Abstract: Endoluminal prosthetic devices having fluid-absorbable compositions for repair of vascular tissue defects, such as an aneurysm or dissection, are disclosed herein. A prosthesis for repairing an opening or cavity within a target vessel region configured in accordance herewith includes a tubular body sized to substantially cover the opening or cavity, and having channels formed in a wall thereof. The channels can include a fluid-absorbable composition deposited therein and which is configured to absorb fluid (e.g., blood) and swell within the channels, thereby providing radial expansion of the tubular body in situ.