Several retrospective studies have shown same efficiency in regard to weight loss, with a lower rate of complications for the laparoscopic mini gastric bypass (LMGB) compared to Roux-en-Y gastric bypass (LRYGB). The aim of this double-blinded randomized controlled trial is to compare the two procedures in respect of excess weight loss, complications, operation time, length of stay and the metabolic impact on the hormonal brain-gut-axis.

Bariatric surgery, the only effective treatment for morbid obesity, has shown effective long term weight loss and good control of obesity related comorbidities in randomized controlled trials.

Obesity related diseases, such as hypertension, type 2 diabetes, dyslipidemia, osteoarthritis and various tumours, have a significant socio-economic impact, since the cost of the obesity epidemic is 5.7 billion Swiss francs yearly.

According to the current Swiss National Guidelines defined by the Swiss Group for Morbid Obesity surgical therapy is indicated in cases of BMI 35 kg/m2 or higher, showing better weight reduction and control of comorbidties than conservative therapy alone. Obesity reduces quality of life and life expectancy dramatically. Furthermore it has a significant impact on our economy. Bariatric surgery is likely to improve all of these negative impacts on society.

The most commonly performed procedures at present are laparoscopic adjustable gastric banding, laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG).

LRYGB is considered the golden standard in bariatric surgery, although little evidence is available to justify this standpoint. In fact, the choice of the surgical procedure depends more on patient factors such as present comorbidities and operative risk. Therefore, surgeons consult after a work up within a multidisciplinary team of caretakers such as nutritionists, endocrinologists and psychiatrists and chose a patient tailored approach. Recently, the laparoscopic mini gastric bypass (LMGB) has gained worldwide popularity in addition to the standard available procedures for the treatment of morbid obesity. Therefore, it has been added by the Swiss Group for Morbid Obesity as a surgical option, which has to be evaluated in clinical trials.

Robert Rutledge, the pioneer of the LMGB, published in 2001 results of 1274 patients, who received surgical treatment with LMGB. After two years the patients showed an excess weight loss (EWL) of 77%. The rate of anastomotic leakage in the gastroenterostomy amounted 1.6%. The rate of mortality was 0.08%. Subsequently, Rutledge published in 2005 the results of 2410 patients with a follow up of 38.7 months. These cohort reached/achieved an EWL of 80% after a year and even after 5 years 5% of all these patients showed a weight rebound of maximum 10 kg. In fact, those results seemed superior to outcomes of the other standard bariatric procedures.

The rate of anastomotic leakage was 1.08%, mortality 0.08%. Long-term complications were ulcer disease (4%) and iron deficiency (5%). Both complications are also known in LRYGB with similar rates.

The first and only randomized controlled trial comparing the LRYGB to LMGB was carried out by Lee in 2005. With a group of 40 patients the effectiveness of LMGB was compared to the LRYGB. The authors found an EWL of 64.9% after one and 64.4% after two years, respectively, in patients having a LMGB accompanied by less complications and a shorter hospitalization time than in LRYGB. Patients with LRYGB had an EWL of 58.7% and 60%, respectively.

These results showed similar benefits of the LMGB compared to LRYGB. This is in accordance with the already mentioned observational studies.

Inclusion Criteria:

• BMI > 35
• age > 18

Exclusion Criteria:

• malignancy
• lack of compliance
• BMI > 50