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Inferior Vena Cava Filter Placement and Retrieval Rates among Radiologists and Nonradiologists
EDUCATION, ECONOMICS, AND WORKFORCE
Inferior Vena Cava Filter Placement and Retrieval Rates among Radiologists and Nonradiologists David Guez, MD, David R. Hansberry, MD, PhD, David J. Eschelman, MD, Carin F. Gonsalves, MD, Laurence Parker, PhD, Vijay M. Rao, MD, and David C. Levin, MD ABSTRACT Purpose: To evaluate inferior vena cava (IVC) filter placement and retrieval rates among radiologists, vascular surgeons, cardiologists, other surgeons, and all other health care providers for Medicare fee-for-service beneficiaries in the years 2012–2015. Materials and Methods: The nationwide Medicare Physician/Supplier Procedure Summary Master Files were used to determine the volume and utilization rate of IVC filter placement, IVC filter repositioning, and IVC filter retrieval, which correspond to procedure codes 37191, 37192, and 37193, respectively. Procedural code 37193 was not available before 2012, so data were reviewed for the years 2012–2015. Results: The total volume of Medicare IVC filter placement decreased from 57,785 in 2012 to 44,378 in 2015, with radiologists responsible for 60% of all filter placements. Volume of IVC filter placement declined across all specialties, including radiologists, who placed 33,744 in 2012 and 27,957 in 2015. In contrast, total retrieval of IVC filters increased from 4,060 removals in 2012 to 6,166 in 2015. Retrieval rate per 100,000 Medicare beneficiaries increased from 11 in 2012 to 16 in 2015. Radiologists removed the bulk of the filters: 64% in both 2012 and 2015. Vascular surgeons, cardiologists, and other surgeons retrieved, respectively, 20%, 10%, and 5% of all IVC filters in 2012 and 22%, 9%, and 5% in 2015. Conclusions: From 2012 to 2015, IVC filter placement steadily decreased across all specialties. Retrieval rate of IVC filters continued to rise over the same period. Radiologists were responsible for the majority of IVC filter placements and retrievals.
ABBREVIATIONS FDA ¼ US Food and Drug Administration, IVC ¼ inferior vena cava, PE ¼ pulmonary embolism
Pulmonary embolism (PE) is a major cause of morbidity and mortality, with an estimated incidence of more than 200,000 deaths per year in the United States (1). In patients with proximal deep venous thrombosis or PE, anticoagulant therapy continues to be the recommended first-line treatment (2). When anticoagulant therapy is contraindicated, interruption of the inferior vena cava (IVC) with a filter
From the Department of Radiology, Thomas Jefferson University Hospital, 132 South 10th St, Philadelphia, PA 19107. Received July 27, 2017; final revision received November 10, 2017; accepted November 12, 2017. Address correspondence to D.G.; E-mail: [email protected] D.C.L. is a paid consultant for HealthHelp and is on the Board of Directors for Outpatient Imaging Affiliates. None of the other authors have identified a conflict of interest. © SIR, 2017 J Vasc Interv Radiol 2017; ▪:1–4 https://doi.org/10.1016/j.jvir.2017.11.008
device may need to be considered to protect the patient from a PE. This is frequently performed with the intention of ultimately removing the IVC filter. In 2003, the US Food and Drug Administration (FDA) approved retrievable filters for market use (3). At that time, retrieval rates were low. Duszak et al found that within the entire Medicare population, more than 65,000 filters were placed in 2008 and ~1.2%–5.1% removed (4). Complications related to filters left in for longer than the recommended time period have been reported, including IVC thrombosis, visceral penetration, filter fracture, filter migration, and filter embolization (5). In response to 921 adverse event reports from 2005 to 2010, the FDA published a safety communication recommending that “implanting physicians and clinicians responsible for the ongoing care of patients with retrievable IVC filters consider removing the filter as soon as protection from pulmonary embolism is no longer needed” (6). In 2014, the recommendation was amended, stating that if the patient’s
2 ▪ IVC Filter Placement and Retrieval Rate
transient risk for PE has passed, the risk/benefit profile begins to favor removal of the IVC filter 29–54 days after implantation (7). Although some manufacturer literature states that it is safe for up to 300 days (1), dwell times >90 days have been demonstrated to be a significant predictor of retrieval failure (8). In light of the repeated FDA advisory statements, there have been efforts to improve filter retrieval through creation of a dedicated IVC filter clinic (9), assignment of clinical teams to maintain an institution-specific database for aggressive follow up (10), and systematic “design-ofexperiment” projects that compare various follow-up formats by different departments (11). The purpose of the present study was to evaluate national trends among radiologists and other specialty groups in IVC filter placement, repositioning, and retrieval rates from 2012 to 2015 within the Medicare population.
MATERIALS AND METHODS The data source used was the nationwide Medicare Physician/Supplier Procedure Summary Master Files. They include more than 100 specialty codes identifying providers and the procedures they performed. The database covers 37.5 million fee-for-service beneficiaries, but not those in Medicare Advantage plans. Current Procedural Terminology, 4th Edition (CPT-4) codes 37191, 37192, and 37193 were queried, corresponding to IVC filter placement, IVC filter repositioning, and IVC filter retrieval, respectively. Data were reviewed for all years that procedural code 37193 was available, ie, 2012–2015, because this code was not available before 2012. The 2016 data were not yet available. For each CPT-4 code queried, yearly volume and rate (per 100,000 Medicare beneficiaries) were calculated with the use of the Medicare Advantage State-County market penetration files and then further delineated to determine if the procedures were performed by radiologists, cardiologists, vascular surgeons, or other surgeons (which encompasses all other surgeons besides vascular surgeons). Trends in performance of these procedures were compared among these specialties and within these conditions; 95% confidence intervals (CIs) for rates of filter placement and retrieval were calculated. In addition, a Cochran-Armitage nonparametric test of trend was calculated for the 4-year trends in filter placement, retrieval, and repositioning. Analyses were conducted with the use of SAS version 9.4 for Windows (SAS Institute, Cary, North Carolina). The Medicare Physician/Supplier Procedure Summary Master Files are government-published, anonymized, aggregated data sets that do not follow individual patients or outcomes; they are therefore exempt from the requirement for Institutional Review Board approval.
RESULTS The total volume of IVC filter insertion procedures within the Medicare population, across all specialties, decreased
Guez et al ▪ JVIR
Figure 1. Total volume of IVC filters placed and retrieved from 2012 to 2015.
each year from 57,785 in 2012 to 44,378 in 2015, whereas retrieval procedures increased from 4,060 in 2012 to 6,166 in 2015 (Fig 1). Total volume of IVC filter repositioning was substantiantially lower than IVC filter placement or retrieval. In 2012, there were 122 IVC filters repositioned within the Medicare fee-for-service population. This number steadily decreased year to year, with 73 repositioning procedures performed in 2013, 57 in 2014, and 38 in 2015. The volume of IVC filter repositioning was so small that no further analysis was done. IVC filter placement rate decreased from 156 procedures per 100,000 Medicare beneficiaries in 2012 (95% CI 154.7– 157.3) to 141 in 2013 (95% CI 139.8–142.2), 129 in 2014 (95% CI 127.8–130.2), and 118 in 2015 (95% CI 116.9– 119.1). IVC filter retrieval rate increased from 11 in 2012 (95% CI 10.7–11.3) to 12 in 2013 (95% CI 11.6–12.4), 14 in 2014 (95% CI 13.6–14.4), and 16 in 2015 (95% CI 15.6– 16.4; Fig 2). In addition, Cochran-Armitage nonparametric tests of trend for rate over years were computed, and were significant for both values (z ¼ 2.8283; P < .0047). The volume of filter insertion procedures decreased each year within each specialty. Radiologists dropped from a volume of 33,744 placements to 27,957, cardiologists from 4,943 to 3,621, vascular surgeons from 11,040 to 7,915, and other surgeons from 7,197 to 4,299 (Fig 3). Each specialty increased filter retrieval procedures performed from 2012 to 2015, except for other surgeons, in which filter retrievals decreased from 237 in 2013 to 221 in 2014 (Fig 4). Radiologists were responsible for the majority of IVC filter removal procedures: 64% in both 2012 and 2015. Vascular surgeons performed 20% of all filter removal procedures in 2012, increasing to 22% in 2015, cardiologists decreased from 10% in 2012 to 9% in 2015, and other surgeons remained steady at 5% in 2012 and 2015. During the 4 years queried, radiologists were responsible for 60% (122,321 out of 202,900) of the total number of IVC filter placement procedures performed within the Medicare
Volume ▪ ▪ Number ▪ ▪ Month ▪ 2017
3
procedures to placements across the entire Medicare fee-forservice population were 7%, 9%, 11%, and 14%. Trends were mostly similar in radiologists and nonradiologists. During the years studied, radiologists’ ratios of removal procedure compared with placement were 8%, 9%, 11%, and 14%, cardiologists’ were 9%, 10%, 13%, and 15%, and vascular surgeons’ were 7%, 10%, 13%, and 17%. Other surgeons trailed, with ratios of 3%, 4%, 4%, and 7%, in 2012, 2013, 2014, and 2015, repectively.
DISCUSSION Figure 2. Utilization of IVC filter placement and retrieval per 100,000 Medicare beneficiaries from 2012 to 2015.
Figure 3. Total volume of IVC filters placed per specialty from 2012 to 2015.
Figure 4. Total volume of IVC filters retrieved per 100,000 Medicare beneficiaries per specialty from 2012 to 2015.
population. In addition, radiologists collectively performed 63% (12,633 out of 20,004) of the filter removal procedures in the Medicare population from 2012 to 2015. The ratio of IVC filters retrieved compared with IVC filters placed continued to increase each year across all specialties. From 2012 to 2015, the ratios of filter removal
From 2012 to 2015, there was a steady decrease in the total volume of IVC filter placements within the Medicare population. A similar trend was recently analyzed by Wadhwa et al and Ahmed et al (12,13). Both groups analyzed the Healthcare Cost and Utilization Project National Inpatient Sample, noting filter placement moving from positive to negative use in 2010. This corresponded to the year the FDA released the first of 2 advisory statements recommending filter removal once the indication for protection from PE has passed (6). Wadhwa et al also theorized additional causes for the continuing downward trend in filter placement, citing updated guidelines by the American Heart Association in 2011 and the American College of Chest Physicians in 2012, as well as the incorporation of legal cases into multidistrict litigations in 2014 (12). This downward trend in filter placement was also noted within each of the specialties queried for 2012–2015. From 2012 to 2015, both total volume and total rate of IVC filter removal procedures increased and total volume and rate of IVC filter placement decreased. These are not chance effects: The CIs do not overlap, and the test of trend is significant. This is also demonstrated within each specialty queried, with radiologists performing almost twothirds of the total removal procedures within the Medicare population. Because IVC filter retrieval received an official CPT-4 code only in 2012, it can not be retrospectively analyzed accurately within the Medicare population to the time of the FDA advisory in 2010. However, efforts such as the creation of a dedicated IVC filter clinic (9) and systematic “design-of-experiment” projects comparing patient correspondence and follow-up (11) have demonstrated success in increasing local filter retrieval rates. It is programs such as these that reflect this improving trend in adherence to the original FDA recommendation of 2010. There are inherent limitations in our methodology of using the nationwide Medicare Physician/Supplier Procedure Summary Master Files. The CPT code for IVC filter placement does not distinguish between retrievable and permanent IVC filters, and analysis can not be performed regarding which filters are placed without intention of removal. In addition to placement of a permanent filter, Lynch’s series of 1,127 patients noted a subset in which a retrievable filter was placed with temporary intention, yet after rigorous follow-up 17.9% were determined to require permanent placement (14). Furthermore, extrapolation of
4 ▪ IVC Filter Placement and Retrieval Rate
this data to a longer time period is limited, because no CPT code specific to IVC filter retrieval existed before 2012, and 2016 data were not yet available. A previous analysis of filter retrieval within the Medicare population substituted “intravascular foreign body retrieval” as a surrogate marker to estimate these numbers (4). Because our study population includes only the Medicare fee-for-service population of the United States (excluding Medicare Advantage), we did not evaluate procedures performed for the non-Medicare population. In those younger and commercially insured patients, there may be different thresholds for IVC filter placement, thereby initiating a different follow-up protocol. In addition, our dataset could report only what type of physician billed for the procedure, and therefore we had no ability to determine if the physician retrieving a filter was the same physician who placed the filter. In summary, from 2012 to 2015, the placement of IVC filters has steadily decreased across all specialties. Over that same period, there has been an increase in the number of IVC filters retrieved. The percentage of filters that are removed remains low. Radiologists continue to be responsible for the placement and retrieval of the majority of IVC filters.
REFERENCES 1. Sarosiek S, Crowther M, Sloan M. Indications, complications, and management of inferior vena cava filters: the experience in 952 patients at an academic hospital with a level I trauma center. JAMA Intern Med 2013; 173:513–517.
Guez et al ▪ JVIR
2. Kearon C, Akl EA, Ornelas J. Antithrombotic therapy for VTE disease. CHEST Guideline and Expert Panel Report. Chest 2016; 149:315–352. 3. Ni H, Win LL. Retrievable inferior vena cava filters for venous thromboembolism. ISRN Radiol 2013;959452. 4. Duszak R, Parker L, Levin DC. Placement and removal of inferior vena cava filters: national trends in the medicare population. J Am Coll Radiol 2011; 8:483–489. 5. Morales JP, Li X, Irony TZ. Decision analysis of retrievable inferior vena cava filters in patients without pulmonary embolism. Vasc Surg Venous Lymphat Disord 2013; 1:376–384. 6. Food and Drug Administration. Removing retrievable inferior vena cava filters: initial communication. August 9, 2010. Available at: https://wayback. archive-it.org/7993/20161022180008/http:/www.fda.gov/MedicalDevices/ Safety/AlertsandNotices/ucm221676.htm. Accessed April 20, 2016. 7. Food and Drug Administration. Removing retrievable inferior vena cava filters: FDA safety communication. May 6, 2014. Available at: https://wayback. archive-it.org/7993/20170404182212/https://www.fda.gov/MedicalDevices/ Safety/AlertsandNotices/ucm396377.htm. Accessed April 20, 2016. 8. Avgerinos ED, Bath J, Stevens J. Technical and patient-related characteristics associated with challenging retrieval of inferior vena cava filters. Eur Soc Vasc Endovasc Surg 2013; 46:353–359. 9. Minocha J, Idakoji I, Riaz A. Improving inferior vena cava filter retrieval rates: impact of a dedicated inferior vena cava filter clinic. J Vasc Interv Radiol 2010; 21:1847–1851. 10. Gasparis AP, Spentzouris G, Meisner RJ. Improving retrieval rates of temporary inferior vena cava filters. J Vasc Surg 2011; 54:34S–38S. 11. Makary MS, Shah SH, Warhadpande S. Design-of-experiments approach to improving inferior vena cava filter retrieval rates. J Am Coll Radiol 2017; 14:72–77. 12. Ahmed O, Patel K, Patel M. Declining national annual IVC filter utilization: an analysis on the impact of societal and governmental communications. Chest 2017; 151:1402–1404. 13. Wadhwa V, Trivedi PS, Chatterjee K. Decreasing utilization of inferior vena cava filters in post-FDA warning era: insights from 2005–2014 Nationwide Inpatient Sample. J Am Coll Radiol 2017; 14:1144–1150. 14. Lynch F. A Method for following patients with retrievable inferior vena cava filters: results and lessons from the first 1,100 patients. J Vasc Intervent Radiol 2011; 22:1507–1512.
Inferior Vena Cava Filter Placement and Retrieval Rates among Radiologists and Nonradiologists David Guez, MD, David R. Hansberry, MD, PhD, David J. Eschelman, MD, Carin F. Gonsalves, MD, Laurence Parker, PhD, Vijay M. Rao, MD, and David C. Levin, MD ABSTRACT Purpose: To evaluate inferior vena cava (IVC) filter placement and retrieval rates among radiologists, vascular surgeons, cardiologists, other surgeons, and all other health care providers for Medicare fee-for-service beneficiaries in the years 2012–2015. Materials and Methods: The nationwide Medicare Physician/Supplier Procedure Summary Master Files were used to determine the volume and utilization rate of IVC filter placement, IVC filter repositioning, and IVC filter retrieval, which correspond to procedure codes 37191, 37192, and 37193, respectively. Procedural code 37193 was not available before 2012, so data were reviewed for the years 2012–2015. Results: The total volume of Medicare IVC filter placement decreased from 57,785 in 2012 to 44,378 in 2015, with radiologists responsible for 60% of all filter placements. Volume of IVC filter placement declined across all specialties, including radiologists, who placed 33,744 in 2012 and 27,957 in 2015. In contrast, total retrieval of IVC filters increased from 4,060 removals in 2012 to 6,166 in 2015. Retrieval rate per 100,000 Medicare beneficiaries increased from 11 in 2012 to 16 in 2015. Radiologists removed the bulk of the filters: 64% in both 2012 and 2015. Vascular surgeons, cardiologists, and other surgeons retrieved, respectively, 20%, 10%, and 5% of all IVC filters in 2012 and 22%, 9%, and 5% in 2015. Conclusions: From 2012 to 2015, IVC filter placement steadily decreased across all specialties. Retrieval rate of IVC filters continued to rise over the same period. Radiologists were responsible for the majority of IVC filter placements and retrievals.
ABBREVIATIONS FDA ¼ US Food and Drug Administration, IVC ¼ inferior vena cava, PE ¼ pulmonary embolism
Pulmonary embolism (PE) is a major cause of morbidity and mortality, with an estimated incidence of more than 200,000 deaths per year in the United States (1). In patients with proximal deep venous thrombosis or PE, anticoagulant therapy continues to be the recommended first-line treatment (2). When anticoagulant therapy is contraindicated, interruption of the inferior vena cava (IVC) with a filter
From the Department of Radiology, Thomas Jefferson University Hospital, 132 South 10th St, Philadelphia, PA 19107. Received July 27, 2017; final revision received November 10, 2017; accepted November 12, 2017. Address correspondence to D.G.; E-mail: [email protected] D.C.L. is a paid consultant for HealthHelp and is on the Board of Directors for Outpatient Imaging Affiliates. None of the other authors have identified a conflict of interest. © SIR, 2017 J Vasc Interv Radiol 2017; ▪:1–4 https://doi.org/10.1016/j.jvir.2017.11.008
device may need to be considered to protect the patient from a PE. This is frequently performed with the intention of ultimately removing the IVC filter. In 2003, the US Food and Drug Administration (FDA) approved retrievable filters for market use (3). At that time, retrieval rates were low. Duszak et al found that within the entire Medicare population, more than 65,000 filters were placed in 2008 and ~1.2%–5.1% removed (4). Complications related to filters left in for longer than the recommended time period have been reported, including IVC thrombosis, visceral penetration, filter fracture, filter migration, and filter embolization (5). In response to 921 adverse event reports from 2005 to 2010, the FDA published a safety communication recommending that “implanting physicians and clinicians responsible for the ongoing care of patients with retrievable IVC filters consider removing the filter as soon as protection from pulmonary embolism is no longer needed” (6). In 2014, the recommendation was amended, stating that if the patient’s
2 ▪ IVC Filter Placement and Retrieval Rate
transient risk for PE has passed, the risk/benefit profile begins to favor removal of the IVC filter 29–54 days after implantation (7). Although some manufacturer literature states that it is safe for up to 300 days (1), dwell times >90 days have been demonstrated to be a significant predictor of retrieval failure (8). In light of the repeated FDA advisory statements, there have been efforts to improve filter retrieval through creation of a dedicated IVC filter clinic (9), assignment of clinical teams to maintain an institution-specific database for aggressive follow up (10), and systematic “design-ofexperiment” projects that compare various follow-up formats by different departments (11). The purpose of the present study was to evaluate national trends among radiologists and other specialty groups in IVC filter placement, repositioning, and retrieval rates from 2012 to 2015 within the Medicare population.
MATERIALS AND METHODS The data source used was the nationwide Medicare Physician/Supplier Procedure Summary Master Files. They include more than 100 specialty codes identifying providers and the procedures they performed. The database covers 37.5 million fee-for-service beneficiaries, but not those in Medicare Advantage plans. Current Procedural Terminology, 4th Edition (CPT-4) codes 37191, 37192, and 37193 were queried, corresponding to IVC filter placement, IVC filter repositioning, and IVC filter retrieval, respectively. Data were reviewed for all years that procedural code 37193 was available, ie, 2012–2015, because this code was not available before 2012. The 2016 data were not yet available. For each CPT-4 code queried, yearly volume and rate (per 100,000 Medicare beneficiaries) were calculated with the use of the Medicare Advantage State-County market penetration files and then further delineated to determine if the procedures were performed by radiologists, cardiologists, vascular surgeons, or other surgeons (which encompasses all other surgeons besides vascular surgeons). Trends in performance of these procedures were compared among these specialties and within these conditions; 95% confidence intervals (CIs) for rates of filter placement and retrieval were calculated. In addition, a Cochran-Armitage nonparametric test of trend was calculated for the 4-year trends in filter placement, retrieval, and repositioning. Analyses were conducted with the use of SAS version 9.4 for Windows (SAS Institute, Cary, North Carolina). The Medicare Physician/Supplier Procedure Summary Master Files are government-published, anonymized, aggregated data sets that do not follow individual patients or outcomes; they are therefore exempt from the requirement for Institutional Review Board approval.
RESULTS The total volume of IVC filter insertion procedures within the Medicare population, across all specialties, decreased
Guez et al ▪ JVIR
Figure 1. Total volume of IVC filters placed and retrieved from 2012 to 2015.
each year from 57,785 in 2012 to 44,378 in 2015, whereas retrieval procedures increased from 4,060 in 2012 to 6,166 in 2015 (Fig 1). Total volume of IVC filter repositioning was substantiantially lower than IVC filter placement or retrieval. In 2012, there were 122 IVC filters repositioned within the Medicare fee-for-service population. This number steadily decreased year to year, with 73 repositioning procedures performed in 2013, 57 in 2014, and 38 in 2015. The volume of IVC filter repositioning was so small that no further analysis was done. IVC filter placement rate decreased from 156 procedures per 100,000 Medicare beneficiaries in 2012 (95% CI 154.7– 157.3) to 141 in 2013 (95% CI 139.8–142.2), 129 in 2014 (95% CI 127.8–130.2), and 118 in 2015 (95% CI 116.9– 119.1). IVC filter retrieval rate increased from 11 in 2012 (95% CI 10.7–11.3) to 12 in 2013 (95% CI 11.6–12.4), 14 in 2014 (95% CI 13.6–14.4), and 16 in 2015 (95% CI 15.6– 16.4; Fig 2). In addition, Cochran-Armitage nonparametric tests of trend for rate over years were computed, and were significant for both values (z ¼ 2.8283; P < .0047). The volume of filter insertion procedures decreased each year within each specialty. Radiologists dropped from a volume of 33,744 placements to 27,957, cardiologists from 4,943 to 3,621, vascular surgeons from 11,040 to 7,915, and other surgeons from 7,197 to 4,299 (Fig 3). Each specialty increased filter retrieval procedures performed from 2012 to 2015, except for other surgeons, in which filter retrievals decreased from 237 in 2013 to 221 in 2014 (Fig 4). Radiologists were responsible for the majority of IVC filter removal procedures: 64% in both 2012 and 2015. Vascular surgeons performed 20% of all filter removal procedures in 2012, increasing to 22% in 2015, cardiologists decreased from 10% in 2012 to 9% in 2015, and other surgeons remained steady at 5% in 2012 and 2015. During the 4 years queried, radiologists were responsible for 60% (122,321 out of 202,900) of the total number of IVC filter placement procedures performed within the Medicare
Volume ▪ ▪ Number ▪ ▪ Month ▪ 2017
3
procedures to placements across the entire Medicare fee-forservice population were 7%, 9%, 11%, and 14%. Trends were mostly similar in radiologists and nonradiologists. During the years studied, radiologists’ ratios of removal procedure compared with placement were 8%, 9%, 11%, and 14%, cardiologists’ were 9%, 10%, 13%, and 15%, and vascular surgeons’ were 7%, 10%, 13%, and 17%. Other surgeons trailed, with ratios of 3%, 4%, 4%, and 7%, in 2012, 2013, 2014, and 2015, repectively.
DISCUSSION Figure 2. Utilization of IVC filter placement and retrieval per 100,000 Medicare beneficiaries from 2012 to 2015.
Figure 3. Total volume of IVC filters placed per specialty from 2012 to 2015.
Figure 4. Total volume of IVC filters retrieved per 100,000 Medicare beneficiaries per specialty from 2012 to 2015.
population. In addition, radiologists collectively performed 63% (12,633 out of 20,004) of the filter removal procedures in the Medicare population from 2012 to 2015. The ratio of IVC filters retrieved compared with IVC filters placed continued to increase each year across all specialties. From 2012 to 2015, the ratios of filter removal
From 2012 to 2015, there was a steady decrease in the total volume of IVC filter placements within the Medicare population. A similar trend was recently analyzed by Wadhwa et al and Ahmed et al (12,13). Both groups analyzed the Healthcare Cost and Utilization Project National Inpatient Sample, noting filter placement moving from positive to negative use in 2010. This corresponded to the year the FDA released the first of 2 advisory statements recommending filter removal once the indication for protection from PE has passed (6). Wadhwa et al also theorized additional causes for the continuing downward trend in filter placement, citing updated guidelines by the American Heart Association in 2011 and the American College of Chest Physicians in 2012, as well as the incorporation of legal cases into multidistrict litigations in 2014 (12). This downward trend in filter placement was also noted within each of the specialties queried for 2012–2015. From 2012 to 2015, both total volume and total rate of IVC filter removal procedures increased and total volume and rate of IVC filter placement decreased. These are not chance effects: The CIs do not overlap, and the test of trend is significant. This is also demonstrated within each specialty queried, with radiologists performing almost twothirds of the total removal procedures within the Medicare population. Because IVC filter retrieval received an official CPT-4 code only in 2012, it can not be retrospectively analyzed accurately within the Medicare population to the time of the FDA advisory in 2010. However, efforts such as the creation of a dedicated IVC filter clinic (9) and systematic “design-of-experiment” projects comparing patient correspondence and follow-up (11) have demonstrated success in increasing local filter retrieval rates. It is programs such as these that reflect this improving trend in adherence to the original FDA recommendation of 2010. There are inherent limitations in our methodology of using the nationwide Medicare Physician/Supplier Procedure Summary Master Files. The CPT code for IVC filter placement does not distinguish between retrievable and permanent IVC filters, and analysis can not be performed regarding which filters are placed without intention of removal. In addition to placement of a permanent filter, Lynch’s series of 1,127 patients noted a subset in which a retrievable filter was placed with temporary intention, yet after rigorous follow-up 17.9% were determined to require permanent placement (14). Furthermore, extrapolation of
4 ▪ IVC Filter Placement and Retrieval Rate
this data to a longer time period is limited, because no CPT code specific to IVC filter retrieval existed before 2012, and 2016 data were not yet available. A previous analysis of filter retrieval within the Medicare population substituted “intravascular foreign body retrieval” as a surrogate marker to estimate these numbers (4). Because our study population includes only the Medicare fee-for-service population of the United States (excluding Medicare Advantage), we did not evaluate procedures performed for the non-Medicare population. In those younger and commercially insured patients, there may be different thresholds for IVC filter placement, thereby initiating a different follow-up protocol. In addition, our dataset could report only what type of physician billed for the procedure, and therefore we had no ability to determine if the physician retrieving a filter was the same physician who placed the filter. In summary, from 2012 to 2015, the placement of IVC filters has steadily decreased across all specialties. Over that same period, there has been an increase in the number of IVC filters retrieved. The percentage of filters that are removed remains low. Radiologists continue to be responsible for the placement and retrieval of the majority of IVC filters.
REFERENCES 1. Sarosiek S, Crowther M, Sloan M. Indications, complications, and management of inferior vena cava filters: the experience in 952 patients at an academic hospital with a level I trauma center. JAMA Intern Med 2013; 173:513–517.
Guez et al ▪ JVIR
2. Kearon C, Akl EA, Ornelas J. Antithrombotic therapy for VTE disease. CHEST Guideline and Expert Panel Report. Chest 2016; 149:315–352. 3. Ni H, Win LL. Retrievable inferior vena cava filters for venous thromboembolism. ISRN Radiol 2013;959452. 4. Duszak R, Parker L, Levin DC. Placement and removal of inferior vena cava filters: national trends in the medicare population. J Am Coll Radiol 2011; 8:483–489. 5. Morales JP, Li X, Irony TZ. Decision analysis of retrievable inferior vena cava filters in patients without pulmonary embolism. Vasc Surg Venous Lymphat Disord 2013; 1:376–384. 6. Food and Drug Administration. Removing retrievable inferior vena cava filters: initial communication. August 9, 2010. Available at: https://wayback. archive-it.org/7993/20161022180008/http:/www.fda.gov/MedicalDevices/ Safety/AlertsandNotices/ucm221676.htm. Accessed April 20, 2016. 7. Food and Drug Administration. Removing retrievable inferior vena cava filters: FDA safety communication. May 6, 2014. Available at: https://wayback. archive-it.org/7993/20170404182212/https://www.fda.gov/MedicalDevices/ Safety/AlertsandNotices/ucm396377.htm. Accessed April 20, 2016. 8. Avgerinos ED, Bath J, Stevens J. Technical and patient-related characteristics associated with challenging retrieval of inferior vena cava filters. Eur Soc Vasc Endovasc Surg 2013; 46:353–359. 9. Minocha J, Idakoji I, Riaz A. Improving inferior vena cava filter retrieval rates: impact of a dedicated inferior vena cava filter clinic. J Vasc Interv Radiol 2010; 21:1847–1851. 10. Gasparis AP, Spentzouris G, Meisner RJ. Improving retrieval rates of temporary inferior vena cava filters. J Vasc Surg 2011; 54:34S–38S. 11. Makary MS, Shah SH, Warhadpande S. Design-of-experiments approach to improving inferior vena cava filter retrieval rates. J Am Coll Radiol 2017; 14:72–77. 12. Ahmed O, Patel K, Patel M. Declining national annual IVC filter utilization: an analysis on the impact of societal and governmental communications. Chest 2017; 151:1402–1404. 13. Wadhwa V, Trivedi PS, Chatterjee K. Decreasing utilization of inferior vena cava filters in post-FDA warning era: insights from 2005–2014 Nationwide Inpatient Sample. J Am Coll Radiol 2017; 14:1144–1150. 14. Lynch F. A Method for following patients with retrievable inferior vena cava filters: results and lessons from the first 1,100 patients. J Vasc Intervent Radiol 2011; 22:1507–1512.