Catheter

Abstract

To provide a catheter capable of reducing movement of a standing position of an operator and reducing work near an X-ray tube.SOLUTION: A second catheter 14 includes a catheter body 18 having a distal end portion 22 and a proximal end portion 24, a hub 20 connected to the proximal end portion 24 of the catheter body 18, and a bending portion 26 located between the distal end portion 22 and the proximal end portion 24 of the catheter body 18, which is shaped such that the catheter body 18 is bent in a U-shape. The length L2 from the bending portion 26 to the proximal end portion 24 is longer than the length L1 from the bending portion 26 to the distal end portion 22, A distal body portion 32 from the bending portion 26 to the distal end portion 22 is inserted into a lower limb artery in a retrograde manner in a state in which the bending portion 26 is disposed outside the body to treat an occluded site C of the lower limb artery.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a catheter that is percutaneously inserted into a blood vessel to treat a lesion within the blood vessel. [Background technology]

[0002] Intravascular treatment using a catheter is performed to treat lesions such as stenosis or chronic total occlusion (CTO) in the arterial blood vessels of the lower limbs. In this treatment, the catheter is introduced, for example, from the radial artery in the wrist or the femoral artery in the leg, and advanced in an antegrade direction from the heart toward the arterial blood vessels of the lower limbs. Once the catheter reaches the occlusion site, a guidewire is used to open the occlusion site. If the occlusion site is successfully opened, the catheter is advanced along the guidewire, and a treatment device such as a balloon or stent is placed at the lesion site, thereby performing treatment to penetrate the occlusion site.

[0003] Furthermore, if antegrade canalization is difficult, an additional procedure may be performed in which a catheter is introduced from a peripheral site of the lower limb artery at the ankle and the blocked area is canalized in a retrograde direction.

[0004] Patent Document 1 discloses a technique for introducing a catheter in a retrograde direction to treat an obstructed area, while Non-Patent Document 1 reports the success rates of procedures attempting to open an obstructed area in an antegrade direction and in a retrograde direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 10,159,822 [Non-patent literature]

[0006] [Non-Patent Document 1] Journal of Endovascular Therapy 2022, Vol. 29(2) 215-225 Summary of the Invention [Problem to be solved by the invention]

[0007] When inserting a catheter into a lower limb artery in the antegrade direction from the wrist and in the retrograde direction from the ankle, the insertion sites of the two catheters into the blood vessels are far apart. Therefore, in conventional procedures, the surgeon must frequently move his / her position to operate the two catheters and guidewire, which complicates the procedure or requires two surgeons. In addition, while an X-ray fluoroscopy system is used to visualize the occlusion site, conventional procedures increase the surgeon's exposure to radiation due to the increased frequency of work near the X-ray tube.

[0008] An object of the present invention is to solve the above-mentioned problems. [Means for solving the problem]

[0009] (1) A first aspect of the disclosure below is a catheter comprising: a catheter body having a distal end and a proximal end; a hub connected to the proximal end of the catheter body; and a bending portion located between the distal end and the proximal end of the catheter body and shaped so that the catheter body is bent with a curvature and the distal end approaches the proximal end, wherein the distal end side of the catheter body is inserted retrogradely into a lower limb artery with the bending portion positioned outside the body to treat a diseased portion of the lower limb artery.

[0010] The catheter of item (1) above has a bending section that bends outside the body, so that when the distal end of the catheter body is inserted into the arterial blood vessel of the lower limb, the hub of the catheter introduced in the retrograde direction can be positioned near the hub of the catheter introduced in the antegrade direction. Therefore, the catheter described above can reduce the operator's need to move their position and the need to work near the X-ray tube.

[0011] (2) In the catheter described in item (1) above, the length of the proximal body portion constituting the portion of the catheter body from the apex of the bent portion to the proximal end may be longer than the length of the distal body portion constituting the portion of the catheter body from the apex of the bent portion to the distal end. The catheter described in item (2) above allows the hubs of the two catheters to be placed side by side at the surgeon's fingertips. That is, the hub of the catheter described in item (2) that is introduced in the retrograde direction can be placed near the hub of the catheter that is introduced in the antegrade direction, thereby reducing the surgeon's need to move their standing position and the need to work near the X-ray tube.

[0012] (3) In the catheter according to the above item (1) or (2), the length of the distal main body may be 30 to 60 cm. The catheter according to item (3) can reach the lesion (blockage site) by being inserted into the arterial blood vessel of the lower limb from the ankle.

[0013] (4) In the catheter according to any one of the above items (1) to (3), the length of the catheter body may be 70 to 100 cm. The catheter according to item (4) allows the hub to be positioned near the hub of the catheter introduced from the antegrade direction, thereby reducing the need for the operator to move their standing position and the need to perform work near the X-ray tube.

[0014] (5) In the catheter according to any one of the above items (1) to (4), the distal end portion may have a curved tip portion.

[0015] (6) A second aspect of the disclosure below is a treatment method comprising: a first step of introducing a first catheter from a radial artery and reaching a lesion in a lower limb artery in the antegrade direction of the lower limb artery; and a second step of inserting a second catheter into the lower limb artery at the ankle and reaching the second catheter in the retrograde direction of the lower limb artery to the lesion in the lower limb artery, wherein the second catheter comprises a catheter body having a distal end and a proximal end, a hub connected to the proximal end of the catheter body, and a bending portion located between the distal end and the proximal end of the catheter body and shaped to bend the catheter body with a curvature so that the distal end approaches the proximal end; and wherein in the second step, the bending portion is positioned outside the body, and the hub of the second catheter is positioned closer to the hub of the first catheter than the lesion.

[0016] The treatment method of the above item (6) can insert the catheter into the lesion from both the antegrade and retrograde directions while restricting the operator from moving his / her position or working near the X-ray tube.

[0017] (7) In the treatment method according to the above item (6), the second step may be performed after the first step. The treatment method according to item (7) improves the efficiency of treatment because the first catheter is introduced first from the antegrade direction, which allows for the introduction of a thick catheter.

[0018] (8) In the treatment method described in the above item (6) or (7), the length of the proximal body portion constituting the portion of the catheter body from the apex of the bent portion to the proximal end may be longer than the length of the distal body portion constituting the portion of the catheter body from the apex of the bent portion to the distal end. The treatment method described in item (8) allows the hub of the second catheter to be positioned near the hub of the first catheter, thereby reducing the need for the operator to move their standing position or perform work near the X-ray tube. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is an explanatory diagram showing an outline of a method for treating arterial blood vessels in the lower limbs using a first catheter and a second catheter according to the first embodiment. [Figure 2] FIG. 2 is a plan view of the second catheter and guidewire of FIG. [Figure 3] FIG. 3 is an explanatory diagram showing an example of a method for introducing the second catheter into a blood vessel. [Figure 4] FIG. 4 is an explanatory diagram showing a method for treating a lesion using a first catheter and a second catheter. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1, a treatment system 10 according to this embodiment is used to treat lesions such as stenosis in the arteries of the lower limbs and chronic total occlusion (CTO), which is a long-term stenosis of the arteries of the lower limbs. As shown in the figure, the treatment system 10 includes a first catheter 12, a second catheter 14, and an X-ray fluoroscope 16.

[0021] The first catheter 12 is a catheter that is inserted into an artery from the radial artery in the wrist or the femoral artery in the leg, and introduced in the antegrade direction toward an occlusion site C (lesion site) in a lower limb artery. The antegrade direction is the direction along the blood flow in the blood vessel, and in the case of an artery, it is the direction of progression from the heart side toward the occlusion site C. While FIG. 1 illustrates an example in which the first catheter 12 is introduced from the radial artery in the wrist, this embodiment is not limited to this. The first catheter 12 has a lumen therein that accommodates a guidewire 40, a treatment balloon catheter, or the like, so that the guidewire 40 can be inserted therethrough. The guidewire 40 is used to open the occlusion site C.

[0022] The second catheter 14 is a catheter that is introduced in a retrograde direction when it is difficult to open the occluded site C using the first catheter 12. The retrograde direction is the direction in which blood flows against the blood flow in the blood vessel, and is the opposite direction to the antegrade direction. The second catheter 14 is inserted into the lower limb arterial blood vessel A (see Figure 4) from the peripheral side of the lower limb artery near the ankle, and approaches the occluded site C in a retrograde direction. Details of the second catheter 14 will be described later.

[0023] The X-ray fluoroscope 16 irradiates the illustrated X-ray irradiation area with X-rays to visualize the occlusion site C and the first catheter 12 and the second catheter 14 in the vicinity thereof. The canalization of the occlusion site C is performed under imaging by the X-ray fluoroscope 16.

[0024] The second catheter 14 will be described in further detail below.

[0025] As shown in FIG. 2, the second catheter 14 has a catheter body 18 and a hub 20. The catheter body 18 is a long, tubular member having moderate flexibility. The catheter body 18 has a distal end portion 22, a proximal end portion 24, a bending portion 26, and an inner lumen 28. The distal end portion 22 is the end of the catheter body 18 that is located away from the hub 20. The catheter body 18 has a tip shape portion 30 at the distal end portion 22. The tip shape portion 30 is composed of a cylindrical member shaped, for example, in a V-shape.

[0026] The proximal end 24 is the end of the catheter body 18 that is connected to the hub 20. The catheter body 18 is supported at the proximal end 24 by the hub 20.

[0027] The curved portion 26 is located within the catheter body 18, between the distal end 22 and the proximal end 24. The curved portion 26 is a portion of the catheter body 18 that is bent with a gentle curvature. The radius of curvature of the curved portion 26 can be appropriately selected so as not to interfere with the insertion of the guidewire 38. In the example shown in FIG. 2, the curved portion 26 is shaped like a U. The curved portion 26 is not limited to a U-shape and may be C-shaped. The curved portion 26 may be configured by combining a curved portion and a straight portion.

[0028] The catheter body 18 is shaped so that the portion of the bent portion 26 that is located farthest from the hub 20 is the apex 26a, and the bent portion 26 bends the distal end 22 closer to the hub 20 than the apex 26a of the bent portion 26. When the hub 20 is held in the hand, the bent portion 26 of the catheter body 18 is located farthest from the hub 20. The catheter body 18 has a distal body section 32 and a proximal body section 34. The distal body section 32 constitutes the portion of the catheter body 18 from the apex 26a of the bent portion 26 to the distal end 22. The proximal body section 34 constitutes the portion of the catheter body 18 from the apex 26a of the bent portion 26 to the proximal end 24.

[0029] The distal main body portion 32 extends in a direction approaching the proximal end portion 24 via the bending portion 26. The distal main body portion 32 is introduced into a distal artery of the lower limb from near the ankle. The distal main body portion 32 has a length L1. The length L1 of the distal main body portion 32 is the length of the portion of the catheter body 18 from the bending portion 26 to the distal end portion 22 in the axial direction of the hub 20. The length L1 is set to a dimension that enables the distal main body portion 32 to reach the occlusion site C from the puncture site in the ankle when the distal main body portion 32 is inserted into an artery of the lower limb with the bending portion 26 positioned outside the body. In one aspect, the length L1 of the distal main body portion 32 can be, for example, 30 cm to 60 cm, and is 30 cm in this embodiment.

[0030] The proximal body portion 34 is integrally connected to the distal body portion 32. The proximal body portion 34 enables the hub 20 to be positioned closer to the hub 42 of the first catheter 12 when the distal body portion 32 is introduced into the lower limb arterial blood vessel A. The length L2 of the proximal body portion 34 is the length of the portion of the catheter body 18 from the bent portion 26 to the proximal end portion 24 in the axial direction of the hub 20. The length L2 of the proximal body portion 34 is longer than the length L1 of the distal body portion 32.

[0031] The second catheter 14 having such a proximal main body portion 34 can have its hub 20 positioned close to the hub 42 of the first catheter 12, thereby reducing the need for the surgeon M to change his or her standing position and to perform tasks near the X-ray fluoroscope 16. The length L2 of the proximal main body portion 34 can be, for example, 30 to 120 cm, more preferably 40 to 110 cm, and is 40 cm in this embodiment.

[0032] The shape of the proximal main body 34 is not limited to being linear, and may be curved as a whole. The total length of the catheter body 18 may be the sum of the length L1 of the distal main body 32 and the length L2 of the proximal main body 34, or may be the length from the distal end 22 to the proximal end 24, but the total length of the catheter body 18 is particularly preferably 70 to 100 cm, and is 70 cm in this embodiment.

[0033] The catheter body 18 has an internal lumen 28 that extends along the centerline of the catheter body 18. The lumen 28 opens at the distal end 22 and communicates with a cavity 36 in the hub 20 at the proximal end 24. The lumen 28 has an inner diameter that allows a guidewire 38 to pass through.

[0034] The hub 20 is connected to the proximal end 24 of the catheter body 18. The hub 20 has an outer diameter that allows it to be easily gripped by the hand of the surgeon M. The hub 20 transmits the operating force of the surgeon M to the catheter body 18. The hub 20 has an interior cavity 36 that communicates with the lumen 28 of the catheter body 18. The hub 20 allows a guide wire 38 to be inserted into the lumen 28 of the catheter body 18 through the cavity 36.

[0035] Guidewire 38 is manipulated through a guidewire hub located near hub 20 of second catheter 14. The tip of guidewire 38 protrudes from distal end 22 and is inserted into the occlusion site C in a retrograde direction.

[0036] The treatment system 10 of this embodiment is configured as described above. A method for treating an occluded site C of a lower limb arterial blood vessel A using the treatment system 10 will now be described.

[0037] As shown in Figure 1, the first step is to insert a first catheter 12 into a blood vessel. In the illustrated example, the first catheter 12 is inserted into the blood vessel from the radial artery in the right wrist. The first catheter 12 is advanced from the radial artery, brachiocephalic artery, and aorta to the iliac artery, femoral artery, and popliteal artery of either the left or right leg, and into the lower limb artery A of either the left or right leg.

[0038] In this case, the first catheter 12 is advanced in the antegrade direction toward the occlusion site C of the tibial artery. The first catheter 12 is guided to the predetermined occlusion site C by sliding along the preceding guide wire 40. Because the first catheter 12 is introduced through a large artery on the heart side, a catheter with a relatively large diameter can be used. Therefore, the first catheter 12 may be capable of inserting a treatment catheter such as a balloon or stent near its tip. The first catheter 12 may also be introduced from the left wrist and reach the lower limb artery of either the left or right leg.

[0039] Thereafter, the guidewire 40 is advanced from the first catheter 12 toward the occluded area C, and an attempt is made to open the occluded area C. The occluded area C may be more firmly blocked on the side of the heart where the pressure is higher, making it difficult to open the guidewire 40 in the antegrade direction. In this case, the treatment method proceeds to the second step of inserting the second catheter 14.

[0040] As shown in FIG. 3, the second step includes inserting the second catheter 14 into a distal artery of the lower limb near the ankle. In this case, for example, the second step may include inserting the second catheter 14 into the tibial artery. As shown in the figure, the second catheter 14 can be grasped by bundling the distal main body portion 32 and the proximal main body portion 34. Furthermore, by grasping the bending portion 26 in the palm of the hand, the operating force can be easily transmitted in the direction of advancing the distal main body portion 32. Therefore, the bending portion 26 facilitates the operation of pushing the distal main body portion 32. Through the above operations, the distal end portion 22 of the second catheter 14 is positioned near the occlusion site C of the arterial blood vessel A of the lower limb, as shown in FIG. 4.

[0041] 1, when the distal end 22 of the second catheter 14 is positioned near the occlusion site C, the hub 20 of the second catheter 14 is positioned closer to the hub 42 of the first catheter 12 than the occlusion site C. This allows the surgeon M, who is standing near the patient's wrist, to operate the second catheter 14 from that location.

[0042] Next, an operation is performed to protrude the guidewire 38 from the distal end 22 of the second catheter 14 through a guidewire hub disposed at the proximal end of the hub 20 of the second catheter 14. The guidewire 38 of the second catheter 14 advances in the retrograde direction toward the occluded site C, thereby opening the occluded site C. In this way, the treatment method of this embodiment opens the occluded site C in both the antegrade and retrograde directions, thereby more effectively opening the occluded site C in the arterial blood vessels A of the lower limb.

[0043] Because the hub 20 of the second catheter 14 is located near the hub 42 of the first catheter 12, the surgeon M does not need to change his / her position when manipulating the guide wire 38, allowing for a smooth procedure. In addition, because there is no need to pass near the X-ray fluoroscope 16 to operate the guide wire 38 of the second catheter 14, the amount of radiation exposure to the surgeon M can be reduced.

[0044] Once the guidewire 40 has passed through the occluded area C, the first catheter 12 is advanced, sliding along the guidewire 40, and the first catheter 12 is placed at the occluded area C. Thereafter, treatment is performed using a treatment device (deployment of a stent or balloon) or by administering a therapeutic drug through the first catheter 12. The treatment method of this embodiment is completed by the above operations.

[0045] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the spirit of the present invention. For example, the second catheter 14 may be inserted first, or the second catheter 14 may be inserted into a blood vessel more peripheral or closer to the heart. [Explanation of symbols]

[0046] 10...treatment system 12...first catheter 14... Second catheter 16... X-ray fluoroscopy device 18...Catheter body 20, 42...Hub 22...Distal end 24...Proximal end 26...Bending part 28...Inner cavity 30...Tip shape portion 32...Distal main body portion 34...proximal body portion 36...cavity portion 38, 40...Guidewire C...Occlusion site

Claims

1. a catheter body having a distal end and a proximal end; a hub connected to the proximal end of the catheter body; a bending portion located between the distal end and the proximal end of the catheter body, the bending portion being shaped so that the catheter body bends with a curvature and the distal end approaches the proximal end, The distal end of the catheter body is inserted retrograde into a lower limb artery with the bending portion positioned outside the body to treat a lesion in the lower limb artery.

2. 2. The catheter according to claim 1, wherein the length of a proximal body section constituting the portion of the catheter body from the apex of the bent portion to the proximal end is longer than the length of a distal body section constituting the portion of the catheter body from the apex of the bent portion to the distal end.

3. 3. The catheter of claim 2, wherein the distal body portion has a length of 30 to 60 cm.

4. 4. The catheter according to claim 3, wherein the length of the catheter body is 70 to 100 cm.

5. 10. The catheter of claim 1, wherein the distal end has a curved tip.

6. a first step of introducing a first catheter from a radial artery and reaching the first catheter to a lesion in a lower limb artery in an antegrade direction of the lower limb artery; a second step of inserting a second catheter into the lower limb artery at the ankle and delivering the second catheter to the lesion in the lower limb artery in a retrograde direction of the lower limb artery, the second catheter has a catheter body having a distal end and a proximal end, a hub connected to the proximal end of the catheter body, and a bending portion located between the distal end and the proximal end of the catheter body and shaped so that the catheter body bends to have a curvature and the distal end approaches the proximal end; A treatment method, wherein in the second step, the bending portion is placed outside the body, and the hub of the second catheter is placed closer to the hub of the first catheter than the lesion.

7. The treatment method according to claim 6, wherein the second step is performed after the first step.

8. 8. The treatment method according to claim 6 or 7, wherein the length of a proximal body portion of the catheter body that constitutes the portion from the apex of the bent portion to the proximal end is longer than the length of a distal body portion of the catheter body that constitutes the portion from the apex of the bent portion to the distal end.

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