British Society of Interventional Radiology (BSIR) Inferior Vena Cava (IVC) Filter Registry

The development of a novel endovascular grasper for challenging inferior vena cava filter retrieval

OBJECTIVE

Although inferior vena cava (IVC) filters are commonly retrieved using a snare, lateral tilt and fibrosis around struts can complicate the procedure and sometimes require the use of off-label devices. We describe the development of a novel articulating endovascular grasper designed to remove permanent and retrievable IVC filters in any configuration.

METHODS

For in vitro testing, the IVC filters were anchored to the inner wall of a flexible tube in a centered or tilted configuration. A high-contrast backlit camera view simulated the two-dimensional fluoroscopy projection during retrieval. The time from the retrieval device introduction into the camera field to complete filter retrieval was measured in seconds. The control experiment involved temporary IVC filter retrieval with a snare. There were four comparative groups: (1) retrievable filter in centered configuration; (2) retrievable filter in tilted configuration; (3) permanent filter in centered configuration; and (4) permanent filter in tilted configuration. Every experiment was repeated five times, with median retrieval time compared with the control group. For in vivo testing in a porcine model, six tilted infrarenal IVC filters were retrieved with grasper via right jugular approach. Comparison analysis between animal and patient procedures was performed for the following variables: total procedure time, the retrieval time, and fluoroscopy time.

RESULTS

The in vitro experiments showed comparable retrieval times between the experimental groups 1, 2, and 4 and the control. However, grasper removal of a centered permanent filter (group 3) required significantly less time than in the control (29 vs 79 seconds; P = .009). In the animal model, all IVC filters were retrieved using the grasper with no adverse events. The total procedure time (21.2 vs 43.5 minutes; P = .01) and the fluoroscopy time (4.3 vs 10 minutes; P = .044) were significantly shorter in the animal model compared with the patient group. Moreover, in the patient group, 16.7% of retrievals required advanced endovascular techniques, and one IVC filter could not be retrieved (success rate = 91.7%), whereas all the IVC filters were successfully retrieved in the animal model without the use of additional tools.

CONCLUSIONS

The novel endovascular grasper is effective in retrieving different types of IVC filters in different configurations and compared favorably with the snare in the in vitro model. In vivo experiments demonstrated more effective retrieval when compared with matched patient retrievals.

Predictors of retrieval and long-term mortality in patients treated with inferior vena cava filters

OBJECTIVE

Inferior vena cava filters (VCFs) are a therapeutic resource for the treatment of patients with thromboembolic disease who have a contraindication to full-dose anticoagulation. In the present study, we report the retrieval rate and long-term mortality of patients receiving optional inferior VCFs and identify the predictors for retrieval and all-cause mortality during follow-up.

METHODS

We conducted a retrospective cohort study of 739 consecutive recipients of optional inferior VCFs from January 2002 to December 2021 in two hospitals. Different clinical characteristics and procedure-related variables were included in the analysis. The all-cause mortality rate and retrieval rate and the predictive factors were evaluated using multivariate analysis.

RESULTS

Of the 739 patients, 393 (53%) were women. The mean patient age was 69 ± 15 years. Of the patients, 67% presented with pulmonary thromboembolism and 43% with deep vein thrombosis (DVT). A contraindication to anticoagulation was present for nearly 90% of the patients, mainly (47%) related to the surgical procedure. In addition, 44% of the patients had active cancer. Follow-up data were available for 94% of the patients, with an average follow-up time of 6.08 ± 5.83 years. Long-term mortality was 53%. Cancer (odds ratio [OR], 3.60; 95% confidence interval [CI], 2.22-5.83), age (OR, 1.03; 95% CI, 1.08-1.42), and DVT (OR, 2.01; 95% CI, 1.08-1.42) were identified as independent predictors of mortality. The retrieval rate at follow-up was 33%. The predictors for retrieval included the indication of the filter related to a surgical procedure (OR, 4.85; 95% CI, 2.54-9.59), the absence of cancer (OR, 2.89; 95% CI, 1.45-5.75), and younger age (OR, 0.98; 95% CI, 0.97-0.99).

CONCLUSIONS

High long-term mortality was observed. The predictors of mortality were cancer, older age, and DVT. One third of the filters implanted were retrieved. The predictors for retrieval were a contraindication to surgery-related anticoagulation, the absence of cancer, and younger age.

Guideline Compliance and Indications for Inferior Vena Cava Filter Placement at a Quaternary Care Medical Center

PURPOSE

This study investigated physician compliance with indications for inferior vena cava (IVC) filter placement according to the 2012 American College of Chest Physicians (ACCP) and the 2011 Society of Interventional Radiology (SIR) guidelines.

MATERIALS AND METHODS

A retrospective medical record review of 231 retrievable IVC filters placed between August 15, 2016, and December 28, 2017, at a large urban academic medical center. Guideline compliance to the 2012 ACCP and the 2011 SIR guidelines, and indications for IVC filter placements were assessed through an adjudication protocol. Filter retrieval and complication rates were also examined.

RESULTS

Compliance to guidelines was low (60.2% for ACCP; 74.0% for SIR), especially for non-intensive care unit (ICU) patients (ICU 74.6% vs non-ICU 54.8%, p=0.007 for ACCP; ICU 82.5% vs non-ICU 70.8%, p=0.092 for SIR). After adjudication, 8.2% (19/231) of filters were considered non-indicated but reasonable, 17.7% (41/231) non-indicated and unreasonable, and 13.9% (32/231) SIR-indicated but not ACCP-indicated. The most common indication was venous thromboembolism with contraindication to anticoagulation. The most common reasons for non-compliance were distal deep venous thrombosis with contraindication to anticoagulation (19/60, 31.6%) and clot burden (19/60, 31.6%). One-year filter retrieval and 90-day complication rates were 32.0% (74/231) and 6.1% (14/231), respectively.

CONCLUSION

Compliance to established guidelines was low. Reasons for non-compliance included limitations or discrepancies in guidelines, as well as non-evidence-based filter placements.

CLINICAL IMPACT

Despite increasing utilization of inferior vena cava (IVC) filters, guideline compliance for IVC filter placement among providers is unclear. The results of this study indicate that physician compliance to established guidelines is poor, especially in non-intensive-care-unit patients. Noncompliance stems from non-evidence-based filter placement as well as differences and limitations in guidelines. Avoiding non-indicated IVC filter placement and consolidation of guidelines may significantly improve guideline compliance. The critical insights gained from this study can help promote judicious use of IVC filters and highlight the role of venous thromboembolism experts in navigating complex cases and nuances of guidelines.

Retrieval of a Cook Celect inferior vena cava (IVC) filter after prolonged dwell time of 5,117 days: Factors to consider for retrieval of long-dwell IVC filters

Inferior vena cava (IVC) filters are used in certain patients to help prevent the occurrence of pulmonary embolism (PE). IVC filters are generally recommended to be removed once PE prophylaxis is no longer required. Long-dwelling IVC filters are associated with higher complication rates (Vasa 2020; 49: 449), being more difficult to retrieve and associated with higher retrieval complications (Cardiovasc Diagn Ther 2016; 6: 632). This report describes the pre-procedural work-up and removal of an IVC filter with a prolonged dwell time of 5,117 days (14 years, 3 days) using the loop snare advanced retrieval technique. As far as the authors are aware this case is the longest-described successful retrieval of a Cook Celect IVC filter at 5,117 days.

Changes in perfusion angiography after IVC filter placement and retrieval

Inferior vena cava (IVC) filters are posited to effect flow dynamics, causing turbulence, vascular remodeling and eventual thrombosis; however, minimal data exists evaluating hemodynamic effects of IVC filters in vivo. The purpose of this study was to determine differences in hemodynamic flow parameters acquired with two-dimension (2D)-perfusion angiography before and after IVC filter placement or retrieval. 2D-perfusion images were reconstructed retrospectively from digital subtraction angiography from a cohort of 37 patients (13F/24M) before and after filter placement (n = 18) or retrieval (n = 23). Average dwell time was 239.5 ± 132.1 days. Changes in the density per pixel per second within a region of interest (ROI) were used to calculate contrast arrival time (AT), time-to-peak (TTP), wash-in-rate (WIR), and mean transit time (MTT). Measurements were obtained superior to, inferior to, and within the filter. Differences in hemodynamic parameters before and after intervention were compared, as well as correlation between parameters versus filter dwell time. A P value with Bonferroni correction of <.004 was considered statistically significant. After placement, there was no difference in any 2D-perfusion variable. After retrieval, ROIs within and inferior to the filter showed a significantly shorter TTP (1.7 vs 1.4 s, P = .004; 1.5 vs 1.3 s, P = .001, respectively) and MTT (1.7 vs 1.4 s, P = .003; 1.5 vs 1.2 s, P = .002, respectively). Difference in variables showed no significant correlation when compared to dwell time. 2D-perfusion angiography is feasible to evaluate hemodynamic effects of IVC filters in vivo. TTP and MTT within and below the filter after retrieval were significantly changed, without apparent correlation to dwell time, suggesting a functional hemodynamic delay secondary to filter presence.

The application of inferior vena cava filters in orthopaedics and current research advances

Deep vein thrombosis is a common clinical peripheral vascular disease that occurs frequently in orthopaedic patients and may lead to pulmonary embolism (PE) if the thrombus is dislodged. pulmonary embolism can be prevented by placing an inferior vena cava filter (IVCF) to intercept the dislodged thrombus. Thus, IVCFs play an important role in orthopaedics. However, the occurrence of complications after inferior vena cava filter placement, particularly recurrent thromboembolism, makes it necessary to carefully assess the risk-benefit of filter placement. There is no accepted statement as to whether IVCF should be placed in orthopaedic patients. Based on the problems currently displayed in the use of IVCFs, an ideal IVCF is proposed that does not affect the vessel wall and haemodynamics and intercepts thrombi well. The biodegradable filters that currently exist come close to the description of an ideal filter that can reduce the occurrence of various complications. Currently available biodegradable IVCFs consist of various organic polymeric materials. Biodegradable metals have shown good performance in making biodegradable IVCFs. However, among the available experimental studies on degradable filters, there are no experimental studies on filters made of degradable metals. This article reviews the use of IVCFs in orthopaedics, the current status of filters and the progress of research into biodegradable vena cava filters and suggests possible future developments based on the published literature by an electronic search of PubMed and Medline databases for articles related to IVCFs searchable by October 2022 and a manual search for citations to relevant studies.

Application of Deep Learning to IVC Filter Detection from CT Scans

IVC filters (IVCF) perform an important function in select patients that have venous blood clots. However, they are usually intended to be temporary, and significant delay in removal can have negative health consequences for the patient. Currently, all Interventional Radiology (IR) practices are tasked with tracking patients in whom IVCF are placed. Due to their small size and location deep within the abdomen it is common for patients to forget that they have an IVCF. Therefore, there is a significant delay for a new healthcare provider to become aware of the presence of a filter. Patients may have an abdominopelvic CT scan for many reasons and, fortunately, IVCF are clearly visible on these scans. In this research a deep learning model capable of segmenting IVCF from CT scan slices along the axial plane is developed. The model achieved a Dice score of 0.82 for training over 372 CT scan slices. The segmentation model is then integrated with a prediction algorithm capable of flagging an entire CT scan as having IVCF. The prediction algorithm utilizing the segmentation model achieved a 92.22% accuracy at detecting IVCF in the scans.

Implications for patient follow-up of changes in inferior vena cava filter removal plan practices

AIM

To assess the improvements during patient follow-up after implementing a proactive plan for retrieval of inferior vena cava (IVC) filters.

MATERIALS AND METHODS

A retrospective study was undertaken including all patients who had a temporary IVC filter inserted over a 10-year period. Patient demographics, insertion dates, retrieval dates, retrieval rates, and complications were recorded. Patients were categorised into three groups as follows: group A, no intervention where retrieval was not suggested; group B, passive intervention where retrieval was suggested but no appointment made; and group C, proactive intervention where a retrieval date was booked by the radiologist.

RESULTS

Five hundred and nine patients had a temporary IVC filter inserted at Royal Liverpool University Hospital over the study period. One per cent of patients in group C were lost to follow-up compared to 41% and 29% in groups A and B respectively (p<0.001). The number of patients who had an IVC retrieval attempt also increased to 80% in group C compared to 53% and 64% in groups A and B (p<0.001).

CONCLUSION

Incorporation of a proactive retrieval booking system has significantly reduced the number of patients lost to follow-up to 1%, leading to an increased number of IVC filter retrieval attempts.

A single center 9-year experience in IVC filter retrieval - the importance of an IVC filter registry

Background

To evaluate Inferior vena cava (IVC) filter retrieval practices over a 9-year period at an academic hospital with a prospectively maintained IVC filter registry.

Method

An IVC filter registry was maintained prospectively within our institution. We reviewed cases between August 2011 and June 2020, following filter status, retrieval plans, and eventual retrieval date. The validity of the database was cross referenced with a Picture Archiving and Communication System and patient records.

Results

Three hundred forty-three patients had IVC filters inserted. Three filter types were used, Celect (Cook Medical) in 189, Gunther Tulip (GT) (Cook Medical) in 65, ALN (ALN) in 89. 196 (57%) filters were retrieved, 108 (31.5%) were made permanent, 36 (10.5%) died before retrieval, and 3 (1%) were yet to be retrieved.

Retrieval rates were 92.5% overall (86% for GT, 93% for Celect and 94.5% for ALN). The mean dwell time for successful retrieval was 59 days with the majority of insertions (85%) removed in under 100 days. Failed initial retrieval occurred in 23 patients, 10 (43%) were retrieved at second attempt, 13/23 filters remained in-situ and were deemed permanent.

Conclusion

The removal of IVC filters, when indication for insertion has past, is no longer the sole responsibility of the referring physician but also the responsibility of the Interventionalist. Our retrieval rates of 92.5% of eligible IVC filters highlights the value of maintaining a prospective IVC filter registry.

Vena Cava Filters: Toward Optimal Strategies for Filter Retrieval and Patients' Follow-Up

Mortality rates associated with venous thromboembolism (VTE) are high. Inferior vena cava filters (IVCFs) have been frequently placed for these patients as part of their treatment, albeit the paucity of data showing their ultimate efficacy and potential risk of complications. Issues regarding long-term filter dwell time are accounted for in society guidelines. This topic has led to an FDA mandate for filter retrieved as soon as protection from pulmonary embolism is no longer needed. However, even though most are retrievable, some were inadvertently left as permanent, which carries an incremental lifetime risk to the patient. In the past decade, attempts have aimed to determine the optimal time interval during which filter needs to be removed. In addition, distinct strategies have been implemented to boost retrieval rates. This review discusses current conflicts in indications, the not uncommon complications, the rationale and need for timely retrieval, and different quality improvement strategies to fulfill this aim.

Ibero-American Society of Interventionism (SIDI) and the Spanish Society of Vascular and Interventional Radiology (SERVEI) Standard of Practice (SOP) for the Management of Inferior Vena Cava Filters in the Treatment of Acute Venous Thromboembolism

Objectives: to present an interventional radiology standard of practice on the use of inferior vena cava filters (IVCFs) in patients with or at risk to develop venous thromboembolism (VTE) from the Iberoamerican Interventional Society (SIDI) and Spanish Vascular and Interventional Radiology Society (SERVEI). Methods: a group of twenty-two interventional radiologist experts, from the SIDI and SERVEI societies, attended online meetings to develop a current clinical practice guideline on the proper indication for the placement and retrieval of IVCFs. A broad review was undertaken to determine the participation of interventional radiologists in the current guidelines and a consensus on inferior vena cava filters. Twenty-two experts from both societies worked on a common draft and received a questionnaire where they had to assess, for IVCF placement, the absolute, relative, and prophylactic indications. The experts voted on the different indications and reasoned their decision. Results: a total of two-hundred-thirty-three articles were reviewed. Interventional radiologists participated in the development of just two of the eight guidelines. The threshold for inclusion was 100% agreement. Three absolute and four relative indications for the IVCF placement were identified. No indications for the prophylactic filter placement reached the threshold. Conclusion: interventional radiologists are highly involved in the management of IVCFs but have limited participation in the development of multidisciplinary clinical practice guidelines.

Risk factors associated with complex inferior vena cava filter retrievals and complications: A 7-year retrieval database analysis and the impact on retrieval rates at an Australian tertiary centre

INTRODUCTION

Venous thromboembolism (VTE) affects approximately 17,000 Australians annually. While anticoagulation is the mainstay of treatment, inferior vena cava filters (IVCFs) are used in patients where this is contraindicated. The primary aim was to identify risk factors for complex retrievals and IVCF-related complications following the establishment of a database at a single tertiary centre. The secondary aim was to evaluate the IVCF retrieval rate and patients lost to follow-up.

METHODS

A retrospective study at a single tertiary centre was conducted on IVCFs inserted from 2012 to 2018. Logistic regression models were used to evaluate potential risk factors for filter-related complications and complex retrievals.

RESULTS

In total, 402 patients had an IVCF inserted. Of these, 308 patients (77%) had a retrieval attempted, 10 (3%) of which required more than one retrieval attempt (complex retrieval). Factors associated with filter-related complications included dwell time (OR 1.02, 95% CI: 1.01-1.04) and select indications for insertion, namely VTE requiring thrombolysis/thrombectomy (OR 2.29, 95% CI: 1.02-5.16) and iliocaval/free-floating iliofemoral DVT without thrombectomy/thrombolysis (OR 5.89, 95% CI: 1.53-22.71). After mutual adjustment for all variables, only dwell time remained a significant factor for filter-related complications (adjusted OR 1.03, 95% CI: 1.01-1.05) and complex retrieval (AOR 1.05, 95% CI: 1.02-1.08). The annual retrieval rate increased from 73% (2012) to 83% (2018), with an overall retrieval rate of 75%.

CONCLUSION

Dwell time is a potential risk factor for filter-related complications and complex retrievals. The annual IVCF retrieval rate was 75% since an Interventional Radiology-led database was established.

Comparison of Retrievability and Indwelling Complications of Celect and Denali Infrarenal Vena Cava Filters: A Randomized, Controlled Trial

PURPOSE

To compare the Celect and Denali filters in terms of complex filter retrieval and indwelling complications after a 2-month indwelling time.

MATERIALS AND METHODS

In this prospective, randomized trial, 153 subjects were assessed for eligibility between May 2016 and July 2018. A total of 136 participants were randomly assigned to receive either Celect (n = 68) or Denali (n = 68) filter placement in the infrarenal inferior vena cava. Tilt angles at placement and retrieval and rates of overall filter retrieval, indwelling complication, and complex retrieval were compared.

RESULTS

Of 136 participants (mean age, 62 ± 12.8 years, 55 male), 24 (17.6%) were lost to follow-up. The mean indwelling time of filter was 60.4 ± 7 days and there was no significant difference in the baseline characteristics between the two groups. Filter retrieval was successful in all participants (112/112, 100%). Significantly higher rates of filter tilt > 15° (n = 8) and strut penetration (n = 14) were found with the Celect filter than with the Denali filter (1 significant tilt and 1 penetration) (P = 0.033 and 0.001, respectively). No filter fractures were observed and there was no significant difference in tip embedment, filter fracture, filter migration, or mean fluoroscopy times. There were 3 cases of complex retrieval (1 for Denali vs. 2 for Celect, P = 0.500), for which the loop-snare technique was used.

CONCLUSION

Denali filters demonstrated significantly lower rates of tilt angle > 15° and strut penetration. However, there was no significant difference in the complex filter retrieval rate between the Celect and Denali filters.

Retroperitoneal Laparoscopic-Assisted Retrieval of Wall-Penetrating Inferior Vena Cava Filter After Endovascular Techniques Failed: An Initial Clinical Outcome

BACKGROUND

Inferior vena cava (IVC) filters are commonly used in China to prevent pulmonary embolisms in patients with deep vein thrombosis. However, IVC filter removal is complicated when the filter has penetrated the IVC wall and endovascular techniques usually fail. The purpose of this study was to evaluate the effectiveness and safety of retroperitoneal laparoscopic-assisted retrieval of wall-penetrating IVC filters after endovascular techniques have failed.

PATIENTS AND METHODS

We retrospectively evaluated a series of 8 patients who underwent retroperitoneal laparoscopic-assisted retrieval of a wall-penetrating IVC filter between December 2017 and November 2019. All patients had experienced at least 1 failure with endovascular retrieval before the study. The filters were slanted and the proximal retrieval hooks penetrated the posterior lateral IVC wall in all patients on computed tomography. Demographic information, operation parameters, and complications were recorded and analyzed. All patients were followed up for at least 12 months.

RESULTS

The procedure was successful in all patients. The median surgery time was 53.6 ± 12.7 min and the average blood loss was 45.0 ± 13.5 ml. No serious complication occurred during the patients' hospitalization, which was an average of 6.4 days. The median follow-up time was 15.1 months, and no patient had deep vein thrombosis recurrence.

CONCLUSIONS

Retroperitoneal laparoscopic-assisted retrieval is a feasible and effective technique, particularly when proximal retrieval hooks penetrate the posterior lateral wall of the IVC after endovascular techniques have failed. To some extent, the development of this technique at our institution has increased the success rate of filter removal and improved patient satisfaction.

Inferior vena cava filters utilization in patients with venous thromboembolism: Analysis of a database of a tertiary hospital

PURPOSE

The aim of the study was to assess the inferior vena cava filter (IVCF) utilization in patients with venous thromboembolism (VTE) in tertiary care.

METHODS

We performed a retrospective analysis of database of a tertiary hospital in 2016-2017. All the records of patients admitted for VTE or diagnosed with VTE being hospitalized for other reasons were extracted. The data collected were number of patients, who received IVCF, indications to filter insertion, PE and death rate after procedure, frequency of IVCF occlusion.

RESULTS

2399 patients with VTE were admitted to hospital. 442 (18,4%) of them received IVCF (239 in 2016 and 203 in 2017). Retrievable models were used in most cases (98,8%). In 119 (5,0%) patients cava filters were used due to contraindications for anticoagulation, while in 184 (7,7%) patients' anticoagulation was not effective and thrombosis progression was registered. 101 (4,2%) patients received IVCF due to high PE risk (length of floating thrombus ≥7 cm, in proximal location), high pulmonary hypertension was indication to IVCF insertion in 38 (1,6%) patients with deep vein thrombosis (DVT) in combination with pulmonary embolism (PE). Overall mortality rate after IVCF insertion was 5 (0,2%). No fatal PE was registered. IVCF occlusion during hospitalization occurred in 116 (4,8%) cases. Only 29 (1,2%) of patients were admitted back for IVCF removal.

CONCLUSIONS

Every one in five patients with proximal DVT and/or PE receives IVCF in a routine practice in tertiary hospital. The most common indications for IVCF implantation were inability for anticoagulation or anticoagulation failure. Removal rate of retrievable cava filters is low.

Effect of a dedicated inferior vena cava filter retrieval program on retrieval rates and number of patients lost to follow-up

PURPOSE We aimed to assess the efficacy of a dedicated inferior vena cava (IVC) filter retrieval program on filter retrieval rates and number of patients lost to follow-up. METHODS A dedicated IVC filter retrieval program began in July 2016. This consisted of tracking all patients with retrievable filters placed by interventional radiology (IR). At the time of filter placement, patients were scheduled for a retrieval consult in the IR clinic. Any missed appointments were followed up by a physician assistant. The program was overseen by a single IR physician. To assess this program's efficacy, we reviewed the records of all patients who had retrievable IVC filters placed by IR nine months prior to and nine months after program initiation. Demographics and clinical factors were then collected and compared. A P value of < 0.05 was considered statistically significant. RESULTS Prior to the program, 76 patients (31 males, 45 females; mean age, 64.2 years) had retrievable filters placed; 75% were placed due to a contraindication to anticoagulation. From this group, five filters were removed (6.6%), 42 patients were lost to follow-up (55.3%), 22 patients died (29.0%), and seven filters were deemed permanent by a physician after placement (9.2%). All five retrievals were successful and no complications were reported. After program initiation, 106 patients (59 males, 47 females; mean age, 58.8 years) had retrievable filters placed; 75.5% were placed due to a contraindication to anticoagulation. In this group, 30 filters were retrieved (retrieval rate 28.3%), 17 patients were lost to follow-up (16%), 23 patients died (21.7%), 28 filters were deemed permanent by a physician after placement (26.4%), and decisions were still pending in eight patients (7.5%). One patient (3.3%) had a minor complication during filter retrieval. Initiation of a filter retrieval program increased our retrieval rate (6.6% vs. 28.3%; P < 0.001) and reduced the number of patients with filters that were lost to follow-up (55.3% vs. 16%; P < 0.001). CONCLUSION Dedicated filter retrieval program is effective in increasing filter retrieval rates and decreasing the number of patients lost to follow-up.

Costs and complications of hospital admissions for inferior vena cava filter malfunction

OBJECTIVE

Inferior vena cava filter (IVCF) malfunction can result from penetration, fracture, or migration of the device necessitating retrieval. Endovascular and open retrieval of IVCF have been described in institutional series without comparison. This study examines national hospital admissions for IVCF malfunction and compares the outcomes of open and endovascular retrieval.

METHODS

The National Inpatient Sample database (2016-2017) was reviewed for admissions with International Classification of Diseases, Tenth Revision (ICD-10) codes specific for IVCF malfunction. All ICD-10 procedural codes were reviewed, and patients were divided based on open or endovascular IVCF retrieval. Patient characteristics, outcomes, and costs of hospitalization were compared between the two groups.

RESULTS

There were 665 patients admitted with a diagnosis of IVCF malfunction. Open IVCF retrieval was performed in 100 patients and endovascular removal in 90 patients. Of those undergoing open surgery, 45 patients (45%) required median sternotomy and 55 (55%) required abdominal surgeries. Most patients were white females with a mean age of 54.4 years (range, 49.3-59.6 years) with a history of deep venous thrombosis (55.3%) or pulmonary embolism (31.6%). Most patients with IVCF malfunction were treated in large (81.6%) or urban teaching (94.7%) hospitals situated most commonly in the South (42.1%) and Northeast (29.0%) with no difference in characteristics of the patients or the centers between the two groups. Patients undergoing open IVCF retrieval were more likely to undergo surgery on an elective basis compared with endovascular IVCF retrieval (75.0% vs 11.1%; P < .001). Open IVCF retrieval was associated with a higher likelihood of thromboembolic complication compared with endovascular retrieval (20% vs 0%; P = .04). There was a trend toward higher infectious complications and overall complications with endovascular removal, but this difference did not reach statistical significance. Open retrieval was associated with a mortality of 5.0% compared with no inpatient mortality with endovascular retrieval (P = .33). The mean hospital length of stay was no difference between the two groups. Open retrieval was associated with significantly higher hospital costs than endovascular retrieval ($34,276 vs $19,758; P = .05).

CONCLUSIONS

Filter removal for patients with IVCF malfunction is associated with significant morbidity and cost, regardless of modality of retrieval. The introduction of specific ICD-10 codes for IVCF malfunction allows researchers to study these events. The development of effective tools for outpatient retrieval of malfunctioning IVCF could decrease related hospitalization and have potential savings for the healthcare system.

Spanish multicenter real - life registry of retrievable vena cava filters (REFiVeC)

BACKGROUND

The treatment of venous thromboembolic disease the treatment of choice is systemic anticoagulation. However, the interruption of the inferior vena cava with filters has been recommended when anticoagulation fails or there is a contraindication. Due to the rising inferior vena cava filter (IVCF) complications, physicians are encouraged to retrieve them when there is no longer recommended. In daily practice, it may be a difficult close follow-up of these patients. In this study, the primary objective was to evaluate the IVCF retrieval rate of all implanted filters in a Spanish registry. Secondary objectives were to analyze the causes of failed retrieval, procedure-related complications, and outcomes at a 12-month follow-up.

RESULTS

Three hundred fifty-six vena cava filters were implanted in 355 patients. The types of filter were: Gunther Tulip (Cook Medical) 160 (44.9%), Optease (Cordis) 77 (21.6%), Celect (Cook Medical) 49 (13, 7%), Aegisy (Lifetech Scientific) 33 (9.2%), Option ELITE (Argon Medical devices) 16 (4.4%), Denali filter (BD Bard) 11 (3.08%), ALN filter (ALN) 10 (2.8%). Removal was achieved in 274/356 (76,9%). eighty-two (23,1%) IVCF were not retrieved due to the following: 41 (11,5%) patients required ongoing filtration, 24 IVCF (6,7%) patients died before retrieval, and 17 (4,7%) impossibility of retrieval because of a tilted and embedded filter apex. There were no major complications observed.

CONCLUSIONS

The global retrieval rate of IVCF was achieved in 76.9%, and the adjusted retrieval rate was of 94.15% with no major complications. IVCF tilting was associated with failure of filter removal in less than 5% of cases. This study demonstrates that the retrieval procedure of IVCF is controlled by the clinician and not by the interventional radiologist.

Improving the practice of inferior vena cava filter retrieval: a quality improvement intervention and audit outcomes

OBJECTIVE

To review inferior vena cava (IVC) filter retrieval practice at our institution, the Royal London Hospital, and measure changes following a quality improvement intervention. IVC filters are a preventive treatment for pulmonary embolism when anticoagulation is ineffective/contraindicated. Unless permanent filtration is required, all filters should undergo attempted retrieval within manufacturer's recommendations with a success rate of ≥80 %.

METHODS

Retrospective audit of filters inserted between 2011 and 2014, followed by a quality improvement intervention and a second audit between 2015 and 2017. Clinical-radiological data were analysed using the Picture Archiving and Communication System and electronic patient records.

RESULTS

During the first audit, filter retrieval was attempted in 92% of cases, of which 82% underwent the procedure within manufacturer's recommendations and 86% were successful. During the second audit, an improvement across indicators was seen. Retrieval increased by 3% and was attempted in 95% of cases (92% of which were within manufacturer's guidelines). Rate of retrievals within manufacturer's guidelines increased by 10%. Filter retrieval success rate increased by 11% - to 97%.

CONCLUSIONS

IVC filter retrieval practice at a single institution can be improved by implementing a simple audit intervention.

ADVANCES IN KNOWLEDGE

Filter retrieval practice has clinical and medicolegal implications. A simple quality intervention can substantially improve overall practice.

Surgical Removal of the Inferior Vena Cava Filter Using Minimal Cavotomy: A Case Report

The use of retrievable inferior vena cava (IVC) filters has markedly increased in the recent years. However, the failure rate for the retrieval of the IVC filters using the endovascular method is reported to be up to 19%. Open surgical removal of the IVC filters is technically challenging and may require longitudinal cavotomy, clamping, and repair of the IVC. Here, we present a case of successful open surgical removal of the IVC filter using minimal cavotomy. This technique is an effective method after a failed endovascular removal attempt.

Inferior vena cava filters (IVCFs): a review of uses and application to international guidelines at a single Australian center; implications of venous thromboembolism associated with malignancy

Venous thromboembolism (VTE) is a potentially lethal event. Anticoagulation is the cornerstone of treatment. Inferior vena cava filters (IVCFs) may be used in circumstances when anticoagulation is contraindicated or as an adjunct to anticoagulation. IVCF use is not without controversy due to concerns over their safety profile, differences in guidelines from international societies, and a limited randomized control trial evidence. We retrospectively undertook a review of IVCF use over a three-year period (2014–2016) at our center, which has a large oncology service but no trauma unit. There were 44 patients with successful IVCF insertion and one patient with an unsuccessful attempt. Indications for insertion included: a contraindication to anticoagulation (n = 28); recurrent VTE on anticoagulation (n = 10); and extensive VTE (n = 7). There were 13 retrieval attempts, of which ten were successful. There were five documented IVCF complications (tilting: n = 2, IVC thrombus: n = 3) with one episode of IVCF failure and two episodes of deep vein thrombosis during the follow-up period. Of the patients, 71% had an active malignancy (of whom 71% had metastatic disease). Seventeen patients died due to progressive malignancy during the study period. There were no life-threatening VTEs or IVCF-associated mortalities. Adherence with published international guidelines was variable. Patients with malignancy were less likely to undergo IVCF retrieval and had a reduced rate of retrieval success. None of the international guidelines comment on the use of IVCFs in patients with malignancy despite being commonly used. IVCF use may be an underappreciated tool in this group.

Retrievable inferior vena cava filter utilization in obstetric patients

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

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

BACKGROUND

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

CASE DESCRIPTION

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

CONCLUSIONS

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

Endovascular Iliocaval Stent Reconstruction for Iliocaval Thrombosis: A Multi-Institutional International Practice Pattern Survey

BACKGROUND

Limited guidelines for the treatment and management of acute and chronic iliocaval thrombosis are published in the literature. The purpose of this report is to present global iliocaval stent reconstruction practices by interventionalists.

METHODS

A 45-question survey focusing on iliocaval stent reconstruction evaluation was distributed through the Open Forum and Venous Disease Service Line of the Society of Interventional Radiology Connect website from June 20, 2017 until September 7, 2017 and the Cardiovascular and Interventional Radiological Society of Europe electronic newsletter on August 11, 2017.

RESULTS

One hundred seven complete responses were received from interventional radiologists in the United States, 2 from South America, and 2 from Central America. 92.5% performed iliocaval reconstruction, and 79.8% performed the procedure for both acute and chronic iliocaval thrombosis. 82.8% completed a standardized physician assessment tool, and 91.9% obtained computed tomography (CT) venography before the procedure. 64.6% used intravascular ultrasound to guide reconstruction. 41.4% found blunt recanalization successful for >75% of patients. 63.6% used sharp recanalization for <25% of patients. 97.0% and 90.9% used uncovered and self-expanding stents, respectively. Wallstents were used most commonly. Most common stent diameters were 24-mm in the inferior vena cava, 14-mm in the common iliac vein, and 12-mm in the external iliac vein. 48.5% and 21.2% prescribed 2 and 3 anticoagulants after stent placement, respectively. 62.6% found iliocaval reconstruction provided symptomatic clinical improvement for iliocaval thrombosis in >75% of patients. 72.7% estimated their 1-year primary stent patency to be >75%.

CONCLUSIONS

Iliocaval reconstruction is performed by many interventionalists; however, there are global inconsistencies in practices, suggesting a need for further research and guideline development.

Ten-year experience of retrievable inferior vena cava filters in a tertiary referral center

PURPOSE

A significant proportion of patients undergoing surgery have an increased incidence of acute pulmonary embolus (PE). We analyzed all patients who had a retrievable inferior vena cava (IVC) filter placed preoperatively for PE prophylaxis and investigated the long-term outcomes of the patients who did not have their filter removed.

METHODS

Patients who underwent retrievable IVC filter insertion and attempted removal were identified from the radiology information systems database in a large tertiary referral university teaching hospital. Results of all clinical investigations (including computed tomography, magnetic resonance imaging, ultrasonography, and plain radiography) while the IVC filters were in situ were reviewed.

RESULTS

In total, 393 retrievable IVC filters were inserted, 254 with the indication of preoperative thromboembolic prophylaxis. Recurrent PE was reported in five patients (1.9%) despite the IVC filter. Of the 254 retrievable filters inserted prior to surgery, an attempt at retrieval was made in 168 filters (66.1%). Successful retrieval at the first attempt occurred in 143 cases (85.1%), while 25 cases failed or were aborted (14.9%). No attempt at retrieval was made in 86 (33.9%) patients and a significant proportion of these patients had undergone cancer surgery (P < 0.0107). In those patients where there was no attempt at retrieval, there was an association between cancer surgery and a shorter absolute survival time (P < 0.0001).

CONCLUSION

The majority of attempted filter retrievals were successful, and a proportion of nonretrieved IVC filters are accounted for in patients who underwent cancer surgery and ultimately died with the filter in situ. A departmental protocol is recommended to ensure the filter is removed where appropriate and possible.

Vena Cava Filter Retrieval Rates and Factors Associated With Retrieval in a Large US Cohort

Background

Retrieval of vena cava filters (VCFs) is important for safety as complications increase with longer dwell times. This study assessed VCF retrieval rates and factors associated with retrieval in a national cohort.

Methods and Results

VCFs were identified by procedural codes from an administrative claims database. Patients were identified who had a VCF placement during a hospitalization from a national commercial administrative claims database. Indications for VCF placement were identified as pulmonary embolism with or without deep vein thrombosis, deep vein thrombosis only, or prophylactic. Patient demographic and clinical characteristics were included in proportional hazard regression models to find associations with early (90‐day) and 1‐year VCF retrieval. Initiation of anticoagulation and the correlation between time‐to‐retrieval and time‐to‐initiation of anticoagulation were observed. Of 54 766 patients receiving a VCF, 36.9% had pulmonary embolism, 43.9% had deep vein thrombosis only, and 19.2% had no apparent venous thromboembolism present. Over the 1 year of follow‐up, the cumulative incidence of VCF retrieval was 18.4%. Retrieval increased over time from a low of 14.0% in 2010 up to ≈24% in 2014. In adjusted time‐to‐event models, increasing age, differing regions, and some comorbidities were associated with poorer retrieval rates. Initiation of anticoagulation was poorly correlated with retrieval, with anticoagulation preceding retrieval by a median of 51 days while those without retrieval had a median of 278 days of exposure to anticoagulation.

Conclusions

VCF retrieval increased over the study period but remained suboptimal and was weakly correlated with anticoagulation initiation.

Cost-benefit analysis of establishing an inferior vena cava filter clinic

PURPOSE

Adverse events associated with retrievable inferior vena cava filters (IVCFs) have generated an increased interest in improving IVCF retrieval rates to improve patient safety and quality care. This study aims to demonstrate the cost-benefit of implementing an IVCF clinic to improve patient care in an institution in the United States.

METHODS

An IVCF clinic was established at a single institution in September 2012 and for ten months referring physicians were contacted to facilitate retrieval when appropriate. Additionally, a retrospective review was conducted on filter placements over the eight preclinic months. Cost-benefit analysis was conducted by creating a model, which incorporated the average cost and reimbursement for permanent and retrievable IVCFs.

RESULTS

A total of 190 IVCFs (152 retrievable IVCFs and 38 permanent IVCFs) were implanted during the IVCF clinic period. Twenty-nine percent of the retrievable IVCFs were successfully retrieved compared to 10 of 119 retrievable IVCFs placed during the preclinic period (8.4%). Cost-benefit analysis, using the average of the institution's six most common reimbursement schedules, demonstrated an average net financial loss per permanent or retrievable IVCF not removed. However, a net financial gain was realized for each retrievable IVCF removed. The additional hospital cost to maintain the IVCF clinic was offset by removing an additional 3.1 IVCFs per year.

CONCLUSION

An IVCF clinic significantly increases retrieval rates, promotes patient safety, and is economically feasible. Given the adverse event profile of retrievable IVCFs, strategic efforts such as these ultimately can improve quality care for patients with in-dwelling IVCFs.

Genetic Analysis of Venous Thromboembolism in UK Biobank Identifies the ZFPM2 Locus and Implicates Obesity as a Causal Risk Factor

BACKGROUND

UK Biobank is the world's largest repository for phenotypic and genotypic information for individuals of European ancestry. Here, we leverage UK Biobank to understand the inherited basis for venous thromboembolism (VTE), a leading cause of cardiovascular mortality.

METHODS AND RESULTS

We identified 3290 VTE cases and 116 868 controls through billing code-based phenotyping. We performed a genome-wide association study for VTE with ≈9 000 000 imputed single-nucleotide polymorphisms. We performed a phenome-wide association study for a genetic risk score of 10 VTE-associated variants. To assess whether obesity is a causal factor for VTE, we performed Mendelian randomization analysis using a genetic risk score instrument composed of 68 body mass index-associated variants. The genome-wide association study for VTE replicated previous findings at the F5, F2, ABO, F11, and FGG loci. We identified 1 new locus-ZFPM2 rs4602861-at genome-wide significance (odds ratio, 1.11; 95% confidence interval, 1.07-1.15; P=4.9×10^-10) and a new independent variant at the F2 locus (rs3136516; odds ratio, 1.10; 95% confidence interval, 1.06-1.13; P=7.60×10^-9). In a phenome-wide association study, a 10 single-nucleotide polymorphism VTE genetic risk score was associated with coronary artery disease (odds ratio, 1.08; 95% confidence interval, 1.05-1.10 per unit increase in VTE odds; P=1.08×10^-9). In a Mendelian randomization analysis, genetically elevated body mass index (a 1 SD increase) was associated with 57% higher risk of VTE (odds ratio, 1.57; 95% confidence interval, 1.08-1.97; P=0.003).

CONCLUSIONS

For common diseases such as VTE, biobanks provide potential to perform genetic discovery, explore the phenotypic consequences for disease-associated variants, and test causal inference.

Indications, complications and outcomes of elderly patients undergoing retrievable inferior vena cava filter placement

AIM

The utilization of inferior vena cava filter placement for pulmonary embolism prevention in elderly patients has not been well characterized. The present study aimed to review indications, complications and follow-up data of elderly patients undergoing inferior vena cava filter placement.

METHODS

A retrospective review was carried out of consecutive admitted patients who underwent inferior vena cava filter insertion at a large university hospital with a level I trauma center.

RESULTS

Overall, 455 retrievable filters were inserted between 2009 and 2014. A total of 133 patients (29.2%) were aged ≥70 years. Elderly patients were less likely to have their filter retrieved compared with non-elderly patients (5.3% vs 21.4%, P < 0.001). Filter-related complications occurred in 13% of non-elderly patients and 14.3% of elderly patients (P = 0.72), most of them occurring in the first 3 months after filter placement. Survival among elderly patients with no evidence of active malignancy was similar to the non-elderly patients with a 1-year survival rate of 76.3% versus 82% in non-elderly patients (P = 0.22), and a 2-year survival rate of 73.1% versus 78.6% in non-elderly patients (P = 0.27). Although decreased, survival rates among elderly patients with active cancer were still substantial, with a 1-year survival rate of 45% and 2-year survival rate of 40%.

CONCLUSIONS

Elderly patients had significantly lower rates of filter retrieval with similar complication rate. Survival rates among elderly patients were substantial, and in elderly patients with no active cancer were even comparable with non-elderly patients. When feasible, filter retrieval should be attempted in all elderly patients in order to prevent filter-related complications. Geriatr Gerontol Int 2017; 17: 1508-1514.

Retrievable IVC filters - Friend or foe

Venous thromboembolism is a common condition with widely varied outcomes. Pulmonary embolism is associated with a case-fatality rate of up to 8%, increasing up to 18-fold in massive PE. Pharmacological treatment of VTE with anticoagulant medication (AC) is the first line therapy of choice. Retrievable inferior vena cava filters (IVCF) are indicated as a short-term replacement for AC in certain circumstances. Most of the evidence concerning IVCF pertains to permanent filters and older filter models. Limited evidence for retrievable IVCF results in poor consensus regarding indications, follow-up and retrieval. Complications increase with dwell-time and retrieval success rates decline. Professional bodies advocate strict guideline adherence and robust strategies for filter monitoring to maximise retrieval rate.

Impact of Physician Education and a Dedicated Inferior Vena Cava Filter Tracking System on Inferior Vena Cava Filter Use and Retrieval Rates Across a Large US Health Care Region

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.

A Multicenter Cohort Study of Inferior Vena Cava Filter Use in Children

BACKGROUND

To describe inferior vena cava (IVC) filter use in pediatric patients admitted to U.S. children's hospitals and to determine factors associated with prophylactic placement.

PROCEDURE

This retrospective multicenter cohort study utilized data from the Pediatric Health Information Systems (PHIS) administrative database, with 44 participating children's hospitals. Subjects included for analysis were less than 21 years of age, admitted to a PHIS hospital between January 1, 2004 and December 31, 2012 and had a procedure code for IVC filter placement. ICD-9-CM discharge codes were used to identify subjects with a venous thromboembolism (VTE). Pharmaceutical billing codes were used to identify anticoagulation use.

RESULTS

During this 9-year-study period, 276 subjects met the inclusion criteria. The median age of subjects was 15 years (range 1 month-20 years). Subjects had an ICD-9-CM code for VTE 76% of the time and were started on anticoagulation after IVC filter placement 77% of the time. The mean number of IVC filters placed per year was 6 per 100,000 admissions (SD-1.4), which was constant throughout the study period (P = 0.12). The median number of filters placed by center was 4.5 (range 0-32). In multivariate analysis, subjects undergoing orthopedic surgery were more likely to have prophylactic placement of an IVC filter (OR 4.5; 95%CI 1.8-11).

CONCLUSIONS

IVC filter placement in pediatric patients remains a rare event and is most common in adolescents. Unlike in adults, pediatric IVC filter placement does not appear to be increasing over time and is predominantly used in the setting of a venous thrombotic event.

Inferior vena cava (IVC) filters in children: A 10-year single center experience

BACKGROUND

Venous thromboembolism (VTE) is an increasingly recognized problem among children and adolescents. Although inferior vena cava (IVC) filter placement for pulmonary embolism prevention is well reported in adults, data regarding safety and efficacy in the pediatric age group are lacking.

PROCEDURE

At a large university hospital with a level I trauma center, medical records of children and adolescents who underwent IVC filter insertion were reviewed. Appropriateness of referral for retrieval was assessed in each case.

RESULTS

Fifty-nine children and adolescents (mean age 16 years) successfully underwent IVC filter insertion. All filters placed were retrievable. In 47 patients (79.7%), prophylactic filters were placed in the absence of acute VTE in the setting of trauma. In eight patients (13.5%), filters were placed due to contraindication to anticoagulation therapy with concomitant lower extremity deep vein thrombosis or pulmonary embolism. Filters were successfully retrieved in only 12 patients (20.3%), although an attempt at removal was appropriate and feasible in over 90% of cases. Mean duration of follow-up was 2.1 (range 0.4-7.3) years. A significantly higher retrieval rate was found in patients followed at our thrombosis clinic (P < 0.01). Ten patients (17%) experienced at least one filter-related complication.

CONCLUSIONS

Although in most cases, IVC filters were placed for prophylactic indications, the evidence to support their role in this setting is limited. Their low retrieval rate and high filter-related complication rate question their extensive utilization in children. Dedicated follow-up is necessary to detect complications and to ensure that an attempt at retrieval is made when feasible.

Retrievable inferior vena cava filters can be placed and removed with a high degree of success: Initial experience

OBJECTIVES

Evaluate the success rate of retrievable inferior vena cava filter (IVC) removal in a tertiary care practice.

BACKGROUND

Retrievable IVC filters became readily available in the United States following Food and Drug Administration approval in 2003, and their use has increased dramatically. They represent an attractive option for patients with contraindications to anticoagulation who may only need short-term protection against pulmonary embolism.

METHODS

All patients who had undergone placement of a retrievable IVC filter at Mayo Clinic between 2003 and 2005 were retrospectively reviewed to evaluate our initial experience with retrievable inferior vena cava filters at a large tertiary care center.

RESULTS

During a three-year-period of time, Mayo Clinic, Rochester, MN placed 892 IVC filters of which 460 were retrievable. Of the 460 retrievable filters placed (249 Günther Tulip®, 207 Recovery®, and 4 OptEase®), retrieval was attempted in 223 (48.5%). Of 223 initial attempts, 196 (87.9%) were initially successful and 27 (12.1%) were unsuccessful. Of the 27 unsuccessful initial retrieval attempts, 23 (85.2%) were because of the presence of significant thrombus within the filter and 4 (14.8%) were because of tilting and strut perforation. Of the 23 filters containing significant thrombus, 9 (39.1%) were later retrieved after a period of anticoagulation and resolution of the thrombus.

CONCLUSIONS

Retrievable IVC filters can be removed with a high degree of success. Approximately one in ten retrievable IVC filter removal attempts may fail initially, usually because of significant thrombus within the filter. This does not preclude possible removal at a later date.