JP7532277B2 - 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 a fallopian tube scope (endoscope). 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 with the tip of the inner tube and expands radially inward of the outer tube.

Between the outer circumferential surface of the balloon and the inner circumferential surface of the outer tube, an outer space is formed through which a balloon expansion fluid flows to inflate the balloon radially inward. In fallopianoscopic salpingoplasty, the balloon is supported in an inflated state by the linear insertion part of the fallopianoscope, and a pushing force toward the tip is transmitted from the inner tube to the balloon, causing the tip of the balloon to turn back and protrude from the tip opening of the outer tube and be 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 pushing force may be required to push open the diseased part with the balloon. If the pushing force is excessive, a large axial compressive force acts on the balloon, which may cause the balloon and the insertion part to buckle and deform inside the outer tube (in the outer space).

The present invention was made in consideration of these problems, and aims to provide a balloon catheter and catheter system that can suppress buckling deformation of the insertion portion inside the outer tube.

One aspect of the present invention is a balloon catheter having a flexible outer tube, an inner tube disposed in the inner cavity 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 with the tip of the inner tube and expands radially inward of the outer tube, in which an outer space through which a balloon expansion fluid for expanding the balloon flows is formed between the outer peripheral surface of the balloon and the inner peripheral surface of the outer tube, and in a state in which the balloon inflated by the balloon expansion fluid is supported by a linear insertion part of a medical device, a pushing force in the distal direction is transmitted from the inner tube to the balloon, causing the tip of the balloon to roll back and protrude in the distal direction from the distal opening of the outer tube, and a bending suppression member extending in the circumferential direction of the balloon so as to go around the balloon is provided in the outer space.

Another aspect of the present invention is a catheter system comprising the above-mentioned balloon catheter and the medical device.

According to the present invention, a bending suppression member that extends around the balloon in the circumferential direction is provided in the outer space, so that when a relatively large axial compressive force acts on the balloon, the outer circumferential surface of the balloon can be brought into contact with the bending suppression member before the balloon and the insertion section are significantly deformed in a direction intersecting the axial direction. This makes it possible to suppress buckling deformation of the insertion section.

1 is a schematic configuration diagram of a catheter system including a balloon catheter according to an embodiment of the present invention. FIG. FIG. 2 is a longitudinal sectional view of the catheter system of FIG. 1 with a portion thereof omitted. 3A is a cross-sectional view taken along line IIIA-IIIA in FIG. 2, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 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 modified example. 11 is a cross-sectional view taken along line XI-XI of FIG. 10.

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. 4 to 9, 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, a balloon 22, a rotation restriction portion 23, and a deflection suppression member 25.

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.

2, the outer tube 24 includes an outer tube body 30 and a tip member 32 (tip) provided at the tip of the outer tube body 30. Examples of materials constituting the outer tube body 30 and the tip member 32 include polyolefins (e.g., polyethylene, polypropylene, polybutene, etc.), polyesters (e.g., polyethylene terephthalate, etc.), elastomer resins (e.g., polyolefin elastomers, polyester elastomers, polyamide elastomers, fluororesin elastomers, polyurethane elastomers, etc.), flexible polymeric materials (polytetrafluoroethylene, polyimide, ethylene-vinyl acetate copolymers, silicone rubber, etc.), soft polyvinyl chloride, polyurethane, polyamide, etc.

The outer tube body 30 has a first lumen 34 that penetrates from the tip to the base end. The tip of the outer tube body 30 is shaped so as to be curved in an arc in the axial direction. The outer tube body 30 has a generally constant outer diameter over its entire length.

3A and 3B, the inner peripheral surface 36 of the outer pipe body 30 has a curved surface 46 whose cross section is an arc, and a flat surface 48 that is continuous with the curved surface 46. The curved surface 46 extends 180° or more in the circumferential direction of the outer pipe body 30.

In FIG. 2, the outer surface of the tip member 32 is curved to prevent damage to the balloon catheter 12 or biological tissue. The tip member 32 is formed with a balloon outlet hole 52 for leading the balloon 22 in the distal direction (arrow X1 direction) from the tip member 32. The balloon outlet hole 52 is connected to the tip opening 54 of the outer tube 24.

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 formed hollow and has a size that makes it easy to operate by hand. The outer tube hub 26 is provided with a first space 53 that communicates with the first lumen 34 of the outer tube 24, a first insertion hole 55 located on the base end side of the first space 53 and through which the inner catheter 20 is inserted, and a first introduction port portion 56 for introducing a balloon expansion fluid into the first space 53. The balloon expansion fluid is for inflating the balloon 22 shown in FIG. 2 radially inward of the outer tube 24. The balloon expansion fluid is, for example, physiological saline. The outer tube hub 26 is provided with a first seal member 57 that prevents the balloon expansion fluid in the first space 53 from leaking to the outside through the first insertion hole 55.

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 body 30. 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 58 and a slider hub 60 (slider operation part) provided at the base end of the slider body 58. The slider body 58 and the slider hub 60 are each made of the same material as the outer tube hub 26 described above. The slider hub 60 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 body 30 (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 body 30 is exposed further to the tip side than the slider 18 and curves in an arc. When the slider 18 is moved to the most distal side (arrow X1 direction) relative to the outer tube body 30, the tip side of the outer tube body 30 extends in a straight line along the shape of the slider body 58.

As shown in Figures 1 and 2, the inner catheter 20 comprises a long inner tube 62 and an inner tube hub 64 (inner tube operating section) provided at the base end of the inner tube 62. The total length of the inner tube 62 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 62 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 62 has a second lumen 66 that runs through it from the tip to the base end.

The inner tube 62 is inserted through the outer tube hub 26 and disposed in the first lumen 34 of the outer tube body 30. The tip of the inner tube 62 is located in the proximal direction (arrow X2 direction) from the tip of the outer tube body 30. Between the outer peripheral surface of the inner tube 62 and the inner peripheral surface 36 of the outer tube body 30, an outer lumen Sa (expansion lumen) through which balloon expansion fluid flows is provided.

A long, linear insertion section 90 of the endoscope 14, which also functions as a balloon support device, is inserted into the second lumen 66 of the inner tube 62. With the insertion section 90 inserted into the second lumen 66 of the inner tube 62, an inner lumen Sb (irrigation lumen) through which an irrigation fluid flows is formed between the inner tube 62 and the insertion section 90. The irrigation fluid is, for example, physiological saline.

The inner tube hub 64 is made of the same material as the outer tube hub 26. The inner tube hub 64 is formed to be hollow. The inner tube hub 64 is provided with a second space 68 that communicates with the second lumen 66 of the inner tube 62, a second insertion hole 70 located on the base end side of the second space 68 and through which the insertion part 90 is inserted, and a second introduction port part 72 for introducing irrigation fluid into the second space 68. The inner tube hub 64 is provided with a second seal member 73 that prevents the irrigation fluid in the second space 68 from leaking to the outside through the second insertion hole 70.

The balloon 22 is a tubular member that connects the tip of the outer tube 24 and the tip of the inner tube 62. The balloon 22 is inflated radially inward of the outer tube 24 by the balloon expansion fluid. In other words, the balloon 22 is formed to be elastically deformable in the radial direction.

The balloon 22 is preferably made of polyolefin (e.g., polyethylene, polypropylene, polybutene, etc.), polyester (polyethylene terephthalate, etc.), elastomer resin (polyolefin elastomer, polyester elastomer, polyamide elastomer, fluororesin elastomer, polyurethane 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, etc.

One end of the balloon 22 is adhered or fused to the tip of the outer tube 24 (the base end of the tip member 32). In other words, one end of the balloon 22 is adhered or fused to the outer tube 24 near the base end side of the balloon outlet hole 52. Specifically, one end of the balloon 22 is sandwiched between the tip of the outer tube main body 30 and the tip member 32. The other end of the balloon 22 is adhered or fused to the tip of the outer peripheral surface of the inner tube 62.

The other end of the balloon 22 is fixed to the tip of the inner tube 62 by a balloon fixing member 74 (pressing portion). The other end of the balloon 22 may be glued or fused to the tip of the inner surface of the inner tube 62. The balloon 22 has an inner cavity 76 into which the insertion portion 90 of the endoscope 14 can be inserted. A bag-shaped outer space Sc with a closed tip is formed between the outer surface of the balloon 22 and the inner surface 36 of the outer tube main body 30. The balloon fixing member 74 is formed in an annular shape. The outer diameter of the balloon fixing member 74 is larger than the outer diameter of the uninflated balloon 22. The balloon fixing member 74 functions as a pressing portion for pressing the deflection suppression member 25 toward the tip.

5 and 6, when a pushing force (pushing force in the tip direction) is transmitted from the inner tube 62 to the balloon 22, the tip 22a of the balloon 22 is rolled back and protrudes in the tip direction from the tip opening 54 of the outer tube 24. At this time, a radially double-folded portion is formed in the protruding portion 22b of the balloon 22 that protrudes in the direction of the arrow X1 beyond the tip opening 54 of the outer tube 24.

As shown in FIG. 3B, the rotation restricting portion 23 is provided at the tip of the inner tube 62 and restricts the circumferential rotation of the inner tube 62 relative to the outer tube 24. The rotation restricting portion 23 is fixed to the outer peripheral surface of the inner tube 62 at the base end side of the balloon fixing member 74 (see FIG. 2). The rotation restricting portion 23 has a ring portion 80 and two protrusions 82a, 82b that protrude radially outward from the outer peripheral surface of the ring portion 80.

The inner peripheral surface of the annular portion 80 is fixed (glued or fused) to the outer peripheral surface of the inner tube 62. That is, the inner tube 62 is inserted through the inner cavity of the annular portion 80. The outer peripheral surface of the annular portion 80 is in contact with the curved surface 46 and the flat surface 48. The two convex portions 82a, 82b are offset toward the flat surface 48 from the center of the annular portion 80. The convex portion 82a is located on one side of a line segment La that is perpendicular to the flat surface 48 and passes through the center of the annular portion 80 (to the right of the line segment La in FIG. 3B). The convex portion 82b is located on the other side of the line segment La (to the left of the line segment La in FIG. 3B). The two convex portions 82a, 82b are close to the flat surface 48. Each of the convex portions 82a, 82b extends over the entire length of the annular portion 80 along the direction of the arrow X. Each of the protrusions 82a and 82b has an outer periphery with an arc-shaped cross section.

When the inner tube 62 rotates in the direction of arrow R1 in FIG. 3B relative to the outer tube 24, the convex portion 82a comes into contact with the flat surface 48, thereby suppressing twisting of the balloon 22 in the direction of arrow R1. When the inner tube 62 rotates in the direction of arrow R2 in FIG. 3B relative to the outer tube 24, the convex portion 82b comes into contact with the flat surface 48, thereby suppressing twisting of the balloon 22 in the direction of arrow R2.

As shown in FIG. 2, the flexure suppression member 25 is provided in the outer space Sc. The flexure suppression member 25 extends in the circumferential direction of the balloon 22 so as to go around the balloon 22. The flexure suppression member 25 is a coil member 88 having a plurality of winding portions 86 formed by spirally winding a wire 84 on the outer periphery side of the balloon 22. The balloon 22 is inserted into the inner cavity of the coil member 88.

The tip of the coil member 88 is fixed to the tip of the outer tube 24 (the tip of the inner circumferential surface 36 of the outer tube body 30). The base end of the coil member 88 is in contact with the balloon fixing member 74. The base end of the coil member 88 may or may not be fixed to the balloon fixing member 74. When a pushing force is transmitted from the inner tube 62 to the balloon 22, the coil member 88 is pressed in the tip direction (arrow X1 direction) by the balloon fixing member 74, and the base end of the coil member 88 is deformed so as to be displaced in the tip direction relative to the outer tube 24. In other words, the coil member 88 is formed to be compressible and deformable in its extension direction. That is, the coil member 88 elastically deforms in its extension direction. Between the adjacent winding parts 86, a space 89 is formed through which the balloon expansion fluid can flow in the state before the coil member 88 is compressed and deformed (the state in FIG. 2).

The cross-sectional shape of the wire 84 of the coil member 88 is formed in a rectangular shape. However, the cross-sectional shape of the wire 84 is not particularly limited, and may be a circle or a polygon (other than a rectangle). The outer diameter D1 (FIG. 3A) of the coil member 88 may be approximately the same as the outer diameter of the balloon fixing member 74, or may be smaller than the outer diameter of the balloon fixing member 74. If the outer diameter D1 of the coil member 88 is smaller than the outer diameter of the balloon fixing member 74, the pushing force is easily transmitted from the balloon fixing member 74 to the coil member 88.

In addition, it is preferable to make the gap between the outer peripheral surface of the coil member 88 and the inner peripheral surface 36 of the outer tube body 30 as narrow as possible in order to enhance the effect of suppressing the bending of the insertion part 90. As shown in FIG. 3A, the outer peripheral surface of the coil member 88 is partially in contact with the inner peripheral surface 36 of the outer tube body 30. That is, the outer diameter D1 of the coil member 88 is approximately the same as the shortest inner diameter of the outer tube body 30. Here, the shortest inner diameter of the outer tube body 30 is the inner diameter of the outer tube body 30 that passes through the line segment La in FIG. 3B (the short axis of the first lumen 34 of the outer tube body 30). In other words, the shortest inner diameter of the outer tube body 30 is the length of a line segment that is perpendicular to the flat surface 48 and passes through the center of the arc-shaped curved surface 46 (the center of the circle that passes through the curved surface 46), and both ends are located on the inner peripheral surface 36 of the outer tube body 30. However, the outer diameter D1 of the coil member 88 may be shorter than the shortest inner diameter of the outer tube body 30. In other words, the outer peripheral surface of the coil member 88 may be close to the curved surface 46 (or the flat surface 48) of the outer tube body 30.

In FIG. 3A, the inner diameter D2 of the coil member 88 is approximately the same as the outer diameter of the balloon 22 in an uninflated state. That is, the inner peripheral surface of the coil member 88 may be in contact with or close to the outer peripheral surface of the balloon 22 in an uninflated state. In addition, the inner diameter D2 of the coil member 88 is set to be less than three times the outer diameter D3 (see FIG. 5) of the portion of the balloon 22 that is in close contact with the outer peripheral surface of the insertion section 90 when the balloon 22 is inflated radially inward of the outer tube 24.

Examples of the material of the coil member 88 include resin materials and metal materials. Specifically, the coil member 88 is preferably made of PEEK resin, copper, copper alloy, aluminum, aluminum alloy, etc. When the coil member 88 is made of PEEK resin, the elastic force (the reaction force acting from the coil member 88 to the balloon fixing member 74) when the coil member 88 is compressed and deformed can be made relatively small. This makes it possible to prevent the inner tube 62 from retracting (moving in the direction of arrow X2) relative to the outer tube 24 due to the elastic force of the coil member 88.

Such a coil member 88 is formed, for example, by laser processing. However, the method of manufacturing the coil member 88 is not limited to laser processing, and may be a method of forming the wire 84 into a spiral shape, etc.

The coil member 88 extends over almost the entire length of the balloon 22. The free length L1 of the coil member 88 (the entire length of the coil member 88 when no load is applied) is preferably about 180 mm. The pitch P1 of the coil member 88 is preferably set to a width smaller than the tip diameter of the insertion section 90 of the endoscope 14, and is preferably 0.2 mm, for example. This reduces the occurrence of problems such as the tip of the insertion section 90 being pinched by the pitch P1 of the coil member 88 when operating the endoscope 14. The tight length of the coil member 88 (the length of the coil member 88 at maximum compression deformation) is preferably about 50 mm. The outer diameter D1 of the coil member 88 is preferably formed to be about 1.4 mm. The inner diameter D2 of the coil member 88 is preferably formed to be about 1.3 mm. However, the free length L1, pitch P1, tight length, outer diameter D1, and inner diameter D2 of the coil member 88 can be set appropriately.

The endoscope 14 is a fallopian tube scope for observing the fallopian tube 202. The endoscope 14 has a flexible insertion section 90 inserted into the second lumen 66 of the inner tube 62 of the balloon catheter 12 and the lumen 76 of the balloon 22. The insertion section 90 is formed, for example, from a resin material. Although detailed illustration is omitted, the insertion section 90 has a light-emitting unit that emits light, an imaging unit for imaging the fallopian tube 202 (see FIG. 4), and a covering member. The light-emitting unit includes a long light guide (optical fiber). The imaging unit includes a lens unit and an electrical unit (e.g., optical fiber, etc.) for transmitting the image formed by the lens unit.

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 the preparation step. Then, the user fixes the inner tube 62 with 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 slider 18 is slid relative to the outer tube 24 toward the tip of the outer tube 24 to straighten the tip side of the outer tube main body 30. At this time, the coil member 88 is not pressed toward the tip by the balloon fixing member 74.

Next, in the insertion step, the user inserts the balloon catheter 12 transcervically to the uterine fundus 200 (see FIG. 4). Then, in the sliding step, the slider 18 is pulled back relative to the outer tube 24 toward the base end of the outer tube 24. As a result, as shown in FIG. 4, the tip side of the outer tube main body 30 is exposed from the slider 18 and assumes a curved shape. At this time, the user positions the tip of the insertion section 90 of the endoscope 14 at the tip opening 54 of the outer tube 24 and confirms the tubal orifice 202a using the image captured by the endoscope 14.

Then, the user returns the insertion portion 90 of the endoscope 14 to the initial position (the position shown in FIG. 4), and then performs the balloon extraction process. Specifically, in the balloon extraction process, as shown in FIG. 5, a balloon expansion fluid is supplied to the first introduction port portion 56 (pressurization process). Then, the balloon expansion fluid is supplied from the first introduction port portion 56 through the outer lumen Sa to the outer space Sc of the balloon 22. The balloon expansion fluid supplied to the outer space Sc is guided to the outer peripheral surface of the balloon 22 through the space 89 between the adjacent winding portions 86 of the coil member 88. Therefore, the balloon 22 is elastically deformed by being pressed radially inward by the balloon expansion fluid supplied to the outer space Sc. In other words, the portion of the balloon 22 located on the outer peripheral side of the insertion portion 90 is in close contact with the outer peripheral surface of the insertion portion 90. The portions of the balloon 22 located on the tip side of the tip of the insertion portion 90 are in contact with each other on their inner surfaces.

Then, with the fixing screw 28 loosened, the user operates the inner tube hub 64 to advance the inner tube 62 relative to the outer tube 24 (advancement process). Then, as shown in FIG. 6, the balloon 22, which is pushed toward the distal end by the inner tube 62, advances together with the insertion portion 90 relative to the outer tube 24. In other words, the pushing force is transmitted from the inner tube 62 to the balloon 22, and the balloon 22 protrudes together with the insertion portion 90 from the distal end opening 54 of the outer tube 24 in the distal direction (the direction of the arrow X1).

In the forward movement process, one end of the balloon 22 is fixed to the tip of the outer tube 24, so the balloon 22 advances while its tip 22a (protruding end) is rolled back. That is, the balloon 22 is rolled back at its tip 22a (protruding end) so that the inner surface faces outward. Therefore, the balloon 22 advances a distance equivalent to half the advancement distance of the insertion section 90.

In addition, during the forward movement process, the coil member 88 is pressed toward the distal end by the balloon fixing member 74. As a result, the coil member 88 is compressed and deformed in its extension direction. This allows the inner tube 62 to slide smoothly toward the distal end relative to the outer tube 24. At this time, the space 89 between adjacent windings 86 in the coil member 88 gradually narrows.

Then, the user determines whether the balloon 22 has reached the lesion 204 based on the image captured by the endoscope 14. 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 72 (depressurization process). This allows perfusion fluid to flow between the balloon 22 and the insertion portion 90 of the endoscope 14 via the inner lumen Sb. Next, the user moves the endoscope 14 backward a predetermined distance as shown in FIG. 7 (retraction process). Thereafter, the pressurization process and advancement process described above are performed again.

As shown in FIG. 8, when the tip 22a of the balloon 22 comes into contact with the lesion 204 during the forward movement process, a relatively large axial compressive force acts on the balloon 22 when the user pushes the inner tube 62 in the distal direction. Such compressive force tends to be large when the lesion 204 is completely blocked. When a relatively large compressive force acts on the balloon 22, the balloon 22 and the insertion section 90 deform in a direction intersecting the axial direction, and are prone to buckling deformation.

However, because the coil member 88 is provided in the outer space Sc between the outer peripheral surface of the balloon 22 and the inner peripheral surface 36 of the outer tube body 30, the outer peripheral surface of the balloon 22 comes into contact with the inner peripheral surface of the coil member 88 before the balloon 22 and the insertion portion 90 are significantly deformed in a direction intersecting the axial direction. Therefore, buckling deformation of the insertion portion 90 is suppressed.

After that, as shown in FIG. 9, 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 72 while pulling the inner tube 62 to retract the balloon 22, and at the same time, operate the endoscope 14 to position it at the tip 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:

The balloon catheter 12 has a flexure suppression member 25 in the outer space Sc that extends around the balloon 22 in the circumferential direction. Therefore, when a relatively large axial compressive force acts on the balloon 22, the outer peripheral surface of the balloon 22 can be brought into contact with the flexure suppression member 25 before the balloon 22 and the insertion section 90 are significantly deformed in a direction intersecting the axial direction. This makes it possible to suppress buckling deformation of the insertion section 90.

A balloon fixing member 74 (pressing portion) for pressing the deflection suppression member 25 in the distal direction is provided at the distal end of the inner tube 62. When a pressing force is transmitted from the inner tube 62 to the balloon 22, the base end of the deflection suppression member 25 is pressed in the distal direction by the balloon fixing member 74, and is displaced in the distal direction relative to the outer tube 24.

This configuration allows the inner tube 62 to be smoothly moved toward the tip relative to the outer tube 24.

The outer diameter D1 of the deflection suppression member 25 (coil member 88) is approximately the same as the shortest inner diameter of the outer tube body 30.

With this configuration, the deflection suppression member 25 can effectively prevent the insertion section 90 from buckling.

The inner diameter D2 of the deflection suppression member 25 is approximately the same as the outer diameter of the balloon 22 in an uninflated state.

With this configuration, the deflection suppression member 25 can effectively prevent the insertion portion 90 from buckling.

The tip of the deflection suppression member 25 is fixed to the tip of the outer tube 24, and the deflection suppression member 25 is compressed and deformed by being pressed toward the tip by the balloon fixing member 74.

This configuration effectively prevents the insertion section 90 from buckling at the tip of the outer tube 24. In addition, compressing and deforming the deflection suppression member 25 allows the inner tube 62 to move smoothly in the tip direction relative to the outer tube 24.

The deflection suppression member 25 is a coil member 88 having a plurality of winding sections 86 in which wire 84 is wound in a spiral shape around the outer periphery of the balloon 22. Between adjacent winding sections 86, a space 89 is formed through which the balloon expansion fluid can flow before the coil member 88 is compressed and deformed.

With this configuration, the balloon expansion fluid can be guided to the outer surface of the balloon 22 through the space 89 between adjacent windings 86.

The inner tube 62 is provided with a rotation restriction portion 23 that is formed to protrude radially outward from the outer peripheral surface of the balloon 22 and contacts the inner peripheral surface 36 of the outer tube 24 to restrict circumferential rotation of the inner tube 62 relative to the outer tube 24.

With this configuration, the rotation restriction section 23 provided on the inner tube 62 restricts the rotation of the inner tube 62 relative to the outer tube 24, thereby suppressing twisting of the balloon 22.

Next, a balloon catheter 12A according to a modified example will be described with reference to Figures 10 and 11. 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 the description thereof will be omitted.

As shown in Figures 10 and 11, the balloon catheter 12A includes an outer catheter 16, a slider 18, an inner catheter 20, a balloon 22, a rotation restricting portion 23, and a deflection suppressing member 25a.

The deflection suppression member 25a is a tubular member 100 having an inner cavity into which the balloon 22 is inserted. The tubular member 100 is formed in a circular tube shape. The tip of the tubular member 100 is fixed to the tip of the outer tube 24 (the inner peripheral surface 36 of the tip of the outer tube main body 30). The base end of the tubular member 100 is in contact with the balloon fixing member 74. The base end of the tubular member 100 may or may not be fixed to the balloon fixing member 74. When a pushing force is transmitted from the inner tube 62 to the balloon 22, the tubular member 100 is pressed in the tip direction (arrow X1 direction) by the balloon fixing member 74, and the base end of the tubular member 100 is deformed so that it is displaced in the tip direction relative to the outer tube 24. In other words, the tubular member 100 is formed to be compressively deformable in its extension direction. In other words, the tubular member 100 elastically deforms in its extension direction.

The tubular member 100 is formed in a mesh or sponge shape. In other words, the tubular member 100 has holes 102 formed therein for directing the balloon expansion fluid supplied to the outer space Sc to the outer peripheral surface of the balloon 22. The length of the tubular member 100 before compressive deformation is set to be the same as the free length L1 of the coil member 88. The length of the tubular member 100 at maximum compressive deformation is set to be the same as the tight length of the coil member 88. The outer diameter and inner diameter of the tubular member 100 are set to be the same as the outer diameter D1 and inner diameter D2 of the coil member 88.

In this modified example, the deflection suppression member 25a is a tubular member 100 having an inner cavity into which the balloon 22 is inserted.

With this configuration, the buckling deformation of the insertion section 90 can be suppressed by the tubular member 100.

The tubular member 100 has holes 102 formed therein for directing the balloon expansion fluid supplied to the outer space Sc to the outer peripheral surface of the balloon 22.

This configuration allows the balloon 22 to be efficiently inflated with the balloon expansion fluid.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

The deflection suppression member may be a tubular member formed into a bellows shape.

The above embodiments can be summarized as follows:

The above embodiment is a balloon catheter (12, 12A) having a flexible outer tube (24), an inner tube (62) disposed in the inner cavity (34) of the outer tube so as to be movable in the axial direction relative to the outer tube, and a tubular balloon (22) that connects the tip of the outer tube to the tip of the inner tube and expands radially inwardly of the outer tube, and an outer space (Sc) is formed between the outer peripheral surface of the balloon and the inner peripheral surface (36) of the outer tube, through which a balloon expansion fluid for inflating the balloon flows, The balloon is inflated with the balloon expansion fluid and supported by the linear insertion portion (90) of the medical device (14). When a pushing force toward the distal end is transmitted from the inner tube to the balloon, the distal end of the balloon is rolled back and protrudes from the distal opening (54) of the outer tube in the distal direction, and a bending suppression member (25, 25a) is provided in the outer space, extending around the balloon in the circumferential direction. This discloses a balloon catheter.

In the above balloon catheter, a pressing portion (74) for pressing the deflection suppression member in the distal direction is provided at the distal end of the inner tube, and the base end of the deflection suppression member may be displaced in the distal direction relative to the outer tube by being pressed in the distal direction by the pressing portion when the pressing force is transmitted from the inner tube to the balloon.

In the above balloon catheter, the outer diameter (D1) of the deflection suppression member may be approximately the same as the shortest inner diameter of the outer tube body 30.

In the above balloon catheter, the inner diameter (D2) of the deflection suppression member may be approximately the same as the outer diameter of the balloon in an uninflated state.

In the balloon catheter described above, the tip of the deflection suppression member may be fixed to the tip of the outer tube, and the deflection suppression member may be compressed and deformed by being pressed toward the tip by the pressing portion.

In the above-mentioned balloon catheter, the deflection suppression member is a coil member (88) having a plurality of winding sections (86) in which a wire (84) is wound helically around the outer periphery of the balloon, and a space (89) through which the balloon expansion fluid can flow may be formed between adjacent winding sections before the coil member is compressed and deformed.

In the above balloon catheter, the deflection suppression member may be a tubular member (100) having an inner cavity into which the balloon is inserted.

In the above balloon catheter, the tubular member may be formed with a hole (102) for directing the balloon inflation fluid supplied to the outer space to the outer circumferential surface of the balloon.

In the above balloon catheter, the inner tube may be provided with a rotation restricting portion (23) that protrudes radially outward from the outer circumferential surface of the balloon and restricts circumferential rotation of the inner tube relative to the outer tube by contacting the inner circumferential surface of the outer tube.

The above embodiment discloses a catheter system (10) that includes the above-mentioned balloon catheter and the medical device.

In the above catheter system, the medical device may be an endoscope.

REFERENCE SIGNS LIST 10: Catheter system 12, 12A: Balloon catheter 14: Endoscope (medical device) 22: Balloon 23: Rotation restriction portion 24: Outer tube 25, 25a: Deflection suppression member 30: Outer tube main body 34: First lumen 54: Tip opening 62: Inner tube 74: Balloon fixing member (pressing portion)
84: wire 86: winding portion 88: coil member 89: space 90: insertion portion 100: tubular member 102: hole Sc: outer space

Claims (11)

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 relative to the outer tube; and a tubular balloon connecting a distal end of the outer tube with a distal end of the inner tube and inflating radially inward of the outer tube,
an outer space through which a balloon expansion fluid for inflating the balloon flows is formed between an outer peripheral surface of the balloon and an inner peripheral surface of the outer tube;
a distal end of the balloon is turned up and protrudes from the distal end opening of the outer tube in the distal direction when a pushing force in the distal direction is transmitted from the inner tube to the balloon in a state in which the balloon is inflated with the balloon inflation fluid and supported by the linear insertion portion of the medical device;
A balloon catheter, wherein the outer space is provided with a bending suppression member extending in a circumferential direction of the balloon so as to go around the balloon. 2. The balloon catheter according to claim 1,
a pressing portion for pressing the deflection suppression member in the distal direction is provided at the distal end portion of the inner tube,
A balloon catheter, wherein the base end of the bending restraint member is displaced in the distal direction relative to the outer tube by being pressed in the distal direction by the pressing portion when the pushing force is transmitted from the inner tube to the balloon. 3. The balloon catheter according to claim 1,
A balloon catheter, wherein the outer diameter of the bending suppression member is approximately the same as the shortest inner diameter of the outer tube. The balloon catheter according to any one of claims 1 to 3,
A balloon catheter, wherein the inner diameter of the deflection suppression member is approximately the same as the outer diameter of the balloon in an uninflated state. The balloon catheter according to claim 2,
a tip end portion of the deflection suppression member is fixed to the tip end portion of the outer tube,
The deflection suppression member is compressed and deformed by being pressed in the distal end direction by the pressing portion. The balloon catheter according to claim 5,
the deflection suppression member is a coil member having a plurality of winding portions formed by winding a wire in a spiral shape around an outer circumferential surface of the balloon,
a space through which the balloon inflation fluid can flow is formed between the adjacent wound portions before the coil member is compressed and deformed. The balloon catheter according to any one of claims 1 to 6,
A balloon catheter, wherein the deflection suppression member is a tubular member having an inner cavity into which the balloon is inserted. The balloon catheter according to claim 7,
A balloon catheter, wherein the tubular member has a hole formed therein for directing the balloon inflation fluid supplied to the outer space to the outer peripheral surface of the balloon. The balloon catheter according to any one of claims 1 to 8,
A balloon catheter, wherein the inner tube is provided with a rotation regulating portion that is formed so as to protrude radially outward from the outer peripheral surface of the balloon and that contacts the inner peripheral surface of the outer tube to regulate circumferential rotation of the inner tube relative to the outer tube. A balloon catheter according to any one of claims 1 to 9,
A catheter system comprising the medical device. 11. The catheter system of claim 10,
A catheter system, wherein the medical device is an endoscope.

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