Introduction of Universal WON-Point for Posterior Cranial Fossa Puncture in Monitoring Infratentorial Intracranial...

Area of Science:

• Neurosurgery
• Neurology
• Anatomy

Background:

• Intracranial pressure (ICP) monitoring is crucial for managing brain injuries.
• Current methods for monitoring ICP in the posterior cranial fossa are limited and lack standardization.
• A novel reference point is needed for accurate infratentorial ICP (iICP) monitoring.

Purpose of the Study:

• To define and validate the WON point as a novel anatomic landmark.
• To enable minimally invasive and standardized iICP probe placement.
• To assess the safety and feasibility of the WON point for iICP monitoring.

Main Methods:

• The WON point was defined relative to the external auditory canal and contralateral mastoid tip.
• Feasibility was assessed in neuronavigated surgery patients and cadaveric studies.
• ICP sensors were implanted in body donors to evaluate distances to venous sinuses and critical structures.
• The WON point was utilized for iICP monitoring in patients with ischemic cerebellar infarction.

Main Results:

• The WON point demonstrated safety and effectiveness, with no observed damage to critical structures like the brainstem.
• Median distances to venous sinuses (transverse, occipital, sigmoid) were established.
• A safe median distance of 3.28 cm to the nearest venous structure was confirmed.

Conclusions:

• The WON point serves as a novel, universal landmark for safe and reliable iICP monitoring.
• Minimally invasive sensor placement is facilitated by this standardized approach.
• Further clinical validation is recommended to integrate the WON point into routine neurosurgical practice.