Closure of cerebrospinal fluid leaks prevents ascending bacterial meningitis.

Introduction: Endoscopic surgery of the anterior skull base has become the standard procedure for the repair of cerebrospinal fluid (CSF) leaks of various origins. Closure of the leaks is believed to prevent ascending meningitis, although no report has specifically shown this.

Material And Methods: Retrospective chart study of 39 patients who underwent endoscopic skull base surgery from 1/1993 to 11/2002.

Setting: Tertiary University Hospitals.

Outcome Measurement: Incidence of ascending meningitis after endoscopic skull base repair in patients with anterior skull base defects associated or not with meningitis and CSF leak.

Results: Forty-one endoscopic repairs of anterior skull base defects of various origins were performed in 39 patients. Fifteen (36.5%) had suffered bacterial meningitis before surgery. Mean follow-up was 65 months (range 22-120). The defect was repaired using an "underlay" technique with lyophilized dura (n=11) or fascia lata (n=30), and covered with free mucosal grafts from either the middle or the inferior turbinates. Closure was achieved in 40/41 cases at first attempt. No recurrence of ascending bacterial meningitis was observed during follow-up in any of the fifteen patients who had previously presented with a CSF leak or skull base defect with meningitis. Also, no new bacterial meningitis occurred in all other patients. One case of meningoencephalocele of the lateral sphenoid wall developed a recurrent CSF fistula associated with bacterial meningitis two years after endoscopic repair, requiring endoscopic revision surgery. No patient received vaccination in this series.

Discussion: Closure of active CSF leaks and reconstruction of skull base defects without CSF-leak in patients with prior ascending bacterial meningitis seem to provide excellent long-term results with neither recurrence of ascending meningitis nor incidence of meningitis in the other patients, unless a CSF leak re-appears. Conservative treatment of CSF leaks may lead to bacterial meningitis, therefore surgical closure of leaks or defects at the skull base should be considered treatment of choice to prevent ascending meningitis.