Resumen de Computational fluid dynamics of ventricular catheters for hydrocephalus
Marcelo Galarza y Vicentini
Introduction Based on a landmark study by Lin et al. of the two-dimensional flow in ventricular catheters (VC) via computational fluid dynamics (CFD), we studied previously the three-dimensional flow patterns of five commercially available VC. We found that the drainage of the cerebrospinal fluid (CSF) mostly occurs through the catheter’s most proximal holes.
Methods We study different prototypes of VC by means of CFD in three-dimensional (3-D) automated models and compare the fluid-mechanical results with our previous study of currently in use VC. The general procedure for the development of a CFD model calls for transforming the physical dimensions of the system to be studied into a virtual wire-frame model which provides the coordinates for the virtual space of a CFD mesh. The incompressible Navier-Stokes equations, a system of strongly coupled, nonlinear, partial differential conservation equations governing the motion of the flow field, are then solved numerically.
Results By varying the number of drainage holes and the ratio hole/segment, we obtained improved flow characteristics in five prototypes of VC. In particular, we equalized the flow pattern through the different hole segments of the new VC prototypes, as disclosed by 3-D CFD. We set five differerent principles for the design of new VC and two mathematical formulas for their flow patterns.
Conclusions New catheter designs with variable hole diameter, number of holes, and ratio hole/segment along the catheter allow the fluid to enter the catheter more uniformly along its length, thus reducing the chance that the catheter becomes occluded.
