1,721,093 research outputs found
Novel Dissection Station for Endolaryngeal Microsurgery and Laser Surgery: Development and Dissection Course Experience
No full textObjective: We aimed to develop and validate an ex vivo dissection station for endolaryngeal surgery suitable for different kinds of laryngeal specimen and any type of operating technique (CO2 laser, cold instruments by endoscopic or microscopic techniques). Study Design: Experimental construction and validation of a highly specialized dissection station. Setting: Laboratory and international dissection course. Methods: We designed a lightweight dissection station made of polycarbonate resin approved for use with a CO2 laser. The cylindrical box hosts an articulated laryngeal support. The laryngoscope is positioned on an articulated arm, which is fixed on the construction’s footplate. Validation of the larynx box was performed during an international dissection course on laryngeal surgery held in January 2016. Results: We assessed the suitability of our novel dissection station among specialized laryngologists with a mean experience of 14 years. Feedback from the participants was very positive, with a mean general impression of 9.5 (out of 10 points) and a recommendation score of 9.6 for further use. Its utility in transforming the taught surgical steps into daily practice has been highly recognized, with a score of 9.5. Conclusion: The lightweight and transparent larynx box is suitable for any kind of laryngeal specimen, and any surgical intervention can be taught at reasonable cost. It is safe and suitable for use with CO2 lasers. Validation among experienced surgeons revealed its suitability in the teaching of endolaryngeal microsurgery and laser surgery
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
Epinephrine Use in Endoscopic Ear Surgery: Quantitative Safety Assessment
No full textIntroduction: The management of bleeding in exclusive endoscopic ear surgery (EES) is largely dependent on epinephrine use. However, to date its suitability and safety have not been assessed. The aim of the present study would be to assess the safety profile of topical application and/or local infiltrationof diluted epinephrine during EES regarding the intra- A nd postoperative periods. We hypothesize that epinephrine may be safely used during EES. Methods: Retrospective analysis of 90 EES cases performed at the University Hospital of Modena, Italy. Patient's charts and video recordings of the operations were assessed. Results: Epinephrine was used in all cases for hemostatic purposes as following: (1) diluted epinephrine (1:200,000) injection: Mean 1.2 mL (range: 0-3.5) corresponding to 0.006 mg (range 0-0.018), and (2) topical application (1:1,000) directly in the surgical field: Mean 7 cottonoids (range: 0-18) corresponding to mean 0.56 mg (range: 0-1.44). No major cardiovascular adverse effects were assessed. Only 2 intraoperative hypertensive events were recorded. One sensorineural hearing loss was observed in a case of cholesteatoma involving the stapes; no facial palsy occurred during the study period. Conclusion: The combined use of local injection and topical epinephrine is a safe and effective strategy to control bleeding in exclusive EES, when used within the dilutions and quantities reported in this study
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
Quantification and Comparison of Droplet Formation During Endoscopic and Microscopic Ear Surgery: A Cadaveric Model
Full text linkObjectives: The COVID-19 pandemic and the disproportional spread of the disease among otorhinolaryngologists raised concerns regarding the safety of health care staff. Therefore, a quantitative risk assessment for otologic surgery would be desirable. This study aims to quantitatively compare the risk of perioperative droplet formation between microscopic and endoscopic approaches. Study Design: Experimental research. Setting: Temporal bone laboratory. Methods: The middle ear of whole head specimens was injected with fluorescein (0.2 mg/10 mL) before endoscopic and microscopic epitympanectomy and mastoidectomy. Fluorescent droplet deposition on the surgical table was recorded under ultraviolet light, quantified, and compared among the interventions. Drilling time, droplet proportion, fluorescein intensity, and droplet size were assessed for every procedure. Results: A total of 12 procedures were performed: 4 endoscopic epitympanectomies, 4 microscopic epitympanectomies, and 4 mastoidectomies. The mean (SD) proportion of fluorescein droplets was 0.14‰ (0.10‰) for endoscopic epitympanectomy and 0.64‰ (0.31‰) for microscopic epitympanectomy. During mastoidectomy, the deposition of droplets was 8.77‰ (6.71‰). Statistical comparison based on a mixed effects model revealed a significant increase (0.50‰) in droplet deposition during microscopic epitympanectomy as compared with endoscopic epitympanectomy (95% CI, 0.16‰ to 0.84‰). Conclusions: There is considerable droplet generation during otologic surgery, and this represents a risk for the spread of airborne infectious diseases. The endoscopic technique offers the lowest risk of droplet formation as compared with microscopic approaches, with a significant 4.5-fold reduction of droplets between endoscopic and microscopic epitympanectomy and a 62-fold reduction between endoscopic epitympanectomy and cortical mastoidectomy
An ovine model for exclusive endoscopic ear surgery
No full textIMPORTANCE: With the international spread of exclusive transcanal endoscopic ear surgery, the need for a suitable and affordable surgical training model has grown during the past years. OBJECTIVE: To develop and validate an ex vivo animal model for exclusive endoscopic ear surgery. DESIGN, SETTING, AND ANIMAL MODELS: In an experimental study, we compared ovine and human middle ear anatomy in 4 specimens and assessed the lamb as a model for endoscopic ear surgery. After confirming its suitability, we developed a surgical training program for canaloplasty, myringoplasty, and ossiculoplasty. From March 1 to May 31, 2016, the ex vivo model was tested, assessing the time needed for dissection and complications. Each experience was subjectively validated on a scale from 1 (very poor) to 10 (excellent). MAIN OUTCOMES AND MEASURES: Suitability of the lamb model for training in exclusive endoscopic ear surgery. RESULTS: We assessed the suitability of our novel lamb model on 20 ovine middle ears. All interventions could be performed in a satisfactory manner. The mean (SD) time required to perform canaloplasty was 29.7 (13.2) minutes, for middle ear dissection was 7.7 (2.6) minutes, for myringoplasty was 7.7 (4.3) minutes, and for ossiculoplasty was 10.4 (2.7) minutes. The time required for canaloplasty and tympano-meatal flap elevation during dissection decreased from 46.4 minutes in the first 5 cases to 16.2 minutes in the last 5 cases, representing an absolute difference of 30.2 minutes (95% CI, 22.28-38.12). Subjective ratings revealed excellent values for tissue quality (8.9 points of 10), overall satisfaction (8.3 points), and the learning experience (8.8 points). CONCLUSIONS AND RELEVANCE: The ovine model is suitable for endoscopic ear surgery. We describe a novel, exclusively endoscopic approach in an ex vivo animal model for middle ear surgery. The proposed surgical program leads the trainee step by step through the main otologic procedures and is able to enhance his or her surgical skills
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