Intraoperative Ventriculostomy Using K Point in Surgical Management of Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Intraoperative ventriculostomy in the surgical management of aneurysmal subarachnoid hemorrhage (SAH) is frequently performed to reduce increased intracranial pressure. The previously suggested ventriculostomy points have some limitations because the dura mater must be opened to be accessed and it is difficult to measure the exact entry point in patients with brain edema. We propose a new intraoperative ventriculostomy point (K point) for use in the surgical management of aneurysmal SAH patient with severe brain edema.

METHODS: We performed intraoperative ventriculostomy using the K point on 155 patients with aneurysmal SAH between January 2012 and August 2016. Before opening the dura mater following standard pterional craniotomy, we inserted the ventricular catheter through a small dural incision perpendicular to the middle frontal gyrus toward the ipsilateral medial epicanthus. We simulated the catheter trajectory using a commercial navigation system on 2 patients with brain tumor.

RESULTS: Ventriculostomy related hemorrhage occurred in 12 patients (7.7%), but there were no large hemorrhages causing neurologic deterioration or requiring evacuation. No language impairment was observed in these patients. Analysis using the navigation system revealed that the trajectory of K point ventriculostomy avoided critical periventricular brain structures and passed through the space between the genu of the corpus callosum and head of the caudate nucleus.

CONCLUSIONS: K point ventriculostomy allows for easy access to a target point and protects the brain during opening of the dura mater and drilling of the sphenoid bone.