Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT04433338

The PREBA Study: Effect of Preoperative Weight Loss With a 14-day Low-calorie Diet on Surgical Procedure and Outcomes in Patients Undergoing RYGB Surgery

Bariatric guidelines recommend preoperative weight loss of 5% to reduce the risk of surgical complications. However, results in the literature on the improvement of surgical procedure and outcomes are still conflicting.

This study aims to evaluate the effect of preoperative weight loss by means of a 14-day low-calorie diet in bariatric patients on operative time, the ease of the Roux-en-Y gastric bypass (RYGB) procedure and long-term weight loss in a real-life experimental setting.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

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

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Rijnstate Hospital

Arnhem, Gelderland, 6811AD, Netherlands

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Undergoing primary RYGB surgery (meeting all criteria + approval of surgeon)
  • Able to prepare the meal replacements at home

Exclusion criteria

  • Undergoing another bariatric procedure than primary RYGB.
  • Diabetes Mellitus
  • Contraindication for the usage of Modifast meal replacements:
  • Allergy or intolerance to any substance in the used meal replacements (Soy, milk, gluten, egg, peanuts, nuts and seeds)
  • Veganism
  • Kidney failure (GFR < 90 ml/min/1.73m2), liver failure or cardiac insufficiency
  • A heart attack (myocardial infarct) in the past twelve months
  • Cancer
  • Hypokalaemia: serum potassium level <3.4 mmol/l
  • Phenylketonuria & Porphyria

Treatment and study plan

14-day Low Calorie Diet

Other

Participants will be asked to:

  • Use 4 (women) or 5 (men) Modifast meal replacements per day.
  • Daily consume a minimum of 250 grams of (raw) vegetables without dressing.
  • Daily consume 100 grams of lean meat/fish/meat analogues.
  • Daily consume two spoons of liquid oil
  • Daily drink at least 2.0 litres of water, coffee or tea without added sugar or milk, bouillon or sugar-free drinks.

Primary outcomes

  1. Operative time of the RYGB procedure

    Time frame: surgery

    Duration of the surgical procedure, retrieved from the electronic medical record

Secondary outcomes

  1. Ease of the RYGB procedure

    Time frame: surgery

    Ten aspects of the RYGB procedure will be scored on a 5-point Likert scale. The total score can range from 10 to 50, with 10 being the easiest.

    The ten aspects include:

    • Exerting force on instruments (1=very low, 5= very high)
    • Difficulty of moving the liver (1=very easy, 5=very difficult)
    • Size of the liver (1=very small, 5= very large)
    • Size of omentum (1=very small, 5= very large)
    • Difficulty of approaching pouch (1=very easy, 5=very difficult)
    • Accessibility of Treitz ligament (1=very easy, 5=very difficult)
    • Difficulty of creating pouch (1=very easy, 5=very difficult)
    • Difficulty of measuring small intestine (1=very easy, 5=very difficult)
    • Difficulty of entero-entero connection (1=very easy, 5=very difficult)
    • Difficulty of abdominal wall hernia repair (1=very easy, 5=very difficult)

  2. Appearance of the patient's liver

    Time frame: surgery

    Includes four images of the liver in different stages (1= healthy, 2= fatty liver, 3= fatty liver with inflammation, 4= liver cirrhosis). Surgeons will be asked to choose the image that best matches the appearance of the patient's liver.

  3. Post-operative weight loss

    Time frame: 4 weeks, 3, 6 months and 1, 2, 3, 4, 5 years after surgery

    Body weight measurements to assess weight loss after surgery

Other outcomes

  1. Feasibility of the diet

    Time frame: During the 14-day intervention period

    Feasibility will be assessed via questionnaires

  2. Compliance of the diet

    Time frame: During the 14-day intervention period

    Compliance will be assessed via food records

  3. Complication rate

    Time frame: First 30 days post-surgery

    All short term complications during the first 30 days will be recorded and classified according to the Clavien-Dindo classification

  4. Wound healing

    Time frame: 4 weeks

    Degree of wound healing post-surgery will be checked based on appearance on a 5-point Likert scale.

Sponsors and collaborators

Lead sponsor

Rijnstate Hospital

Other

Registry information

Important dates

Study start
2020
Primary completion
2022
Study completion
2027
First posted
Jun 16, 2020
Registry last updated
Jan 3, 2025

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.