JPWO2020162286A1 - Extension catheter and its manufacturing method - Google Patents

Abstract

Provided are an extension catheter into which an endovascular treatment instrument can be easily inserted, and a method for manufacturing the extension catheter. An extension catheter that is inserted into a tubular catheter and can protrude from the distal opening of the tubular catheter, and has a tubular portion and a first tapered portion located proximal to the tubular portion. The first tapered portion has an outer surface and a first tapered surface, and the second tapered portion has an outer surface and a second tapered portion. An extension catheter having a tapered surface and satisfying the following formulas (1) and (2). 90 ° ≤ θ1 ≤ 145 ° ... (1) 120 ° ≤ θ2 ≤ 175 ° ... (2) [In the equation, θ1 is formed by the first tapered surface and the axial direction of the cylindrical portion. Indicates the angle. θ2 indicates the angle formed by the second tapered surface and the axial direction. ]

Description

The present invention relates to an extension catheter and a method for manufacturing the extension catheter.

Percutaneous coronary angioplasty to dilate the narrowed part of the coronary artery of the heart and increase blood flow using an intravascular treatment device such as a stent or balloon for ischemic heart disease such as angina pectoris and myocardial infarction. (PCI) is being performed. At this time, generally, the tip of the tubular guiding catheter is inserted into the entrance of the coronary artery and placed, and then the endovascular treatment device is delivered through the guiding catheter to insert the endovascular treatment device into the peripheral side of the coronary artery. I was improving my sex. However, when the backup force is small and the indwelling is unstable, the tip of the guiding catheter may come off from the entrance of the coronary artery. In that case, the backup force was improved by inserting a small-diameter extension catheter into the guiding catheter and projecting it from the distal opening of the guiding catheter.

Various such extension catheters are known, for example, a proximal member including an extension portion of Patent Document 1, a collar member attached to the extension portion, and a distal sheath member attached to the collar member. Guide extension catheters with are known. In addition, a push member including a portion having a first surface on which a groove of Patent Document 2 is formed and a second surface on the opposite side thereof, and a distal shaft having a passage adjacent to the push member are provided. Guide extension catheters are known. Further, a distal shaft constituting the distal end side portion of Patent Document 3 and a proximal shaft constituting the proximal end side portion are provided, and the proximal shaft is connected to the proximal end side portion of the distal shaft by a modified polyolefin adhesive. Support catheters are known. Further, a coaxial guide catheter that can be delivered through the guide catheter by using the guide wire rail segment of Patent Document 4, a tip sheath of Patent Document 5, a proximal shaft, and a distal sheath on the proximal shaft. Guide extension catheters are known that include a coupling member to be immobilized.

International Publication No. 2018/075700 International Publication No. 2017/214209 International Publication No. 2018/030075 U.S. Pat. No. 8292850 Japanese Patent Publication No. 2015-523186

Conventionally, endovascular treatment instruments such as stents and balloons have been inserted into the extension catheter through the proximal opening of the extension catheter in the artery, but the endovascular treatment instrument is inserted into the extension catheter. It was sometimes difficult. The present invention has been made by paying attention to the above-mentioned problems, and an object of the present invention is to provide an extension catheter into which an endovascular treatment instrument can be easily inserted, and a method for manufacturing the same.

The extension catheter according to the present invention, which has been able to solve the above problems, and a method for manufacturing the same are as follows.
[1] An extension catheter that can be inserted into a tubular catheter and protrudes from the distal opening of the tubular catheter.
A tubular portion, a first tapered portion located proximal to the tubular portion, and a second tapered portion located proximal to the first tapered portion are provided.
The first tapered portion has an outer surface and a first tapered surface.
The second tapered portion has an outer surface and a second tapered surface.
An extension catheter characterized by satisfying the following formulas (1) and (2).
90 ° ≤ θ ₁ ≤ 145 ° ・ ・ ・ (1)
120 ° ≤ θ ₂ ≤ 175 ° ・ ・ ・ (2)
[In the equation, θ ₁ indicates the angle formed by the first tapered surface and the axial direction of the tubular portion. θ ₂ indicates the angle formed by the second tapered surface and the axial direction. ]
[2] The extension catheter according to [1], which satisfies the following formula (3).
θ ₁ <θ ₂ ... (3)
[In the equation, θ ₁ and θ ₂ have the same meaning as before. ]
[3] The extension catheter according to [1] or [2], which satisfies the following formula (4).
T ≤ H ₁ ≤ H ₂ ... (4)
[In the formula, T indicates the thickness (mm) of the tubular portion at the distal end of the first tapered portion. H ₁ shows the radial length between the farthest point and the point closest to the central axis of the tubular portion of the first tapered surface (mm). H ₂ indicates the radial length (mm) of the point closest to the central axis and the point farthest from the central axis of the tubular portion of the second tapered surface. ]
[4] The extension catheter according to any one of [1] to [3], which satisfies the following formula (5).
0.3D ≤ D ₂ ... (5)
[In the formula, D indicates the outer diameter (mm) of the tubular portion at the distal end of the first tapered portion. D ₂ indicates the radial length at the proximal end of the second tapered portion. ]
[5] Further, a third tapered portion located proximal to the second tapered portion is provided.
The third tapered portion has an outer surface and a third tapered surface.
The extension catheter according to any one of [1] to [4], which satisfies the following formula (6).
-5 ° ≤ θ ₃ ≤ 5 ° ... (6)
[In the equation, θ ₃ indicates the angle formed by the third tapered surface and the axial direction. ]
[6] A reinforcing layer is provided on the cylindrical portion.
The extension catheter according to any one of [1] to [5], which satisfies the following formula (7).
D ≤ L ₄ ≤ 3D ... (7)
[In the formula, D indicates the outer diameter (mm) of the tubular portion at the distal end of the first tapered portion. L ₄ is a show from the proximal end of the reinforcing layer length in the axial direction to the distal end of the first taper portion (mm). ]
[7] A step of making a notch in the tubular member to form a first tapered surface, and a step of making a notch from the proximal side to the distal side of the first tapered surface to form a second tapered surface. ,
A method for manufacturing an extension catheter, which comprises.

The present invention can provide an extension catheter into which an endovascular treatment instrument can be easily inserted, and a method for manufacturing the extension catheter, according to the above configuration.

FIG. 1 is a side view of an extension catheter according to an embodiment of the present invention. FIG. 2 is an axial sectional view of the R portion of FIG. FIG. 3A is a side view of the extension catheter. FIG. 3B is a side view when a part of the extension catheter is bent. FIG. 3C is a side view of the extension catheter according to the embodiment of the present invention. FIG. 3D is a side view when a part of the extension catheter according to the embodiment of the present invention is bent. FIG. 4 shows a sectional view taken along the line IV-IV of FIG. FIG. 5 shows a VV cross-sectional view of FIG. FIG. 6 shows a sectional view taken along line VI-VI of FIG. FIG. 7 shows a sectional view taken along line VII-VII of FIG. FIG. 8 is a diagram showing a state when the extension catheter according to the embodiment of the present invention is inserted into the tubular catheter and protrudes from the distal opening of the tubular catheter.

Hereinafter, the present invention will be described in more detail based on the following embodiments, but the present invention is not limited by the following embodiments as well as the present invention, and is appropriately modified to the extent that it can meet the purposes of the preceding and the following. Of course, it is also possible to carry out the above, and all of them are included in the technical scope of the present invention. In each drawing, the member code and the like may be omitted for convenience, but in such a case, the specification and other drawings shall be referred to. Further, the dimensions of the various members in the drawings may differ from the actual dimensions because the priority is given to contributing to the understanding of the features of the present invention.

First, the extension catheter according to the embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG. 1 shows a side view of an extension catheter according to an embodiment of the present invention. FIG. 2 is an axial sectional view of the R portion of FIG. FIG. 3A is a side view of the extension catheter. FIG. 3B is a side view when a part of the extension catheter is bent. FIG. 3C is a side view of the extension catheter according to the embodiment of the present invention. FIG. 3D is a side view when a part of the extension catheter according to the embodiment of the present invention is bent. 4 to 7 show an IV-IV sectional view, a VV sectional view, a VI-VI sectional view, and a VII-VII sectional view of FIG. 1, respectively. FIG. 8 is a diagram showing a state when the extension catheter according to the embodiment of the present invention is inserted into the tubular catheter and protrudes from the distal opening of the tubular catheter. In FIG. 2, the description of the radiation opaque marker is omitted.

The extension catheter 30 according to the embodiment of the present invention shown in FIG. 1 is an extension catheter that is inserted into the tubular catheter 40 as shown in FIG. 8 and can protrude from the opening a40 on the distal side of the tubular catheter 40. be. Further, as shown in FIG. 2, the extension catheter 30 is located on the tubular portion 4, the first tapered portion 1 located proximal to the tubular portion 4, and the proximal side to the first tapered portion 1. The second tapered portion 2 is provided. The first tapered portion 1 has an outer surface S10 and a first tapered surface S1, and the second tapered portion 2 has an outer surface S10 and a second tapered surface S2. Further, the extension catheter 30 is formed so as to satisfy the following formulas (1) and (2).
90 ° ≤ θ ₁ ≤ 145 ° ・ ・ ・ (1)
120 ° ≤ θ ₂ ≤ 175 ° ・ ・ ・ (2)
[In the equation, θ ₁ indicates the angle formed by the first tapered surface S1 and the axial direction X of the tubular portion 4. In the equation, θ ₂ indicates the angle formed by the second tapered surface S2 and the axial direction X of the tubular portion 4. ]

In the present invention, the proximal side means the direction toward the operator's hand side with respect to the extending direction of the extension catheter 30, and the direction opposite to the distal side, that is, the direction toward the treatment target side. means.

The extension catheter 30 according to the embodiment of the present invention is characterized in that the first tapered surface S1 and the second tapered surface S2 are formed so as to satisfy the above equations (1) and (2). .. Specifically, in the conventional extension catheter, as in Patent Document 3, a tapered surface is provided at an angle exceeding 90 ° with respect to the axial direction of the tubular portion to form an opening having a large opening area. In some cases, endovascular treatment devices such as stents and balloons can be easily inserted into the extension catheter. However, if the angle of the tapered surface with respect to the axial direction of the tubular portion becomes too large, a thin-walled portion will be formed in the tubular portion at the distal end of the tapered portion, and the endovascular treatment device will be easily caught in the thin-walled portion. There was a problem. On the other hand, in the present invention, the thin portion is reduced by forming the tapered surface having a small angle with respect to the axial direction of the tubular portion, that is, the first tapered surface S1 satisfying the above formula (1). _{Further, since the thin portion is reduced, the angle θ 2} formed by the second tapered surface S2 and the axial direction X of the tubular portion 4 can be increased to the range specified in the above equation (2). It is possible to easily increase the opening area of the opening. As a result, the endovascular treatment device can be easily inserted into the extension catheter.

In the following, each equation will be mainly described.
90 ° ≤ θ ₁ ≤ 145 ° ・ ・ ・ (1)
[In the equation, θ ₁ indicates the angle formed by the first tapered surface S1 and the axial direction X of the tubular portion 4. ]
_{By setting the angle θ 1} formed by the first tapered surface S1 and the axial direction X of the tubular portion 4 to 145 ° or less, it is possible to reduce the thin portion and make it difficult for the endovascular treatment device to be caught. Therefore, θ ₁ is preferably 140 ° or less, more preferably 130 ° or less, and even more preferably 120 ° or less. On the other hand, by _{setting θ 1} to 90 ° or more, it is possible to easily increase the opening area of the opening for inserting the endovascular treatment instrument. Therefore, θ ₁ is preferably 95 ° or more, more preferably 100 ° or more, and even more preferably 110 ° or more.

120 ° ≤ θ ₂ ≤ 175 ° ・ ・ ・ (2)
[In the equation, θ ₂ indicates the angle formed by the second tapered surface S2 and the axial direction X of the cylindrical portion 4. ]
_{The angle θ 2} formed by the second tapered surface S2 and the axial direction X of the tubular portion 4 is 120 ° or more. This makes it possible to easily increase the opening area of the opening for inserting the endovascular treatment instrument. Therefore, θ ₂ is preferably 130 ° or more, more preferably 140 ° or more, and further preferably 150 ° or more. On the other hand, _{the upper limit of θ 2} may be, for example, 175 °, 170 °, or 168 °.

Further, the extension catheter 30 preferably satisfies the following formula (3).
θ ₁ <θ ₂ ... (3)
[In the equation, θ ₁ and θ ₂ have the same meaning as before. ]
It is preferable that the _{angle θ 2} formed by the second tapered surface S2 and the axial direction X of the _{tubular portion 4 is larger than the angle θ 1} formed by the first tapered surface S1 and the axial direction X of the tubular portion 4. As a result, it is possible to easily increase the opening area of the opening for inserting the endovascular treatment instrument while reducing the thin portion. theta ₂ is more preferably theta ₁ 1.1 times or more, more preferably theta ₁ 1.2 times or more, and even more preferably theta ₁ 1.3 times or more. On the other hand, the upper limit of theta ₂ may be equal to or less than 1.5 times the example theta _1, may be not more than 1.4 times the theta _1.

Further, the extension catheter 30 preferably satisfies the following formula (4).
T ≤ H ₁ ≤ H ₂ ... (4)
[In the formula, T indicates the thickness (mm) of the tubular portion 4 at the distal end A1 of the first tapered portion 1. H ₁ shows the radial length of the farthest point F1 closest point N1 to the center axis of the cylindrical portion 4 of the first tapered surface S1 C a (mm). H ₂ indicates the radial length (mm) of the point N2 closest to the central axis C of the tubular portion 4 of the second tapered surface S2 and the point F2 farthest from the central axis C. ]
Tubular portion radial length H ₁ between the center axis point closest to C N1 farthest point F1 of 4 of the first taper surface S1 is a cylindrical portion at the distal end A1 of the first taper portion 1 4 It is preferable that the thickness is T or more. This makes it easier to reduce the thin wall portion. H ₁ is more preferably 1.1 times or more of T, further preferably 1.2 times or more of T, and even more preferably 1.3 times or more of T. On the other hand, it is preferable that _{H 1 has a radial length H 2} or less of the point N2 closest to the central axis C of the tubular portion 4 of the second tapered surface S2 and the point F 2 farthest from the central axis C. This makes it easy to avoid contact between the first tapered surface S1 and the endovascular treatment instrument. Therefore, H ₁ is more preferably 0.5 times or less of _{H 2} , and even more preferably 0.4 times or less of _{H 2.}

T is preferably 0.01 mm or more and 0.3 mm or less, more preferably 0.02 mm or more and 0.2 mm or less, and further preferably 0.05 mm or more and 0.1 mm or less. H ₁ is preferably 0.02mm or more, 0.4 mm or less, more preferably 0.05mm or more, 0.3 mm or less, more preferably 0.1mm or more and 0.25mm or less. H ₂ is preferably 0.1 mm or more and 1.5 mm or less, more preferably 0.2 mm or more and 1 mm or less, and further preferably 0.4 mm or more and 0.7 mm or less.

Further, the extension catheter 30 preferably satisfies the following formula (5).
0.3D ≤ D ₂ ... (5)
[In the formula, D indicates the outer diameter (mm) of the tubular portion 4 at the distal end A1 of the first tapered portion 1. D ₂ indicates the radial length at the proximal end B2 of the second tapered portion 2. ]
_{The radial length D 2} at the proximal end B2 of the second tapered portion 2 is preferably 0.3 times or more the outer diameter D of the tubular portion 4 at the distal end A1 of the first tapered portion 1. .. This makes it easy to avoid local bending in the vicinity of the proximal end B2 of the second tapered portion 2. D ₂ is more preferably 0.4 times or more of D. On the other hand, D ₂ is preferably 0.8 times or less of D. This makes it possible to easily increase the opening area of the opening for inserting the endovascular treatment instrument. Therefore, D ₂ is more preferably 0.7 times or less of D, and further preferably 0.6 times or less of D.

D is preferably 0.5 mm or more and 4 mm or less, more preferably 1 mm or more and 2 mm or less, still more preferably 1.4 mm or more and 1.8 mm or less. D ₂ is preferably 0.2 mm or more and 2 mm or less, more preferably 0.5 mm or more and 1.5 mm or less, and further preferably 0.8 mm or more and 1.2 mm or less.

Further, the extension catheter 30 preferably includes a third tapered portion 3 located proximal to the second tapered portion 2. The third tapered surface 3 has an outer surface S10 and a third tapered surface S3. By providing the third tapered portion 3, the endovascular treatment instrument can be easily inserted into the opening along the third tapered portion 3.

Further, the extension catheter 30 preferably satisfies the following formula (6).
-5 ° ≤ θ ₃ ≤ 5 ° ... (6)
[In the equation, θ ₃ indicates the angle formed by the third tapered surface S3 and the axial direction X of the tubular portion 4. ]
_{As shown in the above equation (6), the angle θ 3} (not shown) formed by the third tapered surface S3 and the axial direction X of the cylindrical portion 4 shall be −5 ° or more and 5 ° or less. That is, since the third tapered surface S3 and the axial direction X of the tubular portion 4 are substantially parallel to each other, it is possible to easily insert the endovascular treatment device into the opening along the third tapered portion 3. It is more preferably -3 ° or more and 3 ° or less, still more preferably -2 ° or more and 2 ° or less, and even more preferably -1 ° or more and 1 ° or less.

When the tubular portion 4 includes the reinforcing layer 13 described later, it is preferable that the following formula (7) is satisfied.
D ≤ L ₄ ≤ 3D ... (7)
[In the formula, D indicates the outer diameter (mm) of the tubular portion 4 at the distal end A1 of the first tapered portion 1. L ₄ is a show from the proximal end B13 of the axial direction X to the distal end A1 of the first taper portion 1 Length (mm) of the reinforcing layer 13. ]
The proximal length in the axial direction X of the cylindrical portion 4 of the end B13 to the first distal end A1 of the tapered portion 1 L ₄ is, the cylindrical portion at the distal end A1 of the first taper portion 1 of the reinforcing layer 13 It is preferable that the outer diameter is D or more of 4. L ₄ corresponds to the length of the tubular portion 4 of the non-reinforcing portion 5 of the tubular portion 4 in which the reinforcing layer 13 is not provided in the axial direction X, and when this is D or more, the blood vessel It is possible to easily avoid deformation of the opening for inserting the internal treatment instrument. Therefore, L ₄ is preferably 1.5 times or more of D, and more preferably 2 times or more of D. On the other hand, when L ₄ is 3 times or less of D, it is possible to easily avoid deformation of the non-reinforcing portion 5. L ₄ is more preferably 2.8 times or less of D.

Specifically, L ₄ is preferably 0.5 mm or more and 8 mm or less, more preferably 2 mm or more and 6 mm or less, and further preferably 3 mm or more and 5 mm or less.

Further, the extension catheter 30 preferably satisfies the following formula (8).
10D ≤ L ₃ ≤ 200D ... (8)
[In the formula, D indicates the outer diameter (mm) of the tubular portion 4 at the distal end A1 of the first tapered portion 1. L ₃ indicates the length (mm) of the tubular portion 4 in the axial direction X from the distal end of the third tapered portion 3 to the proximal end of the third tapered portion 3. ]
The third distal end of the tapered portion 3 proximal end of the axial direction X of the tubular portion 4 up (not shown) the length L ₃ from (not shown) the third tapered portion 3, the first tapered portion It is preferable that the outer diameter D of the tubular portion 4 at the distal end A1 of 1 is 10 times or more. As a result, the contact area between the third tapered portion 3 and the linear member 20 can be easily increased, and the linear member 20 can be easily fixed firmly. L ₃ is more preferably 30 times or more the outer diameter D, and further preferably 60 times or more the outer diameter D. On the other hand, L ₃ is preferably 200 times or less the outer diameter D. This makes it possible to improve the flexibility of the linear member 20. L ₃ is more preferably 120 times or less the outer diameter D, and further preferably 90 times or less the outer diameter D.

Specifically, L ₃ is preferably 5 cm or more and 20 cm or less, more preferably 10 cm or more and 18 cm or less, and further preferably 12 cm or more and 15 cm or less.

Further, the extension catheter 30 preferably satisfies the following formula (9).
120 ° ≤ θ ₄ ≤ 175 ° ... (9)
[In the equation, θ ₄ indicates the angle formed by the second tapered surface S2 and the third tapered surface S3. ]
_{As shown in FIG. 3A, in an extension catheter in which the angle θ 4} formed by the second tapered surface S2 and the third tapered surface S3 is less than 120 °, the second taper as shown in FIG. 3B at the curved portion in the artery or the like. Local bending is likely to occur at the proximal end B2 of the portion. On the other hand, as shown in FIG. 3C, the angle between the second tapered surface S2 and the third tapered surface S3 with respect to the axial direction X of the tubular portion 4 is smoothly changed by setting _{θ 4 to 120 ° or more.} As shown in 3D, local bending at the proximal end B2 of the second tapered portion can be facilitated. As a result, the endovascular treatment instrument can be easily inserted. Therefore, θ ₄ is preferably 130 ° or more, more preferably 140 ° or more, and further preferably 150 ° or more. On the other hand, _{the upper limit of θ 4} may be, for example, 175 ° or 168 °.

The preferred dimensions of the other parts are as follows. _{The length L 1 in} the axial direction X from the point F1 farthest to the central axis C of the cylindrical portion 4 of the first tapered surface S1 to the point N1 closest to the central axis C of the tubular portion 4 of the first tapered surface S1. Is preferably 0 mm or more and 0.3 mm or less, more preferably 0.02 mm or more and 0.25 mm or less, and further preferably 0.05 mm or more and 0.2 mm or less.

_{The length L 2 in} the axial direction X from the point F2 farthest to the central axis C of the tubular portion 4 of the second tapered surface S2 to the point N2 closest to the central axis C of the tubular portion 4 of the second tapered surface S2. Is preferably 0.5 mm or more, 6 mm or less, more preferably 1 mm or more and 4 mm or less, still more preferably 1.5 mm or more and 3 mm or less.

_{The radial length D 1} at the proximal end B1 of the first tapered portion 1 is preferably 0.5 mm or more, 2.5 mm or less, more preferably 1 mm or more and 2 mm or less, still more preferably 1.3 mm or more, 1 It is 0.7 mm or less.

The length of the axial X from the distal end (not shown) to the proximal end (not shown) of the tubular portion 4 is preferably 10 cm or more, 50 cm or less, more preferably 20 cm or more, 40 cm or less, and further. It is preferably 25 cm or more and 35 cm or less.

Next, each member of the extension catheter 30 will be described in detail. As shown in FIGS. 1 and 2, the extension catheter 30 is located on the tubular portion 4, the first tapered portion 1 located proximal to the tubular portion 4, and the proximal side to the first tapered portion 1. The second tapered portion 2 is provided.

The extension catheter 30 is inserted into the tubular catheter 40, for example, through the proximal opening b40 of the tubular catheter 40 shown in FIG. The tubular catheter 40 has a distal end A40 and a proximal end B40, and the distal end A40 and the proximal end B40 are provided with openings a40 and b40, respectively. The tubular catheter 40 may be a guiding catheter. The extension catheter 30 has a distal end A30, and the distal end A30 of the extension catheter 30 is inserted through the proximal opening b40 of the tubular catheter 40. As shown in FIG. 8, the distal portion of the extension catheter 30 can be projected from the opening a40 on the distal side of the tubular catheter 40, or can be pulled back. The extension catheter 30 is inserted into the tubular catheter 40 previously placed in the body cavity to allow the device passing through the tubular catheter 40 and the extension catheter 30 to reach the distal side of the body cavity. Used. The inner diameter of the tubular catheter 40 is larger than the outer diameter of the extension catheter 30 in order to receive the extension catheter 30 in the lumen. Further, as shown in FIG. 1, the extension catheter 30 preferably has a shape in which a distal member 10 including a tubular portion 4 and a tapered portion on the distal side and a rod-shaped linear member 20 are connected. As shown in FIG. 8, it is preferable that the linear member 20 of the extension catheter 30 is used without protruding from the opening a40 on the distal side of the tubular catheter 40. The length of the extension catheter 30 can be, for example, 1500 mm, and the length of the distal member 10 of the extension catheter 30 can be, for example, 350 mm. The diameter of the distal end of the distal member 10 of the extension catheter 30 can be, for example, 1.5 mm. By using the extension catheter 30, the treatment device can be used by projecting from the opening a30 of the distal end A30 of the extension catheter via the tubular catheter 40 and the extension catheter 30. The device for treatment enters the tubular catheter 40 through the proximal opening b40 of the tubular catheter 40, enters the extension catheter 30 through the proximal opening of the extension catheter 30, and enters the extension catheter 30 distally. It can protrude from the opening a30 of.

The inner diameter of the tubular portion 4 is preferably 1.0 mm or more and 2.2 mm or less. Since the inner diameter of the tubular portion 4 is 2.2 mm or less, the shape of the opening for inserting the endovascular treatment instrument is less likely to be deformed. It is more preferably 2.0 mm or less, still more preferably 1.8 mm or less. On the other hand, by setting the inner diameter of the tubular portion 4 to 1.0 mm or more, the endovascular treatment instrument can easily pass through the tubular portion 4. It is more preferably 1.2 mm or more, still more preferably 1.4 mm or more.

The outer diameter of the tubular portion 4 is preferably 1.2 mm or more and 3 mm or less. When the outer diameter of the tubular portion 4 is 3 mm or less, the tubular portion 4 can be easily inserted into the guiding catheter or the blood vessel. It is more preferably 2 mm or less, still more preferably 1.8 mm or less. On the other hand, by setting the outer diameter of the tubular portion 4 to 1.2 mm or more, it is possible to easily improve the strength of the tubular portion 4. It is more preferably 1.4 mm or more, still more preferably 1.6 mm or more.

As shown in FIG. 2, the tubular portion 4 preferably includes an inner layer 11. Examples of the material constituting the inner layer 11 include resin. As the resin, for example, at least one selected from the group consisting of polyamide-based resin, polyester-based resin, polyurethane-based resin, polyolefin-based resin, fluororesin, vinyl chloride-based resin, silicone-based resin, and natural rubber is preferable. Of these, at least one selected from the group consisting of polyester-based resin, polyolefin-based resin, fluorine-based resin, silicone-based resin, and natural rubber is more preferable. Of these, the fluororesin is particularly preferable because it is excellent in chemical resistance, non-adhesiveness, and low frictional property.

Examples of the polyamide resin include nylon 12, nylon 12 elastomer, nylon 6, aromatic polyamide and the like. Examples of the polyester resin include polyethylene terephthalate and the like. Examples of the polyurethane resin include an aliphatic polyurethane containing an aliphatic isocyanate as a monomer unit, an aromatic polyurethane containing an aromatic isocyanate as a monomer unit, and the like. Examples of the polyolefin resin include polyethylene and polypropylene. Examples of the fluororesin include polytetrafluoroethylene, ethylene tetrafluoroethylene, fluorinated ethylene propylene and the like. Examples of the vinyl chloride resin include polyvinyl chloride and polyvinylidene chloride. Examples of the silicone-based resin include dimethylpolysiloxane, methylphenylpolysiloxane, methylvinylpolysiloxane, fluoroalkylmethylpolysiloxane and the like. Examples of natural rubber include latex and the like.

A part or all of the inner layer 11 may contain a radiation-impermeable substance described later in order to make it easier to confirm the position of the tubular portion 4 under fluoroscopy or the like.

The tubular portion 4 preferably includes an outer layer 12. Examples of the material constituting the outer layer 12 include resin. As the resin, for example, at least one selected from the group consisting of polyamide-based resin, polyester-based resin, polyurethane-based resin, polyolefin-based resin, fluororesin, vinyl chloride-based resin, silicone-based resin, and natural rubber is preferable. Of these, at least one selected from the group consisting of a polyamide-based resin, a polyurethane-based resin, and a polyolefin-based resin is more preferable, and at least one selected from the group consisting of a polyamide-based resin and a polyurethane-based resin is further preferable. Polyurethane-based resins are even more preferred.

A part or all of the outer layer 12 may contain a radiation-impermeable substance in order to make it easier to confirm the position of the tubular portion 4 under fluoroscopy or the like. Examples of the radiation impermeable substance include lead, barium, iodine, tungsten, gold, platinum, iridium, platinum iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, tantalum and the like.

The outer surface of the outer layer 12 is preferably coated with a hydrophilic polymer. This makes it easy to insert the tubular portion 4 into the guiding catheter or the blood vessel. Examples of the hydrophilic polymer include hydrophilic polymers such as maleic anhydride copolymer such as poly2-hydroxyethyl methacrylate, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymer.

The tubular portion 4 preferably includes a reinforcing layer 13. The reinforcing layer 13 can improve the rigidity of the tubular portion 4. In FIGS. 2 and 4, the reinforcing layer 13 is provided in the outer layer 12, but the reinforcing layer 13 may be provided in the inner layer 11 or the reinforcing layer 13 may be provided between the inner layer 11 and the outer layer 12. .. Of these, it is particularly preferable that the reinforcing layer 13 is provided in the outer layer 12 because the strength is likely to be improved if the reinforcing layer 13 is provided in the outer layer 12.

Examples of the material constituting the reinforcing layer 13 include metal wires and fibers. As the material constituting the metal wire, for example, stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy and the like, tungsten alloy and the like are preferable. Of these, stainless steel is more preferable. The metal wire may be a single wire or a stranded wire. Examples of the fiber include polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, carbon fiber and the like. The fiber may be a monofilament or a multifilament.

The shape of the reinforcing layer 13 is not particularly limited, but a spiral shape, a mesh shape, or a braided shape is preferable. Of these, the shape of the reinforcing layer 13 is more preferably a braided shape because the braided shape tends to improve the rigidity.

The reinforcing layer 13 may contain the above-mentioned radiation-impermeable substance in order to make it easy to confirm the position of the tubular portion 4 under fluoroscopy or the like.

As shown in FIG. 1, it is preferable that the tip portion of the tubular portion 4 is provided with a radiation opaque marker 14. Specifically, the radiation opaque marker 14 is preferably provided at a portion within 50 mm from the distal end of the tubular portion 4 at a distance X in the axial direction of the tubular portion 4, preferably within 20 mm. It is more preferable that it is provided in a portion within 5 mm, and it is further preferable that it is provided in a portion within 5 mm. This makes it easier to confirm the position of the distal end of the tubular portion 4 in the artery.

As shown in FIG. 1, it is preferable that the radiation opaque marker 14 is provided on the proximal side of the tubular portion 4. Specifically, it is preferable that the radiation opaque marker 14 is provided at a portion within 50 mm from the proximal end B13 of the reinforcing layer 13 at a distance X in the axial direction of the tubular portion 4. It is more preferably within 20 mm from the proximal end B13 of the reinforcing layer 13, and even more preferably within 5 mm from the proximal end B13 of the reinforcing layer 13. This makes it easier to confirm the position of the proximal portion of the tubular portion 4 in the artery.

The shape of the radiation opaque marker 14 is not particularly limited, and examples thereof include a band shape and a spiral shape. Examples of the material constituting the radiation opaque marker 14 include the radiation opaque substance.

When the tubular portion 4 includes the radiation opaque marker 14, it is preferable that the following formula (10) is satisfied.
D ≤ L ₅ ≤ 3D ... (10)
[In the formula, D indicates the outer diameter (mm) of the tubular portion 4 at the distal end A1 of the first tapered portion 1. L ₅ indicates the length (mm) of the tubular portion 4 in the axial direction X from the proximal end of the radiation opaque marker 14 to the distal end A1 of the first tapered portion 1. ]
The proximal end of the radiopaque marker 14 length in the axial direction X of the tubular portion 4 from (not shown) to a first distal end A1 of the tapered portion 1 L _{5 (not} shown), the first taper It is preferable that the outer diameter D or more of the tubular portion 4 at the distal end A1 of the portion 1. When L ₅ is D or more, it is possible to easily avoid deformation of the opening for inserting the endovascular treatment instrument. Therefore, L ₅ is preferably 1.5 times or more of D, and more preferably 2 times or more of D. On the other hand, when L ₅ is 3 times or less of D, it is possible to easily avoid deformation of the non-reinforcing portion 5. L ₅ is more preferably 2.8 times or less of D.

Further, in FIG. 2, the extension catheter 30 includes a third tapered portion 3 located proximal to the second tapered portion 2. Specifically, the extension catheter 30 includes a distal member 10 including a tubular portion 4, a first tapered portion 1, a second tapered portion 2, and a third tapered portion 3. Further, a linear member 20 is fixed to the distal member 10, and a gripping member 21 is provided on the proximal side of the linear member 20.

The first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 each have an outer surface S10. The radial cross-sectional shape of the outer surface S10 of these tapered portions is stepped from a circular shape as shown in FIG. 5 to a circular shape as shown in FIG. 6 from the first tapered portion 1 to the third tapered portion 3. It is preferable that the object changes.

As shown in FIG. 2, it is preferable that the first tapered surface S1 and the second tapered surface S2 are adjacent to each other. However, another tapered surface may be provided between the first tapered surface S1 and the second tapered surface S2.

As shown in FIG. 2, it is preferable that the second tapered surface S2 and the third tapered surface S3 are adjacent to each other. However, another tapered surface may be provided between the second tapered surface S2 and the third tapered surface S3.

The first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 preferably contain a resin, and more preferably made of a resin.

It is preferable that the first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 each include an inner layer 11. As the material constituting these, the material of the inner layer 11 of the tubular portion 4 can be referred to. It is preferable that the material of the inner layer 11 of the first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 is the same as the material of the inner layer 11 of the tubular portion 4, respectively.

It is preferable that the first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 each include an outer layer 12. As the material constituting these, the material of the outer layer 12 of the tubular portion 4 can be referred to. The material of the outer layer 12 of the first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 may be the same as or different from the material of the outer layer 12 of the tubular portion 4, respectively. It is preferable that the outer layer 12 of the first tapered portion 1, the second tapered portion 2, and the third tapered portion 3 each contains the same resin. This makes it easy to avoid local bending of the tapered portion.

The outer layer 12 of the first tapered portion 1, the outer layer 12 of the second tapered portion 2, and the outer layer 12 of the third tapered portion 3 are each included in the portion of the outer layer 12 of the tubular portion 4 where the reinforcing layer 13 exists. It is preferable that a resin having a higher shore hardness is contained than the resin. As a result, it is possible to easily prevent deformation of the opening for inserting the endovascular treatment instrument while ensuring the flexibility of the tubular portion 4.

The shore hardness can be measured based on the ISO868: 2003 plastic durometer hardness test method using a type D durometer.

The linear member 20 is a long wire rod. The linear member 20 pushes the tubular portion 4 to project the tubular portion 4 from the opening of the tubular catheter (not shown). As the material constituting the linear member 20, for example, stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy and the like, tungsten alloy and the like are preferable. Of these, stainless steel is more preferable. The cross-sectional shape of the linear member 20 in the thickness direction is not limited to the shape shown in FIGS. 4 to 7, and examples thereof include a square, a rectangle, a trapezoid, and a circle. Of these, a rectangle is preferable.

As shown in FIG. 1, the gripping member 21 is attached to the proximal end of the linear member 20 and is shaped so that the practitioner can grip it with a finger. Examples of the material constituting the gripping member 21 include resins, and examples of the resin include polyolefin resins such as polyethylene and polypropylene.

Next, a method of manufacturing the extension catheter 30 according to the embodiment will be described. As a method for manufacturing the extension catheter 30, a step of making a notch in the tubular member to form the first tapered surface S1 and a second step of making a notch from the proximal side to the distal side of the first tapered surface S1. Examples thereof include a manufacturing method including a step of forming the tapered surface S2.

In the step of forming the first tapered surface S1, it is preferable to make a notch at an angle satisfying the above formula (1). This makes it easier to form the second tapered surface S2 so as to satisfy the above formula (2).

In the step of forming the second tapered surface S2, it is preferable to make a notch at an angle satisfying the above formula (2). In the step of forming the second tapered surface S2, a notch is made from the proximal side to the distal side of the first tapered surface S1 to form the second tapered surface S2, thereby forming the second tapered surface in a planar shape. It is possible to facilitate the formation of S2. However, a notch may be made from the distal end of the first tapered surface S1 toward the proximal side. In this case, the first tapered surface S1 and the second tapered surface S2 can be formed by continuously making cuts. Further, in the step of forming the second tapered surface S2, it is more preferable to make a notch at an angle satisfying the above formula (3).

Further, it is preferable to include a step of forming a third tapered surface S3 by making a notch from the proximal side to the distal side of the second tapered surface S2. By making a notch from the proximal side to the distal side of the second tapered surface S2, it is possible to facilitate the formation of the third tapered surface S3 in a planar shape. However, a notch may be made from the distal end of the second tapered surface S2 toward the proximal side. In this case, the second tapered surface S2 and the third tapered surface S3 can be formed by continuously making cuts.

When making these cuts, a cutting tool such as a cutter may be used.

The distal member 10 is obtained by forming the tapered surface as described above. It is preferable to form each tapered surface after fixing the linear member 20 to the tubular member. The method of fixing the linear member 20 to the tubular member is not particularly limited, and examples thereof include adhesive bonding, thermal bonding, and brazing. It is preferable to use a heat-shrinkable film for adhesive bonding and thermal bonding. When a heat-shrinkable film is used, it is preferable to insert a metal core material into the distal member 10 and then heat and shrink the heat-shrinkable film.

This application claims the benefit of priority under Japanese Patent Application No. 2019-019997 filed on February 6, 2019. The entire contents of the specification of Japanese Patent Application No. 2019-01997, filed on February 6, 2019, are incorporated herein by reference.

1 1st tapered part 2 2nd tapered part 3 3rd tapered part 4 Cylindrical part 5 Non-reinforcing part 10 Distal member 11 Inner layer 12 Outer layer 13 Reinforcing layer 14 Radiation opaque marker 20 Linear member 21 Gripping member 30 Extension catheter 40 Cylindrical catheter S1 1st tapered surface S2 2nd tapered surface S3 3rd tapered surface S10 Outer side surface A1 Distal end of 1st tapered part B1 Proximal end of 1st tapered part B2 Proximal end of 2nd tapered part B13 Reinforcement Proximal end of layer C Central axis of tubular part F1 Point farthest from the central axis of the tubular part of the first tapered surface N1 Point closest to the central axis of the tubular part of the first tapered surface F2 Second tapered surface The point farthest from the central axis of the tubular part N2 The point closest to the central axis of the tubular part of the second tapered surface X Axial direction of the tubular part A30 Distal end of the extension catheter A40 Distal end of the tubular part B40 Tube Proximal end of the tubular catheter a30 Distal opening of the extension catheter a40 Distal opening of the tubular catheter b40 Proximal opening of the tubular catheter

Claims (7)

An extension catheter that can be inserted into a tubular catheter and protrudes from the distal opening of the tubular catheter.
A tubular portion, a first tapered portion located proximal to the tubular portion, and a second tapered portion located proximal to the first tapered portion are provided.
The first tapered portion has an outer surface and a first tapered surface.
The second tapered portion has an outer surface and a second tapered surface.
An extension catheter characterized by satisfying the following formulas (1) and (2).
90 ° ≤ θ ₁ ≤ 145 ° ・ ・ ・ (1)
120 ° ≤ θ ₂ ≤ 175 ° ・ ・ ・ (2)
[In the equation, θ ₁ indicates an angle formed by the first tapered surface and the axial direction of the tubular portion. θ ₂ indicates the angle formed by the second tapered surface and the axial direction. ] The extension catheter according to claim 1, which satisfies the following formula (3).
θ ₁ <θ ₂ ... (3)
[In the equation, θ ₁ and θ ₂ have the same meaning as before. ] The extension catheter according to claim 1 or 2, which satisfies the following formula (4).
T ≤ H ₁ ≤ H ₂ ... (4)
[In the formula, T indicates the thickness (mm) of the tubular portion at the distal end of the first tapered portion. H ₁ shows the tubular portion central axis point closest to the point farthest in the radial direction of the length of the first tapered surface (mm). H ₂ indicates the radial length (mm) of the point closest to the central axis and the point farthest from the central axis of the tubular portion of the second tapered surface. ] The extension catheter according to any one of claims 1 to 3, which satisfies the following formula (5).
0.3D ≤ D ₂ ... (5)
[In the formula, D indicates the outer diameter (mm) of the tubular portion at the distal end of the first tapered portion. D ₂ indicates the radial length at the proximal end of the second tapered portion. ] Further, a third tapered portion located proximal to the second tapered portion is provided.
The third tapered portion has an outer surface and a third tapered surface.
The extension catheter according to any one of claims 1 to 4, which satisfies the following formula (6).
-5 ° ≤ θ ₃ ≤ 5 ° ... (6)
[In the equation, θ ₃ indicates the angle formed by the third tapered surface and the axial direction. ] A reinforcing layer is provided on the cylindrical portion, and the reinforcing layer is provided.
The extension catheter according to any one of claims 1 to 5, which satisfies the following formula (7).
D ≤ L ₄ ≤ 3D ... (7)
[In the formula, D indicates the outer diameter (mm) of the tubular portion at the distal end of the first tapered portion. L ₄ is a show from the proximal end of the axial to the distal end of the first tapered portion length (mm) of the reinforcing layer. ] A step of making a notch in the tubular member to form a first tapered surface, and a step of making a notch from the proximal side to the distal side of the first tapered surface to form a second tapered surface.
A method for manufacturing an extension catheter, which comprises.

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