Single Dose Antibiotic Protocol for Extended Endoscopic Anterior Skull Base Procedures - A Tertiary Centre Experience

Objective: To evaluate the incidence of postoperative meningitis in patients undergoing extended endoscopic endonasal anterior skull base surgery managed with a single-dose perioperative antibiotic protocol. Methods: A prospective database of consecutive extended endonasal skull base procedures requiring a nasoseptal flap reconstruction (2009-2025) was reviewed. All patients received a single perioperative dose of co-amoxiclav (or teicoplanin if penicillin-allergic). The primary outcome was meningitis within 30 days, defined by positive cerebrospinal fluid (CSF) culture or clinical diagnosis requiring intravenous antibiotics. Results: A total of 156 patients were included. Seven patients (4.5%) were treated for meningitis; six had positive CSF cultures. Eighteen patients (11.5%) developed postoperative CSF leaks requiring surgical repair, of whom six (33%) developed meningitis (p < 0.01). No dominant pathogen pattern was identified. Conclusion:In this large single-centre cohort, a single perioperative antibiotic dose was associated with meningitis rates comparable to other extended endonasal series.Postoperative CSF leak remains the strongest predictor of meningitis. These findings support antimicrobial stewardship by demonstrating that extended antibiotic courses may not be necessary in routine cases.