Double Concentric Guidewire
20180214675 ยท 2018-08-02
Inventors
Cpc classification
A61M2025/09116
HUMAN NECESSITIES
International classification
Abstract
A double guide wire includes two guidewires deployed concentrically, one within the other. Each guidewire is formed as an elongated flexible shaft having a distal portion including a deflectable helical coil terminating at a distal tip. The first guidewire is implemented as a hollow guidewire having a central lumen extending along its length, while the second guidewire is configured as a smaller gauge guidewire deployed within the central lumen of the first guidewire. An adjuster mechanism allows the inner guidewire to be advanced and retracted relative to the outer guidewire, transforming the guidewire between: a first state in which the distal tip of the second guidewire is adjacent to the distal tip of the first guidewire; and a second state in which at least part of the distal portion of the inner guidewire is advanced beyond distal tip of the first guidewire.
Claims
1. A double guidewire comprising: (a) a first guidewire comprising an elongated flexi shaft having a distal portion that terminates in a distal tip, said distal portion comprising a deflectable helical coil, said first guidewire being a hollow guidewire having a central lumen extending along a length of said first guidewire; (b) a second guidewire comprising an elongated flexible shaft having a distal portion that terminates in a distal tip, said distal portion comprising a deflectable helical coil, said second guidewire being deployed within said central lumen of said first guidewire; and (c) an adjuster mechanism mechanically linked to proximal portions of said first and second guidewires, said adjuster mechanism being operable to displace said second guidewire longitudinally relative to said first guidewire between: (i) a first state in which said distal tip of said second guidewire is adjacent to said distal tip of said first guidewire, and (ii) a second state in which at least part of said distal portion of said second guidewire s advanced beyond distal tip of said first guidewire.
2. The double guidewire of claim 1, wherein said adjuster mechanism is further operable to displace said second guidewire longitudinally relative to said first guidewire to a third state in which said distal tip of said second guidewire is withdrawn proximally along said central lumen so as to leave empty a part of said central lumen along at least part of said distal portion of said first guidewire.
3. The double guidewire of claim 2, wherein a region of said distal portion adjacent to said distal tip of each of said first and second guidewires is configured to be inelastically deformable or preshaped to impart a lateral deflection to said distal portion, and wherein, when a first length of said distal portion adjacent to said distal tip of each of said first and second guidewires is deflected, partial withdrawal of said second guidewire from said first state towards said third state causes a second length of the double guidewire to be deflected, said second length being longer than said first length.
4. The double guidewire of claim 1, wherein an external surface of said distal portion of said first guidewire is coated with a hydrophilic coating, and wherein an external surface of said distal portion of said second guidewire is not coated with said hydrophilic coating.
5. The double guidewire of claim 1, wherein said first guidewire further comprises a metal strip extending along an inner surface of said helical coil and permanently attached to said helical coil at a plurality of spaced-apart locations along said helical coil.
6. The double guidewire of claim 1, wherein said second guidewire further comprises a tapered metal core extending within said helical coil and permanently attached to said helical coil at said distal tip.
7. The double guidewire of claim 1, wherein an outer diameter of said first guidewire is sized for use with 014 compatible over-the-wire devices.
8. The double guidewire of claim 1, wherein an outer diameter of said first guidewire is sized for use with 038 compatible over-the-wire devices.
9. A method of performing a surgical procedure on a patient comprising the steps of: (a) providing a double guidewire according to claim 1 with a region of said distal portion adjacent to said distal tip of each of said first and second guidewires having a lateral deflection, the deflected portion of said first guidewire having a first length; (b) introducing the double guidewire into the vascular system of the patient and navigating the double guidewire within the vascular system to reach a location of a lateral branch vessel; and (c) selectively displacing said second guidewire relative to said first guidewire so as to locate deflected portions of said first and second guidewires longitudinally displaced relative to each other, thereby imparting to said double guide wire a lateral deflection extending for a second length, said second length being greater than said first length, to facilitate navigation of said double guidewire into the lateral branch vessel.
10. The method of claim 9, further comprising selectively displacing said second guidewire relative to said first guidewire so that said distal portion of said second guidewire extends beyond said distal tip of said first guidewire.
11. The method of claim 9, further comprising advancing along the double guidewire an 014-compatible over-the-wire device selected from the group consisting of: an angioplasty balloon and an expandable stent.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] The present invention is a double concentric guidewire.
[0046] The principles and operation of guidewires according to the present invention ma be better understood with reference to the drawings and the accompanying description.
[0047] By way of introduction, it should be noted that certain preferred embodiments of the present invention are distinguished by providing a double guide wire in which two guidewires, each providing a set of features required of a guidewire, are deployed concentrically, one within the other. Thus, each is formed as an elongated flexible shaft having a distal portion that terminates in a distal tip, where the distal portion includes a deflectable helical coil. The helical coil is a critical feature of the distal portion of a guidewire, providing a combination of an easily deflectable structure which can readily negotiate meandering paths while at the same time allowing application of considerable axial force when the coils of the coil are closed against each other. The first guidewire is implemented as a hollow guidewire having a central lumen extending along its length, e the second guidewire is configured as a smaller gauge guidewire deployed within the central lumen of the first guidewire.
[0048] An adjuster mechanism, which is typically implemented as a manually-controlled slider integrated with a handle of the double guidewire, allows the second, guidewire to be advanced and retracted relative to the first, outer guidewire, thereby providing the user with a range of variations of the properties of the guidewire tip which can typically otherwise only be achieved by swapping guidewires (removing the first one from the body and inserting an alternative one), with all the disadvantages of such replacement as discussed above. Specifically, by operating the adjuster mechanism, the user can preferably transform the guidewire at will between two or more of the following states: [0049] A first state (
[0052] The ability to switch between the first and second states described above allows the user to swap as desired between other properties that may be provided by the first and second guidewires. For example, according to one particularly preferred non-limiting example, the external surface of the distal portion of the first (outer) guidewire is coated with a hydrophilic coating, while the external surface of the distal portion of the second (inner) guidewire is not coated with the hydrophilic coating, being either uncoated or having some other coating, such as a hydrophobic coating. This facilitates smooth insertion of the guidewire in the first state, where the properties distal end of the guidewire are defined by the outer guidewire, and the hydrophilic coating ensures greatly reduced friction compared to an uncoated guidewire. When the user is approaching the target location or otherwise needs enhanced tactile feedback, the relatively higher friction second guidewire is advanced so that the outer surface without a hydrophilic coating becomes the leading exposed guidewire surface, thereby providing the desired enhanced tactile feedback.
[0053] In order to maintain the structural integrity of the first (outer) guidewire and as a safety feature, the first guidewire preferably includes a metal strip (shaping ribbon) extending along an inner surface of the helical coil and permanently attached (e.g., welded) to the helical coil at a plurality of spaced-apart locations along the helical coil.
[0054] The inner (second) guidewire is preferably formed with a tapered metal core that extends within the helical spring, and is permanently attached (e.g., welded) to the helical coil at the distal tip. The tapering of the metal core inherently provides gradually varying stiffness to the second guidewire, where the distal end is the most floppy part, becoming gradually stiffer with increasing distance from the tip.
[0055] The double guidewire of the present invention may be used to advantage in a wide range of applications. By way of one particularly preferred set of application, the double guidewire is used in procedures performed in the coronary arteries. For such applications, an outer diameter of the first (outer) guidewire is sized for use with 014 compatible over-the-wire devices, i.e., with an outer diameter no greater than about 0.014 inch (0.36 mm).
[0056] In other applications in the peripheral vascular system, implementations of the invention may employ an outer diameter of the first (outer) guidewire sized for use with 038 compatible over-the-wire devices, i.e., with an outer diameter no greater than about 0.038 inch (0.97 mm).
[0057] A preferred embodiment of the invention as illustrated in
[0058] The Guide Wire (100) is hollow and has a distal portion (110) terminating at a distal tip (111) and a proximal portion (120) associated with a handle (200).
[0059] As illustrated in
[0060] According to
[0061] Attachment of the metal strip at spaced-apart locations along the guidewire may be achieved by temporarily pressing the strip against the internal surface of the outer guidewire by temporary insertion of an inner rod formed from or coated with a non-stick coating, such as Teflon (PTFE), thereby pressing the strip outwards against the inner surface of the outer guidewire, and then employing a suitable bonding technique, such as welding, to form a permanent connection between the outer guidewire and the metal strip. The temporary inner rod is then removed and the inner guidewire is introduced.
[0062] The proximal portion (120) is associated with a handle (200). Its proximal end is held by the handle (200) such that it can be turned about its longitudinal axis by using the handle as a torquer. According to a preferred embodiment illustrated in
[0063] Turning back to
[0064] By rotating the Guide Wire (100) and by moving it axially the floppy tip moves along the vessels walls. Once the tip reaches the ostium (opening) of a branch in the vascular system it falls into the branch. In this situation, pushing the Guide Wire (100) further will cause the tip (111) to advance along the branch. Using this method the physician can steer the distal tip (111) to almost any desired location in the vascular system.
[0065] The hollow Guide Wire (100) defines a lumen (150) extending along its entire length from the proximal end (122) of the proximal portion (120) to the distal end (115) of the tip (111) of the distal portion (110). In preferred embodiments illustrated in
[0066] As illustrated in
[0067] As illustrated in
[0068] The proximal portion (320) of the second guide wire (300) is associated with side handle (200) by a slider member (210). The proximal end (321) is attached to the slider by using welding soldering, adhering or any other suitable method. By sliding the slider member (210) along the handle (200) the physician can displace the second inner guide wire (300) within the lumen (150) of the Guide Wire (100).
[0069] The distal tip (311) of the second guide wire is configured to protrude out of the distal tip (111) of the Guide Wire by manipulating the handle (200). As illustrated in
[0070] The second, inner guide wire is of small diameter that can vary from 0.005 to 0.024 depending on the Guide Wire (100) outer diameter. In a preferred embodiment the diameter of at least a distal portion of the second guidewire (300) is smaller than 0.014, and in certain particularly preferred implementations, 0.0070.002. This renders the inner guidewire particularly suitable to allow the physician to negotiate the thin micro channels of the proximal cap of a CTO lesion in order to cross through.
[0071] As illustrated in
[0072] In another preferred embodiment of the invention illustrated in
[0073] The embodiments of the guide wire described herein are preferably in the same sizes as a conventional guide wires. Hence the diameter of the Guide Wire (100) is 0.038 or smaller with respect to the conventional sizes of 0.038, 0.024, 0.018 and 0.014.
[0074] Balloon dilatation catheters for percutaneous transluminal coronary angioplasty (PTCA) and percutaneous transluminal angioplasty (PTA) are usually intended to be introduced over a 0.014 guide wires, referred-to herein as 014 compatible. Therefore if the Guide Wire (100) of the present invention is intended to facilitate the placement of Balloon dilatation catheters during those procedures it is of advantage that the Guide Wire is 0.014 or smaller.
[0075] It is well accepted among interventional cardiologist physicians that workhorse guide wires (guide wires that intended to be the first to negotiate the coronary vessels for navigation during PTCA procedures) should be coated with a hydrophilic coating to reduce surface friction to enhance trackability. It is also well accepted that the distal tips of guide wires that are intended to negotiate with CTO should not be coated because the hydrophilic coating disturbs the tactile sense the physician has regarding the position of the guide wire within the lesion.
[0076] It would be of advantages to have a single tool that offers the physician an option to navigate to the CTO lesion with a hydrophilic tip and then negotiate the CTO with an uncoated tip. Therefore in the preferred embodiments illustrated in
[0077] As illustrated in
[0078] By using the slider (210) to displace the tip (311) of the second inner guide wire (300) within the distal portion (110) of the Guide Wire (100) the physician adjust the stiffness and curvature of the distal tip (111) of the Guide Wire (100) on demand. Hence by using the device of the present invention, the physician can immediately change the character of the Guide Wire he or she currently use from floppy to stiff and vice versa with no need to switch between wires.
[0079] In the preferred embodiment illustrated in
[0080] In order to make the tip (311) protrude out of the Guide Wire (100) the physician turns the ring as illustrated in V2 of
[0081] In a preferred embodiment illustrated in
[0082] The distal tip (311) of the second guide wire thus induces a second curve (111b) in the outer guidewire at a corresponding position along the outer guidewire, thereby allowing adjustment of the shape of the tip of the Guide Wire by manipulating the slider (210) of the handle (200). In other words, the presence of the bent tip of inner guidewire within the flexible distal portion of the outer guidewire generates an additional region of deflection which can be displaced relative to the outer guidewire by operating slider (210), thereby adjusting the overall extent, angle and geometry of the curvature of the tip portion of the double guidewire.
[0083] The effect of this feature is illustrated in
[0084] As illustrated in
[0085] The various features of the device of the invention described herein thus provide various improvements to the efficacy of devices for opening CTO lesions and other vascular applications in the coronary and peripheral vascular systems, typically offering time saving and/or reduced risk of perforating the artery compared to conventional techniques.
[0086] To the extent that the appended claims have been drafted without multiple dependencies, this has been done only to accommodate formal requirements in jurisdictions which do not allow such multiple dependencies. It should be noted that all possible combinations of features which would be implied by rendering the claims multiply dependent are explicitly envisaged and should be considered part of the invention.
[0087] It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.