Treatment of patients with venous thromboembolism and malignant disease: should vena cava filter placement be routine?

Inferior Vena Cava Filter in Cancer Patients: On Whom Should We Be Placing Them?

BACKGROUND

Standard treatment for venous thromboembolism is anticoagulation; vena cava filter placement is an alternative in special situations. We aimed to evaluate the outcomes in patients with cancer undergoing filter placement in a cancer center during a 10-year period and assess which preoperatory variables were associated with poorer survival.

METHODS

Retrospective unicenter analysis during a 10-year period was carried out in patients with cancer who had undergone placement of vena cava filter. Early deaths were those that occurred less than 30 days after the filter placement or that occurred during the same hospital stay of the placement.

RESULTS

About 250 patients were analyzed. About 51.6% were females; 77.2% had proximal lower limb deep vein thrombosis; 34.8% had contraindications to anticoagulation; 32.8% presented bleeding after the onset of anticoagulation; and 18.4% had the filter implanted because they were going to undergo surgery and could not be anticoagulated immediately after. About 51.2% of the filters were removable. However, only 2 had the filter removed. About 59.2% had metastatic disease at the time of filter placement. About 31.2% fulfilled criteria for early death. Of those, 34 patients were put in palliative care after filter insertion (median, 13.5 days). Body mass index >18 kg/m², the absence of metastatic disease, and filter placement during the same anesthesia of another surgery (especially if elective and curative) were associated with a higher chance of survival.

CONCLUSIONS

Multidisciplinary evaluation (and possibly consideration for palliation) should take place before the decision to insert a vena cava filter in severe oncologic cases depending on overall status. Patients with a greater chance of survival at a 3 or 5 years interval seem to be those whose filters were placed in the perioperative context of other surgeries (specially elective and curative), who were not undernourished, and whose disease was not metastatic at that time. For patients who survived, an active investigation protocol for filter removal should be implemented.

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.

Vena Cava Filters: A Synopsis of Complications and Related Topics

Deep venous thrombosis and pulmonary embolism constitute common preventable causes of morbidity and mortality. The incidence of venous thromboembolism (VTE) continues to increase. Standard anticoagulation therapy may reduce the risk of fatal PE by 75% and that of recurrent VTE by over 90%. For patients who are not candidates for anticoagulation, a vena cava filter (VCF) may be beneficial. Despite a good overall safety record, significant complications related to VCF are occasionally seen. This review discusses both procedural and non-procedural complications associated with VCF placement and use. We will also discuss VCF use in the settings of pregnancy, malignancy, and the clinical need for more than one filter.

ANMCO Position Paper: long-term follow-up of patients with pulmonary thromboembolism

Venous thromboembolism (VTE), including pulmonary embolism and deep venous thrombosis, is the third most common cause of cardiovascular death. The management of the acute phase of VTE has already been described in several guidelines. However, the management of the follow-up (FU) of these patients has been poorly defined. This consensus document, created by the Italian cardiologists, wants to clarify this issue using the currently available evidence in VTE. Clinical and instrumental data acquired during the acute phase of the disease are the cornerstone for planning the FU. Acquired or congenital thrombophilic disorders could be identified in apparently unprovoked VTE during the FU. In other cases, an occult cancer could be discovered after a VTE. The main targets of the post-acute management are to prevent recurrence of VTE and to identify the patients who can develop a chronic thromboembolic pulmonary hypertension. Knowledge of pathophysiology and therapeutic approaches is fundamental to decide the most appropriate long-term treatment. Moreover, prognostic stratification during the FU should be constantly updated on the basis of the new evidence acquired. Currently, the cornerstone of VTE treatment is represented by both the oral and the parenteral anticoagulation. Novel oral anticoagulants should be an interesting alternative in the long-term treatment.

Inferior Vena Cava Filter Placement in Late-Stage Cancer

Inferior vena cava (IVC) filters are increasingly used in patients with advanced-stage cancer for prophylaxis of pulmonary embolus. We evaluated the survival benefit of placing IVC filters in patients with late-stage malignancy and assessed their effectiveness in preventing pulmonary embolism. Between 1998 and 2003, 5,970 patients were treated with a primary diagnosis of malignancy at a tertiary care facility. Retrospective analysis identified 55 consecutive patients with stage III or IV malignant disease and venous thromboembolism (VTE) who received IVC filters. Retrospective review of electronic hospital charts identified subsequent pulmonary emboli, procedure-related complications, and survival. In a case control study, 16 patients with VTE but without IVC filter were matched for age, sex, type of malignancy, and stage of disease. IVC filter placement effectively prevented computed tomography (CT) scan or ventilation/perfusion ratio (V/Q) scan-proven pulmonary embolus in 52/55 (94.5%) patients. Complications developed in 4/55 or 7.3% of patients; 13/55 (23.6%) patients with late-stage cancer survived less than 30 days following placement of the filter. Another 23.6% of this group survived longer than 1 year. Ambulatory status differed significantly (p=0.01) between these 2 subgroups. In the case control study, IVC filter placement conferred no survival benefit compared to the control group. One recurrent pulmonary embolism was observed in both the filter group and the control group. No deaths due to thromboembolic complications were observed in either group. In late-stage cancer, patient survival is limited primarily by the malignant process. While IVC filter placement is effective in preventing pulmonary emboli, there may be limited survival benefit in this particular patient population. However, there exists a subset of this population whose functional status predicts longer survival times after filter placement.

Vena Caval Filters: A Review for Intensive Care Specialists

Venous thromboembolism (VTE) is a common complication among patients in the intensive care unit. While anticoagulation remains standard therapy, vena caval filters are an important alternative when anticoagulation is contraindicated. To determine the safety and efficacy of vena caval filters in the treatment of VTE, a comprehensive review of the English-language medical literature was performed. Except for one randomized controlled trial, the literature supporting the use of vena caval filters consists almost exclusively of case series, which in many instances are limited by incomplete and short follow-up. While case series suggest that filters function effectively in the prevention of pulmonary embolism (2%-4% symptomatic pulmonary embolism [PE], fatal PE < 2%), recent higher quality studies indicate that filters may not provide significant additional protection to that provided by anticoagulation alone. Furthermore, filters are associated with a 2- fold increase in the incidence of recurrent DVT. Until randomized comparative studies are available, the safety and efficacy of all the available devices should be considered to be roughly equivalent. Since filters do not inhibit continued clot formation, all filter patients should receive anticoagulation for durations appropriate for their thrombotic disorder. Although extended anticoagulation may prevent thrombotic complications associated with filter placement, this strategy has yet to be experimentally tested. While many additional indications for vena caval filter use have been proposed (VTE in cancer patients, PE prophylaxis in trauma patients, etc), well-designed clinical trials demonstrating their efficacy in these situations are lacking. Further development of temporary/retrievable filters, which offer the potential to avoid the long-term complications of permanent filters, should be a research priority. Until additional data are available, vena caval filters should generally be restricted to patients with VTE who cannot receive anticoagulation.

Inferior vena cava filter usage, complications, and retrieval rate in cancer patients

BACKGROUND

Venous thromboembolism contributes significantly to morbidity and mortality in cancer patients. Because cancer patients frequently have contraindications to anticoagulation, inferior vena cava filters are commonly placed. The use, safety, and retrieval of retrievable inferior vena cava filters in cancer patients have not been well studied.

METHODS

A retrospective review of retrievable inferior vena cava filter use at a tertiary referral hospital was conducted between January 1, 2009 and December 31, 2011. Indications for inferior vena cava filter placement, anticoagulation practices, complications, filter retrieval, and patient outcomes were analyzed for patients with and without active cancer and for cancer subtypes, including localized and metastatic cases.

RESULTS

Of 666 patients receiving retrievable inferior vena cava filters during this time period, 247 (37.1%) had active cancer. Of these, 151 (22.7%) had carcinoma, 92 (13.8%) had sarcoma, and 115 (17.3%) had metastatic disease. Overall, follow-up was available for a median of 401.0 (interquartile range: 107.5-786.5) days. Indwelling filter-related complications occurred in 19.8% of patients without cancer and 17.7% with an active cancer (P = .50). Patients with cancer were less likely to have the filter retrieved (28.0% vs 42.0%, P < .001). In multivariable analysis, cancer was not associated with filter-related complications but was associated with a lower rate of filter retrieval.

CONCLUSIONS

In a modern cohort of patients undergoing retrievable inferior vena cava filter placement, active diagnosis of cancer is not associated with a significant increase in filter-related complications, but is associated with a reduced rate of filter retrieval.

Case fatality rate with vena cava filters in hospitalized stable patients with cancer and pulmonary embolism

BACKGROUND

In view of the high risk of pulmonary embolism in patients with cancer, we tested the hypothesis that stable patients with pulmonary embolism who have cancer might be a subset of patients who would show a lower case fatality rate with vena cava filters than without filters.

METHODS

Stable patients with pulmonary embolism and cancer at discharge from short-stay hospitals throughout the US from 1998-2009 were identified from the Nationwide Inpatient Sample. Patients with pulmonary embolism who had a diagnostic code for shock, ventilatory support, thrombolytic therapy, or pulmonary embolectomy were excluded because such patients have been shown to have lower case fatality rate with filters.

RESULTS

In-hospital all-cause case fatality rate was lower with vena cava filters in stable patients with pulmonary embolism and solid malignant tumors providing they were aged >30 years, but there was variability according to type of tumor and age of patient. On average, case fatality rate among those >30 years with filters was 7070 of 69,350 (10.2%) (95% confidence interval, 10.0-10.4) versus 36,875 of 247,125 (14.9%) (95% confidence interval, 14.8-15.1) without filters (P <.0001) (relative risk 0.68). Among stable patients with hematological malignancies, case fatality rate, except in the elderly, was higher among those with vena cava filters than those without filters.

CONCLUSION

Stable patients with pulmonary embolism and solid malignant tumors who are older than age 30 years appear to be a subset of patients with pulmonary embolism who would benefit from vena cava filters, but this needs to be tested prospectively.

International clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer

BACKGROUND

 Guidelines addressing the management of venous thromboembolism (VTE) in cancer patients are heterogeneous and their implementation has been suboptimal worldwide.

OBJECTIVES

To establish a common international consensus addressing practical, clinically relevant questions in this setting.

METHODS

An international consensus working group of experts was set up to develop guidelines according to an evidence-based medicine approach, using the GRADE system.

RESULTS

For the initial treatment of established VTE: low-molecular-weight heparin (LMWH) is recommended [1B]; fondaparinux and unfractionated heparin (UFH) can be also used [2D]; thrombolysis may only be considered on a case-by-case basis [Best clinical practice (Guidance)]; vena cava filters (VCF) may be considered if contraindication to anticoagulation or pulmonary embolism recurrence under optimal anticoagulation; periodic reassessment of contraindications to anticoagulation is recommended and anticoagulation should be resumed when safe; VCF are not recommended for primary VTE prophylaxis in cancer patients [Guidance]. For the early maintenance (10 days to 3 months) and long-term (beyond 3 months) treatment of established VTE, LMWH for a minimum of 3 months is preferred over vitamin K antagonists (VKA) [1A]; idraparinux is not recommended [2C]; after 3-6 months, LMWH or VKA continuation should be based on individual evaluation of the benefit-risk ratio, tolerability, patient preference and cancer activity [Guidance]. For the treatment of VTE recurrence in cancer patients under anticoagulation, three options can be considered: (i) switch from VKA to LMWH when treated with VKA; (ii) increase in LMWH dose when treated with LMWH, and (iii) VCF insertion [Guidance]. For the prophylaxis of postoperative VTE in surgical cancer patients, use of LMWH o.d. or low dose of UFH t.i.d. is recommended; pharmacological prophylaxis should be started 12-2 h preoperatively and continued for at least 7-10 days; there are no data allowing conclusion that one type of LMWH is superior to another [1A]; there is no evidence to support fondaparinux as an alternative to LMWH [2C]; use of the highest prophylactic dose of LMWH is recommended [1A]; extended prophylaxis (4 weeks) after major laparotomy may be indicated in cancer patients with a high risk of VTE and low risk of bleeding [2B]; the use of LMWH for VTE prevention in cancer patients undergoing laparoscopic surgery may be recommended as for laparotomy [Guidance]; mechanical methods are not recommended as monotherapy except when pharmacological methods are contraindicated [2C]. For the prophylaxis of VTE in hospitalized medical patients with cancer and reduced mobility, we recommend prophylaxis with LMWH, UFH or fondaparinux [1B]; for children and adults with acute lymphocytic leukemia treated with l-asparaginase, depending on local policy and patient characteristics, prophylaxis may be considered in some patients [Guidance]; in patients receiving chemotherapy, prophylaxis is not recommended routinely [1B]; primary pharmacological prophylaxis of VTE may be indicated in patients with locally advanced or metastatic pancreatic [1B] or lung [2B] cancer treated with chemotherapy and having a low risk of bleeding; in patients treated with thalidomide or lenalidomide combined with steroids and/or chemotherapy, VTE prophylaxis is recommended; in this setting, VKA at low or therapeutic doses, LMWH at prophylactic doses and low-dose aspirin have shown similar effects; however, the efficacy of these regimens remains unclear [2C]. Special situations include brain tumors, severe renal failure (CrCl<30 mL min(-1) ), thrombocytopenia and pregnancy. Guidances are provided in these contexts.

CONCLUSIONS

Dissemination and implementation of good clinical practice for the management of VTE, the second cause of death in cancer patients, is a major public health priority.

Inferior vena cava filters: a concise review

Venous thromboembolic disease is associated with significant morbidity and mortality. Anticoagulation has been the mainstay of treatment and prevention. Unfortunately, anticoagulation frequently fails or is contraindicated. Use of inferior vena cava filters can be an effective alternative in these scenarios. Though inferior vena cava filters have been used for > 4 decades, the evidence behind their use is limited. Use of IVC filters is associated with both minor and major complications. More randomized prospective trials are needed to evaluate these devices. In this article, we review issues concerning the use of inferior vena cava filters.

Lessons from French National Guidelines on the treatment of venous thrombosis and central venous catheter thrombosis in cancer patients

Increased prevalence of Venous thromboembolism (VTE), as defined by deep-vein thrombosis (DVT), central venous catheter (CVC) related thrombosis or pulmonary embolism (PE) in cancer patients has become a major therapeutic issue. Considering the epidemiology and each national recommendations on the treatment of VTE in cancer patients, we analysed guidelines implementation in clinical practice. Thrombosis is the second-leading cause of death in cancer patients and cancer is a major risk factor of VTE, due to activation of coagulation, use of long-term CVC, the thrombogenic effects of chemotherapy and anti-angiogenic drugs. Three pivotal trials (CANTHANOX, LITE and CLOT) and several meta-analysis led to recommend the long term (3 to 6 months) use of LMWH during for treating VTE in cancer patients with a high level of evidence. The Italian Association of Medical Oncology (AIOM), the National Comprehensive Cancer Network (NCCN), the American Society of Clinical Oncology (ASCO), the French "Institut National du Cancer" (INCa), the European Society of Medical Oncology (ESMO) and the American College of Chest Physicians (ACCCP) have published specific guidelines for health care providers regarding the prevention and treatment of cancer-associated VTE. Critical appraisal of these guidelines, difficulties in implementation of prophylaxis regimen, tolerance and cost effectiveness of long term use of LMWH may account for large heterogenity in daily clinical practice. Homogenization of these guidelines in international consensus using an adapted independent methodological approach followed by educational and active implementation strategies at each national level would be very valuable to improve the care of VTE in cancer patients.

Treatment of venous thromboembolism in patients with cancer: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

BACKGROUND

The treatment of venous thromboembolism (VTE) in cancer patients remains controversial.

PURPOSE

The Italian Society for Thrombosis and Haemostasis (SISET) commissioned a project to develop clinical practice guidelines for the therapy of VTE in patients with malignancies.

METHODS

Key questions about the treatment of VTE in patients with malignancies were formulated by a multidisciplinary working group consisting of experts in clinical medicine and research. After a systematic review and discussion of the literature, recommendations were formulated and graded according to the supporting evidence. For those questions for which the literature search did not yield any definitive answer (absence of evidence evidence of low quality, and contradictory evidence), a formal consensus method was used to issue clinical recommendations.

RESULTS

The results of the available literature on VTE treatment in cancer patients were reviewed and clinical recommendations were drafted.

CONCLUSION

We describe the results of a systematic literature review and an explicit approach to consensus techniques which resulted in recommendations for the key therapeutic issues in cancer patients with VTE.

Venous thrombotic emergencies

Thrombosis is a common complication of cancer, occurring in up to 15% of patients. This article reviews the diagnosis and management of the most common cancer-related thrombotic problem; deep venous thrombosis, pulmonary embolism, and catheterrelated thrombosis. Rarer entities, such as cerebral vein thrombosis and Budd-Chiari syndrome, are also reviewed.

[Venous thromboembolism and cancer]

OBJECTIVES

The risk of venous thrombosis during cancer is largely increased especially in case of chemotherapy, surgery, advanced stage disease, coagulation abnormalities. Survival of patients with cancer experiencing venous thrombosis seems to be worse. Although thrombosis may be a presenting feature of occult malignancy, there are insufficient data to support a more extensive screening than comprehensive medical history, physical examination, routine laboratory tests and chest radiography.

CURRENT KNOWLEDGE AND KEY POINTS

Pathophysiology of venous thrombosis during cancer is unspecific: venous stasis, vessel wall damage, hypercoagulability). Other factors like platelet abnormalities or the direct responsibility of chemotherapy or hormonotherapy have recently been though to play a causative role. Treatment of cancer-associated thrombosis usually requires at least 6 months of low-molecular-weight heparin therapy rather than oral anticoagulant. Inferior vena cava filters are not indicated. Primary prophylaxis of thrombosis during cancer could safely been achieved with low-molecular-weight heparin. Central venous catheters can be associated with thrombotic complications. Many risks factors have been identified: catheter's type, modalities of catheter's implantation, type of perfusion, bulky mediastinal mass... Prophylactic anticoagulation is not routinely recommended.

FUTURE PROSPECTS AND PROJECTS

Knew oral anticoagulants could facilitate the treatment of venous thrombosis occurring during cancer in the next years.

Vena Cava Filters: Uses and Abuses

Currently, there are more than 10 permanent and optional retrievable vena cava filters in use in North America and Europe. Indications for inferior vena cava (IVC) filter placement are intuitive and filters are used in patients who have deep venous thrombosis (DVT) and contraindications to anticoagulation, or in patients who hemorrhage while anticoagulated for DVT. Multiple studies have proposed broadening the use of IVC filters as primary venous thromboembolism (VTE) prophylaxis in certain patient populations. Many permanent IVC filters have been well studied and have superior performance characteristics. On the other hand, optional retrievable IVC filters are attractive in the patient with a well-defined, short-term risk for VTE and contraindications to anticoagulation. Filter retrieval after the patient can be anticoagulated would eliminate the long-term risk of DVT associated with permanent IVC filter placement. Unfortunately, most optional retrievable filters are relatively new and have little to no data on their long-term performance when used as permanent filters, and the percentage of retrievable filters actually removed is less than 50%. The spirited debate concerning which patient should get which filter is just beginning. More prospective, randomized trials evaluating optional retrievable filters are needed to answer these important questions.

Deep vein thrombosis and malignancy: a surgical oncologist's perspective

Oncology patients are at increased risk of developing deep vein thrombosis (DVT) and its potentially fatal sequel, pulmonary embolism. This is due to multiple factors, including the presence of the malignancy itself, comorbid factors and therapy-related interventions. Issues that are peculiar to venous thrombosis in the oncology setting are discussed, based on a MEDLINE search of the English literature. These include the need to screen for malignancy in idiopathic DVT, a high index of suspicion for venous thrombosis in the cancer patient, the use of vena cava filters, and the anti-neoplastic effects of heparin. Asian patients appear to have a lower incidence of DVT compared to Caucasians. A recommended regimen for prophylaxis of DVT must take into account the varying thrombosis risk associated with different malignancies. Cancer patients not undergoing abdominal, pelvic or orthopaedic surgery (e.g. mastectomy) should use elastic compression stockings and be mobilized early, whereas low-molecular-weight heparin should be given to those undergoing more major surgery. In advanced malignancy, treatment of DVT palliates symptoms. These patients may need long-term anticoagulation with warfarin.

Cancer and thrombosis: mechanisms and treatment

Standard venous thromboembolic event (VTE) treatment practices including the use of intravenous unfractionated heparin (UFH) for initial anticoagulation, oral warfarin for chronic anticoagulation, and the prescription of only 3 to 6 months total therapy may not be optimal in the setting of active cancer and ongoing anti-cancer therapy. Challenges of VTE management in cancer patients include heparin resistance due to excess circulating acute-phase proteins, increased recurrence rates during and following standard-intensity warfarin therapy, limited venous access to support therapeutic monitoring, and anticoagulation intensity-independent increased bleeding rates during anticoagulation. Bleeding during anticoagulation is of particular concern in the treatment of cancer patients with disease- or chemotherapy-related thrombocytopenia, central nervous system involvement, or recent invasive procedures. Low-molecular weight heparins (LMWH) have been shown to be at least as effective and safe for initial anticoagulation compared with UFH in persons with acute VTE and have gained popularity in the setting of VTE in cancer. LMWHs have the advantage of less non-specific protein binding, subcutaneous weight-based dosing without the need for monitoring in most cases, and probably less heparin-induced thrombocytopenia. Recent trials have demonstrated efficacy superiority of select LMWHs in place of oral warfarin for long-term anticoagulation in the cancer patient. The potential for anti-tumor effects and a survival advantage associated with select classes of anticoagulant agents is actively being investigated.

Extended Interval for Retrieval of Günther Tulip Filters

PURPOSE

To evaluate the Gunther Tulip vena cava filter with regard to ease of placement, complications, and retrieval over long time periods.

MATERIALS AND METHODS

In 53 patients (ratio of men to women, 24:29; mean age, 52.8 years) retrievable Gunther Tulip filters (Vena Cava M Reye Filter Set; William Cook Europe, Denmark) were inserted. Indications included planned major surgery with recent pulmonary embolus or high pulmonary embolus risk (n = 16), extensive ilio-femoral thrombus (n = 11), deep vein thrombosis with anticoagulant complications (n = 9), breakthrough pulmonary embolus despite anticoagulant therapy (n = 4), and contraindication to anticoagulant therapy (n = 13). All patients were followed-up for immediate and long-term complications.

RESULTS

Fifty-three filters were successfully placed in 52 of 53 patients, yielding a success rate of 98.1%. Nineteen patients underwent attempted retrieval of their filter. Sixteen of 19 retrieval procedures were successful (84%). In three patients, the filter could not be removed on attempted retrieval (extensive filter thrombus in two patients and attachment to the wall in one patient). One patient received two filters, which were both successfully retrieved at a later date. Median implantation time for retrievable filters was 34 days (range, 7-126 days). Mean follow-up for patients with permanent filters was 13 months. Two major complications (pneumothorax and break through pulmonary embolus) and three minor complications (right internal jugular vein thrombosis in two patients and transient Horner's Syndrome in one patient) were recorded.

CONCLUSION

Insertion and retrieval of filters is safe and feasible. Preliminary data suggest that Gunther Tulip filter retrieval is feasible over and above the manufacturer's recommended retrieval interval of 14 days.

The Role of Vena Caval Filters in the Management of Venous Thromboembolism

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are important, and not infrequent, causes of morbidity and mortality in critically ill patients. Anticoagulation remains the treatment of choice for DVT and PE, but contraindications to, and complications from, anticoagulant therapy mandate the availability of alternate therapeutic and prophylactic strategies. The recent availability of safe and effective vena caval filters that can be inserted via a minimally invasive percutaneous approach has expanded the indications for, and acceptance of, these devices in selected patients at high risk for the development of PE. This article reviews both the established and the evolving indications for vena caval filters and discusses how improvements in filter design may impact future use.

Factors associated with recurrent venous thromboembolism in patients with malignant disease

PURPOSE

The role of prophylactic vena cava filters (VCF) in patients with cancer is debated. Although VCF are often placed in patients with cancer after recurrence of venous thromboembolic events (VTE), identification of this subset of patients has not been well-defined. This study was undertaken to assess factors associated with increased risk for recurrent VTE.

METHODS

All patients with a history of thromboembolism or malignant disease and who required a VCF because of failure of or contraindication to anticoagulation therapy were abstracted from the Michigan Filter Registry. Univariate analysis of potential risk factors for recurrent VTE and logistic regression models were used to identify associations between these variables and recurrent VTE.

RESULTS

Ninety-nine patients (49 men, 50 women) with a mean age of 58 years were included in the study. New metastases occurred in 55% of patients, and 12% of patients had a history of VTE before cancer diagnosis. Corticosteroid agents were used during therapy in 48% of patients. Acute VTE was present in 52% of patients at cancer diagnosis, and in 34% of patients VTE was associated with new metastases. Recurrent VTE occurred in 40% of patients, and significant risk factors included presence of new metastases (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.16-9.09; P =.02) and history of VTE (OR, 10.6; CI, 1.98-57.2; P =.006). Whereas a single episode of neutropenia did not reach significance (OR, 1.1; CI, 0.97-1.35; P =.11), multiple neutropenic episodes were significantly associated with recurrent VTE (P =.04). Smoking, hormone replacement therapy, decreased mobility, post-surgical state, and obesity were not independently associated with increased risk. Mean survival in this series was 30 months, and was significantly worse in patients with VTE at cancer diagnosis and with inability to tolerate anticoagulant therapy in conjunction with VCF.

CONCLUSION

Patients with malignant disease may be at increased risk for recurrent VTE after development of new metastases or multiple episodes of neutropenia, especially those patients with a history of VTE. VCF may be a reasonable alternative to long-term anticoagulation therapy in this subgroup of patients at high risk patients, provided their quality of life is reasonable.

Proximal extent of pelvic vein thrombosis and its association with pulmonary embolism

OBJECTIVE

Conventional methods such as duplex ultrasound scanning do not provide accurate information about proximal extension of pelvic vein thrombosis. We evaluated proximal extent of thrombus toward pelvic veins with magnetic resonance imaging in patients with suspected deep vein thrombosis (DVT) proximal to the inguinal ligament on the basis of duplex ultrasound scans. In addition, frequency of pulmonary embolism (PE) and early (4 weeks) clinical outcome were evaluated.

METHODS

Two hundred twelve patients with acute symptomatic DVT proximal to the inguinal ligament, diagnosed at duplex ultrasound scanning, were enrolled in this prospective study. All patients underwent magnetic resonance imaging of the abdominal and pelvic veins, as well as lung scintigraphy to detect the presence of pulmonary embolism.

RESULTS

In 24 of 212 patients (11%), thrombus was restricted to the femoral vein. The thrombus extended into iliac veins in 142 patients (67%) and into the inferior vena cava in 46 patients (22%). The frequency of PE was not associated with the most proximal extension of thrombus (P =.61). No patients died as a consequence of thromboembolic events.

CONCLUSIONS

Extension of DVT into the inferior vena cava occurs relatively frequently. In our patients this finding was not associated with higher risk for PE compared with DVT of the femoral or iliac veins.

Thromboembolic complications of cancer: epidemiology, pathogenesis, diagnosis, and treatment

The association between malignancy and clinical thrombosis has been recognized for nearly 140 years. The purpose of this review is to examine our current understanding of thrombosis as a complication of cancer and cancer therapy. The review includes a discussion of the epidemiology, pathophysiology, diagnosis and treatment.

Thromboembolic disease and cancer: possible new treatments

Hypoxia-induced endothelin (ET) and vascular endothelial growth or permeability factor (VEGF) play an important role in tumor biology by promoting angiogenesis. Angiogenesis alters hemostasis and promotes thromboembolic disease (TED). Therapeutic angiogenesis directed against ET and VEGF may reduce the incidence of TED in cancer patients.

Anticoagulation therapy

Despite refinements and standardization in the use of anticoagulants, many problems remain for clinicians. Dr. Crowther describes appropriate starting and maintenance doses of warfarin, factors accounting for inter- and intra-observer variability and importantly, the management of the over-anticoagulated patients and bleeding patients. Dr. White compares unfractionated heparin (UFH) and low molecular weight heparin (LMWH) and addresses whether there truly are differences in the efficacy and safety of different LMWH's for both arterial and venous indications. Dr. Ortel discusses the management of the problem patient who requires anticoagulants, the management of heparin-induced thrombocytopenia, the pregnant patient, the obese patient, patients who have renal insufficiency and/or liver disease, patients with malignant disease, and other challenging patient populations.

The clinical course of deep vein thrombosis in patients with gynecologic cancer

OBJECTIVE

The aim of this study was to evaluate the survival of gynecologic cancer patients diagnosed with deep vein thrombosis.

METHODS

We retrospectively reviewed the charts of patients admitted to our institution with gynecologic malignancy who were diagnosed with deep vein thrombosis (DVT) between 1984 and 1995. Data were collected regarding site, stage, histology, treatment, and proximity of DVT to treatment with surgery, chemotherapy, and radiotherapy. This study was limited to cases of ovarian, uterine, and cervical cancer. Descriptive statistics were generated and the survival of patients from the time of DVT was calculated using the Kaplan and Meier method. Cases were then matched by site, stage, histology, and age to controls without DVT to evaluate the effect of DVT on survival. A Cox regression model was used to assess the effect of multiple variables on survival.

RESULTS

A total of 74 cases were identified. Ovarian, uterine, and cervical cancer accounted for 45, 27, and 28% of cases, respectively. Approximately 64% of patients had stage III or greater disease. The median survival of all patients from the time of DVT diagnosis was 7.8 months, with only about 20% of patients surviving at 5 years. Patients with cervical cancer or patients who had radiation therapy within 3 months of DVT diagnosis had significantly lessened survival (P < 0.01) than other patients with DVT. The survival of patients from the time of cancer diagnosis with venous thrombosis was significantly worse than a matched control group without DVT (P < 0.001). On multivariate analysis, there was a twofold greater risk of dying in those patients with gynecologic cancer and DVT.

CONCLUSION

The development of DVT in conjunction with a gynecologic malignancy connotes a poor prognosis, especially in patients with cervical cancer. It is possible that this poor prognosis is related to the pathophysiology that results in venous thrombosis and not just the presence of cancer.

Bleeding and thrombotic complications in critically ill patients with cancer

Alterations in hemostasis are common in patients with cancer admitted to the ICU. Depending on the underlying disease and specific hemostatic abnormality, the patient with cancer may develop bleeding, thrombosis, or both, such as DIC. Bleeding complications usually result from abnormalities in platelets or deficiency of coagulation factors and require specific blood or coagulation factor replacement. Similarly, critically ill patients with cancer are predisposed to thrombotic complications such as DVT, PE, and central vein thrombosis, the last as a result of the widespread use of long-term indwelling catheter devices. Advances in diagnostic imaging and the availability of newer and more potent anticoagulant agents have facilitated the care of these patients greatly. Ultimately, it is hoped that a thorough understanding of the various disturbances in hemostasis, innovative treatment approaches, and implementation of preventive strategies in patients with cancer will lead to decreased morbidity and improved survival rates of critically ill patients with cancer in the ICU.

Heparin-induced Thrombocytopenia

Treatment with heparin is associated with two types of thrombocytopenia. The most worrisome of these is the immune-mediated heparin-induced thrombocytopenia (HIT type II). Suspicion of HIT type II mandates immediate cessation of heparin administration and consideration of an alternative anticoagulation therapy. Hirudin and argatroban are approved alternative anticoagulants with no cross-reactivity with the HIT antibody. HIT type II is a clinicopathologic syndrome, and therefore diagnosis requires clinical and laboratory confirmation. The laboratory evaluation for HIT type II should also determine whether or not there is HIT-antibody cross-reactivity with danaparoid and low molecular weight heparin. Patients with HIT type II who require coronary artery bypass graft surgery present a particularly difficult situation, as there is no ideal alternative to heparin anticoagulation.

Interventional radiology in the gynaecological oncology patient

The use of radiologically guided percutaneous procedures has greatly reduced the morbidity and mortality of gynaecological oncology patients. Certain procedures, previously requiring major surgery, can now be performed with little patient discomfort, with conscious sedation instead of general anaesthesia, and frequently on an outpatient basis. In this chapter, diagnostic and therapeutic arteriography and venography will be discussed as well as radiologically guided genitourinary interventions. This represents an overview of what is available to the gynaecologist from the interventional radiologist in his/her practice.

Acquired thrombophilic syndromes

As the biochemical mechanisms of hypercoagulable states are revealed, the syndromes of venous thromboembolism have been increasingly associated with specific aberrations. Most of these changes involve an increase in procoagulant potential, for example, by activation of the coagulation cascade, or by a defect or decrease in natural inhibitors of clotting. Similar abnormalities of the fibrinolytic pathways may contribute, as can loss of inhibitory mechanisms of endothelial cells, as well as changes in vascular anatomy and rheologic patterns of blood flow. All of these factors can directly influence thrombus formation and/or the physiologic response to the thrombus.(1)

Cancer, thrombosis, and anticoagulants

Rapid progress has been made recently in our understanding of the pathogenesis of coagulation activation in malignancy and mechanisms by which the coagulation mechanism may control malignant growth. Idiopathic thromboembolic disease may be the sentinel presentation in patients subsequently diagnosed with malignancy. Thrombosis complicating the course of malignancy may be notoriously difficult to treat, but the introduction of the low-molecular-weight heparins has greatly improved management and may obviate the need for invasive approaches, such as the use of inferior vena cava filters, in many cases. Tantalizing clues from clinical trials of anticoagulant therapy in cancer have suggested that components of coagulation pathways may support tumor growth. Many of these can be intercepted using drugs that are well known and non-toxic. The importance of performing high-quality controlled clinical trials that build on past studies and on data from basic research cannot be overemphasized.