VIMA vs TIVA and ONSD in Laparoscopic Cholecystectomy

This prospective, single-center, randomized, open-label study compared total intravenous anesthesia (TIVA) with volatile induction and maintenance anesthesia (VIMA) in adult patients undergoing elective laparoscopic cholecystectomy. The primary objective was to evaluate whether the anesthetic technique influenced perioperative changes in optic nerve sheath diameter (ONSD), a noninvasive ultrasonographic surrogate marker of intracranial pressure.

ONSD was measured from the right eye using a 12-MHz linear ultrasound probe at six predefined perioperative time points: before induction, after tracheal intubation, after pneumoperitoneum, after reverse Trendelenburg positioning, 30 minutes after intubation, and after desufflation. Six consecutive measurements were obtained at each time point and averaged. Pneumoperitoneum pressure was maintained at 12 mmHg, reverse Trendelenburg positioning was 15°-30°, and anesthetic depth was guided by Bispectral Index monitoring.

Secondary assessments included intraoperative hemodynamic and respiratory variables, postoperative pain, nausea, vomiting, headache, diplopia, recovery time, and anesthetic drug cost. The final analysis was performed on the evaluable per-protocol population.

Inclusion criteria

• Age 18-80 years
• American Society of Anesthesiologists (ASA) physical status I-II
• Scheduled for elective laparoscopic cholecystectomy
• Provided written informed consent to participate

Exclusion criteria

• Refusal to participate
• Uncontrolled hypertension
• Uncontrolled diabetes mellitus
• History of malignancy
• Severe cardiovascular disease, including congestive heart failure or myocardial infarction
• Severe cerebrovascular disease, including previous stroke
• Hepatic dysfunction
• Renal dysfunction
• Pregnancy or lactation
• Intracranial space-occupying lesion or any condition predisposing to increased intracranial pressure
• Known optic nerve pathology