scholarly journals Design Optimization of Vena Cava Filters: An Application to Dual Filtration Devices

2010 ◽  
Vol 132 (10) ◽  
Author(s):  
Michael A. Singer ◽  
Stephen L. Wang ◽  
Darin P. Diachin
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Inferior Vena Cava ◽  
Objective Function ◽  
Design Optimization ◽  
Inferior Vena ◽  
Vena Cava ◽  
Shear Stresses ◽  
Vena Cava Filters ◽  
Wall Shear

Pulmonary embolism (PE) is a significant medical problem that results in over 300,000 fatalities per year. A common preventative treatment for PE is the insertion of a metallic filter into the inferior vena cava that traps thrombi before they reach the lungs. The goal of this work is to use methods of mathematical modeling and design optimization to determine the configuration of trapped thrombi that minimizes the hemodynamic disruption. The resulting configuration has implications for constructing an optimally designed vena cava filter. Computational fluid dynamics is coupled with a nonlinear optimization algorithm to determine the optimal configuration of a trapped model thrombus in the inferior vena cava. The location and shape of the thrombus are parametrized, and an objective function, based on wall shear stresses, determines the worthiness of a given configuration. The methods are fully automated and demonstrate the capabilities of a design optimization framework that is broadly applicable. Changes to thrombus location and shape alter the velocity contours and wall shear stress profiles significantly. For vena cava filters that trap two thrombi simultaneously, the undesirable flow dynamics past one thrombus can be mitigated by leveraging the flow past the other thrombus. Streamlining the shape of the thrombus trapped along the cava wall reduces the disruption to the flow but increases the area exposed to low wall shear stress. Computer-based design optimization is a useful tool for developing vena cava filters. Characterizing and parametrizing the design requirements and constraints is essential for constructing devices that address clinical complications. In addition, formulating a well-defined objective function that quantifies clinical risks and benefits is needed for designing devices that are clinically viable.

Numerical Analysis of the Hemodynamics and Embolus Capture of a Greenfield Vena Cava Filter

2005 ◽  
Vol 128 (3) ◽  
pp. 360-370 ◽  
Author(s):  
T. N. Swaminathan ◽  
Howard H. Hu ◽  
Aalpen A. Patel
Keyword(s):  
Shear Stress ◽  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Vena Cava Filter ◽  
Central Hole ◽  
Stagnation Zone ◽  
Greenfield Filter ◽  
Vena Cava Filters ◽  
Different Characteristics

Background: Vena Cava filters are used to prevent pulmonary embolism in patients with deep vein thrombosis who are unresponsive to anticoagulation therapy. Various filter designs exist in the market with different characteristics distinguishing them. An understanding of the characteristics of these filters is desirable in order to develop better designs. Methods: A computational fluid dynamical study of the flow over an unoccluded stainless steel Greenfield Vena Cava filter (Boston Scientific, Watertown, MA) to determine its properties has been performed. Simulation of flow over a filter placed axisymmetrically in a rounded inferior vena cava has been performed at a Reynolds numbers of 1000 and the consequences of the flow (by studying parameters like shear stress and stagnation zones) have been discussed. Furthermore, a new finite element based numerical method has been developed that allows the study of capturing properties of Inferior Vena Cava filters. The key idea is the introduction of a thin-wire-model (TWM) that enables a drastic reduction in the computational cost while still maintaining control on the physics of the problem. This numerical technique has been applied to evaluate the embolus capture characteristic of a Greenfield filter. Results: The flow around the unoccluded filter is found to be steady and laminar at the conditions studied. A recirculation/stagnation zone develops immediately downstream of the filter head. This zone is significantly larger when the central hole is occluded. The shear stress and stagnation zone properties for such a flow over a Greenfield filter are compared with existing literature (in vitro studies). A graph showing the regions wherein clots escape or get captured has been determined by a means of numerical simulations. The data has further been analyzed to determine the probability of clot capture as function of the clot size. Conclusions: The stagnation zone formed behind the head of the Greenfield filter is found to be smaller in size when compared to that of the same filter with the central hole occluded. A map of the shear stress distribution shows a small region having the potential for thrombogenesis. The non-Newtonian properties of blood are not seen to cause much variation in the flow field when compared to the Newtonian model. However variation in the cava size leads to a significant change in the shear stresses. This study also establishes a novel method wherein computational means are used to determine the efficacy of clot capturing of filters. These techniques can further be used to compare the different characteristics among filters.

Radiologists' Field Guide to Retrievable and Convertible Inferior Vena Cava Filters

2019 ◽  
Vol 213 (4) ◽  
pp. 768-777 ◽  
Author(s):  
Ronald S. Winokur ◽  
Noy Bassik ◽  
David C. Madoff ◽  
David Trost
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Field Guide ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters

scholarly journals Inferior Vena Cava Filter Retrieval Trends: A Single-Center Experience

TH Open ◽  
2021 ◽  
Vol 05 (01) ◽  
pp. e73-e80
Author(s):  
Filip Ionescu ◽  
Nwabundo Anusim ◽  
Eva Ma ◽  
Lihua Qu ◽  
LeAnn M. Blankenship ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Initial Increase ◽  
Single Institution ◽  
Risk Of Death ◽  
Single Center Experience ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters ◽  
Thrombotic Complications

AbstractRecognition of the adverse events of inferior vena cava filters (VCFs) has prompted the Food and Drug Administration (FDA) to issue safety warnings (2010 and 2014), advocating for removal, once the risk of pulmonary embolism has abated. Despite an initial increase in retrieval rates, these remain low (25–30% at 1 year in 2014). We retrospectively investigated retrieval trends in adults with VCFs placed between 2015 and 2018 at a single institution. The rate of retrievable VCF removal accounting for the competing risk of death was the main outcome. There were 494 VCFs placed (305 retrievable). The cumulative incidence of retrieval remained low (21% at 1 year), even after the second FDA warning (2014). Patients who resumed anticoagulation (AC) at any time were more likely to have retrieval (hazard ratio [HR] = 3.6, p < 0.01) and had higher retrieval rates at every time point (31.4 vs. 7.6% at 1 year). Advanced age (HR = 0.98 per year, p = 0.004), stroke (HR = 0.28, p = 0.028), and active malignancy (HR = 0.42, p = 0.006) predicted nonretrieval. Device-related complications were infrequent (<1%) but thrombotic complications occurred early and were more common for nonretrieved VCFs (17 vs. 12%, p = 0.29). Revision of guidelines to recommend active surveillance for the ability to tolerate AC in the immediate postimplantation period may improve retrieval rates.

An expert spotlight on inferior vena cava filters

2021 ◽  
Author(s):  
Anil Pillai ◽  
Manoj Kathuria ◽  
Maria del Pilar Bayona Molano ◽  
Patrick Sutphin ◽  
Sanjeeva P Kalva
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters

Retrieval of Bard Simon Nitinol inferior vena cava filters: Approaches, technical successes, complications, and clinical outcomes

2021 ◽  
pp. 026835552092598
Author(s):  
Jacob J Bundy ◽  
Jeffrey Forris Beecham Chick ◽  
Ravi N Srinivasa ◽  
Kyle J Cooper ◽  
Joseph J Gemmete ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters ◽  
Venous Thromboembolic Events ◽  
Venous Thromboembolic ◽  
Vena Cava Thrombosis ◽  
Inferior Vena Cava Thrombosis

Objective The Simon Nitinol filter is a bi-level filtration device designed for permanent implantation that is no longer commercially available, but may result in similar complications to current commercially available long term indwelling temporary or permanent filters. Complications related to indwelling inferior vena cava filters include inferior vena cava thrombosis, inferior vena cava penetration, filter migration, and filter fracture. There is a paucity of reports describing the technical aspects related to retrieval of Simon Nitinol filters. Materials and methods This study consisted of five patients with Simon Nitinol filters and describes the indication for retrieval, the retrieval techniques used to remove the filters, technical success, complications, and clinical course. Results The indications for retrieval included: abdominal pain ( n = 2; 40%), iliocaval thrombosis ( n = 1; 20%), identification of an intracardiac filter fragment ( n = 1; 20%), and recurrent venous thromboembolic events ( n = 1; 20%). Retrieval techniques included: biopsy forceps ( n = 3; 60%), excimer laser extraction sheaths ( n = 3; 60%), hangman modified loop snares ( n = 3; 60%), rigid endobronchial forceps ( n = 2; 40%), and balloon deflection ( n = 2; 40%). All filters were successfully retrieved. One patient developed a post-procedural intramuscular hematoma near the site of right internal jugular sheath placement. Conclusions Simon Nitinol filters may be retrieved safely and effectively using advanced inferior vena cava filter retrieval techniques.

Inferior Vena Cava Filters: When to Place and When to Remove

2017 ◽  
Vol 38 (01) ◽  
pp. 084-093 ◽  
Author(s):  
Jonathan Steinberger ◽  
Anshuman Bansal ◽  
John Moriarty
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters

scholarly journals PS130. Factors Impacting Follow-up Care after Placement of Temporary Inferior Vena Cava Filters

2012 ◽  
Vol 55 (6) ◽  
pp. 60S
Author(s):  
Elsie Gyang ◽  
Mohamed Zayed ◽  
E. John Harris ◽  
Jason T. Lee ◽  
Ronald L. Dalman ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters ◽  
Follow Up Care
Sign in / Sign up

Export Citation Format

Share Document