1.Background
Diabetes mellitus has become one of the chronic diseases that seriously threaten human health. Coronary heart disease, nephropathy, retinopathy and neuropathy caused by diabetes mellitus are the main causes of death and disability of patients. According to the latest diagnostic criteria of the American Diabetes Association (ADA) in 2010, diabetes is diagnosed with one of the following four conditions: (1) glycated hemoglobin (A1C) ≥ 6.5%; (2) fasting blood glucose (FPG) ≥ 7.0 mmol/L; (3) 2-hour blood glucose ≥ 11.1 mmol/L in oral glucose tolerance test (OGTT); (4) having symptoms of hyperglycemia or hyperglycemic crisis with random blood glucose ≥ 11.1 mmol/L.
According to WHO, the prevalence of diabetes in the world is increasing substantially year by year. The current prevalence of diabetes in adults in China is about 9.7%, with a total of about 90 million, of which type 2 diabetes mellitus (T2DM) accounts for 90%. Diabetes mellitus is an ancient medical disease. Traditional treatment methods include diet control, exercise, oral hypoglycemic drugs and insulin injection therapy, etc. However, these treatment methods can hardly cure diabetes mellitus fundamentally, keep patients’ blood glucose stable for a long time, nor can they prevent the occurrence and development of various complications of diabetes mellitus fundamentally. Strict dietary control and repeated fluctuations in blood glucose levels cause continuous mental stress to patients and affect the quality of life. Patients urgently need a treatment that provides good control of diabetes and its complications.
Diabetes usually coexists with obesity, and about 90% of patients with T2DM are obese or overweight. With the recent boom of bariatric surgery in China and abroad, more and more obese patients are undergoing bariatric surgery with good weight loss results. However, it is surprising that these bariatric surgeries are effective in reducing the patient’s weight while also improving the co-existing disorders of glucose metabolism in most patients. Some obese patients with preoperative coexisting diabetes are in clinical remission or even complete clinical remission after undergoing surgery. There is even a growing body of research and evidence that these gastrointestinal surgical procedures are more effective in treating even normal weight diabetic patients.
The main mechanisms of gastrointestinal surgery for the treatment of diabetes may be: (1) reduced food intake and absorption, thus reducing energy intake and glucose metabolic load; (2) lowering the patient’s body weight and reducing insulin resistance due to the fat accumulation of simple obesity; (3) altering the secretion of hormones in the intestine-insulin axis after gastrointestinal tract reconstruction, thus improving glucose metabolism. Currently, there are five clinically proven surgical methods for the treatment of type 2 diabetes, namely “Y” gastrointestinal short-circuiting, modified simple gastrointestinal short-circuiting, biliopancreatic open-ended or duodenal transposition, tubular gastrectomy and adjustable gastric banding. The surgical treatment of type 2 diabetes may involve several different clinical disciplines, so it is recommended that the surgery should be performed in a comprehensive medical unit of secondary and higher level. The surgeon should be a gastrointestinal surgeon with an intermediate or higher title, who has been practicing in general surgery for a long time, and should only perform the surgery after understanding the treatment principles and operational guidelines of the various procedures, and after systematic instruction and training. Different surgeons may prefer different surgical approaches, and we are currently trying to determine the best surgical treatment plan for a particular patient, but so far we can only recommend a few methods that are commonly used in clinical practice and have been shown to be relatively safe and effective. Experience has shown that for patients with significant type 2 diabetes, we can choose a “Y” gastrointestinal short-circuit or a modified simple gastrointestinal short-circuit, and adjust the length of the bypass according to the patient’s weight; for patients with predominantly obesity and mild glucose disorders or hypoglycemia, especially in younger patients, we suggest the option of adjustable gastric banding. For very high-risk diabetic patients with severe obesity or other serious complications, we can first perform a tubular gastrostomy and then decide whether a second stage of surgery is needed depending on the patient’s postoperative condition. These procedures can be done either by conventional open approach or by laparoscopic surgery. Compared with conventional open surgery, the effectiveness of laparoscopic surgery is the same as that of cesarean surgery, but the advantages of less trauma, less bleeding, faster recovery and relatively fewer complications are more obvious.
2.Patient selection
All patients with type 2 diabetes mellitus who experience poor results or cannot tolerate after long-term non-surgical treatment can be considered for gastrointestinal surgery as long as there are no obvious contraindications to surgery.
Since the effect of surgical treatment for type 2 diabetes is related to various factors such as the duration of their diabetes, islet cell function, and the patient’s age, we believe that a better outcome can be expected when the patient meets the following conditions: (1) the patient is ≤65 years old; (2) the patient has had T2DM for ≤15 years; (3) the patient’s islet reserve function is above 1/2 of the lower limit of normal and C-peptide ≥2. At the same time The patient has no serious mental disorder or intellectual disability; the patient fully understands the surgical modality for the treatment of diabetes, understands and is willing to bear the risk of potential complications of the surgery, understands the importance of postoperative diet and lifestyle changes and is willing to bear them; the patient can actively cooperate with the postoperative follow-up and other aspects are also considered in the selection of surgery.
It should be pointed out that: since obesity in China is mostly abdominal obesity, which has a higher risk of cardiovascular accidents and other complications, surgery should be considered more actively when the waist circumference is ≥90 cm in men and ≥80 cm in women. Meanwhile, for patients with normal or overweight and combined with type 2 diabetes (BMI<28kg/m2), although the current preliminary data show that surgical treatment also has better effect in this part of the population, further clinical randomized controlled studies and demonstration are still needed on the basis of fully informed consent, and it is not suitable for large-scale promotion for the time being.
3. Pre-operative consultation
The surgical treatment of diabetes is also a team effort. In addition to general surgery, these hospitals must be equipped with sound consultation departments, such as anesthesiology, endocrinology, nutrition, cardiology, respiratory medicine, psychiatry, ophthalmology, neurology, and vascular surgery. It is necessary to conduct relevant consultation for different patients.
4.File information
Detailed files of type 2 diabetic patients should be established. Not only the files of surgically treated patients should be kept, but also the files of those who come for consultation; that is, not only the patients after surgery should be followed up during the follow-up prevention, but also the patients who are not operated can be followed up frequently. Essential information includes the patient’s gender, age, contact information, height, weight, abdominal circumference, BMI, duration of diabetes, the treatment plan being taken, the effect of treatment, and whether other complications are present.
All preoperative and postoperative follow-up data should be filed in a timely manner.
5.Anesthesia and recovery
Preoperative assessment and medication: (1) Respiratory function: pulmonary function, arterial blood gas and tolerance assessment of supine position should be included as routine. Those with combined hypoxia and/or hypercapnia in the supine position have poor perioperative tolerance and every effort should be made to correct them. (2) Circulatory function: To understand the history and symptoms of hypertension, pulmonary hypertension, myocardial ischemia, etc. Echocardiography is a valuable index to determine cardiac function and pulmonary hypertension. 60% of ECG misses are diagnosed. (3) Difficult airway assessment: A clear diagnosis of preoperative OSAS (obstructive sleep apnea syndrome) is an important measure to ensure perioperative safety. For those with combined anatomical and pathological anatomical abnormalities of the upper airway, consultation with relevant departments should be requested in a timely manner. (4) Preoperative medication: avoid the application of opioids as much as possible, and the use of sedative drugs should be performed under close supervision. (5) Maintenance of preoperative blood glucose: maintain the patient’s random blood glucose ≤ 12 mmol/L within three days before surgery.
Key points of intraoperative anesthetic management: (1) Since most type 2 diabetic patients are combined with obesity, adequate preparation for difficult airway should be made. (2) The use of awake induction or express induction intubation depends on the results of airway assessment, the experience of the anesthesiologist and the conditions available in the department. (3) Intraoperative respiratory circulation monitoring should be exact, and invasive monitoring can be used if necessary. (4) The effect of weight gain on pharmacokinetics is difficult to predict accurately, and inhalation anesthesia or static inhalation complex anesthesia is recommended. (5) Perioperative pulmonary atelectasis and decreased pulmonary compliance are the focus of intraoperative respiratory management.
Postoperative extubation and analgesia: (1) ICU or PACU supervised extubation should be listed as routine, and adequate preparation for ventilation assistance and support should be made. (2) Postoperative analgesia should avoid the use of opioids as much as possible and be performed under close supervision. (3) Postoperative blood glucose monitoring should also be a priority.
6. Equipment and instruments
A complete set of conventional gastrointestinal surgical instruments is required for caesarean section. Patients with diabetes combined with extreme obesity should be prepared with extended open surgical instruments. Some procedures require different types of anastomoses and/or linear cutting closures. Laparoscopic surgery requires, in addition to a laparoscopic main unit, a 30-degree laparoscope, different types of puncture trocars and extension trocars, non-invasive gastric and intestinal grasping forceps, liver retractors, and pneumoperitoneum needles; depending on the proposed surgical approach, adjustable gastric straps, Gold finger, which is used to create the “posterior gastric tunnel” and introduce the adjustable gastric banding, needle holders, lumpectomy anastomoses and linear cutting closures, ultrasonic knife, etc. For patients with diabetes combined with extreme obesity, the size of the operating table, the weight-bearing capacity, the movement of the body position after the weight-bearing capacity and the floor fixation of the operating table should meet the requirements in order to ensure the successful completion of the operation.
7.Surgical methods and effect evaluation
(1) “Y” type gastrointestinal short-circuit surgery
Surgical technique: The volume of the gastric bursa should be as small as possible, and according to the literature, it is best to limit it to about 12ml~25ml. The gastric bursa should be completely separated from the distal side of the stomach or at least separated by a direct cutting anastomosis with four rows of staples. The entire duodenum is left open as well as at least 40 cm above the proximal jejunum. The anastomosis of the gastric bursa to the Roux arm of the jejunum can be either anterior or posterior to the colon. The diameter of the anastomosis is between 0.75 cm and 1.25 cm. The length of the Roux arm is generally limited to between 75 cm and 150 cm, which can be adjusted according to the patient’s weight.
Diabetes treatment effect: The efficiency of treating type 2 diabetes can reach 80% to 85%, and the treatment effect can be expected to be maintained for a long time.
Surgical complications: The perioperative mortality rate is about 0.5%, and the incidence of surgical complications such as anastomotic leak, bleeding, incisional infection, and pulmonary embolism is about 5%. Long-term complications may include tipping syndrome, anastomotic stenosis, marginal ulceration, closure line dehiscence, and internal hernia. Lifelong Vit B12 supplementation is required, as well as iron, Vit B complex, folic acid, and calcium as needed.
The “Y” gastrointestinal shortcut is the procedure of choice for the surgical treatment of diabetes mellitus. However, the operation is relatively complicated, the postoperative complication rate is relatively high, and the postoperative monitoring and supplementation of relevant nutrients are required, so when the corresponding conditions are not available, the modified simple gastrointestinal short-circuit can usually be chosen with comparable results but less risk.
(2) Modified simple gastrointestinal short-circuiting
Surgical technique: The gastric wall is cut into a long tubular stomach along the lesser curvature of the stomach near the gastric angle with an automatic cutter closure and separated to the left of the esophagogastric junction. The width of the tubular stomach is approximately equal to the width of the esophagus and can be assisted by intraoperative gastroscopy. The small intestine is selected at least 100 cm below the Treitz ligament, and a lateral gastrointestinal anastomosis is made with the remnant stomach using a linear cutting closure, which is finally closed at the anastomotic operation hole.
Selection of the length of the short circuit: The bypass of the modified simple gastrointestinal short-circuit needs to be of sufficient length, generally requiring a short circuit of 100 cm to 200 cm of small intestine, which can be adjusted according to the weight of the patient. However, care should be taken that it should not be too close to the end of the ileum, otherwise it will easily lead to long-term persistent diarrhea and malnutrition after surgery.
Effectiveness of diabetes treatment: The treatment efficiency of type 2 diabetes can reach 75% to 85% on average. Sometimes the therapeutic effect can appear immediately after surgery.
Complications: The perioperative mortality rate is <0.5%. The most common postoperative complication is anastomotic leak, with an incidence of about 1% to 2%, followed by postoperative bleeding. The most common long-term complications are marginal ulcers and reflux esophagitis, with an incidence of approximately 5% to 7%, and the application of proton pump inhibitors is more effective. Dumping syndrome can occasionally be encountered in patients.
Modified simple gastrointestinal short-circuiting is a newer short-circuiting procedure that is simpler than the “Y” gastrointestinal short-circuiting procedure, with a further reduction in operative time and postoperative complication rates, but is nearly as effective in the treatment of type 2 diabetes. In clinical surgical treatment, if the conditions for “Y” type gastrointestinal short-circuiting are not available, this procedure should be considered as much as possible. It should be noted that patients after modified simple gastrointestinal short-circuiting are prone to more obvious reflux symptoms, which seriously affects the quality of life of patients, and if necessary, the addition of small bowel lateral anastomosis (Brown anastomosis) can be considered.
(3) Biliopancreatic open surgery and duodenal transposition
Surgical technique: Both procedures require preservation of approximately 100 ml to 150 ml of gastric sac; the common channel formed by the confluence of intestinal and biliopancreatic collaterals is 50 cm to 150 cm proximal to the ileocecal valve. The proximal end is then anastomosed with the low ileum 50 cm above the ileocecal valve. For duodenal diversion, a tubular gastric gastrectomy is performed, the pylorus is preserved and transected at the duodenum, the proximal duodenum is anastomosed with the distal small intestine cut 250 cm above the ileocecal valve, the distal duodenum is closed with an anastomosis, and the proximal small intestine cut 250 cm above the ileocecal valve is anastomosed with the ileum 100 cm above the ileocecal valve.
Diabetes treatment effect: The treatment effect of type 2 diabetes is the best, and the efficiency can be as high as 95% to 100%.
Complications: The perioperative mortality rate is about 1%, and the complication rate is about 5%. Long-term complications may include diarrhea, vitamin, mineral and nutrient deficiencies, especially protein deficiency. Daily protein supplementation of 75g to 80g is required, as well as Vit B, calcium and iron. Patients undergoing biliopancreatic obliteration may also develop dumping syndrome.
Although the results of these two procedures are excellent, the surgical operation is extremely complicated, and the complications and mortality rates are higher than other procedures, plus the nutritional metabolism disorders should be strictly monitored regularly and supplemented in a timely and correct way, so it is not recommended to promote them for the time being in China.
(4) Tubular gastric gastrectomy
Surgical technique: The large part of the stomach is removed in the direction of the large curvature of the stomach to preserve 4cm-8cm of the gastric sinus above the pylorus, so that the residual stomach is “banana-shaped” about the diameter of the gastroscope channel, and the volume is about 100ml.
Diabetes treatment effect: tubular gastric gastrectomy has good treatment effect on type 2 diabetes, the cure rate can reach about 65%.
Complications: Rare cases of death in the perioperative period. This procedure does not alter the physiology of the gastrointestinal tract and does not produce a lack of nutrients. Gastric resection is accomplished using a cutting anastomosis, and complications to be prevented are bleeding, leakage, and stricture of the incision margin.
In patients with type 2 diabetes mellitus who are extremely obese and at high risk for other serious complications, this procedure can be performed first to eliminate the associated risk factors earlier using relatively safe means. Thereafter, the need for second-stage surgery is determined by the patient’s postoperative condition and the actual outcome of treatment. The second-stage surgery is usually performed 6 to 18 months after the first-stage surgery.
(5) Adjustable gastric banding
Surgical technique: The gastric bursa should be as small as possible, limited to approximately 15 ml, and located mainly in the anterior wall of the stomach. The anterior gastric wall suture should be firmly and precisely fixed with the anterolateral segment of the band completely buried and not too tightly buried. The injection pump should be firmly fixed to the anterior rectus abdominis sheath after attachment. Adjustment by the injection pump is an important part of this surgical treatment and affects the outcome of the treatment.
Effectiveness of diabetes treatment: The remission rate of type 2 diabetes can reach 60% to 65%. The effect is slow and generally requires a significant weight loss in the patient before the treatment effect begins to appear.
Complications: The complication rate of this procedure is about 5%, and the perioperative mortality rate is about 0.1%. There are some specific complications of 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, as well as some problems related to the injection pump such as pump failure and implant infection.
Adjustable gastric banding is the least invasive of all procedures. This procedure does not damage the integrity of the gastrointestinal tract and does not alter the inherent physiology of the gastrointestinal tract. It is completely reversible. In cases of poor post-operative results, the procedure can be adapted to any other form of surgery.
Because of the relative ease of operation, the low number of complications, and its reversibility, this procedure is recommended for patients with mild diabetes mellitus in combination with obesity or with reduced glucose tolerance, and is particularly suitable for younger patients, allowing for safe and effective modulation during their growth and development and specific physiological changes (e.g., pregnancy). It is important to note that the glycemic control of this procedure is directly related to the patient’s excess weight loss, and in cases where weight loss is poor, diabetes treatment is also poor.
(6) Others
As the research on surgical treatment of diabetes progresses, more and more new procedures are emerging. Among them, Duodenum-Jejunal Bypass (DJB) and Ileal Transposition (IT) have shown good results in the treatment of type 2 diabetes. However, the effectiveness, safety and cost-effectiveness of these procedures still need further observation, research and demonstration, so they are not recommended for the time being.
8. Post-operative guidance
Patients need to be made aware of the need for lifelong follow-up after surgical treatment.
At least three outpatient follow-up visits, as well as more telephone or other follow-up visits, should be conducted during the first year after surgery. The main contents of the follow-up visits include the patient’s blood glucose, glycosylated hemoglobin, insulin, and C-peptide, as well as the patient’s weight, nutritional status, and mental status. The purpose of the follow-up visit is to grasp the control of the patient’s type 2 diabetes, whether the patient still needs adjuvant treatment with diet or medication, and to monitor whether the patient has any complications related to diabetes and whether there is any improvement after surgery. Also, to monitor for the occurrence of surgical complications and for any nutrient, vitamin or mineral deficiencies so that timely therapeutic adjustments can be made. For some discomfort of patients, necessary medication and psychological counseling are also required. For example, patients with chronic heartburn and acid reflux may be given appropriate medication to inhibit gastric acid and protect gastric mucosa, etc. All the follow-up contents should be detailed and exact, and filed in time.
For patients who underwent adjustable gastric banding, the number of outpatient follow-up visits should be increased so that the banding can be adjusted appropriately. The first adjustment is performed one month after the operation. The first water injection should be <4 ml and thereafter adjusted periodically according to the patient's condition, taking care not to exceed the maximum limit.
Dietary guidance is a crucial part of ensuring the effectiveness of surgical treatment, avoiding long-term postoperative complications, and improving various postoperative discomforts of patients. The aim is to form a new diet to promote and maintain the improvement of glucose metabolism while supplementing essential nutrients and avoiding patient discomfort. The measures are to drink adequate amount of fluids, eat sufficient protein, and supplement essential vitamins and minerals. The methods are as follows: (1) low sugar and low fat diet; (2) avoid over-eating; (3) eat slowly, about 20-30 minutes per meal; (4) chew and swallow slowly, avoiding foods that are too hard or large; (5) eat protein-rich foods first and avoid high-calorie foods; (6) depending on the surgical modality, some require daily essential vitamin supplementation and mineral supplementation according to instructions; (7) (7) Ensure adequate daily fluid intake and avoid carbonated beverages.
9. Judgment of efficacy
According to the guidelines of the American Diabetes Association and the related literature, the following signs of cure or remission of type 2 diabetes after surgery can be judged as effective treatment: (1) Patients who are treated with diet, oral medication or insulin before surgery no longer need any of the above interventions after surgery, and can maintain random blood glucose <11.1mmol/L, fasting blood glucose <7.0mmol/L, and fasting blood glucose <7.0mmol/L for a long time. (2) Patients who require preoperative glucose therapy, oral medication or insulin therapy can be considered to be in complete clinical remission. (2) Those who need to use insulin to control blood glucose before surgery, but only need oral medication or diet adjustment to control blood glucose to normal after surgery, can be judged as clinical partial remission. (3) Those who need oral hypoglycemic drugs to control blood glucose before surgery, but only need dietary adjustment to control blood glucose to normal after surgery, can be judged as clinical partial remission. (4) There are obvious complications of type 2 diabetes mellitus before surgery, such as diabetic nephropathy and diabetic retinopathy. If these diabetic complications disappeared or remitted after surgery, the treatment was judged to be effective. (5) If there are other manifestations of metabolic disorder syndrome, such as obesity, hyperlipidemia, hypertension, respiratory sleep apnea syndrome, etc., before surgery, and these metabolic disorder syndrome disappears or remits after surgery, the treatment is also considered effective.