Vena Cava Filter Placement Research Articles

Preoperative inferior vena cava filter implantation to prevent pulmonary fat embolism in a patient showing renal angiomyolipoma extension into the renal vein: A case report and literature review.

Renal angiomyolipoma without local invasion is usually considered benign entity, however, it may extend into the renal vein or the inferior vena cava. Renal angiomyolipoma with venous extension should be treated; however, surgical complications such as iatrogenic pulmonary fat embolism remain a serious concern. We present a case of a 66-year-old Japanese woman without tuberous sclerosis in whom a right-sided renal tumor was incidentally detected on ultrasonography during a health check-up. Further evaluation showed that the tumor extended into the renal vein, and she was successfully treated using preoperative inferior vena cava filter placement and radical nephrectomy. An inferior vena cava filter can prevent catastrophic pulmonary fat embolism during nephrectomy.

Inferior vena cava filter use and patient safety: legacy or science?

There has been a dramatic increase in vena cava filter (VCF) use over the past 20 years in the absence of evidence that filters provide a net patient benefit or are required in most cases. This increase is largely attributable to the availability of retrievable filters and expanded indications, particularly as primary prophylaxis in patients thought to be at high risk of pulmonary embolism. Substantial variability in VCF use, unrelated to patient clinical factors, has been shown between hospitals, from region to region, and among various countries. Despite the lack of direct evidence for the benefit of VCFs for any indication, it is appropriate to insert a retrievable VCF in patients with a recent proximal deep vein thrombosis and an absolute contraindication to therapeutic anticoagulation and then to remove the filter once the bleeding risk decreases and the patient has been anticoagulated. Unfortunately, a high proportion of retrievable filters are not removed, even after the reason for their placement has long passed. Retrievable filters are associated with substantial rates of complications if they are not removed, including penetration of the vena caval wall, fracture and embolization of filter fragments, and caval occlusion. Patient safety priorities and medical-legal concerns mandate careful selection of patients for VCF placement and removal shortly after anticoagulation has been initiated.

Outcomes and Direct Costs of Inferior Vena Cava Filter Placement and Retrieval within the IR and Surgical Settings

PurposeTo compare the outcomes and costs of inferior vena cava (IVC) filter placement and retrieval in the interventional radiology (IR) and surgical departments at a tertiary-care center. Materials and MethodsRetrospective review was performed of 142 sequential outpatient IVC filter placements and 244 retrievals performed in the IR suite and operating room (OR) from 2013 to 2016. Patient demographic data, procedural characteristics, outcomes, and direct costs were compared between cohorts. ResultsTechnical success rates of 100% were achieved for both IR and OR filter placements, and 98% of filters were successfully retrieved by IR means, compared with 83% in the OR (P < .01). Fluoroscopy time was similar for IR and OR filter insertions, but IR retrievals required half the fluoroscopy time, with an average of 9 minutes vs 18 minutes in the OR (P = .02). There was no significant difference between cohorts in the incidences of complications for filter retrievals, but more postprocedural complications were observed for OR placements (8%) vs IR placements (1%; P = .05). The most severe complication occurred during an OR filter retrieval, resulting in entanglement of the snare device and conversion to an emergent open filter removal by vascular surgery. Direct costs were approximately 20% higher for OR vs IR IVC filter placements ($2,246 vs $2,671; P = .01). ConclusionsFilter placements are equally successfully performed in IR and OR settings, but OR patients experienced significantly higher postprocedural complication rates and incurred higher costs. In contrast, higher technical success rates and shorter fluoroscopy times were observed for IR filter retrievals compared with those performed in the OR.

Deep venous thrombosis in pregnancy: incidence, pathogenesis and endovascular management.

Deep venous thrombosis (DVT) during pregnancy is associated with high mortality, morbidity, and costs. Pulmonary embolism (PE), its most feared complication, is the leading cause of maternal death in the developed world. DVT can also result in long-term complications that include postthrombotic syndrome (PTS) adding to its morbidity. Women are up to 5 times more likely to develop DVT when pregnant. The current standard of care for this condition is anticoagulation. This review discusses the epidemiology, pathogenesis, prophylaxis and diagnosis of DVT during pregnancy, and then focuses on endovascular treatment modalities. Inferior vena cava (IVC) filter placement and pharmacomechanical catheter directed thrombolysis (PCDT) in the pregnant patient are discussed, as well as patient selection criteria, and complications.

Association of Admission Glucose Level and Improvement in Pulmonary Artery Pressure in Patients with Submassive-type Acute Pulmonary Embolism.

Objective The admission glucose level is a predictor of mortality even in patients with acute pulmonary embolism (APE). However, whether or not the admission glucose level is associated with the severity of APE itself or the underlying disease of APE is unclear. Methods This study was a retrospective observational study. A pulmonary artery (PA) catheter was used to accurately evaluate the severity of APE. The percentage changes in the mean PA pressure (PAPm) upon placement and removal of the inferior vena cava filter (IVCF) were evaluated. We hypothesized that the admission glucose level was associated with the improvement in the PA pressure in patients with APE. Patients A total of consecutive 22 patients with submassive APE who underwent temporary or retrievable IVCF insertion on admission and repetitive PA catheter measurements upon placement and removal of IVCFs were enrolled. Results There was a significant positive correlation between the admission glucose levels and the percentage changes in the PAPm (r=0.543, p=0.009). A univariate linear regression analysis showed that the admission glucose level was the predictor of the percentage change in PAPm (β coefficient=0.169 per 1 mg/dL; 95% confidence interval, 0.047-0.291; p=0.009). A multivariate linear regression analysis with the forced inclusion model showed that the admission glucose level was the predictor of the percentage change in PAPm independent of diabetes mellitus, PAPm on admission, troponin positivity, and brain natriuretic peptide level (all p＜0.05). Conclusion The admission glucose level was associated with the improvement in the PAPm in patients with submassive-type APE.

Invited commentary

Dr Harris and colleagues argue that services for vascular acute care surgery (VACS) should be established in tertiary referral centers for nonelective care. Further, they speculate that additional training and advanced certification of vascular surgeons and VACS program accreditation may be required in the future. Their analyses likely overestimate the burden of emergency vascular care. The Health Services Cost Review Commission inpatient data set they reviewed provided minimal information about the nature of patients' vascular conditions and procedures. As expected, urgent or emergency hospitalization was associated with greater resource utilization and poorer outcomes. The analysis, however, could not determine whether vascular disease or injury was the reason for admission or whether vascular procedures were needed during hospitalization to address complications or comorbidities. Vascular diagnoses were not specified, nor was the urgency of procedures performed. Many nonelective hospital admissions for vascular diagnoses are not true emergencies. Emergency Department cases may become “acute” because of lack of insurance, inadequate primary care, or because of a primary care provider's choice to first send the patient to the Emergency Department for management. All board-certified vascular surgeons, regardless of their training pathway, should be competent to handle most nonelective problems, including thromboembolectomy, vascular access procedures, angiography, inferior vena cava filter placements, amputations, treatment of pseudoaneurysms, and the like. These procedures should not require transfer to an acute vascular care center. Complex care is already regionalized to larger centers. There are 5564 United States hospitals,1American Hospital Association AHA Hospital Statistics. Fast facts on US hospitals.http://www.aha.org/research/rc/stat-studies/fast-facts.shtmlGoogle Scholar but only 3767 vascular surgeons.2American Board of Surgery Statistics and pass rates.http://www.absurgery.org/default.jsp?statsummaryGoogle Scholar The need for triage and transfer should be considered the norm. Although there can be problems with access to care and timeliness of transfer, it is unlikely that establishing VACS teams at regional centers will be the answer. Interestingly, our group at a medium-sized academic medical center (a level 1 trauma center) instituted an acute vascular surgery care service. We found the change unhelpful. After a 1-year trial, we reverted to our traditional coverage model. We still handle ruptured aneurysms, acute limb ischemia, and other complex vascular problems, but without a service dedicated to acute problems. Implementation a VACS service may make sense where most of the work is urgent or an emergency. That does not mean it is right for most programs. Management of clinical services needs to be based on referral patterns, local resources, and institutional priorities, not national directives. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery. Defining the burden, scope, and future of vascular acute care surgeryJournal of Vascular SurgeryVol. 66Issue 5PreviewThe paradigm of acute care surgery has revolutionized nonelective general surgery. Similarly, nonelective vascular surgery may benefit from specific management and resource capabilities. To establish the burden and scope of vascular acute care surgery, we analyzed the characteristics and outcomes of patients hospitalized for vascular surgical procedures in Maryland. Full-Text PDF Open Archive

Outcomes after inferior vena cava filter placement in cancer patients diagnosed with pulmonary embolism: risk for recurrent venous thromboembolism.

Venous thromboembolism (VTE) is a common complication in cancer patients and anticoagulation (AC) remains the standard of care for treatment. Inferior vena cava (IVC) filters may also used to reduce the risk of pulmonary embolism, either alone or in addition to AC. Although widely used, data are limited on the safety and efficacy of IVC filters in cancer patients. We performed a retrospective review of outcomes after IVC filter insertion in a database of 1270 consecutive patients with cancer-associated pulmonary embolism (PE) at our institution between 2008 and 2009. Outcomes measured included rate of all recurrent VTE, recurrent PE, and overall survival within 12months. 317 (25%) of the 1270 patients with PE had IVC filters placed within 30days of the index PE event or prior to the index PE in the setting of prior DVT. Patients with IVC filters had markedly lower overall survival (7.3months) than the non-IVC filter patients (13.2months). Filter patients also had a lower rate of AC use at time of initial PE. There was a trend towards higher recurrent VTE in patients with IVC filters (11.9%) compared to non-filter patients (7.7%), but this was not significant (p = 0.086). The risk of recurrent PE was similar between the IVC filter cohort (3.5%) and non-filter group (3.5%, p = 0.99). Cancer patients receiving IVC filters had a similar risk of recurrent PE, but a trend towards more overall recurrent VTE. The filter patients had poorer overall survival, which may reflect a poorer cancer prognosis, and had greater contraindication to AC; therefore these patients likely had a higher inherent risk for recurrent VTE. A prospective study would be helpful for further clarification on the partial reduction in the recurrent PE risk by IVC filter placement in cancer patients.

Treatment of an Acute Limb Due to Inferior Vena Cava Filter Thrombosis

A 55-year-old man presented with profound unilateral right leg swelling. Approximately 1 month before, he had suffered a pulmonary embolism complicated by bleeding on anticoagulation, prompting placement of a retrievable inferior vena cava (IVC) filter. On this admission, ultrasound evaluation

Variables associated with pulmonary thromboembolism in injured patients: A systematic review

BackgroundPulmonary thromboembolism (PTE) is a dangerous complication of traumatic injury, with varied risk profiles and treatment options. This review aims to describe reported incidence and variables associated with PTE among severely injured patients. MethodsSearches were conducted using PubMed, Cochrane and MEDLINE. Relevant studies were identified by two independent reviewers based on predetermined inclusion criteria. Incidence of PTE was the primary outcome measure. Variables associated with PTE was the secondary outcome measure. The Newcastle-Ottawa Scale was used to assess quality of included studies. ResultsThere were eight studies that satisfied inclusion criteria. The diagnosed incidence of PTE in these populations ranged from 0.35 to 24%. The most common variables associated with PTE were pelvic or lower limb injury, chest injury, higher total Injury Severity Score, male sex and age. Variables that were less commonly associated with PTE were previous warfarin use, head injury, high serum lactate, soft tissue injury, more than one operation, more than three days on a ventilator, presence of a subclavian central venous catheter, need for a blood transfusion, systolic blood pressure <90mmHg, abdominal injury, presence of a deep venous thrombosis, inferior vena cava filter placement and isolated liver spleen or spinal injuries. ConclusionsThe reported incidence of PTE after major trauma is variable and dependent on inclusion criteria, diagnostic criteria and study design. Identified variables differed to those reported for venous thromboembolism in other populations. It is difficult to predict populations at risk of clinically significant PTE following injury using available evidence. Further studies linked to patient-specific variables will assist in more precise risk-stratification and interventions.

Early intracardiac thrombus and pulmonary embolus after trauma

Here, we present the case of a patient with the findings of an early intracardiac thrombus and a pulmonary embolus after major trauma. A large clot was identified extending from...

Money well spent? A cost and utilization analysis of prophylactic inferior vena cava filter placement in high-risk trauma patients

BackgroundInferior vena cava filters (IVCF) for venous thromboembolic prophylaxis in high-risk trauma patients is a controversial practice. Utilization of IVCF prophylaxis was evaluated at a level 1 trauma center. Daily cost of IVCF prophylaxis, time to IVCF, duration between IVCF and chemoprophylaxis, and number of patients needed to treat (NNT) to prevent pulmonary embolism (PE) was calculated. MethodsA retrospective review of prophylactic IVCF over a 5-year period (2010-2014). Demographic, physiologic, injury, procedural, and outcome data were abstracted from the administrative trauma database. Medicare fees and days without chemoprophylaxis were used to determine daily IVCF cost. NNT was calculated using PE events in a cohort without IVCF. ResultsOver the 5-year period, 146 patients with mean age 56.3 y (SD ± 24.2), 67.8% male, underwent prophylactic IVCF. Predominant mechanisms of injuries were falls (45.9%) and motor vehicle accidents (20.5%) with median Injury Severity Score of 25 (intraquartile range [IQR] 16-29) and head Abbreviated Injury Score of 3 (IQR 3-5). Most common operative interventions required in 24.7% were orthopedic (25.3%) and neurosurgical (21.9%). Median time to IVCF was 78 h (IQR 48-144). Most common IVCF indications were closed head injury (48.6%) and spinal injuries (30.8%). Median time to administration of chemoprophylaxis was 96 h after IVCF (IQR 24-192) in 57.5%. Median IVCF cost was $759/d (IQR $361-$1897) compared with $4.32 for chemoprophylaxis. PE occurred in 0.26% without IVCF. PE did not occur with prophylactic IVCF. Estimated NNT was 379 (95% CI 265, 661). ConclusionsProphylactic IVCF placement is a costly practice with relatively low benefit. Anticipated time without chemoprophylaxis and patient criteria should be considered before routine IVCF placement.

Timing of Hospital-Acquired Venous Thromboembolism (VTE) and its Relationship With VTE Prevention Measures in Immobile Patients

This study describes the timing of venous thromboembolism (VTE) diagnosis in patients with cerebral or spinal trauma and stroke and the relationships between VTE prevention and timing of VTE diagnosis at a community hospital. This was a retrospective cohort observational study over a span of 10 years. Routine ultrasound surveillance identified 138 patients (61% men; mean age, 62 years) who developed VTE during their hospital stay. Mechanical prophylaxis was used in 79.7%, and pharmacologic prophylaxis in 78.3% of patients. The average time of admission to administration of mechanical prophylaxis was 1.92 days, and was 7.7 days for pharmacologic prophylaxis. In patients who received chemical prophylaxis within 2 days, 51.5% of all VTE events occurred during the first week, 73.5% during the first 2 weeks, and 91.2% during the first 3 weeks of the hospital stay. In patients who started chemical prophylaxis after the second day in the hospital, 85% of all VTE events occurred within the first week and 90% within the first 10 days of their hospital stay. The difference was statistically significant (P < .01). The timing of initiation of mechanical prophylaxis did not influence the timing of VTE events. In addition, the placement of inferior vena cava filters (IVCF) did not influence the incidence of pulmonary embolism in patients who received pharmacologic prophylaxis (18% with IVCF; 17% without IVCF). This study suggests that VTE screening in patients with cerebral or spinal trauma and stroke may be performed at a different schedule based on the timing of initiation of pharmacologic prophylaxis. In patients who did not start prophylaxis during the first 2 days, most VTEs can be diagnosed during the first 10 days. It appears that use of IVCF in patients who received pharmacological prophylaxis does not decrease the incidence of pulmonary embolism.

Association Between Contemporary Trends in Inferior Vena Cava Filter Placement and the 2010 US Food and Drug Administration Advisory

This study uses the National Inpatient Sample database to assess the association between rates of inferior vena cava filter placement in the United States and the 2010 US FDA device safety warning.

Decreasing Utilization of Inferior Vena Cava Filters in Post-FDA Warning Era: Insights From 2005 to 2014 Nationwide Inpatient Sample

BackgroundTo determine the impact, if any, of the 2010 FDA safety communication on the rate of inferior vena cava filter (IVCF) placement over time. MethodsThe Nationwide Inpatient Sample was interrogated for the most recent years preceding and after the FDA safety communication—from 2005 to 2014. IVCF placements and associated diagnoses were identified using corresponding International Classification of Diseases, version nine codes. Trends in number of IVCF placement were evaluated in aggregate and by associated diagnoses, both of which were further stratified by hospital geographic cluster, hospital teaching status, and patient demographics. Generalized linear regression models were used to determine statistical significance of trends over time. ResultsIVCF placements steadily increased between 2005 and 2010 (100,434 in 2005 versus 129,614 in 2010, growth rate 5.81%). Aggregate IVCF placements subsequently declined between 2010 and 2014 (96,005 in 2014, decline rate −6.48%). IVCF placements peaked in 2010, the year of the FDA advisory. The proportion of filter placements for therapeutic indication of venous thromboembolism increased significantly during the study period (69.8% in 2005 versus 80.4% in 2014, P < .001). Neither trend varied significantly by patient demographics or hospital characteristics. ConclusionsIVCF placements have declined significantly since 2010, when the FDA advisory was released. The proportion of IVCFs placed in patients with venous thromboembolism, as opposed to prophylactic indications, is increasing.

Defining Prolonged Dwell Time: When Are Advanced Inferior Vena Cava Filter Retrieval Techniques Necessary? An Analysis in 762 Procedures.

Despite growth in placement of retrievable inferior vena cava filters, retrieval rates remain low. Filters with extended implantation times present a challenge to retrieval, where standard techniques often fail. The development of advanced retrieval techniques has positively impacted retrieval of retrievable inferior vena cava filters with prolonged dwell times; however, there is no precise definition of the time point when advanced techniques become necessary. We aim to define prolonged retrievable inferior vena cava filters dwell time by determining the inflection point when the risk of standard retrieval technique failure increases significantly, necessitating advanced retrieval techniques to maintain overall technical success of retrieval. From January 2009 to April 2015, 762 retrieval procedures were identified from a prospectively acquired database. We assessed patient age/sex, filter dwell time, procedural technical success, the use of advanced techniques, and procedure-related adverse events. Overall retrieval success rate was 98% (n=745). When standard retrieval techniques failed, advanced techniques were used; this was necessary 18% of the time (n=138). Logistic regression identified that dwell time was the only risk factor for failure of standard retrieval technique (odds ratio, 1.08; 95% confidence interval, 1.05-1.10; P<0.001). Spline function regression analysis demonstrated that if dwell time exceeded 7 months, the risk of standard technique failure was 40.9%. Adverse events occurred at a rate of 2% (n=18; 15 minor and 3 major). The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time. Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval.

Retrospective analysis of outcomes following inferior vena cava (IVC) filter placement in a managed care population

The role of inferior vena cava filter (IVC) filters for prevention of pulmonary embolism (PE) is controversial. This study evaluated outcomes of IVC filter placement in a managed care population. This retrospective cohort study evaluated data for individuals with Humana healthcare coverage 2013–2014. The study population included 435 recipients of prophylactic IVC filters, 4376 recipients of therapeutic filters, and two control groups, each matched to filter recipients. Patients were followed for up to 2 years. Post-index anticoagulant use, mortality, filter removal, device-related complications, and all-cause utilization. Adjusted regression analyses showed a positive association between filter placement and anticoagulant use at 3 months: odds ratio (ORs) 3.403 (95% CI 1.912–6.059), prophylactic; OR, 1.356 (95% CI 1.164–1.58), therapeutic. Filters were removed in 15.67% of prophylactic and 5.69% of therapeutic filter cases. Complication rates were higher with prophylactic procedures than with therapeutic procedures and typically exceeded 2% in the prophylactic group. Each form of filter placement was associated with increases in all-cause hospitalization (regression coefficient 0.295 [95% CI 0.093–0.498], prophylactic; 0.673 [95% CI 0.547–0.798], therapeutic) and readmissions (OR 2.444 [95% CI 1.298–4.602], prophylactic; 2.074 [95% CI 1.644–2.616], therapeutic). IVC filter placement in this managed care population was associated with increased use of anticoagulants and greater healthcare utilization compared to controls, low rates of retrieval, and notable rates of device-related complications, with effects especially pronounced in assessments of prophylactic filters. These findings underscore the need for appropriate use of IVC filters.

Vena Cava Filter Use in Trauma and Rates of Pulmonary Embolism, 2003-2015

Vena cava filter (VCF) placement for pulmonary embolism (PE) prophylaxis in trauma is controversial. Limited research exists detailing trends in VCF use and occurrence of PE over time. To analyze state and nationwide temporal trends in VCF placement and PE occurrence from 2003 to 2015 using available data sets. A retrospective trauma cohort study was conducted using data from the Pennsylvania Trauma Outcome Study (PTOS) (461 974 patients from 2003 to 2015), the National Trauma Data Bank (NTDB) (5 755 095 patients from 2003 to 2014), and the National (Nationwide) Inpatient Sample (NIS) (24 449 476 patients from 2003 to 2013) databases. Temporal trends in VCF placement and PE rates, filter type (prophylactic or therapeutic), and established predictors of PE (obesity, pregnancy, cancer, deep vein thrombosis, major procedure, spinal cord paralysis, venous injury, lower extremity fracture, pelvic fracture, central line, intracranial hemorrhage, and blood transfusion). Prophylactic filters were defined as VCFs placed before or without an existing PE, while therapeutic filters were defined as VCFs placed after a PE. Of the 461 974 patients in PTOS, the mean (SD) age was 47.2 (26.4) and 61.6% (284 621) were men; of the 5 755 095 patients in NTDB, the mean age (SD) was 42.0 (24.3) and 63.7% (3 666 504) were men; and of the 24 449 476 patients in NIS, the mean (SD) age was 58.0 (25.2) and 49.7% (12 160 231) were men. Of patients receiving a filter (11 405 in the PTOS, 71 029 in the NTDB, and 189 957 in the NIS), most were prophylactic VCFs (93.6% in the PTOS, 93.5% in the NTDB, and 93.3% in the NIS). Unadjusted and adjusted temporal trends for the PTOS and NTDB showed initial increases in filter placement followed by significant declines (unadjusted reductions in VCF placement rates, 76.8% in the PTOS and 53.3% in the NTDB). The NIS demonstrated a similar unadjusted trend, with a slight increase and modest decline (22.2%) in VCF placement rates over time; however, adjusted trends showed a slight but significant increase in filter rates. Adjusted PE rates for the PTOS and NTDB showed significant initial increases followed by slight decreases, with limited variation during the declining filter use periods. The NIS showed an initial increase in PE rates followed by a period of stagnation. Despite a precipitous decline of VCF use in trauma, PE rates remained unchanged during this period. Taking this association into consideration, VCFs may have limited utility in influencing rates of PE. More judicious identification of at-risk patients is warranted to determine individuals who would most benefit from a VCF.

Association Between Inferior Vena Cava Filter Insertion in Trauma Patients and In-Hospital and Overall Mortality

There is no significant difference in survival in trauma patients with or without placement of an inferior vena cava (IVC) filter, whether in the presence or absence of venous thrombosis. The use of IVC filters in this population should be re-examined.

The Michigan Trauma Quality Improvement Program: Results from a collaborative quality initiative.

American College of Surgeons verified trauma centers and a third-party payer within the state of Michigan built a regional collaborative quality initiative (CQI). The Michigan Trauma Quality Improvement Program began as a pilot in 2008 and expanded to a formal program in 2011. Here, we examine the performance of the collaborative over time with regard to patient outcomes, resource utilization, and process measures. Data from the initial 23 hospitals that joined the CQI in 2011 were analyzed. Performance trends from 2011 to 2015 were evaluated for outcomes, resource utilization, and process measures using univariate analysis. Risk-adjustment was performed to confirm results observed in the unadjusted data. To calculate the potential number of patients impacted by the CQI program, the maximum absolute change was multiplied by the number of trauma patients treated in the 23 hospitals during 2015. Membership in a CQI program significantly reduced serious complications (8.5 vs. 7.3%, p = 0.002), decreased resource utilization, and improved process measure execution in trauma patients over 5 years time. Similar results were obtained in unadjusted and risk-adjusted analyses. The CQI program potentially avoided inferior vena cava filter placement in 167 patients annually. Decreased venous thromboembolism rates mirrored increased compliance with venous thromboembolism pharmacologic prophylaxis. This study confirms our hypothesis that participation in a regional CQI improves patient outcomes and decreases resource utilization while promoting compliance with processes of care. Economic/therapeutic care, level V.

Impact of Inferior Vena Cava Filter Placement on Short-Term Outcomes in Patients with Acute Pulmonary Embolism

Inferior vena cava filters (IVCFs) have been associated with improved survival in patients with acute pulmonary embolism (PE) in some studies. However, without randomization, those with early mortality who did not receive an IVCF might have died prior to treatment decision about filter placement, falsely contributing a survival advantage to those receiving IVCF and biasing the results of previous observational studies. The objective of this study is to evaluate the impact of IVCF on in-hospital mortality after adjusting for this survivor treatment selection. National Inpatient Sample data sets from 2009 to 2012 were analyzed to assess the impact of IVCF placement on in-hospital mortality in all patients with acute PE. Subgroup analyses were performed in those with high-risk PE (hemodynamic shock) and also for those with both shock and concomitant thrombolysis. Inverse propensity-score weighting was used to balance clinical and comorbid differences between filter and nonfilter groups. To account for survivor treatment selection bias, an extended Cox model was fitted with IVCF placement as a time-dependent covariate. We identified 263,955 patients with acute PE over this period; 36,702 (13.9%) received IVCF. Those receiving IVCF in the unadjusted cohort were older (IVCF: 66.3±15.9 vs. non-IVCF: 62.4±17.4; P<0.001) with higher rates of shock (6.8% vs. 3.8%; P<0.001), deep venous thrombosis (32.8% vs. 13.9%; P<0.001), thrombolytic therapy (5.9% vs. 1.6%; P<0.001), and lower crude mortality (6.0% vs. 6.7%; P<0.001). Propensity weighted extended Cox analysis showed that IVCF placement did not significantly decrease mortality hazard compared to an untreated patient (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.89-1.01). Similar results were seen in the combined high-risk and thrombolysis (HR: 0.85, 95% CI: 0.60-1.21) subgroup and associated with worse outcomes in the high-risk (HR: 1.2, 95% CI 1.11-1.38) subgroup. Placement of IVCF in all patients with acute PE, in high-risk patients, or in high-risk patients concurrently treated with thrombolysis is not significantly associated with improvement of in-hospital mortality when accounting for survivor treatment selection bias.