Over a period of 25 years the weight development of 100 patients who had undergone stomach stapling was examined. “Naturally, these are no people who just want to get rid of some additional pounds; there was a medical indication.” explained Dr. Rafael Weißbach who statistically analysed the data.

The patients had an average weight of 132 kilograms before the operation. In the period directly after the surgery the weight drastically went down. In the first 3 years following the operation the patients lost on average 40 percent of their overweight.

As there are no long-term studies on this topic up to now, it was not possible to give a prognosis regarding the long-term weight development at the time of the surgeries.

There were grounds for the assumption that the stomach was going to expand and the patients were going to return to their eating habits and regain their former weight.

But as the data analysis show, this seems not to be the case. Although Weißbach found all patients to have gained weight in the following years the weight levelled off relatively stable. “We can really speak about a long-term weight reduction”, is the conclusion of the statistician.

To gather the data the patients were weighed seven times over a period of 25 years. Based on this weight data the Dortmund statisticians determined the “Body Mass Index”, meaning the absolute weight and the relative weight loss - two numbers confirming the long-term weight reduction based on at least 20 different test procedures. According to Weißbach this complex procedure is necessary: “In case of such a small control group which is absolutely common practice for medical examinations, many different tests are necessary to eliminate mistakes”.

Depending on the method of stomach stapling chosen, there were slight differences among the 100 patients. The complete transection of the stomach in its upper part, meaning a drastic reduction of the functional stomach reservoir with a direct connection with the small intestine, proved to be the most effective method. Whereas a big abdominal incision was necessary to perform this operation more than 25 years ago, today “minimally invasive” “keyhole surgery” is more safe and promises a real long-term weight reduction. According to the statisticians there were no differences between men and women - they all lost a lot of weight after the operation.