1,721,045 research outputs found
Current state of alternative access for transcatheter aortic valve implantation
No full textThe transfemoral (TF) route constitutes the undisputed default access for transcatheter aortic valve implantation (TAVI). In patients in whom anatomical constraints preclude a TF approach, several alternative access routes have been used. Transthoracic (transapical and transaortic) access routes show higher mortality and bleeding complication rates than the TF approach, which is attributable to the higher baseline risk of the selected patients and the more invasive nature of these procedures. Alternative transarterial approaches (transaxillary, transcarotid, transinnominate) have demonstrated high technical success rates and a favourable safety profile in selected patients and are particularly valuable in the presence of poor respiratory function or previous cardiothoracic surgery. The transcaval approach is an innovative fully percutaneous approach that allows the introduction of large-bore sheaths and shows promising results in high-risk patients. Diligent procedural planning, appropriate patient selection and the expertise of the Heart Team allow the achievement of an adequate safety and efficacy profile of TAVI performed via alternative access. Future studies incorporating standardised and independent outcome assessment are required to gain further knowledge on the risk/benefit relation pertaining to the specific approaches and improve selection of the appropriate access route for the individual patient
Feasibility and safety of transcaval transcatheter aortic valve implantation: a multicentre European registry
No full textAIMS
A transfemoral transarterial approach is considered the preferable access route for transcatheter aortic valve implantation (TAVI), followed by a transaxillary/subclavian TAVI approach. However, these approaches may not be an option in all patients. This study aimed to report the initial European experience with transfemoral transcaval TAVI.
METHODS AND RESULTS
Data on 50 patients treated by transcaval TAVI in five European centres were collected and analysed according to the Valve Academic Research Consortium (VARC)-2 definitions. The study population had a mean age of 78.7±8.0 years and a high surgical risk profile (median STS risk score 6.1%, interquartile range 3.0-11.2%). Transcaval access was successful in 49 out of 50 patients and device success was obtained in 94% of cases. Closure of the caval-aortic puncture site with a nitinol cardiac occluder was successful in all cases without need for emergent surgery. One patient received additional sealing of the aortic puncture site with a covered stent one day post TAVI due to a gradual haemoglobin drop of 3 g/dL. VARC-2-defined life-threatening bleeding and major vascular complications possibly related to transcaval access were 4% and 10%, respectively. There were no bleeding or vascular complications after discharge. At 30 days, the clinical efficacy endpoint was reached in 88% of patients.
CONCLUSIONS
Transfemoral transcaval access proved to be a feasible and safe TAVI approach for high-risk patients with severe aortic stenosis not suitable for transfemoral or transaxillary/subclavian transarterial access
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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