Treatment device for a blood circulation vessel

1. A treatment device for a blood circulation vessel, comprising:

at least one tubular endoprosthesis, deployable between a retracted state and a dilated state;

a hollow support which extends longitudinally between a proximal end and a distal end, said support being provided, in the vicinity of the distal end, with at least a transverse retention opening; and

at least one releasable threadlike tie for holding the endoprosthesis on the support, the threadlike tie being engaged in the retention opening and actuated from the proximal end of the support to release the endoprosthesis;

wherein the support comprises, over at least a portion of its length, a spring forming the support, the spring having contiguous turns over at least a portion of its length, and the spring delimiting an inner cylindrical wall and/or an outer cylindrical wall of the support; and

wherein two adjacent turns of the spring delimit between them the retention opening, the two adjacent turns belonging to the same spring, the threadlike tie being inserted from the outer cylindrical wall through the two adjacent turns of the spring and the retention opening formed by the two adjacent turns of the spring.

2. The treatment device according to claim 1 , wherein the support comprises at least a sleeve which is more rigid axially than the spring, the sleeve surrounding the spring opposite the retention opening.

3. The treatment device according to claim 2 , wherein the sleeve delimits a transverse opening for the passage of the threadlike tie, the passage opening extending opposite the retention opening.

4. The treatment device according to claim 3 , wherein at least one of the two adjacent turns extends opposite the passage opening so as to avoid contact of the threadlike tie with the contour of the passage opening when the threadlike tie is under tension, and

wherein the threadlike tie is guided by the turns to the passage opening.

5. The treatment device according to claim 3 , wherein the sleeve extends longitudinally between a distal end and a proximal end, at least one of the distal end and the proximal end being engaged with the contiguous turns of the spring to immobilise the sleeve relative to the spring.

6. The treatment device according to claim 4 , wherein the sleeve extends longitudinally between a distal end and a proximal end, at least one of the distal end and the proximal end being engaged with the contiguous turns of the spring to immobilise the sleeve relative to the spring.

7. The treatment device according to claim 1 , comprising a guide tip for guiding the distal end of the support in the blood circulation vessel, the guide tip being fixed on the distal end of the support.

8. The treatment device according to claim 7 , wherein the guide tip is threaded on the spring of the support by engagement with the turns of the spring.

9. The treatment device according to claim 8 , in which the guide tip comprises a distal head and a proximal shank, the proximal shank forming a spiral suitable for threading onto the spring.

10. The treatment device according to claim 9 , wherein the guide tip comprises a flexible proximal skirt.

11. The treatment device according to claim 8 , in which the guide tip comprises a flexible proximal skirt.

12. A system for placing an endoprosthesis in a blood circulation vessel, the system comprising:

a device according to claim 1 ; and

a sheath for inserting the device into the blood circulation vessel, the sheath surrounding the support and the endoprosthesis and comprising a capsule for placing the endoprosthesis which contains the endoprosthesis, the sheath being moveable axially along the support towards the proximal end to release the endoprosthesis from the sheath.

13. The placement system according to claim 12 , wherein the sheath comprises, over at least a portion of its length, a tubular spring with contiguous turns.