Frameless stereotactic localization in cranial base surgery

Mastery of the three-dimensional anatomic relationships of the cranial base /paranasal sinuses is required to reduce the incidence of iatrogenic surgic al complications, facilitate complete tumor extirpation, and enhance functi onal outcomes. Real-time intraoperative localization technology is one meth od available to assist the cranial base surgeon. We report our institutiona l experience with the StealthStation(TM) treatment guidance platform. Eight y-eight consecutive patients with pathology of the cranial base/paranasal s inuses were operated on with the aid of real-time frameless stereotactic lo calization. Preoperative image datasets were acquired with either CT or MRI scans. Patient demographics, accuracy of the data sets, surgical approache s, pathology, complications, and further applications of this technology ar e presented. Procedures were performed on 47 women and 41 men ranging in ag e from 6 to 85 years, in these 88 procedures, 44 MRI and 44 CT scans with a mean accuracy of 1.57 and 1.23 mm, respectively, were used. Approaches to the cranial base included midface degloving (25), endoscopic (23), craniofa cial (13), maxillectomy (12), rhinotomy without maxillectomy (5), transoral (5), pterional (2), transcondylar (1), and transcervical (2). Indications for surgery included severe inflammatory disease of the paranasal sinuses w ith epidural or subdural abscess, or both (7), cerebrospinal fluid fistula or encephalocele, or both (11), and 40 benign and 30 malignant tumors. Comp lications occurred in 10 of 88 patients (11%). Real-time intraoperative loc alization can be applied to cranial base surgery in a variety of scenarios. The instantaneous transfer of imaging data to the surgical field is useful in localizing pathology, enhancing operative safety, and reducing morbidit y, thereby improving outcomes. This technology will certainly play an integ ral role in minimizing complications and improving surgical outcomes as cra nial base surgery moves into the next millennium.