Preoperative workup

  • Preoperative patient evaluation should include an assessment of endocrine, metabolic, physical, nutritional, and psychologic health.
  • Preoperative patient evaluation should include routine clinical tests and diabetes-specific metrics. The DSS-II group recommends the following:
    • Standard preoperative tests used for GI surgery at that particular institution
    • Recent tests of the patient’s diabetes status, including HbA1c, fasting glucose, lipid profile, retinopathy, nephropathy, and neuropathy
    • Tests to distinguish type 1 diabetes from type 2 diabetes
  • An attempt to improve glycemic control should be made before surgery to reduce the risk for postoperative infection due to hyperglycemia.

Choice of procedure

  • Of the 4 accepted operations for metabolic surgery, RYGB appears to have the most favorable risk-benefit profile for most patients with type 2 diabetes.
  • Longer-term studies are needed for VSG, though current evidence suggests it results in significant weight loss and major improvement of type 2 diabetes.
  • LAGB is effective for improving glycemic control in patients with obesity and type 2 diabetes, but it has a greater risk for reoperation/revision compared with RYGB due to failure or band-related complications.
  • Evidence suggests that BPD/BPD-DS may be the most effective procedure for improving glycemic control and weight loss. However, the procedure has a significant risk of nutritional deficiencies that makes its risk-benefit profile less favorable than the other 3 procedures for most patients. BPD/BPD-DS should be considered only for patients with extreme levels of obesity.

Postoperative follow-up

  • After surgery, the patient should continue to be managed by a multidisciplinary team that includes endocrinologists, surgeons, nutritionists, and nurses with diabetes expertise.
  • Follow-up should include surgical and nutritional evaluations at least every 6 months for the first 2 years post-surgery. Follow-ups should occur at least annually thereafter.
  • Glycemic control should be monitored according to standard diabetes care, unless the patient has a documented, stable condition of nondiabetic glycemia.
  • Patients who have reached stable normalization of hyperglycemia for at least 6 months should have their glycemic control monitored with the frequency recommended for patients with prediabetes.
  • Patients with stable nondiabetic glycemia for less than 5 years should be monitored for diabetes-related complications at the same frequency as before remission. When a patient has been in remission for 5 years, monitoring can be performed less frequently.
  • During the first 6 months after surgery, patients should be evaluated for glycemic control, and antidiabetes medication(s) should be tapered according to clinician opinion. Medication should not be discontinued until laboratory proof of stable glycemic normalization for at least 2 3-month HbA1c cycles is obtained.
  • If plasma glucose levels rapidly approach the normal range in the early postoperative stage, adjustments to medications should be made to prevent hypoglycemia. Metformin, thiazolidinediones, GLP-1 analogs, DPP-4 inhibitors, α-glucosidase inhibitors, and SGLT2 inhibitors all have low risks of inducing hypoglycemia.
  • Patients must be provided with ongoing and long-term monitoring of micronutrient status, nutritional supplementation, and support that adheres to guidelines for postoperative management of metabolic/bariatric surgery by national and international societies.

“The new guidelines provide much needed guidance for general practitioners, endocrinologists, and diabetes specialists about the use of metabolic surgery in the treatment of obese patients with [type 2 diabetes],” said William T. Cefalu, MD, executive director of the Pennington Biomedical Research Center at Louisiana State University, in a related commentary. “Compared with previous guidelines for bariatric surgery, which used only BMI thresholds to select surgical candidates, the DSS-II recommendations introduce the use of diabetes-related parameters to help identify clinical scenarios where surgical treatment of [type 2 diabetes] should be prioritized.”

References

  1. Rubino F, Nathan DM, Eckel RH, et al. Metabolic surgery in the treatment algorithm for type 2 diabetes: a joint statement by international diabetes organizations. Diabetes Care. 2016; 39(6):861-877.
  2. Cefalu WT, Rubino F, Cummings DE. Metabolic surgery for type 2 diabetes: changing the landscape of diabetes care. Diabetes Care. 2016; 39(6):857-860.