The risk of surgical site infection (SSI) after craniotomies or craniectomies in patients in whom contaminated bone flaps have been reimplanted has not been determined. The objectives of this study were to identify the prevalence of bone flaps with positive cultures—especially those contaminated with Propionibacterium acnes—to assess the risk of SSI after reimplanting (either during the initial operation or subsequently) bone flaps with positive cultures, and to identify risk factors for SSI following the initial craniotomies or craniectomies.
The authors conducted a retrospective review of cases in which patients underwent craniotomy/craniectomy procedures between January and October 2007 in the neurosurgery department at the University of Iowa Hospitals and Clinics. They also reviewed processes and procedures and did pulsed field gel electrophoresis of P. acnes isolates to look for a common source of contamination. They then conducted a prospective cohort study that included all patients who underwent craniotomy/craniectomy procedures between November 2007 and November 2008 and met the study criteria. For the cohort study, the authors obtained cultures from each patient's bone flap during the craniotomy/craniectomy procedures. Data about potential risk factors were collected by circulating nurses during the procedures or by a research assistant who reviewed medical records after the procedures. An infection preventionist independently identified SSIs through routine surveillance using the Centers for Disease Control and Prevention's definitions. Univariate and bivariate analyses were performed to determine the association between SSI and potential risk factors.
The retrospective review did not identify specific breaks in aseptic technique or a common source of P. acnes. Three hundred seventy-three patients underwent 393 craniotomy/craniectomy procedures during the cohort study period, of which 377 procedures met the study criteria. Fifty percent of the bone flaps were contaminated by microorganisms, primarily skin flora such as P. acnes, coagulase-negative staphylococci, and Staphylococcus aureus. Reimplanting bone flaps that had positive culture results did not increase the risk of infection after the initial craniotomy/craniectomy procedures and the subsequent cranioplasty procedures (p = 0.80). Allowing the skin antiseptic to dry before the procedures (p = 0.04, OR 0.26) was associated with lower risk of SSIs. Female sex (p = 0.02, OR = 3.49) was associated with an increased risk of SSIs; Gliadel wafer implants (p = 0.001, OR = 8.38) were associated with an increased risk of SSIs after procedures to treat tumors.
Operative factors such as the way the skin is prepared before the incision rather than the skin flora contaminants on the bone flaps may play an important role in the pathogenesis of SSIs after craniotomy/craniectomy. Gliadel wafers significantly increased the risk of SSI after procedures to treat tumors.
Abbreviations used in this paper: CHG = chlorhexidine gluconate; CoNS = coagulase-negative staphylococci; SSI = surgical site infection; UIHC = University of Iowa Hospitals and Clinics.
Address correspondence to: Jeremy D. W. Greenlee, M.D., Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242. email: firstname.lastname@example.org.
Please include this information when citing this paper: published online March 4, 2011; DOI: 10.3171/2011.1.JNS10782.
Centers for Disease Control and Prevention Division of Healthcare Quality Promotion National Center for Infectious Diseases: The National Healthcare Safety Network (NHSN) Manual: Patient Safety Component ProtocolAtlantaCenters for Disease Control and Prevention2008. 34–39
KambleRPantSSelbyGBKharfan-DabajaMASethiSKratochvilK: Microbial contamination of hematopoietic progenitor cell grafts-incidence, clinical outcome, and cost-effectiveness: an analysis of 735 grafts. Transfusion45:874–8782005
KorinekAMGolmardJLElcheickABismuthRvan EffenterreRCoriatP: Risk factors for neurosurgical site infections after craniotomy: a critical reappraisal of antibiotic prophylaxis on 4,578 patients. Br J Neurosurg19:155–1622005
MangramAJHoranTCPearsonMLSilverLCJarvisWR: Guideline for prevention of surgical site infection, 1999. Hospital Infection Control Practices Advisory Committee. Infect Control Hosp Epidemiol20:250–2801999
PadleyDJDietzABGastineauDA: Sterility testing of hematopoietic progenitor cell products: a single-institution series of culture-positive rates and successful infusion of culture-positive products. Transfusion47:636–6432007
PfallerMAChromosomal restriction fragment analysis by pulsed field gel electrophoresis–application to molecular epidemiology. IsenbergHD: Essential Procedures for Clinical MicrobiologyWashingtonAmerican Society for Microbiology1998. 651–657
VanneauxVFoïsERobinMReaDde LatourRPBiscayN: Microbial contamination of BM products before and after processing: a report of incidence and immediate adverse events in 257 grafts. Cytotherapy9:508–5132007