Patent Application
20240207577
Guidewire devices are often used to lead or guide catheters or other interventional devices to a targeted anatomical location within a patient's body. Typically, guidewires are passed into and through a patient's vasculature in order to reach the target location, which may be at or near the patient's heart or brain, for example. Radiographic imaging is typically utilized to assist in navigating a guidewire to the targeted location. In many instances, a guidewire is placed within the body during the interventional procedure where it can be used to guide multiple catheters or other interventional devices to the targeted anatomical location.
Guidewires are available with various outer diameter sizes. Widely utilized sizes include 0.010, 0.014, 0.016, 0.018, 0.024, 0.035, and 0.038 inches, for example, though they may also be smaller or larger in diameter. Because torque transmission is a function of diameter, larger diameter guidewires typically have greater torque transmission (the ability to effectively transfer torque from proximal portions of the wire to more distal portions of the wire). On the other hand, smaller diameter guidewires typically have greater flexibility.
A catheter used in conjunction with a guidewire will be sized with an inner diameter somewhat larger than the outer diameter of the guidewire to enable the catheter to be positioned over and translated upon the guidewire. The difference in size between the guidewire and catheter can affect the ability of the catheter to travel along the guidewire. For example, the larger the annular space between the outer diameter of the guidewire and the inner diameter of the catheter, the greater the amount of radial play the catheter may experience and the more difficult it may be to navigate the catheter over the guidewire. With excessive radial play, the distal end of the catheter may have a higher risk of catching against vasculature or other anatomy of the patient rather than smoothly following along the guidewire path.
Often, a guidewire size is selected to minimize the amount of annular space between the guidewire and a given catheter size required or desired for a particular procedure, and to thereby limit the types of issues described above. Some devices include a flexible elongated member extending along and encompassing the distal section of the guidewire with an outer diameter near that of the inner diameter of the catheter so as to reduce radial play. However, a challenge exists in that a catheter has a propensity to catch on the elongated member when translating from the proximal section to the distal section of the guidewire. A guidewire wherein the proximal section has a substantially similar diameter as the elongated member would help to ameliorate the propensity of the catheter to catch at the proximal-distal transition of the guidewire. However, previous designs have not been able to do so without sacrificing flexibility or tensional transmission.
What is needed, therefor, is a guidewire device capable of being manufactured with a relatively large outer diameter along the complete length of the guidewire, that minimizes the annular space between the guidewire and certain sizes of compatible catheters, and that is also capable of providing sufficient flexibility and torquability. A catheter would more easily travel along such a guidewire, decreasing surgical complications, potential injury, and operation time.
Disclosed is an intravascular device, comprising a core having a proximal and a distal section, a first tube having a proximal and a distal section wherein the first tube is coupled to the core such that the distal section of the core passes into and is encompassed by the tube structure of the first tube, and a second tube having substantially the same outer diameter as the first tube, wherein the second tube is coupled to the core such that the proximal section of the core passes into and is encompassed by the tube structure of the second tube. Optionally, a portion of the proximal section of the first tube passes into and is encompassed by the second tube.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.
Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:
The core 102 and the tube 108 are typically formed from different materials. For example, the tube 108 is preferably formed from a relatively flexible and elastic material such as nitinol, whereas the core 102 may be formed from a relatively less flexible and less elastic material such as stainless steel. Forming the core 102 from stainless steel may be advantageous because it allows the distal tip to hold a shape when selectively bent/shaped by an operator and because stainless steel provides sufficient modulus of elasticity to provide more responsive translational movement. While these materials are presently preferred, other suitable materials such as polymers or other metals/alloys may also be utilized.
The tube 108 is coupled to the core 102 (e.g., using adhesive, soldering, and/or mechanical fixture) in a manner that beneficially allows torsional forces to be transmitted from the core 102 to the tube 108 and thereby to be further transmitted distally by the tube 108. A medical grade adhesive or other suitable material may be used to couple the tube 108 to the core wire 102 at the distal end of the device to form an atraumatic covering.
The outer tube 108 may include a cut pattern that forms fenestrations 110 in the tube 108. The pattern of fenestrations 110 can include axially extending “beams” and circumferentially extending “rings” as shown, and/or may be arranged to provide desired flexibility characteristics to the tube 108, including the promotion of preferred bending directions, the reduction or elimination of preferred bending directions, or gradient increases in flexibility along the longitudinal axis, for example. Examples of cut patterns and other guidewire device features that may be utilized in the guidewire devices described herein are provided in detail in U.S. Pat. No. 11,369,351, which is incorporated herein by reference in its entirety. Other slot or fenestration patterns may additionally or alternatively be utilized.
The guidewire device 100 can have a length for reaching to a targeted anatomical area. The guidewire device 100 typically has a length ranging from about 50 cm to about 350 cm depending on particular application needs. The tube 108 may have a length ranging from about 20 cm to about 65 cm, more typically about 30 cm to about 55 cm, such as about 35 cm to about 45 cm.
The guidewire device 100 may have a diameter of about 0.014 inches to about 0.035 inches, though larger or smaller sizes may also be utilized depending on particular application needs, and the features of the present disclosure are not necessarily limited to certain guidewire sizes. Some embodiments may have outer diameter sizes corresponding to standard guidewire sizes such as 0.014 inches, 0.016 inches, 0.018 inches, 0.024 inches, 0.035 inches, or other such sizes common to guidewire devices.
The distal section 104 of the core 102 may taper to a diameter of about 0.002 inches, or a diameter within a range of about 0.001 to 0.005 inches. In some embodiments, the distal tip may be flattened (e.g., to a rectangular cross section) to further enhance bending flexibility while minimizing reductions in cross-sectional area needed for tensile strength. In such embodiments, the cross section may have dimensions of about 0.001 inches by 0.003 inches, for example. In some embodiments, the tube 108 has a length within a range of about 3 to 100 cm.
The core 202 also includes a proximal section 206 (synonymously referred to herein as the proximal core 206) that is disposed proximal of the outer tube 208 and is not inserted into the outer tube 208. The proximal core 206 may comprise a friction-lowering coating, such as polytetrafluoroethylene (PTFE) and/or other suitable coating materials. The tube 208 may also include a coating, preferably a suitable hydrophilic coating.
As shown, the outer diameter of the tube 208 may be larger than the outer diameter of the proximal core 206. In one example, the proximal core 206 has an outer diameter of about 0.018 inches, while the tube 208 has an outer diameter of about 0.024 inches. Other core and/or tube sizes may also be utilized, however. For example, the tube 208 may have an outer diameter that is about 15% to about 50% larger than the outer diameter of the proximal core 206, or about 20% to about 45% larger, or about 25% to about 40% larger, such as about 30% to about 35% larger.
As mentioned above, a larger outer diameter in the tube 208 can better match certain desired catheter sizes and thereby reduce the amount of annular space between the guidewire and catheter during placement of the catheter over the guidewire. A larger outer diameter of the tube 208 reduces the likelihood the catheter will catch on the patient's vasculature. This is particularly beneficial at the more distal sections of the guidewire, which are more likely to be navigated through deeper, more tortuous portions of the patient's vasculature.
However, increasing the diameter of the proximal section 206 of the core 202 to match the larger diameter of the tube 208 may make the core 202 too stiff for use in certain desired applications. Thus, maintaining a smaller proximal section 206 of the core 202, while increasing the size of the tube 208 relative to the core 202, allows use of the more flexible core 202 while still enabling the benefits of a larger tube 208 at the distal sections of the guidewire 200.
However, because tube 208 may have a significantly larger diameter than core 202, a ledge 212 may form at the proximal end of tube 208, as shown in
Guidewire Devices with Uniform Diameters
Also illustrated is a second tube 314 encompassing the proximal section 306 of the core 302. The proximal section 306 of the core 302 is the portion that extends proximally from the first tube 308. The second tube 314 has a substantially similar outer diameter as the first tube 308. In some embodiments, as shown, the proximal end of the first tube 308 passes into and is encompassed by the distal end of the second tube 314 (or vice versa) such that a seamless transition is made from the second tube 314 to the first tube 308 without a significant change in outer diameter. Additionally, the second tube 314 may extend to the proximal end of the core 302, such that the diameter of the guidewire device 300 is substantially uniform along its complete length.
In some embodiments, the second tube 314 is formed from a relatively flexible and elastic material such as nitinol. The second tube 314 may also comprise a friction-lowering coating, such as polytetrafluoroethylene (PTFE) and/or other suitable coating materials. The second tube 314 may also include a coating, preferably a suitable hydrophilic coating. The second tube 314 may be prefabricated and threaded onto the core 302 and then bound to the core 302 using a weld, solder, adhesive, and/or other means of structural attachment.
In alternative embodiments, the second tube 314 is formed from a polymer material and is dip-coated, laminated, or otherwise applied onto the core 302. For example, the second tube 314 may be laminated to the core 302 through a reflow process, including the use of a heat-shrinkable fusing sleeve, such that the material forming the second tube 314 melts and bonds directly to the core 302, reducing the amount of adhesive needed to fabricate the guidewire device 300.
The second tube 314 can have a constant outer diameter, or as shown, a variable inner diameter. That is, the inner diameter can be larger at some points along the length of the second tube 314 and smaller at other points along the length of the second tube 314. A variable inner diameter can be beneficial because it allows close contact with the underlying proximal section 306 of the core 302 even if the proximal section 306 of the core 302 has a variable outer diameter, which can often be the case in order to impart desired flexibility/stiffness profiles and/or because of joints or connections within the structure of the proximal section 306 of the core 302.
Incorporating a second tube 314 on the guidewire device 300 provides several benefits. Because the diameter of the second tube 314 is substantially similar to the diameter of the first tube 308, a catheter will more smoothly track along the guidewire device 300. In particular, the transition from the proximal section to the distal section of the guidewire device 300 is greatly improved by internalizing the ledge 312 created by the first tube 308.
Further, because the second tube 314 comprises a softer material, the improvement in translating the catheter is obtained without compromising the overall flexibility of the guidewire device 300, as would have occurred if the proximal section of the core 302 were simply enlarged. In embodiments where the second tube 314 comprises a friction-lowering or hydrophilic coating, the above benefits are obtained while improving the ability of the guidewire device 300 to pass along and otherwise avoid harming the vasculature of the patient.
In this embodiment, the second tube 414 tube (e.g., a hypotube) may comprise a hollow lumen 416. The proximal end 407 of the core 402 passes into and is encompassed by the distal end of the second tube 414, with the proximal end of the core 402 passing into only a portion of the second tube 414. The distal end of the second tube 414 extends to the proximal end of the first tube 408, creating a smooth transition between the first tube 408 and the second tube 414.
In some embodiments, the proximal end of the first tube 408 may pass into and be encompassed by the distal end of the second tube 414 or vice versa. The proximal end of the core 402 may be secured to the distal end of the second tube 414 using a weld, solder, adhesive, and/or other means of structural attachment. The portion of the second tube 414 that is longitudinally coincident with the core 402 may be only 25% or less of the total length of the second tube 414, such as 20% or less, or 15% or less, or 10% or less, or 5% or less of the total length of the second tube 414.
The second tube 414 may comprise a metal, metal alloy, or other appropriate material suitable for use in a guidewire. Because torque transmission is a function of outer diameter, a metal tube presents comparatively good torsional transmission without suffering increased stiffness and decreased flexibility associated with wires having a solid metal core. A second tube 414 comprising metal may therefore provide suitable torquability, and a balance of stiffness and flexibility while retaining the benefits of a guidewire device 400 with a substantially uniform outer diameter.
The lumen 416 of the second tube 414 may optionally contain a filler used to provide luminal support to the second tube 414. The filler may comprise polyether block amide (PEBA) and/or other polymer, for example. Additionally, or alternatively, the filler may comprise a soft metal, or other material not significantly increasing the stiffness of the guidewire device 400. The filler may have a flexural modulus of approximately 1 MPa to approximately 1000 MPa, or approximately 100 MPa to approximately 900 MPa, or approximately 200 MPa to approximately 800 MPa, or approximately 300 MPa to approximately 700 MPa, or approximately 400 MPa to approximately 600 MPa, or approximately 500 MPa, or a range with endpoints defined by any two of the foregoing values.
The following list of clauses represents a non-exhaustive list of example embodiments according to the present disclosure.
Clause 1. An intravascular device, comprising: a core having a proximal section and a distal section; a first tube having a proximal section and a distal section, wherein the first tube is coupled to the core such that the distal section of the core passes into and is encompassed by the first tube; and a second tube having substantially the same outer diameter as the first tube, wherein the second tube is coupled to the core such that the proximal section of the core passes into and is encompassed by the second tube, wherein the second tube extends over at least 50% of the length of the proximal section of the core.
Clause 2. The intravascular device of clause 1, wherein the second tube extends over at least 75% of the length of the proximal section of the core.
Clause 3. The intravascular device of clause 1 or clause 2, wherein the second tube extends over substantially the complete length of the proximal section of the core.
Clause 4. The intravascular device of any preceding clause, wherein at least a portion of the proximal section of the first tube passes into and is encompassed by the second tube.
Clause 5. The intravascular device of any preceding clause, wherein the second tube has a lower elastic modulus than the first tube.
Clause 6. The intravascular device of any preceding clause, wherein the second tube comprises a polymer.
Clause 7. The intravascular device of any preceding clause, wherein the second tube is laminated to the proximal section of the core.
Clause 8. The intravascular device of any preceding clause, wherein the second tube has a variable inner diameter.
Clause 9. The intravascular device of clause 8, wherein the variable inner diameter is larger at a proximal section of the second tube and smaller at a distal section of the second tube.
Clause 10. The intravascular device of any one of clauses 1 through 5, wherein the second tube is optionally formed from metal.
Clause 11. The intravascular device of clause 10, wherein the second tube is a hypotube.
Clause 12. The intravascular device of clause 10 or clause 11, wherein the second tube extends farther proximally than the core such that a proximal end of the core terminates at a distal section of the second tube.
Clause 13. The intravascular device of clause 12, wherein at least a portion of a lumen of the second tube contains a filler.
Clause 14. The intravascular device of clause 13, wherein the portion of the lumen of the second tube containing the filler is not coincident with the core.
Clause 15. The intravascular device of clause 13 or clause 14, wherein the filler comprises a polymer.
Clause 16. The intravascular device of clause 15, wherein the filler comprises polyether block amide.
Clause 17. The intravascular device of any one of clauses 13 through 16, wherein the filler has an elastic modulus of 1 MPa to 1000 MPa, or 100 MPa to 900 MPa, or 200 MPa to 800 MPa, or 300 MPa to 700 MPa, or 400 MPa to 600 MPa, or 500 MPa.
Clause 18. The intravascular device of any one of clauses 13 through 17, wherein the filler comprises a metal.
Clause 19. The intravascular device of any one of clauses 10 through 18, wherein the first tube and the second tube contact each other at a joint, and wherein a proximal end of the core is disposed 0.5 cm to 5 cm proximal of the joint.
Clause 20. The intravascular device of clause 19, wherein an adhesive is disposed at the joint.
As used herein, the term “longitudinally coincident” (sometimes shortened to simply “coincident”) means two components that are both disposed at a given longitudinal position of the device and may, for example, overlap at least partially. For example, if a first component and a second component are longitudinally coincident, at least a portion of the first component overlaps with at least a portion of the second component at some location of the device.
While certain embodiments of the present disclosure have been described in detail, with reference to specific configurations, parameters, components, elements, etcetera, the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention.
Furthermore, it should be understood that for any given element of component of a described embodiment, any of the possible alternatives listed for that element or component may generally be used individually or in combination with one another, unless implicitly or explicitly stated otherwise.
In addition, unless otherwise indicated, numbers expressing quantities, constituents, distances, or other measurements used in the specification and claims are to be understood as optionally being modified by the term “about” or its synonyms. When the terms “about,” “approximately,” “substantially,” or the like are used in conjunction with a stated amount, value, or condition, it may be taken to mean an amount, value or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Any headings and subheadings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.
It will also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a singular referent (e.g., “widget”) may also include two or more such referents.
It will also be appreciated that embodiments described herein may also include properties and/or features (e.g., ingredients, components, members, elements, parts, and/or portions) described in one or more separate embodiments and are not necessarily limited strictly to the features expressly described for that particular embodiment. Accordingly, the various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features relative to a specific embodiment of the present disclosure should not be construed as limiting application or inclusion of said features to the specific embodiment. Rather, it will be appreciated that other embodiments can also include such features.
This application claims the benefit of and priority to U.S. Provisional Application No. 63/434,432, filed Dec. 21, 2022 and titled “MICRO-FABRICATED GUIDEWIRE DEVICES HAVING VARYING DIAMETERS MADE UNIFORM,” the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63434432 | Dec 2022 | US |
