Source: http://www.google.com/patents/US8070791?dq=6289460
Timestamp: 2015-08-30 21:25:23
Document Index: 371062880

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 61', 'Application No. 61', 'Application No. 61']

Patent US8070791 - Multiple layer embolus removal - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsSystems, 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...http://www.google.com/patents/US8070791?utm_source=gb-gplus-sharePatent US8070791 - Multiple layer embolus removalAdvanced Patent SearchPublication numberUS8070791 B2Publication typeGrantApplication numberUS 12/981,363Publication dateDec 6, 2011Filing dateDec 29, 2010Priority dateOct 17, 2007Fee statusPaidAlso published asEP2367482A1, EP2367482A4, US8066757, US8197493, US8574262, US20110160742, US20110160757, US20110160760, US20110160761, US20110160763, US20110238106, US20120016406, US20120022576, US20120041460, US20120041475, US20120316600, US20140121758, WO2011082319A1Publication number12981363, 981363, US 8070791 B2, US 8070791B2, US-B2-8070791, US8070791 B2, US8070791B2InventorsDavid A. Ferrera, Andrew H. Cragg, John FulkersonOriginal AssigneeMindframe, Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (105), Non-Patent Citations (15), Referenced by (6), Classifications (28), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetMultiple layer embolus removal
US 8070791 B2Abstract
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.
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:
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:
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.
This application is a continuation of U.S. patent application Ser. No. 12/980,039 filed Dec. 28, 2010, which is a continuation-in part application Ser. No. 12/651,353 filed Dec. 31, 2009, which is a continuation-in part application of U.S. patent application Ser. No. 12/123,390 filed May 19, 2008, which claims priority to the following provisional applications: U.S. Provisional Application No. 60/980,736, filed Oct. 17, 2007; U.S. Provisional Application No. 60/987,384, filed Nov. 12, 2007; U.S. Provisional Application No. 60/989,422, filed Nov. 20, 2007; U.S. Provisional Application No. 61/015,154, filed Dec. 19, 2007; U.S. Provisional Application No. 61/019,506, filed Jan. 7, 2008; and U.S. Provisional Application No. 61/044,392, filed Apr. 11, 2008.
U.S. patent application Ser. No. 12/980,039 is also a continuation-in part application of U.S. patent application Ser. No. 12/136,737, filed Jun. 10, 2008. U.S. patent application Ser. No. 12/980,039 is also a continuation-in part application of U.S. patent application Ser. No. 12/422,105, filed Apr. 10, 2009. U.S. patent application Ser. No. 12/980,039 is also a continuation-in part application of U.S. patent application Ser. No. 12/711,100, filed Feb. 23, 2010. U.S. patent application Ser. No. 12/980,039 is also a continuation-in part application of U.S. patent application Ser. No. 12/753,812, filed Apr. 2, 2010. U.S. patent application Ser. No. 12/980,039 is also a continuation-in-part application of U.S. patent application Ser. No. 12/182,370, filed Jul. 30, 2008. U.S. patent application Ser. No. 12/980,039 is also a continuation-in-part application of U.S. patent application Ser. No. 12/475,389, filed May 29, 2009. This application is related to the following commonly-owned application: U.S. patent application Ser. No. 12/469,462, filed May 20, 2009. The entire contents of each of the above-listed applications are hereby expressly incorporated by reference herein.
The present disclosure generally relates to devices, systems, and methods for use in the treatment of vascular issues. More particularly, several embodiments relate to systems and methods for providing early blood flow restoration, maceration of an embolus, lysis of the embolus, and optional retrieval of any non-lysed portions of the embolus.
The pathological course of a blood vessel that is blocked is a gradual progression from reversible ischemia to irreversible infarction (cell death). A stroke is often referred to as a “brain attack” and occurs when a blood vessel in the brain becomes blocked or ruptures. An ischemic stroke occurs when a blood vessel in the brain becomes blocked. Occlusions may be partial or complete, and may be attributable to one or more of emboli, thrombi, calcified lesions, atheroma, macrophages, lipoproteins, any other accumulated vascular materials, or stenosis. Ischemic strokes account for about 78% of all strokes. Hemorrhagic strokes, which account for the remaining 22% of strokes, occur when a blood vessel in the brain ruptures. Stroke is the third leading cause of death in the United States, behind heart disease and cancer and is the leading cause of severe, long-term disability. Each year roughly 700,000 Americans experience a new or recurrent stroke. Stroke is the number one cause of inpatient Medicare reimbursement for long-term adult care. Total stroke costs now exceed $45 billion per year in US healthcare dollars. An occlusion in the cerebral vasculature can destroy millions of neurons and synapses of the brain.
If not addressed quickly, the destruction of neurons and synapses of the brain after a stroke can result in slurred speech, paralysis, loss of memory or brain function, loss of motor skills, and even death. Thus, there remains a need for 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 distal to the clot or occlusion reduces the destruction to neurons and neurovasculature. Immediate blood flow restoration facilitates natural lysis of the clot and also can reduce or obviate the concern for distal embolization due to fragmentation of the clot. There also remains a need for systems, methods and devices for the treatment of acute ischemic stroke that provide for progressive treatment based upon the nature of the clot, wherein the treatment involves immediate restoration of blood flow, in-situ clot management, and clot removal depending on the particular circumstances of the treatment. The progressive treatment can be provided by a kit of one or more devices. According to several embodiments of the present disclosure, clot therapy may have one or more of at least three objectives or effects: maceration of a clot, removal of a clot, and lysis of a clot.
In accordance with several embodiments, a thrombus management method for the treatment of ischemic stroke without distal embolic protection is provided. In some embodiments, the thrombus management method comprises identifying a blood vessel having an occlusive thrombus. In some embodiments, the method comprises inserting a guide catheter into a patient. In some embodiments, the method comprises inserting a guide wire through the guide catheter into the occluded vessel and through the thrombus. In several embodiments, the guide wire follows a path of least resistance through the thrombus. In some embodiments, the guide wire does not travel through the thrombus but travels to the side of the thrombus (for example, if the thrombus is not positioned across the entire diameter, or height, of the vessel). In some embodiments, the thrombus management method comprises inserting a microcatheter over the guidewire (which may be through the thrombus or to the side of the thrombus as described above). In some embodiments, the method comprises positioning a distal end of the microcatheter within about a centimeter past the thrombus. In some embodiments, the method further comprises positioning a distal end of the expandable tip assembly to substantially align with the distal end of microcatheter.
In some embodiments, the method comprises inserting an expandable tip assembly comprising a scaffold through the microcatheter. In some embodiments, the method comprises retracting the microcatheter, thereby causing the scaffold to expand. The expansion of the scaffold can compress the thrombus against a wall of the blood vessel. The compression of the thrombus can restore blood flow within the blood vessel and the restored blood flow can facilitate natural lysis of the thrombus. In some embodiments, the thrombus management method comprises macerating the thrombus by resheathing the scaffold and unsheathing the scaffold (e.g., by advancing and retracting the microcatheter), thereby facilitating mechanical lysis and fragmentation of the thrombus to release embolic particles. The embolic particles can flow in the direction of the blood flow and may not be captured by any distal embolic protection member, but can instead be lysed through the natural lysis process due to the restored blood flow. In some embodiments, resheathing and unsheathing the scaffold comprises movement of the microcatheter with respect to the expandable tip assembly while the expandable tip assembly remains stationary. Macerating the thrombus can comprise resheathing the scaffold and unsheathing the scaffold one time or multiple times (e.g., two times, three times, four times, five times, six times) In some embodiments, blood flow is restored in less than two minutes (e.g., about 90 seconds, 60 seconds, 30 seconds, 15 seconds, etc.) from deployment of the scaffold within the thrombus.
In some embodiments, the thrombus management method comprises engaging a remaining portion of the thrombus after said maceration and extracting or removing said remaining portion of the thrombus from the blood vessel. The engaging and extracting of the remaining portion of the thrombus can be performed by the expandable tip assembly that performed the blood flow restoration and maceration (e.g., the first expandable tip assembly) or by a second expandable tip assembly configured or adapted for thrombus removal. If a second expandable tip assembly is used, the second expandable tip assembly can be inserted into the microcatheter after removing the first expandable tip assembly from the microcatheter after macerating the thrombus. The first expandable tip assembly can comprise a self-expanding scaffold with open cells having a cell size configured or adapted to facilitate blood flow restoration and natural lysis of the thrombus. The second expandable tip assembly can comprise a self-expanding scaffold with open cells having a cell size configured to increase penetration, or protrusion, of the remaining thrombus material into the cells to facilitate capture of the remaining thrombus material.
In some embodiments, the thrombus management method comprises delivering one or more agents configured to promote thrombus adhesion or platelet activation or one or more lytic agents to a location of the thrombus through or over the expandable tip assembly. For example, the agents can be infused through a lumen of the expandable tip assembly or around the expandable tip assembly through a lumen of the microcatheter.
In accordance with several embodiments of the invention, a thrombus management method comprises identifying a blood vessel having an occlusive thrombus and selecting an expandable tip assembly based, at least in part, on a diameter of the identified occluded blood vessel. The expandable tip assembly can comprise a proximal elongate member and a distal self-expanding scaffold. In some embodiments, the method comprises 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. Positioning the self-expanding scaffold at a location of the thrombus can refer to a location that spans (partially or completely) the thrombus. For example, if a thrombus in a vessel has a height and a length, wherein the length is substantially parallel with the longitudinal axis of the vessel, spanning the thrombus includes, but is not limited to, positioning a device to extend partially across the length of the thrombus, to extend from one end of the thrombus to the other end of the thrombus, or to extend past (e.g., just past, such as 0.5 to 5 mm past, 1 mm to 10 mm past, or overlapping ranges thereof)) one or both ends of the thrombus. Depending on whether the height of the thrombus extends along the entire height, or diameter, of the vessel, the non-expanded device may be in contact with a portion of the thrombus or may not be in contact with the thrombus. The self-expanding scaffold can be positioned either within the thrombus or outside the thrombus (e.g., depending on the location of the microcatheter and the size of the thrombus). The microcatheter can then be retracted, thereby causing the scaffold to expand to an expanded configuration. The expansion can compress the thrombus against a wall of the blood vessel, thereby restoring blood flow within the blood vessel by creating a bypass channel through or past the thrombus. The restored blood flow facilitates natural lysis of the thrombus. In some embodiments, the proximal elongate member of the expandable tip assembly comprises a flexible, distal portion configured to navigate curved portions of the cerebral vasculature.
In accordance with several embodiments of the invention, a method for providing multiple layer embolus removal from a cerebral artery is provided. In some embodiments, the method comprises identifying an embolus within a cerebral artery and inserting an expandable reperfusion device within the cerebral artery to the location of the embolus. The embolus, or thrombus, can comprise one or more soft outer layers and a firm fibrin core. In some embodiments, the method comprises expanding the reperfusion device within the embolus, thereby establishing one or more blood flow channels through or past the embolus. The one or more blood flow channels facilitate natural lysis of the embolus to remove one or more outer layers of the embolus. The one or more outer layers of the embolus can comprise platelets and red blood cells.
In some embodiments, the method comprises removing the reperfusion device and inserting an expandable embolus removal device within the cerebral artery to the location of the embolus. In some embodiments, the method comprises expanding the embolus removal device within a remaining portion of the embolus, thereby engaging the remaining portion of the embolus. In some embodiments, the method comprises extracting the remaining portion of the embolus with the embolus removal device from the cerebral artery by removing the embolus removal device.
In some embodiments, the reperfusion device comprises an expandable tip assembly including a proximal elongate member and a distal self-expanding scaffold. The scaffold of the reperfusion device can comprise open cells having a cell size that is configured to decrease, hinder, prevent, deter, discourage, inhibit, or reduce penetration, or protrusion, of the embolus within the scaffold, thereby increasing blood flow through the scaffold because the flow channel through the scaffold is larger. In some embodiments, the embolus removal device comprises an expandable tip assembly including a proximal elongate member and a distal self-expanding scaffold. The scaffold of the embolus removal device can comprise open cells having a cell size that is configured to increase, promote, facilitate, enhance, allow, or enable penetration, or protrusion, of the remaining portion of the embolus material within the scaffold to facilitate capture of the remaining portion of the embolus. The cell size of the embolus removal device can be larger than the cell size of the reperfusion device.
In accordance with some embodiments, a method for providing multiple layer embolus removal comprises identifying an embolus having an outer layer and an inner core. In some embodiments, the method comprises establishing one or more blood flow channels through the embolus to restore blood flow. In one embodiment, establishing one or more blood flow channels comprises inserting an expandable reperfusion scaffold within or adjacent the thrombus and expanding it. In some embodiments, the method comprises 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. Free flow can refer to downstream flow without obstruction or capture, such as a distal embolic protection device (e.g., a basket, a net, a filter). The disturbance may be caused by maceration of the embolus with an expandable scaffold, thereby enhancing lysis of the embolic particles. In some embodiments, restored blood flow causes further release of embolic particles from the outer layer of the embolus. In some embodiments, the method comprises extracting the inner core of the embolus. The one or more outer layers of the embolus can comprise softer layers than the inner core of the embolus. The inner core can comprise a fibrin core that has a hardness that exceeds the one or more outer layers of the embolus.
In accordance with several embodiments of the invention, a method for providing progressive therapy for thrombus management in blood vessels is provided. In some embodiments, the method comprises identifying a thrombus within a blood vessel. In some embodiments, the method comprises inserting an expandable reperfusion device within the blood vessel to the location of the thrombus. The expandable reperfusion device can comprise an expandable reperfusion scaffold having a plurality of interconnected struts that form cells having a cell size that is sized and configured to reduce, prevent, hinder, or deter penetration, or protrusion, of the thrombus into the reperfusion scaffold, thereby increasing a diameter of a flow path established by the reperfusion scaffold. In some embodiments, the method comprises deploying the reperfusion device within the thrombus, thereby compressing the thrombus against the inner vessel wall and establishing one or more blood flow channels through the thrombus. The one or more blood flow channels can facilitate natural lysis of the thrombus. In some embodiments, the method comprises removing the reperfusion device.
In some embodiments, the method for providing progressive therapy for thrombus management of blood vessels comprises inserting an expandable thrombus removal device within the blood vessel to the location of the thrombus. The expandable thrombus removal device can comprise an expandable removal scaffold having a plurality of interconnected struts that form cells having a cell size that is sized and configured to allow thrombus penetration, or protrusion, within the cells, thereby facilitating engagement of the thrombus by the removal scaffold. In some embodiments, the method comprises deploying the thrombus removal device within a remaining portion of the thrombus, thereby engaging the remaining portion of the thrombus. In some embodiments, the method comprises extracting the remaining portion of the thrombus engaged by the