Advanced image-guided skull base surgery

BACKGROUND Tumors of the skull base frequently encase or extend into normal neural and vascular structures. Preoperative planning and intraoperative identificati on of anatomic landmarks is especially important in complex tumors since it helps avoid or minimize surgical morbidity, METHODS By creating a surgical plan the image guidance software offers help in the establishment of a surgical approach. During surgery, the neuronavigation s ystem displays the location of anatomic landmarks of the skull base regardl ess of any erosion or displacement, RESULTS A series of 10 patients with complex tumors in various skull base locations is reported. Osseous structures are easily identified using the CT-based i mage guidance since these landmarks do not shift due to CSF loss. Image fus ion of CT and MRI data gives additional information on the displacement of soft tissue structures. Image fusion in a substraction mode is helpful when a tumor has invaded bony structures or when the encasement of major vessel s has to be visualized. CONCLUSION The preoperative data preparation (planning of the approach, image fusion) plays a vital role in modern neuronavigation and contributes useful informa tion during surgery for complex skull base tumors. Such advanced neuronavig ation increases the efficacy and safety of intraoperative maneuvers. Eroded and distorted anatomic landmarks are not subject to a significant amount o f intraoperative shift throughout the surgical procedure. (C) 2000 by Elsev ier Science Inc.