1,721,124 research outputs found
Extrahepatic cholangiocarcinoma: clinical features
No full textExtrahepatic cholangiocarcinomas (E-CCAs), are hepatobiliary cancers with features of cholangiocyte differentiations, originating from extrahepatic biliary tree at the bifurcation of the hepatic ducts and also in the distal duct. E-CCAs represent the most common type of cholangiocarcinomas (CCAs) and are characterized by poor overall survival. The principal risk factors for E-CCAs are strictly related to geographic location. Jaundice is the most common physical sign at disease presentation. Other common more non-specific symptoms include hepatomegaly, right upper qudrant mass, weight loss, vomiting, nausea, diarrhoea, malaise and fatigue. Unlike intrahepatic CCA, an incidental asymptomatic presentation occurs in a small percentage of cases. This chapter evaluates the principal clinical features of E-CCAs, briefly discussing its specific risk factors
Composizione e tecnologia delle superfici rosse presenti su ceramiche fenicie da mensa di produzione cartaginese (metà VIII – inizio V secolo a.C.)
No full textStima dei flussi turbolenti con tecnica LES accoppiata a modelli di bilancio di massa ed energia alla superficie
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MAGNETIC RESONANCE (MRI) AND COMPUTED TOMOGRAPHY (CT) FOR CHOLANGIOCARCINOMA
No full textHigh quality cross-sectional Multidetector Computed Tomography and/or Magnetic Resonance Imaging play an important role in diagnosis, localization, and staging and planning of the optimal management of cholangiocarcinoma. Correct imaging helps to localize the tumor to either the intrahepatic, the perihilar or the distal bile ducts, each of which requires different management. It accurately stages the disease, identifying the presence of significant nodal and distant metastasis or major vascular encasement of the portal vein or the hepatic arteries, or depicts extensive involvement of the hepatic duct reaching up to second-order biliary radicals. It also helps to identify the extent of local tumor invasion, which has a major impact on management.
This chapter presents the spectrum of appearances of cholangiocarcinomas at cross-sectional imaging and examines the possibilities of imaging modalities in the proper stage classification of bile duct tumors according to the recent staging systems
YTTRIUM-90 MICROSPHERE RADIOEMBOLIZATION FOR UNRESECTABLE CHOLANGIOCARCINOMA
No full textThe term radioembolization defines those procedures in which intra-arterially injected radioactive microspheres are used for internal radiation purposes. The aim of this procedure is to selectively target radiation to liver tumors and to limit the dose to the normal liver parenchyma. The yttrium-90 microspheres delivered through the hepatic artery are implanted into liver tumors in a ratio ranging from 3:1 to 20:1 as compared to a normal liver parenchyma. The principles of radioembolization are fundamentally different from the conventional embolization of liver cancer through transarterial embolization or chemoembolization. A work-up, involving computed tomography scanning, contrast-enhanced magnetic resonance imaging and hepatic angiography, is essential for assessing the appropriateness of the patient for yttrium-90 treatment. A simulation of the procedure, carried out with technetium-99m-labeled macroaggregated albumin particles which approximate the size of the microspheres, is used to identify the shunting of microparticles to the lungs or the gastrointestinal tract, thus helping in patient selection.
Excellent periprocedural care, discharge planning and follow-up are essential in assessing treatment response and ensuring that the short-term side effects of radioembolization are adequately managed.
In the management of hepatocellular carcinoma and metastatic tumors, the ever increasing literature regarding radioembolization shows that this is an effective treatment, improving survival with a low incidence of side effects. In bile duct tumors, radioembolization can only be used as a palliative treatment for intrahepatic cholangiocarcinoma; some recent studies have reported good safety and efficacy rates and low complication rates, with median survival ranging from 9 to 22 month
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
STAGING OF CHOLANGIOCARCINOMA
No full textMultidetector Computed Tomography (MDCT) and/or Magnetic Resonance Imaging (MRI) accurately stage Cholangiocarcinoma (CCA), identifying the presence of nodal and distant metastasis or major vascular encasement of the portal vein or the hepatic arteries, or depicts extensive involvement of the hepatic duct reaching up to second-order biliary radicals. They also help to identify the extent of local tumor invasion, which has a major impact on management. Moreover, imaging helps to identify any anatomical variations in the hepatic arterial or venous circulation and the biliary ductal system, which is of vital importance in surgical planning. This chapter examines the possibilities of imaging modalities in allocating the different types of CCAs in the proper stage, according to the latest staging systems
PERCUTANEOUS TRANSHEPATIC CHOLANGIOGRAPHY (PTC) FOR CHOLANGIOCARCINOMA
No full textAfter percutaneous transhepatic cholangiography (PTC), current percutaneous biliary interventions to manage malignant obstruction include biliary drainage (PTBD) and metallic and plastic internal stent insertion. PTC allows the direct opacification of the biliary system and is regarded as the most accurate preoperative diagnostic modality for assessing the longitudinal extension of hilar cholangiocarcinoma (CCA) compared with endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP). After ultrasound (US) and subsequent computed tomography (MDCT) and/or magnetic resonance imaging (MRI), many diagnostic algorithms propose direct cholangiography using endoscopic retrograde cholangiopancreatography (ERCP) or its percutaneous counterpart transhepatic cholangiography (PTC) associated with brush cytology and forceps biopsy for diagnostic confirmation. In most centres, ERCP has largely replaced PTC for diagnostic purposes, and endoscopic stenting is the first-line of therapy. The percutaneous approach is usually employed when the endoscopic approach has either failed or is not possible, as in patients with a history of partial gastrectomy, gastric outlet obstruction or biliary-enteric bypass. The choice between the two approaches mainly depends on proximal or distal tumour location. Patients with hilar strictures are best treated percutaneously, as endoscopic drainage has higher failure and complication rates in this situation. The percutaneous approach can also be used to position biliary drainage (PTBD) for temporary biliary decompression prior to definitive surgery. Preoperative biliary drainage is indicated in patients with cholangitis, long-standing jaundice or poor nutrition, and in surgical candidates in whom liver volume is <40% of total liver volume. Major hepatectomy combined with preoperative PTBD followed by portal vein embolization is a safe management strategy for resectable perihilar CCA.
For palliation of malignant obstructive jaundice, PTBD and stenting is a safe and effective technique and is equally successful in the treatment of distal and proximal bile obstruction. In the percutaneous approach, metal self-expandable stents have proved superior to plastic stents and should be preferred. Technical success is >90% and clinical success is >75% in all major series. The vast majority of complications can be treated conservatively and the procedure-related mortality is <2% in most series. About 10–30% of patients will have recurrent jaundice after PTBD or stenting and require re-intervention. Endoscopic stent placement is commonly preferred as the primary tool in distal bile duct strictures and the percutaneous approach is mostly reserved for cases where ERCP fails or is not possible. Patients with hilar strictures involving the right or left hepatic duct (or both) are best treated by percutaneous placement of metallic stents. Intraductal brachytherapy and radiofrequency ablation can be further tools whose efficacy is still under evaluation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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