Snare device

Abstract

A snare device for retrieving and / or manipulating an object within a space, such as a body cavity. In one embodiment, the snare device includes a support and a core wire. The support includes a proximal portion terminating at a proximal end, a distal portion terminating at a distal end, and a lumen extending distally from the proximal end. The core wire is flexible and has a proximal portion and a distal portion. The distal portion of the core wire and the distal portion of the support are complementarily shaped and fixedly mated to one another, the core wire forming a loop extending away from the distal end of the support, the core wire passing through the lumen, and emerging from the proximal end of the support. The distal portion of the support and the distal portion of the core wire may be complementarily sized helical structures.

Description

Technical Field

[0003]

[0001] [Cross - Reference to Related Applications] This application claims the benefit under 35 U.S.C. § 119 based on U.S. Provisional Patent Application No. 63 / 156,411, filed Mar. 4, 2021, by inventors Eric D. Mathews et al., the disclosure of which is hereby incorporated by reference in its entirety.

[0002] The present invention generally relates to snare devices, and more particularly, to novel snare devices.

Background Art

[0003] There are many situations where it may be desirable to grasp, retrieve, and / or manipulate an object located within a limited space. For example, in the field of medicine, particularly in the field of minimally invasive surgery, there are cases where it may be desirable to grasp, retrieve, and / or manipulate an object or growth within a body cavity, such as a blood vessel. For this purpose, several different types of snare devices have been devised.

[0004] One common type of snare device comprises a wire, typically made of shape-memory material, which forms a distal loop fixed to itself and reversibly deformable between an expanded and folded state. The aforementioned wire is typically used in conjunction with a catheter, which contains a lumen into which the distal loop can be slidably inserted while in its folded state. As the wire moves distal to the catheter, the portion of the distal loop that appears distal beyond the catheter opens from its folded state to an expanded state. (In some snares, commonly called "gooseneck snares," the loop is oriented perpendicular to the catheter lumen.) Conversely, as the wire moves proximal to the catheter, the portion of the distal loop that is drawn into the catheter closes from its expanded state to its folded state. As a result, a snare device can be used to capture an object by positioning the wire distal to the catheter so that the distal loop loosely surrounds the object, and then moving the wire proximal to the catheter until the distal loop is constricted around the object.

[0005] An example of the aforementioned type of snare device is disclosed in Patent Document 1 by the inventors Amplatz et al., published on December 15, 1992, and incorporated herein by reference. More specifically, this patent discloses a snare having an elongated proximal member and a distal segment supported adjacent to the distal end of the proximal member. The distal segment is in the shape of a loop oriented at an angle to the adjacent portion of the proximal member. The proximal member preferably includes two segments of wire forming the distal segment, which may be joined together. An external sheath may also be supported around this integrated wire structure to reduce friction with the catheter. The wire is formed of a shape memory material such as a superelastic nickel-titanium alloy. Due to the superelastic shape memory properties of the material, the wire segments defining the distal segment are able to straighten each other and fold into an elastically deformable configuration so that they automatically open to their original unconstrained configuration when they pass through the lumen of the catheter and exit from the distal tip of the catheter.

[0006] A drawback of the aforementioned type of snare device is that the loop size is fixed once the distal loop is positioned completely beyond the distal end of the catheter. Therefore, if various different loop sizes are desired, multiple snare devices of different sizes must be used. Furthermore, another drawback is that the catheter must be inserted onto the loop-shaped wire to constrict the loop around the object, thus adding radial size to the device and making the overall diameter of the device relatively large compared to the diameter of the wire. This is undesirable as it can exceed the required insertion site, thereby potentially causing complications such as excessive bleeding and / or hematoma. Yet another drawback is that when the loop is pulled back into the catheter (or the catheter is advanced on the loop), the loop tends to close or fold in unpredictable ways, the loop angle changes as it enters the catheter, and the grasped object often slips out of the loop.

[0007] Another common type of snare device comprises a wire and a catheter, with one end of the wire fixed to the outside of the distal end of the catheter, the other end of the wire penetrating the catheter proximally and extending from the proximal end, and a portion of the wire extending distally from the catheter to form a loop. The size of the loop can be adjusted, for example, by pushing the wire distally to the catheter to increase the size of the loop, or by pulling the wire proximally to the catheter to decrease the size of the loop. Thus, a snare device can be used to capture an object by pushing the wire distally to the catheter so that the loop expands, positioning the expanded loop so that it loosely surrounds the object, and then pulling the wire proximally to the catheter until the loop is tightened around the object.

[0008] An example of the aforementioned type of snare device is disclosed in Patent Document 2 of inventor Rappe, published on February 7, 1995, which is incorporated herein by reference. More specifically, the patent discloses a device for retrieving foreign objects, such as vascular occlusive coils or elements, from within a blood vessel, the device comprising a tubular member and a flexible wire extending axially through the tubular member, the distal end of which extends from the distal end of the tubular member, loops back, and is fixed to the distal end of the tubular member to form a loop, the loop of which can be resized by axial movement of the wire relative to the tubular member, and can be used to capture foreign objects and remove them from a blood vessel.

[0009] The drawback of the aforementioned type of snare device is that the method of attaching the wire to the catheter, specifically by fixing the distal end of the wire to the outside (or inside) of the catheter, results in a larger overall diameter of the device, especially at the distal end. Having a large diameter at the distal end is undesirable for use in narrow blood vessels.

[0010] Therefore, in summary, snares are often used to capture and retrieve objects within blood vessels. These objects come in a wide range of shapes and sizes. The arteries, veins, or cardiac chambers in which they are contained also vary considerably in shape and size, as do the intravascular pathways that must be traversed to reach the objects. Guide catheters or guide sheaths are often delivered near the object to be captured by the snare and are used to assist in directional manipulation as the snare loop approaches the object. In a typical gooseneck snare, the distal loop is fully open, the loop is manipulated across the graspable portion of the object, and the loop is then closed. If the loop size cannot be adjusted, the combination of options that can be taken to grasp the object (advancing, retracting, and rotating the snare and / or guide catheter or guide sheath) is limited. Furthermore, clinicians may not know the ideal loop size for capturing an object, and even if they do, or once they do know, clinicians may have to use a snare that is not of the preferred diameter. To provide perspective, snares are not a large item, and gooseneck snares manufactured by one company are sold in 10 different loop diameters. Intervention units equipped with this product are unlikely to hold three or perhaps four or more different loop diameters. Furthermore, snares with very small overall diameters, such as those with a diameter of 0.014 inches or less, are also needed. Such snares may be useful, for example, for retrieving stents in coronary arteries, the brain, or other small vessels.

[0011] Other potentially relevant documents include: Patent Document 3 by inventor Pierce, published June 6, 2006; Patent Document 4 by inventor Mathews et al., published November 25, 2003; Patent Document 5 by inventor Drettler et al., published September 16, 2003; Patent Document 6 by inventor Heuser et al., published April 29, 2003; Patent Document 7 by inventor Mathews et al., published December 31, 2002; Patent Document 8 by inventor Tanaka et al., published May 21, 2002; and Patent Document 8 by inventor Mouri et al., published June 13, 2000. This may include Patent Document 9, Patent Document 10 by inventors Sepetka et al., published on September 3, 1996, Patent Document 11 by inventors Graves et al., published on June 4, 1996, Patent Document 12 by inventors Power, published on January 9, 2020, Patent Document 13 by inventors Mathews et al., published on August 20, 2009, Patent Document 14 by inventors DeMello et al., published on September 18, 2008, and Patent Document 15 by inventors Abrams et al., published on October 12, 2006, all of which are incorporated herein by reference. [Overview of the project]

[0012] The objective of this invention is to provide a novel snare device.

[0013] Another object of the present invention is to provide the above-described snare device that overcomes at least some of the drawbacks associated with existing snare devices.

[0014] Another object of the present invention is to provide the above-mentioned snare device that is easy to manufacture, easy to use, and has a minimal number of parts.

[0015] Accordingly, according to one aspect of the present invention, a snare device is provided, the snare device comprising: (a) a support, comprising a proximal portion terminating at a proximal end, a distal portion terminating at a distal end, and a lumen, the lumen extending distally from the proximal end; and (b) a flexible core wire comprising a proximal portion and a distal portion, wherein the distal portion of the core wire and the distal portion of the support are complementaryly shaped and fixedly fitted together, the core wire forming a loop extending away from the distal end of the support, the core wire passing through the lumen and emerging from the proximal end of the support.

[0016] In a more detailed feature of the present invention, the distal portion of the support and the distal portion of the core wire may be a complementaryly sized helical structure.

[0017] In a more detailed feature of the present invention, the lumen of the support may have a longitudinal axis, and the loop may generally extend along the longitudinal axis.

[0018] In a more detailed feature of the present invention, the lumen of the support may have a longitudinal axis, and the loop may extend substantially perpendicular to the longitudinal axis.

[0019] In a more detailed feature of the present invention, the lumen of the support may extend from the proximal end of the support to the distal end of the support, and the core wire may pass through the distal end of the support.

[0020] In a more detailed feature of the present invention, the support may have a side opening, and the core wire may pass through the side opening.

[0021] In a more detailed feature of the present invention, the support may include a coil, which may include a proximal portion having closely spaced windings and a distal portion having spaced windings.

[0022] In a more detailed feature of the present invention, the support may comprise a coil and a hypo tube, and the coil may be attached to the distal portion of the hypo tube.

[0023] In a more detailed feature of the present invention, the snare device may further include a handle, and the proximal portion of the core wire may be coupled to the handle.

[0024] In a more detailed feature of the present invention, the snare device may further include a sleeve, and the sleeve may be coaxially arranged around the support.

[0025] In a more detailed feature of the present invention, the snare device may further include a tube, and the tube may be coaxially arranged within the support.

[0026] In a more detailed feature of the present invention, the snare device may further include a radiopaque coil, and the radiopaque coil may be coaxially attached around the core wire.

[0027] In a more detailed feature of the present invention, the core wire may be composed of a single filament.

[0028] In a more detailed feature of the present invention, the core wire may include an extended filling tube coaxially surrounding a radiopaque wire.

[0029] In a more detailed feature of the present invention, the core wire may further include a tube coaxially surrounding the proximal portion of the extended filling tube.

[0030] In a more detailed feature of the present invention, the core wire may include a wire cable and a tube, and the tube may be able to coaxially surround the proximal portion of the wire cable.

[0031] In a more detailed feature of the present invention, the snare device may further include two radiopaque coils coaxially attached on the core wire. The first coil of the two radiopaque coils may be arranged more proximally on the core wire and may have an outer diameter smaller than the diameter of the lumen. The second coil of the two radiopaque coils may be arranged more distally on the core wire and may have an outer diameter larger than the diameter of the lumen.

[0032] In a more detailed feature of the present invention, the loop can be resized by moving the proximal end of the core wire relative to the proximal end of the support.

[0033] In a more detailed feature of the present invention, the distal portion of the core wire and the distal portion of the support may be on the same plane as each other.

[0034] The present invention also relates to a method for manufacturing and using the snare device of the present invention.

[0035] For the purposes of this specification and the claims, various relational terms such as “top,” “bottom,” “proximal,” “distal,” “upper,” “lower,” “front,” and “rear” can be used to describe the present invention when it is positioned in a given orientation or viewed from a given orientation. It should be understood that changing the orientation of the present invention may require adjusting certain relational terms accordingly.

[0036] Further objects, features, and advantages of the present invention are, in part, described below, and in part, will become apparent from the description or can be acquired through the practice of the invention. This specification refers to the accompanying drawings, which form part of the invention and illustrate various embodiments for carrying it out. The embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it should be understood that other embodiments may be utilized and structural modifications may be made without departing from the scope of the invention. Therefore, the following detailed description should not be construed as restrictive, and the scope of the invention is best defined by the appended claims. [Brief explanation of the drawing]

[0037] The accompanying drawings incorporated herein and constituting part thereof illustrate various embodiments of the invention and, together with the description, help to illustrate the principles of the invention. These drawings are not necessarily drawn to scale, and certain components may have smaller and / or larger dimensions for illustrative purposes. In the drawings, similar reference numerals represent similar parts. [Figure 1A] This is a partial perspective view of a first embodiment of a snare device configured according to the teachings of the present invention, the snare device being shown with the loop in a relatively contracted state. [Figure 1B] This is a partial perspective view of a first embodiment of a snare device configured according to the teachings of the present invention, the snare device being shown with the loop in a relatively extended state. [Figure 1C] Figure 1A is a partial side view showing the support and core wire of the snare device, with the support and core wire shown disassembled, and the core wire shown not looped. [Figure 2A] This is a partial cross-sectional perspective view of a second embodiment of a snare device configured according to the teachings of the present invention, the snare device being shown with the loop in a relatively contracted state. [Figure 2B] This is a partial cross-sectional perspective view of a second embodiment of a snare device configured according to the teachings of the present invention, the snare device being shown with the loop in a relatively extended state. [Figure 3A] Figure 2A shows a support, and Figure 2B shows an alternative support and sleeve combination, both fragmentary and partially disassembled side views. [Figure 3B] Figure 2A shows a fragmentary, partially disassembled, simplified cross-sectional view of the support shown and Figure 2B shows an alternative support and sleeve combination. [Figure 4] This is a partial side view of a third embodiment of a snare device configured according to the teachings of the present invention, in which part is a cross-section and part is broken. [Figure 5] This is a partial side view, partly a cross-section, of a fourth embodiment of a snare device configured according to the teachings of the present invention. [Figure 6]This is a partially exploded perspective view of a fifth embodiment of a snare device configured according to the teachings of the present invention. [Figure 7] This is a partially exploded perspective view of an alternative embodiment of the core wire. [Figure 8A] This is a series of diagrams illustrating one embodiment of a method for assembling a snare device according to the teachings of the present invention. [Figure 8B] This is a series of diagrams illustrating one embodiment of a method for assembling a snare device according to the teachings of the present invention. [Figure 8C] This is a series of diagrams illustrating one embodiment of a method for assembling a snare device according to the teachings of the present invention. [Figure 9A] A series of figures illustrating one embodiment of a method for mounting one or more radiopaque coils on a core wire according to the teachings of the present invention. [Figure 9B] A series of figures illustrating one embodiment of a method for mounting one or more radiopaque coils on a core wire according to the teachings of the present invention. [Figure 10A] A series of figures illustrating another embodiment of a method for mounting one or more radiopaque coils on a core wire, according to the teachings of the present invention. [Figure 10B] A series of figures illustrating another embodiment of a method for mounting one or more radiopaque coils on a core wire, according to the teachings of the present invention. [Figure 11] This is a perspective view of a sixth embodiment of a snare device configured according to the teachings of the present invention. [Figure 12A] This is a simplified partial cross-sectional view illustrating the use of the snare device according to the present invention for use as a fixed guide wire. [Figure 12B] This is a simplified partial cross-sectional view illustrating the use of the snare device according to the present invention for use as a fixed guide wire. [Figure 12C] This is a simplified partial cross-sectional view illustrating the use of the snare device according to the present invention for use as a fixed guide wire. [Figure 12D]This is a simplified partial cross-sectional view illustrating the use of the snare device according to the present invention for use as a fixed guide wire. [Figure 12E] This is a simplified partial cross-sectional view illustrating the use of the snare device according to the present invention for use as a fixed guide wire. [Figure 13] This document illustrates various exemplary design options and dimensions for the snare device of the present invention. [Modes for carrying out the invention]

[0038] The present invention relates to a snare device for retrieving and / or manipulating an object in a space, where the space is a body cavity ranging in size from, for example, small tortuous vascular structures to larger blood vessels, organs, cavities, etc. In at least some embodiments, the snare device may comprise a support and a core wire. More specifically, in at least some embodiments, at least a portion of the support may be hollow, a first portion of the core wire may be joined to the distal end of the support, for example, using one or more complementary or mating features or structures, a second portion of the core wire may extend from the support, and a third portion of the core wire may extend into the support and be adapted to slide relative to the support, thereby the core wire may form a loop structure extending from the support, the size of which is adjusted by sliding the core wire relative to the support.

[0039] In at least some embodiments, the distal end of the support may include a tubular member, and the wall of the tubular member may further include an angular slot, which may appear helical if the angular slot traverses a considerable angular rotation. The distal end of the core wire may be formed in a shape that fits into the angular slot of the support. For example, in at least some embodiments, the distal end of the support and the distal end of the core wire may be formed as complementary or fitting helices. The support and the core wire may be joined to each other by a process that includes inserting a mandrel between the support and the core wire and rotating the helical end of the core wire within the support. Preferably, the distal end of the core wire may be sized to fit substantially within the distal end of the support. The core wire may be assembled and joined to the support, leaving a lumen open at the distal end. The proximal end of the core wire may be introduced into the distal end of the support or a side opening of the support and then pass through the lumen of the support until it exits the proximal end of the support. Thus, the loop can be made smaller by pulling the core wire proximal, or conversely, larger by pushing the core wire distally. The size ratio of the core wire to the support can potentially make the overall diameter of the device comparable to, or even smaller than, the smallest snare retriever currently available. For larger devices, the core wire can be made more robust as needed.

[0040] In at least some embodiments, the support may comprise a coil, which may be, for example, a metal coil, and the support coil may have a short extension at its distal end. The support coil can be made from typical coiled wire materials, including, for example, MRI-safe 304 stainless steel, MP35N (nickel-cobalt alloy), and Co / Cr alloy. The support coil may include a circular wire or a rectangular flat wire.

[0041] In at least some embodiments, a sleeve can be positioned around the outside of the support coil, which helps to support the support coil and maintain some degree of flexibility while preventing the support coil from stretching or deforming. The sleeve positioned around the coil may be formed from a material such as nylon (polyamide), PEBAX (polyether block amide), PET (polyethylene terephthalate), or PTFE (polytetrafluoroethylene). Instead of being positioned around the outside of the support coil, the sleeve may be positioned inside the support coil. (Alternatively, a first sleeve may be positioned around the outside of the support coil, and a second sleeve may be positioned along the inside of the support coil.) Such a sleeve may include, for example, a PI (polyimide) or nylon (polyamide) tube, which may also be coated on its inner surface with PTFE or other lubricating material. In another embodiment, the sleeve may be formed by an injection adhesive that bridges the coils of the support coil to maintain sufficient flexibility to allow bending while minimizing elongation.

[0042] In at least some embodiments, the support may comprise a tube or similar structure that does not necessarily have to be formed from one or more coiled members. For example, metal tubes, including, but not limited to, 304 stainless steel, Co / Cr alloys, and Nitinol (nickel-titanium alloy), can be modified to include a helical slot at their distal end. To add flexibility, the tube may be variably grooved as needed. Plastic composite tubes can also be used as supports, and materials such as PI, PEBAX, PET, and PTFE can be used and / or combined with a metal braid or coil. The distal end of the support tube can be modified to accept a helical core wire, and such modifications can be easily achieved by currently available and well-known methods and materials.

[0043] In at least some embodiments, the core wire may comprise a single wire or a combination of wires and / or tubes. As an example of a single-wire embodiment, the superelastic material Nitinol can be used. The distal end of the core wire can be reduced in diameter by grinding and then shaped into a desired helical or other mating shape using a forming tool and heat. For helices with a narrow bending radius, the Nitinol wire may be heat-treated or annealed to reduce stiffness according to standard methods. Adjacent to the distal helix, the Nitinol wire can be formed into a desired loop shape. For example, in a manner similar to a gooseneck snare, the core wire may be formed into a loop that is somewhat perpendicular to the axis of the support. More proximal, the core wire can have a larger diameter, which may be useful for advancing and retracting the core wire to change the size of the loop for capture and gripping.

[0044] In at least some embodiments, the core wire may include several materials and / or structures. For example, the core wire may include a smaller diameter wire, which may be made from or contain nitinol, and may be sized and shaped to fit with the helical portion of the support. Furthermore, the core wire may also include a larger diameter tube, which may surround and attach to the smaller diameter wire to facilitate pushing and pulling of the core wire. The small diameter wire may itself be a composite of materials and / or structures. For example, the small diameter wire may include a nitinol tube filled with an X-ray opaque core (e.g., Fort Wayne Metals DFT® wire), which may allow the gripping loop to be viewed under X-ray fluoroscopy. The larger diameter tube surrounding the small diameter wire may include one or more of nitinol, stainless steel, and polymer / metal composites, and the polymer / metal composite may include a combination of PI, PEBAX, nylon, PTFE, metal braids, or metal coils.

[0045] Optionally, the snare device may further comprise a relatively small coil positioned around the gripping loop formed by the core wire. The aforementioned small coil may contain a radiopaque material, such as various platinum, palladium, or tungsten alloys, which may help to facilitate visualization of the loop under X-ray fluoroscopy. The outer diameter of this small coil is preferably such that it can be fitted into the lumen of the support.

[0046] Optionally, the snare device may include an additional coil or tubular member that can surround the core wire and be positioned immediately adjacent to the helical portion of the core wire, the diameter of which is larger than the lumen of the support. In this way, the aforementioned additional coil or tubular member can limit the amount of core wire that can be introduced into the lumen of the support, thereby limiting the sharpness of the angular bends within the loop. Very sharp angular bends in a Nitinol loop can lead to wire breakage, especially if several sharp bends are applied to the loop. The aforementioned additional coil or tubular member may be formed from the same or similar material as described above.

[0047] As suggested above, in at least some embodiments, the core wire used to form the loop may be supplied proximally through an opening at the distal end of the support. In alternative embodiments, the core wire used to form the loop may be supplied proximally through a lateral opening of the support. While this arrangement may not be optimal as it increases the distal outer diameter of the device, such an arrangement can have the safety advantage of reducing the degree of angular bending required for the core wire, thereby reducing the risk of core wire breakage. Furthermore, such an arrangement may result in a change in the gripping shape, which may be preferable for some anatomical configurations.

[0048] The proximal end of the core wire can function as a handle for selectively advancing or retracting the portion of the core wire that forms the loop. The diameter of the core wire at its proximal end can be increased to the same diameter as the support, thereby helping to limit how far the core wire can be inserted and, therefore, how far the loop can be extended or formed. If the proximal end of the core wire is kept below the diameter of the support, the device may be used additionally or alternatively as a guide device or guide wire.

[0049] Another possible application of the snare device of the present invention may be as a fixation device. For example, the snare device may advance through a guiding catheter and be positioned within a blood vessel, at which point the loop may expand to a size larger than the inner diameter of the vessel. Preferably, the loop is positioned at a proximal acute angle so that the loop provides resistance when tension is applied to the proximal end of the support. When deployed in this manner, the snare device can provide foothold support for the guiding catheter, thereby allowing it to remain in place instead of popping out of the hole as other devices advance. Alternatively, when deployed as a fixation device, the snare device can provide a securely positioned rail from which a therapeutic catheter can be advanced.

[0050] Referring here to Figures 1A–1C, partial perspective views of the first embodiment of the snare device in a relatively more contracted state and a relatively more expanded state, the snare device being constructed in accordance with the teachings of the present invention and represented collectively by reference numeral 11. Details of the snare device 11 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from one or more of Figures 1A–1C and / or from the appendix description herein, or may be shown in one or more of Figures 1A–1C and / or described herein in a simplified manner.

[0051] The snare device 11 may include a support 13, a core wire 15, and a handle 17.

[0052] The support 13 may be a substantially cylindrical, one-piece (i.e., single) hollow member and may include a proximal end 19, a distal end 21, and a lumen 23, the lumen 23 may extend substantially longitudinally between the proximal end 19 and the distal end 21. In this embodiment, the support 13 may comprise a coiled filament having a plurality of windings. The windings 25 located at the proximal end 19 of the support 13 and along most of the length of the support 13 may be in direct contact with the proximal and distal windings 25, or they may be relatively closely spaced apart. However, for reasons described below, the windings 26 near the distal end 21 of the support 13 may have short elongations, i.e., they may be spaced relatively far apart from each other.

[0053] In this embodiment, the support 13 may be, for example, a metal coil, and can be made from typical coiled wire materials including, for example, MRI-safe 304 stainless steel, MP35N (nickel-cobalt alloy), and Co / Cr alloy. The coiled wire used to form the support 13 can be selected from any of various different wire shapes, including, for example, circular wire or rectangular flat wire.

[0054] The core wire 15 may be a single (i.e., one) solid member and may include a proximal portion 31, a distal portion 33, and an intermediate portion 35. In this embodiment, the core wire 15 may be made of a shape memory material such as nitinol. The proximal portion 31 may be fixedly coupled to the handle 17. The distal portion 33 may be fixedly coupled to the support 13. More specifically, in this embodiment, the distal portion 33 may be in the shape of a coil having a plurality of winding portions 37. Preferably, the coil structure of the distal portion 33 has an inner diameter substantially matching the inner diameter of the support 13 and an outer diameter substantially matching the outer diameter of the support 13. In addition, the filament diameter of the wire used to form the support 13 and the filament diameter of the core wire 15 are substantially equal, and the windings 37 of the distal portion 33 are preferably spaced at substantially the same pitch as the windings 37 of the support 13 so that the windings 26 of the distal portion 33 can be fitted and joined with the windings 26 that are close to the distal end 21 of the support 13. The fitting of the core wire 15 and the support 13 can be achieved by screwing the windings 37 and 26 together.

[0055] The intermediate portion 35 of the core wire 15 can be drawn through the support 13 to form a distal loop-shaped portion 41 that can extend distally beyond the support 13, and a relatively straight proximal portion 43 that can extend substantially coaxially within the support 13. In this embodiment, the loop-shaped portion 41 may be oriented such that the expansion of the loop-shaped portion 41 is substantially parallel to the longitudinal axis of the support 13.

[0056] As is best seen in Figure 1C, the distal portion 33 and the intermediate portion 35 of the core wire 15 can have a relatively small filament diameter, which can provide greater flexibility, while the proximal portion 31 of the core wire 15 can have a relatively large filament diameter, which can help resist bending during compression.

[0057] The handle 17 can be used to selectively move the core wire 15 proximal and distal to the support 13. As seen in Figure 1A, when the core wire 15 is in a more proximal position to the support 13, the loop portion 41 can be in a more contracted state (i.e., the loop portion 41 can have a relatively small size). In contrast, as seen in Figure 1B, when the core wire 15 is in a more distal position to the support 13, the loop portion 41 can be in a more expanded state (i.e., the loop portion 41 can have a relatively large size). Therefore, the snare device 11 can be used to capture the object by positioning the snare device 11 in the space near the object, moving the core wire 15 distal to the support 13 to surround the object with the loop portion 41, and then retracting the core wire 15 proximal to the support 13 to tighten the loop portion 41 around the object.

[0058] One advantage of the snare device 11 over many conventional snare devices is that the overall diameter of the distal end of the snare device 11 can be kept relatively small. This is because the distal end of the core wire 15 can be fixed to the support 13 by intersecting with the support 13. Such an arrangement eliminates the need to fix the distal end of the core wire inside or outside the support, or the need to fold at least a portion of the core wire within the support, all of which add radial size to the device. Another advantage of the snare device 11 is that the helical structure of the support 13 and the mating of the core wire 15 promote a very strong attachment between these two components, thereby minimizing the risk of detachment between them.

[0059] Referring here to Figures 2A and 2B, partial cross-sectional perspective views of the second embodiment of the snare device in a relatively more contracted and relatively more expanded state, the snare device being constructed in accordance with the teachings of the present invention and represented as a whole by reference numeral 111. Details of the snare device 111 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from one or more of Figures 2A and 2B and / or from the appendix description herein, or may be shown in one or more of Figures 2A and 2B and / or described in a simplified manner herein.

[0060] The snare device 111 may be similar to the snare device 11 in certain respects. For example, the snare device 111 may include a support 113 which may be similar to or identical to the support 13, and a handle 117 which may be similar to or identical to the handle 17. (In this embodiment, a handle 117 having a plurality of longitudinal outer ribs 119 is shown.)

[0061] The snare device 111 may also include a core wire 121. The core wire 121 may be similar in many respects to the core wire 15, one difference being that the core wire 121 may be molded to include a loop-shaped portion 123 that can extend substantially perpendicular to the longitudinal axis of the support 113, whereas the core wire 15 may be molded to include a loop-shaped portion 41 that can extend substantially along the longitudinal axis of the support 13.

[0062] The snare device 111 may further include a sleeve 131. The sleeve 131, which may be a single, integrated (i.e., one) tubular member made of a polymer such as nylon, PREBAX, PET, or PTFE, may be coaxially fitted around the support 113. Using a sleeve 131 that can be heat-shrinkable or otherwise compressed around the support 113 can prevent the support 113 from stretching or deforming while providing the support 113 with some degree of flexibility. The sleeve 131 may or may not be transparent. It should also be understood that the sleeve 131 can be used in the snare device 11.

[0063] The snare device 111 can be used in much the same way as the snare device 11. Due to the shape of the loop-shaped portion 123, the snare device 111 can be used in many types of applications where a gooseneck snare is desired.

[0064] In the snare device 111, the sleeve 131 is positioned around the outside of the support 113, but it should be understood that other types of sleeves may be used, additionally or alternatively, that can be positioned inside the support 113. For example, referring to Figures 3A and 3B, various diagrams of alternative combinations of support and sleeve for the snare device 111 are shown, and the combinations as a whole are represented by reference no. 161.

[0065] Combination 161 may include a support 163 and a sleeve 165. The support 163 may be identical to the support 113. The sleeve 165 may be a single, integrated (i.e., one) tubular member sized to fit snugly inside the support 163. The sleeve 165 may be made of a polymer material such as polyimide and may have a lubricating coating such as PTFE on its inner surface. The sleeve 165 can be fixed inside the support 163 using an adhesive 167.

[0066] It should be understood that combination 161 may be used with the snare device 11 instead of the support 13.

[0067] Instead of using sleeves 131 and / or 165, adhesive can be used to bond adjacent windings of supports 113 and 163, thereby minimizing the occurrence of stretching or distortion.

[0068] Referring here to Figure 4, a partial cross-sectional view of a third embodiment of the snare device is shown in partial cross-section and fractured form, the snare device being constructed in accordance with the teachings of the present invention and represented as a whole by reference no. 211. Details of the snare device 211 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from Figure 4 and / or the accompanying description herein, or may be shown in Figure 4 and / or described herein in a simplified manner.

[0069] The snare device 211 may be similar to the snare device 11 in certain respects. For example, the snare device 211 may include a core wire 15 which may be similar to or identical to the core wire 215, and a handle (not shown) which may be similar to or identical to the handle 17 and is coupled to the proximal end of the core wire 215.

[0070] The snare device 211 may also include a support 221. The support 221 may then comprise a proximal member 223 and a distal member 225. The proximal member 223 of the support 221 may comprise a single, integrated (i.e., one) tubular structure, which in this embodiment may be, for example, a stainless steel hypo tube. The proximal member 223 may be molded to include a proximal portion 227, a distal portion 229, and an intermediate portion 231. The proximal portion 227 may be a relatively large diameter hollow cylindrical structure, the distal portion 229 may be a relatively small diameter hollow cylindrical structure, and the intermediate portion 231 may be a hollow structure whose diameter tapers from the proximal portion 227 to the distal portion 229. An opening 233 may be provided on the side of the proximal portion 227, and the opening 233 is sized to allow the core wire 215 to pass through freely.

[0071] The distal member 225 of the support 221 may comprise a substantially cylindrical, one-piece (i.e., single) hollow structure. More specifically, the distal member 225 may comprise a coiled filament having a plurality of winding portions 235. In this embodiment, the distal member 225 may be made from, for example, a stainless steel wire. At least some of the winding portions 235 of the distal member 225 may be appropriately spaced apart to fit with and join to a winding portion 239 located at the distal end of the core wire 215 in a manner similar to that described above in relation to the snare device 11. The distal member 225 of the support 221 may be coaxially inserted onto and fixed to the proximal member 223 of the support 221. Preferably, the outer diameters of the proximal member 223 and the distal member 225 are similar.

[0072] The snare drum unit 211 can be used in much the same way as the snare drum unit 11.

[0073] One advantage of the snare device 211 is that, compared to the snare device 11, the fact that the core wire 215 is supplied into the support 221 through the opening 233 reduces the degree of angular bending that may be required of the core wire 215 compared to when it is supplied through the distal end of the support 221, thereby reducing the risk of core wire breakage (which can pose a safety hazard). Furthermore, due to the way the core wire 215 is supplied into the support 221, the snare device 211 can have a different loop shape than the snare device 11, and this difference may be preferable in some anatomical configurations. On the other hand, due to its structure, the snare device 211 may have a larger outer diameter than the snare device 11, which may be undesirable in some situations.

[0074] Referring here to Figure 5, a partial side view of a fourth embodiment of the snare device is shown in partial cross-section, the snare device being configured according to the teachings of the present invention and represented as a whole by reference no. 311. Details of the snare device 311 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from Figure 5 and / or the accompanying description herein, or may be shown in Figure 5 and / or described herein in a simplified manner.

[0075] The snare device 311 may be similar to the snare device 11 in certain respects. For example, the snare device 311 may include a core wire 15 which may be similar to or identical to the core wire 315, and a handle (not shown) which may be similar to or identical to the handle 17 and is coupled to the proximal end of the core wire 315.

[0076] The snare device 311 may also include a support 321. The support 321 may comprise a coil 323 and a tube 325. The coil 323 may be a substantially cylindrical, one-piece (i.e., single) hollow member made from a coiled filament such as stainless steel wire. The coil 323 may be shaped to comprise a proximal portion 327, a distal portion 329, and an intermediate portion 331. The proximal portion 327 may include a plurality of windings 333 that can be spaced relatively close to each other. In contrast, the distal portion 329 may include a plurality of windings 335 that can be spaced relatively far apart from each other, and the spacing between the windings 335 is preferably sufficient to allow the windings 335 to be fitted and joined with the windings 339 at the distal end of the core wire 315 in a manner similar to that described above for the snare device 11. The intermediate portion 331 is spaced a distance sufficient to define the side opening 341 between the proximal portion 327 and the distal portion 329, and the side opening 341 is sized to allow the core wire 315 to pass through them freely.

[0077] For example, a tube 325, which may be a braided microcatheter, may be coaxially inserted into the proximal portion 327 of a support 321 and joined thereto to provide support to the proximal portion 327.

[0078] The snare device 311 may further include a radiopaque coil 351 coaxially inserted over at least a portion of the loop-shaped portion of the core wire 315. The radiopaque coil 351 can be used to facilitate visualization of the loop-shaped portion of the core wire 315.

[0079] The snare drum unit 311 can be used in much the same way as the snare drum unit 11.

[0080] Referring here to Figure 6, a partially exploded perspective view of a fifth embodiment of the snare device is shown, which is configured according to the teachings of the present invention and is represented as a whole by reference no. 411. Details of the snare device 411 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from Figure 6 and / or the accompanying description herein, or may be shown in Figure 6 and / or described herein in a simplified manner.

[0081] The snare device 411 may be similar in certain respects to the snare device 11 and may include a support 413, a core wire 415, and a handle (not shown). The support 413 may be similar to the support 13, except that a thin adhesive layer 419 may be applied to at least a portion of the outside of the support 413, which may perform a similar function to the sleeve 131 of the snare device 111.

[0082] The core wire 415 may have the same overall size and shape as the core wire 15 and may comprise multiple components. For example, in this embodiment, the core wire 415 may comprise a stretched filling tube 427 and an outer tube 429 of a certain length. The stretched filling tube 427 may comprise a core 431 and a sheath 433. The core 431 may include a radiopaque material (e.g., Pt, Pd, Ag, Au, Ta). The sheath 433, which can coaxially surround the core 431, may include nitinol or a similar material. The outer tube 429 may function to add rigidity to the stretched filling tube 427 to prevent bending during indentation and may coaxially surround and bond the proximal portion of the stretched filling tube 427. The outer tube 429 may be made of materials such as nitinol, polyimide, PEBAX, nylon, and PTFE composite materials. To improve the lubricity of the outer tube 429, a PTFE coating (not shown) can be applied to the outside of the outer tube.

[0083] The snare drum unit 411 can be used in much the same way as the snare drum unit 11.

[0084] One of the advantages of the snare device 411 is that by incorporating the radiopaque material into the core wire itself, it is not necessary to arrange a radiopaque coil around the outside of the core wire. This allows the overall diameter of the distal end of the snare device 411 to be very small, for example, about 0.014 inches.

[0085] Referring here to Figure 7, an alternative embodiment of the core wire configured according to the teachings of the present invention is shown, the core wire as a whole being represented by reference no. 511. Details of the core wire 511 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from Figure 7 and / or the accompanying description herein, or may be shown in Figure 7 and / or described herein in a simplified manner.

[0086] The core wire 511 can be used in place of any of the core wires 15, 121, 215, 315, and 415, and may comprise a proximal member 513 and a distal member 515. The proximal member 513 may comprise a tube that can provide some support to the distal member 515, thereby improving the pushability of the core wire 511. The distal member 515 may comprise a wire strand or cable that can be made of nitinol or the like. The proximal portion 517 of the distal member 515 may be coaxially inserted into the proximal member 513 and fixedly mounted within the proximal member. The distal portion of the distal member 515 may be formed into a coiled portion 519 and a loop 521. Although not shown, a radiopaque coil or the like may be inserted on top of the loop 521.

[0087] Some of the advantages of wire strands or cables like distal member 515 are improved flexibility (reduced stiffness), higher damage resistance, and better fatigue performance under repeated bending compared to a single wire of the same diameter (see Reedlunn et al., "Superelastic shape memory alloy Cables: Part I-Isothermal tension experiments," International Journal of Solids and Structures, 50:3009-3026 (2013), which is incorporated herein by reference).

[0088] Referring here to Figures 8A–8C, a series of diagrams illustrating one embodiment of a method for assembling a snare device according to the teachings of the present invention are shown. Details of methods discussed elsewhere in this application or that are not important to understanding the present invention may be omitted from one or more of Figures 8A–8C and / or from the appendix description herein, or may be shown in Figures 8A–8C and / or described herein in a simplified manner.

[0089] As shown in Figure 8A, the method can be initiated by providing a support 613, a core wire 615, and a mandrel 617. The support 613 may be the same as the support 13 and may comprise a stainless steel coil having a distal extension 614. The core wire 615 may be the same as the core wire 15 and may comprise a nitinol wire formed to include a proximal portion 621, a distal portion 623, and an intermediate portion 625. The proximal portion 621 may have a relatively large filament diameter, the distal portion 623 may have a relatively small filament diameter, and the intermediate portion 625 may have a filament diameter that steadily tapers from the filament diameter of the proximal portion 621 to the filament diameter of the distal portion 623. The distal portion 623 may be formed to include a coiled portion 629, for example by thermosetting, and the coiled portion 629 may have a size and shape complementary to the size and shape of the distal extension 614 of the support 613. The mandrel 617 may include a substantially cylindrical member having a diameter that is larger than the diameter of the proximal portion 621 of the core wire 615.

[0090] Next, as can be seen in Figure 8B, the mandrel 617 can be inserted coaxially through the support 613 and through the coiled portion 629 of the core wire 615, and the distal extension 614 of the support 613 and the coiled portion 629 of the core wire 615 can be fitted together (using adhesive 630) and joined to each other, so that the distal extension 614 and the coiled portion 629 can define a hollow joint together.

[0091] Next, as shown in Figure 8C, the mandrel 617 can be removed, and the proximal end 633 of the core wire 615 can be inserted into the hollow joint defined by the distal extension 614 and the coiled portion 629, and then inserted through the rest of the support 613.

[0092] As described above, for example, in relation to the snare device 311, it may be desirable to arrange one or more radiopaque coils around the loop portion of the core wire to facilitate visualization of the loop portion of the core wire. Referring here to Figures 9A and 9B, a series of figures are shown illustrating one embodiment of a method for mounting one or more radiopaque coils on the core wire according to the teachings of the present invention. Details of methods discussed elsewhere in this application or that are not important to understanding the present invention may be omitted from one or more of Figures 9A and 9B and / or from the appendix description herein, or may be shown in Figures 9A and 9B and / or may be described in a simplified manner herein.

[0093] As shown in Figure 9A, the method can be initiated by providing a core wire 711. The core wire 711, which may be made of nitinol or the like, may be shaped to include a proximal portion 713 with a relatively large diameter, a distal portion 715 with a relatively small diameter, and an intermediate portion 717 whose diameter gradually tapers from the proximal portion 713 to the distal portion 715. The first radiopaque coil 721 and the second radiopaque coil 723 may be coaxially inserted and joined on the distal portion 715 of the core wire 711, with the proximal end of the first radiopaque coil 721 positioned at the interface between the distal portion 715 and the intermediate portion 717, and the proximal end of the second radiopaque coil 723 in contact with the distal end of the first radiopaque coil 721. The first radiopaque coil 721 may be tightly wound and may have an outer diameter substantially equal to the diameter of the proximal portion 713. The second radiopaque coil 723 may have an outer diameter exceeding the outer diameter of the proximal portion 713.

[0094] Next, as shown in Figure 9B, the method can be continued with a shaping step in which the most distal portion of the distal section 715 is wrapped around the mandrel and heat-set to form a coiled structure.

[0095] Referring here to Figures 10A and 10B, a series of diagrams are shown illustrating another embodiment of a method for mounting one or more radiopaque coils onto a core wire according to the teachings of the present invention. Details of the method discussed elsewhere in this application or that are not important to understanding the present invention may be omitted from one or more of Figures 10A and 10B and / or from the appendix description herein, or may be shown in Figures 10A and 10B and / or may be described in a simplified manner herein.

[0096] As shown in Figure 10A, the method can be initiated by shaping the core wire 811. More specifically, the core wire 811, which may comprise a nitinol wire with a constant filament diameter over its length, can be wound around a mandrel 812, held in place by a spring clamp 813, and heat-set to form a coiled structure.

[0097] Next, as shown in Figure 10B, the method can be continued by sliding the first radiopaque coil 821 and the second radiopaque coil 823 coaxially distally on the straight portion of the core wire 811, and joining the coils 821 and 823 to the core wire 811. The first radiopaque coil 821, which may be positioned further distally, may have a relatively large outer diameter, and the second radiopaque coil 823, which may be positioned further proximal, may have a relatively small outer diameter. Next, a tube 825, which makes it easier to push the core wire 811, can be inserted and joined on the proximal portion of the core wire 811.

[0098] Referring here to Figure 11, a partial perspective view of a sixth embodiment of the snare device is shown, which is configured in accordance with the teachings of the present invention and is represented as a whole by reference numeral 911. Details of the snare device 911 that are discussed elsewhere in this application or are not important to understanding the present invention may be omitted from Figure 11 and / or the appendix description herein, or may be shown in Figure 11 and / or described herein in a simplified manner.

[0099] The snare device 911 may be similar to the snare device 11 in certain respects. For example, the snare device 911 may include a support 913 which may be similar to or identical to the support 13, and a core wire 915 which may be similar to or identical to the core wire 915. (The snare device 911 may further include a handle (not shown) which may be similar to or identical to the handle 17.)

[0100] The snare device 911 may differ from the snare device 915 in that the snare device 11 may further comprise two radiopaque coils 921 and 923, which may be coaxially inserted on the core wire and bonded to the core wire with adhesive 924. The radiopaque coil 921 may be sized such that its outer diameter is smaller than the inner diameter of the support 913, thereby allowing the radiopaque coil 921, and the portion of the core wire 915 surrounded by the radiopaque coil 921, to be drawn into the central lumen of the support 913. In contrast, the radiopaque coil 923 may be sized such that its outer diameter is larger than the inner diameter of the support 913. As a result, the radiopaque coil 923, and the portion of the core wire 915 surrounded by the radiopaque coil 923, may not be drawn into the support 913. As a result, the radiopaque coil 923 can function to limit the extent to which the core wire 915 can be drawn into the support 913, and in doing so can function to limit the loop bending radius 931 of the core wire 915. This is advantageous because if the loop bending radius 931 becomes too small, the core wire 915 may break, especially after several cycles of loop expansion and contraction.

[0101] As described above, the snare device of the present invention can be used to capture objects in space. An alternative use of the snare device of the present invention is as a fixed guidewire. For example, referring here to Figures 12A to 12E, the use of the snare device of the present invention as a fixed guidewire in a body cavity such as a blood vessel is shown.

[0102] For this purpose, Figure 12A shows a snare device 951 advancing to a desired position within a blood vessel 953. As can be seen, during such advancement, the loop of the snare device 951 is preferably in a contracted state. In Figure 12B, the snare device 951 is positioned in the desired location, and its loop is expanded until it presses against the blood vessel 953. As can be seen, the angle of the loop is almost perpendicular to the longitudinal axis of the blood vessel 953. This can be undesirable because, as shown in Figure 12C, a proximal force may cause the loop to disengage. Consequently, it may be desirable to use a snare device such as the snare device 971, which has a loop that is slightly inclined proximal, as shown in Figure 12D. In this way, when a proximal force is applied, the loop is more securely fixed within the blood vessel. As can be understood, such fixation can be improved by wrapping a coil coaxially around the loop. With a snare device 971 fixed in this way, the support 973 can be used as a guidewire to deliver medical instruments, etc., into the space immediately proximal to the loop.

[0103] Another potential application of the snare device of the present invention may be cauterization using a loop.

[0104] Referring now to Figure 13, various exemplary design options and dimensions of the snare device of the present invention are shown.

[0105] It should be understood that the features of the various snare devices disclosed herein can be combined in various ways.

[0106] Further objectives, features, and advantages of the present invention are described below. The flexible longitudinal support defines the axis and lumen. The support has a constrained length (it does not expand or contract). The support has a spiral gap at its distal end. The support includes an open lumen near the distal end, which can be either the distal or proximal end. The support structure consists of metal coils and sleeves (mast and stays). The sleeve is secured to the coil either on the outside or inside of the coil. The sleeve supports the integrity of the coil. The sleeve ensures the specified length of the support. The sleeve allows for the desired flexibility in the coil. Sleeve made of polymer Outer sleeve polymer made from nylon, Pebax, PET, or PTFE The inner sleeve polymer is a PI pipe, Pebax pipe, or composite material containing PTFE in its inner diameter. The sleeve is formed by adding adhesive to bridge the coil. The support structure includes a tube. The tubes are made of metal (e.g., SS, CoCr, nitinol). The tube is grooved as needed to provide flexibility. The tube is made of composite polymer. The composite includes metal (braid or coil). The composite includes a distal member for receiving a helical wire. A flexible core wire having a distal end and a proximal end, wherein the distal and proximal ends are largely constrained within a support and the core wire extends through the support.

[0107] The distal end of the core wire is formed in a helical shape that loops back, mates with the distal end of the support, and joins to the distal end of the support, having substantially the same helical pitch and fitting within the OD / ID constraints of the distal end of the support. Core wire made from superelastic metal wire Core wire made with Nitinol Core wire made from nitinol tube containing RO material The distal region of the spiral-shaped core wire is formed into a loop shape oriented at an angle away from the support axis. The distal region of the core wire has a smaller profile than the proximal region. Core wire made from rigid polymer or composite materials such as polyimide / PTFE and / or polyimide / metal braid / PTFE and / or nylon / wire. A core wire having a constant diameter and covered more proximal to a tube, wherein the tube serves to reinforce the core member for forward movement.

[0108] A small coil made of radiopaque (RO) material, which surrounds a distal core wire loop region having an outer diameter that fits and slides within the inner diameter of a support, and is bonded to the distal core wire loop region. To allow for easier sliding within the support coil, it would be advantageous to manufacture the RO coil with an opposite winding angle to the support coil (e.g., the support coil is right-handed wound, and the RO coil is left-handed wound).

[0109] The second RO coil surrounds the distal core wire loop, which has an outer diameter larger than the inner diameter of the support, and is joined to the distal core wire loop, limiting the loop size so that it does not become too small or completely retract into the support. The proximal end of the core is advanceable and retractable by the clinician to form a variable loop size at the distal end, which is suitable for capturing the desired object.

[0110] The proximal end of the core wire extends beyond a support having a tubular cover bonded to the core and is positioned to provide a stopper relative to the support, limiting the loop size by restricting the amount the core can advance.

[0111] The embodiments of the present invention described above are intended to be merely illustrative, and those skilled in the art will be able to make numerous variations and modifications without departing from the spirit of the invention. For example, features from one or more of the embodiments described above may be combined in various permutations. All such variations and modifications are intended to be within the scope of the invention as defined in the appended claims. [Prior art documents] [Patent Documents]

[0112] [Patent Document 1] Patent No. 5,171,233 specification [Patent Document 2] U.S. Patent No. 5,387,219 [Patent Document 3] U.S. Patent No. 7,058,456 [Patent Document 4] U.S. Patent No. 6,652,536 [Patent Document 5] U.S. Patent No. 6,620,172 [Patent Document 6] U.S. Patent No. 6,554,842 [Patent Document 7] U.S. Patent No. 6,500,185 [Patent Document 8] U.S. Patent No. 6,391,018 [Patent Document 9] U.S. Patent No. 6,074,378 [Patent Document 10] U.S. Patent No. 5,551,443 [Patent Document 11] U.S. Patent No. 5,522,819 [Patent Document 12] U.S. Patent Application Publication No. 2020 / 0008926 [Patent Document 13] U.S. Patent Application Publication No. 2009 / 0209987 Specification [Patent Document 14] U.S. Patent Application Publication No. 2008 / 0228209 [Patent Document 15] U.S. Patent Application Publication No. 2006 / 0229638

Claims

1. A snare drum device, (a) A support comprising a proximal portion terminating at a proximal end, a proximal portion terminating at a distal end, and a lumen, wherein the lumen extends distally from the proximal end, (b) A snare device comprising a flexible core wire having a proximal and distal portion, wherein the distal portion of the core wire and the distal portion of the support are helical structures having complementary shapes and dimensions and are fixedly fitted together, the core wire forming a loop extending away from the distal end of the support, the core wire passing through the lumen and emerging from the proximal end of the support, the loop being sized by moving the proximal end of the core wire relative to the proximal end of the support.

2. The snare device according to claim 1, wherein the lumen of the support has a longitudinal axis, and the loop extends substantially along the longitudinal axis.

3. The snare device according to claim 1, wherein the lumen of the support has a longitudinal axis, and the loop extends substantially perpendicular to the longitudinal axis.

4. The snare device according to claim 1, wherein the lumen of the support extends from the proximal end of the support to the distal end of the support, and the core wire passes through the distal end of the support.

5. The snare device according to claim 1, wherein the support has a side opening, and the core wire passes through the side opening.

6. The snare device according to claim 1, wherein the support comprises a coil, the coil comprising a proximal portion having closely spaced winding portions and a distal portion having spaced winding portions.

7. The snare device according to claim 1, wherein the support comprises a coil and a hypo tube, and the coil is attached to the distal portion of the hypo tube.

8. The snare device according to claim 1, further comprising a handle, wherein the proximal portion of the core wire is coupled to the handle.

9. The snare device according to claim 1, further comprising a sleeve, the sleeve being coaxially arranged around the support.

10. The snare device according to claim 1, further comprising a tube, the tube being coaxially arranged within the support.

11. The snare device according to claim 1, further comprising a radiopaque coil, the radiopaque coil being coaxially mounted around the core wire.

12. The snare device according to claim 1, wherein the core wire consists of a single filament.

13. The snare device according to claim 1, wherein the core wire comprises an extended filling tube coaxially surrounding a radiopaque wire.

14. The snare device according to claim 13, wherein the core wire further comprises a tube coaxially surrounding the proximal portion of the stretched filling tube.

15. The snare device according to claim 1, wherein the core wire comprises a wire cable and a tube, and the tube coaxially surrounds the proximal portion of the wire cable.

16. The snare device according to claim 1, further comprising two radiopaque coils coaxially mounted on the core wire, wherein the first of the two radiopaque coils is positioned more proximal to the core wire and has an outer diameter smaller than the diameter of the lumen, and the second of the two radiopaque coils is positioned more distal to the core wire and has an outer diameter larger than the diameter of the lumen.

17. The snare device according to claim 1, wherein the distal portion of the core wire and the distal portion of the support have matching outer diameters.

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