Obstructive Shock in Acute Vena Cava Filter Thrombosis: A Rare Presentation.

Inferior vena cava (IVC) filters are commonly placed to prevent the development or worsening of pulmonary emboli. They are also inherently thrombogenic. Here we discuss a case of acute IVC filter thrombosis with the unusual presentation of obstructive shock resulting in death. A man, age 70 years, underwent laminectomy for multilevel spinal stenosis. An IVC filter was placed preoperatively for acute calf deep vein thrombosis (DVT). On postoperative day 4 he developed tachycardia, hypotension, and signs of lower extremity arterial insufficiency. No lower extremity swelling was noted. Imaging showed complete IVC occlusion caudal to the IVC filter with extension to bilateral iliofemoral veins. Arterial flow was preserved. Therapeutic heparinization was initiated and urgent percutaneous thrombectomy was performed. However, the patient developed multi-organ failure and died shortly thereafter. This report describes an uncommon etiology of obstructive shock and highlights a potentially life-threatening thrombotic complication associated with IVC filters that clinicians should be vigilant about.

Ultrasonographic assessment of the risk of free-floating thrombus detachment in the lower extremity deep veins in patients with fracture.

OBJECTIVE: To explore the ultrasonographic features and influencing factors of free-floating thrombus (FFT) detachment in the lower extremity deep veins (LEDVs) of patients with fractures. METHODS: Clinical data of patients diagnosed with FFT in the LEDVs and implanted with an inferior vena cava filter (IVCF) in our hospital between July 2021 and August 2023 were retrospectively analysed. The patients were divided into the thrombus detachment group (the experimental group, n = 92) and the non-thrombus detachment group (the control group, n = 103) based on the presence of detached thrombus in the IVCF. The effects of thrombus echogenicity, floating degree, thrombus location, thrombin time, D-dimer and fibrinogen on thrombus shedding were analysed. The nomogram method was used to establish the model and predict the probability of delayed postoperative recovery. RESULTS: The proportions of patients with extremely hypoechoic thrombus and medium and high floating degrees increased in the experimental group compared with those in the control group, and the differences between the two groups were statistically significant (P < 0.05). Extremely hypoechoic thrombus (P = 0.021, 95 % CI: 1.109-13.748) and high (P = 0.001, 95 % CI: 3.854-28.573) and medium floating degrees (P = 0.004, 95 % CI: 1.792-13.453) were risk factors for deep veins FFT (DV FFT) detachment. The results of receiver operating characteristic curve analysis showed that the area under the curve of the model was 0.893, with a 95 % CI of 0.856-0.937, indicating a high prediction accuracy. CONCLUSION: Ultrasonographic parameters, including thrombus echogenicity and floating degree, are valuable in predicting DV FFT detachment in patients with traumatic fractures, providing references for IVCF implantation.

Hydrogel coating containing heparin and cyclodextrin/paclitaxel inclusion complex for retrievable vena cava filter towards high biocompatibility and easy removal.

Aiming to improve the retrieval rate of retrievable vena cava filters (RVCF) and extend its dwelling time in vivo, a novel hydrogel coating loaded with 10 mg/mL heparin and 30 mg/mL cyclodextrin/paclitaxel (PTX) inclusion complex (IC) was prepared. The drug-release behavior in the phosphate buffer solution demonstrated both heparin and PTX could be sustainably released over approximately two weeks. Furthermore, it was shown that the hydrogel-coated RVCF (HRVCF) with 10 mg/mL heparin and 30 mg/mL PTX IC effectively extended the blood clotting time to above the detection limit and inhibited EA.hy926 and CCC-SMC-1 cells' proliferation in vitro compared to the commercially available bare RVCF. Both the HRVCF and the bare RVCF were implanted into the vena cava of sheep and retrieved at at 2nd and 4th week after implantation, revealing that the HRVCF had a significantly higher retrieval rate of 67 % than the bare RVCF (0 %) at 4th week. Comprehensive analyses, including histological, immunohistological, and immunofluorescent assessments of the explanted veins demonstrated the HRVCF exhibited anti-hyperplasia and anticoagulation properties in vivo, attributable to the hydrogel coating, thereby improving the retrieval rate in sheep. Consequently, the as-prepared HRVCF shows promising potential for clinical application to enhance the retrieval rates of RVCFs.

Numerical simulation and in vitro experimental study of the hemodynamic performance of vena cava filters with helical forms.

Inferior vena cava filter (IVCF) implantation is a common method of thrombus capture. By implanting a filter in the inferior vena cava (IVC), microemboli can be effectively blocked from entering the pulmonary circulation, thereby avoiding acute pulmonary embolism (PE). Inspired by the helical flow effect in the human arterial system, we propose a helical retrievable IVCF, which, due to the presence of a helical structure inducing a helical flow pattern of blood in the region near the IVCF, can effectively avoid the deposition of microemboli in the vicinity of the IVCF while promoting the cleavage of the captured thrombus clot. It also reduces the risk of IVCF dislodging and slipping in the vessel because its shape expands in the radial direction, allowing its distal end to fit closely to the IVC wall, and because its contact structure with the inner IVC wall is curved, increasing the contact area and reducing the risk of the vessel wall being punctured by the IVCF support structure. We used ANSYS 2023 software to conduct unidirectional fluid-structure coupling simulation of four different forms of IVCF, combined with microthrombus capture experiments in vitro, to explore the impact of these four forms of IVCF on blood flow patterns and to evaluate the risk of IVCF perforation and IVCF dislocation. It can be seen from the numerical simulation results that the helical structure does have the function of inducing blood flow to undergo helical flow dynamics, and the increase in wall shear stress (WSS) brought about by this function can improve the situation of thrombosis accumulation to a certain extent. Meanwhile, the placement of IVCF will change the flow state of blood flow and lead to the deformation of blood vessels. In in vitro experiments, we found that the density of the helical support rod is a key factor affecting the thrombus trapping efficiency, and in addition, the contact area between the IVCF and the vessel wall has a major influence on the risk of IVCF displacement.

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

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

Multidisciplinary Approach to Pulmonary Embolism and the Role of the Pulmonary Embolism Response Team.

PURPOSE OF REVIEW: Acute pulmonary embolism (PE) is a leading cause of cardiovascular death and morbidity, and presents a major burden to healthcare systems. The field has seen rapid growth with development of innovative clot reduction technologies, as well as ongoing multicenter trials that may completely revolutionize care of PE patients. However, current paucity of robust clinical trials and guidelines often leave individual physicians managing patients with acute PE in a dilemma. RECENT FINDINGS: The pulmonary embolism response team (PERT) was developed as a platform to rapidly engage multiple specialists to deliver evidence-based, organized and efficient care and help address some of the gaps in knowledge. Several centers investigating outcomes following implementation of PERT have demonstrated shorter hospital and intensive-care unit stays, lower use of inferior vena cava filters, and in some instances improved mortality. Since the advent of PERT, early findings demonstrate promise with improved outcomes after implementation of PERT. Incorporation of artificial intelligence (AI) into PERT has also shown promise with more streamlined care and reducing response times. Further clinical trials are needed to examine the impact of PERT model on care delivery and clinical outcomes.

Predicting inferior vena cava filter complications using machine learning.

OBJECTIVE: Inferior vena cava (IVC) filter placement is associated with important long-term complications. Predictive models for filter-related complications may help guide clinical decision-making but remain limited. We developed machine learning (ML) algorithms that predict 1-year IVC filter complications using preoperative data. METHODS: The Vascular Quality Initiative database was used to identify patients who underwent IVC filter placement between 2013 and 2024. We identified 77 preoperative demographic and clinical features from the index hospitalization when the filter was placed. The primary outcome was 1-year filter-related complications (composite of filter thrombosis, migration, angulation, fracture, and embolization or fragmentation, vein perforation, new caval or iliac vein thrombosis, new pulmonary embolism, access site thrombosis, or failed retrieval). The data were divided into training (70%) and test (30%) sets. Six ML models were trained using preoperative features with 10-fold cross-validation (Extreme Gradient Boosting, random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was assessed using calibration plot and Brier score. Performance was evaluated across subgroups based on age, sex, race, ethnicity, rurality, median Area Deprivation Index, planned duration of filter, landing site of filter, and presence of prior IVC filter placement. RESULTS: Overall, 14,476 patients underwent IVC filter placement and 584 (4.0%) experienced 1-year filter-related complications. Patients with a primary outcome were younger (59.3 ± 16.7 years vs 63.8 ± 16.0 years; P < .001) and more likely to have thrombotic risk factors including thrombophilia, prior venous thromboembolism (VTE), and family history of VTE. The best prediction model was Extreme Gradient Boosting, achieving an AUROC of 0.93 (95% confidence interval, 0.92-0.94). In comparison, logistic regression had an AUROC of 0.63 (95% confidence interval, 0.61-0.65). Calibration plot showed good agreement between predicted/observed event probabilities with a Brier score of 0.07. The top 10 predictors of 1-year filter-related complications were (1) thrombophilia, (2) prior VTE, (3) antiphospholipid antibodies, (4) factor V Leiden mutation, (5) family history of VTE, (6) planned duration of IVC filter (temporary), (7) unable to maintain therapeutic anticoagulation, (8) malignancy, (9) recent or active bleeding, and (10) age. Model performance remained robust across all subgroups. CONCLUSIONS: We developed ML models that can accurately predict 1-year IVC filter complications, performing better than logistic regression. These algorithms have potential to guide patient selection for filter placement, counselling, perioperative management, and follow-up to mitigate filter-related complications and improve outcomes.

The Inferior Vena Cava Filter Placement Parameters May Predict Filter Retrieval Outcomes.

BACKGROUND: We aimed to investigate the potential correlation between the placement factors of various retrievable inferior vena cava filters and retrieval outcomes. Additionally, we aimed to identify the factors affecting the placement tilt of the filter. METHODS: This retrospective study was conducted at a tertiary care center to investigate patients who had previously undergone retrievable filter placement at our center and who subsequently had their filters removed between January 2020 and December 2021. Patient characteristics and filter-related factors were recorded. Complex filter retrieval was defined as cases that required a minimum of 8 minutes of fluoroscopy or that involved advanced techniques. Regression models were used to explore patient- and placement procedure-related factors that could influence retrieval outcomes and the placement tilt angle. RESULTS: The study included 163 patients, and all filters were successfully retrieved. Thirty-seven (22.7%) retrievals were classified as complex retrievals. The mean diameter of the inferior vena cava in the preplacement position for the entire cohort was 16 ± 1.8 mm. The median filter tilt angles at placement and retrieval were 5.0° (IQR, 1.8°-9°) and 4.6° (IQR, 2.1°-8.0°), respectively. The placement tilt angle was not significantly associated with complex retrieval (P = 0.59). The filter hook abutment to the vena cava wall (OR, 10.76, P = 0.003), dwell time (OR, 1.02, P = 0.029), and diameter of the vena cava (OR, 10.21, P < 0.001) were associated with complex retrieval. The diameter (P = 0.049), age (P = 0.049), and filter brand (P = 0.001) were found to be significantly associated with placement tilt. CONCLUSIONS: The inferior vena cava diameter at the time of placement predicts difficulty in filter retrieval. In addition, the filter hook abutting the inferior vena cava wall and long indwelling time may complicate retrieval. The vena cava diameter is also closely related to the degree of filter tilt.

Inferior vena cava filter thromboprophylaxis in surgical cancer patients.

BACKGROUND AND OBJECTIVES: This study evaluated the utilization and outcomes of inferior vena cava (IVC) filters as thromboprophylaxis in cancer patients undergoing surgery. METHODS: This single-center retrospective study analyzed baseline patient characteristics and clinical outcomes of surgical cancer patients who received perioperative prophylactic IVC filters. Primary clinical endpoints included venous thromboembolism (VTE) incidence and filter complications. A statistical correlative analysis was conducted to identify risk factors related to pulmonary embolism (PE), deep vein thrombosis (DVT), and filter thrombi, as well as advanced technique filter removal and mortality at 6 months. RESULTS: A total of 252 surgical oncology patients (median age, 59; female 51%) received IVC filters for the perioperative prevention of PE. Primary surgical sites included spine (n = 91, 36%), orthopedic extremity/joint (n = 49, 19%), genitourinary (n = 47, 19%), brain/cranial (n = 40, 16%), abdominal (n = 18, 7%), multisite (n = 4, 2%), and chest (n = 3, 1%). Moreover, 15% of patients experienced DVTs in the postplacement preretrieval period, while 2% (n = 6) of patients experienced definitive PEs. A total of 36% of IVC filters were ultimately retrieved, with an average filter dwell time of 7.4 months. Complications occurred in one retrieval. CONCLUSION: Prophylactic perioperative IVC filters in surgical cancer patients resulted in minimal complications while ultimately resulting in a low incidence of PE.

Fifteen-Year Trend in Inferior Vena Cava Filter Utilization before and after U.S. Food and Drug Administration Communications: Data from the National Inpatient Sample 2005-2019.

The purpose of this study was to evaluate the contemporary trends in inferior vena cava (IVC) filter utilization in the inpatient setting following the U.S. Food and Drug Administration (FDA) safety communications and compare those trends in relation to incidence of hospital admissions involving venous thromboembolism (VTE). The National Inpatient Sample was queried between 2005 and 2019. There was an increasing trend in the utilization of IVC filters between 2005 and 2010 (P < .01). Following the FDA communication in 2010, this reversed to a decreasing trend (P < .001), which persisted following the second FDA communication in 2014, although there was no significant change in the rate of decline (P = .67). Throughout the study period, the proportion of IVC filters placed in patients with VTE increased from 70.8% to 82.2%.

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.

Management options for pediatric venous thromboembolic disease: Beyond anticoagulation with endovascular therapies.

Venous thromboembolism (VTE) in pediatric patients is an uncommon but serious diagnosis that has an array of therapeutic options and challenges. An assessment of the existing literature on management of pediatric patients with VTE was conducted. The interventions reviewed include anticoagulation, thrombolysis, thrombectomy, inferior vena cava (IVC) filters, and venous stenting. For each intervention, a discussion of mechanism of action, indications, contraindications, and potential complications was performed. While anticoagulants are considered the first-line pediatric VTE treatment, many drugs remain investigational in this patient population and treatment recommendations are extrapolated from adult practice. Thrombolysis may be indicated in cases of acute thrombosis requiring more rapid clot resolution but presents a greater bleeding risk than anticoagulation. Similarly, thrombectomy also provides rapid clot resolution and offers a larger therapeutic window and usage in more mature thrombi than thrombolysis. In select patient groups, IVC filters may be indicated in the prevention of PE but present with inherent thrombogenicity and risk of migration. The data regarding pediatric VTE treatment options, monitoring, and long term outcomes is limited compared to the adult population. The relatively few clinical trials including pediatric patients have a relatively small sample size and are heterogenous with regards to predisposing factors that further exacerbate generalizability. Additional research is needed to help construct and evaluate a robust treatment algorithm for pediatric patients with VTE.

Oral Rivaroxaban Versus Warfarin After inferior Vena cava Filter Implantation: A Retrospective Cohort Study.

OBJECTIVES: To assess the efficacy and safety of rivaroxaban compared to warfarin after inferior vena cava (IVC) filter implantation. METHOD: This retrospective analysis includes data from 100 patients with deep vein thrombosis (DVT) who underwent IVC filter implantation due to a free-floating thrombus (n = 64), thrombus propagation (n = 8), or acute bleeding (n = 8) on therapeutic anticoagulation, catheter-directed thrombolysis (n = 8), or had previously implanted filter with DVT recurrence. Patients were treated with warfarin (n = 41) or rivaroxaban (n = 59) for 3-12 months. Symptomatic venous thromboembolism (VTE) recurrence and bleeding events were assessed at 12 months follow-up. RESULTS: Three (7.3%) cases of VTE recurrence without IVC filter occlusion occurred on warfarin and none on rivaroxaban. The only (2.4%) major bleeding occurred on warfarin. Three (5.1%) clinically relevant non-major bleedings were detected on rivaroxaban. No significant differences existed between groups when full and propensity scores matched datasets were compared. CONCLUSIONS: Rivaroxaban seems not less effective and safe than warfarin after IVC filter implantation.

Inferior Vena Cava Filters: An Overview.

For patients with existing venous thromboembolisms (VTEs), anticoagulation remains the standard of care recommended across multiple professional organizations. However, for patients who developed a deep venous thrombosis (DVT) and/or a pulmonary embolism and cannot tolerate anticoagulation, inferior vena cava (IVC) filters must be considered among other alternative treatments. Although placement of a filter is considered a low-risk intervention, there are important factors and techniques that surgeons and interventionalists should be aware of and prepared to discuss. This overview covers the basics regarding the history of filters, indications for placement, associated risks, and techniques for difficult removal.

Inferior vena cava filters: Concept review and summary of current guidelines.

Anticoagulation is the first-line approach in the prevention and treatment of pulmonary embolism. In some instances, however, anticoagulation fails, or cannot be administered due to a high risk of bleeding. Inferior vena cava filters are metal alloy devices that mechanically trap emboli from the deep leg veins halting their transit to the pulmonary circulation, thus providing a mechanical alternative to anticoagulation in such conditions. The Greenfield filter was developed in 1973 and was later perfected to a model that could be inserted percutaneously. Since then, this model has been the reference standard. The current class I indication for this device includes absolute contraindication to anticoagulants in the presence of acute thromboembolism and recurrent thromboembolism despite adequate therapy. Additional indications have been more recently proposed, due to the development of removable filters and of progressively less invasive techniques. Although the use of inferior vena cava filters has solid theoretical advantages, clinical efficacy and adverse event profile are still unclear. This review analyzes the most important studies related to such devices, open issues, and current guideline recommendations.