JP3508416B2 - Dilatation catheter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dilatation catheter used in a surgical operation for dilation, and more particularly to a vasodilation catheter.

[0002]

Dilatation catheters are mainly used for angioplasty treatment of stenotic or occluded blood vessels. As shown in FIG. 1 showing the present invention, a dilatation catheter, which is generally called an over-the-wire system, is a dilatation catheter that supplies pressure fluid to the distal end of a tubular catheter shaft having a plurality of lumens therein. It has a structure in which a balloon communicating with the working lumen is provided and an adapter having a port communicating with each lumen is connected to the proximal end portion, and in a normal state, the balloon is folded with respect to the catheter shaft. Then, in this treatment, the balloon portion of the dilatation catheter is inserted through the artery of the patient into the stenosis site, where it is expanded by introducing pressure fluid into the balloon,
Expand the stenosis or obstruction.

The dilatation catheter is mainly inserted into the body passage to be treated, and the dilatation treatment is performed by introducing the internal pressure at the treatment site. Therefore, the pressure required for dilatation is introduced as the required functional property. It should have sufficient strength to prevent the balloon from breaking during this process and be safely controllable to the desired expansion size. In addition, since the body passage is often bent, the distal end of the dilatation catheter is particularly flexible so that it can follow the bent body passage, and the hand portion has a property of transmitting force to the tip. Some strength is required to be good. In addition, since it is usually used by passing a guide wire inside, it is one of the important properties that there is little friction with the guide wire.

In terms of safety, the catheter itself is in contact with internal tissues and blood for a long time, and the contrast agent, drug, etc. that have passed through the inside of the catheter are injected into the body. Safety is required. Furthermore, it is desirable to have a structure that prevents them from the risk of breakage or falling off during use.

Materials used or proposed for dilatation catheters are polyethylene terephthalate, polyethylene, polyvinyl acetate, ionomers, polyvinyl chloride, polyamides, polyamide elastomers, polycarbonates, polydimethylsiloxanes,
Polyimide, polyarylate, polysulfone, polypropylene, etc. are also used. In particular, as a material for the adapter part, polycarbonate is used for most dilatation catheters because of its strength and dimensional stability. In some cases, polyamide was used as the material for the adapter part.

Although the above-mentioned raw materials have a track record for medical devices including catheters, caution has been required when applied to dilatation catheters. That is, ethylene oxide gas (hereinafter abbreviated as EOG) is used to sterilize the dilatation catheter.
Is most frequently used, but there is a problem that the EOG does not escape easily depending on the material and there is a large amount of residual EOG in the dilatation catheter. Disorders due to residual EOG are well-known such as irritation to skin and mucous membranes, hemolysis, etc., but the permissible value thereof has not been officially determined at present. However, 25 ppm or less of substances that are in contact with blood or tissues for a long time are considered to be safe. Conventional EOG sterilized commercially available dilatation catheters have residual EOG depending on the time elapsed from the sterilization date.
Exists in the order of several ppm to several tens of ppm,
It turned out that the EOG was not completely removed.

Further, the dilatation catheter is generally composed of members such as a balloon, a plurality of tubes and adapters, and the above materials are applied to the respective members. The respective constituent members are assembled to form a catheter. However, in order to prevent damage and dropout of the dilatation catheter and ensure safety, the joint between the members must be highly reliable. A heat welding method and an adhesive agent are often used for the joining method. Especially, it is difficult to use the heat welding method for joining different kinds of materials, and thus the adhesive agent is frequently used. However, cyanoacrylate-based, epoxy-based, and urethane-based adhesives that are often used for medical devices are susceptible to changes over time in adhesiveness due to factors such as the influence of water and the progress of reactions. There is a drawback that it is difficult to control the catheter assembly process due to the long curing time of the agent.

[0008]

In view of the above situation, the present invention is to solve the problem E which has been a conventional problem.
An object of the present invention is to provide a dilatation catheter in which the residual EOG in the dilatation catheter after OG sterilization is reduced and the risk of breakage or drop during use is reduced.

[0009]

[Means for Solving the Problems] First, the present inventors screened and extracted various materials from the viewpoint of ease of EOG removal. Therefore, the properties required for the dilatation catheter as described above for the material selected, strength, operability, low friction for the tube member, strength, dimensional stability, etc. for the adapter member, and avoiding the danger that may occur during operation As a result of earnest research with due consideration, the present invention has been achieved.

The dilatation catheter according to the present invention is a dilatation catheter composed of a plurality of tubular members and an adapter member connected to the tubular members, wherein the main material of the tubular member is polyethylene and the material of the adapter member is polymethylpentene. It is a dilatation catheter characterized in that

Further, a plurality of tube-shaped members made of polyethylene are joined concentrically in multiple layers from the tip portion to the proximal portion to form a catheter shaft, and the tip portion of the dilatation catheter has a good followability with respect to the passage in the bent body. As described above, flexibility is imparted to the proximal portion, and a certain amount of strength is imparted to the proximal portion so that the force transmission to the distal end is good.

[0012]

The dilatation catheter according to the present invention has a proven record of use in medical applications where the main constituent material is chemically stable compared to other polymer materials such as polyethylene or polymethylpentene and has little effect on the living body. Since there are materials that are used, there are substances that are thought to adversely affect the living body,
There is no possibility of occurrence, and the residual EOG when using EOG in the sterilization method is extremely small, so it is a catheter with extremely high biological safety, and since the balloon is integrally molded from the tube, Further, since the distal end tube of the dilatation catheter is heat-welded to the tube at the proximal end, the risk of dropping out during use is reduced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the dilatation catheter of the present invention will be further described with reference to FIGS. The dilatation catheter of the present invention has a tubular member 1 made of polyethylene and a balloon 1A integrally formed from one end of the tubular member, and the tubular member 1 has a relatively higher tensile elastic modulus than the tubular member 1. Is joined concentrically with the tubular member 2 made of polyethylene, and the tubular member 3 made of polyethylene is arranged inside the tubular members 1 and 2, and the tubular member 3 is a balloon of the tubular member 1. 1A is joined concentrically with the tubular member 1 at the molded end, and a gold or platinum annular member 1B for X-ray imaging is fixed on the tubular member 3 at a position overlapping with the balloon 1A. And
The inner lumen of the tubular member 3 communicates with the port 10 of the adapter made of polymethylpentene, and the inner lumens of the tubular members 1 and 2 and the outer lumen of the tubular member 3 communicate with the port 11 of the adapter. It is a structure.

Further, the tubular member 2 of the catheter
And a portion 4A that is flared into a conical shape after superposing a polyethylene tubular member 4 having an inner diameter larger than the outer diameter of the tubular member 2 on one end that is not joined to the tubular member 1. Flare portion 5A of polyethylene tubular member 5 having a flared end
The overlapped part is clamped and fixed by tightening the screws of the main body 6 of the adapter made of polymethylpentene and the adapter cap 7 made of polymethylpentene,
The adapter body 6 and the cap 7 are connected by ultrasonic welding. Further, the inner diameter and the outer diameter of the tubular member 3 are continuously integrally formed so that the side joined to the tubular member 1 is smaller than the inner diameter and the outer diameter of the other end. Further, a portion 8A in which a polyethylene tubular member 8 having an inner diameter larger than the outer diameter of the tubular member 3 is superposed and joined to one end not joined to the tubular member 1 and then flared into a conical shape Is fastened by tightening the screws of the adapter body 6 and the adapter cap 9 made of polymethylpentene.
And the cap 9 are connected by ultrasonic welding.

As described above, the catheter shaft of the dilatation catheter of the present invention has a structure in which the number of laminated tubular members is increased from the distal end portion having the balun 1A to the proximal portion to which the adapter 6 is connected. That is, the tip portion is a two-layer concentric structure portion of the tubular members 1 and 3, and the tubular members 2, 4, and 5 are sequentially laminated from there to the proximal portion to form a three-layer concentric structure portion and a four-layer concentric structure portion. Section, five-layer concentric structure section. As a result, the distal end of the dilatation catheter is flexible and has good conformability to the passage in the bent body, and the proximal part has high bending strength and compressive strength, so that the force transmission to the distal end is good. ing.

[0017]

Examples The following examples show examples of dilatation catheters made according to the present invention, and comparative examples show comparative catheters made by conventional methods and materials, and the superiority of the present invention compared with commercially available dilatation catheters. The characteristics will be described.

(Example) Density 0.959 g / cm ³ , melting point 132 ° C., melt flow rate (hereinafter abbreviated as MFR)
0.7g / 10min polyethylene and density 0.918g /
cm ³ , melting point 107 ° C., MFR 0.3 g / 10 min polyethylene and density 0.930 g / cm ³ , melting point 117 ° C.,
MFR 1.5 g / 10 min polyethylene in a weight ratio of 3:
A mixture having a ratio of 2.5: 4.5 is extruded by an extruder, and has a diameter and wall thickness suitable for forming a balloon (inner diameter: about 0.7 mm, outer diameter: 0.9 mm to 1.2 mm). Was molded into a tube. Furthermore, the tube was irradiated with an electron dose appropriate for forming a balloon into a balloon by an electron beam irradiation device to introduce crosslinking. The tube was placed in a mold, heated and stretched in the axial direction, and then a pressure fluid was introduced into the mold to blow-mold it into a balloon shape. The tube containing the balloon was cut at both ends of the balloon to an appropriate length pre-calculated (Tubular member 1). The axial elastic modulus of the tubular member 1 thus manufactured is about 30.
It was 0 MPa.

Density 0.961 g / cm ³ , melting point 135
C., polyethylene having an MFR of 1.0 g / 10 min is extruded by an extruder to give an inner diameter of about 0.95 mm and an outer diameter of about 1.2.
It was molded into a mm tube. The tube was placed in a clean oven so that a tension of about 0.1 N was applied in the axial direction of the tube, heat-treated at 120 ° C. for 2 hours, and then cut into an appropriate length calculated in advance (tube shape). Member 2). The tensile elastic modulus in the axial direction of the tubular member 2 thus manufactured was about 800 MPa. A stainless steel core material was placed at the end of the tubular member 2 to have a density of 0.930 g / cm ³ , a melting point of 117 ° C., and an MFR of 1.5.
g / 10 min of polyethylene was extruded by an extruder so that the inner diameter was made larger than the outer diameter of the tubular member 2, and a tube (tube-shaped member 4) cut into a cut length calculated in advance was covered, Further, a silicon outer peripheral holding material was covered thereon, and the core material was heated by an electromagnetic induction heating device to heat-weld both polyethylene tubes. The welded portion was pressed against a heated flare mold to form flare portions 2A and 4A.

Density 0.959 g / cm ³ , melting point 132
The tubular member 5 extruded so that the inner diameter of polyethylene having a MFR of 0.7 g / 10 min and the outer diameter of the tubular member 4 was cut to an appropriate length calculated in advance, and its end was heated. The flare portion 5A was formed by pressing it against the flare mold. Tubular members 2 and 4
The flared portions 2A, 4A and the flared portion 5A of the tubular member 5 are overlapped,
MFR 26g / 10min, Olsen rigidity 6000kg / c
m ^2, Rockwell hardness 60, the adapter body 6 polymethylpentene heat distortion temperature 85 ° C. was prepared by injection molding, MFR22g / 10 min, Olsen stiffness 3900k
g / cm ² , Rockwell hardness 35, heat distortion temperature 80 ° C
The polymethylpentene of (3) was sandwiched by the caps 7 produced by injection molding, and the screws between the main body 6 and the caps 7 were tightened to fix the respective members. Further, after tightening the screws, the cap 7 and the main body 6 were welded using an ultrasonic welding machine.

The end of the tubular member 1 on which the balloon 1A is not formed is inserted into the end of the tubular member 2 opposite to the flare portion 2A, and the core material made of stainless steel is inserted into the overlapping portion of the two. , A silicon outer peripheral protective material was attached to the outside, the core material was heated by an electromagnetic induction heating device, and both members were heat-welded.

Density 0.961 g / cm ³ , melting point 135
After mixing phthalocyanine blue in a weight ratio of 0.3 parts with polyethylene having a MFR of 1.0 g / 10 min,
A relatively small diameter part (inner diameter 0.4
2 mm, outer diameter of about 0.56 mm) and a relatively large-diameter portion that continuously and integrally changed from there (inner diameter of about 0.50 m)
m, outer diameter of about 0.67 mm) was extruded. The tube was placed in a clean oven so that a tension of about 0.05 N was applied in the axial direction of the tube, heat-treated at 80 ° C. for 1 hour, and then cut into an appropriate length calculated in advance (tube shape). Member 3). A stainless steel core material was placed at the end of the tubular member 3 having a relatively large diameter to give a density of 0.930 g / cm ³ and a melting point of 117.
A tube obtained by extruding polyethylene having an MFR of 1.5 g / 10 min at a temperature of MFR of 1.5 g / 10 by an extruder so as to have an inner diameter larger than the outer diameter of the tubular member 3 and cut into a pre-calculated thin length (the tubular member 8 ) Was further covered, and a silicon outer peripheral holding material was further covered thereon, and the core material was heated by an electromagnetic induction heating device to heat-weld both polyethylene tubes. The welded portion was pressed against a heated flare mold to form flare portions 3A and 8A. Further, a stainless core material is inserted on the opposite side of the flared portion 3A of the tubular member 3, a gold annular member 1B is arranged at a pre-calculated position, and a density of 0 is provided on both ends of the annular member 1B. 0.920 g / cm ³ , melting point 129 ° C., MFR 1.6
A tube made by extruding polyethylene of g / 10 min to an inner diameter of about 0.62 mm and an outer diameter of 0.72 mm has a length of about 0.5 mm.
The cut piece is placed and heated by hot air while being pressed by the silicon sheet, the annular member 1B made of gold.
The gold annular member 1B was fixed to the tube-shaped member 3 by melting polyethylene disposed at both ends of the. The gold annular member 1B is fixed, and the tubular member 3 having one end flared is placed through the inside of the adapter body 6 and the tubular members 2 and 1 connected thereto from the unflared side. , Flare parts 3A and 8A are sandwiched between adapter body 6 and MFR 26 g / 10 minutes, Olsen rigidity 10000 kg / cm ² , Rockwell hardness 85, polymethyl pentene having a heat distortion temperature of 90 ° C. and injection molded cap 9 Each member was fixed by tightening the screw between 6 and the cap 9. Further, after tightening the screws, the cap 9 and the main body 6 were welded using an ultrasonic welding machine.

After the above-mentioned assembly, the overlapping portion of the ends of the tubular member 3 and the tubular member 1 is heated with hot air in a state where the core material is penetrated from the cap 9 through the inside of the tubular member 3. The heating part was pulled toward both ends to substantially reduce the diameters of both tubular members 1 and 3 and weld them concentrically. Further, the welded portion was cut into a predetermined length, and the tip end portion was polished with a wrapping film sheet so as to further reduce the diameter.

After coating polydimethylsiloxane dissolved in hexane on the inside of the tubular member 3, polydimethylsiloxane is coated by a method of evaporating hexane, and the tubular member 1 portion including the balloon 1A is coated with polydimethylsiloxane. Coating was done by direct application of siloxane.

The balloon 1A is folded around the tubular member 3 and inserted into the polyethylene tube having an inner diameter slightly larger than the folded diameter while maintaining its shape, and only the folded balloon portion is approx. 65 degreeC-70 degreeC was heated for about 10 minutes, and it was made to have a crease. The heating temperature is set to about 65 ° C. to 70 ° C. because the optimum heating temperature differs depending on the size of the balun portion.

The dilatation catheter of the present invention produced as described above was assembled by heat welding between the constituent members without using an adhesive for joining and fixing the members constituting the same. In particular, in fixing the tube by tightening the screw of the adapter portion, as shown in the examples, caps having different hardness were used for the adapter body so that good tightening performance was obtained. The dilatation catheter according to the above embodiment has a tubular member 1 having a relatively small tensile elastic modulus in the vicinity of the balloon.
Since the tubular member 2 having a relatively large tensile elastic modulus is provided in the vicinity of the adaptor, the dilatation catheter is relatively excellent in operability, and the force at hand is easily transmitted from the adaptor to the balloon. In addition, the tubular member 3 through which the guide wire 1 passes during use has a relatively large inner diameter in the vicinity of the adapter, and at the same time, since it is coated with polydimethylsiloxane, friction with the guide wire is reduced. It was a dilatation catheter with excellent operability.

(Comparative Example) Residue after EOG sterilization for the dilatation catheter according to the present invention, as a comparative example, a material composition typical of commercially available dilatation catheters, a catheter made using an adhesive and a commercially available dilatation catheter EOG
The amount was evaluated. The following three examples are shown as comparative examples. Comparative Example 1 is composed of a polyethylene tube of the same size as the present invention and a polycarbonate adapter molded by using the same mold, and the tube and the adapter are assembled by using a polyurethane adhesive. It is a dilatation catheter. Comparative Example 2 is a polyamide (nylon 12) tube of the same size as the present invention, a separately molded polyamide (nylon 12) balloon, and a polyamide (nylon 12) adapter molded using the same mold. The dilatation catheter is constructed by using a cyanoacrylate adhesive for bonding the tube and the balloon and a polyurethane adhesive for bonding the adapter. Comparative Example 3 is a commercially available dilatation catheter which is composed of a polyethylene tube and a polycarbonate adapter, and the tube and the adapter are adhered by a polyurethane adhesive containing talc as a filler.

EOG sterilization of the product of the present invention and Comparative Examples 1 and 2 is E
Using a mixed gas of 20% OG and 80% carbon dioxide, gas concentration 600 mg / L, temperature 50 to 60 ° C., humidity 40 to 75
% RH, the pressure was 1 kg / cm ² , the treatment time was 6 hours, and degassing was performed by aeration 5 times. After the treatment, as a degassing period, a product stored at room temperature for 16 days or more was measured. The sterilization condition of the commercial product of Comparative Example 3 and the exact period from the sterilization date were unknown, but it was estimated from the indication of the sterilization month that it was about 4 months. Quantitative determination of residual ethylene oxide was carried out by the quantitative method of residual ethylene oxide of Japan Medical Equipment Association. The measurement results are shown in the table below.

[0029]

[Table 1]

As shown in the table, the dilatation catheter according to the present invention had the smallest amount of residual EOG despite the shortest period from completion of sterilization to measurement. This result shows a part of the above-mentioned excellent safety of the present invention.

[0031]

INDUSTRIAL APPLICABILITY The dilatation catheter according to the present invention is chemically stable as compared with other polymer materials whose main constituent materials are polyethylene and polymethylpentene, and has a proven record of use in medical applications with less influence on the living body. When EOG is used for the sterilization method, since there is no possibility that a substance that may adversely affect the living body exists and does not occur because the established material is used and no adhesive is used for joining the members. The biological safety is extremely high because the residual EOG of is extremely small.

[Brief description of drawings]

FIG. 1 is a partially omitted side view showing the entire dilatation catheter of the present invention.

FIG. 2 is a partial cross-sectional view showing a joint portion between a tube portion and an adapter portion of the dilatation catheter of the present invention.

[Explanation of symbols]

1 tubular member 2 tubular members 3 tubular members 4 tubular members 5 tubular members 6 Adapter body 7 Adapter cap 8 tubular members 9 Adapter cap 10 ports 11 ports

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-16053 (JP, A) JP-A-6-15004 (JP, A) JP-A-6-343691 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61L 29/00-29/18 A61M 25/00-25/18

Claims (3)

(57) [Claims] 1. A dilatation catheter composed of a plurality of tubular members and an adapter member connected to the tubular members, wherein the main material of the tubular member is polyethylene and the material of the adapter member is polymethylpentene. Dilated catheter. 2. A tubular member (1) made of polyethylene and a balloon (1A) integrally formed from one end of the tubular member, the tubular member (1) having a relatively higher tensile elastic modulus than the tubular member (1). It is concentrically joined to the polyethylene tubular member 2, and a polyethylene tubular member 3 is arranged inside the tubular members 1 and 2, and the tubular member 3 is a balloon 1A of the tubular member 1. Is joined concentrically with the tubular member 1 at the molded end, and a gold or platinum annular member 1B for X-ray imaging is fixed on the tubular member 3 at a position overlapping with the balloon 1A. The inner lumen of the tubular member 3 is in communication with the port 10 of the adapter made of polymethylpentene, and the inner lumen of the tubular members 1 and 2 is The dilatation catheter according to claim 1, wherein the outer lumen of the tube-shaped member (3) communicates with the port (11) of the adapter. 3. A polyethylene tubular member 4 having an inner diameter larger than the outer diameter of the tubular member 2 is superposed and joined to one end of the tubular member 2 of the catheter which is not joined to the tubular member 1. After that, the conical flared portion and the flared portion of the polyethylene tubular member 5 having the flared end are overlapped to form a polymethylpentene adapter body 6 and a polymethylpentene adapter. Tighten the screw of the cap 7 to fix it, and connect the adapter body 6 and the cap 7 by ultrasonic welding.
The tubular member 3 is continuously and integrally molded so that the inner diameter and outer diameter of the tubular member 3 are smaller than the inner diameter and outer diameter of the other end. At one end, a tubular member 8 made of polyethylene having an inner diameter larger than the outer diameter of the tubular member 3 is superposed and joined, and a conical flare portion is formed on the adapter body 6 and an adapter made of polymethylpentene. 3. The expansion catheter according to claim 1, wherein the cap 9 is sandwiched and fixed by tightening the screw, and the adapter body 6 and the cap 9 are connected by ultrasonic welding.