Vena cava filters and inferior vena cava thrombosis

The Clinical Rationale for the Sentry Bioconvertible Inferior Vena Cava Filter for the Prevention of Pulmonary Embolism

The Sentry inferior vena cava (IVC) filter is designed to provide temporary protection against pulmonary embolism (PE) during transient high-risk periods and then to bioconvert after 60 days after implantation. At the time of bioconversion, the device's nitinol arms retract from the filtering position into the caval wall. Subsequently, the stable stent-like nitinol frame is endothelialized. The Sentry bioconvertible IVC filter has been evaluated in a multicenter investigational-device-exemption pivotal trial (NCT01975090) of 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, and with contraindications to anticoagulation. Successful filter conversion was observed in 95.7% of patients at 6 months (110/115) and 96.4% at 12 months (106/110). Through 12 months, there were no cases of symptomatic PE. The rationale for development of the Sentry bioconvertible device includes the following considerations: (1) the period of highest risk of PE for the vast majority of patients occurs within the first 60 days after an index event, with most of the PEs occurring in the first 30 days; (2) the design of retrievable IVC filters to support their removal after a transitory high-PE-risk period has, in practice, been associated with insecure filter dynamics and time-dependent complications including tilting, fracture, embolization, migration, and IVC perforation; (3) most retrievable IVC filters are placed for temporary protection, but for a variety of reasons they are not removed in any more than half of implanted patients, and when removal is attempted, the procedure is not always successful even with advanced techniques; and (4) analysis of Medicare hospital data suggests that payment for the retrieval procedure does not routinely compensate for expense. The Sentry device is not intended for removal after bioconversion. In initial clinical use, complications have been limited. Long-term results for the Sentry bioconvertible IVC filter are anticipated soon.

The Development of Marked Collateral Circulation due to Inferior Vena Cava Filter Occlusion in a Patient with Chronic Thromboembolic Pulmonary Hypertension Complicated with Anti-phospholipid Syndrome

A 30-year-old Japanese man was diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH) with lupus anticoagulants (LAs) in 2003. He underwent pulmonary endarterectomy after the placement of an inferior vena cava filter (IVCF) in 2004, and treatment with warfarin was continued. In 2014, IVCF occlusion and marked collateral circulation were noted during an examination for transient dyspnea; however, his warfarin level was within the therapeutic range for 88.9% of the time from 2003 to 2014. We herein report a rare case of CTEPH and LAs with IVCF occlusion; in such cases, intense treatment may be required.

Etiology and treatment of acute inferior vena cava thrombosis

Inferior vena cava thrombosis (IVCT) is a rare but severe disease that is associated with a high rate of mortality. IVCT can be categorized into primary versus secondary thrombosis dependent upon the underlying pathophysiology. The diagnosis includes both clinical probability assessment as well as the imaging evaluation. The optimal therapeutic strategy remains the target of continued research. Although anticoagulation therapy remains fundamental in treating IVCT, its inherent limitations have led to the use of minimally invasive, endovascular treatment options, including transcatheter thrombolysis, mechanical thrombectomy or a combination of these techniques. This review focuses on the etiology, diagnostic assessment, and endovascular treatment options for IVCT.

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.

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.

Inferior vena cava occlusion causing syncope during upper extremity exertion treated with iliocaval venous revascularization

Inferior vena cava (IVC) thrombosis is rare, but its incidence is increased in those with IVC filters or inflammatory bowel disease. Once the IVC is thrombosed, venous return is via collateral channels on the torso and retroperitoneum. Limitations in this collateral venous return can result in symptoms, usually in the lower extremities. Syncope and dyspnea are rare. We report a patient with a 1-year history of worsening syncope when working with his upper extremities. Iliocaval venous occlusion with lack of accommodation of venous return at the thoracic outlet was diagnosed. Treatment with iliocaval stenting resolved his symptoms.

Percutaneous Removal of Filter-Induced Iliocaval Thrombus Using the AngioVac Device

Most percutaneous mechanical thrombectomy devices entail thrombolysis and/or thrombus fragmentation followed by subsequent aspiration, with the associated risks of bleeding and embolization. We describe the use of the AngioVac system (Angiodynamics, Latham, NY USA) for extraction of extensive iliocaval thrombus associated with an inferior vena cava filter followed by percutaneous inferior vena cava filter extraction in a patient with an absolute contraindication to thrombolysis. The AngioVac may be considered in this scenario as it does not require thrombolytics and can remove whole thrombus, thus overcoming some of the limitations of percutaneous mechanical thrombectomy devices in the setting of subacute and early chronic thrombus.

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.

Vena cava filter practices of a regional vascular surgery society

BACKGROUND

Vena cava filter (VCF) use in the United States has increased dramatically with prophylactic indications for placement and the availability of low-profile retrievable devices, which are overtaking the filter market. We surveyed the practice patterns of a large group of vascular surgeons from a regional vascular surgery society to see whether they mirrored current national trends.

METHODS

A 17-question online VCF survey was offered to all members of the Southern Association of Vascular Surgery. The responses were analyzed using the χ(2) goodness of fit tests.

RESULTS

Of the 276 members surveyed, 126 (46%) responded, with 118 (93%) indicating that they placed filters during their practice. Highly significant differences were identified with each question (at least P < 0.002). Regarding the inferior vena cava, the preferred permanent filters were the Greenfield (31%), the TrapEase (15%), the Vena Tech (5%), and a variety of retrievable devices (49%). Fifty percent of the respondents placed retrievable filters selectively; 26% always placed them; and 24% never did. Filters were placed for prophylactic indications <50% of the time by 63% of the respondents. Overall, retrievable filters (when not used as permanent filters) were removed <25% of the time by 64% of the respondents and <50% of the time by 78% of the respondents. The femoral vein was the preferred access site for 84% of the respondents. Major complications were few but included filter migration to the atrium (one), atrial perforation (one), abdominal pain requiring surgical filter removal (two), inferior vena cava thrombosis (12 vena cava thrombosis--4 due to TrapEase filters), strut fracture with embolization to heart or lungs (three Bard retrievable filters), and severe tilting precluding percutaneous retrieval and protection from pulmonary emboli (8 filters with severe tilt--7 of which were Bard). Of the respondents, 59% had never placed a superior vena cava filter, and 28% had placed five or fewer.

CONCLUSIONS

Although VCF insertion overall appears safe, some complications are specific to biconical and certain retrievable filters. Given the low removal rate and lack of long-term experience with retrievable filters, routine use of these devices as permanent filters should be questioned. If used on a temporary basis, there should be a plan for filter removal at the time of implantation.

Vena cava thrombosis after vena cava filter placement: Incidence and risk factors

BACKGROUND

The objective of this study was to assess the clinical safety and efficacy of vena cava filter (VCF) placement, with particular emphasis on the incidence and risk factors of inferior vena cava thrombosis (VCT) after VCF placement.

METHODS

Clinical data of patients with venous thromboembolism (VTE), with or without placement of VCF, were analyzed in a retrospective single-center audit of medical records from January 2005 to June 2009. The collected data included demographics, procedural details, filter type, indications, and complications.

RESULTS

A total of 168 cases of VTE (82 with VCF; 86 without VCF) were examined. Over a median follow-up of 24.2 months, VCT occurred in 18 of 82 patients with VCFs (11 males, 7 females, mean age 55.4 years). In 86 patients without VCFs, VCT occurred in only 6 individuals (4 males, 2 females) during the study period. VCT was observed more frequently in patients fitted with VCFs than in those without VCFs (22% vs. 7.0%).

CONCLUSIONS

The incidence of VCT in patients with VTE after VCF implantation was 22% approximately. Anticoagulation therapy should be continued for all patients with VCF placement, unless there is a specific contraindication. Almost all instances of VCT in patients with VCF implants in our study occurred after stopping anticoagulation treatment. The use of VCFs is increasing, and more trials are needed to confirm their benefit and accurately assess their safety.

Use of inferior vena cava filters in a tertiary referral centre in Australia

INTRODUCTION

To investigate the use of inferior vena cava (IVC) filters in a tertiary referral centre, looking at indication, types of filters and, with temporary/optional filters, removal rates.

METHODS

Data was collected from a prospective database of all IVC filters inserted from January 2003 to January 2007. Patients' records and radiological imaging were all reviewed.

RESULTS

66 patients (40 males) had IVC filters inserted during the study period. The median age of the male patients was 57.5 (21-79) years, and females 56 (24-81). There were 49 (74.2%) temporary/optional filters and 17 (25.8%) permanent filters. The most common indication for filter was a contraindication to anticoagulation for both permanent (64.7%) and temporary/optional filters (77.6%). In the temporary/optional filter group, 38 of 49 (77.6%) patients had documented venous thromboembolism, while in the permanent filter group, this was 14 of 17 (82.4%). Of the optional filters, 22 of 49 (45.8%) have been removed.

CONCLUSION

More than half (54.2%) of temporary/optional filters were not removed and with potential for long-term complications. A protocol has now being instituted for vascular surgeons to authorize the insertion of filters and to then be responsible for ensuring their removal.

[Vena cava filters in trauma patients]

BACKGROUND

The introduction of removable inferior vena cava filters (IVCF) has created new options for the prevention of pulmonary embolisms in surgical trauma patients. We have observed increasing use in trauma patients.

PATIENTS AND METHODS

A retrospective analysis was carried out of 49 trauma patients out of 85 who received IVCFs at our level 1 trauma centre in 2008.

RESULTS

The indications for IVCF placement were multiple trauma in 33 patients, severe head injury in 13 and spinal injury in 3 patients. Of the patients 34 underwent successful removal, 11 (22%) patients had had no retrieval attempt by December 2009 and attempts at removal were unsuccessful in 3 patients. The mean age of the patients was 33.3 years.

CONCLUSION

In 2008 the vast majority of IVCFs were inserted for prophylaxis in trauma patients. To increase the number of retrieved IVCFs, responsibility for the removal should be clarified in every hospital. The indications, advantages, safety and also the design of IVCFs are still under debate. A randomized controlled trial is needed to determine the appropriate use and indications for this potentially useful device in trauma patients.

Retrievable vena cava filters: a clinical review

Vena cava filters were developed as a method of preventing pulmonary embolism (PE) in patients with venous thromboembolism (VTE) at risk for bleeding from therapeutic anticoagulation. However, the long-term complications of filter placement, such as caval thrombosis, have mitigated some of the benefits, particularly in those patients with only a temporary contraindication to anticoagulation. Retrievable filters were designed to avoid the long-term risks of a permanent filter while still providing short-term protection against PE. As a result, their use has expanded from patients with known thrombosis to those without VTE who are at high risk for developing PE. In this review, we discuss the different types of retrievable filters, indications for their placement, complications that can occur during and after placement, and their use as prophylaxis in surgical patients. Although the use of retrievable filters in patients with known VTE is clear, further studies are needed to establish their prophylactic efficacy in the surgical patient. Until this evidence is available, we recommend that retrievable filters should be used only in patients with acute VTE who are at risk for recurrent thromboembolism and have a transient risk for bleeding.

Sacral preservation in cauda equina syndrome from inferior vena cava thrombosis

Acute cauda equina syndrome can occur due to a variety of causes. Inferior vena cava (IVC) thrombosis has been reported as the causal source of this phenomenon twice in the relevant literature, both cases of which presented in a form complete with a component of bowel and/or bladder dysfunction. The authors report an atypical case of cauda equina syndrome in a patient in a hypercoagulable state with an extensive IVC thrombosis, resulting in acute paraparesis in the absence of incontinence or perineal anesthesia. An increasing number of prophylactic and/or therapeutic IVC filters placed in the perioperative period should engender an increased clinical suspicion for IVC thrombosis in patients presenting with acute paraparesis.

Retrievable inferior vena cava filters in high-risk trauma and surgical patients: factors influencing successful removal

BACKGROUND

An Inferior vena cava filter (IVCF) provides prophylaxis against pulmonary embolism in patients that cannot be anticoagulated. A removable IVCF (R-IVCF) provides prophylaxis during a high-risk period while potentially eliminating long-term complications associated with a permanent IVCF. Factors influencing success of R-IVCF removal are ill-defined.

METHODS

The study was a retrospective review of a prospectively maintained patient registry comprising patients who received an R-IVCF (Bard Recovery and G2) at an academic level 1 trauma center. The influence of time in vivo, filter design, and filter head position on computed abdominal tomographic (CAT) scan (touching caval wall vs. free) on removal success was examined.

RESULTS

Ninety-two patients each received an R-IVCF. Thirty-nine patients underwent removal attempt and 30 R-IVCFs were removed. Time in vivo did not affect removal success (success: 228 +/- 104 days versus unsuccessful: 289 +/- 158 days, p = 0.18). Filter design impacted filter head position (Recovery: 43% touching versus G2: 6% touching, p = 0.023). Position of the filter head influenced removal success (touching: 50% success versus free: 88% success, p = 0.021).

CONCLUSIONS

Position of the filter head is the key determinant of removal success. Specific device designs may impact filter head position as was the case with the two designs in this analysis. Time in vivo does not affect removal success.

Form And Function Of Vena Cava Filters: How Do Optional Filters Measure Up?

The function of vena cava filters, preventing pulmonary embolism while maintaining caval patency, is associated with the design. Several characteristics have been reported. This report evaluates retrievable filter designs in comparison with previously marketed designs with respect to efficacy and safety. Three inferior vena cava (IVC) filters (Gunther Tulip, Bard Recovery, and the Cordis OptEase) were compared on the basis of design characteristics associated with function, shape, number of trapping levels, and fixation. Adverse events reported in the literature and to the US Food and Drug Administration Manufacturers and User Facility Device Experience Database (MAUDE) were summarized. The major differences among device types include the fixation, the volume and number of trapping levels, and the amount of metal in the IVC. The MAUDE registry reported adverse events that had been hypothesized from the analysis of in vitro and in vivo testing. The Recovery and OptEase filters had the highest number of clinically important reports. From 12 to 57% were retrieved between 3 days and 11 months. Adaptations made to facilitate retrieval led to unacceptable sequelae. The small number removed, the length of time they are left in place, and the risks associated with retrieval suggest that optional filters may not be equivalent to approved permanent devices.