1,720,969 research outputs found
Thoracic stent graft versus surgery for thoracic aneurysm
No full textThoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery. The aim of this review is to assess the efficacy of TEVAR versus conventional open surgery in patients with TAAs. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched March 2013) and CENTRAL (2013, Issue 2). Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair. Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified. We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms. Though stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay, high quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed
Laparoscopic versus open surgery in small bowel obstruction
No full textBACKGROUND: Acute intestinal obstruction is one of the most common surgical emergencies. The small bowel obstruction (SBO) is the site of obstruction in most patients (76%) and adhesions are the most common etiology (65%). Laparoscopy in SBO has no clear role yet as it may have a therapeutic and diagnostic function. In some settings laparoscopic or laparoscopy-assisted surgery is considered feasible and convenient more than conventional surgery for SBO; however little is known if laparoscopic or laparoscopy-assisted surgery is more suitable with respect to open surgery for patients with SBO.
OBJECTIVES: The aim of this systematic review is to assess whether laparoscopic or laparoscopy-assisted surgery is feasible and safe for acute SBO, and whether laparoscopic and laparoscopy-assisted surgery present advantages compared to open surgery in terms of short-term and long-term outcomes.
SEARCH STRATEGY: We searched for published randomised and prospective controlled clinical trials without language restrictions using the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950 onwards) and EMBASE (1980 onwards).
SELECTION CRITERIA: Randomised controlled trials and non randomised controlled prospective trials evaluating laparoscopic and laparoscopy-assisted surgery versus traditional open surgery for acute SBO were considered.
DATA COLLECTION AND ANALYSIS: We conducted the review according to the recommendations of The Cochrane Collaboration and the Cochrane Colorectal Group as well, using Review Manager 5 to conduct the review.
MAIN RESULTS: No published or unpublished randomised controlled trials or prospective controlled clinical trials comparing laparoscopy with open surgery for patients with SBO were identified.
AUTHORS' CONCLUSIONS: Although data from retrospective clinical controlled trials suggest that laparoscopy seems feasible and better in terms of hospital stay and mortality reduction, high quality randomised controlled trials assessing all clinically relevant outcomes including overall mortality, morbidity, hospital stay and conversion are needed
Covering ileo- or colostomy in anterior resection for rectal carcinoma
No full textBACKGROUND:
Anastomotic leakage is one of the most important complications that occur after surgical low anterior resection for rectal cancer. There are indications that anastomotic leak is associated with increased morbidity, mortality, frequent re-operation or radiological drainage, and prolonged hospital stay. Defunctioning stoma can be useful for patients undergoing a rectal surgery.
OBJECTIVES:
To determine the efficacy of protective defunctioning stoma in low anterior resection for rectal carcinoma.
SEARCH STRATEGY:
Searches were conducted November 2009. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1966) and EMBASE (from 1980).
SELECTION CRITERIA:
We included randomised clinical trials comparing the use of stoma versus "no stoma" in patients that received low anterior resection for rectal cancer.
DATA COLLECTION AND ANALYSIS:
Six randomised controlled trials were identified and included in this review. Five trials were fully published in peer-reviewed journals. An attempt was made to obtain further information from the authors of the trial that was available only in an abstract form. The studies analysed the following outcomes: clinical anastomotic leakage, urgent reoperation, mortality and length of postoperative hospital stay. Review authors extracted the data independently, the risk ratios (RR) were estimated for the dichotomous outcomes and standardised mean difference were estimated for the continuous outcome
MAIN RESULTS:
All the trials reported results for clinical anastomotic leakage, urgent reoperation and mortality. Only two trials reported the results for length of postoperative hospital stay.With respect to controls, use of covering stoma was significantly associated with less anastomotic leakage (RR 0.33; 95%CI [0.21, 0.53]) and less urgent reoperation (RR 0.23; 95%CI [0.12, 0.42] ). There was no significant difference in terms of mortality (RR 0.58; 95%CI [0.14, 2.33]). There was no evidence of statistical heterogeneity in any of the comparisons.
AUTHORS' CONCLUSIONS:
Covering stoma seems to be useful to prevent anastomotic leakage and urgent re-operations in patients receiving low anterior resection for rectal cancer. However, covering stoma does not seems to offer advantage in term of 30 days or long term mortality
Damage control surgery for abdominal trauma
No full textBACKGROUND: Trauma is one of the leading causes of death in any age group. The 'lethal triad' of acidosis, hypothermia, and coagulopathy has been recognized as a significant cause of death in patients with traumatic injuries. In order to prevent the lethal triad two factors are essential, early control of bleeding and prevention of further heat loss. In patients with major abdominal trauma, damage control surgery (DCS) avoids extensive procedures on unstable patients, stabilizes potentially fatal problems at initial operation, and applies staged surgery after successful initial resuscitation. It is not currently known whether DCS is superior to immediate surgery for patients with major abdominal trauma.
OBJECTIVES: To assess the effects of damage control surgery compared to traditional immediate definitive surgical treatment for patients with major abdominal trauma.
SEARCH METHODS: We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2012, Issue 12 of 12), MEDLINE, EMBASE, Web of Science: Science Citation Index & ISI Proceedings, Current Controlled Trials MetaRegister, Clinicaltrials.gov, Zetoc, and CINAHL for all published and unpublished randomised controlled trials. We did not restrict the searches by language, date, or publication status. The search was through December 2012.
SELECTION CRITERIA: Randomised controlled trials of damage control surgery versus immediate traditional surgical repair were included in this review. We included patients with major abdominal trauma (Abbreviated Injury Scale > 3) who were undergoing surgery. Patient selection was crucial as patients with relatively simple abdominal injuries should not undergo unnecessary procedures.
DATA COLLECTION AND ANALYSIS: Two authors independently evaluated the search results.
MAIN RESULTS: A total of 2551 studies were identified by our search. No randomised controlled trials comparing DCS with immediate and definitive repair in patients with major abdominal trauma were found. A total of 2551 studies were excluded because they were not relevant to the review topic and two studies were excluded with reasons after examining the full-text.
AUTHORS' CONCLUSIONS: Evidence that supports the efficacy of damage control surgery with respect to traditional laparotomy in patients with major abdominal trauma is limited
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
Radiofrequency ablation in the treatment of liver metastases from colorectal cancer.
No full textBACKGROUND:
Colorectal cancer (CRC) is the most common malignant tumour and the third leading cause of cancer deaths in USA. For advanced CRC, the liver is the first site of metastatic disease; approximately 50 % of patients with CRC will develop liver metastases either synchronously or metachronously within 2 years after primary diagnosis. Hepatic resection (HR) is the only curative option, but only 15-20% of patients with liver metastases from CRC (CRLMs) are suitable for surgical standard treatment. In patients with unresectable CRLMs downsizing chemotherapy can improve resectability (16%). Modern systemic chemotherapy represents the only significant treatment for unresectable CRLMs. However several loco-regional treatments have been developed: hepatic arterial infusion (HAI), cryosurgical ablation (CSA), radiofrequency ablation (RFA), microwave ablation and selective internal radion treatment (SIRT). During the past decade RFA has superseded other ablative therapies, due to its low morbidity, mortality, safety and patient acceptability.
OBJECTIVES:
The objective of this study was to systematically review the role of radiofrequency ablation (RFA) in the treatment of CRLMs.
SEARCH METHODS:
We performed electronic searches in the following databases:CENTRAL, MEDLINE and EMBASE. Current trials were identified through the Internet using the Clinical-Trials.gov site (to January 2, 2012) and ASCO Proceedings. The reference lists of identified trials were reviewed for additional studies.
SELECTION CRITERIA:
Randomized clinical trials (RCTs), quasi-randomised or controlled clinical trials (CCTs) comparing RFA to any other therapy for CRLMs were included. Observational study designs including comparative cohort studies comparing RFA to another intervention, single arm cohort studies or case control studies have been included if they have: prospectively collected data, ten or more patients; and have a mean or median follow-up time of 24 months. Patients with CRLMs who have no contraindications for RFA. Patients with unresectable extra-hepatic disease were also included.Trials have been considered regardless of language of origin.
DATA COLLECTION AND ANALYSIS:
A total of 1144 records were identified through the above electronic searching. We included 18 studies: 10 observational studies, 7 Clinical Controlled Trials (CCTs) and an additional 1 Randomized Clinical Trial (RCT) (abstract) identified by hand searching in the 2010 ASCO Annual Meeting. The most appropriate way of summarizing time-to-event data is to use methods of survival analysis and express the intervention effect as a hazard ratio. In the included studies these outcome are mostly reported as dichotomous data so we should have asked authors research data for each participant and perform Individual Patient Data (IPD) meta-analysis. Given the study design and low quality of included studies we decided to give up and not to summarize these data.
MAIN RESULTS:
Seventeen studies were not randomised and this increases the potential for selection bias. In addition, there was imbalance in the baseline characteristics of the participants included in all studies. All studies were classified as having a elevate risk of bias. The assessment of methodological quality of all non-randomized studies included in meta-analysis performed by the STROBE checklist has allowed us to identify several methodological limits in most of the analysed studies. At present, the information from the single RCT included (Ruers 2010) comes from an abstract of 2010 ASCO Annual Meeting where the allocation concealment was not reported; however in original protocol allocation concealment was adequately reported (EORTC 40004 protocol). The heterogeneity regarding interventions, comparisons and outcomes rendered the data not suitable.
AUTHORS' CONCLUSIONS:
This systematic review gathers information from several controlled clinical trials and observational studies which are vulnerable to different types of bias. The imbalance between characteristics of patients in the allocated groups appears to be the main concern. Only one randomised clinical trial (published as an abstract), comparing 60 patients receiving RFA plus CT versus 59 patients receiving CT alone, was identified. This study showed that PFS was significantly higher in the group that received RFA. However, it was not able to provide information on overall survival. In conclusion, evidence from the included studies are insufficient to recommend RFA for a radical oncological treatment of CRLMs
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
- …
