According to the Center for Disease Control and Prevention, deep venous thrombosis (DVT) and pulmonary thromboembolism (PTE) affects approximately 900,000 patients annually in the United States (CDC). Patients presenting with DVT/PTE have an associated mortality burden of 6-10% with up to 25% of patients experiencing sudden death.1,2 Additionally, PTE is associated with chronic thromboembolic pulmonary hypertension (CTEPH), a debilitating morbidity affecting 3-5% of patients experiencing PTE.3,4 In light of these outcomes related to acute PTE, therapeutic, pharmacological anticoagulation should be initiated, if not contraindicated, to prevent thrombus propagation and circumvent the significant morbidity and mortality associated with this diagnosis.2,5-7

Systemic anticoagulation has remained the primary treatment modality in all patients presenting with acute DVT/PTE. Additionally, chemoprophylaxis in patients high-risk for DVT/PTE in the postoperative setting or following major trauma decreases the risk of provoked DVT/PTE.2,5-8 Patients with contraindications to anticoagulation or who are at high risk for PTE require alternative means of therapy. Inferior vena cava filters (IVCFs) present a mechanical prophylaxis against subsequent PTE secondary to DVT in patients unable to tolerate anticoagulation. IVCF deployment is a relatively low-risk procedure that can be performed in a variety of settings in critically ill patients.8

To assist in guiding management strategies, multiple academic societies including the Society of Interventional Radiology (SIR), Society for Vascular Surgery (SVS), the American Society of Hematology, and the American College of Chest Physicians (ACCP) have collaborated to develop evidence-based guidelines for IVCF utilization.2,9 To further delineate the appropriate use of IVCFs, the American College of Radiology (ACR) released appropriateness guidelines for use of IVCFs addressing a variety of clinical scenarios.6,7 In this chapter, we provide a comprehensive review of the literature and discuss the current evidence-based and appropriateness guidelines regarding IVCF utilization (Table 1).

IVCFs are divided into two categories based on filter design: permanent IVCF (pIVCF) and optional (retrievable) IVCF (oIVCF). IVCFs were developed in the 1970s as a means for mechanical thromboembolic prophylaxis in high-risk patients.12 The original design was a conical, bare metal device without a design feature allowing endovascular retrieval.12 In the early 2000s, oIVCFs were FDA approved for both temporary and permanent mechanical thromboembolic prophylaxis.13,14 The oIVCF design incorporates an endovascular retrieval system that provides a minimally invasive mechanism for device removal.13 oIVCFs were developed to provide a temporary means of mechanical PTE prevention in patients unable to be anticoagulated with the intention of retrieval following resolution of the patient's condition necessitating thromboembolic protection.

An additional subset of oIVCFs are convertible IVCFs. Convertible IVCFs are designed with a feature that allows in situ conversion from a thromboembolic filtration device to a non-filtering, permanent implant. The utilization of this subset of IVCFs has increased since FDA-approval of the initial convertible IVCF in 2016.15-18 The first commercially available convertible IVCF was the VenaTech convertible IVCF (B. Braun Interventional Systems, Bethlehem, PA). The design of this device incorporates an IVCF embedded within a self-expanding IVC stent.18 The central filter component can be removed through an additional endovascular procedure following the mitigation of the need for mechanical thromboembolic protection.17,18 After removal of the central filter, a IVC stent remains permanently implanted. Overall, adverse event rates at 6-months are low using the VenaTech convertible IVCF. There are two other FDA-approved convertible IVCFs. The Sentry IVCF (BTG Vascular, Bothell, Washington) is designed for transient mechanical thromboembolic protection (<60 days) with a bioconvertible central filter component that is biodegraded after 60 days.15 The unique biodegradable design obviates the need for additional procedures for retrieval. The nitinol scaffolding remains as a permanent implant. Results using this device have been excellent with a successful bioconversion rate >95%.15 Lastly, the Angel IVCF (Bio2 Medical, San Antonio, Texas) is considered a convertible device. This IVCF is remains attached to a central venous catheter after deployment that allows for expeditious removal at bedside, which avoids an additional endovascular procedure.16 Due to limited use compared to pIVCFs and other oIVCFs, convertible devices have not been explicitly incorporated into societal guidelines.

Following the development of oIVCFs, clinical indications for IVCF deployment were expanded to include prophylactic deployment in select patient groups.2,9,10 Due to these liberalized indications, IVCF deployment exponentially increased peaking in the early 2000s. Approximately 65,000-95,000 IVCFs are deployed annually as prophylactic or therapeutic thromboembolic protection in high-risk patients.19,20

Following FDA approval, the exponential increase in oIVCF deployment as thromboembolic prophylaxis was associated with rising complication rates and low retrieval rates (<50%).13,21,22 Complications directly related to IVCFs are associated with prolonged dwell time defined as greater than 90-days.23,24 Studies investigating increased IVCF usage revealed that oIVCFs were deployed in 75% of cases while comprising 95% of adverse events involving device fracture or migration.25,26 In response to the increasing incidence of adverse events related to prolonged dwell time and concerns regarding oIVCF overuse, the US-FDA issued a safety communication in 2010 to decrease IVCF overuse and improve surveillance of patients after oIVCF deployment.13 An additional US-FDA issuance in 2014 addressed the need for emphasized the importance of post-operative monitoring and IVCF retrieval.14 As a result, oIVCF deployment decreased in subsequent years, and clinical guidelines were developed to facilitate appropriate utilization of IVCFs (Table 1).2,10

In addition to the FDA issuance from 2010 and 2014, alterations in reimbursement patterns have also significantly affected IVCF deployment.27-31 Following the release of societal guidelines and the FDA warnings, the Centers for Medicare and Medicaid Services lowered the institutional reimbursement for IVCF deployment.28,30 This was accomplished by bundling the traditionally utilized Current Procedural Terminology (CPT) codes that amounted to 15.7 Relative Value Units (RVUs) into a single CPT code amounting to 4.7 RVUs. This near 70% reduction in reimbursement for IVCF placement was in attempt to disincentivize IVCF utilization.30 Multiple studies have demonstrated a correlation between the significant decrease in IVCF deployment and decline in IVCF use after 2012.27,28,30,31 Although there is clear association between IVCF reimbursement reduction and decline in IVCF utilization, it is likely a combined effect of increased awareness among providers, FDA issuance, and dissemination of societal guidelines.31

Despite the widespread usage of IVCFs, evidence-based guidelines and academic societal consensus are derived from a limited number of prospective randomized controlled trials (RCT). Current evidence-based guidelines were developed by multi-societal efforts through comprehensive literature review and expert multidisciplinary panel consensus.2 Although evidence-based guidelines exist, variations in IVCF utilization still exist across different specialties, regions, and institutions.6,7,32-34 Evidence-based guidelines from multiple societies are recorded in Table 1.

Therapeutic indications for IVCF deployment include patients with acute proximal DVT or PTE with or without absolute contraindications to therapeutic anticoagulation. Additionally, IVCFs may be indicated as treatment for DVT/PTE in patients with severe complications from anticoagulation such as major hemorrhage, heparin-induced thrombocytopenia, or those with refractory PTE despite anticoagulation.6,7,37 An algorithm representing appropriateness guidelines for therapeutic IVCF utilization is presented in Figure 1.

Due to the high morbidity and mortality associated with PTE, the primary indication for IVCF deployment remains as primary or secondary PTE prevention in patients presenting with DVT/PTE who have contraindications to anticoagulation.2,6,7,38 Current evidence-based guidelines have been derived from relatively low to moderate quality studies in the absence of large RCTs.2

In a single-center retrospective study, White and colleagues demonstrated no survival benefit in patients who received an IVCF without contraindication to anticoagulation.33 However, patients unable to be anticoagulated due to major surgery or those with active bleeding experienced a reduction in all-cause mortality of 32% and 27% at 30 and 90-days, respectively.33 The study also demonstrated a 135% increase in recurrent DVTs and no significant difference in recurrent PTE rates when comparing IVCF and non-IVCF groups.33 In a subgroup analysis of a study investigating the effects of IVCF on in-hospital mortality in trauma patients, patients with DVT/PTE experienced no benefit from IVCF placement. Lastly, through collaborative efforts by the SVS and SIR, the recently published PRESERVE trial (Predicting the Safety and Effectiveness of Inferior Vena Cava Filters) consisting of 1,429 patients receiving IVCFs due to contraindications to anticoagulation revealed a 1.6% recurrent PTE rate, 5.2% DVT rate, and device related complications ranging from 0.5% to 1.1%.38

Multiple systematic reviews and meta-analyses have corroborated the effective prevention of primary or secondary PTEs in patients receiving IVCFs who are unable to tolerate anticoagulation.5,8,11,39,40 These reports revealed significantly lower PTE incidence in IVCF groups compared to non-IVCF patients ranging from 1-2%.5,11,39 However, these studies also demonstrated an increased rate of recurrent DVT in the IVCF groups as high as 8.1% at 30-days and 21% at 3-years.5,11,39 Although results remain variable, in their prospective study of over 40,000 patients presenting with DVT/PTE with contraindications to anticoagulation, Muriel and colleagues demonstrated significant decrease in PTE-related 30-day mortality in the IVCF group (4.9% vs 1.7%; p=0.03) and a trend toward improved all-cause mortality (6.6% vs 10.2%; p=0.12).39 In a meta-analysis of 6 RCTs and 5 prospective studies, Bikdeli and colleagues revealed similar findings with significantly lower recurrent PTE, higher recurrent DVT rate, and no difference in all-cause or PTE-related mortality in the IVCF group.40

Although results are variable, evidence-based guidelines and appropriateness guidelines endorse routine utilization of IVCFs in patients presenting with DVT/PTE with contraindications to anticoagulation.2,6,7,41 Due to the increased risk of filter related complications related to prolonged dwell time observed in oIVCFs, current appropriateness guidelines suggest that pIVCFs might be appropriate in patients in need of prolonged or lifelong mechanical thromboembolic protection.6,7

Anticoagulation as the first-line management in patients presenting with DVT/PTE without contraindication remains the consensus among multiple societal guidelines.41 Additionally, routine use of IVCFs and anticoagulation as combined thromboembolic protection is uniformly discouraged by current guidelines (Figure 1).41 The prospect of utilizing IVCFs as adjuvant thromboembolic prevention against index PTE in patients presenting with DVT was initially studied in the PREPIC trials (Prevention du Risqué d'Embolie par Interruption Cave).42-44 Through randomizing 400 patients to either anticoagulation alone or combined anticoagulation and pIVCF deployment, the initial PREPIC trial demonstrated a short-term benefit in the combined therapy group compared to the anticoagulation alone group regarding the occurrence of PTE (4.8% vs 1.1%; p=0.05). However, mid-term recurrent DVT rates were higher in the filter group at 20.8% compared to 11.6% in the non-filter group. A follow-up study investigating long-term outcomes of the PREPIC trial cohorts revealed similar findings at 8-years.42 Neither study demonstrated a survival benefit related to IVCF in the short or long term.43,44

Other studies have investigated the efficacy of IVCFs in the prevention of secondary PTE in patients with diagnosed, clinically significant PTE.43,45 The PREPIC2 trial randomized 399 patients hospitalized with severe PTE to anticoagulation alone and anticoagulation with adjuvant oIVCF. The IVCF group experienced a recurrent PTE rate of 3.0% compared to 1.5% in the anticoagulation cohort (p=0.5).43 Additionally, the authors observed no differences in mortality or recurrent DVT rates. Systematic reviews and meta-analyses have further corroborated these findings.5,40 A national data registry study consisting of 13,125 patients presenting with symptomatic PTE identified IVCFs as a protective factor against in-hospital mortality in multivariable regression analysis.45 Other studies utilizing the National Inpatient Sample (NIS) data repository revealed a marginal decrease in in-hospital mortality in patients receiving IVCFs of 0.7%.46

Multiple societal evidence-based guidelines and the appropriateness guidelines from the ACR recommend against the use of IVCFs in conjunction with anticoagulation when treating acute DVT or PTE. However, the ACR guidelines stipulate that IVCFs as adjuvant thromboembolic protection may be appropriate for high-risk patients in specific clinical scenarios.6,7

Specific groups of patients with extensive cardiopulmonary comorbidities merit special consideration regarding IVCF deployment (Figure 1). Studies utilizing large-scale patient data from national registries have investigated the effects of IVCF placement in select patient groups. Patients with poor cardiopulmonary reserve are of particular concern due to concerns regarding the ability to tolerate additional physiological insult of recurrent PTE.47 Additionally, patients with cardiopulmonary disease such as CHF or COPD are at higher risk for index and recurrent PTE compared to the general population.47 In a study including over 400,000 patients, Wadwha and colleagues demonstrated a significant in-hospital mortality advantage in CHF patients presenting with PTE who received IVCFs compared to those who did not (9.7% vs 12.2%; p<0.001).47 Utilizing a similar large patient cohort, Stein and colleagues demonstrated a comparable mortality advantage in COPD patients over 50 years of age who presented with symptomatic PTE (8.7% vs 11.0%; p<0.0001).48 However, this study was limited in that the authors only considered all-cause mortality and other treatment modalities such as anticoagulation could not be delineated.47

Other patient characteristics of concern when considering IVCF placement include advanced age, chronic thromboembolic pulmonary hypertension (CTEPH) and hemodynamic instability. Studies evaluating the efficacy of IVCFs in elderly patients (>65 years) have produced variable results.49,50 A study appraising IVCF usage in Medicare patients (>65 years) revealed no survival advantage in patients receiving IVCFs at 30-days or 1-year after initial presentation.51 In sub-group analysis, patients over 85 years old experienced the highest incidence of IVCF placement and the highest mortality burden at 1-year (33-37%).51 In their study utilizing the National Inpatient Sample data registry (NIS) Stein and colleagues demonstrated a 5.3% reduction in in-hospital mortality in patients of advanced age (>80 years) with DVT/PTE receiving IVCF compared to those without IVCF.49 This risk reduction was further augmented in elderly patients presenting with hemodynamic instability who required advanced therapies such as thrombolytic therapy.52

Multiple studies have investigated the effect of IVCF placement in patients presenting with hemodynamic instability secondary to massive PTE who require advanced therapies such as thrombolytics or pulmonary embolectomy.50,53 In their study incorporating over 21,000 patients from the NIS registry from 1999-2008, Stein and colleagues, demonstrated an absolute risk reduction of 10.0% of in-hospital mortality in unstable patients receiving an IVCF.54,55 These results were corroborated by a second study by Stein and colleagues utilizing the Premier Healthcare Database.50,56 Significantly lower all-cause mortality was observed in the IVCF group compared to no IVCF (21% vs 48%). A follow-up study using the NIS registry from 2009-2012 revealed no significant association between IVCF and improved in-hospital mortality compared to no IVCF.53

Currently, no RCTs have been performed to corroborate the findings of prior observational studies in these patient populations. Furthermore, there are no definitive recommendations regarding filter type (optional vs permanent) in these scenarios. Due to variable results across studies in these patient sub-groups, current evidence-based guidelines recommend IVCF placement in select patients after adequate risk stratification by a multidisciplinary team.2 Although no robust evidence is currently available, current appropriateness guidelines from the ACR recommend that IVCF placement as adjuvant therapy to anticoagulation might be appropriate in these select patient populations given that the risks do not outweigh the benefits.6,7

A systematic review assessing 69 articles consisting of RCTs and prospective observational studies demonstrated a DVT/PTE recurrence rate of 0.4% (CI 0.3%-0.6%) in patients receiving anticoagulation with a moderate associated mortality rate of 11.3% (CI 8.0%-15.2%).57 Other studies have indicated a recurrence rate as high as 2.0% in patients initiated on enteral anticoagulation agents.58 Although recurrence of DVT or PTE while therapeutically anticoagulated is considered a failure of anticoagulation, all potential physiological explanations of therapy failure should be explored prior to IVCF consideration.2,6,7 These include evaluating patients for hypercoagulable disorders such as antiphospholipid syndrome, protein C or S deficiency, and malignancy.2,6,7 Providers should also assess patient compliance with current medication and attempt alternative therapy with low molecular weight heparin prior to IVCF placement.59 A propensity matched study consisting of 606 patients with recurrent DVT/PTE within 3-months of anticoagulation initiation demonstrated no survival advantage in patients receiving IVCFs (17.7%) compared to no IVCF (12.2%) (p=0.56).58 When excluding recurrent DVT and examining only patients with recurrent PTE, PTE-related mortality was significantly lower in the IVCF group (2.1% vs 25.3%; p=0.02) with a trend toward decreased all-cause mortality (2.1% vs 17.6%; p=0.08).58 These findings were corroborated in a study by Stein and colleagues demonstrating a PTE-related mortality benefit in the IVCF group (3.0%) compared to non-IVCF group (39.3%).60

Given the paucity of research, current evidence-based guidelines and expert consensus recommend against routine IVCF placement in patients with recurrent DVT/PTE with modifiable factors causing failure of anticoagulation.2 In patients with non-modifiable factors contributing to failure of anticoagulation, ACR appropriateness guidelines suggest that oIVCF is usually appropriate to prevent subsequent PTE.6,7 In patients with suspected long-term need for PTE thromboprophylaxis, pIVCF is more appropriate (Figure 2).6,7

Cancer patients are of particular concern regarding utilization of IVCFs due to the hypercoagulable state associated with active malignancy.61 Studies have indicated that the risk for DVT/PTE increases by 4-7-fold compared to the general population and incurs a significant mortality burden.62,63 Studies have indicated that cancer patients have a higher propensity to receive IVCFs due to contraindications to anticoagulation or failure of therapy compared to the general population.63 However, studies have indicated only 21% of cancer patients receiving IVCFs harbor major contraindications to anticoagulation.64

Several studies have evaluated the effectiveness of IVCFs combined with anticoagulation in cancer patients.61 In an RCT consisting of 64 patients with active malignancy presenting with DVT or PTE, patients were randomly assigned to IVCF or IVCF in addition to fondaparinux.61 The study demonstrated no benefit regarding PTE/DVT recurrence, all-cause mortality, or PTE-related mortality in the IVCF group.61 Other studies utilizing large national data registries have demonstrated reduction of in-hospital mortality ranging from 3.8-4.7%.65,66 However, due to limitations of the data registries, the indication for IVCF placement and the use of concomitant anticoagulation was unclear, which limits the generalizability of these studies. Another study utilizing large-scale administrative claims data revealed that cancer patients receiving IVCFs following DVT experienced significantly improved PTE-free survival (94% vs 89%; p<0.001). This study used propensity matching to adjust for patients receiving combined IVCF and anticoagulation as therapy.62 Meta-analysis of 7 studies including RCTs and observational studies demonstrated no survival or PTE preventative benefit in cancer patients undergoing IVCF placement.67

Due to the variability in results, evidence-based guidelines advocate for the use of low molecular weight heparin in cancer patients presenting with DVT while reserving IVCFs for patients with contraindications to anticoagulation or who fail anticoagulation.2,67 Current appropriateness guidelines recommend a multidisciplinary and prognostic evaluation of cancer patients prior to IVCF placement. In select cancer patients presenting with DVT/PTE unable to tolerate anticoagulation, IVCF placement might be appropriate.6,7

Utilization of IVCFs have extended to patients with concerning morphological characteristics of proximal DVT such as free-floating IVC thrombus. The prevalence of IVC free-floating in proximal DVTs has been estimated to be approximately 1.7%.68 Risk of PTE secondary to free-floating IVC thrombus ranges from 13% to 43%.68,69 No studies have specifically addressed the employment of IVCF as adjuvant therapy in treating free-floating thrombus.8 However, current appropriateness guidelines and prior evidence-based guidelines consider free-floating thrombus a relative indication for IVCFs.6-8

In patients undergoing endovenous embolectomy or thrombolysis of iliofemoral DVTs, temporary IVCFs have been employed with variable results. One study consisting of 80 patients undergoing thrombolysis for iliofemoral DVTs revealed no significant difference in PTE-related events but demonstrated 22% of patients with embolized thrombus collected in the IVCF.70 The filter implantation to lower thromboembolic risk in percutaneous endovenous intervention trial (FILTER-PEVI) randomized 141 patients to receive an IVCF prior to embolectomy or thrombolysis. The authors demonstrated a significantly lower incidence of symptomatic PTE in patients with oIVCF at 1.4% compared to 11.3% in the non-IVCF group (p=0.048).71 A large study of over 7,000 patients utilizing the NIS registry revealed that IVCFs are deployed in 34% of patients undergoing PEVI for DVT. This study demonstrated no mortality or PTE-related differences between groups but noted a longer length of stay and hospital costs in the IVCF group.72 In concordance with evidence-based guidelines, current appropriateness guidelines suggest that IVCFs might be appropriate in patients undergoing endovenous procedures for DVT (Figure 1).

Pregnancy induces a hypercoagulable state resulting in an incidence of DVT/PTE ranging from 0.5%-1.0%.73 The widely accepted therapy for DVT/PTE in pregnancy is therapeutic anticoagulation with unfractionated heparin.6,7,73 Generally, the indications for IVCF placement in pregnancy are equivalent to the general population. Overall, studies have indicated successful utilization of IVCFs in this patient population with low rates of maternal or fetal mortality/morbidity.73 Studies have primarily focused on employing IVCFs at time of delivery or Cesarean-section when bleeding risk is augmented, and anticoagulation is withheld.73 A small retrospective study evaluating 24 patients revealed a higher rate of PTE in pregnant patients presenting with DVT who received low molecular weight heparin without an IVCF (13%) compared to patients with an IVCF and low molecular weight heparin.74 However, no RCTs have been conducted demonstrating benefit of IVCF and current evidence-based guidelines do not address this patient population.2,73 If utilized in pregnant patients, IVCFs are typically deployed in the suprarenal IVC to avoid compression by the gravid uterus in the infrarenal position.73 Overall, current appropriateness guidelines suggest IVCF placement in pregnant women might be appropriate in certain circumstances.6,7

The advent of oIVCFs expanded the potential indications for IVCF to prophylactic thromboprophylaxis in patients considered high risk for developing DVT/PTE with contraindications to prophylactic anticoagulation. Results have been variable regarding prophylactic use of IVCFs, and studies have primarily focused on patients with traumatic injuries precluding anticoagulation.39,40,75 Due to these variable results, the current evidence-based guidelines do not support the routine use of IVCFs as prophylactic thromboprophylaxis.2 In the following section, we present an overview of the current appropriateness guidelines and associated supporting literature regarding prophylactic IVCF usage (Figure 3).

Employment of IVCFs as primary thromboprophylaxis has predominantly been studied in polytrauma patients.75-77 Patients experiencing polytrauma are high-risk for DVT/PTE due to immobility or coagulopathy and often have contraindications to prophylactic anticoagulation such as increased bleeding risk or intracranial hemorrhage.8 Reports estimate an incidence of DVT/PTE in trauma patients unable to tolerate prophylactic anticoagulation as high as 50%.8 Although practice patterns are highly variable across different institutions, studies have demonstrated that 0.6-9.8% of trauma patients will undergo IVCF placement.8 Patients with spinal cord injury or lower extremity injuries are at highest risk for DVT/PTE due to prolonged immobilization.6,7

In a multi-institutional RCT consisting of 240 polytrauma patients, oIVCFs were placed in 122 patients within 72 hours of presentation in patients with contraindications to anticoagulation. The study revealed no difference in a composite outcome of PTE and mortality when comparing IVCF and non-IVCF groups.75 However, sub-group analysis revealed that patients receiving an IVCF with a contraindication to prophylactic anticoagulation extending beyond 7-days experienced no PTE compared to 14.7% of similar patients without IVCF.75 This study suggested that IVCFs should be considered in select trauma patients with prolonged contraindication to prophylactic anticoagulation.75 Another study utilizing the NIS data registry demonstrated a slightly lower mortality rate in trauma patients with prophylactic IVCFs at 1.0% compared to 2.7% in non-IVCF patients.78 Other observational studies have demonstrated no significant mortality benefit of prophylactic IVCF placement in trauma patients.79 In a meta-analysis consisting of 10 observational studies and RCTs, Shariff and colleagues demonstrated that IVCFs provide a significant benefit in preventing symptomatic PTEs in trauma patients (RR: 0.27, CI 0.12-0.58).80 Other meta-analysis and systematic reviews have corroborated the efficacy of IVCFs in the successful reduction of subsequent symptomatic PTE in trauma patients undergoing temporary IVCF placement.77,81,82

Current evidence-based guidelines do not support the routine utilization of IVCFs as primary thromboprophylaxis in trauma patients due to lack of evidence supporting a mortality benefit.2 Current appropriateness guidelines recommend initiation of pneumatic compression devices and prophylactic anticoagulation when feasible.6,7 Based on currently available evidence, appropriateness guidelines stipulate that oIVCFs may be appropriate in trauma patients with high-risk injury patterns who have contraindications to anticoagulation.6,7

Bariatric patients undergoing weight-loss operations are considered high-risk for developing DVT and PTE with PTE accounting for 40% of perioperative mortality.83,84 The American Society for Metabolic and Bariatric Surgery endorses the use of IVCFs as thromboprophylaxis only in patients who are at exceedingly high risk for developing DVT/PTE.84 According to the NIS registry, only 0.41% of all bariatric surgical patients are treated with prophylactic IVCFs.85 Descriptive studies have demonstrated low rates of PTE (1%) and DVT (3%) in high-risk bariatric patients receiving prophylactic IVCF and chemoprophylaxis.84 A meta-analysis including seven observational studies revealed higher mortality and DVT rates with no benefit in PTE prevention associated with prophylactic IVCFs.83 Systematic reviews have revealed variability in results and practice-patterns without definitive results.86

Current evidence-based guidelines to not endorse IVCF placement as thromboprophylaxis in patients undergoing bariatric procedures.2 Patients should be treated with chemoprophylaxis when feasible. Appropriateness guidelines state that prophylactic IVCF placement is usually not appropriate in this patient population.6,7

Patients undergoing orthopedic surgery such as spinal operations or total hip arthroplasty are at increased risk for DVT/PTE due to prolonged operative time and postoperative immobilization.6,7 Studies evaluating the efficacy of prophylactic IVCF in orthopedic patients are primarily retrospective analyses. One observational study consisting of 121 patients undergoing total hip or knee arthroplasty revealed significantly lower postoperative PTE rates in high-risk patients treated with combined therapeutic anticoagulation (warfarin for 21 days) and IVCF compared to anticoagulation alone (0.8% vs 5.5%; p=0.028).87 In this study, patients with prior episodes of DVT/PTE were considered high-risk. There was no significant difference in the rate of DVT/PTE in low-risk patients. A meta-analysis investigating “ultra-high-risk patients” undergoing lower extremity joint arthroplasty demonstrated comparable results.88 However, among studies, 25% of patients did not undergo attempted IVCF retrieval.

In patients undergoing major spinal surgery, results regarding IVCF use are variable. These patients are challenging as spinal surgery is considered a contraindication to anticoagulation.89 This can delay the initiation of chemoprophylaxis by 4-7 days.89 In their descriptive cohort study, McClendon and colleagues revealed a lower PTE rate at 3.6% in patients receiving IVCFs compared to a control population (OR 3.7; p=0.002).89 A recent study comparing spinal surgery patients receiving prophylactic IVCF in addition to chemoprophylaxis to patients with no IVCF revealed no significant benefit regarding PTE rates (8.6% IVCF vs 4.6% non-IVCF; p=0.32) or perioperative mortality (2.3% in both groups).90 Additionally, IVCF use was associated with higher rate of DVT (8.6% vs 2.6%; p=0.04) with a device-related complication rate of 11%.90 Overall, more robust data in the form of RCTs is required in this patient population prior to definitive recommendations.

Due to the paucity of quality evidence, current evidence-based guidelines do not support the utilization of prophylactic IVCFs in patients undergoing orthopedic surgery.2,41 Appropriateness guidelines primarily suggest prophylactic chemoprophylaxis with the stipulation that prophylactic IVCFs may be appropriate in high-risk patients unable to be anticoagulated.6,7

While the US-FDA issuance in 2010 and 2014 aimed to improve oIVCF retrieval rates, national aggregate retrieval rates remain low at 12-18%.14,24 Recent studies with sufficient follow-up time continue to report a retrieval rate of less than 50% at 1-year after deployment.38 This remains a concern due to the higher risk of device related complications related to prolonged dwell time.23,24 Device-related complications associated with prolonged dwell time include IVC perforation (12.4%-20%), device migration (11.8%), or device fracture (21%). Other long-term complications include recurrent DVT and PTE with prevalence of 1.9%-14.5% and 0.5-12%, respectively.24,25,91 Device fracture, thrombosis, or IVC perforation secondary to prolonged dwell time may potentially preclude successful percutaneous retrieval. Clinical guidelines currently recommend IVCF retrieval of eligible devices following the resolution of contraindications to anticoagulation and mitigation of PTE risk.2

National and institutional data registries have been developed as an effort to improve patient surveillance and IVCF retrieval rates. Historically, patient follow-up post IVCF deployment were unstructured without direct surveillance by the proceduralist. Enrollment of patients into institutional registries and dedicated clinics has proven successful in improving follow-up and IVCF retrieval rates.24,92-94 These studies emphasize the importance of active surveillance to promote IVCF monitoring and ultimate retrieval. In the following section, we summarize current appropriateness guidelines addressing several clinical scenarios.

Postoperative active surveillance of patients after IVCF placement is critical to ensure attempted retrieval. The development of data registries and dedicated IVCF clinics have facilitated improvement in the rate of IVCF retrieval. One study demonstrated an exceedingly low IVCF retrieval rate over a 20-year period (10-15%) prior to developing an institutional registry.92 After implementation of the data registry, IVCF retrieval rates improved to 40% in subsequent years.92 Several other studies have demonstrated improved IVCF retrieval rates and follow-up after the implementation of local patient registries or dedicated clinics with similar success.24,93,94 A similar study directly comparing retrieval rates in a traditional surveillance paradigm to those following implementation of an institutional registry revealed a significant increase in retrieval rates by 12%.24 Others have reported improved retrieval rates up to 92.5% after employing active surveillance through patient registries. Larger scale societal registries such as the Cardiovascular and Interventional Radiology Society of Europe (CIRSE) have achieved an IVCF removal rate of 92% in eligible devices.95 Current guidelines recommend enrolling patients in institutional registries or dedicated IVCF clinics to facilitate close follow-up and improve retrieval once appropriate (Figure 4).2

Current evidence-based guidelines and appropriateness guidelines recommend IVCF retrieval in patients with eligible devices following resolution of required thromboembolic protection.2,6,7,41 Generally, successful retrieval utilizing standard endovascular techniques can be accomplished in 82% of cases with low complication rate.23 Failure of standard retrieval techniques, however, increase exponentially with increasing dwell time.70,95 To prevent complications related to IVCF retrieval, patients with mitigated PTE risk should be evaluated for removal at or prior to 90-days after IVCF insertion. Prior to attempted retrieval, patients should undergo venography to identify presence of IVCF thrombus or perforation.2,6,7 Routine Duplex Ultrasonography of the lower extremities or IVC might be appropriate in certain cases if there is concern for recurrent DVT.6,7 If there is adequate access to catheter directed venography, cross-sectional imaging is usually not appropriate prior to retrieval (Figure 4).6,7

Prolonged IVCF dwell time (>7-months) reduces the success rate of standard retrieval techniques to approximately 40% due to device compromise or IVC perforation.23 In cases not amenable to routine retrieval, advanced endovascular retrieval modalities are available and have been employed with success.23 However, advanced techniques require off-label usage of endovascular devices and can lead to a higher rate of complications (∼20%) when compared to standard retrieval procedures.20 When utilized, advanced techniques have a success rate of 85-98%.20,23,94,96 In patients failing advanced techniques, it may be appropriate to convert the filter to permanent to avoid potential complications.6,7 Due to the possibility of unanticipated complications, advanced techniques for IVCF should be performed at high-volume institutions with the capability to manage potential complications.

Permanent IVCFs were not designed for percutaneous retrieval and require advanced techniques in attempted retrieval. Small case series employing advanced techniques have been conducted demonstrating successful retrieval of pIVCFs even after prolonged dwell times.97 However, due to potential for complications, current evidence-based guidelines recommend against routine retrieval of pIVCFs even if indication for mechanical thromboembolic protection has resolved.2,5 Although data remains variable, some studies have demonstrated decreased risk of IVC thrombus with resumption of anticoagulation in eligible patients with indwelling IVCF.98 Currently, no RCTs have been conducted to address this issue. Altogether, patient selection when considering permanent IVCFs is critical and are usually only appropriate in patients requiring life-long thromboembolic protection without ability to tolerate anticoagulation or with previous failure of anticoagulation.2,6,7 Referral for open surgical retrieval of IVCFs is usually not appropriate unless filters become symptomatic or are associated with significant IVC perforation with arterial or adjacent organ involvement (Figure 4).6,7