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Concern regarding the exponential increase in optional utilization of inferior vena cava filters (IVCFs) in the early 2000s with a persistent low retrieval rate nationwide has resulted in increased scrutiny regarding clinical application of IVCFs. IVCFs are used in a variety of clinical scenarios, ranging from thromboembolic protection in patients with deep venous thrombosis and contraindication to anticoagulation to prophylactic deployment in multitrauma and critically ill patients. Evidence supporting IVCFs as mechanical thromboembolic protection in certain clinical scenarios has been established through evidenced-based guidelines. As an adjunct to evidence-based guidelines, appropriateness criteria to address specific clinical scenarios and facilitate clinical decision making when considering placement of an IVCF have been developed. In this review, current evidence-based and appropriateness guidelines are summarized., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease., Materials and Methods: A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations., Results: The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations., Conclusions: Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population., (Copyright © 2020 SIR. Published by Elsevier Inc. All rights reserved.)

Endovascular management of pulmonary embolism can be divided into therapeutic and prophylactic treatments. Prophylactic treatment includes inferior vena cava filter placement, whereas endovascular therapeutic interventions include an array of catheter-directed therapies. The indications for both modalities have evolved over the last decade as new evidence has become available., Competing Interests: Disclosure A.K. Sista: research support from Penumbra, Inc., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Competing Interests: Competing interests disclosed: Declaration of interests based on NICE’s policy on conflicts of interests (available at https://www.nice.org.uk/Media/Default/About/Who-we-are/Policies-and-procedures/declaration-of-interests-policy.pdf). The authors’ full statements can be viewed at https://www.nice.org.uk/guidance/ng158/documents/register-of-interests

Background: Severely injured trauma patients are at high risk of developing deep venous thrombosis and pulmonary emboli (PE), and may have contraindications to prophylactic or therapeutic anticoagulation. Retrievable inferior vena cava filters (rIVCFs) are used to act as a mechanical obstruction to prevent PE in high risk populations and those with deep venous thrombosis who cannot be anticoagulated. The removal rate of rIVCFs is variable in trauma centers, including our previous published rate of 50% to 89%/year. Indwelling filters carry a risk of significant morbidity and the success of retrieval decreases as the dwell time increases. We hypothesized that once patients could receive appropriate prophylactic or therapeutic anticoagulation, rIVCF could be removed before hospital discharge without impact on occurrence or recurrence of PE., Methods: All trauma patients with rIVCF placed and removed between January 2006 and August 2018 were reviewed. We collected data from record review from admission to 6 months postfilter removal, including demographics, filter indication, filter type, dwell time, placement and removal complications, antithrombosis medications, location of venous thromboembolism, complications, and discharge disposition. Exposure of interest was timing of filter removal: before (BEF) or after hospital discharge (AFT). The outcome of interest was whether the patient had a documented PE within 6 months of filter removal., Results: A total of 281 rIVCFs were placed, 218 were eligible for removal, 72.4% (158/218) were retrieved with 63% (100/158) removed before discharge. Mean filter duration was 26 days and 103 days for the before and after groups, respectively. No differences (p > 0.05) were noted in the distribution of demographic and clinical factors except for filter indication (venous thromboembolism indication, 95% in AFT vs. 74% in BEF, p = 0.0043). Postremoval PE rates were 0% BEF and 1% AFT (Fisher's exact test, p = 1.000)., Conclusion: Our results suggest that removal of rIVCFs before discharge once patients are appropriately anticoagulated is a safe strategy to improve retrieval rates., Level of Evidence: Therapeutic, level V.

The association between inferior vena cava filter (IVC) use and outcome in patients presenting with major bleeding during anticoagulation for venous thromboembolism (VTE) has not been thoroughly investigated. We used the RIETE registry to compare the 30-day outcomes (death, major re-bleeding or VTE recurrences) in VTE patients who bled during the first 3 months of therapy, regarding the insertion of an IVC filter. A propensity score matched (PSM) analysis was performed to adjust for potential confounders. From January 2001 to September 2016, 1065 VTE patients had major bleeding during the first 3 months of anticoagulation (gastrointestinal 370; intracranial 124). Of these, 122 patients (11%) received an IVC filter. Patients receiving a filter restarted anticoagulation later (median, 4 vs. 2 days) and at lower doses (95 ± 52 IU/kg/day vs. 104 ± 55 of low-molecular-weight heparin) than those not receiving a filter. During the first 30 days after bleeding (after excluding 246 patients who died within the first 24 h), 283 patients (27%) died, 63 (5.9%) had non-fatal re-bleeding and 19 (1.8%) had recurrent pulmonary embolism (PE). In PSM analysis, patients receiving an IVC filter (n = 122) had a lower risk for all-cause death (HR 0.49; 95% CI 0.31-0.77) or fatal bleeding (HR 0.16; 95% CI 0.07-0.49) and a similar risk for re-bleeding (HR 0.55; 95% CI 0.23-1.40) or PE recurrences (HR 1.57; 95% CI 0.38-6.36) than those not receiving a filter (n = 429). In VTE patients experiencing major bleeding during the first 3 months, use of an IVC filter was associated with reduced mortality rates.Clinical Trial Registration NCT02832245.

The nature of many combat wounds puts patients at a high risk of developing deep venous thrombosis (DVT) and pulmonary embolism (PE), which fall under the broader disease category of venous thromboembolism (VTE). In addition to the hypercoagulable state induced by trauma, massive injuries to the extremities, prolonged immobility, and long fixed wing transport times to higher echelons of care are unique risk factors for venous thromboembolism in the combat-injured patient. These risk factors mandate aggressive prophylaxis for DVT and PE that can effectively be achieved by the use of lower extremity sequential compression devices and low dose unfractionated heparin or low molecular weight heparin. In addition, inferior vena cava filters are often used for PE prophylaxis when chemical DVT prophylaxis fails or is contraindicated. The following Department of Defense (DoD) Joint Trauma System (JTS) Clinical Practice Guideline (CPG) discusses the current recommendations for the prevention of DVT and PE including the use of inferior vena cava filters (IVCFs).

Vena cava filters are implantable devices that are placed to trap thrombus originating in the lower extremities and prevent it from migrating to the lungs. In general, inferior vena cava (IVC) filters are indicated for patients who cannot receive anticoagulation. Other indications for IVC filtration are less clear, and guidelines vary. All patients who have a retrievable IVC filter should be followed, and the removal of the IVC filter should be considered once its indication is lost., (Copyright © 2018 Elsevier Inc. All rights reserved.)

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.

: The indications for the use of an inferior vena cava filter (IVCF) in the context of deep venous thrombosis to prevent pulmonary embolism remain controversial. Despite wide use in clinical practice, great variation exists in national and international guidelines in regard to the indications. In addition, clinical practice is based on poor-quality data from trauma and bariatric surgery with a high incidence of complications. It is often difficult to assess their efficacy and lack of filter retrieval appears to be a substantial issue compared with a potential benefit by insertion of these devices. Complications usually refer to increased risk of deep venous thrombosis, filter perforation, filter penetration, filter migration, inferior vena cava occlusion and subsequently failure in pulmonary embolism prevention. Evidence from low-quality studies or registries, with small numbers of patients and conflicting findings, does not allow for a strong recommendation for or against the use of IVCFs. IVCFs should only be considered in cases of very high risk of pulmonary embolism and in perioperative situations at very high risk of bleeding, resulting in a prolonged contra-indication to pharmacological prophylaxis.

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.

Inferior vena cava (IVC) filters are medical devices designed to provide a mechanical barrier to the passage of emboli from the deep veins of the legs to the heart and lungs. Despite decades of development and clinical use, IVC filters still fail to prevent the passage of all hazardous emboli. The objective of this study is to (1) develop a resolved two-way computational model of embolus transport, (2) provide verification and validation evidence for the model, and (3) demonstrate the ability of the model to predict the embolus-trapping efficiency of an IVC filter. Our model couples computational fluid dynamics simulations of blood flow to six-degree-of-freedom simulations of embolus transport and resolves the interactions between rigid, spherical emboli and the blood flow using an immersed boundary method. Following model development and numerical verification and validation of the computational approach against benchmark data from the literature, embolus transport simulations are performed in an idealized IVC geometry. Centered and tilted filter orientations are considered using a nonlinear finite element-based virtual filter placement procedure. A total of 2048 coupled CFD/6-DOF simulations are performed to predict the embolus-trapping statistics of the filter. The simulations predict that the embolus-trapping efficiency of the IVC filter increases with increasing embolus diameter and increasing embolus-to-blood density ratio. Tilted filter placement is found to decrease the embolus-trapping efficiency compared with centered filter placement. Multiple embolus-trapping locations are predicted for the IVC filter, and the trapping locations are predicted to shift upstream and toward the vessel wall with increasing embolus diameter. Simulations of the injection of successive emboli into the IVC are also performed and reveal that the embolus-trapping efficiency decreases with increasing thrombus load in the IVC filter. In future work, the computational tool could be used to investigate IVC filter design improvements, the effect of patient anatomy on embolus transport and IVC filter embolus-trapping efficiency, and, with further development and validation, optimal filter selection and placement on a patient-specific basis.

Purpose: To evaluate the effects of physician familiarity with current evidence and guidelines on inferior vena cava (IVC) filter use and the availability of IVC filter tracking infrastructure on retrieval rates., Materials and Methods: Fourteen continuing medical education-approved in-hospital grand rounds covering evidence-based review of the literature on IVC filter efficacy, patient-centered outcomes, guidelines for IVC filter indications, and complications were performed across a large United States (US) health care region serving more than 3.5 million members. A computer-based IVC filter tracking system was deployed simultaneously. IVC filter use, rates of attempted retrieval, and fulfillment of guidelines for IVC filter indications were retrospectively evaluated at each facility for 12 months before intervention (n = 427) and for 12 months after intervention (n = 347)., Results: After education, IVC filter use decreased 18.7%, with a member enrollment-adjusted decrease of 22.2%, despite an increasing IVC filter use trend for 4 years. Reduction in IVC filter use at each facility strongly correlated with physician attendance at grand rounds (r = -0.69; P = .007). Rates of attempted retrieval increased from 38.9% to 54.0% (P = .0006), with similar rates of successful retrieval (82.3% before education and 85.8% after education on first attempt). Improvement in IVC filter retrieval attempts correlated with physician attendance at grand rounds (r = 0.51; P = .051). IVC filter dwell times at first retrieval attempt were similar (10.2 wk before and 10.8 wk after)., Conclusions: Physician education dramatically reduced IVC filter use across a large US health care region, and represents a learning opportunity for physicians who request and place them. Education and a novel tracking system improved rates of retrieval for IVC filter devices., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: To design a sustainable process to improve optional inferior vena cava (IVC) filter retrieval rates based on the Define, Measure, Analyze, Improve, Control (DMAIC) methodology of the Six Sigma process improvement paradigm., Materials and Methods: DMAIC, an acronym for Define, Measure, Analyze, Improve, and Control, was employed to design and implement a quality improvement project to increase IVC filter retrieval rates at a tertiary academic hospital. Retrievable IVC filters were placed in 139 patients over a 2-year period. The baseline IVC filter retrieval rate (n = 51) was reviewed through a retrospective analysis, and two strategies were devised to improve the filter retrieval rate: (a) mailing of letters to clinicians and patients for patients who had filters placed within 8 months of implementation of the project (n = 43) and (b) a prospective automated scheduling of a clinic visit at 4 weeks after filter placement for all new patients (n = 45). The effectiveness of these strategies was assessed by measuring the filter retrieval rates and estimated increase in revenue to interventional radiology., Results: IVC filter retrieval rates increased from a baseline of 8% to 40% with the mailing of letters and to 52% with the automated scheduling of a clinic visit 4 weeks after IVC filter placement. The estimated revenue per 100 IVC filters placed increased from $2,249 to $10,518 with the mailing of letters and to $17,022 with the automated scheduling of a clinic visit., Conclusions: Using the DMAIC methodology, a simple and sustainable quality improvement intervention was devised that markedly improved IVC filter retrieval rates in eligible patients., (Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.)

In this study, the trapping ability of the Günther Tulip and Celect inferior vena cava filters was evaluated. Thrombus capture rates of the filters were tested in vitro in horizontal position with thrombus diameters of 3 and 6mm and tube diameter of 19mm. The filters were tested in centered and tilted positions. Sets of 30 clots were injected into the model and the same process was repeated 20 times for each different condition simulated. Pressure drop experienced along the system was also measured and the percentage of clots captured was recorded. The Günther Tulip filter showed superiority in all cases, trapping almost 100% of 6mm clots both in an eccentric and tilted position and trapping 81.7% of the 3mm clots in a centered position and 69.3% in a maximum tilted position. The efficiency of all filters tested decreased as the size of the embolus decreased and as the filter was tilted. The injection of 6 clots raised the pressure drop to 4.1mmHg, which is a reasonable value that does not cause the obstruction of blood flow through the system., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Many studies have supported the efficacy of inferior vena cava filters (IVCF) in the setting of venous thromboembolic disease, particularly in oncologic patients who are at increased risk. The advent of retrievable IVCF designs has prompted dramatically expanded use for patients with widely accepted indications but also disproportionately so in patients with so-called extended indications. At the same time, an alarming increase in filter-related complications has been reported both in the literature and through regulatory agencies, leading to government agency-issued warnings. The synergistic effect of these two interconnected phenomena is explained through a careful review of the evolution of IVCF device design. Critical differences exist when comparing retrievable IVCF and permanent IVCF. IVCF utilization can be optimized by prospectively identifying which patients are best served by a specific IVCF device. Careful follow-up strategies are also needed to ensure that all IVCFs are removed as soon as they are no longer needed. Finally, adjunctive techniques for removing "difficult" filters help maximize the number of IVCF removed and minimize IVCF left implanted needlessly., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Venous thromboembolism is common. Most pulmonary emboli arise as thromboses in the deep veins of the lower extremities and may result in serious complications. Inferior vena cava filters (IVCF) are intended to prevent the passage of deep vein thrombosis to the pulmonary arteries. Accepted indications for IVCF placement include the presence of acute venous thromboembolism with inability to administer anticoagulation medication or failure of anticoagulation. Despite these clear indications, IVCF have been commonly placed in patients for primary prevention of pulmonary emboli in patients deemed to be at high risk, along with several other "soft" indications. As a result, IVCF use has been rising over the past 2 decades, especially given the retrievable nature of modern devices. Nonetheless, IVCF are not free of complications, which may occur during implantation and retrieval and while retained in the body. Despite this increase in use, the long-term efficacy remains unclear, and the management of patients with retained filters is often controversial. Finally, filter retrieval in eligible patients is relatively infrequent, suggesting that systems must be in place to improve appropriate filter use and to increase retrieval., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Venous thromboembolic disease remains a serious complication following lower extremity total joint arthroplasty. Postoperative thromboembolic complications, which include symptomatic deep vein thrombosis, bleeding, and pulmonary embolus, are recognized causes of patient morbidity, mortality, increased length of stay, and higher healthcare costs. Various thromboprophylaxis guidelines have been recommended to prevent and thereby reduce the incidence of such events. However, despite various studies exploring prophylaxis measures, the incidence of venous thromboembolic events has remained relatively unchanged over the past 10 years. We therefore aimed to: (1) evaluate the current 2011 American Academy of Orthopaedic Surgeons (AAOS) and the 2012 American College of Chest Physicians (ACCP) recommendations concerning venous thromboembolic disease after lower extremity joint arthroplasty; and (2) report on different modalities of prophylaxis, specifically, pharmacological agents, mechanical compression devices, and inferior vena cava filters. Both AAOS and ACCP guidelines recommend a combined approach with mechanical compression devices and pharmacological prophylaxis. A major difference is that the AAOS work group does not recommend specific pharmacological agents, whereas the ACCP guidelines give specific recommendations. Additionally, routine primary thromboprophylaxis with inferior vena cava filters is only recommended when there are contraindications to anticoagulation therapy.

Purpose: Inferior vena cava (IVC) filter placement has increased significantly over the past few decades, but indications for filter placement vary widely depending on which professional society recommendations are followed, and it is uncertain how compliant physicians are in adhering to guidelines. This study assessed documented indications for IVC filter placement and evaluated compliance with standards set by the American College of Chest Physicians (ACCP) and the Society of Interventional Radiology (SIR)., Materials and Methods: A single-center, retrospective medical record review in a metropolitan, 652-bed, acute care, teaching hospital. Inpatient filter placement over a 26-month period was reviewed. The study measured compliance with established guidelines, relationship of medical specialty to filter placement, and evaluation of self-referral patterns among physicians., Results: Compliance with established ACCP guidelines was poor regardless of whether the IVC filter insertion was performed by interventional radiology (IR; 43.5%), vascular surgery (VS; 39.9%), or interventional cardiology (IC; 33.3%) staff. Compliance with the less restrictive SIR guidelines was better (77.5%, 77.1%, and 80% for IR, VS, and IC, respectively). There was a greater degree of guideline compliance when filter placement was recommended by internal medicine (IM)-trained physicians than by non-IM-trained physicians: 46.3% of IR-placed filters requested by IM physicians met ACCP criteria whereas only 24.0% of filters recommended by non-IM specialties were compliant with criteria (P = .03). In the VS group, these compliance rates were 45.8% and 31.5%, respectively (P = .03). Among IR-placed filters, 84.0% of IM-recommended filter placements were compliant with SIR guidelines, versus only 48.0% of non-IM-recommended placements (P ≤ .001). In the VS group, these compliance rates were 87.8% and 69.6%, respectively (P ≤ .001)., Conclusions: There is poor physician compliance with guidelines for IVC filter placement. Most filter indications meeting SIR guidelines are for patients classified as "falls risks," failures of anticoagulation, patients with limited cardiopulmonary reserve and patients non compliant with anticoagulation medications. This single-center study suggests a need for harmonization of current guidelines espoused by professional societies., (Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.)

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism (PE), is a major cause of morbidity and mortality. Parenteral anticoagulant treatment with full-dose unfractioned heparin, low-molecular-weight-heparin, or fondaparinux, followed by oral treatment with the vitamin K antagonists, is recommended for the majority of patients. However, in the presence of contraindications to anticoagulant treatment, bleeding complications during antithrombotic treatment, or VTE recurrences despite optimal anticoagulation, interruption of the inferior vena cava with a filter is a potential option aimed to prevent life-threatening PE. Currently, the vast majority of filters implanted worldwide are of the permanent type, but their use is associated with a number of long term complications. Non-permanent filters represent an important alternative, and in particular retrievable filters are an attractive option because they may be either left in place permanently or safely retrieved after a quite long period when they become unnecessary. In this review, we summarize the currently available literature regarding retrievable vena cava filters and we discuss current evidences on their efficacy and safety. Moreover, the appropriate indications for their use in daily clinical practice are reviewed.

The blockage of a vena cava filter (VCF) by the captured blood clots presents a serious problem to the patients. Commercially available cone-shaped VCFs such as the Gunther Tulip filter has an inherent structural flaw that leads the captured blood clots to be trapped in their front spire areas where the flow-induced shear stress is relatively low so that the clots cannot dissolve fast enough and will accumulate, gradually block the central passages of the filters. It is well known that for a Hagen-Poiseuille flow in a circular tube, the flow-induced shear stress is highest at the wall of the tube and lowest along its axis. Herein, we hypothesize that by reversely deploying a cone-shaped filter in the vena cava, the filter's blockage problem might be prevented. First of all, this kind of deployment scenario can force the captured blood clots to stay in the peripheral areas of the vena cava and keep the central passage of the filter unblocked. Secondly, this scenario can expose the captured blood clots to relatively high shear stress that may dissolve the clots faster., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Although use of inferior vena cava (IVC) filters for prophylaxis against pulmonary embolism (PE) is well reported in adults, long-term studies in children are lacking. We performed retrospective review of imaging and clinical database of IVC filters for the last 12 years. Thirty-five patients (mean age: 15.5 y) underwent filter placement and/or retrieval. Indications for placement were contraindication to anticoagulation with known deep venous thrombosis (DVT) (18) or high risk of venous thromboembolism (5), recurrent DVT despite anticoagulation (1), and prophylaxis before endovascular thrombolysis (8). All filter placements were technically successful without any complications. Filter retrieval was successful in 15 of 19 attempted (79%) at a mean of 42 days. Two complications occurred during retrieval: IVC stenosis successfully treated with angioplasty and contained IVC perforation. Endothelialization of filter prevented retrieval in 4 patients. Mean follow-up was 29.3 months. No patients had IVC thrombosis, breakthrough pulmonary embolism, filter fracture, or embolism. Two patients had recurrent DVT. Our results indicate that IVC filters can be successfully placed and retrieved in children with minimal procedural complications; follow-up demonstrates acceptable complication rate owing to presence of filters. Prophylactic IVC filter placement may be considered before endovascular thrombolysis for lower extremity DVT. Retrievable filters should be used in children for appropriate indications.

Background: There is strong controversy as to whether to use filters temporarily in the inferior vena cava (IVC) during endovascular therapies for deep venous thrombosis (DVT) in the lower extremity., Purpose: To evaluate the necessity of implantation of a retrievable inferior vena cava filter during treatment of DVT in the lower extremity using various endovascular techniques., Material and Methods: Studied were all 37 consecutive sessions of endovascular treatments performed in 34 patients with symptomatic lower-limb DVT between April 2001 and October 2006. In all sessions, a Gunther tulip retrievable vena cava filter (GTF) was implanted during the procedures. The degree of trapped thrombus in the filter was evaluated by repeated venocavography., Results: Implantation of a total of 66 GTFs was successfully performed in 37 sessions. Worsening of or new formation of pulmonary embolism was avoided in all patients. In 20 (54.1%) of the 37 sessions, a trapped thrombus in the filter was observed. In 14, the trapped thrombus was large, filling more than half the height of the filter., Conclusion: Temporary implantation of filters is effective in preventing pulmonary emboli during endovascular treatment of DVT in the lower extremities.

Background: Inferior vena cava (IVC) filters are an alternative management strategy to anticoagulation in patients with venous thromboembolism (VTE). However, an IVC filter has its own inherent risks and complications and may not be the best management strategy. The aims of this study were to evaluate our institution's practice of permanent Vena Tech (B. Braun Medical S.A., Boulogne, France) and retrievable Gunther Tulip (William Cook Europe, Bjaeverskov) IVC filters and to review the available published reports., Methods: Retrospective single centre audit from the medical record., Results: Eighty-three and 42 patients had a VT and GT filter inserted, respectively. Median age was 57 years for VT and 63 years for GT. The majority (75% for VT and 83% for GT) was inserted for acute VTE and contraindication to anticoagulation. Both filters were efficacious at preventing pulmonary embolism (PE) and there was a low rate of recurrent deep venous thrombosis in both groups. Insertion-related complications were low in both groups. Of the GT filters (n = 42), 16 were deemed an ongoing requirement, and thus, removal was not planned. In a further six patients, there was insufficient documentation as to why removal was not planned. Removal was attempted in 19 patients and was successful in 11. Failure of removal was as a result of clot in the filter (n = 7) or inability to snare it (n = 1)., Conclusions: Both the permanent and retrievable filters are efficacious at preventing PE and are associated with a low complication rate. Planned removal of the GT filter may not be possible in a significant proportion of cases.

The purpose of this study was to evaluate the filtering effect of the Gunther tulip retrievable vena cava filter (GTF) during treatment of deep venous thrombosis (DVT) in the lower extremity using various interventional radiological procedures. Subjects of the study were all 17 consecutive patients (8 women, 9 men; age range 18-87 years; mean age 55.9 years) with symptomatic lower limb DVT referred for interventional radiological treatment between February 2001 and September 2004. In all of these patients, the GTF was implanted during interventional radiological treatment. Trapped thrombus in the filter was evaluated with venocavography performed repeatedly during the treatment for DVT. Implantation of a total of 29 GTFs was successfully performed in the 17 patients. In 10 (58.8%), more than 2 filters were subsequently implanted to prolong implantation time. Also in 10 patients, the DVT resolved after therapy and retrieval of the final GTF was successful with one exception. Worsening of or new formation of pulmonary embolism was avoided in all patients. In 8 (47.1%) of the 17 patients, a trapped thrombus in the GTF was observed during treatment for DVT. In six patients the trapped thrombus was large, filling more than half the height of the filter. In conclusion, we found that the GTF is effective in filtering the relieved thrombus from DVT in the lower extremity and in protecting against movement of the thrombus to the pulmonary artery during therapies with interventional radiological procedures.

The frequency of insertion of prophylactic inferior vena cava filters (IVCF) among traumatized patients has increased nationally. That has placed a substantial operational and economic burden upon trauma centers. The purpose of this study was to compare and contrast successful implantation, morbidity, and cost-effectiveness of prophylactic IVCF insertion in a surgical-trauma intensive care unit (STICU) versus an operating room (OR). A retrospective chart review was conducted of all trauma patients who received a prophylactic IVCF at an urban Level I trauma center between January 1999 and December 2003. Data were collected to identify patient demographics, indications, anatomical site of insertion, hospital location of insertion, hospital days before insertion, and complications associated with insertion. One hundred thirty-four patients underwent prophylactic IVCF during the study period: seventy-eight (58%) in the OR and fifty-six (42%) in the STICU. The average age of patients for the OR and STICU groups were 38.6 years and 39.6 years, respectively. The average number of days to IVCF insertion was 6.5 days and 7.0 days in the OR and STICU groups, respectively. Indications for IVCF among patients who had placement in the OR were orthopedic injury (60%), spinal cord injury (25%), and head injury (15%). Indications for IVCF among patients who had placement in the STICU were head injury (38%), orthopedic injuries (34%), and spinal cord injury (25%). Three (3.8%) patients in the OR group and two (3.6%) patients in the STICU group required a change of anatomic insertion site from the femoral to the internal jugular vein. There were two (2.6%) complications associated with IVCF insertion in the OR and two (3.5%) complications associated with IVCF insertion in the STICU (P > 0.05). Insertion of IVCF in the STICU decreased patient-cost by an average of dollar 1636 per patient. Prophylactic IVCF insertion in an STICU is cost-effective and can be performed with similar success and complication rates to IVCF insertion in an OR.

Vena cava filters have been in use for decades to prevent pulmonary embolization from deep venous thrombosis. These filters have been shown to be effective, with fairly low rates of filter migration, fracture and thrombosis. However considering that filters remain in situ for the life of the patient and that studies do not show increased longevity in patients with filters, any complications from filters are significant concerns. In addition, often patients require filters for only temporary indications, e.g. contraindication for anticoagulation because of impending procedures, or for only a transient risk period, as in trauma or pregnant patients. In these cases, removable filters may be more appealing. This review will examine the different types of removable filters and the indications in which removable filters may have an advantage over permanent filters.

A 63-year-old woman complained of chest pain and was referred to hospital where she was found to have left pleural effusion and swelling, local heat and edema of the right lower leg. Initial pulmonary perfusion scintigraphy demonstrated multiple defects and pulmonary thromboembolism (PTE) was confirmed during the anticoagulant and thrombolytic therapy against thrombophlebitis. A Greenfield filter was inserted in the inferior vena cava to prevent recurrence of PTE from the thrombosis that was resistant to therapy. In-111-labeled platelet scintigraphy (platelet scintigraphy) showed abnormal uptake of platelets in the chest, femoral veins and abdomen, which suggested active thrombus formation in those regions, including the filter, and a risk of recurrent PTE. Therefore, the thrombolytic therapy was terminated and the anticoagulant therapy intensified. A computed tomography (CT) scan revealed thrombus at the filter, which was markedly decreased 1 month later on platelet scintigraphy. Pulmonary ventilation and perfusion scintigraphy revealed remarkable improvement of the PTE. In this case, platelet scintigraphy complemented CT in demonstrating the activity and localization of the thrombus and can be used to evaluate the risk of recurrence during thrombolytic therapy after insertion of a filter.

Venous thromboembolism (VTE) is a common complication among patients in the intensive care unit. While anticoagulation remains standard therapy, vena caval filters are an important alternative when anticoagulation is contraindicated. To determine the safety and efficacy of vena caval filters in the treatment of VTE, a comprehensive review of the English-language medical literature was performed. Except for one randomized controlled trial, the literature supporting the use of vena caval filters consists almost exclusively of case series, which in many instances are limited by incomplete and short follow-up. While case series suggest that filters function effectively in the prevention of pulmonary embolism (2%-4% symptomatic pulmonary embolism [PE], fatal PE < 2%), recent higher quality studies indicate that filters may not provide significant additional protection to that provided by anticoagulation alone. Furthermore, filters are associated with a 2- fold increase in the incidence of recurrent DVT. Until randomized comparative studies are available, the safety and efficacy of all the available devices should be considered to be roughly equivalent. Since filters do not inhibit continued clot formation, all filter patients should receive anticoagulation for durations appropriate for their thrombotic disorder. Although extended anticoagulation may prevent thrombotic complications associated with filter placement, this strategy has yet to be experimentally tested. While many additional indications for vena caval filter use have been proposed (VTE in cancer patients, PE prophylaxis in trauma patients, etc), well-designed clinical trials demonstrating their efficacy in these situations are lacking. Further development of temporary/retrievable filters, which offer the potential to avoid the long-term complications of permanent filters, should be a research priority. Until additional data are available, vena caval filters should generally be restricted to patients with VTE who cannot receive anticoagulation.

Objective: The goal of this study was to evaluate factors affecting technical success and the immediate complications of placement of vena cava filters., Materials and Methods: The medical records of 148 consecutive patients who underwent filter placement between December 1995 and February 1999 were retrospectively reviewed for cavography, technical success, complications, and operator specialty., Results: The records of 143 filter placements in 142 patients were complete (one patient underwent two placements). One hundred twenty filter placements were preceded by cavography, and 23 were not. Three misplacements (2.5%) were preceded by cavography and 10 (43%) were not (p<0.0001). One hundred fourteen filter placements were performed by radiologists and 29 by surgeons. Cavography was performed before 98% of placements by radiologists but in only 28% of placements by surgeons (p<0.0001). Filter misplacement occurred in 12 placements (41%) by surgeons and in only one (0.9%) by radiologists (p<0.0001). Major complications occurred in three placements (10%) by surgeons and in none of the placements by radiologists (p<0.01)., Conclusion: Vena cava filters were placed with greater technical success and fewer complications when preceded by cavography. Radiologists placed filters with greater technical success and fewer complications than surgeons, which may be the result of radiologists generally having more training and more familiarity with imaging-guided procedures and adhering more to cavography protocol. A credentialing requirement for physician operators and evaluation using quality improvement standards may be advisable.

Purpose: The purpose of this study was the assessment of the safety, efficacy, and hospital charges of bedside duplex ultrasound-directed inferior vena cava (IVC) filter placement., Methods: All duplex ultrasound-directed IVC filters that were placed from August 8, 1995, to December 31, 2000, are reviewed. Chart review combined with mailed questionnaires and telephone follow-up examinations were used to collect demographic and outcome data., Results: Three hundred twenty-five patients underwent evaluation, and 284 underwent duplex ultrasound-directed IVC filter placement. Two hundred three (71%) were male patients, and 81 (29%) were female patients. Poor IVC visualization, IVC thrombosis, and unsuitable anatomy prevented duplex-directed filter placement in 41 patients (12%). Indication for filter placement included venous prophylaxis in the absence of thromboembolism in 235 patients (83%), contraindication to anticoagulation therapy in 34 patients (12%), prophylaxis with therapeutic anticoagulation therapy in the presence of thromboembolism in 7 patients (2%), and complication of anticoagulation therapy in 8 patients (3%). There were no procedure-related deaths or septic complications. Technical complications occurred in 12 patients (4%). Filter misplacement occurred in 6 patients (2%), access thrombosis in 1 (<1%), migration in 1 (<1%), bleeding in 1 (<1%), and IVC occlusion in 3 (1%). Pulmonary emboli after IVC filter placement occurred in one patient with a misplaced filter. Average hospital charges related to duplex ultrasound-directed filter placement were $2388 less than fluoroscopic placement charges in the year 2000., Conclusion: Our experience indicates that duplex ultrasound-directed IVC filter placement is safe, cost-effective, and convenient for patients who need IVC filter placement.

Purpose: To compare the five vena caval filters marketed in the United States and one investigational vena caval filter and to determine whether there is an association between their design and their in vivo function., Methods: Four of each type of filter--Simon Nitinol (SN), Bird's Nest (BN), Vena Tech (VT), Greenfield stainless steel (PSGF), Greenfield titanium (TGF), and the investigational stent cone filter (NGF)--were studied for 60 days in 12 sheep. Radiographic and pathologic outcomes to be assessed included clot capture and resolution, vena caval penetration, position of the filter, thrombogenicity, and vessel wall reaction., Results: Filters differed with respect to the number of clot-trapping levels and the interdependence of the legs. All devices were successfully placed. Intentionally embolized clot was captured. One VT and two SN filters migrated in response to clot capture. Resolution of thrombus was variable, and related to the design of the device. Fibrin webbing was widely present with the VT, BN, and SN filters but limited in the others. The VT and NGF filters demonstrated the most stable filter base diameter., Conclusions: The performance of vena caval filters differs with respect to clot resolution and mechanical stability. Interdependent filter limbs and single-stage conical capture sites appear to result in more favorable performance in in vivo studies.

We report our preliminary experience with the Bird's Nest inferior vena cava filter. Six patients, three men and three women, mean age 71 years (range 25-86), were considered for a Bird's Nest Filter during a 28-month period. Indications were contraindications to anticoagulation in two patients and insufficient effect of anticoagulant therapy in four patients. Three patients succumbed before filter placement. Two filters were placed percutaneously via the right common femoral vein and one via the left common femoral vein. All three filters were inserted successfully without complications. One patient died of multi-organ-failure 25 days after the filter insertion. Two patients are without any complaints and have normal ultrasound examinations 90 and 350 days after filter placement. It is uncommon to insert IVC filters in Denmark, we recommend that it be done by interventional radiologists.

By means of a questionnaire we studied the current indications for and the extent of the use of vena cava filters (VCF) in 325 Danish hospital departments. Two hundred and eighty (86%) responded. Only six clinical and four radiological departments (4%) used VCF. Eighteen percent did not find any indications for the use of VCF, 32% were not familiar with the method, and 46% replied that they did not have the relevant patient population. The reported indications for VCF are consistent with the international guidelines. We discussed the scientific background, indications and limitations for the use of VCF and concluded that the current use of VCF in Denmark probably is less than optimal. VCF should be considered in patients with pulmonary embolism or at high risk of pulmonary embolism when anticoagulant therapy is contraindicated.

The AA. utilized temporary vena cava filters (16 Filcard and 8 Lysofilters) in 24 patients affected by deep venous thrombosis (DVT) of the lower limbs for the prevention of primary and recurrent pulmonary embolism (PE). The diagnosis of thromboembolic disease was always achieved by means of Ultrasounds (echo-color doppler) and was punctually confirmed by a retrograde cavagram during the insertion of the device. 19 patients presented large free-floating thrombi at inferior caval, iliac or common femoral vein level whereas 5 patients presented thrombi mostly of occlusive aspect. There was clinical or scintigraphic evidence of PE in 6 of the patients enrolled. 20 patients, without contraindications, were treated by fibrinolysis (F) with Urokinase (2-10 days) whereas 4 patients underwent surgical thrombectomy (T) because of short time relation with surgical intervention or trauma. All of them were protected by temporary vena cava filters and heparinized. All the filters were removed within 10 days. The results were considered "very good" (complete regression of floating thrombi) in 16 cases (14 F + 2 T), "good" (nearly complete regression of floating thrombi) in 3 cases (2 F + 1 T) and "poor" (unchanged) in the remaining 5 cases (4 F + 1 T). We didn't observe any new case or relapse of PE in the whole group and, furtherly, in 2 cases (1 F and 1 T) we demonstrated the capture of big emboli by the filter's basket. These clots were subsequently dissolved by fibrinolysis. To achieve the diagnosis of thromboembolic disease the following methods were used: 1--Screening: echo-color doppler of lower limbs extended to iliac and inferiora cava veins for detection of DVT and echocardio-color doppler for the detection of cardiac signs of PE. 2--DIAGNOSIS: pulmonary scintigram, retrograde cavogram and, rarely, angioCT scan. 3--FOLLOW-UP: echo-color doppler of lower limbs and pulmonary scintigram. The percutaneous insertion sites were the basilic vein (Filcard) and the right jugular vein (Lysofilter). Left jugular vein was used in 1 case with a big thyroid goitre. In the present experience we had no accidents during filters introduction or removal and no thrombosis at the insertion site (1 case of phlebitis of basilic vein). Indications and effectiveness: our results seem to be favorable to the use of inferior vena cava temporary filters for primary and recurrent pulmonary embolism prevention in the cases with floating thrombi both on fibrinolysis and embolectomy. In the cases of occlusive thrombotic diseases they proved to be effective to prevent PE during surgical embolectomy.(ABSTRACT TRUNCATED AT 400 WORDS)

Seven ombrelles percutaneous cava filters, now available, are tested on hydraulic testing ground. Measurements are concerned with the blocking function of filters and pressure changes induced in the cava flow and the cava track wall of the testing ground. A statistical analysis of the results (100 measurements per filter) shows homogeneous reactions of each filter when faced with different situations imposed by variations of the testing ground. Greenfield's filter, a reference, is compared with other models. This one and the L.G. filter show satisfactory filtering qualities. Two other filters, Cardial and Vascor, offer a highest filtering power. Other models give poor filtering results.