1,721,037 research outputs found
Safety and efficacy of ureteroscopic lithotripsy for stone disease in obese patients: a systematic review of the literature
No full textObjective: to look at the role and safety of ureteroscopy for stone management in obese patients.Methods: we searched MEDLINE, PubMed and the Cochrane Library from January 1990 to June 2011 for results of ureteroscopy and stone treatment in obese patients. Inclusion criteria were all English language articles reporting on ureteroscopy in patients with morbid obesity. Data on the outcomes and complications was extracted and a meta-analysis of the results conducted.Results: seven studies with 131 patients (136 renal units) were included. All the studies included obese patients (mean BMI 42.2) treated with flexible URS for urinary calculi. The mode of fragmentation was pulse dye laser, holmium laser, and combined modality including electrohydraulic lithotripsy and basket retrieval in others. The average stone size was (1.37). The stone free rate was 87.5% after completion of treatment with a ranged follow up between 3 months and 3.5 years. The mean operative time was 97.1 minutes (30-275). There was an overall 11.4% complication rate, however, none of the patients needed further monitoring and were treated conservatively. A sub-group analysis of the stones depending on size found the URS has a higher stone free rate in stones <2 cm in size (P = 0.0003). Furthermore, URS has a higher stone free rate when treating ureteric stones compared to renal stones (P = 0.04).Conclusion: retrograde stone treatment using ureteroscopy is a safe and efficient modality for treating obese patients with urinary tract calculi with an increased efficiency with smaller stones less than 2 cm in size.</p
Flexible ureteroscopy and Holmium:YAG laser lithotripsy for stone disease in patients with bleeding diathesis: a systematic review of the literature
Full text linkINTRODUCTION AND OBJECTIVES: The management of urolithiasis in patients on anticoagulants presents a challenge to the endourologist. Due to multiple comorbidities, it may be impossible to safely discontinue the anticoagulant treatment. Other modalities such as shock wave lithotripsy and PCNL are contraindicated in these patients, so ureteroscopic treatment may be the only option. We conducted a systematic review of the literature to look at the safety and efficacy of ureteroscopic management in these patients. METHODS: Systematic review and quantitative meta-analysis was performed using studies identified by a systematic electronic literature search from January 1990 to August 2011. All articles reporting on treatment for stones in patients with a bleeding diathesis using ureteroscopy and a Holmium:YAG laser were included. Two reviewers independently extracted the data from each study. The data was included into a meta-analysis and discussed. RESULTS: Three studies were identified reporting on 70 patients (73 procedures). All patients had stone fragmentation using Holmium laser. The mean stone size was 13.2mm with a range of 5-35mm. The quality of the included studies was modest. Stone free status was achieved in sixty-four patients (87.7%). There were no major complications and only 11% of the patients developed minor complications with only 4% rate of minor bleeding. CONCLUSIONS: Retrograde stone treatment using ureteroscopy and holmium laser lithotripsy can be safely performed in patients with bleeding diathesis with a low complication rate
Assessment of Tissue Damage from Ultrasonic, Pneumatic and Combination Lithotripsy
No full textMentor: Manoj Monga MD (Urologic Surgery)Objective: To conduct a comparative evaluation of ultrasonic, pneumatic, and
dual ultrasonic lithotripsy to predict the safety of probes on urinary tract tissue.
Methods: Lithotriptors (medical device used to breakup kidney stones) tested were the Swiss Lithoclast Ultra (ultrasonic only - US, and ultrasonic-pneumatic combination US+P), and the Gyrus ACMI Cyberwand (dual ultrasonic). Fresh porcine ureters, bladders, and renal pelvis tissues were used for testing. A hands-free set up was used with each probe to vertically apply no pressure, 400 g, or 700 g of pressure for a duration of 3 seconds, 5 seconds or 180 seconds. Repetitive testing of each tissue/pressure/time combination was performed, for a total of 351 trials.
Conclusion: All devices afforded a level of safety at tissue durations typical of
inadvertent intraoperative contact (3-5 seconds), though the Lithoclast US-only
was superior with regard to perforation for all tissue types. Overall, very similar
results were observed between the Lithoclast US+P and Cyberwand.This research was supported by the Undergraduate Research Opportunities Program (UROP).Cui, Yuqing; Sarkissian, Carl; Mohsenian, Kevin; Monga, Manoj. (2011). Assessment of Tissue Damage from Ultrasonic, Pneumatic and Combination Lithotripsy. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/104928
Flexible ureteroscopy and laser lithotripsy for stones >2 cm: a systematic review and meta-analysis
No full textBackground and Purpose:
Urinary stones >2 cm are traditionally managed with percutaneous
nephrolithotomy (PCNL). Recently, flexible ureteroscopy and laser
lithotripsy) (FURSL) has been used to manage them with comparable
results. In a comparative study of renal stones between 2 and 3 cm,
FURSL was reported to need less second-stage procedures and be just as
effective as PCNL. Our purpose was to review the literature for renal
stones >2 cm managed by ureteroscopy and holmium lasertripsy.Materials and Methods:
A systematic review and quantitative meta-analysis was performed using
studies identified by a literature search from 1990s (the first reported
large renal stones treated ureteroscopically) to August 2011. All
English language articles reporting on a minimum of 10 patients treated
with FURSL for renal stones >2 cm were included. Two reviewers
independently extracted the data from each study. The data of studies
with comparable results were included into a meta-analysis.Results:
In nine studies, 445 patients (460 renal units) were reportedly treated
with FURSL. The mean operative time was 82.5 minutes (28–215 min). The
mean stone-free rate was 93.7% (77%–96.7%), with an average of 1.6
procedures per patient. The mean stone size was 2.5 cm. An overall
complication rate was 10.1%. Major complications developed in 21 (5.3%)
patients and minor complications developed in 19 (4.8%) patients. A
subgroup analysis shows that FURSL has a 95.7% stone-free rate with
stones 2–3 cm and 84.6% in those >3 cm (P=0.01), with a minor
complication rate of 14.3% and 15.4%, respectively, and a major
complication rate of 0% and 11.5%, respectively.Conclusion:
In experienced hands, FURSL can successfully treat patients with stones
>2 cm with a high stone-free rate and a low complication rate.
Although the studies are from high-volume experienced centers and may
not be sufficient to alter everyday routine practice, this review has
shown that the efficacy of FURSL allows an alternative to PCNL.</p
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
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