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Importance: Inferior vena cava filters are commonly implanted and infrequently retrieved. Nonretrieval contributes to significant morbidity, motivating US Food and Drug Administration and multisociety communications emphasizing the need for improved device surveillance. Current guidelines suggest that implanting physicians and referring physicians should be responsible for device follow-up, but it is not known whether shared responsibility contributes to lower retrieval., Objective: To determine if primary responsibility for follow-up care assumed by the implanting physician team is associated with increased device retrieval., Design, Setting, and Participants: This retrospective cohort study examined a prospectively collected registry of patients with inferior vena cava filters implanted from June 2011 to September 2019. Medical record review and data analysis was completed in 2021. The study included 699 patients who underwent implantation of retrievable inferior vena cava filters at an academic quaternary care center., Exposures: Prior to 2016, implanting physicians had a passive surveillance strategy whereby letters highlighting indications for and the need for timely retrieval were mailed to patients and ordering clinicians. Starting in 2016, implanting physicians assumed active responsibility for surveillance, whereby candidacy for device retrieval was assessed periodically via phone calls and retrieval scheduled when appropriate., Main Outcomes and Measures: The main outcome was the odds of inferior vena cava filter nonretrieval. Within regression modeling of the association between the surveillance method and nonretrieval, additional covariates of patient demographics, concomitant malignant neoplasm, and presence of thromboembolic disease were included., Results: Of the 699 patients who received retrievable filter implants, 386 (55.2%) were followed up with passive surveillance, 313 (44.8%) with active surveillance, 346 (49.5%) were female, 100 (14.3%) were Black individuals, and 502 (71.8%) were White individuals. The mean (SD) age at filter implantation was 57.1 (16.0) years. Mean (SD) yearly filter retrieval increased following the adoption of active surveillance, from 190 of 386 (48.7%) to 192 of 313 (61.3%) (P < .001). Fewer filters were deemed permanent in the active group vs passive group (5 of 313 [1.6%] vs 47 of 386 [12.2%]; P < .001). Age at the time of implantation (OR, 1.02; 95% CI, 1.01-1.03), concomitant malignant neoplasm (OR, 2.18; 95% CI, 1.47-3.24), and passive contact method (OR, 1.70; 95% CI, 1.18-2.47) were associated with increased odds of filter nonretrieval., Conclusions and Relevance: The findings of this cohort study suggest that active surveillance by implanting physicians is associated with improved inferior vena cava filter retrieval. These findings support encouraging physicians who implant the filter to take primary responsibility for tracking and retrieval.

Importance: Despite historically high rates of use, most inferior vena cava (IVC) filters are not retrieved. The US Food and Drug Administration safety communications recommended retrieval when the IVC filter is no longer indicated out of concern for filter-related complications. However, failure rates are high when using standard techniques for retrieval of long-dwelling filters, and until recently, there have been no devices approved for retrieval of embedded IVC filters., Objective: To evaluate the safety and success of excimer laser sheath-assisted retrieval of embedded IVC filters., Design, Setting, and Participants: A retrospective, multicenter, clinical cohort study of excimer laser sheath-assisted IVC filter retrievals from 7 US sites was conducted between March 1, 2012, and February 28, 2021, among 265 patients who underwent IVC filter retrieval using the laser. Patients were substratified between a high-volume single center and a multicenter data set. A blinded physician committee adjudicated reported complications and their association with use of the laser., Exposures: Retrieval of IVC filters using excimer laser sheath., Main Outcomes and Measures: The primary safety end point was device-related major complication rate (Society of Interventional Radiology categories C to F, which included any adverse event associated with morbidity or disability that increases the level of care, results in hospital admission, or substantially lengthens the hospital stay). The primary success end point was technical success of IVC filter retrieval. The primary end points were compared with literature-derived, meta-analysis-suggested target performance goals., Results: The single-center experience included 139 participants (mean [SD] age, 52 [16] years; 78 female participants [56.1%]), and the multicenter experience included 126 participants (mean [SD] age, 52 [16] years; 75 female participants [59.5%]). The device-related major complication rate was 2.9% (4 of 139; 95% CI, 0.8%-7.2%; P = .001) for the single-center experience and 4.0% (5 of 126; 95% CI, 1.3%-9.0%; P = .01) for the multicenter experience, both of which were significantly lower than the primary safety performance goal (10%). No major complications were considered to be definitively associated with use of the laser. The technical success rate was 95.7% (133 of 139; 95% CI, 90.8%-98.4%; P = .007) for the single-center experience and 95.2% (120 of 126; 95% CI, 89.9%-98.2%; P = .02) for the multicenter experience, both of which were significantly higher than the primary performance goal (89.4%)., Conclusions and Relevance: This cohort study demonstrated high technical success and low complication rates of excimer laser sheath-assisted retrieval of embedded IVC filters in centers with variable case volume and experience, which suggests a wide applicability of the technique with proper training. The excimer laser sheath offers physicians a valuable tool for retrieval of challenging embedded IVC filters.

Background Improved inferior vena cava (IVC) filters have led to liberalization of the indications for insertion. Increased use, however, has been followed with a potential for unwarranted insertion. There are only sparse data on trends in the use of IVC filters in patients with pulmonary embolism (PE), patients with deep venous thrombosis (DVT) alone, and patients at high risk. We analyzed the National Hospital Discharge Survey (NHDS) database for such trends. Methods We used data from the NHDS, which is based on a national probability sample of discharges from short-stay nonfederal hospitals in 50 states and the District of Columbia. The numbers of sampled patients with DVT, PE, and IVC filters were determined from the International Classification of Diseases, Ninth Revision, Clinical Modification codes at discharge. Results The number of patients who had IVC filters increased from 2000 in 1979 to 49 000 in 1999. In 1999, 45% of IVC filter insertions were in patients with DVT alone, 36% were in patients with PE, and 19% were in patients who presumably were at high risk but did not have DVT or PE listed as a discharge code. The use of IVC filters was more frequent in northeastern states than in western states (P = .01). Conclusions The use of IVC filters increased markedly during the last 2 decades in patients with PE, patients with DVT alone, and patients at risk who had neither PE nor DVT. Randomized controlled trials may lead to improved risk stratification and limit the number of unnecessary filter insertions. [ABSTRACT FROM AUTHOR]

Background: Septic patients are at risk of thromboembolism. However, the Food and Drug Administration guidance for intravascular filters states that "filters should not be implanted in patients with risk of septic embolism." The purpose of this study is to evaluate this restriction. Hypothesis: There is no difference in outcomes following filter placement in patients with and without septicemia. Data Sources: A registry of vena caval filter experiences containing information regarding filter placement and annual examinations of more than 2600 patients obtained during a 15-year period was reviewed. We conducted a MEDLINE search of publications reporting clinical sequelae of filter placement in septic patients. Data Extraction: The registry was searched for patients with a diagnosis of sepsis at filter placement; survival rates, adverse events, and recurrent sepsis or thromboembolism were noted. The MEDLINE search joined results from 7 MeSH headings (vena cava filter,sepsis, septic thromboembolism, vena caval filter contraindication, and filter adverse events) related to filters and sepsis. Data Synthesis: One-hundred seventy-five patients (6.7%) met the criteria and received Greenfield filters. None of the adverse events were related to sepsis, and no filter was removed. Follow-up data were available for 56 patients, with a combined recurrent pulmonary embolism and caval occlusion rate of 1.7%. The 30-day mortality rate was 33%. We noted a significant difference in survival related to the use of anticoagulation therapy (P = .001) and to age (P = .004). The MEDLINE search did not identify any clinical reports of septic filters or the need to remove a filter because of sepsis. Conclusions: Based on our review, the Greenfield filter is a safe method of prophylaxis for septic patients. Rescinding the restriction for use of vena caval filters in septic patients should be considered by regulatory bodies. [ABSTRACT FROM AUTHOR]

Importance: Incidence rates for lower extremity deep vein thrombosis (DVT) range from 88 to 112 per 100 000 person-years and increase with age. Rates of recurrent VTE range from 20% to 36% during the 10 years after an initial event., Observations: PubMed and Cochrane databases were searched for English-language studies published from January 2015 through June 2020 for randomized clinical trials, meta-analyses, systematic reviews, and observational studies. Risk factors for venous thromboembolism (VTE), such as older age, malignancy (cumulative incidence of 7.4% after a median of 19 months), inflammatory disorders (VTE risk is 4.7% in patients with rheumatoid arthritis and 2.5% in those without), and inherited thrombophilia (factor V Leiden carriers with a 10-year cumulative incidence of 10.9%), are associated with higher risk of VTE. Patients with signs or symptoms of lower extremity DVT, such as swelling (71%) or a cramping or pulling discomfort in the thigh or calf (53%), should undergo assessment of pretest probability followed by D-dimer testing and imaging with venous ultrasonography. A normal D-dimer level (ie, D-dimer <500 ng/mL) excludes acute VTE when combined with a low pretest probability (ie, Wells DVT score ≤1). In patients with a high pretest probability, the negative predictive value of a D-dimer less than 500 ng/mL is 92%. Consequently, D-dimer cannot be used to exclude DVT without an assessment of pretest probability. Postthrombotic syndrome, defined as persistent symptoms, signs of chronic venous insufficiency, or both, occurs in 25% to 50% of patients 3 to 6 months after DVT diagnosis. Catheter-directed fibrinolysis with or without mechanical thrombectomy is appropriate in those with iliofemoral obstruction, severe symptoms, and a low risk of bleeding. The efficacy of direct oral anticoagulants-rivaroxaban, apixaban, dabigatran, and edoxaban-is noninferior to warfarin (absolute rate of recurrent VTE or VTE-related death, 2.0% vs 2.2%). Major bleeding occurs in 1.1% of patients treated with direct oral anticoagulants vs 1.8% treated with warfarin., Conclusions and Relevance: Greater recognition of VTE risk factors and advances in anticoagulation have facilitated the clinical evaluation and treatment of patients with DVT. Direct oral anticoagulants are noninferior to warfarin with regard to efficacy and are associated with lower rates of bleeding, but costs limit use for some patients.

Importance: Venous thromboembolism is the second overall leading cause of death for patients with cancer, and there is an approximately 2-fold increase in fatal pulmonary embolism (PE) in patients with cancer. Inferior vena cava (IVC) filters are designed to prevent PE, but defining the appropriate use of IVC filters in patients with cancer remains a substantial unmet clinical need., Objective: To evaluate the association of IVC filters with the development of PE in patients with cancer and deep venous thrombosis (DVT)., Design, Setting, and Participants: A population-based cohort study was conducted using administrative data on 88 585 patients from the state inpatient databases for California (2005-2011) and Florida (2005-2014). Based on diagnostic and procedure codes, patients with cancer and acute lower extremity DVT were identified. All subsequent hospital visits for these patients were evaluated for the placement of an IVC filter, the development of new PE, the development of new DVT, and in-hospital mortality. Data analysis was performed from September 1 to December 1, 2019., Exposures: Placement of an IVC filter., Main Outcomes and Measures: The association of IVC filter placement with rates of new PE and DVT was estimated using a propensity score matching algorithm and competing risk analysis., Results: The study cohort comprised 88 585 patients (45 074 male; median age, 71.0 years [range, 1.0-104.0 years]) with malignant neoplasms who presented to a health care institution with a diagnosis of acute lower extremity DVT. Of these patients, 33 740 (38.1%) underwent IVC filter placement; patients with risk factors such as upper gastrointestinal bleeding (odds ratio, 1.32; 95% CI, 1.29-1.37), intracranial hemorrhage (odds ratio, 1.21; 95% CI, 1.19-1.24), and coagulopathy (odds ratio, 1.09; 95% CI, 1.08-1.10) were more likely to receive an IVC filter. A total of 4492 patients (5.1%) developed a new PE after their initial DVT diagnosis. There was a significant improvement in PE-free survival for these patients compared with those who did not receive IVC filters across the full, unbalanced study cohort as well as after propensity score matching and competing risk analysis (hazard ratio, 0.69; 95% CI, 0.64-0.75; P < .001). Furthermore, IVC filter placement reduced the development of PE in patients with very high-risk malignant neoplasms (eg, pancreaticobiliary cancer), high-risk malignant neoplasms (eg, lung cancer), and low-risk malignant neoplasms (eg, prostate cancer). After accounting for anticoagulation use and imbalanced risk factors, IVC filter placement did not increase the risk of new DVT development., Conclusions and Relevance: This study suggests that, for patients with cancer and DVT and bleeding risk factors, IVC filter placement is associated with an increased rate of PE-free survival.

Importance: Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group., Objective: To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias., Design, Setting, and Participants: This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018., Exposure: Inferior vena cava filter placement., Main Outcomes and Measures: Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable., Results: Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P < .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P < .001)., Conclusions and Relevance: After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation.

Importance: Trauma patients admitted to the hospital are at increased risk of bleeding and thrombosis. The use of inferior vena cava (IVC) filters in this population has been increasing, despite a lack of high-quality evidence to demonstrate their efficacy., Objective: To determine if IVC filter insertion in trauma patients affects overall mortality., Design, Setting, and Participants: This retrospective cohort study used stratified 3:1 propensity matching to select a control population similar to patients who underwent IVC filter insertion at Boston Medical Center (a level I trauma center at Boston University School of Medicine) between August 1, 2003, and December 31, 2012. Among patients with an IVC filter and matched controls, age, sex, race/ethnicity, and Injury Severity Score were entered into a multivariable logistic regression model to calculate a propensity score. Matching was stratified by the date of injury., Main Outcomes and Measures: Multivariable logistic regression was used to compare hospital mortality across both groups, adjusting for age, sex, race/ethnicity, Injury Severity Score, and brain injury severity using the head and neck Abbreviated Injury Score. To determine any significant difference in mortality, patient characteristics and mortality data from the National Death Index were analyzed in all patients and in those who survived 24, 48, and 72 hours after injury, as well as at hospital discharge., Results: Among 451 trauma patients with an IVC filter and 1343 matched controls without an IVC filter, the mean (SD) age was 47.4 (21.5) years. The median Injury Severity Score overall was 24 (range, 1-75). Based on a mean follow-up of 3.8 years (range, 0-9.4 years), there was no significant difference in overall mortality or cause of mortality in patients with vs without an IVC filter who survived more than 24 hours from the time of injury, independent of the presence or absence of deep vein thrombosis or pulmonary embolism at the time of IVC filter placement. Additional analyses at shorter intervals of 6 months and 1 year after discharge also showed no significant difference between the 2 groups of patients. Eight percent (38 of 451) of the IVC filters were removed at Boston Medical Center during the follow-up period., Conclusions and Relevance: The research herein demonstrates no significant difference in survival in trauma patients with vs without placement of an IVC filter, whether in the presence or absence of venous thrombosis. The use of IVC filters in this population should be reexamined because filter removal rates are low and there is increased risk of morbidity in patients with filters that remain in place.

Importance: Although retrievable inferior vena cava filters are frequently used in addition to anticoagulation in patients with acute venous thromboembolism, their benefit-risk ratio is unclear., Objective: To evaluate the efficacy and safety of retrievable vena cava filters plus anticoagulation vs anticoagulation alone for preventing pulmonary embolism recurrence in patients presenting with acute pulmonary embolism and a high risk of recurrence., Design, Setting, and Participants: Randomized, open-label, blinded end point trial (PREPIC2) with 6-month follow-up conducted from August 2006 to January 2013. Hospitalized patients with acute, symptomatic pulmonary embolism associated with lower-limb vein thrombosis and at least 1 criterion for severity were assigned to retrievable inferior vena cava filter implantation plus anticoagulation (filter group; n = 200) or anticoagulation alone with no filter implantation (control group; n = 199). Initial hospitalization with ambulatory follow-up occurred in 17 French centers., Interventions: Full-dose anticoagulation for at least 6 months in all patients. Insertion of a retrievable inferior vena cava filter in patients randomized to the filter group. Filter retrieval was planned at 3 months from placement., Main Outcomes and Measures: Primary efficacy outcome was symptomatic recurrent pulmonary embolism at 3 months. Secondary outcomes were recurrent pulmonary embolism at 6 months, symptomatic deep vein thrombosis, major bleeding, death at 3 and 6 months, and filter complications., Results: In the filter group, the filter was successfully inserted in 193 patients and was retrieved as planned in 153 of the 164 patients in whom retrieval was attempted. By 3 months, recurrent pulmonary embolism had occurred in 6 patients (3.0%; all fatal) in the filter group and in 3 patients (1.5%; 2 fatal) in the control group (relative risk with filter, 2.00 [95% CI, 0.51-7.89]; P = .50). Results were similar at 6 months. No difference was observed between the 2 groups regarding the other outcomes. Filter thrombosis occurred in 3 patients., Conclusions and Relevance: Among hospitalized patients with severe acute pulmonary embolism, the use of a retrievable inferior vena cava filter plus anticoagulation compared with anticoagulation alone did not reduce the risk of symptomatic recurrent pulmonary embolism at 3 months. These findings do not support the use of this type of filter in patients who can be treated with anticoagulation., Trial Registration: clinicaltrials.gov Identifier: NCT00457158.

Importance: Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common, potentially lethal condition with acute morbidity., Objective: To review the etiology of VTE and the 3 phases of VTE treatment: acute (first 5-10 days), long-term (from end of acute treatment to 3-6 months), and extended (beyond 3-6 months)., Evidence Review: Cochrane reviews, meta-analyses, and randomized controlled trials, as well as other clinical trials for topics not covered by the former, were reviewed. Literature searches using broad terms were used to find meta-analyses published in the last 15 years. The ninth edition of the American College of Chest Physicians Antithrombotic Therapy Guidelines was used to supplement the literature search. Guidelines from specialty organizations were consulted when relevant. The Canadian Agency for Drugs and Technologies in Health was searched for relevant cost-effectiveness studies. We also searched our own literature database of 8386 articles for relevant research., Findings: Low-molecular-weight heparin (LMWH) along with with vitamin K antagonists and the benefits and proven safety of ambulation have allowed for outpatient management of most cases of DVT in the acute phase. Development of new oral anticoagulants further simplifies acute-phase treatment and 2 oral agents can be used as monotherapy, avoiding the need for LMWH. Patients with PE can also be treated in the acute phase as outpatients, a decision dependent on prognosis and severity of PE. Thrombolysis is best reserved for severe VTE; inferior vena cava filters, ideally the retrievable variety, should be used when anticoagulation is contraindicated. In general, DVT and PE patients require 3 months of treatment with anticoagulants, with options including LMWH, vitamin K antagonists, or direct factor Xa or direct factor IIa inhibitors. After this time, decisions for further treatment are based on balancing the risk of VTE recurrence, determined by etiology of the VTE (transient risk factors, unprovoked or malignancy associated), against the risk of major hemorrhage from treatment. Better prediction tools for major hemorrhage are needed. Experience with new oral anticoagulants as acute, long-term, and extended therapy options is limited as yet, but as a class they appear to be safe and effective for all phases of treatment., Conclusions and Relevance: The mainstay of VTE treatment is anticoagulation, while interventions such as thrombolysis and inferior vena cava filters are reserved for limited circumstances. Multiple therapeutic modes and options exist for VTE treatment with small but nonetheless important differential effects to consider. Anticoagulants will probably always increase bleeding risk, necessitating tailored treatment strategies that must incorporate etiology, risk, benefit, cost, and patient preference. Although great progress has been made, further study to understand individual patient risks is needed to make ideal treatment decisions.

Importance: Trauma is known to be one of the strongest risk factors for pulmonary embolism (PE). Current guidelines recommend low-molecular-weight heparin therapy for prevention of PE, but trauma places some patients at risk of excess bleeding. Experts are divided on the role of prophylactic inferior vena cava (IVC) filters to prevent PE., Objective: To perform a systematic review and meta-analysis examining the comparative effectiveness of prophylactic IVC filters in trauma patients, particularly in preventing PE, fatal PE, and mortality., Data Sources: We searched the following databases for primary studies: MEDLINE, EMBASE, Scopus, CINAHL, International Pharmaceutical Abstracts, clinicaltrial.gov, and the Cochrane Library (all through July 31, 2012). We developed a search strategy using medical subject headings terms and text words of key articles that we identified a priori. We reviewed the references of all included articles, relevant review articles, and related systematic reviews to identify articles the database searches might have missed., Study Selection: We reviewed titles followed by abstracts to identify randomized clinical trials or observational studies with comparison groups reporting on the effectiveness and/or safety of IVC filters for prevention of venous thromboembolism in trauma patients., Data Extraction and Synthesis: Two investigators independently reviewed abstracts and abstracted data. For studies amenable to pooling with meta-analysis, we pooled using the random-effects model to analyze the relative risks. We graded the quantity, quality, and consistency of the evidence by adapting an evidence-grading scheme recommended by the Agency for Healthcare Research and Quality., Results: Eight controlled studies compared the effectiveness of no IVC filter vs IVC filter on PE, fatal PE, deep vein thrombosis, and/or mortality in trauma patients. Evidence showed a consistent reduction of PE (relative risk, 0.20 [95% CI, 0.06-0.70]; I(2)=0%) and fatal PE (0.09 [0.01-0.81]; I(2)=0%) with IVC filter placement, without any statistical heterogeneity. We found no significant difference in the incidence of deep vein thrombosis (relative risk, 1.76 [95% CI, 0.50-6.19]; P=.38; I(2)=56.8%) or mortality (0.70 [0.40-1.23]; I(2)=6.7%). The number needed to treat to prevent 1 additional PE with IVC filters is estimated to range from 109 (95% CI, 93-190) to 962 (819-2565), depending on the baseline PE risk., Conclusions and Relevance: The strength of evidence is low but supports the association of IVC filter placement with a lower incidence of PE and fatal PE in trauma patients. Which patients experience benefit enough to outweigh the harms associated with IVC filter placement remains unclear. Additional well-designed observational or prospective cohort studies may be informative.

We sought to assess the comparative effectiveness and safety of pharmacologic and mechanical strategies to prevent venous thromboembolism (VTE) in patients undergoing bariatric surgery. We searched (through August 2012) for primary studies that had at least 2 different interventions. Of 30,902 citations, we identified 8 studies of pharmacologic strategies and 5 studies of filter placement. No studies randomized patients to receive different interventions. One study suggested that low-molecular-weight heparin is more efficacious than unfractionated heparin in preventing VTE (0.25% vs 0.68%, P < .001), with no significant difference in bleeding. One study suggested that prolonged therapy (after discharge) with enoxaparin sodium may prevent VTE better than inpatient treatment only. There was insufficient evidence supporting the hypothesis that filters reduce the risk of pulmonary embolism, with a point estimate suggesting increased rates with filters (pooled relative risk [RR], 1.21 95% CI, 0.57-2.56). There was low-grade evidence that filters are associated with higher mortality (pooled RR, 4.30 95% CI, 1.60-11.54) and higher deep vein thrombosis rates (2.94 1.35-6.38). There was insufficient evidence to support that augmented subcutaneous enoxaparin doses (>40 mg daily or 30 mg twice daily) are more efficacious than standard dosing, with a trend toward increased bleeding. Of note, for both filters and augmented pharmacologic dosing strategies, patients at highest risk for VTE were more likely to receive more intensive interventions, limiting our ability to attribute outcomes to prophylactic strategies used.

The US Surgeon General estimates that 100,000 to 180,000 deaths occur annually from acute pulmonary embolism (PE) in the United States. The case of Ms A, a 60-year-old woman with acute PE and right ventricular dysfunction (submassive PE), illustrates the clinical challenge of identifying this high-risk patient population and determining when more aggressive immediate therapy should be pursued in addition to standard anticoagulation. The clinical examination, electrocardiogram, cardiac biomarkers, chest computed tomography, and echocardiography can be used to risk stratify patients with acute PE. Current options for more aggressive intervention in the treatment of patients with acute PE who are at increased risk of an adverse clinical course include systemic fibrinolysis, pharmacomechanical catheter-directed therapy, surgical pulmonary embolectomy, and inferior vena cava filter insertion. Determination of the optimal duration of anticoagulation and lifestyle modification to reduce overall cardiovascular risk are critical components of the long-term therapy of patients with acute PE.

Hypothesis: Pulmonary embolism (PE) and deep venous thrombosis (DVT) in trauma are related., Design: Retrospective review of medical records., Setting: Academic level I trauma center., Patients: Trauma patients who underwent computed tomographic pulmonary angiography (CTPA) with computed tomographic venography (CTV) of the pelvic and proximal lower extremity veins over a 3-year period (January 1, 2004, to December 31, 2006) were reviewed. Data on demographics, injury type and severity, imaging findings, hospital length of stay, and mortality were collected., Main Outcome Measures: Pulmonary embolism and DVT., Results: Among 247 trauma patients undergoing CTPA/CTV, PE was diagnosed in 46 (19%) and DVT in 18 (7%). Eighteen PEs were central (main or lobar pulmonary arteries), and 28 PEs were peripheral (segmental or subsegmental branches). Pulmonary embolism occurred within the first week of injury in two-thirds of patients. Seven patients with PE (4 femoral, 2 popliteal, and 1 iliac) had DVT. Pulmonary embolism was central in 5 patients and peripheral in 2 patients. No significant differences were noted in any of the examined variables between patients with PE having DVT and those not having DVT., Conclusions: Few patients with PE have DVT of the pelvic or proximal lower extremity veins. Pulmonary embolism may not originate from these veins, as commonly believed, but instead may occur de novo in the lungs. These findings have implications for thromboprophylaxis and, particularly, the value of vena cava filters.

Hypothesis: Prophylactic temporary inferior vena cava (IVC) filters are safe and effective in critically ill patients at high risk for venous thromboembolism., Design: Prospective cohort study., Setting: Urban level I trauma center., Subjects: Multiple-trauma patients and critically ill surgical patients undergoing prophylactic temporary IVC filter placement. All patients were at high risk for venous thromboembolism but had contraindications to low-dose heparin therapy., Interventions: The interventional radiologist used the femoral or internal jugular approach to place a removable IVC filter in all patients. The filter was removed when the patient could safely be treated with heparin. If the filter could not be removed by 14 days, it was relocated to prevent incorporation precluding retrieval., Main Outcome Measures: Complications of filter insertion and removal, deep venous thrombosis, and pulmonary embolism., Results: From May 1, 2001, to October 1, 2002, 44 patients underwent placement of temporary IVC filters. Thirty-seven patients (84%) were severely injured. The mean +/- SD age was 37 +/- 3 years, and 55% were men. The mean +/- SD Injury Severity Score of the trauma patients was 33 +/- 2, and all had blunt injury. There were no complications associated with filter insertion or removal. Nine patients required filter relocation prior to retrieval. Three filters could not be removed: 2 secondary to significant clots trapped below the filter and 1 because of angulation resulting in the inability to grasp the filter. There were no documented instances of venous thromboembolism following IVC filter placement and removal., Conclusions: Temporary IVC filters are safe and effective in critically ill surgical and trauma patients and allow an aggressive approach to prevention of venous thromboembolism in this challenging group of patients.

Hypothesis: Insertion of inferior vena cava filters (IVCFs) can prophylactically reduce pulmonary embolism (PE) in trauma patients., Design: Retrospective review., Setting: Urban, level I trauma center., Patients: Two hundred blunt trauma patients undergoing IVCF placement., Interventions: In 122 patients who had already been diagnosed as having deep vein thrombosis (DVT) (112 patients) and/or PE (22 patients), the insertion of the IVCF was considered "therapeutic." In 78 patients who had no evidence of DVT or PE but who were considered to be at high risk for a PE, the IVCF was considered "prophylactic.", Main Outcome Measures: Incidence of PE and related mortality and morbidity in therapeutic vs prophylactic IVCFs., Results: The number of prophylactic IVCFs inserted increased significantly from only 4% (3/68 cases) from 1991 through 1996, up to 57% (75/132 cases) from 1997 to June 2001. Although the mean +/- SD age (51 +/- 20 years vs 41 +/- 15 years; P<.001) was higher in the therapeutic group, there was no difference in the mean +/- SD Injury Severity Scores (20 +/- 12 vs 21 +/- 11). Therapeutic filters were placed much later after injury (mean +/- SD time, 11 +/- 7 vs 3 +/- 2 days; P<.001). The mortality rate was 11% (13/122 patients) in patients having a therapeutic IVCF, as compared with only 3% (2/78 patients) in those placed prophylactically (P =.07). None of the patients who had placement of a prophylactic IVCF developed subsequent PE. The incidence of PE decreased in all blunt trauma patients from 0.29% before 1997 to 0.15% after January 1, 1997, when 57% of the IVCF inserted were prophylactic (P =.06)., Conclusions: Prophylactic IVCFs should be inserted within 48 hours of injury in specific trauma patients at high risk for PE and with contraindications to anticoagulation.

Placement of the Greenfield filter above the renal veins was necessary in 71 (9%) of 821 total patients in the filter registries of two institutions. The status of 60 patients (85%) could be verified, with follow-up data ranging from 18 months to 16 years (average, 53 months). Of 24 deaths (34%), none was from recurrent embolism or renal failure; death was most commonly associated with a malignant neoplasm. The recurrent embolism rate was 4%, identical to the infrarenal experience. Duplex evaluation of the filters in 22 patients, representing the majority (61%) of living patients, showed that all the filters were patent. Sixteen patients (41%) had lower-extremity edema that predated filter insertion, and in no patient did the results of noninvasive venous studies worsen. Filter fracture (two patients) or distal migration (two patients) had no clinical sequelae, and there was no evidence of renal dysfunction. For thrombus extending to the level of the renal veins or within them and for pregnant patients or women of childbearing age, suprarenal placement of the Greenfield filter is safe and effective, with no filter obstruction seen in follow-up extending to 16 years.