Official title: Intravenous Versus Perineural Ondansetron as an Adjuvant in Autonomic Neural Blockade for Laparoscopic Sleeve Gastrectomy: A Two-Center, Randomized, Double-Blind, Non-inferiority Trial Summary: This prospective randomized non-inferiority study will be conducted to compare the analgesic anti-emetic effects of intravenous ondansetron versus perineural ondansetron in patients undergoing laparoscopic sleeve gastrectomy. Conditions: Ondansetron, Laparoscopic, Gastrectomy Keywords: Ondansetron, Laparoscopic, Gastrectomy Study type: INTERVENTIONAL Primary purpose: PREVENTION Phases: NA Enrollment: 170 (ESTIMATED) Status: RECRUITING Completion: 2026-12-17 (ESTIMATED)