A Comparison of Clinical Outcomes with Retrievable and Permanent Inferior Vena Cava Filters

Inferior Vena Cava Filter in Cancer-Associated Thrombosis: A Vade Mecum for the Treating Physicians: A Narrative Review

Cancer is a remarkable prothrombotic disease, and cancer-associated thrombosis acts as a dreadful omen for poor prognosis. The cornerstone of venous thromboembolism therapy is anticoagulation; however, in patients with venous thromboembolism who are not suitable for anticoagulation (contraindication, failure, or complication), the inferior vena cava filter appears a valuable option in the therapeutic arsenal. The recently heightened trend of steady rise in filter placement mirrors the spread of retrievable devices, together with improvements in physicians' insertion ability, medico-legal issue, and novel and fewer thrombogenic materials. Nevertheless, the exact role of the inferior vena cava filter in cancer has yet to be endorsed due to a dearth of robust evidence. Indeed, data that support the inferior vena cava filter are weak and even controversial, resulting in discrepancies in the interpretation and application of guidelines in daily practice. In this narrative review, we aim at clarifying the state of the art on inferior vena cava filter use in malignancies. Furthermore, we provide a feasible, conclusive 4-step algorithm for the treating physicians in order to offer a practical strategy to successfully employ the inferior vena cava filter as a priceless device in the current armamentarium against cancer.

Inferior vena cava filters: Concept review and summary of current guidelines

Anticoagulation is the first-line approach in the prevention and treatment of pulmonary embolism. In some instances, however, anticoagulation fails, or cannot be administered due to a high risk of bleeding. Inferior vena cava filters are metal alloy devices that mechanically trap emboli from the deep leg veins halting their transit to the pulmonary circulation, thus providing a mechanical alternative to anticoagulation in such conditions. The Greenfield filter was developed in 1973 and was later perfected to a model that could be inserted percutaneously. Since then, this model has been the reference standard. The current class I indication for this device includes absolute contraindication to anticoagulants in the presence of acute thromboembolism and recurrent thromboembolism despite adequate therapy. Additional indications have been more recently proposed, due to the development of removable filters and of progressively less invasive techniques. Although the use of inferior vena cava filters has solid theoretical advantages, clinical efficacy and adverse event profile are still unclear. This review analyzes the most important studies related to such devices, open issues, and current guideline recommendations.

Inferior Vena Cava Filters: An Overview

For patients with existing venous thromboembolisms (VTEs), anticoagulation remains the standard of care recommended across multiple professional organizations. However, for patients who developed a deep venous thrombosis (DVT) and/or a pulmonary embolism and cannot tolerate anticoagulation, inferior vena cava (IVC) filters must be considered among other alternative treatments. Although placement of a filter is considered a low-risk intervention, there are important factors and techniques that surgeons and interventionalists should be aware of and prepared to discuss. This overview covers the basics regarding the history of filters, indications for placement, associated risks, and techniques for difficult removal.

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.

Population-Based Disparities in Inferior Vena Cava Filter Procedures Among Medicare Enrollees With Acute Venous Thromboembolism

PURPOSE

Venous thromboembolism (VTE) imposes a significant clinical and financial burden on patients and society. Inferior vena cava filters (IVCFs) are considered for patients with absolute contraindications or failures of anticoagulation. However, studies examining the population-based disparities of IVCF placement and retrieval are limited. The association between patient and clinical characteristics in the likelihood of and time to IVCF placement and retrievals in a nationally representative cohort was examined.

METHODS

Medicare patients aged ≥65 years with index VTE claims between 2015 and 2018 were followed through 2019 to identify IVCF placements and retrievals. Rates were compared using survival analysis methods.

RESULTS

Of the 516,978 patients with VTE diagnoses, 5,864 (1.1%) had IVCFs placed, and 1,884 (32.1%) of those underwent retrieval procedures. Placement and retrieval rates varied significantly by demographics, comorbidity burden, and geographic region. From Cox regression, older age (hazard ratio [HR], 1.26; P < .0001), higher baseline comorbidity (Elixhauser) score (HR, 1.07; P < .0001), and outpatient (vs inpatient) site of VTE service (HR, 2.11; P < .0001) were associated with increased frequency of IVCF placement. The rate of retrieval was significantly lower for men (HR, 0.83; P = .0393), patients with higher comorbidity scores (HR, 0.95; P = .0037), and those with outpatient (vs inpatient) VTE sites of service (HR, 0.77; P = .0173). Neither facility- nor county-level characteristics were significantly associated with placements or retrievals.

CONCLUSIONS

This large cohort of Medicare beneficiaries with newly diagnosed VTE demonstrated inequities in IVCF placement and retrieval.

Long-Term Outcomes in Patients with Not-Retrieval Inferior Vena Cava Filter Under Anticoagulation

Since permanent inferior vena cava (IVC) filters increase deep vein thrombosis (DVT), filter retrieval should be performed as possible. Despite the guideline recommendation, IVC filters are not always retrieved in clinical practice. To date, many patients with not-retrieval IVC filters have been prescribed anticoagulant therapy, but the long-term prognosis, including venous thromboembolism (VTE) and bleeding events, remains unknown. In this study, 195 patients who underwent IVC filter implantation between 2006 and 2017 at 3 institutions in Niigata City have been investigated about their deaths, VTE recurrence, and bleeding events. After peaking 2009, the number of IVC filter implantation gradually decreased. During observational period, there were 158 patients with not-retrieval IVC filters (the overall retrieval rate of 19.0%). The not-retrieval group included significantly older and more patients with cancer compared to the retrieval group. Anticoagulation therapy was continued in 88% of the not-retrieval group. During a mean follow-up of 5.0 years, 6 symptomatic DVT events associated with inadequate control of anticoagulation and 13 bleeding events were observed. A total of 52 patients died and only the presence of cancer was prognostic risk factor. Although long-term anticoagulation therapy may be associated with bleeding events, there were few recurrent VTE under optimal anticoagulation. It is anticipated that even if the IVC filter cannot be retrieved, appropriate anticoagulation is useful for prevention of DVT recurrence despite the risk of bleeding.

Comparison of Retrievability and Indwelling Complications of Celect and Denali Infrarenal Vena Cava Filters: A Randomized, Controlled Trial

PURPOSE

To compare the Celect and Denali filters in terms of complex filter retrieval and indwelling complications after a 2-month indwelling time.

MATERIALS AND METHODS

In this prospective, randomized trial, 153 subjects were assessed for eligibility between May 2016 and July 2018. A total of 136 participants were randomly assigned to receive either Celect (n = 68) or Denali (n = 68) filter placement in the infrarenal inferior vena cava. Tilt angles at placement and retrieval and rates of overall filter retrieval, indwelling complication, and complex retrieval were compared.

RESULTS

Of 136 participants (mean age, 62 ± 12.8 years, 55 male), 24 (17.6%) were lost to follow-up. The mean indwelling time of filter was 60.4 ± 7 days and there was no significant difference in the baseline characteristics between the two groups. Filter retrieval was successful in all participants (112/112, 100%). Significantly higher rates of filter tilt > 15° (n = 8) and strut penetration (n = 14) were found with the Celect filter than with the Denali filter (1 significant tilt and 1 penetration) (P = 0.033 and 0.001, respectively). No filter fractures were observed and there was no significant difference in tip embedment, filter fracture, filter migration, or mean fluoroscopy times. There were 3 cases of complex retrieval (1 for Denali vs. 2 for Celect, P = 0.500), for which the loop-snare technique was used.

CONCLUSION

Denali filters demonstrated significantly lower rates of tilt angle > 15° and strut penetration. However, there was no significant difference in the complex filter retrieval rate between the Celect and Denali filters.

Why optional inferior vena cava filters are not always retrieved? A real world 19 years experience in a Swiss tertiary care university hospital

BACKGROUND

inferior vena cava filters (IVCF) are widely used to prevent thromboembolic events in patients not suitable for anticoagulation (AC). Although new generations of filters are optional and therefore retrievable, most of them become permanent. Aim of our study was to evaluate real life IVCF management in a tertiary hospital including retrieval rates and reasons for permanent filtering.

MATERIALS AND METHODS

Electronic charts from patients receiving IVCF in a Swiss university hospital, during 1999-2017, were retrospectively identified. Patients were classified in two groups, according to filter retrieval (RG) or not (NRG). Type and reasons of filter placement were assessed. Retrieval, complications, and mortality rates were calculated. Reasons of non-retrieval were analyzed.

RESULTS

920 patients received an IVCF during 1999-2017. Filters were retrieved in 372 patients (40.65%). Subjects in the NRG were significantly older, more chronically ill, and presented higher mortality rate at 12 months following filter insertion (29.60% vs. 4.30%; p < 0.001). Reasons for non-retrieval included lack of follow-up (22.34%), persistent contraindications to AC (20.51%), technical issues (17.40%), and severe morbidity with short life expectancy (17.22%). Overall, complication rates after filter placement was 18.58%. Most reported complication was filter thrombosis (15.60%).

CONCLUSIONS

In a real life setting, optional IVCF are still too often left in place indefinitely. Need for a systematic follow-up to ensure prompt filter retrieval is warranted. IVCF are not retrieved mostly in chronically and more severely ill patients, likely accounting for higher mortality in these subjects.

Permanent inferior vena cava filters offer greater expected patient utility at lower predicted cost

OBJECTIVE

Retrievable inferior vena cava (IVC) filters were first approved for use in the United States in 2003 to address the long-term complications of migration, thrombosis, fracture, and perforation observed with permanent IVC filter implantation. Although Food and Drug Administration approval of retrievable IVC filters includes permanent implantation, the incidence of complications from long-term implantation appears to be greater than that reported with existing permanent IVC filters. Also, only a small fraction of such retrievable IVC filters are ever retrieved. The purpose of the present study was to determine the threshold retrieval rate at which the use of retrievable IVC filters could be justified.

METHODS

A Markov decision tree was constructed comparing retrievable and permanent IVC filters regarding their effectiveness and cost. A review of the reported data provided outcome probabilities, and the Tufts Medical Center Cost-Effectiveness Analysis Registry was the source of the utility values for the various potential outcomes. Medicare reimbursement rates served as a proxy for costs. A sensitivity analysis was performed for various parameters, primarily to determine the retrieval rate threshold at which the use of retrievable IVC filters would outperform the use of permanent IVC filters.

RESULTS

Base case analysis demonstrated a greater predicted effectiveness for permanent compared with retrievable IVC filter implantation (5.41 quality-adjusted life-years [QALY] vs 5.33 QALY) at a lower cost ($2070 vs $4650). Monte Carlo simulation at 10,000 iterations confirmed the expected utility (5.4 ± 3.0 QALY vs 5.3 ± 3.0 QALY; P = .0002) and cost ($1900 ± $7400 vs $4800 ± 9900; P < .0001) to be statistically superior for permanent IVC filters. A sensitivity analysis for the filter retrieval rate demonstrated that the strategy of using a retrievable IVC filter was never preferable for utility or cost. The superiority of permanent IVC filter placement for effectiveness and cost persisted, regardless of anticipated patient-predicted annual mortality. A two-way sensitivity analysis for both IVC filter removal rate and annual patient mortality confirmed the superiority of permanent IVC filter placement at all levels.

CONCLUSIONS

The predicted effectiveness of permanent IVC filters was greater and the predicted cost lower than those for retrievable IVC filters, regardless of the IVC filter retrieval rate. This interpretation of existing reported data using Markov decision analysis modeling supports the argument that unless the long-term complication rate of retrievable IVC filters can be significantly improved, their use should be abandoned in favor of currently available permanent IVC filters.

A 7-year retrospective review of the technical success of the "low-profile" hangman technique for complicated inferior vena cava (IVC) filter retrievals

PURPOSE

We aimed to assess the safety and effectiveness of a modified low-profile hangman technique.

METHODS

We performed a retrospective review of all filter retrieval procedures performed at a major trauma center, from 2012 to 2019. Records were reviewed for patient demographics, device type, device dwell time, device tilt, embedded hook, success of device retrieval, evidence of caval injury and occurrence of complications.

RESULTS

From 2012 to 2019 there were 473 filter retrieval attempts. An advanced technique was documented in 66 (14%). The low-profile hangman technique alone was documented in 23 procedures (5% of all procedures, 35% of advanced technique procedures). Average screening time was 28 minutes. At the time of retrieval attempt, 9 patients (41%) were anticoagulated. The hangman technique was employed as isolated maneuver in 23 patients and was successful on initial attempt in 22 cases (96%). The average dwell time of filters retrieved by the hangman technique was 228 days (range, 40-903 days; median, 196 days). No procedure-related complications occurred.

CONCLUSION

The retrieval of IVC filters is an important part of offering an IVC filter service. Advanced techniques to retrieve caval filters are multiple, and the risk of complications is increased in these cases. We demonstrate the safety and effectiveness of a new modified and lower-profile hangman technique. This new technique could be performed with only an 11 French venous access sheath using off-the-shelf equipment and it remains a cost-effective approach to complex filter retrieval.

Use and Removal of Inferior Vena Cava Filters in Patients With Acute Brain Injury

Background

Few data exist regarding the rate of inferior vena cava (IVC) filter retrieval among brain-injured patients.

Methods

We conducted a retrospective cohort study using inpatient claims between 2009 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients aged ≥65 years who were hospitalized with acute brain injury. The primary outcome was the retrieval of IVC filter at 12 months and the secondary outcomes were the association with 30-day mortality and 12-month freedom from pulmonary embolism (PE). We used Current Procedural Terminology codes to ascertain filter placement and retrieval and International Classification of Diseases, Ninth Revision, Clinical Modification codes to ascertain venous thromboembolism (VTE) diagnoses. We used standard descriptive statistics to calculate the crude rate of filter placement. We used Cox proportional hazards analysis to examine the association between IVC filter placement and mortality and the occurrence of PE after adjustment for demographics, comorbidities, and mechanical ventilation. We used Kaplan-Meier survival statistics to calculate cumulative rates of retrieval 12 months after filter placement.

Results

Among 44 641 Medicare beneficiaries, 1068 (2.4%; 95% confidence interval [CI], 2.3%-2.5) received an IVC filter, of whom 452 (42.3%; 95% CI, 39.3%-45.3) had a diagnosis of VTE. After adjusting for demographics, comorbidities, and mechanical ventilation, filter placement was not associated with a reduced risk of mortality (hazard ratio [HR], 1.0; 95% CI, 0.8-1.3) regardless of documented VTE. The occurrence of pulmonary embolism at 12 months was associated with IVC filter placement (HR, 3.19; 95% CI, 1.3-3.3) in the most adjusted model. The cumulative rate of filter retrieval at 12 months was 4.4% (95% CI, 3.1%-6.1%); there was no significant difference in retrieval rates between those with and without VTE.

Conclusions

In a large cohort of Medicare beneficiaries hospitalized with acute brain injury, IVC filter placement was uncommon, but once placed, very few filters were removed. IVC filter placement was not associated with a reduced risk of mortality and did not prevent future PE.

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).

A comparative CFD study of four inferior vena cava filters

Computational fluid dynamics was used to simulate the flow of blood within an inferior vena cava (IVC) geometry model that was reconstructed from computed tomography images obtained from a real patient. The main novelty of the present work is that we simulated the implantation of 4 different filter models in this realistic IVC geometry. We considered different blood flow rates in the range between V_in =20 and V_in =80 cm³ /s, and all simulations were performed with both the Newtonian and a non-Newtonian model for the blood viscosity. We compared the hemodynamics performance of the different filter models, and we paid a special attention to the total drag force, F_d , exerted by the blood flow on the filter surface. This force is the sum of 2 contributions: the viscous skin friction force, which was found to be roughly proportional to the filter surface area, and the pressure force, which depended on the particular filter geometry design. The F_d force is relevant because it must be balanced by the total force exerted by the filter hooks/struts on the IVC wall at the attachment locations. For the highest V_in value investigated, the variation in F_d among filters was from 116 to 308 dyne. We also showed how the present results can be extrapolated to obtain good estimates of the drag forces if the blood viscosity levels change, ie, if the patient with a filter implanted is treated with anticoagulant therapy.

Interventional Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a serious and prevalent cause of vascular disease. Nevertheless, optimal treatment for many phenotypes of PE remains uncertain. Treating PE requires appropriate risk stratification as a first step. For the highest-risk PE, presenting as shock or arrest, emergent systemic thrombolysis or embolectomy is reasonable, while for low-risk PE, anticoagulation alone is often chosen. Normotensive patients with PE but with indicia of right heart dysfunction (by biomarkers or imaging) constitute an intermediate-risk group for whom there is controversy on therapeutic strategy. Some intermediate-risk patients with PE may require urgent stabilization, and ≈10% will decompensate hemodynamically and suffer high mortality, though identifying these specific patients remains challenging. Systemic thrombolysis is a consideration, but its risks of major and intracranial hemorrhages rival overall harms from intermediate PE. Multiple hybrid pharmacomechanical approaches have been devised to capture the benefits of thrombolysis while reducing its risks, but there is limited aggregate clinical experience with such novel interventional strategies. One method to counteract uncertainty and generate a consensus multidisciplinary prognostic and therapeutic plan is through a Pulmonary Embolism Response Team, which combines expertise from interventional cardiology, interventional radiology, cardiac surgery, cardiac imaging, and critical care. Such a team can help determine which intervention-catheter-directed fibrinolysis, ultrasound-assisted thrombolysis, percutaneous mechanical thrombus fragmentation, or percutaneous or surgical embolectomy-is best suited to a particular patient. This article reviews these various modalities and the background for each.

Vena Cava Filter Use in Trauma and Rates of Pulmonary Embolism, 2003-2015

Importance

Vena cava filter (VCF) placement for pulmonary embolism (PE) prophylaxis in trauma is controversial. Limited research exists detailing trends in VCF use and occurrence of PE over time.

Objective

To analyze state and nationwide temporal trends in VCF placement and PE occurrence from 2003 to 2015 using available data sets.

Design, Setting, and Participants

A retrospective trauma cohort study was conducted using data from the Pennsylvania Trauma Outcome Study (PTOS) (461 974 patients from 2003 to 2015), the National Trauma Data Bank (NTDB) (5 755 095 patients from 2003 to 2014), and the National (Nationwide) Inpatient Sample (NIS) (24 449 476 patients from 2003 to 2013) databases.

Main Outcomes and Measures

Temporal trends in VCF placement and PE rates, filter type (prophylactic or therapeutic), and established predictors of PE (obesity, pregnancy, cancer, deep vein thrombosis, major procedure, spinal cord paralysis, venous injury, lower extremity fracture, pelvic fracture, central line, intracranial hemorrhage, and blood transfusion). Prophylactic filters were defined as VCFs placed before or without an existing PE, while therapeutic filters were defined as VCFs placed after a PE.

Results

Of the 461 974 patients in PTOS, the mean (SD) age was 47.2 (26.4) and 61.6% (284 621) were men; of the 5 755 095 patients in NTDB, the mean age (SD) was 42.0 (24.3) and 63.7% (3 666 504) were men; and of the 24 449 476 patients in NIS, the mean (SD) age was 58.0 (25.2) and 49.7% (12 160 231) were men. Of patients receiving a filter (11 405 in the PTOS, 71 029 in the NTDB, and 189 957 in the NIS), most were prophylactic VCFs (93.6% in the PTOS, 93.5% in the NTDB, and 93.3% in the NIS). Unadjusted and adjusted temporal trends for the PTOS and NTDB showed initial increases in filter placement followed by significant declines (unadjusted reductions in VCF placement rates, 76.8% in the PTOS and 53.3% in the NTDB). The NIS demonstrated a similar unadjusted trend, with a slight increase and modest decline (22.2%) in VCF placement rates over time; however, adjusted trends showed a slight but significant increase in filter rates. Adjusted PE rates for the PTOS and NTDB showed significant initial increases followed by slight decreases, with limited variation during the declining filter use periods. The NIS showed an initial increase in PE rates followed by a period of stagnation.

Conclusions and Relevance

Despite a precipitous decline of VCF use in trauma, PE rates remained unchanged during this period. Taking this association into consideration, VCFs may have limited utility in influencing rates of PE. More judicious identification of at-risk patients is warranted to determine individuals who would most benefit from a VCF.

The Impact of Cancer on the Clinical Outcome of Patients After Inferior Vena Cava Filter Placement: A Retrospective Cohort Study

OBJECTIVES

Inferior vena cava (IVC) filters are placed to prevent pulmonary embolism, however, some studies have suggested that IVC filters are associated with exacerbated risks of deep vein/IVC thrombosis in cancer patients. The purpose of this study is to determine if cancer patients develop higher than expected rates of venous thromboembolism complications after filter placement compared with noncancer patients.

MATERIALS AND METHODS

A retrospective cohort study of consecutive patients who received filters (2002 to 2006) at Johns Hopkins was conducted. Exposures and outcomes were obtained by chart review. Relative risks (RR, 95% confidence interval [CI]) for outcomes in cancer versus noncancer patients were estimated using multistate models.

RESULTS

The cohort included 702 patients-246 with cancer and 456 without cancer. Cancer patients were older, more likely to be white and have filters placed for contraindications to anticoagulation (P<0.01). The most common cancers were lung (11.8%) and colorectal (10.6%). Cancer patients had an increase in venous thromboembolism (RR 1.9 [95% CI, 1.1, 3.2]) due to more deep venous thrombosis/IVC thrombosis (RR 1.7 [95% CI, 1.0, 3.0]). Higher pulmonary embolism rates in cancer were not statistically significant (RR 2.2 [95% CI, 0.8, 5.8]).

CONCLUSIONS

Cancer patients have elevated risks of thrombotic complications compared with noncancer patients; however, these risks are not higher than expected based on historical controls.

Complications of inferior vena cava filters

Inferior vena cava (IVC) filter placement is a relatively low risk alternative for prophylaxis against pulmonary embolism in patients with pelvic or lower extremity deep venous thrombosis who are not suitable for anticoagulation. There is an increasing trend in the number of IVC filter implantation procedures performed every year. There are many device types in the market and in the early 2000s, the introduction of retrievable filters brought an additional subset of complications to consider. Modern filter designs have led to decreased morbidity and mortality, however, a thorough understanding of the limitations and complications of IVC filters is necessary to weight the risks and benefits of placing IVC filters. In this review, the complications associated with IVC filters are divided into procedure related, post-procedure, and retrieval complications. Differences amongst the device types and retrievable filters are described, though this is limited by a significant lack of prospective studies. Additionally, the clinical presentation as well as prevention and treatment strategies are outlined with each complication type.

Permanent versus Retrievable Inferior Vena Cava Filters: Rethinking the "One-Filter-for-All" Approach to Mechanical Thromboembolic Prophylaxis

Inferior vena cava (IVC) filtration for thromboembolic protection is not without risks, and there are important differences among commercially available IVC filters. While retrievable filters are approved for permanent implantation, they may be associated with higher device-related complications in the long term when compared with permanent filters. Prospective patient selection in determining which patients might be better served by permanent or retrievable filter devices is central to resource optimization, in addition to improved clinical follow-up and a concerted effort to retrieve filters when no longer needed. This article highlights the differences between permanent and retrievable devices, describes the interplay between these differences and the clinical indications for IVC filtration, advises against a "one-filter-for-all" approach to mechanical thromboembolic prophylaxis, and discusses strategies for optimizing personalized device selection.

In-Hospital Management and Follow-Up Treatment of Venous Thromboembolism: Focus on New and Emerging Treatments

Venous thromboembolism (VTE), encompassing pulmonary embolism (PE) and deep venous thrombosis (DVT), is a major cause of morbidity and mortality of particular relevance for intensivists and hospitalists. Acute VTE is usually managed with parenteral unfractionated heparin or low-molecular-weight heparin, followed by an oral vitamin K antagonist. Data are lacking for optimal treatment of less common occurrences, such as upper extremity DVT, and for approaches such as thrombolysis for PE associated with early signs of hemodynamic compromise or inferior vena cava filters when anticoagulation is contraindicated. Direct oral anticoagulants (DOACs) including apixaban, dabigatran, edoxaban, and rivaroxaban are now added to the armamentarium of agents available for acute management of VTE and/or reducing the risk of recurrence. This review outlines an algorithmic approach to acute VTE treatment: from aggressive therapies when anticoagulation may be inadequate, to alternative choices when anticoagulation is contraindicated, to anticoagulant options in the majority of patients in whom anticoagulation is appropriate. Evidence-based guidelines and the most recent DOAC clinical trial data are discussed in the context of the standard of care. Situations and treatment approaches for which data are unavailable or insufficient are identified. VTE therapy in care transitions is discussed, as are choices for secondary prevention.

The Role of Potentially Retrievable Inferior Vena Cava Filters in High-Risk Patients Undergoing Joint Arthroplasty

INTRODUCTION

Some patients undergoing total joint arthroplasty are at increased risk for venous thromboembolism (VTE). The aim of the present study was to evaluate the safety and efficacy of prIVCF in preventing PE in patients undergoing joint replacement surgery who are at high-risk for VTE.

MATERIALS AND METHODS

In this prospective, IRB-approved study, prIVCF were placed in consecutive patients who met specific high-risk criteria (history of VTE or hypercoaguable state) prior to total joint arthroplasty. Patients were followed until the IVC filter was removed. Outcomes and complications were recorded per Society of Interventional Radiology guidelines.

RESULTS

One hundred and nine potentially retrievable IVC filters were placed in 105 patients, who all subsequently underwent joint arthroplasty. One hundred eight IVC filters (98.9%) were retrieved successfully in a mean time of 44.1 days (range 13-183 days). There was 1 failed IVC filter retrieval attempt (0.9%) at 46 days post implantation. Two patients (1.9%) presented with recurrent PE and were successfully treated with anticoagulation prior to IVC filter retrieval. There were no fatalities from perioperative PE. In 1 patient (0.9%), a fractured filter leg had embolized during retrieval.

CONCLUSION

Potentially retrievable IVC filters are safe and effective for prophylaxis against PE in patients at high-risk for VTE undergoing joint arthroplasty.

Endovascular treatment of thrombosed inferior vena cava filters: Techniques and short-term outcomes

PURPOSE

To present the techniques for endovascular treatment of thrombosed filter-bearing inferior vena cavae (IVCs), along with short-term clinical and imaging follow-up.

MATERIALS AND METHODS

A total of 45 consecutive patients (17 females and 28 males), aged 19-79 years (mean age of 49 years), who had IVC filter placement complicated by symptomatic acute or chronic iliocaval thrombosis and underwent endovascular therapy were studied. All patients presented with lower extremity swelling and/or pain. One patient also had bilateral lower extremity swelling and chronic gastrointestinal (GI) bleeding which was secondary to chronic systemic to portal venous collaterals. Patients underwent one or more of the following endovascular treatments depending on the chronicity and extent of thrombosis: (a) catheter-directed thrombolysis (CDT) (n = 25), (b) pharmacomechanical thrombolysis (PMT) (n = 15), (c) balloon angioplasty (n = 45), and/or (d) stent placement across the filter (n = 42). In addition, 16 patients underwent groin arteriovenous fistula (AVF) creation (36%) and 3 (7%) had femoral venous thrombectomy to improve flow in the recanalized iliac veins and IVCs.

RESULTS

Anatomical success was achieved in all patients. Follow-up was not available in 10 patients (lost to follow-up, n = 4; expired due to comorbidities, n = 2; lost to follow-up after re-intervention, n = 4). At a mean follow-up time of 13.3 months (range 1-48 months), clinical success was achieved in 27 patients (60%), i.e. in 21 patients without re-intervention and in 6 patients with re-intervention. Clinical success was not achieved despite re-intervention in eight patients. Higher clinical success was noted in patients who did not require repeat interventions (P = 0.03) and the time to re-intervention was significantly shorter in patients who had clinical failure (P = 0.01). AVF creation did not improve the clinical success rate (P = 1). There was no significant difference in clinical success between patients who had acute or subacute thrombosis compared to those who had chronically occluded filter-bearing IVCs (P = 1).

CONCLUSION

This study suggests that endovascular therapy for thrombosed filter-bearing IVCs is safe and technically feasible.

Inferior vena cava filter usage, complications, and retrieval rate in cancer patients

BACKGROUND

Venous thromboembolism contributes significantly to morbidity and mortality in cancer patients. Because cancer patients frequently have contraindications to anticoagulation, inferior vena cava filters are commonly placed. The use, safety, and retrieval of retrievable inferior vena cava filters in cancer patients have not been well studied.

METHODS

A retrospective review of retrievable inferior vena cava filter use at a tertiary referral hospital was conducted between January 1, 2009 and December 31, 2011. Indications for inferior vena cava filter placement, anticoagulation practices, complications, filter retrieval, and patient outcomes were analyzed for patients with and without active cancer and for cancer subtypes, including localized and metastatic cases.

RESULTS

Of 666 patients receiving retrievable inferior vena cava filters during this time period, 247 (37.1%) had active cancer. Of these, 151 (22.7%) had carcinoma, 92 (13.8%) had sarcoma, and 115 (17.3%) had metastatic disease. Overall, follow-up was available for a median of 401.0 (interquartile range: 107.5-786.5) days. Indwelling filter-related complications occurred in 19.8% of patients without cancer and 17.7% with an active cancer (P = .50). Patients with cancer were less likely to have the filter retrieved (28.0% vs 42.0%, P < .001). In multivariable analysis, cancer was not associated with filter-related complications but was associated with a lower rate of filter retrieval.

CONCLUSIONS

In a modern cohort of patients undergoing retrievable inferior vena cava filter placement, active diagnosis of cancer is not associated with a significant increase in filter-related complications, but is associated with a reduced rate of filter retrieval.

Comparison of complication rates associated with permanent and retrievable inferior vena cava filters: a review of the MAUDE database

PURPOSE

To compare the safety of permanent and retrievable inferior vena cava (IVC) filters by reviewing the U.S. Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database.

MATERIALS AND METHODS

The MAUDE database was reviewed from January 1, 2009, to December 31, 2012. Product class search criteria were "filter, intravascular, cardiovascular." Type of device used and specific adverse events (AEs) were recorded.

RESULTS

For the period January 2009-December 2012, 1,606 reported AEs involving 1,057 IVC filters were identified in the MAUDE database . Of reported AEs, 1,394 (86.8%) involved retrievable inferior vena cava filters (rIVCFs), and 212 (13.2%) involved permanent inferior vena cava filters (pIVCFs) (P < .0001). Reported AEs included fracture, migration, limb embolization, tilt, IVC penetration, venous thromboembolism and pulmonary embolism, IVC thrombus, and malfunctions during placement. Each specific AE was reported with significantly higher frequency in rIVCFs compared with pIVCFs. The most common reported complication with rIVCFs was fracture, whereas the most commonly reported complications with pIVCFs were placement malfunctions. For rIVCFs, the most commonly reported AE varied depending on filter brand.

CONCLUSIONS

The MAUDE database reveals that complications occur with significantly higher frequency with rIVCFs compared with pIVCFs. This finding suggests that the self-reported complication rate with rIVCFs is significantly higher than the self-reported complication rate with pIVCFs.

Clinical outcomes and causes of death in Japanese patients with long-term inferior vena cava filter implants and deep vein thrombosis

BACKGROUND AND PURPOSE

We assessed the causes of death and efficacy of permanent inferior vena cava (IVC) filters for preventing new pulmonary embolisms (PE) in Japanese deep vein thrombosis (DVT) patients with or without PE.

METHODS AND SUBJECTS

We studied the clinical outcomes during the follow-up period of 1 day to 9 years (median: 18 months; mean: 28 months) in 66 of 72 consecutive patients (44 with acute PE, 27 with intrapelvic DVT, and 1 with floating femoral vein thrombosis). Fifty of 66 patients received anticoagulant therapy after the filter placement.

RESULTS

Five patients died within 1 month (median 9 days) after the filter placement: three from recurrence of PE, one from cancer, and one from sepsis. Two of the three patients with recurrence of PE had preexisting intracardiac thrombi in the right atrium or main pulmonary artery before filter implantation. Ten patients died from the underlying disease (cancer: 7; brain hemorrhage: 1; amyotrophic lateral sclerosis: 1; pneumonia: 1) over 1 month after the filter placement (median follow-up period: 21 months). No new symptomatic PE recurrence was observed over 1 month after the filter placement. The 61 patients with long-term follow-up had no deterioration of DVT, and all the 31 patients who underwent multi-slice computed tomography showed no PE recurrence or filter thrombus occlusion, fracture, or migration.

CONCLUSIONS

Underlying diseases and preexisting intracardiac thrombi may be the determining factors for the prognosis of DVT patients. Permanent IVC filters with anticoagulant therapy may be effective for preventing death from new PE in Japanese DVT patients.

Effect of delayed inferior vena cava filter retrieval after early initiation of anticoagulation

Retrievable inferior vena cava filters (IVCFs) were designed to provide temporary protection from pulmonary embolism in high-risk situations. However, little is known about their effectiveness, and many remain permanently implanted, leading to potential complications. The aim of this study was to determine patient characteristics, indications for IVCF placement, retrieval rates, complications, and post-IVCF anticoagulation (AC) practices in patients who have received IVCFs. A retrospective review of IVCF use by 3 specialty groups from January 1, 2009, to December 31, 2011, was conducted at a tertiary referral center. Indications for IVCF, procedural success and complications, post-IVCF AC practices, and patient outcomes were assessed. Seven hundred fifty-eight IVCFs were placed. Follow-up was available for 688 patients (90.7%) at a median of 342.0 days (interquartile range 81.5 to 758.0). Indications for IVCF placement included contraindication to AC in the presence of acute venous thromboembolism (n = 287 [41.7%]) and prophylaxis (n = 235 [34.2%]). Insertion-related complications occurred in 28 patients (4.1%). After IVCF placement, adequate AC was initiated in 454 patients (66.0%) <3.0 days (interquartile range 0 to 13.0) after insertion, but the overall retrieval rate was only 252 of 688 (36.6%) within a median of 134.0 days (interquartile range 72.50 to 205.8). Significant IVCF-related complications occurred in 122 patients (17.7%) within 32 days (interquartile range 13.0 to 116.8). The most common complication (72 of 131 [55.0%]) was deep vein thrombosis. In conclusion, in a large, modern cohort of patients receiving retrievable IVCFs for a variety of indications by various specialties, IVCF insertion remains safe. However, many patients have IVCF-related complications, and often, even when IVCFs are retrieved, there is a delay between AC and retrieval. Quality improvement initiatives that facilitate the expeditious retrieval of IVCF are needed.

Thromboprophylaxis in patients with pelvic and acetabular fractures: A short review and recommendations

The management of thromboprophylaxis in patients with pelvic and acetabular fractures remains a highly controversial topic within the trauma community. Despite anticoagulation, venous thromboembolism (VTE) remains the most common cause of surgical morbidity and mortality in this high-risk patient group. Although various thromboprophylactic regimes are employed, evidence relating to the most effective method remains unclear. Controversies surrounding screening, the use of prophylactic inferior vena cava filters (IVCF) and chemothromboprophylaxis in polytraumatised patients, particularly those with pelvic and acetabular fractures, form the basis of considerable debate. With the absence of a well-designed clinical trial and the presence of ongoing controversies within the literature, this review will explore current treatment options available to trauma surgeons and highlight differing scientific opinions, providing an update on the role of screening and current available preventative measures. We cover existing as well as recent advances in chemical thromboprophylactic agents and discuss external mechanical compression devices, the usefulness of serial duplex ultrasonography and the role of extended chemothromboprophylaxis on discharge. The evidence behind prophylactic IVCF is also considered, along with reported complication profiles. We conclude with a proposed protocol for use in major trauma centres, which can form the basis of local policy for the prevention of VTE in trauma patients with pelvic and acetabular fractures.

Clinical review: inferior vena cava filters in the age of patient-centered outcomes

Inferior vena cava filter (IVCF) use continues to increase in the United States (US) despite questionable clinical benefit and increasing concerns over long-term complications. For this review we comprehensively examine the randomized, prospective data on IVC filter efficacy, compare relative rates of IVCF placement in the US and Europe, compare commonly considered guidelines for IVCF indications, and the current data on IVCF complications. Searches of MEDLINE and Cochrane databases were conducted for randomized prospective IVCF studies. Only three randomized prospective studies for IVCFs were identified. Commonly cited IVCF guidelines were reviewed with attention to their evolution over time. No evidence has shown a survival benefit with IVCF use. Despite this, continued rising utilization, especially for primary prophylactic indications, is concerning, given increasing evidence of long-term filter-related complications. This is particularly noted in the US where IVCF placements for 2012 are projected to be 25 times that of an equivalent population in Europe (224,700 versus 9,070). Pending much-needed randomized controlled trials that also evaluate long-term safety, we support the more stringent American College of Chest Physicians (ACCP) guidelines for IVCF placement indications and advocate a close, structured follow-up of retrievable IVCFs to improve filter retrieval rates.

Inferior vena cava filtration in the management of venous thromboembolism: filtering the data

Venous thromboembolism (VTE) is a common cause of morbidity and mortality. This is especially true for hospitalized patients. Pulmonary embolism (PE) is the leading preventable cause of in-hospital mortality. The preferred method of both treatment and prophylaxis for VTE is anticoagulation. However, in a subset of patients, anticoagulation therapy is contraindicated or ineffective, and these patients often receive an inferior vena cava (IVC) filter. The sole purpose of an IVC filter is prevention of clinically significant PE. IVC filter usage has increased every year, most recently due to the availability of retrievable devices and a relaxation of thresholds for placement. Much of this recent growth has occurred in the trauma patient population given the high potential for VTE and frequent contraindication to anticoagulation. Retrievable filters, which strive to offer the benefits of permanent filters without time-sensitive complications, come with a new set of challenges including methods for filter follow-up and retrieval.

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.

Improving retrieval rates for retrievable inferior vena cava filters

The introduction of retrievable inferior vena cava (IVC) filters was an important step in the evolution of deep vein thrombosis/pulmonary embolism management. Their removability makes them preferred to permanent filters in many cases. IVC filter retrieval often occurs at a suboptimal rate, leading to complications associated with long-term placement. Improving retrievability includes solutions for patients being lost to follow-up, filter malpositioning, need arising for permanent IVC filtration, filtration requiring longer than the filter's window of retrievability, and filter compromise by the presence of a large trapped clot. This review explores these strategies for retrieval in detail in hopes of improving IVC filter retrieval rates.

Preliminary Experience With Option Inferior Vena Cava Filter

Objectives:

To evaluate the safety and efficacy of Option inferior vena cava (IVC) filter during placement and short-term follow-up.

Methods:

A total of 165 patients (mean age: 60-years) who received Option IVC filter from June 2009 to July 2011 were included. In all, 42 patients presented with deep vein thrombosis (DVT), 26 with pulmonary embolism (PE), and 17 with both. All outcomes were examined until April 30, 2012.

Results:

The filters were successfully deployed in 161patients. During follow-up (mean, 9.5 ± 0.68months), 10 patients were diagnosed with post-filter PE and 13 patients with DVT. There were no instances of fatal PE. Follow-up abdominal computed tomography was available in 60 patients and demonstrated filter-related problems in 8 patients (2: penetration of filter legs, 5:  asymptomatic nonocclusive thrombus, and 1: caval occlusion). There were no instances of filter migration or fracture. In total, 27 filters were successfully retrieved after a mean of 5.27 ± 0.76 months.

Conclusion:

The Option filter was effective and safe during implantation and short-term follow-up and associated with high technical success at retrieval.

Evaluation and management of chronic pulmonary thromboembolic disease

Pulmonary embolism (PE) is common and the majority of patients survive the acute event. Survivors are at increased risk for adverse outcomes, including persistent thrombi, recurrent embolism, chronic thromboembolic pulmonary hypertension (CTEPH), and death. Anticoagulation protects against recurrence, which has a high mortality rate. The recommended duration of anticoagulation for patients with reversible PE risk factors is 3 months. For patients with idiopathic PE or persistent risk factors, extended duration of anticoagulation is preferred, balanced with an individual patient's risk of hemorrhage, which in itself is a major cause of morbidity and mortality. Among patients with malignancy who develop venous thromboembolism (VTE), low-molecular-weight heparin is preferred over oral vitamin K antagonists in the first 6 months. Thereafter, anticoagulation should be continued indefinitely with either low-molecular-weight heparin or oral vitamin K antagonists. Inferior vena cava filters are not routinely recommended and should only be used in patients who have a contraindication to anticoagulation. Patients who have had VTE and with persistent or recurrent dyspnea should be evaluated for recurrence of VTE or development of CTEPH. Patients with recurrent VTE should be anticoagulated indefinitely. Routine screening for CTEPH in asymptomatic patients is not recommended. Echocardiography often provides the first indication of the presence of pulmonary hypertension. Once presence of CTEPH is established by right-sided heart catheterization and perfusion imaging (ie, ventilation/perfusion scintigraphy, computed tomography angiography, or pulmonary angiography), patients should be referred early to a center with expertise, as it is potentially surgically curable by pulmonary endarterectomy. Those who are deemed inoperable after being evaluated may gain symptomatic benefit from drugs approved for idiopathic pulmonary arterial hypertension. Lung transplantation may also be an option for patients who are not candidates for pulmonary endarterectomy.