Concepts of Bariatric Surgery
Obesity treatment is clinical and therefore based in the nutritional, physical and psychological reeducation, which we call triple reeducation. It must be carried on for life. Medication has only supporting value and should only be prescribed by a specialist as a complementary therapy, since it presents side effects.

Worldwide statistics studies have shown that clinical treatment works well in patients with BMI less than 40 kg/m2. However, severely obese patients do not present good results with clinical treatment, since they lose little weight and regain weight easily. So we consider the BMI less than 40 kg/m2 being the limit for clinical treatment. Patients with greater BMI, called morbidly obese, fall into another category.

Back in time, morbidly obese sufferers were not offered any satisfactory treatment and they kept putting on weight until they died due to comorbidities. In this scenery, in 1952, a new surgical treatment proposal was presented in the United States, and thus a new medical specialty was created, called Bariatric Surgery.

Note: Before continuing, we suggest the reading of Digestive Tube, Origin of Obesity and Characteristics of Obesity.

The purpose of that specialty is to cause a healthy weight loss, and avoid weight regain. There are many kinds of surgery, according to their mechanism of action:
• Restriction of food intake;
• Reduction of hunger sensation in brain level, in order to cause gastric satiety;
• Restriction of fat and carbohydrate absorption (disabsorption).

Restriction of Food Intake
Historically, there were many attempts to restrict food intake, for instance, by wiring the teeth to keep the mouth shut, or by narrowing the stomach with a compression belt, modifying the stomach into an hourglass shape, so only much smaller amounts of food could be ingested per minute. Another option was to place a plastic balloon inside the stomach to occupy part of the space designed for food. Those are called restrictive techniques.

The major issue with those techniques is that food is 100% absorbed between duodenum and proximal jejunum, and the terminal small intestine does not receive any food, therefore it does not send a message to the brain to stop eating (see Digestive Tube). The patient is still very hungry. It is a struggle between the hunger instinct and a mechanical narrowing.

Reduction of Hunger and Gastric Satiety
According to Digestive Tube and Origin of Obesity, it is clear that food goes from mouth to anus, like a road. Let us suppose that is a 100 kilometer road. In the space between the 10th and 20th kilometers is the duodenum and proximal jejunum, that is the high absorptive capacity intestine, an absorbent sponge. The majority of nutrients are absorbed into the blood from that space. The rest of the food that was not absorbed keeps going down the road through peristalsis. When the nutrients get 80 kilometers away, in the terminal ileum, they help the intestine to produce hormones that make the body stop eating, by warning the brain that there is already too much food. Those hormones stimulate the satiety center in the hypothalamus, and there is no more hunger. The same hormones make the same food that has arrived 80 kilometers away go in reverse (antiperistalsis), towards the stomach, causing fullness sensation. Moreover, those hormones, produced in the terminal ileum, improve the insulin production by the pancreas (incretin effect). This aspect is well reported in Surgery for Diabetes.

Unfortunately, modern food (rich in carbohydrates and poor in fiber contents) is easily digested. Maybe 90% of this food is absorbed in the space between the 10th and 20th kilometer (duodenum and proximal jejunum) of the road, therefore there are no "leftovers" to go to the 80th kilometer, the terminal small intestine. People eat, but the brain does not receive information to stop eating. Besides, the stomach does not get uncomfortable, and accepts more food ingestion.

There is a way to interrupt this vicious circle. We perform a detour in the road so that the food does not go in the space between the 10th and 20th kilometer, then the "sponge" does not absorb the food, so it can go up to the 80th kilometer. The detour forces food to run the first 10 kilometers and "jump" the next 10 kilometers to continue the trajectory. In other words, we exclude only 10% of the road, i.e., food skips duodenum and jejunum. The "detour" is called duodenal-jejunal bypass. The food passes through 90% of the digestive tube and gets into the terminal small intestine (ileum), so that the patient is not hungry anymore, eats less and consequently loses weight. Those are Duodenal Exclusion Techniques.

This seems the ideal way of losing weight, because patient does not go through the struggle of food craving.

Types of Bariatric Surgery
Since 1952, surgeons have been developing techniques as described above, turning Bariatric Surgery as a medical specialty for more than 56 years.

Currently, there are 3 worldwide acknowledge surgical techniques:

A- Gastric Bypass

Developed in 1980, in the United States, by Dr. Mal Fobi and Dr. Rafael Capella, it is based in the duodenal exclusion. Acknowledged in the international community as "the gold standard" of Bariatric Surgery, it is the most utilized technique in the world. Perhaps, 70% of the Bariatric Surgery performed nowadays are Gastric Bypass. Patients that underwent this kind of technique, in 1980, say that they are not hungry, and the majority of them lost interest in food. Food is no longer their main source of pleasure.

The average weight loss is 40 up to 45% from the initial weight. The major weight loss is noticed in the first seven months after the operation (few patients keep on losing weight during 2 years after the surgery). We consider that this weight loss is enough to improve the clinical condition of the morbidly obese patient.

The quality of life of patients is good, because they usually do not present vomiting or diarrhea. There are some problems concerning anemia and osteoporosis, easily corrected with vitamins, iron and calcium ingestion.

The duodenal exclusion has an extra advantage, besides losing weight, patient gets better from diabetes type 2. Actually, most of the times, patients are cured, due to the improvement of pancreatic function, which increases the insulin production.

Another advantage is that there is no organ removal, so the surgery is totally reversible. If in the future, a new sort of procedure is proven to be more effective, we can reoperate and give the patient his/her original anatomy.

Finally, Gastric Bypass has been performed for more than 28 years and it is proven to be the most popular Bariatric Surgery. Time has approved this technique.

B- Adjustable Gastric Band

This technique consists in installing an adjustable inflatable band around the stomach. The belt promotes a stomach stricture, transforming it in an hourglass-shaped organ. Under the abdominal skin there is a button in which surgeon can inject or withdraw a sterile solution to expand more or less the inside diameter of the band, to increase or decrease the "hourglass" bore.

Whenever the ideal gastric stricture is found, the patient eats little and waits the food to pass through the stricture before he/she is able to eat again. So, meals are smaller and patient has a fullness sensation registered by the upper part of the hourglass.

The problem with this technique is that patient feels hungry. The food that goes into the stricture is absorbed by the "sponge" (duodenum and proximal jejunum), and does not get into the terminal ileum. So, intestine does not feel full and does not warn the brain (which would cause satiety). Consequently, patient ends up replacing meat and vegetables by carbohydrates since they turn into a paste-like texture, passing easier through the gastric stricture. Thence it follows that the technique instructs the hunger instinct to get around the constriction by eating sweets to supply the need, which may turn into a compulsion.

The weight loss is around 20% of the patient's initial weight, which is a modest loss for the morbid obesity sufferers.

The quality of life is decreased since patient vomits frequently. Another common complication from this procedure is that the stomach acid reflux goes back to the esophagus causing reflux esophagitis.

Also the patient has stomach prosthesis for life, and it is known that prosthetic devices can bring complications in the future.

This technique should only be applied to a few selected cases. It is estimated that only 10% of morbidly obese should undergo this sort of procedure. The problem lies in finding among 100 morbidly obese the ideal 10. It seems that the technique is unadvisable for sweet tooth women, and also for those whose BMI is greater than 45 kg/m2.

C- Disabsorptive

There are 2 disabsorptive techniques: Scopinaro and Duodenal Switch. Both aims to make the food to pass through only 30% of the digestive tube. The general idea is to make the fat and carbohydrates absorption difficult, but there is no harm to the protein absorption. There are no restrictions, so the patient eats as much as he/she pleases. If the patient chooses to eat protein, such as meat, he/she loses weight and has good quality life. However, if the patient chooses to ingest food with fat contents, he/she suffers with serious smelly diarrhea. That causes not only personal issues, but also professional ones, due to highly unpleasant odor, therefore the quality of life is considerably compromised.

Other complications that may occur:

• protein denutrition in patients who do not eat enough protein;
• hepatic cirrhosis;
• arthralgia.

The weight loss is greater than by Bypass Surgery, around 50% of initial weight. The quality of life is jeopardized by the eventual smelly diarrhea. Although denutrition and cirrhosis are rare, they can be very serious if they occur.

In order to undergo this technique patient should enjoy eating meat and be wealthy, since the postoperative period demands many tests and possible hospitalizations.

Bariatric Surgery - Final Considerations
For unknown (genetical, hormonal, psychological and market promotion) reasons, food is the greatest source of pleasure for the morbidly obese patients and the Bariatric Surgery ends up destroying that source. The Bypass procedure inhibits hunger and Gastric Band makes food intake harder. For that reason, patient must be prepared to "change pleasure source" after the operation. Before surgery, patient needs to be psychologically prepared to face the "searching for a new substituting pleasure".

Prior to the operation, patient's expectations must be adjusted as much as possible to reality to avoid postoperative disappointments, since many times patients have the illusion that by losing weight, they would save a failed marriage, or get a better job and so on.

Patient's family needs to be involved in the Bariatric Surgery preoperative process, since the sudden weight loss might cause negative emotions, such as jealousy and enviousness.


The multiple goals of Bariatric Surgery are:

• to avoid surgery complications;
• to lose at least 40% of the patient's initial weight;
• to keep the resulting weight loss for live;
• to avoid surgery side effects;
• to look after patient's happiness.

Bariatric Surgery is a different sort of operation. In classic surgery, such as the acute appendicitis removal, surgeon removes the problem from the patient's body even without the patient's cooperation. However, Bariatric Surgery by itself does not remove the problem, i.e., obesity. We do not know precisely what is the origin of obesity. It is a multidisciplinary pathology, which involves medical specialties, psychology, nutrition, physical therapy and others. We operate a healthy stomach and suture a normal intestine. The operation is the first step of a long weight loss pursuit. It is necessary that patient, surgeon, nutritionist, psychologist, physical therapist and every professional involved take charge of their role. Patient needs to follow precisely the multidisciplinary team's orientation in order to lose and maintain weight, avoid diseases and be happy.

The postoperative mortality is rare. It mostly happens to the super morbidly obese and the world mortality rate is around 0,6%. We believe that the risk of mortality is greater for the morbidly obese sufferers than for those who undergo Bariatric Surgery.