Patent Description:
Guidewires are known in the art along with large bore catheters. However, passing a large bore catheter over a guidewire to its location within the neurovascular can be challenging given the size differential. Typically, an intermediate catheter is used that is sized between the devices to help with transition or opening the distal end of the large bore catheter. Using a second catheter can be a waste of resources and also time as the user needs to advance the intermediate catheter prior to the large bore catheter.

<CIT> describes a wire guide having a wire core and a braided sheath. The wire core includes a proximal end and distal end, wherein the braided sheath is attached to the distal end of the wire core and serves as a flexible pulling section. The braided sheath is woven of a plurality of strands and may be made of various material based on the application, such as stainless steel, a shape memory alloy, or a radiopaque material. The wire guide has a flexible tip at the proximal end opposite the flexible pulling section. A stiff section is provided between the flexible tip and the flexible pulling section to allow manipulation of the wire guide through a body lumen. Proximate the distal end of the wire core a tapered section is provided to increase flexibility of the wire guide toward the distal end. The braided sheath is received over and attached to the wire core. In addition, a shoulder is provided in the wire core providing a smooth transition from the wire core to the braided section. The braided sheath extends from the shoulder beyond the distal end of the wire core.

<CIT> describes an intravascular expansion guide wire and a preparation method thereof. The technical problem to be solved is to pre-expand the stenotic part of the blood vessel, so that the balloon with the preloaded bracket can pass through the stenotic lesion part of the blood vessel. The intravascular expansion guide wire adopted in the present invention is provided with a core wire, the middle part of the core wire is an expansion part, and the outer diameter of the expansion part is larger than the outer diameter of the core wire. The preparation method of the present invention comprises the following steps: <NUM>. making a guide wire head; <NUM>. making a core wire; and <NUM>. assembling a guide wire head on the core wire to obtain an intravascular expansion guide wire. Compared with the prior art, the present invention pre-expands the stenotic section of the blood vessel by using the part with the largest diameter of the expansion guide wire, so that the inner cavity of the stenotic section becomes larger, thereby facilitating the passage of the balloon through the stenotic section.

<CIT> describes a guide wire. The guide wire comprises a far end, a near end and a core wire, the core wire is positioned in a guide wire body and extends from the near end to the far end, a dilating portion is arranged on the core wire, the diameter of the dilating portion is larger than that of the core wire, and a safety net is arranged at a head end, positioned at the far end, of the core wire and is fixedly connected with the head end. The invention further discloses a preparation method of the guide wire. By additionally arranging the safety net at the head end, positioned at the far end, of the core wire, loss of torsion/torque transmission of the guide wire is reduced, and softness and non-deformability of the far end of the guide wire are guaranteed while the phenomenon of 'tail whipping' is eliminated; by arranging the dilating portion on the guide wire, a narrow portion can be pre-dilated by a radial support effect, and an inner cavity of the narrow portion can be dilated to allow a balloon to pass through conveniently. The dilating portion of the pre-dilating guide wire is perfectly round, smooth and soft and cannot cause wounds to blood vessels.

<CIT> describes a guidewire <NUM> including a distal section <NUM>, a proximal section <NUM> and a middle section <NUM> disposed between the distal section and the proximal section, wherein the middle section has a flexural stiffness that is greater than a flexural stiffness of both of the distal section and the proximal section. The distal section is configured for insertion into a vasculature of a patient. A diameter of the middle section may be greater than a diameter of the distal section. The guidewires may include a tapered distal transition portion disposed between the distal section and the middle section and a solid core wire extending a length of the guidewire, the solid core wire including a first diameter extending along the distal section, a second diameter extending along the proximal section, and a third diameter extending along the middle section, wherein the third diameter is greater than the first and second diameters.

<CIT> describes a guide wire <NUM> which includes a first distal end part <NUM> as one distal end area and a second distal end part <NUM> as the other distal end area on the opposite side to the first distal end part <NUM>. The proximal end of the first distal end part <NUM> and the proximal end of the second distal end part <NUM> are bonded to each other, and the insert direction of the guide wire <NUM> is changed to insert both the distal end of the first distal end part <NUM> and the distal end of the second distal end part <NUM> in a lumen such as a blood vessel. Since the outside diameter of the first distal end part <NUM> is smaller than that of the second distal end part <NUM>, the first distal end part <NUM> has higher flexibility than the second distal end part <NUM>.

Examples of the present invention of an access guide wire that can have a section that includes larger outer diameter (OD) portion to bridge gap between guidewire OD of <NUM> inch or <NUM> inch and a large bore catheter inner diameter (ID) of <NUM> (<NUM> inch). These sizes are important when accessing the distal neurovascular, there is a gap between the ID of large bore catheters and guidewire ODs used in gaining access to distal cerebral vessels such as the ICA and the M1/M2.

The above and further aspects of this invention are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. The figures depict one or more implementations of the inventive devices, by way of example only, not by way of limitation.

Specific examples of the present invention are now described in detail with reference to the Figures, where identical reference numbers indicate elements which are functionally similar or identical. Accessing the various vessels within the vascular, whether they are coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of a number of conventional, commercially-available accessory products. These products, such as angiographic materials, rotating hemostasis valves, and large and intermediate catheters are widely used in laboratory and medical procedures. When these products are employed in conjunction with the system and methods of this invention in the description below, their function and exact constitution are not described in detail. While the description is in many cases in the context of neurovascular treatments, the systems and methods may be used for other procedures and in other body passageways as well.

<FIG> illustrates an example of an access guidewire <NUM> of the present invention. A typical prior art guidewire has a uniform diameter across its length. The access guidewire <NUM> has a length L, a distal portion <NUM>, and intermediate portion <NUM>, and a proximal portion <NUM>. The distal portion <NUM> can have a length La, the intermediate portion <NUM> has a length Lb and the proximal portion has a length Lc. The intermediate portion <NUM> can have an increased diameter ΦB in relation to the distal portion diameter ΦA and the proximal portion diameter ΦC (see <FIG>). In <FIG> the distal portion diameter ΦA and the proximal portion diameter ΦC can be equal while the intermediate portion diameter ΦB is larger. The increased diameter portion <NUM> can be same material as the rest of the guidewire <NUM>, just formed with a larger circumference/diameter.

<FIG> illustrates that the distal portion <NUM> can retain its flexibility along its length La as is typical for a guidewire. The increased diameter portion <NUM> can have reduced flexibility or retain flexibility consistent with the distal portion <NUM>. In this example, the proximal portion <NUM> can be the portion proximal the increased diameter portion <NUM> and extend to the operator. The flexibility of the proximal portion <NUM> can mirror that of a typical guidewire or have differential flexibility along its length as may be necessary to deliver it to the neurovascular region of a patient.

<FIG> illustrates an example where the intermediate portion <NUM> and the increased diameter portion <NUM> are made of the same material. <FIG>, <FIG> illustrate examples where the increased diameter portion <NUM> can be separately provided on the intermediate portion <NUM>.

<FIG>, <FIG>, illustrate an example where the access guidewire <NUM> has a uniform diameter across the distal portion <NUM>, the intermediate portion <NUM>, and the proximal portion <NUM>. Instead, as in <FIG>, the increased diameter portion <NUM> can be formed over the intermediate portion <NUM>. In one example, the increased diameter portion <NUM> can be a soft reflowed jacket over the guidewire <NUM> with tapered ends <NUM>.

<FIG> illustrates that the increased diameter portion <NUM> can have an outer tube <NUM> or composite tube which can also have a coil/braid support. The tapered ends <NUM> can be the adhesive bond that holds the outer tube <NUM> in place and is filleted to allow for a smooth transition. In one example, the outer tube <NUM> can be made of Pebax 25D or 35D or Neusoft Jacket 42A/62A.

<FIG> illustrates a two-tube example for the increased diameter portion <NUM>. Here the outer tube <NUM> is placed over an inner tube <NUM> and the inner and outer tubes <NUM>, <NUM> are reflowed to form the increased diameter portion <NUM>. In this example, the outer tube <NUM> can be made of Pebax 25D or 35D while the inner tube <NUM> can be made of Neusoft 42A/62A.

<FIG> illustrates a variant example of <FIG>, here a coil <NUM> is placed inside the outer tube <NUM> to provide strength and kink resistance. Note that in the variant of increased diameter portion <NUM> of <FIG>, the outer tube <NUM> and the inner tube <NUM> are reflowed to have tapered profile. The inner coil <NUM> offers kink resistance with thin flexible outer tubes <NUM>. The inner coil <NUM> can be free floating or the outer tube <NUM> can be reflowed through it. The inner coil <NUM> cand be replaced with a braid (not illustrated).

<FIG> illustrates an example where the distal section <NUM> can have smaller diameter ΦA (i.e. a lower profile) than the proximal section <NUM> (ΦC). Thus, the proximal portion <NUM> can be thicker for greater pushability and handling, with a smaller distal section/tip <NUM> for atraumatic clot crossing.

<FIG> illustrate an example of the increased diameter portion <NUM> with a stepped, fluted mid-section <NUM>. Fluted mid-section <NUM> can be used to provide a smooth transition when used with a funnel catheter <NUM> to help expand the tip <NUM> of the catheter <NUM>. The flutes <NUM> can be thin and soft so that they can be collapsed and retrieved through the body <NUM> of the funnel catheter <NUM>.

Turning to examples of the intermediate/increased diameter portion <NUM>, <NUM>, <NUM>, <NUM>, <NUM>:.

Examples of the device <NUM> can be used with a large bore intermediate catheter (<NUM> - <NUM> (<NUM> inch - <NUM> inch) ID approximately), a superbore catheter (<NUM> - <NUM> (<NUM> inch - <NUM> inch) approximately), or a funnel catheter (shaft ID of <NUM> - <NUM> (<NUM> inch - <NUM> inch) approximately).

The invention is not necessarily limited to the examples described, which can be varied in construction and detail. The terms "distal" and "proximal" are used throughout the preceding description and are meant to refer to a positions and directions relative to a treating physician. As such, "distal" or distally" refer to a position distant to or a direction away from the physician. Similarly, "proximal" or "proximally" refer to a position near to or a direction towards the physician. Furthermore, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Claim 1:
An access guidewire (<NUM>), comprising:
a distal portion (<NUM>) comprising a distal portion length (La) and a distal portion diameter (ΦA);
an intermediate portion (<NUM>), proximal to the distal portion (<NUM>), comprising an intermediate portion length (Lb) and an intermediate portion diameter (ΦB); and
a proximal portion (<NUM>), proximal of the intermediate portion (<NUM>), comprising a proximal portion length (Lc) and a proximal portion diameter (ΦC);
wherein the intermediate portion diameter is greater than the distal portion diameter (ΦA) and the proximal portion diameter (ΦC),
characterised in that the intermediate portion length (Lb) is <NUM> to <NUM>.