JP5580802B2 - Medical guidewire - Google Patents

Description

  The present invention relates to a medical guide wire used for introducing a medical device such as a catheter or an introduce circuit used for treatment or examination to a desired site in a blood vessel.

  The medical guide wire is used when a medical device such as a catheter or an introduce circuit is introduced and placed in a blood vessel when performing blood vessel diagnosis and treatment percutaneously. Conventionally, femorals (thighs) have been the mainstream when introducing medical devices such as catheters into blood vessels. Recently, brachials (upper arms) and especially radials (wrists) are used to reduce the burden on patients. There is a need for a medical guide wire having, for example, a J-shape at the tip, which can be safely used in an arm blood vessel that often has branches or meanders, and is excellent in operability. .

  Conventionally, when a medical guide wire having a J shape at the tip is inserted into an introduction needle or a catheter, an auxiliary device (inserter) for facilitating the insertion has been used. When the radius of curvature of the portion is small, it is complicated to remove the medical guide wire from the blood vessel and insert it into the inserter again when exchanging the catheter.

  In order to solve the above-mentioned problems, the wire formed on the introduction needle, the catheter, the sheath, etc. by setting the angle formed by the direction extension line of the tip straight line portion and the wire base line with respect to the tip shape of the medical guide wire to 40 to 70 °. There exists what was disclosed by patent document 1 as what made the auxiliary | assistant instrument at the time of insertion unnecessary.

JP 2004-181184 A

  In the case of a medical guide wire that has been used in the past and has a J-shaped tip, the tip-shaped portion has a uniform hardness, or the stiffness (hardness) on the proximal side of the J-shaped portion is not good. Because it is sufficient, the operability when inserting into an introduction needle, catheter, or sheath was often poor.

  Also, the operation of removing the medical guide wire from the body during diagnosis or treatment, such as exchanging the catheter, and inserting it again is a frequently performed operation. In that case, with the conventional J-type medical guide wire, Insertion aids such as inserters must be used, and the operability at that time is often extremely lowered, which has forced doctors to spend unnecessary work time and stress.

  Furthermore, even in a medical guide wire that does not require an insertion assisting instrument such as an inserter, as shown in Patent Document 1, a catheter is maintained while frequently holding and holding a portion relatively close to the distal end in the initial stage of insertion. In some cases, it is necessary to perform an operation of feeding the material into the area, and the operability cannot be said to be satisfactory.

  When the above-described conventional J-type medical guidewire is introduced from the wrist (radial), it does not return to its original shape unless there is a trigger such as a blood vessel bifurcation, and the distal end scratches or hits the blood vessel wall. Therefore, there is a high possibility of damaging the blood vessel wall. Furthermore, when the distal end of the medical guide wire is caught on the blood vessel branching portion, the possibility of damaging the blood vessel wall is further increased due to the difficulty of deformation of the distal end shape portion.

  In order to solve the above-described problems, the present inventors have conducted intensive studies, and in a medical guide wire having a curved shape at the tip, such as a J shape, the operability when inserted into an introduction needle, a catheter, or a sheath Ascertained that the factor that determines the behavior of the distal end of a medical guide wire in a lumen such as a blood vessel or a catheter is the rate of increase of the wire diameter per unit length in the taper portion of the core wire, and completed the present invention. . In addition, an element that determines the behavior of the distal end portion of the medical guide wire in the lumen is a balance between the wire diameter increase rate and the hardness of the distal shape portion (for example, the distal diameter of the core wire and the core wire with respect to the distal shape). The position of the taper starting portion) was determined, and the present invention was completed. Compared to a conventional medical guide wire with a J-shaped tip shape, a medical guide wire that eliminates the need for an insertion aid such as an inserter and achieves excellent operability at each stage and safety against the blood vessel wall. Made it possible to provide.

  To explain this in more detail, the performance required for a medical guide wire having a J-shaped tip shape includes insertion into an introduction needle, a catheter and a sheath, prevention of invasion into a branch blood vessel, and blood vessels caused by a wire tip. It is particularly important to scratch the lumen including it and to prevent it from hitting, and it is possible to provide a medical guide wire that can realize these in a well-balanced manner.

Such an object is achieved by the present inventions (1) to (6) below.
(1) A medical guide wire comprising a core wire having a distal end portion and a covering portion made of resin that covers at least the distal end portion of the core wire and has a curved portion. ,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The wire diameter change rate in the tapered portion is 40 to 55%,
The medical guide wire, wherein the cross-sectional center point of the core wire and the cross-sectional center point of the covering part in the tip shape part are different in position.

  (2) The medical guide wire according to the above (1), wherein a cross-section of the fine tip portion is substantially circular and a diameter thereof is 0.08 to 0.13 mm.

  (3) The medical guide wire according to (1) or (2), wherein the tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion. .

(4) A medical guide wire comprising a core wire having a distal end portion and a covering portion made of resin that covers at least the distal end portion of the core wire and has a curved portion. ,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion,
The medical guide wire, wherein the cross-sectional center point of the core wire and the cross-sectional center point of the covering part in the tip shape part are different in position.

  (5) The medical guide wire according to any one of (1) to (4), wherein the core wire of the curved portion is flat.

(6) A medical guide wire comprising a core wire having a distal end portion and a covering portion made of resin that covers at least the distal end portion of the core wire and has a curved portion. ,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion,
The core wire of the curved portion is flat, and in the cross section of the curved portion, the thickness of the curved portion in the radius direction of curvature is smaller than the thickness in the direction perpendicular thereto. Medical guide wire.

  The medical guide wire of the present invention has excellent stiffness near the distal end, and can be inserted into the introduction needle, catheter, and sheath very simply without using an inserter, thereby improving operability. In addition, since the flexibility of the curved portion increases, even if the curved portion is expanded and inserted into the blood vessel, the blood vessel wall is hardly damaged.

It is sectional drawing which shows one structural example of a medical guide wire. It is a side view which shows the core wire of a medical guide wire. It is sectional drawing which shows the other structural example of a medical guide wire. It is sectional drawing which shows the other structural example of a medical guide wire. It is sectional drawing which shows the other structural example of a medical guide wire. It is sectional drawing which shows the other structural example of a medical guide wire. FIG. 7 is an enlarged partial end view of FIG. 6. It is sectional drawing which shows one Embodiment of the medical guide wire of this invention. FIG. 9 is an enlarged partial end view of FIG. 8. It is sectional drawing which shows other embodiment of the medical guide wire of this invention. FIG. 11 is an enlarged partial end view of FIG. 10.

  FIG. 1 is a cross-sectional view showing a configuration example of a medical guide wire, and FIG. 2 is a side view showing a core wire of the medical guide wire.

  First, the configuration of the medical guide wire of the present invention will be described based on a medical guide wire 1A which is a configuration example of a medical guide wire. As shown in FIG. 1, the medical guide wire 1 </ b> A includes a core wire 10 having a distal end portion 12 and a covering portion 30 that covers at least the distal end portion 12 of the core wire 10 and is made of resin. The medical guide wire 1A has a tip-shaped portion 50 having a curved portion. As shown in FIG. 2, the distal end portion 12 of the core wire 10 includes a tapered portion 14 whose outer diameter continuously changes and a distal end fine portion 16 provided on the distal end side thereof. The taper portion 14 has a taper starting portion 14a where the outer diameter starts increasing toward the base end side and a taper end portion 14b where the outer diameter ends increasing.

  The wire diameter change rate in the present invention is determined as follows. As shown in FIG. 2, the outer diameter of the taper start portion 14a is φ1 (mm), the core outer diameter of the taper end portion 14b is φ2 (mm), and the length from the taper start portion 14a to the taper end portion 14b is as follows. Assuming L1 (cm), the wire diameter increase rate α of the tapered portion 14 is obtained as (((φ2−φ1) / φ1) × 100) / L1, that is, the wire diameter increase rate per 1 cm. In the present invention, α is 40 to 55%, more preferably 45 to 50%. When α is less than 40%, the position where the medical guide wire is held at the initial stage of insertion into a catheter or the like is on the distal end side with respect to the tapered end portion 14b, and frequent holding is necessary. Therefore, a burden is imposed on the work of inserting the medical guide wire into the catheter or the like. Holding near the tip of a medical guidewire can affect the lubricious coating on the surface, impairing slippage, and depending on the core wire material, can cause bending and wrinkles by holding it too strongly Becomes higher. When α is greater than 55%, the insertability tends to improve, but the operability in the catheter is poor. In addition, if the tip of the medical guide wire is trapped in the blood vessel, the possibility that the core wire is broken cannot be denied.

  The core wire 10 in the medical guide wire of the present invention has an outer diameter of 0.33 to 0.82 mm. Moreover, the cross section of the distal end fine portion 16 of the core wire 10 is substantially circular, and the outer diameter thereof is preferably 0.08 to 0.13 mm, more preferably 0.08 to 0.12 mm. There are many situations where the tip is opened in a catheter or a thin blood vessel, and in recent years, if the outer diameter of the tip fine portion 16 of the core wire 10 is larger than 0.13 mm, “the tip is hard. There is a tendency to be repelled as “hard to operate”. In addition, when the outer diameter of the fine tip portion 16 of the core wire 10 is smaller than 0.08 mm, although the softness of the tip is increased, it is difficult to manufacture and becomes weak against a tensile load. This is not preferable because the risk of breaking in the body is expected to increase. The cross-section of the tip fine portion 16 may be a flat shape such as a rectangle or an ellipse. The tip fine part 16 is more flexible than the taper part 14, so that the possibility of damaging the blood vessel is reduced even when the tip fine part 16 precedes the blood vessel.

  The length of the fine tip portion 16 of the core wire 10 is preferably 8 to 15 mm, and more preferably 11 to 15 mm. When the distal fine part 16 is in the above range, it is difficult for the distal branch of the medical guide wire to rub on the blood vessel wall, and the distal end of the medical guide wire is less likely to rub against the blood vessel wall.

  The cross-sectional shape of the tip fine part 16 is circular. The cross-sectional shape of the distal fine portion 16 is substantially the same in the length direction, but it may be gradually narrowed in the distal direction as shown as the medical guide wire 1B in FIG. By gradually narrowing, the distal end portion of the medical guide wire is the most flexible when advanced into the blood vessel with the distal end shape portion 50 expanded, and the effect of preventing damage to the inner wall of the blood vessel can be further enhanced. it can. When the tip fine part 16 becomes gradually thinner in the tip direction, the rate of change of the outer diameter is preferably smaller than the above-described wire diameter increase rate α. When the cross section of the tip fine part 16 is flat, it is preferable that the cross-sectional area gradually decreases in the tip direction. The tip fine portion 16 is linear in FIG. 1, but may be curved in a direction different from the tip shape portion 50. For example, the tip fine part 16 is preferably curved in the direction opposite to the tip shape part 50. The tip of the fine tip portion 16 may be curved in a direction of a predetermined angle (20 to 90 °) from a plane formed by the curved portion.

  The medical guide wire 1A has a tip-shaped portion 50 having a curved portion. As shown in FIG. 1, the tip shape portion 50 includes a shape called a “J shape”, a beak shape, and a shape combining a J shape and an angle shape. By having the tip shape part 50, even if it strikes against the inner surface of the blood vessel, the force is dispersed and the influence is suppressed.

  The taper starting portion 14a of the distal end portion 12 of the core wire 10 in the medical guide wire 1A is preferably in a curved portion of the distal end shape portion 50, and the distal end side is viewed from the proximal end side as shown in FIG. In this case, it is more preferable to be in the vicinity of the position corresponding to the most protruding portion (J-shaped vertex T). When a medical guide wire is inserted into a catheter or the like, the J shape needs to be expanded and stretched, but moderate anisotropy is imparted to the hardness of the curved portion (tip shape portion 50) such as the J shape. By doing so, high flexibility (easiness of spreading) on the distal end side and firmness (ease of pushing) on the proximal end side can be realized.

  That is, when the taper starting portion is located on the base end side from the curved portion such as the J shape, the hardness of the shaped portion is substantially uniform (isotropic). Therefore, since the stiffness of the proximal end side is insufficient, it does not contribute much to the improvement of insertion into a catheter or the like. On the other hand, when the taper starting portion 14a is on the tip side from the J-shaped curve, there is a possibility that a force necessary to widen the J-shaped portion (a spreading load on the tip-shaped portion) becomes large.

  Since the taper starting portion 14a of the distal end portion 12 of the core wire 10 is in the curved portion of the distal end shape portion 50, the stiffness of the proximal end side is utilized, so that the insertion into a catheter or the like is improved. The In addition, since the force required to widen the J-shaped part (expanding load of the tip-shaped part) is small, the lumen of the catheter or the like passes through a small lumen and becomes cheap, and a medical guide wire in the blood vessel When the blood vessel is caught in the branch blood vessel during extraction, the load applied when it comes out of the branch portion is reduced, so that the influence on the branch portion is reduced.

  As shown in FIG. 1, the tip shape portion 50 of the core wire 10 has a portion where the cross-sectional area of the core wire 10 gradually decreases in the tip direction.

  FIG. 3 shows another embodiment in which the taper starting portion 14 a is between the distal end portion and the proximal end portion of the curved portion (curved portion) of the distal end shape portion 50. In this medical guide wire 1B, the taper starting portion 14a is located on the proximal side with respect to the apex T of the distal shape portion 50 and on the distal side with respect to the proximal end portion of the curved portion. Also, the medical guide wire 1C of FIG. 4 has the taper starting portion 14a on the proximal side with respect to the apex T of the distal shape portion 50 and on the distal side with respect to the proximal end portion of the curved portion. In the medical guide wire 1D of FIG. 5, the taper starting portion 14a is on the distal end side with respect to the apex T of the distal shape portion 50 and on the proximal end side with respect to the distal end portion of the curved portion.

Stiffness strength in the medical guide wire of the present invention, 1. It is preferably 5 gf (0.0147 N, provided that gravitational acceleration G = 9.8 m / s ² , the same shall apply hereinafter) or more, and more preferably 2.0 gf (0.0196 N) or more. If the stiffness at the above position is less than 1.5 gf (0.0147 N), it will not be possible to overcome the pushing resistance caused by expanding and stretching the J shape in the initial stage of insertion into a catheter or the like. Since it becomes complicated, it is not preferable. Here, this stiffness is obtained as follows. Average the position of 50mm from the apex of the distal shape portion of the medical guide wire horizontally fixed and measured 3 times a maximum load when depressed 2mm in the distal shape portion apex 5 mm / a position of 30mm proximal side from min of Calculated by value.

Preferably spread the load of the distal shape portion in the medical guide wire of the present invention is less than 15 gf (0.147 N), and more preferably less 10 gf (0.098 N). Furthermore, it is preferable that it is 6-10 gf (0.0588-0.098N) . When the spreading load of the tip-shaped part is larger than 15 gf (0.147 N) , the passage through a lumen such as a catheter is small, and the risk of pulling out a medical guide wire (hangs on a branch vessel) This is not preferable because the load on the branching part) increases. The spreading load of the tip-shaped portion can be obtained as an average value obtained by measuring the maximum load when the tip-shaped portion is drawn into a polyethylene tube having an inner diameter of 2 mm at 5 mm / min three times.

In the medical guide wire 1A, the distal shape portion 50 has a curved portion, and the radius of curvature of the curved portion is indicated by r as shown in FIG. 1, and r is preferably 1 to 3 mm. More preferably, it is 1.5-2 mm. When the puncture site is the wrist (radial) , the inner diameter of the blood vessel is often 3 to 5 mm. Therefore, if the radius of curvature is greater than 3 mm, the resistance in the blood vessel increases and the operability deteriorates. It is not preferable because it may be damaged by spreading. Also, the smaller the radius of curvature, the less likely to get caught at the inlet when inserted into a catheter or the like, and the insertability tends to decrease, so that it is preferably 1 mm or more.

  The opening angle of the tip-shaped portion 50 in the medical guide wire of the present invention is indicated by b as shown in FIG. The opening angle b is preferably 0 to 30 °, and more preferably 10 to 20 °. Similar to the radius of curvature, the smaller the opening angle of the distal end portion, the more difficult it is to be caught in the inlet portion when inserted into a catheter or the like, and the insertion property tends to decrease. It is not preferable because it deteriorates. Conversely, the larger the opening angle, the better the insertability. However, if the opening angle is larger than 30 °, the angle of the medical guide wire tip with respect to the blood vessel wall becomes larger and the blood vessel wall is easily scratched and removed. When it does, it becomes easy to get caught in a branch blood vessel, Therefore The possibility of damaging a blood vessel wall becomes high. For example, the embodiment of FIGS. 1 and 5 has an opening angle of 20 °, and the embodiment of FIGS. 3 and 4 has an opening angle of 10 °.

  The material used for the core wire 10 is appropriately selected as long as it has the characteristics used for the application, such as a metal material such as Ni-Ti alloy, stainless steel, Cu alloy, Al alloy, or synthetic resin. However, a Ni—Ti alloy is preferable in terms of flexibility.

  The tip end portion 12 of the core wire 10 is covered with a covering portion 30. In the medical guide wire 1 </ b> A, the entire core wire 10 is covered with the covering portion 30, but there is an aspect in which there is no covering portion 30 except for the distal end portion 12. Further, as will be described later, the distal end portion 12 may be covered with a resin that can be coated with a hydrophilic coating, and the proximal end portion may be covered with another resin such as silicone or fluororesin.

  As the resin material of the covering portion 30, polyurethane, polyamide elastomer, polyester elastomer, polyolefin elastomer, or a polymer containing fluorine, chlorine, or the like is mainly used because the coating on the core wire 10 and the outer surface of the resin must be lubricated. A polymer material such as a polymer alloy as a component is used so that it does not interfere with the bending of the core wire, and the outer surface is molded smoothly to the extent that it does not hinder the operation in the blood vessel. Is done. Moreover, it is also possible to mix metal fine particles having high X-ray contrast properties such as tungsten, bismuth and barium in the coating material.

  The outer surface of the coating material is coated with a hydrophilic polymer in order to reduce frictional resistance with the inner surface of the introduction needle, the catheter and the sheath, and further to the inner wall of the blood vessel and realize good operability. .

  The hydrophilic polymer has many hydrophilic groups such as vinyl ether-maleic anhydride copolymer, vinyl ether-maleic anhydride copolymer salt, polyethers, polyacrylate, polymethacrylate, polyvinylpyrrolidone and the like. Polymers can be used.

  The medical guide wire 1A can be easily inserted into an introduction needle, a catheter, and a sheath without using an insertion assisting instrument such as an inserter, and in the process of being introduced into a target site in a blood vessel including the heart, the branch blood vessel It is possible to achieve both the safety that it is difficult to scratch or hit the blood vessel wall without getting into the body.

A medical guide wire will be described below with reference examples.
About the core wire 10, the core wire diameter change rate (α) of the taper portion is 40%, the tip fine portion 16 has a circular cross section, an outer diameter (φ1) of 0.11 mm, and a length of about 12 mm. The outer diameter is almost the same in the length direction, the taper starting portion 14a is processed so as to be positioned at the apex of the tip shape portion 50, the opening angle b of the tip shape portion 50 is about 20 °, and the curvature radius is 2 mm. Produced a core wire made of Ni-Ti alloy in J shape, then coated with urethane resin on its outer surface, and further coated with lubricious coating on its surface, the proximal end outer diameter is 0.85mm for medical use A guide wire was prepared. This medical guide wire was referred to as Reference Example 1. This medical guide wire had a stiffness of 1.8 gf (0.07664 N) and a spreading load of 8.8 gf (0.086624 N) .

As Reference Example 2 and Reference Example 3, a medical guide wire having the same material and structure as Reference Example 1 was prepared except that the core wire diameter change rate α was 55% and 47%, respectively. The medical guidewires of Reference Example 2 and Reference Example 3 have a stiffness of 3.3 gf (0.03234N) and 2.8 gf (0.02744N) , and a spreading load of 13.2 gf (0.12936N) , 10 0.6 gf (0.10388 N) .

As Comparative Example 1, a medical guide wire having the same material and structure as Reference Example 1 was produced except that the core wire diameter change rate α was 33%. Further, as Comparative Example 2, a medical guide wire having a core wire diameter change rate α of 20%, a taper starting portion 30 mm from the apex of the distal end shape to the proximal end side and not at the distal end shape portion was manufactured. Further, as Comparative Example 3, a medical guide wire having the same material and structure as Reference Example 1 was prepared except that the core wire diameter change rate α was 66%. Regarding the medical guide wires of Comparative Examples 1 to 3, the stiffness is 1.3 gf (0.01274 N) , 0.6 gf (0.00588 N) , 4.0 gf (0.0392 N) , respectively, and the spreading load is 6. 7 gf (0.06566 N) , 4.5 gf (0.0441 N) , and 15.5 gf (0.1519 N) .

  A test comparing insertability was performed as follows. The arbitrary position of the proximal end side of the distal end shape portion of the medical guide wire is held, and the maximum distance from the apex of the distal end shape portion to the holding position at which the 4 French can be inserted into the angiographic catheter was measured three times. . As a result, Reference Example 1 had an average of 8 cm, Reference Example 2 had an average of 10 cm, and Reference Example 3 had an average of 9 cm.

  In the medical guide wire of this reference example, the end of the taper end of the core wire is approximately 70 mm from the apex of the tip shape. Therefore, if α is 40% or more, the hardness of the medical guide wire is uniform. This means that it can be inserted into a catheter or the like even in a state where the shaft portion to be held is held. The tip of the medical guide wire is extremely flexible and sensitive, which affects the slidability in the blood vessel, greatly reducing the burden of frequent changes during the initial stage of medical guide wire insertion. What can be done has great clinical significance.

  As a result of carrying out the same measurement for Comparative Example 1, the average value of the maximum distance is 5 cm, and in the initial stage of insertion, the vicinity of 3 cm from the apex of the tip shape portion is bent, so that the waist is crumbled, and the holding operation is somewhat complicated. Met. Moreover, about the comparative example 2, the average value of the maximum distance was 2 cm, and the change-over operation in the initial stage of insertion was further complicated. Further, in Comparative Example 3, the average value of the maximum distance was 12 cm.

Next, the twist test was performed as follows. After removing the coating of the medical guide wire, the core wire tip is fixed and twisted continuously in the same direction while applying a load of 200 gf (1.96 N) over a 50 cm span, and the number of twists until it breaks (twist The breaking strength was measured three times.

  For the core wire of Reference Example 2, the average value was 9 times and the minimum value was 7 times. Conventionally, various types of medical guidewires used at medical sites have the lowest torsional break strength and are at the same level as this reference example. It can be said that it is at an acceptable level because it is considered necessary to not break. On the other hand, the core wire of Comparative Example 3 had an average number of twists until breakage of 6 and the minimum value was 4. Therefore, it can be said that it is not an acceptable level when considering actual use.

Next, as a result of confirming the behavior when the medical guide wire of Reference Example 2 was inserted through a 6 Fr sheath into a silicone tube having an inner diameter of 3 mm assuming the lower arm portion, the J shape was expanded and stretched. However, since the J-shaped tip smoothly advances along the wall of the tube, the wall was not scratched at the leading edge. Furthermore, since the distal end portion of the medical guide wire moves over the toroidal branch portion (the major axis of the inlet portion is about 4 mm) installed assuming the blood vessel branch, no accidental entry into the branch pipe occurred.

  Next, the behavior of the blood vessel model using the medical guide wire of Comparative Example 3 was almost the same as that of Reference Example 2, but the resistance when pushing into the catheter was large. From this, it was confirmed that the operability of the medical guide wire deteriorates when the wire diameter change rate of the tapered portion is too large.

  Next, another embodiment of the medical guide wire of the present invention will be described with reference to FIGS. Description of matters similar to those in the above-described embodiment will be omitted, and differences will be mainly described.

  A medical guide wire 1E shown in FIG. 6 has a groove 32 on the surface of the covering portion 30 at least inside the curved portion 55 in a direction substantially perpendicular to the axis. The groove 32 is provided in a spiral shape. The groove 32 is provided around the entire surface of the covering portion 30 of the curved portion 55. The groove 32 is provided only on the surface of the covering portion 30 of the curved portion 55. The cross section of the groove 32 is wavy as shown in FIG. The wavy groove 32 can be obtained, for example, by winding a wire around the covering portion 30 while leaving a gap corresponding to the outer diameter of the wire and heating the wire.

  The groove 32 may be annular instead of spiral. A slit shape may be used instead of the groove 32. The groove 32 may be provided only on the surface of the covering portion 30 inside the curved portion 55. The groove 32 may be provided on the surface of the covering portion 30 of the tip shape portion 50 including the curved portion 55.

  In the medical guide wire 1E, the flexibility of the curved portion 55 is increased by having the groove 32 or the slit substantially orthogonal to the axial direction on the surface of the covering portion 30 at least inside the curved portion 55. Even if the curved portion 55 is inserted into a blood vessel in a state where the curved portion 55 is expanded, the blood vessel wall is hardly damaged. That is, since the J-shaped distal end portion advances smoothly in parallel with the blood vessel wall, the blood vessel wall is not scratched at the most distal portion.

  Next, an embodiment of the medical guide wire of the present invention will be described with reference to FIGS. Description of matters similar to those in the above-described configuration example will be omitted, and differences will be mainly described.

  In the medical guide wire 1F shown in FIG. 8, the core wire 10 of the curved portion 55 has a thickness in the radius direction of curvature of the curved portion 55 that is smaller than the thickness in the direction perpendicular thereto. The upward direction in FIG. 9 is the left direction in FIG. 8 and represents the direction of the radius of curvature of the curved portion 55. As shown in the AA end view of FIG. 9, the thickness of the curved portion 55 in the radius direction of the core wire 10 is smaller than the thickness in the direction perpendicular to the radius of curvature direction. The cross section of the core wire 10 of the curved portion 55 is preferably flat. The cross section of the core wire 10 of the curved portion 55 can be, for example, a short axis a of 0.05 mm and a long axis b of 0.19 mm. In the cross section of the covering portion 30 of the curved portion 55, the thickness of the curved portion 55 in the radius direction of curvature is smaller than the thickness in the direction orthogonal thereto. For example, the thickness A in the curvature radius direction of the curved portion 55 can be 0.79 mm, and the thickness B in the direction orthogonal to the curvature radius direction can be 0.88 mm. As shown in the BB end view of FIG. 9, the cross section of the core wire 10 of the tip thin portion 16 is substantially circular. For example, the diameter can be 0.11 mm. The cross-sectional area of the flat core wire 10 is preferably substantially the same as the circular cross-sectional area of the core wire of the tip thin portion 16. The cross section of the covering portion 30 of the tip fine portion 16 is substantially circular. As shown in the CC end view of FIG. 9, the cross section of the core wire 10 of the taper portion 14 is substantially circular. It is preferable that the cross-sectional area of the core wire 10 of the taper portion 14 is larger than the cross-sectional area of the core wire 10 of the tip thin portion 16. The cross section of the covering portion 30 of the covering portion 30 of the taper portion 14 is substantially circular. The cross-sectional areas of the covering portion 30 and the core wire 10 of the tapered portion 14 are preferably larger than the cross-sectional areas of the covering portion 30 and the core wire 10 of the fine tip portion 16. The cross-sectional areas of the covering portion 30 and the core wire 10 in the curved portion 55 are preferably smaller than the cross-sectional areas of the covering portion 30 and the core wire 10 in the thin tip portion 16.

  In the medical guide wire 1F, the core wire 10 of the curved portion 55 has a thickness in the radius direction of curvature of the curved portion 55 smaller than the thickness in the direction orthogonal to the cross section of the covering portion 30 of the curved portion 55. As a result, the flexibility of the curved portion 55 is increased, so that it is difficult to damage the blood vessel wall even if the curved portion 55 is inserted into the blood vessel in an expanded state. In the cross section of the covering portion 30 of the curved portion 55, the thickness of the curved portion 55 in the radius direction of curvature is smaller than the thickness in the direction orthogonal thereto, thereby increasing the flexibility of the curved portion 55. Even if the curved portion 55 is inserted into the blood vessel in a state where the curved portion 55 is expanded, the blood vessel wall is hardly damaged. Since the cross-sectional area of the flat core wire 10 is substantially the same as the cross-sectional area of the circular core wire, it is possible to make the curved portion 55 flexible without reducing the strength.

  Next, another embodiment of the medical guide wire of the present invention will be described with reference to FIGS. Description of the same matters as the above-described configuration example and embodiment will be omitted, and differences will be mainly described.

  In the medical guide wire 1G shown in FIG. 10, the cross-sectional center point of the core wire 10 and the cross-sectional center point of the covering portion 30 in the distal shape portion 50 are different in position. The upward direction in FIG. 11 is the left direction in FIG. 10 and represents the direction of the radius of curvature of the curved portion 55. As shown in the DD end view of FIG. 11, the cross section of the core wire 10 and the covering portion 30 are both substantially circular. The cross-sectional center point 10D (represented by “☆”) of the core wire 10 is displaced in the direction of the radius of curvature of the curved portion 55 from the cross-sectional center point 30D (represented by “◎”) of the covering portion 30. With respect to the core wire 10, the thickness of the covering portion 30 is thicker on the inner side (lower side in FIG. 11) of the curved portion 55 than on the outer side (upper side in FIG. 11). The cross-sectional center point 30 </ b> D of the covering portion 30 is preferably located within the cross section of the core wire 10. As shown in the EE end view of FIG. 11, the cross-sectional center point 10 </ b> E (represented by “☆”) of the core wire 10 is curved more than the cross-sectional center point 30 </ b> E (represented by “◎”) of the covering portion 30. The portion 55 is displaced in the direction of the radius of curvature. It is preferable that the cross-sectional center point 30 </ b> E of the covering portion 30 is located outside the cross-section of the core wire 10.

  In the medical guide wire 1G, since the cross-sectional center point of the core wire 10 and the cross-sectional center point of the covering portion 30 in the distal end shape portion 50 are different in position, the flexibility of the curved portion 55 is increased. Even if it is inserted into a blood vessel with the portion 55 expanded, it is difficult to damage the blood vessel wall.

  In the present invention, the aforementioned characteristic portions of the medical guide wires 1A to 1G may be combined. For example, the cross-sectional center point of the core wire 10 and the cross-sectional center point of the covering portion 30 in the distal shape portion 50 are applied to a medical guide wire having a small thickness in the direction of the radius of curvature of the curved portion 55 of the core wire 10. May be configured to have different positions. In addition, one of the medical guide wires 1A to 1C and one or more of the characteristic portions of the medical guide wires 1F to 1G may be combined.

The medical guide wire of the present invention introduces a medical device such as a catheter or a sheath from a wrist (radial) , an upper arm (brachial), and a thigh (femoral) to a target site such as a chest or abdomen. Therefore, the applicable range is not limited by the puncture site or the target site.

1A, 1B, 1C, 1D, 1E, 1F, 1G Medical guide wire 10 Core wire 10D Cross-section center point 10E Cross-section center point 12 Tip portion 14 Taper portion 14a Taper start portion 14b Taper end portion 16 Tip fine object portion 30 Covering Part 30D Section center point 30E Section center point 32 Groove 50 Tip shape part 55 Curved part 70 Coil

Claims (6)

A medical guide wire comprising a core wire having a distal end portion, a covering portion made of resin, covering at least the distal end portion of the core wire, and having a distal end shape portion having a curved portion,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The wire diameter change rate in the tapered portion is 40 to 55%,
The medical guide wire, wherein the cross-sectional center point of the core wire and the cross-sectional center point of the covering part in the tip shape part are different in position.   The medical guide wire according to claim 1, wherein a cross-section of the fine tip portion is substantially circular and a diameter thereof is 0.08 to 0.13 mm.   The medical guide wire according to claim 1, wherein the tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion. A medical guide wire comprising a core wire having a distal end portion, a covering portion made of resin, covering at least the distal end portion of the core wire, and having a distal end shape portion having a curved portion,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion,
The medical guide wire, wherein the cross-sectional center point of the core wire and the cross-sectional center point of the covering part in the tip shape part are different in position.   The medical guide wire according to any one of claims 1 to 4, wherein the core wire of the curved portion is flat. A medical guide wire comprising a core wire having a distal end portion, a covering portion made of resin, covering at least the distal end portion of the core wire, and having a distal end shape portion having a curved portion,
The tip portion of the core wire is provided with a taper portion whose outer diameter continuously changes, and a tip fine portion portion positioned on the tip side of the taper portion and more flexible than the taper portion,
The tapered portion has a start portion and an end portion, and the start portion is located at the curved portion of the tip shape portion,
The core wire of the curved portion is flat, and in the cross section of the curved portion, the thickness of the curved portion in the radius direction of curvature is smaller than the thickness in the direction perpendicular thereto. Medical guide wire.

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