Stent assembly and method of use

• US 5,833,694 A
• Filed: 05/16/1997
• Issued: 11/10/1998
• Est. Priority Date: 05/25/1995
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Poncet, Philippe
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US08/857,983
• Time in Patent Office: 543 Days
• Field of Search: 606/108, 606/198, 606/191, 606/141, 604/62
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/9517 handle assemblies therefor
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2002/826 more than one stent being applied sequentially

Abstract

The invention is a method for deploying a stent including the steps of providing a sheath containing a plurality of stents; locating the distal end of the sheath at a treatment site in a passage; and moving the sheath and a first stent relative to each other a distance sufficient to expose the first stent to the passage by actuating a stent deployment mechanism disposed at the proximal end of the sheath, the distance being determined solely by the structure of the stent deployment mechanism. The invention also includes a stent assembly comprising a sheath; a stent stop within the sheath at the distal end of the sheath; a stent disposed against the stent stop; an actuator; and an actuator limit stop. Also included within the invention is a stent loading mechanism.

Claims

1. A stent assembly for dispensing stents, the stent assembly comprising:

a) an elongated sheath having a proximal end and a distal end, the distal end being sized to receive at least one stent;

b) a stent stop movably disposed within the sheath at the distal end;

c) an actuator disposed at the proximal end of the sheath and connected to the stent stop for moving the stent stop at the distal end, the actuator including a spacer chamber and a plurality of spacers disposed in the chambers, each spacer defining a distance of movement of the stents at the distal end for each actuation of the actuator such that the stents are dispensed individually from the distal end of the sheath; and

d) an actuator limit stop disposed to limit the motion of a portion of the actuator toward the distal end, such that only one stent is dispensed from the distal end of the sheath upon each actuation of the actuator.

2. The stent assembly of claim 1, comprising a first stent disposed against the stent stop and a second stent disposed against the first stent.

3. The stent assembly of claim 1, wherein the stents are self-expanding between a compressed shape and an expanded shape, the stent having a length in the compressed shape which is at least about 80% of the stent length in the expanded shape.

4. The stent assembly of claim 1, wherein the stents are comprised of a superelastic material.

5. The stent assembly of claim 1, wherein each actuation of the actuator provides (i) simultaneous one-directional movement of the stent stop, the stents, and one spacer toward the distal end of the sheath, (ii) substantially equidistant movement of the stent stop, the stents, and one spacer within the sheath, and (iii) individual stent dispensing from the distal end of the sheath.

6. The stent assembly of claim 5, wherein each actuation of the actuator moves one spacer from the spacer chamber and toward the distal end of the sheath, such that only one stent is dispensed from the distal end.

7. The stent stop of claim 1, wherein the stent stop remains adjacent to a side of a stent that is positioned farthest from the distal end of the sheath during repeated actuation of the actuator.

8. A method for deploying stents individually in a body passage, the method comprising the steps of:

a) providing a stent assembly comprising;

i) a sheath including a proximal portion having a proximal end and a distal portion having a distal end, the proximal portion defining a bore having a diameter and the distal end defining an enlarged chamber

     1) having a diameter greater than the diameter of the bore, and

     2) sized to receive a plurality of self-expanding stents each in a compressed state within the enlarged chamber;

ii) a movable elongated member extending between the proximal portion and the distal portion within the bore; and

iii) an actuator connected to the elongated member for moving the stents within the enlarged chamber; and

iv) a limit stop at the proximal end of the sheath;

b) loading into the enlarged chamber of the sheath through the distal end at least a first compressed, self-expanding stent and a second compressed, self-expanding stent disposed against the first stent;

c) introducing the sheath into the body passage and locating the distal end at a treatment site; and

d) moving the actuator a predetermined distance defined by the limit stop to move the sheath and the elongated member a pre-determined distance relative to each other, and to move the elongated member, the first stent and the second stent simultaneously only in a direction toward the distal end of the sheath, so as to dispense only one stent from the enlarged chamber at the treatment site, thereby causing the dispensed stent to self-expand.

9. The method of claim 8, wherein the stents are comprised of a superelastic material, and the stents are superelastically deformed when disposed in the enlarged chamber of the sheath.

10. The method of claim 8, wherein the stents have a length when compressed in the enlarged chamber of the sheath which is at least about 80% of the stent length in the expanded state.

11. The method of claim 8, wherein the stents have a length in the expanded state which is greater than the diameter of the body passage at the treatment site such that the stents exert a generally constant pressure on the body passage.

12. A method of loading stents in a stent assembly, the stent assembly including a sheath having a proximal portion and an enlarged distal end defining a chamber sized to receive a plurality of stents, the method comprising the steps of:

a) providing a loading means sized to removably couple with the enlarged distal end of the sheath;

b) providing a plurality of stents, each having a compressed shape and an expanded shape;

c) loading the stents into the loading means in the compressed shape;

d) coupling the loading means with the distal end of the sheath;

e) simultaneously moving the stents from the loading means to the chamber of the sheath such that the stents are in the compressed shape in the chamber; and

f) decoupling the loading means from the distal end of the sheath.

13. The method of claim 12, wherein the stents are comprised of a superelastic material, and the stents are superelastically compressed in the compressed shape.

14. The method of claim 13, wherein the stents have a length in the compressed shape which is at least about 80% of the stent length in the expanded shape.

15. The method of claim 12, wherein the stents are adjacent to each other in the chamber.

16. The method of claim 12, wherein the stents are separated from each other by shoulders in the chamber.