Antibiotic prophylaxis in unrepaired CSF fistulae.

The value of antibiotic prophylaxis in patients with Cerebrospinal Fluid Leakage (CSF) is debatable. The aim of this study was to determine the value of prophylactic antibiotics in these patients. The study population comprised 253 patients with definite CSF leaks, of whom 106 received adequate antibiotic prophylaxis (Group A) and 109 were not treated with antibiotics (Group B). Thirty-eight patients were excluded from the analysis because they received antibiotics for reasons other than the CSF leakage. The two groups were closely matched for age, sex, type of CSF fistula, site, and duration of CSF leakage and presence or absence of skull fractures, but there were more patients with facial fractures and pneumocephalus in those who were treated with antibiotics. The first week meningitis rate was 6.6 and 9.17% in the treated and untreated groups, respectively, while the annual risk of meningitis was 7.6% in the treated and 11.9% in the untreated group. However, these differences did not reach significance (P > 0.05). The survival curves of meningitis-free survival were similar in the two groups, particularly during the first 4 weeks during which antibiotics were given (Log Rank test, p > 0.05). Furthermore, there were more cases of Gram-negative infection and of partially-treated meningitis in the treated group. Although this was a retrospective, non-randomized study, it confirms the conclusions of previous smaller series, that prophylactic antibiotics do not significantly reduce the risk of meningitis in these patients. It is ethically justifiable to withhold antibiotic prophylaxis in patients with CSF fistulae until a prospective controlled double blind trial has settled the question.