1,720,982 research outputs found
Sigmoid resection for diverticular disease – to ligate or to preserve the inferior mesenteric artery? Results of a systematic review and meta-analysis
Aim: In colorectal cancer, ligation of the inferior mesenteric artery (IMA) is a standard surgical approach. In contrast, ligation of the IMA is not mandatory during treatment of diverticular disease. The object of this meta-analysis was to assess if preservation of the IMA reduces the risk of anastomotic leakage. Method: A search was performed up to August 2018 using the following electronic databases: MEDLINE/PubMed, ISI Web of Knowledge and Scopus. The measures of treatment effect utilized risk ratios for dichotomous variables with calculation of the 95% CI. Data analysis was performed using the meta-analysis software Review Manager 5.3. Results: Eight studies met the inclusion criteria and were included in the meta-analysis: two randomized controlled trials (RCTs) and six non-RCTs with 2190 patients (IMA preservation 1353, ligation 837). The rate of anastomotic leakage was higher in the IMA ligation group (6%) than the IMA preservation group (2.4%), but this difference was not statistically significant [risk ratio (RR) 0.59, 95% CI 0.26–1.33, I2 = 55%]. The conversion to laparotomy was significantly lower in the IMA ligation group (5.1%) than in the IMA preservation group (9%) (RR 1.74, 95% CI 1.14–2.65, I2 = 0%). Regarding the other outcomes (anastomotic bleeding, bowel injury and splenic damage), no significant differences between the two techniques were observed. Conclusion: This meta-analysis failed to demonstrate a statistically significant difference in the anastomotic leakage rate when comparing IMA preservation with IMA ligation. Thus, to date there is insufficient evidence to recommend the IMA-preserving technique as mandatory in resection for left-sided colonic diverticular disease
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
New Trends in Acute Management of Colonic Diverticular Bleeding
Colonic diverticular disease is the most common cause of
lower gastrointestinal bleeding. In the past, this condition was usually
managed with urgent colectomy. Recently, the development of endoscopy
and interventional radiology has led to a change in the management
of colonic diverticular bleeding.
The aim of this systematic review is to define the best treatment for
colonic diverticular bleeding.
A systematic bibliographic research was performed on the online
databases for studies (randomized controlled trials [RCTs], observational
trials, case series, and case reports) published between 2005 and
2014, concerning patients admitted with a diagnosis of diverticular
bleeding according to the PRISMA methodology.
The outcomes of interest were: diagnosis of diverticulosis as source
of bleeding; incidence of self-limiting diverticular bleeding; management
of non self-limiting bleeding (endoscopy, angiography, surgery);
and recurrent diverticular bleeding.
Fourteen studies were retrieved for analysis. No RCTs were found.
Eleven non-randomized clinical controlled trials (NRCCTs) were
included in this systematic review. In all studies, the definitive diagnosis
of diverticular bleeding was always made by urgent colonoscopy. The
colonic diverticular bleeding stopped spontaneously in over 80% of the
patients, but a re-bleeding was not rare. Recently, interventional endoscopy
and angiography became the first-line approach, thus relegating
emergency colectomy to patients presenting with hemodynamic
instability or as a second-line treatment after failure or complications
of hemostasis with less invasive treatments.
Colonoscopy is effective to diagnose diverticular bleeding. Nowadays,
interventional endoscopy and angiographic treatment have gained
a leading role and colectomy should only be entertained in case of
failure of the forme
Comparison of computed tomography and magnetic resonance imaging in the discrimination of intraperitoneal and extraperitoneal rectal cancer: Initial experience
OBJECTIVES:
To compare computed tomography (CT) and magnetic resonance imaging (MRI) in evaluation of intraperitoneal/extraperitoneal location of rectal cancers.
METHODS AND MATERIALS:
We assessed the identification of the anterior peritoneal reflection (APR) and the distance from the inferior edge of tumors to the anal verge and from the APR to the anal verge.
RESULTS:
Distances obtained with CT and MRI showed a strong correlation [Spearman's coefficient of rank correlation (rho): 0.995; P<.0001]. Magnetic resonance showed sensitivity of 100% (95% CI: 89.62-100.00%), specificity of 75% (95% CI: 20.34-95.88%), positive predictive value (PPV) of 97.14% (95% CI: 85.03-99.52%), and negative predictive value (NPV) of 100% (95% CI: 30.48-100.00%). CT showed a sensitivity of 100% (95% CI: 89.32-100.00%), specificity of 60% (95% CI: 15.40-93.51%), PPV of 94.29% (95% CI: 80.81-99.13%), and NPV of 100% (95% CI: 30.48-100.00%).
CONCLUSIONS:
CT demonstrated a potential supporting role in the evaluation of rectal cancer, showing a strong correlation with MR
Italian guidelines for the diagnosis and management of colonic diverticulosis and diverticular disease
Colonic diverticulosis and diverticular disease are among the most common gastrointestinal disorders encountered in clinical practice. These Italian guidelines focus on the diagnosis and management of diverticulosis and diverticular disease in the adult population, providing practical and evidence-based recommendations for clinicians. Experts from five Italian scientific societies, constituting a multidisciplinary panel, conducted a comprehensive review of meta-analyses, systematic reviews, randomised controlled trials, and observational studies to formulate 14 PICO questions. The assessment of the quality of the evidence and the formulation of the recommendations were carried out using an adaptation of the GRADE methodology. The guidelines covered the following topics: i) Management of diverticulosis; ii) Symptomatic uncomplicated diverticular disease: diagnosis and treatment; iii) Acute diverticulitis: diagnosis and treatment; iv) Management of diverticular disease complications; v) Prevention of recurrent acute diverticulitis; vi) Interventional management of diverticular disease
Variations on the Author
“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
We 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
We 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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