1,720,958 research outputs found
Minimally Invasive Valve Surgery Has Lower Morbidity in Very Obese Patients Compared to Median Sternotomy Approach
No full textAssess the effect of minimally invasive
valve surgery in obese patients with BMI
≥35 kg/m2 compared to median sternotomy
approach
From January 2003 to February 2013, 73
consecutive patients (24 males, 33%) with
BMI≥35 kg/m2 (38.7± 4.4 kg/m2) underwent
isolated mitral and (or) aortic valve surgery ±
tricuspid valve repair by the means of median
sternotomy (MS) or minimally invasive valve
surgery (MIVS) approach
Outcomes of Video-assisted Minimally Invasive Cardiac Myxoma Resection
No full textBACKGROUND:
Myxomas are the most frequent cardiac tumours. Their diagnosis requires prompt removal. In our centre, for valve surgery we use a minimally invasive approach. Here, we report our experience of cardiac myxoma removal through right lateral mini-thoracotomy (RLMT) with particular focus on its feasibility, efficacy and patient safety.
METHODS:
Between February 2006 and January 2017, 30 consecutive patients (aged 66±12.6years, range 35-83 years) underwent atrial myxoma resection through video-assisted RLMT. Percutaneous venous drainage was performed in all patients and direct cannulation of the ascending aorta was performed in 28 out of 30 (93.3%). The diagnosis of atrial myxoma was confirmed by histology.
RESULTS:
Complete surgical resection was achieved in all patients. The mean cardiopulmonary bypass (CPB) time was 76.5±40.8minutes and average aortic cross-clamping time was 41.5±29.8minutes. No patient suffered postoperative complications. Five patients (16.7%) received a blood transfusion. Mechanical ventilation ranged from 3 to 51hours (median 6hours), intensive care unit (ICU) stay ranged from 1 to 5days (median 1day). Total hospital length of stay (HLOS) was 5.6±2 days. Home discharge rate was 56.7%. No in-hospital mortality was reported. During follow-up (55.6±32.3 months; range 4-132 months), one tumour recurrence was observed. There were three late non-cardiac deaths. Overall survival was 100%, 85.7% and 85.7% at 1, 5 and 10 years, respectively.
CONCLUSIONS:
The use of video-assisted RLMT is an effective and reproducible strategy in all patients requiring expedited surgery for left atrial myxoma, independently of coexisting morbidity such as systemic embolisation or previous surgery. This technique leads to complete tumour resection, prompt recovery, early home discharge and high freedom from both symptoms and tumour recurrence
Sutureless aortic valve replacement for aortic incompetence.
No full textOBJECTIVE:
Sutureless prostheses for surgical aortic valve replacement (AVR) are usually used in degenerative calcified aortic stenosis. Less is known on the application of sutureless prostheses for pure aortic incompetence.
METHODS:
Between 2011 and 2014, 442 patients were operated on with the Perceval aortic sutureless valve implant. We identified 11 patients (10 female, mean age 70.5) who underwent sutureless AVR for pure aortic incompetence (off-label use). Three patients had a left ventricle ejection fraction of 30% or less. Mean logistic EuroSCORE was 15.2 (range 2.2-45.2). In five patients associated mitral procedures (three [60%] repair and two [40%] replacement) were performed. Four procedures were performed through a minimally invasive approach (three right minithoracotomies and one partial sternotomy).
RESULTS:
Mean cardiopulmonary bypass time was 130.2 min and aortic cross clamp time was 82.2 min. Mean implanted prosthesis size was 24.5 ± 1.3 (median 25) mm (insignificant correlation with preoperative aortic valve annulus measurement by transthoracic echocardiography: 21.6 ± 1.5 [median 21] mm, Pearson's r = 0.373, p = 0.259). One patient died on 24th day after AVR associated with aortic arch replacement and hypothermic circulatory arrest (10 years after correction for type A aortic dissection). No residual para- or intravalvular leakage was present on discharge and 12-month follow-up. No migration of the prosthesis occurred.
CONCLUSION:
Sutureless AVR is an option in selected patients with aortic incompetence. Preoperative aortic annulus measurement by echocardiography has poor predictive value for estimation of prosthetic valve size
Accuracy of EuroSCORE II in patients undergoing minimally invasive mitral valve surgery
No full textOBJECTIVES:
EuroSCORE II has been implemented with the view to providing better performance than the previous logistic EuroSCORE. However, until now, no external validations have been carried out in the minimally invasive context. Therefore, we sought to validate the accuracy of EuroSCORE II in a retrospective series of consecutive patients undergoing minimally invasive mitral valve surgery.
METHODS:
Data of 1609 consecutive patients who underwent minimally invasive mitral valve surgery in our institution were retrospectively reviewed. The accuracy of EuroSCORE II was assessed in terms of discrimination and calibration. Discrimination was tested via analysis of the area under the curve of receiver operator characteristic; calibration was achieved by calculating the observed versus expected mortality ratio and the Hosmer-Lemeshow test for test probability; global accuracy was assessed by using Brier's score; results were compared with the previous logistic EuroSCORE version. EuroSCORE II performance was also tested for discrimination of postoperative complications. Discrimination subgroup analysis was carried out for single surgeon results, and for high-risk patients those outliers were defined after boxplot analysis (EuroSCORE II ≥6%).
RESULTS:
EuroSCORE II showed good discrimination power (area under the curve 0.846), and was statistically superior to logistic EuroSCORE (P = 0.01). In terms of calibration, both EuroSCORE II and logistic over-predicted mortality; with regard to adverse events, the discrimination of EuroSCORE II was adequate for acute renal failure, low-output syndrome and increased intensive care unit stay; area under the curve of receiver operating characteristic for high-risk patients with EuroSCORE ≥6% was suboptimal (0.654); single surgeon results did not influence the discrimination of EuroSCORE II.
CONCLUSIONS:
EuroSCORE II showed good discrimination power in our series of minimally invasive mitral valve patients; however, it over-predicted mortality. Individual performance did not influence discrimination. Performance was suboptimal for prediction of complications and for high-risk subgroup in-hospital mortality
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
- …
