Modelling of Brain Deformation After Decompressive Craniectomy.
Hyperelastic finite element models, with either an idealized cylindrical geometry or with realistic craniectomy geometries, were used to explore clinical issues relating to decompressive craniectomy. The potential damage in the brain tissue was estimated by calculating the volume of material exceeding a critical shear strain. Results from the idealized model showed how the potentially damaged volume of brain tissue increased with an increasing volume of brain tissue herniating from the skull cavity and with a reduction in craniectomy area. For a given herniated volume, there was a critical craniectomy diameter where the volume exceeding a critical shear strain fell to zero. The effects of details at the craniectomy edge, specifically a fillet radius and a chamfer on the bone margin, were found to be relatively slight, assuming that the dura is retained to provide effective protection. The location in the brain associated with volume expansion and details of the material modeling were found to have a relatively modest effect on the predicted damage volume. The volume of highly sheared material in the realistic models of the craniectomy varied roughly in line with differences in the craniectomy area.
Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK.
Tim L
TL
Fletcher
Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK.
Barbara
B
Wirthl
Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
Angelos G
AG
Kolias
Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
Hadie
H
Adams
Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
Peter J A
PJ
Hutchinson
Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK. mpfs@eng.cam.ac.uk.
Michael P F
MP
Sutcliffe
D001921:Brain / Q000473:pathology / Q000503:physiopathology; D056424:Decompressive Craniectomy; D006801:Humans; D008959:Models, Neurological; D033081:Shear Strength; D012886:Skull / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
Brain injury; FE analysis; Neurosurgery