Short-term prophylaxis of pulmonary embolism by using a retrievable vena cava filter

Complications related to deep venous thrombosis prophylaxis in trauma: a systematic review of the literature

Deep venous thrombosis prophylaxis is essential to the appropriate management of multisystem trauma patients. Without thromboprophylaxis, the rate of venous thrombosis and subsequent pulmonary embolism is substantial. Three prophylactic modalities are common: pharmacologic anticoagulation, mechanical compression devices, and inferior vena cava filtration. A systematic review was completed using PRISMA guidelines to evaluate the potential complications of DVT prophylactic options. Level one evidence currently supports the use of low molecular weight heparins for thromboprophylaxis in the trauma patient. Unfortunately, multiple techniques are not infrequently required for complex multisystem trauma patients. Each modality has potential complications. The risks of heparin include bleeding and heparin induced thrombocytopenia. Mechanical compression devices can result in local soft tissue injury, bleeding and patient non-compliance. Inferior vena cava filters migrate, cause inferior vena cava occlusion, and penetrate the vessel wall. While the use of these techniques can be life saving, they must be appropriately utilized.

Outcomes with retrievable inferior vena cava filters: a multicenter study

PURPOSE

To retrospectively review the outcomes after placement and retrieval of retrievable inferior vena cava (IVC) filters at two academic medical centers.

MATERIALS AND METHODS

All patients who underwent retrievable filter placement between May 2001 and December 2005 were included. Hospital records at both institutions were reviewed, and relevant data were collected concerning the placement and retrieval of all removable filters.

RESULTS

A total of 197 patients underwent placement of a retrievable IVC filter. Of those, 143 patients (72.5%) had Günther Tulip filters (GTFs) placed, and 54 patients (27.5%) had Recovery filters placed. A total of 94 patients underwent attempted filter retrieval, accounting for just less than half of all retrievable filters placed during the study period (47.7%). Retrievals were successful in 80 patients (85.1%). Half the retrieval failures (n = 7) were the result of thrombus within the filter, and technical difficulties (eg, filter embedded in IVC wall, tilted filter) were the cause of retrieval failure in the other half. There was no significant difference in retrieval failure rates between the GTF and Recovery filter (16.4% vs 9.5%, respectively). GTFs were removed after a median implantation time of 11 days (range, 1-139 d), whereas Recovery filters were removed after a median implantation time of 28 days (range, 6-117 d).

CONCLUSIONS

Placement and retrieval of nonpermanent IVC filters can be performed safely with a high technical success rate. In patients at high risk for venous thromboembolism and contraindication to anticoagulation, retrievable filters may be used aggressively to prevent the potentially devastating outcome of pulmonary embolism.

Optional vena cava filters for patients with high thromboembolic risk: questions to be answered

The use of vena cava filters has increased rapidly over the past few years to more than 140,000 filters inserted worldwide in 2003. Continued improvements in filter design have increased the safety of intravascular caval filtration. Although there are many factors attributed to this increase, the most significant contributing factor has been the development of optional vena cava filters. That is, filters that can be left as a permanent device or can be removed endovascularly at a later date. Three filters are approved for removal in the United States, the Günther Tulip, the OptEase, and the Recovery. Recent reports have demonstrated the safety and feasibility of these devices in appropriate patients, but a number of questions have arisen regarding their use.

Clinical experience with retrievable vena cava filters: results of a prospective observational multicenter study

BACKGROUND

Retrievable inferior vena cava (IVC) filters offer the attractive possibility to be definitive or to be removed when they become unnecessary.

OBJECTIVE

The purpose of this study was to evaluate the efficacy and the likelihood to remove the retrievable IVC filter ALN.

METHODS

A total of 30 patients (13 males and 17 females, mean age 57 +/- 15 years) underwent placement of ALN filters. Indications for implantation were acute venous thromboembolism (VTE) with a contraindication to anticoagulation in 26 cases (86%), primary prophylaxis after major trauma in two cases (7%) or before surgery in two patients with very high thromboembolic risk (7%).

RESULTS

The filter was successfully placed in all patients. After a median follow-up of 18.2 months, there were three cases (10%) of trapped emboli within the filter, one case (3%) of asymptomatic migration of the filter toward the heart and two patients (7%) had deep vein thrombosis (DVT) recurrences. ALN retrieval was attempted through transjugular approach in 18 patients (60%) and the maneuver was successful in 14 of them (78%); when the decision of removal was taken more than 3 months after the implantation, the retrieval was possible only in four of eight patients (50%). The median implantation period was 123 days (range: 30-345).

CONCLUSIONS

The present study shows the efficacy of ALN filter; it also demonstrates the feasibility and safety of retrieval after a medium-term period of placement. Removal after 3 months after implantation can be unsuccessful and maximum implantation time requires further studies.

Retrievable vena cava filters in trauma patients for high-risk prophylaxis and prevention of pulmonary embolism

BACKGROUND

Venous thromboembolic (VTE) disease remains a significant cause of morbidity for trauma patients because many patients have injuries that may preclude effective VTE prevention and treatment. Retrievable vena cava filters may prove beneficial in this subset of trauma patients.

METHODS

Trauma patients at risk for VTE were identified and managed by institutional protocol. Patients who required a vena cava filter were managed with a device that could be retrieved or left in situ. A retrospective review of medical records was used to identify the use, indications, and complications associated with a retrievable filter.

RESULTS

Fifty-three retrievable filters were placed in 51 patients. Two of these patients received a second filter, and 1 received a filter in the superior vena cava. Thirty-two filters were placed prophylactically, whereas 21 were placed for demonstrated venous thromboembolism (VTE). Retrieval was successful in 24 of 25 attempts. Twenty-nine filters became permanent: 10 for continued contraindications to anticoagulation without known VTE, 12 for known VTE and continued contraindications to anticoagulation, 1 for technical reasons, and 6 because of patient death. There were no complications of bleeding, device migration or thrombosis, infection, or pulmonary embolism.

CONCLUSIONS

A retrievable vena cava filter appears safe and effective for the prevention of pulmonary embolism in the high-risk trauma patient who cannot receive anticoagulation.

Removal of Vena Caval Filter at 224 Days

Patients at risk of pulmonary embolism usually receive anticoagulants, which are contraindicated in trauma victims. A woman with extensive deep venous thrombosis after a vehicle accident had a nitinol Recovery Filter inserted prophylactically. After her recovery, she requested filter removal because of her intention to become pregnant. The filter was removed percutaneously without difficulty 224 days after implantation.

Removal of Günther Tulip Vena Cava Filter through Femoral Vein Approach

The Günther Tulip vena cava filter is designed for removal by the internal jugular vein approach with use of a blunted hook placed at the superior aspect of the filter. Removal of this filter was performed by the femoral approach in a patient with central venous occlusion that precluded removal by the conventional approach.

A new optional vena cava filter: retrieval at 12 weeks in an animal model

PURPOSE

To test the feasibility and safety of percutaneous retrieval of a new inferior vena cava (IVC) filter, the Recovery Filter (RF), acutely and after 12-week implantation in sheep.

MATERIALS AND METHODS

The RF is a bilevel filter with stabilizing arms and elastic hooks that allow retrieval with a unique retrieval cone after incorporation into the wall of the IVC. Twenty-four filters were placed in the infrarenal IVCs of 18 sheep. In six sheep, two filters were placed and then removed immediately; three sheep were killed acutely and three were killed after a healing period of 3 weeks. In 12 sheep, a single filter was placed and then removed 12 weeks later; six were killed after retrieval and six were killed after an 8-week healing period.

RESULTS

The mean (+/-SD) transverse vena caval diameter was 15.3 mm +/- 2. All filters were deployed as intended and retrieved without difficulty. At sacrifice, there was no evidence of IVC perforation or retroperitoneal abnormality. The IVCs of the animals in the acute retrieval group showed minimal acute superficial injury that was largely reversed at 3 weeks. At 12 weeks, there was evidence of transmural incorporation of filter elements with narrowing of the IVCs. Solitary fibrotic abnormalities were present in the aorta adjacent to IVC lesions in nine of the 12 animals in the 12-week group. The IVC and aortic abnormalities were largely healed, with reversal of IVC narrowing after 8 weeks.

CONCLUSION

The recovery filter can be reliably and safely retrieved acutely and 12 weeks after implantation in sheep.

Initial experience in humans with a new retrievable inferior vena cava filter

PURPOSE

To evaluate preliminary clinical experience in humans with the Recovery nitinol filter (RNF) for the inferior vena cava, especially the efficacy of the device and safety of its retrieval.

MATERIALS AND METHODS

Thirty-two patients were followed up to assess for filter efficacy and for ability to remove the filter.

RESULTS

Sixteen men and 16 women aged 18-83 years (mean, 53 years) underwent treatment with the RNF. Indications for placement were recent pulmonary embolism (n = 16), recent deep venous thrombosis (n = 20), and/or prophylaxis (n = 2). Four patients had contraindications to anticoagulant therapy, and four had complications from anticoagulant therapy. The filter was successfully placed in 32 patients. In 24 (100%) of 24 patients, the filter was successfully retrieved with a jugular approach. The mean implantation period was 53 days (range, 5-134 days). Trapped thrombus was seen within the filter in seven cases. In one patient with a large trapped thrombus, the filter was noted to have migrated 4 cm cephalad. There were no episodes of pulmonary embolism or insertion-site thrombosis.

CONCLUSION

This preliminary experience in humans confirms the efficacy of the RNF. It also demonstrates the feasibility and safety of retrieval up to 134 days after implantation.

Günther Tulip Retrievable Vena Cava Filter: results from the Registry of the Canadian Interventional Radiology Association

PURPOSE

To report data collected by the Canadian Registry of the Günther Tulip Retrievable Filter (GTF).

MATERIALS AND METHODS

Between February 1998 and December 2000, 90 patients at eight hospitals underwent implantation of 91 GTFs. There were 45 male patients and 45 female patients, age 17-88 years, with a mean age of 49 years. Indications for filter placement were pulmonary embolism (PE) or deep vein thrombosis (DVT) with a contraindication to anticoagulation in 83 patients, prophylaxis after massive PE in one, prophylaxis for proximal free-floating thrombus in one, and prophylaxis with no DVT or PE in six patients (major trauma, n = 4; high preoperative risk, n = 2). GTF retrieval was attempted in selected patients from a right internal jugular vein approach.

RESULTS

One GTF was inadvertently placed in the right iliac vein and could not be retrieved. There were no other major placement complications. GTF retrieval was attempted in 52 patients (53 GTFs); 52 GTFs were successfully retrieved from 51 patients. Implantation times were 2-25 days (mean, 9 d). Of these 51 patients, 37 underwent follow-up for 5-420 days (mean, 103 d) after filter retrieval. Four patients (8% of retrieved GTFs) required reinsertion of a permanent filter 17-167 days (mean, 78 d) after GTF retrieval as a result of bleeding from anticoagulation (n = 2) or because the patient required further surgery (n = 2). One other patient had recurrent DVT 230 days after retrieval; no PE or other complication was documented in the retrieval group. GTFs were not retrieved from 39 patients for various reasons. Of these 39 patients, 25 underwent follow-up 7-420 days (mean, 85 d) after filter placement. Two patients developed filter occlusion (5%); no other complications were documented.

CONCLUSION

The GTF has a broad range of utility: it can be used as a permanent filter or retrieved after implantation periods of 15 days and possibly longer. However, indications for retrieval require further study, as does the maximum implantation time.

Retrievable IVC filter: preliminary in vitro and in vivo evaluation

PURPOSE

To develop an inferior vena cava (IVC) filter that is retrievable even after neointimal formation and incorporation into the caval wall.

MATERIALS AND METHODS

Eight filters were placed percutaneously in the infrarenal IVC of eight dogs. Four weeks after placement, percutaneous retrieval of the filters was attempted. Vena cavograms were obtained before and immediately after retrieval. Three dogs were killed immediately after the retrieval procedure was completed. In the other five dogs, follow-up vena cavography was performed 4-14 weeks after retrieval, and autopsy was performed.

RESULTS

The filters were placed and retrieved successfully in all eight dogs. No migration, caval penetration, or tilting occurred. The IVCs were completely patent both before and immediately after retrieval in all eight dogs. In the three dogs killed immediately after retrieval, neointimal hyperplasia was seen around the struts, but there was no detachment. Delayed stenosis was not seen in any of the five dogs that were followed up, and the inner surface of the caval wall was smooth.

CONCLUSION

This IVC filter can be easily placed and safely retrieved percutaneously, even after neointimal formation.