Image-guided surgery of the skull base using a novel miniature position/orientation sensor

Image-guided navigational systems have been a useful adjunct for minimally invasive surgery of the skull base. A novel miniature position sensor has been developed that uses an induction field for real-tim tracking of surgical instruments. The 1.7 mm diameter sensor attached to the position and orientation system Magellan (r), Biosense, Inc., Setauket, NY] was deployed through various surgical instruments or used in a hand-held fashion with a malleable shaft probe. We report on our experience using this electromagnetic system in a series of sellar and parasellar skull base lesions. After patient/image registration, the system was consistently accurate to within 2 mm. We have found this system to be particularly advantageous in endoscopie surgery of cystic lesions of the skull base, where access is limited and anatomy may be distorted. In three patients, this device obviated the need for an extensive external surgical approach. Case histories will be presented that illustrate the specific advantages of this miniature system during skull base surgery.