Protective sheath and medical instrument set

Abstract

To provide: a protective sheath capable of appropriately protecting a treatment part and a distal tip of a medical elongated body, and achieving reduction in a manufacturing cost and simplification of manufacturing operation; and a medical instrument set.SOLUTION: A protective sheath 100 comprises an outer tube 110 including a first lumen 115, and an inner tube 120 stored in the first lumen, where the outer tube and the inner tube are fixed. A first storage area 101 for storing a treatment part 450 of a medical elongated body 300 is formed in at least a part between a base end and a tip of the outer tube. The inner tube is disposed in at least a part of a second storage area 102 located on the tip side of the first storage area, where the inner tube includes a second lumen 125 having a diameter φ2 smaller than the outer diameter D4 of the treatment part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a protective sheath and a medical instrument set. [Background technology]

[0002] Medical elongated bodies such as catheters having a long shaft portion are protected using specified protective devices to prevent the medical elongated body from being damaged or scratched until they are used in the medical field (after manufacture, during transportation and storage).

[0003] A treatment section for implementing a predetermined treatment using the medical elongated body is disposed near the distal end of the medical elongated body. For example, in the case of a balloon catheter, a balloon functioning as the treatment section is disposed near the distal end of the elongated shaft. The medical elongated body also has a distal tip disposed on the distal end side of the treatment section for preventing the medical elongated body from hitting the inner wall of the biological lumen and causing damage to the biological lumen when the medical elongated body is operated within the biological lumen (e.g., blood vessel). In general, the distal tip is made of a flexible resin material so as to be able to perform the above-mentioned functions.

[0004] For storing a medical elongate body having the above-mentioned treatment portion and distal tip, for example, Patent Document 1 proposes a protective sheath (protective tube) having a hollow structure that covers and protects the treatment portion and the distal tip. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2018-50729 Summary of the Invention [Problem to be solved by the invention]

[0006] By using the protective sheath described in Patent Document 1, it becomes possible to adequately protect the treatment section and the distal tip that are provided in the medical elongated body.

[0007] On the other hand, while it is assumed that the protective sheath has a configuration capable of protecting the treatment section and the distal tip, it can also be said to be an important issue to devise ways to reduce manufacturing costs and simplify the manufacturing work.

[0008] The present invention aims to provide a protective sheath and a medical instrument set that can adequately protect the treatment portion and distal tip of a medical elongated body, and that can reduce manufacturing costs and simplify manufacturing operations. [Means for solving the problem]

[0009] The present invention can be achieved by any one of the following means (1) to (8).

[0010] (1) A protective sheath to be attached to a medical elongate body having a shaft portion, a distal tip disposed at the distal end of the shaft portion, and a treatment portion disposed on the proximal end side of the distal tip for performing a predetermined treatment within a biological organ, the protective sheath comprising an outer tube having a first lumen and an inner tube accommodated in the first lumen, the outer tube and the inner tube being fixed, a first accommodating area for accommodating the treatment portion being formed in at least a portion between the proximal end and the distal end of the outer tube, the inner tube being arranged in at least a portion of a second accommodating area located distal to the first accommodating area, and the inner tube having a second lumen having a diameter smaller than the outer diameter of the treatment portion.

[0011] (2) A protective sheath as described in (1) above, wherein the diameter of the second lumen is larger than the outer diameter of the tip of the distal tip.

[0012] (3) The protective sheath described in (2) above, wherein the base end of the inner tube constitutes a holding portion that holds at least a portion of the distal tip within the second lumen by abutting against a portion of the distal tip or a portion of the medical elongate body that is located proximal to the distal tip.

[0013] (4) The protective sheath according to any one of (1) to (3) above, wherein the base end of the outer tube has a flared structure in which the outer diameter and the inner diameter increase toward the base end side.

[0014] (5) The protective sheath according to any one of (1) to (4) above, wherein the base end of the inner tube has a flared structure in which the outer diameter and the inner diameter increase toward the base end side.

[0015] (6) The protective sheath according to any one of (1) to (5) above, wherein a portion of the outer tube is fixed to the inner tube while being recessed towards the inner tube.

[0016] (7) A protective sheath described in any one of (1) to (6) above, wherein the inner tube has a colored portion colored a predetermined color, and the outer tube is colored in a lighter color than the colored portion or is transparent.

[0017] (8) A medical instrument set comprising: the protective sheath described in any one of (1) to (7) above; and the medical elongated body to which the protective sheath is attached, wherein the medical elongated body is a balloon catheter having an expandable and contractible balloon, or a stent delivery catheter having a stent mounted on the balloon, and the treatment portion is a straight portion of the balloon that has a substantially linear cross-sectional shape when the balloon is expanded, or the stent in an unexpanded state. Effect of the Invention

[0018] The protective sheath described in (1) above, when the medical elongated body is housed in the protective sheath, can protect the treatment part in a first housing area formed in the first lumen of the outer tube, while protecting a part (e.g., a distal tip) of the medical elongated body located distal to the treatment part in a second housing area located distal to the first housing area. The protective sheath has a simple structure composed of two tubes, an outer tube and an inner tube housed in the first lumen of the outer tube. Therefore, the protective sheath can be manufactured by a simple manufacturing process of housing an inner tube having an outer diameter and an inner diameter smaller than the outer tube in the first lumen of the outer tube. Therefore, the protective sheath can appropriately protect the treatment part and the distal tip of the medical elongated body, and can reduce manufacturing costs and simplify manufacturing processes. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a medical instrument set according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a medical instrument set according to an embodiment, and is a partial cross-sectional view showing an enlarged view of the vicinity of a distal end of a protective sheath and a medical elongated body. [Diagram 3] 3A is a cross-sectional view (axially orthogonal cross-sectional view) of a portion indicated by arrows 3A-3A in FIG. 2. [Figure 4] FIG. 2 is a diagram showing a medical instrument set according to an embodiment, and is an enlarged view showing the vicinity of a distal end portion of a protective sheath and a medical elongated body. [Diagram 5] 13 is a cross-sectional view showing a state in which the protective sheath according to the first modification is disassembled. FIG. [Figure 6] 11 is an enlarged partial cross-sectional view showing the vicinity of the distal end of a protective sheath and a medical elongated body according to Modification 2. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0021] FIG. 1 is a diagram showing the overall configuration of a medical instrument set 10 according to an embodiment, FIG. 2 is a partial cross-sectional view showing the inside of a protective sheath 100 according to an embodiment, FIG. 3 is an axial cross-sectional view taken along arrows 3A-3A shown in FIG. 2, and FIG. 4 is a partial enlarged view showing the protective sheath 100 and the tip portion of a medical elongated body 300 as viewed from the outside.

[0022] <Medical Instrument Set 10> As shown in FIG. 1, a medical instrument set 10 according to this embodiment includes a protective sheath 100 and an elongated medical body 300 to which the protective sheath 100 is attached.

[0023] The medical elongated body 300 is a medical instrument used to perform a predetermined treatment (e.g., therapy, diagnosis, etc.) on each part of a biological organ by the treatment section 450. The protective sheath 100 is used for the purpose of protecting the treatment section 450 and the distal tip 440 disposed at the distal end of the medical elongated body 300.

[0024] The medical elongated body 300 can be inserted into a catheter holder (not shown) known in the field of medical products with the protective sheath 100 attached to the distal end portion. The catheter holder can be formed, for example, of a hollow tube member wound into a circular ring shape.

[0025] 1 and 2, the medical elongated body 300, when inserted into the protective sheath 100, can be locked to the protective sheath 100 using a specific core bar (stylet) 200. The core bar 200 includes a main body portion 201 that is inserted into a guidewire lumen 415 of a shaft portion 410 of the medical elongated body 300, and a locking portion (ring portion) 203 that is disposed at the tip portion of the main body portion 201 and enables the core bar 200 to be grasped by fingers or the like when inserting or removing the core bar 200 from the medical elongated body 300.

[0026] The core metal 200 can be made of, for example, a predetermined metal material. There is no particular limitation on the specific structure of the core metal 200 (external shape, length, cross-sectional shape of each portion, thickness, etc.).

[0027] <Medical Long Body 300> As shown in FIG. 2, the medical elongated body 300 can be composed of a catheter having a shaft portion 410, a distal tip 440 arranged at the distal end of the shaft portion 410, and a treatment portion 450 arranged on the base end side of the distal tip 440 for performing a specified treatment on a biological organ.

[0028] In this embodiment, as an example of a medical elongated body 300, a stent delivery catheter 400 including an expandable and contractable balloon 460 and a stent 500 mounted on the balloon 460 will be described.

[0029] The medical elongated body 300, which is the subject of use of the protective sheath 100, is not particularly limited in terms of its specific structure or product type, as long as it includes a shaft portion 410, a distal tip 440, and a treatment portion 450. The medical elongated body 300 can also be configured as, for example, a balloon catheter without a stent 500, an intravascular optical coherence tomography catheter (OCT catheter) including a head portion in which a sensor is disposed, an intravascular ultrasound catheter (IVUS catheter) including a head portion in which an ultrasound transducer is disposed, an atherectomy device including a treatment blade at the distal end, or the like.

[0030] In this specification, the side of the stent delivery catheter 400 that is introduced into the living body (the side where the distal tip 440 is arranged) is referred to as the distal side, and the end portion of each member and component located on the distal side is referred to as the "distal portion". Furthermore, the side of the stent delivery catheter 400 where the hub portion 470 is arranged is referred to as the proximal side, and the end portion of each member and component located on the proximal side is referred to as the "proximal portion". Furthermore, the direction from the distal portion to the proximal portion (or from the proximal portion to the distal portion) is referred to as the "axial direction (longitudinal direction)". The above definitions of the distal side (distal portion), proximal side (proximal portion), and axial direction also apply to the positions and directions of each end portion of the protective sheath 100.

[0031] As shown in FIGS. 1 and 2, the stent delivery catheter 400 includes a distal tip 440 disposed at the distal end of a shaft portion 410 , and a balloon 460 disposed on the base end side of the distal tip 440 .

[0032] The distal tip 440 is disposed for the purpose of preventing damage to a biological organ (such as the inner wall of a blood vessel) when the distal end of the stent delivery catheter 400 comes into contact with the biological organ.

[0033] As shown in FIG. 3, the distal tip 440 is made of a hollow member having an inner cavity 445 through which a guide wire can be inserted.

[0034] The tip 440 can be made of, for example, a material that is more flexible than the shaft portion 410. The tip 440 can be made of, for example, a polymer material such as polyolefin (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture of these, or a multi-layer tube of two or more of the above polymer materials.

[0035] 1 and 2, the balloon 460 is fixed near the tip of the shaft portion 410. At the base end of the shaft portion 410, a hub portion 470 is arranged to which an indeflator can be connected for supplying various fluids (pressurized media) to the balloon 460 and discharging fluids from the balloon 460.

[0036] 2, in this embodiment, the shaft portion 410 includes an outer shaft 420 and an inner shaft 430. The inner shaft 430 is inserted into an inner cavity (not shown) of the outer shaft 420.

[0037] The distal end of the inner shaft 430 protrudes a predetermined length toward the distal side beyond the outer shaft 420. The distal end of the balloon 460 is fixed to the distal end of the inner shaft 430, and the proximal end is fixed to the distal end of the outer shaft 420.

[0038] A lumen for a pressurized medium that communicates with the interior of the balloon 460 is defined between the inner shaft 430 and the outer shaft 420 .

[0039] The stent delivery catheter 400 is configured as a so-called rapid exchange type catheter. As shown in Fig. 1, the base end of the inner shaft 430 forms a guidewire port 417 which serves as an entrance and exit for inserting a guidewire into the shaft portion 410. The inner cavity of the inner shaft 430 forms a guidewire lumen 415 through which a guidewire can be inserted.

[0040] The outer shaft 420 and the inner shaft 430 can be formed from, for example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer; thermoplastic resins such as soft polyvinyl chloride; various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer; and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene.

[0041] It should be noted that the details of the members, structures, and the like of the stent delivery catheter 400 that are not described here may be any known structure.

[0042] As shown in FIG. 2, balloon 460 has a tip side tapered portion 461 having a cross-sectional shape that is inclined in a direction approaching the central axis of shaft portion 410 toward the tip side, a base side tapered portion 463 having a cross-sectional shape that is inclined in a direction approaching the central axis of shaft portion 410 toward the base side, and a straight portion 465 arranged between tip side tapered portion 461 and base side tapered portion 463.

[0043] 2 and 4 show the balloon 460 in an expanded state for the sake of simple explanation of the present invention. However, in reality, the balloon 460 is prepared in a state where it is folded into a predetermined shape and wrapped around the shaft portion 410 with the protective sheath 100 attached. The folded shape of the balloon 460, the state where it is wrapped around the shaft portion 410, and the like may be appropriately selected from configurations known in the field of balloon catheters.

[0044] The balloon 460 can be formed from, for example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers, thermoplastic resins such as polyurethane, polyamides, polyamide elastomers, polystyrene elastomers, silicone rubber, latex rubber, etc.

[0045] In this embodiment, the treatment portion 450 to be protected by the protective sheath 100 is composed of a stent 500 mounted on a straight portion 465 of a balloon 460 that has a substantially linear cross-sectional shape when the balloon 460 is expanded.

[0046] In the stent delivery catheter 400 according to this embodiment, a stent 500 in an unexpanded state is mounted (placed) on a straight portion 465 of a balloon 460 in an unexpanded state. When the balloon 460 expands in a living organ, the stent 500 expands following the expansion of the balloon 460. After the stent 500 expands in accordance with the expansion of the balloon 460, the balloon 460 is deflated, whereby the stent 500 can be placed at a treatment target site (e.g., a stenosis site, etc.) in a blood vessel. There is no particular limitation on the specific configuration of the stent 500 (stent design, constituent material, presence or absence of drug application, etc.).

[0047] By disposing the straight portion 465 inside the protective sheath 100 (the first storage area 101 described later), the protective sheath 100 appropriately protects the stent 500 together with the straight portion 465 from the outside until the stent delivery catheter 400 is used in a medical setting.

[0048] In addition, when the medical elongated body 300 is configured as a balloon catheter not equipped with the stent 500, the treatment section 450 can be configured as a straight part 465 of the balloon 460 that realizes a predetermined treatment (application of pressure force, etc.) for a stenosed part of a biological lumen such as a blood vessel. For example, when the medical elongated body 300 is configured as an intravascular optical coherence tomography catheter, the treatment section 450 can be configured as a head part in which a sensor is arranged. Also, for example, when the medical elongated body 300 is configured as an intravascular ultrasonic catheter, the treatment section 450 can be configured as a head part in which an ultrasonic transducer is arranged. Also, for example, when the medical elongated body 300 is configured as an atherectomy device, the treatment section 450 can be configured as a treatment blade arranged at the tip.

[0049] <Protective sheath 100> As shown in FIGS. 1 to 4, the protective sheath 100 has an outer tube 110 having a first lumen 115 and an inner tube 120 housed in the first lumen 115.

[0050] Outer tube 110 is made of a hollow member having a distal end 111, a proximal end 113, and a first lumen 115 extending between distal end 111 and proximal end 113.

[0051] A tip opening 111a that connects the first lumen 115 to the outside is formed at the tip (most end) of the outer tube 110. In addition, a base opening 113a that connects the first lumen 115 to the outside is formed at the base end (most base end) of the outer tube 110.

[0052] 2 and 4, a first accommodating region 101 for accommodating a treatment portion 450 (stent 500) of a stent delivery catheter 400 is formed at least partially between the base end and the tip end of the outer tube 110. A second accommodating region 102 is formed at least partially between the tip end of the first accommodating region 101 and the tip end of the outer tube 110. The outer tube 110 and the inner tube 120 are fixed together.

[0053] As shown in FIGS. 2 and 4, proximal end 113 of outer tube 110 can be configured to have a flared structure in which the outer diameter and inner diameter increase toward the proximal end.

[0054] Since the base end 113 of the outer tube 110 constituting the base end of the protective sheath 100 has the above-mentioned flared structure, when the stent delivery catheter 400 is inserted into the protective sheath 100 (the first lumen 115 of the outer tube 110), the insertion operation can be performed smoothly. Also, the distal tip 440 arranged at the distal end of the stent delivery catheter 400 can be suitably prevented from hitting the proximal end 113 of the outer tube 110, thereby preventing the distal tip 440 from being scratched.

[0055] The inner tube 120 is formed of a hollow member having a distal end 121, a proximal end 123, and a second lumen 125 extending between the distal end 121 and the proximal end 123.

[0056] A tip opening 121a that communicates between the second lumen 125 and the outside is formed at the tip (most distal end) of the inner tube 120. Also, a base opening 123a that communicates between the second lumen 125 and the outside is formed at the base end (most proximal end) of the inner tube 120.

[0057] 2 and 4, the inner tube 120 is disposed in at least a part of the second accommodating region 102 located distally of the first accommodating region 101. That is, the inner tube 120 is disposed in the first lumen 115 of the outer tube 110 at a position corresponding to the second accommodating region 102.

[0058] 2, the axial length of the outer tube 110 can be formed to be greater than the axial length of the inner tube 120. By forming the axial length of the outer tube 110 to be greater than the axial length of the inner tube 120, it is possible to prevent the inner tube 120 from being disposed so as to straddle the second accommodating region 102 and the first accommodating region 101, or from being disposed so as to protrude to the outside of the first lumen 115 through the tip opening 121a of the outer tube 110, in a state in which the inner tube 120 is disposed in the second accommodating region 102 of the outer tube 110.

[0059] 2, the inner tube 120 can be arranged such that, when the inner tube 120 is arranged in the second accommodation area 102 of the outer tube 110, the tip portion 121 is located a predetermined distance away from the tip of the outer tube 110 toward the base end of the outer tube 110. Note that the tip of the inner tube 120 may be arranged at approximately the same position as the tip of the outer tube 110 (a position overlapping with the opening surface of the tip opening 121a), for example, as shown in Modification 2 (see FIG. 6). In other words, the position at which the tip portion 121 of the inner tube 120 is arranged can be set to any position within the second accommodation area 102.

[0060] Fig. 3 shows an orthogonal cross-sectional view taken along the line 3A-3A shown in Fig. 2. Here, the relationship between the inner diameter and the outer diameter of each member will be described.

[0061] 3, the outer tube 110 has an outer diameter D1 and an inner diameter (diameter of the first lumen 115) φ1. The outer diameter D1 and the inner diameter φ1 of the outer tube 110 refer to the outer diameter and the inner diameter of the portion other than the base end portion 113 configured in a flared structure.

[0062] The inner tube 120 has an outer diameter D2 and an inner diameter (the diameter of the second lumen 125) φ2.

[0063] Distal tip 440 has an outer diameter D3.

[0064] The treatment portion 450 (the stent 500 in an unexpanded state mounted on the straight portion 465 of the balloon 460) has an outer diameter D4 when the balloon 460 is in an unexpanded state (contracted state).

[0065] In this embodiment, the inner diameter φ2 of the inner tube 120 is smaller than the outer diameter D4 of the treatment portion 450. Therefore, as shown in Figs. 2 and 4, in a state in which the inner tube 120 is disposed in the second accommodation region 102 of the outer tube 110 and the treatment portion 450 is disposed in the first accommodation region 101 of the outer tube 110, when the stent delivery catheter 400 attempts to move toward the distal end side of the outer tube 110, the treatment portion 450 can be prevented from moving into the second lumen 125 of the inner tube 120. Therefore, the protective sheath 100 can stably maintain a state in which the treatment portion 450 is held in the first accommodation region 101.

[0066] In this embodiment, the inner diameter φ2 of the second lumen 125 of the inner tube 120 is larger than the outer diameter D3 of the distal tip 440. Therefore, in a state where the treatment section 450 is disposed in the first housing area 101 of the outer tube 110, the distal tip 440 can be disposed in the second lumen 125 of the inner tube 120 disposed in the second housing area 102 located on the distal side of the first housing area 101. The protective sheath 100 holds the distal tip 440 in the second lumen 125 of the inner tube 120, thereby preventing the distal tip 440 from coming into contact with other articles, etc.

[0067] In addition, in this embodiment, the base end 123 of the inner tube 120 forms a holding portion that holds the tip tip 440 within the second lumen 125 of the inner tube 120 by abutting a part of the tip tip 440 or a part located closer to the base end than the tip tip 440 in the stent delivery catheter 400.

[0068] In this specification, the above-mentioned "holding portion" means a portion where a part of the distal end taper portion 461 located on the distal side of the treatment section 450 or a part of the distal tip 440 contacts the proximal end 123 of the inner tube 120, and more specifically, means the proximal end (the most proximal end) of the proximal end 123 where the above-mentioned parts of the inner tube 120 contact, or a part of the inner surface of the proximal end 123.

[0069] When the distal tip 440 is configured to have a tapered shape in which the outer diameter gradually decreases toward the distal end side, the inner diameter φ2 of the inner tube 120 can be formed to be smaller than the outer diameter D4 of the treatment section 450 and larger than the outer diameter of the distal end surface of the distal tip 440. In other words, when the distal tip 440 has the above-mentioned tapered shape, the base end surface of the inner tube 120 or the inner surface (inner circumferential surface) of the base end portion 123 is arranged to abut against any part of the tapered portion of the distal tip 440.

[0070] Specifically, the inner diameter φ2 of the inner tube 120 can be formed to be smaller than the outer diameter D4 of the treatment section 450 and larger than the outer diameter of any part of the distal end taper section 461 located on the distal end side of the treatment section 450. Therefore, as shown in FIG. 2, in a state in which the distal tip 440 is disposed in the second lumen 125 of the inner tube 120 and the treatment section 450 is disposed in the first accommodation region 101 of the outer tube 110, a part of the distal end taper section 461 abuts against the proximal end section 123 of the inner tube 120. The proximal end section 123 of the inner tube 120 restricts the movement of the stent delivery catheter 400 to the distal side beyond the proximal end section 123 by the abutment of the distal end taper section 461. Therefore, the protective sheath 100 can effectively prevent the treatment section 450 from moving from the first accommodation region 101 to the second accommodation region 102.

[0071] Each part of the medical instrument set 10 can be configured, for example, with the following dimensions:

[0072] The length of the outer tube 110 along the axial direction (synonymous with the length of the protective sheath 100 along the axial direction) can be formed to be, for example, 20 mm to 1000 mm.

[0073] When the length along the axial direction of outer tube 110 is formed to the above dimensions, the portion of outer tube 110 having a flared structure can be formed, for example, in the range of 0 mm to 100 mm from the base end toward the tip end.

[0074] When the length along the axial direction of the outer tube 110 is formed to have the above dimensions, the length along the axial direction of the inner tube 120 can be formed to be, for example, 5 mm to 200 mm.

[0075] The outer tube 110 may have an outer diameter D1 of, for example, 0.50 mm to 3.00 mm, and an inner diameter φ1 of, for example, 0.40 mm to 2.90 mm.

[0076] When the elongated medical body 300 is configured as a stent delivery catheter 400 as in this embodiment, the outer diameter D4 of the treatment section 450 is the outer diameter of the stent 500 in an unexpanded state mounted on the straight portion 465 of the balloon 460. When the elongated medical body 300 is configured as a balloon catheter (e.g., a PTCA balloon catheter) not equipped with the stent 500, the outer diameter of the treatment section 450 is the outer diameter of the straight portion 465 of the balloon 460 in an unexpanded state.

[0077] When the inner diameter φ1 of the outer tube 110 is formed to have the above dimensions, the outer diameter D2 of the inner tube 120 can be formed to be, for example, 0.30 mm to 2.80 mm. Also, the inner diameter φ2 of the inner tube 120 can be formed to be, for example, 0.20 mm to 2.70 mm.

[0078] As shown in FIG. 2, a portion of the outer tube 110 is fixed to the inner tube 120 while being recessed towards the inner tube 120 (the central axis side of the protective sheath 100).

[0079] 2, a fused portion 130 is formed at a location where the outer tube 110 and the inner tube 120 are fused. Moreover, on the outer surface of the outer tube 110, in the vicinity of where the fused portion 130 is formed, a recess 117 is formed in which the outer surface of the outer tube 110 is recessed toward the inner tube 120.

[0080] In the protective sheath 100, the outer tube 110 and the inner tube 120 are fixed to each other so that the relative positions of the outer tube 110 and the inner tube 120 do not change when the inner tube 120 is housed in the outer tube 110. The outer tube 110 and the inner tube 120 are fixed in an engaged state such that the vicinity of the recess 117 formed in the outer tube 110 abuts against the outer surface of the inner tube 120, and therefore the fixing force between them is suitably improved. There is no particular limitation on the method for fixing the outer tube 110 and the inner tube 120, but for example, a method can be adopted in which, when the inner tube 120 is housed in the outer tube 110, heat is applied from the outside of the outer tube 110 to fuse a part of the outer tube 110 to the inner tube 120. By employing such a method, in a state in which the inner tube 120 is housed in the outer tube 110 and the two components are assembled, the outer tube 110 and the inner tube 120 can be fixed together by a simple method of applying heat from the outside, and the protective sheath 100 can be manufactured. As a fusion method in which heat is applied from the outside, for example, a known method such as a high-frequency sealer or laser fusion can be used.

[0081] The method of fixing the outer tube 110 and the inner tube 120 is not limited to fusion, and other methods may be used, such as fixing using an adhesive, or adjusting the inner and outer diameters of each tube 110, 120 and fixing them by utilizing the frictional force generated between the inner surface of the outer tube 110 and the outer surface of the inner tube 120.

[0082] The material constituting the outer tube 110 and the inner tube 120 is not particularly limited, but may be, for example, a known resin material. There is also no particular limit to the specific type of resin material, but when the above-mentioned fixing method by fusion is adopted, for example, polyethylene, polypropylene, nylon, PTFE, etc. can be suitably used.

[0083] For example, a protective sheath used for protecting a medical elongated object has a single tube structure manufactured using a heat shrink tube. As an example of a manufacturing method of such a protective sheath, the following procedure may be adopted. An operator prepares a single hollow tube, a core bar to be inserted into the hollow tube, and a shape-retaining mandrel into which the core bar is inserted and which is inserted into the hollow tube, and in a state in which the core bar and the shape-retaining mandrel are inserted into the hollow tube, places a heat shrink tube so as to cover the outer circumferential surface of the hollow tube, and heats a part of the heat shrink tube to give a predetermined cross-sectional shape (a stepped cross-sectional shape that can prevent the medical elongated object from moving inside the hollow tube) to the hollow tube, thereby manufacturing the protective sheath. In this method, the cross-sectional shape of the hollow tube is formed by utilizing the pressure applied when the heated heat shrink tube shrinks as described above, so that the quality of the manufactured protective sheath is likely to vary due to, for example, individual differences in the heat shrink tube, the temperature of the applied heat, and a slight deviation in the setting position of the core bar. Furthermore, since a heat shrink tube is used each time a protective sheath is manufactured, the material costs of the heat shrink tube and the heating process are required, making it difficult to reduce manufacturing costs.

[0084] In contrast to the manufacturing method described above, the protective sheath 100 according to this embodiment can be manufactured as a multi-tube (multi-layer) protective sheath 100 by simply housing (inserting) the inner tube 120 into the outer tube 110 and fixing the relative positions of the two. This eliminates the need to use a heat shrink tube, which can be a factor in causing variation in the product quality of the protective sheath 100. This makes it possible to improve product quality and reduce manufacturing costs.

[0085] As shown in Fig. 4, the inner tube 120 has a colored portion 128 that is colored a predetermined color. In Fig. 4, the colored portion 128 of the inner tube 120 is marked with a dot for clarity.

[0086] The outer tube 110 may be colored a lighter color than the colored portion 128 or may be transparent.

[0087] In the protective sheath 100, the inner tube 120 has a colored portion 128, and the outer tube 110 is colored in a lighter color than the colored portion 128 or is formed transparent, so that workers who handle the tubes 110, 120 during the manufacturing process can easily distinguish the inner tube 120 from the outer tube 110 by visual inspection. This makes it possible to prevent workers from mistakenly handling the outer tube 110 and the inner tube 120.

[0088] In addition, in the protective sheath 100, the inner tube 120 includes a colored portion 128, and the outer tube 110 is colored in a lighter color than the colored portion 128 or is formed transparent, so that the inner tube 120 and a part of the stent delivery catheter 400 can be visually confirmed from outside the outer tube 110 when the inner tube 120 is housed in the outer tube 110, as shown in Fig. 4. Therefore, by visually checking the protective sheath 100 at a manufacturing site or a medical site, it can be easily confirmed that the treatment portion 450 of the stent delivery catheter 400 disposed in the outer tube 110 is appropriately disposed in the first housing region 101, as well as the position of the inner tube 120.

[0089] The colored portion 128 does not have to be provided over the entire inner tube 120. For example, the colored portion 128 may be provided over a portion of the axial direction or a portion of the circumferential direction of the inner tube 120. There are no particular limitations on the specific color of the colored portion 128, but for example, the colored portion 128 can be colored red.

[0090] The specific color of the outer tube 110 is not particularly limited, but for example, if the inner tube 120 is red, the inner tube 120 can be made of a light white color that can be seen from outside the outer tube 110, or transparent (including translucent).

[0091] As described above, the protective sheath 100 according to this embodiment is a protective sheath attached to a medical elongated body 300 having a shaft portion 410, a distal tip 440 disposed at the distal end of the shaft portion 410, and a treatment portion 450 disposed on the proximal end side of the distal tip 440 for performing a predetermined treatment in a living organ. The protective sheath 100 has an outer tube 110 having a first lumen 115 and an inner tube 120 accommodated in the first lumen 115, the outer tube 110 and the inner tube 120 are fixed, a first housing region 101 for housing the treatment portion 450 is formed in at least a part from the proximal end to the distal end of the outer tube 110, the inner tube 120 is disposed in at least a part of a second housing region 102 located distally of the first housing region 101, and the inner tube 120 has a second lumen 125 having a diameter φ2 smaller than the outer diameter D4 of the treatment portion 450.

[0092] In the protective sheath 100 according to this embodiment, in a state in which the medical elongated body 300 is accommodated in the protective sheath 100, the first accommodation region 101 formed in the first lumen 115 of the outer tube 110 protects the treatment portion 450, while the second accommodation region 102 located on the distal side of the first accommodation region 101 protects a portion of the medical elongated body 300 located on the distal side of the treatment portion 450 (for example, the distal tip 440). In addition, the protective sheath 100 has a simple structure constituted by two tubes, the outer tube 110 and the inner tube 120 accommodated in the first lumen 115 of the outer tube 110. Therefore, the protective sheath 100 can be manufactured by a simple manufacturing operation of accommodating the inner tube 120 having an outer diameter and an inner diameter smaller than those of the outer tube 110 in the first lumen 115 of the outer tube 110. Therefore, the protective sheath 100 can adequately protect the treatment section 450 and the distal tip 440 of the elongated medical body 300, and can also reduce manufacturing costs and simplify manufacturing operations.

[0093] Furthermore, according to the medical instrument set 10 including the protective sheath 100 and the medical elongated body 300, it is possible to provide the medical elongated body 300 in which the treatment portion 450 and the distal tip 440 are suitably prevented from being scratched or otherwise damaged during transportation or storage.

[0094] Next, a modified example of the embodiment described above will be described. Explanations of the same configurations and members as those already described will be omitted as appropriate. Furthermore, contents that are not specifically described can be configured in the same way as the embodiment described above.

[0095] <Variation 1> FIG. 5 shows an exploded cross-sectional view of a protective sheath 100A according to the first modification (a cross-sectional view of the state before the inner tube 120 is housed in the outer tube 110).

[0096] In the protective sheath 100A according to the first modification, the base end 123 of the inner tube 120 is configured to have a flared structure in which the inner diameter and the outer diameter become wider toward the base end side. That is, as shown in FIG. 5, the base end 123 of the inner tube 120 is processed to have a flared structure at a stage before the inner tube 120 is housed in the first lumen 115 of the outer tube 110.

[0097] Since the inner tube 120 of the protective sheath 100A is configured as described above, it becomes possible to smoothly accommodate the distal tip 440 in the second lumen 125 of the inner tube 120. In addition, when accommodating the distal tip 440 in the second lumen 125 of the inner tube 120, it is possible to prevent the distal tip 440 from hitting the base end portion 123 of the inner tube 120 and causing damage thereto.

[0098] <Variation 2> FIG. 6 shows a cross-sectional view of a protective sheath 100B according to the second modification.

[0099] In the protective sheath 100B according to the second modification, the tip (most end) of the inner tube 120 is disposed at approximately the same position as the tip of the outer tube 110. As shown in this modification, the position at which the tip of the inner tube 120 is disposed is not particularly limited as long as it is within the second accommodating region 102 of the outer tube 110, and the tip can be disposed at any position within the second accommodating region 102.

[0100] The protective sheath and medical instrument set according to the present invention have been described above through embodiments and modifications thereof. However, the present invention is not limited to the configurations described in the embodiments and modifications, and may be modified as appropriate based on the description of the claims. [Explanation of symbols]

[0101] 10 Medical Instrument Sets 100 Protective sheath 100A protective sheath 100B Protective sheath 101 First Containment Area 102 Second Containment Area 110 Outer tube 111 Tip of outer tube 113 Proximal end of outer tube 115 1st lumen 117 Recess 120 Inner Tube 121 Tip of inner tube 123 Proximal end of inner tube 125 2nd Lumen 128 Colored section 130 Fusion part 200 Core wire 201 Main body 203 Locking part 300 Medical long body 400 Stent delivery catheter 410 Shaft section 440 Tip 450 Treatment department 460 Balloon 461 Tip side tapered part 463 Base end taper 465 Straight section 470 Hub 500 stents D1 Outer shaft outer diameter D2 Outside diameter of inner shaft D3 Outer diameter of tip D4 Outer diameter of treatment part φ1 Inner diameter of outer shaft φ2 Inner shaft inner diameter

Claims

1. A protective sheath to be attached to a medical elongated body having a shaft portion, a distal tip disposed at a distal end of the shaft portion, and a treatment portion disposed on a proximal end side of the distal tip for performing a predetermined treatment in a biological organ, an outer tube having a first lumen; an inner tube received in the first lumen; The outer tube and the inner tube are fixed, a first accommodation region for accommodating the treatment portion is formed in at least a portion between the base end and the tip end of the outer tube, the inner tube is disposed in at least a portion of a second housing area located distally of the first housing area, The inner tube has a second lumen having a diameter smaller than the outer diameter of the treatment portion.

2. The protective sheath of claim 1 , wherein the diameter of the second lumen is greater than an outer diameter of the distal end of the distal tip.

3. 3. The protective sheath according to claim 2, wherein the base end of the inner tube constitutes a retaining portion that retains at least a portion of the distal tip within the second lumen by abutting against a portion of the distal tip or a portion of the medical elongate body that is located proximal to the distal tip.

4. The protective sheath according to claim 1 , wherein the proximal end of the outer tube has a flared structure in which the outer diameter and the inner diameter increase toward the proximal end.

5. The protective sheath according to claim 1 , wherein the proximal end of the inner tube has a flared structure in which the outer diameter and the inner diameter increase toward the proximal end.

6. The protective sheath according to claim 1 , wherein a portion of the outer tube is fixed to the inner tube while being recessed toward the inner tube.

7. The inner tube has a colored portion that is colored a predetermined color, The protective sheath of claim 1 , wherein the outer tube is colored a lighter color than the colored portion or is transparent.

8. The protective sheath according to any one of claims 1 to 7; The medical elongated body having the protective sheath attached thereto, The medical elongate body is a balloon catheter having an expandable and contractable balloon, or a stent delivery catheter having a stent mounted on the balloon, The medical instrument set, wherein the treatment portion is a straight portion of the balloon that has a substantially linear cross-sectional shape when the balloon is expanded, or the stent in an unexpanded state.

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