Medical device

Abstract

Provided is a medical device capable of smoothly removing a hollow lead implanted in a body.　A medical device 1 comprises: a long body 11; and an expansion member 31 which covers an outer periphery of the body 11 and can be expanded outward in a radial direction. The expansion member 31 is a coil 31 in which a wire w1 is wound around the outer periphery of the body 11. The maximum width of the wire w1 in a first portion 31A of the coil 31 is smaller than the maximum width of the wire w1 in a second portion 31B of the coil 31, the second portion 31B being located closer to the base end side than the first portion 31A.

Description

medical devices

[0001] The present disclosure relates to medical devices.

[0002] 2. Description of the Related Art When hollow leads extending from a pacemaker or an implantable cardioverter defibrillator (ICD) implanted in the heart are removed from the body, for example, a medical device for removing the leads is used.

[0003] Known examples of such medical devices include a device in which a coil is provided around the outer periphery of a stylet wire (see, for example, Patent Document 1).

[0004] In the above-described medical device, the lead can be removed from the body by expanding the coil inside the lead lumen and then pulling out the medical device while fixing the outer periphery of the expanded coil to the lumen wall of the lead.

[0005] U.S. Pat. No. 4,943,289

[0006] The present specification discloses a medical device that allows for smooth removal of a hollow lead implanted in the body.

[0007] One aspect of the medical device disclosed herein includes: (1) an elongated main body; and an expansion member that covers the outer periphery of the main body and is expandable radially outward, wherein the expansion member is a coil in which strands of wire are wound around the outer periphery of the main body, and the maximum width of the strands of wire at a first portion of the coil is smaller than the maximum width of the strands of wire at a second portion of the coil that is located proximal to the first portion. With this configuration, the distal end of the expansion member begins to expand radially outward before the proximal end of the expansion member. As a result, for example, when removing a hollow lead from the body, the distal end of the expansion member can be fixed distal to the lead, allowing for smooth removal of the hollow lead implanted in the body.

[0008] (2) In the medical device of (1), the maximum width of the wire may gradually increase from the distal end toward the proximal end of the coil. With this configuration, the expansion member can be gradually expanded from the distal end toward the proximal end.

[0009] (3) In the medical device of (1) or (2), the pitch of the wires in the first region may be larger than the pitch of the wires in the second region, and with this configuration, the maximum width of the expansion member in the first region when expanded can be larger than the maximum width of the expansion member in the second region.

[0010] (4) In the medical device according to any one of (1) to (3), the coil may have a third section located closer to the proximal end than the second section, and at least some of the adjacent wires may be fixed to each other in the third section. With this configuration, the stiffness of the coil in the third section can be made higher than the stiffness of the first and second sections.

[0011] (5) In the medical device according to any one of (1) to (4), the pitch of the wires may be gradually reduced from the distal end to the proximal end of the coil. With this configuration, the maximum width of the coil when the expansion member is expanded can be gradually increased from the proximal end to the distal end of the coil.

[0012] (6) In the medical device according to any one of (1) to (5), the coil may have a fourth section located distally of the first section, and the fourth section may be fixed to the main body by a solder material containing gold. With this configuration, the gold contained in the solder material of the fourth section functions as a radiopaque material, making it easy to identify the fourth section under X-ray fluoroscopy.

[0013] (7) In the medical device according to any one of (1) to (6), a radiopaque marker may be provided on the distal side of the first portion. With this configuration, the position of the distal end of the first portion can be easily grasped under X-ray fluoroscopy.

[0014] (8) The medical device according to any one of (1) to (7) may further include a pushing member movable along the longitudinal direction of the main body and pushing the base end of the expansion member toward the distal end, the pushing member being a tubular body that covers the outer periphery of the main body, and the maximum width of the pushing member decreasing toward the distal end. According to this configuration, by moving the pushing member toward the distal end, the expansion member can be compressed with a simple configuration, and the expansion member can be reliably expanded. According to this configuration, the rigidity of the pushing member decreases toward the distal end, allowing it to easily pass through curved blood vessels.

[0015] (9) In the medical device of (8), the maximum width of the tip of the pushing member may be smaller than the maximum width of the base end of the expansion member. This configuration, for example, reduces the risk of the tip of the pushing member getting caught in the lumen of the lead, making it easier to insert the medical device into the lead.

[0016] One aspect of the medical device of the present disclosure is (10) a medical device comprising: an elongated body; and an expansion member covering the outer periphery of the body and expandable radially outward, wherein a distal end of the expansion member begins to expand radially outward before a proximal end of the expansion member. With this configuration, for example, when removing a hollow lead from the body, the distal end of the expansion member can be fixed distal to the lead, allowing the hollow lead implanted in the body to be smoothly removed.

[0017] (11) In the medical device of (10), when the expansion member is in an expanded state, the maximum width of the distal end of the expansion member may be greater than the maximum width of the proximal end of the expansion member. With this configuration, the distal end of the expansion member can be reliably fixed to the distal end of the lead.

[0018] (12) In the medical device of (10) or (11), the expansion force of the distal end of the expansion member may be greater than the expansion force of the proximal end of the expansion member. With this configuration, the distal end of the expansion member can be reliably fixed to the distal end of the lead.

[0019] (13) In the medical device according to any one of (10) to (12), the stress generated at the distal end of the expansion member (31) due to longitudinal compression of the expansion member (31) may be greater than the stress generated at the proximal end of the expansion member (31) due to longitudinal compression of the expansion member (31). With this configuration, the distal end of the expansion member can be reliably fixed distally to the lead.

[0020] (14) In the medical device according to any one of (10) to (13), a pushing member may be provided that is movable along the longitudinal direction of the main body and pushes the base end of the expansion member toward the distal end. With this configuration, by moving the pushing member toward the distal end, the expansion member can be compressed with a simple configuration and the expansion member can be reliably expanded.

[0021] (15) In the medical device according to any one of (10) to (14), the expansion member may be a coil in which a wire is wound around the outer periphery of the main body. This configuration makes it possible to easily form the expansion member.

[0022] (16) In the medical device of (15), the pitch of the wires at the distal end of the coil may be larger than the pitch of the wires at the proximal end of the coil. With this configuration, the maximum width of the distal end of the coil when the expansion member is expanded can be larger than the maximum width of the proximal end of the coil.

[0023] (17) In the medical device of (15) or (16), the maximum width of the wires at the distal end of the coil may be smaller than the maximum width of the wires at the proximal end of the coil. With this configuration, the distal end of the coil begins to expand radially outward before the proximal end of the coil.

[0024] (18) In the medical device according to any one of (10) to (17), the device may be used to remove a hollow lead from the body, and the expansion member may be inserted into the lumen of the lead and expand radially outward to be fixed to the lead. With this configuration, the expansion member can be fixed to the lead, and the lead can be removed from the body.

[0025] (19) In the medical device of (18), the lead may have a first electrode located at the distal end of the lead and a second electrode located proximal to the first electrode, and when the expansion member is in an expanded state, the outer periphery of the expansion member may be configured to abut against an inner periphery of the lead distal to the second electrode. With this configuration, the lead and the medical device can be fixed at a position closer to the distal end of the lead.

[0026] (20) In the medical device according to any one of (10) to (19), the distal end of the expansion member may be located within 10 mm of the distal end of the main body in the longitudinal direction of the main body toward the proximal end. With this configuration, the distal end of the expansion member is located near the distal end of the main body, allowing the expansion member to be expanded at the distal end of the medical device.

[0027] (21) In the medical device according to (1) to (9) and (15) to (17), the distal end of the coil may have an outer diameter smaller than the proximal end of the coil. This configuration allows the medical device to be smoothly advanced through the lumen of the lead.

[0028] (22) In the medical device according to (1) to (9) and (15) to (17), the wire may have an X-ray opaque portion. With this configuration, the position of the expansion member can be easily grasped under X-ray fluoroscopy.

[0029] (23) In the medical device according to any one of (1) to (22), a reinforcing member may be provided between the outer periphery of the main body and the inner periphery of the expansion member, extending along the longitudinal direction of the main body. With this configuration, by filling the gap between the main body and the expansion member, it is possible to suppress deformation of the expansion member toward the radially inward direction. As a result, it is possible to suppress twisting of the expansion member in the circumferential direction, which causes asymmetric expansion of the expansion member.

[0030] (24) In the medical device of (23), the reinforcing body may be an inner coil wound with a wire. With this configuration, the reinforcing body can be easily formed.

[0031] (25) In the medical device of (23), the reinforcing body may be a braided body with wires woven in. With this configuration, the main body can be reinforced while maintaining flexibility.

[0032] (26) In the medical device of (23), the reinforcing body may be a resin tube. With this configuration, the gap between the main body and the expansion member can be continuously filled.

[0033] (27) In the medical device according to any one of (1) to (26), the main body may be formed of a core shaft, the core shaft may have a distal core shaft and a proximal core shaft joined to a proximal end of the distal core shaft and extending toward the proximal end, and the flexural rigidity of the proximal core shaft may be greater than that of the distal core shaft. With this configuration, the medical device can be pushed forward so that the distal end of the medical device can easily follow the lumen of the lead that curves inside the body while maintaining pushability of the medical device.

[0034] (28) In the medical device of (27), the distal core shaft may be formed of a Ni-Ti alloy, and the proximal core shaft may be formed of a stainless steel alloy. With this configuration, the medical device can be pushed forward so that the distal end of the medical device can easily follow the curved lumen of the lead inside the body while maintaining the pushability of the medical device.

[0035] (29) The medical device of (27) or (28) further includes a pushing member movable along the longitudinal direction of the main body and pushing the base end of the expansion member toward the distal end, the pushing member being a tubular body that covers the outer periphery of the main body, and the joint between the distal core shaft and the proximal core shaft may be covered by the tubular body. With this configuration, when the medical device is bent, concentration of bending stress at the joint can be suppressed, and as a result, bending of the core shaft at the joint can be suppressed.

[0036] One aspect of the medical device of the present disclosure (30) comprises: an elongated main body; and an expansion member covering the outer periphery of the main body and expandable radially outward, the expansion member having an expansion portion expandable radially outward and a non-expandable portion located distally of the expansion portion and not expandable radially outward, wherein the distal end and the proximal end of the non-expandable portion are fixed to the main body at joints, and a portion of the non-expandable portion between the distal end and the proximal end of the non-expandable portion is a non-joint portion that is not fixed to the main body. With this configuration, the non-expandable portion has a non-joint portion, which can improve the flexibility of the non-expandable portion.

[0037] (31) In the medical device of (30), the bending stiffness of the non-bonded portion may be smaller than the bending stiffness of any of the bonded portions. With this configuration, for example, when the medical device is inserted into a portion of the lead that is highly curved, the non-bonded portion bends along the curve of the lead, thereby improving the ease of passage of the medical device.

[0038] (32) In the medical device of (30) or (31), the expansion member may be a coil in which a wire is wound around the outer periphery of the main body. With this configuration, the expansion member can be easily formed.

[0039] (33) In the medical device according to any one of (30) to (32), the X-ray transmittance of the non-expandable portion may be smaller than the X-ray transmittance of the expandable portion. With this configuration, the position of the non-expandable portion of the expandable member can be easily determined under X-ray fluoroscopy.

[0040] One aspect of the medical device of the present disclosure (34) comprises: an elongated main body; an expansion member covering the outer periphery of the main body and expandable radially outward; and a pushing member movable along the longitudinal direction of the main body and pushing a proximal end of the expansion member toward a distal end, wherein the proximal end of the pushing member has a greater rigidity than the distal end of the pushing member. This configuration improves the pushability of the pushing member and ensures reliable transmission of a pushing force from the proximal end of the pushing member toward the distal end.

[0041] (35) In the medical device of (34), the pushing member may have a reinforcing coil covering the outer periphery of the base end of the pushing member. With this configuration, the rigidity of the base end of the pushing member can be increased.

[0042] (36) In the medical device of (35), a pushing loop member may be provided at the proximal end of the pushing member. With this configuration, the pushing member can be easily pushed toward the distal end using forceps, tweezers, or the like.

[0043] (37) In the medical device of (36), the maximum width of the push-in loop member may be smaller than the maximum width of the reinforcing coil. With this configuration, for example, interference between the push-in loop member and the lead can be reduced, and the medical device can be easily inserted into the lead.

[0044] (38) In the medical devices of (36) and (37), the length of the loop portion of the push-in loop member in the longitudinal direction of the main body may be greater than the maximum width of the reinforcing coil. With this configuration, the opening of the loop portion becomes larger, making it easier to insert forceps, tweezers, etc. into the loop portion, thereby improving the operability of the medical device.

[0045] (39) In the medical device according to any one of (36) to (38), the tip of the pushing loop member may be located radially inside an imaginary cylindrical surface formed by extending the outer circumferential surface of the reinforcing coil. With this configuration, when the medical device is pushed into the lead, the tip of the pushing loop member can be prevented from getting caught on the lumen wall of the lead, thereby preventing the advancement of the medical device from being hindered.

[0046] (40) In the medical device of (36), the proximal end of the pushing loop member may be fixed between an outer periphery of the proximal end of the pushing member and an inner periphery of the reinforcing coil, thereby improving the bonding strength between the pushing loop member and the pushing member.

[0047] (41) In the medical device of (40), the proximal end of the pushing loop member may have a first end and a second end, and the first end and the second end may be spaced apart from each other. With this configuration, the loop portion is enlarged, making it easy to insert forceps, tweezers, or the like into the loop portion, thereby improving the operability of the medical device.

[0048] One aspect of the medical device of the present disclosure (42) comprises: an elongated main body, an expansion member covering the outer periphery of the main body and expandable radially outward, a pushing member movable along the longitudinal direction of the main body and pushing the base end of the expansion member toward the distal end, and a fixing mechanism capable of fixing the main body and the pushing member. With this configuration, the main body and the pushing member can be fixed, and the expansion of the expansion member can be suppressed when the medical device is not in use.

[0049] (43) In the medical device of (42), the pushing member may be a tubular body covering an outer periphery of the main body, and the fixing mechanism may fix the main body to the pushing member by engaging the outer periphery of the main body with the inner periphery of the pushing member. With this configuration, the main body and the pushing member can be fixed, and the expansion member can be prevented from expanding when the medical device is not in use.

[0050] (44) In the medical device of (43), the main body may be a core shaft, and the fixing mechanism may have a curved portion formed by curving a portion of the core shaft, the curved portion being adapted to abut against an inner periphery of the pushing member. With this configuration, the main body and the pushing member can be fixed together with a simple structure.

[0051] (45) In the medical device of (44), the fixing mechanism may have a first curved portion where the core shaft is curved in a first direction, and a second curved portion where the core shaft is curved in a second direction different from the first direction. With this configuration, the main body and the pushing member can be fixed with a simple configuration.

[0052] (46) In the medical device according to (45), the fixing mechanism may be configured such that the first curved portion and the second curved portion are arranged in a zigzag pattern. This configuration allows the main body and the pushing member to be fixed together with a simple configuration.

[0053] (47) In the medical device according to any one of (42) to (46), the main body may have a first marker at a location distal to the tip of the fixing mechanism. With this configuration, it is possible to easily determine whether the fixing mechanism is operating.

[0054] (48) In the medical device of (47), the main body may have a second marker at a position proximal to the proximal end of the fixing mechanism. With this configuration, it is possible to easily determine whether the fixing mechanism is operating.

[0055] (49) In the medical device of (48), the first marker and the second marker may each be a metal oxide coating formed on the surface of the body. This configuration makes it possible to easily form the first and second markers.

[0056] (50) In the medical device according to any one of (42) to (49), a position marker may be provided on the outer periphery of the base end of the pushing member. With this configuration, the positional relationship between the main body and the pushing member can be easily grasped, and the fixing mechanism can be smoothly operated.

[0057] (51) The medical device of (42) further includes a flexible gripping member disposed proximal to the pushing member and connected to the proximal end of the main body, and the fixing mechanism may be a resin fixing tube that covers the outer peripheries of the pushing member and the gripping member and fixes the pushing member and the gripping member. This configuration allows the fixing tube to be detachably fixed to the pushing member and the gripping member. As a result, when the medical device is not in use, it is possible to prevent the pushing member from accidentally moving distally, thereby preventing the expansion member from expanding.

[0058] (52) In the medical device of (51), the fixing tube may have a slit extending along the longitudinal direction of the main body. With this configuration, the cylindrical fixing tube can be easily removed from the pushing member and the gripping member by tearing and unfolding the fixing tube along the longitudinal direction starting from the slit.

[0059] (53) In the medical device of (42), the fixing mechanism may be formed by a screw mechanism provided on the pushing member and the main body and fixing the pushing member to the main body. With this configuration, the pushing member and the main body can be releasably fixed. As a result, when the medical device is not in use, it is possible to prevent the pushing member from accidentally moving toward the distal end and causing the expansion member to expand.

[0060] One aspect of the medical device of the present disclosure (54) comprises: an elongated main body; an expansion member covering the outer periphery of the main body and expandable radially outward; a pushing member movable along the longitudinal direction of the main body and pushing the base end of the expansion member toward the distal end; and a flexible gripping member disposed proximal to the pushing member and connected to the base end of the main body, the gripping member being formed by spirally winding a wire. With this configuration, the gripping member can be easily and reliably grasped. For example, by wrapping the gripping member around the hand, the operator can reliably pull the lead out of the body when removing the lead.

[0061] (55) In the medical device of (54), the length of the gripping member in the longitudinal direction may be greater than the length of the pushing member in the longitudinal direction. With this configuration, for example, the gripping member can be easily wrapped around a hand of a procedural operator.

[0062] (56) In the medical device of (54) or (55), the gripping member may be tubular, a gripping loop member may be provided at the base end of the gripping member, and a distal end of the gripping loop member may be fixed to the inner periphery of the base end of the tubular gripping member. With this configuration, for example, when using a sheath, the medical device can be easily pulled by hooking forceps or the like on the gripping loop.

[0063] (57) In the medical device of (56), the maximum width of the gripping loop member may be smaller than the maximum width of the gripping member. This configuration can reduce interference between the gripping loop member and a sheath or the like, improving the operability of the medical device, for example.

[0064] (58) In the medical device according to any one of (54) to (57), the wire forming the gripping member may include a core wire and a side wire wound around the core wire. This configuration makes the gripping member flexible and prevents it from becoming bent.

[0065] One aspect of the medical device of the present disclosure (59) comprises: an elongated main body; and an expansion member covering the outer periphery of the main body and expandable radially outward, the expansion member having an expansion section expandable radially outward and a non-expandable section provided distally of the expansion section and not expanding radially outward, wherein the main body is a core shaft, and the distal end of the core shaft has a first tapered section that gradually expands in diameter toward the base end, and the first tapered section is located distally of the tip of the expansion section. This configuration can increase the flexibility of the distal end of the medical device, thereby improving pushability and followability.

[0066] (60) In the medical device of (59), the outer periphery of the first tapered portion may be covered with the non-expandable portion. With this configuration, the rigidity of the main body where the non-expandable portion is located can be reduced toward the distal end, and the flexibility of the distal end of the medical device can be increased, thereby improving the pushability and followability.

[0067] (61) In the medical device of (59) and (60), the distal end of the non-expandable portion and the proximal end of the non-expandable portion may each be fixed to the main body at a joint, a portion of the non-expandable portion between the distal end of the non-expandable portion and the proximal end of the non-expandable portion may be a non-joint portion that is not fixed to the main body, and an outer periphery of the proximal end of the first tapered portion may be covered by the non-joint portion. This configuration can increase the flexibility of the distal end of the medical device, thereby improving pushability and followability.

[0068] (62) In the medical device according to any one of (59) to (61), the core shaft may have a first straight portion having a constant outer diameter extending from a proximal end of the first tapered portion toward the proximal end, and the outer periphery of the first straight portion may be covered with the expansion portion. With this configuration, the expansion portion can be expanded while maintaining the flexibility of the distal end of the medical device.

[0069] (63) The medical device of (62), further comprising a pushing member movable along the longitudinal direction of the main body and pushing the proximal end of the expansion member toward the distal end, wherein the core shaft has a second tapered portion located proximally of the first straight portion and gradually increasing in diameter toward the proximal end, and a second straight portion having a constant outer diameter and extending from the proximal end of the second tapered portion toward the proximal end, and the outer periphery of the second straight portion may be covered by the pushing member. This configuration can ensure the rigidity of the medical device proximal to the expansion member while increasing the flexibility of the distal end of the medical device. As a result, the passability of the distal end of the medical device can be improved.

[0070] One aspect of the medical device of the present disclosure (64) comprises: an elongated main body; and an expansion member covering the outer periphery of the main body and expandable radially outward, wherein at least a portion of the expansion member is plastically deformed when the expansion member is expanded. With this configuration, for example, even if the pushing member is retracted after the expansion member is expanded, the expansion member can be prevented from coming off the lumen wall of the lead.

[0071] (65) In the medical device of (64), the expansion member may be a coil in which a wire is wound around the outer periphery of the main body. With this configuration, for example, even if the pushing member is retracted after the expansion member is expanded, the expansion member can be prevented from coming off the lumen wall of the lead.

[0072] As used herein, "distal side" refers to the direction along the longitudinal direction of the main body, in the direction in which the medical device is pushed in (e.g., the distal direction of a lead). "Proximal side" refers to the direction along the longitudinal direction of the main body, in the opposite direction to the distal side. "Distal" refers to the distal end of any component. "Proximal end" refers to the proximal end of any component. "Distal portion" refers to the region between the distal end of any component and a position midway between the distal end and the proximal end of that component. "Proximal end" refers to the region up to the proximal end of any component, which is located proximal to the midway position. "Radial direction" refers to the direction perpendicular to the longitudinal direction of the main body.

[0073] 1. A schematic side view showing the first embodiment, showing an expansion member in an unexpanded state.

[0023] FIG. 1 is a schematic cross-sectional view showing an embodiment of the core shaft of FIG. 1.

[0024] FIG. 1 is a schematic cross-sectional view showing an enlarged view of the expansion member of FIG. 1.

[0025] FIG. 1 is a schematic cross-sectional view showing an embodiment of the coil of FIG. 1.

[0026] FIG. 1 is a schematic cross-sectional view showing an enlarged view of the expansion member of FIG. 1.

[0027] FIG. 1 is a schematic cross-sectional view showing an embodiment of the pushing member of FIG. 1.

[0028] FIG. 1 is a schematic cross-sectional view showing an embodiment of the pushing loop member.

[0029] FIG. 8 is a schematic cross-sectional view taken along line IX-IX of FIG. 8.

[0029] FIG. 11 is a schematic cross-sectional view showing an enlarged view of the fixation mechanism of FIG. 1.

[0030] FIG. 12 is a schematic cross-sectional view showing a state when fixed by the fixation mechanism of FIG. 11.

[0031] FIG. 13 is a schematic side view showing an enlarged view of the gripping member of FIG. 1.

[0032] FIG. 14 is a schematic cross-sectional view showing an embodiment of the gripping member.

[0033] FIG. 15 is a partially enlarged schematic cross-sectional view showing the first embodiment in use, showing an expansion member in an unexpanded state within the lead.

[0034] FIG. 16 is a partially enlarged schematic cross-sectional view showing the first embodiment in use, showing an expansion member in an expanded state within the lead. 24 is a partially enlarged schematic cross-sectional view showing the first embodiment in use, showing a state in which the expansion member is expanded within the lead. FIG. 25 is a schematic diagram showing a method for measuring expansion force. FIG. 26 is a conceptual diagram showing the distribution of expansion force of the expansion member. FIG. 27 is a schematic side view showing the second embodiment, showing a state in which the expansion member is not expanded. FIG. 28 is a schematic side view showing an enlarged schematic cross-sectional view of the expansion member of FIG. 20. FIG. 29 is a schematic side view showing an enlarged schematic cross-sectional view of a portion of the expansion member of FIG. 20. FIG. 29 is a schematic side view showing an enlarged schematic cross-sectional view of a portion of the third embodiment. FIG. 29 is a schematic cross-sectional view showing a fourth embodiment, showing a state in which the expansion member is not expanded. FIG. 29 is a schematic cross-sectional view showing an enlarged schematic cross-sectional view of the non-expandable portion of FIG. 24. FIG. 29 is a schematic cross-sectional view showing one aspect of the non-expandable portion. FIG. 29 is a schematic side view showing an enlarged schematic side view of the expansion member of the fifth embodiment, showing a state in which the expansion member is not expanded. FIG. 29 is a schematic side view showing the expansion member of FIG. 27 in an expanded state. FIG. 29 is a schematic side view showing the expansion member of FIG. 27 in an expanded state. FIG. 30 is a schematic side view showing an aspect of the sixth embodiment. FIG. 31 is a schematic side view showing an aspect of the sixth embodiment.39 is a schematic side view showing a fixing mechanism of a seventh embodiment. 40 is a schematic cross-sectional view showing a fixing mechanism of an eighth embodiment. 41 is a schematic side view showing an expansion member of a ninth embodiment, showing the expansion member in an unexpanded state. 42 is a schematic side view showing the expansion member of FIG. 35 in an expanded state. 43 is a schematic cross-sectional view showing the expansion member of a tenth embodiment, showing the expansion member in an unexpanded state. 44 is a schematic cross-sectional view showing the expansion member of FIG. 37 in an expanded state. 45 is a schematic cross-sectional view showing the expansion member of an eleventh embodiment, showing the expansion member in an unexpanded state. 46 is a schematic cross-sectional view showing the expansion member of FIG. 39 in an expanded state.

[0074] The medical device disclosed herein is, for example, a device for removing a lead placed in the body. During use, the medical device is inserted into the lumen of the lead and pushed through the lumen of the lead until the tip is positioned near the tip of the lead. With the tip of the medical device positioned near the tip of the lead, the pusher member is manually moved toward the distal end of the medical device by the operator (physician). The tip of the pusher member pushes the proximal end of the expansion member toward the distal end, compressing the expansion member along the longitudinal direction. As the expansion member is compressed, it expands radially outward from the medical device. As the expansion member expands, it begins to expand from the distal end of the expansion member, and then expansion progresses toward the proximal end of the expansion member. The distal end of the expansion member, which expanded first, abuts against the inner circumference of the lead, fixing the distal end of the medical device to the distal end of the lead. Then, the portion of the expansion member proximal to the distal end abuts against the inner circumference of the lead, just like the tip. The operator pulls the medical device temporarily fixed to the lead toward the proximal end (proximal side), thereby removing the lead.

[0075] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments shown in the drawings. The dimensions of each part shown in the drawings are shown to facilitate understanding of the implementation content and do not necessarily correspond to the actual dimensions.

[0076] 1 to 8, 10 to 13, 15 to 17, and 20 to 40, the left side of the figure is the tip side into which the medical device is pushed, and the right side is the base side (hand side) operated by a technician such as a doctor.

[0077] 1 to 17 are schematic diagrams showing a first embodiment. As shown in Fig. 1, a medical device 1 generally includes a main body 11, a tip fixation portion 21, an expansion member 31, a pushing member 41, a fixing mechanism 51, and a gripping member 61.

[0078] The main body 11 is an elongated member. Specifically, the main body 11 can be formed, for example, by a core shaft (hereinafter also referred to as "core shaft 11") formed in a linear shape from a metal such as a stainless steel alloy. The main body 11 may be formed, for example, so that its outer diameter varies along the longitudinal direction. In the medical device 1, the portion of the main body 11 located inside the expansion member 31 is a small diameter portion 111 having a constant outer diameter. The portion of the main body 11 located closer to the base end than the small diameter portion 111 is a large diameter portion 112 having an outer diameter larger than the small diameter portion 111. The main body 11 extends from the tip of the expansion member 31 to the tip of the gripping member 61.

[0079] The material for forming the main body 11 preferably has antithrombogenicity and biocompatibility while ensuring flexibility. Examples of such materials include stainless steel alloys such as SUS304 and superelastic alloys such as Ni-Ti alloys.

[0080] 2, the core shaft 11 may have a distal core shaft 11A and a proximal core shaft 11B joined to the proximal end of the distal core shaft 11A and extending toward the proximal end. In this case, the bending rigidity of the proximal core shaft 11B may be greater than the bending rigidity of the distal core shaft 11A. This allows the medical device 1 to be pushed forward so that the distal end of the medical device 1 can easily follow the curved lumen of the lead inside the body while maintaining the pushability of the medical device 1.

[0081] The distal core shaft 11A may be made of a Ni-Ti alloy, and the proximal core shaft 11B may be made of a stainless steel alloy. The rigidity of the Ni-Ti alloy is lower than that of the stainless steel alloy. This allows the aforementioned excellent pushability and followability to be achieved.

[0082] When the pushing member is formed of a cylindrical body 41 as described below, the joint portion 11a between the distal core shaft 11A and the proximal core shaft 11B may be covered by the cylindrical body 41. For example, regardless of the position of the cylindrical body 41 relative to the core shaft 11, the joint portion 11a between the distal core shaft 11A and the proximal core shaft 11B may always be located in the lumen 41h of the cylindrical body 41. Covering the joint portion 11a with the cylindrical body 41 can prevent bending stress from concentrating on the joint portion 11a when the medical device 1 is bent. As a result, bending of the core shaft at the joint portion 11a can be prevented.

[0083] The distal end fixing portion 21 is a portion where the distal end of the main body 11 and the distal end of the expansion member 31 are integrally fixed. As shown in Fig. 3, the distal end fixing portion 21 can be specifically formed, for example, so that its distal end has a generally hemispherical shape that is convexly curved toward the distal end. This can reduce resistance when the medical device 1 advances through the lumen of the lead, for example. As a result, the medical device 1 can be smoothly inserted into the lumen of the lead.

[0084] The tip fixing portion 21 can be formed, for example, by melting a portion of the member that forms the core shaft 11 and / or the expansion member 31 (e.g., a coil), or by using a brazing material or solder material to join the core shaft 11 and the expansion member 31. Examples of brazing material and solder material include alloys such as Sn—Pb alloy, Pb—Ag alloy, Sn—Ag alloy, and Au—Sn alloy.

[0085] The expansion member 31 is a member that covers the outer periphery of the main body 11 and is expandable radially outward. Specifically, as shown in Fig. 3, the expansion member 31 may be formed, for example, as a coil (hereinafter also referred to as "coil 31") in which a wire w1 is wound around the outer periphery of the main body 11. This makes it possible to easily form the expansion member 31.

[0086] The wire w1 forming the coil 31 can be, for example, at least one of a solid wire and a twisted wire. A solid wire means one single wire. A twisted wire means a bundle of wires formed by twisting multiple single wires together in advance. The coil 31 can be formed by winding the wire w1 in at least one of a single-strand and multiple-strand configuration. The wire w1 may have, for example, a circular cross section. The wire w1 may have a rectangular cross section. In the medical device 1, the wire w1 is a single wire with a circular cross section. The coil 31 is a four-strand coil formed by winding four wires w1 together.

[0087] The material of the wire w1 forming the coil 31 is not particularly limited as long as it has the ease of expansion (expandability), antithrombogenicity, and biocompatibility of the expansion member 31. Examples of such materials include stainless steel alloys such as SUS316 and superelastic alloys such as Ni-Ti alloys.

[0088] The wires w1 may have a radiopaque portion (e.g., a radiopaque wire w11). All of the wires w1 forming the coil 31 may be radiopaque wires w11. Only some of the wires w1 may be radiopaque wires w11. In this embodiment, only one of the four wires w1 is formed of a radiopaque wire w11 (for convenience, in FIG. 4, only one radiopaque wire w11 is shown painted black). Examples of radiopaque materials include metals such as gold, platinum, tungsten, and lead, as well as materials containing these metals. This allows the position of the expansion member 31 to be easily determined under X-ray fluoroscopy.

[0089] When the expansion member 31 is in an expanded state, at least a portion of the expansion member 31 may be plastically deformed. In this embodiment, since the expansion member 31 is formed of a coil, the expanded state of the expansion member can be maintained by plastically deforming at least a portion of the wires w1 of the coil 31. This makes it possible to prevent the expansion member 31 from coming off the lumen wall 80a (see FIG. 15 ) of the lead, for example, even if the pusher member 41 is retracted after the expansion member 31 is expanded.

[0090] The coil 31 has a first portion 31A, a second portion 31B, and a third portion 31C.

[0091] 3 , in the medical device 1, the distal end portion of the coil 31 is the first portion 31A. The proximal end portion of the coil 31 that is continuous with the first portion 31A is the second portion 31B. The proximal end portion of the coil 31 that is continuous with the second portion 31B is the third portion 31C. That is, the second portion 31B is the portion of the coil 31 that is located closer to the proximal end than the first portion 31A. The third portion 31C is the portion of the coil 31 that is located closer to the proximal end than the second portion 31B.

[0092] The tip of the expansion member 31 (the tip of the first portion 31A) may be located, for example, within 10 mm from the tip of the main body 11 toward the base end in the longitudinal direction of the main body 11. This allows the tip portion of the expansion member 31 to be located near the tip of the main body 11, so that the expansion member 31 can be expanded at the tip portion of the medical device 1.

[0093] As shown in FIG. 5 , the maximum width a1 of the wire w1 at the first portion 31A is smaller than the maximum width a2 of the wire w1 at the second portion 31B. Furthermore, in the medical device 1, the maximum width a1 of the wire w1 at the distal end (first portion 31A) of the coil 31 is smaller than the maximum width a3 of the wire w1 at the proximal end (third portion 31C) of the coil 31. In this disclosure, the "width of the wire" refers to the size of the wire in a direction perpendicular to the longitudinal direction of the wire. The "maximum width of the wire" refers to the maximum width of the wire. For example, if the cross section of the wire is circular (the wire is round), the maximum width of the wire is the diameter of the wire. If the cross section of the wire is rectangular (the wire is flat), the maximum width of the wire is the maximum thickness of the wire (the length of the short side of the wire).

[0094] In the medical device 1, the wire w1 is a round wire, and therefore the diameter of the wire w1 is the maximum width of the wire w1. The maximum width of the wire w1 in the first portion 31A is constant along the longitudinal direction. The maximum width of the wire w1 in the second portion 31B is constant along the longitudinal direction. The maximum width of the wire w1 in the third portion 31C is constant along the longitudinal direction.

[0095] The maximum width of the wire w1 may gradually increase from the distal end toward the proximal end of the coil 31. Specifically, the maximum width of the wire w1 may gradually increase from the distal end of the first portion 31A toward the proximal end of the third portion 31C. This allows the expansion member 31 to be gradually expanded from the distal end toward the proximal end.

[0096] In the first portion 31A and the second portion 31B, adjacent wires w1 are not fixed to each other. In the third portion 31C, at least some of the adjacent wires w1 are fixed to each other. In the third portion 31C of the medical device 1, the four wires w1 wound in four rows are joined to each other. This allows the rigidity of the coil 31 in the third portion 31C to be higher than the rigidity of the first and second portions 31A and 31B.

[0097] 6 is a schematic side view showing a state in which the expansion member 31 of the medical device 1 is expanded when the medical device 1 is not inserted into the lumen of a lead 80 ( FIG. 15 ). As described above, when the lead 80 is removed from the body, the expansion member 31 is expanded while inserted into the lead 80, and the expansion portions (first portion 31A, second portion 31B) of the expansion member 31 are expanded until they abut against the inner circumference of the lead 80. One of the purposes of the medical device 1 is to ensure that the expansion portions (first portion 31A, second portion 31B) abut against the inner circumference of the lead 80 when the expansion member 31 is expanded inside the lead 80. The maximum widths (D1, D2) of the expansion portions (first portion 31A, second portion 31B) when expanded when not inserted into the lead 80 are formed to be larger than the inner diameter of the lead 80. By increasing the maximum widths (D1, D2) of the expansion sections (first region 31A, second region 31B) when expanded without being inserted into the lead 80, the expansion force of the expansion member 31 can be increased, thereby improving the fixation force between the lead 80 and the medical device 1. The greater the pitch (p1, p2) of the wires w1 of the expansion member 31, the greater the maximum widths (D1, D2) when expanded. In the medical device 1, the pitch p1 of the wires w1 in the first region 31A is greater than the pitch p2 of the wires w1 in the second region 31B. This allows the maximum width D1 of the expansion member 31 at the first region 31A when expanded to be greater than the maximum width D2 of the expansion member 31 at the second region 31B when not inserted into a lumen such as a lead 80. In this disclosure, the "maximum width of the expansion member" refers to the maximum dimension of the expansion member in the radial direction.

[0098] In the medical device 1, the pitch p1 of the wires w1 at the distal end (first portion 31A) of the coil 31 is larger than the pitch p3 of the wires w1 at the proximal end (third portion 31C) of the coil 31. This allows the maximum width D1 of the distal end (first portion 31A) of the coil 31 when the expansion member 31 is expanded to be larger than the maximum width D3 of the proximal end (third portion 31C) of the coil 31 when not inserted into the lumen of a lead or the like.

[0099] In the medical device 1, the pitch p1 of the wires w1 in the first portion 31A is constant along the longitudinal direction, the pitch p2 of the wires w1 in the second portion 31B is constant along the longitudinal direction, and the pitch p3 of the wires w1 in the third portion 31C is constant along the longitudinal direction.

[0100] The pitch of the wire w1 may gradually decrease from the distal end toward the proximal end of the coil 31. This allows the maximum width of the coil 31 when the expansion member 31 is expanded to gradually increase from the proximal end toward the distal end of the coil 31.

[0101] The expansion member 31 expands radially outward, for example, by pushing its base end toward the distal end with a pusher member 41 (described later). In the medical device 1, the distal end of the expansion member 31 is fixed at the distal fixation portion 21. Therefore, by pushing with the pusher member 41, the expansion member 31 is compressed and expanded along the longitudinal direction of the main body 11. The maximum width of the wires w1 at the first portion 31A of the expansion member 31 is smaller than the maximum width of the wires w1 at the portions proximal to the first portion 31A (the second portion 31B and the third portion 31C). Therefore, the stress generated at the distal end of the expansion member 31 due to longitudinal compression of the expansion member 31 is greater than the stress generated at the proximal end of the expansion member 31 due to longitudinal compression of the expansion member 31. As a result, due to the greater stress at the distal end of the expansion member 31, the distal end (first portion 31A) of the expansion member 31 begins to expand radially outward first. That is, when the expansion member 31 expands, the distal end of the expansion member 31 begins to expand radially outward before the proximal end of the expansion member 31. After the first portion 31A begins to expand, the second portion 31B begins to expand.

[0102] When the medical device 1 is not inserted into the lumen of a lead or the like, when the expansion member 31 expands, the maximum width D1 of the distal end (first portion 31A) of the expansion member 31 becomes greater than the maximum width D3 of the proximal end of the expansion member 31. As a result, when the expansion member 31 expands in the lumen of the lead, the force exerted by the distal end of the expansion member 31 against the lumen wall of the lead is greater than the force exerted by the proximal end of the expansion member 31 against the lumen wall of the lead. In other words, the expansion force of the distal end of the expansion member 31 is greater than the expansion force of the proximal end of the expansion member 31. This is because the pitch of the wires w1 forming the coil 31 is greater at the distal end than at the proximal end of the coil 31. As a result, for example, when the expansion member 31 expands, the distal end of the expansion member 31 can be more firmly fixed to the distal lumen wall of the lead. In this disclosure, the "expansion force" refers to the degree of force with which the expansion member presses the lumen wall of the lead or the like radially outward.

[0103] Fig. 18 is a schematic diagram showing a method for measuring the expansion force. The expansion force can be measured, for example, using an expansion force measuring device 70 as shown in Fig. 18. The expansion force can be obtained by measuring, with a load meter 71, the load that presses against a probe 72 when the expansion member expands radially outward. The value of the expansion force can be the arithmetic mean of five measured values.

[0104] Figure 19 is a conceptual diagram showing the distribution of the expansion force of the expansion member. In the figure, the horizontal axis represents the longitudinal position of the expansion member, and the vertical axis represents the expansion force. As shown in Figure 19, the expansion force increases toward the distal end of the coil and decreases toward the proximal end.

[0105] The pushing member 41 is a member that is movable along the longitudinal direction of the main body 11 and pushes the base end of the expansion member 31 toward the distal end side, thereby compressing the expansion member 31 along the longitudinal direction.

[0106] The shape of the pushing member 41 is not particularly limited. Specifically, as shown in FIG. 7 , the pushing member 41 may be formed, for example, as a cylindrical body (hereinafter also referred to as the "cylindrical body 41") that covers the outer periphery of the main body 11. This facilitates the formation of the pushing member 41. In the medical device 1, the maximum width r1 of the distal end 41a of the pushing member 41 is smaller than the maximum width r2 of the proximal end of the expansion member 31 that abuts against the distal end 41a of the pushing member 41. In the medical device 1, the maximum width of the pushing member 41 decreases toward the distal end. In the present disclosure, the "maximum width of the pushing member" refers to the maximum dimension of the pushing member in the radial direction. The "maximum width of the proximal end of the expansion member" refers to the maximum dimension of the proximal end of the expansion member in the radial direction. Having the maximum width r1 smaller than the maximum width r2 reduces the risk of the distal end of the pushing member 41 getting caught in the lumen of the lead 80, for example, and facilitates the insertion of the medical device 1 into the lead 80. Since the maximum width of the pushing member 41 decreases toward the tip side, the rigidity of the pushing member 41 decreases toward the tip side, allowing the pushing member 41 to easily pass through curved blood vessels.

[0107] The rigidity of the proximal end of the pushing member 41 may be greater than the rigidity of the distal end of the pushing member 41. This improves the pushability of the pushing member 41 and ensures that the pushing force is transmitted from the proximal end to the distal end of the pushing member 41. As shown in FIG. 7 , the pushing member 41 may have, for example, a reinforcing coil 411 that covers the outer periphery of the proximal end of the pushing member 41. The reinforcing coil 411 may be formed, for example, by winding a wire w2 around the outer periphery of the cylindrical body 41. This increases the rigidity of the proximal end of the pushing member 41. The reinforcing coil 411 may be fixed to the cylindrical body 41.

[0108] There is no particular limitation on the material of the wires w2 forming the reinforcing coil 411. Examples of such materials include stainless steel alloys such as SUS304.

[0109] 7 , a position marker 413 may be provided on the outer periphery of the proximal end of the pushing member 41. The configuration of the position marker 413 is not particularly limited as long as it allows the operator to identify the position of the proximal end of the pushing member 41. The color of the position marker 413 may be different from the color of the pushing member 41 so that the position of the marker can be visually confirmed. The tactile feel of the position marker 413 may be different from the tactile feel of the pushing member 41. This makes it easy to grasp the positional relationship between the main body 11 and the pushing member 41, and allows the fixing mechanism 51, described later, to be operated smoothly.

[0110] As shown in FIG. 7 , a pushing loop member 412 may be provided at the proximal end of the pushing member 41. Specifically, the pushing loop member 412 is formed in a loop shape so that, for example, forceps, tweezers, or the like can be inserted. This allows the pushing member 41 to be easily pushed toward the distal end using forceps, tweezers, or the like. The pushing loop member 412 may have its proximal end fixed between the outer periphery of the proximal end of the pushing member 41 and the inner periphery of the reinforcing coil 411, for example, so that the loop portion 412 a is located toward the distal end. This improves the bonding strength between the pushing loop member 412 and the pushing member 41.

[0111] The maximum width s1 of the pushing loop member 412 may be smaller than the maximum width s2 of the reinforcing coil 411. In this disclosure, the "maximum width of the pushing loop member" refers to the maximum dimension of the pushing loop member in a direction perpendicular to the longitudinal direction of the pushing member 41. The "maximum width of the reinforcing coil" refers to the maximum dimension of the reinforcing coil in the radial direction. This reduces interference between the pushing loop member 412 and other components (e.g., the lead 80, the sheath 90, etc.), allowing the medical device 1 to be easily inserted into the lead.

[0112] 8, the proximal end of the pushing loop member 412m has a first end t1 and a second end t2, and the first end t1 and the second end t2 may be spaced apart. For example, the pushing loop member 412m may be formed in a U-shape, which allows the first end t1 and the second end t2 to be spaced apart. This increases the size of the loop portion 412am, making it easier to insert forceps, tweezers, or the like into the loop portion 412am, improving the operability of the medical device.

[0113] The length s3 of the loop portion 412am of the pushing loop member 412m in the longitudinal direction of the main body 11 may be greater than the maximum width s2 of the reinforcing coil 411 (the outer diameter s2 of the reinforcing coil 411). In the present disclosure, the "length of the loop portion of the pushing loop member" refers to the maximum dimension of the pushing loop member exposed to the outside in the longitudinal direction of the pushing member 41. This increases the opening of the loop portion 412am, making it easier to insert forceps, tweezers, or the like into the loop portion 412am, improving the operability of the medical device.

[0114] 10 , the tip of the pushing loop member 412m may be located radially inside an imaginary cylindrical surface f that is an extension of the outer circumferential surface of the reinforcing coil 411. This prevents the tip of the pushing loop member 412m from getting caught on the lumen wall 80a of the lead 80 and hindering the advancement of the medical device when the medical device is pushed into the lead 80.

[0115] The fixing mechanism 51 is a mechanism capable of fixing the main body 11 and the pushing member 41. The fixing mechanism 51 fixes the main body 11 to the pushing member 51 by engaging the outer periphery of the main body 11 with the pushing member 51. As shown in FIG. 11 , the fixing mechanism 51 may have a curved portion 113 in which a portion of the core shaft 11 is curved. The curved portion 113 may be formed, for example, to protrude in a direction perpendicular to the longitudinal axis of the main body 11. As shown in FIG. 12 , the curved portion 113 abuts against the inner circumferential surface 41b of the pushing member 41, thereby fixing the main body 11 and the pushing member 41 by the frictional force between the main body 11 and the pushing member 41. This allows the main body 11 and the pushing member 41 to be fixed with a simple configuration.

[0116] The fixing mechanism 51 may be formed with only one curved portion 113, or may be formed with two or more curved portions 113. The fixing mechanism 51 may have, for example, a first curved portion 113A in which the core shaft 11 is curved in a first direction, and a second curved portion 113B in which the core shaft 11 is curved in a second direction different from the first direction. In the medical device 1, the fixing mechanism 51 has the first curved portion 113A and the second curved portion 113B arranged in a zigzag pattern. In the medical device 1, the first curved portion 113A and the second curved portion 113B are formed so that the main body 11 itself meanders with respect to the longitudinal axis of the main body 11. This allows the main body 11 and the pushing member 41 to be fixed with a simple configuration.

[0117] As shown in FIGS. 11 and 12 , the main body 11 may have a first marker 511 at a location distal to the tip of the fixing mechanism 51. The main body 11 may also have a second marker 512 at a location proximal to the base of the fixing mechanism 51. By providing such markers 511, 512, it is possible to easily determine whether the fixing mechanism 51 is operating. The first and second markers 511, 512 are not particularly limited as long as the operator can identify their positions. The colors of the first and second markers 511, 512 may be different from the colors of other parts (e.g., the pushing member 41, the gripping member 61, etc.) so that the positions of the markers can be visually confirmed. The tactile sensation of the first and second markers 511, 512 may be different from the tactile sensation of other parts.

[0118] The first marker 511 and the second marker 512 may each be a metal oxide coating formed on the surface of the main body 11. The metal oxide coating can be formed, for example, by forming the main body 11 from a metal material such as a stainless steel alloy or a nickel-titanium alloy and heat-treating the surface of this metal material in an oxidizing atmosphere. The color of the metal oxide coating may be different from the color of the metal of the main body 11. The tactile feel of the metal oxide coating may be different from the tactile feel of the metal of the main body 11. This makes it possible to easily form the first and second markers 511, 512.

[0119] The gripping member 61 is a flexible member that is disposed closer to the proximal end than the pushing member 41 and is connected to the proximal end of the main body 11. The gripping member 61 is gripped by the operator when operating the medical device 1. As shown in Fig. 13 , the gripping member 61 may be connected by fixing its tip to the proximal end of the main body 11.

[0120] The shape of the gripping member 61 is not particularly limited. The gripping member 61 may be formed, for example, by spirally winding the wire w3. This allows the gripping member 61 to be easily and reliably gripped. For example, by wrapping the gripping member 61 around the hand, the operator can reliably pull the lead out of the body when removing the lead. The length of the gripping member 61 in the longitudinal direction may be greater than the length of the pusher member 41 in the longitudinal direction. This allows the gripping member 61 to be easily wrapped around the operator's hand, for example.

[0121] The wires w3 forming the gripping member 61 may include a core wire 61Aw and a side wire 61Bw wound around the core wire 61Aw. The core wire 61Aw can be formed, for example, by winding one or more solid or twisted wires. The core wire 61Aw serves as the central axis of the gripping member 61. The side wire 61Bw can be formed, for example, by winding one or more solid or twisted wires spirally around the core wire 61Aw. As shown in FIG. 14 , the gripping member 61 of this embodiment includes a core wire 61Aw formed of a single twisted wire consisting of seven wires w31, and a side wire 61Bw formed by spirally winding eight twisted wires each consisting of seven wires w32 around the core wire 61Aw. This makes the gripping member 61 flexible and prevents it from becoming bent.

[0122] In the medical device 1, a gripping loop member 611 is provided at the proximal end of a tubular gripping member 61. Specifically, the gripping loop member 611 is formed in a loop shape so that, for example, forceps, tweezers, or the like can be inserted. The distal end of the gripping loop member 611 may be fixed to the inner circumference of the proximal end of the tubular gripping member 61 so that the loop portion 611a is located on the proximal end side. This allows, for example, when using a sheath 90 described below, the medical device 1 to be easily pulled while hooking forceps or the like on the gripping loop member 611.

[0123] The maximum width b1 of the gripping loop member 611 may be smaller than the maximum width b2 of the gripping member 61. In the present disclosure, the "maximum width of the gripping loop member" refers to the maximum dimension of the gripping loop member in a direction perpendicular to the longitudinal direction of the gripping member 61. This can reduce interference between the gripping loop member 611 and other members (e.g., the gripping member 61, the sheath 90, etc.), thereby improving the operability of the medical device 1.

[0124] Next, a description will be given of how the medical device 1 is used with reference to Figures 15 to 17. Here, a description will be given of a procedure for removing a hollow lead 80 extending from a pacemaker implanted in the heart to the outside of the body using the medical device 1. The lead 80 shown has a first electrode 81 located at the tip of the lead 80 and a second electrode 82 located closer to the base end than the first electrode 81.

[0125] First, using the medical device 1 with the expansion member 31 in an unexpanded state, the expansion member 31 is inserted into the lumen 80h of the lead 80, as shown in Fig. 15. Specifically, the distal fixation portion 21 of the medical device 1 is inserted into the lumen 80h from the proximal end of the lead 80 that has been detached from the pacemaker. Next, the medical device 1 is pushed forward in the lumen 80h, and the medical device 1 is delivered so that the distal end of the expansion member 31 is positioned in the lumen of the lead 80 distal to the second electrode 82.

[0126] Next, the fixation between the main body 11 and the pushing member 41 is released. Specifically, the engagement between the main body 11 and the pushing member 41 by the fixing mechanism 51 is released by moving the pushing member 41 toward the distal end along the longitudinal direction of the main body 11. At this time, as shown in FIG. 11 , the first curved portion 113A and the second curved portion 113B provided on the main body 11 move away from the inner circumferential surface 41b of the pushing member 41, thereby releasing the engagement between the main body 11 and the pushing member 41.

[0127] Next, the expansion member 31 is expanded radially outward to secure the expansion member 31 to the lead 80. Specifically, while the distal end of the pushing member 41 is in contact with the proximal end of the expansion member 31, the pushing member 41 is further moved distally along the longitudinal direction of the main body 11. At this time, as shown in FIG. 16 , the expansion member 31 begins to expand radially outward from the first portion 31A. As shown in FIG. 17 , by further moving the pushing member 41 distally, the second portion 31B expands. In the expanded state, the outer periphery of the expansion member 31 (first portion 31A) abuts against the inner periphery (inner cavity wall 80a) of the lead 80 distal to the second electrode 82. The expansion of the expansion member 31 progresses from the distal end toward the proximal end of the expansion member 31, and the contact area between the expansion member 31 and the lead 80 expands. This allows the lead 80 and the medical device 1 to be secured at a more distal position of the lead 80.

[0128] Next, the lead 80 inside the body is removed outside the body. Specifically, the medical device 1 (see FIG. 17 ), with the expansion member 31 fixed to the lead 80, is pulled toward the proximal end while the gripping member 61 is grasped, thereby removing the lead 80 outside the body. Sometimes, tissue may adhere to the lead 80. In such cases, as shown in FIG. 15 , a sheath 90 may be placed over the outer surface of the lead 80, and adhesions may be removed using a dissection device 91 provided at the distal end of the sheath 90. Examples of the dissection device 91 include a device provided at the distal end of the sheath 90 that dissolves adhesions by irradiating the distal end with laser light. This allows the hollow lead 80 inside the body to be removed outside the body using the medical device 1.

[0129] As described above, because the medical device 1 has the above-described configuration, the distal end of the expansion member 31 begins to expand radially outward before the proximal end of the expansion member 31. As a result, for example, when removing a hollow lead 80 from the body, the distal end of the expansion member 31 can be fixed distal to the lead 80, and the hollow lead 80 implanted in the body can be smoothly removed.

[0130] The medical device 1 includes a pushing member 41. As a result, the pushing member 41 can compress the expansion member 31 along the longitudinal direction of the main body 11, and the expansion member 31 can be reliably expanded.

[0131] The medical device 1 includes a fixing mechanism 51. As a result, the main body 11 and the pushing member 41 can be fixed together, and when the medical device 1 is not in use, the expansion member 31 can be prevented from expanding.

[0132] The medical device 1 includes a gripping member 61. As a result, by operating the medical device 1 while gripping the gripping member 61, the expansion member 31 can be easily expanded and the lead 80 can be easily pulled out.

[0133] [Second Embodiment] Figures 20 to 22 are schematic diagrams showing a second embodiment. As shown in Figure 20, the medical device 2 generally comprises a main body 11, a tip fixing portion 21, an expansion member 32, a pushing member 41, a fixing mechanism 51, and a gripping member 61. The second embodiment differs from the first embodiment in that it comprises an expansion member 32. The configurations of the main body 11, tip fixing portion 21, pushing member 41, fixing mechanism 51, and gripping member 61 are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals and detailed descriptions thereof will be omitted. The configuration is the same as that of the expansion member 31, except for the configuration of the expansion member 32, which will be described below. The usage of the medical device 2 is the same as that of the medical device 1.

[0134] The expansion member 32 is a member that covers the outer periphery of the main body 11 and is expandable radially outward. The expansion member 32 of the medical device 2 is formed of a coil (hereinafter also referred to as the “coil 32”) in which a wire w1 is wound around the outer periphery of the main body 11.

[0135] 21 , the expansion member 32 of the medical device 2 has an expansion section 321 that is expandable radially outward and a non-expandable section 322 that is located distal to the expansion section 321 and does not expand radially outward. The coil 32 of the medical device 2 has a fourth section 32D distal to the first section 32A. In the medical device 2, for example, the expansion section 321 corresponds to the first section 32A, the second section 32B, and the third section 32C, and the non-expandable section 322 corresponds to the fourth section 32D.

[0136] As shown in FIG. 22 , the non-expandable portion 322 has a joint portion 322a and a non-joint portion 322b. The distal end and proximal end of the non-expandable portion 322 are fixed to the main body 11 at the joint portions 322a. The portion of the non-expandable portion 322 between the distal end and proximal end of the non-expandable portion 322 is the non-joint portion 322b, which is not fixed to the main body 11. The non-expandable portion 322 does not expand radially outward. Because the coil 32 is fixed at both ends of the non-joint portion 322b at the joint portions 322a, the coil 32 of the non-expandable portion 322 is not compressed along the longitudinal direction of the main body 11. For this reason, the non-expandable portion 322 does not expand radially outward even when the pushing member 41 is moved, for example.

[0137] The bending rigidity of the non-bonded portion 322b may be smaller than the bending rigidity of any of the bonded portions 322a. In the medical device 2, the bending rigidity of the non-bonded portion 322b is smaller than the bending rigidity of the bonded portions 322a provided at the distal and proximal ends of the non-expandable portion 322. Such a distribution of bending rigidity of the non-expandable portion 322 can be obtained by bonding the coil 32 to the main body 11 only at the bonded portion 322a of the non-expandable portion 322. As a result, for example, when the medical device 2 is inserted into a portion of the lead 80 that has a large degree of curvature, the non-bonded portion 322b bends along the curvature of the lead 80, improving the passability of the medical device 2.

[0138] The X-ray transmittance of the non-expansion portion 322 may be smaller than the X-ray transmittance of the expansion portion 321. Specifically, for example, a portion containing an X-ray opaque material may be provided in at least a part of the non-expansion portion 322. This makes it possible to easily grasp the position of the non-expansion portion 322 of the expansion member 32 under X-ray fluoroscopy.

[0139] Examples of radiopaque materials include gold, platinum, tungsten, and alloys containing these elements.

[0140] The joining method of the joint 322a is not particularly limited. A solder material containing gold is used for the joint 322a of the medical device 2. The fourth portion 32D is fixed (joined) to the main body 11 by the solder material containing gold.

[0141] Examples of the solder material containing gold include gold, Au—Sn alloys, Au—Ge solder, Au—Si solder, Au—In solder, and Au—Sb solder, etc. As a result, the gold contained in the solder material of fourth portion 32D functions as an X-ray opaque material, and fourth portion 32D can be easily identified under X-ray fluoroscopy.

[0142] As described above, since the medical device 2 has the above-described configuration, the distal end of the expansion portion 321 begins to expand radially outward before the proximal end of the expansion portion 321. As a result, for example, when removing the hollow lead 80 from the body, the distal end of the expansion portion 321 can be fixed distal to the lead 80, and the hollow lead 80 implanted in the body can be smoothly removed.

[0143] In the medical device 2, a non-expandable portion 322 (fourth portion 32D) is provided in the expansion member 32, and the non-expandable portion 322 has a non-bonded portion 322b. As a result, since the non-expandable portion 322 has the non-bonded portion 322b, the flexibility of the non-expandable portion 322 can be improved.

[0144] [Third Embodiment] Figure 23 is a schematic side view showing an enlarged portion of the third embodiment. As shown in Figure 23, the medical device 3 generally includes a main body 11, a distal fixation portion 21, an expansion member 31, a radiopaque marker 35, a push-in member 41, and a fixing mechanism 51 and a gripping member 61 (not shown). The third embodiment differs from the first embodiment in that it includes the radiopaque marker 35. The configurations of the main body 11, the distal fixation portion 21, the expansion member 31, the push-in member 41, the fixing mechanism 51, and the gripping member 61 are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals and detailed descriptions thereof will be omitted. The usage of the medical device 3 is the same as that of the medical device 1.

[0145] The radiopaque marker 35 is provided closer to the distal end than the first portion 31A, and is a member having a lower X-ray transmittance than other portions (e.g., the main body 11, the expansion member 31, etc.) of the medical device 3. The radiopaque marker 35 may be, for example, the distal fixing portion 21 containing a radiopaque brazing material, a coil formed of a radiopaque wire, or the like.

[0146] Examples of materials used for the radiopaque marker 35 include metal materials such as gold, platinum, tungsten, and lead, and materials containing these metal materials. The medical device 3 includes a coil (hereinafter also referred to as "coil 35") formed of a wire w4 containing platinum as the radiopaque marker 35. The tip of the coil 35 is connected to the main body 11 at the tip fixing portion 21, and the base end is joined to the tip of the coil 31.

[0147] As described above, since the medical device 3 has the above-described configuration, the position of the distal end of the first portion 31A can be easily grasped under X-ray fluoroscopy.

[0148] [Fourth Embodiment] Figures 24 to 26 are schematic diagrams showing a fourth embodiment. As shown in Figure 24, the medical device 4 generally comprises a main body 14, a tip fixation section 21, an expansion member 32, a pushing member 44, a fixing mechanism 51, and a gripping member 61 (not shown). The fourth embodiment differs from the second embodiment in that it comprises the main body 14 and the pushing member 44. The configurations of the tip fixation section 21, the fixing mechanism 51, and the gripping member 61 are the same as those of the second embodiment. Therefore, the same components are denoted by the same reference numerals and detailed descriptions thereof are omitted. The configurations of the main body 14 and the pushing member 44, other than those described below, are the same as those of the first embodiment. The usage of the medical device 4 is the same as that of the medical device 1.

[0149] The main body 14 is an elongated member. In the medical device 4, the main body 14 is a core shaft (hereinafter also referred to as "core shaft 14"). The small diameter portion 141 of the core shaft 14 has, in order from its tip to its base end, a first tapered portion 141A, a first straight portion 141B, a second tapered portion 141C, and a second straight portion 141D.

[0150] The first tapered portion 141A is a portion whose diameter gradually increases toward the base end. The first tapered portion 141A is disposed on the distal side of the distal end of the expansion portion 321. The distal end of the first tapered portion 141A is fixed to the distal end fixing portion 21.

[0151] In the medical device 4, the outer periphery of the first tapered portion 141A is covered with the non-expandable portion 322. The portion of the first tapered portion 141A that is covered with the non-expandable portion 322 may be the entire first tapered portion 141A, or may be a part of the first tapered portion 141A. By having the core shaft 14 have the first tapered portion 141A, the flexibility of the distal end of the medical device 4 can be increased, thereby improving the pushability and followability.

[0152] As shown in Fig. 25, the outer periphery of the proximal end of the first tapered section 141A1 may be covered with a bonded section 322a. As shown in Fig. 26, the outer periphery of the proximal end of the first tapered section 141A2 may be covered with a non-bonded section 322b. When the proximal end of the first tapered section 141A2 is covered with the non-bonded section 322b, the flexibility of the distal end of the medical device 4 can be increased, thereby improving the pushability and followability.

[0153] The first straight portion 141B is a portion with a constant outer diameter that extends from the base end of the first tapered portion 141A toward the base end. The first straight portion 141B is provided so that its tip is continuous with the base end of the first tapered portion 141A. The outer periphery of the first straight portion 141B is covered with the expansion portion 321. This allows the expansion portion 321 to expand while maintaining the flexibility of the tip portion of the medical device 4.

[0154] 24, the second tapered portion 141C is located closer to the base end than the base end of the first straight portion 141B and gradually increases in diameter toward the base end. The second tapered portion 141C can be provided, for example, so that its tip is continuous with the base end of the first straight portion 141B.

[0155] The second straight portion 141D is a portion with a constant outer diameter that extends from the base end of the second tapered portion 141C toward the base end. The second straight portion 141D is provided so that its tip is continuous with the base end of the second tapered portion 141C.

[0156] The pushing member 44 is a member that is movable along the longitudinal direction of the main body 14 and pushes the base end of the expansion member 32 toward the distal end side. The pushing member 44 is formed of a tubular body.

[0157] The outer periphery of the second straight portion 141D, or the outer peripheries of the second tapered portion 141C and the second straight portion 141D, may always be covered by the pushing member 44. In the medical device 4, both the second tapered portion 141C and the second straight portion 141D are covered by the pushing member 44.

[0158] The main body 14 has the second tapered portion 141C and the second straight portion 141D, and the outer periphery of the second straight portion 141D is covered with the pushing member 44, thereby ensuring the rigidity of the medical device 4 on the proximal side of the expansion member 32 while increasing the flexibility of the distal portion of the medical device 4. As a result, the passability of the distal portion of the medical device 4 can be improved.

[0159] As described above, the medical device 4 has the above-described configuration, which increases the flexibility of the distal end of the medical device 4 and improves the pushability and followability. The diameter of the main body of the medical device 4 decreases in one direction from the second straight portion 141D to the first tapered portion 141A. Therefore, the flexibility of the medical device 4 increases toward the distal end of the main body 14, further improving the followability.

[0160] Fifth Embodiment Figures 27 to 29 are schematic diagrams showing a fifth embodiment. The medical device 5 generally comprises a main body 11, a tip fixing portion 21, an expansion member 35, a pushing member 41, and a fixing mechanism 51 and a gripping member 61 (not shown). The fifth embodiment differs from the first embodiment in that it comprises an expansion member 35. The configurations of the main body 11, tip fixing portion 21, pushing member 41, fixing mechanism 51, and gripping member 61 are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. The configuration of the expansion member 35, other than the configuration of the expansion member 35 described below, is the same as that of the first embodiment. The usage of the medical device 5 is the same as that of the medical device 1.

[0161] 27 , the expansion member 35 is a member that covers the outer periphery of the main body 11 and is expandable radially outward. The expansion member 35 of this embodiment is a coil (hereinafter also referred to as “coil 35”) in which a wire w1 is wound around the outer periphery of the main body, and is formed so that the outer diameter D4 of the tip of the coil 35 is smaller than the outer diameter D5 of the base end of the coil 35.

[0162] The coil 35 may be shaped so that its outer diameter gradually decreases from its base end to its tip. The ratio (outer diameter ratio) of the outer diameter D4 of the tip of the coil 35 to the outer diameter D5 of the base end of the coil 35 is not particularly limited. The outer diameter ratio D4 / D5 of the coil 35, the pitch of the wires w1, and the like can be selected so that the tip of the coil 35 first contacts the lumen wall 80a of the lead 80 when the coil 35 expands radially outward.

[0163] When using the medical device 5, the pushing member 41 pushes the proximal end of the expansion member 35 toward the distal end, causing the expansion member 35 to begin expanding from the distal end, as shown in Fig. 28 . The expansion of the expansion member 35 then progresses toward the proximal end, and the proximal portion of the expansion member 35 comes into contact with the inner circumference of the lead 80, just like the distal end, as shown in Fig. 29 . This allows the distal end of the expansion member 35 to be fixed to the distal lumen wall 80a of the lead 80.

[0164] As described above, in the medical device 5, when the expansion member 35 is not expanded, the outer diameter D4 of the distal end of the coil 35 is smaller than the outer diameter D5 of the proximal end of the coil 35. Therefore, the medical device 5 can be smoothly pushed forward through the lumen 80h of the lead 80.

[0165] Sixth Embodiment Figures 30 to 32 are schematic diagrams showing a sixth embodiment. The medical device 6 generally comprises a main body 11, a tip fixing portion 21, an expansion member 31, a reinforcing member 76, a pushing member 41, and a fixing mechanism 51 and a gripping member 61 (not shown). The sixth embodiment differs from the first embodiment in that it comprises a reinforcing member 76. The configurations of the main body 11, tip fixing portion 21, expansion member 31, pushing member 41, fixing mechanism 51, and gripping member 61 are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. The manner of use of the medical device 6 is the same as that of the medical device 1.

[0166] The reinforcing member 76 is a member that is disposed between the outer periphery of the main body 11 and the inner periphery of the expansion member 31 and extends along the longitudinal direction of the main body 11. The reinforcing member 76 is provided, for example, to fill the gap between the main body 11 and the expansion member 31.

[0167] There are no particular limitations on the form of the reinforcing body 76. Examples of the reinforcing body 76 include an inner coil 761, a braided body 762, and a resin tube 763 (hereinafter also referred to as a "resin tube 763").

[0168] Fig. 30 shows a medical device 6A in which the reinforcing body 76 is an inner coil 761. As shown in Fig. 30, the inner coil 761 is a member in which the wire w5 is wound in a spiral shape on the outer peripheral surface of the main body 11. For example, the wire w5 may be tightly wound on the outer peripheral surface of the main body 11 so that no gaps are formed between adjacent wires w5 along the longitudinal direction. By winding the wire w5, the reinforcing body 76 can be easily formed.

[0169] Fig. 31 shows a medical device 6B in which the reinforcing body 76 is a braided body 762. As shown in Fig. 31, the braided body 762 is, for example, a member in which wires w6 are woven into a mesh shape. By forming the reinforcing body 76 with the braided body 762, it is possible to reinforce the main body 11 while maintaining flexibility.

[0170] Figure 32 shows a medical device 6C in which the reinforcing body 76 is a resin tube 763. As shown in Figure 32, the resin tube 763 is, for example, a flexible member that surrounds the main body 11 so as to closely fit the main body 11. Examples of resins that can be used to form the resin tube 763 include polyurethane, polyamide elastomer, and polytetrafluoroethylene (PTFE). By forming the reinforcing body 76 from the resin tube 763, the gap between the main body 11 and the expansion member 31 can be continuously filled, effectively preventing the expansion member 31 from twisting in the circumferential direction.

[0171] As described above, the medical device 6 includes the reinforcing body 76, which fills the gap between the main body 11 and the expansion member 31, thereby preventing the expansion member 31 from deforming radially inward. As a result, the expansion member 31 can be prevented from twisting in the circumferential direction and expanding asymmetrically.

[0172] Seventh Embodiment Figure 33 is a schematic diagram showing a seventh embodiment. The medical device 7 generally comprises a main body 11, a pushing member 41, a fixing mechanism 57, a gripping member 61, and a tip fixation portion 21 and an expansion member 31 (not shown). The seventh embodiment differs from the first embodiment in that it comprises a fixing mechanism 57. The configurations of the main body 11, tip fixation portion 21, expansion member 31, pushing member 41, and gripping member 61 are the same as those of the first embodiment. Therefore, the same components are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0173] The fixing mechanism 57 fixes the pushing member 41 and the gripping member 61 to each other so that they do not move relative to each other along the longitudinal direction of the main body 11. As shown in Fig. 33 , the fixing mechanism 57 of the medical device 7 is a resin fixing tube 57 (hereinafter also referred to as the "fixing tube 57") that covers the outer peripheries of the pushing member 41 and the gripping member 61 and fixes the pushing member 41 and the gripping member 61. The distal end of the fixing tube 57 is removably fixed to the proximal end of the pushing member 41, and the proximal end of the fixing tube 57 is removably fixed to the distal end of the gripping member 61. The fixing tube 57 is connected to straddle the pushing member 41 and the gripping member 61.

[0174] The material for forming the fixing tube 57 is not particularly limited as long as it can fix the pushing member 41 and the gripping member 61. Examples of materials for forming the fixing tube 57 include fluoropolymers such as perfluoroalkoxyalkane (PFA) and perfluoroethylenepropene copolymer (FEP), silicone, and polyolefin.

[0175] When using the medical device 7, for example, just before expanding the expansion member 31, the fixing tube 57 is detached from the pushing member 41 and the gripping member 61 by sliding the fixing tube 57 along the longitudinal direction of the main body 11 or by separating the fixing tube 57 from the pushing member 41 and the gripping member 61. This releases the fixation between the pushing member 41 and the gripping member 61. Next, by operating the pushing member 41, the expansion member 31 expands radially outward, and the tip of the expansion member 31 is fixed distally to the lead 80. Next, the medical device 7 can be pulled toward the proximal end, allowing the lead 80 to be withdrawn from the body.

[0176] The medical device 7 has the fixing tube 57, and therefore the fixing tube 57 can be detachably fixed to the pushing member 41 and the gripping member 61. As a result, when the medical device 7 is not in use, it is possible to prevent the pushing member 41 from accidentally moving toward the distal end, thereby preventing the expansion member 31 from expanding.

[0177] The fixing tube 57 may have a slit 57a extending along the longitudinal direction of the main body 11. The slit 57a may extend from the distal end of the fixing tube 57 toward the proximal end, or from the proximal end toward the distal end. The slit 57a may extend from the distal end to the proximal end of the fixing tube 57. In the fixing tube 57 of the medical device 7, the slit 57a extends from the proximal end toward the distal end to halfway along the longitudinal direction of the fixing tube 57. This allows the fixing tube 57 to be easily removed from the pushing member 41 and the gripping member 61 by tearing and unfolding the cylindrical fixing tube 57 along the longitudinal direction starting from the slit 57a.

[0178] Eighth Embodiment Figure 34 is a schematic diagram showing an eighth embodiment. The medical device 8 generally comprises a main body 18, a pushing member 48, a fixing mechanism 58, a gripping member 61, and a tip fixation portion 21 and an expansion member 31 (not shown). The eighth embodiment differs from the seventh embodiment in that it comprises a main body 18, a pushing member 48, and a fixing mechanism 58. The configurations of the tip fixation portion 21, the expansion member 31, and the gripping member 61 are the same as those of the first embodiment. Therefore, the same components are designated by the same reference numerals, and detailed description thereof will be omitted.

[0179] 34 , the main body 18 is an elongated member. The pushing member 48 is a member that is movable along the longitudinal direction of the main body 18 and pushes the base end of the expansion member 31 toward the distal end. The pushing member 48 is formed of a substantially cylindrical member.

[0180] The fixing mechanism 58 is provided on the pushing member 48 and the main body 18 and is formed by a screw mechanism (hereinafter also referred to as "screw mechanism 58") that fixes the pushing member 48 and the main body 18 together. The pushing member 48 and the main body 18 are releasably fixed by the screw mechanism 58. The screw mechanism 58 is formed by a male thread portion and a female thread portion. The male thread portion may be formed on the pushing member and the female thread portion may be formed on the main body. The male thread portion may be formed on the main body and the female thread portion may be formed on the pushing member. In the medical device 8, the male thread portion 18a is formed on the outer periphery of the main body 18, and the female thread portion 48a is formed on the proximal end of the pushing member 48.

[0181] The male thread portion 18a and the female thread portion 48a of the screw mechanism 58 may be formed integrally with or separately from the pushing member 48 and the main body 18. If formed separately, the material forming the screw mechanism 58 may be the same as or different from the material of the pushing member 48 and the main body 18.

[0182] When using the medical device 8, for example, immediately before expanding the expansion member 31, the male threaded portion 18a and the female threaded portion 48a are separated while rotating the pushing member 48 relative to the main body 18. This releases the fixation between the pushing member 48 and the main body 18. Next, by operating the pushing member 48, the expansion member 31 expands radially outward, and the tip of the expansion member 31 is fixed distally to the lead 80. Next, the medical device 8 can be pulled toward the proximal end, allowing the lead 80 to be withdrawn from the body.

[0183] The medical device 8 has a screw mechanism 58, which allows the pushing member 48 to be releasably fixed to the main body 18. As a result, when the medical device 8 is not in use, it is possible to prevent the pushing member 48 from accidentally moving toward the distal end, causing the expansion member 31 to expand.

[0184] 35 and 36 are schematic diagrams showing a ninth embodiment. A medical device 1100 generally comprises a main body 11, a tip fixation section 21, an expansion member 1130, a pushing member 41, and a fixing mechanism 51 and a gripping member 61 (not shown). The ninth embodiment differs from the first embodiment in that it comprises the expansion member 1130. The configurations of the main body 11, tip fixation section 21, pushing member 41, fixing mechanism 51, and gripping member 61 are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0185] 35 , the expansion member 1130 is a member that covers the outer periphery of the main body 11 and is expandable radially outward. The expansion member 1130 of the medical device 1100 has a basket portion 1131 and a connecting portion 1132.

[0186] The basket portion 1131 is provided at the distal end of the expansion member 1130 and is a portion that can expand radially outward. The distal end of the basket portion 1131 is joined to the distal fixation portion 21, and the proximal end is joined to the connecting portion 1132. The basket portion 1131 can be formed, for example, by a plurality of basket wires w7 extending along the longitudinal direction of the main body 11. In the medical device 1100, two basket wires w7 are provided that face each other across the main body 11. Each of the basket wires w7 extends in a substantially straight line along the longitudinal direction of the main body 11. When the proximal ends of the basket wires w7 are pushed toward the distal side, each of the basket wires w7 expands in an arc shape radially outward.

[0187] The basket wires w7 are made of a deformable material, such as a Ni—Ti alloy.

[0188] The connecting portion 1132 is a portion that is joined to the base end of the basket portion 1131 and extends toward the base end. The connecting portion 1132 can be formed, for example, by tightly winding the wires w8 in a spiral shape around the outer periphery of the main body 11. The wires w8 may be joined to each other along the longitudinal direction. The pushing member 41 pushes the base end of the connecting portion 1132, moving the base end of the basket portion 1131 together with the connecting portion 1132 toward the tip end, causing the basket portion 1131 to expand in an arc outward in the radial direction.

[0189] Examples of materials for the wire w8 include stainless steel alloys and Co-Cr alloys.

[0190] When using the medical device 1100, the pushing member 41 is moved toward the distal end to push out the connecting portion 1132. As shown in FIG. 36 , the basket wire w7, whose distal end is joined to the distal fixation portion 21, is pushed by the connecting portion 1132 and deforms into an arc that convex radially outward, causing the basket portion 1131 to expand. The expanded basket portion 1131 abuts against the lumen wall 80a of the lead 80. This fixes the basket portion 1131, located at the distal end of the expansion member 1130, distally to the lead 80. Next, the medical device 1100 can be pulled toward the proximal end to withdraw the lead 80 from the body.

[0191] As described above, the medical device 1100 has the above-described configuration, and therefore the basket portion 1131 can be fixed distal to the lead 80. As a result, for example, when removing the hollow lead 80 from the body, the hollow lead 80 implanted in the body can be smoothly removed.

[0192] 37 and 38 are schematic diagrams showing a tenth embodiment. As shown in Fig. 37, a medical device 1200 generally includes a hollow shaft 1210, an expansion member 1230, and a pushing member 1240.

[0193] The hollow shaft 1210 is formed of a hollow shaft having an inner cavity 1210h. The tip of the hollow shaft 1210 is closed with a cap 1211. The tip of the hollow shaft 1210 has a plurality of openings 1210a that penetrate the side surface of the hollow shaft 1210 and connect the inner cavity 1210h of the hollow shaft 1210 to the outside. In the medical device 1200, two openings 1210a are provided on opposite side surfaces of the hollow shaft 1210.

[0194] In this embodiment, the expansion member 1230 is formed of an expansion wire (hereinafter also referred to as the "expansion wire 1230"). The expansion wire 1230 is a member that is self-expandable radially outward. The entire expansion wire 1230 is housed in the lumen 1210h of the hollow shaft 1210. When the expansion wire 1230 is pushed distally by the pushing member 1240, the distal end of the expansion wire 1230 protrudes outside the hollow shaft 1210 through the opening 1210a and expands radially outward.

[0195] The expansion wire 1230 is formed of a self-expandable wire w9, which may be made of, for example, a Ni—Ti alloy.

[0196] The pushing member 1240 is a member that can move along the longitudinal direction of the hollow shaft 1210. The distal end of the pushing member 1240 is inserted into the inner cavity 1210h of the hollow shaft 1210. The distal end of the pushing member 1240 is joined to the proximal end of the expansion wire 1230. The distal end of the pushing member 1240 can be formed, for example, by a solid shaft. The proximal end of the pushing member 1240 is located closer to the proximal end than the proximal end of the hollow shaft 1210. The proximal end of the pushing member 1240 is the portion where the operator grasps the pushing member 1240. When the operator grasps the pushing member 1240 and moves toward the distal end, the expansion wire 1230 is pushed toward the distal end.

[0197] When using the medical device 1200, the operator pushes the pushing member 1240 toward the distal end to push out the expansion wire 1230. As shown in FIG. 38 , when the distal end of the expansion wire 1230 reaches the opening 1210a, the distal end of the self-expandable expansion wire 1230 protrudes through the opening 1210a and out of the hollow shaft 1210. The distal end of the expansion wire 1230 then further expands radially outward and abuts against the lumen wall 80a of the lead 80. This fixes the distal end of the expansion wire 1230 distally of the lead 80. The medical device 1200 can then be pulled toward the proximal end to withdraw the lead 80 from the body.

[0198] As described above, the medical device 1200 has the above-described configuration, and therefore the tip of the extension wire 1230 can be fixed distal to the lead 80. As a result, for example, when removing the hollow lead 80 from the body, the hollow lead 80 implanted in the body can be smoothly removed.

[0199] 39 and 40 are schematic diagrams showing an eleventh embodiment. As shown in Fig. 39, a medical device 1300 generally includes a hollow shaft 1310 and an expansion member 1330.

[0200] The hollow shaft 1310 is formed of a hollow shaft having a lumen 1310h. The tip of the hollow shaft 1310 is closed with a cap 1311. The tip of the hollow shaft 1310 has an opening 1310a that penetrates the side surface of the hollow shaft 1310 and communicates the lumen 1310h of the hollow shaft 1310 with the inside of the expansion member 1330. The lumen 1310h becomes the expansion lumen L through which the expansion liquid flows.

[0201] The expansion member 1330 is formed of a balloon (hereinafter also referred to as "balloon 1330") that is expandable radially outward. The balloon 1330 is disposed so as to cover the opening 1310a of the hollow shaft 1310. The balloon 1330 is bonded to the outer circumferential surface of the hollow shaft 1310 in a liquid-tight manner. The balloon 1330 is inflated by injecting an expansion liquid into the balloon 1330 through the opening 1310a. For example, physiological saline solution or the like is used as the expansion liquid.

[0202] When using the medical device 1300, the balloon 1330 is inflated using inflation liquid. Specifically, inflation liquid is introduced into the inflation lumen L from the proximal end of the hollow shaft 1310 and introduced into the interior of the balloon 1330 through the opening 1310a. At this time, as shown in FIG. 40 , the pressure of the inflation liquid causes the balloon 1330 to expand radially outward, and the outer circumferential surface of the balloon 1330 abuts against the lumen wall 80a of the lead 80. As a result, the tip of the medical device 1300 is fixed distal to the lead 80. Next, the medical device 1300 can be pulled toward the proximal end to withdraw the lead 80 from the body.

[0203] As described above, the medical device 1300 has the above-described configuration, and therefore the balloon 1330 can be fixed distal to the lead 80. As a result, for example, when removing the hollow lead 80 from the body, the hollow lead 80 implanted in the body can be smoothly removed.

[0204] The present disclosure is not limited to the configurations of the above-described embodiments, but is intended to include all modifications within the meaning and scope of the claims as defined by the claims. Part of the configurations of the above-described embodiments may be deleted or replaced with other configurations, or other configurations may be added to the configurations of the above-described embodiments.

[0205] For example, in the first to ninth embodiments described above, medical devices 1 to 8, 1100 were described in which the expansion members 31, 32, 1130 are compressed along the longitudinal direction using the pushing members 41, 48, thereby expanding the expansion members 31, 32, 35 radially outward. The expansion members are not particularly limited as long as they cover the outer periphery of the main body and are expandable radially outward. For example, the medical device may use a self-expandable expansion member.

[0206] In the first to eighth embodiments described above, the expansion members 31, 32, 35 are exemplified as coils 31, 32, 35 each formed by winding four single wires (wires w1) having a circular cross section. The expansion members are not particularly limited as long as they cover the outer periphery of the main body and can be expanded radially outward. The expansion members may be other means than coils. When the expansion members are formed as coils, the shape and number of wires can be determined as appropriate.

Claims

1. A medical device (1, 2, 3, 4, 5, 6, 7, 8) comprising: an elongated main body (11, 14, 18); and an expansion member (31, 32, 35) covering the outer periphery of the main body (11, 14, 18) and expandable radially outward, wherein the expansion member (31, 32, 35) is a coil (31, 32, 35) in which a wire (w1) is wound around the outer periphery of the main body (11, 14, 18), and a maximum width (a1) of the wire (w1) in a first portion (31A, 32A) of the coil (31, 32, 35) is smaller than a maximum width (a2) of the wire (w1) in a second portion (31B, 32B) of the coil (31, 32) located proximal to the first portion (31A, 32A).

2. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 1, wherein the maximum width of the wire (w1) gradually increases from the distal end side to the proximal end side of the coil (31, 32, 35).

3. A medical device (1, 2, 3, 4, 5, 6, 7, 8) as described in claim 1 or claim 2, wherein the pitch (p1) of the wire (w1) in the first portion (31A, 32A) is greater than the pitch (p2) of the wire (w1) in the second portion (31B, 32B).

4. A medical device (1, 2, 3, 4, 6, 7, 8) according to any one of claims 1 to 3, wherein the coil (31, 32) has a third portion (31C, 32C) located closer to the base end than the second portion (31B, 32B), and the third portion (31C, 32C) has at least some of the adjacent wires (w1) fixed together.

5. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to any one of claims 1 to 4, wherein the pitch of the wire (w1) gradually decreases from the distal end to the proximal end of the coil (31, 32, 35).

6. A medical device (2, 4) according to any one of claims 1 to 5, wherein the coil (32) has a fourth portion (32D) located distally of the first portion (32A), and the fourth portion (32D) is fixed to the main body (11, 14) by a solder material containing gold.

7. A medical device (3) according to any one of claims 1 to 6, having an X-ray opaque marker (35) on the distal side of the first portion (31A, 32A).

8. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to any one of claims 1 to 7, comprising a pushing member (41, 44, 48) that is movable along the longitudinal direction of the main body (11, 14, 18) and pushes the base end of the expansion member (31, 32, 35) toward the distal end, the pushing member (41, 44, 48) being a tubular body (41, 44, 48) that covers the outer periphery of the main body (11, 14, 18), and the maximum width of the pushing member (41, 44, 48) becoming smaller toward the distal end.

9. The medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 8, wherein the maximum width of the distal end of the pushing member (41, 44, 48) is smaller than the maximum width of the proximal end of the expansion member (31, 32, 35).

10. A medical device (1, 3, 4, 5, 6, 7, 8) comprising: an elongated body (11, 14, 18); and an expansion member (31, 35) covering the outer periphery of the body (11, 14, 18) and expandable radially outward, wherein the distal end of the expansion member (31, 35) begins to expand radially outward before the proximal end of the expansion member (31, 35).

11. A medical device (1, 3, 4, 5, 6, 7, 8) as described in claim 10, wherein when the expansion member (31, 35) is expanded, the maximum width (D1) of the distal end of the expansion member (31, 35) is greater than the maximum width (D3) of the proximal end of the expansion member (31, 35).

12. A medical device (1, 3, 4, 5, 6, 7, 8) according to claim 10 or 11, wherein the expansion force at the distal end of the expansion member (31, 35) is greater than the expansion force at the proximal end of the expansion member (31, 35).

13. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 10 to 12, wherein the stress generated at the distal end of the expansion member (31, 35) due to longitudinal compression of the expansion member (31, 35) is greater than the stress generated at the proximal end of the expansion member (31, 35) due to longitudinal compression of the expansion member (31, 35).

14. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 10 to 13, comprising a pushing member (41, 44, 48) movable along the longitudinal direction of the main body (11, 14, 18) and pushing the base end of the expansion member (31, 35) toward the distal end.

15. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 10 to 14, wherein the expansion member (31, 35) is a coil (31, 35) in which a wire (w1) is wound around the outer periphery of the main body (11, 14, 18).

16. A medical device (1, 3, 4, 5, 6, 7, 8) according to claim 15, wherein the pitch of the wires (w1) at the distal end of the coil (31, 35) is greater than the pitch of the wires (w1) at the proximal end of the coil (31, 35).

17. A medical device (1, 3, 4, 5, 6, 7, 8) as described in claim 15 or claim 16, wherein the maximum width of the wire (w1) at the distal end of the coil (31, 35) is smaller than the maximum width of the wire (w1) at the proximal end of the coil (31, 35).

18. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 10 to 17, which is used to remove a hollow lead (80) from the body, wherein the expansion member (31, 35) is inserted into the lumen of the lead (80), the expansion member (31, 35) expands radially outward, and is fixed to the lead (80).

19. A medical device (1, 3, 4, 5, 6, 7, 8) as described in claim 18, wherein the lead (80) has a first electrode (81) located at the tip of the lead (80) and a second electrode (82) located proximally of the first electrode (81), and when the expansion member (31, 35) is in an expanded state, the outer periphery of the expansion member (31, 35) abuts against the inner periphery of a portion of the lead (80) distal to the second electrode (82).

20. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 10 to 19, wherein the tip of the expansion member (31, 35) is positioned within 10 mm of the tip of the main body (11, 14, 18) towards the base end in the longitudinal direction of the main body (11, 14, 18).

21. A medical device (5) as described in any one of claims 1 to 9 and claims 15 to 17, wherein the outer diameter (D4) of the tip of the coil (35) is smaller than the outer diameter (D5) of the base end of the coil (35).

22. A medical device (1, 3, 4, 5, 6, 7, 8) according to any one of claims 1 to 9 and claims 15 to 17, wherein the wire (w1) has an X-ray opaque portion.

23. A medical device (6, 6A, 6B, 6C) according to any one of claims 1 to 22, comprising a reinforcing body (76, 761, 762, 763) extending along the longitudinal direction of the main body (11) between the outer periphery of the main body (11) and the inner periphery of the expansion member (31).

24. A medical device (6A) according to claim 23, wherein the reinforcement (76) is an inner coil (761) wound with a wire (w5).

25. A medical device (6B) according to claim 23, wherein the reinforcing body (76) is a braided body (762) in which wires (w6) are braided.

26. A medical device (6C) according to claim 23, wherein the reinforcing body (76) is a resin tube (763).

27. A medical device (1) according to any one of claims 1 to 26, wherein the main body (1) is formed of a core shaft (1), the core shaft (1) has a distal core shaft (1A) and a proximal core shaft (1B) joined to the proximal end of the distal core shaft (1A) and extending toward the proximal end, and the bending rigidity of the proximal core shaft (1B) is greater than the bending rigidity of the distal core shaft (1A).

28. A medical device (1) according to claim 27, wherein the distal core shaft (1A) is made of a Ni-Ti alloy and the proximal core shaft (1B) is made of a stainless steel alloy.

29. A medical device (1) as described in claim 27 or claim 28, comprising a pushing member (41) movable along the longitudinal direction of the main body (11) and pushing the base end of the expansion member (31) toward the tip side, the pushing member (41) being a tubular body covering the outer periphery of the main body (11), and the portion (11a) where the tip side core shaft (1A) and the base side core shaft (1B) are joined being covered by the tubular body.

30. A medical device (2, 4) comprising: an elongated main body (11, 14); and an expansion member (32) covering the outer periphery of the main body (11, 14) and expandable radially outward, the expansion member (32) having an expansion portion (321) expandable radially outward and a non-expandable portion (322) located distally of the expansion portion (321) and not expandable radially outward, wherein the distal end of the non-expandable portion (322) and the proximal end of the non-expandable portion (322) are fixed to the main body (11, 14) at joint portions (322a), and the portion of the non-expandable portion (322) between the distal end of the non-expandable portion (322) and the proximal end of the non-expandable portion (322) is a non-joint portion (322b) that is not fixed to the main body (11, 14).

31. A medical device (2, 4) according to claim 30, wherein the bending stiffness of the non-bonded portion (322b) is less than the bending stiffness of either of the bonded portions (322a).

32. A medical device (2, 4) according to claim 30 or claim 31, wherein the expansion member (32) is a coil (32) in which a wire (w1) is wound around the outer periphery of the main body (11, 14).

33. A medical device (2, 4) according to any one of claims 30 to 32, wherein the X-ray transparency of the non-expandable portion (322) is less than the X-ray transparency of the expandable portion (321).

34. A medical device (1, 2, 3, 4, 5, 6, 7, 8) comprising: an elongated body (11, 14, 18); an expansion member (31, 32) covering the outer periphery of the body (11, 14, 18) and expandable radially outward; and a pushing member (41, 44) movable along the longitudinal direction of the body (11, 14, 18) and pushing the base end of the expansion member (31, 32) toward the distal end, wherein the rigidity of the proximal end of the pushing member (41) is greater than the rigidity of the distal end of the pushing member (41, 44).

35. A medical device (1, 2, 3, 4, 5, 6, 7) according to claim 34, wherein the pushing member (41, 44) has a reinforcing coil (411) surrounding the proximal end of the pushing member (41, 44).

36. A medical device (1, 2, 3, 4, 5, 6, 7) according to claim 35, wherein the proximal end of the pushing member (41, 44) is provided with a pushing loop member (412).

37. A medical device (1, 2, 3, 4, 5, 6, 7) according to claim 36, wherein the maximum width (s1) of the push-in loop member (412) is less than the maximum width (s2) of the reinforcing coil (411).

38. A medical device (1, 2, 3, 4, 5, 6, 7) as described in claim 36 or claim 37, wherein the length (s3) of the loop portion (412a, 412am) of the pushing loop member (412, 412m) in the longitudinal direction of the main body (11, 14) is greater than the maximum width (s2) of the reinforcing coil (411).

39. A medical device according to any one of claims 36 to 38, wherein the tip of the pushing loop member (412, 412m) is located radially inside an imaginary cylindrical surface (f) extending from the outer circumferential surface of the reinforcing coil (411).

40. A medical device (1, 2, 3, 4, 5, 6, 7) as described in claim 36, wherein the proximal end of the pushing loop member (412, 412m) is fixed between the outer periphery of the proximal end of the pushing member (41, 44) and the inner periphery of the reinforcing coil (411).

41. The medical device of claim 40, wherein the proximal end of the push-in loop member (412, 412m) has a first end (t1) and a second end (t2), and the first end (t1) and the second end (t2) are spaced apart from each other.

42. A medical device (1, 2, 3, 4, 5, 6, 7, 8) comprising: an elongated body (11, 14, 18); an expansion member (31, 32, 35) covering the outer periphery of the body (11, 14, 18) and expandable radially outward; a pushing member (41, 44, 48) movable along the longitudinal direction of the body (11, 14, 18) and pushing the base end of the expansion member (31, 32, 35) toward the distal end; and a fixing mechanism (51, 57, 58) capable of fixing the body (11, 14, 18) and the pushing member (41, 44, 48).

43. A medical device (1, 2, 3, 4, 5, 6) according to claim 42, wherein the pushing member (41, 44) is a cylindrical body (41, 44) that covers the outer periphery of the main body (11, 14), and the fixing mechanism (51) fixes the main body (11, 14) to the pushing member (41, 44) by engaging the outer periphery of the main body (11, 14) with the inner periphery of the pushing member (41, 44).

44. A medical device (1, 2, 3, 4, 5, 6) according to claim 43, wherein the main body (11, 14) is a core shaft (11, 14), the fixing mechanism (51) has a curved portion (113) formed by curving a portion of the core shaft (11, 14), and the curved portion (113) abuts against the inner circumference of the pushing member (41, 44).

45. A medical device (1, 2, 3, 4, 5, 6) as described in claim 44, wherein the fixing mechanism (51) has a first curved portion (113A) where the core shaft (11, 14) is curved in a first direction, and a second curved portion (113B) where the core shaft (11, 14) is curved in a second direction different from the first direction.

46. ​​A medical device (1, 2, 3, 4, 5, 6) according to claim 45, wherein the fixing mechanism (51) has the first curved portion (113A) and the second curved portion (113B) arranged in a zigzag pattern.

47. A medical device (1, 2, 3, 4, 5, 6) according to any one of claims 42 to 46, wherein the main body (11, 14) has a first marker (511) at a location distal to the tip of the fixing mechanism (51).

48. A medical device (1, 2, 3, 4, 5, 6) according to claim 47, wherein the main body (11, 14) has a second marker (512) at a location proximal to the proximal end of the fixing mechanism (51).

49. A medical device (1, 2, 3, 4, 5, 6) according to claim 48, wherein each of the first marker (511) and the second marker (512) is a metal oxide coating formed on the surface of the body (11, 14).

50. A medical device (1, 2, 3, 4, 5, 6) according to any one of claims 42 to 49, wherein the pushing member (41, 44) has a position marker (413) provided on the outer periphery of the proximal end thereof.

51. A medical device (7) as described in claim 42, comprising a flexible gripping member (61) positioned proximal to the pushing member (41) and connected to the proximal end of the main body (11), wherein the fixing mechanism is a resin fixing tube (57) that covers the outer periphery of the pushing member (41) and the gripping member (61) and fixes the pushing member (41) and the gripping member (61).

52. A medical device (7) according to claim 51, wherein the fixing tube (57) has a notch (57a) extending along the longitudinal direction of the body (11).

53. The medical device (8) according to claim 42, wherein the fixing mechanism is formed by a screw mechanism (58) provided on the pushing member (48) and the body (18) for fixing the pushing member (48) and the body (18) together.

54. A medical device (1, 2, 3, 4, 5, 6, 7, 8) comprising: an elongated main body (11, 14, 18); an expansion member (31, 32, 35) covering the outer periphery of the main body (11, 14, 18) and expandable radially outward; a pushing member (41, 44, 48) movable along the longitudinal direction of the main body (11, 14, 18) and pushing the base end of the expansion member (31, 32, 35) toward the distal end; and a flexible gripping member (61) disposed proximal to the pushing member (41, 44, 48) and connected to the base end of the main body (11, 14, 18), wherein the gripping member (61) is formed by spirally winding a wire (w3).

55. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 54, wherein the longitudinal length of the gripping member (61) is greater than the longitudinal length of the pushing member (41, 44, 48).

56. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 54 or claim 55, wherein the gripping member (61) is tubular, a gripping loop member (611) is provided at the proximal end of the gripping member (61), and the distal end of the gripping loop member (611) is fixed to the inner circumference of the proximal end of the tubular gripping member (61).

57. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 56, wherein the maximum width (b1) of the gripping loop member (611) is less than the maximum width (b2) of the gripping member (61).

58. A medical device (1, 2, 3, 4, 5, 6, 7, 8) described in any one of claims 54 to 57, wherein the wire (w3) forming the gripping member (61) includes a core wire (w31) and a side wire (w32) wound around the core wire (w31).

59. A medical device (4) comprising: an elongated main body (14); and an expansion member (32) covering the outer periphery of the main body (14) and expandable radially outward, the expansion member (32) having an expansion portion (321) expandable radially outward and a non-expandable portion (322) located distally of the expansion portion (321) and not expandable radially outward, wherein the main body (14) is a core shaft (14), and the distal end of the core shaft (14) has a first tapered portion (141A, 141A1, 141A2) whose diameter gradually increases toward the base end, and the first tapered portion (141A, 141A1, 141A2) is located distally of the distal end of the expansion portion (321).

60. A medical device (4) according to claim 59, wherein the outer periphery of the first tapered portion (141A, 141A1, 141A2) is covered with the non-expanding portion (322).

61. A medical device as described in claim 59 or claim 60, wherein the distal end and proximal end of the non-expanding portion (322) are each fixed to the main body (14, 14A1, 14A2) at a joint (322a), and the portion of the non-expanding portion (322) between the distal end and proximal end of the non-expanding portion (322) is a non-joint portion (322b) that is not fixed to the main body (14, 14A1, 14A2), and the outer periphery of the proximal end of the first tapered portion (141A2) is covered by the non-joint portion (322b).

62. A medical device (4) according to any one of claims 59 to 61, wherein the core shaft (14, 14A1, 14A2) has a first straight portion (141B) with a constant outer diameter that extends from the base end of the first tapered portion (141A, 141A1, 141A2) toward the base end, and the outer periphery of the first straight portion (141B) is covered with the expansion portion (321).

63. A medical device (4) according to claim 62, comprising a pushing member (44) movable along the longitudinal direction of the main body (14, 14A1, 14A2) and pushing the base end of the expansion member (32) toward the distal end, wherein the core shaft (14, 14A1, 14A2) has a second tapered portion (141C) located proximally of the base end of the first straight portion (141B) and gradually widening in diameter toward the proximal end, and a second straight portion (141D) having a constant outer diameter and extending from the proximal end of the second tapered portion (141C) toward the proximal end, wherein the outer periphery of the second straight portion (141D) is covered with the pushing member (44).

64. A medical device (1, 2, 3, 4, 5, 6, 7, 8) comprising: an elongated main body (11, 14, 18); and an expansion member (31, 32, 35) covering the outer periphery of the main body (11, 14, 18) and expandable radially outward, wherein at least a portion of the expansion member (31, 32, 35) is plastically deformed when the expansion member (31, 32, 35) is in an expanded state.

65. A medical device (1, 2, 3, 4, 5, 6, 7, 8) according to claim 64, wherein the expansion member (31, 32, 35) is a coil (31, 32, 35) in which a wire (w1) is wound around the outer periphery of the main body (11, 14, 18).

Images