JP2007236472A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter capable of arranging a marker excellent in an imaging property at an accurate position without damaging the original performance of the catheter. <P>SOLUTION: The catheter 1 has a catheter main body comprising an inner layer 3, an outer layer 4 formed on the outer peripheral side of the inner layer 3 and a coil 5 installed between the inner layer 3 and the outer layer 4 and composed by helically winding one continuous wire body. The coil 5 is provided with a plurality of densely wound parts 51 where the pitch of helix is small and a sparsely wound parts 52 where the pitch of the helix is larger than that in the densely wound parts 51 respectively and the densely wound parts 51 and the sparsely wound parts 52 are alternately formed along the longitudinal direction of the catheter main body 2. The coil 5 is constituted of a radiopaque metal material whose Vickers hardness is less than 300, and when the catheter main body 2 is inserted to a blood vessel or the like under fluoroscopy, the densely wound parts 51 function as an X-ray imaging marker. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a medical catheter, for example, a catheter used by being inserted into a body cavity such as a blood vessel.

  PTCA (Percutaneous Transluminal Coronary Angioplasty), which expands a stenosis (lesion) of a blood vessel such as a coronary artery with a balloon, or expands the stenosis by placing a stent (reopening) Prior to that, a penetrating catheter that penetrates the stenosis in advance is used. In addition, for the treatment, it is necessary to determine the optimum balloon length and stent length according to the range in which the stenosis has occurred. For this purpose, the function of measuring the length of the stenosis portion with respect to the penetration catheter or the like Is desired.

  Also, when a detachable coil (eg Boston: GDC) used to treat a cerebral aneurysm is placed in the lesion, confirm that the detachable part between the coil and the pusher is exposed from the tip of the microcatheter before detaching. The operation is performed by confirming the fact that the marker on the pusher is in contact with a marker arranged at a predetermined position on the base side of the tip of the microcatheter.

  As a response to such a problem, a catheter is known in which markers composed of metal chips are arranged at regular intervals along the longitudinal direction of the catheter (see, for example, Patent Document 1). However, in this catheter, since a plurality of metal tips are provided in the catheter, it takes time and effort to manufacture, and the structure is complicated, and in particular, the outer shape of the portion where the marker is installed swells in a hump shape. Intravascular passage is poor. Furthermore, since the rigidity (bending rigidity and torsional rigidity) of the part where the metal tip of the catheter is present is extremely increased compared to the part where it does not exist, the kink (bending) is likely to occur in the part with low rigidity, and the part with high rigidity However, there is a drawback that sufficient curvature cannot be obtained, and uniform and stable bending performance cannot be obtained over the entire length of the catheter.

  Moreover, like the catheter described in Patent Document 1, in order to arrange a resin containing a high concentration of barium sulfate in the outer layer of the catheter at a constant interval, there is a possibility that the arrangement interval may be out of order in the process of thermal processing, Such a marker is inferior in radiopacity to a metal marker and has a problem that a clear X-ray fluoroscopic image cannot be obtained.

Japanese Utility Model Publication No. 5-48953

  The objective of this invention is providing the catheter which can arrange | position the marker excellent in contrast (X-ray opacity) in an exact position, without impairing the catheter's original performance.

Such an object is achieved by the present inventions (1) to (14) below.
(1) A catheter body having an inner layer and an outer layer formed on the outer peripheral side of the inner layer, and one continuous linear body between the inner layer and the outer layer at least at the distal end of the catheter body A catheter in which a coil formed by spirally winding is installed,
The coil is formed by alternately forming a densely wound portion having a small helical pitch and a loosely wound portion having a larger helical pitch than the densely wound portion along the longitudinal direction of the catheter body,
And the said coil is comprised with the metal material which has radiopacity whose Vickers hardness is less than 300,
The catheter, wherein the densely wound portion functions as an X-ray contrast marker when the catheter body is inserted into a living body under fluoroscopy.

  (2) The catheter according to (1), wherein a diameter of the linear body constituting the coil is 0.01 to 0.15 mm.

  (3) The catheter according to (1) or (2), wherein the linear body constituting the coil is configured by a stranded wire obtained by twisting a plurality of strands.

  (4) The catheter according to any one of (1) to (3), wherein the coil is made of a metal material containing at least one of tantalum, gold, silver, platinum, iridium, and palladium. .

  (5) The catheter according to any one of (1) to (4), wherein a distal end of the coil is configured by the densely wound portion.

  (6) The catheter according to any one of (1) to (5), wherein the coil includes a plurality of densely wound portions that are intermittently formed at substantially equal intervals along a longitudinal direction.

(7) When the bending elastic modulus of the densely wound portion of the coil is A [kgf / cm ² ] and the bending elastic modulus of the loosely wound portion is B [kgf / cm ² ], the value of B / A is 0. The catheter according to any one of (1) to (6), wherein the catheter is 3 to 3.0.

  (8) The catheter according to any one of (1) to (7), wherein the inner layer and / or the outer layer has a portion whose rigidity changes in the longitudinal direction of the catheter body.

  (9) The catheter according to any one of (1 to (8) above, wherein a tubular radiopaque tip is installed on the distal end side of the coil.

  (10) The catheter according to any one of (1) to (9), further including a reinforcing member that increases the rigidity of the catheter body on the proximal end side of the coil.

  (11) The catheter according to (10), wherein the reinforcing member has a coil shape or a mesh shape installed between the inner layer and the outer layer.

  (12) The catheter according to (10) or (11), wherein the reinforcing member is made of stainless steel.

  (13) The catheter according to any one of (1) to (12), wherein the catheter body has a lumen through which a guide wire can be inserted inside the inner layer.

  (14) The catheter according to any one of (1) to (13), wherein the catheter is a stenosis penetration catheter or a microcatheter.

  According to the present invention, for example, a marker having excellent X-ray contrast properties can be easily provided as compared with an X-ray contrast marker made of a nonmetallic X-ray contrast material such as barium sulfate.

  In addition, since a densely wound portion is provided at a predetermined portion of one continuous coil and used as an X-ray contrast marker, a desired number of markers can be easily and accurately provided.

  In addition, since one continuous coil is used, changes in the longitudinal rigidity (bending rigidity and torsional rigidity) of the catheter body can be reduced, and stable catheter bending performance can be obtained.

  In addition, when all the X-ray contrast markers are configured with metal chips as in the past, the resin layer coated on the markers protrudes in a bump shape, and the outer diameter enlarges locally at this part. In the present invention, such inconvenience is solved, and an unintentional change in the outer diameter of the catheter body is prevented. Therefore, the insertion operation of the catheter into the living body lumen can be performed more easily and safely, and the burden on the patient is reduced.

  In addition, the catheter of the present invention can obtain the above-described effects without impairing the characteristics originally required for the catheter such as pushability, torque transmission, and kink resistance. Since the catheter is excellent in pushability, torque transmission, and the like, when the present invention is applied to a catheter for penetrating a stenosis, for example, the stenosis can be easily, quickly and reliably penetrated.

  Further, in the present invention, by using a metal material having a Vickers hardness of less than 300 as a constituent material of the coil, the inner layer is damaged at the boundary between the densely wound portion and the loosely wound portion when the catheter body is manufactured. While preventing the strength reduction of the catheter main body resulting from this, the disorder of coil pitch can be prevented, more suitable X-ray contrast property can be obtained, and the softness | flexibility of the front-end | tip part of a catheter main body can fully be ensured.

  In addition, when the present invention is applied to a microcatheter or the like, excellent peripheral reachability can be obtained.

  Hereinafter, the catheter of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a longitudinal sectional view showing a first embodiment of the catheter of the present invention. In the following description, the left side in FIG. 1 is referred to as “tip”, and the right side is referred to as “base end”.

  A catheter 1 shown in FIG. 1 is used by being inserted into a living body lumen (hereinafter referred to as “blood vessel”) such as a blood vessel and a bile duct, for example, and caused by a lesion (hereinafter referred to as a stenosis portion). And the occlusion portion is generically referred to as a “stenosis portion”).

  As shown in FIG. 1, this catheter 1 has a catheter body 2 having flexibility. The catheter body 2 is an elongated member having a tubular shape, and a lumen (inner lumen) 23 through which, for example, a guide wire (not shown) is inserted is formed. The lumen 23 is formed continuously from the proximal end to the distal end of the catheter body 2.

  The lumen 23 may be used for purposes other than insertion of the guide wire, for example, for sucking a body fluid or injecting a chemical solution.

  The catheter body 2 includes a proximal end portion (not shown), a distal end portion 21, and an intermediate portion 22 between the proximal end portion and the distal end portion 21. Components (not shown) such as a hub and a connector are connected to the base end portion.

  The total length of the catheter body 2 is not particularly limited, but is preferably about 500 to 1900 mm, and more preferably about 800 to 1600 mm.

  The outer diameter of the catheter body 2 is not particularly limited, but is preferably about 0.5 to 2.0 mm, more preferably about 0.6 to 1.2 mm. In addition, the outer diameter of the catheter body 2 may change along the longitudinal direction, and for example, there may be a portion where the outer diameter continuously decreases toward the distal end direction.

  The inner diameter of the catheter body 2, that is, the diameter of the lumen 23 is not particularly limited, but is preferably about 0.3 to 1.5 mm, and more preferably about 0.4 to 0.9 mm.

  Such a catheter body 2 includes an inner layer 3 positioned on the inner peripheral side, an outer layer 4 formed on the outer peripheral side of the inner layer 3, and a coil 5 installed (embedded) between the inner layer 3 and the outer layer 4. Have. The tip of the coil 5 is located near the tip of the catheter body 2.

  The constituent material of the inner layer 3 is not particularly limited. For example, a fluorine-based resin such as PTFE (polytetrafluoroethylene), a polyolefin such as polyamide, polyimide, polyethylene, and polypropylene, a polyester such as polyethylene terephthalate and polybutylene terephthalate, a polyurethane, and a polystyrene , Polycarbonate, silicone resin, polyetherimide, and the like. Among these, a low friction material such as a fluorine-based resin is preferable. Thereby, since the friction coefficient of the inner surface of the lumen 23 is reduced, when a guide wire is inserted into the lumen 23, the frictional resistance (sliding resistance) thereof is reduced, and the guide wire can be inserted more smoothly. .

  The thickness of the inner layer 3 is not particularly limited, but the average thickness is preferably about 0.01 to 0.20 mm, and more preferably about 0.03 to 0.06 mm.

  The constituent material of the outer layer 4 is not particularly limited. For example, various thermoplastic elastomers such as polyurethane elastomer, polyester elastomer, and polyamide elastomer, polyolefins such as polyamide, polyimide, polyethylene, and polypropylene, polyurethane, silicone resin, polyethylene terephthalate, and polybutylene. Polyesters such as terephthalate and the like, or a mixture obtained by mixing two or more of these may be mentioned. Among these, materials having relatively high flexibility such as various thermoplastic elastomers, polyurethanes, and silicone resins are preferable. Thereby, the inner surface of the blood vessel into which the catheter body 2 is inserted is not damaged, and the safety is further improved.

  The thickness of the outer layer 4 is not particularly limited, but the average thickness is preferably about 0.02 to 0.3 mm, and more preferably about 0.05 to 0.2 mm.

  The outer layer 4 may be configured by combining (connecting) a plurality of tubes having different conditions such as rigidity (hardness) and outer diameter. In the illustrated embodiment, the former is the latter in the portion on the distal end side and the portion on the proximal end side of the boundary portion 41 of the outer layer 4 with the boundary portion 41 between the distal end portion 21 and the intermediate portion 22 as a boundary. It is said that the rigidity (hardness) is smaller than that. Thereby, the softness | flexibility of the front-end | tip part 21 can be improved rather than the intermediate part 22 of the catheter main body 2, and the operativity and safety | security of the catheter 1 improve more.

  It should be noted that such a portion where the stiffness changes (a portion where the stiffness decreases toward the tip) can be applied to the inner layer 3 in the same manner, and can also be applied to each of the inner layer 3 and the outer layer 4. it can.

  In the present embodiment, the inner layer 3 and the outer layer 4 are in close contact except for a portion where the linear body of the coil 5 exists. However, the present invention is not limited to this. For example, an intermediate layer is provided between the inner layer 3 and the outer layer 4, and the coil 5 is embedded in the intermediate layer or between the intermediate layer and the inner layer 3. Alternatively, the coil 5 may be installed (embedded) between the intermediate layer and the outer layer 4.

  The coil 5 is formed by spirally winding a single continuous linear body (elementary wire), and is made of a material that satisfies the following conditions.

  The coil 5 includes a densely wound portion 51 having a small helical pitch and a loosely wound portion 52 having a helical pitch larger than that of the densely wound portion 51, and the densely wound portion 51 and the loosely wound portion 52 are long in the length of the catheter body 2. It is formed alternately along the direction. In particular, the coil 5 has a plurality of closely wound portions 51 along the longitudinal direction, and these are preferably formed intermittently at almost equal intervals (see FIG. 1). In this case, although the space | interval of adjacent densely wound part 51 is not specifically limited, For example, it shall be about 5-30 mm. This interval constitutes one scale (minimum unit of scale) when measuring the length of the stenosis or the like.

  Here, the densely wound portion 51 is preferably in a state where adjacent linear bodies are in contact with each other or in close proximity. Further, in the loosely wound portion 52, for example, the pitch of the linear body wound spirally can be about 2 to 25 times the diameter of the linear body.

  Further, the boundary part (transition part) 53 between the densely wound part 51 and the loosely wound part 52 may change stepwise or continuously.

  The constituent material of the coil 5 (the constituent material of the linear body) is a metal material having radiopacity. Thereby, X-ray contrast property can be exhibited. In particular, when the catheter body 2 is inserted into a living body (into a blood vessel) under X-ray fluoroscopy, the tightly wound portion 51 of the coil 5 functions as an X-ray contrast marker and the position thereof can be grasped.

  Furthermore, the constituent material of the coil 5 is a metal material having a Vickers hardness of less than 300, preferably 250 or less, more preferably 20 to 200, among metal materials having radiopacity.

  A preferable metal material satisfying such conditions includes, for example, a metal material (single metal or alloy) containing at least one of tantalum, gold, silver, platinum, iridium, and palladium. Preferable examples of the alloy include 18 gold and platinum-iridium alloy.

  The reason why a metal material having a Vickers hardness of 300 or more is excluded from the present invention is as follows.

  When manufacturing the catheter body 2, for example, when the coil 5 is wound around the inner layer 3, the inner layer 3 is brought into contact with a die (hereinafter referred to as “head”) that discharges a linear body (element wire) constituting the coil 5. Further, the coil 5 is wound around the inner layer 3 by moving the head in the axial direction of the inner layer 3 while rotating the inner layer 3 (in this case, the rotational speed of the inner layer 3 and the ejection from the linear die) The speed is constant, and the coil pitch is controlled by the moving speed of the head.) When a hard metal material having a Vickers hardness of 300 or more, such as tungsten, is used as the material constituting the coil 5, first of all In addition, the inner layer 3 is damaged at a location where the coil pitch changes (changes from the densely wound portion 51 to the loosely wound portion 52) (= the boundary portion 53), that is, where the head speed changes abruptly. There is Jill risk, due to this, the strength of the catheter body 2 may be decreased. Secondly, the head is damaged by the linear body constituting the coil 5, the coil pitch is disturbed due to this, the proper X-ray contrast property cannot be obtained, and the distal end portion 21 is flexibly bent. May be disturbed. Further, the inner layer 3 may be contaminated or the inner layer 3 may be damaged due to friction with the damaged head.

  In addition, when the catheter of the present invention is applied to a microcatheter, a doctor or the like may shape (reshape) the tip 21 in a desired shape in advance, but the coil 5 incorporated in the tip 21 is too hard. Thus, there is a drawback that the shaping is difficult or difficult to achieve the target shape. Therefore, in the present invention, the metal material constituting the coil 5 has a Vickers hardness of less than 300 as described above.

  The diameter (average) of the linear body constituting the coil 5 is preferably about 0.01 to 0.15 mm, and more preferably about 0.02 to 0.10 mm. If the diameter of the linear body is too large, the flexibility of the distal end portion 21 of the catheter body 2 may be insufficient, and the diameter of the catheter body 2 may be hindered. If the diameter of the linear body is too small, the X-ray contrast property in the densely wound portion 51 may be lowered depending on other conditions such as the material characteristics.

  In addition, although the diameter of a linear body may be the same over the full length of the coil 5, there may exist a different location. For example, in order to reduce the outer diameter near the distal end of the catheter body 2, the diameter of the linear body corresponding to that portion may be reduced.

  Moreover, the linear body which comprises the coil 5 may be the twisted wire which twisted the some strand. In the case of a stranded wire, two or more different types of metal materials can be twisted, so that the advantages (for example, hardness and X-ray contrast properties) of each metal material can be combined and drawn out.

As described above, the coil 5 includes the densely wound portion 51 and the loosely wound portion 52, and the bending elastic modulus of the densely wound portion 51 is A [kgf / cm ² ] and the bending elastic modulus of the loosely wound portion 52 is B. When [kgf / cm ² ] is set, the value of B / A is preferably 0.3 to 3.0, and more preferably 0.5 to 2.0. If the value of B / A is out of the above range, the difference in bending rigidity between the densely wound portion 51 and the loosely wound portion 52 becomes large, and there is a risk that kinks (bends) are likely to occur near the boundary portion 53 of the catheter body 2. is there.

  As shown in FIG. 1, the distal end of the coil 5 is composed of a densely wound portion 51, and this densely wound portion 51 is located near the distal end of the catheter body 2. Thereby, the close winding part 51 of the front-end | tip of the coil 5 functions as an X-ray contrast marker, and the position of the front-end | tip of the catheter main body 2 can be grasped | ascertained.

  Thus, when the X-ray contrast marker in the vicinity of the distal end of the catheter body 2 is configured by the densely wound portion 51, the X-ray impermeable tip 6 is provided as a separate member as in the second embodiment (FIG. 2) described later. Compared to the configuration described above, the vicinity of the distal end of the catheter body 2 can be made more flexible, and also contributes to a reduction in diameter.

  Further, as described above, a plurality of closely wound portions 51 functioning as X-ray contrast markers are intermittently formed at substantially equal intervals along the longitudinal direction of the catheter body 2. And the space | interval (distance) between the adjacent closely wound parts 51 is known. Thus, when the catheter body 2 is passed through the stenosis portion of the blood vessel under fluoroscopy, each closely wound portion (X-ray contrast marker) 51 functions as a scale, and the length of the stenosis portion is measured (confirmed). be able to. Then, based on the measured length of the stenosis, it is possible to determine the appropriate length of the balloon or stent used in the subsequent stenosis expansion treatment.

  In the illustrated embodiment, the cross-sectional shape of the linear body of the coil 5 is circular, but is not limited thereto, and may be, for example, an ellipse, a rectangle (square, rectangle, trapezoid, rhombus, etc.), etc. It may be a flat plate.

  In this embodiment, since the closely wound portion 51 of the coil 5 is used as an X-ray contrast marker, it is not necessary to install a separate member (a dedicated X-ray contrast chip or the like), and the catheter 1 can be easily manufactured. At the same time, it contributes to reducing the diameter and the outer diameter of the catheter body 2.

  In particular, as shown in FIG. 1, in the coil 5 installed between the inner layer 3 and the outer layer 4, both the densely wound portion 51 and the loosely wound portion 52 have an inner layer 3 and / or an outer layer between adjacent linear bodies. Since the inner layer 3 and the outer layer 4 are in close contact with each other so that the constituent material 4 enters, the outer diameter does not increase in a part of the catheter body 2 (particularly, the portion where the densely wound portion 51 exists). The uniform outer diameter of the catheter body 2 is maintained.

As described above, the densely wound portion 51 has X-ray contrast properties, but is not limited to this, and it is preferable to exhibit contrast properties in other contrast systems such as MRI. It can also be used in other imaging systems such as MRI.
A reinforcing member 7 for increasing the rigidity of the catheter main body 2 is embedded in the intermediate portion 22 (base end side of the coil 5) of the catheter main body 2. Similar to the coil 5, the reinforcing member 7 is installed (embedded) between the inner layer 3 and the outer layer 4.

  As in the second embodiment (FIG. 2) to be described later, the coil 5 may be installed also in the intermediate portion 22, but the constituent material of the coil 5 is relatively inelastic and rigid and has a sufficient reinforcing effect. In some embodiments, the reinforcing member 7 is provided separately from the coil 5. Thereby, moderate rigidity (bending rigidity, torsional rigidity) is obtained in the catheter body 2, and operability such as pushability and torque transmission is improved. As a result, the catheter 1 more easily penetrates the stenosis. Will be able to.

  Although it does not specifically limit as a form of the reinforcement member 7, As shown in FIG. 1, a coil-shaped thing is mentioned. In this case, it is preferable that the coil wire has a strip shape (a cross-sectional shape is a rectangle: also called a blade shape). Moreover, as another preferable form of the reinforcing member 7, a mesh-like thing (braided body) is mentioned.

  As a constituent material of the reinforcing member 7, for example, stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, all types of SUS, etc.) , Co-Ni-Cr alloys, Co-Ni-Cr-Mo alloys and other cobalt alloys, Ni-Ti alloys, Ni-Al alloys, Cu-Zn-X alloys (where X is Be, Si, Sn) And various metal materials such as alloys (including superelastic alloys) exhibiting pseudoelasticity such as at least one of Al, Ga, and the like, among which stainless steel is preferable.

  The outer surface of the catheter body 2 is preferably provided with a surface layer (not shown) made of a hydrophilic material (hydrophilic polymer). Since this hydrophilic material exhibits lubricity when wet, it can be inserted more smoothly and easily when the catheter body 2 is inserted into the blood vessel, contributing to improved operability and safety. The burden can be reduced.

  The hydrophilic material constituting the surface layer is not particularly limited, and examples thereof include a copolymer of methyl vinyl ether and maleic anhydride, a copolymer of dimethylacrylamide and glycidyl methacrylate, and the like.

Next, an example of the manufacturing method of the catheter 1 is demonstrated.
First, the inner layer 3 formed into a tube shape is prepared, and the coil-shaped reinforcing member 7 is formed by winding the strands of the reinforcing member 7 around the outer peripheral surface of the intermediate portion 22 of the inner layer 3. The wire of the coil 5 is wound around the outer peripheral surface of 21. The specific winding method of the coil 5 and the reinforcing member 7 (hereinafter referred to as “coil 5 etc.”) is as described above.

  Next, the outer layer 4 is formed outside the coil 5 and the like. Specifically, for example, a sheet material or a tubular body for forming the outer layer 4 is placed on the outer peripheral portion of the coil 5 or the like, and this is heated to adhere to the inner layer 3 and the coil 5 or the like.

  The formation of the outer layer 4 is not limited to the method described above, and may be performed by a coating method such as coating, dipping, or spraying.

  According to such a manufacturing method, the inner layer 3 and the outer layer 4 are in close contact so that the constituent materials of the inner layer 3 and / or the outer layer 4 enter between adjacent linear bodies in the densely wound portion 51 and the loosely wound portion 52. Therefore, there is no local increase in the outer diameter (particularly at the portion where the tightly wound portion 51 of the catheter body 2 is present), and the outer diameter of the catheter body 2 can be made uniform.

Second Embodiment
FIG. 2 is a longitudinal sectional view showing a second embodiment of the catheter of the present invention. Hereinafter, although the catheter of 2nd Embodiment is demonstrated based on FIG. 2, the description is abbreviate | omitted about the matter similar to 1st Embodiment mentioned above, and it demonstrates centering around a different point.

  As shown in FIG. 2, in the catheter 1 of the second embodiment, the coil 5 is installed so as to straddle both the intermediate portion 22 and the distal end portion 21 of the catheter body 2. In this case, in the intermediate portion 22, the coil 5 is configured by a loosely wound portion 52.

  The distal end of the coil 5 is composed of a loosely wound portion 52, and a tubular (ring-shaped) X-ray impermeable tip 6 is disposed closer to the distal end side than the distal end of the coil 5 (the inner layer 3 and the outer layer). 4). The radiopaque tip 6 functions as an X-ray contrast marker at the distal end of the catheter body 2. As a constituent material of the X-ray opaque chip 6, the same material as that of the coil 5 described above can be used.

  The installation interval between the closely wound portion 51 located on the most distal end side of the coil 5 and the X-ray impermeable tip 6 is set substantially equal to the installation interval between the adjacent closely wound portions 51. Thereby, similarly to the first embodiment, each closely wound portion 51 and the X-ray impermeable tip 6 function as a scale, and the length of the constricted portion or the like can be measured.

  In addition, also about the catheter 1 of this embodiment, the reinforcement member 7 similar to the above can be installed in the intermediate part 22. FIG. The radiopaque tip 6 is not limited to a tubular shape, and may be a coil shape, for example.

  The catheter of the present invention is not limited to the catheter for penetrating a stenosis portion shown in each embodiment, and can be applied to, for example, a microcatheter. Here, the microcatheter is inserted into a relatively thin blood vessel such as an intracerebral blood vessel, and the outer diameter of the catheter body 2 is preferably about 0.6 to 1.0 mm.

  The present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and the configuration of each part can be replaced with any configuration that can exhibit the same function. In addition, an arbitrary configuration may be added.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the catheter of this invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the catheter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Catheter 2 Catheter main body 21 Tip part 22 Intermediate part 23 Lumen 3 Inner layer 4 Outer layer 41 Boundary part 5 Coil 51 Closely wound part 52 Loosely wound part 53 Boundary part 6 X-ray impermeable tip 7 Reinforcing member

Claims (14)

A catheter body having an inner layer and an outer layer formed on the outer peripheral side of the inner layer, and at least at a distal end portion of the catheter body, one continuous linear body is spirally formed between the inner layer and the outer layer; A catheter with a coil wound around it,
The coil is formed by alternately forming a densely wound portion having a small helical pitch and a loosely wound portion having a larger helical pitch than the densely wound portion along the longitudinal direction of the catheter body,
And the said coil is comprised with the metal material which has radiopacity whose Vickers hardness is less than 300,
The catheter, wherein the densely wound portion functions as an X-ray contrast marker when the catheter body is inserted into a living body under fluoroscopy.   The catheter according to claim 1, wherein a diameter of a linear body constituting the coil is 0.01 to 0.15 mm.   The catheter according to claim 1 or 2, wherein the linear body constituting the coil is composed of a stranded wire obtained by twisting a plurality of strands.   The catheter according to any one of claims 1 to 3, wherein a constituent material of the coil is made of a metal material containing at least one of tantalum, gold, silver, platinum, iridium, and palladium.   The catheter according to any one of claims 1 to 4, wherein a distal end of the coil is configured by the closely wound portion.   The catheter according to any one of claims 1 to 5, wherein the coil is formed such that a plurality of the closely wound portions are intermittently formed at substantially equal intervals along a longitudinal direction. When the bending elastic modulus of the densely wound portion of the coil is A [kgf / cm ² ] and the bending elastic modulus of the loosely wound portion is B [kgf / cm ² ], the value of B / A is 0.3 to The catheter according to any one of claims 1 to 6, which is 3.0.   The catheter according to any one of claims 1 to 7, wherein the inner layer and / or the outer layer includes a portion whose rigidity changes in the longitudinal direction of the catheter body.   The catheter according to any one of claims 1 to 8, wherein a tubular radiopaque tip is installed on a distal end side of the coil.   The catheter according to any one of claims 1 to 9, further comprising a reinforcing member for increasing the rigidity of the catheter body on a proximal end side of the coil.   The catheter according to claim 10, wherein the reinforcing member has a coil shape or a mesh shape installed between the inner layer and the outer layer.   The catheter according to claim 10 or 11, wherein the reinforcing member is made of stainless steel.   The catheter according to any one of claims 1 to 12, wherein the catheter body has a lumen through which a guide wire can be inserted inside the inner layer.   The catheter according to any one of claims 1 to 13, wherein the catheter is a stenosis penetration catheter or a microcatheter.

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