A medical device includes a multi-layered structure comprising an inner layer disposed within an outer layer, wherein each of the inner and outer layers has respective inner and outer surfaces. The multi-layered structure further comprises at least offset located between the inner and outer layers or formed in the inner and/or outer layers to define at least one gap therebetween such that a majority of the outer surface of the inner layer is spaced apart from the inner surface of the outer layer. The multi-layered structure is configured to be deployed within a lumen such that at least a portion of the outer layer is configured to engage the lumen and the at least one gap is configured to promote thrombosis between the inner and outer layers.
