The incidence of cerebrospinal fluid leak after vestibular schwannoma surgery

Objective: To review the incidence of cerebrospinal fluid leak after vestibular schwannoma removal reported in the literature. Data Sources: MEDLINE and PubMed literature search using the terms "acoustic neuroma" or "vestibular schwannoma," and "cerebrospinal fluid leak" or "cerebrospinal fluid fistula" covering the period from 1985 to the present in the English language literature. A review of bibliographies of these studies was also performed. Study Selection: Criteria for inclusion in this meta-analysis consisted of the availability of extractable data from studies presenting a defined group of patients who had undergone primary vestibular schwannoma removal and for whom the presence and absence of cerebrospinal fluid leakage was reported. Studies reporting combined approaches were excluded. No duplications of patient populations were included. Twenty-five studies met the inclusion criteria. Data Extraction: Quality of the studies was determined by the design of each study and the ability to combine the data with the results of other studies. All of the studies were biased by their retrospective, nonrandomized nature. Data Synthesis: Significance (p < 0.05) was determined using the χ² test. Conclusions: Cerebrospinal fluid leak occurred in 10.6% of 2,273 retrosigmoid surgeries, 9.5% of 3,118 translabyrinthine surgeries, and 10.6% of 573 middle fossa surgeries. The type of cerebrospinal fluid leak was not associated with surgical approach. Meningitis was significantly associated with cerebrospinal fluid leak (p < 0.05). Age and tumor size were not associated with cerebrospinal fluid leak.