Dynamic Aspiration Catheter and Method

Abstract

The distal aspiration catheter consists of a catheter body with a central lumen and at least one lumen channel. The aspiration source is configured to attach to the proximal end / luer hub of the central lumen. Each lumen channel contains one mandrel, the distal portion of which extends into the distal portion of the central lumen. Upon activation of the aspiration source, clots / emboli lodged in the blood vessel are partially captured in the distal portion of the central lumen. The distal portion of the mandrel can move into the partially captured clot, causing clot fatigue. The fatigued clot can then be completely removed with a single pass of the distal aspiration catheter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 068,684, entitled "DYNAMIC ASPIRATION CATHETER AND METHOD," filed on August 21, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Many diseases are caused by the presence of unwanted material, particularly blood clots or thrombi, in blood vessels and heart chambers. Blood clots in blood vessels can be formed from fragments of blood cells, collagen, cholesterol, plaque, fat, calcified plaque, air bubbles, arterial tissue, protein aggregates (e.g., fibrin), and / or other materials or combinations thereof. Blood clots can, for example, lodge in small areas of blood vessels that supply major organs, causing loss of oxygen-rich blood flow to surrounding tissues and resulting in localized cell death and microinfarctions. Microinfarctions in the brain can cause strokes, resulting in confusion, speech problems, paralysis, visual impairment, loss of balance, and even death. In the heart, blood clots can cause myocardial infarctions, i.e., heart attacks. The presence of blood clots in blood vessels requires immediate medical intervention, as the clots can become life-threatening if left untreated.

[0003] Clots can usually be treated or removed by biological intervention, surgical intervention, or a combination of the two. Biological therapy involves administering drugs directly into the clot via catheter to dissolve it or at least stabilize it until it can be removed by the body. However, treating clots with biologics has the disadvantage that more of the body is exposed to the drugs, which can cause life-threatening bleeding complications.

[0004] Alternatively, or in addition, mechanical means may be used to remove the clot from the patient's blood vessel. Mechanical treatments typically involve aspirating, macerating, or compressing the clot within the vessel, and ultimately removing it through invasive surgery or non-invasive means such as a suction catheter connected to a suction source (e.g., a pump or syringe). Invasive and non-invasive mechanical treatments have distinct advantages in that they directly target the clot to relieve the vascular blockage without affecting non-diseased parts of the body, as opposed to using biologics.

[0005] Non-invasive mechanical thrombectomy is generally associated with thrombectomy procedures, and more specifically, peripheral thrombectomy procedures such as the treatment of deep vein thrombosis (DVT) and distal intracranial aspiration, as well as venous thrombectomy procedures.

[0006] Treatment of acute ischemic stroke using vascular aspiration embolectomy includes aspiration techniques in which the clot is drawn into a catheter by suction, but mechanical thrombectomy using a stent retriever, a self-expanding stent-like device that deploys to capture and remove the clot, has proven effective. Aspiration embolectomy has gained favor among many neurological interventionalists due to its ease of procedure and cost-effectiveness.

[0007] In aspiration embolectomy, a distal aspiration catheter (DAC) is used to remove clots or emboli from a blood vessel. In the first step of the procedure, the distal end of the catheter is placed adjacent to the clot and a vacuum force is applied through the lumen of the catheter using a pump or large volume syringe. The suction force from the syringe or pump partially engulfs or draws the emboli into the distal portion of the DAC. In cases where the emboli are partially engulfed, repeated passage of the device is required to recanalize the vessel.

[0008] However, the clinical success of aspiration embolectomy in patients depends on the "first-pass effect," defined as the complete removal of the embolus on the first attempt, thereby achieving complete or near-complete recanalization of the affected vessel after a single pass of the embolus removal device.

[0009] However, within the vessel, blood clots may change from a soft, gel-like red / purple clot to a firm, whitish clot due to cross-linking of proteins such as fibrin through a process called organization. Clots may also form hard clots due to the forward pressure of blood flow. Hard clots may form large, deeply embedded, mature clots over time that are inflexible and difficult to fully capture when suction is applied with the pump or suction syringe kit that comes with the conventional DAC. Thus, partial capture of thrombus / emboli using conventional DACs reduces the possibility of a first-pass effect and the need for additional passes through the conventional DAC to completely remove the thrombus / emboli. In addition to this, during the removal process, deeply embedded, mature thrombus / emboli may fragment and these fragments may migrate to other areas within the vessel. The above-mentioned risk factors in removing large chunks of deeply embedded, mature clots using conventional DACs reduce the possibility of a "first-pass effect" that negatively impacts the clinical outcome of the patient.

[0010] Additionally, the use of a stent retriever in combination with a conventional DAC, known as the Solumbra technique, is becoming a common method of mechanical thrombectomy for acute ischemic stroke, but the Solumbra technique has not been shown to improve first-pass efficacy versus aspiration embolectomy alone.

[0011] Therefore, there is a need for advanced DACs that overcome at least the above-mentioned problems of using conventional DACs in removing deeply embedded and mature clots and improve patient clinical outcomes by completely recanalizing the vessel after the first pass of the DAC device. Summary of the Invention

[0012] The present invention relates to aspiration catheters and methods of use that can be used to fatigue blood clots so that they can be completely removed from a blood vessel. These devices and methods can be particularly useful for clots that are hard and / or deeply embedded or that present difficulties in the removal process. In some instances, these embodiments and methods can result in recanalization of the blood vessel after a first pass of the catheter.

[0013] In one embodiment, an aspiration catheter includes a catheter body having a first lumen disposed therein and opening at a distal end of the catheter body, the first lumen configured to connect to a source of aspiration, the aspiration catheter further comprising a second lumen within a distal region of the first lumen and opening to a proximal region of the catheter body, and a first elongated mandrel disposed within the second lumen and configured to move into the first lumen to fatigue a clot at least partially located within the first lumen.

[0014] In some embodiments, the distal portion of the elongate mandrel is configured to move into the first lumen and fatigue a clot partially located within the first lumen, In some embodiments, the distal portion of the elongate mandrel is configured to translate and / or rotate and fatigue a clot partially located within the first lumen.

[0015] In some embodiments, the stiffness of the catheter body gradually decreases from the proximal region of the catheter body to the distal region of the catheter body, and in some embodiments, the distal region of the catheter body is provided with a hydrophilic coating along its length to reduce friction with the lumen of a target blood vessel during navigation of the catheter through the blood vessel.

[0016] According to some embodiments of the invention, a method for removing a blood clot from a blood vessel of a patient includes a first step of moving a catheter having a lumen over a guidewire into the blood vessel such that a distal end of the catheter lumen engages a surface of the blood clot. A suction source attached to a proximal end of the catheter lumen is then activated to partially capture the clot into the distal end of the catheter lumen. A mandrel disposed in the distal portion of the catheter lumen is moved into the partially captured clot to exhaust the clot. The exhausted clot is then completely aspirated from the blood vessel in a single pass of the catheter.

[0017] In some embodiments, the step of moving the mandrel into the partially entrapped clot to fatigue the clot further comprises rotating and / or translating the mandrel within the partially entrapped clot to fatigue the clot. [Brief description of the drawings]

[0018] The above and other aspects, features and advantages enabled by the embodiments of the present invention will become apparent and will be explained in detail from the following description of the embodiments of the present invention, taken in conjunction with the accompanying drawings.

[0019] [Figure 1] FIG. 1 is a perspective view showing aspiration embolectomy as a treatment for acute ischemic stroke using a conventional DAC that applies suction to partially engulf the clot.

[0020] [Diagram 2] FIG. 2 is a perspective view of a DAC having two mandrels in one embodiment of the present invention.

[0021] [Diagram 3] FIG. 1 is a perspective view showing aspiration embolectomy for the treatment of acute ischemic stroke using a DAC having two mandrels in accordance with one embodiment of the present invention.

[0022] [Figure 4] FIG. 1 is a perspective view showing aspiration embolectomy for the treatment of acute ischemic stroke using a DAC having two mandrels in accordance with one embodiment of the present invention.

[0023] [Figure 5A] FIG. 2 is a perspective view of a handle of a DAC and an attached mandrel in one embodiment of the present invention.

[0024] [Figure 5B] FIG. 2 is a perspective view of a handle of a DAC and an attached mandrel in one embodiment of the present invention.

[0025] [Figure 6] FIG. 5C is a perspective view of a DAC with a handle attached as shown in FIGS. 5A and 5B according to one embodiment of the present invention.

[0026] [Figure 7A] FIG. 1 is a perspective view of a mandrel having a cylindrical wedge-shaped distal portion.

[0027] [Figure 7B] FIG. 1 is a perspective view of a mandrel having a flat wire-like distal portion.

[0028] [Figure 7C] FIG. 2 is a perspective view of a mandrel having a semi-cylindrical distal portion.

[0029] [Figure 8]FIG. 2 is a perspective view of a DAC having four mandrels in one embodiment of the present invention.

[0030] [Figure 9] FIG. 1 is a perspective view illustrating aspiration embolectomy for the treatment of acute ischemic stroke using a DAC with multiple cutting blades in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Next, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention can be embodied in many different forms, and should not be interpreted as being limited to the embodiments described in this specification. Rather, the following embodiments are intended to enable those skilled in the art to comprehensively and completely understand the scope of the present invention through this disclosure. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the drawings, the same elements are designated by the same numbers.

[0032] The terms clot, thrombus, and embolism are used synonymously herein and generally refer to a mass or associated collection of blood cells, collagen, cholesterol, plaque, fat, calcified plaque, air bubbles, arterial tissue, protein aggregates (e.g., fibrin), and / or other fragments or combinations thereof.

[0033] As previously mentioned, existing aspiration catheter techniques may not be effective in removing large or deeply embedded clots from within a blood vessel in a single pass through the aspiration catheter. This is due to incomplete capture of the clot within the aspiration catheter and / or fragmentation of the clot during removal. FIG. 1 shows a conventional distal access catheter (DAC) 20 for use in removing a large, deeply embedded clot 10 from within a blood vessel. The DAC 20 may have an exterior shape with an inner diameter typically ranging from 1.3 mm (4F) to 4 mm (12F). In one example, the clot 10 may be lodged in the middle cerebral artery, causing an acute ischemic stroke that occludes a large blood vessel. In the removal procedure, the distal end of the DAC 20 is positioned adjacent to the clot 10, and a vacuum force is applied to the proximal end of the lumen by an attached pump or aspiration syringe, thereby partially capturing the clot within the lumen at the distal portion of the DAC 20.

[0034] If the clot 10 is deeply embedded and larger than the diameter of the DAC 20, application of vacuum force alone may not be effective in recanalizing the vessel. In other words, the first pass of the device may not completely remove the clot. While the use of larger diameter DACs and / or application of stronger vacuum forces may be possible, larger profile DACs may be difficult to navigate through the distal intracranial circulation and may be detrimental to the lumen of the vessel, causing dissection / vasospasm.

[0035] The present invention seeks to address the shortcomings of existing devices and techniques by removing the clot after a single pass through the DAC in a procedure. Some embodiments described herein relate to a DAC (more commonly referred to as a catheter) that includes a mechanism for inducing clot fatigue. More specifically, the DAC includes a mechanism for applying physical stress to the clot in a manner that reduces the clot's hardness, size, and / or cohesion. Such stress can be achieved by a mandrel, a cutting device with sharp and / or blunt edges, or a similar component configured to move relative to the clot.

[0036] The term "clot fatigue" is generally defined as a process that mechanically stresses a clot, altering / reducing its hardness, size, and / or cohesion, and causing partial or total disruption of the clot. Clot fatigue can be particularly useful in drawing the clot into a catheter and removing it from the patient.

[0037] DACs can be used to remove clots / emboli from any blood vessel, including those from which clots / emboli may be removed by embodiments of the invention, including those in acute ischemic stroke, in the pulmonary circulation (e.g., the pulmonary artery), in the systemic venous circulation (e.g., the jugular vein, sigmoid sinus, transverse sinus, superior sagittal sinus, inferior sagittal sinus, vena cava, pelvic vein, femoral vein, subclavian vein), or in the arterial circulation (e.g., the aorta or its large and middle branches).

[0038] Some embodiments of a DAC according to the present invention include a plurality of protruding structures, e.g., mandrels, at a distal portion within the lumen of the DAC. When the distal end of the DAC engages a clot, the distal portions of the protruding structures undergo rotational and / or translational motion to induce "clot fatigue" and assist in partially or completely engulfing the clot by applying a vacuum force to the lumen of the DAC.

[0039] 2 illustrates an embodiment of a DAC 100 that includes one or more mandrels configured to create mechanical stress in the clot and induce clot fatigue. Although the DAC 100 is illustrated with a first mandrel 140 having a distal portion 142 and a second mandrel 150 having a distal portion 152, any number of mandrels may be used (e.g., 1, 2, 3, 4, 5, 6, 7, or 8). The mandrels 140, 150 may be configured to move in a variety of different ways and angles to create or induce fatigue or stress in the clot. For example, the mandrels may move longitudinally (i.e., axially relative to the catheter body), rotationally (i.e., rotating about the axis of the mandrel), radially inward (i.e., toward the cross-sectional center of the catheter), radially outward (i.e., away from the cross-sectional center of the catheter), laterally (i.e., toward and away from the outer periphery of the catheter), or any combination thereof.

[0040] The mandrels 140, 150 may be engaged or actuated upon engagement with the clot. Depending on the location and configuration of the mandrels 140, 150, the catheter 100 may first apply suction to aspirate the clot at least partially near the distal end of the DAC 100, preferably into the aspiration lumen 101 of the DAC 100. However, the mandrels 140, 150 may be configured to cause fatigue or stress on the clot without first applying suction. For example, they may be configured to extend to the very distal edge of the DAC 100 or even slightly beyond the distal end of the DAC 100.

[0041] The mandrels described herein generally have an elongated body of sufficient length to extend between the proximal and distal portions of the DAC 100. The mandrel preferably has at least some rigidity sufficient to permit distal and proximal movement through the passageway of the DAC 100. For example, the mandrel may be comprised of a single wire, a coated wire, a helical wire coil, or the like. The mandrel may be similar in design to commonly known guidewires, and in some cases, a guidewire may be used as the mandrel.

[0042] As shown in Figure 3, a fatigued clot has an overall reduced diameter, reduced hardness, and / or reduced cohesive strength, which allows for better complete capture within the DAC 100, preferably with a single pass of the instrument, thus eliminating the need for increased suction forces that could cause blood loss and shock to other organs of the treated patient.

[0043] The DAC 100 may include a tubular catheter body having a stiff proximal shaft. The stiffness of the proximal shaft facilitates attachment of the proximal end 120 of the DAC 100 to a handle 200 (FIGS. 6A and 6B) or catheter hub. The stiffness of the tubular catheter decreases gradually from the proximal to the distal portion. The distal end 110 of the DAC 100 is configured with a soft tip to ensure smooth movement of the DAC 100 relative to the distal portion of the intracranial vessel.

[0044] In some embodiments, the DAC 100 comprises a lumen 101 having a proximal portion 102 and a distal portion 104. The lumen 101 can have a variety of different sizes, such as diameters ranging from about 6 to 8 French, depending on the site of use within a patient.

[0045] In some embodiments, the outer portion of the distal DAC lumen 104 is hydrophilically coated. The hydrophilic coating is used in the distal portion of the intracranial vessel to reduce friction with the vessel lumen as the DAC 100 moves. In one example, the distal 60 centimeters of the DAC lumen 104 is hydrophilically coated to reduce friction with the vessel lumen during movement. In another example, the distal 30 centimeters of the DAC lumen 104 is hydrophilically coated to reduce friction with the vessel lumen during movement. In yet another example, the distal 20 centimeters of the DAC lumen 104 is hydrophilically coated to reduce friction with the vessel lumen during movement. In some embodiments, the hydrophilic coating is comprised of a commercially available coating solution such as, but not limited to, Hydak (Biocoat, Inc., Horsham, PA), which is UV and heat curable, or Lubricent (Harland Medical Systems, Inc., Eden Prairie, MN), which is UV curable.

[0046] The DAC 100 also includes a passageway or channel for each mandrel that extends between the proximal end of the DAC 100 and the distal end of the DAC 100. These passageways or channels generally include a distal opening and a proximal opening. The mandrels can be positioned externally from the distal opening and can extend through the proximal opening (e.g., for manual actuation or into a motorized powered handle for motor actuation). In some embodiments, each channel is configured to carry a single mandrel, although larger diameter channels configured to carry multiple mandrels are possible. The channels and their distal openings can be positioned at different circumferential locations from one another. For example, the two channels can be positioned at approximately 180 degrees from one another (i.e., diametrically opposite positions), at 90 degrees from one another, at 45 degrees from one another, at 25 degrees from one another, or at any angle and / or combination of angles.

[0047] The location of the channels along the periphery of the DAC 100 (e.g., within the wall or between wall layers of the DAC 100) can provide several advantages. First, such an arrangement can accommodate a relatively large number of channels while maintaining a sufficient size of the aspiration lumen 101. As an example, as shown in FIG. 2, two lumen channels 160 and 170 are arranged along the periphery of the DAC 100, with a first mandrel 140 located within the lumen channel 160 and a second mandrel 150 located within the lumen channel 170. In another example, as shown in FIG. 8, four lumen channels 160, 160A, 170, 170A and four mandrels 140, 140A, 150, 150A are arranged along the circumference of the DAC 100. However, it should be understood that other numbers of channels and mandrels may be used, such as 2, 3, 4, 5, 6, 7, 8, or more.

[0048] Another advantage of the peripheral placement of the lumen channel and mandrel is that the mandrel does not impede passage of clots through the lumen 104 of the DAC 100, increasing the likelihood of a first pass effect. According to the present invention, one or more mandrels may be placed through the aspiration lumen 101, however, due to the potential for these to block clots, the use of the channels described above is preferred.

[0049] 2 shows an example of a specific arrangement of passages or channels located between the outer cylindrical jacket 106 and the inner cylindrical liner 108. A first lumen channel 160 and a second lumen channel 170 are disposed within the space between the outer cylindrical jacket 106 and the inner cylindrical liner 108. The first lumen channel 160 may include a first port 162 at a distal portion of the DAC 100 and a second port 164 at a proximal portion of the DAC 100. The first mandrel 140 is disposed within the lumen of the first lumen channel 160 such that its distal portion 142 extends outwardly from the distal first port 162 and its proximal end 146 extends outwardly from the proximal second port 164.

[0050] Similarly, the second lumen channel 170 includes a first port 172 at a distal portion of the DAC 100 and a second port 174 at a proximal portion of the DAC 100. The second mandrel 150 is disposed within the lumen of the second lumen channel 150 such that its distal portion 152 extends outwardly from the distal first port 172 and its proximal end 156 extends outwardly from the proximal second port 174.

[0051] The proximal second ports 164, 174 can be used similarly to a rapid exchange port and can be located at an opening on the exterior of the DAC 100 at a proximal location to allow for manual actuation by the user. Alternatively, the proximal second ports 164, 174 can open into the catheter hub to allow for manual actuation by the user. Alternatively, the proximal portion can open directly into the handle to allow for motor actuation, as described with respect to further embodiments later herein.

[0052] Although two channels 160, 170 are shown in Figure 2, any number of lumen channels and mandrels are possible, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 lumen channels may be included. For example, as shown in the alternative embodiment of Figure 8, there are four lumen channels 160, 160A, 170, 170A and four mandrels 140, 140A, 150, 150A disposed around the periphery of the lumen section of the DAC 100.

[0053] The distal first ports and / or distal portions of the mandrels (e.g., first ports 162, 172, distal portions 142, 152, and mandrels 140, 150) can be configured to direct the distal portions of the mandrels into the main aspiration lumen 101 of the DAC 100 at different angles relative to the axis of the DAC 100. For example, the distal portions of the mandrels may be configured to exit the first ports at an angle that is generally parallel to the axis of the DAC 100 (see, e.g., FIG. 2), or at an angle of 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, or any angle between or greater than these values ​​relative to the axis of the DAC 100. Additionally, the distal first ports (e.g., first ports 162, 172) can be located either at the same distance or at different distances from the distal end of catheter 100. In other words, each distal first port can be located at a different longitudinal position. If there are more than two distal first ports, some of the ports may be located at the same longitudinal position and others at different positions (e.g., two ports located 2 mm and two ports located 4 mm from the distal end of catheter 100).

[0054] The angle at which the first port exits can be achieved in a few different ways. First, the first port itself can be curved, causing the mandrel to exit at a particular angle. Second, at least the distal portion of the mandrel can be constructed of a shape memory material that has a memorized or heat set shape that bends when unconstrained. Either or both of these approaches can be used.

[0055] In some embodiments of the invention, to ensure "clot fatigue," the mandrel may translate (i.e., proximally and distally), rotate about the mandrel axis, or a combination of the two. Additionally, multiple mandrels may have the same or different operating characteristics. For example, one mandrel may rotate while another mandrel translates. In another example, one mandrel may extend distally and remain stationary while another mandrel translates.

[0056] In one example, the translational motion may consist of the mandrel moving proximally and distally by about 0.5-5 mm. In another example, the translational motion may be back and forth relatively slowly (e.g., about once every 1-2 seconds) or relatively quickly (e.g., about once every 0.5-0.01 seconds). In another example, the rotational motion of the mandrel may be continuous in a single direction or may periodically switch direction and rotate back and forth.

[0057] Returning to the example DAC 100 shown in Figure 2, the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 perform dynamic motion (e.g., rotational and translational motion) within the partially captured clot 10 as shown in Figure 3 to macerate the clot 10. The macerated clot 10 has a generally weakened or reduced structure such that it can be fully or nearly fully captured within the DAC 100 by applying suction within the lumen of the DAC 100.

[0058] In the particular example approach shown in Figure 4, "clot fatigue" can be achieved by the distal portion 152 of the second mandrel 150 extending distally to hold the partially captured clot 10 in place while the distal portion 142 of the first mandrel 140 provides dynamic rotational and translational motion and / or longitudinal vibration. In yet some other embodiments, "clot fatigue" can be achieved by the distal portion 142 of the first mandrel 140 providing dynamic rotational and translational motion and / or longitudinal vibration within the clot. A fatigued clot 10 has a generally weakened structure and / or reduced diameter, which allows it to be fully or nearly fully captured within the lumen of the DAC 100 upon application of suction.

[0059] The distal portions (e.g., 142 and 152) of the mandrels (e.g., 140 and 150) described herein can have a variety of different shapes to aid in penetrating or disrupting the structure of the clot. For example, the ends of the mandrels can be point-shaped, flattened rectangular, triangular, partially cylindrical, and similar variations.

[0060] FIG. 7A shows an exemplary shape 142A that decreases in diameter distally and has a flat surface and a rounded bottom surface. FIG. 7B shows another exemplary shape 142B that has a rectangular shape with flat top and bottom surfaces. FIG. 7C shows another exemplary shape 142C that has a semi-cylindrical shape with a flat top surface. In some embodiments, the diameter of the shape or structure of the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 depends on the inner diameter of the lumen 101 of the DAC 100. In one embodiment, when the DAC 100 is used to remove blood clots from a blood vessel in the brain, the diameter of the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 may be about 0.0014 inches.

[0061] In some embodiments of the present invention, the mandrels (e.g., 140 and 150) may be made of a shape memory material, such as, for example, Nitinol, stainless steel, or cobalt chrome. Additionally or alternatively, the mandrels may be made of a radiopaque material, such as, for example, platinum or tantalum. In some embodiments, the mandrels 140, 150 have guidewire-like flexibility so that they can be easily moved through the first and second lumen channels 160, 170 of the DAC 100.

[0062] The mandrels described herein can be custom made for the DAC100, although an existing guidewire can also be used (eg, a 0.035 inch guidewire).

[0063] Additionally, one of the channels 160, 170 may be used initially with a guidewire to initially position the DAC 100 at the desired clot location. For example, the guidewire may be initially positioned with its distal end located within or near the target clot. The distal end of the guidewire may be positioned to extend from the distal first port 162, through the channel 160, and out the second port 164. The DAC 100 may then be advanced over the guidewire until its distal end is located near the clot. Finally, the guidewire is withdrawn and the mandrel 140 is advanced into the channel 160, allowing the clot fatigue and aspiration procedure to proceed.

[0064] As previously mentioned, the translational and rotational movement of the mandrels may be performed manually in some embodiments, for example, a physician may grasp the proximal end of one or more mandrels and move them proximally / distally and rotationally.

[0065] As an alternative embodiment, the mandrels 140, 150 can be operated via a motorized mechanism that converts the motion of an electric motor into the desired translational and rotational motion. As shown in the embodiment of Figures 5A and 5B, the proximal end 144 of the mandrel 140 is attached to a first interface 210 and the proximal end 154 of the mandrel 150 is attached to a second interface 220. The proximal end of the first interface 210 is attached to a motorized actuator 250 and the proximal end of the second interface 220 is also attached to a motorized actuator 250. The first interface 210, the second interface 220, and the actuator 250 are disposed within the handle 200 and are actuated by an interface element, such as, for example, the depression of a button (not shown) disposed on the handle 200 and electrically connected to the actuator 250. Figure 5A shows the translational motion of the mandrels 140, 150, and Figure 5B shows the rotational motion of the mandrels 140, 150. Both motions may be used simultaneously or at different times on the same mandrel.

[0066] 6 generally illustrates the DAC 100 and the motorized handle 200 attached thereto. In this embodiment, the port 164 through which the mandrel 140 enters the first lumen channel 160 is located at the proximal end 120 of the DAC 100. Similarly, the port 174 through which the mandrel 150 enters the second lumen channel 170 is located at the proximal end 120 of the DAC 100. Thus, the mandrel 140 is pushed through port 164 and out port 162, and the mandrel 150 is pushed through port 174 and out port 172, such that the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 are located within the distal portion 104 of the DAC lumen. The handle 200 may be separately attachable to the proximal end of the DAC 100 or may be integrally formed therewith. In some embodiments, when the actuator 250 is activated, for example by pressing a button on the handle 200, the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 undergo translational and rotational movements to induce “clot fatigue” in the clot partially trapped within the distal portion 104 of the DAC lumen.

[0067] In some embodiments of the invention, the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 do not protrude outwardly from the distal end 110 of the DAC. For example, the distal end 110 of the DAC 100 may be provided with a mechanism to prevent migration outwardly from the DAC, such as a hard stop or lip (not shown), to prevent the distal portion 142 of the first mandrel 140 and the distal portion 152 of the second mandrel 150 from migrating further distally outwardly from the catheter lumen and into the blood vessel.

[0068] In an alternative embodiment, "clot fatigue" can be achieved by reducing the size of the clot using one or more cutting elements disposed within the distal portion of the main lumen 101 of the DAC 100. The one or more cutting elements are defined as having one or more cutting surfaces. The cutting surfaces may have sharp, partially sharp, and / or blunt surfaces that are sized, positioned, and / or configured to be capable of at least partially cutting into the clot.

[0069] The cutting elements can have a variety of different shapes, such as flat planar shapes, point shapes (e.g., surface 142A in FIG. 7A may be considered a cutting element), cylindrical shapes, intersecting planar shapes (e.g., X-shaped), helical corkscrew shapes, or similar designs. In some embodiments, the cutting edges can be sharp, blunt, or a combination of both (e.g., sharp and blunt areas). As a specific example, a cutting element can have a cutting surface that is blunt on the outside of the cutting element and sharp on the inside of the cutting element, which can act to draw in the clot and make a cut within the cutting element (e.g., a helical shape with a sharp inner surface).

[0070] In some embodiments, the cutting elements may be attached to or even integral with the distal end of the mandrel or a similar structure so as to be manually actuated in a manner similar to that described herein with respect to the mandrel. In other embodiments, the cutting elements may be connected to a shaft or other elongated element configured for manual or motor-driven rotation. In other embodiments, one or more cutting elements may be fixed and stationary to the interior surface of the lumen of the DAC 100 or other member (e.g., a helical shape with a sharp interior surface).

[0071] 9 shows an embodiment of the DAC 100 having a generally tubular cutting element 192 that defines multiple cutting surfaces. In this embodiment, the cutting element 192 is connected to an elongated shaft 190 and configured for manual or motor-driven rotation. For example, an actuator or similar motor-driven device can be connected (not shown) to the proximal end of the elongated shaft 190 and electrically activated by pressing a button (not shown). The cutting element 192 may translate (i.e., move proximally and distally), rotate about the axis of the cutter 190, or a combination of the two. The cutting element 192 includes multiple sharp cutting surfaces that are angled radially or diametrically inward relative to the generally cylindrical cutting element. This allows the cutting element 192 to engage the clot and cause clot fatigue in the clot.

[0072] One method of the present invention for removing large and / or deeply embedded clots will now be described with reference to the device previously described. First, a guidewire and / or delivery sheath is deployed within the patient such that the guidewire or sheath allows the distal end 104 of the DAC 100 to be positioned near the clot. For example, the DAC 100 may be inserted over a guidewire into the target vessel and advanced toward the clot such that the distal end 110 of the DAC 100 is positioned against or near the surface of the clot 10.

[0073] Once the clot is positioned against or engaged with the distal end 110 of the DAC 100, a suction source connected to the DAC 100 is activated to aspirate the clot at least partially into the distal portion 104 of the DAC lumen. Aspiration can be accomplished with a manually actuated syringe or a motor-driven pump.

[0074] The mandrel is then manually manipulated or an actuator is actuated to cause translational and / or rotational movement of the distal end of the mandrel within the clot, thereby inducing "clot fatigue" within the partially trapped clot (e.g., Figs. 3, 4). These mandrel movements may occur simultaneously with suction, or suction may be temporarily halted while the mandrel is moving. In either case, suction and mandrel movement continue until the clot has moved into the lumen of the DAC 100, at which point suction and mandrel movement may be halted, if desired. At the end of the procedure, the DAC 100 containing the clot is withdrawn from the vessel. In some embodiments of the present invention, contrast may be injected during treatment to determine successful recanalization of the vessel.

[0075] Although the present invention has been described in terms of specific embodiments and applications, those skilled in the art may, in light of this teaching, create further embodiments and modifications without departing from the spirit or beyond the scope of the claimed invention. It is therefore to be understood that the drawings and descriptions herein are presented by way of example to facilitate understanding of the invention and should not be construed as limiting its scope.

Claims

1. a catheter body having an aspiration lumen opening at a distal end thereof; a first mandrel lumen extending through the catheter body and having a first distal opening in a distal region of the aspiration lumen and disposed about the catheter body; and a first mandrel disposed within the first mandrel lumen, the first mandrel lumen directing a distal end of the first mandrel into the distal region of the aspiration lumen to fatigue a clot partially drawn into the aspiration lumen. A clot removal catheter.

2. A catheter comprising: a second mandrel lumen disposed around the catheter body and having a second opening within the distal region of the suction lumen; and a second mandrel disposed within the second mandrel lumen, wherein the second mandrel lumen fatigues the clot partially drawn into the suction lumen by directing a distal end of the second mandrel into the distal region of the suction lumen. The clot removal catheter of claim 1 .

3. A clot removal catheter as described in claim 2, characterized in that it comprises a third mandrel lumen and a fourth mandrel lumen arranged around the catheter body and having an opening in the distal region of the suction lumen, a third mandrel arranged within the third mandrel lumen, and a fourth mandrel arranged within the fourth mandrel lumen, wherein the third mandrel lumen and the mandrel lumen direct distal ends of the third mandrel and the fourth mandrel into the distal region of the suction lumen.

4. The clot removal catheter of claim 2 , wherein the first mandrel lumen and the second mandrel lumen are disposed within a wall of the catheter body.

5. The clot removal catheter of claim 4, wherein the first mandrel lumen and the second mandrel lumen are disposed between an outer jacket and an inner liner of the catheter body.

6. The clot removal catheter of claim 2, wherein the first mandrel lumen and the second mandrel lumen are disposed at different longitudinal positions relative to a distal end of the catheter body.

7. 2. The clot removal catheter of claim 1, wherein the first mandrel lumen is at an angle ranging from 25 degrees to 180 degrees relative to a longitudinal axis of the catheter body.

8. 2. The clot removal catheter of claim 1, wherein the first mandrel is constructed of a shape memory material that is imparted with a memory shape such that a distal portion of the first mandrel is biased radially inward within the aspiration lumen.

9. 2. The clot removal catheter of claim 1, further comprising a handle portion connected to a proximal end of the catheter body, the handle comprising an actuator connected to a first mandrel, the actuator causing the first mandrel to translate, rotate, or both.

10. 10. The clot removal catheter of claim 1, further comprising a stop configured to prevent a distal end of the first mandrel from passing distally out of the aspiration lumen.

11. The clot removal catheter of claim 1, wherein the distal end of the first mandrel has a flat rectangular shape, a triangular shape, or a semi-cylindrical shape.

12. The clot removal catheter of claim 1, wherein the first mandrel lumen has a first proximal opening at a proximal portion of the catheter body.

13. The clot removal catheter of claim 1, wherein the first distal opening is formed so that the first mandrel exits at an angle that is generally parallel to the axis of the catheter body or at 5 degrees, 10 degrees, 15 degrees, 25 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 75 degrees, 80 degrees, 85 degrees, or 90 degrees relative to the axis of the catheter body.

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