Perforation of the IVC: Rule Rather Than Exception After Longer Indwelling Times for the Günther Tulip and Celect Retrievable Filters

Right Ventricular Perforation and Subsequent Cardiac Tamponade Caused by IVC Filter Strut Fracture Migration

Cardiac tamponade, if not recognized and treated immediately, is a life threatening condition with various etiologies. Most common causes of cardiac tamponade encountered in emergency rooms are due to trauma, post myocardial infarction wall rupture, cancer and all other causes of pericardial effusion. Iatrogenic causes of cardiac tamponade include anticoagulation and procedures related. Currently there is a general comfort level amongst physicians that inferior vena cava (IVC) filters are not associated with significant complications. However, one of the feared life-threatening immediate complications of IVC filter placement is complete migration of the filter to the heart, with possible risk for cardiac arrhythmia, cardiac tamponade, and death. IVC filter strut fracture and migration to the heart and pulmonary arteries is another possible cause of cardiac tamponade and needs to be added to the differential diagnosis in the setting of tamponade signs and symptoms in a patient with history of IVC filter placement. We present a case of IVC filter strut fracture and migration to the right ventricle with penetration of the free wall causing cardiac tamponade with subsequent successful percutaneous retrieval. We hope to raise awareness through this case of the rare but potentially fatal complications of IVC filter placement and to advise regarding the judicious use of IVC filters.

A Novel Source of Chest Pain in the Emergency Department

This is a case report of a patient with an unusual presentation of an inferior vena cava (IVC) filter migration with a delayed presentation, and without electrical or valvular abnormalities. We discuss considerations and potential complications from IVC filter placement from the emergency physician perspective.

Omental flap transposition for inferior vena cava filter penetration

A 40-year-old woman presented with uterine malignancy, deep vein thrombosis, and nonmassive pulmonary embolism in both lungs. Gunter-tulip filter was inserted, because she had severe genital bleeding, which is one of the contraindications to anticoagulation therapy. Total hysterectomy was conducted and anticoagulation therapy was started afterward. The thrombus worsened perioperatively, and the filter could not be retrieved. Since there was lymph node recurrence, the second time operation was performed. During operation, the struts were found to be penetrating the inferior vena cava. Omental flap was used to cover the struts, and no associated complications occurred after operation.

Can Pre-Retrieval Computed Tomography Predict the Difficult Removal of an Implementing an Inferior Vena Cava Filter?

Purpose:

Implementing an inferior vena cava (IVC) filter is a relatively safe procedure but potential negative long-term effects. The complications for filter retrieval have been noted. We examined filter characteristics on pre-retrieval computed tomography (CT) that were associated with complicated retrieval (CR) of IVC filters.

Materials and Methods:

A retrospective review of IVC filter retrievals between January 2008 and June 2014 was performed to identify patients who had undergone a pre-retrieval CT for IVC filter retrieval. CR was defined as the use of nonstandard techniques, procedural time over 30 min, filter fractures, filter tip incorporation into the IVC wall, and retrieval failure. Pre-retrieval CT images were evaluated for tilt angle in the mediolateral and anteroposterior directions, tip embedding into the IVC wall, degree of filter strut perforation, and distance of the filter tip from the nearest renal vein.

Results:

Of seventy-six patients, twenty-four patients (31.6%) with CRs and 56 patients (73.7%) with non-CR were evaluated for pre-retrieval CT. For IVC filter retrieval with a dwelling time of over 45 days, a tilt of over 15 degrees, the appearance of tip embedding and grade 2 perforation were associated with CR on multivariate analysis. However, for IVC filter retrievals with a dwelling time of less than 45 days, there were no factors associated with CR.

Conclusion:

Pre-retrieval CTs may be more effective for IVC filters with a dwelling time of over 45 days. Therefore, a pre-retrieval CT may be helpful in predicting CR of IVC filters with long dwelling times.

Bundling of Reimbursement for Inferior Vena Cava Filter Placement Resulted in Significantly Decreased Utilization between 2012 and 2014

BACKGROUND

On January 1, 2012, reimbursement for inferior vena cava filters (IVCFs) became bundled by the Centers for Medicare and Medicaid Services. This resulted in ICVF placement (CPT code 37191) now yielding 4.71 relative value units (RVUs), a decrease from 15.6 RVUs for placement and associated procedures (CPT codes 37620, 36010, 75825-26, 75940-26). Our hypothesis was that IVCF utilization would decrease in response to this change as other procedures had done once they had become bundled.

METHODS

Including data from 2010 to 2011 (before bundling) and 2012 to 2014 (after bundling), we utilized 5% inpatient, outpatient, and carrier files of Medicare limited data sets and analyzed IVCF utilization before and after bundling across specialty types, controlling for total diagnosis of deep vein thrombosis (DVT) and pulmonary embolism (PE) (ICD-9 codes 453.xx and 415.xx, respectively) and placement location.

RESULTS

In 2010 and 2011, the rates/10,000 DVT/PE diagnoses were 918 and 1,052, respectively (average 985). In 2012, 2013, and 2014, rates were 987, 877, and 605, respectively (average 823). Comparing each year individually, there is a significant difference (P < 0.0001) with 2012, 2013, and 2014 having lower rates of ICVF utilization. Comparing averages in the 2010-2011 and 2012-2014 groups, there is also a significant decrease in utilization after bundling (P < 0.0001).

CONCLUSIONS

Following the bundling of reimbursement for IVCF placement, procedural utilization decreased significantly. More data from subsequent years will be needed to show if this decrease utilization continues to persist.

Retrievable IVC filters - Friend or foe

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

Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters

Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

A Dedicated Inferior Vena Cava Filter Service Line: How to Optimize Your Practice

Despite the increased placement of retrievable inferior vena cava filters (rIVCFs), efforts to remove these devices are not commensurate. The majority of rIVCFs are left in place beyond their indicated usage, and often are retained permanently. With a growing understanding of the clinical issues associated with these devices, the United States Food and Drug Administration (FDA) has prompted clinicians to remove rIVCF when they are no longer indicated. However, major obstacles exist to filter retrieval, chief among them being poor clinical follow-up. The establishment of a dedicated IVC filter service line, or clinic, has been shown to improve filter retrieval rates. Usage of particular devices, specifically permanent versus retrievable filters, is enhanced by prospective physician consultation. In this article, the rationale behind a dedicated IVC filter service line is presented as well as described the structure and activities of the authors' IVC filter clinic; supporting data will also be provided when appropriate.

Evidence-Based Evaluation of Inferior Vena Cava Filter Complications Based on Filter Type

Many inferior vena cava (IVC) filter types, along with their specific risks and complications, are not recognized. The purpose of this study was to evaluate the various FDA-approved IVC filter types to determine device-specific risks, as a way to help identify patients who may benefit from ongoing follow-up versus prompt filter retrieval. An evidence-based electronic search (FDA Premarket Notification, MEDLINE, FDA MAUDE) was performed to identify all IVC filter types and device-specific complications from 1980 to 2014. Twenty-three IVC filter types (14 retrievable, 9 permanent) were identified. The devices were categorized as follows: conical (n = 14), conical with umbrella (n = 1), conical with cylindrical element (n = 2), biconical with cylindrical element (n = 2), helical (n = 1), spiral (n = 1), and complex (n = 1). Purely conical filters were associated with the highest reported risks of penetration (90-100%). Filters with cylindrical or umbrella elements were associated with the highest reported risk of IVC thrombosis (30-50%). Conical Bard filters were associated with the highest reported risks of fracture (40%). The various FDA-approved IVC filter types were evaluated for device-specific complications based on best current evidence. This information can be used to guide and optimize clinical management in patients with indwelling IVC filters.

IVC filter retrieval in adolescents: experience in a tertiary pediatric center

BACKGROUND

Inferior vena cava (IVC) filters are commonly implanted with the intent to prevent life-threatening pulmonary embolism in at-risk patients with contraindications to anticoagulation. Various studies have reported increases in the rate of venous thromboembolism within the pediatric population. The utility and safety of IVC filters in children has not yet been fully defined.

OBJECTIVE

To describe the technique and adjunctive maneuvers of IVC filter removal in children, demonstrate its technical success and identify complications.

MATERIALS AND METHODS

A retrospective 10-year review was performed of 20 children (13 male, 7 female), mean age: 15.1 years (range: 12-19 years), who underwent IVC filter retrieval. Eleven of 20 (55%) were placed in our institution. Electronic medical records were reviewed for filter characteristics, retrieval technique, technical success and complications.

RESULTS

The technical success rate was 100%. Placement indications included: deep venous thrombosis with a contraindication to anticoagulation (10/20, 50%), free-floating thrombus (4/20, 20%), post-trauma pulmonary embolism prophylaxis (3/20, 15%) and pre-thrombolysis pulmonary patient (1/20, 5%). The mean implantation period was 63 days (range: 20-270 days). Standard retrieval was performed in 17/20 patients (85%). Adjunctive techniques were performed in 3/20 patients (15%) and included the double-snare technique, balloon assistance and endobronchial forceps retrieval. Median procedure time was 60 min (range: 45-240 min). Pre-retrieval cavogram demonstrated filter tilt in 5/20 patients (25%) with a mean angle of 17° (range: 8-40). Pre-retrieval CT demonstrated strut wall penetration and tip embedment in one patient each. There were two procedure-related complications: IVC mural dissection noted on venography in one patient and snare catheter fracture requiring retrieval in one patient. There were no early or late complications.

CONCLUSION

In children, IVC filter retrieval can be performed safely but may be challenging, especially in cases of filter tilt or embedding. Adjunctive techniques may increase filter retrieval rates.

Temporary Inferior Vena Cava Filters: How Do We Move Forward?

Despite their widespread use, the indications for the selective use of temporary inferior vena cava (IVC) filters remains uncertain with few trials supporting their use. Additionally, the risks of long-term temporary IVC filter insertion are being increasingly discussed amongst the mainstream media and through multiple class action lawsuits. Retrievable IVC filters were specifically designed to have a less secure implantation in order to facilitate retrieval. However, multiple reports have demonstrated significant filter-related complications, most commonly related to duration of implantation. Furthermore, the risk is not isolated to one manufacturer alone. The incidence of filter-related complications is linearly related to its duration of time on the market. Currently, the FDA recommends that IVC filters be removed within 25-54 days of their implantation. Unfortunately, little evidence exists to show that this recommendation is followed routinely. Recently, the PRESERVE Trial (NCT02381509) was initiated as a multicenter non-randomized open label study to determine the safety and effectiveness of commercially available IVC filters (both temporary and permanent) in individuals who require mechanical prophylaxis against pulmonary embolism. Until such evidence is developed, temporary IVC filters should be implanted based on best available evidence and routinely removed within the guidelines of the FDA of 25-54 days. A fair question at this point is whether the design features themselves that are required to manufacture a low profile removable IVC filter can achieve effective prophylaxis against pulmonary embolism at a low rate of short and long-term complications.

Caval Penetration by Inferior Vena Cava Filters

Background—

Limited penetration into the caval wall is an important securing mechanism for inferior vena cava (IVC) filters; however, caval penetration can also cause unintentional complications. The aim of this study was to assess the incidence, severity, clinical consequences, and management of filter penetration across a range of commercially available IVC filters.

Methods and Results—

The MEDLINE database was searched for all studies (1970–2014) related to IVC filters. A total of 88 clinical studies and 112 case reports qualified for analysis; these studies included 9002 patients and 15 types of IVC filters. Overall, penetration was reported in 19% of patients (1699 of 9002), and 19% of those penetrations (322 of 1699) showed evidence of organ/structure involvement. Among patients with penetration, 8% were symptomatic, 45% were asymptomatic, and 47% had unknown symptomatology. The most frequently reported symptom was pain (77%, 108 of 140). Major complications were reported in 83 patients (5%). These complications required interventions including surgical removal of the IVC filter (n=63), endovascular stent placement or embolization (n=11), endovascular retrieval of the permanent filter (n=4), and percutaneous nephrostomy or ureteral stent placement (n=3). Complications led to death in 2 patients. A total of 87% of patients (127 of 146) underwent premature filter retrieval or interventions for underlying symptoms or penetration-related complications.

Conclusions—

Caval penetration is a frequent but clinically underrecognized complication of IVC filter placement. Symptomatic patients accounted for nearly 1/10th of all penetrations; most of these cases had organ/structure involvement. Interventions with endovascular retrieval and surgery were required in most of these symptomatic patients.

Total laparoscopic retrieval of inferior vena cava filter

While there is some local variability in the use of inferior vena cava filters and there has been some evolution in the indications for filter placement over time, inferior vena cava filters remain a standard option for pulmonary embolism prophylaxis. Indications are clear in certain subpopulations of patients, particularly those with deep venous thrombosis and absolute contraindications to anticoagulation. There are, however, a variety of reported inferior vena cava filter complications in the short and long term, making retrieval of the filter desirable in most cases. Here, we present the case of a morbidly obese patient complaining of chronic abdominal pain after inferior vena cava filter placement and malposition of the filter with extensive protrusion outside the inferior vena cava. She underwent successful laparoscopic retrieval of her malpositioned inferior vena cava filters after failure of a conventional endovascular approach.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vertebral Body Erosion and Subsequent Back Pain Secondary to a Vena Cava Filter

Background: A patient with multiple open lumbar procedures, the most recent of which was complicated by symptomatic pulmonary embolus, underwent placement of an inferior vena cava filter (IVCF). Two years after placement, she developed low back pain with radicular symptoms. CT of the lumbar spine demonstrated vertebral body erosion from the IVCF strut. In this brief report, we describe L2 vertebral body erosion, radiographic findings, and a brief review of the literature.

Objective: To describe radiographic findings of vertebral body erosion from IVCF as well as review the literature regarding this and other complications of IVCF placement.

Methods: Retrospective, single patient chart review.

Results: The patient's IVCF was successfully removed without complication. The pain and radicular symptoms resolved by one month follow-up.

Conclusions: Based on the literature, most IVCFs with evidence of bony erosion are removed except when patient comorbidities, goals of care, or a complete absence of symptoms make removal inadvisable.

Pilot in vivo study of an absorbable polydioxanone vena cava filter

OBJECTIVE

The objectives of this study were to evaluate tensile strength retention of polydioxanone as a function of time in a swine venous system and to assess the feasibility of an absorbable inferior vena cava (IVC) filter made from polydioxanone in a pilot swine study.

METHODS

Twenty strands (60 cm each) of size 1 polydioxanone absorbable suture (Ethicon, Somerville, NJ) were placed in the central venous system of domestic swine. Strands were harvested at weekly intervals during 10 weeks for tensile strength testing. Results were compared with control samples obtained from an in vitro engineered circulation system containing sodium phosphate buffer solution. Three IVC filters braided from polydioxanone suture were also catheter deployed in three swine to assess absorbable IVC filter feasibility.

RESULTS

Polydioxanone retained 82% tensile strength in vitro vs 79% in vivo at 35 days (P > .22), the desired prophylactic duration. For IVC filters made from polydioxanone, technical success of placement was achieved in all three filters deployed (100%). Autologous thrombus deployed inferior to the filter remained trapped in the filter until thrombus resorption, with no evidence of pulmonary emboli on follow-up computed tomography. There were no instances of caval penetration, filter-induced IVC thrombosis, filter migration, or tilt >15 degrees with imaging and clinical follow-up carried out to 32 weeks.

CONCLUSIONS

Strength retention of polydioxanone suture placed in the venous system of swine is similar to earlier in vitro studies out to 10 weeks (P > .06 for all weeks) and is more than sufficient (8.20 ± 0.37 kg mean load at break for size 1) to trap thrombus. Pilot animal study suggests that an absorbable polydioxanone IVC filter can be catheter deployed to capture and to hold iatrogenically administered autologous thrombus through resorption.

IVC filter perforation through the duodenum found after years of abdominal pain

Patient: Female, 67

Final Diagnosis: IVC filter perforation through duodenum

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: Esophagogastroduodenoscopy

Specialty: Gastroenterology and Hepatology

The CIRSE Retrievable IVC Filter Registry: Retrieval Success Rates in Practice

CIRSE established a registry of retrievable filter use with the primary aim of determining the success of IVC Filter retrieval and associated complications. Secondary endpoints included filter indications, imaging strategies before retrieval, filter dwell times, and anticoagulation status. A web-based electronic registry was hosted between 01/12/2010 and 30/06/2012. Data entry occurred at the date of IVC filter retrieval and included items such as filter type, indication for filter insertion, access route, dwell time, retrieval success, complications, reasons for failed retrieval, and anticoagulation status. 671 filter retrievals were entered (male:female 333:295, mean age 55, median 57). Retrieval data were not entered in 43/671 leaving 628 patients for analysis. The 4 commonest retrievable filters used were the Celect in 182 patients, the OPTEASE in 161, ALN in 120, and Gunther Tulip in 98. Filters were inserted for absolute indications 40%, relative indications in 31%, and prophylactic in 24%, with 5% missing. Mean filter dwell time was 90 days. Filters were successfully retrieved in 576/628 patients (92%). The mean dwell time for successful retrievals was 85 days versus 145 days for unsuccessful retrievals (p = 0.001). Major complications occurred in 2 patients (0.03%). In summary, the CIRSE retrievable filter registry demonstrates a retrieval rate of 92% across a range of filter types, with a low major complication rate, reflecting current practice. There is an increase in trend of retrievable filter use for relative and prophylactic indications.

Respiratory-Induced Haemodynamic Changes: A Contributing Factor to IVC Filter Penetration

PURPOSE

The purpose of the study is to evaluate the influence of respiratory-induced vena caval hemodynamic changes on filter migration/penetration.

MATERIALS AND METHODS

After placement of either a Gunther Tulip or Celect IVC filter, 101 consecutive patients scheduled for filter retrieval were prospectively enrolled in this study. Pre-retrieval CT scans were used to assess filter complications and to calculate cross-sectional area in three locations: at level of filter strut fixation, 3 cm above and 3 cm below. A 3D finite element simulation was constructed on these data and direct IVC pressure was recorded during filter retrieval. Cross-sectional areas and pressures of the vena cava were measured during neutral breathing and in Valsalva maneuver and identified filter complications were recorded. A statistical analysis of these variables was then performed.

RESULTS

During Valsalva maneuvers, a 60 % decrease of the IVC cross-sectional area and a fivefold increase in the IVC pressure were identified (p < 0.001). There was a statistically significant difference in the reduction of the cross-sectional area at the filter strut level (p < 0.001) in patient with filter penetration. Difficulty in filter retrieval was higher in penetrated or tilted filters (p < 0.001; p = 0.005). 3D computational models showed significant IVC deformation around the filter during Valsalva maneuver.

CONCLUSION

Caval morphology and hemodynamics are clearly affected by Valsalva maneuvers. A physiological reduction of IVC cross-sectional area is associated with higher risk of filter penetration, despite short dwell times. Physiologic data should be used to improve future filter designs to remain safely implanted over longer dwell times.

Procedural and indwelling complications with inferior vena cava filters: frequency, etiology, and management

Inferior vena cava (IVC) filters are commonly used in select high-risk patients for the prevention of pulmonary embolism. Potentially serious complications can arise from the use of IVC filters, including thrombosis of the filter itself and filter fragment embolization. This article discusses the utility of IVC filters and reviews the management of two cases of filter-related complications.

Midterm follow-up after retrievable inferior vena cava filter placement in venous thromboembolism patients with or without malignancy

BACKGROUND

A clear indication and strategy for placement of retrievable inferior vena cava filters (IVCFs) have not been established. This study was designed to evaluate the efficacy and disadvantages of the retrievable IVCF use particularly in venous thromboembolism (VTE) patients with malignancy.

HYPOTHESIS

Retrievable IVCFs might be safe and useful in VTE patients with malignancy.

METHODS

The study population consisted of 56 consecutive patients undergoing IVCF placement at our institution from January 1, 2008 to December 31, 2011. Prognostic data were retrospectively reviewed in April 2013.

RESULTS

Mean follow-up period was 584.6 (range, 1-1857) days. Twenty-six of the 56 patients had a malignancy. In 16 of the 30 patients without malignancy, the filter was retrieved, whereas the other 14 patients eventually received permanent implantation. There was no significant difference in the survival rate between the retrieval group and the nonretrieval group in the nonmalignancy patients (1-year survival rates, 94% vs 85%). In patients with malignancy, the nonretrieval group showed a significantly lower survival rate (P < 0.01). The 1-year and 2-year survival rates were 100% vs 46% and 100% vs 18%, respectively. There was no medical record of pulmonary thromboembolism occurrence or recurrence. All deaths in the patients with malignancy were malignancy related. In 4 of 5 malignancy patients who could undergo tumor resection surgery, adequate thrombus regression enabled us to retrieve the IVCF after surgery.

CONCLUSIONS

Permanent use of a retrievable IVCF is relatively safe in short- or midterm follow-up regardless of malignancy status. Retrievable filter use might be reasonable in malignancy patients.

Improving inferior vena cava filter retrieval rates with the define, measure, analyze, improve, control methodology

PURPOSE

To design a sustainable process to improve optional inferior vena cava (IVC) filter retrieval rates based on the Define, Measure, Analyze, Improve, Control (DMAIC) methodology of the Six Sigma process improvement paradigm.

MATERIALS AND METHODS

DMAIC, an acronym for Define, Measure, Analyze, Improve, and Control, was employed to design and implement a quality improvement project to increase IVC filter retrieval rates at a tertiary academic hospital. Retrievable IVC filters were placed in 139 patients over a 2-year period. The baseline IVC filter retrieval rate (n = 51) was reviewed through a retrospective analysis, and two strategies were devised to improve the filter retrieval rate: (a) mailing of letters to clinicians and patients for patients who had filters placed within 8 months of implementation of the project (n = 43) and (b) a prospective automated scheduling of a clinic visit at 4 weeks after filter placement for all new patients (n = 45). The effectiveness of these strategies was assessed by measuring the filter retrieval rates and estimated increase in revenue to interventional radiology.

RESULTS

IVC filter retrieval rates increased from a baseline of 8% to 40% with the mailing of letters and to 52% with the automated scheduling of a clinic visit 4 weeks after IVC filter placement. The estimated revenue per 100 IVC filters placed increased from $2,249 to $10,518 with the mailing of letters and to $17,022 with the automated scheduling of a clinic visit.

CONCLUSIONS

Using the DMAIC methodology, a simple and sustainable quality improvement intervention was devised that markedly improved IVC filter retrieval rates in eligible patients.

Venous thromboembolism in cancer patients

OBJECTIVE

Venous thromboembolism (VTE) is a common complication in cancer patients. This review summarizes some of the most current knowledge of the epidemiology, risk factors, risk models, prophylaxis, and treatment of VTE in cancer patients.

METHODS

A literature search was conducted using PubMed; the search terms were venous thromboembolism, anticoagulation, and cancer. The bibliographies of pertinent studies and review articles were reviewed for additional references.

RESULTS

Venous thromboembolism is the second leading cause of death in patients with cancer. Cancer patients with VTE have poorer outcomes compared with noncancer patients with VTE. Many risk factors have been identified for VTE in patients with cancer that are patient-related, cancer-related, or treatment-related. Several biomarkers have been identified as potentially predictive of VTE risk. Risk assessment models such as the Khorana Risk Score stratify cancer patients with low, intermediate, and high risk of developing VTE based on baseline clinical and laboratory variables. Currently, enoxaparin is the preferred anticoagulant for initial VTE treatment in cancer patients. Low molecular weight heparin (LMWH) is recommended for both initial and long-term management of cancer-related VTE. Because the optimal duration of anticoagulation in cancer patients with VTE is unknown, the decision to extend anticoagulation requires weighing the risk of recurrent thrombosis against the risk of major bleeding. Patients with recurrent VTE can be bridged with LMWH, transitioned to full-dose LMWH or treated with LMWH dose escalation. While there is insufficient data to determine whether anticoagulation should be held in the setting of thrombocytopenia, full-dose anticoagulation is typically considered unsafe when platelets are < 50 000/μL. Inferior vena cava filters are currently recommended only for patients with acute VTE and contraindications to anticoagulation. Although management of catheter-associated thrombosis has not been well studied in cancer patients, it is recommended that cancer patients with catheter-associated thrombosis be treated with therapeutic anticoagulation for ≥ 3 months. Venous thromboembolism prophylaxis with UFH, LMWH, or fondaparinux is recommended in all hospitalized nonsurgical cancer patients and cancer patients undergoing major cancer surgery. Primary thromboprophylaxis is only currently recommended in high-risk ambulatory cancer patients such as multiple myeloma patients receiving thalidomide- or lenalidomide- based therapy.

CONCLUSION

Cancer-associated thrombosis is a common problem. As we begin to better understand the risk factors and biomarkers for cancer-associated VTE, we can further refine and develop risk-assessment models to determine those patients who would most likely benefit from anticoagulation. While LMWH products are generally preferred in cancer-related VTE, more research will continue to evolve our understanding of treatment and thrombopprophylaxis in cancer-associated VTE.

Strut penetration: local complications, breakthrough pulmonary embolism, and retrieval failure in patients with Celect vena cava filters

PURPOSE

To investigate strut penetration in patients with Celect filters, specifically local complications and association with breakthrough pulmonary embolism (PE) or retrieval failure.

MATERIALS AND METHODS

A retrospective single-center study was conducted to evaluate patients who received Celect filters between January 2007 and May 2013. A total of 595 filters were placed during the study period. Primary indications included thromboembolic disease (93%) and primary surgical prophylaxis (7%). Complications and retrieval data were assessed by computed tomography (CT) and electronic medical records.

RESULTS

A total of 193 patients underwent follow-up abdominal CT at a mean follow-up interval of 176.2 days (range, 0-1,739 d). The rate of strut penetration more than 3 mm outside the caval wall was 28.5% (n = 55). One patient had CT evidence of clinically major strut penetration (1.8%) with strut compression of the right ureter causing hydronephrosis. Indwelling filter time longer than 100 days was associated with strut penetration (P < .001). Age, sex, and history of thromboembolic disease were not associated with strut penetration (P = .51, P = .81, and P = .89). Sixty-three patients presented for follow-up CT pulmonary angiography at a mean of 128.1 days (range, 1-895 d). The rate of breakthrough PE was 12.7%. The overall retrieval success rate was 96.7% (n = 150). Strut penetration was not associated with breakthrough PE or retrieval failure (P = .49 and P = .22).

CONCLUSIONS

Although strut penetration is a common complication with Celect filters, there is no association with breakthrough PE or retrieval failure. CT evidence of local complications associated with strut penetration is rare.

Failed inferior vena cava filter retrieval by conventional method: Analysis of its causes and retrieval of it by modified double-loop technique

OBJECTIVES

To evaluate the complications of the temporary implanted inferior vena cava (IVC) filter and the feasibility of double-loop technique for removal of complicated IVC filters.

METHODS

From January 2012 to December 2013, a total of 25 patients with IVC filter were referred for IVC filter retrieval. There were 20 Celect®, 3 OptEase®, and 2 Günther-Tulip® filters. All of the patients were evaluated with a pre-procedural CT scan to identify any complications. The IVC filters which had failed to be retrieved by the conventional method were evaluated, and retrieval was attempted with double loop technique.

RESULTS

Sixteen of 25 (64%) filters had complications; IVC wall penetration (n = 11, 44%), tilted within IVC (n = 6, 24%), embedded struts (n = 3, 12%), and fracture of the strut (n = 1, 4%). The complications were overlapped in five patients. Two of them (8%) had also complained of filter-related pain. The success rate of IVC filter retrieval by double-loop technique was 14/16 (87.5%). There was no major filter retrieval-related complications.

CONCLUSIONS

The double-loop technique is a safe and feasible method for complicated IVC filter retrieval.

Comparison of complication rates associated with permanent and retrievable inferior vena cava filters: a review of the MAUDE database

PURPOSE

To compare the safety of permanent and retrievable inferior vena cava (IVC) filters by reviewing the U.S. Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database.

MATERIALS AND METHODS

The MAUDE database was reviewed from January 1, 2009, to December 31, 2012. Product class search criteria were "filter, intravascular, cardiovascular." Type of device used and specific adverse events (AEs) were recorded.

RESULTS

For the period January 2009-December 2012, 1,606 reported AEs involving 1,057 IVC filters were identified in the MAUDE database . Of reported AEs, 1,394 (86.8%) involved retrievable inferior vena cava filters (rIVCFs), and 212 (13.2%) involved permanent inferior vena cava filters (pIVCFs) (P < .0001). Reported AEs included fracture, migration, limb embolization, tilt, IVC penetration, venous thromboembolism and pulmonary embolism, IVC thrombus, and malfunctions during placement. Each specific AE was reported with significantly higher frequency in rIVCFs compared with pIVCFs. The most common reported complication with rIVCFs was fracture, whereas the most commonly reported complications with pIVCFs were placement malfunctions. For rIVCFs, the most commonly reported AE varied depending on filter brand.

CONCLUSIONS

The MAUDE database reveals that complications occur with significantly higher frequency with rIVCFs compared with pIVCFs. This finding suggests that the self-reported complication rate with rIVCFs is significantly higher than the self-reported complication rate with pIVCFs.

Clinical outcomes and causes of death in Japanese patients with long-term inferior vena cava filter implants and deep vein thrombosis

BACKGROUND AND PURPOSE

We assessed the causes of death and efficacy of permanent inferior vena cava (IVC) filters for preventing new pulmonary embolisms (PE) in Japanese deep vein thrombosis (DVT) patients with or without PE.

METHODS AND SUBJECTS

We studied the clinical outcomes during the follow-up period of 1 day to 9 years (median: 18 months; mean: 28 months) in 66 of 72 consecutive patients (44 with acute PE, 27 with intrapelvic DVT, and 1 with floating femoral vein thrombosis). Fifty of 66 patients received anticoagulant therapy after the filter placement.

RESULTS

Five patients died within 1 month (median 9 days) after the filter placement: three from recurrence of PE, one from cancer, and one from sepsis. Two of the three patients with recurrence of PE had preexisting intracardiac thrombi in the right atrium or main pulmonary artery before filter implantation. Ten patients died from the underlying disease (cancer: 7; brain hemorrhage: 1; amyotrophic lateral sclerosis: 1; pneumonia: 1) over 1 month after the filter placement (median follow-up period: 21 months). No new symptomatic PE recurrence was observed over 1 month after the filter placement. The 61 patients with long-term follow-up had no deterioration of DVT, and all the 31 patients who underwent multi-slice computed tomography showed no PE recurrence or filter thrombus occlusion, fracture, or migration.

CONCLUSIONS

Underlying diseases and preexisting intracardiac thrombi may be the determining factors for the prognosis of DVT patients. Permanent IVC filters with anticoagulant therapy may be effective for preventing death from new PE in Japanese DVT patients.

Penetration of the inferior vena cava and adjacent organs after filter placement is associated with retrievable filter type and length of time in place

OBJECTIVE

Concern over local complications of inferior vena cava (IVC) filters exists, but little long-term data are available. Referrals for filter penetrations on computed tomography (CT) have increased with no standards for management. We reviewed postfilter CT findings in our institution.

METHODS

All patients receiving IVC filters between January 1, 2006 and December 31, 2009 with a postfilter CT were reviewed. Penetration was graded with a previously published scale. Filter indication, type, and subsequent encounters for abdominal or back pain were recorded.

RESULTS

A total of 591 patients had a filter during the study period. Of these, 262 had an adequate postfilter CT, comprising the study group. Indications were prophylaxis in 16.4% and venous thromboembolism in 83.6%. Of filters placed for venous thromboembolism, indications were absolute (inability/failure of anticoagulation) in 44.7% and relative in 55.3%. Retrievable filters made up 92.7% of the filters, and 7.3% were permanent type. Of the retrievable filters, 1.6% were retrieved. One hundred twenty (45.8%) filters had grade 2 or 3 penetration. Another 38.2% (100) had struts immediately adjacent to the external aspect of the IVC, which may represent tenting of the cava. Grade 2 or 3 penetration occurred in 49.0% of retrievable filters but only 5.3% of permanent filters (P = .0001). Grade 2 or 3 penetration occurred in 18.2% of filters less than 30 days old but in 57.3% of filters 30 days old or older (P < .0001). Thirty-two patients had subsequent encounters for abdominal or back pain, but none was conclusively related to penetration.

CONCLUSIONS

A majority of filters were placed for prophylaxis or relative indications and were retrievable type. Retrieval rate was low. Penetration of the IVC and adjacent organs was common and associated with retrievable type and length of time in place. It is unclear if most penetrations cause problems. Monitoring of penetrations with CT may be important to understand the natural history of this condition.

Clinical course and predictive factors for complication of inferior vena cava filters

RATIONALE

The use of inferior vena cava (IVC) filters is associated with various complications. We aimed to elucidate the clinical course and predictive factors for complications of IVC filters, especially IVC penetration

METHODS

A retrospective observational study was performed in 45 adult patients with retrievable IVC filters and follow-up computed tomography (CT) between January 2003 and December 2012. Primary outcomes were the prevalence and predictive factors of IVC penetration. Secondary outcome was other complications of IVC filters.

RESULTS

IVC penetration following filter placement occurred in 87.6% of patients, and 57.8% of those involved significant penetration. Embedding of filter tips, suggestive of lateral tilting, was observed in 51.1%. Both Vertebral body erosions and aortic penetrations were seen in 4.4%, but they were asymptomatic. Longer indwelling duration of the IVC filter was significantly associated with a higher grade of IVC penetration, and the risk of significant IVC penetration increased in patients with the filter indwelling time of more than 20 days and an IVC diameter of less than 24.2mm.

CONCLUSIONS

In patients with a retrievable IVC filter, IVC penetration on CT was common, and significant IVC penetration was associated with a longer indwelling time of the IVC filter and a lesser IVC diameter.

Factors affecting Cook Gunther Tulip and Cook Celect inferior vena cava filter retrieval success

OBJECTIVE

Success rates vary for the retrieval of inferior vena cava filters (IVCFs). The optimal retrieval time and factors influencing retrieval success remain unproven. This study aims to determine optimal time and evaluate factors related to successful IVCF retrieval.

METHODS

An institutional prospectively maintained database was reviewed for all IVCF retrieval attempts from 2006 to 2012. Patient demographics, comorbidities, indications for procedure, placement technique, IVCF type, presence of angulation, and time to retrieval were evaluated with respect to success or failure of retrieval. Statistical analyses (t-test, χ(2), correlations, and Kaplan-Meier plots) were performed comparing successful and unsuccessful retrievals.

RESULTS

Of 121 attempted IVCF retrievals, 92 (76%) were successful and 29 (24%) were unsuccessful. There were no significant differences between the successful and unsuccessful attempts in terms of patient demographics, comorbidities, indications for procedure, placement technique, or IVCF type, which included 93 Celect (77%) and 28 Gunther Tulip (23%). Time since IVCF placement was significantly different (P = .025) between the successful and unsuccessful retrieval groups (medians were 105 [7-368] and 162 [43-379] days, respectively). Time since IVCF placement greater than 117 days correlated significantly with unsuccessful IVCF retrieval (R = 0.218; P = .017; odds ratio, 2.88; P = .02). Angulation greater than 20 degrees on anteroposterior radiograph was noted in seven of 29 (24%) unsuccessful retrievals compared with seven of 92 (8%) successful retrievals and was significant (P = .012).

CONCLUSIONS

Cook Gunther Tulip and Celect IVCF retrieval is most likely to be successful within 3 to 4 months of placement. Unsuccessful retrieval attempts are more likely to occur when IVCF position is angulated.

Clinical review: inferior vena cava filters in the age of patient-centered outcomes

Inferior vena cava filter (IVCF) use continues to increase in the United States (US) despite questionable clinical benefit and increasing concerns over long-term complications. For this review we comprehensively examine the randomized, prospective data on IVC filter efficacy, compare relative rates of IVCF placement in the US and Europe, compare commonly considered guidelines for IVCF indications, and the current data on IVCF complications. Searches of MEDLINE and Cochrane databases were conducted for randomized prospective IVCF studies. Only three randomized prospective studies for IVCFs were identified. Commonly cited IVCF guidelines were reviewed with attention to their evolution over time. No evidence has shown a survival benefit with IVCF use. Despite this, continued rising utilization, especially for primary prophylactic indications, is concerning, given increasing evidence of long-term filter-related complications. This is particularly noted in the US where IVCF placements for 2012 are projected to be 25 times that of an equivalent population in Europe (224,700 versus 9,070). Pending much-needed randomized controlled trials that also evaluate long-term safety, we support the more stringent American College of Chest Physicians (ACCP) guidelines for IVCF placement indications and advocate a close, structured follow-up of retrievable IVCFs to improve filter retrieval rates.