MMP9 and Subdural Effusion: For hydrocephalus, the GCS score at admission, postoperative CSF leakage, subdural effusion, and serum NLRP3, MMP‐9 and IFN‐γ levels were included in the logistic multifactorial regression analysis model, with whether the patients developed hydrocephalus after surgery as the dependent variable, and combining the results of the analyses in Table 1 (P < 0.05 for the independent variables).