condition, prompting daily discussions during patient care rounds and routine use of mechanical and/or pharmacologic prophylaxis measures. While VTE rightfully garners much attention in clinical patient care and in the medical literature, optimal strategies for VTE prevention are still evolving. Furthermore, trauma and surgical patients often have real or perceived contraindications to prophylaxis that affect the timing of preventive measures and the consistency with which they can be applied. In this Clinical Consensus Document, the American Association for the Surgery of Trauma Critical Care Committee addresses several practical clinical questions pertaining to specific or unique aspects of VTE prophylaxis in critically ill and injured patients.

Prevention of Deep Venous Thromboembolism

The nature of many combat wounds puts patients at a high risk of developing deep venous thrombosis (DVT) and pulmonary embolism (PE), which fall under the broader disease category of venous thromboembolism (VTE). In addition to the hypercoagulable state induced by trauma, massive injuries to the extremities, prolonged immobility, and long fixed wing transport times to higher echelons of care are unique risk factors for venous thromboembolism in the combat-injured patient. These risk factors mandate aggressive prophylaxis for DVT and PE that can effectively be achieved by the use of lower extremity sequential compression devices and low dose unfractionated heparin or low molecular weight heparin. In addition, inferior vena cava filters are often used for PE prophylaxis when chemical DVT prophylaxis fails or is contraindicated. The following Department of Defense (DoD) Joint Trauma System (JTS) Clinical Practice Guideline (CPG) discusses the current recommendations for the prevention of DVT and PE including the use of inferior vena cava filters (IVCFs).

Evaluation of nonpermanent inferior vena cava filter placement in patients with deep venous thrombosis after lower extremity fracture: A single-center retrospective study

OBJECTIVE

To investigate nonpermanent inferior vena cava (IVC) filter in the prevention of perioperative pulmonary embolism (PE) in patients of lower extremity and/or pelvic bone fracture with deep vein thrombosis (DVT).

METHODS

Lower extremity or pelvic bone fracture patients with lower extremity DVT hospitalized in our hospital from January 2003 to October 2014 were retrospectively analyzed. Data was analyzed for age, gender, position of fracture, position of proximal of thrombosis, indications of placement, complications, retrieval rate, and rate of entrapped filter clot. Patients who underwent IVC filter placement were selected as the filter group. The patients who did not perform IVC filter placement after 2008 and the cases between January 2003 and December 2007 were selected as control group 1 and control group 2, respectively. The incidence of perioperative symptomatic PE and mortality were analyzed.

RESULTS

A total of 2763 cases complicated with DVT underwent orthopedic surgery between January 2003 and October 2014. 823 nonpermanent filters were inserted. All filters were successfully deployed with no major complications. After a mean 14.2 days indwelling time, all of temporary filters were removed. Retrieval was attempted in 556 patients with retrievable filters and was successful in 545 (98%); mean indwelling time was 16.3 days. The total retrieval rate was 90%. The incidence of PE in the filter group was significantly lower compared with the two control groups. Among the patients who received chemical anticoagulant therapy, the incidence of PE in filter group, control group 1 and control group 2 were 0.14%, 1.60% and 2.10%, respectively. The incidence of PE in filter group was also significant lower compared with control groups.

CONCLUSION

Nonpermanent IVC filter placement seems like to be a safe and effective method for preventing perioperative symptomatic and fatal PE in bone fracture patients with DVT in the present retrospective study.

Deep vein thrombosis and pulmonary embolism in the military patient

OBJECTIVES

Venous thromboembolism (VTE), encompassing deep vein thrombosis and pulmonary embolism, is a common, potentially lethal condition and a cause of long-term morbidity and functional limitation. This paper is a clinical review focused on military epidemiology, evidence-based recommendations for prevention, diagnosis and management of VTE and occupational considerations in a military population.

METHODS

A literature review was conducted through Pubmed and Embase for systematic reviews, meta-analyses and clinical trials relating to VTE. Guidelines from the National Institute for Health and Care Excellence, British Thoracic Society and the American College of Chest Physicians were reviewed and recommendations considered.

RESULTS

Acute morbidity from VTE can range from limb pain and swelling to life-threatening cardiovascular compromise. Long-term sequelae include postthrombotic syndrome, chronic thrombosis and pulmonary hypertension. Diagnosis should follow a validated pathway depending on the patient's prerest probability. The management of the condition should vary with attention to risk stratification.

DISCUSSION

Prompt initiation of anticoagulation reduces symptoms, rates of recurrent VTE and death but treatment must be balanced against the risk of major haemorrhage. Military operations expose personnel to a unique combination of risk factors for VTE and operating in austere environments can increase the challenge of diagnosis, prognostication and management. Furthermore, there are implications for troop attrition, operational readiness and return to work.

Emergency radiology: Peripheral vascular injuries

There has been a growing role for both diagnostic and interventional radiology (IR) in all types of trauma affecting different areas of the body, with imaging becoming an integral part of the multidisciplinary approach to modern trauma care. This article is intended to assess the role of radiology in peripheral trauma and highlight some of the indications, contraindications and treatment options available. It will also touch upon other associated problems encountered by the trauma patient in particular the increased risk of thromboembolic disease. We review some of the common peripheral vascular injuries in our experience in a large trauma hospital.

Decision analysis of retrievable inferior vena cava filters in patients without pulmonary embolism

BACKGROUND

Retrievable filters are increasingly implanted for prophylaxis in patients without pulmonary embolism (PE) but who may be at transient risk. These devices are often not removed after the risk of PE has diminished. This study employs decision analysis to weigh the risks and benefits of retrievable filter use as a function of the filter's time in situ.

METHODS

Medical literature on patients with inferior vena cava (IVC) filters and a transient risk of PE were reviewed. Weights reflecting relative severity were assigned to each adverse event. The risk score was defined as weight × occurrence rate and combines the frequency and severity for each type of adverse event. The value function in the decision model combines the following risks: (1) risk in situ; (2) risk of removal, and (3) relative risk without filters. A decreasing net risk score represents a net expected benefit, and an increasing net risk score indicates the expected harm outweighs the expected benefit.

RESULTS

The net risk score reaches its minimum between day 29 and 54 postimplantation. This is consistent with an increasing net risk associated with continued use of retrievable IVC filters in patients with transient, reversible risk of PE. The results were insensitive to reasonable variations in the assessed weights and adverse event occurrence rates.

CONCLUSIONS

For patients with retrievable IVC filters in whom the transient risk of PE has passed, quantitative decision analysis suggests the benefit/risk profile begins to favor filter removal between 29 and 54 days after implantation.

Inferior vena cava filters: Some evidence from the past and a look to the future

Venous thromboembolism is a national health concern. Up to 58% of patients suffering from major multisystem trauma will experience venous thromboembolism if no measures are taken to prevent it. Of those, 10% to 30% will be fatal. The appropriate use of lower extremity compression, anticoagulation, and the use of inferior vena cava (IVC) filters has helped reduce the overall morbidity and mortality from this disease. The development of lower-profile devices and the ability to retrieve IVC filters has led to a liberalization of their use. The majority of the filters used today have achieved U.S. Food and Drug Administration approval through the 510K mechanism (approval based on prior similar devices rather than safety studies of the proposed device), and therefore, no rigorous investigations have been performed on them. Initially seeming safe, a recent increase in reports of filter migration, vena cava perforation, and vena cava thrombosis has prompted the Food and Drug Administration to ask for more information on their patterns of use, safety, efficacy, and retrievability. This report details some of the available data on the subject of IVC filters and the discussion surrounding the topic of prophylactic IVC filters in trauma patients.

Inferior vena cava filters for primary prophylaxis: when are they indicated?

Over the past several years there has been a rapid increase in the number of inferior vena cava (IVC) filters placed for primary thromboprophylaxis. Increased use has occurred in settings where other methods of thromboprophylaxis are viewed to be inadequate, technically challenging, or that place patients at an unacceptably high bleeding risk. These clinical services include trauma, bariatric surgery, neurosurgery, cancer, intensive care unit populations, and patients with a relative contraindication to anticoagulation. We review the studies to date addressing filter placement for these indications. Although preliminary data are promising, the patient populations most likely to benefit from prophylactic IVC filter placement have not been well defined, and randomized studies demonstrating efficacy have not been conducted. Moving forward, it will be critical to accomplish these two tasks if IVC filters are to continue to have a role in primary thromboprophylaxis.

Vena cava filter practices of a regional vascular surgery society

BACKGROUND

Vena cava filter (VCF) use in the United States has increased dramatically with prophylactic indications for placement and the availability of low-profile retrievable devices, which are overtaking the filter market. We surveyed the practice patterns of a large group of vascular surgeons from a regional vascular surgery society to see whether they mirrored current national trends.

METHODS

A 17-question online VCF survey was offered to all members of the Southern Association of Vascular Surgery. The responses were analyzed using the χ(2) goodness of fit tests.

RESULTS

Of the 276 members surveyed, 126 (46%) responded, with 118 (93%) indicating that they placed filters during their practice. Highly significant differences were identified with each question (at least P < 0.002). Regarding the inferior vena cava, the preferred permanent filters were the Greenfield (31%), the TrapEase (15%), the Vena Tech (5%), and a variety of retrievable devices (49%). Fifty percent of the respondents placed retrievable filters selectively; 26% always placed them; and 24% never did. Filters were placed for prophylactic indications <50% of the time by 63% of the respondents. Overall, retrievable filters (when not used as permanent filters) were removed <25% of the time by 64% of the respondents and <50% of the time by 78% of the respondents. The femoral vein was the preferred access site for 84% of the respondents. Major complications were few but included filter migration to the atrium (one), atrial perforation (one), abdominal pain requiring surgical filter removal (two), inferior vena cava thrombosis (12 vena cava thrombosis--4 due to TrapEase filters), strut fracture with embolization to heart or lungs (three Bard retrievable filters), and severe tilting precluding percutaneous retrieval and protection from pulmonary emboli (8 filters with severe tilt--7 of which were Bard). Of the respondents, 59% had never placed a superior vena cava filter, and 28% had placed five or fewer.

CONCLUSIONS

Although VCF insertion overall appears safe, some complications are specific to biconical and certain retrievable filters. Given the low removal rate and lack of long-term experience with retrievable filters, routine use of these devices as permanent filters should be questioned. If used on a temporary basis, there should be a plan for filter removal at the time of implantation.

Dedicated Tracking of Patients with Retrievable Inferior Vena Cava Filters Improves Retrieval Rates

Retrievable IVC filters (R-IVCF) are associated with multiple complications, including filter migration and deep venous thrombosis. Unfortunately, most series of R-IVCF show low retrieval rates, often due to loss to follow-up. This study demonstrates that actively tracking R-IVCF improves retrieval. Trauma patients at one institution with R-IVCF placed between January 2007 and January 2011 were tracked in a registry with a goal of retrieval. These were compared to a control group who had R-IVCF placed previously (December 2005 to December 2006). Outcome measures include filter retrieval, retrieval attempts, loss to follow-up, and time to filter retrieval. We compared 93 tracked patients with R-IVCF with 20 controls. The baseline characteristics of the groups were similar. Tracked patients had significantly higher rates of filter retrieval (60% vs 30%, P = 0.02) and filter retrieval attempts (70% vs 30%, P = 0.002) and were significantly less likely to be lost to follow-up (5% vs 65%, P < 0.0001). Time to retrieval attempt was 84 days in the registry versus 210 days in the control group, which trended towards significance ( P = 0.23). Tracking patients with R-IVCF leads to improved retrieval rates, more retrieval attempts, and decreased loss to follow up. Institutions should consider tracking R-IVCF to maximize retrieval rates.

Improved recovery of prophylactic inferior vena cava filters in trauma patients: the results of a dedicated filter registry and critical pathway for filter removal

BACKGROUND

Temporary inferior vena cava filters (IVCF) are uniquely suited for trauma patients in whom the high risk of venous thromboembolism is transient. Currently, few "retrievable filters" are actually retrieved, with most published series documenting a retrieval rate between 20% and 50%. We sought to determine whether we could achieve a higher rate of retrieval with an improved process of care.

METHODS

All permanent and temporary filters were entered prospectively into a dedicated filter registry. Within 60 days of filter placement, all temporary filter patients were contacted by a trauma case manager to evaluate ongoing venous thromboembolism risk. Low-risk patients were then evaluated by radiology for removal of the IVCF. If appropriate, removal of the IVCF was scheduled. Initial contacts with patients were made by telephone. If unsuccessful with phone contact, family members, rehabilitation facility, and social work were all contacted to obtain the most recent phone number and address. A follow-up letter was sent to the patient with follow-up visit instructions. Finally, if prior contact measures did not work, a certified letter was sent to the last known address.

RESULTS

Between 2006 and 2009, of 7,949 trauma admissions, 420 (5.2%) met indications for filter placement. Of those, 160 were available for removal and 94 were successfully removed (59%).

CONCLUSIONS

A retrieval rate of 59% can be achieved with an explicit process of care emphasizing disciplined follow-up.

LEVEL OF EVIDENCE

III.

The use of prophylactic inferior vena cava filters in trauma patients: a systematic review

INTRODUCTION

Pulmonary embolisms (PE) are an often preventable cause of late morbidity and mortality after trauma. Although there is evidence for the use of therapeutic inferior vena cava (IVC) filters (defined as IVC filters implanted in those with proven deep venous thrombosis [DVT] in order to prevent PE), there is not as much evidence to support the use of prophylactic IVC filters. Thus, we undertook a systematic review of the literature to assess the following in prophylactic IVC filters: efficacy in PE reduction, prevalence of filter-related complications and the indications for use.

MATERIALS AND METHODS

After screening 249 studies, 24 studies met inclusion criteria for qualitative synthesis.

RESULTS

Overall, the literature is supportive of the use of prophylactic IVC filters in high-risk poly-trauma patients who may have contraindications to DVT prophylaxis. Filter-associated complications are uncommon and, when they do occur, tend to be of limited clinical significance. Limited data, mostly in the form of case series, supports a reduction in PE and PE-related mortality. There has been increasing use of retrievable filters as well as the ability to safely retrieve them at longer intervals.

CONCLUSION

Despite the addition of a few matched-control studies, the literature is still plagued by a lack of high quality data, and therefore the true efficacy of prophylactic IVC filters for prevention of PE in trauma patients remains unclear. Further studies are required to determine the true role of prophylactic IVC filters in trauma patient.

Optional inferior vena cava filters in the trauma patient

Trauma patients are at exceedingly high risk of development of venous thromboembolism (VTE) including deep venous thrombosis and pulmonary embolism (PE). The epidemiology of VTE in trauma patients is reviewed. PE is thought to be the third major cause of death after trauma in those patients who survive longer than 24 hours after onset of injury. In fact, patients recovering from trauma have the highest rate of VTE among all subgroups of hospitalized patients. Various prophylactic and surveillance methods have been evaluated and found helpful in certain situations, but VTE complications can occur despite such measures. Therapeutic and prophylactic uses of inferior vena cava (IVC) filters in trauma patients are reviewed. Prophylactic IVC filter use is revealed to be a controversial subject with valid arguments on both sides of the issue. With the lack of prospective randomized trials of IVC filter use in trauma, it is impossible to make evidence-based recommendations. Unfortunately, two sets of guidelines are available for insertion of filters in trauma patients, with conflicting recommendations. The introduction of retrievable IVC filters seems to offer a unique solution for VTE protection in the trauma patient population, which often consists of younger members of our population. Lastly, current generations of FDA-approved retrieval filters are discussed.

Popliteal artery repair in massively transfused military trauma casualties: a pursuit to save life and limb

BACKGROUND

Popliteal artery war wounds can bleed severely and historically have high rates of amputation associated with ligation (72%) and repair (32%). More than before, casualties are now surviving the initial medical evacuation and presenting with severely injured limbs that prompt immediate limb salvage decisions in the midst of life-saving maneuvers. A modern analysis of current results may show important changes because previous limb salvage strategies were limited by the resuscitation and surgical techniques of their eras. Because exact comparisons between wars are difficult, the objective of this study was to calculate a worst-case (a pulseless, fractured limb with massive hemorrhage from popliteal artery injury) amputation-free survival rate for the most severely wounded soldiers undergoing immediate reconstruction to save both life and limb.

METHODS

We performed a retrospective study of trauma casualties admitted to the combat support hospital at Ibn Sina Hospital in Baghdad, Iraq, between 2003 and 2007. US military casualties requiring a massive transfusion (> or = 10 blood units transfused within 24 hours of injury) were identified. We extracted data on the subset of casualties with a penetrating supra or infrageniculate popliteal arterial vascular injury. Demographics, injury mechanism, Injury Severity Score, tourniquet use, physiologic parameters, damage control adjuncts, surgical repair techniques, operative time, and outcomes (all-cause 30-day mortality, amputation rates, limb salvage failure, and graft patency) were investigated.

RESULTS

Forty-six massively transfused male casualties, median age 24 years (range, 19-54 years; mean Injury Severity Score, 19 +/- 8.0), underwent immediate orthopedic stabilization and vascular reconstruction. There was one early death. The median operative time for the vascular repairs was 217 minutes (range, 94-630 minutes) and included all damage control procedures. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and 9 venous injuries. Amputations (transtibial or transfemoral) were considered limb salvage failures (14 of 48, 29.2%) and were grouped as immediate (< or = 48 hours, 5), early (>48 hours and < or = 30 days, 6), or late (>30 days, 3). Limb losses were from graft thrombosis, infection, or chronic pain. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and nine venous injuries. For a median follow-up (excluding death) of 48 months (range, 23-75 months), the amputation-free survival rate was 67%.

CONCLUSIONS

This study, a worst-case study, showed comparable results to historical controls regarding limb salvage rates (71% for Iraq vs. 56-69% for the Vietnam War). Thirty-day survival (98%), 4-year amputation-free survival (67%), and complication-free rates (35%) fill knowledge gaps. Guidelines for managing popliteal artery injuries show promising results because current resuscitation practices and surgical care yielded similar amputation rates to prior conflicts despite more severe injuries. Significant transfusion requirements and injury severity may not indicate a life-over-limb strategy for popliteal arterial repairs. Future studies of limb salvage failures may help improve casualty care by reducing the complications that directly impact amputation-free survival.

[Vena cava filters in trauma patients]

BACKGROUND

The introduction of removable inferior vena cava filters (IVCF) has created new options for the prevention of pulmonary embolisms in surgical trauma patients. We have observed increasing use in trauma patients.

PATIENTS AND METHODS

A retrospective analysis was carried out of 49 trauma patients out of 85 who received IVCFs at our level 1 trauma centre in 2008.

RESULTS

The indications for IVCF placement were multiple trauma in 33 patients, severe head injury in 13 and spinal injury in 3 patients. Of the patients 34 underwent successful removal, 11 (22%) patients had had no retrieval attempt by December 2009 and attempts at removal were unsuccessful in 3 patients. The mean age of the patients was 33.3 years.

CONCLUSION

In 2008 the vast majority of IVCFs were inserted for prophylaxis in trauma patients. To increase the number of retrieved IVCFs, responsibility for the removal should be clarified in every hospital. The indications, advantages, safety and also the design of IVCFs are still under debate. A randomized controlled trial is needed to determine the appropriate use and indications for this potentially useful device in trauma patients.

Thromboprophylaxis after multiple trauma: what treatment and for how long?

A review of current literature discussing thromboprophylaxis in the multiple-trauma patient to provide insight on the type of treatment and its duration of use. AMEDLINE search was conducted in May 2009 using keywords associated with thromboprophylactic measures in multiple-trauma patient care, including inferior vena cava (IVC) filters, mechanical-compression devices and anticoagulants. Abstracts were evaluated for relevance to this study and full-text articles were then examined individually. Fourteen full text articles were evaluated including guidelines published by the American College of Chest Physicians (ACCP) and the Eastern Association for the Surgery of Trauma (EAST) and other studies dealing with multiple-trauma patients, including those in hip-fracture surgery, lower-leg trauma and head trauma. Limited research has been performed for the multiple-trauma patient and recommendations regarding the type of treatment and its duration of use cannot be suggested beyond what has been extrapolated from existing trauma and major surgery patients. IVC filters, mechanical compression devices and anticoagulants therefore remain the standard, but their duration of use in the multiple-trauma patient is not well described. New oral anticoagulants that inhibit factor Xa or thrombin directly show promising qualities but have not been evaluated for multiple-trauma applications. Therefore, optimal thromboprophylaxis and its duration after multiple trauma is largely based on rational, clinical decision making on a case-by-case basis.