Abstract WP109: Association Of Cisternal Blood Clot Burden And Ventriculoperitoneal Shunt Requirement In Subarachnoid Hemorrhage

Abstract

Background: Aneurysmal Subarachnoid hemorrhage (aSAH) can be complicated by refractory hydrocephalus requiring a ventriculoperitoneal shunt (VPS). In an effort to optimize external ventricular drain (EVD) management, we sought to identify early radiographic predictors for refractory hydrocephalus requiring VPS placement. Methods: We conducted a retrospective case-control study of patients admitted for aSAH to a referral academic center from 2016 to 2021. We included those who survived their hospital course and compared radiographic features on admission non-contrast head CTs of patients who required a VPS and those who did not. We calculated modified GRAEB scores and measured total blood clot thickness (blood clot cisternal score) in the basal cisterns including interpeduncular, ambient, crural, prepontine, suprasellar, and interhemispheric cisterns plus bilateral Sylvian fissures (in mm). Binary logistic regression was used to test the association of VPS requirement with radiographic features. Receiver operating characteristics (ROC) curve analysis was performed to compare predictive accuracy of cisternal score to other predictors. Results: Our inclusion criteria yielded 176 patients (mean age of 54.9 years [SD 12.8]; 57% female, 70% white) of which 29 (16.5%) required a VPS. Cisternal score was greater in patients who required a VPS than those who did not (median 61.6 mm, IQR 49.8-74.3 mm vs 26.8mm, IQR 12.4-46.7; p<0.001). Binary logistic regression showed higher blood clot cisternal score on admission head CT scan was associated with higher odds of developing refractory hydrocephalus with VPS requirement (odds ratio 1.06 per each millimeter increase, 95% CI 1.03-1.09; p<0.001), independent of age, Hunt and Hess grades and modified GRAEB scores. Blood clot cisternal score has higher accuracy in predicting VPS requirement than modified GRAEB score (AUC 0.83, 95% CI 0.74-0.93 vs AUC 0.72, 95% CI 0.63-0.82) and other clinical or radiographic predictors on admission. Conclusions: While further validation is needed, our model suggests that blood clot cisternal score on admission head CT scan has high accuracy in predicting VPS requirement. This may allow for more efficacious and cost-effective treatment of hydrocephalus in aSAH patients.