bariatric surgery for obesity

Last edited 01/2019 and last reviewed 06/2022

The National Institute for Clinical Excellence has issued recommendations to the NHS on the use of gastric surgery for the treatment of morbid obesity

• for the purposes of the NICE guidance, people are considered to have morbid obesity if they have a body mass index (BMI) of 40 kg/m2 or more or they have a BMI of between 35 kg/m2 and 40 kg/m2 and other significant disease (for example, diabetes, high blood pressure) that may be improved if they lose weight
• NICE has recommended that surgery to aid weight loss should be available as a treatment option for people with morbid obesity provided that they meet all of the following criteria (1):
  
  
  • bariatric surgery is a treatment option for people with obesity if all of the following criteria are fulfilled:
    • they have a BMI of 40 kg/m2 or more, or between 35 kg/m2 and 40 kg/m2 and other significant disease (for example, type 2 diabetes or high blood pressure) that could be improved if they lost weight
      • all appropriate non-surgical measures have been tried but the person has not achieved or maintained adequate, clinically beneficial weight loss
      • the person has been receiving or will receive intensive management in a tier 3 service
      • the person is generally fit for anaesthesia and surgery
      • the person commits to the need for long-term follow-up
        
        
  • bariatric surgery is the option of choice (instead of lifestyle interventions or drug treatment) for adults with a BMI of more than 50 kg/m2 when other interventions have not been effective
    
    
  • bariatric surgery for patients with type 2 diabetes
    • an expedited assessment for bariatric surgery should be offered to people with a BMI of 35 or over who have recent-onset type 2 diabetes as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent
      
      
    • consider an assessment for bariatric surgery for people with a BMI of 30-34.9 who have recent-onset type 2 diabetes as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent)
      
      
    • consider an assessment for bariatric surgery for people of Asian family origin who have recent-onset type 2 diabetes at a lower BMI than other populations as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent)

Types of bariatric surgery:

• bariatric surgery denotes any surgical procedure that is aimed at the reduction of excess weight
  • the conventional bariatric operations are divided as follows:
    
    
    • restrictive type [laparoscopic adjustable gastric banding (LAGB) or laparoscopic sleeve gastrectomy (LSG)]
      • LAGB - adjustable gastric band is a silicone belt with an inflatable balloon in the lining that is buckled into a closed ring around the upper stomach. A reservoir port is placed under the skin for adjustments to the stoma size
      • LSG consists of a 70% vertical gastric resection, which creates a long and narrow tubular gastric reservoir with no intestinal bypass component
        
        
    • malabsorptive type [bilio-pancreatic division with duodenal switch (BPD/DS)]
      • more extreme intestinal bypass along with some modest gastric reduction are the biliopancreatic diversion and the biliopancreatic diversion with duodenal switch operations, which are most often used for 'super' obese patients
      • biliopancreatic diversion combines a subtotal (2/3rds) distal gastrectomy and a very long Roux-en-Y anastomosis with a short common intestinal channel for nutrient absorption
      • biliopancreatic diversion with duodenal switch combines a 70% greater curve gastrectomy with a long intestinal bypass, where the duodenal stump is defunctionalized or 'switched' to a gastroileal anastomosis
        
        
    • combination type [roux-en-Y gastric bypass (RYGB) or mini gastric bypass

Notes:

• there is evidence (mainly from observational studies) that surgical treatment of obesity is more effective than non-surgical treatment for weight loss and control of comorbid conditions in patients with a BMI >= 40 kg/m^2 (3)
• a systematic review concluded that surgery is more effective than conventional management. Certain procedures produce greater weight loss, but data are limited (4)
• with respect to bariatric surgery in obese diabetic patients:
  • a study from Australia revealed that bariatric surgery was dominant over conventional therapy for lifetime management of type 2 diabetes in obese patients (5)

Reference:

• 1. NICE (November 2014). Obesity guidance.
• 2. British Heart Foundation (February 2005). Obesity (4 of 4): Medical and Surgical Interventions.
• 3 Maggard MA et al. Meta-analysis: surgical treatment of obesity. Ann ntern Med 2005;142:547-59.
• 4. Colquitt JL, Picot J, Loveman E, Clegg AJ. Surgery for obesity. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD003641.
• 5. Keating CL et al. Cost-effectiveness of surgically induced weight loss for the management of type 2 diabetes: modeled lifetime analysis.Diabetes Care. 2009 Apr;32(4):567-74