Inferior Vena Caval Filters: Key Considerations

Acute Pulmonary Embolism: Contemporary Approach to Diagnosis, Risk-Stratification, and Management

Pulmonary embolism (PE) affects over 300,000 individuals each year in the United States and is associated with substantial morbidity and mortality. Improvements in the diagnostic performance and availability of computed tomographic pulmonary angiography and D-dimer testing have facilitated the evaluation of patients with suspected PE. High clinical suspicion is required in those with risk factors and/or those that manifest signs or symptoms of venous thromboembolic disease, with validated clinical risk scores such as the Wells and modified Wells score or the PE rule-out criteria helpful in estimating the likelihood for PE. For those with confirmed PE, patients should be categorized and triaged according to the presence or absence of shock or hypotension. Normotensive patients can be further risk-stratified using validated prognostic risk scores, as well as by using imaging and cardiac biomarkers, with those having either signs of right ventricular dysfunction on imaging studies and/or abnormal cardiac biomarkers categorized as being at intermediate-risk and requiring close monitoring and hospital admission. Early discharge and/or home therapy are possible in those that do not manifest any high-risk features. The initial treatment for most patients that are stable consists of anticoagulation, with advanced therapies such as thrombolysis, catheter-based therapies, or surgical embolectomy deferred for those at high risk. Given the heterogeneous presentations of PE and various management strategies available, the development of multidisciplinary PE response teams has emerged to help facilitate decision-making in these patients.

Retrievable vena cava filters: a clinical review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism (PE), is a major cause of morbidity and mortality. Parenteral anticoagulant treatment with full-dose unfractioned heparin, low-molecular-weight-heparin, or fondaparinux, followed by oral treatment with the vitamin K antagonists, is recommended for the majority of patients. However, in the presence of contraindications to anticoagulant treatment, bleeding complications during antithrombotic treatment, or VTE recurrences despite optimal anticoagulation, interruption of the inferior vena cava with a filter is a potential option aimed to prevent life-threatening PE. Currently, the vast majority of filters implanted worldwide are of the permanent type, but their use is associated with a number of long term complications. Non-permanent filters represent an important alternative, and in particular retrievable filters are an attractive option because they may be either left in place permanently or safely retrieved after a quite long period when they become unnecessary. In this review, we summarize the currently available literature regarding retrievable vena cava filters and we discuss current evidences on their efficacy and safety. Moreover, the appropriate indications for their use in daily clinical practice are reviewed.

Interventional treatment of venous thromboembolism: a review

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most common cardiovascular disease after coronary artery disease and cerebrovascular disease and is responsible for significant morbidity and mortality in the general population. Full dose anticoagulation is the standard therapy for VTE, both for the acute and the long-term phase. The latest guidelines of the American College of Chest Physicians recommend treatment with a full-dose of unfractioned heparin (UFH), low-molecular-weight-heparin (LMWH), fondaparinux, vitamin K antagonist (VKA) or thrombolysis for most patients with objectively confirmed VTE. Catheter-guided thrombolysis and trombosuction are interventional approaches that should be used only in selected populations; interruption of the inferior vena cava (IVC) with a filter can be performed to prevent life-threatening PE in patients with VTE and contraindications to anticoagulant treatment, bleeding complications during antithrombotic treatment, or VTE recurrences despite optimal anticoagulation. In this review we summarize the currently available literature regarding interventional approaches for VTE treatment (vena cava filters, catheter-guided thrombolysis, thrombosuction) and we discuss current evidences on their efficacy and safety. Moreover, the appropriate indications for their use in daily clinical practice are reviewed.

Current status and trends in the treatment of acute pulmonary thromboembolism

Untreated acute pulmonary thromboembolism (APTE) is associated with high mortality, which is reduced by prompt treatment. Anticoagulation is fundamental in the treatment of APTE and should be initiated from suspicion. The efficacy and safety of novel anticoagulant drugs, such as oral anti-Xa and anti-IIa inhibitors, are topics in the treatment of APTE and are now under investigation. Thrombolytic therapy is a widely accepted treatment strategy for massive APTE, but its use for submassive APTE is controversial. Catheter intervention, percutaneous cardiopulmonary support and surgical embolectomy are also necessary and effective for some patients with APTE. A retrievable inferior vena cava filter is preferred for transient protection against APTE. Some studies have demonstrated the feasibility of outpatient treatment in patients with APTE after risk stratification.

Inferior vena caval filters: 5 years of experience in a tertiary care center

BACKGROUND AND OBJECTIVES

Interruption of the Inferior Vena Cava (IVC) is recommended in certain cases to prevent Pulmonary Embolism (PE). Reported data on the efficacy and rate of complications vary considerably.

PATIENTS AND METHODS

We conducted a retrospective analysis of patients who had a temporary or permanent IVC filter inserted at our institution during the past 5 years.

RESULTS

Seventy-seven of 225 patients (34%) with Venous Thrombosis (VT) had an IVC filter inserted. Deep vein thrombosis and PE were the most common causes for anticoagulation. Bleeding was the reason for IVC filter insertion in 48 (62%). The only complication found was the breaking of a temporary filter during removal related to the procedure. However, 3 patients (out of 10) had a recurrence of VT after prolonged discontinuation of anticoagulation.

CONCLUSIONS

Our criteria for indication of IVC filter insertion are in line with current standard of care. The immediate and delayed complications caused by IVC filter insertion was low. Active bleeding was the most common indication for filter insertion, whereas inherited thrombophilia was relatively common.

IVC filters may prevent fatal pulmonary embolism in musculoskeletal tumor surgery

To determine whether inferior vena cava (IVC) filter placement protects patients with musculoskeletal tumors from fatal pulmonary embolisms (PE), we retrospectively analyzed the records of 81 patients who underwent surgery for pelvic and lower extremity malignancies. All 81 patients received an IVC filter and mechanical compression for deep venous thrombosis (DVT) prophylaxis, but no pharmacologic anticoagulation. Duplex imaging was performed before hospital discharge and when clinical suspicion of DVT arose. Seventy-six of the 81 (94%) patients were followed at least 3 months (mean, 21.3 months; range, 3-77 months) postoperatively. We reviewed the perioperative medical records and office visit notes to determine the rate of clinically evident DVT, symptomatic PE, wound complications, and IVC filter-related complications. DVT and PE incidences in the early postoperative period (< 30 days) were 21% (17 of 81) and 2% (two of 81), respectively. There were no known deaths from PE. Patients undergoing reconstruction surgery (n = 41) were more likely to have early DVT develop after definitive tumor surgery. Patient age, tumor type or histology, anatomic location, presence of pathologic fracture, or development of wound complications did not correlate with an increased DVT rate. Two (3%) patients had late DVT, and none had a late PE. Combining an IVC filter with mechanical limb compression prevented fatal PE in patients undergoing orthopaedic surgery for malignancies of the pelvis and lower extremity and is a reasonable form of thromboembolic prophylaxis specific for this patient population.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

Sudden cardiac death caused by migration of a TrapEase inferior vena cava filter: case report and review of the literature

CASE

A 43-year-old female presented with sudden onset of palpitations, chest pain, and shortness of breath associated with hypoxemia. A helical computed tomography (CT) scan of the chest revealed a large saddle pulmonary embolism. Intravenous tPA relieved the shortness of breath and improved the hypoxemia. Inferior vena cava (IVC) filter (TrapEase, Cordis Corp., Miami, FL, USA) was placed. On day 6 of her hospitalization, she went into cardiopulmonary arrest while walking back from the rest room. The patient died despite a prolonged attempt at cardiopulmonary resuscitation. At that time, ventricular tachycardia and then ventricular fibrillation were recorded. Autopsy of the heart showed the IVC filter entrapped within the tricuspid valve.

DISCUSSION

The incidence of IVC filter migration ranges from 0.3 to 6% with rare migration to the heart or lung (0.1-1.25%). Sudden cardiac death from migration of IVC filter is extremely rare. We report the first case of sudden cardiac death caused by migration of the TrapEase filter to the heart. There are two reports in the literature of death from migrating Greenfield and Antheor filters.

CONCLUSION

An IVC filter migration to the heart, although rare, can cause serious arrhythmia and sudden cardiac death.

Retrievable vena cava filters: Key considerations

Retrievable filters are a new generation of inferior vena cava (IVC) filters and represent an attractive option because they may be either left in place permanently or safely retrieved after a quite long period when they become unnecessary. In this review the currently available literature regarding retrievable IVC filters is summarized and their efficacy and safety is discussed. Moreover, the appropriate indications for their use are reviewed. Retrievable filters are becoming safer and easier to use; in fact the bioengineering research has optimized the technical characteristics of these devices, in order to reduce the incidence of possible complications. However, there are important unresolved issues, including the appropriate maximum implantation time, the possibility to safely and efficaciously remove the filters without being compromised by entrapped clots, and the use of anticoagulation during the implantation and periremoval periods. Large prospective cohort studies or randomized trials are strongly warranted to definitely clarify the beneficial role of these devices.

Vena Cava Filter Performance Based on Hemodynamics and Reported Thrombosis and Pulmonary Embolism Patterns

PURPOSE

Three inferior vena cava (IVC) filters of different designs were studied to identify the potential links between published clinical results for thrombosis and recurrent pulmonary embolism (PE) rates and in vitro hemodynamics patterns in the region of the filters.

MATERIALS AND METHODS

The filters studied were the Greenfield over-the-wire filter (Medi-tech/Boston Scientific, Watertown, Mass), TrapEase filter (Cordis Europa, Roden, the Netherlands), and Mobin-Uddin umbrella filter (Edwards Laboratories, Santa Ana, Calif). To assess hemodynamics, velocity contour maps were generated for each filter by using the in vitro photochromic flow visualization technique. Results were obtained for both the unoccluded and partially occluded states. Steady flow (R(e) = 600) was used to model physiologic conditions. To estimate the rates of IVC occlusion and recurrent PE, the authors analyzed published clinical studies spanning more than 30 years and a U.S. Food and Drug Administration database.

RESULTS

For both the unoccluded and partially occluded Mobin-Uddin and TrapEase filters, regions of flow stagnation and/or recirculation and turbulence developed downstream of the filter. The Greenfield filter did not produce any prothrombotic flow patterns for either the unoccluded or partially occluded states. Results of published clinical studies supported the hemodynamic findings, with the TrapEase and Mobin-Uddin filters having high rates of IVC occlusion and recurrent PE compared with those of the Greenfield filter.

CONCLUSIONS

Flow stagnation or recirculation and turbulence have been linked to thrombosis and thrombus and/or PE formation. Thus, the hemodynamic results from this study may help explain the relatively higher rates of filter thrombosis and PE for the Mobin-Uddin and TrapEase filters versus the Greenfield filter.

Mid-term Experience with the ALN Retrievable Inferior Vena Cava Filter

OBJECTIVE

To report the mid-term results of 63 patients who received a new commercially-available retrievable vena cava filter, ALN.

METHODS

Between January 2001 and October 2005, 63 patients (mean age 65 +/- 15 years) underwent placement of ALN filters. Filter removal was performed when anti-thrombotic prophylaxis was considered unnecessary or when the patient could safely resume full anticoagulant therapy.

RESULTS

Thirty-five patients (55%) had ilio-femoral venous thrombosis and 28 patients (45%) had ilio-caval thrombosis. Overall, 49% had pulmonary embolism. Technical success for filter insertion was 100%, without any complications. None of the procedures aborted or was converted due to technical difficulties. After a median follow-up of 21-months (range 1-48, median 18), there were no cases of pulmonary embolism or vena cava thrombosis. Two patients died of a cause unrelated to deep venous thrombosis during the follow-up period, without clinical evidence of pulmonary embolism or filter-associated complications. No device migration was observed. There were 20 (31.7%) retrieval attempts: in 16 cases filters were retrieved successfully, but 4 cases were aborted. The mean implantation period of the retrieved filter was 179 days (range 53-370).

CONCLUSION

Our results confirm the clinical efficacy of the ALN filter for preventing potentially fatal pulmonary embolism whilst implanted and in absence of post-insertion complications, even when left in place indefinitely.

Vena cava filters: an update

Venous thromboembolism is a major health problem that results in significant long-term complications and mortality. The management of venous thromboembolism is complex and can be particularly challenging when pharmacological therapy alone cannot be effectively utilized. Vena cava filters provide protection from pulmonary embolism for patients in whom therapeutic anticoagulation is contraindicated or inadequate. Recent innovations in caval interruption have included the use of alternative imaging modalities for filter insertion and the emergence of devices designed to allow temporary caval filtration. These developments have been accompanied by a controversial increase in the use of vena cava filters for prophylactic indications in the absence of venous thromboembolism. In addition to a brief historical perspective on caval filtration, this update reviews the indications for vena cava filter insertion, associated complications, methods of caval imaging and filter insertion and current FDA-approved devices.

Retrievable vena cava filters: a review

PURPOSE OF REVIEW

To examine the current literature regarding retrievable inferior vena cava filters and to discuss the appropriate indications for their clinical use.

RECENT FINDINGS

Permanent filters have been shown to be effective, but have a number of long-term complications such as filter thrombosis or migration. Indications for their placement should be accurately evaluated, especially in patients with a long life expectancy, or in whom the period of contraindication to anticoagulation is short. On the other hand, temporary filters are difficult to manage and their maximum implantation time is often insufficient to solve the clinical problem leading to their placement. Four different retrievable filters recently received approval for temporary insertion. Recent data suggest that the use of these filters may be related to a low rate of pulmonary embolism and insertion complications. Nevertheless, no randomized clinical trials have been performed, and the only available data refer to retrospective or prospective studies.

SUMMARY

Retrievable filters are a new generation of filter that offers the attractive possibility of being left in place permanently or being removed after quite a long period when they become unnecessary.