Transabdominal and Laparoscopic Ultrasound in a Bariatric Setting
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Diagnostic procedures.
- Who it may be relevant to
- Registry conditions: Gallstone Disease, Ultrasonic Diagnosis, Bariatric Patients Undergoing Bariatric Surgery. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Denmark
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Transabdominal and Laparoscopic Ultrasound in a Bariatric Setting: Utility and Diagnostic Accuracy
Overview
Every year, many patients undergo weight-loss (bariatric) surgery. While this surgery leads to significant and intended weight loss, it also increases the risk of developing gallstones or other gallbladder problems. Approximately one in five patients later requires a second operation to remove the gallbladder. This type of surgery carries a higher risk of complications and reoperations compared with gallbladder surgery performed in the general population. Preventive treatment may help reduce this risk. One option is medical treatment with Ursochol, which has been shown to lower the risk of developing gallstones after bariatric surgery. However, this treatment is only effective in patients who have not already developed gallstones before surgery. This means patients need a reliable preoperative ultrasound examination of the gallbladder. Unfortunately, performing ultrasound can be technically challenging in patients with obesity, making it harder to detect small stones or other abnormalities. The goal is therefore to improve the examination of the gallbladder in patients undergoing bariatric surgery in order to better identify who may benefit from preventive treatment. The study The investigators are comparing two types of ultrasound examination of the gallbladder: * Standard ultrasound performed on the outside of the abdomen using a handheld probe. * Laparoscopic ultrasound performed during bariatric surgery using a small ultrasound probe placed inside the abdomen, typically placed on the liver near the gallbladder. It is of interest to find out whether the ultrasound performed during surgery finds more: * Gallstones * Sludge * Small stones (microlithiasis) * Thickening of the gallbladder wall By improving detection, the investigators aim to better guide preventive treatment and reduce the need for future gallbladder surgery.
Detailed description
1. TITLE Transabdominal and Laparoscopic Ultrasound in a Bariatric Setting 2. BACKGROUND AND RATIONALE
2.1 Clinical Background Bariatric surgery is an established and effective treatment for severe obesity. In Denmark, approximately 2,000 bariatric procedures are performed annually. These procedures result in significant and intended weight loss and improvement in metabolic comorbidities. However, rapid weight loss is associated with an increased risk of gallstone formation.
Gallstone disease is one of the most common postoperative complications following bariatric surgery. Approximately 10% of patients undergo cholecystectomy within two years after surgery, increasing to up to 20% within ten years. Importantly, cholecystectomy in patients who previously underwent bariatric surgery is associated with:
• Increased risk of surgical complications
• Higher rates of reoperation * More technically complex procedures * Increased risk of bile duct injury In patients with Roux-en-Y gastric bypass, management of biliary tract disease is particularly challenging due to altered gastrointestinal anatomy, which complicates endoscopic access (e.g., ERCP).
2.2 Preventive Treatment and Diagnostic Challenge Prophylactic treatment with ursodeoxycholic acid (Ursochol) has been shown to significantly reduce the risk of symptomatic gallstone disease in the first two years after bariatric surgery.
However:
• Ursochol is only effective in patients who do not already have gallstones.
• Therefore, accurate preoperative detection of gallstones is essential.
Conventional transabdominal ultrasound (TAUS) is the standard imaging modality for gallbladder evaluation. However, in patients with severe obesity: * Ultrasound penetration is limited * Image quality may be reduced * Small stones and sludge may be overlooked * Sensitivity may be as low as 62-68%
Thus, diagnostic uncertainty may lead to:
• Under-treatment (missed stones)
• Over-treatment (inappropriate prophylaxis)
• Inconsistent national implementation
2.3 Rationale for Laparoscopic Ultrasound (LUS)
Laparoscopic ultrasound (LUS) allows:
• Direct placement of the probe on the liver surface
• Shorter acoustic distance
• Higher image resolution
• Potentially improved detection of subtle pathology
• Fewer hospital visits for the patients prior to surgery
Only one prior study has directly compared TAUS and LUS in this population. That study suggested higher overall pathology detection with LUS, but lacked:
• Histological confirmation
• Sample size justification * Assessment of microlithiasis * Gallbladder wall measurements * Formal evaluation of interobserver agreement within each ultrasound modality
Therefore, a well-designed prospective paired diagnostic study is warranted. 3. OBJECTIVES
3.1 Primary Objective To compare the diagnostic detection rate of gallbladder pathology between transabdominal ultrasound (TAUS) and laparoscopic ultrasound (LUS) in patients undergoing bariatric surgery.
3.2 Secondary Objectives
1. To evaluate interobserver agreement within TAUS and LUS examinations 2. To compare examination time between modalities 3. To assess image quality 4. HYPOTHESES
1\. Laparoscopic ultrasound detects significantly more gallbladder pathology than transabdominal ultrasound.
2\. LUS has lower interobserver variability compared to TAUS.
5\. STUDY DESIGN Prospective observational diagnostic comparative study with paired within-patient design.
Each participant undergoes:
* Two independent TAUS examinations * Two independent LUS examinations
All examinations are performed blinded and independently.
No randomization is performed.
No experimental interventions are introduced.
6\. STUDY PROCEDURES
6.1 Preoperative Phase
Participants undergo:
• Two transabdominal ultrasounds
Interventions
- Diagnostic test Diagnostic procedures
In the same patients, we will do both transabdominal and laparoscopic ultrasound
Primary outcome measures
- Gallbladder pathology (yes / no) [Time frame: From preoperative ultrasound (within 31 days before surgery) to laparoscopic ultrasound during bariatric surgery]
Secondary outcome measures (1)
- Interobserver variability [Time frame: From preoperative ultrasound (within 31 days before surgery) to laparoscopic ultrasound during bariatric surgery]
Eligibility criteria
Inclusion criteria
- Age ≥18 years
- Scheduled for bariatric surgery
- Able to provide informed consent
Exclusion criteria
- Previous cholecystectomy
- Previous biliary surgery
- Previous liver surgery
- Inability to provide informed consent
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Diagnostic
Study locations
Denmark · 1 center
- Esbjerg og Grindsted Sygehus — Esbjerg
Identifiers
NCT: NCT07453186 · EsbjergH