JP7148308B2 - balloon catheter - Google Patents

Description

The present invention relates to balloon catheters.

A balloon catheter exists as a medical device for dilating a lesion such as a stenosis formed in a biological lumen such as a blood vessel.

A balloon catheter, as shown in Patent Document 1 below, has a shaft having a lumen through which a guide wire can be inserted, and a balloon fixed to the distal end of the shaft and expandable by fluid flow. .

Japanese Patent Publication No. 2014-524329

However, the balloon is fixed with its ends overlapping the shaft. Therefore, the portion where the balloon is fixed at the distal end of the shaft has an increased wall thickness and higher rigidity than other positions at the distal end of the shaft. As a result, flexibility of the distal end portion of the shaft is reduced due to the portion where the balloon and the shaft are fixed, and followability to the guide wire is reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a balloon catheter in which the flexibility of the distal end of the shaft is ensured and the followability of the distal end of the shaft to the guide wire is improved. do.

A balloon catheter according to the present invention includes a balloon having a shaft having a lumen, a distal waist portion, a proximal waist portion, and a body portion positioned between the distal waist portion and the proximal waist portion. wherein the distal waist portion and the proximal waist portion are fixed to the shaft, and the shaft has, at a position where the distal waist portion is fixed to the shaft, an inner peripheral surface of the shaft, The shaft has a recess that does not penetrate through the thickness of the shaft and extends in the circumferential direction of the lumen of the shaft, and the shaft includes an outer tube shaft having a bore and an inner tube disposed in the bore of the outer tube shaft. a tube shaft, wherein the inner tube shaft comprises a first member and a second member disposed on the distal end side of the first member and having more flexibility than the first member; The first member is fixed to the second member at the tip waist portion, and the recess does not exist at the boundary between the first member and the second member.

The balloon catheter according to the present invention can ensure the flexibility of the distal end of the shaft by the concave portion even at a position where the distal waist portion is fixed to the shaft at the distal end of the shaft and the rigidity is increased. Therefore, the balloon catheter according to the present invention can improve the ability of the distal end of the shaft to follow the guide wire.

FIG. 1 shows a balloon catheter according to an embodiment of the invention; It is a figure which shows the cross section of the axial direction of 2 A of broken line parts shown in FIG. It is a figure which shows the cross section of the axial direction of the broken line part 2B shown in FIG. It is a figure which expands and shows the broken line part 3 of FIG. 2A. It is a figure which expands and shows the broken line part 4 of FIG.

Hereinafter, embodiments of the present invention will be described with reference to each drawing. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios.

As shown in FIG. 1, the balloon catheter 10 according to the present embodiment expands a balloon 180 disposed on the distal end side of a shaft 100 at a lesion such as a stenosis formed in a biological lumen, thereby increasing the size of the lesion. It is a medical device that expands and treats

The balloon catheter 10 can be configured, for example, as a PTCA treatment balloon catheter used to dilate a coronary artery stenosis. However, the balloon catheter 10 can be used to treat lesions such as constrictions formed in biological organs such as other blood vessels, bile ducts, trachea, esophagus, other digestive tracts, urethra, ear and nose cavities, and other organs. It can also be configured as a targeted balloon catheter.

The balloon catheter 10 will be described below.

As shown in FIG. 1, the balloon catheter 10 has an elongated shaft 100, a balloon 180 arranged on the distal side of the shaft 100, and a hub 190 arranged on the proximal side of the shaft 100. ing. Each part of the balloon catheter 10 will be described in detail below.

In the description of the embodiment, the direction in which the shaft 100 extends is defined as the axial direction X (see FIGS. 2A to 4), the side where the balloon 180 is arranged in the axial direction X is defined as the distal end side of the balloon catheter 10, and the axial direction X is defined as the distal end side of the balloon catheter 10. The side on which the hub 190 is arranged is the proximal side of the balloon catheter 10 . Further, in the description of the embodiments, the distal end means a certain range including the distal end (most proximal end) and its periphery, and the proximal end means a certain range including the proximal end (most proximal end) and its periphery. means range.

(shaft)
As shown in FIGS. 2A and 2B, the shaft 100 has an outer shaft 110 having a lumen 111 and an inner shaft 120 arranged in the lumen 111 of the outer shaft 110 .

As shown in FIG. 2A, the outer tube shaft 110 has a lumen (expansion lumen) 111 through which a fluid for expanding the balloon 180 can flow. The inner tubular shaft 120 has a lumen (guidewire lumen) 121 through which the guidewire G is inserted.

As shown in FIGS. 1 and 2B, shaft 100 has a proximal opening 101 (guidewire port) that communicates with lumen 121 of inner tubular shaft 120 . As shown in FIG. 2B , proximal opening 101 is formed near proximal end 122 of inner tubular shaft 120 . As shown in FIG. 1, the base end opening 101 is formed near the tip side of the shaft 100 in this embodiment. That is, the balloon catheter 10 is configured as a so-called rapid exchange catheter. However, the balloon catheter 10 may be configured as an over-the-wire balloon catheter with a guidewire port formed at the proximal end of the shaft.

As shown in FIG. 2B , the outer tube shaft 110 has a distal outer tube 130 and a proximal outer tube 140 connected to the proximal side of the distal outer tube 130 .

The distal outer tube 130 and the proximal outer tube 140 are integrally connected (fused) to the inner tube shaft 120 near the proximal opening 101 of the shaft 100 .

The lumen 131 of the distal outer tube 130 and the lumen 141 of the proximal outer tube 140 are in the state where the distal outer tube 130 and the proximal outer tube 140 are connected, and the expansion space 181 of the balloon 180 (see FIG. 2A). A communicating lumen 111 is formed.

The outer tube shaft 110 is made of, for example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer, thermoplastic resins such as soft polyvinyl chloride, polyurethane elastomers, polyamide elastomers, polyester elastomers, and the like. It can be formed from various elastomers, polyamides, crystalline plastics such as crystalline polyethylene and crystalline polypropylene, and the like.

As shown in FIGS. 2A and 2B, a portion of inner tubular shaft 120 is disposed in lumen 111 of outer tubular shaft 110 . Further, as shown in FIG. 2B, the distal end portion of the inner tube shaft 120 is arranged so as to protrude toward the distal end side of the outer tube shaft 110 .

As shown in FIG. 2A , the inner tube shaft 120 includes a base inner tube 150 (corresponding to the first member) and a distal end portion of the base inner tube 150 that is disposed on the distal side of the base inner tube 150 and is more flexible than the base inner tube 150 . and a member 160 (corresponding to a second member). By providing the tip member 160, the inner tube shaft 120 can prevent damage to living organs when the tip of the balloon catheter 10 comes into contact with the inner wall of a living body lumen (blood vessel wall, etc.).

The lumen 151 of the base inner tube 150 and the lumen 161 of the tip member 160 form a lumen 121 through which the guidewire G can be inserted when the base inner tube 150 and the tip member 160 are connected.

The base inner tube 150 has an inner layer 152 and an outer layer 153 made of a different material than the inner layer 152 in this embodiment.

The inner layer 152 includes, but is not limited to, polyolefin (eg, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polystyrene, It can be made of polymeric materials such as polyvinyl chloride, polyamide, polyester, polyurethane, polyimide, fluorine-based resin, or mixtures thereof. From the viewpoint of insertability of the guidewire G, the inner layer 152 is preferably made of a material having slidability with respect to the guidewire.

The outer layer 153 is not particularly limited, but from the viewpoint of the flexibility of the inner tube shaft 120 and the fusion bondability with the balloon 180, for example, polyolefin (eg, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene- vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polystyrene, polyvinyl chloride, polyamide, polyester, polyurethane, polyimide, fluorine-based resin, or a mixture thereof.

As shown in FIG. 2A, the inner tube shaft 120 has imaging markers 170a, 170b.

The contrast marker 170 a is arranged at a position indicating the boundary between the distal tapered portion 185 and the central portion 186 of the inner tube shaft 120 . The contrast marker 170 b is arranged at a position indicating the boundary between the proximal side tapered portion 187 and the central portion 186 of the inner tube shaft 120 .

Each of the contrast markers 170a, 170b can be made of, for example, metals such as platinum, gold, silver, iridium, titanium, tungsten, or alloys thereof.

(balloon)
As shown in FIG. 2A, balloon 180 has a distal waist portion 182 , a proximal waist portion 183 , and a body portion 184 positioned between distal waist portion 182 and proximal waist portion 183 .

The tip waist portion 182 is fixed to the inner tubular shaft 120 . The proximal waist portion 183 is fixed to the outer tube shaft 110 . The method of fixing the balloon 180 to the inner tube shaft 120 and the outer tube shaft 110 is not particularly limited, but fusion bonding can be employed, for example.

The distal waist portion 182 has a sloped portion 188 that slopes from the proximal side to the distal side of the shaft 100 . The inclined portion 188 is formed so that the thickness of the shaft 100 decreases from the base end side toward the tip end side.

The body portion 184 forms an expansion space 181 between itself and the inner tubular shaft 120 that communicates with the inner lumen 111 of the outer tubular shaft 110 . When the fluid flows into the expansion space 181, the body part 184 expands in the radial direction and exerts expansion force on a lesion such as a stenosis. The body portion 184 is wound around the inner pipe shaft 120 in the contracted state.

Body portion 184 has a distal taper portion 185 , a proximal taper portion 187 , and a central portion 186 positioned between distal taper portion 185 and proximal taper portion 187 in an expanded state. ing. The tip side tapered portion 185 continues to the tip waist portion 182 and is formed so that the dimension in the radial direction increases from the tip side to the base end side. The central portion 186 continues to the distal side tapered portion 185 and is formed such that the radial dimension thereof is substantially constant from the distal end side to the proximal end side. The proximal-side tapered portion 187 continues to the central portion 186 and is formed such that its dimension in the radial direction decreases from the distal end side to the proximal end side.

The balloon 180 is not particularly limited, but may be made of, for example, polyethylene, polypropylene, ethylene-propylene copolymer polyolefin, polyester such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymer, crosslinked ethylene-vinyl acetate copolymer. It can be formed from coalescing, thermoplastic resin such as polyurethane, polyamide, polyamide elastomer, polystyrene elastomer, silicone rubber, latex rubber, and the like.

(hub)
As shown in FIG. 1, the hub 190 has a port 191 that can be fluid-tightly and air-tightly connected to a supply device (not shown) such as an indeflator for supplying a fluid (for example, a contrast medium or physiological saline). is doing. The port 191 can be configured by, for example, a known luer taper or the like configured to be connectable/separable with a tube or the like. Port 191 communicates with lumen 111 of outer tube shaft 110 .

(Concave portion of inner pipe shaft)
As shown in FIG. 3 , the inner tube shaft 120 does not penetrate through the thickness of the inner tube shaft 120 to the inner peripheral surface of the inner tube shaft 120 at the position where the tip waist portion 182 is fixed to the inner tube shaft 120 . , has a circumferentially extending recess 200 in the lumen 121 of the inner tube shaft 120 . In the description of the embodiment, the circumferential direction means the direction around the axial direction X of the shaft 100 .

Since the inner tubular shaft 120 has the concave portion 200 in this manner, the flexibility of the distal end portion of the inner tubular shaft 120 can be ensured even at a position where the distal waist portion 182 of the balloon 180 is fixed and the rigidity is increased. can. Therefore, the balloon catheter 10 can improve the followability of the distal end portion of the inner tube shaft 120 to the guide wire G. As a result, when the operator advances the balloon catheter 10 along the guide wire G inserted through the inner tube shaft 120 , the inner surface of the inner tube shaft 120 is positioned at the distal end of the inner tube shaft 120 . and the outer surface of the guide wire G, and follows the guide wire G while suppressing the formation of a gap. Also, the recess 200 does not penetrate through the thickness of the inner pipe shaft 120 . Therefore, the balloon catheter 10 suppresses the breakage of the inner tube shaft 120 and increases the flexibility of the inner tube shaft 120, compared to the case where the inner tube shaft 120 is formed with a through hole or the like penetrating through the thickness thereof. can be secured.

As shown in FIG. 3 , the recess 200 includes a first recess 210 , a second recess 220 located closer to the proximal end of the shaft 100 than the first recess 210 , and a second recess 220 in the cross section of the shaft 100 in the axial direction X. It has a third recess 230 located closer to the proximal end of the shaft 100 than the recess 220 and a fourth recess 240 located closer to the proximal end of the shaft 100 than the third recess 230 . Here, the second recessed portion 220 corresponds to the tip side recessed portion in relation to the third recessed portion 230 or the fourth recessed portion 240 . In addition, the third recess 230 corresponds to the proximal recess in relation to the second recess 220 , and corresponds to the distal recess in relation to the fourth recess 240 . In addition, the fourth recess 230 corresponds to the proximal side recess in relation to the second recess 220 or the third recess 230 .

In this way, recess 200 has a plurality of recesses 210, 220, 230, and 240 at the position where distal waist portion 182 is fixed to inner tubular shaft 120, so that the distal end portion of inner tubular shaft 120 is more flexible. It can be improved further.

The first recess 210 is formed on the inner surface of the tip member 160 of the inner tube shaft 120 . The second to fourth recesses 220 , 230 , 240 are formed on the inner surface of the base inner tube 150 of the inner tube shaft 120 . Therefore, the balloon catheter 10 can ensure flexibility of both the tip member 160 and the base inner tube 150 at the position where the distal waist portion 182 is fixed to the inner tube shaft 120 .

The base inner tube 150 is fixed to the tip member 160 at the position of the tip waist portion 182 (at the position where the tip waist portion 182 is arranged in the axial direction X), and the recess 200 is formed by the base inner tube 150. and the tip member 160 does not exist at the boundary S.

Here, the “boundary portion S” means a portion of the inner tube shaft 120 where the base inner tube 150 and the tip member 160 are fixed by fusion, adhesion, pressure bonding, or the like. For example, when the base inner tube 150 and the tip member 160 are fixed by fusion, the boundary portion S means a portion where the base inner tube 150 and the tip member 160 are fused. For example, when the base inner tube 150 and the tip member 160 are fixed by adhesion, the boundary portion S is the portion from the tip surface of the base inner tube 150 to the base end surface of the tip member 160 (the base inner tube 150 and the tip member 160 (including hardened portions of adhesive between For example, when the base inner tube 150 and the tip member 160 are fixed by crimping, the boundary portion S means a portion where the tip surface of the base inner tube and the base end surface of the tip member 160 overlap. 3 and 4 are schematic diagrams showing cross sections of the distal end portion of the balloon catheter 10 in the axial direction X, and the width of the boundary portion S (the length of the shaft 100 along the axial direction X) is 3 and FIG. 4 are not limiting.

As described above, since the recess 200 does not exist in the boundary portion S, the balloon catheter 10 improves the flexibility of the distal end portion of the inner tube shaft 120 by arranging the tip member 160, while the base inner tube 150 and the tip member 160 are arranged. The strength of the boundary portion S (fixed portion) can be ensured. Thereby, it is possible to suppress the tip member 160 from falling off from the base inner tube 150 .

Each recess 210 , 220 , 230 , 240 is formed by a ring-shaped groove that encircles the inner peripheral surface of the inner pipe shaft 120 . Therefore, the inner tube shaft 120 can bend at each of the recesses 210 , 220 , 230 , 240 following the bending of the guide wire G. However, each recess 210 , 220 , 230 , 240 does not have to completely circle the inner peripheral surface of the inner pipe shaft 120 .

As shown in FIG. 4, peripheral edge portions 250 of the recesses 210, 220, 230, 240 on the inner surface side of the inner tube shaft 120 are formed with curved surfaces. That is, the peripheral edges 250 on the inner surface side of the recesses 210, 220, 230, 240 are rounded. Therefore, when the operator manipulates the guide wire G inserted through the lumen of the inner tube shaft 120 , the balloon catheter 10 can prevent the guide wire G from being caught in the recesses 210 , 220 , 230 , 240 . However, the peripheral portion 250 may be angular as long as the operator can operate the guide wire G inserted through the lumen of the inner tubular shaft 120 .

As shown in FIG. 4, the widths (dimensions along the axial direction X) of the recesses 210, 220, 230, and 240 vary from the inner surface side of the inner tube shaft 120 toward the outer surface side of the inner tube shaft 120 ( in the direction indicated by the middle arrow Y). Therefore, the inner pipe shaft 120 can be easily bent starting from narrow portions (apex 260 on the outer surface side) of the recesses 210 , 220 , 230 , 240 on the outer surface side. Thereby, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 can easily follow the curved portion of the guide wire G.

The maximum depth h3 (maximum dimension in the radial direction) of the third recess 230 is greater than the maximum depth h2 of the second recess 220 (h3>h2). The maximum depth h4 of the fourth recess 240 is greater than the maximum depth h3 of the third recess 230 (h4>h3). That is, the second to fourth concave portions 220, 230, 240 are formed so that the maximum depth increases from the distal end to the proximal end. When the inner pipe shaft 120 bends, the recess 200 tends to widen in the width direction as the maximum depth of the recess 200 increases. That is, the inner tube shaft 120 can be bent more in the axial direction of the inner tube shaft 120 as the maximum depth of the concave portion 200 is larger. Therefore, when the second to fourth concave portions 220, 230, 240 are formed so that the maximum depth increases from the distal end to the proximal end, the inner tube shaft 120 has an inner diameter from the distal end to the proximal end. The tube shaft 120 tends to bend gradually in the axial direction. Therefore, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 is smoothly curved along the curved portion of the guide wire G, and the curved portion of the guide wire G is curved. department can follow.

Note that FIG. 4 shows an example in which the maximum depth h1 of the first recess 210 and the maximum depth h2 of the second recess 220 are substantially the same. However, the maximum depth h1 of the first recess 210 may be larger or smaller than the maximum depth h2 of the second recess 220 while considering the flexibility of the tip member 160 and the base inner tube 150. .

The maximum width w3 of the third recess 230 is larger than the maximum width w2 of the second recess 220 (w3>w2). The maximum width w4 of the fourth recess 240 is larger than the maximum width w3 of the third recess 230 (w4>w3). That is, the second to fourth concave portions 220, 230, 240 are formed so that the maximum width increases from the distal end to the proximal end. The concave portion 200 forms a flexible region along the axial direction of the inner tube shaft 120 as the maximum width of the concave portion 200 increases. That is, the inner tube shaft 120 can be bent more in the axial direction of the inner tube shaft 120 as the maximum width of the concave portion 200 is larger. Therefore, when the second to fourth concave portions 220, 230, 240 are formed so that the maximum width increases from the distal end to the proximal end, the inner tube shaft 120 has an inner tube width from the distal end to the proximal end. It becomes easier for the shaft 120 to gradually bend in the axial direction. Therefore, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 is smoothly curved along the curved portion of the guide wire G, and the curved portion of the guide wire G is curved. department can follow.

Note that FIG. 4 shows an example in which the maximum width w1 of the first recess 210 and the maximum width w2 of the second recess 220 are substantially the same. However, the maximum width w1 of the first recess 210 may be larger or smaller than the maximum width w2 of the second recess 220, taking into consideration the flexibility of the distal end member and the base inner tube.

As shown in FIG. 3, the base inner tube 150 of the inner tube shaft 120 is located at the position where the inclined portion 188 is arranged in the cross section of the shaft 100 in the axial direction X (the inclined portion 188 is arranged in the axial direction X). position), it has second to fourth recesses 220,230,240. The maximum depth and maximum width of the second to fourth recesses 220 , 230 , 240 increase from the distal end side of the shaft 100 toward the proximal end side of the shaft 100 at the position of the inclined portion 188 .

Therefore, the thickness of the inclined portion 188 of the balloon 180 increases from the distal side to the proximal side, and the rigidity of the inclined portion 188 increases from the distal side to the proximal side. By increasing the maximum depth and maximum width of the recesses 220, 230, 240 from the distal side to the proximal side, the rigidity of the base inner tube 150 can be decreased from the distal side to the proximal side. Therefore, the balloon catheter 10 can ensure flexibility while smoothing the change in rigidity in the vicinity of the inclined portion 188 of the balloon catheter 10 .

In this embodiment, the example in which both the maximum depth and the maximum width of the second to fourth concave portions 220, 230, 240 increase from the distal side toward the proximal side has been described. However, if at least one of the maximum depth or maximum width of the second to fourth recesses 220, 230, 240 is increased from the distal end side to the proximal end side, the balloon catheter 10 will have a change in stiffness near the inclined portion 188. can be done smoothly.

As shown in FIG. 4 , the second to fourth recesses 220 , 230 , 240 are formed between the inner layers 152 spaced apart in the axial direction X in the base inner tube 150 . The resin forming the outer layer 153 of the base inner tube 150 enters between the adjacent inner layers 152 in the second to fourth recesses 220 , 230 , 240 .

More specifically, the inner layer 152 of the base inner tube 150 will be described in more detail. As shown in FIGS. It has an inner layer 152b, a third inner layer 152c and a fourth inner layer 152d. Tip portions of the first inner layer 152a, the second inner layer 152b, the third inner layer 152c, and the fourth inner layer 152d are provided at positions in the axial direction X where the inclined portion 188 is arranged. The first inner layer 152a and the second inner layer 152b are spaced apart, and a second recess 220 is formed between the first inner layer 152a and the second inner layer 152b. The second inner layer 152b and the third inner layer 152c are spaced apart, and a third recess 230 is formed between the second inner layer 152b and the third inner layer 152c. The third inner layer 152c and the fourth inner layer 152d are separated, and a fourth recess 240 is formed between the third inner layer 152c and the fourth inner layer 152d. The fourth inner layer 152d extends to the proximal opening 101 of the shaft 100 (see FIG. 2B).

Thus, the resin forming the outer layer 153 of the base inner tube 150 enters between the adjacent inner layers 152 in the second to fourth recesses 220, 230, 240, so that the base inner tube 150 has two or more layers. , and the resin of the inner layer 152 and the resin of the outer layer 153 are firmly bonded to each other, and the strength of the base inner tube 150 can be ensured.

4, the second to fourth recesses 220, 230, 240 are formed at approximately equal intervals in the axial direction X of the shaft 100. As shown in FIG. 4, the distance from the first recess 210 to the boundary S between the base inner tube 150 and the tip member 160 and the distance from the second recess 220 to the boundary S between the base inner tube 150 and the tip member 160 , are substantially the same. However, the arrangement of the first to fourth recesses 210, 220, 230, 240 is not limited to the illustrated example. Also, relative dimensions (width, height, etc.) of each of the recesses 210, 220, 230, 240 to other members are not limited to the illustrated example.

(Production method)
Next, an example of a method for manufacturing the balloon catheter 10 will be described.

First, an operator prepares the shaft 100 including the outer tube shaft 110 and the inner tube shaft 120 , the balloon 180 and the hub 190 . Further, the inner tube shaft 120 prepared here is obtained by fusing the base inner tube 150 and the tip member 160 and forming the concave portion 200 .

Next, the operator fuses the balloon 180 to the shaft 100 (outer tube shaft 110 and inner tube shaft 120). Specifically, the operator fuses the proximal waist portion 183 of the outer tube shaft 110 and the balloon 180 , and fuses the proximal inner tube 150 , the tip member 160 and the distal waist portion 182 of the balloon 180 . Also, the operator attaches the hub 190 to the base end portion of the outer tubular shaft 110 of the shaft 100 . Thereby, the balloon catheter 10 shown in FIG. 1 is manufactured.

The manufacturing method described above is merely an example. For example, when the balloon is fused to the shaft, the operator fuses the proximal waist portion 183 of the outer tube shaft 110 and the balloon 180, and then the proximal inner tube 150, the tip member 160, and the distal waist portion of the balloon 180. 182 may be fused together.

(action)
The balloon catheter 10 according to this embodiment includes a shaft 100 having a lumen 121, a distal waist portion 182, a proximal waist portion 183, and a body portion positioned between the distal waist portion 182 and the proximal waist portion 183. 184 and a balloon 180 having a. A distal waist portion 182 and a proximal waist portion 183 are fixed to the shaft 100 . Shaft 100 has a concave portion 200 extending in the circumferential direction of lumen 121 of shaft 100 without penetrating through the thickness of shaft 100 on the inner peripheral surface of shaft 100 at the position where tip waist portion 182 is fixed to shaft 100 . have.

According to the balloon catheter 10 described above, the flexibility of the distal end portion of the shaft 100 is ensured by the concave portion 200 even at a position where the distal waist portion 182 is fixed to the shaft 100 at the distal end portion of the shaft 100 and the rigidity is increased. can be done. Therefore, the balloon catheter 10 can improve the ability of the distal end of the shaft 100 to follow the guide wire G. As shown in FIG.

Also, the width of the concave portion 200 decreases from the inner surface side of the shaft 100 toward the outer surface side of the shaft 100 . Therefore, the shaft 100 can be easily bent starting from the narrow portion on the outer surface side of the concave portion 200 . Therefore, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 curves smoothly along the curved portion of the guide wire G. Thereby, the balloon catheter 10 can improve followability to the guide wire G. FIG.

Further, the recess 200 includes a second recess 220 and a third recess 230 located closer to the proximal end of the shaft 100 than the second recess 220 in the cross section of the shaft 100 in the axial direction X. As shown in FIG. The maximum depth h3 of the third recess 230 is greater than the maximum depth h2 of the second recess 220. As shown in FIG. Further, the recess 200 includes a third recess 230 and a fourth recess 240 located closer to the proximal end of the shaft 100 than the third recess 230 in the axial cross section of the shaft 100 . The maximum depth h4 of the fourth recess 240 is greater than the maximum depth h3 of the third recess 230. As shown in FIG. When the inner tube shaft 120 bends, the recess 200 tends to widen in the width direction as the maximum depth of the recess 200 increases. That is, the inner tube shaft 120 can be bent more in the axial direction of the inner tube shaft 120 as the maximum depth of the concave portion 200 is larger. Therefore, the inner tube shaft 120 tends to bend gradually with respect to the axial direction of the inner tube shaft 120 from the distal end toward the proximal end. Therefore, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 is smoothly curved along the curved portion of the guide wire G, and the curved portion of the guide wire G is curved. department can follow.

Further, the recess 200 includes a second recess 220 and a third recess 230 located closer to the proximal end of the shaft 100 than the second recess 220 in the axial cross section of the shaft 100 . The maximum width w3 of the third recess 230 is greater than the maximum width w2 of the second recess 220. As shown in FIG. Further, the recess 200 includes a third recess 230 and a fourth recess 240 positioned closer to the proximal end of the shaft 100 than the third recess 230 in the axial cross section of the shaft 100 . The maximum width w4 of the fourth recess 240 is greater than the maximum width w2 of the third recess 230. As shown in FIG. The concave portion 200 forms a flexible region along the axial direction of the inner tube shaft 120 as the maximum width of the concave portion 200 increases. That is, the inner tube shaft 120 can be bent more in the axial direction of the inner tube shaft 120 as the maximum width of the concave portion 200 is larger. Therefore, the inner tube shaft 120 tends to bend gradually with respect to the axial direction of the inner tube shaft 120 from the distal end toward the proximal end. Therefore, when the operator advances the balloon catheter 10 along the curved guide wire G, the distal end portion of the inner tube shaft 120 is smoothly curved along the curved portion of the guide wire G, and the curved portion of the guide wire G is curved. department can follow.

A peripheral edge portion 250 of the concave portion 200 on the inner surface side of the shaft 100 is formed with a curved surface. Therefore, the balloon catheter 10 can prevent the guide wire G from being caught in the concave portion 200 when the operator manipulates the guide wire G inserted through the lumen of the inner tubular shaft 120 .

Further, the distal waist portion 182 has an inclined portion 188 that inclines from the proximal end side of the shaft 100 toward the distal end side of the shaft 100 . The shaft 100 has a plurality of recesses 220 , 230 , 240 at positions where the inclined portions 188 are arranged in a cross section of the shaft 100 in the axial direction X. As shown in FIG. The maximum depth and/or maximum width of recesses 210 , 220 , 230 increase from the distal end of shaft 100 toward the proximal end of shaft 100 at the location of ramp 188 . Therefore, by adjusting the maximum depth and/or maximum width of the plurality of recesses 220, 230, and 240 to adjust the rigidity change due to the thickness change of the inclined portion 188 of the balloon 180,
The balloon catheter 10 smoothes the change in rigidity of the distal end portion of the balloon catheter 10 and ensures the flexibility of the distal end portion of the balloon catheter 10 .

Further, the shaft 100 has an outer tubular shaft 110 having a lumen 111 and an inner tubular shaft 120 arranged in the lumen 111 of the outer tubular shaft 110 . The inner tube shaft 120 includes a base inner tube 150 and a tip member 160 that is arranged on the distal side of the base inner tube 150 and is more flexible than the base inner tube 150 . The base inner tube 150 is fixed to the tip member 160 at the tip waist portion 182 , and the recess 200 does not exist at the boundary S between the base inner tube 150 and the tip member 160 . Therefore, in the balloon catheter 10, the flexibility of the distal end portion of the inner tube shaft 120 is improved by arranging the tip member 160, and the strength of the boundary portion S (fixed portion) between the base inner tube 150 and the tip member 160 can be ensured. . Thereby, it is possible to suppress the tip member 160 from falling off from the base inner tube 150 .

In addition, recess 200 includes a plurality of ring-shaped grooves that circle the inner peripheral surface of shaft 100 . Therefore, the inner tube shaft 120 can follow the bending of the guide wire G and can be easily bent with the concave portion 200 as a starting point.

The inner tube shaft 120 also has an inner layer 152 and an outer layer 153 made of a material different from that of the inner layer 152 . The resin forming the outer layer 153 enters between the adjacent inner layers 152 in the recess 200 . Therefore, even when two or more layers of the inner tube shaft 120 form the concave portion 200, the resin of the inner layer 152 and the resin of the outer layer 153 are strongly bonded, and the strength of the inner tube shaft 120 can be secured.

Although the balloon catheter according to the present invention has been described above through the embodiments, the present invention is not limited to the configurations described in the embodiments, and can be appropriately modified based on the description of the claims. be.

For example, in the above embodiment, the base inner tube 150 of the inner tube shaft 120 has the outer layer 153 and the inner layer 152 (has a two-layer structure). However, the base inner tube of the inner tube shaft may have a single-layer structure, or may have a multi-layer structure of three or more layers.

Further, for example, in the above embodiment, the tip member 160 of the inner tube shaft 120 has a single-layer structure. However, the tip member of the inner tube shaft may have a multilayer structure of two or more layers (that is, it may have an inner layer and an outer layer).

Further, for example, in the above-described embodiment, an example in which the inner tube shaft 120 has the base inner tube 150 and the tip member 160 has been described. However, the inner tubular shaft may be composed of a single tubular member from the proximal end to the distal end, or may be composed of three or more tubular members.

Further, for example, in the above-described embodiment, an example in which the recess 200 is configured by a ring-shaped groove that circles in the circumferential direction has been described. However, the circumferential direction means the direction around the axial direction X as described above. Therefore, for example, the recess may be configured by a spiral groove formed in the inner peripheral surface of the shaft.

Further, for example, in the above embodiment, an example in which the inner tube shaft 120 has the first to fourth recesses 210, 220, 230, 240 has been described. However, the number of recesses is not particularly limited as long as it is one or more.

Further, for example, in the above-described embodiment, the width of the concave portion 200 is reduced from the inner surface side of the inner tube shaft 120 toward the outer surface side of the inner tube shaft 120 . However, the width of the recess may be constant from the inner surface side of inner tube shaft 120 toward the outer surface side of inner tube shaft 120 . Further, for example, in the above-described embodiment, an example in which the apex 260 on the outer surface side of the concave portion 200 has an acute angle has been described. However, the apex of the recess 200 on the outer surface side may be formed with a curved surface (that is, may be rounded).

Further, for example, in the above-described embodiment, an example in which each component of the balloon catheter 10 is fixed by fusion has been described. However, each component of the balloon catheter may be fixed by a method such as bonding with an adhesive.

Further, for example, in the above-described embodiment, an example in which the tip waist portion 182 has the inclined portion 188 has been described. However, the tip waist portion does not have to have an inclined portion. That is, the distal waist portion may have a uniform thickness from the distal end to the proximal end.

10 balloon catheter,
100 shaft,
110 outer tube shaft,
120 inner tube shaft,
121 Lumen,
150 base inner tube (first member),
152 inner layer,
153 outer layer,
160 tip member (second member),
180 balloon,
182 tip waist,
183 proximal waist,
184 main body,
188 ramp,
190 Hub,
200 recess,
210 first recess,
220 second recess (tip side recess in relation to third and fourth recesses),
230 third recess (proximal side recess in relation to second recess, distal side recess in relation to fourth recess),
240 fourth recess (proximal recess in relation to second and third recesses),
250 rim,
G guide wire,
S boundary,
X-axis direction,
h maximum depth (of recesses),
w Maximum width (of recess).

Claims (8)

a shaft having a lumen;
a balloon having a distal waist portion, a proximal waist portion, and a body portion positioned between the distal waist portion and the proximal waist portion;
The distal waist portion and the proximal waist portion are fixed to the shaft,
The shaft has, at the position where the tip waist portion is fixed to the shaft, a concave portion that does not penetrate through the thickness of the shaft and extends in the circumferential direction of the bore of the shaft on the inner peripheral surface of the shaft. ,
The shaft has an outer tubular shaft having a lumen and an inner tubular shaft arranged in the lumen of the outer tubular shaft,
The inner tube shaft comprises a first member and a second member disposed on the distal end side of the first member and having more flexibility than the first member,
The balloon catheter , wherein the first member is fixed to the second member at the position of the distal waist portion, and the concave portion does not exist at a boundary portion between the first member and the second member . 2. The balloon catheter according to claim 1, wherein the width of the concave portion decreases from the inner surface side of the shaft toward the outer surface side of the shaft. The recess includes a distal recess and a proximal recess positioned closer to the proximal end of the shaft than the distal recess in an axial cross section of the shaft,
3. The balloon catheter of claim 1 or 2, wherein the maximum depth of the proximal recess is greater than the maximum depth of the distal recess. The recess includes a distal recess and a proximal recess positioned closer to the proximal end of the shaft than the distal recess in an axial cross section of the shaft,
The balloon catheter according to any one of claims 1 to 3, wherein the maximum width of the proximal recess is greater than the maximum width of the distal recess. The balloon catheter according to any one of claims 1 to 4, wherein a peripheral edge portion of the recess on the inner surface side of the shaft is formed with a curved surface. the distal waist portion has an inclined portion that inclines from the proximal end side of the shaft toward the distal end side of the shaft;
the shaft has a plurality of recesses at positions where the inclined portions are arranged in an axial cross section of the shaft;
6. The maximum depth and/or maximum width of the recess according to any one of claims 1 to 5, wherein the maximum depth and/or maximum width of the recess increases from the distal end side of the shaft toward the proximal end side of the shaft at the position of the inclined portion. balloon catheter. The balloon catheter according to any one of Claims 1 to 6 , wherein the recess includes a plurality of ring-shaped grooves that circle the inner peripheral surface of the shaft. The inner tube shaft has an inner layer and an outer layer made of a material different from that of the inner layer,
7. The balloon catheter according to claim 6 , wherein the resin forming the outer layer enters between the adjacent inner layers in the recess.

Images