Finite Element Modeling of Brain Tissue Retraction for Neurosurgical Simulation

The simulation capability for intraoperative brain tissue deformation by the surgical procedures using computational Finite Element analysis is demonstrated in this paper. Our research group has been developing the patient-specific three-dimensional Finite Element brain deformation model consisting of precise anatomical structures, i.e., brain parenchyma with both gyri and sulci on the surface, falx cerebri, and tentorium, in order to evaluate brain shift during navigation surgery without additional acquisition of intraoperative imaging. In this study, both gray and white matters of the brain tissues were modeled as homogeneous nonlinear hyper-viscoelastic material. The falx cerebri with tentorium was modeled as linear elastic material which is much stiffer than the brain tissue. The skull was modeled as a rigid body. In the numerical simulation, the computation of the intraoperative cerebellum tissue deformation due to retraction by spatula for posterior fossa surgery was conducted by ABAQUS/Explicit. The illustrative results successfully demonstrate the interaction between brain tissue and spatula.