JP6159935B1 - Medical guidewire - Google Patents

Abstract

An object of the present invention is to provide a medical guide wire capable of more easily discriminating a difference in touch transmitted to a fingertip between a true cavity and a false cavity. A medical guide wire 10 according to the present invention includes a core wire 11 and a coil 30 fixed coaxially on the distal end of the core wire 11. In the medical guide wire 10, the coil 30 has a bamboo knot shape on the outer peripheral surface. The first coil 31 having a plurality of undulating portions 50 is provided, and one undulating portion 30 has a relatively small-diameter small-diameter winding portion 51 and a relatively large-diameter large-diameter winding formed at the rear thereof. A wire portion 52 and a taper winding portion 53 having a diameter gradually reduced from the large diameter winding portion 52 toward the small diameter winding portion 51 in front of the wire portion 52 are provided. By providing the plurality of undulating portions 50, the feeling of roughness due to friction with the living tissue is increased, and the difference in feel between the true cavity and the false cavity becomes clearer than before. [Selection] Figure 2

Description

  The present invention relates to a medical guide wire used for the treatment of a blood vessel blockage or stenosis.

  Conventional medical guide wires of this type are known in which a coil is assembled at the tip of a core wire, or a polymer jacket instead of a coil (see Patent Document 1).

  Japanese Unexamined Patent Publication No. 2011-000469 (see FIGS. 3 and 4)

By the way, in the treatment of a vascular lesion using a medical guidewire, it is required that the medical guidewire pass through the center of a lesion (obstruction or stenosis) called “true lumen”. If a highly complete obstruction lesions calcification deviates lesions inside of the vessel wall (hereinafter, referred to as "false lumen") medical guide wire is sometimes straying. Continuing the procedure in the false lumen may increase the risk of blood vessel perforation and the difficulty of subsequent treatment, so the surgeon feels the fingertip during the operation of the medical guidewire (biological The procedure is performed while determining whether the tip of the medical guide wire has not entered the false cavity (positioned in the true cavity) or not based on the roughness caused by the friction between the tissue and the medical guide wire. ing.

  On the other hand, among the above-described conventional guidewires, the polymer jacket type guidewire is smooth with no irregularities on the surface thereof, so that there is no difference in feel between the true lumen and the false lumen. On the other hand, a coil-type guide wire may have a slight difference in feel due to unevenness of the coil surface, expansion and contraction of the coil, and the like.

  However, even a coil-type guide wire requires skill to discriminate the above-described difference in feel, and further improvement has been demanded.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a medical guide wire that can more easily discriminate the difference in feel transmitted to the fingertip between the true lumen and the false lumen. And

In order to achieve the above object, a medical guide wire according to claim 1 is a medical guide wire comprising a core wire and a coil fixed coaxially to the tip of the core wire, the coil having a bamboo knot-like shape on the outer peripheral surface. A first coil having a plurality of undulating portions, each undulating portion having a relatively small diameter small winding portion, a relatively large diameter winding portion formed behind the large winding portion, and a large diameter A taper winding portion that gradually decreases in diameter from the winding portion toward the small-diameter winding portion in front of the winding portion, and the axial length of the small-diameter winding portion located between adjacent large-diameter winding portions Is characterized in that it is longer than the sum of the axial lengths of the tapered winding portion and the large-diameter winding portion .

  The invention of claim 2 is characterized in that, in the medical guidewire according to claim 1, the outer diameter ratio of the large-diameter winding portion to the small-diameter winding portion is 1.1 or more and less than 1.4. .

  The invention of claim 3 is characterized in that, in the medical guidewire according to claim 1 or 2, the first coil is formed by winding one radiopaque coil wire.

The invention according to claim 4, the medical guide wire according to any one of claims 1 to 3, the outer peripheral surface of the first coil is coated with a tree fat coating, the small-diameter winding portion coil wire It is characterized by sparse winding with a gap in between.

According to a fifth aspect of the present invention, in the medical guidewire according to any one of the first to fourth aspects, the undulation difference of the undulation portion is smaller than the coil wire diameter of the first coil. .

[Invention of Claim 1]
According to the first aspect of the present invention, since the plurality of bamboo knot-like undulations are provided on the outer peripheral surface of the first coil provided at the distal end portion of the medical guide wire, when the medical guide wire is pushed and pulled, Due to the friction between the living tissue and the plurality of undulating portions, the feeling of roughness transmitted to the fingertip becomes larger than before. As a result, the difference in touch transmitted to the fingertip becomes clearer and easier to discriminate between when the distal end portion of the medical guide wire is located in the true lumen and when it is strayed into the false lumen. And when the front-end | tip part of a medical guide wire strays into a false cavity, this can be detected reliably and the situation which raises the difficulty of blood vessel perforation and a subsequent procedure can be avoided. In addition, a taper winding portion is formed between the small-diameter winding portion and the large-diameter winding portion located behind the small-diameter winding portion so that the diameter gradually increases from the small-diameter winding portion toward the large-diameter winding portion. Therefore, it is possible to suppress an increase in resistance when the distal end of the medical guide wire is pushed in a blood vessel or a lesioned part, and to ensure a smooth insertion property.

[Invention of claim 2]
According to the invention of claim 2, when the outer diameter ratio of the large-diameter winding portion to the small-diameter winding portion is 1.1 or more, the case where the distal end portion of the medical guide wire is located in the true lumen; The difference in feel transmitted to the fingertip can be made clearer when the false cavity is lost. Further, by setting the outer diameter ratio to less than 1.4, it is possible to suppress resistance when the distal end portion of the medical guide wire is pushed and pulled in the lesioned portion.

[Invention of claim 3]
According to the invention of claim 3, since the first coil is a single wire coil formed by winding one radiopaque coil wire, the difference in touch transmitted from the tip of the medical guide wire to the fingertip and X By combining the fluoroscopic images, it is possible to more accurately determine the tip position of the medical guide wire.

[Invention of claim 4 ]
According to the present invention, among the outer peripheral surfaces of the first coil, the adjacent large-diameter winding portions have a relatively constricted shape, so when the resin film is formed by the dip coating method, A relatively large amount of coating liquid tends to adhere to the constricted portion. On the other hand, according to the invention of claim 4, the small-diameter winding portion constituting the constricted portion is loosely wound, and a part of the coating liquid permeates into the gap, so that the resin coating film in the constricted portion Increase in thickness can be suppressed. Further, the axial length of the small-diameter wire portion, so is longer than the sum of the axial length of the large-diameter wire portion and the tapered winding portions, penetrate much of the coating solution by the small-diameter winding portion It is possible to suppress the increase in the thickness of the resin film at the constricted portion. As a result, the undulating shape formed on the outer peripheral surface of the first coil can be reliably reflected on the outer peripheral surface of the resin coating.

  Side sectional view of the medical guide wire according to the first embodiment of the present invention.   (A) Side view of coil, (B) Partial enlarged sectional view of first coil   Side sectional view of the distal end portion of the medical guide wire according to the second embodiment

[First Embodiment]
A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2 show the characteristic configuration of the present invention in an emphasized manner for convenience of explanation, and are not shown in actual dimensional ratios.

  As shown in FIG. 1, a medical guide wire 10 (hereinafter simply referred to as “guide wire 10”) has a structure in which a coil 30 is assembled on one end of a core wire 11, and the entire surface thereof is coated with a resin. ing. Specifically, for example, the entire surface of the coil 30 is coated with the hydrophilic resin 20 (corresponding to the “resin coating” of the present invention), and a portion of the core wire 11 exposed from the coil 30 is a fluororesin. 21 (for example, PTFE). The fluorine-based resin is uniformly spray-coated, and the hydrophilic resin 20 is formed by a dip coating method. That is, the front end side of the guide wire 10 is dipped (immersed) in a bathtub filled with a hydrophilic resin coating solution to a predetermined portion (in this embodiment, the position where the coil 30 is completely immersed) and then pulled out. It is formed by drying the coating liquid (hydrophilic resin) adhering to the surface. Hereinafter, the side of the guide wire 10 on which the coil 30 is assembled is referred to as “front end side”, and the opposite side is referred to as “rear end side” or “hand side”. The hydrophilic resin 20 in the present embodiment includes, for example, a main agent (polyethylene oxide, polyvinyl pyrrolidone, etc.) that swells by contact with a body fluid and exhibits lubricity, and an additive that is applied as necessary. Meaning.

  The core wire 11 is made of a metal wire, specifically, a stainless steel wire. The proximal side of the core wire 11 is a main core portion 12 having a relatively large diameter, and the distal end side is a tapered core portion 13 having a tapered shape. The maximum outer diameter of the main core portion 12 is about 0.25 to 0.46 mm (0.010 to 0.018 inch), similar to a conventional general guide wire. On the other hand, the taper core part 13 is gradually reduced in diameter from the main core part 12 toward the tip, and the most recent outer diameter (minimum outer diameter) is, for example, 0.05 to 0.1 mm. The material of the core wire 11 is not limited to stainless steel, and may be a pseudoelastic alloy (nickel titanium alloy), for example. Further, the core wire 11 may have a single wire structure (see FIG. 1) made of a single wire, a twisted wire structure in which a plurality of extra fine wires are twisted, or a dissimilar metal wire (for example, stainless steel on the hand side). It may be a structure in which a wire and a pseudo-elastic alloy wire are joined to the tip side. The core wire 11 can be made into an arbitrary shape and material according to its use (for cardiac coronary artery, peripheral blood vessel, cerebral blood vessel, etc.).

  The coil 30 assembled on the tip end side of the tapered core portion 13 is fixed to the tapered core portion 13 by joining members 14, 15, 16 (for example, brazing material) at both ends and an intermediate portion thereof. In order to avoid damage to the blood vessel wall, the joining member 14 at the front end of the coil 30 is formed in a hemispherical shape, and the joining member 15 at the rear end of the coil 30 gradually expands from the tapered core portion 13 toward the coil 30. It is formed in a substantially conical shape with a diameter.

  The coil 30 is formed by connecting a first coil 31 and a second coil 32 at an intermediate portion in the longitudinal direction. The first coil 31 on the front end side is formed by winding a radiopaque coil wire (for example, platinum-nickel alloy wire), and the second coil 32 on the rear end side is a radiolucent coil wire (for example, stainless steel). Steel wire) is wound. Each of the rear end of the first coil 31 and the front end of the second coil 32 is a loosely wound portion (not shown) having a gap between the strands, and the loosely wound portions are interdigitated with each other. Both the first and second coils 31, 32 are connected. Further, the connecting portion of both the coils 31 and 32 is fixed to the tapered core portion 13 by the joining member 16.

  As shown in FIG. 2 (A), the second coil 32 is formed by winding a coil wire having a predetermined wire diameter into a close winding so as to be in contact with each other, and a tip having a relatively small diameter on the tip side. A side equal diameter winding portion 41 is provided, and a rear end side equal diameter winding portion 42 having a relatively large diameter is provided on the rear end side. Further, the intermediate portion of the second coil 32 is gradually reduced in diameter from the rear end side equal diameter winding portion 42 toward the front end side equal diameter winding portion 41. For example, the outer diameter of the coil wire is 0.05 to 0.06 mm, the outer diameter of the rear end side equal diameter winding portion 42 is 0.30 to 0.32 mm, and the front end side equal diameter winding portion 41. The outer diameter is 0.25 to 0.27 mm. The dimensions and shape of the second coil 32 are not limited to those described above, and may be, for example, a straight coil having a constant outer diameter.

  As shown in FIG. 1, the first coil 31 includes a plurality of bamboo knot-like undulations 50 on its outer peripheral surface. The undulations of these undulations 50 are constant and are provided at equal intervals in the axial direction. As shown in FIG. 2 (A), the undulating portion 50 includes a small-diameter winding portion 51 having a relatively small outer diameter, a large-diameter winding portion 52 having a relatively large outer diameter disposed behind it, and a large winding portion 50. A taper winding portion 53 that gradually decreases in diameter from the diameter winding portion 52 toward the small diameter winding portion 51, and between the large diameter winding portion 52 and the succeeding small diameter winding portion 51, the taper winding A stepped portion 54 whose outer diameter changes sharply compared to the portion 53 is formed. In addition, the number of the raising / lowering parts 50 should just be arbitrary plurality, Preferably, it is 5-15 pieces.

The outer diameter D1 of the small-diameter winding part 51 is, for example, 0.25 to 0.27 mm (same as the tip-side equal-diameter winding part 41 of the second coil 32), and the outer diameter D2 of the large-diameter winding part 52 Is, for example, 0.30 to 0.32 mm (same as the rear end side equal diameter winding portion 42 of the second coil 32). That is, the ratio of the outer diameter D2 of the large diameter winding portion 52 to the outer diameter D1 of the small diameter winding portion 51 (hereinafter referred to as “outer diameter ratio D2 / D1”) is 1.11 to 1.28. . Here, the outer diameters D1 and D2 are not limited to the above dimensions, but the outer diameter ratio D2 / D1 is preferably 1.1 or more and less than 1.4. The reason for this is as follows. That is, when the outer diameter ratio D2 / D1 is less than 1.1, there is almost no difference from the conventional coil-type guide wire, and the feeling (roughness) when the guide wire 10 is pushed and pulled is reduced. This is because it becomes difficult to distinguish between the cavity and the false cavity. On the other hand, if the outer diameter ratio D2 / D1 is set to 1.4 or more, there is a possibility that the resistance when the guide wire 10 is pushed and pulled inside the lesioned part (particularly when the guide wire 10 is pulled back) becomes excessive, thereby increasing the difficulty of the procedure. Because there is.

  In the present embodiment, the undulation difference ΔD (= (D2−D1) / 2) of each undulating portion 50 is smaller than the wire diameter t1 of the coil wire of the first coil 31. Specifically, for example, the coil wire diameter t1 is 0.05 to 0.06 mm, while the undulation difference ΔD is 0.015 to 0.035 mm. Here, when the undulation difference ΔD of the undulating portion 50 is larger than the wire diameter t1 of the coil wire, for example, when the first coil 31 is bent, the large-diameter winding portion 52 is followed by the small-diameter winding portion 51. There is a possibility that the first coil 31 is displaced by riding on the outside, or the hydrophilic resin 20 is damaged by the displacement. On the other hand, if the undulation difference ΔD is made smaller than the wire diameter t1 of the coil wire as in the present embodiment, the large-diameter winding portion 52 outside the small-diameter winding portion 51 when the first coil 31 is curved. Can be prevented, and the above-described problems can be prevented. Note that the configuration of “making the undulation difference ΔD smaller than the coil wire diameter t1” is not essential, but is compatible with the above-described configuration of “the outer diameter ratio D2 / D1 is 1.1 or more and less than 1.4”. To do this, you can do the following: For example, when the outer diameter of the small-diameter winding part 51 is 0.27 mm and the outer diameter ratio D2 / D1 is 1.1 or more and less than 1.4, the undulation difference ΔD is about 0.054 mm at the maximum. Therefore, when the coil wire diameter t1 is set to 0.055 to 0.06 mm, it is possible to achieve both the above-described relationship of the outer diameter ratio D2 / D1.

The axial length of the small-diameter winding part 51 is longer than the total axial length of the large-diameter winding part 52 and the tapered winding part 53. Specifically, for example, the total axial length of the large-diameter winding portion 52 and the tapered winding portion 53 is about half of the axial length (1.4 to 1.6 mm) of the small-diameter winding portion 51. (0.7 to 0.9 mm). The large-diameter winding portion 52 and the tapered winding portion 53 are both closely wound with the coil wires in contact with each other, whereas the small-diameter winding portion 51 is loosely wound with a gap between the coil wires. ing. The size of the gap is sufficiently smaller than the coil wire diameter t1, and is, for example, 0.005 to 0.02 mm in this embodiment (see FIG. 2B). These configurations, the outer peripheral surface to the surface of the hydrophilic resin 20 covering the first coil 31, is to reflect the topography of the first coil 31.

  That is, when the surface of the coil 30 is coated with the hydrophilic resin 20, the coating is usually performed by the dip coating method. However, when the dip coating method is performed on the first coil 31 having the plurality of undulating portions 50 on the outer peripheral surface, the constricted portion between the adjacent large-diameter winding portions 52 (FIG. 2A). The coating liquid of the hydrophilic resin 20 is likely to adhere to a relatively large amount. On the other hand, in the present embodiment, since the small-diameter winding portion 51 located in the constricted portion is loosely wound, a part of the coating liquid penetrates into the gap between the coil strands, and the hydrophilic resin in the constricted portion. An excessive film thickness increase of 20 can be suppressed. Moreover, since the axial direction length of the small diameter winding part 51 is longer than the sum total of the axial direction length of the large diameter winding part 52 and the taper winding part 53, more solution of the hydrophilic resin 20 is used. It is possible to permeate, and the increase in the thickness of the hydrophilic resin 20 at the constricted portion can be more reliably suppressed. Thus, the undulating shape formed on the outer peripheral surface of the first coil 31 can be reliably reflected on the outer peripheral surface of the hydrophilic resin 20 covering the outer peripheral surface.

  Next, the effect of the guide wire 10 of this embodiment is demonstrated. In the treatment of vascular lesions (occlusions and stenosis), stents and balloon catheters are used to expand the lesions and restore blood flow, and to guide the stents and balloon catheters to the lesions The guide wire 10 is inserted into the. Since stents and balloon catheters need to be expanded in the true lumen, it is necessary to always pay attention when operating the guide wire 10 so that the distal end of the guide wire 10 passes through the true lumen without getting into the false lumen. is there. Specifically, it is determined whether or not the tip of the guide wire 10 has entered the false cavity (is located in the true cavity) based on the difference in touch transmitted to the fingertip when the guide wire 10 is pushed and pulled. . However, in the past, skill was required to distinguish the difference in feel.

  On the other hand, according to the guide wire 10 of the present embodiment, since a plurality of bamboo knot-like undulating portions 50 are formed on the outer peripheral surface of the first coil 31, when the guide wire 10 is pushed and pulled, these undulating portions are formed. 50 and a living tissue rub against each other, and a feeling of roughness larger than before is generated. Thereby, the difference in the feeling transmitted to the fingertip between the case where the distal end portion of the guide wire 10 is located in the true lumen and the case where the guide wire 10 is strayed into the false lumen becomes clearer and easier to understand than the conventional guide wire. And even when the front-end | tip part of the guide wire 10 strays into a false cavity, this can be detected reliably and the situation which raises the difficulty of blood vessel perforation and a subsequent procedure can be prevented reliably.

  Further, the guide wire 10 of the present embodiment is a single wire coil in which the first coil 31 provided with the undulating portion 50 is formed by winding one radiopaque coil element wire. The position of the distal end portion of the guide wire 10 can be more accurately determined from the difference in the transmitted feeling and the X-ray fluoroscopic image of the first coil 31. Here, the first coil 31 may connect a plurality of coils having different outer diameters, but in this case, the rigidity changes at the joint of the coils, and the flexibility may be impaired. On the other hand, since the first coil 31 of the present embodiment is a single wire coil formed by winding one coil wire, the flexibility of the coil can be ensured.

  The plurality of undulating portions 50 formed on the outer peripheral surface of the first coil 31 is formed between the small-diameter winding portion 51 and the large-diameter winding portion 52 disposed behind the small-diameter winding portion 51. Since the taper winding portion 53 gradually increases in diameter from 51 to the large-diameter winding portion 52, for example, when the distal end portion of the guide wire 10 is pushed into the lesioned portion, Therefore, it is possible to suppress the resistance when pushing backward and to ensure smooth insertion.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment type bear, the coil wire constituting the first coil 61 is configured differently from the first embodiment. Specifically, as shown in FIG. 3, the coil wire constituting the first coil 61 has a structure in which the wire diameter gradually repeats expansion and contraction, and the coil wire has a constant inner diameter. The plurality of undulating portions 50 are formed on the outer peripheral surface of the first coil 61 by being wound around. Since other configurations are the same as those of the first embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted. This embodiment also has the same effect as the first embodiment.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

(1) In the above embodiment, the coil 30 has a configuration in which the first coil 31 and the second coil 32 are joined at the intermediate portion thereof, but is configured only by the first coil 31 having the plurality of undulating portions 50. May be.

(2) In the above embodiment, the plurality of undulations 50 are formed only in the first coil 31 on the distal end side. However, the plurality of undulations 50 are formed in both the first coil 31 and the second coil 32. Also good.

(3) In the above embodiment, the first coil 31 is composed of a radiopaque coil wire, but may be composed of a radiolucent coil wire. In this case, for example, by including radiopaque fine particles in the resin film covering the outer peripheral surface of the coil 30, the position of the tip of the guide wire 10 can be confirmed with an X-ray fluoroscopic image. .

(4) In the above-described embodiment, the coil wire constituting the coil 30 (the first coil 31 and the second coil 32) has a circular cross section, but may have a non-circular cross section (for example, a substantially rectangular shape).

(5) In the above embodiment, the undulation differences of the plurality of undulations 50 are all the same, but the undulation differences may be different. For example, the undulation difference of the undulating portion 50 may be reduced or increased toward the tip of the guide wire 10.

(6) In the above embodiment, the axial length of the small-diameter winding portion 51 in the first coil 31 is longer than the total axial length of the tapered winding portion 53 and the large-diameter winding portion 52. However, as other embodiments not included in the technical scope of the present invention, for example, depending on the viscosity of the coating liquid, the size of the gap between the coil wires in the small diameter winding portion 51, etc. The axial length of 51 may be equal to or less than the sum of the axial lengths of the tapered winding portion 53 and the large diameter winding portion 52.

10 Medical guide wire 30 Coil 20 Hydrophilic resin (resin coating)
31, 61 1st coil 50 Relief part 51 Small diameter winding part 52 Large diameter winding part 53 Taper winding part D1 Outer diameter of small diameter winding part D2 Outer diameter of large diameter winding part

Claims (5)

In a medical guide wire comprising a core wire and a coil fixed on the tip coaxial of the core wire, the coil has a first coil comprising a plurality of bamboo knot-like undulations on the outer peripheral surface,
Each undulation includes a relatively small-diameter winding portion, a relatively large-diameter winding portion formed away from the winding portion, and the small-diameter winding portion in front of the large-diameter winding portion. With a taper winding portion that gradually decreases in diameter toward
The axial length of the small-diameter winding portion located between the adjacent large-diameter winding portions is longer than the total axial length of the tapered winding portion and the large-diameter winding portion. A medical guide wire characterized by the above.   The medical guide wire according to claim 1, wherein an outer diameter ratio of the large-diameter winding portion to the small-diameter winding portion is 1.1 or more and less than 1.4. The first medical guidewire according to claim 1 or 2 coil is characterized by comprising a single co-yl strand of radiopaque by forming the winding.   The outer periphery of said 1st coil is coat | covered with the resin film, The said small diameter coil | winding part is a loose winding which has a clearance gap between coil strands, The claim in any one of Claim 1 thru | or 3 characterized by the above-mentioned. The medical guidewire as described.   The medical guide wire according to any one of claims 1 to 4, wherein a undulation difference of the undulation portion is smaller than a coil wire diameter of the first coil.

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