JP6399809B2 - Medical guidewire - Google Patents

Description

  The present invention relates to a medical guide wire for use with a medical catheter.

  The medical guide wire is inserted into the blood vessel prior to the medical catheter, and serves to introduce the subsequent catheter into the blood vessel safely and reliably.

  A medical guide wire is disclosed in Patent Document 1, for example. This medical guide wire (hereinafter simply referred to as a guide wire) is inserted and advanced from a distal end portion into a blood vessel / branch blood vessel or a blood vessel occlusion portion having a complicated and complicated path while rotating a hand portion located outside the body. The "push / pull / rotate" operation is advanced into the blood vessel. For this reason, the leading end portion of the leading portion is highly flexible and excellent in torque transmission, and has a high bending property that can be deformed with a small radius of curvature and excellent maneuverability of the leading end portion by manual operation of the hand portion. High mechanical properties are required.

  In order to satisfy such requirements, generally, a guide wire is configured by a coil body and a linear core member inserted in the coil body, as described in Patent Document 1. . Thereby, while being able to implement | achieve a softness | flexibility and the outstanding operativity by a coil body, the torque transmission property (rigidity) for progressing in the blood vessel by a metal core member is realizable. In practice, the coil body can be smoothly advanced through the blood vessel by the doctor according to the shape of the path of the blood vessel to be inserted before the guide wire is inserted. become.

Japanese Patent No. 2575238

  By the way, although the rigidity and torque transmission property of the coil body are supplemented by the cored bar member, it is difficult to push the coil body in the traveling direction depending on the bending state of the blood vessel or the stenosis.

  The present invention has been made in view of the above points, and provides a medical guide wire with improved pushing force without impairing the flexibility and operability of the coil body.

One aspect of the medical guidewire of the present invention is:
A coil body;
A linear core member inserted in the coil body;
A medical guidewire having:
The metal core member is
At least a portion inserted in the coil body has a coefficient of friction between the cored bar member after coating and the coiled body greater than a coefficient of friction between the cored bar member before coating and the coiled body. while being coated with a coating material comprising,
At least a portion not inserted in the coil body has a coefficient of friction between the cored bar member after coating and the inner wall of the blood vessel smaller than a coefficient of friction between the cored bar member before coating and the inner wall of the blood vessel. Is coated with a coating material .

  According to the present invention, it is possible to realize a medical guide wire with improved pushing force without impairing the flexibility and operability of the coil body.

Schematic which shows the whole structure of the balloon catheter to which the guide wire by embodiment is applied Vertical section of the balloon catheter shaft The longitudinal cross-sectional view which shows the guide wire by embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an overall configuration when a guide wire according to an embodiment of the present invention is applied to a balloon catheter. The balloon catheter 100 includes a hub 110, a balloon 120, a proxy shaft 130, and a distal shaft 140 as main bodies.

  A guide wire insertion port 150 for inserting the guide wire 200 is formed at the boundary between the proxy shaft 130 and the distal shaft 140. The proxy shaft 130 is mainly composed of an outer tube. The distal shaft 140 is mainly composed of an outer tube and an inner tube. Specifically, the proxy shaft 130 has a single tube structure with an outer tube, and the distal shaft 140 has a double tube structure with an outer tube and an inner tube. These configurations will be described in detail later with reference to FIG.

  The hub 110 is placed at the hand of a doctor who operates the balloon catheter 100 in angioplasty. The hub 110 is configured to be connectable to a pressure application device (not shown) such as an indeflator that supplies and discharges fluid by pressure. The proximal shaft 130 is joined to the hub 110 so as to be in fluid communication, and extends distally. Further, a distal shaft 140 is joined to the distal side so as to be in fluid communication. A balloon 120 is joined to the distal side of the distal shaft 140. The proxy shaft 130 and the distal shaft 140 have a flow path for supplying high-pressure fluid into the balloon 120.

  FIG. 2 shows a longitudinal cross-sectional view of the shaft portion of the balloon catheter 100 cut in the longitudinal direction. The proxy shaft 130 is configured by joining an outer tube 132 to a metal tube 131. As a material of the outer tube 132, a polyamide-based resin, a urethane-based resin, or a polyethylene-based resin can be used.

  The distal shaft 140 has a double tube structure in which an inner tube 133 is disposed in a tube of the outer tube 132. The inner tube 133 is for inserting the guide wire 200 (FIG. 1). The inner tube 133 extends from the boundary position between the proximal shaft 130 and the distal shaft 140 to a position further to the distal side than the balloon 120 so as to penetrate the inside of the outer tube 132 and the balloon 120. Thereby, the guide wire 200 inserted from the guide wire insertion port 150 passes through the inner tube 133 and protrudes from the guide wire insertion port 150. As a material for the inner tube 133, a polyamide-based resin, a urethane-based resin, or a polyethylene-based resin can be used similarly to the outer tube 132.

  The proximal end of the balloon 120 is joined to the distal end of the outer tube 132, and the distal end of the balloon 120 surrounds the outer circumferential surface of the inner tube 133 and is joined to the outer circumferential surface thereof. As a result, the high-pressure fluid supplied into the outer tube 132 via the hub 110 (FIG. 1) flows into the balloon 120 through the outer tube 132 and stays in the balloon 120. As a result, the balloon 120 120 expands. The balloon 120 is folded to approximately the same size as the outer diameter of the distal shaft 140 before the high-pressure fluid is supplied to the inside. When the high-pressure fluid is supplied to the inside of the balloon 120, the balloon 120 expands by expanding the fold. 1 and 2 show a state where the balloon 120 is expanded.

  A metal core wire 170 is provided in the outer tube 132. The proximal end of the core wire 170 is joined to the metal tube 131 by welding. The length of the core wire 170 is selected so that the distal end (tip) thereof is positioned in front of the balloon 120 of the distal shaft 140. As can also be seen from the figure, the core wire 170 is disposed in the distal shaft 140 between the inner tube 133 and the outer tube 132, that is, between the outer surface of the inner tube 133 and the inner surface of the outer tube 132. .

  The core wire 170 has a shape that becomes thinner from the proximal end (proximal end) to the distal end (distal end). Thereby, the rigidity in the direction perpendicular to the longitudinal direction of the core wire 170 gradually decreases as it goes from the proximal end (proximal end) to the distal end (distal end). As a result, the balloon catheter 100 can prevent kink and buckling of the catheter without abrupt changes in rigidity at the distal end portion of the metal tube 131 while maintaining the flexibility of the distal end of the catheter.

  The core wire 170 is coated with a coating material. As the coating material, a material in which the friction coefficient between the coated core wire 170 and the outer tube 132 is larger than the friction coefficient between the core wire 170 and the outer tube 132 before coating is used. In the present embodiment, urethane resin or epoxy resin is used as the coating material.

  FIG. 3 is a longitudinal sectional view showing a guide wire 200 according to the present embodiment. In FIG. 3, in order to make the drawing easy to understand, the length direction of the guide wire 200 is shortened and schematically illustrated as a whole, and the overall dimensions are different from actual ones.

  The guide wire 200 includes a coil body 201 and a linear cored bar member 202 inserted into the coil body 201. The cored bar member 202 is reduced in diameter toward the tip. The tip end of the cored bar member 202 and the tip end of the coil body 201 are fixed at the most distal end portion 203. Further, the proximal end portion of the coil body 201 is fixed to the cored bar member 202.

  Moreover, the part inserted in the coil body 201 among the cored bar members 202 is coated with a coating material. As the coating material, a material is used in which the friction coefficient between the cored bar member 202 after coating and the coil body 201 is larger than the friction coefficient between the cored bar member 202 and coil body 201 before coating. Yes. In the present embodiment, urethane resin or epoxy resin is used as the coating material. The coating material is not limited to this, and a polyether block amide copolymer or the like may be used. The coating material is preferably a polymer in view of ease of coating and durability.

  The portion of the cored bar member 202 that is not inserted into the coil body 201 has a coefficient of friction between the coated cored bar member 202 and the inner wall of the blood vessel. It is coated with a coating material that is smaller than the coefficient of friction between the two. As this coating material, a hydrophilic coating material may be used. For example, tetrafluoroethylene may be used as a coating material.

  In addition, it is not necessary to coat all the portions inserted in the coil body 201 with the coating material, and at least a portion is coated with the coating material. Similarly, it is not necessary to coat all portions of the cored bar member 202 that are not inserted into the coil body 201 with the coating material, and at least a portion may be coated with the coating material. However, it is preferable to coat all of them because the friction improving effect and the friction reducing effect of the coating can be enhanced.

  Here, in order to manufacture the guide wire 200 (FIG. 3) of the present embodiment, first, the coated cored bar member 202 described above is inserted into a portion of the cored bar member 202 inserted into the coil body 201. A coating material in which the friction coefficient between the coil body 201 and the coil body 201 before coating is larger than the friction coefficient between the coil body 201 and the coil body 201 is coated. The coating material in which the coefficient of friction between the coated cored bar member 202 and the inner wall of the blood vessel is smaller than the coefficient of friction between the coated cored bar member 202 and the inner wall of the blood vessel is coated. Next, the coil body 201 is fixed to the coated cored bar member 202. Next, a hydrophilic material such as maleic anhydride or polyvinyl pyrrolidone is coated on the surface of the coil body 201.

  As described above, in the guide wire 200 of the present embodiment, the entire surface is coated with a hydrophilic coating so that the inner wall of the blood vessel can smoothly travel, while the inner surface of the cored bar member 202 on the coil body 201 is coated. The insertion portion is coated with a coating material that increases the friction between the cored bar member 202 and the coil body 201.

  In the above configuration, the guide wire 200 is inserted into the blood vessel when the doctor operates the hand portion 204. Then, the guide wire 200 bends the coil body 201 along the blood vessel. When the coil body 201 is bent along the blood vessel, the cored bar member 202 comes into contact with the inner surface of the coil body 201. At this time, since the coefficient of friction between the cored bar member 202 and the inner surface of the coil body 201 is increased by the coating material, the coil body 201 is pushed to the distal side while suppressing the buckling of the coil body 201. Will be able to.

  Here, in practice, in order to advance the coil body 201 in the blood vessel, the resistance received from the blood vessel increases as the curvature of the coil body 201 to be bent decreases, and thus a large pushing force is required. As the curvature of the coil body 201 decreases, the force with which the cored bar member 202 abuts on the coil body 201 also increases, so that a large frictional force can be obtained and a larger pushing force can be obtained. In the present embodiment, paying attention to this point, the core metal member 202 is coated with a coating material that increases the coefficient of friction between the coil body 201 and the core metal member 202 and the coil body 201. Active use of frictional force. As a result, a larger pushing force can be obtained under a situation where a large pushing force is required (that is, under a situation where the curvature of the coil body 201 is small).

  In addition to the case where the coil body 201 is bent along the blood vessel, the metal core member 202 and the coil body 201 may be formed by the resistance of the blood vessel wall when the coil body 201 is advanced in the blood vessel, for example. Even when bent, it abuts. In the configuration of the present embodiment, in this case as well, a larger frictional force is generated between the cored bar member 202 and the coil body 201 as compared with the conventional case, and therefore the cored bar member 202 is caused to be coiled by the frictional force. Can be pushed forward to advance further.

  As described above, according to the present embodiment, in the medical guide wire 200 having the coil body 201 and the linear core metal member 202 inserted in the coil body 201, the core metal member 202 is formed. The coil body is coated with a material whose friction coefficient between the coated core metal member 202 and the coil body 201 is larger than the friction coefficient between the core metal member 202 and the coil body 201 before coating. Without impairing the flexibility and operability of 201, the guide wire 200 with improved pushing force can be realized.

  Moreover, since it can implement | achieve only by coating the metal core member 202, manufacture is easy.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  The present invention can be applied to a medical guide wire having a cored bar member.

DESCRIPTION OF SYMBOLS 100 Balloon catheter 110 Hub 120 Balloon 130 Proximal shaft 131 Metal tube 132 Outer tube 133 Inner tube 140 Distal shaft 150 Guide wire insertion port 170 Core wire 200 Guide wire 201 Coil body 202 Core metal member

Claims (4)

A coil body;
A linear core member inserted in the coil body;
A medical guidewire having:
The metal core member is
At least a portion inserted in the coil body has a coefficient of friction between the cored bar member after coating and the coiled body greater than a coefficient of friction between the cored bar member before coating and the coiled body. while being coated with a coating material comprising,
At least a portion not inserted in the coil body has a coefficient of friction between the cored bar member after coating and the inner wall of the blood vessel smaller than a coefficient of friction between the cored bar member before coating and the inner wall of the blood vessel. Coated with coating material,
Medical guide wire. The coating material that coats at least a portion inserted in the coil body is a polymer.
The medical guide wire according to claim 1 . The coating material that coats at least a portion inserted in the coil body is a urethane resin, an epoxy resin, or a polyether block amide copolymer.
The medical guide wire according to claim 1 or 2 . The coating material that coats at least a portion that is not inserted into the coil body is a hydrophilic coating material.
The medical guide wire according to any one of claims 1 to 3 .

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