Expandable mouth aspirating clot retrieval catheter

Patent metadata

Field	Value
Publication number	US-11944327-B2
Application number	US-202016809795-A
Country	US
Kind code	B2
Filing date	Mar 5, 2020
Priority date	Mar 5, 2020
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A system has an outer catheter and an inner aspirating clot retrieval catheter having an expansile distal tip for flow restriction, improved aspiration efficiency, and a large mouth into which a clot or other obstructions can be retrieved. The clot retrieval catheter can have a support tube proximal of the tip. The expansile tip can be a strut framework, and a flexible, low-modulus cover is disposed around at least a portion of the tip strut framework and the proximal support tube. The distal end of the tip can be encapsulated by a low-friction elastomeric lip for atraumatic contact with the walls of a blood vessel. The tip has a collapsed delivery configuration and expands radially into a deployed configuration. The tip strut framework, support tube, and cover can all have characteristics which enhance the deliverability of the clot retrieval catheter to the target.

First claim

The invention claimed is:

1. A system for retrieving an obstruction in a blood vessel, the system comprising:
an outer catheter; and
an inner clot retrieval catheter disposed within the outer catheter, the inner clot retrieval catheter comprising:
an expansile tip comprising a porous framework and an open distal mouth disposed at the distal end of the expansile tip, the expansile tip having a folded delivery state and an expanded deployed state;
a support tube proximal to the expansile tip comprising:
two longitudinally extending spines located on opposing sides of the support tube;
a plurality of loop ribs connected along the length of each of the two spines and external to each of the two spines, the loop ribs being axisymmetric with a longitudinal axis of the inner clot retrieval catheter and defining a lumen of the inner clot retrieval catheter extending therethrough; and

a cover radially disposed around at least a portion of the support tube and at least a portion of the expansile tip;

wherein the expansile tip has a radial dimension in the folded delivery state less than a maximum radial dimension of the expansile tip in the expanded deployed state;
wherein in the expanded deployed state, the expansile tip is self-expanded from the folded delivery state to project radially outwardly of the support tube with at least a portion of the expansile tip having the maximum radial dimension of the expansile tip; and
wherein the maximum radial dimension of the expansile tip is greater than an inner diameter of the outer catheter.

2. The system of claim 1 , wherein, in the folded delivery state, at least a portion of the expansile tip between a proximal end and a distal end and the outer catheter have a common radial dimension.

3. The system of claim 1 , wherein in the expanded deployed state the expansile tip is tapered such that a proximal end of the expansile tip has a first radial dimension and a portion of the expansile tip approximate the distal end has a second radial dimension larger than the first radial dimension;
wherein when the expansile tip is unconstrained, the second radial dimension is sized to be larger than the inner diameter of the blood vessel.

4. The system of claim 1 , wherein the porous framework of the expansile tip further comprises:
a plurality of crowns and a plurality of support arms terminating in proximal crown troughs;
wherein in the folded delivery state the framework folds about the proximal crown troughs; and
wherein the cover is radially disposed around at least a part of the framework.

5. The system of claim 4 , wherein the framework further comprises one or more narrowed segments.

6. The system of claim 4 , wherein each of the plurality of support arms of the porous framework comprise radial undulations.

7. The system of claim 4 , wherein at least one of the two spines of the support tube is respectively aligned with a support arm of the plurality of support arms.

8. The system of claim 1 , further comprising a dip zone defining a length of the framework encased by a low-friction elastomeric lip.

9. The system of claim 1 , wherein the framework is at least partially encapsulated by the cover.

10. The system of claim 1 , wherein the cover is adhered to the framework.

11. The system of claim 1 , wherein the inner clot retrieval catheter further comprises a tubular liner disposed within and lining a lumen of the support tube.

12. The system of claim 1 , wherein the cover further comprises one or more polymer jackets.

13. The system of claim 12 , wherein at least one of the one or more polymer jackets is impregnated with particles having material properties to decrease a surface's coefficient of friction.

14. The system of claim 1 , wherein at least a portion of the support tube is coated with a lubricious low-friction coating.

15. The system of claim 1 , wherein at least a portion of the cover is permeable.

16. A method of retrieving an occlusive thrombus from a blood vessel of a patient comprising the steps of:
providing an outer catheter and an inner clot retrieval catheter, the inner clot retrieval catheter comprising:
a self-expandable tip,
a support tube comprising:
a hollow structure disposed around a longitudinal axis of the inner clot retrieval catheter;
two longitudinally extending spines located on opposing sides of the support tube;
a plurality of loop ribs connected along the length of each of the two spines and external to each of the two spines, the loop ribs being axisymmetric with the longitudinal axis;

a cover disposed around the self-expandable tip and the support tube, and
a distal mouth;
restricting flow in a lumen between at least a portion of an inner wall of the outer catheter and at least a portion of an outer wall of the inner clot retrieval catheter;
accessing an arterial blood vessel of a patient using conventional means;
advancing the outer catheter and inner clot retrieval catheter to a target site;
deploying the inner clot retrieval catheter adjacent to the occlusive thrombus to radially expand the self-expandable tip;
aspirating through one or both of the outer catheter and inner clot retrieval catheter to stimulate the occlusive thrombus into the distal mouth of the inner clot retrieval catheter and capture the occlusive thrombus; and
withdrawing the inner clot retrieval catheter with the captured occlusive thrombus from the patient.

17. The method of claim 16 , further comprising the step of covering a perimeter of the distal mouth with an elastomeric lip.

18. The method of claim 16 , further comprising: covering at least part of the inner clot retrieval catheter with a low-friction coating.

19. The method of claim 16 , further comprising the step of capturing the occlusive thrombus with a mechanical thrombectomy device and withdrawing the mechanical thrombectomy device into the distal mouth of the inner clot retrieval catheter.

Assignees

• Neuravi Ltd

Inventors

• Vale David
• Kelly Ronald
• Casey Brendan
• Keating Karl

Classifications

• A61B17/22 Primary

  Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for · CPC title

• A61M25/0074

  Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable · CPC title

• A61B2017/0084

  low friction (A61B2017/00853 takes precedence) · CPC title

• A61B2017/22079

  with suction of debris · CPC title

• A61B17/221 Primary

  Gripping devices in the form of loops or baskets {for gripping calculi or similar types of obstructions (surgical snare instruments A61B17/32056)} · CPC title