BLOOD FLOW RESTORATION AND THROMBUS MANAGEMENT METHODS

• US 20110160763A1
• Filed: 12/28/2010
• Published: 06/30/2011
• Est. Priority Date: 10/17/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Mindframe LLC (Medtronic Plc)
• Inventors: Ferrera, David A., Cragg, Andrew H., Fulkerson, John
• Granted Patent: US 8,066,757 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• 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

1-10. -10. (canceled)

11. A thrombus management method without distal embolic protection for the treatment of ischemic stroke, the method comprising:

identifying a cerebral artery having an occlusive thrombus;

inserting a guide catheter into a patient;

inserting a guide wire through the guide catheter into the cerebral artery and through the thrombus;

inserting a microcatheter over the guidewire and through the thrombus;

positioning a distal end of the microcatheter within about a centimeter past the thrombus;

inserting an expandable tip assembly comprising a scaffold through the microcatheter;

retracting the microcatheter, thereby causing the scaffold to expand;

wherein said expansion compresses the thrombus against a wall of the cerebral artery;

wherein said compression of the thrombus restores blood flow within the cerebral artery;

wherein said restored blood flow facilitates natural lysis of the thrombus; and

macerating the thrombus by resheathing the scaffold and unsheathing the scaffold, thereby facilitating mechanical lysis and fragmentation of the thrombus to release embolic particles;

wherein the embolic particles flow in the direction of the blood flow and are not captured by any distal embolic protection member, but are instead lysed through the natural lysis process due to the restored blood flow.

12. The thrombus management method of claim 11, further comprising engaging any remaining thrombus material and removing the remaining thrombus material with the expandable tip assembly.

13. The thrombus management method of claim 11, further comprising removing the expandable tip assembly and inserting a second expandable tip assembly into the microcatheter, the second expandable tip assembly having a self-expanding scaffold with cells having a cell size configured to increase penetration of the remaining thrombus material into the cells to facilitate capture of the remaining thrombus material.

14. The thrombus management method of claim 13, further comprising engaging any remaining thrombus material and removing the remaining thrombus material with the second expandable tip assembly.

21. The thrombus management method of claim 11, wherein inserting an expandable tip assembly comprising a scaffold through the microcatheter further comprises positioning a distal end of the expandable tip assembly to substantially align with the distal end of the microcatheter.

22. The thrombus management method of claim 11, wherein said expandable tip assembly is selected based, at least in part, on a vessel diameter of the identified blood vessel.

23. The thrombus management method of claim 11, further comprising delivering one or more agents configured to promote thrombus adhesion or platelet activation to a location of the thrombus through or over the expandable tip assembly.

24. The thrombus management method of claim 11, further comprising delivering one or more lytic agents to a location of the thrombus through or over the expandable tip assembly.

25. The thrombus management method of claim 11, wherein resheathing and unsheathing the scaffold comprises movement of the microcatheter with respect to the expandable tip assembly while the expandable tip assembly remains stationary.

26. The thrombus management method of claim 11, wherein macerating the thrombus comprises resheathing the scaffold and unsheathing the scaffold multiple times.

32. The thrombus management method of claim 11, further comprising positioning the distal end of the scaffold 0.5 mm to 5 mm past an end of the thrombus, 0.5 mm to 10 mm past an end of the thrombus, 0.5 mm to 2 mm past an end of the thrombus, or aligned with an end of the thrombus.

33. The thrombus management method of claim 11, further comprising one or more of the following:

inserting the expandable tip assembly through the microcatheter prior to insertion of the microcatheter;

inserting the expandable tip assembly through the microcatheter after insertion of the microcatheter;

inserting the microcatheter within the patient via a femoral artery;

engaging any remaining thrombus material and removing the remaining thrombus material with the expandable tip assembly by resheathing and unsheathing the expandable tip assembly one or more times;

tracking the expandable tip assembly with radiopaque markers located at a distal end of the scaffold and/or proximal to the scaffold;

partially or completely removing the thrombus with the expandable tip assembly;

removing one or more softer outer layers of the thrombus through lysis and maceration and then extracting a firm inner core of the thrombus;

recapturing the scaffold within the microcatheter, repositioning the microcatheter and redeploying the scaffold at a new location after initial deployment; and

/or

visualizing the thrombus in-situ.

34. The thrombus management method of claim 11,

wherein said lysis partially or completely dissolves or shrinks the thrombus;

wherein said macerating comprises fragmenting, dissolving, or imploding the thrombus from within;

wherein said macerating comprises radial and/or axial maceration;

wherein the treatment is performed without occluding or blocking blood flow;

wherein the treatment is performed without additional structures configured to address distal embolization;

wherein blood flow is restored in less than 90 seconds, 60 seconds, 30 seconds or 15 seconds from deployment of the self-expanding scaffold within the thrombus;

wherein said lysis and/or maceration decreases a size of the thrombus by about 10% to about 30%; and

/or

wherein said method is configured to be performed in a single pass.

35. The thrombus management method of claim 11, wherein the scaffold comprises one or more of the following features:

an open proximal end;

an open distal end;

a tapered proximal end with a cut-out or everted section;

one or more flexible materials;

a cylindrical body, tapered body, triangular body, elliptical body, spiral body or undulating body;

a coating configured to increase platelet activation or adhesion of the thrombus to the scaffold;

a plurality of tether lines concentrically or eccentrically coupling a proximal end of the scaffold to a distal end of an elongate member of the expandable tip assembly;

struts having projections or protrusions configured to increase clot engagement;

struts having variable thickness along the lengths of the struts;

parallelogram-shaped cells;

cells having a uniform cell size;

cells having variable cell size at different portions of the scaffold;

cells having a height between 1 mm and 4 mm when the scaffold is in an expanded configuration;

cells having a length between 2 mm and 6 mm when the scaffold is in an expanded configuration;

X-shaped bridges between cells;

U-shaped bridges between cells;

does not comprise a backbone;

a length of about 10 mm to about 40 mm;

an expanded diameter of between 2 mm and 5 mm;

an average chronic outward force across a diameter of 1.5 mm to 4.5 mm that does not decrease by more than 10% to 90%;

a non-zero average chronic outward force across an expansion diameter of 1 mm to 4.5 mm;

formed from a laser-cut tube; and

/or

is not a rolled mesh scaffold that is configured to overlap on itself.

15. A thrombus management method for the treatment of ischemic stroke, the method comprising:

identifying an occluded blood vessel having an occlusive thrombus;

selecting an expandable tip assembly based, at least in part, on a diameter of the identified occluded blood vessel, the expandable tip assembly comprising a proximal elongate member and a distal self-expanding scaffold;

inserting the selected expandable tip assembly within the occluded vessel through a microcatheter such that the self-expanding scaffold is positioned at a location of the thrombus in a non-expanded configuration;

retracting the microcatheter, thereby causing the scaffold to expand to an expanded configuration;

wherein said expansion compresses the thrombus against a wall of the blood vessel;

wherein said compression of the thrombus restores blood flow within the blood vessel;

wherein said restored blood flow facilitates natural lysis of the thrombus; and

macerating the thrombus by resheathing the self-expanding scaffold and unsheathing the self-expanding scaffold within the microcatheter, thereby facilitating mechanical lysis and fragmentation of the thrombus.

16. The thrombus management method of claim 15, further comprising engaging the remaining thrombus material and removing the remaining thrombus material with the expandable tip assembly.

17. The thrombus management method of claim 15, further comprising removing the expandable tip assembly and inserting a second expandable tip assembly into the microcatheter, the second expandable tip assembly having a self-expanding scaffold with cells having a cell size configured to increase protrusion of the remaining thrombus material within the cells to facilitate capture of the remaining thrombus material.

18. The thrombus management method of claim 17, further comprising removing the remaining thrombus material with the second expandable tip assembly.

19. The thrombus management method of claim 15, wherein the blood vessel comprises a cerebral artery, and wherein the proximal elongate member comprises a flexible, distal portion configured to navigate curved portions of cerebral vasculature during delivery to the cerebral artery.

20. The thrombus management method of claim 15, wherein blood flow is restored in less than two minutes from deployment of the self-expanding scaffold within the thrombus.

27. The thrombus management method of claim 15, wherein inserting the selected expandable tip assembly within the occluded vessel through a microcatheter such that the self-expanding scaffold is positioned at a location of the thrombus in a non-expanded configuration further comprises positioning a distal end of the self-expanding scaffold to substantially align with the distal end of the microcatheter.

28. The thrombus management method of claim 15, further comprising delivering one or more agents configured to promote thrombus adhesion or platelet activation to a location of the thrombus through or over the expandable tip assembly.

29. The thrombus management method of claim 15, wherein resheathing and unsheathing the scaffold comprises movement of the microcatheter with respect to the expandable tip assembly while the expandable tip assembly remains stationary.

30. The thrombus management method of claim 15, wherein macerating the thrombus comprises resheathing the scaffold and unsheathing the scaffold multiple times.

31. The thrombus management method of claim 15, further comprising positioning the distal end of the scaffold 0.5 mm to 5 mm past an end of the thrombus, 0.5 mm to 10 mm past an end of the thrombus, 0.5 mm to 2 mm past an end of the thrombus, or aligned with an end of the thrombus.

36. The thrombus management method of claim 15, further comprising one or more of the following:

inserting the expandable tip assembly through the microcatheter prior to insertion of the microcatheter;

inserting the expandable tip assembly through the microcatheter after insertion of the microcatheter;

inserting the microcatheter within the patient via a femoral artery;

engaging any remaining thrombus material and removing the remaining thrombus material with the expandable tip assembly by resheathing and unsheathing the expandable tip assembly one or more times;

tracking the expandable tip assembly with radiopaque markers located at a distal end of the scaffold and/or proximal to the scaffold;

partially or completely removing the thrombus with the expandable tip assembly;

removing one or more softer outer layers of the thrombus through lysis and maceration and then extracting a firm inner core of the thrombus;

recapturing the scaffold within the microcatheter, repositioning the microcatheter and redeploying the scaffold at a new location after initial deployment; and

/or

visualizing the thrombus in-situ.

37. The thrombus management method of claim 15,

wherein said lysis partially or completely dissolves or shrinks the thrombus;

wherein said macerating comprises fragmenting, dissolving, or imploding the thrombus from within;

wherein said macerating comprises radial and/or axial maceration;

wherein the treatment is performed without occluding or blocking blood flow;

wherein the treatment is performed without additional structures configured to address distal embolization;

wherein blood flow is restored in less than 90 seconds, 60 seconds, 30 seconds or 15 seconds from deployment of the self-expanding scaffold within the thrombus;

wherein said lysis and/or maceration decreases a size of the thrombus by about 10% to about 30%; and

/or

wherein said method is configured to be performed in a single pass.

38. The thrombus management method of claim 15, wherein the scaffold comprises one or more of the following features:

an open proximal end;

an open distal end;

a tapered proximal end with a cut-out or everted section;

one or more flexible materials;

a cylindrical body, tapered body, triangular body, elliptical body, spiral body or undulating body;

a coating configured to increase platelet activation or adhesion of the thrombus to the scaffold;

a plurality of tether lines concentrically or eccentrically coupling a proximal end of the scaffold to a distal end of an elongate member of the expandable tip assembly;

struts having projections or protrusions configured to increase clot engagement;

struts having variable thickness along the lengths of the struts;

parallelogram-shaped cells;

cells having a uniform cell size;

cells having variable cell size at different portions of the scaffold;

cells having a height between 1 mm and 4 mm when the scaffold is in an expanded configuration;

cells having a length between 2 mm and 6 mm when the scaffold is in an expanded configuration;

X-shaped bridges between cells;

U-shaped bridges between cells;

does not comprise a backbone;

a length of about 10 mm to about 40 mm;

an expanded diameter of between 2 mm and 5 mm;

an average chronic outward force across a diameter of 1.5 mm to 4.5 mm that does not decrease by more than 10% to 90%;

a non-zero average chronic outward force across an expansion diameter of 1 mm to 4.5 mm;

formed from a laser-cut tube; and

/or

is not a rolled mesh scaffold that is configured to overlap on itself.