Impact of Reverse Trendelenburg on ONSD in Obesity Surgery

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.

NCT Number	NCT07639502
Lead Sponsor	Bagcilar Training and Research Hospital
Conditions	Morbid Obesity
Enrollment	90 participants
Start Date	2026-01-01
Primary Completion	2026-04-15 (estimated)
Study Completion	2026-06-01 (estimated)
Updated on ClinicalTrials.gov	2026-07-14