Retrievable Vena Cava Filters Research Articles

Characterization and risk factors of inferior vena cava thrombosis in situ detected by computed tomography venography following filter placement: A single-center retrospective cohort study

ObjectiveThis study aimed to characterize radiographic characteristics on computed tomography venography and risk factors of inferior vena cava thrombosis (IVCT) in situ after retrievable vena cava filter (VCF) placement. MethodsBetween September 2018 and June 2023, a single-center retrospective cohort study was conducted in patients with or without IVCT in situ following VCF placement. Patient baseline demographics, presentation of lower extremity deep vein thrombosis (LEDVT), thrombus characteristics, concurrent pulmonary embolism, comorbidities and risk factors for LEDVT, and IVC and VCF-related information were collected and analysed. Univariable analysis followed by multivariable analysis was performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI). ResultsOne hundred and seventeen eligible patients were included, regionally isolated filling-defect surrounding the support pillars of VCF and contacting IVC wall on computed tomography venography images were identified, clots were more frequently found on the minor axis or anterior wall of IVC. Univariable analyses suggested that the incidence of IVCT in situ (31.6%, 37/117) was closely associated with age (P = .001), thrombus limb (left (P = .001) and bilateral side (P = .001)), hypertension (P = .008), filter shapes (P < .001), short IVC diameter (P = .009) or magnification percentage (P = .004), and long IVC diameter (P = .006). Multivariable analyses suggested that bilateral side LEDVT (OR, 4.92; 95% CI, 1.56-15.51; P = .007) and increased short IVC magnification percentage (OR, 1.01; 95% CI, 1.00-1.03; P = .013) statistically significant increase the IVCT in situ risk, whereas increased age (OR, 0.96; 95% CI, 0.94-0.99; P = .013) and short IVC diameter (OR, 0.87; 95% CI, 0.77-0.98; P = .026) were associated with decreased odds against IVCT in situ. ConclusionsIVCT in situ represents regionally isolated filling-defect at points of filter contact with IVC wall. Bilateral side LEDVT and increased short IVC magnification percentage may be potential risk factors impacting the occurrence of IVCT in situ, while increased age and short IVC diameter may decrease the incidence of IVCT in situ and seem to be protective factor against IVCT in situ emergence.

Numerical simulation and in vitro experimental study of thrombus capture efficiency of a new retrievable vena cava filter

The vena cava filter is a filtering device to prevent pulmonary embolism caused by thrombosis from lower limbs and pelvis. A new retrievable vena cava filter was evaluated in this paper. To evaluate the hemodynamic performance and thrombus capture efficiency after transplantation, numerical simulation of computational fluid dynamics was performed. In this paper, the two-phase flow model of computational fluid dynamics software was used to analyze the outlet blood flow velocity, inlet-outlet pressure difference, filter wall shear stress, the ratio of area with wall shear stress, and the thrombus capture efficiency with the thrombus diameter of 5 mm, 10 mm, 15 mm and the thrombus content of 10%, 20%, 30%, respectively. Additionally, in vitro experimental test was performed to compare its thrombus capture efficiency with Denali and Aegisy Filters. The Denali Filter showed the least interference with the blood flow, followed by the new filter and the Aegisy Filter. The results indicated that the new filter had a higher capture rate in capturing 5mm small-diameter thrombus. This research certain theoretical significance and reference value for the research and development of the new vena cava filters as well as the evaluation of the thrombus capture efficiency of the filters.

Long-term outcomes after using retrievable vena cava filters in major trauma patients with contraindications to prophylactic anticoagulation

PurposeTo investigate the long-term outcomes of using vena cava filters to prevent symptomatic pulmonary embolism (PE) in major trauma patients who have contraindications to prophylactic anticoagulation.MethodsThis was an a priori sub-study of a randomized controlled trial (RCT) involving long-term outcome data of 223 patients who were enrolled in Western Australia. State-wide clinical information system, radiology database and death registry were used to assess long-term outcomes, including incidences of venous thromboembolism, venous injury and mortality beyond day-90 follow-up.ResultsThe median follow-up time of 198 patients (89%) who survived beyond 90 days was 65 months (interquartile range 59–73). Ten patients (5.1%) died after day-90 follow-up; and four patients developed venous thromboembolism, including two with symptomatic PE, all allocated to the control group (0 vs 4%, p = 0.043). Inferior vena cava injuries were not recorded in any patients. The mean total hospitalization cost, including the costs of the filter and its insertion and removal, to prevent one short- or long-term symptomatic PE was A$284,820 (€193,678) when all enrolled patients were considered. The number of patients needed to treat (NNT = 5) and total hospitalization cost to prevent one symptomatic PE (A$1,205 or €820) were, however, substantially lower when the filter was used only for patients who could not be anticoagulated within seven days of injury.ConclusionLong-term complications related to retrievable filters were rare, and the cost of using filters to prevent symptomatic PE was acceptable when restricted to those who could not be anticoagulated within seven days of severe injury.

STUDY ON THE NONLINEAR DEFORMATION MECHANICAL PROPERTIES OF A NEW TYPE OF VENA CAVA FILTER

In order to analyze the mechanical properties of a new type of retrievable vena cava filter, the Denali and Aeginsy retrievable filters are selected, and the in vivo and in vitro mechanical properties of the three types of retrievable vena cava filters are compared. The nonlinear deformation process of the filter which is pressed into the transport sheath, flicked and released into the vascular vessel is simulated by using the finite element method, and the mechanical behaviors of the filter and the blood vessel wall are analyzed. During the crimping process, the elastic strain peak value of the filter wall increases with increasing amount of grip. The maximum elastic strain peak value of the three filters is less than 8%, and the safety factor is greater than 2, which meets the strength requirement. Equivalent stress and strain on the vascular wall decreases along the direction of blood flow after the filter is opened. The peak value of equivalent stress and strain on the vascular wall corresponding to Aegisy filter is the largest, and the impact on the vascular wall is the largest. The total displacement of the three filters under the action of thrombus and blood fluids is not more than 80[Formula: see text][Formula: see text]m. The impact of the new filter on the vascular wall is smaller than that of Aegisy filter, and the total displacement after implantation is smaller than that of Denali filter. The results are valuable for the evaluation and clinical application of the new vena cava filter.

Anti-coagulation and anti-hyperplasia coating for retrievable vena cava filters by electrospraying and their performance in vivo

A novel drug eluting retrievable vena cava filter (RVCF) with a heparin-modified poly(ε-caprolactone) (hPCL) coating containing rapamycin was prepared by electrospraying. The in vitro drug release pattern showed that the encapsulated rapamycin in the coating can be sustainably released within one month, whereas activated partial thromboplastin time (APTT) and in vitro cell culture showed that the drug eluting RVCF can effectively extend blood clotting time and inhibit smooth muscle cell (SMC) and endothelial cell (EC) proliferation, respectively. The as-prepared drug eluting RVCF and corresponding commercial RVCF were implanted into the vena cava of sheep. The retrieval operation at a predetermined time point showed that the drug eluting RVCF had a much higher retrieval rate than the commercial RVCF. Comprehensive investigations, including histological, immunohistological and immunofluorescence analyses, on explanted veins were carried out. The results demonstrated that the as-prepared RVCF possessed excellent antihyperplasia properties in vivo, significantly improving the retrieval rate and extending the in vivo dwelling time in sheep. Consequently, the drug eluting RVCF has promising potential for application in the clinic to improve RVCF retrieval rates.

Biopsy Forceps-Assisted Loop Snare Technique for Complex Retrieval of Inferior Vena Cava Filter.

Severe tilt with embedded hooks is a common obstacle to successful inferior vena cava (IVC) filter retrieval. Disposal biopsy forceps were used to remodel the filter hook in the center position to release the embedded hook from the caval wall. The biopsy forceps-assisted loop snare technique was successfully used to retrieve filters with hooks embedded in the IVC wall. The biopsy forceps-assisted loop snare technique we present here offers a new solution for the complex retrieval of IVC filters. This technique may prove useful in cases where standard techniques at filter retrieval fail.

Feasibility study of hand-carried ultrasound-guided retrievable inferior vena cava filter placement

BackgroundWith the development of ultrasonic diagnostic techniques in recent years, ultrasound-guided placement of inferior vena cava (IVC) filters has been widely used in clinics, and satisfactory results have been achieved. Our study aims to observe the accuracy of hand-carried ultrasound-guided retrievable vena cava filter placement, evaluate the feasibility and safety of this new method, and provide a scientific and effective interventional method and clinical data to prevent acute pulmonary embolism (PE) after battle injury of limbs.MethodsTwo hundred patients with post-traumatic thrombosis of the extremities were enrolled. The renal vein was located under the guidance of hand-carried ultrasound. The retrievable filter was fixed 1–2 cm below the opening of the renal vein. The self-expanding filter was used after the filter’s position was confirmed by injecting the contrast agent under the digital subtraction angiography (DSA) fluoroscopy.ResultsAll the 200 patients underwent the operation successfully. The position of the hand-carried ultrasound localizer was consistent with the DSA localizer. All the filters were expanded smoothly. No complications related to the operation occurred.ConclusionsThe study concluded that the hand-carried ultrasound-guided retrievable vena cava filter placement has a high success rate and can prevent acute PE after limbs’ battle injury.

Inferior Vena Cava Filter Retrieval Trends: A Single-Center Experience.

Recognition of the adverse events of inferior vena cava filters (VCFs) has prompted the Food and Drug Administration (FDA) to issue safety warnings (2010 and 2014), advocating for removal, once the risk of pulmonary embolism has abated. Despite an initial increase in retrieval rates, these remain low (25–30% at 1 year in 2014). We retrospectively investigated retrieval trends in adults with VCFs placed between 2015 and 2018 at a single institution. The rate of retrievable VCF removal accounting for the competing risk of death was the main outcome. There were 494 VCFs placed (305 retrievable). The cumulative incidence of retrieval remained low (21% at 1 year), even after the second FDA warning (2014). Patients who resumed anticoagulation (AC) at any time were more likely to have retrieval (hazard ratio [HR] = 3.6, p  < 0.01) and had higher retrieval rates at every time point (31.4 vs. 7.6% at 1 year). Advanced age (HR = 0.98 per year, p  = 0.004), stroke (HR = 0.28, p  = 0.028), and active malignancy (HR = 0.42, p  = 0.006) predicted nonretrieval. Device-related complications were infrequent (<1%) but thrombotic complications occurred early and were more common for nonretrieved VCFs (17 vs. 12%, p  = 0.29). Revision of guidelines to recommend active surveillance for the ability to tolerate AC in the immediate postimplantation period may improve retrieval rates.

Ten Years’ Experience in Vena Cava Filter Placement – Sample Characterization and Long-term Follow-up

Introduction: Vena cava filter (VCF) has been widely used since it was introduced in 1967. However, there is a general lack of information regarding VCF holders characteristics and their long-term outcomes, and there is not a standardized clinical or imagiological follow-up of these patients. Methods: This is a retrospective analysis of patients who had a VCF placed from 2008 to 2018 at Santa Marta Hospital (Lisbon, PT). Variables collected were patient demographics, indication for filter, filter used. Primary end-point was global survival. Secondary end-point was filter related complications. A substudy was performed to determine late filter related complications in alive patients by abdominal venous duplex ultrasound and abdominal x-ray. Cumulative rates of events were determined by Kaplan-Meier method. Results: From 2008 to 2018, 124 patients underwent VCF placement. Male:female ratio was 1:1. 104 patients (84%) had active venous thromboembolic event (VTE) at time of VCF placement. The most prevalent VTE risk factors were: previous documented VTE (38; 31%), recent hospitalization (63; 51%) and active neoplasm (46; 37%). The most common indications for VCF placement were: anticoagulant contraindication (69; 56%) and persisting pulmonary embolism (PE) despite anticoagulation (29; 23%). Excluding patients whose access site was not specified (16), femoral vein was punctured in 96 patients (89%) and internal jugular vein in 12 patients (11%). VCF was placed on infrarrenal inferior vena cava (IVC) in 100% of patients. Excluding patients whose filter type was not specified, permanent filter was placed in 66 patients (80%). VenaTech LP (B-Braun®) was placed in 34 patients and TrapEase (Cordis®) in 17 patients. A retrievable filter was placed in 17 patients (20%). Celect (Cook®) was placed in 2 patients and OptEase (Cordis®) in 15 patients. There was a VCF retrieval trial in 5 patients, three with success. Survival rate was 86.0±3.2% at 1 month, 63.3±4.5% at 1 year and 55.4±4.8% at 5 years. We found no PE events or VCF related-mortality during follow-up. Patients with active cancer had lower survival rates (28.7±8.5% at 5 years; p<0.001). Survival rates were similar regardless other VTE risk factors and filter indication or type. At present time of our substudy, 32 alive patients were evaluated at median time of 58 months after VCF placement. 2 patients had lower limb DVT in the meantime, one of which have active and the other previous colorrectal cancer. There were no signs of PE. 18 patients (56%) are anticoagulated, 10 with a DOAC (56%). We documented 5 asymptomatic VCF complications: 2 filter occlusions (with patent IVC proximal and distal to VCF), 3 filter tilts (one in a patient that underwent a trial of VCF retrieval). There was no documented filter fracture, penetration or migration. Conclusion: Main absolute indications for VCF placement continue to be VTE in presence of contraindication for anticoagulation and persisting PE despite anticoagulation. Persistent VTE and risk factors for recurrence, lack of follow-up and reported complications of filter retrieval may account for increased use of permanent VCF and retrievable VCF left permanently in place. In spite of known long-term adverse events of VCF (migration, fracture, tilt, penetration, thrombosis), their low incidence and absence of related symptoms challenge a standard of care follow-up for VCF holders. Very low survival rates of VCF holders who have active neoplasm challenge the benefits of VCF placement in patients with dismal prognosis.

[Hemodynamic analysis of a new retrievable vena cava filter].

Vena cava filter is a filter device designed to prevent pulmonary embolism caused by thrombus detached from lower limbs and pelvis. A new retrievable vena cava filter was designed in this study. To evaluate hemodynamic performance and thrombus capture efficiency after transplanting vena cava filter, numerical simulation of computational fluid dynamics was used to simulate hemodynamics and compare it with the commercialized Denali and Aegisy filters, and in vitro experimental test was performed to compare the thrombus capture effect. In this paper, the two-phase flow model of computational fluid dynamics software was used to analyze the outlet blood flow velocity, inlet-outlet pressure difference, wall shear stress on the wall of the filter, the area ratio of the high and low wall shear stress area and thrombus capture efficiency when the thrombus diameter was 5 mm, 10 mm, 15 mm and thrombus content was 10%, 20%, 30%, respectively. Meanwhile, the thrombus capture effects of the above three filters were also compared and evaluated by in vitro experimental data. The results showed that the Denali filter has minimal interference to blood flow after implantation, but has the worst capture effect on 5 mm small diameter thrombus; the Aegisy filter has the best effect on the trapping of thrombus with different diameters and concentrations, but the low wall shear stress area ratio is the largest; the new filter designed in this study has a good filtering and capture efficiency on small-diameter thrombus, and the area ratio of low wall shear stress which is prone to thrombosis is small. The low wall shear stress area of the Denali and Aegisy filters is relatively large, and the risk of thrombosis is high. Based on the above results, it is expected that the new vena cava filter designed in this paper can provide a reference for the design and clinical selection of new filters.

INFERIOR VENA CAVA FILTER CLINIC AND HOSPITAL REGISTRY: ONE YEAR REVIEW

Retrievable inferior vena cava (IVC) filter use has increased over 115% since the Food and Drug Administration (FDA) approval in 2009. Likewise, there has been a marked increase in complications related to their increased use. In 2014 the FDA, recognizing both the high rate of new complications and

Nuclear Factor-κB is Activated in Filter-Implanted Vena Cava.

Implantation of a retrievable vena cava filter (VCF) is an effective method for preventing pulmonary embolism. Retrieval of filters, however, may be difficult due to intimal hyperplasia and inflammation in the cava wall. The transcription factor nuclear factor-kappaB (NF-κB) plays an important role in regulation of numerous genes participating in the inflammatory and proliferative responses of cells. The present study was to determine whether VCF implantation resulted in activation of NF-κB in the venous neointima. Filters were placed in vena cava (VC) in four swine for 30days and then removed. Intimal specimens adhering to the filter struts were analyzed with reference to normal VC tissues. Immunohistochemical analyses were used to assess the NF-κB subunits p65 and p50 and the phosphorylated inhibitor of κB-α (phosphor-IκB-α) in the tissues. NF-κB DNA-binding activity was measured with enzyme-linked immunosorbent assay. As compared to normal VC tissues, the intimal tissues contained higher percentages of cell nucleus-located p65 and p50, and NF-κB DNA-binding activity. Elevated immunoreactivities of p65, p50 and phosphor-IκB-α were also present in the intima. The present study demonstrates for the first time that VCF implantation caused NF-κB activation in neointima. We further demonstrate the activation is at least partly due to phosphorylation of IκB-α. Our data suggest that NF-κB activation would significantly contribute to development of intimal hyperplasia and inflammation in filter-inserted vena cava walls. NF-κB might be a therapeutic target for inhibiting filter-induced neointima and improving filter retrieval.

Comparison of Biomechanical Properties and Hemodynamics of Three Different Vena Cava Filters

The interaction mechanism of three types of vena cava filters (VCFs) with blood vessels and their influence on the bloodstream during the process of implantation are investigated by finite element method and computational fluid dynamics. The VCF models are set up with Solidworks software. Using ABAQUS software, we simulate the working conditions of the VCFs in the vessel to analyze the stress distribution and radial support stiffness of the vessel wall and the filter surface. Using FLUENT software, we simulate and analyze the velocity, pressure and shear stress distributions of blood flow when the VCFs are at their working conditions. For the retrievable VCF (R-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the lowest. For the permanent VCF (P-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the highest. Because of the structure of scaffolding support units and the tendency to form intimal hyperplasia on their support units, both the convertible VCF (C-VCF) and the P-VCF can embed their support units in the hyperplasia skin. This effectively prevents them from harming blood veins through filter damage at the pulse load conditions. As the biomechanical property of the C-VCF is between those of the R-VCF and the P-VCF, it has smaller obstacle to blood flow after conversion and has some fragmentation effects on the thrombus. The results show that different types of VCFs differ in their biomechanical and hemodynamic properties after implantation. Therefore, the simulative analysis can provide a reference basis for filter design and clinical decision making.

Statewide Inferior Vena Cava Filter Placement, Complications, and Retrievals: Epidemiology and Recent Trends

Background:Public awareness of inferior vena cava (IVC) filter-related controversies has been elevated by the Food and Drug Administration (FDA) safety communication in 2010.Objectives:To examine population level trends in IVC filter utilization, complications, retrieval rates, and subsequent pulmon

Opting out scheme on attempted retrieval of temporary inferior vena cava filters

Opting out scheme on attempted retrieval of temporary inferior vena cava filters

Retrievable vena cava filters to protect from venous thromboembolism: do not overuse them, and do not forget to retrieve them!

Venous thromboembolism (VTE), clinically presenting as deep vein thrombosis (DVT) with or without pulmonary embolism (PE), is globally the third most frequent acute cardiovascular syndrome behind myocardial infarction and stroke (1,2).

Are there any risk factors for developing complications with the use of retrievable vena cava filters in orthopaedic surgery?

In high-risk patients, common prophylaxis may be insufficient to prevent thromboembolic events after orthopaedic procedures. In this scenario, a retrievable vena cava filter (VCF) could be considered as an alternative, although it's use remains controversial. Therefore, we asked: (1) what is the overall mechanical complication rate associated with the use of retrievable VCFs in orthopaedic surgery?, (2) what is the association with thromboembolic disease (TED) recurrence, post-thrombotic syndrome and/or major bleeding according to different surgical characteristics?, (3) What is the overall mortality rate attributed to VCF use? We retrospectively analyzed a cohort of 68 patients who underwent orthopaedic surgery with a previous diagnosis of TED, in whom a retrievable VCF was placed. Permanent filters were excluded. We studied the filter's mechanical complications and considered as possible outcomes death and 3 hematologic complications: TED recurrence, post-thrombotic syndrome and major bleeding. To estimate association with risk factors, we subclassified surgeries into 5 groups: 1, arthroplasty/non-arthroplasty; 2, primary/revision; 3, elective/urgent; 4, oncologic/non-oncologic; 5, preoperative/postoperative filter. Mechanical complications were 16% and required a filter revision. Sixty-four percent of the revised VCFs developed a mechanical failure and could not be retrieved. Overall prevalence of TED recurrence, post-thrombotic syndrome and hemorrhage was 33%, 15% and 4.5%, respectively. Spinal surgeries were a risk factor for developing TED recurrences. Only 4% of patients died of a TED recurrence. Orthopaedic procedures had a high risk of mechanical and hematologic complications after using a retrievable VCF. However, mortality was low due to these complications.

Success in Optional Vena Cava Filter Retrieval. An Analysis of 246 Patients

ObjectiveThis study assessed vena cava filter (VCF) retrieval rates and factors associated with retrieval failure in a single center cohort. MethodsWe conducted an observational retrospective cohort study. The primary endpoint was the percentage of patients whose VCF was retrieved. We performed logistic regression to identify variables associated with retrieval failure. ResultsDuring the study period, 246 patients received a VCF and met the eligibility requirements to be included in the study; 151 (61%) patients received a VCF due to contraindication to anticoagulation, 69 (28%) patients had venous thromboembolism (VTE) and a high risk of recurrence, and 26 (11%) patients received a filter due to recurrent VTE while on anticoagulant therapy. Of 236 patients who survived the first month after diagnosis of VTE, VCF was retrieved in 96%. Retrieval rates were significantly lower for patients with recurrent VTE while on anticoagulation, compared with patients with contraindication to anticoagulation or patients with a high risk of recurrence (79% vs 97% vs 100%, respectively; P<0.01). Mean time to retrieval attempt was significantly associated with retrieval failure (137.8±65.3 vs 46.3±123.1 days, P<0.001). ConclusionsIn this single center study, VCF retrieval success was 96%. A delay in the attempt to retrieve the VCF correlated significantly with retrieval failure.

Non-retrieval of\xa0inferior vena cava filters as a patient safety concern: evaluation of a new process improvement project to increase retrieval rates in a vascular and interventional radiology clinic

BackgroundRetrieval of inferior vena cava filters (IVCFs) is important to decrease the long-term risk of complications associated with indwelling devices. Our hospital experienced low retrieval rates and implemented a low-cost intervention and evaluation for quality improvement. The working hypothesis was that a simple, mailed letter intervention could increase retrieval rates by increasing patient and primary care provider knowledge of the need for retrieval.MethodsFor all prospective patients who received a retrievable IVCF during the intervention period from January 1, 2014 to February 29, 2016, patients and their primary care providers were mailed letters encouraging contact with the clinic for evaluation of eligibility for retrieval. The main outcome was retrieval of the IVCF if clinically indicated with a secondary outcome of time-to-retrieval. A pre-intervention control group from October 1, 2011 to December 31, 2013 was used to evaluate the impact of the intervention. Competing risks, time-to-event analysis was used to compare the pre- and post-intervention period retrieval rates correcting for patients who died during follow-up.ResultsBetween the pre- and post-intervention periods, crude retrieval rates increased from 4.4% to 8.1% with a 12-fold change at comparable time points. The time-to-retrieval in the pre-intervention period was a mean (SD) of 503 (207) days with a median (IQR) of 505 (301–742). In the post-intervention period, time-to-retrieval was a mean (SD) of 119 (83) days and with median (IQR) of 128 (38–164) days.ConclusionsThis low-cost intervention significantly increased retrieval rates in a single clinic. However, retrieval rates remain low and can be further improved. Ongoing interventions, including improved patient follow-up and physician education, are being implemented to further improve retrieval and use of inferior vena cava filters. Implanting clinics should implement quality improvement initiatives to improve patient care and follow-up with IVCFs to ensure retrievals occur once clinically relevant in order to minimize long-term complications.

Éxito en la recuperación de filtro de vena cava inferior opcional: Análisis de 246 pacientes

ObjectiveThis study assessed vena cava filter (VCF) retrieval rates and factors associated with retrieval failure in a single center cohort. MethodsWe conducted an observational retrospective cohort study. The primary endpoint was the percentage of patients whose VCF was retrieved. We performed logistic regression to identify variables associated with retrieval failure. ResultsDuring the study period, 246 patients received a VCF and met the eligibility requirements to be included in the study; 151 (61%) patients received a VCF due to contraindication to anticoagulation, 69 (28%) patients had venous thromboembolism (VTE) and a high risk of recurrence, and 26 (11%) patients received a filter due to recurrent VTE while on anticoagulant therapy. Of 236 patients who survived the first month after diagnosis of VTE, VCF was retrieved in 96%. Retrieval rates were significantly lower for patients with recurrent VTE while on anticoagulation, compared with patients with contraindication to anticoagulation or patients with a high risk of recurrence (79% vs. 97% vs. 100%, respectively; P<0.01). Mean time to retrieval attempt was significantly associated with retrieval failure (137.8 ± 65.3 vs. 46.3 ± 123.1 days, P<0.001). ConclusionsIn this single center study, VCF retrieval success was 96%. A delay in the attempt to retrieve the VCF correlated significantly with retrieval failure.