Objective  To explore the risk factors of complicated intracranial infection after endonasal endoscopic skull base surgery (EESBS) and pathogen characteristics.

  Methods  A total of 813 patients with EESBS were enrolled. The incidence rate of postoperative intracranial infection was recorded. According to postoperative intracranial infection conditions, they were divided into intracranial infection group and control group, and the single factor of intracranial infection was analyzed. Statistically significant indicators in the univariate analysis were included in the Logistic multiple regression analysis. The distribution characteristics of pathogens including Gram-positive bacteria (G⁺) and Gram-negative bacteria (G^-) in patients with intracranial infection after EESBS were analyzed.

  Results  In the 813 patients with EESBS, 39 cases (4.80%) had postoperative intracranial infection. Analysis of the single factor of intracranial infection revealed that sinus surgery ≥ 2 times, postoperative CSF rhinorrhea, skull base reconstruction, preoperative use of preventive antibiotics were significantly associated with intracranial infection (P < 0.05). Logistic multiple regression analysis showed that skull base surgery ≥ 2 times, postoperative CSF rhinorrhea, skull base reconstruction, and preoperative use of preventive antibiotics were risk factors for intracranial infection. Totally 52 pathogenic bacteria were isolated from CSF in 39 patients with intracranial infection, including 32 strains of (61.54%) G⁺ and 20 strains (38.46%) of G^-.

  Conclusion  High-risk patients with intracranial infection should be confirmed in time, and targeted preventive measures and antibiotics should be taken to reduce the incidence rate of intracranial infection.