1,720,958 research outputs found
A modified technique of ureteroplasty for megaureter in children
No full textPurpose: Excisional ureteroplasty carries the risks of jeopardizing the ureteral vasculature and leakage from the suture. The folding techniques are theoretically less prone to these risks, although they have other disadvantages due to the bulky ureter. According to the literature, these 2 approaches have similar complication rates of 4% to 25%, to include stenosis, reflux and leakage. We introduce a modified ureteroplasty technique with the aim of ensuring effective reduction of the ureteral diameter with minor risks to the vasculature. Materials and Methods: A total of 42 consecutive patients underwent ureteroplasty and reimplantation (Cohen 16, Politano-Leadbetter 3, psoas hitch 23) between 1994 and 2004, and were followed for 1 to 9 years. The ureter was opened longitudinally on its less vascularized area. Two parallel longitudinal incisions were made from the luminal side up to the musculature layer, leaving the adventitia untouched. The mucosal aspects lateral to these lines were discarded. The inner layer was closed with a running suture. The adventitial layer was closed with single stitches. Results: No leakage, stenosis or reflux was observed. In 3 ureters persistent dilatation was observed, without obstruction or reflux. Conclusions: Our modification combines some principles of the 2 classic techniques, with the purpose of decreasing the risks and disadvantages of both. We believe that our approach affords better preservation of the ureteral vasculature because the adventitia is preserved untouched, as well as effective caliber reduction so that the bulking problem is avoided. In addition, the technique is associated with a minor risk of leakage. Our results show that this approach is a valid option for megaureter correction in children. Copyright © 2005 by American Urological Association
A Simple technique for removing the nuss bar with one stabilizer: The lateral approach
No full textThe removal of the substernal bar after the Nuss operation is not always an easy and fast maneuver. Only a few different technical solutions have been described. In the original Nuss technique, the patient was lying on dorsal decubitus and rotated on the side during the procedure. The Noguchi technique avoids the rotation of the patient, but requires two incisions and straightening of the bar before pulling it out the thorax. Recently, another technique was proposed, avoiding the need of straightening the bar, but it is feasible only if two operative beds in a large operative room are available. We propose another approach for the removal of the bar: The patient is lying on the lateral decubitus, only one incision is performed, and the bar is pulled out along the thoracic wall. Twenty-one bars were removed by using the present approach without any complications. The advantages of our approach on the previous techniques are the single incision, no need of rotating the patient, straightening the bar, or having two operative beds. Our approach is not feasible when metallic stabilizers have been used on both sides, but in our experience, this was not necessary in order to stabilize the bar. © Mary Ann Liebert, Inc
Absorbable stabilisation of the bar in minimally invasive repair of pectus excavatum
No full textIntroduction: The minimally invasive repair of pectus excavatum has become the preferred technique in most centres. One of the most important technical points for the final result is stabilisation of the bar, usually obtained by one or two metal stabilisers. Recently, long-term absorbable stabilisers have become available (LactoSorb®, Biomet, Jacksonville, FL, USA). Made of poly-L-lactic and polyglycolic acid, they have been introduced with the aim of reducing local discomfort and making removal of the bar easier. Their efficacy for the stabilisation of the bar has not been proved yet. In this paper we compare the surgical outcome in two groups of patients, one treated with metallic and the other with absorbable stabilisers. Material and Methods: A total of 280 patients underwent pectus excavatum repair using a Nuss technique in two centres. In 194 patients (group 1), operated on since 2001, the metallic stabiliser was used. In 86 patients (group 2), operated on since February 2007, the LactoSorb® stabiliser was preferred. We compared both groups in terms of surgical details, local symptoms or complications, and bar instability rate. Results: The surgical technique for the stabilisation of the bar was identical in both groups, but in group 1 the stabiliser was fastened to the bar with a steel wire, while in group 2 polyglycolic sutures were used. No differences in local discomfort or postoperative pain were observed between the groups. The LactoSorb® stabiliser was palpable for at least 6-9 months, and progressively disappeared at 9-12 months. In group 1 we observed 6 local complications. In particular, two patients presented with infection, one of them associated with a skin lesion and opening over the metallic stabiliser (revision of the wound was performed). Another patient developed a thoracic wall haematoma after suffering a trauma over the metallic stabiliser, 13 months after operation. Three patients developed a seroma. In group 2 we observed 3 subcutaneous swellings at the site of the LactoSorb® stabiliser at 6, 8 and 9 months after the operation. We did not observe either skin lesions or infections. In the group with metallic stabiliser, 3 patients (1.5 %) had bar dislocation, while we did not observe bar instability in the group with LactoSorb® stabiliser. Conclusions: LactoSorb® stabiliser is safe and effective for stabilising the bar in pectus surgery. We suggest its routine use as it appears to be less traumatic and could make bar removal easier. © Georg Thieme Verlag KG Stuttgart
Bilateral endoclose approach for the stabilization of the bar in pectus repair
No full textBackground: Mini-invasive repair of pectus excavatum with Nuss technique is the preferred technique in most centers. One of the most important technical points for the final result is the stabilization of the bar, usually obtained by one or more stabilizers and few stitches fixing the bar to some ribs. Our aim is to show how to get the bar more stable by passing bilaterally some stitches around the bar and the ribs close to it. By a right thoracoscopy and a 30-degree optic, we are able to pass the stitches bilaterally by using an Endoclose needle (Covidien Ltd., Hamilton HM, Bermuda). The left hemithorax is visualized from the right side, pushing the optic through the mediastinum following the bar and staying just below it. Materials and Methods: We have operated on 230 patients in two centers. We have used only one stabilizer in more than 90 of the patients. In all patients, we have passed four absorbable stitches on the right side, using an Endoclose needle. In the last 45 cases, we have adopted bilateral fixation of the bar by the Endoclose needle. Results: The maneuver takes only around 10 minutes. We did not have complications related to that maneuver. We did not observe destabilization of the bar in those cases. The overall destabilization rate was 1.3. Conclusions: We suggest this technique to give the bar more stability on both sides. We think the use of a bilateral stabilizer can be avoided. © 2009 Mary Ann Liebert, Inc. 2009
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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