WO2018163564A1

WO2018163564A1 - Catheter

Info

Publication number: WO2018163564A1
Application number: PCT/JP2017/045986
Authority: WO
Inventors: 太陽山下
Original assignee: テルモ株式会社
Priority date: 2017-03-07
Filing date: 2017-12-21
Publication date: 2018-09-13
Also published as: JP2020072769A

Abstract

[Problem] To provide a catheter, wherein the visibility of the most distal end of the catheter under radioscopy can be improved while ensuring the safety of the catheter. [Solution] This catheter 100 has: a tubular shaft part 110 having a tip section 110d formed of a resin; and an annular marker part 120 disposed at the tip section of the shaft part and formed of a radiopaque metal. The tip section of the shaft part has: a tapered portion 111; and a constant-outer-diameter portion disposed closer to the base end side than the tapered portion. The marker part has: a marker tip section 121 disposed on the tapered portion so as to follow the outer shape of the tapered portion; and a marker base end section 125 disposed on the constant-outer-diameter portion. A first region A1, which is formed by the tapered portion and the marker tip section, has a higher resin content per unit volume than a second region A2, which is formed by the constant-outer-diameter portion and the marker base end section.

Description

catheter

The present invention relates to a catheter.

Conventionally, catheters have been used to treat and diagnose lesions in living body lumens. The surgeon inserts the catheter into the living body lumen and arranges the distal end portion of the catheter at the lesion site as the target site to treat or diagnose the lesion site.

For example, Patent Document 1 below discloses a catheter having a ring-shaped marker portion having radiopacity at the distal end portion. When the operator confirms the position of the marker portion under radioscopy, it becomes easy to position the distal end portion of the catheter at or near the lesioned portion.

Generally, the marker portion is made of a relatively rigid material such as metal. For this reason, as shown in Patent Document 1 below, the marker portion is disposed at a position spaced from the most distal end of the catheter to the proximal end side, and a soft resin is disposed on the distal end side to ensure safety with respect to the living body lumen. Yes.

JP2013-81655A

However, if the marker portion is disposed at a position spaced from the most distal end of the catheter toward the proximal end side, the most distal position of the catheter cannot be accurately grasped under radioscopy.

In addition, the portion where the marker portion having relatively high rigidity is arranged in the catheter and the vicinity thereof have high rigidity. Thereby, the flexibility (easy to bend) of the distal end portion of the catheter is reduced, and the safety may be lowered.

The present invention has been made to solve the above-described problems, and provides a catheter capable of improving the state-of-the-art visibility of a catheter under radioscopy while ensuring the safety of the catheter. Objective.

The catheter according to the present invention includes a tubular shaft portion having a distal end portion formed of a resin, a ring-shaped marker portion disposed at the distal end portion of the shaft portion and formed of a radiopaque metal, A catheter having The distal end portion of the shaft portion includes a tapered portion formed in a tapered shape including the most distal end and an outer diameter of the shaft portion tapering toward the distal end side, and is disposed closer to the proximal end side than the tapered portion, and is axially And a constant outer diameter portion having a substantially constant outer diameter. The marker part has a marker tip part arranged at the taper part so as to follow the outer shape of the taper part, and a marker base end part arranged at the constant outer diameter part. The first region constituted by the tapered portion and the marker tip end portion has a higher resin content per unit volume than the second region constituted by the constant outer diameter portion and the marker base end portion.

According to the catheter configured as described above, since the tip of the marker is arranged so as to follow the outer shape of the tapered portion, by observing the marker portion under radioscopy, the most advanced position of the catheter can be improved. Accurately grasp. Further, since the first region is formed with a higher resin content per unit volume than the second region, the most advanced rigidity of the catheter can be reduced. Moreover, since the marker part can be arranged on the distal end side of the catheter with the above configuration, the starting point of the bending of the catheter can be further on the distal end side. Thereby, the bendability (flexibility) of the distal end portion of the catheter can be improved. Therefore, according to the catheter, the most advanced visibility of the catheter under radioscopy can be improved while ensuring the safety of the catheter.

It is the schematic which shows the catheter which concerns on embodiment of this invention. It is a side view which expands and shows the front-end | tip part of the catheter which concerns on embodiment. It is an axial direction sectional view expanding and showing a tip portion of a catheter concerning an embodiment. It is a side view of the marker part which concerns on embodiment. It is a perspective view of the marker part which concerns on embodiment. It is a side view which expands and shows the front-end | tip part of the catheter which concerns on contrast. It is the schematic which shows a mode that the catheter which concerns on embodiment and a comparison was bent. FIG. 8A is a diagram showing a schematic configuration of a catheter abutment test, and FIG. 8B is a diagram showing a state of the catheter according to the embodiment and the comparison in the abutment test. It is a side view of the marker part which concerns on the modification 1 of this invention. It is a side view of the marker part which concerns on the modification 2 of this invention. FIG. 11A is a side view of a marker portion according to the third modification of the present invention, and FIG. 11B is an axial sectional view of the marker portion according to the third modification. It is a side view of the marker part which concerns on the modification of this invention. It is a side view of the marker part which concerns on the modification of this invention. It is a side view of the marker part which concerns on the modification of this invention. It is a side view of the marker part which concerns on the modification of this invention. It is a side view of the marker part which concerns on the modification of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following description does not limit the technical scope and terms used in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from actual ratios.

FIG. 1 is a schematic view showing a catheter 100, FIGS. 2 and 3 are enlarged side views and axial sectional views showing a distal end portion of the catheter 100, and FIGS. 4 and 5 are side views and perspective views of a marker portion. FIG.

The catheter 100 according to the present embodiment is a microcatheter used for supplying a drug or a contrast medium to a lesioned part. The catheter 100 is used, for example, for transcatheter arterial chemoembolization (TACE). Hepatic artery chemoembolization is a treatment method in which a catheter is advanced from the liver artery further to the vicinity of the tumor, and an anticancer agent or embolic material is injected to selectively necrotize the tumor.

The catheter 100 will be outlined with reference to FIGS. The catheter 100 has a distal end portion 110d formed of resin, a tubular shaft portion 110 that can be introduced into a living body, and a ring shape that is disposed on the distal end portion 110d of the shaft portion 110 and is formed of a radiopaque metal. The marker portion 120 and the catheter hub 130 connected to the proximal end portion of the shaft portion 110 are included. The catheter 100 has a kink protector (strain relief) 135 in the vicinity of the connecting portion between the shaft portion 110 and the catheter hub 130. The catheter 100 is not limited to the configuration shown in FIG. 1 and may not include the kink protector 135.

As shown in FIGS. 2 and 3, the catheter 100 has a contrast region A having radiopacity due to the arrangement of the marker portion 120. The contrast area A has a first area A1 including the most distal end, and a second area A2 disposed on the proximal side of the first area A1. Details of the contrast region A will be described later.

In the description of this specification, the longitudinal direction (left-right direction in FIG. 1) in which the shaft portion 110 of the catheter 100 extends is defined as the axial direction, and is indicated by an arrow X in each figure. A direction orthogonal to the axial direction is defined as a radial direction and is indicated by an arrow R. The side to be inserted into the living body (intravascular) in the catheter 100 is defined as the tip side (distal side, left side in FIG. 1), and is indicated by an arrow X1 in each figure and is located on the side opposite to the tip side. The side on which the above operations are performed is defined as a proximal side (proximal side, right side in FIG. 1), and is indicated by an arrow X2 in each figure.

Further, in this specification, the “leading end of the catheter 100” is not limited to the most distal end of the catheter 100, and the surgeon places the most distal end of the catheter 100 on the basis of the marker portion 120 under radioscopy. When placing in the cavity, an error within an allowable range (allowable error) is also included. For example, the tolerance of the position of the most distal end of the catheter 100 that is actually disposed with respect to the position where the distal end of the catheter 100 is to be disposed (for example, the distal end of the lesion) is set to about 0.1 mm to 0.8 mm. The That is, in this specification, the range from about 0.1 mm to 0.8 mm from the most distal end to the proximal end side of the catheter 100 is defined as “the most advanced”. Note that the permissible error is approximately the same as the thickness t1 (see FIG. 3) of the outer layer 115 of the shaft portion 110 that covers the marker portion 120 at the tip of the shaft portion 110.

Further, in this specification, the “tip portion of the catheter 100” means a range that substantially contributes to the flexibility required for any procedure of the catheter 100 and the followability along the shape of the living body lumen. . For example, when the catheter 100 is used for hepatic artery chemoembolization, the distal end portion of the catheter 100 ranges from the aorta to the intrinsic hepatic artery, and is about 300 to 400 mm along the axial direction from the most distal end of the shaft portion 110. Means up to.

(Shaft part)
As shown in FIG. 1, the shaft portion 110 is configured as a flexible tubular member extending in the axial direction and having a lumen 110a through which the guide wire GW can be inserted. As shown in FIG. 3, the tip portion 110d of the shaft portion 110 is disposed in the first region A1, and has a taper formed in a tapered shape with an outer diameter gradually decreasing toward the tip side (inclined with respect to the axial direction). It has a portion 111 and a constant outer diameter portion 112 that is disposed in the second region A2 on the proximal side of the tapered portion 111 and has a substantially constant outer diameter along the axial direction. By providing the tapered portion 111, the insertion property of the catheter 100 into the living body lumen can be improved.

In the present specification, “having a substantially constant outer diameter along the axial direction” is not limited to having the physically same outer diameter. As long as the rigidity (bending rigidity and torsional rigidity) of the constant outer diameter portion 112 of the shaft portion 110 can be made substantially constant, it is only necessary to have a substantially constant outer diameter dimension.

In the present embodiment, the tapered portion 111 has an axial cross-sectional shape that is inclined substantially linearly. That is, the inclination angle of the tapered portion 111 with respect to the axial direction of the tapered shape is constant along the axial direction. In addition, the axial cross-sectional shape of the taper portion 111 is not limited to this, and for example, has an axial cross-sectional shape curved in a convex shape radially outward and an axial cross-sectional shape curved in a concave shape radially inward. It may be.

When the inclination angle of the tapered portion 111 is made constant along the axial direction, the tapered portion 111 can be easily formed as compared with the case where the tapered angle is changed along the axial direction.

The tip of the tapered portion 111 has a rounded shape. Thereby, the risk of damaging the inner wall of the living body lumen can be reduced.

The preferred value of the length of the shaft portion 110 varies depending on the position and thickness of the blood vessel to be applied, but is set to about 700 mm to 2000 mm, for example. The preferable value of the outer diameter (thickness) of the shaft portion 110 varies depending on the position and thickness of the blood vessel to be applied, but is set to about 0.4 mm to 2.8 mm, for example. The preferable value of the inner diameter of the shaft portion 110 (the outer diameter of the lumen 110a) varies depending on the thickness of the guide wire GW to be inserted, the position of the blood vessel to be applied, the thickness, and the like. It is set to about 2.4 mm.

As shown in FIG. 3, the shaft portion 110 includes a tubular inner layer 113, a reinforcing body 114 that is disposed on the proximal side of the portion where the contrast region A is formed, and is formed by braiding a wire, and a reinforcing body. 114 and an outer layer 115 arranged to cover the outer surface of the inner layer 113. The inner layer 113 and the outer layer 115 are made of only a resin that does not contain a metal.

The distal end portion 110d of the shaft portion 110 corresponding to the contrast region A of the catheter 100 is configured with only the inner layer 113 and the outer layer 115 without the reinforcement body 114 being disposed. That is, the tip portion 110d of the shaft portion 110 is made of only resin.

The inner layer 113 has a substantially constant thickness along the axial direction. The distal end portion of the outer layer 115 is formed in a tapered shape whose outer diameter gradually decreases from the proximal end side toward the forefront. The tip of the outer layer 115 formed in the tapered shape constitutes a tapered portion 111.

Examples of the constituent material of the inner layer 113 include PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (ethylene). A resin such as a fluorine-containing ethylenic polymer such as (tetrafluoroethylene copolymer), a polyamide such as nylon, or a polyamide elastomer such as nylon elastomer can be used. Among these, PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) having high lubricity can be preferably used. By using these materials, it becomes possible to reduce the frictional resistance of the inner surface, so that the operability of the guide wire GW inserted into the lumen 110a of the shaft portion 110 when using the catheter 100 can be improved. it can.

The reinforcing body 114 is configured in a mesh shape by braiding predetermined strands (wires) on the outer surface of the inner layer 113. The reinforcing body 114 is formed over substantially the entire length excluding the distal end portion 110 d of the shaft portion 110 with respect to the longitudinal direction of the catheter 100. The reinforcing body 114 is not limited to a mesh shape, and may be configured in a coil shape.

As the strands constituting the reinforcing body 114, for example, metal strands, resin strands, or a combination of metal strands and resin strands can be used. From the viewpoint of the workability of the strands and the manufacturability of the reinforcing body 114, it is preferably a metal strand. From the viewpoint of flexibility, stretchability, and electrical insulation, the molten liquid crystal polymer is used as the inner core, and the flexibility is improved. A monofilament resin strand having a polymer as an outer layer is preferred.

Examples of the metal strand include stainless steel, tungsten, copper, nickel, titanium, piano wire, cobalt-chromium alloy, nickel-titanium alloy (superelastic alloy), copper-zinc alloy, amorphous alloy, etc. Various metal strands can be used.

Although the cross-sectional shape of the strands constituting the reinforcing body 114 is not particularly limited, for example, it can be formed in a substantially circular shape or a substantially rectangular shape. However, from the viewpoint of improving operability by increasing the density of the reinforcing bodies 114, the cross-sectional shape of the strands is preferably substantially rectangular.

Examples of the constituent material of the outer layer 115 include polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, and the like. And polymer materials such as polyamide, polyester, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluorine resin, or a mixture thereof. The outer layer 115 may have a multilayer structure formed by stacking different resin materials. It is also possible to form a hydrophilic coat layer or the like by covering the outer surface of the outer layer 115 with a material made of a hydrophilic polymer.

(Marker part)
As shown in FIG. 3, the marker unit 120 is disposed on the tip side of the reinforcing body 114 and is embedded in the outer layer 115.

The marker portion 120 has a marker tip portion 121 and a marker base end portion 125 that is continuous with the base end of the marker tip portion 121 and has a constant outer diameter along the axial direction.

The marker distal end portion 121 is disposed on the tapered portion 111 of the shaft portion 110 corresponding to the first region A1 of the catheter 100, and the outermost end thereof is aligned from the proximal end side so as to follow the outer shape of the tapered portion 111 of the shaft portion 110. It is formed in a tapered shape in which the outer diameter gradually decreases (inclined with respect to the axial direction).

As shown in FIG. 4, the marker distal end portion 121 has a notch portion 122 that is notched from the most distal end toward the proximal end side. The portion that remains after being cut out by the cutout portion 122 forms a protruding portion 123 that protrudes toward the distal end side.

The length (width) W1 along the circumferential direction of the cutout portion 122 gradually decreases from the front end toward the base end side. That is, the protrusion 123 is formed in a triangular shape having a length (width) W2 that gradually increases in the circumferential direction from the most distal end toward the base end side. Thereby, since the protrusion part 123 does not have a part (constriction) which becomes sharply narrow, the intensity | strength of the marker front-end | tip part 121 can be maintained. Further, by adjusting the length W <b> 1 along the circumferential direction of the notch 122, the marker tip 121 can be formed relatively easily along the outer shape of the tapered portion 111. If the length W1 along the circumferential direction of the notch 122 is too small, the flexibility of the distal end portion of the catheter 100 is lowered. On the other hand, if the length W1 along the circumferential direction of the notch 122 is too large, the visibility of the marker tip 121 under radioscopy is reduced. From the above viewpoint, the length W1 along the circumferential direction of the notch 122 at the tip of the marker 120 is preferably set to about 0.2 to 4.8 mm. Moreover, the base end part of the marker part 120 is comprised so that the length W1 along the circumferential direction of the notch part 122 may become smaller than a front-end | tip part. Referring to FIG. 4, the length L11 of the notch 122 along the axial direction is not particularly limited, but is set to about 0.4 mm to 1.4 mm, for example.

Moreover, the marker part 120 has a plurality of cutout parts 122 along the circumferential direction. If the number of the notches 122 is one, the flexibility of the distal end of the catheter 100 may be reduced depending on the size of the notches 122. Further, when the number of the notch portions 122 is one, the arrangement of the notch portions 122 becomes unbalanced in the circumferential direction of the marker portion 120. On the other hand, if the number of the notch portions 122 is excessively increased, the visibility of the marker tip portion 121 under radioscopy is reduced. From the above viewpoint, the number of the notches 122 is preferably 2 to 8, and more preferably 4.

The tip shape of the protrusion 123 is rounded and chamfered. Thereby, the risk of damaging the inner wall of the living body lumen can be reduced.

The marker base end portion 125 is formed in a cylindrical shape having an outer diameter substantially constant along the axial direction. The marker base end portion 125 is disposed over the entire circumferential direction and axial direction of the outer diameter constant portion 112 of the shaft portion 110 corresponding to the second region A2 of the catheter 100.

Referring to FIG. 4, the length L (L1 + L2) along the axial direction of the marker portion 120 is not particularly limited, but is set to, for example, about 0.5 mm to 1.5 mm. Here, the length L1 along the axial direction of the marker distal end portion 121 is a value similar to the length along the axial direction of the distal end portion 110d of the shaft portion 110 and the length along the axial direction of the contrast region A of the catheter 100. is there.

Further, in the present embodiment, the thickness of the marker portion 120 is formed to be substantially constant and is not particularly limited, but is set to about 0.02 mm to 0.2 mm, for example. Further, the outer diameter of the marker portion 120 can be formed slightly smaller (similar to the outer diameter) of the shaft portion 110. By setting the above range, the volume (amount) of the marker unit 120 determined by the length, thickness, and outer diameter of the marker unit 120 is large enough to maintain visibility under radioscopy. Can be secured.

Further, the length L1 of the marker tip 121 along the axial direction is not particularly limited, but is set to about 0.4 mm to 1.4 mm, for example. The length L2 along the axial direction of the marker base end portion 125 is not particularly limited, but is set to, for example, about 0.1 mm to 1.1 mm. Further, the ratio (L1 / L2) of the length L1 along the axial direction of the marker distal end portion 121 to the length L2 along the axial direction of the marker proximal end portion 125 is set to about 1 to 14. By setting as described above, the marker distal end portion 121 can maintain the softness of the distal end of the catheter 100 to ensure safety, and the marker proximal end portion 125 can ensure radioscopic visibility. it can.

The marker portion 120 is made of a metal material having a radiopacity (X-ray contrast property) higher than that of the inner layer 113 and the outer layer 115. Examples of the radiopaque metallic material include noble metals such as gold, platinum, tungsten, and alloys containing these (eg, platinum-iridium alloys).

(Contrast area)
As described above, the contrast region A has the first region A1 disposed in a certain range from the most advanced state, and the second region A2 disposed on the proximal side from the first region A1.

As shown in FIG. 3, the first region A <b> 1 is configured by arranging the marker tip portion 121 of the marker portion 120 on the tapered portion 111 of the shaft portion 110. The second region A <b> 2 is configured by arranging the marker base end portion 125 of the marker portion 120 in the constant outer diameter portion 112 of the shaft portion 110.

In the first region A1, since the marker tip 121 has a notch 122, the portion of the catheter 100 where the notch 122 is disposed is made of only resin. On the other hand, in the second region A2, the marker base end portion 125 is disposed over the entire circumferential direction and the axial direction of the outer diameter constant portion 112 of the shaft portion 110.

With the above configuration, the first region A1 is formed with a higher resin content per unit volume than the second region A2.

(Catheter hub)
The catheter hub 130 is liquid-tightly attached to the proximal end portion of the shaft portion 110 with an adhesive or a fixture (not shown). As shown in FIG. 1, the catheter hub 130 has a main body portion 131 having a lumen and a pair of handle portions 132 formed so as to protrude from the side portions of the main body portion 131. The catheter hub 130 functions as an insertion port for the guide wire GW into the lumen 110a of the shaft portion 110 and an injection port for a contrast medium, a drug solution, an embolic material, and the like. The catheter hub 130 functions as a grip when operating the catheter 100.

The constituent material of the catheter hub 130 is, for example, a synthetic resin such as polycarbonate, polyolefin, styrene resin, polyamide, or polyester, stainless steel, aluminum, or aluminum alloy. The polyolefin is, for example, polyethylene, polypropylene, ethylene-propylene copolymer.

The kink protector 135 can be formed of an elastic material provided so as to surround a part of the base end portion of the shaft portion 110. As a constituent material of the kink protector 135, for example, natural rubber, silicone resin, or the like can be used.

With reference to FIGS. 6 to 8, the effect of the catheter 100 according to the embodiment will be described by comparing the catheter 100 according to the embodiment with the catheter 200 according to the comparison.

6 is an enlarged side view showing the distal end portion of the catheter 200 according to the proportionality, FIG. 7 is a schematic view showing a state where the

catheters

100 and 200 according to the embodiment and the proportionality are bent, and FIG. FIG. 8 is a diagram showing a schematic configuration of an abutment test of the

catheters

100 and 200, and FIG. 8B is a diagram showing a state of the

catheters

100 and 200 according to the embodiment and a comparison in the abutment test.

As shown in FIG. 6, in the catheter 200 according to the proportionality, a cylindrical marker portion 220 is disposed in the outer diameter constant portion 112 on the proximal end side with respect to the tapered portion 111 of the shaft portion 110. In other words, the marker portion 220 is disposed at a position spaced from the forefront of the shaft portion 110 toward the length proximal end side of L21. In addition, the length L22 along the axial direction of the marker unit 220 is approximately the same as that of the marker unit 220 according to the present embodiment.

If the marker portion 220 is disposed at a position spaced from the most distal end of the catheter 200 to the proximal end side like the catheter 200 related to the proportionality, the most distal position of the catheter 200 cannot be grasped under radioscopy. Further, for example, it may be possible to improve the state-of-the-art visibility of the catheter 200 by placing a resin containing a radiopaque powder on the distal side of the marker portion 220. However, the radiopaque powder Since the resin containing is lower in radiopacity than metal, the state-of-the-art visibility of the catheter 200 under radioscopy is reduced as compared with the case where the metal marker portion 120 is disposed.

The

catheters

100 and 200 have relatively high rigidity at the portions where the

marker portions

120 and 220 are disposed. Further, the shaft portion 110 of the

catheters

100 and 200 is provided with a reinforcing body 114 and has a certain degree of rigidity. Therefore, as shown in FIG. 7, the proximal end is more than the portion where the

marker portions

120 and 220 are disposed. It bends gently in a predetermined range B1 on the side. That is, the predetermined range B1 is a region that is a starting point of bending of the

catheters

100 and 200. The region B1 that is the starting point of bending is the same size as the catheter 100 according to the embodiment and the catheter 200 according to the comparative example.

In the catheter 100 according to the embodiment, since the marker portion 220 is disposed on the distal end side relative to the catheter 200 according to the proportionality, the region B1 serving as a starting point of bending is formed on the distal end side with respect to the catheter 200.

Here, it is assumed that the abutment test is performed on the catheter 200 according to the embodiment and the catheter 200 according to the embodiment.

As shown in FIG. 8 (A), the abutment test is a method in which a portion separated by a predetermined distance (for example, 3 mm to 10 mm) from the most distal end of the catheter is fixed with a jig T1, and a predetermined measuring instrument is used. This is a test for measuring the maximum abutting resistance value (abutting load) when the distal end of the catheter is abutted against the silicone plate T2 at an abutting speed (for example, 5 to 100 mm / min).

As described above, in the catheter 100 according to the embodiment, as shown in FIG. 7, the region B <b> 1 serving as a starting point of bending is formed on the distal side of the catheter 200 as compared to the catheter 200 according to the proportionality. For this reason, as shown in FIG. 8B, when the distal end of the catheter is abutted against the plate T2, the distal end portion of the catheter 100 is more easily bent than the comparative catheter 200. As a result, the abutment resistance of the catheter 100 is lower than that of the catheter 200 that is proportional to each other, so that the flexibility (easy to bend) of the distal end portion of the catheter 100 is increased.

Also, the first region A1 of the catheter 100 is formed with a higher resin content per unit volume than the second region A2. For this reason, the collision energy when the catheter 100 is abutted against the plate T2 can be changed to the deformation energy of the resin. Since the resin absorbs the impact when the catheter 100 is abutted against the plate T2, it is possible to suppress an increase in abutting resistance and an increase in the rigidity of the distal end of the catheter 100 due to the marker portion 120 being arranged at the forefront. .

As described above, the catheter 100 according to the present embodiment is formed of a tubular shaft portion 110 having a distal end portion 110d formed of resin, and a metal that is disposed on the distal end portion 110d of the shaft portion 110 and has radiopacity. And a ring-shaped marker portion 120. The distal end portion 110d of the shaft portion 110 is disposed on the proximal end side with respect to the tapered portion 111 that is formed in a tapered shape that includes the most distal end and the outer diameter of the shaft portion 110 tapers toward the distal end side, And a constant outer diameter portion 112 having a substantially constant outer diameter along the axial direction. The marker part 120 has a marker tip part 121 arranged on the taper part 111 so as to follow the outer shape of the taper part 111, and a marker base end part 125 arranged on the constant outer diameter part 112. 1st area | region A1 comprised by the taper part 111 and the marker front-end | tip part 121 is formed with the resin content rate per unit volume higher than 2nd area | region A2 comprised by the outer diameter fixed part 112 and the marker base end part 125. Has been.

According to the catheter 100, since the distal end portion 110d of the shaft portion 110 has the tapered portion 111, the insertion property of the catheter 100 into the living body lumen can be improved. In addition, since the marker tip 121 is arranged so as to follow the outer shape of the tapered portion 111, the most advanced position of the catheter 100 can be grasped more accurately by observing the marker 120 under radioscopy. Can do. In addition, since the first region A1 is formed with a higher resin content per unit volume than the second region A2, the most advanced rigidity of the catheter 100 can be reduced. Moreover, since the marker part 120 can be arrange | positioned more distally of the catheter 100 by the said structure, the origin of bending of the catheter 100 can be made more distal. Thereby, the bendability (flexibility) of the distal end portion of the catheter 100 can be improved. Therefore, according to the catheter 100, it is possible to improve the state-of-the-art visibility of the catheter 100 under radioscopy while ensuring the safety of the catheter 100.

Also, the marker distal end 121 has a notch 122 that is notched from the leading edge toward the proximal end. Of the distal end portion of the catheter 100, the portion where the cutout portion 122 is disposed is made of only resin. For this reason, the softness | flexibility of the front-end | tip part of the catheter 100 can be improved.

Further, the notch 122 has a length W1 that gradually decreases in the circumferential direction from the most distal end toward the base end side. Thereby, the protrusion part 123 which is a part left by being cut out by the notch part 122 is formed in a triangular shape in which the length W2 along the circumferential direction gradually increases from the front end toward the base end side. Therefore, the strength of the marker tip 121 can be maintained because the protrusion 123 does not have a portion (necking) that sharply narrows.

Moreover, since the marker tip 121 has a plurality of notches 122 along the circumferential direction, the flexibility of the tip of the catheter 100 can be improved.

Next, with reference to FIGS. 9 to 11, a modified example of the marker portion of the above-described embodiment will be described. In the description of each modification, the same reference numerals are given to the same configurations as those in the above-described embodiment, and the description thereof is omitted. Further, points not particularly mentioned in each modification can be configured in the same manner as in the above-described embodiment.

<Modification 1>
FIG. 9 is a side view of the marker unit 320 according to the first modification.

Similar to the embodiment described above, the marker portion 320 according to the first modification example is continuous with the marker distal end portion 321 and the proximal end of the marker distal end portion 321 and has a marker proximal end portion having a constant outer diameter along the axial direction. 325. The marker tip 321 has a notch 322 and a protrusion 323.

As shown in FIG. 9, the marker portion 320 according to the modified example 1 is different from the above-described embodiment in that the shape of the protruding portion 323 is U-shaped.

The notch 322 has a length W21 that gradually decreases in the circumferential direction from the most distal end toward the base end side, as in the above-described embodiment.

The same effect as that of the above-described embodiment is also exhibited in the catheter including the marker unit 320 according to this modification.

<Modification 2>
FIG. 10 is a side view of the marker unit 420 according to the second modification.

Similar to the embodiment described above, the marker portion 420 according to the modified example 2 is continuous with the marker distal end portion 421 and the proximal end of the marker distal end portion 421, and has a marker proximal end portion having a constant outer diameter along the axial direction. 425. The marker tip 421 has a notch 422.

As shown in FIG. 10, the marker unit 420 according to the modified example 2 includes a plurality of cutout portions 422 along the circumferential direction, and at least two cutout portions 422 among the plurality of cutout portions 422 are The present embodiment is different from the above-described embodiment in that it has different shapes.

The same effect as that of the above-described embodiment is exhibited also in the catheter including the marker unit 420 according to this modification.

In addition, since at least two notches 422 among the plurality of notches 422 have different shapes, the directionality in the circumferential direction can be grasped more accurately under radioscopy.

<Modification 3>
FIG. 11A is a side view of the marker portion 520 according to the modification 3, and FIG. 11B is an axial sectional view of the marker portion 520.

Similar to the embodiment described above, the marker portion 520 according to the modification 3 is continuous with the marker distal end portion 521 and the proximal end of the marker distal end portion 521, and has a marker proximal end portion having a constant outer diameter along the axial direction. 525.

As shown in FIG. 11A, the marker part 520 according to the modification 3 is different from the above-described embodiment in that it does not have a notch part.

As shown in FIG. 11B, the thickness t52 of the marker base end portion 525 is formed to be substantially constant along the axial direction. A thickness t51 of the marker distal end portion 521 is formed so as to gradually decrease from the distal end of the marker base end portion 525 toward the distal end side. That is, the thicknesses t51 and t52 of the marker portion 520 are formed so as to decrease from the proximal end toward the distal end. For this reason, the first region A1 where the marker distal end portion 521 is disposed in the catheter can be formed with a higher resin content per unit volume than the second region A2 where the marker proximal end portion 525 is disposed.

The same effect as that of the above-described embodiment is also exhibited in the catheter including the marker unit 520 according to this modification.

The thicknesses t51 and t52 of the marker portion 520 are formed so as to decrease from the proximal end toward the distal end. For this reason, when the marker part 520 is arrange | positioned at a catheter, the softness | flexibility of the front-end | tip part of a catheter can be improved. Moreover, since the rigidity of the distal end portion of the catheter can be gradually changed, a sudden change in rigidity can be suppressed.

As mentioned above, although the catheter which concerns on this invention was demonstrated through embodiment, this invention is not limited only to each structure demonstrated in the specification, It can change suitably based on description of a claim. It is.

The shape of the marker portion is not limited to the above-described embodiment or modification as long as the first region can be formed with a higher resin content per unit volume than the second region. For example, the shape of the distal end portion of the protruding portion 123 is not limited to the above. For example, as shown in FIG. 12, the shape of the notched portion 622 of the marker portion 620 may be a quadrangle. Moreover, as shown in FIG. 13, you may have the shape where the base end of the notch part 722 of the marker part 720 and the front-end | tip of the protrusion part 723 were sharp. Further, as shown in FIGS. 14 and 15, the lengths W31 and W41 along the circumferential direction of the

cutout portions

822 and 922 of the marker portion 820 have portions that gradually decrease from the base end side toward the forefront. Also good. In addition, the tips of the protruding

portions

823 and 923 of the

marker portions

820 and 920 may have a flat shape in the direction perpendicular to the axis.

Further, as shown in FIG. 16, the tip of the protruding portion 123a of the marker portion 120a is curved in an arc shape radially inward so as to follow the outer shape of the tapered portion of the shaft portion (broken line in FIG. 16). May be included). Thereby, the risk of damaging the inner wall of the living body lumen can be greatly reduced.

Further, as the catheter to which the present invention is applied, in the above-described embodiment, the microcatheter has been described as an example. However, the present invention is not limited to this. For example, a balloon catheter, a self-expandable stent delivery system, a balloon expandable stent delivery The present invention can be applied to systems, contrast catheters, ultrasonic catheters, atherectomy catheters, endoscope catheters, drug solution administration catheters, and the like.

This application is based on Japanese Patent Application No. 2017-042988 filed on March 7, 2017, the disclosure content of which is incorporated by reference in its entirety.

100 catheters,
110 shaft part,
110d The tip of the shaft part,
111 taper part,
112 constant outer diameter part,
113 Inner layer,
114 reinforcements,
115 outer layer,
120, 320, 420, 520, 620, 720, 820, 920 marker part,
121, 521 Marker tip,
122, 322, 422, 522, 622, 722, 822 Notch,
123, 623, 723, 823, 923 protrusion,
125, 525 marker proximal end,
130 catheter hub,
200 paired catheters,
220, a marker part that is proportional,
A contrast area,
A1 first region,
A2 second region,
L Length along the axial direction of the marker part (L1 + L2),
Length along the axial direction of the L1 marker tip,
Length along the axial direction of the L2 marker base end,
W1, W21, W31, W41 Length along the circumferential direction of the notch,
W2 Length along the circumferential direction of the protrusion.

Claims

A catheter having a tubular shaft portion having a distal end portion formed of a resin, and a ring-shaped marker portion disposed at the distal end portion of the shaft portion and formed of a radiopaque metal,
The distal end portion of the shaft portion includes a tapered portion formed in a tapered shape including the most distal end and an outer diameter of the shaft portion tapering toward the distal end side, and is disposed closer to the proximal end side than the tapered portion. An outer diameter constant portion having a substantially constant outer diameter along the direction,
The marker portion has a marker distal end portion disposed on the tapered portion so as to follow the outer shape of the tapered portion, and a marker base end portion disposed on the constant outer diameter portion,
The first region constituted by the tapered portion and the marker distal end portion has a higher resin content per unit volume than the second region constituted by the constant outer diameter portion and the marker proximal end portion.
The catheter according to claim 1, wherein the distal end portion of the marker has a cutout portion cut out from the most distal end toward the proximal end side.
The catheter according to claim 2, wherein the length of the cutout portion along the circumferential direction gradually decreases from the most distal end toward the proximal end side.
The catheter according to claim 2 or 3, wherein the tip of the marker has a plurality of notches along a circumferential direction.
The catheter according to claim 4, wherein at least two of the cutout portions have different shapes.
The catheter according to any one of claims 1 to 5, wherein the thickness of the marker portion decreases from the proximal end toward the distal end side.