CT-Based Blood Burden Scores for Predicting Shunt-Dependent Hydrocephalus After Aneurysmal Subarachnoid Hemorrhage: A Comparative Analysis of Quantitative and Qualitative Scoring Systems.

Abstract

Shunt-dependent hydrocephalus represents a major complication of aneurysmal subarachnoid hemorrhage (aSAH), yet no universally adopted CT-based prediction tool exists. Fisher-based scales suffer from a ceiling effect limiting discriminative capacity. Whether quantitative scores offer superior performance and whether blood compartments contribute differentially to shunt dependency remains unknown. Retrospective single-center study of 285 consecutive aSAH patients (January 2020-December 2025). Six scores assessed on admission CT: Fisher, Modified Fisher, Hijdra Cisternal, Hijdra Ventricular, Hijdra Total, and Modified Hijdra Total. Primary outcome was VP shunt dependency. Discriminative performance assessed using ROC analysis; pairwise comparisons via DeLong's method. Hijdra Total achieved highest AUC (0.763, 95% CI 0.706-0.818), followed by Hijdra Cisternal (0.736), Modified Hijdra Total (0.733), and Hijdra Ventricular (0.725). All Hijdra-based scores outperformed Fisher (0.625) and Modified Fisher (0.648) (all p<0.001). No significant difference between Hijdra Total and Modified Hijdra Total (p=0.094), or between ventricular and cisternal subscores (p=0.762). At optimal Hijdra Total cutoff ≥32: sensitivity 71%, specificity 73%, PPV 67%, NPV 76%. Hijdra Total outperforms Fisher-based scales for VP shunt prediction. No significant difference was observed between cisternal and ventricular blood compartments in predicting shunt dependency, consistent with the hypothesis that total blood burden rather than anatomical distribution drives hydrocephalus risk. This contrasts with vasospasm where ventricular exclusion improves performance, supporting compartment-specific score selection by clinical endpoint.