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.