In recent years, as the prevalence of obesity has continued to rise, the under-standing of obesity has led to increasingly profound insights. Bariatric and metabolic surgery has experienced rapid development. The authors discuss key topics including the evolving comprehen-sion of obesity, current status of bariatric surgery, advancements in robotic and single-port bariatric procedures, endoscopic bariatric techniques, as well as novel anti-obesity medication. At present, bariatric and metabolic surgery still faces many unresolved problems and challenges. Understanding the current status and finding the ways to address these challenges, It is of great significance to promote the development of bariatric and metabolic surgery in China.

In recent years, as the prevalence of obesity has continued to rise, the under-standing of obesity has led to increasingly profound insights. Bariatric and metabolic surgery has experienced rapid development. The authors discuss key topics including the evolving comprehen-sion of obesity, current status of bariatric surgery, advancements in robotic and single-port bariatric procedures, endoscopic bariatric techniques, as well as novel anti-obesity medication. At present, bariatric and metabolic surgery still faces many unresolved problems and challenges. Understanding the current status and finding the ways to address these challenges, It is of great significance to promote the development of bariatric and metabolic surgery in China.

Laparoscopic sleeve gastrectomy is the most popularly performed bariatric surgery procedure. However, the incidence of postoperative gastroesophageal reflux disease (GERD) is increased in obesity patients. Obesity patients undergoing bariatric surgery are often accompanied with GERD. The de novo GERD is also common after sleeve gastrectomy. Therefore, GERD is the most common and important long-term complication following sleeve gastrectomy. The author reviews literature and combines own clinical experience to elaborate on the selection of surgical methods for obesity patients with GERD, the prevention of GERD in sleeve gastrectomy, and the management of postoperative GERD.

Single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) is a relatively new bariatric surgery procedure, which is ether as a first stage bariatric procedure or second stage surgery following sleeve gastrectomy, or a revisional procedure for unsatisfied weight loss or weight regain following sleeve gastrectomy. Usually the duodenal-ileal anastomosis in SADI-S procedure is made at 250 cm to 300 cm from ileocecal valve. However, as the whole bowel length is quite different, a fixed measurement of only biliopancreatic limb or common limb could result in either too short or too long absorptive bowel leading to life-threatening nutritional deficiencies on the one hand, or insufficient weight loss on the other. In response to this issue, the author proposes to determine the position of anastomosis based on the ratio of common limb length and total bowel length, in order to achieve satisfactory weight loss and avoid malnutrition complications.

The new technique of single anastomosis duodenal-ileal bypass with sleeve gastrectomy appeared during recent years, which is a modification of biliopancreatic diversion with duodenal switch. The basic principles of this technique are restricted food intake by a sleeve gastrectomy and decreased absorption by the duodenal-ileal anastomosis. The new technique is relatively simple, with less malnutrition, better weight loss and metabolic disorders remission. The principle, surgical technique, results and possible complications are described, and the technique is also compared with existing weight loss operations in this article.

Objective To investigate the related risk factors of hair loss in obese patients after laparoscopic sleeve gastrectomy (LSG).Methods The retrospective case-control study was conducted.The clinical data of 54 obese patients who underwent LSG in the East Hospital of Tongji University between November 2013 and June 2015 were collected.All the patients received LSG,and postoperative hair loss of patients was observed.Factors affecting postoperative severe hair loss were analyzed,including gender,age,preoperative body mass index (BMI),postoperative excess weight loss (EWL),total bilirubin (TBil),albumin (Alb),hemoglobin (Hb),iron,zinc,copper,folic acid,vitamin B12 and vitamin D.Observation indicators:(1) follow-up and postoperative hair loss situations:cases with follow-up,follow-up time,cases with hair loss,severity of hair loss,time of hair loss,treatment of hair loss;(2) univariate analysis affecting severity of hair loss after LSG;(3) multivariate analysis affecting severity of hair loss after LSG.Follow-up using outpatient examination and Wechat was performed to detect the changes of BMI and hair loss up to September 2016.Measurement data with normal distribution were represented as (x)±s and comparison between groups was done by the t test.Comparison of count data was analyzed by the chi-square test.Multivariate analysis was done using the Logistic regression model.Results (1) Follow-up and postoperative hair loss situations:all the 54 patients were followed up for 15 months.Forty-two patients had hair loss,including 21 with slight hair loss,10 with moderate hair loss and 11 with severe hair loss.A proportion of hair loss was 6/11 in male and 36/43 in female.The onset time and end time of hair loss were (3.4± 1.4) months and (9.0± 3.6) months,respectively.Of 42 patients,15 took oral medication (6 with ferrous sulfate,5 with decavitamin and 4 with zinc gluconate oral solution) against hair loss,with no obvious improvement.During the follow-up,42 patients stopped hair loss and gradually grow new hair.(2) Univariate analysis affecting severity of hair loss after LSG:gender,postoperative EWL and folic acid were factors affecting severity of hair loss after LSG (x2 =5.161,t =-5.114,4.266,P＜0.05).(3) Multivariate analysis of affecting severity of hair loss after LSG:postoperative EWL and folic acid were independent factors affecting severity of hair loss after LSG (OR=1.039,0.499,95％ confidence interval:1.011-1.068,0.300-0.802,P＜0.05).A prediction accuracy of severity of hair loss after LSG was 85.2％.Conclusion Postoperative EWL and folic acid are independent factors affecting severity of hair loss after LSG.

Bariatric surgery can cure or alleviate metabolic syndrome,of which the mechanism is unclear,however.Several existing hypotheses including decreased caloric intake following the surgeries,foregut and hindgut hypothesis,serum bile acid and bacterial flora changes cannot completely explain the reasons of improvement of metabolic syndrome by various bariatric surgical procedures.Now the bariatric surgeries available are associated with stomach.The gastric center hypothesis is proposed in this article.There would be some particular cells in the gastric wall to secrete unknown hormones,which would be changed with decrease or deletion of stomach irritaion from food after bariatric surgeries,leading to remission of metabolic diseases.Focusing on the upstream stomach in the research on mechanism of bariatric surgery for metabolic syndrome,the fundamental cause of improvement of metabolic syndrome may be found out.

Objective To assess the influence of laparoscopic sleeve gastrectomy (LSG) on the nutritional status in patients with obesity.Methods From August 2014 to July 2015, 24 obese patients underwent LSG in Dongfang Hospital Affiliated to Tongji University.Weight and nutritional status of these patients were measured pre-operatively and 3, 6, and 12 months after surgery.Results The mean body weight of the 24 obesity patients was (81.94±21.39) kg, (78.83±24.49) kg, (62.67±10.79) kg 3, 6, and 12 months after surgery, respectively, which were significantly lower than the preoperative body weight [(99.02±23.92)kg] (P=0.004).The serum levels of albumin, hemoglobin, and trace elements (including calcium, iron, zinc, magnesium, and copper) showed no significant change after surgery (all P>0.05).Plasma vitamin D[25(OH)D] increased significantly from (13.1±4.1)μg/L preoperatively to (19.8±5.3)μg/L 12 months after surgery (P=0.031).Folic acid was (6.2±3.9)μg/L before LSG and significantly increased to (14.2±9.2) μg/L 3 months later surgery (P=0.009);the folic acid level gradually decreased 6 and 12 months after LSG but was still higher than the preoperative level.Conclusion Vitamin D deficiency is present in obese patients before LSG.After surgery, while the serum albumin and trace elements have no obvious change, the vitamin D and folic acid levels remarkably increase.

Bariatric surgery is one of the most rapid,effective and sustained treatment options for obesity.In recent years,laparoscopic sleeve gastrectomy (LSG) has become increasingly popular due to simple manipulation,maintaining gastrointestinal structures,high safety and significant efficacy.Several published studies have reported an increased rate of gastroesophageal reflux disease (GERD) after the operation,or it can aggravate the preexisting symptoms.The mechanisn of GERD is very complex and controversial.