Impact of Inferior Vena Cava Filter Placement on Short-Term Outcomes in Patients with Acute Pulmonary Embolism

Appropriateness guidelines for inferior vena cava filter utilization: A contemporary review

Concern regarding the exponential increase in optional utilization of inferior vena cava filters (IVCFs) in the early 2000s with a persistent low retrieval rate nationwide has resulted in increased scrutiny regarding clinical application of IVCFs. IVCFs are used in a variety of clinical scenarios, ranging from thromboembolic protection in patients with deep venous thrombosis and contraindication to anticoagulation to prophylactic deployment in multitrauma and critically ill patients. Evidence supporting IVCFs as mechanical thromboembolic protection in certain clinical scenarios has been established through evidenced-based guidelines. As an adjunct to evidence-based guidelines, appropriateness criteria to address specific clinical scenarios and facilitate clinical decision making when considering placement of an IVCF have been developed. In this review, current evidence-based and appropriateness guidelines are summarized.

Percutaneous interventions for pulmonary embolism

Pulmonary embolism (PE) ranks as a leading cause of in-hospital mortality and the third most common cause of cardiovascular death. The spectrum of PE manifestations varies widely, making it difficult to determine the best treatment approach for specific patients. Conventional treatment options include anticoagulation, thrombolysis, or surgery, but emerging percutaneous interventional procedures are being investigated for their potential benefits in heterogeneous PE populations. These novel interventional techniques encompass catheter-directed thrombolysis, mechanical thrombectomy, and hybrid approaches combining different mechanisms. Furthermore, inferior vena cava filters are also available as an option for PE prevention. Such interventions may offer faster improvements in right ventricular function, as well as in pulmonary and systemic haemodynamics, in individual patients. Moreover, percutaneous treatment may be a valid alternative to traditional therapies in high bleeding risk patients and could potentially reduce the burden of mortality related to major bleeds, such as that of haemorrhagic strokes. Nevertheless, the safety and efficacy of these techniques compared to conservative therapies have not been conclusively established. This review offers a comprehensive evaluation of the current evidence for percutaneous interventions in PE and provides guidance for selecting appropriate patients and treatments. It serves as a valuable resource for future researchers and clinicians seeking to advance this field. Additionally, we explore future perspectives, proposing "percutaneous primary pulmonary intervention" as a potential paradigm shift in the field.

Effectiveness and Safety of Large-Bore Aspiration Thrombectomy for Intermediate- or High-Risk Pulmonary Embolism

PURPOSE

To evaluate effectiveness and safety of large-bore mechanical thrombectomy of intermediate- or high-risk pulmonary embolism (PE) and factors associated with effectiveness.

MATERIALS AND METHODS

A retrospective review of 257 patients with intermediate- or high-risk PE who underwent mechanical thrombectomy using the Flowtriever system (Inari Medical, Irvine, California) between July 2019 and November 2021 was conducted. Data were analyzed using the linear regression and Kaplan-Meier methods with a Type 1 error set at 0.05.

RESULTS

Patients' mean age was 62 years, and 51% were male. PE risk was classified as high, intermediate-high, and intermediate-low in 37 (14%), 201 (78%), and 18 (7%) of the patients, respectively. Procedural technical success was 100%. The mean pulmonary artery pressure (MPAP) decreased from a mean of 32 mmHg (SD ± 9) before to 24 mmHg (SD ± 9) after thrombectomy (mean decrease, 8 mmHg [SD ± 6]; P < .0001). Immediate complications occurred in 2% of the patients. Postprocedural 30-day and all-time PE-attributable mortality in a mean of 1.3-year follow-up was 2% and 6%, respectively. In multivariate analysis, the presence of lower extremity DVT at presentation (β ± SE, -7.60 ± 3.22; P = .019) and a higher prethrombectomy MPAP (β ± SE, -0.19 ± 0.04; P < .001) were associated with lower degrees of decrease in MPAP in the intermediate-high-risk PE group. Among 14 patients with postthrombectomy PE-attributable mortality, 13 had postthrombectomy MPAPs of >20 mmHg.

CONCLUSIONS

Large-bore aspiration thrombectomy is a safe and effective treatment for reducing PAP in patients with intermediate- or high-risk PE. Postthrombectomy MPAPs of >20 mmHg might indicate postthrombectomy PE-attributable mortality in high-risk patients.

Inferior Vena Cava Filters and Complications: A Systematic Review

Inferior vena cava (IVC) filters have been used since the 1960s to treat patients with acute risk of pulmonary embolism (PE) to prevent migration of thrombus by trapping it within the filter. Traditional usage has been in patients with contraindication to anticoagulation that carry a significant mortality risk. In this systematic review, we sought to evaluate complications associated with placement of inferior vena cava filters based on published data from the past 20 years. A search was performed on October 6th, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, using three databases (ProQuest, PubMed and ScienceDirect) for articles published between the dates of February 1, 2002 and October 1, 2022. Results were filtered to include full-text, clinical studies, and randomized trials written in English pertaining to keywords "IVC filter AND complications", "Inferior Vena Cava Filter AND complications", "IVC filter AND thrombosis" and "Inferior Vena Cava Filter AND thrombosis". Articles identified by the three databases were pooled and further screened for relevance based on inclusion and exclusion criteria. Initial search results yielded 33,265 hits from all three databases combined. Screening criteria were applied, with 7721 results remaining. After further manual screening, including removal of duplicate hits, a total of 117 articles were selected for review. While there are no consensus guidelines for best practice, there is compelling evidence that IVC filters can provide significant protection against PE with minimal complications if the treatment window is appropriate. Increase in the variety of filter models has led to broader availability, but skepticism remains about their efficacy and safety, with ongoing controversy surrounding appropriate indications. Further research is needed to establish clear guidelines on appropriate indications for IVC placement and to determine time course of complications versus benefits for indwelling filters.

Society of Interventional Radiology Clinical Practice Guideline for Inferior Vena Cava Filters in the Treatment of Patients with Venous Thromboembolic Disease: Developed in collaboration with the American College of Cardiology, American College of Chest Physicians, American College of Surgeons Committee on Trauma, American Heart Association, Society for Vascular Surgery, and Society for Vascular Medicine

PURPOSE

To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease.

MATERIALS AND METHODS

A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations.

RESULTS

The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations.

CONCLUSIONS

Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population.

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.

Comparison of All-Cause Mortality Following VTE Treatment Between Propensity Score-Adjusted Observational Studies and Matched Randomized Controlled Trials: Meta-Epidemiologic Study

BACKGROUND

It is unknown whether propensity score-adjusted observational studies produce results comparable to those of randomized controlled trials (RCTs) that address similar VTE treatment issues.

METHODS

The PubMed and Web of Science databases were systematically searched for propensity score-adjusted observational studies, RCTs, and meta-analyses of RCTs that estimated all-cause mortality following VTE treatment. After identifying distinct clinical treatment issues evaluated in the eligible observational studies, a standardized algorithm was used to identify and match at least one RCT or RCT meta-analysis publication for paired study design analyses. Meta-analyses were used to summarize groups of studies. Treatment efficacy statistics (relative ORs) were compared between the paired observational and RCT studies, and the summary relative ORs for all study design pairs were also calculated.

RESULTS

The observational and RCT study pairs assessed seven clinical treatment issues. Overall, the observational study-RCT pairs did not exhibit significantly different mortality estimates (summary relative OR, 0.89; 95% CI, 0.32-1.46; I2 = 23%). However, two of the seven treatment issue study pairs (thrombolysis vs anticoagulation for pulmonary embolism; once- vs twice-daily enoxaparin for VTE) exhibited a significantly different treatment effect direction, and there was a substantial (nonsignificant) difference in the magnitude of the effect in another two of the study pairs (rivaroxaban vs vitamin K antagonists for VTE; home treatment vs hospitalization for DVT).

CONCLUSIONS

This systematic comparison across seven VTE treatment topics suggests that propensity score-adjusted observational studies and RCTs often exhibit similar all-cause mortality, although differences in the direction or the magnitude of estimated treatment effects may occasionally occur.

TRIAL REGISTRY

PROSPERO; CRD42018087819; URL: http://www.crd.york.ac.uk/PROSPERO.

Importance of Early Insertion of Inferior Vena Cava Filters in Unstable Patients with Acute Pulmonary Embolism

BACKGROUND

Immortal time bias is a possible confounding factor in cohort studies. In this investigation, we assessed mortality with inferior vena cava (IVC) filters in unstable patients with pulmonary embolism using a design to control for immortal time bias.

METHODS

Data were from the Premier Healthcare Database, 2010-2014. International Classification of Diseases-Ninth Revision-Clinical Modification codes were used. Unstable patients with pulmonary embolism and an admitting diagnosis of pulmonary embolism, as well as a primary diagnosis of pulmonary embolism, were included. A time-dependent analysis was used according to the day of insertion of the IVC filter to control for immortal time bias.

RESULTS

Among all unstable patients, irrespective of the use of thrombolytic therapy, in-hospital all-cause mortality was 35 of 180 (19.4%) in those who received an IVC filter vs 122 of 299 (40.8%) with no filter (P < .0001). Mortality was lower in patients in whom the IVC filter was inserted on days 1 or 2 (on day 1, 21.4% compared with 40.8%, P = .017, and on day 2, 14.8% compared with 29.2%, P = .023), but it was not lower in those in whom the filter was inserted on subsequent days.

CONCLUSIONS

Mortality in unstable patients with pulmonary embolism appeared to be reduced with IVC filters only when the filter was inserted on the first or second day of admission. The design used for these analyses controlled for immortal time bias as a cause of the lower mortality with IVC filters.