NCT07639502Completed
Impact of Reverse Trendelenburg on ONSD in Obesity Surgery
Effect of Pre-pneumoperitoneum Reverse Trendelenburg Positioning on Optic Nerve Sheath Diameter During Bariatric Surgery: A Prospective Randomized Controlled Trial
Source: ClinicalTrials.gov · Last updated 14 Jul 2026
Brief summary (registry, in English)
This prospective randomized controlled trial aims to investigate the effect of reverse Trendelenburg positioning applied before pneumoperitoneum on optic nerve sheath diameter (ONSD) and, consequently, intracranial pressure during laparoscopic bariatric surgery. Patients will be randomly assigned to two groups, and perioperative changes in ONSD will be compared between the groups. The primary hypothesis of the study is that applying the reverse Trendelenburg position before pneumoperitoneum may attenuate ONSD enlargement and thereby help prevent increases in intracranial pressure.
- Status (registry)
- Completed
- Study type
- Interventional
- Enrollment
- 90 (actual)
- First submitted
- 1 Jun 2026
- Start date
- 1 Jan 2026
- Primary completion date
- 15 Apr 2026
- Lead sponsor
- Bagcilar Training and Research Hospital
- Diseases
- Obesity
- NCT number
- NCT07639502
What you commit to
- Study type: Interventional
- Participants enrolled: 90
- From 1 Jan 2026 to the primary completion date, 15 Apr 2026
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study design.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- History of ophthalmologic disease that may affect optic nerve sheath diameter (ONSD) measurements (e.g., glaucoma, optic neuritis, optic nerve tumors, severe ocular trauma, previous ocular surgery).
- Emergency surgery.
- Conversion from laparoscopic to open surgery. Intraoperative events requiring deviation from the study protocol.
Other illness
- Known intracranial pathology, including intracranial hypertension, hydrocephalus, intracranial mass lesions, or cerebrovascular disease.
- Neurological disorders that may influence intracranial pressure measurements.
- Severe cardiopulmonary disease (e.g., decompensated heart failure, severe pulmonary hypertension, severe chronic obstructive pulmonary disease).
Age
- Age younger than 18 years or older than 65 years.
Other
- Refusal or inability to provide written informed consent.
- Pregnancy.
- Inability to obtain adequate ocular ultrasonography images for ONSD measurement.
Who the study is looking for
- Age between 18 and 65 years.
- American Society of Anesthesiologists (ASA) physical status I-III.
- Body mass index (BMI) ≥ 40 kg/m² and scheduled for elective laparoscopic bariatric surgery.
- Ability to provide written informed consent.
- Willingness to participate in the study and comply with study procedures.
Age in the registry: 18 years to 65 years · Sex: All · Accepts healthy volunteers
Sites (1)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Bagcılar Training Research Hospital Coordinator of this site? Confirm its status | Istanbul | Turkey (Türkiye) | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.