Introduction
Gastric bypass is the most common operation in the context of obesity surgery (= surgery for overweight). As the name suggests, the aim of this operation is to support weight loss in severely overweight patients by means of “stomach reduction”. However, this surgical procedure is not considered the method of choice, but is rather used when all other attempts at weight reduction have been unsuccessful.
How does the gastric bypass work?
During gastric bypass surgery, the major part of the stomach is “paralyzed” by passing the food chyme from the stomach entrance directly into the small intestine. This means that a small part of the stomach remains and the digestive juices of the stomach are not lost. The smaller remaining stomach has a volume of up to 50ml and with this smaller volume it acts as a kind of “food brake”.
Preliminary investigations
The operation to create a gastric bypass is particularly suitable for overweight patients who either have a BMI of >40 (grade 3 obesity) or a lower BMI, but also have other diseases such as diabetes mellitus, sleep apnea or heart disease. As a rule, gastric bypass surgery is only used if conservative measures (nutritional advice and change of diet, physical activity, etc.) have been attempted over a certain period of time to reduce weight and have been unsuccessful.
In some cases, however, e.g. with BMI >50, a gastric bypass operation can be performed directly without previous conservative therapy attempts. Before surgery, the suitability for surgery is therefore checked in a detailed physical examination and a detailed medical history. A short check of the stomach for pathological changes such as tumors, ulcers or inflammations is performed by means of a gastroscopy. An ultrasound examination of the (upper) abdomen is also performed, with special attention to gall bladder problems such as gallstones, which can be removed directly during the operation. Both examinations are necessary, since the altered anatomy after the operation makes a gastroscopy of the original stomach and the removal of gallstones impossible.