Filter Penetration Research Articles

Assessment of Physical and Mechanical Parameters of Spun-Bond Nonwoven Fabric.

The selection of an appropriate fabric for technical applications, such as protective masks, hinges on a thorough understanding of the fabric's physical and mechanical properties. This study addresses the challenge of selecting the optimal material structure for the upper layer of a protective mask, aiming to ensure adequate breathability while providing effective filtration against airborne particles and contaminants. We assessed and compared the physical-mechanical properties of five polymer spun-bond nonwoven fabrics from different suppliers. Our comprehensive evaluation included, as follows: a visual inspection; light permeability analysis; mass and thickness measurements; elongation and tensile strength tests; breathing resistance assessments; and filter penetration tests with paraffin oil. The results revealed significant variations in performance among the samples, with one fabric consistently outperforming the others across multiple parameters. Notably, this top-performing fabric met or exceeded the EN 149:2001+A1:2009 standard for breathing resistance and filtration efficiency and, in combination with additional filter layers, met the requirements or exceeded class FFP2 (filtering face piece). This study underscores the importance of meticulous material selection and quality control in optimizing PPE (personal protective equipment) performance and user safety, providing valuable insights for mask manufacturers and healthcare professionals.

Numerical analysis of slurry penetration and filter cake formation in front of tunnel face

The bentonite slurry penetration in front of the tunnel face significantly influences the face stability during slurry shield tunneling. In this study, the mechanism of slurry-soil interaction is clarified through the soil microstructural evolution. A transient model coupling the slurry transport and deposition theory is proposed to estimate the slurry penetration and filter cake formation. The time-dependent parameters are considered, including the flow parameters (flow path and pressure gradient) and the hydraulic resistance of soils (soil permeability, porosity, and shear resistance). The proposed model is compared with the infiltration column tests and shows a good agreement.Moreover, a parametric study is conducted to investigate the influence of the soil and slurry properties on the slurry-soil interaction. The results indicate the soil-bentonite relative size is the main factor influencing the formed filter cake type. The filter cake of type Ⅲ (external filter cake and penetration zone) could be formed when the bentonite particle size is between the range of 0.01d10–0.5d10. This type of filter cake has good tightness and could help to improve the face stability when tunneling by slurry shield machine.

Effect of inferior vena cava filter placement position on device complications

BackgroundIndwelling inferior vena cava (IVC) filters can cause complications, including penetration into surrounding structures, migration, and thrombosis of the vena cava. Computational fluid dynamics suggests juxtarenal placement of IVC filters decreases the risk of thrombosis; however, this has not been explored clinically. The present study examines the effect of filter placement position on long-term device complications with an emphasis on IVC thrombosis. We hypothesized that IVC filters placed further caudal to the renal veins were more likely to develop long-term thrombosis. MethodsA retrospective review of the medical records of patients receiving IVC filters at a single tertiary center between 2008 and 2016 was performed. Patients missing follow-up or procedural imaging data were excluded. The placement procedure venograms were reviewed, and the distance from the filter apex to the more inferior renal vein was measured using reported IVC filter lengths for calibration. The patients were divided into three groups according to the tip position relative to the more inferior renal vein: at or superior (group A), 1 to 20 mm inferior (group B), and >20 mm inferior (group C). The patient and procedural characteristics and outcomes were compared between the three groups. The primary end points were IVC thrombosis and device-related mortality. ResultsOf 1497 eligible patients, 267 (17.8%) were excluded. The most common placement position was group B (64.0%). The mean age was lowest in group C, followed by groups A and B (age, 59.5 years, 64.6 years, and 62.2 years, respectively; P = .003). No statistically significant differences were found in the distribution of sex or the measured comorbidities. Group C was the most likely to receive jugular access (group C, 71.7%; group A, 48.3%; group B, 62.4%; P < .001) and received more first-generation filters (group C, 58.5%; group A, 46.6%; group B, 52.5%; P = .045). The short-term (<30-day) and long-term (≥30-day) outcomes, including access site hematoma, deep vein thrombosis, and pulmonary embolism, were uncommon, with no differences between the groups. Cases of symptomatic filter penetration, migration, and fracture were rare (one, one, and three cases, respectively). Although a pattern of increasing thrombosis with more inferior placement was found, the difference between groups was not statistically significant (group A, 1.5%; group B, 1.8%; group C, 2.5%; P = .638). No cases of device-related mortality occurred. All-cause mortality after a mean follow-up of 2.6 ± 2.3 years was 41.3% and did not vary significantly between the groups (P = .051). Multivariate logistic regression revealed that placement position did not predict for short- or long-term deep vein thrombosis, pulmonary embolism, IVC thrombosis, or all-cause mortality after adjustment for the baseline patient characteristics. ConclusionsIVC filters have low rates of short- and long-term complications, including IVC thrombosis. The placement position did not affect the occurrence of device complications in this study.

Evaluation of the effects of wiping decontamination for filter cartridges of elastomeric half-mask respirators (EHMRs)

A major concern among healthcare experts is a shortage of N95 filtering facepiece respirators during a pandemic. If the supply of N95 filtering facepiece respirators becomes limited, reusable elastomeric half-mask respirators (EHMRs) may be used to protect healthcare workers. The focus of this study was to evaluate the effects on the filter performance of wiping decontamination for EHMR P100 filter cartridges. The filter cartridge exterior of EHMR Honeywell, Moldex, and Mine Safety Appliance (MSA) models was wiped using quaternary ammonium and sodium hypochlorite wipes. These filter cartridge properties were assessed including observational analysis and filter performance tests. These wiping and assessing procedures were repeated after each set of wiping cycles (50, 100, 150, 200, and 400 cycles) to determine the effects of wiping decontamination. For sodium hypochlorite wipes, Honeywell, Moldex, and MSA models passed the National Institute for Occupational Safety and Health (NIOSH) liquid particulate penetration criteria for all wiping cycles from 50 to 400 (penetrations<0.014%). For quaternary ammonium wipes, filter penetrations of Moldex failed (penetrations>0.03%) after 150 cycles, while the filter penetrations of Honeywell and MSA passed for all wiping cycles (penetrations ≤0.013%). Wiping decontamination methods using sodium hypochlorite and quaternary ammonium wipes could be considered promising decontamination candidates for Honeywell, Moldex, and MSA reuse, except for the wiping number selection for Moldex (<150 cycles) when using the quaternary ammonium wipe.

Methods for cutaneous penetration assessment of organic UV filters - a review

Sunscreens are currently considered cosmetic assets and their use has considerably increased since consumers have become greatly aware of the damages induced by ultraviolet (UV) radiation on the skin, such as premature aging and cancer. However, concerns have arisen over the percutaneous absorption of UV filters. In order to ensure both efficacy and safety, sunscreens need to remain in the outermost layers of the stratum corneum, because their penetration into the dermis can cause systemic effects. Herein, a review was conducted of specialized literature published between 2000 to 2020, clustering studies focused on the skin penetration of UV filters. In this context, different in vitro and in vivo methodologies employed to assess the penetration of such compounds are highlighted, such as those based on tape stripping and diffusion cells. When combined with analytical methods, such as high-performance liquid chromatography, it is possible to trace a profile of the penetration of UV filters and elucidate factors that interfere with this phenomenon. Moreover, studies have been carried out on dissemination strategies that aim to encapsulate the molecules of UV filters, and/or change their physicochemical characteristics, in effort to increase the efficacy and safety of these formulations. Keywords: Franz cell; sunscreens; percutaneous penetration; tape stripping

Safety and efficacy of the VenaTech™ Retrievable inferior vena cava filter: a first-in-man single-center prospective study

BackgroundVenous thromboembolism (VTE) is a frequent condition worldwide, associated with significant morbidity and mortality. Though its primary treatment is anticoagulation, the placement of an inferior vena cava (IVC) filter is recommended in patients with some comorbidities. The objectives of this study were to evaluate the clinical safety and efficacy of the Venatech® retrievable IVC filter. This open-label prospective single-center study was conducted on 40 consecutive patients requiring temporary or permanent IVC filtration. Patient characteristics, technical success rates of filter placement and removal, and the occurrence of complications were assessed. Follow-up imaging was performed using CT-scan before retrieval or at 6 months in the permanent indication population.ResultsThe filter was successfully implanted at the intended location in all the patients. Retrieval was attempted in 21 (52.5%) patients after a mean period of 50 days (range: 6–94 days), and the filter was successfully removed in 18 patients (85.7%). Reason for retrieval failure was filter with trapped thrombus (n = 2) and a > 15° tilt (n = 1). No complication was observed during the filter placement and retrieval. Follow-up imaging available in 30 patients (75%) demonstrated deep filter penetration (> 3 mm) in four patients (13.3%), severe filter tilt (> 15o) in five patients (16.7%), filter with trapped thrombus in three patients (10%), but no fracture or IVC thrombosis.ConclusionThis prospective study showed encouraging preliminary results of the safety and efficacy of the Venatech® retrievable IVC filter. The filter was easily delivered in the intended position and successfully removed in a high percentage of patients.Trial registrationClinicalTrials.gov Identifier: NCT02674672

MS imaging and absorption methods visualizing sun filter skin spatial distribution and penetration.

Sunscreens must now be effective in protecting skin from ultraviolet, as well as visible/infrared radiation. Here, TriAsorB, a new broad-spectrum sun filter, was formulated with three other sunscreens and their distribution on human skin was studied using a standard penetration protocol and two novel mass spectrometry imaging techniques: atmospheric pressure matrix assisted laser desorption ionization (AP-MALDI) coupled to high resolution mass spectrometry and time of flight - secondary ion mass spectrometry (ToF-SIMS). The standard penetration protocol showed that sun filters absorption was very low, with most of the dose recovered at the surface (none entered the receptor fluid). Absorption was not increased in damaged skin. The results were confirmed by AP-MALDI and ToF-SIMS imaging of the spatial distribution of molecular species in cross-section samples of human skin. Each sun filter was detected on or in the stratum corneum, with a good homogenous coverage over the valleys and peaks of the skin, and correlated well with the distribution of endogenous biomarkers. In conclusion, conventional and novel imaging analysis methods showed that the sun filters remained mainly on the skin surface after topical application. Mass spectrometry imaging is a promising complementary approach to traditional skin penetration studies to visualize penetration of compounds.

Influence of Exercise on Inferior Vena Cava Wall Interaction with Inferior Vena Cava Filters: Results of a Pilot In Vivo Porcine Study

Abstract Objectives The aim of this study was to assess the effect of mild exercise on inferior vena cava (IVC) filter interaction with imaging and pathological features with the neighboring vessel wall utilizing a porcine model. Materials and Methods After Institutional Animal Care and Use Committee (IACUC) approval, retrievable Option Elite IVC filters were implanted in six Yorkshire pigs utilizing the right common femoral vein approach under general anesthesia. Group A (n = 4) pigs remained sedentary for 4 weeks. Group B (n = 2) pigs were exercised using a harness and treadmill for 10 minutes/day for 4 days/week. At approximately 4 weeks, IVC venograms were performed and the pigs were sacrificed. After laparotomy, the IVC was ligated above and below the filter, excised and fixed in formalin. Gross and histological examination of the IVC was performed. Gross images of each sample were captured before removal of the filters. One longitudinal, one tangential, and five transverse representative sections were processed for paraffin sectioning and hematoxylin and eosin slides were prepared. A pathologist examined all tissues to assess differences between normal vein, group A and group B pigs. The pathologist provided an overall assessment and representative images. Results All IVC filter implantations were technically successful without adverse effects. There was no incidence of caval thrombosis, filter strut fracture, or filter migration in either group. On gross pathological examination, IVC of the pigs in group B demonstrated more perivascular and mural fibrosis than those pigs in group A. Histopathological findings correlated with gross findings. Conclusions In this pilot study, there were no incidence of IVC filter strut fracture, penetration or IVC occlusion in sedentary or exercised pigs. However, there tended to be more perivascular and mural fibrosis on pathological examination of inferior vena cavas from exercised pigs. Further larger scale studies may employ the porcine model to further understand the role exercise may play on IVC filter and caval wall interaction.

Fast Identification of the Failure of Heavy-Duty Diesel Particulate Filters Using a Low-Cost Condensation Particle Counter (CPC) Based System

The penetration of diesel particulate filters (DPFs) in the market is growing fast. However, in the current inspection/maintenance (I/M) regulation for these vehicles, particulate emissions were capped with smoke opacity, which is incompetent to identify the excessive particle number (PN) induced by non-major DPF failures such as small cracks in substrate. This research aimed at developing a fast identification method for such malfunctioning vehicles using a low-cost condensation particle counter (CPC). To verify the effectiveness of idle PN test, 33 China-5 and China-6 heavy-duty vehicles fueled with diesel and natural gas (NG) were tested using the regulatory portable emission measurement system (PEMS) as per China-6 protocol and idle PN tests using a low-cost CPC-based system. PN emissions from China-6 vehicles with malfunctioning DPFs were at a similar level to those from China-5 vehicles (without DPF), which were significantly higher than the proper counterparts. Idle PN tests using a CPC-based system managed to identify the vehicles with DPF failures. Volumetric PN concentrations of these vehicles were much higher than those of the proper ones. This study proved that an easy, fast, and low-cost procedure could be used to screen out those high emitters with DPF failure.

Experimental Study on the Leakage Characteristics of Filter Cassettes

Hazardous aerosol particles harmful to human health can be found in various workplaces. Filter cassettes are often used for air sampling to measure dust concentration in the air. However, filter cassettes are prone to leakage if not correctly assembled, potentially causing exposure data to be underestimated. This study aims to examine all potential leak routes, mechanisms, and contributions to the leakage to find solutions to minimize the leaks. The membrane filter and the support pad were held using 37-mm transparent styrene two-piece filter cassettes of two brands (A & B). They were assembled with a homemade manual presser, which can apply a controlled force onto the cassette from 40 to 350 N. To measure the direct force required to press on the top piece and tightly clamp both the filter and the backup pad, the top part of a typical cassette A was filed to prevent contact and friction with the bottom piece. The interface of the top and bottom pieces of the cassette was sealed from the outside with a sealing shrink band to prevent external leakage. Ambient aerosols were used as challenge agents. The aerosol number concentrations upstream and downstream of the filter cassette were measured using a condensation particle counter. The sampling time was set at one minute. The pressure drop across the filter cassette was measured using a pressure transducer calibrated using an inclined manometer. A sampling flow of 0.3 L min–1 in the condensation particle counter (CPC) was chosen for low filter penetration. The results showed that the filed cassette A suffered from external leakage, regardless of whether it held the filter and/or the backup pad. For the normal cassette A, leakage was a function of the assembly press force. When the assembly force increased from 150 to 210 N, total aerosol penetration (through filer, pad, and other leaks) decreased sharply from 2.1% to 0.004%. Sealing with a shrink band could further reduce aerosol penetration to 0.001 %, while the pressure drop rose to 17 mmH2O. The re-assembling experiments showed that the service life decreased with increasing press force applied. For cassette A, the service life was 14 times when re-assembled with 210 N, while the service life dropped to 6 times when the force was 300 N. In conclusion, sufficient press force is needed for cassette assembly to prevent both internal and external leakages. Despite the only subtle difference in cassette dimensions, the minimum assembly forces required for the two cassette brands differ, 210 N for brand A and 330 N for brand B. Use of a sealing shrink band is strongly recommended because it helps reduce external leakage, provides space for labeling, and prevents sample contamination during filter retrieval.

A simple and cheap aerosol penetrometer for filter testing using an electronic cigarette.

Background: During the coronavirus disease 2019 (COVID-19) pandemic face masks grew in importance as their use by the general population was recommended by health officials in order to minimize the risk of infection and prevent further spread of the virus. To ensure health protection of medical personnel and other system relevant staff, it is of considerable interest to quickly test if a certain lot of filtering facepiece masks meets the requirements or if the penetration changes under different conditions. As certified penetrometers are rather expensive and were difficult to obtain during the COVID-19 pandemic, we describe two quite simple and cheap methods to quickly test the filter penetration based on an electronic cigarette. Methods: The first method uses a precision scale, the second method uses a light scattering detector to measure the filter penetration. To make sure these two methods yield reliable results, both were tested with freshly cut filter samples covering the range of approx. 2 % to 60 % filter penetration and compared to the results of a certified penetrometer. Results: The comparison of the two methods with the certified penetrometer showed a good correlation and therefore allow a quick and rather reliable estimation of the penetration. Conclusions: Several examples about the use of faulty masks and the resulting health risks show that simple, fast, cheap and broadly available methods for filter characterization might be useful in these days.

A simple and cheap aerosol penetrometer for filter testing using an electronic cigarette.

Background: During the coronavirus disease 2019 (COVID-19) pandemic face masks grew in importance as their use by the general population was recommended by health officials in order to minimize the risk of infection and prevent further spread of the virus. To ensure health protection of medical personal and other system relevant staff, it is of considerable interest to quickly test if a certain lot of filtering facepiece masks meets the requirements or if the penetration changes under different conditions. As certified penetrometers are rather expensive and were difficult to obtain during the COVID-19 pandemic, we describe two quite simple and cheap methods to quickly test the filter penetration based on an electronic cigarette. Methods: The first method uses a precision scale, the second method uses a light scattering detector to measure the filter penetration. To make sure these two methods yield reliable results, both were tested with freshly cut filter samples covering the range of approx. 2 % to 60 % filter penetration and compared to the results of a certified penetrometer. Results: The comparison of the two methods with the certified penetrometer showed a good correlation and therefore allow a quick and rather reliable estimation of the penetration. Conclusions: Several examples about the use of faulty masks and the resulting health risks show that simple, fast, cheap and broadly available methods for filter characterization might be useful in these days.

Fit and filter integrity of a respirator mask after multiple cycles of autoclave

BackgroundThe COVID-19 pandemic has led to profound shortages in personal protective equipment worldwide. The availability of filtering facepiece class 3 (FFP3) respirators could be greatly increased if they could be...

A simple and cheap aerosol penetrometer for filter testing using an electronic cigarette.

Background: During the coronavirus disease 2019 (COVID-19) pandemic face masks grew in importance as their use by the general population was recommended by health officials in order to minimize the risk of infection and prevent further spread of the virus. To ensure health protection of medical personal and other system relevant staff, it is of considerable interest to quickly test if a certain lot of filtering facepiece masks meets the requirements or if the permeability changes under different conditions. As certified penetrometers are rather expensive and were difficult to obtain during the COVID-19 pandemic, we describe two quite simple and cheap methods to quickly test the filter permeability based on an electronic cigarette. Methods: The first method uses a precision scale, the second method uses a light scattering detector to measure the filter penetration. To make sure these two methods yield reliable results, both were tested with freshly cut filter samples covering the range of approx. 2 % to 60 % permeability and compared to the results of a certified penetrometer. Results: The comparison of the two methods with the certified penetrometer showed a good correlation and therefore allow a quick and rather reliable estimation of the permeability. Conclusions: Several examples about the use of faulty masks and the resulting health risks show that simple, fast, cheap and broadly available methods for filter characterization might be useful in these days.

Hydrogen peroxide vapor decontamination of N95 respirators for reuse.

The coronavirus disease 2019 (COVID-19) pandemic has led to global shortages of N95 respirators. Reprocessing of used N95 respirators may provide a higher filtration crisis alternative, but whether effective sterilization can be achieved for a virus without impairing respirator function remains unknown. We evaluated the viricidal efficacy of Bioquell vaporized hydrogen peroxide (VHP) on contaminated N95 respirators and tested the particulate particle penetration and inhalation and exhalation resistance of respirators after multiple cycles of VHP. For this study, 3M 1870 N95 respirators were contaminated with 3 aerosolized bacteriophages: T1, T7, and Pseudomonas phage phi-6 followed by 1 cycle of VHP decontamination using a BQ-50 system. Additionally, new and unused respirators were sent to an independent laboratory for particulate filter penetration testing and inhalation and exhalation resistance after 3 and 5 cycles of VHP. A single VHP cycle resulted in complete eradication of bacteriophage from respirators (limit of detection 10 PFU). Respirators showed acceptable limits for inhalation/exhalation resistance after 3 and 5 cycles of VHP. Respirators demonstrated a filtration efficiency >99 % after 3 cycles, but filtration efficiency fell below 95% after 5 cycles of HPV. Bioquell VHP demonstrated high viricidal activity for N95 respirators inoculated with aerosolized bacteriophages. Bioquell technology can be scaled for simultaneous decontamination of a large number of used but otherwise intact respirators. Reprocessing should be limited to 3 cycles due to concerns both about impact of clinical wear and tear on fit, and to decrement in filtration after 3 cycles.

Prevalence and Characterization of Interaction of Retrievable Inferior Vena Cava Filters with the Spine in Patients Undergoing Complex Filter Removal

PurposeTo examine spinal interaction types and prevalence of inferior vena cava (IVC) filters in patients presenting for complex filter removal. Materials and MethodsThe records of 447 patients presenting for complex removal of IVC filters were reviewed, including patient demographics, IVC filter dwell time, filter fracture status, and computed tomography (CT) evidence of filter interaction with the spine. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disc. Patients with evidence of filter penetration and spinal interaction had abdominal CT that preceded filter removal assessed by 2 interventional radiologists to categorize the type of spinal interaction, including bony reaction and osteophyte formation. ResultsCT evidence of spinal interaction by the filter was found in 18% of patients (80/447). Interaction with the spine was more common in single point of fixation filters than filters with rails (P = .007) and was more likely in filters with round wires than flat wires (P = .0007). Patients with interaction had longer dwell times (mean [SD] 5.7 [4.46] y) compared with patients without interaction (mean [SD] 3.2 [3.85] y); this relationship was significant (P < .0001). Women were more likely than men to experience filter/spine interaction (P = .04). Filters with spinal interaction were more likely to be fractured (P = .001). Filter interaction was found in 38% (30/78) of patients with symptoms, including chest and back pain, compared with 14% (50/369) of patients without symptoms (P < .0001, odds ratio 3.99). ConclusionsRetrievable IVC filters may interact with the spine. These interactions are associated with longer filter dwell times, female sex, and round wire filter construction.

Triaging of respiratory protective equipment on the assumed risk of SARS-CoV-2 aerosol exposure in patient-facing healthcare workers delivering secondary care: a rapid review

ObjectivesIn patient-facing healthcare workers delivering secondary care, what is the evidence behind UK Government personal protective equipment (PPE) guidance on surgical masks versus respirators for SARS-CoV-2 protection?DesignTwo independent reviewers performed...

Trajectory simulation of penetration and particle deposition of electret media with bipolarly charged fibers

Trajectory analysis has been extensively applied to simulate the penetration and loading processes of electret filters. However, there is no available literature related to trajectory analysis simu...

Market Surveillance of Filtering Facepiece (FFP)of Respirator Protective Equipment (RPE): Malaysian Perspectives

Filtering Facepieces (FFPs) are commonly use as personal protective equipment (PPE). It is disposable Respiratory Protective Equipment (RPE). Basically it is used for protection against dusts, particles and aerosols. Available in 3 classes FFP1, FFP2 and FFP3. Various Respiratory Protective Equipment (RPE) offered in Malaysia’s market today are not being controlled and monitored by expert bodies and authorities. This has led to various perceptions among the users, especially on the quality and safety and health features of the products offered by different companies. This situation also makes it difficult for users to decide appropriate RPE based on quality and standard compliance. The tendency of consumers to choose RPE is mainly based on the price but not the technical aspect of RPE. Hence, the RPE they purchased not necessary enhance user protection, as there is no guidance available to assist user before they purchase the most appropriate RPE. This study describes market surveillance testing of FFP2 respirator from 30 different brand in Malaysia. The objective is to determine performance requirements required by the Malaysia standard. 3 types of testing were used on this study Filter Penetration, Breathing Resistance and Carbon Dioxide Content. All testing was carried out based on Malaysia Standard; MS 2323:2010 and MS2553:2014.All 30 sample were passed the breathing resistance and carbon dioxide content except 10 brand was failed the filter penetration testing. It is noticed that the user and consumer should aware with their PPE basic requirement.

Abstract No. 671 The effect of inferior vena cava size on filter complications: one size does not fit all

To determine the effect of inferior vena cava (IVC) size on development of complications as determined on post placement CT scan, including filter tilt, penetration, and thrombosis. Patients that underwent IVC filter placement between March 2015-December 2017 were included in the study. Coronal and sagittal CT scan images before placement of the filter were used to measure the medio-lateral (ML) and antero-posterior (AP) diameters of the IVC, 2 cm below the right renal vein. Two- dimensional (2D) axial IVC size at this level was then calculated using the ML and AP diameters. CT scan images after placement of the filter were reviewed for any complications, including filter tilt, penetration and thrombosis. IVC filter ML diameter, AP diameter and 2D axial sizes were then compared between patients with and without complications in CT scan. A total of 86 patients (female = 59%, male = 41%, age: 67 ± 14.1 years) were enrolled. The CT scan before placement of filter was available at 2.2 ± 5.2 months. The complications noted in the post filter placement CT scan (interval = 5.4 ± 6.75 months) were tilt in 32(37%) patients, penetration in 4(4.7%) and thrombosis in 8(9.3%) patients. Patients with tilt had significantly larger 2D axial IVC size compared to patients without tilt. Almost significant association was also noted in terms of ML diameter; however, no significant difference was noted in terms of AP diameter. There is significant association between the two-dimensional (2D) size of the IVC and future complications such as tilt noted on post placement CT scan. Two-dimensional evaluations of the IVC could provide clinicians better insight regarding the anatomy of the IVC, particularly considering the variability of the IVC size with hydration status and respiration. Future large sample studies should further define the filter specific thresholds.Tabled 1IVC AP diameter (mm)IVC ML diameter (mm)No tilt (n=54)15.9 ± 4.819.3 ± 2.9992.7 ± 400.7Tilt (n=32)17.7 ± 4.820.8 ± 3.61184.7 ± 452.8P value0.110.050.04 Open table in a new tab