Timing of cerebrospinal fluid diversion with ventriculoperitoneal shunt placement in cranioplasty reconstruction: A systematic review and meta-analysis.

Background: A substantial proportion of patients who undergo decompressive craniectomy develop hydrocephalus (HCP), necessitating both cranioplasty (CP) and cerebrospinal fluid (CSF) shunting procedures. There is wide variation in the timing and sequence of these operations. We aim to define the complication rates and types of each treatment algorithm in patients requiring both CP and CSF shunting in an effort to identify the optimal sequence of procedures. Methods: A systematic literature review and meta-analysis were performed to assess complication rates for preCP shunting, simultaneous CP-shunting, and post-CP shunting. Results: There is a significant difference in complication rates between shunt placement before CP (35% demonstrated complications, confidence interval (CI) 95%, 30.9-39.1, simultaneous ventriculoperitoneal shunt (VPS) and CP (30.8%, CI 95%, 28.4-33.3), and shunt post-CP (24.4%, CI 95%, 20.5-28.2), with the shunt post-CP cohort demonstrating the lowest percentage of all complication subtypes. There is a trend toward decreased odds of complication when CP is performed before VPS. Conclusion: This information should further strengthen existing recommendations that, whenever possible, CP is performed before VPS to potentially allow for CSF dynamics to normalize. The study population does demonstrate heterogeneity. Therefore, considerations should be made based on the clinical picture and a patient's course.