gms | German Medical Science

Objective: Additional aid to orientation during complex resections and deep seated pathologies of the skull base contributes to a more radical and safer procedure, especially for narrow approaches. Neuronavigation is a well established tool that allows for precise targeting of the pathology while sensitive structures can be preserved. However, due to the limitations of the technical devices an uncertainty remains concerning the actual intraoperative accuracy. Intraoperative imaging is suitable to compensate for these limitations. Although intraoperative CT or MR imaging is possible, these techniques go along with a high operative effort. The 3D imaging capability of modern C-arms provide a promising alternative which is demonstrated below.

Methods: Prior to surgery a 3D CT-volume is performed, including an additional CT-angiography in selected cases. The software of the neuronavigation system is used for a segmentation of target and sensitive structures as well as for the planning of the operative approach. Matching tools can be used to integrate MRI images. During the surgical procedure intermittent intraoperative scans are performed with a Siemens ISO-C 3D C-arm. The scanned image-volume is fused with the preoperative image data to allow for a direct control of the resection progress. Segmented information can easily be further used by this technique.

Results: 3D-C-arm imaging provides three-dimensional imaging of bony structures of the skull base with CT-like quality. The combination with preoperative CT and MRI-image-volumes and additional information provided by a neuronavigation system allows for superior resection control and safety in comparison to each of the technical devices alone. Image acquisition takes 2 minutes only and can be performed with minimal additional effort within the sterile area.

Conclusions: 3D-C-arm imaging allows for time and cost-effective three-dimensional intraoperative imaging of bony structures of the skull base in CT-like quality. This technical tool provides a precise method to monitor the resection progress and can be used to update the image data for neuronavigated procedures. Thus, 3D-C-arm imaging contributes to avoidance of complications and optimizes the resection result in the complex field of skull base surgery.