Neurosurg Rev. 2026 Jun 19;49(1):452. doi: 10.1007/s10143-026-04349-z.
ABSTRACT
BACKGROUND: Chronic subdural hematoma (CSDH) remains a delayed complication after aneurysm clipping. Quantitative evidence linking postoperative pneumocephalus to CSDH is limited.
OBJECTIVE: To evaluate the association of a normalized CT index-the Air-Brain Index (ABI)-and intracranial volume (ICV) with postoperative CSDH, with prespecified sex adjustment.
METHODS: Single‑center retrospective cohort of adults undergoing clipping. Day‑1 CT underwent standardized segmentation to derive ABI (air/brain) and ICV (air + brain). Multivariable logistic regression included age and sex; sex‑stratified analyses and ROC curves assessed performance.
RESULTS: Among 68 patients, 18 developed CSDH. Higher ABI was associated with CSDH in univariable analysis; however, after adjustment for age and sex, ABI was no longer significant, whereas older age and male sex remained independent predictors.
CONCLUSIONS: Although ABI was not independently associated with CSDH after adjustment for age and sex, it demonstrated a significant univariable relationship and may serve as a descriptive postoperative marker of residual intracranial air burden for hypothesis-generating risk stratification.
PMID:42319492 | DOI:10.1007/s10143-026-04349-z