2 The condition, current treatments and procedure

2 The condition, current treatments and procedure

The condition

2.1

Obesity is defined as a body mass index (BMI) of 30 kg/mor over. The degree of obesity is classified as:

  • obesity class 1 (BMI 30 kg/m2 to 34.9 kg/m2)

  • obesity class 2 (BMI 35 kg/m2 to 39.9 kg/m2) and

  • obesity class 3 (BMI 40 kg/m2 or more).

    The NICE guideline on obesity recognises that people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean ethnicity are prone to central adiposity and their cardiometabolic risk occurs at a lower BMI. So, a lower BMI of 27.5 kg/m2 or above is recommended as the threshold for obesity in these groups.

2.2

Obesity is directly linked to a number of other illnesses including type 2 diabetes, hypertension, gallstones and gastro-oesophageal reflux disease, as well as psychological and psychiatric morbidities. Weight loss reduces the risk of comorbidities and improves long-term survival.

Current treatments

2.3

The NICE guideline on obesity recommends a multicomponent approach involving dietary advice, exercise, lifestyle changes and medication. Bariatric surgery is recommended as an option in some people who have class 3 obesity, or class 2 obesity and other significant disease (such as type 2 diabetes) and have not lost enough weight using other methods. It is also considered at a lower BMI threshold than in other populations in people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean ethnicity. This is because these groups are prone to central adiposity and cardiometabolic risk occurs at a lower BMI.

2.4

Surgical procedures for obesity aim to help people to lose weight and to maintain weight loss by restricting the size of the stomach, decreasing the capacity to absorb food, or both. Procedures that reduce the size of the stomach (gastric volume) limit the capacity for food intake by producing a feeling of satiety with a smaller ingested volume of food. They include laparoscopic gastric banding and sleeve gastrectomy. Procedures that aim to decrease the capacity to absorb food include biliopancreatic diversion and duodenal switch. People are also advised to modify their eating behaviour by adhering to an explicit postoperative diet advised by specialist dieticians.

The procedure

2.5

Endoscopic sleeve gastroplasty is a minimally invasive transoral endoscopic procedure that reduces the volume of the stomach and may delay gastric emptying. It creates a sensation of fullness and reduces the amount of food that can be eaten at one time.

2.6

The procedure is done under general anaesthesia. It may be done as a day case, but most people are kept under observation overnight and discharged the next day. A single or a double channel scope with a procedure-specific endoscopic device attached is passed through the mouth (transorally). A series of endoluminal full-thickness suture plications (in a U, Z, square, triangle or rectangle pattern) are done along the greater curvature of the stomach (through the gastric wall, extending from the pre-pyloric antrum to the fundus). This involves folding the stomach in on itself and stitching it together, creating a restrictive endoscopic sleeve to reduce the stomach volume by about 70% to 80%. There is no resection of the stomach and the procedure may be reversible in the early stages.