Importance The prevalence of obesity and outcomes of bariatric surgery are well established. However, analyses of the surgery impact have not been updated and comprehensively investigated since 2003. Objective Up-to-date, comprehensive data and appropriate meta-analytic techniques were used to examine effectiveness and risks of bariatric surgery. Data Sources Literature searches of Medline, Embase, Scopus, Current Contents, Cochrane Library, and Clinicaltrials.gov between 2003 and 2012 were performed. Study Selection Exclusion criteria included publication of abstracts only, case reports, letters, comments, or reviews; animal studies; languages other than English; duplicate studies; no surgical intervention; and no population of interest. Inclusion criteria were at least one outcome of interest resulting from the studied surgery was reported – comorbidities, mortality, complications, reoperations, or weight loss. Of the 25,060 initially identified articles, 24,023 studies met the exclusion criteria, and 259 met the inclusion criteria. Data Extraction A review protocol was followed throughout. Three reviewers independently reviewed studies, abstracted data, and resolved disagreements by consensus. Studies were evaluated for quality. Results A total of 164 studies were included (37 randomized controlled trials (RCTs) and 127 observational studies). Analyses included 161,756 patients with mean age 45 years and body mass index (BMI) 46 kg/m2. We conducted random-effects and fixed-effect meta-analyses and meta-regression. In RCTs, ≤30 days mortality rate was 0.08% [95%CI, 0.01%–0.24%]; >30 days mortality rate was 0.31% [95%CI, 0.01%–0.75%]. BMI loss at the post-surgery five years was 12–17 kg/m2. The complication rate was 17% [95%CI, 11%–23%], and the reoperation rate was 7% [95%CI, 3%–12%]. Gastric bypass (GB) was more effective in weight loss but associated with more complications. Adjustable gastric banding (AGB) had lower mortality and complication rates; yet, the reoperation rate was higher and weight loss was less substantial than GB. Sleeve gastrectomy appeared to be more effective in weight loss than AGB and comparable to GB. Conclusions Bariatric surgery provides substantial and sustained effects on weight loss and ameliorates obesity-attributable comorbidities in the majority of bariatric patients, although risks of complication, reoperation, and death exist. Death rates were lower than those reported in previous meta-analyses.

Obesity is one of the most important public health conditions worldwide. Bariatric surgery for severe obesity is an effective treatment that results in the improvement and remission of many obesity-related comorbidities, as well as providing sustained weight loss and improvement in quality of life. Contemporary bariatric operations include Roux-en-Y gastric bypass, sleeve gastrectomy, adjustable gastric band and the duodenal switch. The vast majority of these procedures are now performed using laparoscopic technique, the main advantages of which include rapid recovery, the reduction of postoperative pain and the reduction of wound-related complications, compared with open surgery. Contemporary bariatric surgery is now safe, with a mortality of three in 1,000 patients; however, all bariatric operations are associated with their own unique short-term and long-term nutritional and procedural-related complications. Type 2 diabetes mellitus (T2DM) is the most studied metabolic disorder associated with obesity, with data demonstrating that improvement and remission of T2DM in patients with obesity is superior after bariatric surgery compared with conventional medical therapy. Bariatric surgery is now a part of some treatment algorithms for the medical management of patients with T2DM and severe obesity. New, minimally invasive and endoscopic devices for the treatment of obesity have now been approved in the USA, which will expand the treatment options for individuals with obesity.

Bariatric surgery in obese patients is a highly effective method of preventing or resolving type 2 diabetes mellitus (T2DM); however, the remission rate is not the same among different surgical procedures. We compared the effects of 20% weight loss induced by laparoscopic adjustable gastric banding (LAGB) or Roux-en-Y gastric bypass (RYGB) surgery on the metabolic response to a mixed meal, insulin sensitivity, and β cell function in nondiabetic obese adults. The metabolic response to meal ingestion was markedly different after RYGB than after LAGB surgery, manifested by rapid delivery of ingested glucose into the systemic circulation, by an increase in the dynamic insulin secretion rate, and by large, early postprandial increases in plasma glucose, insulin, and glucagon-like peptide-1 concentrations in the RYGB group. However, the improvement in oral glucose tolerance, insulin sensitivity, and overall β cell function after weight loss were not different between surgical groups. Additionally, both surgical procedures resulted in a similar decrease in adipose tissue markers of inflammation. We conclude that marked weight loss itself is primarily responsible for the therapeutic effects of RYGB and LAGB on insulin sensitivity, β cell function, and oral glucose tolerance in nondiabetic obese adults.

Data from studies in animal models indicate that certain lipid metabolites, particularly diacylglycerol, ceramide, and acylcarnitine, disrupt insulin action. We evaluated the relationship between the presence of these metabolites in the liver (assessed by mass spectrometry) and hepatic insulin sensitivity (assessed using a hyperinsulinemic-euglycemic clamp with stable isotope tracer infusion) in 16 obese adults (body mass index, 48 ± 9 kg/m2). There was a negative correlation between insulin-mediated suppression of hepatic glucose production and intrahepatic diacylglycerol (r = −0.609; P =.012), but not with intrahepatic ceramide or acylcarnitine. These data indicate that intrahepatic diacylglycerol is an important mediator of hepatic insulin resistance in obese people with nonalcoholic fatty liver disease.

Introduction: We compared the impact of two-dimensional (2D) versus three-dimensional (3D) visualization on both objective and subjective measures of laparoscopic performance using the validated Fundamentals of Laparoscopic Surgery (FLS) skill set. Subjects and Methods: Thirty-three individuals with varying laparoscopic experience completed three essential drills from the FLS skill set (peg transfer, pattern cutting, and suturing/knot tying) in both 2D and 3D. Participants were randomized to begin all tasks in either 2D or 3D. Time to completion and number of attempts required to achieve proficiency were measured for each task. Errors were also noted. Participants completed questionnaires evaluating their experiences with both visual modalities. Results: Across all tasks, greater speed was achieved in 3D versus 2D: peg transfer, 183.4 versus 245.6 seconds (P < .0001); pattern cutting, 167.7 versus 209.3 seconds (P = .004); and suturing/knot tying, 255.2 versus 329.5 seconds (P = .031). Fewer errors were committed in the peg transfer task in 3D versus 2D (P = .008). Fourteen participants required multiple attempts to achieve proficiency in one or more tasks in 2D, compared with 7 in 3D. Subjective measures of efficiency and accuracy also favored 3D visualization. The advantage of 3D vision persisted independent of participants' level of technical expertise (novice versus intermediate/expert). There were no differences in reported side effects between the two visual modalities. Overall, 87.9% of participants preferred 3D visualization. Conclusions: Three-dimensional vision appears to greatly enhance laparoscopic proficiency based on objective and subjective measures. In our experience, 3D visualization produced no more eye strain, headaches, or other side effects than 2D visualization. Participants overwhelmingly preferred 3D visualization.