There are different types of weight loss or bariatric surgery available today. What will happen during and after this weight loss surgery depends on the type of procedure you undergo.
Bariatric surgery involves procedures that are used to help people with morbid obesity and related disorders to lose extra weight. These procedures basically work in any of the following three ways:
- Restriction: This involves physically limiting the amount of food your stomach can hold at a time. This limits the calories and such procedures are known as restrictive weight-loss surgeries.
- Malabsorption: In this, the digestive system is prevented from absorbing all the nutrition and calories in the food. These are called malabsorption surgeries. It may be done by shortening or bypassing part of the small intestine.
- A combination of these two methods
Based on these underlying methods, there are four main types of weight loss surgeries that are commonly performed:
- Roux-en-Y gastric bypass:
In gastric bypass surgery, the surgeon creates a small pouch by dividing the top part of the stomach from the remaining part. The pouch can hold only a small volume of food. As it is the only part of the stomach that receives food, thus limiting the amount of food you can comfortably eat and drink at a time.
In the next step, the surgeon divides the intestine into portions and the bottom end of the portion is brought up to connect with the small pouch of the stomach. Food that you eat will directly flow from the pouch into this part of the intestine. The main part of the stomach continues to produce digestive juices. The part of the intestine that is still attached to the main stomach is then reattached lower down. This allows the digestive juices to flow and mix with the food in the small intestine. As the food will now bypass a large portion of the small intestine, only fewer nutrients and calories can be absorbed.
- Laparoscopic adjustable gastric banding:
This involves the placement of a medical device called an adjustable gastric band into the stomach. The device contains an inflatable balloon which is placed around the top part of the stomach. This works by creating a smaller stomach pouch of the stomach with a very narrow opening for food to pass through to the rest of the stomach. It restricts the amount of food the stomach can hold. Therefore, eating only a small amount of food will satisfy hunger quickly and promote the feeling of fullness. However, this feeling of fullness will depend upon the size of the opening between the pouch and the rest of the stomach. The size of the opening can be adjusted by inflating the band with sterile saline, injected through a port placed under the skin.
This process does not involve malabsorption of nutrients and the food is digested and absorbed in the body as it would be normally.
The band seems to help in reducing hunger, which enables the patients to limit the number of calories they consume.
Gastric band surgery in India is a popular procedure and offered by various hospitals at a comparatively lower cost than in other countries.
- Sleeve gastrectomy:
The laparoscopic sleeve gastrectomy procedure is performed by removing 75-80% of the stomach. The remaining stomach (sleeve) resembles the tubelike shape of a banana.
The new stomach is small and can hold only a small volume of food than the normal stomach. This helps in significantly reducing the amount of food as well as calories that can be consumed at a time. Also, another major effect of the surgery is on the gut hormones which further impacts a number of factors such as hunger, satiety, and blood sugar levels.
However, it is a non-reversible procedure that can potentially lead to long-term vitamin deficiencies in a person.
- Duodenal switch with biliopancreatic diversion:
The procedure involves two steps: creating a small tubular pouch of the stomach by removing a portion of the stomach and bypassing a large portion of the small intestine.
The first step is similar to sleeve gastrectomy, the surgeon removes a large part of the stomach and leaves a smaller tube-like stomach portion. The valve that is responsible for releasing the food into the small intestine is left intact, along with duodenum, the first part of the small intestine.
Then, the surgeon closes off the middle part of the intestine and connects the last part directly to the duodenum. This is known as the duodenal switch.
The separated part of the intestine remains within the body only. It’s further reattached to the end of the intestine, to allow digestive juices, such as bile and pancreatic digestive juices to flow into this part of the intestine and mix with food. This is known as biliopancreatic diversion.
The food bypasses most of the small intestine, thus limiting the absorption of nutrients and calories.