JP2018007873A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter having excellent insertability into a blood vessel site and, even when an inner tube and a distal tip are not fused to each other, capable of reliably holding the distal tip, and preventing kink at the distal side of the balloon.SOLUTION: The balloon catheter includes an outer tube 10, a balloon 30, an inner tube 40, and a distal tip 50. A distal-side neck section 32 of the balloon 30 includes: a proximal end 321 having a first outside diameter D1 and a first inside diameter d1; a distal end 322 having a second inside diameter d2 smaller than the first inside diameter; and a step part 323 formed at a boundary of the proximal end and the distal end. A distal end 42 of the inner tube 40 is fixed to the proximal end 321 of the distal-side neck section 32 by bonding an outer peripheral face 426 thereof with an inner peripheral face 327 of the proximal end 321 of the tip-side neck section 32 in a state where a distal end surface 425 and the step part 323 of the distal-side neck section 32 are bonded. A proximal end 51 of the distal tip 50 is fixed by fusion to the distal end 322 of the tip-side neck part 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a balloon catheter, and more particularly to a balloon catheter suitably used for PTCA (percutaneous coronary angioplasty) and peripheral PTA (percutaneous angioplasty).

  Conventionally, as a balloon catheter introduced into a patient's blood vessel, the outer tube has neck portions at both ends of the balloon portion that expands and contracts, and the proximal end neck portion is fixed to the distal end portion of the outer tube. A balloon, an outer tube lumen, an inner tube inserted into the balloon to form a guide wire lumen, and a tip made of a soft tube material forming a lumen communicating with the inner tube lumen are provided. Known (see Patent Documents 1 and 2 below).

  FIG. 6 is a cross-sectional view showing the distal end shape of the balloon catheter described in Patent Document 1. In the balloon catheter 600 shown in FIG. 6, the outer peripheral surface of the distal end portion 642 of the inner tube 640 and the proximal end of the distal end tip 650 are shown. The inner peripheral surface of the portion 651 is joined, and the outer peripheral surface of the proximal end portion 651 of the distal tip 650 and the inner peripheral surface of the distal side neck portion 632 of the balloon 630 are joined.

  FIG. 7 is a cross-sectional view showing the distal end shape of the balloon catheter described in Patent Document 2. In the balloon catheter 700 shown in FIG. 7, the distal end surface of the inner tube 740 and the proximal end surface of the distal end tip 750 are welded. The distal neck portion 732 of the balloon 730 is stretched over and joined to both the outer peripheral surfaces of the inner tube 740 and the distal tip 750.

JP-A-5-192410 JP 2005-160536 A

  Balloon catheters used in PTCA (percutaneous coronary angioplasty) and peripheral PTA (percutaneous angioplasty) are required to be able to be inserted into narrow blood vessels such as stenosis. It is necessary to reduce the wrapping diameter (the diameter when the balloon is wound around the inner tube) by using the inner tube having a small diameter.

On the other hand, in recent balloon catheters for PTCA, high pressure resistance (for example, maximum expansion pressure (RBP) is 18 atm or more) is required.
The inner tube constituting such a high pressure balloon catheter prevents the guide wire from being stuck due to irreversible deformation (collapse of the guide wire lumen) caused by repeated expansion and contraction of the balloon. In order to maintain the properties, it is necessary to increase the thickness and increase the strength.
However, when the thickness of the inner tube is increased, the outer diameter of the inner tube is inevitably increased, so that the balloon catheter provided with such an inner tube cannot be inserted into a thin blood vessel site.

The balloon catheter used for the peripheral PTA is provided with a long balloon (for example, 40 to 300 mm) corresponding to the length of the stenosis.
The balloon catheter for peripheral PTA provided with such a long balloon has a problem that it is inferior in pushability when inserted through a blood vessel.
Here, in order to improve pushability, it is conceivable to increase the thickness of the inner tube to increase the strength. However, if the thickness of the inner tube is increased, as in the case of the balloon catheter for PTCA. In the balloon catheter provided with such an inner tube, the penetrability with respect to a thin blood vessel site is impaired.

  In order to solve the above-mentioned problems, the present inventors are composed of PEEK resin as a balloon catheter that has excellent penetrability into narrow blood vessels such as a stenosis and has high pressure resistance and excellent pushability. Has proposed a balloon catheter having one of the features (see Japanese Patent Application No. 2006-14403).

  However, in the balloon catheter described in Patent Document 1, welding is performed in a state where the distal end portion of the inner tube, the proximal end portion of the distal end tip, and the distal end side neck portion of the balloon are laminated on the distal end side of the balloon. Since it is (thermally welded), even if a small-diameter inner tube made of PEEK resin is adopted, the above-mentioned welded part becomes considerably thick, so that the penetrability with respect to a thin blood vessel part is inferior.

In addition, the balloon catheter described in Patent Document 2 has a problem in that the hardness (rigidity) greatly changes at the interface between the inner tube and the tip, and thus kinks are likely to occur at the interface.
In particular, when an inner tube made of PEEK resin is employed, PEEK resin usually cannot be welded (thermally welded) to the constituent material of the tip, so the tip surface of the inner tube and the base end surface of the tip are simply In addition, since the change in hardness at the interface becomes considerably large, kinks at the interface are very likely to occur.
Further, in the balloon catheter described in Patent Document 2, when the inner tube made of PEEK resin is adopted, the tip may not be held and the tip may fall off. .

The present invention has been made based on the above situation.
An object of the present invention is to make the outer diameter on the distal end side of the balloon sufficiently small so that it can be easily inserted into a thin blood vessel site, and the inner tube and the distal end tip are made of a material that cannot be welded to each other. Even in such a case, it is an object to provide a balloon catheter that can reliably hold the distal tip and does not cause kinking on the distal end side of the balloon.

(1) The balloon catheter of the present invention comprises an outer tube,
A balloon having neck portions at both ends of a balloon portion that expands and contracts, and a proximal neck portion fixed to the distal end portion of the outer tube; and
An inner tube having a distal end portion that is inserted into the lumen of the outer tube and the balloon to form a guide wire lumen, and is fixed to the distal end side neck portion of the balloon;
A distal end tip made of a soft tube material having a proximal end portion fixed to the distal end neck portion of the balloon, forming a lumen communicating with the lumen of the inner tube, and having an opening at the distal end thereof; Become;
The distal neck portion of the balloon includes a proximal end portion having a first outer diameter (D1) and a first inner diameter (d1), and a distal end portion having a second inner diameter (d2) smaller than the first inner diameter (d1). A step portion formed at a boundary between the base end portion and the tip end portion;
The distal end portion of the inner tube has an outer peripheral surface thereof and an inner peripheral surface of the proximal end portion of the distal end side neck portion in a state where the distal end surface and the stepped portion of the distal end side neck portion are welded, bonded, or abutted. Is fixed to the proximal end of the distal end side neck portion by being welded or bonded,
The proximal end portion of the distal end tip is fixed by being welded to the distal end portion of the distal end side neck portion.

  According to the balloon catheter having such a configuration, the distal end portion of the inner tube is fixed to the “proximal end portion” of the distal end side neck portion, and the proximal end portion of the distal end tip is connected to the “distal end portion” of the distal end side neck portion. Since it is fixed, on the distal end side of the balloon, the distal end portion of the inner tube, the distal end side neck portion of the balloon, and the proximal end portion of the distal end tip are not stacked (three-layer configuration), Therefore, the outer diameter on the tip side of the balloon can be made sufficiently small.

  In addition, with the tip surface of the tip of the inner tube and the stepped portion of the tip neck on the tip side welded, adhered, or abutted, the inner peripheral surface of the tip of the inner tube and the base end of the tip neck Since the distal end of the inner tube is fixed to the proximal end of the distal end neck portion, the distal end portion of the inner tube is covered with the distal end neck portion. And it is being fixed to the base end part of the front end side neck part. Thereby, the kink in the interface of an inner tube and a front end side neck part can be prevented.

  Even when the inner tube and the balloon are made of a material that cannot be welded together, the tip of the inner tube is made to be the base of the tip side neck by modifying the outer peripheral surface of the tip of the inner tube. Can be glued to the end.

  On the other hand, since the proximal end portion of the distal tip is welded to the distal end portion of the distal neck portion, the proximal end portion of the distal tip can be firmly fixed to the distal end portion of the distal neck portion.

  As a result, even when the inner tube and the tip are made of materials that cannot be welded together, the tip can be fixed to the tip of the inner tube via the tip neck of the balloon. As a result, the tip can be securely held.

(2) In the balloon catheter according to the present invention, the distal end portion of the distal-end-side neck portion is outward in the distal direction with the first outer diameter (D1) as the maximum outer diameter and the second outer diameter (D2) as the minimum outer diameter. Having a tapered portion with a reduced diameter;
The proximal end portion of the tip has a maximum inner diameter substantially the same as the first outer diameter (D1) and a minimum inner diameter substantially the same as the second outer diameter (D2). Having a tapered portion
By welding the inner peripheral surface of the proximal end portion of the distal tip and the outer peripheral surface of the distal end portion of the distal end neck portion, the proximal end portion of the distal tip is fixed to the distal end portion of the distal end neck portion. It is preferable.

  According to the balloon catheter having such a configuration, the hardness in the welded portion between the distal end portion of the distal end side neck portion and the proximal end portion of the distal end tip can be continuously changed in the axial direction. It can be surely prevented.

(3) In the balloon catheter of the present invention, it is preferable that the inner tube is made of PEEK resin.

(4) The balloon catheter of the present invention comprises a metal tube connected to the proximal end of the outer tube and a hub connected to the proximal end of the metal tube, and is a PTCA (percutaneous coronary angioplasty). It is preferable to be used for.

(5) The balloon catheter of the present invention preferably comprises a hub connected to the proximal end of the outer tube and is used for peripheral PTA (percutaneous angioplasty).

According to the balloon catheter of the present invention, the outer diameter on the distal end side of the balloon can be made sufficiently small, and the insertability to a thin blood vessel site can be made excellent.
Even if the inner tube and the tip are made of materials that cannot be welded (thermally welded) to each other, the tip can be securely held and the interface between the inner tube and the tip neck Kink can be prevented.

1 is a cross-sectional view schematically showing a balloon catheter according to a first embodiment of the present invention. It is a partial expanded sectional view of the balloon catheter which concerns on 1st Embodiment (II part detail drawing of FIG. 1). It is a partial expanded sectional view which shows the modification of the balloon catheter which concerns on 1st Embodiment. It is sectional drawing which shows typically the balloon catheter which concerns on 2nd Embodiment of this invention. It is the elements on larger scale of the balloon catheter which concerns on 2nd Embodiment (the V section detail drawing of FIG. 4). It is sectional drawing which shows the shape of the front-end | tip part of the conventional balloon catheter. It is sectional drawing which shows the shape of the front-end | tip part of the conventional balloon catheter.

<First Embodiment>
The balloon catheter 100 of this embodiment shown in FIGS. 1 and 2 is used for PTCA (percutaneous coronary angioplasty).

This balloon catheter 100 includes an outer tube 10 (front end side shaft), a metal tube 20 connected to the base end of the outer tube 10 (base end side shaft), and neck portions (bases) at both ends of the balloon portion 33 that expands and contracts. A balloon 30 having an end-side neck portion 31 and a distal-side neck portion 32), and the proximal-side neck portion 31 fixed to the distal end portion of the outer tube 10; the lumen of the outer tube 10; The inner tube 40 having a distal end portion 42 fixed to the distal end side neck portion 32 of the balloon 10 and the proximal end portion 51 fixed to the distal end side neck portion 32 of the balloon 30 are formed. A soft tube having a lumen communicating with the lumen of the inner tube 40 and having an open end. And a core wire 60 inserted through the lumen of the outer tube 10, and the base end portion 41 of the inner tube 40 opens at the side surface of the outer tube 10 to open the guide wire port P. A distal exchange neck portion 32 of the balloon 30 includes a proximal end portion 321 having a first outer diameter (D1) and a first inner diameter (d1), and a first inner diameter (d1). ) A tapered portion 3221 having a smaller second inner diameter (d2), a first outer diameter (D1) as the maximum outer diameter, and a second outer diameter (D2) as the minimum outer diameter, and the outer diameter decreasing in the distal direction. And a step 323 formed at the boundary between the proximal end 321 and the distal end 322; the distal tip 50 has a first outer diameter (D1). In addition to having the same outer diameter, the base end portion 51 of the tip 50 has a maximum inner diameter that is substantially the same as the first outer diameter (D1) and a minimum inner diameter that is substantially the same as the second outer diameter (D2). The tip portion 42 of the inner tube 40 has an outer peripheral surface 426 in a state where the tip surface 425 and the stepped portion 323 of the tip side neck portion 32 are bonded. And the inner peripheral surface 327 of the proximal end portion 321 of the distal end side neck portion 32 are bonded to each other, so that the proximal end portion 321 of the distal end side neck portion 32 is fixed. The balloon catheter is fixed to the distal end portion 322 of the distal end side neck portion 32 by welding the peripheral surface 517 and the outer peripheral surface 326 of the distal end portion 322 of the distal end side neck portion 32.
In FIG. 1, 70 is a hub attached to the proximal end of the metal tube 20, and 80 is a strain relief.

  The outer tube 10 constituting the balloon catheter 100 is formed with a lumen (expansion lumen) through which a fluid for expanding and contracting the balloon 30 flows.

The outer tube 10 is made of a thermoplastic resin such as a polyamide resin.
Examples of the polyamide resin that constitutes the outer tube 10 include thermoplastic resins such as polyamide, polyether polyamide, polyether block amide [PEBAX (registered trademark)], and nylon. Of these, PEBAX is preferable.
The hardness of the resin constituting the outer tube 10 is preferably 63-80 as measured by a D-type hardness meter.
The outer tube 10 may be made of a polyamide resin having the same hardness along the axial direction, but may be integrally formed using a polyamide resin having a different hardness along the axial direction.

The outer diameter of the outer tube 10 is usually 0.70 to 0.90 mm, and is 0.75 mm if a suitable example is shown.
The inner diameter of the outer tube 10 is normally 0.55 to 0.75 mm, and 0.62 mm if a suitable example is shown.
The length of the outer tube 10 is usually 150 to 450 mm, preferably 200 to 400 mm.

The metal tube 20 constituting the balloon catheter 100 is formed with a lumen (expansion lumen) communicating with the lumen of the outer tube 10.
The metal tube 20 is made of stainless steel, a Ni—Ti alloy, a Cu—Mn—Al alloy, or the like, and a spiral slit may be formed at the tip of the metal tube 20.

  As shown in FIG. 1, the distal end portion of the metal tube 20 is inserted into the proximal end portion of the outer tube 10, and the proximal end portion of the metal tube 20 is inserted into the hub 70.

The outer diameter of the metal tube 20 is usually 0.50 to 0.80 mm, and 0.65 mm if a suitable example is shown.
The inner diameter of the metal tube 20 is usually 0.40 to 0.50 mm, and is 0.45 mm if a suitable example is shown.
The length of the metal tube 20 is usually 900 to 1500 mm, and preferably 1000 to 1200 mm.

The balloon 30 constituting the balloon catheter 100 includes a balloon portion 33 that expands and contracts, a proximal neck portion 31, and a distal neck portion 32.
The proximal end side neck portion 31 is fixed to the distal end portion of the outer tube 10, so that the balloon 30 is attached to the distal end of the outer tube 10.
The balloon 30 (balloon portion 33) is expanded by the liquid flowing through the lumens of the outer tube 10 and the metal tube 20. Here, examples of the liquid include physiological saline and a contrast medium.

The balloon 30 is made of a thermoplastic resin such as a polyamide resin.
Examples of the polyamide resin constituting the balloon 30 include thermoplastic resins such as polyamide, polyether polyamide, PEBAX, and nylon. Of these, nylon such as nylon 12 is preferable.
The hardness of the resin constituting the balloon 30 is preferably 70 to 90 as measured by a D-type hardness meter.
The diameter of the balloon 30 (balloon portion 33) at the time of expansion is usually 1.0 to 5.0 mm, preferably 2.0 to 3.5 mm.
The length of the balloon 30 is usually 5 to 40 mm, preferably 15 to 30 mm.

  As shown in FIG. 2, the distal end side neck portion 32 of the balloon 30 includes a proximal end portion 321 having a first outer diameter (D1) and a first inner diameter (d1), and a second smaller than the first inner diameter (d1). A distal end portion 322 having an inner diameter (d2) and having a tapered portion 3221 in which the first outer diameter (D1) is the maximum outer diameter and the second outer diameter (D2) is the minimum outer diameter and the outer diameter decreases in the distal direction. And a step portion 323 formed at the boundary between the base end portion 321 and the tip end portion 322.

As a 1st outer diameter (D1) which is an outer diameter of the base end part 321, it is 0.50-1.30 mm normally, and will be 0.60 mm if a suitable example is shown.
Moreover, as a 1st internal diameter (d1) which is an internal diameter of the base end part 321, it is 0.45-0.60 mm normally, and will be 0.48 mm if a suitable example is shown.

The tip 322 has a second inner diameter (d2) that is smaller than the first inner diameter (d1).
The distal end portion 322 has a tapered portion 3221 in which the first outer diameter (D1) is the maximum outer diameter and the second outer diameter (D2) is the minimum outer diameter, and the outer diameter decreases in the distal direction. And a straight portion 3222 having a second outer diameter (D2).

As a 2nd outer diameter (D2) which is the minimum outer diameter of the front-end | tip part 322, it is 0.41-1.20 mm normally, and will be 0.45 mm if a suitable example is shown.
Moreover, the 2nd internal diameter (d2) which is an internal diameter of the front-end | tip part 322 is substantially the same as the internal diameter of the inner tube 40 mentioned later, and is normally 0.35-0.55 mm, 0.40 mm if a suitable example is shown. It is said.

  The inner tube 40 constituting the balloon catheter 100 is inserted into the lumen of the outer tube 10 and the inside (lumen) of the balloon 30, and a guide wire lumen is formed by the inner tube 40.

  As shown in FIG. 1, the base end portion 41 of the inner tube 40 is opened on the side surface of the outer tube 10 to form a guide wire port P.

The inner tube 40 is made of PEEK (polyether ether ketone) resin.
The PEEK resin that is a constituent material of the inner tube 40 is a crystalline thermoplastic resin having excellent mechanical properties.

  By forming the inner tube 40 of the balloon catheter 100 with PEEK resin having excellent mechanical properties, the inner tube 40 is deformed (collapse of the guide wire lumen) even after repeated expansion and contraction of the balloon 30 under high pressure conditions. Is less likely to occur. Thereby, the balloon catheter 100 can exhibit high pressure resistance (excellent stack resistance), and can be suitably used as a balloon catheter for PTCA requiring high pressure resistance.

The high pressure resistance (excellent stacking resistance) of the balloon catheter 100 can be achieved even when the thickness (wall thickness) of the inner tube 40 is reduced.
Here, the wall thickness (wall thickness) of the inner tube 40 is usually 0.02 to 0.06 mm, and 0.04 mm if a suitable example is shown, and is an inner made of a polyamide resin constituting a conventional balloon catheter. It is small compared with the thickness of the tube (for example, 0.05 to 0.09 mm).

  By reducing the thickness of the inner tube 40 as described above, the outer diameter of the inner tube 40 can be reduced, and as a result, the wrapping diameter and the outer diameter on the distal end side of the balloon can be sufficiently reduced. As a result, the balloon catheter 100 of the present embodiment provided with the inner tube 40 is excellent in penetrability into a thin blood vessel site such as a stenosis.

  As shown in FIG. 2, the distal end portion 42 of the inner tube 40 is formed so that the distal end surface 425 and the stepped portion 323 of the distal end side neck portion 32 are bonded together, and the outer peripheral surface 426 and the distal end side neck portion 32 are connected to each other. By being bonded to the inner peripheral surface 327 of the end portion 321, the end portion 321 is fixed to the proximal end portion 321 of the distal end side neck portion 32.

  Here, since the melting point of the PEEK resin constituting the inner tube 40 and the melting point of the thermoplastic resin (polyamide resin) constituting the balloon 30 are greatly different, the tip surface 425 of the tip portion 42 of the inner tube 40, The stepped portion 323 of the side neck portion 32 cannot be thermally welded, and the outer peripheral surface 426 of the distal end portion 42 of the inner tube 40 and the inner peripheral surface 327 of the proximal end portion 321 of the distal end side neck portion 32 are connected. Although it cannot be thermally welded, the front end surface 425 and the outer peripheral surface 426 of the inner tube 40 are surface-modified so that the front end surface 425 and the stepped portion 323 and the outer peripheral surface 426 and the inner peripheral surface 327 are modified. As a result, an adhesive force is developed between the distal end portion 42 of the inner tube 40 and the proximal end portion 321 of the distal end side neck portion 32. It is.

  Further, since the distal end portion 42 of the inner tube 40 is covered with the distal end side neck portion 32 and is fixed to the proximal end portion 321 of the distal end side neck portion 32, the inner tube 40 and the distal end side neck portion 32 are Kinks at the interface (adhesive surface between the tip surface 425 and the stepped portion 323) can be prevented.

The hardness of the resin constituting the inner tube 40 is preferably higher than the hardness of the constituent resin of the balloon 30 and is 85 or more as measured by a D-type hardness meter.
The outer diameter of the inner tube 40 is usually 0.40 to 0.60 mm, and is 0.48 mm if a suitable example is shown.
The inner diameter of the inner tube 40 is usually 0.35 to 0.55 mm, and is 0.40 mm if a suitable example is shown.

In the balloon catheter 100 of the present embodiment, the axial distance (L1) from the formation position of the guide wire port P to the proximal end position of the balloon 30 is usually 150 to 300 mm.
The axial distance (L2) from the formation position of the guide wire port P to the tip of the metal tube 20 is usually 0 to 200 mm.

The distal tip 50 constituting the balloon catheter 100 has a proximal end portion 51 and a distal end portion 52, and is fixed to the distal end portion 322 of the distal end neck portion 32 of the balloon 30 at the proximal end portion 51.
The distal tip 50 is formed with a lumen (extended lumen) that communicates with the lumen of the inner tube 40, and the distal end of the distal tip 50 is open.

When the balloon catheter 100 is inserted into a blood vessel, the distal tip 50 is made of a soft (low hardness) resin tube material so that the distal end portion does not damage the blood vessel.
Here, the hardness of the resin constituting the tip 50 is lower than the hardness of the constituent resin of the balloon 30 and is preferably 40 to 72 as measured by a D-type hardness meter.
The distal end tip 50 is fixed to the distal end portion 42 of the inner tube 40 via the distal end side neck portion 32 of the balloon 30, and the inner tube 40, the distal end side neck portion 32, and the distal end tip 50 are arranged in this order from the proximal end side. In the balloon catheter 100 of the present embodiment, the hardness of the constituent resin of the distal tip 50 is lower than the hardness of the constituent resin of the balloon 30, and the hardness of the constituent resin of the inner tube 40 is higher than the hardness of the constituent resin of the balloon 30. As a result, the change in hardness from the inner tube 40 to the tip 50 becomes moderate, and this can also suppress the generation of kinks.

  The constituent resin of the tip 50 is selected from resins that can be thermally welded to the constituent resin of the balloon 30, and specific examples thereof include polyamide, polyether amide, PEBAX, nylon, and polyurethane.

  As shown in FIG. 2, the distal tip 50 (the proximal end portion 51 and the distal end portion 52) has an outer diameter that is substantially the same as the first outer diameter (D1) that is the outer diameter of the proximal end portion 321 of the distal end side neck portion 32. have.

  The distal end portion 52 of the distal end tip 50 has an inner diameter that is substantially the same as the second inner diameter (d2) that is the inner diameter of the distal end portion 322 of the distal end side neck portion 32.

  The proximal end portion 51 of the distal tip 50 has an inner diameter substantially the same as the first outer diameter (D1) as a maximum inner diameter, and a second outer diameter (D2) that is the minimum outer diameter of the distal end portion 322 of the distal end neck portion 32. The taper portion 511 has a substantially the same inner diameter as a minimum inner diameter and the inner diameter decreases in the distal direction, and a straight portion 512 having a constant inner diameter.

  The thermoplastic resin (polyamide resin) constituting the distal tip 50 and the thermoplastic resin constituting the balloon 30 can be thermally welded, and the proximal end portion 51 (tapered portion 511 and straight portion 512) of the distal tip 50 is provided. When the inner peripheral surface 517 of the distal end tip 50 is welded to the outer peripheral surface 326 of the distal end portion 322 (tapered portion 3221 and straight portion 3222) of the distal end side neck portion 32, the proximal end portion 51 of the distal end tip 50 becomes the distal end side neck. The tip 32 of the part 32 is firmly fixed to the tip 322.

  As described above, the proximal end portion 51 of the distal end tip 50 is firmly fixed to the distal end portion 322 of the distal end side neck portion 32. As described above, the distal end surface 425 and the outer peripheral surface 426 of the inner tube 40 are surface-modified. As a result, the distal end portion 42 of the inner tube 40 is bonded to the proximal end portion 321 of the distal end side neck portion 32, so that the distal end tip 50 and the inner tube 40 are made of a material that cannot be thermally welded to each other. Even so, the proximal end portion 51 of the distal end tip 50 can be reliably fixed to the distal end portion 42 of the inner tube 40 via the distal end side neck portion 32 of the balloon 30.

  Further, since the tapered portion 3221 of the distal end portion 322 of the distal end side neck portion 32 and the tapered portion 511 of the proximal end portion 51 of the distal end tip 50 are welded, the hardness at the welded portion continuously changes in the axial direction. Therefore, kinking at the welded portion can also be prevented.

  The core wire 60 constituting the balloon catheter 100 includes a straight portion 61 and a tapered portion 62. The core wire 60 is inserted into the lumen of the outer tube 10 with the tapered portion 62 as the distal end side, and a part of the proximal end side of the core wire 60 is inserted into the lumen of the metal tube 20.

  The core wire 60 is spot-welded to the inner peripheral surface of the metal tube 20 (the inner peripheral surface at a position about 10 to 150 mm away from the distal end position of the metal tube 20 to the proximal end side) on the proximal end side of the straight portion 61. Thus, the metal tube 20 is firmly welded.

According to the balloon catheter 100 of the present embodiment, the PEEK resin having excellent mechanical properties constitutes the high-strength (hard to be crushed) inner tube 40, and thus exhibits high pressure resistance (excellent stacking resistance). be able to.
Moreover, since the high intensity | strength inner tube 40 comprised by PEEK resin can make thickness small, the outer diameter of the said inner tube 40 can be made small.
Moreover, the distal end portion 42 of the inner tube 40 is fixed to the proximal end portion 321 of the distal end side neck portion 32, and the proximal end portion 51 of the distal end tip 50 is fixed to the distal end portion 322 of the distal end side neck portion 32. In the distal end side of the balloon 30, the distal end portion of the inner tube, the distal end neck portion of the balloon, and the proximal end portion of the distal tip are not stacked (three-layer configuration). In addition, the outer diameter of the balloon on the distal end side can be reduced, so that the balloon catheter 100 of this embodiment is excellent in penetrability into a thin blood vessel site such as a stenosis.

  Even if the inner tube 40 is made of PEEK resin and the tip 50 is made of a thermoplastic resin such as polyamide resin, the tip 50 can be securely held, and the inner tube 40 and the tip side can be held. Occurrence of kinks can be prevented on the distal end side of the balloon including the interface with the neck portion 32 (bonding surface between the distal end surface 425 and the stepped portion 323).

Various modifications can be made in the balloon catheter of this embodiment.
For example, the inner tube of the balloon catheter may be made of a resin other than PEEK resin, or may be made of a material other than resin such as metal.

Moreover, although the front-end | tip part 322 of the front end side neck part 32 shown in FIG. 2 consisted of the taper part 3221 and the straight part 3222, as shown in FIG. 3, 1st outer diameter (D1) is made. A straight portion 3225 having a taper portion 3226 whose outer diameter decreases in the distal direction, and a straight portion 3227 having a second outer diameter (D2) (the straight portions exist on both sides of the taper portion). May be.
Further, the distal end portion of the distal end side neck portion may be composed only of a tapered portion whose outer diameter decreases in the distal end direction. In this case, the proximal end portion of the distal tip consists only of a tapered portion whose inner diameter decreases in the distal direction.

Second Embodiment
The balloon catheter 200 of this embodiment shown in FIGS. 4 and 5 is used for peripheral PTA (percutaneous angioplasty) of the lower limbs.

  The balloon catheter 200 has neck portions (base end side neck portion 36 and distal end side neck portion 37) at both ends of the outer tube 15 and the balloon portion 38 that expands and contracts, and the distal end portion of the outer tube 15 has a proximal end side. The balloon 35 to which the neck portion 36 is fixed, the hub 70 connected to the proximal end of the outer tube 15, the lumen of the outer tube 15 and the inside of the balloon 35 are inserted to form a guide wire lumen. A lumen having an inner tube 45 having a distal end portion 47 fixed to the distal end side neck portion 37 and a proximal end portion 56 fixed to the distal end side neck portion 37 of the balloon 35 and communicating with the lumen of the inner tube 45 A tip tip 55 made of a soft tube material having an opening at its tip, and an outer tip And a core wire 65 inserted through the lumen of the tube 15, and a rapid exchange type balloon catheter in which the proximal end portion 46 of the inner tube 45 opens on the side surface of the outer tube 15 to form a guide wire port P. The distal side neck portion 37 of the balloon 35 has a base end portion 371 having a first outer diameter (D3) and a first inner diameter (d3), and a second inner diameter (d4) smaller than the first inner diameter (d3). A distal end portion 372 having a tapered portion 3721 having a first outer diameter (D3) as a maximum outer diameter and a second outer diameter (D4) as a minimum outer diameter, and the outer diameter decreasing in the distal direction; A step portion 373 formed at the boundary between the tip portion 371 and the tip portion 372; the tip portion 55 has an outer diameter substantially the same as the first outer diameter (D3), and the tip portion 55 The proximal end portion 56 has a tapered portion 561 whose inner diameter is reduced in the distal direction with the inner diameter substantially the same as the first outer diameter (D3) as the maximum inner diameter and the inner diameter substantially the same as the second outer diameter (D4) as the minimum inner diameter. The distal end portion 47 of the inner tube 45 is in a state where the distal end surface 475 and the stepped portion 373 of the distal end side neck portion 37 are bonded to each other, and the outer peripheral surface 476 and the proximal end portion 371 of the distal end side neck portion 37 are The inner peripheral surface 377 is bonded to be fixed to the proximal end portion 371 of the distal end side neck portion 37, and the proximal end portion 56 of the distal end tip 55 is connected to the inner peripheral surface 567 and the distal end portion of the distal end side neck portion 37. The balloon catheter is fixed to the distal end portion 372 of the distal end side neck portion 37 by welding the outer peripheral surface 376 of the 372. In FIG. 4, 80 is a strain relief.

  As shown in FIG. 4, the outer tube 15 constituting the balloon catheter 200 is made of resin over the entire length from the connection position with the balloon 35 to the connection position with the hub 70. The outer tube 15 is formed with a lumen (expansion lumen) for circulating a fluid for expanding the balloon 35.

  The outer tube 15 constituting the balloon catheter 200 is formed with a lumen (expansion lumen) through which a fluid for expanding and contracting the balloon 35 is circulated.

Examples of the polyamide resin constituting the outer tube 15 include thermoplastic resins such as polyamide, polyether polyamide, PEBAX, and nylon. Among these, PEBAX is preferable.
The hardness of the resin constituting the outer tube 15 is preferably 63 to 80 as measured by a D-type hardness meter.
The outer tube 15 may be made of a polyamide-based resin having the same hardness along the axial direction, but may be integrally formed using a polyamide-based resin having different hardness along the axial direction.

The outer diameter of the outer tube 15 is usually 0.80 to 1.30 mm, and is 1.20 mm if a suitable example is shown.
The inner diameter of the outer tube 15 is usually 0.70 to 1.00 mm, and 0.85 mm if a suitable example is shown.
The length of the outer tube 15 is usually 1200 to 1700 mm, preferably 1450 to 1550 mm.
As shown in FIG. 4, the base end portion of the outer tube 15 is inserted into the hub 70.

The balloon 35 constituting the balloon catheter 200 includes a balloon portion 38 that expands and contracts, a proximal neck portion 36, and a distal neck portion 37.
The proximal end neck portion 36 is fixed to the distal end portion of the outer tube 15, so that the balloon 35 is attached to the distal end of the outer tube 15.
The balloon 35 (balloon portion 38) is expanded by the liquid flowing through the lumen of the outer tube 15. Here, examples of the liquid include physiological saline and a contrast medium.

The balloon 35 is made of a thermoplastic resin such as a polyamide resin.
Examples of the polyamide resin constituting the balloon 35 include thermoplastic resins such as polyamide, polyether polyamide, PEBAX, and nylon. Among these, nylon such as nylon 12 is preferable.
The hardness of the resin constituting the balloon 35 is preferably 70 to 90 as measured by a D-type hardness meter.

The diameter of the balloon 35 (balloon part 38) at the time of expansion is usually 1.5 to 8 mm, preferably 2 to 6 mm.
The length of the balloon 35 is usually 40 to 300 mm, preferably 50 to 200 mm, and 120 mm if a suitable example is shown.

  As shown in FIG. 5, the distal side neck portion 37 of the balloon 35 includes a proximal end portion 371 having a first outer diameter (D3) and a first inner diameter (d3), and a second smaller than the first inner diameter (d3). A tip portion 372 having an inner diameter (d4) and having a tapered portion 3721 in which the first outer diameter (D3) is the maximum outer diameter and the second outer diameter (D4) is the minimum outer diameter and the outer diameter decreases in the tip direction. And a step portion 373 formed at the boundary between the base end portion 371 and the tip end portion 372.

As a 1st outer diameter (D3) which is an outer diameter of the base end part 371, it is 0.50-1.30 mm normally, and will be 0.60 mm if a suitable example is shown.
Moreover, as a 1st internal diameter (d3) which is an internal diameter of the base end part 371, it is 0.45-0.60 mm normally, and will be 0.48 mm if a suitable example is shown.

The tip 372 has a second inner diameter (d4) that is smaller than the first inner diameter (d3).
The distal end portion 372 has a tapered portion 3721 in which the first outer diameter (D3) is the maximum outer diameter and the second outer diameter (D4) is the minimum outer diameter, and the outer diameter decreases in the distal direction. And a straight portion 3722 having a second outer diameter (D4).

As a 2nd outer diameter (D4) which is the minimum outer diameter of the front-end | tip part 372, it is 0.41-1.20 mm normally, and will be 0.45 mm if a suitable example is shown.
The second inner diameter (d4), which is the inner diameter of the distal end portion 372, is substantially the same as the inner diameter of the inner tube 45 described later, and is usually 0.38 to 0.42 mm. 0.40 mm if a suitable example is shown. It is said.

  The inner tube 45 constituting the balloon catheter 200 is inserted into the lumen of the outer tube 15 and the inside (lumen) of the balloon 35, and a guide wire lumen is formed by the inner tube 45.

  As shown in FIG. 4, the base end portion 46 of the inner tube 45 is opened on the side surface of the outer tube 15 to form a guide wire port P.

The inner tube 45 is made of PEEK resin.
The PEEK resin that is a constituent material of the inner tube 45 is a crystalline thermoplastic resin having excellent mechanical properties.

  By configuring the inner tube 45 with PEEK resin having excellent mechanical properties, the balloon catheter 200 of the present embodiment exhibits excellent pushability despite having the long balloon 35 as described above. It can be suitably used as a balloon catheter for peripheral PTA of the lower limbs.

The excellent pushability of the balloon catheter 200 can be achieved even when the thickness (wall thickness) of the inner tube 45 is reduced.
Here, the thickness (wall thickness) of the inner tube 45 is usually 0.03 to 0.05 mm, 0.04 mm if a suitable example is shown, and an inner made of a polyamide resin constituting a conventional balloon catheter. It is small compared with the thickness of the tube (for example, 0.06 to 0.08 mm).

  By reducing the thickness of the inner tube 45 as described above, the outer diameter of the inner tube 45 can be reduced, and as a result, the wrapping diameter and the outer diameter on the distal end side of the balloon can be sufficiently reduced. As a result, the balloon catheter 200 of the present embodiment including the inner tube 45 is excellent in insertability into a thin blood vessel site such as a stenosis.

  As shown in FIG. 5, the distal end portion 47 of the inner tube 45 is formed such that the distal end surface 475 and the stepped portion 373 of the distal end side neck portion 37 are bonded to each other. By being bonded to the inner peripheral surface 377 of the end portion 371, the end portion 371 is fixed to the proximal end portion 371 of the distal end side neck portion 37.

  Here, since the melting point of the PEEK resin constituting the inner tube 45 and the melting point of the thermoplastic resin (polyamide resin) constituting the balloon 35 are greatly different, the tip surface 475 of the tip portion 47 of the inner tube 45 and the tip The stepped portion 373 of the side neck portion 37 cannot be thermally welded, and the outer peripheral surface 476 of the distal end portion 47 of the inner tube 45 and the inner peripheral surface 377 of the proximal end portion 371 of the distal end side neck portion 37 are connected. Although it cannot be thermally welded, the front end surface 475 and the outer peripheral surface 476 of the inner tube 45 are surface-modified so that the front end surface 475 and the stepped portion 373 and the outer peripheral surface 476 and the inner peripheral surface 377 are modified. As a result, an adhesive force is developed between the distal end portion 47 of the inner tube 45 and the proximal end portion 371 of the distal end side neck portion 37. It is.

  Further, since the distal end portion 47 of the inner tube 45 is covered with the distal end side neck portion 37 and is fixed to the proximal end portion 371 of the distal end side neck portion 37, the inner tube 45 and the distal end side neck portion 37 are Kinks at the interface (adhesive surface between the tip surface 475 and the stepped portion 373) can be prevented.

The hardness of the resin constituting the inner tube 45 is preferably higher than the hardness of the constituent resin of the balloon 35 and is 85 or more as measured by a D-type hardness meter.
The outer diameter of the inner tube 45 is usually 0.46 to 0.50 mm, and is 0.48 mm if a suitable example is shown.
The inner diameter of the inner tube 45 is normally 0.38 to 0.42 mm, and is 0.40 mm if a suitable example is shown.

The distal tip 55 constituting the balloon catheter 200 has a proximal end portion 56 and a distal end portion 57, and is fixed to the distal end portion 372 of the distal end side neck portion 37 of the balloon 35 at the proximal end portion 56.
The distal tip 55 is formed with a lumen (extended lumen) that communicates with the lumen of the inner tube 45, and the distal end of the distal tip 55 is open.

When the balloon catheter 200 is inserted into a blood vessel, the distal tip 55 is made of a soft (low hardness) resin tube material so that the distal end portion does not damage the blood vessel.
Here, the hardness of the resin constituting the distal tip 55 is preferably lower than the hardness of the constituent resin of the balloon 35 and is 40 to 72 as measured by a D-type hardness meter.
A distal end tip 55 is fixed to the distal end portion 47 of the inner tube 45 via a distal end side neck portion 37 of the balloon 35. From the proximal end side, the inner tube 45, the distal end side neck portion 37, and the distal end tip 55 are arranged in this order. In the balloon catheter 200 of this embodiment, the hardness of the constituent resin of the distal tip 55 is lower than the hardness of the constituent resin of the balloon 35, and the hardness of the constituent resin of the inner tube 45 is higher than the hardness of the constituent resin of the balloon 35. As a result, the change in hardness from the inner tube 45 to the tip 55 becomes moderate, and this can also suppress the generation of kinks.

  The constituent resin of the tip chip 55 is selected from resins that can be thermally welded to the constituent resin of the balloon 35, and specific examples thereof include polyamide, polyether amide, PEBAX, nylon, and polyurethane.

  As shown in FIG. 5, the distal tip 55 (the proximal end portion 56 and the distal end portion 57) has an outer diameter that is substantially the same as the first outer diameter (D3) that is the outer diameter of the proximal end portion 371 of the distal end neck portion 37. have.

  The distal end portion 57 of the distal end tip 55 has an inner diameter that is substantially the same as the second inner diameter (d4) that is the inner diameter of the distal end portion 372 of the distal end side neck portion 37.

  The proximal end portion 56 of the distal end tip 55 has an inner diameter substantially the same as the first outer diameter (D3) as a maximum inner diameter, and a second outer diameter (D4) that is the minimum outer diameter of the distal end portion 372 of the distal end neck portion 37. It consists of a tapered portion 561 whose inner diameter is reduced in the tip direction with the substantially same inner diameter as a minimum inner diameter, and a straight portion 562 having a constant inner diameter.

  The thermoplastic resin (polyamide resin) constituting the distal tip 55 and the thermoplastic resin constituting the balloon 35 can be heat-welded, and the proximal end portion 56 (tapered portion 561 and straight portion 562) of the distal tip 55. The inner peripheral surface 567 and the outer peripheral surface 376 of the distal end portion 372 (tapered portion 3721 and straight portion 3722) of the distal end side neck portion 37 are welded, so that the proximal end portion 56 of the distal end tip 55 becomes the distal end side neck. It is firmly fixed to the tip 372 of the portion 37.

  As described above, the base end portion 56 of the tip end tip 55 is firmly fixed to the tip end portion 372 of the tip end neck portion 37, and as described above, the tip end surface 475 and the outer peripheral surface 476 of the inner tube 45 are surface-modified. As a result, the distal end portion 47 of the inner tube 45 is fixed to the proximal end portion 371 of the distal end side neck portion 37, so that the distal end tip 55 and the inner tube 45 are made of a material that cannot be thermally welded to each other. Even so, the proximal end portion 56 of the distal end tip 55 can be reliably fixed to the distal end portion 47 of the inner tube 45 via the distal end side neck portion 37 of the balloon 35.

  Further, since the tapered portion 3721 of the distal end portion 372 of the distal end side neck portion 37 and the tapered portion 561 of the proximal end portion 56 of the distal end tip 55 are welded, the hardness at the welded portion continuously changes in the axial direction. Therefore, kinking at the welded portion can also be prevented.

  The core wire 65 constituting the balloon catheter 200 includes a straight portion 66 and a tapered portion 67. The core wire 65 is inserted into the lumen (extended lumen) of the outer tube 15 with the taper portion 67 as a tip side.

  As shown in FIG. 4, the proximal end of the core wire 65 reaches the inside of the hub 70. Thereby, sufficient rigidity can be ensured over the entire length of the outer shaft 15.

  The core wire 65 is fixed to the inner peripheral surface of the outer tube 15 (the inner peripheral surface on the base end side from the formation position of the guide wire port P) on the base end side of the straight portion 66.

In the balloon catheter 200 of the present embodiment, the axial distance (L3) from the formation position of the guide wire port P to the rear end position of the balloon 35 varies depending on the length of the balloon 35, but is, for example, 120 to 300 mm. .
The axial distance (L4) from the position where the guide wire port P is formed to the position where the core wire 65 is fixed to the inner peripheral surface of the outer shaft 10 (fixed position 90 shown in FIG. 4) is 600 mm or less. Is more preferable, and it is more preferably 1 to 150 mm.

According to the balloon catheter 200 of the present embodiment, since the high-strength inner tube 45 is made of PEEK resin having excellent mechanical characteristics, it exhibits excellent pushability even though it has a long balloon 35. can do.
Moreover, since the high intensity | strength inner tube 45 comprised by PEEK resin can make thickness small, the outer diameter of the said inner tube 45 can be made small.
Moreover, the distal end portion 47 of the inner tube 45 is fixed to the proximal end portion 371 of the distal end side neck portion 37, and the proximal end portion 56 of the distal end tip 55 is fixed to the distal end portion 372 of the distal end side neck portion 37. In the distal end side of the balloon 35, the distal end portion of the inner tube, the distal end side neck portion of the balloon, and the proximal end portion of the distal end tip are not stacked (three-layer configuration). Further, the outer diameter of the balloon on the distal end side can be reduced, whereby the balloon catheter 200 of this embodiment is excellent in penetrability into a thin blood vessel site such as a stenosis.

  Further, even if the inner tube 45 is made of PEEK resin and the tip chip 55 is made of a thermoplastic resin such as polyamide resin, the tip chip 55 can be securely held, and the inner tube 45 and the tip side Occurrence of kinks can be prevented on the distal end side of the balloon including the interface with the neck portion 37 (bonding surface between the distal end surface 475 and the stepped portion 373).

100 balloon catheter 10 outer tube (tip shaft)
20 Metal tube (base shaft)
30 Balloon 31 Proximal neck portion 32 Proximal neck portion 321 Proximal end portion of distal neck portion 322 Proximal portion of distal neck portion 3221 Taper portion 3222 Straight portion 323 Stepped portion of distal neck portion 326 Protrusion side neck portion Outer peripheral surface of the distal end portion 327 Inner peripheral surface of the proximal end portion of the distal end side neck portion 33 Balloon portion 40 Inner tube 41 Proximal end portion of the inner tube 42 Inner tube distal end portion 425 Inner tube distal end portion distal end surface 426 Inner tube inner surface Outer peripheral surface of the tip 50 Tip tip 51 Proximal end portion of the tip tip 511 Tapered portion 512 Straight portion 517 Inner peripheral surface of the base end portion of the tip tip 52 Tip tip portion of the tip tip 60 Core wire 61 Straight portion 62 Tapered portion 70 Hub 80 Strain Relief 200 Balloon Catete 15 Outer tube 35 Balloon 36 Proximal neck portion 37 Proximal neck portion 371 Proximal end portion of distal neck portion 372 Proximal portion of distal neck portion 3721 Taper portion 3722 Straight portion 373 Step portion of distal neck portion 376 Proximal side Outer peripheral surface of the distal end portion of the neck portion 377 Inner peripheral surface of the proximal end portion of the distal end neck portion 38 Balloon portion 45 Inner tube 46 Proximal end portion of the inner tube 47 End portion of the inner tube 475 Tip surface of the distal end portion of the inner tube 476 Outer peripheral surface of the distal end portion of the inner tube 55 Tip end 56 Base end portion of the tip end 561 Tapered portion 562 Straight portion 567 Inner peripheral surface of the base end portion of the tip end 57 Tip end portion of the tip end 65 Core wire 66 Straight portion 67 Tapered portion 90 Adhering position

Claims (5)

An outer tube,
A balloon having neck portions at both ends of the balloon portion that expands and contracts, and a proximal neck portion fixed to the distal end portion of the outer tube;
An inner tube having a distal end portion that is inserted into the lumen of the outer tube and the balloon to form a guide wire lumen, and is fixed to the distal end side neck portion of the balloon;
A distal end tip made of a soft tube material having a proximal end portion fixed to the distal end neck portion of the balloon, forming a lumen communicating with the lumen of the inner tube, and having an opening at the distal end thereof; Become;
The distal neck portion of the balloon includes a proximal end portion having a first outer diameter (D1) and a first inner diameter (d1), and a distal end portion having a second inner diameter (d2) smaller than the first inner diameter (d1). A step portion formed at a boundary between the base end portion and the tip end portion;
The distal end portion of the inner tube has an outer peripheral surface thereof and an inner peripheral surface of the proximal end portion of the distal end side neck portion in a state where the distal end surface and the stepped portion of the distal end side neck portion are welded, bonded, or abutted. Is fixed to the proximal end of the distal end side neck portion by being welded or bonded,
A balloon catheter, wherein a proximal end portion of the distal tip is fixed by being welded to a distal end portion of the distal neck portion. The distal end portion of the distal neck portion has a tapered portion in which the first outer diameter (D1) is the maximum outer diameter and the second outer diameter (D2) is the minimum outer diameter, and the outer diameter decreases in the distal direction.
The proximal end portion of the tip has a maximum inner diameter substantially the same as the first outer diameter (D1) and a minimum inner diameter substantially the same as the second outer diameter (D2). Having a tapered portion
The proximal end portion of the distal end tip is fixed to the distal end portion of the distal end side neck portion by welding the inner peripheral surface of the proximal end portion of the distal end tip and the outer peripheral surface of the distal end portion of the distal end side neck portion. The balloon catheter according to claim 1, wherein the balloon catheter is formed.   The balloon catheter according to claim 1 or 2, wherein the inner tube is made of PEEK resin.   The metal tube connected to the proximal end of the outer tube and a hub connected to the proximal end of the metal tube, and used for PTCA (percutaneous coronary angioplasty). The balloon catheter according to any one of the above.   The balloon catheter according to any one of claims 1 to 3, comprising a hub connected to a proximal end of the outer tube and used for peripheral PTA (percutaneous angioplasty).

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