What is a Gastric Bypass?
Gastric Bypass, also known as Roux-en-Y Gastric Bypass, is primarily a combined restrictive and metabolic weight loss procedure with a mildly malabsorptive component. The surgery involves in creating a small pouch at the top of the stomach and bypassing the flow of food away from the first part of the small intestine and directly into the middle part of the small intestine. The weight loss effect is primarily achieved through limiting the amount of food stored in the small pouch and the hormonal changes that occur through diverting food away from the first part of the small bowel. There is also a small limiting effect on the absorption of food.
Indications for Gastric Bypass
Gastric Bypass surgery is indicated for morbidly obese individuals with the following criteria:
- BMI is ≥ 40
- BMI is 35-39.9 with at least one or more associated co-morbidities such as type 2 diabetes, high blood pressure, high cholesterol level, heartburn, joint problems, breathing problems (obstructive sleep apnoea), etc…
- BMI is 30-34.9 with uncontrolled or poorly controlled type 2 diabetes with multiple anti-diabetic medications (including insulin)
Why choose this procedure?
Roux-en-y Gastric Bypass has been considered by some as the “Gold standard” of bariatric procedure which accounts for its enduring popularity in many parts of the world since it was first performed in 1967. Besides a greater efficacy in weight loss, the metabolic component of the procedure has a better chance of normalising the blood sugar level in type 2 diabetic patients when compared to the other weight loss procedures. It is also the procedure of choice for those with bad concurrent heartburn/reflux disease.
The excess weight loss is expected to be around 60-70%.
Advantages of Gastric Bypass
The advantages of gastric bypass include:
- Better weight loss efficacy than gastric band and sleeve gastrectomy
- Higher rate of resolution/improvement of obesity-related conditions
- It is an anti-reflux operation and is thus most suitable for those with bad reflux/heartburn
- It may be better for uncontrolled or poorly controlled type II diabetes
- No implant device in the body
Disadvantages of Gastric Bypass
- Technically more complex than gastric banding or a sleeve and potentially could result in greater complication rates
- Risk of dumping syndrome, stomal ulcer and internal hernia
- Potential for long-term vitamin/mineral deficiencies (particularly with iron, B12, calcium and folate) which requires regular monitoring
- Requires strict adherence to life-long vitamin/mineral supplementation, dietary recommendations, and follow-up compliance
Gastric Bypass Procedure
Gastric bypass surgery is performed laparoscopically (key-hole surgery) under general anaesthesia. The surgeon makes 5 small incisions in the abdominal wall through which a camera and surgical instruments can be inserted into.
The first stage of the surgery involves in reducing the amount of food that can be stored in the stomach to reduce your calorie intake. This is achieved by creating a small stomach pouch below the oesophagus using a stapler/cutting device.
The second stage involves in construction of a bypass for food to flow from the new created stomach pouch to the lower segments of the small intestine.
After division of the upper segment from the lower segment of the small intestine, the lower segment (which is often referred to as the “Roux limb”) is then attached to the stomach pouch. The upper section of the small intestine which carries bile and digestive juices from the liver, pancreas and the remaining portion of the stomach is then joined to the lower end of the Roux limb. Below this joint is where food can mix with the digestive enzymes and this last segment of bowel is often referred to as the “Common limb”.
Post-operative Care for Gastric Bypass
After the surgery, you will typically be staying in the hospital for about 3-4 days. Your doctor will prescribe pain-killers and anti-nausea medications to keep you comfortable following the procedure. Your nurse will help you to move at the earliest after the surgery to prevent blood clots, respiratory problems and bedsores. The swelling in your stomach after the operation can sometimes make it difficult to drink which is a normal process. However, it is important to remember to sip water throughout the day to avoid dehydration (especially in the first 1-2 weeks).
You will be kept on a liquid diet for the first 1-2 weeks post-op and then, depending on your progress of recovery, transition to puree diet and then soft diet at every 1-2 weeks afterwards. Your surgeon or dietician will give you a specific diet plan and instructions to follow after the surgery. You will be advised to take medication to reduce the amount of acid produced by your stomach for the first 3 months. You will also need to start taking multi-vitamins which will continue for life.