Preoperative stomach ultrasound and BMI link in laparoscopic weight-loss surgery

The Correlation of Gastric Residual Volume Detected by Preoperative Gastric Ultrasonography With Body Mass Index and Aspiration Risk in Patients Undergoing Laparoscopic Bariatric Surgery

We will test whether preoperative stomach ultrasound measurements and BMI can predict aspiration risk in adults having elective laparoscopic weight-loss surgery.

Quick facts

• Study type: Observational
• Enrollment: 60 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: Fatih Sultan Mehmet Training and Research Hospital (other)
• Locations: 1 site (Istanbul, Istanbul)
• Trial ID: NCT07032207 on ClinicalTrials.gov

What this trial studies

Adults scheduled for elective laparoscopic bariatric surgery will have a bedside gastric ultrasound in the anesthesia preparation room, first supine then in the right lateral decubitus position. Operators will measure antral AP and CC diameters, calculate cross-sectional area and estimate gastric residual volume using the Perlas formula (including age). Patients will be classified as low or high aspiration risk based on antral content and a threshold of 1.5 mL/kg gastric residual volume. The study includes adults 18–65 years old with BMI >35 kg/m² in ASA II–III and excludes those with upper GI abnormalities, recent GI bleeding, prior upper GI surgery, pregnancy, uncontrolled diabetes, or emergency surgery.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18–65 with BMI >35 kg/m² in ASA II–III who are scheduled for elective laparoscopic bariatric surgery and can provide informed consent.

Not a fit: Patients with upper GI anatomic abnormalities, prior stomach/esophagus surgery, pregnancy, uncontrolled diabetes, emergency surgery, or advanced organ failure were excluded and are unlikely to benefit from the findings.

Why it matters

Potential benefit: If successful, this approach could help anesthesiologists better identify which obese patients are at higher risk of aspiration and tailor fasting or airway management accordingly.

How similar studies have performed: Ultrasound-based estimation of gastric volume using formulas such as Perlas et al. has been validated in prior work, but data specifically linking BMI to aspiration risk in bariatric laparoscopic patients remain limited.

Eligibility criteria

Inclusion Criteria:

* Patients who will undergo bariatric surgery under general anesthesia in elective conditions
* Patients in ASA II-III groups, with BMI \> 35 kg/m², and aged between 18-65 years
* Patients who have provided informed consent

Exclusion Criteria:

* Patients under 18 years of age, over 65 years of age, or in ASA IV-V groups
* Pregnancy
* Patients with upper gastrointestinal (GI) abnormalities such as hiatal hernia and gastric tumors
* Patients with a recent history of upper GI bleeding (within the last 12 months), previous stomach and esophagus surgeries, or abnormal anatomy of the upper gastrointestinal tract
* Patients using medications that affect gastric motility or other related conditions
* Patients with uncontrolled diabetes
* Patients who require emergency surgery
* Patients with advanced cardiac, renal, pulmonary, or hepatic failure
* Patients who refuse to participate and do not provide informed consent

Where this trial is running

Istanbul, Istanbul

• Fatih Sultan Mehmet Training and Research Hospital — Istanbul, Istanbul, Turkey (Türkiye) (RECRUITING)

Study contacts

• Study coordinator: BUSRA TANACIOGLU, Research Assistant M.D

Conditions: Obesity, Gastric Ultrasound, Gastric Residual Volume, Body Mass Index, obesity, gastric ultrasound, gastric residual volume, body mass index