In Vitro Evaluation of Optionally Retrievable and Permanent IVC Filters

Mahnken, Andreas H.; Pfeffer, Joachim; Stanzel, S.; Mossdorf, Anne; Günther, Rolf W.; Schmitz‐Rode, Thomas

doi:10.1097/rli.0b013e318036b42b

Cited by 18 publications

(7 citation statements)

References 30 publications

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“…In vitro studies of the Cook Celect filter have shown promising results. Mahnken et al evaluated seven optionally retrievable and permanent IVC filters 18 . In single clot exposure the highest mean capture rate was achieved with the Celect filter (90.4% ± 15.7%.…”

Section: Discussionmentioning

confidence: 99%

Initial experience in 115 patients with the retrievable Cook Celect vena cava filter

et al. 2009

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SummaryThe aim of this study was to evaluate our experience with the retrievable Cook Celect inferior vena cava (IVC) filter (William Cook, Europe) with regard to insertion, efficiency, ease of retrieval, and any associated complications. A retrospective review was performed of 115 patients (41 female, 74 male, mean age 47.97 years) who underwent Cook Celect IVC filter insertion between December 2005 and October 2007. Filter insertion was successful in all patients. Of the 115 filters inserted, 57 have been successfully retrieved (49.6%) to date. The successful retrieval rate from attempted retrieval was 93.4%. The mean dwell time of successfully retrieved filters was 114.9 days (range 14-267 days). Failed retrievals were due to a thrombosed vena cava (n = 1) and endothelialisation of the filter (n = 3). In the failed retrieval group the mean implantation time was 142 days (range 78-211 days). While this is the first retrospective clinical study on the Cook Celect filter, results to date are promising. We demonstrated an efficacious filter with a high successful retrieval rate of 93.4% and a low complication rate. The filter was assessed with extended dwell times (range 14-267 days). Failed retrieval secondary to hook endothelialisation continues to be an issue with this filter. We recognize that a limitation of our study was the lack of systematic followup for clinically silent complications. Further studies to evaluate longer term outcomes and effectiveness of this filter are warranted.

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Section: Discussionmentioning

confidence: 99%

Initial experience in 115 patients with the retrievable Cook Celect vena cava filter

et al. 2009

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“…Researchers have studied the clot capture efficiency of IVC filters with a number of different clot materials, including blood clots made from human, bovine, porcine, ovine blood,2,4,5 fishing worms molded from soft plastic resin containing dioctyl phthalate,6,7 and even cubes of chicken fat 8. To evaluate IVC filter performance, Jaeger et al injected synthetic clots cast from 3.5% polyacrylamide (PA) hydrogels into a flow loop containing a blood-mimicking solution of glycerin and water 9,10.…”

Section: Introductionmentioning

confidence: 99%

Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

Robinson¹,

Herbertson²,

Das³

et al. 2013

MDER

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The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA) synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC) filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm), length-to-diameter ratios (1:1, 3:1, 10:1), and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm) between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the filter in the IVC model flow loop, they were more likely to pass between the peripheral filter struts, while the softer, physiological clots tended to fold and were captured by the filter. These experiments demonstrated that if synthetic clots are used as a surrogate for animal or human blood clots for in vitro evaluation of vena cava filters, the material properties (eg, elastic modulus) and dynamic behavior of the surrogate should first be assessed to ensure that they accurately mimic an actual blood clot within the body.

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“…The authors could only identify six studies testing Greenfield filters with at least one clot size the same as used in this study, displayed in Table III. 24–29 All of these differed in the venous simulator loop, clot composition, and parameters under which filters were tested. CCE for each clot size in this study fell within the range of capture efficiencies found in the identified studies, with the exception of the 7×10 mm clot size, for which no study could be found to compare, and for the 10×24 mm clot size, for which the 100% CCE was extremely close to the 98% identified by Mahnken et al 24 …”

Section: Discussionmentioning

confidence: 99%

“…Some relied on only 10 trials for a single clot size; others combined trials from different setup parameters for each clot size, introducing variability not captured in the output statistic; others vary the number of trials without clearly defined justification. 21,24–27,30,31 Using such small numbers of trials especially with the smaller clot sizes creates large standard error for binomial distributions. Assigning the number of trials to achieve a standard error of 5% as performed in this study ensured adequate number of trials to yield high confidence in the statistical parameters.…”

Section: Discussionmentioning

confidence: 99%

In vitro evaluation of clot capture efficiency of an absorbable vena cava filter

Dria

Eggers

2016

Journal of Vascular Surgery: Venous and Lymphatic Disorders

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Purpose Determine the in-vitro clot capture efficiency (CCE) of an investigational absorbable inferior vena cava filter (IVCF) versus the Greenfield IVCF. Materials and Methods Investigational absorbable and Greenfield filters were challenged with polyacrylamide (PAM) clot surrogates ranging from 3×5 to 10×24 mm (dia. × length) in a flow loop simulating the venous system. Filters were challenged with clots until CCE standard error of 5% or less was achieved under binomial statistics. Pressure gradients across the filters were measured for the largest size clot, enabling calculation of forces on the filter. Results The absorbable IVCF in-vitro CCE was statistically similar to the Greenfield filter for all clot sizes apart from the 3×10 mm clot, where there was statistically significant difference between filter CCE’s (absorbable filter: 59%, Greenfield: 31%, p=0.0001). CCE ranged from an average 32% for the 3×5 clot to 100% for 7×10 mm and larger clots for the absorbable IVCF. Pressure gradient across the absorbable filter with 10×24 mm clot averaged 0.14 mmHg, corresponding to a net force on the filter of 2.1×10−3 N, compared to 0.39 mmHg or 5.8×10−3 N (p<0.001) for the Greenfield filter. Conclusions CCE of the absorbable filter was statistically similar to, or an improvement upon, the Greenfield stainless steel filter for all clot sizes tested. CCE of the Greenfield filter in this study aligned with data from previous studies. Given the efficacy of the Greenfield filter in attenuating the risk of pulmonary embolism, the current study suggests the absorbable filter may be a viable candidate for subsequent human testing.

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In Vitro Evaluation of Optionally Retrievable and Permanent IVC Filters

Abstract: Optionally retrievable IVC filters are efficient. Clot size, IVC filter type, and position significantly influence capture rate. Deliberate selection of the most efficient IVC filter and concentric positioning are important to ensure optimal results.

Cited by 18 publications

References 30 publications

Initial experience in 115 patients with the retrievable Cook Celect vena cava filter

Initial experience in 115 patients with the retrievable Cook Celect vena cava filter

Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

In vitro evaluation of clot capture efficiency of an absorbable vena cava filter

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