Japanese National Questionnaire Survey in 2018 on Complications Related to Cranial Implants in Neurosurgery

Cranial implants are commonly used throughout the world, yet the data on complications remain partly clarified. The aim of this study was to gather real data in 2018 on complications related to cranial implants in neurosurgery. The survey population consisted of 1103 institutes supplying neurosurgical treatment. The survey consisted of two-stage questionnaire. First the incidence of complications was investigated, then the secondary questionnaire was e-mailed to the respondents about the detailed of the complications. As the result, the annual incidence of complications related to cranial implants was 0.558% in Japan. Titanium plate and mesh were used predominantly in craniotomy and cranioplasty, respectively. The second survey collected data on 449 cases with complications (infection: 63%, implant exposure: 46%, multiple answer). Postoperative infection was associated with male sex, brain tumor, short interval between surgery and complication, usage of ceramics, hydroxyapatite, resin, and artificial dura, hyponutrition, multiple surgeries, dirty wound, and sinusitis as patient factors, and CSF leakage, ruptured sutures, and sinus maltreatment as surgery factors. Meanwhile, long hospital stay was associated with age, male sex, mRS 3–5 before complication, short interval between initial surgery and complication, large craniotomy, long operative time, usage of ceramics and artificial dura, multiple surgeries and dirty wound as patient factors, ruptured suture as a surgical factor, and bacterial infection, especially MRSA infection, as the complication and treatment consisting of removal as complication factors. In conclusion, this is the first Japanese national survey on complications related to cranial implants in neurosurgery. It is important to recall that complications may arise years after surgery and to be aware of the risk factors associated with complications.