The Impact of Implementation of a Commercial Inferior Vena Cava Filter Database Program on Filter Retrieval versus Physician Tracking over a 9-Year Period: A Retrospective, Observational Study.

PURPOSE: To compare the impact of a commercial tracking database on inferior vena cava filter retrievals with that of physician tracking and no tracking. MATERIALS AND METHODS: From January 2013 to December 2021, 532 filters were placed at a single institution and followed in 3 phases: (a) Phase 1, pretracking (January 1, 2013, to February 28, 2015); (b) Phase 2, commercial database tracking (March 1, 2015, to June 30, 2019); and (c) Phase 3, commercial database tracking with separate tracking by an interventional radiologist (July 1, 2019, to December 31, 2021). Patients excluded from the commercial database due to human error served as a control group. Outcomes of commercial database entry, 2-year filter retrieval rates, dwell times, and factors contributing to retrieval candidacy were collected. RESULTS: Two-year retrieval rates in Phases 1, 2 and 3 were 20%, 31%, and 46%, respectively (Phase 1 vs 2, P = .04; Phase 2 vs 3, P = .009). Median dwell times across Phases 1, 2, and 3 were 168 days (4-1,313 days), 140 days (3-1,988 days), and 188 days (13-734 days) (P = .33), respectively. There was no difference in retrieval rates (P = .86) and dwell times (P = .50) between patients enrolled in the database group and those enrolled in the control group. Across all phases, 48% of patients enrolled in the database were not successfully contacted, and only 6% were categorized as "likely to consult" filter retrieval. During Phase 3, 100% of patients achieved a retrieval disposition. CONCLUSIONS: A commercial tracking database had low success rates of contacting patients and did not increase filter retrieval rates relative to those in the control group; however, physician tracking increased retrieval rates.

Image-Guided Deployment and Monitoring of a Novel Tungsten Nanoparticle-Infused Radiopaque Absorbable Inferior Vena Cava Filter in a Swine Model.

PURPOSE: To improve radiopacity of radiolucent absorbable poly-p-dioxanone (PPDO) inferior vena cava filters (IVCFs) and demostrate their effectiveness in clot-trapping ability. MATERIALS AND METHODS: Tungsten nanoparticles (WNPs) were incorporated along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of WNPs. The physicochemical and in vitro and in vivo imaging properties of PPDO IVCFs with WNPs with single-polymer PHB (W-P) were compared with those of WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). RESULTS: In vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physicomechanical properties of the PPDO sutures. W-P- and W-PB-coated IVCFs were deployed successfully into the inferior vena cava of pig models with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at Week 3 for both filters. CONCLUSIONS: The results highlight the utility of nanoparticles (NPs) and polymers for enhancing radiopacity of medical devices. Different methods of incorporating NPs and polymers can still be explored to improve the effectiveness, safety, and quality of absorbable IVCFs.

Supply Costs in Complex and Routine Inferior Vena Cava Filter Retrieval: 10 Years' Data from a Single Center.

PURPOSE: To characterize the medical supply costs associated with inferior vena cava filter retrieval (IVCFR) using endobronchial forceps (EFs), a snare, or Recovery Cone (RC). MATERIALS AND METHODS: In total, 594 of 845 IVCFRs attempted at a tertiary referral hospital between October 1, 2012, and June 20, 2022 were categorized by intended retrieval strategy informed by, rotational cavography as follows: (a) EF (n = 312) for tilted or tip-embedded/strut-embedded filters and for long-dwelling closed-cell filters and (b) a snare (n = 255) or (c) RC (n = 27) for other well-positioned filters with or mostly without hooks, respectively. List prices of relevant supplies at time of retrieval were obtained or, rarely, estimated using a standard procedure. Contrast use, fluoroscopic time, filter type, dwell time, and patient age and sex were recorded. Mean between-group cost differences were estimated by linear regression, adjusting for date. Additional models evaluated filter type, dwell time, and patient-level effects. RESULTS: Of the 594 IVCFRs, 591 were successful, whereas 2 EF and 1 snare retrievals failed. Moreover, 4 EF retrievals were successful with a snare and 2 with smaller EF, 12 snare retrievals were successful with EF, 1 RC retrieval was successful with a snare and 2 with EF. Principal model indicated a significantly lower mean cost of EF ($564.70, SE ± 9.75) than that of snare ($811.29, SE ± 10.83; P < .0001) and RC ($1,465.48, SE ± 47.12; P < .0001) retrievals. Adjusted models yielded consistent results. Had all retrievals been attempted with EF, estimated undiscounted full-period supplies savings would be $87,201.51. CONCLUSIONS: EFs are affordable for complex IVCFR, and extending their use to routine IVCFR could lead to considerable cost savings.

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 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.

Independent association between IVC filter placement and VTE risk in patients with upper gastrointestinal bleeding and isolated distal DVT: A retrospective cohort study.

BACKGROUND: The placement of inferior vena cava (IVC) filters often emerges as an alternative preventative measure against pulmonary embolism in patients with upper gastrointestinal (GI) bleeding and isolated distal deep vein thrombosis (DVT). We aimed to investigate the association of IVC filter placement and the incidence of venous thromboembolism (VTE) recurrence in this patient population. METHODS: We performed a retrospective cohort study including 450 patients with upper GI bleeding and isolated distal DVT. Propensity score matching using logistic regression was conducted to mitigate potential selection bias. Logistic regression models and additional sensitivity analyses were conducted to estimate the association between IVC filter implantation and VTE recurrence. Interaction and stratified analyses were also performed according to the background covariates. RESULTS: Patients who underwent IVC filter placement were significantly younger than patients in the surveillance group (55.8 ± 9.0 vs 58.4 ± 11.2 years, p = 0.034). Patients in the IVC filter group demonstrated a higher distal thrombus burden. The VTE recurrence composite was significantly higher in patients who underwent IVC filter placement (44.1% [45/102] vs 25% [87/348], p < 0.001). Unmatched crude logistic regression analysis identified a significant association between IVC filter placement and VTE recurrence composite (OR = 2.37; 95% CI, 1.50-3.75). Sensitivity analyses yielded congruent outcomes. CONCLUSION: This study revealed an increased risk of VTE recurrence among patients receiving IVC filter placement, suggesting that IVC filter placement may not be suitable as a primary treatment for patients with upper GI bleeding and isolated distal DVT.

A change in strategy for filter choice leads to improved filter retrieval rates.

OBJECTIVE: To assess whether a new strategy for the choice of inferior vena cava filter placed would improve filter retrieval rates at our institution. METHODS: Consecutive patients who underwent retrievable filter placement for temporary embolic protection between January 2021 and January 2023 were considered for study inclusion. Risk factors for nonretrieval of short-term filters were identified in patients receiving filters between January 2021 and January 2022 (prestrategy group). For patients treated between February 2022 and January 2023 (poststrategy group), a long-term filter was recommended for those with these risk factors, and a short-term filter was recommended for those without these risk factors. RESULTS: The study population included 303 patients (prestrategy group, n = 154; poststrategy group, n = 149). Long-term immobilization (odds ratio [OR] = 38.000; 95% confidence interval [CI]: 6.858-210.564), active cancer (OR = 17.643; 95% CI: 5.462-56.993), and venous thromboembolism detected in the intensive care unit (OR = 28.500; 95% CI: 7.419-109.477) were identified as independent risk factors for nonretrieval of short-term filters. The total retrieval rate was significantly higher in the poststrategy group (87.2%) than in the prestrategy group (72.7%; P = 0.002); the short-term filter retrieval rate was also significantly higher in the poststrategy group (84.5%) than in the prestrategy group (68.5%; P < 0.001). CONCLUSION: The proposed strategy for filter choice based on risk factors for short-term filter nonretrieval can accurately identify patients who need long-term filter placement while also increasing the retrieval rates for both short-term filters retrieval rates and overall retrieval rates.

Characteristics of Option and Denali Inferior Vena Cava Filters.

BACKGROUND: To assess the characteristics of Option and Denali filters and to identify associations between these characteristics in each filter type. METHODS: Consecutive patients who underwent Option or Denali filter placement between August 2019 and August 2022 were included in this retrospective study. RESULTS: A total of 119 patients (Option, n = 60; Denali, n = 59) were included. The retrieval rates were 45.0% for Option filters and 40.7% for Denali filters. The incidence of tilt at placement was higher for Option filters (76.7%) than for Denali filters (11.9%; P < 0.001). The tilt angle of Option filters at placement was correlated with the common iliac vein-inferior vena cava (CIV-IVC) angle. The incidence of tilt angle change after placement was higher for Option filters (74.1%) than for Denali filters (8.3%; P = 0.001). The IVC contraction rate after retrieval of Option is less than Denali (22.2% vs. 87.5%, P < 0.001). The median fluoroscopy time during Option filter retrieval was longer than during Denali filter retrieval. The fluoroscopic time was related to tilt angle during retrieval of Option filters. CONCLUSIONS: Option filters are more likely than Denali filters to tilt at placement, and the tilt angle of Option filters is more prone to change after placement. The tilt angle at placement in Option filters is related to the CIV-IVC angle. Option filters require a longer fluoroscopic time during retrieval than Denali filters, and this increased fluoroscopic time is related to the tilt angle. Denali is more likely to cause IVC constriction after placement.

Application of the Double Series Filter Technique for the Treatment of Acute Inferior Vena Cava Filter-Mediated Thrombosis.

BACKGROUND: In this study, we examined the safety and effectiveness of removing inferior vena cava (IVC) filters with residual acute thrombosis after endovascular therapy. METHODS: A retrospective chart review of 712 patients who underwent retrievable IVC filter implantation between July 2018 and December 2022 was conducted. Residual thrombosis with the IVC filter occurred in 18 patients, and the volume of residual acute thrombosis in the IVC filter exceeded 1 mL in all cases. Angiography was performed to evaluate the size of the residual thrombosis and its position with respect to the filter. The double series filter technique (first filter, infrarenal IVC filter; second filter, suprarenal IVC filter) was used to remove the filter and thrombosis. We summarize the diagnosis, treatment, and surgical experience of these patients. RESULTS: In this study, 16 of 18 patients (88.9%) demonstrated residual thrombosis in the IVC filter. One patient (5.6%) demonstrated thrombosis located both inside and floating above the filter, and one patient (5.6%) demonstrated thrombosis located both inside and underneath the filter. The technical success rate of double series IVC filter retrieval was 100%. Seventeen patients (94.4%) underwent single-stage suprarenal IVC filter retrieval, and one patient (5.6%, 1/18) underwent two-stage retrieval. In terms of residual thrombosis removal, 14 patients (77.7%) achieved complete removal and 4 patients (22.3%) achieved partial removal. Residual thrombosis could not be removed through the sheath in one patient, so femoral vein thrombectomy was performed. No other procedure-related complications were observed. The median follow-up time was 22.5 ± 6.8 months. No recurrence of thrombus symptoms was reported, and B ultrasound and computed tomography demonstrated smooth blood flow in the IVC, renal veins, and pulmonary artery. CONCLUSIONS: For patients with residual acute thrombosis on the IVC filter and in whom there was absence of a more appropriate treatment after percutaneous mechanical thrombectomy or catheter-directed thrombolysis therapy, the double series IVC filter technique was a safe approach to improve the IVC filter retrieval rate in the early stage, as well as for simultaneous residual thrombus removal.

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.

Temporary inferior vena cava filters factors associated with non-removal.

OBJECTIVES: Inferior vena cava filter (IVCF) placement is indicated when there is a deep vein thrombosis and/or a pulmonary embolism and a contraindication of anticoagulation. Due to the increased risk of recurrent deep venous thrombosis when left in place, IVCF removal is indicated once anticoagulant treatment can be reintroduced. However, many temporary IVCF are not removed. We aimed to analyze the removal rate and predictors of filter non-removal in a university hospital setting. METHODS: We collected all the data of consecutive patients who had a retrievable IVCF inserted at the Saint-Etienne University Hospital (France) between April 2012 and November 2019. Rates of filter removal were calculated. We analyzed patient characteristics to assess factors associated with filter non-removal, particularly in patients without a definitive filter indication. The exclusion of this last category of patients allowed us to calculate an adjusted removal rate. RESULTS: The overall removal rate of IVCF was 40.5% (IC 95% 35.6-45.6), and the adjusted removal rate was 62.9 % (IC 95% 56.6-69.2%). No major complications were noted. Advanced age (p < 0.0001) and cancer presence (p < 0.003) were statistically significant predictors of patients not being requested to make a removal attempt. CONCLUSIONS: Although most of the filters placed are for therapeutic indications validated by scientific societies, the removal rate in this setting remains suboptimal. The major factors influencing IVCF removal rate are advanced age and cancer presence. KEY POINTS: • Most vena cava filters are placed for therapeutic indications validated by scientific societies. • Vena cava filter removal rates in this setting remain suboptimal. • Major factors influencing IVCF removal rate are advanced age and cancer presence.

Grasp-and-Fold Technique for Complex Inferior Vena Cava Filter Retrieval.

This study evaluated the use of the grasp-and-fold technique for complex forceps retrieval of inferior vena cava (IVC) filters. A retrospective study of 14 patients (12 women and 2 men) who had either deeply tip-embedded or severely distorted IVC filters was performed at a single institution over 10 years. In this technique, endobronchial forceps were used to fold the filter in half to remove it through the sheath because the filter tip could not be accessed by dissection. The grasp-and-fold technique successfully removed all 14 filters. One patient had retained filter struts, which were present before the procedure. One mild and 5 moderate adverse events (AEs), including fracture fragment embolization requiring retrieval and self-limited IVC extravasation, occurred. No severe AEs occurred. In this small patient cohort, the grasp-and-fold forceps technique successfully retrieved deeply tip-embedded or distorted IVC filters with inaccessible tips.

Endobronchial Forceps Retrieval of Embedded Inferior Vena Cava Filters: Retrieval of 535 Filters at a Single Center.

PURPOSE: To report results of 16 years of using the endobronchial forceps technique to remove embedded inferior vena cava (IVC) filters. MATERIALS AND METHODS: Between January 2005 and June 2021, 534 patients (310 women and 224 men) with a mean age of 52 years (standard deviation [SD] ± 16 years) presented for complex filter retrieval of 535 tip- or strut-embedded IVC filters. Tip-embedded filters were diagnosed on rotational venography. Filters were considered strut-embedded if they were closed-cell filters with dwell times of >6 months. The filter was dissected from the IVC using rigid bronchoscopy forceps and removed through a vascular sheath. RESULTS: The endobronchial forceps technique was successful in 530 of 537 retrieval attempts on an intention-to-treat basis (98.7%); a total of 530 filters were retrieved. There were 7 failures: (a) 5 failed retrieval attempts (2 that were retrieved successfully in subsequent procedures) and (b) 2 for which retrieval was not attempted. The mean filter dwell time was 1,459 days (SD ± 1,617 days). Laser sheaths were not used for any removal. Filters included herein were 137 Celect (94 Celect and 43 Celect Platinum), 99 Günther Tulip, 72 Option (48 Option and 24 Option Elite), 68 G2, 45 G2X/Eclipse, 42 Denali, 30 OptEase, 29 Recovery, 7 Meridian, and 6 ALN with Hook filters. Thirty-four minor (6.3%) and 11 major (2%) adverse events (AEs) occurred, which did not result in permanent sequelae. CONCLUSIONS: Use of endobronchial forceps for removal of tip- and strut-embedded retrievable IVC filters is effective and has low AE rates.

Gunther Tulip Filter Strut Penetration: Benign Long-Term Follow-up.

PURPOSE: To describe the natural history of Gunther Tulip filter (GTF) strut penetration based on the computed tomography (CT)-documented distance penetrated over time and any clinical manifestations. MATERIALS AND METHODS: The records of 203 patients (mean age, 59.1 years; 59.4% men) who had had an infrarenal GTF placed for venous thromboembolism (84.2%) with contraindications to anticoagulation (95.1%) and had CT follow-up were reviewed retrospectively for clinical or imaging evidence of complications. Filter strut penetration was measured on axial images from the outer caval wall to the inner edge of the distal end of each strut. Filter strut behavior over time was modeled using a linear mixed model. RESULTS: The extent of penetration correlated positively with filter dwell time (P < .001) but plateaued at 3.3 mm at 10-year follow-up. At median 4.7-year follow-up 79.3% of patients had at least 1 strut that was >0.2 mm and 31% had a strut >3 mm from the inferior vena caval wall. The extent of strut penetration was greater at all time points for women (P = .002). Abutment or entry into an adjacent structure was identified in 183 struts of 105 (52.7%) filters; of the 80 filters with CT follow-up, 47% showed progression and 19% regressed. There were no symptoms referable to filter strut penetration. CONCLUSIONS: GTF struts often penetrate the inferior vena cava progressively; however, this tends to plateau by 10 years. The limited long-term progression and a very low incidence of symptomatic complications together support a noninterventional approach to the finding of an asymptomatic GTF strut penetration.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months.

OBJECTIVE: To determine the safety and effectiveness of vena cava filters (VCFs). METHODS: A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed. RESULTS: VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement. CONCLUSIONS: Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Cost Burden and Cost Influencers of Inferior Vena Cava Filter Placement and Retrieval among Medicare Beneficiaries with Acute Venous Thromboembolism.

PURPOSE: To examine the frequency, costs, and cost influencers of inferior vena cava filters (IVCFs) placements and retrievals among a national sample of patients using Medicare data. MATERIALS AND METHODS: This retrospective cohort study used the U.S. Medicare 100% database, a nationally representative sample of all U.S. patients aged ≥65 years, from 2014 through 2020. Procedures and clinical characteristics were identified from the diagnosis and procedure codes on Medicare claims. Beneficiaries aged ≥65 years with newly diagnosed venous thromboembolism (VTE) were identified and followed to obtain data on IVCF placements and retrievals. Data on the costs of the index IVCF procedures and any subsequent IVCF placements and retrievals were obtained. Multivariate models were used to estimate the impact of patient and clinical characteristics on costs. RESULTS: Among 501,216 patients with newly diagnosed VTE, 4,995 (1%) received an IVCF placement; of these, 1,215 (24.3%) had a retrieval procedure. Beneficiaries with IVCF placements and retrievals differed from a demographic and clinical perspective than from those without. Costs varied by the site of service, VTE acuity, and VTE type. Cost influencers included age, race, census region, service location, and VTE type. CONCLUSIONS: IVCF placement costs were driven by baseline patient characteristics (age, race, geographic residence, acute VTE diagnosis, and inpatient site of service), whereas retrieval costs were driven by age and deep vein thrombosis diagnosis. Strategies to mitigate the retrieval costs or the need to retrieve IVCFs may reduce the overall cost burden of IVCFs.

Complex Inferior Vena Cava Filter Retrievals: Success Rate and Predictors of Adverse Events at a Large Specialized Referral Center.

BACKGROUND. Specialized inferior vena cava (IVC) filter referral centers can achieve improved retrieval outcomes, potentially facilitating complex retrievals after long filter dwell times. OBJECTIVE. The purpose of this study was to determine the success rate of complex IVC filter retrievals at a large specialized IVC filter referral center and to identify predictors of adverse events during complex retrievals. METHODS. This retrospective study included patients who underwent complex IVC filter retrieval from March 2014 to June 2018 at a large regional health system with specialized complex retrieval referral centers and interventional radiologists with expertise in such procedures. Complex retrievals methods included a range of loop snare, coaxial sheath, forceps, and snare techniques. Data were collected from the electronic medical record. The success rate of complex retrieval was determined. Factors associated with adverse events during retrieval procedures were explored. RESULTS. The study included 125 patients (51 women, 74 men; mean age, 60 years). The mean filter dwell time at retrieval was 47.5 months (median, 21.8 months). The complex retrieval success rate was 99.2% on the first attempt and 100.0% overall. A total of 11.2% (14/125) of patients experienced an adverse event during retrieval, including 10.4% (13/125) with minor and 0.8% (1/125) with major events. Prolonged dwell time was the only indication for complex retrieval that was significantly associated with adverse events (adverse event rate, 16.7% for patients with this indication vs 5.1% for patients without this indication; p = .04). In multiple regression analysis, the only significant independent predictor of adverse events was a filter dwell time of 5 years or longer (odds ratio, 6.98 [95% CI, 1.64-29.81]; p = .009). CONCLUSION. In a specialized referral system with expertise in complex retrieval methods, high retrieval success rates can be achieved in patients who have filters with long dwell times. Nonetheless, longer dwell times are associated with adverse events during retrieval procedures. CLINICAL IMPACT. The observations support performing early filter retrieval and referring patients who have filters with prolonged dwell times to specialized centers.

Prophylactic Inferior Vena Cava Filters for Venous Thromboembolism in Adults With Trauma: An Updated Systematic Review and Meta-Analysis.

Background: Trauma is an independent risk factor for venous thromboembolism (VTE). Due to contraindications or delay in starting pharmacological prophylaxis among trauma patients with a high risk of bleeding, the inferior vena cava (IVC) filter has been utilized as alternative prevention for pulmonary embolism (PE). Albeit, its clinical efficacy has remained uncertain. Therefore, we performed an updated systematic review and meta-analysis on the effectiveness and safety of prophylactic IVC filters in severely injured patients. Methods: Three databases (MEDLINE, EMBASE, and Cochrane) were searched from August 1, 2012, to October 27, 2021. Independent reviewers performed data extraction and quality assessment. Relative risk (RR) at 95% confidence interval (CI) pooled in a randomized meta-analysis. A parallel clinical practice guideline committee assessed the certainty of evidence using the GRADE approach. The outcomes of interest included VTE, PE, deep venous thrombosis, mortality, and IVC filter complications. Results: We included 10 controlled studies (47 140 patients), of which 3 studies (310 patients) were randomized controlled trials (RCTs) and 7 were observational studies (46 830 patients). IVC filters demonstrated no significant reduction in PE and fatal PE (RR, 0.27; 95% CI, 0.06-1.28 and RR, 0.32; 95% CI, 0.01-7.84, respectively) by pooling RCTs with low certainty. However, it demonstrated a significant reduction in the risk of PE and fatal PE (RR, 0.25; 95% CI, 0.12-0.55 and RR, 0.09; 95% CI, 0.011-0.81, respectively) by pooling observational studies with very low certainty. IVC filter did not improve mortality in both RCTs and observational studies (RR, 1.44; 95% CI, 0.86-2.43 and RR, 0.63; 95% CI, 0.3-1.31, respectively). Conclusion: In trauma patients, moderate risk reduction of PE and fatal PE was demonstrated among observational data but not RCTs. The desirable effect is not robust to outweigh the undesirable effects associated with IVC filter complications. Current evidence suggests against routinely using prophylactic IVC filters.

Intravascular Tumor Extension and Pulmonary Tumor Embolism in Children With Solid Malignancies: Is There a Role for Inferior Vena Cava Filters?

Intravascular tumor extension is an uncommon complication of solid malignancies that, when present in the inferior vena cava (IVC), can result in fatal pulmonary tumor embolism. Currently, neoadjuvant chemotherapy and surgery are the mainstays of treatment; however, there are no consensus guidelines for management. We describe three cases of pediatric solid malignancies with associated IVC extension and pulmonary tumor embolism. We hypothesize that there is scope for IVC filter placement in such cases to mitigate the risk of fatal pulmonary tumor embolism.

Which caval diameter? Clarification manufacturer's instructions for inferior vena cava filter use and implications for practice.

AIM: To clarify manufacturer's instructions for inferior vena cava (IVC) filter use and implications for practice. MATERIALS AND METHODS: Three vendors of IVC filters were contacted for clarification, with all stating that caval diameter limits are to be true maximum and true minimum cross-sectional diameters. To determine the implications of this, measurements were performed on 302 abdominal computed tomography studies in four transaxial dimensions perpendicular to the long axis including true maximum and minimum diameters, and measurements reflecting those typically taken on fluoroscopic cavography. RESULTS: Based on the true maximum and true minimum caval diameter limits as clarified by vendors, 22% of patients who would typically be considered suitable for IVC filter insertion based on frontal and lateral fluoroscopic cavography would be contraindicated, and 40% of patients who would typically be considered suitable for IVC filter insertion based on only frontal fluoroscopic cavography (as lateral projection is often not performed) would be contraindicated. CONCLUSION: There is a marked discordance between the vendor-clarified caval diameter limits of three common IVC filter devices and real-world caval geometry. Given the rarity of complications, this suggests a pressing need for revision of manufacturers' instructions for use statements to better reflect current safe routine clinical use, particularly from a medicolegal perspective.