The gastric bypass is a surgical procedure in obese patients that is used to bypass and thus exclude large parts of the stomach and the small intestine from the digestive process. With a small remaining stomach the patients feel satiety even after a very limited amount of food. The result is a fast and pronounced weight loss.
Gastric bypass (more precisely: Roux-en-Y gastric bypass) is a very common obesity surgery used to reduce weight. It is named after the Swiss surgeon César Roux, who developed the basic technique for the intervention. The "Y" represents the Y-shaped diagram of the way the intestinal sections are joined together.
The success of a gastric bypass surgery is based on two principles:
The weight loss after a gastric bypass surgery is dramatic and reliable, but it is accompanied with some lifelong restrictions: Patients with a Reoux-en-Y-bypass may eat only very small portions, because after the operation the remaining stomach ("stomach pouch") has a very small volume. The poor nutrient utilization means that patients have to take life-long dietary supplements and vitamins (especially vitamin B12, trace elements and protein preparations) to avoid deficiency symptoms. Some of the nutrients remain undigested causing fermentation processes in the colon. However, the operation cannot be reversed after a successful weight reduction.
Any pathological changes in the stomach need to be ruled out before the operation. This makes necessary a stomach examination for diseases such as gastric mucosal inflammation or gastric ulcers and for possible bacterial colonization with "Helicobacter pylori", which can cause gastric ulcers. In addition to a gastroscopy and the examination of the gastric juices, an ultrasound of the upper abdomen is also used to detect gallstones. These are removed in the course of gastric bypass surgery as they can lead to inflammation of the gallbladder and bile duct.
The gastric bypass surgery lasts about 90 to 150 minutes depending on the patient and is performed under general anesthesia. The surgery usually requires a hospital stay of about one day before the operation (surgical and anesthesia preparation) plus five to seven days after it. After the gastric bypass surgery, you will not be able to work for three weeks.
Gastric bypass is now performed almost exclusively using the so-called minimally invasive surgery. This technique, also known as the keyhole method, does not require a large abdominal incision. Instead, the instruments and a small camera are introduced into the abdominal cavity through several two centimeters long skin cuts. Minimally invasive operations generally have lower surgical risk compared to open operations and are therefore particularly suitable for obese patients who are already more vulnerable to complications during and after surgery.
The gastric bypass is suitable for people with a body mass index (BMI) of more than 40 kg/m² (Obesity Grade III or morbid obesity). In any case, the condition for a gastric bypass surgery is that all non-operative measures were not sufficiently successful even after six to twelve months. These measures include, for example, professional nutritional advice, exercises and behavioral therapy (multimodal concept for obesity, MMC).
To have a gastric bypass performed you should be at least 18 and not more than 65 years old. However the intervention is possible in younger or older people in individual cases. Gastric bypass surgery is particularly recommended for people whose excess weight is caused by consumption of rich in calories food (sweets, fats) and drinks. This type of food is broken down badly, and the body can utilize it only to a small extent storing it as body fat.
If metabolic diseases, such as diabetes mellitus, hypertension or a sleep apnea syndrome, are already caused by obesity, a gastric bypass surgery can already be performed in patients with a BMI of 35 kg/m².
Various physical and mental illnesses prohibit an obesity operation such as gastric bypass. A gastric bypass surgery cannot be performed after previous surgeries or in case of stomach malformations, gastric ulcers and addictions, as well as untreated eating disorders such as binge eating or bulimia. Pregnant women also have to forgo gastric bypass surgery.
Gastric bypass is a very effective procedure, even though only few patients achieve normal weight (BMI ≤ 25 kg/m²). Studies have shown that in the long term a weight loss of about 60 to 70 percent of the excess weight is possible with a gastric bypass, i.e. the amount of weight that separates obese patients from the people with normal weight.
The weight loss after a gastric bypass operation has not only purely cosmetic effect, it also favorably impacts the metabolism. For example, in many cases, an existing diabetes mellitus is greatly improved and sometimes even cured. In many cases, blood glucose levels fall short after the operation, although the patient has not yet lost much weight. The reasons for this are yet unclear. It is suspected that various hormonal changes are set in motion by the operation (for example, such hormones as ghrelin, glucagon, GIP, etc.), which favorably affects the metabolism.
Since the gastric bypass surgery combines two principles (restriction and malabsorption, see above), the procedure is extremely effective even if the patient's obesity is caused by excessive intake of liquid or soft high calorie food. For these so-called "sweet-eaters" the sole reduction of the stomach volume achieved through a gastric banding, gastric balloon or sleeve gastrectomy, would not be sufficient.
Some side effects are associated with gastric bypass. Their strength differs in each individual case and therefore cannot be predicted. The most important side effects:
Gastric bypass is a large abdominal surgery that greatly alters the normal anatomy of the gastrointestinal system. In principle, surgical risks are low, but complications cannot be ruled out as with any surgical procedure. Non-specific surgical risks include:
In order to avoid digestive problems people with gastric bypass must follow these dietary rules for their whole life:
The cost of a gastric bypass differs considerably depending on the clinic. It ranges approximately between 6,500 and 15,000 euros.