WO2011118366A1

WO2011118366A1 - Balloon catheter and balloon

Info

Publication number: WO2011118366A1
Application number: PCT/JP2011/055103
Authority: WO
Inventors: 克彦清水; 拓哉垣本; 直人毛利
Original assignee: テルモ株式会社
Priority date: 2010-03-26
Filing date: 2011-03-04
Publication date: 2011-09-29
Also published as: JP5497153B2; JPWO2011118366A1

Abstract

A balloon catheter and a balloon having improved operability in addition to improved pressure resistance. A balloon catheter (10) comprises: a flexible tubular body (12) through which a drive fluid can be transferred; a balloon innermost layer (112) connected to the front end of the tubular body so as to communicate therewith and capable of being inflated and deflated by the introduction and discharge of the drive fluid; and one or more balloon outer layers (110) provided with a first tapered section (113) which has a diameter reduced toward the front end of the tubular body in the axial direction thereof and also with a second tapered section (115) which has a diameter reduced toward the base end of the tubular body in the axial direction thereof, the balloon outer layers (110) being capable of being inflated and deflated by the inflation and deflation of the balloon innermost layer, the balloon outer layers (110) covering the balloon innermost layer. At least one of the balloon outer layers is provided with a weak section (117) which reduces the rigidity of at least the first tapered section out of the first and second tapered sections.

Description

Balloon catheter and balloon

The present invention relates to a balloon catheter and a balloon.

In recent years, angioplasty using a balloon catheter has become widespread in cases of intrinsic intravascular stenosis, particularly coronary artery stenosis. This treatment method is a method of expanding a stenotic part of a coronary artery by inflating a balloon of a balloon catheter inserted percutaneously, and the balloon catheter proceeds while following a complicated blood vessel, and the stenotic part is expanded. Since pressure is applied at this time, the balloon is required to have flexibility and pressure resistance.

Various proposals have been made for the realization of the flexibility and pressure resistance of the balloon. For example, in the balloon catheter described in Patent Document 1, layers formed of different polymer materials are superimposed to form a balloon. A balance between flexibility and pressure resistance is achieved.

JP 2006-204930 A

However, a balloon formed by overlapping layers is superior in pressure resistance compared to a single layer balloon having the same thickness, but is less flexible, so that the balloon catheter tip does not follow the blood vessel and is difficult to bend. At this time, the operation of the balloon catheter may be difficult.

The present invention has been made in view of such problems, and an object thereof is to provide a balloon catheter and a balloon that can improve operability in addition to pressure resistance.

In order to achieve the above object, a balloon catheter according to the present invention is connected to and communicates with a flexible tubular body capable of transferring a driving fluid and a distal end of the tubular body. A possible innermost balloon layer, a first tapered portion that is reduced in diameter toward the distal end in the axial direction of the tubular body, and a second tapered portion that is reduced in diameter toward the proximal end in the axial direction of the tubular body, And at least one balloon outer layer that covers the innermost balloon layer that can be inflated and contracted by expansion and contraction of the innermost balloon layer, and at least one of the outer balloon layers includes the first tapered portion and the second tapered layer. Among the tapered portions, at least the first tapered portion has a fragile portion that reduces rigidity.

In order to achieve the above object, a balloon of the present invention is connected to and communicated with a distal end of a flexible tubular body capable of transporting a driving fluid, and can be inflated and contracted by inflow and discharge of the driving fluid. The balloon innermost layer is provided with a first tapered portion that is reduced in diameter toward the distal end side in the axial direction of the tubular body and a second tapered portion that is reduced in diameter toward the proximal end side in the axial direction of the tubular body. And at least one balloon outer layer covering the innermost balloon layer that can be inflated and contracted by contraction, and at least one of the balloon outer layers includes the first tapered portion and the second tapered portion. At least the first tapered portion has a fragile portion that reduces rigidity.

The balloon catheter according to the present invention configured as described above is superior in pressure resistance because the innermost layer of the balloon and the outer layer of the balloon are subjected to pressure when the driving fluid flows in, and is weak in the first taper portion. Since it has a portion, the tip of the balloon catheter is flexible and easily bent, and is excellent in operability.

Further, if the fragile portion includes at least one of a hole, a dent, a groove, and a cut, the tip of the balloon catheter becomes flexible and easily bent, and the operability of the balloon catheter is improved.

Further, if at least one of the outer balloon layers has the fragile portion in the second tapered portion, flexibility can be increased and operability can be further improved.

Further, if the plurality of balloon outer layers are provided, the innermost balloon layer and the plurality of balloon outer layers are subjected to pressure when the driving fluid flows in, so that the pressure resistance can be further improved.

The balloon of the present invention configured as described above is excellent in pressure resistance because the innermost balloon layer and the outer balloon layer are subjected to pressure when the driving fluid flows in, so that the first tapered portion has a fragile portion. Therefore, the tip of the balloon catheter is flexible and easily bent, and the operability of the balloon catheter can be improved.

Further, if the fragile portion includes at least one of a hole, a dent, a groove, and a cut, the tip of the balloon catheter becomes flexible and easily bent, and the balloon catheter can be improved.

Further, if the at least one of the outer balloon layers has the fragile portion in the second tapered portion, the flexibility is increased and the operability of the balloon catheter can be further improved.

It is a schematic block diagram of the balloon catheter which concerns on embodiment. It is sectional drawing of the balloon outer layer which concerns on embodiment. 6 is a cross-sectional view of a balloon of Comparative Example 1. FIG. 6 is a cross-sectional view of a balloon of Comparative Example 2. FIG. 6 is a sectional view of a balloon outer layer of Comparative Example 2. FIG. It is a graph showing the change of the balloon diameter of a comparative example and an Example when changing a pressure. It is a side view which shows typically the time of pushing in the 1st taper part in a piece end tip flexibility test. It is a graph which shows the result of a piece end tip flexibility test. It is a side view which shows typically the time of pushing in the 1st taper part in a 3 point | piece tip flexibility test. It is a graph which shows the result of a 3 point | piece tip flexibility test. It is sectional drawing of the modification of a balloon outer layer.

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.

As outlined in FIG. 1, a balloon catheter 10 according to the embodiment is connected to an outer tube 12 (tubular body) capable of transferring a driving fluid, a balloon 11 connected to a distal end of the outer tube 12, and a proximal end of the outer tube 12. Hub 13. The balloon catheter 10 includes an inner tube 14 that passes through a lumen 120 formed in the outer tube 12 and a distal end member 15 that is provided at the distal end of the inner tube 14. The distal end is an end located on the side inserted into the blood vessel during use, and the proximal end is an end located on the side of the operator who operates the balloon catheter 10 during use.

The balloon catheter 10 is a rapid exchange type catheter in which the guide wire 17 is inserted on the distal end side of the balloon catheter 10, and the inner tube 14 is lumen-tightly or liquid-tightly from the outer peripheral surface near the center in the axial direction of the outer tube 12. The guide wire 17 is guided. The outer tube 12 and the inner tube 14 have flexibility, and are formed of, for example, various thermoplastic resins or thermosetting resins such as polyolefin resin, polyamide resin, urethane resin, and polyimide resin. The outer tube 12 is joined to the hub 13 in an airtight or liquid tight manner.

The hub 13 has a flow path 130 that communicates with the lumen 120. The flow path 130 communicates with a driving fluid supply / discharge section (not shown) such as an indeflator, a syringe, and a pump. As a result, the driving fluid is supplied to the balloon 11 through the flow path 130 and the lumen 120 or discharged from the balloon 11. That is, the flow path 130 and the lumen 120 function as a supply and discharge path for driving fluid that inflates and contracts the balloon 11. The driving fluid may be gas or liquid, and examples of the driving fluid include gases such as helium gas, CO ₂ gas, and O ₂ gas, and liquids such as physiological saline.

The tip member 15 has a spherical tip so as to help the balloon catheter 10 follow the blood vessel and not damage the blood vessel wall. The tip member 15 has a through hole 150 communicating with the inner tube 14. The inner tube 14 and the through hole 150 form a path through which the guide wire 17 passes.

The balloon 11 is connected to the distal end of the outer tube 12 and covers the innermost balloon layer 112 that is inflated and contracted by inflow and discharge of the driving fluid, and the innermost balloon layer 112 that can be inflated and contracted by the inflating and contracting of the innermost balloon layer 112. One outer balloon layer 110.

The balloon innermost layer 112 and the balloon outer layer 110 are each formed of an independent cylindrical film body, and the balloon 11 is formed in a layered manner by covering the balloon outer layer 110 with the balloon innermost layer 112. In the present embodiment, a gap is provided between the innermost balloon layer 112 and the outer balloon layer 110, but the innermost balloon layer 112 and the outer balloon layer 110 may be in close contact.

Specific examples of constituent materials of the balloon innermost layer 112 and the balloon outer layer 110 include polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate, or polyester elastomers containing the same, and olefins such as polyethylene and polypropylene. Resins or those subjected to crosslinking treatment (especially those crosslinked by electron beam irradiation), polyamide resins such as nylon 11, nylon 12, nylon 610 or the like, polyamide elastomers containing the same, polyurethane resins, ethylene-vinyl acetate Examples thereof include materials such as polymers, those obtained by subjecting them to crosslinking treatment, polymer blends containing at least one of these, and polymer alloys.

The proximal end side of the innermost balloon layer 112 is airtight or liquid tightly joined to the outer peripheral surface of the outer tube 12, and the distal end side of the innermost balloon layer 112 is airtightly or liquid tightly joined to the outer face of the distal end member 15. Yes.

As shown in FIG. 2, the balloon outer layer 110 has a first taper portion 113 that decreases in diameter toward the distal end side in the axial direction of the outer tube 12, and a second taper that decreases in diameter toward the proximal end side in the axial direction of the outer tube 12. And the straight portion 111 provided between the first taper portion 113 and the second taper portion 115. The balloon outer layer 110 has a hole 117 (fragile portion) for reducing the rigidity of the first taper portion 113 out of the first taper portion 113 and the second taper portion 115.

The first taper portion 113 and the second taper portion 115 have a hollow substantially truncated cone shape, and the straight portion 111 has a substantially cylindrical shape extending in the axial direction of the outer tube 12. The hole 117 is circular, and the balloon outer layer 110 has a plurality of holes 117 in the entire first taper portion 113.

Further, the outer balloon layer 110 has a joint portion 119A extending from the tapered portion 113 to the distal end side, and a joint portion 119B extending from the tapered portion 115 to the proximal end side. In order to improve flexibility, the hole 117 may be provided not only in the tapered portion 113 but also in the joint portion 119 </ b> A, that is, a portion on the tip side from the tapered portion 113.

The balloon outer layer 110 is bonded to the balloon innermost layer 112 or the tip member 15 at the bonding portion 119A, and is bonded to the balloon innermost layer 112 or the outer tube 12 at the bonding portion 119B. These joining is joining by an adhesive agent or joining by heat fusion, for example. However, the straight portion, the proximal end side taper portion, and the distal end side taper portion of the balloon innermost layer 112 are not bonded or fused to the straight portion 111, the taper portion 115, and the taper portion 113 of the balloon outer layer 110, and are independent. ing.

Next, the pressure resistance test and the flexibility test regarding the embodiment described above will be described.

The inventors conducted a pressure resistance test and a flexibility test on the example in which the balloon 11 was actually manufactured, and the same test was performed on two comparative examples 1 and 2 different from the example for comparison. Actually went.

As shown in FIG. 3, the balloon 21 of the comparative example 1 is the same as the balloon inner layer 112 except that the balloon outer layer 110 is omitted from the balloon 11 of the example. The balloon 21 has tapered

portions

216 and 218 and a straight portion 214 as in the balloon outer layer 110.

As shown in FIG. 4, the balloon 31 of Comparative Example 2 is substantially the same as the balloon 11, but differs from the balloon 11 in that the

tapered portions

313 and 315 do not have holes. The balloon 21 and the balloons 11 and 31 (each of the balloon

innermost layers

112 and 312 and the balloon outer layers 110 and 310) of the example and the comparative example are formed of an elastomer including nylon 12 and have substantially the same film thickness.

<Pressure resistance test>
In the pressure resistance test, the inventors measured the change in diameter of each of the

balloons

11, 21, and 31 by changing the pressure applied to the balloons. Further, the inventors increased the pressure until the

balloons

11, 21, and 31 were broken, and determined the pressure at that time (hereinafter simply referred to as the cracking pressure). The diameters of the

balloons

11, 21, and 31 are the diameters of the

straight portions

111, 214, and 311 in a cross section perpendicular to the axial direction.

As shown in FIG. 5 and Table 1, the cracking pressures of the

balloons

11, 21, and 31 are 30 atm, 26 atm, and 32 atm, respectively. The cracking pressures of the balloons 11 and 31 are higher than the cracking pressure of the balloon 21, and the double structure It was confirmed that the pressure resistance is improved.

Also, from the experimental results shown in FIG. 5, the slope of the curve connecting the plotted points is smaller in the balloons 11 and 31 than in the balloon 21. For example, the slope L of a straight line connecting the point when the balloon diameter is 3 mm and the point when the balloon diameter is increased by 10 atm from the point obtained by the following formula 1 (in formula 1, R is from when the balloon diameter is 3 mm) The balloon diameter when increased by 10 atm, and the slope L represents the average slope of the curve connecting the points plotted in Table 1. When comparing the

balloons

11, 21, and 31, the balloon 21 While the inclination L is 0.02, the balloons 11 and 31 have 0.011 and 0.012, respectively, and the inclination L is small.

This means that in the balloons 11 and 31, the change in the balloon diameter when the pressure is changed is smaller than that in the balloon 21, and a rapid increase in the balloon diameter is suppressed. , Over-expansion of blood vessels is prevented and safety is excellent.

<One-sided tip flexibility test>
As shown in FIG. 6, in the one-sided tip flexibility test, the

straight portions

111, 214, 311 are fixed, and a pusher (not shown) pushes the first

tapered portions

113, 216, 313 by a predetermined distance, At that time, a load F (indentation load F) applied by the pusher was measured. The pusher pushes in a position 2 mm away from the ends of the

straight portions

111, 214, 311 among the first

tapered portions

113, 216, 313. The moving speed of the pusher is 5 mm / min.

The present inventors have found that the

balloons

11, 21, and 31 have a distance D when the pusher pushes in (hereinafter, simply referred to as push-in distance D) is 0.5 mm and when the push-in distance D is 1.0 mm. Each was tested.

As shown in FIG. 7, in the balloon 31 without the hole 117, the pushing load F is 2.8 times that of the balloon 21 (when the pushing distance D is 0.5 mm), and 1.9 times (the pushing distance D is 1). 0.0 mm), which is a significant increase.

In contrast, in the balloon 11 having the hole 117, the pushing load F is 2.4 times that of the balloon 21 (when the pushing distance D is 0.5 mm), and 1.7 times (when the pushing distance D is 1.0 mm). Thus, an increase in the indentation load F was suppressed compared to the balloon 31. That is, it was confirmed that the tip of the balloon 11 is easily bent even with a smaller force than the balloon 31 and is excellent in flexibility.

<3-point flexible tip test>
As shown in FIG. 8, in the three-point tip flexibility test, the

balloons

11, 21, 31 are first tapered

portions

113, 216 at the center between the support bases 40, 42 arranged separately from each other. The center of the

first taper portions

113, 216, and 313 is pushed by a pusher (not shown) so that the pusher is added. A load F (indentation load F) is measured. The separation distance between the support base 40 and the support base 42 is 10 mm.

The moving speed of the pusher is 5 mm / min, and the inventors have tested each of the

balloons

11, 21, and 31 when the push distance D is 1.0 mm and when the push distance D is 1.5 mm. Carried out.

As shown in FIG. 9, in the balloon 31 having no hole 117, the pushing load F is 3.2 times that of the balloon 21 (when the pushing distance D is 1.0 mm), 2.1 times (the pushing distance D is 1). .5 mm), which is a significant increase.

On the other hand, in the balloon 11 having the hole 117, the pushing load F is 1.9 times that of the balloon 21 (when the pushing distance D is 1.0 mm) and 1.5 times (when the pushing distance D is 1.5 mm). Thus, an increase in the indentation load F was suppressed compared to the balloon 31. That is, it was confirmed that the tip of the balloon 11 is easily bent even with a smaller force than the balloon 31 and is excellent in flexibility.

The effect of the balloon 11 and the balloon catheter 10 according to this embodiment will be described.

The balloon 11 and the balloon catheter 10 according to the present embodiment are excellent in pressure resistance because the innermost balloon layer 112 and the outer balloon layer 110 overlap each other and receive pressure when the driving fluid flows in.

Further, the balloon 11 and the balloon catheter 10 according to the present embodiment have a hole 117 in the first taper portion 113 located on the distal end side, and the distal end of the balloon catheter 10 is flexible and easily bent. When the catheter 10 is inserted into the blood vessel, the tip of the balloon catheter 10 can easily follow the blood vessel, and the operability is excellent.

Unlike the present embodiment, even if the hole 117 is not provided in the first taper portion 113 and the hole 117 is provided in the straight portion 111 or the second taper portion 115, the flexibility is improved. However, in the insertion of the balloon catheter 10 into the blood vessel, once the distal end follows the blood vessel, other subsequent portions follow the distal end and proceed relatively easily in the blood vessel, making the distal end side more flexible. It is important to make it easy to follow the blood vessel, and this embodiment is compared with the case where the hole 117 is not provided in the first taper portion 113 and the hole 117 is provided in the straight portion 111 or the second taper portion 115. Excellent operability.

The present invention is not limited to the embodiment described above, and can be variously modified within the scope of the claims.

For example, the hole as the fragile portion is not limited to a circle, and may be a polygon such as a triangle or a rectangle. Note that the number, size, arrangement, and the like of these holes can be appropriately set in consideration of pressure resistance and flexibility.

In addition, the fragile portion is not limited to a hole as long as it reduces rigidity, and is not limited to a hole, but is a thin portion formed by reducing the thickness of the first taper portion such as a recess or a groove, or a notch or the like. It may be formed by partial cutting or a combination thereof.

Further, as shown in FIG. 10, in addition to the first tapered portion 513, the second tapered portion 515 has a hole 518, and in addition to this, the joint 519B has a hole 518. The invention includes. By providing the hole 518 in the second taper portion 515 (in addition to this, the joint portion 519B), the pressure resistance is reduced as compared with the above-described embodiment, but the flexibility is increased and the operability is further improved. It can be planned.

Since the straight portion greatly contributes to pressure resistance as compared with the first taper portion and the second taper portion, the first taper portion or the first taper portion and the second taper portion excluding the straight portion are weak. By providing the portion, flexibility can be improved while ensuring pressure resistance.

The present invention is not limited to the form having one balloon outer layer as described above, but includes a form having a plurality of balloon outer layers. In such a form, when the driving fluid flows in, the innermost balloon layer and the plurality of outer balloon layers are subjected to pressure, so that the pressure resistance can be further improved.

Note that the form having a plurality of balloon outer layers is not limited to all of the plurality of balloon outer layers having a fragile portion in the first taper portion, and at least one of the plurality of balloon outer layers is fragile in the first taper portion. It is sufficient to have a part. Moreover, a weak part may be provided in the 2nd taper part in addition to the 1st taper part. The number of balloon outer layers and which of the plurality of balloon outer layers is provided with the fragile portion can be appropriately set in consideration of pressure resistance and flexibility. The present invention is not limited to the rapid exchange type, but includes an over-the-wire type catheter in which a guide wire is inserted from the proximal end side to the distal end side of the catheter and a balloon applied thereto.

Furthermore, this application is based on Japanese Patent Application No. 2010-072354 filed on Mar. 26, 2010, the disclosures of which are referenced and incorporated as a whole.

10 balloon catheter,
11, 21, 31 balloon,
110, 310, 510 Balloon outer layer,
111, 214, 311, 511 Straight part,
113, 216, 313, 513 1st taper part,
115, 218, 315, 515 second taper,
117, 517, 518 holes (fragile parts),
112, 312, 512 Balloon innermost layer,
12, 52 outer tube (tubular body),
13 hub,
14 Inner pipe,
15 Tip member.

Claims

A flexible tubular body capable of transferring a driving fluid;
A balloon innermost layer which is connected to and communicated with the distal end of the tubular body, and which can be inflated and contracted by inflow and exhaust of the driving fluid;
An expansion and contraction of the innermost layer of the balloon, comprising: a first taper portion that is reduced in diameter toward the distal end side in the axial direction of the tubular body; and a second taper portion that is reduced in diameter toward the proximal end side in the axial direction of the tubular body. And at least one balloon outer layer covering the innermost balloon layer that can be inflated and deflated by
At least one of the balloon outer layers is a balloon catheter having a weakened portion that reduces rigidity at least in the first tapered portion of the first tapered portion and the second tapered portion.
The balloon catheter according to claim 1, wherein the fragile portion includes at least one of a hole, a depression, a groove, and a cut.
The balloon catheter according to claim 1 or 2, wherein the at least one of the balloon outer layers has the fragile portion in the second tapered portion.
The balloon catheter according to any one of claims 1 to 3, comprising a plurality of balloon outer layers.
A balloon innermost layer which can be connected to and communicated with a distal end of a flexible tubular body capable of transferring a driving fluid, and can be inflated and contracted by inflow and discharge of the driving fluid;
An expansion and contraction of the innermost layer of the balloon, comprising: a first taper portion that is reduced in diameter toward the distal end side in the axial direction of the tubular body; and a second taper portion that is reduced in diameter toward the proximal end side in the axial direction of the tubular body. And at least one balloon outer layer covering the innermost balloon layer that can be inflated and deflated by
At least one of the balloon outer layers is a balloon having a fragile portion that reduces rigidity in at least the first tapered portion of the first tapered portion and the second tapered portion.
The balloon according to claim 5, wherein the fragile portion includes at least one of a hole, a depression, a groove, and a cut.
The balloon according to claim 5 or 6, wherein the at least one of the balloon outer layers has the fragile portion in the second tapered portion.
The balloon according to any one of claims 5 to 7, comprising a plurality of the balloon outer layers.