Multiple layer embolus removal

• US 8,070,791 B2
• Filed: 12/29/2010
• Issued: 12/06/2011
• Est. Priority Date: 10/17/2007
• Status: Expired due to Fees

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Mindframe LLC (Medtronic Plc)
• Inventors: Ferrera, David A., Cragg, Andrew H., Fulkerson, John
• Primary Examiner(s): Jackson, Gary
• Assistant Examiner(s): Bachman, Lindsey
• Application Number:
  US12/981,363
• Publication Number:
  US 20110160761A1
• Time in Patent Office: 342 Days
• Field of Search: 606/159, 606/200, 606/108, 606/110, 606/113, 606/114, 606/127, 606/170, 606/174, 606/180, 606/191, 606/192, 606/194, 606/198, 623/1.12, 623/1.11
• US Class Current: 623/1.12
• 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. An embolus management method for addressing an occlusive embolus within a blood vessel by providing a sheathed scaffold assembly for removal of embolus material from a cerebral artery, comprising:

identifying an embolus within a cerebral artery;

wherein the embolus comprises an outer layer and an inner core;

establishing one or more blood flow channels through the embolus to restore blood flow;

disturbing the embolus by mechanical maceration of the embolus to release embolic particles from the outer layer, thereby allowing the embolic particles to freely flow in the direction of the blood flow without capturing said embolic particles;

wherein said maceration is performed by sheathing and unsheathing the scaffold assembly;

wherein said restored blood flow causes lysis of the embolic particles; and

extracting the inner core of the embolus.

2. The method of claim 1, wherein said restored blood flow causes further release of embolic particles from the outer layer of the embolus.

3. The method of claim 1, wherein the outer layer of the embolus comprises a softer portion than the inner core of the embolus.

4. The method of claim 1, wherein the outer layer comprises platelets and red blood cells.

5. The method of claim 1, wherein the inner core of the embolus comprises a fibrin core that has a hardness that exceeds the hardness of the outer layer of the embolus.

6. The method of claim 1, wherein the scaffold assembly comprises a self-expandable scaffold, and wherein establishing one or more blood flow channels through the embolus to facilitate natural lysis of the embolus comprises unsheathing the scaffold, thereby allowing the scaffold to self-expand within the embolus.

7. The method of claim 1, wherein the steps of establishing one or more blood flow channels through the embolus to restore blood flow, disturbing the embolus by mechanical maceration of the embolus to release embolic particles from the outer layer, thereby allowing the embolic particles to freely flow in the direction of the blood flow without capturing said embolic particles, and extracting the inner core of the embolus are performed using the scaffold assembly, wherein the scaffold assembly comprises a self-expandable scaffold that is configured to expand when unsheathed and that is configured to be compressed when sheathed.

8. The method of claim 1, wherein the scaffold assembly comprises an expandable tip assembly having a distal self-expanding scaffold tethered to a proximal elongate pusher.

9. The method of claim 8, wherein the distal self-expanding scaffold further comprises one or more of the following features:

an open, tapered proximal end having a cut-out or everted section;

an open distal end; and

a plurality of tether lines concentrically or eccentrically coupling a proximal end of the distal self-expanding scaffold to a distal end of the proximal elongate pusher.

10. The method of claim 1, wherein said maceration comprises fragmenting, dissolving, or imploding the embolus from within the embolus and wherein said method is performed without occluding or blocking blood flow.

11. An embolus management method for addressing an occlusive embolus within a blood vessel by providing multiple layer embolus removal, comprising:

identifying an embolus within a cerebral artery;

inserting an expandable reperfusion device within the cerebral artery to the location of the embolus;

wherein the expandable reperfusion device comprises an expandable tip assembly including a proximal elongate member and a distal self-expanding scaffold,

wherein the expandable reperfusion device has an open, non-filtering distal end;

expanding the reperfusion device within the embolus, thereby establishing one or more blood flow channels through the embolus;

wherein the one or more blood flow channels facilitate natural lysis of the embolus to remove one or more outer layers of the embolus;

macerating the embolus with the distal self-expanding scaffold by resheathing and then unsheathing the distal self-expanding scaffold through advancement and retraction of a microcatheter;

removing the reperfusion device;

inserting an expandable embolus removal device within the cerebral artery to the location of the embolus;

expanding the embolus removal device within a remaining portion of the embolus, thereby engaging the remaining portion of the embolus;

extracting the remaining portion of the embolus with the embolus removal device from the cerebral artery; and

removing the embolus removal device.

12. The method of claim 11, wherein the embolus removal device comprises an expandable tip assembly including a proximal elongate member and a distal self-expanding scaffold.

13. The method of claim 12, wherein the distal self-expanding scaffold of the embolus removal device further comprises:

an open, tapered proximal end having a cut-out or everted section;

an open distal end; and

a plurality of tether lines concentrically or eccentrically coupling a proximal end of the scaffold to a distal end of the proximal elongate member.

14. The method of claim 11, wherein inserting an expandable reperfusion device within the cerebral artery to the location of the embolus comprises inserting the expandable reperfusion device through a microcatheter such that the self-expanding scaffold is in a non-expanded configuration.

15. The method of claim 14, wherein expanding the reperfusion device within the embolus comprises retracting the microcatheter, thereby allowing the self-expanding scaffold to deploy to an expanded configuration.

16. The method of claim 11, wherein the one or more outer layers of the embolus comprise platelets and red blood cells.

17. The method of claim 11, wherein the remaining portion of the embolus comprises a firm fibrin core of the embolus.

18. The method of claim 11, further comprising visualizing the embolus in-situ and/or tracking the expandable reperfusion device and expandable embolus removal device with radiopaque markers of said expandable reperfusion device and/or said expandable embolus removal device.

19. The method of claim 11, wherein said maceration comprises fragmenting, dissolving, or imploding the embolus from within the embolus and wherein said method is performed without occluding or blocking blood flow.

20. The method of claim 11, wherein the scaffold further comprises an open, tapered proximal end having a cut-out or everted section and a plurality of tether lines concentrically or eccentrically coupling a proximal end of the scaffold to a distal end of the proximal elongate member.