Association between subarachnoid space depth and neurosurgical intervention during conservative observation in children with minor subdural hematoma: a retrospective cohort study.

The existing literature on subdural hematomas (SDH) primarily focused on surgically treated cases. However, minor SDH remain unexplored. This study aims to investigate the association between subarachnoid space depth and neurosurgical intervention in children with minor SDH. Patients (age < 3 years) with minor SDH between June 2015 and June 2024 at the Children's Hospital of Soochow University were included. Patients with subarachnoid space depth ≥ 3 mm were classified into the ESS group. In total, 277 patients with minor SDH were included, of whom 100 (36.1%) had ESS. During conservative observation, 22 (7.94%) patients received a neurosurgical intervention. Patients with ESS had an adjusted odds ratio (OR) of 6.07 (95% CI: 1.57-23.4; p = 0.009) for receiving neurosurgical intervention. In subgroup analyses, the subarachnoid space depth was associated with the neurosurgical intervention in patients who were male (OR = 7.33; 95% CI: 1.96-27.39), infants (OR = 5.84; 95% CI: 1.63-20.85), those with an open fontanelle (OR = 4.92; 95% CI: 1.57-15.41), and those without a history of seizures (OR = 5.87; 95% CI: 1.81-19.03). The association was robust in sensitivity analyses. Subdural hematohygroma significantly mediated the association (p = 0.016), accounting for 16.79% of the correlation. The subarachnoid space depth may be a significant risk factor for neurosurgical intervention during conservative observation in children, particularly infants, with minor SDH.