1,720,990 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
Hybrid strategies for stand-alone surgical ablation of atrial fibrillation
Full text linkAtrial fibrillation (AF) has been reported as a major cause of cardiac morbidity and mortality, and significantly reduces the quality of life in symptomatic patients. Current guidelines recommend antiarrhythmic drugs and catheter ablation (CA) as first-line therapy. Despite CA showed to be associated with lower incidence of periprocedural complications, rhythm outcomes are far from optimal. Indeed, patients undergoing CA frequently require multiple AF ablation procedures, especially in those with persistent and long-standing persistent AF. While surgical ablation can provide transmural lesions, surgical invasiveness has limited the widespread use of this approach due to the increased perioperative complications. The development of minimally invasive thoracoscopic approaches has renewed the interest towards surgical ablation, thus favoring more simplified ablation sets. Therefore, the concept of "hybrid" ablation has emerged in order to theoretically enhance advantages of both minimally invasive and CA procedures while seeking to improve rhythm outcomes and reduce invasiveness and incidence of perioperative complications. On one hand, it provides the effectiveness of a surgical ablation, on the other, electrical mapping during CA can identify and treat any ablation gap or provide additional ablation lines, thus improving the chance of a stable sinus rhythm restoration at longterm follow-up. Three main thoracoscopic strategies are currently available. All of them can be performed in conjunction with the "catheter ablation procedure": the "Fusion" technique, the bipolar clamp technique, and the most recent "convergent" technique. CA can be performed either simultaneously or with a staged approach after a blanking period in order to allow the ablation lesion to stabilize. Excellent results of the hybrid procedures have been reported in terms of rhythm outcomes and incidence of perioperative complications. This narrative review aims to discuss the rationale behind the concept of hybrid ablation for the treatment of AF regarding different available strategies, results and expert opinions
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
Surgical options for atrial fibrillation treatment during concomitant cardiac procedures
Full text linkCurrent guidelines recommend concomitant surgical ablation (SA) of atrial fibrillation (AF) in the context of mitral valve disease. A variety of energy sources have been tested for SA to perform effective transmural lesions reliably. To date, only radiofrequency and cryothermy energies are considered viable options. The gold standard for SA is the Cox -Maze ablation set, especially for non -paroxysmal AF (nPAF), with the aim of interrupting macro -reentrant drivers perpetuating AF, without hampering the sinus node activation of both atria, and to maintain the atrioventricular synchrony. Although the efficacy of SA in terms of early and late sinus rhythm restoration has been clearly demonstrated over the years, concomitant AF ablation is still underperformed in patients with AF undergoing cardiac surgery. From a surgical standpoint, concerns have been raised about whether a single (left) or double atriotomy would be justified in AF patients undergoing a "non-atriotomy" surgical procedure, such as aortic valve or revascularization surgery. Thus, an array of simplified lesion sets have been described in the last decade, which have unavoidably hampered procedural efficacy, somewhat jeopardizing the standardization process of ablation surgery. As a matter of fact, the term "Maze" has improperly become a generic term for SA. Surgical interventions that do not align with the principles of forming conduction -blocking lesions according to the Maze pattern, cannot be classified as Maze procedures. In this complex scenario, a tailored approach according to the different AF patterns has been proposed: for patients with concomitant nPAF, a biatrial Cox -Maze ablation is recommended. Conversely, it might be reasonable to limit lesions to the left atrium or the pulmonary veins in patients with paroxysmal AF (PAF) in some clinical scenarios. The aim of this review is to provide an overview of the current ablation strategies for patients with AF undergoing concomitant cardiac surgery
Left Atrium Volume Reduction Procedure Concomitant With Cox-Maze Ablation in Patients Undergoing Mitral Valve Surgery: A Meta-Analysis of Clinical and Rhythm Outcomes
Full text linkBackground The management of an enlarged left atrium (LA) in mitral valve (MV) disease with atrial fibrillation (AF) is still being debated. It has been postulated that a reduction in LA size may improve patient outcomes. This meta-analysis aimed to assess rhythm and clinical outcomes of combined surgical AF treatment with or without LA volume reduction (LAVR) in patients undergoing MV surgery.Methods A systematic review was performed and all available literature to May 2022 was included. The primary endpoint was analysis of early and late mortality and rhythm outcomes. Secondary outcomes included early and late cerebrovascular accident (CVA) and permanent pacemaker implantation.Results The search strategy yielded 2,808 potentially relevant articles, and 19 papers were eventually included. The pooled estimated rate of 30-day mortality was 3.76% (95% CI 2.52-5.56). The incidence rate of late mortality and late cardiac-related mortality was 1.75%/year (95% CI 0.63-4.84) and 1.04%/year (95% CI 0.31-3.53), respectively. At subgroup analysis when comparing the surgical procedure with and without AF ablation, the ablation subgroup showed a significantly lower rate of postoperative CVA (p,0.0001) and higher restoration to sinus rhythm at discharge (p=0.0124), with only a trend of lower AF recurrence at 1 year (p=0.0608). At univariable meta-regression, reintervention was significantly associated with higher late mortality (p=0.0033). Conclusion In enlarged LA undergoing MV surgery, LAVR combined with AF ablation showed a trend of improved rhythm outcomes when compared with AF ablation without LAVR. Each LAVR technique has its advantages and disadvantages, which must be managed accordingly
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
- …
