Delivery device

Abstract

To provide a delivery device capable of suppressing positional deviation of a cover covered on a stent body.SOLUTION: A delivery device includes: an indwelling device having a self-expandable stent body 14; and a delivery catheter separably supporting the indwelling device. The delivery catheter is provided with: a cover 34 covering at least a part of an axial direction range of the stent body 14; and an expansion constraining mechanism 50 having a plurality of restraining wires 52 constraining expansion of the stent body 14 by a stent wire 14c composing the stent body 14 being hung. The plurality of restraining wire 52 can release expansion of the stent body 14 by moving in an axial direction.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a delivery device for delivering an implant to a target site in the body.

Background Art

[0002] Patent Document 1 discloses a delivery device including a self-expandable stent body and a delivery catheter that separably supports the stent body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to restrain the expansion of the stent body, a cover may be coated on the stent body. When the stent body is covered with a cover, the axial end of the cover may be displaced inward in the axial direction due to the expansion force of the stent body, and a part of the stent body may be unintentionally exposed and then expanded. If a part of the stent body is unintentionally expanded, it will become an obstacle when delivering the implant into the body.

[0005] Therefore, one of the objects of the present disclosure is to provide a delivery device capable of suppressing the displacement of the cover covered on the stent body.

Means for Solving the Problems

[0006] The delivery device of the present disclosure includes an indwelling device having a self-expandable stent body and a delivery catheter that separably supports the indwelling device. The delivery catheter includes a cover that covers at least a partial axial range of the stent body, and an expansion restraint mechanism having a plurality of restraint wires that restrain the expansion of the stent body by being hooked by the stent wires constituting the stent body. The plurality of restraint wires can release the restraint of the stent body by moving in the axial direction.

Advantages of the Invention

[0007] According to the present disclosure, displacement of the cover covering the stent body can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0009] (First Embodiment) Hereinafter, embodiments for implementing the delivery device of the present disclosure will be described. The same or equivalent elements are denoted by the same reference numerals, and duplicate descriptions will be omitted. In each drawing, for the sake of convenience of explanation, components are appropriately omitted, enlarged, or reduced. The drawings are to be viewed in accordance with the orientation of the reference numerals.

[0010] Referring to Fig. 1. The delivery device 10 is used to deliver the implant 12 to a target site in the body. The delivery device 10 includes an implant 12 having a self-expandable stent body 14 and a delivery catheter 16 that separably supports the implant 12. In this specification, the direction along the axis of the shaft 30 of the delivery catheter 16 is simply referred to as the axial direction, and the radial direction and the circumferential direction centered on the axis are simply referred to as the radial direction and the circumferential direction. Also, the side away from the handle 32 of the delivery catheter 16 in the axial direction of the shaft 30 is referred to as the distal end side, and the side opposite to it in the axial direction is referred to as the proximal end side.

[0011] Refer to FIGS. 2 and 3. The indwelling device 12 is indwelled at a target site in the body for treatment. Here, an example will be described in which the indwelling device 12 is used for treating aortic dissection of the thoracic aorta 18. In this case, the treatment of aortic dissection is performed by pressing the intima of the aortic dissection part against the adventitia by the stent body 14 of the indwelling device 12. The use of the indwelling device 12 is not limited to this, and it may be used for various treatments such as aneurysms and gastrointestinal obstructions. Specific examples of the living body organs to be treated are not particularly limited either. In addition to the thoracic aorta 18, it may be used for various arteries such as the abdominal aorta, iliac artery, and femoral artery, as well as the gastrointestinal tract, etc.

[0012] The surgical procedure using the delivery device 10 of the present embodiment will be described by taking the OSG (open stent grafting) method involving thoracotomy of the living body as an example. This OSG method is a surgical procedure in which, after thoracotomy of the chest of the living body, the indwelling device 12 is inserted from the incision site into the thoracic aorta using the delivery device 10. The surgical procedure using the delivery device 10 is not particularly limited, and it may be adopted in various surgical procedures such as the EVAR (EndoVascular Aneurysm Repair) method and the TEVAR (Thoracic EndoVascular Aortic Repair) method that do not involve thoracotomy or laparotomy of the living body.

[0013] The stent body 14 includes at least one self-expandable stent 20. Here, "self-expansion" means expanding radially outward due to the restoring force accompanying the elastic deformation of the stent 20. The stent body 14 can maintain a state of being attached to the inner cavity surface of a living organ by the self-expansion force of the stent 20. The stent 20 of the present embodiment is constituted by a braided stent knitted in a net-like and cylindrical shape using wire elements 20a. As the material of the wire elements 20a, for example, in addition to metals such as shape memory alloys and stainless steel, resins and the like can be adopted. The stent body 14 of the present embodiment is constituted by a bare stent using a braided stent. Here, the bare stent refers to a stent that is not connected to a graft and is exposed. The stent body 14 may be constituted by a stent graft including at least one stent 20 and a graft to which the stent 20 is connected instead of the bare stent. When the stent body 14 is constituted by a stent graft, a specific example of the stent 20 is not limited to a braided stent and may be constituted by a Z-stent or the like.

[0014] The indwelling device 12 optionally includes a cylindrical body 24 disposed on the proximal side with respect to the stent body 14 and connected to the stent body 14. The cylindrical body 24 includes a cuff 26 provided at the distal end portion of the cylindrical body 24 and a graft 28 provided on the proximal side of the cuff 26. The cuff 26 is disposed inside the peripheral edge of the opening provided at the incision site of the thoracic aorta 18 (living organ) and serves as a suture allowance when anastomosing the graft 28 to the peripheral edge of the opening. The graft 28 is a flexible cylindrical member that forms a fluid flow passage for body fluids such as blood inside. The graft 28 of the present embodiment is used as an artificial blood vessel to be replaced at a partial resection site (lesion site) of the thoracic aorta 18. A part of the proximal end portion 14d of the stent body 14 is inserted inside the cylindrical body 24 (cuff 26) and then connected by suturing or the like.

[0015] Refer to FIG. 4. FIG. 4 is a development view showing a part of the shape obtained by axially cutting open a part of the braided stent constituting the stent body 14 and then developing it in a plane. The braided stent is formed by arranging unit patterns 20b composed of wire elements 20a in a row in the axial direction. The unit pattern 20b is composed of wire elements 20a that progress in a wave shape in the circumferential direction. The unit pattern 20b of the present embodiment is composed of wire elements 20a that make two circumferences in the circumferential direction, and the phase of the wave formed by the wire elements 20a of each circumference is shifted by half a pitch in the circumferential direction. The wire element 20a constituting the braided stent is provided with a bent portion 20c that folds back in the axial direction in the circumferential direction. The bent portions 20c formed by the wire elements 20a constituting adjacent unit patterns 20b are connected by hooking each other. The knitting pattern using the wire element 20a here is an example, and its specific example is not particularly limited. Here, a knitting pattern using a single wire element 20a is shown, but a knitting pattern using a plurality of wire elements 20a may also be used.

[0016] Refer to FIGS. 1 and 5. The delivery catheter 16 includes a shaft 30 that is inserted into the body at least at the tip side portion, a handle 32 that is attached to the proximal end side portion of the shaft 30 and is gripped by an operator, a cover 34 that covers a part of the axial range of the stent body 14, and a tension mechanism 36 that pulls the cover 34 in the axial direction.

[0017] Refer to FIGS. 5 and 6. The shaft 30 has flexibility that allows it to be bent and deformed. At least a part of the shaft 30 is inserted into the stent body 14 of the indwelling device 12. A hollow portion 30a that penetrates in the axial direction is formed inside the shaft 30, and a tip opening 30b that is part of the hollow portion 30a opens at the tip of the shaft 30.

[0018] The cover 34 is a cylindrical body made of a soft material. By covering at least a part of the axial range of the stent body 14, the cover 34 maintains the axial range in a contracted state. The cover 34 of the present embodiment is covered only in a part of the axial range of the stent body 14, but may be covered in the entire axial range of the stent body 14. When the cover 34 of the present embodiment is in a state of being covered on the stent body 14, it has a double structure in which a part of the cylindrical member is folded back inward. In addition to the cylindrical outer peripheral portion 34a that covers the stent body 14 from the radially outer side, this cover 34 includes an inner portion 34b inserted inside the stent body 14 and a folded-back portion 34c that connects the outer peripheral portion 34a and the inner portion 34b. The folded-back portion 34c is folded back axially on the tip side of the shaft 30. The outer diameter of the outer peripheral portion 34a of the cover 34 of the present embodiment gradually decreases toward the tip side (see FIG. 1). The outer diameter R24 of the tip of the cylindrical body 24 used for the indwelling device 12 is larger than the maximum outer diameter R34 of the outer peripheral portion 34a of the cover 34. Here, the maximum outer diameter R34 refers to the largest outer diameter in the entire axial range of the outer peripheral portion 34a of the cover 34.

[0019] The tension mechanism 36 performs an exposure operation of exposing the covered portion of the stent body 14 by the cover 34 by pulling the cover 34 in the axial direction. The tension mechanism 36 includes a first operation member 38 that receives an exposure operation Da by an operator for the exposure operation of the stent body 14, and a first traction member 40 that pulls the cover 34 toward the proximal end side in conjunction with the exposure operation Da on the first operation member 38. The first operation member 38 is operably attached to the handle 32. Here, the first operation member 38 is described by taking a grip as an example, but it may be configured by a slide knob, a button, or the like. In addition, although an example in which the exposure operation Da is performed by moving the first operation member 38 toward the proximal end side in the axial direction is described, the specific example is not particularly limited, and a push operation, a rotation operation, or the like may be used. The first traction member 40 is configured by a rod, a wire, or the like. The tip of the first traction member 40 is connected to a part of the cover 34, and the base end of the first traction member 40 is connected to the first operation member 38.

[0020] Refer to FIGS. 7(A) to 7(C). As shown in FIGS. 7(A) and 7(B), by the exposure operation Da on the first operation member 38, a part of the cover 34 (here, the inner part 34b of the cover 34 in FIG. 6) is pulled toward the proximal end side by the first traction member 40 interlocked with the first operation member 38. As a result, with the movement of the axial distal end side of the outer peripheral portion 34a of the cover 34, the outer peripheral portion 34a of the cover 34 is drawn into the shaft 30 from the tip opening 30b of the shaft 30. As a result, the outer peripheral portion 34a of the cover 34 is axially pulled, so that the covered portion of the stent body 14 by the outer peripheral portion 34a of the cover 34 is gradually exposed, and the stent body 14 at the exposed portion expands by its self-expansion force. As shown in FIG. 7(C), when the entire covered portion of the stent body 14 covered by the cover 34 is exposed and the cover 34 no longer exists at a position overlapping the radially outer side of the stent body 14, the exposure operation of the stent body 14 by the tension mechanism 36 is completed.

[0021] Refer to FIGS. 5 and 8(A). The delivery catheter 16 includes an expansion restraint mechanism 50 that can restrain the expansion of a partial axial range of the stent body 14 and can release the restraint. The expansion restraint mechanism 50 includes a plurality of restraint wires 52 on which the stent wires 14c constituting the stent body 14 are hooked, and a second operation member 54 that receives a release operation Db by an operator for releasing the restraint of the stent body 14 by the plurality of restraint wires 52. In addition, the expansion restraint mechanism 50 includes a wire fixing member 56 to which the plurality of restraint wires 52 are fixed and that pulls each restraint wire 52 toward the proximal end side in conjunction with the release operation Db on the second operation member 54, and a displacement restricting member 58 that restricts the displacement of each of the plurality of restraint wires 52 toward the radially outer side.

[0022] The second operation member 54 is operably attached to the handle 32. The second operation member 54 may be constituted by a grip, a slide knob, a button, or the like. Here, as an operation mode of the second operation member 54, an example in which it can be moved axially will be described, but the specific example is not particularly limited, and a push operation, a rotation operation, or the like may also be used. The release operation Db on the second operation member 54 is performed by moving the second operation member 54 toward the proximal end side in the axial direction.

[0023] The wire fixing member 56 of the present embodiment also serves as the second operating member 54. The wire fixing member 56 only needs to be able to pull each restraint wire 52 toward the proximal end in conjunction with the release operation Db for the second operating member 54, and the specific configuration therefor is not particularly limited. For example, the second operating member 54 and the wire fixing member 56 are connected by a second pulling member such as a rod or a wire, and the wire fixing member 56 is pulled toward the proximal end by the second pulling member in conjunction with the release operation Db for the second operating member 54, thereby pulling each restraint wire 52 toward the proximal end.

[0024] The displacement restricting member 58 includes a distal end side displacement restricting portion 58a provided on the distal end side of the hooking portion 60 of the stent wire 14c with respect to the restraint wire 52, and a proximal end side displacement restricting portion 58b provided on the proximal end side of the hooking portion 60. The distal end side displacement restricting portion 58a is individually provided corresponding to each of the plurality of restraint wires 52. The proximal end side displacement restricting portion 58b is also individually provided corresponding to each of the plurality of restraint wires 52. In the present embodiment, each of the distal end side displacement restricting portion 58a and the proximal end side displacement restricting portion 58b is constituted by a hole extending in the axial direction of the displacement restricting member 58. The restraint wire 52 is inserted through the holes constituting the displacement restricting portions 58a and 58b. Each of the displacement restricting portions 58a and 58b can restrict the displacement of the restraint wire 52 outward in the radial direction by contacting the restraint wire 52 from the outside in the radial direction. In addition to this, each of the displacement restricting portions 58a and 58b of the present embodiment can also restrict the displacement of the restraint wire 52 inward in the radial direction by contacting the restraint wire 52 from the inside in the radial direction. The displacement restricting member 58 includes a recess 58c provided at a position corresponding to the hooking portion 60 of the stent wire 14c with respect to the restraint wire 52. The hooking portion 60 of the stent wire 14c is disposed within the recess 58c of the displacement restricting member 58.

[0025] Refer to FIGS. 5, 8(A), and 9. Each of the plurality of restraining wire members 52 extends in the axial direction. The restraining wire member 52 is a wire member made of, for example, metal, resin, or the like. The stent wire member 14c is hooked from the radially inner side of the restraining wire member 52. In this embodiment, the stent wire member 14c here refers to the core wire 20a of the stent 20 itself, but in addition to this, it may also be a wire member provided separately from the stent 20 on the stent body 14. FIG. 9 shows an example where there are a total of eight restraining wire members 52, but in FIG. 8(A) and the like, only two of the restraining wire members 52 are illustrated. The stent wire member 14c is hooked from the radially inner side at a plurality of circumferential positions spaced apart in the circumferential direction on each of the plurality of restraining wire members 52. By hooking the stent wire member 14c from the radially inner side to the plurality of restraining wire members 52, the outward expansion in the radial direction within a partial axial range of the stent body 14 is restricted. The plurality of restraining wire members 52 of the present embodiment restrict the expansion of the exposed portion 14a of the stent body 14 that is exposed from the cover 34 at the base end portion 14d of the stent body 14.

[0026] FIG. 4 also shows the hooking position of the stent wire member 14c with respect to the restraining wire member 52. FIG. 4 is a view of the stent 20 seen from the radially outer side, and the back side of the paper surface of FIG. 4 is the radially inner side. In the present embodiment, the bent portion 20c of the core wire 20a constituting the stent wire member 14c is hooked on the restraining wire member 52. Thereby, it becomes easier to hook the core wire 20a than to hook the intersection portions of the plurality of core wires 20a.

[0027] The above delivery catheter 16 separably supports the indwelling device 12. To achieve this, the delivery catheter 16 supports the stent body 14 maintained in a contracted state by the cover 34 with the shaft 30. Further, the delivery catheter 16 can separate the indwelling device 12 by releasing the restraint of the stent body 14 by the expansion restraint mechanism 50 along with the exposure operation of the stent body 14 by the tension mechanism 36. In addition to this, the delivery catheter 16 may detachably attach a part of the indwelling device 12 to a part of the delivery catheter 16 using a string or the like. In this case, in addition to the exposure operation of the stent body 14 by the tension mechanism 36 and the release of the restraint by the expansion restraint mechanism 50, the indwelling device 12 can be separated by cutting the string or the like.

[0028] The operation of the above expansion restraint mechanism 50 will be described. Referring to FIGS. 5 and 8(A). The above restraint wire 52 can be positioned at the hooking release position Pb where the hooking is released from the hooking position Pa where the portion receiving the stent wire 14c moves to the proximal end side in the axial direction. When the plurality of restraint wires 52 are at the hooking position Pa, the stent wire 14c is hooked on each of the plurality of restraint wires 52, and the expansion of the stent body 14 in a partial axial range is restrained.

[0029] By the release operation Db on the second operation member 54, the plurality of restraint wires 52 are pulled toward the proximal end side by the wire fixing member 56 interlocked with the second operation member 54. As a result, as shown in FIG. 8(B), the plurality of restraint wires 52 move from the hooking position Pa to the hooking release position Pb. As a result, the hooking of the stent wire 14c on the plurality of restraint wires 52 is collectively released, and the restraint of the stent body 14 by the plurality of restraint wires 52 is released. Along with this, the stent body 14 expands at the location restrained by the plurality of restraint wires 52, and the stent body 14 is attached to the inner cavity surface of the living organ at that location. Thus, the second operation member 54 of the present embodiment can collectively release the hooking of the stent body 14 on each of the plurality of restraint wires 52 by the release operation Db by the operator.

[0030] The expansion restraint mechanism 50 can release the restraint of the stent body 14 by the plurality of restraint wires 52 by moving the constituent members of the expansion restraint mechanism 50 to the proximal side inside the retainer 12 at a position on the proximal side of the hooking portion 60 of the stent wire 14c with respect to the restraint wire 52. Here, the constituent members of the expansion restraint mechanism 50 refer to the plurality of restraint wires 52 in the present embodiment. In addition to this, this constituent member may also be the above-mentioned traction member that connects the second operation member 54 and the wire fixing member 56, or the wire fixing member 56 or the like. The constituent members of the expansion restraint mechanism 50 move inside the portion surrounded by the stent body 14 on the proximal side of the hooking portion 60 as the "inside of the retainer 12" here. When the retainer 12 includes the cylindrical body 24 as in the present embodiment, the constituent members of the expansion restraint mechanism 50 also move inside the cylindrical body 24. When releasing the restraint of the stent body 14, this constituent member will not move to the proximal side while contacting the retainer 12 from the outer peripheral side on the proximal side of the hooking portion 60.

[0031] An example of the operation of the above delivery device 10 will be described. Here, as described above, the operation of the delivery device 10 using the OSG method will be described. In this OSG method, after opening the chest of the living body, a part of the thoracic aorta 18 is incised. Thereafter, using the delivery device 10, the indwelling tool 12 is delivered from the incision of the thoracic aorta 18 to the target site of the thoracic aorta 18. At this time, the indwelling tool 12 is delivered while gripping the handle 32 of the delivery catheter 16. Thereafter, by the release operation Db on the second operating member 54 of the expansion restraint mechanism 50, the restraint of the stent body 14 by the expansion restraint mechanism 50 is released. As a result, by the self-expansion force of the stent body 14, the portion where the expansion of the stent body 14 was restrained by the expansion restraint mechanism 50 is expanded, and that portion is attached to the target site of the thoracic aorta 18. Before and after this, an exposure operation Da on the first operating member 38 of the tension mechanism 36 is performed to perform an exposure operation for exposing the stent body 14. As a result, the covered portion of the stent body 14 covered by the cover 34 is exposed, and the exposed portion is expanded by the self-expansion force to be attached to the target site of the thoracic aorta 18. When the expansion of the stent body 14 is completed, the delivery catheter 16 of the delivery device 10 is pulled out from the indwelling tool 12 to the proximal end side and removed from the body. Thereafter, other necessary post-treatments are performed to complete the operation. The post-treatment here includes, for example, the operation of anastomosing the cuff 26 of the indwelling tool 12 and the blood vessel, and the operation of anastomosing the proximal end side portion of the graft 28 of the indwelling tool 12 and the blood vessel.

[0032] The effects of the above delivery device 10 will be described. The delivery device 10 includes a plurality of restraint wires 52 that restrain the expansion of the stent body 14 separately from the cover 34. Therefore, the expansion force acting on the cover 34 can be dispersed by each restraint wire 52. For this reason, the displacement of the cover 34 due to the expansion force of the stent body 14 can be suppressed, and the situation where a part of the stent body 14 is unintentionally exposed and then expanded due to the displacement can be suppressed. As a result, when the indwelling tool 12 is delivered into the body, the situation where an unintentionally expanded portion of the stent body 14 becomes an obstacle can be avoided.

[0033] Suppose a case where the introducer 12 is pushed into the body while a part of the stent body 14 remains unconstrained in its expanded state. In this case, the resistance to pushing increases because the expanded portion of the stent body 14 hits the inner cavity surface of the living organ. In this regard, according to the present embodiment, since unintentional expansion of the stent body 14 can be restrained, the pushing resistance when the introducer 12 is pushed into the body can be reduced. Further, it is possible to prevent the stent 20 from deforming due to pushing with a part of the stent body 14 remaining in an expanded state.

[0034] The plurality of restraining wire members 52 can release the restraint of the stent body 14 by moving in the axial direction. Therefore, by moving the plurality of restraining wire members 52 in the axial direction, the catching of the stent wire member 14c with respect to the restraining wire member 52 can be surely released, and the caught portion 60 can be stably expanded. Further, when releasing the restraint of the stent body 14 by the plurality of restraining wire members 52, there is no need to arrange a separate member around the plurality of restraining wire members 52, so that an increase in the outer diameter around the restraining wire member 52 can be suppressed accordingly.

[0035] Particularly, consider a case where a cylindrical body 24 having an outer diameter larger than the maximum outer diameter R34 of the cover 34 is connected to the proximal side of the stent body 14. In this case, if the proximal end portion 14d of the stent body 14 expands unintentionally on the distal side of the cylindrical body 24, there is a problem that the outer diameter of the proximal end portion 14d tends to gradually increase toward the cylindrical body 24 side, and the pushing resistance tends to increase. The plurality of restraining wire members 52 of the present embodiment restrain the expansion of the proximal end portion 14d of the stent body 14 in this way. Therefore, it is advantageous in that the pushing resistance at such a problematic location can be reduced.

[0036] From this perspective, the location where the expansion of the stent body 14 is restricted by the plurality of restraining wire members 52 is preferably closer to the cylindrical body 24 at the proximal end portion 14d of the stent body 14 on the distal side of the cylindrical body 24. From this perspective, when the stent 20 using a braided stent is provided in the stent body 14, the plurality of restraining wire members 52 may restrict the expansion of the proximal end portion 14d of the stent body 14 in the portion constituting the second to the second unit pattern 20b from the most proximal unit pattern 20b. In the present embodiment, in the portion constituting the most proximal unit pattern 20b, the stent wires 14c are hooked on the plurality of restraining wire members 52 at a plurality of circumferential positions. In addition to this, in the portion constituting the second unit pattern 20b from the most proximal side, the stent wires 14c may be hooked on the plurality of restraining wire members 52 at a plurality of circumferential positions. Further, when the stent body 14 includes a plurality of axially separated stents 20 (such as Z stents), the plurality of restraining wire members 52 may restrict the expansion of the proximal end portion 14d of the stent body 14 in the most proximal stent 20.

[0037] Suppose a case where a winding member such as a ring member wound around the outer peripheral side of the stent body 14 is used as a restraining member for restraining the expansion of the stent body 14. In this case, the outer diameter increases by the amount of the winding member at the location where the expansion of the stent body 14 is to be restrained, and the pushing resistance still remains large. In this regard, according to the present embodiment, the plurality of restraining wire members 52 are used as the restraining member. Therefore, it is not necessary to wind the restraining member at the location where the expansion of the stent body 14 is to be restrained, and an increase in the outer diameter caused by the winding can be avoided. As a result, compared with the case of using a winding member as the restraining member, it is easier to reduce the outer diameter of the location where the expansion of the stent body 14 is to be restrained, and accordingly, the pushing resistance can be reduced.

[0038] When a winding member is used as the restraining member, it is necessary to release the restraint of the stent body 14 by the winding member by moving the constituent members (such as the winding member) of the expansion restraint mechanism 50 while contacting the indwelling device 12 from the outer peripheral side. For this reason, when releasing the restraint of the stent body 14 by the winding member, the constituent members of the expansion restraint mechanism 50 greatly interfere with the indwelling device 12.

[0039] In this regard, the expansion restraint mechanism 50 of the present embodiment can release the restraint of the stent body by moving the constituent members (here, the restraint wire 52) of the expansion restraint mechanism 50 inside the indwelling device 12 on the proximal side of the hooking portion 60. Therefore, when releasing the restraint of the stent body 14, the constituent members of the expansion restraint mechanism 50 do not greatly interfere with the indwelling device 12, and the release operation can be facilitated. In particular, when the delivery device 10 is used, the state of the indwelling device 12 is often in a situation where it is invisible. It is advantageous in that it can avoid a large interference with the indwelling device 12 in such an invisible situation.

[0040] The plurality of restraint wires 52 restrain the expansion of the exposed portion 14a of the stent body 14 exposed from the cover 34. Therefore, it is not necessary to cover the cover 34 at the hooking portion 60 of the stent wire 14c with respect to the restraint wire 52, and accordingly, an increase in the outer diameter around the hooking portion 60 can be suppressed.

[0041] When the stent wire 14c is hooked on the plurality of restraint wires 52 at a plurality of circumferential positions, an expansion force acting radially outward acts on the portion of the restraint wire 52 that receives the stent wire 14c, and each of the plurality of restraint wires 52 tends to be displaced radially outward. According to the present embodiment, a displacement restricting member 58 that restricts the displacement of each of the plurality of restraint wires 52 radially outward is provided. Therefore, the displacement of each of the plurality of restraint wires 52 radially outward due to the expansion force of the plurality of restraint wires 52 can be restricted, and the stent body 14 can be stably maintained in a slightly contracted state at the hooking portion 60 of the stent wire 14c.

[0042] The expansion restraint mechanism 50 can collectively release the engagement of the stent wire 14c with each of the plurality of restraint wires 52. Therefore, compared with the case of individually releasing the engagement of the stent wire 14c for each of the plurality of restraint wires 52, the operation for releasing the engagement of the stent wire 14c can be simplified.

[0043] (Second Embodiment) Refer to FIGS. 10(A) and 10(B). In the following embodiments, among the components described in the first embodiment, the components not described below may have the same content applied as in the first embodiment. Also, the delivery device 10 in the following embodiments can exhibit the same effects as those described in the first embodiment.

[0044] The expansion restraint mechanism 50 of the first embodiment has been described for the case where it does not interlock with the tension mechanism 36. The expansion restraint mechanism 50 of the present embodiment can release the restraint of the stent body 14 in conjunction with the tension mechanism 36.

[0045] The expansion restraint mechanism 50 includes a mounting member 70 that is fixed to the wire fixing member 56 and detachably attached to the receiving portion 38a of the first operation member 38, and a restricting member 72 that is fixed to the handle 32 and can restrict the movement of the wire fixing member 56 toward the axial base end side. In the present embodiment, the second operation member 54 of the expansion restraint mechanism 50 also serves as the first operation member 38. The release operation Db for the second operation member 54 also serves as the exposure operation Da for the first operation member 38. Also, in the present embodiment, the wire fixing member 56 of the expansion restraint mechanism 50 is provided separately from the second operation member 54 (the first operation member 38).

[0046] The mounting member 70 of the present embodiment is an elastic claw that is hooked on the receiving portion 38a of the first operating member 38, and can be separated from the first operating member 38 by releasing the hook on the receiving portion 38a with its own elastic deformation. In this case, the receiving portion 38a is constituted by a claw receiving portion provided on the first operating member 38. Specific examples of the mounting member 70 and the receiving portion 38a are not particularly limited, and may be a combination of magnets or the like. The mounting member 70 can be separated from the first operating member 38 when the exposure operation Da with respect to the first operating member 38 is continued while the movement of the wire fixing member 56 toward the proximal end side in the axial direction is restricted by the restricting member 72. The restricting member 72 can restrict the movement of the wire fixing member 56 toward the proximal end side in the axial direction by contacting the wire fixing member 56 or a member (for example, the mounting member 70) that can move integrally with the wire fixing member 56.

[0047] The operations of the above-described expansion restraint mechanism 50 and tension mechanism 36 will be described. When the exposure operation Da (release operation Db by the second operating member 54) by the first operating member 38 is started, the wire fixing member 56 moves toward the proximal end side in the axial direction together with the mounting member 70 attached to the first operating member 38. As a result, as shown in FIG. 10(B), the plurality of restraint wires 52 move from the hooked position Pa to the unhooked position Pb, so that the hooking of the stent wire 14c (not shown) on the plurality of restraint wires 52 is released, and the restraint of the stent body 14 by the expansion restraint mechanism 50 is released. The restricting member 72 is provided at a position where it does not restrict the movement of the wire fixing member 56 until the plurality of restraint wires 52 move to the unhooked position Pb. After that, when the exposure operation Da with respect to the first operating member 38 is continued, the movement of the wire fixing member 56 toward the proximal end side in the axial direction is restricted by the restricting member 72. In this state, when the exposure operation Da with respect to the first operating member 38 is continued, the mounting member 70 is separated from the first operating member 38. Thereafter, when the exposure operation Da by the first operating member 38 is continued, only the first operating member 38 moves toward the proximal end side in the axial direction while being separated from the wire fixing member 56, and an exposure operation for exposing the covered portion of the stent body 14 is started.

[0048] The above wire fixing member 56 is detachably attached to the first operating member 38 (second operating member 54) via the attachment member 70 in conjunction with the release operation Db for the second operating member 54. Further, after the restraint of the stent body 14 by the expansion restraint mechanism 50 is released, the wire fixing member 56 separates from the first operating member 38, and thereafter, even if the exposure operation Da by the first operating member 38 is continued, it becomes immovable in the axial proximal direction.

[0049] In this way, the expansion restraint mechanism 50 can release the restraint of the stent body 14 in conjunction with the tension mechanism 36. By one operation of the operator on the first operating member 38 (the exposure operation Da also serving as the release operation Db) that the second operating member 54 also serves as, the covered portion of the stent body 14 is exposed by the tension mechanism 36, and the restraint of the stent body 14 by the expansion restraint mechanism 50 can be released. As a result, compared with the case where the operations on the tension mechanism 36 and the expansion restraint mechanism 50 are made individual, the number of operations by the operator can be reduced.

[0050] In particular, the expansion restraint mechanism 50 of the present embodiment can release the restraint of the stent body 14 before starting the exposure operation to expose the covered portion of the stent body 14 covered by the cover 34. Here, "before starting the exposure operation" means before starting the exposure of the covered portion of the stent body 14 by the cover 34 after starting the exposure operation Da by the first operating member 38. Thereby, in conjunction with the tension mechanism 36, the restraint by the expansion restraint mechanism 50 can be released earlier. As a result, by early attaching the portion of the stent body 14 restrained by the expansion restraint mechanism 50 to the inner cavity surface of the living organ, the axial position of the indwelling device 12 with respect to the living organ can be positioned earlier.

[0051] In relation to such an effect, the expansion restraint mechanism 50 may be able to release the restraint on the stent body 14 immediately after starting the exposure operation of the stent body 14. Here, immediately after starting the exposure operation refers to the period from the start of the exposure of the covered portion of the stent body 14 by the cover 34 until the stent body 14 begins to be exposed by an axial length of 1 / 10 of the total axial length of the covered portion 14b (see FIG. 6) of the stent body 14 by the cover 34.

[0052] (Third Embodiment) Refer to FIGS. 11(A) to 11(D). FIGS. 11(A) to 11(D) are explanatory diagrams for explaining the operation of the delivery device 10 of the third embodiment. Different from the second embodiment, the expansion restraint mechanism 50 of the present embodiment can release the restraint on the stent body 14 in conjunction with the completion of the exposure operation of the stent body 14 by the tension mechanism 36. The expansion restraint mechanism 50 includes a stopper 80 fixed to the first traction member 40, a stopper receiver 82 capable of receiving the stopper 80 when the stopper 80 moves axially toward the proximal end side together with the first traction member 40, and a fixing member 84 fixed to the wire fixing member 56 and fixed to the stopper receiver 82. In the stopper receiver 82 of the present embodiment, the first traction member 40 is slidably inserted therethrough. The stopper receiver 82 can move axially toward the proximal end side together with the stopper 80 when the first traction member 40 moves axially toward the proximal end side while receiving the stopper 80. The second operation member 54 of the expansion restraint mechanism 50 of the present embodiment also serves as the first operation member 38, similar to the second embodiment. Also in the present embodiment, the wire fixing member 56 of the expansion restraint mechanism 50 is provided separately from the second operation member 54 (the first operation member 38), similar to the second embodiment.

[0053] The operations of the above-described expansion restraint mechanism 50 and the tension mechanism 36 will be described. As shown in FIG. 11(B), the exposure operation Da (release operation Db by the second operation member 54) by the first operation member 38 is started. As a result, as described above, a part of the cover 34 is pulled toward the proximal end side by the first traction member 40, so that the cover 34 is axially pulled and the covered portion of the stent body 14 by the cover 34 begins to be exposed. After this, as shown in FIG. 11(C), even after the entire covered portion of the stent body 14 covered by the cover 34 is exposed, when the exposure operation Da by the first operation member 38 is continued, the stopper 80 fixed to the first traction member 40 contacts the stopper receiver 82. When the exposure operation Da of the first operation member 38 (release operation Db of the second operation member 54) is continued in this state, the wire fixing member 56 together with the fixing member 84 moves toward the proximal end side in the axial direction by the stopper receiver 82. As a result, as shown in FIG. 11(D), the plurality of restraint wires 52 move from the hooking position Pa to the unhooking position Pb, so that the hooking of the stent wire 14c (not shown) to the plurality of restraint wires 52 is released, and the restraint of the stent body 14 by the expansion restraint mechanism 50 is released.

[0054] The above-described wire fixing member 56 will not move toward the proximal end side in the axial direction without being interlocked with the exposure operation Da with respect to the first operation member 38 until the exposure operation of the stent body 14 is completed. Further, the wire fixing member 56 will be able to move toward the proximal end side in the axial direction in conjunction with the exposure operation Da with respect to the first operation member 38 after the exposure operation of the stent body 14 is completed. Here, "completing the exposure operation" means that, as described above, the entire covered portion of the stent body 14 covered by the cover 34 is exposed and the cover 34 does not exist at a position overlapping the outside in the radial direction of the stent body 14. Similar to the second embodiment, the above-described expansion restraint mechanism 50 can also release the restraint of the stent body 14 in conjunction with the tension mechanism 36, so that the number of operations by the operator can be reduced.

[0055] In addition, after the exposure operation of the stent body 14 by the tension mechanism 36 is completed, the expansion restraint mechanism 50 of the present embodiment can release the restraint of the stent body 14 in conjunction with the tension mechanism 36. In order to achieve this, even after the exposure operation Da of the stent body 14 is completed by performing the exposure operation Da by the first operation member 38, by continuing the exposure operation Da (release operation Db), the restraint of the stent body 14 can be released.

[0056] Thereby, until the exposure operation of the stent body 14 is completed, by hooking the stent wire 14c on the restraint wire 52, axial displacement of the retainer 12 with respect to the delivery catheter 16 can be suppressed. Such displacement of the retainer 12 occurs when a frictional force is applied to the stent body 14 from the cover 34 during the exposure operation of the stent body 14. By suppressing such displacement of the retainer 12 during the exposure operation of the stent body 14, it is possible to improve the accuracy in arranging the retainer 12 at the target position. In addition, there is also an advantage that other members (such as threads) for connecting the stent body 14 and the delivery catheter 16 can be made unnecessary in order to prevent displacement of the retainer 12.

[0057] In relation to such an effect, the expansion restraint mechanism 50 may be able to release the restraint of the stent body 14 immediately before the exposure operation of the stent body 14 is completed. Immediately before the exposure operation of the stent body 14 here means the period from when the stent body 14 begins to be exposed by an axial length of 9 / 10 of the total axial length of the covered portion 14b (see FIG. 6) of the stent body 14 by the cover 34 until the exposure operation of the stent body 14 is completed.

[0058] The deformation modes of the above components will be described.

[0059] The retainer 12 does not necessarily include the cylindrical body 24. The outer diameter R24 of the tip of the cylindrical body 24 may be less than or equal to the maximum outer diameter R34 of the cover 34. Specific examples of the cylindrical body 24 are not particularly limited. The cylindrical body 24 may include, for example, only one of the graft 28 and the cuff 26, or may have other configurations.

[0060] The tension mechanism 36 was described as an example of pulling the cover 34 in the axial direction as the outer peripheral portion 34a of the cover 34 moves toward the axial distal end side. Alternatively, the tension mechanism 36 may pull the cover 34 in the axial direction as the outer peripheral portion 34a of the cover 34 moves toward the axial proximal end side. In this case, the cover 34 may have only the outer peripheral portion 34a without having a double structure.

[0061] The specific structure for realizing the expansion restraint mechanism 50 is not particularly limited. For example, in order to interlock the second operation member 54 and the wire fixing member 56, both of them may be connected via other members such as the second traction member described above. The constituent members of the expansion restraint mechanism 50 may be able to release the restraint of the stent body 14 by moving outside the retainer 12 on the proximal end side of the hooking portion 60 of the stent wire 14c with respect to the restraint wire 52.

[0062] Although an example in which the plurality of restraint wires 52 restrain the expansion of the proximal end portion 14d of the stent body 14 has been described, the location where the expansion is restrained is not particularly limited, and either the distal end portion or the intermediate portion of the stent body 14 may be restrained from expanding. Further, the plurality of restraint wires 52 may restrain the expansion of the covered portion 14b of the stent body 14 covered by the cover 34, in addition to the exposed portion 14a of the stent body 14 exposed from the cover 34. When releasing the restraint of the stent body 14, the moving direction in the axial direction at the location where the plurality of restraint wires 52 receive the stent wire 14c is not particularly limited, and it may be either the proximal end side or the distal end side.

[0063] In addition to the expansion restraint mechanism 50 being interlocked with the tension mechanism 36, the order relationship between the timing of the exposure operation by the tension mechanism 36 and the timing of releasing the restraint of the stent body 14 by the expansion restraint mechanism 50 is not particularly limited. For example, the restraint of the stent body 14 by the expansion restraint mechanism 50 may be released at an arbitrary timing during the exposure operation by the tension mechanism 36.

[0064] There is no particular limitation on a specific example for releasing the restraint on the stent body 14 by the expansion restraint mechanism 50 in conjunction with the tension mechanism 36. For example, as in the second embodiment, when attaching the attachment member 70 fixed to the wire fixing member 56 to the first operation member 38, the attachment member 70 may be attached to the first operation member 38 in a non-detachable manner. Also, as in the third embodiment, when moving the stopper receiver 82 axially toward the proximal end side by the stopper 80 fixed to the first traction member 40, the wire fixing member 56 may also serve as the stopper receiver 82. Further, in order to release the restraint on the stent body 14 before or immediately after starting the exposure operation by the tension mechanism 36 as in the second embodiment, the stopper 80 fixed to the first traction member 40 and the stopper receiver 82 for receiving the stopper 80 may be used as in the third embodiment. Also, there is no particular limitation on a specific example for detachably attaching the attachment member 70 of the expansion restraint mechanism 50 to the first operation member 38. In order to achieve this, an example using the restricting member 72 was described in the second embodiment, but this is not essential.

[0065] The expansion restraint mechanism 50 may not include the displacement restricting member 58. The displacement restricting member 58 only needs to be able to restrict the displacement of the plurality of restraint wires 52 outward in the radial direction, and it is not essential to restrict the displacement inward in the radial direction, and the specific structure therefor is not particularly limited. For example, the displacement restricting member 58 may include only one of the distal end side displacement restricting portion 58a and the proximal end side displacement restricting portion 58b. Also, each displacement restricting portion 58a, 58b of the displacement restricting member 58 may be configured in a ring shape, cylindrical shape, etc. that can hook the restraint wire 52 instead of a hole. The expansion restraint mechanism 50 may include an individual second operation member 54 for individually releasing the hooking of the stent body 14 for each individual restraint wire 52.

[0066] The above embodiments and modified forms are illustrative. The technical ideas abstracted from these should not be construed as being limited to the contents of the embodiments and modified forms. Many design changes such as component changes, additions, deletions, etc. are possible for the contents of the embodiments and modified forms. In the foregoing embodiments, with regard to the contents for which such design changes are possible, the notation "embodiment" is attached and emphasized. However, design changes are also permitted for the contents without such notation. The hatching attached to the cross-section of the drawing does not limit the material of the object to which the hatching is attached. The structures and numerical values mentioned in the embodiments and modified forms naturally include those that can be regarded as the same considering manufacturing errors.

Explanation of Reference Numerals

[0067] 10… Delivery device, 12… Retainer, 12a… Proximal end side cylindrical portion, 14… Stent body, 14a… Exposed portion, 14c… Stent wire, 16… Delivery catheter, 20… Stent, 24… Cylindrical body, 34… Cover, 36… Tension mechanism, 50… Expansion restraint mechanism, 52… Restraint wire, 58… Displacement restricting member.

Claims

1. An indwelling device having a self-expandable stent body, and a delivery catheter that separably supports the indwelling device, wherein the delivery catheter, includes a cover that covers at least a partial axial range of the stent body, and an expansion restraint mechanism having a plurality of restraint wires that restrain the expansion of the stent body by hooking the stent wires that constitute the stent body, wherein the plurality of restraint wires can release the restraint of the stent body by moving axially, and the expansion restraint mechanism is a delivery device capable of releasing the restraint of the stent body by moving a component of the expansion restraint mechanism inside the indwelling device on the proximal side of the hooking portion of the stent wire with respect to the restraint wire.

2. An indwelling device having a self-expandable stent body, and a delivery catheter that separably supports the indwelling device, wherein the delivery catheter, includes a cover that covers at least a partial axial range of the stent body, and an expansion restraint mechanism having a plurality of restraint wires that restrain the expansion of the stent body by hooking the stent wires that constitute the stent body, wherein the plurality of restraint wires can release the restraint of the stent body by moving axially, and the expansion restraint mechanism is a delivery device including a displacement restricting member that restricts the displacement of each of the plurality of restraint wires radially outward.

3. An indwelling device having a self-expandable stent body, and a delivery catheter that separably supports the indwelling device, wherein the delivery catheter, includes a cover that covers at least a partial axial range of the stent body, An expansion restraint mechanism having a plurality of restraint wires that restrain the expansion of the stent body by hooking the stent wires that make up the stent body. The plurality of restraint wires can release the restraint of the stent body by moving in the axial direction. The delivery catheter includes a tension mechanism that pulls the cover in the axial direction. The expansion restraint mechanism is a delivery device that can release the restraint of the stent body in conjunction with the tension mechanism.

4. The tension mechanism performs an exposure operation of exposing the covered portion of the stent body by the cover by pulling the cover in the axial direction. The expansion restraint mechanism releases the restraint of the stent body before or immediately after the start of the exposure operation by the tension mechanism. The delivery device according to claim 3.

5. The tension mechanism performs an exposure operation of exposing the covered portion of the stent body by the cover by pulling the cover in the axial direction. The expansion restraint mechanism releases the restraint of the stent body immediately before or after the completion of the exposure operation by the tension mechanism. The delivery device according to claim 3.

6. An indwelling device having a self-expandable stent body. A delivery catheter that separably supports the indwelling device. The delivery catheter A cover that covers at least a partial axial range of the stent body. An expansion restraint mechanism having a plurality of restraint wires that restrain the expansion of the stent body by hooking the stent wires that make up the stent body. The plurality of restraint wires can release the restraint of the stent body by moving in the axial direction. The indwelling device includes a cylindrical body that is disposed on the proximal end side with respect to the stent body and is connected to the stent body. The outer diameter of the tip of the cylindrical body is larger than the maximum outer diameter of the cover. The plurality of restraining wire members is a delivery device that restrains the expansion of the proximal end portion of the stent body.

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