Background: The concept of a two surgeons with four hands surgical technique in endoscopic skull
base surgery limits constant optical based image-guided navigation. Also, rigid head
fixation hinders endoscopic skull base surgery where frequent minor adjustments are
required.
Objective: The authors investigated the efficacy of frameless, pinless electromagnetic image-guided
navigation in endoscopic skull base surgery.
Design: A prospective study of 48 cases was collected from 2009 to 2012.
Methods: Medtronic Stealth AxiEM was used for frameless, pinless electromagnetic image-guided
navigation. The different skull base pathologies approached with the system were craniopharyngiomas,
esthesioneuroblastomas, suprasellar Rathke pouch cysts, giant pituitary adenomas,
angiofibromas, meningiomas, paranasal malignancies, encephalocoele, and gliomas. Outcome
measures included accuracy, histological yield, extent of tumor resection, and navigation-related
complication rate.
Results: There was no case of nondiagnosis consequent of a registration error and inaccurate
trajectory. All cases yielded histological diagnosis. Gross total tumor removal as
assessed by postoperative magnetic resonance imaging was possible in 34 patients (70.8%).
There were no permanent neurological complications except for increased visual disturbance
in one patient with giant pituitary adenoma ant transient VI palsy in one clival meningioma.
Non-navigation–related complications were CSF leak in four patients (8.3%) and meningitis
in one (2%). There was no operative mortality.
Conclusion: Frameless, pinless electromagnetic image-guided navigation in endoscopic skull base
surgery is proved to be simple, safe, and effective in the initial setup and exposure.
It allows the two surgeons, four hands surgical concept with freedom of head movement
and constant navigation.
