Omega Loop Gastric Bypass With And Without Anti-Reflux Sutures

  • End date
    Jul 1, 2021
  • participants needed
  • sponsor
    Medical University of Vienna
Updated on 26 January 2021


This proposed trial is designed to answer the following questions: First, is biliary reflux to the distal esophagus present before OLGB and does it increase after the procedure? Second, does performing an OLGB with or without anti-reflux sutures make a difference in (biliary) reflux exposures of the distal esophagus? To answer these questions the investigators plan to perform a randomized, controlled trial involving two groups. Group A will undergo an OLGB without anti-reflux sutures and consists of 50 patients. Group B will receive an OLGB with anti-reflux sutures and also consists of 50 patients.

Gastroscopic evaluation for inflammation and reflux will be performed before and one year after the operation utilizing multilevel intraluminal impedance pH-monitoring (MII-pH) and intragastric Bilitec 2000. Furthermore, the study will be blinded to the patient. Long-term weight loss, the resolution of comorbidities and the incidence of surgical complications will serve as secondary endpoints. Follow-ups will be performed at 3, 6, and 12 months postoperatively to assess all primary and secondary goals.


Obesity, and especially its comorbidities, has unarguably become the number one threat to human health in the modern world. Western lifestyle leads to an increased prevalence and thus to a higher mortality (i.e. due to cardiovascular diseases).

The positive effects of gastric bypass surgery on excess weight loss and comorbidity resolution are well-known. In contrast to the standard laparoscopic Roux-en-Y Gastric Bypass (RYGB), a newer method, the laparoscopic Omega Loop Gastric Bypass (OLGB), has emerged over the past years. It is believed to be the simpler method involving only one anastomosis (instead of two) and therefore potentially reducing morbidity and mortality whilst maintaining comparable excess weight loss. However, since this new type of gastric bypass is similar to the former Billroth II resection (BII), the carcinoma risk is a concern. The OLGB is different from the BII resection in many ways. For instance, it involves creating an approximately 10 cm long narrow gastric pouch which could prevent the suspected underlying pathogenetic mechanism: biliary reflux to the gastric tube and subsequently to the esophagus. Biliary reflux is suspected to stimulate squamous esophageal cells and Barrett's epithelial cells to produce inflammatory mediators and therefore cause oxidative stress, DNA damage and apoptosis which might lead to adenocarcinoma.

Worldwide, there are currently two different ways to perform an OLGB: with or without anti-reflux sutures, which involve sewing the biliopancreatic limb to the staple line of the pouch using V-Loc (non-absorbable) moving upwards as far as easily possible without creating any tension.

This proposed trial is designed to answer the following questions: First, is biliary reflux to the distal esophagus present before OLGB and does it increase after the procedure? Second, does performing an OLGB with or without anti-reflux sutures make a difference in (biliary) reflux exposures of the distal esophagus?

Condition Bile Reflux
Treatment Omega Loop Gastric Bypass, Bilitec 2000™, V-Loc
Clinical Study IdentifierNCT03097887
SponsorMedical University of Vienna
Last Modified on26 January 2021


Yes No Not Sure

Inclusion Criteria

Is your age between 20 yrs and 70 yrs?
Gender: Male or Female
Do you have Bile Reflux?
Do you have any of these conditions: Do you have Bile Reflux??
Age between 20 and 70 years
Body Mass Index 35.0 kg/m2
Exclusion of psychological, endocrinological and anesthesiological contraindications
Willingness to be assigned to either of the two groups
Follow-up anticipation
Willingness to attend all follow-up visits
Written informed consent

Exclusion Criteria

recent or ongoing cardiovascular event within the last 6 months (myocardial infarction, acute coronary syndrome, angioplasty or coronary bypass operation, insult)
pulmonary embolism or thrombophlebitis within the last 6 months, other bariatric procedures, e.g. gastric banding, Sleeve Gastrectomy, etc., cancer of various origins (exceptions: basal cell carcinoma or carcinoma in situ, disease-free over the last 5 years)
significant anemia or coagulopathy
serum creatinin 1.5 mg/dl
serum bilirubin or phosphatase elevated or ALT above 3 times the upper limit, stomach, biliopancreatic operations, splenectomy or colon resections, gastric or duodenal ulcer within the last 6 months
intraabdominal sepsis (except uncomplicated appendicitis or diverticulitis over 6 months prior to the study)
organ transplantations
anamnestic HIV infection, active TBC, active malaria, chronic Hepatitis B or C, liver cirrhosis
alcohol or drug addiction (except caffeine, nicotine) in history
acute psychiatric disease interfering with the proposed trial
other chronic disease which might interfere with the participation
Also, patients who are pregnant or plan a pregnancy within the following two
years as well as patients who have been included in another study, will be
Note: Exclusion can be performed by a study coordinator at any time
Hiatal hernia is not considered an exclusion criterion in this study
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