Transovale trigeminal cistern puncture: modified fluoroscopically guided technique.

A simple, safe, and rapid radiologic technique is described for trigeminal puncture via the foramen ovale. A radiopaque marker is placed 3 cm lateral to the labial commissure. Then, under fluoroscopic guidance, the patient's head is turned until the marker is projected vertically, over the foramen ovale. The needle can be advanced along the anatomically safe line determined by the foramen ovale and the lateral labial puncture site. Needle or patient misalignment is detected readily and can be corrected using fluoroscopic guidance. The technique is learned easily, obviates multiple needle passes, and takes less than 5 min.