Image-guided surgery of the skull base using a novel miniature position 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 a low magnetic field for real-time,tracking of sur gical instruments. The 1.7-mm-diameter sensor attached to the position and orientation, system (Magellan(R), Biosense, Inc., Johnson and Johnson Co.. Baldwin Park, CA) was deployed through various surgical instruments or used in a hand-held fashion with a malleabl shaft probe. We report on our exper ience using this electromagnetic system in a Series of lesions of the sella and clivus. After patient/image registration, the system-was consistently accurate to within 2 mm. We have found this system to be particularly advan tageous in endoscopic surgery of cystic lesions the skull base, where acces s is limited and anatomy may be distorted. In three patients, this device o bviated the need for an extensive external Surgical approach. Case historie s are presented, which illustrate the specific advantages this miniature sy stem provides during skull base surgery.