JP2009291501A - Balloon for balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a balloon catheter capable of being easily inserted into a lesion to the proximal side of a balloon by reducing the difference in the profile between the distal side and the proximal side of the balloon or by making the profile on the proximal side smaller than the profile on the distal side, and capable of preventing slipping. <P>SOLUTION: The catheter for the balloon catheter is composed of a tubular part having an approximately uniform wall thickness, a distal side tapered part and proximal side tapered part adjacent to both ends of the tubular part, and a distal side sleeve part and proximal side sleeve part adjacent to the tapered parts respectively. The outer diameter of the distal side sleeve is smaller than the outer diameter of the proximal side sleeve. The relations between distances L<SB>A</SB>, L<SB>B</SB>and L<SB>C</SB>from the proximal side tubular part end to positions A, B and C dividing the proximal side tapered part into four equal sections, and distances L<SB>D</SB>, L<SB>E</SB>and L<SB>F</SB>from the distal side tubular part end to positions D, E and F disposed on the distal side tapered part are L<SB>A</SB>=L<SB>F</SB>, L<SB>B</SB>=L<SB>E</SB>, and L<SB>C</SB>=L<SB>D</SB>. The relation between the wall thickness T<SB>C</SB>at the position C and the wall thickness T<SB>D</SB>at the position D is T<SB>C</SB><T<SB>D</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a medical catheter that is introduced percutaneously transluminally into the body. A balloon catheter used for performing percutaneous angioplasty such as peripheral angioplasty, coronary artery formation, and valvuloplasty is preferable.

  Percutaneous angioplasty is widely used for the purpose of expanding or treating stenosis or occlusion in the lumen of blood vessels and restoring or improving blood flow in coronary arteries and peripheral blood vessels. A balloon catheter used for percutaneous angioplasty has a structure in which a balloon is provided at a distal portion of a shaft constituted by a combination of flexible tubes. The balloon can be freely inflated or deflated by adjusting the internal pressure. A plurality of lumens are formed inside the shaft by the tube constituting the shaft. In the case of a balloon catheter, a lumen through which a guide wire is inserted (guide wire lumen) and a lumen to which a pressure fluid for adjusting balloon internal pressure is supplied are provided along the long axis direction of the shaft. A structure in which a connector for communicating a pressure device such as an inflation lumen and an inflator is generally provided on the shaft proximal side.

  Further, as shown in Patent Document 1, a conventional balloon mounted on a balloon catheter has a substantially uniform cylindrical portion, and both the distal and proximal tapers connected to the cylindrical portion have the taper. This is a structure that increases the wall thickness at the same rate of change with respect to the sleeve arranged on the outside. In other words, balloons having the same thickness are generally used at positions on the proximal side and the distal side taper that are equidistant from the proximal side cylindrical part end and the distal side cylindrical part end, respectively.

  A general procedure for percutaneous coronary angioplasty using a balloon catheter is as follows. First, a guide catheter is inserted through a sheath introducer provided at a puncture site such as a femoral artery, a brachial artery, or a radial artery, and the distal end thereof is disposed at the entrance of the coronary artery. A guide wire is then inserted into the guide catheter and advanced over the stenosis of the coronary artery. A balloon catheter is inserted along the guide wire so that the balloon portion coincides with the stenosis portion. Subsequently, the stenotic part is expanded and treated by supplying a pressure fluid to the balloon via the inflation lumen using a pressurizing device such as an indeflator and expanding the balloon. After treatment, the balloon is deflated and removed from the body.

  “Balloon slipping” is a problem with balloon catheters used in such percutaneous angioplasty.

  Balloon slipping means that the balloon slips out of the lesion when the lesion is expanded with the balloon (FIG. 2). This is likely to occur when the balloon is expanded in a procedure in a highly stenotic lesion or a calcified lesion where the balloon is not sufficiently proximal to the lesion. In other words, as shown in FIG. 2-A, slipping means that when the balloon is expanded without being inserted into the lesion, only the proximal side of the balloon is By expanding, the balloon slides proximally (hand side) as shown in FIG. When the balloon slips and slides to the proximal side, the catheter is pushed toward the proximal side, and the blood vessel may be stretched and damaged. Further, once the balloon is expanded, it is difficult to insert it again into the lesion, and another balloon catheter is used, which increases the cost.

  As a method for preventing the balloon from slipping, Patent Document 2 proposes a balloon having a larger expansion diameter at both ends than the central portion of the balloon. However, both ends may cause overexpansion, which is not practical.

  In Patent Document 3, particles are applied to the balloon surface or an annular rib is provided to prevent slipping. However, since the balloon profile becomes large, it is not practical for insertion into a high degree of stenosis.

  Patent Document 4 presents a balloon catheter provided with a braided layer for preventing slippage on the balloon surface, but the balloon profile becomes large and cannot be inserted into a high degree of stenosis.

  Patent Document 5 presents a balloon catheter in which a balloon surface is covered with a stretchable sleeve having a slit. However, since the balloon profile becomes large, it is not practical as a structure to be inserted into an advanced stenosis.

Patent Document 6 proposes that the balloon taper central portion is made thin so as to have a non-angular folding shape and improve insertability, but there is room for improvement from the viewpoint of preventing slipping.
JP 2004-187717 A JP 2000-51361 A JP 2003-79739 A JP 2008-36391 A JP 2005-278684 A JP-A-4-176473

In view of the above situation, the present invention intends to solve
It is an object of the present invention to provide a balloon for a balloon catheter that can be easily inserted into a lesion part to the proximal side of the balloon and prevents slipping.

As a result of intensive studies on the above problems, the present inventors have completed the present invention. That is, the present invention
A cylindrical portion having a substantially uniform thickness, a distal tapered portion and a proximal tapered portion adjacent to both ends of the cylindrical portion, and a distal sleeve portion and a proximal side adjacent to the tapered portion, respectively. A balloon for a balloon catheter composed of a sleeve portion, wherein the outer diameter of the distal sleeve is smaller than the outer diameter of the proximal sleeve and the proximal taper is divided into four equal positions A, B, and C. Distances L _D , L _E from the distal tubular end of D, E, F, with distances L _A , L _B , L _C located on the distal taper , L _F
L _A = L _F , L _B = L _E , L _C = L _D
The thickness TC at position _C and the thickness TD at position _D are
T _C <T _D
The present invention relates to a balloon for a balloon catheter.

In the present invention, the thickness T _E at the position _E and the thickness T _{B at the} position _B are T _E ≧ T _B ,
The thickness T _F at the position _F and the thickness T _{A at the} position A are related to a balloon where T _F ≧ T _A.

The present invention also relates to a balloon in which the thickness T _{C at} the position _C , the thickness T _{B at the} position _B, and the thickness T _{A at the} position A are in a relationship of T _C > T _B ≧ T _A.

  The present invention also relates to a balloon catheter equipped with the balloon.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to insert to the proximal side of a balloon in a lesioned part, the balloon for balloon catheters which can prevent a slipping are provided.

  Embodiments of the balloon catheter shown in the present invention will be described below.

  The proximal shown in the present invention indicates the direction toward the user's hand that is outside the body when using the catheter, and in the dilatation catheter, the dilation port is connected to an inflation lumen that is relatively in communication with the balloon. And the direction toward the connector with the port connected to the guide wire lumen. On the other hand, the distal means a direction extending from the user's hand that exists in the body at the time of use.

  A schematic diagram of a balloon catheter equipped with a balloon for a balloon catheter according to the present invention is shown in FIG. The structure of the distal part, including the balloon, has an inner tube with a lumen for passing the guide wire inside the balloon, and the balloon's distal end is concentrically connected to the inner tube The proximal end of the balloon is connected to an outer tube having a lumen for introducing pressure into the balloon, and a space in which pressure is introduced is formed by a space formed by the inner surface of the outer tube and the outer surface of the inner tube. The proximal portion of the balloon catheter is connected to the connector and the inner tube, and the connector and the outer tube.

  In the present invention, the balloon resin material is polyethylene terephthalate (PET), polyethylene, polyvinyl acetate, ionomer, polyvinyl chloride, polyamide (nylon 66, nylon 12, etc.), polyamide thermoplastic elastomer, polyester thermoplastic elastomer, and polyurethane. One type or a mixture of two or more types of thermoplastic elastomers can be used, and a layered material combining these resin materials can be used, but it can be welded or bonded to the outer tube and the inner tube. It is preferable to select one.

  The distal taper and the proximal taper of the balloon can be thinned by a laser or the like during the blow molding process and the assembling process, and various methods can be used for producing the thin film. It does not limit the effect.

The present invention, wall thickness T _D of the wall thickness T _C and the position D at the position C shown in FIG. 1
T _C <T _D related to balloon catheter balloons,
Preferably, T _C / T _D ≧ 1.07, and more preferably T _C / T _D ≧ 1.15.
Also, the thicknesses T _E , T _B , T _F , T _{A at} the positions E, B, F, _A are
It is preferable that T _E / T _B ≧ 1.00 and T _F / T _A ≧ 1.00 in order to improve the insertability to the proximal end of the balloon, which is the effect of the present invention, and to prevent slipping.

  As shown in FIG. 4, the balloon of the present invention can fold a cylindrical balloon into the shape of 3 to 5 blades or more, and wrap the blades around the inner tube. be able to.

  The balloon surface and the outer surface of the outer tube of the present invention are preferably subjected to a treatment for enhancing lubricity, and hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyacrylamide, and polyvinylpyrrolidone may be used. However, the type of hydrophilic coating does not limit the effect of the present invention, and the processing method is not limited.

  Examples of the balloon catheter equipped with the balloon of the present invention will be described below, but the present invention is not limited to the following examples.

(Production method of balloon)
A nylon tube (Arkema: trade name Rilsan A) was used to produce a balloon tube by extrusion. The tube was heated in a mold and pre-blowed to form a balloon shape. The resulting balloon was placed in a stretching apparatus as shown in FIG. As shown in Fig. 5-B, crimping is carried out, and while cooling, hot air is blown to the proximal or distal taper portion of the balloon by a heating nozzle, and stretched left and right as shown in Fig. 5-C. did. The balloon of the present invention was obtained by placing the balloon in a molding die and performing heat molding.

(Production method of balloon catheter)
Inside the balloon of the present invention produced above, an inner tube having an outer diameter of 0.56 mm having a lumen for passing a guide wire is passed, and the balloon is concentric with the inner tube at one end in the distal direction. And the other end of the balloon, the proximal end, connects to the outer tube having a lumen for introducing pressure into the balloon, and the space is introduced by the inner surface of the outer tube and the outer surface of the inner tube to introduce pressure. A space was formed. Two ring markers having X-ray contrast properties were provided on the outer surface of the inner tube arranged in the balloon, and arranged so as to represent the cylindrical and conical boundary of the balloon as shown in FIG. The proximal proximal portion, including the connector connection, connected the connector and inner tube and the connector and outer tube.

  Perform hydrophilic treatment on the assembled balloon catheter, fold the balloon into a three-blade shape as shown in Fig. 4, wrap it around the inner tube, and cover the balloon with a protective tube with an inner diameter of φ0.86mm from the distal side. Then, sterilization with ethylene oxide was performed to complete the production of the balloon catheter.

(Test method)
The balloon catheter test method will be described below.

Thickness measurement of the balloon taper laser displacement meter (Keyence Corporation: LT-8010) in position A to 4 equally divided proximal tapered portion illustrated in FIG. 1, B, thickness in C T _A, T _B, The wall thicknesses T _D , T _E , and T _F at positions D, E, and F on the _TC and the distal taper were measured.

  For insertion, a measurement system as shown in FIG. 6 is submerged in 37 ° C. water, and a simulated stenotic lesion with an inner diameter of 0.75 mm is placed in a simulated blood vessel plate. The insertability was determined. For the simulated stenotic lesion, a polyethylene stenosis tube is used, and the determination of insertion is ◎ if it can be inserted from the catheter tip to the proximal end of the proximal taper, and if it can be inserted partway to the proximal taper, If it can be inserted from 3/4 to 4/4 of the cylindrical part, △ if it is inserted from 2/4 to 3/4 of the cylindrical part, and if it is inserted less than 1/2 of the cylindrical part X.

(Examples 1-5)
Of the balloon production methods shown above, the drawing position shown in FIG. 5 is changed to change the drawing position of the balloon with the wall thickness shown in Table 1 and the outer diameter of the tubular portion of Φ3.0 mm and the total length of the balloon of 21 mm. The balloon catheter was assembled by the above-described catheter manufacturing method and evaluated by the above test method.

(Comparative Examples 1-3)
Among the balloon production methods shown above, the drawing position shown in FIG. 5 was changed to produce a balloon having the wall thickness shown in Table 1 with a cylindrical part outer diameter of Φ3.0 mm and a balloon total length of 21 mm. Then, a balloon catheter was assembled by the catheter production method described above and evaluated by the test method.

(Comparative Example 4)
A balloon having the thickness shown in Table 1 and a cylindrical part outer diameter of Φ3.0 mm and a balloon total length of 21 mm was prepared by the above-described balloon manufacturing method without stretching by the stretching apparatus shown in FIG. A balloon catheter was assembled by the catheter production method shown and evaluated by the above test method.

(Comparative Example 5)
By stretching the distal taper with the stretching device shown in FIG.
A balloon having a wall thickness of Φ3.0 mm and a balloon total length of 21 mm was prepared, a balloon catheter was assembled by the catheter preparation method described above, and evaluation was performed by the test method described above.
The test results are shown in Table 1.

(Test results)
In Example 1, insertion was possible from the catheter tip to the proximal end of the proximal taper.
In Example 2, insertion was possible up to the middle of the proximal taper.
In Examples 3 to 5, 3/4 to 4/4 of the cylindrical portion could be inserted.
In Comparative Example 1, it was possible to insert from 2/4 to 3/4 of the entire cylindrical portion.
In Comparative Examples 2 to 4, it was possible to insert only up to 1/2 of the cylindrical portion from the distal end of the catheter.
By thinning than the thickness T _D in the above that the thinning than the distal side tapered proximal side taper of the balloon from the results, in particular the position C definitive thickness T _C the position D in FIG. 1, the balloon It was confirmed that the difference in the balloon profile between the distal side and the proximal side was reduced to greatly improve the insertability.

  The balloon according to the present invention can reduce the taper without impairing the thickness of the upper part of the cylinder, and therefore has a pressure resistance equivalent to that of the balloon that does not reduce the taper. In addition, since the proximal taper is thinned, the resistance when the balloon catheter was removed from the body after dilatation was small.

It is a schematic diagram which shows the positional relationship which measures the balloon thickness concerning this invention. It is a schematic diagram explaining the slipping of a balloon catheter. It is a schematic diagram which shows an example of the balloon catheter in this invention. It is a schematic diagram which shows an example of the folding shape of the balloon catheter in this invention. It is a schematic diagram which shows the method of thinning a balloon taper. It is a schematic diagram which shows the test system of the balloon catheter in an Example.

Explanation of symbols

11 Balloon 21 Stenotic lesion 22 Balloon catheter 23 Balloon 24 Balloon (expanding)
25 Balloon (expanded)
31 balloon 32 inner tube 33 proximal ring marker 34 distal ring marker 35 outer tube 36 connector 41 balloon 42 inner tube 43 three-blade shape 44 four-blade shape 45 five-blade shape 51 balloon 52 crimp base (upper jaw)
53 Coolant flow path (upper jaw)
54 Crimp table (mandible)
55 Coolant flow path (mandible)
56 Hot Air Nozzle 57 Crimped Balloon 58 Stretched Balloon 61 Guide Catheter 62 Simulated Blood Vessel Plate 63 Polyethylene Stenosis Tube

Claims (4)

A cylindrical portion having a substantially uniform thickness, a distal tapered portion and a proximal tapered portion adjacent to both ends of the cylindrical portion, and a distal sleeve portion and a proximal side adjacent to the tapered portion, respectively. A balloon for a balloon catheter composed of a sleeve portion, wherein the outer diameter of the distal sleeve is smaller than the outer diameter of the proximal sleeve and the proximal taper is divided into four equal positions A, B, and C. Distances L _D , L _E from the distal tubular end of D, E, F, with distances L _A , L _B , L _C located on the distal taper , L _F
L _A = L _F , L _B = L _E , L _C = L _D
The thickness TC at position _C and the thickness TD at position _D are
T _C <T _D
Balloon for balloon catheters in the relationship. The thickness T _E at position _E and the thickness T _{B at} position _B are T _E ≧ T _B ,
The balloon according to claim 1, wherein the thickness T _F at the position _F and the thickness T _{A at the} position A are in a relationship of T _F ≧ T _A. Thickness T _C at position C, the thickness T _A of the thickness T _B and the position A at position B is,
T _C > T _B ≧ T _A
The balloon according to claim 1 or 2, wherein   A balloon catheter equipped with the balloon according to claim 1.