Suction catheter

Abstract

To provide a suction catheter capable of efficiently sucking an object in a blood vessel.SOLUTION: A suction catheter 10 for sucking and removing an object in a blood vessel includes: an external cylinder 30 as a cylindrical body having a lumen 31, including a tip opening part 32 at the tip; a rotatable drive shaft 20 stored in the lumen 31 movably in the axial direction, and including a projection 27 projecting from the tip opening part 32 to the tip side; and an operation part 40 connected with the base end part of the external cylinder 30, and including an operation part lumen 101 communicated with the lumen 31, and a suction port 91 communicated with the operation part lumen 101 and opened to the outside. The projection 27 can move in the axial direction to the tip opening part 32 while rotating.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to aspiration catheters that are used for insertion into the body to aspirate objects therein. [Background technology]

[0002] Various devices are used to treat stenosed or blocked blood vessels. For example, Patent Document 1 describes a device that cuts and removes plaque in blood vessels using an abrasive segment rotated by a drive shaft.

[0003] In the treatment of acute coronary syndrome (ACS), aspiration catheters are used to aspirate and remove blood clots. Acute coronary syndrome is a condition in which plaque formed on the wall of the coronary artery ruptures, causing rapid narrowing or blockage of the coronary artery lumen. In treatment using aspiration catheters, the surgeon brings the opening at the tip of the aspiration catheter close to the narrowed or blocked part of the coronary artery, and aspirates the blood clots that caused the narrowing or blockage using a suction mechanism such as a syringe or pump. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 5,314,438 Summary of the Invention [Problem to be solved by the invention]

[0005] The hardness and viscosity of thrombi vary depending on the time since onset and the state of the plaque. For this reason, thrombi may become clogged and obstruct the lumen of the aspiration catheter, making it difficult to aspirate thrombi efficiently.

[0006] In addition, a method of aspirating thrombi while dissolving them using a thrombolytic agent is also known for the treatment of acute coronary syndrome. However, this method requires time to reestablish blood flow in patients because it takes time to dissolve the thrombi, which can affect the survival rate, and it is difficult to aspirate thrombi efficiently.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a suction catheter that can efficiently suction objects inside a blood vessel. [Means for solving the problem]

[0008] The above object can be achieved by the invention described in (1) below.

[0009] (1) The suction catheter of the present invention is an suction catheter for removing objects within a blood vessel by suction, comprising: an outer tube which is a cylindrical body having a lumen and a tip opening at its tip; a rotatable drive shaft which is housed in the lumen and is axially movably and has a protrusion which can protrude from the tip opening toward the tip side; and an operating section to which the base end of the outer tube is connected and which has an operating section lumen communicating with the lumen and a suction port which communicates with the operating section lumen and opens to the outside, and the protrusion can move axially relative to the tip opening while rotating. Effect of the Invention

[0010] The suction catheter described in (1) above can efficiently aspirate an object from the tip opening by rotating the protruding portion of the drive shaft and moving it axially relative to the tip opening, thereby pushing the protruding portion into the object in the blood vessel.

[0011] (2) In the suction catheter described in (1) above, the drive shaft may have at least one coil, and the direction in which the coil winds as it moves toward the distal end may coincide with the direction of rotation of the drive shaft, thereby allowing the suction catheter to apply a force toward the proximal end to an object drawn into the lumen by the coil of the rotating drive shaft.

[0012] (3) In the suction catheter according to (1) or (2) above, the outer cylinder may have a convex portion on an inner circumferential surface thereof, whereby the suction catheter can apply a force to an object in the lumen by means of the drive shaft and the convex portion, thereby crushing the object.

[0013] (4) In the suction catheter according to any one of (1) to (3), the protruding portion may have a large diameter portion formed with an outer diameter larger than the outer diameter of the portion of the drive shaft proximal to the protruding portion. This allows the large diameter portion to generate a large resistance when the drive shaft is pushed toward the lesion. Therefore, when the portion of the drive shaft proximal to the large diameter portion is pushed toward the lesion, the resistance is small, making it easier to push the drive shaft into the lesion. Furthermore, when the large diameter portion is disposed within the lesion, the large diameter portion can prevent matter from scattering toward the distal end (peripheral side), thereby preventing peripheral embolism. Furthermore, when the drive shaft moves toward the proximal side while rotating, the large diameter portion can push matter into the lumen of the outer cylinder.

[0014] (5) In the suction catheter described in (4) above, when the drive shaft is positioned at the most proximal end side of its axial movement range, the large diameter portion of the drive shaft may be positioned at a distal end side of the distal end opening, thereby preventing the outer cylinder from being damaged by the rotating large diameter portion.

[0015] (6) In the suction catheter according to any one of (1) to (5) above, the operation section may include an inner tube connected to the drive shaft, movable in the axial direction through the lumen of the outer tube, protruding from the base end of the outer tube toward the base end, a seal section in slidable contact with the outer circumferential surface of the inner tube and sealing the operation section lumen, and a hub connected to the base end of the inner tube to form the suction port and movable in the axial direction together with the drive shaft while rotatably holding the drive shaft, the operation section lumen being formed in communication with the hub and the inner tube. Thus, the suction catheter can change the axial length of the operation section lumen by moving the hub and the inner tube in the axial direction relative to the outer tube, and move the protruding portion of the drive shaft in the axial direction relative to the tip opening of the outer tube. [Brief description of the drawings]

[0016] [Figure 1] 1 is a plan view showing a state in which an inner tube of a suction catheter according to an embodiment of the present invention is pulled out from an outer tube. FIG. [Diagram 2] 2(A) is a cross-sectional view of the tip of a suction catheter, and FIG. 2(B) is a cross-sectional view taken along line AA in FIG. 2(A). [Diagram 3] 1 is a cross-sectional view showing a portion of the suction catheter including a first connector and a second connector. FIG. [Figure 4] FIG. 2 is a cross-sectional view showing the proximal end including the hub of the suction catheter. [Diagram 5] FIG. 2 is a plan view showing an external drive device to which the operating section of the suction catheter is connected. [Figure 6] FIG. 2 is a plan view showing a state in which the inner tube of the suction catheter is pushed into the outer tube. [Figure 7] 1A and 1B are cross-sectional views showing the state of the suction catheter in use, in which (A) the drive shaft has been moved toward the distal end relative to the outer tube and pushed into the lesion, and (B) the drive shaft has been moved toward the proximal end relative to the outer tube. [Figure 8] FIG. 13 is a cross-sectional view showing a state in which the drive shaft is eccentric due to an object contained in the lumen. [Figure 9]1A and 1B are cross-sectional views showing the tip of a suction catheter, in which (A) shows the case where the external cylindrical coil is wound in the same direction as the coil of the drive shaft, and (B) shows the case where the external cylindrical coil is wound in the opposite direction to the coil of the drive shaft. [Figure 10] FIG. 11 is a cross-sectional view showing a tip portion of a suction catheter according to a first modified example. [Figure 11] FIG. 11 is a cross-sectional view showing a tip portion of a suction catheter according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In this specification and the drawings, components having substantially the same functions are given the same reference numerals to avoid duplicated explanation. In this specification, the side of the catheter that is inserted into a blood vessel is referred to as the "tip side" and the side that is operated is referred to as the "base side".

[0018] The suction catheter 10 according to this embodiment is a medical device that is percutaneously inserted into a blood vessel and sucks up and removes objects 201, such as thrombus and plaque, from a stenosed or blocked lesion 200 in a coronary artery to the outside of the body, as shown in Figs. 1 to 4. The suction catheter 10 is suitable for sucking up and removing objects that are basically soft enough to be sucked up, such as a thrombus in a coronary artery, but may contain hard parts. As shown in Fig. 5, the suction catheter 10 is used by being connected to an external drive device 110 that holds the suction catheter 10 and drives a drive shaft 20.

[0019] As shown in FIG. 1, the suction catheter 10 comprises a rotatable drive shaft 20, an outer tube 30 which is a long cylindrical body that is inserted into a blood vessel, and an operating section 40 which holds the base ends of the drive shaft 20 and the outer tube 30.

[0020] As shown in Figures 1 to 4, the outer cylinder 30 has a lumen 31 formed therein for rotatably accommodating the drive shaft 20, and a tip opening 32 where the lumen 31 opens is formed at the tip of the outer cylinder 30. The outer cylinder 30 has an outer cylinder body 33 and an outer cylinder coil 34 partially embedded in the inner circumferential surface of the outer cylinder body 33. The outer cylinder body 33 is a long cylinder that is flexibly deformable. The outer cylinder body 33 has a single-layer structure in Figures 2 to 3, but may have a multi-layer structure.

[0021] The outer tube coil 34 is a single coil formed by winding one wire in a spiral shape, or a multiple-strand coil formed by winding a plurality of wires side by side. The cross-sectional shape of the wire forming the outer tube coil 34 is not particularly limited, but may be, for example, a circle, an ellipse, a rectangle, a square, or the like. The outer tube 30 has a protrusion 35 formed by protruding from the outer tube coil 34 on the inner circumferential surface. The protrusion 35 plays an auxiliary role in crushing a hard thrombus in cooperation with the drive shaft 20. The shape of the protrusion 35 of the outer tube 30 is not particularly limited. Therefore, the protrusion 35 may not be formed by the outer tube coil 34, and may be formed integrally with the outer tube main body 33 by, for example, the same material as the outer tube main body 33. The protrusion 35 may not be formed in a spiral shape. For example, the outer tube 30 may have a plurality of spot-shaped protrusions 35 on the inner circumferential surface. The protrusion 35 may be formed by a braided tube in which a plurality of wires are braided into a cylindrical shape. Moreover, the inner peripheral surface of the outer tube 30 does not need to have the protrusion 35. Therefore, the outer tube 30 does not need to have the outer tube coil 34. Even if the outer tube 30 does not have the protrusion 35, the suction catheter 10 can crush the thrombus by the rotating drive shaft 20.

[0022] The winding direction of the outer cylindrical coil 34 toward the tip may be the same as the rotation direction of the drive shaft 20 (see FIG. 9(A)) or the opposite direction (see FIG. 9(B)).

[0023] 1 to 4, the drive shaft 20 is flexible and has a property of being able to transmit a rotational force received from an external drive device 110 at the operation unit 40 to the tip portion. The drive shaft 20 has a long shaft body 21 and a shaft tip portion 22 fixed to the tip of the shaft body 21.

[0024] The shaft body 21 is formed of a single-layer multi-strand coil in which a plurality of coils 23 are arranged and wound in a spiral shape to form a tube. The shaft body 21 is hollow, but may not be hollow. In the shaft body 21, a plurality of (e.g., five) coils 23 are closely attached to form one coil assembly 25, and the coil assembly 25 is wound in a spiral shape while forming coil gaps 26. The cross-sectional shape of the wire forming the coil 23 is not particularly limited, and may be, for example, a circle, an ellipse, a rectangle, a square, or the like. The recesses 24 between the coils 23 closely attached to the outer circumferential surface of the shaft body 21 and the coil gaps 26 apply a force to an object in the lumen 31 when the drive shaft 20 rotates. It is preferable that the direction in which the coil assembly 25 (or the coils 23) of the shaft body 21 is wound toward the tip coincides with the rotation direction of the drive shaft 20. As a result, an object between the inner peripheral surface of the outer tube 30 and the outer peripheral surface of the shaft body 21 receives a force from the rotating drive shaft 20 toward the base end due to Archimedes' spiral principle (screw pump principle). In this embodiment, the rotation direction of the drive shaft 20 is clockwise when viewed from the base end side, but it may be counterclockwise. The coil assemblies 25 may form a spiral in close contact without forming coil gaps 26. The shaft body 21 may be a multi-layered multi-strand coil in which coil assemblies 25 with alternating winding directions are stacked in the radial direction of the drive shaft 20.

[0025] The drive shaft 20 has a protrusion 27 at its tip that can protrude tipward from a tip opening 32 of the outer cylinder 30. When the drive shaft 20 is positioned at the tip-most side within the movable range relative to the outer cylinder 30, as shown in Fig. 6, the protrusion 27 is located on the tip side of the tip opening 32 of the outer cylinder 30 and is exposed to the outside.

[0026] 1 and 2, the shaft body 21 has, at a part of the protruding portion 27, a large diameter portion 28 having a larger outer diameter than the portion on the base end side. The large diameter portion 28 is a portion where the coil outer diameter of the shaft body 21 is partially increased. It is preferable that the maximum outer diameter of the large diameter portion 28 is equal to or greater than the inner diameter of the tip opening 32 of the outer tube 30. The shaft body 21 has, at the base end side of the large diameter portion 28, a constant outer diameter portion 29 having a constant outer diameter.

[0027] The shaft tip portion 22 has a tip tapered portion 22A that protrudes from the tip of the shaft body 21 while decreasing in diameter toward the tip side, and a most distal portion 22B formed with a smoothly curved surface. The tip tapered portion 22A has a reduced diameter and thus easily penetrates into the thrombus that forms the lesion 200. The most distal portion 22B of the shaft tip portion 22 is formed with a smoothly curved surface, which can suppress damage to the blood vessel wall.

[0028] As shown in FIG. 1, the operating section 40 has a first connector 50 connected to the base end of the outer tube 30, an outer tube 60 connected to the outer tube 30 by the first connector 50 and extending toward the base end, a second connector 70 to which the base end of the outer tube 60 is connected, an inner tube 80 that can move axially inside the outer tube 60, and a hub 90 connected to the base end of the inner tube 80 and in which a suction port 91 is formed.

[0029] As shown in FIGS. 1 and 3, the first connector 50 has a first connector body 51, a first sealing member 52, a first packing 53, and a first anti-kink protector .

[0030] The first connector body 51 is cylindrical, and the base end of the outer tube body 33 is inserted from the tip side and connected. The first sealing member 52 is cylindrical, and is disposed on the base end side of the first connector body 51 and connected to the first connector body 51. The first connector body 51 and the first sealing member 52 are connected by inserting the tip end of the outer tube 60 from the base end side. The first sealing member 52 may be a part of the tip end of the outer tube 60. The first sealing member 52 is combined with the first connector body 51 to hold the first packing 53. The first anti-kink protector 54 is combined with the first connector body 51 to hold the outer tube 30. Since the first packing 53 is sealed between the first connector body 51 and the first sealing member 52, it is possible to suppress leakage of suction force from the first connector 50.

[0031] The outer tube 60 is a tube having a tip end connected to the first connector 50 and a base end connected to the second connector 70 .

[0032] The second connector 70 has a second connector body 71, a second sealing member 72, a second packing 73 (sealing portion), and a cover member 74. The second connector 70 is also a portion to be connected to the external driving device 110.

[0033] The second connector body 71 and the second sealing member 72 are cylindrical, and the base end of the outer tube 60 is inserted and connected. The second sealing member 72 is disposed on the base end side of the second connector body 71 and connected to the second connector body 71. The second sealing member 72 is combined with the second connector body 71 to hold the second packing 73. The cover member 74 is combined with the second connector body 71 to hold the outer tube 60. Since the second packing 73 is sealed between the second connector body 71 and the second sealing member 72, it is possible to suppress leakage of negative pressure from the second connector 70. The second packing 73 is slidable with the outer circumferential surface of the inner tube 80, which is axially movable relative to the second connector 70, while maintaining airtightness.

[0034] As shown in Figs. 1, 3, and 4, the inner tube 80 is a member that can move in the axial direction inside the outer tube 60. The inner tube 80 is arranged in a nested manner so as to be freely inserted and removed from the second connector 70 into the outer tube 60. The outer diameter of the inner tube 80 is smaller than the inner diameter of the outer tube 60. The base end of the inner tube 80 is connected to the hub 90, and the tip end of the inner tube 80 is movable in the axial direction inside the outer tube 60. The inner tube 80 has a stopper 81 at its tip that protrudes radially outward. When the inner tube 80 is pulled out most toward the base end side from the outer tube 60 and the second connector 70, the stopper 81 gets caught on the inner wall of the second connector body 71, preventing the inner tube 80 from coming out of the second connector 70.

[0035] When the inner tube 80 is pulled out to the base end side, as shown in FIG. 1, the stopper 81 formed at the tip of the inner tube 80 is caught on the step 75 of the inner wall of the second connector 70, and the part of the inner tube 80 other than the caught tip is exposed to the outside. In this state, the large diameter part 28 of the drive shaft 20 is located on the tip side of the tip opening 32 of the outer tube 30 and close to the tip opening 32. In this state, the large diameter part 28 of the drive shaft 20 does not contact the tip opening 32 of the outer tube 30. This makes it possible to prevent the outer tube 30 from being damaged by the rotating large diameter part 28. It is preferable that the axial distance between the large diameter part 28 and the tip opening 32 can be changed within a range of, for example, 5 mm to 30 mm.

[0036] 3 and 6, when the inner tube 80 is pushed all the way toward the tip side, the tip of the inner tube 80 reaches near the tip of the outer tube 60, i.e., near the first connector 50. In this state, the large diameter portion 28 of the drive shaft 20 is located further toward the tip side than the tip opening 32 of the outer tube 30.

[0037] 1 and 4, the hub 90 holds the drive shaft 20 and the inner tube 80. When the hub 90 moves toward the distal end together with the inner tube 80 and the drive shaft 20, the inner tube 80 is pushed into the outer tube 60, and the drive shaft 20 moves toward the distal end through the lumen 31 of the outer tube 30. When the hub 90 moves toward the proximal end together with the inner tube 80 and the drive shaft 20, the inner tube 80 is pulled out of the outer tube 60, and the drive shaft 20 moves toward the proximal end through the lumen 31 of the outer tube 30.

[0038] The hub 90 includes a hub body 92 , a joint 93 , a male connector 94 , a rotor 95 , a connecting pipe 96 , a seal member 97 , and a second anti-kink protector 99 .

[0039] Joint 93 has a base end opening 98 on the base end side, and houses male connector 94 and rotor 95 inside. Male connector 94 can be connected to a female connector 117 (see FIG. 5) of external driving device 110 from the base end opening 98 side of joint 93, whereby external driving device 110 and male connector 94 are mechanically connected to each other.

[0040] The rotor 95 is connected to the connecting pipe 96 and the male connector 94, and rotates integrally with the male connector 94 and the connecting pipe 96. The connecting pipe 96 has a base end connected to the rotor 95 and a tip end connected to the base end of the drive shaft 20. Therefore, the connecting pipe 96 transmits the rotation of the rotor 95 to the drive shaft 20.

[0041] The hub body 92 has a suction port 91 and a hub lumen 100 that communicates with the suction port 91 and the lumen of the inner tube 80. The hub lumen 100, the lumen of the inner tube 80, and the lumen of the outer tube 60 communicate with each other to form one operation section lumen 101. The operation section lumen 101 communicates with the suction port 91 and also communicates with the lumen 31 of the outer tube 30. The axial length of the operation section lumen 101 changes when the inner tube 80 moves axially relative to the outer tube 60. The suction port 91 can be connected to a suction mechanism such as a syringe or a pump directly or indirectly via a tube or the like. The suction port 91 is applied with negative pressure as suction force by the suction mechanism connected thereto. Note that a seal member 97 including an O-ring 97A is installed between the hub body 92 and the joint 93, thereby preventing leakage of negative pressure and leakage of liquid in the hub lumen 100 to the base end opening 98 side of the joint 93.

[0042] The base end of the inner tube 80 is inserted into the hub body 92 so that the outer circumferential surface of the inner tube 80 fits into the inner circumferential surface of the hub lumen 100. A second anti-kink protector 99 is disposed around the inner tube 80 and the hub body 92.

[0043] The constituent materials of outer tube body 33, outer tube 60, inner tube 80, hub 90, second connector body 71 and first connector body 51 are not particularly limited, and examples include various resins such as polyvinyl chloride, polyethylene, polypropylene, cyclic polyolefin, polystyrene, poly-(4-methylpentene-1), polycarbonate, acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, polyethylene naphthalate, and other polyesters, butadiene-styrene copolymers, and polyamides (e.g., nylon 6, nylon 6·6, nylon 6·10, nylon 12).

[0044] The materials constituting the coil 23 of the drive shaft 20, the shaft tip portion 22 and the outer cylindrical coil 34 are not particularly limited, and examples thereof include metal materials such as stainless steel and Ni-Ti alloys, and hard resin materials.

[0045] The above-mentioned suction catheter 10 is connected to and driven by an external drive device 110, as shown in Fig. 5. The external drive device 110 is provided with a drive unit 111 that incorporates an external drive source such as a motor and rotates the drive shaft 20 on a base 115, a movement unit 112 that grasps the drive unit 111 and moves it in the axial direction by a motor or the like, and a holding unit 113 that holds a part of the suction catheter 10 in a fixed position. The external drive device 110 is connected to a control unit 119 that controls the drive unit 111 and the movement unit 112.

[0046] The moving unit 112 is capable of gripping and fixing the driving unit 111 , and is a feed mechanism that moves the gripped driving unit 111 back and forth along a groove rail 116 on a base 115 .

[0047] The drive unit 111 has a drive female connector 117 to which the drive male connector 94 of the suction catheter 10 can be connected, and a joint connection portion 118 that can be connected to the joint 93 of the suction catheter 10, and this connection makes it possible to rotate the drive shaft 20.

[0048] Next, a method of using the suction catheter 10 according to this embodiment will be described taking as an example a case in which a lesion 200 formed by the rupture of plaque occurring in a coronary artery is treated.

[0049] First, the surgeon connects the suction catheter 10 to the external driving device 110, as shown in Fig. 5. That is, the joint 93 of the hub 90 of the suction catheter 10 is connected to the joint connection portion 118 of the driving unit 111. Furthermore, the second connector 70 is fitted into the holding portion 113. This completes the connection of the suction catheter 10 to the external driving device 110. Furthermore, the surgeon connects the suction mechanism to the suction port 91.

[0050] Next, by moving the driving part 111 toward the base end side along the groove rail 116 on the base 115, the hub 90 is moved toward the base end side, and the inner tube 80 is pulled out toward the base end side from the outer tube 60, as shown in Fig. 1. At this time, the large diameter part 28 of the drive shaft 20 is disposed closer to the tip opening 32 of the outer tube 30 and closer to the tip opening 32.

[0051] Next, the surgeon inserts the suction catheter 10 into the coronary artery via a guiding catheter or the like that has been percutaneously inserted into a blood vessel and advanced to the vicinity of the coronary artery, and reaches the lesion 200 .

[0052] Next, the surgeon operates the external drive device 110 and the suction mechanism. The external drive device 110 rotates the drive shaft 20 by the drive unit 111, while repeatedly reciprocating the drive shaft 20 in the axial direction by the movement unit 112. Furthermore, the surgeon operates the operation unit 40 and the outer tube 30 to appropriately move the position of the tip opening 32 to a position suitable for suctioning the thrombus that forms the lesion 200. That is, the reciprocating movement of the drive shaft 20 along the axial direction is performed under conditions preset by the external drive device 110, and the movement of the outer tube 30 in the axial direction is performed by the operation of the operation unit 40 and the outer tube 30 by the surgeon's hands. The reciprocating movement of the drive shaft 20 may be performed by the operation of the operation unit 40 and the outer tube 30 by the surgeon. The suction mechanism applies negative pressure from the suction port 91 to the lumen 31, and draws an external object 201 (mainly a thrombus) into the lumen 31 from the tip opening 32.

[0053] When the inner tube 80 is pulled out most toward the base end from the outer tube 60, the large diameter portion 28 of the drive shaft 20 is located on the distal side of the edge of the distal end opening 32 of the outer tube 30 and does not contact the outer tube 30. This makes it possible to prevent the outer tube 30 from being damaged by the rotating large diameter portion 28.

[0054] As shown in FIG. 7A, the drive shaft 20 enters the lesion 200 when moving toward the distal end. The distal end 22 of the drive shaft 20 is provided with a distal tapered portion 22A, so that the drive shaft 20 can efficiently enter the lesion 20. The most distal end 22B of the shaft distal end 22 is formed with a smooth curved surface, so that damage to the blood vessel wall can be suppressed. The large diameter portion 28 is disposed at the distal end of the drive shaft 20, so that the large diameter portion 28 generates a large resistance when the drive shaft 20 is pushed toward the lesion 200. Therefore, when the portion of the drive shaft 20 on the proximal side of the large diameter portion 28 is pushed toward the lesion 200, the resistance is small, and the drive shaft 20 can be easily pushed. Then, when the distal end opening 32 of the outer tube 30 approaches the lesion 200, the negative pressure acting on the distal end opening 32 causes the matter 201 (mainly a thrombus) that forms the lesion 200 to be sucked into the distal end opening 32. A thrombus occurring in a coronary artery is usually soft and does not need to be scraped, and can be drawn into lumen 31 by the suction force generated at distal end opening 32. As shown in FIG. 7(B), when drive shaft 20 moves toward the base end, it draws object 201 forming lesion 200 into distal end opening 32. At this time, drive shaft 20 has large diameter portion 28, so that object 201 forming lesion 200 can be effectively drawn into distal end opening 32.

[0055] When the large diameter portion 28 is disposed in the lesion 200, the large diameter portion 28 can prevent matter 201, such as a thrombus, from scattering toward the tip side (peripheral side), thereby preventing peripheral embolism. When the drive shaft 20 moves toward the base end side while rotating, the large diameter portion 28 can efficiently push matter 201, such as a thrombus, from the tip opening 32 of the outer cylinder 30 into the lumen 31.

[0056] The object 201 such as a thrombus or blood drawn into the lumen 31 moves in the lumen 31 toward the base end side due to the negative pressure applied by the suction mechanism, and is discharged to the outside from the suction port 91 through the operation section inner cavity 101. If the object 201 drawn into the lumen 31 is, for example, a hard thrombus, it may hinder suction. However, since the direction in which the coil 23 of the drive shaft 20 winds toward the tip coincides with the rotation direction of the drive shaft 20, the hard thrombus drawn into the lumen 31 is crushed by the force directed toward the rotation direction and the base end direction from the recess 24 and the coil gap 26 of the rotating drive shaft 20. Therefore, even if the sucked object 201 contains a hard thrombus, it can be efficiently transported toward the base end while being crushed. The thrombus that receives the force from the recess 24 and the coil gap 26 of the rotating drive shaft 20 comes into contact with and is pinched by the protrusion 35 on the inner surface of the outer tube 30, and is more efficiently crushed. Therefore, even if a hard thrombus is aspirated, the suction catheter 10 can efficiently transport the hard thrombus toward the base end while crushing the hard thrombus.

[0057] When a hard object 201 is sucked into the lumen 31, the axis of the drive shaft 20 may be offset from the axis of the outer cylinder 30 as shown in Fig. 8. At this time, a strong force is applied to the object 201 from the drive shaft 20 and the outer cylinder 30, so that the object 201 is efficiently crushed.

[0058] When the external cylinder coil 34 is wound in the same direction as the coil 23 of the drive shaft 20, the coil 23 of the drive shaft 20 and the external cylinder coil 34 are positioned nearly parallel to each other, as shown in Fig. 9(A). Therefore, a clamping force is efficiently applied from the coil 23 of the drive shaft 20 and the external cylinder coil 34 to the object 201 sandwiched between the coil 23 of the drive shaft 20 and the external cylinder coil 34, so that the object 201 can be efficiently crushed.

[0059] When the external cylindrical coil 34 is wound in the opposite direction to the coil 23 of the drive shaft 20, as shown in Fig. 9(B), the object 203, which receives a force from the rotating drive shaft 20 and tries to rotate together with the drive shaft 20, receives a force in the proximal direction from the external cylindrical coil 34. Therefore, the suction catheter 10 can effectively transport the thrombus in the proximal direction.

[0060] The outer cylinder 30 has a structure independent of the drive shaft 20 and does not rotate together with the drive shaft 20. Therefore, the suction catheter 10 uses the outer cylinder 30 to restrict the drive shaft 20 from contacting any part other than the lesion 200, thereby reducing the burden on any part other than the lesion 200. In addition, when the outer cylinder 30 passes through the lesion 200, the outer cylinder 30 does not rotate like the drive shaft 20, and therefore the burden on the lesion 200 can be reduced.

[0061] After the suction of the object 201 forming the lesion 200 is completed, the surgeon stops the suction by the suction mechanism and stops the drive unit 111 and the moving unit 112 of the external drive device 110. Thereafter, the surgeon removes the suction catheter 10 from the blood vessel, completing the operation of the suction catheter 10.

[0062] As described above, the suction catheter 10 according to this embodiment is a suction catheter 10 for removing an object in a blood vessel by suction, and includes an outer tube 30 which is a cylinder having a lumen 31 and a tip opening 32 at its tip, a rotatable drive shaft 20 which is housed in the lumen 31 so as to be movable in the axial direction and has a protrusion 27 which can protrude from the tip opening 32 to the tip side, and an operation section 40 to which the base end of the outer tube 30 is connected and which has an operation section inner cavity 101 which communicates with the lumen 31 and a suction port 91 which communicates with the operation section inner cavity 101 and opens to the outside, and the protrusion 27 is movable in the axial direction relative to the tip opening 32 while rotating. Thus, the suction catheter 10 can efficiently suction an object from the tip opening 32 by rotating the protrusion 27 of the drive shaft 20 and moving it in the axial direction relative to the tip opening 32, while pushing the protrusion 27 into an object in a blood vessel.

[0063] The drive shaft 20 has at least one coil 23, and the direction in which the coil 23 winds as it moves toward the distal end coincides with the direction of rotation of the drive shaft 20. This allows the suction catheter 10 to apply a force toward the proximal end on the object 201 drawn into the lumen 31 by the coil 23 of the rotating drive shaft 20.

[0064] The outer cylinder 30 has a convex portion 35 on its inner circumferential surface. This allows the suction catheter 10 to apply force to an object in the lumen 31 via the drive shaft 20 and the convex portion 35, thereby crushing the object 201.

[0065] The protruding portion 27 has a large diameter portion 28 formed with an outer diameter larger than the outer diameter of the portion of the drive shaft 20 on the proximal side than the protruding portion 27. As a result, when the drive shaft 20 is pushed toward the lesion 200, the large diameter portion 28 generates a large resistance. Therefore, when the portion of the drive shaft 20 on the proximal side than the large diameter portion 28 is pushed toward the lesion 200, the resistance is small, and pushing is easy. In addition, when the large diameter portion 28 is disposed in the lesion 200, the large diameter portion 28 can suppress the scattering of the object 201 of the lesion 200 to the tip side (peripheral side), and peripheral embolism can be suppressed. In addition, when the drive shaft 20 moves toward the proximal side while rotating, the large diameter portion 28 can push the object 201 into the lumen 31 of the outer tube 30.

[0066] When the drive shaft 20 is located at the base end side of its axially movable range, the large diameter portion 28 of the drive shaft 20 is located on the distal side of the distal end opening 32. This makes it possible to prevent the outer tube 30 of the suction catheter 10 from being damaged by the rotating large diameter portion 28.

[0067] The operation section 40 includes an inner tube 80 connected to the drive shaft 20, movable in the axial direction through the lumen 31 of the outer tube 30, and protruding from the base end of the outer tube 30 toward the base end side, a second packing 73 (sealing portion) that slidably contacts the outer circumferential surface of the inner tube 80 and seals the operation section lumen 101, and a hub 90 that is connected to the base end of the inner tube 80 to form a suction port 91 and is movable in the axial direction together with the drive shaft 20 while rotatably holding the drive shaft 20, and the operation section lumen 101 may be formed in communication with the hub 90 and the inner tube 80. In this way, the suction catheter 10 can change the axial length of the operation section lumen 101 by moving the hub 90 and the inner tube 80 in the axial direction relative to the outer tube 30, thereby moving the protruding portion 27 of the drive shaft 20 in the axial direction relative to the tip opening 32 of the outer tube 30.

[0068] The present invention is not limited to the above-described embodiment, and various modifications may be made by those skilled in the art within the technical spirit of the present invention. For example, as in a first modification shown in FIG. 10, the drive shaft 20 does not need to have the large diameter portion 28.

[0069] Also, as in the second modified example shown in FIG. 11, a distal tube 120 having a guidewire lumen 121 penetrating in the axial direction may be connected to the outer peripheral surface of the distal end of the outer tube 30. The distal end of the distal tube 120 is preferably aligned with the distal end of the outer tube 30 in the axial direction or located on the proximal side of the distal end of the outer tube 30. This makes it possible to prevent the distal tube 120 from contacting and being damaged by the drive shaft 20 that protrudes from the outer tube 30 toward the distal side and rotates. The distal end of the distal tube 120 may be located on the distal side of the distal end of the outer tube 30. By using the suction catheter 10 according to the second modified example, the surgeon can move the guidewire ahead of the lesion 200 and make the suction catheter 10 reach the lesion 200 along the guidewire. Also, the surgeon can push not only the suction catheter 10 but also the guidewire into the thrombus to effectively remove the thrombus and effectively eliminate the blockage of the blood vessel. [Explanation of symbols]

[0070] 10 Suction Catheter 20 Drive shaft 23 Coil 27 Protrusion 28 Large diameter section 30 Outer cylinder 31 Lumens 32 Tip opening 34 External coil 35 Convex 40 Control section 60 outer tube 73 Second packing (sealing part) 80 inner tube 90 Hub 91 Suction port 101 Control section lumen 200 Lesions 201 Object (thrombus)

Claims

1. A suction catheter for removing objects from within a blood vessel, comprising: an outer cylinder which is a cylinder having a lumen and has a tip opening at its tip; a rotatable drive shaft that is axially movably housed in the lumen and has a protruding portion that can protrude from the distal end opening toward the distal end; an operation section to which a base end of the sheath is connected and which includes an operation section inner cavity communicating with the lumen and a suction port communicating with the operation section inner cavity and opening to the outside; An aspiration catheter, wherein the protrusion is axially movable relative to the tip opening while rotating.

2. 2. The aspiration catheter of claim 1, wherein the drive shaft includes at least one coil, the direction in which the coil winds as it advances toward the distal end being consistent with the direction of rotation of the drive shaft.

3. The suction catheter according to claim 1 or 2, wherein the outer cylinder has a convex portion on an inner circumferential surface.

4. 3. The suction catheter according to claim 1, wherein the protrusion has a large diameter portion formed with an outer diameter larger than an outer diameter of a portion of the drive shaft that is proximal to the protrusion.

5. The aspiration catheter according to claim 4, wherein when the drive shaft is positioned at the most proximal end side of its axially movable range, the large diameter portion of the drive shaft is positioned on the distal end side of the tip opening.

6. The operation unit includes: an inner tube connected to the drive shaft, movable in the axial direction through the lumen of the outer tube, and protruding from a base end of the outer tube toward a base end side; a seal portion that slidably contacts an outer circumferential surface of the inner tube and seals an inner cavity of the operation portion; a hub connected to a base end of the inner tube to form the suction port, the hub rotatably holding the drive shaft and movable together with the drive shaft in the axial direction, The suction catheter according to claim 1 or 2, wherein the operation portion inner lumen is formed so as to communicate with the hub and the inner tube.

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