JP2023072216A - medical device - Google Patents

Abstract

To provide a medical device which supports a guide wire to be able to pass through a lesioned part, while improving operability of the guide wire.SOLUTION: A medical device 1 comprises: a shaft 10 which has a guide wire lumen 25 for a guide wire G to pass therethrough and extends in an axial direction; and an elastic body 20 which is provided at the tip of the shaft and is capable of expanding the inner diameter of the guide wire lumen with negative pressure.SELECTED DRAWING: Figure 12

Description

The present invention relates to medical devices.

When performing various treatments in a body lumen such as a blood vessel, an operator delivers a guiding catheter to a location close to a lesion along a guide wire previously inserted into the blood vessel. After guiding the tip of the guiding catheter to a location near the lesion, the operator advances a therapeutic device such as a balloon catheter from the tip of the guiding catheter to treat the lesion (for example, a stenosis formed in a blood vessel). part).

Prior to treating the narrowed area with a therapeutic device such as a balloon catheter, it is necessary to pass a guide wire through the narrowed area. However, since the guide wire is generally formed to be flexible, it is difficult to pass through an obstructive lesion or a calcified lesion (hereinafter referred to as a lesion).

In this regard, for example, Patent Literature 1 below discloses a guidewire support catheter (corresponding to a medical device) capable of improving rigidity.

JP 2018-11953 A

However, in the case of the guidewire support catheter described above, since there is a gap between the inner tubular member and the guidewire, the operability of the guidewire is not always good.

An object of the present invention is to solve the above problems, and to provide a medical device that improves the operability of the guidewire and supports the guidewire so that the guidewire can pass through a lesion. .

The medical device includes a guidewire lumen through which a guidewire passes, a shaft portion extending in the axial direction, and a distal end portion of the shaft portion, and the inner diameter of the guidewire lumen can be expanded by negative pressure. and an elastic body.

According to the medical device of the present invention, the outer diameter and inner diameter of the guidewire lumen can be adjusted by the elastic body provided at the distal end portion of the shaft portion. Therefore, the gap between the guide wire lumen of the shaft portion and the guide wire can be reduced. Therefore, it is possible to provide a medical device that supports a guidewire so that the guidewire can pass through a lesion while improving the operability of the guidewire.

1 is an overall view showing a medical device according to an embodiment of the invention; FIG. FIG. 4 is a schematic cross-sectional view showing the vicinity of the distal end portion of the medical device according to the present embodiment, showing a state in which no pressure is applied to the elastic body. 3 is a cross-sectional view taken along line 3-3 of FIG. 2; FIG. FIG. 3 is a cross-sectional view taken along line 4-4 of FIG. 2; FIG. 4 is a schematic cross-sectional view showing the vicinity of the distal end portion of the medical device according to the present embodiment, showing a state in which a negative pressure is applied to the elastic body. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5; FIG. 4 is a schematic cross-sectional view showing the vicinity of the distal end portion of the medical device according to the present embodiment, showing a state in which a positive pressure is applied to the elastic body. FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7; FIG. 4 is a schematic cross-sectional view showing the vicinity of the distal end portion of a support catheter according to a comparative example; FIG. 3 is a schematic cross-sectional view showing the vicinity of the distal end portion of the medical device according to the present embodiment; FIG. 4 is a schematic cross-sectional view showing how to use the medical device according to the present embodiment, showing how a guide wire is inserted into a blood vessel. FIG. 4 is a schematic cross-sectional view showing the method of using the medical device according to the present embodiment, showing how the medical device has been inserted to the vicinity of a lesion via a guidewire. FIG. 4A is a schematic cross-sectional view showing a method of using the medical device according to the present embodiment, and showing a state in which the medical device supports the guidewire to be gripped. FIG. 4B is a schematic cross-sectional view showing a method of using the medical device according to the present embodiment, showing a state in which the guidewire supported by the medical device is moved to the distal side. It is a figure corresponding to Drawing 2 of a medical device concerning a modification.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

FIG. 1 is an overall view showing a medical device 1 according to an embodiment of the invention. FIG. 2 is a schematic cross-sectional view showing the vicinity of the distal end portion 1A of the medical device 1 according to this embodiment, showing a state in which no pressure is applied to the elastic body 20. As shown in FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2. FIG. FIG. 5 is a schematic cross-sectional view showing the vicinity of the distal end portion 1A of the medical device 1 according to this embodiment, showing a state in which a negative pressure is applied to the elastic body 20. As shown in FIG. FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. FIG. 7 is a schematic cross-sectional view showing the vicinity of the distal end portion 1A of the medical device 1 according to this embodiment, showing a state in which a positive pressure is applied to the elastic body 20. As shown in FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7. FIG.

In this specification, the direction in which the straight shaft portion 10 extends is defined as the axial direction. In the axial direction, the side inserted into the biological lumen (left side in FIG. 2) is defined as the "distal side", and the proximal side (right side in FIG. 2) is defined as the "proximal side". In each component of the medical device 1, a portion including a certain range in the axial direction from the tip (most tip) is defined as a "tip".

The medical device 1 according to this embodiment functions as a support catheter that supports the guide wire G (see FIGS. 13 and 14). The configuration of the medical device 1 will be described below.

As shown in FIGS. 1 to 8, the medical device 1 includes a shaft portion 10 extending in the axial direction, an elastic body 20 provided at the tip of the shaft portion 10, and a pressure applied to the elastic body 20. It has a pressure adjusting portion 30 and a hub 40 provided at the proximal end of the shaft portion 10 .

As shown in FIGS. 2, 5, and 7, the shaft portion 10 includes an outer tube 11 extending in the axial direction, an inner tube 12 arranged on the inner peripheral side of the outer tube 11, an outer tube 11 and an inner tube. and a flow lumen 13 provided between the tubes 12 .

The outer tube 11 may have any outer diameter as long as it can be inserted into a blood vessel reaching a lesion. Further, the inner diameter of the outer tube 11 is not particularly limited as long as a space capable of applying pressure from the elastic body 20 can be maintained between the outer diameters of the inner tube 12, which will be described later.

The material constituting the outer tube 11 is not particularly limited, but examples include polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), fluorine-based resins such as perfluoroalkoxy fluorine resin (PFA), polyethylene, Examples include olefinic resins such as polypropylene, mixtures thereof, polyurethane, polyester, polyamide, polyether nylon resins, and mixtures of olefinic resins and ethylene/vinyl acetate copolymers.

The inner tube 12 is provided extending in the axial direction. The distal end 12A of the inner tube 12 is arranged closer to the proximal side than the distal end 11A of the outer tube 11 is. An elastic body 20 is fixed to the tip 12A of the inner tube 12 .

The outer diameter of the inner tube 12 is not particularly limited as long as a space capable of applying pressure from the elastic body 20 can be maintained between the inner diameters of the outer tube 11 described above. Moreover, the inner diameter of the inner tube 12 may be any dimension that allows the guide wire to be used to be operated.

The material forming the inner tube 12 may be the same as the material forming the outer tube 11 .

The proximal end 20B of the elastic body 20 is fixed to the distal end 12A of the inner tube 12, as shown in FIG. A method of fixing the elastic body 20 to the inner pipe 12 is not particularly limited, but for example, it may be adhered with an adhesive.

The elastic body 20 has a first inner diameter D1 in a non-pressurized state, as shown in FIG. Moreover, as shown in FIG. 6, the elastic body 20 has a second inner diameter D2 under a negative pressure. As shown in FIG. 8, the elastic body 20 has a third inner diameter D3 under positive pressure. The second inner diameter D2 is greater than the first inner diameter D1, which is greater than the third inner diameter D3. Also, the third inner diameter D3 is configured to be greater than or equal to or less than the outer diameter of the guidewire.

The first inner diameter D1 is, for example, 0.36-0.89 mm. The second inner diameter D2 is, for example, 0.40-1.00 mm. The third inner diameter D3 is, for example, 0.30-0.80 mm.

The thickness of the elastic body 20 may be any thickness as long as it does not interfere with the insertion of the guide wire under negative pressure and has the strength to withstand negative and positive pressure. Also, the axial length of the elastic body 20 is not particularly limited, but is 6 to 200 mm.

For example, elastic rubber can be used as the elastic body 20, but the elastic body 20 is not limited to this.

The pressure adjuster 30 adjusts the pressure applied to the elastic body 20 . The pressure adjustment portion 30 is provided on the proximal end side of the shaft portion 10 .

The pressure adjustment unit 30 sends a fluid (working fluid) to the circulation lumen 13 to make the circulation lumen 13 have a positive pressure, thereby making the pressure applied to the elastic body 20 a positive pressure and adjusting the inner diameter of the guide wire lumen 25. is reduced (see FIGS. 7 and 8). On the other hand, the pressure adjustment unit 30 sucks the circulation lumen 13 to make the circulation lumen 13 negative pressure, thereby making the pressure applied to the elastic body 20 negative pressure and expanding the inner diameter of the guidewire lumen 25 ( 5 and 6). The working fluid can be, for example, a mixture of contrast medium and saline.

The pressure adjustment part 30 is connected to the second opening 42 of the hub 40 in a liquid-tight and air-tight manner. A known indeflator or the like can be used for the pressure adjustment unit 30 .

Hub 40 has a first opening 41 forming a guidewire port and a second opening 42 forming an injection port, as shown in FIG.

Examples of the material of the hub 40 include thermoplastic resins such as polycarbonate, polyamide, polysarsan, polyarylate, and methacrylate-butylene-styrene copolymer.

Next, referring to FIGS. 11 to 14, the case of treating an occlusive lesion or a calcified lesion (referred to as a lesion portion N) in a blood vessel B (for example, a coronary artery) is taken as an example. A method of using the device 1 will be described.

First, the operator inserts the tip of a guiding catheter (not shown) from a predetermined position in the living body, and reaches the coronary artery through the radial artery or the femoral artery.

Next, as shown in FIG. 11, the operator inserts the guide wire G into the blood vessel B through the guiding catheter and reaches the vicinity of the lesion N. As shown in FIG. Here, since the guide wire G is generally formed to be flexible, it is difficult to pass through the obstructed lesion N.

Next, as shown in FIG. 12, the operator inserts the medical device 1 according to this embodiment into the blood vessel B through the guide wire G to reach the vicinity of the lesion N. As shown in FIG. At this time, the pressure adjustment unit 30 sucks the flow lumen 13 to make the pressure in the flow lumen 13 negative, thereby reducing the pressure applied to the elastic body 20 to a negative pressure, thereby expanding the inner diameter of the guidewire lumen 25. . As a result, the medical device 1 is inserted into the blood vessel B via the guide wire G in a state in which the inner diameter of the guide wire lumen 25 is expanded. , can be preferably inserted.

Next, as shown in FIG. 13 , the operator operates the pressure adjustment unit 30 to send the fluid (working fluid) to the circulation lumen 13 and apply pressure to the elastic body 20 by making the circulation lumen 13 have a positive pressure. The internal diameter of the guidewire lumen 25 is reduced by making the pressure to be positive. As a result, the elastic body 20 comes into contact with the guide wire G and supports the guide wire G so as to be gripped.

Here, for example, if there is a clearance between the support catheter (medical device) and the guide wire G, as shown in FIG. Buckling occurs at a point separated by a distance. On the other hand, according to the medical device 1 according to the present embodiment, as shown in FIG. 10, the guide wire G can be gripped at the distal end of the medical device 1, so that the buckling of the guide wire G is preferably prevented. can be prevented.

In addition, in the support catheter 900 according to the comparative example, when the distance from the buckled portion of the guide wire G to the distal end is L1, the end state is n, the elastic modulus is E, and the section modulus is I, the guide wire G can be calculated by P=nEIπ ² /L1 ² . Similarly, in the medical device 1 according to this embodiment, when the axial distance at which the guide wire G is exposed from the medical device 1 is L2, the end state is n, the elastic modulus is E, and the section modulus is I, Furthermore, the buckling resistance load P of the guide wire G can be calculated by P=nEIπ ² /L2 ² . That is, according to the medical device 1 according to the present embodiment, since the distance (L2<L1) can be shortened, the buckling load resistance P can be improved, and the buckling of the guide wire G can be favorably performed. can be suppressed.

Next, as shown in FIG. 14, the operator moves the medical device 1 and the guide wire G to the distal side while maintaining the state in which the medical device 1 grips and supports the guide wire G. As shown in FIG. At this time, since the guide wire G is held by the medical device 1, the buckling load resistance P of the guide wire G is improved, and the lesion N can be penetrated without the guide wire G buckling. can. Depending on the state of the lesion N, any one of the first guide wire (eg, 0.035 inches), the second guide wire (eg, 0.018 inches), and the third guide wire (eg, 0.014 inches) Used as appropriate.

Here, in the case of a support catheter in which the inner diameter of the guidewire lumen does not expand or contract, it is necessary to prepare a support catheter corresponding to the diameter of each guidewire G. On the other hand, according to the medical device 1 according to the present embodiment, the inner diameter of the guidewire lumen 25 can be appropriately expanded and contracted as the elastic body 20 is expanded and contracted. Both the second guide wire and the third guide wire can be grasped and supported, improving versatility.

Next, after removing the medical device 1, the operator brings a treatment device such as a balloon catheter to the lesion N through the guide wire G to perform a predetermined treatment.

As described above, the medical device 1 according to this embodiment includes the guidewire lumen 25 through which the guidewire G passes, the shaft portion 10 extending in the axial direction, and the distal end portion of the shaft portion 10. and an elastic body 20 capable of expanding the inner diameter of the guidewire lumen 25 by negative pressure. According to the medical device 1 configured in this manner, the outer diameter and inner diameter of the guidewire lumen 25 can be adjusted by the elastic body 20 provided at the distal end portion of the shaft portion 10 . Therefore, the gap between the guide wire lumen 25 of the shaft portion 10 and the guide wire G can be reduced. Therefore, it is possible to provide the medical device 1 that supports the guide wire G so that the guide wire G can pass through the lesion N while improving the operability of the guide wire G.

In addition, the elastic body 20 has a first inner diameter D1 in a state in which no pressure is applied, and a second inner diameter D2 that is larger than the first inner diameter D1 in a state in which negative pressure is applied. According to the medical device 1 configured in this way, when the medical device 1 is inserted into the blood vessel B through the guide wire G, the medical device 1 is prevented from being caught on the guide wire G, can be suitably inserted.

Further, the elastic body 20 has a third inner diameter D3 smaller than the second inner diameter D2 in a state of applying positive pressure. According to the medical device 1 configured in this way, when the guide wire G is moved to the lesion N, the guide wire G can be suitably grasped and supported.

Also, the third inner diameter D3 is equal to or less than the outer diameter of the guide wire G. According to the medical device 1 configured in this way, the guide wire G can be gripped and supported more favorably.

Further, the shaft portion 10 is provided between the outer tube 11 extending in the axial direction, the inner tube 12 arranged on the inner peripheral side of the outer tube 11, and the outer tube 11 and the inner tube 12 so that the fluid flows. and a possible flow lumen 13 . The elastic body 20 is connected to the distal end of the inner tube 12 and expands the inner diameter of the guidewire lumen 25 by applying a negative pressure to the flow lumen 13 . According to the medical device 1 configured in this manner, the inner diameter of the guidewire lumen 25 can be expanded by applying a negative pressure to the circulation lumen 13 by the pressure adjustment unit 30, so that the expansion and contraction of the elastic body 20 can be easily performed. Adjustable.

Moreover, the elastic body 20 is elastic rubber. According to the medical device 1 configured in this way, the elastic body 20 can be formed with a simple configuration.

Next, the configuration of the medical device 2 according to the modification will be described with reference to FIG. 15 . The medical device 2 according to the modification differs from the medical device 1 according to the embodiment in the configuration of the shaft portion 110 .

As shown in FIG. 15, the medical device 2 according to the modification is provided with a shaft portion 110 extending in the axial direction and a distal end portion of the shaft portion 110, and the inner diameter of the guidewire lumen 25 is expanded by negative pressure. a possible elastic body 20; The elastic body 20 of the medical device 2 according to the modified example has the same configuration as the elastic body 20 of the medical device 1 according to the above-described embodiment, so the description thereof is omitted.

The shaft portion 110 has a main body portion 111 extending in the axial direction, and a circulation lumen 113 provided in the main body portion 111 through which fluid can flow. The elastic body 20 is provided on the inner peripheral side of the tip portion 111A of the body portion 111 . A method of fixing the elastic body 20 to the main body 111 is not particularly limited, but for example, it may be adhered with an adhesive.

Since the method of using the medical device 2 according to the modification is substantially the same as that of the medical device 1 according to the embodiment, the explanation is omitted.

As described above, the shaft portion 110 of the medical device 2 according to the modification includes the main body portion 111 extending in the axial direction and the circulation lumen 113 provided in the main body portion 111 and through which fluid can flow. The elastic body 20 is provided on the inner peripheral side of the distal end portion of the main body portion 111 and expands the inner diameter of the guidewire lumen 25 by applying a negative pressure to the flow lumen 113 . According to the medical device 2 configured in this manner, the inner diameter of the guidewire lumen 25 can be expanded by applying a negative pressure to the circulation lumen 113 by the pressure adjustment unit 30, so that the expansion and contraction of the elastic body 20 can be easily performed. Adjustable.

Although the medical devices 1 and 2 according to the present invention have been described above through the embodiments and modifications, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

For example, in the embodiment described above, the third inner diameter D3 is equal to or smaller than the outer diameter of the guidewire G, but the third inner diameter D3 may be larger than the outer diameter of the guidewire G.

1, 2 medical devices,
10, 110 shaft portion,
11 outer tube,
12 inner tube,
13, 113 distribution lumens,
111 main body,
20 elastic body,
25 lumen for guide wire,
B blood vessels,
D1 first inner diameter;
D2 second inner diameter;
D3 third inner diameter,
G guide wire,
N lesion.

Claims (7)

an axially extending shaft portion having a guidewire lumen through which the guidewire passes;
and an elastic body provided at the distal end of the shaft portion and capable of expanding the inner diameter of the guidewire lumen by negative pressure. 2. The medical treatment according to claim 1, wherein the elastic body has a first inner diameter when no pressure is applied, and a second inner diameter larger than the first inner diameter when a negative pressure is applied. device. 3. The medical device according to claim 2, wherein the elastic body has a third inner diameter smaller than the second inner diameter in a state of applying positive pressure. 4. The medical device of claim 3, wherein the third inner diameter is greater than or equal to or less than the outer diameter of the guidewire. The shaft portion
an outer tube extending in the axial direction;
an inner tube arranged on the inner peripheral side of the outer tube;
a circulation lumen provided between the outer tube and the inner tube through which a fluid can flow;
The elastic body is connected to the tip of the inner tube,
The medical device according to any one of claims 1 to 4, wherein the inner diameter of the guidewire lumen is expanded by applying a negative pressure to the flow lumen. The shaft portion
a body portion extending in the axial direction;
a circulation lumen provided in the main body and through which a fluid can flow;
The elastic body is provided on the inner peripheral side of the tip of the main body,
The medical device according to any one of claims 1 to 4, wherein the inner diameter of the guidewire lumen is expanded by applying a negative pressure to the flow lumen. The medical device according to any one of claims 1 to 6, wherein the elastic body is elastic rubber.

Images