Introduction The fabrication of realistic additively manufactured small vascular models for neurointerventional training remains challenging, as current manufacturing technologies often require a compromise between geometric accuracy and realistic catheter handling. Although several additive manufacturing technologies have been investigated, many fail to reliably reproduce patent lumina in vessels smaller than 2 mm. PolyJet printing enables the fabrication of highly accurate vascular geometries with open lumina; however, it produces comparatively rough inner surfaces, resulting in increased friction and unrealistic catheter handling, thereby limiting the tribological realism of the models.
Methods This study investigated whether surface coatings can improve the tribological performance of PolyJet vascular models while preserving their geometric accuracy. In this exploratory study, eight coating systems were evaluated using surface roughness measurements, cyclic catheter force measurements, short-term stability testing, micro-computed tomography, and clinical validation by experienced interventional neuroradiologists.
Results Several coatings reduced surface roughness and catheter advancement forces compared with uncoated models. However, reduced roughness alone did not fully explain handling performance. Micro-computed tomography revealed substantial differences in coating homogeneity and lumen preservation, whereas force-path analyses demonstrated that homogeneous coatings produced smoother and more uniform force profiles. These objective findings were largely confirmed by the physicians’ subjective assessments. Among the investigated systems, Teflon spray provided the best overall balance between friction reduction, coating homogeneity, ease of application, and clinical acceptance, whereas Aquasure achieved the lowest catheter advancement forces but required a substantially more complex coating procedure.
Discussion The results demonstrate that targeted surface modification can overcome one of the major limitations of PolyJet printed small vascular models by improving tribological realism while preserving their geometric accuracy.
The author(s) declared that financial support was received for this work and/or its publication. The acknowledgements being relevant for this contribution are based on the research project MONTYPIE–Model for Neurointerventional Treatment in Tiny and Peripheral Vessels supported by German Federal Ministry of Research, Technology and Space–BMFTR under the Grant number 03LW0301K.;
