Successful Retrieval of 29 ALN Inferior Vena Cava Filters at a Mean of 25.6 Months after Placement

Numerical simulation and in vitro experimental study of thrombus capture efficiency of a new retrievable vena cava filter

The vena cava filter is a filtering device to prevent pulmonary embolism caused by thrombosis from lower limbs and pelvis. A new retrievable vena cava filter was evaluated in this paper. To evaluate the hemodynamic performance and thrombus capture efficiency after transplantation, numerical simulation of computational fluid dynamics was performed. In this paper, the two-phase flow model of computational fluid dynamics software was used to analyze the outlet blood flow velocity, inlet-outlet pressure difference, filter wall shear stress, the ratio of area with wall shear stress, and the thrombus capture efficiency with the thrombus diameter of 5 mm, 10 mm, 15 mm and the thrombus content of 10%, 20%, 30%, respectively. Additionally, in vitro experimental test was performed to compare its thrombus capture efficiency with Denali and Aegisy Filters. The Denali Filter showed the least interference with the blood flow, followed by the new filter and the Aegisy Filter. The results indicated that the new filter had a higher capture rate in capturing 5mm small-diameter thrombus. This research certain theoretical significance and reference value for the research and development of the new vena cava filters as well as the evaluation of the thrombus capture efficiency of the filters.

Pathological Analysis and Clinical Evolution After Radiological Removal of Retrievable Vena Cava Filters

Objective

Retrievable inferior vena cava filters (IVCF) have been developed because permanent filters have been associated with an increased risk of recurrent deep venous thrombosis. There is no data on the interactions of IVCF with the inferior vena cava (intrafilter thrombi, insertion through the venous wall) even though this may alter the course after retrieval of the IVCF.

Methods

A review of 85 consecutive patients undergoing retrieval of IVCF placed at a single center was performed from January 1, 2010 and December 31, 2014. Inferior vena cava filter were examined for presence of intrafilter thrombus at time of retrieval. Filter position and presence of intraluminal thrombus were examined. Patient outcomes, including recurrence of deep vein thrombosis (DVT) and death, were captured at 3 month followup.

Results

Eighty five patients were identified, with intrafilter thrombi found in 69 (81%) patients and venous wall fragments found in 75 (88%) patients. However, their presence was not associated with an increased risk of recurrent venous thromboembolism (VTE) or death during follow up.

Conclusions

Intrafilter thrombi and venous wall fragments are frequently found in removed IVCF but are not associated with a worse prognosis. They may not modify the therapeutic management of patients.

STUDY ON THE NONLINEAR DEFORMATION MECHANICAL PROPERTIES OF A NEW TYPE OF VENA CAVA FILTER

In order to analyze the mechanical properties of a new type of retrievable vena cava filter, the Denali and Aeginsy retrievable filters are selected, and the in vivo and in vitro mechanical properties of the three types of retrievable vena cava filters are compared. The nonlinear deformation process of the filter which is pressed into the transport sheath, flicked and released into the vascular vessel is simulated by using the finite element method, and the mechanical behaviors of the filter and the blood vessel wall are analyzed. During the crimping process, the elastic strain peak value of the filter wall increases with increasing amount of grip. The maximum elastic strain peak value of the three filters is less than 8%, and the safety factor is greater than 2, which meets the strength requirement. Equivalent stress and strain on the vascular wall decreases along the direction of blood flow after the filter is opened. The peak value of equivalent stress and strain on the vascular wall corresponding to Aegisy filter is the largest, and the impact on the vascular wall is the largest. The total displacement of the three filters under the action of thrombus and blood fluids is not more than 80[Formula: see text][Formula: see text]m. The impact of the new filter on the vascular wall is smaller than that of Aegisy filter, and the total displacement after implantation is smaller than that of Denali filter. The results are valuable for the evaluation and clinical application of the new vena cava filter.

Clinical outcomes of retrievable inferior vena cava filters for venous thromboembolic diseases

Aim: To identify literature evidence assessing retrievable inferior vena cava filter (rIVCF) for venous thromboembolic diseases. Methods: A systematic literature search was conducted to identify relevant references from the mainstay English and Chinese bibliographic databases (search period: January 2003 to October 2019). Results: 80 original studies with 11,413 patients were included in this review. The success rates of deploying the six types of rIVCFs ranged from 98.4 to 100.0%. Denali had the highest retrieval success rate (95.4-97.6%). The incidence rates of fracture and perforation associated with retrieving the six rIVCFs were less than 2%. Conclusion: The approved rIVCF had comparable clinical profiles, except that Denali was easier to be retrieved than other rIVCF.

Inferior Vena Cava Filter-Induced Thrombosis: Filter Insertion Prior to Catheter-Directed Thrombolysis and Successful Double-Filter Retrieval after Prolonged Indwelling Time

Extended inferior vena cava (IVC) filter implantation time increases the risk of complications in patients. Here we present the case of a 72-year-old woman with IVC filter-induced thrombosis who underwent catheter-directed thrombolysis with prophylactic IVC filter placement. Two IVC filters were successfully retrieved 70 and 1858 days post placement. The decision to insert an IVC filter should be carefully considered with appropriate indications and all filters should be removed after the risk of deep vein thrombosis has resolved.

A Critical Review of Available Retrievable Inferior Vena Cava Filters and Future Directions

Inferior vena cava filters have been placed in patients for decades for protection against pulmonary embolism. The widespread use of filters has dramatically increased owing at least in part to the approval of retrievable vena cava filters. Retrievable filters have the potential to protect against pulmonary embolism and then be retrieved once no longer needed to avoid potential long-term complications. There are several retrievable vena cava filters available for use. This article discusses the different filter designs as well as the published data on these available filters. When selecting a filter for use, it is important to consider the potential short-term complications and the filters' window for retrieval. Understanding potential long-term complications is also critical, as these devices are approved for permanent placement and many filters are not retrieved. Finally, this article will address research into new designs that may be the future of vena cava filtration.

Evidence-Based Evaluation of Inferior Vena Cava Filter Complications Based on Filter Type

Many inferior vena cava (IVC) filter types, along with their specific risks and complications, are not recognized. The purpose of this study was to evaluate the various FDA-approved IVC filter types to determine device-specific risks, as a way to help identify patients who may benefit from ongoing follow-up versus prompt filter retrieval. An evidence-based electronic search (FDA Premarket Notification, MEDLINE, FDA MAUDE) was performed to identify all IVC filter types and device-specific complications from 1980 to 2014. Twenty-three IVC filter types (14 retrievable, 9 permanent) were identified. The devices were categorized as follows: conical (n = 14), conical with umbrella (n = 1), conical with cylindrical element (n = 2), biconical with cylindrical element (n = 2), helical (n = 1), spiral (n = 1), and complex (n = 1). Purely conical filters were associated with the highest reported risks of penetration (90-100%). Filters with cylindrical or umbrella elements were associated with the highest reported risk of IVC thrombosis (30-50%). Conical Bard filters were associated with the highest reported risks of fracture (40%). The various FDA-approved IVC filter types were evaluated for device-specific complications based on best current evidence. This information can be used to guide and optimize clinical management in patients with indwelling IVC filters.

[Temporary vena caval filters: report on cohort of 72 patients in Grenoble, France]

Patients with a contra-indication for anticoagulation can benefit from temporary vena caval filters for protection against pulmonary embolism or recurrence. The filter can be removed secondarily, once the contra-indication is overcome, enabling better long-term outcome by reducing the risk of thrombotic and mechanic complications inherent in these devices. However, it has been shown in several studies that effective withdrawal rates were low and could be improved by the establishment of protocols and registries. We report a retrospective study of withdrawal in 72 patients in whom an ALN® vena caval filter was implanted at the Grenoble University Hospital over a period of three years with an intention for secondary retrieval. Seventy percent of the indications were related to the coexistence of thrombotic and hemorrhagic conditions. Fifty-five percent of filters were removed, the remaining 45% shared involved patients who died before retrieval (11%), those lost to follow-up (4%), technical failure of retrieval (6%), withdrawal technically unfeasible (3%), retrieval refused by patients (6%) and medical indications for continuing filtration (15%). Despite an effective follow-up of these patients and 91% success rate of withdrawal, nearly one out of two filters remains in place. A long-term follow-up of these patients is needed to learn more about the outcome of these filters.