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NCT Number: NCT06057597

Omega Gastric Bypass (150cm) Compared to the Roux-en-Y Gastric Bypass (YOMEGA-2 Multicentric Trial)

Obesity with its consequences such as type 2 diabetes, high blood pressure, dyslipidemia, fatty liver disease, sleep apnea and cancers, remains a major healthcare problem worldwide. Bariatric surgery, combined with nutritional education and close monitoring, has been shown to be the most effective treatment for patients with morbid obesity resulting in significant and lasting weight loss and improvements in co-morbidities . With nearly 50000 procedures per year France ranks third in the world in terms of care for patients suffering from morbid (BMI ≥ 40 kg/m²) and severe (BMI 35-40 kg/m²) obesity.

In parallel with the significant increase in the number of patients operated on for obesity in the world, over the past two decades, significant development has been observed in the field of bariatric surgery with a decrease or even disappearance of some procedures and the appearance of others.

Performed for more than 40 years, the Roux-en-Y Gastric Bypass (RYGB) is a restrictive and malabsorptive procedure and currently is considered as gold standard procedure for the treatment of morbid obesity and its comorbidities. However, despite the good effectiveness (with an average Excess Weight Loss % (EWL%) of approximatively 70% at 2 years), RYGB is technically demanding procedure with learning curve requiring more than 100 cases and an overall complication rate ranging from 10% to 20% Introduced in 2001, one anastomosis gastric bypass (OAGB) is a modified gastric bypass that consists of a single gastrojejunal anastomosis between a long gastric pouch and a jejunal (biliopancreatic) omega loop. In Sept. 2019, taking into account the results from YOMEGA trial, the French High Authority for Health (Haute Autorité de Santé (HAS)) recommended to ban OAGB with 200 cm or longer BPL and urged to assess the efficacy and safety of OAGB with 150 cm BPL in a randomized controlled trial. Indeed, YOMEGA-2 trial is logical continuity of the YOMEGA trial.

The aim of this study is to assess weight loss efficiency and the nutritional safety of the OAGB-150 in comparison to a standard (RYGB).

The hypothesis of this study is that the OAGB with a 150 cm BPL could have the same efficacy on weight loss and nutritional complication rate in comparison to the RYGB at 2 years.

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Key information

Conditions

Obesity Body Weight Morbid Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hôpital Bichat Claude-Bernard

Paris, France

Location status: Recruiting

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient aged from 18 to 65 years old
  • Type III obesity (BMI ≥ 40 kg/m²), or Type II obesity BMI 35-40 kg/m2 associated with at least one co-morbidity which will be improved by surgery (high blood pressure, type 2 diabetes mellitus, obstructive sleep apnea, dyslipidemia, arthrosis)
  • Patient who had benefited from an Upper GI Endoscopy with biopsies to look for Helicobacter pylori within 12 months before surgery
  • Patient who has benefited from a multidisciplinary evaluation at least 6 months, with a favorable opinion for a gastric bypass
  • Patient who understood and accepted the need for a long-term follow-up
  • Patient who agreed to be included in the study and who signed the informed consent form
  • Patient affiliated to a social security scheme
  • For child-bearing aged women, efficient contraception

Exclusion criteria

  • History of previous bariatric surgery
  • History of chronic inflammatory bowel disease
  • Presence of chronic diarrhea
  • Presence of a severe and evolutive life threatening pathology
  • Presence of dysplastic modifications of the gastric mucosa, chronic atrophic gastritis or history of gastric cancer
  • Presence of an unhealed gastro-duodenal ulcer
  • Presence of Helicobacter pylori resistant to medical treatment
  • Presence of esophagitis
  • Pregnancy or desire to be pregnant during the study
  • Mentally unbalanced patients, under supervision or guardianship
  • Patients who don't understand French and not able to give consent
  • Patient included and followed in another interventional trial
  • Unable to consent, under tutelage or curatorship, or judiciary safeguard
  • Presence of type 1 diabetes

Treatment and study plan

Laparoscopic OAGB

Procedure

It is a gastric bypass surgery with a unique gastro-jejunal anastomosis, a long (11-14cm) and narrow (3-4cm) gastric pouch will be created by applying one horizontal 45-mm stapler at the angle of lesser curvature, just above the left branch of the crow's foot, and then four to five vertical 60-mm staple cartridges will be placed upwards to the angle of His, and calibrated along a 32-Fr bougie. Sectioning of the greater omentum into a bivalve will be performed. The jejunum will be measured using pre-measured strip and amounted antecolically at 150 cm from the ligament of Treitz. An end-to-side anastomosis will be performed with the gastric pouch, using a 45-mm linear stapler and an anterior running suture to close gastro-enterotomy.

Other names: One Anastomosis Gastric Bypass / Mini Gastric Bypass

Laparoscopic RYGB

Procedure

A small gastric pouch (30cc) will be created using a linear stapler. The alimentary limb will be moved up into an antecolic position after an epiploic transection so as to perform the gastro-jujunal anastomosis. The gastro-jejunostomy will be performed manually or using a linear or circular stapler. An alimentary limb of 150 cm and a biliary limb of 50cm will be measured (using premeasured strip) in order to perform the latero-lateral jejuno-jejunal anastomosis using a linear stapler. All mesenteric defects (Petersen's space and mesenteric defect) will be closed with a non-absorbable running suture

Other names: Roux-en-Y Gastric Bypass

Primary outcomes

  1. To demonstrate that OAGB with 150 cm biliopancreatic limb is not inferior to RYGB on weight loss (efficacy).

    Time frame: 2 years after the surgery

    For each patient co-primary endpoints will be assessed at 2 years after surgery composed by:

    Efficacy: Weight loss according to Excess Weight Loss % (EWL%) calculated using the following formula: ((weight 2 years after surgery - initial weight) / (initial weight - ideal weight)) x 100. Ideal weight defined as the weight corresponding to a BMI = 25 kg/m².

    The assessment of the primary co-endpoint will be standardized between the sites.

  2. To demonstrate that OAGB with 150 cm biliopancreatic limb is not inferior to RYGB on nutritional complication rate (safety)

    Time frame: 2 years after the surgery

    For each patient co-primary endpoints will be assessed at 2 years after surgery composed by:

    Safety: Nutritional complications defined by at least one vitamin deficiency (vit. B1 < 66nmol/l or B12 < 145pmol/l), malnutrition (albumin < 30g/l), anemia (hemoglobin < 10g/dl) or a combination of these.

    The assessment of the primary co-endpoint will be standardized between the sites.

Secondary outcomes

  1. Measurement of albumin

    Time frame: Before and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of albumin will explore the nutritional status of patients. Results will be expressed in g/l

  2. Measurement of pre-albumin

    Time frame: Before and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of pre-albumin will explore the nutritional status of patients. Results will be expressed in g/l

  3. Measurement of hemoglobin

    Time frame: Before and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of hemoglobin will explore the nutritional status of patients. Results will be expressed in g/l

  4. Measurement of calcium

    Time frame: Before and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of calcium will explore the nutritional status of patients. Results will be expressed in mmol/l

  5. Measurement of ferritin

    Time frame: Before and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of ferritin will explore the nutritional status of patients. Results will be expressed in μg/l

  6. Measurement of iron

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of iron will explore the nutritional status of patients. Results will be expressed in mmol/l

  7. Measurement of % of transferrin saturation

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of % of transferrin saturation will explore the nutritional status of patients. Results will be expressed in %

  8. Measurement of zinc

    Time frame: Before surgery and 6, 12 months and 24 months after surgery

    Measurement of zinc will explore the nutritional status of patients. Results will be expressed in mmol/L

  9. Measurement of vitamin A

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin A will explore the nutritional status of patients. Results will be expressed in mmol/l

  10. Measurement of vitamin B1

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin B1 will explore the nutritional status of patients. Results will be expressed in nmol/l

  11. Measurement of vitamin B9

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin B9 will explore the nutritional status of patients. Results will be expressed in nmol/l

  12. Measurement of vitamin B12

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin B12 will explore the nutritional status of patients. Results will be expressed in pmol/l

  13. Measurement of vitamin E

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin E will explore the nutritional status of patients. Results will be expressed in mmol/l

  14. Measurement of vitamin D

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of vitamin D will explore the nutritional status of patients. Results will be expressed in nmol/l

  15. Measurement of prothrombin rate

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Measurement of prothrombin rate will explore the nutritional status of patients. Results will be expressed in %

  16. Measurement of the 24-hour steatorrhea rate

    Time frame: 6 month after surgery

    Measurement of the average number of stool will explore the nutritional status of patients. Results will be expressed in number of stool/day

  17. Measurement of HbA1c

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of HbA1c will explore the Metabolic efficiency of surgery. Results will be expressed in %

  18. Measurement of fasting glycemia

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of fasting glycemia will explore the Metabolic efficiency of surgery. Results will be expressed in mmol/l

  19. Measurement of HDL

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of HDL will explore the Metabolic efficiency of surgery. Results will be expressed in mmol/l

  20. Measurement of LDL

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of LDL will explore the Metabolic efficiency of surgery. Results will be expressed in mmol/l

  21. Measurement of cholesterol

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of cholesterol will explore the Metabolic efficiency of surgery. Results will be expressed in mmol/l

  22. Measurement of triglycerides

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Measurement of triglycerides will explore the Metabolic of surgery. Results will be expressed in mmol/l

  23. Evaluation of antidiabetic drugs

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Assessment of number of antidiabetic medications will explore the Metabolic efficiency of surgery. This outcome will be expressed in terms of increase, decrease, discontinuation or restart of treatment.

  24. Evaluation of antilipidemic drugs

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Assessment of the number of antilipidemic medications will explore the Metabolic efficiency of surgery. This outcome will be expressed in terms of increase, decrease, discontinuation or restart of treatment

  25. Evaluation of antihypertensive drugs

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Assessment of the number of antihypertensive medications will explore the Metabolic efficiency of surgery. This outcome will be expressed in terms of increase, decrease, discontinuation or restart of treatment.

  26. Evaluation of the use of Continuous Positive Airway Pressure for Obstructive Sleep Apnea

    Time frame: Before surgery and 6, 12 and 24 months after surgery

    Evolution of the use of Continuous Positive Airway Pressure for Obstructive Sleep Apnea will explore the Metabolic efficiency of surgery. This outcome will be expressed in terms of the use or discontinuation of the use of Continuous Positive Airway Pressure machine

  27. Hospitalization length

    Time frame: The last day of hospitalization

    The Length of stay (in days) is based on the number of days of hospitalization from surgery (day of surgery = D0) until the end of hospitalization.

  28. Number of patients readmitted

    Time frame: 30 days after surgery

    Number of patients readmitted within 30 days after surgery.

  29. Occurrence of kidney stone

    Time frame: Within 2 years after surgery

    For each visit after the surgery, the presence or not of kidney stones will be documented and if applicable the treatment will be noted

  30. Overall complications rate

    Time frame: Within 24 months after surgery

    Rate of medical and surgical (> or = grade III) complications within 24 months after surgery using the Dindo-Clavien classification, described as :

    Grade I = Any deviation from the normal postoperative course. Grade II = Requiring pharmacological treatment with drugs other than such allowed for grade I complications.

    Grade III = Requiring surgical, endoscopic or radiological intervention, not under (Grade IIIa) or under general anesthesia (Grade IIIb) Grade IV = Life-threatening complication with single organ (Grade IVa) or Multiorgan dysfunction (Grade IVb) Grade V = Death of a patient.

  31. Type of early complications

    Time frame: Within 30 days after surgery

    Type (medical or surgical) of early complications (within 30 days) for each procedure.

  32. Severity of early complications

    Time frame: Within 30 days after surgery

    Severity of early complications (within 30 days) for each procedure according to the Dindo-Clavien classification

  33. Type of late complications

    Time frame: Within 2 years after surgery

    Type (medical or surgical) of late complications (after 30 days) for each procedure.

  34. Severity of late complications

    Time frame: Within 2 years after surgery

    Severity of late complications (after 30 days) for each procedure according to the Dindo-Clavien classification

  35. Gastroesophageal reflux assessment

    Time frame: Before surgery and 1, 3, 6, 12, 18 and 24 months after surgery

    Evolution of gastroesophageal reflux will be assessed at each study visit, before and after surgery. This outcome will be expressed in terms of improvement, aggravation or onset.

  36. Absolute weight loss assessment

    Time frame: 1, 3, 6, 12, 18 and 24 months after surgery

    Weight loss at 1, 3, 6, 12, 18 and 24 months after surgery, according to absolute weight loss (aWL) in kg.

  37. Excess Weight Loss percentage assessment

    Time frame: 1, 3, 6, 12, 18 and 24 months after surgery

    Weight loss at 1, 3, 6, 12, 18 and 24 months after surgery, according to Excess Weight Loss percentage (EWL%), calculated using the following formula:

    ((weight at visit X - initial weight) / (initial weight - ideal weight)) X 100

  38. Excess BMI Loss percentage assessment

    Time frame: 1, 3, 6, 12, 18 and 24 months after surgery

    Weight loss at 1, 3, 6, 12, 18 and 24 months after surgery, according Excess BMI Loss percentage (EBL%), according to the formula :

    ((BMI at visit X - initial BMI) / (initial BMI - ideal BMI)) X 100 with Ideal BMI = 25 kg/m²

  39. Quality of life assessed with GIQLI questionnaire

    Time frame: Before surgery and at 6, 12 and 24 months after surgery

    This questionnaire consists of 36 items exploring 5 dimensions or subscales: symptoms, physical condition, emotions, social integration and the effect of any medical treatment. For each item, 5 responses will be proposed to the patients and for each answer, a score ranging from 0 to 4 (highest score = 144) will be assigned. A high score defines a more favorable health state

  40. Quality of life assessed with SF36 questionnaire

    Time frame: Before surgery and at 6, 12 and 24 months after surgery

    This questionnaire taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/tiredness, and general health perceptions. It also includes a single item that provides an indication of a perceived change in health

  41. Quality of life assessed with Sigstad questionnaire

    Time frame: Before surgery and at 1, 3, 6, 12, 18 and 24 months after surgery

    The Sigstad questionnaire allows the identification and diagnosis of postoperative dumping syndrome and early hypoglycaemia: a score >7 suggests a dumping syndrome

  42. Body composition

    Time frame: Before and 24 months after surgery.

    Body composition level on a subsample of the total population:

    By impedancemetry :

    • Muscle mass index in kg/m2
    • Non-fat mass index in kg/m2
    • Fat mass index in kg/m2

  43. Sarcopenia level

    Time frame: Before and 24 months after surgery.

    Sarcopenia level on a subsample of the total population will be assessed by Handgrip Strength

Study contacts

Contact information is provided by the study sponsor or research team.

Tigran POGHOSYAN, MD-PhD

CONTACT

[email protected]

33 1 40 25 82 39

Sponsors and collaborators

Lead sponsor

Assistance Publique - Hôpitaux de Paris

Other

Registry information

Official study title

Randomized Controlled Non-inferiority Trial Evaluating the Safety and Efficacy of the Omega Gastric Bypass With 150 cm Biliopancreatic Loop Length Compared to the Roux-en-Y Gastric Bypass

Acronym: YOMEGA-2

Important dates

Study start
2023
Primary completion
2028
Study completion
2028
First posted
Sep 28, 2023
Registry last updated
Feb 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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