Use of the Greenfield filter for thromboembolic disease in pregnancy

Inferior vena cava filters in pregnancy: Safe or sorry?

Background

Potential hazards of vena cava filters include migration, tilt, perforation, fracture, and in-filter thrombosis. Due to physiological changes during pregnancy, the incidence of these complications might be different in pregnant women.

Aim

To evaluate the use and safety of inferior vena cava filters in both women who had an inferior vena cava filter inserted during pregnancy, and in women who became pregnant with an inferior vena cava filter in situ.

Methods

We performed two searches in the literature using the keywords “vena cava filter”, “pregnancy” and “obstetrics”.

Results

The literature search on women who had a filter inserted during pregnancy yielded 11 articles compiling data on 199 women. At least one filter complication was reported in 33/177 (19%) women and included in-filter thrombosis (n = 14), tilt (n = 6), migration (n = 5), perforation (n = 2), fracture (n = 3), misplacement (n = 1), air embolism (n = 1) and allergic reaction (n = 1). Two (1%) filter complications led to maternal deaths, of which at least one was directly associated with a filter insertion. Filter retrieval failed in 9/149 (6%) women. The search on women who became pregnant with a filter in situ resulted in data on 21 pregnancies in 14 women, of which one (6%) was complicated by uterine trauma, intraperitoneal hemorrhage and fetal death caused by perforation of the inferior vena cava filter.

Conclusion

The risks of filter complications in pregnancy are comparable to the nonpregnant population, but could lead to fetal or maternal death. Therefore, only in limited situations such as extensive thrombosis with a contraindication for anticoagulants, inferior vena filters should be considered in pregnant women.

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.

Experience with Greenfield Filters in Pregnant Women for Deep Venous Thrombosis and Pulmonary Embolism Case Reports

The indications for inferior vena caval filter placement in the gravid female are ill defined. During pregnancy, however, pulmonary embolism (PE) secondary to venous thrombosis is the most common cause of maternal mortality. Pregnant women are at risk for deep venous thrombosis (DVT) due to hypercoagulability caused by increased levels of coagulation factors and decreased fibrinolytic activity. In addition, decreased venous tone and velocity of blood flow in the lower extremities lead to venous stasis. Although heparin is the treatment of choice for DVT associated with pregnancy, propagation of thrombus or development of bleeding diathesis mandates discontinuation of anticoagulant therapy and consideration for caval interruption. In this review, two patients are presented who required vena caval filters during pregnancy, and indications for their usage in this patient population are defined. Filter placement is recommended during pregnancy in the presence of extensive iliofemoral thrombus, free-floating thrombus, bleeding complications, or pulmonary embolism despite adequate anticoagulation.

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.

Use of a temporary inferior vena cava filter during pregnancy in patients with thromboembolic events

There are circumstances in the management of thromboembolic events during pregnancy when anticoagulant therapy is either contraindicated or not advisable, such as when pulmonary embolism (PE) or deep venous thrombosis is diagnosed close to term, given the risk of bleeding during delivery. In these cases, the thromboembolic risk can be controlled using temporary inferior vena cava filters (T-IVCFs). We present the case of a pregnant woman with thrombophilia who remained at rest for eight weeks due to an amniotic prolapse and for whom the placement of a T-IVCF was decided at 32 weeks' gestation after anticoagulant therapy had failed. An emergency caesarean section was performed at 33 weeks' gestation due to placental abruption following the spontaneous onset of preterm labour. The risk of bleeding during delivery when high doses of heparin are used, and the risk of PE when the heparin dose is decreased, needs to be evaluated versus the risks related to T-IVCF placement procedure and, as such, a review of the published experience in this field is warranted. We have concluded that T-IVCFs can be a safe alternative treatment for pregnant women in whom anticoagulation therapy is either contraindicated or not advisable.

Emergent surgical pulmonary embolectomy in a pregnant woman: case report and literature review

Acute pulmonary embolism is a leading cause of death during pregnancy and delivery in the United States. We describe the case of a 25-year-old woman who presented in cardiogenic shock in week 38 of her first pregnancy. After the emergent cesarean delivery of a healthy male neonate, the mother underwent immediate surgical pulmonary embolectomy. We confirmed the diagnosis of pulmonary embolism intraoperatively by means of transesophageal echocardiography and removed large clots from the patient's pulmonary arteries. Mother and child were doing well, 27 months later. In addition to presenting our patient's case, we discuss the other relevant reports and the options for treating massive pulmonary embolism during pregnancy.

Endovascular caval interruption in pregnant patients with deep vein thrombosis of the lower extremity

PURPOSE

The choice of therapy for deep vein thrombosis (DVT) of the lower extremity during pregnancy has been widely debated. Warfarin passes through the placenta to the fetus and may cause fetal complications and/or death. Heparin, in contrast, does not cross the placenta, but its long-term use may be impractical and may increase the risk of bleeding, osteoporosis, and neurologic complications. The use of inferior vena cava filters in pregnancy has only been described as case reports in the English medical literature; therefore, this study reviews our experience on this subject.

METHODS

We analyzed 18 pregnant patients who had Greenfield filters (GFs) inserted for DVT of the lower extremity, pulmonary embolism (PE), or both. The DVT diagnosis was made by means of duplex imaging. Conventional full-dose intravenous heparin was initiated until the filter was inserted, followed by subcutaneous heparin until labor, and continued for 6 weeks postpartum in 13 patients who were breast-feeding. Warfarin was given postpartum in the other five patients.

RESULTS

The mean age of the patients was 25 years. The indications for GF insertion included 3 patients who had a PE while on anticoagulation, 2 patients with significant bleeding caused by anticoagulation, 4 patients with free-floating iliofemoral DVT, 2 patients with heparin-induced thrombocytopenia, and 7 patients with iliofemoropopliteal DVT occurring 1 to 3 weeks before labor, for prophylactic reasons. Fourteen of 18 cases were diagnosed in the third trimester of the patient's pregnancy. Filters were inserted via the right internal jugular vein by means of a cut-down technique in the first four patients (stainless steel filters) and percutaneously in 14 patients. The mean fluoroscopy time during filter insertion was less than 2 minutes. There was no fetal or maternal morbidity or mortality. During long-term follow-up (mean, 78 months), no PE or filter-related complications were encountered.

CONCLUSION

GF insertion in pregnant patients with DVT of the lower extremity is safe and effective. Its prophylactic use in pregnant patients who have extensive iliofemoral DVT right before labor may be justified.

Vena caval filters: a comprehensive review

Hematologists are often asked to treat patients with venous thromboembolic disease. Although anticoagulation remains the primary therapy for venous thromboembolism, vena caval filters are an important alternative when anticoagulants are contraindicated. To assess the evidence supporting the utility of these devices, a comprehensive review of the English language literature was performed. Except for one randomized trial, the vena caval filter literature consists of case series or consecutive case series. The mean duration of follow-up for each of the 5 filter types varies from 6 to 18 months. All are about equally effective in the prevention of pulmonary embolism (2.6%-3.8%). Deep venous thrombosis (6%-32%) and inferior vena cava thrombosis (3.6%-11.2%) after filter placement vary widely among different filter types primarily because of differences in outcome assessment. Thrombosis at the insertion site is a common complication of filter placement (23%-36%). In view of the absence of randomized comparisons, no filter can be designated as superior in safety or efficacy. Vena caval filters represent a potentially important but poorly evaluated therapeutic modality in the prevention of pulmonary emboli. Randomized trials are necessary to establish the appropriate place for vena caval filters in the treatment of venous thromboembolic disease.

Vena caval filters: a comprehensive review

Hematologists are often asked to treat patients with venous thromboembolic disease. Although anticoagulation remains the primary therapy for venous thromboembolism, vena caval filters are an important alternative when anticoagulants are contraindicated. To assess the evidence supporting the utility of these devices, a comprehensive review of the English language literature was performed. Except for one randomized trial, the vena caval filter literature consists of case series or consecutive case series. The mean duration of follow-up for each of the 5 filter types varies from 6 to 18 months. All are about equally effective in the prevention of pulmonary embolism (2.6%-3.8%). Deep venous thrombosis (6%-32%) and inferior vena cava thrombosis (3.6%-11.2%) after filter placement vary widely among different filter types primarily because of differences in outcome assessment. Thrombosis at the insertion site is a common complication of filter placement (23%-36%). In view of the absence of randomized comparisons, no filter can be designated as superior in safety or efficacy. Vena caval filters represent a potentially important but poorly evaluated therapeutic modality in the prevention of pulmonary emboli. Randomized trials are necessary to establish the appropriate place for vena caval filters in the treatment of venous thromboembolic disease.

Use of thrombolytics for the treatment of thromboembolic disease during pregnancy

The incidence of thromboembolic disease is increased during pregnancy. Prevention and treatment of thromboembolic disease can have a significant impact on the morbidity and mortality of pregnant women. Anticoagulation with heparin is the treatment of choice; however, in some instances this is inadequate or contraindicated. In the nonpregnant patient, alternative therapies have included surgical intervention or fibrinolytic agents. Traditionally, thrombolytic therapy has been considered a relative contraindication during pregnancy due to the maternal and fetal risk of hemorrhagic complications. Hence, no controlled trials of agents such as streptokinase, urokinase, or tissue plasminogen activator for the treatment of thromboembolic events during pregnancy, have been performed, or are currently feasible. Since 1961, 36 reports have been published describing the use of thrombolytic agents during pregnancy. In a review of the world's literature, 172 pregnant women affected with thromboembolic conditions were treated with thrombolytic medications. A maternal mortality rate of 1.2 percent was observed. Approximately 10 pregnancy losses were noted (5.8 percent). Hemorrhagic complications were reported in 8.1 percent of patients. We summarize the published literature on the use of thrombolytic agents during pregnancy and discuss the treatment success and reported complications.

Utilization patterns with inferior vena cava filters: surgical versus percutaneous placement

PURPOSE

To determine whether more inferior vena cava (IVC) filters were used after interventional radiologic placement methods became available, and if so, whether this increase could be due to expansion of indications.

PATIENTS AND METHODS

A retrospective analysis of the number of filters placed, the method of placement used, the indications for placement, and patient survival was performed during the 3 years before and the 3 years after 1989, the first year filters were placed percutaneously at the authors' institution.

RESULTS

From 1986 through 1988, 35 filters were all placed by surgeons in the operating room. From 1990 through 1992, 201 filters were all placed by radiologists in the special procedures suite. In the surgery group, 13 of 35 filters (37%) were placed for contraindications to anticoagulation therapy, 12 (34%) were placed for complications of anticoagulation, and nine (26%) were placed for recurrent thromboembolic disease despite anticoagulation. One filter was placed because of a free-floating thrombus in the IVC. In the radiology group, 98 of 161 patients (60%) underwent placement for contraindications to anticoagulation, 25 (16%) experienced complications of anticoagulation, 28 (17%) experienced recurrent thromboembolic disease, and nine (6%) had a free-floating thrombus. The 6-month survival in patients treated before 1989 was 80% versus 43% after 1989.

CONCLUSION

At the authors' institution, filters are now placed exclusively by interventional radiologists. The overall indications for placement remain unchanged. The increase in utilization appears primarily related to more frequent placement in severely ill patients who may not experience considerably improved survival but may benefit from a substantial reduction in the risk of hemorrhagic complications.

Experience with the Cardial inferior vena cava filter as prophylaxis against pulmonary embolism in pregnant women with extensive deep venous thrombosis

OBJECTIVE

To report the use of the Cardial inferior vena caval filter as prophylaxis against pulmonary embolism in pregnant women with extensive iliofemoral thrombosis.

SETTING

Leicester Royal Infirmary.

SUBJECTS

Four pregnant women with extensive iliofemoral thrombosis, deemed to be at high risk of pulmonary embolism, managed over a period of one year.

TECHNIQUE

In addition to standard full anticoagulation with heparin, the Cardial inferior vena cava filter was introduced percutaneously under local anaesthesia through the unaffected contralateral femoral vein and positioned in the inferior cava below the renal veins.

RESULTS

The procedure was uncomplicated and did not compromise feto-maternal condition. There was no evidence of pulmonary embolism after filter insertion.

CONCLUSION

The use of inferior vena cava filters should be considered as an adjunct to intravenous anticoagulation in pregnant women with extensive deep vein thrombosis of the lower limbs.