WO2024070960A1

WO2024070960A1 - Catheter and treatment method using same

Info

Publication number: WO2024070960A1
Application number: PCT/JP2023/034540
Authority: WO
Inventors: 伊藤隆史
Original assignee: テルモ株式会社
Priority date: 2022-09-30
Filing date: 2023-09-22
Publication date: 2024-04-04

Abstract

A catheter (second catheter (14)) has a catheter body (18) having a distal end (22) and a proximal end (24), a hub (20) connected to the proximal end (24) of the catheter body (18), and a flexure (26) positioned between the distal end (22) and the proximal end (24) of the catheter body (18) and formed so that the catheter body (18) flexes in a horseshoe shape, wherein the length (L2) from the flexure (26) to the proximal end (24) is longer than the length (L1) from the flexure (26) to the distal end (22), and a distal body part (32) from the flexure (26) to the distal end (22) is inserted backward to a lower limb artery while the flexure (26) is placed outside of the body, thereby treating an occlusion site (C) of the lower limb artery.

Description

Catheter and treatment method using same

The present invention relates to a catheter that is percutaneously inserted into a blood vessel to treat a lesion within the blood vessel, and a treatment method using the catheter.

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. When 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, and treatment is performed to penetrate the occlusion site, etc.

In addition, if it is difficult to open the antegrade area, an additional procedure may be performed in which a catheter is introduced into the peripheral part of the lower limb artery at the ankle and the blocked area is opened in the retrograde direction.

U.S. Patent No. 10,159,822 discloses a technique for introducing a catheter in a retrograde direction to treat an obstructed area. Journal of Endovascular Therapy 2022, Vol. 29(2) 215-225 reports on the success rates of a procedure attempting to open an obstructed area in an antegrade direction versus a procedure attempting to open an obstructed area in a retrograde direction.

When inserting a catheter into the arterial blood vessels of the lower limbs in the antegrade direction from the wrist and in the retrograde direction from the ankle, the sites where the two catheters are inserted into the blood vessels are far apart. As a result, with conventional procedures, the surgeon must frequently change position to operate the two catheters and guidewire, making the procedure cumbersome or requiring two surgeons. In addition, an X-ray fluoroscopy device is used to visualize the occluded area, but conventional procedures increase the frequency of work near the X-ray tube, which increases the surgeon's radiation exposure.

The present invention aims to solve the above problems.

(1) The first aspect of the disclosure below is a catheter having a catheter body having a distal end and a proximal end, a hub connected to the proximal end of the catheter body, and a bent 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, and the distal end of the catheter body is inserted in a retrograde manner into a lower limb artery with the bent portion positioned outside the body to treat a diseased portion of the lower limb artery.

The catheter of item (1) above has a bent portion 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 from the retrograde direction can be positioned close to the hub of the catheter introduced from the antegrade direction. Therefore, the catheter described above can reduce the need for the surgeon to move his/her standing position or to work near the X-ray tube.

(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 of item (2) above allows the hubs of the two catheters to be placed side-by-side at the operator's fingertips. In other words, the hub of the catheter of item (2) introduced from the retrograde direction can be placed near the hub of the catheter introduced from the antegrade direction, thereby reducing the operator's movement in standing position and work near the X-ray tube.

(3) In the catheter described in item (2) above, the length of the distal main body may be 30 to 60 cm. The catheter of item (3) can reach the lesion (blockage site) by puncturing the arterial blood vessel of the lower limb from the ankle.

(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) can be arranged such that the hub is located near the hub of the catheter introduced from the antegrade direction, thereby reducing the need for the operator to move around and to work near the X-ray tube.

(5) In the catheter described in any one of items (1) to (4) above, the distal end may have a curved tip shape.

(6) A second aspect of the disclosure below is a treatment method having a first step of introducing a first catheter from the radial artery and reaching the first catheter to the lesion of the 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 to the lesion of the lower limb artery in the retrograde direction of the lower limb artery, in which 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 bent 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, and in the second step, the bent portion is disposed outside the body, and the hub of the second catheter is disposed closer to the hub of the first catheter than the lesion.

The treatment method described in item (6) above allows the surgeon to insert the catheter into the lesion from both the antegrade and retrograde directions while limiting the need for the surgeon to move around or work near the X-ray tube.

(7) In the treatment method described in item (6) above, the second step may be performed after the first step. The treatment method described in item (7) improves the efficiency of treatment because the first catheter is introduced first from the antegrade direction in which a thick catheter can be introduced.

(8) In the treatment method described in item (6) or (7) 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 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 around and work near the X-ray tube.

FIG. 1 is an explanatory diagram showing an outline of a method for treating arterial blood vessels of a lower limb using a first catheter and a second catheter according to an embodiment. FIG. 2 is a plan view of the second catheter and guidewire of FIG. FIG. 3 is an explanatory diagram showing an example of a method for introducing the second catheter into a blood vessel. FIG. 4 is an explanatory diagram showing a method for treating a lesion using a first catheter and a second catheter.

As shown in FIG. 1, the treatment system 10 according to this embodiment is used to treat stenosis in the arteries of the lower limbs, chronic total occlusion (CTO), and other lesions in which the arteries of the lower limbs are narrowed over a long period of time. As shown in the figure, the treatment system 10 has a first catheter 12, a second catheter 14, and an X-ray fluoroscopy device 16.

The first catheter 12 is inserted into an artery from the radial artery in the wrist or the femoral artery in the leg, and is introduced in the antegrade direction to the occlusion site C (lesion site) of the 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 moving from the heart side toward the occlusion site C. Although FIG. 1 shows 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 inside, and accommodates a guidewire 40, a balloon catheter for treatment, etc., so that they can be inserted therethrough. The guidewire 40 is used to open the occlusion site C.

The second catheter 14 is a catheter that is introduced in a retrograde direction when it is difficult to open the occluded area C using the first catheter 12. The retrograde direction is the direction in which blood flows backward 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 area C in a retrograde direction. Details of the second catheter 14 will be described later.

The X-ray fluoroscopy device 16 irradiates the X-ray irradiation area shown in the figure with X-rays to visualize the occlusion site C and the first catheter 12 and the second catheter 14 in the vicinity thereof. Patency of the occlusion site C is performed under imaging by the X-ray fluoroscopy device 16.

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

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 22, a proximal end 24, a bent portion 26, and an inner lumen 28. The distal end 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 22. The tip shape portion 30 is composed of a tubular member shaped to bend, for example, at an obtuse angle.

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 by the hub 20 at the proximal end 24.

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

The catheter body 18 is shaped so that the part of the bent portion 26 that is located farthest from the hub 20 is the apex 26a, and the bent portion 26 is folded back so that the distal end 22 is closer to the hub 20 than the apex 26a of the bent portion 26. In the catheter body 18, the bent portion 26 is located farthest from the hub 20 when the hub 20 is held in the hand. The catheter body 18 has a distal body portion 32 and a proximal body portion 34. The distal body portion 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 portion 34 constitutes the portion of the catheter body 18 from the apex 26a of the bent portion 26 to the proximal end 24.

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

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 that extends 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.

The second catheter 14 having such a proximal body portion 34 can have its hub 20 positioned close to the hub 42 of the first catheter 12, making it possible to reduce the need for the surgeon M to change his/her standing position and to work near the X-ray fluoroscopy device 16. The length L2 of the proximal body portion 34 can be, for example, 30 to 120 cm, more preferably 40 to 110 cm, and is 40 cm in this embodiment.

The shape of the proximal body portion 34 is not limited to a straight line, 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 body portion 32 and the length L2 of the proximal body portion 34, or may be the length from the distal end portion 22 to the proximal end portion 24, but the total length of the catheter body 18 is preferably 70 to 100 cm, and is 70 cm in this embodiment.

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

The hub 20 is connected to the proximal end 24 of the catheter body 18. The hub 20 has an outer diameter that allows the surgeon M to easily grasp it with his/her hand. The hub 20 transmits the operating force of the surgeon M to the catheter body 18. The hub 20 has a hollow portion 36 therein that communicates with the lumen 28 of the catheter body 18. The hub 20 allows the guide wire 38 to be inserted into the lumen 28 of the catheter body 18 through the hollow portion 36.

The guidewire 38 is manipulated through a guidewire hub located near the hub 20 of the second catheter 14. The tip of the guidewire 38 protrudes from the distal end 22 and is inserted retrogradely into the occlusion site C.

The treatment system 10 of this embodiment is configured as described above. Below, a method for treating an occluded area C of a lower limb arterial blood vessel A using the treatment system 10 will be described.

As shown in FIG. 1, the first step is to insert the 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 through the iliac artery, femoral artery, and popliteal artery of either the left or right leg to the lower limb arterial blood vessel A of either the left or right leg.

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. Since 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 arterial blood vessels of either the left or right leg.

Then, 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 pressure is higher, and it may be difficult to open the guidewire 40 from the antegrade direction. In this case, the treatment method proceeds to the second step of inserting the second catheter 14.

The second step includes inserting the second catheter 14 from the distal lower limb artery near the ankle, as shown in FIG. 3. In this case, for example, the second step may include inserting the second catheter 14 into the tibial artery. The second catheter 14 can be grasped by bundling the distal body portion 32 and the proximal body portion 34 as shown in the figure. Also, by grasping the bent portion 26 by wrapping it in the palm of the hand, the operating force can be easily transmitted in the direction of advancing the distal body portion 32. Therefore, the bent portion 26 makes it easy to push the distal body portion 32. By the above operation, the distal end portion 22 of the second catheter 14 is positioned near the occlusion site C of the lower limb arterial blood vessel A, as shown in FIG. 4.

As shown in FIG. 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.

Next, an operation is performed to protrude the guidewire 38 from the distal end 22 of the second catheter 14 through the guidewire hub located at the base end of the hub 20 of the second catheter 14. The guidewire 38 of the second catheter 14 advances in a 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 from both the antegrade and retrograde directions, making it possible to more effectively open the occluded site C of the lower limb arterial blood vessel A.

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 guidewire 38, and can perform the procedure smoothly. In addition, because there is no need to pass near the X-ray fluoroscopy device 16 to operate the guidewire 38 of the second catheter 14, the amount of radiation exposure of the surgeon M can be reduced.

When the guidewire 40 passes through the occlusion site C, the first catheter 12 is advanced by sliding against the guidewire 40, and the first catheter 12 is positioned at the occlusion site C. Then, 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.

The present invention is not limited to the above disclosure, and various configurations may be adopted without departing from the gist 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 that is more peripheral or closer to the heart.

Claims

a catheter body having a distal end and a proximal end;
a hub connected to the proximal end of the catheter body;
a bent portion located between the distal end and the proximal end of the catheter body, the bent portion being shaped so that the catheter body is bent with a curvature such that the distal end approaches the proximal end,
The distal end of the catheter body is inserted retrograde into a lower limb artery with the bent portion positioned outside the body to treat a diseased portion of the lower limb artery.
The catheter according to claim 1, wherein 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 is 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 according to claim 2, wherein the length of the distal body portion is 30 to 60 cm.
The catheter according to claim 3, wherein the length of the catheter body is 70 to 100 cm.
The catheter of claim 1, wherein the distal end portion has a curved tip shape.
a first step of introducing a first catheter from a radial artery and allowing the first catheter to reach a lesion in a lower limb artery from 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 allowing the second catheter to reach the lesion in the lower limb artery from 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 bent portion located between the distal end and the proximal end of the catheter body and shaped such that the catheter body is bent with a curvature so that 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.
The treatment method according to claim 6, in which the second step is performed after the first step.
The treatment method according to claim 6 or 7, wherein 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 is 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.