Risk factors for surgical site infection after craniotomy: a prospective cohort study.

Background: Although surgical site infection after craniotomy (SSI-CRAN) is a serious complication, risk factors for its development have not been well defined. We aim to identify the risk factors for developing SSI-CRAN in a large prospective cohort of adult patients undergoing craniotomy.
Methods: A series of consecutive patients who underwent craniotomy at a university hospital from January 2013 to December 2015 were prospectively assessed. Demographic, epidemiological, surgical, clinical and microbiological data were collected. Patients were followed up in an active post-discharge surveillance programm e for up to one year after surgery. Multivariate analysis was carried out to identify independent risk factors for SSI-CRAN.
Results: Among the 595 patients who underwent craniotomy, 91 (15.3%) episodes of SSI-CRAN were recorded, 67 (73.6%) of which were organ/space. Baseline demographic characteristics were similar among patients who developed SSI-CRAN and those who did not. The most frequent causative Gram-positive organisms were Cutibacterium acnes (23.1%) and Staphylococcus epidermidis (23.1%), whereas Enterobacter cloacae (12.1%) was the most commonly isolated Gram-negative agent. In the univariate analysis the factors associated with SSI-CRAN were ASA score > 2 (48.4% vs. 35.5% in SSI-CRAN and no SSI-CRAN respectively, p  = 0.025), extrinsic tumour (28.6% vs. 19.2%, p  = 0.05), and re-intervention (4.4% vs. 1.4%, p  = < 0.001). In the multivariate analysis, ASA score > 2 (AOR: 2.26, 95% CI: 1.32-3.87; p  = .003) and re-intervention (OR: 8.93, 95% CI: 5.33-14.96; p  < 0.001) were the only factors independently associated with SSI-CRAN.
Conclusion: The risk factors and causative agents of SSI-CRAN identified in this study should be considered in the design of preventive strategies aimed to reduce the incidence of this serious complication.
Competing Interests: The study only includes anonymised routine surveillance data. The need for informed consent and the information sheet were waived because the follow-up of patients undergoing craniotomy is part of the centre’s own surveillance programme. The study was approved by the Clinical Research Ethics Committee of Bellvitge University Hospital (Reference number PR334/18).Not applicable.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.