Ventriculostomy occlusion is a common complication after external ventricular drain (EVD) placement. A review of published prospective and retrospective studies indicates that approximately 1-7% of EVDs require replacement secondary to occlusion. Furthermore, in the NIS database study of over 101,000 hospitalizations in which ventriculostomy was performed, nearly 6% of patients required at least one additional ventriculostomy procedure. Studies have demonstrated non-patent EVD in 19-47% of patients, however these studies did not prospectively evaluate EVD occlusion as a primary endpoint, report on number of catheter irrigations performed, or identify risk factors for EVD occlusion.