CT Quantification of Intraventricular Hemorrhage Volume in Poor-Grade Aneurysmal Subarachnoid Hemorrhage: Impact on Mortality and Long-Term Disability

BackgroundAneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition with high morbidity and mortality, particularly in poor-grade patients (World Federation of Neurosurgical Societies grades IV-V). Intraventricular hemorrhage (IVH) is associated with worse outcomes, but its predictive value and interaction with demographic and clinical factors remain unclear.PurposeTo evaluate the prognostic value of IVH volume (IVHV) quantified on admission computed tomography (CT) in association with mortality and long-term disability, as well as its interaction with demographic and clinical variables in patients with poor-grade aSAH.MethodsWe retrospectively analyzed all consecutive patients with poor-grade aSAH and IVH that were admitted to nine Italian tertiary centers between 1 January 2015 and 31 May 2023. Bivariate and multivariable analyses were performed to identify factors associated with mortality and disability (modified Rankin Scale [mRS]). Global intracranial hemorrhage volume (GHV) as well as the volumes of ICH (ICHV), IVH (IVHV), and SAH (SAHV) were calculated by means of analytical software in a semiautomated setting. We employed an explainable machine learning approach to examine the interplay between hemorrhage volume distribution, demographic and clinical variables to define prognostic thresholds, and to develop a decision tree model.ResultsAmong 326 patients with IVH (median age 61 years [IQR: 53-70], 65.6% male), IVHV was the strongest factor independently associated with mortality and disability. An IVHV threshold of 8 mL optimized sensitivity and specificity for the outcome. Combining IVHV with age and ICHV further improved prognostic thresholds in the studied population; specificity was 92% for mortality and 71% sensitivity for disability. Adding IVHV to the SAFIRE scale significantly improved its predictive power (De Long p .008).ConclusionsIVHV is a key factor associated with mortality and disability in poor-grade aSAH with intraventricular involvement. Quantifying hemorrhage volume on admission CT is a valuable tool for improving outcome stratification and guiding clinical decision-making.