Medical device

Abstract

Provided is a medical device (1) provided with a basket (30) having a plurality of wires (20), a connecting member (80) arranged more to the proximal side than the basket (30), and a backet pusher (40) arranged more to the proximal side than the connecting member (80), in which the connecting member (80) can become bent under the weight of the basket (30), and, when the basket (30) and the connecting member (80) are immersed in hot water having a temperature of 37°C for 2 minutes and then a weight of 0.1 g is connected to a position located more to the distal side than a midpoint (P1) of the length between the distal end (30d) of the basket (30) and the proximal end (30p) of the basket (30) in hot water having a temperature of 37°C, the angle (θ1) formed on the proximal side between the extending direction (L1) of the basket pusher (40) when the basket pusher (40) is fixed horizontally and a straight line (L2) that passes the distal end (30d) of the basket (30) and the proximal end (30p) of the basket (30) is 150 degrees or less.

Description

medical devices

[0001] The present invention relates to a medical device for use in a body lumen such as a blood vessel.

[0002] Endovascular treatment is one of the treatments for vascular lesions such as head and neck aneurysms, arteriovenous malformations, arteriovenous fistulas, pulmonary vascular malformations, renal vascular malformations, renal artery aneurysms, abdominal aneurysms, etc. As an endovascular treatment, for example, embolization is used, in which an embolic device having an embolization coil is placed at a target site, such as inside an aneurysm, to promote thrombosis and prevent the aneurysm from rupturing.

[0003] When the opening of an aneurysm or other vessel wall is large, the embolization coil placed inside the aneurysm may escape from the aneurysm. To prevent the coil from escaping, a device may be placed inside the aneurysm or in the blood vessel near the opening of the aneurysm. Another known embolization technique involves placing a basket inside the aneurysm and filling it with coils to retain the coils inside the aneurysm and prevent the aneurysm from rupturing.

[0004] For example, Patent Document 1 describes a device for treating an aneurysm that is located within a parent blood vessel defining a lumen and has a neck and an inner wall that define an inner cavity that communicates with the lumen, the device being configured to be deployed within the lumen and further comprising a foldable member that is adjusted to span the neck of the aneurysm and contact the inner wall when the device is deployed. Patent Document 2 describes a device including a self-expanding elastic permeable shell comprising a plurality of elongated elastic filaments with a woven structure secured to one another at their proximal and distal ends, a radially constrained elongated state configured for delivery within a microcatheter, whereby the thin woven filaments extend longitudinally from the proximal end to the distal end radially adjacent to one another along the length of the filament, and an expanded relaxed state having a spherical longitudinally shortened configuration relative to the radially constrained state, whereby the woven filaments form the self-expanding elastic permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal and distal ends, the shell including a plurality of openings formed between the woven filaments, the largest of which is configured to allow blood flow through the opening at a velocity below the critical thrombosis velocity. Patent Document 3 describes an occlusion device comprising: a substantially tubular structure having a proximal end region and a distal end region, a first expanded state and a second collapsed state, and having dimensions suitable for insertion through the neck of an aneurysm via a patient's vascular system in the second collapsed state, an outer surface capable of contacting the aneurysm in the expanded state, and an inner surface; and a control ring disposed in the proximal end region of the structure, having a substantially annular body at least substantially surrounding the proximal end region to prevent radial expansion of the proximal end region and to provide an engagement feature during operation of the occlusion device.Patent document 4 describes an occlusion device that includes a catheter having a holding portion formed from a plurality of wires braided into a cylindrical shape with a closed proximal end, the closed proximal end having a first opening and a tip that is detachably connected to the holding portion, the catheter having a passage that extends to the distal end of the catheter and is aligned with the first opening of the holding portion, and embolic material in the passage of the catheter can be advanced through the passage, through the first opening, and into the cylindrical shape of the holding portion. Patent document 5 describes a device including a self-expanding permeable shell having a proximal end, a distal end, and a longitudinal axis, the shell including a plurality of elongated elastic filaments having a braided structure, the filaments being fastened at at least one of the proximal end or the distal end of the permeable shell, the permeable shell being configured to be delivered within a microcatheter and being in a radially constrained and extended state, and being in an expanded state having an axially shortened configuration relative to the radially constrained state, the permeable shell having a plurality of openings formed between the braided filaments; and the permeable shell in its expanded state including a plurality of lobes aligned circumferentially. Patent document 6 describes a device comprising an implant that is movable from a folded state to an expanded state, the implant comprising a proximal end, a distal end, and a braided section that forms a substantially continuous braided structure between the proximal end and the distal end, wherein in the expanded state, the implant comprises an outer occlusion bag extending from the proximal end of the implant and capable of occluding the aneurysm neck, an inner occlusion bag extending from the distal end of the implant and forming a groove in the outer occlusion bag, and a folded portion in the braided section positioned between the outer occlusion bag and the inner occlusion bag.

[0005] JP-A-2001-518320 JP-A-2011-519632 JP-A-2015-196092 JP-A-2019-506230 JP-A-2020-509922 JP-A-2020-58808

[0006] In the devices described in Patent Documents 1 to 6, the opening through which a long medical object such as a coil can be inserted is limited. Therefore, depending on the condition of the lesion and the procedure, it can be difficult to insert the long medical object into the device. In order to make it easier to insert the long medical object into the devices described in Patent Documents 1 to 6, the size of the device itself becomes large, which is a problem, and there is room for improvement.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a medical device that allows an elongated medical object to be easily inserted into the basket.

[0008] The medical device that solves the above-mentioned problems is as follows: [1] A medical device comprising: a basket having a plurality of wires; a connecting member disposed proximally of the basket; and a basket pusher disposed proximally of the connecting member, wherein the connecting member can bend due to the weight of the basket, and wherein the angle formed by the direction of extension of the basket pusher and a line passing through the distal end and proximal end of the basket, measured under the following conditions, is 150 degrees or less. [Conditions] After immersing the basket and the connecting member in 37°C warm water for 2 minutes, a 0.1 g weight is attached distally to the midpoint of the length from the distal end to the proximal end of the basket in the 37°C warm water, and the angle formed by the direction of extension of the basket pusher and a line passing through the distal end and proximal end of the basket is measured with the basket pusher fixed horizontally. [2] The medical device according to [1], comprising an outer cylinder having a distal end and a proximal end, wherein the basket is disposed in the lumen of the outer cylinder and is expandable when it is outside the outer cylinder. [3] The medical device according to [1] or [2], wherein the connecting member is separable, thereby allowing the basket to be detached from the basket pusher. [4] The medical device according to any of [1] to [3], wherein the length of the connecting member in the extension direction of the basket pusher is shorter than the length of the basket pusher and the length of the basket, and wherein the three-point bending stress of the material constituting the connecting member is lower than the three-point bending stress of the material constituting the basket pusher and the three-point bending stress of the material constituting the basket. [5] The medical device according to any of [1] to [4], wherein the connecting member is located inside the basket pusher at the distal end of the basket pusher, and wherein the outer diameter of the connecting member in a dry state is smaller than the outer diameter of the distal end of the basket pusher and the outer diameter of the proximal end of the basket.[6] The medical device according to any one of [1] to [4], wherein the connecting member is located outside the basket pusher at the distal end of the basket pusher, and wherein, in a dry state, the outer diameter of the connecting member is larger than the outer diameter of the distal end of the basket pusher and smaller than the outer diameter of the proximal end of the basket. [7] The medical device according to any one of [1] to [6], wherein the connecting member is made of a synthetic resin, and wherein the basket pusher and the basket are made of a metal. [8] The medical device according to any one of [1] to [7], wherein the connecting member is made of a material that melts when heated, and further comprises a heating mechanism that heats the connecting member. [9] The medical device according to any one of [1] to [8], wherein the basket comprises a first bundling portion at a distal portion thereof that bundles and secures the plurality of wires, and a second bundling portion at a proximal portion thereof that bundles and secures the plurality of wires, and in a cross section perpendicular to the extension direction of the basket pusher, the connecting member is disposed inside the second bundling portion, and the wires are disposed outside the connecting member.

[10] The medical device according to [9], wherein the first bundling portion and the second bundling portion contain a radiopaque material.

[0009] The aneurysm treatment method of the present invention that solves the above-mentioned problems is as follows:

[11] A method for treating an aneurysm using a medical device comprising: a basket having a plurality of wires; a connecting member arranged proximally of the basket; and a basket pusher arranged proximally of the connecting member, wherein the connecting member can bend due to the weight of the basket, and wherein the angle formed proximally between the extension direction of the basket pusher and a line passing through the distal end and proximal end of the basket, as measured under the following conditions, is 150 degrees or less, the method comprising: inserting the basket into an artery and expanding the basket within an aneurysm in the artery; and pushing the basket pusher in the extension direction to set the angle formed proximally between the extension direction of the basket pusher and a line passing through the distal end and proximal end of the basket to 150 degrees or less. [Conditions] After immersing the basket and the connecting member in 37°C warm water for 2 minutes, a 0.1 g weight is attached to the basket in 37°C warm water distal to the midpoint of the length from the distal end to the proximal end of the basket, and the angle formed by the direction of extension of the basket pusher with the basket pusher fixed horizontally and the straight line passing through the distal end and proximal end of the basket is measured on the proximal side.

[12] The method for treating an aneurysm described in

[11] , which includes a step of placing an elongated medical object in the basket.

[0010] According to the medical device of the present invention, the connecting member can bend under the weight of the basket. After immersing the basket and connecting member in 37°C warm water for two minutes, and then attaching a 0.1 g weight distal to the midpoint of the length from the distal end to the proximal end of the basket in the 37°C warm water, the angle formed by the direction of extension of the basket pusher with the basket pusher fixed horizontally and a line passing through the distal end and proximal end of the basket is 150 degrees or less, allowing the basket to be tilted relative to the basket pusher. Therefore, for example, when the basket is placed inside the aneurysm after passing through the opening of the aneurysm, the side surface of the basket can be oriented toward the opening of the aneurysm. Because the gaps between the multiple wires of the basket tend to be larger at the side surface of the basket than at the proximal and distal ends, this facilitates the insertion of a long medical object, such as a coil, into the basket through the gaps between the multiple wires.

[0011]

[0023] Figure 1 shows a cross-sectional view parallel to the extension direction of a basket pusher at the distal end of a medical device in one embodiment of the present invention. Figure 2 shows a cross-sectional view parallel to the extension direction of a basket pusher in the medical device shown in Figure 1 when the basket is housed in the outer tube. Figure 3 shows an enlarged cross-sectional view parallel to the extension direction of a basket pusher at a portion where a connecting member of the medical device shown in Figure 1 is located. Figure 4 shows an enlarged cross-sectional view parallel to the extension direction of a basket pusher at a portion where a connecting member of a medical device in another embodiment of the present invention is located. Figure 5 shows a V-V cross-sectional view of the medical device shown in Figure 3. Figure 6 shows a VI-VI cross-sectional view of the medical device shown in Figure 3. Figure 7 shows a VII-VII cross-sectional view of the medical device shown in Figure 4.

[0012] The present invention will be described in more detail below based on the following embodiments. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, reference should be made to the specification and other drawings. The dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to helping understand the features of the present invention.

[0013] FIG. 1 is a cross-sectional view parallel to the extension direction of a basket pusher 40 at the distal end of a medical device 1 according to an embodiment of the present invention. In the present invention, the proximal side refers to the side closer to the user in the extension direction of the basket pusher 40, and the distal side refers to the side opposite the proximal side, i.e., the side where treatment is performed by the medical device 1 (the side of the lesion). The extension direction of the basket pusher 40 may also be referred to as the longitudinal axis direction. The longitudinal axis direction of the basket pusher 40 can also be referred to as the direction of approach to the basket pusher 40. In FIG. 1, the right side of the drawing is the proximal side, and the left side of the drawing is the distal side. In FIG. 1, only some of the multiple wires 20 of the basket 30 are illustrated, and the other wires are omitted, to make it easier to understand the relative positions of the various components and parts.

[0014] As shown in FIG. 1 , the medical device 1 of the present invention comprises a basket 30 having a plurality of wires 20, a connecting member 80 arranged proximally of the basket 30, and a basket pusher 40 arranged proximally of the connecting member 80, wherein the connecting member 80 can bend due to the weight of the basket 30, and the angle θ1 formed proximally between the extension direction L1 of the basket pusher 40 and a straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30, as measured under the following conditions, is 150 degrees or less. [Conditions] After immersing the basket 30 and connecting member 80 in 37°C warm water for 2 minutes, a 0.1 g weight is connected distal to the midpoint P1 of the length from the distal end 30d of the basket 30 to the proximal end 30p of the basket 30 in the 37°C warm water, and the angle θ1 formed proximally between the extension direction L1 of the basket pusher 40 with the basket pusher 40 fixed horizontally and a straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is measured.

[0015] The medical device 1 can be used in embolization, which involves placing a basket 30 in a vascular lesion such as an aneurysm to promote thrombosis and prevent the aneurysm from rupturing. In embolization, the basket 30 is placed, for example, within an aneurysm at the terminal end of a biological lumen, within an aneurysm in the side wall of a biological lumen, or within the peripheral portion of a main duct of a biological lumen, and an elongated medical object is placed inside the basket 30 placed within the aneurysm or the peripheral portion of the main duct to promote thrombosis of the aneurysm. Examples of the elongated medical object include coils, wires, and string-like objects. Furthermore, the elongated medical object may be a tube for transporting elongated objects such as coils. Additionally, the tubular elongated medical object may be used to transport semi-solid fluids, gels, semi-solids, liquids, or even bag-like objects into the aneurysm. The liquid in the tubular elongated medical object may be, for example, a hardening liquid or a precipitating liquid.

[0016] As shown in Figure 1, the basket 30 has a plurality of wires 20. The basket 30 is expandable and contractible. Specifically, the basket 30 contracts to a reduced diameter when subjected to an external force, and expands to an increased diameter when not subjected to an external force. When the basket 30 is placed inside the aneurysm, the basket 30 comes into contact with the aneurysm wall and is subjected to external force from the aneurysm, causing it to deform.

[0017] The material constituting the wire 20 is preferably elastic, and examples thereof include metal wires such as single wires, flat wires, double wires, composite material wires, or stranded wires made of stainless steel such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloys, Co-Cr alloys, etc. Among these, the material constituting the wire 20 is preferably a superelastic material, and more preferably a Ni-Ti alloy metal wire. Using a Ni-Ti alloy metal wire as the material constituting the wire 20 increases the elasticity of the wire 20, which allows the basket 30 to return to its original shape even if the basket 30 is significantly deformed after being released from the outer tube 10, making it less likely to lose its shape.

[0018] The basket 30 may have a plurality of wires 20, and the number of wires 20 can be selected depending on the inner diameter of the lumen in the body, etc. In the drawings, the number of wires 20 in the basket 30 is limited. However, in an embodiment of the present invention, the basket 30 may be configured, for example, from 8 to 64 wires 20. The wire diameter of the wires 20 can be set depending on the size of the basket 30, the number of wires 20, the material, etc. The number of wires 20 in the basket 30 is preferably 16 to 32.

[0019] As shown in Fig. 1 , the connecting member 80 is disposed proximal to the basket 30. The connecting member 80 is a member that connects the basket 30 and the basket pusher 40. In other words, the basket 30 and the basket pusher 40 are directly or indirectly connected via the connecting member 80. Because the medical device 1 has the connecting member 80 proximal to the basket 30 and distal to the basket pusher 40, the basket 30 and the basket pusher 40 can be easily connected to each other.

[0020] The connecting member 80 is preferably detachable. In other words, it is preferable that the basket 30 can be detached from the basket pusher 40 by detaching the connecting member 80. Since the connecting member 80 is detachable, the basket 30 can be detached from the basket pusher 40 by detaching the connecting member 80 after transporting the basket 30 to the target site, making it easier to place the basket 30 at the target site.

[0021] The connecting member 80 can be separated by various methods, such as a mechanical separation mechanism, fusing, thermal, electrical, or chemical separation. Examples of the connecting member 80 include a rod-shaped object, a string-shaped object, a clip, or a member that fits together with irregularities. The connecting member 80 can be made of a material such as a synthetic resin or metal. The connecting member 80 may be a separate member from the basket 30 or the basket pusher 40, or may be a part of the basket 30 or the basket pusher 40.

[0022] As shown in FIG. 1 , the basket pusher 40 is disposed proximal to the connecting member 80. The basket pusher 40 is connected to the basket 30 via the connecting member 80, and can move the basket 30 in the longitudinal direction of the outer cylinder 10 to release the basket 30 from the outer cylinder 10 or store the basket 30 within the outer cylinder 10. Although not shown, the basket pusher 40 may be provided with a handle at the proximal end of the outer cylinder 10 for controlling its position in the longitudinal direction and rotation.

[0023] The material constituting the basket pusher 40 is preferably a metal, such as stainless steel, carbon steel, or a nickel-titanium alloy. Among these, the material constituting the basket pusher 40 is preferably stainless steel. Using stainless steel as the material constituting the basket pusher 40 can increase the rigidity of the basket pusher 40. As a result, the force applied to the basket pusher 40 can be efficiently transmitted to the basket 30, making it easier to move the basket 30 in the longitudinal direction.

[0024] 1 , connecting member 80 can bend due to the weight of basket 30, and the angle θ1 formed proximally between the extension direction L1 of basket pusher 40 and a line L2 passing through distal end 30d of basket 30 and proximal end 30p of basket 30, as measured under the following conditions, is 150 degrees or less. [Conditions] After immersing basket 30 and connecting member 80 in 37°C warm water for two minutes, a 0.1 g weight is connected distally to midpoint P1 of the length from distal end 30d of basket 30 to proximal end 30p of basket 30 in the 37°C warm water, and then the angle θ1 formed proximally between the extension direction L1 of basket pusher 40 and a line L2 passing through distal end 30d of basket 30 and proximal end 30p of basket 30 is measured with basket pusher 40 fixed horizontally.

[0025] As shown in Figure 1, when the distal end of the basket 30 is concave, the midpoint of an imaginary line (shown by a dashed line in Figure 1) connecting the most distal portions of at least two wires 20 that the basket 30 has is defined as the distal end 30d of the basket 30.

[0026] The angle θ1 formed by the extension direction L1 of the basket pusher 40 and the straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 toward the proximal side is 150 degrees or less, making the connecting member 80 flexible and capable of bending, allowing the basket 30 to be tilted relative to the basket pusher 40. Therefore, for example, when the basket 30 is placed inside the aneurysm after passing through the opening of the aneurysm, pushing the basket pusher 40 bends the connecting member 80, causing the distal end of the basket 30 to rotate toward the proximal side. As a result, the side surface of the basket 30 can be oriented toward the opening of the aneurysm. Because the gaps between the multiple wires 20 in the side surface of the basket 30 tend to be larger than those at the proximal and distal ends of the basket 30, it is easier to insert a long medical object, such as a coil, into the basket 30 through the gaps between the multiple wires 20.

[0027] The angle θ1 formed on the proximal side between the extension direction L1 of the basket pusher 40 and a straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is 150 degrees or less. In particular, the angle θ1 formed on the proximal side between the extension direction L1 of the basket pusher 40 and the straight line L2 is preferably 145 degrees or less, more preferably 140 degrees or less, even more preferably 135 degrees or less, still more preferably 130 degrees or less, particularly preferably 125 degrees or less, and most preferably 120 degrees or less. By setting the upper limit of the angle θ1 within the above range, the basket 30 can be more easily rotated toward the lateral side of the proximal end 30p of the basket 30, making it easier to insert an elongated medical object between the multiple wires 20 carried by the basket 30.

[0028] Furthermore, the angle θ1 formed on the proximal side between the extension direction L1 of the basket pusher 40 and a straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is preferably equal to or greater than 70 degrees, more preferably equal to or greater than 75 degrees, even more preferably equal to or greater than 80 degrees, even more preferably equal to or greater than 85 degrees, and particularly preferably equal to or greater than 90 degrees. By setting the lower limit of the angle θ1 within the above range, the basket 30 can be more easily rotated toward the lateral side than the distal end 30d of the basket 30, making it easier to insert a long medical object such as a coil through gaps between the multiple wires 20 of the basket 30.

[0029] After immersing the basket 30 and connecting member 80 in 37°C warm water for two minutes, a weight is attached to the distal side of the midpoint P1 of the length from the distal end 30d of the basket 30 to the proximal end 30p of the basket 30 in the 37°C warm water, and the mass of the weight such that the angle θ1 formed by the direction of extension L1 of the basket pusher 40 when the basket pusher 40 is fixed horizontally and a line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is 150 degrees or less is preferably 0.1 g or less, more preferably 0.05 g or less, and even more preferably 0.01 g or less. Setting the upper limit of the mass of the weight such that the angle θ1 is 150 degrees or less within the above range increases the flexibility of the connecting member 80, making it easier for the distal end of the basket 30 to rotate toward the proximal side. The lower limit of the mass of the weight for which the angle θ1 is 150 degrees or less is not particularly limited, but can be, for example, 0.001 g or more.

[0030] When basket pusher 40 is fixed horizontally, the angle θ1 formed by the extension direction L1 of basket pusher 40 and the straight line L2 passing through distal end 30d of basket 30 and proximal end 30p of basket 30 on the proximal side is 180 degrees. This angle is expressed as 12 o'clock relative to basket pusher 40 using an analog clock to indicate direction. If the basket 30 and connecting member 80 are immersed in 37°C warm water for two minutes, and then a 0.1 g weight is connected distal to midpoint P1 of the length from distal end 30d of basket 30 to proximal end 30p of basket 30 in the 37°C warm water, then basket 30 is preferably oriented between 8 and 10 o'clock relative to basket pusher 40. By oriented between 8 and 10 o'clock relative to basket pusher 40, connecting member 80 can bend sufficiently easily, making it easier for basket 30 to rotate closer to the side portion than distal end 30d of basket 30.

[0031] Fig. 2 is a cross-sectional view parallel to the extension direction of the basket pusher 40 in a state in which the basket 30 is housed in the outer cylinder 10. In Fig. 2, the right side of the drawing is the proximal side, and the left side of the drawing is the distal side.

[0032] As shown in FIG. 2 , the medical device 1 includes an outer tube 10 having a distal end 10d and a proximal end 10p. The basket 30 is disposed within the inner cavity of the outer tube 10 and is preferably expandable upon exiting the outer tube 10. That is, the basket 30 is disposed within a lumen of the outer tube 10 and is preferably expandable upon release from the outer tube 10. When disposed within the inner cavity of the outer tube 10, the basket 30 contacts the inner wall of the outer tube 10 and is contracted and reduced in diameter upon receiving an external force from the outer tube 10. When released from the outer tube 10, the basket 30 is no longer subjected to that external force and, in the absence of any other external force, expands and is in an expanded state. Disposing the basket 30 within the inner cavity of the outer tube 10 facilitates transport of the basket 30 to a target site, facilitating procedures such as embolization using the medical device 1.

[0033] The outer cylinder 10 is a tubular member extending in the longitudinal direction and has at least one lumen extending in the longitudinal direction. The outer cylinder 10 may have multiple lumens, but preferably has one. By having only one lumen, the outer diameter of the outer cylinder 10 can be reduced. As a result, the minimal invasiveness of the medical device 1 can be improved.

[0034] The material constituting the outer tube 10 is preferably a resin or metal. Examples of resins constituting the outer tube 10 include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, and natural rubber. These may be used alone or in combination. Among these, the resin constituting the outer tube 10 is preferably at least one of polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins. By using at least one of polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins as the material constituting the outer tube 10, the surface slipperiness of the outer tube 10 can be improved, thereby improving insertion into a lumen such as a blood vessel. The resin tube that forms the outer tube 10 can be manufactured using conventional methods such as extrusion molding and injection molding.

[0035] Examples of metals that can be used to form the outer tube 10 include stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, and combinations thereof. The metal tube that forms the outer tube 10 may be a tube made by spirally winding metal wire or a tube made by braiding metal wire. The outer tube 10 may also be a tube made by combining metal and resin. The outer tube 10 may be a resin tubular body with a reinforcing material such as a metal wire. When the outer tube 10 is a resin tubular member with a wire disposed therein, a Ni-Ti alloy wire is preferred due to its excellent shape memory and high elasticity. The wire may also be the above-mentioned metal or a fiber material such as polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, or carbon fiber. The fiber material may be monofilament or multifilament.

[0036] The outer cylinder 10 may be made of a single layer or multiple layers. Also, in the longitudinal direction, a portion of the outer cylinder 10 may be made of a single layer, and another portion may be made of multiple layers.

[0037] The outer surface of the sheath 10 is preferably coated with a hydrophilic resin. That is, the sheath 10 preferably has a hydrophilic resin layer on the outside of the sheath 10. Coating the outer surface of the sheath 10 with a hydrophilic resin increases the slipperiness of the sheath 10, thereby improving the insertability within a lumen in a living body.

[0038] Furthermore, the outer cylinder 10 preferably has an inner surface coated with a fluororesin. In other words, the outer cylinder 10 preferably has a fluororesin layer on the inside of the outer cylinder 10. By having a fluororesin layer on the inside of the outer cylinder 10, the slipperiness of the inner surface of the outer cylinder 10 is improved. Therefore, it becomes easier to move the basket 30 in the longitudinal direction within the inner cavity of the outer cylinder 10.

[0039] The cross-sectional shape of the outer shape of the outer cylinder 10 in a cross section perpendicular to the longitudinal axis direction may be circular, elliptical, polygonal, or a combination thereof. The cross-sectional shape of the inner cavity of the outer cylinder 10 in a cross section perpendicular to the longitudinal axis direction may also be circular, elliptical, polygonal, or a combination thereof.

[0040] The basket 30 is preferably slidable within a cylinder having an inner diameter of 0.021 inches (0.5334 mm) or less. When the outer cylinder 10 has one lumen, the inner diameter of the outer cylinder 10 is preferably 0.021 inches or less, and the basket 30 is disposed within the lumen of this outer cylinder 10. Furthermore, when the outer cylinder 10 has multiple lumens, the inner diameter of the lumen in which the basket 30 is disposed is preferably 0.021 inches or less. By allowing the basket 30 to slide within a cylinder having an inner diameter of 0.021 inches or less, the outer diameter of the outer cylinder 10 can be reduced, resulting in a medical device 1 that is easy to insert and minimally invasive.

[0041] It is preferable that the connecting member 80 is separable, allowing the basket 30 to be detached from the basket pusher 40. In other words, it is preferable that the basket 30 can be detached from the basket pusher 40 by separating the connecting member 80. Because the connecting member 80 is separable, the basket 30 can be detached from the basket pusher 40 by separating the connecting member 80 after transporting the basket 30 to the target site, making it easier to place the basket 30 at the target site.

[0042] The connection member 80 can be separated by various methods such as a mechanical separation mechanism, fusing, thermal, electrical, or chemical separation.

[0043] As shown in FIG. 2 , the length of the connecting member 80 in the extension direction of the basket pusher 40 is preferably shorter than the lengths of the basket pusher 40 and the basket 30. Furthermore, the three-point bending stress of the material constituting the connecting member 80 is preferably lower than the three-point bending stress of the material constituting the basket pusher 40 and the three-point bending stress of the material constituting the basket 30. In other words, the material constituting the connecting member 80 preferably has a lower three-point bending stress than both the material constituting the basket pusher 40 and the material constituting the basket 30. Because the length of the connecting member 80 in the extension direction of the basket pusher 40 is shorter than the lengths of the basket pusher 40 and the basket 30, and the three-point bending stress of the material constituting the connecting member 80 is lower than the three-point bending stress of the material constituting the basket pusher 40 and the three-point bending stress of the material constituting the basket 30, the connecting member 80 is more flexible than the basket pusher 40 and the basket 30. Therefore, the connecting member 80 is more likely to bend due to the weight of the basket 30.

[0044] The three-point bending stress is the bending stress determined by a three-point bending test of a test piece. The bending stress can be determined by the following formula: σ = M / Z = (8PL) / (πd3) σ: bending stress M: (PL) / 4: moment Z: (2I) / D: section modulus I: second moment of area If the test piece is a round bar, I: (πD4) / 64 If the test piece is a cylindrical bar, I: (π / 64) x (D4 / d4) D: outer diameter of the test piece d: diameter of the inner cavity of the test piece P: bending load L: distance between supports

[0045] The length of the connecting member 80 in the extension direction of the basket pusher 40 is preferably 50% or less of the length of the basket 30, more preferably 40% or less, and even more preferably 30% or less. By setting the upper limit of the ratio of the length of the connecting member 80 to the length of the basket 30 within the above range, the strength of the connecting member 80 is sufficient, and the force that pushes the basket pusher 40 and moves it distally is easily transmitted to the basket 30. Furthermore, the length of the connecting member 80 in the extension direction of the basket pusher 40 is preferably 5% or more of the length of the basket 30, more preferably 7% or more, and even more preferably 10% or more. By setting the lower limit of the ratio of the length of the connecting member 80 to the length of the basket 30 within the above range, the flexibility of the connecting member 80 is increased, making the connecting member 80 more easily bendable.

[0046] Fig. 3 is an enlarged cross-sectional view parallel to the extension direction of the basket pusher 40 at a portion where the connecting member 80 is located in the medical device 1 according to an embodiment of the present invention, Fig. 5 is a cross-sectional view perpendicular to the extension direction of the basket pusher 40 at the second binding portion 52 of the medical device 1, and Fig. 6 is a cross-sectional view perpendicular to the extension direction of the basket pusher 40 at a portion where the connecting member 80 is located inside the basket pusher 40 of the medical device 1. Note that in Fig. 3, the right side of the figure is the proximal side, and the left side of the figure is the distal side. Also, in Fig. 3, only some of the multiple wires 20 of the basket 30 are shown, and the other wires are not shown, so that the positional relationships between the various components and parts can be easily understood.

[0047] 3 , 5 , and 6 , at the distal end 40d of the basket pusher 40, the connecting member 80 is located inside the basket pusher 40, and in a dry state, the outer diameter of the connecting member 80 is preferably smaller than the outer diameter of the distal end 40d of the basket pusher 40 and the outer diameter of the proximal end 30p of the basket 30. In other words, the proximal end 80p of the connecting member 80 is preferably located inside the basket pusher 40, and the distal end 80d of the connecting member 80 is preferably located inside the basket 30. Since the proximal end 80p of the connecting member 80 is located inside the basket pusher 40 and the distal end 80d of the connecting member 80 is located inside the basket 30, the proximal end portion including the proximal end 80p of the connecting member 80 is protected by the basket pusher 40, and the distal end portion including the distal end 80d of the connecting member 80 is protected by the basket 30, making it less likely that the connecting member 80 will unintentionally detach from the basket pusher 40 or the basket 30.

[0048] Fig. 4 is an enlarged cross-sectional view parallel to the extension direction of the basket pusher 40 at a portion where a connecting member 80 is located in a medical device 1 according to another embodiment of the present invention, and Fig. 7 is a cross-sectional view perpendicular to the extension direction of the basket pusher 40 at a portion where the basket pusher 40 is located inside the connecting member 80 of the medical device 1. Note that in Fig. 4, the right side of the figure is the proximal side, and the left side of the figure is the distal side. Also, in Fig. 4, to make it easier to understand the positional relationships between the various components and parts, only some of the multiple wires 20 of the basket 30 are shown, and the other wires are not shown.

[0049] 4 and 7 , at the distal end 40d of the basket pusher 40, the connecting member 80 is located outside the basket pusher 40, and in a dry state, the outer diameter of the connecting member 80 is preferably larger than the outer diameter of the distal end 40d of the basket pusher 40 and smaller than the proximal end 30p of the basket 30. In other words, the distal end 40d of the basket pusher 40 is preferably located inside the connecting member 80, and the distal end 80d of the connecting member 80 is preferably located inside the basket 30. By having the distal end 40d of the basket pusher 40 located inside the connecting member 80, the distal end portion of the basket pusher 40, including the distal end 40d, is located inside the connecting member 80, which increases the rigidity of the connecting member 80 near the proximal end 80p in a dry state. Therefore, the force that pushes the basket pusher 40 from the proximal side toward the distal side in order to transport the basket 30 is easily transmitted to the basket 30 via the connecting member 80, thereby improving the pushability of the medical device 1. Furthermore, because the distal end 80d of the connecting member 80 is located inside the basket 30, the distal end portion, including the distal end 80d of the connecting member 80, is protected by the basket 30, making it difficult for the connecting member 80 to detach from the basket 30.

[0050] It is preferable that connecting member 80 is made of a synthetic resin, and that basket pusher 40 and basket 30 are made of a metal. By making connecting member 80 out of a synthetic resin and making basket pusher 40 and basket 30 out of metal, connecting member 80 can be made more flexible than basket pusher 40 and basket 30, and connecting member 80 is more likely to bend due to the weight of basket 30.

[0051] The material constituting the connecting member 80 preferably has the property of melting when heated, and the medical device 1 preferably has a heating mechanism 90 that heats the connecting member 80. Because the material constituting the connecting member 80 has the property of melting when heated and the medical device 1 has the heating mechanism 90, the connecting member 80 can be heated by the heating mechanism 90 to melt and break, allowing the basket 30 to be separated from the basket pusher 40. Therefore, the basket 30 and the basket pusher 40 can be firmly connected by the connecting member 80 until the heating mechanism 90 is activated, and the connecting member 80 can be easily separated when the heating mechanism 90 is activated, allowing the basket 30 to be placed reliably and easily.

[0052] The material that melts when heated and that constitutes the connecting member 80 is preferably a thermoplastic resin, and more preferably PVA (polyvinyl alcohol). Using PVA as the material that constitutes the connecting member 80 makes it easier to detach the connecting member 80, making it possible to provide a medical device 1 that is easy to handle.

[0053] The heating mechanism 90 is preferably connected to the basket pusher 40. By connecting the heating mechanism 90 to the basket pusher 40, the connecting member 80 can be heated via the basket pusher 40, eliminating the need to provide a separate member for transferring heat from the heating mechanism 90 to the connecting member 80, and allowing the medical device 1 to be made smaller.

[0054] 1 and 2, the basket 30 includes a first bundling portion 51 that bundles and secures the plurality of wires 20 at its distal portion, and a second bundling portion 52 that bundles and secures the plurality of wires 20 at its proximal portion, and as shown in Fig. 5, in a cross section perpendicular to the extension direction of the basket pusher 40, the connecting member 80 is preferably disposed inside the second bundling portion 52 and the wires 20 are preferably disposed outside the connecting member 80. By disposing the connecting member 80 inside the second bundling portion 52 and the wires 20 outside the connecting member 80, the connection strength between the connecting member 80 and the basket 30 can be increased, making it possible to prevent the basket 30 from unintentionally detaching.

[0055] The basket 30 is preferably configured in a cage shape by braiding a plurality of bent wires 20 or right-handed and left-handed spiral wires 20 between the first bundling part 51 and the second bundling part 52. In particular, the basket 30 is preferably configured by braiding right-handed spiral wires 20 and left-handed spiral wires 20. By configuring the basket 30 by braiding right-handed spiral wires 20 and left-handed spiral wires 20, the basket 30 has a cage-like shape with mesh-like walls. As a result, objects contained inside the basket 30 are less likely to escape to the outside of the basket 30, making it easier to efficiently promote thrombosis.

[0056] Methods for bundling and securing the plurality of wires 20 in the first bundling section 51 and the second bundling section 52 include, for example, welding the plurality of wires 20, crimping the plurality of wires 20 together with a separate member, bonding with an adhesive, securing with a brazing material, and combinations thereof. Among these, it is preferable to secure the plurality of wires 20 by crimping them with a separate member in the first bundling section 51 and the second bundling section 52. By crimping and securing the plurality of wires 20 with a separate member in the first bundling section 51 and the second bundling section 52, the plurality of wires 20 can be more firmly secured in the first bundling section 51 and the second bundling section 52, making the basket 30 less susceptible to damage.

[0057] In the first bundling section 51 and the second bundling section 52, examples of the separate member that bundles and secures the multiple wires 20 include a ring-shaped member, a member with a C-shaped cross section with a notch in the ring, a coil-shaped member with a wound wire, and a member that ties and secures the multiple wires 20 with a string-like material. Among these, the separate member that bundles and secures the multiple wires 20 is preferably a ring-shaped member, and more preferably, the ring-shaped member is held or secured by swaging. By using a ring-shaped member that bundles and secures the multiple wires 20 and is held or secured by swaging, the multiple wires 20 can be firmly secured and the multiple wires 20 can be made difficult to unbind.

[0058] The separate member that ties together and secures the wires 20 can be made of a material similar to that of the wires 20 of the basket 30 or the basket pusher 40. Among these, the separate member that ties together and secures the wires 20 is preferably made of stainless steel. Using stainless steel as the material for the separate member that ties together and secures the wires 20 can increase the strength of the wires 20 and improve the durability of the separate member that ties together and secures the wires 20. Furthermore, the separate member that ties together and secures the wires 20 is preferably made of a radiopaque material. Examples of radiopaque materials include platinum, gold, tungsten, iridium, tantalum, and alloys of at least one of these metals. By using a radiopaque material for the separate member that ties together and secures the wires 20, the positions of the first bundling portion 51 and the second bundling portion 52 can be confirmed under X-ray fluoroscopy, making it possible to determine the position of the basket 30 within the body.

[0059] As shown in Fig. 2, when the basket 30 is housed in the outer tube 10, the first bundling portion 51 is preferably located distal to the distal ends 20d of the wires 20. The first bundling portion 51 is a portion that bundles and secures the plurality of wires 20 of the basket 30. When the basket 30 is housed in the outer tube 10, the first bundling portion 51 is located distal to the distal ends 20d of the wires 20, which makes it difficult for the plurality of wires 20 bundled by the first bundling portion 51 to come apart. This makes it easier to release the basket 30 from the outer tube 10 while the plurality of wires 20 maintain their respective phases.

[0060] As shown in Figure 2, the second bundling part 52 is preferably located more proximal than the proximal end 20p of the wire 20. Like the first bundling part 51, the second bundling part 52 is a part that bundles and secures the multiple wires 20 of the basket 30, and therefore tends to be more rigid than other parts of the basket 30. By locating the second bundling part 52 more proximal than the proximal end 20p of the wire 20, the rigidity of the proximal end of the basket 30 can be increased, and a force applied from the proximal side to push the basket 30 distally can be efficiently transmitted to the basket 30. As a result, the medical device 1 can be configured to easily release the basket 30 from the outer tube 10.

[0061] The first binding part 51 and the second binding part 52 preferably contain an X-ray opaque material. By including the X-ray opaque material in the first binding part 51 and the second binding part 52, the positions of the first binding part 51 and the second binding part 52 can be confirmed under X-ray fluoroscopy. As a result, it becomes possible to grasp the position of the basket 30 within the body.

[0062] Examples of radiopaque materials include platinum, gold, tungsten, iridium, tantalum, and alloys of at least one of these.

[0063] The wire 20 of the basket 30 preferably contains a superelastic alloy. When the wire 20 contains a superelastic alloy, the basket 30 has excellent elasticity. The excellent elasticity of the basket 30 allows the basket 30 to have a large deformation amount. Therefore, the basket 30 can be housed in an outer tube 10 with a small outer diameter, and when the basket 30 is outside the outer tube 10, the basket 30 can be greatly expanded.

[0064] The wire 20 of the basket 30 preferably contains a radiopaque material. By including the radiopaque material in the wire 20, it becomes possible to check the expanded state and position of the basket 30 under X-ray fluoroscopy, which makes it easier to perform the procedure smoothly.

[0065] Next, the method for treating an aneurysm of the present invention will be described. Note that in the following description, parts that overlap with the above description will be omitted.

[0066] The method for treating an aneurysm of the present invention is a method for treating an aneurysm using the medical device 1 of the present invention, and includes the steps of inserting a basket 30 into an artery and expanding the basket 30 within an aneurysm that the artery has, and pushing the basket pusher 40 in the extension direction so that the angle θ1 formed proximally between the extension direction L1 of the basket pusher 40 and a straight line L2 that passes through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is 150 degrees or less.

[0067] In the treatment of an aneurysm of the present invention, a medical device 1 is used, which includes a basket 30 having a plurality of wires 20, a connecting member 80 arranged proximally of the basket 30, and a basket pusher 40 arranged proximally of the connecting member 80, and the connecting member 80 can bend under the weight of the basket 30. In other words, the method for treating an aneurysm of the present invention uses the medical device 1 of the present invention described above.

[0068] The process of inserting a basket 30 having a plurality of wires 20 into an artery and expanding the basket 30 within an aneurysm in the artery specifically involves inserting the basket 30 into an artery having an aneurysm, passing the basket 30 through the opening of the aneurysm to the inside of the aneurysm, and expanding the basket 30 within the aneurysm.

[0069] The step of pushing the basket pusher 40 in the extension direction to set the angle θ1 formed by the extension direction L1 of the basket pusher 40 and the straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 to 150 degrees or less on the proximal side by pushing the basket pusher 40 in the extension direction changes the orientation of the basket 30 expanded within the aneurysm. Specifically, for example, the basket pusher 40 is pushed from the proximal side toward the distal side, and the basket 30 is pushed within the aneurysm along the aneurysm wall by the basket pusher 40, thereby rotating the basket 30 and changing the orientation of the basket 30. As a result, the positions of the distal end and proximal end of the basket 30, where the multiple wires 20 constituting the basket 30 are densely packed, can be changed, making it easier to fit the basket 30 to the aneurysm and to treat the aneurysm.

[0070] In the step of rotating the basket 30 within the aneurysm, the rotation angle of the basket 30 is 150 degrees or less. In other words, the angle θ1 formed on the proximal side between the extension direction L1 of the basket pusher 40 and a straight line L2 passing through the distal end 30d of the basket 30 and the proximal end 30p of the basket 30 is 150 degrees or less. By setting the rotation angle of the basket 30 to 150 degrees or less, the basket 30 can be rotated sufficiently within the aneurysm.

[0071] Furthermore, it is preferable to include a step of placing an elongated medical object inside the basket 30. By rotating the basket 30 inside the aneurysm, the side of the basket 30, where the gaps between the multiple wires 20 constituting the basket 30 tend to be larger, faces the opening of the aneurysm rather than the distal end or proximal end of the basket 30. This makes it easier to place an elongated medical object such as a coil inside the basket 30 during embolization, which is a method for treating aneurysms, and allows for smooth treatment of the aneurysm.

[0072] As described above, the medical device of the present invention includes a basket having multiple wires, a connecting member disposed proximally of the basket, and a basket pusher disposed proximally of the connecting member. The connecting member can bend under the weight of the basket. When the basket and connecting member are immersed in 37°C warm water for two minutes and then a 0.1 g weight is attached distally to the midpoint of the length from the distal end to the proximal end of the basket in the 37°C warm water, the angle formed by the direction of extension of the basket pusher with the basket pusher fixed horizontally and a line passing through the distal and proximal ends of the basket is 150 degrees or less. This configuration of the medical device of the present invention allows the basket to be tilted relative to the basket pusher. Therefore, for example, when the basket is placed inside the aneurysm after passing through the aneurysm opening, the side of the basket can be oriented toward the aneurysm opening. The gaps between the wires in the side portion of the basket tend to be larger than those at the proximal and distal ends of the basket, making it easier to insert long medical objects such as coils into the basket through the gaps between the wires.

[0073] This application claims the benefit of priority based on Japanese Patent Application No. 2022-053544, filed on March 29, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-053544, filed on March 29, 2022, are incorporated herein by reference.

[0074] 1: Medical device 10: Sheath 10d: Distal end of sheath 10p: Proximal end of sheath 20: Wire 20d: Distal end of wire 20p: Proximal end of wire 30: Basket 30d: Distal end of basket 30p: Proximal end of basket 40: Basket pusher 40d: Distal end of basket pusher 51: First binding part 52: Second binding part 80: Connecting member 80d: Distal end of connecting member 80p: Proximal end of connecting member 90: Heating mechanism L1: Extension direction of basket pusher L2: Straight line passing through the distal end and proximal end of the basket θ1: Angle formed proximally between the extension direction of the basket pusher and a straight line passing through the distal end and proximal end of the basket P1: Midpoint of the length from the distal end of the basket to the proximal end of the basket

Claims

1. a basket having a plurality of wires; a connecting member disposed proximally of the basket; a basket pusher disposed proximally of the connecting member, the connecting member is capable of bending under the weight of the basket; The basket is configured to place an elongated medical object therein, A medical device in which the angle formed on the proximal side between the extension direction of the basket pusher and a line passing through the distal end of the basket and the proximal end of the basket is 150 degrees or less, as measured under the following conditions: [conditions] The basket and the connecting member are immersed in 37°C warm water for 2 minutes, and then a 0.1 g weight is connected distal to the midpoint of the length from the distal end of the basket to the proximal end of the basket in the 37°C warm water. With the basket pusher fixed horizontally, the angle formed by the direction of extension of the basket pusher and a straight line passing through the distal end of the basket and the proximal end of the basket is measured.

2. a barrel having a distal end and a proximal end; The medical device of claim 1 , wherein the basket is disposed within the inner lumen of the sheath and is expandable once outside the sheath.

3. The connecting member is separable; The medical device according to claim 1 or 2, wherein the basket is detachable from the basket pusher.

4. a length of the connecting member in an extension direction of the basket pusher is shorter than a length of the basket pusher and a length of the basket; The medical device according to claim 1 or 2, wherein the three-point bending stress of the material constituting the connecting member is lower than the three-point bending stress of the material constituting the basket pusher and the three-point bending stress of the material constituting the basket.

5. the connecting member is located inward of the basket pusher at the distal end of the basket pusher; 3. The medical device of claim 1, wherein in a dry state, the outer diameter of the connecting member is smaller than the outer diameter of the distal end of the basket pusher and the outer diameter of the proximal end of the basket.

6. the connecting member is located outside the basket pusher at the distal end of the basket pusher; 3. The medical device of claim 1, wherein, in a dry state, the outer diameter of the connecting member is greater than the outer diameter of the distal end of the basket pusher and less than the outer diameter of the proximal end of the basket.

7. the material constituting the connection member is a synthetic resin, The medical device according to claim 1 or 2, wherein the material constituting the basket pusher and the basket is metal.

8. The material constituting the connection member has a property of melting when heated, The medical device according to claim 1 or 2, further comprising a heating mechanism for heating the connecting member.

9. The basket includes a first bundling portion at a distal portion thereof that bundles and fixes the plurality of wires, and a second bundling portion at a proximal portion thereof that bundles and fixes the plurality of wires, In a cross section perpendicular to an extension direction of the basket pusher, the connecting member is disposed inside the second binding portion, The medical device according to claim 1 or 2, wherein the wire is disposed outside the connecting member.

10. The medical device of claim 9 , wherein the first tie portion and the second tie portion comprise a radiopaque material.