Patent Application
20240115281
The present invention is directed, in general, to the field of medical devices. In particular, the invention relates to a self-expandable medical device for advancement through vasculature to an expansion site in a blood vessel. The invention also provides methods of making and using such devices.
A wide array of medical devices are inserted into the patient's body, advanced to an expansion site within the body in a contracted delivery configuration, and expanded to a deployed configuration to perform a therapy, a measurement, or another intervention at the expansion site. Many such devices are self-expandable so that they can expand to their deployed configurations when a constraining force is removed.
A variety of self-expandable medical devices may be compressed into a delivery configuration and placed within a catheter (e.g., guide catheter, microcatheter, delivery catheter etc.), and the catheter carrying the compressed device may be inserted through an entry site into the patient's vasculature and advanced to the desired site of an intervention or a measurement. Relative movement of the catheter with respect to the compressed device may place the device outside of the catheter, and the device may then self-expand at the site. Examples of such endovascularly delivered self-expandable devices include aspiration funnels, stents, and clot mobilizers.
In some cases, the self-expandable medical device is compressed and loaded into the distal end of the delivery catheter before insertion at the entry site into the patient's vasculature, and the delivery catheter and compressed device are advanced together through the vasculature to the device's expansion site. In some cases, the compressed device may be withdrawn a distance proximally within the delivery catheter during the catheter's advancement to make a portion of the delivery catheter distal to the compressed device more flexible to, e.g., enable the catheter to navigate tortuous vasculature. The compressed device is thereafter advanced to the distal end of the delivery catheter and/or the delivery catheter is retrieved proximally so that the compressed device can emerge and self-expand at the expansion site. The radially outward force exerted by the compressed self-expandable device on the inside wall of the catheter requires greater advancement and retraction forces than would be required for devices that are not self-expandable.
In other cases, the catheter or sheath may be advanced to the site of the intervention or measurement without the self-expandable medical device, and the device may thereafter be inserted into a proximal portion of the catheter and advanced through the catheter to the site of the intervention or measurement. Once again, the device's radially outward force against the inside wall of the catheter requires a greater advancement force than would be required for devices that are not self-expandable.
As discussed above, the compressed self-expandable medical device may have to be advanced through tortuous vasculature (e.g., the carotid syphon) to reach the device's expansion site. In some cases, the device may be advanced through the tortuous vasculature together with a delivery catheter into which the compressed device has been loaded. In other cases, the device may be advanced through the tortuous vasculature within a stationary delivery catheter. In either cases, 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 a minimum of advancement force.
In order for the incision at the vascular entry site to be as small as possible, the compressed self-expandable medical device and its delivery catheter should 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-expandable medical devices (such as, e.g., clot mobilizers and aspiration funnels) must be able to apply a sufficient radially outward force when self-expanded at the expansion site. Expansion sites within the vasculature may vary in diameter; the self-expandable medical device must therefore be able to provide a sufficient radially outward force at every diameter within that range of diameters.
The prior art describes a variety of endovascularly delivered self-expandable medical devices.
For example, WO 03/075793 describes an endovascularly delivered self-expandable clot retriever. A generally tubular cage has a framework of struts that are biased to expand in an outward direction when unconstrained radially. The framework of the cage may be formed from wire segments, or it may be laser cut from a tube. The compressed cage is advanced to the desired expansion site within a microcatheter. Relative movement between a shaft extending proximally from the cage and the microcatheter allows the cage to emerge from the distal end of the microcatheter and self-expand. This publication does not disclose the radially outward forces exerted by the cage in its compressed and expanded configurations, nor does it describe structure enhancing the flexibility of the cage while preserving the cage's ability to navigate tortuous vasculature while compressed within the microcatheter and to exert desired radially outward forces in its compressed and expanded configurations.
US 2017/0020555 describes an endovascularly delivered reperfusion device with a scaffold that self-expands to compress and lyse a thrombus within a blood vessel. The scaffold is delivered in its compressed configuration within a microcatheter to the thrombus site. The scaffold self-expands when relative movement between the scaffold and microcatheter causes the scaffold to emerge from the microcatheter. A pusher at the proximal end of the scaffold may facilitate this relative movement. This 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 radial outward force across a range of expansion diameters (corresponding to different blood vessel diameters), but without describing what aspects of the scaffold structure, or which of the disclosed patterns, provide the desired radial force characteristics.
U.S. Pat. No. 9,700,331 describes a self-expandable vascular treatment device for capturing and removing embolic obstructions. This patent discloses multiple cell patterns for the expandable member. For example, it describes curvilinear cell patterns that enhance the flexibility of the compressed expandable member during delivery through tortuous vascular anatomy. It also discusses generally the desired range of expansion diameters and outward radial force applied by the expandable member over that range of expansion diameters. This patent does not describe, however, a cell structure that enhances flexibility of the expandable member in its compressed configuration while maintaining the desired outward radial characteristics of the expandable member over its range of expansion diameters.
WO 2019/05311 describes a medical device operable to extend and/or retract projections (e.g., anchors) in response to a stress applied by way of stretching and/or retracting the device. In some embodiments, the device is self-expandable and may be endovascularly delivered. This publication does not disclose the radially outward forces exerted by the cage in its compressed and expanded configurations, nor does it describe structure enhancing the flexibility of the cage while preserving the cage's ability to navigate tortuous vasculature while compressed within the microcatheter and to exert desired radially outward forces in its compressed and expanded configurations.
Therefore, new and improved self-expandable medical devices able to navigate and be advanced through vasculature, with proper pushability and flexibility, to be expanded in an expansion site in a blood vessel exerting appropriate outward radial forces, are therefore needed.
The invention is defined by the attached independent claims. Embodiments are described in the dependent claims.
According to one aspect, the present invention provides a self-expandable medical device for advancement through vasculature, of different sizes, shapes and dimensions, to an expansion site in a blood vessel. The self-expandable medical device comprises a working portion and a connection portion extending proximally from a proximal end of the working portion, the connection portion being adapted to be connected to a pusher for advancing the device through the vasculature to the expansion site. The working portion comprises a compressed configuration and an expanded configuration, a diameter of the expanded configuration being greater than a diameter of the compressed configuration, the working portion being 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 comprising a plurality of crowns of cells, each cell comprising an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts, the proximal cell struts each extending 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 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 in each crown bordering two adjacent cells in that crown, each of the middle cell struts being adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends.
According to another aspect, the present invention also provides a self-expandable medical device for advancement through vasculature, of different sizes, shapes and dimensions, to an expansion site in a blood vessel, comprising a working portion comprising a plurality of crowns of cells, each cell comprising an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts, the middle cell struts bordering each cell having a width less than a width of the distal cell struts bordering that cell and less than a width of the proximal cell struts bordering that cell, the proximal cell struts each extending 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 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 in each crown bordering two adjacent cells in that crown. The medical device also comprises a connection portion extending proximally from a proximal end of the working portion, the connection portion being adapted to be connected to a pusher for advancing the device through the vasculature to the expansion site.
The present invention provides flexibility to the compressed configuration of the self-expandable medical device without compromising the outward radial force exerted by the device in its expanded configurations. This is particularly useful for self-expandable medical devices whose working portions are designed to apply a substantial outward radial force in their expanded configurations over a range of expansion diameters.
In an embodiment, the working portion also includes a tapered portion at the proximal end of the working portion. The tapered portion can comprise a plurality of tapered portion struts. The tapered portion has an expanded diameter at a proximal end that is smaller than an expanded diameter of the working portion.
In an embodiment, the tapered portion comprises at least one crown of cells of the plurality of crowns of cells.
In an embodiment, the tapered portion has an expanded configuration defining a frustoconical shape with a closed structure.
In an embodiment, the tapered portion further comprises a crown of cells with each cell comprising an open area bordered by two proximal cell struts and two distal cells struts, in each cell the proximal cell struts each extending distally from a common proximal end to proximal ends of the distal cell struts, the distal cell struts each extending distally from their proximal ends to a common distal end.
In an embodiment, the tapered portion converges at a distal end of the connection portion.
In an embodiment, the plurality of crowns of cells of the working portion defines a tubular-shaped section forming a cylindrically closed structure. Alternatively or complementarily, in an embodiment, the connection portion comprises a tubular-shaped section forming a cylindrically closed structure.
In an embodiment, the connection portion comprises at least one crown of cells, each cell comprising an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts, the proximal cell struts each extending 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 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 bordering two radially adjacent cells, each of the middle cell struts being adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends.
In some embodiments, the self-expandable medical device comprises a pusher extending proximally from the connection portion. In this case, particularly, the connection portion has a first attachment surface, and the pusher comprises a pusher connection portion extending distally, the pusher connection portion having a pusher attachment surface.
Moreover, in some embodiments, the pusher can comprise a tube, the pusher attachment surface comprising a distal portion of the tube attached to the first attachment surface of the connection portion. The tube can be a catheter or a hypotube. In other embodiments, the pusher can comprise a pusher wire, the pusher attachment surface comprising a distal portion of the pusher wire attached to the first attachment surface of the connection portion.
In some embodiments, the self-expandable medical device can comprise an improved attachment of its elements (i.e., self-expandable medical device and its pusher, e.g., a catheter). The device includes 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) comprising an extended portion of the inner catheter element extending distally beyond a distal end of the catheter jacket; the device (e.g., 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.
The catheter jacket can be made of any suitable thermoplastic material or elastomeric/elastomer material, e.g., polyether block amide (PEBAX®) with shore 25, 35, 40, 55, 63 or 72D. In a particular embodiment, the catheter jacket is made of a thermoplastic material, more particularly of PEBAX® 40D.
In an embodiment, the inner catheter element comprises an inner liner disposed within the catheter jacket. In an embodiment, the inner liner comprises a polymer material, such as polytetrafluoroethylene (PTFE), among others.
In an embodiment, the inner catheter element further comprises a braided layer disposed within the catheter jacket. Particularly, the braided layer is concentrically disposed within the catheter jacket. The braided layer can be made of e.g., stainless steel, nitinol, liquid crystal polymer (LCP), etc. Particularly, it is made of nitinol.
In an 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 can extend between and/or over the proximal connection portion and the distal connection portion.
In the previous embodiments, the pusher can be attached to the proximal connection portion of the self-expandable medical device by a sleeve that is boned or mechanically held by a heat shrink process, by thermal melting or fusing, by means of a chemical process or by means of any other mechanical process.
In an embodiment, the middle cell struts bordering each cell have a width less than a width of the distal cell struts bordering that cell and less than a width of the proximal cell struts bordering that cell.
In an embodiment, the distal cell struts each have a width greater than or equal to 0.08 mm and less than or equal to 0.20 mm, in particular, in the range between 0.08 mm and 0.10 mm, for example 0.09 mm. In an embodiment, the proximal cell struts each have a width greater than or equal to 0.08 mm and less than or equal to 0.20 mm, in particular, in the range between 0.08 mm and 0.10 mm, for example 0.09 mm. In an embodiment, the middle cell struts each have a width greater than or equal to 0.05 mm and less than or equal to 0.15 mm, in particular, in the range between 0.06 mm and 0.10 mm, for example 0.075 mm.
The distal cell struts and the proximal cell struts in some embodiments have substantially the same width.
In an embodiment, the working portion comprises at least three crowns of cells. In other embodiments, the working portion comprises four, five, six (or even more) crowns of cells. In any of these embodiments, each crown of cells comprises at least four cells.
In an embodiment, each of the middle cell struts comprises a hinge portion. In another embodiment, each of the middle cell struts comprises two hinge portions. In any of these embodiments, each hinge portion of each middle cell strut is disposed between the proximal and the distal ends of the middle cell strut.
In an embodiment, the hinge portion comprises a bend that can be disposed either in a central portion of the middle cell strut or closer to one end of the middle cell strut than to another end of the middle cell strut. In other embodiments, the hinge portion comprises two bends.
In an embodiment, the hinge portion comprises a section of increased curvature.
In an embodiment, the hinge portion is integral with the middle cell strut.
In an embodiment, in each crown of cells of the working portion: the distal cell struts are disposed in a distal cell strut ring at equal distal cell strut positions along a longitudinal axis of the self-expandable medical device, the proximal cell struts are disposed 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 ring are circumferentially offset from the common proximal ends of the proximal cell strut ring.
In an embodiment, the common proximal ends of the distal cell strut ring of each crown of cells of the plurality of crowns of cells of the working portion are circumferentially offset from the common distal ends of the proximal cell strut ring of that crown of cells in one circumferential direction.
In an embodiment, the common proximal ends of the distal cell strut ring of a crown of cells of the plurality of crowns of cells of the working portion are offset from the common distal ends of the proximal cell strut ring of that crown of cells in a first circumferential direction and the common proximal ends of the distal cell strut ring of an adjacent crown of cells of the plurality of crowns of cells of the working portion are offset from the common distal ends of the proximal cell strut ring of that crown of cells in a second circumferential direction opposite to the first circumferential direction.
In some embodiments, the middle cell struts of a second crown of cells of the plurality of crowns of cells of the working portion extend distally from common distal ends of distal cell struts of a first crown of cells of the plurality of crowns of cells of the working portion to common proximal ends of proximal cell struts of a third crown of cells of the plurality of crowns of cells of the working portion, and the middle cell struts of the third crown of cells of the working portion extend distally from common distal ends of distal cell struts of the second crown of cells of the working portion to common proximal ends of proximal cell struts of a fourth crown of cells of the plurality of crowns of cells of the working portion. Note that the previous mention to “first”, “second”, “third” and “fourth” should be understood as reference elements and not to disposition elements (i.e., following a specific order). That is, in this particular embodiment, the indication to “first crown of cells” does not necessarily refer to the first crown from the proximal portion to the distal portion but a first reference element.
In some embodiments, the distal cell struts of each cell in each crown of cells can comprise the proximal cell struts of cells in a (posterior/subsequent) adjacent crown of cells.
Alternatively or complementary, in some embodiments, the proximal cell struts of each cell in each crown of cells can comprise the distal cell struts of cells in a (anterior/previous) adjacent crown of cells.
In an embodiment, the working portion further comprises at least one crown of intermediate cells. Each intermediate cell comprises an open area bordered by two proximal cell struts intersecting with two distal cell struts.
In an embodiment, the distal cell struts of each cell in the at least one crown of intermediate cells comprise the proximal cell struts of cells in an adjacent crown of cells.
In an embodiment, the proximal cell struts of each cell in the at least one crown of intermediate cells comprise the distal cell struts of cells in an adjacent crown of cells.
In an embodiment, the working portion is configured to expand from the compressed configuration to the expanded configuration with a diameter between 2.0 mm and 5.0 mm and to exert an outward radial force between 0 N and 3.5 N, for example between 0.5 N and 3.5 N. In an embodiment, the working portion is configured to expand from the compressed configuration to the expanded configuration with a diameter between 3.0 mm and 4.5 mm and to exert an outward radial force between 1 N and 2N.
In an embodiment, the working portion is configured to expand from the compressed configuration with a diameter being less than 2.0 mm to the expanded configuration with a diameter being at least 4.5 mm and to exert an outward radial force between 0.5 N and 3.5 N at every diameter between and including the diameter of the compressed configuration and the diameter of the expanded configuration.
In some embodiments, the self-expandable medical device comprises a funnel. In other embodiments, the self-expandable medical device comprises a clot mobilizer. In these other embodiments, the clot-mobilizer can comprise a stent or stent-retriever.
In some embodiments, the self-expandable medical device can include a coating. In an embodiment, the device comprises a coating on at least the tapered portion, or part thereof. In an embodiment, the device comprises a coating on the working portion. In an embodiment, the device comprises a coating on the connection portion. In yet another embodiment, the device comprises a coating on all or some of the tapered portion, working portion, and connection portion.
In the present invention, the diameter of the working portion in a maximum expanded configuration can be selected depending on the intended blood vessel diameter. Thus, in some embodiments, particularly if the self-expandable medical device comprises a clot mobilizer, such diameter can be equal to or greater than 2 mm and equal to or less than 6 mm. For the case of the self-expandable medical device comprising a funnel, such diameter can be equal to or greater than 4 mm and equal to or less than 8 mm, for example 5.2 mm or 6.6 mm.
In some embodiments, the self-expandable medical device can be made of a metal, a metal alloy or a composite including Nitinol or Nitinol/Platinum. In particular, the Nitinol material complies with the 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 applications in self-expanding structures, thanks to its shape-memory properties. However, other types of metals or even other types of materials can be also used, for example cobalt-chromium alloys or iron alloys such as stainless steel or spring steel; also, other materials with shape memory properties can be used, for example cooper or magnesium alloys. Thanks to the shape-memory properties and its structural configuration, the device is able to adapt its shape and its length to the surrounding lumen (e.g., surrounding carrier, catheter or vessel), also, while passing through the surrounding lumen, such that the device narrows and lengthens, allowing to retain any obstruction material inside.
In some embodiments, the self-expandable medical device can include radiopaque markers. In an embodiment, the radiopaque markers are included in the working portion. In other embodiments, the radiopaque markers are included in the connection portion. In yet another embodiment, the radiopaque markers are included in the attachment means of the device with the pusher.
In an embodiment, the self-expandable medical device is manufactured by providing a tube, having a longitudinal axis therethrough, providing a stationary source of laser radiation, generating a beam of laser radiation using the source of laser radiation, and cutting a desired pattern into the tube by scanning the beam over a desired region of the tube. In another embodiment, in which the self-expandable medical device is a clot mobilizer (e.g., a stent-retriever) it is manufactured by providing a wire; having a longitudinal axis therethrough, producing predetermined cuts of the cross section of the wire by means of an ultrashort pulse laser in order to produce a predetermined shape of the stent. For example, a suitable manufacturing method that could be used is described in U.S. Ser. No. 10/434,605B2.
Another aspect of the invention is related to a thrombectomy apparatus including the self-expandable medical device of the previous aspects of the invention, and particular embodiments thereof.
Yet another aspect of the invention provides a method of advancement of a self-expandable medical device through vasculature to an expansion site in a blood vessel of a patient. In some embodiments, the method includes the steps of advancing the self-expandable medical device through a delivery catheter in a delivery configuration to an expansion site within a blood vessel, the device including a working portion and a connection portion extending proximally from a proximal end of the working portion, the connection portion being adapted to be connected to a pusher for advancing the device through the vasculature to the expansion site, the working portion comprising a compressed configuration and an expanded configuration, a diameter of the expanded configuration being greater than a diameter of the compressed configuration, the working portion being 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 comprising a plurality of crowns of cells, each cell comprising an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts, the proximal cell struts each extending 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 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 in each crown bordering two adjacent cells in that crown, each of the middle cell struts being adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends; expanding the working portion into a deployment configuration (i.e., expanded configuration) in apposition with an inner wall of the blood vessel in the expansion site, with an outward radial force sufficient to reduce (i.e., partially or completely stop) proximal blood flow; and aspirating and capturing an obstructing material (e.g., a thrombus) into the device.
Some embodiments can include, after the expanding step, adapting the self-expandable medical device shape and length to the surrounding blood vessel. Some other embodiments can include the step of moving the device within the vasculature, the device lengthening as it narrows to adapt to the vessel diameter and to retain the obstructing material within the device.
The self-expandable medical device can include a coating, in which case the method can include the step of permitting blood to flow through holes in the coating.
Some embodiments can include the step of, after the aspirating step, moving the device from the deployment configuration to a retrieval configuration (i.e., when the obstruction material is inside) to withdraw the device outside the patient body.
In some embodiments, the self-expandable medical device includes a pusher (e.g., a hypotube or a catheter) attached to a proximal end of the connection portion, in which case the aspirating step can also include the step of applying a vacuum through the catheter to interior spaces of the working portion.
Advantages of the self-expandable medical device derived from its structure and the parameters described herein, can be summarized as follows:
The previous and other advantages and features will be more fully understood from the following detailed description of embodiments, with reference to the attached figures, which must be considered in an illustrative and non-limiting manner, in which:
With reference to
The working portion 101 described therein is arranged and configured to provide an outward radial force at every diameter between and including a diameter of a compressed configuration of the working portion 101 and a diameter of an expanded configuration of the working portion 101. In some embodiments, the working portion 101 can expand from the compressed configuration with a diameter being less than 2.0 mm to the expanded configuration with a diameter being at least 4.0 mm and to exert an outward radial force between 0.5 N and 3.5 N at every diameter between and including the diameter of the compressed configuration and the diameter of the expanded configuration. In other embodiments, the working portion 101 can expand from the compressed configuration with a diameter being less than 3.0 mm to the expanded configuration a diameter being at least 4.5 mm and to exert an outward radial force between 1.0 N and 2.0 N at every diameter between and including the diameter of the compressed configuration and the diameter of the expanded configuration.
In the embodiments of
Each of the cells of the working portion 101 has an open area bordered by two proximal cell struts 130, two distal cell struts 132 and two middle cell struts 112. The proximal cell struts 130 each extend distally from a common proximal end 134 to a proximal end 135 of a respective one of the two middle cell struts 112, and the distal cell struts 132 each extend 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 border two adjacent cells 111 in that crown, and is adapted and configured to be more flexible than the distal cell strut 132 and proximal cell strut 130 to which it extends.
In some embodiments, the distal cell struts 132 of each cell 111 in each crown of cells can comprise the proximal cell struts 130 of cells 111 in a (posterior/subsequent) adjacent crown of cells. Alternatively or complementary, in some embodiments, the proximal cell struts 130 of each cell 111 in each crown of cells can comprise the distal cell struts 132 of cells 111 in a (anterior/previous) adjacent crown of cells.
In some embodiments, the middle cell struts 112 bordering each cell 111 can have a width less than a width of the distal cell struts 132 bordering that cell 111 and less than a width of the proximal cell struts 130 bordering that cell 111. More in particular, the middle cell struts 112 each can have a width greater than or equal to 0.05 mm and less than or equal to 0.15 mm, for example 0.075 mm, the distal cell struts 132 each can have a width greater than or equal to 0.08 mm and less than or equal to 0.20 mm, for example 0.09 mm, and the proximal cell struts 130 each can have a width greater than or equal to 0.08 mm and less than or equal to 0.20 mm, for example 0.09 mm. In yet some embodiments, the distal cell struts 132 and the proximal cell struts 130 can have substantially the same width.
As seen in the figures, the middle cell struts 112 integrate one or two hinge portions 140, having a section of increased curvature, that is/are arranged/disposed between the proximal and the distal ends of the middle cell strut 112. In
In each crown 110 of cells 111 of the working portion 101, the distal cell struts 132 are disposed in a distal cell strut ring 114 at equal distal cell strut positions along a longitudinal axis of the device 1; the proximal cell struts 130 are disposed in a proximal cell strut ring 113 at equal proximal cell strut positions along the longitudinal axis of the device 1; and the common distal ends of the distal cell strut ring 114 are circumferentially offset from the common proximal ends of the proximal cell strut ring 113, particularly, in one (see
In some embodiments, the working portion 101 can also include at least one crown of intermediate cells, each intermediate cell comprising an open area bordered by two proximal cell struts intersecting with two distal cell struts. The distal cell struts of each cell in the at least one crown of intermediate cells can comprise the proximal cell struts of cells in an adjacent crown of cells. Similarly, the proximal cell struts of each cell in the at least one crown of intermediate cells can comprise the distal cell struts of cells in an adjacent crown of cells.
As can be seen in
In the embodiment of
With regard to the connection portion 103, the latter comprises at least one crown 120 of cells 121, where each cell 121 has an open area bordered 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 border two radially adjacent cells, and is adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends. The connection portion 103 has an attachment surface 104 (or first attachment surface) to be connected to a pusher 200, 300 (see
The device 1 can be made of a metal, a metal alloy or a composite including Nitinol or Nitinol/Platinum. However, other types of metals or even other types of materials can be also used, for example cobalt-chromium alloys or iron alloys such as stainless steel or spring steel; also, other materials with shape memory properties can be used, for example cooper or magnesium alloys.
In some embodiments, as illustrated in
Alternatively or complementarily, the coating can comprise an elastomeric or thermoplastic elastomer material such as polyurethane or silicone, among others. Although in the embodiments of
The coating enables a safe retrieval/extraction of obstruction material, such as a thrombus, from a target site in a blood vessel, since the coating is atraumatic (i.e., avoids damaging the blood vessel wall). Further, the coating can increase the interaction of the device 1 with the obstruction material, for a proper extraction/retrieval. Also, the coating can increase the outward radial forces exerted by the device 1 to the surrounding blood vessel. Finally, a non-permeable covering at least in the tapered portion 102 allows the device 1 to reduce (i.e., partially, or completely stop) the blood flow.
With reference now to
With reference to
Particularly, as shown in the flattened view of
In the embodiment of
The tapered portion 102 in the embodiment of
With reference to
Regarding now to
Introduction
This test was developed in order to compare the outward radial forces (wall apposition) generated by the self-expandable medical device of the present invention (described in embodiments of
Methods
Both the Sample 1 and the Control were tested, with and without coating, for radial force (RF) measurement. The RX550 from Machine Solutions Inc. was used to measure both, the RFs and the diameter of the Sample 1 and of the Control. The specific geometry of the head (12 segments) allows compressing the tested device uniformly, with very low friction force. RX550 temperature was set to the defined test temperature. The samples were introduced in the head and profile was started: the RX bench decreases and/or increases the diameter according to specified profile and the RFs and diameter were recorded. At the end of the test, RX550 head was opened, and the tested device was retrieved from the RX550 then placed within its corresponding container. Lastly,
The intended use for the tested self-expandable medical device is, particularly, between 2.0 mm and 5.0 mm. However, other self-expandable medical devices intended for larger vessel diameters (e.g., 6.0 mm) should follow the same requirements and therefore, present a flat-curve behavior, as explained below.
RF safety limits were defined starting from the vessel diameter of 2.0 mm, which should have a value lower than 3.5 N (i.e., upper safety limit), considering the value near 2 N±1.5 N for the Control. This value assured that there were not endothelial damage and, therefore, was set as the maximum value. On the other hand, the minimum value was defined ending in the vessel diameter of 5.0 mm, which should have a value greater than 0 N (lower safety limit), which was the minimum value to reach the vasculature target site and to extract a thrombus in optimal conditions, according to the Control, a value near 0.5 N is optimal. Most of neurovascular interventions are carried out in vessels with diameter in the range near and between 3.0 mm and 4.5 mm; therefore, a radial force value between 1 N and 2 N in those diameters is optimal to succeed in the intervention.
Two Controls were tested: one uncoated and another coated with a silicone polymer coating. Similarly, two Samples 1 were tested: one uncoated and another coated with a silicone polymer coating. The coating is atraumatic (i.e., reduces damaging the vessel), improves the lubricity of the device when being moved through vasculature or inside a carrier, and allows the device to reduce the blood flow in the expanded configuration. Furthermore, the addition of the coating increases the outward radial forces exerted by the device to the surrounding lumen (e.g., blood vessel or carrier).
Results
As is shown in
Therefore, the outward radial forces of the self-expandable medical device are maintained for a broad range of vessels with different diameters and the risk of damaging the vessel is reduced. In conclusion, the proposed medical device is usable in blood vessels of different diameters, and their flexibility and pushability certifies a proper navigability through vasculature to be expanded in a target location.
Throughout the description and claims the word “comprise” and its variations 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 invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.
Additionally, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Although the terms “first”, “second”. “third”, “fourth” etc. may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.
Unless otherwise indicated, all numbers expressing measurements, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.
The present disclosure and/or some other examples have been described in the above. According to descriptions above, various alterations may be achieved. All applications, modifications and alterations required to be protected in the claims may be within the protection scope of the present disclosure.
The scope of the present invention is defined in the following set of claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21382165.5 | Feb 2021 | EP | regional |
| PCT/EP2021/069623 | Jul 2021 | WO | international |
| 21383179.5 | Dec 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/054500 | 2/23/2022 | WO |
