Gastric Bypass

Gastric bypass is one of the longest-established methods in obesity surgery. Its most common form is called “Roux-en-Y gastric bypass”. In the operation, a small gastric pouch (a new stomach section about the size of an egg) is created from the upper part of the stomach, and this pouch is connected to a part of the small bowel further along.

The operation therefore works in two ways: thanks to the small gastric pouch, a feeling of fullness comes with less food, and because a part of the small bowel is bypassed, the absorption of some of the nutrients taken in is reduced. In addition, after the operation changes are seen in some gut hormones related to appetite and blood sugar regulation.

Its main difference from sleeve gastrectomy (gastric sleeve) surgery is this: in sleeve gastrectomy, only part of the stomach is removed to reduce its volume; in gastric bypass the stomach is not removed, a small pouch is created and the route of the bowel is rearranged. Which method is suitable is decided jointly according to the person’s health, accompanying diseases and the outcome of the surgical assessment.

Gastric bypass is an option considered in patients with obesity in whom diet, exercise and medication alone have not achieved sufficient results. The generally accepted criteria are:

• People with a body mass index (BMI) of 40 or above,
• People with a BMI of 35 or above who have an additional obesity-related condition such as type 2 diabetes, hypertension (high blood pressure) or sleep apnoea.

Particularly in patients with type 2 diabetes or marked reflux symptoms, gastric bypass may be considered as a first option. The decision to operate is not made at a single examination; it is taken jointly at the end of a multidisciplinary preparation process that includes endocrinology, psychiatry/psychology, nutrition and anaesthesia assessments. It is important to determine the suitable method for you in discussion with your doctor.

The operation is performed under general anaesthesia and today mostly by the laparoscopic method (keyhole, with small incisions). A camera and surgical instruments are passed through a few small openings made in the abdomen.

• A small gastric pouch is created from the upper part of the stomach.
• The small bowel is divided at a certain point and its lower end is connected to this new pouch.
• In this way, food passes into the small bowel without going through most of the stomach and the duodenum (the first part of the small bowel).

The operation usually takes a few hours. Because the incisions are small with the keyhole method, pain is mostly less and the return to daily life is relatively quicker. Rarely, if technically necessary, it may be required to switch to open surgery.

As with any operation, gastric bypass carries some risks. Some of these may appear in the early period, others months or years later:

• Bleeding, wound infection and problems related to anaesthesia,
• Leak along the staple lines (seepage from the connection sites),
• Blood clot formation in the leg veins and the clot travelling to the lungs (embolism),
• Dumping syndrome: symptoms such as palpitations, sweating, weakness and diarrhoea, especially after sugary foods,
• Ulcer or narrowing at the connection site,
• Internal hernia (the bowel becoming trapped inside the abdomen) and the resulting abdominal pain,
• In the long term, vitamin and mineral deficiencies (iron, B12, vitamin D, calcium, folic acid).

Because reduced absorption is part of how this operation works, the risk of vitamin and mineral deficiency is generally more marked than with sleeve gastrectomy. For this reason, regular blood tests and taking the recommended supplements without interruption should be seen as an integral part of the operation. If symptoms such as severe abdominal pain, fever, vomiting or shortness of breath occur, you need to contact your doctor without delay.

The hospital stay is usually a few days; this period may vary according to the person’s general condition. Starting to walk early after the operation is important for reducing the risk of clots.

Eating is progressed in stages with the guidance of a dietitian:

• Clear fluids in the first days,
• Then thick fluids and puréed foods,
• Within a few weeks, soft foods and a gradual transition to a normal diet.

Small portions, eating slowly and chewing well, and taking fluids at times separate from meals are among the basic rules of this period. People with desk jobs can generally return to work within a few weeks; for jobs requiring heavy lifting this period may be longer.

Follow-up is lifelong. Follow-up examinations and blood tests are done more often in the first year and at regular intervals thereafter. Monitoring vitamin and mineral levels and continuously taking the supplements your doctor recommends are of great importance for preventing anaemia, bone thinning (osteoporosis) and problems related to the nervous system.