J Neurosurg 124:811-816, 2016P atients suffering from pathologies of the ventral and ventrolateral skull base often require surgical intervention. Access to the skull base traditionally required extensive tissue manipulation, but recent advances in endoscopic techniques have allowed access to the skull base using less destructive techniques via the nostril as a natural corridor. The endoscopic endonasal approach (EEA) is employed in the treatment of pituitary adenomas, Rathke's cleft cysts, ventral cranial base meningiomas, craniopharyngiomas, chordomas, olfactory neuroblastomas, and sinonasal carcinomas involving the skull base, among other pathologies. Exposure and resection often require drilling of bone adjacent to critical neurovascular structures. Cranial nerve damage can result in catastrophic disability, and vascular injury may be maiming or fatal. 6 Although residents are trained to perform the EEA by participating in operations on patients while under close supervision, critical drilling is often still done by the attending surgeon. Endoscopic endonasal drilling is somewhat unique in regard to the instruments used, the long reach required, and the restricted angulation. Cadaver training is a viable option for teaching such skills, when available. Sensory feedback from cadaver bone remains largely unchanged from live tissue, and the anatomy remains intact. However, cadavers are expensive and require specialized equipment, staff, and facilities. Availability of specimens or facilities, in most cases, precludes the use of cadavers for basic technique training; rather, their value is maximized when used by more experienced operators. Alternatively, a number of virtual reality (VR) simulators are available for EEA, but they often lack realistic drilling haptics, and the initial costs could be high.
2,10We successfully developed a physical simulator for ventriculostomy placement and demonstrated its validity. 15 Based on that experience, we also sought to create an inexpensive, high-fidelity simulator by which the drilling aspects of the EEA could be practiced by trainees once they advance to the point of surgical participation, thereby reducing the risk to patients. This endeavor, a collaborative effort of neurosurgeons, otolaryngologists, engineers, and an education/research specialist, is described in terms of simulator design, training setup, and validation process. In this paper, the authors present a physical model developed to teach surgeons the requisite drilling techniques when using an endoscopic endonasal approach (EEA) to the skull base. EEA is increasingly used for treating pathologies of the ventral and ventrolateral cranial base. Endonasal drilling is a unique skill in terms of the instruments used, the long reach required, and the restricted angulation, and gaining competency requires much practice. Based on the successful experience in creating custom simulators, the authors used 3D printing to build an EEA training model from post-processed thin-cut head CT scans, formulating the materials ...
