Obesity – if only the scalpel could help

Derived from the Greek word for weight, “baros”, this discipline deals with the surgical treatment of obesity. Its origins started in the USA, where the first surgical procedures for treatment of obesity were carried out as early as the 1950s. Since then, the number of interventions has steadily increased and today there are more than a hundred thousand procedures performed worldwide each year.

There is currently no gold standard for bariatric interventions. There are both advantages and disadvantages for the surgical procedures available, which must be weighed up. Fundamentally, all methods are based on a reduction of stomach volume and the associated restriction of food intake.

The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) collects the data of bariatric interventions from more than 50 countries.

Their current report from 2018 encompasses approximately 190,000 interventions performed between 2014 and 2018. According to the report, the majority of the interventions were for the so-called sleeve gastrectomy, with around 45%, followed by the gastric bypass at around 38%. The once-popular stomach band now plays only a minor role, at 5% of the operations. There are also other procedures, however these represent only a small proportion of the total.

Sleeve Gastrectomy

With a sleeve gastrectomy, around 80% of the stomach is removed. The stomach then resembles a sleeve or a banana, with a significantly reduced capacity, which means only a reduced amount of food can be eaten at each meal. At the same time, the feeling of being full arises much faster. Sleeve gastrectomy is a very effective procedure which in most cases can lead to a rapid and permanent weight reduction of over 50%. The surgery is minimally invasive, which can lower the incidence of complications and reduce hospital stays to just a few days.

As an operative procedure, however, there are always inherent risks with surgery and narcosis that can not be reversed. Vitamin deficiencies can develop through the removal of large parts of the stomach, which make a lifelong substitution necessary.

Gastric Bypass

For the so-called Roux-Y gastric bypass, the operation is done in two steps.

First, the upper part of the stomach is separated creating a “pouch” with a capacity of about 30ml. Then the larger remainder of the stomach is closed with sutures.

The small intestine is then severed, and the descending portion is adapted to the new reduced stomach. As a result, there is a segment which is now switched off consisting of the remainder of the stomach, the duodenum and small intestine. Since the ducts of the gallbladder and the pancreas flow into the duodenum and their secretions are essential for digestion, this switched off segment has to be re-attached to the small intestine. To do this, the formerly turned off intestinal section is stitched laterally to a lower-lying intestine section, which gives rise to the Y-shape that is formed.

After the operation, ingested food first reaches the significantly smaller stomach and from there directly to the small intestine. The bile and digestive liquids from the pancreas only come into contact with the food at the point of the newly created small intestine connection. Consequently, the main part of the stomach, the duodenum and parts of the small intestine no longer come into contact with ingested food, therefore eliminating these segments from active digestion.

Through various mechanisms, this method promotes fast and sustained weight loss. Initially, the reduced stomach prevents the consumption of large quantities of food. In addition to this, the operative change to the gastrointestinal tract negatively affects the digestion and the absorption of nutrients, which means the nutrients taken in can only be utilised to a lesser degree.

Although the procedure proves to be extremely effective, the operation risks of this complex intervention must not be ignored. Furthermore, the altered architecture of the gastrointestinal tract can give rise to digestive problems and a lack of nutrition.

Gastric Band

Compared to the removal of stomach sections, a gastric band represents a relatively gentler method. To do this, a plastic band is placed around the stomach with minimum invasion and a small part of the stomach tied off. Additionally, the band is connected to a small fluid reservoir or port which is implanted under the skin. By injecting saline into the system, the gastric band can be additionally inflated, further shrinking the opening between the constricted portion and the residual stomach. This process can be repeated and can further narrow the connection to the remaining stomach, as well as decrease the emptying speed of the stomach.

As in the methods already presented, patients can only eat small meals and have a faster onset of satiety.

Due to the limited scope of the surgery, the risks associated with this procedure are significantly lower than those for major gastrointestinal operations. Digestive problems and absorption disorders rarely occur as the stomach and intestinal sections remain unaffected. Amongst the clear advantages is also the possibility of further adjustments after the operation.

On the other hand, this method requires a foreign body to remain in the abdominal cavity, which may be linked to long-term complications. Additionally, in comparison to the other methods, this gives the lowest and slowest reduction in weight. There is also a danger that the band will loosen or slip completely so that frequent follow-up operations become necessary.

Regardless of the chosen procedure, bariatric interventions can represent the last treatment choice for some obese patients. Their advantages have been proven many times over. Along with the loss of body weight and a gain in quality of life, studies show clear positive effects on health.

Through the loss of weight, patients benefit from a demonstrable reduction of the risk of cardio-vascular diseases and type 2 diabetes. Existing arterial hypertension or symptoms of diabetes can either be reduced in severity or even completely regressed.

Considering the spreading global obesity epidemic, bariatric surgery will continue to be an important treatment option. However, due to the associated risks, the decision for or against surgery remains a decision for each individual case.  

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