1.External ventricular drainage system for CSF drainage 2Consist of drainage bottle,bag,catheter,valve,guidewire 3.Size ... catheter on scalp, and then connect it to the drainage system.Purpose:E. V. D. catheter is used ... in continuous drainage for cerebrospinal fluid(CSF) or sludged blood during the ... circulationand prevent brain pressure ascent. External Ventricular Drainage unit