Balloon catheter

Abstract

  A balloon catheter according to the present disclosure includes: a tubular member having a longitudinal axis; a balloon that is continuous with a distal side of the tubular member in a longitudinal axis direction and expandable and contractible in a radial direction about the longitudinal axis, the balloon including, in an expanded state, a light-transmitting window portion extending over a predetermined angular range that does not cover an entire region in a circumferential direction around the longitudinal axis; and a marker portion indicating a position of the light-transmitting window portion in the circumferential direction.Figure 2

Description

DESCRIPTIONTitle of InventionBALLOON CATHETER Technical Field

[0001] The present disclosure relates to a balloon catheter.Background Art

[0002] Conventionally, balloon catheters used to irradiate abnormal tissue with therapeutic light have been known. Patent Literature 1 discloses this type of balloon catheter. The balloon catheter of Patent Literature 1 includes a balloon having a defined treatment window and is used by inserting an optical fiber cable into a central channel. Citation ListPatent Literature

[0003] Patent Literature 1: JP 2005-46640 A Summary of InventionTechnical Problem

[0004] In a procedure performed using the balloon catheter of Patent Literature 1, the balloon may be expanded after the balloon catheter is inserted into a living body with the balloon in a contracted state. Here, in the balloon catheter of Patent Literature 1, the treatment window serving as a light-transmitting window portion may extend over a predetermined angular range that does not cover an entire region in a circumferential direction around a longitudinal axis of a tubular member defining the central channel. In this case, before expanding the balloon, a circumferential position of the light-transmitting window portion is preferably aligned in advance with a position of an irradiation target such as a lesion. However, when the balloon is in a contracted state or when the balloon is inserted into a living body, confirming the circumferential position of the light-transmitting window portion is difficult.

[0005] An object of the present disclosure is to provide a balloon catheter with which a circumferential position of a light-transmitting window portion can be confirmed even when a balloon is in a contracted state or when the balloon is inserted into a living body. Solution to Problem

[0006] A balloon catheter according to a first aspect of the present disclosure is a balloon catheter including: (1) a tubular member having a longitudinal axis; a balloon that is continuous with a distal side of the tubular member in a longitudinal axis direction, is expandable and contractible in a radial direction about the longitudinal axis, and includes, in an expanded state, a light-transmitting window portion extending over a predetermined angular range that does not cover an entire region in a circumferential direction around the longitudinal axis; and a marker portion indicating a position of the light-transmitting window portion in the circumferential direction.

[0007] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to (1) above, in which (2) the marker portion is a cutout portion formed by cutting out a part, in the circumferential direction, of the tubular member or of a separate member attached to the tubular member.

[0008] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to (2) above, in which (3) a maximum value of a cutout angle of the cutout portion in the circumferential direction substantially coincides with the predetermined angular range of the light-transmitting window portion.

[0009] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to (2) or (3) above, in which (4) an outline of the cutout portion in a front view as viewed from the radial direction is substantially the same as an outline of the light-transmitting window portion in a front view as viewed from the radial direction.

[0010] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to any one of (2) to (4) above, in which (5) the cutout portion differs from a portion of the tubular member other than the cutout portion or a portion of the separate member other than the cutout portion in at least one of hue, saturation, and brightness.

[0011] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to any one of (1) to (5) above, in which (6) the marker portion is disposed at a distal end portion of the tubular member in the longitudinal axis direction.

[0012] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to any one of (1) to (6) above, in which (7) when the marker portion is a first marker portion, the balloon catheter includes a second marker portion that is disposed at a position different from the first marker portion in the circumferential direction and is distinguishable from the first marker portion.

[0013] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to any one of (1) to (7) above, in which (8) the light-transmitting window portion of the balloon extends substantially parallel or parallel to the longitudinal axis direction.

[0014] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to any one of (1) to (8) above, in which (9) the balloon includes a visual recognition window portion disposed on a proximal side in the longitudinal axis direction of the light-transmitting window portion and spaced apart from the light-transmitting window portion.

[0015] A balloon catheter according to one embodiment of the present disclosure is the balloon catheter according to (9) above, in which (10) the visual recognition window portion extends with a greater inclination than the light-transmitting window portion with respect to the longitudinal axis direction. Advantageous Effects of Invention

[0016] According to the present disclosure, it is possible to provide a balloon catheter with which a circumferential position of a light-transmitting window portion can be confirmed even when a balloon is in a contracted state or when the balloon is inserted into a living body. Brief Description of Drawings

[0017] [Fig. 1] Fig. 1 is a diagram illustrating an example of an endoscope system including a balloon catheter according to one embodiment of the present disclosure. [Fig. 2] Fig. 2 is a perspective view illustrating the vicinity of a balloon of the balloon catheter illustrated in Fig. 1. [Fig. 3] Fig. 3 is a cross-sectional view illustrating the vicinity of the balloon of the balloon catheter illustrated in Fig. 1 in a cross section that passes through a longitudinal axis of a tubular member and is parallel to a longitudinal axis direction. [Fig. 4A] Fig. 4A is a cross-sectional view taken along line I-I in Fig. 3. [Fig. 4B] Fig. 4B is a cross-sectional view taken along line II-II in Fig. 3. [Fig. 5A] Fig. 5A is a diagram illustrating one modification of a cutout portion. [Fig. 5B] Fig. 5B is a diagram illustrating one modification of the cutout portion. [Fig. 5C] Fig. 5C is a diagram illustrating one modification of the cutout portion. [Fig. 6A] Fig. 6A is a diagram illustrating one modification of the balloon catheter. [Fig. 6B] Fig. 6B is a diagram illustrating one modification of the balloon catheter. [Fig. 6C] Fig. 6C is a diagram illustrating one modification of the balloon catheter. [Fig. 7] Fig. 7 is a diagram illustrating one modification of the cutout portion. [Fig. 8A] Fig. 8A is a perspective view illustrating one modification of the tubular member. [Fig. 8B] Fig. 8B is a plan view of the tubular member illustrated in Fig. 8A as viewed from the radial direction. [Fig. 9] Fig. 9 is a diagram illustrating one modification of the cutout portion. Description of Embodiments

[0018] Hereinafter, embodiments of a balloon catheter according to the present disclosure will be described by way of example with reference to the drawings. In the drawings, the same reference signs are assigned to the same configurations.

[0019] Fig. 1 is a diagram illustrating an example of an endoscope system 100 including a balloon catheter 1 as one embodiment of the balloon catheter according to the present disclosure. The endoscope system 100 illustrated in Fig. 1 includes an endoscope device 101, a control device 102 connected to the endoscope device 101, a display unit 103 such as a monitor connected to the control device 102, a light source device 104 that supplies light such as therapeutic light and an aiming beam, a fluid supply tool 105, and the balloon catheter 1. In the endoscope device 101, a treatment instrument channel through which the balloon catheter 1 serving as a treatment instrument can be inserted is defined. As illustrated in Fig. 1, the balloon catheter 1 is inserted through the treatment instrument channel of the endoscope device 101 and delivered to a lesion in a lumen such as a living body lumen. The control device 102 includes a light source section 102a that supplies illumination light to the endoscope device 101 and a processor section 102b that performs various types of image processing on an imaging signal from the endoscope device 101 and converts the imaging signal into a video signal. In addition, the control device 102 may include an input unit such as a keyboard. The display unit 103 is capable of displaying a captured image of the endoscope device 101 based on the video signal generated by the processor section 102b of the control device 102. The fluid supply tool 105 is capable of supplying a fluid to a fluid containing space 30a of a balloon 30 described later.

[0020] The balloon catheter 1 can be used, for example, for treatment by photodynamic therapy (PDT) and treatment by photoimmunotherapy (PIT). The balloon catheter 1 can be inserted into a lumen such as a living body lumen. The balloon catheter 1 may be used together with the endoscope device 101, as illustrated in Fig. 1. In addition, a lumen into which the balloon catheter 1 can be inserted is not particularly limited. As illustrated in Fig. 1, the balloon catheter 1 may be used, for example, for treatment of cancer of a luminal organ through the treatment instrument channel of the endoscope device 101 inserted into a luminal organ such as a digestive tract (esophagus, stomach, small intestine, large intestine, or the like), a urinary tract, or a blood vessel.

[0021] As illustrated in Fig. 1, the balloon catheter 1 includes an insertion portion 1a inserted into a living body and a proximal operation portion 1b operated outside the living body. The insertion portion 1a includes a tubular member 10, the balloon 30, and a marker portion 50.

[0022] The tubular member 10 has a longitudinal axis O. The balloon catheter 1 can be inserted into and removed from a living body along the longitudinal axis O of the tubular member 10. Hereinafter, for convenience of description, a direction along the longitudinal axis O is referred to as a “longitudinal axis direction A”. In addition, a side on which the insertion portion 1a of the balloon catheter 1 is located in the longitudinal axis direction A is referred to as a “distal side” or a “distal side in the longitudinal axis direction A”, and a side on which the proximal operation portion 1b of the balloon catheter 1 is located in the longitudinal axis direction A is referred to as a “proximal side” or a “proximal side in the longitudinal axis direction A”. Furthermore, a direction around the longitudinal axis O is referred to as a “circumferential direction B”. Furthermore, a radial direction of an imaginary circle centered on the longitudinal axis O is referred to as a “radial direction C”.

[0023] Fig. 2 is a perspective view illustrating the vicinity of the balloon 30 of the balloon catheter 1. Fig. 3 is a cross-sectional view of the balloon catheter 1 illustrating the vicinity of the balloon 30. More specifically, Fig. 3 is a cross-sectional view of the balloon catheter 1 illustrating the vicinity of the balloon 30 in a cross section that passes through the longitudinal axis O of the tubular member 10 and is parallel to the longitudinal axis direction A. Fig. 4A is a cross-sectional view taken along line I-I in Fig. 3. In addition, Fig. 4B is a cross-sectional view taken along line II-II in Fig. 3.

[0024] As illustrated in Figs. 2 and 3, the tubular member 10 defines, inside the tubular member 10, an insertion passage 10a into which a light irradiation body 201 can be inserted. The light irradiation body 201 may include a light irradiation portion 200 that emits light toward the outside in the radial direction C and a light transmission member 202, such as an optical fiber, that transmits light such as therapeutic light and an aiming beam from the light source device 104 (see Fig. 1) to the light irradiation portion 200. In the light irradiation body 201 of the present embodiment, the light irradiation portion 200 is attached to a distal end of the light transmission member 202. The light irradiation body 201 is separate from the balloon catheter 1. In addition, the balloon catheter 1 may include, on the inside of the tubular member 10 in the radial direction C, an inner tube having a lumen into which the light irradiation body 201 can be inserted. In such a case, the light irradiation body 201 may be inserted into the lumen of the inner tube instead of the insertion passage 10a. The tubular member 10 and the inner tube may be disposed concentrically. The inner tube may extend distally beyond the tubular member 10. The inner tube may extend proximally beyond the tubular member 10. In the case of such a configuration, a gap between an outer surface of the inner tube and an inner surface of the tubular member 10 may be defined as an inflation lumen serving as a flow path for supplying a fluid to or discharging a fluid from the fluid containing space 30a.

[0025] The intensity and wavelength of light emitted from the light irradiation portion 200 may be appropriately selected depending on, for example, the type of a drug used in combination, the state of a lesion, the position of the lesion, and the like. The light emitted from the light irradiation portion 200 may be, for example, visible light such as near-infrared light having a wavelength near 690 nm.

[0026] The insertion passage 10a extends along the longitudinal axis direction A. The insertion passage 10a of the present embodiment penetrates the tubular member 10 in the longitudinal axis direction A. The insertion passage 10a is continuous, through a distal-side opening, with a fluid containing space 30a of the balloon 30 described later. Therefore, in the balloon catheter 1 of the present embodiment, the light irradiation body 201 can be inserted from a proximal-side opening of the insertion passage 10a, through the distal-side opening of the insertion passage 10a, and into the fluid containing space 30a of the balloon 30 described later.

[0027] An outer shape of a cross section of the tubular member 10 of the present embodiment orthogonal to the longitudinal axis direction A is circular. However, the outer shape of the cross section of the tubular member 10 orthogonal to the longitudinal axis direction A is not particularly limited and may be, for example, an oval shape such as an elliptical shape. In addition, an outer shape of a cross section of the insertion passage 10a of the present embodiment orthogonal to the longitudinal axis direction A is circular. However, the outer shape of the cross section of the insertion passage 10a orthogonal to the longitudinal axis direction A is not particularly limited and may be, for example, an oval shape such as an elliptical shape.

[0028] A material forming the tubular member 10 is not particularly limited, and examples include various resin materials such as polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymer; ethylene-vinyl acetate copolymer (EVA); polyvinyl chloride; polyvinylidene chloride; polystyrene; polyamide; polyamide elastomer; polyimide; polyamide-imide; polycarbonate; poly-(4-methylpentene-1); ionomer; acrylic resin; polymethyl methacrylate; acrylonitrile-butadiene-styrene copolymer (ABS resin); acrylonitrile-styrene copolymer (AS resin); butadiene-styrene copolymer; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polycyclohexane terephthalate (PCT); polyether; polyether ketone (PEK); polyether ether ketone (PEEK); polyetherimide; polyacetal (POM); polyphenylene oxide; modified polyphenylene oxide; polysulfone; polyethersulfone; polyphenylene sulfide; polyarylate; aromatic polyester (liquid crystal polymer); polytetrafluoroethylene, polyvinylidene fluoride, and other fluorine-based resins. In addition, the material forming the tubular member 10 may be a blend including two or more types of these materials. Furthermore, the tubular member 10 may be formed from a metal material.

[0029] The balloon 30 is continuous with the distal side of the tubular member 10 in the longitudinal axis direction A. The balloon 30 is configured to be expandable and contractible in the radial direction C. The balloon 30 of the present embodiment defines the fluid containing space 30a inside the balloon 30. The fluid containing space 30a of the present embodiment is continuous with the insertion passage 10a of the tubular member 10. Therefore, in the balloon catheter 1 of the present embodiment, supply of a fluid to the fluid containing space 30a and discharge of the fluid from the fluid containing space 30a can be performed through the insertion passage 10a. The balloon 30 of the present embodiment is expandable outward in the radial direction C by supplying a fluid to the fluid containing space 30a. In addition, the balloon 30 of the present embodiment is contractible inward in the radial direction C by discharging the fluid from the fluid containing space 30a. Figs. 2 and 3 illustrate the balloon 30 in an expanded state. The fluid supplied to the fluid containing space 30a may be, for example, a liquid such as physiological saline or may be a gas such as air. The balloon 30 of the present embodiment has, in the expanded state, a central axis substantially coinciding with the longitudinal axis O of the tubular member 10.

[0030] The balloon 30 is configured to accommodate the light irradiation portion 200 inside the balloon 30. Specifically, the balloon 30 of the present embodiment is capable of accommodating the light irradiation portion 200 in the fluid containing space 30a serving as an internal space.

[0031] The balloon 30 of the present embodiment includes an expandable main body portion 34 that is expandable and contractible in the radial direction C, a proximal tubular portion 35 that is continuous with a proximal side of the expandable main body portion 34 and is fixed to the tubular member 10, and a distal tubular portion 36 that is continuous with a distal side of the expandable main body portion 34.

[0032] As illustrated in Figs. 2 and 3, the expandable main body portion 34 of the present embodiment includes, in an expanded state, a central portion 41, a proximal reduced-diameter portion 42, and a distal reduced-diameter portion 43. The central portion 41 is substantially cylindrical and has a side surface formed substantially parallel to the longitudinal axis direction A in a cross section parallel to the longitudinal axis direction A. The proximal reduced-diameter portion 42 is continuous with a proximal side of the central portion 41 in the longitudinal axis direction A and decreases in diameter so as to approach the longitudinal axis O toward the proximal side in the longitudinal axis direction A. The distal reduced-diameter portion 43 is continuous with a distal side of the central portion 41 in the longitudinal axis direction A and decreases in diameter so as to approach the longitudinal axis O toward the distal side in the longitudinal axis direction A. The proximal reduced-diameter portion 42 and the distal reduced-diameter portion 43 of the present embodiment can be configured in a hemispherical shape. However, the shapes of the proximal reduced-diameter portion 42 and the distal reduced-diameter portion 43 are not limited to hemispherical shapes and may be, for example, conical shapes.

[0033] The proximal tubular portion 35 is continuous with the proximal reduced-diameter portion 42 of the expandable main body portion 34. The proximal tubular portion 35 does not expand or contract in the radial direction C. The proximal tubular portion 35 is fixed to the tubular member 10 so as to cover the outside, in the radial direction C, of the distal end portion 11 of the tubular member 10. Specifically, an inner surface of the proximal tubular portion 35 is fixed to an outer surface of the distal end portion 11 of the tubular member 10 by adhesion or the like.

[0034] In addition, the distal end portion 11 of the tubular member 10 of the present embodiment is formed by a small-diameter portion 12b having an outer diameter smaller than that of a proximal-side main tube portion 12a. In other words, in the tubular member 10, an annular step is formed between an outer surface of the main tube portion 12a and an outer surface of the small-diameter portion 12b. The proximal tubular portion 35 of the balloon 30 of the present embodiment is joined onto the outer surface of the small-diameter portion 12b serving as the distal end portion 11 of the tubular member 10. A surface of the proximal tubular portion 35 on the outside in the radial direction C is preferably located inward, in the radial direction C, of the outer surface of the main tube portion 12a of the tubular member 10. In addition, the surface of the proximal tubular portion 35 on the outside in the radial direction C is more preferably configured to be flush with the outer surface of the main tube portion 12a of the tubular member 10 so that the above-described step is not formed. By preventing the proximal tubular portion 35 from projecting outward in the radial direction C from the outer surface of the main tube portion 12a of the tubular member 10 in this manner, catching of a proximal end surface of the proximal tubular portion 35 on living tissue or on a medical instrument such as the endoscope device 101 used together with the balloon catheter 1 can be suppressed when the balloon catheter 1 moves distally in the longitudinal axis direction A. The proximal tubular portion 35 is preferably configured so as not to project outward in the radial direction C from the outer surface of the main tube portion 12a of the tubular member 10; however, the outer surface of the proximal tubular portion 35 may project outward in the radial direction C from the outer surface of the main tube portion 12a as long as catching of the balloon catheter 1 does not occur when the balloon catheter 1 is inserted into and removed from a medical instrument such as the endoscope device 101. In addition, the distal end portion 11 of the tubular member 10 may be fixed to the balloon 30 so as to cover the outside, in the radial direction C, of the proximal tubular portion 35 of the balloon 30. In such a case, a proximal end portion of the proximal tubular portion 35 of the balloon 30 may be configured as a small-diameter portion having an outer diameter smaller than that of a distal-side portion of the proximal tubular portion 35. In addition, the distal end portion 11 of the tubular member 10 may be joined onto an outer surface of this small-diameter portion. The tubular member 10 and the balloon 30 are preferably configured so that the above-described step is not formed between a surface of the distal end portion 11 of the tubular member 10 on the outside in the radial direction C and the outer surface of the proximal tubular portion 35 of the balloon 30.

[0035] The distal tubular portion 36 is continuous with the distal reduced-diameter portion 43 of the expandable main body portion 34. The distal tubular portion 36 does not expand or contract in the radial direction C. A distal end of the fluid containing space 30a of the present embodiment is closed by a closing wall 36a serving as a distal end portion of the distal tubular portion 36.

[0036] As illustrated in Figs. 2 and 3, the balloon 30 includes, in the expanded state, a light-transmitting window portion 31 and a light blocking portion 32. The light-transmitting window portion 31 of the present embodiment is disposed in the expandable main body portion 34 of the balloon 30. Specifically, the light-transmitting window portion 31 of the present embodiment is disposed only in the central portion 41 of the expandable main body portion 34. Therefore, the light-transmitting window portion 31 of the present embodiment extends substantially parallel or parallel to the longitudinal axis direction A. However, the arrangement of the light-transmitting window portion 31 is not limited, and the light-transmitting window portion 31 may be disposed, for example, so as to straddle the central portion 41 and either one of the proximal reduced-diameter portion 42 and the distal reduced-diameter portion 43, or may be disposed so as to straddle the central portion 41 and both the proximal reduced-diameter portion 42 and the distal reduced-diameter portion 43.

[0037] The light-transmitting window portion 31 extends over a predetermined angular range that does not cover an entire region in the circumferential direction B. In other words, the light-transmitting window portion 31 is provided only in a part of the balloon 30 in the circumferential direction B. The predetermined angular range of the light-transmitting window portion 31 of the present embodiment in the circumferential direction B is 180 degrees. The predetermined angular range of the light-transmitting window portion 31 in the circumferential direction B means a maximum value of an angle θ1 defined by two straight lines L1 and L2 connecting both ends 33a and 33b of the light-transmitting window portion 31 in the circumferential direction B to the longitudinal axis O when cross sections of the balloon 30 parallel to the radial direction C are viewed along the longitudinal axis direction A (see Fig. 4A). The angle θ1 of the light-transmitting window portion 31 of the present embodiment is substantially constant regardless of the position of the light-transmitting window portion 31 in the longitudinal axis direction A. Therefore, the predetermined angular range of the light-transmitting window portion 31 of the present embodiment in the circumferential direction B is the angle θ1 at any position of the light-transmitting window portion 31 in the longitudinal axis direction A.

[0038] The light-transmitting window portion 31 is configured to transmit light emitted from the light irradiation portion 200 inserted inside the balloon 30 toward the outside in the radial direction C. On the other hand, a transmittance of the light blocking portion 32 for light from the light irradiation portion 200 of the light irradiation body 201 toward the outside in the radial direction C is smaller than a transmittance of the light-transmitting window portion 31 for light from the light irradiation portion 200 of the light irradiation body 201 toward the outside in the radial direction C.

[0039] The light blocking portion 32 is provided in regions of the balloon 30 other than the light-transmitting window portion 31 and a visual recognition window portion 33 described later. More specifically, the light blocking portion 32 is disposed adjacent to the light-transmitting window portion 31 in the longitudinal axis direction A and the circumferential direction B.

[0040] In the present embodiment, the light-transmitting window portion 31 and the light blocking portion 32 of the balloon 30 are formed by stacking of a base body 45 and a coating layer 46. Specifically, the balloon 30 of the present embodiment includes the base body 45 and the coating layer 46 coated on an outer surface of the base body 45. The base body 45 is formed of a light-transmitting material capable of transmitting, toward the outside in the radial direction C, light from the light irradiation portion 200 inserted in the insertion passage 10a. The coating layer 46 is formed of a light-transmission limiting material having a transmittance for light toward the outside in the radial direction C from the light irradiation portion 200 inserted in the insertion passage 10a that is smaller than a transmittance of the base body 45. In the light-transmitting window portion 31 of the balloon 30 of the present embodiment, the base body 45 is not covered by the coating layer 46, and the light-transmitting window portion 31 is formed only of the base body 45. In contrast, in the light blocking portion 32 of the balloon 30 of the present embodiment, the base body 45 is covered by the coating layer 46, and the light blocking portion 32 is formed by the base body 45 and the coating layer 46.

[0041] In other words, the light-transmitting window portion 31 of the balloon 30 of the present embodiment is a light-transmitting portion 2a in which the base body 45 is not covered by the coating layer 46. In addition, the light blocking portion 32 of the balloon 30 of the present embodiment is a light-transmission limiting portion 2b in which the base body 45 is covered by the coating layer 46.

[0042] The balloon 30 of the present embodiment includes, in the expanded state, the visual recognition window portion 33 disposed on the proximal side in the longitudinal axis direction A of the light-transmitting window portion 31 and spaced apart from the light-transmitting window portion 31. More specifically, the visual recognition window portion 33 of the present embodiment is disposed on the proximal side of the light-transmitting window portion 31, with the light blocking portion 32 interposed therebetween, and is spaced apart from the light-transmitting window portion 31. The visual recognition window portion 33 of the present embodiment is, similarly to the light-transmitting window portion 31, the light-transmitting portion 2a in which the base body 45 is not covered by the coating layer 46. By including such a visual recognition window portion 33, an operator can visually recognize a visual recognition target such as a lesion through the visual recognition window portion 33 and the light-transmitting window portion 31 by using the endoscope device 101, even in a state in which the balloon catheter 1 is inserted into a living body. This facilitates alignment of the position of the light-transmitting window portion 31 of the balloon 30 with the position of an irradiation target in the longitudinal axis direction A and the circumferential direction B in a state in which the balloon catheter 1 is inserted into a living body.

[0043] The visual recognition window portion 33 of the present embodiment is disposed only in the proximal reduced-diameter portion 42. Therefore, the visual recognition window portion 33 of the present embodiment extends with a greater inclination than the light-transmitting window portion 31 with respect to the longitudinal axis direction A. However, the arrangement of the visual recognition window portion 33 is not limited, and the visual recognition window portion 33 may be disposed, for example, so as to straddle the central portion 41 and the proximal reduced-diameter portion 42. In addition, although the visual recognition window portion 33 of the present embodiment is disposed over an entire region of the balloon 30 in the circumferential direction B, the visual recognition window portion 33 may be disposed only in a part of the balloon 30 in the circumferential direction B.

[0044] The coating layer 46 of the present embodiment may be, for example, a coating material coated on the outer surface of the base body 45, and the method for applying the coating material to the outer surface of the base body 45 is not particularly limited. The coating material constituting the coating layer 46 may be applied to the outer surface of the base body 45 by, for example, a dipping method, a spray coating method, a roll coating method, a screen printing method, a vacuum deposition method, a low-vacuum sputtering method, or the like.

[0045] The base body 45 of the present embodiment is formed of a transparent resin material. In this manner, the base body 45 may be formed of a transparent resin material serving as a light-transmitting material. Examples of the resin material constituting the base body 45 include polyethylene terephthalate (PET), polyurethane, polyamide, polyamide elastomer, and the like. The base body 45 may be formed of a single layer of a transparent resin material or may be a laminate in which a plurality of layers of transparent resin materials are stacked.

[0046] The constituent material of the coating layer 46 is not particularly limited, and various metal materials such as titanium oxide, barium sulfate, zinc oxide, silver, and aluminum can be used, for example. In addition, the coating layer 46 may be a resin containing particles of a metal material as described above, a pigment such as carbon black, or a dye.

[0047] The proximal tubular portion 35 of the present embodiment is formed of a transparent resin material. Specifically, the proximal tubular portion 35 of the present embodiment is configured as the light-transmitting portion 2a in which the base body 45 is not covered by the coating layer 46. Therefore, in the balloon of the present embodiment, the distal end portion 11 and the marker portion 50 of the tubular member 10, which are covered on the outside in the radial direction C by the proximal tubular portion 35, can be visually recognized through the proximal tubular portion 35. In the present embodiment, the distal tubular portion 36 is also configured as the light-transmitting portion 2a similarly to the proximal tubular portion 35.

[0048] In the balloon of the present embodiment, all regions other than the light-transmitting window portion 31, the visual recognition window portion 33, the proximal tubular portion 35, and the distal tubular portion 36 are the light-transmission limiting portion 2b in which the base body 45 is covered by the coating layer 46. However, the balloon 30 is not limited to this configuration, and may include, for example, the light-transmitting portion 2a in which the base body 45 is not covered by the coating layer 46 in regions other than the light-transmitting window portion 31, the visual recognition window portion 33, the proximal tubular portion 35, and the distal tubular portion 36.

[0049] The marker portion 50 indicates the position of the light-transmitting window portion 31 in the circumferential direction B. Details of the marker portion 50 will be described later.

[0050] Next, one example of a method of using the balloon catheter 1 will be described. First, the light irradiation body 201 is inserted into the insertion passage 10a of the tubular member 10 of the balloon catheter 1 toward the distal side in the longitudinal axis direction A, and the light irradiation portion 200 is disposed at a predetermined position in the balloon 30. The predetermined position is, for example, a position at which the light irradiation portion 200 is disposed so as to overlap with an entire region of the light-transmitting window portion 31 in the longitudinal axis direction A. In this state, the balloon 30 of the balloon catheter 1 is in a contracted state.

[0051] Thereafter, both the balloon catheter 1 and the light irradiation body 201 inserted into the balloon catheter 1 are inserted into a living body through the treatment instrument channel of the endoscope device 101. At this time, the position of the light-transmitting window portion 31 of the balloon 30 is aligned, in the longitudinal axis direction A and the circumferential direction B, with a position serving as an irradiation target such as a lesion formed in living tissue defining a lumen. Alignment with the position serving as the irradiation target in the longitudinal axis direction A and the circumferential direction B is performed for one or both of the directions as necessary. Alignment in the longitudinal axis direction A is performed by moving the balloon catheter 1 distally or proximally in the longitudinal axis direction A. Alignment in the circumferential direction B is performed by rotating the balloon catheter 1 in the circumferential direction B. Alignment in the circumferential direction B may be performed when the balloon 30 of the balloon catheter 1 is brought into a first expanded state in which the balloon 30 is expanded by being adjusted, from the contracted state, to a first expansion amount, which is an expansion amount such that the balloon 30 does not contact an inner wall of an irradiation target such as a lesion and the irradiation target such as a lesion or such that the balloon 30 lightly contacts the inner wall and the irradiation target. More specifically, alignment with an irradiation target such as a lesion may be performed while observing the light-transmitting window portion 31 of the balloon 30 in the first expanded state via the visual recognition window portion 33.

[0052] Thereafter, the balloon 30 is expanded from the contracted state and brought into the expanded state, thereby bringing the light-transmitting window portion 31 close to or into close contact with the irradiation target such as a lesion. When the balloon 30 is brought into the first expanded state, the balloon 30 is adjusted to a second expansion amount larger than the first expansion amount and expanded, and is brought into a second expanded state in which the light-transmitting window portion 31 is brought close to or into close contact with the irradiation target such as a lesion. Here, the above-described expanded state and the second expanded state are the same state. In the expanded state (second expanded state), placement (alignment) of the light irradiation portion 200 at a predetermined position in the longitudinal axis direction A may be performed again. By bringing the balloon 30 into the expanded state (second expanded state), the light-transmitting window portion 31 of the balloon 30 is brought into close contact with the irradiation target. In this state, the irradiation target can be irradiated with light that is emitted from the light irradiation portion 200 and passes through the light-transmitting window portion 31 toward the outside in the radial direction C. By bringing the light-transmitting window portion 31 close to or into close contact with the irradiation target such as a lesion, light can be more reliably applied to the irradiation target such as a lesion. Furthermore, the state of the irradiation target such as a lesion can be visually recognized more clearly through the visual recognition window portion 33 and the light-transmitting window portion 31, and displacement of the balloon 30 during treatment can be prevented. The step of irradiating the irradiation target with light that is emitted from the light irradiation portion 200 and passes through the light-transmitting window portion 31 toward the outside in the radial direction C may be repeatedly performed. In this case, after the balloon 30 is brought into the contracted state or the first expanded state and is aligned again with the irradiation target such as a lesion, the balloon 30 is brought into the expanded state or the second expanded state, and the irradiation target is irradiated.

[0053] In addition, placement of the light irradiation body 201 in the insertion passage 10a may be performed after the balloon 30 is expanded from the contracted state and brought into the first expanded state, or the second expanded state. By placing the light irradiation body 201 in the insertion passage 10a in a state in which the balloon 30 is expanded, bending or breaking of the light irradiation body 201 can be prevented when the balloon catheter 1 is inserted into a living body through a treatment instrument channel 101a of the endoscope device 101.

[0054] After completion of the treatment, the balloon 30 is brought into the contracted state, and the balloon catheter 1 is removed from the living body together with the light irradiation body 201 through the treatment instrument channel of the endoscope device 101.

[0055] Next, details of the marker portion 50 of the present embodiment will be described with reference to Figs. 2 to 4B.

[0056] As described above, the marker portion 50 indicates the position of the light-transmitting window portion 31 in the circumferential direction B. By including such a marker portion 50, an operator can confirm the position of the light-transmitting window portion 31 in the circumferential direction B by visually recognizing the marker portion 50 using the endoscope device 101, even in a state in which the balloon 30 is contracted or in a state in which the balloon 30 of the balloon catheter 1 is inserted into a living body.

[0057] The position of the marker portion 50 of the present embodiment in the circumferential direction B substantially coincides with the position of the light-transmitting window portion 31 in the circumferential direction B. With such an arrangement, the position of the light-transmitting window portion 31 in the circumferential direction B can be easily confirmed by visually recognizing the marker portion 50.

[0058] The marker portion 50 of the present embodiment is disposed at the distal end portion 11 of the tubular member 10 in the longitudinal axis direction A. With such an arrangement, the marker portion 50 can be easily visually recognized by the endoscope device 101.

[0059] As illustrated in Figs. 2, 3, and 4B, the marker portion 50 of the present embodiment is a cutout portion 15 formed by cutting out a part of the tubular member 10 in the circumferential direction B. Here, “cutting out the tubular member 10” indicates cutting off or cutting through a part of the tubular member 10. With such an arrangement, the marker portion 50 indicating the position of the light-transmitting window portion 31 in the circumferential direction B can be easily realized. In addition, because no member needs to be added to the balloon catheter 1, the configuration of the balloon catheter 1 can be simplified.

[0060] The cutout portion 15 of the present embodiment is formed by cutting out a part of the tubular member 10 in the longitudinal axis direction A. In addition, the cutout portion 15 of the present embodiment extends, in the longitudinal axis direction A, from a distal end of the tubular member 10 to a predetermined position distal to a proximal end of the tubular member 10. That is, a distal end 15b of the cutout portion 15 of the present embodiment coincides with the distal end of the tubular member 10. However, the distal end 15b of the cutout portion 15 does not need to coincide with the distal end of the tubular member 10. Furthermore, although the cutout portion 15 of the present embodiment is formed only in a portion of the distal end portion 11 of the tubular member 10 that is covered by the proximal tubular portion 35 of the balloon 30, the cutout portion 15 may be formed in a portion of the distal end portion 11 of the tubular member 10 that is not covered by the proximal tubular portion 35 of the balloon 30. However, by forming the cutout portion 15 only in the portion of the distal end portion 11 of the tubular member 10 that is covered by the proximal tubular portion 35 of the balloon 30 as in the present embodiment, leakage and the like of fluid supplied to the fluid containing space 30a of the balloon 30 from the cutout portion 15 can be suppressed.

[0061] In the cutout portion 15 of the present embodiment, a cutout angle θ2 in the circumferential direction B gradually decreases from the distal end 15b toward a proximal end 15a. That is, in the cutout portion 15 of the present embodiment, the cutout angle θ2 is maximum at the distal end 15b and is minimum at the proximal end 15a. The cutout angle θ2 at the distal end 15b of the cutout portion 15 of the present embodiment is 180 degrees. The cutout angle θ2 at the proximal end 15a of the cutout portion 15 of the present embodiment is 0 degrees. The cutout angle θ2 means an angle defined by two straight lines L3 and L4 connecting both ends 16a and 16b of the cutout portion 15 in the circumferential direction B to the longitudinal axis O in a cross section parallel to the radial direction C of the tubular member 10 (see Fig. 4B).

[0062] As described above, the light-transmitting window portion 31 extends over the predetermined angular range that does not cover an entire region in the circumferential direction B. Here, a maximum value of the cutout angle θ2 of the cutout portion 15 of the present embodiment in the circumferential direction B substantially coincides with the predetermined angular range of the light-transmitting window portion 31. In addition, when viewed from the longitudinal axis direction A, a bisector of the cutout angle θ2 of the cutout portion 15 of the present embodiment in the circumferential direction B substantially coincides, with a bisector of the above-described angle θ1 (see Fig. 4A) of the light-transmitting window portion 31 of the present embodiment in a cross section parallel to the radial direction C of the tubular member 10. With such an arrangement, the position of the light-transmitting window portion 31 in the circumferential direction B can be easily confirmed by visually recognizing the marker portion 50. In the present embodiment, while the predetermined angular range of the light-transmitting window portion 31 in the circumferential direction B is 180 degrees as described above, the maximum value of the cutout angle θ2 of the cutout portion 15 in the circumferential direction B is 180 degrees as described above, and the values coincide with each other. In addition, in the present embodiment, in a cross section parallel to the radial direction C of the tubular member 10, a bisector of the predetermined angular range (180 degrees) of the light-transmitting window portion 31 in the circumferential direction B and a bisector of the cutout angle θ2 (180 degrees) of the cutout portion 15 in the circumferential direction B substantially coincide with each other when viewed from the longitudinal axis direction A. However, as long as the position of the light-transmitting window portion 31 in the circumferential direction B can be confirmed by visually recognizing the marker portion 50, the maximum value of the cutout angle θ2 of the cutout portion 15 in the circumferential direction B does not need to substantially coincide with the predetermined angular range of the light-transmitting window portion 31. More specifically, in a cross section parallel to the radial direction C of the tubular member 10, when a bisector of the cutout angle θ2 of the cutout portion 15 in the circumferential direction B substantially coincides with a bisector of the angle θ1 (see Fig. 4A) of the light-transmitting window portion 31 when viewed from the longitudinal axis direction A, the maximum value of the cutout angle θ2 of the cutout portion 15 in the circumferential direction B does not need to substantially coincide with the predetermined angular range of the light-transmitting window portion 31.

[0063] The shape of the cutout portion 15 is not limited to the shape illustrated in Figs. 2, 3, and 4B. Figs. 5A to 5C are diagrams illustrating modifications of the cutout portion 15. As illustrated in Fig. 5A, in a cutout portion 15, the cutout angle θ2 in the circumferential direction B may be constant from a distal end 15b to a proximal end 15a. In addition, as illustrated in Fig. 5B, a cutout portion 15 may have a portion formed by cutting out an entire region of a tubular member 10 in the circumferential direction B. Furthermore, as illustrated in Fig. 5C, a cutout portion 15 may be a hole formed in an outer surface of a tubular member 10.

[0064] Figs. 6A to 6C are diagrams illustrating modifications of the balloon catheter 1. Figs. 6A to 6C illustrate states in which a balloon catheter 1 is viewed from the radial direction C. As illustrated in Figs. 6A to 6C, an outline of a cutout portion 15 in a front view as viewed from the radial direction C may be substantially the same as, and may have a similar relationship with, an outline of a light-transmitting window portion 31 in a front view as viewed from the radial direction C. With such an arrangement, before inserting the balloon catheter 1 into a living body, the operator can confirm the shape of the light-transmitting window portion 31 without expanding a balloon 30 by visually recognizing the cutout portion 15 formed in a tubular member 10. In addition, even in a state in which the balloon 30 of the balloon catheter 1 is inserted into the living body, the operator can confirm the shape of the light-transmitting window portion 31 by visually recognizing the cutout portion 15 formed in the tubular member 10 using an endoscope device 101. In the example illustrated in Fig. 6A, both the outline of a cutout portion 15 in a front view as viewed from the radial direction C and the outline of a light-transmitting window portion 31 in a front view as viewed from the radial direction C are substantially rectangular. In addition, in the example illustrated in Fig. 6B, both the outline of a cutout portion 15 in a front view as viewed from the radial direction C and the outline of a light-transmitting window portion 31 in a front view as viewed from the radial direction C are substantially elliptical. Furthermore, in the example illustrated in Fig. 6C, both the outline of a cutout portion 15 in a front view as viewed from the radial direction C and the outline of a light-transmitting window portion 31 in a front view as viewed from the radial direction C are substantially circular. However, the outline of the cutout portion 15 in a front view as viewed from the radial direction C and the outline of the light-transmitting window portion 31 in a front view as viewed from the radial direction C are not limited to those illustrated in Figs. 6A to 6C.

[0065] Fig. 7 is a diagram illustrating another modification of the cutout portion 15. As illustrated in Fig. 7, a cutout portion 15 may differ from a portion of a tubular member 10 other than the cutout portion 15 in at least one of hue, saturation, and brightness. With such an arrangement, visibility of the cutout portion 15 can be further enhanced. In the example illustrated in Fig. 7, the cutout portion 15 differs from the portion of the tubular member 10 other than the cutout portion 15 in hue and brightness. As in a modification illustrated in Fig. 9 described later, when a separate member is attached to a tubular member 10 and a cutout portion 15 is formed in the separate member, the cutout portion 15 may differ from a portion of the separate member other than the cutout portion 15 in at least one of hue, saturation, and brightness.

[0066] Fig. 8A is a perspective view illustrating a modification of the tubular member 10. Fig. 8B is a plan view of the tubular member illustrated in Fig. 8A as viewed from the radial direction C. A tubular member 10 illustrated in Figs. 8A and 8B includes a marker portion 50 different from the marker portion 50 illustrated in Figs. 2 and 3. In other words, the tubular member 10 illustrated in Figs. 8A and 8B includes two marker portions 50. For convenience of description, one marker portion 50 having a configuration similar to that of the marker portion 50 illustrated in Figs. 2 and 3 is referred to as a “first marker portion 50a”, and the other marker portion 50 is referred to as a “second marker portion 50b”.

[0067] As illustrated in Figs. 8A and 8B, the second marker portion 50b is disposed at a position different from the first marker portion 50a in the circumferential direction B and is configured to be distinguishable from the first marker portion 50a. By including such a second marker portion 50b, even when the field of view of an endoscope device 101 is limited to a part of a tubular member 10 in the circumferential direction B and the first marker portion 50a is outside the field of view of an endoscope device 101, the position of a light-transmitting window portion 31 in the circumferential direction B can be confirmed by visually recognizing the second marker portion 50b using the endoscope device 101. In the example illustrated in Figs. 8A and 8B, the second marker portion 50b is disposed at a position offset by 180 degrees in the circumferential direction B with respect to the first marker portion 50a. In addition, in the example illustrated in Figs. 8A and 8B, both the first marker portion 50a and the second marker portion 50b are cutout portions 15 formed by cutting out a part of the tubular member 10 in the circumferential direction B. In the example illustrated in Figs. 8A and 8B, the cutout portion 15 serving as the first marker portion 50a has a U-shaped outline in a front view as viewed from the radial direction C, whereas the cutout portion 15 serving as the second marker portion 50b has a circular outline in a front view as viewed from the radial direction C. By making the first marker portion 50a and the second marker portion 50b have different outlines in this manner, the first marker portion 50a and the second marker portion 50b can be easily distinguished in the example illustrated in Figs. 8A and 8B. The first marker portion 50a and the second marker portion 50b do not need to have different outlines as long as the first marker portion 50a and the second marker portion 50b are distinguishable. For example, the first marker portion 50a and the second marker portion 50b may be configured to differ from each other in at least one of hue, saturation, and brightness.

[0068] Fig. 9 is a diagram illustrating still another modification of the cutout portion 15. As illustrated in Fig. 9, a cutout portion 15 may be formed by cutting out a part, in the circumferential direction B, of a separate member attached to a tubular member 10. The separate member means a member not formed integrally with the tubular member 10. With such an arrangement, the degree of freedom in the configuration of the cutout portion 15 can be increased. In the example illustrated in Fig. 9, a tubular member 90 serving as the separate member is fitted on the outside, in the radial direction C, of a distal end portion 11 of the tubular member 10. A hole serving as the cutout portion 15 is formed in an outer surface of the tubular member 90.

[0069] The balloon catheter according to the present disclosure is not limited to the specific configurations illustrated in the above-described embodiment and modifications, and various modifications, changes, and combinations are possible without departing from the scope of the claims. Specifically, although the marker portion 50 of the above-described embodiment is the cutout portion 15 formed in the tubular member 10, the marker portion 50 may be, for example, a coating film such as ink applied to the outer surface of the tubular member 10. In addition, although the marker portion 50 of the above-described embodiment is provided on the tubular member 10, the marker portion 50 may be provided on, for example, the proximal tubular portion 35 of the balloon 30. Industrial Applicability

[0070] The present disclosure relates to a balloon catheter. Reference Signs List

[0071] 1 Balloon catheter1a Insertion portion1b Proximal operation portion2a Light-transmitting portion2b Light-transmission limiting portion10 Tubular member10a Insertion passage11 Distal end portion of tubular member12a Main tube portion12b Small-diameter portion15 Cutout portion15a Proximal end of cutout portion15b Distal end of cutout portion16a One end in circumferential direction of cutout portion in cross section parallel to radial direction16b Other end in circumferential direction of cutout portion in cross section parallel to radial direction30 Balloon30a Fluid containing space31 Light-transmitting window portion32 Light blocking portion33 Visual recognition window portion33a One end in circumferential direction of light-transmitting window portion in cross section parallel to radial direction33b Other end in circumferential direction of light-transmitting window portion in cross section parallel to radial direction34 Expandable main body portion35 Proximal tubular portion36 Distal tubular portion36a Closing wall41 Central portion42 Proximal reduced-diameter portion43 Distal reduced-diameter portion45 Base body46 Coating layer50 Marker portion50a First marker portion50b Second marker portion100 Endoscope system101 Endoscope device102 Control device102a Light source section102b Processor section103 Display unit104 Light source device105 Fluid supply tool200 Light irradiation portion201 Light irradiation body202 Light transmission memberA Longitudinal axis directionB Circumferential directionC Radial directionO Longitudinal axis of tubular member

Claims

A balloon catheter comprising: a tubular member having a longitudinal axis; a balloon that is continuous with a distal side of the tubular member in a longitudinal axis direction and expandable and contractible in a radial direction about the longitudinal axis, the balloon including, in an expanded state, a light-transmitting window portion extending over a predetermined angular range that does not cover an entire region in a circumferential direction around the longitudinal axis; and a marker portion indicating a position of the light-transmitting window portion in the circumferential direction. 2. The balloon catheter according to claim 1, wherein the marker portion is a cutout portion formed by cutting out a part, in the circumferential direction, of the tubular member or of a separate member attached to the tubular member. 3. The balloon catheter according to claim 2, wherein a maximum value of a cutout angle of the cutout portion in the circumferential direction substantially coincides with the predetermined angular range of the light-transmitting window portion. 4. The balloon catheter according to claim 2, wherein an outline of the cutout portion in a front view as viewed from the radial direction is substantially the same as an outline of the light-transmitting window portion in a front view as viewed from the radial direction. 5. The balloon catheter according to claim 2, wherein the cutout portion differs from a portion of the tubular member other than the cutout portion or a portion of the separate member other than the cutout portion in at least one of hue, saturation, and brightness. 6. The balloon catheter according to claim 1, wherein the marker portion is disposed at a distal end portion of the tubular member in the longitudinal axis direction. 7. The balloon catheter according to claim 1, wherein when the marker portion is a first marker portion, the balloon catheter further comprises a second marker portion that is disposed at a position different from the first marker portion in the circumferential direction and is distinguishable from the first marker portion. 8. The balloon catheter according to claim 1, wherein the light-transmitting window portion of the balloon extends substantially parallel or parallel to the longitudinal axis direction. 9. The balloon catheter according to claim 1, wherein the balloon includes a visual recognition window portion disposed on a proximal side in the longitudinal axis direction of the light-transmitting window portion and spaced apart from the light-transmitting window portion. 10. The balloon catheter according to claim 9, wherein the visual recognition window portion extends with a greater inclination than the light-transmitting window portion with respect to the longitudinal axis direction. 11. The balloon catheter according to claim 1, wherein the balloon comprises a proximal tubular portion that is continuous with a proximal side of the balloon and is fixed to the tubular member, the proximal tubular portion being light-transmitting, the marker portion is provided at a portion of a distal end portion of the tubular member in the longitudinal axis direction, the portion being covered by the proximal tubular portion from an outside in the radial direction, and the marker portion is configured to be visually recognizable, through the proximal tubular portion, by an endoscope device in a state in which the balloon catheter is inserted in a treatment instrument channel of the endoscope device and the balloon protrudes distally from the treatment instrument channel. 12. The balloon catheter according to claim 11, wherein the marker portion is a cutout portion formed by cutting out a part, in the circumferential direction, of the distal end portion of the tubular member or of a separate member attached to the distal end portion.

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