JP2023029001A - balloon catheter - Google Patents

Abstract

To provide a balloon catheter that has ameliorated uneven inflation of a balloon.SOLUTION: A balloon catheter 10 includes a catheter shaft 13 and a balloon 14. The balloon 14 includes a rib part 18 consisting of a plurality of ribs 17a, 17b, and 17c on the inner wall 14a. The rib part 18 includes a central part A and two end parts B and C with different rib intervals Pa, Pb, and Pc in an axial direction Y of the catheter shaft 13. The rib intervals Pb and Pc of the two end parts B and C are smaller than the rib interval Pa of the central part A.SELECTED DRAWING: Figure 2

Description

The present invention relates to balloon catheters.

2. Description of the Related Art A medical balloon catheter is known which is inserted into a patient's body to perform medical treatment. This medical balloon catheter is used to inject or administer drug solutions to patients, remove blood clots, excrete body fluids such as urine, or use physiological saline solution by indwelling the balloon in or near the affected area of a patient and expanding and contracting the balloon. is injected.

After a balloon catheter is inserted into a patient's body, the balloon is inflated by inflowing air, physiological saline, or the like. However, since the catheter shaft and the balloon are made of silicone rubber, a phenomenon that the balloon and the catheter shaft stick to each other during deflation, that is, blocking, may occur, resulting in poor expansion. Therefore, in order to prevent blocking, Patent Documents 1 and 2 disclose balloon catheters in which ribs are provided on the inner wall of the balloon.

JP 2004-041349 A JP 2009-225997 A

On the other hand, the wall thickness of the balloon is very thin, and when it is expanded, it may not inflate uniformly around the catheter shaft (hereinafter referred to as unilateral inflation, eccentricity, etc.). And we are anxious about blocking increasing such a one-sided bulge. If one-sided swelling occurs, the catheter cannot be satisfactorily indwelled in the body, and particularly in the case of a Foley catheter, there are problems such as leakage of urine and unintentional withdrawal of the catheter. For these reasons, there is a demand for further improvement of the uneven inflation of the balloon.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a balloon catheter in which partial swelling of a balloon is improved.

As a result of intensive studies, the present inventors have found that by arranging the ribs on the inner wall of the balloon in a specific arrangement, it is possible to improve the one-sided inflation of the balloon, and have completed the present invention.
That is, the present invention is a balloon catheter comprising a catheter shaft and a balloon, wherein the balloon has a rib portion composed of a plurality of ribs provided in the circumferential direction on the inner wall of the balloon, and the rib portion is the catheter shaft. The balloon catheter has a center portion and both end portions with different rib spacing in the axial direction of the balloon catheter, wherein the rib spacing at both end portions is smaller than the rib spacing at the center portion.

Preferably, the rib spacing at the central portion is greater than 1.5 mm and the rib spacing at both ends is 1.5 mm or less.

The total length of both ends is preferably 15% or more and 65% or less of the length of the rib portion in the axial direction of the catheter shaft.

The rib spacing at the ends may decrease towards the ends of the balloon.

The width of the plurality of ribs is preferably 0.05 mm or more and 0.50 mm or less.

The height of the plurality of ribs is preferably 0.05 mm or more and 0.50 mm or less.

The tensile strength of the balloon is preferably 7.0 MPa or more.

The tensile elongation of the balloon is preferably 600% or more.

The A hardness of the balloon is preferably 20 or more and 50 or less.

The permanent tensile strain of the balloon is preferably 0.5% or more.

ADVANTAGE OF THE INVENTION According to this invention, the balloon catheter with which the one-sided swelling of the balloon was improved can be provided.

1 is a schematic diagram showing one embodiment of a balloon catheter of the present invention; FIG. Fig. 2 is a cross-sectional view of the balloon in the axial direction of the catheter shaft; FIG. 4 is an enlarged cross-sectional view of the rib in the axial direction of the catheter shaft;

[Balloon catheter]
The balloon catheter 10 of the present invention comprises a handle portion 11, a hub 12, a catheter shaft 13 and a balloon 14, as shown in FIG. The distal end of the catheter shaft 13 is provided with a distal end sealing portion 15 for smooth insertion of the balloon catheter 10 into the patient. The catheter shaft 13, the balloon 14, and the tip end sealing portion 15 are made of silicone rubber, for example.
After the balloon 14 has been inserted into the catheter shaft 13, it is joined to the catheter shaft 13 with an adhesive at joints 16a and 16b. Also, the distal end sealing portion 15 is adhered to the distal end of the catheter shaft 13 with an adhesive.

[Catheter shaft]
Catheter shaft 13 has a first lumen (not shown) and a second lumen (not shown). The first lumen is an internal conducting hole for sending and discharging fluids such as physiological saline, sterilized purified water, air, and solid objects such as guide wires. The second lumen is a medium for forming the balloon, such as physiological It is an internal communication hole for sending out saline solution, sterilized purified water, air, and the like.

Further, the side surface of the catheter shaft 13 may be provided with a contrast portion in which a contrast agent is linearly blended along the axial direction Y. As shown in FIG. As the contrast medium, a known one can be used, and examples thereof include barium sulfate, titanium oxide, and the like. As a contrast medium, one type may be used alone, or two or more types may be used in combination.

The hub 12 is joined to a catheter shaft 13, the first lumen of the catheter shaft 13 is connected to a cylinder or the like that supplies solids, etc., and the second lumen of the catheter shaft 13 is a pressure applying device (such as an inflator) that supplies a high-pressure fluid. not shown).
The hardness of the silicone tube of the catheter shaft 13 is JIS K 6253-3 hardness, and from the viewpoint of reducing the burden on the patient, it is preferably A30 or more and A80 or less, more preferably A40 or more and A70 or less.

The catheter shaft 13 can be produced by extrusion molding and vulcanization using an addition cure millable silicone rubber composition. The addition-curable millable silicone rubber composition may contain additives. Additives include, for example, fillers, auxiliaries (chain extenders, cross-linking agents, etc.), catalysts, dispersants, foaming agents, anti-aging agents, antioxidants, pigments, coloring agents, processing aids, softening agents, Plasticizers, emulsifiers, heat resistance improvers, flame retardant improvers, acid acceptors, heat conductivity improvers, release agents, solvents and the like.

(balloon)
FIG. 2 shows a cross-sectional view of the balloon 14 in the axial direction Y of the catheter shaft 13, and FIG. 3 shows an enlarged cross-sectional view of the ribs. Although FIG. 3 illustrates the rib 17a in the central portion A, the same applies to the lower end portion B and the upper end portion C as well.
As shown in FIG. 2, the balloon 14 has a rib portion 18 made up of a plurality of ribs (17a, 17b, 17c) provided on the inner wall 14a of the balloon 14 in the circumferential direction. The rib portion 18 has a central portion A and both end portions (B, C) in the axial direction Y of the catheter shaft 13 with different rib intervals (Pa, Pb, Pc).
Hereinafter, with respect to both ends, the end on the tip side (the direction indicated by the downward arrow in the figure) is referred to as lower end B, and the handle portion 11 side is referred to as upper end C. As shown in FIG. In the present invention, the lower end portion B and the upper end portion C are formed with ribs having the same shape and spacing.

Here, the central portion A, the lower end portion B, and the upper end portion C are divided by boundary ribs with varying rib intervals.
Also, balloon 14 indicates a region including rib portion 18 and joint portions 16a and 16b. Balloon 14 is joined to catheter shaft 13 at joints 16a and 16b. The length L ₁₈ of the rib portion 18 is preferably 35% or more and 85% or less of the length L ₁₄ of the balloon 14 .

In the balloon catheter 10 of the present invention, the rib spacing (Pb, Pc) at the lower end portion B and the upper end portion C is smaller than the rib spacing Pa at the central portion A. Since the rib spacing (Pb, Pc) of the lower end portion B and the upper end portion C is smaller than the rib spacing Pa of the central portion A, when air or the like is injected into the balloon 14, the lower end portion B and the upper end portion C Since excessive swelling can be prevented, uneven swelling can be improved.

The thickness T of the balloon 14 is preferably 0.2 mm or more and 0.9 mm or less. With a thickness of 0.2 mm or more, sufficient durability can be obtained without bursting when the balloon 14 is inflated. Moreover, since the length is 0.9 mm or less, the balloon 14 can be expanded easily and quickly.

The outer diameter D of the balloon 14 is generally preferably 1.40 mm or more and 11.5 mm or less.

The rib spacing Pa of the central portion A is preferably 1.0 mm or more and 5.0 mm or less. More preferably, the rib intervals Pb and Pc of the lower end portion B and the upper end portion C are 0.5 mm or more and 4.0 mm or less, respectively. By setting the rib spacing Pa at the central portion A and the rib spacings Pb and Pc at the lower end portion B and the upper end portion C within the above numerical ranges, blocking can be satisfactorily prevented and the balloon 14 can be uniformly inflated. . In this embodiment, the area excluding the joints 16a and 16b, that is, the entire rib portion 18 is the expanded portion.

The length of both ends, that is, the total length of the length Lb of the lower end portion B and the length Lc of the upper end portion C is set to It is preferably 10% or more and 80% or less, more preferably 10% or more and 60% or less, of the length L ₁₈ of Y (see FIG. 2). The total length of the length Lb of the lower end portion B and the length Lc of the upper end portion C can prevent excessive bulging of the lower end portion B and the upper end portion C, and can expand uniformly.
On the other hand, the length La of the central portion A is preferably 10% or more and 70% or less, more preferably 10% or more and 40% or less, of the length _L18 of the rib portion 18 in the axial direction Y of the catheter shaft 13. is more preferable.

The rib spacings Pb and Pc of the lower end portion B and the upper end portion C may decrease toward both ends. For example, it may gradually decrease to 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, and 1.0 mm toward both ends. This numerical value is an example, and may be smaller than the rib interval Pa of the central portion A, and is not limited to this.

Widths Wa, Wb, and Wc of the plurality of ribs 17a, 17b, and 17c are preferably 0.05 mm or more and 0.5 mm or less, respectively. When the widths Wa, Wb, and Wc of the ribs are 0.05 mm or more, the ribs can be well formed by a mold, and when they are 0.5 mm or less, the balloon 14 can be easily removed from the catheter shaft 13. can be released from the mold.

The heights (Ha, Hb, Hc, see FIG. 3) of the plurality of ribs 17a, 17b and 17c are preferably 0.5 mm or less. By setting the heights (Ha, Hb, Hc) of the plurality of ribs 17a, 17b, and 17c to be 0.5 mm or less, pain during insertion felt by the patient due to unevenness of the rib portion 18 can be reduced, and The release of the balloon 14 from the catheter shaft 13 can be improved.

It is preferable that the top portions of the plurality of ribs 17a, 17b, and 17c have radii Ra, Rb, and Rc of 0.05 mm or more and 0.50 mm or less, respectively. When the radii Ra, Rb, and Rc are 0.05 mm or more, molding by a mold can be performed satisfactorily, and when they are 0.50 mm or less, the balloon 14 can be satisfactorily released from the catheter shaft 13. be able to.

The tensile strength of the balloon 14 is preferably 7.0 Mpa or more. Tensile strength can be measured with a tensile tester. When the tensile strength of the balloon 14 is 7.0 Mpa or more, it is a measure against burst.

The tensile elongation of the balloon 14 is preferably 600% or more. Tensile elongation can be measured with a tensile tester. When the tensile elongation of the balloon 14 is 600% or more, it becomes a leak countermeasure.

The A hardness of the balloon 14 is preferably 20 or more and 50 or less. Hardness can be measured with a hardness meter. When the A hardness of the balloon 14 is 20 or more, burst can be prevented.

The tensile set of balloon 14 is preferably 0.5% or less. A permanent tensile strain can be measured with a permanent tensile strain machine. When the tensile permanent strain of the balloon 14 is 0.5% or less, deformation is prevented.

Since the joints 16a and 16b are portions that are adhered to the catheter shaft 13 with an adhesive, the joints 16a and 16b are not provided with the ribs 17b and 17c, respectively. may

The balloon 14 can be produced by mold molding using the addition curing millable silicone rubber composition used for the catheter shaft 13 .

The balloon catheter of the present invention can be preferably used as a medical balloon catheter, and particularly preferably as a catheter for indwelling in the bladder and a balloon catheter for drug solution administration.

Although the present invention has been described using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the above-described embodiments, and various changes or improvements can be made to the above-described embodiments. It is clear to those skilled in the art that it is possible. In addition, it is clear from the description of the scope of the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

Examples of the present invention will be described below.
[Example 1]
(Fabrication of catheter shaft)
Silicone rubber (trade name “KE-561 (U)”, manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts by mass, vulcanizing agent (trade name “C-19A”, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by mass and 2.0 parts by mass of a vulcanizing agent (trade name “C-19B”, manufactured by Shin-Etsu Chemical Co., Ltd.).
Next, a catheter shaft was produced by extrusion molding using the above silicone rubber composition. A through hole was formed with forceps from the second lumen to the outer wall of the catheter shaft in the area where the balloon was to be formed on the catheter shaft.
The A hardness (hardness scale) of the catheter shaft was 60.

(Preparation of balloon tube)
Silicone rubber (trade name “KE-530 (U)”, manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts by mass, vulcanizing agent (trade name “C-8”, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.0 parts by mass A silicone rubber composition containing was prepared.
A balloon silicone rubber composition was injected into a mold and cured to produce a balloon tube.
The thickness T of the balloon was set to 0.5 mm.

－Rib shape－
The ribs of the balloon were shaped as follows.
(Center)
The rib width Wa was 0.2 mm, the rib spacing Pa was 2.0 mm, the rib height Ha was 0.1 mm, and the radius Ra was 0.1.
The length of the center portion A in the axial direction Y was 12 mm (40% of the length of the rib portion).
(both ends)
The rib widths Wb and Wc are 0.2 mm, the rib spacings Pb and Pc are 1.5 mm, the rib heights Hb and Hc are 0.1 mm, and Rb and Rc are 0.1 mm. 0.1 mm.
The lengths of the lower end portion B and the upper end portion C in the axial direction Y were each 9 mm (30% of the length of the rib portion, and the total length of the lower end portion B and the upper end portion was 60%).

The balloon tube was then inserted into the catheter shaft so that the through hole was covered and glued at the joint.
Finally, a one-liquid room-temperature-curable silicone rubber composition (for example, trade name “KE-41T” manufactured by Shin-Etsu Chemical Co., Ltd.) is used as an adhesive to attach the tip sealing portion to the tip of the catheter shaft. bottom.

[Comparative Example 1]
A balloon catheter was produced in the same manner as in Example 1, except that the rib intervals Pa, Pb and Pc were all set to 2.0 mm.

(Characteristics of balloon)
The balloon properties were measured by the following methods. Table 1 shows the measurement results.

-hardness-
According to the method described in JIS K 6249:2003, the durometer A hardness was measured with a durometer A hardness tester (“GS-719N”, manufactured by TECLOCK).

- Tensile strength and tear strength -
The tensile strength and tear strength were measured in accordance with JIS K6251 using a dumbbell No. 3 as a test piece and using a Tensilon universal material testing machine (trade name "AGS-X" manufactured by Shimadzu Corporation) at a speed of 500 mm / min between chucks. Measured at 60 mm and 20 mm between lines.

-Tensile elongation-
Using a Tensilon universal material testing machine (trade name "AGS-X", manufactured by Shimadzu Corporation), a test piece (25 mm wide, 1.0 mm thick tape) was sandwiched between a pair of chucks separated by 30 mm from each other and fixed. , tensile speed of 500 mm/min, and 20° C., along the longitudinal direction of the test piece.

- Tensile permanent strain -
According to the method described in JIS K 6249:2003, it was measured under 100% elongation test conditions at 180°C for 22 hours.

[evaluation]
The balloon catheters of Examples and Comparative Examples were evaluated as follows. Table 1 shows the evaluation results.

(Balloon expandability)
The balloon was inflated by inflating air and deionized water into the balloon.
When a predetermined amount was injected with respect to the capacity of the balloon, the partial swelling of the balloon was evaluated according to the following criteria.
A: Looking at the outer circumference of the balloon expansion from the outer circumference of the tube, the one-sided swelling is 1:1
B: Viewing the outer circumference of the expanded balloon from the outer circumference of the tube, the unilateral swelling is 1:1.5

(balloon durability)
A balloon durability test was performed according to JIS T 3214:2011. That is, the balloon was inflated with distilled water and the balloon catheter was immersed in artificial urine for 14 days. Thereafter, the distilled water in the balloon was discharged naturally or by suction using a syringe, and the state of the drainage was confirmed.
A: Recovery rate of distilled water is 80% or more B: Recovery rate of distilled water is less than 80%

As shown in Table 1, the balloon catheter of the present invention was found to be excellent in expandability and also in evaluation of durability.

10 Balloon Catheter 11 Handle Part 12 Hub 13 Catheter Shaft 14 Balloon 14a Inner Wall 15 Tip Sealing Part 16a, 16b Joining Part 17a, 17b, 17c Rib 18 Rib Part A Central Part B Lower End C Upper End D Outer Diameter R Radius T Balloon thickness L ₁₄ balloon length L ₁₈ rib part length Ha, Hb, Hc Rib height Wa, Wb, Wc Rib width Pa, Pb, Pc Rib interval

Claims (10)

A balloon catheter comprising a catheter shaft and a balloon,
the balloon has a rib portion formed of a plurality of ribs provided in the circumferential direction on the inner wall of the balloon;
The rib portion has a center portion and both end portions with different rib intervals in the axial direction of the catheter shaft,
A balloon catheter in which the rib spacing at the both end portions is smaller than the rib spacing at the central portion. 2. The balloon catheter of claim 1, wherein the rib spacing at the central portion is greater than 1.5 mm and the rib spacing at the ends is 1.5 mm or less. 3. The balloon catheter according to claim 1, wherein the total length of said both ends is 15% or more and 65% or less of the length of said rib portion in the axial direction of said catheter shaft. 4. The balloon catheter of any one of claims 1-3, wherein the rib spacing at the ends decreases toward the ends of the balloon. 5. The balloon catheter according to any one of claims 1 to 4, wherein the plurality of ribs have a width of 0.05 mm or more and 0.5 mm or less. The balloon catheter according to any one of claims 1 to 5, wherein the plurality of ribs have a height of 0.05 mm or more and 0.5 mm or less. The balloon catheter according to any one of claims 1 to 6, wherein the balloon has a tensile strength of 7.0 MPa or more. 8. The balloon catheter according to any one of claims 1 to 7, wherein the balloon has a tensile elongation of 600% or more. The balloon catheter according to any one of claims 1 to 8, wherein the balloon has an A hardness of 20 or more and 50 or less. 10. The balloon catheter according to any one of claims 1 to 9, wherein said balloon has a tensile set of 0.5% or more.

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