EXPANDABLE SHEATH

• US 20160296730A1
• Filed: 10/09/2015
• Published: 10/13/2016
• Est. Priority Date: 04/10/2015
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: Bulman, Erik, Geiser, Timothy A., Bian, Baigui, White, Richard D., Gowdar, Alpana K., Zhou, Pu, Valdez, Michael G., Zhu, Yidong M., Tran, Sonny, Le, Thanh Huy, Le, Tung T.
• Granted Patent: US 10,792,471 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2/2433 using balloon catheter
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths
• CPC Class Codes: A61M 25/0023 by the form of the lumen, e.g. cross-section, variable diameter
• CPC Class Codes: A61M 25/0662 Guide tubes

Abstract

A delivery sheath includes an elastic outer tubular layer and an inner tubular layer having a thick wall portion integrally connected to a thin wall portion. The inner tubular layer can have a compressed or folded condition wherein the thin wall portion folds onto an outer surface of the thick wall portion under urging of the elastic outer tubular layer. When an implant passes therethrough, the outer tubular layer stretches and the inner tubular layer unfolds into an expanded lumen diameter. Once the implant passes, the outer tubular layer again urges the inner tubular layer into the compressed condition with the sheath reassuming its smaller profile. The sheath may also include selectively placed longitudinal rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion and collapse, thereby reducing the push force needed to advance the implant through the sheath'"'"'s lumen.

Claims

1. A sheath comprising:

an elastic outer tubular layer defining an initial elastic lumen extending axially therethrough, the initial elastic lumen having an initial diameter; and

an inner tubular layer having a thick wall portion integrally connected to a thin wall portion, wherein the thick wall portion has a C-shaped cross section with a first longitudinally extending end and a second longitudinally extending end and wherein the thin wall portion extends between the first and second longitudinally extending ends so as to define an expanded lumen extending axially through the inner tubular layer, the expanded lumen having an expanded diameter larger than the initial diameter of the initial elastic lumen and;

wherein the inner tubular layer, in a compressed condition, extends through the initial elastic lumen of the elastic outer tubular layer with the elastic outer tubular layer urging the first longitudinally extending end under the second longitudinally extending end of the inner tubular layer; and

wherein the inner tubular layer, in a locally expanded condition, has the first and second longitudinally extending ends radially expanded apart, against the urging of the elastic outer tubular layer by passage of an implant, into a less overlapping condition with the thin wall portion extending therebetween to form the expanded lumen; and

wherein the inner tubular layer is configured to be urged by the outer elastic tubular layer into the compressed condition after passage of the implant through the expanded lumen.

2. A sheath of claim 1, wherein at least one of an outer surface of the inner tubular layer or an inner surface of the outer elastic tubular layer has a lubricious coating configured to allow free relative sliding of the outer elastic tubular layer and inner tubular layer.

3. A sheath of claim 2, wherein at least one longitudinally extending portion of the outer surface of the inner tubular layer is adhered to a corresponding longitudinally extending portion of the inner surface of the outer tubular layer.

4. A sheath of claim 1, further comprising at least one longitudinal rod coupled to an inner surface of the outer tubular layer and extending into the initial elastic lumen wherein the longitudinal rod is configured to provide a bearing surface to facilitate relative movement of the inner tubular layer within the outer tubular layer when moving between the locally expanded condition and compressed condition.

5. A sheath of claim 4, wherein the at least one longitudinal rod includes a plurality of longitudinal rods circumferentially spaced about the inner surface of the outer tubular layer.

6. A sheath of claim 5, further comprising at least one longitudinal rod coupled to an inner surface of the inner tubular layer.

7. A sheath of claim 6, wherein the at least one longitudinal rod coupled to the inner surface of the inner tubular layer includes a plurality of longitudinal rods circumferentially spaced about the inner surface of the inner tubular layer.

8. A sheath of claim 1, further comprising at least one longitudinal rod coupled to an inner surface of the inner tubular layer.

9. A sheath of claim 8, wherein the at least one longitudinal rod coupled to the inner surface of the inner tubular layer includes a plurality of longitudinal rods circumferentially spaced about the inner surface of the inner tubular layer.

10. A sheath of claim 1, further comprising a radiopaque tubular layer extending around a longitudinal portion of the elastic outer tubular layer.

11. A sheath of claim 1, wherein a distal portion of the elastic outer tubular layer is adhered to an expanded outer surface of the inner tubular layer.

12. A sheath of claim 1, wherein a distal portion of the elastic outer tubular layer and inner tubular layer are adhered to each other.

13. A sheath of claim 12, wherein the distal portion of the elastic outer tubular layer and inner tubular layer are reflowed onto each other into a sealed configuration.

14. A sheath of claim 1, further comprising a plurality of longitudinal rods embedded within the elastic outer tubular layer.

15. A sheath of claim 1, wherein a distal portion of the sheath has a flared shape.

16. A sheath of claim 15, wherein the flared shape is folded into an overlapping arrangement.

17. A method of inserting an implant into the blood vessel of a patient, the method comprising:

providing the sheath of claim 1;

inserting the sheath at least partially into the blood vessel of the patient;

advancing an implant through the inner tubular layer of the sheath;

locally expanding the inner tubular layer from the compressed condition to the locally expanded condition using the outwardly directed radial force of the implant;

locally contracting the inner tubular layer from the locally expanded condition at least partially back to the compressed condition using inwardly directed radial force of the outer elastic tubular layer.

18. The method of claim 17, wherein locally expanding further comprises moving the first and second longitudinally extending ends towards and then away from each other to reach the locally expanded condition.

19. The method of claims 17, wherein locally contracting further comprises moving the first and second longitudinally extending ends toward and then away from each other to at least partially reach the compressed condition.