Increasing use of vena cava filters for prevention of pulmonary embolism

Inferior vena cava filter use at a large community hospital: a retrospective cohort study

Inferior vena cava (IVC) filters are considered when patients with venous thromboembolism (VTE) develop a contraindication to anticoagulation. Use of IVC filters is increasing, despite associated complications and lack of data on efficacy in reducing VTE-related mortality. We characterized the pattern of IVC filter use at a large community hospital between 2018 and 2022. Specifically, we assessed the indications for IVC filter insertion, filter removal rates, and filter-associated complications. Indications for IVC filters were compared to those outlined by current clinical practice guidelines. We reviewed 120 consecutive filter placement events. The most common indications included recent VTE and active bleeding (40.0%) or need for anticoagulation interruption for surgery (25.8%). Approximately one-third (30.0%) of IVC filters were inserted for indications either not supported or addressed by guidelines. Half (50.0%) of patients had successful removal of their IVC filter. At least 13 patients (10.8%) experienced a filter-related complication. In a large community-based practice, nearly one-third of IVC filters were inserted for indications not universally supported by current practice guidelines. Moreover, most IVC filters were not removed, raising the risk of filter-associated complications, and supporting the need for development of comprehensive guidelines addressing use of IVC filters, and post-insertion monitoring practices.

Delayed Arterial Hemorrhage From a Lumbar Artery Following Inferior Vena Cava Filter Placement: A Case Report

Pulmonary embolism (PE) is a feared complication of deep venous thrombosis (DVT) that can lead to respiratory distress and even death. The mainstay of preventing PE is anticoagulation, but other strategies exist. Inferior vena cava (IVC) filters are an alternative strategy for PE prophylaxis in individuals who may have contraindications to receiving anticoagulation. Although the placement of an IVC filter is a minimally invasive and typically uncomplicated procedure, all procedures have their risks. We present a case of a 35-year-old woman who experienced a rare complication of IVC filter placement and suffered a retroperitoneal hemorrhage. The patient underwent placement of an IVC filter for PE prophylaxis before a scheduled sleeve gastrectomy. Hours after placement, she returned with new symptoms and signs of blood loss. She was found to have a retroperitoneal hematoma due to bleeding from a lumbar artery that was penetrated by a strut of the filter. Arterial hemorrhage from a lumbar artery is a rare complication of IVC filter placement, and it can result in poor outcomes for the patient. We aim to increase awareness of this rare but dangerous complication to improve recognition and patient outcomes in cases of delayed arterial hemorrhage following IVC filter placement.

Retrieval of an inferior vena cava Greenfield filter 34 years after insertion

Inferior vena cava (IVC) filters are engineered medical devices deployed in the IVC primarily to prevent a pulmonary embolism from occurring. In this article, we present a case of an IVC filter that was successfully retrieved from a patient after being in place for 34 years. The patient presented to hospital for trauma in which subsequent imaging showed tines of an IVC filter protruding outside of the vessel with one of the tines penetrating the duodenal wall. The filter was successfully removed with no complications. This report adds to the existing literature by yielding an example of an adverse risk that can be associated with the placement of IVC filters. In addition, to the authors' best knowledge, this is the longest reported length of time that an IVC filter has stayed in a patient before being removed, thus adding another intriguing detail to the case.

Inferior Vena Cava Filter Retrieval: Simple to Complex

Retrievable inferior vena cava filters were designed to provide mechanical prophylaxis from pulmonary embolism with the intent for retrieval once no longer indicated, and have been utilized at a high rate since their introduction. Unfortunately, retrieval rates have historically lagged behind, in part due to significant rates of failed standard retrieval techniques for filters with prolonged dwell time. Refinement in advanced retrieval techniques has now allowed (in experienced centers) for safe removal of filters previously considered irretrievable. An individualized approach is necessary for each potential advanced filter retrieval to determine appropriate course of action. This review will emphasize complex filter retrieval techniques amidst a larger discussion of inferior vena cava filters and their management.

Developmental or Procedural Vena Cava Interruption and Venous Thromboembolism: A Review

The inferior vena cava (IVC) and superior vena cava are the main conduits of the systemic venous circulation into the right atrium. Developmental or procedural interruptions of vena cava might predispose to stasis and deep vein thrombosis (DVT) distal to the anomaly and may impact the subsequent rate of pulmonary embolism (PE). This study aimed to review the various etiologies of developmental or procedural vena cava interruption and their impact on venous thromboembolism. A systematic search was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines per each clinical question. For management questions with no high-quality evidence and no mutual agreements between authors, Delphi methods were used. IVC agenesis is the most common form of congenital vena cava interruption, is associated with an increased risk of DVT, and should be suspected in young patients with unexpected extensive bilateral DVT. Surgical techniques for vena cava interruption (ligation, clipping, and plication) to prevent PE have been largely abandoned due to short-term procedural risks and long-term complications, although survivors of prior procedures are occasionally encountered. Vena cava filters are now the most commonly used method of procedural interruption, frequently placed in the infrarenal IVC. The most agreed-upon indication for vena cava filters is for patients with acute venous thromboembolism and coexisting contraindications to anticoagulation. Familiarity with different forms of vena cava interruption and their local and systemic adverse effects is important to minimize complications and thrombotic events.

Diagnosis and treatment of venous thromboembolism and clinical application of inferior vena cava filter in China

OBJECTIVE

This study investigated the trend of venous thromboembolism (VTE) in China during the past 10 years and assessed the clinical application of inferior vena cava filters (IVCFs).

METHODS

A survey designed to investigate the diagnosis and management of VTE, specifically the application of IVCFs, was distributed nationally from January 2009 to December 2019. The respondents were mainly designated medical professionals and were asked to complete 4 major and 61 minor items in the survey.

RESULTS

A total of 53 medical centers, including 27 radiologic and 26 vascular surgery centers, from 21 provinces in China participated in the study. These centers had diagnosed and treated 171,310 patients with VTE; 83,969 were inpatients (49%). During a 10-year period, an increasing trend of VTE diagnosis and inpatient management, 3.8-fold and 4.8-fold, respectively, was observed. The characteristics of the inpatients were as follows: 15% bilateral lower extremity deep vein thrombosis (DVT), 27% right lower extremity DVT, and 58% left lower extremity DVT. Anticoagulation therapy included unfractionated heparin with vitamin K antagonists (8%), low-molecular-weight heparin (LMWH) with vitamin K antagonists (21%), LMWH with transition to rivaroxaban (34.2%), LMWH with transition to dabigatran (2.4%), rivaroxaban alone (33.4%), and dabigatran alone (1.0%). The percentage of patients continuing anticoagulation therapy at 3, 6, 12, 24, and >24 months was 36%, 35%, 18%, 6.0%, and 5%, respectively. The in-hospital mortality for the patients with VTE was 3.2%, with DVT and pulmonary embolism responsible for 5.2% and DVT alone for 2.7%. Thrombolytic therapy was initiated for 39,046 of 83,969 patients (46.5%), including catheter-directed thrombolysis for 33,189 of the 39,046 patients (85%) and evaluation of the iliac vein using ultrasound and/or venography for 63,816 patients (76%). Urokinase was the main thrombolytic drug used (98%), followed by recombinant tissue-type plasminogen activator. Complete and partial thrombolysis was achieved in 70% and 30% of the patients, respectively. Bleeding complications were observed in 3.5% of patients, and 20% of the patients with bleeding complications required intervention. Between 2009 and 2019, 40,478 IVCFs (76% retrievable) were implanted in hospitalized VTE patients. During the enrollment period, the total number of IVCFs implanted increased by 3.8-fold, with a 4.8-fold increase in retrievable IVCFs and 7.5-fold decline in permanent IVCFs. The removal rate for the retrievable IVCFs was 72%. After IVCF implantation, 94.8% of patients received anticoagulation therapy for an average of 9.1 ± 8.6 months. The overall complication rate associated with IVCF placement was 15.5% (n = 6274 of 40,478 IVCFs), including tilting (54%), vena cava thrombosis (26.1%), caval penetration (12.6%), and migration (7.3%). No IVCF placement-related mortality occurred.

CONCLUSIONS

A significant increase occurred in VTE diagnosis in China during the past decade. Anticoagulation therapy was the mainstay treatment, and catheter-directed thrombolysis was widely used. Most IVCFs placed were retrievable, and the use of permanent IVCFs has largely been discarded.

Retrievable Inferior Vena Cava Filter Trapped Embolus: A Risk Factor of Detachment of Thrombus Analysis Based on a Multicenter Prospective Observational Study

PURPOSE

Up to now, the indications of inferior vena cava filter placement still remain controversial in the academic field. The aim of this study was to determine the risk factors of detachment of thrombus and to evaluate the necessity of inferior vena cava filter placement to prevent fatal pulmonary embolism.

MATERIALS AND METHODS

A total of 2892 patients participated in the multicenter prospective observational study from January 1, 2018, to December 31, 2018, and underwent retrievable inferior vena cava filter (RIVCF) placement in 103 centers in China. The primary endpoint of the study was RIVCF trapped embolus detected by inferior vena cava venography/ultrasound/computed tomography scanning or visible macroscopic thrombus before or during RIVCF retrieval. The relative factors of RIVCF trapped embolus were analyzed accordingly.

RESULTS

The average age of the patients was 61.0 (50.0-71.0) years. Retrievable inferior vena cava filter trapped embolus occurred in 308 patients (10.65%). The fracture location, surgery location, and endovascular intervention differed between RIVCF trapped embolus and non-RIVCF trapped embolus groups (p<0.001, respectively). By multivariate analysis, RIVCF trapped embolus were less common in older patients (odds ratio [OR]=0.998; p<0.001) and more common in patients with below-the-knee fracture (OR=1.093, p=0.038), thigh fracture (OR=1.118, p=0.007), and pelvis surgery (OR=1.067, p=0.016). In addition, compared with patients without endovascular intervention, patients with percutaneous mechanical thrombectomy (PMT) + catheter-directed thrombolysis (CDT) were more prone to develop RIVCF trapped embolus (OR=1.060, p=0.010). However, RIVCF trapped embolus was less common in patients with CDT (OR=0.961, p=0.004).

CONCLUSIONS

Lower limb fracture, pelvis surgery, and PMT + CDT are prone to cause trapped embolus. As a trapped embolus often represents the possibility of severe pulmonary embolism, lower limb fracture, pelvis surgery, and PMT + CDT could be risk factors of fatal pulmonary embolism. Due to the low incidence of trapped embolus, it is not necessary to place filters in elderly patients and CDT-only patients.

CLINICAL IMPACT

The purpose of this paper is to standardize the use of inferior vena cava filter and avoid unnecessary filter implantation through the summary and analysis of a large number of clinical data. At the same time, more attention should be paid to and active treatment should be given to high-risk groups of pulmonary embolism.

Perioperative management of acetabular and pelvic fractures: evidence-based recommendations

PURPOSE

The American Academy of Orthopaedic Surgeons does not currently provide clinical practice guidelines for management of PAF. Accordingly, this article aims to review and consolidate the relevant historical and recent literature in important topics pertaining to perioperative management of PAF.

METHODS

A thorough literature review using PubMed, Cochrane and Embase databases was performed to assess preoperative, intraoperative and postoperative management of PAF fracture. Topics reviewed included: time from injury to definitive fixation, the role of inferior vena cava filters (IVCF), tranexamic acid (TXA) use, intraopoperative cell salvage, incisional negative pressure wound therapy (NPWT), intraoperative antibiotic powder use, heterotopic ossification prophylaxis, and pre- and postoperative venous thromboembolism (VTE) prophylaxis.

RESULTS

A total of 126 articles pertaining to the preoperative, intraoperative and postoperative management of PAF were reviewed. Articles reviewed by topic include 13 articles pertaining to time to fixation, 23 on IVCF use, 14 on VTE prophylaxis, 20 on TXA use, 10 on cell salvage, 10 on iNPWT 14 on intraoperative antibiotic powder and 20 on HO prophylaxis. An additional eight articles were reviewed to describe background information. Five articles provided information for two or more treatment modalities and were therefore included in multiple categories when tabulating the number of articles reviewed per topic.

CONCLUSION

The literature supports the use of radiation therapy for HO prophylaxis, early (< 5 days from injury) surgical intervention and the routine use of intraoperative TXA. The literature does not support the routine use of iNPWT or IVCF. There is inadequate information to make a recommendation regarding the use of cell salvage and wound infiltration with antibiotic powder. While the routine use of chemical VTE prophylaxis is recommended, there is insufficient evidence to recommend the optimal agent and duration of therapy.

Retrievable Inferior Vena Cava Filters-Use, Removal, and Removal Techniques

The use of retrievable inferior vena cava filters is on the rise, but there is an inadequate number of these filters being removed even if their use as a prophylactic for venous thromboembolism is no longer indicated. Complications with retrievable filters that remain in the patient for an extended duration include examples such as filter tilt and embedding into the caval wall. This raises concerns for whether the filter is properly functioning and for consequent sequelae, including recurrent thrombosis, stenosis, or inferior vena cava perforation. With these complications, there are also challenges to retrieving these filters via the standard techniques and thus more advanced techniques are required. Both standard and advanced techniques, their uses, and possible risks of these methods are also discussed.

Temporal trends in vena cava filter implantation in public health system inpatients: an 11-year analysis of the largest city in Brazil

Background

Vena cava filter implantation is considered a simple procedure, which can lead to overuse and over-indication. It is nevertheless associated with short and long-term complications.

Objectives

The goals of this study were to evaluate rates of vena cava filter implantation conducted by Brazil’s Unified Public Health System, analyzing in-hospital mortality and migration of patients from other cities seeking medical attention in São Paulo.

Methods

This study analyzed all vena cava filter procedures conducted from 2008 to 2018 in the city of São Paulo and registered on the public database using a big data system to conduct web scraping of publicly available databases.

Results

A total of 1324 vena cava filter implantations were analyzed. 60.5% of the patients were female; 61.7% were under 65 years old; 34.07% had registered addresses in other cities or states; and there was a 7.4% in-hospital mortality rate.

Conclusions

We observed an increase in the rates of use of vena cava filters up to 2010 and a decrease in rates from that year onwards, which coincides with the year that the Food and Drug Administration published a recommendation to better evaluate vena cava filter indications.

Variability in the perception and application of force used in IVC filter retrievals among interventional radiologists

INTRODUCTION

A long dwell time is associated with higher inferior vena cava (IVC) filter retrieval complication rates. Manufacturers advise that "excessive force should not be used" during filter retrieval; however, the term "excessive" is subjective and is likely to lead to variability amongst operators. The aims of this study were to 1) ascertain what interventional radiologists consider to be excessive force during filter retrieval and 2) to understand the variability in interventional radiologists' perception of force.

METHODS

The authors recruited interventional radiologists to perform a benchtop simulated filter retrieval. Participants were invited to pull on a modified force tester attached to a Gunther Tulip filter retrieval set (GTRS). The participants were asked to pull as if they were retrieving an IVC filter and stop when they felt it was clinically unsafe to apply greater force. They were then asked to replicate forces of 10N and 50N, respectively. Each of the three tasks was completed three times. Data were obtained on the clinical experience of the participants with specific questions focusing on their filter retrieval practices.

RESULTS

The range of maximum forces applied during filter retrieval varied between 0.8 and 79.8N. When asked to replicate 10N and 50N, for attempt-1, the median forces produced were 23.5N and 38.1N, respectively. A trend analysis showed that those who overestimate 10N are more likely to apply a greater overall maximum force (r_s = 0.622; P < 0.001).

CONCLUSION

There is wide variation in what interventional radiologists consider to be the maximum safe force to apply during IVC filter retrieval.

IMPLICATIONS FOR PRACTICE

Manufacturers and operators should consider methods in which only a safe range of forces can be applied during an IVC filter retrieval. Operators may wish to undertake 'personal' force calibration as part of training in interventional radiology.

Navigating inferior vena cava filters in invasive cardiology procedures: A systematic review

BACKGROUND

Transfemoral venous access (TFV) is the cornerstone of minimally invasive cardiac procedures. Although the presence of inferior vena cava filters (IVCFs) was considered a relative contraindication to TFV procedures, small experiences have suggested safety. We conducted a systematic review of the available literature on cardiac procedural success of TFV with IVCF in-situ.

METHODS

Two independent reviewers searched PubMed, EMBASE, SCOPUS, and Google Scholar from inception to October 2020 for studies that reported outcomes in patients with IVCFs undergoing TFV for invasive cardiac procedures. We investigated a primary outcome of acute procedural success and reviewed the pooled data for patient demographics, procedural complications, types of IVCF, IVCF dwell time, and procedural specifics.

RESULTS

Out of the 120 studies initially screened, 8 studies were used in the final analysis with a total of 100 patients who underwent 110 procedures. The most common IVCF was the Greenfield Filter (36%), 60% of patients were males and the mean age was 67.8 years. The overall pooled incidence of acute procedural success was 95.45% (95% confidence interval = 89.54-98.1) with no heterogeneity (I²  = 0%, p = 1) and there were no reported filter-related complications.

CONCLUSION

This systematic review is the largest study of its kind to demonstrate the safety and feasibility of TFV access in a variety of cardiac procedures in the presence of IVCF.

Non-retrieved inferior vena cava filters: causes and long-term follow-up

BACKGROUND

Temporary inferior vena cava (IVC) filters are not always retrieved. Information about long-term outcomes of patients with indwelling filters is scarce. Aims of our study were to assess reasons that preclude retrieval of temporary IVC filters and long-term outcomes and causes of death in patients with indwelling filters.

MATERIALS AND METHODS

Retrospective observational study including all consecutive patients undergoing IVC filter insertion from January 2009 through December 2018. Patients with permanent filters and those with temporary filters not retrieved were followed from insertion until June 2020.

RESULTS

We included 271 patients with a mean age of 63.8 years. The main indication for filter insertion was acute venous thromboembolism and contraindication for anticoagulation (83%). The filter was deemed as permanent in 24.4% of patients and temporary in 75.6%. Sixty six percent of temporary filters were retrieved; the main cause of non-retrieval was lack of planning / follow-up (57.9%). One hundred twelve patients (41.3%) remained with indwelling filters. After follow-up, 54.5% were alive and 45.5% had died, with a median survival time of 6.19 (95% CI, 2.63-9.75) years. The most frequent cause of death during follow-up was cancer (49%). The frequency of anticoagulant therapy was similar in both groups (57.4%% versus 54.9%).

CONCLUSIONS

The main preventable cause of non-retrieval of temporary IVC filters was lack of planning / follow-up. Structured follow-up programs should be implemented to increase retrieval rates. In patients with indwelling filters, the main cause of death was cancer and extended anticoagulation was not associated with survival.

Prevalence and Characterization of Interaction of Retrievable Inferior Vena Cava Filters with the Spine in Patients Undergoing Complex Filter Removal

PURPOSE

To examine spinal interaction types and prevalence of inferior vena cava (IVC) filters in patients presenting for complex filter removal.

MATERIALS AND METHODS

The records of 447 patients presenting for complex removal of IVC filters were reviewed, including patient demographics, IVC filter dwell time, filter fracture status, and computed tomography (CT) evidence of filter interaction with the spine. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disc. Patients with evidence of filter penetration and spinal interaction had abdominal CT that preceded filter removal assessed by 2 interventional radiologists to categorize the type of spinal interaction, including bony reaction and osteophyte formation.

RESULTS

CT evidence of spinal interaction by the filter was found in 18% of patients (80/447). Interaction with the spine was more common in single point of fixation filters than filters with rails (P = .007) and was more likely in filters with round wires than flat wires (P = .0007). Patients with interaction had longer dwell times (mean [SD] 5.7 [4.46] y) compared with patients without interaction (mean [SD] 3.2 [3.85] y); this relationship was significant (P < .0001). Women were more likely than men to experience filter/spine interaction (P = .04). Filters with spinal interaction were more likely to be fractured (P = .001). Filter interaction was found in 38% (30/78) of patients with symptoms, including chest and back pain, compared with 14% (50/369) of patients without symptoms (P < .0001, odds ratio 3.99).

CONCLUSIONS

Retrievable IVC filters may interact with the spine. These interactions are associated with longer filter dwell times, female sex, and round wire filter construction.

Inferior vena cava filter – comprehensive overview of current indications, techniques, complications and retrieval rates

Summary: Inferior vena cava (IVC) filter has been used to manage patients with pulmonary embolism and deep venous thrombosis. Its ease of use and the expansion of relative indications have led to a dramatic increase in IVC filter placement. However, IVC filters have been associated with a platitude of complications. Therefore, there exists a need to examine the current indications and identify the patient population at risk. In this paper, we comprehensively reviewed the current indications and techniques of IVC filter placement. Further, we examined the various complications associated with either permanent or retrievable IVC filters. Lastly, we examined the current data on filter retrieval.

Effectiveness of Inferior Vena Cava Filters in Patients With Stable and Unstable Pulmonary Embolism and Trends in Their Use

BACKGROUND

Trends in the use of inferior vena cava (IVC) filters in patients with pulmonary embolism (PE) who are stratified according to whether they are stable or unstable (in shock or ventilator dependent) may show where improvements of management could be made according to the best evidence that we now have.

METHODS

This was a retrospective cohort study based on administrative data, 1999-2014, from the National (Nationwide) Inpatient Sample.

RESULTS

In-hospital all-cause mortality in unstable patients who received an IVC filter was lower in each year of investigation and in all age groups. Mortality from 1999 to 2014 was 10,140 of 35,230 (28.8%) with an IVC filter compared with 54,018 of 116,642 (46.3%) without a filter (P <0.0001). In stable patients from 1999 to 2014, mortality with an IVC filter was 31,909 of 546,858 (5.8%) with an IVC filter compared with 220,443 of 3,367,783 (6.5%) without a filter (P <0.0001). In patients ages > 80 years, mortality in stable patients with an IVC filter was 7,438 of 114,457 (6.5%) with an IVC filter compared with 64,113 of 567,348 (11.3%) without an IVC filter (P <0.0001). The number of stable patients who received an IVC filter decreased from 2010 to 2014, but even in those years the largest number of IVC filters was inserted in stable patients, 194,502 of 212,611 (91.5%).

CONCLUSIONS

Mortality is markedly reduced in unstable patients who receive an IVC filter. Despite this, the proportion of unstable patients who receive an IVC filter is decreasing. The largest number of IVC filters continues to be inserted in stable patients, although there is no evidence of a clinically meaningful reduced mortality with IVC filters in stable patients unless age >80 years.

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.

Vena Cava Filters and In-Hospital Case Fatality Among Patients With Pulmonary Embolism: Results From a Large Population-Based Study

In patients with venous thromboembolism (VTE), vena cava filters (VCFs) are currently only recommended when anticoagulant treatment is contraindicated or if VTE has recurred despite adequate anticoagulation. However, evidence on the efficacy of filter in patients with VTE is not compelling. We evaluated potential efficacy of VCF in reducing in-hospital mortality in a large population of patients presenting with a first episode of pulmonary embolism (PE). Patients were collected using regional hospital-discharge databases covering a population of more than 13 million of inhabitants in Northern Italy. For each year of observation, we calculated the proportion of cases with VCF among all PE incident cases. The temporal trend of VCF application during the study period was also derived. The effect of VCF use on in-hospital case-fatality rate was evaluated with a multivariate regression model and with the use of propensity score matching. During the study period (2002-2012), 60 813 patients were hospitalized for a first episode of acute PE. In-hospital case-fatality rate for PE was 13.3%. Vena cava filters were used in 745 (1.22%) patients. The annual use of VCF remained stable from 2002 to 2008, while it progressively decreased afterward. After adjustment for available confounders, case-fatality rate remained significantly lower in patients who received VCF compared to the one registered in patients who did not (odds ratio [OR] 0.46; 95% confidence interval [CI]: 0.34-0.62). Propensity score matching gave similar results (OR: 0.42; 95% CI: 0.30-0.61). Vena cava filters were infrequently used in patients with acute PE. Insertion of VCF appeared to sensibly reduce all-cause in-hospital mortality in this subgroup of patients.

Continuing Use of Inferior Vena Cava Filters Despite Data and Recommendations Against Their Use in Patients With Deep Venous Thrombosis

The purpose of the present investigation is to determine the response to the evidence and recommendations against the use of inferior vena cava (IVC) filters in patients with deep venous thrombosis (DVT). This was a retrospective cohort study based on administrative data from the National Hospital Discharge Survey 1979 to 2006 and from the National (Nationwide) Inpatient Sample 2007 to 2014. The number of IVC filters inserted in patients with lone DVT peaked in 2009 and then decreased from 2009 to 2014. The proportion of patients with lone DVT who received an IVC filter peaked in 2010 and then decreased from 2010 to 2014. Both the number of IVC filters inserted yearly and the proportion of patients who received an IVC filter remained higher than in 1998 when a randomized controlled trial showed no reduced mortality with permanent IVC filters in patients with DVT. In conclusion, large numbers of patients with lone DVT continue to receive IVC filters despite a randomized controlled trial that showed no reduced mortality with IVC filters in patients with DVT and despite clinical guideline recommendations against the use of IVC filters in such patients.

Asymptomatic patients with unsuccessful percutaneous inferior vena cava filter retrieval rarely develop complications despite strut penetrations through the caval wall

OBJECTIVE

We established a program for retrieval of inferior vena cava (IVC) filters within our hospital system. When percutaneous retrieval fails, we only recommend open surgical removal for symptoms and other complications. We examined our outcomes with conservative management of unsuccessful percutaneous retrieval and open surgical removal for symptomatic/complicated IVC filters.

METHODS

All patients with history of IVC filter placement who were referred to us for retrieval between 2010 and 2016 were evaluated. Before retrieval, patients were evaluated for risk of future venous thromboembolic events and ongoing need for IVC filtration. Asymptomatic patients with unsuccessful percutaneous filter retrieval were recommended to have annual follow-up with plain abdominal radiographs and to take daily low-dose aspirin. Patients with symptoms referable to the indwelling filter and those with complications were offered open surgical removal.

RESULTS

There were 213 patients with a history of IVC filter placement who underwent 220 percutaneous attempts for retrieving 214 IVC filters (four patients had two attempts, one patient had three attempts). Technical success in percutaneously retrieving the filter was 180 of 214 (84.1%) at a median of 5.5 months (interquartile range [IQR], 3.5-9.2) from implant. The median filter dwell time was significantly longer in unsuccessful compared with successful retrieval attempts (8.3 months [IQR, 4.3-15.1 months] vs 5.5 months [IQR, 3.2-8.7 months]; P = .011). Of the 34 filters in 33 patients that could not be retrieved percutaneously, all had either significant filter barb penetration through the caval wall or a tilt angle of greater than 15°. The majority of patients (67%) remained asymptomatic without any further complications over a mean follow-up of 24 months (IQR, 12-50 months). No asymptomatic patients developed symptoms or complications over the follow-up period. Two of the five patients who were symptomatic underwent open surgical removal via minilaparotomy. An additional six patients who failed percutaneous retrieval at other institutions were referred to us for open surgical removal owing to symptoms or complications. Technical success for all open surgical removal of IVC filters was 100%. All patients had resolution of their symptoms after percutaneous or open surgical removal.

CONCLUSIONS

Asymptomatic patients with unsuccessful percutaneous IVC filter retrieval seem to have low complications in midterm follow-up despite significant filter strut penetration. Without symptoms or other complications, such patients do not require referral for open surgical filter removal. Symptomatic patients can expect low morbidity and resolution of symptoms after percutaneous or open surgical removal. Further studies are needed to determine the cost-effectiveness of routinely removing asymptomatic IVC filters.

Between a Clot and a Scarred Place

Immobilized orthopedic trauma patients face an elevated risk of venous thromboembolism (VTE). We present a case in which a patient undergoing staged repair of traumatic orthopedic injuries developed deep venous thrombosis (DVT) during hospitalization, prior to repair of a lower extremity injury for which delay in operation might result in poor functional outcome. We provide an overview of recommendations regarding pharmacologic prophylaxis of VTE in orthopedic patients. We review the importance of cultivating a high index of suspicion for VTE in such patients, even when receiving appropriate prophylaxis and lacking overt symptoms. Finally, we outline the multidisciplinary decision-making process regarding optimizing care for the patient in a precarious position of developing acute VTE while awaiting urgent surgery. Specifically, we review the safety, efficacy, and management of retrievable inferior vena cava filters (rIVCF) for this population.

Long-Term Clinical Outcomes of Complicated Retrievable Inferior Vena Cava Filter for Deep Venous Thrombosis Patients: Safety and Effectiveness

Background

Inferior vena cava (IVC) filters have proven valuable for the prevention of pulmonary embolism. However, retrieval of IVC filters can be challenging and complicated techniques are needed. The aim of this study was to retrospectively review the outcomes after retrieval of retrievable IVC filters which required complicated retrieval techniques.

Material/Methods

This study was a single-center retrospective observational study. All patients who underwent complicated IVC filter retrieval from September 2012 to May 2016 were included. Patient demographics and filter retrieval procedure were documented. Clinical outcomes and procedure-related complications were evaluated. Villalta score and VEINES-QOL/Sym were recorded to assess post-thrombotic syndrome.

Results

A total of 79 consecutive patients, 37 males and 42 were female, with a mean age of 46.5 years (age range: 22–65 years) were included in this study. IVC filters, with mean indwell time of 108 days (range: 74–157 days), were refractory to standard treatment and underwent complicated IVC filter retrieval. There were 6 serious procedure-related complications: 4 popliteal puncture area hematoma complications and 2 hematuria complications. With a mean follow-up of 20.5 months (range: 18–24 months), no pulmonary embolisms occurred, and 2 patients experienced recurrent deep venous thrombosis. Twenty-seven patients developed post-thrombotic syndrome within the first 2 years after IVC retrieval.

Conclusions

Complicated methods can be used to safely remove IVC filters, alleviate filter-related morbidity, and reduce risk for post-thrombotic syndrome. The application of these techniques was safe and effective for patients with refractory IVC filters.

Multi loop snare technique for difficult inferior vena cava filter retrievals

Introduction

Use of optional vena cava filters has steadily increased. In the majority of cases removal is successful using standard techniques. In cases of tilting and migration of the filter however, more advanced techniques are necessary. The "loop-snare" technique has been described for such cases. Difficulties arise when the loop starts to slip around the legs and arms of the filter.

New technique

We present an improved loop-snare technique which allows to retrieve IVC filters when the simple loop-snare technique fails. We used additional loops, in one case one additional loop in another case two additional loops around the filter tip which allowed successful retrieval. The additional loops were created with a reversed shaped catheter. All guidewires were then engaged with a snare and pulled into a large sheath. The additional loops stabilize the tip and the filter can be pulled into the sheath.

Conclusion

The "multiple-loop-snare" technique is a refinement of the previously described "single loop-snare" technique and can be used when one loop fails.

Persistently low inferior vena cava filter retrieval rates in a population-based cohort

BACKGROUND

Practice patterns associated with inferior vena cava (IVC) filter placement have seen considerable variation in the last decade. We used a statewide administrative database to examine trends in IVC filter placement and retrieval in the general population.

METHODS

We reviewed Florida state inpatient and ambulatory surgery databases from 2004 to 2014. International Classification of Diseases, Ninth Revision diagnosis and procedure codes and Current Procedural Terminology codes were searched for patients undergoing inpatient or outpatient IVC filter placement, and each patient was longitudinally tracked to the time of inpatient or outpatient filter retrieval. For inpatient filter placements, associated diagnoses were reviewed to identify indications for placement. Univariate and multivariate logistic regression models were constructed to identify factors associated with improved retrieval rates.

RESULTS

During the 11-year period, 131,791 IVC filter placements were identified, with a 50% increase from 2004 to 2010 and a 24% decline from 2010 to 2014. Median age at filter placement was 71 years (interquartile range, 57-81 years). Mean follow-up after filter placement was 17.3 ± 25.5 months. Only 8637 filters (6.6%) were retrieved. The annual retrieval rate trended upward, from 3.4% in 2004 to 8.5% in 2013 (P < .001). Median filter dwell time was 96.5 days (interquartile range, 44-178 days). Diagnoses associated with filter placement included venous thromboembolism (75.9%), trauma (35.0%), hemorrhage (29.9%), malignant disease (29.4%), and stroke (5.1%). Retrieval rates were highest in younger patients (34.0% in patients younger than 20 years) and lowest in Medicare patients (2.5%). In a multivariate logistic regression model, Medicare was associated with decreased retrieval rates (odds ratio, 0.33; 95% confidence interval, 0.31-0.35; P < .001) after adjusting for age and associated diagnoses. Weaker risk factors included increased age, white race, and diagnoses of deep venous thrombosis, pulmonary embolism, and malignant disease. A trauma diagnosis was associated with improved retrieval. To further investigate the Medicare effect, a propensity score-matched model was created to better account for confounding effects. In this model, Medicare persisted as a risk factor for decreased filter retrieval (odds ratio, 0.43; 95% confidence interval, 0.40-0.46; P < .001).

CONCLUSIONS

IVC filter placements, after a substantial increase between 2004 and 2010, have been declining since 2010. Retrieval rates in the general population are steadily improving but continue to lag behind those described in center-specific literature. Increased age and Medicare as the primary payer are the strongest risk factors for lack of filter retrieval. Widespread improvements on a national scale are needed to improve the appropriateness of filter placements and to enhance filter retrieval rates.

Multicenter investigation of the incidence of inferior vena cava filter fracture

PURPOSE

Inferior vena cava filter fracture (FF) may cause life-threatening complications, including cardiac tamponade, although the actual prevalence remains unclear. Therefore, we investigated the incidence of FF.

MATERIALS AND METHODS

Data on fracture incidence with filter brands, filter positions [suprarenal (SR) vs. infrarenal (IR)], and follow-up durations were collected from the databases of eight hospitals.

RESULTS

Of 532 patients, Günther Tulip (GT), Trap/OptEase (TE/OE), ALN and VenaTech (VT) were implanted in 345, 147, 38 and 2 patients, respectively. Of these, filter retrieval was attempted in 110 (21.7%) patients and was successful in 106 (96.4%). Of the remaining 426 patients, FFs were observed in two (0.7%) of 270 GT filters and 19 (14.1%) of 135 TE/OE filters. Fragment embolization occurred in one patient with a GT filter (50.0%) and three with a TE/OE filter (15.8%) with a total follow-up interval of 718.0 ± 1019.4 days. FF occurred more frequently in TE/OE than in GT filters (p < 0.001). Kaplan-Meier estimates showed significantly higher fracture-free rates for GT than TE/OE (p < 0.001) and IR-TE/OE than SR-TE/OE (p < 0.05).

CONCLUSIONS

TE/OE filters are not suitable for permanent implantation due to the relatively early and high fracture rates.

Endobronchial Forceps-Assisted and Excimer Laser-Assisted Inferior Vena Cava Filter Removal: The Data, Where We Are, and How It Is Done

The recognition of inferior vena cava filter related complications has motivated increased attentiveness in clinical follow-up of patients with inferior vena cava filters and has led to development of multiple approaches for retrieving filters that are challenging or impossible to remove using conventional techniques. Endobronchial forceps and excimer lasers are tools for designed to aid in complex inferior vena cava filter removals. This article discusses endobronchial forceps-assisted and excimer laser-assisted inferior vena cava filter retrievals.

Hospitalization metrics associated with hospital-level variation in inferior vena cava filter utilization for patients with venous thromboembolism in the United States: Implications for quality of care

Variation in the use of inferior vena cava filters (IVCFs) across hospitals has been observed, suggesting differences in quality of care. Hospitalization metrics associated with venous thromboembolism (VTE) patients have not been compared based on IVCF utilization rates using a national sample. We conducted a descriptive retrospective study using the Nationwide Readmissions Database (NRD) to delineate the variability of hospitalization metrics across the hospital quartiles of IVCF utilization for VTE patients. The NRD included all-payer administrative inpatient records drawn from 22 states. Adult (≥ 18 years) patients with VTE hospitalizations with or without IVCF were identified from January 1, 2013 through December 31, 2014 and hospitals were divided into quartiles based on the IVCF utilization rate as a proportion of VTE patients. Primary outcome measures were observed rates of in-hospital mortality, 30-day all-cause readmissions and VTE-related readmissions, cost, and length of stay. Patient case-mix characteristics and hospital-level factors by hospital quartiles of IVCF utilization rates, were compared. Overall, 12.29% of VTE patients had IVCF placement, with IVCF utilization ranging from 0% to 46.84%. The highest quartile had fewer pulmonary embolism patients relative to deep vein thrombosis patients, and older patient ages were present in higher quartiles. The highest quartile of hospitals placing IVCFs were more often private, for-profit, and non-teaching. Patient and hospital characteristics and hospitalization metrics varied by IVCF utilization rates, but hospitalization outcomes for non-IVCF patients varied most between quartiles. Future work investigating the implications of IVCF utilization rates as a measure of quality of care for VTE patients is needed.

Trends in vena cava filter insertions and "prophylactic" use

BACKGROUND

Prophylactic vena cava filter (VCF) use in patients without venous thromboembolism is common practice despite ongoing controversy. Thorough analysis of the evolution of this practice is lacking. We describe trends in VCF use and identify events associated with changes in practice.

METHODS

Using the National Inpatient Sample, we conducted a retrospective observational study of U.S. adult hospitalizations from 2000 to 2014. Trends in prophylactic VCF insertion were analyzed both across the entire study population and within subgroups according to trauma status and type of concurrent surgery. Annual percentage change (APC) was calculated, and trends were analyzed using Poisson regression.

RESULTS

Among 461,904,314 adult inpatients (median [interquartile range] age, 58.1 [38.5-74.3] years; 39.6% male), the incidence of VCF insertion increased rapidly at first (from 0.19% to 0.35%; APC, 11.2%; 95% confidence interval [CI], 10.3%-12.2%; P < .001), then at a slower rate after the publication of the Prévention du Risque d'Embolie Pulmonaire par Interruption Cave 2 (PREPIC2) trial in 2005 (from 0.35% to 0.42%; APC, 4.4%; 95% CI, 2.8%-6.0%; P < .001), and it began decreasing after the 2010 Food and Drug Administration (FDA) safety alert (from 0.42% to 0.32%; APC, -5.5%; 95% CI, -6.5% to -4.6%; P < .001). The percentage of total VCFs that had a prophylactic indication increased quickly before publication of the PREPIC2 trial (APC, 19.5%; 95% CI, 17.9%-21.0%; P < .001), increased at a slower rate after publication in 2005 (APC, 4.4%; 95% CI, 2.6%-6.2%; P < .001), and dropped after the FDA safety alert, stabilizing at 18.5% for the last 3 years (APC, -0.3%; 95% CI, -2.2% to 1.7%; P = .8). Subgroups most associated with prophylactic VCF insertion were operative trauma (odds ratio [OR], 10.9; 95% CI, 10.2-11.7), orthopedic surgery (OR, 4.7; 95% CI, 4.3-5.2), and neurosurgical procedures (OR, 3.9; 95% CI, 3.6-4.2). All groups except orthopedic surgery experienced a deceleration in prophylactic VCF growth after the publication of PREPIC2. Meanwhile, the FDA safety alert was associated with a decrease in prophylactic VCF insertions for all groups except other major surgery.

CONCLUSIONS

Whereas publication of the PREPIC2 trial led to a deceleration in prophylactic VCF insertion growth, the FDA alert had a bigger impact, leading to declining rates of prophylactic VCF use. Further investigations of prophylactic insertion of VCF in trauma, orthopedic, and neurosurgical patients are needed to determine whether current levels of use are justified.

Retrospective analysis of outcomes following inferior vena cava (IVC) filter placement in a managed care population

The role of inferior vena cava filter (IVC) filters for prevention of pulmonary embolism (PE) is controversial. This study evaluated outcomes of IVC filter placement in a managed care population. This retrospective cohort study evaluated data for individuals with Humana healthcare coverage 2013-2014. The study population included 435 recipients of prophylactic IVC filters, 4376 recipients of therapeutic filters, and two control groups, each matched to filter recipients. Patients were followed for up to 2 years. Post-index anticoagulant use, mortality, filter removal, device-related complications, and all-cause utilization. Adjusted regression analyses showed a positive association between filter placement and anticoagulant use at 3 months: odds ratio (ORs) 3.403 (95% CI 1.912-6.059), prophylactic; OR, 1.356 (95% CI 1.164-1.58), therapeutic. Filters were removed in 15.67% of prophylactic and 5.69% of therapeutic filter cases. Complication rates were higher with prophylactic procedures than with therapeutic procedures and typically exceeded 2% in the prophylactic group. Each form of filter placement was associated with increases in all-cause hospitalization (regression coefficient 0.295 [95% CI 0.093-0.498], prophylactic; 0.673 [95% CI 0.547-0.798], therapeutic) and readmissions (OR 2.444 [95% CI 1.298-4.602], prophylactic; 2.074 [95% CI 1.644-2.616], therapeutic). IVC filter placement in this managed care population was associated with increased use of anticoagulants and greater healthcare utilization compared to controls, low rates of retrieval, and notable rates of device-related complications, with effects especially pronounced in assessments of prophylactic filters. These findings underscore the need for appropriate use of IVC filters.

Retrievable inferior vena cava filter utilization in obstetric patients

Objectives: The objective of this study is to evaluate patterns of use and outcomes of retrievable inferior vena cava filters (rIVCF) in obstetric patients. Methods: A single center review of consecutive patients who underwent rIVCF placement during pregnancy/postpartum in 2005-2016. A pooled analysis of the relevant cases in the English literature was conducted. Results: The current cohort comprised 24 women, median age 27 [interquartile range 24-30] years. Among 10 filters placed during pregnancy, the most common indication (n = 4) was the need to withhold anticoagulation therapy before delivery, in the presence of acute thrombosis. In the postpartum period, most filters (64%, 9/14) were an adjunct to catheter-directed thrombolytic therapy. Inferior vena cava filters (IVCF)-related complications occurred in seven (29.2%). Retrieval was attempted in 21 patients (87.5%), and was technically successful in 19 (90.5%), for an overall removal rate of 79.1%. Pooled analysis of the literature (n = 98) showed comparable rates for filter removal and complications (81.6%, p = .78 and 24.2%, p = .60, respectively). Suprarenal placement (p = .12) and elective cesarean section (p = .19) did not reduce overall complication and retrieval rates. The estimated radiation dose among pregnant patients who underwent rIVCF placement without adjunct catheter directed thrombolysis (CDT) (mean 695 Gy cm²) was significantly lower than the radiation dose used in postpartum patients (1863 Gy cm²) or in pregnant patients in whom adjunct CDT was utilized (4059 Gy cm²) (p = .001 for both comparisons). Conclusions: Frequent rIVCF-related complications, radiation exposure, and removal failure call for their cautious utilization in obstetric patients. The role of suprarenal placement and elective cesarean section to improve outcomes has yet to be established.

Osteodiskitis of Lumbar Spine Due to Migrated Fractured Inferior Vena Cava Filter

BACKGROUND

Venous thromboembolism can be a significant cause of morbidity in the trauma population. Medical and surgical specialties have been pushing the indication for prophylactic filter placement.

CASE DESCRIPTION

A 36-year-old man presented with axial lower back pain with a radicular right L2 component after lifting a heavy object. He had a history of penetrating brain trauma 3 years prior, with placement of a prophylactic inferior vena cava filter. His radiograph, computed tomography, and magnetic resonance imaging of the lumbar spine showed fracture of his filter, with migration of the fractured fragment through the inferior vena cava and into the L2-L3 disk space, and surrounding bony lysis and severe osteodiskitis. He was treated medically with intravenous and then oral antibiotics and improved clinically and radiographically.

CONCLUSIONS

Conservative use of filter devices and early retrieval once their indication expires are paramount to avoid unnecessary complications.

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.

Are too many inferior vena cava filters used? Controversial evidences in different clinical settings: a narrative review

The use of inferior vena cava filters to prevent pulmonary embolism is increasing mainly because of indications that appear to be unclearly codified and recommended. The evidence supporting this approach is often heterogeneous, and mainly based on observational studies and consensus opinions, while the insertion of an IVC filter exposes patients to the risk of complications and increases health care costs. Thus, several proposed indications for an IVC filter placement remain controversial. We attempt to review the proof on the efficacy and safety of IVC filters in several "special" clinical settings, and assess the robustness of the available evidence for any specific indication to place an IVC filter.

Prophylactic inferior vena cava filters in patients with fractures of the pelvis or long bones

BACKGROUND

Which patients with fractures, if any, have a lower mortality with prophylactic inferior vena cava filters has yet to be established. The purpose of this investigation is to determine if patients with low-risk fractures might benefit from a prophylactic inferior vena cava filter.

METHODS

Administrative data was analyzed from the National (Nationwide) Inpatient Sample using ICD-9-CM codes. Included patients were aged 18 years or older with a primary diagnosis of non-complex fracture of the pelvis, or fracture of the femuralone, or fracture of the tibia and/or fibula.

RESULTS

From 2003-2012, 1,479,039 patients were hospitalized with low-risk fracture. The vast majority of patients with fracture, 1,461,378 of 1,479,039 (98.8%) did not receive an inferior vena cava filter. Among those who did not receive a filter, 1,446,489 of 1,461,378 (99.0%) did not develop deep venous thrombosis or pulmonary embolism. Pulmonary embolism without a filter occurred in 7207 of 1,461,378 (0.5%) and deep venous thrombosis occurred in 7682 of 1,461,378 (0.5%). Total in-hospital all-cause mortality in those who did not receive a filter was 15,683 of 1,461,378 (1.1%). An inferior vena cava filter was inserted in 17,661 of 1,479,039 (1.2%) of patients with fractures. Most of those who received an inferior vena cava filter, 12,025 of 17,661 (68.1%) did not develop pulmonary embolism or deep venous thrombosis. Total in-hospital all-cause mortality in all patients with an inferior vena cava filter was 516 of 17,661 (2.9%).

CONCLUSION

The evidence is against the use of a prophylactic inferior cava vena filter in patients with a non-complex pelvic fracture or single fracture of the femur or fracture of the tibia and/or fibula.

Factors associated with reduced radiation exposure, cost, and technical difficulty of inferior vena cava filter placement and retrieval

We sought to delineate factors of inferior vena cava filter placement associated with increased radiation and cost and difficult subsequent retrieval. In total, 299 procedures from August 2013 to December 2014, 252 in a fluoroscopy suite (FS) and 47 in the operating room (OR), were reviewed for radiation exposure, fluoroscopy time, filter type, and angulation. The number of retrieval devices and fluoroscopy time needed for retrieval were assessed. Multiple linear regression assessed the impact of filter type, procedure location, and patient and procedural variables on radiation dose, fluoroscopy time, and filter angulation. Logistic regression assessed the impact of filter angulation, type, and filtration duration on retrieval difficulty. Access site and filter type had no impact on radiation exposure. However, placement in the OR, compared to the FS, entailed more radiation (156.3 vs 71.4 mGy; P = 0.001), fluoroscopy time (6.1 vs 2.8 min; P < 0.001), and filter angulation (4.8° vs 2.6°; P < 0.001). Angulation was primarily dependent on filter type (P = 0.02), with VenaTech and Denali filters associated with decreased angulation (2.2°, 2.4°) and Option filters associated with greater angulation (4.2°). Filter angulation, but not filter type or filtration duration, predicted cases requiring >1 retrieval device (P < 0.001) and >30 min fluoroscopy time (P = 0.02). Cost savings for placement in the FS vs OR were estimated at $444.50 per case. In conclusion, increased radiation and cost were associated with placement in the OR. Filter angulation independently predicted difficult filter retrieval; angulation was determined by filter type. Performing filter placement in the FS using specific filters may reduce radiation and cost while enabling future retrieval.

Inferior vena cava filter use and patient safety: legacy or science?

There has been a dramatic increase in vena cava filter (VCF) use over the past 20 years in the absence of evidence that filters provide a net patient benefit or are required in most cases. This increase is largely attributable to the availability of retrievable filters and expanded indications, particularly as primary prophylaxis in patients thought to be at high risk of pulmonary embolism. Substantial variability in VCF use, unrelated to patient clinical factors, has been shown between hospitals, from region to region, and among various countries. Despite the lack of direct evidence for the benefit of VCFs for any indication, it is appropriate to insert a retrievable VCF in patients with a recent proximal deep vein thrombosis and an absolute contraindication to therapeutic anticoagulation and then to remove the filter once the bleeding risk decreases and the patient has been anticoagulated. Unfortunately, a high proportion of retrievable filters are not removed, even after the reason for their placement has long passed. Retrievable filters are associated with substantial rates of complications if they are not removed, including penetration of the vena caval wall, fracture and embolization of filter fragments, and caval occlusion. Patient safety priorities and medical-legal concerns mandate careful selection of patients for VCF placement and removal shortly after anticoagulation has been initiated.

Medical literature, vena cava filters and evidence of efficacy

Up to 15% of all patients with venous thromboembolism (VTE) receive an inferior vena cava filter, and prophylactic placements are increasing. To determine whether current use of filters is based on robust evidence, a global review of the recent (2001–2012) literature on filters was undertaken. The MEDLINE database was searched for articles related to filters appearing during the period 2001–2012, updating a prior search of literature from 1975–2001. All retrieved articles were analysed, classified into predetermined categories and compared to the prior analysis; randomised and large (>100 patients with a filter) comparative non-randomised clinical studies were read in full. The 651 articles, vs 568 in the period 1975–2000, consisted mainly of retrospective series (37.8%), case reports (31.7%), reviews (14.7%, vs 6.7%, p<0.001), animal and/or in vitro studies (7.5%, vs 12.9%, p=0.002), and prospective series or trials (4.9%, vs 7.4%, p=0.07). Of 4 new randomised trials (RCT), none were designed to test the efficacy of the device; to date, only one RCT has attempted to ascertain efficacy, occurring during the period 1975–2000. Eleven large non-randomised studies compared clinical outcomes of patients with and without filters, in VTE patients (n=5) or prophylactic indications (n=6); two studies found statistically significant relationships between filter use and lower mortality rates, though none could demonstrate a causal relationship. Hence, the plethoric literature on filters parallels growing experience with these devices, but still fails to provide reliable evidence that filter use improves relevant clinical outcomes. No indication for filter placement is based on appropriate scientific evidence.

Interventional Treatment of Pulmonary Embolism

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

Complications and Retrieval Data of Vena Cava Filters Based on Specific Infrarenal Location

PURPOSE

Although recommended placement of IVC filters is with their tips positioned at the level of the renal vein inflow, in practice, adherence is limited due to clinical situation or IVC anatomy. We seek to evaluate the indwelling and retrieval complications of IVC filters based on their specific position within the infrarenal IVC.

MATERIALS AND METHODS

Retrospective, single institution study of 333 consecutive infrarenal vena cava filters placed by interventional radiologists in patients with an average age of 62.2 ± 15.7 years was performed between 2013 and 2015. Primary indication was venous thromboembolic disease (n = 320, 96.1%). Filters were classified based on location of the apex below the lowest renal vein inflow on the procedural venogram: less than 1 cm (n = 180, 54.1%), 1-2 cm (n = 96, 28.8%), and greater than 2 cm (n = 57, 17.1%). Denali (n = 171, 51.4%) and Celect (n = 162, 48.6%) filters were evaluated. CT follow-up, indwelling complications, and retrieval data were obtained.

RESULTS

Follow-up CT imaging performed for symptomatic indications occurred for 38.3% of filters placed < 1 cm below the lowest renal vein, 27.1% of filters placed 1-2 cm, and 36.8% placed > 2 cm (p = .16). There was no difference in caval strut penetration, penetration of adjacent viscera, time to penetration, filter migration, or tilt (p = .15, .27, .41, .57, .93). No filter fractures occurred. There was no difference in the incidence of breakthrough PE or complex filter retrieval (p = .83, .59). Only one retrieval failure occurred.

CONCLUSIONS

This study suggests filter apex location within the infrarenal IVC, including placement > 2 cm below the level of the renal vein inflow, is not associated with differences in indwelling or retrieval complications.

LEVEL OF EVIDENCE

Level 3 non-randomized controlled follow-up study.

Inferior Vena Cava Filters to Prevent Pulmonary Embolism: Systematic Review and Meta-Analysis

BACKGROUND

Inferior vena cava (IVC) filters are widely used for prevention of pulmonary embolism (PE). However, uncertainty persists about their efficacy and safety.

OBJECTIVES

The authors conducted a systematic review and meta-analysis of the published reports on the efficacy and safety of IVC filters.

METHODS

The authors searched PubMed, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov through October 3, 2016, for randomized controlled trials (RCTs) or prospective controlled observational studies of IVC filters versus none in patients at risk of PE. Inverse variance fixed-effects models with odds ratio (OR) as the effect measure were used for primary analyses. Main outcomes included subsequent PE, PE-related mortality, all-cause mortality, and subsequent deep vein thrombosis (DVT).

RESULTS

The authors' search retrieved 1,986 studies, of which 11 met criteria for inclusion (6 RCTs and 5 prospective observational studies). Quality of evidence for RCTs was low to moderate. Overall, patients receiving IVC filters had lower risk for subsequent PE (OR: 0.50; 95% confidence interval [CI]: 0.33 to 0.75); increased risk for DVT (OR: 1.70; 95% CI: 1.17 to 2.48); nonsignificantly lower PE-related mortality (OR: 0.51; 95% CI: 0.25 to 1.05); and no change in all-cause mortality (OR: 0.91; 95% CI: 0.70 to 1.19). Limiting the results to RCTs showed similar results. Findings were substantively similar across a wide range of sensitivity analyses.

CONCLUSIONS

Very few prospective controlled studies, with limited quality of evidence, exist regarding the efficacy and safety of IVC filters. Overall, filters appear to reduce the risk of subsequent PE, increase the risk for DVT, and have no significant effect on overall mortality.

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.