Objective: Hydrocephalus after subarachnoid hemorrhage (SAH) requires temporary cerebrospinal fluid (CSF) drainage using an external ventricular drain (EVD). This drain is removed if patients pass a clamp trial, or a ventriculoperitoneal shunt (VPS) is placed. Little is known about the risk factors for delayed VPS placement in patients who pass a clamp trial and have their EVD removed. In order to explore the risk factors associated with delayed VPS placement, we studied a retrospective cohort of SAH patients at our institution.
Methods: We performed a retrospective analysis of SAH patients who had an EVD placed between January 2008 and June 2012 at our institution. We extracted demographic, imaging, and CSF data from the medical record and analyzed risk factors associated with delayed VPS placement.
Results: Of 91 patients who passed a clamp trial and had their EVD removed, 12 (13%) required delayed VPS placement at a median of 54 (interquartile range: 15-75) days after EVD removal. After multivariate analysis, risk factors for delayed VPS placement included increased CSF protein concentration within the first 7 days of EVD placement (OR: 1.02, CI: 1-1.04, p=0.023) and increased third ventricular diameter prior to EVD removal (OR: 1.59, CI: 1.11-2.6, p=0.026).
Conclusion: Patients with increased CSF protein concentration at time of EVD placement and those with increased third ventricular diameter at time of EVD removal should be carefully monitored for development of delayed hydrocephalus.
Keywords: CSF dynamics; cerebrospinal fluid shunt; hydrocephalus; subarachnoid hemorrhage.