Background: Hydrocephalus (HC) after aneurysmal subarachnoid hemorrhage (aSAH) is a common sequel. Proper selection of patients in need of permanent cerebrospinal fluid (CSF) diversion is, however, not straightforward. The aim of this study was to identify predictors of CSF shunt dependency following aSAH.
Methods: We re-analyzed data acquired from aSAH patients previously enrolled in a prospective, controlled single-center clinical trial in which shunt dependency was not one of the end points. In the present study patients were allocated into two groups: those receiving a shunt (here denoted as shunt dependent) and those not receiving a shunt, based on a clinical decision process. Predictors of shunt dependency were identified by applying uni- and multivariable analysis. We tested a set of predefined possible risk factors based on the results of the clinical trial, including the impact of CSF drainage volume exceeding 1,500 ml during the 1st week after ictus.
Results: Ninety patients were included in the study. Significant predictors of shunt dependency were poor clinical grade at admission [odds ratio (OR) 4.7, 95% confidence interval (CI) 1.2-18.4], large amounts of subarachnoid blood (OR 3.8, 95% CI 1.0-14.0), large ventricular size on preoperative cerebral computer tomographic (CT) scans (OR 1.0, 95% CI 1.0-1.1), and CSF volume drainage exceeding 1,500 ml during the 1st week after the ictus (OR 16.3, 95% CI 4.0-67.1). Age ≥70 years, larger amounts of intraventricular blood, vertebrobasilar aneurysm, and endovascular treatment tended to increase the likelihood of receiving a shunt. Outcome was not significantly different between shunted and non-shunted patients.
Conclusions: In this cohort of patients with clinical grade aSAH at admission, larger amounts of subarachnoid blood and large ventricular size on preoperative cerebral CT, and CSF drainage in excess of 1,500 ml during the 1st week after the ictus were significant predictors of shunt dependency. Shunt dependency did not hamper outcome.