Neuronavigation in Endonasal Pituitary and Skull Base Surgery Using an Auto-Registration Mask without Head Fixation: An Assessment of Accuracy and Practicality

Introduction: Intraoperative navigation is an important tool used during endonasal surgery that typically requires rigid head fixation. Herein, we describe a navigational technique using an auto-registration mask without head fixation.

Methods: Prospective evaluation of a surface auto-registration mask used without rigid head fixation in 12 consecutive endonasal skull base procedures was performed with patients positioned in a horseshoe head holder. We assessed the accuracy by recording the surface registration error (SRE) and target registration error (TRE). The time required for installation and the occurrence of system failure were noted. The system's accuracy was validated using a deep target viewed with the endoscope.

Results: We evaluated this technique in 12 consecutive endonasal cases performed by a neurosurgeon and ENT team. The surgeries treated macroadenomas (9), a chordoma (1), a craniopharyngioma (1), and a sinonasal melanoma (1). Median time required for registration and accuracy verification was 84 seconds (interval, 64 to 129 seconds). The mask stayed on the patient throughout the procedure. The mean SRE was 0.8 mm (interval, 0.6 to 0.9). The mean TRE was 0.9 ± 0.7 mm and 1.0 ± 0.8 mm, measured respectively at the beginning and end of each case. In every case, the system was judged accurate by the surgeons using the sphenoid keel or an intrasphenoidal bony septation as a deep target for internal validation. No system failure occurred.

Conclusion: A facial surface auto-registration mask maintained in place throughout surgery without rigid head fixation allows excellent operational accuracy in endonasal pituitary and skull base surgery. This navigational technique is practical, reliable, and noninvasive.