Expandable sealing means for endoluminal devices have been developed for controlled activation. The devices have the benefits of a low profile mechanism (for both self-expanding and balloon-expanding prostheses), contained, not open, release of the material, active conformation to the &ldquoleak sites&rdquo such that leakage areas are filled without disrupting the physical and functional integrity of the prosthesis, and on-demand, controlled activation, that may not be pressure activated.
