Risk factors analysis and Bayesian network model construction of hydrocephalus after decompressive craniectomy in patients with cerebral hernia after traumatic brain injury

Objective To screen the risk factors of hydrocephalus after decompressive craniectomy in patients with cerebral hernia after traumatic brain injury (TBI), and construct a Bayesian network model based on the risk factors. Methods A total of 77 patients with cerebral hernia after TBI who underwent decompressive craniotomy in Nanjing Tongren Hospital Affiliated to Southeast University from March 2020 to January 2022 were included. They were divided into hydrocephalus group (n = 25) and non - hydrocephalus group (n = 52) according to whether hydrocephalus was complicated after surgery. The risk factors of hydrocephalus after decompressive craniectomy in patients with cerebral hernia after TBI were analyzed by univariate and multivariate Logistic regression analyses. The Bayesian network model was constructed based on the risk factors, and the receiver operating characteristic (ROC) curve and calibration curve were drawn and Hosmer-Lemeshow goodness-of-fit test was conducted. Results In hydrocephalus group, the Glasgow Coma Scale (GCS) score at admission (t = 2.178, P = 0.032), the ratio of cerebrospinal fluid replacement after lumbar puncture (χ2 = 8.675, P = 0.003), and the level of β2 -microglobulin after operation (t = 11.146, P = 0.000) were lower than those in non-hydrocephalus group, while subarachnoid hemorrhage (χ2 = 5.901, P = 0.015), bilateral operation (χ2 = 6.441, P = 0.011), the ratio of dural unstitched during operation (χ2 = 9.759, P = 0.002), postoperative intraventricular hemorrhage (χ2 = 8.938, P = 0.003), postoperative midline displacement > 10 mm (χ2 = 7.589, P = 0.006), and intracranial infection (χ2 = 4.519, P = 0.034), as well as postoperative coma time (t = 2.709, P = 0.008) were higher than those in non - hydrocephalus group. Logistic regression analysis showed that subarachnoid hemorrhage (OR = 1.885, 95%CI: 1.432-2.240; P = 0.012), dural unstitched during operation (OR = 1.468, 95%CI: 1.215-1.930; P = 0.006), long postoperative coma time (OR = 1.574, 95%CI: 1.358-1.926; P = 0.007), postoperative intraventricular hemorrhage (OR = 1.550, 95%CI: 1.254-1.768; P = 0.010), the level of β2- microglobulin increased after operation (OR = 1.622, 95%CI: 1.165-1.840; P = 0.004) were risk factors for hydrocephalus after decompressive craniectomy in patients with cerebral hernia after TBI. Based on these 5 factors, the Bayesian network model was constructed, and the area under ROC curve was 0.886 (95%CI: 0.823-0.925, P = 0.000). The calibration curve showed that there was a good consistency between the predicted probability and the actual probability, while the Hosmer-Lemeshow goodness-of-fit test showed no significant difference (χ2 = 8.760, P = 0.232), which indicated that the model had good discrimination, calibration and accuracy. Conclusions Subarachnoid hemorrhage, dural unstitched during operation, long postoperative coma time, postoperative intra ventricular hemorrhage, and elevated β2 - microglobulin level are the risk factors for hydrocephalus after decompressive craniectomy in patients with cerebral hernia after TBI.