JP7383625B2 - catheter - Google Patents

Description

The present invention relates to a catheter having a shaft portion that supports a guidewire.

As this type of catheter, a so-called over-the-wire type catheter is used, in which a lumen through which a guide wire is inserted is formed along the entire length of the catheter. In such a catheter, the guidewire and catheter can be placed coaxially over the entire length of the catheter, which improves the pushability of the guidewire when passing it through a stenosis or occlusion. Are better.

On the other hand, Japanese Unexamined Patent Publication No. 2004-275435 discloses a so-called rapid exchange type catheter that can shorten the length of a guide wire and facilitate catheter exchange. This catheter has a tubular distal shaft portion through which a guide wire is inserted, and a proximal shaft portion made of a solid wire connected to the proximal end of the distal shaft portion.

Further, US Patent Application Publication No. 2014/0358123 discloses a method for treating lower limb arteries by introducing the arterial fluid from the radial artery of the arm.

The catheter described in JP-A-2004-275435 mentioned above has a total length of up to 1700 mm, and the total length of the distal shaft portion is set to 100 mm to 400 mm, which is shorter than the total length of the proximal shaft portion. Therefore, there is a possibility that the catheter cannot be introduced from the arm blood vessel and the guide wire cannot efficiently reach the narrowed or occluded part of the lower limb blood vessel.

Furthermore, since the guide wire inserted into the distal shaft portion is exposed along the proximal shaft from the proximal end portion of the distal shaft portion, pushability is reduced. Therefore, even if the guide wire is pushed in from the hand, the exposed guide wire will bend, making it difficult to pass through the stenosis or occlusion.

The present invention has been made in consideration of such problems, and is a method for efficiently reaching a constricted or occluded portion of a lower extremity blood vessel by inserting a guide wire into the constricted or occluded portion of the lower extremity blood vessel through a blood vessel in the arm. The purpose is to provide a catheter that can

A first aspect of the present invention is a catheter including a flexible shaft supporting a guidewire and a hub provided at a proximal end of the shaft, the shaft having a flexible shaft through which the guidewire is inserted. a distal shaft portion having a lumen, and a proximal shaft portion extending from the proximal end of the distal shaft portion to the hub, the total length of the shaft is from 1500 mm to 2500 mm, and the distal shaft portion The catheter has a total length of 1350 mm or more, which is longer than the total length of the proximal shaft portion, and the proximal shaft portion is positioned radially outward from the outer peripheral surface of the distal shaft portion. .

A second aspect of the present invention is a catheter including a flexible shaft supporting a guidewire and a hub provided at a proximal end of the shaft, the shaft having a flexible shaft through which the guidewire is inserted. a distal shaft portion having a lumen, and a proximal shaft portion extending from the proximal end of the distal shaft portion to the hub; the total length of the shaft is from 1500 mm to 2500 mm; The catheter has a total length of 1350 mm or more , and the proximal shaft portion is positioned radially outward from the outer peripheral surface of the distal shaft portion .

According to the present invention, the guide wire is inserted through the lumen of the distal shaft portion, and since the distal shaft portion is longer than the proximal shaft portion, it can be inserted through the arm artery and lower limb blood vessels (e.g., iliac artery, femoral artery, etc.). The guide wire can efficiently reach stenosed or occluded parts of not only arteries but also popliteal arteries and more peripheral blood vessels.

FIG. 1 is a schematic diagram of a catheter according to an embodiment of the present invention. FIG. 3 is a partially omitted vertical cross-sectional view of the shaft. 2 is a flowchart illustrating a treatment method using the catheter of FIG. 1. FIG. 4A is a first explanatory view of the operation of the catheter of FIG. 1, and FIG. 4B is a second explanatory view of the operation of the catheter of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a catheter and a treatment method using the catheter according to the present invention will be described below with reference to the accompanying drawings.

The catheter 10 according to an embodiment of the present invention shown in FIG. , a medical device used to support the guidewire GW. Specifically, the catheter 10 is used, for example, to improve narrowed or occluded portions of blood vessels such as peripheral blood vessels of the lower limbs.

However, the present invention is not limited to catheter 10 used for percutaneous angioplasty. The present invention is also applicable to, for example, a catheter that supports the guide wire GW when the guide wire GW is passed through a stenosis or obstruction that occurs in a biological lumen such as a bile duct, esophagus, or urethra. In the following description of the catheter 10, the direction of arrow X1 (left side) in FIG. 1 will be referred to as the "distal end", and the direction of arrow X2 (right side) will be referred to as "proximal end".

The catheter 10 includes a flexible shaft 12 and a hub 14 provided at the proximal end of the shaft 12. As shown in FIGS. 1 and 2, the shaft 12 is long and has a small diameter. The total length L of the shaft 12 is not particularly limited, but is set to 600 mm to 2500 mm. In particular, when the catheter 10 is introduced from the radial artery to the lower limb artery to treat peripheral blood vessels of the lower limb, the total length L of the shaft 12 is preferably 1500 mm to 2500 mm.

The outer peripheral surface of the shaft 12 is preferably coated with a hydrophilic material (hydrophilic polymer). Examples of the hydrophilic material include, but are not limited to, a copolymer of methyl vinyl ether and maleic anhydride, a copolymer of dimethyl acrylamide and glycidyl methacrylate, and the like. Thereby, the shaft 12 can be smoothly and easily inserted into the living body lumen.

Shaft 12 has a tubular distal shaft section 16 and a solid proximal shaft section 18 extending from the proximal end of distal shaft section 16 to hub 14 . The total length L1 of the distal shaft portion 16 is longer than the total length L2 of the proximal shaft portion 18. Specifically, the total length L1 of the tip shaft portion 16 is 450 mm or more. In particular, when the catheter 10 is introduced from the radial artery to the lower limb artery to treat peripheral blood vessels of the lower limbs (when the total length L of the shaft 12 is 1500 mm or more), the total length L1 of the distal shaft portion 16 is set to 1350 mm or more. Set.

Examples of the constituent material of the tip shaft portion 16 include polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), Examples include polymeric materials such as vinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, mixtures thereof, or two or more of the above-mentioned polymeric materials.

A tapered surface 19 (see FIG. 2) whose diameter decreases toward the tip (in the direction of arrow X1) is formed on the outer peripheral surface of the tip of the tip shaft portion 16. A reinforcing body (not shown) may be embedded in the wall of the tip shaft portion 16. The reinforcing body is not particularly limited, but it is preferably made of tungsten, stainless steel, etc. and formed into a braided shape, a spiral coil shape, or a rod shape.

When the reinforcing body is wound in a braid, the diameter of the braid wire is preferably 0.04 mm or more and 0.12 mm or less, more preferably 0.06 mm or more and 0.10 mm or less. The pitch of the braided wires is preferably 0.4 mm or more and 0.8 mm or less. The distal shaft portion 16 may be provided with a contrast marker (not shown) made of a material that is opaque to X-rays (radiation).

In FIG. 2, the distal shaft portion 16 is a flexible tube having a lumen 20 through which the guide wire GW is inserted. The lumen 20 extends from the distal end of the distal shaft portion 16 to the proximal end with a constant diameter D1. That is, the distal shaft portion 16 is formed with a distal opening 22 through which the guide wire GW is inserted and a proximal opening 24 (insertion portion). The diameter D1 of the lumen 20 (inner diameter of the tip shaft portion 16) is not particularly limited, but is set to 0.4 mm or more and 1.1 mm or less. On the other hand, the outer diameter of the tip shaft portion 16 is 1.3 mm or more and 1.7 mm or less, and preferably 1.65 mm.

The proximal shaft portion 18 is a solid wire (rod-shaped portion). Examples of the constituent material of the proximal shaft portion 18 include metal materials such as stainless steel, Ni--Ti alloy, and cobalt-based alloy. Further, the proximal shaft portion 18 may be constructed by joining metal rods made of different materials to each other.

The proximal shaft portion 18 is provided eccentrically with respect to the distal shaft portion 16. The distal end of the proximal shaft portion 18 is connected to the proximal end of the distal shaft portion 16 by a connecting member 26 . The connecting member 26 is configured as a reinforcing tube. The connecting member 26 is firmly fused to the outer surface of the proximal end of the distal shaft portion 16 and the outer surface of the distal end of the proximal shaft portion 18 . The guide wire GW protrudes from the proximal opening 24 of the distal shaft portion 16 in the proximal direction.

The outer diameter D2 of the proximal shaft portion 18 is not particularly limited, but is preferably 0.5 mm to 1.5 mm, more preferably 0.9 mm to 1.1 mm. The outer diameter of the proximal shaft portion 18 may be constant or may vary along the axial direction of the proximal shaft portion 18.

The proximal shaft portion 18 may be provided coaxially with the proximal end portion of the distal shaft portion 16 . In this case, a side hole (insertion part) for leading out the guide wire GW from the lumen 20 to the outside of the distal shaft section 16 is formed at the base end of the distal shaft section 16 .

Further, a slit is formed in the proximal shaft portion 18, extending over the entire length L2 of the proximal shaft portion 18, and for guiding the guide wire GW from the proximal lumen to the outside of the proximal shaft portion 18. You can.

Further, the base end shaft portion 18 is not limited to a solid example, and may be a hollow pipe. The base end shaft portion 18 may be made of, for example, a metal material such as stainless steel or a Ni-Ti alloy, or a rigid resin material such as PEEK. When the catheter 10 is inserted from the junction of the aorta and the arm blood vessel, the rigid proximal shaft portion 18 does not cross the junction of the aorta and arm blood vessel, which has a small radius of curvature. Therefore, the proximal shaft portion 18 can be arranged without the risk of kinking or the like. On the other hand, the distal end shaft portion 16, which has improved kinkability due to reinforcement or the like, can reach the diseased part of the lower limb artery beyond the junction between the aorta and the arm blood vessel. It is preferable that the distal shaft portion 16, which is difficult to kink, is disposed at the junction between the aorta and the arm blood vessel, and the proximal end of the distal shaft portion 16 is located on the arm blood vessel side.

As shown in FIG. 1, the hub 14 is integrally formed in a hollow shape from a resin material. The hub 14 is formed in a size that is easy to hold by hand. The hub 14 has higher rigidity than the shaft 12.

The guide wire GW used together with such a catheter 10 is a linear member having appropriate rigidity and appropriate flexibility, and has an outer diameter slightly smaller than the diameter D1 of the lumen 20. Although the total length of the guide wire GW is longer than the total length of the catheter 10, it may be relatively short because it only needs to be inserted through a portion of the shaft 12 of the catheter 10.

The operation of passing the guide wire GW through a stenosis 100 that has occurred in a blood vessel 104 such as a peripheral blood vessel of a lower limb using the catheter 10 configured as described above will be described below.

First, in the guiding catheter placement step (step S1) of FIG. 3, the operator punctures a blood vessel (for example, radial artery) with a sheath introducer using the Seldinger method, and inserts the guide wire GW as shown in FIG. 4A. The guiding catheter 102 is first introduced and placed at a predetermined position within the blood vessel 105 (for example, a lower limb artery, for example, the superficial femoral artery (SFA)).

Furthermore, in the catheter preparation step (step S2) in FIG. 3, the operator prepares the catheter 10 described above. The operator then inserts the guide wire GW into the blood vessel 104 to a position before the stenosis 100.

Thereafter, in the insertion step (step S3), the operator inserts the catheter 10 into the inner lumen of the guiding catheter 102 with the guide wire GW inserted through the lumen 20 of the distal shaft portion 16.

Specifically, the operator passes the guide wire GW through the lumen 20 of the distal shaft section 16 from the distal opening 22 of the catheter 10 and guides it out of the distal shaft section 16 from the proximal opening 24 . As a result, the guide wire GW is inserted through the entire length of the lumen 20. In other words, the total length L1 of the distal shaft portion 16 (the monorail portion 36 in which the shaft 12 and the guide wire GW are disposed coaxially) absorbs the reaction force that acts on the guide wire GW when the guide wire GW passes through the stenosis 100. This is the supporting part that receives the support.

Subsequently, the operator advances the catheter 10 through the lumen of the guiding catheter 102, and positions its distal end slightly closer to the proximal end than the distal end of the guide wire GW. Then, in the guidewire passage step (step S4), the operator holds the proximal end of the guidewire GW and pushes it in the distal direction with the catheter 10 protruding from the distal end of the guiding catheter 102. The distal end of the guide wire GW is passed through the stenosis 100 (see FIG. 4B).

At this time, a reaction force from the stenosis part 100 acts on the guide wire GW, but the inner surface of the distal shaft part 16 (monorail part 36), which is longer than the proximal shaft part 18, contacts and supports the guide wire GW. Therefore, bending of the guide wire GW in a direction perpendicular to its axis can be suppressed. Thereby, the pushing force of the operator can be efficiently transmitted to the distal end of the guide wire GW. Therefore, the guide wire GW can be easily passed through the narrowed portion 100.

Next, in a removal step (step S5), the operator removes the catheter 10 from the body while leaving the guidewire GW indwelling beyond the stenosis 100. At this time, since the guide wire GW is inserted through only a portion of the shaft 12 (the entire length of the lumen 20), the catheter 10 can be easily removed from the guide wire GW.

Thereafter, various therapeutic catheters such as an atherectomy catheter, a balloon catheter, a stent delivery catheter, a drug-coated balloon catheter, a drug-coated stent delivery catheter, etc. are inserted along the guide wire GW to remove the calcified lesion in the stenosis 100. Dilation, drug application, stent placement, etc. are performed. Two or more therapeutic catheters may be used. After completing the treatment, the operator removes the treatment catheter and guiding catheter 102 from the body.

The guide wire GW and catheter 10 may have different hardness or thickness depending on the hardness of the stenosis or occlusion, the size of the guide wire lumen of the treatment catheter, the meandering of the blood vessel to the lesion, etc. Good too.

In this case, the catheter 10 according to this embodiment has the following effects.

According to this embodiment, the guide wire GW is inserted through the lumen 20 of the distal shaft portion 16, and the distal shaft portion 16 is longer than the proximal shaft portion 18. Further, the total length L1 of the tip shaft portion 16 is 450 mm or more. Therefore, the guide wire GW can be inserted from the arm artery to efficiently reach the stenotic or occluded part of the lower extremity blood vessels (for example, not only the iliac artery and femoral artery, but also the popliteal artery and more peripheral blood vessels). Can be done.

Since the guidewire GW inserted through the lumen 20 of the distal shaft portion 16 can be led out to the outside of the shaft 12 through the insertion portion (proximal opening 24), the guidewire GW can be inserted into the lumen 20 of the distal end shaft portion 16 and guided out to the outside of the shaft 12 through the insertion portion (proximal opening 24). The overall length of the GW can be shortened, and the catheter 10 can be easily replaced while the guidewire GW is left in the living body lumen.

Further, since the total length L1 of the distal shaft portion 16 is longer than the total length L2 of the proximal shaft portion 18, the guidewire GW is effectively supported by the distal shaft portion 16 when passing the guidewire GW through a stenosis or occlusion. can do.

Furthermore, since the total length L1 of the distal shaft portion 16 is 450 mm or more, the guide wire GW can be effectively supported by the distal shaft portion 16 when passing the guide wire GW through a stenosis or occlusion.

The total length L1 of the tip shaft portion 16 is 1350 mm or more. According to such a configuration, the guidewire GW can be more effectively supported by the distal end shaft portion 16 when passing the guidewire GW through the stenosis or occlusion.

The total length L of the shaft 12 is 1500 mm or more. According to such a configuration, when the distance from the introduction position of the catheter 10 into the living body lumen to the stenosis or occlusion part is relatively long (for example, when the catheter 10 is introduced from the radial artery and guided to the lower limb artery, Even when treating a stenosis or occlusion that has occurred in a terminal blood vessel of a lower limb), the distal shaft portion 16 allows the guidewire GW to be moved more effectively when passing the guidewire GW through the stenosis or occlusion. can be supported.

The catheter 10 supports a guide wire GW that is used when passing the guide wire GW through a stenosis or occlusion that occurs within a living body lumen. In this case, the guide wire GW can be effectively passed through the narrowed or occluded part within the living body lumen.

The treatment method using the catheter 10 includes a guiding catheter placement step in which the guiding catheter 102 is introduced from the arm artery and the distal end of the guiding catheter 102 is placed in the lower limb artery, and a catheter preparation step in which the catheter 10 is prepared. a step of inserting the catheter 10 into the inner lumen of the guiding catheter 102 with the guide wire GW inserted through the lumen 20 of the distal shaft portion 16; and a step of protruding the catheter 10 from the distal end of the guiding catheter 102. In this state, the catheter 10 includes a guidewire passing step of passing the guidewire GW through the stenosis or occlusion, and a removal step of removing the catheter 10 from the body while leaving the guidewire GW indwelling beyond the stenosis or occlusion.

According to such a method, it is possible to easily replace a catheter that is used to treat a narrowed or occluded part of a lower extremity blood vessel by inserting it from a blood vessel in the arm, and to pass the guide wire GW through the narrowed or occluded part. In this case, the guide wire GW can be effectively supported. In addition, since the guide wire GW is inserted through the lumen 20 of the distal shaft section 16 and the distal shaft section 16 is longer than the proximal shaft section 18, it is inserted through the arm artery and the lower extremity blood vessel (for example, the iliac artery, The guide wire GW can reach the stenotic or occluded part of not only the femoral artery but also the popliteal artery and more peripheral blood vessels.

The catheter 10 is not limited to the configuration described above. The total length L1 of the distal shaft portion 16 may be equal to or less than the total length L2 of the proximal shaft portion 18, as long as it is 450 mm or more.

It goes without saying that the catheter and treatment method using the catheter according to the present invention are not limited to the above-described embodiments, and can take various configurations without departing from the gist of the present invention.

Claims (4)

A catheter comprising a flexible shaft supporting a guidewire and a hub provided at a proximal end of the shaft,
The shaft is
a distal shaft portion having a lumen through which the guide wire is inserted;
a proximal shaft portion extending from the proximal end of the distal shaft portion to the hub;
The total length of the shaft is 1500 mm to 2500 mm,
The total length of the distal shaft portion is 1350 mm or more and longer than the total length of the proximal shaft portion,
The proximal shaft portion is located radially outward from the outer circumferential surface of the distal shaft portion . A catheter comprising a flexible shaft supporting a guidewire and a hub provided at a proximal end of the shaft,
The shaft is
a distal shaft portion having a lumen through which the guide wire is inserted;
a proximal shaft portion extending from the proximal end of the distal shaft portion to the hub;
The total length of the shaft is 1500 mm to 2500 mm,
The total length of the tip shaft portion is 1350 mm or more ,
The proximal shaft portion is located radially outward from the outer circumferential surface of the distal shaft portion . The catheter according to claim 1 or 2 ,
The catheter, wherein the proximal shaft portion is solid. The catheter according to any one of claims 1 to 3 ,
A catheter that supports the guidewire used when passing the guidewire through a stenosis or occlusion that occurs within a living body lumen.

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