Self-expanding medical device for advancement through the vasculature to an intravascular dilation site - Patents.com

Abstract

A self-expanding medical device for advancement through the vasculature to an expanded site within a blood vessel is disclosed. The device comprises a working portion and a connecting portion that can be connected to a pusher. The working portion provides an outward radial force at any diameter between and including the diameter of the compressed configuration and the diameter of the expanded configuration, and comprises a plurality of cell crowns comprising an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts. Each of the proximal cell struts extends distally from a common proximal end to a proximal end of a respective one of the two middle cell struts. Each of the distal cell struts extends proximally from a common distal end to a distal end of a respective one of the two middle cell struts. Each middle cell strut is more flexible than the distal and proximal cell struts from which it extends.

Description

[Technical field]

[0001] The present invention relates generally to the field of medical devices. In particular, the present invention relates to self-expandable medical devices for advancement through the vasculature to a site of dilation within a blood vessel. The present invention also provides methods of making and using such devices. [Background technology]

[0002] A wide variety of medical devices are inserted into a patient's body, advanced to an internal site of expansion in a contracted delivery configuration, and expanded to a deployed configuration to perform a treatment, measurement, or another intervention at the site of expansion. Many such devices are self-expandable such that they can expand to the deployed configuration when a constraining force is removed.

[0003] Various self-expanding medical devices can be compressed into a delivery configuration and placed within a catheter (e.g., a guide catheter, a microcatheter, a delivery catheter, etc.), and the catheter carrying the compressed device can be inserted into the patient's vasculature through an entry site and advanced to the desired site of intervention or measurement. Relative movement of the catheter with respect to the compressed device can position the device outside the catheter, where it can then self-expand. Examples of such intravascularly delivered self-expanding devices include suction funnels, stents, and clot mobilizers.

[0004] In some cases, the self-expanding medical device is compressed and loaded into the distal end of a delivery catheter prior to insertion at an entry site into the patient's vasculature, and the delivery catheter and compressed device are advanced together through the vasculature to the expansion site of the device. In some cases, the compressed device may be retracted a distance proximally within the delivery catheter during advancement of the catheter to make the portion of the delivery catheter distal to the compressed device more flexible, for example, to allow the catheter to navigate tortuous vasculature. The compressed device may then be advanced to the distal end of the delivery catheter and / or the delivery catheter withdrawn proximally, such that the compressed device may emerge and self-expand at the expansion site. The radially outward force exerted by the compressed self-expanding device against the inner wall of the catheter requires greater advancement and retraction forces than would be required for a device that is not self-expandable.

[0005] In other cases, a catheter or sheath can be advanced to the site of intervention or measurement without a self-expanding medical device, and the device can then be inserted into a proximal portion of the catheter and advanced through the catheter to the site of intervention or measurement, again requiring a greater radial outward force of the device against the inner wall of the catheter than would be required for a device that is not self-expandable.

[0006] As discussed above, a compressed self-expanding medical device may have to be advanced through tortuous vasculature (e.g., the carotid siphon) to reach the expansion site of the device. In some cases, the device may be advanced through the tortuous vasculature with a delivery catheter loaded with the compressed device. In other cases, the device may be advanced through the tortuous vasculature within a delivery catheter in which the device is stationary. In either case, the compressed device, or the combination of the compressed device and delivery catheter, should be sufficiently flexible to be advanceable through the tortuous vasculature with minimal advancement force.

[0007] In order to minimize the incision at the vascular entry site, the compressed self-expanding medical device and its delivery catheter must be as small as possible. Once at the expansion site, the device must expand from its compressed delivery configuration to its desired size and shape. In addition, some self-expanding medical devices (such as clot mobilizers and suction funnels) must be able to exert a sufficient radial outward force when self-expanded at the expansion site. Expansion sites within the vasculature can vary in diameter, and therefore the self-expanding medical device must be able to provide a sufficient radial outward force at every diameter within its diameter range.

[0008] The prior art describes a variety of intravascularly delivered, self-expanding medical devices.

[0009] For example, WO 03 / 075793 describes a self-expanding clot retriever that is delivered intravascularly. A generally tubular cage has a framework of struts that are biased to expand outwardly when radially unconstrained. The cage framework may be formed from wire segments or laser cut from a tube. The compressed cage is advanced to a desired expansion site within a microcatheter. Relative movement between a shaft extending proximally from the cage and the microcatheter allows the cage to self-expand out of the distal end of the microcatheter. This publication does not disclose the radially outward force exerted by the cage in its compressed and expanded configurations, nor does it describe structures that increase the flexibility of the cage while maintaining the cage's ability to navigate tortuous vasculature while compressed within a microcatheter and exert the desired radially outward force in its compressed and expanded configurations.

[0010] US Patent Publication No. 2017 / 0020555 describes an intravascularly delivered reperfusion device having a scaffold that self-expands to compress and dissolve thrombus within a vessel. The scaffold is delivered in its compressed form to the thrombus site within a microcatheter. The scaffold self-expands as relative motion between the scaffold and the microcatheter causes the scaffold to emerge from the microcatheter. A pusher at the proximal end of the scaffold can facilitate this relative motion. The publication discloses multiple scaffold patterns formed from laser cut tubes, including some patterns with features that enhance flexibility. It also discusses the general concept of providing a substantially constant outward radial force over a range of expanded diameters (corresponding to different vessel diameters), but does not explain which aspects of the scaffold structure, or which of the disclosed patterns, provide the desired radial force characteristics.

[0011] US Patent No. 9,700,331 describes a self-expanding vascular treatment device for capturing and removing embolic obstructions. The patent discloses multiple cell patterns for the expandable member. For example, a curvilinear cell pattern is described that enhances the flexibility of the compressed expandable member during delivery through tortuous vascular anatomy. The invention also generally discusses a desired range of expansion diameters and the outward radial force exerted by the expandable member over that range of expansion diameters. However, the patent does not describe a cell structure that enhances the flexibility of the expandable member in its compressed configuration while maintaining the desired outward radial properties of the expandable member over its range of expansion diameters.

[0012] WO 2019 / 05311 describes a medical device operable to extend and / or retract protrusions (e.g., anchors) in response to stresses applied by extending and / or retracting the device. In some embodiments, the device is self-expandable and can be delivered intravascularly. The publication does not disclose the radially outward force exerted by the cage in its compressed and expanded configurations, nor does it describe structures that increase the flexibility of the cage while maintaining the cage's ability to navigate tortuous vasculature while compressed within a microcatheter and exert a desired radially outward force in its compressed and expanded configurations. DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0013] Thus, there is a need for new and improved self-expanding medical devices that can navigate and be advanced through the vasculature, with suitable pushability and flexibility to expand and exert an appropriate outward radial force at a dilated site within a blood vessel. [Means for solving the problem]

[0014] The invention is defined by the accompanying independent claims. Embodiments are set out in the dependent claims.

[0015] According to one aspect, the present invention provides a self-expanding medical device for advancement through vasculature of different sizes, shapes and dimensions to a dilation site within a blood vessel. The self-expanding medical device of the present application comprises a working portion and a connecting portion extending proximally from a proximal end of the working portion, the connecting portion adapted to be connected to a pusher for advancing the device through the vasculature to the dilation site. The working portion includes a compressed form and an expanded form, the diameter of the expanded form being greater than the diameter of the compressed form, the working portion being configured to provide an outward radial force at every diameter between the diameter of the compressed form and the diameter of the expanded form, the working portion comprising a plurality of cell crowns, each cell comprising an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts, each of the proximal cell struts extending distally from a common proximal end to a proximal end of a respective one of the two middle cell struts, each of the distal cell struts extending proximally from a common distal end to a distal end of a respective one of the two middle cell struts, each middle cell strut within each crown bounding two adjacent cells within that crown, and each of the middle cell struts adapted and configured to be more flexible than the distal cell strut and the proximal cell strut from which it extends.

[0016] According to another aspect, the present invention also provides a self-expanding medical device of different sizes, shapes and dimensions for advancement through the vasculature to a dilation site in a blood vessel, comprising an active portion including a plurality of cell crowns, each cell including an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts, the middle cell struts bounding each cell having a width narrower than the width of the distal cell struts bounding each cell and narrower than the width of the proximal cell struts bounding that cell, the proximal cell struts each extend distally from a common proximal end to a proximal end of a respective one of the two middle cell struts, and the distal cell struts each extend proximally from a common distal end to a distal end of a respective one of the two middle cell struts, and each middle cell strut in each crown bounds two adjacent cells in that crown. The medical device also includes a connecting portion extending proximally from the proximal end of the working portion, the connecting portion adapted to be connected to a pusher for advancing the device through the vasculature to the dilation site.

[0017] The present invention provides flexibility to a self-expanding medical device into its compressed configuration without compromising the outward radial force exerted by the device in its expanded configuration, which is particularly useful for self-expanding medical devices whose working portions are designed to exert a substantial outward radial force in the expanded configuration over a range of expanded diameters.

[0018] In one embodiment, the working portion also includes a tapered portion at a proximal end of the working portion. The tapered portion may comprise a plurality of tapered portion struts. The tapered portion has an expanded diameter at the proximal end that is smaller than an expanded diameter of the working portion.

[0019] In one embodiment, the tapered portion comprises at least one cell crown of the plurality of cell crowns.

[0020] In one embodiment, the tapered portion has an expanded configuration that defines a frusto-conical shape having a closed configuration.

[0021] In one embodiment, the tapered portion further comprises a cell crown, each cell including an open area bounded by two proximal cell struts and two distal cell struts, in each cell, the proximal cell struts each extend distally from a common proximal end to a proximal end of a distal cell strut, and the distal cell struts each extend distally from their proximal ends to a common distal end.

[0022] In one embodiment, the tapered portion converges at a distal end of the connecting portion.

[0023] In one embodiment, the plurality of cell crowns of the working portion define a tubular portion forming a cylindrically closed structure. Alternatively or complementary, in one embodiment, the connecting portion comprises a tubular portion forming a cylindrically closed structure.

[0024] In one embodiment, the connecting portion includes at least one cell crown, each cell including an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts, each of the proximal cell struts extending distally from a common proximal end to a proximal end of a respective one of the two middle cell struts, each of the distal cell struts extending proximally from a common distal end to a distal end of a respective one of the two middle cell struts, each middle cell strut bounding two radially adjacent cells, each of the middle cell struts adapted and configured to be more flexible than the distal and proximal cell struts from which it extends.

[0025] In some embodiments, the self-expanding medical device comprises a pusher extending proximally from a connecting portion, in particular, the connecting portion having a first attachment surface and the pusher comprising a distally extending pusher connecting portion, the pusher connecting portion having a pusher attachment surface.

[0026] Additionally, in some embodiments, the pusher can comprise a tube, and the pusher mounting surface comprises a distal portion of the tube that is attached to the first mounting surface of the connecting portion. The tube can be a catheter or a hypotube. In other embodiments, the pusher can comprise a pusher wire, and the pusher mounting surface comprises a distal portion of the pusher wire that is attached to the first mounting surface of the connecting portion.

[0027] In some embodiments, a self-expanding medical device may include an improved attachment of its elements (i.e., the self-expanding medical device and its pusher, e.g., a catheter) including a catheter pusher comprising a catheter jacket, an inner catheter element surrounded by the catheter jacket, and a distal connection portion (i.e., pusher connection portion) including an extension of the inner catheter element extending distally beyond the distal end of the catheter jacket, a device (e.g., a funnel or clot mobilizer) attached to and extending from the distal connection portion of the catheter pusher, the device comprising a proximal connection portion, and an attachment between the device proximal connection portion and the pusher catheter distal connection portion adapted to keep the device connected to the catheter pusher, the attachment having an outer diameter substantially equal to an outer diameter of the pusher catheter.

[0028] The catheter jacket may be made from any suitable thermoplastic or elastomeric / elastomer material, for example, polyether block amide (PEBAX®) having a Shore of 25, 35, 40, 55, 63, or 72 D. In a particular embodiment, the catheter jacket is made from a thermoplastic material, more specifically PEBAX® 40D.

[0029] In one embodiment, the inner catheter element comprises an inner liner disposed within the catheter jacket, hi one embodiment, the inner liner comprises, inter alia, a polymeric material such as polytetrafluoroethylene (PTFE).

[0030] In one embodiment, the inner catheter element further comprises a braided layer disposed within the catheter jacket. In particular, the braided layer is concentrically disposed within the catheter jacket. The braided layer may be made of, for example, stainless steel, Nitinol, liquid crystal polymer (LCP), etc. In particular, it is made of Nitinol.

[0031] In one embodiment, the attachment comprises a thermoplastic material extending between the proximal connection portion of the device and the distal connection portion of the catheter pusher. In another embodiment, the attachment comprises a thermoplastic material extending over the proximal connection portion of the device and over the distal connection portion of the catheter pusher. The thermoplastic material may extend between and / or over the proximal and distal connection portions.

[0032] In the aforementioned embodiments, the pusher can be attached to the proximal connection portion of the self-expanding medical device by a sleeve that is bonded or mechanically held by a heat shrink process, by heat melting or heat sealing, by a chemical process, or by any other mechanical process.

[0033] According to one embodiment, the width of the middle cell strut bounding each cell is less than the width of the distal cell strut bounding that cell, and less than the width of the proximal cell strut bounding that cell.

[0034] In one embodiment, each of the distal cell struts has a width of 0.08 mm to 0.20 mm, particularly in the range of 0.08 mm to 0.10 mm, for example 0.09 mm. In one embodiment, each of the proximal cell struts has a width of 0.08 mm to 0.20 mm, particularly in the range of 0.08 mm to 0.10 mm, for example 0.09 mm. In one embodiment, each of the middle cell struts has a width of 0.05 mm to 0.15 mm, particularly in the range of 0.06 mm to 0.10 mm, for example 0.075 mm.

[0035] In some embodiments, the distal cell struts and the proximal cell struts have substantially the same width.

[0036] In one embodiment, the working portion comprises at least three cell crowns. In other embodiments, the working portion comprises four, five, six (or more) cell crowns. In any of these embodiments, each cell crown comprises at least four cells.

[0037] In one embodiment, each of the middle cell struts includes a hinge portion. In another embodiment, each of the middle cell struts includes two hinge portions. In any of these embodiments, each hinge portion of each middle cell strut is disposed between the proximal and distal ends of the middle cell strut.

[0038] In one embodiment, the hinge portion includes a bend that may be located at a central portion of the middle cell strut or closer to one end of the middle cell strut than to the other end of the middle cell strut, hi other embodiments, the hinge portion includes two bends.

[0039] In one embodiment, the hinge portion comprises a section of increased curvature.

[0040] In one embodiment, the hinge portion is integral with the mid-cell strut.

[0041] In one embodiment, in each cell crown of the working portion, the distal cell struts are arranged in a distal cell strut ring at equal distal cell strut positions along the longitudinal axis of the self-expanding medical device, the proximal cell struts are arranged in a proximal cell strut ring at equal proximal cell strut positions along the longitudinal axis of the device, and the common distal ends of the distal cell strut rings are circumferentially offset from the common proximal ends of the proximal cell strut rings.

[0042] In one embodiment, the common proximal end of the distal cell strut ring of each cell crown of the multiple cell crowns of the working portion is circumferentially offset in one circumferential direction from the common distal end of the proximal cell strut ring of that cell crown.

[0043] In one embodiment, the common proximal end of the distal cell strut ring of one cell crown of the multiple cell crowns of the working portion is offset from the common distal end of the proximal cell strut ring of the cell crown in a first circumferential direction, and the common proximal end of the distal cell strut ring of an adjacent cell crown of the multiple cell crowns of the working portion is offset from the common distal end of the proximal cell strut ring of the cell crown in a second circumferential direction opposite to the first circumferential direction.

[0044] In some embodiments, the intermediate cell struts of the second cell crown of the plurality of cell crowns of the working part extend distally from a common distal end of the distal cell struts of the first cell crown of the plurality of cell crowns of the working part to a common proximal end of the proximal cell struts of the third cell crown of the plurality of cell crowns of the working part, and the intermediate cell struts of the third cell crown of the working part extend distally from a common distal end of the distal cell struts of the second cell crown of the working part to a common proximal end of the proximal cell struts of the fourth cell crown of the plurality of cell crowns of the working part. Note that the above "first", "second", "third", and "fourth" should be understood as reference elements, and not as arrangement elements (i.e., following a specific order). That is, in this particular embodiment, the reference to the "first cell crown" does not necessarily refer to the first crown from the proximal part to the distal part, but to the first reference element.

[0045] In some embodiments, the distal cell struts of each cell in each cell crown may include the proximal cell struts of cells in the (following / subsequent) adjacent cell crown.

[0046] Alternatively or complementary, in some embodiments, the proximal cell struts of each cell in each cell crown may include the distal cell struts of cells in the (pre / anterior) adjacent cell crown.

[0047] In one embodiment, the working portion further comprises at least one crown of intermediate cells, each intermediate cell including an open area bounded by two proximal cell struts intersecting with two distal cell struts.

[0048] In one embodiment, the distal cell strut of each cell in at least one intermediate cell crown includes a proximal cell strut of a cell in an adjacent cell crown.

[0049] In one embodiment, a proximal cell strut of each cell in at least one intermediate cell crown includes a distal cell strut of a cell in an adjacent cell crown.

[0050] In one embodiment, the working portion is configured to expand from a compressed configuration to an expanded configuration having a diameter of 2.0 mm to 5.0 mm and to exert an outward radial force of 0 N to 3.5 N, for example 0.5 N to 3.5 N. In one embodiment, the working portion is configured to expand from a compressed configuration to an expanded configuration having a diameter of 3.0 mm to 4.5 mm and to exert an outward radial force of 1 N to 2 N.

[0051] In one embodiment, the working portion is configured to expand from a compressed configuration having a diameter of less than 2.0 mm to an expanded configuration having a diameter of at least 4.5 mm and to exert an outward radial force of 0.5 N to 3.5 N at all diameters between and including the diameter of the compressed configuration and the diameter of the expanded configuration.

[0052] In some embodiments, the self-expanding medical device comprises a funnel. In other embodiments, the self-expanding medical device comprises a clot mobilizer. In these other embodiments, the clot mobilizer can comprise a stent or a stent retriever.

[0053] In some embodiments, the self-expanding medical device may include a coating. In one embodiment, the device includes a coating on at least the tapered portion or a portion thereof. In one embodiment, the device includes a coating on the working portion. In one embodiment, the device includes a coating on the connecting portion. In yet another embodiment, the device includes a coating on all or a portion of the tapered portion, the working portion, and the connecting portion.

[0054] In the present invention, the diameter of the working portion in the maximum expanded configuration can be selected according to the target vessel diameter. Thus, in some embodiments, such a diameter can be 2 mm to 6 mm, particularly when the self-expanding medical device includes a clot mobilizer. In the case of a self-expanding medical device that includes a funnel, such a diameter can be 4 mm to 8 mm, for example, 5.2 mm or 6.6 mm.

[0055] In some embodiments, the self-expanding medical device may be made of metal, metal alloy, or composite material including Nitinol or Nitinol / Platinum. In particular, Nitinol material complies with ASTM (American Society of Testing and Materials) F2063 (Standard Specification for Wrought Nickel-Titanium Shape Memory Alloys for Medical Devices and Surgical Implants). Nitinol is well known for its application in self-expanding structures due to its shape memory properties. However, other types of metals or other types of materials, such as cobalt chromium alloys or iron alloys, such as stainless steel or spring steel, may also be used, as may other materials with shape memory properties, such as copper or magnesium alloys. Due to the shape memory properties and its structural form, the device can adapt its shape and its length to the surrounding lumen (e.g., surrounding carrier, catheter or blood vessel), and also allows the device to narrow and lengthen while passing through the surrounding lumen, and to retain any occluding material inside.

[0056] In some embodiments, the self-expanding medical device may include a radiopaque marker. In one embodiment, the radiopaque marker is included in the working portion. In another embodiment, the radiopaque marker is included in the connecting portion. In yet another embodiment, the radiopaque marker is included in the attachment means of the device with the pusher.

[0057] In one embodiment, the self-expanding medical device is manufactured by providing a tube having a longitudinal axis therethrough, providing a stationary laser radiation source, using the laser radiation source to generate a beam of laser radiation, and cutting a desired pattern in the tube by scanning the beam over a desired area of ​​the tube. In another embodiment, where the self-expanding medical device is a clot mobilizer (e.g., a stent retriever), the self-expanding medical device is manufactured by providing a wire having a longitudinal axis therethrough, and creating a predetermined cut in the cross section of the wire with an ultrashort pulsed laser to create a predetermined shape for the stent. For example, a suitable manufacturing method that may be used is described in US10434605B2.

[0058] Another aspect of the invention relates to a thrombus removal apparatus that includes the self-expanding medical device of the previous aspect of the invention, and specific embodiments thereof.

[0059] Yet another aspect of the invention provides a method of advancing a self-expandable medical device through a vasculature to a dilated site in a blood vessel of a patient. In some embodiments, the method includes the steps of advancing a self-expandable medical device in a delivery configuration through a delivery catheter to a dilated site in a blood vessel, the device including a working portion and a connecting portion extending proximally from a proximal end of the working portion, the connecting portion adapted to be connected to a pusher for advancing the device through the vasculature to the dilated site, the working portion including a compressed configuration and an expanded configuration, the expanded configuration having a diameter greater than the diameter of the compressed configuration, the working portion configured to provide an outward radial force at every diameter between and including the diameter of the compressed configuration and the diameter of the expanded configuration, the working portion including a crown of multiple cells, each cell including an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts, the proximal cell struts being configured to extend outwardly from the proximal cell struts to the distal cell struts. The method includes the steps of: each strut extends distally from a common proximal end to the proximal end of a respective one of the two middle cell struts, each distal cell strut extending proximally from the common distal end to the distal end of a respective one of the two middle cell struts, each middle cell strut in each crown bordering two adjacent cells in that crown, each middle cell strut adapted and configured to be more flexible than the distal and proximal cell struts from which it extends; expanding the working portion into a deployed form (i.e., an expanded form) in compression with the inner wall of the blood vessel within the expansion site with an outward radial force sufficient to reduce (i.e., partially or completely stop) proximal blood flow; and aspirating and capturing occlusive material (e.g., thrombus) within the device.

[0060] Some embodiments may include, after the expanding step, a step of adapting the shape and length of the self-expanding medical device to the surrounding vessel. Some other embodiments may include a step of moving the device within the vasculature, where the device adapts to the vessel diameter and expands as it narrows to retain the occlusive material within the device.

[0061] The self-expanding medical device can include a coating, in which case the method can include the step of allowing blood to flow through holes in the coating.

[0062] Some embodiments may include, after the aspirating step, moving the device from the deployed configuration to the retrieved configuration (ie, when the occlusive material is inside) and withdrawing the device outside the patient's body.

[0063] In some embodiments, the self-expanding medical device includes a pusher (e.g., a hypotube or catheter) attached to the proximal end of the connection portion, in which case the suction step can also include applying a vacuum to the interior space of the working portion through the catheter.

[0064] The advantages of the self-expanding medical device, derived from its structure and the parameters described herein, can be summarized as follows: -Sufficient radial force to advance in a compressed form and expand at the expansion site. The device allows for smaller radial forces at smaller diameters and larger radial forces at larger diameters without leaving the safety window. As a result, the outward radial force is maintained for a wide range of vessels with different diameters, achieving better pushability and reducing the risk of damaging the vessel. The tapered section also enhances / strengthens the outward radial force provided by the working section. - "Chinese finger trap" effect: this phenomenon occurs when an axial force is applied to the device by pulling it backwards, or when the device is held or braked by contacting a vessel. If there is an object inside (e.g. a blood clot), the device tends to lengthen, thus reducing its diameter, causing a compression that helps to hold the object inside the device. - Pushability: When the mesh is compressed within the carrier, the configuration of multiple cell crowns allows for proper compliance and movement when compressed, and the tapered section provides pushability for the device to be navigated through the vasculature (e.g., neuroanatomy) while minimizing buckling and kinking. - Conformity inside the vessel is achieved primarily through the construction of the proximal, distal and middle cell struts. These features allow the working part to adapt to the curvature of the vessel and avoid kinking of the device. [Brief description of the drawings]

[0065] The foregoing and other advantages and features will be more fully understood from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, which should be considered in an illustrative and non-limiting manner: [Figure 1] 1A and 1B are 2D diagrams showing two different embodiments of the proposed self-expanding medical device. [Diagram 2] 2A and 2B are 3D views of the 2D embodiment of the proposed self-expanding medical device shown in FIGS. 1A and 1B, respectively. [Diagram 3] Figures 3A and 3B are 3D views of the 2D embodiment of the proposed self-expanding medical device shown in Figures 1A and 1B, respectively, in which, unlike the Figures 2A and 2B views, the self-expanding medical device includes a coating. [Figure 4] FIG. 4 illustrates various examples of pusher elements that may be used to advance a self-expanding medical device through the vasculature to a dilation site. [Diagram 5] 5A and 5B show another embodiment of the proposed self-expanding medical device. [Figure 6] 6A-6B are schematic diagrams illustrating cross-sectional geometries of a first attachment surface and a pusher attachment surface, according to some embodiments. [Figure 7] 7A-7B are schematic illustrations of cross-sectional geometries of a first attachment surface and a pusher attachment surface according to other embodiments. [Figure 8] FIG. 8 graphically illustrates a comparison (radial outward force versus diameter) between different embodiments of the proposed self-expanding medical device, as described in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] 1A and 1B (showing the proposed self-expanding medical device 1, or simply the pattern cut from a solid tube to create device 1), two different embodiments of device 1 are shown for advancement through the vasculature to a site of dilation within a blood vessel. In either of these embodiments, device 1, which may be a funnel or clot mobilizer, has a working portion 101 and a connecting portion 103 extending proximally from a proximal end of working portion 101, which may be connected to a pusher 200, 300 extending proximally from the connecting portion.

[0067] The working portion 101 described herein is arranged and configured to provide an outward radial force at any diameter between, inclusive, the diameter of the compressed form of the working portion 101 and the diameter of the expanded form of the working portion 101. In some embodiments, the working portion 101 can expand from a compressed form having a diameter of less than 2.0 mm to an expanded form having a diameter of at least 4.0 mm and can exert an outward radial force of 0.5 N to 3.5 N at any diameter between, inclusive, the diameter of the compressed form and the diameter of the expanded form. In other embodiments, the working portion 101 can expand from a compressed form having a diameter of less than 3.0 mm to an expanded form having a diameter that is at least 4.5 mm and can exert an outward radial force of 1.0 N to 2.0 N at any diameter between, inclusive, the diameter of the compressed form and the diameter of the expanded form.

[0068] In the embodiment of Figures 1A and 1B, the working part 101 comprises a crown 110 of a plurality of cells 111 forming a tubular portion forming a cylindrically closed structure. The connecting part 103 also has, in particular, a tubular portion forming a cylindrically closed structure. More specifically, in the embodiment of Figure 1A, the working part 101 comprises a crown 110 of five cells 111, whereas in the embodiment of Figure 1B, the working part 101 comprises a crown 110 of four cells 111. This is not limiting, but in other embodiments, not shown in this case, the working part 101 simply needs to comprise (at least) three cell crowns, each having (at least) four cells.

[0069] Each of the cells of the working portion 101 has an open region bounded by two proximal cell struts 130, two distal cell struts 132, and two middle cell struts 112. Each of the proximal cell struts 130 extends distally from a common proximal end 134 to a proximal end 135 of a respective one of the two middle cell struts 112, and each of the distal cell struts 132 extends proximally from a common distal end 136 to a distal end 133 of a respective one of the two middle cell struts 112. Each middle cell strut 112 in each crown abuts two adjacent cells 111 in that crown and is adapted and configured to be more flexible than the distal cell struts 132 and proximal cell struts 130 from which it extends.

[0070] In some embodiments, the distal cell struts 132 of each cell 111 in each cell crown may comprise the proximal cell struts 130 of the cells 111 in the (subsequent) adjacent cell crown. Alternatively or complementary, in some embodiments, the proximal cell struts 130 of each cell 111 in each cell crown may comprise the distal cell struts 132 of the cells 111 in the (previous) adjacent cell crown.

[0071] In some embodiments, the middle cell struts 112 adjacent each cell 111 may have a width that is less than the width of the distal cell struts 132 adjacent the cell 111 and less than the width of the proximal cell struts 130 adjacent the cell 111. More specifically, the middle cell struts 112 may each have a width of at least 0.05 mm and not more than 0.15 mm, e.g., 0.075 mm, the distal cell struts 132 may each have a width of at least 0.08 mm and not more than 0.20 mm, e.g., 0.09 mm, and the proximal cell struts 130 may each have a width of at least 0.08 mm and not more than 0.20 mm, e.g., 0.09 mm. Further, in some embodiments, the distal cell struts 132 and the proximal cell struts 130 may have substantially the same width.

[0072] As can be seen, the middle cell strut 112 integrates one or two hinge portions 140 having a portion of increased curvature, which (these) are located / arranged between the proximal and distal ends of the middle cell strut 112. In Figure 1B, each hinge portion 140 further includes a bend which may be located in a central portion of the middle cell strut 112 or may be located closer to one end of the middle cell strut 112 than to the other end of the middle cell strut 112. In other embodiments, the hinge portion 140 comprises two bends.

[0073] In the crown 110 of each cell 111 of the active portion 101, the distal cell struts 132 are arranged in the distal cell strut ring 114 at equal distal cell strut positions along the longitudinal axis of the device 1, and the proximal cell struts 130 are arranged in the proximal cell strut ring 113 at equal proximal cell strut positions along the longitudinal axis of the device 1, and the common distal end of the distal cell strut ring 114 is circumferentially offset from the common proximal end of the proximal cell strut ring 113, in particular by one (see Figure 1A or 2A) or two or more (see Figure 1B or 2B) circumferentially offset.

[0074] In some embodiments, the working portion 101 may also include at least one intermediate cell crown, each intermediate cell including an open area bounded by two proximal cell struts intersecting with two distal cell struts. The distal cell struts of each cell in the at least one intermediate cell crown may include the proximal cell struts of a cell in an adjacent cell crown. Similarly, the proximal cell struts of each cell in the at least one intermediate cell crown may include the distal cell struts of a cell in an adjacent cell crown.

[0075] As can be seen, with reference to Figures 1A and 1B, in particular, the working portion 101 also includes a tapered portion 102 at its proximal end. The tapered portion 102 comprises a plurality of tapered portion struts and has an expanded diameter smaller than the expanded diameter of the working portion 101 at the proximal end. In these embodiments, the tapered portion 102 has an expanded form that defines a frustoconical shape having a closed structure. Furthermore, the tapered portion 102 includes one or more cell crowns of the crowns 110 of the plurality of cells 111. The tapered portion 102 converges at the distal end of the connecting portion 103.

[0076] 1A embodiment, tapered portion 102 also includes a cell crown 150, with each cell including an open region bounded by two proximal cell struts and two distal cell struts, in each cell, the proximal cell struts each extend distally from a common proximal end to a proximal end of a distal cell strut, and the distal cell struts each extend distally from their proximal ends to a common distal end.

[0077] With regard to the connecting portion 103, the latter includes a crown 120 of at least one cell 121, where each cell 121 has an open area bounded by two proximal cell struts, two distal cell struts, and two middle cell struts. The proximal cell struts each extend distally from a common proximal end to a proximal end of a respective one of the two middle cell struts. The distal cell struts each extend proximally from a common distal end to a distal end of a respective one of the two middle cell struts. Each middle cell strut bounds two radially adjacent cells and is configured to be more flexible than the distal and proximal cell struts from which it extends. The connecting portion 103 has an attachment surface 104 (or first attachment surface) that is connected to the pushers 200, 300 (see Figures 6A-6B and 7A-7B for further details).

[0078] The device 1 may be made from a metal, a metal alloy, or a composite material including Nitinol or Nitinol / Platinum, however, other types of metals or other types of materials may also be used, such as cobalt chromium alloys or iron alloys, such as stainless steel or spring steel, as well as other materials with shape memory properties, such as copper or magnesium alloys.

[0079] In some embodiments, the device 1 is completely coated, for example with a polymeric material, as illustrated in Figures 3A and 3B. In some embodiments, the coating is a hydrophilic or hydrophobic material. In some embodiments, the coating can be a non-permeable coating. Alternatively or complementary, the coating can include an elastomer or thermoplastic elastomer material, such as polyurethane or silicone, among others. While in the embodiment of Figures 3A and 3B the coating is disposed over the entire surface of the device 1, in other embodiments not shown the coating can simply cover at least one of the working portion 101, the tapered portion 102, or the connecting portion 103.

[0080] Because the coating is atraumatic (i.e., avoids damaging the vessel wall), the coating allows for safe retrieval / extraction of occlusive material, such as a thrombus, from a target site within the vessel. Additionally, the coating may increase the interaction of device 1 with occlusive material for proper extraction / retrieval. Also, the coating may increase the radial outward force exerted by device 1 on the surrounding vessel. Finally, the impermeable coating at least in tapered portion 102 allows device 1 to reduce (i.e., partially or completely stop) blood flow.

[0081] 4, there is shown various pusher elements 200, 300 that can be attached to the connecting portion 103. The pusher elements 200, 300 have a distally extending pusher connecting portion and a pusher attachment surface 204, 304 (see FIGS. 6A-6B and 7A-7B for further details). As shown in FIG. 4, the pusher 300 includes, but is not limited to, either a catheter 400 or a hypotube 500. The pusher 200 can include a pusher wire (200).

[0082] 5A-5B, another embodiment of the device 1 is shown. In this case, unlike the previous embodiment, the working portion 101 and the tapered portion 102 are also cut from a tube, but the connecting portion 103 does not include a tubular portion forming a cylindrically closed structure. As shown in the figures, the working portion 101 having a crown of cells 110 defined by a proximal cell strut ring 113, a distal cell strut ring 114, and a middle cell strut 112 extends between a common distal end 136 of the proximal cell struts 130 and a common proximal end 134 of the distal cell struts 132. The distal cell struts 132 of the crown are disposed in the distal cell strut ring 114 at equal distal cell strut positions along the longitudinal axis of the device 1, and the proximal cell struts 130 of said crown 110 are disposed in the proximal cell strut ring 113 at equal positions along the longitudinal axis of the device 1.

[0083] 5A (which shows the pattern that is cut from a solid tube to create device 1), middle cell strut 112 has a width that is less than the width of proximal cell strut 130 and distal cell strut 132, respectively, thereby making middle cell strut 112 more flexible than proximal cell strut 130 and distal cell strut 132. In some embodiments, distal cell strut 132 and proximal cell strut 130 may have substantially the same width.

[0084] In the embodiment of FIGS. 5A-5B , the common proximal ends of the distal cell strut rings 114 of a first cell crown of the plurality of cell crowns (i.e., the proximal ends of the middle cell struts 112) are offset in a first circumferential direction from the common distal end of the proximal cell strut ring 113 of the first cell crown (i.e., the distal end of the middle cell struts 112), and the common proximal ends of the distal cell strut rings 114 of a second cell crown of the plurality of cell crowns (i.e., the proximal ends of the middle cell struts 112) are offset in a second circumferential direction opposite the first circumferential direction from the common distal end of the proximal cell strut ring 113 of the first cell crown (i.e., the distal end of the middle cell struts 112). In one embodiment, the common distal ends of the proximal cell strut rings 113 of the first cell strut ring 112 are offset from the distal ends of the intermediate cell struts 112. This pattern is repeated for (or with) subsequent cell crowns such that in each successive cell crown the common distal ends of the proximal cell strut rings 113 are offset in alternating first and second circumferential directions. Thus, the crowns are arranged relative to one another in a zigzag pattern. In other embodiments (as seen in FIG. 1A ), the crowns may be arranged in only one circumferential direction and are arranged relative to one another in a spiral pattern.

[0085] 5A-5B includes four tapered portion struts and a radiopaque marker 107. An additional radiopaque marker 107 is also located at the distal end of the working portion 101. Additional radiopaque markers 107 can be included in other portions of the device 1 depending on the needs of the user.

[0086] 6A-6B and Figs. 7A-7B, which show several embodiments of the cross-sectional shapes of the first attachment surface 104 of the connecting portion 103 and the pusher attachment surfaces 204, 304 of the pushers 200, 300, and their corresponding arrangements.

[0087] 6A-6B show two embodiments in which the pusher 200 is a pusher wire. The pusher connecting portion 204 and the first attachment surface 104 of the connecting portion 103 are coaxially arranged. In FIG. 6A, the connecting portion 103 includes a cross-sectional shape of a portion of a ring. In FIG. 6B, the connecting portion 103 includes a cross-sectional shape of a circle.

[0088] 7A and 7B, the pusher 300 in particular comprises a tube. The tube may be a catheter 400 or a hypotube 500. Both figures show a coaxial arrangement between the pusher connecting portion 304 and the first attachment surface 104 of the connecting portion 103. In FIG. 7A, the pusher connecting portion 304 is coaxially arranged over (i.e., coaxially outwardly of) the attachment surface 104 of the connecting portion 103. In FIG. 7B, the attachment surface 104 of the connecting portion 103 is coaxially arranged over (i.e., coaxially outwardly of) the pusher connecting portion 304.

[0089] Example 1: Comparison of radial forces between a self-expanding medical device of the present invention and a control device <Introduction> This test was developed to compare the outward radial force (wall apposition) generated by the self-expanding medical devices of the present invention (as depicted in the embodiments of Figures 1A, 2A-uncoated and 3A-coated) as a function of vessel luminal diameter. After extracting the data, a graphical depiction (outward radial force vs. vessel diameter) was generated comparing the tested devices (Sample 1, coated and uncoated) against the control devices (control, coated and uncoated).

[0090] <Method> Both sample 1 and the control were tested for radial force (RF) measurements, with and without coating. Both RF and diameter of sample 1 and the control were measured using an RX550 from Machine Solutions Inc. The specific geometry of the head (12 segments) allows for uniform compression of the device to be tested with very low friction. The RX550 temperature was set to the specified test temperature. The sample was introduced into the head and the profile was started: the RX bench reduced and / or increased the diameter according to the specified profile, recording the RF and diameter. At the end of the test, the RX550 head was opened and the tested device was removed from the RX550 and then placed in its corresponding container. Finally, Figure 8 was plotted showing the individual RFs against the vessel diameter.

[0091] The intended use of the tested self-expanding medical devices is specifically 2.0 mm to 5.0 mm, however other self-expanding medical devices intended for larger vessel diameters (e.g., 6.0 mm) should follow the same requirements as described below and therefore exhibit flat-curve behavior.

[0092] The RF safety limit was defined starting from a vessel diameter of 2.0 mm, which should have a value below 3.5 N (i.e., upper safety limit), taking into account values ​​around 2 N ± 1.5 N in the controls. This value ensures the absence of endothelial damage and was therefore set as the maximum value. On the other hand, the minimum was defined to end at a vessel diameter of 5.0 mm, which should have a value above 0 N (lower safety limit), which is the minimum value for reaching the vasculature target site and extracting the thrombus in optimal conditions, with values ​​around 0.5 N being optimal, according to the controls. Most of the neurovascular interventions are performed in vessels with diameters in the range of 3.0 mm to 4.5 mm, therefore, radial force values ​​of 1 N to 2 N in these diameters are optimal for successful intervention.

[0093] Two controls were tested: one uncoated and one coated with a silicone polymer coating. Similarly, two samples 1 were tested: one uncoated and one coated with a silicone polymer coating. The coating is atraumatic (i.e., reduces damage to the blood vessel), improves the lubricity of the device when moving through the vasculature or inside the carrier, and allows the device to reduce blood flow in the expanded configuration. Furthermore, the addition of the coating increases the radial outward force exerted by the device on the surrounding lumen (e.g., blood vessel or carrier).

[0094] <Result> As shown in Figure 8, the values ​​of RF generated by the two tested devices (sample 1) were between the maximum limit of 3.5 N and the minimum limit of 0.5 N, in terms of vessel diameter, and the results were inscribed within the optimal range of vessel diameters (2.0 mm to 5.0 mm), generating a flat curve for a wide range of vessels. Thus, the curve provided by the proposed device 1 resulted in a method in which a lower RF (lower than the upper safety limit, i.e., 3.5 N) for small diameters and an upper RF (lower than the lower safety limit, i.e., 0.5 N) for large diameters were tolerated, thus leaving a limited safety window. Notably, the fact of having RF values ​​lower than the upper safety limit at small diameters reduces the risk of damaging the vessel. Also, the outward radial force for diameters in the common range around 3.0 mm and 4.5 mm was inscribed within the optimal range of 1 to 2 N, proving the successful intervention.

[0095] Therefore, the outward radial force of the self-expanding medical device is maintained for a wide range of blood vessels with different diameters, reducing the risk of damaging the blood vessels. In conclusion, the proposed medical devices are usable in blood vessels of different diameters, and their flexibility and pushability prove their suitable navigability through the vasculature to be expanded at the target location.

[0096] Throughout the specification and claims, the term "comprise" and variations thereof, such as "comprising," are not intended to exclude other technical features, components, steps, operations, and / or groups thereof. Additional objects, advantages, and features of the present invention will become apparent to those skilled in the art upon examination of the description or may be learned by the practice of the present invention. Moreover, the present invention encompasses all possible combinations of the specific preferred embodiments described herein. For example, the order in which the various described method steps are performed can often be changed in alternative embodiments, and in other alternative embodiments, one or more method steps may be skipped entirely. Any feature of the various device and system embodiments may be included in some embodiments and not in other embodiments. Thus, the foregoing description has been provided primarily for illustrative purposes and should not be construed as limiting the scope of the present invention, as set forth in the claims.

[0097] Additionally, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. However, the terms "first," "second," "third," "fourth," and the like may be used herein to describe various features / elements (including steps), and these features / elements should not be limited by these terms unless the context dictates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element discussed below may be referred to as a second feature / element, and similarly, a second feature / element discussed below may be referred to as a first feature / element without departing from the teachings of the present invention.

[0098] Unless otherwise indicated, all numbers expressing measurements, conditions, and the like used in the specification and claims should be understood to be modified in all instances by the term "about". Thus, unless indicated to the contrary, the numerical parameters set forth in the specification and the appended claims are approximations that may vary depending on the desired properties sought to be obtained by the subject matter of the present disclosure. The phrases "about" or "approximately" may be used when describing a magnitude and / or location to indicate that the described value and / or location is within a reasonable expected range of value and / or location. For example, a numerical value may have a value of ±0.1% (or range of values) of the described value, ±1% (or range of values) of the described value, ±2% (or range of values) of the described value, ±5% (or range of values) of the described value, ±10% (or range of values) of the described value, and the like. Any numerical value given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if a numerical value of "10" is described, it is considered that "10" itself and "about 10" are described. Any numerical ranges recited herein are intended to include all subranges subsumed therein. As would be well understood by one of ordinary skill in the art, when a value is disclosed, it is understood that "less than or equal to" the value, "more than or equal to" the value, and possible ranges between the values ​​are also disclosed. For example, when a value "X" is disclosed, "less than or equal to" as well as "more than or equal to X" (e.g., when X is a number) are also disclosed. It is also understood that throughout this application, data is provided in a number of different formats, and this data represents endpoints and starting points, as well as ranges for any combination of data points. For example, when data "10" and data "15" are described, it is understood that anything greater than, greater than, less than, less than, and the numbers themselves are described, as well as the range between these values ​​(10 to 15). Furthermore, a unit between the two values ​​is also considered to be described. For example, when "10" and "15" are described, it is also understood that the units between them, "11", "12", "13", and "14", are all described.

[0099] The present disclosure and / or some other examples have been described above. According to the above description, various modifications can be made. All applications, modifications and changes that are required to be protected in the claims may fall within the protection scope of the present disclosure.

[0100] The scope of the invention is defined in the following set of claims.

Claims

1. 1. A self-expanding medical device for advancement through the vasculature to a site of dilation within a blood vessel, comprising: A working portion (101) having a compressed form and an expanded form, the diameter of the expanded form being greater than the diameter of the compressed form, the working portion (101) being configured to provide an outward radial force at every diameter between and including the diameter of the compressed form and the diameter of the expanded form, the working portion comprising a crown (110) of a plurality of cells (111), each cell comprising an open area bounded by two proximal cell struts (130), two distal cell struts (132) and two intermediate cell struts (112), the proximal cell struts (130) each extending from a common proximal end (134) to the two intermediate cell struts (112). said distal cell struts (132) each extend proximally from a common distal end (136) to a proximal end (133) of one of said two intermediate cell struts (112), each intermediate cell strut (112) in each crown bounding two adjacent cells (111) in that crown, each of said intermediate cell struts (112) adapted and configured to be softer than the distal cell struts (132) and proximal cell struts (130) from which it extends, said working portion (101) further comprising a tapered portion (102) at a proximal end of said working portion (101); a connecting portion (103) extending proximally from a proximal end of the working portion (101), the connecting portion (103) being adapted to be connected to a pusher (200, 300) for advancing the device (1) through the vasculature to the dilation site; a plurality of crowns (110) of cells (111) of said working portion (101) defining a tubular portion forming a cylindrically closed structure; the tapered portion (102) comprises a plurality of tapered portion struts and a crown of at least one of the crowns (110) of the plurality of cells (111), has an expanded diameter at a proximal end that is smaller than an expanded diameter of the working portion (101), has an expanded configuration that defines a frusto-conical shape having a closed configuration, and converges at a distal end of the connecting portion (103); A device, characterized in that the connecting portion (103) comprises a tubular portion forming a cylindrically closed structure.

2. 2. The device of claim 1, wherein the tapered portion (102) further comprises a cell crown (150), each cell including an open area bounded by two proximal cell struts (130) and two distal cell struts (132), wherein in each cell, the proximal cell struts (130) each extend distally from a common proximal end to a proximal end of the distal cell strut (132), and the distal cell struts (132) each extend distally from their proximal ends to a common distal end.

3. 2. The device of claim 1, wherein the connecting portion (103) comprises a crown (120) of at least one cell (121), each cell (121) including an open area bounded by two proximal cell struts (130), two distal cell struts (132) and two middle cell struts (112), each of the proximal cell struts (130) extending distally from a common proximal end to a proximal end of one of the two middle cell struts (112), each of the distal cell struts (132) extending proximally from a common distal end to a distal end of one of the two middle cell struts (112), each middle cell strut (112) bounding two radially adjacent cells, each of the middle cell struts (112) adapted and configured to be more flexible than the distal cell struts (132) and the proximal cell struts (130) from which it extends.

4. 2. The device of claim 1, wherein the intermediate cell struts (112) that bound each cell have a width that is narrower than the width of the distal cell struts (132) that bound the cell and narrower than the width of the proximal cell struts (130) that bound the cell.

5. The device of claim 1 , wherein each of the middle cell struts (112) comprises one or two hinge portions (140), each hinge portion comprising one or two bends.

6. The device of claim 5 , wherein each hinge portion (140) of each middle cell strut (112) is disposed between a proximal end and a distal end of the middle cell strut (112).

7. 2. The device of claim 1, further comprising a pusher (200, 300) extending proximally from the connecting portion (103), the connecting portion (103) having a first attachment surface (104), the pusher (200, 300) comprising a pusher connecting portion extending distally, the pusher connecting portion having a pusher attachment surface (204, 304).

8. 8. The device of claim 7, wherein the pusher (300) comprises a tube, and the pusher mounting surface (304) comprises a distal portion of the tube that is attached to the first mounting surface (104).

9. The device of claim 8 , wherein the tube is a catheter (400) or a hypotube (500).

10. The device according to any one of claims 1 to 9, wherein the device (1) comprises a clot mobilizer or a funnel.

11. The device of claim 1, wherein the device (1) is made from a shape memory material and is capable of adapting its shape and length to the surrounding lumen and, as it passes through the surrounding lumen, narrowing and lengthening the device and retaining occlusion material within.

12. The device of claim 11, wherein the surrounding lumen is a carrier, a catheter, or a blood vessel.

13. The device of claim 1, wherein the device (1) is manufactured by providing a tube having a longitudinal axis, providing a fixed source of laser radiation, using the laser radiation source to generate a beam of laser radiation, and scanning the beam over a desired area of ​​the tube to cut a desired pattern in the tube.

14. The device of claim 1, wherein the device (1) has a coating on the tapered portion (102), or part thereof, the working portion (101), or the connecting portion (103).

15. The device (1) of claim 1, wherein the device (1) has a coating on at least one of the working portion (101), the tapered portion (102), and the connecting portion (103).

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