Association of external ventricular drain duration and output with cerebral infarct risk in aneurysmal subarachnoid hemorrhage

Background: The optimal duration of external ventricular drain (EVD) in patients with aneurysmal subarachnoid hemorrhage (aSAH) is debatable. We sought to determine the association of EVD duration and output with outcomes, including cerebral infarct.

Methods: We performed a retrospective study of a prospectively collected cohort of consecutive patients with aSAH who were admitted to an academic center from 2016 to 2023. Multivariable logistic regression was used to determine the association of EVD duration and output with outcomes, including cerebral infarct prior to discharge, poor outcome defined as 3-month modified Rankin Scale (mRS) 3-6 and ventriculoperitoneal (VP) shunt placement.

Results: We reviewed 429 cases of aSAH and included 306 patients who received EVD with mean age 57.9 years (SD 13.9), 67 % female and 69 % white. Longer EVD duration was associated with higher odds of cerebral infarct (OR 1.04 for each day increase, 95 % CI 1.01-1.07; p = 0.003) independent of age, sex, Hunt and Hess grade and modified Fisher scale. Longer EVD duration was also associated with poor functional outcomes (OR 1.03 per each day increase, 95 % CI 1.01-1.06; p = 0.019) and VP shunt placement (OR 1.15 per each day increase, 95 % CI 1.09-1.21; p < 0.001) independent of other predictors. There was no independent association between daily EVD output and outcomes.

Conclusions: Although longer EVD duration was associated with more cerebral infarcts and poor outcomes in patients with aSAH, no causal interferences can be drawn. Larger multicenter prospective studies are needed to better strategize the mode, duration, and amount of CSF drainage in aSAH patients.