Gastric bypass is also called gastric bypass. It is a mixed technique, both restrictive and malabsorptive, more effective in the long term than restrictive techniques alone. The Clínica Digestivo Médico Quirúrgica explains that it is a technique indicated as surgery for morbid obesity, in patients with a Body Mass Index (BMI) higher than 40kg/m2, although also in patients with failure of a restrictive technique, such as gastric banding or vertical gastrectomy.
How is the gastric bypass technique performed and what does it consist of?
The gastric bypass technique is performed laparoscopically, so it is a minimally invasive surgery, much more comfortable for the patient.
The surgical process of the gastric bypass consists of the section and stapling of the stomach (which has a capacity of two liters) to form a small gastric pouch (about 20-30 ml. capacity), where the food arrives. This pouch is the restrictive part of the intervention. To this small pouch is directly connected, with a mechanical suture, the small intestine, a union which is called “Y” gastrojejunal anastomosis.
The following image shows the procedure:
Functioning of the digestive system with gastric bypass and weight loss.
Once the procedure has been performed, the food passes directly from the small gastric pouch to a more distant portion of the small intestine. In this way, the passage of food through the rest of the stomach, duodenum and a large part of the jejunum is avoided. This is the malabsorptive part of the technique, which mainly affects fats, which are absorbed only in the presence of bile salts in the duodenum.
With gastric bypass there is a faster and more marked weight loss. This is due to food restriction by the small gastric pouch, malabsorption by the “Y” loop, an early gastric emptying syndrome in which sweet foods are rejected and a loss of appetite, due to a decrease in ghrelin.
Postoperative period after gastric bypass surgery
After gastric bypass surgery, the patient remains in the intensive care unit for the first 24 hours and is then transferred to the ward. On the third day after the surgery, the expert in general surgery and digestive system will perform an X-ray with oral contrast, to verify a correct gastrointestinal transit. If during this test there are no clinical warning signs, oral feeding with liquids is started on the fourth day.
If there are no complications, the patient is discharged on approximately the fourth day if the operation was performed laparoscopically. On leaving the hospital the patient is given gastric protection and preventive anticoagulants.
During the first week the patient should drink only liquids and, around two weeks after the operation, he/she should be monitored in consultation.
The patient should tolerate a semi-liquid diet during the following three weeks. Approximately one month after the operation, the patient can progressively resume a normal diet. The protein dose should be less than 50 grams per day and sugary drinks and foods should be avoided, due to the accelerated gastric emptying. Vitamin supplements, such as calcium, iron or vitamin B12, can also be administered thereafter.
Importance of an inter-consultation with Psychology and Endocrinology
When a patient is going to undergo surgery, it is recommended that they have an inter-consultation with Psychology and Endocrinology. The reason for this is the support that these professionals can give them, with the aim of making them feel accompanied in the recovery process, with the diet indications and, above all, to prevent any possible alteration.
Possible complications of gastric bypass surgery
As in any surgical intervention, it is a process not exempt of risks and complications, which can be:
- infection of the surgical wound
- bleeding
- leakage or dehiscence of the stapling line
- gastric fistula
- gastrojejunal anastomosis stenosis or enlargement