JP2021186076A - Medical device - Google Patents

Abstract

To provide a medical device with excellent operability.SOLUTION: A medical device A includes: a long-sized core wire 10; a coil 20 surrounding at least a distal end part of the core wire 10; and an anchor 30 arranged in the outer periphery of the coil on a side of a proximal end of the coil 20 relative to the distal end. A rear end of the anchor 30 is separated from the coil 20.SELECTED DRAWING: Figure 2

Description

The present invention relates to a medical device.

Guide wires are used for intravascular medical procedures (eg, Patent Document 1). The surgeon uses a guide wire to guide a medical device, such as for embolization, to a lesion within a blood vessel.

Japanese Unexamined Patent Publication No. 2005-527332

Medical devices are usually unable to move within a blood vessel to a lesion on their own. Therefore, it becomes necessary to perform an embolization treatment in a blood vessel using two members, a medical device and a guide wire. In that case, it is necessary to perform a plurality of procedures at the time of treatment, and the time required for the treatment becomes longer accordingly. In situations where early treatment is required, such as thrombectomy, there is a need for a device that is easy to operate and can reduce the required time.

The present invention has been completed in consideration of the above circumstances, and an object of the present invention is to provide a medical device having excellent operability.

The present invention is as follows.
(1) A medical device, a long core wire, a coil surrounding at least the distal end of the core wire, and a coil provided on the outer periphery of the coil on the proximal end side of the distal end of the coil. A medical device comprising an anchor, wherein the rear end of the anchor is separated from the coil.
(2) The medical device according to (1), wherein the anchor is formed with a guide surface that is inclined so that the outer diameter becomes smaller toward the distal end side.
(3) In the cross section of the medical device, the cross-sectional area of the strands constituting the coil is smaller on the distal end side from the anchor than on the proximal end side from the anchor (1) or (2). ) The medical device described in.
(4) In the region of the coil on the distal end side from the anchor, a high friction portion having a larger frictional resistance than the region on the proximal end side from the anchor is formed (1) to (3). The medical device according to any one of the above items.
(5) The medical device according to any one of (1) to (4), wherein the coil is formed by spirally winding a plurality of strands.
(6) The medical device according to any one of (1) to (5), wherein the wire constituting the coil is a stranded wire.

According to the medical device of the present invention, the anchor becomes a high resistance portion to the movement of the blood vessel, and the anchor can bite into the lesion portion narrowing the blood vessel. When the medical device is pulled back to the proximal end side with the anchor biting, the anchor can be caught in the lesion and the lesion can be recovered. Since the core wire and coil function as guide wires, medical treatment can be performed by the medical device alone. Therefore, the medical device of the present invention has good operability.

Side view of medical device Partially enlarged cross-sectional view showing the structure on the distal end side of a medical device A perspective view showing the structure of the wire that constitutes the low friction part on the proximal end side of the coil of the medical device. A perspective view showing the structure of the wire that constitutes the high friction part on the distal end side of the coil of the medical device. Partially enlarged side view showing the state where the coil is not deformed on the distal end side of the medical device Partially enlarged side view showing a state in which a part of the coil is enlarged and deformed on the distal end side of the medical device.

A medical device A that embodies the present invention will be described with reference to the drawings. In the following description, the anterior end and the distal end are used interchangeably, and the posterior end and the proximal end are used interchangeably. The length direction, the axial direction, and the front-back direction of the medical device A are used interchangeably. Regarding the front-back direction, the left side in FIGS. 1, 2 and 5 to 7 is defined as the front.

The medical device A is a device that exerts a function as a guide wire and a function of performing medical treatment such as thrombus removal and recovery, and as shown in FIGS. 1 and 2, a long core wire 10 and a long core wire 10 are exhibited. A coil 20 surrounding the core wire 10 and an anchor 30 provided on the outer periphery of the coil 20 are provided. The anchor 30 is arranged on the proximal end side of the coil 20 with respect to the distal end, and protrudes from the outer periphery of the coil 20 in the radial direction of the core wire 10. Further, the medical device A includes a tip tip 12 attached to the tip of the core wire 10 and a marker 15 arranged inside the coil 20.

The core wire 10 has a length corresponding to the total length of the medical device A and is a bendable metal member. The core wire 10 has a substantially circular cross-sectional shape and an outer diameter that is maximum at the proximal end and minimum at the distal end of the medical device A. The rear end of the core wire 10 is an operation unit 11.

A circular tip 12 is fixed to the distal end of the core wire 10 so as to be rotatable concentrically with the core wire 10 and integrally with the core wire 10. The front surface of the tip tip 12 is spherical, and the rear surface is a fixing surface 13 perpendicular to the axis of the core wire 10. A flange-shaped fixing portion 14 forming a circular shape concentric with the core wire 10 is formed between the distal end and the proximal end of the outer circumference of the core wire 10. A marker 15 made of a material that does not transmit X-rays, such as tungsten, is fixed to the position of the core wire 10 on the proximal end side of the tip tip 12.

The coil 20 is called a multi-row coil in which a plurality of (two in the present embodiment) strands 21 are spirally wound, and has a cylindrical shape as a whole. The outer diameter of the coil 20 is substantially the same as the outer diameter of the tip tip 12. The inner diameter of the coil 20 is larger than the outer diameter on the distal end side of the core wire 10. Of the strands 21 constituting the coil 20, the tip portion particularly contains a material that does not transmit X-rays.

FIGS. 3 and 4 show an example of the configuration of the strands. As shown in the figure, the strand 21 may be a stranded wire obtained by twisting a plurality of wires 22 having the same outer diameter and the same material. In FIGS. 3 and 4, seven strands 21 are twisted together to form a stranded wire. On the outer peripheral surface of the wire 21, six spiral protrusions 23 and six spiral grooves 24 are formed. The cross-sectional shape of the strand 21 is substantially circular. Specifically, a plurality of irregularities corresponding to the groove portion 24 and the protrusion portion 23 are formed on the outer periphery of the cross section of the strand 21. In FIGS. 1 and 2, the strand 21 is drawn as a single core wire for convenience.

The coil 20 concentrically surrounds the distal end region of the core wire 10 and the marker 15. The distal end of the coil 20 is fixed to the fixing surface 13 of the tip tip 12 by welding or the like. The distal end of the coil 20 fixed via the tip tip 12 and the distal end of the core wire 10 are integrally movable in the axial direction and integrally rotatable in the circumferential direction. The total length of the coil 20 is shorter than the total length of the core wire 10, and is the same as the length from the tip tip 12 to the fixing portion 14. The rear end of the coil 20 is fixed to the fixing portion 14 of the core wire 10 by welding or the like, and the rear end of the coil 20 is rotatable integrally with the core wire 10.

The anchor 30 is made of synthetic resin and is molded in a state of being integrated with the coil 20 by insert molding or the like. The position where the anchor 30 and the coil 20 are integrated is on the proximal end side of the distal end (tip tip 12) of the coil 20 and on the distal end side of the fixing portion 14 and the marker 15. The length of the anchor 30 in the axial direction is shorter than the distance from the front end of the tip tip 12 to the front end of the anchor 30.

The anchor 30 has a cylindrical shape whose cross-sectional shape is concentric with the core wire 10 and the coil 20. The outer diameter of the anchor 30 is larger than that of the coil 20. The anchor 30 is formed with a protruding portion 31 protruding outward in the radial direction from the outer circumference of the coil 20. The inner diameter of the central hole 32 of the anchor 30 is larger than the outer diameter of the core wire 10 and smaller than the inner diameter of the coil 20. The coil 20 penetrates the anchor 30 in the axial direction. The core wire 10 is inserted into the center hole 32 so that the anchor 30 can be displaced relative to the core wire 10 in the axial direction and can rotate relatively in the circumferential direction.

The outer peripheral surface of the protrusion 31 is roughened to form fine irregularities (not shown) and processed to form grooves in the axial direction. By this processing, the outer peripheral surface of the anchor 30 functions as a high resistance portion 33 that generates a large resistance when relatively rotated with respect to the lesion portion (not shown) in the blood vessel. In the region on the distal end side of the outer peripheral surface of the protrusion 31, a tapered guide surface 34 whose outer diameter dimension gradually decreases toward the distal end is formed.

The rear end (rear end portion on the proximal end side) facing the proximal end side of the outer surface of the anchor 30 is separated from the coil 20. As shown in FIG. 2, an overhang-shaped recess 35 is formed at the rear end. The recess 35 has a shape in which the inner peripheral surface of the anchor 30 is undercut so that the inner diameter of the anchor 30 gradually decreases toward the distal end side. By forming the recess 35 in the anchor 30, a ring-shaped biting portion 36 projecting rearward is formed on the outer periphery of the rear end portion of the anchor 30 (protruding portion 31).

FIG. 3 is a perspective view showing the structure of the wire 21 constituting the low friction portion 20L on the proximal end side of the coil 20 on the proximal end side of the anchor 30, and FIG. 4 is a height on the distal end side of the anchor 30. It is a perspective view which shows the structure of the wire 21 which constitutes the friction part 20H. The region of the coil 20 exposed from the front end to the distal end side of the anchor 30 functions as the high friction portion 20H. When the high friction portion 20H comes into contact with the lesion portion, the frictional resistance generated between the high friction portion 20H and the lesion portion is the low friction portion 20L which is the region proximal to the anchor 30 in the coil 20. Greater than the frictional resistance that occurs between the lesion and the lesion. As shown in FIG. 3, in the low friction portion 20L, the wire rods 22 constituting the strand 21 are in close contact with each other. On the other hand, in the high friction portion 20H, as shown in FIG. 4, the outer diameter dimension of the seven wire rods 22 constituting the strand 21 is reduced by electrolytic polishing.

As shown in FIG. 4, when the wire rod 22 is thinned, a clearance 37 is generated between the wire rods 22, and the groove portion 24 on the surface of the wire rod 21 becomes deeper and larger than the low friction portion 20L, and is relatively a protrusion. There is a possibility that the protrusion amount of 23 will be larger than that of the low friction portion 20L. As the amount of protrusion of the protrusion 23 increases, as will be described later, the protrusion 23 can bite deeper into the lesion. Therefore, in the high friction portion 20H, the resistance between the wire 21 and the lesion is low in the friction portion 20L. Will be larger than. Further, when the outer diameter dimension of the wire rod 22 is reduced, the cross-sectional area of the wire 21 (total cross-sectional area of the seven wire rods 22) is also reduced, so that the bending rigidity of the high friction portion 20H is the bending rigidity of the low friction portion 20L. Is lower than. As a result, the coil 20 of the high friction portion 20H on the distal end side of the anchor 30 is more easily deformed than the low friction portion 20L.

Next, an example of medical treatment using the medical device A will be described. The technician inserts the medical device A into the blood vessel while holding the operation unit 11 of the core wire 10 with one hand. Since the medical device A in which the core wire 10 is surrounded by the coil 20 functions as a guide wire, the medical device A can be inserted into the blood vessel without using a separate guide wire. The technician inserts the medical device A while grasping the positions of the markers 15 and the tips of the coils 20 displayed on the fluoroscopic monitor and confirming the positions of the distal end of the medical device A and the anchor 30. Proceed.

When the high friction portion 20H of the coil 20 passes through the lesion portion such as a thrombus and the anchor 30 enters the lesion portion, the insertion of the medical device A is stopped. Since the front surface of the tip tip 12 is spherical, the coil 20 easily penetrates the lesion. Further, although the outer diameter of the anchor 30 is larger than that of the coil 20, since the tapered guide surface 34 is formed on the outer periphery of the front end portion of the anchor 30, the anchor 30 easily enters the lesion portion.

With the anchor 30 in the lesion, the operation unit 11 is pulled toward the proximal end side while turning the proximal end side of the coil 20. Since the distal end of the coil 20 is integrated with the core wire 10 via the tip tip 12, and the proximal end of the coil 20 is integrated with the core wire 10 via the fixing portion 14, the rotational force of the core wire 10 is integrated with the coil. The rotational force transmitted to the coil 20 and applied to the coil 20 is transmitted to the anchor 30 integrated with the coil 20.

However, since a large resistance is generated between the high resistance portion 33 of the anchor 30 and the lesion portion, the anchor 30 is difficult to rotate. Therefore, in the low friction portion 20L on the proximal end side of the coil 20 with respect to the anchor 30, the distal end does not rotate and the proximal end rotates integrally with the core wire 10. Therefore, distortion occurs in the low friction portion 20L. Even in the high friction portion 20H, the proximity portion of the anchor 30 is difficult to rotate, while the distal portion rotates integrally with the core wire 10 via the tip tip 12, so that the high friction portion 20H is also distorted. Since the cross-sectional area of the wire 21 of the coil 20 is smaller than that of the low friction portion 20L and the rigidity of the high friction portion 20H is lower, the high friction portion 20H is more easily deformed than the low friction portion 20L, and the high friction portion 20H is a low friction portion. It deforms before 20L. Therefore, for example, a part of the high friction portion 20H can be expanded in diameter so as to be in the state shown in FIGS. 5 to 6.

After the high friction portion 20H is expanded and deformed from the anchor 30, the core wire 10 is pulled and moved toward the proximal end side without rotating. Then, the biting portion 36 of the anchor 30 bites into the lesion portion and peels the lesion portion from the inner wall of the blood vessel, and the peeled lesion portion can be recovered. Even if the anchor 30 leaves a part of the lesion, the high friction portion 20H having a diameter larger than that of the anchor 30 may also be entangled with the left-behind lesion and peeled off from the inner wall of the blood vessel.

Since the high friction portion 20H is a multi-row coil 20 composed of a plurality of strands 21, when the high friction portion 20H is expanded and deformed, a gap 38 is generated between the strands 21 as shown in FIG. 21 penetrates deeply into the lesion, and the lesion enters the gap 38 between the strands 21. Further, since there is a clearance 37 (see FIG. 4) between the wires 22 of the high friction portion 20H, the wire 22 bites deeply into the lesion and the lesion enters the clearance 37 between the wires 22.

As described above, the medical device A can be inserted into the lesion without using a dedicated guide wire separately. In addition to that, if the operation portion 11 is rotated and pulled, the lesion portion in the blood vessel can be peeled off by the anchor 30, and in some cases, it is entangled by the wire 21 and the wire 22 of the coil 20. It can be taken and collected.

The medical device A includes a core wire 10, a coil 20 that surrounds at least the distal end of the core wire 10, and an anchor 30. The anchor 30 is provided at a position on the coil 20 closer to the proximal end than the distal end. The anchor 30 has a protrusion 31 protruding from the outer circumference of the coil 20. According to this medical device A, the recess 35 separated from the coil 20 can be made to bite into the lesion, the medical device A can be pulled back to the proximal end side, and the lesion can be recovered by the anchor 30. Become.

In the medical device A, since the core wire 10 and the coil 20 function as guide wires, the guide wire is not required when performing a medical procedure. Therefore, the medical device A has good operability.

The present invention is not limited to the above-mentioned forms, and for example, the following forms are also included in the technical scope of the present invention. In the above form, the anchor is made of synthetic resin, but the material is not particularly limited, and for example, it may be made of metal, and the molding method does not have to be insert molding. Further, in the above-mentioned form, the guide surface is formed on the anchor, but the guide surface may not be provided.

In the above embodiment, the lesion can be recovered by a high friction portion of the coil on the distal end side of the anchor. However, it is not always necessary to provide a high friction portion.

Further, the high friction portion may be in a form in which the surface of the wire constituting the coil is roughened or in a form in which the surface of the wire is made uneven. In order to roughen the surface of the wire or increase the unevenness of the surface, physically polish the surface of the wire, use a wire with a rectangular cross section, and twist multiple types of wires with different outer diameters. A method such as using the combined stranded wire as a wire can be considered. Further, in the high friction portion, the high friction portion of the coil is formed by reducing the diameter of the wire material constituting the stranded wire by electrolytic polishing, but the high friction portion is not limited to the method of electrolytic polishing the stranded wire. , The surface of the wire constituting the coil may be roughened. In order to roughen the surface of the wire, the surface of the wire is physically polished, a wire with a rectangular cross section is used, and a stranded wire obtained by twisting multiple types of wires having different outer diameters is used as the wire. Such a method can be considered.

The outer diameter of the wire that constitutes the coil is smaller in the region on the distal end side than the anchor than in the region on the proximal end side of the anchor, but the outer diameter dimension of the wire is smaller than that of the anchor. The area on the proximal end side and the area on the distal end side of the anchor may have the same dimensions, and the area on the distal end side of the anchor is compared with the area on the proximal end side of the anchor. May be larger.

The coil is a multi-row coil formed by spirally winding two strands, but the coil may be a multi-row coil in which three or more strands are spirally wound. It may be a single-row coil in which a wire is spirally wound. The strand is a stranded wire obtained by twisting only wires having the same outer diameter, but the strand may be a stranded wire obtained by twisting a plurality of types of wires having different outer diameters. In the above embodiment, the wire constituting the coil is composed of a stranded wire, but the wire may be a single core wire. The cross-sectional shape of the wire made of a single core wire may be circular or non-circular such as oval, elliptical, and rectangular.

Even if an inner layer coil having a diameter smaller than that of the coil and surrounding the core wire is provided between the tip tip and the front surface of the anchor, the distal end and the proximal end of the inner layer coil are fixed to the tip tip and the anchor, respectively. good.

The distal end and tip of the coil and the proximal end and fixation of the coil do not need to be fixed by welding, and can be fixed by soldering, for example.

A Medical device 10 Core wire 11 Operation part 12 Tip tip 13 Fixed surface 20 Coil 20H High friction part 20L Low friction part 21 Wire 22 Wire rod 23 Protrusion part 24 Groove part 30 Anchor 31 Protrusion part 32 Center hole 33 High resistance part 34 Induction surface 35 Recessed part 36 Biting part 37 Clearance 38 Gap

Claims (6)

It ’s a medical device,
With a long core wire,
With a coil surrounding at least the distal end of the core wire,
An anchor provided on the outer periphery of the coil on the side proximal to the distal end of the coil.
The rear end of the anchor is a medical device that is separated from the coil. The medical device according to claim 1, wherein the anchor is formed with a guide surface that is inclined so that the outer diameter becomes smaller toward the distal end side. The first or second aspect of the cross section of the medical device, wherein the cross-sectional area of the strands constituting the coil is smaller on the distal end side from the anchor than on the proximal end side from the anchor. Medical device. 3. The medical device described in. The medical device according to any one of claims 1 to 4, wherein the coil is formed by spirally winding a plurality of strands. The medical device according to any one of claims 1 to 5, wherein the strands constituting the coil are stranded wires.

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