Patent Description:
Clot retrieval devices are used in mechanical thrombectomy for endovascular intervention, often in cases where patients are suffering from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Acute obstructions can include a clot, misplaced devices, migrated devices, large emboli, and the like. Thromboembolism occurs when part or all of a thrombus breaks away from the blood vessel wall. This clot (now called an embolus) is then carried in the direction of blood flow. An ischemic stroke can result if the clot lodges in the cerebral vasculature. A pulmonary embolism can result if the clot originates in the venous system or in the right side of the heart and lodges in a pulmonary artery or branch thereof. Clots can also develop and block vessels locally without being released in the form of an embolus-this mechanism is common in the formation of coronary blockages.

There are significant challenges associated with designing clot retrieval devices that can deliver high levels of performance. First, there are a number of access challenges that make it difficult to deliver devices. In cases where access involves navigating the aortic arch (such as coronary or cerebral blockages) the configuration of the arch in some patients makes it difficult to position a guide catheter. These difficult arch configurations are classified as either type <NUM> or type <NUM> aortic arches with type <NUM> arches presenting the most difficulty.

The tortuosity challenge is even more severe in the arteries approaching the brain. For example, it is not unusual at the distal end of the internal carotid artery that the device will have to navigate a vessel segment with a <NUM>° bend, a <NUM>° bend, and a <NUM>° bend in quick succession over a few centimeters of vessel. In the case of pulmonary embolisms, access is through the venous system and then through the right atrium and ventricle of the heart. The right ventricular outflow tract and pulmonary arteries are delicate vessels that can easily be damaged by inflexible or high profile devices. For these reasons it is desirable that the clot retrieval device be compatible with as low profile and flexible a guide catheter as possible.

Second, the vasculature in the area in which the clot can be lodged is often fragile and delicate. For example, neurovascular vessels can be more fragile than similarly sized vessels in other parts of the body and can be in a soft tissue bed. Excessive tensile forces applied on these vessels could result in perforations and hemorrhage. Pulmonary vessels can be larger than those of the cerebral vasculature, but are also delicate in nature, particularly more distal vessels.

Additionally, the clot can have any of a range of morphologies and consistencies. For example, the clot can be difficult to grip and improper grip can lead to fragmentation which can cause embolization. Long strands of softer clot material can also tend to lodge at bifurcations or trifurcations, resulting in multiple vessels being simultaneously occluded over significant lengths. More mature and organized clot material can be less compressible than softer fresher clot, and under the action of blood pressure it can distend the compliant vessel in which it is lodged. Furthermore, the properties of the clot can be significantly changed by the action of the devices interacting with it. In particular, compression of a blood clot can cause dehydration of the clot and can result in a dramatic increase in both clot stiffness and coefficient of friction.

Lastly, traditional clot retrieval devices employing a pinch mechanism to capture a clot can require the delivery microcatheter to be forward post deployment of the clot retrieval device in order to effectively pinch a clot using the device. However, this can add an additional step in the procedure, thereby resulting in a potentially cumbersome and non-optimal procedure. Due to the critical nature of such procedures, it can be critical to capture a clot in a timely and effective manner.

The challenges described above need to be overcome for devices to provide a high level of success in removing clot and restoring flow. The disclosure of <CIT> provides a method of removing clot from a vessel, including delivering a clot retrieval device across the clot, wherein the clot retrieval device includes an inner body having a collapsed delivery configuration and an expanded deployed configuration; and an outer body extending along a longitudinal axis and at least partially overlying the inner body. The disclosure of <CIT> provides a clot removal device for removing clot from a body vessel that comprises an expandable structure and an elongate member. The disclosure of <CIT> provides a self-expanding intravascular medical device including a multi-component assembly with a self-expanding outer cage component comprising a plurality of struts; and a single cell wave-shape component disposed within the self-expanding outer cage component forming a channel therein. The disclosure of <CIT> provides devices and methods of engaging, capturing, and retrieving emboli.

P The invention is defined in claim <NUM>. It is desirable for a clot retrieval device to remove a clot from cerebral arteries in patient suffering from AIS, from coronary native or graft vessels in patients suffering from MI, and from pulmonary arteries in patients from PE and from other peripheral arterial and venous vessels in which a clot is causing at least a partial occlusion. Example devices and methods presented herein may be suitable for at least some of such procedures and/or similar procedures.

An example clot retrieval device can have a constrained delivery configuration and a clot engaging configuration and can be configured to remove a clot from a blood vessel. The device can include a first expandable framework having a first plurality of struts that form a first body and a second expandable framework having a second plurality of struts that form a second body. In the clot engaging configuration, the first body can be configured to move from a first position to a second position in relation to the second body.

The first body can have a first inner diameter and the second body can have a second inner diameter. The first inner diameter and the second inner diameter can be substantially equal.

When the first body is in the first position, the first plurality of struts and the second plurality of struts can be disengaged such that a plurality of clot reception spaces are formed.

When the first body is in the second position, the first plurality of struts and the second plurality of struts can be engaged such that an average cross-sectional area of the plurality of clot reception spaces decreases upon movement of the first body from the first position to the second position.

The first plurality of struts can include a radially extending strut and the second plurality of struts can include an eye through which the radially extending strut radially extends. The eyelet and the radially extending strut can be configured such that when the first body moves from the first position to the second position, the radially extending strut engages the eyelet to inhibit the first plurality of struts from moving, in relation to the second plurality of struts, beyond the second position. Each eyelet can be tapered.

The clot retrieval device can include a polymer coating to engage the first plurality of struts and the second plurality of struts. The polymer coating can be configured to fail, thereby allowing the first body to move from the first position to the second position.

At least one polymer membrane can be affixed to the first plurality of struts and the second plurality of struts such that the polymer membrane is disposed between the first body and the second body.

The at least one polymer membrane can be in a folded configuration when the first body is in the first position and the at least one polymer membrane can transition to a stretched configuration when the first body moves proximally to the second position.

The clot retrieval device can include a third expandable framework having a third framework of struts that form a third body. The first body and the second body can at least partially surround the third body in the clot engaging configuration.

A proximal end of the clot retrieval device can include a plurality of expanded struts that form a collar.

The third framework of struts can include at least one disconnected strut.

The third body can include a plurality of clot reception spaces. The plurality of clot reception spaces can be configured to engage the clot.

Another example clot retrieval device can have a constrained delivery configuration and a clot engaging configuration and can be configured to remove a clot from a blood vessel. The device can include an inner expandable framework, an outer expandable framework, and a spring. The inner expandable framework can be affixed to a pull wire and can include a first plurality of struts that form an inner body. The outer expandable framework can be affixed to the pull wire and can include a second plurality of struts that form an outer body at least partially surrounding the inner body. The spring can be affixed to a distal end of the pull wire and can have a compressed configuration and an elongated configuration. In the clot engaging configuration, the inner body can be configured to move from a first position to a second position in relation to the outer body such that the spring transitions from the compressed configuration to the elongated configuration.

The outer expandable framework can include a plurality of clot reception spaces that are configured to pinch the clot between the inner body and the outer body when the inner body moves from the first position to the second position.

An example method to capture a clot can include deploying a clot retrieval device proximate the clot where the clot retrieval device includes a first expandable framework forming a first body and a second expandable framework forming a second body at least partially surrounding the first body. The method can further include moving the first body in relation to the second body to pinch at least a portion of the clot between the first body and the second body and capturing one or more fragments of the clot.

Moving the first body in relation to the second body to pinch at least a portion of the clot between the first body and the second body can include applying tension to a pull wire where the pull wire is in mechanical communication with the first body.

The method can further include retracting the first body and the second body simultaneously.

The clot retrieval device can further include a third expandable framework having a third plurality of struts that form a third body. The first body and the second body can at least partially surround the third body. In such configuration, the method can further include retracting the third body in a proximal direction to engage the first body and the third body.

The design and functionality described in this application is intended to be exemplary in nature and is not intended to limit the instant disclosure in any way. Those having skill in the pertinent art will appreciate that the teachings of the disclosure may be implemented in a variety of suitable forms, including those forms disclosed herein and additional forms known to those having skill in the art pertinent.

It will be apparent from the foregoing description that, while particular embodiments of the present disclosure have been illustrated and described, various modifications can be made without departing from the scope of the disclosure. For example, while the embodiments described herein refer to particular features, the disclosure includes embodiments having different combinations of features. The disclosure also includes embodiments that do not include all of the specific features described. Specific embodiments of the present disclosure are now described in detail with reference to the figures, wherein identical reference numbers indicate identical or functionality similar elements.

The terms "distal" or "proximal" are used in the following description with respect to a position or direction relative to the treating physician. "Distal" or "distally" are a position distant from or in a direction away from the physician. "Proximal" or "proximally" or "proximate" are a position near or in a direction toward the physician.

In the following description, numerous specific details are set forth. But it is to be understood that examples of the disclosed technology can be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail in order not to obscure an understanding of this description. References to "one embodiment," "an embodiment," "example embodiment," "some embodiments," "certain embodiments," "various embodiments," "one example,' "an example," "some examples," "certain examples," "various examples," etc., indicate that the embodiment(s) and/or example(s) of the disclosed technology so described may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase "in one embodiment" or the like does not necessarily refer to the same embodiment, example, or implementation, although it may.

By "comprising" or "containing" or "including" or "having" is meant that at least the named compound, element, particle, configuration, or method step is present in the composition or device or method, but does not exclude the presence of other compounds, materials, particles, method steps, or configurations even if the other such compounds, material, particles, method steps, or configurations have the same function as what is named.

Throughout the specification and the claims, the following terms take at least the meanings explicitly associated herein, unless the context clearly dictates otherwise. The term "or" is intended to mean an inclusive "or. " Further, the terms "a," "an," and "the" are intended to mean one or more unless specified otherwise or clear from the context to be directed to a singular form.

Unless otherwise specified, the use of the ordinal adjectives "first," "second," "third," etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described should be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

As discussed herein, a "patient" or "subject" can be a human or any animal. It should be appreciated that an animal can be a variety of any applicable type, including, but not limited to, mammal, veterinarian animal, livestock animal or pet-type animal, etc. As an example, the animal can be a laboratory animal specifically selected to have certain characteristics similar to a human (e.g., rat, dog, pig, monkey, or the like).

Accessing the various vessels within the vascular, whether they are coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of a number of conventional, commercially-available accessory products. These products, such as angiographic materials and guidewires are widely used in laboratory and medical procedures. When these products are employed in conjunction with the system and methods of this disclosure in the description below, their function and exact constitution are not described in detail.

The disclosed technology can generally include a clot removal device having a sliding cage (e.g., a first body) and an outer cage (e.g., a second body) radially surrounding the sliding cage. A pull wire can be affixed to the sliding cage such that upon tension being applied to the pull wire, the sliding cage can displace proximally and independently of the outer cage. Upon the sliding cage displacing proximally, the sliding cage and the outer cage can pinch the clot. In some instances, the clot removal device can further include an inner channel (e.g., third body). The outer cage and the sliding cage can radially surround the inner channel. Upon tension being applied, the inner channel can move proximally and independently of the outer cage and sliding cage. Subsequently, the sliding cage can move proximally in relation to the outer cage and independently of the outer cage. In such configuration the sliding cage and the outer cage can further pinch the clot and the clot can thereby become further integrated within the clot removal device. Accordingly, the efficient and effective removal of a clot from a blood vessel can be performed.

Referring now to the Figures, <FIG> illustrate side views of an example clot retrieval device <NUM> in a clot engaging configuration. The clot retrieval device <NUM> can include a first expandable framework <NUM> and a second expandable framework <NUM>. The first expandable framework <NUM> can include a first plurality of struts <NUM> and the second expandable framework <NUM> can include a second plurality of struts <NUM>.

The first expandable framework <NUM> and the second expandable framework <NUM> can be collapsible into a restraining sheath (e.g., a microcatheter) sized to traverse a clot or other obstruction. The clot retrieval device <NUM> can be positioned proximate the clot in a blood vessel. Optionally, the clot retrieval device <NUM> can traverse the clot such that a portion of the clot remove device <NUM> is forward in relation to the clot. The first expandable framework <NUM> and the second expandable framework <NUM> can each be configured to self-expand upon release from the restraining sheath. Upon release, the clot retrieval device <NUM> can transition from a constrained delivery configuration to the clot engaging configuration such that the clot retrieval device <NUM> can be subsequently used to facilitate clot removal, flow restoration, and or fragmentation protection.

Upon transitioning to the clot engaging configuration, the first plurality of struts <NUM> of the first expandable framework <NUM> can expand to form a first body <NUM>. Similarly, the second plurality of struts <NUM> of the second expandable framework <NUM> can expand to form a second body <NUM>. The second body <NUM> can at least partially radially surround the first body <NUM>. Optionally, the second body <NUM> can entirely radially surround the first body <NUM>.

Both the first expandable framework <NUM>, including the first plurality of struts <NUM>, and the second expandable framework <NUM>, including the second plurality of struts <NUM>, can preferably be made from a material capable of recovering its shape automatically once released from the constrained delivery configuration. A super-elastic or pseudo-elastic material such as Nitinol or an alloy of similar properties is particularly suitable. The material can have a high recoverable strain sufficient to resiliently collapse and expand as described herein. The material could be in many forms such as wire or strip or sheet or tube. A particularly suitable manufacturing process is to laser cut a Nitinol tube and then heat set and electropolish the resultant structure to create a framework of struts and connecting elements. For example, the first expandable framework <NUM> and the second expandable framework <NUM> can each be laser cut from a Nitinol tube having an outer diameter of approximately <NUM> millimeters. The first and second expandable frameworks <NUM>, <NUM> can be any of a range of shapes as understood by a person skilled in the pertinent art according to the teachings disclosed herein. The first and second expandable frameworks <NUM>, <NUM> can be rendered visible under fluoroscopy through the addition of alloying elements or through a variety of other coatings or marker bands. For instance, the first and second expandable frameworks <NUM>, <NUM> can include material and/or markers with radiopaque material including, but not limited to Barium Sulphate, Bismuth SubCarbonate, Barium OxyChloride, Gold, Tungsten, Platinum, Iridium, Tantalum, and alloys thereof. Specifically, in some examples, the first and second expandable frameworks <NUM>, <NUM> can include radiopaque markers having an Iridium alloy, and more specifically a Platinum-Iridium alloy.

As illustrated in <FIG>, in the clot engaging configuration, the first body <NUM> and the second body <NUM> can each have a substantially cylindrical shape. Further, the first body <NUM> can have a first inner diameter <NUM> and the second body <NUM> can have a second inner diameter <NUM>. The first inner diameter <NUM> can be approximately the same as the second inner diameter <NUM> such that the first body <NUM> and the second body <NUM> can substantially align with each other. By way of example, the first inner diameter <NUM> of the first body can be approximately <NUM> millimeters and the second inner diameter <NUM> can be approximately <NUM> millimeters. Because the first body <NUM> and the second body <NUM> have substantially equal inner diameters <NUM>, <NUM>, the first body <NUM> can exert an outward force onto the second body <NUM> in the clot engaging configuration.

<FIG> illustrate the first body <NUM> and the second body <NUM> in a first position. The first plurality of struts <NUM> can form a first plurality of scaffolding segments 138a having closed cells and the second plurality of struts <NUM> of the second body <NUM> can form a second plurality of scaffolding segments 138b also having closed cells. The first plurality of scaffolding segments 138a and the second plurality of scaffolding segments 138b can be substantially aligned with each other. A gap can be formed between each scaffolding segment of the first and second plurality of scaffolding segments 138a, 138b. Such gap can be a clot reception space <NUM> configured to receive a clot. Portions of the clot can enter such clot reception spaces <NUM>, thereby being captured by the clot retrieval device <NUM>, upon the first body <NUM> moving from the first position to a second position in relation to the second body <NUM> as further discussed herein.

A distal end of the first body <NUM> and the second body <NUM> can form a distal basket <NUM>. The distal basket <NUM> can have a substantially conical shape and can mitigate and/or prevent captured fragments of a clot from migrating out of the clot retrieval device <NUM>.

As further illustrated in <FIG>, a proximal end of the clot retrieval device <NUM> can include a shaft <NUM> including a pull wire <NUM> surrounded by an outer sheath <NUM>. Proximal struts of the first plurality of struts <NUM> can be affixed to the pull wire <NUM>, as illustrated in <FIG>. The pull wire <NUM> can be made of stainless steel, MP35N, Nitinol, or other material of suitably high modulus and tensile strength. The pull wire <NUM> can preferably have a solid core but can also have a hollow core. The first plurality of struts <NUM> of the first body <NUM> can be affixed to the pull wire <NUM> at a joint <NUM> via welding, bonding, by virtue of being cut from a contiguous tube, or other means of attachment. The joint <NUM> can be created at the approximate location of attachment of the proximal struts of the first plurality of struts <NUM> and the pull wire <NUM>. Such joint <NUM> can inhibit unintended movement beyond a desired position when the first body <NUM> moves in relation to the second body <NUM> as further discussed herein. The second plurality of struts <NUM> of the second body <NUM> can be joined to the outer sheath <NUM>, via welding, bonding, or the second body <NUM> can be formed using the same Nitinol or other material tubing of the outer sheath <NUM>. Because the first body <NUM> and the second body <NUM> are affixed to independent portions of the shaft <NUM> (e.g., the pull wire <NUM> and the outer sheath <NUM>, respectively), the first body <NUM> and the second body <NUM> can move independently of each other upon tension being applied to the pull wire <NUM> as further discussed herein.

<FIG> illustrates an expanded view of the substantially aligned first body <NUM> and the second body <NUM> and including an optional radially extending strut <NUM> and eyelet <NUM> to inhibit range of sliding movement between the first body <NUM> and the second body <NUM>. As illustrated, the second body <NUM> can radially surround the first body <NUM> such that the second plurality of struts <NUM> are exterior to the first plurality of struts <NUM>. The second plurality of struts <NUM> can further include one or more eyelets <NUM>, and the first plurality of struts <NUM> can include one or more radially extending "connector" struts each extending through a respective eyelet <NUM>. Each eyelet <NUM> can have an elongated or alternatively shaped opening. By way of example, the eyelet <NUM> can be substantially ovular, circular, rectangular, or the like. In some example, the eyelet <NUM> can be substantially tapered.

<FIG> illustrate side views of the clot retrieval device <NUM> in a clot pinching configuration in which the first body <NUM> moves (e.g., slides) from the first position as illustrated in <FIG> to a second position in relation to the second body <NUM>. The pull wire <NUM> can be pulled in the proximal direction to apply tension. The tension can cause the first body <NUM> to move from the first position (<FIG>) to the second position (<FIG>) in relation to the second body <NUM>. Accordingly, the first body <NUM> can slide from the first position to the second position in relation to the second body <NUM> such that the first body <NUM> and the second body <NUM> become engaged with one another. For example, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. When the first body <NUM> moves from the first position to the second position and the device <NUM> includes one or more radially extending struts <NUM> through respective eyelets <NUM> as illustrated in <FIG>, the radially extending struts <NUM> can engage with the eyelets <NUM>, thereby allowing the first body <NUM> and the second body <NUM> to become engaged with one another. Further, the eyelet <NUM> can inhibit the first body <NUM> from moving, in relation to the second body <NUM>, beyond the second position, as the eyelet <NUM> can restrict the radially extending strut <NUM> from moving too far in the proximal direction.

Additionally, or alternatively, the first expandable framework <NUM> and the second expandable framework <NUM> can be coated with a polymer coating (e.g., parylene) to temporarily hold the first body <NUM> in the first position in relation to the second body <NUM>. Upon the pull wire <NUM> being pulled in the proximal direction, the polymer coating can fail such that the first body <NUM> can move from the first position to the second position in relation to the second body <NUM>. Aspiration can be applied in order to remove particulate from the failed polymer coating.

Additionally, or alternatively, a shape memory effect of the first body <NUM> and the second body <NUM> can be used to cause automatic displacement of the first body <NUM> after a predetermined time period has lapsed. For example, the second plurality of struts <NUM> of the second expandable framework <NUM> can be heat treated locally to increase the austenite finish temperature to a range greater than a typical body temperature during a stroke or other critical body occurrence. The second plurality of struts <NUM> can expand upon being re-sheathed then be heated to the austenite finish temperature by electrical current. Upon the austenite finish temperature being reached, the first body <NUM> can automatic move (e.g., slide) in relation to the second body <NUM> from the first position to the second position, such that the clot can be pinched between the first body <NUM> and the second body <NUM>.

The pull wire <NUM> can be pulled in the proximal direction such that the first body <NUM> moves (e.g., slides) in the proximal direction until the proximal struts of the first plurality of struts <NUM> encounter the joint <NUM> positioned proximate the shaft <NUM>. As such, the joint <NUM> can act as a mechanism to prevent undesired movement beyond the second position. As the first body <NUM> moves from the first position to the second position the average cross-sectional area of the plurality of clot reception spaces <NUM> can decrease (e.g., at least partially close). For example, the plurality of clot reception spaces <NUM> can at least partially close when the first plurality of scaffolding segments 138a slide in relation to the second plurality of scaffolding segments 138b such that the first plurality of scaffolding segment 138a become disposed across the clot reception spaces <NUM>. Thereby, the clot can be pinched between the first body <NUM> and the second body <NUM>. Pinching of the clot can prevent the clot from migrating out of the clot retrieval device <NUM>, particularly upon retraction of the clot retrieval device <NUM>, as the pinch can increase the grip of the clot retrieval device <NUM> as compared to other clot retrieval devices, particularly fibrin rich clots. Accordingly, the clot retrieval device <NUM> can ensure effective and efficient removal of the clot from the patient.

As illustrated in <FIG>, the clot retrieval device <NUM> can include a polymer membrane <NUM> disposed between the first body <NUM> and the second body <NUM>. The polymer membrane <NUM> (e.g., elastic membrane) can be configured to transition from a folded configuration when the first body <NUM> is in the first position such that the first body <NUM> and the second body <NUM> are disengaged to a stretched configuration upon the first body <NUM> moving from the first position to the second position. The polymer membrane <NUM> can thereby function to limit lateral movement of the first body <NUM> in relation to the second body <NUM> in addition to, or as an alternative to the radially extending strut <NUM> and eyelet <NUM> illustrated in <FIG>. The polymer membrane <NUM> can be formed by threading microfibers through the eyelets <NUM> of the second body <NUM>, and/or the polymer membrane <NUM> can be formed by hooking the polymer membrane <NUM> into the eyelets <NUM>. The polymer membrane <NUM> can prevent the clot from migrating out of the clot retrieval device <NUM> once the clot has been pinched between the first body <NUM> and the second body <NUM>. Although <FIG> illustrate the polymer membrane <NUM> in one location, it is contemplated that the clot retrieval device <NUM> can include additional polymer membranes <NUM> over multiple locations. For example, the clot retrieval device <NUM> can include a first polymer membrane proximate the distal basket of the <NUM> and a second polymer membrane proximate the shaft <NUM>.

<FIG> illustrates an additional example clot retrieval device <NUM>. As discussed above with reference to the clot retrieval device <NUM> illustrated in <FIG>, the clot retrieval device <NUM> can similarly include the first expandable framework <NUM> including a first plurality of struts <NUM> and a second expandable framework <NUM> including a second plurality of struts <NUM>. Upon the clot retrieval device <NUM> being deployed from a restraining sheath (e.g., microcatheter) and transitioning from a constrained delivery configuration to a clot engaging configuration, the first plurality of struts <NUM> of the first expandable framework <NUM> can self-expand to form the first body <NUM> and the second plurality of struts <NUM> of the second expandable framework <NUM> can self-expand to form the second body <NUM>. The first body <NUM> and the second body <NUM> can be substantially cylindrical. Additionally, the first body <NUM> and the second body <NUM> can have substantially equal inner diameters <NUM>, <NUM>. As such, and as discussed above, the plurality of scaffolding sections 138a, 138b of the first body <NUM> and the second body <NUM> can be substantially aligned with one another.

In contrast to the clot retrieval device <NUM> illustrated in <FIG>, the clot retrieval device <NUM> can further include a third expandable framework <NUM> having a third plurality of struts <NUM>. Upon the clot retrieval device <NUM> being deployed from the restraining sheath, the third plurality of struts <NUM> of the third expandable framework <NUM> can self-expand to form a third body <NUM>. The third body <NUM> can be substantially porous. Further, the third body <NUM> can similarly be substantially cylindrical and can have an inner diameter <NUM> that is less than the inner diameter <NUM> of the first body <NUM> and the inner diameter <NUM> second body <NUM>. Thereby, the first body <NUM> and the second body <NUM> can radially surround the third body <NUM>. Optionally, the third body <NUM> can have an inner diameter <NUM> that is approximately half (½) the size of the inner diameter <NUM> of the first body <NUM> and inner diameter <NUM> of the second body <NUM>. Optionally, the third body <NUM> can have an inner diameter <NUM> that is approximately three quarters (¾) the size of the inner diameter <NUM> of the first body <NUM> and the inner diameter <NUM> of the second body <NUM>. The third expandable framework <NUM> can be preferably made from a material capable of recovering its shape automatically once released from a constricted delivery configuration. A super-elastic or pseudo-elastic material such as Nitinol or an alloy of similar properties is particularly suitable. The material can have a high recoverable strain sufficient to resiliently collapse and expand as described herein. The material could be in many forms such as wire or strip or sheet or tube. A particularly suitable manufacturing process is to laser cut a Nitinol tube and then heat set and electropolish the resultant structure to create a framework of struts and connecting elements. Optionally, the third expandable framework <NUM> can be laser cut from a Nitinol tube.

As discussed above with reference to the clot retrieval device <NUM>, the first body <NUM> can include a first plurality of scaffolding segments 138a and the second body <NUM> can include a second plurality of scaffolding segments 138b. The first and second plurality of scaffolding segments 138a, 138b can substantially align with one another. A gap can be formed between each scaffolding segment of the first plurality and second plurality of scaffolding segments 138a, 138b. Such gap can be a clot reception space <NUM> configured to receive at least a portion of a clot upon the clot retrieval device <NUM> transitioning to a clot pinching configuration as further described herein. The configuration of the third body <NUM> can similarly create additional clot reception spaces <NUM> as further discussed herein.

The distal end of the clot retrieval device <NUM> can include the distal basket <NUM>. The distal basket <NUM> can have a substantially conical shape and can mitigate captured fragments of a clot from migrating out of the clot retrieval device <NUM>.

As further illustrated in <FIG>, a plurality of expanded struts 208a, 208b can be formed from the shaft <NUM> of the first body <NUM>. For example, the shaft <NUM> of the first body <NUM> can be a tube (e.g., Nitinol tube) and the two expanded struts 208a, 208b can be formed (e.g., laser cut) from such tube. The shaft <NUM> of the first body <NUM> can be a hollow tube sized to receive the pull wire <NUM>. As such, the pull wire <NUM> can extend through the shaft <NUM> of the first body <NUM>. The plurality of expanded struts 208a, 208b can facilitate improved pinching when the clot retrieval device <NUM> transitions to the clot pinching configuration. Optionally, the plurality of expanded struts 208a, 208b can be used to allow re-expansion of the third body <NUM> to stabilize the clot if an effective pinch is not formed upon the clot retrieval device <NUM> transitioning to the clot pinching configuration. A shaft <NUM> of the second body <NUM> can surround the shaft <NUM> of the first body <NUM> and the pull wire <NUM>. The shaft <NUM> of the second body <NUM> can be a tube (e.g., a Nitinol tube). Proximal struts <NUM> of the second body <NUM> can extend from a distal end of the shaft <NUM> of the second body <NUM>. The proximal struts <NUM> can be the most proximal struts of the second expandable framework <NUM>. A proximal end of a shaft <NUM> of the third body <NUM> can be affixed to a distal end of the pull wire <NUM>. The shaft <NUM> of the third body <NUM> can be a solid core tube. A joint <NUM> (e.g. weld joint) can be formed where the shaft <NUM> of the third body <NUM> is affixed to the pull wire <NUM> and where the shaft <NUM> of the first body <NUM> forms the expanded struts 208a, 208b. Proximal struts <NUM> of the third body <NUM> can extend from a distal end of the shaft <NUM> of the third body <NUM>. The proximal struts <NUM> can be the most proximal struts of the third expandable framework <NUM>.

<FIG> illustrate various configurations of the third body <NUM>. In <FIG>, the third plurality of struts <NUM> can be configured to form a substantially cylindrical body of interconnected struts. The third plurality of struts <NUM> can be interconnected with one another such that the third plurality of struts form a majority of closed cells. The third plurality of struts <NUM> can be configured to form closed cells of differing sizes. Optionally, the closed cells can be sized according to the content of the clot to be captured (e.g., based on how soft and/or fibrin rich the clot to be captured is). As illustrated in <FIG>, the third body <NUM> can further include a plurality of clot reception spaces <NUM>. The size of each clot reception space <NUM> can be based on the configuration of the third plurality of struts <NUM>. Optionally, as illustrated in <FIG>, the third plurality of struts <NUM> can include at least one disconnected strut 204a. The disconnected strut can form an open cell. Such open cell can form a larger clot reception space <NUM>, and thereby facilitate migration of the clot into the third body <NUM>. Optionally, the third plurality of struts <NUM> can include a plurality of disconnected struts 204a such that a majority of the cells are open cells. The third body <NUM> can serve two primary functions. For example, the third body <NUM> can facilitate allowing blood to pass through so that there is at least partial blood flow through the blood vessel as a clot is being captured and withdrawn by the clot retrieval device <NUM>. Additionally, upon the clot retrieval device <NUM> being deployed, a clot can become partially integrated into the clot reception spaces <NUM> of the first body <NUM> and the second body <NUM>. Upon the third body <NUM> moving (e.g., sliding) in relation to the first body <NUM> and the second body <NUM>, the third body <NUM> can interact with the clot, thereby promoting further integration of the clot between the first body <NUM> and the second body <NUM> prior to forming a pinch.

<FIG> illustrates an additional side view of the clot retrieval device <NUM>. As illustrated in <FIG>, the first body <NUM> can include a first collar <NUM>, the second body <NUM> can include a second collar <NUM>, and the third body <NUM> can include a third collar <NUM>. Each collar <NUM>, <NUM>, <NUM> can facilitate moving (e.g., sliding) the third body <NUM> in relation to the first body <NUM> and the second body <NUM> and subsequently moving (e.g., sliding) the first body <NUM> in relation to the second body <NUM> to pinch at least a portion of a clot. The pull wire <NUM> can be affixed to the third body <NUM> and can be threaded through each collar <NUM>, <NUM>, <NUM> such that upon the pull wire <NUM> being pulled in the proximal direction, the clot retrieval device <NUM> can move (e.g., slide) from a first position to a second position and subsequently from a second position to a third position.

<FIG> illustrates an example third collar <NUM>. The third collar <NUM> can be disposed where the expanded struts 208a, 208b conjoin. The third collar <NUM> can be laser cut in a particular design to facilitate pinching the clot upon the clot retrieval device <NUM> moving from the first position to the second position and subsequently from the second position to the third position.

In order to pinch the clot using the clot retrieval device <NUM>, the pull wire <NUM> can be pulled in a proximal direction. Such tension can cause the third body <NUM> to move (e.g., slide) in relation to the first body <NUM> and the second body <NUM> causing the clot retrieval device <NUM> to transition from the first position to the second position, as indicated by a first arrow <NUM>. For example, the third body <NUM> can slide less than approximately <NUM> millimeters in relation to the first body <NUM> and the second body <NUM>. Optionally, the third body <NUM> can slide less than approximately <NUM> millimeters in relation to the first body <NUM> and the second body <NUM>. Optionally, the third body <NUM> can slide less than approximately <NUM> millimeters in relation to the first body <NUM> and the second body <NUM>. Optionally, the third body <NUM> can slide less than approximately <NUM> millimeters in relation to the first body and the second body <NUM>.

Upon the third body <NUM> moving in relation to the first body <NUM> and the second body <NUM>, at least a portion of the clot can be pinched between the third body <NUM> and the first body <NUM> and the second body <NUM> to cause the portions of the clot to migrate inside the first body <NUM> and the second body <NUM>. Additionally, upon the third body <NUM> moving from the first position to the second position, the third body <NUM> can become engaged with the first body <NUM> as the third collar <NUM> becomes engaged with the first collar <NUM>. When the third collar <NUM> and the first collar <NUM> become engaged, the pull force can be transferred to the first body <NUM>, thereby allowing for further displacement.

Subsequently, the first body <NUM> can move (e.g., slide) in relation to the second body <NUM> such that the clot retrieval device <NUM> transitions from the second position to the third position, as indicated by a second arrow <NUM>. For example, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>. Optionally, the first body <NUM> can slide less than approximately <NUM> millimeters in relation to the second body <NUM>.

Upon the first body <NUM> moving from the second position to the third position, the first body <NUM> engaged with the third body <NUM> can become engaged with the second body <NUM> causing an average cross-sectional area of the plurality of clot reception spaces <NUM> to decrease (e.g., at least partially close). Thereby, at least a portion of the clot can be further pinched. The portions of the clot can be pinched between the first body <NUM> and the second body <NUM> and, additionally, the third body <NUM>. Accordingly, the portions of the clot can further migrate inside third body <NUM>. As such, the portions of the clot can further migrate into the clot reception spaces <NUM> of the third body <NUM>. Upon transitioning to the third position, the expanded struts 208a, 208b can become resheathed as the first collar <NUM> becomes engaged with the second collar <NUM>. When the first collar <NUM> becomes engaged with the second collar <NUM>, the pull force can be transferred to the second body <NUM>. Accordingly, the first body <NUM>, the second body <NUM>, and the third body <NUM>, including the captured clot or portions thereof, can be removed simultaneously from the patient's vasculature.

Optionally, the clot retrieval device <NUM> can include a seal that allows the clot retrieval device <NUM> to maintain a pinch even if the physician stops applying tension. For example, the clot retrieval device <NUM> can include a seal disposed proximate the weld joint <NUM>. The seal can maintain the clot retrieval device <NUM> in place using friction. As such, the seal can create enough static friction such that the clot removal device <NUM> does not displace when a physician stops applying tension while also ensuring the static friction is not too high that a user cannot overcome such static friction when manipulating the clot retrieval device <NUM> during retrieval of the clot and removal of the clot retrieval device <NUM> from a patient.

<FIG> illustrate an additional example clot retrieval device <NUM>. The clot retrieval device <NUM> can have a constrained delivery configuration and a clot engaging configuration and can be configured to remove a clot (e.g., thrombus) T from a blood vessel. The clot removal device <NUM> can be in the constrained delivery configuration when the clot removal device <NUM> is positioned within a restraining sheath (e.g., microcatheter). Upon the restraining sheath being retracted, the clot removal device <NUM> can transition to the clot engaging configuration. The clot retrieval device <NUM> can include an inner expandable framework <NUM> and an outer expandable framework <NUM>. The inner expandable framework <NUM> can include an inner plurality of struts <NUM> that self-expand to form an inner body <NUM> upon the clot retrieval device <NUM> transitioning from the constrained delivery configuration to the clot engaging configuration. Similarly, the outer expandable framework <NUM> can include an outer plurality of struts <NUM> that self-expand form an outer body <NUM> upon the clot retrieval device <NUM> transitioning from the constrained delivery configuration to the clot engaging configuration. The inner expandable framework <NUM> and the outer expandable framework <NUM> can be preferably made from a material capable of recovering its shape automatically once released from a constricted delivery configuration and further include the additional characteristics as described above with reference to the first expandable framework <NUM> and the second expandable framework <NUM>.

The inner body <NUM> and the outer body <NUM> can have different inner diameters <NUM>, <NUM> and/or configurations. For example, the inner body <NUM> can have a smaller inner diameter <NUM> than the inner diameter <NUM> of the outer body <NUM>, as such the outer body <NUM> can radially surround the inner body <NUM>. Optionally, the inner diameter <NUM> of the inner body <NUM> can be approximately half of the size of the inner diameter <NUM> of the outer body <NUM>. Optionally, the inner diameter <NUM> of the inner body <NUM> can be approximately ¾ of the size of the inner diameter <NUM> of the outer body <NUM>. As illustrated in <FIG>, the differing diameters <NUM>, <NUM> and shape configurations of the inner body <NUM> and the outer body <NUM> can form a plurality of clot reception spaces <NUM> configured to engage with a clot T. For example, the outer body <NUM> can include a plurality of scaffolding sections. A clot reception space <NUM> can be formed between each scaffolding section <NUM> of the plurality of scaffolding sections. Additionally, the inner body <NUM> can have a substantially "S" wave shape. Such "S" wave shape can facilitate pinching and capturing the clot upon the inner body <NUM> moving in relation to the outer body <NUM>, and upon capturing the clot, preventing the captured clot from migrating out of the clot retrieval device <NUM>.

The inner body <NUM> and the outer body <NUM> can each be affixed to a pull wire <NUM>. The pull wire <NUM> can include a first stopper <NUM> and a second stopper <NUM> at a proximal end <NUM> of the pull wire. The first stopper <NUM> can be disposed distally in relation to the second stopper <NUM>.

A spring <NUM> can be affixed to a distal end <NUM> of the pull wire <NUM>. The spring <NUM> can be configured to transition from a compressed configuration and an elongated configuration upon actuation. The spring <NUM> can be configured to maintain a central position of the inner body <NUM> within the outer body <NUM>. In the previously illustrated clot retrieval devices <NUM>, <NUM> because the first body <NUM> has an approximately equal inner diameter <NUM> to the second body <NUM>, the first body <NUM> resides centrally within the second body <NUM> because of outward force from the first body <NUM> onto the second body <NUM>. When the inner body <NUM> has a substantially smaller inner diameter <NUM> than the outer body <NUM> as illustrated in <FIG>, a distal portion of the inner body <NUM> can radially deflect with respect to the outer body <NUM> but for the spring <NUM> which inhibits the distal portion from deflecting. The spring <NUM> can further function to hold the device <NUM> in a first position when the pull wire <NUM> is not under tension.

As illustrated in <FIG>, the clot retrieval device <NUM> can be positioned proximate to the clot T. At least a portion of the clot retrieval device <NUM> can traverse the clot T such that a distal end of the clot retrieval device <NUM> can be forward in relation to the clot T. The pull wire <NUM> can be pulled in a proximal direction causing the inner body <NUM> to move (e.g., slide) from the first position to the second position in relation to the outer body <NUM>.

<FIG> illustrates the clot retrieval device <NUM> transitioning to a clot pinching configuration upon the inner body <NUM> moving from the first position to the second position. The pull wire <NUM> can be pulled in the proximal direction until the first stopper <NUM> is proximate and/or engages (e.g., touches or becomes within a predetermined distance of the second stopper <NUM>) the second stopper <NUM>, as such the second stopper <NUM> can serve as an indicator of when to stop applying tension to the pull wire <NUM> and/or gradually weaken the amount of tension being applied to the pull wire <NUM>. When the pull wire <NUM> is pulled in the proximal direction, the spring <NUM> can be actuated, causing the spring <NUM> to transition from the compressed configuration to the elongated configuration. When the spring <NUM> transitions to the elongated configuration, the inner body <NUM> can move from the first position to the second position. Such movement from the first position to the second position can cause the average cross-sectional area of the clot reception spaces <NUM> to decrease (e.g., at least partially close), thereby pinching the clot T between the inner body <NUM> and the outer body <NUM>. Upon pinching the clot T between the inner body <NUM> and outer body <NUM>, the inner body <NUM> and the outer body <NUM>, including the clot T, can be retracted into the restraining sheath (e.g., microcatheter), and subsequently the clot retrieval device <NUM> can be removed from the patient.

<FIG> illustrates a flow diagram outlining a method <NUM> of capturing a clot using the clot retrieval device <NUM> illustrated in <FIG>. The method <NUM> can include deploying <NUM> the clot retrieval device <NUM> proximate to the clot. As discussed herein, the clot retrieval device <NUM> can include a first expandable framework <NUM> and a second expandable framework <NUM>. Upon deploying the clot retrieval device <NUM>, the clot retrieval device <NUM> can transition from a constrained delivery configuration to a clot engaging configuration and the first expandable framework <NUM> can expand to form a first body <NUM> while the second expandable framework <NUM> can expand to form a second body <NUM> that radially surrounds the first body <NUM>. The first body <NUM> and the second body <NUM> can have substantially the same inner diameter <NUM>. <NUM>, such that the first body <NUM> and the second body <NUM> substantially radially align with one another.

The method <NUM> can further include moving <NUM> (e.g., sliding) the first body <NUM> proximally in relation to the second body <NUM> to pinch at least a portion of the clot between the first body <NUM> and the second body <NUM> such that the clot removal device <NUM> transitions to a clot pinching configuration. By way of example, tension can be applied to the pull wire <NUM> until the first body <NUM> encounters the joint <NUM>. As the pull wire <NUM> is pulled in the proximal direction, the first body <NUM> can move in the proximal direction in relation to the second body <NUM>, thereby pinching at least a portion of the clot between the first body <NUM> and the second body <NUM>.

The method <NUM> can further include capturing <NUM> one or more fragments of the clot.

Additionally, the method <NUM> can include retracting the first body <NUM> and the second body <NUM> simultaneously, as the first body <NUM> and the second body <NUM> become engaged upon the first body <NUM> moving in relation to the second body <NUM>. Similarly, upon the first body <NUM> and the second body <NUM> being retracted into a restraining sheath, the restraining sheath can be removed from a patient's vasculature.

<FIG> illustrates a flow diagram outlining a method <NUM> of capturing a clot using the clot retrieval device <NUM> illustrated in <FIG>. The method <NUM> can include deploying <NUM> the clot retrieval device <NUM> proximate to the clot. As discussed herein, the clot retrieval device <NUM> can include a first expandable framework <NUM>, a second expandable framework <NUM>, and a third expandable framework <NUM>. Upon deploying the clot retrieval device <NUM>, the clot retrieval device <NUM> can transition from a constrained delivery configuration to a clot engaging configuration and the first expandable framework <NUM> can expand to form a first body <NUM> while the second expandable framework <NUM> can expand to form a second body <NUM> that radially surrounds the first body <NUM>. The first body <NUM> and the second body <NUM> can have substantially the same inner diameter <NUM>. <NUM>, such that the first body <NUM> and the second body <NUM> can substantially align with each other. Similarly, the third expandable framework <NUM> can expand to form the third body <NUM>. The first body <NUM> and the second body <NUM> can radially surround the third body <NUM>, as the third body <NUM> can have a smaller inner diameter <NUM> as compared to the first body <NUM> and the second body <NUM>.

The method <NUM> can further include moving <NUM> (e.g., sliding) the third body <NUM> in relation to the first body <NUM> and the second body <NUM> to pinch at least a portion of the clot between the third body <NUM> and the first body <NUM> and the second body <NUM> such that the clot removal device <NUM> transitions to a clot pinching configuration. As such, at least a portion of the clot can migrate into the first body <NUM> and the second body <NUM>. Upon moving the third body <NUM> in relation to the first body <NUM> and the second body <NUM>, the third body <NUM> can become engaged with the first body <NUM>.

The method <NUM> can further include moving <NUM> (e.g., sliding) the first body <NUM> proximally in relation to the second body <NUM> to further pinch at least a portion of the clot between the third body <NUM> and the first body <NUM> and the second body <NUM>. As the first body <NUM> moves in relation to the second body <NUM>, the average cross-sectional area of the clot reception spaces <NUM> can decrease, thereby pinching at least a portion of clot and preventing and/or mitigating the captured portions of the clot from migrating back out of the clot retrieval device <NUM>. Upon pinching the clot, at least a portion of the clot can migrate inside the third body <NUM>. When at least a portion of the clot is within third body <NUM>, the potential for the portions of the captured clot to migrate back out of the clot retrieval device <NUM> can decrease.

Additionally, the method <NUM> can include simultaneously retracting the first body <NUM>, the second body <NUM>, and the third body <NUM>. Upon being retracted into a delivery microcatheter, the delivery microcatheter can be removed from a patient's vasculature, and thus, the clot can be removed effectively and efficiently from the patient's vasculature.

Claim 1:
A clot retrieval device (<NUM>) comprising a constrained delivery configuration and a clot engaging configuration and being configured to remove a clot from a blood vessel, the device comprising:
a first expandable framework (<NUM>) comprising a first plurality of struts (<NUM>) forming a first body (<NUM>); and
a second expandable framework (<NUM>) comprising a second plurality of struts (<NUM>) forming a second body (<NUM>) at least partially surrounding the first body,
wherein in the clot engaging configuration, the first body is configured to move from a first position to a second position in relation to the second body,
characterised in that the first plurality of struts comprises at least one radially extending strut (<NUM>) and the second plurality of struts comprises at least one eyelet (<NUM>) through which the at least one radially extending strut radially extends, the at least one eyelet and the at least one radially extending strut being configured such that when the first body moves from the first position to the second position, the at least one radially extending strut engages the at least one eyelet to inhibit the first plurality of struts from moving, in relation to the second plurality of struts, beyond the second position.