Intraoperative ventricular puncture during supraorbital craniotomy via an eyebrow incision. Technical note

The authors determined the landmarks and coordinates for intraoperative ventricular puncture directly from the supraorbital craniotomy opening via an eyebrow incision. Fifty magnetic resonance (MR) imaging studies were obtained from patients with no pathological cerebral characteristics or ventricular distortion. The cerebral entry point of the ventriculostomy was located directly under the key bur hole (just behind the zygomatic process of the frontal bone) at the base of the frontal lobe because it represents a stable, reliable point that can be used as the bur hole during supraorbital craniotomy via an eyebrow incision. From this point, the coordinates for lateral ventricular puncture were determined using MR imaging studies and neuronavigational software. The cerebral entry point of the ventriculostomy was situated directly under the key bur hole at the base of the frontal lobe. The catheter was directed at a 45 degrees angle to the midline and a 20 degrees angle up from an imaginary line parallel to the orbitomeatal line. The catheter will usually be inserted into the ventricle at a point 5 cm deep to the cortex and may be inserted as deep as 6.5 cm. Using this technique, the frontal horn of the lateral ventricle can be easily tapped. The landmark required for this technique is readily available in all patients.