Method and system for reducing limb ischemia

Abstract

Devices and methods are provided for minimizing and / or preventing limb ischemia, such as when a medical device inserted into a patient's vasculature obstructs a blood vessel. The device may include a tubular member and one or more expandable features having a metal wire disposed about the tubular member, the one or more wires disposed about the tubular member configured to expand at a target site, thereby allowing blood to surround and flow through any possibly occluded medical device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. 63 / 340,344, filed May 10, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to methods, devices, and systems for preventing and / or reducing limb ischemia, such as limb ischemia resulting from the use of a mechanical circulatory support device. Background Art

[0004] Limb ischemia is a rapid and sudden decrease in limb perfusion, often threatening the vitality of the limb. It may occur due to blood obstruction caused by indwelling sheaths and / or catheters, partial occlusions (e.g., atherosclerotic stenosis), and / or continuous occlusions caused by small vessels and / or large sheaths. It may also occur due to closure problems.

[0005] Limb ischemia is associated with mortality, and some literature suggests that the rate of limb ischemia may be high. Therefore, in addition to the negative impact on patients, it may also have a negative impact on ongoing clinical trials. Summary of the invention

[0006] In various aspects, a device may be provided. The device may include a first tubular member. The device may include a radially expandable feature having one or more wires disposed about the first tubular member, the radially expandable feature being configured to selectively expand from a first configuration to a second configuration to allow blood within a patient's vessel to flow from a point upstream of the radially expandable feature around the first tubular member, around and / or through the one or more radially expandable features, and to a point downstream of the radially expandable feature.

[0007] The one or more metal wires may form a cylindrical wire mesh around the first tubular member. The wire mesh may have a first configuration. The first configuration may have an outer diameter of no more than 12 Fr. The wire mesh may have a second configuration. The second configuration may have an outer diameter of no less than 20 Fr. The wire mesh may be configured to have a controllable outer diameter and may be 7 Fr to 23 Fr. When compressed in the second configuration, the wire mesh may increase its outer diameter and reduce its axial length. When in tension in the first configuration, the wire mesh may reduce its outer diameter and increase its axial length.

[0008] The one or more wires may form a stent around the first tubular member; that is, the stent may be a radially expandable feature. The one or more wires form a wire basket around the first tubular member.

[0009] The one or more wires may be configured to extend radially outwardly away from the first tubular member to dilate a portion of a blood vessel.

[0010] The device may include a second tubular member, wherein the first tubular member may be slidably received by the second tubular member. The one or more metal wires may be coupled to the first tubular member. The one or more metal wires may be coupled to the second tubular member. In some embodiments, the distal end of the second tubular member may be configured to contact the proximal end of the one or more wires, such that compression of the one or more wires may require moving the second tubular member in a distal direction. In some embodiments, the distal end of the second tubular member may be configured to contact the distal end of the one or more wires, such that compression of the one or more wires may require moving the second tubular member in a proximal direction. The distal end of the second tubular member may have one or more protrusions. The one or more protrusions may have at least one surface configured to contact the distal end of the one or more wires.

[0011] In various aspects, methods for reducing the risk of limb ischemia may be provided. The method may include inserting a device as disclosed herein into a blood vessel, such as an artery. The method may include expanding the blood vessel at a location by expanding an expandable feature to a second configuration. The method may include allowing blood to pass from a location upstream of one or more wires through one or more wires to a location downstream of one or more wires. The method may include returning the expandable feature to a first configuration. The method may include removing the device from the blood vessel.

[0012] In some embodiments, the method may include inserting a cannula through the first tubular member before the device has been inserted into the blood vessel. In some embodiments, the method may include inserting a mechanical circulatory support device through the first tubular member after the device has been inserted into the blood vessel.

[0013] The method may include sliding a second tubular member over the first tubular member. The distal end of the second tubular member may contact the proximal end of the one or more wires, and the method may include compressing the one or more wires by moving the second tubular member in a distal direction. The distal end of the second tubular member may contact the distal end of the one or more wires, and the method may include compressing the one or more wires by moving the second tubular member in a proximal direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

[0015] Figure 1A and1B Illustration of a device comprising expandable features in a first configuration (1A) and a second configuration (1B).

[0016] Figure 2A is an illustration of an expandable feature having one or more wires in a first configuration.

[0017] Figure 2B and 2C is an illustration of an expandable feature having one or more wires in a second, different configuration.

[0018] Figure 3-5 are illustrations of various embodiments of the apparatus.

[0019] Figure 6 is an illustration of the device in a second configuration within a blood vessel.

[0020] Figure 7 is a diagram of the device inside a patient.

[0021] Figure 8 is a flow chart of the method. DETAILED DESCRIPTION

[0022] The following description and accompanying drawings illustrate the principles of the present invention only. Therefore, it should be understood that those skilled in the art will be able to design various arrangements that, although not explicitly described or shown herein, embody the principles of the present invention and are included within the scope thereof. In addition, all examples described herein are primarily intended to be used for illustrative purposes only to help the reader understand the principles of the present invention and the concepts contributed by the inventors to promote the art, and should be interpreted as not being limited to these specifically described examples and conditions. In addition, the term "or", as used herein, refers to a non-exclusive "or", unless otherwise specified (e.g., "or other" or "or alternative"). In addition, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments may be combined with one or more other embodiments to form new embodiments.

[0023] Many innovative teachings of the present application will be described with particular reference to currently preferred exemplary embodiments. However, it should be understood that such embodiments only provide several examples of many advantageous uses of the innovative teachings herein. Generally, the statements made in the specification of the present application do not necessarily limit the various claimed inventions. In addition, some statements may apply to some creative features, but not to other features. Those skilled in the art and those skilled in the art who are informed by the teachings herein will recognize that the present invention is also applicable to various other technical fields or embodiments.

[0024] As is well known, limb ischemia is a rapid and sudden decrease in perfusion to a patient's limb, which may occur due to blood obstruction caused by indwelling sheaths and / or catheters, partial occlusions (e.g., atherosclerotic stenosis), and / or continuous occlusions of small vessels and / or large sheaths. Limb ischemia may also occur due to closure devices.

[0025] In some cases, to address limb ischemia, a small diameter catheter may be inserted distally to provide antegrade flow to the ischemic limb. For example, the catheter may be inserted into the dorsalis pedis artery or the posterior tibial artery. It will be appreciated that antegrade flow may be introduced at any appropriate time (e.g., at the time of initial ECMO (extracorporeal membrane oxygenation) cannulation or implantation of a mechanical circulatory support device, or at a later time, such as after local ischemia is discovered). In some cases, this conventional solution may not be available to all patients. For example, some patients may not have a dorsalis pedis artery or posterior tibial artery large enough to introduce a catheter.

[0026] The inventors have recognized that when ischemic events are quickly identified and resolved, patient outcomes can be improved. The inventors have also recognized that, for example, by a device (e.g., an arterial ECMO cannula or an introducer sheath), by expanding the vasculature around at least a portion of the device (e.g., an introducer sheath), the benefits of distal limb perfusion in patients with potentially occluded arteries are promoted and provided. For example, as described herein, by expanding the vasculature around at least a portion of a fully introduced cannula, blood flow (e.g., retrograde) can be allowed to bypass the cannula. In this regard, the disclosed devices and methods can address the unmet needs of currently existing distal limb perfusion technologies. The disclosed devices and methods can also reduce the number of insertion sites in a patient's body, which can reduce the risk of infection, sepsis, bleeding, hematoma, ischemia, and / or pseudoaneurysm.

[0027] In various aspects, devices and methods can be provided for promoting and improving distal limb perfusion and reducing limb ischemia. Figure 1A , the device 100 according to some embodiments may include a tubular member 110. The first tubular member may be, for example, a sheath, a cannula, a catheter, etc. The tubular member may include a lumen 112 extending therethrough (e.g., from a distal end to a proximal end). The tubular member may be constructed of any suitable material, such as nitinol, a medical grade polymer (such as polyurethane), a combination thereof, or other suitable material. As will be appreciated, one or more medical devices (e.g., a mechanical circulatory support device) may be passed through the lumen 112.

[0028] As described herein, the device can be used to expand the vasculature around the device. Thus, in some embodiments, the device can include an expandable feature disposed around at least a portion of the tubular member 110. In some embodiments, the expandable feature can include one or more wires 120 disposed around the first tubular member, such as at or near the distal end of the tubular member. In some embodiments, the one or more wires can form or be a part of an expandable wire mesh. In other embodiments, the one or more wires can form or be a part of an expandable stent. The wires can be nitinol, stainless steel, or other suitable material.

[0029] In some embodiments, the device may include an additional tubular member 130 , which may be configured to slidably receive the tubular member 110 .

[0030] As described herein, the expandable feature can have a first collapsed configuration (see Figure 1A ), for example, for when the tubular member is inserted into the vasculature of a patient. As shown, in this configuration, one or more wires of the expandable feature may have a relatively small outer diameter, only slightly larger than the outer diameter of the tubular member 110. In some embodiments, this may be the default configuration. In some embodiments, this configuration may exist when one or more wires of the expandable feature are in tension. In some embodiments, the first configuration may have an outer diameter of no more than 12 Fr, but it should be understood that other diameters may be used.

[0031] As will be appreciated, in addition to insertion, the first configuration is also useful when the device is repositioned in and / or removed from the blood vessel 10. In this regard, the expandable feature can move from a first (collapsed) configuration to a second (expanded) configuration and then back to the first configuration. In some embodiments, the blood vessel can be an artery, such as a femoral artery.

[0032] The expandable feature (e.g., one or more wires) may also have a second expanded configuration, such as Figure 1BAs shown, to expand the vasculature and establish a path for blood flow around the tubular member 110. In some embodiments, in the expanded configuration, one or more wires 120 can be axially compressed, resulting in one or more wires having an outer diameter 123 that is relatively larger (and larger than the tubular member 110) than in the first configuration. In the expanded configuration, one or more wires can also have an axial length 125 that is relatively shorter than the wires in the first configuration. In some embodiments, the expanded configuration can also be a default configuration, in which the feature can be compressed back to the compressed configuration. In some embodiments, this configuration can exist when one or more wires are compressed. The second configuration can have an outer diameter of not less than 20Fr. In some embodiments, the second configuration can have a controllable outer diameter, and the outer diameter can be adjusted to any specified diameter from its minimum diameter (e.g., 7Fr) to its maximum diameter (e.g., 23Fr).

[0033] As shown, one or more wires can be configured to extend radially outwardly away from the central axis 114 of the tubular member 110, away from the tubular member 110, and toward the blood vessel 10 to dilate a portion of the blood vessel.

[0034] Figure 2A An embodiment is shown in which the expandable feature comprises one or more wires forming a wire mesh. As shown in this view, the wire mesh 120 in a first collapsed configuration may have an outer diameter 122 and an axial length 124. Figure 2B In the expanded state, the wire mesh may increase its outer diameter 122 and decrease its axial length 124 when compressed. In some embodiments, the wire mesh may form a stent around the tubular member 110, whereby the one or more wires are pressed against the vessel and a majority of the blood is configured to flow through one or more ends of the wire mesh into a central lumen 128 defined by the one or more wires. Blood may also flow through the mesh. As will be appreciated, when again in a tensioned state, the wire mesh may decrease its outer diameter and increase its axial length, returning to a state of being compressed. Figure 2A The form seen in .

[0035] like Figure 2A and Figure 2B As shown, in each of the first configuration and the second configuration, the expandable feature can have a constant (or nearly constant) diameter. In other embodiments, the shape of the mesh (or stent) can vary between the distal end and the proximal end. For example,

[0036] refer to Figure 2C In some embodiments, when compressed, the wire mesh may have a distal portion 126 having a first outer diameter 122 and a more proximal portion 127 having a second outer diameter 123 that is greater than the first outer diameter.

[0037] In some embodiments, the wire mesh may form a wire basket around the tubular member 110 whereby blood enters the central lumen defined by the wire or wires by passing through gaps 129 between the wire or wires at locations distal from the ends of the wire mesh.

[0038] As will be appreciated, the wire can be used in a stent or wire basket having openings of any suitable shape. For example, in some embodiments, the openings can be diamond-shaped, square-shaped, triangular-shaped, other polygonal-shaped, or other suitable shapes. The wire can have any suitable thickness, but it should be understood that when the expandable feature is in the expanded configuration, the wire is strong enough to hold the blood vessel in the expanded position.

[0039] As disclosed herein, one or more wires 120 of an expandable feature can be coupled to the tubular member 110. For example, Figure 3 As shown, one or more metal wires can be connected at the distal end 161 of the one or more wires. The one or more wires can have one or more attachment points 140 to connect the expandable feature to the tubular member 110. In some embodiments, the attachment point can include a connector, glue, welding, or another suitable attachment point. Figure 4 In the embodiment, the one or more wires of the expandable feature may also be coupled to the one or more wires at the proximal end 162 at one or more attachment points 140. As described above, the same or different types of attachment points may be used at the distal end as those used at the proximal end.

[0040] The one or more wires 120 of the expandable feature may be coupled to an additional tubular member 130 , such as those described above with respect to tubular member 110 .

[0041] In some embodiments, the distal end 131 of the additional tubular member 130 may be configured to contact the proximal end 162 of one or more wires of the expandable feature such that compressing the one or more wires may require moving the second tubular member in the distal direction 150 .

[0042] In some embodiments, the distal end 131 of the additional tubular member 130 can be configured to contact the distal end 161 of the one or more wires such that compressing the one or more wires may require moving the additional tubular member in the proximal direction 152. As will be appreciated, in some embodiments, the additional tubular member 130 can be used as an actuator to move an expandable feature (e.g., a wire mesh) between a first configuration and a second configuration.

[0043] Reference Figure 5 In other embodiments, one or more wires of the expandable feature may not be coupled to the tubular member 110. Instead, the additional tubular member 130 may be configured to contact the distal end of the one or more wires, as described with respect to Figure 4In addition, the second additional tubular member 170 can be configured to contact the proximal end of the one or more wires so that when the additional tubular member 130 moves in the proximal direction 152, it presses the one or more wires against the second additional tubular member 170. Also in this regard, the additional tubular member can be used as an actuator to move the expandable feature between the first configuration and the second configuration.

[0044] In some embodiments, the distal end 131 of the additional tubular member 130 can have one or more protrusions 132 extending radially outward (e.g., away from the central axis of the tubular member 110). The one or more protrusions 132 can have at least one surface 134 configured to contact the distal end 161 of the one or more wires 120. As will be appreciated, other connectors can also be used in other embodiments.

[0045] like Figure 6 As shown, in some embodiments, the first tubular member 110 can be used to pass one or more medical devices, but it can also be used to allow blood to enter the patient's vascular system. In this regard, blood can flow through the first tubular member 110 in a first direction (see arrow 182), while blood in the blood vessel can flow through the one or more wires in the opposite direction (see arrow 180) from a position upstream of the one or more wires and to a position downstream of the one or more wires. In this way, distal perfusion can be achieved via blood flow in a second direction (arrow 180).

[0046] In view of the above, it should be understood that the expandable feature can be configured to move between a first configuration and a second configuration. In some embodiments, the expandable feature can be configured to automatically move between the first configuration and the second configuration, for example in response to received information (e.g., the occurrence or likelihood of an ischemic event). In some embodiments, it can be configured so that a clinician can selectively expand the expandable feature to an expandable state or return the expandable feature to a compressed state. Reference Figure 7, wherein the device 100 is shown as being placed within a blood vessel after passing through an insertion point 20 in the patient's skin 22, in some embodiments, the device may include one or more handles 700 operably coupled to the device. In such embodiments, the handle may be used to control the device, such as expanding the expandable feature (e.g., opening a wire mesh or stent around a tubular member) to create space in the vascular system and provide a path for blood around the tubular member. As will be understood, the handle may be operably coupled to the expandable feature. In some embodiments, the handle may actuate an additional tubular member (e.g., an actuator) to expand the expandable feature. In some embodiments, the handle may be rotated, which may cause an attached movement of the expandable feature. In some embodiments not shown, the handle may be connected to an expandable member (e.g., a balloon) disposed between the tubular member and the expandable feature, wherein the expandable member is configured to expand the wire to an expanded configuration. As will be understood, once expanded, the wire may be configured to maintain an expanded shape until used by a clinician.

[0047] In various aspects, methods are available to reduce the risk of limb ischemia. Figure 8 , method 800 may include inserting 810 a device as disclosed herein into a blood vessel, such as an artery. In some embodiments, the device may need to be inserted to an appropriate depth so that it will dilate the blood vessel, such as an artery, rather than the arteriotomy / insertion site.

[0048] The method may include dilating 820 a blood vessel at a location by dilating one or more wires from a first configuration to a second configuration.

[0049] For example, in some embodiments, in use, one or more wires may initially be wrapped around the outer diameter of the tubular member / sheath and may then expand, pressing against the wall of the arteriotomy and dilating the blood vessel, leaving a gap between the sheath and the blood vessel wall. In operation, the device may prevent the sheath from completely occluding the blood vessel and allow blood to flow around and through the sheath.

[0050] The method may include allowing 830 blood to pass through the one or more wires from a location upstream of the one or more wires to a location downstream of the one or more wires. The method may include restoring 840 the one or more wires to the first configuration.

[0051] The method may include removing 850 the device from the blood vessel, for example after the patient has been removed from a medical device (e.g., arterial ECMO support or mechanical circulatory support). In such embodiments, the wire of the expandable feature (in the first configuration) may be removed along with the tubular member (e.g., cannula). In other embodiments, the cannula may be removed first, leaving the expandable feature in place for later withdrawal by a physician.

[0052] In some embodiments, the method may include inserting 860 a cannula through a tubular member, such as tubular member 110, before the device has been inserted into a blood vessel. In some embodiments, the method may include inserting 865 a cannula through a tubular member after the device has been inserted into a blood vessel.

[0053] The method may include sliding 870 a second tubular member over the first tubular member. As disclosed herein, the distal end of the second tubular member may contact the proximal end of one or more wires, and the method may include compressing the one or more wires by moving the second tubular member in a distal direction. The distal end of the second tubular member may contact the distal end of the one or more wires, and the method may include compressing the one or more wires by moving the second tubular member in a proximal direction.

[0054] Embodiments of the present disclosure are described in detail with reference to the accompanying drawings, wherein the same reference numerals identify similar or identical elements. It should be understood that the disclosed embodiments are merely examples of the present disclosure, which may be implemented in various forms. Well-known functions or configurations are not described in detail to avoid obscuring the present disclosure with unnecessary details. Therefore, the specific structural and functional details disclosed herein should not be interpreted as restrictive, but only as the basis for the claims, and as a representative basis for teaching those skilled in the art to use the present disclosure in different ways in almost any appropriate detailed structure.

[0055] Although various embodiments incorporating the teachings of the present invention have been shown and described in detail herein, those skilled in the art can easily design embodiments that still incorporate many other variations of these teachings. Therefore, although the foregoing is directed to various embodiments of the present invention, other and further embodiments of the present invention may be designed without departing from the basic scope of the present invention.

Claims

1. A device comprising: a first tubular member; and A radially expandable feature having one or more wires disposed around the first tubular member, the radially expandable feature being configured to selectively expand from a first configuration to a second configuration to allow blood within a patient's blood vessel to flow from a point upstream of the radially expandable feature around the first tubular member, around and / or through the one or more radially expandable features, and to a point downstream of the radially expandable feature.

2. The device according to claim 1, wherein: The one or more metal wires form a cylindrical wire mesh surrounding the first tubular member.

3. The device according to claim 2, wherein: In a first configuration, the wire mesh has an outer diameter no greater than 12 Fr.

4. The device according to claim 1, wherein: In a second configuration, the wire mesh has an outer diameter of no less than 20 Fr.

5. The device according to claim 1, wherein: The wire mesh can be configured to have an outer diameter of 7 Fr to 23 Fr.

6. The device according to claim 1, wherein: When compressed in the second configuration, the wire mesh increases its outer diameter and decreases its axial length, and wherein when tensioned in the first configuration, the wire mesh decreases its outer diameter and increases its axial length.

7. The device according to claim 1, wherein: The one or more wires form a stent around the first tubular member.

8. The device according to claim 1, wherein: The one or more metal wires form a wire basket around the first tubular member.

9. The device according to claim 1, wherein: The one or more wires are configured to extend radially outward away from the first tubular member to dilate a portion of a blood vessel.

10. The device of claim 1, further comprising a second tubular member, the first tubular member being slidably received by the second tubular member.

11. The device according to claim 10, wherein: The one or more wires are coupled to the first tubular member.

12. The device according to claim 10, wherein: The one or more wires are coupled to the second tubular member.

13. The device according to claim 10, wherein: The distal end of the second tubular member is configured to contact the proximal end of the one or more wires such that compression of the one or more wires requires movement of the second tubular member in a distal direction.

14. The device according to claim 10, wherein: The distal end of the second tubular member is configured to contact the distal end of the one or more wires such that compression of the one or more wires requires movement of the second tubular member in a proximal direction.

15. The device according to claim 10, wherein: The distal end of the second tubular member has one or more protrusions having at least one surface configured to contact the distal ends of the one or more wires.

16. A method comprising: inserting the device according to claim 1 into a blood vessel; expanding the blood vessel at a location by expanding the expandable feature to the second configuration; and Blood is allowed to pass through the one or more wires from a location upstream of the one or more wires to a location downstream of the one or more wires.

17. The method according to claim 16, further comprising: returning the one or more threads to a first configuration; and The device is removed from the blood vessel.

18. The method according to claim 16, wherein: The blood vessel is an artery.

19. The method of claim 16, further comprising inserting a mechanical circulatory support device through the first tubular member after inserting the device into the blood vessel.

20. The method of claim 16, further comprising inserting a cannula through the first tubular member after the device has been inserted into the blood vessel.

21. The method of claim 16, further comprising sliding a second tubular member over the first tubular member.

22. The method according to claim 20, wherein: The distal end of the second tubular member contacts the proximal end of the one or more wires, and compressing the one or more wires requires moving the second tubular member in a distal direction.

23. The method according to claim 20, wherein: The distal end of the second tubular member contacts the distal end of the one or more wires, and compressing the one or more wires requires moving the second tubular member in a proximal direction.

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