JP2011110138A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter capable of balancing prescribed characteristics like forcing properties, rotatory power transmission properties, bending-resistant properties and the following properties to a guide wire on a high level and excellent in operability. <P>SOLUTION: The catheter includes a flexible tubular body constituted of a first region for forming a leading end region and a second region for forming a base end region and is characterized in that a coil, wherein a linear member which is wound in a circumferential direction, is provided in the wall of at least a part of the tubular body as a reinforcing layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a catheter.

In recent years, endovascular surgery for treating a lesion using a therapeutic treatment tool (device) such as a catheter percutaneously inserted into a blood vessel due to the merit of less invasiveness to a patient compared to conventional surgery. It has been actively performed.
In endovascular surgery, a device such as a catheter is inserted into a lesion through a narrow, meandering, branched thin blood vessel by pushing, pulling, or rotating the hand located outside the body. This is a technique for delivering a drug such as a contrast agent and an embolic agent, an embolic coil and the like to an affected area.

In general, when a catheter is inserted into a blood vessel, a flexible metal wire called a guide wire is first inserted up to the lesion, and the catheter is inserted into the lesion along the guide wire.
Therefore, the performance required for catheters is pushability called pushability, rotational force transmission that reliably transmits the rotational force at hand called torque, and bending resistance called kink resistance that does not cause bending. In addition, followability to the guidewire, that is, followability to the guidewire that smoothly follows the guidewire to the affected area even when the catheter is inserted along the guidewire, even within a highly flexible blood vessel Is required.

In order to improve pushability, it is known that the flexibility of the catheter should be increased from the proximal end portion toward the distal end portion.
In order to improve the rotational force transmission, a braided metal wire called a blade is inserted into the catheter wall as a reinforcing layer to increase the torsional rigidity, or the portion excluding the tip of the catheter is relatively It is known that it is good to be made of a hard material.
On the other hand, in order to improve the followability to the guide wire, it is known that the flexibility of the entire catheter is preferable.

As described above, in order to improve all the characteristics of "pushability", "rotational force transmission", and "followability to guide wire", it is necessary to obtain the contradictory performance of improving rigidity and flexibility. In order to achieve these characteristics in a well-balanced manner, by changing the hardness of the material, the density of the reinforcing layer, etc., the one with a graded or gentle change in hardness from the proximal end to the distal end of the catheter was developed. Is being used.
Patent Document 1 discloses a technique related to a catheter whose operability is improved by changing the hardness of a reinforcing layer of a braided wire and a resin layer constituting the catheter.
Patent Document 2 discloses a technique related to a catheter that is formed of a reinforcing layer in which a linear member is wound and has a hardness change in a stepwise manner.
Patent Document 3 discloses a technique related to a catheter with improved operability by conducting detailed studies on the diameter and thickness of a braided wire serving as a reinforcing layer.
Patent Document 4 discloses a technique related to a catheter which is formed of a coil reinforcement layer and has a hardness change by adjusting the coil winding pitch.
Patent Document 5 discloses a technique related to a catheter that is formed of a braided wire reinforcing layer and has a hardness changed by adjusting a braided angle of the braided wire.

JP 2007-89847 A JP 2005-334242 A JP 2007-82802 A JP 2001-218851 A Japanese Patent Laid-Open No. 06-1340342

As described above, the main characteristics that determine the operability of a catheter among the performances required for a catheter that uses a guide wire together are pushability, rotational force transmission, bending resistance, and followability to the guide wire.
However, since the structural factors that determine the respective characteristics are all related to the rigidity (flexibility) of the catheter, it is very difficult to simultaneously realize these characteristics in the most preferable state.

For example, it is necessary to increase the rigidity in order to increase the rotational force transmission, but this will reduce the followability to the guide wire.
On the other hand, in order to increase the followability to the guide wire, it is necessary to increase flexibility, but in that case, the rotational force transmission performance is sacrificed.
In other words, since it is difficult to resolve the physical contradiction for each of the above required characteristics, the reinforcement layer and the amount of change in hardness are adjusted in the conventional catheter as in the technique described in the above patent document. Thus, the required characteristics are balanced at a low level, and a catheter with high operability obtained by setting all the required characteristics to a high level cannot be realized.
In the present invention, the above-mentioned problems are solved, and the required characteristics such as pushability, rotational force transmission, bending resistance, and followability to the guide wire can be balanced to a high level, and the catheter has excellent operability. Is to provide.

Such an object is achieved by the present invention described in the following (1) to (8).
(1) A catheter having a flexible tubular body composed of a first region that forms a distal end side region and a second region that forms a proximal end side region,
A catheter comprising a coil in which a linear member is wound in a circumferential direction as a reinforcing layer in at least a part of the wall of the tubular body.
(2) The catheter according to (1), wherein a diameter in a cross section of the linear member constituting the coil is a substantially circular shape of 0.005 mm or more and 0.20 mm or less.
(3) In the cross section of the linear member constituting the coil, the linear member has a width substantially parallel to the circumferential direction of the tubular body and a thickness substantially parallel to the radial direction of the tubular body, The width | variety is 0.005 mm or more and 1.00 mm or less, and the thickness of the said linear member is 0.003 mm or more and 0.50 mm or less, The catheter as described in (1) or (2).
(4) The catheter according to any one of (1) to (3), wherein the reinforcing layer extends at least over the entire second region.
(5) The tubular body includes a plurality of hardness resin members, and is configured such that the hardness of the resin member decreases from the base end portion toward the tip end portion. The catheter described.
(6) In the second region, the bending rigidity (a) of a coil in which a plurality of linear members forming the reinforcing layer are wound in the circumferential direction, and the bending rigidity of a resin member forming the tubular body The catheter according to any one of (1) to (5), wherein the relationship (b) is (a) ≧ (b).
(7) In the first region, a bending rigidity (a) of a coil in which a plurality of linear members forming the reinforcing layer are wound in a circumferential direction, and a bending rigidity of a resin member forming the tubular body The catheter according to any one of (1) to (6), wherein the relationship (b) is (a) ≧ (b).
(8) The catheter according to any one of (1) to (7), wherein an outer diameter of the first region is 0.1 mm or more and 1.0 mm or less.

  According to the catheter of the present invention, required characteristics such as pushability, rotational force transmission, bending resistance, and followability to the guide wire can be balanced to a high level, and a catheter excellent in operability can be obtained. it can.

It is a whole schematic diagram showing an example of the catheter of the present invention. It is a longitudinal cross-sectional schematic diagram of a tubular body (1st area | region and 2nd area | region). It is a circumferential direction cross-sectional schematic diagram of a reinforcement layer, Comprising: An example of a linear member shape is shown. It is a circumferential direction cross-sectional schematic diagram of a reinforcement layer, Comprising: Another example of a linear member shape is shown.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.
FIG. 1 is an overall schematic view showing an example of the catheter of the present invention. The catheter of this embodiment is a first region 2 forming a distal end side region on the left side of the drawing, and a proximal end portion on the right side of the drawing. It has the flexible tubular body 1 comprised from the 2nd area | region 3 which forms a side area | region.

FIG. 2 is a schematic longitudinal sectional view of the tubular body 1 (first region 2 and second region 3) of the catheter of the present invention. In the catheter of this embodiment, the resin member 4 and the linear member 5 are circumferential. And a reinforcing layer having a coil 5 wound around.

The catheter of the present invention is characterized in that a coil 6 in which a linear member 5 is wound in the circumferential direction is provided as a reinforcing layer in at least a part of the wall of the tubular body 1. This reinforcing layer will be described in detail.
The reinforcement layer should just be formed in at least one part of the 1st area | region 2 and / or the 2nd area | region 3, and may be formed over the full length as needed.
The range is not particularly limited, and can be selected depending on the intended use of the catheter.

It is preferable that the reinforcing layer extends at least over the entire second region 3. By doing so, it is possible to improve the rotational force transmission and pushability of the entire catheter.
In addition to the characteristics of the resin member constituting the tubular body 1, the linear member that forms the coil 6 has the pushability, rotational force transmission, and bending resistance of the tubular body 1 in the region where the reinforcing layer is provided in the wall. It can be adjusted by the number of 5, the cross-sectional diameter, and the winding angle.
Compared to the resin member 4, the coil 6 has a characteristic that it has less influence on rigidity (flexibility) when adjusting the pushability, rotational force transmission property, and bending resistance.
Therefore, in the catheter of the present invention, by adjusting the characteristics of the tubular body 1 by combining the characteristics of the resin member 4 and the coil 6, the pushability, the rotational force transmission, the bending resistance, and the guide wire are adjusted. All required characteristics including followability can be balanced at a high level.

The number of the linear members 5 is not particularly limited, and one or a plurality of the linear members 5 can be appropriately selected and used.
Although the pushability, rotational force transmission, bending resistance and followability to the guide wire can be improved in proportion to the number of the linear members 5 to be used, the thickness and winding of the linear members 5 described later can be improved. Since the number of wires that can be used is limited by the angle and winding interval (winding pitch), the number of wires that can be used under each condition is determined after determining the thickness, winding angle, and winding pitch of the linear member 5. May be selected according to the desired required characteristics.

The cross-sectional shape of the linear member 5 forming the coil 6 is not particularly limited, but is preferably substantially circular as shown in FIG. However, in addition to this substantially circular shape, a substantially rectangular shape, a substantially half-moon shape lacking a part of the inside or outside of the substantially circular shape, etc. can also be used.
When the linear member 5 having a substantially circular cross section is used, the diameter in the cross section is preferably 0.005 mm or more and 0.20 mm or less. By doing so, it is possible to improve pushability, rotational force transmission, and bending resistance. Furthermore, if it is 0.01 mm or more and 0.10 mm or less, it is particularly preferable because good pushability, rotational force transmission, bending resistance, and followability to the guide wire can be obtained in a preferable dimension as the catheter of the present invention described later. .

  As shown in FIG. 4, when using a linear member 5 having a substantially rectangular cross section, the width approximately parallel to the circumferential direction of the tubular body 1 is 0.005 mm or more and 1.00 mm or less, And, if the thickness substantially parallel to the radial direction of the tubular body 1 is 0.003 mm or more and 0.50 mm or less, it is excellent in pushability, rotational force transmission, bending resistance and followability to the guide wire, The width approximately parallel to the circumferential direction of the tubular body 1 is 0.01 mm or more and 0.5 mm or less, and the thickness substantially parallel to the radial direction of the tubular body 1 is 0.005 mm or more and 0.1 mm or less. It is preferable that This is particularly preferable because favorable pushability, rotational force transmission, bending resistance, and followability to the guide wire can be obtained in preferable dimensions as the catheter of the present invention described later.

The material of the linear member 5 forming the coil 6 is not particularly limited, and a metal wire such as stainless steel (SUS), piano wire, nickel titanium alloy, etc. can be used, and rolling, quenching, etc., as necessary. What changed the toughness by the process of can also be used.
In addition to metal wires, fine fibers of polymer fibers such as PI, PAI, PA, and PET may be used.

The characteristics of the reinforcing layer can be adjusted by the winding angle in addition to the number of the linear members 5 and the cross-sectional area.
The winding angle can be selected in the range of 0 degrees to 90 degrees with respect to the circumferential cutting plane, but is 0 degree which is horizontal to the circumferential cutting plane and perpendicular to the circumferential cutting plane. At 90 degrees, the coil does not substantially become a coil, so in practice, it is selected within the range where the coil can be formed.
The smaller the aforementioned winding angle, that is, closer to 0 degree, the lower the pushability and rotational force transmission of the reinforcing layer.
Conversely, the greater the above-described winding angle, that is, closer to 90 degrees, the better the pushability and rotational force transmission of the reinforcing layer.
On the other hand, the torsional resistance at the time of bending increases from 0 degrees to 90 degrees, and a larger rotational force is required when rotating the curved catheter.
Note that the winding interval (winding pitch) of the linear member 5 described above is defined by the thickness, number, and winding angle of the linear member 5 to be used.

The resin member 4 will be described.
The resin member 4 is not particularly limited. For example, in addition to PI, PAI, PET, polyethylene (PE), polyamide (PA), nylon elastomer, polyurethane (PU), ethylene-vinyl acetate resin (EVA), polychlorinated Vinyl (PVC) or polypropylene (PP) can be used.
Further, the resin member 4 may be made of a single material, and different types of resin materials having different physical or chemical properties are arranged in the circumferential direction from the inside to the outside of the tubular body 1. You may be comprised by laminating | stacking.

Moreover, for example, a fluorine-based resin such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), or perfluoroalkoxy fluororesin (PFA) can be used for the inner layer surface of the resin member 4.
By using a fluorine-based resin on the inner layer surface of the resin member 4, the slidability of the guide wire passing through the catheter is improved, and further, the deterioration resistance against chemicals when a contrast medium or a chemical solution is supplied to the affected part through the catheter, Good delivery.

  Furthermore, in order to improve the lubricity with the blood vessel wall, a hydrophilic resin material such as polyvinyl pyrrolidone or a maleic anhydride copolymer may be used on the outer layer surface.

Further, the catheter of the present invention is preferably configured such that the hardness of the resin member 4 decreases stepwise or continuously from the proximal end portion toward the distal end portion. By doing so, it is excellent in pushability and rotational force transmission.
Further, the resin member 4 forming the tubular body 1 is made of a resin material having a plurality of hardnesses, and the resin member 4 can be configured such that the hardness of the resin member 4 decreases from the proximal end portion toward the distal end portion. By doing so, it is preferable because, when combined with the reinforcing layer, a change in physical properties in which the hardness decreases stepwise or continuously from the proximal end portion to the distal end portion of the tubular body 1 can be set more precisely. .

  In the second region 3 of the tubular body 1, the bending rigidity (a) of the coil 6 in which a plurality of linear members 5 forming the reinforcing layer are wound in the circumferential direction and the tubular body 1 are formed. Adjust the material, winding angle and number of coils 6 used, and the material and thickness of the tubular body 1 so that the relationship of the bending rigidity (b ′) of the resin member 4 satisfies (a) ≧ (b). Therefore, it is preferable because the excellent characteristics of the coil 6 with respect to the rotational force transmission, the rotational resistance at the time of bending, and the maintenance of flexibility are exhibited.

  Further, in the first region 2 of the tubular body 1, the bending rigidity (a) of the coil 6 in which a plurality of linear members 5 forming the reinforcing layer are wound in the circumferential direction, and the tubular body 1 are The material, winding angle and number of coils 6 used, and the material and thickness of the tubular body 1 are adjusted so that the relationship of the bending rigidity (b) of the resin member 4 to be formed satisfies (a) ≧ (b). This is preferable because the excellent characteristics of the coil 6 with respect to the rotational force transmission, the rotational resistance at the time of bending, and the maintenance of flexibility are exhibited.

  In the catheter of the present invention, when the outer diameter in the first region 2 is 0.1 mm or more and 1.0 mm or less, it can be used particularly suitably as a microcatheter.

DESCRIPTION OF SYMBOLS 1 Tubular body 2 1st area | region 3 2nd area | region 4 Resin member 5 Linear member 6 Coil

Claims (8)

A catheter having a flexible tubular body composed of a first region forming a distal end side region and a second region forming a proximal end side region,
A catheter comprising a coil in which a linear member is wound in a circumferential direction as a reinforcing layer in at least a part of the wall of the tubular body.   The catheter according to claim 1, wherein a diameter of a linear member constituting the coil in a cross section is a substantially circular shape having a diameter of 0.005 mm or more and 0.20 mm or less.   The cross-section of the linear member constituting the coil has a width substantially parallel to the circumferential direction of the tubular body and a thickness substantially parallel to the radial direction of the tubular body, and the width of the linear member is The catheter according to claim 1 or 2, wherein the thickness is 0.005 mm or more and 1.00 mm or less, and the thickness of the linear member is 0.003 mm or more and 0.50 mm or less.   The catheter according to any one of claims 1 to 3, wherein the reinforcing layer extends at least over the entire second region.   The catheter according to any one of claims 1 to 4, wherein the tubular body is made of a resin member having a plurality of hardnesses, and the hardness of the resin member decreases from a proximal end portion toward a distal end portion. In the second region, the bending rigidity (a) of a coil in which a plurality of linear members forming the reinforcing layer are wound in the circumferential direction, and the bending rigidity (b) of a resin member forming the tubular body Relationship
(A) ≧ (b)
The catheter according to any one of claims 1 to 5. In the first region, the bending rigidity (a) of a coil in which a plurality of linear members forming the reinforcing layer are wound in the circumferential direction, and the bending rigidity (b) of a resin member forming the tubular body Relationship
(A) ≧ (b)
The catheter according to any one of claims 1 to 6.   The catheter according to any one of claims 1 to 7, wherein an outer diameter of the first region is 0.1 mm or more and 1.0 mm or less.

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