Expandable sheath with interlock dilator

Patent metadata

Field	Value
Publication number	US-11944770-B2
Application number	US-202318131608-A
Country	US
Kind code	B2
Filing date	Apr 6, 2023
Priority date	Feb 3, 2020
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

An expandable introducer sheath with an interlock dilator. The present technology provides an expandable sheath with a step feature inside its distal opening, and a dilator with an interlock that includes a catch surface configured to engage with the step feature and resist further relative movement so that the body of the dilator is prevented from exiting the distal end of the expandable sheath. This interlocking engagement may allow the dilator to be used to extend and maintain tension on the expandable sheath during insertion into a patient, and then to be retracted from the expandable sheath by pulling the dilator in the opposite direction. The present technology also provides a dilator hub with a spring mechanism configured to achieve and maintain a desired tension on the expandable sheath and to prevent overextension of the expandable sheath when the dilator is being inserted into the expandable sheath.

First claim

The invention claimed is:

1. An apparatus, comprising:
a sheath comprising:
a frame having a proximal opening, a distal opening, an inner surface, and an outer surface wherein the proximal opening is configured to receive a dilator; and
a material covering the outer surface of the frame and a portion of the inner surface of the frame, and forming a step feature within the distal opening, the step feature having a first surface that abuts the inner surface of the frame and that is oriented at a first angle relative to the inner surface of the frame; and

a dilator comprising:
a body;
a tapered tip comprising at least a first tapered section and a second tapered section being proximal of the first tapered section, wherein the first tapered section decreases in diameter in a distal direction and the second tapered section decreases in diameter in a proximal direction; and
an interlock between the body and the tapered tip having a first cylindrical section with a first outer diameter, a second cylindrical section with a second outer diameter that is less than the first outer diameter, and a catch surface that abuts the first cylindrical section and that is oriented at a second angle relative to the first cylindrical section,
wherein the interlock is connected to the body by a threaded connection and is connected to the tip by flange; and
wherein the catch surface is configured to engage the first surface to resist the body of the dilator from passing out of the frame through the distal opening.

2. The apparatus of claim 1 , wherein the sheath is expandable, the sheath further comprising:
a sheath hub configured to secure the expandable sheath proximate to the distal opening of the expandable frame; and
a dilator hub comprising:
a dilator insert mold configured to secure the body of the dilator;
a spring configured to engage the dilator insert mold, and resist movement of the dilator insert mold within the dilator hub; and
one or more latches configured to lock the dilator hub to the sheath hub.

3. The apparatus of claim 2 , wherein the frame is a cylindrical or substantially cylindrical expandable frame.

4. The apparatus of claim 3 , wherein the material covering the outer surface of the expandable frame and a portion of the inner surface of the expandable frame further comprises a tapered inner edge at a distal end of the expandable sheath, the tapered inner edge being configured to engage the second tapered section of the tapered tip when the catch surface of the interlock is in engagement with the first surface of the sheath.

5. The apparatus of claim 3 , wherein the material is a polymer.

6. The apparatus of claim 5 , wherein the material is thermoplastic polyurethane.

7. The apparatus of claim 6 , wherein the expandable frame is a braided material.

8. The apparatus of claim 7 , wherein the braided material comprises strands of nitinol.

9. The apparatus of claim 6 , wherein the expandable sheath further comprises a coating applied to the expandable frame and the material.

10. The apparatus of claim 9 , wherein the coating is a lubricious coating.

11. The apparatus of claim 1 , wherein the first angle is ninety degrees.

12. The apparatus of claim 1 , wherein the first angle is less than ninety degrees.

13. The apparatus of claim 1 , wherein the second angle is ninety degrees.

14. The apparatus of claim 1 , wherein the second angle is less than ninety degrees.

15. The apparatus of claim 1 , wherein the step feature has a radial height of between 0.1 mm and 5 mm.

16. The apparatus of claim 1 , wherein the interlock is formed of stainless steel.

17. The apparatus of claim 16 , wherein the interlock is coated with a polymer.

18. The apparatus of claim 1 , wherein the interlock is formed of a polymer.

19. The apparatus of claim 18 , wherein the tapered tip is formed of polyether block amide.

20. The apparatus of claim 1 , wherein the tapered tip is formed of a polymer.

21. The apparatus of claim 1 , wherein the second tapered section comprises a transitional edge, and a distal end of the sheath comprises a complementary inner edge.

22. The apparatus of claim 21 , wherein the transitional edge is filleted, and a distal end of the sheath comprises a complementary rounded inner edge.

23. The apparatus of claim 21 , wherein the transitional edge is rounded, and a distal end of the sheath comprises a complementary filleted inner edge.

24. The apparatus of claim 21 , wherein the transitional edge comprises a chamfer, and a distal end of the sheath comprises a complementary chamfered inner edge.

25. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a cross-hatched pattern.

26. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a knurled pattern.

27. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a dimpled pattern.

28. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a pattern of dashed or continuous parallel lines.

29. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a pattern of dashed or continuous curvilinear lines.

30. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath is textured with a pattern of dashed or continuous saw-toothed lines.

31. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath comprises one or more recessed grooves.

32. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath comprises one or more raised grooves.

33. The apparatus of claim 1 , wherein at least a portion of an inner surface at a distal end of the sheath has a lubricious coating.

Assignees

• Abiomed Inc

Inventors

• Korkuch Christopher N
• Fishman Robert
• Finnegan Michael Thomas
• DeLorenzo Charles
• Gentile Andrew
• Mcloughlin Anne Gabrielle
• Swierczek Robert
• D'Agostino Matthew
• Barry Jonathan

Classifications

• A61M25/0662 Primary

  Guide tubes · CPC title

• A61M2205/0216

  Materials providing elastic properties, e.g. for facilitating deformation and avoid breaking · CPC title

• A61M29/02 Primary

  Dilators made of swellable material {(balloon catheters for angioplasty A61M25/104)} · CPC title

• A61B17/3468

  for implanting or removing devices, e.g. prostheses, implants, seeds, wires (devices for implanting seeds A61M37/0069) · CPC title

• A61M2029/025

  characterised by the guiding element · CPC title