1,720,957 research outputs found
Mitral valve surgery with extensive annular calcification: review of surgical techniques and postoperative complications
No full textMitral annular calcification (MAC) represents an important risk factor in mitral valve (MV) surgery. Despite several procedures having been described, no surgical treatment of choice has been established so far: whether a decalcification should be systematically carried out, or if the MV should be preferentially repaired rather than replaced. A review of the literature on patients undergoing MV surgery associated with MAC was performed. Studies were excluded if dealing with endovascular procedures or emergency surgery for associated endocarditis. Case reports were also not considered in the final analysis. The literature search identified 1429 potentially eligible studies, and 25 papers were eventually included. Several surgical techniques were described to approach this challenging condition. During MV surgery, the presence of MAC favors the occurrence of suboptimal intraoperative outcomes. MAC-related complications such as atrioventricular groove rupture, cerebrovascular accident, new permanent pacemaker implantation, intraoperative conversion from valve repair to replacement and mortality were analyzed. MV surgery in the presence of MAC considerably impacts the postoperative outcomes in terms of morbidity and mortality. A great variability of surgical techniques is reported, suggesting the need for standardization of the approach
Thoracoscopic Surgical Ablation of Lone Atrial Fibrillation: Long-term Outcomes at 7 Years
No full textBackground: Antiarrhythmic drugs and transcatheter ablation in atrial fibrillation (AF) provide suboptimal rhythm control with a not negligible rate of failure in paroxysmal AF (PAF) and nonparoxysmal AF (n-PAF) at midterm and long-term follow-up. This study evaluated the safety profile and long-term efficacy of thoracoscopic ablation in patients with lone AF. Methods: A consecutive 153 patients with lone AF were prospectively enrolled and underwent thoracoscopic surgical ablation. Inclusion criteria were symptomatic AF refractory to pharmacologic therapy (Vaughan-Williams class I-III), age >18 years, and absence of left atrial thrombosis. Exclusion criteria were long-standing AF >5 years, left atrial diameter >55 mm, and contraindication to oral anticoagulation. The "box lesion set" (encircling of pulmonary veins) was always used. Exclusion of the left atrial appendage was performed only in selected cases. The primary study end point was freedom from AF. Secondary end points were overall survival and cumulative incidence function of cardiac event-related death, cerebrovascular accidents, and pacemaker implantation. Results: There was no in-hospital mortality. Early postoperative complications were pacemaker implantation (4/153 [2.6%]), cerebrovascular accident (2/153 [1.3%]) with full recovery of both, and bleeding requiring surgical revision (2/153 [1.3%]). Overall freedom from AF at 7 years was 86% ± 4% (76.9% in n-PAF, 96.1% in PAF). Survival freedom from AF in patients without antiarrhythmic drugs in PAF and n-PAF groups was 79.1% and 52.2%, respectively. Conclusions: Thoracoscopic surgical ablation of lone AF by means of an isolated left atrial box lesion provided an excellent long-term rhythm outcome, even in long-standing persistent AF. The isolated left atrial ablation showed an excellent safety profile with low incidence of pacemaker implantation and postoperative complications
Rhythm outcomes of minimally-invasive off-pump surgical versus catheter ablation in atrial fibrillation: A meta-analysis of reconstructed time-to-event data
Full text linkBACKGROUND: Mid- and long-term rhythm outcomes of catheter ablation (CA) for atrial fibrillation (AF) are reported to be suboptimal. Minimally invasive surgical off-pump ablation (MISOA), including both thoracoscopic and trans-diaphragmatic approaches, has been developed to reduce surgical invasiveness and overcome on-pump surgery drawbacks. We sought to compare the efficacy and safety of MISOA and CA for AF treatment. METHODS: A systematic review and meta-analysis of the literature was performed including studies comparing MISOA and CA. The primary endpoint was survival freedom from AF at follow-up after a 3-month blanking period. Subgroup analysis of the primary endpoint was performed according to the type of surgical incision and hybrid approach. RESULTS: Freedom from AF at 4 years was 52.1% ± 3.2% vs 29.1% ± 3.5%, between MISOA and CA respectively (log-rank p < 0.001; Hazard Ratio: 0.60 [95%Confidence Interval (CI):0.50-0.72], p < 0.001). At landmark analysis, a significant improvement in rhythm outcomes was observed in the MISOA group after the 5th month of follow-up (2 months from the blanking period). The Odds Ratio between MISOA and CA of postoperative cerebrovascular accident incidence and postoperative permanent pacemaker implant (PPM) were 2.00 (95%CI:0.91-4.40, p = 0.084) and 1.55 (95%CI:0.61-3.95, p = 0.358), respectively. The incidence rate ratio of late CVA between MISOA and CA was 0.86 (95%CI:0.28-2.65, p = 0.787), while for late PPM implant was 0.45 (95%CI:0.11-1.78, p = 0.256). CONCLUSIONS: The current meta-analysis suggests that MISOA provides superior rhythm outcomes when compared to CA in terms of sinus rhythm restoration. Despite the rhythm outcome superiority of MISOA, it is associated to higher postoperative complications compared to CA.status: Publishe
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
Heart Transplantation Following Fontan Failure: Long-Term Survival Analysis
Full text linkObjectives: Fontan circulation presents significant challenges for patients with congenital heart disease, often necessitating heart transplantation (HTX) due to deteriorating functionality across multiple organ systems. However, the impact of prior Fontan palliation on HTX outcomes remains poorly understood, with early mortality rates suggesting a heightened risk. The aim of our study is to evaluate the long-term results after heart transplantation in patients with univentricular congenital heart disease previously palliated with Fontan circulation. Methods: A retrospective analysis was conducted on patients who underwent HTX for congenital heart disease. Patients were categorized into two groups based on the pre-HTX circulation pathway: the Failing Fontan Group (FFG) and the Biventricular Congenital Group (BCG). Data were collected from patients between 1987 and 2018. Early and late outcomes, including survival rates, were assessed and critically analyzed. Results: Of the 66 patients, 29 (43%) had a failing Fontan palliation (FFG), and 37 had biventricular congenital diseases (BCG) before heart transplantation. Early mortality (30-day) was not statistically different between the two group. The overall survival rate was 82.6 +/- 13.9% at 1 year, 79.0 +/- 14.9% at 5 years, 67.2 +/- 17.6% at 10 years and 63.2 +/- 18.2 +/- at 15 years for the FFG, and 86.1 +/- 11.4% at 1 year, 79.5 +/- 13.7% at 5 years, 75.7 +/- 14.9% at 10 years, 75.7 +/- 14.9% at 15 years for the BCG, with no statistically significant difference (Mantel Cox p value: 0.69, 0.89, 0.52 and 0.39, respectively). Regarding Cox-regression analysis, the long-term survival rate was not affected either by previous Fontan surgery or by the era of heart transplantation (before vs. after the year 2000). Conclusions: Although heart transplantation after Fontan palliation showed a higher risk in the early post-operative period, the medium- and long-term survival rates are comparable with biventricular circulation patients. Despite the failing Fontan patients being a challenging set of candidates for transplantation, it is a reasonable option in their treatment
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