GUIDE WIRE

A guide wire is disclosed, which includes a core portion formed of an elongated object having flexibility, in which the core portion includes a main body portion formed on a proximal side, a flat plate portion formed on a distal side, and a transition portion which connects the main body portion and the flat plate portion, and in which at least one groove portion extending in a direction different from a length direction is formed on a slope of the transition portion in the length direction. In addition, the guide wire includes a coil portion disposed so as to cover the distal side of the core portion.

TECHNICAL FIELD

The present disclosure relates to a guide wire used when guiding a catheter into a lumen in a living body, in particular, a blood vessel.

BACKGROUND DISCUSSION

The guidewire is used when guiding a catheter which is used for treatment of a site in which it is difficult to perform a surgical operation, for example, percutaneous transluminal coronary angioplasty (PTCA) or treatment which is aimed to be less invasive to the human body, or used in tests such as cardioangiography, into a blood vessel. PTCA is a treatment method for dilating a stenosed site of a coronary artery with a balloon to secure a blood flow path.

In PTCA, a balloon catheter is guided to a stenosed site by inserting a guide wire into the vicinity of the stenosed site of a blood vessel in a state in which a distal portion of the guide wire protrudes from a distal portion of the balloon catheter. At that time, it is necessary for the guide wire to select and pass through a meandering or bifurcated blood vessel, or a stenosed blood vessel. In addition, it is necessary to widen or penetrate deposits such as cholesterol constituting the stenosed site using a pushing force of the guide wire in the stenosed site. Accordingly, flexibility (blood vessel followability) for following the shape of a blood vessel and for preventing damage to a blood vessel wall, and excellent pushing performance (pushability) which can help ensure effective transmission of a pushing force from the operator's hand side (proximal portion) to a distal portion are required for the guide wire used for PTCA.

In addition, in PTCA, in some cases, reshaping at a distal end is performed before inserting the guide wire into the blood vessel in order to make the guide wire follow the bent and bifurcated blood vessel. Specifically, for example, a surgeon can perform the reshaping by bending the distal portion of the guide wire into a predetermined shape (for example, J shape) using fingers in accordance with the shape of the bifurcated blood vessel or the like. Accordingly, it can be necessary for the guide wire to easily perform such reshaping at a distal end.

In the related art, a guide wire including the following configuration has been proposed in International Publication No. WO/2009/126656 for PTCA. The guide wire in International Publication No. WO/2009/126656 includes a core portion formed of an elongated object; and a coil, which is provided so as to cover a distal side of the core portion. The core portion has a flat plate portion, which is formed to have a plate width equal to or more than twice the plate height (plate thickness), on the distal side.

In the guide wire of International Publication No. WO/2009/126656, the distal portion of the guide wire becomes flexible because a flat plate portion with a thin plate thickness is provided on the distal side of the core portion, which is expected to improve safety and blood vessel followability to some degree. However, the guide wire in International Publication No. WO/2009/126656 includes a round rod-like main body portion which is formed on a proximal side and has a circular shape in transverse cross section; a flat plate portion which is formed on a distal side and has a rectangular shape in transverse cross section; and a transition portion which connects the main body portion and the flat plate portion. Accordingly, in the guide wire of International Publication No. WO/2009/126656, the transverse cross sectional shape greatly changes from the transition portion over the flat plate portion. Therefore, the physical properties (in particular, for example rigidity) also greatly change from the transition portion over the flat plate portion.

In such a guide wire, when the proximal portion of the guide wire is rotated in order to make the guide wire pass a meandering or bifurcated blood vessel, the flat plate portion is twisted or is buckled in the vicinity of a boundary between the transition portion and the flat plate portion. As a result, rotary torque at the proximal portion of the guide wire is not effectively transmitted from the proximal portion to the distal portion. Therefore, the distal portion of the guide wire does not face an intended direction and blood vessel followability of the guide wire is decreased. In addition, torquability is decreased due to twisting of the flat plate portion when the proximal portion of the guide wire is rotated in order to advance the guide wire in a stenosed site, or that pushability and trackability (properties of transmitting a rotational force, which is applied to the guide wire at the proximal portion, to the distal portion) of the guide wire without effective transmission of a pushing force of the proximal portion of the guide wire to the distal portion due to buckling of the flat plate portion in the vicinity of a boundary between the transition portion and the flat plate portion.

SUMMARY

In accordance with an exemplary embodiment, a guide wire is disclosed having excellent blood vessel followability, pushability, and trackability.

A guide wire is disclosed, which includes a core portion formed of an elongated object having flexibility, in which the core portion includes a main body portion formed on a proximal side, a flat plate portion formed on a distal side, and a transition portion which connects the main body portion and the flat plate portion, and in which at least one groove portion extending in a direction different from a length direction is formed on a slope of the transition portion in the length direction.

In addition, it can be preferable that the guide wire according to the present disclosure includes a coil portion which is disposed so as to cover the distal side of the core portion and is obtained by forming strands in a spiral shape, and the core portion and the coil portion are fixed to each other on the distal side. In addition, it can be preferable that the guide wire according to the present disclosure includes a resin covering portion which is formed so as to cover the distal side (or portion) of the core portion and is made of a resin material.

According to the configuration, a portion with a thin plate thickness is disposed on the distal side of the guide wire because the flat plate portion is provided on the distal side of the core portion. Therefore, rigidity at a distal portion of the guide wire is decreased and flexibility of the guide wire at the distal portion is improved. In addition, since the rigidity at the distal portion of the guide wire is decreased, reshaping of the distal portion of the guide wire can be easily performed in accordance with the shape of, for example, a bifurcated blood vessel. In addition, significant change in the transverse cross sectional shape and significant change in the rigidity from the transition portion over the flat plate portion can be prevented because at least one groove portion is formed in the transition portion, which connects the main body portion and the flat plate portion of the core portion. Accordingly, twisting of the flat plate portion or buckling in the vicinity of a boundary between the transition portion and the flat plate portion can be suppressed when the guide wire passes a meandering or bifurcated blood vessel or when the guide wire advances in a stenosed site. As a result, rotary torque of a proximal portion of the guide wire can be effectively transmitted to the distal portion, and therefore, the distal portion of the guide wire can face an intended direction. In addition, pushing force of the proximal portion of the guide wire can be effectively transmitted to the distal portion of the guide wire.

In addition, in the guide wire according to the present disclosure, it can be preferable that at least one groove portion extending in the direction different from the length direction is formed on at least an upper surface or a lower surface of the flat plate portion in the length direction.

According to the configuration, the rigidity of the flat plate portion is further decreased because the groove portion is formed in the flat plate portion. Therefore, the rigidity at the distal portion of the guide wire at which the flat plate portion is disposed is decreased and the flexibility of the guide wire at the distal portion can be further improved.

According to the guide wire of the present disclosure, the flexibility of the guide wire on the distal side is improved and the change in the rigidity of a distal flexible portion is decreased. Therefore, blood vessel followability of the guide wire can be improved. In addition, since the buckling of the core portion can be suppressed, rotary torque or pushing force at the proximal portion of the guide wire can be effectively transmitted to the distal portion. Therefore, blood vessel followability, pushability, and trackability of the guide wire can be improved.

A guide wire is disclosed formed of an elongated object having flexibility, the guide wire comprising: a main body portion formed on a proximal side, the main body portion has a large-diameter portion having a constant outer diameter from a proximal side to a distal side, a first tapered portion of which an outer diameter is decreased toward the distal side, a middle-diameter portion having a constant outer diameter, a second tapered portion of which an outer diameter is decreased toward the distal side; and a small-diameter portion having a constant outer diameter; a flat plate portion formed on a distal side, the flat plate portion having at least one groove portion extending in a direction different from a length direction of the flat plate portion on at least an upper surface or a lower surface of the flat plate portion in the length direction of flat plate portion; and a transition portion which connects the main body portion and the flat plate portion, the transition portion having at least one groove portion extending in a direction different from a length direction of the transition portion on a slope of the transition portion in the length direction of the transition portion.

A guide wire is disclosed, the guide wire comprising: a core portion formed of an elongated object having flexibility, wherein the core portion includes a main body portion formed on a proximal side, a flat plate portion formed on a distal side, and a transition portion which connects the main body portion and the flat plate portion, and at least one groove portion extending orthogonal to a length direction of the transition portion on a slope of the transition portion.

DETAILED DESCRIPTION

A first exemplary embodiment of a guide wire according to the present disclosure will be described in detail while referring to drawings. Note that, in the present disclosure, a distal side refers to a side on which a guide wire is inserted into a blood vessel, and a proximal side refers to a side on which, for example, a surgeon operates the guide wire.

As shown inFIG. 1, a guide wire (hereinafter, referred to as a wire)1is an elongated object including a core portion2A which can include a main body portion3, a transition portion4, and a flat plate portion5. Groove portions41and42are formed in the transition portion4. The total length of the wire1is not particularly limited, and is preferably, for example, 200 mm to 5000 mm. In addition, it can be preferable that the wire1includes a coil portion6disposed so as to cover a distal side (or portion) of the core portion2A, and in which the core portion2A and the coil portion6are fixed to each other on the distal side (or portion). As the fixing method, a fixation material (fixation portion)72such as solder (brazing material) or an adhesive material is preferably used for the fixing, and the fixation portion72may be formed through welding. Hereinafter, each configuration will be described.

As shown inFIGS. 1 to 3, the core portion2A is formed of an elongated object having flexibility. The core portion2A is preferably made of an elastic metal material such as Ni—Ti alloy or stainless steel in consideration of the flexibility and the strength of the wire1. The core portion2A sequentially includes the main body portion3, the transition portion4, and the flat plate portion5from a proximal side to the distal side, and at least one of the groove portion41or the groove portion42is formed in the transition portion4. Note that the groove portion42may not be formed.

As shown inFIGS. 1 to 3, the main body portion3is formed of an elongated object with a bar shape (non-plate shape). In accordance with an exemplary embodiment, it can be preferable that the transverse cross sectional shape (which is a YZ-axis plane and a cross section perpendicular to a length direction) of the main body portion3is substantially a circular shape (refer toFIG. 4). In addition, it can be preferable that the main body portion3includes a large-diameter portion31having a constant outer diameter from the proximal side to the distal side; a first tapered portion32of which the outer diameter is decreased toward the distal side; a middle-diameter portion33having a constant outer diameter, a second tapered portion34of which the outer diameter is decreased toward the distal side; and a small-diameter portion35having a constant outer diameter.

Two tapered portions of the first tapered portion32and the second tapered portion34are described above as tapered portions formed between portions (between the large-diameter portion31and the middle-diameter portion33, and between the middle-diameter portion33and the small-diameter portion35) which have a constant diameter. However, the number of the tapered portions is not limited to two, and at least one tapered portion may be formed. In addition, a large-diameter portion36which has the same outer diameter as that of the large-diameter portion31and has a constituent material different from that of the large-diameter portion31may be joined to the large-diameter portion31in a joint portion (welded portion)37. The joining method is not particularly limited, but examples thereof include butt resistance welding such as friction pressure welding, spot welding using a laser, or upset welding, and joining using a tubular joint member.

As shown inFIGS. 1 to 3, the flat plate portion5provides flexibility to the wire1(core portion2A) and is formed of an elongated plate-shaped flat plate having a rectangular shape in transverse cross section (refer toFIG. 5) so as to facilitate reshaping of a distal portion of the wire at the distal end. The flat plate portion5preferably has, for example, a plate length of 1 mm to 30 mm, a plate width of 0.1 mm to 0.5 mm, and a plate width of 0.01 mm to 0.06 mm. In addition, the plate width of the flat plate portion5may be increased or decreased toward the distal side, and the plate thickness may also be increased or decreased toward the distal side.

In addition, the distal side of the flat plate portion5can be fixed to the coil portion6using the fixation material (fixation portion)72. In addition, the flat plate portion5can be preferably produced together with the transition portion4to be described below by pressing the distal side of the bar-shaped main body portion3, preferably the distal side of which the diameter is reduced, using, for example, a mold. Note that since the transverse cross sectional shape of the flat plate portion5can be produced through the pressing, both ends of the flat plate portion5can be slightly rounded and have an approximately rectangular shape in transverse cross section. However, the roundness of the both ends are omitted inFIG. 5for the convenience of description.

As shown inFIGS. 2 and 3, the transition portion4is a portion which connects the main body portion3and the flat plate portion5and which is gradually changed from a circular shape in transverse cross section (refer toFIG. 4) to the rectangular shape in transverse cross section (refer toFIG. 5) from the proximal side toward the distal side. The length of the transition portion4, for example, is preferably 1 mm to 10 mm. In addition, the transition portion4has four slopes (edges)4a,4b,4c, and4d, which are connected to surfaces of the flat plate portion5. At least one of the groove portion41or the groove portion42extending in a direction different from the length direction can be formed on at least one slope in the length direction. Note that the groove portion42may not be formed. The groove portions41and42are preferably produced by pressing a mold having a surface of a mold, in which convex portions with a shape similar to the groove portions41and42are formed, on the slope of the transition portion4.

As shown inFIGS. 2 and 3, the groove portion41is formed on the slope4aon the same surface side as an upper surface5aof the flat plate portion5. Note that, although not shown in the drawing, the groove portion41may be formed on the slope4bor the slopes4cand4don the same surface sides as a lower surface5bor side surfaces5cand5dof the flat plate portion5. Although not shown in the drawing, the groove portion41may be continuously formed on at least two slopes out of peripheral surfaces consisting of the slope4ato the slope4d.

The direction in which the groove portion41is formed is not particularly limited, but is preferably a direction orthogonal to the length direction as shown inFIG. 3. Note that, although not shown in the drawing, the groove portion41may be formed in a direction inclined to the direction orthogonal to the length direction at a predetermined angle. Furthermore, the planar shape of the groove portion41is preferably a linear shape as shown inFIG. 3, but may be a polygonal line shape or a curved shape.

In accordance with an exemplary embodiment, it is preferable that the transverse cross sectional shape of the groove portion41formed in the transition portion4is an approximately semi-circular shape. However, the transverse cross sectional shape of the groove portion41may be other shapes, for example, an approximately U-shape, an approximately V-shape, or an approximately rectangular shape. The number of groove portions41is preferably, for example, 1 to 100. The groove width W1of the groove portion41is preferably, for example, 0.001 mm to 3 mm. The groove depth D1of the groove portion41is preferably, for example, 0.005 mm to 0.05 mm. In addition, in a case of forming a plurality of groove portions41, the groove width W1is preferably formed to be constant, but may be formed so as to be increased or decreased toward the distal side. The groove depth D1is also preferably formed to be constant, but may be formed so as to be increased or decreased toward the distal side.

An interval T1of adjacent groove portions41is preferably, for example, 0.005 mm to 3 mm. The plurality of groove portions41are preferably formed at even (or equal) intervals, but may be formed so that the interval T1increases or decreases toward the distal side. In addition, the plurality of groove portions41may have an interval T1of, for example, 0 mm, that is, may be continuously formed. Furthermore, the groove portions41which have been continuously formed may be formed in a part or all of the slopes4a,4b,4c, and4dof the transition portion4.

As shown inFIGS. 2 and 3, in the transition portion4, it is preferable that the groove portion41is formed on the slope4aand the groove portion42is formed on the slope4bon the same surface side as the lower surface5bof the flat plate portion5. In addition, it is preferable that the groove portion41and the groove portion42are mutually alternately disposed in the length direction of the transition portion4. However, the groove portion41and the groove portion42may be disposed at the same position as each other. In addition, although not shown in the drawing, in a case where the groove portion41is formed on the slope4b, the groove portion42is formed on the slope4a. In addition, although not shown in the drawing, in a case where the groove portion41is formed on one of the slopes4cand4d, the groove portion42is formed on one of the slopes4dor4c, which is on a side opposite to the slope on which the groove portion41is formed.

Although not shown in the drawing, in a case where the groove portions41are continuously formed on at least two slopes on the peripheral surface consisting of the slopes4ato4d, the groove portions42may be disposed and formed alternately with the groove portion41on slopes on which the groove portion41has not been formed.

The formation direction, the planar shape, the transverse cross-sectional shape, the number of grooves, the groove width, and the groove depth of the groove portion42, and the interval between adjacent groove portions42are the same as those of the groove portion41, and therefore, the description thereof will not be repeated. In addition, the formation direction of the groove portion42is preferably the same as that of the groove portion41, but may be different from that of the groove portion41.

Although not shown in the drawing, in a case where a plurality of groove portions41are formed, other groove portions which communicate with two or more arbitrary groove portions41in the length direction of the transition portion4may be formed. In addition, even in a case where a plurality of groove portions42are formed, other groove portions which communicate with two or more arbitrary groove portions42in the length direction of the transition portion4may also be formed.

In the wire1of the present disclosure, forming of the groove portions41and42suppresses great change in the transverse cross sectional shape from the transition portion4over the flat plate portion5, and therefore, relatively large change in the rigidity can also be suppressed. As a result, there is no case where the flat plate portion5is twisted when using the wire1or is buckled in the vicinity of a boundary between the transition portion4and the flat plate portion5. Therefore, rotary torque of the main body portion3is effectively transmitted to the flat plate portion5. Accordingly, the distal portion of the wire1can face in the intended direction. In addition, a pushing force of the main body portion3is effectively transmitted to the flat plate portion5. As a result, excellent blood vessel followability, pushability, and trackability of the wire1can be improved.

As shown inFIG. 1, the coil portion6is a coil which is disposed so as to cover the distal side of the core portion2A and is obtained by forming strands in a spiral shape. The coil may be either a so-called densely wound coil in which adjacent strands are in contact with each other or a coil in which adjacent strands are separated from each other. In addition, the distal side of the coil portion6can be fixed to the core portion2A (flat plate portion5) using the fixation material (fixation portion)72.

The materials constituting the strands are not particularly limited, but are preferably metal materials such as stainless steel or Pt—Ni alloy. In addition, the size of the coil portion6is not particularly limited, and varies depending on use purpose of the wire1. In the wire1used for PTCA, it is preferable that the coil outer diameter of the coil portion6is, for example, 0.2 mm to 0.5 mm and the coil length is 10 mm to 1000 mm. The coil outer diameter is preferably constant in the length direction of the wire1, but may be decreased toward the distal side of the wire1.

The coil portion6may be obtained by combining two or more metal materials. For example, the coil portion6may include a first coil portion61formed of stainless steel strands on the proximal side; and a second coil portion62formed of Pt—Ni alloy strands as radiopaque materials on the distal side, and both coil portions61and62may be joined through welding or adhering in a boundary portion63between the first coil portion61and the second coil portion62. Accordingly, it can be relatively easy for the distal side of the wire1to be visually checked under X-ray fluoroscopy.

Next, a modification example of the first embodiment of the wire1of the present disclosure will be described.

As shown inFIG. 1, in the wire1, it is sufficient for the core portion2A and the coil portion6to be fixed to each other in one site on the distal side, but the core portion2A and the coil portion6are preferably fixed to each other in a plurality of sites.

For example, as shown inFIG. 1, in the wire1, the distal side of the core portion2A (flat plate portion5) and the distal side of the coil portion6(second coil portion62) are fixed to each other using the fixation material (fixation portion)72; a site (the proximal side of the transition portion4, the small-diameter portion35, and the distal side of the second tapered portion34) in the middle of the core portion2A and a site (boundary portion63) in the middle of the coil portion6are fixed to each other using a fixation material (fixation portion)73; and a site (the proximal side of the middle-diameter portion33and the distal side of the first tapered portion32) in the middle of the core portion2A and the proximal side of the coil portion6(first coil portion61) are fixed to each other using a fixation material (fixation portion)71.

Here, the fixation materials (fixation portions)71,72, and73can be solder (brazing materials) or adhesives. Note that, in the fixation method of the core portion2A and the coil portion6, it is not limited to use the fixation materials71,72, and73, and the fixation portions71,72, and73may be formed through welding.

As shown inFIG. 1, the wire1preferably includes a resin covering portion8which is formed so as to cover at least the surface of the coil portion6on the distal side (or portion).

Specifically, the resin covering portion8preferably covers a part of the surface of the wire or the entirety of the surface of the wire, that is, the entire surface of the second coil portion62, the entire surface of the coil portion6(the first coil portion61, the boundary portion63, and the second coil portion62), or the entire surface of a site on the proximal side of the coil portion6and the core portion2A.

The resin covering portion8is preferably made of resin materials such as a fluorine resin, a maleic anhydride polymeric material, and polyurethane. In addition, the thickness of the resin covering portion8is preferably, for example, 0.001 mm to 0.05 mm. Since the wire1is covered by such a resin covering portion8, the frictional resistance (sliding resistance) of the wire1is decreased, and the operability in a blood vessel is improved.

Next, a second embodiment of a guide wire according to the present disclosure will be described.

In the guide wire, a core portion2B (refer toFIGS. 6 and 7) is used instead of the core portion2A (refer toFIG. 1) of the first embodiment. Therefore, at least one of a groove portion51or a groove portion52extending in a direction different from a length direction is formed in a flat plate portion5in the length direction in addition to forming the groove portion41or the groove portion41and the groove portion42in the transition portion4. In addition, the groove portion52may not be formed. The groove portions51and52are preferably formed by pressing a mold having a surface of a mold, in which convex portions with a shape similar to the groove portions51and52are formed, on the surface of the flat plate portion5. Note that the configuration of the second embodiment other than the groove portions51and52are the same as described above, and therefore, only the groove portions51and52will be described and the description of other portions will not be repeated.

As shown inFIGS. 6 and 7, the groove portion51is formed on an upper surface5aof the flat plate portion5. Note that, although not shown in the drawing, the groove portion51may be formed on a lower surface5bof the flat plate portion5. Here, the upper surface5aand the lower surface5bare surfaces, which become an inner peripheral surface and an outer peripheral surface when a distal portion of the wire is curved. In addition, the direction in which the groove portion51is formed is not particularly limited, but is preferably a plate width direction (a direction orthogonal to the length direction) as shown inFIG. 7. Note that, although not shown in the drawing, the groove portion51may be formed in an oblique line shape in a direction inclined to the plate width direction at a predetermined angle. Since the oblique line-shaped groove portion51is formed in this manner, transmission of rotary torque from a proximal side to a distal side varies depending on the rotational direction of the wire1(core portion2B), and the rotary torque can be relatively easily transmitted in the rotational direction opposite to the inclination direction of the oblique line-shaped groove portion51. As a result, the blood vessel followability of the wire1is further improved. Furthermore, the planar shape of the groove portion51is preferably a linear shape as shown inFIG. 7, but may be a polygonal line shape or a curved shape.

It is preferable that the transverse cross sectional shape of the groove portion51formed in the flat plate portion5is an approximately semi-circular shape. However, the transverse cross sectional shape of the groove portion51may be other shapes, for example, an approximately U-shape, an approximately V-shape, or an approximately rectangular shape. The number of groove portions51is preferably, for example, 1 to 500. The groove width W2of the groove portion51is preferably, for example, 0.06 mm to 0.5 mm. The groove depth D2of the groove portion51is preferably, for example, 0.001 mm to 0.03 mm. In addition, in a case of forming a plurality of groove portions51, the groove width W2is preferably formed to be constant, but may be formed so as to be increased or decreased toward the distal side. The groove depth D2is also preferably formed to be constant, but may be formed so as to be increased or decreased toward the distal side.

An interval T2of adjacent groove portions51is preferably, for example, 0.1 mm to 2 mm. The plurality of groove portions51are preferably formed at even intervals, but may be formed so that the interval T2increases or decreases toward the distal side. In addition, the plurality of groove portions51may have an interval T2of, for example, 0 mm, that is, may be continuously formed. Furthermore, the groove portions51, which have been continuously formed, may be formed in a part or all of the upper surface5aor the lower surface5bof the flat plate portion5.

As shown inFIGS. 6 and 7, in the flat plate portion5, it is preferable that the groove portion51is formed on the upper surface5aand the groove portion52is formed on the lower surface5bof the flat plate portion5. In addition, it is preferable that the groove portion51and the groove portion52are mutually alternately disposed in the length direction of the flat plate portion5. However, the groove portion51and the groove portion52may be disposed at the same position as each other. In addition, although not shown in the drawing, in a case where the groove portion51is formed on the lower surface5b, the groove portion52is formed on the upper surface5a.

The formation direction, the planar shape, the transverse cross-sectional shape, the number of grooves, the groove width, and the groove depth of the groove portion52, and the interval between adjacent groove portions52are the same as those of the groove portion51, and therefore, the description thereof will not be repeated. In addition, the formation direction or the like of the groove portion52is preferably the same as that of the groove portion51, but may be different from that of the groove portion51.

Although not shown in the drawing, in a case where a plurality of groove portions51are formed, other groove portions which communicate with two or more arbitrary groove portions51in the length direction of the flat plate portion5may be formed. In addition, even in a case where a plurality of groove portions52are formed, other groove portions which communicate with two or more arbitrary groove portions52in the length direction of the flat plate portion5may also be formed.

In the guide wire of the present disclosure, the rigidity of the flat plate portion5is further decreased by forming the groove portions51and52. Therefore, the flexibility of the distal portion of the guide wire is further improved and the risk of perforating a blood vessel can be reduced. Thus, the safety is improved. Accordingly, the blood vessel followability of the guide wire is further improved.

Modification examples of the second exemplary embodiment of the guide wire of the present disclosure can include an example in which the core portion2B and the coil portion6are fixed to each other in a plurality of sites and an example in which the surface of the wire is covered with the resin covering portion8, similarly to the first exemplary embodiment.

Next, a third exemplary embodiment of a guide wire of the present disclosure will be described.

As shown inFIG. 8, a guide wire1can include a resin covering portion9instead of the coil portion6in the first embodiment which includes the core portion2A. In addition, although not shown in the drawing, the guide wire1may include the resin covering portion9instead of the coil portion6in the second embodiment which includes the core portion2B (refer toFIG. 6).

Note that the configuration of the third exemplary embodiment other than the resin covering portion9is the same as described above. Therefore, only the resin covering portion9will be described and the description of other portions will not be repeated.

In accordance with an exemplary embodiment, the resin covering portion9is formed so as to cover a distal side of the core portion2A or the core portion2B and is made of a resin material. Examples of the resin material include a fluorine resin or polyurethane, and polyurethane is preferable. It is preferable that the resin covering portion9is formed such that the thickness of the resin covering portion9on the distal side is thicker than that on the proximal side. In accordance with an exemplary embodiment, the thickness of the resin covering portion9is preferably, for example, 10 μm to 400 μm. In addition, the resin covering portion9is preferably formed such that the distal side of the core portion2A is rounded.

Since such a resin covering portion9is provided, the core portion2A or the core portion2B can be prevented from damaging a blood vessel wall when using the guide wire1. Therefore, the safety is improved. In addition, the frictional resistance (sliding resistance) is decreased in the guide wire1, and therefore, the operability within a blood vessel is also improved.

Next, a method for using the guide wire of the present disclosure will be described by taking PTCA for an example.

A distal end of the guide wire is inserted into a femoral artery in a state protruding from a distal end of a guiding catheter, through a Seldinger technique, and is inserted into a right coronary artery via an aorta, an aortic arch, and a right coronary artery orifice. Only the guide wire is made to pass a stenosed site of a blood vessel by being further advanced within the right coronary artery while leaving the guiding catheter at a position of the right coronary artery orifice. Then, the distal end of the guide wire stops at a position beyond the stenosed site of the blood vessel. Accordingly, the passage of a balloon catheter for widening the stenosed site is secured.

Next, a distal end of the balloon catheter, which has been inserted from a proximal side of the guide wire, is made to protrude from the distal end of the guiding catheter, and is inserted into the right coronary artery from the right coronary artery orifice by being further advanced along the guide wire. The distal end of the balloon catheter stops at a position at which a balloon of the balloon catheter reaches a position of the stenosed site of the blood vessel.

Next, the stenosed site of the blood vessel is widened by dilating the balloon after injecting a fluid for dilating a balloon into the balloon catheter from the proximal side thereof. By doing this, deposits such as cholesterol which have been adhered to and deposited in the stenosed site of the blood vessel are physically widened, and therefore, interruption of blood flow is resolved.

The fluid for dilating a balloon is removed from the balloon to deflate the balloon. Next, the balloon catheter, the guide wire, and the guiding catheter are removed from the blood vessel by moving the balloon catheter in the proximal direction along with the guide wire. Accordingly, the procedure of PTCA finishes.

The detailed description above describes a guide wire used when guiding a catheter into a lumen in a living body, in particular, a blood vessel. The invention is not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents can effected by one skilled in the art without departing from the spirit and scope of the invention as defined in the accompanying claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims.