JP2011206413A - Medical guide wire, and assembly of medical guide wire and microcatheter or of balloon catheter and guiding catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that a coil body including a small-diameter distal end and a large-diameter rear end is liable to be formed into a so-called narrow coil body with high rigidity, because the spring constant of the coil body is inversely relates to a coil mean diameter and the spring constant of a small-diameter coil body increases by an outer-diameter difference (similar to a mean-diameter difference of the coil), and that, in such a case, the characteristics of fatigue resistance should be improved with respect to the torsional rotation.SOLUTION: This medical guide wire includes the coil body increasing the number of windings (reducing the coil pitch) without changing the longitudinal length of the small-diameter coil body for suppressing the increase in the spring constant caused by the outer-diameter difference of the coil body and improving the characteristics of fatigue resistance to the repetitive torsional rotation based on a definite relationship between the spring index and a stress correction factor.

Description

  The present invention relates to a medical guide wire in which a coil spring body with improved spring characteristics is attached to a distal end portion.

  The coil spring body attached to the distal end of the medical guide wire to be inserted into the blood vessel must satisfy the safety requirements for the human body in consideration of the mechanical strength characteristics even though it is a thin wire. Has been made.

  Patent Document 1 describes that a coil spring body attached to a distal end portion of a medical guide wire is composed of a loosely wound portion and a densely wound portion. However, this technical purpose is a technical content for receiving the soft lesion tissue between the coil wires and grasping the tip position, and the technical idea considering the improvement of the original spring characteristics of the coil spring body and the mechanical characteristics is described. Absent.

  Patent Document 2 has a description in which resin is filled in a coil spring body attached to a distal end portion of a medical guide wire. However, this technical purpose is to improve the rigidity and pushability, and there is no description of the technical idea about the correlation between the original spring characteristics of the coil spring body and the torsional rotational force and fatigue resistance characteristics. Absent.

Japanese Patent No. 3762290 Japanese Patent Laid-Open No. 11-276596

In a conventional medical guide wire, the coil spring body attached to the distal end portion is provided with a loosely wound portion and a densely wound portion, and accepts soft lesion tissue between the coil wires to recognize the operator's distal end position or radioscopy. The original spring characteristics and mechanical characteristics of the coil spring body as a medical guide wire only by the presence or absence of visibility of the operator below or the technical idea of simply improving the rigidity by embedding synthetic resin in the coil spring body There is no technical idea that takes these into consideration.
The object of the present invention is to provide a coil spring body having a small outer diameter caused by a difference in the outer diameter, in a coil spring body having a different outer diameter attached to the distal end when the operator rotates the proximal portion of the medical guide wire. Torsional bending stress generated in the coil spring body is suppressed by changing the number of turns of the coil wire (changing the coil pitch) without changing the length of the coil spring body. It is intended to provide a medical guide wire that can be operated safely by an operator by disclosing a technical idea related to a medical guide wire provided with a coil spring body that relieves fatigue and repeatedly improves fatigue resistance.

According to the first aspect of the present invention, a core wire composed of a flexible elongated body, a coil spring body having the core wire inserted through the distal end portion of the core wire, and a leading end portion of the core wire and the distal end portion of the coil spring body are attached. In the medical guide wire in which the stopper is formed, the coil spring body is formed by winding and forming a metal wire having the same wire diameter from the proximal side to the distal end portion, the rear end side equal diameter large diameter portion coil body, and the distal end side. A coil pitch of the front end side equal diameter small diameter coil body, and a torsion coil of the rear end side equal diameter large diameter coil body and the front end side equal diameter small diameter coil body. The spring constant ratio is composed of a certain relational expression.
With this configuration, the spring constant of the coil spring body having a small outer diameter resulting from the difference in the outer diameter of the coil spring body is suppressed while increasing the spring characteristics of the coil spring body when forming a coil using a thin wire, and the spring constant is increased. Accordingly, it is possible to provide a medical guide wire that eliminates the increase in rigidity of the coil spring body accompanying the above, improves flexibility and allows soft touch to the blood vessel wall.

According to a second aspect of the present invention, a core wire made of a flexible elongated body and a coil spring body that is inserted through the core wire at a tip end portion of the core wire are mounted as in the first aspect, and the core wire and the coil spring body are mounted. In the medical guide wire in which a leading plug is formed at the distal end of the coil spring body, the coil spring body is formed by winding and forming a metal wire having the same wire diameter from the proximal side to the distal end, and the rear-end-side equal-diameter large-diameter portion A coil body and a tip-side equal-diameter small-diameter coil body are formed, the coil pitch of the front-end-side equal-diameter small-diameter coil body, the rear-end-side equal-diameter large-diameter coil body, and the front-end-side equal-diameter small-diameter The spring constant ratio of the torsion coil of the partial coil body is composed of a certain relational expression.
With this configuration, an increase in the spring constant of the coil spring body having a small outer diameter resulting from a difference in the outer diameter of the coil spring body is suppressed, and an increase in the rigidity of the coil spring body accompanying the increase in the spring constant is eliminated, and A medical guide wire that enables soft touch can be provided.

According to a third aspect of the present invention, the outer diameter of the rear end side equal diameter large diameter coil body is 0.4572 mm (0.018 inch) or less, and the rear end side equal diameter large diameter coil body has an outer diameter. was a D ₁ (mm), the outer diameter of the distal end side such diameter smaller-diameter portion coil body in case of a D ₂ (mm), it outer diameter ratio D ₁ / D ₂ is 2.0 to 1.2 A medical guide wire according to any one of claims 1 to 2.
With this configuration, for cardiovascular treatment and lower limb vascular treatment capable of treating in a state where the rigidity increase deterring effect accompanying the increase in the spring constant of the coil spring body having a small outer diameter resulting from the difference in the outer diameter of the coil spring body is increased. A medical guide wire suitable for use can be provided.

In the invention according to claim 4, the length of the coil body in the longitudinal direction is 300 mm or less, and the rear end-side equal-diameter large-diameter portion coil body has an equal-diameter length L ₁ (mm) in the longitudinal direction, The equal diameter length ratio L ₁ / L ₂ of the length L ₂ (mm) in the longitudinal direction of the distal end side equal diameter small diameter coil body is 5 or less. It is a medical guide wire as described in one.
With this configuration, the fluctuation of the spring constant due to the swaying caused by the lengthening of the coil spring body is prevented, and the rigidity increase accompanying the increase of the spring constant of the coil spring body having a small outer diameter due to the difference in the outer diameter of the coil spring body. It is possible to provide a medical guide wire suitable for cardiovascular treatment and lower limb blood vessel treatment which can be treated in a state where the deterrent effect is further enhanced.

According to a fifth aspect of the invention, the spring index of the distal-side such diameter smaller-diameter portion coil body and C _2, when the kp ₂ stress correction factor bend, when said spring index C ₂ is 3 or more, the bending stress correction factor kp ₂ is a medical guide wire according to any one of claims 1 to 4, characterized in that at 1.33 or less.
With this configuration, when a torsional rotation of the coil spring body, particularly when a torsional rotation is applied in the direction of rewinding the coil wire, a stable spring characteristic is obtained by taking an appropriate value for the bending stress correction coefficient inside the coil spring body. Thus, a medical guide wire made of a coil spring body having excellent repeated fatigue resistance can be obtained.

According to a sixth aspect of the present invention, the bending elastic modulus is 600 kgf / cm ² to 6000 kgf / cm ² in the gap between the core wire and the coil spring body and the gap between the coil wires of the coil spring body, and If the tensile elongation at break was filled with 1000% of the elastic body 200% and that the spring index of the distal-side such diameter smaller-diameter portion coil body and C _2, and the bending stress correction coefficient and kp _2, wherein the spring index when C ₂ is 3 or more, the bending stress correction factor kp _2, a medical guide wire according to any one of claims 1 to 4, characterized in that at 1.33 or less.
With this configuration, especially when torsional rotation is applied in the direction of rewinding the coil wire of the coil spring body, it acts as an encouraging action to prevent an increase in bending stress inside the coil spring body, and torsional rotation is performed in the direction of winding the coil wire. When the twisting torsional rotational force is released, the state before the winding can be quickly restored by the intervention of the elastic body, and it has stable spring characteristics and excellent repeated fatigue resistance characteristics. A medical guide wire comprising a coil spring body can be obtained.

The invention according to claim 7 is an assembly of the medical guide wire according to any one of claims 1 to 6, a microcatheter, and a guiding catheter. The outer diameter of the large-diameter portion coil body is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch), and the outer diameter of the distal end side equal diameter small-diameter portion coil body is 0.2286 mm to 0. 3048 mm (0.009 inch to 0.012 inch), the outer diameter of the coil portion with the same diameter and smaller diameter at the front end side is smaller than the outer diameter of the coil body with the same diameter and larger diameter portion at the rear end side, A medical guide wire is formed by winding or twisting a plurality of thick and thin wires with an inner diameter of 0.28 mm to 0.90 mm, and the outer peripheral portion is a convex and concave flexible hollow tube with thick and thin wires. Microcategory The medical guidewire and the microcatheter are inserted into a guiding catheter having an inner diameter of 1.91 mm to 2.67 mm. It is an assembly of a catheter and a guiding catheter.
With this configuration, a medical guide wire having a coil spring body having a small diameter on the tip side and having high spring characteristics is obtained, and the medical guide wire, a perforating function of an obstructed lesion, and advancement of the medical guide wire are obtained. By making an assembly of a microcatheter having a high function to support the reaction force and a guiding catheter having a function to support each reaction force to advance, it can greatly contribute to the treatment of the obstructed lesion.

The invention according to claim 8 is an assembly of the medical guide wire according to any one of claims 1 to 6, a balloon catheter, and a guiding catheter. The outer diameter of the large-diameter portion coil body is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch), and the outer diameter of the distal end side equal diameter small-diameter portion coil body is 0.2286 mm to 0. 3048 mm (0.009 inch to 0.012 inch), the outer diameter of the coil portion with the same diameter and smaller diameter at the front end side is smaller than the outer diameter of the coil body with the same diameter and larger diameter portion at the rear end side, A medical guide wire is inserted into the balloon catheter having an inner diameter of 0.28 mm to 0.90 mm to form a pair, and is inserted into the guiding catheter having an inner diameter of 1.91 mm to 2.67 mm. An assembly of the medical guide wire and a balloon catheter and guiding catheter, characterized in that the easily kissing procedure by inserting the two sets of a pair of the balloon catheter and the medical guide wire.
With this configuration, a medical guide wire equipped with a coil spring body having a small diameter on the distal end side and having high spring characteristics is obtained, and a medical guide wire with high advancing force that is pushed forward by reducing the diameter on the distal end side, and the diameter expansion By inserting each pair of high-function balloon catheters into an assembly with a guiding catheter that has the function of supporting the reaction force of two sets of advancement, it is especially useful for treating lesions in bifurcated lesions. It can contribute greatly.

It is a principal part enlarged view, such as a medical guide wire and a core wire front-end | tip part. (Example 1) It is a stenosis lesion restraint state figure of a medical guide wire tip part. It is bending state explanatory drawing of a coil body. It is a bending stress distribution figure of a coil body, and a relation figure of a spring index and a bending stress correction coefficient. It is the principal part enlarged view of the front-end | tip part of the medical guide wire which filled the elastic body in the coil body. (Examples 2 and 3) It is a connection part principal part enlarged view of a different diameter coil body. It is a state figure of a leg vascular lesion part treatment. It is a principal part enlarged view of the assembly of a medical guide wire and a microcatheter.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a medical guide wire (hereinafter referred to as a guide wire) 1 according to a first embodiment, and a coil spring body (hereinafter referred to as a coil body) in which a distal end side of a core wire 2 is coaxially fitted to a core wire distal end portion 21. ) 3 is mounted, and the coil body 3 has a distal end side equal diameter small diameter coil body 32 having a small outer diameter on the distal end side, and a rear end side equal diameter large diameter section coil body having a large outer diameter on the rear end side. It consists of 31. Further, the proximal side of the core wire distal end portion 21 starts from 0.2 mm in the longitudinal direction using the proximal end portion of the rear end side equal diameter large diameter portion coil body 31 and the joining member 4 such as brazing material or solder. A rear end joint portion 41 joined at 3 mm is formed, and the front end portion of the core wire front end portion 21 is elongated by using the front end portion of the front end side equal diameter small diameter coil body 32 and the joining member 4. A leading plug 5 is formed that is joined in the direction of 0.2 mm to 0.8 mm. In addition, a resin coating 6 such as a fluororesin or a polyurethane resin is formed on the proximal side of the core wire 2 and the outer peripheral portion of the coil body 3, and a hydrophilic coating that exhibits lubrication characteristics when wet on the distal end side of the outer peripheral portion. 7 is formed into a film.

The coil body 3 includes a rear-end-side equal-diameter large-diameter portion coil body 31 having a large outer diameter from the proximal side to the distal end side, and a length in the longitudinal direction gradually changing from the distal end side to the distal end side. The variable diameter portion 33 and the distal end side equal diameter small diameter coil body 32 having a small outer diameter are wound and formed with a metal wire having the same wire diameter. In addition to the stainless steel wire, a radiopaque material such as a tungsten wire, a tungsten alloy wire, a platinum wire, an alloy wire of platinum and nickel, or a gold-plated wire is used as the metal wire.
And said distal end such diameter smaller-diameter portion coil body 32, (0.012 inches 0.009 inches, in Example 1 0.254 mm) coil outside diameter D ₂ is 0.3048mm from 0.2286mm, the coil wire The wire diameter d is 0.050 mm to 0.090 mm (0.060 mm in the first embodiment), the length L ₂ of the equal diameter portion is 10 mm to 60 mm (40 mm in the first embodiment), and the coil pitch P ₂ consists of a certain relational expression described later.
The rear end side equal diameter large diameter coil body 31 has a coil body outer diameter D ₁ of 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch, 0.3556 mm in the first embodiment). 0.014 inch), the wire diameter d of the coil wire is the same as that of the coil body 32 having the same diameter on the tip side, and the length L ₁ of the equal diameter portion is 10 mm to 250 mm (120 mm in the first embodiment). Further, the coil pitch P ₁ is composed of a certain relational expression described later.

Next, the reason why the coil body 3 can be considered as a torsion coil spring will be described. FIG. 2 illustrates the rotating operation of the coil body when the proximal end of the core wire 22 is rotated when the coil body is perforated into the stenotic lesion.
In the illustrations (a) and (b), when the winding direction of the coil body is S-winding (the S letter in the figure and the left screw direction), the core wire proximal portion 22 of the core wire 2 is rotated in the left screw direction (the Z letter in the figure). The coil body on the proximal side from the lesion wall restraining portion 9 is restrained by the rear end joining member 41 and the lesion wall restraining portion 9, and the rotating action rotates as the diameter expanding action, while the lesion wall restraining portion The coil body on the tip side from 9 is constrained by the leading plug 5 and the lesion wall restraining portion 9 and is rotated together with the leading plug 5 by the rotating action in the left screw direction of the core wire tip 21, and the rotating action is reduced in diameter. It rotates as an action.

Next, (c) and (d) are coils when the rotation direction of the core wire proximal portion 22 of the core wire 2 is rotated in the direction of the left-hand screw (the letter S in the drawing) in the opposite direction with respect to the illustrations (b) and (b). In contrast to the illustrations (A) and (B), the coil body at the hand from the lesion wall restraining portion 9 rotates as a diameter reducing action, while the lesion wall restraining portion 9 The coil body on the distal end side rotates as a diameter expanding action.
When the rotational motion of the coil body is considered as the torsional moment of the coil spring, the tangential direction of the wound coil wire is the acting force (W), and the distance from the central axis of the coil body to the coil wire is the length of the arm ( L), the torsional moment M is W × L.
Therefore, when the coil body 3 rotates, it can be considered as a “torsion coil spring body”.

Then, the coil body 3 according to the first embodiment of the present invention includes a rear end side equal diameter large diameter coil body 31 and a front end side equal diameter small diameter coil body 32. In such a case, when the core side proximal portion 22 on the proximal side is rotated, the rotation is transmitted to the rear end side equal diameter large diameter coil body 31, and when the rear end side equal diameter large diameter portion coil body 31 rotates, the front end side, etc. The torsional force (torsion moment) of the small-diameter portion coil body 32 increases by the arm length ratio (outer diameter ratio D ₁ / D ₂ ).
Since the spring constant of the coil body is inversely proportional to the coil average diameter, the spring constant of the coil body increases as the coil average diameter decreases (outside diameter decreases), resulting in a so-called hard coil body with high bending rigidity. As the outer diameter of the coil body decreases, the torsional moment increases, and as the spring constant increases, the possibility of perforating a blood vessel wall or the like increases.
Therefore, in order to prevent this, it is necessary to suppress at least the increase in the spring constant caused by the increase in the torsional force, that is, the difference in the coil average diameter of the coil body (similar to the difference in the outer diameter of the coil body).
For this purpose, since the spring constant of the coil body is inversely proportional to the number of turns, the spring constant can be lowered by increasing the number of turns.
Furthermore, in order to increase the number of turns without changing the overall length of the coil body, it can be achieved by reducing the coil pitch.
That is, in the present invention, the coil body 3 is considered as a “torsion coil spring body”, and even if the outer diameter of the coil body is reduced, the variation of the spring constant of the distal-side equal-diameter small-diameter portion coil body 32 due to the reduction of the outer diameter is reduced. This is based on the technical idea characterized in that this is suppressed without changing the overall length of the coil body, and the blood vessel wall soft touch is enabled while the outer diameter is small.

Next, in order to express the above by a relational expression, when calculating the upper limit value and the lower limit value of the relational expression between the coil pitch P _{2 of} the distal end side equal diameter small diameter coil body 32 and the spring constant ratio, This will be explained in the following sections. Note that the coil average diameter of the rear end side equal diameter large diameter coil body 31 is D ₀₁ (mm), the coil wire diameter is d (mm), the coil pitch is P ₁ (mm), and the equal diameter length in the longitudinal direction is L ₁ (mm), the spring constant is k ₁ (kgf / mm), the number of turns is N ₁ , the coil average diameter of the tip side equal diameter small diameter coil body 32 is D ₀₂ (mm), and the coil wire diameter is d (Mm), the coil pitch is P ₂ (mm), the equal diameter length in the longitudinal direction is L ₂ (mm), the spring constant of the torsion coil is k ₂ (kgf / mm), and the number of turns is N ₂ . Hereinafter, each unit of each symbol is omitted.

A. About the upper limit of the coil pitch P ₂ and the spring constant ratio (k ₂ / k ₁ ) of the tip side equal diameter small diameter coil body 32, the spring constant is inversely proportional to the coil average diameter and the number of turns. It can be represented by the following relational expression (1).
Relational expression (1): k ₂ / k ₁ = D ₀₁ × N ₁ / (D ₀₂ × N ₂ )
= D ₀₁ / D ₀₂ × P ₂ / P ₁ × L ₁ / L ₂
In order to suppress the increase in the spring constant caused by the coil average diameter difference, it is necessary to set the value of D ₀₁ / D ₀₂ × P ₂ / P ₁ to 1 or less in the relational expression (1). The coil pitch P ₂ of the distal end side equal diameter small diameter coil body 32 is expressed by the following relational expression (2).
Relational expression (2): P ₂ ≦ D ₀₂ / D ₀₁ × P ₁
Further, since the upper limit value of the spring constant is such that the value of D ₀₁ / D ₀₂ × P ₂ / P ₁ is 1 or less, the relational expression (1) becomes the following relational expression (3).
Relational expression (3): k ₂ / k ₁ ≦ L ₁ / L ₂

B. Next, the lower limit value of the coil pitch P ₂ and the spring constant ratio (k ₂ / k ₁ ) of the distal end side equal diameter small diameter coil body 32 will be described with reference to FIG.
In general, the lower limit value of the coil pitch is considered to be a length corresponding to the wire diameter of the coil wire when the coil wire is in close contact with the coil body in a straight state.
However, in many cases, the guide wire is pushed forward in the blood vessel with the coil body at the distal end bent in a U-shape before reaching the stenotic lesion, as will be described later. The reason for this is that if it is inserted in a U-shaped bent state, the surface pressure on the blood vessel wall can be lowered due to the U shape, and as a result, damage to the blood vessel wall can be prevented. In particular, when the tip is made thinner, the above-mentioned procedure tends to be used frequently.

FIG. 3 shows a state diagram when the inner diameter (diameter) of the coil body 3 is the same as the outer diameter (D ₀₂ + d) of the coil body 3 and the coil body is bent in a U-shape. Are closely in contact with each other and a gap is opened between the coil wires on the outside.
And, for example, when the coil body is in a straight state and the coil wire is in close contact, when bent into a U shape, a gap is opened between the outer coil wires, and the curvature radius drawn by the outer coil wire is increased accordingly. Changes to R. In this case, as a characteristic required for the guide wire, it is required that the curvature radius does not increase. The reason for this is that if a guide wire having an increased radius of curvature when being bent into a U-shape is pushed to the lesion, the passage through the blood vessel deteriorates and the frequency of vascular wall damage is likely to increase. is there. In order to prevent this and eliminate the increase in the radius of curvature, the coil pitch is opened in advance in the straight state so that the inner coil wires are in close contact with each other when bent into a U shape. That is. (Illustration (d) (e))
The coil pitch P ₂ at this time is set as the lower limit value of the distal end side equal diameter small diameter portion coil body 32.
In the drawings (c) and (e), symbols R and r represent the respective radii of curvature and indicate the relationship of R> r.
In addition, when supplemented, the inner diameter (diameter) of the coil body is the same as the outer diameter (D ₀₂ + d) of the coil body 32 when bent into a U shape. This is because it becomes difficult for them to engage each other, and it becomes difficult to obtain stable spring characteristics.

And, when the above-mentioned contents are expressed by a relational expression, the length of a half circumference drawn by the arc connecting the center points of the circular cross section of the outer coil wire is L (mm), and the center points of the circular cross section of the inner coil body are connected. If the length of the half circumference drawn by the arc is 1 (mm) (FIG. 3 (a)), the inner diameter (diameter) when bent into a U-shape is the outer diameter D of the coil body 32 having the same diameter at the tip side. _{2 Since} it is the same as (D ₀₂ + d), the lengths L and l and the difference (L−l) between the lengths L and l should be expressed by the following relational expressions (4), (5), and (6), respectively. Can do.
Relational expression (4): L = π / (3 × D _02/2 + d)
Relational expression (5): l = π / (D _02/2 + d)
Relational expression (6): L−l = π × D ₀₂
When the number of turns of the inner coil when in close contact is N, the number of turns N can be expressed by 1 / d, and the following relational expression (7) is obtained, and the inner coil pitch is (L-1) / N. The following relational expression (8) can be obtained.
Relational expression (7): N = 1 / d = π × (D ₀₂ + 2d) / (2d)
Relational expression (8): (L−l) / N = D ₀₂ × 2d / (D ₀₂ + 2d)
That is, the minimum value of the coil pitch for opening a gap between the coil wires in a straight state in advance so that the radius of curvature does not increase during U-shaped bending is equal to or larger than the inner coil pitch dimension of the relational expression (8). And it is sufficient. Therefore, the relational expression indicating the lower limit value of the coil pitch P ₂ of the distal end side equal diameter small diameter coil body 32 is the following relational expression (9).
Relational expression (9): D ₀₂ × 2d / (D ₀₂ + 2d) ≦ P ₂

Then, when the lower limit value of the spring constant ratio is calculated from the lower limit value of the coil pitch P ₂ of the front end side equal diameter small diameter coil body 32, the spring constant k ₁ of the rear end side equal diameter large diameter coil body 31 is Since the spring constant k ₂ of the tip side equal diameter small diameter coil body 32 using the lower limit value of the coil pitch P ₂ can be expressed by the relational expression (10), it can be expressed by the following relational expression (11). The relational expression indicating the lower limit value of the spring constant ratio k ₂ / k ₁ is the following relational expression (12).
Relational expression (10): k ₁ ∝P ₁ / (D ₀₁ × L ₁ )
Relational expression (11): k ₂ ∝P ₂ / (D ₀₂ × L ₂ ) = 2d / L ₂ × 1 / (D ₀₂ + 2d) Relational expression (12):
_{k 2 / k 1 = D 01} × L 1 × 2d / {L 2 × (D 02 + 2d) × P 1}

From the above, the relationship between the upper limit value and the lower limit value of the coil pitch P ₂ of the tip side equal diameter small diameter coil body 32 is expressed by the following relational expression (13) from the relational expressions (2) and (9). The relation between the upper limit value and the lower limit value of the constant ratio k ₂ / k ₁ is the following relational expression (14) from the relational expressions (3) and (12).
Relational expression (13): D ₀₂ × 2d / (D ₀₂ + 2d) ≦ P ₂ ≦ D ₀₂ / D ₀₁ × P ₁
Relational expression (14):
D ₀₁ × L ₁ × 2d / {L ₂ × (D ₀₂ + 2d) × P ₁ } ≦ k ₂ / k ₁ ≦ L ₁ / L ₂

In the above embodiment, the inner diameter (diameter) of the coil body is the same as the outer diameter (D ₀₂ + d) of the coil body 32 in an ideal state when bent into a U-shape. An inner diameter increased by% is more desirable. The reason for this is that when the coil body 3 using a thin wire is bent and deformed into a U-shape, the outer diameter of the coil body 3 at the time of coil forming slightly fluctuates, and the inner coil wires resulting from this minute variation are likely to be engaged with each other. This is because it is possible to obtain a stable spring characteristic by eliminating the above, and the number of turns can be increased, thereby making it possible to obtain a coil body with easy bending and a more flexible tip portion. . And if it is this lower limit, the elastic body 8 mentioned later can be filled over the whole region in the coil body 3, but if it falls below this range, the said elastic body 8 is made to the whole region from the gap | interval of the said coil body 32. This is because it becomes very difficult to fill the entire area.

C. Then, when the coil body is bent into a U shape, the coil pitch P ₂ and the spring constant ratio when the inner diameter (diameter) of the coil body is 1.1 times (10% increase) the outer diameter of the coil body 32. The lower limit value of (k ₂ / k ₁ ) will be described.
Similarly to B, in FIG. 3 (a), when the inner diameter of the coil body is 1.1 × (D ₀₂ + d), the inner coil pitch (L−1) / N is expressed by the following relational expression (15). it can be also relational expression indicating the lower limit value of the coil pitch P ₂ of the front end side such diameter smaller-diameter portion coil body 32 can be represented by the following equation (16).
Relational expression (15): (L−l) / N = D ₀₂ × 2d / (1.1D ₀₂ + 2.1d)
Relational expression (16): D ₀₂ × 2d / (1.1D ₀₂ + 2.1d) ≦ P ₂
And then, the spring constant k ₂ of the distal end side such diameter smaller-diameter portion coil body 32 with a lower limit value of the coil pitch P _2, since it can be represented by the following equation (17), the spring constant ratio k ₂ The relational expression indicating the lower limit value of / k ₁ is the following relational expression (18).
Relational expression (17):
k ₂ ∝P ₂ / (D ₀₂ × L ₂ ) = 2d / {L ₂ × (1.1D ₀₂ + 2.1d)}
Relational expression (18):
k ₂ / k ₁ = D ₀₁ × L ₁ × 2d / {L ₂ × (1.1D ₀₂ + 2.1d) × P ₁ }

From the above, the relationship between the upper limit value and the lower limit value of the coil pitch P ₂ of the tip side equal diameter small diameter coil body 32 is expressed by the following relational expression (19) from the relational expressions (2) and (16). The relation between the upper limit value and the lower limit value of the constant ratio k ₂ / k ₁ is the following relational expression (20) from the relational expressions (3) and (18).
Equation _{(19): D 02 × 2d} / (1.1D 02 + 2.1d) ≦ P 2 ≦ D 02 / D 01 × P 1 relation _{(20): D 01 × L} 1 × 2d / {L 2 × (1.1D ₀₂ + 2.1d) × P ₁ }
≦ k ₂ / k ₁ ≦ L ₁ / L ₂

More specifically, when the coil pitch P ₁ of the rear-end-side equal-diameter large-diameter portion coil body 31 is 0.15 mm (2.5 × 0.06 mm), the numerical values of the embodiments of the present invention are When the relational expression (20) is taken into account, the lower limit value and the upper limit value of the spring constant ratio k ₂ / k ₁ are about 2.090 to 3.000. Including this, the coil pitch P ₂ of the distal end side equal diameter small diameter coil body is about 0.069 mm to about 0.098 mm (about 1.14 d to about 1.64 d). be bent deformed shape can push the intravascular without increasing the radius of curvature, and, even when the tip portion coil outside diameter D ₂ of the coiled body 3 is reduced in diameter, the spring constant increases caused by smaller diameter Without changing the overall length of the coil body, Although the diameter is small, the blood vessel wall soft touch similar to that before the diameter reduction can be made possible.
And according to this invention, the guide wire provided with the new technical idea regarding the coil body 3 which has an outer diameter difference (similar to a coil average diameter difference) can be provided.

And then, the outer diameter ratio D ₁ / D ₂ between the outer diameter D ₂ of the outer diameter D ₁ and distal end such diameter smaller-diameter portion coil body 32 at the rear end such large diameter diameter coil body 31 of the coil body 3 1.2 to 2.0 is desirable. Specifically, when the outer diameter ratio D ₁ / D ₂ is 1.2 and the outer diameter D _{2 of} the distal end side equal diameter small diameter coil body 32 is 0.254 mm (0.010 inch), the rear end it is possible to reduce the diameter of than 0.3556mm the outer diameter D ₁ of the side such large diameter diameter coil body 31 is used 0.3048Mm (0.012 inch), and the general (0.014 inches) . In recent years, in particular, in the treatment of occluded lesions, retrograde approach procedures (because the guide wire is not perforated from the blood flow direction to the occluded lesions due to the high success rate of the procedure, the blood flow in which the end of the occluded lesion is in a soft state) In many cases, a procedure to perforate into the occluded lesion from the opposite side of the direction is adopted. In such a case, the progress of insertion into the blood vessel is improved by using a guide wire in which the tip of the present invention is reduced in diameter in the septum Can be made. This is because the retrograde approach procedure uses septal collateral circulation (septal colateral) that develops in the septum, and this septal colateral has a small vessel inner diameter and is called a corkscrew This is because the blood vessel is severely bent and meandered.

Further, the reason why the outer diameter ratio D ₁ / D ₂ is preferably 1.2 to 2.0 is that if the outer diameter ratio D ₁ / D ₂ is less than 1.2, the increase in the outer diameter ratio is suppressed and the distal end portion equal diameter small diameter portion coil body 32 is suppressed. spring constant reduction effect becomes poor, also the outer diameter D ₁ of the rear end side such large diameter diameter coil body 31 if exceeds the 2.0 because would prevent intravascular insertion progressive and large diameter of.
The guide wire for cardiovascular treatment has an outer diameter D ₁ of 0.3556 mm (0.014 inch) or less and an outer diameter ratio D ₁ / D ₂ of 1.2 to 1.56 (eg, 0.014 inch / 0.009 inch) is more desirable, and the guide wire for limb vascular treatment has an outer diameter D ₁ of 0.4572 mm (0.018 inch) or less and an outer diameter ratio D ₁ / D ₂ of 1.33 (example) 0.012 inch / 0.009 inch) to 2.0 is a more desirable form.

Next, the length in the longitudinal direction of the coil body 3 is 300 mm or less, and the equal-diameter length L ₁ in the longitudinal direction of the rear-end-side equal-diameter large-diameter portion coil body 31 and the distal-end-side equal-diameter small-diameter portion coil body 32. The length ratio L ₁ / L _{2 of the same} diameter with the length L ₂ in the longitudinal direction is preferably 5 or less, more preferably 3.3 or less, and even more preferably 1 or less.
The reason for this is that if the equal-diameter length ratio L ₁ / L ₂ exceeds 5, the length in the longitudinal direction of the rear-end-side equal-diameter large-diameter portion coil body 31 becomes longer, and the coil body 3 becomes torsional due to this increase in length. This is because the spring characteristics of the rear end side equal-diameter large-diameter portion coil body 31 are remarkably fluctuated due to the occurrence of “swinging” in which the central axis of the coil is wavy or spiral.
The equal-diameter length ratio is set to 3.3 or less within this range in the cardiovascular treatment guide wire that is thinner than the outer diameter of the lower limb vascular treatment guide wire. The effect of suppressing the increase fluctuation of the spring constant of the small-diameter coil body 32 is high, and the equal diameter length ratio is set to 1 or less within this range, and the effect of suppressing the increase fluctuation of the spring constant is extremely remarkable. Because. The equal-diameter lengths L ₁ and L ₂ exclude the lengths in the joint portion that does not act as a spring action, the leading plug 5, and the rear end joint portion 41.

Next, the relationship between the spring index and the bending stress resulting from repeated fatigue resistance improvement when the coil body 3 is considered as a “torsion coil spring body” will be described.
FIG. 4 (a) shows a stress distribution diagram of the coil body. In the figure, symbol a indicates the torsional stress distribution in the case of a straight axis, and symbol b indicates the torsional stress distribution of the coil body. The maximum value τ of the torsional stress of the coil body is generated inside the coil body and is larger than the maximum value τ ₀ of the straight axis, and the bending stress correction coefficient kb is set to the maximum value τ of the torsional stress τ of the coil body. Can be represented by the following relational expression (21), and when the spring index is C, the bending stress correction coefficient kb can be represented by the following relational expression (22).
Relational expression (21): τ = kb × τ ₀
Relational expression (22): kb = (4 × C ² −C−1) / {4 × C × (C−1)}

When the acting moment of rotating the coil body 3 is in the direction of tightening the coil body by the rotation operation of the core wire hand portion 22 of the guide wire, it is not necessary to consider the bending stress so much. When the acting moment is in the direction of rewinding the coil body, it is necessary to consider the bending stress.
This is because when the coil body is in the direction of tightening, the inner portion of the coil body becomes a compressive stress of bending, and the bending stress correction coefficient kb is a coefficient smaller than 1.
On the contrary, when the acting moment is in the direction of rewinding the coil body, the inner part of the coil body is on the side of the tensile stress of bending, and the stress distribution is when the straight axis is twisted at the inner part of the coil body. This is because the value τ is larger than the stress τ _{0 of the} above. (Fig. 4 (a) Relational expression (21))
In the relational expressions (21) and (22), the maximum value of the torsional stress and the maximum value of the straight axis for the rear end side equal diameter large diameter coil body 31 are τ ₁ , τ ₀ , and the bending stress correction coefficient is kb ₁ , the spring index is C ₁ , the maximum value of the torsional stress is τ ₂ , the maximum value of the straight axis is τ ₀ , the bending stress correction coefficient is kb ₂ , and the spring If the index is C ₂ , the same contents as in the relational expressions (21), (22) and FIGS. 4A, 4B are the rear end side equal diameter large diameter coil body 31, and the front end side equal diameter small diameter. This is true for the partial coil body 32.

FIG. 4B is a diagram showing the relationship between the spring index C and the bending stress correction coefficient kb, with the horizontal axis indicating the spring index, the vertical axis indicating the bending stress correction coefficient.
In the present invention, when the spring index C is 3 or more, the bending stress correction coefficient kb is preferably 1.33 or less. And in the embodiment more specifically, since the coil average diameter D ₀₂ of the distal like diameter smaller-diameter portion coil body 32 is a coil wire diameter d is 0.06mm in 0.194Mm, spring index C ₂ is 3 .23 (0.194 / 0.06), and the bending stress correction coefficient kb ₂ of the coil portion 32 with the same diameter on the tip side in this case is 1.30 from the relational expression (22), which is 1.33 or less. It is a desirable value.
When the spring index C is 3 or more, the reason why the bending stress correction coefficient kb is 1.33 or less is that the coil body 3, particularly the tip end side isometric diameter by rotating the core wire proximal portion 22 of the guide wire. Even if the acting moment of rotation of the small-diameter coil body 32 is the direction of rewinding the coil body 3 or the direction of rewinding after the winding direction is repeated, the characteristics as a “torsion coil spring body” without fatigue. This is because it is possible to provide a guide wire excellent in fatigue resistance, which can stably exhibit long-term use and can withstand repeated use.

Next, a description will be given of a method by which the coil body 3 can stably exhibit the characteristics of the “torsion coil spring body” for a long period of time and can withstand repeated use even when the bending stress correction coefficient is a high value.
FIG. 5 (a) shows a second embodiment of an enlarged main portion of the distal end portion of the guide wire 1. The difference from the first embodiment is that the core wire 2 of the core wire distal end portion 21 and the rear end side equal-diameter large-diameter portion coil. The elastic body made of rubber or the synthetic resin made of elastic material is filled between the coil body 31 and the coil body 32 between the coil body 31 and 32 and the coil body 31 and 32. Thus, the rear end side elastic body 81 and the front end side elastic body 82 are formed.
With this configuration, for example, when a torsional rotation is applied in the direction in which the coil wire of the coil body 3 is rewound, it acts as a facilitating action to suppress an increase in bending stress inside the coil body 3, and on the other hand, the coil wire is wound. When the torsional rotation is applied in the direction, the rear end side elastic body 81 and the front end side elastic body 82 receive a compressive force due to the torsional rotational force, and when the torsional rotational force is released, each elastic body 81, The rebound elastic force against the compressive force 82 can quickly return the coil body 3 to the state before the coil body 3 is wound, and has a stable spring characteristic, so that the repeated fatigue resistance can be improved.

The term “elastic body” as used herein refers to an elastic body whose coil pitches P ₁ and P ₂ have a softness corresponding to the bending deformation when the coil body 3 is bent and deformed in a U shape. An elastic body and an elastic body made of synthetic resin or elastomer resin.
Various twists are made using a platinum wire made of a radiopaque material having a coil wire diameter of 0.050 mm to 0.090 mm, an alloy wire of platinum and nickel, a tungsten wire, and a stainless steel wire. From the results of the coil spring characteristic test and the manufacturing test, the specific elastic characteristics of the elastic bodies 81 and 82 used in the present invention are that the flexural modulus is 600 kgf / cm ² to 6000 kgf / cm ² and the tensile fracture. from desirably 1000% elongation 200%, and more preferably a flexural modulus of from 700 kgf / cm ² at 5000 kgf / cm ^2, and a tensile elongation at break is preferably 800% to 200%, more desirably flexural modulus in 800 kgf / cm ² from 4000 kgf / cm ^2, and a tensile elongation at break of 600% to 200%.

In addition, the specific material names of the elastic bodies include elastic bodies made of rubber such as natural rubber, synthetic rubber, and silicone rubber, as well as polyurethane resins, urethane acrylate resins, fluororesins, polyurethane elastomers, polyamide elastomers, and fluoroelastomers. A heat-crosslinking material and a thermosetting or photo-curing material are used as an elastic body made of a synthetic resin such as the above or an elastomer resin.
The above-mentioned range is desirable for the mechanical characteristics of the elastic body because if the coil body 3 is bent and deformed in a U-shape, the coil wire does not move in response to the bending deformation. This is because the spring property is impaired and the spring characteristics are impaired.
Further, if the value is below the above range, when a twisting rotation is applied in the direction in which the coil body is rewound, the promoting action for suppressing the increase of the bending stress inside the coil body 3 becomes poor.

If it supplements, the front end side elastic body 82 and the rear end side elastic body 81 do not necessarily need to use elastic bodies having the same mechanical characteristics, and the front end side elastic body 82 is more than the rear end side elastic body 81. Alternatively, an elastic body having a low flexural modulus or high tensile elongation at break may be used. Specifically, the tip-side elastic member 82 is used bend 3000 kgf / cm ² modulus of 600 kgf / cm ^2, or, tensile elongation at break of 300% to 1000% of polyurethane elastomer, polyamide elastomer, silicone rubber or the like The rear end side elastic body 81 is made of a polyurethane resin having a flexural modulus of 2000 kgf / cm ² to 6000 kgf / cm ² , or having a tensile elongation at breakage of 200% to 400%, a urethane acrylate resin, and the respective elastomer resins. You may use the elastic body which consists of, or the elastic body which consists of each rubber material.
With this configuration, the tip-side equal-diameter small-diameter portion coil body 82 changes the coil pitch (the length of the coil body by changing the spring constant increase resulting from the coil average diameter difference of the rear-end-side equal-diameter large-diameter portion coil body 81). Not only by suppressing the number of windings without changing, but also by the highly flexible front end side elastic body 82, flexibility can be enhanced as compared with the rear end side equal diameter large diameter portion coil body 81.
Further, the bending rigidity difference between the front-end-side equal-diameter small-diameter coil body 82 and the rear-end-side equal-diameter large-diameter coil body 81 is adjusted by arbitrarily selecting the mechanical characteristics of the elastic bodies 81, 82. It becomes possible to do.

Further, FIG. 5 (b) shows a third embodiment of an enlarged main portion of the distal end portion of the guide wire 1, and the difference from the second embodiment is that the resin coating 6, the hydrophilic coating 7, and the rear end side. That is, a sealed chamber 83 in which gas is not leaked by the elastic body 81 is formed in the coil body 32 having the same diameter and small diameter on the tip side. The gas in the sealed chamber 83 may be air, or an inert gas such as nitrogen gas may be used, and the gas is not sealed to the outside.
With this configuration, when the distal-end-side equal-diameter small-diameter portion coil body 32 is bent and deformed in a U shape and then returned to a straight shape, the gas in the sealed chamber 83 is compressed by the U-shaped bending deformation. The gas pressure in the receiving and sealing chamber 83 is increased, and when it is returned to the straight shape, it can be quickly returned to the straight shape by the repulsive force against the compressive force.
Further, since the rear end side elastic body 81 made of an elastic body is adjacent to the sealed chamber 83, the pressure in the sealed chamber 83 in which the gas pressure has increased when bent and deformed into a U-shape is the adjacent elastic body. Since it is applied to the direction of the body 81 with the same pressure as the outer diameter direction, the pressure direction is dispersed, and the effect of reducing the increase in diameter in the outer diameter direction is also obtained. In addition, there is a special effect that can further improve the progress of intravascular insertion into a branch lesion, which will be described later.

  If it supplements, the back end side equal diameter large diameter part coil body 31 and the front end side equal diameter small diameter part coil body 32 of the coil body 3 continuously wind the metal wire of the same wire diameter as in the first embodiment. In addition to forming the coil body 3 by revolving, as shown in FIG. 6 (a), the coil bodies 31, 32 at the front end portion of the coil body 31 and the rear end portion of the coil body 32 are brazed, Alternatively, the joining member 4 such as solder may be melted and fixed to provide the intermediate joint portion 42, or may be ground into a tapered shape as shown in the figure, and an annular shape as shown in the figure (b) A spacer 421 may be interposed between the front end portion of the coil body 31 and the rear end portion of the coil body 32, and the joining member 4 may be melted and fixed to provide an intermediate fixing portion 42. Also, as shown in FIG. May be ground into a shape, and further as shown in the figure (c) The outer diameter of the distal end portion of the yl body 31 may be provided intermediate joint 42 rear end portion and the joining member 4 after screwing by melting fixation of the coil body 32 by small diameter.

Next, a treatment example will be described in which the guide body 1 of the present invention is used to push the inside of the blood vessel while the coil body 3 at the distal end is bent in a U shape before reaching the stenotic lesion.
FIG. 7 shows a progress state diagram of the guide wire 1 to the stenotic lesion in the treatment of the vascular stenosis lesion of the lower limb. For example, in order to quickly reach the obstruction lesion 9C of the anterior tibial artery 9B, In the generally straight superficial femoral artery 9A with little bending meandering, the distal end portion of the guide wire 1 is bent in a U shape (reference symbol (B) in the drawing) to the branch portion 9D while being bent. The guide wire 1 is then guided to the occluded lesioned part 9C after it is pulled to the proximal side once to make the tip part straight (symbol S1). (Code S2)

In such a case, the distal end side equal diameter small diameter coil body 32 of the guide wire 1 of the present invention changes the total length of the spring constant increase resulting from the coil average diameter difference from the rear end side equal diameter large diameter section coil body 31. Without increasing the number of turns by reducing the coil pitch without reducing the coil pitch, it is easy to be deformed into a U shape without damaging the blood vessel wall while maintaining flexibility while being thin, and If it is U-shaped, unlike the straight shape, the surface pressure with the blood vessel wall will be low, it can be quickly guided to the desired position without damaging the blood vessel wall, and it will be straight without bending at the branch portion 9D. Can be restored.
In addition, by filling the coil body 3 of the second embodiment with the elastic bodies 81 and 82 having a certain mechanical characteristic, the resilience of returning to a straight shape can be further improved by eliminating the bending wrinkles. Further, by providing the sealed chamber 83 sealed in the distal end side equal diameter small diameter coil body 32 of the third embodiment, there is a special effect that can further enhance the restoring force to return to the straight shape. is there.

Next, an assembly using the guide wire 1 of the present invention will be described.
According to the present invention, even if a coil average diameter difference is generated in the coil body 3 having a small diameter on the front end side and a large diameter on the rear end side, a spring constant fluctuation caused by the coil average diameter difference is suppressed to ensure flexibility of the front end portion. On the other hand, it is possible to obtain a guide wire 1 for cardiovascular treatment and for lower limb blood vessel treatment with improved recovery characteristics from U-shaped deformation to a straight shape.
For example, as the guide wire 1 for cardiovascular treatment, the outer diameter of the core wire proximal portion 22 and the outer diameter D _{1 of the} rear end side equal diameter large diameter portion coil body 31 are 0.3048 mm to 0.3556 mm (0.012 inch). The outer diameter D ₂ of the coil body 32 having the same diameter on the tip side is 0.2286 mm to 0.3048 mm (0.009 inch to 0.012 inch), and the tip side diameter is reduced. be able to.
Then, the guide wire 1 is inserted into the microcatheter 10, and the guide wire 1 and the microcatheter 10 are inserted into the guiding catheter 11. In such a case, the guiding catheter 11 uses 6F (inner diameter 2.3 mm to 2.7 mm to inner diameter 1.91 mm to 2.00 mm), and the inner diameter of the microcatheter 10 inserted therein is 0.28 mm to 0.2 mm. 90 mm.

  Also, the lower limb vascular treatment guide wire 1 has a blood vessel diameter that is approximately 2 to 5 times larger than the cardiovascular diameter and a stenotic lesion length that is three times or longer. A forward force that pushes forward more strongly than the guide wire for the coil is required, and the outer diameter D 1 of the coil body 3 having the same diameter and small diameter portion 32 is the same as that of the guide wire 1 for cardiovascular treatment. The outer diameter D 1 of the rear-end-side equal-diameter large-diameter portion coil body 31 is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch) to increase the rigidity. In order to increase the advancing force that strongly pushes against both the guide wires 1 for the cardiovascular treatment and the lower limb vascular treatment, a reaction force that supports the advancing force is required.

And as the microcatheter 10 that exhibits the reaction force that supports this strong advancing force, in addition to a multilayer resin tube (inner layer PTFE, outer layer polyamide, etc.) structure, and a structure in which a braid of metal wire is interposed in the multilayer resin tube, In particular, a spiral tube body in which a tip portion 10B having a substantially conical shape made of a metal or a synthetic resin is fixed and a round wire of a plurality of fine metal wires is formed into a multi-row coil body is desirable.
Furthermore, in the case of cardiovascular treatment procedures, the vessel diameter is small and the meandering is severe, and in the case of lower limb vessel treatment procedures, the vessel diameter is thick but stenosis or completely occluded lesion length is longer than that of cardiovascular. In order to perforate the closed portion with the guide wire 1 in a length of 3 to 5 times longer, the outer periphery made of a metal wire having a tensile breaking strength of 200 kgf / mm ² or more such as a stainless steel wire or a tungsten wire. More preferably, the spiral tube body of a multi-strand coil body in which the portion forms a rounded irregular shape is shown. FIG. 8 shows that, among the multi-strands, for example, the strand diameter is 0.11 mm. 1 to 2 thick wires 10C having a diameter of 0.18 mm and 2 to 8 wires 10D having a wire diameter of 0.06 mm to 0.10 mm are wound or twisted, or one thick wire From two thin wires This one set as two or more sets arranged winding each metal wire by adjacent contact or stranding and outer peripheral portion with a hollow shape has the structure of the corrugated spiral strip tube 10A.
This is because the blood vessel wall and the convex and concave portions of the outer peripheral portion of the multi-strip line are in contact with each other to prevent sliding movement, and the force that supports the reaction force of the guide wire 1 to be pushed forward is high. In addition, the thick wire contacts the blood vessel wall earlier, and if it is rotated once in that state, it moves only with the twisted pitch of the thick wire, and the travel distance in one rotation becomes longer. As a result, the guide wire 1 This is because the advancing / retreating operation as an assembly including the is accelerated. In addition, the structure which forms the said uneven shape in the front-end | tip part of an outer peripheral part, or the whole, or the said unevenness in at least one part (within 300 mm from a front-end | tip) by the compression / pressing action from the blood vessel wall at the time of stenosis part intravascular insertion If it is the structure which forms a shape, the structure which provided the thin resin tube body 10E in the outer peripheral part and the same resin tube body 10F inside may be sufficient.

Also, in an assembly with a balloon catheter or the like in the procedure of a vascular bifurcation lesion, the balloon portion of the balloon catheter is expanded in front of each lesion of the vascular bifurcation lesion and brought into contact with the blood vessel wall to advance. By supporting the reaction force of the guide wire 1 to be exerted, a propulsive force forward of the guide wire 1 is exerted, and the guide wire 1 and a balloon catheter (not shown) are inserted into the guiding catheter 11 as a pair. Thus, the kissing procedure can be easily performed. The kissing technique referred to here is a guide wire and a balloon catheter that are inserted into two sets of guiding catheters 11 as a set to simultaneously expand the balloon portions of the two balloon catheters in the bifurcation lesion of the blood vessel, This refers to a technique that simultaneously expands the blood vessel inner diameter of two branching stenotic lesions.
As an assembly in such a case, the outer diameter D ₂ of the coil body 32 having the same diameter on the distal end side of the guide wire 1 is 0.2286 mm to 0.3048 mm (0.009 inch to 0.012 inch) and the rear end side. The outer diameter D ₁ of the equal-diameter large-diameter portion coil body 31 is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch), and the guide wire 1 is a balloon having an inner diameter of 0.28 mm to 0.90 mm. Insert into the catheter to make one set, and insert the guide wire and the balloon catheter into two sets into the guiding catheter having an inner diameter of 1.91 mm to 2.67 mm to facilitate the kissing procedure. It is the assembly characterized by doing.

(The invention's effect)
As described above, in the guide wire of the present invention, the coil body attached to the tip is considered as a “torsion coil spring body”, and the coil average diameter difference (or the coil body having an equal diameter large diameter portion and an equal diameter small diameter portion) (or Suppressing the increased fluctuation of the spring constant caused by the difference in outer diameter), it is possible to enable soft touch without drilling the blood vessel wall while the outer diameter is small, and the spring index and the bending stress correction coefficient Therefore, the present invention provides a medical guide wire or the like having a new technical idea that can improve the fatigue resistance characteristics of repeated torsional rotation of a coil body. There are the above various effects.

1 Medical guide wire (guide wire)
2 Core wire 21 Core wire tip 22 Core wire hand 3 Coil spring body (coil body)
DESCRIPTION OF SYMBOLS 31 Rear end side equal diameter large diameter part coil body 32 Front end side equal diameter small diameter part coil body 5 Lead plug 6 Resin coating 7 Hydrophilic coating 8 Elastic body 81 Rear end side elastic body 82 Front end side elastic body 9 Lesion wall restraint part 10 Microcatheter 11 Guiding catheter

Claims (8)

A medical guide wire in which a core wire composed of a flexible elongated body, a coil spring body having the core wire inserted through the distal end portion of the core wire, and a leading plug formed in the distal end portion of the core wire and the coil spring body In
The coil spring body is formed by winding a metal wire having the same wire diameter to form a rear end side equal diameter large diameter coil body and a front end side equal diameter small diameter coil body from the proximal side to the front end portion. Consisting of
The coil average diameter of the rear end side equal diameter large diameter coil body is D ₀₁ (mm), the coil wire diameter is d (mm), the coil pitch is P ₁ (mm), and the equal diameter length in the longitudinal direction is L _1. (Mm), the spring constant of the torsion coil is k ₁ (kgf / mm),
The coil average diameter of the distal end side equal diameter small diameter coil body is D ₀₂ (mm), the coil wire diameter is d (mm), the coil pitch is P ₂ (mm), and the equal diameter length in the longitudinal direction is L ₂ (mm). ), When the spring constant of the torsion coil is k ₂ (kgf / mm),
The coil pitch P ₂ (mm) of the distal end side equal diameter small diameter coil body is:
D ₀₂ × 2d / (1.1D ₀₂ + 2.1d) ≦ P ₂ ≦ D ₀₂ / D ₀₁ × P ₁
The spring constant ratio k ₂ / k ₁ of the torsion coil is
D ₀₁ × L ₁ × 2d / {L ₂ × (1.1D ₀₂ + 2.1d) × P ₁ } ≦ k ₂ / k ₁ ≦ L ₁ / L ₂ Wire. The coil pitch P ₂ (mm) of the distal end side equal diameter small diameter coil body is:
D ₀₂ × 2d / (D ₀₂ + 2d) ≦ P ₂ ≦ D ₀₂ / D ₀₁ × P ₁ and the torsion coil spring constant ratio k ₂ / k ₁ is
_2. The medical treatment according to claim 1, comprising a relational expression of D ₀₁ × L ₁ × 2d / {L ₂ × (D ₀₂ + 2d) × P ₁ } ≦ k ₂ / k ₁ ≦ L ₁ / L _2. Guide wire. The outer diameter of the rear end side equal diameter large diameter coil body is 0.4572 mm (0.018 inch) or less, and the outer diameter of the rear end side equal diameter large diameter coil body is D ₁ (mm), When the outer diameter of the coil body with the same diameter at the tip side is set to D ₂ (mm),
The medical guidewire according to any one of claims 1-2 which outer diameter ratio D ₁ / D ₂ is characterized in that it is a 2.0 from 1.2. The length in the longitudinal direction of the coil body is 300 mm or less, and the equal-diameter length L ₁ (mm) in the longitudinal direction of the rear-end-side equal-diameter large-diameter portion coil body and the distal-end-side equal-diameter small-diameter portion coil body longitudinal equal diameter length ratio of the length _{L 2 (mm) L 1 /} L 2 is a medical guidewire according to any one of claims 1 to 3, characterized in that 5 the following . When the spring index of the distal end side equal diameter small diameter coil body is C ₂ and the bending stress correction coefficient is kp ₂ , when the spring index C ₂ is 3 or more, the bending stress correction coefficient kp ₂ is 1 The medical guide wire according to any one of claims 1 to 4, wherein the guide wire is .33 or less. In the gap between the core wire and the coil spring body and the gap between the coil wires of the coil spring body, the bending elastic modulus is 600 kgf / cm ² to 6000 kgf / cm ² and the tensile elongation at break is 200%. When the spring index C ₂ is 3 or more when the elastic body of 1000% is filled, and the spring index of the tip side equal diameter small diameter coil body is C ² and the bending stress correction coefficient is kp ₂ , the bending stress correction coefficient kp ₂ is medical guidewire according to any one of claims 1 to 4, characterized in that at 1.33 or less. In the assembly of the medical guidewire according to any one of claims 1 to 6, a microcatheter, and a guiding catheter,
The outer diameter of the rear end side equal diameter large diameter coil body of the medical guide wire is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch), and the distal end side equal diameter small diameter coil body is The outer diameter of the coil body is 0.2286 mm to 0.3048 mm (0.009 inch to 0.012 inch), and the outer diameter of the distal end side equal diameter small diameter coil body is the rear end side equal diameter large diameter coil body. Smaller than the outer diameter,
The medical guide wire has an inner diameter of 0.28 mm to 0.90 mm, and a plurality of thick and thin wires are formed by winding or twisting, and the outer peripheral portion is a convex and concave flexible hollow tube. The medical guide wire and the microcatheter are inserted into a guiding catheter having an inner diameter of 1.91 mm to 2.67 mm. Assembly of wire, microcatheter and guiding catheter. In the assembly of the medical guidewire according to any one of claims 1 to 6, a balloon catheter, and a guiding catheter,
The outer diameter of the rear end side equal diameter large diameter coil body of the medical guide wire is 0.3048 mm to 0.4572 mm (0.012 inch to 0.018 inch), and the distal end side equal diameter small diameter coil body is The outer diameter of the coil body is 0.2286 mm to 0.3048 mm (0.009 inch to 0.012 inch), and the outer diameter of the distal end side equal diameter small diameter coil body is the rear end side equal diameter large diameter coil body. Smaller than the outer diameter,
The medical guide wire is inserted into the balloon catheter having an inner diameter of 0.28 mm to 0.90 mm to form a pair, and the medical guide wire is inserted into the guiding catheter having an inner diameter of 1.91 mm to 2.67 mm. An assembly of a medical guide wire, a balloon catheter, and a guiding catheter, wherein two sets including a wire and the balloon catheter are inserted to facilitate a kissing procedure.

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