Abstract: A prosthesis includes a radially expanded configuration and a radially compressed configuration. The prosthesis further includes a material layer and a stent. The material layer is generally tubular and has a first diameter when the prosthesis is in the radially expanded configuration. At least a portion of the stent has an unrestrained diameter that is larger than the first diameter of the material layer at a location where the portion of the stent is coupled to the material layer, thereby making the portion of the stent oversized relative to the material layer at the coupling location. The stent may comprise a plurality of stent rings aligned adjacent to each other defining a central passageway, with at least one of the stent rings having an unrestrained diameter larger than the first diameter of the material layer at the coupling location.

Abstract: There is disclosed an apparatus and method for dilating the ligamentum flava or other soft tissue in the human body comprising a radially expandable dilator defining a first expandable tube and an offset tubular guide. A second expandable tube having an integral external guide cam is inserted into the opening of the first expandable tube and aligned with the slit in the first tube effecting radial expansion of the expandable dilator, thereby causing dilation of the ligamentum flava or other tissue. The dilation of the ligamentum flava or other tissue allowing insertion of larger medical leads or surgical instruments into the epidural space.