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The goal of this research is to investigate the effects of Ohmic heating, heat generation, and viscous dissipative flow on magneto (MHD) boundary-layer heat transmission flowing of Jeffrey nanofluid across a stretchable surface using the Koo-Kleinstreuer-Li (KKL) model. Engine oil serves as the primary fluid and is suspended with copper oxide nanomolecules. The governing equations that regulate the flowing and heat transmission fields are partial-differential equations (PDEs) that are then converted to a model of non-linear ordinary differential equations (ODEs) via similarity transformation. The resultant ODEs are numerically resolved using a Keller box technique via MATLAB software that is suggested. Diagrams and tables are used to express the effects of various normal liquids, nanomolecule sizes, magneto parameters, Prandtl, Deborah, and Eckert numbers on the velocity field and temperature field. The outcomes display that the copper oxide-engine oil nanofluid has a lower velocity, drag force, and Nusselt number than the plain liquid, although the introduction of nanoparticles raises the heat. The heat transference rate is reduced by Eckert number, size of nanomolecules, and magneto parameter rising. Whilst, Deborah number is shown to enhance both the drag-force factor and the heat transfer rate. Furthermore, the discoveries reported are advantageous to upgrading incandescent lighting bulbs, heating, and cooling equipment, filament-generating light, energy generation, multiple heating devices, and other similar devices.
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Pakistan, where chronic myeloid leukemia constitutes around 80% of all myeloproliferative disorders, has been exploring multiple avenues in order to ensure the accessibility and affordability of imatinib and nilotinib. While most provinces of the country have joined hands with a pharmaceutical company to dispense free anti-CML medicines as part of a public-private partnership, the patients are still facing numerous challenges in the form of geographical disparity in the availability of these medicines, other out-of-pocket expenditures and most importantly, the uncertainty associated with the long-term continuation of this public-private endeavor due to procedural delays. In light of these predicaments, channeling resources towards research and development, fostering partnerships between government and NGOs and tapping into the domain of compulsory licensing appear to be the most sustainable solutions.
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Leucemia Mielógena Crónica BCR-ABL Positiva , Asociación entre el Sector Público-Privado , Humanos , Mesilato de Imatinib/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Pirimidinas , Inhibidores de Proteínas Quinasas/uso terapéuticoRESUMEN
In the current study, a vertical, 3D-heated plate is used to replicate the generation of heat energy and concentration into Prandtl liquid. We discuss how Dufour and Soret theories relate to the equations for concentration and energy. In order to see how effectively particles, interact with heat and a solvent, hybrid nanoparticles are used. It does away with the phenomena of viscous dissipation and changing magnetic fields. The motivation behind the developed study is to optimize solvent and heat storage uses in the biological and industrial domains. This article's major goal is to explore the aspects of thermal energy and mass transfer that influence how nanoparticles, hybrid nanoparticles, and 3D melting surface sheets behave. Variable thermal efficiency and variable mass transfer are combined. The system of generated PDEs (difference equations) includes the concentration, velocity, and heat energy equations. The numerical calculations are done for Silver (Ag), Molybdenum Disulfide (MoS2) nanoparticles with Ethylene glycol (C2H6O2) as the base fluid using a boundary layer approach to the mathematical formulation. The system of ODEs is formulated through transformations in order to find a solution. A Galerkin finite element algorithm (G-FEA) is adopted to analyze various aspects versus different parameters. It has been found that motion into hybrid nanoparticles is reduced by motion into nanoparticles. Additionally, differences in heat energy and solvent particle sizes are associated with modifications in magnetic, Dufour, Eckert, and Soret numbers. In contrast to hybrid nanostructures, the output of thermal energy is usually observed to be substantially higher. The magnetic field parameter decreases the particle velocity. In contradiction to the Eckert number, bouncy parameter, and magnetic parameter set values, the maximum quantity of heat energy is obtained. variable thermal conductivity's function. The 3D heated vertical surface convective heat transfer of nanofluids and hybrid nanofluids under the impact of a heat source, thermal radiation, and viscous dissipation has not yet been studied, as far as the authors are aware.
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Researchers across the world have tried to explore the impact of non-Newtonian liquid flowing via an extendable surface with the inclusion of various effects due to its industrial and engineering applications like polymer production, paper production, filament extrusion from a dye, etc. This study investigates the behavior of stagnation point flow of Carreau liquid attached with inclined magnetic effect and spectral relaxation approach is utilized here for the numerical outcome. In this study, a few other vital features are attached like the quadratic multiple regression model for Nusselt number evaluation, passive control of nanoparticles, viscus heating thermophoresis, Brownian motion, and mixed convection, etc. Velocity disbursement visibility is analyzed by placing an inclined magnetic field. Physical model generates collection of partial differential equations (PDEs) and these PDEs are moved into ordinary differential equations by a similarity transformations scheme. Further for numerical process, spectral relaxation method is used. Growth in K causes a reduction in velocity because this parameter K creates the impedance to flowing resulting in confines the movement of liquid in restricted the plate. Direct relation is found between [Formula: see text] and the energy file. In the case of S > 1, physically it is a representation of Joule and viscous dissipations. This article is novel in its sense that the influence of oblique magnetic force and second order velocity slippage on Carreau nano liquid and its numerical computation with help of the spectral relaxation method has never been done before. Furthermore, the quadratic multiple regression model has been employed to find the heat transition rate in the status of the Nusselt number.
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During thermal radiation treatments, heat therapies, and examination procedures like scans and X-rays, the cylindrical blood vessels may get stretched; meanwhile, the blood flow through those blood vessels may get affected due to temperature variations around them. To overcome this issue, this work was framed to explore the impact of heat transmission in a Carreau fluid flow (CFF) through a stretching cylinder in terms of the nonlinear stretching rate and irregular heat source/sink. Temperature-dependent thermal conductivity and thermal radiation are taken into consideration in this study. To tranform complicated partial differential equations into ordinary differential equations, appropriate similarity variables are used. For a limited set of instances, the derived series solutions are compared to previously published results. For linear and nonlinear stretching rates, graphs and tables are used to examine the influence of an irregular heat source/sink on fluid movement and heat transfer. The research outcomes demonstrate that the heat source and nonlinear stretching rate cause a disruption in the temperature distribution in the fluid region, which can alter the blood flow through the vessels. In all conditions except for the heat in an internal heat sink, the nonlinear stretching situation improves the velocity and heat profile. Furthermore, with the increase in the values of the Weissenberg number, the temperature profile shows opposing features in a shear-thickening fluid and shear-thinning fluid. For the former n > 1, the blood fluidity gets affected, restricting the free movement of blood. For the latter, n < 1, the phenomenon is reversed. Other industrial applications of this work are wire coating, plastic coverings, paper fabrication, fiber whirling, etc. In all of those processes, the fluid flow is manipulated by thermal conditions.
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The study of hydromagnetic mixed convection flow of viscoelastic fluid caused by a vertical stretched surface is presented in this paper. According to this theory, the stretching velocity varies as a power function of the displacement from the slot. The conservation of energy equation includes thermal radiation and viscous dissipation to support the mechanical operations of the heat transfer mechanism. Through the use of an adequate and sufficient similarity transformation for a nonlinearly stretching sheet, the boundary layer equations governing the flow issue are converted into a set of ordinary differential equations. The Keller box technique is then used to numerically solve the altered equations. To comprehend the physical circumstances of stretching sheets for variations of the governing parameters, numerical simulations are made. The influence and characteristic behaviours of physical parameters were portrayed graphically for the velocity field and temperature distributions. The research shows that the impact of the applied magnetic parameter is to improve the distribution of the viscoelastic fluid temperature and reduce the temperature gradient at the border. Temperature distribution and the associated thermal layer are shown to have improved because of radiative and viscous dissipation characteristics. Radiation causes additional heat to be produced in liquid, raising the fluid's temperature. It was also found that higher velocities are noticed in viscoelastic fluid as compared with Newtonian fluid (i.e., when K = 0).
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Sun based energy is the chief source of heat from the sun, and it utilizes in photovoltaic cells, sun-based power plates, photovoltaic lights and sun-based hybrid nanofluids. Specialists are currently exploring the utilization of nanotechnology and sun-based radiation to further develop flight effectiveness. In this analysis, a hybrid nanofluid is moving over an expandable sheet. Analysts are presently exploring the utilization of nanotechnology and sunlight-based radiation to further develop avionics productivity. To explore the heat transfer rate phenomenon, a hybrid nanofluid stream is moving towards a trough having a parabolic type shape and is located inside of solar airplane wings. The expression used to depict the heat transfer phenomenon was sun based thermal radiation. Heat transfer proficiency of airplane wings is evaluated with the inclusion of distinguished effects like viscous dissipation, slanted magnetic field and solar-based thermal radiations. The Williamson hybrid nanofluid past an expandable sheet was read up for entropy generation. The energy and momentum expressions were solved numerically with the utilization of the Keller box approach. The nano solid particles, which are comprised of copper (Cu) and Graphene oxide, are dispersed utilizing SA (Sodium alginate) as an ordinary liquid (GO). A huge number of control factors, for example, temperature, shear stress, velocity, frictional element along with Nusselt number are investigated in detail. Intensification of thermal conduction, viscous dissipation and radiation improve the performance of airplane wings subjected to heat transmission. Hybrid nanofluid performance is much better than the ordinary nanofluid when it comes to heat transmission analysis.
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A mathematical model of 2D-double diffusive layer flow model of boundary in MHD Maxwell fluid created by a sloping slope surface is constructed in this paper. The numerical findings of non-Newtonian fluid are important to the chemical processing industry, mining industry, plastics processing industry, as well as lubrication and biomedical flows. The diversity of regulatory parameters like buoyancy rate, magnetic field, mixed convection, absorption, Brownian motion, thermophoretic diffusion, Deborah number, Lewis number, Prandtl number, Soret number, as well as Dufour number contributes significant impact on the current model. The steps of research methodology are as followed: a) conversion from a separate matrix (PDE) to standard divisive calculations (ODEs), b) Final ODEs are solved in bvp4c program, which developed in MATLAB software, c) The stability analysis part also being developed in bvp4c program, to select the most effective solution in the real liquid state. Lastly, the numerical findings are built on a system of tables and diagrams. As a result, the profiles of velocity, temperature, and concentration are depicted due to the regulatory parameters, as mentioned above. In addition, the characteristics of the local Nusselt, coefficient of skin-friction as well as Sherwood numbers on the Maxwell fluid are described in detail.
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Convección , Hidrodinámica , Fricción , Modelos Teóricos , TemperaturaRESUMEN
In this research study, numerical and statistical explorations are accomplished to capture the flow features of the dynamics of ethylene glycol-based hybrid nanofluid flow over an exponentially stretchable sheet with velocity and thermal slip conditions. Physical insight of viscous dissipation, heat absorption and thermal radiation on the flow-field is scrutinized by dissolving the nanoparticles of molybdenum disulfide (MoS2) and graphene into ethylene glycol. The governing mathematical model is transformed into the system of similarity equations by utilizing the apt similarity variables. The numerical solution of resulting similarity equations with associated conditions are obtained employing three-stages Lobatto-IIIa-bvp4c-solver based on a finite difference scheme in MATLAB. The effects of emerging flow parameters on the flow-field are enumerated through various graphical and tabulated results. Additionally, to comprehend the connection between heat transport rate and emerging flow parameters, a quadratic regression approximation analysis on the numerical entities of local Nusselt numbers and skin friction coefficients is accomplished. The findings disclose that the suction and thermal radiation have an adverse influence on the skin friction coefficients and heat transport rate. Further, a slight augmentation in the thermal slip factor causes a considerable variation in the heat transport rate in comparison to the radiation effect.
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The identification and development of radioprotective agents have emerged as a subject matter of research during recent years due to the growing usage of ionizing radiation in different areas of human life. Previous work on synthetic radioprotectors has achieved limited progress because of the numerous issues associated with toxicity. Compounds extracted from plants have the potential to serve as lead candidates for developing ideal radioprotectors due to their low cost, safety, and selectivity. Polyphenols are the most abundant and commonly dispersed group of biologically active molecules possessing a broad range of pharmacological activities. Polyphenols have displayed efficacy for radioprotection during various investigations and can be administered at high doses with lesser toxicity. Detoxification of free radicals, modulating inflammatory responses, DNA repair, stimulation of hematopoietic recovery, and immune functions are the main mechanisms for radiation protection with polyphenols. Epicatechin, epigallocatechin-3-gallate, apigenin, caffeic acid phenylethylester, and silibinin provide cytoprotection together with the suppression of many pro-inflammatory cytokines owing to their free radical scavenging, anti-oxidant, and anti-inflammatory properties. Curcumin, resveratrol, quercetin, gallic acid, and rutin's radioprotective properties are regulated primarily by the direct or indirect decline in cellular stress. Thus, polyphenols may serve as potential candidates for radioprotection in the near future; however, extensive investigations are still required to better understand their protection mechanisms.
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Antineoplásicos/farmacología , Productos Biológicos/farmacología , Neoplasias/prevención & control , Polifenoles/farmacología , Animales , Antineoplásicos/química , Productos Biológicos/química , Humanos , Polifenoles/química , Radiación IonizanteRESUMEN
Nature always remains an inexhaustible source of treasures for mankind. It remains a mystery for every challenge until the completion of the challenge. While we talk about the complicated health issues, nature offers us a great variety of chemical scaffolds and their various moieties packed in the form of natural products e.g., plants, microorganisms (fungi, algae, protozoa), and terrestrial vertebrates and invertebrates. This review article is an update about jaceosidin, a bioactive flavone, from genus Artemisia. This potentially active compound exhibits a variety of pharmacological activities including anti-inflammatory, anti-oxidant, anti-bacterial, antiallergic and anti-cancer activities. The bioactivities and the therapeutic action of jaceosidin, especially the modulation of different cell signaling pathways (ERK1/2, NF-κB, PI3K/Akt and ATM-Chk1/2) which become deregulated in various pathological disorders, have been focused here. The reported data suggest that the bioavailability of this anti-cancer compound should be enhanced by utilizing various chemical, biological and computational techniques. Moreover, it is recommended that researchers and scientists should work on exploring the mode of action of this particular flavone to precede it further as a potent anti-cancer compound.
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Artemisia , Flavonas , Animales , Flavonas/farmacología , Flavonoides , Fosfatidilinositol 3-QuinasasRESUMEN
Capuramycin displays a narrow spectrum of antibacterial activity by targeting bacterial translocase I (MraY). In our program of development of new N-acetylglucosaminephosphotransferase1 (DPAGT1) inhibitors, we have identified that a capuramycin phenoxypiperidinylbenzylamide analogue (CPPB) inhibits DPAGT1 enzyme with an IC50 value of 200 nM. Despite a strong DPAGT1 inhibitory activity, CPPB does not show cytotoxicity against normal cells and a series of cancer cell lines. However, CPPB inhibits migrations of several solid cancers including pancreatic cancers that require high DPAGT1 expression in order for tumor progression. DPAGT1 inhibition by CPPB leads to a reduced expression level of Snail but does not reduce E-cadherin expression level at the IC50 (DPAGT1) concentration. CPPB displays a strong synergistic effect with paclitaxel against growth-inhibitory action of a patient-derived pancreatic adenocarcinoma, PD002: paclitaxel (IC50: 1.25 µM) inhibits growth of PD002 at 0.0024-0.16 µM in combination with 0.10-2.0 µM CPPB (IC50: 35 µM).
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Aminoglicósidos/farmacología , Antineoplásicos/farmacología , Movimiento Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , N-Acetilglucosaminiltransferasas/antagonistas & inhibidores , Neoplasias/patología , Aminoglicósidos/química , Antineoplásicos/química , Línea Celular Tumoral , Sinergismo Farmacológico , Inhibidores Enzimáticos/química , Humanos , Paclitaxel/farmacología , Factores de Transcripción de la Familia Snail/antagonistas & inhibidores , Relación Estructura-ActividadRESUMEN
The Society of Vascular Surgery and the International Society of Cardiovascular Surgery identify three types of acute limb ischaemia to inform prognosis and management. Type 1 limb ischaemia is non-limb-threatening and is currently managed conservatively. We describe three cases of Type 1 limb ischaemia with femoropopliteal occlusion that were managed differently. The first case was initially managed conservatively but resulted in an adverse outcome following worsening of ischaemia. Overall, the cases managed with earlier intervention had good outcomes suggesting that conservative management alone may not be sufficient despite resolution of symptoms. The trend in other vessel diseases such as NSTEMI and TIA is towards earlier intervention, for example, PCI and CEA. It is likely that acute limb ischaemia has a similar natural history to these conditions. It is time to consider earlier revascularisation in selected patients with non-limb-threatening ischaemia.
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Objective. To compare the efficacy and cost-effectiveness of simple nonadherent dressings with other more expensive dressing types in the treatment of venous leg ulcers. Study Design. Retrospective cohort study. Location. The leg ulcer clinic at the University Hospital of South Manchester. Subjects and Methods. The healing rates of twelve leg ulcer patients treated with simple nonadherent dressings (e.g., NA Ultra) were compared with an equal number of patients treated with modern dressings to determine differences in healing rates and cost. Main Outcome Measures. Rate of healing as determined by reduction in ulcer area over a specified period of time and total cost of dressing per patient. Results. Simple nonadherent dressings had a mean healing rate of 0.353 cm(2)/week (standard deviation ± 0.319) compared with a mean of 0.415 cm(2)/week (standard deviation ± 0.383) for more expensive dressings. This resulted in a one-tailed p value of 0.251 and a two-tailed p value of 0.508. Multiple regression analysis gave a significance F of 0.8134. Conclusion. The results indicate that the difference in healing rate between simple and modern dressings is not statistically significant. Therefore, the cost of dressing type should be an important factor influencing dressing selection.
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INTRODUCTION: Anxious patients can cause unexpected increases in healthcare costs that are often overlooked. There are no studies examining the use of an educational pamphlet and its effects on secondary outcomes at colonoscopy. The goal of this study was to determine if the use of an educational pamphlet lowers the anxiety levels before colonoscopy, and if its use has any effect on the quality of the prep or medication or the amount of medication use during the procedure. METHODS: We prospectively enrolled 121 patients having a first-time screening colonoscopy. Patients were blinded and randomized into two groups. One group received standard prep instructions only (group P), and the other group received the American Gastroenterological Association colonoscopy educational pamphlet along with their prep instructions (group I). All information was sent by mail 3 weeks before the procedure. The endoscopists were blinded as to which of their patients were in the study and of those, which were in the standard prep group or the intervention group. Anxiety was measured immediately before endoscopy using the State portion of the 'State Trait Anxiety Index'. Procedure-related information was recorded and analyzed at the end of the study using a statistical package looking at primary and secondary endpoints. RESULTS: Fifteen patients did not show their examination or were otherwise lost to follow-up. Of the 106 patients who completed the study, there were 55 patients in the P group and 51 in the I group. The average State Anxiety score of the P group was 45.18, and of the I group was 40.54 (P=0.014). The use of Midazolam was significantly less in the group. The use of Meperidine was lower in the I group but the difference was not statistically significant. Both the groups took the same amount of time to complete the prep, but the I group fasted longer. The I group also completed or drank more of the prep more often than the P group. The prep quality was found to be superior with less frequency of a poor prep in the I group. Most important, the I group was more likely to have a complete colonoscopy. The I group tended to have fewer questions on the day of the procedure, and less fear about what to expect on the basis of their lower anxiety scores. CONCLUSION: We found that providing the American Gastroenterological Association educational pamphlet to patients before colonoscopy lowers the overall anxiety level, provides a reduction in sedative use during the procedure, and leads to better colon preparation when given in addition to standard instructions.
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Ansiedad/prevención & control , Colonoscopía/psicología , Folletos , Educación del Paciente como Asunto/métodos , Ansiolíticos/uso terapéutico , Ansiedad/diagnóstico , Ansiedad/tratamiento farmacológico , Neoplasias del Colon/diagnóstico , Femenino , Humanos , Masculino , Meperidina/uso terapéutico , Midazolam/uso terapéutico , Persona de Mediana Edad , Narcóticos/uso terapéutico , Estudios Prospectivos , Método Simple Ciego , Resultado del TratamientoRESUMEN
We examined changes in practice patterns after the establishment of a varicose vein center (VVC) within two tertiary university vascular surgery practices and compared differences between urban (U) and rural (R) sites. Practice patterns for the treatment of VVs were compared 3 years before (period 1) and 3 years after (period 2) the formation of a U-VVC and an R-VVC in 2001. Both VVCs were part of similar-sized tertiary vascular surgery practices. Evaluation was specific to VVs, reticular veins, and telangiectasias. Prior to U-VVC, there were 338 office visits, six office procedures, and 114 hospital procedures. After U-VVC, there were 624, 120, and 312, respectively. Prior to R-VVC, there were 85 office visits, five office procedures, and 69 hospital procedures. After R-VVC, there were 528, 163, and 303, respectively. In period 1 for U-VVC and R-VVC, VVC relative value unit (RVU) generation as a percent of total practice RVUs was 1.0% and 0.7%, respectively. In period 2 for U-VVC and R-VVC, VVC RVU generation as a percent of total practice RVUs was 2.6% and 2.5%, respectively. In an effort to provide more coordinated treatment for patients with VVs, establishing a VVC within a tertiary academic vascular surgery practice can lead to rapid expansion of clinical volume by increased office visits, office procedures, and hospital procedures. Clinical demand for evaluation and treatment of VVs showed little variation between R-VVC and U-VVC.
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Hospitales Rurales/estadística & datos numéricos , Hospitales Urbanos/estadística & datos numéricos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Centros Quirúrgicos/estadística & datos numéricos , Várices/cirugía , Procedimientos Quirúrgicos Vasculares/estadística & datos numéricos , Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Hospitales Universitarios/estadística & datos numéricos , Humanos , Illinois , Derivación y Consulta/estadística & datos numéricos , Tennessee , Revisión de Utilización de Recursos , Várices/epidemiologíaRESUMEN
The purpose of this paper is to report the complication of perforation of the superior vena cava (SVC) leading to cardiac tamponade after the insertion of a Trapease IVC filter in the SVC position. A 29-year-old man was hit by motor vehicle and sustained numerous injuries including a left skull fracture, intracerebral hemorrhage, and left open tibial shaft fracture. During his hospitalization, he developed an extensive symptomatic right upper extremity deep venous thrombosis involving the brachial, axillary, subclavian, internal jugular, and brachiocephalic veins. Owing to an intracerebral bleed, anticoagulation was contraindicated. Therefore, a Trapease filter (Cordis Inc.) was placed in the SVC via the left subclavian vein. Four hours later, the patient became hypotensive with associated tachycardia and tachypnea. Computed tomography of his chest revealed a hematoma around the SVC, a moderate amount of fluid within the pericardium, and a moderate-sized right pleural effusion. The patient was taken to the operating room and a pericardial window was performed. Approximately 500 cc of blood was evacuated from the pericardium and immediate improvement in vital signs was noted. The patient was discharged from the hospital 2 weeks later and at 6-month follow-up had made full recovery. This is the first case of SVC perforation leading to cardiac tamponade after the insertion of a Trapease filter. Owing to the rigid structure of the filter and associated motion of the SVC and pericardium, the Trapease filter may be contraindicated in the SVC.
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Taponamiento Cardíaco/etiología , Cateterismo/instrumentación , Extremidad Superior/irrigación sanguínea , Procedimientos Quirúrgicos Vasculares/instrumentación , Filtros de Vena Cava/efectos adversos , Vena Cava Superior/lesiones , Trombosis de la Vena/terapia , Adulto , Humanos , MasculinoRESUMEN
PURPOSE: To determine intraobserver and interobserver variability of carotid arteriography interpretation as well as the reliability of simple visual interpretation (SVI) or "eyeballing" of arteriography in the measurement of internal carotid artery stenoses. METHODS: Intraobserver and interobserver measurements of 200 carotid arteriograms were performed in a blinded fashion by two vascular surgeons (VS1 and VS2) using a digital caliber computer program similar to software available in catheterization laboratories. The distal normal internal carotid artery was used as a frame of reference. These computer-derived measurements were compared with previous SVI measurements, found by retrospective chart review, that were performed at the initial time of arteriography. RESULTS: Intraobserver agreement (VS1a vs VS1b and VS2a vs VS2b) within +/-5% using the computer program was 94% and 92%. Interobserver agreement within +/-5% using the computer program for the four possible combinations ranged from 43% to 48%. Interobserver agreement using the computer program increased to 83% to 88% for correct stenosis interpretation within +/-20%. In the 16% to 49% category (by computer measurement), SVI would have placed the stenosis in a higher category 40% to 56% of the time. Likewise, in the 50% to 79% category, comparing SVI with the four different computer caliber measurements, SVI overestimated the stenosis to the 80% to 99% category by 30% to 44%. In the 80% to 99% category, SVI overestimated lesions in 27% to 51% of the cases. All occlusions seen on SVI correlated with computer program measurements. The computer readings in many cases downgraded the degree of carotid stenosis into a lower category and in some cases, may have led to a different treatment paradigm. SVI never underestimated carotid stenosis compared with all matched computer program measurements. CONCLUSIONS: Compared with a method of objective measurement similar to that used in a catheterization laboratory, SVI overestimated most carotid artery stenoses. Given the coming era of carotid stenting and a renewed need for arteriography before carotid intervention, knowledge of variability and correct interpretation of carotid stenosis using available technology remains paramount to warranted treatment.