A Modular Cranial Phantom for External Ventricular Drain Placement Simulation: Design and Evaluation

Simulation-based training is a key component of modern neurosurgical education, providing a repeatable environment for procedural practice. External ventricular drain (EVD) placement is a common emergency procedure performed in the early stages of neurosurgical training. This study presents the design, fabrication, and evaluation of a modular phantom targeting a specific brain subregion, intended to replicate the mechanical and procedural aspects of EVD insertion with improved material efficiency and reusability compared to existing full-brain approaches.

A human cranium model was generated from medical imaging data and 3D-printed in two configurations. Both housed a replaceable polyvinyl alcohol (PVA) hydrogel brain sample containing a ventricular cavity. Mechanical tests compared three hydrogel variants for stability and haptic fidelity during controlled catheter advancement. A user study with seven experienced neurosurgeons provided a preliminary qualitative assessment of realism, ergonomics, and simulation fidelity through questionnaires and semi-structured interviews.

Modified hydrogel designs with enlarged or reinforced ventricles demonstrated greater mechanical stability and higher insertion resistance (∼0.6 N) compared to the standard configuration (∼0.4 N), with force-displacement profiles suggesting more consistent haptic feedback during ventricular entry. Surgeons rated cranial realism highly (visual M = 4.43, tactile M = 4.00), though brain visual realism scored lower (M = 2.71), likely reflecting the absence of meninges and cortical surface detail.

The proposed phantom represents an early-stage platform for EVD simulation, offering reproducibility, low cost, and modularity supporting repeated use and anatomical customization. Further validation with larger and more diverse cohorts is needed to substantiate its educational value.