Bariatric Surgery

Weight loss surgery 

Bariatric surgery (BS) consists of a series of surgical procedures that help extremely obese people to lose weight. The surgical intervention is recommended only to patients that cannot achieve weight loss by other means, and/or suffer from severe health conditions related to obesity (such as type 2 diabetes, heart disease, or severe sleep apnea). The procedures of BS include reducing the size of the stomach, resecting, and re-routing parts of the small intestine to the stomach which lead to reduced amounts of ingested food and absorption of calories and nutrients.

Currently, the U.S. National Institutes of Health recommends BS for extremely obese patients with a body mass index (BMI) of at least 40 or for people with a BMI of 35 with severe health problems linked to obesity.

BMI =mass (kg) height ² (m) ;
BMI ranges:
Underweight: <18.5;
Normal weight: 18.5 - 25;
Overweight: 25 - 30;
Obese: >30.

The most common BS procedures are:

• Roux-en-Y Gastric Bypass (Gastric Bypass - GB);
• Sleeve Gastrectomy (the sleeve);
• Adjustable Gastric Band (AGB);
• Biliopancreatic Diversion with Duodenal Switch (BPD/DS) 

Gastric bypass

It’s a 2-part procedure that:

• Creates a small stomach pouch (15-30 mL) by surgically dividing the top (thumb-like in size) stomach from the remaining lower part of the stomach. The division can either be complete or a “wall” between the 2 parts of the stomach could be created.
• Next, the small intestine is divided (approximately at 45 cm below the stomach) and re-arranged into a “Y” configuration. The bottom end of the divided small intestine is brought up and connected to the small stomach pouch, while the top portion - is connected to the small intestine further down. This way, most of the ingested food is not digested by bile and pancreatic juice, which normally is secreted into the duodenum (the top part of the small intestine), but the digestive enzymes will eventually mix with the food in the lower part of the small intestine.

Losing weight is achieved by ingesting smaller amounts of food (due to the smaller size of the stomach). Most of the calories and nutrients are not absorbed (due to re-arranging of the small intestine) and changes in the production of gut hormones result in satiety sensations that lead to fewer meals consumed. 

Sleeve Gastrectomy

Sleeve gastrectomy often called the sleeve, is a laparoscopic procedure that removes approximately 80 % of the stomach, following the major curve of the stomach. The remaining part of the stomach is a tubular sleeve that looks like a banana.
The effect of losing weight is produced by ingesting smaller amounts of food, thus keeping all the digestive functions of the gastrointestinal tract (GIT).
The procedure permanently reduces the stomach size and is irreversible.
In some severe obesity cases, the sleeve is used as the first stage of bariatric surgery, followed by BPD/DS (Biliopancreatic Diversion with Duodenal Switch).

Adjustable Gastric Band

AGB is a laparoscopic procedure, commonly called “lap-band”, “A band” or LAGB, which reduces the stomach size by placing an inflatable, bracelet-like, silicone band around the top part of the stomach, creating a small stomach pouch above the band, and leaving the rest of the stomach below. The device can be adjusted, according to the patient’s needs, by adding or removing sterile saline which is injected through a port under the skin.
Weight loss is explained by the ingestion of smaller amounts of food and restricting the emptying of the stomach through the band.
An important advantage of this procedure is that the food is digested and absorbed as it normally would.

Biliopancreatic Diversion with Duodenal Switch

BPD/DS is a complex bariatric surgery that consists of three main procedures:

• First, create a smaller, tubular stomach pouch by removing a wide part of the stomach (sleeve gastrectomy). This leads to satiety after a smaller meal, and encourages the patients to eat less;
• Second, the duodenum is divided past the stomach and the last part of the small intestine is brought up and connected to the newly created pouch, this way bypassing the duodenum and jejunum (first and medium part of the small intestine). The food is re-routed from three-fourths of the small intestine and most of the calories, nutrients, and vitamins are not absorbed. The distance between the stomach and the large intestine becomes much shorter;
• Third, the bypassed upper part of the small intestine is reconnected to the last part of the small intestine, so that bile and pancreatic juice, even if in small quantities, can eventually mix with the food stream. This results in significantly decreased absorption of calories and nutrients, especially protein and fat, leading to weight loss.

It is very important to note that even if most bariatric surgery is laparoscopic (mini-invasive), these procedures have a big impact on the patient’s life that may cause health issues that need to be monitored.

BS procedures have some advantages:

• Leads to significant long-term weight loss;
• Reduces the amount of food that can be eaten;
• This leads to changes in gut hormones that reduce appetite and improve satiety;
• Involve a short hospital stay;
• Some procedures are reversible and adjustable - AGB;

Disadvantages:

• Postoperative complications;
• Can lead to long-term nutrient, vitamin, and mineral deficiencies, especially vitamin B12, fat-soluble vitamins, iron, calcium, zinc, and folate;
• Requires long-life vitamin/nutrient supplements;
• Requires strict adherence to dietary regimen;
• Requires follow-up compliance;
• Some procedures are non-reversible - the sleeve;
• AGB - requires a foreign object to remain in one’s body and can possibly result in band slippage or stomach erosion (in rare cases) as well as some mechanical problems with the band.

Read about a real Patient's Bariatric Surgery Transformation and get more insights on Gastric bypass surgery.