JP6982061B2 - How to manufacture balloon catheters and medical long bodies - Google Patents

Description

The present invention relates to a method for manufacturing a balloon catheter and a medical elongated body.

A balloon catheter is widely known as a medical device for expanding a lesion such as a stenosis formed in a living lumen such as a blood vessel. Balloon catheters are generally classified into an over-the-wire type and a rapid exchange type.

As described in Patent Document 1 below, the rapid exchange type balloon catheter has a guide wire lumen formed in which a guide wire is inserted only on the distal end side of the catheter shaft in which the balloon is arranged. For this reason, a guide wire port (base end opening) that allows the guide wire to be taken in and out of the guide wire lumen is provided at a predetermined position on the distal end side in the axial direction (longitudinal direction) of the catheter shaft.

In the catheter shaft used for a rapid exchange type balloon catheter, the outer tip shaft, the outer proximal shaft, and the inner shaft constituting the catheter shaft are heat-sealed and integrated with each other in the vicinity of the guide wire port. The outer tip shaft and the outer base shaft are tubular members forming an expansion lumen through which a pressure medium (working fluid) for balloon expansion is circulated. The inner shaft is a tubular member with a lumen forming a guidewire lumen.

JP-A-2015-93173

A surgeon such as a doctor inserts a guide wire into a lesion such as a stenosis formed in a blood vessel in a procedure using a balloon catheter. The operator inserts the proximal end side of the guide wire into the guide wire lumen from the distal end side of the inner shaft, and leads the guide wire from the guide wire lumen through the guide wire port on the proximal end side of the inner shaft. Then, the operator guides the balloon of the balloon catheter to the lesion portion by moving the balloon catheter along the guide wire.

During the procedure, the surgeon may move the guide wire toward the proximal end side or the distal end side with the guide wire inserted through the guide wire lumen of the balloon catheter, or remove the guide wire from the proximal end opening of the inner shaft. do. When the operator performs these operations, excessive stress concentration near the guide wire port of the inner shaft may cause the inner shaft of the balloon catheter to break. When the guide wire is sandwiched between the broken portion (torn portion) of the inner shaft, it becomes difficult for the operator to smoothly move the guide wire, so that the operability of the guide wire is significantly 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 capable of preventing the inner shaft from breaking near the proximal opening of the balloon catheter, and a method for manufacturing a long medical body. And.

The balloon catheter according to the present invention includes an outer distal shaft and an outer proximal shaft that is fixed to the proximal side of the outer distal shaft and has a lumen that communicates with the lumen of the outer distal shaft. A shaft, an inner shaft whose distal end side is arranged in the lumen of the outer distal end shaft and whose proximal end side is arranged on the outer surface of the outer proximal end shaft, and a balloon fixed to the inner shaft and the outer distal end shaft. The inner shaft has a proximal opening that opens on the outer surface of the outer proximal shaft, and the inner shaft is part of a peripheral edge that forms the proximal opening. have a convex portion, said proximal opening than said proximal end of the outer distal shaft disposed proximally, the inner shaft between the proximal end of said outer distal shaft the convex portion, It has a flexible portion that is thinner than the convex portion and is flexible.

Further, the method for manufacturing a medical elongated body according to the present invention is to: the outer tip shaft, the outer base end shaft, the inner shaft, the first mandrel arranged in the lumen of the inner shaft, and the outer tip shaft. A second mandrel located in the lumen and in the lumen of the outer proximal shaft is supplied, the first mandrel axially overlapping the first region and the proximal side of the first region. It has a second region extending toward the proximal end side from the proximal end of the first region, and a recess is formed between the first region and the second region, and the outer tip shaft has a recess. By arranging the inner shaft in the lumen and inserting the first region of the first mandrel into the lumen of the inner shaft, the proximal end of the inner shaft is axially aligned with the recess of the first mandrel. The first mandrel is arranged so as to overlap with each other, and the inner shaft is aligned with the outer surface of the outer proximal shaft, and the inner cavity of the outer distal shaft and the inner lumen of the outer proximal shaft are connected to each other. The proximal shaft is placed, the second mandrel is inserted into the lumen of the outer distal shaft and the lumen of the outer proximal shaft, the outer distal shaft, the outer proximal shaft, the inner shaft, and the first. A heat-shrinkable tube is arranged so as to cover the second region of one mandrel, heat is applied to the heat-shrinkable tube to shrink it, and the outer tip shaft, the outer base end shaft, and the inner shaft are fused. The present invention includes forming a convex portion at the base end of the inner shaft arranged in the concave portion of the first mandrel.

In the balloon catheter configured as described above, a convex portion is formed in a part of the peripheral portion forming the proximal end opening of the inner shaft. The convex portion of the inner shaft can prevent the inner shaft from breaking even when excessive stress concentration occurs in the vicinity of the proximal end opening when the guide wire is taken out from the proximal end opening of the inner shaft. Therefore, the balloon catheter can prevent the inner shaft from breaking, and can prevent the operability of the guide wire from deteriorating due to the breaking of the inner shaft.

In the above method for manufacturing a medical elongated body, when the inner shaft and the outer shaft are fused, the first region provided by the first mandrel is inserted into the lumen of the inner shaft, and the first region of the first mandrel is inserted. The base end of the inner shaft is placed in the recess formed between the first mandrel and the second region of the first mandrel, and covers the outer tip shaft, the outer base end shaft, the inner shaft, and the second region of the first mandrel. Place the heat shrink tubing so that. In the above manufacturing method, heat is applied to the heat-shrinkable tube to shrink the tube, thereby fusing the outer tip shaft, the outer base end shaft, and the inner shaft, and the inner shaft arranged in the recess of the first mandrel. A convex portion is formed at the base end. Thereby, the above manufacturing method can provide a medical long body provided with an inner shaft having a convex portion formed to prevent the inner shaft from breaking near the proximal end opening.

It is a figure which shows the balloon catheter which concerns on embodiment. 2A is an enlarged cross-sectional view of a portion surrounded by the broken line portion 2A in FIG. 1, and FIG. 2B is an enlarged cross-sectional view of the portion surrounded by the broken line portion 2B in FIG. FIG. 2B is an enlarged view showing a portion surrounded by the broken line portion 3A in FIG. 2B. FIG. 4 is a diagram for explaining a method for manufacturing a medical long body according to an embodiment, and FIG. 4A is a cross section showing a state in which an inner shaft is vertically overlapped on an outer tip shaft. 4 (B) is a cross-sectional view showing a state in which the first mandrel is inserted into the inner shaft, and FIG. 4 (C) is a cross-sectional view showing a state in which the outer base end shaft is inserted into the lumen of the outer tip shaft. Is. FIG. 5 is a diagram for explaining a method for manufacturing a medical long body according to an embodiment, and FIG. 5 (A) shows a second mandrel in the lumen of the outer tip shaft and the lumen of the outer proximal shaft. Is a cross-sectional view showing a state in which the heat-shrinkable tube is inserted, and FIG. 5 (B) is a cross-sectional view showing a state in which a heat-shrinkable tube is arranged. FIG. 6 is a diagram for explaining a method for manufacturing a medical long body according to an embodiment, and FIG. 6A is an enlarged cross section showing a state when a convex portion is formed on the inner shaft. FIG. 6B is an enlarged cross-sectional view showing the state after the convex portion is formed on the inner shaft. It is sectional drawing for demonstrating the positional relationship of the large diameter part formed in the heat shrink tube and the outer tip shaft. It is an enlarged sectional view which shows the convex part of the inner shaft which concerns on the modification. It is an enlarged sectional view which shows the convex part of the inner shaft which concerns on the modification example. It is an enlarged sectional view which shows the convex part of the inner shaft which concerns on other modification examples.

As shown in FIG. 1, the balloon catheter 10 according to the present embodiment expands a balloon 160 arranged on the distal end side of a shaft 100 in a lesion such as a stenosis formed in a living lumen, thereby expanding the lesion. It is a medical device that spreads and treats.

The balloon catheter 10 is configured as a PTCA therapeutic balloon catheter used to widen a narrowed portion of a coronary artery. However, the balloon catheter 10 treats a lesion site such as a stenosis formed in a biological organ such as another blood vessel, bile duct, trachea, esophagus, other gastrointestinal tract, urethra, ear and nose lumen, and other organs. It can also be configured as a intended balloon catheter.

Hereinafter, the balloon catheter 10 will be described.

As shown in FIG. 1, the balloon catheter 10 includes a long shaft (corresponding to a “medical long body”) 100, a balloon 160 arranged on the distal end side of the shaft 100, and a proximal end of the shaft 100. It has a hub 190, which is arranged on the side.

In the description of the embodiment, the side on which the balloon 160 is arranged is the distal end side of the balloon catheter 10, the side on which the hub 190 is arranged is the proximal end side of the balloon catheter 10, and the direction in which the shaft 100 is extended is the axial direction. Further, in the description of the embodiment, the tip portion means a certain range including the tip (tip) and its periphery, and the proximal end portion means a certain range including the proximal end (most proximal end) and its periphery. Means a range.

As shown in FIG. 1, the balloon catheter 10 is configured as a so-called rapid exchange type catheter in which a proximal opening (guide wire port) 105 through which the guide wire 200 can enter and exit is formed near the tip end side of the shaft 100. ing.

As shown in FIGS. 2A and 2B, the shaft 100 is arranged in the outer shaft 110 having a lumen (expanded lumen) 115 and the inner cavity 115 of the outer shaft 110, and the guide wire 200. It has an inner shaft 140, which comprises a lumen (guide wire lumen) 145 through which it is inserted.

As shown in FIGS. 1 and 2B, the shaft 100 has a proximal opening (corresponding to the "base opening" of the inner shaft) 105 communicating with the lumen 145 of the inner shaft 140. There is. The base end opening 105 is formed near the base end of the inner shaft 140.

As shown in FIG. 2B, the outer shaft 110 has an outer tip shaft 120 and an outer proximal shaft 130 fixed to the proximal side of the outer tip shaft 120.

The outer tip shaft 120 is formed of a tubular member having a lumen 125 extending in the axial direction. Similarly, the outer proximal shaft 130 is formed of a tubular member in which an axially extending lumen 135 is formed.

The outer tip shaft 120 and the outer proximal shaft 130 are integrally connected (fused) with the inner shaft 140 in the vicinity of the proximal opening 105 of the shaft 100.

The lumen 125 of the outer tip shaft 120 and the lumen 135 of the outer proximal shaft 130 communicate with each other. Further, the lumen 125 of the outer tip shaft 120 and the lumen 135 of the outer proximal shaft 130 form a lumen (expanded lumen) 115 that communicates with the expansion space 167 of the balloon 160 in a state of communicating with each other.

The outer tip shaft 120 and the outer base shaft 130 are, for example, polyethylene, polypropylene, ethylene-propylene copolymer, polyolefin such as ethylene-vinyl acetate copolymer, thermoplastic resin such as soft polyvinyl chloride, polyurethane elastomer, polyamide. It can be formed of various polymers such as an elastomer and a polyester elastomer, and a crystalline plastic such as polyamide, crystalline polyethylene and crystalline polypropylene.

As shown in FIG. 2A, the tip end side of the inner shaft 140 is arranged in the lumen 125 of the outer tip shaft 120. A certain range on the tip end side of the inner shaft 140 is arranged so as to project toward the tip end side of the outer tip shaft 120. Further, as shown in FIG. 2B, in the inner shaft 140, the proximal end side of the inner shaft 140 is arranged on the outer surface of the outer proximal shaft 130.

As shown in FIG. 2A, the inner shaft 140 has a tip member 180 arranged on the tip side. The tip member 180 has a lumen 181 through which the guide wire 200 can be inserted.

By providing the tip member 180 on the tip side of the inner shaft 140, it is possible to prevent damage to a living organ when the tip of the balloon catheter 10 comes into contact with a living lumen (inner wall of a blood vessel or the like). The tip member 180 can be formed of, for example, a flexible resin material. However, the material of the tip member 180 is not particularly limited as long as it can be fixed to the inner shaft 140.

As shown in FIG. 2A, the lumen 145 of the inner shaft 140 communicates with the lumen 181 of the tip member 180 on the tip end side of the inner shaft 140. Further, as shown in FIG. 2B, the lumen 145 of the inner shaft 140 communicates with the proximal opening 105 on the proximal side of the inner shaft 140. A convex portion 150, which will be described later, is formed in the vicinity of the base end opening 105 of the inner shaft 140.

The inner shaft 140 can be formed of, for example, the same material as that exemplified as the constituent material of the outer shaft 110.

As shown in FIG. 2A, the balloon 160 is fixed to the tip portion 161 fixed to the tip 141 of the inner shaft 140 and the tip 111 (corresponding to the “tip of the outer tip shaft”) of the outer shaft 110. It has a base end portion 163 and an intermediate portion 166 forming a maximum outer diameter portion formed between the tip end portion 161 of the balloon 160 and the base end portion 163 of the balloon 160. Further, the balloon 160 is located between the tip side tapered portion 164 formed between the tip portion 161 of the balloon 160 and the intermediate portion 166 of the balloon 160, and the base end portion 163 of the balloon 160 and the intermediate portion 166 of the balloon 160. It has a base end side tapered portion 165 formed in the above.

The balloon 160 forms an expansion space 167 that communicates with the lumen 115 of the outer shaft 110 between the balloon 160 and the outer peripheral surface of the shaft 100. When the fluid flows into the expansion space 167, the balloon 160 expands in the radial direction intersecting the axial direction of the balloon 160.

The balloon 160 includes, for example, polyethylene, polypropylene, a polyolefin of an ethylene-propylene copolymer, polyester such as polyethylene terephthalate, polyvinyl chloride, an ethylene-vinyl acetate copolymer, a crosslinked ethylene-vinyl acetate copolymer, polyurethane and the like. It can be formed of a thermoplastic resin, a polyamide, a polyamide elastomer, a polystyrene elastomer, a silicone rubber, a latex rubber, or the like.

As shown in FIG. 2A, the inner shaft 140 has a contrast marker 170 indicating a substantially central position in the axial direction of the intermediate portion 166 of the balloon 160. The contrast marker 170 can be formed of, for example, a metal such as platinum, gold, silver, iridium, titanium, or tungsten, or an alloy thereof. The contrast marker 170 is located at a position indicating the boundary between the distal end side tapered portion 164 and the intermediate portion 166 on the inner shaft 140, and between the proximal end side tapered portion 165 and the intermediate portion 166 on the inner shaft 140. It may be arranged at a position indicating a boundary portion.

As shown in FIG. 1, the hub 190 has a port 191 that can be liquid-tightly and airtightly connected to a supply device (not shown) such as an indeflator for supplying a fluid (for example, a contrast medium or a physiological saline solution). is doing. The port 191 of the hub 190 can be configured by, for example, a known luer taper or the like in which a tube or the like is configured to be connectable and separable.

Next, the inner shaft 140 will be described in detail.

As shown in FIG. 2B, a proximal opening (guide wire port) 105 that opens on the outer surface of the outer proximal shaft 130 is formed on the proximal side of the inner shaft 140.

Further, as shown in FIG. 3, the inner shaft 140 has a convex portion 150 on a part of the peripheral edge portion 105a forming the proximal end opening 105 (a part along the circumferential direction of the peripheral edge portion 105a). As shown in FIG. 3, the convex portion 150 is moved from the proximal end side to the distal end side of the inner shaft 140 in order to prevent breakage of the peripheral edge portion 105a forming the proximal end opening 105 and to secure flexibility. It is preferably formed by increasing the wall thickness toward the wall. FIG. 3 is an enlarged cross-sectional view of the portion 3A surrounded by the broken line shown in FIG. 2 (B) (enlarged cross-sectional view in the axial direction of the inner shaft 140).

The above-mentioned "having a convex portion whose wall thickness increases from the proximal end side to the distal end side of the inner shaft" means at least in the circumferential direction of the peripheral edge portion 105a forming the proximal end opening 105 of the inner shaft 140. In part, the wall thickness of the portion of the inner shaft 140 fused with the proximal end 123 of the outer tip shaft 120, or near the distal end side of the portion where the inner shaft 140 and the proximal end 123 of the outer tip shaft 120 are fused. It means that a portion having a wall thickness larger than the wall thickness of the unfused portion located near the proximal end side is formed. For example, as shown in FIG. 3, the convex portion 150 may have a cross-sectional shape in which the wall thickness continuously increases from the base end side to the tip end side of the inner shaft 140, or a modification described later. As shown in (see FIG. 10), the cross-sectional shape may be such that the wall thickness gradually increases (a shape in which the wall thickness increases to a certain size with an arbitrary portion in the axial direction as a boundary).

As shown in FIG. 3, in the cross section of the inner shaft 140, the convex portion 150 is connected to a first inclined portion 151 that inclines from the base end side of the inner shaft 140 toward the tip end side and the tip end of the first inclined portion 151. It has a second inclined portion 152 that is inclined from the tip of the first inclined portion 151 toward the tip side of the inner shaft 140.

In the cross section shown in FIG. 3, the first inclined portion 151 is inclined outward in the radial direction (direction away from the axis of the inner shaft 140) from the peripheral edge portion 105a of the inner shaft 140 toward the proximal end side of the inner shaft 140. ing. Further, the first inclined portion 151 extends substantially parallel to the opening surface of the base end opening portion 105. That is, the first inclined portion 151 and the base end opening portion 105 exist on the same plane.

In the cross section shown in FIG. 3, the second inclined portion 152 extends from the tip of the first inclined portion 151 toward the tip end side of the inner shaft 140 so as to exhibit a cross-sectional shape different from that of the first inclined portion 151. Specifically, the base end side of the second inclined portion 152 is curved so as to draw an arc toward the tip end side of the inner shaft 140. The tip end side of the second inclined portion 152 has a cross-sectional shape that draws an arc from the base end side of the first inclined portion 151 toward the outer surface side of the inner shaft 140 so as to be connected to the outer surface of the inner shaft 140. ..

Since the first inclined portion 151 and the second inclined portion 152 are integrally formed as a part of the inner shaft 140, they are not clearly separated in the drawing, but the boundary between them is shown in FIG. In the cross section, the first inclined portion 151 exists at the boundary portion of the convex portion 150 in which the inclined direction (direction away from the axial center of the inner shaft 140) changes in a different direction (direction toward the axial center side of the inner shaft 140). ..

As shown in FIG. 3, the axial length L1 of the first inclined portion 151 of the convex portion 150 is formed longer than the axial length L2 of the second inclined portion 152 of the convex portion 150. The axial length L1 of the first inclined portion 151 and the axial length L2 of the second inclined portion 152 are the axial lengths of the longest portion of the convex portion 150 on the cross section shown in FIG. Is.

The axial length L1 of the first inclined portion 151 of the convex portion 150 can be formed to be, for example, 0.2 mm to 1.0 mm, and the axial length L2 of the second inclined portion 152 of the convex portion 150 can be formed, for example. , 0.1 mm to 0.8 mm can be formed.

The base end opening 105 of the inner shaft 140 is arranged on the base end side of the base end 123 of the outer tip shaft 120. Further, the inner shaft 140 has a flexible portion 158 between the base end 123 of the outer tip shaft 120 and the convex portion 150, which is thinner than the convex portion 150 and is flexible.

The flexible portion 158 is formed so as to have a wall thickness thinner than that of the convex portion 150 of the inner shaft 140. That is, the flexible portion 158 is located in the vicinity of the tip of the portion where the inner shaft 140 and the proximal end 123 of the outer tip shaft 120 are fused in the inner shaft 140, and the proximal end opening 105 of the inner shaft 140 is formed. It is a portion having a wall thickness smaller than that of the convex portion 150 provided in at least a part of the peripheral edge portion 105a to be formed. Further, the outer surface of the flexible portion 158 has a shape recessed inward of the inner shaft 140 with respect to the convex portion 150 in the cross section shown in FIG. Specifically, the flexible portion 158 is located between the base end 123 of the outer tip shaft 120 and the convex portion 150, and is located from the position of the outer surface of the shaft 100 in the base end 123 and the convex portion 150 of the outer tip shaft 120. Also exists in a recessed position. As will be described later, the flexible portion 158 is a portion in which the resin constituting the inner shaft 140 forms the convex portion 150 when the convex portion 150 arranged on the proximal end side of the inner shaft 140 with respect to the flexible portion 158 is formed. It is formed by flowing into. Therefore, the wall thickness of the flexible portion 158 is smaller than that of the convex portion 150 and smaller than that of the inner shaft 140 other than the portion where the convex portion 150 is formed.

The convex portion 150 can be formed, for example, in the range of 0.1 mm to 1.0 mm from the peripheral edge portion 105a forming the proximal end opening 105 toward the tip end side in the axial direction of the inner shaft 140. The flexible portion 158 can be formed, for example, from the base end 123 of the outer tip shaft to the base end side of the inner shaft 140 in a range of 0.5 mm to 3.0 mm. Further, the portion t1 having the largest wall thickness in the convex portion 150 can be formed to, for example, 0.1 mm to 0.5 mm. Further, the portion t2 having the smallest wall thickness in the flexible portion 158 can be formed to, for example, 0.02 mm to 0.2 mm.

As shown in FIG. 3, the proximal opening 105 of the inner shaft 140 is inclined from the proximal side to the distal end side of the inner shaft 140 in the axial cross section of the inner shaft 140. In the present embodiment, the first inclined portion 151 of the convex portion 150 and the proximal end opening 105 are arranged substantially in parallel so as to overlap each other on the same plane, but the proximal end opening 105 is, for example, the convex portion 150. It may be arranged non-parallel to the first inclined portion 151, and the inclination angle and the like are not particularly limited.

As shown in FIG. 3, the peripheral edge portion 105a of the proximal end opening 105 of the inner shaft 140 is formed by a curved surface in the axial cross section of the inner shaft 140. As shown in the figure, the cross-sectional shape of the peripheral edge portion 105a can be formed so as to be curved with a predetermined curvature from the peripheral edge portion 105a toward the proximal end opening 105 side formed inside the peripheral edge portion 105a.

The cross-sectional shape of the peripheral edge portion 105a is not limited to a curved shape, and may be, for example, a triangular shape or a rectangular shape.

As shown in FIG. 2, the outer tip shaft 120 has a large diameter portion 126 formed with a predetermined outer diameter D1. Further, the outer diameter D2 formed by the outer shaft 110 and the inner shaft 140 at the portion corresponding to the convex portion 150 of the inner shaft 140 is smaller than the outer diameter D1 of the large diameter portion 126.

As will be described later, when the inner shaft 140 and the outer shaft 110 (outer tip shaft 120 and outer base end shaft 130) are fused (see FIG. 5B), both shafts 110 and 140 are heat-shrinkable tubes 400. Covers a predetermined range (range indicated by arrow A1 in FIG. 7). When heat is applied to both shafts 110 and 140 in this state, the area covered by the heat shrink tubing 400 contracts inward in the radial direction (direction toward the inside of the shaft 100) of both shafts 110 and 140. At this time, the outer diameter is maintained before and after fusion of both shafts 110 and 140 in a range not affected by heat. As shown in FIG. 2B, a portion where the outer diameter of the outer tip shaft 120 is maintained before and after fusion formation forms a large diameter portion 126.

The portion where the outer diameter becomes smaller after the fusion of both shafts 110 and 140, that is, the portion covered with the heat shrink tube 400 when the both shafts 110 and 140 are fused, has an outer diameter larger than that of the large diameter portion 126. Form a small diameter portion 127. Further, between the large diameter portion 126 and the small diameter portion 127, a boundary portion 128 is formed in which the outer diameter gradually increases from the small diameter portion 127 to the large diameter portion 126 due to the influence of the heat applied to the heat shrink tube 400. To.

In the region where the heat-shrinkable tube 400 is arranged (the region indicated by the arrow A1 in FIG. 7) when the shaft 100 is manufactured, the heat-shrinkable tube 400 has the outer tip shaft 120, the outer base end shaft 130, the inner shaft 140, and the first It is not particularly limited as long as it covers the second region 312 of one mandrel 310. The tip of the heat-shrinkable tube 400 is arranged at a position away from the tip of the base end opening 105 of the inner shaft 140, and the base end of the heat-shrinkable tube 400 is the base of the base end opening 105 of the inner shaft 140. It is placed at a position away from the end to the base end side.

As shown in FIG. 3, the convex portion 150 of the inner shaft 140 has a width along the axial direction of the inner shaft 140. The term "having a width along the axial direction" as used herein means a portion in the cross section shown in FIG. 3 in which the convex portion 150 extends at a constant length along the axial direction (indicated by the broken line arrow w in the figure). It means to have the area shown).

As shown in FIG. 3, the width of the convex portion 150 of the inner shaft 140 increases toward the outer shaft 110 (outer base end shaft 130) side. That is, the outer peripheral shape of the convex portion 150 is formed so that the contact area (fused area) with the outer shaft 110 gradually expands in the width direction toward the proximal end side along the axial direction of the inner shaft 140. ing.

In the present embodiment, in the cross section shown in FIG. 3, the convex portion 150 has a shape inclined so that the width greatly expands toward the outer shaft 110 side toward the proximal end side of the inner shaft 140. However, the shape of the convex portion 150 is not limited to such a shape. For example, the convex portion 150 has a shape inclined so that the width becomes smaller toward the outer shaft 110 side toward the proximal end side of the inner shaft 140, or a constant width toward the proximal end side of the inner shaft 140. It may be formed so as to be formed by.

Next, a method of manufacturing the shaft (medical long body) 100 will be described.

First, a worker who manufactures the shaft 100 supplies (prepares) the outer tip shaft 120, the outer base end shaft 130, and the inner shaft 140.

The operator prepares, for example, a tubular member having an outer diameter and an inner diameter substantially constant in the axial direction as the outer tip shaft 120. Further, the operator can use the outer proximal shaft 130 as a tubular member whose tip is inclined diagonally from the distal end side toward the proximal end side and the portion other than the distal end has a substantially constant outer diameter and inner diameter in the axial direction. Prepare. Further, the operator can use the inner shaft 140 as a tubular member whose base end is inclined diagonally from the base end side to the tip end side and a portion other than the base end has a substantially constant outer diameter and inner diameter in the axial direction. (See FIG. 4C for shape examples of the shafts 120, 130, and 140, respectively).

The operator can use the first mandrel 310 placed in the lumen (guide wire lumen) 145 of the inner shaft 140 and the second mandrel placed in the inner 125 of the outer tip shaft 120 and the inner 135 of the outer proximal shaft 130. The 320 is supplied (prepared) (see FIG. 5 (A)).

As shown in FIG. 4A, the first mandrel 310 has a first region 311 arranged in the lumen 145 of the inner shaft 140 and a first region 311 while overlapping axially with the proximal end side of the first region 311. It has a second region 312 extending toward the base end side of the base end of the region 311. A recess 313 is formed between the first region 311 of the first mandrel 310 and the second region 312 of the first mandrel 310.

The first region 311 of the first mandrel 310 extends substantially linearly in the axial direction. The tip of the second region 312 of the first mandrel 310 is inclined toward the tip side, and forms a predetermined space with the first region 311. The concave portion 313 of the first mandrel 310 has the shape of the portion 313a facing the proximal end of the inner shaft 140 so that the peripheral edge portion 105a of the proximal end opening 105 of the inner shaft 140 can be formed into a curved cross-sectional shape. It is curved in a concave shape toward the side.

As shown in FIG. 4A, the operator arranges the inner shaft 140 in the lumen 125 of the outer tip shaft 120.

Next, the operator places the first mandrel 310 in the lumen 145 of the inner shaft 140, as shown in FIG. 4 (B). Specifically, the operator inserts the first mandrel 310 into the lumen 145 of the inner shaft 140, and the first mandrel 310 so that the base end of the inner shaft 140 vertically overlaps the recess 313 of the first mandrel 310. To place. At this time, the operator arranges the first mandrel 310 so that a part of the inner shaft 140 is exposed between the base end 123 of the outer tip shaft 120 and the recess 313 of the first mandrel 310.

Next, as shown in FIG. 4C, the operator puts the inner shaft 140 along the outer surface of the outer proximal shaft 130, while the inner cavity 125 of the outer distal shaft 120 and the inner portion of the outer proximal shaft 130. The outer proximal shaft 130 is arranged so that the lumens 135 are continuous.

Next, as shown in FIG. 5A, the operator inserts the second mandrel 320 into the lumen 125 of the outer tip shaft 120 and the lumen 135 of the outer proximal shaft 130. As the second mandrel 320, a known one that extends substantially linearly in the axial direction can be used.

The worker arranges the inner shaft 140 in the lumen 125 of the outer tip shaft 120, the work of arranging the first mandrel 310 on the inner shaft 140, and the work of arranging the outer base shaft 130 on the outer tip shaft 120. , The work of inserting the second mandrel 320 into the lumen 125 of the outer tip shaft 120 and the lumen 135 of the outer proximal shaft 130 can be performed in no particular order.

Next, the operator, as shown in FIG. 5C, heat-shrink tubing 400 so as to cover the outer tip shaft 120, the outer proximal shaft 130, the inner shaft 140, and the second region 312 of the first mandrel 310. To place. As the heat-shrinkable tube 400, for example, a hollow tubular member made of polyolefin or the like can be used.

The operator applies heat to the heat-shrinkable tube 400 in a state where the heat-shrinkable tube 400 is arranged, and fuses the outer tip shaft 120, the outer base end shaft 130, and the inner shaft 140. The heat-shrinkable tube 400 shrinks when heated, and is deformed so that the inner diameter of the heat-shrinkable tube 400 after heating is smaller than the inner diameter of the heat-shrinkable tube 400 before heating.

At this time, as shown in FIG. 6A, in the inner shaft 140, the portion exposed from the recess 313 of the first mandrel 310 of the inner shaft 140 is melted, and the resin constituting the inner shaft 140 is the first mandrel 310. It flows into the recess 313 side (in FIG. 6A, the resin flowing into the recess 313 side is indicated by reference numeral f).

Then, as shown in FIG. 6B, the thickness of the resin constituting the inner shaft 140 flowing into the recess 313 side of the first mandrel 310 increased from the base end side to the tip end side of the inner shaft 140. The convex portion 150 is formed. At this time, the operator is exposed to the portion where the thickness of the inner shaft 140 is reduced (exposed from the recess 313) due to the resin flowing into the recess 313 between the base end 123 of the outer tip shaft 120 and the tip of the convex portion 150. A flexible portion 158 is formed in the portion).

As shown in FIG. 7, a small diameter portion 127 is formed in a portion of each of the shafts 120, 130, and 140 covered by the heat-shrinkable tube 400 (the range indicated by the arrow A1 in FIG. 7), and the heat-shrinkable tube 400 forms a small diameter portion 127. A boundary portion 128 is formed in the uncovered portion (tip side of the small diameter portion 127), and a large diameter portion 126 is formed in the tip end side of the boundary portion 128.

By carrying out each of the above steps, the operator can obtain the inner shaft 140 in which the convex portion 150 and the flexible portion 158 are formed, and the outer shaft 110 in which the outer tip shaft 120 and the outer base end shaft 130 are formed. A shaft 100 can be manufactured.

Next, the operation of the balloon catheter 10 and the operation of the method for manufacturing the shaft 100 according to the present embodiment will be described.

The balloon catheter 10 according to the present embodiment has an outer proximal shaft 120 and an outer proximal shaft having a lumen 135 fixed to the proximal side of the outer distal shaft 120 and communicating with the lumen 125 of the outer distal shaft 120. An outer shaft 110 comprising 130, an inner shaft 140 whose distal end side is located in the lumen 125 of the outer distal shaft 120 and whose proximal side is located on the outer surface of the outer proximal shaft 130, and an inner shaft 140. It comprises a balloon 160 fixed to the outer tip shaft 120. Further, the base end of the inner shaft 140 has a base end opening (guide wire port) 105 that opens on the outer surface of the outer base end shaft 130, and the inner shaft 140 has a peripheral portion that forms the base end opening 105. A part of 105a has a convex portion 150 whose wall thickness increases from the proximal end side to the distal end side.

In the balloon catheter 10 configured as described above, the convex portion 150 is formed in a part of the peripheral edge portion 105a forming the proximal end opening 105 of the inner shaft 140. The convex portion 150 of the inner shaft 140 breaks the inner shaft 140 even when excessive stress concentration occurs in the vicinity of the proximal opening 105 when the guide wire 200 is taken out from the proximal opening 105 of the inner shaft 140. Can be prevented. Therefore, the balloon catheter 10 can prevent the inner shaft 140 from breaking, and can prevent the operability of the guide wire 200 from deteriorating due to the breaking of the inner shaft 140.

Further, the base end opening 105 of the inner shaft 140 is arranged on the base end side of the base end 123 of the outer tip shaft 120, and the inner shaft 140 is located between the base end 123 of the outer tip shaft 120 and the convex portion 150. It has a flexible portion 158 that is thinner than the convex portion 150 and is flexible.

The balloon catheter 10 configured as described above has a flexible portion 158 formed on the distal end side of the inner shaft 140 with respect to the convex portion 150. Therefore, when stress acts on the convex portion 150 from the guide wire 200 when the guide wire 200 is operated, the inner shaft 140 is deformed (bent) so that the vicinity of the convex portion 150 is rolled up from the flexible portion 158 as a starting point. Therefore, it is possible to prevent stress concentration from occurring in the vicinity of the base end opening 105 of the inner shaft 140. Thereby, the balloon catheter 10 can more preferably prevent the proximal opening 105 of the inner shaft 140 from breaking. Further, since the balloon catheter 10 has a flexible portion 158 formed on the distal end side of the inner shaft 140 with respect to the convex portion 150, the flexible portion 158 is used as a guide wire when the balloon catheter 10 is moved along the guide wire 200. It easily curves following the 200, and the followability to the guide wire 200 is enhanced.

Further, the proximal end opening 105 of the inner shaft 140 is inclined from the proximal end side toward the distal end side in the axial cross section of the inner shaft 140. Therefore, the opening area of the proximal end opening 105 can be formed larger than that in the case where the proximal end opening 105 of the inner shaft 140 is opened so as to be orthogonal to the axial direction of the inner shaft 140. This allows the operator to easily remove the guide wire 200 through the proximal opening 105 of the balloon catheter 10.

Further, the outer tip shaft 120 has a large diameter portion 126 formed with a predetermined outer diameter, and the outer shaft 110 and the inner shaft 140 are formed at a portion corresponding to the convex portion 150 formed on the inner shaft 140. The diameter is smaller than the outer diameter of the large diameter portion 126.

When inserting the balloon catheter 10 into a biological lumen such as a blood vessel, the surgeon utilizes, for example, one catheter (a known guiding catheter or the like) together with the balloon catheter 10 to another medical device (for example, a balloon catheter). A separate balloon catheter, catheter device used for diagnostic imaging, etc.) may be inserted. At this time, if the outer diameter of the shaft 100 in the convex portion 150 formed on the balloon catheter 10 is excessively large, the balloon catheter 10 and other medical devices interfere with each other in the catheter, and the smooth movement of both is hindered. Sometimes. Since the outer diameter of the convex portion 150 formed on the inner shaft 140 is smaller than the outer diameter of the large diameter portion 126 of the outer tip shaft 120 as described above, the balloon catheter 10 is formed on the inner shaft 140. Despite the formation of the ridge 150, interference with other medical devices in the lumen of the catheter can be suitably prevented.

Further, the convex portion 150 of the inner shaft 140 has a width along the axial direction of the inner shaft 140, and the width of the convex portion 150 increases toward the outer shaft 110 side. As a result, the inner shaft 140 has a large contact area (fused area) in which the convex portion 150 and the outer surface of the outer shaft 110 come into contact with each other on the proximal end side of the inner shaft 140, so that the inner shaft 140 and the outer shaft 110 have a larger contact area. The fixing force can be increased.

Further, the convex portion 150 formed on the inner shaft 140 includes a first inclined portion 151 that inclines from the proximal end side toward the distal end side and the tip of the first inclined portion 151 in the axial cross section of the inner shaft 140. It has a second inclined portion 152 that is connected and is inclined from the tip of the first inclined portion 151 toward the tip side of the inner shaft 140. The axial length of the first inclined portion 151 is formed to be longer than the axial length of the second inclined portion 152.

Since the balloon catheter 10 configured as described above has a relatively long axial length of the first inclined portion 151 formed on the proximal end side of the convex portion 150, it is inside in the axial direction of the inner shaft 140. The region where the outer diameter of the shaft 140 changes (the region from the base end of the convex portion 150 to the maximum outer diameter portion of the convex portion 150) becomes long. That is, since the inner shaft 140 has a longer axial length in the region where the outer diameter of the convex portion 150 changes so as to increase, a sudden increase in the outer diameter of the convex portion 150 can be suppressed. Therefore, in the balloon catheter 10, the amount of increase in the outer diameter becomes gradual from the proximal end side to the distal end side of the convex portion 150, so that the inner shaft 140 is kinked or the like caused by the rapid increase in the outer diameter. Can be prevented.

Further, the peripheral edge portion 105a of the proximal end opening 105 of the inner shaft 140 is formed of a curved surface. Therefore, when the operator takes out the guide wire 200 from the proximal end opening 105 of the inner shaft 140, the operator can prevent the guide wire 200 from being caught on the peripheral edge portion 105a of the proximal end opening 105, and the guide wire 200 can be smoothly guided. It can be taken out.

The method for manufacturing the shaft 100 according to the present embodiment includes an outer tip shaft 120, an outer base end shaft 130, an inner shaft 140, a first mandrel 310 arranged in the lumen 145 of the inner shaft 140, and an outer tip shaft 120. The second mandrel 320, which is located in the lumen 125 of the outer proximal shaft 130 and the lumen 135 of the outer proximal shaft 130, is supplied, and the first mandrel 310 has a first region 311 and a proximal side and an axis of the first region 311. It has a second region 312 extending in the proximal direction from the proximal end of the first region 311 while overlapping in the direction, and a recess 313 is formed between the first region 311 and the second region 312. There is. Then, in the manufacturing method, the inner shaft 140 is arranged in the lumen 125 of the outer tip shaft 120, and the first region 311 of the first mandrel 310 is inserted into the lumen 145 of the inner shaft 140, whereby the inner shaft 140 is formed. The first mandrel 310 is arranged so that the base end vertically overlaps the recess 313 of the first mandrel 310, and the inner shaft 140 is aligned with the outer surface of the outer base end shaft 130, while the inner cavity 125 of the outer tip shaft 120 is placed. The outer proximal shaft 130 is arranged so that the inner cavity 135 of the outer proximal shaft 130 is connected to the outer proximal shaft 130, and the second mandrel 320 is inserted into the inner cavity 125 of the outer distal shaft 120 and the inner lumen 135 of the outer proximal shaft 130. A heat shrink tube 400 is arranged so as to cover the second region 312 of the outer tip shaft 120, the outer base shaft 130, the inner shaft 140, and the first mandrel 310, and heat is applied to the heat shrink tube 400 to shrink it. While fusing the outer tip shaft 120, the outer base end shaft 130, and the inner shaft 140, a convex portion 150 is formed at the base end of the inner shaft 140 arranged in the concave portion 313 of the first mandrel 310.

In the above method of manufacturing the shaft 100, when the inner shaft 140 and the outer shaft 110 are fused, the first region 311 included in the first mandrel 310 is inserted into the lumen 145 of the inner shaft 140, and the first mandrel 310 is inserted. The base end of the inner shaft 140 is arranged in the recess 313 formed between the first region 311 of the above and the second region 312 of the first mandrel 310, and the outer tip shaft 120, the outer base end shaft 130, and the inner shaft are arranged. The heat shrink tubing 400 is placed so as to cover the 140 and the second region 312 of the first mandrel 310. In the above manufacturing method, heat is applied to the heat-shrinkable tube 400 to shrink it, thereby fusing the outer tip shaft 120, the outer base end shaft 130, and the inner shaft 140 into the recess 313 of the first mandrel 310. A convex portion 150 is formed at the base end of the arranged inner shaft 140. Therefore, the manufacturing method can provide a shaft 100 including an inner shaft 140 having a protrusion 150 formed to prevent the inner shaft 140 from breaking near the proximal opening 105.

Further, in the method of manufacturing the shaft 100, the first mandrel 310 exposes the inner shaft 140 between the base end 123 of the outer tip shaft 120 and the tip of the second region 312 of the first mandrel 310. Placed in. Then, the portion of the inner shaft 140 exposed from the first mandrel 310 flows into the proximal end side of the inner shaft 140 so as to form a convex portion 150 when heat is applied to the heat shrink tube 400 to shrink the tube 400. A flexible portion 158 having a wall thickness thinner than that of the convex portion 150 is formed.

In the above manufacturing method of the shaft 100, the convex portion 150 can be formed on the inner shaft 140, and the flexible portion 158 can be formed on the tip end side of the inner shaft 140 with respect to the convex portion 150. When stress acts on the convex portion 150 from the guide wire 200 when the guide wire 200 is operated, the inner shaft 140 is deformed (bent) so that the vicinity of the convex portion 150 is rolled up from the flexible portion 158 as a starting point. , Prevents stress concentration from occurring near the proximal opening 105 of the inner shaft 140. Further, when the balloon catheter 10 is moved along the guide wire 200, the flexible portion 158 is easily curved to follow the guide wire 200, thereby enhancing the followability of the balloon catheter 10 to the guide wire 200.

Further, in the method of manufacturing the shaft 100, the recess 313 of the first mandrel 310 is formed in a shape in which the portion 313a facing the base end of the inner shaft 140 is curved. The base end of the inner shaft 140 is formed in a curved shape by the recess 313 of the first mandrel 310.

In the above method for manufacturing the shaft 100, the peripheral edge portion 105a of the proximal end opening 105 formed at the proximal end of the inner shaft 140 is formed in a curved cross-sectional shape (curved cross-sectional shape). Thereby, the operator can prevent the guide wire 200 from being caught on the peripheral edge portion 105a of the proximal end opening 105 when the guide wire 200 is taken out from the proximal end opening 105 of the inner shaft 140, and the guide wire 200 can be smoothly guided. It can be taken out.

Next, a modification of the above-described embodiment will be described. The configurations, members, manufacturing processes, and the like that are not particularly mentioned in the modified examples can be the same as those in the above-described embodiment, and the description thereof will be omitted.

<Modification example>
FIG. 8 is a cross-sectional view showing a convex portion 550 of the balloon catheter according to the modified example.

The balloon catheter according to the first modification is different from the balloon catheter 10 according to the above-described embodiment in the cross-sectional shape of the convex portion 550 formed on the inner shaft 140.

As shown in FIG. 8, the convex portion 550 formed on the inner shaft 140 has a first inclination that is inclined from the proximal end side toward the distal end side in the axial cross section (cross section shown in FIG. 7) of the inner shaft 140. It has a portion 551 and a second inclined portion 552 connected to the tip of the first inclined portion 551.

The first inclined portion 551 extends substantially linearly from the base end side to the tip end side of the inner shaft 140 at a predetermined inclination angle. The peripheral edge portion 105a of the proximal end opening 105 formed near the proximal end of the first inclined portion 551 is formed by a curved surface.

The second inclined portion 552 is inclined from the tip of the first inclined portion 551 toward the tip side of the inner shaft 140. In the cross-sectional view shown in FIG. 3, the tip of the first inclined portion 551 switches its cross-sectional shape from the first inclined portion 551 extending substantially linearly toward the curved second inclined portion 552 (transition). It exists at the boundary.

In the cross section shown in FIG. 3, the second inclined portion 552 extends from the tip of the first inclined portion 551 toward the tip end side of the inner shaft 140 so as to exhibit a cross-sectional shape different from that of the first inclined portion 551. Specifically, the base end side of the second inclined portion 552 has a cross-sectional shape that draws an arc from the tip end side of the first inclined portion 551 toward the tip end side. Further, the tip end side of the second inclined portion 552 exhibits a cross-sectional shape that draws an arc from the base end side of the second inclined portion 552 toward the outer surface side of the inner shaft 140 so as to be connected to the outer surface of the inner shaft 140. ing.

As shown in FIG. 8, the axial length L1 of the first inclined portion 551 of the convex portion 550 is formed to be shorter than the axial length L2 of the second inclined portion 552 of the convex portion 550. The axial length L1 of the first inclined portion 551 and the axial length L2 of the second inclined portion 552 are the axial lengths of the longest portion of the convex portion 550 on the cross section shown in FIG. Is.

The axial length L1 of the first inclined portion 551 of the convex portion 550 can be formed to be, for example, 0.1 mm to 0.8 mm, and the axial length L2 of the second inclined portion 552 of the convex portion 550 can be formed, for example. , 0.2 mm to 1.0 mm.

When forming the convex portion 550 according to the present modification, the operator prepares a mandrel having a concave portion having a cross-sectional shape corresponding to the cross-sectional shape of the convex portion 550 as the first mandrel. Similarly, in the case of forming the convex portions 650 and 750 according to each modification described later, the operator prepares a first mandrel having a cross-sectional shape corresponding to the cross-sectional shape of each convex portion 650 and 750.

As described above, in the balloon catheter according to the present modification, the convex portion 550 formed on the inner shaft 140 is a first inclined portion in which the convex portion 550 is inclined from the proximal end side toward the distal end side in the axial cross section of the inner shaft 140. It has a 551 and a second inclined portion 552 that is connected to the tip of the first inclined portion 551 and is inclined from the tip of the first inclined portion 551 toward the tip side of the inner shaft 140. The axial length of the first inclined portion 551 is shorter than the axial length of the second inclined portion 552.

In the balloon catheter, even when the convex portion 550 having a cross-sectional shape as described in this modification is formed on the inner shaft 140, when the guide wire 200 is taken out from the proximal opening 105 of the inner shaft 140, etc. It is possible to prevent the inner shaft 140 from breaking near the base end opening 105, and it is possible to prevent the operability of the guide wire 200 from deteriorating due to the breakage of the inner shaft 140.

In the balloon catheter according to the modified example of FIG. 8, the length L1 in the axial direction of the first inclined portion 551 of the convex portion 550 and the axial length L2 of the second inclined portion 552 of the convex portion 550 are the same. May have. Even in this case, the balloon catheter can prevent the inner shaft 140 from breaking near the proximal opening 105 when the guide wire 200 is taken out from the proximal opening 105 of the inner shaft 140, and the inner shaft 140 can be prevented from breaking. It is possible to prevent the operability of the guide wire 200 from being deteriorated due to the breakage of the guide wire 200.

<Modification example>
The specific cross-sectional shape of the convex portion formed on the inner shaft 140 is not particularly limited as long as the wall thickness increases from the base end side to the tip end side of the inner shaft 140. For example, as shown in FIG. 9, the convex portion 650 has a cross-sectional shape in which the first inclined portion 651 is inclined toward the tip end side and the second inclined portion 652 extends substantially perpendicularly in the direction orthogonal to the axial direction. It may have. Further, as shown in FIG. 10, the convex portion 750 may have a substantially rectangular cross-sectional shape in which the first inclined portion and the second inclined portion are not formed. Further, as shown in FIGS. 9 and 10, the inner shaft 140 does not have to have the peripheral edge portion 105a of the proximal end opening 105 formed in a curved surface (curved shape).

In the balloon catheter, even when the convex portions 650 and 750 are formed in the cross-sectional shape as shown in FIGS. 9 and 10, when the guide wire 200 is taken out from the proximal opening 105 of the inner shaft 140, etc. It is possible to prevent the inner shaft 140 from breaking near the base end opening 105, and it is possible to prevent the operability of the guide wire 200 from deteriorating due to the breakage of the inner shaft 140.

Although the method for manufacturing a balloon catheter and a medical long body according to the present invention has been described above through embodiments and the like, the present invention can be variously modified based on the description of the claims, and each of the described embodiments has been described. It is not limited to the contents of.

For example, the convex portion formed on the inner shaft is not particularly limited as long as it is formed on a part of the peripheral edge portion forming the base end opening of the inner shaft.

Further, for example, the structure of the balloon catheter and the arrangement of the members described in the embodiments and the like can be appropriately changed, the use of the additional members described in the illustration is omitted, and other additional members not particularly described. Various members can be used as appropriate. Similarly, each process related to the manufacturing method of the medical long body, the instruments used in the manufacturing, and the like can be appropriately changed.

This application is based on Japanese Patent Application No. 2017-063765 filed on March 28, 2017, the disclosure of which is cited in its entirety by reference.

10 Balloon catheter,
100 shaft (medical long body),
105 Base opening (base opening of inner shaft),
105a peripheral edge,
110 outer shaft,
115 Lumen of the outer shaft,
120 outer tip shaft,
123 Base end of outer tip shaft,
125 Lumen of the outer tip shaft,
126 Large diameter part,
127 small diameter part,
128 border,
130 outer base shaft,
135 Lumen of the outer proximal shaft,
140 inner shaft,
145 Inner shaft lumen,
150, 550, 650, 750 convex parts,
151, 551 first slope,
152, 552 second slope,
158 Flexible part,
160 balloons,
200 guide wire,
310 1st Mandrel,
311 1st area,
312 Second area,
313 recess,
313a The part facing the base end of the inner shaft,
320 Second Mandrel,
400 heat shrink tubing.

Claims (9)

An outer shaft comprising an outer tip shaft and an outer proximal shaft that is fixed to the proximal side of the outer distal shaft and has a lumen that communicates with the lumen of the outer distal shaft.
An inner shaft whose tip side is arranged in the lumen of the outer tip shaft and whose proximal side is arranged on the outer surface of the outer proximal shaft,
The inner shaft and the balloon fixed to the outer tip shaft are provided.
The proximal end of the inner shaft has a proximal opening that opens on the outer surface of the outer proximal shaft.
The inner shaft may have a convex portion in a part of the peripheral portion forming the proximal end opening portion,
The proximal end opening is arranged on the proximal end side with respect to the proximal end of the outer tip shaft.
The inner shaft is a balloon catheter having a flexible portion that is thinner than the convex portion and is flexible between the base end of the outer tip shaft and the convex portion. The balloon catheter according to claim 1 , wherein the proximal end opening is inclined from the proximal end side toward the distal end side in an axial cross section of the inner shaft. The outer tip shaft has a large diameter portion formed with a predetermined outer diameter.
The balloon catheter according to claim 1 or 2 , wherein the outer diameter formed by the outer shaft and the inner shaft at the portion corresponding to the convex portion is smaller than the outer diameter of the large diameter portion. The convex portion has a width along the axial direction of the inner shaft and has a width.
The balloon catheter according to any one of claims 1 to 3 , wherein the width of the convex portion increases toward the outer shaft side. The convex portion is connected to a first inclined portion inclined from the proximal end side toward the distal end side and the tip of the first inclined portion in the axial cross section of the inner shaft, and is connected to the tip of the first inclined portion from the tip of the first inclined portion. It has a second inclined portion that is inclined toward the tip end side of the inner shaft, and has.
The balloon catheter according to any one of claims 1 to 4 , wherein the axial length of the first inclined portion is longer than the axial length of the second inclined portion. The balloon catheter according to any one of claims 1 to 5 , wherein the peripheral edge of the proximal opening is formed of a curved surface. The outer tip shaft, the outer proximal shaft, the inner shaft, the first mandrel arranged in the lumen of the inner shaft, the lumen of the outer distal shaft and the lumen of the outer proximal shaft. Two mandrels are supplied, and the first mandrel extends axially from the proximal end side of the first region to the proximal end side of the first region while overlapping axially with the proximal end side of the first region. It has a second region, and a recess is formed between the first region and the second region.
The inner shaft is placed in the lumen of the outer tip shaft,
By inserting the first region of the first mandrel into the lumen of the inner shaft, the first mandrel is arranged so that the base end of the inner shaft overlaps the recess of the first mandrel in the axial direction.
The outer proximal shaft is arranged so that the lumen of the outer distal shaft and the lumen of the outer proximal shaft are connected to each other while the inner shaft is aligned with the outer surface of the outer proximal shaft.
The second mandrel is inserted into the lumen of the outer tip shaft and the lumen of the outer proximal shaft.
Heat shrink tubing is arranged to cover the outer tip shaft, the outer proximal shaft, the inner shaft, and the second region of the first mandrel.
Heat is applied to the heat-shrinkable tube to shrink it, and the outer tip shaft, the outer base end shaft, and the inner shaft are fused to the base end of the inner shaft arranged in the recess of the first mandrel. A method for manufacturing a medical long body including forming a convex portion. The first mandrel is placed on the inner shaft so as to expose the inner shaft between the base end of the outer tip shaft and the tip of the second region of the first mandrel.
The portion of the inner shaft exposed from the first mandrel flows into the proximal end side of the inner shaft so as to form the convex portion when heat is applied to the heat-shrinkable tube to shrink the convex portion. The method for manufacturing a long medical body according to claim 7 , wherein a flexible portion having a wall thickness thinner than that of the portion is formed. The recess of the first mandrel is formed in a shape in which a portion facing the base end of the inner shaft is curved.
The proximal end of the inner shaft is formed in a curved shape by the recess, the production method of the medical long body according to claim 7 or claim 8.

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