TWI637757B - Balloon catheter - Google Patents

Abstract

The balloon catheter has an outer tube shaft (10), a balloon (20), an inner tube shaft (30), and a connecting tube (40); the inner tube shaft (30) has: an outer tube shaft (10) The inner layer (31) is fused, and the outer layer (32) is fused to the outer tube shaft (10), and is inserted into the inner portion of the outer tube shaft (10) to form a guide wire lumen (30L). The front end is open as a guide wire (35); the connecting pipe (40) is made of resin which can be fused to the outer tube shaft (10) and the outer layer (32) of the inner tube shaft (30). And connected to the proximal end side of the inner tube shaft (30), and a guide wire lumen (30L) is formed, which is opened as a guide wire (45).

According to the balloon catheter, at the time of its manufacture (fusion step), the reduction in the wall thickness of the inner tube shaft can be suppressed and prevented, and the stacking of the guide wires can be prevented during use (when the balloon is expanded).

Description

Balloon catheter

The present invention relates to a quick change type balloon catheter.

Conventionally, a balloon catheter having an outer tube shaft and an inner tube shaft has been known (for example, refer to Patent Document 1 and Patent Document 2).

In the quick-change type balloon catheter shown in Patent Document 1 and Patent Document 2, a balloon is attached to the distal end of the outer tube shaft, and a distal end portion of the inner tube shaft is fixed to the distal end portion of the balloon, and the proximal end of the inner tube shaft is fixed. A guide wire is formed on the side of the outer tube shaft to open. Here, a fluid for expanding the balloon is circulated in the lumen (expanded lumen) of the outer tube shaft, and a guide wire is inserted through the lumen (guidewire lumen) of the inner tube shaft.

The balloon catheter shown in Patent Document 1 and Patent Document 2 is formed by heat-melting a first tube for forming the distal end side of the outer tube shaft, and a base end side for forming the outer tube shaft. The second tube on the proximal end side of the tube and the third tube inserted into the inside of the first tube to form the inner tube shaft form a guide wire 之间 between the first tube and the second tube.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-28243

Patent Document 2: Japanese Laid-Open Patent Publication No. 2003-164528

(1) However, in the balloon catheter, when the first tube and the second tube and the third tube are thermally fused (fusion step), a part of the resin constituting the proximal end portion of the third tube is melted toward The base end side flows out, and as a result, the wall thickness of the inner tube shaft formed by the third tube is remarkably reduced (thinning).

(2) When the wall thickness of the inner tube shaft is reduced, when the balloon catheter is used (when the balloon is expanded), the inner tube shaft is crushed due to the pressure of the liquid flowing through the expansion lumen, so that the guide wire tube is used. The cavity becomes narrow and there is a problem of creating a guide wire stack. This problem is more pronounced in high pressure balloon catheters (eg, a maximum dilatation pressure (RBP) of 18 atm or more).

(3) The first tube and the second tube for forming the outer tube shaft are made of a thermoplastic resin such as PEBAX (polyether block amide).

On the other hand, the inner tube shaft is composed of a thermoplastic resin such as PEBAX (polyether block amide), and a thermoplastic resin having good lubricity such as polyethylene or a fluorine resin. It is composed of inner layers.

Here, the resin (polyethylene or fluorine-based resin) constituting the inner layer of the inner tube shaft is not melted with respect to the first tube and the second tube composed of PEBAX or the like, so that it is fused. The constituent resin of the inner layer which is melted in the step and flows out toward the proximal end side is extended from the vicinity of the opening which becomes the inner tube axis of the guide wire, and becomes a blade-like piece (burr). In order to avoid intrusion into the blood vessel during peeling of the balloon catheter, the debris (burr) must be removed after the melting step, and the operation of removing the debris (for example, the cutting operation by the razor) is extremely cumbersome.

The present invention has been created in light of the above circumstances.

A first object of the present invention is to provide a balloon catheter which can suppress and prevent a reduction in the thickness of the inner tube shaft at the time of its production (fusion step).

A second object of the present invention is to provide a balloon which can prevent the inner tube shaft from being crushed (the narrowing of the guide wire lumen) and the stacking of the guide wire accompanying it at the time of use (when the balloon is expanded) catheter.

A third object of the present invention is to provide a component of a resin which does not generate an inner layer from the inner tube shaft in the vicinity of the opening of the inner tube shaft which is a guide wire when it is manufactured (melting step). The edge of the balloon catheter.

(1) A balloon catheter according to the present invention, comprising: an outer tube shaft formed of a thermoplastic resin; and a balloon attached to a distal end of the outer tube shaft and configured to flow through the outer tube shaft Expanding by expanding the liquid in the lumen; The inner tube shaft is provided with an inner layer composed of a thermoplastic resin that cannot be fused to the outer tube shaft, and an outer layer formed of a thermoplastic resin that can be fused to the outer tube shaft, and is formed with a plug a guide wire lumen for inserting a guide wire through the inside of the outer tube shaft and the inside of the balloon, and a front end portion of the inner tube shaft is fixed to a front end portion of the balloon, so that the front end serves as a guide a lead wire is formed as an opening; and the connecting tube is formed of a thermoplastic resin that can be fused to the outer tube shaft and the outer layer of the inner tube shaft, and is connected to the proximal end side of the inner tube shaft, and The inner tube shaft forms a guide wire lumen together, and the base end serves as a guide wire to open.

(2) In the balloon catheter of the present invention, preferably, a first tube for forming a distal end side of the outer tube shaft, a base end side for forming the outer tube shaft, and a base of the first tube are disposed. a second tube on the end side, the inner tube and the outer layer, and a third tube that is inserted into the inner tube shaft to be inserted into the first tube, and a third tube for forming the connecting tube The fourth tube on the proximal end side of the third tube is formed by heat fusion.

According to the balloon catheter of the above configuration, at the time of manufacture (melting step), the fourth tube for forming the connecting tube is configured to block the third tube (the inner layer and the inner tube for forming the inner tube shaft) by blocking the flow path. The constituent resin of the outer layer is melted and flows out toward the proximal end side, and as a result, the wall thickness of the inner tube shaft can be maintained.

As a result of maintaining the wall thickness of the inner tube shaft, when the balloon catheter is used (When the balloon is expanded), there is no possibility that the inner tube shaft is crushed by the pressure of the liquid expanding the balloon, and the guide wire lumen is narrowed, so that the stacking of the guide wires does not occur.

Further, in the fusing step, since the constituent resin of the inner layer of the inner tube shaft does not flow out toward the proximal end side, the composition from the inner layer does not occur in the vicinity of the guide wire 作为 which is the opening of the connecting tube. Blade-like fragments (burrs) of resin.

(3) In the balloon catheter of the present invention, preferably, the outer tube shaft (the first tube and the second tube), the outer layer of the inner tube shaft (the third tube), and the connecting tube (the aforementioned The thermoplastic resin of the fourth tube) is at least one selected from the group consisting of polyamine, polyether polyamine, polyurethane, polyether block amide (PEBAX), and nylon, and constitutes the inner tube shaft ( The thermoplastic resin of the inner layer of the third tube) is a polyolefin or a fluorine resin.

(4) In the balloon catheter of the present invention, preferably, the outer tube shaft (the first tube and the second tube), the outer layer of the inner tube shaft (the third tube), and the connecting tube (the aforementioned The thermoplastic resin of the fourth tube) is a polyether block amide (PEBAX) or nylon, and the thermoplastic resin constituting the inner layer of the inner tube shaft (the third tube) is polyethylene.

When a polyethylene having a relatively low melting point and not thermally fused with PEBAX or nylon is used as the inner tube shaft (the third tube), the connecting tube (the fourth tube) is attached to the base of the inner tube shaft (the third tube). The end side is particularly effective.

(5) In the balloon catheter of the present invention, preferably, the aforementioned The nozzle (fourth tube) is composed of a thermoplastic resin having a hardness of 70 or more as measured by a D-type durometer.

By using a thermoplastic resin having a high hardness as a constituent material of the connecting tube (fourth tube), the rigidity as a guide wire tube axis (the effect of preventing the narrowing of the guide wire lumen) can be further enhanced.

According to the balloon catheter of the present invention, at the time of its manufacture (fusion step), the reduction in the wall thickness of the inner tube shaft can be suppressed and prevented.

Further, in the use of the balloon catheter of the present invention (when the balloon is expanded), the inner tube shaft can be prevented from being crushed (the narrowing of the guide wire lumen) and the stacking of the guide wires accompanying this.

Further, in the manufacture of the balloon catheter of the present invention (fusion step), fragments (burrs) constituting the resin from the inner layer of the inner tube shaft are not generated in the vicinity of the guide wire.

100‧‧‧ balloon catheter

10‧‧‧Outer tube shaft

10L‧‧‧Expanded lumen

20‧‧‧ balloons

30‧‧‧Inner tube shaft

30L‧‧‧ Guidewire lumen

31‧‧‧ inner layer

32‧‧‧ outer layer

35‧‧‧Guide line

40‧‧‧Connecting tube

45‧‧‧Guide line

50‧‧‧Microtubes

60‧‧‧

65‧‧‧ balloon expansion

70‧‧‧ elastic buckle

80‧‧‧core

90‧‧‧ mandrel

10A‧‧‧1st tube

10B‧‧‧2nd tube

30A‧‧‧3rd tube

31A‧‧‧ inner layer

32A‧‧‧ outer layer

40A‧‧‧4th tube

Fig. 1 is an explanatory view showing a balloon catheter according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a main part of the balloon catheter shown in Fig. 1 (partial detail view).

Fig. 3 is a partial enlarged view of Fig. 2 (Detailed view of Part III).

Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3.

Fig. 5 is a cross-sectional view showing the manufacturing process of the balloon catheter shown in Fig. 1 (arrangement of the tube axis before fusion).

Fig. 6 is a partial enlarged view of Fig. 5 (detailed view of part VI).

The balloon catheter 100 of the present embodiment shown in Figs. 1 to 4 is used in Percutaneous Transluminal Coronary Angioplasty (PTCA).

The balloon catheter 100 includes an outer tube shaft 10 made of a thermoplastic resin, and a balloon 20 attached to the distal end of the outer tube shaft 10 and circulating through the expanded lumen 10L formed in the outer tube shaft 10. The inner tube shaft 30 is provided with an inner layer 31 composed of a thermoplastic resin which cannot be fused to the outer tube shaft 10, and a thermoplastic resin which can be fused to the outer tube shaft 10 The outer layer 32 is formed, and a guide wire lumen 30L (constituting a guide wire tube axis) through which the inside of the outer tube shaft 10 and the inside of the balloon 20 are inserted and inserted into the guide wire is formed, and the inside is formed. The front end portion of the tube shaft is fixed to the front end portion of the balloon 20 such that the front end serves as a guide wire 35 to open; and the connecting tube 40 is formed by the outer layer 32 which is fused to the outer tube shaft 10 and the inner tube shaft 30. The thermoplastic resin is formed and connected to the proximal end side of the inner tube shaft 30, and forms a guide wire lumen 30L (constituting a guide wire tube axis) together with the inner tube shaft 30, and the base end serves as a guide The turns 45 are open.

In Fig. 1, reference numeral 50 denotes a microtube connected to the proximal end side of the outer tube shaft 10, 60 is a stopcock attached to the proximal end side of the microtube 50, and 70 is a elastic buckle. this Further, in Figs. 2 to 4, 80 is a core wire of the dilation lumen 10L formed by being inserted into the outer tube shaft 10.

The tube shaft 10, which constitutes the balloon catheter 100, is formed with an expansion lumen 10L for circulating fluid for expanding the balloon 20.

The outer diameter of the outer tube shaft 10 is preferably 0.7 to 1.0 mm, and is a suitable example, which is 0.85 mm.

The length of the outer tube shaft 10 is preferably 150 to 450 mm, and a suitable example is shown, which is 390 mm.

Examples of the constituent material of the outer tube shaft 10 include thermoplastic resins such as polyamide, polyether polyamine, polyurethane, polyether block phthalamide (PEBAX) (registered trademark), and nylon. Among them, PEBAX is preferred.

The hardness of the outer tube shaft 10 is preferably 63 to 80 as measured by a D-type durometer.

A balloon 20 is attached to the front end of the outer tube shaft 10.

The balloon 20 is expanded by the liquid circulating in the dilation lumen 10L of the outer tubular shaft 10. Here, the liquid can be exemplified by physiological saline.

When expanding, the diameter of the balloon 20 is preferably 1.0 to 5.0 mm.

The length of the balloon 20 is preferably 5 to 40 mm.

The constituent material of the balloon 20 can be the same as the balloon constituting the balloon catheter generally known in the prior art, and a suitable material is PEBAX. The strength of the constituent material of the balloon 20 is preferably 680 MPa to 780 MPa. When the strength is too low, it tends to excessively expand, which tends to cause wrinkles and the like.

Inside the outer tube shaft 10 and the inside of the balloon 20, an inner tube shaft 30 is inserted, and the inner tube shaft 30 is formed with a guide wire lumen 30L for inserting a guide wire as a guide tube shaft.

The front end portion of the inner tube shaft 30 is fixed to the front end portion of the balloon 20, and an opening as a guide wire 35 is formed at the front end of the inner tube shaft 30.

On the other hand, as shown in Fig. 3, the proximal end portion of the inner tube shaft 30 is fixed (hot-melted) to the outer tube shaft 10 in a state in which the outer circumference of the outer tube shaft 10 is covered with the resin. .

The inner tube shaft 30 is composed of an inner layer 31 composed of a thermoplastic resin that cannot be fused to the outer tube shaft 10, and an outer layer 32 composed of a thermoplastic resin that can be fused to the outer tube shaft 10. .

The outer diameter of the inner tube shaft 30 is preferably 0.48 to 0.60 mm. Further, the inner diameter of the inner tube shaft 30 is preferably from 0.35 to 0.45 mm.

The thickness of the inner layer 31 is preferably 0.005 to 0.030 mm.

The thickness of the outer layer 32 is preferably 0.01 to 0.10 mm.

The constituent material of the inner layer 31 is preferably a resin having a low friction coefficient and a good lubricity. Specific examples thereof include polyolefins such as polyethylene, fluorine resins such as PFA and PTFE, and the like. Among them, polyethylene is preferred. .

The constituent material of the outer layer 32 is exemplified as a thermoplastic resin constituting the outer tube shaft 10, and among them, PEBAX is preferable.

The hardness of the inner tube shaft 30 (outer layer 32) is preferably 55 or more in terms of the hardness measured by the D-type durometer from the viewpoint of ensuring the rigidity of the guide tube shaft.

As shown in Fig. 3, a connecting pipe 40 is connected and fixed (hot-melted) to the proximal end side of the inner tube shaft 30.

The connecting tube 40 forms a guide wire lumen 30L together with the inner tube shaft 30. That is, in the balloon catheter 100 of the present embodiment, the inner tube shaft 30 and the connecting tube 40 constitute a guide wire shaft, and an opening as the guide wire 45 is formed at the proximal end of the connecting tube 40.

The outer diameter and the inner diameter of the connecting pipe 40 are set to be equal to the outer diameter and the inner diameter of the inner pipe shaft 30, respectively.

The length (L40) of the connecting pipe 40 is preferably 1 to 5 mm.

When the length (L40) is too short, the object of the present invention cannot be sufficiently achieved. On the other hand, when the length (L40) is too long, the lubricity of the guide wire lumen 30L may be impaired.

The connecting pipe 40 is a single pipe composed of a thermoplastic resin which can be fused to the outer tube shaft 10 and the outer layer 32 of the inner tube shaft 30.

The constituent material of the connecting pipe 40 is exemplified as a thermoplastic resin constituting the outer tubular shaft 10, and among them, PEBAX and nylon are preferable.

The hardness of the connecting pipe 40 is preferably 70 or more, and particularly preferably 72 or more, from the viewpoint of ensuring the rigidity of the guide wire shaft.

The metal microtube 50 constituting the balloon catheter 100 of the present embodiment is inserted into the proximal end portion of the outer tubular shaft 10, and the proximal end portion is inserted into the elastic buckle 70 and the stopcock 60.

The microtube 50 is made of stainless steel, Ni-Ti, Cu-Mn-Al alloy, etc. In the configuration, a spiral slit can be formed in the front end portion.

The length of the microtube 50 is usually 900 to 1500 mm.

An opening (a balloon expansion port 65) for introducing a fluid for expanding the balloon 20 is formed at a proximal end portion of the stopcock 60 attached to the microtube 50. The stopcock 60 is provided with a charging device, and the pressure device is used to adjust the pressure for expanding the balloon.

The recommended expansion pressure (NP) of the balloon catheter 100 of the present embodiment is preferably 8 atm or more, and more preferably 10 to 14 atm.

Further, the maximum expansion pressure (RBP) is preferably 18 atm or more, more preferably 20 to 25 atm.

The balloon catheter of the present invention is effective in this high withstand voltage specification.

In the balloon catheter 100 of the present embodiment, a tube for forming a tube shaft constituting the same can be manufactured by thermal fusion.

Specifically, as shown in FIGS. 5 and 6, the first tube 10A for forming the distal end side of the outer tube shaft 10 and the second tube 10B for forming the proximal end side of the outer tube shaft 10 are disposed. a third tube 30A for forming the inner tube shaft 30, and a fourth tube 40A for forming the connecting tube 40, and inserting the mandrel 90 (to ensure the mandrel of the guide wire lumen) into the third tube The lumen of the 30A and the lumen of the fourth tube 40A are inserted into the lumen of the first tube 10A and the lumen of the second tube 10B to ensure that the dilating lumen (not shown) is inserted.

As shown in Fig. 6, the first pipe 10A and the second pipe 10B are fitted by inserting a pipe wall of the front end portion of the latter into a slit formed in the pipe wall of the base end portion of the former. In addition, it is disposed in the second tube 10B The outer third tube 30A is inserted into the first tube 10A. Further, the fourth tube 40A is disposed on the proximal end side of the third tube 30A.

The shrink tube is coated on the first tube 10A, the second tube 10B, the third tube 30A, and the fourth tube 40A arranged as described above, and is heated and pressurized by the shrink tube, whereby the tubes are thermally fused to each other. fixed. Then, the mandrel for securing the guide lumen and the mandrel for ensuring the expansion of the lumen are removed, whereby a balloon catheter having the structural portions as shown in Figs. 2 to 4 can be obtained.

In the above-described melting step, in order to surely heat the first tube 10A and the second tube 10B for forming the outer tube shaft 10 and the third tube 30A for forming the inner tube shaft 30, the heating is performed in a concentrated manner. 6 is a region M surrounded by a broken line, and as a result, the thermoplastic resin located in the region, in particular, the thermoplastic resin constituting the base end portion of the third tube 30A (the constituent resin of the inner layer 31A and the outer layer 32A) The resin) is completely melted.

On the other hand, most of the fourth tube 40A disposed on the proximal end side of the third tube 30A is located at a position away from the region M from the concentrated heating to the proximal end, so that the melting step is performed. In the middle, the thermoplastic resin constituting the distal end portion of the fourth tube 40A is slightly melted and is thermally fused with the first tube 10A, the second tube 10B, and the third tube 30A, but the thermoplastic resin constituting the fourth tube 40A is hardly formed. Since it flows out to the proximal end side, it is connected and fixed (heat-melted) on the proximal end side of the third tube 30A.

With this, in the melting step, even if the thermoplastic resin constituting the proximal end portion of the third tube 30A is melted and flows toward the proximal end side, the The flow will also be blocked by the fourth tube 40A. As a result, it is possible to suppress a decrease in thickness (thinning) of the inner tube shaft due to the outflow of the resin constituting the third tube 30A, and it is possible to maintain the desired thickness of the inner tube shaft 30.

Further, in the fusing step, the inner layer 31A of the third tube 30A which is in contact with the outer peripheral surface of the mandrel 90 is covered by the outer layer 32A and the fourth tube 40A of the third tube 30A which are thermally fused to each other. The constituent resin of the inner layer 31A of the third tube 30A does not flow out toward the proximal end side.

Thereby, the blade-shaped pieces (burrs) constituting the resin from the inner layer 31A are not formed in the vicinity of the opening (guide wire 45) of the connecting pipe 40 formed by the fourth pipe 40A. Therefore, it is not necessary to perform the work of removing such chips (burrs), which is extremely advantageous from the viewpoint of manufacturing efficiency and the like.

According to the balloon catheter 100 of the present embodiment, it is possible to reduce the thickness (thinning) of the inner tube shaft due to the outflow of the constituent resin of the third tube 30A to the proximal end side, which is a problem in the conventional balloon catheter. In this case, the inner tube shaft 30 is maintained at a desired wall thickness.

Further, since the rigidity of the tube shaft is maintained by maintaining the thickness of the inner tube shaft 30, the balloon catheter 100 of the present embodiment is used (when the balloon 20 is expanded), and the balloon catheter is not formed in the conventional balloon catheter. The problem is that the stacking of the guide wires does not occur because the pressure of the liquid used to expand the balloon causes the inner tube shaft to be crushed to narrow the guide wire lumen.

Further, the blade-like pieces (burrs) which are problematic in the conventional balloon catheter are not formed in the vicinity of the guide wire 45 of the opening of the connecting tube 40 formed by the fourth tube 40A.

The above describes an embodiment of the present invention, but the present invention It is not limited to this, and various changes are possible.

For example, the outer layer of the inner tube shaft or the connecting tube can be formed by a plurality of layers.

Claims (5)

A balloon catheter characterized by comprising: an outer tube shaft formed of a thermoplastic resin; a balloon attached to a front end of the outer tube shaft and circulating through a dilation lumen formed in the outer tube shaft ( The liquid tube is expanded; the inner tube shaft is provided with an inner layer composed of a thermoplastic resin that cannot be fused to the outer tube shaft, and a thermoplastic resin that can be fused to the outer tube shaft. The outer layer is formed with a guide wire lumen inserted through the inner portion of the outer tube shaft and the inside of the balloon for inserting the guide wire, and the front end portion of the inner tube shaft is fixed to the balloon The front end portion has an opening formed as a guide wire; and a single-layer connecting pipe is formed of a thermoplastic resin which can be fused to the outer tube shaft and the outer layer of the inner tube shaft, and is connected The base end of the inner tube shaft forms a guide wire lumen together with the inner tube shaft, and is directly connected to the outer tube shaft. The base end serves as a guide wire and is open on a side surface of the outer tube shaft. The balloon catheter according to claim 1, wherein the first tube on the distal end side of the outer tube shaft is formed, and the base end side of the outer tube shaft is formed to be disposed on the base of the first tube. a second tube on the end side, the inner tube and the outer layer, and a third tube that is inserted into the inner tube shaft to be inserted into the first tube, and a third tube for forming the connecting tube The fourth tube composed of a single layer on the proximal end side of the third tube is formed by heat fusion. The balloon catheter according to claim 1 or claim 2, wherein the thermoplastic resin constituting the outer tube shaft, the outer layer of the inner tube shaft, and the connecting tube is selected from the group consisting of polyamine, polyether polyamine, At least one of a polyurethane, a polyether block amide, and a nylon, and a thermoplastic resin constituting an inner layer of the inner tube shaft, is a polyolefin or a fluorine resin. The balloon catheter according to claim 1 or 2, wherein the outer tube shaft, the outer layer of the inner tube shaft, and the thermoplastic resin of the connecting tube are polyether block amide or nylon, and the inner portion is formed. The thermoplastic resin of the inner layer of the tube shaft is polyethylene. The balloon catheter according to claim 1, wherein the connecting tube is made of a thermoplastic resin having a hardness of 70 or more as measured by a D-type durometer.