Endovascular treatment site access

Abstract

To provide a micro catheter designed so as to minimize an open space between the micro catheter and a guide catheter on an outer peripheral surface side.SOLUTION: A micro catheter 10 to be used to navigate via a vascular bifurcation region includes: a first section; a second section 14 distal of the first section, where an outer diameter of the second section 14 is larger than an outer diameter of the first section; and a distal tip distal of the second section 14, an outer diameter of a distal tip of which is smaller than the outer diameter of the second section 14. The second section 14 forms an interface for minimizing an open space between the micro catheter 10 and a guide catheter 38 on an outer peripheral surface side.SELECTED DRAWING: Figure 3

Description

Related Applications

[0001] This application claims priority to U.S. Provisional Application No. 62 / 293,522, filed February 10, 2016, entitled "Intravascular Treatment Site Access," which is hereby incorporated by reference in its entirety. Background of the Invention

[0002] Guidewires are typically used in minimally invasive interventional procedures to access treatment areas. Guide catheters typically slide along the outer peripheral surface of a guidewire to access a target area and then function as conduits for microcatheters and / or treatment / devices to be subsequently deployed.

[0003] The vasculature can be, among other things, coiled or tortuous. This is especially true in the neurovasculature where there are many small, tortuous blood vessels that make it very difficult to access the target area and deliver treatment devices. In a phenomenon known as the ledge effect, there is a gap between the distal end of a guidewire and a guide catheter that can be trapped along a blood vessel bifurcation, preventing the catheter from effectively moving through the vasculature. The ophthalmic artery is an example of an area with a bifurcation and significant vessel tortuosity and is an example of an area where a catheter can become clogged.

[0004] A system that minimizes or eliminates the gap between a guidewire and a guide catheter is desirable to prevent the catheter from becoming stuck within the vasculature. SUMMARY OF THE INVENTION

[0005] In one embodiment, a microcatheter having an enlarged distal section is described. The enlarged portion of the microcatheter is disposed proximate to the inner diameter of the guide catheter to reduce any open space between the microcatheter and the guide catheter, and a guide wire can be disposed through the microcatheter and used to guide the system. The microcatheter can include one or more marker bands to assist in accurately aligning the microcatheter with respect to the guide catheter. After moving the guide catheter and the microcatheter to an appropriate treatment site, the microcatheter can be used to deploy various medical devices for treating a patient.

[0006] In one embodiment, a microcatheter having an enlarged distal section includes a plurality of marker bands to assist visualization. The marker bands can be used to properly align the microcatheter with respect to the guide catheter such that the enlarged distal section of the microcatheter coincides with the distal tip of the guide catheter. A guide wire is used to access the treatment site, and the microcatheter and the guide catheter can be moved on the outer peripheral surface side of the guide wire.

[0007] In one embodiment, an obstacle removal system is described. The obstacle removal system includes a guide catheter, a microcatheter having an enlarged distal section supplied through the guide catheter, and an obstacle removal device supplied through the microcatheter. A guide wire is moved through the microcatheter, and the guide wire is used to assist in moving the microcatheter and guide the catheter near the treatment site. Once the treatment site is accessed, the microcatheter can be used to supply an obstacle removal device such as a thrombus retrieval device (such as a stentriever) to remove an obstacle (such as a blood clot).

[0008] In one embodiment, a guide wire is described. The guide wire includes a protrusion for minimizing or eliminating the gap between the guide wire and the guide catheter. In one embodiment, the protrusion is bulbous. The protrusion can further include a radiopaque marker that aids in imaging and placement of the guide wire.

[0009] In one embodiment, the guide wire includes a shapeable or malleable distal tip and a torque device. The shapeable or malleable distal tip can be bent in a particular direction, and the torque device clamps and secures the guide wire. The guide wire can then be rotated in a particular direction so that the distal tip aligns with a particular blood vessel to assist in moving the guide wire through the vasculature.

[0010] In one embodiment, a method of using a guide wire is described. The guide wire includes a distal protrusion and a radiopaque marker. The guide catheter also includes a radiopaque marker. The guide wire is retracted or the guide catheter is advanced so that the protrusion of the guide wire contacts the guide catheter. The guide wire and the guide catheter can then be advanced together by pushing the guide catheter. The radiopaque markers of the guide catheter and the guide wire are either located in the same plane or adjacent to each other and are distinguishable to the user due to enhanced radiopacity when viewed with a conventional imaging system. The user can lock and rotate the guide wire using a torquer, if necessary, so that the distal tip is oriented in a particular direction to assist in advancing the guide wire through the vasculature.

[0011] In one embodiment, a rapid exchange system is described. In a scenario where a catheter is trapped at a vascular bifurcation and the rapid exchange system moves along the outer peripheral surface side of the guide wire and includes a distal expansion section to bridge the gap between the guide wire and the guide catheter, the rapid exchange system minimizes the gap between the guide wire and the guide catheter.

Brief Description of the Drawings

[0012] These and other aspects, features, and advantages of embodiments of the present invention will become apparent and understood from the following description of embodiments of the present invention with reference to the accompanying drawings.

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[0021] Specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and will fully convey the scope of the invention to those skilled in the art. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the drawings, like numbers indicate like elements.

[0022] Many minimally invasive procedures access the area near the treatment site using a guide catheter, also known as a distal access catheter (DAC). A thin, flexible guide wire is advanced through the vasculature, and the guide catheter / DAC is advanced on the outer peripheral surface side of this guide wire to access the treatment site. Once the area is accessed, a microcatheter is deployed through the guide catheter and the guide wire is withdrawn. The microcatheter is then used to assist in and supply therapeutic or treatment agents such as stents, clot retrieval devices, or coils used to fill aneurysms. Guide catheters typically have a relatively large diameter since they must accommodate both the guide wire and the microcatheter. Movement of the guide catheter through the vasculature is difficult due to the complex nature of the anatomical structures. It is particularly difficult in the brain or neurovascular system where the blood vessels are small, intricate, and highly branched, making it difficult to move the catheter to the appropriate treatment site.

[0023] At vascular bifurcations, there is a navigational obstacle due to the gap between the distal end of the guide wire and the guide catheter, and the distal end of the guide catheter may become stuck at that bifurcation. This phenomenon is known as the ledge effect (see Figure 1), where the gap 6 between the guide wire 4 and the guide catheter 8 is trapped at the vascular bifurcation 5. In one example, the inner diameter of a typical guide catheter 8 is 0.07 inches, and the diameter of the guide wire 4 is between 0.014 inches and 0.035 inches. The gap size 6, defined as the radius of the guide catheter 8 minus the radius of the guide wire 4, is typically between 0.0175 inches and 0.028 inches. This gap size 4 corresponds to between 25 and 40% of the inner diameter of a typical guide catheter and represents a significant amount of open space. The problem of guide catheter movement can delay treatment or even make treatment impossible, increasing the risk to the patient. The following embodiments address this problem.

[0024] US Publication No. US2016 / 0022964, entitled "Systems and Methods for Intracranial Vascular Access" by Goyal, discloses a guidewire system that addresses the complex relationships of the ledge effect with a guidewire having an enlarged region designed to bridge the gap between a guide catheter on the outer peripheral surface side and a guidewire on the inner peripheral surface side. US Publication No. US2016 / 0022964 is hereby incorporated by reference in its entirety.

[0025] Figures 2 - 3 and the following disclosure relate to an intermediate microcatheter 10 having an enlarged region 14 that minimizes any gap between the guidewire 22 and an outer guide catheter 38 on the outer peripheral surface side. In other words, the intermediate microcatheter 10 slides on the outer peripheral surface side of the guidewire 22, and its enlarged distal end 14 occupies the open space within the lumen of the outer guide catheter 38. When the enlarged region 14 is positioned at or somewhat beyond the distal end of the outer guide catheter 38, the "ledge" created by the outer guide catheter 38 is reduced or eliminated, thereby avoiding entrapment in vascular bifurcations and other vascular geometries. Further, several embodiments described later in this specification (see Figures 4 - 9) disclose an improved guidewire system where the guidewire has an enlarged region that bridges the gap between the guide catheter on the outer peripheral surface side and the guidewire.

[0026] Figure 2 shows a microcatheter 10 having an expanded shape distal section or enlarged distal section 14. The expanded shape / enlarged distal section 14 can have a generally cylindrical shape with a tapered end, a longitudinally rounded shape, or any other common shape. Although the distal section 14 is enlarged, the inner diameter defining the lumen 12 in the microcatheter 10 is preferably constant over the entire length of the microcatheter 10. Preferably, the expanded shape or enlarged distal section 14 of the microcatheter 10 exactly matches or is slightly smaller than the inner diameter of the guide catheter 38 on the outer peripheral surface side. As seen in Figure 3, this close or near - close fit of the enlarged distal section 14 bridges or fills the gap between the intermediate microcatheter 10 and the guide catheter 38. This creates a conforming interface between the two catheters and prevents any open exposed surfaces that could otherwise be trapped in a blood vessel bifurcation. For example, the inner diameter of the outer guide catheter 38 is about 0.070 inches and the diameter of the enlarged distal section 14 is about 0.067 inches. This reduces the gap size 26 to about 0.0015 inches on all sides. This is in contrast to the gap size 6 between the guide wire 22 and the outer guide catheter 38, which is about 0.0175 - 0.028 inches on all sides (using a guide wire of 0.014 - 0.035 inches). The 0.0015 - inch gap size is only about 2% of the total inner diameter of the outer guide catheter 38. In other examples, the enlarged distal section 14 has a diameter that is approximately the same as the inner diameter of the guide catheter 38. In either of these two examples, the diameter of the enlarged distal section 14 is close to the inner diameter of the outer guide catheter 38, and the limited opening space does not provide sufficient space to be trapped by the blood vessel. The expansion / enlargement section 14 may have a linear taper 20 as shown in Figure 2, and the shape of the taper may be rounded or elliptical.To minimize the gap between the inner diameter of the microcatheter 10 and the guide wire 22, the distal tip 18 of the intermediate microcatheter 10 preferably maintains an inner diameter size that is substantially the same as (i.e., relatively close or proximate to) the proximal portion of the intermediate catheter 10.

[0027] In another embodiment, the inner diameter of the lumen of the microcatheter 10 is larger within the expansion region 14. However, in this embodiment, to prevent any openings that would capture the surface between the blood vessel and the microcatheter 10, the distal tip 18 of the microcatheter 10 has a relatively reduced inner diameter, and it is desirable to eliminate any large gaps between the guide wire 22 and the intermediate microcatheter 10.

[0028] The distal marker band 16a and the proximal marker band 16b are each disposed on the microcatheter body 11 at the distal and proximal ends of the expanded distal section 14 to assist in visualizing the position of the intermediate microcatheter 10 (particularly the distal section of the microcatheter 10). In one embodiment, a third marker band (not shown) can be disposed on the distal tip 18 of the intermediate microcatheter 10 beyond the expanded distal section 14 so that the distal tip 18 of the device can be visually recognized within the patient.

[0029] In an example of the bulbed intermediate microcatheter 10 of the present invention, the outer guide catheter 30 has an inner diameter of about 0.07 inches, the enlarged distal section 14 of the intermediate microcatheter 10 has an outer diameter of about 0.067 inches, the region of the microcatheter body 11 proximal to the enlarged section 14 has an outer diameter of about 0.033 inches, and the distal tip 18 has an outer diameter of about 0.031 inches. The smaller outer diameter of the distal tip 18 promotes improved flexibility and tracking, while the larger outer diameter of the proximal section of the microcatheter body 11 promotes increased pushing strength. The inner diameter of the intermediate microcatheter 10 is constant at about 0.021 inches. These dimensions can vary based on the guide wire or guide catheter used. For example, the outer diameter of the intermediate microcatheter 10 ranges from about 0.013 inches to about 0.073 inches, the length of the enlarged section 14 is from about 0.5 cm to about 3 cm, and the length of the distal tip 18 is from about 0.5 cm to about 6 cm. The inner diameter of the intermediate microcatheter 10 is constant from about 0.01 inches to about 0.045 inches over its entire length. The working length of the intermediate microcatheter 10 is about 148 - 168 cm. Optionally, a lubricity coating can be used on the outer peripheral surface side of the enlarged section 14 of the intermediate microcatheter 10.

[0030] The intermediate microcatheter 10 can be manufactured in a variety of ways. In one example, the inner liner of the intermediate microcatheter 10 is composed of PTFE, LDPE, LLDPE, or HDPE. The stainless steel coil is disposed on the outer peripheral surface side of the inner liner and is either a coiled wire or a flat wound wire having a diameter of from about 0.00075 inches to about 0.0015 inches. The stainless steel flat wire or blade is disposed on the outer peripheral surface side of the coil. An outer shaft layer can be disposed on the outer peripheral surface side of the reinforcement, and this outer layer can include different durometers and different types and amounts of materials, for example having a shore hardness in the range of 10A to 72D. Generally, it is desirable to have higher rigidity at the proximal end and higher flexibility at the distal end, and thus, the outer layer proximal section generally includes a more rigid material than the outer layer distal section. Together with additional marker bands disposed at the distal tip 18 of the intermediate microcatheter 10, one or two platinum / iridium (90% / 10%) marker bands are disposed on the inner peripheral surface side of the valve for visualization. The enlarged outer diameter region 14 including the valve is made of a relatively soft polymeric material such as polyblends 18A, 30A, balloons, or any shore hardness A durometer material. This softness aids in the advancement through the guide catheter 38 and flexibility in scenarios where the inner diameter of the outer guide catheter 38 closely matches the outer diameter of the bulbed section 14, or in scenarios where the bulbed section 14 contacts a portion of a blood vessel and the soft material helps prevent vascular trauma (e.g., at a blood vessel bifurcation).

[0031] The microcatheter 10 can enhance its followability by utilizing a lubricious coating along its entire length or selectively along specific portions. The lubricious coating is particularly useful in the expansion region 14 of the microcatheter 10. This is because the expansion region 14 is the maximum cross-sectional portion of the microcatheter 10 and is also the portion of the microcatheter that is most likely to come into contact with the guide catheter 38 on the outer peripheral surface side. In one example, the lubricious coating is hydrophilic and can utilize multiple layers (e.g., a well-adhering base coat layer formed from a cross-linking agent and a highly lubricious top coat layer chemically adhered to the base coat layer).

[0032] The guide catheter 38 typically utilizes a marker band 40 located approximately 3 cm from its distal tip, so that the user can visualize the distal tip within the patient (see FIG. 3). As shown in FIG. 3, the user moves the microcatheter 10 through the guide catheter 38 such that the expansion / enlargement region 14 of the intermediate catheter 10 is disposed in the same plane as the distal tip of the outer guide catheter 38. This ensures that there is no gap between the guide catheter 38 and the microcatheter 10, or that the gap therebetween is minimized. This minimized gap is shown as element 26, while the proximal gap 36 reflects the gap between the guide catheter 38 and the reduced proximal portion of the microcatheter 10. The proximal gap 36 can be considered the normal gap between the microcatheter and the guide catheter in a scenario where a typical microcatheter rather than an expanded microcatheter is used. As described above, the gap 6 represents the typical gap that exists between the guide wire 22 and the guide catheter 38 in a typical procedure of directly moving the guide catheter on the outer peripheral surface side of the guide wire.

[0033] The expandable intermediate microcatheter 10 acts as an intermediary between the guidewire 22 and the guide catheter 38, as described above. When the intermediate microcatheter 10 is properly positioned as shown in FIG. 3, the user will view the lines of the microcatheter distal marker band 16a, the outer guide catheter 3 cm marker band 40, and the proximal marker band 16b. Each of these marker bands can be either a series of discrete segments (one for each marker band) with gaps therebetween, or an elongated and continuous segment. The lines of these marker bands ensure accurate alignment, so that the user can know that the expanded distal section of the microcatheter 10 has passed beyond the distal tip of the guide catheter 38 such that the expanded section 14 of the microcatheter 10 occupies the space within the guide catheter 38. Once the user confirms this, the user can proceed with the movement of the guidewire, the intermediate microcatheter on the outer peripheral surface side of the guidewire, and the guide catheter on the outer peripheral surface side of the intermediate microcatheter.

[0034] The intermediate microcatheter 10 is used as a bridging device between the guide wire 22 and the guide catheter 38, so there will also be a small gap 30 between the guide wire 22 and the microcatheter 10. This gap 30 desirably is not completely eliminated to avoid friction between the guide wire 22 and the intermediate microcatheter 10. However, this gap 30 is relatively small and thus will not be trapped by a blood vessel bifurcation. In one example, the microcatheter 10 has a constant inner diameter of about 0.021 inches and accommodates a guide wire 22 sized from 0.014 inches to 0.018 inches. Applying the aforementioned formula for defining the gap size, subtracting the radius of the inner element (here the guide wire 22) from the radius of the outer element (here the microcatheter 10), the gap size between the microcatheter and the guide wire is from about 0.00205 inches to about 0.0035 inches. If, hypothetically, the microcatheter were not used at all as described above, the gap size could be in the range of about 0.0175 inches to 0.028 inches. In other words, the gap size is reduced to about 7 - 20% of its initial value simply by using the microcatheter. By using the expandable shape microcatheter as described above, the gap between the microcatheter and the guide catheter on the outer peripheral surface side is further reduced. Therefore, there are two advantages to using the expandable microcatheter 10 as an intermediate element between the guide wire 22 and the guide catheter 38. That is, first, to minimize the gap that normally exists between the guide wire and the guide catheter. Second, the presence of the expansion / enlargement section 14 of the microcatheter 10 minimizes the gap between the microcatheter 10 and the guide catheter 38. Reducing or minimizing the gap minimizes the amount of open space that can be trapped by a blood vessel bifurcation and thus substantially enhances the tracking ability of the device through complex anatomical structures.

[0035] Alternative embodiments can utilize an expandable intermediate microcatheter 10 having more or fewer marker bands. In one example, the expandable intermediate microcatheter 10 can use three marker bands where a third intermediate marker band is positioned between the distal marker band 16a and the proximal marker band 16b. This intermediate marker band is aligned with the guide catheter 3 cm distal tip marker 40. Such embodiments would be most useful for larger microcatheters having an elongated expansion region 14 as it can be difficult to view a very large number of marker bands individually. In another example, the intermediate microcatheter 10 can use one marker band where the microcatheter marker band is aligned with the guide catheter distal tip marker band 40 to ensure proper positioning of the intermediate microcatheter.

[0036] In one method of use, the guide wire 22 is moved through the patient's blood vessel and the guide catheter 38 is moved on the outer circumferential surface side of the guide wire 22. When the guide wire 22 advances through a blood vessel bifurcation region, the user moves the expandable intermediate microcatheter 10 on the outer circumferential surface side of the guide wire 22. This movement is performed such that the microcatheter 10 is disposed in the distal region of the guide catheter 38 and extends from the distal tip of the guide catheter 38. At this time, the distal tip 18 of the intermediate microcatheter 10 is disposed distally of the outer guide catheter 38, and the expansion region 14 of the intermediate microcatheter 10 bridges the gap between the guide wire 22 and the guide catheter 38. To achieve the desired position, the intermediate microcatheter 10 has two marker bands 16a and 16b as shown in FIGS. 2-3. The user operates the intermediate microcatheter 10 such that the two marker bands 16a and 16b are respectively disposed on both sides of the guide catheter 3 cm distal tip marker band 40. The user moves the intermediate microcatheter 10 and the guide catheter 38 together as a unit and simultaneously pushes both of them to move on the outer circumferential surface side of the guide wire 22 through the bifurcation region.

[0037] In another embodiment, the expandable intermediate microcatheter 10 is used as part of an implant delivery system. The expandable microcatheter 10 addresses the issue of the ledge effect and is also used as a conduit for delivering implants such as stents, blood clot retrieval devices, or embolization coils. After advancing the intermediate microcatheter 10 to the treatment site using the guidewire 22, the guidewire 22 is withdrawn through the intermediate microcatheter 10. Thereafter, an implant is delivered using the intermediate microcatheter 10.

[0038] In one embodiment, the expandable intermediate microcatheter 10 is part of a blood clot retrieval system. Blood clots can cause problems such as ischemic stroke due to reduced blood flow to the distal regions of the blood clot. A blood clot retrieval device is a mechanical structure designed to grasp, hold, and remove blood clots from the vasculature. U.S. Patent No. 9,211,132, entitled "Debris Removal System," discloses a blood clot retrieval device, which is hereby incorporated by reference in its entirety. A stent retriever is a type of blood clot retrieval device that takes the form of a single tubular wire mesh or a cylindrical laser cut sheet element designed to hold blood clots. U.S. Patent Nos. 8,679,142, 8,357,179, and 6,402,771 further disclose stent retriever devices, which are hereby incorporated by reference in their entirety.

[0039] In one embodiment, the expandable intermediate microcatheter 10 is part of a blood clot retrieval system. In another embodiment, the expandable microcatheter 10 is used as part of a stent retriever system. The expandable intermediate microcatheter 10 addresses the issue of the ledge effect. Here, the system assists the blood clot retriever in accessing the problematic area (e.g., a branching area within the neurovascular system). The system includes a guide catheter 38, an intermediate microcatheter 10, a guide wire 22, and a blood clot retriever or stent retriever (not shown). The guide catheter 38 is structurally more rigid than the microcatheter 10 and moves through most of the vascular system to the general area of the delivery procedure. The intermediate microcatheter 10 is smaller than the guide catheter 38, is delivered through the guide catheter, accesses the actual treatment site, thereby providing a conduit to the treatment site. The guide wire 22 helps move the microcatheter 10 and the guide catheter 38 through the vascular system to access the treatment site. The delivery procedure is similar to the above, where the microcatheter can be moved on the outer peripheral surface side of the guide wire and positioned beyond the distal tip of the guide catheter to move the system through the vascular branching area. When the system is properly positioned, the guide wire 22 is withdrawn through the expandable intermediate microcatheter 10, and the microcatheter 10 is used as a conduit for the blood clot retriever or stent retriever.

[0040] In one embodiment, the thrombus retrieval device or stent retriever is pre-supplied via the expandable intermediate microcatheter 10 to the distal section of the intermediate microcatheter 10. At this time, the distal end of the thrombus retrieval device or stent retriever is arranged in the same plane as the distal end of the intermediate microcatheter 10 or beyond the distal end of the intermediate microcatheter 10. The intermediate microcatheter 10 is accommodated in the guide catheter 38 as shown in FIG. 3. The outward force provided by the thrombus retrieval device can be used to assist the catheter and stent retriever to advance through the vascular bifurcation region and complex anatomical structures. That is, the force applied to the microcatheter by the thrombus retrieval device helps to direct the system in a specific direction at the vascular bifurcation and can also assist in the orientation of the system through complex anatomical structures.

[0041] In some embodiments, the expandable intermediate microcatheter 10 is used for the movement of the guide catheter 38 without the guide wire 22 and is then used for the supply device of the subsequently supplied treatment material. The distal section 14 of the expandable intermediate microcatheter 10 is preferably coated with a lubricious coating, which reduces friction through the guide catheter 38 and promotes smooth movement through the vasculature. Further, the distal inner diameter of the expandable intermediate microcatheter 10 is considerably smaller than the inner diameter of the outer guide catheter 38, so there are fewer open lumen surfaces that can be trapped in the vascular bifurcation.

[0042] In some embodiments, after the guide wire 22 is first deployed, the expandable microcatheter 10 is moved on the outer peripheral surface side of the guide wire 22, while the guide catheter 38 is separately moved on the outer peripheral surface side of the expandable microcatheter 10. In some embodiments, the guide wire 22 is first deployed, while the expandable microcatheter 19 and the guide catheter 38 are deployed simultaneously and together on the outer peripheral surface side of the guide wire.

[0043] Another possible embodiment used to address the problem of the ledge effect utilizes a guidewire having an enlarged area that bridges the gap between the guidewire and the guide catheter. For example, the guidewire 110 shown in FIG. 4 has a radial projection 116 at its distal end that radially bridges the gap within the guide catheter 38. In this regard, the intermediate microcatheter having an enlarged distal end described in the previous embodiment is not necessary.

[0044] The radial projection 116 is disposed within the distal section 110b of the guidewire 110 and can have a number of shapes including an ellipsoid, oval, circular, expanded shape, or diamond shape. The projection 116 is, in one particular example, an expanded shape. The projection 116 preferably consists of a soft polymer material and facilitates movement through the patient's blood vessel. The soft polymer is less rigid and more malleable than a hard polymer, and when the radial projection 116 contacts the blood vessel wall, it is less likely to bounce or move suddenly. To prevent any large unexpected movement, it is also preferred that the projection 116 slides rather than bounces against the blood vessel wall. The smooth transition formed by the taper 116a at the projection 116 further prevents the guidewire 110 from bouncing after contacting the blood vessel wall within the vascular system.

[0045] The projection 116 further includes a radiopaque marker 118, which in one example is a circular marker band disposed around the polymeric radial projection 116. The marker band can include platinum, tantalum, palladium, gold, or any similar high-density metallic element, alloy, or compound that is visualized by imaging techniques.

[0046] The distal section 110b of the guidewire 110 also includes a tapered section 132, a reduced-diameter section 134, and a coil 117 disposed on the outer peripheral surface side of the reduced-diameter section 134. The coil 117 is composed of two different coil elements, namely, a first non-radiopaque coil portion 114 (made of stainless steel in one example) and a second radiopaque coil portion 122 (made of platinum in one example) that is useful for imaging the distal section of the catheter. The coil 117 provides a soft contact surface and aids in flexibility to avoid vascular trauma when the guidewire tip hits the vessel wall.

[0047] The guidewire 110 also includes a distal tip 120 shaped to assist in advancing the guidewire through the vasculature. A shaping mandrel can be used to help shape the distal tip 120 of the guidewire (so that the distal tip bends in a specific direction). Guidewire shaping mandrels are currently used to pre-shape the distal tip of the guidewire. These shaping mandrels are typically packaged with the guidewire, and the user uses the mandrel to impart a bent shape to the distal tip of the guidewire before placing the guidewire into the patient's vasculature. The bent shape is useful for adapting the guidewire to progress through the vasculature. The user rotates the guidewire to align the tip, which is curved in the desired direction of guidewire advancement, for example, at a vascular bifurcation, to assist the advancement of the catheter and the guidewire moving on the outer peripheral surface side of the guidewire through complex anatomical structures.

[0048] The guide wire 110 is preferably tapered such that its proximal section 110a has a larger diameter than its distal section 110b. This tapered shape aids in torque response, and the torque generated by applying torque to the proximal end of the system is easily transmitted via the guide wire 110, resulting in sufficient torque response at the distal tip 120 of the guide wire 110. In one example, the guide wire 110 has a proximal diameter 112 of about 0.013 inches to about 0.014 inches, and in a more specific example, has a diameter of about 0.0135 inches. This diameter may be slightly tapered or may be substantially constant. The guide wire 110 has a distal section diameter 124 of about 0.012 inches. The distal section diameter 124 only targets the diameter of the distal coil 117 including the coil elements 114 and 122.

[0049] Figures 4 - 6 show an optional docking element 130. The docking element 130 is disposed at the proximal portion of the guide wire 110 and functions as a proximal guide wire extension that enables a physician to better grip the guide wire 110. Thus, the ease of advancing, retracting, and torqueing the guide wire 110 is increased. In one example, the docking element 130 is a proximal wire, and the guide wire 110 is constructed on the outer peripheral surface side of the distal section of the docking element 130. Here, the docking element 130 terminates within the proximal section of the guide wire 110.

[0050] In one example, the proximal section 110a of the guide wire 110 is composed of a stainless - steel core wire, and the distal section 110b of the guide wire 110 (including the tapered section 132 and the reduced - diameter section 134) is composed of a nitinol core wire.

[0051] In one example, the guide wire 110 is about 200 centimeters. The stainless steel core wire including the proximal section 110a extends over about 140 centimeters, and the stainless steel core wire including the distal section 110b extends over about 60 centimeters. The stainless steel coil 114 extends over about 37 centimeters, while the platinum coil 122 covers about 3 centimeters. The shaped length section 120 extends over about 1.4 centimeters. The hydrophilic coating on the distal section of the guide wire 110 extends over about 140 centimeters (covering the distal portion of the guide wire and extending to the distal tip of the guide wire).

[0052] Figures 5-6 show the guide wire 110 of FIG. 4 along within the guide catheter 38. In FIG. 5, the guide wire 110 shows the protrusion 116 and the radiopaque marker 118, and the distal portion of the guide wire 110 is disposed beyond the distal end of the guide catheter 38. In this configuration, the guide wire is used to access near the target treatment site, and subsequently the guide catheter 38 is pushed or moved on the outer peripheral surface side of the guide wire 110.

[0053] In FIG. 6, the guide wire 110 is retracted into the guide catheter 38, or the guide catheter 38 is advanced on the outer peripheral surface side of the guide wire 110. These are performed so that the protrusion 116 contacts and abuts the guide catheter 38 (for example, the protrusion 116 is undersized compared to the lumen of the guide catheter 38, or is slightly oversized but is made of a malleable material that can be deformed and withdrawn into the catheter 38). Alternatively, a combination of advancement / withdrawal techniques can be used. When the protrusion 116 has an expanded shape as shown in FIGS. 4-6, the guide catheter 38 should contact the region of the protrusion 116 having the largest diameter. The guide catheter 38 includes a radiopaque marker 127. The guide wire radiopaque marker 118 is disposed in the same plane as the radiopaque marker 127 of the guide catheter, or the guide wire radiopaque marker 118 is disposed just distal to the radiopaque marker 127 of the guide catheter. In any case, the presence of two radiopaque elements in close proximity to each other increases the imaging of the system when viewed by the user. Thus, the user can know that the two elements are aligned, that the guide wire 110 is compatible with the guide catheter 38, and that the system can be advanced through the vasculature.

[0054] When the guide wire protrusion 116 contacts the guide catheter 38, there is substantially no gap between the guide wire 110 and the guide catheter 38. This helps to mitigate the ledge effect because there is substantially no gap or opening surface where the blood vessel can catch. Usually, the presence of a gap creates a void where the guide catheter may become stuck. However, when the guide wire protrusion 116 is disposed in conformity with the guide catheter 38, there is no such gap, and the protrusion slides relative to the blood vessel so that the guide catheter is not trapped at a blood vessel bifurcation. As described above, the protrusion preferably includes a soft polymer so as to facilitate a sliding effect when the protrusion contacts the blood vessel. An additional hydrophilic coating, an additional lubricious coating, or a lubricious polymer can be used to make the protrusion slidable relative to the blood vessel wall.

[0055] The guide wire 110 in FIGS. 4-6 can be advanced in several different ways. In a first method, the guide wire 110 is deployed distal to the guide catheter 126, and the guide catheter 38 is pushed forward on the outer circumferential surface side of the guide wire 110. If the guide catheter 38 is trapped (e.g., due to the ledge effect), the guide wire 110 is retracted so that the guide wire protrusion 116 contacts the guide catheter 38. Then, the guide catheter 38 is pushed forward, and both the guide wire 110 and the guide catheter 38 advance as a unit. Since the guide protrusion 116 contacts the guide catheter 38, when the guide catheter 38 advances, the guide wire 110 also advances. In a second method, the user places the guide wire protrusion 116 in the distal section of the guide catheter 38 and advances the guide wire 110 and the guide catheter 38 together as a unit through the vasculature. Once the guide catheter 38 is properly positioned, a microcatheter can be moved through the guide catheter, and the guide wire 110 can be withdrawn. Also, a therapeutic agent (e.g., a stent, a coil, a blood clot retrieval device) can be delivered using the microcatheter, or the therapeutic agent can be delivered using the guide catheter 38 itself.

[0056] As previously described with respect to embodiments of the extended microcatheter 10, small gaps may be tolerated as long as they are too small to be trapped in a blood vessel bifurcation. Thus, in some embodiments, a small gap between the guidewire protrusion 116 and the guide catheter 38 may be utilized such that the protrusion 116 does not necessarily contact the guide catheter 38.

[0057] FIG. 6 shows a torquer 128 that is used to lock the guidewire 110 and apply torque. The torquer 128 includes a pushable collet that pushes down and locks the guidewire 110. The torquer 128 can be screwed or rotated to push the collet in and lock the guidewire 110. Alternatively, the torquer 128 includes a movable element linked to the collet and can lock the guidewire 110 via the collet. In FIG. 6, the torquer 128 applied to the proximal section of the guidewire 110 is shown. The torquer 128 is used to lock the guidewire 110. Thus, the guidewire distal tip 120 is in a fixed position relative to the torquer 128. The user locks the guidewire 110 and then advances the guidewire 110 through the vasculature. Since the guidewire 110 is locked in place via the torquer 128, the direction of the curved distal tip 120 will not change unless the torquer 128 rotates. While advancing the guidewire 110 through the blood vessel by pushing the guidewire 110 forward, the torquer 128 enables locking the direction of the guidewire and prevents accidental rotation of the guidewire 110. If the user wants to change the direction of the guidewire 110 when it becomes stuck at a bifurcation, the user can rotate the torquer 128 that rotates the guidewire 110 and change the direction of the guidewire distal tip 120 to align it in another direction.

[0058] In other embodiments, the guide wire protrusion 116 can selectively lock the guide catheter 38. In one example, the protrusion 116 can include a threaded element that mates with a corresponding groove in the guide catheter 38. Thereby, similar to a screw, the two elements can be locked together. In another example, the protrusion 116 can include an enlarged ring that fits into a corresponding recess in the guide catheter 38. In another example, the guide wire protrusion 116 includes a recess, and the guide catheter 38 includes a protruding ring that fits into the recess. The fitting is done by force. Here, when the user applies sufficient force, the elements fit together (lock) and also separate (become unlocked). In one example, when the two elements come into contact with each other or fit together, a torque similar to the above can be used to lock the guide wire 110 relative to the guide catheter 38.

[0059] In the foregoing description, the advantages of the soft polymer used for the guide wire protrusion 116 have been discussed. Here, one advantage is that the material properties of the soft polymer facilitate the sliding contact interface between the guide wire protrusion 116 and the blood vessel. Another advantage of the soft polymer used for the protrusion is its malleability. When the guide wire 116 is withdrawn, the user can retract the guide wire 116 through the guide catheter 38. The malleability of the soft polymer enables the guide wire protrusion 116 to be easily retracted through the guide catheter 38 by being pushed in.

[0060] In one embodiment, the guide wire protrusion 116 includes a soft plastic polymer (specifically, a single polymer piece having a hole through which the guide wire passes). Alternatively, the polymer protrusion can be advanced on the outer peripheral surface side of the guide wire 110. Alternatively, the protrusion may be separately manufactured and attached to the outer peripheral surface side of the guide wire 110 via an adhesive. The protrusion 116 can have a number of shapes, as previously discussed. In particular, the shape of the side surface affects how the protrusion 116 acts in contact with the blood vessel wall. Example shapes of the protrusion 116 include a gentle conical shape as shown as element 116a in FIG. 8, or a concave or convex rounded shape.

[0061] In one example, the proximal portion 110a and the distal portion 110b of the guide wire 110 are manufactured separately. The protrusion 116 is disposed on the outer peripheral surface side of the distal portion 110b of the guide wire 110 using any of the techniques described above. Next, the distal portion 110b and the proximal portion 110a of the guide wire 110 are paired using various techniques such as heat treatment, adhesive, soldering, welding, etc. In another example, the guide wire 110 is manufactured as a single unit, and the protrusion 116 is disposed on the outer peripheral surface side of the distal portion of the guide wire 110 using any of the techniques described above.

[0062] The guide wire 110 can be used with an aspiration / suction catheter. Here, a vacuum source is disposed at the proximal end of the aspiration catheter. Aspiration may be used to assist in blood clot retrieval, removing blood clots remaining within the vascular system using said aspiration. Here, aspiration can be used to seal the guide wire 110 relative to the guide catheter 38. In one example, aspiration is used to seal the guide wire protrusion 16 relative to the guide catheter 38, sealing the gap between the guide wire 110 and the guide catheter 38. Then, aspiration is applied at the proximal end of the guide catheter 38, and while continuing to seal the guide wire protrusion relative to the catheter, the guide catheter 38 is advanced through the vascular system.

[0063] In one embodiment, the distal portion of the guide catheter 38 is radially smaller compared to the remainder of the guide catheter. A guide wire 110 having a protrusion 116 is advanced through the guide catheter 38, while the protrusion 116 contacts the radially reduced distal portion of the guide catheter 126 to seal the gap between the guide catheter 38 and the guide wire 110. The distal tip segment 138 can be made radially smaller as shown in FIG. 7a, or the distal tip 138 can be tapered inwardly to contact the protrusion, as shown in FIG. 7b. In some embodiments, a marker band 129 as shown in FIG. 7a can optionally be used immediately adjacent to the radially reduced region. Here, the guide wire protrusion marker band 118 is aligned with the radially reduced section marker band 129 of the guide catheter 38. Thus, the user can confirm the proper placement of the guide wire 110 relative to the guide catheter 38. In another embodiment, the guide catheter 38 has a relatively constant diameter, and the guide wire protrusion 116 is sufficiently malleable so that when the user advances and withdraws the guide wire 110, the guide wire protrusion 116 collapses to easily pass through the guide catheter 38.

[0064] In one embodiment shown in FIG. 8, the guide wire protrusion 116 is wedge-shaped and has a tapered distal face 116a and proximal face 116b. The tapered proximal face is approximately equal to the diameter of the guide catheter 116 or slightly larger than the diameter of the guide catheter to eliminate any gap between the guide wire 116 and the guide catheter 38. If the guide wire protrusion 116 is slightly larger than the guide catheter 38, the guide wire protrusion should be malleable and allow for pushing to enable the guide wire 110 to be moved (advanced / withdrawn) through the guide catheter 38 without problems.

[0065] Another embodiment shown in FIG. 9 can utilize an intermediate rapid exchange system. Here, an easily deployable device bridges the gap between the guide wire and the guide catheter, and this device can move to the outer peripheral surface side of the guide wire so as to eliminate this gap. In operation, when a conventional guide wire is used and there is a gap between the guide wire and the guide catheter on the outer peripheral surface side, and this gap is caught in a blood vessel branch, the user can move the rapid exchange device on the outer peripheral surface side of the guide wire to eliminate the gap. Alternatively, when the user is operating the guide wire through a branch region, the rapid exchange system can be pre-emptively moved on the outer peripheral surface side of the guide wire to bridge the gap between the guide wire and the guide catheter and reduce potential problems due to the ledge effect.

[0066] FIG. 9 shows a rapid exchange intermediate catheter 151, and a core wire 144 having a proximal handle 144a is utilized for a user to manipulate the catheter 151 (e.g., push it forward and pull it out). The distal portion of the core wire 144 is connected to a tubular portion 148. The tubular portion 148 has a proximal opening 146 and a distal opening 154, and allows the passage of a guide wire 22. The tubular portion 148 can optionally use a radiopaque marker band 152. The guide catheter typically includes a marker band at a point 3 centimeters from the distal tip. Therefore, the marker band 152 of the tubular portion can be used to ensure accurate alignment with the distal tip of the guide catheter. The distal portion of the tubular portion 148 includes an expanded shape or enlarged region 150 that bridges the gap between the tubular portion 148 and the inside of the guide catheter 38. The region 150 is advanced towards the distal tip of the guide catheter 38 such that the gap between the guide wire 151 and the distal opening of the guide catheter 38 is eliminated. In practice, if the user desires to eliminate the guide catheter distal tip gap between the guide wire already deployed within the guide catheter and the guide catheter, the user moves the tubular portion 148 of the rapid exchange system on the outer peripheral surface side of the guide wire. At this time, the system is pushed forward via the core wire 144 until the system is properly positioned such that the enlarged region 150 fills the gap between the guide catheter and the guide wire.

[0067] Note that the figures presented are provided as visual examples to assist in an understanding that aids in interpretation. Sizes and measurements are provided only as examples to assist in understanding and are not meant to be specifically limited to what is literally described.

[0068] Although the present invention has been described with respect to specific embodiments and applications, those skilled in the art can generate additional embodiments and modifications within the scope without departing from the spirit of the invention as set forth in the claims in light of this teaching. Therefore, it should be understood that the drawings and specification of this application are provided as examples to facilitate the understanding of the present invention and should not be construed as limiting its scope.

Claims

1. an elongate member including a proximal portion and a distal portion; a protrusion disposed at or near the distal portion of the elongate member; (1) a radiopaque marker disposed about an exterior of the protrusion; or (2) about an exterior of the elongate member; the protrusion includes an expanded shape having a larger diameter portion, a first reduced diameter portion proximal to the larger diameter portion, and a second reduced diameter portion distal to the larger diameter portion, and the radiopaque marker is disposed about the larger diameter portion of the protrusion.

2. An elongated member including a proximal portion and a distal portion; a protrusion disposed at or near the distal portion of the elongate member; (1) a radiopaque marker disposed about an exterior of the protrusion; or (2) about an exterior of the elongate member; the protrusion comprises a diamond shape having a larger diameter portion, a first reduced diameter portion proximal to the larger diameter portion, and a second reduced diameter portion distal to the larger diameter portion, and the radiopaque marker is disposed about the larger diameter portion of the protrusion.

3. An elongated member including a proximal portion and a distal portion; a protrusion disposed at or near the distal portion of the elongate member; (1) a radiopaque marker disposed about an exterior of the protrusion; or (2) about an exterior of the elongate member; The guidewire, wherein the radiopaque marker comprises a circular marker band secured around a central portion of the projection.

4. The guidewire according to any one of claims 1 to 3, wherein the protrusions are made of a polymer material.

5. The guidewire of any one of claims 1 to 3, wherein the projections taper from a larger diameter or width to a smaller diameter or width in a distal direction.

6. The guidewire according to any one of claims 1 to 3, wherein the radiopaque marker is disposed proximal to the projection.

7. 3. The guidewire of claim 1 or 2, wherein the radiopaque marker comprises a circular marker band secured around a central portion of the projection.

8. The guidewire of any one of claims 1 to 3, wherein the radiopaque marker is disposed distal to the projection.

9. The guidewire of any one of claims 1 to 3, wherein the guidewire includes a first uniform diameter section, a second uniform diameter section, and a tapered section between the first uniform diameter section and the second uniform diameter section.

10. The guidewire of claim 9 , wherein the second uniform diameter section is distal to the first uniform diameter section.

11. The guidewire of any one of claims 1 to 3, wherein the radiopaque marker is disposed proximal to the protrusion and further comprises a second radiopaque marker disposed distal to the protrusion.

12. The guidewire of any one of claims 1 to 3, further comprising a coil extending through the projection.

13. The guidewire of claim 12 , wherein the coil is comprised of a radiopaque portion extending through and passing distally past the distal end of the projection.

14. The guidewire of claim 13 , wherein the coil is comprised of a non-radiopaque portion that extends through and passes proximally past the proximal end of the projection.

15. The guidewire of any one of claims 1 to 3, wherein the guidewire includes a malleable, shaped distal tip extending distally past the projection.

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