The Impact of Ventricular Catheter Biomaterial Selection: Mechanical Properties and Protein Adsorption.

Abstract

Ventricular catheter (VC) obstruction remains one of the most common causes of cerebrospinal fluid (CSF) shunt failure in hydrocephalus patients. Material properties of VCs are hypothesized to contribute to failure, yet few studies have systematically compared alternative biomaterials using a consistent VC design and manufacturing process. This study aimed to evaluate the feasibility of producing VCs from a range of commercially available elastomeric biomaterials using a rapid prototyping process and subjecting VCs to testing aimed at validating mechanical and surface properties relative to a commercial VC. A lost-wax casting technique was employed to fabricate VCs from five biomaterials: three silicones of select hardness ratings, polyisoprene, and polyurethane. Biomaterial performance was assessed via standardized tests, including tear strength, raw material hardness, contact angle, fluid resistance, protein adsorption, and surface morphology. A benchtop system improved with oscillatory flow was used to assess protein adsorption. All fabricated VCs had similar dimensions to the commercial VC. Polyisoprene demonstrated the highest tear strength, while polyurethane exhibited the smoothest surface. Despite assessing VCs with different hardnesses, surface textures, and surface energy, there was no significant difference in protein adsorption. This work represents an effort that combines rapid lab-based manufacturing, VC material testing, and VC biological testing under clinically relevant flow direction and volume. In this way, this work offers new insight into new VC materials, a shift in prototype and testing protocols for VCs used in hydrocephalus, and suggests the need for environmental control and exposure in future testing to improve shunt longevity.