Biliopancreatic diversion

What is biliopancreatic diversion?

By the term “biliopancreatic diversion” is meant that the digestive secretions of bile (bilis) and pancreas (pancreas) are fed to the diet porridge only in the lower part of the small intestine. As a result, the breakdown of nutrients is hindered and they are absorbed only in significantly smaller amount from the small intestine into the blood.

Biliopancreatic diversion usually leads to a particularly significant weight reduction in patients with obesity. Internationally, biliopancreatic division is the standard procedure, but has barely gained acceptance in Germany.

What happens through biliopancreatic diversion?

The principle of action is based primarily on malabsorption intentionally caused by the operation – the technical term for poor uptake of nutrients from the intestine. Normally, in the duodenum, the chyme that is coming from the stomach mixes with the digestive enzymes from the pancreas and gallbladder. The nutrients are thereby split and can now be absorbed by the intestinal mucosa and passed into the bloodstream.

However, biliopancreatic diversion first introduces them much further down the small intestine. Only from here mix so food porridge and digestive juices. Thus, only a short section of the intestine and much less time are available for the breakdown and absorption of food – a large part of the nutrients migrates undigested in the large intestine and is excreted in the stool.

However, the weight reduction does not just result from malabsorption alone. The second principle of action is the so-called restriction: In biliopancreatic division, among other things, the stomach is significantly reduced. Due to the reduced stomach volume (restriction) one is much faster fed and therefore eats less.

Operating procedure for biliopancreatic diversion

Basically, one differentiates between two variants of the operation: the sole biliopancreatic diversion (BPD) and the biliopancreatic diversion with duodenal switch (BPD-DS). In BPD, the stomach is reduced to a volume of about 250 to 500 milliliters. In the case of BPD-DS, on the other hand, the stomach is reduced to a so-called “stomach sleeve” with a volume of only about 100 to 120 milliliters. Thus, the restriction in BPD-DS is even more pronounced than in the case of BPD alone. Another advantage is that with the BPD-DS also the Magenpförtner (pylorus) is maintained. The chyme thus does not pass unhindered from the residual stomach into the intestine, but is released more slowly and continuously through the pylorus into the intestine. This significantly reduces the risk of a so-called dumping syndrome (see below).

Preparing for biliopancreatic diversion

Before the procedure, a gastroscopy is important to rule out serious diseases of the stomach and duodenum. An ultrasound of the abdomen should also be performed in order to detect any existing bile drainage disorders – such as gallstones. If gallstones are discovered, the gallbladder is usually removed as a precaution during biliopancreatic diversion, since later, during the intended weight loss, further stones may quickly form, which then very often lead to inflammation of the gallbladder and bile duct. In most cases, an electrocardiogram (ECG) and a pulmonary function examination are also necessary before the operation.

Expiration of the operation

Biliopancreatic diversion is now predominantly performed as a minimally invasive operation. In this process, also referred to as “keyhole technique”, no large abdominal incision is required. Instead, the surgical instruments and a small special camera are introduced into the abdomen via several small incisions. Minimally invasive surgery generally has a lower surgical risk than open surgery and is therefore particularly suitable for obese patients who already have a significantly increased surgical risk.

Biliopancreatic diversion proceeds in several surgical steps. Under general anesthesia, the surgeon inserts the instruments and a camera with light source into the abdominal cavity through several skin incisions. During the operation, gaseous carbon dioxide is also introduced into the abdominal cavity, so that the abdominal wall lifts slightly from the organs and the surgeon has better visibility and more space in the abdominal cavity.

Now the stomach is separated just below the esophagus. So only a small remaining stomach (gastric pouch) remains at the end of the esophagus. The remaining stomach portions are removed. In biliopancreatic diversion with a duodenal switch, a so-called tubular stomach with an even significantly smaller volume is deviated instead of the gastric pouch.

Next, the surgeon cuts the small intestine about 2.5 meters before the onset of the colon. The lower part is now pulled up and sewn directly to the stomach pouch or the tube stomach. The upper small intestine part has no connection to the stomach and will serve in the future only to transport the digestive secretions of bile and pancreas. He is now passed into the small intestine about 50 centimeters above the colon and sutured.

The common piece of small intestine, in which the food particles and the digestive juices mix, is thus instead of several meters only about half a meter long. Since this is no longer sufficient for a complete breakdown and absorption of the food components, these are predominantly undigested passed into the large intestine, which in turn absorbs hardly any nutrients. Because it serves above all the thickening of the digested food.

Duration of surgery, hospitalization and incapacity for work

Biliopancreatic diversion lasts about two to three hours and is always performed under general anesthesia. The surgery usually requires a hospital stay of about eight days – one to prepare and seven to close medical observation after the procedure. On average, about three weeks after the operation, a return to work is possible if the procedure is uncomplicated.

For whom is biliopancreatic diversion suitable?

Biliopancreatic diversion is a procedure for people with obesity and a body mass index (BMI) of ≥ 40 kg / m² (Grade III obesity). If there are already metabolic diseases such as diabetes, high blood pressure or a sleep apnea syndrome due to the excess weight, biliopancreatic diversion may be useful from a BMI of 35 kg / m².

The prerequisite for biliopancreatic diversion and all other procedures of obesity surgery is that all non-surgical measures have not been successful enough for six to twelve months. These measures include professional nutritional counseling, exercise training and behavioral therapy (so-called multimodal concept for obesity). For biliopancreatic diversion, one should be at least 18 years old and at most 65 years old, although the operation in individual cases is also possible in younger or older people.

In people with extreme obesity (BMI> 50 kg / m²), the operation is sometimes divided into two operations: First, only the tube stomach is created. This is to reduce the weight and thus the surgical risk for the second intervention (the actual biliopancreatic diversion).

A malabsorptive procedure such as biliopancreatic diversion is particularly recommended for people who are unable to switch to unfavorable eating habits. While these people lose weight poorly through other procedures (such as gastric or gastric banding), bilocalancreatic diversion may lead to weight loss due to malabsorption, even with persistently unfavorable eating habits.

For whom is biliopancreatic diversion not suitable?

There are several physical and mental illnesses in which an obesity operation such as biliopancreatic diversion is not indicated (contraindicated). In particular, previous operations and malformations of the stomach or intestine can be important contraindications for biliopancreatic diversion. Mental comorbidities such as addictions or untreated eating disorders (such as binge eating or bulimia) are also excluded from the procedure. Whether one is suitable for biliopancreatic diversion or not, one learns in advance in conversation with the surgeon.

Efficacy of biliopancreatic diversion

Biliopancreatic diversion is the surgical procedure that usually achieves the greatest weight loss. Studies show an excess weight loss (EWL) after one year of 52 percent for BPD alone and 72 percent for BPD-DS. In addition to the purely cosmetic and mentally relieving effect, the weight loss after the procedure also has a positive effect on the metabolism of the patients. Thus, the intervention in many cases, an existing diabetes mellitus greatly improved or even completely cured. Also, the blood glucose levels are often normalized a short time after surgery, although the patient has not yet significantly decreased at this time. The reasons for this are not yet completely clear. Some researchers suspect that the altered gastrointestinal passage, various hormonal changes are set in motion, which have a beneficial effect on the energy metabolism.

Benefits of biliopancreatic diversion over other procedures

Since the effect of biliopancreatic diversion is based on two different principles (restriction and malabsorption, see above), the method is particularly effective and is particularly effective in people whose obesity is caused by the excessive intake of high-calorie foods or beverages. For these people, sometimes referred to as “sweet-eaters,” a stomach-shrinking procedure such as the gastric balloon, gastric band, or gastric stomach would not be sufficiently effective.

Disadvantages and side effects of the procedure

A biliopancreatic division is a surgically demanding procedure. Compared to the tube stomach operation significantly more cuts and sutures are necessary. The intervention in the digestive system is very pronounced and after successful weight loss is not completely reversible. Therefore, you should familiarize yourself with the possible side effects before the procedure. How strong these are in the individual case, is individually different:

Deficiency symptoms: The most common side effects of biliopancreatic diversion include a lack of vitamin D and vitamin B12: Vitamin B12 is absorbed in the last section of the small intestine (terminal ileum). In addition, a certain auxiliary protein must be present for the intake, the so-called intrinsic factor (“intrinsic factor”). The intrinsic factor is formed in the stomach. Since biliopancreatic diversion removes a large part of the stomach, the formation of the intrinsic factor is reduced and thus the vitamin B12 uptake is severely reduced.

Therefore, for a lifetime, vitamin B12 supplements in the muscle or via the vein into the blood are necessary. It is also vitamin B-12 preparations that are absorbed directly through the oral mucosa (sublingual application), but their effectiveness is questionable. Why it may come after a Biliopankreatischen diversion to a vitamin D deficiency, is not yet safe clarified.

Patients with biliopancreatic diversion should be careful to consistently administer vitamins B12 and D – otherwise serious complications such as anemia (anemia in vitamin B-12 deficiency) and osteoporosis (due to vitamin D deficiency) may occur.

Dumping syndrome: A dumping syndrome is the coming together of several symptoms, which can result from the fall-like evacuation of only slightly predigested food from the rest of the stomach into the small intestine. Since the Magenpförtner is missing, the concentrated food pulp passes directly into the small intestine. There, following physical laws (osmosis), he draws water from the surrounding tissue and blood vessels into the intestine.

As a result, the volume of fluid in the bloodstream is reduced, which can lead to a pronounced fall in blood pressure until it collapses. Some people report related symptoms such as dizziness, nausea, sweating, or severe palpitations (early dumping). In addition, the high water content of the chyme can cause severe diarrhea.

A dumping syndrome occurs especially after the supply of osmotically very active (hyperosmolar) food, for example, in sugary drinks or fatty foods. The dumping syndrome is prevented by the PBD-DS (see above). In this variant of biliopancreatic diversion, the gastric pusher is obtained.

Loss of muscle mass: Due to the greatly reduced supply of nutrients creates a relative lack of carbohydrates, which seeks to compensate for the body by new formation of sugar from amino acids. Amino acids are the building blocks of the proteins (proteins), which in turn are an important building material of the musculature. The body thus degrades above all less used musculature in order to secure the energy balance. Patients following biliopancreatic diversion should therefore counteract muscle breakdown through increased physical activity. Particularly suitable are joint-friendly sports such as cycling, moderate strength training, swimming or aqua jogging.

Biliopancreatic diversion: risks and complications

Biliopancreatic diversion involves several general and specific surgical risks. This includes:

• general anesthesia risks
• Thrombosis of deep leg veins with the risk of pulmonary embolism
• Infections in the area of ​​outer and sutures
• Leakage of the sutures on the stomach pouch / pericardium or small intestine (suture insufficiency) with the risk of peritonitis (Peritonitis)

In studies, mortality after biliopancreatic diversion was between 0.5 and 7.6 percent. However, these are pure statistical values. The individual surgical risk depends largely on the physical condition at the time of the operation.

Diet after surgery

After biliopancreatic diversion, a fundamental change in diet is necessary to avoid digestive problems. Apart from that, the less fat and calorie you eat after surgery, the more pronounced the weight loss. The following nutritional rules must be adhered to for life after the biliopancreatic diversion:

• Meals may only include small portions (reduced stomach size)
• every single bite must be chewed very well, since the pre-digestion by the stomach is eliminated
• sugary foods or drinks and very long-fibered meat should be avoided
• Dietary supplements (especially vitamin D, vitamin B12) must be taken for life

Even medicines are partially absorbed differently or in smaller quantities. The Biliopancreatic diversion therefore, if necessary, requires an adjustment of the time of administration and dose of the drugs.