Definition
Obesity has become a serious public health problem.
According to the latest information, in the United States 54% of citizens are overweight (i.e. they have a body mass index (BMI *) > 25), while 15% of people aged between 12 and 19 and 20% of the population as a whole are obese (BMI > 30). The percentage of people classified as obese has tripled in 20 years and obesity causes 300,000 deaths each year.
The basic therapeutic approach to obesity involves strict dietary measures coupled with a radical change in lifestyle habits (under medical supervision if necessary).
Unfortunately, the effects of this approach are often disappointing among the morbidly obese (BMI > 35), as they are transitory and reversible (yo-yo effect of diets). As a result, gastrointestinal surgery is becoming one of the main therapeutic options.
Bariatric surgery owes its rapid increase in popularity to patient demand and to technological advances in surgery. In particular operations using laparoscopic surgery, which does not involve opening the abdomen. This less invasive form of surgery reduces stress, cardiopulmonary morbidity and after-effects for the abdominal wall (abscesses and ruptures) and allows complications to be checked in a highly effective manner.
Operations are based on two principles: reducing gastric capacity (restriction), and reducing the absorption of high-energy food, such as sugars and fats (malabsorption).
*BMI (Body Mass Index) is an individual's body weight (in kg) divided by the square of his/her height (in metres). It is used to determine the extent to which someone is overweight. A normal BMI is 18 to 25.
Specific Interventions
A silicon band with an adjustable diameter is placed at the entry of the stomach (the cardia) directly under the distal end of the oesophagus. It creates a little pouch in which food is held up and passed slowly, as if going through an hourglass.
The patient can only eat small portions at each meal.
The system is controlled by the injection of a liquid in a little reservoir placed just under the skin that is connected to the inflatable chamber of the band.
The system is also called Laparoscopic Adjustable Band.
Feeding habits are changed by a simple mechanical reduction. The system is purely RESTRICTIVE. It is not suitable for sweet eaters, neither for grazing eaters.
It can be placed in patients with a BMI lower than 50 and who do not suffer from hiatal hernia or reflux.
The gastric bypass has become the gold standard in terms of weight-loss surgery. It allows the stomach to be bypassed.
A small pouch of stomach (created using the first few centimetres of the stomach wall) is connected directly to the small intestine. The small capacity of the pouch is responsible for creating the restriction effect. Food is not digested by digestive enzymes.
Sugar products are poorly tolerated when they come into direct contact with the small intestine, which encourages the patient to consume fewer products of this kind.
Patients quickly loose at least two thirds of their excess weight. This leads to an excellent quality of life, and the results are stable in the long term.
Gastric bypass patients spend a total of five days in hospital and the complication rate is approximately 4%.
The operation consists of removing a major part of the stomach leaving behind a gastric tube with reduced capacity. The course of the food is not altered but the eating capacity is seriously restricted.
The term "sleeve" refers to the reduced stomach taking on the shape of a sleeve.
This operation is only restrictive and suitable for big eaters (sportsmen or heavy labourers) whose increasing weight is in accordance with a reduction of physical activity. It is not suitable for grazing eaters and sweet eaters.
If a duodenal switch is required to be done in two separate steps, this can be applied as a first phase.
It is not suitable for a BMI higher than 50, or for patients with a hiatal hernia.
The capacity of the stomach is reduced in the same way as a sleeve opertation.
Then the small intestine is altered so that food is not digested in the duodenum by the secretion of bile (product of the liver) and the pancreas (enzymes for the digestion of proteins, fats and sugars).
The intestine is divided in two almost equal segments. The first segment (biliopancreatic) is kept intact as from the duodenum but the latter is separated from the stomach and is closed off. The second half is reconnected directly to the gastric tube (sleeve). This is the food segment because the food in-take passes through it. The two segments are reunited in such a way that food and digestive enzymes are mixed only in one metre of the small intestine (common limb) producing reduced digestion in a short intestinal fraction.
This typical mixed operation (restrictive by the sleeve and malabsorptive by the shortening of the intestine to one metre through which food and digestive enzymes pass) is suitable for patients with a very high BMI (higher than 50) or for those who could not accept psychologically to eat reduced quantities of food.
The malabsorption means lifelong taking of vitamin supplements, if not, dangerous deficiencies occur.
