Subdural effusion secondary to unilateral decompressive craniectomy in patients with traumatic brain injury: Incidence, clinical characteristics, predictors and outcomes.

Background: Currently, there is a lack of literature reporting on the risk factors associated with various types of subdural effusion (SDE). The purpose of this study is to investigate the incidence, risk factors, and prognosis of different types of SDE that occur secondary to unilateral decompressive craniectomy (DC) in patients with traumatic brain injury (TBI).

Methods: A total of 417 patients who met the inclusion criteria were analyzed. The incidence, treatment, and prognosis of various types of SDE were examined. Risk factors associated with different types of SDE were identified through univariate analysis followed by multivariable logistic regression analysis.

Results: The overall incidence of SDE was 50.6 %. There was no statistically significant difference in GOS scores among the various types of SDE (P = 0.511). Age (per 10-year increase) (OR, 1.471; 95 % CI, 1.201-1.802; P < 0.001), alcoholism (OR, 2.027; 95 % CI, 1.021-4.022; P = 0.043), combined with contralateral subdural hematoma (OR, 4.874; 95 % CI, 2.676-8.878; P < 0.001), and contralateral pneumocephalus after surgery (OR, 4.051; 95 % CI, 1.837-8.934; P = 0.001) were identified as independent risk factors for the occurrence of contralateral SDE. The type of injury (acute subdural hematoma, ASDH) (OR, 1.918; 95 % CI, 1.367-2.690; P <0.001), was an independent risk factor for the occurrence of ipsilateral SDE. Combined with contralateral subdural hematoma (OR, 2.669; 95 % CI, 1.161-6.139; P = 0.021) and contralateral pneumocephalus after surgery (OR, 2.271; 95 % CI, 1.177-4.381; P = 0.014) were independent risk factors for the occurrence of interhemispheric SDE.

Conclusions: Various types of SDE do not significantly affect the prognosis of patients with traumatic brain injury (TBI). Independent risk factors for the occurrence of contralateral SDE include age, alcoholism, and the presence of contralateral subdural hematoma and contralateral pneumocephalus following surgery. The type of injury being ASDH is the only risk factor for ipsilateral SDE. Combined with contralateral subdural hematoma and contralateral pneumocephalus after surgery were independent risk factors for the occurrence of interhemispheric SDE.