CDT Postgraduate Studentship in Healthcare Innovation (RCUK Digital Economy Programme grant number EP/G036861/1)
Multicompartmental Poroelastic Modelling for CSF Production and Circulation
The implementation of a Multiple-Network Poroelastic Theory (MPET) model coupled with finite-volume computational fluid dynamics (CFD) for the purpose of studying, in detail, the transport of water within a patient-specific cerebral environment reconstructed from T2 weighted MRI data has been proposed. The advantage of using the MPET representation is that it allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood. The key novelty in this model is the amalgamation of anatomically accurate choroid plexuses with their individual feeding arteries. In addition, a simple relationship relaxing the constraint of a unique permeability for the CSF compartment in order to account for the Aquaporin-4 swelling characteristics has also been incorporated into this MPET framework. The aim of this varying permeability compartment is to bring to light, for the first time, a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF to the blood system. Importantly, this model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO). The implications of treating such a clinical condition with the aid of endoscopic third (ETV) or endoscopic fourth (EFV) ventriculostomy are being considered for the first time. FVOO was applied by obstructing the bilateral foramina of Luschka, the foramen of Magendie, or a severe form of tri-exit atresia where all exits except the central canal are occluded. There is optimism that with the advancement of the MPET framework to include further details (such as aquaporin expression and various compartmental properties) in light of better experimental data, such a model can be used as a foundation for the evaluation of surgical treatment options when considering cerebral pathologies such as hydrocephalus.