FLOW RESTORATION METHODS

• US 20120016406A1
• Filed: 09/26/2011
• Published: 01/19/2012
• Est. Priority Date: 10/17/2007
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Mindframe LLC (Medtronic Plc)
• Inventors: Ferrera, David A., Cragg, Andrew H., Fulkerson, John
• Application Number:
  US13/245,190
• Publication Number:
  US 20120016406A1
• Time in Patent Office: Days
• US Class Current: 606/194
• CPC Class Codes: A61B 17/12118 for positioning in conjunction with a stent
• CPC Class Codes: A61B 17/1214 Coils or wires
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 2017/00309 Cut-outs or slits
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22034 for gripping the obstruction or the tissue part from inside
• CPC Class Codes: A61B 2017/22039 eccentric
• CPC Class Codes: A61B 2017/22079 with suction of debris
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2017/2212 having a closed distal end, e.g. a loop
• CPC Class Codes: A61B 2017/2215 having an open distal end
• CPC Class Codes: A61B 2017/32096 for slowly cutting through tissue, e.g. stent like temporary implants having sharp edges
• CPC Class Codes: A61B 2090/3966 Radiopaque markers visible in an X-ray image
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• CPC Class Codes: A61M 25/0074 Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable

Abstract

Systems, methods, and devices for the treatment of acute ischemic stroke that provide immediate blood flow restoration to a vessel occluded by a clot and, after reestablishing blood flow, address the clot itself. Immediate blood flow restoration advantageously can facilitate natural lysis of the clot and also can reduce or obviate the concern for distal embolization due to fragmentation of the clot. Several embodiments of the invention provide for progressive, or modular, treatment based upon the nature of the clot. For example, the progressive treatment can comprise a three-step progressive treatment process that includes immediate restoration of blood flow, in-situ clot management, and/or clot removal depending on the particular circumstances of the treatment. The in-situ clot management can include, for example, lysis and maceration. The progressive, or modular, treatment can be provided by a system or kit of one or more treatment devices.

Claims

1. A method of providing immediate flow restoration to an obstructed blood vessel of the cerebral vasculature of a subject, comprising:

identifying an obstructed blood vessel within the cerebral vasculature of a subject, the obstructed blood vessel having a thrombus that is obstructing blood flow to the brain;

inserting a catheter to a location within the obstructed vessel such that a distal end of the catheter is positioned distal to the thrombus;

inserting a revascularization device through the catheter, the revascularization device comprising a proximal elongate pusher and a distal self-expandable scaffold eccentrically tethered to a distal end of the proximal elongate pusher and having an open, non-filtering distal end;

advancing the revascularization device to a position within the catheter such that, when the catheter is retracted, the distal self-expandable scaffold expands at a location of the thrombus;

retracting the catheter, thereby unsheathing the distal self-expandable scaffold and allowing said scaffold to deploy to an expanded state, thereby compressing the thrombus against a luminal wall of the obstructed vessel and restoring blood flow through the obstructed blood vessel,

wherein the restored blood flow facilitates natural lysis of the thrombus,

wherein the natural lysis and compression of the thrombus cause fragmentation of at least a portion of the thrombus into a plurality of embolic fragments,

wherein one or more of said embolic fragments pass through the open, non-filtering distal end of said scaffold downstream of the thrombus,

wherein said scaffold exerts continuous radial pressure at the location of the thrombus to further facilitate blood flow through the blood vessel as the thrombus lyses;

at least partially resheathing said scaffold within the catheter by advancing the catheter distally over the scaffold; and

removing the catheter and revascularization device from the subject.

2. The method of claim 1, further comprising inserting a guidewire within the obstructed blood vessel and through the thrombus.

3. The method of claim 2, wherein the catheter is inserted over the guidewire.

4. The method of claim 3, wherein the proximal pusher of the revascularization device is a hypotube having a polymeric liner to improve trackability, and wherein the revascularization device is inserted within the catheter over the guidewire.

5. The method of claim 1, wherein inserting a catheter to a location within the obstructed vessel such that a distal end of the catheter is positioned distal to the thrombus comprises inserting the catheter through the thrombus such that, when the catheter is retracted, the distal self-expandable scaffold expands within the thrombus.

6. The method of claim 1, wherein the distal self-expandable scaffold is non-detachably tethered to a distal end of the proximal pusher.

7. The method of claim 1, further comprising tracking the revascularization device to confirm proper positioning with respect to the thrombus using one or more markers coupled to the distal self-expandable scaffold.

8. The method of claim 1, wherein deploying the distal self-expandable scaffold at the location of the thrombus comprises creating an immediate flow channel within the blood vessel of at least about 50% of the diameter of the blood vessel.

9. The method of claim 1, wherein the proximal pusher is a variable-pitch hypotube.

10. The method of claim 1, wherein the proximal pusher is a wire.

11. The method of claim 1, further comprising morselizing at least a portion of the thrombus by mechanical manipulation of the distal self-expandable scaffold.

12. The method of claim 1, further comprising removing at least a portion of the thrombus captured by the distal self-expandable scaffold.

13. A method of restoring blood flow through an obstructed blood vessel of the brain of a subject, comprising:

identifying an obstructed blood vessel within the cerebral vasculature of a subject, the obstructed blood vessel having a thrombus that is obstructing blood flow to the brain;

inserting a distal end of the catheter through the thrombus within the obstructed vessel and positioning the distal end of the catheter distal to the thrombus;

inserting a revascularization device through the catheter, the revascularization device comprising a proximal elongate pusher and a distal self-expandable scaffold eccentrically tethered to a distal end of the proximal elongate pusher and having an open, non-filtering distal end;

advancing the revascularization device to a position within the catheter such that, when the catheter is retracted, the distal self-expandable scaffold at least partially spans the thrombus;

retracting the catheter, thereby unsheathing the distal self-expandable scaffold and allowing said scaffold to deploy to an expanded state, thereby engaging the thrombus from within and compressing the thrombus against a luminal wall of the obstructed vessel,

wherein said compression of the thrombus immediately restores blood flow within the blood vessel past the thrombus,

wherein the restored blood flow facilitates natural lysis of the thrombus,

wherein the natural lysis and compression of the thrombus cause fragmentation of at least a portion of the thrombus into a plurality of embolic fragments,

wherein one or more of said embolic fragments pass through the open, non-filtering distal end of said scaffold downstream of the thrombus,

wherein said scaffold exerts continuous radial pressure at the location of the thrombus to further facilitate blood flow through the blood vessel as the thrombus lyses; and

removing the catheter and revascularization device from the subject.

14. The method of claim 13, further comprising resheathing said scaffold within the catheter by advancing the catheter distally over the scaffold.

15. The method of claim 13, further comprising inserting a guidewire within the obstructed blood vessel and through the thrombus and wherein the catheter is inserted over the guidewire.

16. The method of claim 13, further comprising morselizing at least a portion of the thrombus by mechanical manipulation of the distal self-expandable scaffold.

17. The method of claim 13, further comprising removing at least a portion of the thrombus captured by the distal self-expandable scaffold.

18. The method of claim 13, wherein deploying the distal self-expandable scaffold at the location of the thrombus comprises creating an immediate flow channel within the blood vessel of at least about 50% of the diameter of the blood vessel.

19. The method of claim 13, further comprising detaching the distal self-expandable scaffold from the proximal elongate pusher.

20. The method of claim 13, wherein the distal self-expandable scaffold is non-detachably tethered to a distal end of the proximal pusher.

21. A method of restoring blood flow through an obstructed blood vessel of the brain of a subject, comprising:

identifying an obstructed blood vessel within the cerebral vasculature of a subject, the obstructed blood vessel having a thrombus that is obstructing blood flow to the brain;

inserting a distal end of the catheter through the thrombus within the obstructed vessel and positioning the distal end of the catheter distal to the thrombus;

inserting a revascularization device through the catheter, the revascularization device comprising a proximal elongate pusher and a distal self-expandable scaffold eccentrically tethered to a distal end of the proximal elongate pusher and having an open, non-filtering distal end;

advancing the revascularization device to a position within the catheter such that, when the catheter is retracted, the distal self-expandable scaffold at least partially spans the thrombus;

retracting the catheter, thereby unsheathing the distal self-expandable scaffold and allowing said scaffold to deploy to an expanded state, thereby engaging the thrombus from within and compressing the thrombus against a luminal wall of the obstructed vessel,

wherein said compression of the thrombus immediately restores blood flow within the blood vessel past the thrombus,

wherein the restored blood flow facilitates natural lysis of the thrombus,

wherein the natural lysis and compression of the thrombus cause fragmentation of at least a portion of the thrombus into a plurality of embolic fragments,

wherein one or more of said embolic fragments pass through the open, non-filtering distal end of said scaffold downstream of the thrombus,

wherein said scaffold exerts continuous radial pressure at the location of the thrombus to further facilitate blood flow through the blood vessel as the thrombus lyses;

morselizing at least a portion of the thrombus by mechanical manipulation of the distal self-expandable scaffold;

at least partially resheathing the scaffold within the catheter to facilitate capture of the thrombus; and

removing the catheter and revascularization device from the subject.

22. The method of claim 21, further comprising inserting a guidewire within the obstructed blood vessel and through the thrombus and wherein the catheter is inserted over the guidewire.

23. The method of claim 21, further comprising removing at least a portion of the thrombus captured by the distal self-expandable scaffold.