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Background: Non-alcoholic steatohepatitis (NASH) is a major cause of liver disease in morbidly obese patients. Clinical predictors of NASH remain elusive, as do molecular mechanisms of pathogenesis.Methods: A series of 35 morbidly obese patients undergoing bariatric surgery had a liver biopsy performed for standard histologic analysis. In addition, RNA was obtained from liver tissue and analyzed for leptin receptor gene expression. Regression analysis was used to correlate clinical variables, including serum leptin levels and hepatic leptin receptor gene expression, with the presence of histologically confirmed NASH.Results: Of the 35 subjects enrolled, 29% had steatosis only, 60% had NASH, and 11% had normal liver histology. Among the clinical variables studied, only diabetes mellitus was an independent predictor of NASH. There was a trend toward lower levels of mRNA encoding the long form of the leptin receptor in hepatic tissue from patients with NASH compared to those with steatosis only.Conclusions: Diabetes mellitus is associated with an increased risk of NASH in obese patients. Downregulation of hepatic leptin receptor may play a role in the pathogenesis of NASH. [ABSTRACT FROM AUTHOR]

Background: The recent initiative for identifying centers of excellence in bariatric surgery calls for documentation of surgical outcomes. The SAGES Outcomes Initiative is a national database introduced in 1999 as a method for surgeons to accumulate and compare their data with summary national data. A bariatric-specific dataset was established later in 2001. The aim of this study was to compare the outcomes of bariatric surgery from the Society of American Gastrointestinal Endoscopic Surgeons' (SAGES) bariatric database with data derived from a national administrative database of academic centers.Methods: Between 2001 and 2004, 24 surgeons with 1,954 patients participated in the SAGES Bariatric Outcome Initiative, and 97 institutions with 42,847 patients participated in the University HealthSystem Consortium (UHC) database. Only 7 of the 24 surgeons participating in the SAGES Bariatric Outcome Initiative submitted more than 50 cases. The main outcome measures included demographics, comorbidities, type of bariatric procedure, operative time, length of hospital stay, short- and long-term complications, mortality, and weight loss.Results: Both datasets were comparable for gender. Roux-en-Y gastric bypass had been performed for 88% of the patients in the SAGES database and 96% of the patients in the UHC database. Associated comorbidities were similar between the two groups except for a higher rate of hyperlipidemia for the patients in the SAGES database. The SAGES database contains more bariatric-specific information such as body mass index, operative time, blood loss, bariatric-specific complications, long-term complications, and weight loss data than the UHC database. According to the available data, no statistically significant differences exist between the two datasets in terms of perioperative complications and mortality.Conclusions: The SAGES Bariatric Outcome Initiative provides valuable bariatric-specific data not currently available in an administrative database that may be useful for benchmarking purposes. However, this database is currently underutilized. [ABSTRACT FROM AUTHOR]

Background: Robotic surgery promises to extend the capabilities of the minimally invasive surgeon. The aim of this study was to examine the feasibility of robotic surgery in the setting of laparoscopic gastric bypass.Methods: The Zeus robotic surgical system was used in 50 laparoscopic gastric bypass procedures. The learning curve was staged to add complexity to the robotic tasks as experience grew. Robotic setup time, robotic operative time, total operative time, and operative outcomes were tracked prospectively.Results: We observed a significant decrease in the robotic setup time. Our robotic learning curve demonstrated decreased operative time, even as more complex tasks were accomplished. Total operative time also decreased significantly over the series. There were no complications in our series that could be attributed to the robotic technique.Conclusions: Robot-assisted laparoscopic Roux-en-Y gastric bypass is safe. The steadiness and extra degrees of freedom of surgical robotic systems may improve the accuracy of laparoscopic tasks. The learning curve for robot-assisted laparoscopic Roux-en-Y gastric bypass is significant but manageable. [ABSTRACT FROM AUTHOR]

Background: Hypercarbia and elevated intraabdominal pressure resulting from carbon dioxide (CO2) pneumoperitoneum can adversely affect respiratory mechanics. This study examined the changes in mechanical ventilation, CO2 homeostasis, and pulmonary gas exchange in morbidly obese patients undergoing a laparoscopic or open gastric bypass (GBP) procedure. Methods: In this study, 58 patients with a body mass index (BMI) of 40 to 60 kg/m2 were randomly allocated to laparoscopic (n = 31) or open (n = 27) GBP. Minute ventilation was adjusted to maintain a low normal arterial partial pressure of CO2 (PaCO2), low normal end-tidal partial pressure of CO2 (ETCO2), and low airway pressure. Respiratory compliance, ETCO2, peak inspiratory pressure (PIP), total exhaled CO2 per minute (VCO2), and pulse oximetry (SO2) were measured at 30-min intervals. The acid–base balance was determined by arterial blood gas analysis at 1-h intervals. The pulmonary gas exchange was evaluated by calculation of the alveolar dead space–to–tidal volume ratio (VDalv/VT) and alveolar–arterial oxygen gradient (PAO2–PaO2). Results: The two groups were similar in age, gender, and BMI. As compared with open GBP, laparoscopic GBP resulted in higher ETCO2, PIP, and VCO2, and a lower respiratory compliance. Arterial blood gas analysis demonstrated higher PaCO2 and lower pH during laparoscopic GBP than during open GBP (p < 0.05). The VDalv/VT ratio and PAO2–PaO2 gradient did not change significantly during laparoscopic GBP. Intraoperative oxygen desaturation (SO2 < 90%) did not develop in any of the patients in either group. Conclusions: Laparoscopic GBP alters intraoperative pulmonary mechanics and acid–base balance but does not significantly affect pulmonary oxygen exchange. Changes in pulmonary mechanics are well tolerated in morbidly obese patients when proper ventilator adjustments are maintained. [ABSTRACT FROM AUTHOR]