Guidelines for the Use of Retrievable and Convertible Vena Cava Filters: Report from the Society of Interventional Radiology Multidisciplinary Consensus Conference

Analysis of patent, unstented lower extremity vein segment diameters in 266 patients with venous disease

OBJECTIVE

The objective of this study was to characterize the average maximum diameters of widely patent lower extremity vein segments in patients with underlying venous disease and the demographic factors that affect these diameters.

METHODS

Maximum axial diameters of each deep vein segment from the diaphragm to the knee were measured from computed tomography venography studies for all patients who underwent venous stent placement during a 20-year period at a single quaternary venous referral institution. Limbs containing only widely patent, unstented vein segments without variant anatomy were identified for inclusion. The final analysis involved diameter measurements from 870 imaging studies of 266 patients. Multivariate linear regression was used to identify factors associated with vein segment diameters.

RESULTS

Average vein segment diameters ranged from 7.8 mm for the left and right femoral veins to 27.9 mm for the long axis of the suprarenal inferior vena cava. Multivariate linear regression demonstrated that women had larger IVC, common iliac vein, and external iliac vein diameters, whereas men had larger common femoral veins. Laterality, height, weight, and sex also had statistically significant associations with the diameters of select vein segments.

CONCLUSIONS

This study provides an estimate of the average diameters of widely patent deep vein segments in the lower extremities from the diaphragm to the knees in patients with underlying venous disease and characterizes covariates that significantly affect vein diameter. These findings may help interventionalists better select devices for endovascular intervention.

Inferior Vena Cava Filter Evaluation and Management for the Diagnostic Radiologist: A Comprehensive Review Including Inferior Vena Cava Filter-Related Complications and PRESERVE Trial Filters

Inferior vena cava filters are commonly encountered devices on diagnostic imaging that were highlighted in a 2010 Food and Drug Administration safety advisory regarding their complications from long-term implantation. The Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE) trial is an ongoing after-market study investigating the safety and utility of commonly utilized filters in practice today. While most of these filters are safe, prompt recognition and management of any filter-associated complication is imperative to prevent or reduce the morbidity and mortality associated with them. This review is aimed at discussing the appropriate utilization and placement of inferior vena cava filters in addition to the recognition of filter-associated complications on cross-sectional imaging. An overview of the PRESRVE trial filters is also provided to understand each filter's propensity for specific complications.

Magnification Spot Radiographs Improve Assessment for Inferior Vena Cava Filter Fractures prior to Removal Compared to CT

PURPOSE

To determine if magnification spot radiographs acquired before attempting inferior vena cava (IVC) filter removal have value in the assessment for filter fractures.

MATERIALS AND METHODS

A retrospective review of complex IVC filter removals performed at a tertiary referral center from October 2015 to May 2017 was performed. Magnification spot radiographs (frontal and at least 2 oblique views) were obtained with the fluoroscopic unit in the procedure suite prior to venous access for filter removal. Patients were included in the study if a computed tomography (CT) scan of the abdomen/pelvis before filter removal was available. Ninety-six patients (47 women and 49 men) were included. Most removed filters were the Recovery/G2/G2X/Eclipse/Meridian (n = 28), the Günther Tulip (n = 26), and the Celect/Celect Platinum (n = 22). Blinded review of the pre-procedural CT scans and spot radiographs for the presence of filter fractures was performed by 2 interventional radiologists. Accuracy of each modality was assessed using the status of the explanted filter as the gold standard. Agreement between the 2 readers was assessed with the kappa statistic.

RESULTS

Fractures were present in 27 explanted filters (28%). Accuracy of CT was 88% and 68% for readers 1 and 2, respectively, which increased to 98% and 97% with magnification spot radiographs. The kappa statistic was 0.12 for CT and 0.97 for spot radiographs.

CONCLUSIONS

Magnification spot radiographs acquired before attempting IVC filter removal improve detection of filter fractures and agreement among interventional radiologists. Therefore, these should be performed routinely to allow for optimal treatment planning.

A Single-Institutional Comparative Analysis of Advanced Versus Standard Snare Removal of Inferior Vena Cava Filters

PURPOSE

To investigate differences in procedure time, radiation exposure, and periprocedural complications associated with advanced inferior vena cava (IVC) filter retrieval compared with standard snare retrieval.

MATERIALS AND METHODS

A total of 378 patients underwent standard or advanced IVC filter retrieval over a 5-year period. Technical success, retrieval techniques, fluoroscopy time, radiation dose, and complications were analyzed. All retrieval procedures with techniques other than a "snare-and-sheath" method were categorized as advanced, including failed standard attempts requiring intraprocedural conversion to advanced techniques.

RESULTS

A total of 462 filter retrieval attempts were made in 378 patients (57% female). Success rates for standard and advanced retrieval attempts were 86.8% (317 of 365) and 91.8% (89 of 97), respectively. The rate of periprocedural complications was significantly higher in the advanced retrieval group (P = .006). Complication rates for standard and advanced retrievals were 0.6% (2 of 318; all minor) and 5.2% (5 of 97; 3 minor [3.1%] and 2 major [2.1%]), respectively. The 2 major complications during advanced retrievals included filter fracture and embolization. Average fluoroscopy time for advanced retrievals was significantly higher than for standard retrievals (23.1 min vs 4.3 min; P < .001). Average radiation dose for advanced retrievals was also significantly higher than for standard retrievals (557.2 mGy vs 156.9 mGy; P < .001). Use of general anesthesia was also significantly more common in advanced retrievals compared with standard retrievals (6.2% vs 0.9%; P = .002).

CONCLUSIONS

Advanced filter retrieval results in a similarly high rate of technical success compared with standard snare retrieval but is associated with greater fluoroscopy time, anesthesia requirements, and radiation exposure.

Transhepatic inferior vena cava filter retrieval due to chronic occlusion of jugular and subclavian veins

Retrieval of inferior vena cava filters is routinely performed via an internal jugular venous access. We present a case of a 55-year-old woman with myeloproliferative disorder, complicated by venous thrombosis. She was referred to interventional radiology for removal of an inferior vena cava filter, which had been placed 5 months prior for mechanical prophylaxis in the setting of femoral orthopedic surgery. Due to the patient's chronic occlusion of the bilateral jugular and subclavian veins, a transhepatic approach was used to retrieve the filter successfully without immediate complications.

Perforation of inferior vena cava and duodenum by strut of inferior vena cava filter: A case report

INTRODUCTION

An Inferior vena cava (IVC) filter is an intravascular filter that is implanted into the IVC to prevent pulmonary embolism in medical, surgical, and trauma patients. The insertion of an IVC filter is a relatively safe procedure, but rarely may be associated with symptomatic perforation of the IVC wall, particularly in the long term.

PATIENT CONCERNS AND DIAGNOSIS

A 74-year-old-woman with a medical history of IVC filter insertion visited the emergency department complaining of abdominal pain. A computed tomography scan showed perforation of the IVC wall and penetration into the duodenum by one of the filter's struts.

INTERVENTIONS

We performed a laparotomy to remove the IVC filter.

OUTCOMES

Postoperatively, the patient was admitted to the general ward. On hospital day 12, she was discharged without any complications. We followed her up and computed tomography did not show any abnormal findings six months after discharge.

LESSONS

There is currently no evidence testifying to the benefits of IVC filter removal. Detailed, evidence-based guidelines on the indications, timing and procedure for IVC filter removal are needed. Documenting cases of long-term complications of IVC filter s such as in this patient serve to accelerate the publication of updated guidelines and are aimed at improving outcomes of similar cases in the future.

Clinical outcomes of inferior vena cava filter in complicated pulmonary embolism

Background: Previous observational studies suggest that inferior vena cava filter placement in pulmonary embolism patients complicated with congestive heart failure, mechanical ventilation, and shock may have a mortality benefit. We sought to analyze the survival benefits of inferior vena cava filter in pulmonary embolism patients complicated with acute myocardial infarction, acute respiratory failure, shock, or requiring treatment with thrombolytics. Methods: This retrospective observational study used hospital discharge data from the National Inpatient Sample Data (NIS). ICD-9-CM coding was used to identify complicated pulmonary embolism patients (N = 254,465) in NIS from 2002 to 2014, including the subgroups of acute myocardial infarction, acute respiratory failure, shock, and thrombolytics. Inferior vena cava filter recipients were 1:1 propensity score-matched on age, sex, race, deep vein thrombosis, Elixhauser comorbidities, and other pulmonary embolism comorbidities (45 covariates) to non-inferior vena cava filter recipients in complicated pulmonary embolism patients and separately in each subgroup. Clinical outcomes were compared between the inferior vena cava filter group and the non-inferior vena cava filter group. Results: Mortality rate in complicated pulmonary embolism patients with inferior vena cava filter placement was lower (20.9% vs. 33%; NNT = 8.28, 95% confidence interval (CI) 7.91-8.69, E-value = 2.53) and in the subgroups; acute myocardial infarction (17.9% vs. 30.1%; NNT = 8.19, 95% CI 7.52-8.92, E-value = 2.76), acute respiratory failure (19.5% vs. 29.7%; NNT = 9.76, 95% CI 8.67-11.16, E-value = 2.38), shock (30.7% vs. 47.1%; NNT = 6.08, 95% CI 5.73-6.47, E-value = 2.43), and with the use of thrombolytics (7% vs. 12.9 %; NNT 17.1, 95% CI 14.88-20.12, E-value = 3.01) (p < 0.001 for all). Conclusion: Inferior vena cava filter placement in pulmonary embolism complicated with acute myocardial infarction, acute respiratory failure, shock, or requiring thrombolytic therapy was associated with reduced mortality.

Deep Learning for Automated Classification of Inferior Vena Cava Filter Types on Radiographs

PURPOSE

To demonstrate the feasibility and evaluate the performance of a deep-learning convolutional neural network (CNN) classification model for automated identification of different types of inferior vena cava (IVC) filters on radiographs.

MATERIALS AND METHODS

In total, 1,375 cropped radiographic images of 14 types of IVC filters were collected from patients enrolled in a single-center IVC filter registry, with 139 images withheld as a test set and the remainder used to train and validate the classification model. Image brightness, contrast, intensity, and rotation were varied to augment the training set. A 50-layer ResNet architecture with fixed pre-trained weights was trained using a soft margin loss over 50 epochs. The final model was evaluated on the test set.

RESULTS

The CNN classification model achieved a F1 score of 0.97 (0.92-0.99) for the test set overall and of 1.00 for 10 of 14 individual filter types. Of the 139 test set images, 4 (2.9%) were misidentified, all mistaken for other filter types that appear highly similar. Heat maps elucidated salient features for each filter type that the model used for class prediction.

CONCLUSIONS

A CNN classification model was successfully developed to identify 14 types of IVC filters on radiographs and demonstrated high performance. Further refinement and testing of the model is necessary before potential real-world application.

Inadvertent noncaval filter deployment and its management

Inferior vena cava filters are placed to prevent life-threatening pulmonary embolism in a selected group of patients. Significant complications are known to occur with prolonged dwell times, and rarely during initial placement. In this report, we describe two cases of inadvertent noncaval inferior vena cava filter placements, specifically in the azygous vein and right renal vein, and the complex methods used to retrieve them, which exemplify the critical importance of routine and careful placement techniques.

A Multicenter Trial of Vena Cava Filters in Severely Injured Patients

BACKGROUND

Whether early placement of an inferior vena cava filter reduces the risk of pulmonary embolism or death in severely injured patients who have a contraindication to prophylactic anticoagulation is not known.

METHODS

In this multicenter, randomized, controlled trial, we assigned 240 severely injured patients (Injury Severity Score >15 [scores range from 0 to 75, with higher scores indicating more severe injury]) who had a contraindication to anticoagulant agents to have a vena cava filter placed within the first 72 hours after admission for the injury or to have no filter placed. The primary end point was a composite of symptomatic pulmonary embolism or death from any cause at 90 days after enrollment; a secondary end point was symptomatic pulmonary embolism between day 8 and day 90 in the subgroup of patients who survived at least 7 days and did not receive prophylactic anticoagulation within 7 days after injury. All patients underwent ultrasonography of the legs at 2 weeks; patients also underwent mandatory computed tomographic pulmonary angiography when prespecified criteria were met.

RESULTS

The median age of the patients was 39 years, and the median Injury Severity Score was 27. Early placement of a vena cava filter did not result in a significantly lower incidence of symptomatic pulmonary embolism or death than no placement of a filter (13.9% in the vena cava filter group and 14.4% in the control group; hazard ratio, 0.99; 95% confidence interval [CI], 0.51 to 1.94; P = 0.98). Among the 46 patients in the vena cava filter group and the 34 patients in the control group who did not receive prophylactic anticoagulation within 7 days after injury, pulmonary embolism developed in none of those in the vena cava filter group and in 5 (14.7%) in the control group, including 1 patient who died (relative risk of pulmonary embolism, 0; 95% CI, 0.00 to 0.55). An entrapped thrombus was found in the filter in 6 patients.

CONCLUSIONS

Early prophylactic placement of a vena cava filter after major trauma did not result in a lower incidence of symptomatic pulmonary embolism or death at 90 days than no placement of a filter. (Funded by the Medical Research Foundation of Royal Perth Hospital and others; Australian New Zealand Clinical Trials Registry number, ACTRN12614000963628.).

Inferior Vena Cava Filters in Hemodynamically Unstable Patients with Acute Pulmonary Embolism: How Often are They Used? Data from Multicenter Prospective Registries on Acute Pulmonary Embolism

The use of inferior vena cava (IVC) filters is recommended in patients with acute pulmonary embolism (PE) who have absolute contraindications to anticoagulant drugs and/or in those subjects with recurrent PE despite treated with an adequate anticoagulant regimen. During the last 2 decades, some investigations have demonstrated that the use of IVC filters in high-risk PE patients, treated or not with systemic thrombolysis, was able to reduce the short-term mortality rate if inserted early after the acute event. The aim of the present review is to analyze the use of IVC filters in high-risk PE patients enrolled in prospective multicenter registries between 1990 and 2018. After screening 3542 article in PubMed, Scopus, Cochrane library and Goggle Scholar databases, we identified four registry studies meeting the inclusion criteria. In a prospective cohort of 39,056 patients, 1387 (3.5%) were hemodynamically unstable at admission. Among them, IVC filters were used only in 2.7% of cases. Conversely, IVC filters were inserted in 3.8% of hemodynamically stable patients. Over the years, a fluctuating trend in the use of IVC filters was observed. In the absence of randomized controlled trial on this issue, which would be difficult, if not impossible to realize, data obtained from the medical literature seem to suggest that IVC filters could represent a valid adjunctive therapy in hemodynamically unstable PE patients, able to prevent further hemodynamic deterioration. Further and larger subgroup analyses, obtained both by prospective and retrospective studies, are necessary to clarify this therapeutic approach.

Investigation of the Incidence of Perioperative Pulmonary Embolism in Patients with Below-Knee Deep Vein Thrombosis after Lower Extremity Fracture and Evaluation of Retrievable Inferior Vena Cava Filter Deployment in These Patients

BACKGROUND

The objectives of the study were to investigate and compare the incidence of perioperative pulmonary embolism (PE) in trauma patients with below-knee deep vein thrombosis (BKDVT) and above-knee DVT (AKDVT) who need major orthopedic surgery and evaluate the usage of inferior vena cava (IVC) filters in these cases with BKDVT.

METHODS

Between January 2003 and December 2017, patients with pelvic and/or lower extremity fracture diagnosed with DVT by duplex ultrasound were eligible for the study. A reduced-dose anticoagulation therapy was administered in patients without absolute contraindication to anticoagulation therapy during the perioperative period. Patients who did not undergo filter insertion with BKDVT were classified as the BKDVT group, and cases with thrombosis involving the popliteal or more proximal veins were classified as the AKDVT group; the incidence of PE was analyzed. Among patients with BKDVT, cases with or without filter deployment were placed in the filter group and control group, respectively, to evaluate the value of IVC filter in these patients.

RESULTS

A total of 3295 patients with pelvic and/or lower extremity fracture were diagnosed as having DVT, among which, 2070 cases did not undergo filter insertion. The incidence of PE in the BKDVT group and AKDVT group was 2.08% (24/1154) and 3.17% (29/916), respectively. A total of 366 patients with BKDVT underwent filter placement and no PE occurred. The incidence of PE in the filter group was lower than the control group. In patients without filter placement, the cases received anticoagulation therapy and those who did not, the incidence of PE was 2.21% and 1.94%, respectively, and there was no difference between the two subgroups.

CONCLUSIONS

There was no difference in incidence of PE between the AKDVT and BKDVT groups. Reduced-dose anticoagulation therapy does not affect the rates of PE in trauma patients with BKDVT who require ongoing orthopedics operations. For these patients, placement of the retrievable filter may be considered.

Outcomes of Using IVC Filters in Patients with Malignancy at an Academic Medical Center

Systemic anticoagulation is regarded as optimal treatment and prophylaxis of venous thromboembolism (VTE). In malignancy, bleeding risk is increased while the patients remain hypercoagulable, making anticoagulation management troublesome. Inferior vena cava (IVC) filters have emerged as an option in the management of VTE, especially when anticoagulant agents are contraindicated. There is limited data on the overall outcomes of patients with malignancy and IVC filter placement. This descriptive study identifies individuals with filters placed and reviews outcomes to guide appropriate care of patients with malignancy and VTE. We performed a retrospective chart review of 115 patients with malignancy who had a filter placed between July 2014 and December 2016. Eighty-seven patients were tracked until December 2017 for significant events (VTE and/or death). In total, 61% ( n  = 70) had metastatic solid tumor malignancy and 77% ( n  = 88) were receiving anticoagulation therapy prior to IVC filter placement. Fifty-three percent ( n  = 61) had bleeding events and 25% ( n  = 29) had thrombocytopenia. Patients with isolated solid tumors receiving frequent surgery were also common recipients of filters. Sixty-six percent (57/87) of patients had a significant event; 85% of them were anticoagulated. Eighty-two percent of events occurred within 6 months of filter placement, with death occurring on average within 5 months of placement. Overall, use of IVC filters was more common in cancer patients who developed bleeding complications on anticoagulation and with metastatic malignancy. However, in patients with metastatic or hematologic disease, filter placement did not prevent all-cause mortality. Individualized risk-benefit consideration is needed before IVC filters are placed.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Retrievable inferior vena cava filters in neurosurgical patients: Retrieval rates and clinical outcomes

OBJECTIVE

To assess inferior vena cava (IVC) filter retrieval rates and clinical outcomes in neurosurgical patients and to determine patient characteristics associated with filter retrieval.

PATIENTS AND METHODS

This single-center retrospective study included 204 consecutive neurosurgical patients (120 men, 84 women; mean age 60 ± 13 years) who underwent retrievable IVC filter insertion between 1/2011-9/2013. Institutional IVC filter database review was used to identify demographic and clinical data, indication for IVC filtration, and IVC filter type. Patients were followed clinically by the neurosurgical, hematology, and interventional radiology services until removal or conversion to a permanent device. Measured outcomes included filter retrieval rates and parameters associated with device removal.

RESULTS

The majority of filters were placed for venous thromboembolism (200/204, 98%). Of 204 filters, 38(19%) were retrieved at median 186 days post-placement (range 3-665 days), 112(55%) converted to permanent devices, 44(22%) patients were deceased, and 10(5%) patients were lost to follow-up after transfer to an outside healthcare facility. Patients with subarachnoid hemorrhage (18% vs. 35%, p = 0.025) and malignancy (5% vs. 25%, p = 0.009) were less likely to have filters removed. Filter type (p = 0.475), gender (p = 0.221), neurosurgical procedure (p = 0.639), and insurance status (p = 0.207) did not demonstrate a significant association with filter retrieval.

CONCLUSION

IVC filter retrieval rates in neurosurgical patients are low despite tracking patients clinically in a multidisciplinary setting. Those neurosurgical patients with intracranial hemorrhage or malignancy requiring IVC filters have a lower likelihood of filter retrieval and may benefit from use of permanent devices.

Optimal Therapy for Unstable Pulmonary Embolism

There are no randomized controlled trials of thrombolytic therapy, pulmonary embolectomy, or inferior vena cava (IVC) filters in patients with unstable pulmonary embolism (those in shock or on ventilator support). Yet, there are many investigations of these treatments based on retrospective cohort studies using administrative data from large government and commercial databases. Extensive data from these cohort studies showed that thrombolytic therapy resulted in the lowest in-hospital all-cause mortality. The results of thrombolytic therapy were greatly improved if IVC filters were added. In fact, IVC filters decreased in-hospital all-cause mortality with anticoagulants alone or with pulmonary embolectomy as well as thrombolytic therapy in adults of all ages with unstable pulmonary embolism. The IVC filters reduced mortality only if inserted on the day of admission or the next day, while the patients were unstable and in a fragile condition. We conclude that the best treatment for patients with unstable pulmonary embolism is thrombolytic therapy combined with an IVC filter inserted during the period of fragility, while the patient is unstable, and this treatment is indicated in all unstable patients irrespective of age.

Inferior Vena Cava Filters in Patients with Recurrent Pulmonary Embolism

BACKGROUND

There are sparse data to support the recommendation for inferior vena cava (IVC) filters in patients with recurrent pulmonary embolism while on anticoagulant therapy.

METHODS

This was a retrospective cohort study of administrative data from the Premier Healthcare Database, 2009-2014. All-cause mortality according to the use of IVC filters was evaluated in patients who suffered a recurrent pulmonary embolism within 3 months of an index pulmonary embolism. Patients were identified by International Classification of Disease, 9th Clinical Modification codes. A time-dependent analysis controlled for immortal time bias.

RESULTS

An IVC filter was inserted in 603 of 814 (74.1%) of patients hospitalized for recurrent pulmonary embolism within 3 months of an index pulmonary embolism. Mortality with an IVC filter was 18 of 603 (3.0%) vs 83 of 211 (39.3%) (P < .0001) without a filter. Among patients with recurrent pulmonary embolism who were stable and did not receive thrombolytic therapy or undergo pulmonary embolectomy, mortality with an IVC filter was 15 of 572 (2.6%) vs 72 of 169 (42.6%) (P < .0001) without a filter.

CONCLUSION

In the United States, usual practice was to insert an IVC filter in patients with early recurrent pulmonary embolism. Mortality was lower in those who received an IVC filter. Even stable patients with early recurrent pulmonary embolism showed a decreased mortality with IVC filters, even though in other circumstances, IVC filters do not reduce mortality in stable patients. Additional cohort studies would be useful in the absence of a randomized controlled trial.

Complementary role of intervention radiology in palliative care in oncology setting

Owing to advances in treatment of cancer, there has been increase in life expectancy. Palliative care aims at improving quality of life of patients suffering from malignancy and is now recognized as a separate subspecialty. Management of cancer patients needs a multidisciplinary approach, and radiology has a key role to play at every step of it. Interventional radiology has broadened its scope immensely over the last decade with development of newer and less invasive applications useful in oncology and palliative care. The role of interventional radiologists begins from obtaining tissue for histopathological examination and extends to controlling disease spread with ablation or chemoembolization, to managing the tumor-related complications and relieving stressful symptoms such as dyspnea and pain. This article aims to review the interventional radiologist's arsenal in managing patients with malignancies with a special emphasis on palliative care, providing a more holistic approach in improving the quality of life of cancer patients.

Clinical Outcomes of a Preoperative Inferior Vena Cava Filter in Acute Venous Thromboembolism Patients Undergoing Abdominal-Pelvic Cancer or Orthopedic Surgery

Purpose

Surgery is the most common risk factor for pulmonary embolism (PE) in patients with a recent venous thromboembolism (VTE). This study reviewed clinical outcomes of preoperative inferior vena cava filter (IVCF) use in patients with acute VTE during abdominal-pelvic cancer or lower extremity orthopedic surgeries.

Materials and Methods

We retrospectively analyzed 122 patients with a recent VTE who underwent IVCF replacement prior to abdominal-pelvic cancer or lower extremity orthopedic surgery conducted between January 2010 and December 2016. Demographics, clinical characteristics, postoperative IVCF status, risk factors for a captured thrombus, and clinical outcomes were collected for these subjects.

Results

Among the 122 study patients who were diagnosed with acute VTE in the prior 3 months and underwent preoperative IVCF replacement, 70 patients (57.4%) received abdominal-pelvic cancer surgery and 52 (42.6%) underwent lower extremity orthopedic surgery. There were no perioperative complications associated with IVCF in the study population and no cases of symptomatic PE postoperatively. A captured thrombus in the filter was identified postoperatively in 16 patients (13.1%). Logistic regression analysis indicated that postoperative anticoagulation within 48 hours significantly reduced the risk of a captured thrombus (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.08–0.94; P=0.032).

Conclusion

A captured thrombus in preoperative IVCF was identified postoperatively in 16 patients (13.1%). Postoperative anticoagulation within 48 hours reduces the risk of captured thrombus in these cases.

A survey of vascular specialists' practice patterns of inferior vena cava filter placement and retrieval

OBJECTIVES

The placement of inferior vena cava filters (IVCF) continues to rise. Vascular specialists adopt different practices based on local expertise. This study was performed to assess the attitudes of vascular specialists towards the placement and retrieval of IVCF.

METHODS

An online survey of 28 questions related to practice patterns regarding IVCF was administered to 1429 vascular specialists. Vascular specialists were categorized as low volume if they place less than three IVCF per month and high volume if they place at least three IVCF per month. The responses of high volume and low volume were compared using two-sample t-tests and Chi-square tests.

RESULTS

A total of 259 vascular specialists completed the survey (18% response rate). There were 191 vascular surgeons (74%) and 68 interventional radiologists (26%). The majority of responders were in academic practice (67%) and worked in tertiary care centers (73%). The retrievable IVCF of choice was Celect (27%) followed by Denali (20%). Forty-two percent used a temporary IVCF and left it in situ instead of using a permanent IVCF. Eighty-two percent preferred placing the tip of the IVCF at or just below the lowest renal vein. Thirty-one percent obtained a venous duplex of the lower extremities prior to retrieval while 24% did not do any imaging. There were 132 (51%) low volume vascular specialists and 127 (49%) high volume vascular specialists. Compared to low volume vascular specialists, significantly more high volume vascular specialists reported procedural times of less than 30 min for IVCF retrieval (57% vs. 42%, P = 0.026). There was a trend for high volume to have fewer unsuccessful attempts at IVCF retrieval but that did not reach statistical significance ( P = .061). High volume were more likely to have attempted multiple times to retrieve an IVCF (66% vs. 33%, P < .001), and to have used bronchoscopy forceps (32% vs. 14%, P = .001) or a laser sheath (14% vs. 2%, P < .001) for IVCF retrieval. In general, vascular specialists were not comfortable using bronchoscopy forceps (65%) or a laser sheath (82%) for IVCF retrieval.

CONCLUSIONS

This study underscores significant variability in vascular specialists practice patterns regarding IVCF. More studies and societal guidelines are needed to define best practices.

Factors Affecting Inferior Vena Cava Filter Retrieval: A Review

Objective:

Over the last 2 decades, there has been an exponential rise in placement of retrievable inferior vena cava (IVC) filters, while the retrieval rate has remained steadily low. Approaches to increasing filter retrieval rates have been extensively studied.

Conclusion:

This review presents an up-to-date review of reported data-driven variables that affect retrieval rates of IVC filters, with a focus on clinical, technical, and process factors.

Practice Patterns of Inferior Vena Cava Filter Placement and Factors That Predict Retrieval Rates: A Single-Center Institution and Review of the Literature

Background

There is a wide variability in practice patterns on the use of inferior vena cava filters (IVCFs) among institutions, which is likely due to contrasting indication guidelines published by different professional societies. The aim of the present study is to report our healthcare system use of IVCF to: 1) determine practice patterns, 2) determine factors that may predict IVCF retrieval and 3) identify areas for improvement.

Methods

A retrospective review of 180 consecutive IVCF placement performed between July 2014 and December 2015 was conducted.

Results

One hundred nine (60.6%) IVCFs were placed for absolute indications, 27 (15.0%) for relative indications, 26 (14.4%) prophylactically and 18 (10.0%) for unknown indications. Average age was 59.3 years. Ninety-five had active cancer. Surgical and medical services requested filter placement in 112 (62.2%) and 68 (37.8%) patients, respectively. Thirteen (7.2%) patients had a hematology consult prior to IVCF placement. Documentation of the presence of an IVCF was present in 118/127 (92.9%) discharge summaries, and outlined instructions for filter retrieval post-discharge were present in 20/124 (16.1%) cases. Only 33 (25.0%) IVCF were retrieved at a median interval of 162 days (range: 4 - 1,053 days). None of the factors of interest was found to be significantly associated with IVCF retrieval.

Conclusion

A root cause analysis identified that the lack of a structured system for IVCF tracking resulted in poor IVCF retrieval rates. This study resulted in the development of a hospital-initiated multidisciplinary team to address these issues.

Association of Inferior Vena Cava Filter Placement for Venous Thromboembolic Disease and a Contraindication to Anticoagulation With 30-Day Mortality

IMPORTANCE

Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group.

OBJECTIVE

To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018.

EXPOSURE

Inferior vena cava filter placement.

MAIN OUTCOMES AND MEASURES

Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable.

RESULTS

Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P < .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P < .001).

CONCLUSIONS AND RELEVANCE

After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation.

Inferior Vena Cava Filters and Prevention of Recurrent Pulmonary Embolism

Although inferior vena cava (IVC) filters have a clear role in preventing recurrent pulmonary embolism (PE) in patients with venous thromboembolism who cannot be anticoagulated, the role of filters in patients who are candidates for anticoagulation is controversial. With limited and conflicting data, practitioners often have to make an educated patient-specific decision when encountering this scenario. This article reviews the available data on the efficacy and risks associated with adjunctive IVC filter use to prevent recurrent PE.

Hospitalization metrics associated with hospital-level variation in inferior vena cava filter utilization for patients with venous thromboembolism in the United States: Implications for quality of care

Variation in the use of inferior vena cava filters (IVCFs) across hospitals has been observed, suggesting differences in quality of care. Hospitalization metrics associated with venous thromboembolism (VTE) patients have not been compared based on IVCF utilization rates using a national sample. We conducted a descriptive retrospective study using the Nationwide Readmissions Database (NRD) to delineate the variability of hospitalization metrics across the hospital quartiles of IVCF utilization for VTE patients. The NRD included all-payer administrative inpatient records drawn from 22 states. Adult (≥ 18 years) patients with VTE hospitalizations with or without IVCF were identified from January 1, 2013 through December 31, 2014 and hospitals were divided into quartiles based on the IVCF utilization rate as a proportion of VTE patients. Primary outcome measures were observed rates of in-hospital mortality, 30-day all-cause readmissions and VTE-related readmissions, cost, and length of stay. Patient case-mix characteristics and hospital-level factors by hospital quartiles of IVCF utilization rates, were compared. Overall, 12.29% of VTE patients had IVCF placement, with IVCF utilization ranging from 0% to 46.84%. The highest quartile had fewer pulmonary embolism patients relative to deep vein thrombosis patients, and older patient ages were present in higher quartiles. The highest quartile of hospitals placing IVCFs were more often private, for-profit, and non-teaching. Patient and hospital characteristics and hospitalization metrics varied by IVCF utilization rates, but hospitalization outcomes for non-IVCF patients varied most between quartiles. Future work investigating the implications of IVCF utilization rates as a measure of quality of care for VTE patients is needed.

Trends in vena cava filter insertions and "prophylactic" use

BACKGROUND

Prophylactic vena cava filter (VCF) use in patients without venous thromboembolism is common practice despite ongoing controversy. Thorough analysis of the evolution of this practice is lacking. We describe trends in VCF use and identify events associated with changes in practice.

METHODS

Using the National Inpatient Sample, we conducted a retrospective observational study of U.S. adult hospitalizations from 2000 to 2014. Trends in prophylactic VCF insertion were analyzed both across the entire study population and within subgroups according to trauma status and type of concurrent surgery. Annual percentage change (APC) was calculated, and trends were analyzed using Poisson regression.

RESULTS

Among 461,904,314 adult inpatients (median [interquartile range] age, 58.1 [38.5-74.3] years; 39.6% male), the incidence of VCF insertion increased rapidly at first (from 0.19% to 0.35%; APC, 11.2%; 95% confidence interval [CI], 10.3%-12.2%; P < .001), then at a slower rate after the publication of the Prévention du Risque d'Embolie Pulmonaire par Interruption Cave 2 (PREPIC2) trial in 2005 (from 0.35% to 0.42%; APC, 4.4%; 95% CI, 2.8%-6.0%; P < .001), and it began decreasing after the 2010 Food and Drug Administration (FDA) safety alert (from 0.42% to 0.32%; APC, -5.5%; 95% CI, -6.5% to -4.6%; P < .001). The percentage of total VCFs that had a prophylactic indication increased quickly before publication of the PREPIC2 trial (APC, 19.5%; 95% CI, 17.9%-21.0%; P < .001), increased at a slower rate after publication in 2005 (APC, 4.4%; 95% CI, 2.6%-6.2%; P < .001), and dropped after the FDA safety alert, stabilizing at 18.5% for the last 3 years (APC, -0.3%; 95% CI, -2.2% to 1.7%; P = .8). Subgroups most associated with prophylactic VCF insertion were operative trauma (odds ratio [OR], 10.9; 95% CI, 10.2-11.7), orthopedic surgery (OR, 4.7; 95% CI, 4.3-5.2), and neurosurgical procedures (OR, 3.9; 95% CI, 3.6-4.2). All groups except orthopedic surgery experienced a deceleration in prophylactic VCF growth after the publication of PREPIC2. Meanwhile, the FDA safety alert was associated with a decrease in prophylactic VCF insertions for all groups except other major surgery.

CONCLUSIONS

Whereas publication of the PREPIC2 trial led to a deceleration in prophylactic VCF insertion growth, the FDA alert had a bigger impact, leading to declining rates of prophylactic VCF use. Further investigations of prophylactic insertion of VCF in trauma, orthopedic, and neurosurgical patients are needed to determine whether current levels of use are justified.

Indications, retrieval rate, and complications of inferior vena cava filters: Single-center experience in Saudi Arabia

BACKGROUND:

Inferior vena cava (IVC) filter is indicated in patients with acute venous thromboembolism (VTE) in whom therapeutic anticoagulation is contraindicated. While prophylactic insertion of an IVC filter may be considered for patients at high risk of VTE, there are significant differences between clinical guidelines on the role of IVC filters. These discrepancies have arisen predominantly because of the paucity of data on the efficacy and safety of IVC filters. We, therefore, evaluated the indications for filter insertion, the rate of filter retrieval and complications in patients who received IVC filters at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia.

METHODS:

A descriptive, retrospective review of electronic- and paper-based medical records was performed. Consecutive sampling was used to study all adult patients who received an IVC filter at KAMC between 2007 and 2016 and met the inclusion criteria.

RESULTS:

A total of 382 IVC filters were inserted. 113 patients (30%) had an acute VTE and a contraindication to anticoagulation while 53 patients (14%) received an IVC filter in the absence of VTE (i.e., prophylactic). Only 124 (32.5%) IVC filters were eventually retrieved. The most common reason for nonretrieval was the need for permanent filtration (155, 60%). Thrombotic complications developed in 72 (19%) patients; nine patients had fatal pulmonary embolism.

CONCLUSION:

The insertion of IVC filters in this cohort was associated with low retrieval rate and relatively high incidence of thrombotic complications. Follow-up of patients is required to detect IVC filter-related complications and to increase retrieval rate.

Retrievable inferior vena cava filter utilization in obstetric patients

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

Development of a predictive model for 6 month survival in patients with venous thromboembolism and solid malignancy requiring IVC filter placement

PURPOSE

Our purpose was to develop a predictive model for short-term survival (i.e. <6 months) following inferior vena cava filter placement in patients with venous thromboembolism (VTE) and solid malignancy.

METHODS

Clinical and laboratory parameters were retrospectively reviewed for patients with solid malignancy who received a filter between January 2009 and December 2011 at a tertiary care cancer center. Multivariate Cox proportional hazards modeling was used to assess variables associated with 6 month survival following filter placement in patients with VTE and solid malignancy. Significant variables were used to generate a predictive model.

RESULTS

397 patients with solid malignancy received a filter during the study period. Three variables were associated with 6 month survival: (1) serum albumin [hazard ratio (HR) 0.496, P < 0.0001], (2) recent or planned surgery (<30 days) (HR 0.409, P < 0.0001), (3) TNM staging (stage 1 or 2 vs. stage 4, HR 0.177, P = 0.0001; stage 3 vs. stage 4, HR 0.367, P = 0.0002). These variables were used to develop a predictive model to estimate 6 month survival with an area under the receiver operating characteristic curve of 0.815, sensitivity of 0.782, and specificity of 0.715.

CONCLUSIONS

Six month survival in patients with VTE and solid malignancy requiring filter placement can be predicted from three patient variables. Our predictive model could be used to help physicians decide whether a permanent or retrievable filter may be more appropriate as well as to assess the risks and benefits for filter retrieval within the context of survival longevity in patients with cancer.

Are too many inferior vena cava filters used? Controversial evidences in different clinical settings: a narrative review

The use of inferior vena cava filters to prevent pulmonary embolism is increasing mainly because of indications that appear to be unclearly codified and recommended. The evidence supporting this approach is often heterogeneous, and mainly based on observational studies and consensus opinions, while the insertion of an IVC filter exposes patients to the risk of complications and increases health care costs. Thus, several proposed indications for an IVC filter placement remain controversial. We attempt to review the proof on the efficacy and safety of IVC filters in several "special" clinical settings, and assess the robustness of the available evidence for any specific indication to place an IVC filter.

Patient and hospital characteristics predictive of inferior vena cava filter usage in venous thromboembolism patients: A study from the 2013 to 2014 Nationwide Readmissions Database

To examine the association between patient and hospital characteristics and inferior vena cava filter (IVCF) utilization in patients with venous thromboembolism (VTE).The 2013 to 2014 Nationwide Readmissions Database was used to define a cohort of patients with VTE aged ≥18 after a primary VTE diagnosis. Comorbidities of interest were classified via diagnosis codes and IVCF placement was identified via procedure code. Chi square analysis tested differences between patient and hospital-level characteristics and whether or not IVCFs were placed. A hierarchical logistic regression model estimated the relationship between patient-level factors (demographics, socioeconomic status, comorbidities), hospital-level factors (bed size, teaching status, urbanity) and whether or not IVCFs were placed. Additional models were specified to examine goodness of fit across methodological alternatives.There were 212,395 VTE hospitalizations, with 12.18% (n = 25,877) receiving IVCF placement. There were significant differences between those who did and did not receive IVCF placement; notably, those receiving IVCFs were older (P < .001), had Medicare insurance more than private (P < .001), longer lengths of stay (P < .001), and were in privately owned hospitals (P < .001). IVCF placement remained significantly associated with patient and hospital-level characteristics following multivariate adjustment via hierarchical logistic regression; notably, age >80 (adjusted Odds Ratio [aOR]: 2.53, 95% confidence interval [CI]: 2.25-2.85), ≥13 comorbid conditions (aOR: 3.85, 95% CI: 3.25-4.27), and privately owned hospitals (aOR: 1.21, 95% CI: 1.08-1.36). Optimal goodness-of-fit was achieved with a combination of random effects and patient-level fixed effects.These findings provide evidence that combinations of patient and hospital-level factors are related to whether patients with VTE receive IVCFs.

Catheter-directed thrombolysis of deep vein thrombosis: literature review and practice considerations

Deep vein thrombosis (DVT) is a major health problem worldwide. The risk of pulmonary embolism following DVT is well established, but the long-term vascular sequelae of DVT are often underappreciated, costly to manage, and can have extremely detrimental effects on quality of life. Treatment of DVT classically involves oral anticoagulation, which reduces the risk of pulmonary embolism but does not remove the clot. Anticoagulation therefore does little to prevent the venous damage and scarring that occurs following DVT, leaving the patient at risk for permanent venous insufficiency and development of post-thrombotic syndrome (PTS). Catheter-directed thrombolysis (CDT) is a minimally invasive endovascular treatment that is used as an adjunct to anticoagulation. CDT lowers the risk of PTS by reducing clot burden and protecting against valvular damage. A catheter is advanced directly to the site of thrombosis under fluoroscopy followed by a slow, prolonged infusion of a relatively low dose of thrombolytic agent. CDT restores venous patency faster than anticoagulation, which hastens the relief of acute symptoms. Adjunctive CDT modalities have become increasingly popular among interventional radiologists, allowing for additional mechanical thrombectomy or ultrasound-enhanced thrombolysis at the time of catheter placement. These pharmacomechanical CDT (PCDT) techniques have the potential to reduce treatment time and associated healthcare costs. Numerous observational and retrospective studies have consistently shown a benefit of CDT plus anticoagulation over anticoagulation alone for prevention of PTS. Patients with long life expectancy and acute thrombosis involving the iliac and proximal femoral veins (iliofemoral DVT) have the greatest benefit from CDT, which may decrease the risk of PTS and/or decrease the severity of PTS symptoms if they do occur. Randomized controlled trials remain limited but generally support the observational data. CDT also plays an important role in those with acute limb-threatening venous occlusion or severe symptoms from DVT. Although adverse outcomes are rare, a potential devastating outcome is intracranial bleeding. While the available literature suggests the risk of serious morbidity from bleeding is quite rare, the absolute risk of bleeding is not clear and will require outcomes data from randomized trials. Future studies should also examine the cost-effectiveness of CDT for PTS prevention, particularly with respect to quality-adjusted life years, and compare the effectiveness of available PCDT devices.

Inferior Vena Cava Filters: Current and Future Concepts

The inferior vena cava filter clinical environment is notable for the degree of controversy, uncertainty, and fear associated with these devices by both physicians and the public. This article reviews some of the more important current issues with these devices as well as emerging and future trends.

Interventional Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a serious and prevalent cause of vascular disease. Nevertheless, optimal treatment for many phenotypes of PE remains uncertain. Treating PE requires appropriate risk stratification as a first step. For the highest-risk PE, presenting as shock or arrest, emergent systemic thrombolysis or embolectomy is reasonable, while for low-risk PE, anticoagulation alone is often chosen. Normotensive patients with PE but with indicia of right heart dysfunction (by biomarkers or imaging) constitute an intermediate-risk group for whom there is controversy on therapeutic strategy. Some intermediate-risk patients with PE may require urgent stabilization, and ≈10% will decompensate hemodynamically and suffer high mortality, though identifying these specific patients remains challenging. Systemic thrombolysis is a consideration, but its risks of major and intracranial hemorrhages rival overall harms from intermediate PE. Multiple hybrid pharmacomechanical approaches have been devised to capture the benefits of thrombolysis while reducing its risks, but there is limited aggregate clinical experience with such novel interventional strategies. One method to counteract uncertainty and generate a consensus multidisciplinary prognostic and therapeutic plan is through a Pulmonary Embolism Response Team, which combines expertise from interventional cardiology, interventional radiology, cardiac surgery, cardiac imaging, and critical care. Such a team can help determine which intervention-catheter-directed fibrinolysis, ultrasound-assisted thrombolysis, percutaneous mechanical thrombus fragmentation, or percutaneous or surgical embolectomy-is best suited to a particular patient. This article reviews these various modalities and the background for each.

Consequences of Venous Thromboembolism, Including Chronic Thromboembolic Pulmonary Hypertension

Venous thromboembolism includes both deep vein thrombosis and pulmonary embolism. They pose a significant risk for morbidity and mortality. In an appropriate clinical setting, invasive interventions, including administration of thrombolytics, anticoagulation, and placement of vena cava filter, are warranted. Bleeding, postthrombotic syndrome, recurrence, and filter-associated complications are few of the complications of this disease. More recently, chronic thromboembolic pulmonary hypertension has gained clinical interest in patients with pulmonary embolism and has warranted close follow-up.