Awake craniotomy for the sensorimotor tumors : combined use of synthesized surface anatomy scanning, stimulation cortical mapping and frameless neuronavigation system

Abstract

Objectives: Functional brain mapping and precise localization are essential for the resection of centrally located tumors. We describe our initial experience with awake craniotomy for sensorimotor tumors in 15 patients using synthesized surface anatomy scanning (SSAS), intraoperative functional brain mapping, and an infrared-based navigation system (INS) without fixation of the patient’s head.
Methods: Craniotomy positioning was planned using the images created by SSAS. Fiducial markers were placed along the skin incision line for intraoperative registration of an INS. The resection of the tumor was performed under local anesthesia using both intraoperative functional brain mapping and an INS. In or near the motor cortex or the descending motor pathway, the extent of the resection was determined by the stimulation induced motor response and the intraoperative neurologic findings.
Results: Appropriately centered craniotomies were obtained in all cases using the presurgical planning images of SSAS. Reliable functional localization was identified with direct cortical and subcortical stimulation. The location of the tumors was detected within 3.5 mm of that predicted by the computation (target registration error). Postoperative computed tomography scans showed grossly total resection of the tumor in 13 of 15 cases and subtotal resection in 2 cases. Although 10 patients had mild to severe neurologic deficits in the immediate postoperative period, there were no permanent deficits.
Conclusions: Sensorimotor tumors can be resected effectively with the combined use of SSAS, stimulation cortical mapping and an INS with clinical acceptable morbidity.