Risk Factors for Development of Chronic Hydrocephalus as a Complication of Subarachnoid Hemorrhage

Background and Purpose: Hydrocephalus is known as a common complication of subarachnoid hemorrhage (SAH) with 9 to 67% of patients affected with acute hydrocephalus and 6 to 45% which necessitated a ventriculoperitoneal shunt (VPS). The objective of this study was to measure the incidence of acute and chronic hydrocephalus and identify significant predictive factors for VPS implantation. Methods: Information ∼320 patients with newly diagnosed SAH diagnosed between 2008 and 2014 in the University Hospital of Geneva were collected. Analysis was focused on selected parameters based on review of the literature (sex, age, Fisher SAH score, hypertension status, smoking status). Patients were stratified in three groups: no hydrocephalus, acute hydrocephalus requiring external ventricular derivation (EVD), and chronic hydrocephalus needing VPS. Odds ratios (ORs) and 95% confidence interval (95% CI) were calculated and significance level estimated using Fisher exact test. Results: The incidence of EVD and VPS in our population were, respectively, 49.2 and 8.8%. Patients with Fisher score III or IV were significantly more likely to suffer acute hydrocephalus (OR 12.3; 95% CI: 3.6–41.2; p < 0.0001). Active smokers were less likely to require EVD (OR 0.40; 95% CI: 0.28–0.81); p < 0.0012). Female patients seem to need EVD slightly more often (OR 1.5, 95% CI: 0.93–2.43; p < 0.1). Fisher score of III or IV (OR 16.5; 95% CI: 3.57–76.29; p < 0.001) and insertion of EVD (OR 9.78; 95% CI: 0.31–1.85; p < 0.001) were significantly associated with a higher likelihood of chronic hydrocephalus. Age older than 65 year seem to be associated with more chronic hydrocephalus (OR 2.1, 95% CI: 0.9–4.93; p = 0.1). Presence of chronic hypertension, smoking status, and sex were not associated with SAH-induced chronic hydrocephalus. Conclusion: The results indicate that patients with a Fisher score III or higher have a significantly greater risk to develop acute or chronic hydrocephalus. EVD is a predictive factor for the development of chronic hydrocephalus. Active smokers are surprisingly less affected by acute hydrocephalus. Older age has a surprising low association with chronic hydrocephalus.