1,720,985 research outputs found
Modified Bentall operation: the double sewing ring technique
No full textThe Bentall-DeBono operation is the technique of choice for aortic root replacement. As more patients do not accept or have contraindications to lifelong anticoagulation, the biological Bentall operation is a good option for these patients, even though complex reoperations would then be required for bioprosthesis degeneration. We studied a modified technique to simplify the reoperations in patients undergoing biological Bentall procedure. A bioprosthetic valved conduit was obtained creating two separate sewing rings at different levels of the vascular graft. One ring was used to sew the bioprosthesis on the vascular graft. The second ring was used to fix the vascular graft on the native aortic annulus. In case of reoperation, the bioprosthesis could be removed cutting only the suture on the first ring. Then the same ring could be used to fix the new prosthesis. Since 2006, we have performed 12 biological Bentall operations with our modification. The mean age was 63.2 years (range 43-77 years), the mean cardiopulmonary time was 79 ± 12 min and the mean aortic cross-clamping time was 68 ± 10 min. We had no in-hospital mortality; the postoperative period was uneventful in all patients. In our experience this modification seems to be simple and reproducible, without increasing the operative risk and postoperative morbidity. © 2007 European Association for Cardio-Thoracic Surgery
Aortic valve replacement with and without combined coronary bypass grafts in very elderly patients: Early and long-term results
No full textObjective: The number of older patients being referred for aortic valve replacement with or without combined coronary bypass grafting (CABG) is increasing. The aim of this study was to evaluate operative risk factors, early and long-term results of isolated aortic valve and aortic valve replacement combined with CABG in octogenarians and nonagenarians. Methods: In the last 10 years, 285 very elderly patients who underwent aortic valve replacement either alone or in combination with coronary artery bypass grafts were retrospectively studied. The population was divided into two groups; isolated aortic valve replacement was performed in 188 patients (group A) and 97 patients had aortic valve replacement combined with coronary surgery (group B). Results: The overall hospital mortality was 5.3%, without statistical difference between groups. The incidence of low-output syndrome was higher in group B (P = 0.0001). The multivariate analysis for hospital mortality showed that urgency status, ejection fraction (EF) >35%, intra-operative variables such as clamping time, need for intra aortic balloon pump and post-operative variables such as prolonged ventilation, dialysis, post-operative myocardial infarction and re-thoracotomy for bleeding were independent prognostic factors for hospital mortality. The mean follow-up time was 49.03 ± 19 months. Survival at one, three and five years was 97.1 ± 1.8%, 92.2 ± 2.2% and 82.4 ± 3.6% for group A and 97.2 ± 2.0%, 88.4 ± 2.7% and 75.6 ± 3.2% for group B (P = 0.62), respectively. Age, male gender, post-operative myocardial infarction, urgency status, dialysis, low EF, mean aortic gradient were risk factors for the impaired survival. Conclusions: In our experience, a careful pre-operative evaluation has yielded good surgical results even in older patients with different comorbidities. Associated coronary grafts slightly increase the surgical risk. The role of revascularization on long-term morbidity and mortality is still not clear. It is essential to compare the results of percutaneous and trans-apical aortic valve replacement with the literature results of conventional aortic valve replacement with and without CABG before it can be used as an alternative for very older patients. © The Author 2011. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
Myocardial remodeling in patients with severe aortic stenosis is associated with increased oxidative stress.
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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
Acute type A aortic dissection: Significance of multiorgan malperfusion
No full textOBJECTIVES: Acute type A aortic dissection (AAAD) remains one of the most challenging diseases in cardiothoracic surgery, and despite numerous innovations, early mortality still remains high. The aim of this study was to review the Emilia-Romagna experience in the treatment of AAAD and to evaluate the effect of malperfusion on mortality and morbidity. METHODS: We examined data of 502 patients between January 2000 and December 2008, from the Emilia-Romagna Regional Registry of AAAD. The mean age was 62.4 ± 13 years and 66.5% were male. At presentation, various types of malperfusion syndromes (cerebral, cardiac, ileo-femoral, renal, mesenteric and spinal cord) were present in 103 patients (20.5%; malperfusion [MPS] group). Three hundred ninety-nine patients (No-MPS group) did not have pre-operative malperfusion. Arterial access for cardiopulmonary bypass was usually via the femoral artery (81.9%), while the axillary artery was used only in 14.7%. The aortic repair was performed using the 'open technique' in 348 patients (69.3%) and with aortic cross-clamping without circulatory arrest in 154 patients (30.7%). RESULTS: Overall in-hospital mortality was 20.9%: 43.7% in the MPS group vs 15% in the No-MPS group (P = 0.001). The operative technique and the cannulation site did not influence post-operative outcomes. Multivariate regression analysis identified mesenteric (odds ratio [OR] 9.5, confidence interval [CI] 2.4-37.4; P = 0.0012), cardiac malperfusion (OR 3.7, CI 1.7-8.0; P < 0.0001) and shock (OR 2.1, CI 1.2-3.5; P = 0.007) as significant risk factors for in-hospital mortality after surgery for type A dissection. Patients who presented singleorgan malperfusion had a mortality rate of 34.7%, which increased to 61.9% and to 85.7% if two or more than two organ systems were involved, respectively. CONCLUSIONS: The results of the surgical treatment of AAAD are acceptable and mainly influenced by patient's status at presentation. Malperfusion of more organ systems makes the prognosis unfavourable and immediate proximal aortic repair may be sub-optimal. In these situations, alternative management strategies should be considered. © The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
Comparison between off-and on-pump coronary artery bypass grafting: Long-term results of a real-world registry
No full textOBJECTIVES: The aim of this study was to compare 5-year rates of overall death, cardiac-related death, myocardial infarction, repeat revascularization, stroke and new occurrence of postoperative renal failure in a large cohort of patients with coronary disease, treated with on- or off-pump coronary artery bypass grafting (CABG). METHODS: Two propensity score-matched cohorts, each of 560 patients, undergoing isolated surgical coronary revascularization at the regional public and private centres of Emilia-Romagna region (Italy) over the period 1 January 2003 - 31 December 2013, were used to compare long-term outcomes of on-pump CABG (6711 patients) and off-pump CABG (597 patients). RESULTS: The matched on-pump group received significantly more bypass grafts than the matched off-pump group (2.4 ± 1.1 vs 1.6 ± 0.9, P < 0.0001). The on-pump group reported statistically significant lower cardiac-related mortality. There was a trend towards higher overall mortality and the need for repeat revascularization procedures in the off-pump group. No difference was found for myocardial infarction, stroke or new occurrence of postoperative renal failure between groups in the follow-up. The multivariate analysis of significant predictors of mortality in the overall population confirmed that the off-pump revascularization strategy was an independent predictor of death at long-term follow-up. On-pump CABG reported significantly better results in terms of mortality in the subgroups of patients with a depressed left ventricular ejection fraction and in patients with three-vessel disease. CONCLUSIONS: In patients undergoing elective isolated CABG, on-pump strategy conferred a long-term survival advantage compared with off-pump strategy, particularly for patients with more extensive coronary disease. No benefits were found in terms of reduction of postoperative morbidity with the off-pump strategy. On-pump surgery should be the preferred revascularization technique, and off-pump surgery reserved for patients for whom the perioperative risk of cardiopulmonary bypass is greater than the risk of a less complete coronary revascularization. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
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
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