An elongated support dimensioned and configured for implantation in a blood vessel. The support has two axially spaced apart portions, which may be in the form of an expandable crown or a similar structure. At least one linking member connects the two portions to one another. A valve membrane is supported between the axially spaced apart portions. The valve membrane is adapted and configured for movement between a first position in which blood flow through the support is permitted and a second position in which blood flow through the support is inhibited.