Biodegradable polymeric occluder for closure of atrial septal defect with interventional treatment of cardiovascular disease

The next-generation closure device for interventional treatment of congenital heart disease is regarded to be biodegradable, yet the corresponding biomaterial technique is still challenging. Herein, we report the first fully biodegradable atrial septal defect (ASD) occluder finally coming into clinical use, which is made of biodegradable poly(l-lactic acid) (PLLA). We characterized the physico-chemical properties of PLLA fibers as well as the raw polymer and the operability of the as-fabricated occluders. Cell behaviors on material were observed, and in vivo fiber degradation and inflammatory responses were examined. ASD models in piglets were created, and 44 PLLA ASD occluders were implanted via catheter successfully. After 36 months, the PLLA ASD occluders almost degraded without any complications. The mechanical properties and thickness between newborn and normal atrial septum showed no significant difference. We further accomplished the first clinical implantation of the PLLA ASD occluder in a four-year boy, and the two-year follow-up up to date preliminarily indicated safety and feasibility of such new-generation fully biodegradable occluder made of synthetic polymers.