Expandable sheath with interlock dilator

Patent metadata

Field	Value
Publication number	US-12357801-B2
Application number	US-202418443687-A
Country	US
Kind code	B2
Filing date	Feb 16, 2024
Priority date	Feb 3, 2020
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

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 body having a proximal opening, a distal opening, an inner surface, and an outer surface; and
a step feature within the distal opening, the step feature having a first surface that abuts the inner surface of the body and that is oriented at a first angle relative to the inner surface of the body;

a dilator comprising:
a body;
a tapered tip; and
an interlock between the body and the tapered tip having a first section with a first outer diameter, a second section with a second outer diameter that is less than the first diameter, and a catch surface that abuts the first section and that is oriented at a second angle relative to the first section; and

wherein the dilator is configured to be inserted into the sheath through the proximal opening of the body of the sheath; and
wherein the catch surface is configured to engage the first surface of the step feature to resist the body of the dilator from moving distally beyond the distal opening of the sheath.

2. The apparatus of claim 1 , wherein:
the sheath further comprises a sheath hub configured to secure the sheath proximate to the distal opening of the body; and
the dilator further comprising a dilator hub, the 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 1 , wherein the body of the sheath comprises an expandable frame.

4. The apparatus of claim 3 , wherein the expandable frame is a braided material.

5. The apparatus of claim 4 , wherein the braided material comprises strands of nitinol.

6. The apparatus of claim 3 , wherein the sheath further comprises a material covering the outer surface of the expandable frame and a portion of the inner surface of the expandable frame.

7. The apparatus of claim 6 , wherein the material forms the step feature within the distal opening of the body of the sheath.

8. The apparatus of claim 6 , wherein the material is one of a polymer and thermoplastic polyurethane.

9. The apparatus of claim 6 , wherein the interlock further comprises a tapered section that abuts the second section.

10. The apparatus of claim 9 , wherein the tapered section is configured to engage a portion of the material proximate to the distal opening of the expandable frame.

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

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

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

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

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

16. The apparatus of claim 15 , wherein the interlock is coated with a polymer.

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

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

19. The apparatus of claim 1 , wherein the tapered tip is formed of polyether block amide.

20. The apparatus of claim 1 , wherein the tapered tip comprises a first tapered section and a second tapered section that is proximal of the first tapered section,
wherein the first tapered section of the tapered tip decreases in diameter in a distal direction, and the second tapered section decreases in diameter in a proximal direction, and
wherein a distal end of the sheath further comprises a chamfered, rounded, or filleted inner edge configured to overlap at least a portion of the second tapered section of the tapered tip of the dilator when the catch surface of the interlock is in engagement with the first surface of the step feature.

21. The apparatus of claim 20 , wherein the second tapered section comprises a chamfer, and the distal end of the sheath comprises a complementary chamfered inner edge.

22. The apparatus of claim 20 , wherein the second tapered section is filleted, and the distal end of the sheath comprises a complementary rounded inner edge.

23. The apparatus of claim 20 , wherein the second tapered section is rounded, and the distal end of the sheath comprises a complementary filleted inner edge.

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

25. The apparatus of claim 1 , wherein at least a portion of an inner surface at the distal end of the sheath is textured with one of:
a cross-hatched pattern,
a knurled pattern,
a dimpled pattern,
a pattern of dashed or continuous parallel lines,
a pattern of dashed or continuous curvilinear lines, or
a pattern of dashed or continuous saw-toothed lines.

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

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

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

Assignees

• Abiomed Inc

Inventors

• Korkuch Christopher Nason
• 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

• A61M2205/0266

  Shape memory materials · CPC title

• A61M2205/0238

  the material being a coating or protective layer · CPC title

• A61M2029/025

  characterised by the guiding element · CPC title