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

Inferior Vena Cava Filter Placed in Neurologic Intensive Care Unit: Effectiveness, Retrieval Rate, and Mortality

PURPOSE

Patients in neurologic intensive care unit (NICU) often undergo inferior vena cava filter (IVCF) placement for venous thrombotic events. This study aims to determine the effectiveness of IVCF, filter retrieval, and mortality among patients that received IVCF in NICU.

MATERIALS AND METHODS

In this single institutional, noncomparative, retrospective study, all patients who were admitted to NICU and underwent IVCF placement from April 2015 to December 2020 were reviewed. IVCF was successfully deployed in all 175 patients [100%; median age 68 years, female 84/175 (48.0%)]. The 3 most common causes for NICU admission were intracranial hemorrhage (66/175, 37.7%), ischemic stroke (62/175, 35.4%), and traumatic brain injury (16/175, 9.1%). Deep vein thrombosis and pulmonary embolism (PE) were confirmed in 155 (88.6%) and 35 (20.0%) patients at the time of filter placement, respectively. Primary outcomes of interest were postfilter placement PE, filter retrieval, and inhospital mortality. Baseline characteristics were analyzed using t-tests and chi-squared test for continuous and noncontinuous variables, respectively. Factors associated with primary outcomes were analyzed with a logistic regression model.

RESULTS

Post-IVCF PE occurred in 3 patients (1.7%) with a median follow-up of 3 months. Excluding 26 inhospital deaths (14.9%, none was related to PE), filters were retrieved in 31 discharged patients (20.8%) with a median filter dwelling time of 9 months. Advanced filter retrieval required a higher fluoroscopy time (median 3.3 minutes vs 8.3 minutes, p = 0.016) and contrast volume use (median 35.0 ml vs 57.5 ml, p = 0.0028) than standard technique. No procedure-related complication occurred during filter placement and retrieval. Sequential Organ Failure Assessment (SOFA, p = 0.012) and Simplified Acute Physiology Scores (SAPS, p = 0.016) were independently associated with inhospital mortality. Modified Rankin Score (mRS) at discharge was an independent predictor for filter retrieval (p < 0.001).

CONCLUSION

Despite safety and effectiveness, IVCF retrieval rate for NICU patients was low, particularly those with worse mRS at time of hospital discharge. Worse SOFA and SAPS scores were associated with inhospital mortality.Clinical ImpactInferior vena cava filter (IVCF) is effective preventing post-filter pulmonary embolism (PE) in neurologic intensive care unit (NICU) patients, with only 1.7% experiencing PE post-placement, underscoring its role in managing venous thrombotic events in this high-risk population; however, the low retrieval rate of IVCFs, particularly in patients with poorer functional outcomes (worse mRS at discharge), and the association of higher SOFA and SAPS scores with increased inhospital mortality, emphasize the need for improved strategies to optimize filter retrieval and patient selection in critically ill neurologic patients.

Design and performance analysis of a new inferior vena cava filter

This study proposes a novel inferior vena cava filter (IVCF) design, "Lotus," aiming to enhance release stability and endothelialization. A catheter-filter-vessel model was established for IVCF property analysis, validated by comparing numerical simulations and in vitro tests. Lotus's mechanical properties were analyzed, and optimization suggestions are provided. Compared to existing clinical filters, Lotus demonstrates improved release stability and thrombus capture ability. This work suggests Lotus as a potential technical reference for improved IVCF treatment.

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.

Esophageal Stents for the Management of Benign Esophageal Strictures in Children and Adolescents: A Systematic Review of Observational Studies

Little is known about the efficacy and safety of esophageal stents for the management of esophageal strictures in children and adolescents. A systematic review was performed to assess the efficacy and safety of esophageal stents for the management of benign esophageal strictures in children and adolescents. Observational studies related to the examination of esophageal stents in pediatrics were extracted using the original databases by December 2021. We found 18 retrospective and prospective studies with a total of 340 children and adolescents. Overall, our findings show that different therapeutic modalities based on esophageal stents were offered to children and adolescents for various indications, in which most studies reported successful cases, although ineffective claims cannot be ignored. Fully covered self-expandable metal stent, self-expandable metal stent, and silastic esophageal stent were the stent types most used, although different materials and prototypes were reported as well. The number of stents used per patient and the duration of the stenting therapy varied widely (ranging from 1 to 584 days). Such treatments were not standardized because of different factors, such as different tolerance to complications in subjects aged 1 month and 16 years, frequent stent migration requiring removal followed or not by its replacement, different guides provided by each stent manufacturer, and successful healing of esophageal lesions. Different esophageal stents may be a reasonable therapeutic approach for the management of benign esophageal strictures in children and adolescents. We believe that esophagus-sparing methods like stents represent a promising alternative or adjunctive treatment to be considered in pediatrics.

Vena Cava Filters: Toward Optimal Strategies for Filter Retrieval and Patients' Follow-Up

Mortality rates associated with venous thromboembolism (VTE) are high. Inferior vena cava filters (IVCFs) have been frequently placed for these patients as part of their treatment, albeit the paucity of data showing their ultimate efficacy and potential risk of complications. Issues regarding long-term filter dwell time are accounted for in society guidelines. This topic has led to an FDA mandate for filter retrieved as soon as protection from pulmonary embolism is no longer needed. However, even though most are retrievable, some were inadvertently left as permanent, which carries an incremental lifetime risk to the patient. In the past decade, attempts have aimed to determine the optimal time interval during which filter needs to be removed. In addition, distinct strategies have been implemented to boost retrieval rates. This review discusses current conflicts in indications, the not uncommon complications, the rationale and need for timely retrieval, and different quality improvement strategies to fulfill this aim.

Outcomes and Prognosis Factors in Patients With Vena Cava Filters in a Quaternary Medical Center: A 5-Year Retrospective Analysis

BACKGROUND

Indications for inferior vena cava filter (IVCF) placement are controversial. This study assesses the proportion of different indications for IVCF placement and the associated 30-day event rates and predictors for all-cause mortality, deep vein thrombosis (DVT), pulmonary embolism, and bleeding after IVCF placement.

METHOD

In this 5-year retrospective cohort observational study in a quaternary care center, consecutive patients with IVCF placement were identified through cross-matching of 3 database sets and classified into 3 indication groups defined as "standard" in patients with venous thromboembolism (VTE) and contraindication to anticoagulants, "extended" in patients with VTE but no contraindication to anticoagulants, and "prophylactic" in patients without VTE.

RESULTS

We identified 1248 IVCF placements, that is, 238 (19.1%) IVCF placements for standard indications, 583 (46.7%) IVCF placements for extended indications, and 427 (34.2%) IVCF placements for prophylactic indications. Deep vein thrombosis rates [95% confidence interval] were higher in the extended (8.06% [5.98-10.58]) and prophylactic (7.73% [5.38-10.68]) groups than in the standard group (3.36% [1.46-6.52]). Mortality rates were higher in the standard group (12.18% [8.31-17.03]) than in the extended group (7.55% [5.54-9.99]) and the prophylactic (5.85% [3.82-8.52]) group. Bleeding rates were higher in the standard group (4.62% [2.33-8.12]) than in the prophylactic group (2.11% [0.97-3.96]). Best predictors for VTE were acute medical conditions; best predictors for mortality were age, acute medical conditions, cancer, and Medicare health insurance.

CONCLUSIONS

Prophylactic and extended indications account for the majority of IVCF placements. The standard indication is associated with the lowest VTE rate that may be explained by the competing risk of mortality higher in this group and related to the underlying medical conditions and bleeding risk. In the prophylactic group (no VTE at baseline), the exceedingly high DVT rate may be related to the IVCF placement.

Practice Variation in Vena Cava Filter Use Among Trauma Centers in the National Trauma Database

BACKGROUND

Agreement regarding indications for vena cava filter (VCF) utilization in trauma patients has been in flux since the filter's introduction. As VCF technology and practice guidelines have evolved, the use of VCF in trauma patients has changed. This study examines variation in VCF placement among trauma centers.

MATERIALS AND METHODS

A retrospective study was performed using data from the National Trauma Data Bank (2005-2014). Trauma centers were grouped according to whether they placed VCFs during the study period (VCF+/VCF-). A multivariable probit regression model was fit to predict the number of VCFs used among the VCF+ centers (the expected [E] number of VCF per center). The ratio of observed VCF placement (O) to expected VCFs (O:E) was computed and rank ordered to compare interfacility practice variation.

RESULTS

In total, 65,482 VCFs were placed by 448 centers. Twenty centers (4.3%) placed no VCFs. The greatest predictors of VCF placement were deep vein thrombosis, spinal cord paralysis, and major procedure. The strongest negative predictor of VCF placement was admission during the year 2014. Among the VCF+ centers, O:E varied by nearly 500%. One hundred fifty centers had an O:E greater than one. One hundred sixty-nine centers had an O:E less than one.

CONCLUSIONS

Substantial variation in practice is present in VCF placement. This variation cannot be explained only by the characteristics of the patients treated at these centers but could be also due to conflicting guidelines, changing evidence, decreasing reimbursement rates, or the culture of trauma centers.

Retrievable Inferior Vena Cava Filters: A Tertiary Centre Perspective and Quality Assurance Study

Purpose

To conduct a retrospective review and quality assurance study of inferior vena cava (IVC) filter retrieval over a two-year period at a tertiary care centre.

Methods

Patients who underwent IVC filter placement or retrieval over a two-year period were identified. Medical records were reviewed for patient characteristics, filter indication, time to filter retrieval, and complications.

Results

IVC filters were placed in 229 patients between January 1, 2015 and December 31, 2016. 113 retrievals were attempted and 101 filters were successfully retrieved (89.4%). Median time to first retrieval attempt was 48 days (range of 5–728). Seventy-one patients died in the interval after filter insertion before a retrieval attempt at a median time of 27 days (range of 3–430). In 17 patients, retrieval was complicated by or delayed because of penetration of IVC wall (n = 6), large thrombus burden trapped by filter (n = 5), filter tilt or migration (n = 3), and unclear reasons (n = 3). Time-to-first unsuccessful retrieval attempt was 141 days (median). Of all filters placed, 55.9% were never retrieved. Excluding deceased patients with in-situ filters (n = 71) and unsuccessful retrievals left in-situ as permanent filters (n = 5), there remains 52 patients (33%), with a median filter in-situ time of 488 days.

Conclusion

Our study indicates that as many as 33% of patients may have been lost to follow-up of their in-situ IVC filter. Considering widespread reports of long-term complications and the recent safety alert issued by Health Canada, it is evident that a unified strategy is needed to track patients post filter insertion.

Inferior Vena Cava Filters: Current Indications, Techniques, and Recommendations

The vena cava filter (VCF) is intended to prevent the progression of deep venous thrombosis to pulmonary embolism. Recently, the indications for VCF placement have expanded, likely due in part to newer retrievable inferior vena caval filters and minimally invasive techniques. This article reviews the available VCFs, the indications for use, the techniques for placement, and possible outcomes and complications.

Use of inferior vena cava filters in a tertiary referral centre in Australia

INTRODUCTION

To investigate the use of inferior vena cava (IVC) filters in a tertiary referral centre, looking at indication, types of filters and, with temporary/optional filters, removal rates.

METHODS

Data was collected from a prospective database of all IVC filters inserted from January 2003 to January 2007. Patients' records and radiological imaging were all reviewed.

RESULTS

66 patients (40 males) had IVC filters inserted during the study period. The median age of the male patients was 57.5 (21-79) years, and females 56 (24-81). There were 49 (74.2%) temporary/optional filters and 17 (25.8%) permanent filters. The most common indication for filter was a contraindication to anticoagulation for both permanent (64.7%) and temporary/optional filters (77.6%). In the temporary/optional filter group, 38 of 49 (77.6%) patients had documented venous thromboembolism, while in the permanent filter group, this was 14 of 17 (82.4%). Of the optional filters, 22 of 49 (45.8%) have been removed.

CONCLUSION

More than half (54.2%) of temporary/optional filters were not removed and with potential for long-term complications. A protocol has now being instituted for vascular surgeons to authorize the insertion of filters and to then be responsible for ensuring their removal.