Catheter and system for introducing an intraluminal endoprosthesis

1. A catheter, comprising:

a) an internal tube;

b) an external tube which at least sectionally encloses the internal tube;

c) a balloon having an endoprosthesis section having a proximal end and a distal end which can position an intraluminal endoprosthesis, the balloon being connected to the external tube; and

d) a first set of metal rings positioned proximate to the endoprosthesis proximal end and a second set of metal rings positioned proximate to the endoprosthesis distal end, the first and second sets of rings crimped onto the internal tube, at least two rings in each set having different lengths from each other, the first and second sets of rings being provided at predetermined spacings so as to provide a rigidity transition at the proximal and distal ends, respectively, of the endoprosthesis section.

2. The catheter of claim 1 , wherein the first and second sets of metal rings are made of one or more metals from the group consisting of platinum and iridium.

3. The catheter of claim 1 , wherein the number of metal rings in each set of rings is from 2 to 5, the rings having either a length of approximately from 0.1 mm to 1 mm or a spacing of approximately from 0.1 mm to 1 mm, or both.

4. The catheter of claim 1 wherein the metal rings are made of a material visible upon x-ray irradiation.

5. The catheter of claim 1 wherein there are at least three rings in the first set or the second set or both, and wherein a distance between the first ring and the second ring is different from a distance between the second ring and the third ring.

6. A system for introducing an intraluminal endoprosthesis, preferably a stent, into a body cavity, comprising:

a) an intraluminal endoprosthesis, and

b) a catheter comprising:

i) an internal tube;

ii) an external tube which at least sectionally encloses the internal tube;

iii) a balloon having an endoprosthesis section which can position an intraluminal endoprosthesis, the balloon being connected to the external tube; and

iv) a first set of metal rings positioned proximate to the endoprosthesis proximal end and a second set of metal rings positioned proximate to the endoprosthesis distal end, the first and second sets of rings crimped onto the internal tube, at least two rings in each set having different lengths from each other, the first and second sets of rings being provided at predetermined spacings so as to provide a rigidity transition at the proximal and distal ends, respectively, of the endoprosthesis section,

wherein the intraluminal endoprosthesis is located in the endoprosthesis section on the balloon, the endoprosthesis being crimped externally onto the endoprosthesis section of the balloon.

7. The system of claim 6 , wherein the endoprosthesis further comprises an x-ray marker disposed on at least one of the ends of the endoprosthesis in the longitudinal direction.

8. The system of claim 6 , wherein the endoprosthesis further comprises a pharmaceutically active substance.

9. The system of claim 6 , wherein the first and second sets of metal rings are made of one or more metals from the group consisting of platinum and iridium.

10. The system of claim 6 , wherein the number of metal rings in each set of rings is from 2 to 5, the rings having either a length of approximately from 0.1 mm to 1 mm or a spacing of approximately from 0.1 mm to 1 mm, or both.

11. The system of claim 6 , wherein the endoprosthesis comprises a degradable material.

12. The system of claim 6 wherein the metal rings are made of a material visible upon x-ray irradiation.