Lesion retrieval devices and atherectomy devices

Abstract

To provide a lesion recovery device capable of suppressing decline of suction efficiency or transport efficiency of a tissue slice.SOLUTION: A lesion recovery device includes a shaft having a long-sized outer shape, a spiral projection projecting spirally from the outer peripheral surface of the shaft, and a cylindrical outer cylindrical tube, which is an outer cylindrical tube storing inside a part on the proximal end side of the shaft provided with the spiral projection. In the spiral projection, a wire having an uneven-shaped surface in a cross section is wound around spirally on the outer peripheral surface of the shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to lesion retrieval devices and atherectomy devices. [Background technology]

[0002] Devices that remove stenotic or occlusive lesions (hereinafter collectively referred to as "lesions") that occur within blood vessels by cutting them are known. When these devices cut the diseased tissue, tissue fragments that constitute the lesion are scattered. The scattered tissue fragments may become lodged in the blood vessel downstream and contribute to the formation of new lesions. For this reason, devices that cut diseased tissue preferably have the function of sucking the tissue fragments into the device and transporting them to the outside of the device.

[0003] Patent Document 1 discloses an atherectomy device that cuts diseased tissue with a tip at the end of a shaft by rotating the shaft, and sucks and transports tissue fragments into a tube that includes the shaft with a screw thread on the outer periphery. Patent Documents 2 to 5 disclose shafts with a wire wound helically on the outer periphery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-164529 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-183125 [Patent Document 3] US Patent Application Publication No. 2016 / 0101262 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-93122 [Patent Document 5] Patent No. 4051292 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the atherectomy device described in Patent Document 1 has a problem in that, depending on the amount or size of the tissue fragments aspirated, the tissue fragments may clog the tube, reducing the efficiency of suction and transport of the tissue fragments. Furthermore, the shafts disclosed in Patent Documents 2 to 5 do not take into consideration the fact that the shaft is rotated to aspirate and transport tissue fragments into a tube that contains the shaft. This problem is common to all devices that remove foreign bodies from biological lumens, such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and aims to provide a lesion retrieval device that can suppress a decrease in the suction efficiency and transportation efficiency of tissue fragments. [Means for solving the problem]

[0007] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0008] (1) One aspect of the present invention provides a lesion retrieval device comprising a shaft having an elongated outer shape, a helical protrusion protruding in a spiral shape from the outer circumferential surface of the shaft, and a cylindrical outer tube that houses a portion of the proximal end of the shaft where the helical protrusion is provided, wherein the helical protrusion has a wire having an uneven surface in cross section wound helically around the outer circumferential surface of the shaft.

[0009] According to this configuration, a helical protrusion is provided on the portion of the shaft housed in the outer tube. Therefore, by rotating the shaft and the helical protrusion, tissue pieces sucked into the outer tube can be transported within the outer tube by the helical protrusion, which functions as an Archimedes screw. Furthermore, according to this configuration, the helical protrusion is a wire having an uneven surface in cross section, which is wound helically around the outer circumferential surface of the shaft. Therefore, the convex portions of the uneven surface of the helical protrusion serve as edges, allowing tissue pieces transported within the outer tube to be shredded. This prevents tissue pieces sucked into the outer tube from clogging, thereby preventing a decrease in the suction efficiency and transport efficiency of the tissue pieces.

[0010] (2) In the lesion retrieval device of the above form, the wire has a configuration in which a base wire having a polygonal or elliptical cross section is twisted spirally, and the twisting direction of the base wire may be different from the winding direction in which the wire is wound around the shaft. According to this configuration, the wire has a base wire having a polygonal or elliptical cross section that is twisted into a spiral shape, which facilitates the realization of an uneven surface shape on the cross section of the wire. Furthermore, by winding such a wire around the outer circumferential surface of the shaft, the helical convex portion is formed, which facilitates the realization of the helical convex portion. Furthermore, according to this configuration, the twisting direction of the base wire is different from the winding direction of the wire around the shaft. Therefore, the helical direction of the helical convex portion and the extension direction of the convex portion on the surface of the helical convex portion both face the proximal end, thereby combining the fluid flow along the helical direction and the fluid flow along the extension direction. As a result, the transport of tissue fragments toward the proximal end of the lesion retrieval device can be facilitated.

[0011] (3) In the lesion retrieval device of the above form, the wire has a configuration in which a base wire having a polygonal or elliptical cross section is twisted spirally, and the twisting direction of the base wire may be the same as the winding direction in which the wire is wound around the shaft. According to this configuration, the wire has a configuration in which a base wire having a polygonal or elliptical cross section is twisted into a spiral shape, which makes it easy to realize an uneven surface shape on the cross section of the wire. Furthermore, by winding such a wire around the outer circumferential surface of the shaft, a spiral convex portion is formed, which makes it easy to realize a spiral convex portion. Furthermore, according to this configuration, the twisting direction of the base wire is the same as the winding direction in which the wire is wound around the shaft. Therefore, the spiral direction in which the spiral convex portion extends faces the base end, and the extension direction of the convex portion on the surface of the spiral convex portion faces the distal end, which makes it easy to generate shear forces between the fluid flowing along the spiral direction and the fluid flowing along the extension direction. This shear force can promote the shredding of tissue fragments.

[0012] (4) In the lesion retrieval device of the above embodiment, the shaft may be a single-filament coil in which one wire is wound in a single filament, or a multi-filament coil in which multiple wires are wound in multiple filaments. According to this configuration, the shaft is a single-strand coil in which one wire is wound in a single strand, or a multi-strand coil in which multiple wires are wound in multiple strands, thereby improving the torque transmission and flexibility of the shaft.

[0013] (5) In the lesion retrieval device of the above aspect, the shaft may have a device lumen inside through which a medical device can be inserted. According to this configuration, the shaft has a device lumen inside through which a medical device can be inserted, and by inserting a delivery guide wire through the device lumen, the lesion retrieval device can be easily delivered to the lesion.

[0014] (6) The lesion retrieval device of the above form may further include a rotation transmission mechanism connected to the shaft and transmitting a rotational force to the shaft, thereby rotating the shaft and the spiral convex portion around the axis. According to this configuration, since a rotation transmission mechanism that rotates the shaft and the spiral convex portion about the axis is provided, the shaft and the spiral convex portion can be easily rotated using this rotation transmission mechanism.

[0015] (7) According to one aspect of the present invention, there is provided an atherectomy device comprising: the lesion retrieval device of the above aspect; and a cutter provided at the distal end of the shaft of the lesion retrieval device, capable of resecting biological tissue. According to this configuration, a cutter capable of cutting biological tissue is provided at the tip of the shaft, so that diseased tissue can be cut efficiently and even hard lesions such as calcified lesions can be cut.

[0016] The present invention can be realized in various forms, for example, in the form of a catheter including a lesion retrieval device or an atherectomy device, a method for manufacturing a lesion retrieval device or an atherectomy device, and the like. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a first embodiment. [Figure 2] 10A and 10B are diagrams illustrating a wire wound in a spiral shape around the outer circumferential surface of a shaft. [Figure 3] FIG. 10 is an explanatory diagram showing an example of diseased tissue removal using a lesion retrieval device. [Figure 4] FIG. 10 is an explanatory diagram illustrating transportation by a spiral convex portion. [Figure 5] FIG. 10 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a second embodiment. [Figure 6] FIG. 10 is an explanatory diagram illustrating transportation by a spiral convex portion. [Figure 7] FIG. 10 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a third embodiment. [Figure 8]FIG. 8 is a cross-sectional view showing a cross section taken along line BB in FIG. 7. [Figure 9] FIG. 10 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a fourth embodiment. [Figure 10] FIG. 10 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a fifth embodiment. [Figure 11] FIG. 13 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a sixth embodiment. [Figure 12] FIG. 13 is an explanatory diagram illustrating the configuration of a lesion recovery device according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] First Embodiment FIG. 1 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1 according to a first embodiment. The lesion retrieval device 1 is a device used to remove diseased tissue, such as a stenotic lesion or an occlusive lesion (hereinafter, collectively referred to simply as a "lesion"), that has occurred in a blood vessel. The lesion retrieval device 1 can be configured as a device for removing diseased tissue (or foreign bodies) that has occurred in a body lumen, such as the coronary artery, other vascular systems such as the heart, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs. The lesion retrieval device 1 includes a shaft 10, an outer tube 20, a distal joint 31, a proximal joint 33, a tip 35, and a motor housing 40.

[0019] For ease of explanation, Figure 1 includes portions in which the relative size ratios of the components are depicted differently from the actual size. Also, some of the components are depicted in an exaggerated manner. Figure 1 also illustrates mutually orthogonal X, Y, and Z axes. The X axis corresponds to the longitudinal direction of the lesion retrieval device 1, the Y axis corresponds to the height direction of the lesion retrieval device 1, and the Z axis corresponds to the width direction of the lesion retrieval device 1. The left side of Figure 1 (-X axis direction) is referred to as the "distal side" of the lesion retrieval device 1 and each component, and the right side of Figure 1 (+X axis direction) is referred to as the "proximal side" of the lesion retrieval device 1 and each component. Of the two ends of the lesion retrieval device 1 and each component in the longitudinal direction (X axis direction), the distal end is referred to as the "distal end," and the proximal end is referred to as the "proximal end." The distal end and its vicinity are referred to as the "distal portion," and the proximal end and its vicinity are referred to as the "proximal end." The distal end is inserted into the living body, and the proximal end is manipulated by a surgeon, such as a physician. These points are also common to Figure 1 and subsequent figures.

[0020] In Fig. 1, the cross section of the outer tube 20 taken along the XY plane is shown by diagonal hatching, and the cross section of the motor housing 40 taken along the XY plane is shown by grid hatching. For ease of explanation, Fig. 1 shows the external appearance of the components of the lesion retrieval device 1 other than the outer tube 20 and the motor housing 40. That is, Fig. 1 shows the lesion retrieval device 1 in a state where the components contained inside the outer tube 20 and the motor housing 40 can be seen from the outside.

[0021] The shaft 10 is a member having an elongated outer shape extending along the longitudinal direction of the lesion retrieval device 1. The shaft 10 is provided inside (inner cavity 1L) the outer tube 20 and the motor housing 40. The shaft 10 is preferably antithrombogenic, flexible, and biocompatible, and can be formed from a resin material or a metal material. Examples of resin materials that can be used include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. Examples of metal materials that can be used include stainless steel such as SUS304, nickel-titanium alloy, and cobalt-chromium alloy. In this embodiment, the shaft 10 is a multi-strand coil in which multiple wires are wound in multiple strands, and is made of stainless steel such as SUS304.

[0022] The shaft 10 has a device lumen 10L inside. As shown by the dashed line in FIG. 1, the device lumen 10L extends along the longitudinal direction (X-axis direction) of the lesion retrieval device 1. A delivery guide wire serving as a medical device can be inserted inside the device lumen 10L. Hereinafter, the delivery guide wire will also be simply referred to as a "guide wire." The outer shape and length of the shaft 10 and the inner diameter of the device lumen 10L can be designed as desired.

[0023] The shaft 10 has a helical protrusion 11 and a large-diameter portion 12. The helical protrusion 11 protrudes helically from the outer peripheral surface 10a of the shaft 10. In the helical protrusion 11, a wire having an uneven surface in cross section is wound helically around the outer peripheral surface 10a of the shaft 10. Hereinafter, the wire wound helically around the outer peripheral surface 10a of the shaft 10 will be referred to as wound wire 11W. In this embodiment, the helical protrusion 11 is formed by winding the wound wire 11W around the outer peripheral surface 10a of the shaft 10 in a Z-winding direction. The large-diameter portion 12 is a portion on the base end side of the shaft 10 that has a larger diameter than other portions.

[0024] The sheath tube 20 is a cylindrical member that houses a portion of the proximal end of the shaft 10, on which the helical protrusion 11 is provided. In other words, the distal end of the shaft 10, on which the helical protrusion 11 is provided, is exposed from the sheath tube 20. The helical protrusion 11 provided on the portion of the shaft 10 exposed from the sheath tube 20 promotes the suction of fluid from the surroundings at the distal end of the lesion retrieval device 1 into the lesion retrieval device 1 when the shaft 10 and the helical protrusion 11 rotate. An opening 22 is formed at the distal end of the sheath tube 20. The opening 22 is formed around the shaft 10 when the lesion retrieval device 1 is viewed from the distal end. In this embodiment, the sheath tube 20 is formed by heat shrinking a cylindrical member made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). The outer tube 20 may be made of FEP (tetrafluoroethylene-hexafluoropropylene copolymer), or may be made of other resin materials that are antithrombogenic, flexible, and biocompatible. The outer tube 20 may also be a resin tube containing a metal braid inside.

[0025] The distal joint 31 is a disk-shaped member and joins the distal end of the shaft 10 to the proximal end of the tip 35. The proximal end of the distal joint 31 is also joined to the distal end of the spiral convex portion 11. The proximal joint 33 is an annular member through which the shaft 10 can be inserted and is fixed to the shaft 10 with the shaft 10 inserted. In this embodiment, the position on the shaft 10 at which the proximal joint 33 is fixed corresponds to the proximal end of the outer tube 20 in the X-axis direction. The distal end of the proximal joint 33 is joined to the proximal end of the spiral convex portion 11. Any bonding agent, such as a metal solder such as silver solder, gold solder, zinc, Sn—Ag alloy, or Au—Sn alloy, or an adhesive such as an epoxy adhesive, can be used to join the distal joint 31 and the proximal joint 33.

[0026] The tip 35 is joined to the distal end of the distal joint 31 and is a component that advances through the biological lumen ahead of the other components. As shown in Fig. 1, the tip 35 has an external shape that tapers in diameter from the proximal end to the distal end to allow the lesion retrieval device 1 to advance smoothly through the biological lumen. When the tip 35 comes into contact with lesioned tissue formed in a blood vessel, the lesioned tissue is cut (see Fig. 3).

[0027] The motor housing 40 is a substantially cylindrical member that houses the packing 43 and the motor 46 and through which the shaft 10 is inserted. An outer tube 20 is joined to the tip of the motor housing 40. The motor housing 40 has a protrusion 41 that protrudes in the +Y-axis direction. An outlet 42 is formed in the protrusion 41. The outlet 42 is an opening for discharging tissue fragments of the lesion tissue that have been sucked into the lesion retrieval device 1 through the opening 22 to the outside of the lesion retrieval device 1 (see FIG. 3).

[0028] The packing 43 is an annular member through which the shaft 10 can be inserted, and is made of a material such as rubber or various elastomers. The packing 43 is fitted into the distal end reduced diameter portion 44, which has a reduced diameter due to a protrusion of the inner wall in the internal space of the motor housing 40, and seals the distal end reduced diameter portion 44 to prevent fluid from leaking from the distal end reduced diameter portion 44 to the base end side.

[0029] The proximal reduced diameter section 45 is a reduced diameter section formed closer to the proximal end than the distal reduced diameter section 44. By disposing the large diameter section 12 between the distal reduced diameter section 44 and the proximal reduced diameter section 45, movement of the shaft 10 in the longitudinal direction (X-axis direction) of the lesion retrieval device 1 is suppressed.

[0030] The motor 46 is a rotation transmission mechanism that is connected to the shaft 10 and transmits a rotational force to the shaft 10, thereby rotating the shaft 10 and the spiral convex portion 11 about the axis. In this embodiment, the motor 46 transmits the rotational force directly to the shaft 10. The motor 46 may also transmit the rotational force indirectly to the shaft 10 via another member. Alternatively, instead of using the motor 46, the rotational force to the shaft 10 may be transmitted by manually rotating a handle.

[0031] FIG. 2 is a diagram illustrating a wire (wound wire 11W) wound in a spiral shape around the outer circumferential surface 10a of the shaft 10 as the spiral protrusion 11. The base wire 11pa shown in FIG. 2(A) is a wire having a rectangular cross section. Specifically, the base wire 11pa is a wire formed by rolling a round wire having a circular cross section, and therefore the four corners of the rectangular cross section are rounded. The wound wire 11W has a configuration in which the base wire 11pa is twisted in a spiral shape. In this embodiment, the base wire 11pa is twisted in an S-winding direction. The spiral protrusion 11 is formed by winding the spirally twisted base wire 11pa in a spiral shape around the outer circumferential surface 10a of the shaft 10. As described above, in this embodiment, the spiral convex portion 11 is wound around the shaft 10 in a Z-winding direction, and therefore the twisting direction of the base wire 11pa is different from the winding direction in which the wound wire material 11W is wound around the shaft 10.

[0032] The base wire 11pb shown in FIG. 2(B) is a wire having an elliptical cross section. The wound wire 11W may have a configuration in which the base wire 11pb is twisted spirally. It is preferable that the cross section of the base wire include an angular portion. The angular portion in the cross section of the base wire becomes a convex portion on the surface of the wound wire 11W when the base wire is twisted. This is because, when the base wire is twisted, it is easily stretched in the twisting direction and becomes sharp. Such a sharp convex portion contributes to shredding of tissue fragments sucked into the outer tube 20 through the opening 22.

[0033] Fig. 3 is an explanatory diagram showing an example of diseased tissue removal using the lesion recovery device 1 of this embodiment. Fig. 3 shows a blood vessel 200 as an example of a biological lumen, and diseased tissue 210 as an example of the diseased tissue. A lesion blocked by the diseased tissue 210 has formed in the blood vessel 200 shown in Fig. 3.

[0034] When removing diseased tissue using the lesion retrieval device 1, the surgeon first delivers the guidewire GW so that the tip of the guidewire GW is positioned distal to the diseased tissue 210. Next, the surgeon inserts the guidewire GW into the device lumen 10L from the distal side of the device lumen 10L with the proximal end of the guidewire GW leading. After inserting the guidewire GW, the surgeon pushes the lesion retrieval device 1 along the guidewire GW and delivers the lesion retrieval device 1 until the tip 35 reaches the position of the diseased tissue 210.

[0035] After the lesion retrieval device 1 reaches the location of the lesioned tissue 210, the surgeon operates the motor 46 to rotate the shaft 10 and the spiral protrusion 11. When the tip 35, which is rotating together with the shaft 10, is pressed against the lesioned tissue 210, the lesioned tissue 210 is cut and tissue fragments CP are scattered. Furthermore, when the spiral protrusion 11 exposed from the outer tube 20 is pressed against the lesioned tissue 210 while rotating, the lesioned tissue 210 is cut and tissue fragments CP are scattered. While the shaft 10 and the spiral protrusion 11 are rotating, the distance between the lesioned tissue 210 and the lesion retrieval device 1 is increased or decreased as needed. The tissue fragments CP are sucked into the outer tube 20 through the opening 22 by the rotation of the spiral protrusion 11, and then transported toward the proximal end of the lesion retrieval device 1 by the spiral protrusion 11, which functions as an Archimedes screw. The tissue piece CP being transported is chopped by the convex portions that become the edges of the uneven surface of the spiral convex portion 11. The tissue piece CP that is transported while being chopped in this way is discharged to the outside of the lesion retrieval device 1 through the discharge port 42. In FIG. 3, a suction unit 50 is connected to the discharge port 42, and the tissue piece CP that reaches the discharge port 42 is sucked into the suction unit 50.

[0036] FIG. 4 is an explanatory diagram illustrating transportation by the spiral convex portion 11. As described above, in the lesion retrieval device 1, the spiral convex portion 11 is formed by winding the wound wire material 11W, which is configured by twisting the base wire material 11pa in an S-winding direction, around the shaft 10 in a Z-winding direction. By forming the spiral convex portion 11 in this manner, the spiral direction SD1 in which the spiral convex portion 11 extends and the extension direction TS1 in which the convex-shaped portion on the surface of the spiral convex portion 11 extends both face the proximal end (+X-axis direction). As a result, when the spiral convex portion 11 rotates, the fluid flow along the spiral direction SD1 is combined with the fluid flow along the extension direction TS1, thereby facilitating suction of tissue fragments toward the proximal end.

[0037] As described above, according to the lesion retrieval device 1 of the first embodiment, the portion of the shaft 10 housed in the outer tube 20 is provided with the helical protrusion 11. Therefore, by rotating the shaft 10 and the helical protrusion 11, tissue fragments sucked into the outer tube 20 can be transported by the helical protrusion 11, which functions as an Archimedes screw, within the outer tube 20. Furthermore, according to this configuration, in the helical protrusion 11, a wound wire material 11W having an uneven surface in cross section is wound helically around the outer peripheral surface 10a of the shaft 10. Therefore, the convex portions of the uneven surface of the helical protrusion 11 serve as edges, allowing tissue fragments transported within the outer tube 20 to be shredded. Therefore, clogging of the sucked tissue fragments within the outer tube 20 can be prevented, thereby preventing a decrease in the suction efficiency and transport efficiency of the tissue fragments.

[0038] Furthermore, according to the lesion retrieval device 1 of the first embodiment, the wound wire 11W has a configuration in which a base wire 11pa having a rectangular cross section is twisted spirally, thereby easily realizing an uneven surface shape on the cross section of the wound wire 11W. Furthermore, the wound wire 11W is wound around the outer peripheral surface 10a of the shaft 10 to form the spiral convex portion 11, thereby easily realizing the spiral convex portion 11. Furthermore, with this configuration, the twisting direction of the base wire 11pa differs from the winding direction in which the wound wire 11W is wound around the shaft 10. Therefore, the spiral direction SD1 in which the spiral convex portion 11 extends and the extension direction TS1 in which the convex portion on the surface of the spiral convex portion 11 extends both face the proximal end, and therefore the fluid flow along the spiral direction SD1 and the fluid flow along the extension direction TS1 are combined. As a result, the transport of tissue fragments toward the proximal end of the lesion retrieval device 1 can be promoted.

[0039] Furthermore, according to the lesion retrieval device 1 of the first embodiment, the shaft 10 is a multi-thread coil in which a plurality of wires are wound in multiple strands, and therefore the torque transmission and flexibility of the shaft 10 can be improved.

[0040] Furthermore, according to the first embodiment of the lesion retrieval device 1, the shaft 10 has a device lumen 10L inside through which a medical device can be inserted, so that the lesion retrieval device 1 can be easily delivered to the lesion by inserting a delivery guide wire through the device lumen 10L.

[0041] Furthermore, according to the first embodiment of the lesion recovery device 1, a motor 46 is provided as a rotation transmission mechanism for rotating the shaft 10 and the spiral convex portion 11 around the axis, and therefore the shaft 10 and the spiral convex portion 11 can be easily rotated using this rotation transmission mechanism.

[0042] Second Embodiment 5 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1A according to a second embodiment. The lesion retrieval device 1A according to the second embodiment has the same configuration as the lesion retrieval device 1 according to the first embodiment, except that the lesion retrieval device 1A according to the second embodiment has a spiral convex portion 11a instead of the spiral convex portion 11 according to the first embodiment.

[0043] The spiral convex portion 11a is formed by winding a spirally twisted base wire 11pa (wound wire 11Wa) in a Z-winding direction around the outer peripheral surface 10a of the shaft 10, similar to the spiral convex portion 11 of the first embodiment. On the other hand, in the spiral convex portion 11a, unlike the spiral convex portion 11 of the first embodiment, the base wire 11pa (wound wire 11Wa) is twisted in a Z-winding direction. Therefore, in the second embodiment, the twisting direction of the base wire 11pa is the same as the winding direction in which the wound wire 11Wa is wound around the shaft 10.

[0044] FIG. 6 is an explanatory diagram illustrating transportation by the spiral convex portion 11a. As described above, in the lesion retrieval device 1A, the wound wire material 11Wa, which is configured by twisting the base wire material 11pa in a Z-winding direction, is wound around the shaft 10 in a Z-winding direction to form the spiral convex portion 11a. Because the spiral convex portion 11a is formed in this manner, the spiral direction SD2 in which the spiral convex portion 11a extends faces the base end (+X-axis direction), and the extension direction of the convex portion on the surface of the spiral convex portion 11a faces the distal end (-X-axis direction). As a result, when the spiral convex portion 11a rotates, shear force is likely to be generated between the fluid flowing along the spiral direction SD2 and the fluid flowing along the extension direction TS2. This shear force contributes to the shredding of tissue fragments, in addition to the convex portion that forms the edge on the surface of the spiral convex portion 11, thereby facilitating the shredding of the tissue fragments.

[0045] The lesion retrieval device 1A of the second embodiment described above can also achieve the same effects as those of the first embodiment. Furthermore, with the lesion retrieval device 1A of the second embodiment, as described above, shear force is likely to be generated between the fluid flowing along the spiral direction SD2 and the fluid flowing along the extension direction TS2, which can promote the shredding of tissue pieces.

[0046] Third Embodiment Figure 7 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1B of a third embodiment. Figure 8 is a cross-sectional view showing a cross section taken along line B-B in Figure 7. The lesion retrieval device 1B of the third embodiment has the same configuration as the lesion retrieval device 1 of the first embodiment, except that it includes a cutter assembly 35b instead of the tip 35 of the first embodiment. The lesion retrieval device 1B including the cutter assembly 35b corresponds to an atherectomy device.

[0047] The cutter assembly 35b is provided at the distal end of the shaft 10 via the distal joint 31. The cutter assembly 35b is a member having an external shape that tapers in diameter from the proximal end to the distal end. The cutter assembly 35b has a circumferential opening 36b and a proximal opening 37b, and houses a cutter 38b therein that can cut biological tissue. The circumferential opening 36b is an opening provided on the circumferential surface of the cutter assembly 35b. The proximal opening 37b is an opening provided around the distal joint 31 and facing the proximal end (see FIG. 8). The cutter assembly 35b rotates as the shaft 10 rotates. In the third embodiment, when removing diseased tissue formed in a blood vessel, the cutter assembly 35b is pressed against the diseased tissue while the shaft 10 is rotating. At this time, the diseased tissue (or tissue fragments scattered from the diseased tissue) that has entered cutter assembly 35b through peripheral opening 36b is shredded by cutter 38b and then discharged to the outside of cutter assembly 35b through proximal opening 37b. The tissue fragments of the diseased tissue discharged from proximal opening 37b are sucked into outer tube 20 through opening 22 by the rotation of spiral convex portion 11.

[0048] The lesion retrieval device 1B of the third embodiment as described above can also achieve the same effects as the first embodiment. Furthermore, according to the lesion retrieval device 1B of the third embodiment, the cutter 38b capable of cutting biological tissue is provided at the distal end of the shaft 10, so that lesion tissue can be efficiently cut, even for hard lesions such as calcified lesions. Furthermore, if the lesion tissue formed in a blood vessel is hard, the lesion tissue is cut into small pieces by the cutter 38b and then aspirated into the outer tube 20, which prevents a decrease in suction efficiency and transportation efficiency when removing hard lesion tissue.

[0049] <Fourth embodiment> 9 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1C of the fourth embodiment. The lesion retrieval device 1C of the fourth embodiment has the same configuration as the lesion retrieval device 1 of the first embodiment, except that it has an outer tube 20c instead of the outer tube 20 of the first embodiment and a distal joint 31c instead of the distal joint 31 of the first embodiment. The outer tube 20c has openings 22c and 24c instead of opening 22.

[0050] The opening 22c is formed on the outer peripheral surface of the outer tube 20c along the longitudinal direction (X-axis direction) of the lesion retrieval device 1. The opening 22c is an opening for sucking tissue fragments into the outer tube 20c when the spiral convex portion 11 rotates. In FIG. 9, the opening 22c is formed in the +Y-axis direction, but the opening 22c may be formed at any position on the outer peripheral surface of the outer tube 20c, and two or more openings may be formed.

[0051] The opening 24c is formed at the tip of the outer tube 20c. The opening 24c is formed at a position where the device lumen 10L extends toward the tip side (negative X-axis direction side) of the shaft 10. The opening 24c is used as an entrance when a guidewire is inserted into the device lumen 10L when removing diseased tissue.

[0052] The distal joint 31c is a hemispherical member and is joined to the distal end of the shaft 10. The base end of the distal joint 31c is joined to the distal end of the spiral convex portion 11. In the fourth embodiment, when removing lesion tissue formed in a blood vessel, the distal end of the outer tube 20c is pressed against the lesion tissue 210 to cut the lesion tissue 210, and scattered tissue pieces are sucked into the lesion retrieval device 1 through the opening 22c.

[0053] The lesion retrieval device 1C of the fourth embodiment can also achieve the same effects as those of the first embodiment. Furthermore, according to the lesion retrieval device 1C of the fourth embodiment, the opening 22c is formed on the outer peripheral surface of the outer cylindrical tube 20c along the longitudinal direction (X-axis direction) of the lesion retrieval device 1. Therefore, the opening 22c can be made larger than when an opening is formed at the distal end of the outer cylindrical tube 20c. The larger the opening 22c, the easier it is to suck tissue pieces into the lesion retrieval device 1C, thereby improving the efficiency of suction of tissue pieces.

[0054] Fifth Embodiment 10 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1D according to a fifth embodiment. The lesion retrieval device 1D according to the fifth embodiment has the same configuration as the lesion retrieval device 1 according to the first embodiment, except that it has a proximal joint 33d instead of the proximal joint 33 according to the first embodiment and does not have the packing 43 according to the first embodiment.

[0055] The base-end joint 33d is an annular member through which the shaft 10 can be inserted, and is joined to the base end of the spiral convex portion 11. With the shaft 10 inserted, the base-end joint 33d is fixed at a position on the shaft 10 that corresponds to the base end BS of the protrusion 41 in the X-axis direction. The base-end joint 33d cannot be fitted inside the motor housing 40 because it rotates with the rotation of the shaft 10, but it is preferable that the cross section in the YZ plane be large so as to suppress the flow of fluid toward the base end side.

[0056] The lesion retrieval device 1D of the fifth embodiment can also achieve the same effects as the first embodiment. Furthermore, since the lesion retrieval device 1D of the fifth embodiment includes the proximal joint 33d, it can suppress the flow of fluid toward the proximal end without including a packing. Of course, a packing may be fitted in the distal reduced diameter section 44 of the lesion retrieval device 1D.

[0057] Sixth Embodiment 11 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1E of the sixth embodiment. The lesion retrieval device 1E of the sixth embodiment has the same configuration as the lesion retrieval device 1 of the first embodiment, except that it includes an outer tube 20e instead of the outer tube 20 of the first embodiment. The outer tube 20e is formed with an expanded diameter section 24e. The expanded diameter section 24e is formed at the tip of the outer tube 20e, and is a section where the diameter of the outer tube 20e expands toward the tip.

[0058] The lesion retrieval device 1E of the sixth embodiment can also achieve the same effects as the first embodiment. Furthermore, according to the lesion retrieval device 1E of the sixth embodiment, the expanded diameter section 24e is formed in the outer cylindrical tube 20e, so that the opening 22 formed at the tip of the outer cylindrical tube 20e can be made larger. The larger the opening 22, the higher the possibility that the tissue fragment will be sucked into the lesion retrieval device 1, and therefore the efficiency of suction of the tissue fragment into the lesion retrieval device 1 can be improved.

[0059] Seventh Embodiment 12 is an explanatory diagram illustrating the configuration of a lesion retrieval device 1F of the seventh embodiment. The lesion retrieval device 1F of the seventh embodiment has the same configuration as the lesion retrieval device 1 of the first embodiment, except that it includes an outer tube 20f instead of the outer tube 20 of the first embodiment. A plurality of openings 26f are formed in the outer circumferential surface of the outer tube 20, and are smaller than the openings 22.

[0060] The lesion retrieval device 1F of the seventh embodiment can also achieve the same effects as those of the first embodiment. Furthermore, according to the lesion retrieval device 1F of the seventh embodiment, the outer tube 20 has multiple openings 26f. Tissue pieces sucked into the outer tube 20 through the openings 22 are sequentially shredded by the spiral convex portion 11 as they move toward the proximal end. If the opening area of ​​the openings 26f is relatively small, the tissue pieces cannot pass through the openings 26f, and the rotation of the spiral convex portion 11 introduces blood into the outer tube 20 through the openings 26f due to the rotation of the spiral convex portion 11. Because tissue pieces have a high viscosity, their accumulation inside the outer tube 20 tends to increase the viscosity of the fluid flowing through the outer tube 20. However, the introduced blood can reduce the viscosity of the fluid. Therefore, if the opening area of ​​the openings 26f is relatively small, a decrease in the efficiency of tissue transport can be suppressed.

[0061] On the other hand, when the opening area of ​​opening 26f is relatively large, opening 26f, like opening 22, can serve as an entrance for sucking tissue fragments scattered into the blood vessel when the diseased tissue is cut away into the outer tube 20. That is, when the spiral convex portion 11 is rotating, it becomes possible to suck tissue fragments into the outer tube 20 from opening 26f in addition to opening 22. Therefore, when the opening area of ​​opening 26f is made relatively large, it is possible to improve the efficiency of collecting tissue fragments scattered into the blood vessel.

[0062] <Modification of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0063] [Variation 1] In the first to seventh embodiments described above, the configurations of the lesion retrieval devices 1, 1A to 1F are illustrated. However, various modifications are possible to the configuration of the baseline material. For example, the baseline material is not limited to having a rectangular cross section, and may have a polygonal cross section. Polygonal shapes include a triangle, pentagon, hexagon, and the like. As described above, the angular portions in the cross section of the baseline material are portions that become convex on the surface of the wound wire when the baseline material is twisted. When the baseline material is twisted, these portions are stretched in the twisting direction, becoming sharper, which contributes to the shredding of tissue fragments.

[0064] For example, the shaft may be a single-strand coil in which a single wire is wound. Alternatively, the shaft may be a hollow rod-shaped member instead of a coil. Alternatively, the shaft may be a solid member instead of a hollow member, or a metal tube such as a hypotube. Since a solid member or hypotube used for the shaft tends to have high rigidity, it is preferable to adjust the rigidity by providing a weakened portion, for example, by slitting it with a laser. Alternatively, the outer tube may be a cylindrical member formed of a tightly wound coil of a single wire or a tightly wound coil in which multiple wires are spirally wound, or a metal tube such as a hypotube. The motor may be omitted, and instead, a handle may be provided that can manually rotate the shaft.

[0065] For example, the winding pitch of the spiral convex portion does not have to be constant as in the lesion retrieval devices 1, 1A-1F shown in the figures, and may be different between the distal end and the proximal end of the shaft. As an example, the winding pitch may be increased at the distal end of the shaft to increase the suction efficiency of tissue fragments, and decreased at the proximal end of the shaft to increase the chance of contact between the convex edges on the surface of the spiral convex portion and the tissue fragments. Alternatively, the winding pitch may be decreased at the distal end of the shaft and increased at the proximal end of the shaft.

[0066] For example, the spiral convex portion may be formed by winding a wound wire, which is a base wire twisted in a Z-winding direction, around the shaft in an S-winding direction. Even in this configuration, the transport of tissue fragments toward the proximal end can be promoted.

[0067] For example, the helical convex portion may be formed by winding a wound wire, which is a base wire twisted in an S-winding direction, around the shaft in an S-winding direction. Even in this form, the shredding of tissue fragments can be facilitated.

[0068] For example, in the spiral convex portion, the directional relationship between the twisting direction of the base wire and the winding direction of the wound wire around the shaft does not have to be constant as in the illustrated lesion retrieval devices 1, 1A-1F, and may be different between the distal end and the proximal end of the shaft. Here, the directional relationship refers to a relationship in which the twisting direction and the winding direction are different, or the twisting direction and the winding direction are the same. For example, the harder the lesion tissue targeted by the lesion retrieval device, the greater the proportion of the portion of the spiral convex portion in which the twisting direction and the winding direction are the same. This is because such portions promote the shredding of tissue fragments. Furthermore, in a lesion retrieval device targeted at lesion tissue where a large amount of tissue fragments is expected to scatter, the greater the proportion of the portion of the spiral convex portion in which the twisting direction and the winding direction are different. This is because such portions promote the transport of tissue fragments toward the proximal end.

[0069] For example, the uneven surface shape in the cross section of the wound wire material may not be formed by twisting the base wire material spirally, but may be formed, for example, by press processing using a mold to form an uneven shape on the circumferential surface of the wire material.

[0070] [Variation 2] The configurations of the lesion retrieval devices 1, 1A to 1F of the first to seventh embodiments and the configurations of the first modified example may be combined as appropriate. For example, the lesion retrieval device 1B of the third embodiment may employ the proximal joint 33d described in the fifth embodiment and omit the packing 43, or may employ the expanded diameter section 24e described in the sixth embodiment, or may employ the multiple openings 26f described in the seventh embodiment. Furthermore, the lesion retrieval device 1C of the fourth embodiment may employ the proximal joint 33d described in the fifth embodiment and omit the packing 43. Furthermore, the lesion retrieval device 1D of the fifth embodiment may employ the expanded diameter section 24e described in the sixth embodiment or may employ the multiple openings 26f described in the seventh embodiment. Furthermore, the lesion retrieval device 1E of the sixth embodiment may employ the multiple openings 26f described in the seventh embodiment. Furthermore, the lesion retrieval device 1F of the seventh embodiment may employ the cutter assembly 35b described in the third embodiment or may employ the expanded diameter section 24e described in the sixth embodiment.

[0071] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0072] 1, 1A~1F...Lesion retrieval device 10...Shaft 10L...Device lumens 11pa,11pb…Base wire material 11, 11a...spiral convex portion 11W, 11Wa...wound wire material 12...Large diameter part 20...Outer tube 22…Aperture 22c…Aperture 24c…Aperture 24e...Expanded diameter part 26f…Aperture 31,31c...Tip side joint part 33,33d,33f…Proximal joint part 35...Chips 35b...Cutter assembly 36b…peripheral opening 37b…Proximal opening 38b...Cutter 40...Motor housing 41...Protruding part 42…Discharge port 43...Gasket 44...Tip-side reduced diameter section 45…Proximal side reduced diameter part 46...Motor 50…Suction part

Claims

1. 1. A lesion retrieval device comprising: a shaft having an elongated outer shape; a spiral protrusion protruding in a spiral shape from the outer circumferential surface of the shaft; a cylindrical outer tube that accommodates a portion of the base end side of the shaft on which the spiral convex portion is provided; Equipped with In the spiral convex portion, a wire having an uneven surface in cross section is wound spirally around the outer circumferential surface of the shaft, The lesion retrieval device has a configuration in which the wire has a base wire having a polygonal or elliptical cross section twisted in a spiral shape.

2. 10. The lesion retrieval device of claim 1, A lesion retrieval device, wherein the twist direction of the base wire is different from the winding direction in which the wire is wound around the shaft.

3. 10. The lesion retrieval device of claim 1, A lesion retrieval device, wherein the twist direction of the base wire is the same as the winding direction in which the wire is wound around the shaft.

4. 4. The lesion retrieval device according to claim 1, A lesion retrieval device, wherein the shaft is a single-filament coil in which one wire is wound in a single filament, or a multi-filament coil in which multiple wires are wound in multiple filaments.

5. 5. The lesion retrieval device of claim 4, A lesion retrieval device, wherein the shaft has a device lumen inside through which a medical device can be inserted.

6. 6. The lesion retrieval device according to any one of claims 1 to 5, further comprising: A lesion retrieval device comprising a rotation transmission mechanism connected to the shaft and transmitting a rotational force to the shaft, thereby rotating the shaft and the spiral convex portion about an axis.

7. 1. An atherectomy device comprising: A lesion retrieval device according to any one of claims 1 to 6; a cutter provided at the distal end of the shaft of the lesion recovery device and capable of cutting biological tissue; An atherectomy device comprising:

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