1,721,235 research outputs found
Timing of Perioperative Chemotherapy Does Not Influence Long-Term Outcome of Patients Undergoing Combined Laparoscopic Colorectal and Liver Resection in Selected Upfront Resectable Synchronous Liver Metastases
No full textBackground: The aim of this study was to compare patients undergoing combined colorectal and hepatic surgery with and without neoadjuvant chemotherapy to clarify the prognostic advantage of preoperative oncological treatment in a case-matched analysis using propensity scores and to identify factors predictive of good prognosis in a selected population of Synchronous ColoRectal Liver Metastases (SCRLM). Methods: A total of 73 patients who underwent upfront elective combined surgery without preoperative CT for SCRLM in two European tertiary referral centers were selected and constituted the study group (NoNACT group). The NoNACT group was matched (ratio 1:1) with patients who were operated after chemotherapy with neoadjuvant intent (NACT group, the control group). The matching was achieved based on six covariates representative of patients and disease characteristics. Results: While the characteristics of both colorectal and hepatic procedures were similar, the NoNACT group, as compared to the NACT group, had lower blood loss (200 mL vs. 550 mL). Postoperative stay (9 vs. 12 days) and morbidity rate (24.7% vs. 32.9%) were reduced in the NoNACT compared with the NACT group. Mid- and long-term outcomes were comparable. At multivariable analysis, predictors of long-term outcome were: right colonic neoplasms, RAS mutational status, CRS score ≥3 and the absence of perioperative chemotherapy. Conclusion: Preoperative neoadjuvant chemotherapy in patients with colorectal cancer and synchronous resectable liver metastases does not influence the risk of recurrence in patients with favorable tumor biology, while it was associated with increased intraoperative blood loss and morbidity. There is no strong evidence to recommend upfront chemotherapy in the absence of negative prognostic factors
Laparoscopic Management of Hepatocellular Carcinoma: A Critical Reappraisal
No full textFollowing the introduction of the first laparoscopic liver resection, after similar to 25 years, a critical reappraisal seems to be warranted. Liver resection represents the first choice for curing early hepatocellular carcinoma (HCC) allowing a curative chance also in selected patients with intermediate stage tumors. The criteria for liver resectability by laparoscopy remains the same for open surgery, which is oncological criteria (absence of extrahepatic tumor location; completely resectable R0 resection), anatomic (resectability of involved segment with its own blood surely and biliary drainage; absence of vascular invasion of portal or hepatic veins) and technical (possibility to leave in place a residual volume >= 40%). Anatomic resections being more challenging than wedged resections, were initially performed mainly for lesions located in the left liver (segments 2, 3, and 4) and segments 5 and 6 of the right liver (anterior and lateral hepatic segments). Left lateral segmentectomy seemed most suited for laparoscopic resection because of the thinness of the liver, the possibility of resection without hilar dissection, ease of stapling the left hepatic vein and portal pedicles of segment II and III by mechanical stapling. Conversely, right hepatectomy seemed most difficult and technically challenging to perform. The analysis of literature confirms that minor liver resections for HCC can be safely conducted also in cirrhotic patients and that laparoscopy, when feasible, should be the approach of first choice. As mentioned, there have been several studies that compared the long-term outcomes of laparoscopic hepatectomy (LH) versus open hepatectomy for HCC, even in cirrhotic patients, showing that laparoscopy does not seem to have any impact on the risk of postoperative HCC recurrence. However, further studies seem to be required, especially for long-term oncological results and for major hepatectomy, before LH become a common alternative to open liver surgery. The practice of performing LH (major) is challenging, due to the significant complexity of these interventions
Umbilical Single-Port Sleeve Gastrectomy as a Standardized Procedure: How to Do It? (Video)
No full textLaparoscopic sleeve gastrectomy is the most common bariatric procedure worldwide, commonly performed using laparoscopic multiport. Feasibility and safety of single-port sleeve gastrectomy (SPSG) have been proved. We reported a standardized procedure describing the different steps as a reference for bariatric surgeons.
MATERIALS:
Two news concepts are necessary: "surgical corridor," surgeon working in a small intraperitoneal area is less disturbed by excess abdominal fat and liver hypertrophy; "parietal space" is the area in the abdominal wall through the instruments are introduced, it's important to preserve this. The patient was placed in a seated position and we utilized 2.5-3 cm skin incision in the umbilicus. Single trocar was placed; a flexible camera and double curve grasper are needed to decrease grasper conflict. Dissection of the stomach was obtained by 47 cm Thunderbeat (Olympus-Japan), the sleeve of the stomach was created over a 36F calibrator. A 60-mm roticulating XL staplers were used and beginning 4 cm proximal to the pylorus next to the gastro-pancreatic ligament and heading toward the left side of the gastro-esophageal junction. We utilized a linear staple line using 4 to 7 staples; hemostasis is controlled by bipolar coagulation.
RESULTS:
Specimen was removed easily through the single-site trocar. Parietal defect is easily repaired. Operating time is 41 min. The patient was discharged at day 1 without naso-gastric tube or drainage. No complication.
CONCLUSION:
Umbilical SPSG is nowadays a standardized procedure based on the surgical corridor and the parietal space. This is a safe and reproductive procedure applicable in most patients with massive obesity but necessitate learning curve
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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