| abstract |
Partially encapsulated stents are made using gaps cut into ePTFE covering material. Ring stents are placed over an inner ePTFE tube (e.g., supported on a mandrel) and are covered by a “lacey” graft sleeve, which is constructed by cutting apertures into an ePTFE tube so that a series of circumferential and longitudinal strips is created. This “lacey” sleeve is then laminated to the inner ePTFE tube to capture the stents. By selecting the size and position of the apertures in the ePTFE covering, it is possible to leave critical parts of the stent unencapsulated to facilitate flexibility and expansion. Alternatively, the gaps can consist of slits cut into the ePTFE covering material. These slits can be cut in any direction including longitudinally, radially, or diagonally. In addition, the slits can be spaced at varying intervals around the covering material to maximize flexibility and expandability. Although a single stent can be used, these approaches lend themselves to use of a plurality of individual ring stents spaced apart along the inner ePTFE tube. |