JP6780328B2 - Balloon catheter for stone removal - Google Patents

Description

The present invention relates to a calculus removing balloon catheter used for removing calculus formed in, for example, a bile duct.

There are several known methods for removing stones formed in the bile duct, that is, gallstones, by taking them out of the body, and one of them is a method using a balloon catheter. When removing gallstones from the bile duct using a balloon catheter, first insert the balloon catheter with the balloon in a contracted state into the bile duct through an endoscope, and it is deeper than the position of the gallstone where the balloon should be removed. To be located in. The balloon can then be inflated and then pulled back to allow the balloon to scrape gallstones out of the bile duct.

As a calculus removing balloon catheter used for removing gallstones in this way, for example, one having the structure described in Patent Document 1 is known. In the balloon catheter described in this document, a cylindrical balloon made of an elastic material is joined to the tip (distal end) of the catheter tube, and a fluid is introduced into the balloon to introduce a fluid. Inflate the balloon. Then, in order to suppress the escape of stones and improve the stone removal performance, a fixing tape is attached from above the balloon so that the balloon eccentrically inflates with respect to the axial center of the catheter tube.

However, in the prior art, it is necessary to attach a fixing tape as a member for causing the balloon to eccentrically inflate with respect to the axial center of the catheter tube from above the balloon, and the number of parts and the number of assembly steps at the time of assembly are required. There is a problem that there are many.

Japanese Unexamined Patent Publication No. 2008-194166

The present invention has been made in view of such an actual situation, and it is possible to reduce the number of parts and the assembly man-hours at the time of assembly, and the balloon can be eccentrically inflated with respect to the axial center of the catheter tube. It is an object of the present invention to provide a balloon catheter for removal.

In order to achieve the above object, the balloon catheter for removing calculus according to the present invention is used.
A catheter tube having a distal end and a proximal end,
A calculus-removing balloon catheter having a tubular balloon attached to the distal end of the catheter tube.
The balloon has a joint portion that is joined to the outer peripheral surface of the catheter tube, and an inflatable portion that can be expanded by introducing a fluid into the internal space.
An eccentric expansion means is provided in a part of the circumferential direction of the balloon so that the expansion portion eccentrically inflates with respect to the axial center of the catheter tube.
The eccentric expansion means is composed of an elongated member made of a material having a elastic modulus larger than that of the material constituting the balloon, and is integrally embedded in the membrane of the balloon along the longitudinal direction of the balloon. It is an expansion control member,
The balloon is restricted from expanding at the portion where the expansion regulating member is embedded, expands eccentrically with respect to the axial center of the catheter tube, and has a maximum bulging portion on the opposite side of the expansion regulating member. It is characterized by.

In the calculus removing balloon catheter according to the present invention, an expansion regulating member as a member for causing the balloon to eccentrically inflate with respect to the axial center of the catheter tube is integrally joined in the membrane of the balloon. It is buried. Therefore, since the balloon and the expansion control member are integrated into a single component, the number of components and the assembly man-hours at the time of assembly can be reduced. Further, since the expansion regulating member is embedded in the membrane of the balloon, the expansion regulating member does not come off from the balloon.

FIG. 1 is a schematic perspective view of a balloon catheter for removing stones according to an embodiment of the present invention. FIG. 2 is a schematic vertical sectional view of the balloon catheter for removing calculus shown in FIG. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is a schematic cross-sectional view of a balloon catheter for removing calculus according to another embodiment of the present invention.

As shown in FIGS. 1 and 2, the calculus removing balloon catheter 1 according to the embodiment of the present invention has a catheter tube 5 and a balloon 2. The catheter tube 5 is a tube made of a flexible material, and has a distal end 7 which is an end on the side to be inserted into the body and a proximal end located on the other end (not shown). And have. The outer diameter of the catheter tube 5 is usually 1.0 to 3.0 mm, and the total length is usually 500 to 2500 mm.

The material of the catheter tube 5 is not particularly limited as long as it is a flexible material, but a polymer material is preferable, and a polyamide resin or a polyamide-based elastomer is particularly preferable.

As shown in FIG. 2, a balloon lumen 8, a contrast medium lumen 9, and a guide wire lumen 10 are formed inside the catheter tube 5. The balloon lumen 8 is a lumen that serves as a flow path for sending a fluid such as air used for inflating the balloon 2 to the internal space 24 of the balloon 2. The balloon lumen 8 extends from the proximal end of the catheter tube 5 to the middle of the distal end 7 of the catheter tube 5, and has a fluid outlet 11 provided so as to open into the internal space 24 of the balloon 2. It is conducting.

The contrast medium lumen 9 is a lumen used as a flow path of the contrast medium when performing X-ray imaging in the body for the purpose of confirming the position of the stone 50 or the like. The contrast agent lumen 9 penetrates from the proximal end of the catheter tube 5 to the spout 12 of the distal end 7 of the catheter tube 5. The spout 12 is an opening provided so as to be located on the proximal end side of the balloon 2. The spout may be an opening provided so as to be located on the distal end side of the balloon 2.

The guide wire lumen 10 is a lumen through which the guide wire is inserted when the balloon catheter 1 for removing stones is inserted into the body along the guide wire, and the opening 10a from the proximal end to the distal end of the catheter tube 5 is inserted. It penetrates to. In the catheter tube 5, it is not always necessary to provide the contrast agent lumen 9 and the guide wire lumen 10, and it is also possible to form other lumens having a function other than the above-mentioned functions.

The cross-sectional shapes of the balloon lumen 8, the contrast agent lumen 9, and the guide wire lumen 10 are not limited, and each of them may be a shape that can be efficiently arranged in the catheter tube 5. However, the guide wire lumen 10 preferably has a circular cross-sectional shape. The cross-sectional area of the balloon lumen 8 is 0.03 to 0.3 mm ² , the cross-sectional area of the contrast agent rumen 9 is 0.08 to 0.8 mm ² , and the cross-sectional area of the guide wire lumen 10 is 0.5 to 0.5. It is preferably 1.0 mm ² .

The balloon 2 of the calculus removing balloon catheter 1 is attached to the distal end of the catheter tube 5 so as to cover the fluid outlet 11. The balloon 2 is made of an elastic material and is expanded by introducing a fluid into the balloon through the balloon lumen 8 of the catheter tube 5. The inflated balloon 2 can scrape or push out the calculus 50 to remove the calculus 50 in the body.

As the elastic material forming the balloon 2, the 100% modulus (value measured according to JIS K 6251) is preferably 0.1 to 10 Mpa, and particularly preferably 1 to 5 Mpa. If the 100% modulus is too small, the strength of the balloon 2 may be insufficient, and if it is too large, the balloon 2 may not be inflated to a sufficient size. Further, specific examples of the elastic material suitable for forming the balloon 2 include natural rubber, silicone rubber, polyurethane elastomer and the like.

As shown in FIGS. 1 to 3, the balloon 2 has a tubular shape as a whole, and joint portions 4a and 4b to be joined to the outer peripheral surface of the catheter tube 5 are formed at both ends thereof.

The shapes of the joints 4a and 4b located on both ends of the inflatable portion 3 of the balloon 2 are not particularly limited as long as they can be joined to the distal end 7 of the catheter tube 5, but are preferably cylindrical. .. When the joint portions 4a and 4b of the balloon 2 are cylindrical, the inner diameter thereof is preferably substantially equal to the outer diameter of the catheter tube 5, and the length thereof is preferably 0.5 to 5 mm. Further, the wall thickness of the joint portions 4a and 4b of the balloon 2 is not particularly limited, and may be substantially equal to, for example, the expansion portion 3. The method of joining the joining portions 4a and 4b of the balloon 2 and the distal end portion 7 of the catheter tube 5 is not particularly limited, and for example, bonding with an adhesive, heat fusion, welding with a solvent, and ultrasonic welding And so on.

In the balloon 2, an expansion portion 3 that expands when a fluid is introduced into the internal space 24 is formed between the joint portions 4a and 4b. 1 to 3 show an inflated balloon 2.

The maximum outer diameter of the inflated portion 3 of the balloon 2 in the inflated state is preferably 200 to 1500% of the outer diameter in the inflated state. If this ratio is too small, the balloon 2 may not expand to a sufficient size, and if it is too large, the balloon 2 may interfere with the insertion of the stone removing balloon catheter 1 into the body. The length of the inflatable portion 3 (the length along the axial direction of the catheter tube 5) in the balloon 2 is preferably 5 to 20 mm, and the wall thickness is preferably 0.10 to 0.50 mm. The wall thickness of the balloon 2 is preferably uniform along the circumferential direction.

In the present embodiment, the expansion regulating member 20 is provided as an eccentric expansion means provided in a part of the balloon 2 in the circumferential direction so that the expansion portion 3 expands eccentrically with respect to the axial center of the catheter tube 5. The expansion regulating member 20 is an elongated member made of a material having a higher elastic modulus (difficult to stretch) than the material constituting the balloon 2, and the entire side surface of the balloon 2 is formed in the membrane of the balloon 2 along the longitudinal direction of the balloon 2. Are buried in a state where they are integrally joined. When the fluid is introduced into the balloon 2 by the expansion regulating member 20, the balloon 2 is restricted from expanding in the portion where the expansion regulating member 20 is embedded, and expands eccentrically with respect to the axial center of the catheter tube 5. Then, it expands so as to have a maximum bulging portion on the opposite side of the expansion regulating member 20. The elastic modulus of the material constituting the balloon 2 is generally 3 to 20 MPa, and the elastic modulus of the material constituting the expansion regulating member 20 is 30% or more higher than the elastic modulus of the material constituting the balloon 2. Is preferable.

The material constituting the expansion control member 20 is not particularly limited as long as it has a higher elastic modulus than the material constituting the balloon 2. For example, a polymer material such as polyethylene, polypropylene, polyamide, polyacetal, or polyetheretherketone. Alternatively, metals such as iron, stainless steel, gold, platinum, tantalum, tungsten and nickel-titanium alloys can be mentioned. Further, the shape of the expansion regulating member 20 is not particularly limited, and examples thereof include a rod shape, a thread shape, a stranded wire shape, and a plate shape.

In the present embodiment, the expansion regulating member 20 extends in the axial direction of the balloon 2 and is integrally joined to the balloon 2 in a state where the entire side portion thereof is completely buried in the membrane of the balloon 2. .. It is most preferable that the entire side surface of the expansion regulating member 20 is completely embedded in the membrane of the balloon 2 from the viewpoint of preventing the balloon 2 from falling off, but there is a manufacturing convenience and the like. In this case, a part of the expansion regulating member 20 may be exposed to the outside of the balloon 2 on the condition that the expansion regulating member 20 does not easily fall off from the balloon 2 (the integrated state can be maintained). .. When a part of the expansion regulating member 20 is exposed to the outside of the balloon 2, it can be held inside the balloon 2 even if it comes off from the balloon 2, so that it is exposed to the inside of the balloon 2 instead of the outside. It is preferable to let it.

Further, in the present embodiment, the expansion regulating member 20 is embedded in the balloon 2 so as to be located substantially opposite to the position where the ejection port 12 is provided in the circumferential direction of the catheter tube 5. Therefore, when the fluid is introduced into the balloon 2, the balloon 2 expands so as to have a maximum bulging portion on the side substantially the same as the circumferential position of the ejection port 12. By substantially matching the circumferential position of the maximum bulging portion of the balloon 2 with the ejection port 12, when the balloon 2 is inflated, the ejection port 12 is easily separated from the body wall or the like, so that the ejection port 12 is ejected from the ejection port 12. The contrast medium is easily diffused, and X-ray contrast can be performed efficiently.

The method for producing the balloon 2 as described above is not particularly limited, and a known method may be used as a method for forming a film of an elastic material. However, in the present embodiment, the expansion regulating member 20 is integrated in the film of the balloon 2. A dipping molding method is used as a suitable manufacturing method for burying in a state of being joined together.

Hereinafter, a manufacturing method using the dipping molding method will be briefly described. First, the expansion control member 20 is provided along the longitudinal direction along the side portion of a mold having an outer shape substantially equal to the desired shape of the balloon 2 (here, a long, substantially columnar, straight-body mandrel is used). Temporarily hold. As the mandrel, a mandrel may be used instead of a straight body type having a bulging portion corresponding to a portion to be an swelling portion 3 of the balloon 2 after film formation.

The method of temporarily holding the expansion regulating member 20 with respect to the mandrel is not particularly limited, but it can be performed by using a holding member (clip or the like) that detachably holds both ends of the expansion regulating member 20 on the side portions of the mandrel. At this time, in order to completely bury the expansion regulating member 20 in the film of the balloon 2 after the film formation, the expansion regulating member 20 is slightly tensioned from the side of the mandrel while the expansion regulating member 20 is tensioned to some extent. It is preferable to hold it so that it floats, but it may be brought into contact with it.

Next, the elastic material and various additives as necessary are dissolved in a solvent to form a solution or suspension, and the mandrel in which the expansion control member 20 is temporarily held is immersed in this solution (suspension) to obtain the mandrel and the suspension. A solution (suspension) is applied to the surface of the expansion control member 20 to evaporate the solvent to form a film on the surface of the mandrel. By repeating this dipping and drying, a balloon having a desired wall thickness can be formed. Depending on the type of elastic material, if necessary, cross-linking is performed after film formation.

It should be noted that temporarily holding the expansion regulating member 20 so as to be slightly lifted from the mandrel requires a lot of labor in manufacturing, so the expansion regulating member 20 is simply brought into contact with the side portion of the mandrel. It may be held in a state. In this case, a part of the side portion of the expansion regulating member 20 (the portion that was in contact with the mandrel) may be exposed on the inner surface of the film of the balloon 2 on which the film is formed, but the expansion regulating member 20 is attached to the balloon 2. On the other hand, if the integrally joined state is maintained, there is no particular problem in the function of eccentricity, and even if the balloon is disengaged, the expansion regulating member 20 is held inside the balloon 2.

In this embodiment, the expansion regulating member 20 is embedded in the membrane of the balloon 2 in a state of being integrally joined. Therefore, as shown in FIG. 3, the expansion portion 3 of the balloon 2 is the shaft of the catheter tube 5. It eccentric to the heart and expands. The eccentricity h1 of the expansion center of the expansion portion 3 with respect to the axial center of the catheter tube 5 is preferably 50 to 100%, more preferably 75 to 100%, with respect to the expansion radius R of the expansion portion 3. The balloon 2 does not have to expand in a completely circular shape in its cross section, and may expand into an elliptical shape or other shape.

Next, as an example of using the balloon catheter 1 for removing stones of the present embodiment, an example of removing stones (gallstones) from the bile duct will be described.

First, with respect to the proximal end of the guide wire previously inserted into the bile duct via the channel of the endoscope, the guide wire is attached to the guide wire lumen 10 from the distal end side of the balloon catheter 1 for removing stones (not shown). From the distal end side of the catheter tube 5 through the channel of the endoscope and along the guide wire into the bile duct, the distal end side of the catheter tube 5 without inflating the balloon 2 To insert.

Next, the contrast medium is sent to the spout 12 via the contrast medium lumen 9 by a catheter or the like, the contrast medium is ejected, X-ray imaging in the bile duct is performed, and after confirming the state of the stone 50, the stone is formed. After pushing the balloon 2 of the catheter 1 to the back side of the 50, air is sent into the balloon 2 through the balloon lumen 8 by a syringe or the like to inflate the balloon 2. At this time, in the present embodiment, the inflated portion 3 of the balloon 2 is eccentrically inflated. If necessary, after inflating the balloon 2, X-ray imaging in the bile duct may be performed.

Subsequently, when the catheter 1 is pulled back with the balloon 2 inflated, the calculus 50 can be scraped out of the bile duct from the duodenal papilla by the balloon 2. At this time, in the catheter 1 of the present embodiment, as shown in FIG. 2, by pulling out the catheter tube 5 toward the proximal end side (in the direction of arrow X in FIG. 2), the inflated portion 3 of the balloon 2 inflated eccentrically. It is easy to scrape the stone 50 on the proximal end side of the maximum bulge.

In the portion where the expansion regulating member 20 is embedded, expansion is regulated, so that even if the stone 50 comes into contact with the proximal end side of the maximum bulging portion of the eccentrically inflated balloon 2 and a reaction force acts, the balloon swells. There is no escape for the fluid in the balloon 2 and it tries to maintain an eccentric inflated state. Therefore, the stone 50 does not escape from the inflated balloon 2, and the stone 50 has excellent removal characteristics.

Further, in the present embodiment, the inflated state of the eccentric balloon 2 can be created only by attaching the balloon 2 in which the expansion regulating member 20 is embedded to the catheter tube 5 according to a conventional method. That is, the number of parts and man-hours required for manufacturing the calculus removing balloon catheter 1 are small, and the manufacturing is extremely easy.

In the above-described embodiment, an example in which a wire rod is used as the expansion regulating member 20 has been described, but the shape of the expansion regulating member is not limited to this, and for example, as shown in FIG. 4, the expansion regulating member 20A is used. A strip-shaped thin plate may be used. The plate thickness t1 of the expansion regulating member 20A can be 1/10 to 9/10 of the film thickness t of the balloon 2. The width of the expansion regulating member 20A is a width of ½ or less, preferably 1/100 to 1/3 of the circumferential length of the outer circumference of the catheter tube 5. If this width is too large, it becomes difficult to eccentric and inflate the balloon 2.

The expansion regulating member 20A may have the same shape in the longitudinal direction thereof, but from the viewpoint of suppressing separation (disconnection) from the balloon 2 when the balloon 2 is inflated, a part thereof is included. A single or multiple protrusions or recesses may be provided.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

For example, in the above-described embodiment, the calculus removing balloon catheter 1 includes one balloon, but may include a plurality of balloons, and at least one of them may be a balloon having the above-mentioned shape.

Further, the balloon catheter 1 for removing calculus of the present invention may be used as long as it is used for removing calculus from the body, and is not limited to the use for removing gallstones.

1 ... Balloon catheter for removing stones 2 ... Balloon 3 ... Inflatable parts 4a, 4b ... Joint part 5 ... Catheter tube 8 ... Balloon lumen 9 ... Contrast agent lumen 10 ... Guide wire lumen 11 ... Fluid outlet 12 ... Ejection port 20, 20A ... Expansion control member 50 ... Stone

Claims (1)

A catheter tube having a distal end and a proximal end,
A calculus-removing balloon catheter having a tubular balloon attached to the distal end of the catheter tube.
The balloon has a joint portion that is joined to the outer peripheral surface of the catheter tube, and an inflatable portion that can be expanded by introducing a fluid into the internal space.
An eccentric expansion means is provided in a part of the circumferential direction of the balloon so that the expansion portion eccentrically inflates with respect to the axial center of the catheter tube.
The eccentric expansion means is composed of an elongated member made of a material having a elastic modulus larger than that of the material constituting the balloon, and is integrally embedded in the membrane of the balloon along the longitudinal direction of the balloon. It is an expansion control member,
The balloon is restricted from expanding at the portion where the expansion regulating member is embedded, expands eccentrically with respect to the axial center of the catheter tube, and has a maximum bulging portion on the opposite side of the expansion regulating member. A balloon catheter for removing stones.

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