WO2016158584A1

WO2016158584A1 - Dilation catheter and method for manufacturing dilation catheter

Info

Publication number: WO2016158584A1
Application number: PCT/JP2016/059053
Authority: WO
Inventors: 賢一雲山; 雅貴小野
Original assignee: テルモ株式会社
Priority date: 2015-03-27
Filing date: 2016-03-22
Publication date: 2016-10-06
Also published as: JPWO2016158584A1

Abstract

[Problem] To provide a dilation catheter including a dilating part with enhanced passage properties, dilatability, and abrasion resistance, and also provide a method for manufacturing said dilation catheter. [Solution] A dilation catheter 100 includes a dilating part 200 that is constituted from a first dilation body 210 and a second dilation body 220 disposed so as to cover the first dilation body. The second dilation body is constituted from a more flexible material than the first dilation body. The first dilation body is constituted from a material having higher pressure resistance than the second dilation body, and is formed such that the slope of the compliance curve thereof is greater than the slope of the compliance curve of the second dilation body.

Description

Dilatation catheter and dilatation catheter manufacturing method

The present invention relates to a dilatation catheter that is a medical device and a method for producing the dilatation catheter.

2. Description of the Related Art In the medical field, catheter devices that are used to expand a lesion (stenosis) formed in a living body lumen, place a stent in the lesion, and the like are widely known (for example, the following patent documents) 1 and 2).

The balloon (expansion portion) provided in the catheter device as described above is required to satisfy both the passage of the lesion and the expandability when the lesion is expanded. For example, if the lesion is calcified and the symptom has progressed to a state close to complete obstruction, in order to pass the balloon through the lesion, reduce the diameter of the balloon as much as possible. While it is required to have a high passability, after passing through the lesion, it must have sufficient expandability to allow the calcified lesion to be expanded. It is done.

JP 2012-20077 A JP 2012-5705 A

Usually, a method of reducing the thickness of the balloon is generally adopted as a measure for improving the passage of the balloon. However, if the balloon wall thickness is reduced, the balloon's scratch resistance (rubbing strength) is lowered, so that the expansion function of the balloon may be lowered when passing through a calcified lesion or the like. In other words, when the passage is improved by reducing the thickness of the balloon, even if the balloon can pass through the lesion, the expansion force acting on the lesion can be reduced.

For example, if the balloon thickness is increased in order to suppress a decrease in scratch resistance, naturally, the passage property will decrease, and if the balloon is formed of a flexible material, the balloon expandability will decrease. It will be. For this reason, it becomes difficult to achieve the initial purpose of providing a balloon catheter having passability and expandability that can be used for treatment of a calcified lesion.

The present invention has been made in view of the above problems, and provides a dilatation catheter including an dilatation portion that is improved in scratch resistance as well as passability and expansibility, and a method for manufacturing the dilatation catheter. For the purpose.

The dilatation catheter according to the present invention is a long shaft having flexibility that can be inserted into a living body lumen, and is fixed to a distal end portion of the shaft, and is used for supply and discharge of a pressurized medium via the shaft. And an expansion section composed of a first expansion body and a second expansion body configured to be capable of expansion deformation and contraction deformation, and the second expansion body is disposed so as to cover an outer surface of the first expansion body. And the first expansion body is made of a material having higher pressure resistance than the second expansion body, and the pressurizing medium. The slope of the compliance curve indicating the continuous change in the outer diameter of the first expansion body per unit increase amount of the internal pressure of the expansion portion accompanying the supply of the continuation of the outer diameter when the second expansion body expands The slope of the compliance curve Made is larger than a dilatation catheter.

According to the dilatation catheter according to the present invention, the dilatation portion has improved scratch resistance due to the flexibility of the second dilation body covering the first dilation body, and the extensibility due to the pressure resistance of the first dilation body. Will be improved. Furthermore, since the slope of the compliance curve of the first expansion body is formed larger than the slope of the compliance curve of the second expansion body, the amount of expansion deformation of the first expansion body when the internal pressure of the expansion portion increases is It restrict | limits according to the expansion diameter of a 2nd expansion body. Therefore, even when the expanded portion is configured to have a reduced diameter by reducing the thickness of the first expanded body and the thickness of the second expanded body, the expansion force that causes the entire expanded portion to act on the lesioned portion. It becomes possible to increase to a desired size. Therefore, it is possible to provide an dilatation catheter including an dilation portion that is improved in scratch resistance as well as passability and expandability.

It is a figure which shows the dilatation catheter which concerns on embodiment, (A) is a figure which simplifies and shows the whole structure of an dilatation catheter, (B) is an expanded sectional view which shows the front end side of an dilatation catheter. It is a figure for demonstrating the structure of the expansion part with which the dilatation catheter which concerns on embodiment is equipped, Comprising: (A) is a fragmentary sectional view which expands and shows the expansion part in the contracted state, (B) is the expanded state It is a fragmentary sectional view which expands and shows the expansion part in FIG. It is a fragmentary sectional view which expands and shows 3A part shown to FIG. 2 (A). It is a figure which shows the relationship between the change of the outer diameter of an expansion part, a 1st expansion body, and a 2nd expansion body, and the change of the internal pressure of an expansion part. FIG. 9 is a diagram showing a modification of the second expansion body, where (A) is a perspective view showing a part of the second expansion body in an enlarged manner, and (B) is a line 5A-5A shown in FIG. 5 (A). It is an axial orthogonal cross section of the 2nd expansion body in alignment with.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

FIG. 1 is a diagram illustrating an overall configuration of an dilatation catheter according to the embodiment, FIGS. 2 and 3 are diagrams for explaining dilation portions (first dilation body and second dilation body) included in the dilatation catheter, and FIG. It is a figure which shows the relationship between the change of the outer diameter of an expansion part, a 1st expansion body, and a 2nd expansion body, and the change of the internal pressure of an expansion part.

With reference to FIGS. 1 (A) and 1 (B), the dilatation catheter 100 according to the present embodiment has a long shaft 120 inserted through a living organ, and an dilation portion 200 disposed on the distal end side of the shaft 120. It is configured as a catheter device for expanding and treating the lesion by expanding the lesion at the lesion (stenosis). However, the dilatation catheter 100 can also be configured as a stent placement catheter device that is used to place a balloon-expandable stent (BX-type stent) in the lesion after the lesion is expanded, for example. .

In addition, the dilatation catheter 100 according to the present embodiment is configured as a PTCA dilatation catheter used to push and spread a lesion formed in the coronary artery. For example, other blood vessels, bile ducts, trachea, esophagus, In addition, it can be configured to be used for the purpose of treatment and improvement of a lesion (stenosis) formed in a living organ such as the digestive tract, urethra, ear-nose lumen, and other organs.

First, the overall configuration of the dilatation catheter 100 will be described.

As shown in FIGS. 1A and 1B, the dilatation catheter 100 is fixed to a long shaft 120 having flexibility that can be inserted into a living body lumen, and a distal end portion of the shaft 120. In addition, an expansion portion 200 including a first expansion body 210 and a second expansion body 220 and a hub 150 disposed on the base end side of the shaft 120 are provided. In the description of the dilatation catheter 100, the side on which the dilation portion 200 is provided is referred to as the distal end side, the side on which the hub 150 is provided is referred to as the proximal end side, and the extending direction of the shaft 120 is referred to as the axial direction.

The dilatation catheter 100 is a so-called rapid exchange type in which an opening 135 through which the guide wire 180 is led out is provided near the distal end side of the shaft 120. However, the dilatation catheter 100 can also be configured as a so-called over-the-wire type catheter device in which the guide wire lumen 131 extends from the distal end of the shaft 120 to the proximal end.

As shown in FIG. 1B, the shaft 120 has a pressurized medium between the inner tube (inner tube shaft) 130 in which the guide wire lumen 131 into which the guide wire 180 is inserted and the inner tube 130. An outer tube (outer tube shaft) 140 that forms a flowable pressurized medium lumen 141 is formed.

The shaft 120 has a double tube structure in which the inner tube 130 is inserted into the outer tube 140 and the inner tube 130 and the outer tube 140 are concentrically positioned.

As shown in FIG. 1 (B), a tip tip 240 made of a member different from the inner tube 130 is fixed to the tip of the inner tube 130. The guide wire lumen 131 extends into the shaft 120 so as to communicate with two openings, a distal end opening 243 formed at the distal end of the distal end tip 240 and a proximal end opening 135 formed at the proximal end of the inner tube 130. Exist.

The distal tip 240 attached to the distal end of the inner tube 130 has a function of preventing the living organ from being damaged when the distal end of the dilatation catheter 100 comes into contact with the living organ (such as the inner wall of the blood vessel). The distal tip 240 can be constituted by a tubular member that is more flexible than the inner tube 130, for example. Further, the distal tip 240 can be formed in a tapered shape in which the outer diameter gradually decreases toward the distal end side as illustrated in consideration of the insertion property into the biological lumen and the mobility in the biological lumen. It is. However, the installation of the tip tip 240 can be omitted as appropriate.

The inner tube 130 is configured by a hollow tube material whose proximal end is curved radially outward. Near the distal end of the inner tube 130 and the proximal end of the distal tip 240, the distal end portion 211 of the first expansion body 210 provided in the expansion portion 200 is joined in a liquid-tight and air-tight manner by a known method such as welding (FIG. 2 (B)).

In the vicinity of the proximal end of the inner tube 130, a connection opening 145 formed at a predetermined position of the outer tube 140 is joined in a liquid-tight and air-tight manner. The guide wire 180 has a guide wire lumen 131 with the distal end opening 243 of the distal end tip 240 provided at the distal end of the inner tube 130 and the proximal end opening 135 provided at the proximal end of the inner tube 130 as inlets or outlets, respectively. Is inserted.

Examples of the material constituting the inner tube 130 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, thermoplastic resins such as soft polyvinyl chloride, silicone rubber, latex rubber, etc. These various rubbers, various elastomers such as polyurethane elastomer, polyamide elastomer and polyester elastomer, and crystalline plastics such as polyamide, crystalline polyethylene and crystalline polypropylene can be used. In these materials, for example, an antithrombotic substance such as heparin, prostaglandin, urokinase, arginine derivative or the like can be blended to obtain a material having antithrombotic properties.

The outer tube 140 is formed of a hollow tube material extending from the vicinity of the base end portion of the expansion portion 200 (the base end portion 213 of the first expansion body 210 and the base end portion 213 of the second expansion body 220) to the hub 150. ing. In the vicinity of the distal end of the outer tube 140, a base end portion 213 of the first expansion body 210 provided in the expansion portion 200 is joined in a liquid-tight and air-tight manner by a known method such as welding (see FIG. 2B). .

As a constituent material of the outer tube 140, for example, the same material as that of the inner tube 130 can be used. It is also possible to coat a substance having antithrombogenicity on a portion of the outer tube 140 that comes into contact with blood (for example, the outer surface of the outer tube 140).

As shown in FIG. 1A, the hub 150 includes a connecting portion 151 that can be connected in a liquid-tight and air-tight manner to a supply device (not shown) such as an indeflator for supplying a pressurized medium. The connecting portion 151 of the hub 150 can be configured by, for example, a known luer taper configured such that a fluid tube or the like can be connected / separated.

The pressurized medium (for example, physiological saline, contrast medium, etc.) used for the expansion of the expansion part 200 can be caused to flow into the shaft 120 via the connection part 151 of the hub 150. The pressurized medium is supplied to the internal space 207 of the expansion unit 200 via the pressurized medium lumen 141. The internal space 207 of the expansion part 200 is a space part that is defined between the inner surface of the first expansion body 210 provided in the expansion part 200 and the outer surface of the inner tube 130 (see FIG. 2B). ).

Next, the expansion part 200 provided in the dilatation catheter 100 will be described.

As shown in FIGS. 2A and 2B, the expansion part 200 includes a first expansion body 210 disposed inside the expansion part 200 (near the inner tube 130), and an outer surface of the first expansion body 210. And the second expansion body 220 arranged so as to cover. That is, the expansion part 200 has a two-layer structure including a first expansion body 210 forming an inner layer and a second expansion body 220 forming an outer layer.

Each of the first expansion body 210 and the second expansion body 220 is configured to be capable of expansion deformation and contraction deformation as the pressurized medium flows into and out of the internal space 207 of the expansion portion 200. The expanded portion 200 is a portion having a function of expanding the lesioned portion or the like as a whole by combining the first expanded body 210 and the second expanded body 220, that is, a portion having the same function as a balloon in a conventionally known balloon catheter. It is configured as.

In the dilatation catheter 100 according to the present embodiment, the first dilation body 210 and the second dilation body 220 have different functions by providing the first dilation body 210 and the second dilation body 220 with different physical properties. I have it. Specifically, the first expansion body 210 mainly plays a role of increasing the expansion force applied when the expansion section 200 spreads the lesioned area, and the second expansion body 220 mainly functions as the expansion section 200. It plays the role of improving the scratch resistance and adjusting the outer diameter (expansion deformation amount) of the expanded portion 200 during expansion.

The first expansion body 210 is made of a material having a higher pressure resistance than the second expansion body 220 (a material having a high pressure property). As a constituent material of the first expansion body 210, for example, polyamide, PET, or the like can be used. The constituent material of the first expansion body 210 is preferably polyamide.

Examples of the polyamide include polytetramethylene adipamide (nylon 46), polycaprolactam (nylon 6), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), polyhexamethylene Homopolymers such as dodecanamide (nylon 612), polyundecanolactam (nylon 11), polydodecanolactam (nylon 12), caprolactam / lauryl lactam copolymer (nylon 6/12), caprolactam / aminoundecanoic acid co Copolymers (nylon 6/11), caprolactam / ω-aminononanoic acid copolymer (nylon 6/9), caprolactam / hexamethylene diammonium adipate copolymer (nylon 6/66), adipic acid and Meta-xylene Copolymers of, or hexamethylene diamine and m, and aromatic polyamides such as a copolymer of p- phthalic acid.

It is also possible to use a polyamide elastomer which is a block copolymer having nylon 6, nylon 66, nylon 11, nylon 12 or the like as a hard segment and polyalkylene glycol, polyether or aliphatic polyester as a soft segment. is there. Moreover, the said polyamide may be used individually by 1 type, and may use 2 or more types together.

The second expansion body 220 is made of a material that is more flexible than the first expansion body 210. As a constituent material of the second expansion body 220, for example, a polyester elastomer, a polyamide elastomer, a polyolefin (for example, polyethylene, polypropylene), a polymer material such as polyvinyl chloride, a fluororesin, silicon, urethane, or a mixture thereof, or the above Two or more polymer materials can be used. In addition, as a constituent material of the 2nd expansion body 220, elastomer materials, such as a polyester elastomer and a polyamide elastomer, are preferable, and a polyamide elastomer is especially preferable.

Further, in the dilatation catheter 100 according to the present embodiment, the first dilation body 210 is formed with a larger slope of the compliance curve than the second dilation body 220. With reference to FIG. 4, a compliance curve and its inclination will be described.

In FIG. 4, the change of the internal pressure of the expansion part 200, the change of the outer diameter of the first expansion body 210 (solid line A in the figure), the change of the outer diameter of the second expansion body 220 (dashed line B in the figure), And the relationship with the change (two-dot chain line C in a figure) of the outer diameter of the expansion part 200 is shown in illustration.

Curve A shows a continuous change in the outer diameter of the first expansion body 210 per unit increase amount of the internal pressure (expansion deformation) when the pressurized medium is supplied to the expansion section 200 and the internal pressure of the expansion section 200 increases. The compliance curve (compliance curve) showing the amount) is shown. Curve B shows a continuous change in the outer diameter of the second expansion body 220 per unit increase amount of the internal pressure when the pressurized medium is supplied to the expansion unit 200 and the internal pressure of the expansion unit 200 increases. The compliance curve shown is shown.

The slope of the compliance curve is the ratio of the amount of expansion deformation when the same pressure is applied. The larger the slope of the compliance curve, the lower the slope of the compliance curve. This also means that the amount of expansion deformation increases in the state where the same pressure is applied. Further, the compliance value indicating the physical properties of each

expansion body

210, 220 is the pressure (internal pressure) applied to the expansion portion 200 when the absolute value of the outer diameter of each

expansion body

210, 220 is expanded to the outer diameter. The value obtained by dividing by the absolute value of.

In this embodiment, as shown in FIG. 4, the slope of the compliance curve A of the first expansion body 210 is the compliance curve of the second expansion body 210 after the internal pressure of the expansion section 200 reaches a predetermined value Ps. It is set to be larger than the slope of B. On the other hand, the inclination of the compliance curve A of the first expansion body 210 and the inclination of the compliance curve B of the second expansion body 210 of the second expansion body 220 are substantially the same until the internal pressure of the expansion portion 200 reaches a predetermined value Ps. It is set to become.

The above-mentioned “predetermined value Ps” can be set to a pressure at a timing when the application of the expansion pressure from the expansion unit 200 to the lesioned part is started in performing various procedures using the expansion catheter 100, for example. For example, it is possible to set 1 to 20 atm.

As described above, each of the

expansion bodies

210 and 220 is made of a material having different physical properties, and defines the magnitude relationship between the slopes of the compliance curves of the

expansion bodies

210 and 220. 200 has the following performance.

As shown in FIG. 2A, in a state where the expansion portion 200 is contracted (a state where the expansion portion 200 is folded around the inner tube 130), the second expansion body 220 having higher flexibility than the first expansion body 210 is in the radial direction. By deforming so as to be crushed toward the inner side (inner tube 130 side), the entire extended portion 200 is in close contact with the inner tube 130. For this reason, the outer diameter of the expanded portion 200 at the time of contraction is reduced, and the permeability to the lesioned portion is improved.

In addition, since the second expansion body 220 forming the outer layer functions as a flexible layer that protects the first expansion body 210, the scratch resistance of the expansion portion 200 is improved. Therefore, even when the lesion is calcified and the symptom has progressed to a state close to complete occlusion, the entire expanded portion 200 can be suitably protected when passing through the lesion.

When the expansion part 200 is expanded and deformed after the expansion part 200 has passed through the lesion, the first expansion body 210 and the second expansion body 220 expand according to the compliance curve shown in FIG. Specifically, until the internal pressure of the expansion unit 200 reaches a predetermined pressure Ps, the

expansion bodies

210 and 220 expand so that the slopes of the compliance curves A and B become substantially the same, After the internal pressure reaches the predetermined pressure Ps, the

expansion bodies

210 and 220 are arranged such that the slope of the compliance curve A of the first expansion body 210 is larger than the slope of the compliance curve B of the second expansion body 220. Expands.

After the internal pressure of the expansion part 200 reaches the predetermined pressure Ps, the expansion deformation of the first expansion body 210 is limited according to the outer diameter of the second expansion body 220 that covers the outer surface of the first expansion body 210. The In the present embodiment, the first expansion body 210 and the second expansion body 220 are both expanded, and a tensile force (tension) is applied to the second expansion body 220 formed more flexibly than the first expansion body 210 to some extent. Then, the expansion of the second expansion body 220 reaches the limit, and the subsequent expansion deformation of the second expansion body 220 is suppressed. At this timing, the expansion deformation of the first expansion body 210 starts to be limited (see FIG. 2B).

As a result, the slope of the compliance curve C (two-dot chain line in the figure) indicating a continuous change in the outer diameter of the entire expanded portion 200 is the slope of the compliance curve A of the first expanded body 210 and that of the second expanded body 220. It is adjusted to an intermediate value between the slopes of the compliance curve B. That is, the outer diameter of the expansion part 200 changes so as to change at an intermediate value between the outer diameter of the first expansion body 210 and the outer diameter of the second expansion body 220. Therefore, when expanding the lesioned part, it is possible to prevent the entire expanded part 200 from expanding and deforming indefinitely as the internal pressure increases, and a desired expansion force can be applied to the lesioned part. .

In the stage before the internal pressure of the expansion part 200 reaches the predetermined pressure Ps, the

expansion bodies

210 and 220 expand so that the slopes of the compliance curves A and B become substantially the same. The expansion deformation is not limited by the second expansion body 220. Therefore, before the start of applying the expansion force to the lesioned part, the entire expansion part 200 can be rapidly expanded and deformed.

In addition, as a method of setting the inclination of the compliance curve of the first expansion body 210 and the inclination of the compliance curve of the second expansion body 220 to desired values, for example, the constituent material of the first expansion body 210 and the second expansion body It is possible to perform adjustment by adjusting the material of the constituent material 220, adjusting the expansion ratio (adjusting the molecular orientation in the material) when forming the tube-shaped material (parison) constituting each

expansion body

210, 220, and the like. .

Next, each part of the expansion part 200 and the shaft 120 will be described in detail.

As shown in FIG. 3, for example, the thickness (film thickness) d1 of the first expansion body 210 before the expansion portion 200 is expanded and deformed (the expansion portion 200 is folded) is the second expansion body 220. It can be formed to be thinner than the thickness (film thickness) d2. 3 is an enlarged cross-sectional view showing a portion surrounded by a broken line portion 3A shown in FIG.

As described above, in the expansion part 200, the outer surface of the first expansion body 210 is covered with the second expansion body 220 having excellent scratch resistance. For this reason, even when the thickness d1 of the first expansion body 210 having a relatively large pressure resistance (relatively low scratch resistance) is formed thin, the first expansion is performed when the expansion portion 200 is passed through the lesion. The body 210 can be protected. Therefore, the thickness d1 of the first expansion body 210 can be formed thinner than that of the second expansion body 220.

Further, the second expansion body 220 is to add scratch resistance to the expansion portion 200, that is, to prevent the occurrence of trauma due to a load applied from the outside of the expansion portion 200. Therefore, it is not necessary to set the wall thickness d2 excessively large. Therefore, in this embodiment, the thickness d3 of the expansion portion 200, which is the sum of the thickness d1 of the first expansion body 210 and the thickness d2 of the second expansion body 220, is the balloon of a conventionally known general balloon catheter. It is possible to design smaller than the above. Of course, even when the wall thickness d3 of the extended portion 200 is designed to be small, desired scratch resistance can be maintained. In addition, the internal space 207 of the expansion part 200 does not communicate with the space formed between the outer surface of the first expansion body 210 and the inner surface of the second expansion body 220. For this reason, the expansion unit 200 according to the present invention allows the second expansion body 220 to expand due to the expansion of the first expansion body 210 even when a trauma or the like occurs due to a load applied from the outside of the expansion unit 200. Can be extended.

When the dilatation catheter 100 is configured as a PTCA dilatation catheter (particularly, when a calcified lesion in a state close to complete occlusion is used as a treatment target), the wall thickness d1 of the first dilator 210 is: For example, the thickness d2 of the second expansion body 220 can be formed to be 2 to 9 μm, for example, and the total of the first expansion body 210 and the second expansion body 220 can be formed. The wall thickness (thickness of the extended portion 200) d3 can be formed to 3 to 10 μm, for example. The wall thickness d1 of the first expansion body 210 is preferably configured to be thinner than the wall thickness d2 of the second expansion body 220.

Further, when the dilatation catheter 100 is configured as a catheter device for stent placement, the thickness d1 of the first dilation body 210 can be formed, for example, to 1 to 28 μm, and the wall thickness d2 of the second dilation body 220. Can be formed to, for example, 2 to 29 μm, and the total thickness (thickness of the expanded portion 200) d3 of the first extension body 210 and the second extension body 220 is, for example, 3 to 30 μm. Can do. The wall thickness d1 of the first expansion body 210 is preferably configured to be thinner than the wall thickness d2 of the second expansion body 220.

The dimensions of the thickness d1 of the first expansion body 210, the thickness d2 of the second expansion body 220, and the thickness d3 of the expansion section 200 are examples, and the thickness of each section is limited to these values. Absent.

As shown in FIG. 2B, in the first expansion body 210 provided in the expansion section 200, the distal end portion 211 is fixed to the distal end portion of the inner tube 130 and the distal end tip 240, and the proximal end portion 213 is the outer tube 140. It is fixed to the tip of the. A distal end side taper portion 211a is formed on the proximal end side of the distal end portion 211 so that the outer diameter increases toward the proximal end side. The distal end side of the proximal end portion 213 is directed toward the distal end side. Thus, a proximal side taper portion 213a that changes so as to increase the outer diameter is formed. A straight portion 215 extending in a substantially linear shape is formed between the distal end side tapered portion 211a and the proximal end side tapered portion 213a.

As shown in FIG. 2B, in the second expansion body 220 provided in the expansion portion 200, the distal end portion 221 is fixed to the outer surface of the distal end portion 211 of the first expansion body 210, and the base end portion 223 is the first expansion end. It is fixed to the outer surface of the base end portion 213 of the one expansion body 210. Further, a distal end side taper portion 221a that changes so that the outer diameter increases toward the proximal end side is formed on the proximal end side of the distal end portion 221, and the distal end side of the proximal end portion 223 has a distal end side. A proximal-side tapered portion 223a that changes so as to increase the outer diameter toward is formed. A straight portion 225 extending substantially linearly is formed between the distal end side tapered portion 221a and the proximal end side tapered portion 223a.

As shown in FIG. 2B, the distal end surface of the first expansion body 210 and the distal end surface of the second expansion body 220 have a tapered shape that tapers toward the distal end side in order to improve the passage to the lesioned part. It is possible to form. However, the shape of the tip surface of each

expansion body

210, 220 is not limited to the tapered shape as shown in the figure.

The second expansion body 220 is not limited to the shape of FIG. 2B as long as it covers the outer surface of the first expansion body 210, and the distal end portion 221 is more distal than the distal end portion 211 of the first expansion body 210. It may be disposed on the side and fixed to the distal end portion of the inner tube 130 and the distal end tip 240. Further, the base end portion 223 of the second expansion body 220 may be disposed on the base end side with respect to the base end portion 213 of the first expansion body 210 and may be fixed to the outer tube 140.

At the time of manufacturing the dilatation catheter 100, a substantially cylindrical tube-shaped material (parison) constituting the first expansion body 210 and a substantially cylindrical tube-shaped material (parison) constituting the second expansion body 220 are prepared. Each of these materials is the same as that used in the manufacture of a balloon provided in a general balloon catheter, for example, using a predetermined molding die (balloon molding die or the like) as the constituent material of each

expansion body

210, 220. And can be obtained by molding. The first expansion body 210 is fixed to the shaft 120, and the second expansion body 220 disposed so as to cover the outer surface of the first expansion body 210 is fixed to the first expansion body 210, thereby the shaft 120. It is possible to provide the extension part 200 in the.

In the expansion portion 200, the portion where the straight portion 215 of the first expansion body 210 and the straight portion 225 of the second expansion body 220 overlap in the axial direction is an effective expansion portion (pressurizing portion) that applies expansion force to the lesioned portion. ) 205 is configured.

As shown in FIG. 2B, the inner tube 130 included in the shaft 120 has a position X at which the central portion P1 of the expansion portion 200 (the central portion of the expansion effective portion 205) is projected in the axial direction of the shaft 120. A line contrast marker 160 is provided. Further, the X-ray contrast marker 160 has both

end portions

161 and 163 in the axial direction of the shaft 120 each having a tapered shape in which the outer diameter gradually decreases toward the distal end side and the proximal end side.

By providing the X-ray contrast marker 160, when performing a procedure using the dilatation catheter 100, it becomes possible to easily confirm the central portion P1 of the dilation portion 200 on the X-ray image, so that the procedure can be performed quickly. It becomes possible to do. Further, the distal end portion 161 of the X-ray contrast marker 160 is formed in a tapered shape whose outer diameter gradually decreases toward the distal end side, and the proximal end portion 163 of the X-ray contrast marker 160 is outwardly directed toward the proximal end side. Since the diameter gradually decreases, the first expansion body 210 can be protected from rubbing between the first expansion body 210 and the X-ray contrast marker 160 when the expansion section 200 is passed through the lesion. It becomes possible.

In the dilatation catheter 100 according to the present embodiment, the first dilator 210 may be made of a material having a relatively small scratch resistance and may be formed with a small thickness. In addition, when the expansion portion 200 contracts, the first expansion body 210 is in close contact with the inner tube 130 as the relatively flexible second expansion body 220 contracts. For this reason, when the expansion part 200 is passed through the lesioned part, the first expansion body 210 may be rubbed by being caught on both

end parts

161 and 163 of the X-ray contrast marker 160. Therefore, by forming both

end portions

161 and 163 of the X-ray contrast marker 160 in a smooth tapered shape, it is possible to protect against such rubbing. Furthermore, the passability of the X-ray contrast marker 160 to the lesioned part can be improved.

The X-ray contrast marker 160 is, for example, a ring-shaped member having X-ray contrast properties that is processed into a tapered shape by fitting and fixing the inner tube 130, or a ring-shaped member having X-ray contrast properties. It is possible to provide by combining and fixing the member and another member constituting the tapered portion into the inner tube 130 so as to be integrated. In addition, as a constituent material of the X-ray contrast marker 160, what was comprised with metals, such as platinum, gold | metal | money, silver, titanium, tungsten, these alloys, etc. can be used, for example.

A hydrophilic coat layer (surface lubrication layer) is formed on the outer surface of the second extension body 220 provided in the extension portion 200. Since the hydrophilic coat layer is provided on the outer surface of the second expansion body 220, when the expansion section 200 is moved in the living body lumen or passed through the lesioned portion, the space between the second expansion body 220 and each section is determined. The frictional resistance is reduced. As described above, the second expansion body 220 is made of a relatively flexible material in order to improve the scratch resistance of the expansion portion 200, and the frictional resistance tends to increase accordingly. By forming a hydrophilic coat layer on the outer surface of the second expanded body 220, the frictional resistance to the lesioned part is reduced while maintaining the scratch resistance, and the passage to the lesioned part is further improved. Become.

For example, the hydrophilic coat layer is formed by applying a solvent constituting the hydrophilic coat layer (a solvent containing a hydrophilic polymer) to the outer surface of the second extended body 220 and then applying hydrophilicity to the outer surface of the second extended body 220. It can be formed by crosslinking a polymer. As the solvent, for example, DMF, chloroform, acetone, THF, dioxane, benzene and the like can be used. These may be used alone or in combination of two or more. Moreover, as a method of bridge | crosslinking, it can carry out by heat processing and / or electron beam irradiation, for example.

Next, the manufacturing procedure of the dilatation catheter 100 will be described.

First, the first expansion body 210 is prepared (first preparation step). In the first preparation step, for example, a tube-shaped material constituting the first expansion body 210 is purchased and prepared, or the tube-shaped material is molded using a molding die to obtain the first expansion body 210.

Next, the second expansion body 220 is prepared (second preparation step). In the second preparation step, as in the first preparation step, for example, the tube-shaped material constituting the second expansion body 220 is purchased and prepared, or the tube-shaped material is formed using a forming die. A second expansion body 220 is obtained. In addition, a 1st preparatory process and a 2nd preparatory process are random, and you may replace process order. The first preparation process and the second preparation process are collectively referred to as a preparation process.

Next, the first expansion body 210 is fixed to the shaft 120 to form a shaft assembly (shaft assembly forming step). The shaft 120 can be prepared in advance in a state where the inner tube 130, the outer tube 140, and the hub 150 are assembled prior to performing the work of fixing the first expansion body 210. The shaft assembly is a work product (intermediate product) in a state where the first expansion body 210 is fixed to the shaft 120 for convenience.

The first expansion body 210 can be fixed to the shaft 120 by a known method such as welding or fusion.

Next, a hydrophilic polymer solvent is applied to the outer surface of the second expansion body 220 (application process). Thereafter, the second expansion body 220 is subjected to heat treatment and / or electron beam treatment to crosslink the hydrophilic polymer to form a hydrophilic coat layer (coat layer forming step). In addition, you may perform an application | coating process and a coating layer formation process before a shaft assembly formation process.

After forming a hydrophilic coat layer on the outer surface of the second expansion body 220, the second expansion body 220 is fixed to the shaft assembly so as to cover the first expansion body 210 fixed to the shaft 120. For example, the second expansion body 220 may be directly fixed to the shaft 120, or may be fixed to the first expansion body 210 as shown in FIG. The second expansion body 220 can be fixed to the shaft assembly by a known method such as welding or fusion.

In general, when a hydrophilic coat layer is formed by applying a thermal load to a material having a relatively high pressure resistance such as the first expansion body 210 and having a thin wall thickness, Under the influence of heat, deformation such as thermosetting can easily occur in the material of the first expansion body 210 itself. For this reason, it becomes difficult to crosslink the hydrophilic polymer and firmly fix the hydrophilic coat layer to the outer surface of the first expansion body 210. On the other hand, in the method for manufacturing the dilatation catheter 100 according to the present embodiment, the outer surface of the second dilator 220 that is relatively less likely to be deformed than the first dilator 210 when a thermal load is applied. On the other hand, the hydrophilic polymer is crosslinked by heat treatment or electron beam treatment. For this reason, the hydrophilic coat layer can be firmly fixed to the outer surface of the second expansion body 220. Furthermore, before the first expansion body 210 and the second expansion body 220 are fixed, the second expansion body 220 is subjected to a heat treatment or an electron beam process, so that the first expansion body 210 is thermally affected. Therefore, it is possible to prevent the first expansion body 210 from being undesirably deformed with the formation of the hydrophilic coat layer.

As described above, according to the dilatation catheter 100 according to this embodiment, the dilation portion 200 has improved scratch resistance due to the flexibility of the second dilation body 220 that covers the first dilation body 210, and the first dilation body. The expandability is improved by the pressure resistance of 210. Furthermore, since the slope of the compliance curve of the first expansion body 210 is larger than the slope of the compliance curve of the second expansion body 220, the expansion of the first expansion body 210 when the internal pressure of the expansion portion 200 increases. The amount of deformation is limited according to the expansion diameter of the second expansion body 220. Therefore, even when the expanded portion 200 is configured to have a reduced diameter by reducing the thickness of the first expanded body 210 and the thickness of the second expanded body 220, the entire expanded portion 200 acts on the lesion. It is possible to increase the expansion force to a desired magnitude. Therefore, it is possible to provide the dilatation catheter 100 including the dilation portion 200 in which the scratch resistance is improved as well as the passability and the expansibility.

In addition, since the thickness of the first expansion body 210 before the expansion deformation is thinner than the thickness of the second expansion body 220 before the expansion deformation, the expansion portion 200 is formed by forming the first expansion body 210 thin. The overall thickness can be reduced, and the expanded portion 200 can be configured with a further reduced diameter.

In addition, the slope of the compliance curve of the first expansion body 210 is greater than the slope of the compliance curve of the second expansion body 210 after the internal pressure of the expansion section 200 reaches a predetermined value Ps as the pressurized medium is supplied. Since the inclination of the compliance curve of the second expansion body 220 is substantially the same until the internal pressure of the expansion portion 200 reaches the predetermined value Ps, the stage before the internal pressure of the expansion portion 200 reaches the predetermined pressure Ps. In, the expansion deformation of the first expansion body 210 is not limited by the second expansion body 220, and the entire expansion portion 200 can be rapidly expanded and deformed.

Further, the shaft 120 (inner tube 130) has an X-ray contrast marker 160 that indicates a position at which the central portion P1 of the expansion part 200 is projected in the axial direction of the shaft 120. The X-ray contrast marker 160 is Since both end

portions

161 and 163 in the axial direction of 120 are formed in a tapered shape whose outer diameter gradually decreases toward the distal end side and the proximal end side, the first expansion is performed when the expanded portion 200 is passed through the lesioned portion. It becomes possible to suitably protect the first expansion body 210 from rubbing between the body 210 and the X-ray contrast marker 160.

Further, the shaft 120 and an expansion portion 200 that can be expanded and contracted and fixed to the tip portion of the shaft 120 are provided. The outer surface of the first expansion body 210 included in the expansion portion 200 is covered by the second expansion body 220. It is possible to provide a method for manufacturing the dilatation catheter 100 configured as described above. Specifically, a long shaft 120 having flexibility that can be inserted into a living body lumen, and fixed to the distal end portion of the shaft 120, and expanded as a pressurized medium is supplied and discharged through the shaft 120. And a second expansion body formed of a material more flexible than the first expansion body 210 and the first expansion body 210. 220, a shaft assembly forming step of forming the shaft assembly by fixing the first expansion body 210 to the shaft 120, and a second extension so as to cover the first expansion body 210 fixed to the shaft 120. Fixing the expansion body 220 to the shaft assembly and forming an expansion portion 200 composed of the first expansion body 210 and the second expansion body 220. The first expansion body 210 includes a second expansion body. It is made of a material having higher pressure resistance than the body 220, and shows a continuous change in the outer diameter of the first expansion body 210 per unit increase amount of the internal pressure of the expansion section 200 accompanying supply of the pressurized medium. This is a method for manufacturing the dilatation catheter 100 in which the slope of the compliance curve is formed to be larger than the slope of the compliance curve indicating a continuous change in the outer diameter when the second dilator 220 is expanded.

In addition, the hydrophilic coat layer can be firmly fixed to the outer surface of the second extension body 220, and unnecessary deformation or the like is prevented from occurring in the first extension body 210 due to the formation of the hydrophilic coat layer. It is possible to provide a method of manufacturing the dilatation catheter 100 that can be used.

<Modification example>
Next, a modified example of the second expansion body provided in the dilatation catheter 100 will be described.

FIG. 5A is an enlarged perspective view showing a part of the second expanded body 320 according to the modified example, and FIG. 5B is an axial orthogonal cross-sectional view of the second expanded body 320 according to the modified example (FIG. 5). FIG. 5A is a cross-sectional view taken along line 5A-5A in FIG.

As the second expansion body 320 disposed so as to cover the first expansion body 210, for example, as shown in this modification, a structure in which a plurality of uneven portions 325 are formed along the circumferential direction of the outer surface is used. Is possible. As described above, since the uneven portion 325 is formed on the outer surface, when the expanded portion 200 is expanded, a mechanical locking force acts on the lesion portion where the second expanded body 320 is calcified. Let me eat it. That is, since it becomes possible to add a scoring function to the expansion part 200, it becomes possible to enhance the expansion action (therapeutic effect) of the lesioned part. In addition, since the contact area between the outer surface of the second expansion body 320 and the lesioned portion when passing through the lesioned portion is reduced, it is possible to further improve the passage through the lesioned portion.

In the illustrated example, a tube-shaped material having a hexagonal axial cross section is used for the second expansion body 320. However, there are a plurality of external shapes and cross-sectional shapes of the second expansion body 320 in the circumferential direction of the outer surface. As long as the concavo-convex portion is formed, there is no particular limitation. In addition, the second expansion body 320 is formed with a lumen 323 into which the first expansion body 210 can be inserted as shown in the drawing in consideration of workability at the time of fixing to the first expansion body 210 and the like. It is possible to use.

The material of the second expansion body 320, the slope of the compliance curve, and the like can be configured in the same manner as in the first embodiment described above. In addition, the above-described hydrophilic coat layer can be provided on the outer surface of the second expansion body 320.

As described above, the dilatation catheter and the manufacturing method thereof according to the present invention have been described through the embodiment and the modification. However, the present invention is not limited to the configuration described in the embodiment and the modification, and the description of the claims It is possible to change appropriately based on the above.

This application is based on Japanese Patent Application No. 2015-067111 filed on Mar. 27, 2015, the disclosure of which is incorporated by reference in its entirety.

100 dilatation catheter,
120 shaft,
130 inner pipe,
140 outer tube,
160 X-ray contrast marker,
161 tip,
163 proximal end,
200 extensions,
205 Extended effective part,
210 first extension,
220 second extension,
320 second extension,
325 irregularities,
d1 The thickness of the first expansion body,
d2 The thickness of the second expansion body,
d3 wall thickness of the extension,
The center of the P1 extension,
Ps Predetermined value.

Claims

A long shaft having flexibility that can be inserted into a body lumen;
An extension portion formed of a first extension body and a second extension body, which is fixed to a tip portion of the shaft and configured to be capable of expansion deformation and contraction deformation in accordance with supply and discharge of a pressurized medium through the shaft. ,
The second expansion body is arranged to cover the outer surface of the first expansion body, and is made of a material that is more flexible than the first expansion body,
The first expansion body is made of a material having a higher pressure resistance than the second expansion body, and the first expansion body per unit increase amount of the internal pressure of the expansion portion accompanying the supply of the pressure medium. A dilatation catheter in which a slope of a compliance curve showing a continuous change in the outer diameter of the body is formed larger than a slope of a compliance curve showing a continuous change in the outer diameter when the second dilator expands .
2. The dilatation catheter according to claim 1, wherein a wall thickness of the first expansion body before expansion deformation is thinner than a wall thickness of the second expansion body before expansion deformation.
The slope of the compliance curve of the first expansion body becomes larger than the slope of the compliance curve of the second expansion body after the internal pressure of the expansion portion reaches a predetermined value as the pressure medium is supplied. 3. The dilatation catheter according to claim 1, wherein the internal pressure of the dilation portion is substantially the same as an inclination of a compliance curve of the second dilation body until the internal pressure of the dilation portion reaches the predetermined value.
The shaft has an X-ray contrast marker indicating a position where a central portion of the extension portion is projected in the axial direction of the shaft,
The X-ray contrast marker according to any one of claims 1 to 3, wherein both end portions in the axial direction of the shaft are formed in a tapered shape in which an outer diameter gradually decreases toward a distal end side and a proximal end side. The dilatation catheter as described.
The dilatation catheter according to any one of claims 1 to 4, wherein a plurality of irregularities are formed along the circumferential direction on the outer surface of the second dilator.
A long shaft having flexibility that can be inserted into a living body lumen, and fixed to the tip of the shaft, and can be expanded and contracted in accordance with supply and discharge of a pressurized medium through the shaft. A dilatation catheter manufacturing method comprising:
Preparing a first expansion body and a second expansion body formed of a material more flexible than the first expansion body;
A shaft assembly forming step of fixing the first expansion body to the shaft to form a shaft assembly;
A fixing step of fixing the second extension body to the shaft assembly so as to cover the first extension body fixed to the shaft, and forming the extension portion composed of the first extension body and the second extension body. And including
The first expansion body is made of a material having a higher pressure resistance than the second expansion body, and the first expansion body per unit increase amount of the internal pressure of the expansion portion accompanying the supply of the pressure medium. An expansion catheter having a slope of a compliance curve showing a continuous change in the outer diameter of the body is larger than a slope of the compliance curve showing a continuous change in the outer diameter when the second expansion body is expanded. Production method.
Before the shaft assembly forming process or the fixing process,
An application step of applying a hydrophilic polymer solvent to the outer surface of the second expansion body;
A coating layer forming step of forming a hydrophilic coating layer by crosslinking the hydrophilic polymer by subjecting the second expansion body to heat treatment and / or electron beam irradiation. Method for producing a dilatation catheter.