39 research outputs found
Role of contrast harmonic-endoscopic ultrasound in pancreatic cystic lesions
none4noIncidental pancreatic cysts (PCs) are frequently encountered in the general population often in asymptomatic patients who undergo imaging tests to investigate unrelated conditions. The detection of a PC poses a significant clinical dilemma, as the differential diagnosis is quite broad ranging from benign to malignant conditions. Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) has been reported to be an accurate tool in the differential diagnosis; however, its sensitivity is suboptimal and false negative results do occur. Contrast harmonic EUS (CH-EUS) was demonstrated to be a useful tool to investigate pancreatic solid lesions to differentiate between benign and malignant ones. In the setting of PCs, CH-EUS could help identify areas of malignant growth inside the cystic cavities. Several studies have reported promising results showing malignant areas in PCs as hyperenhanced lesions. Confirmation of malignancy can then be obtained by FNA, which should be precisely targeted according to the findings of the contrast harmonic study.openSerrani, Marta; Lisotti, Andrea; Caletti, Giancarlo; Fusaroli, PietroSerrani, Marta; Lisotti, Andrea; Caletti, Giancarlo; Fusaroli, Pietr
Safe Endoscopic Removal of a Migrated Esophageal Stent Using a Protection Hood
Abstract Delayed esophageal metallic stent migration after a neo-adjuvant therapy of advanced esophageal cancer is a relatively frequent event, which is sometimes due to tumor response to chemotherapy. Stent migration in the stomach is usually asymptomatic but it can cause potentially life-threatening complications as bowel obstruction or perforation. Most gastric migrations can be managed endoscopically; however endoscopic stent removal could also be a risky procedure due to hemorrhage or esophageal perforation. This case report describes a safe and quick endoscopic method to remove a migrated esophageal metallic stent from the stomach using a protection hood mounted on the tip of the endoscope
Fluid dynamic characterization of a polymeric heart valve prototype (Poli-Valve) tested under continuous and pulsatile flow conditions.
PURPOSE: Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. METHODS: 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the behavior of the valve. RESULTS: Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. CONCLUSIONS: Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.This work was funded by the British Heart Foundation, New Horizons grant NH/11/4/29059.This is the final version of the article. It first appeared from Wichtig Publishing via http://dx.doi.org/10.5301/ijao.500045
A bio-inspired microstructure induced by slow injection moulding of cylindrical block copolymers.
It is well known that block copolymers with cylindrical morphology show alignment with shear, resulting in anisotropic mechanical properties. Here we show that well-ordered bi-directional orientation can be achieved in such materials by slow injection moulding. This results in a microstructure, and anisotropic mechanical properties, similar to many natural tissues, making this method attractive for engineering prosthetic fibrous tissues. An application of particular interest to us is prosthetic polymeric heart valve leaflets, mimicking the shape, microstructure and hence performance of the native valve. Anisotropic layers have been observed for cylinder-forming block copolymers centrally injected into thin circular discs. The skin layers exhibit orientation parallel to the flow direction, whilst the core layer shows perpendicularly oriented domains; the balance of skin to core layers can be controlled by processing parameters such as temperature and injection rate. Heart valve leaflets with a similar layered structure have been prepared by injection moulding. Numerical modelling demonstrates that such complex orientation can be explained and predicted by the balance of shear and extensional flow.This is the author-accepted manuscript. It will be under embargo for 12 months after publication. The final version of this article is published by RSC in Soft Matter and can be found here: http://pubs.rsc.org/en/Content/ArticleLanding/2014/SM/C4SM00884G#!divAbstract
A Newly Developed Tri-Leaflet Polymeric Heart Valve Prosthesis.
The potential of polymeric heart valves (PHV) prostheses is to combine the hemodynamic performances of biological valves with the durability of mechanical valves. The aim of this work is to design and develop a new tri-leaflet prosthetic heart valve (HV) made from styrenic block copolymers. A computational finite element model was implemented to optimize the thickness of the leaflets, to improve PHV mechanical and hydrodynamic performances. Based on the model outcomes, 8 prototypes of the designed valve were produced and tested in vitro under continuous and pulsatile flow conditions, as prescribed by ISO 5840 Standard. A specially designed pulse duplicator allowed testing the PHVs at different flow rates and frequency conditions. All the PHVs met the requirements specified in ISO 5840 Standard in terms of both regurgitation and effective orifice area (EOA), demonstrating their potential as HV prostheses.This work was funded by the British Heart Foundation (New Horizons NH/11/4/29059).This is the final published version. It first appeared at http://www.worldscientific.com/doi/abs/10.1142/S0219519415400096?src=recsys
Fattori associati all'insuccesso della colonscopia
Colonoscopy represents the gold standard in the diagnosis of the colorectal cancer. Nevertheless in a small percentage of cases such procedure may result not diagnostic. To decrease the number of incomplete colonoscopies, it is necessary to be extremely careful not only during the procedure but also during the stage that precedes the exam, teaching the patients the correct use of the preparation. The clinical history of the patient (age, sex, and body index) especially searched for previous pelvic or abdominal surgery together with concomitant pathological processes, can be useful to the endoscopist to select complex cases that require specific caution. A further help can be offered by the use of conscious sedation to reduce patient's discomfort and to facilitate the procedure. Nevertheless there are cases in which every attempt to obtain a diagnostic colonoscopy results vain; for such reason is necessary to consider alternative not invasive procedures like radiological examinations such as computed tomographic colonography or double-contrast barium enema
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Quantifying the Shift Toward Transcatheter Aortic Valve Replacement in Low-Risk Patients: A Meta-Analysis.
BACKGROUND: In recent years, use of transcatheter aortic valve replacement has expanded to include patients at intermediate- and low-risk cohorts. We sought to determine disease prevalence and treatment distribution including transcatheter aortic valve replacement eligibility in low-risk patients across 37 advanced economies. METHODS AND RESULTS: Four systematic searches were conducted across MEDLINE, EMBASE, and the Cochrane database for studies evaluating disease prevalence, severity, decision making, and survival in patients with aortic stenosis. Estimates of disease prevalence and treatment eligibility were calculated using stochastic simulation and population data for the 37 countries comprising the International Monetary Fund's advanced economies index. Fifty-six studies comprising 42 965 patients were included across 5 domains: prevalence, severity, symptom status, treatment modality, and outcome. The pooled prevalence in the general population aged 60 to 74 years and >75 years was 2.8% (95% confidence interval [CI], 1.4%-4.1%) and 13.1% (95% CI, 8.2%-17.9%), respectively-corresponding to an estimated 16.1 million (95% CI, 12.2-20.3) people in 37 advanced economies. Of these, an estimated 3.2 million (95% CI, 2.2-4.4) patients have severe aortic stenosis with 1.9 million (95% CI, 1.3-2.6) eligible for surgical aortic valve replacement. There are ≈485 230 (95% CI, 284 550-66 7350) high-risk/inoperable patients, 152 690 (95% CI, 73 410-263 000) intermediate-risk patients, and 378 890 (95% CI, 205 130-610 210) low-risk patients eligible for transcatheter aortic valve replacement. CONCLUSIONS: With a prevalence of 4.5%, an estimated 16.1 million people aged ≥60 years across 37 advanced economies have aortic stenosis. Of these, there are ≈1.9 million patients eligible for surgical aortic valve replacement and 1.0 million patients eligible for transcatheter aortic valve replacement.British Heart Foundation Translational Award TG/15/4/31891 (Drs De Sciscio, Brubert, and Moggridge) and British Heart Foundation Special Project Grant SP/15/5/31548 (Drs Serrani, Stasiak, and Moggridge)
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Design, Development, Testing at ISO standards and in-vivo feasibility study of a novel Polymeric Heart Valve Prosthesis
Clinically available prosthetic heart valves are life-saving, but imperfect: mechanical valves requiring anticoagulation therapy, whilst bioprosthetic valves have limited durability. Polymer valves offer the prospect of good durability without the need for anticoagulation. We report the design and
development of a polymeric heart valve, its bench-testing at ISO standards, and preliminary extravivo
and in-vivo short-term feasibility.
Prototypes were manufactured by injection moulding of styrenic block copolymers to achieve anisotropic mechanical properties. Design was by finite element stress-strain modelling, which has
been reported previously, combined with feedback from bench and surgery-based testing using various combinations of materials, valve geometry and processing conditions. Bench testing was according to ISO 5840:2015 standards using an in-vitro cardiovascular hydrodynamic testing system
and an accelerated fatigue tester. Bench comparisons were made with a best-in-class bio-prosthesis. Preliminary clinical feasibility evaluations included extra-vivo and short-term (1-24 hours) in-vivo testing in a sheep model. The optimised final prototype met the requirements of ISO standards with hydrodynamic performance equivalent to the best-in-class bioprosthesis. Bench durability of greater than 1.2 billion cycles (30 years equivalent) was achieved (still ongoing). Extra-vivo sequential testing (n=8) allowed refinement of external diameter, 3D shape, a low profile, flexibility, suturability, and testing of compatibility to magnetic resonance imaging and clinical sterilisation. In vivo short-term (1-24 hours) feasibility (n=3) confirmed good suturability, no mechanical failure, no trans-valvular regurgitation, competitive trans-valvular gradients, and good biocompatibility at histopathology.
We have developed and tested at ISO standards a novel prosthetic heart valve featuring competitive bench-based hydrodynamics and durability, well beyond the ISO requirements and comparable to a best-in-class bioprosthesis. In-vivo short-term feasibility testing confirmed preliminary safety, functionality and biocompatibility, supporting progression to a long-term efficacy trial.King's College, Cambridg
Mujeres, violencia doméstica y protección de derechos. Un estudio sobre la accesibilidad a los servicios de atención en la Provincia de Misiones. 16H335
El proyecto se fundamenta en experiencias de investigación, extensión y profesionales.
Toma como tema la violencia de género (s), particularmente la que acontece en el ámbito
denominado doméstico (“puertas adentro de la familia”1). Se circunscribe a este tema en
tanto, las mujeres constituyen un grupo históricamente vulnerable y la violencia de
género en el espacio doméstico es de las más recurrentes en las estadísticas oficiales.
Esta problemática social y su abordaje desde el espacio público, el ámbito jurídico y las
políticas públicas, no es nueva pero su comprensión debe ser ubicada en las
coordenadas de época y espacio. Coordenadas que muestran importantes avances en la
protección de los derechos de las mujeres y las familias como también múltiples acciones
para su atención (desde instituciones públicas y organizaciones sociales que convergen
en su abordaje). Sin embargo, la puesta en acto de las mismas y su efectividad muestran
resultados contradictorios que desfavorecen las posibilidades de acceso y equidad.
Desde la producción de conocimientos se trata de aportar a la comprensión del proceso2
en el cual se inscriben las respuestas al problema y las medidas de protección que las
normas vigentes procuran, ubicando las brechas existentes entre los derechos
formalizados y su efectivización en la vida cotidiana; específicamente en la Provincia de
Misiones
Evaluation of a new slim radial echoendoscope: A better option for an aging population
The radial echoendoscope is still widely used for the investigation of abnormalities in the gastrointestinal wall and for stone detection in the extrahepatic biliary tree. Due to aging patient population, EUS is frequently performed in fragile and elderly individuals. We aimed to compare the maneuverability and image quality of a new thin radial echoendoscope to the current one