1,720,963 research outputs found
Learning Curve and Long-Term Outcomes of Thoracic Endovascular Repair With the Relay Stent-Graft
No full textPurpose: To define the learning curve of a widely employed stent-graft for thoracic endovascular repair (TEVAR) by analyzing procedural variables and their impact on long-term outcomes. Materials and Methods: Standard TEVARs for each major aortic thoracic disease were included excluding procedures using thoracoabdominal, arch fenestrated/branched devices and/or chimneys. The primary outcome was the learning curve analysis using the cumulative sum chart method. The secondary outcomes, presented as early (Q1–Q2) versus latest (Q3–Q4) quartiles of experience, were 30-day major adverse events (MAEs); procedural details (additional maneuvers, operative and fluoroscopy time, and contrast volume); 30-day clinical success; endoleak; aorta-related reintervention; and overall and aorta-related survival. Results: Between November 2005 and September 2021, 220 consecutive TEVAR procedures involving the Relay endograft (Terumo Aortic, Sunrise, FL, USA) were performed and included in the present analysis. The mean follow-up was 4.5 ± 3.9 years. The learning curve was reached after 10 patients. Secondary outcomes improved significantly over experience. Thirty-day MAE occurrence was 14.5% versus 11.8% (p=0.550). Additional maneuvers (p=0.009), access-vessel additional maneuvers (p=0.010), operative time (p=0.004), Relay Plus (p=0.001), and implantation of multiple stent-grafts (p=0.034) were independent risk markers for MAEs. Operative time (125.9 ± 66.7 vs 86.7 ± 48.5 minutes, p<0.001), contrast volume (185.4 ± 112.8 vs 140.5 ± 88.2 mL, p=0.003), and fluoroscopy time (12.4 ± 12.7 vs 8.8 ± 7.5 minutes, p=0.017) decreased significantly. Late endoleak occurrence was 19.5% with a nonsignificant reduction (21.8% vs 17.3%, p=0.395). Fluoroscopy time (hazard ratio [HR]=1.0; 95% confidence interval [CI]=1.0–1.1; p=0.008), contrast volume (HR=1.0; 95% CI=1.0–1.1; p=0.018), and type III aortic arch (HR=3.3; 95% CI=1.7–6.4; p<0.001) were independent risk markers for endoleak. Fluoroscopy time (HR=1.0; 95% CI=1.0–1.1; p=0.032) and type III aortic arch (HR=3.6; 95% CI=1.7–7.4; p=0.001) confirmed their significant association in a multivariable analysis. Conclusion: In a high-volume center with a consistent previous endovascular experience, the Relay graft presented satisfactory long-term results with a short learning curve supporting its reliability. Clinical Impact: The manuscript addresses the understanding of how many TEVAR procedures with a currently implanted device have been required to reach the learning curve for an endovascular skilled center. Our TEVAR experience with the Relay stent-graft (Terumo Aortic) demonstrated that ten implantations were required to achieve the device-related learning curve. The fifteen-year analyzed period showed that intraoperative learning-related variables were associated with long-term clinical outcomes and both improved over time. The Relay stent-graft presented satisfactory long-term results along with a short learning curve in a high-volume endovascular center supporting its ongoing implantation
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
Transcranial Doppler detects micro emboli in patients with asymptomatic carotid stenoses undergoing endarterectomy
No full textObjective: The objective of this study was to assess the primary endpoint defined as the detection of micro-embolic signals (MES) by the use of transcranial Doppler (TCD) in patients with asymptomatic carotid stenosis (≥70%) scheduled for carotid endarterectomy. The secondary endpoint consisted of testing the association of MES with stenosis severity, histopathological, and ultrasound characteristics. Methods: This was a single-center, single-arm, prospective, observational trial. Computed tomography angiography and ultrasound assessment (Geroulakos classification) were mandatory as well as being under best medical therapy. MES number and characteristics were investigated in Holter mode TCD-X device with a standard 1.5 MHz probe. The time points of evaluation were: 24 hours preoperative, 24 hours postoperative, and 30 days postoperative. The histopathological analysis was performed according to the modified American Heart Association classification. One-way analysis of variance tested MES differences over time. Univariable and multivariable logistic regression tested variables potentially associated with MES. Results: A total of 120 patients demonstrated a significant reduction of the mean number of MES (3.35 ± 10.04 and 0.82 ± 2.39; pre- and post-carotid endarterectomy, respectively), becoming undetectable at 30 days (P =.001). Hypoechogenic plaques assessed by ultrasound were a significant risk factor for MES (P =.001). The features of plaque vulnerability, such as hemorrhagic component (P =.011), neovascularization (P =.025), signs of inflammation (P =.027), and rupture of the fibrous cap (P =.002) were predictors of MES. Cap rupture was the only predictor in the multivariate analysis (odds ratio, 5.98; P =.030). The stenosis severity was not associated with MES (P =.95) Conclusions: Patients under best medical therapy had a preoperative embolic activity becoming no more detectable after surgery. Both ultrasound and histologic markers of vulnerability were predictors of MES, and stenosis severity was not associated. TCD gives better insight into the real embolic risk, and future studies should evaluate clinical results coming from its implementation with standard imaging techniques. ClinicalTrial.gov registration number NCT05134493
Improving outcomes of acute invasive Aspergillus rhinosinusitis in patients with hematologic malignancies or aplastic anemia: the role of voriconazole
No full textHealth Related Quality of Life Outcomes and Length of Hospital Stay After Micro-Fragmented Autologous Adipose Tissue Injection in Minor Amputations for Diabetic Foot Ulceration (MiFrAADiF trial): Results From a Randomised Controlled Single Centre Clinical Trial
No full textIntroduction: Diabetic foot ulcer (DFU) is a high prevalence complication of diabetes mellitus that significantly impairs the health related quality of life (HRQoL) of patients and is characterised by a prolonged length of hospital stay (LOS). DFU represents a complex clinical scenario. The prevalence of diabetic foot in the global population is 6.3%. The MiFrAADiF trial demonstrated positive results in terms of the healing of DFUs after the injection of micro-fragmented autologous adipose tissue at the minor amputation stump. The impact of this technique on HRQoL and LOS versus standard care has not yet been determined
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