Bioresorbable flow-diverters for cerebral aneurysms: a systematic review

BACKGROUND: Bioresorbable flow diverters (BRFDs) are emerging as next-generation alternatives to permanent metallic stents for intracranial aneurysm flow diversion. These devices aim to provide temporary flow diversion that scaffolds aneurysm healing and then dissolves, potentially reducing chronic foreign-body risks. METHODS: We performed a systematic review (PRISMA methodology) updated to August 2025 to assess BRFD technology and performance. Seventeen studies (2013–2025) met inclusion criteria, describing 27 prototype BRFDs. RESULTS: Devices varied widely in material and design. Many were fully polymeric (typically poly–L-lactic acid or polycaprolactone) or used biodegradable metals (FeMnN), often in polymer–metal hybrid configurations. Approximately 30% were deliverable via standard microcatheters, while about 30% required balloon expansion for wall apposition. In vivo aneurysm models, showed that 61% of BRFDs induced ≥ 80% aneurysm sac occlusion and 33% achieved complete occlusion by final follow-up. These occlusions typically appeared by 3–6 months post-implantation. No parent or jailed branch vessel occlusions were reported. About half of devices fully degraded by study end, and even after polymer or magnesium resorption any integrated radiopaque markers remained in place; importantly, no significant chronic inflammation or vessel stenosis was observed post-resorption. CONCLUSION: No BRFD has yet entered clinical practice. Conclusions regarding efficacy, safety, and long-term durability remain theoretical, and that the persistence of aneurysm occlusion after complete scaffold resorption has not yet been established.