Delivery device for defect hole closure device

Abstract

This delivery device comprises a cable and an inner tube. The cable is configured to be axially moveable, together with a defect hole closure device, inside a catheter. The inner tube surrounds the cable from the radially outer side and is configured to be moveable inside the catheter independently of the cable. The inner tube has a pressing part that radially expands a second portion when a rear end part is pressed so as to approach an intermediate portion. When the pressing part is made to protrude outside the catheter, the pressing part expands radially, with the axis of the catheter as a reference.

Description

Delivery device for defect closure device

[0001] The present disclosure relates to a delivery device for a defect closure device.

[0002] Patent Literature 1 discloses a medical material for treating an internal opening, typically a defect caused by an atrial septal defect (ASD). This medical material is applied to a catheter-based treatment known as a minimally invasive treatment. The medical material includes a defect closure material for closing the defect and a delivery cable for setting the defect closure material into the defect. The defect closure material is connected to the tip of the delivery cable in advance and housed within the catheter together with the delivery cable. The catheter and delivery cable are inserted into a vein through a small incision and advanced so that the tip reaches an appropriate position at or near the defect. The defect closure material is removed from the catheter at an appropriate position by manipulation outside the body and aligned with the defect. A deforming force is then applied to the defect closure material so that it will remain in place while closing the defect. The defect closure material is then detached from the delivery cable and placed in the body.

[0003] Japanese Patent Application Laid-Open No. 2022-080007

[0004] The defect closure material disclosed in Patent Document 1 is a cylindrical body with a knitted structure made of wires, comprising a distal tubular portion, a proximal tubular portion, and a generally central portion continuous therebetween and having a smaller diameter than the other portions. The distal end of the defect closure material is detachably connected to the distal end of the cable body of the delivery cable, and the delivery cable is passed through the axial direction of the cylindrical body when delivered into the defect. The defect closure material requires that the distal tubular portion be positioned on one side of the bulkhead containing the defect (the side farther from the operator's hand) and the proximal tubular portion be positioned on the other side of the bulkhead (the side closer to the operator's hand), and that both tubular portions be expanded so that their diameters are larger than the defect. When the operator pulls the cable body toward the operator, the distal end of the defect closure material approaches the generally central portion, compressing the distal tubular portion in the axial direction. This causes the distal tubular portion to expand radially. On the other hand, to expand the rear-end tubular portion, it is necessary to apply a pushing force from the proximal side toward the approximate center of the rear-end tubular portion. For this reason, the delivery cable of Patent Document 1 further includes an outer tube that covers the cable main body and is slidable along the cable main body. When the operator pushes the outer tube forward in this state, the tip of the outer tube presses against the rear-end tubular portion, compressing the rear-end tubular portion in the axial direction. This causes the rear-end tubular portion to expand radially.

[0005] In order to properly set the defect closure material into the defect, it is preferable to sufficiently expand the tubular portion at the rear end so that the entire tubular portion at the rear end is as close to the septum as possible. However, since the outer tube is required to be able to be housed in the catheter and to be able to slide relative to the cable body, the configuration of the tip end is subject to significant constraints. For this reason, it may not be easy to sufficiently expand the tubular portion at the rear end.

[0006] The present disclosure aims to provide a delivery device that facilitates sufficient expansion of a defect closure device.

[0007] A delivery device according to a first aspect of the present disclosure includes a defect closure device comprising a first portion having a distal end and adapted to be positioned on one side of a septum having a defect, a second portion having a rear end and adapted to be positioned on the opposite side of the septum from the first portion, and an intermediate portion continuous between the first and second portions, wherein application of a force urging the rear end toward the intermediate portion causes the second portion to be compressed in a direction along an imaginary axis passing through the distal end, the intermediate portion, and the rear end and the second portion to be expanded radially about the imaginary axis. The delivery device is for setting the defect closure device into the defect via a catheter inserted into a bodily passage extending near the defect, and includes a cable and an inner tube. The cable is configured to be connectable to the distal end so as to pass through the distal end, the intermediate portion, and the rear end in this order, and is configured to be movable axially within the catheter together with the defect closure device. The inner tube radially surrounds the cable and is configured to be movable axially within the catheter independently of the cable. The inner tube has a pressing portion configured to radially expand the second portion by pressing the rear end portion toward the intermediate portion, and the pressing portion is configured to radially expand relative to the axis of the catheter when it is removed from the catheter.

[0008] A delivery device according to a second aspect of the present disclosure is the delivery device according to the first aspect, wherein the pressing portion at least partially has a shape that follows the outer shape of the rear end portion.

[0009] A delivery device according to a third aspect of the present disclosure is a delivery device according to the first or second aspect, wherein the maximum diameter of the pressing portion in an expanded state is equal to or greater than the inner diameter of the catheter.

[0010] A device set for closing a defect according to a fourth aspect of the present disclosure comprises a delivery device according to any one of the first to third aspects, and the defect closure device connected to the cable.

[0011] A device set for closing a defect according to a fifth aspect of the present disclosure is the device set for closing a defect according to the fourth aspect, wherein the maximum diameter of the pressing portion in an expanded state is 10% or more of the maximum diameter of the second portion in an expanded state.

[0012] In accordance with the present disclosure, a delivery device is provided that facilitates sufficient expansion of a defect closure device.

[0013] FIG. 1 is a plan view of a device set for defect closure according to one embodiment. FIG. 2 is a plan view of the defect closure device of FIG. 1. FIG. 3 is a diagram illustrating a method of connecting the defect closure device and a delivery device. FIG. 4 is a diagram of the operation section as viewed from the rear. FIG. 5 is a diagram illustrating the configuration of the pressing section. FIG. 6 is a diagram illustrating the operation of the pressing section. FIG. 7 is a diagram illustrating a method of using the device set. FIG. 8 is a diagram illustrating a method of using the device set. FIG. 9 is a diagram illustrating a method of using the device set. FIG. 10 is a diagram illustrating a method of using the device set. FIG. 11 is a diagram illustrating a method of using the device set. FIG. 12 is a diagram illustrating a method of using the device set.

[0014] A delivery device according to one embodiment of the present disclosure and a device set for closure of a defect including the same will be described below with reference to the drawings. For the sake of convenience, some components may be omitted from the drawings. The dimensions of the components shown in the drawings may not necessarily correspond to the actual dimensions of the components. In this embodiment, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to."

[0015] 1. Overview Fig. 1 is a plan view of a device set 1 for closing a cardiac defect according to this embodiment (hereinafter also simply referred to as "device set 1"). Fig. 2 is a plan view of a cardiac defect closure device 2 (hereinafter also simply referred to as "closure device 2") included in the device set 1 of Fig. 1. The device set 1 is used to close and treat an opening in the body. An example of the opening in the body is a congenital atrial defect 50 (see Fig. 7) in an atrial septum 53 (septum) separating the right atrium 52 and the left atrium 51 of the heart 5 due to an atrial septal defect (ASD).

[0016] Treatments for such a defect 50 include surgery and catheterization. Surgery involves opening the chest, stopping the heart using a cardiopulmonary bypass, and either directly closing the defect 50 or using a specialized medical material called a patch. Catheterization involves inserting a catheter containing a defect closure material such as the closure device 2 into the femoral vein, advancing the defect closure material and catheter to an appropriate position near or near the defect 50, and then removing the defect closure material from the catheter, positioning it to close the defect 50, and leaving it in place. The catheter is inserted into the femoral vein through a small incision in the groin. For this reason, catheterization is known for being less invasive and placing less strain on the patient than surgery.

[0017] A known defect closure material is passed through the atrial defect 50, then closes the defect 50 by sandwiching the periphery of the defect 50 from both the left atrium 51 and the right atrium 52, and is then placed (set) in the atrial septum 53. After the defect closure material is set in the atrial septum 53, an intima forms to cover the defect 50, eventually healing the defect 50. To this end, the defect closure material includes a first portion placed in the left atrium 51, a second portion placed in the right atrium 52, and an intermediate portion connected between the first and second portions. The first and second portions each have a spindle shape with a maximum diameter at the intermediate portion and a gradually decreasing diameter from the intermediate portion to both ends. Because the intermediate portion is connected to the reduced-diameter ends of the first and second portions, the defect closure material as a whole has a double spindle shape with narrowed ends and intermediate portions.

[0018] The defect closure material has a mesh structure formed from wire as a whole, and is particularly deformable in the first and second portions. The first and second portions can be radially compressed and deformed into an elongated, approximately cylindrical shape by being stretched longitudinally (along an imaginary axis passing through both ends and the middle portion) to be housed inside the catheter. Furthermore, the first and second portions can be radially expanded outside the catheter to deform into an approximately disk shape to close the defect 50. Here, defect closure materials include those in which the wire is formed from a shape memory alloy and self-expands when extended outside the catheter, and those in which the wire is formed from a bioabsorbable material or the like and requires expansion outside the catheter. The expansion is performed, for example, by applying a force in a longitudinally compressive direction to the first and second portions using a delivery device connected to the defect closure material.

[0019] The closure device 2 according to this embodiment is a defect closure material in which the wire is made of a bioabsorbable material. A delivery device 3 (hereinafter also simply referred to as "device 3"), which constitutes the device set 1 together with the closure device 2, is preferably applied to this closure device 2 and particularly facilitates the expansion of the second portion of the closure device 2. The configurations of the closure device 2 and device 3 will be specifically described below. Note that the arrows defined in FIG. 1 represent the axial direction of the device set 1, with "tip" indicating a direction closer to the defect 50 (or a direction farther from the operator's hand) and "rear" indicating a direction farther from the defect 50 (or a direction closer to the operator's hand). The following explanation will be based on the directions defined in FIG. 1.

[0020] 2. Occlusion Device As shown in Fig. 2, the occlusion device 2 includes a first portion 21 having a distal end portion 210, a second portion 22 having a proximal end portion 220, and an intermediate portion 20 continuous between the first portion 21 and the second portion 22. As already described, the first portion 21 and the second portion 22 each have a spindle shape in which the diameter is greatest at the intermediate portion and gradually decreases from the intermediate portion toward both ends. As a result, the occlusion device 2 has a double spindle shape in which the diameter is narrowed at the distal end portion 210, the intermediate portion 20, and the proximal end portion 220 and increases in diameter near the centers of the first portion 21 and the second portion 22. The occlusion device 2 according to this embodiment has a mesh structure formed by knitting wires 2A, except for the distal end portion 210.

[0021] When the closure device 2 is applied to close the cardiac defect 50, the first portion 21, the intermediate portion 20, and the second portion 22 are configured to be disposed in the left atrium 51, the cardiac defect 50, and the right atrium 52, respectively. The first portion 21 and the second portion 22 are each configured so that their maximum diameters are equal to or smaller than the inner diameter of the catheter 4 when radially compressed to be housed within the catheter 4 (described below). The first portion 21 and the second portion 22 are each configured so that their maximum diameters are 5 mm to 80 mm, preferably 15 mm to 25 mm, when expanded into a disk shape outside the catheter. The maximum diameter is the diameter of the smallest circle that encloses all of the peripheries of the first portion 21 or the second portion 22 when folded along an imaginary axis. The first portion 21 and the second portion 22 may be configured so that their maximum diameters when expanded are the same or different.

[0022] The distal end portion 210 is a substantially cylindrical portion coupled to the wire 2A. As shown in FIG. 3 , a screw groove 2100 is formed inside the distal end portion 210. As a result, the distal end portion 210 functions as a coupling portion for coupling to a coupled portion 310 formed at the distal end of a cable 31 of the device 3 (described later). The coupled portion 310 is formed with a thread 3100 that threadably engages with the screw groove 2100. When the screw groove 2100 and the thread 3100 are aligned and the cable 31 is rotated in a predetermined direction relative to the closure device 2, the coupled portion 310 advances toward the interior of the distal end portion 210, and the closure device 2 and the cable 31 are coupled. On the other hand, when the cable 31 is rotated in the opposite direction relative to the closure device 2, the coupled portion 310 retreats relative to the distal end portion 210, and the closure device 2 and the cable 31 are released from each other.

[0023] The closure device 2 is configured so that the cable 31 passes through the tip portion 210, the intermediate portion 20, and the rear end portion 220 in this order. The intermediate portion 20 and the rear end portion 220 are not fixed to the cable 31, but surround the cable 31 from the radially outer side while leaving a gap large enough to allow the cable 31 to move axially on the outer circumferential surface of the cable 31. As a result, the imaginary axis of the closure device 2 passing through the tip portion 210, the intermediate portion 20, and the rear end portion 220 generally coincides with the axis of the cable 31. Furthermore, when the closure device 2 is housed in the catheter 4, the imaginary axis generally coincides with the axis of the catheter 4.

[0024] The configuration of the wire 2A is not particularly limited, but examples include monofilament yarn, multifilament yarn, twisted yarn, braided cord, etc. Among these, monofilament yarn is preferred. The diameter of the wire 2A is approximately 0.001 mm to 1.5 mm. The density (opening size) of the mesh structure is not particularly limited, and may be any density suitable for catheter treatment.

[0025] Examples of bioabsorbable materials constituting the wire 2A include polyglycolic acid, polylactide, polycaprolactone, glycolic acid-lactide copolymer, glycolic acid-ε-caprolactone copolymer, lactide-ε-caprolactone copolymer, poly-p-dioxanone, glycolic acid-lactide-ε-caprolactone copolymer, etc. Examples of lactides include L-lactide, D-lactide, D,L-lactide, and stereocomplexes of L-lactide and D-lactide. Metal markers may be included in appropriate locations in the mesh structure formed by the wire 2A. This makes it easy to monitor the shape and position of the closure device 2 using imaging, X-rays, or other methods.

[0026] The tip portion 210 may be made of a bioabsorbable material or other materials. Examples of bioabsorbable materials that make up the tip portion 210 include those exemplified for the wire 2A, as well as polysaccharides such as starch, alginic acid, hyaluronic acid, chitin, pectinic acid and derivatives thereof, proteins such as gelatin, collagen, albumin, and fibrin, and biodegradable inorganic materials such as magnesium and magnesium alloys. Examples of materials other than bioabsorbable materials include metals such as stainless steel.

[0027] 3. Device The device 3 includes a cable 31 having a connectable portion 310 at its tip, an operating portion 32 attached midway along the cable 31, and an inner tube 30 fixed to the tip of the operating portion 32. The cable 31 is made of metal. As described above, the cable 31 has the connectable portion 310 with a screw thread 3100 formed at its tip, and is configured to be connectable to the tip portion 210 of the closure device 2. This allows the cable 31 to move within the catheter 4 together with the closure device 2 in the axial direction of the catheter 4. Note that the cable 31 according to this embodiment has a double structure including a cable core 311 and a sheath 312 surrounding the cable core 311 (see FIG. 4 ) to provide both flexibility and resistance to twisting, and the screw thread 3100 is formed on the cable core 311. Therefore, the tip portion 210 and the connectable portion 310 can be attached and detached by rotating only the cable core 311.

[0028] FIG. 4 is a rear view of the operation unit 32. The operation unit 32 is a portion that an operator (typically a doctor) grasps to operate the device set 1 outside the body. The operation unit 32 includes an operation screw 320 and a main body 321. The main body 321 according to this embodiment has a cylindrical shape as a whole and is configured so that the cable 31 passes through it in the axial direction. The main body 321 is formed with a hole 322 that extends in the radial direction and communicates with the axial through-hole through which the cable 31 passes. A screw groove 3220 is formed on the inner circumferential surface of the hole 322, and the operation screw 320 is formed with a thread 3200 that threadably engages with the screw groove 3220. When the screw groove 3220 and the thread 3200 are aligned and the operation screw 320 is rotated in a predetermined direction, the operation screw 320 advances deeper into the hole 322, and its tip presses against the outer circumferential surface of the cable 31. This restricts the movement of the cable 31 relative to the main body 321. On the other hand, when the operating screw 320 is rotated in the opposite direction to the above, the operating screw 320 moves away from the cable 31, allowing the cable 31 to move relative to the main body 321. The main body 321 is made of, but is not limited to, a hard synthetic resin. The operating screw 320 is made of, but is not limited to, a metal.

[0029] The inner tube 30 is a cylindrical member that surrounds the cable 31 from the outside in the radial direction as a whole, and has a main body portion 301 that extends in the axial direction, and a pressing portion 300 formed at the tip of the main body portion 301. The inner diameter of the inner tube 30 is larger than the outer diameter of the cable 31, and is configured to be movable relative to the cable 31. Meanwhile, the inner tube 30 is configured so that the entire inner diameter can be accommodated inside the catheter 4, and is configured to be movable relative to the catheter 4.

[0030] The rear end of the main body 301 is fixed to the tip of the operating unit 32. When the operating unit 32 is movable relative to the cable 31, moving only the operating unit 32 in the axial direction relative to the cable 31 causes the inner tube 30 to move in the axial direction accordingly. This allows the inner tube 30 to move axially inside the catheter 4 independently of the cable 31.

[0031] The outer diameter of the main body 301 is smaller than the inner diameter of the catheter 4. The wall thickness of the main body 301 is preferably 0.1 mm to 2 mm. The main body 301 according to this embodiment is made of a flexible tubing material. Examples of materials that can be used for the tubing material include polytetrafluoroethylene (PTFE), polyamide (PA), polyether block amide (PEBA), and polyethylene (PE).

[0032] FIG. 5 is a diagram showing the configuration of the pressing unit 300. The pressing unit 300 faces the rear end 220 of the closure device 2 and is configured to radially expand the second section 22 by pressing the rear end 220 of the closure device 2, which has been extended from the catheter 4, toward the intermediate section 20. The pressing unit 300 according to this embodiment is made of a flexible synthetic resin tube material and is fixed to the distal end of the main body section 301. The tube material is not particularly limited, but may be the same as the tube material constituting the main body section 301, and the outer diameter and wall thickness may also be the same as those of the main body section 301. However, in addition to the tube material, the pressing unit 300 may also include a frame structure for facilitating deformation, as described below. The frame structure may be, for example, a leaf spring, a wire or mesh made of a shape-memory alloy such as a titanium-nickel alloy, or the like. In other words, the pressing unit 300 may be made of a single material, or may be made of a combination of different materials, such as a synthetic resin and a shape-memory alloy.

[0033] The pressing portion 300 differs from the main body portion 301 in that multiple slits 3000 (reference numerals are only given to representative ones) are formed on the side surface. In this embodiment, the slits 3000 each extend linearly along the axial direction. However, the slits 3000 may each extend at an angle to the axial direction or may extend in a curved line. Furthermore, the spacing and number of the slits are not particularly limited, as long as they have enough strength to appropriately press the rear end portion 220. Furthermore, the pressing portion 300 may be subjected to a shape-memory treatment, such as heat setting, to promote deformation, as described below.

[0034] The pressing unit 300 is configured to expand radially with respect to the axis of the catheter 4 by being pressed by the main body 301 when it is pushed out of the catheter 4 by the multiple slits 3000 (in other words, when it is not constrained in the radial direction). Figure 6 is a diagram illustrating the operation of the pressing unit 300 when the second section 22 is placed in the right atrium 52 by the operation described below. In the state (1), the operating unit 32 is pushed forward relative to the cable 31, causing the pressing unit 300 and a portion of the main body 301 to be pushed out of the catheter 4. In the state (1), the pressing unit 300 is not pressing against the rear end 220, and the slits 3000 are also closed.

[0035] When the operating unit 32 is further pushed out from the state (1), the state changes to state (2). In state (2), the main body 301 is further pushed out of the catheter 4, and the pressing unit 300 presses the rear end 220 toward the intermediate portion 20. The second portion 22 is compressed in the imaginary axial direction between the atrial septum 53 and the pressing unit 300, and expands radially. Furthermore, the slits 3000 in the pressing unit 300 open, and a bending force acts on the area between adjacent slits 3000, forming a peripheral portion 3001. This causes the pressing unit 300 to expand radially.

[0036] If the operating unit 32 is further pushed out from the state (2), the state changes to state (3). In state (3), the second portion 22 is further compressed between the atrial septum 53 and the pressing portion 300, expanding radially to form a generally disk-like shape. At this time, the central portion of the second portion 22 tends to be thicker in the imaginary axial direction than the peripheral portion, so the rear end portion 220 has an outer shape in which the central portion bulges toward the pressing portion 300 more than the other portions. The central portion of the pressing portion 300 (the end face of the tubing and its vicinity) is less likely to advance due to resistance from the second portion 22, but a relatively large bending force acts on the portion between adjacent slits 3000. As a result, the peripheral portion 3001 comes into contact with the rear end portion 220 and presses the rear end portion 220 over a wider radial range. As described above, the pressing portion 300 deforms to at least partially assume a shape that conforms to the outer shape of the rear end portion 220 when pressed (more specifically, a shape that expands radially outward as it moves from the rear side to the front side).

[0037] When the operating unit 32 is retracted from the state (3), the pressing unit 300 retracts so as to move away from the expanded second portion 22. At this time, the pressing unit 300 recovers to a certain extent from the shape of (3) and contracts radially. When the pressing unit 300 returns to the inside of the catheter 4, the peripheral edge 3001 interferes with the tip 40 of the catheter 4, applying a force that closes the slit 3000. In this way, the pressing unit 300 contracts radially and is accommodated again in the catheter 4 in the shape of (1) or a shape close to it.

[0038] The maximum diameter of the pressing portion 300 in its expanded state is preferably equal to or larger than the inner diameter of the catheter 4. The maximum diameter of the pressing portion 300 is the diameter of the smallest circle that surrounds all of the peripheral portions 3001 when the pressing portion 300 is compressed in the axial direction and the axial positions of both ends of the multiple slits 3000 are aligned. Note that, for example, if the slits 3000 do not extend parallel to the axial direction, such as extending spirally in the axial direction, the pressing portion 300 does not necessarily need to be compressed so that both ends of the same slit 3000 are aligned; it is sufficient that the positions of both ends of the slit 3000 as a whole are aligned. Furthermore, the maximum diameter of the pressing portion 300 is preferably 10% or more, more preferably 50% or more, and even more preferably 100% or more of the maximum diameter of the second portion 22 in its expanded state. On the other hand, if the maximum diameter of the pressing portion 300 increases, a length of the cable 31 sufficient to expand the pressing portion 300 is required. For this reason, it is preferable that the maximum diameter of the pressing portion 300 be 300% or less of the maximum diameter of the second portion 22 in the expanded state. Note that, if the length of the plurality of slits 3000 is increased, the maximum diameter of the pressing portion 300 increases, and if the length of the plurality of slits 3000 is decreased, the maximum diameter of the pressing portion 300 decreases. In this way, the maximum diameter of the pressing portion 300 can be easily adjusted.

[0039] <4. Catheter> The catheter 4 is a medical material used together with the device set 1, and a known catheter can be appropriately selected depending on the treatment method and the patient. The size of the catheter 4 is selected according to the diameter of the vein to be inserted, and is preferably 6 Fr or more and 14 Fr or less (outer diameter 2.000 mm or more and 4.667 mm or less). The inner diameter of the catheter 4 is preferably 1.000 mm or more and 4.167 mm or less. The wall thickness of the catheter 4 can be, for example, 0.25 mm to 0.5 mm. The catheter 4 may be inserted into the vein simultaneously with the device set 1, or may be inserted into the vein and set in a predetermined position before using the device set 1.

[0040] 7 to 10, a method of using the device set 1 according to this embodiment will be described below. The following describes an example in which the closure device 2 is set in the atrial septum defect 50 in the atrial septum 53 of the heart 5 using the device 3. In this example, the catheter 4 is inserted in advance into the femoral vein from the groin, and the tip 40 is set so as to be located near the end of the inferior vena cava 54 and at a predetermined position before the atrial septum defect 50. There is no need to change the position of the catheter 4 while the device set 1 is being used.

[0041] As described above, the closure device 2 is connected at the distal end 210 to the connected portion 310 of the cable 31, and is housed in the catheter 4 from the rear end 41 (outside the body) of the catheter 4 with the cable 31 passing along the imaginary axis. Also, at least a portion of the inner tube 30 is housed in the catheter 4 so as to follow the rear end portion 220 of the closure device 2. This state is the state in which the device set 1 is set in the catheter 4.

[0042] Next, while the relative positions of the cable 31 and the inner tube 30 are fixed (with the operating screw 320 of the operating section 32 tightened), the cable 31 and the inner tube 30 are advanced toward the tip 40 of the catheter 4 (Figure 7).

[0043] Next, from the state shown in Fig. 7, the cable 31 and the inner tube 30 are further advanced while maintaining the catheter 4 in its original position. As a result, the closure device 2 and a portion of the inner tube 30 are pushed out of the catheter 4 through the distal end 40 of the catheter 4. The closure device 2 is positioned so that the first portion 21 of the closure device 2 is located in the left atrium 51, the second portion 22 is located in the right atrium 52, and the intermediate portion 20 is located around the periphery of the cardiac defect 50 (Fig. 8).

[0044] Next, the operating screw 320 of the operating unit 32 is loosened, and the cable 31 is pulled proximally relative to the operating unit 32, thereby retracting the cable 31. As the cable 31 is retracted, the distal end 210 of the closure device 2 approaches the intermediate section 20, and the first section 21 is compressed in the imaginary axial direction. As a result, the first section 21 expands radially and becomes substantially disk-shaped, thereby closing the ventricle defect 50 from the left atrium 51 side ( FIG. 9 ).

[0045] Next, while maintaining the position of the cable 31, the operating portion 32 is pushed from the proximal side to advance the inner tube 30. As described above, the pressing portion 300 of the inner tube 30 also expands radially, pressing the rear end 220 of the second portion 22 and compressing the second portion 22 in the imaginary axial direction. This causes the second portion 22 to expand radially and become approximately disk-shaped, closing the defect 50 from the right atrium 52 side ( FIG. 10 ). In FIG. 10 , the first portion 21 and the second portion 22 have expanded sufficiently large relative to the size of the defect 50, and the closure device 2 is securely set in the defect 50. Furthermore, the first portion 21 and the second portion 22 are aligned with the atrial septum 53 over a wider area, promoting the formation of an intima that heals the defect 50.

[0046] After setting the closure device 2 as shown in Figure 10, the cable 31 is rotated in a predetermined direction to release the connection between the tip portion 210 and the connected portion 310. Then, the operating screw 320 of the operating portion 32 is tightened again, and both the cable 31 and the inner tube 30 are pulled toward the operator's hand and retracted toward the tip 40 of the catheter 4. By storing the pressing portion 300 inside the catheter 4 and further retracting the cable 31 and the inner tube 30, the device 3 can be removed from the body and recovered.

[0047] 6. Features (1) The device 3 according to the above embodiment can easily expand a closure device 2 (atrial defect closure material) that requires an expansion operation of the second portion 22 disposed on the proximal side of the atrial septum 53 (septum). One possible method for expanding the second portion 22 of the closure device 2 is to use the catheter 4 to press the rear end 220. However, when the catheter 4 is inserted into the inferior vena cava 54, the direction of extension of the inferior vena cava 54 is offset from the direction of the atrial septum 53, making it difficult for the distal end 40 of the catheter 4 to access the second portion 22 disposed in the atrial defect 50. Furthermore, once the catheter 4 is positioned appropriately, it is preferable not to move it during treatment. In this regard, the device 3 allows the second portion 22 to be expanded by the cable 31 and the inner tube 30 while maintaining the position of the catheter 4, which is preferable from the perspective of the treating physician.

[0048] (2) According to the device 3 of the above embodiment, the pressing portion 300 is configured to be radially expandable outside the catheter 4. Therefore, the maximum diameter of the pressing portion 300 can be configured to be sufficiently large without being restricted by the size of the catheter 4. As shown in FIG. 10 , the closure device 2 is preferably placed with both the first portion 21 and the second portion 22 aligned with the atrial septum 53. In this regard, the first portion 21 is compressed as a whole in the imaginary axial direction by pulling the cable 31 connected to the distal end portion 210, so that the peripheral portion can be relatively easily aligned with the atrial septum 53. On the other hand, if only the center of the second portion 22 is pressed with a thin tubular member 300X, as shown in the schematic diagram of FIG. 11 , no pressing force is applied to the peripheral portion of the second portion 22, and the peripheral portion may rise relatively above the atrial septum 53. In this regard, the pressing portion 300 can press the second portion 22 over a wider range in the radial direction, and therefore the second portion 22 can be more reliably aligned with the atrial septum 53. The above effect becomes more pronounced when the maximum diameter of the pressing portion 300 is 10% or more of the maximum diameter of the second portion 22. Furthermore, the above effect becomes more pronounced when the pressing portion 300 at least partially has a shape that widens radially outward from the rear side to the front side so as to follow the outer shape of the rear end portion 220.

[0049] (3) The closure device 2 according to the above embodiment is primarily composed of synthetic polymer wires 2A. Therefore, when the closure device 2 is radially expanded, its peripheral edge is softer than that of metal, making it highly unlikely to injure tissue. Furthermore, since the closure device 2 is primarily composed of a bioabsorbable material, it will eventually decompose in the body. Therefore, the likelihood of problems occurring after placement is extremely low.

[0050] 7. Modifications Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present disclosure. For example, the following modifications are possible. Furthermore, the gist of the following modifications can be combined as appropriate.

[0051] (1) The inner cylinder 30 may not be fixed to the operating portion 32 and may be configured to move in the axial direction independently of the operating portion 32. Also, the operating portion 32 may be omitted.

[0052] (2) The connection between the tip portion 210 and the connected portion 310 is not limited to a screw type, but may be a snap type, or may be a type that uses a magnet or a magnetic material.

[0053] (3) The configuration of the pressing portion 300 is not limited to that of the above embodiment. Any configuration may be used as long as it can expand radially outside the catheter 4 to press the second portion 22 and then be re-inserted into the catheter 4. For example, as shown in FIG. 12 , the pressing portion 300 can be formed by folding a sheet-like member in an accordion-like manner to form multiple peaks and valleys, and bundling the rear end portion so that it is smaller than the inner diameter of the catheter 4. This configuration allows the pressing portion 300 to expand in a generally fan-like shape outside the catheter 4 and press up to the periphery of the rear end portion 220. This type of expansion method is also an example of "expanding radially" in the present disclosure. The sheet-like member can be, for example, a plastic film. It is preferable that a cylindrical portion through which the cable 31 passes is formed in the center of the sheet-like member. The tip of the pressing portion 300 can be adjusted to at least partially conform to the outer shape of the rear end portion 220 by, for example, cutting it as needed. The maximum diameter of such a pressing portion 300 is the diameter of a circle circumscribing the shape of the pressing portion 300 when viewed from the distal end side in a state where the expansion of the pressing portion 300 is not restricted.

[0054] (4) Furthermore, as shown in Fig. 13 , the pressing portion 300 may be configured in an umbrella shape that is folded to form pleats when housed in the catheter 4 and self-expands when removed from the catheter 4, widening in diameter from the main body portion 301 toward the second portion 22. Such a pressing portion 300 may be configured, for example, by combining a plastic film and a shape-memory alloy. The shape of the tip of the pressing portion 300 may be formed to at least partially follow the outer shape of the rear end portion 220. The maximum diameter of such a pressing portion 300 is the diameter of a circle circumscribing the shape of the pressing portion 300 when viewed from the tip side when the expansion of the pressing portion 300 is not restricted.

[0055] (5) The pressing portion 300 may also be formed in a brush-like shape on the main body portion 301 side, with a plurality of thin wires bundled together. When such a pressing portion 300 is extended outside the catheter 4, the tips of the wire bundle expand and can press the second portion 22. The material constituting the wires is not particularly limited. The tip of the pressing portion 300 can also be adjusted to at least partially follow the outer shape of the rear end portion 220 by, for example, appropriately cutting the wires. The maximum diameter of such a pressing portion 300 is the diameter of a circle circumscribing the shape of the pressing portion 300 when viewed from the tip side when the expansion of the pressing portion 300 is not restricted.

[0056] (6) The device set 1 according to the above embodiment can be applied to other openings besides the defect 50 caused by ASD. For example, it can be applied to closing openings in tissue-forming septa, such as patent foramen ovale, ventricular septal defect, patent ductus arteriosus, and arteriovenous fistula. Furthermore, the catheter 4 is not limited to being inserted into a vein, and can be inserted into any suitable internal passageway depending on the opening to be treated.

[0057] (7) Although the closure device 2 according to the above embodiment is primarily made of a bioabsorbable material, the closure device 2 may be primarily made of another material. In other words, the closure device 2 may be any material that requires an operation to radially expand the second portion 22 after being removed from the catheter 4.

[0058] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples.

[0059] A sample 1Y of the device set 1 according to the above embodiment and a catheter 4Y were prepared. As shown in FIG. 14A , the sample 1Y included a closure device 2Y and a delivery device 3Y. The configurations of the closure device 2Y and the delivery device 3Y were similar to those of the above embodiment. As shown in FIG. 15 , the pressing portion 300Y of the delivery device 3Y was composed of a flexible synthetic resin tube with multiple linear slits extending in the axial direction. The outer diameter of this tube was larger than the outer diameter of the inner tube and smaller than the inner diameter of the catheter 4Y. The closure device 2Y, the pressing portion 300Y of the delivery device 3Y, and a portion of the inner tube 30Y were housed within the catheter 4Y, and it was confirmed that they slid smoothly within the catheter 4Y.

[0060] Next, a synthetic resin plate 53Y with a through hole 50Y formed therein was prepared. The plate 53Y was fixed upright on a horizontal surface to simulate a septum with a defect hole. The delivery device 3Y was then operated to push the closure device 2Y out from the tip of the catheter 4Y. The closure device 2Y was then positioned so that the first portion 21Y of the closure device 2Y was located at the rear side of the plate 53Y, the second portion 22Y was located at the front side of the plate 53Y, and the middle portion 20Y was located at the through hole 50Y, resulting in the state shown in FIG. 14A . From this state, the cable of the delivery device 3Y was pulled toward the front, radially expanding the first portion 21Y of the closure device 2Y, resulting in the state shown in FIG. 14B . From the state shown in FIG. 14B , the inner tube 30Y and the pressing portion 300Y of the delivery device 3Y were advanced until they came into contact with the second portion 22Y, resulting in the state shown in FIG. 14C . The inner cylinder 30Y is further advanced from the state shown in FIG. 14C, and the pressing portion 300Y is expanded in the radial direction to press the second portion 22Y, thereby achieving the state shown in FIG. 14D.

[0061] 14D , it was confirmed that the second portion 22Y was expanded to its maximum diameter by the pressing portion 300Y. It was also confirmed that the pressing portion 300Y was expanded to its maximum diameter. At this time, the maximum diameter of the pressing portion 300Y was 130% of the maximum diameter of the second portion 22Y.

[0062] Thereafter, the inner tube 30Y was retracted, and the pressing portion 300Y was housed in the catheter 4Y. At this time, it was confirmed that the pressing portion 300Y was compressed in the radial direction in conjunction with the movement of the inner tube 30Y, and could be housed in the catheter 4Y without any problems.

[0063] The above experiments confirmed that the delivery device according to the above embodiment operates without any problems and can easily and sufficiently expand the closure device.

[0064] DESCRIPTION OF SYMBOLS 1 Device set 1Y Sample 2, 2Y Closure device (defect closure device) 3, 3Y Delivery device 4, 4Y Catheter 20, 20Y Intermediate portion 21, 21Y First portion 22, 22Y Second portion 30, 30Y Inner tube 31 Cable 32 Operation portion 50 Defect 51 Left atrium 52 Right atrium 300, 300Y Pressing portion

Claims

1. A delivery device for setting a defect closure device in a defect via a catheter inserted into an internal passage extending near the defect, the delivery device comprising: a first portion having a tip portion and adapted to be placed on one side of a septum having a defect; a second portion having a rear end portion and adapted to be placed on the opposite side of the septum from the first portion; and an intermediate portion continuous between the first and second portions, wherein application of a force urging the rear end portion toward the intermediate portion causes the second portion to be compressed in a direction along an imaginary axis passing through the tip portion, the intermediate portion, and the rear end, and the second portion to be expanded in a radial direction centered on the imaginary axis, the delivery device comprising: a cable configured to be connectable to the tip portion so as to pass through the tip portion, the intermediate portion, and the rear end in that order, and configured to be movable in the axial direction of the catheter together with the defect closure device inside the catheter; and an inner tube radially outside the cable and configured to be movable in the axial direction of the catheter inside the catheter independently of the cable, a pressure portion configured to radially expand the second portion by pressing the rear end portion toward the intermediate portion, the pressure portion configured to radially expand relative to an axis of the catheter when the inner tube is removed from the catheter, the delivery device.

2. The delivery device according to claim 1, wherein the pressing portion at least partially has a shape that conforms to the outer shape of the rear end portion.

3. The delivery device according to claim 1 or 2, wherein the maximum diameter of the pushing portion in an expanded state is equal to or greater than the inner diameter of the catheter.

4. A device set for closing a defect, comprising: a delivery device according to claim 1 or 2; and a defect closure device connected to the cable.

5. A device set for closing a defect hole according to claim 4, wherein the maximum diameter of the pressing portion in an expanded state is 10% or more of the maximum diameter of the second portion in an expanded state.

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