Thiel's embalming method with additional intra-cerebral ventricular formalin injection (TEIF) for cadaver training of head and brain surgery.

Thiel's embalming method provides natural coloration, flexibility, and tissue plasticity, and is used widely to prepare specimens for cadaver surgical training. However, this method causes brain softening, thereby restricting the cadaver surgical training of intra-cranial procedures. In this study, three cadavers were embalmed using formalin fixation, Thiel's embalming method, and Thiel's embalming method with additional intra-cerebral ventricular formalin injection, respectively. We also established rat models of the three embalming methods to develop and determine the best method for retaining adequate brain elasticity. The intra-ventricular formalin injection in the cadaver was performed through the Kocher's point, as in the classical external ventricular drain procedure. Both, the cadaver brains and rat models yielded consistent shear wave measurements and brain surface stiffness data. Notably, the Thiel's embalming method with additional intra-cerebral ventricular formalin injection yielded suitable elasticity for brain cadaver surgical training in terms of brain mobilization and surgical field deployment, and also discharged formaldehyde in undetectable quantities. To our knowledge, this is the first report in which a fixed quality, namely, brain elasticity for the performance of head and brain cadaver surgical training, has been evaluated in a cadaver subjected to the Thiel's embalming method with immersion fixation in the cerebrospinal fluid space. We conclude that the Thiel's embalming method with additional intra-cerebral ventricular formalin injection can maintain the brain elasticity, and may therefore improve the quality of head and brain cadaver surgical training safely and easily.