A neuronavigation-based method for locating the superficial temporal artery during extra-intracranial bypass surgery

Abstract

The superficial temporal artery (STA) is frequently used as donor vessel in extracranial to intracranial bypass surgery. Current techniques typically rely on a Doppler vascular probe to identify the STA trajectory prior to the skin incision; however, this step can be time consuming and difficult when the arterial course is tortuous. We tested an alternative neuronavigation-based technique for locating the STA. In this method, preoperative magnetic resonance angiography (MRA) or computed tomography angiography (CTA) was used to determine STA outlines that were then projected and traced onto the skin. The neuronavigation-based technique was applied to eight STA dissections. The accuracy of this method was evaluated by comparing the navigation-based STA course with the doppler-based one and the actual STA course intraoperatively. STA trajectory was determined before surgery by using three imaging techniques: CTA (3 cases), three-dimensional (3D) contrast-enhanced T1-weighted MRA (4 cases), and/or 3D time-of-flight MRA (5 cases). In all cases, the neuronavigation-based STA position was confirmed with the Doppler vascular probe before skin incision and corresponded to the actual vessel position intraoperatively. As long as the skin is not mobilized during preoperative image acquisition and surgery, this neuronavigation-based approach is a valid method to identify STA course. During the preoperative planning process, the STA trajectory should be analyzed from its origin at the level of the foramen spinosum to avoid mistaking nearby venous structures as the STA.