Delivery sheath

Abstract

The delivery sheath of the present application comprises an outer sheath, an inner sheath, at least one first connecting frame, at least one second connecting frame and a control member. The delivery sheath of the present application can ensure the smooth release of the stent and improve the success rate of the operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of interventional medical instruments, and particularly relates to a delivery sheath. BACKGROUND

[0002] With the continuous development of medical technology, a stent is implanted into the body by using minimally invasive surgery, and a treatment surgery for an aortic aneurysm and a dissection aneurysm is used, which is widely applied due to small trauma and fast recovery. The treatment mode is to compress the stent into a delivery device, guide into the human body along a pre-implanted guide wire track, release the stent after reaching the lesion position, isolate the lesion, and reconstruct the blood flow channel. After the loss of blood supply, the residual blood in the aneurysm cavity gradually thromboses and myelizes into vascular tissue, the aneurysm wall in the expanded state shrinks due to pressure, and gradually recovers to the original state, so as to achieve the purpose of treating the aneurysm and the dissection.

[0003] The stent system for the thoracic aortic aneurysm is composed of a metal skeleton and a covering film, the metal skeleton generally adopts a super-elastic memory alloy material, and after being pre-assembled in the sheath, a radial outward expansion force is generated, which requires the sheath to have sufficient support to resist the outward expansion force generated by the stent. If the support of the sheath is not enough, a protrusion caused by the outward expansion of the metal skeleton will be generated on the outer surface of the sheath, and such protrusion will generate great resistance when the sheath enters the blood vessel and subsequently advances in the blood vessel, and even damage the blood vessel. If the support of the sheath is enough, no protrusion will be caused after the stent is assembled, but this will cause a new problem in the treatment of the thoracic aortic aneurysm. The thoracic aortic aneurysm is located near the aortic arch, and the sheath needs to completely cross the arch or partially cross the arch. The bending of such sheath will be very difficult, and cannot well conform to the bending angle of the arch, resulting in damage to the blood vessel or failure to cross the arch.

[0004] In the prior art, two layers of sheaths are arranged to solve the above problem. The inner and outer sheaths are independent of each other, the outer sheath has good support, the inner sheath is relatively soft and has slightly weak support, and can meet the requirement of crossing the arch, but the existing inner sheath is directly retracted after release, the surface of the inner sheath caused by the outward expansion force of the stent is uneven, the inner sheath is easy to be stuck with the stent during release, and great release resistance or even release failure will be caused. SUMMARY

[0005] The purpose of the present application is to at least solve the problem that the inner sheath is easy to be stuck with the stent during the release of the stent. The purpose is achieved in the following way:

[0006] The present application provides a delivery sheath, which comprises:

[0007] an outer sheath;

[0008] The inner sheath is arranged inside the outer sheath, and comprises a main body and a folded part formed by folding the distal end of the main body towards the proximal end, and the inner sheath comprises a deployed state and a wrapped state; in the deployed state, at least one first connecting hole and at least one second connecting hole are arranged on the two sides of the main body respectively; in the wrapped state, the first connecting hole and the second connecting hole are close to each other, and the opening structure of the inner sheath is formed between the two sides of the main body, and at least one third connecting hole is arranged on the folded part;

[0009] The first connecting piece is arranged to close the opening structure, one end of the first connecting piece passes through and is fixed to the first connecting hole, and the other end of the first connecting piece passes through the second connecting hole and is formed with a fourth connecting hole;

[0010] The control piece passes through the fourth connecting hole, and the proximal end of the control piece extends to the proximal end of the delivery sheath;

[0011] The second connecting piece is arranged to pass through and connect the third connecting hole, and the proximal end of the second connecting piece is connected with the control piece to form a connecting point.

[0012] According to the delivery sheath, the delivery sheath is arranged in two layers of inner and outer layers, and the outer sheath and the inner sheath are arranged independently of each other, the stent is wrapped inside the inner sheath, one end of the first connecting piece is connected with the first connecting hole of the main body of the inner sheath in the wrapped state, the other end of the first connecting piece passes through the second connecting hole of the main body and is formed with a fourth connecting hole, the distal end of the control piece passes through the fourth connecting hole, so as to close the opening structure of the inner sheath in the wrapped state, and the stent inside the inner sheath is fixed and wrapped, and then the stent is delivered. The outer sheath has good supportability, can well resist the radial expansion force of the stent outward, prevents the radial deformation of the delivery sheath during the delivery process, and the inner sheath wraps the stent, so as to ensure the smooth delivery process. When the stent needs to be released in the blood vessel, the control piece is pulled towards the proximal end, the distal end of the control piece is separated from the fourth connecting hole, so as to release the constraint effect on the inner sheath, and the control piece drives the folded part of the inner sheath to move towards the proximal end through the second connecting piece, so that the inner sheath is transitioned from the wrapped state to the deployed state, the axial coverage area of the inner sheath on the stent is gradually reduced, the separation of the inner sheath and the stent is finally realized, and the inner sheath is collected in the outer sheath, so that the jamming phenomenon between the inner sheath and the stent during the release of the stent is effectively avoided, the smooth release of the stent is ensured, and the success rate of the operation is improved.

[0013] In addition, the delivery sheath according to the application can further have the following additional technical features:

[0014] In some embodiments of the present application, the second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the relaxed state, the distal end of the control member is arranged beyond the distal end of the inner sheath, the distance between the distal end of the control member and the distal end of the inner sheath is L1, the distance between the distal end of the second connecting member in the straightened state and the connecting point of the control member is L2, and the distance between the distal end of the second connecting member in the relaxed state and the connecting point of the control member is L3, wherein L1

[0015] In some embodiments of the present application, the second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the relaxed state, the distal end of the control member is arranged beyond the distal end of the inner sheath, the distance between the distal end of the control member and the distal end of the inner sheath is L1, the distance between the distal end of the second connecting member in the straightened state and the connecting point of the control member is L2, and the distance between the distal end of the second connecting member in the relaxed state and the connecting point of the control member is L3, wherein L1

[0016] In some embodiments of the present application, the second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the relaxed state, the distal end of the control member is arranged beyond the distal end of the inner sheath, the distance between the distal end of the control member and the distal end of the inner sheath is L1, the distance between the distal end of the second connecting member in the straightened state and the connecting point of the control member is L2, and the distance between the distal end of the second connecting member in the relaxed state and the connecting point of the control member is L3, wherein L1

[0017] In some embodiments of the present application, the two sides of the folded portion in the unfolded state are respectively provided with at least one third connecting hole, and when in the wrapped state, the third connecting holes are located on the two sides of the opening structure and close to the opening structure.

[0018] In some embodiments of the present application, the folded portion in the wrapped state is provided with a plurality of third connecting holes arranged at intervals in the circumferential direction.

[0019] In some embodiments of the present application, the folded portion in the unfolded state is provided with a film, at least part of any two opposite sides of the film is arranged in close contact with the folded portion, and the other two sides of the film are arranged in open, and the third connecting hole is formed between the film and the folded portion.

[0020] In some embodiments of the present application, the folded portion in the unfolded state is provided with at least one third connecting hole close to the center position.

[0021] In some embodiments of the present invention, the delivery sheath further comprises at least one automatically foldable member arranged along the axial direction of the inner sheath, the automatically foldable member being located on the folding portion, and when the control member abuts against the folding portion, the automatically foldable member is in a stretched state, and the folding portion is unfolded; when the control member loses contact with the folding portion, the automatically foldable member is in a folded state, and the folding portion is folded.

[0022] In some embodiments of the present invention, the delivery sheath further comprises at least one support portion disposed along the axial direction of the inner sheath, wherein the support portion is disposed opposite to a crest or a trough of the stent to be delivered. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0024] Figure 1 Schematic diagram of a partial assembly structure of the delivery sheath tube 100 according to the first embodiment;

[0025] Figure 2 for Figure 1 Schematic diagram of the connection structure between the inner sheath tube and the first connecting member, the second connecting member and the control member;

[0026] Figure 3 for Figure 1 A schematic diagram of the structure of the inner sheath tube in a wrapped state with the turning portion turned over;

[0027] Figure 4 for Figure 1 A schematic diagram of the structure of the inner sheath tube in the expanded state with the flip portion flipped over;

[0028] Figure 5 for Figure 1 A schematic diagram of the structure of the inner sheath tube in the expanded state and the flip portion is not flipped;

[0029] Figure 6 for Figure 1 A schematic structural diagram of the first connecting member;

[0030] Figure 7 for Figure 1 A schematic structural diagram of the second connecting member;

[0031] Figure 8 for Figure 1 Schematic diagram of the structure of the control unit;

[0032] Figure 9for Figure 1 A schematic diagram of a portion of the structure of the delivery sheath tube in which the distal end of the middle control member is arranged beyond the distal end of the inner sheath tube and the second connecting member is in a relaxed state;

[0033] Figure 10 for Figure 9 A schematic diagram of the enlarged structure of the middle part A;

[0034] Figure 11 This is a schematic diagram of the connection structure between the second connecting member and the control member in another example of this embodiment;

[0035] Figure 12 for Figure 9 A schematic diagram of a portion of the structure of the delivery sheath tube with the second connecting member in a stretched state;

[0036] Figure 13 for Figure 1 A schematic diagram of a portion of the structure of the delivery sheath tube in which the distal end of the middle control member does not extend beyond the distal end of the inner sheath tube and the second connecting member is in a relaxed state;

[0037] Figure 14 for Figure 13 A schematic diagram of a portion of the structure of the delivery sheath tube with the second connecting member in a stretched state;

[0038] Figure 15 for Figure 1 Schematic diagram of the relative position of the delivery sheath and the location of the intravascular lesion;

[0039] Figure 16 for Figure 15 Schematic diagram of the relative position structure of the inner sheath and the intravascular lesion after the middle and outer sheaths are withdrawn;

[0040] Figure 17 for Figure 16 Schematic diagram of the relative position structure of the stent and the intravascular lesion after the inner sheath is withdrawn;

[0041] Figure 18 for Figure 17 Schematic diagram of the relative position structure of the stent and the intravascular lesion after the delivery sheath is completely withdrawn from the blood vessel;

[0042] Figure 19 Schematic diagram of the structure of the inner sheath tube of the second embodiment;

[0043] Figure 20 To include Figure 19 Schematic diagram of the distal portion of the delivery sheath of the inner sheath;

[0044] Figure 21 Schematic diagram of the structure of the inner sheath tube of embodiment three;

[0045] Figure 22Structure diagram of the inner sheath in the embodiment four;

[0046] Figure 23 Structure diagram of the inner sheath in the embodiment five in the unfolded state and the folded part not being turned over;

[0047] Figure 24 Structure diagram of the inner sheath in the embodiment five in the unfolded state and the folded part being turned over; Figure 23

[0048] Figure 25 Structure diagram of the automatic folding member in the embodiment five; Figure 23

[0049] Figure 26 Structure diagram of the inner sheath in the embodiment six in the folded state and the folded part being turned over;

[0050] Figure 27 Structure diagram of the relative position between the inner sheath and the stent in the embodiment six in the straight state; Figure 26

[0051] Figure 28 Structure diagram of the relative position between the inner sheath and the stent in the embodiment six in the curved state. Figure 26 DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. While exemplary embodiments of the present application are illustrated, it should be understood that the present application can be embodied in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0053] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order

[0054] ​​​​Although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first," "second," and the like used herein do not imply a sequence or an order by which things happen. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0055] Spatially relative terms, such as "inner," "outer," "inward," "outward," "lower," "bottom," "top," "upper," and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0056] In order to more clearly describe the structure of the present application, the terms "proximal end" and "distal end" are defined herein as terms commonly used in the field of interventional medicine. Specifically, "distal end" refers to the end that is far from the operator during the operation, "proximal end" refers to the end that is close to the operator during the operation, "axial direction" refers to the length direction, and "radial direction" refers to the direction perpendicular to the "axial direction".

[0057] Embodiment One

[0058] In combination Figure 1 And Figure 2 As shown in the figure, the delivery sheath 100 of the present embodiment includes an outer sheath 10, an inner sheath 20, a first connecting piece 30, a second connecting piece 40, a control piece 50, and a sheath core 300.

[0059] The delivery sheath 100 of the present embodiment is used to deliver a stent 200, which is compressed inside the delivery sheath 100. The sheath core 300 with a tapered head 301 is arranged inside the stent 200. A reserved passage for a guide wire is arranged inside the sheath core 300. The delivery sheath 100 is guided to move inside the blood vessel by the guide wire passing through the reserved passage.

[0060] The outer sheath tube 10 is a hollow tubular structure with both ends open, and the inner sheath tube 20 is arranged in the inner part of the outer sheath tube 10 and can move along the axial direction of the outer sheath tube 10.

[0061] In combination Figure 2 and Figure 3 , the inner sheath tube 20 includes a main body part 21 and a folded part 22 formed by folding the distal end of the main body part 21 towards the proximal end, the main body part 21 is used to wrap and compress the stent 200, thereby being used to deliver the stent 200, and the folded part 22 is used to fold the inner sheath tube 20 axially during the release of the stent 200, thereby avoiding the jamming phenomenon between the inner sheath tube 20 and the stent 200 during the release of the stent 200, and ensuring the smooth release of the stent 200.

[0062] Among them, the first connecting part 30 is used to connect the main body part 21 and the control part 50, so as to control the first connecting part 30 through the control part 50, so as to constrain the inner sheath tube 20 to be in a wrapped state, so as to wrap and compress the stent 200, at the same time, the second connecting part 40 is used to connect the folded part 22 and the control part 50, so as to pull the second connecting part 40 to move axially through the control part 50 to realize the folding of the folded part 22 in the axial direction. Among them, the inner sheath tube 20 adopts a material that is easy to fold, such as PTFE film, high molecular non-woven fabric, high molecular textile fabric, etc., and the thickness is ≤0.020mm, and the inner sheath tube 20 is too thick, which is easy to make the inner sheath tube 20 too hard and not easy to bend, resulting in poor over-arch performance. The outer sheath tube 10 can be the sheath tube structure frequently used in the prior art.

[0063] In combination Figures 3 to 5 , the inner sheath tube 20 in the embodiment has at least an unfolded state and a wrapped state, and at least one first connecting hole 211 and at least one second connecting hole 212 are respectively arranged on both sides of the main body part 21 in the unfolded state, in the wrapped state, the first connecting hole 211 and the second connecting hole 212 are close to each other, and the opening structure 201 of the inner sheath tube is formed between the two sides of the main body part. In this embodiment, the plurality of first connecting holes 211 and the plurality of second connecting holes 212 on the main body part 21 in the wrapped state are arranged one by one, and in other embodiments, the first connecting hole 211 and the second connecting hole 212 can be arranged on the two sides of the main body part 21 at will.

[0064] The folded part 22 is provided with at least one third connecting hole. In this embodiment, Figure 4 and Figure 5 , at least one third connecting hole 221 is arranged on both sides of the folded part 22 in the unfolded state, and Figure 3 , when in the wrapped state, the third connecting holes 221 on both sides are located on both sides of the opening structure 201 and close to the opening structure 201.

[0065] The first connecting member 30 can be connected to the inner sheath 20 in various ways. The second connecting member 40 can be connected to the third connecting hole 221 in various ways.

[0066] In the embodiment, the first connecting member 30 is in a ring structure and is made of a flexible material such as a polymer material. In other embodiments, the first connecting member 30 can be in a wire structure. Figure 6 In the embodiment, the second connecting member 40 is in a strip structure and is made of a flexible material such as a polymer material or an elastic metal material. In other embodiments, the second connecting member 40 can be in a ring structure. Figure 7 In the embodiment, the control member 50 includes a rod 51 and a fixing part 52 arranged on the rod 51. The fixing part 52 is arranged at a position close to the proximal end outside the length range of the inner sheath 20. In the embodiment, the fixing part 52 is a concave-convex member, which is beneficial to the connection and positioning of the second connecting member 40. The rod 51 is made of a polymer material or an elastic metal material with a small elongation rate. Figure 8

[0067] In combination with Figs. 3 and 4, the distal end of the second connecting member 40 is fixed to at least one third connecting hole 221, and the proximal end of the second connecting member 40 is connected to the control member 50, specifically to the fixing part 52. In the embodiment, the fixing part 52 is arranged at a position close to the proximal end outside the length range of the inner sheath 20. One end of any first connecting member 30 is fixed to the first connecting hole 211 of the main body part 21 in the wrapped state, and the other end of the first connecting member 30 passes through the second connecting hole 212 of the main body part 21 to form a fourth connecting hole 31. The distal end of the control member 50 passes through the fourth connecting hole 31, and the proximal end of the control member 50 extends to the proximal end of the delivery sheath. The first connecting member 30 is used to close the opening structure 201. Figure 9 Figure 10

[0068] ​​​Specifically, one end of the first connecting member 30 is knotted after passing through any first connecting hole 211, so that the one end of the first connecting member 30 is firmly fixed on any first connecting hole 211, and then the other end of the first connecting member 30 passes through the second connecting hole 212 and forms the fourth connecting hole 31. The other end of the first connecting member 30 can be freely threaded in the second connecting hole 212, and when the distal end of the control member 50 passes through the fourth connecting hole 31, the other end of the first connecting member 30 cannot freely pass out of the second connecting hole 212 due to the action of the control member 50, thereby limiting the wrapping state of the inner sheath 20. When the distal end of the control member 50 is disengaged from the fourth connecting hole 31, that is, the distal end of the control member 50 is closer to the proximal end position than the fourth connecting hole 31, the control member 50 releases the restraining action on the other end of the first connecting member 30, and also releases the limiting action on the wrapping state of the inner sheath 20. The inner sheath 20 can gradually unfold from the wrapping state to the unfolded state.

[0069] The distal end of the control member 50 can pass through the plurality of fourth connecting holes 31 in turn, so that the first connecting member 30 closes the opening structure 201, thereby fixing the wrapping state of the inner sheath 20. When the distal end of the control member 50 is sequentially disengaged from the fourth connecting holes 31 from the distal end of the inner sheath 20 towards the proximal end, the first connecting member 30 is sequentially loosened, the opening structure 201 is gradually opened, and the control member 50 gradually loses the restraining force on the inner sheath 20, thereby releasing the inner sheath 20. The inner sheath 20 is unfolded from the position of the opening structure 201 towards both sides, so that the inner sheath 20 is gradually released from the wrapping state to the unfolded state, thereby facilitating the folding of the inner sheath 20 in the axial direction, and preventing the inner sheath 20 from being stuck with the stent 200 during the release of the stent 200.

[0070] One end of the second connecting member 40 is connected to the fixed part 52, and the other end of the second connecting member 40 passes through one third connecting hole 221 and then passes through the fixed part 52, and then passes through the third connecting hole 221 on the other side of the folding part 22 and is connected to the fixed part 52, thereby realizing the connection of the folding part 22 and the control member 50 through the second connecting member 40. The second connecting member 40 is divided into left and right two-segment structures with the fixed part 52 as the center through the fixed part 52, so that the folding part 22 moves towards the proximal end at an angle different from the axial direction when the folding part 22 is folded, thereby preventing the inner sheath 20 from being stuck with the stent 200 during the release of the stent 200.

[0071] In other examples of the embodiment, two second connecting members 40 can be selected, one end of one of the second connecting members 40 is connected to the fixing portion 52, and the other end passes through the third connecting hole 221 on one side of the folding portion 22 and is connected to the fixing portion 52. The other end of the other second connecting member 40 is also connected to the fixing portion 52, and the other end of the second connecting member 40 passes through the third connecting hole 221 on the other side of the folding portion 22 and is connected to the fixing portion 52. The connection between the folding portion 22 and the control member 50 can also be achieved by the second connecting member 40. In other embodiments, the number of third connecting holes 221 can be one, one end of the second connecting member 40 passes through and is fixed in the third connecting hole 221, and the other end of the second connecting member 40 is connected to the fixing portion 52.

[0072] In the embodiment, the second connecting member 40 is connected to the fixing portion 52 in a direction towards the opening structure 201 of the main body portion 21, that is, the second connecting member 40 is generally in a U shape (at this time, the second connecting member 40 has not been pulled tight), and the opening structure of the main body portion 21 is located in the middle of the U shape. In other examples of the embodiment, as shown in FIG. 6, the second connecting member 40 is connected to the fixing portion 52 in a direction away from the opening structure of the main body portion 21, so that when the folding portion 22 is pulled to fold, the folding portion 22 is forced to the two sides of the opening structure, and it is easier to fold and thus easier to remove the inner sheath 20 from the support 200. Specifically, the portion of the second connecting member 40 that is hidden by the inner sheath 20 in the middle can be arranged in a cross shape, so as to achieve the above connection mode. Figure 11 Figure 11

[0073] It should be noted that if the opening structure 201 is always in a closed state, the inner sheath 20 is directly pulled to move towards the proximal end to achieve separation from the support 200. Since the support 200 is compressed in the inner sheath 20, there is a large friction force between the support 200 and the inner sheath 20, and the inner sheath 20 is difficult to separate from the support 200. If the opening structure 201 is opened at the same time, the restraint between the support 200 and the inner sheath 20 is reduced, and the folding portion 22 is pulled to move towards the proximal end, the inner sheath 20 can be easily separated from the support 200.

[0074] In the embodiment, the second connecting member 40 has a relaxed state and a straightened state. In order to smoothly fold the folding portion 22 and easily remove the inner sheath 20 from the surface of the support 200 so as to be received in the outer sheath, the following conditions need to be met:

[0075] In combination with Figure 9 and Figure 12 ​​As shown, when the initial state of the second connecting member 40 is the relaxed state, and the distal end of the control member 50 is beyond the distal end of the folding portion 22, the distance between the distal end of the control member 50 and the distal end of the inner sheath 20 is L1, the distance between the distal end of the second connecting member 40 in the straightened state and the fixed portion 52 is L2, and the distance between the distal end of the second connecting member 40 in the relaxed state and the fixed portion 52 is L3, wherein L1

[0076] When the running distance of the control member 50 towards the proximal end is greater than L1 and less than L1+5mm, the second connecting member 40 is switched from the relaxed state in Figure 9 to the straightened state in Figure 12 At this time, the distal end of the control member 50 is just below the distal end of the folding portion 22 as shown in Figure 12 , and the opening structure 201 of the main body portion 21 is started to be opened. When the control member 50 continues to run towards the proximal end, the folding portion 22 is pulled by the control member 50 to move towards the proximal end in the axial direction.

[0077] When the proximal end of the control member 50 is continuously pulled, the distal end of the control member 50 continues to run to the center point position of the first second connecting hole 212 at the distal end, thereby achieving the release of the first connecting member 30, and further achieving the movement of the folding portion 22 towards the proximal end, thereby driving the folding of the main body portion 21 of the inner sheath 20.

[0078] When the second connecting member 40 switches from a relaxed state to a stretched state, the folding portion 22 does not start to move. The running distance of the second connecting member 40 switching from a relaxed state to a stretched state (that is, the movement distance of the distal end of the control member 50) cannot be too large. If it is too large, the opening structure of the main body 21 is opened too long, and the stent 200 is easily freed from the restraint of the inner sheath tube 20. The inner sheath tube 20 is unfolded under the radial support force of the stent 200. At this time, the folding portion 22 does not move proximally and cannot drive the folding of the main body 21. Then, the main body 21 of the inner sheath tube 20 that has not had time to fold will be squeezed between the stent 200 and the blood vessel wall due to its long length. It will be more difficult to achieve the folding of the main body 21, which may easily lead to the stent 200 not being released at the correct target position or even the folding failure. When the first metal coil of stent 200 is fully released, it adheres to the vessel wall. To ensure easy folding of the inner sheath 20, this distance must not exceed L1 + 1 / 2 the height of the first metal coil. Since the metal coil height is typically designed to be 10-14mm, the maximum distance is set to no more than L1 + 5mm. Furthermore, to ensure secure locking of stent 200, the distance between the center point of the first second connection hole 212 and the starting end of stent 200 must be less than 1 / 2 the height of the first metal coil, i.e., less than 5mm. In this case, the first second connection hole 212 refers to the first second connection hole 212 from the distal end.

[0079] Combine Figure 13 and Figure 14 As shown, when the distal end of the control member 50 does not extend beyond the distal end of the inner sheath tube 20, the distance between the distal end of the control member 50 and the distal end of the inner sheath tube 20 is L4, the distance between the distal end of the second connector 40 and the fixing portion 52 when the second connector 40 is in a stretched state is L5, and the distance between the distal end of the second connector 40 and the fixing portion 52 when the second connector 40 is in a relaxed state is L6. When the initial state of the second connector 40 is in a relaxed state, 0<L5-L6<5mm-L4, wherein 0<L4<5mm, and the maximum is preferably <2mm-L4. The reason for setting this length is consistent with the reason when the distal end of the control member 50 extends beyond the distal end of the folding portion 22. In another embodiment, similarly, when the initial state of the second connector 40 is in a stretched state, 0<L4≤5mm, and the maximum is preferably ≤2mm.

[0080] It is understood that the distance traveled by the second connector 40 from the relaxed state to the stretched state, that is, the distance traveled by the distal end of the control member 50 during this process, is the distance to which the distal end of the control member 50 moves, and the distance between the distal end of the inner sheath 20 and the position to which the opening structure 201 is actually opened is necessarily open. The actual length of the opening structure 201 opened during this process needs to be explained in conjunction with the situation of the first connector 30. The details are as follows:

[0081] In the process of switching the second connecting member 40 from the relaxed state to the straightened state, the state of the first connecting member 30 has the following two cases:

[0082] The first case is that in the process, the distal end of the control member 50 has not reached the center point of the first second connecting hole 212, and the distal end of the control member 50 is closer to the distal end than the center point of the first second connecting hole 212, that is, all the first connecting members 30 have not been separated from the control member 50, and all the first connecting members 30 have not been loosened. In the first case, the center point of the first second connecting hole 212 and the distal end of the folded portion 22 have a certain distance. In fact, because the inner sheath 20 is wrapped on the stent 200 and compressed in the outer sheath 10, the control member 50 is abutted between the outer sheath 10 and the inner sheath 20. As long as the distal end of the control member 50 starts to be lower than the position of the distal end of the folded portion 22, the part of the inner sheath 20 that is not abutted by the control member 50 starts to be opened, that is, the opening structure 201 of the main body portion 21 starts to be opened.

[0083] The second case is that in the process, the distal end of the control member 50 has reached the center point of the first second connecting hole 212, and the first connecting member 30 has been separated from the control member 50. At this time, the distance between the position of the second first connecting member and the position of the first first connecting member is small. When the first connecting member 30 is separated from the control member 50, the opening structure of the main body portion 21 is not too long, so that the stent 200 is easily released from the inner sheath 20. At this time, the distance between the position of the second first connecting member (the center point of the second second connecting hole 212) and the starting end of the stent 200 is less than 1 / 2 of the height of the first metal coil of the stent 200. At this time, the second second connecting hole 212 refers to the second second connecting hole 212 starting from the distal end.

[0084] It can be understood that in the second case, in the process of switching the second connecting member 40 from the relaxed state to the straightened state, if a plurality of first connecting members 30 are separated from the control member 50, the distal end of the control member 50 has reached the center point of the nth second connecting hole 212, and at this time, the distance between the position of the (n+1)th first connecting member (the center point of the (n+1)th second connecting hole 212) and the starting end of the stent 200 is less than 1 / 2 of the height of the first metal coil of the stent 200.

[0085] In combination Figures 15 to 18 As shown, the distal end of the guide wire 400 is inserted through the reserved channel of the sheath core 300 and moved to the lesion site in the blood vessel 500, Figure 15The convex structure on both sides of the middle blood vessel 500 is the lesion site. The delivery sheath tube 100 is moved along the direction of the guide wire 400, so that the distal end of the sheath core 300 exceeds the lesion site. The sheath core 300 or the outer sheath tube 10 is provided with a mark point for displaying the position. The outer sheath tube 10 is withdrawn towards the proximal end, so that the inner sheath tube 20 is exposed in the blood vessel 500, and the position of the inner sheath tube 20 is arranged opposite to the lesion site in the blood vessel 500. The folding part 22 is pulled by the control member 50, and the inner sheath tube 20 covering the surface of the stent 200 is gradually removed and collected in the outer sheath tube 10, so that the stent 200 is exposed in the blood vessel 500 and arranged opposite to the lesion site in the blood vessel 500, and finally the guide wire 400, the sheath core 300 and the delivery sheath tube 100 are withdrawn from the body. After the stent 200 loses the constraint of the inner sheath tube 20, the stent 200 is positioned by making the outer surface of the stent 200 adhere to the inner wall of the blood vessel 500 through radial deformation, so as to shield the lesion site and form a new blood flow channel, thereby ensuring the normal blood flow delivery process of the blood vessel 500.

[0086] According to the delivery sheath tube 100 of the embodiment, the delivery sheath tube 100 is arranged in two layers of inner and outer layers, and the outer sheath tube 10 and the inner sheath tube 20 are arranged independently of each other. The stent 200 is wrapped inside the inner sheath tube 20. One end of the first connecting member 30 is inserted through and fixed to the first connecting hole 211 of the main body part 21 of the inner sheath tube 20 in the wrapped state. The other end of the first connecting member 30 is inserted through the second connecting hole 212 of the main body part 21 and forms the fourth connecting hole 31. The distal end of the control member 50 is inserted through the plurality of fourth connecting holes 31, so that the stent 200 inside the inner sheath tube 20 is wrapped and fixed by the inner sheath tube 20, thereby being used for delivering the stent 200. The outer sheath tube 10 has good supportability, can well resist the radial outward expansion force of the stent 200, and prevents the delivery sheath tube 100 from being radially deformed during the delivery process. The inner sheath tube 20 is relatively soft and has slightly weak supportability, can meet the over-arch requirement, and thereby ensures the smooth delivery process. When the stent 200 needs to be released in the blood vessel 500, the control member 50 is pulled towards the proximal end, the distal end of the control member 50 is separated from the fourth connecting hole 31, so as to release the constraint on the inner sheath tube 20. Meanwhile, the control member 50 drives the folding part 22 of the inner sheath tube 20 to move towards the proximal end through the second connecting member 40, drives the main body part 21 of the inner sheath tube 20 to fold towards the proximal end, makes the inner sheath tube 20 transition from the wrapped state to the unfolded state, gradually removes the axial coverage area of the inner sheath tube 20 on the stent 200, finally realizes the separation of the inner sheath tube 20 from the stent 200, and collects the inner sheath tube 20 in the outer sheath tube 10, thereby effectively avoiding the jamming phenomenon between the inner sheath tube 20 and the stent 200 during the release process of the stent 200, ensuring the smooth release of the stent 200, and improving the success rate of the operation.

[0087] Embodiment two

[0088] The delivery sheath 100 of the present embodiment is basically the same as that of Embodiment One. Different from Embodiment One, referring to Figure 19 and Figure 20 , the folded portion 22 in the wrapped state of the present embodiment is provided with a plurality of third connecting holes 221 arranged in the circumferential direction. One end of the second connecting member 40 is connected to the control member 50, and the other end of the second connecting member 40 is connected to the control member 50 after sequentially passing through the plurality of third connecting holes 221, so that the stress on the circumferential direction of the folded portion 22 is more uniform, and the folded portion 22 moves more stably towards the proximal end.

[0089] Embodiment Three

[0090] The delivery sheath 100 of the present embodiment is basically the same as that of Embodiment One. Different from Embodiment One, referring to Figure 21 , the folded portion 22 in the unwrapped state of the present embodiment is provided with a film 60 arranged in the axial direction perpendicular to the folded portion 22, the two sides of the film 60 in the width direction are arranged in close contact with the folded portion 22, and the two sides of the film 60 in the length direction are arranged in open. Thus, the third connecting holes 221 are formed between the film 60 and the folded portion 22. One end of the second connecting member 40 is connected to the control member 50, and the other end of the second connecting member 40 is connected to the control member 50 after passing through the third connecting holes 221 formed between the film 60 and the folded portion 22. Thus, the stress on the circumferential direction of the folded portion 22 is more uniform, and the folded portion 22 moves more stably towards the proximal end.

[0091] In other embodiments, the film 60 can be arranged in any direction on the folded portion 22 in the unwrapped state, and the position of the close connection between the film 60 and the folded portion 22 can be located in at least part of the area of any two opposite sides. The close connection position can be point close connection or line close connection.

[0092] Embodiment Four

[0093] The delivery sheath of the present embodiment is basically the same as that of Embodiment One. Different from Embodiment One, referring to Figure 22 , the folded portion 22 in the unwrapped state of the present embodiment is provided with two third connecting holes 221 arranged in the axial direction perpendicular to the folded portion 22 and spaced apart. One end of the second connecting member 40 is connected to the control member 50, and the other end of the second connecting member 40 is connected to the control member 50 after passing through the two third connecting holes 221. By arranging the third connecting holes 221 away from the position of the opening structure formed when the inner sheath 20 is in the wrapped state, the transition contraction of the two sides of the inner sheath 20 towards the opening structure direction when the folded portion 22 is folded can be effectively avoided, and the inner sheath 20 can be effectively prevented from being stuck on the stent 200, resulting in the failure of the stent 200 to be stripped.

[0094] In other embodiments, the number of the third connecting hole 221 is at least one, and the multiple third connecting holes 221 can be arbitrarily set near the center position of the folding portion 22 in the expanded state, and are not necessarily spaced apart along the axial direction perpendicular to the folding portion 22.

[0095] Implementation Method Five

[0096] The delivery sheath 100 of this embodiment is basically the same as that of the embodiment 1. Figure 23 and Figure 24 The delivery sheath 100 of this embodiment further includes at least one automatically foldable member 70 disposed along the axial direction of the inner sheath 20. Specifically, in this embodiment, an automatically foldable member 70 is provided on either side of the folding portion 22. The automatically foldable member 70 connects the folding portion 22 and the main body 21. When the control member 50 contacts the folding portion 22 and abuts against the surface of the folding portion 22, the automatically foldable member 70 is stretched, thereby causing the folding portion 22 and the main body 21 to be arranged in sequence along the axial direction. This reduces the overall radial thickness of the inner sheath 20 during delivery, thereby facilitating delivery. When the control member 50 loses contact with the folding portion 22, the automatically foldable member 70 is folded, thereby facilitating axial folding of the inner sheath 20 and facilitating the release of the stent 200.

[0097] Among them, the automatic folding part 70 of this embodiment adopts superelastic material, such as nickel-titanium alloy material. When the distal end of the control part 50 contacts the folding part 22 and rests on the surface of the folding part 22, the automatic folding part 70 is in a stretched state. When the distal end of the control part 50 loses contact with the folding part 22, the automatic folding part 70 is in a folding state under the action of the radial force of the stent 200, and the inner sheath tube 20 is folded.

[0098] like Figure 25 As shown, in order to realize the automatic folding of the automatic folding member 70 without affecting the bow performance of the inner sheath tube 20, 0.01mm 2 <L9 *L10<4 mm 2 , where L9 represents the width of the automatic folding member 70, and L10 represents the thickness of the automatic folding member 70. If the product of L9 * L10 is too small, the automatic folding member 70 will not have sufficient elasticity to fold the inner sheath 20. If the product of L9 * L10 is too large, the automatic folding member 70 will be too rigid, making it too hard, making parts of the inner sheath 20 too rigid and deteriorating the bowing performance.

[0099] For example Figure 23As shown, to realize that the automatic foldable member 70 can fold the inner sheath 20, and does not affect the subsequent folding operation, 1 / 8L8 < L7 < 1 / 2L8. Wherein L7 refers to the distance between the automatic foldable member 70 and the edge of the inner sheath 20, L8 represents the width of the unfolded inner sheath 20. If L7 is too small, the edge of the inner sheath 20 can be better folded, but the middle part cannot be better folded, which affects the subsequent folding operation, if L7 is too large, the edge of the inner sheath 20 is folded worse, and even cannot be folded. In order to realize the better folding of the soft sheath, the automatic foldable member 70 is symmetrically distributed on the unfolded inner sheath 20.

[0100] The automatic foldable member 70 of the embodiment can also be used on the delivery sheath 100 in any one of the second embodiment, the third embodiment and the fourth embodiment.

[0101] Sixth embodiment

[0102] The delivery sheath 100 of the embodiment is basically the same as that in the second embodiment. Different from the second embodiment, referring to Figure 26 , Figure 27 and Figure 28 , the delivery sheath 100 of the embodiment further comprises at least one supporting part 80 arranged along the axial direction of the inner sheath 20, and the supporting part 80 is arranged corresponding to the peak or valley of the stent 200 to be delivered.

[0103] As shown in Figure 27 and Figure 28 , the inner sheath 20 is spaced apart in the axial direction and provided with a plurality of supporting parts 80, thereby improving the supporting property of the inner sheath 20, the supporting part 80 can be obtained by locally thickening, or other supporting structures can be added at the corresponding parts. After the stent 200 is assembled with the inner sheath 20, the supporting part 80 is located at the position where the peak or valley of the metal wave coil 210 intersects with the inner sheath 20. After the arch bending, the peak and valley of the stent 200 are bent in the area covered by the supporting part 80, which does not cause the inner sheath 20 to fold at this position and thus cause the stent 200 to be stuck, resulting in the failure of the stent 200 to be released, thereby ensuring the over-arch performance of the inner sheath 20. In the embodiment, to realize that the inner sheath 20 can be folded and has a certain supporting property, 0.02 mm < thickness of the supporting part 80 < 2 mm.

[0104] The supporting part of the embodiment can also be used on the delivery sheath 100 in any one of the first embodiment, the third embodiment, the fourth embodiment and the fifth embodiment.

[0105] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical scope disclosed by the present application, which can be easily thought by those skilled in the art, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A delivery sheath, comprising: The utility model relates to a delivery sheath, which comprises: an outer sheath; an inner sheath disposed inside the outer sheath, the inner sheath comprising a main body portion and a folded portion formed by folding a distal end of the main body portion towards a proximal end, the inner sheath comprising an unfolded state and a wrapped state, in the unfolded state, two sides of the main body portion are respectively provided with at least one first connecting hole and at least one second connecting hole, in the wrapped state, the first connecting hole and the second connecting hole are close to each other, and an opening structure of the inner sheath is formed between the two sides of the main body portion, the folded portion is provided with at least one third connecting hole; at least one first connecting member, the first connecting member closing the opening structure, one end of the first connecting member penetrating and being fixed to the first connecting hole, the other end of the first connecting member penetrating the second connecting hole and being formed with a fourth connecting hole; a control member penetrating the fourth connecting hole, a proximal end of the control member extending to a proximal end of the delivery sheath; at least one second connecting member, a distal end of the second connecting member penetrating and connecting the third connecting hole, and a proximal end of the second connecting member being connected to the control member to form a connecting point.

2. The delivery sheath of claim 1, wherein, The second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the relaxed state, a distal end of the control member is arranged beyond a distal end of the inner sheath, a distance between the distal end of the control member and the distal end of the inner sheath is L1, a farthest end of the second connecting member in the straightened state is away from the connecting point of the control member by a distance L2, and a farthest end of the second connecting member in the relaxed state is away from the connecting point of the control member by a distance L3, wherein L1 3. The delivery sheath of claim 1, wherein, The second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the straightened state, the distal end of the control member is not arranged beyond the distal end of the inner sheath, and a distance between the distal end of the control member and the distal end of the inner sheath is L4, wherein 0 4. The delivery sheath of claim 1, wherein, The second connecting member has a relaxed state and a straightened state, when the initial state of the second connecting member is the relaxed state, the distal end of the control member is not arranged beyond the distal end of the inner sheath, a distance between the distal end of the control member and the distal end of the inner sheath is L4, a farthest end of the second connecting member in the straightened state is away from the connecting point of the control member by a distance L5, and a farthest end of the second connecting member in the relaxed state is away from the connecting point of the control member by a distance L6, wherein 0 5. The delivery sheath of claim 1, wherein, The two sides of the folded portion in the unfolded state are respectively provided with at least one third connecting hole, and when in the wrapped state, the third connecting holes are located on the two sides of the opening structure and close to the opening structure.

6. The delivery sheath of claim 1, wherein, The folded portion in the wrapped state is provided with a plurality of third connecting holes arranged at intervals in a circumferential direction.

7. The delivery sheath of claim 1, wherein, The folding part in the unfolded state is provided with a film, at least part of any two opposite sides of the film is attached to the folding part, and the other two sides of the film are open. The third connecting hole is formed between the film and the folding part.

8. The delivery sheath of claim 1, wherein, The folding part in the unfolded state is provided with at least one third connecting hole near the center position.

9. The delivery sheath of claim 1, wherein, The delivery sheath further comprises at least one automatic folding part arranged along the axial direction of the inner sheath, the automatic folding part is located on the folding part, when the control part abuts against the folding part, the automatic folding part is in a straight state, and the folding part is unfolded; when the control part loses contact with the folding part, the automatic folding part is in a folded state, and the folding part is folded.

10. The delivery sheath of claim 1, wherein, The delivery sheath further comprises at least one supporting part arranged along the axial direction of the inner sheath, the supporting part is arranged opposite to the crest or trough of the stent to be delivered.

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