Intravascular endoprothesis

Claim 1

A system for treating stenosis or obstruction in a blood vessel or other body lumen, said system comprising: a stent including a flat sheet (1) which may be rolled up into a spiral to a reduced diameter (d) around a catheter (7), the stent having overlapping inner and outer longitudinal sections (9, 4); an expander (6) to expand the stent by unrolling the sheet to a larger diameter (D) when it is positioned in the area of stenosis or obstruction such that there is an overlap of the longitudinal edges (4, 9) of said sheet; radially extending fingers (5)(11) provided on the inner overlapping longitudinal section (4) of the sheet (1) which interfit with corresponding means in the outer overlapping longitudinal section (9) of the sheet for locking the stent in the expanded condition. a removable device (8) to temporarily hold the stent (1) in its state of reduced diameter (d) on the catheter (7), a means to release the removable device (8) so that said expander (6) may expand the stent to the larger diameter (D) said system being characterized by: said sheet having apertures so arranged as to give it a reticulated, lattice-like appearance with undeformable links (2, 10); said removable device (8) consisting of a wire laced through said links (2, 10) of at least the last two layers of the spiral formed sheet (1) rolled upon itself; and said radially extending fingers (5, 11) interfitting through said links (2, 10) in the outer overlapping section (9) of the sheet for locking the stent in the expanded condition.

Claim 4

The system according to any one of the preceding claims characterized by the fact that said radially extending fingers (5, 11) consist of a selected number of raised flaps arranged along the covered longitudinal edge (4) of the cylinder in the expanded state, which point in a radially outward direction to the latter and which extend through the first of the links (2, 10) they encounter in the overlapping sheet (1) when the angioplasty balloon is deflated.

Claim 5

The system according to any one of the preceding claims characterized by the fact that the links of the rolled sheet are diamond shaped (10) with the small axis (a) thereto pointing in the longitudinal direction of the stent.

Claim 6

The system according to any one of claims 1 through 5 characterized by the fact that the links of the rolled sheet are square-shaped (2) and the two parallel sides (3) thereof are oriented in the longitudinal direction of the stent.