The patients who benefit the most from AMIGO are in whom the distinction between tumor and brain and between different critical brain regions is most difficult. This occurs particularly in patients who have low grade gliomas, because although visible on certain imaging sequences, these tumors are nearly indistinguishable from surrounding brain during surgery even through the operating microscope. Moreover, visually all of the cortex and white matter look the same, and the surgeon can not discern the presence of white matter tracts or important areas during resection. In the AMIGO suite we can tie together preoperative mapping, accomplish intraoperative electrophysiology mapping, and obtain new US, MR, CT and PET images as needed.
Brain Tumor Resection Workflow in AMIGO
Craniotomy. Image guidance is used to perform a minimal craniotomy with optimized exposure of the lesion.
Ultrasound. When the dura is exposed, US is performed prior to making any incisions. US provides a fast initial orientation, including the location of major blood vessels. On left, the surgeon is using the BrainLab navigation system integrated with the BK US, and on the right is US with color doppler mode.
ECS. In a very small subset of cases, after the dura is opened and the cortex is exposed, intracranial electrical stimulation testing (ECS) is performed. ECS uses voltage applied directly to the cortex to map important functional areas. This is valuable in confirming and applying preoperative fMRI findings.
Navigation. Throughout the procedure, the pre-operative multimodal image data is used to navigate.
Navigation. Information is available to the surgeon about location and trajectory of her tools.
Tractography. Visualization of the tumor relative to the arcuate fasciculus white matter tract.
Gross Mass Removal. Gross tumor removal is performed using conventional tools aided by iterative neuro navigation. A cauterizer is shown in the picture.
Gross Mass Removal. Ablation and aspiration of tissue is shown.
Gross Mass Removal. Image guidance makes effective tumor resection possible.
Intraoperative MR. Prior to intraoperative MRI, a temporary closure is performed.
Intraoperative MR. A ceiling mounted high field (3T) MR scanner is then brought into the OR.
Tumor assessment. The tumor is contoured in green on the pre-op MRI image.
Assessment of residual tumor. The residual tumor is contoured in red.
Closure and post operative confirmatory imaging. Once the surgeon is satisfied with the extent of tumor resection, the dura is stitched, skull plate replaced, and skin stitched. Post-operative MR scans are obtained to confirm that there are no intraoperative complications and to set a new baseline. Once conscious, the patient is immediately asked to demonstrate motor control, such as foot movement. This confirms that resection has not affected at-risk areas of the motor cortex.