It consists of cutting the stomach from being bagpipe-shaped to banana-shaped. It is a much simpler technique than other interventions such as gastric bypass or bilio-pancreatic diversion, but in reality its working is complex through physiological, hormonal and metabolic mechanisms.
Traditionally and in a simplistic way, obesity surgeries have been considered as either “restrictive”, “derivative” or a mixture of both.
Restrictive surgeries limit the space to house food and derivatives or malabsorptives produce a reduction in the absorption of nutrients.
The gastric sleeve is not simply restrictive because although it reduces the capacity of the stomach by approximately 80%, it still leaves a capacity of about 250 cc, which supposes a volume much higher than the restriction produced for example by a by-pass in which reduces the stomach to just over 3% of its volume, that is, 20-60 cc (less than the volume of an egg)
In the gastric sleeve, by removing the gastric fundus, the hormonal mechanisms of hunger are modified and it is possible to reduce appetite, making hunger coincide with the capacity of the stomach and with the patient’s real feeding needs.
The gastric sleeve through complex hormonal and metabolic mechanisms achieves results equivalent to those of the by-pass, with a much greater gastric capacity and without the malabsorptive component. The stomach, although limited in volume, maintains its function like the rest of the intestine, which maintains its absorption capacity of all nutrients.
The gastric sleeve is indicated for patients with a BMI of more than 40 (morbid obesity) or patients with a BMI> 35 (obesity grade II) with some comorbidity such as diabetes, hypertension, etc … although in certain cases it can even be considered from BMI of 30 (obesity grade I)