blood removal from cerebrospinal fluid (CSF) in post-subarachnoid hemorrhage patients
PRESENTING AUTHORS FULL NAME: Mohammadreza Khani1, Lucas R. Sass1, M. Keith Sharp2, Aaron R. McCabe3, Laura M. Zitella Verbick3, Shivanand P. Lad4, Bryn A. Martin1*
INSTITUTION: 1Department of Biological Engineering, The University of Idaho. 2Department of Mechanical Engineering, University of Louisville. 3Minnetronix Neuro, Inc. 4Department of Neurosurgery, Duke University School of Medicine
Background: It has been hypothesized that blood removal from cerebrospinal fluid (CSF) in post-subarachnoid hemorrhage patients may reduce the risk of related secondary brain injury. In this study, we formulated subject-specific computational fluid dynamics (CFD) and in vitro models to investigate the impact of a dual-lumen catheter-based CSF filtration system, called Neurapheresis™ therapy, on blood removal from CSF compared to lumbar drain.
Methods: A subject-specific CSF flow rate was applied as a source of oscillation with constant ventricular CSF production of 0.2 mL/min. The dual-lumen Neurapheresis catheter geometry was added to the model within the posterior spinal subarachnoid space (SAS) with the aspiration port located at L2 and return port located at T2 vertebral level. Neurapheresis flow aspiration rate was 2.0 (mL/min), with a constant return rate of 1.8 (mL/min) and 0.2 (mL/min) drainage for lumbar drain. An in vitro CSF model was constructed with an identical fluid domain geometry.
Results: Results showed that 85% of the spinal SAS was cleared within one hour with Neurapheresis therapy applied in comparison to 50% clearance after 24-hour with lumbar drain. Intracranial clearance was 66% for both cases. Linear regression analysis of in vitro and CFD showed R2=0.9, while the speed of clearance error was less than 4% after 24 hours (50% CFD vs 46% in vitro).
Conclusion: Neurapheresis therapy was found in these models to significantly increase CSF clearance compared to lumbar drain. Clearance was greatest between the aspiration and the return ports with the Neurapheresis therapy.