gms | German Medical Science

Objective: Neuronavigation has been a mainstay of cranial surgery since the mid-nineties of the last century. A drawback of conventional neuronavigation systems is the necessity of focusing on three 2D images (in the sagittal, axial and coronal planes), to determine the real spatial position in the OP field. A solution to integrate the spatial information in one single image is the application of 3D projection. Until recently this required the use of 3D-glasses, which was unpractical and cumbersome. We applied a neuronavigation-linked holographic glassless 3D monitor for intraoperative image-guidance in the sellar region, and present our experience as a proof of principle

Method: We have tested the image-guidance linked 3D monitor in 10 patients with sellar and suprasellar pituitary tumors. The operative planning was conducted as usual with a Colibri navigation system (BrainLab, Germany) using cranial CT and MR imaging. The image data sets were then processed by the Clariti 3D navigation system (Setred, Sweden) to produce a 3D rendering of the images. The two systems were then linked and synchronised. The operations were conducted as usual through a transphenoidal approach utilizing a pituitary endoscope (Storz, Germany).

Results: We found the 3D navigation intuitive, simple and safe to use. The rendered images were accurate and the accuracy of image-guidance was high. The rendered 3D images matched the endoscopic video images exactly. Furthermore the surgeons were able to visualise structures beneath the current OP field, especially sensitive anatomic structures such as the carotid artery, which could also be segmented separately. The spatial information gained was far superior to conventional neuronavigation. Our surgeons reported a steep learning curve and mastered the new navigation system intuitively. The main disadvantages we found were the additional planning and effort needed to render the images in the 3D system.

Conclusions: We conclude that a 3D monitor is a beneficial supplement to conventional 2D navigation, especially with regards to spatial orientation. This could be particularly advantageous in cases with tumor recurrence, where ‘normal’ anatomy is altered by scarring from previous operations. With further development of the 3D-system, it could eventually replace conventional triplane navigation due to its intuitive ease of use. 3D rendering could additionally be helpful in the operative planning procedure and as an operation simulation tool.