surgical treatment of obesity

Also called bariatric surgery, and is divided into three groups: restrictive procedures, malabsorptive procedures and mixed procedures.
For individuals who have been unable to achieve significant weight loss through diet modifications and exercise programs alone, bariatric surgery may help to attain a more healthy body weight. There are a number of surgical options available to treat obesity, each with its advantages and pitfalls. In general, bariatric surgery is successful in producing (often substantial) weight loss, though one must consider operative risk (including mortality) and side effects before making the decision to pursue this treatment option. Usually, these procedures can be carried out safely.
Surgery should be considered as a treatment option for patients with a BMI of 40 kg/m 2 or greater who instituted but failed an adequate exercise and diet program (with or without adjunctive drug therapy) and who present with obesity-related comorbid conditions, such as hypertension, impaired glucose tolerance, diabetes mellitus, hyperlipidemia, and obstructive sleep apnea. A doctor–patient discussion of surgical options should include the long-term side effects, such as possible need for reoperation, gallbladder disease, and malabsorption.
Patients should be referred to high-volume centers with surgeons experienced in bariatric surgery.


1- Restrictive procedures:

A) Vertical Banded Gastroplasty

In the vertical banded gastroplasty, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach.
The purpose of VBG is the treatment of morbid (unhealthy) obesity. It is one of the first successful procedures in bariatric surgery. VBG was developed in its present form in 1982 by Dr. Edward E. Mason, a professor of surgery at the University of Iowa.

B) Adjustable Gastric Banding

Also called Kuzmak's restrictive silastic banding is a restrictive device implanted using bariatric surgery. The gastric band is an inflatable silicone device which is placed around the upper portion of the stomach, usually by laparoscopic surgery.
it is not an easy option for obesity sufferers. It is a drastic step, carrying the usual risks and pain of any major gastrointestinal surgical operation. Some patients who undergo such operation lose more than 60% of excess body weight. Typically, patients who undergo adjustable gastric banding procedures, like Realize-Bandor Lap-Band lose less weight over the first 3.5 years than those who undergo gastric bypass, or other surgeries such as Biliopancreatic Diversion (BPD) or Duodenal Switch (BPD-DS).
The placement of the band forms a stoma, or small pouch at the top of the stomach which holds approximately 0.1 to 0.2 kilo grams of food per meal. such pouch is filled with food rapidly and the band makes the passage of food from the pouch to the lower part of the stomach is slow. As the upper part of the stomach is full, the message to the brain is that the whole stomach is full and this makes the person hungry less often & feel full more rapidly and for a longer period of time& eat smaller amounts & lose weight over time.
The band is inflated & adjusted by a small access port which is placed just underneath the skin. Saline solution is introduced into the band through that port. A specialized non-coring needle is used in order to avoid the damage to the port membrane. When the saline solution is introduced into the band it expands, causing pressure around the outside of the stomach. Gastric Bands usually can hold 8 to 10 cc of saline solution. This reduces the size of the passage between the pouch and the lower stomach & restricts the movement of food.

C) Sleeve Gastrectomy

it is an operation in which the left side of the stomach ("greater curvature") is removed surgically . This causes a new stomach which is roughly shape and the size of a banana. as this operation does not involve any reconnecting or "rerouting" of the intestines, it is simpler than the duodenal switch or the gastric bypass . Unlike the LAP-BAND® procedure, the implantation of an artificial device inside the abdomen is not required .
In some cases, the sleeve gastrectomy is performed as a definitive therapy for obesity. For certain patients, in particular those with a body mass index greater than 60, the sleeve gastrectomy may be the first part of a 2-stage operation, which is a multi-step operation like the gastric bypass or the duodenal switch is broken down into 2 simpler and safer operations. In the first stage, a sleeve gastrectomy is performed. This allows losing 80 to 100 pounds or more, which will make the second part of the operation substantially safer.
The second stage operation is usually performed 8 to 12 months after the first. The "sleeve" stomach is converted into a formal gastric bypass or duodenal switch. This will permit additional weight loss and will provide a much more permanent result than sleeve gastrectomy alone.
The sleeve gastrectomy works through 2 mechanisms:
• It makes the stomach smaller, so you feel full after eating a smaller meal.
• The fundus of the stomach is removed. This is the area that secretes ghrelin, a hormone that makes you feel hungry. So, the sleeve gastrectomy may help you to feel less hungry through a hormonal mechanism.
The sleeve gastrectomy has a number of advantages over other bariatric procedures:
• It does not require disconnecting or reconnecting the intestines
• It is a technically simpler operation and safer than the gastric bypass or the duodenal switch. It may be used as the first stage of a 2-stage operation.

2- Malabsorptive Procedures:

Predominantly malabsorptive procedures, although they also reduce stomach size, these operations are based mainly on creating malabsorption. They are no longer used due to problems with malnourishment. The goal of malabsorptive surgical procedures is to decrease the effective length of small intestine through which food must pass, thereby reducing the absorption of nutrients and calories and inducing weight loss. Biliopancreatic diversion, with or without duodenal switch, is the primary malabsorptive procedure performed today.

A) Biliopancreatic Diversion

Also known as Scopinaro procedure. It has been replaced with the duodenal switch, also known as the BPD/DS. Part of the stomach is resected, creating a smaller stomach (however after a few months the patient can eat a completely free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum. This results in around 2% of patients, in severe malabsorption and nutritional deficiency that requires restoration on the normal absorption.
The malabsorptive element of BPD is so potent that those who undergo the procedure must take vitamin and dietary minerals above and beyond that of the normal population, those who do not, run the risk of deficiency diseases such as anemia and osteoporosis Because gallstones are a common complication of rapid weight loss following any type of weight loss surgery, some surgeons may remove the gallbladder as a preventative measure during BPD. Others prefer to prescribe medication to reduce the risk of post-operative gallstones. Far fewer surgeons perform BPD compared to other weight loss surgeries, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients.

B) Jejunoileal Bypass

3- Mixed Procedures:

Mixed or combination procedures have both a restrictive and malabsorptive component, meaning that they limit food intake while also decreasing absorption of nutrients within the body.

A) Gastric bypass Gastric bypass procedures (GBP) :

are any of a group of similar operations used to treat morbid obesity—the severe accumulation of excess weight as fatty tissue—and the health problems (co-morbidities) it causes.
Roux-en-Y gastric bypass (RYGB) is primarily a restrictive procedure, but also has a malabsorptive element, making it more successful than a solely restrictive surgery.
The surgeon creates a small stomach pouch by dividing the stomach, and attaches it to the small intestine. The pouch is only able to hold about an ounce of food, causing a feeling of fullness after consuming a very small amount; over time, the pouch stretches to hold about one cup. Additionally, the body absorbs fewer calories since food bypasses the majority of the stomach as well as the upper small intestine (duodenum). This kind of new intestinal arrangement (Roux-en-Y) seems to cause decreased appetite and improved metabolism by changing the release of various hormones.
Complications of gastric bypass can vary based upon the surgical approach; some are seen during the early postoperative period, while others may arise weeks to months following the surgery.
Some of the early complications include peritonitis (infection of the abdominal lining) from leaks at the site of staples or sutures, gastrointestinal bleeding, narrowing of the passage between the stomach and intestine, or ulcers. Patients may also experience vitamin deficiencies due to the malabsorptive component of the procedure.

- Gastric bypass ; Roux en-Y (proximal) :

It is the operation that is least likely to cause nutritional difficulties , The small bowel is divided about 450 mm (18 in) below the lower stomach outlet, re-arranged into a Y-configuration, to allow the outflow of food from the small upper stomach pouch , via a "Roux limb". In the proximal version, the Y-intersection is formed near the upper (proximal) end of the small bowel. This Roux limb is formed with a length of 80 to 150 cm (30 to 60 inches), to preserve most of the small bowel for absorption of nutrients. very rapid onset of a sense of stomach-fullness, followed by a feeling of growing satiety, or "indifference" to food is experienced by the patient , shortly after the start of a meal.

- Gastric bypass ; Roux en-Y (distal):

The normal small bowel is 6000 to 10000 mm (20 to 33 feet) in length. As the Y-connection is moved farther down the gastrointestinal tract, the amount of bowel capable of fully absorbing nutrients is progressivelydecreased, in pursuit of greater effectiveness of the operation. The Y-connection is formed much closer to the lower (distal) end of the small bowel, usually 1000 to 1500 mm (40 to 60 inches) from the lower end of the bowel, leading to decreased absorption (mal-absorption) of food, primarily of fats and starches, but also of various minerals, and the fat-soluble vitamins. The unabsorbed starches and fat pass into the large intestine, where bacterial actions may cause them to produce irritants and malodorous gases. such increasing nutritional effects are traded for a relatively modest increase in total weight loss.

- Loop Gastric bypass (Mini-gastric bypass) :

The first use of the gastric bypass, in 1967, used a loop of small bowel for re-construction, rather than a Y-construction as is prevalent today. though it is simpler to create, such approach allowed bile and pancreatic enzymes from the small bowel to enter the esophagus, sometimes causing severe inflammation and ulceration of either the stomach or the lower esophagus. If a leak into the abdomen takes places , such corrosive fluid can lead to severe consequences. a lot of studies show the loop reconstruction works more safely when placed low on the stomach, but can cause disaster when placed adjacent to the esophagus. so , even nowadays thousands of loops are used for general surgical procedures like stomach cancer, ulcer surgery and injury to the stomach, however , bariatric surgeons abandoned use of the construction in the 1970s, as it was recognized that its risk is not justified for weight management.
The Mini-Gastric Bypass, which uses the loop reconstruction, has been suggested as an alternative to the Roux en-Y procedure, due to the simplicity of its construction, which reduced the challenge of laparoscopic surgery.

Risks of Gastric Bypass Surgery:

- Pouch stretching (stomach gets bigger, and it stretches back to its size before surgery)
- Band erosion (the band which is closing off part of the stomach disintegrates)
- staple lines are brokendown (band and staples fall apart, reversing procedure)
- stomach contents leak into the abdomen (this is dangerous because the acid can eat away other organs)
- Nutritional deficiencies lead to health problems.
Gastric bypass surgery also might cause "dumping syndrome," inwhich the stomach contents move too fast through the small intestine. Symptoms involves sweating , nausea, weakness, faintness, and diarrhea after eating, besides the inability to eat sweets without becoming very weak. Gallstones can takesplace because of rapid weight loss. They can be dissolved with medical treatment taken after the surgery.

B) Sleeve gastrectomy with duodenal switch

The part of the stomach along its greater curve is being resected. The stomach is "tubulized" with a residual volume of about 150 ml. such volume reduction provides the food intake restriction component of this operation. such type of gastric resection is fun and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine. The duodenum and the upper part of the small intestine are reattached to the rest at about 75-100 cm from the colon.
A two-stage procedure is performed: the first is a sleeve gastrectomy, and the second is a conversion into a gastric bypass or duodenal switch. Patients usually lose a large quantity of their excess weight after the first sleeve gastrectomy procedure alone, but if weight loss ceases, the second step is performed.
For patients that are obese but not extremely obese, sleeve gastrectomy alone is a suitable operation with minimum risks. Some surgeons even prefer it over gastric banding, because it eliminates the need of having to insert a foreign body. The sleeve gastrectomy currently is acceptable weight loss surgery option for obese patients as a single procedure. Most surgeons prefer to use a bougie between 32 - 40 Fr with the procedure and the approximate remaining size of the stomach after the procedure is about 2 ounces.

C) Implantable Gastric Stimulation

a device similar to a heart pacemaker is implanted by a surgeon, the electrical leads stimulate the external surface of the stomach, such procedure is being tested in the USA. This device works on either or both of the following: stimulation of Enteric nervous system or Disruption of motility cycle .
The aim of both techniques is to increase the duration of satiety and there by making the patient consume less. The electrical stimulation is thought to modify the activity of the enteric nervous system in the stomach, which is then interpreted by the brain as a sense of satiety, or fullness. Early evidence suggests that it is less effective than other forms of bariatric Surgery.
Besides the various types of surgeries, there are also two other techniques with which doctors can choose to perform each surgery. They are laparoscopic and open bariatric surgeries.

Open Bariatric Surgery:

It requires one large incision that begins directly below the patient's breastbone and ends just above the navel. Open bariatric surgery is associated with a longer recovery period.

Laparoscopic Bariatric Surgery:

it involves making several small incisions and performing the operation via video camera. the device used to capture the video, called A laparoscope , is inserted through an abdominal incision , providing the bariatric surgeon a magnified view inside the abdomen, which allowes the operation to be performed using special surgical instruments and a television monitor.
The advantages of the laparoscopic bariatric surgery include less post-operative pain, a shorter recovery period and less extensive scarring.

New technique:

A newer technique in obesity surgery is known as gastric pacing. In which , electrodes are implanted in the muscle of the stomach wall which deliver a mild electrical current. These electrical impulses regulate the pace of stomach contractions so that the patient feels full on smaller amounts of food. Preliminary results show that gastric pacing is both safe and effective.