JP2010119776A - Catheter support having modified cross section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in PTCA (Percutaneous Transluminal Coronary Angioplasty) or PTA (Percutaneous Transluminal Angioplasty), wherein a medical treatment catheter is bent in a guide catheter to lower axial pressing performance and torque transmitting performance. <P>SOLUTION: This catheter support, which is used in combination with the medical treatment catheter, includes a shaft part shaped to limit the radial movement of the medical treatment catheter extending over a fixed axial length in the interior of the guide catheter or a sheath introducer. This catheter support is thus used in combination with the medical treatment catheter, whereby the medical treatment catheter can be restrained from bending in the guide catheter to improve the axial pressing performance and torque transmitting performance of the medical treatment catheter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a catheter support used in combination with a therapeutic catheter used in medical applications, and more particularly, percutaneous angioplasty (PTA: Percutaneous) when performing peripheral angioplasty, coronary artery shaping, valvular shaping, and the like. The present invention relates to a catheter support used in combination with an intravascular catheter used in Transluminal Angioplasty (PTCA).

  2. Description of the Related Art Conventionally, percutaneous angioplasty is widely used for the purpose of expanding or treating a stenosis or occlusion in a blood vessel lumen and restoring or improving blood flow in a coronary artery or a peripheral blood vessel. As an example of a balloon catheter used in percutaneous angioplasty, a balloon catheter is formed by joining a balloon that can be inflated and deflated by adjusting internal pressure to the tip of a shaft. In general, a structure in which a lumen (guide wire lumen) through which a guide wire is inserted and a lumen (inflation lumen) for supplying a pressure fluid for adjusting balloon internal pressure are provided along the longitudinal direction of the shaft It is. Also, the balloon catheter has an over-the-wire type with a guide wire lumen over its entire length, and a rapid type in which the guide wire lumen extends only to the distal portion of the catheter to facilitate replacement of the balloon catheter. There is an exchange type.

  A general surgical example of PTCA using such a balloon catheter is as follows. First, a guide catheter (a sheath introducer such as a long sheath may be used in place of the guide catheter in PTA, but the sheath introducer is omitted in the following) is inserted into the puncture site of the femoral artery, brachial artery, radial artery, etc. The tip is placed at the entrance of the coronary artery through the aorta. Next, the guide wire inserted through the guide wire lumen is advanced beyond the stenotic site of the coronary artery, and a balloon catheter is inserted along the guide wire to match the balloon with the stenosis. Next, using a device such as an inflator, a pressure fluid is supplied to the balloon via an inflation lumen, and the balloon is inflated to expand the stenosis. After dilatation treatment of the stenosis, PTCA is terminated by retracting the balloon under reduced pressure and removing it from the body.

  In the above-described series of PTCA flows, in order to treat a stenotic site, it is necessary to push the catheter beyond the bend or stenosis of the blood vessel. In order to push the catheter forward, it is necessary to have a pressing property and a torque transmission property that efficiently transmit the force applied to the proximal portion to the distal end portion. Although various techniques devised in order to improve the pressability and torque transmission performance of the catheter have been disclosed, there are the following common problems.

  As shown in FIG. 1, when a treatment catheter such as a balloon catheter is pushed forward in the guide catheter, there is a certain amount of space between the guide catheter lumen and the shaft of the treatment catheter. Here, when the distal end portion of the treatment catheter passes through the bent portion or the narrowed portion, the distal end portion becomes difficult to advance, and thus a force is applied in the rearward direction in the axial direction by a reaction to the force applied to the proximal side. When force is applied in the axial rearward direction, as shown in FIG. 2, there is a space in the lumen of the guide catheter, in which the shaft of the treatment catheter is flexed and applied from the hand portion through the guide wire. Since the applied force is dispersed in the radial direction, it is difficult to transmit the force to the tip. In view of this, it is conceivable to employ a rigid shaft or a solution using a guide catheter having a small inner diameter so that the treatment catheter does not bend in the guide catheter. When a rigid shaft is used, the flexibility of the shaft is required at the bent or stenotic part of the blood vessel, so it is difficult to balance the rigidity and flexibility, and what is required varies depending on the lesion. It is difficult to optimize with a therapeutic catheter alone. In recent years, a kissing balloon technique in which two catheters are simultaneously inserted and treated has been frequently performed, and a guide catheter having a large inner diameter tends to be used to insert two catheters simultaneously.

  Further, even in a treatment catheter that requires torque transmission in order to pass through a bent portion or a narrowed portion, the torque transmission is significantly reduced by bending in the guide catheter.

  In patent document 1, it is an elongate catheter which consists of an inner tubular member, an outer tubular member, and an expansion balloon, Comprising: A 2nd lumen | bore is formed between an inner tubular member and an outer tubular member, and the said expansion balloon is a 2nd lumen | bore At least 30% of the inner circumferential surface of the outer tubular member and bonded to the outer surface of the inner tubular member. A catheter having an inner peripheral surface is disclosed.

  According to this prior art, by adhering the longitudinal portion of the outer tubular member to the outer surface of the inner tubular member, the outer diameter of the catheter body can be reduced at least in one direction in this region, and the diameter can be reduced. Is done. Furthermore, since the adhesion part of an inner tubular member and an outer tubular member mutually supports, the pressability of a catheter is improved. However, since the inner tubular member and the outer tubular member are bonded to each other at the bonded longitudinal portion, the flexibility is lowered, and the operability when the bonded longitudinal portion passes through the bent blood vessel is not good. In addition, when the treatment catheter is bent in the guide catheter, the pressing performance is remarkably lowered because the bending cannot be suppressed.

  In Patent Document 2, the catheter tube has a laminated structure including an inner layer tube and an outer layer tube, and the inner layer tube is formed of a soft material and a hard material alternately in the circumferential direction and is soft in the long axis direction. The material and the hard material are formed by extending in a band shape, and the cross-sectional area of the soft material portion is larger than the cross-sectional area of the hard material portion occupying the cross section of the inner tube at the distal end side of the tube, On the proximal end side of the tube, the cross-sectional area of the hard material portion is larger than the cross-sectional area of the soft material portion occupying the cross-section of the inner layer tube, and the outer tube is disclosed as a catheter tube made of the same material in the circumferential direction. Has been.

  According to this prior art, since there are many layers of hard material on the proximal end side of the tube, it is hard and has a relatively small flexibility, so that the operation force at the proximal end is easily transmitted to the distal end side. The pressability and torque transmission as a catheter are improved. However, as in Patent Document 1, when the treatment catheter bends in the guide catheter, the bend cannot be suppressed and the pressability is significantly reduced.

As described above, various techniques for improving the pressability and torque transmission performance of the catheter have been disclosed, but there is no viewpoint of suppressing the bending of the treatment catheter in the guide catheter, and the performance is not necessarily satisfactory. It was not a thing.
JP-A-5-137793 JP-A-9-38209

  Therefore, in view of the above problems, the present invention intends to solve the problem that the therapeutic catheter is prevented from being bent in the guide catheter used in combination in order to easily pass the bent portion or the narrowed portion. It is to improve the axial pressability and torque transmission of the treatment catheter.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

  That is, the present invention is a catheter support that is used together with a therapeutic catheter, and has a shaft that limits the radial movement of the therapeutic catheter over a certain length in the axial direction inside the guide catheter or sheath introducer. The present invention relates to a catheter support having a portion.

  The present invention also relates to a catheter support, wherein the shaft portion has a non-circular cross section.

  The present invention also relates to a catheter support characterized in that the shaft portion has a shape that restricts the radial movement of the treatment catheter from at least two directions.

  The present invention is also characterized in that the total radial space of the shaft portion is a space occupancy of 20% to 80% of the radial internal sectional space of the guide catheter or the sheath introducer. It relates to a support.

  The present invention is also characterized in that the entire radial cross-sectional space of the shaft portion is a space occupancy of 40% to 80% of the radial internal cross-sectional space of the guide catheter or the sheath introducer. It relates to a support.

  The present invention also relates to a catheter support having a point contact or line contact with a therapeutic catheter at least at two or more points.

  The present invention also relates to a catheter support characterized in that at least a part of the shaft portion has flexibility.

  The present invention also relates to a catheter support characterized in that it is more flexible than a treatment catheter in which at least a shaft portion is used in combination.

  The present invention also relates to a catheter support characterized in that at least a part of the shaft portion has rigidity.

  The present invention also relates to a catheter support characterized in that it has higher rigidity than a treatment catheter in which a shaft portion is used in combination.

  The present invention also relates to a catheter support characterized in that the shaft portion has an outer surface with low friction.

  The present invention also relates to a therapeutic catheter, characterized in that the catheter support is provided on at least a part of a catheter shaft.

  The present invention also relates to a balloon catheter comprising the catheter support body at least at a part of a catheter shaft.

  According to the catheter support according to the present invention, in order to fill the gap between the guide catheter lumen and the treatment catheter or to support the treatment catheter, the treatment catheter is prevented from being bent in the guide catheter, The pushability in the axial direction and the torque transmission performance of the treatment catheter can be improved. In addition, in the case of using a plurality of catheters, a treatment catheter or a balloon catheter including the catheter support in a part of the catheter shaft suppresses other treatment catheters from being bent in the guide catheter, and is used for treatment. The pushability in the axial direction of the catheter and the torque transmission can be improved.

  Hereinafter, various embodiments of a catheter support according to the present invention will be described in detail with reference to the drawings.

<Shaft section shape>
The catheter support according to the present invention has a shaft portion shaped so as to limit the radial movement of the treatment catheter used together in the guide catheter, so that the treatment catheter bends in the guide catheter. It can suppress and can improve the pressability to the axial direction of a catheter for treatment, and torque transmission nature.

  The cross-sectional shape of the shaft portion is not particularly limited as long as it is a shape that restricts the radial movement of the treatment catheter, but the cross-sectional shape in the radial direction is preferably noncircular. For example, when the radial cross section is circular as shown in FIG. 9, there are many gaps between the guide catheter lumen and the treatment catheter, and there is a space in which the treatment catheter moves in the radial direction as shown by an arrow. Since it cannot suppress that a catheter bends, it is not preferable.

  Preferably, the shape is such that the radial movement of the therapeutic catheter is restricted from at least two directions. The catheter support preferably has at least two or more point contact or line contact points with the treatment catheter. By having more contact parts, the catheter can be easily supported.

  For example, a crescent shape as shown in FIG. 3 is preferable, but any shape that surrounds the treatment catheter may be used, and a Y shape as shown in FIG. 5 and shapes as shown in FIGS. The shape of FIGS. 14 and 15 that fills the gap between the guide catheter and the treatment catheter can also provide the effects of the present invention. In addition, the outer surface of the catheter support may be rounded so as not to damage the inner surface of the guide catheter or the inner surface of the blood vessel.

  The production method of the shaft having a non-circular cross-sectional shape is not limited, but for example, it can be produced by general laser processing after extrusion molding with a circular cross-section, and extrusion molding using a deformed die or pressing by a mold It can also be manufactured by processing or the like.

<Shaft dimensions>
The dimension of the shaft portion of the catheter support can be freely designed according to the dimensions of the guide catheter and the treatment catheter used together.

The radial cross-sectional dimension is preferably such that the total cross-sectional space in the radial direction of the catheter support is 20% to 80% of the internal cross-sectional space in the radial direction of the guide catheter. Furthermore, it is more preferable that the total cross-sectional space in the radial direction of the catheter support is 40% to 80% of the internal cross-sectional space in the radial direction of the guide catheter. As shown in FIG. 10, the total cross-sectional space in the radial direction of the catheter support means the total cross-sectional area in the radial direction of the catheter support regardless of the presence or absence of the lumen of the catheter support. As shown in FIG. 11, the radial internal cross-sectional space of the guide catheter means the entire radial cross-sectional area of the guide catheter lumen. Taking a 6Fr sized guide catheter as a mainstream in PTCA in recent years, the lumen size of the 6Fr sized guide catheter is about 1.78 to 1.83 mm in diameter. The radial internal cross-sectional space of the 6Fr size guide catheter is 2.48 to 2.63 mm ² , and in this case, the total radial cross-sectional space of the catheter support is preferably 0.50 to 2.10 mm ² , More preferably, it is 0.99 to 2.10 mm ² . Furthermore, since the outer diameter of the treatment catheter used in a typical PTCA is 0.80 to 1.00 mm and the total radial sectional space is 0.50 to 0.79 mm ² , the catheter support The preferable range of the entire cross-sectional space in the radial direction of the body is 0.50 to 1.31 mm ² , more preferably 0.99 to 1.31 mm ² .

When the treatment catheter is a rapid exchange type, a guide wire is also present in the lumen of the guide catheter as shown in FIG. Since the outer diameter of the guide wire used in a typical PTCA is 0.35 to 0.45 mm, the total cross-sectional space in the radial direction of the guide wire is 0.10 to 0.16 mm ² . At this time, the preferable range of the entire cross-sectional space in the radial direction of the catheter support is 0.50 to 1.15 mm ² , more preferably 0.99 to 1.15 mm ² .

  Regarding the shaft length, for example, the length of a guide catheter used in a typical PTCA is 50 cm or 90 cm. Therefore, a non-circular cross-sectional portion is designed to have the same length as the guide catheter. preferable. The longer the non-circular cross-sectional portion is, the better. However, if there is a certain length, the effect of suppressing the bending of the treatment catheter can be obtained. In addition, the non-circular cross-sectional portion may be intermittent as long as the bending of the treatment catheter can be suppressed.

<Shaft material>
The flexibility and rigidity of the shaft portion of the catheter support according to the present invention can be freely designed according to the guide catheter and treatment catheter used together.

  In order for at least a part of the catheter support to be a flexible shaft, for example, the polymeric material may be polyethylene (very low density to very high density), polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer. Polymer, polyolefin such as cross-linked ethylene-vinyl acetate copolymer, polyester such as polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride, polystyrene, polyurethane, polyamide, polyimide, polyoxyethylene, polyvinyl alcohol, polytetrafluoroethylene, Various resins such as polyvinylidene fluoride and other fluororesins, thermoplastic elastomers such as polyamide elastomer and polyester elastomer, silicone rubber, latex rubber and the like can be suitably used.

  On the other hand, in order for at least a part of the catheter support to be a rigid shaft, a multi-layer structure, a braided tube or blade structure, or a core wire can be provided inside. In some cases, in order to increase the rigidity on the hand side, a flexible shaft with a high-rigidity resin material such as a metal such as superelastic alloy or stainless steel, polyimide, polyamideimide, or polyetheretherketone as the hand shaft. May be connected as a tip side shaft.

<Shaft outer surface>
Since the catheter support according to the present invention is inserted into the guide catheter at the same time as the treatment catheter, the outer surface of the catheter support has low friction for the purpose of easily inserting the treatment catheter and the catheter support. It is preferable. There is no limitation on the means for imparting low friction, but a hydrophilic coating may be applied to the outer surface of the catheter support or a low friction material may be used as the shaft outer layer on the shaft surface of the catheter support. It is also possible to reduce the surface area by sanding the outer surface of the shaft.

Although the kind of hydrophilic coating applied to the outer surface of the catheter support is not limited, for example, poly (2-hydroxyethyl methacrylate), polyacrylamide, polyvinylpyrrolidone, or the like can be suitably used. The longer the site where the hydrophilic coating is applied, the better. However, the application length can be determined according to the intended use of the catheter.
In addition, an antithrombotic substrate may be used as an outer layer or an antithrombogenic coating may be applied on the surface so that thrombus is not easily formed in the gap between the catheter support and the guide catheter or treatment catheter.

<Catheter>
The catheter support according to the present invention can be used for the purpose of supporting the therapeutic catheter used together, but the catheter support itself may be a catheter. Suitable for use as balloon catheters, penetration catheters for penetrating stenosis, suction catheters for sucking thrombus, contrast catheters for imaging blood vessels, injection catheters for injecting drugs, guide wire support catheters, etc. can do.

  As a typical embodiment, FIG. 6 is a schematic view of an embodiment in which the catheter support according to the present invention is applied to a rapid exchange type balloon catheter. A balloon is attached to the front end side of the front end side shaft, the rear end side shaft, and the front end side shaft. As shown in FIG. 7, the inner shaft is coaxially arranged on the distal side shaft, and a core material such as a core wire can be arranged so as to improve the rigidity balance and strength of the entire catheter. As shown in FIG. 8, the cross section of the rear end side shaft is crescent shaped so as to support the treatment catheter used together, and the inflation lumen for expanding the balloon penetrates in the axial direction, thereby providing rigidity balance and strength. A core wire for improvement can be arranged.

  When such a balloon catheter and a general treatment catheter are used in combination, they can support each other, so that the pressability and torque transmission can be improved, and the efficiency of treatment can be expected.

It is an axial sectional view of a guide catheter and a treatment catheter in general PTCA. It is an axial sectional view of a guide catheter in a general PTCA and a treatment catheter deflected therein. It is radial direction sectional drawing when the catheter support body and therapeutic catheter which concern on this invention are arrange | positioned in a guide catheter. It is an axial sectional view when a catheter support body and a treatment catheter according to the present invention are arranged in a guide catheter. It is radial direction sectional drawing when another embodiment of the catheter support body based on this invention and a treatment catheter are arrange | positioned in a guide catheter. It is the schematic of the rapid exchange type | mold balloon catheter as another embodiment of the catheter support body which concerns on this invention. It is sectional drawing in A-A 'of the balloon catheter shown in FIG. It is sectional drawing in B-B 'of the balloon catheter shown in FIG. FIG. 3 is a radial cross-sectional view of a catheter support and a treatment catheter having a circular radial cross section in a guide catheter. It represents the entire cross-sectional space in the radial direction of the catheter support. Internal cross-sectional space of guide catheter in the radial direction FIG. 6 is a radial cross-sectional view of another embodiment of a catheter support according to the present invention. FIG. 6 is a radial cross-sectional view of another embodiment of a catheter support according to the present invention. FIG. 6 is a radial cross-sectional view of another embodiment of a catheter support according to the present invention. FIG. 6 is a radial cross-sectional view of another embodiment of a catheter support according to the present invention. It is radial direction sectional drawing when the catheter support body and therapeutic rapid exchange type | mold catheter which concerns on this invention are arrange | positioned in a guide catheter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Treatment catheter 2 Guide catheter 3 Catheter support body 4 Balloon 5A Front end side shaft 5B Rear end side shaft 6D Inner shaft (guide wire lumen tube)
9B Inflation lumen 10 Core wire 11 Circular cross-section catheter support 12 Total cross-section space in the radial direction of the catheter support 13 Internal cross-section space in the radial direction of the guide catheter 14 Guide wire

Claims (13)

  A catheter support used in combination with a therapeutic catheter, and having a shaft portion configured to limit the radial movement of the therapeutic catheter over a certain length in the axial direction inside the guide catheter or the sheath introducer. A catheter support characterized.   The catheter support according to claim 1, wherein a cross section of the shaft portion is non-circular.   The catheter support according to claim 1 or 2, wherein the shaft portion has a shape that restricts the radial movement of the treatment catheter from at least two directions.   The total cross-sectional space in the radial direction of the shaft portion is a space occupancy of 20% to 80% of the internal cross-sectional space in the radial direction of the guide catheter or the sheath introducer. The catheter support according to any one of the above.   The total cross-sectional space in the radial direction of the shaft portion is a space occupancy of 40% to 80% of a radial internal cross-sectional space of the guide catheter or the sheath introducer. The catheter support according to any one of the above.   The catheter support according to any one of claims 1 to 6, wherein the catheter support has a portion that makes point contact or line contact with the therapeutic catheter at least at two or more points.   The catheter support according to any one of claims 1 to 6, wherein at least a part of the shaft portion has flexibility.   The catheter support according to claim 7, wherein the catheter support body is more flexible than a treatment catheter in which the shaft portion is used together.   The catheter support according to any one of claims 1 to 6, wherein at least a part of the shaft portion has rigidity.   The catheter support according to claim 9, wherein the catheter support body has a rigidity higher than that of the treatment catheter in which the shaft portion is used together.   The catheter support according to any one of claims 1 to 10, wherein the shaft portion has an outer surface having low friction.   A treatment catheter comprising the catheter support according to any one of claims 1 to 11 on at least a part of a catheter shaft.   A balloon catheter comprising the catheter support according to any one of claims 1 to 11 on at least a part of a catheter shaft.

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