Guidelines for the Use of Retrievable and Convertible Vena Cava Filters: Report from the Society of Interventional Radiology Multidisciplinary Consensus Conference

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.

Practice patterns of retrievable inferior vena cava filters and predictors of filter retrieval in patients with pulmonary embolism

Retrievable inferior vena cava (IVC) filters are increasingly used in patients with venous thromboembolism (VTE) who have contraindications to anticoagulant therapy. However, previous studies have shown that many retrievable filters are left permanently in patients. This study aimed to identify the common indications for IVC filter insertion, the filter retrieval rate, and the predictive factors for filter retrieval attempts. To this end, a retrospective cohort study was performed at a tertiary care center in South Korea between January 2010 and May 2016. Electronic medical charts were reviewed for patients with pulmonary embolism (PE) who underwent IVC filter insertion. A total of 439 cases were reviewed. The most common indication for filter insertion was a preoperative/procedural aim, followed by extensive iliofemoral deep vein thrombosis (DVT). Retrieval of the IVC filter was attempted in 44.9% of patients. The retrieval success rate was 93.9%. History of cerebral hemorrhage, malignancy, and admission to a nonsurgical department were the significant predictive factors of a lower retrieval attempt rate in multivariate analysis. With the increased use of IVC filters, more issues should be addressed before placing a filter and physicians should attempt to improve the filter retrieval rate.

Vena Cava Filter Retrieval Rates and Factors Associated With Retrieval in a Large US Cohort

Background

Retrieval of vena cava filters (VCFs) is important for safety as complications increase with longer dwell times. This study assessed VCF retrieval rates and factors associated with retrieval in a national cohort.

Methods and Results

VCFs were identified by procedural codes from an administrative claims database. Patients were identified who had a VCF placement during a hospitalization from a national commercial administrative claims database. Indications for VCF placement were identified as pulmonary embolism with or without deep vein thrombosis, deep vein thrombosis only, or prophylactic. Patient demographic and clinical characteristics were included in proportional hazard regression models to find associations with early (90‐day) and 1‐year VCF retrieval. Initiation of anticoagulation and the correlation between time‐to‐retrieval and time‐to‐initiation of anticoagulation were observed. Of 54 766 patients receiving a VCF, 36.9% had pulmonary embolism, 43.9% had deep vein thrombosis only, and 19.2% had no apparent venous thromboembolism present. Over the 1 year of follow‐up, the cumulative incidence of VCF retrieval was 18.4%. Retrieval increased over time from a low of 14.0% in 2010 up to ≈24% in 2014. In adjusted time‐to‐event models, increasing age, differing regions, and some comorbidities were associated with poorer retrieval rates. Initiation of anticoagulation was poorly correlated with retrieval, with anticoagulation preceding retrieval by a median of 51 days while those without retrieval had a median of 278 days of exposure to anticoagulation.

Conclusions

VCF retrieval increased over the study period but remained suboptimal and was weakly correlated with anticoagulation initiation.

Retrieval characteristics of the Bard Denali and Argon Option inferior vena cava filters

OBJECTIVE

The purpose of this study was to compare the retrieval characteristics of the Option Elite (Argon Medical, Plano, Tex) and Denali (Bard, Tempe, Ariz) retrievable inferior vena cava filters (IVCFs), two filters that share a similar conical design.

METHODS

A single-center, retrospective study reviewed all Option and Denali IVCF removals during a 36-month period. Attempted retrievals were classified as advanced if the routine "snare and sheath" technique was initially unsuccessful despite multiple attempts or an alternative endovascular maneuver or access site was used. Patient and filter characteristics were documented.

RESULTS

In our study, 63 Option and 45 Denali IVCFs were retrieved, with an average dwell time of 128.73 and 99.3 days, respectively. Significantly higher median fluoroscopy times were experienced in retrieving the Option filter compared with the Denali filter (12.18 vs 6.85 minutes; P = .046). Use of adjunctive techniques was also higher in comparing the Option filter with the Denali filter (19.0% vs 8.7%; P = .079). No significant difference was noted between these groups in regard to gender, age, or history of malignant disease.

CONCLUSIONS

Option IVCF retrieval procedures required significantly longer retrieval fluoroscopy time compared with Denali IVCFs. Although procedure time was not analyzed in this study, as a surrogate, the increased fluoroscopy time may also have an impact on procedural direct costs and throughput.

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.

The high-risk polytrauma patient and inferior vena cava filter use

OBJECTIVES

The aim of this study was to assess the impact on practice of vena cava filter insertion guidelines (Eastern Association for the Surgery of Trauma: practice management guidelines).

DESIGN

The study was performed at a level 1 trauma centre with data from the 'Trauma Audit and Research Network' cross-referenced to hospital data.

RESULTS

A total of 1138 specific 'high-risk' major trauma patients were identified over a 6-year period. The mean age was 46 years (18-102) and the male to female ratio was 3.3:1. The average Injury Severity Score was 23.6 (4-75). The overall DVT rate was 2.6% and the PE rate was 1.8%. A retrievable IVC filter was inserted in 42 cases (3.8%). The filter retrieval rate was 23.8% at a mean of 68.5days (4-107). Only one complication was reported of a breakthrough PE despite filter. Applying the EAST guidelines to this cohort would have suggested filter insertion in 279 (24.6%) cases. The kappa concordance value between observed practice and the 'EAST filter group' was 0.103 (poor). The PE rate in the 'EAST filter group' was 2.2% vs 1.6% in the 'no filter group' (p=0.601, no statistical difference) and the observed odds ratio was 0.814 (95% CI 0.413, 1.602).

CONCLUSION

The EAST guidelines are useful but may be overestimating the need for filter insertion.

A case of hepatic, renal and duodenal penetration by a Celect inferior vena caval filter

Inferior vena caval (IVC) filters are used as a mechanical option for the treatment of venous thromboembolism (VTE) when standard anticoagulation therapy is either contraindicated or VTE recurs despite adequate anticoagulation. Filters are not without risk, however. Reported complications include filter migration and fracture of filter components, leading to IVC rupture and penetration into pericaval tissues (notably kidney, heart, pericardium, thoracic cavity, liver, bowel and aorta). Here we describe an extreme case of multiple organ penetration by a standard Celect caval filter.

Cost-benefit analysis of establishing an inferior vena cava filter clinic

PURPOSE

Adverse events associated with retrievable inferior vena cava filters (IVCFs) have generated an increased interest in improving IVCF retrieval rates to improve patient safety and quality care. This study aims to demonstrate the cost-benefit of implementing an IVCF clinic to improve patient care in an institution in the United States.

METHODS

An IVCF clinic was established at a single institution in September 2012 and for ten months referring physicians were contacted to facilitate retrieval when appropriate. Additionally, a retrospective review was conducted on filter placements over the eight preclinic months. Cost-benefit analysis was conducted by creating a model, which incorporated the average cost and reimbursement for permanent and retrievable IVCFs.

RESULTS

A total of 190 IVCFs (152 retrievable IVCFs and 38 permanent IVCFs) were implanted during the IVCF clinic period. Twenty-nine percent of the retrievable IVCFs were successfully retrieved compared to 10 of 119 retrievable IVCFs placed during the preclinic period (8.4%). Cost-benefit analysis, using the average of the institution's six most common reimbursement schedules, demonstrated an average net financial loss per permanent or retrievable IVCF not removed. However, a net financial gain was realized for each retrievable IVCF removed. The additional hospital cost to maintain the IVCF clinic was offset by removing an additional 3.1 IVCFs per year.

CONCLUSION

An IVCF clinic significantly increases retrieval rates, promotes patient safety, and is economically feasible. Given the adverse event profile of retrievable IVCFs, strategic efforts such as these ultimately can improve quality care for patients with in-dwelling IVCFs.

Novel and Advanced Techniques for Complex IVC Filter Retrieval

OPINION STATEMENT

Inferior vena cava (IVC) filter placement is indicated for the treatment of venous thromboembolism (VTE) in patients with a contraindication to or a failure of anticoagulation. With the advent of retrievable IVC filters and their ease of placement, an increasing number of such filters are being inserted for prophylaxis in patients at high risk for VTE. Available data show that only a small number of these filters are retrieved within the recommended period, if at all, prompting the FDA to issue a statement on the need for their timely removal. With prolonged dwell times, advanced techniques may be needed for filter retrieval in up to 60% of the cases. In this article, we review standard and advanced IVC filter retrieval techniques including single-access, dual-access, and dissection techniques. Complicated filter retrievals carry a non-negligible risk for complications such as filter fragmentation and resultant embolization of filter components, venous pseudoaneurysms or stenoses, and breach of the integrity of the caval wall. Careful pre-retrieval assessment of IVC filter position, any significant degree of filter tilting or of hook, and/or strut epithelialization and caval wall penetration by filter components should be considered using dedicated cross-sectional imaging for procedural planning. In complex cases, the risk for retrieval complications should be carefully weighed against the risks of leaving the filter permanently indwelling. The decision to remove an embedded IVC filter using advanced techniques should be individualized to each patient and made with caution, based on the patient's age and existing comorbidities.

IVC filters-Trends in placement and indications, a study of 2 populations

Inferior vena cava filter (IVCF) placement appears to be expanding over time despite absence of clear directing evidence.Two populations were studied. The first population included patients who received an IVCF between January 2005 and August 2013 at our community hospital center. Demographic information, indications for placement, and retrieval rate was recorded among other variables. The second population comprised of patients receiving an IVCF from 2005 to 2012 according to the Nationwide Inpatient Sample (NIS) using ICD-9CM coding. Patients were divided into 2 groups based on the year of admission for comparison, that is, first group from 2005 to 2008 and the second from 2009 to 2012. In addition, we analyzed annual trends in filter placement, acute venothromboembolic events (VTE) and several underlying comorbidities within this population.At our center, 802 IVCFs were placed (55.2% retrievable); 34% for absolute, 61% for relative, and 5% for prophylactic indications. Major bleeding (27.5%), minor self-limited bleeding (13.7%), and fall history (11.2%) were the commonest indications. Periprocedural complication rate was 0.7%, and filter retrieval rate was 7%. The NIS population (811,487 filters) saw a decline in IVCF placement after year 2009, following an initial uptrend (Ptrend < 0.01). IVCF use among patients with neither acute VTE nor bleeding among prior VTE saw a 3-fold absolute reduction from 2005 to 2012 (33,075-11,655; Ptrend < 0.01). Patients from 2009 to 2012 were more likely to be male and had higher rates of acute VTE, thrombolytic use, cancer, bleeding, hypotension, acute cardiorespiratory failure, shock, prior falls, blood product transfusion, hospital mortality including higher Charlson comorbidity scores. The patients were younger, had shorter length of stay, and were less likely to be associated with strokes including hemorrhagic or require ventilator support. Prior falls (adjusted odds ratio-aOR 2.8), thrombolytic use (aOR 1.76), and shock (aOR 1.45) were most predictive of IVCF placement between 2009 and 2012 on regression analysis.Recent trends suggest that a higher proportion of patients receive temporary IVCF, for predominantly relative indications. Nationally, the number of filters being placed is decreasing, especially among those who did not experience acute VTE or bleeding events. Prior falls, thrombolytic therapy, and shock were most predictive of IVCF placement in latter half of the study period.

Hospital Variation and Patient Characteristics Associated With Vena Cava Filter Utilization

INTRODUCTION

There is a wide variation in the use of vena cava filter (VCF).

OBJECTIVE

This study assessed the hospital and patient characteristics associated with VCF use in deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

Inpatient discharge data from all acute care hospitals with DVT/PE during 2008-2014 in Kentucky were used. Hierarchical logistic regression models were used to evaluate the relationships of study variables with VCF use.

RESULTS

During the study period, 81,922 discharges for DVT/PE were observed and 10.5% of these received a VCF. This included 12,083 cases of PE+DVT, 18,571 cases of PE only, and 51,268 cases of DVT only. VCF use among these groups was 22.7%, 6.0%, and 7.8%, respectively. In adjusted analyses, VCF use was associated with increasing age, indicating that those over age 65 were twice as likely to receive a filter compared with the reference (21-25 y old) group. Significant comorbidities associated with VCF use included cancer, liver disease, cerebrovascular disease, atrial fibrillation, anemia, and concurrent bleeding. Lower extremity, proximal DVTs, and patients receiving thrombolytic therapy or embolectomy, those having surgery, and those who were unstable or had trauma, were also more likely to receive a filter. Among cancer types, brain and metastatic tumors were significantly associated with VCF use. Between-hospital variation after controlling for all covariates was 7.1%.

CONCLUSIONS

There was high variation in the use of VCFs. Several high-risk subgroups were more likely to use VCFs including older adults and those with cancer and concurrent bleeding.

Inferior vena cava filters

Use of inferior vena cava (IVC) filters has increased dramatically in recent decades, despite a lack of evidence that their use has impacted venous thromboembolism (VTE)-related mortality. This increased use appears to be primarily driven by the insertion of retrievable filters for prophylactic indications. A growing body of evidence, however, suggests that IVC filters are frequently associated with clinically important adverse events, prompting a closer look at their role. We sought to narratively review the current evidence on the efficacy and safety of IVC filter placements. Inferior vena cava filters remain the only treatment option for patients with an acute (within 2-4 weeks) proximal deep vein thrombosis (DVT) or pulmonary embolism and an absolute contraindication to anticoagulation. In such patients, anticoagulation should be resumed and IVC filters removed as soon as the contraindication has passed. For all other indications, there is insufficient evidence to support the use of IVC filters and high-quality trials are required. In patients where an IVC filter remains, regular follow-up to reassess removal and screen for filter-related complications should occur.

Inferior vena cava filter retrievals, standard and novel techniques

The placement of an inferior vena cava (IVC) filter is a well-established management strategy for patients with venous thromboembolism (VTE) disease in whom anticoagulant therapy is either contraindicated or has failed. IVC filters may also be placed for VTE prophylaxis in certain circumstances. There has been a tremendous growth in placement of retrievable IVC filters in the past decade yet the majority of the devices are not removed. Unretrieved IVC filters have several well-known complications that increase in frequency as the filter dwell time increases. These complications include caval wall penetration, filter fracture or migration, caval thrombosis and an increased risk for lower extremity deep vein thrombosis (DVT). Difficulty is sometimes encountered when attempting to retrieve indwelling filters, mainly because of either abnormal filter positioning or endothelization of filter components that are in contact with the IVC wall, thereby causing the filter to become embedded. The length of time that a filter remains indwelling also impacts the retrieval rate, as increased dwell times are associated with more difficult retrievals. Several techniques for difficult retrievals have been described in the medical literature. These techniques range from modifications of standard retrieval techniques to much more complex interventions. Complications related to complex retrievals are more common than those associated with standard retrieval techniques. The risks of complex filter retrievals should be compared with those of life-long anticoagulation associated with an unretrieved filter, and should be individualized. This article summarizes current techniques for IVC filter retrieval from a clinical point of view, with an emphasis on advanced retrieval techniques.

Effect of Chemical Thromboprophylaxis on the Rate of Venous Thromboembolism After Treatment of Foot and Ankle Fractures

BACKGROUND

Venous thromboembolism (VTE) is a well-documented complication in patients with lower limb fractures, but management guidelines for its prevention in isolated foot and ankle fracture patients are conflicting. The aim of this study was to conduct a multicenter, prospective cohort study to define the prevalence of VTE in patients with isolated foot and ankle fractures and determine whether routine prophylaxis is necessary in these patients.

METHODS

In a double-blind, placebo-controlled study, consecutive patients in 3 hospitals who met our criteria were enrolled. After randomization, patients received either thromboprophylaxis with low-molecular-weight heparin units (LMWH group) or placebo (placebo group) for a period of 2 weeks. All patients underwent routine ultrasonography 1 day preoperatively, 1 week postoperatively, and 1 month postoperatively. Demographic parameters were then collected and compared.

RESULTS

Of the 814 patients who met our criteria, 19 patients (2.3%, 95% confidence interval [CI], 0%-31.9%) were found to have objectively confirmed VTE, but none of the patients were symptomatic. Of the 411 patients in the LMWH group, 2 developed VTEs preoperatively and 4 postoperatively; of the 403 patients in the placebo group, 5 developed VTEs preoperatively and 8 postoperatively. The overall incidence of asymptomatic postoperative deep vein thrombosis (DVT) was 0.98% (95% CI 0%-20.3%) in the LMWH group and 2.01% (95% CI 0%-29.5%) in the placebo group without significant difference. Advanced age (odds ratio [OR] 1.050, 95% CI 1.014-1.088, P = .007) and high body mass index (OR 1.201, 95% CI 1.034-1.395, P = .016) were identified as risk factors in predicting occurrence of DVT. No fatal pulmonary emboli or major bleeding complication occurred in either group.

CONCLUSION

Routine anticoagulant prophylaxis was not found to be necessary for patients with foot and ankle fractures, although further investigation with a properly powered study design is required to definitively determine which foot and ankle patients are best served by anticoagulation and which ones are not.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Indications, complications and outcomes of elderly patients undergoing retrievable inferior vena cava filter placement

AIM

The utilization of inferior vena cava filter placement for pulmonary embolism prevention in elderly patients has not been well characterized. The present study aimed to review indications, complications and follow-up data of elderly patients undergoing inferior vena cava filter placement.

METHODS

A retrospective review was carried out of consecutive admitted patients who underwent inferior vena cava filter insertion at a large university hospital with a level I trauma center.

RESULTS

Overall, 455 retrievable filters were inserted between 2009 and 2014. A total of 133 patients (29.2%) were aged ≥70 years. Elderly patients were less likely to have their filter retrieved compared with non-elderly patients (5.3% vs 21.4%, P < 0.001). Filter-related complications occurred in 13% of non-elderly patients and 14.3% of elderly patients (P = 0.72), most of them occurring in the first 3 months after filter placement. Survival among elderly patients with no evidence of active malignancy was similar to the non-elderly patients with a 1-year survival rate of 76.3% versus 82% in non-elderly patients (P = 0.22), and a 2-year survival rate of 73.1% versus 78.6% in non-elderly patients (P = 0.27). Although decreased, survival rates among elderly patients with active cancer were still substantial, with a 1-year survival rate of 45% and 2-year survival rate of 40%.

CONCLUSIONS

Elderly patients had significantly lower rates of filter retrieval with similar complication rate. Survival rates among elderly patients were substantial, and in elderly patients with no active cancer were even comparable with non-elderly patients. When feasible, filter retrieval should be attempted in all elderly patients in order to prevent filter-related complications. Geriatr Gerontol Int 2017; 17: 1508-1514.

Predictors of Interventional Treatment Use for Venous Thromboembolism in Cancer Patients

Venous thromboembolic disease is a major cause of morbidity in cancer patients. The Perspective database was used to identify patients with solid tumors and a diagnosis of VTE from 2006 to 2012. We examined use of IVC filters, thrombolysis, and thrombectomy. Among 32,545 patients, 23.1% received an IVC filter, 1.9% thrombolytic therapy, and 0.4% underwent thrombectomy. Use of IVC filters decreased between 2006 and 2012 (23.4% to 21.2%, p = 0.012). Older patients, uninsured patients, Hispanics, and those with more comorbidities were more likely to undergo filter placement while patients at rural hospitals were less likely to receive an IVC filter (p < 0.05 for all).

Retrievable IVC filters - Friend or foe

Venous thromboembolism is a common condition with widely varied outcomes. Pulmonary embolism is associated with a case-fatality rate of up to 8%, increasing up to 18-fold in massive PE. Pharmacological treatment of VTE with anticoagulant medication (AC) is the first line therapy of choice. Retrievable inferior vena cava filters (IVCF) are indicated as a short-term replacement for AC in certain circumstances. Most of the evidence concerning IVCF pertains to permanent filters and older filter models. Limited evidence for retrievable IVCF results in poor consensus regarding indications, follow-up and retrieval. Complications increase with dwell-time and retrieval success rates decline. Professional bodies advocate strict guideline adherence and robust strategies for filter monitoring to maximise retrieval rate.

Incidence and Outcomes of Inferior Vena Cava Filter Thrombus during Catheter-directed Thrombolysis for Proximal Deep Venous Thrombosis

BACKGROUND

The aim of the study was to retrospectively evaluate the incidence and outcomes of inferior vena cava (IVC) filter thrombus during catheter-directed thrombolysis (CDT) for acute proximal deep venous thrombosis (DVT).

METHODS

From October 2006 to June 2015, patients diagnosed with acute proximal DVT and received CDT after a retrievable IVC filter was placed were included. The incidence, treatment, and outcomes of IVC filter thrombus during CDT were recorded and analyzed.

RESULTS

A total of 189 patients (91 women, 98 men; mean age, 57.6 ± 9.8 years; range, 24-85 years) were included in this study. Among the 189 cases, the DVTs involved popliteal iliofemoral veins in 54 patients, iliofemoral veins in 113 patients, and iliac veins in 22 patients, of which 18 patients had thrombus extended into the IVC. Of the 189 patients, a total of 8 (4.2%, 8 of 189) patients were identified with IVC filter thrombus during CDT. The IVC filter thrombus was detected on a median of 2 days (range, 2-4 days) of CDT therapy, including small-size (n = 6) and large-size (n = 2) filter thrombus. Of the 8 patients, CDTs were performed with a mean 7.6 ± 1.1 days (range, 6-11 days) after the presence of symptoms for the treatment of proximal DVT, and all the IVC filter thrombi were lysed during CDT for the proximal DVT. All the IVC filters were removed successfully with a mean of 12.8 ± 0.93 days from placement. There were no procedure- or thrombolysis-related major complications, and no symptomatic pulmonary embolism breakthrough was seen in any of the patients after the filter placement.

CONCLUSIONS

IVC filter thrombus during CDT for the acute proximal DVT is uncommon, and all of them did not need any additional treatment.

Effectiveness of Inferior Vena Cava Filters without Anticoagulation Therapy for Prophylaxis of Recurrent Pulmonary Embolism

OBJECTIVE

The optimal treatment of deep vein thrombosis (DVT) is anticoagulation therapy. Inferior vena cava filter (IVC) placement is another option for the prevention of pulmonary embolism (PE) in patients with deep vein thrombosis. This is used mostly in patients with a contraindication to anticoagulant therapy. The purpose of the present study was to compare the two options.

METHODS

A retrospective cohort study of two groups of patients with DVT: patients who received an IVC filter and did not receive anticoagulation due to contraindications; and patients with DVT and similar burden of comorbidity treated with anticoagulation without IVC insertion. To adjust for a potential misbalance in baseline characteristics between the two groups, we performed matching for age, gender, and Charlson's index, which is used to compute the burden of comorbid conditions. The primary outcome was an occurrence of a PE.

RESULTS

We studied 1,742 patients hospitalized with the diagnosis of DVT in our hospital;93 patients from this population received IVC filters. Charlson's score index was significantly higher in the IVC filter group compared with the anticoagulation group. After matching of the groups of patients according to Charlson's score index there were no significant differences in primary outcomes.

CONCLUSION

Inferior vena cava filter without anticoagulation may be an alternative option for prevention of PE in patients with contraindications to anticoagulant therapy.

Optional Vena Cava Filters: What, Why, and When

Optional vena cava filters can used to provide either short-term or permanent protection from pulmonary embolism. These devices have recently become available for clinical use in the United States. However, there remains a paucity of data about these devices and their outcomes. This article reviews current and future devices, the rationale behind non-permanent caval filtration, and the generally accepted guidelines for their clinical application.

Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters

Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

A Dedicated Inferior Vena Cava Filter Service Line: How to Optimize Your Practice

Despite the increased placement of retrievable inferior vena cava filters (rIVCFs), efforts to remove these devices are not commensurate. The majority of rIVCFs are left in place beyond their indicated usage, and often are retained permanently. With a growing understanding of the clinical issues associated with these devices, the United States Food and Drug Administration (FDA) has prompted clinicians to remove rIVCF when they are no longer indicated. However, major obstacles exist to filter retrieval, chief among them being poor clinical follow-up. The establishment of a dedicated IVC filter service line, or clinic, has been shown to improve filter retrieval rates. Usage of particular devices, specifically permanent versus retrievable filters, is enhanced by prospective physician consultation. In this article, the rationale behind a dedicated IVC filter service line is presented as well as described the structure and activities of the authors' IVC filter clinic; supporting data will also be provided when appropriate.

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.

The Role of Inferior Vena Cava Filters in Cancer Patients

Cancer induces a hypercoagulable state and renders patients susceptible to venous thromboembolism. While anticoagulation remains the mainstay of treatment, many of these patients require placement of an inferior vena cava (IVC) filter, often due to a contraindication to or failure of anticoagulation. In this article, the available data on IVC filter usage in cancer patients will be reviewed.

Inferior Vena Cava Filter-Related Thrombus/Deep Vein Thrombosis: Data and Management

Recurrent deep venous thrombosis and inferior vena cava (IVC) thrombosis are well-described complications following IVC filter placement. IVC thrombosis ranges in severity of clinical presentation, but can lead to significant morbidity and mortality with incidence rates depending on patient population and type of filter used. Endovascular therapies such as catheter-directed thrombolysis, mechanical thrombectomy, balloon venoplasty, and stenting are safe and effective in restoration of venous patency.

A Critical Review of Available Retrievable Inferior Vena Cava Filters and Future Directions

Inferior vena cava filters have been placed in patients for decades for protection against pulmonary embolism. The widespread use of filters has dramatically increased owing at least in part to the approval of retrievable vena cava filters. Retrievable filters have the potential to protect against pulmonary embolism and then be retrieved once no longer needed to avoid potential long-term complications. There are several retrievable vena cava filters available for use. This article discusses the different filter designs as well as the published data on these available filters. When selecting a filter for use, it is important to consider the potential short-term complications and the filters' window for retrieval. Understanding potential long-term complications is also critical, as these devices are approved for permanent placement and many filters are not retrieved. Finally, this article will address research into new designs that may be the future of vena cava filtration.

Inferior Vena Cava Filters: Guidelines, Best Practice, and Expanding Indications

Vena caval interruption, currently accomplished by percutaneous image-guided insertion of an inferior vena cava (IVC) filter, is an important therapeutic option in the management of selected patients with venous thromboembolism. The availability of optional (or retrievable) filters, in particular, has altered the practice patterns for IVC filters, with a shift to these devices and expansion of indications for filter placement. As new devices have become available and clinicians have become more familiar and comfortable with IVC filters, the indications for filter placement have continued to evolve and expand. This article reviews current guidelines and expanding indications for IVC filter placement.

Observations on failed retrieval of optional inferior vena cava filters

PURPOSE

To evaluate causes of failed optional inferior vena cava filter (IVCF) retrievals.

METHODS

Single-center retrospective study.

RESULTS

IVCF retrievals were attempted in 26/211 (12%) patients at a mean 42.9 days. There were 9 failures (all OptEase) due to: inability to snare the hook (n=5), noncollapsible IVCF (n=3), and unusual procedural pain (n=1). Median duration of retrieved IVCFs was 31 days compared to 53 days for failures (P<.05). IVCFs aligned with the IVC's cephalocaudal axis were retrieved in 13/16 cases, while misaligned IVCFs were retrieved 4/10 cases (P<.05).

CONCLUSION

Filter duration and misalignment were significantly associated with retrieval failures.

Inferior vena cava filters: current best practices

Venous thromboembolism (VTE) is a common cause of inpatient and outpatient morbidity and mortality. While anticoagulant therapy is considered the primary means of prevention and treatment of VTE, inferior vena cava filters (IVCFs) are often used as an alternative or adjunct to anticoagulation. With the advent of retrievable filters indications have liberalized, to include placement for primary prophylaxis in high-risk patients. However, this practice is based on limited evidence supporting their efficacy in preventing clinically relevant outcomes. Since indiscriminate use of IVCFs can be associated with net patient harm and increased health care costs, knowledge of the literature surrounding IVCF utilization is critical for providers to adopt best practices. In this review, we will provide an overview of the literature as it relates to specific clinical questions that arise when considering IVCF utilization in the prevention and treatment of VTE. Practice-based recommendations will be reviewed to provide the clinician with guidance on challenging clinical scenarios.

Catheter-directed thrombolysis for extensive iliofemoral deep vein thrombosis: review of literature and ongoing trials

In patients with extensive lower limb deep vein thrombosis (DVT) that, typically, extends into the iliofemoral veins, catheter-directed thrombolysis (CDT) can achieve faster and more complete thrombus lysis as compared with systemic thrombolysis, while providing an acceptable safety profile through administration of lower doses of thrombolytic agents. Through a reduction in thrombus burden, CDT has the potential to mitigate the risk for post-thrombotic syndrome by restoring venous patency and preserving venous valve function. The efficacy of CDT may be improved by adjunctive approaches that include percutaneous mechanical thrombectomy, angioplasty with or without stenting, and ultrasound-assisted CDT. CDT may also have a specific therapeutic role in the management of iliofemoral DVT involving patients who are pregnant or with May-Thurner syndrome. This article summarizes the literature in this area and discusses recently completed and ongoing randomized trials on the use of CDT in patients with extensive lower limb DVT.

Inferior vena cava (IVC) filters in children: A 10-year single center experience

BACKGROUND

Venous thromboembolism (VTE) is an increasingly recognized problem among children and adolescents. Although inferior vena cava (IVC) filter placement for pulmonary embolism prevention is well reported in adults, data regarding safety and efficacy in the pediatric age group are lacking.

PROCEDURE

At a large university hospital with a level I trauma center, medical records of children and adolescents who underwent IVC filter insertion were reviewed. Appropriateness of referral for retrieval was assessed in each case.

RESULTS

Fifty-nine children and adolescents (mean age 16 years) successfully underwent IVC filter insertion. All filters placed were retrievable. In 47 patients (79.7%), prophylactic filters were placed in the absence of acute VTE in the setting of trauma. In eight patients (13.5%), filters were placed due to contraindication to anticoagulation therapy with concomitant lower extremity deep vein thrombosis or pulmonary embolism. Filters were successfully retrieved in only 12 patients (20.3%), although an attempt at removal was appropriate and feasible in over 90% of cases. Mean duration of follow-up was 2.1 (range 0.4-7.3) years. A significantly higher retrieval rate was found in patients followed at our thrombosis clinic (P < 0.01). Ten patients (17%) experienced at least one filter-related complication.

CONCLUSIONS

Although in most cases, IVC filters were placed for prophylactic indications, the evidence to support their role in this setting is limited. Their low retrieval rate and high filter-related complication rate question their extensive utilization in children. Dedicated follow-up is necessary to detect complications and to ensure that an attempt at retrieval is made when feasible.

Mechanical behavior and blood compatibility of copper-containing films as potential biomaterials

Surface modification is one approach to enhance the biocompatibility of implanted cardiovascular devices. In this work, a copper-containing film used to blood contacted biomaterials was prepared by vacuum arc deposition. The phase composition of the films was investigated via X-ray diffraction, and the adherence strength of the films was evaluated with conventional deformation tests. Blood compatibility of the films was characterized by hemolysis ratio, clotting time and platelet adhesion etc. The surface of inferior vena cava filters were smooth and uniform, no cracks or delaminations were observed on the deformed surface. These results indicate that the mechanical behavior of the films is suitable for withstanding deformation stresses as operation in clinic. Good blood compatibility of the copper-containing films was identified through experiment in vitro, the activated partial thromboplastin times (APTTs) of Cu/Ti films were similar to that of the uncoated substrate, and Cu/Ti films were also found to inhibit platelet adhesion comparing to the nitinol substrate. However, with increasing ratio of Cu/Ti, the hemolysis ratio increased, resulting in platelet damage. These results indicate that the copper-containing film has potential application on blood contacted devices.