Intraoperative three-dimensional visualization in microvascular decompression

Abstract

The authors systematically analyzed 3D visualization of neurovascular compression (NVC) syndromes in the operating room (OR) during microvascular decompression (MVD). A total of 50 patients (26 women and 24 men) with trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GN) were examined and underwent MVD. Preoperative imaging of the neurovascular structures was performed using constructive interference in the steady state magnetic resonance (CISS MR) imaging, which consisted of 2D image slices. The 3D visualization of the neurovascular anatomy is generated after segmentaion of the CISS MR imaging in combination with direct volume rendering (DVR). The 3D representations were stored on a personal computer (PC) that was mounted on a mobile unit and transferred to the OR. During surgery, 3D visualization was applied by the surgeon with remotely controlled plasma-sterilized devices such as a wireless mouse and keyboard. The position of the 3D visualized neurovascular structures at the PC monitor was determined according to the intraoperative findings observed through the operating microscope. The system was stable during all neurosurgical procedures, and there were no operative or technical complications. Interactive adjustment of the 3D visualization guided by the view through the microscope permitted observation of the neurovascular relationships at the brainstem. Vessels covered by the cranial nerves could be noninvasively viewed by intraoperative 3D visualization. Postoperatively, the patients with TN and GN experienced pain relief, and the patients with HFS attained resolution of their facial tics. Vascular compression of nerves was explored in all 50 patients during MVD. Intraoperative 3D visualization delineated the compressing vessels and respective cranial nerves in 49 (98%) of 50 patients. Interactive 3D visualization by DVR of high-resolution MR imaging data offered the opportunity for noninvasive virtual exploration of the neurovascular structures during surgery. An extended global survey of the neurovascular relationships was provided during MVD in each case. The presented method proved to be extremely advantageous for optimizing microneurosurgical procedures, supporting superior safety and improving the operative results when compared with the conventional strategy. This modality proved to be a very valuable teaching instrument and ensured the improvement of neurosurgical quality.