Intraoperative neuronavigation system without rigid pin fixation

Object: Integration of neuronavigation into brain tumor surgery can improve the accuracy and precision of resection, but most neuronavigation systems require rigid pin fixation of the patient's head throughout the operation. We describe use of a noninvasive skull reference tool, which can replace rigid pin fixation in awake craniotomy and pediatric surgery, when standard pin fixation cannot be used. Methods and Results: The skull reference tool (BrainLAB, Munich, Germany) is directly attached to the outer skull with a small self-tapping screw. Virtual scanning of the surface of the face and head achieves patient registration in seconds without requiring the use of fiducial markers or head fixation. This procedure improves patient comfort, cooperativeness, and compliance, resulting in better operating procedures. This skull reference tool is available for children younger than 3 years of age, in whom pin fixing is dangerous. Twelve patients underwent awake surgery and four pediatric patients younger than 3 years old underwent five procedures using this skull reference tool in our hospital between January 2005 and December 2008. The method of utilizing this skull reference tool was easy and sufficiently accurate in these patients. Conclusion: The use of this skull reference tool provides an accurate and comfortable method of frameless navigation in patients undergoing awake craniotomy and pediatric patients.