JP7603466B2 - Balloon catheter and catheter system - Google Patents

Description

The present invention relates to a balloon catheter and a catheter system.

For example, Patent Document 1 discloses a catheter system that includes a balloon catheter for treating diseased parts (stenosis or obstruction) of the fallopian tubes, and an endoscope (fallopian tube scope). The balloon catheter includes a flexible outer tube, an inner tube disposed in the lumen of the outer tube so as to be movable in the axial direction relative to the outer tube, and a tubular balloon that connects the tip of the outer tube to the tip of the inner tube.

In fallopianoscopic salpingoplasty, the balloon is supported in an inflated state by the insertion part (linear part) of the fallopianoscope, which is inserted into the balloon's lumen, and a pushing force toward the tip is transmitted from the inner tube to the balloon, causing the tip of the balloon to turn over and protrude from the tip opening of the outer tube, and then inserted into the fallopian tube orifice.

Patent No. 3921108

In the above-mentioned fallopianoscopic salpingoplasty, in cases where the diseased part of the fallopian tube is completely blocked, a relatively large reaction force (force in the proximal direction) acts on the balloon when the diseased part is pushed open by the balloon. In this case, if the outer tube recedes relative to the balloon, there is a risk that the pushing force from the balloon cannot be efficiently applied to the diseased part.

The present invention was made in consideration of these problems, and aims to provide a balloon catheter and catheter system that can stably advance a balloon inside a biological tube and efficiently apply a pushing force from the balloon to the lesion.

One aspect of the present invention is a balloon catheter comprising: an outer tube having flexibility; an inner tube disposed in an inner cavity of the outer tube so as to be movable in an axial direction of the outer tube relative to the outer tube; and a tubular inner balloon portion disposed at a tip portion of the inner tube and inflated radially inwardly of the outer tube, wherein the tip portion of the inner balloon portion is turned back as a result of a pushing force being transmitted from the inner tube to the inner balloon portion while the inner balloon portion is inflated, and protrudes in a tip direction from a tip opening of the outer tube, wherein an outer lumen through which a balloon expansion fluid for expanding the inner balloon portion flows is provided between an outer peripheral surface of the inner tube and an inner peripheral surface of the outer tube, and an outer space into which the balloon expansion fluid flows is formed between the outer peripheral surface of the inner balloon portion and the inner peripheral surface of the outer tube, and the inner balloon portion is configured to have a diameter that is larger than that of the outer balloon portion. the balloon catheter inflates radially inwardly of the outer tube as the balloon expansion fluid flows into the outer space from the side lumen, and an annular outer balloon portion is provided on the outer peripheral surface of the outer tube which inflates radially outwardly of the outer tube, and when the inner balloon portion inflates and protrudes from the tip opening, a protruding portion is formed in which the inner balloon portion is folded over in the radial direction further distally than the tip opening, and the outer diameter of the outer balloon portion in the inflated state is larger than the outer diameter of the protruding portion, and the balloon catheter has a balloon connecting portion which connects one end of the inner balloon portion and one end of the outer balloon portion together in the distal direction further distally than the outer tube, the other end of the inner balloon portion is provided at the tip of the inner tube, and the other end of the outer balloon portion is provided on the outer peripheral surface of the outer tube .

Another aspect of the present invention is a catheter system comprising the above-mentioned balloon catheter and a linear balloon support portion that can be inserted into the inner cavity of the inner balloon portion through the inner cavity of the inner tube.

According to the present invention, since the outer diameter of the outer balloon portion in an inflated state is larger than the outer diameter of the protruding portion, the outer balloon portion can be pressed against the inner surface of the biological tube. This allows the inner balloon portion to advance stably within the biological tube. Furthermore, even if a relatively large reaction force acts on the inner balloon portion when the lesion is pushed open by the inner balloon portion (protruding portion), the reaction force can be received at the contact portion between the outer balloon portion and the inner surface of the biological tube. Therefore, the outer tube is prevented from being pushed back in the base end direction by the reaction force, and a pushing force can be efficiently applied from the inner balloon portion to the lesion portion.

1 is a schematic configuration diagram of a catheter system according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the catheter system of FIG. 1 with a portion thereof omitted. FIG. 3 is an enlarged cross-sectional view of the distal end side of the balloon catheter of FIG. 2. FIG. 3 is an enlarged cross-sectional explanatory view showing a state in which an inner balloon portion and an outer balloon portion are inflated in the catheter system of FIG. 2. FIG. 2 is a first explanatory diagram of salpingoscopic salpingoplasty using the catheter system of FIG. 1. FIG. 2 is a second explanatory diagram of the salpingoscopic salpingoplasty. FIG. 3 is a third explanatory diagram of the fallopianoscopic salpingoplasty. FIG. 4 is a fourth explanatory diagram of the fallopianoscopic salpingoplasty. FIG. 5 is a fifth explanatory diagram of the fallopianoscopic salpingoplasty. FIG. 6 is an explanatory diagram of the fallopianoscopic salpingoplasty. FIG. 11 is a cross-sectional view illustrating a balloon catheter according to a first modified example. FIG. 12 is an explanatory diagram of salpingoscopic salpingoplasty using a catheter system equipped with the balloon catheter of FIG. 11 . FIG. 13 is an explanatory diagram showing a state in which the inner balloon of the balloon catheter in FIG. 12 has been advanced.

Below, preferred embodiments of the balloon catheter and catheter system according to the present invention will be described with reference to the attached drawings.

As shown in FIG. 1, a catheter system 10 according to an embodiment of the present invention includes a balloon catheter 12 and an endoscope 14 (falling tube scope), which is a medical device. As shown in FIGS. 5 to 10, the catheter system 10 is used, for example, in fallopian tube endoscopic salpingoplasty for treating a lesion 204 (such as a stenosis or obstruction) in a fallopian tube 202. However, the catheter system 10 may also be used to treat lesions in biological tubes other than the fallopian tube 202, such as blood vessels, bile ducts, tracheas, esophagus, urethra, large intestine, and other organs.

In the following description of the catheter system 10, the left side in FIG. 1 (the direction of the arrow X1) is referred to as the "distal end," and the right side in FIG. 1 (the direction of the arrow X2) is referred to as the "base end."

As shown in Figures 1 and 2, the balloon catheter 12 includes an outer catheter 16, a slider 18 provided on the outer catheter 16, an inner catheter 20 inserted into the outer catheter 16, and a balloon 22.

The outer catheter 16 has a long, flexible outer tube 24, an outer tube hub 26 (outer tube operating section) provided at the base end of the outer tube 24, and a fixing screw 28 provided on the outer tube hub 26. The total length of the outer tube 24 is preferably set to 100 mm or more and 1500 mm or less, and more preferably set to 200 mm or more and 1000 mm or less.

Examples of materials that can be used to form the outer tube 24 include polyolefins (polyethylene, polypropylene, polybutene, etc.), polyesters (polyethylene terephthalate, etc.), elastomer resins (polyolefin elastomers, polyester elastomers, polyamide elastomers, polyurethane elastomers, etc.), flexible polymeric materials (polytetrafluoroethylene, polyimide, ethylene-vinyl acetate copolymers, silicone rubber, etc.), soft polyvinyl chloride, polyurethane, polyamide, and fluororesins.

In FIG. 3, the outer tube 24 is formed with a first lumen 30 that penetrates from the tip to the base end. An annular recess 32 is formed on the outer peripheral surface of the tip of the outer tube 24. The recess 32 extends to the tip surface of the outer tube 24. The tip side of the outer tube 24, the base end side of the recess 32, is shaped to be curved in an arc in the axial direction. The tip surface of the outer tube 24 is formed with a tapered surface 34 that is inclined from the outer peripheral surface toward the inner peripheral surface toward the tip.

As shown in Figures 1 and 2, the outer tube hub 26 is made of hard resin or metal (stainless steel, titanium, titanium alloy, etc.). Examples of hard resin include polycarbonate, acrylic resin, polyester, polyolefin, styrene-based resin, polyamide, polysulfone, polyarylate, polyetherimide, etc.

In FIG. 2, the outer tube hub 26 is hollow and sized to be easily operated by hand. The outer tube hub 26 is provided with a first space 36 communicating with the first lumen 30 of the outer tube 24, a first insertion hole 38 located on the base end side of the first space 36 and through which the inner catheter 20 is inserted, and a first introduction port portion 40 for introducing a balloon expansion fluid into the first space 36. The balloon expansion fluid is for inflating the balloon 22 shown in FIG. 2. The balloon expansion fluid is, for example, saline. The outer tube hub 26 is provided with a first seal member 42 for preventing the balloon expansion fluid in the first space 36 from leaking to the outside through the first insertion hole 38.

The fixing screw 28 is for fixing the inner catheter 20 to the outer tube hub 26. The fixing screw 28 may be made of the same material as the outer tube hub 26.

The slider 18 is provided in a state in which it can move (slide) in the axial direction of the outer tube 24 relative to the outer peripheral surface of the outer tube 24. The overall length of the slider 18 is shorter than the overall length of the outer tube 24. The slider 18 has a long tubular slider body 44 and a slider hub 46 (slider operation part) provided at the base end of the slider body 44. The slider body 44 and the slider hub 46 are each made of the same material as the outer tube hub 26 described above. The slider hub 46 is formed in an annular shape with a size that makes it easy to operate by hand.

When the slider 18 is moved to the most proximal side (arrow X2 direction) relative to the outer tube 24 (when the proximal end of the slider 18 is positioned at the tip of the outer tube hub 26), the tip side of the outer tube 24 is exposed further to the tip side than the slider 18 and is partially curved in an arc. When the slider 18 is moved to the most distal side (arrow X1 direction) relative to the outer tube 24, the tip side of the outer tube 24 extends in a straight line following the shape of the slider body 44.

As shown in Figures 1 and 2, the inner catheter 20 comprises a long inner tube 48 and an inner tube hub 50 (inner tube operating section) provided at the base end of the inner tube 48. The total length of the inner tube 48 is preferably set to 100 mm or more and 1500 mm or less, and more preferably set to 200 mm or more and 1000 mm or less.

In FIG. 2, the material of the inner tube 48 may be a relatively hard resin (e.g., fluororesin, polycarbonate, polyimide, PEEK resin, etc.) or a metal (e.g., stainless steel, titanium, titanium alloy, etc.). The inner tube 48 is formed with a second lumen 52 that runs through it from the tip to the base end.

The inner tube 48 is inserted through the outer tube hub 26 and disposed in the first lumen 30 of the outer tube 24. The tip of the inner tube 48 is located in the proximal direction (the direction of the arrow X2) from the tip of the outer tube 24. Between the outer peripheral surface of the inner tube 48 and the inner peripheral surface of the outer tube 24, an outer lumen Sa (expansion lumen) through which the balloon expansion fluid flows is provided.

The long insertion section 80 (linear section) of the endoscope 14, which also functions as a balloon support section, is inserted into the second lumen 52 of the inner tube 48. With the insertion section 80 inserted into the second lumen 52 of the inner tube 48, an inner lumen Sb (irrigation lumen) through which an irrigation fluid flows is formed between the inner tube 48 and the insertion section 80. The irrigation fluid is, for example, physiological saline.

The inner tube hub 50 is made of the same material as the outer tube hub 26. The inner tube hub 50 is formed to be hollow. The inner tube hub 50 is provided with a second space 54 that communicates with the second lumen 52 of the inner tube 48, a second insertion hole 56 located on the base end side of the second space 54 and through which the insertion part 80 is inserted, and a second introduction port part 58 for introducing irrigation fluid into the second space 54. The inner tube hub 50 is provided with a second seal member 60 that prevents the irrigation fluid in the second space 54 from leaking to the outside through the second insertion hole 56.

2 and 3, the balloon 22 includes a tubular inner balloon portion 62 provided at the tip of the inner tube 48, an annular outer balloon portion 64 provided on the outer peripheral surface of the outer tube 24, and a balloon connecting portion 66 that connects one end of the inner balloon portion 62 and one end of the outer balloon portion 64 to each other in the distal direction of the outer tube 24. The inner balloon portion 62, the outer balloon portion 64, and the balloon connecting portion 66 are provided on the balloon 22, which is an integrally molded product.

The balloon 22 (inner balloon portion 62, outer balloon portion 64, and balloon connecting portion 66) is preferably made of polyolefin (polyethylene, polypropylene, polybutene, etc.), polyester (polyethylene terephthalate, etc.), elastomer resin (polyolefin elastomer, polyester elastomer, polyamide elastomer, polyurethane elastomer, polystyrene elastomer, etc.), flexible polymeric material (natural rubber, ethylene-propylene copolymer, polytetrafluoroethylene, polyimide, ethylene-vinyl acetate copolymer, silicone rubber, etc.), soft polyvinyl chloride, polyurethane, polyamide, polyisoprene, polyester, fluororesin, etc.

Between the outer peripheral surface of the inner balloon portion 62 and the inner peripheral surface of the outer tube 24, an outer space Sc into which the balloon expansion fluid flows is formed. The inner balloon portion 62 expands radially inward of the outer tube 24 by the balloon expansion fluid that flows into the outer space Sc (see FIG. 4). In other words, the inner balloon portion 62 is formed to be elastically deformable in the radial direction.

The other end of the inner balloon portion 62 is fixed to the outer peripheral surface of the tip of the inner tube 48 by a balloon fixing member 68 (see FIG. 2). The balloon fixing member 68 is formed in a circular ring shape. The balloon fixing member 68 is disposed in the first lumen 30 of the outer tube 24. The other end of the inner balloon portion 62 may be fixed (glued or fused) to the tip of the inner peripheral surface of the inner tube 48. The inner balloon portion 62 has a lumen 70 into which the insertion portion 80 of the endoscope 14 can be inserted.

The outer balloon portion 64 is inflated radially outward of the outer tube 24 by the balloon expansion fluid (see FIG. 4). In other words, the outer balloon portion 64 is formed to be elastically deformable in the radial direction. The other end of the outer balloon portion 64 is fixed (glued or fused) to the bottom surface of the recess 32 formed on the outer peripheral surface of the outer tube 24. Specifically, only the other end of the outer balloon portion 64 is fixed (glued or fused) to the base end at the bottom surface of the recess 32. The portion of the outer balloon portion 64 other than the other end is not fixed to the outer tube 24. The portion of the inner peripheral surface of the outer balloon portion 64 other than the other end is in contact with or close to the bottom surface of the recess 32 when the outer balloon portion 64 is not inflated.

The outer balloon portion 64 is located radially outward of the inner balloon portion 62. The tip of the outer tube 24 is located between the outer balloon portion 64 and the inner balloon portion 62. In FIG. 3, the total length L1 (length along the direction of the arrow X) of the outer balloon portion 64 is preferably set to 5 mm or more and 30 mm or less. However, the total length L1 of the outer balloon portion 64 can be set as appropriate.

When the outer balloon portion 64 is not inflated, the outer diameter D1 of the outer balloon portion 64 is preferably set to 1 mm or more and 3 mm or less. In this case, the outer balloon portion 64 provided at the tip of the outer peripheral surface of the outer tube 24 can be inserted into the fallopian tube 202 (see FIG. 5). The thickness of the outer balloon portion 64 is preferably set to be approximately the same as the depth of the recess 32 of the outer tube 24. As a result, when the outer balloon portion 64 is not inflated, the portion of the outer peripheral surface of the outer tube 24 that is proximal to the recess 32 and the outer peripheral surface of the outer balloon portion 64 are flush with each other.

The balloon connector 66 extends in a circular ring shape. The cross section of the balloon connector 66 is formed so as to curve in an arc shape toward the tip in the initial state of the balloon catheter 12 (a state in which the inner balloon portion 62 does not protrude beyond the tip opening 72 of the outer tube 24). The balloon connector 66 expands toward the tip of the outer tube 24 by the balloon expansion fluid (see FIG. 4). The inner surface of the balloon connector 66 is in contact with or close to the tapered surface 34 of the outer tube 24 when the balloon connector 66 is not inflated.

In FIG. 4, when balloon expansion fluid is supplied to the outer space Sc, the inner balloon portion 62 expands radially inward of the outer tube 24, and the balloon connecting portion 66 expands toward the tip of the outer tube 24. When the balloon connecting portion 66 expands, the balloon expansion fluid in the outer space Sc is guided to the inner peripheral surface of the outer balloon portion 64 via the space Sd formed between the outer tube 24 and the balloon connecting portion 66. As a result, the outer balloon portion 64 expands radially outward, forming a space Se between the outer balloon portion 64 and the outer peripheral surface of the outer tube 24 (the bottom surface of the recess 32).

As shown in FIG. 7, when a pushing force (pushing force in the distal direction) is transmitted from the inner tube 48 to the inner balloon portion 62 while the balloon 22 (the inner balloon portion 62, the outer balloon portion 64, and the balloon connecting portion 66) is inflated in this manner, the tip of the balloon 22 (the tip of the inner balloon portion 62) is rolled back and protrudes distally from the tip opening 72 of the outer tube 24. At this time, a protruding portion 22b is formed in which the inner balloon portion 62 is folded twice in the radial direction distally beyond the tip opening 72. The outer diameter D2 of the outer balloon portion 64 in the inflated state is greater than the outer diameter D3 of the protruding portion 22b.

2 and 3, the endoscope 14 is a fallopian tube scope for observing the fallopian tube 202 (see FIG. 5). The endoscope 14 has a long, flexible insertion section 80 inserted into the second lumen 52 of the inner tube 48 of the balloon catheter 12 and the lumen 70 of the inner balloon section 62. Although not shown, the endoscope 14 also has a display section such as a display, and an imaging control device for displaying the captured image (endoscopic image) on the display section. An operation section (not shown) for operating the insertion section 80 is provided at the base end of the insertion section 80. The overall length of the insertion section 80 is set to, for example, about 2000 mm. However, the overall length of the insertion section 80 can be set as appropriate.

Next, we will explain how to perform salpingoscopic salpingoplasty using the catheter system 10 configured in this manner.

In fallopianoscopic tuboplasty, the above-mentioned catheter system 10 is prepared in a preparation process. In the preparation process, the user fixes the inner tube 48 by using the fixing screw 28 in a state where it is fully pulled toward the base end (in the direction of the arrow X2). Furthermore, the tip of the slider body 44 is positioned at the tip of the outer tube 24. This causes the tip side of the outer tube 24 to extend straight by the slider body 44.

Next, in the insertion step, the user inserts the balloon catheter 12 transcervically to the uterine fundus 200. Then, as shown in FIG. 5, in the sliding step, the slider 18 is pulled back in the proximal direction (arrow X2 direction) relative to the outer tube 24. As a result, the proximal side of the tip side of the outer tube 24 from the recess 32 is exposed from the slider 18 and becomes curved. At this time, the user positions the tip of the insertion section 80 of the endoscope 14 at the tip opening 72 of the outer tube 24 and inserts the tip of the outer tube 24 into the fallopian tube opening 202a while checking the fallopian tube opening 202a with the endoscopic image. At this time, the outer balloon section 64 is positioned inside the fallopian tube 202.

Then, the balloon extraction process is performed. Specifically, in the balloon extraction process, as shown in FIG. 6, a balloon expansion fluid is supplied to the first introduction port portion 40 (pressurization process). Then, the balloon expansion fluid is supplied from the first introduction port portion 40 through the outer lumen Sa to the outer space Sc of the inner balloon portion 62. Therefore, the inner balloon portion 62 is pressed radially inward by the balloon expansion fluid supplied to the outer space Sc and elastically deforms. In other words, the portion of the inner balloon portion 62 located on the outer periphery side of the insertion portion 80 is in close contact with the outer periphery of the insertion portion 80. The inner surfaces of the portions of the inner balloon portion 62 located further forward than the tip of the insertion portion 80 are in contact with each other.

The balloon connector 66 is elastically deformed by being pressed toward the tip by the balloon expansion fluid supplied to the outer space Sc. That is, the balloon connector 66 is inflated in an arc toward the tip by the balloon expansion fluid. As a result, the balloon expansion fluid in the outer space Sc is led to the space Sd formed between the balloon connector 66 and the tip of the outer tube 24. The outer balloon portion 64 is elastically deformed by being pressed radially outward of the outer tube 24 by the balloon expansion fluid led to the space Sd. In other words, the outer balloon portion 64 is inflated radially outward of the outer tube 24 by the balloon expansion fluid. As a result, the outer peripheral surface of the outer balloon portion 64 is pressed against the inner surface of the fallopian tube 202 near the fallopian tube orifice 202a. Therefore, the outer balloon portion 64 (the tip of the balloon catheter 12) is fixed to the fallopian tube 202.

Then, with the fixing screw 28 loosened, the user operates the inner tube hub 50 to advance the inner tube 48 relative to the outer tube 24 (advancement process). Then, as shown in FIG. 7, the inner balloon portion 62, which is pushed toward the distal end by the inner tube 48, advances together with the insertion portion 80 relative to the outer tube 24. In other words, the pushing force is transmitted from the inner tube 48 to the inner balloon portion 62, and the inner balloon portion 62 protrudes together with the insertion portion 80 from the distal end opening 72 of the outer tube 24 in the distal direction (the direction of arrow X1).

In the forward movement process, one end of the inner balloon portion 62 is fixed to the outer circumferential surface of the outer tube 24 via the balloon connector 66 and the outer balloon portion 64, so that the inner balloon portion 62 advances while its tip portion 22a is rolled up. That is, the inner balloon portion 62 is rolled up at its tip portion 22a so that its inner surface faces outward. Therefore, the inner balloon portion 62 advances a distance equivalent to half the advancement distance of the insertion portion 80. At this time, one end of the balloon connector 66 (the end on the inner balloon portion 62 side) moves further toward the tip than the other end of the balloon connector 66 (the end on the outer balloon portion 64 side). Therefore, the balloon connector 66 becomes inclined so that its diameter decreases toward the tip.

Furthermore, further distal than the distal opening 72 (distal to one end of the balloon connecting portion 66), the inner balloon portion 62 is folded twice in the radial direction to form a protruding portion 22b. The outer diameter D3 of the protruding portion 22b is smaller than the outer diameter D2 of the outer balloon portion 64. This prevents the protruding portion 22b from hitting the inner surface of the fallopian tube 202. In other words, the inner surface of the fallopian tube 202 is prevented from being excessively pressed by the protruding portion 22b.

In this forward movement process, the outer balloon portion 64 is fixed to the fallopian tube 202 by being pressed against the inner surface of the fallopian tube 202 near the fallopian tube opening 202a, so that the inner balloon portion 62 can be stably advanced within the fallopian tube 202.

Then, the user determines whether the balloon 22 has reached the lesion 204 based on the endoscopic image. If the balloon 22 is located in front of the lesion 204, the balloon expansion fluid is depressurized and perfusion fluid (perfusion fluid) is supplied to the second introduction port portion 58 (depressurization process). This allows perfusion fluid to flow between the balloon 22 and the insertion portion 80 of the endoscope 14 via the inner lumen Sb. Next, the user retracts the endoscope 14 a predetermined distance (retraction process) as shown in FIG. 8. Thereafter, the pressurization process and advancement process described above are performed again.

9, when the tip 22a of the inner balloon portion 62 comes into contact with the lesion 204, a reaction force acts on the tip 22a of the inner balloon portion 62 in the base end direction (arrow X2 direction) when the user pushes the inner tube 48 in the tip direction (arrow X1 direction). However, as described above, since the outer balloon portion 64 is fixed (pressed) against the inner surface of the fallopian tube 202, the reaction force in the base end direction acting on the tip 22a of the inner balloon portion 62 from the lesion 204 can be received at the contact portion between the outer balloon portion 64 and the inner surface of the fallopian tube 202. This prevents the outer tube 24 from moving in the base end direction relative to the balloon 22. In other words, since the tip opening 72 of the outer tube 24 is not pushed back to the outside of the fallopian tube 202, a pushing force can be efficiently applied from the balloon 22 (inner balloon portion 62) to the lesion 204.

After that, as shown in FIG. 10, when the balloon 22 completely passes through the lesion 204, the balloon 22 pushes open the lesion 204. In other words, the stenosis or blockage of the fallopian tube 202 is improved.

After expanding the lesion 204, the user reduces the pressure of the balloon expansion fluid and then removes the balloon catheter 12 and the endoscope 14 (removal process). Note that before removing the balloon catheter 12, the user may inject irrigation fluid through the second introduction port 58 while pulling the inner tube 48 to retract the balloon 22, and at the same time, operate the endoscope 14 to position it at the tip 22a of the balloon 22, thereby removing the balloon catheter 12 while observing the inside of the fallopian tube 202 during the removal process. This completes the fallopianoscopic salpingoplasty.

This embodiment provides the following advantages:

According to this embodiment, since the outer diameter D2 of the outer balloon portion 64 in the inflated state is larger than the outer diameter D3 of the protruding portion 22b, the outer balloon portion 64 can be pressed against the inner surface of the fallopian tube 202 and fixed. This allows the inner balloon portion 62 to advance stably within the fallopian tube 202. Even if a relatively large reaction force acts on the inner balloon portion 62 when the lesion portion 204 is pushed open by the inner balloon portion 62 (protruding portion 22b), the reaction force can be received at the contact portion between the outer balloon portion 64 and the inner surface of the fallopian tube 202. Therefore, the outer tube 24 is prevented from being pushed back in the base end direction by the reaction force, and a pushing force can be efficiently applied from the inner balloon portion 62 to the lesion portion 204.

The outer balloon portion 64 is provided at the tip of the outer tube 24.

With this configuration, by inserting the tip of the outer tube 24 into the fallopian tube 202, the outer balloon portion 64 can be positioned on the inner surface of the fallopian tube 202 near the fallopian tube orifice 202a (balloon insertion port). This allows the pushing force from the inner balloon portion 62 to be applied to the diseased area 204 more efficiently.

The balloon catheter 12 has a balloon connecting portion 66 that connects one end of the inner balloon portion 62 and one end of the outer balloon portion 64 to each other in the distal direction of the outer tube 24. The other end of the inner balloon portion 62 is provided at the distal end of the inner tube 48, and the other end of the outer balloon portion 64 is provided on the outer peripheral surface of the outer tube 24.

With this configuration, the inner balloon portion 62, the outer balloon portion 64, and the balloon connecting portion 66 can be configured as a single member.

The inner balloon portion 62, the outer balloon portion 64, and the balloon connecting portion 66 are provided on the balloon 22, which is an integrally molded product.

This configuration allows the configuration of the balloon 22 to be simplified.

The catheter system 10 includes a balloon catheter 12 and an insertion portion 80 (balloon support portion) of an endoscope 14 that can be inserted into the inner cavity 70 of the balloon 22 via the second inner cavity 52 of the inner tube 48.

With this configuration, the balloon 22 can be supported by the insertion section 80 of the endoscope 14, allowing the pushing force from the balloon 22 to be applied to the lesion 204 more efficiently.

In the above-described balloon catheter 12, at least one of the outer tube 24 and the slider 18 may be provided with a movement limiting portion (e.g., a convex portion, etc.) that limits the movement of the slider 18 toward the tip relative to the outer tube 24. In this case, the movement limiting portion is provided so that the tip of the slider 18 stops at a position just before the base end of the outer balloon portion 64. The movement limiting portion may also be provided so that the tip of the slider 18 stops at a position just before the balloon connecting portion 66.

(First Modification)
Next, a balloon catheter 12A according to a first modified example will be described with reference to Figures 11 to 13. In the balloon catheter 12A according to this modified example, the same components as those in the balloon catheter 12 described above are given the same reference numerals, and descriptions thereof will be omitted.

As shown in FIG. 11, the balloon catheter 12A includes an outer catheter 16a, a slider 18, an inner catheter 20 (see FIG. 1 and FIG. 2), and a balloon 23. The outer catheter 16a includes an outer tube 24a, the outer tube hub 26, and a fixing screw 28 (see FIG. 1 and FIG. 2). An annular recess 32a is formed on the outer peripheral surface of the tip of the outer tube 24a. The tip of the recess 32a is located on the base end side of the tip of the outer tube 24a. A through hole 90 is formed on the bottom surface of the recess 32a, opening into the inner peripheral surface of the outer tube 24a. The through hole 90 is located at the center of the axial direction (arrow X direction) of the outer tube 24a on the bottom surface of the recess 32a. In this embodiment, there is one through hole 90. However, the number, position, and size of the through holes 90 can be changed as appropriate.

A tapered surface 92 is formed on the outer peripheral surface of the outer tube 24a, on the distal side of the recess 32a, which slopes radially inward toward the very tip of the outer tube 24a. A balloon outlet hole 94 having a smaller diameter than the first lumen 30 is formed at the very tip of the outer tube 24a. A step 96 is formed on the inner peripheral surface of the outer tube 24a at the boundary between the balloon outlet hole 94 and the first lumen 30.

The balloon 23 has an inner balloon portion 62a and an outer balloon portion 64a. The inner balloon portion 62a and the outer balloon portion 64a are formed as separate members. The materials constituting the inner balloon portion 62a and the outer balloon portion 64a may be the same as those constituting the balloon 22 described above.

The inner balloon portion 62a connects the tip of the inner tube 48 (see FIG. 2) and the tip of the outer tube 24a. Specifically, one end of the inner balloon portion 62a is fixed (glued or fused) to the step portion 96. One end of the inner balloon portion 62a is located in the tip direction (arrow X1 direction) from the tip of the recess 32a of the outer tube 24a. The other end of the inner balloon portion 62a is fixed to the inner tube 48 in the same manner as the other end of the inner balloon portion 62 described above (see FIG. 2).

Between the outer peripheral surface of the inner balloon portion 62a and the inner peripheral surface of the outer tube 24a, a bag-shaped outer space Sc with a closed tip is formed. A through hole 90 is connected to the outer space Sc. The inner balloon portion 62a is inflated radially inward of the outer tube 24a by the balloon expansion fluid supplied to the outer space Sc (see FIG. 12). In other words, the inner balloon portion 62a is formed to be elastically deformable in the radial direction.

The outer balloon portion 64a is provided in the recess 32a. The outer balloon portion 64a is inflated radially outward of the outer tube 24a by the balloon expansion fluid guided from the outer space Sc to the inner peripheral surface of the outer balloon portion 64a through the through hole 90 (see FIG. 12). In other words, the outer balloon portion 64a is formed to be elastically deformable in the radial direction. The outer balloon portion 64a has both axial ends fixed (adhered or fused) to the bottom surface of the recess 32a so that the axial middle portion of the outer balloon portion 64a is inflated. The middle portion of the outer balloon portion 64a is in contact with or close to the bottom surface of the recess 32a when the outer balloon portion 64a is not inflated.

The outer balloon portion 64a is located radially outward of the inner balloon portion 62a. The tip of the outer tube 24a is located between the outer balloon portion 64a and the inner balloon portion 62a. The total length L2 (length along the direction of the arrow X) of the outer balloon portion 64a is set to the same length L1 of the outer balloon portion 64 described above.

When the outer balloon portion 64a is not inflated, the outer diameter D4 of the outer balloon portion 64a is set to be the same as the outer diameter D1 of the outer balloon portion 64 described above. The thickness of the outer balloon portion 64a is preferably set to be approximately the same as the depth of the recess 32a of the outer tube 24a. As a result, when the outer balloon portion 64a is not inflated, the portion of the outer surface of the outer tube 24a that is closer to the base end than the recess 32a and the outer surface of the outer balloon portion 64a are flush with each other.

As shown in FIG. 13, when a pushing force (pushing force in the tip direction) is transmitted from the inner tube 48 to the inner balloon portion 62a while the balloon 23 (the inner balloon portion 62a and the outer balloon portion 64a) is inflated, the tip portion of the balloon 23 (the tip portion of the inner balloon portion 62) is rolled back and protrudes in the tip direction from the tip opening 72 of the outer tube 24a. At this time, a protruding portion 22b is formed in which the inner balloon portion 62a is folded twice in the radial direction in the tip direction from the tip opening 72. The outer diameter D5 of the outer balloon portion 64a in the inflated state is larger than the outer diameter D6 of the protruding portion 22b.

As shown in FIG. 12, in the balloon catheter 12A according to this modification, when balloon expansion fluid is supplied to the outer space Sc during the pressurization step, the inner balloon portion 62a expands radially inwardly of the outer tube 24a. The balloon expansion fluid in the outer space Sc is also guided to the inner peripheral surface of the outer balloon portion 64a through the through hole 90. Therefore, the outer balloon portion 64a expands radially outwardly of the outer tube 24a. This causes the outer balloon portion 64a to be pressed against the inner surface of the fallopian tube 202 near the fallopian tube orifice 202a. In other words, the outer balloon portion 64a is fixed to the fallopian tube 202.

Also, as shown in FIG. 13, when the inner tube 48 is advanced relative to the outer tube 24 in the forward advancement step, the inner balloon portion 62a, which is pressed toward the tip by the inner tube 48, advances relative to the outer tube 24 together with the insertion portion 80. At this time, since one end of the inner balloon portion 62a is fixed to the tip of the outer tube 24a in the forward advancement step, the inner balloon portion 62a advances while its tip portion 22a (protruding end portion) is rolled up. That is, the inner balloon portion 62a is rolled up at its tip portion 22a (protruding end portion) so that the inner surface faces outward. Therefore, the inner balloon portion 62a advances a distance equivalent to half the advancement distance of the insertion portion 80. Also, since the outer balloon portion 64a is fixed relative to the fallopian tube 202, the inner balloon portion 62a can be stably advanced within the fallopian tube 202.

In this type of balloon catheter 12A, the same configuration as the balloon catheter 12 described above provides the same effects. In addition, this modified example provides the following effects.

The inner balloon portion 62a and the outer balloon portion 64a are formed as separate members.

This configuration allows the position of the outer balloon portion 64a relative to the outer tube 24a to be set relatively freely without relying on the inner balloon portion 62a. Also, as shown in FIG. 12, when the balloon 23 (the inner balloon portion 62a and the outer balloon portion 64a) is inflated in the pressurizing step, the inner balloon portion 62a can be prevented from bulging (protruding) in the distal direction beyond the distal end of the outer tube 24a.

One end of the inner balloon portion 62a is fixed to the tip of the outer tube 24a, and the other end of the inner balloon portion 62a is fixed to the tip of the inner tube 48.

This configuration allows the inner balloon portion 62a to protrude in the distal direction from the distal opening 72 of the outer tube 24a so that the distal end of the inner balloon portion 62a is turned back.

The outer balloon portion 64a has both axial ends fixed to the outer tube 24a so that the axial middle portion of the outer balloon portion 64a is inflated.

This configuration allows the axial middle portion of the outer balloon portion 64a to be effectively inflated.

The outer tube 24a has a through hole 90 that guides the balloon expansion fluid in the outer space Sc formed between the outer peripheral surface of the inner balloon portion 62a and the inner peripheral surface of the outer tube 24a to the inner peripheral surface of the outer balloon portion 64a.

With this configuration, the balloon expansion fluid can be guided from the outer space Sc to the inner surface of the outer balloon portion 64a through the through hole 90, causing the outer balloon portion 64a to expand radially outward from the outer tube 24a.

This modified example is not limited to the above-mentioned configuration. In the balloon catheter 12A, the outer balloon portion 64a may be disposed at the base end of the outer tube 24a. In this case, for example, the outer balloon portion 64a can be inflated radially outward of the outer tube 24a to be fixed near the cervix. In the balloon catheter 12A, the outer balloon portion 64a may be disposed at or near the central portion in the axial direction of the outer tube 24a. This allows the outer balloon portion 64a to be fixed, for example, at the intermediate portion between the uterine fundus 200 and the cervix. In this case, the balloon catheter 12A is designed so that the outer balloon portion 64a is exposed from the slider 18 by pulling the slider 18 in the base end direction relative to the outer tube 24a. In addition, the slider 18 may function as a trigger for expanding the outer balloon portion 64a in addition to the function of maintaining the shape of the tip portion of the outer tube 24a in a straight line.

In the above-described balloon catheter 12A, at least one of the outer tube 24a and the slider 18 may be provided with a movement limiting portion (e.g., a convex portion, etc.) that limits the movement of the slider 18 toward the tip relative to the outer tube 24a. In this case, the movement limiting portion is provided so that the tip of the slider 18 stops at a position just before the base end of the outer balloon portion 64a. The movement limiting portion may also be provided so that the tip of the slider 18 stops at a position just before the tapered surface 92.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. The balloon support part is not limited to the insertion part 80 of the endoscope 14, and may be a linear member such as a guide wire or a catheter. Furthermore, when the catheter system according to the present invention is used to treat the large intestine, the outer balloon part is fixed to the inner surface of the large intestine near the anus. Furthermore, when the catheter system according to the present invention is used to treat a blood vessel, the outer balloon part is fixed to the inner surface of the blood vessel.

The above embodiments can be summarized as follows:

The above embodiment has a flexible outer tube (24, 24a), an inner tube (48) disposed in the inner cavity (30) of the outer tube so as to be movable in the axial direction of the outer tube relative to the outer tube, and a tubular inner balloon portion (62, 62a) provided at the tip of the inner tube and inflated radially inwardly of the outer tube, and the inner balloon portion is inflated in such a manner that a pushing force is transmitted from the inner tube to the inner balloon portion while the tip of the inner balloon portion is turned over and moves in the distal direction from the tip opening (72) of the outer tube. The balloon catheter (12, 12A) is a balloon catheter that protrudes from the distal end of the outer tube, and the outer peripheral surface of the outer tube is provided with an annular outer balloon portion (64, 64a) that protrudes radially outward from the distal end opening. When the inner balloon portion is in an inflated state and protrudes from the distal end opening, a protruding portion (22b) is formed in which the inner balloon portion is folded over in the radial direction, and the outer diameter (D2, D5) of the outer balloon portion in an inflated state is larger than the outer diameter (D3, D6) of the protruding portion.

In the above balloon catheter, the outer balloon portion may be provided at the tip of the outer tube.

In the above balloon catheter, the balloon catheter may have a balloon connecting portion (66) that connects one end of the inner balloon portion and one end of the outer balloon portion to each other in the distal direction of the outer tube, the other end of the inner balloon portion may be provided at the distal end of the inner tube, and the other end of the outer balloon portion may be provided on the outer peripheral surface of the outer tube.

In the above balloon catheter, the inner balloon portion, the outer balloon portion, and the balloon connecting portion may be provided on a balloon (22) that is an integrally molded product.

In the above balloon catheter, the inner balloon portion and the outer balloon portion may be formed as separate members.

In the above balloon catheter, one end of the inner balloon portion may be fixed to the tip of the outer tube, and the other end of the inner balloon portion may be fixed to the tip of the inner tube.

In the above-mentioned balloon catheter, both axial ends of the outer balloon portion may be fixed to the outer tube so that the axial middle portion of the outer balloon portion is inflated.

In the above balloon catheter, the outer tube may have a through hole (90) formed therein to guide the balloon expansion fluid in the outer space (Sc) formed between the outer peripheral surface of the inner balloon portion and the inner peripheral surface of the outer tube to the inner peripheral surface of the outer balloon portion.

The above embodiment discloses a catheter system (10) including the above-mentioned balloon catheter and a linear balloon support portion (80) that can be inserted into the inner cavity (70) of the inner balloon portion via the inner cavity (52) of the inner tube.

In the above catheter system, the balloon support portion may be the insertion portion (80) of the endoscope (14).

10... Catheter system 12, 12A... Balloon catheter 14... Endoscope 22, 23... Balloon 22a... Tip portion 22b... Projection portion 24, 24a... Outer tube 30... First lumen 48... Inner tube 52... Second lumen 62, 62a... Inner balloon portion 64, 64a... Outer balloon portion 66... Balloon connecting portion 72... Tip opening 80... Insertion portion (balloon support portion) 90... Through hole

Claims (5)

the balloon includes an outer tube having flexibility, an inner tube disposed in the inner cavity of the outer tube so as to be movable in the axial direction of the outer tube relative to the outer tube, and a tubular inner balloon portion provided at a tip end of the inner tube and inflated radially inwardly of the outer tube,
a balloon catheter in which a pushing force is transmitted from the inner tube to the inner balloon portion while the inner balloon portion is inflated, so that a tip portion of the inner balloon portion is turned back and protrudes in a tip direction from a tip opening of the outer tube,
an outer lumen through which a balloon inflation fluid for inflating the inner balloon portion flows is provided between an outer peripheral surface of the inner tube and an inner peripheral surface of the outer tube;
an outer space into which the balloon inflation fluid flows is formed between an outer peripheral surface of the inner balloon portion and an inner peripheral surface of the outer tube;
The inner balloon portion is inflated radially inwardly of the outer tube by the balloon inflation fluid flowing from the outer lumen into the outer space,
An outer circumferential surface of the outer tube is provided with an annular outer balloon portion that bulges outward in a radial direction of the outer tube,
With the inner balloon portion in an inflated state protruding from the distal end opening, a protruding portion is formed in which the inner balloon portion is folded in a radial direction in the distal direction from the distal end opening,
an outer diameter of the outer balloon portion in an inflated state is greater than an outer diameter of the protrusion;
the balloon catheter has a balloon connecting portion that connects one end of the inner balloon portion and one end of the outer balloon portion to each other in the distal direction relative to the outer tube,
The other end of the inner balloon portion is provided at a tip portion of the inner tube,
A balloon catheter , wherein the other end of the outer balloon portion is provided on the outer peripheral surface of the outer tube . 2. The balloon catheter according to claim 1,
A balloon catheter, wherein the outer balloon portion is provided at the tip portion of the outer tube. 3. The balloon catheter according to claim 1 ,
A balloon catheter, wherein the inner balloon portion, the outer balloon portion and the balloon connecting portion are provided on a balloon that is an integrally molded product. A balloon catheter according to any one of claims 1 to 3 ,
a linear balloon support portion insertable into the lumen of the inner balloon portion through the lumen of the inner tube. 5. The catheter system of claim 4 ,
A catheter system, wherein the balloon support portion is an insertion portion of an endoscope.

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