Currently, there are three types of obesity surgery:
- Restrictive: they make it possible to reduce the volume of the stomach, so that weight loss occurs as a result of the decrease in the amount of food the patient ingests.
- Malabsorptive: this type of surgery causes a malabsorption of food in the intestine, which is eliminated through the feces.
- Mixed: mixed techniques combine restrictive and malabsorptive procedures.
Pure restrictive techniques
Pure restrictive techniques include gastric banding, vertical gastroplasty, horizontal gastroplasty and tubular or sleeve gastrectomy. This last one is one of the ones that allows to obtain better results and the one that has managed to displace the previous ones. In fact, the previous ones are almost not used nowadays, because of the poor results in weight loss and the difficulty to regulate the amount of intake due to frequent vomiting.
Regarding tubular gastrectomy, nowadays, 15 years after its development, it is the second most used technique in the United States and Spain to treat morbid obesity and metabolic syndrome. This fact is due to the fact that it is having very good results in the correction of the concomitant pathology, and this does not occur with the other restrictive techniques. On the other hand, it is also important to point out that this is the procedure with the fewest complications and the least mortality, so it is the safest. Nowadays, 45% of all obesity surgeries are performed in Tubular Gastrectomies.
Malabsorptive techniques
This type of techniques have a low restrictive component, so that the patient can eat almost normally. However, part of the nutrients, especially fat, are not metabolized or absorbed.
Among the malabsorptive techniques currently available, the bilio-pancreatic diversion and duodenal crossover stand out. These require an exhaustive follow-up due to protein loss, decalcification and the need for supplementation to avoid the creation of a new patient due to the deficiencies that may appear. Among them, the one with the least side effects is the one performed with a long food loop of about 3 meters with a common loop of 1 meter. It is performed in approximately 10% of all obesity surgeries, preferably in a body mass index over 50.
Mixed techniques
Among the mixed techniques we find the different variants of the gastric bypass, the short gastric bypass, which has been discontinued because the long gastric bypass is much more effective. This is the most used technique at present, together with the Gastric Sleeve (45% in both cases). However, it is true that its effect on weight loss is less lasting than in the bilio-pancreatic diversion.