Abstract: The invention relates to an expandable insert for use as a vessel support in blood vessels, the insert being able to deform plastically from a nonexpanded state to an expanded state by application of a radial force directed from the inside outward, with at least one tubular, essentially cylindrical main body section, whose circumferential surface is formed by a number of annularly meandering rings, the rings in each case forming a one-piece strand of material with a defined strand length. The insert is particularly stiff with respect to externally acting radial forces because a first group of rings is provided whose strand length essentially corresponds to the circumference of the insert in the expanded state, and a second group of rings is provided whose strand length is greater than the circumference of the insert in the expanded state.