Integration of Navigation, Optical and Virtual Endoscopy in Neurosurgery and Oral and Maxillofacial Surgery

Introduction: In the past years, the virtual endoscopy system VIVENDI has been developed at the computer graphics group (GRIS) of the University of Tübingen, in cooperation with the departments of neuroradiology and neurosurgery of the University Hospital Tübingen [2]. VIVENDI provides an interactive environment for the visual simulation of endoscopic examinations, which also enable the exploration of the respective organ systems. Currently, VIVENDI is in a pre-clinical testing stage, in which it is used for pre-surgical planning of the actual intervention. Furthermore, it can be used for size measurements of anatomic features and for the volumetric assessment of cavities. In this context, it already has been successfully applied to patient datasets of the colon [7], ventricular system of the brain [3, 6], the vascular systems of the heart [1] and central nervous system [4]. Techniques and systems of intra-operative navigation are already used in the departments of neurosurgery [5, 6] and oral and maxillofacial surgery [8]. Based on a preoperative acquired stack of images (volume dataset) from 3D medical scanners (ie., CT, MRI), the referenced orientation and position of the used optical endoscope within the patient are mapped into the volume dataset, during the intervention. These navigated optical endoscopes are used for diagnostical and interventional procedures, like ventriculostomies [5, 6] or the placement of implants for a prosthetic treatment. Similar, catheter-based techniques are also used in interventional neuroradiology. A true three-dimensional, spatial representation, however, has not been used in the scope of these procedures. Note that the brain-shift phenomenon has been neglected by these approaches, due to the limited anatomical changes of the endoscopic interventions, or due to the focus on bone structures which are not effected by this phenomenon.