Medical device

Abstract

To provide a medical device capable of making friction with blood vessel walls small while suppressing flexibility deterioration of a shaft.SOLUTION: A medical device 10 has a long shaft 70. In the medical device 10, the shaft 70 has a metallic distal end tube 73, the distal end tube 73 includes a tip side rough surface part 73a having an uneven shape provided on the outside surface of the tip part, a base end rough surface part 73b having an uneven shape provided on the outside surface of the base end part, and an intermediate part 73c being a region between the tip side rough surface part 73a and the base end rough surface part 73b with a smooth outside surface, in the distal end tube 73, the outside surface is covered with a resin covering material 74, and the covering material 74 is brought into close contact with the tip side rough surface part 73a and the base end side rough surface part 73b.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to medical devices having elongate shafts. [Background technology]

[0002] One method for treating lesions such as stenosis and blockage in blood vessels is intravascular treatment, which uses a device percutaneously inserted into the blood vessel to perform treatment from within the blood vessel. In intravascular treatment, a catheter is used to deliver a treatment site to the lesion.

[0003] For example, a catheter for cutting and removing stenosis such as thrombus, plaque, and calcified lesions in blood vessels may use a metal tube for the long shaft. Because blood vessels are curved, the shaft comes into sliding contact with the blood vessel wall when it is inserted toward the lesion. If the friction between the blood vessel wall and the shaft is large, torque accumulates in the shaft as it is inserted into the blood vessel.

[0004] For example, Patent Document 1 describes a catheter having a metal tube, in which a resin coating material is provided on the surface of the metal tube. Since the coating material has a lower friction coefficient than metal, it is possible to reduce friction with the blood vessel wall when the catheter is inserted into a blood vessel, and to suppress accumulation of torque in the shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 8,628,549 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since a resin coating is provided on the surface of the tip of the tube and this is in close contact with the surface of the metal tube, the flexibility of the shaft as a whole decreases, and its passability through blood vessels decreases.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a medical device that can reduce friction with the blood vessel wall while suppressing a decrease in shaft flexibility. [Means for solving the problem]

[0008] A medical device that achieves the above-mentioned objective is a medical device having a long shaft, the shaft having a metal tip tube, the tip tube comprising a tip rough surface portion having an uneven shape provided on the outer surface of the tip, a base rough surface portion having an uneven shape provided on the outer surface of the base, and an intermediate portion having a smooth outer surface which is an area between the tip rough surface portion and the base rough surface portion, the outer surface of the tip tube being covered with a resin coating material which is in close contact with the tip rough surface portion and the base rough surface portion. Effect of the Invention

[0009] In the medical device constructed as described above, the covering material penetrates into the uneven shape of the distal tube at the distal rough surface portion and the proximal rough surface portion, respectively, and is fixed in close contact with the distal tube, so that the fixing strength of the covering material to the distal tube, which reduces friction with the blood vessel wall, can be increased. In addition, since the outer surface of the intermediate portion of the distal tube of the medical device is smooth, the covering material does not penetrate into the uneven shape, and a decrease in flexibility can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing a medical device according to an embodiment. [Diagram 2] 1 is a perspective view showing the tip portion of a medical device with the cutting portion and the containing portion visible. FIG. [Diagram 3] FIG. 2 is a cross-sectional view showing the tip of a medical device. [Figure 4] 4 shows the distal end of a medical device, where (a) is a cross-sectional view taken along line AA in FIG. 3, (b) is a cross-sectional view taken along line BB in FIG. 3, and (c) is a cross-sectional view taken along line CC in FIG. [Diagram 5] FIG. 4 is a cross-sectional view showing a portion of the medical device closer to the base end than FIG. 3, with the drive shaft shown in front view. [Figure 6] FIG. [Figure 7] 13 is a cross-sectional view showing the proximal rough surface portion of the distal tube and the covering material in close contact with each other. FIG. [Figure 8] 13 is a cross-sectional view showing the distal rough surface portion of the distal tube and the covering material in close contact with each other. FIG. [Figure 9] FIG. 13 is a cross-sectional view of the distal tube with the covering fixed to the middle portion thereof. [Figure 10] FIG. 13 is a schematic diagram showing a state in which cutting is being performed by the medical device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In addition, in this specification and the drawings, components having substantially the same functions are given the same reference numerals to avoid duplicated explanation. In this specification, the side inserted into a lumen is referred to as the "distal side" and the side operated is referred to as the "base side".

[0012] The medical device 10 according to the embodiment is inserted into a blood vessel and used in a procedure for cutting and removing plaque, calcified lesions, and the like, in acute lower limb ischemia and deep vein thrombosis. The object to be cut is not particularly limited, and may be, for example, an atheroma, a thrombus, and the like. Furthermore, all objects that may exist in a biological lumen may be objects to be cut by the medical device 10.

[0013] 1 to 3, the medical device 10 includes a rotatable rotating structure 11, a housing 12 that rotatably houses the rotating structure 11, and a handle 90 that is operated by an operator. The rotating structure 11 includes a drive shaft 20 that transmits a rotational force, an axle 30 that is rotatably supported by the housing 12, a cutting section 50 that cuts plaque or calcified lesions, and a protective tube 60 that is housed in the drive shaft 20. The housing 12 includes an outer tube shaft 70 that houses the drive shaft 20, and a bearing 80 that rotatably supports the axle 30.

[0014] The drive shaft 20 is a long tube. The drive shaft 20 is flexible and has a characteristic that a rotational force acting from the base end side can be transmitted to the tip end side. A shaft portion 30 is fixed to the tip end of the drive shaft 20. As shown in FIG. 5, the drive shaft 20 is a tube in which a plurality of wires 21 are arranged and connected in a spiral shape around the axis X of the rotating structure 11. The drive shaft 20 has an additional coil 23 wound in a spiral shape on the outer circumferential surface from a position on the base end side of the tip toward the base end side. The additional coil 23 can generate a flow of fluid that conveys an object toward the base end side as the drive shaft 20 rotates. The axis X is the structural center axis of the rotating structure 11 and is also the central axis of the rotating structure 11. The base end of the drive shaft 20 is located inside the handle portion 90. The drive shaft 20 does not have to be made of wire.

[0015] The material of the drive shaft 20 is not particularly limited as long as it is a metal, but for example, stainless steel, nitinol, etc. can be suitably used.

[0016] As shown in Figs. 1 to 3, the cutting unit 50 is a member for cutting and reducing the size of objects such as plaque and calcified lesions. Therefore, "cutting" means applying a force to a contacting object to reduce the size of the object. The method of applying the force in cutting and the shape and form of the object after cutting are not limited.

[0017] The cutting part 50 has a large number of minute abrasive grains on the surface. Alternatively, the cutting part 50 may have a sharp blade. The cutting part 50 has a first through hole 51 located on the tip side and a second through hole 52 located on the base end side of the first through hole 51. The first through hole 51 and the second through hole 52 communicate with each other and penetrate the cutting part 50 in the direction along the axis X. The tip part of the shaft part 30 is fitted and connected inside the second through hole 52.

[0018] The outer peripheral surface of the cutting part 50 has groove-shaped notches 53 extending in a direction along the axis X. The notches 53 function as flow paths for transporting the cut object toward the base end. The notches 53 are arranged, for example, every 120 degrees in the circumferential direction. Thus, the cutting part 50 has three notches 53 evenly arranged in the circumferential direction. The edges of each of the notches 53 are smoothly formed with a curvature. The number of the notches 53 is not limited to three.

[0019] The constituent material of the cutting portion 50 is preferably strong enough to cut plaque, calcified lesions, etc., and suitable materials for use include stainless steel, nitinol, Ta, Ti, Pt, Au, W, brass, shape memory alloys, super steel alloys, etc. When cutting soft objects such as thrombi, suitable materials for use include fluorine-based polymers such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-ethylene copolymer (ETFE), polyolefins such as polyether ether ketone (PEEK), polyimide, polyethylene, and polypropylene, and polyesters such as polyamide and polyethylene terephthalate.

[0020] The protective tube 60 is a flexible tube disposed inside the drive shaft 20 and the cutting section 50. The protective tube 60 is not fixed to the drive shaft 20 and the cutting section 50, and is disposed so as not to rotate together with the drive shaft 20. The protective tube 60 is formed with a guide wire lumen 61 through which a guide wire passes. The protective tube 60 prevents the guide wire passing through the inside of the drive shaft 20 from directly contacting and rubbing against the drive shaft 20. A cylindrical protective tube stopper 62 is connected to the tip of the protective tube 60. The base end of the protective tube stopper 62 has an outer diameter larger than that of the protective tube 60, and covers the tip of the protective tube 60. The tip of the protective tube stopper 62 has an outer diameter smaller than that of the base end of the protective tube stopper 62, and protrudes further toward the tip side than the protective tube 60. The base end of the protective tube stopper 62 is disposed in the gap between the shaft section 30 and the cutting section 50 in the axial direction. Therefore, the protective tube stopper 62 limits the movement of the protective tube 60 in the axial direction, and prevents the protective tube 60 from falling off.

[0021] 2 to 4, the bearing 80 has a first bearing 81 and a second bearing 82, each of which is ring-shaped. The first bearing 81 and the second bearing 82 are disposed apart from each other along the axis X inside the support tube 72. The first bearing 81 and the second bearing 82 have the same shape, but may have different shapes.

[0022] As shown in Figs. 2 to 4, the shaft portion 30 is a portion that supports the rotating structure 11 rotatably relative to the accommodation portion 12. The shaft portion 30 includes a base end connecting portion 31 that is connected to the drive shaft 20, and a tip connecting portion 32 that is connected to the cutting portion 50. The shaft portion 30 further includes a first sliding portion 33 that is supported by a first bearing 81, a second sliding portion 34 that is supported by a second bearing 82, and an intermediate shaft portion 35 that is disposed between the first sliding portion 33 and the second sliding portion 34. The shaft portion 30 has at least one passage 40 (three in this embodiment) that extends along the axis X formed therein.

[0023] The base end connecting part 31 is disposed at the base end of the shaft part 30, and the tip end of the drive shaft 20 can be fitted thereto and fixed by means of laser welding or the like. The tip connecting part 32 is disposed at the tip end of the shaft part 30, and the cutting part 50 can be fitted thereto and fixed.

[0024] The first sliding portion 33 is disposed on the base end side of the tip connecting portion 32 and is rotatably supported by the first bearing 81. The first sliding portion 33 has three groove-like passages 40 extending in the axial direction formed on the outer peripheral surface of a circular tube having a uniform outer diameter. The first sliding portion 33 has three first rotational contact portions 41 that contact the inner peripheral surface of the first bearing 81 between the three groove-like passages 40 that are evenly arranged in the circumferential direction. The outer diameter of the first rotational contact portions 41 is slightly smaller than the inner diameter of the first bearing 81. Therefore, the first rotational contact portions 41 slidably contact the inner peripheral surface of the first bearing 81.

[0025] The second sliding portion 34 is disposed on the tip side of the base end connecting portion 31 and is rotatably supported by the second bearing 82. The second sliding portion 34 has three groove-like passages 40 extending in the axial direction formed on the outer circumferential surface of a circular tube having a uniform outer diameter. The second sliding portion 34 has three second rotational contact portions 42 that contact the inner circumferential surface of the second bearing 82 between the three groove-like passages 40 that are evenly arranged in the circumferential direction. The outer diameter of the second rotational contact portions 42 is slightly smaller than the inner diameter of the second bearing 82. Therefore, the second rotational contact portions 42 slidably contact the inner circumferential surface of the second bearing 82.

[0026] The intermediate shaft portion 35 is disposed between the first sliding portion 33 and the second sliding portion 34. The intermediate shaft portion 35 has three groove-like passages 40 extending along the axis X formed on the outer peripheral surface of a circular tube having a uniform outer diameter. The intermediate shaft portion 35 has three protruding portions 43 that protrude radially outward beyond the first sliding portion 33 and the second sliding portion 34 between the three groove-like passages 40 that are evenly disposed in the circumferential direction.

[0027] The passage 40 forms a flow path that takes in the object cut by the cutting unit 50. The tip of each passage 40 communicates with the base end of the notch 53. The passage 40 is formed from the tip side to the base side of the bearing 80. The groove-shaped passage 40 may partially penetrate to the inner peripheral surface of the shaft unit 30. The passage 40 is connected to the outer peripheral surface of the shaft unit 30 on the tip side of the bearing 80. As a result, the space of the passage 40 communicates with the space outside the shaft unit 30 on the tip side of the bearing 80. Furthermore, the passage 40 is connected to the outer peripheral surface of the shaft unit 30 on the base side of the bearing 80. As a result, the space of the passage 40 communicates with the space outside the shaft unit 30 on the base side of the bearing 80. Therefore, the passage 40 can take in the cut object from the outside of the shaft unit 30 on the tip side of the bearing 80. And, the passage 40 can release the object taken in on the tip side of the bearing 80 to the outside of the shank 30 on the base side of the bearing 80. Also, by providing the passage 40 in the shank 30, the intake opening 111 for taking in the cutting chips can be positioned near the cutting portion 50. Furthermore, by providing the passage 40 in the shank 30, friction between the shank 30 and the bearing 80 can be reduced, and the sliding property can be improved.

[0028] As shown in Figs. 1 to 3, the outer tube shaft 70 is a tube that houses the drive shaft 20 and the protective tube 60. The outer tube shaft 70 has an outer tube main body 71 and a support tube 72 fixed to the tip side of the outer tube main body 71. Between the outer tube shaft 70 and the drive shaft 20, an intake lumen 110 is formed for taking in objects that have been cut and reduced in size, such as plaque and calcified lesions. The outer tube shaft 70 has an intake opening 111 at its tip for taking in the cut object and the liquid discharged from the drive shaft 20. The tip of the outer tube shaft 70 is disposed on the base end side from the base end of the cutting section 50 with a predetermined gap G therebetween. The gap G has a length exceeding 0 along the axis X when the rotating structure section 11 is disposed at the most base end side with respect to the housing section 12. Therefore, the tip of the outer tube shaft 70 is prevented from contacting the cutting section 50. The outer tubular shaft 70 has a proximal end opening 112 that opens inside the handle portion 90 at its proximal end.

[0029] The outer tube body 71 is a flexible tube. The outer tube body 71 extends from the handle portion 90 to the vicinity of the cutting portion 50. The outer tube body 71 has a curved portion 78 at the tip portion where the direction in which the outer tube body 71 extends changes. The curved portion 78 has a first curved portion 78a at the tip side and a second curved portion 78b at the base end side that curve in opposite directions, and has an S-shape. The curved portion 78 is not limited to being curved twice, and may be curved once or three or more times. The base end of the outer tube body 71 is fixed to the handle portion 90. The base end opening 112 is disposed at the base end of the outer tube body 71.

[0030] The support tube 72 is a metal circular tube fixed to the tip of the outer tube body 71. The support tube 72 includes a support tube body 113 having a certain inner diameter, and a stopper 114 arranged on the tip side of the support tube body 113 and having an inner diameter smaller than that of the support tube body 113. The intake opening 111 is arranged at the tip of the support tube 72. The stopper 114 comes into contact with the tip surface of a first bearing 81 of a bearing 80 described later. This allows the stopper 114 to restrict the first bearing 81 from moving toward the tip side relative to the support tube 72 and falling off the support tube 72. Note that the stopper 114 may be somewhat separated from the first bearing 81 as long as it can come into contact with the tip surface of the first bearing 81, since it can restrict the movement of the first bearing 81. It is preferable that the inner diameter of the stopper 114 is smaller than the outer diameter of the first bearing 81 and larger than the inner diameter. The structure of the stopper 114 is not particularly limited as long as it can limit the movement of the first bearing 81, and may be arranged partially in the circumferential direction, for example.

[0031] 5, the outer tube main body 71 has a metal distal tube 73 and a proximal tube 75 disposed on the proximal side of the distal tube 73. A curved portion 78 of the outer tube shaft 70 is formed within the range of the distal tube 73. The proximal tube 75 has a resin inner tube 75a having a braided body formed of thin metal wires therein, and a metal outer tube 75b covering the outer surface of the inner tube 75a.

[0032] The distal end tube 73 has a step 73d at its proximal end. The distal end of the inner tube 75a of the proximal tube 75 abuts against the step 73d of the distal end tube 73. The proximal end surface of the distal end tube 73 and the distal end surface of the outer tube 75b are butted together, and the proximal end of the distal end tube 73 and the outer surface of the distal end of the outer tube 75b are connected by a metal connecting member 77.

[0033] The outer surface of distal tube 73, in the region from the base end of support tube 72 to the tip of connecting member 77, is covered with a resin covering material 74. The outer surface of outer tube 75b constituting proximal tube 75 is covered with a proximal side covering material 76. The tip position of proximal side covering material 76 is located on the proximal side of the base end of connecting member 77.

[0034] As shown in FIG. 6, the distal tube 73 has a distal rough surface portion 73a having an uneven shape provided on the outer surface of the distal end, and a proximal rough surface portion 73b having an uneven shape provided on the outer surface of the proximal end. The distal tube 73 has an intermediate portion 73c between the distal rough surface portion 73a and the proximal rough surface portion 73b. The intermediate portion 73c has a number of circumferential slits 73f to increase flexibility, and between the slits 73f, there is a smooth portion 73g having a smooth outer surface. The distal rough surface portion 73a and the proximal rough surface portion 73b can be formed by roughening the outer surface of the distal tube 73. The roughening can be performed, for example, by irradiating the surface with a laser welder while shifting the focus with the irradiation energy of the laser welder being weakened. The roughening can also be performed by applying sandpaper or dimple processing.

[0035] 5, in the longitudinal direction of distal tube 73, distal rough surface portion 73a is formed in region A, proximal rough surface portion 73b is formed in region B, and intermediate portion 73c is formed in region C. Covering material 74 is in close contact with distal tube 73 by entering into the irregularities of distal rough surface portion 73a and proximal rough surface portion 73b, and covering material 74 is fixed to distal tube 73 only by the outer surface of smooth portion 73g without entering slit 73f of intermediate portion 73c.

[0036] The distal rough surface portion 73a has a distal end located closer to the proximal end than the distal end of the distal tube 73, and does not have to be formed at the most distal end of the distal tube 73 that is covered by the support tube 72. The proximal rough surface portion 73b has a proximal end located at the same position as the proximal end of the distal tube 73, and is in contact with the inner surface of the connecting material 77. The connecting material 77 is joined to the distal tube 73 with an adhesive, and by forming the proximal rough surface portion 73b up to the position of the connecting material 77, adhesion can be increased.

[0037] When fixing the covering material 74 to the distal tube 73, first, the tubular covering material 74 is placed on the distal tube 73 and heated at a first temperature (for example, about 210°C) to shrink the covering material 74. At this time, the covering material 74 penetrates into the unevenness of the distal rough surface portion 73a and the proximal rough surface portion 73b having an uneven shape and adheres to them. As shown in FIG. 7, in the proximal rough surface portion 73b heated at the first temperature, the inner surface of the covering material 74 can be inserted into the recess 73e of the uneven shape of the proximal rough surface portion 73b. Furthermore, by heating the distal rough surface portion 73a at a second temperature (for example, about 230°C) higher than the first temperature, the surface portion of the covering material 74 can be melted and the covering material 74 can be melted and inserted further into the uneven shape of the distal rough surface portion 73a. The first temperature and the second temperature can be set arbitrarily according to the material of the covering material 74, etc. As a result, as shown in FIG. 8, the inner surface of the covering material 74 can be inserted deeper into the recess 73e of the uneven shape of the tip side rough surface portion 73a. Both the tip side rough surface portion 73a and the base side rough surface portion 73b may be heated at the second temperature. In this case, the inner surface of the covering material 74 can be inserted into the recess 73e of the base side rough surface portion 73b as well, as shown in FIG. 8. Therefore, the adhesion between the covering material 74 and the tip tube 73 can be increased at the tip side rough surface portion 73a and the base side rough surface portion 73b, and the adhesion between the covering material 74 and the tip tube 73 can be further increased at the tip side rough surface portion 73a heated at the second temperature. As shown in FIG. 9, in the intermediate portion 73c, the covering material 74 does not enter the slit 73f, and the smooth portion 73g of the smooth intermediate portion 73c and the inner surface of the covering material 74 are adjacent to each other and fixed. Because the covering material 74 and the distal tube 73 are in close contact with each other at the distal end and the proximal end, it is possible to prevent the covering material 74 from falling off even if it is subjected to an external force, such as when the covering material 74 slides against a blood vessel wall. On the other hand, because the covering material 74 does not enter the slits 73f of the intermediate part 73c of the distal tube 73 and is fixed only by the smooth part 73g of the intermediate part 73c, the adhesion of the intermediate part 73c to the covering material 74 does not become high, and a decrease in flexibility can also be prevented.In this way, the covering material 74 penetrates into the tip side rough surface portion 73a and the base side rough surface portion 73b on the outer surface of the tip tube 73, thereby adhering to the tip tube 73, and the covering material 74 is fixed only to the outer surface of the smooth portion 73g of the intermediate portion 73c, thereby adhering the covering material 74 to the tip and base ends of the tip tube 73 and suppressing a decrease in flexibility in other areas. This ensures flexibility at the tip of the outer tube shaft 70 while reducing friction of the tip tube 73 against the blood vessel wall.

[0038] It is desirable that the distal rough surface portion 73a and the proximal rough surface portion 73b of the distal tube 73 are disposed in a portion other than the first curved portion 78a and the second curved portion 78b in the longitudinal direction. For example, the distal rough surface portion 73a can be disposed on the distal side of the first curved portion 78a, and the proximal rough surface portion 73b can be disposed on the proximal side of the second curved portion 78b. In addition, one of the distal rough surface portion 73a and the proximal rough surface portion 73b can be disposed between the first curved portion 78a and the second curved portion 78b.

[0039] As described above, the distal tube 73 and the outer tube 75b of the proximal tube 75 are made of metal. The constituent material preferably has a certain degree of strength, and for example, stainless steel, nitinol, Ta, Ti, Pt, Au, W, shape memory alloys, etc. can be suitably used.

[0040] The coating material 74 is made of a resin that is flexible and has good slipperiness. It is also preferable that the coating material 74 melts at a certain temperature. In this embodiment, polyolefin is used as the coating material 74. However, the coating material 74 may be made of other resins having the above-mentioned characteristics, and for example, a thermoplastic resin such as polyamide or polyurethane may be appropriately combined with a hydrophilic coating or the like.

[0041] The base end covering material 76 can be made of a resin harder than the covering material 76 that covers the distal tube 73. As such a resin, for example, a nylon-based elastomer, for example, Pebax (registered trademark), can be used. This increases the rigidity of the outer tube shaft 70 and improves operability including torque transmission. However, the base end covering material 76 may be made of other resins, such as PTFE or PET.

[0042] The material constituting the support tube 72 preferably has a certain degree of strength, and suitable materials for use include, for example, stainless steel, nitinol, Ta, Ti, Pt, Au, W, shape memory alloys, engineering plastics such as polyether ether ketone (PEEK), and combinations thereof.

[0043] As shown in Fig. 5, the outer surface of the distal end of the drive shaft 20 is covered with a resin distal end covering part 25. The distal end covering part 25 extends continuously along the longitudinal direction from the proximal end surface of the shaft part 30 to the proximal side of the joint between the distal end tube 73 and the proximal end tube 75. The distal end covering part 25 extends in the longitudinal direction to include the range of the curved part 78 of the outer tube shaft 70. Since the outer tube shaft 70 has an S-shaped curved part 78, the drive shaft 20 is likely to come into contact with the first curved part 78a and the second curved part 78b, and at this time, the distal end covering part 25 comes into contact with the inner surface of the outer tube shaft 70, thereby reducing friction between the two. Furthermore, as described above, the inner tube 75a of the base end tube 75 has a metal braid inside, and the braid may be exposed on the inside at the tip. However, since the tip covering portion 25 is also provided at the joint between the tip tube 72 and the base end tube 75, the exposed braid can be prevented from coming into direct contact with the metal parts of the drive shaft 20, thereby improving the durability of the drive shaft 20.

[0044] As shown in FIG. 1, the handle portion 90 includes a casing 91, a drive portion 92, an intake port 93, a rotation operation portion 94, and a liquid delivery port 96.

[0045] The base end of the outer tube body 71 is fixed to the tip end of the casing 91. The casing 91 has an intake space 95 communicating with an intake port 93 and a liquid delivery space 96 communicating with a liquid delivery port 96 formed therein. A base end opening 112 of the outer tube body 71 is rotatably disposed in the intake space 95.

[0046] The rotation operation unit 94 is a part that is operated by the surgeon's fingers to apply a rotational torque to the outer tube shaft 70. The rotation operation unit 94 is rotatably connected to the tip end of the casing 91. The rotation operation unit 94 is fixed to the outer peripheral surface of the base end of the outer tube main body 71.

[0047] The driving unit 92 is, for example, a hollow motor. The driving unit 92 rotates by power supplied from a battery (not shown) or an external source. The drive shaft 20 is fixed to a hollow driving rotor of the hollow motor. The rotation speed of the driving unit 92 is not particularly limited, but is, for example, 5,000 to 200,000 rpm. The configuration of the driving unit 92 is not particularly limited.

[0048] The intake port 93 transports objects, liquids, etc., inside the intake space 95 to the outside. An intake drive source such as a pump or a syringe can also be connected to the intake port 93. A fluid can be sent from the liquid sending port 96 to the inside of the outer tube shaft 70 via the liquid sending space 97.

[0049] Next, a method of using the medical device 10 according to this embodiment will be described using an example in which a lesion such as plaque or a calcified lesion in a blood vessel is cut and taken in.

[0050] First, the surgeon inserts the guidewire W into the blood vessel and reaches the vicinity of the lesion S. Next, the surgeon inserts the base end of the guidewire W into the guidewire lumen 61 of the medical device 10. Thereafter, as shown in FIG. 10, the cutting section 50 is moved to the vicinity of the lesion S using the guidewire W as a guide. At this time, since the distal end tube 72 constituting the distal end of the outer tube shaft 70 is provided with a resin coating material 76, friction with the blood vessel wall can be kept low. Therefore, when the outer tube shaft 70 is inserted into a blood vessel path that is bent multiple times, accumulation of torque in the outer tube shaft 70 can be suppressed.

[0051] Next, the surgeon operates the drive unit 92. This rotates the drive shaft 20, and the cutting unit 50 and the shaft unit 30 rotate together with the drive shaft 20. This allows the surgeon to cut the lesion S with the cutting unit 50. At this time, the inner surface of the outer tube shaft 70 and the drive shaft 20 rotating at high speed may come into contact with each other, particularly at the curved portion 78. However, since the resin tip covering portion 25 is provided at the tip of the drive shaft 20, the friction between the drive shaft 20 and the outer tube shaft 70 can be kept low.

[0052] In addition, the surgeon can move the entire handle portion 90 or the outer tube shaft 70 exposed to the outside of the body to reciprocate the outer tube shaft 70 along the longitudinal direction of the blood vessel. This allows the surgeon to cut the lesion S along the longitudinal direction of the blood vessel with the cutting portion 50.

[0053] The additional coil 23 can generate a flow of fluid that transports objects in the intake lumen 110 toward the base end side as the drive shaft 20 rotates. Therefore, the lesion S cut by the cutting part 50 becomes debris and is taken into the intake lumen 110 from the tip opening. The debris can pass through the notch part 53 of the cutting part 50 and efficiently enter the passage 40 communicating with the notch part 53. In addition, the debris can enter the passage 40 from the gap G between the cutting part 50 and the support tube 72. The passage 40 may be formed in a spiral shape centered on the axis X. As a result, when the drive shaft 20 is rotated by the rotating passage 40, the rotating spiral passage 40 can function as an Archimedes screw (screw pump). As a result, the passage 40 can smoothly transport objects and fluids inside the intake lumen 110 to the base end side.

[0054] The debris that has entered the passage 40 distally of the first bearing 81 moves proximally inside the first bearing 81 and the second bearing 82. The debris then moves proximally from the passage 40 to the outer circumferential surface of the shaft portion 30 proximally of the second bearing 82. The debris then moves proximally through the intake lumen 110 and is discharged through the intake space 95 and the intake port 93. After the cutting of the lesion S and the intake of the debris are completed, the surgeon stops the operation of the drive unit 92. This stops the cutting of the lesion S and the discharge of the debris. The surgeon then removes the medical device 10 from the blood vessel to complete the procedure.

[0055] As described above, the medical device 10 according to the present embodiment (1) is a medical device 10 having a long shaft 70, the shaft 70 having a metal distal tube 73, the distal tube 73 having a roughened distal surface portion 73a having an uneven shape provided on the outer surface of the distal end, a roughened proximal surface portion 73b having an uneven shape provided on the outer surface of the proximal end, and a middle portion 73c having a smooth outer surface which is a region between the roughened distal surface portion 73a and the roughened proximal surface portion 73b, the outer surface of the distal tube 73 is covered with a resin coating material 74, and the coating material 74 is in close contact with the roughened distal surface portion 73a and the roughened proximal surface portion 73b. In the medical device 10 thus configured, the coating material 74 penetrates into the uneven shape of the distal tube 73 at the roughened distal surface portion 73a and the roughened proximal surface portion 73b, respectively, and is fixed in close contact with the distal tube 73, so that the fixing strength of the coating material 74 to the distal tube 73, which reduces friction with the blood vessel wall, can be increased. Furthermore, in the medical device 10, the outer surface of the intermediate portion 73c of the distal tube 73 is smooth, so that the covering material 74 does not get into the uneven shape, and a decrease in flexibility can be suppressed.

[0056] (2) In the medical device 10 described above in (1), the shaft 70 may have a curved portion 78 shaped in the region of the distal tube 73, and the curved portion 78 may be located in the intermediate portion 73c. ​​Since the intermediate portion 73c is not filled with the covering material 74 and is highly flexible, the medical device 10 can improve the passage of the shaft 70 through a blood vessel by making the curved portion 78 flexible.

[0057] (3) In the medical device 10 of (1) or (2) above, the distal rough surface portion 73a may have a distal position at the distal end of the covering material 74, and the proximal rough surface portion 73b may have a proximal position on the proximal side of the proximal end of the covering material 74. This allows the medical device 10 to increase the adhesion between the distal tube 73 and a member provided on the proximal side of the covering material 74, thereby increasing the bonding strength of the distal tube 73.

[0058] (4) In any of medical devices 10 described above in (1) to (3), at least one of distal rough surface portion 73a and proximal rough surface portion 73b may have uneven recesses 73e into which covering material 74 fits. This improves the adhesion between distal tube 73 and covering material 74 in medical device 10, and prevents covering material 74 from falling off distal tube 73.

[0059] (5) In any of medical devices 10 described above in (1) to (4), intermediate portion 73c may have slit 73f and smooth portion 73g having a smooth outer surface, and smooth portion 73g may be fixed to covering material 74. Since covering material 74 is fixed to smooth portion 73g and does not enter slit 73f, the fixing strength of covering material 74 can be increased while preventing a decrease in flexibility of distal end tube 73.

[0060] (6) In any of the medical devices 10 described above in (1) to (3), the distal rough surface portion 73a and the proximal rough surface portion 73b may have the covering material 74 infiltrating into the unevenly shaped recesses 73e, and the covering material 74 may infiltrate deeper into the recesses 73e of the distal rough surface portion 73a than into the proximal rough surface portion 73b. This can increase the degree of adhesion of the covering material 74 to the distal end side of the distal tube 73, thereby increasing the fixing strength.

[0061] (7) In any of the medical devices 10 described above in (1) to (6), the shaft 70 has a metal proximal tube 75 on the proximal side of the distal tube 73, and the outer surface of the proximal tube 75 is covered with a resin proximal side covering material 76, and the covering material 74 may be softer than the proximal side covering material 76. This allows the medical device 10 to ensure the rigidity of the proximal end of the shaft 70 to increase torque transmission and pushability, while increasing the flexibility of the distal end of the shaft 70.

[0062] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. The medical device 10 is not limited to devices that cut and remove objects in blood vessels, and the present invention can be applied to other types of devices that have a metal tube at the tip, such as an ultrasonic catheter. [Explanation of symbols]

[0063] 10 Medical Devices 20 Drive shaft 21 Wire rod 23 Additional coil 25 Tip coating 30 Shaft Aisle 40 50 Cutting part 60 Protection tube 70 Outer tube shaft 71 Outer tube body 73 Tip tube 73a Tip side rough surface 73b Proximal rough surface 73c middle part 74 Covering material 75 Base end tube 76 Proximal covering material 77 Connecting material 78 Curved Section 78a First curved section 78b Second curved section 80 Bearings 90 Handle 91 Casing 92 Drive unit 110 Lumens Intake 111 Intake opening 112 Proximal opening

Claims

1. 1. A medical device having an elongate shaft, The shaft has a metal tip tube; The tip tube has a tip portion and a base portion, and is provided with a tip side rough surface portion having an uneven shape provided on the outer surface of the tip portion, a base side rough surface portion having an uneven shape provided on the outer surface of the base portion, and an intermediate portion having a smooth outer surface that is a region between the tip side rough surface portion and the base side rough surface portion, The outer surface of the tip tube is covered with a resin coating material. The medical device wherein the covering material is in intimate contact with the distal rough surface portion and the proximal rough surface portion.

2. The medical device of claim 1 , wherein the shaft has a curved portion at the intermediate portion of the tip tube.

3. the distal rough surface portion has a distal position at a distal end of the covering material, The medical device of claim 1 or 2, wherein the proximal rough surface portion has a proximal position proximal to a proximal end of the covering material.

4. The medical device according to claim 1 or 2, wherein the coating material fills recesses in an uneven shape in at least one of the distal rough surface portion and the proximal rough surface portion.

5. The medical device according to claim 4 , wherein the intermediate portion has a slit and a smooth portion having a smooth outer surface, and the smooth portion and the covering material are fixed to each other.

6. The distal rough surface portion and the proximal rough surface portion have recesses of an uneven shape in which the coating material is inserted, The medical device of claim 1 or 2, wherein the coating material penetrates deeper into the recess at the distal rough surface portion than at the proximal rough surface portion.

7. The shaft has a metal base end tube on a base end side of the tip tube, The outer surface of the proximal tube is covered with a proximal side coating material made of resin.

3. The medical device of claim 1 or 2, wherein the covering is softer than the proximal covering.

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