Intraoperative landmarking of vascular anatomy by integration of duplex and Doppler ultrasonography in image-guided surgery. Technical note.

BACKGROUND: The integration of ultrasound technology into neuronavigation systems has recently been the subject of reports by several groups. This article describes our preliminary findings with regard to the integration of data derived from intraoperative duplex (color mode) and Doppler ultrasonography into a neuronavigational data set. It was the aim of the study to investigate (1) whether the intraoperative landmarking of vessels that are outlined with ultrasound technology is possible and (2) whether such a technique might be of clinical interest for neurosurgical interventions.
METHODS: The video image of an ultrasound plane (Toshiba, Powervision 6000 SSA-370A, Tokyo, Japan) was integrated into our neuronavigation system (VectorVision2, BrainLab, Heimstetten, Germany). For calibration of the ultrasound plane, an instrument adapter was fixed to the ultrasound probe and then calibrated using a special, predefined calibration phantom.
RESULTS: Accordingly, the system supported a combination of the ultrasound plane functionality with the preoperatively acquired neuronavigational data. The duplex and Doppler mode of the ultrasound system displayed the intraoperative vascular anatomy. Once a vessel was outlined during surgery, it could be landmarked by touching the navigation screen. These landmarks were integrated automatically into the neuronavigational data set and could be used to provide intraoperative image updates of the vascular anatomy. This technique was successful in 45 of 47 (95.7%) surgical interventions.
CONCLUSIONS: Both image-guided ultrasound and duplex-guided integration of vascular anatomy into the neuronavigational data set are technically possible. In the future, this technology may provide useful intraoperative information during surgery of complex cerebral pathologies.