The aim of this study is to compare the relative clinical outcomes between two variants of gastric bypass [Roux-en-Y Gastric Bypass (RYGB) or Omega-Loop Gastric Bypass (OLGB)] in metabolic surgery candidates with Body Mass Index (BMI) between 35 and 50. The study will examine the short and medium term effects of each intervention on weight, obesity comorbidities, quality of life and gastroscopy findings.

Introduction:

Obesity is a risk factor for Diabetes, Ischemic heart disease, Stroke, and Hypertensive heart disease, which are the 6th, 1st, 2nd, and 10th leading causes of death according to the WHO. Bariatric or Metabolic Surgery is an Efficient and reasonably Safe method for the Treatment of Severe Obesity, Type 2 Diabetes (T2DM) and Metabolic Syndrome (MS).

Existing knowledge:

Metabolic procedures, e.g. Gastric bypass, are more effective in the treatment of T2DM than predominantly "restrictive" procedures, e.g. Gastric Banding. RYGB is one of the most prevalent procedures in the world and Europe. In the USA, RYGB is considered a "golden standard" in bariatric surgery. In the recent decade, a simpler variant of Gastric bypass, i.e. OLGB, has been proposed. Proponents of OLGB argue it has less complications and seems to have higher and more durable effect on weight reduction and T2DM improvement. Opponents of OLGB are concerned that chronic exposure of gastric or esophageal mucosa to bile, as seen in animal experiments and in patients operated for gastric cancer or peptic ulcer disease, pose a severe health risk. So far, this concerns has not been confirmed in OLGB patients. Only one Randomized Controlled Trial (RCT) of these two interventions was performed, concluding OLGB to be simpler and safer with a similar Efficacy 2 years after the surgery.

Need for a trial:

A growing evidence supports the efficacy and safety of bariatric and metabolic surgery for the treatment of severe obesity and T2DM. Therefore, bariatric surgery is being more frequently performed. However, there is little evidence from randomized trials comparing different bariatric procedures - most comes from retrospective cohorts, which might suffer from bias. As a result, the choice of a bariatric procedure for a particular patient is based largely on the preference and experience of the particular surgeon, rather than evidence of best benefit for a particular patient. Although the efficacy and safety of RYGB is well established, newer variants or other less frequently employed bariatric procedures might offer more preferable Efficacy or Safety profile for some patients. Some evidence suggests OLGB might a promising procedure, which is "simpler and safer with similar efficacy" in comparison to RYGB, a technically more demanding procedure. This study contributes with rigorous evidence to further define the relative strengths and weaknesses of OLGB as compared to the "gold standard" RYGB.

Objectives:

The purpose of this study is to objectively compare the efficacy of RYGB and OLGB on weight, T2DM and other obesity-related comorbidities. Furthermore, this study aims to provide more insight into the safety of OLGB and RYGB by measuring the incidence of complications and abnormal findings on Gastroscopy.

Inclusion Criteria:

• Severe Obesity: BMI ≥ 40 and ≤ 50 or (BMI ≥ 35 and < 40 and type 2 diabetes or metabolic syndrome)
• Inadequate results of Attempts to loose weight by Conservative means
• Ability to understand the nature of the procedure and willing to follow postoperative routine lifestyle and checkups
• no contraindication for bariatric surgery on psychological assessment
• no contraindication for general anesthesia
• consent for both variants of gastric bypass surgery
• consent to participate in a study with randomized design

Exclusion Criteria:

• prior bariatric surgery of any kind
• gravidity or recent (<1 year) labour
• drug or alcohol abuse
• symptomatic Gastro Esophageal Reflux Disease (GERD)
• hiatal hernia, > 3cm
• esophagitis, ≥ 2. grade
• active smoker
• chronic renal disease, stage ≥ 3
• patient immobility
• surgery not covered by universal insurance in Czech rep. (i.e. international patients)