Skull Base Tumor Model

Introduction: Recently, the development of educational models for brain anatomy is emphasized as an important asset for acquiring practical skills. We believe there is a great need for a model that can simulate a tumoral lesion, especially in areas of challenging accessibility as in the skull base. We describe our model of preparation, placement, and removal of a tumoral lesion in the desired area of the brain.

Methods: After careful investigation of various materials that could potentially simulate a tumor, we chose a polymer for its unique intrinsic metamorphose characteristics. This polymer, initially liquid, foams when it is injected into the desired area of the brain. In the brain, the polymer transforms into its solid, tumor-like, consistency.

We used cadaveric heads previously injected with silicon. We performed different approaches to place tumors in different locations. The tumors were placed from below, leaving the skull and the brain intact so that the surgeon is able to operate on the lesion as in a real case. For instance, for tumor placement in the cerebellopontine angle, we performed an approach removing part of the clivus, passing laterally to the brainstem, and then injecting the tumor in the desired location. We performed MRIs on cadaveric heads after tumor injection for preoperative planning of the removal.

Results: A preoperative MRI allows the surgeon to study the location, the extension of the lesion, and its involvement with delicate structures. Intraoperatively, the tumor did not adhere or float in the normal brain. The tumor interacted with the brain as a real tumor, which allowed its removal with microinstruments.

Conclusion: The skull base tumor model is an effective tool to maximize technical skills and provide more practice in preoperative planning of tumor removal, which serve to better prepare a practicing neurosurgeon.