US Patent 9456823 Embolic devices

Described herein are apparatus, compositions, systems and associated methods to occlude structures and malformations of the vasculature with radiopaque hydrogel filaments with delayed controlled rates of expansion. Further described is a device for implantation in an animal comprising a difunctional, low molecular weight ethylenically unsaturated shapeable macromer; an ethylenically unsaturated monomer; and a radiopaque element, wherein said device contains no support members. Methods of forming such devices are also disclosed.