Surgical Management of Spontaneous Lateral Cerebrospinal Fluid Leaks and Encephaloceles: A Systematic Review and Meta-Analysis

Objectives: This article aims to comprehensively examine the characteristics and outcomes of surgical repair of spontaneous lateral cerebrospinal fluid (CSF) leaks and encephaloceles.

Databases Reviewed: PubMed, Cochrane Library, Scopus, and CINAHL.

Methods: Following PRISMA guidelines, databases were searched from inception to April 3, 2024, for studies reporting patient characteristics and outcomes of surgical repair of spontaneous lateral skull base defects by surgical approach, including transmastoid (TM), middle cranial fossa (MCF), and combined TM/MCF approaches. Meta-analysis of continuous measures (age), proportions (%) (gender, surgical approach utilization, repair material utilization, surgical success rates, and complication rates), and mean differences (Δ) (pure tone average [PTA] and air-bone gap [ABG]) were performed.

Results: Fifty-one studies were included, consisting of 1,406 patients undergoing 1,493 surgeries. Of the included patients, 60.0% of all patients were females and the mean age was 57.6 years (range: 6–92 years). All included patients had a spontaneous lateral CSF leak and/or encephalocele. The most used surgical approach for lateral skull base defect repair was the MCF approach (42.5%; 95% CI: 27.5–58.4%). CSF leaks were most commonly repaired via a three-material multilayer approach (34.7%; 95% CI: 21.9–48.8%). The most frequently utilized repair material was temporalis fascia (80.9%; 95% CI: 67.85–91.2%). The surgical success rate without recurrence for lateral skull base defect repairs via all approaches was 92.8% (95% CI: 91.4–94.1%). Repair via the combined approach led to the greatest surgical success rate (95.2%; 95% CI: 91.7–97.5%), followed by the MCF approach (93.0%; 95% CI: 90.7–94.9%) and the TM approach (88.9%; 95% CI: 83.1–93.6%). Surgical success rate was significantly higher via the combined approach (Δ6.3%; 95% CI: 1.8–10.5%; p = 0.0076) and the MCF approach (Δ4.2%; 95% CI: 0.5–8.3%; p = 0.026) compared to the TM approach. There was no significant difference in success rates between the combined approach and the MCF approach (Δ2.2%; 95% CI: −1.9% to 5.3%; p = 0.26). Surgical repair across approaches significantly improved average PTA by 5.9 dB (95% CI: 3.8–8.1; p < 0.0001) and reduced ABG by 8.2 dB (95% CI: 5.9–10.5; p < 0.0001). The complication rate excluding leak recurrence for all repairs was 6.3% (95% CI: 4.9–7.8%). Complication rates per approach ranged from 3.2% (TM approach) to 8.9% (MCF approach).

Conclusion: Surgical repair of spontaneous lateral CSF leaks and encephaloceles is safe and effective, with a low probability of recurrence, improved hearing, and low complication rate. Repairs via the combined TM/MCF approach led to the lowest recurrence rate.

Fig. 1 PRISMA diagram.

Fig. 2 Forest plot of metaproportions for surgical success rate without recurrence of spontaneous CSF leak and/or encephalocele, for all surgical approaches.

Fig. 3 (A) Forest plot of mean differences for PTA following surgical repair of spontaneous CSF leak and/or encephalocele, vial all surgical approaches.

Fig. 3 (B) Forest plot of mean differences for ABG following surgical repair of spontaneous CSF leak and/or encephalocele, via all surgical approaches.

Publication History

Article published online:
07 February 2025