JP2005342470A - Medical guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical guide wire easily deforming the shape of a guide wire distal end part, namely, easily deforming the shape of the guide wire distal end part according to the shape and the direction of a branch blood vessel at a proximal end side and having superior operability. <P>SOLUTION: This medical guide wire comprises an outer cylinder having the distal end curved at an arbitrary curvature and an inner core freely inserted into its inside. The inner core is inserted into the adjacency of the distal end of the outer cylinder to gradually reduce the radius of curvature of the distal end of the cylinder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical guide wire that is inserted into a blood vessel in advance as a guide when a catheter or the like is inserted into the blood vessel, for example.

  As a typical example of a conventional medical guidewire, there is a guidewire described in Patent Document 1 (see particularly FIG. 7). In such a guide wire, at least the distal end portion is wound with a thin metal wire in a spiral coil shape, and an outer cylinder made to have flexibility, and the most distal portion of the inner core is fixed to the outer cylinder. It is comprised from the said inner core. The outer surface of the inner core is slidable with the inner surface of the outer cylinder except for the most advanced portion.

In the guide wire configured as described above, the first portion of the outer cylinder is pressed with one hand, and the second portion on the hand side (the direction opposite to the insertion direction) is pressed with the other hand. By pulling to the side, the outer coil is stretched between the first location and the second location. At this time, since the first part is pressed by one hand, the coil on the tip side does not extend from the first part. However, since the inner core is movable in the axial direction of the outer cylinder, it is pulled toward the hand side. At this time, since the distal end of the inner core is fixed to the distal end of the outer cylinder, the distal end of the outer cylinder is lifted by the tensile force of the inner core, and the distal end portion of the guide wire gradually changes from an I shape to a J shape. Deform. From such a principle, the shape of the tip portion of the guide wire can be freely deformed by adjusting the degree of tension of the inner core.
JP 2003-111849 A

  In such a type of medical guide wire, it is necessary to apply a strong force to the outer cylinder, so that the operability is poor and the guide wire is inserted into a branch blood vessel that branches from the main blood vessel at an acute angle. It was necessary to insert it carefully and timely so as not to damage the inner wall of the blood vessel. For this reason, a guide wire that can be safely and easily inserted into a blood vessel that branches at an obtuse angle, even when handled by a person who is not so familiar with the insertion procedure of the guide wire, for a blood vessel that branches at an obtuse angle, that is, complicated A medical guide wire excellent in operability is desired.

  Therefore, the main object of the present invention is to easily control the shape of the tip portion of the guide wire, i.e., the shape and orientation of the guide wire tip portion corresponding to the direction of the branching blood vessel and the complicated route of the blood vessel at hand. An object of the present invention is to provide a medical guide wire that can be changed and has excellent operability.

  Another object of the present invention is to provide a medical guide wire that has a simple structure and can be manufactured at low cost.

  In order to achieve the above main object, the medical guide wire of the present invention is preferably composed of an outer cylinder whose tip portion is bent with an arbitrary curvature, and an inner core that can be inserted and withdrawn therein. By inserting the core to the vicinity of the tip of the outer cylinder, the curvature of the outer cylinder tip is gradually reduced. The outer cylinder and an inner core that can be inserted into the outer cylinder can be configured such that the curvature of the outer cylinder tip portion gradually increases as the inner core is inserted to the vicinity of the outer cylinder tip. .

(1) According to one most preferable aspect, the medical guide wire according to the present invention is an elongated cylindrical body in which a thin wire is wound in a spiral coil shape, and a distal end portion is bent with an arbitrary curvature. A flexible outer cylinder that can be inserted into the outer cylinder, the inner surface of the outer cylinder and the outer surface of the inner core being slidable over the entire inner core, and the inner core being the outer cylinder. It is configured such that the curvature of the outer cylinder tip portion gradually decreases as it is inserted into the tip portion.

  In such a medical guide wire having the configuration described in (1) above, the distal end portion of the guide wire is rounded into a J shape or a circular shape, or stretched almost straight by pulling out and inserting the inner core. It is very easy to do.

(2) In the medical guide wire described in (1) above, it is preferable that the curvature of the distal end portion of the outer cylinder is larger than the proximal side in the insertion direction at the distal end in the insertion direction.

  By making the curvature of the distal end of the outer cylinder extremely large, damage to the inner wall of the blood vessel can be prevented even if a person who is not familiar with the insertion procedure performs an erroneous operation.

(3) In the medical guide wire having the configuration described in the above (1) or (2), the cross-sectional shape of the thin wire constituting the outer cylinder is a substantially perfect circle, and further, the outermost of the inner core. The tip is preferably hemispherical, and the curvature of the hemisphere is preferably smaller than the curvature of the thin line.

  With the configuration as described in (3) above, the resistance that the tip of the inner core receives due to the unevenness formed on the adjacent portion of the coil forming the inner wall of the outer cylinder is reduced, and the inner core is smoothly turned to the outer cylinder tip. Can be inserted.

  According to the medical guidewire of the present invention, it is possible to freely change the angular direction of the distal end portion of the guidewire according to the branching angle of the branch blood vessel simply by adjusting the degree of insertion of the inner core into the outer tube. Even if the guide wire is operated incorrectly, the guide wire can be easily inserted into a blood vessel having a complicated shape without damaging the inner wall of the blood vessel.

  Initially, the structure of the medical guide wire which concerns on one Example of this invention is demonstrated using FIG. Throughout the drawings, the same reference numerals indicate functionally substantially the same configuration. FIG. 1A schematically shows the structure of an outer cylinder used in the medical guide wire according to the present invention, and FIG. 1B schematically shows the structure of its inner core. Moreover, FIG.1 (c) has shown the enlarged view of inner-center front-end | tip part vicinity shown by FIG.1 (b).

  An outer tube 10 of a guide wire according to one embodiment of the present invention shown in FIG. 1A is formed by winding a thin metal wire 11 in a helical coil shape with a dense pitch. In the outer cylinder of FIG. 1 (a), the tip portion 10a has a so-called J-shape, and the other portion, that is, the proximal portion is formed in a substantially linear shape. The end portion in the insertion direction of the tip portion 10a is sealed by appropriate means such as laser melting and welding so that the inner core does not protrude from the outer tube tip when an inner core to be described later is inserted. The shape of the outer cylinder tip portion 10a is not limited to the J shape, and may be an O shape or a spiral shape. The curvature of the curved portion of the tip portion 10a can be arbitrarily determined. Further, the tip portion 10a may be entirely or partially straight. The shape of the tip portion can be freely set according to the structure of the blood vessel to be applied. In order to process the distal end portion 10a into a desired shape, a spiral coil having a linear shape as a whole is formed by a thin metal wire, and then forcibly bent into a desired shape and left as it is depending on the metal material. By performing the heat treatment at a predetermined temperature for this time, the shape of the outer cylinder 10 can be stably held in a desired shape. Since this heat treatment process can be performed by a known technique, a detailed description thereof is omitted here.

  FIG. 1B schematically shows the configuration of the inner core 20 that can be inserted into or removed from the outer cylinder 10 described above. The inner core 20 according to the first embodiment is made of a metal having higher rigidity than the outer cylinder 10. However, it can be made of the same metal as the outer cylinder. In this case, it is necessary to increase the rigidity of the outer cylinder by changing the heat treatment conditions. The material of the inner core 20 is not limited to metal, and may be a synthetic resin as long as sufficient strength can be secured. The outer diameter of the inner core 20 only needs to be smaller than the inner diameter of the outer cylinder 10 in the thickest portion of the portions inserted into the outer cylinder, and the value can be arbitrarily set. Further, the inner core 20 can be smoothly inserted into the distal end portion 10a of the outer cylinder 10, the flexibility of the distal end portion of the guide wire when the inner core is fully inserted is maintained, and the strength at the side of operating the guide wire is increased. In order to raise, it is desirable to make the front-end | tip part 20a of the inner core 20 relatively thin with respect to the other part (hand side part) 20b. In this embodiment, the diameter of the inner core gradually decreases toward the distal end direction of the inner core, but the same diameter may be used up to the vicinity of the distal end portion 20a.

  As can be understood from the enlarged view of the tip portion 20a of the inner core 20 shown in FIG. 1 (c), the end portion of the tip portion 20a in the insertion direction is a hemisphere having a radius r. It is desirable that the curvature of the hemispherical outer circumference circle is smaller than the curvature of the thin metal wire 11 forming the outer cylinder 10. With this configuration, the inner core can be smoothly inserted into the distal end portion of the outer cylinder without the resistance of the distal end of the inner core due to the unevenness of the portion adjacent to the coil forming the inner wall of the outer cylinder. .

  FIGS. 2A to 2C show a schematic shape of the guide wire at each operation stage of the guide wire according to the first embodiment. Here, Fig.2 (a) is also the figure which has shown typically the basic composition of one Example of the guide wire which concerns on this invention. Next, the operation of the guide wire according to the present embodiment will be described with reference to these drawings.

  FIG. 2A shows an initial state in which no force is applied from the inner core to the outer cylinder. In other words, in this embodiment, the outer cylinder 10 has a J-shape when it is manufactured. FIG. 2B shows a state in which the inner core 20 is inserted up to the entrance portion 10aa of the distal end portion 10a of the outer cylinder 10, lightly contacts the inner wall of the outer cylinder 10, and stress in the insertion direction is applied to the inner wall of the outer cylinder. ing. At this stage, the insertion stress that is still applied from the inner core 20 to the inner wall of the outer cylinder 10 is applied to the entrance portion 10aa of the distal end portion 10a of the outer cylinder 10, so that the stress applied to the distal end portion 10ab is much greater. Absent. Therefore, the outer cylinder slightly decreases its curvature and deforms to a shape close to an L shape.

  Further, when the inner core 20 is inserted to the distal end portion 10ab of the outer tube distal end portion 10a, the outer tube is deformed into an approximately I shape as shown in FIG. That is, in the guide wire of this embodiment, the insertion stress applied from the inner core 20 to the outer cylinder by gradually inserting the inner core 20 in the axial direction becomes the bending stress of the outer cylinder applied in advance. Defeats and raises the outer cylinder front-end | tip part 10a. That is, according to the degree of insertion of the inner core 20, the curvature of the outer cylinder tip portion 10 a gradually decreases, and finally the outer shape of the outer cylinder 10 is substantially similar to the outer shape of the inner core 20.

    FIG. 3A to FIG. 3C schematically show the operation when the guide wire according to the present invention is inserted into the branch blood vessel. In FIG. 3A, reference numeral 10 (10a, 10b) indicates a guide wire, 100 indicates a main blood vessel, and 101 indicates a branch blood vessel. As shown in this figure, the guide wire inserted into the main blood vessel is directed in the direction of the blood vessel branched at an obtuse angle α at the branch portion of the main blood vessel. At this time, in the conventional technique, when a guide wire is inserted into such an obtuse branched blood vessel, the guide wire having a bent distal end portion is not easily deformed in the main blood vessel. Depending on the shape and direction, it was impossible to insert. Also, even if it is a branch vessel that has an insertable shape and direction, if a person who has little experience in inserting a guide wire handles it, take care to avoid damaging the inner wall of the branch vessel. Had to do. Furthermore, in some cases, the guide wire with the first shape used cannot be inserted into the branch vessel, and it is necessary to re-insert a guide wire with a different shape at the tip of the guide wire, which is very troublesome. there were.

  As described above, the guide wire according to the present invention is configured such that the curvature of the distal end portion of the guide wire can be freely changed by inserting or withdrawing the inner core even in the main blood vessel. 3A, FIG. 3B, and FIG. 3C are sequentially shown for a thin branch blood vessel and a branch blood vessel having a complicated shape and branch direction that have been difficult to insert. Can be inserted into the branch vessel by the procedure described above.

  As described above, when a guide wire is inserted into a branched blood vessel, the guide wire is not damaged in the inner wall of the blood vessel in the conventional guide wire in which the tip of the guide wire is bent in a J shape. Was very difficult to insert into the branch vessel. However, in the medical guide wire of the present invention, in the state where the inner core is pulled out from the distal end portion of the outer cylinder, the inner core does not exist in the outer cylinder, so that the distal end portion of the guide wire is very flexible and the inner wall of the blood vessel Can be easily inserted without damage.

  Also, if there is a locking tool that can fix the positional relationship between the outer cylinder and the inner core when changing the insertion direction of the guide wire, the operator can concentrate on changing the insertion direction, making it safer and easier. The operation can be performed. As such a fixing means, a base, a first locking means provided at one end of the base, and a second locking means provided at the other end of the base are provided, and the first and second It is preferable to use such a locking tool that the locking means can individually clamp the outer cylinder or the inner core and can clamp both at the same time.

  In the above description, it has been described that the cross-sectional shape of the thin wire forming the helical coil of the outer cylinder is substantially a perfect circle, but this cross-sectional shape is the coil adjacent to the coil ( Any structure can be used as long as the direction of stress applied to the n-th coil and the (n + 1) -th coil) can be easily changed when n is an integer. That is, it is only necessary that adjacent coils can be easily shifted and the shape of the outer cylinder can be smoothly deformed. In addition, although it has been described that the outer cylinder is a metal, it can naturally be made of a synthetic resin. In this case, it is preferable to mix a metal in the resin so that recognition by radiation is easy.

  Moreover, as a material of the outer cylinder and inner core of the medical guide wire according to the present invention, a shape memory alloy made of Ni (nickel) -Ti (titanium) is desirable from the viewpoint of operability and recoverability against torsion. However, a general alloy or synthetic resin may be used as long as the material satisfies the above conditions. In any case, the outer tube and the inner core of the medical guide wire according to the present invention may be applied with the conventional material and shape as they are as a single structure, respectively. It is self-evident to see. Various shapes of the conventional inner core are shown in FIGS. Any of these shapes can be applied to the present invention. By using an inner core having a shape as shown in FIG. 4 (e), when a straight outer cylinder is used, the curvature of the outer cylinder tip is changed according to the degree of insertion of the inner core into the outer cylinder. It can be made to increase gradually. FIG. 4 shows an example of the shape of the inner core, and is not limited to these illustrated shapes.

  The present invention is particularly effective for inserting a catheter into a complex-shaped blood vessel, and greatly contributes to the development of medical technology.

FIG. 1 is a schematic view showing a structure of an outer tube and an inner core of a medical guide wire according to a first embodiment of the present invention.

FIG. 2 is a schematic view for explaining the operation of the medical guide wire according to the first embodiment of the present invention.

FIG. 3 is an operation explanatory view showing a state in which the medical guide wire of the present invention is inserted into a blood vessel.

  FIG. 4 is a diagram showing examples of various shapes of the inner core used in the medical guide wire of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Medical guide wire 10 Outer cylinder 10a of guide wire Tip part 10b of outer cylinder Base part (hand side part) of outer cylinder
11 Spiral coil 20 constituting outer cylinder Guide wire inner core 20a Inner core tip portion 20b Inner core base portion (hand side portion)

Claims (7)

  A thin and thin cylindrical body wound in a spiral coil shape, and a flexible outer cylinder whose tip is bent with an arbitrary curvature, and the outer cylinder can be inserted into the outer cylinder. A medical core characterized in that the curvature of the outer cylinder tip portion gradually decreases as the inner core is inserted into the outer cylinder tip portion. Guide wire.   2. The medical guide wire according to claim 1, wherein the curvature of the distal end portion of the outer cylinder increases toward the distal end in the insertion direction. 3.   The medical guide wire according to claim 1 or 2, wherein the cross-sectional shape of the thin wire constituting the outer cylinder is a substantially perfect circle, and the most distal end portion of the inner core is substantially hemispherical. A medical guide wire, wherein the curvature of the hemisphere is smaller than the curvature of the thin wire. A flexible outer cylinder that is an elongated cylindrical body, and an inner core that can be freely inserted into and extracted from the outer cylinder, and as the inner core is inserted into the outer cylinder distal end portion, the outer cylinder distal end portion A guide wire for medical use, characterized in that the curvature of is changed.   5. The medical guide wire according to claim 4, wherein the distal end portion of the outer cylinder is bent in a substantially J shape.   6. The medical guide wire according to claim 5, wherein the curvature of the distal end portion of the outer cylinder increases toward the distal end in the insertion direction.   The medical guide wire according to claim 4 or 5, wherein the cross-sectional shape of the thin wire constituting the outer cylinder is a substantially perfect circle, and the most distal end portion of the inner core is substantially hemispherical. A medical guide wire, wherein the curvature of the hemisphere is smaller than the curvature of the thin wire.

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