Skin landmarks as ideal entry points for ventricular drainage, a radiological study

Area of Science:

• Neurosurgery
• Anatomy
• Medical Imaging

Background:

• Ventricular drainage is a common yet complex neurosurgical procedure.
• Neurosurgical trainees face challenges in accurately catheterizing brain ventricles.
• Identifying reliable skin landmarks is crucial for safe and effective ventricular access.

Purpose of the Study:

• To define accurate skin landmarks for ideal entry points (IEPs) for ventricular catheterization.
• To establish precise anatomical references for frontal and parieto-occipital approaches.
• To aid neurosurgical trainees in performing ventricular drainage procedures.

Main Methods:

• Utilized brain MRI data from 30 subjects.
• Simulated ideal lateral ventricle catheterization trajectories.
• Localized skin surface IEPs using anterior and posterior approaches.
• Measured distances from IEPs to identifiable skin landmarks.

Main Results:

• Frontal IEP: 116.8 mm behind nasion, 39.7 mm lateral to midline.
• Parieto-occipital IEP: 62.9 mm above tragus, 53.1 mm behind tragus.
• Estimated ideal catheter lengths: 68.4 mm (frontal), 48.3 mm (parieto-occipital).

Conclusions:

• Defined specific measurements for frontal (11 cm above nasion, 4 cm lateral) and parieto-occipital (5.5 cm behind, 6 cm above tragus) IEPs.
• These landmarks offer practical guidance for orthogonal insertion during ventricular drainage.
• Findings provide valuable, updated references compared to classical descriptions like Kocher's and Keen's points.