A, the treatment of pathological obesity combined with diabetes surgery: 1, Roux – en – Y gastric bypass (Roux – en – Y gastric bypass, GBP): after separating the gastric body, in the middle of the stomach to close the distal end of the stomach and the proximal gastric less curved side; in Trietz’s ligament 50 cm below the separation, cut off the jejunal collaterals, the distal jejunum and the proximal gastric greater curved side anastomosis; proximal jejunum The proximal jejunum was anastomosed to the jejunal wall 50-150 cm distal to the gastrojejunal anastomosis to complete the Roux-en-Y gastric diversion. The operative mortality rate is 0% to 1.5%, and the main complications are anastomotic leak, pulmonary embolism and intestinal obstruction, with an incidence of 0.6% to 6%. Billiopancreatic diversion (BPD): After the stomach is cut, the jejunum is separated and cut at about 50 cm below Trietz’s ligament, and the distal jejunum is anastomosed with the proximal stomach; the proximal jejunum is anastomosed at 50 cm-100 cm from the ileocecal valve, and the biliopancreatic fluid is diverted to the distal ileum to reduce the absorption of nutrients. The operative mortality rate is 0.5%. Gastroplasty includes gastric banding and vertical banded gastroplasty, in which the volume of the stomach is reduced by circumferential banding of the stomach and longitudinal suturing of the stomach, respectively, without causing changes in the physiological passage of food. The surgical effect: GBP>BPD>Gastroplasty Second, the current surgical methods used in animal models 1, gastrojejunal bypass group (Gastrojejunal bypass): gastroduodenal dissection, closing the duodenal stump, 3 cm distal to the Treitz ligament to cut off the jejunum. Gastrojejunal anastomosis was performed on the distal intestinal collaterals, and the proximal intestinal collaterals were anastomosed with the jejunum 4 cm from the anastomosis, leaving the entire duodenum and proximal jejunum open. 2.Jejuno-ileal bypass: Gastro-duodenal dissection, closing the duodenal stump, and cutting off the jejunum at 3 cm distal to the Treitz ligament. The end of jejunum was transected and then the proximal segment was anastomosed with the end of ileum and most of the ileum was left open. The efficacy and safety of GBP surgery for the treatment of diabetes mellitus GBP surgery is the most popular surgery for the treatment of type 2 diabetes mellitus. There are more studies on this procedure. Pories et al. reported 1254 obese patients who underwent GBP surgery, of whom 83% had combined diabetes and 99% had combined impaired glucose tolerance after a maximum of 8 years of follow-up. In a 2003 study from the University of Pittsburgh, 19l patients with type 2 diabetes underwent laparoscopic GBP and were followed up for 5 years. MacDonald et al. reported that 154 of 232 obese patients with combined diabetes underwent GBP as the study group and 78 did not undergo the procedure as the control group: the proportion of patients taking hypoglycemic drugs after 9 years (median follow-up time) in the study group decreased from 31.8% before surgery to 8.6%. The proportion of patients taking glucose-lowering drugs after 9 years (median follow-up time) in the study group decreased from 31.8% before surgery to 8.6%, and the morbidity and mortality rate was 9%; while the proportion of patients taking glucose-lowering drugs after 6 years (mean median follow-up time) in the control group increased from 56.4% before surgery to 87.5%. A Meta-analysis conducted by Buchwald et al. The results of 361 (85,048 patients) clinical studies of diabetes surgery were collected. The cure rate of type 2 diabetes mellitus treated by GBP surgery was 83.7%. In China, Wang Yu et al. started to use open GBP surgery to treat type 2 diabetes in 2004. By 2008, 113 cases were performed. The cure rate of diabetes mellitus after surgery is over 95%. Patient selection and surgical indications: In 1991, the National Institutes of Health first established the criteria for surgical bariatric surgery [1], and the widely recognized surgical indications in Europe and the United States include: (1) BM I ≥ 40 or BM I ≥ 35 and the presence of some obesity-related co-morbidities; (2) exclusion of mental and behavioral abnormalities that affect the therapeutic effect; (3) no absolute contraindications to abdominal surgery; (4) conservative (5) exclude secondary obesity caused by endocrine disorders of anterior pituitary, thyroid and adrenal cortical function. In China, based on the reference of European, American and Asian-Pacific surgical standards for weight reduction surgery, combined with the physical characteristics and developmental features of Chinese people and the experience of surgical treatment of obesity, the selection and surgical indications for obese patients in China were proposed, and the obesity-related concomitant diseases were included in the surgical indications, which were internationally recognized and released in October 2007 with the first domestic guidelines for surgical treatment of obesity. The Endocrine Surgery Group of the Chinese Society of Medical Surgery has classified obesity-related co-morbidities as an important indication for surgical treatment of obesity, and at the same time set up efficacy assessment criteria focusing on the degree of improvement of co-morbidities: (1) the presence of obesity-related metabolic disorders is confirmed, and weight loss is predicted to be effective for treatment; (2) waist circumference: ≥90cm for men and ≥80cm for women; (3) more than 5 consecutive years (3) stable or stable weight gain, BMI ≥32kg/m2; (4) 16-65 years of age; (5) medical treatment for more than one course of treatment is not effective or can not tolerate conservative treatment; (6) no alcohol or drug dependence and serious mental and intellectual disabilities; (7) patients understand the procedure of bariatric surgery, and understand and accept the risk of potential complications of surgery, understand the postoperative lifestyle, dietary habits change The patients understood the importance of postoperative recovery and had the ability to tolerate it, and could actively cooperate with the postoperative follow-up. Those with one of the above (1) to (3), and those with (4) to (7), can be considered for surgical treatment. Laparoscopic gastrointestinal short-circuit surgery: gastrointestinal short-circuit surgery (gastric bypass, GB) was first proposed by Mason et al. in 1967 and used to treat obesity, which is the earliest gastric surgery for the surgical treatment of obesity. In 1977 Alden proposed to replace GB with Roux-en-Y gastric bypass (RYGBP), which is a minimally invasive surgical technique, Due to the application of minimally invasive surgical techniques, laparoscopic RYGBP has now replaced traditional open RYGBP as the mainstream procedure in the United States. The technical points include an isolated gastric storage pouch of 15-30 ml, completely separated from the distal stomach or at least separated by a linear cutting anastomosis with four rows of staples, anastomosis of the gastric bursa with the Roux arm of the jejunum either before or after the colon, anastomosis diameter 0.75-1.25 cm, length of the Roux arm chosen according to the patient’s obesity, generally 75-150 cm. 2001 Rutledge first reported laparoscopic mini-gastric short-circuiting. The length of the proximal jejunal collaterals was selected according to the patient’s obesity, generally 40-200 cm. laparoscopic mini gastric short-circuiting reduced one anastomosis compared with the low colonic anterior gastric bursa and jejunal anastomosis, which made the operation less difficult, shortened the operation time, and reduced the incidence of anastomotic leakage. The mortality rate of RYGBP surgery is 0%-1.5%, and the main complications are anastomotic leak, pulmonary embolism and intestinal obstruction, with an incidence of 0.6%-6%. Rutledge first reported laparoscopic mini-gastric bypass and modified the gastric bypass by performing Biuroyama II-type gastrojejunostomy after tubular resection of the gastric lesser curvature to form a mini-gastric bypass, reducing the number of two anastomoses to one. The principle of surgical weight reduction by laparoscopic mini-gastric bypass is similar to that of laparoscopic Roux-en-Y gastric bypass, which reduces the absorption of food by reducing the volume of the stomach and the anastomosis across the duodenum and part of the jejunum. In terms of surgical operation, laparoscopic Roux-en-Y gastric bypass requires an anterior or postcolonic gastric bursa and jejunum anastomosis at a high level, whereas laparoscopic mini-gastric bypass performs an anterior colonic gastric bursa and jejunum anastomosis at a low level, reducing 1 anastomosis. As a result, the difficulty of the operation is reduced, the operation time is shortened, and the learning curve of the operation is reduced from 75-400 cases for laparoscopic Roux-en-Y gastric bypass to about 30 cases. The length of proximal jejunal collaterals for laparoscopic mini-gastric bypass was selected between 40 and 200 cm according to the patient’s obesity, and the longer the length of proximal jejunal collaterals the better the weight loss effect, but postoperative iron deficiency anemia and malnutrition are likely to occur. Li Weijie et al. suggested that BMI < 40 and the length of proximal jejunal collaterals is around 150 cm, and the length of proximal jejunal collaterals can be adjusted according to BMI. Laparoscopic Roux-en-Y gastric bypass preserves only lO a 30mL of the gastric bursa, whereas laparoscopic mini-gastric bypass removes the gastric bursa tubularly, preserves more volume of the gastric bursa, and has a better blood supply, thus reducing the incidence of anastomotic leak. Laparoscopic adjustable gastric banding (LAGB): LAGB is performed to achieve weight loss by restricting intake. The adjustable gastric banding was designed by Kuzmak in 1983, using an adjustable gastric band made of silicone, which is inserted into the patient through traditional open surgery. In 1993, Belachew et al. in Belgium were the first to laparoscopically insert a modified banding, which was called LAGB. LAGB is currently the most performed bariatric procedure every year, and is most popular in Europe and Australia. The weight loss after LAGB is moderate, with a weekly weight loss of 0.5 to 1.0 kg within 2 years, an EWL of 30% to 40% in the first year after surgery, about 50% of the overweight portion in the second year after surgery, and 50% to 60% in the third year after surgery, and a 25% reduction in preoperative BMI. Complications are rare and there are almost no deaths. Patients can have their gastric banding adjusted in the outpatient clinic one month after surgery, and thereafter the total amount of water injection can be increased or decreased according to the weight loss. There are some specific complications associated with this procedure, including gastric prolapse, outlet obstruction, dilatation of the esophagus and gastric bursa, erosion of the gastric wall by the banding and even necrosis of the gastric wall, and some problems related to the injection pump such as pump failure and implant infection. These complications are becoming less and less frequent as experience with the procedure is gained. LAGB is the simplest and safest bariatric procedure at present because it does not damage the integrity of the gastrointestinal tract and does not change the inherent physiological state of the gastrointestinal tract, and it is completely reversible. Indications and contraindications for GBP treatment of type 2 diabetes Contraindications (1) Contraindications to laparoscopic abdominal surgery: severe intra-abdominal adhesions, severe intra-abdominal infection, severely impaired respiratory and circulatory function, inability to tolerate general anesthesia or pneumoperitoneum, severe impairment of liver and kidney function, severe bleeding tendency, etc.; (2) history of diabetes mellitus for less than 5 years; (3) history of more severe psychiatric or psychological disorders or alcoholism; (4) condition complexity, estimated difficulty in successful surgery, and high surgical risk rate; (5) unwillingness to accept long-term changes in dietary habits. Observation indexes:Preoperative and 1 month postoperative observation of changes in BMI, oral glucose tolerance test, and diabetic complications. Pre-operative testing indexes: three routine, liver and kidney function electrolytes, full set of blood lipids, fasting blood glucose, 2 hours postprandial blood glucose, chest X-ray, ECG, cardiac ultrasound, blood gas analysis, pulmonary function, BMI, waist circumference, barium meal of gastrointestinal tract, consultation of relevant departments (endocrinology, anesthesiology, ICU, cardiology, pulmonary medicine). Postoperative testing indexes: three routine, liver and kidney function electrolytes, blood lipids, fasting blood sugar, 2 hours postprandial blood sugar, BMI, waist circumference.