title: The Autoclaving of Autologous Bone is a Risk Factor for Surgical Site Infection After Cranioplasty.
abstract: BACKGROUND
  This retrospective study was designed to evaluate the effectiveness of autoclaving for the prevention of surgical site infection (SSI) after cranioplasty.
  
  
  METHODS
  Patients who underwent cranioplasty with autologous bone were enrolled. SSI was defined as an infection requiring bone flap removal. Risk factors of SSI, as reported by other researchers, and microbiologic features of SSI were analyzed. All bone flaps were preserved in a deep freezer (-70°C). Autoclaving of the preserved autologous bone flap before cranioplasty was performed for 5 minutes at 135°C in the 26 patients.
  
  
  RESULTS
  Eighty patients were enrolled. The mean age was 53.3 years and the male/female ratio was 3:2. Causes of craniectomy included trauma (n = 37) and nontrauma (n = 43). The mean time interval between craniectomy and cranioplasty was 49.7 days. The SSI rate after cranioplasty with autologous bone was 17.5% (n = 14). In univariate analysis, the cranioplasty operation time (P = 0.09) and the use of autoclaved bone (P = 0.00) were supposed to be risk factors for SSI. The use of autoclaved autologous bone was found to be the only risk factor of SSI (P = 0.01; hazard ratio = 8.88) in binary logistic regression analysis. Non-methicillin-resistant Staphylococcus aureus (MRSA) causes were more frequent in the autoclaved group (MRSA, 30%; non-MRSA, 70%) compared with the nonautoclaved group (MRSA, 100%) (P = 0.07). A microscopic examination showed that autoclaving after long-term cryopreservation may result in a loss of bone viability.
  
  
  CONCLUSIONS
  Autoclaving of autologous bone causes SSI after cranioplasty and it seems to increase the risk of non-MRSA infection by normal skin flora.
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Seong-Hyun
authors.initials: SH
authors.lastname: Wui
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea. Electronic address: quintus@hotmail.co.kr.
authors.forename: Kang Min
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Pathology, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Ryu
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Inkyeong
authors.initials: I
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Jiha
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Choonghyo
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Kangwon National University Hospital, Chuncheon-si, Gangwon-do, Republic of Korea.
authors.forename: Seoungwoo
authors.initials: S
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D016025:Bone Transplantation / Q000009:adverse effects* / Q000592:standards; D003399:Craniotomy / Q000009:adverse effects* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013524:Surgical Flaps / Q000009:adverse effects* / Q000592:standards; D013530:Surgical Wound Infection / Q000209:etiology* / Q000517:prevention & control
keywords: Autoclave; Cranioplasty; Infection