1,721,007 research outputs found
ASO Author Reflections: Hepatopancreatoduodenectomy: Why, When, and How?
No full textHepatopancreatoduodenectomy: Why, When, and How
Organ- and Parenchyma-sparing Pancreatic Surgery
No full textconventional pancreatectomies, such as pancreaticoduodenectomy and distal and total pancreatectomy, result in an important loss of normal pancreatic parenchyma and the nearby organs (spleen, upper digestive tract, and common bile duct). In addition, these procedures involve significant mortality, high morbidity, and long-term disorders, including infections, thromboembolic complications, digestive disorders, pancreatic exocrine insufficiency, and diabetes. Although conventional pancreatectomies are mandatory for malignant tumor, they are an overtreatment for benign tumors as healthy functional pancreatic parenchyma is sacrificed, especially in young patients with long life expectancy. Unfortunately, enucleation is not always advisable in lesions of uncertain histology or those deeply located in the pancreatic gland owing to the risk of a positive surgical margin or injury to the main pancreatic duct, respectively. Since the 1980s, the prospects for pancreatic resection have widened with the development of organ-and parenchyma-sparing pancreatic surgery (OPSPS) for benign or low-grade malignant tumors involving isolated or multiple segments of the pancreas. New operations, such as spleen-preserving distal pancreatectomy, duodenum-sparing pancreas head resection, dorsal pancreatectomy, resection of the ventral or uncinate process of the pancreas, middle-preserving pancreatectomy, and central pancreatectomy (the Dagradi-Serio-Iacono operation), aim to preserve pancreatic exocrine and endocrine function, spare the nearby organs, ensure oncological radicality, and achieve better quality of life after surgery. In fact, according to vascular anatomy and embryological development, the pancreatic gland is divided in four segments and each of these can be resected independently. In experienced hands, OPSPS is technically feasible and can be performed with low mortality. Early morbidity is greater than that achieved using standard resection owing to the high rate of postoperative pancreatic fistula. However, most of these pancreatic leakages are managed conservatively. Furthermore, possible poor short-term outcomes are counterbalanced by the preservation of pancreatic endocrine and exocrine function and the low rate of reoperations for tumor recurrence. Currently, OPSPS can also be performed by laparoscopic or robotic approach achieving better results in term of blood loss, operative time, hospital stay, recovery and scarring. Careful case selection, accurate pre-and intraoperative evaluation of the lesion, and experience in pancreatic surgery are required for optimal results
Totally intrabiliary colorectal liver metastasis mimicking intraductal growth-type cholangiocarcinoma
No full textLetter To The Edito
Debate
No full text: The benefit of resection of liver metastases depends on primary diseases. Neuroendocrine tumors are associated with favorable prognosis after resection of liver metastases. Gastric cancer has worse tumor biology, and resection of gastric liver metastases should be performed in selected patients. A multidisciplinary approach is well established for colorectal liver metastases (CLMs). Resection remains the only curative treatment of CLM. Chemotherapy and molecular-targeted therapy have improved survival in unresectable metastatic colorectal cancer. Understanding of the following two strategies, conversion therapy and two-stage hepatectomy, are important to make this patient group to be candidates for curative-intent surgery
Is Preoperative Endoscopic Biliary Drainage Indicated for Jaundiced Patients with Resectable Pancreatic Cancer?
No full textThe role of preoperative biliary drainage (PBD) in the management of jaundiced patients with resectable pancreatic cancer (RPC) is controversial. Obstructive jaundice determines hepatic dysfunction which can increase the operative risks. Experimental studies demonstrated that PBD could be associated with improved surgical outcomes. However, clinical studies did not confirm these findings.Initial clinical studies conducted with percutaneous approach failed to demonstrate a real advantage for patients undergoing PBD before pancreaticoduodenectomy. Overall morbidity was higher in patients undergoing PBD, because of procedure-related complications. Similar results were obtained with endoscopic PBD. Six meta-analyses have not clarified the role of PBD in the management of patients with malignant jaundice undergoing pancreaticoduodenectomy, because of lack of uniformity among all the studies published. Recently, the results of a large randomized controlled trial indicated that direct surgery should be the best therapeutic strategy for jaundiced patients with RPC.The debate whether jaundiced patients with RPC should undergo PBD continues and the advent of neoadjuvant chemoradiotherapy added some arguments in favor of PBD. The latter is still considered the first step for jaundiced patients when they present with cholangitis, intense pruritus or severe jaundice; surgery cannot be scheduled within 7-10 days from the diagnosis; neoadjuvant chemoradiation is planned, as part of the treatment. While endoscopic PBD is considered the preferred approach, there is still controversy about the type of biliary stent which should be used. Emerging data support the insertion of short (4-6 cm) biliary self-expandable metallic stent, especially if surgery is not immediately planned
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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