Clinical applications of frameless stereotactic devices in neurotology: preliminary report.

Conventional stereotactic surgery has been utilized primarily for intracranial neuro-surgical procedures. Despite their utility, head-frame systems are restrictive and often inconvenient, thus they have not proved applicable for neurotologic surgery. Recently frameless stereotactic navigational systems have been developed that employ three-dimensional digitizers to transform the coordinates in surgical space to the corresponding image space, without the employment of head frames. This allows the determination of position of a surgical instrument in real time during surgery, and its display on video-projected computed tomography or magnetic resonance imaging scanned images. This preliminary report focuses upon an optoelectric referenced frameless stereo-tactic system, the NeuroStation, as it relates to minimally invasive neurotologic surgery. Clinical applications, limitations, and future directions are discussed, and three representative surgical cases are presented. This device has potential as an adjunctive navigational tool for certain neurotologic procedures.