The objective of this feasibility study is to demonstrate the safety and feasibility of using an investigational extracorporeal system and catheter to filter hemorrhagic cerebrospinal fluid (CSF) post subarachnoid hemorrhage (SAH) treatment, and reintroduce the CSF via the same catheter.

Inclusion Criteria:

• Age: 18 years or older
• Informed consent by the patient or his/her legally authorized representative
• Modified Fisher Grade 2, 3, or 4
• Hunt & Hess I-III
• First aneurysmal SAH that has been confirmed by Angio, CTA or MRA
• Patient is ≤ 48 hours post bleeding event
• World Federation of Neurosurgeons (WFNS) Grades I-IV and those Grade V patients who improve to Grade IV or less after ventriculostomy.

Exclusion Criteria:

• Patients with a SAH due to mycotic aneurysm or AV malformation
• Patients who present with an acute MI or unstable angina
• Patients with uncontrolled diabetes
• Patients who present with a creatinine > 2.0mg/dl
• Imaging demonstrates supratentorial mass lesions greater than 50 cc
• Imaging demonstrates more than 5 mm of mid-line-shift associated with infarction and or edema
• Effacement of the basilar cisterns (suprasellar, ambient, chiasmatic and quadrageminal)
• Vasospasm on admission as defined by angiographic evidence
• Patients with a coagulopathy that cannot be reversed per the professional discretion of the investigator
• Thrombocytopenia def. platelet count < 100,000
• Patients on low molecular weight heparin e.g., Lovenox
• Patients on Clopidogrel bisulfate (Plavix) or other chronic platelet inhibitors
• Patients with a documented history of cirrhosis
• Patients who will be managed with supportive care rather than intervention
• Obstructive hydrocephalus i.e., non-communicating
• Pregnancy
• History of posterior fusion hardware that would interfere with placement of the catheter
• Pre-existing Lumbar Drain
• Local skin infections or eruptions over the puncture site
• Signs of systemic infection/sepsis or pneumonia
• Lumbar puncture within 6 hours
• Concurrent participation in another study which is not observational or retrospective in nature without prior approval from the Sponsor