Abstract
In brain tumor surgery, navigation is helpful for precise targeting of deeply seated lesions and important structures, and for performing accurate tumor resection. Intraoperative echo-guided surgery through a cranial window has been used for removal of tumors, arteriovenous malformations, and other pathological structures. The echo probe can be applied intermittently through the cranial window to visualize the operating field. Initially, very good images can be obtained, but during the operation the images deteriorate and become difficult to visualize. To obtain clear echo images without interruption of the surgical procedure, we created another small cranial window at the opposite side of the operating field, into which an echo-guiding probe was inserted. We were then able to produce clear images continuously until the end of the operation. The shifting of intradural structures caused by CSF drainage and/or reduction of the tumor mass was detectable in real time. This method also allowed clear evaluation of the relationship between the tumor and blood vessels. We used this method for 16 cases that involved large and deeply located brain tumors, including meningiomas, gliomas and pituitary adenomas, and were able to perform the required surgery safely, easily, and with a high degree of success. This method for continuous echo-guided surgery has already proved to be useful for the safe removal of brain tumors.
