Guide wire and microcatheter

Abstract

A medical guidewire for improving vascular navigation (i.e. To blood clots, aneurysms, or hemorrhagic stroke) includes a guidewire having a curvilinear distal tip, a shaft covering at least a portion of the guidewire, and a coil affixed covering a portion of the guidewire proximal to the distal tip and distal to the shaft. Linear movement of the shaft toward the coil experiences compression of the coil and rotates the distal tip. A microcatheter includes a tube having an axially collapsible braided distal portion. The braided distal portion may include a mixture of thicker strands and thinner strands. And when the mechanism is triggered to fold, the outer diameter of the knitting part is increased. The mechanism may be an actuator on the guidewire that, when pulled, exerts an axial pressure (directly or indirectly) on the distal end of the knitted portion. Near blood clots may be captured, and the microcatheter is removed with the blood clots.

Description

Technical Field

[0001] The present invention belongs to the field of medical guidewires and microcatheters and assemblies of such guidewires and microcatheters. Background Art

[0002] Doctors may need to navigate blood vessels in the brain for a variety of reasons. One reason is to reach and remove an ischemic blood clot. Another reason is to reach and treat the area of ​​a hemorrhagic stroke. A third reason is to reach and treat an aneurysm, in which a bulge forms in a blood vessel caused by a weakness in the vessel wall, usually at the site of a blood vessel branch.

[0003] The amount of time from the formation of a blood clot, such as an ischemic (stroke) clot, to its removal is clinically effective and is limited. For acute stroke, clot removal is standard care if it is performed within the first 6 hours after symptom onset. From 6 hours to 24 hours the evidence is less clear whether this is the optimal course of care.

[0004] Guided by real-time imaging of the blood vessels, surgeons must navigate a catheter within the blood vessels to an artery in the brain and then carefully remove the clot using a variety of devices, including suction and / or a stent-like device. The procedure takes time and typically doesn't begin until about three hours after the patient notices symptoms.

[0005] When a symptomatic patient comes to the emergency room, it takes time to gather information, run CT images, inject the patient with imaging contrast material, interpret the images to find the problem, and hand the patient over to the surgeon. This often takes about 3 hours. Therefore, the amount of time for the surgeon to reach the vessel to perform a clinically effective intervention is limited. Summary of the invention

[0006] Applicants have determined that many blood vessels in which a blood clot or aneurysm or hemorrhagic stroke must be reached by a surgeon are difficult to reach because the blood vessels may be tortuous, looped, or bifurcated. As a result, the process of navigating a surgeon to a desired area of ​​a blood vessel for clinical intervention is extremely difficult. As a result, surgeons often spend a significant amount of time, sometimes hours, navigating a blood vessel with a guidewire, catheter, or microcatheter just to reach the problem area or location in the blood vessel.

[0007] One embodiment is a medical guidewire for improving vascular navigation, comprising: a wire having a curved distal tip; a shaft covering at least a portion of the wire; and a coil attached to cover a portion of the wire proximal to the distal tip and distal to the shaft, wherein linearly moving the shaft toward the coil causes the coil to experience compression and rotate the distal tip.

[0008] In some embodiments, moving the shaft linearly away from the coil causes the coil to be released and causes the distal tip to rotate in the opposite direction.

[0009] In some embodiments, the compression experienced by the coil causes the distal tip to rotate up to 720 degrees.

[0010] In some embodiments, the compression experienced by the coil causes the distal tip to rotate an amount of rotation between 90 and 720 degrees.

[0011] In some embodiments, the distal tip is radiopaque.

[0012] In some embodiments, the radius of the distal tip is about 3 mm.

[0013] In some embodiments, the guidewire further comprises a tube within the shaft.

[0014] In some embodiments, the coil is made from a metal alloy of nickel and titanium.

[0015] In some embodiments, the guidewire is combined with a microcatheter.

[0016] In some embodiments, the wire is substantially straight except for the curved distal tip.

[0017] Another embodiment is a microcatheter and guidewire assembly comprising: a microcatheter including a tube having an axially retractable braided distal portion; a guidewire within the microcatheter and including a wire having a mechanism at a distal end configured to actuate axial retraction of the braided distal portion of the microcatheter.

[0018] In some embodiments, the braided distal portion has a first outer diameter in the expanded position and a second outer diameter in the collapsed position, such that the second outer diameter is greater than the first outer diameter.

[0019] In some embodiments, the braided distal portion has a maximum first outer diameter in the expanded position and a maximum second outer diameter in the collapsed position, such that the maximum second outer diameter is greater than the maximum first outer diameter. In some embodiments, the maximum second outer diameter is at least twice the maximum first outer diameter.

[0020] In some embodiments, the braided distal portion has an average first outer diameter in the expanded position and a maximum second outer diameter in the collapsed position, such that the maximum second outer diameter is at least twice the average first outer diameter.

[0021] In some embodiments, the mechanism includes a flange, protrusion, or annular projection such that pulling the guidewire proximally causes the flange, protrusion, or annular projection to press against (i) the distal end of the braided distal portion or (ii) the distal end of a portion distal to the braided distal portion.

[0022] In some embodiments, the braided distal portion includes a mixture of thicker strands and thinner strands.

[0023] In some embodiments, the braided distal portion includes a symmetrical mixture of thicker strands and thinner strands.

[0024] In some embodiments, the braided distal portion includes a first braided portion and a second braided portion separated by a non-braided portion.

[0025] In some embodiments, the guidewire has a curved distal tip, the guidewire further comprising a shaft covering at least a portion of the guidewire and a coil attached to cover a portion of the wire proximal to the distal tip and distal to the shaft, wherein linearly moving the shaft toward the coil causes the coil to experience compression and rotate the distal tip.

[0026] In some embodiments, the braided distal portion comprises a metal alloy of nickel and titanium.

[0027] In some embodiments, the braided distal portion is configured to capture a blood clot next to the braided distal portion when the microcatheter is in a blood vessel.

[0028] In some embodiments, the guidewire is substantially straight except at the curved distal tip of the guidewire.

[0029] Another embodiment is a microcatheter that includes a tube having an axially collapsible braided distal portion.

[0030] In some embodiments, the braided distal portion includes a mixture of thicker strands and thinner strands.

[0031] In some embodiments, the braided distal portion includes a first braided portion and a second braided portion separated by a non-braided portion.

[0032] In some embodiments, the braided distal portion is configured to capture a blood clot next to the braided distal portion when the microcatheter is in a blood vessel.

[0033] In some embodiments, the braided distal portion has a first outer diameter in the expanded position and a second outer diameter in the collapsed position, such that the second outer diameter is greater than the first outer diameter.

[0034] In some embodiments, the braided distal portion has a maximum first outer diameter in the expanded position and a maximum second outer diameter in the collapsed position, such that the maximum second outer diameter is greater than the maximum first outer diameter. In some embodiments, the maximum second outer diameter is at least twice the maximum first outer diameter.

[0035] In some embodiments, the braided distal portion has an average first outer diameter in the expanded position and a maximum second outer diameter in the collapsed position, such that the maximum second outer diameter is at least twice the average first outer diameter.

[0036] In some embodiments, the braided distal portion comprises a metal alloy of nickel and titanium.

[0037] Another embodiment is a method for inserting a guidewire into a blood vessel containing a difficult-to-navigate portion, the method comprising inserting a guidewire into the blood vessel, wherein the guidewire comprises a wire having a curved distal end, and comprises a shaft covering a portion of the wire and a coil attached to cover a portion of the wire proximal to the distal end and distal to the shaft; navigating the curved, looped, or bifurcated portion of the blood vessel by linearly moving the shaft toward the coil to compress the coil, the compression causing the distal end to rotate to reach one of a blood clot, an aneurysm, and a hemorrhagic stroke.

[0038] Another embodiment is a method for removing a blood clot from a blood vessel of a mammalian subject, comprising inserting a microcatheter over a guidewire into the blood vessel, the microcatheter having an axially retractable braided distal portion so that the distal end of the guidewire extends further than the distal end of the microcatheter; and pulling the guidewire proximally so that a mechanism on the guidewire triggers axial retraction of the braided distal portion.

[0039] In some embodiments, the method further comprises axially gathering the braided distal portion to capture a blood clot outside the microcatheter. In some embodiments, the method further comprises withdrawing the catheter having the blood clot.

[0040] In some embodiments, the mechanism comprises a flange, a protrusion, or an annular projection that presses against a distal end of: (i) the braided distal portion or (ii) a portion distal to the braided distal portion.

[0041] In some embodiments, the guidewire includes a wire having a curved distal tip, a shaft covering a portion of the wire, and a coil attached to cover a portion of the wire proximal to the distal tip and distal to the shaft, such that linear movement of the shaft compresses the coil and rotates the distal tip.

[0042] Another embodiment is a method of treating an aneurysm, comprising inserting a guidewire into a blood vessel, the guidewire comprising a guidewire having a curved distal tip and comprising a shaft covering a portion of the guidewire and a coil attached to cover a portion of the guidewire proximal to the distal tip and distal to the shaft; navigating a curved, looped, or bifurcated portion of the blood vessel to reach the aneurysm by linearly moving the shaft toward the coil to compress the coil, the compression rotating the distal tip; and inserting a microcatheter and treating the aneurysm using one of (i) endovascular coil embolization, (ii) a covered stent, and (iii) a biologic graft.

[0043] Another embodiment is a system for navigating difficult-to-navigate blood vessels, comprising: a robot comprising at least one motor and an actuator; an input device; a microcatheter and guidewire assembly comprising: a microcatheter comprising a tube having an axially retractable braided distal portion; a guidewire within the microcatheter and comprising a wire having a mechanism at the distal end configured to actuate axial retraction of the braided distal portion of the microcatheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Various embodiments are described herein by way of example only, with reference to the accompanying drawings, in which:

[0045] Figure 1 is a perspective view of a guidewire according to one embodiment;

[0046] Figure 2 is a side view of a guidewire according to one embodiment showing the shaft in a neutral position, the shaft positioned for linear movement to compress the coil and rotate the distal tip;

[0047] Figure 3 is a side view of a guidewire according to one embodiment showing the shaft having compressed the coil and rotated the distal tip and in a position for releasing the coil and rotating the distal tip in an opposite direction;

[0048] Figure 4 is a side view of a microcatheter according to one embodiment showing a braided portion in a deployed position;

[0049] Figure 5 According to an embodiment Figure 4 A side view of a microcatheter showing a braided portion in an axially collapsed position;

[0050] Figure 6 is a side view of a guidewire according to one embodiment showing detailed components thereof;

[0051] Figure 7 According to one embodiment, Figure 6 A cross-sectional view taken along line CC;

[0052] Figure 8 According to an embodiment Figure 6 An enlarged view of detail A;

[0053] Fig. 9 is an enlarged view of a coil of a guidewire according to one embodiment;

[0054] Fig.10 is a flow chart of a method according to one embodiment;

[0055] Fig.11 is a flow chart of another method according to one embodiment;

[0056] Fig.12 is a flow chart illustrating yet another method according to one embodiment;

[0057] Fig.13 is a schematic diagram of a system according to one embodiment. DETAILED DESCRIPTION

[0058] The following detailed description is of the best mode currently contemplated for carrying out the invention. The description is not to be considered in a limiting sense, but is made only for the purpose of illustrating the general principles of the embodiments, and the scope of the invention is best defined only by the appended claims.

[0059] Certain embodiments generally provide a guidewire for navigating difficult-to-navigate blood vessels. Certain embodiments provide a microcatheter for use with the guidewire or another guidewire. In certain embodiments, there is an assembly of a guidewire and a microcatheter.

[0060] Guidewires are used to navigate difficult to navigate vessels, such as looped, curved or bifurcated vessels. The navigation may be to reach a blood clot in preparation for removal of the blood clot, to reach the area of ​​an aneurysm or hemorrhagic stroke in preparation for repairing an aneurysm or treating a hemorrhagic stroke or another intervention with the aid of a microcatheter.

[0061] For surgeons, positioning guide wires and microcatheters at target points in blood vessels, such as at blood clots, aneurysms, or hemorrhagic strokes, can be a difficult task. The sooner the surgeon reaches the target point and sets the microcatheter there, the sooner the clinical intervention is effective. The amount of time that passes before clinical intervention directly affects the clinical outcome. The surgeon may inadvertently pass through the junction of bifurcated vessels and need to correctly withdraw and partially correctly re-navigate. Alternatively, the surgeon may reach the desired position but let it slip. The surgeon then needs additional manipulation, which takes up valuable time.

[0062] One embodiment is a guide wire, which includes a wire with a curved distal end, such as a substantially straight wire, and a mechanism for converting the linear motion of the distal end into a rotational motion. For example, the guide wire may include a shaft covering at least a portion of the guide wire and a coil attached to cover the distal end of the guide wire near the distal end and a portion of the shaft distal. It is not necessary to rotate the end of the guide wire (or microcatheter) by means of the rotational motion of the more proximal part of the guide wire, which may be difficult, but the shaft of the guide wire is configured to move linearly toward the coil, for example. The linear motion is configured to apply an axial compression force to compress the coil, so that the distal end rotates automatically. The rotation of the distal end enables the guide wire to enter an inaccessible space in a blood vessel. This makes it significantly easier to efficiently navigate difficult-to-navigate blood vessels (such as bifurcated, looped or curved blood vessels). Therefore, a large amount of time is saved for surgeons.

[0063] The guidewire is used with the microcatheter and is placed before the microcatheter is placed. In this case, in addition to the novel guidewire, a novel microcatheter is also provided, as described below. Therefore, the embodiments of the novel guidewire described herein can be used with non-braided microcatheters, or they can be combined with the embodiments of the novel braided microcatheters described herein. Similarly, the embodiments of the braided microcatheters described herein can be used with a guidewire that has a feature of a mechanism for triggering the retraction of the braid of the microcatheter, or has a feature of linear motion of the shaft that causes the distal end to rotate, or has both of these features (or if there is some other mechanism that can trigger the retraction of the braid without the need for a guidewire, the guidewire may not have any of the above features).

[0064] The microcatheter can be a braided microcatheter. The microcatheter can include a braided portion. The microcatheter can have a braided distal portion that can be axially retracted when compression is applied when the mechanism is triggered. Once the guidewire is in place, the microcatheter can be positioned to be sleeved on the guidewire. In a non-limiting example of the mechanism, the distal end of the guidewire can extend out of the distal end of the microcatheter. By pulling the guidewire backward (proximally), the mechanism (e.g., a mechanism on the guidewire) can trigger the compression of the braided portion of the microcatheter. For example, when the guidewire is pulled back in the proximal direction, the actuator on the guidewire can press against the distal end of the braided section of the microcatheter. In a non-limiting embodiment thereof, the flange, protrusion, or protrusion on the distal portion of the guidewire can press against the distal end of the braided section of the microcatheter (or against the portion distal to the braided section) to generate a compressive force that causes the braided portion of the microcatheter to axially retract. Axial retraction can cause the outer diameter of all or part of the braided portion of the microcatheter to increase. When the braided portion bulges outward due to the axial contraction, a blood clot near the microcatheter can be hooked and captured by the braided strands of the braided section of the microcatheter. Therefore, when the microcatheter is then removed from the blood vessel, the blood clot can be "dragged" along with it and automatically removed with the microcatheter.

[0065] In the case of an aneurysm or hemorrhagic stroke, the advantage of a guidewire is to navigate difficult-to-navigate vessels and quickly reach the desired location, i.e., the aneurysm or hemorrhagic stroke, in order to initiate treatment.

[0066] The entire procedure using the guidewire and microcatheter (or each alone) can be guided by the intelligent robot. In this case, the surgeon is able to control the robot with a joystick or other input device. Thus, the surgeon can distance himself from X-rays or other imaging (e.g., by being located in a location separated from the actual device by a wall) that can be taken during the procedure using a radiopaque distal tip or catheter braid.

[0067] Unless otherwise specified, the term "about" as used herein means plus or minus 10%. For example, "about X millimeters" means between 0.9x and 1.1x millimeters.

[0068] The term "straight wire" as used herein in any embodiment refers to a guidewire that is essentially straight (except for portions of the guidewire that are specifically described as not being straight, such as the curved end) in its natural position, for example, before use. Its "natural position" refers to the position when it is fully opened to its maximum length and placed on a flat surface without being subjected to external forces (except ambient air) that stretch or bend it. This of course does not exclude the fact that such an essentially straight guidewire can be curved or bent well when inserted into a curved or tortuous blood vessel.

[0069] The principles and operation of the guidewire and microcatheter may be better understood with reference to the drawings and accompanying description.

[0070] like Figures 1 to 12 , especially Figures 1 to 3 and Figures 6 to 9 As shown in , a medical guidewire 10 for improving vascular navigation may include a wire. In one non-limiting embodiment, the wire is a substantially straight wire 10a (except for portions specifically described as not being substantially straight). The guidewire 10 may have a curved distal tip 20. In some cases, the distal tip 20 is curved in a manner such that it is j-shaped, such as Figure 1 and Figure 2 In some embodiments, other curved shapes of the distal tip 20 may exist. Figure 8 As shown in , the radius of the distal end can be about 3 mm. However, depending on the expected position or other factors, the radius can vary. In addition, the Shore hardness and / or Young's modulus of the distal end 20 can also vary.

[0071] The guidewire 10 may also include a shaft 30 covering at least a portion of the wire 10 .

[0072] The coil 40 can be attached to cover the portion of the wire 10 proximal to the distal tip 20 and distal to the shaft 30. In some embodiments, the coil 40 is made of a metal alloy of nickel and titanium, such as Nitinol. The proximal portion of the working element 40 (coil 40) and the entire guidewire can be slightly less rigid than the rest of the guidewire 10 and thus can be slightly less straight, but in some embodiments is still substantially straight.

[0073] As from Figure 1 and Figure 2 As can be seen, the shaft 30 can be configured to move linearly toward the coil 40 in order to compress the coil. This compression can cause a torque that can cause the distal tip 20 to rotate.

[0074] In some cases, full compression may cause distal tip 30 to rotate up to 720 degrees. In other embodiments, the amount of rotation induced can be 30-60, 60-90, 90-120, 120-150, 150-180, 180-210, 210-240, 240-270, 270-300, 300-330, 330-360, 390-420, 420-450, 450-480, 480-510, 510-540, 540-570, 570-600, 600-630, 630-660, 660-690, or 690-720 degrees of rotation or any combination of the minimum and maximum amounts within any of these ranges (e.g., up to 30 to 720 degrees or up to 90 to 270 degrees or 90 to 600 or up to 120 to 630 or 30 to 90).

[0075] like Figure 3 As shown in , in some embodiments, the linear motion of the shaft 30 is reversed by loosening the shaft 30 after moving the shaft distally toward the coil 40, releasing the compressive force on the coil 40 and causing the distal tip 20 to rotate in the opposite direction by any of the amounts listed above for the initial rotation.

[0076] In some embodiments, distal tip 20 is radiopaque. For example, distal tip 20 may be made of a platinum-iridium alloy that allows distal tip 20 to be clearly seen in images of X-ray, CT, MRI, or other imaging techniques.

[0077] In some embodiments, the guidewire 10 further includes a tube 35 inside the shaft 30 along all or a portion of the length of the shaft 30 , such as a proximal tube 35 .

[0078] The guidewire 10 can be constructed in a novel way, such as using a combined UV glue or welding laser to attach the coil 40 (or working element 40) to, for example, the distal tube 37 (which can be on the inside of the coil 40), so that when the shaft 30 presses the coil 40, the coil 40 can still compress and expand. This is just an embodiment. In another non-limiting embodiment, the glue or welding laser connection between the coil 40 and the distal tube 37 can be located on the end of the coil 40 (working element 40), so that the area between the two ends of the coil 40 can change length due to compression.

[0079] In some embodiments, the guidewire 10 is combined with a microcatheter configured to be inserted into a blood vessel after the guidewire 10 has been inserted at a desired location.

[0080] Another embodiment is a microcatheter and guidewire assembly 90 ( Figure 4 ). Regarding microcatheters, for example, Figure 3and Figure 4 As shown in FIG. , a microcatheter 50 may include a tube 52 having an axially collapsible braided distal portion 54 .

[0081] The guidewire of assembly 90 can be any embodiment of guidewire 10, or it can be a completely different guidewire, or it can be a guidewire that includes a mechanism for triggering axial collapse of the braid of a braided microcatheter. Similarly, if the guidewire is an embodiment of guidewire 10, assembly 90 can include guidewire 10 in combination with any microcatheter (even a non-braided microcatheter).

[0082] The guidewire of assembly 90 may be located inside the microcatheter (after the microcatheter is inserted into a blood vessel). The guidewire may include a wire, such as a substantially straight wire, having a mechanism at its distal end configured to actuate axial collapse of the braided distal portion 54 of the microcatheter 50 .

[0083] In some embodiments, the outer diameter of the microcatheter (before any axial collapse) is between about 0.9 mm and about 1.2 mm, or 2 to 3 French sizes. In one non-limiting embodiment, the outer diameter of the braided portion 54 varies from a minimum outer diameter of about 2.0 mm to a maximum outer diameter of about 5.0 mm after axial collapse. However, in other embodiments, the outer diameter can be greater or less than these numbers, as the desired outer diameter depends on the size and location of the blood clot to be reached (and removed, such as by capturing it) and other factors.

[0084] like Figure 4 As shown in , in the case where the microcatheter is a braided microcatheter 50, the braided distal portion 54 of the microcatheter 50 in the neutral or deployed position has a first outer diameter, a maximum first outer diameter, or an average first outer diameter. In the collapsed position, as shown in FIG. Figure 5 As shown in , after axial pressure has been applied by mechanism 56 (e.g., mechanism 56 on guidewire 10), the braided distal portion 54 of the microcatheter 50 has a second outer diameter such that the second outer diameter is greater than the first outer diameter (or such that the maximum second outer diameter or the average second outer diameter is greater than the maximum first outer diameter or the average first outer diameter).

[0085] exist Figure 4 , the outer diameter of the braided segment (e.g., the outer diameter of the gathered widest portion) can vary within a particular braided segment shown in FIG. 5 (e.g., braided segments 54a, 54c of braided portion 54) (or within the entire distal braided portion 54). Thus, for example, the braided distal portion can have a maximum first outer diameter X in the deployed position, and can have a maximum second outer diameter Y in the gathered position, such that the maximum second outer diameter Y is greater than the maximum first outer diameter X. For example, the maximum second outer diameter can be at least two times (or another multiple of) the maximum first outer diameter.

[0086] In another example, the braided distal portion 54 has an average first outer diameter in the expanded state (position) and a maximum second outer diameter in the collapsed state (position), such that the maximum second outer diameter is at least twice the average first outer diameter.

[0087] The word "twice" is just an example. The increase in the outer diameter or the maximum outer diameter may be other multiples, such as about 1.3, 1.5, 1.7, 1.7, 2.1, 2.3, 2.5, 2.7, 2.9, about 3.0 or any multiple in between.

[0088] In one embodiment, the mechanism for actuating axial retraction includes a mechanical actuator on the guidewire, which can be a guidewire 10 having a feature for rotating the distal tip or another guidewire without such a feature. A non-limiting example of such a mechanical actuator (which can be located on the guidewire 10 or another guidewire) is a protrusion 56 or a projection 56 or a flange 56, so that pulling the guidewire proximally causes axial pressure against the distal end 55 of the braided portion 54 or against the distal end of the microcatheter 50 or against another portion distal to the braided portion 54 (so that this indirectly places pressure on the braided portion). For example, the flange 56, protrusion 56 or annular projection 56 on the guidewire 10 can press against the distal end 55 of the braided distal portion 54 of the microcatheter or the distal end of the microcatheter 50 or against a portion distal to the braided portion 54.

[0089] Another value of the axially gathered strands forming braided portion 54 is that the strands of the braid, when they are gathered and have an increased outer diameter, will act as an embolic protection system that prevents emboli, such as blood clots or air bubbles, from traveling to the brain during a procedure.

[0090] In an assembly 90 including a braided microcatheter 50, the braided distal portion 54 can include a mixture of thicker strands and thinner strands, such as a symmetrical mixture of thicker strands and thinner strands. The strands themselves can be made of Nitinol, a metal alloy of nickel and titanium. In one non-limiting embodiment, the thicker strands are about 100 microns and the thinner strands are about 50 microns. In another non-limiting embodiment, the outer diameters of the strands can be completely different.

[0091] The Shore hardness and / or Young's modulus of the microcatheter can vary. In addition, the Shore hardness and / or Young's modulus of the braided distal portion 54 can also vary. The length of the braided distal portion 54 can also vary. In a non-limiting embodiment, the length of the braided distal portion 54 is about 10-25 mm or any length therebetween (depending on, for example, the expected size and position of the blood clot, and other factors). In another embodiment, its length is about 15 to 20 mm. In a non-limiting embodiment, the length of the braided portion 54 is between 16 mm and 19 mm or between 17 mm and 18 mm.

[0092] In some embodiments, the strands include radiopaque strands. For example, the strands may be made of a platinum-iridium alloy, which allows the distal tip 20 to be clearly seen in x-ray and other imaging techniques. Alternatively or in addition, there may be one or more radiopaque markers 59 on the strands, such as Figure 5 as shown in .

[0093] In one example, as in Figure 4 As can be seen in the figure, the braided distal portion includes, for example, a first braided portion 54a and a second braided portion 54c separated by a non-braided portion 54b. In another example, there may also be three braided portions or segments separated from each other by two non-braided segments, so as to present five alternating braided and non-braided segments (not shown). Other embodiments may include more than five braided and non-braided segments, such as alternating braided and non-braided segments. In addition, the lengths or relative lengths of the braided and non-braided segments are not necessarily as Figure 4 In addition, in some embodiments, one braided segment (eg, braided segment 54a) may have a larger or smaller outer diameter or a maximum outer diameter or an average outer diameter than another braided segment (eg, braided segment 54c).

[0094] Optionally, in order to induce controlled buckling or axial gathering of a braided segment (e.g., of braided segments 54a, 54c) at a specific point, specific joints of the braided segments or braided portions may be weaker, such as a joint between a braided portion and a non-braided portion. This is not a requirement.

[0095] As noted, the assembly 90 (of a guidewire and microcatheter) may include a guidewire 10. For example, the guidewire 10 may include a wire, such as a substantially straight wire 10a having a curved distal tip 20 (in any of the styles described herein). The guidewire 10 may also include a shaft 30 covering at least a portion of the wire and a coil 40 attached to cover a portion of the guidewire proximal to the distal tip 20 and distal to the shaft 30. In addition, linearly moving the shaft 30 toward the coil 40 may compress the coil 40 and rotate the distal tip 30. In some embodiments, the distal tip 20 may be rotated in the opposite direction, for example, by moving the shaft linearly backward or, for example, simply releasing the shaft 30 by loosening the shaft.

[0096] The braided portion 54 of the microcatheter 50, such as the braided distal portion 54, is configured to capture a blood clot beside the braided portion 54, such as the braided distal portion 54, when the microcatheter 50 is in a blood vessel. Thus, when the braided distal portion 54 is axially collapsed and the segments 54a, 54c are expanded outwardly / radially, they create potential snagging points or snagging areas for any blood clot located beside the microcatheter 50 in the blood vessel.

[0097] After the blood clot is captured by the strands of the braided portion of the microcatheter 50, when the microcatheter 50 is withdrawn from the blood vessel, the blood clot is also automatically removed with the microcatheter.

[0098] In the case of an aneurysm, the primary value is the guidewire and its ability to navigate the difficult-to-reach blood vessels where the aneurysm is located. Once the aneurysm is reached using the guidewire 10, treatment of the aneurysm begins. Treatment can be implemented in one of several ways, such as by endovascular coil embolization, stent grafts, or biografts.

[0099] Another option for the microcatheter 50 portion of the assembly 90 or a separate microcatheter 50 is optical fiber. The guidewire 10 can be removed and the optical fiber wire can be inserted at the desired location, such as a blood clot. Then, based on the algorithm, the clot composition and texture can be identified. For example, it can be determined whether the blood clot contains calcium or other specific compounds.

[0100] Another embodiment is a microcatheter 50 (not combined with a guidewire) comprising a tube having a braided portion 54, such as an axially collapsible distal braided portion 54. The microcatheter 50 may include any of the types described herein with respect to the assembly 90. For example, the braided distal portion 54 may include a (symmetrical) mixture of thicker strands and thinner strands. For example, the braided distal portion 54 may include a first braided portion and a second braided portion separated by a non-braided portion (or more than two braided portions separated (or not separated) by a non-braided portion). The braided distal portion 54 is configured to capture a blood clot next to the braided distal portion when the microcatheter is in a blood vessel.

[0101] The braided distal portion has a first outer diameter in the expanded state (position) and a second outer diameter in the retracted state (position), so that the second outer diameter is greater than the first outer diameter. The braided distal portion 54 has a maximum first outer diameter in the expanded state (position) and a maximum second outer diameter in the retracted state (position), so that the maximum second outer diameter is greater than the maximum first outer diameter. The maximum second outer diameter can be at least twice the maximum first outer diameter, or any other multiple, such as about 1.3, 1.5, 1.7, 1.9, 2.1, 2.3, 2.5, 2.7, 2.9, about 3.1, etc., or any value in between. The braided distal portion 54 has an average first outer diameter in the expanded state (position) and a maximum second outer diameter in the retracted state (position), so that the maximum second outer diameter is at least twice the average first outer diameter. The braided distal portion 54 can include or consist of a metal alloy of nickel and titanium.

[0102] As in Fig.10 As seen in the flowchart of , another embodiment is a method 100 for inserting a guidewire into a blood vessel containing a difficult-to-navigate portion. The method 100 may include step 110 of inserting a guidewire into a blood vessel, wherein the guidewire includes a wire (e.g., a substantially straight wire) having a curved distal end, a shaft covering a portion of the wire, and a coil attached to cover a portion of the wire proximal to the distal end and distal to the shaft.

[0103] Method 100 may also include step 120 of navigating a bend, loop, or bifurcation of a blood vessel by linearly moving the shaft toward the coil to compress the coil, the compression causing the distal tip to rotate (so as to more easily navigate the bend, loop, or bifurcation of the blood vessel) to reach one of a blood clot, an aneurysm, and a hemorrhagic stroke.

[0104] The method 100 may also include implementing treatment for at least one of a blood clot, an aneurysm (whether ruptured or unruptured), or a hemorrhagic stroke. For example, in the case of a blood clot, the treatment may involve inserting a microcatheter having an axially collapsed portion into the area of ​​the blood clot, then expanding the diameter of the axially collapsed portion (such as a braided portion) to capture the blood clot, and then removing the microcatheter along with the blood clot.

[0105] In the case of an aneurysm, treatment may involve inserting a microcatheter and treating the aneurysm using one of (i) endovascular coil embolization, (ii) stent graft, and (iii) a biograft. In some cases, this may involve inserting a microcatheter into the aneurysm region and pushing a coil through the microcatheter, for example to perform an endovascular coil embolization. Treatment may alternatively involve inserting a microcatheter into the aneurysm region and introducing a stent graft or a biograft to treat the aneurysm. The microcatheter may be any of the microcatheters described herein, including any type of microcatheter 50 or another microcatheter.

[0106] As in Fig.11 As can be seen in the flowchart of , another method can be a method 200 of removing a blood clot from a blood vessel of a mammalian subject. Method 200 can include step 210: inserting a microcatheter over a guide wire into a blood vessel. The microcatheter can have an axially collapsible braided distal portion. The microcatheter can be extended over the guide wire so that the distal end of the guide wire extends further than the distal end of the microcatheter. In some versions, there is a previous step of inserting the guide wire.

[0107] The method 200 may include step 220 of pulling the guidewire proximally so that the mechanism 56 on the guidewire triggers axial collapse of the braided distal portion of the microcatheter 50 .

[0108] The method 200 may also include axially gathering the braided distal portion to capture a blood clot outside the microcatheter. The method 200 may also include the step of withdrawing the catheter with the blood clot.

[0109] In some embodiments of method 200, the mechanism includes a flange, protrusion, or annular protrusion that presses against the distal end of the braided distal portion (or against a portion distal to the braided distal portion) as the guidewire moves proximally.

[0110] In some embodiments of method 200, the guidewire is guidewire 10, such that in one example, the guidewire 10 includes a wire (e.g., a substantially straight wire) having a curved distal tip, a shaft covering a portion of the wire, and a coil attached to cover a portion of the wire proximal to the distal tip and distal to the shaft, such that linear movement of the shaft causes the coil to undergo compression and rotate the distal tip.

[0111] like Fig.12 As shown in the flowchart of , the general method 300 includes a first step 310 of inserting a microcatheter into a blood vessel, the microcatheter having an axially collapsible braided portion. The method 300 also includes the step of actuating a mechanism for triggering the axial collapsing of the braided portion of the microcatheter to capture a blood clot in the strands of the braided portion. Further steps may include removing the microcatheter and the blood clot adhered to the braided portion of the microcatheter.

[0112] In any of the methods 100, 200, 300, the microcatheter used may be any type of microcatheter described herein, including any type of microcatheter 50 with or without any type of guidewire 10 or another guidewire.

[0113] like Fig.13 , another embodiment is a system 94 including a robot 95 and an assembly 90 of a microcatheter and a guidewire. The robot 95 may, for example, include at least one motor. For example, it may include a first motor 96 that moves a guidewire (such as guidewire 10) and a second motor 97 that moves a microcatheter (such as microcatheter 50). In one embodiment, an actuator 98 controlled by an input device 99 such as a joystick 99 actuates these movements. In the system 94, the microcatheter used may be any type of microcatheter described herein, including any type of microcatheter 50 with or without any type of guidewire 10 or another guidewire.

[0114] Although the present invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the present invention are possible.Accordingly, the claimed invention as recited in the appended claims is not limited to the embodiments described herein.

Claims

1. A medical guidewire for improving vascular navigation, comprising: a wire having a curved distal tip; a shaft covering at least a portion of the wire; a coil attachedly covering a portion of the wire proximal to the distal tip and distal to the shaft, Wherein, linearly moving the shaft toward the coil causes the coil to experience compression and rotate the distal tip.

2. The guide wire according to claim 1, wherein: Moving the shaft linearly away from the coil releases the coil and rotates the distal tip in the opposite direction.

3. The guidewire according to claim 1, wherein: The compression experienced by the coil causes the distal tip to rotate up to 720 degrees.

4. The guidewire according to claim 1, wherein: The compression experienced by the coil causes the distal tip to rotate through a range of 90 to 720 degrees.

5. The guide wire according to claim 1, wherein: The distal tip is radiopaque.

6. The guidewire according to claim 1, wherein: The radius of the distal tip is approximately 3 mm.

7. The guidewire of claim 1 further comprising a tube within the shaft.

8. The guidewire according to claim 1, wherein: The coil is made of a metal alloy of nickel and titanium.

9. The guidewire according to claim 1, in combination with a microcatheter.

10. The guide wire according to claim 1, wherein: Aside from the curved distal tip, the wire is substantially straight.

11. An assembly of a microcatheter and a guidewire, comprising: The microcatheter comprises a tube having an axially collapsible braided distal portion; The guidewire is within the microcatheter and includes a mechanism at a distal end configured to actuate axial collapse of a braided distal portion of the microcatheter.

12. The assembly according to claim 11, wherein The braided distal portion has a first outer diameter in an expanded position and a second outer diameter in a collapsed position such that the second outer diameter is greater than the first outer diameter.

13. The assembly of claim 11, wherein: The braided distal portion has a first maximum outer diameter in an expanded position and a second maximum outer diameter in a collapsed position, such that the second maximum outer diameter is greater than the first maximum outer diameter.

14. The assembly of claim 13, wherein: The maximum second outer diameter is at least twice the maximum first outer diameter.

15. The assembly of claim 11, wherein: The braided distal portion has an average first outer diameter in an expanded position and a maximum second outer diameter in a collapsed position, such that the maximum second outer diameter is at least twice the average first outer diameter.

16. The assembly of claim 11, wherein: The mechanism includes a flange, protrusion or annular projection such that pulling the guidewire proximally causes the flange, protrusion or annular projection to press against (i) a distal end of the braided distal portion or (ii) a distal end of a portion distal to the braided distal portion.

17. The assembly of claim 11, wherein: The braided distal portion includes a mixture of thicker strands and thinner strands.

18. The assembly of claim 11, wherein: The braided distal portion includes a symmetrical mixture of thicker strands and thinner strands.

19. The assembly of claim 11, wherein: The braided distal portion includes a first braided portion and a second braided portion separated by a non-braided portion.

20. The assembly of claim 11, wherein: The guidewire has a curved distal tip, the guidewire further comprising a shaft covering at least a portion of the guidewire and a coil attached to cover a portion of the guidewire proximal to the distal tip and distal to the shaft, wherein linearly moving the shaft toward the coil causes the coil to experience compression and causes the distal tip to rotate.

21. The assembly of claim 11, wherein: The braided distal portion includes a metal alloy of nickel and titanium.

22. The assembly of claim 11, wherein: The braided distal portion is configured to capture a blood clot beside the braided distal portion when the microcatheter is in a blood vessel.

23. The assembly of claim 11, wherein: The guidewire is substantially straight except at the curved distal tip of the guidewire.

24. A microcatheter comprising a tube having an axially collapsible braided distal portion.

25. The microcatheter of claim 24, wherein: The braided distal portion includes a mixture of thicker strands and thinner strands.

26. The microcatheter of claim 24, wherein: The braided distal portion includes a first braided portion and a second braided portion separated by a non-braided portion.

27. The microcatheter of claim 24, wherein: The braided distal portion is configured to capture a blood clot beside the braided distal portion when the microcatheter is in a blood vessel.

28. The microcatheter of claim 24, wherein: The braided distal portion has a first outer diameter in an expanded position and a second outer diameter in a collapsed position such that the second outer diameter is greater than the first outer diameter.

29. The microcatheter of claim 24, wherein: The braided distal portion has a first maximum outer diameter in an expanded position and a second maximum outer diameter in a collapsed position, such that the second maximum outer diameter is greater than the first maximum outer diameter.

30. The microcatheter of claim 29, wherein: The maximum second outer diameter is at least twice the maximum first outer diameter.

31. The microcatheter of claim 24, wherein: The braided distal portion has an average first outer diameter in an expanded position and a maximum second outer diameter in a collapsed position, such that the maximum second outer diameter is at least twice the average first outer diameter.

32. The microcatheter of claim 24, wherein the braided distal portion comprises a metal alloy of nickel and titanium.

33. A method of inserting a guidewire into a blood vessel containing a difficult-to-navigate portion, the method comprising: inserting the guidewire into the blood vessel, wherein the guidewire comprises a guidewire having a curved distal tip and comprises a shaft covering a portion of the guidewire and a coil attachedly covering a portion of the guidewire proximal to the distal tip and distal to the shaft; A curved, looped or bifurcated portion of the blood vessel is navigated by linearly moving the shaft toward the coil to compress the coil, the compression causing the distal tip to rotate to reach one of a blood clot, an aneurysm and a hemorrhagic stroke.

34. A method of removing a blood clot from a blood vessel of a mammalian subject, comprising: inserting a microcatheter over a guidewire into a blood vessel, the microcatheter having an axially collapsible braided distal portion such that a distal end of the guidewire extends further than a distal end of the microcatheter; and The guidewire is pulled proximally so that a mechanism on the guidewire triggers axial contraction of the braided distal portion.

35. The method of claim 34, further comprising axially contracting the braided distal portion to capture a blood clot outside of the microcatheter.

36. The method of claim 35, further comprising withdrawing the catheter with the blood clot.

37. The method of claim 34, wherein: The mechanism includes a flange, a protrusion or annular projection that presses against a distal end of: (i) the braided distal portion or (ii) a portion distal to the braided distal portion.

38. The method of claim 34, wherein: The guidewire includes a wire having a curved distal tip, a shaft covering a portion of the wire, and a coil attached to cover a portion of the wire proximal to the distal tip and distal to the shaft, such that linear movement of the shaft compresses the coil and rotates the distal tip.

39. A method for treating an aneurysm, comprising: inserting the guidewire into the blood vessel, the guidewire comprising a wire having a curved distal tip and comprising a shaft covering a portion of the guidewire and a coil attachedly covering a portion of the guidewire proximal to the distal tip and distal to the shaft; navigating a curved, looped, or bifurcated portion of the vessel to reach the aneurysm by linearly moving the shaft toward the coil to compress the coil, the compression rotating the distal tip; as well as A microcatheter was inserted and the aneurysm was treated using one of (i) endovascular coil embolization, (ii) stent graft, and (iii) biologic graft.

40. A system for navigating a difficult-to-navigate blood vessel, comprising: robot, The robot comprises at least one motor and an actuator; Input device; An assembly of a microcatheter and guidewire, comprising: The microcatheter comprises a tube having an axially collapsible braided distal portion; The guidewire is within the microcatheter and includes a wire having a mechanism at a distal end configured to actuate axial collapse of a braided distal portion of the microcatheter.

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