Skull base surgery using Navigation Microscope Integration system

Objective: The use of intraoperative navigation system in neurosurgery has increased rapidly. The Neuronavigation Microscope Integration (NMI) system consists of a microscope (Zeiss, Germany) with StealthStation (Medotronic, U.S.A.) including light emitting diodes, a dynamic reference frame with light emitting diodes, an optical digitizer with camera array and a computer workstation. We investigated the usefulness of the NMI system for skull base surgery. Patients and Methods: Between April 2003 and August 2010, we used the NMI system in 136 patients undergoing skull base surgery including transsphenoidal surgery at Kagawa University Hospital. Results: Since the navigational informations could be superimposed into the microscope view, we obtained the accurate locations of tumor and normal anatomical structures before skin incision. During the operations, the surgeons did not need to turn away from the surgical field or to use bulky pointer. For the skull base surgery, the navigational informations were not affected by the brain shift during the operations. The deviations of registration assessment were within 2 mm and the real anatomical deviations were within 3 mm. For the transsphenoidal surgery, pituitary tumors could be removed safety without X-ray imaging. Conclusion: Our findings suggest that the NMI system can provide valuable and reliable intraoperative navigational informations in skull base surgery.