Defining biomaterial-driven design principles for bioabsorbable flow diverters: current state and perspectives.

Abstract

Flow diverters (FDs) have revolutionized intracranial aneurysm management, but current permanent metallic devices remain constrained by their bulk and surface properties, which induce chronic inflammation, thrombotic risk, and impaired vessel-wall integration. In this review we address these material-driven design challenges, examining how bioactive bioabsorbable biomaterials can overcome current limitations by balancing scaffold resorption with aneurysm occlusion. Moving beyond the clinical focus of existing literature, we establish a rational design roadmap bridging the gap between bulk material properties and FD architecture. We analyze how synchronized degradation kinetics and neointimal encapsulation govern device functionality, identifying this biological isolation as a necessary safety requirement to ensure resorption occurs only after the scaffold is shielded from the active flow. We analyze the mechanical-biological trade-offs of current platforms, whereby bioabsorbable polymers offer superior flexibility but limited radial support, whereas bioabsorbable metals provide higher mechanical integrity but require precision control over degradation. Hybrid strategies, combining transient and permanent components, emerge as effective solutions to balance mechanical reliability with controlled resorption. Across material classes, sustained flow diversion and vascular healing are primarily dictated by the interplay of scaffold architecture, material composition, and time-dependent surface evolution. Our analysis highlights that converging bulk material selection with advanced interfacial engineering enables the rational design of bioabsorbable FDs that maintain temporary mechanical integrity, while ensuring predictable aneurysm occlusion. These design principles establish a scientific framework for next-generation bioactive neurovascular implants, emphasizing a materials-driven approach to optimize safety and translational potential.