Infections After Cranial Neurosurgery: Prospective Cohort of 103 Episodes Treated According to a Standardized Algorithm

Abstract

Objective: The optimal surgical and antimicrobial treatment for intracranial infections after neurosurgery is unknown. We investigated the clinical, laboratory, and microbiological characteristics of intracranial infections after neurosurgery. In addition, treatment outcome in patients treated according to a standardized algorithm was evaluated.

Methods: Consecutive patients with extradural, intradural, and device-related infections after cranial neurosurgery were included prospectively. A standardized antimicrobial and surgical treatment regimen was applied. The probability of infection-free survival was estimated by using the Kaplan-Meier survival method. Survival curves between groups were compared by using log-rank Mantel-Cox test.

Results: Of 103 infections, 58 (56%) were extradural, 33 (32%) intradural, and 12 (12%) device-associated. Foreign material was involved in 98 infections (95%), including 78 bone flaps or fixation devices, 41 duraplasties, 17 external drains, and 15 functional devices. The median duration from primary surgery until infection diagnosis was 33 days (range, 6-1132 days). In total, 69 infections (67%) were monomicrobial, 26 (25%) polymicrobial, and 8 (8%) culture-negative. Ninety of 103 patients (90%) underwent surgical intervention, of whom foreign material was retained in 24 (23%). The probability of infection-free survival was 87% after 12 months (95% confidence interval 77%-93%). Nonadequate antimicrobial therapy was associated with treatment failure (5% vs. 70%, P < 0.001), which remained significant in the multiple logistic regression model (P = 0.01).

Conclusions: Most (95%) intracranial infections were associated with foreign material and required surgical intervention and biofilm-active treatment. Via a standardized treatment approach, the infection-free survival after 12 months was good (87%), independent of the infection site or type of micro-organism.

Keywords: Craniotomy; Neurosurgery; Outcome; Surgical-site infection; Treatment.