STENT DEVICE DELIVERY SYSTEM WITH INWARDLY TAPERING STENT BED

• US 20110137396A1
• Filed: 12/01/2010
• Published: 06/09/2011
• Est. Priority Date: 12/03/2009
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Dietrich, Daniel, Gahr, Jeldrik zum, Forster, Markus, Dorn, Jürgen
• Granted Patent: US 9,724,216 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61M 25/0009 Making of catheters or other medical or surgical tubes

Abstract

A stent device delivery system and method of making. The stent device delivery system includes a stent device, an outer sheath overlaying the stent device in a radially compact, delivery configuration of the stent device, and an inner catheter extending axially and radially within a lumen of the stent device. The inner catheter provides a stent bed upon which the stent device is located so that a radially inner surface of the stent device engages a radially outer surface of the stent bed. The stent bed may define an inwardly tapering profile, narrowing in radius from a distal portion of the stent device to a proximal portion of the stent device.

Claims

1. A stent device delivery system, comprising:

a stent device;

an outer sheath overlaying the stent device in a radially compact, delivery configuration of the stent device, the outer sheath retractable from a distal end of the stent device to a proximal end of the stent device to allow for radial expansion of the stent device to a deployed configuration; and

an inner catheter extending axially and radially within a lumen of the stent device and providing a stent bed upon which the stent device is located so that a radially inner surface of the stent device engages a radially outer surface of the stent bed, wherein the stent bed defines an inwardly tapering profile, narrowing in radius from a distal portion of the stent device to a proximal portion of the stent device.

2. The stent device delivery system of claim 1, wherein the stent bed tapers at a gradient, change in outer diameter of the stent bed divided by axial length over which the change in outside diameter occurs in the range of 0.0003 to 0.005.

3. The stent device delivery system of claim 2, wherein the stent bed tapers at a gradient, change in outer diameter of the stent bed divided by axial length over which the change in outside diameter occurs in the range of 0.0006 to 0.0009.

4. The stent device delivery system of claim 1, wherein the inwardly tapering profile is stepwise.

5. The stent device delivery system of claim 1, wherein the stent bed is axially continuous with respect to the stent device.

6. The stent device delivery system of claim 1, wherein the stent bed is formed by a plurality of axially separated portions, such as axially separated band members.

7. The stent device delivery system of claim 6, wherein the band members define a progressively reducing outside diameter of the stent bed in the proximal direction by a stepwise reduction from one band to an adjacent band in the proximal direction.

8. The stent device delivery system of claim 1, wherein the stent bed is made of a compressible material and the stent device is partially embedded in the stent bed in the radial direction.

9. The stent device delivery system of claim 1, wherein the stent bed is made of a tacky material, which provides a radial as well as an axial holding force on the stent device relative to the inner catheter such that during expansion of the stent device, the stent device peels away from the tacky material of the stent bed.

10. The stent device delivery system of claim 1, wherein the stent bed is formed as a layer on the inner catheter.

11. The stent device delivery system of claim 1, further comprising a pull member for putting in endwise tension to retract the outer sheath from the stent device, wherein the outer sheath comprises a distal portion overlaying the stent device, a proximal portion where the outer sheath is attached to the pull member and a transition portion connecting the distal portion and the proximal portion, where the transition portion tapers radially inwardly from the distal portion to the proximal portion.

12. The stent device delivery system of claim 1, wherein the outer sheath comprises an inner layer contacting an outer surface of the stent device, an outer layer and a fold-over portion connecting the inner layer and the outer layer, so that proximal movement of the outer layer relative to the inner layer causes the fold-over portion to move proximally axially relative to the stent device in a rolling manner and thus enables retraction of the outer sheath.

13. The stent device delivery system of claim 12, wherein the outer sheath is formed into a tapered profile with the inner layer tapering radially inwardly from the distal portion to the proximal portion of the stent device and the outer layer tapering radially outwardly from the distal portion to the proximal portion of the stent device.

14. The stent device delivery system of claim 1, wherein a portion of the outer sheath overlaying the stent device is formed having a tapering profile substantially following the tapering profile of the stent bed.

15. The stent device delivery system of claim 1, wherein the outer sheath is made of a cold drawn polymeric material at least along a portion thereof overlaying the stent device.

16. A method of making a stent device delivery system, comprising:

loading a stent device into a sleeve of polymeric material, the sleeve providing an outer sheath of the stent device delivery system that is retractable relative to the stent device to allow the stent device to radially expand to a deployed configuration;

positioning an inner catheter radially and axially within a lumen of the stent device, the inner catheter presenting a stent bed with an inwardly tapering profile for the stent device to be located upon; and

cold drawing the sleeve with the stent device loaded therein to reduce the diameter of the sleeve and to transition the stent device from a radially expanded configuration into a radially reduced delivery configuration, thereby bringing into engagement a radially inner surface of the stent device and a radially outer surface of the stent bed.

17. The method of making a stent device delivery system of claim 16, further comprising folding the sleeve of polymeric material back onto itself to provide the outer sheath with an inner layer, an outer layer and a distal fold-over portion connecting the inner layer and the outer layer, wherein the stent bed tapers radially inwardly in a proximal direction from a larger diameter at a distal portion of the stent device to a smaller diameter at a proximal portion of the stent device.

18. The stent device delivery system of claim 17, wherein the inner layer and the outer layer are laminated together to provide a pullback stent device delivery system.

19. The stent device delivery system of claim 17, wherein the inner layer and the outer layer are left movable relative to one another to provide a rolling stent device delivery system whereby the inner layer and the outer layer are able to move relative to one another to cause the fold-over portion to move relative to the stent device, thereby allowing retraction of the outer sheath from the stent device.

20. The method of making a stent device delivery system of claim 16, further comprising:

positioning a mandrel radially and axially within the sleeve of polymeric material to abut an end of the stent device closest to a large diameter end of the tapering stent bed, wherein the mandrel has a tapering profile that continues the tapering profile in that the mandrel continues to taper radially outwardly in a distal direction, which is the direction from the stent device to the mandrel;

cold drawing the sleeve of polymeric material onto the mandrel, which provides a cold drawn portion overlaying the stent device and a cold drawn extension portion overlaying the mandrel; and

folding back the extension portion over the stent device portion to provide a first, inner layer of the outer sheath and a second, outer layer of the outer sheath.