Interventional sheath group, interventional device and sheath tube

Abstract

The invention discloses an interventional sheath set, an interventional device and a sheathing canal, the interventional sheath set comprises an outer sheath and an inner sheath, and the outer sheath comprises an elastic sheathing canal extending in the axial direction of the outer sheath and a first passage defined by the elastic sheathing canal; a second passage extending in the axial direction of the inner sheath is arranged in the inner sheath, the outer sheath is arranged in the mode that when the inner sheath extends into the first passage, at least part of the elastic sheath tube expands and wraps the inner sheath extending into the first passage, and the second passage is communicated with the first passage; and when the inner sheath moves out of the first passage, the elastic sheath tube rebounds. The outer sheath comprises the elastic sheath tube, when the inner sheath intervenes into the first passage, the inner sheath enables the outer sheath to expand and wrap the surface of the inner sheath, the first passage is expanded, subsequent intervention of the interventional instrument is facilitated, after the interventional instrument reaches a designated position, the inner sheath is withdrawn, the elastic sheath tube rebounds and wraps the surface of the interventional instrument, and the interventional instrument is prevented from being damaged. The interventional diameter is reduced, and blood is prevented from flowing into the space between the elastic sheath tube and the interventional instrument to form thrombus.

Description

Technical Field

[0001] This application belongs to the field of medical device technology, and in particular relates to interventional sheath assemblies, interventional devices, and sheath tubes. Background Technology

[0002] In some scenarios, interventional vascular procedures require the initial placement of a catheter sheath to create access before interventional instruments are used within the sheath. However, commonly used interventional instruments often have inconsistent radial dimensions, for example, the tip diameter is larger than the tail diameter. To deliver these instruments, the diameter of the access within the catheter sheath needs to be larger than the maximum diameter of the instrument. This creates a gap between the access and the instrument, increasing the risk of thrombosis within the access. Furthermore, a large outer diameter of the catheter sheath can lead to lower limb arterial ischemia during the procedure and may exclude patients with treatment needs but smaller vessel diameters. Summary of the Invention

[0003] This application provides an interventional sheath assembly, an interventional device, and a sheath tube, which can reduce the interventional diameter.

[0004] This application provides an interventional sheath assembly, including an outer sheath and an inner sheath. The outer sheath includes an elastic sheath tube extending along its axial direction and a first passage formed by the elastic sheath tube. The inner sheath has a second passage extending along its axial direction. The outer sheath is configured such that when the inner sheath extends into the first passage, at least a portion of the elastic sheath tube expands and wraps around the inner sheath extending into the first passage, and the second passage is in communication with the first passage. When the inner sheath moves out of the first passage, the elastic sheath tube rebounds.

[0005] According to an embodiment of the first aspect of this application, the outer sheath includes a natural state and an expanded state that can be interchanged. When at least part of the inner sheath extends into the first passage, the outer sheath changes from the natural state to the expanded state, and at least part of the elastic sheath expands and wraps around the inner sheath extending into the first passage. When the inner sheath moves out of the first passage, the elastic sheath rebounds and causes the outer sheath to change from the expanded state to the natural state.

[0006] According to an embodiment of the first aspect of this application, the expanded state includes a partially expanded state. In the partially expanded state, the inner sheath passes through a portion of the first passage along the axial direction of the outer sheath, and the partial elastic sheath expands and wraps around the inner sheath extending into the first passage.

[0007] According to the first aspect of the present application, the expanded state includes a fully expanded state. In the fully expanded state, the inner sheath passes through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath tube is expanded and wraps around the inner sheath extending into the first passage.

[0008] According to an embodiment of the first aspect of this application, the radial dimension of the first passage in its natural state is smaller than the radial dimension of the outer surface of the inner sheath away from its central axis.

[0009] According to an embodiment of the first aspect of this application, the elastic sheath includes: an elastic layer; and a lubricating layer located on at least one side of the elastic layer, the friction coefficient of the lubricating layer being less than that of the elastic layer.

[0010] According to the embodiments of the first aspect of this application, the elastic layer is entirely composed of elastic material, or a portion of the elastic layer is composed of elastic material and another portion is composed of rigid material, or the elastic layer is formed by surrounding a mesh of elastic material.

[0011] According to an embodiment of the first aspect of this application, a lubricating layer is provided on both the side of the elastic layer facing the first passage and the side facing away from the first passage.

[0012] According to an embodiment of the first aspect of this application, the material of the elastic layer includes at least one of polydimethylsiloxane, polyurethane elastomer, and polyolefin elastomer, and the material of the lubricating layer includes at least one of polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

[0013] According to an embodiment of the first aspect of this application, it further includes: an outer sheath seat connected to the proximal end of the outer sheath, the outer sheath seat having a fourth passage extending along its axial direction and communicating with the first passage; and a fixed wing connected to the outer sheath seat, the fixed wing being located on the side of the outer sheath seat opposite to the fourth passage.

[0014] According to an embodiment of the first aspect of this application, it further includes: a balloon connected to an outer sheath seat and located within a fourth passage, the balloon enclosing a third passage communicating with a first passage; and an inflation tube communicating with the balloon, the inflation tube being used to inflate the balloon to reduce the radial dimension of the third passage or to release gas from the balloon to increase the radial dimension of the third passage.

[0015] According to an embodiment of the first aspect of this application, the circumferential dimension of the outer sheath is greater than or equal to 9F and less than or equal to 24F.

[0016] According to an embodiment of the first aspect of this application, the elasticity of the inner sheath is less than that of the outer sheath.

[0017] A second aspect of this application provides an interventional device, including an interventional instrument and an interventional sheath assembly as described above, wherein the interventional instrument and the interventional sheath assembly are detachably connected. The interventional device includes a first state, a second state, and a third state. In the first state, the outer sheath is in a natural state. In the second state, at least a portion of the inner sheath extends into a first passage, causing the outer sheath to change from a natural state to a partially expanded state or a fully expanded state. In the partially expanded state, the inner sheath passes through a portion of the first passage along the axial direction of the outer sheath, and a portion of the elastic sheath expands and encloses the inner sheath extending into the first passage. In the fully expanded state, the inner sheath passes through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath expands and encloses the inner sheath extending into the first passage. In the third state, the interventional instrument extends into the second passage from the proximal end of the inner sheath and extends out of the second passage from the distal end of the inner sheath.

[0018] According to an embodiment of the second aspect of this application, the interventional device further includes a fourth state in which the inner sheath and outer sheath are separately disposed, at least a portion of the interventional instrument is located within the first passage, and at least a portion of the outer sheath rebounds and wraps around the surface of the interventional instrument.

[0019] According to an embodiment of the second aspect of this application, it further includes: a guidewire detachably connected to the interventional sheath assembly, the guidewire being used to guide the interventional sheath assembly to a designated position; and a dilator detachably connected to the distal end of the inner sheath.

[0020] A third aspect of this application provides a sheath comprising an elastic sheath extending along its axial direction and a first passage formed by the elastic sheath, the sheath comprising a natural state and an expanded state that can be interchanged, wherein in the expanded state, at least a portion of the elastic sheath expands and increases the radial dimension of the first passage; and in the natural state, the elastic sheath springs back and decreases the radial dimension of the first passage.

[0021] According to the third aspect of this application, the expansion state includes a partially expanded state and a fully expanded state. In the partially expanded state, part of the elastic sheath expands and wraps around the inner sheath extending into the first passage. In the fully expanded state, the inner sheath passes through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath expands.

[0022] According to an embodiment of the third aspect of this application, the elastic sheath includes: an elastic layer; and a lubricating layer located on at least one side of the elastic layer, the friction coefficient of the lubricating layer being less than that of the elastic layer.

[0023] According to the embodiments of the third aspect of this application, the elastic layer is entirely composed of elastic material, or a portion of the elastic layer is composed of elastic material and another portion is composed of rigid material, or the elastic layer is formed by a mesh of elastic material surrounding it.

[0024] According to an embodiment of the third aspect of this application, a lubricating layer is provided on both the side of the elastic layer facing the first passage and the side facing away from the first passage.

[0025] According to an embodiment of the third aspect of this application, the material of the elastic layer includes at least one of polydimethylsiloxane, polyurethane elastomer, and polyolefin elastomer, and the material of the lubricating layer includes at least one of polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

[0026] The interventional sheath assembly of this application includes an outer sheath and an inner sheath. The outer sheath includes an elastic sheath extending along its axial direction and a first passage formed by the elastic sheath. The inner sheath has a second passage extending along its axial direction. The outer sheath is configured such that when the inner sheath is inserted into the first passage, at least part of the elastic sheath expands and wraps around the inner sheath inserted into the first passage, and the second passage communicates with the first passage. When the inner sheath is removed from the first passage, the elastic sheath rebounds. By including the elastic sheath in the outer sheath, this application allows the outer sheath to expand and wrap around the surface of the inner sheath when the inner sheath is inserted into the first passage, and the first passage is enlarged, facilitating the subsequent interventional device insertion. After the interventional device reaches the designated position, the inner sheath is withdrawn, and the elastic sheath rebounds and wraps around the surface of the interventional device. This reduces the interventional diameter and prevents blood from flowing into the space between the elastic sheath and the interventional device, thus preventing thrombus formation. Furthermore, the interventional sheath assembly of this application can reduce damage to blood vessels from long-term insertion and prevent lower limb ischemia caused by sheath occupancy during insertion. Finally, the interventional sheath assembly provided by this application has a simple structure and is easy to operate. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 (a) is a schematic diagram of the structure of the outer sheath in its natural state in some embodiments of the present application;

[0029] Figure 1 (b) is a schematic diagram of the structure of the inner sheath in some embodiments of the present application;

[0030] Figure 2 (a) shows an example Figure 1 (a) is a schematic diagram of the longitudinal cross-sectional structure of the outer sheath;

[0031] Figure 2 (b) shows an example Figure 1 (b) is a schematic diagram of the longitudinal cross-sectional structure of the inner sheath;

[0032] Figure 3 This is a schematic diagram of the interventional sheath assembly of some embodiments of this application in another scenario;

[0033] Figure 4 An example is shown. Figure 3 A schematic cross-sectional view of the interventional sheath assembly in section AA;

[0034] Figure 5 A schematic diagram of an interventional sheath assembly in another scenario is shown;

[0035] Figure 6 An example is shown. Figure 5 A schematic cross-sectional view of the interventional sheath assembly in section BB;

[0036] Figure 7 An example is shown. Figure 4 Enlarged cross-sectional view of the interventional sheath assembly in region C;

[0037] Figure 8 Another example is shown Figure 4 Enlarged cross-sectional view of the interventional sheath assembly in region C;

[0038] Figure 9 A longitudinal sectional view of an example of an outer sheath and fixed wing is shown.

[0039] Figure 10 A longitudinal sectional view of another example of the outer sheath and fixed wing is shown.

[0040] Figure 11 A schematic diagram of an example interventional device is shown.

[0041] Figure label:

[0042] 10. Interventional sheath assembly; 20. Interventional devices;

[0043] 100. Outer sheath; 110. Elastic sheath tube; 111. Elastic layer; 112. Lubricating layer; 120. First passage;

[0044] 200. Inner sheath; 210. Second pathway;

[0045] 300. Outer sheath seat; 310. Fourth passageway;

[0046] 400. Fixed-wing aircraft;

[0047] 500. Balloon; 510. Third access route;

[0048] 600. Inflation hose;

[0049] x, the first direction. Detailed Implementation

[0050] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0051] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0052] The interventional sheath assembly provided in the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that in the drawings, the direction extending along the line connecting the proximal and distal ends of the interventional sheath assembly, and pointing from the distal end to the proximal end, is the first direction, denoted as x. In the drawings, for ease of drawing, the dimensions are not necessarily proportional to the actual dimensions.

[0053] Combination Figure 1 (a) to Figure 6 As can be seen, in order to solve the technical problems involved in the background art, the applicant proposes an interventional sheath assembly 10, which includes an outer sheath 100 and an inner sheath 200. The outer sheath 100 includes an elastic sheath tube 110 extending along its axial direction (direction x in the figure) and a first passage 120 formed by the elastic sheath tube 110. The inner sheath 200 is provided with a second passage 210 extending along its axial direction. The outer sheath 100 is configured such that when the inner sheath 200 extends into the first passage 120, at least a portion of the elastic sheath tube 110 expands and wraps around the inner sheath 200 extending into the first passage 120, and the second passage 210 communicates with the first passage 120. When the inner sheath 200 moves out of the first passage 120, the elastic sheath tube 110 rebounds.

[0054] It should be noted that the axial direction of the outer sheath 100 can be understood as the direction in which the interventional device intervenes through the interventional sheath assembly 10, or as the direction of extension of the first passage in the outer sheath 100.

[0055] In some embodiments of this application, when the inner sheath 200 extends into the first passage 120, the elastic sheath tube 110 opposite to the extended portion of the inner sheath 200 expands and wraps around the inner sheath 200 extending into the first passage 120. In other embodiments of this application, when the inner sheath 200 extends into the first passage 120, the elastic sheath tube 110 opposite to the extended portion of the inner sheath 200 and the elastic sheath tube 110 connected to that portion expand, and the elastic sheath tube 110 opposite to the extended portion of the inner sheath 200 wraps around the inner sheath 200 extending into the first passage 120.

[0056] In this application, when the inner sheath 200 is removed from the first passage 120 of the outer sheath, the elastic sheath 110 rebounds. This means that when the inner sheath 200 is withdrawn from the first passage 120 of the elastic sheath 110, the elastic sheath 110 rebounds to its pre-expansion state. In some embodiments, when the inner sheath 200 is completely withdrawn from the first passage 120 of the elastic sheath 110, the deformed elastic sheath 110 rebounds. The elastic sheath 110 may rebound to its pre-expansion state, or it may rebound to a state between the pre-expansion and post-expansion states; this application does not specifically limit this. In other embodiments, when the inner sheath 200 is partially withdrawn from the first passage 120 of the elastic sheath 110, the deformed portion of the elastic sheath 110 that has detached from the inner sheath 200 rebounds. The rebound pattern is the same as in the previous embodiments and will not be described again here. In some other embodiments, when the inner sheath 200 is partially withdrawn from the first passage 120 of the elastic sheath 110, the elastic sheath 110 does not spring back. When the inner sheath 200 is completely withdrawn from the first passage 120 of the outer sheath elastic sheath 110, the elastic sheath 110 springs back in the same manner as in the previous embodiments, and will not be described again here.

[0057] In some embodiments of this application, the outer sheath 100 includes a natural state and an expanded state that can be interchanged. When at least a portion of the inner sheath 200 extends into the first passage 120, the outer sheath 100 changes from the natural state to the expanded state, and at least a portion of the elastic sheath 110 expands and wraps around the inner sheath 200 extending into the first passage 120. When the inner sheath 200 is removed from the first passage 120, the elastic sheath 110 rebounds and causes the outer sheath 100 to change from the expanded state back to the natural state. It is understood that the rebound state of the elastic sheath 110 can be a state completely consistent with the natural state, that is, a state close to the natural state (e.g., a state between the natural state and the expanded state). In addition, it is worth noting that when the interventional sheath assembly 10 is used in conjunction with an interventional device, the elastic sheath 110 has the ability to rebound to the natural state, but stops rebounding when it wraps around the interventional device, which does not conflict with the aforementioned description of the rebound performance of the elastic sheath 110.

[0058] In some embodiments of this application, the outer sheath 100 and inner sheath 200 of the interventional sheath assembly 10 are detachably connected. In the initial state, the outer sheath 100 and inner sheath 200 are relatively separated. During use, the outer sheath 100 and inner sheath 200 are assembled. In other embodiments, in the initial state, the outer sheath 100 and inner sheath 200 are in a pre-assembled state, that is, the distal end of the inner sheath 200 extends into the first passage 120. During use, the inner sheath 200 is further extended into the first passage 120.

[0059] It is understood that when the inner sheath 200 extends into the outer sheath 100 in this application, the outer sheath 100 wraps around the inner sheath extending into the outer sheath. This application does not specifically limit the cross-section of the outer sheath in its natural state. Any cross-sectional shape of the outer sheath that can guarantee the wrapping effect is within the protection scope of this application, and this application does not specifically limit it.

[0060] In some embodiments of this application, the cross-sectional shapes of the outer sheath 100 and the inner sheath 200 are both axisymmetric. The outer sheath 100 has a central axis, and the extension direction of the central axis is the first direction x in the figure. The cross-sectional shapes of the outer sheath 100 and the inner sheath 200 can be circular or other axisymmetric shapes. When the inner sheath 200 extends into the first passage 120 along the first direction x, the central axis of the inner sheath 200 is coaxially arranged with the central axis of the outer sheath 100. The outer sheath 100 is a cylindrical structure and therefore has two circumferential surfaces: the circumferential surface of the outer wall of the elastic sheath 110 is the outer circumferential surface, and the circumferential surface of the inner wall of the elastic sheath 110 is the inner circumferential surface. The axial direction of the outer sheath 100 refers to the direction in which the central axis extends; the circumferential direction refers to the circumferential direction of the outer perimeter of the cylinder; and the radial direction refers to the direction passing through the central axis in the radial plane, usually also referring to a straight line direction along the diameter or radius, or a straight line direction perpendicular to the central axis. The radial dimension generally refers to the radius or diameter of the axisymmetric part, and the circumferential dimension generally refers to the circumference of the axisymmetric part. Since the first passage 120 is formed by the elastic sheath 110, the radial dimension of the first passage 120 is equal to the radial dimension of the inner circumferential surface of the elastic sheath 110. It is understood that in this application, the axial, circumferential, radial, and circumferential surfaces of other components can be referenced to the aforementioned description of the outer sheath 100.

[0061] In some embodiments, the outer sheath 100 includes a natural state and an expanded state that can be interchanged. When at least a portion of the inner sheath 200 extends into the first passage 120, the outer sheath 100 changes from the natural state to the expanded state, and at least a portion of the elastic sheath 110 expands and encloses the inner sheath 200 extending into the first passage 120. When the inner sheath 200 moves out of the first passage 120, the elastic sheath 110 springs back and causes the outer sheath 100 to change from the expanded state back to the natural state. Figure 1 (a) Figure 2 (a) The outer sheath is in its natural state.

[0062] In some embodiments, combined Figure 3 and Figure 4 It can be seen that the expanded state includes a partially expanded state. In the partially expanded state, the inner sheath 200 passes through a portion of the first passage 120 along the axial direction of the outer sheath 100, and a portion of the elastic sheath 110 expands and wraps around the inner sheath 200 extending into the first passage 120. The expanded elastic sheath 110 can be an elastic sheath 110 corresponding to the inner sheath 200. Alternatively, the expanded elastic sheath 110 can also include an elastic sheath 110 corresponding to the inner sheath 200 and a portion of the elastic sheath 110 connected to that portion. That is, the outer sheath 100 wrapped around the inner sheath 200 gradually transitions to other parts.

[0063] In some embodiments, combined Figure 5 and Figure 6 It can be seen that the expansion state also includes the fully expanded state. In the fully expanded state, the inner sheath 200 passes through the entire first passage 120 along the axial direction of the outer sheath 100, and the entire elastic sheath 110 expands and wraps around the inner sheath 200 that extends into the first passage 120.

[0064] In some embodiments, the expanded state also includes another fully expanded state, not shown, in which the inner sheath 200 passes through the first passage 120 along the axial direction of the outer sheath 100, and the entire elastic sheath 110 expands and wraps around the inner sheath 200 extending into the first passage 120.

[0065] In some of these embodiments, Figure 5 and Figure 6 The inner sheath 200 is fully inserted into the outer sheath 100 and extends from the distal end of the first passage 120. In some implementations, the distal end of the elastic sheath 110 in the outer sheath 100 has a chamfered structure, so that the outer sheath 100 outside the inner sheath 200 wraps around the inner sheath 200, and the outer peripheral surface of the outer sheath 100 smoothly transitions to the outer peripheral surface of the inner sheath 200, reducing the difficulty of intervention of the intervention sheath assembly 10.

[0066] For ease of drawing and description, the x-direction in the figure is a straight line. However, both the outer sheath 100 and the inner sheath 200 have a certain degree of flexibility, which allows them to be inserted into blood vessels. Therefore, the extension direction of the central axis of the outer sheath 100 and the inner sheath 200 can also be curved.

[0067] It is understood that in this application, the proximal end refers to the end facing the operator or physician, and the distal end refers to the end away from the operator or physician.

[0068] In some implementations, the inner sheath 200 has less elasticity than the outer sheath 100, allowing the outer sheath 100 to have both a natural state and an expanded state. The outer sheath 100 can transition from its natural state to its expanded state when subjected to external force, and can spring back to its natural state when no external force is applied. Furthermore, the inner sheath 200 has greater rigidity than the outer sheath 100, resulting in better support and assisting the interventional device in reaching the designated location.

[0069] In some implementations, the distal end of the inner sheath 200 is chamfered to reduce friction when the inner sheath 200 extends into the outer sheath 100, thereby reducing the difficulty of assembling the outer sheath 100 and the inner sheath 200 and reducing the difficulty of operation.

[0070] In some implementations, the radial dimension of the first passage 120 in its natural state is smaller than the radial dimension of the outer surface of the inner sheath 200 away from its central axis. That is, the aperture of the first passage 120 in its natural state is smaller than the outer diameter of the inner sheath 200, so that when the inner sheath 200 intervenes in the first passage 120, it causes the outer sheath 100 to expand and change from its natural state to an expanded state.

[0071] The interventional sheath assembly 10 provided in this embodiment includes an outer sheath 100 comprising a natural state and an expanded state. When the inner sheath 200 is inserted into the first access passage 120, the inner sheath 200 expands the outer sheath 100, changing it from a natural state to an expanded state, thus enlarging the first access passage 120 to facilitate the subsequent intervention of interventional instruments. After the interventional instrument reaches the designated position, the inner sheath 200 is withdrawn, and the elastic sheath 110 rebounds and wraps around the surface of the interventional instrument, reducing the interventional diameter and preventing blood from flowing into the elastic sheath and forming a thrombus between the interventional instrument. Furthermore, the inner sheath 200 can be retained after withdrawal from the first access passage 120 and reinserted into the first access passage 120 when necessary, enabling repeated intervention of the inner sheath 200. After describing the overall structure of the interventional sheath assembly, the implementation of the outer sheath in the interventional sheath assembly is described below with reference to the accompanying drawings. Please refer to... Figure 7 , Figure 7 An example is shown. Figure 4 A schematic diagram of the partial cross-sectional structure of the interventional sheath assembly in region C.

[0072] Combination Figure 7 It is understood that in some embodiments, the elastic sheath 110 includes an elastic layer 111 and a lubricating layer 112, the lubricating layer 112 being located on at least one side of the inner and outer sides of the elastic layer 111, and the coefficient of friction of the lubricating layer 112 being less than the coefficient of friction of the elastic layer 111.

[0073] It is understood that both the elastic layer 111 and the lubricating layer 112 extend along the axial direction of the outer sheath 100, and the lubricating layer 112 is located on the side of the elastic layer 111 facing the first passage 120 and at least on the side away from the first passage 120.

[0074] In some implementations, the elastic layer 111 is made of a highly elastic and flexible material. The material of the elastic layer 111 includes at least one of polydimethylsiloxane (PDMS), polyurethane elastomer, and polyolefin elastomer. Such materials have advantages such as low viscosity, high elasticity, high temperature resistance, and chemical resistance. These materials exhibit high temperature stability; the molecular motion generated as temperature increases enhances the material's elasticity. The lubricating layer 112 is made of at least one of polyacrylamide (PAM), polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol. Such materials possess good hydrophilic properties; they also exhibit good cell compatibility and blood compatibility.

[0075] In some implementations, the elastic layer 111 is entirely composed of an elastic material. For example, the elastic layer 111 is a cylindrical elastomer that expands uniformly in the circumferential direction when the inner sheath 200 extends into the first passage 120. In other alternative implementations, the elastic layer 111 is composed partly of an elastic material and partly of a rigid material. For example, the elastic layer 111 includes multiple rigid pillars arranged circumferentially, each of which can extend axially, with an elastomer filling the spaces between adjacent rigid pillars. When the inner sheath 200 extends into the first passage 120, the elastomer deforms, changing the circumferential spacing between adjacent rigid pillars, thereby enveloping the inner sheath. In other alternative implementations, the elastic layer 111 is formed by a mesh of elastic material. When the inner sheath 200 extends into the first passage 120, the shape of the elastic material mesh changes, thereby adjusting the circumferential dimensions of the elastic layer. It is understood that the above implementation method only illustrates part of the structure of the elastic layer 111. Other structures that can realize the corresponding functions of the elastic sheath 110 are also within the protection scope of this application, and this application does not make specific limitations on them.

[0076] The interventional sheath assembly 10 provided in this embodiment has a lubricating layer 112 located on the side of the elastic layer 111 facing away from the first access passage 120, which can reduce the friction between the outer wall of the elastic sheath 110 and the blood vessel wall, and improve the permeability of the intervention. The lubricating layer 112 located on the side of the elastic layer 111 facing the first access passage 120 can reduce the friction between the inner wall of the elastic sheath 110 and the inner sheath 200 during the expansion process.

[0077] Figure 8 Another example is shown Figure 4 A schematic diagram of the partial cross-sectional structure of the interventional sheath assembly in region C.

[0078] Combination Figure 8 It is understood that in some embodiments, the elastic layer 111 is provided with a lubricating layer 112 on both the side facing the first passage 120 and the side away from the first passage 120.

[0079] The interventional sheath assembly 10 provided in this embodiment has a lubricating layer 112 on both the side of the elastic layer 111 facing the first passage 120 and the side away from the first passage 120. This reduces the friction between the outer wall of the elastic sheath 110 and the blood vessel wall, improving the permeability of the intervention, and also reduces the friction between the inner wall of the elastic sheath 110 and the inner sheath 200 during the expansion process.

[0080] In some embodiments, the elastic sheath 110 is a cylindrical elastic body. When the outer sheath 100 changes from its natural state to its expanded state, the elastic sheath 110 can expand by uniformly deforming radially, thereby increasing the radial dimension of the first passage 120. When the outer sheath 100 changes from its expanded state to its natural state, the elastic sheath 110 can rebound by uniformly deforming radially, thereby decreasing the radial dimension of the first passage 120. In some embodiments, the circumferential dimension of the outer sheath 100 is greater than or equal to 9F and less than or equal to 24F. This can also be understood as the outer sheath 100 having a maximum circumferential dimension of 24F when expanded, and a circumferential dimension of 9F when the outer sheath 100 expands and rebounds without external force.

[0081] In this application, the interventional sheath assembly 10 is compatible with various specifications of sheaths and instruments, has high compatibility, offers many options, and expands the scope of application.

[0082] Where F is a unit of circumference, 1F equals a circumference of 1mm, and the corresponding pipe diameter is approximately 0.33mm.

[0083] Understandably, when the elastic sheath 110 expands, its radial dimension (diameter) will increase, and consequently its circumferential dimension (circumference) will also increase; when the elastic sheath 110 rebounds without external force, its radial dimension (diameter) will decrease, and consequently its circumferential dimension (circumference) will also decrease.

[0084] The interventional sheath assembly 10 provided in this embodiment meets the interventional requirements of most commonly used interventional devices by making the circumferential dimension of the outer sheath 100 a maximum of 24F. By making the circumferential dimension of the outer sheath 100 a minimum of 9F, the interventional size of the outer sheath 100 is reduced, thereby reducing the difficulty of intervention.

[0085] After describing the implementation of the outer sheath in the interventional sheath group, the implementation of the inner sheath in the interventional sheath group will be described below with reference to the accompanying drawings. Figure 3 and Figure 4 It is understood that in some embodiments, the axial length of the inner sheath 200 is greater than the axial length of the outer sheath 100. This allows the inner sheath 200 to extend from the proximal end of the first passage 120 and pass through the outer sheath 100 along its axial direction, ultimately extending from the distal end of the first passage 120, enabling subsequent interventional instruments to reach the designated location through the second passage 210.

[0086] The axial length of the outer sheath 100 refers to its distance from the proximal end to the distal end, that is, the distance from the left end to the right end of the straightened outer sheath 100 in the figure. The axial length of the inner sheath 200 is similar.

[0087] In some embodiments, the material of the inner sheath 200 includes at least one of polyethylene or polytetrafluoroethylene.

[0088] The interventional sheath assembly 10 provided in this embodiment, by making the axial length of the inner sheath 200 greater than that of the outer sheath 100, allows the inner sheath 200 to extend from the proximal end of the first passage 120 and pass through the outer sheath 100 along its axis, ultimately extending from the distal end of the first passage 120, thus expanding the entire proximal to distal end of the first passage 120. Simultaneously, because the elasticity of the inner sheath 200 is less than that of the outer sheath 100, the inner sheath 200 provides better support than the outer sheath 100. After the inner sheath 200 completely passes through the outer sheath 100 and extends from the distal end of the first passage 120, subsequent interventional instruments can directly reach the designated location with the aid of the better-supporting inner sheath 200.

[0089] In some embodiments, the inner sheath 200 is a tearable sheath or a femoral artery sheath. The tearable sheath can be withdrawn from the proximal end of the interventional sheath assembly 10 after the interventional device is inserted to the designated location, and detaches from the outer sheath 100 and the interventional device after tearing outside the body. The tearable sheath is suitable for long-term support interventional procedures, where the interventional device can be a pumping catheter, etc. After withdrawal, the elastic sheath 110 rebounds and wraps around the surface of the pumping catheter. The pumping catheter and outer sheath 100 remain in the patient's blood vessels for a longer period, providing auxiliary pumping function through the pumping catheter. The femoral artery sheath is suitable for short-term support interventional procedures, where the interventional device can be a valve prosthesis, etc. After the valve prosthesis is inserted to the designated location, both the femoral artery sheath and outer sheath 100 can be withdrawn, leaving the valve prosthesis in the designated location.

[0090] Figure 9 A longitudinal cross-sectional schematic diagram of an example of an outer sheath mount and a fixed wing is shown.

[0091] After describing the implementation of the inner sheath in the interventional sheath assembly, the implementation of other components in the assembly will be described below with reference to the accompanying drawings. Figures 1 to 6 and Figure 9 It is understood that, in some optional embodiments, the interventional sheath assembly 10 further includes an outer sheath seat 300 and a fixing wing 400. The outer sheath seat 300 is connected to the proximal end of the outer sheath 100, and the outer sheath seat 300 has a fourth passage 310 that extends axially and communicates with the first passage 120. The fixing wing 400 is connected to the outer sheath seat 300 and is located on the side of the outer sheath seat 300 opposite to the fourth passage 310.

[0092] In some alternative embodiments, the radial dimension of the outer peripheral surface of the outer sheath 300 gradually increases and then remains constant along the line connecting the distal and proximal ends; that is, the outer peripheral profile of the outer sheath 300 is a combination of a cone and a cylinder. The proximal end of the outer sheath 100 at least partially covers the outer peripheral surface of the outer sheath 300, and the outer sheath 100 and the outer sheath 300 are sealed together by processes such as bonding.

[0093] In this embodiment, after the interventional sheath 100 is inserted, at least part of the outer sheath seat 300 and the fixing wing 400 are located outside the blood vessel, and the outer sheath 100 can be prevented from shifting inside the blood vessel by fixing the fixing wing 400 to the patient's skin.

[0094] Figure 10 A longitudinal sectional view of another example of the outer sheath and fixed wing is shown.

[0095] Combination Figure 10 It is understood that, in some optional embodiments, the interventional sheath assembly 10 further includes a balloon 500 and an inflation tube 600. The balloon 500 is connected to the outer sheath seat 300 and located within the fourth passage 310. The balloon 500 encloses and forms a third passage 510 communicating with the first passage 120. The inflation tube 600 communicates with the balloon 500 and is used to inflate the balloon 500 to reduce the radial dimension of the third passage 510 or to release gas from the balloon 500 to increase the radial dimension of the third passage 510. When the inner sheath 200 extends into the first passage 120 from the third passage 510, the balloon 500 can be inflated through the inflation tube 600 to reduce the radial dimension of the third passage 510 and wrap around the outer peripheral surface of the inner sheath 200 to fix the inner sheath 200. When the interventional device extends into the first passage 120 through the third passage 510, air can be inflated into the balloon 500 through the inflation tube 600 to reduce the radial dimension of the third passage 510 and wrap around the outer peripheral surface of the interventional device, thereby fixing the inner sheath 200. When the interventional device is a blood pumping catheter, the blood pumping motor in the blood pumping catheter is inserted into the blood vessel through the third passage 510 and the first passage 120. The blood pumping sheath in the blood pumping catheter, which is connected to the proximal end of the blood pumping motor, also extends into the first passage 120 through the third passage 510. Air can be inflated into the balloon 500 through the inflation tube 600 to reduce the radial dimension of the third passage 510 and wrap around the outer peripheral surface of the blood pumping sheath, thereby fixing the blood pumping sheath.

[0096] In some alternative implementations, in the first direction x, the balloon 500 occupies only a portion of the fourth passage 310, and the axial length of the balloon 500 is less than the axial length of the fourth passage 310.

[0097] In some alternative implementations, in the first direction x, the balloon 500 extends from the proximal end to the distal end of the fourth passage 310, and the axial length of the balloon 500 is equal to the axial length of the fourth passage 310.

[0098] In some alternative embodiments, the balloon 500 is attached to and surrounds the inner wall surface of the outer sheath 300 facing the fourth passage 310. Since the outer sheath 300 is made of rigid material, the radial dimension of the fourth passage 310 is fixed. Therefore, when the balloon 500 is inflated through the inflation tube 600, due to the support of the inner wall surface of the outer sheath 300, the balloon 500 can only expand towards the third passage 510, causing the radial dimension of the third passage 510 to decrease.

[0099] The interventional sheath assembly 10 provided in this embodiment, during long-term support-type interventional procedures, after the inner sheath 200 is withdrawn and the elastic sheath 110 rebounds and wraps around the outer periphery of the pumping catheter, can be inflated into the balloon 500 through the inflation tube 600, reducing the radial dimension of the third passage 510 until the balloon 500 also wraps around the outer periphery of the pumping catheter, thus fixing the pumping catheter and preventing displacement. This reduces the need for repeated positioning of interventional instruments under radiation conditions, lowering the difficulty of the procedure and the radiation risk. If it is necessary to withdraw the pumping catheter, simply deflate the balloon 500 through the inflation tube 600 to release the pumping catheter. Afterwards, the inner sheath 200 can be reinserted to achieve dilation and form a passage, facilitating the withdrawal of the pumping catheter.

[0100] Please refer to Figure 11 , Figure 11 A schematic diagram of an example interventional device is shown.

[0101] In addition, such as Figure 11 As shown, this application also provides an interventional device, including an interventional instrument 20 and an interventional sheath assembly 10 as shown in any of the above embodiments. The following description will use one of the interventional devices as an example.

[0102] In some embodiments of this application, the interventional sheath assembly 10 is detachably connected to the interventional device 20. The interventional device includes a first state, a second state, and a third state. In the first state, the interventional device 20 is separated from the interventional sheath assembly 10, the outer sheath 100 is in its natural state, and the inner sheath 200 is not inserted into the first passage 120. In the second state, at least a portion of the inner sheath 200 is inserted into the first passage 120, causing the outer sheath 100 to change from its natural state to a partially expanded or fully expanded state. In the partially expanded state, the inner sheath 200 passes through a portion of the first passage 120 along the axial direction of the outer sheath 100, and a portion of the elastic sheath 110 expands and encloses the inner sheath 200 inserted into the first passage 120. In the fully expanded state, the inner sheath 200 passes through the entire first passage 120 along the axial direction of the outer sheath 100, and the entire elastic sheath 110 expands and encloses the inner sheath 200 inserted into the first passage 120. In the third state, the outer sheath 100 is in an expanded state, with at least a portion of the outer sheath 100 fitted over the outer side of the inner sheath 200. The distal end of the interventional device 20 extends into the second passage 210 from the proximal end of the inner sheath 200 and extends out of the second passage 210 from the distal end of the inner sheath 200.

[0103] In some other embodiments, in the first state, the inner sheath 200 and the outer sheath 100 are pre-assembled. In some alternative embodiments, the interventional device further includes a fourth state in which the inner sheath 200 is removed from the first passage 120, at least a portion of the interventional instrument is located within the first passage 120, and at least a portion of the outer sheath 100 springs back and wraps around the surface of the interventional instrument, the radial dimension of the interventional instrument located within the first passage 120 being smaller than the radial dimension of the distal end of the interventional instrument.

[0104] In some embodiments of this application, the inner sheath 200 is removed from the first passage, and the inner sheath 200 is separated from the outer sheath 100.

[0105] In some other embodiments of this application, the inner sheath 200 is partially removed from the first passage, while a portion of the inner sheath 200 remains in the first passage.

[0106] For example, interventional device 20 is a blood pumping catheter. In the fourth state, the motor in the blood pumping catheter passes through the first passage 120, the sheath of the blood pumping catheter extends into the first passage 120, and the elastic sheath 110 wraps around the outer periphery of the sheath.

[0107] In some alternative embodiments, the interventional device further includes a guidewire (not shown) and a dilator (not shown), the guidewire being detachably connected to the interventional sheath assembly 10 for guiding the interventional sheath assembly 10 to a designated position; and the dilator being detachably connected to the distal end of the inner sheath 200.

[0108] Before use, the interventional device is in its first state, after which the guidewire is inserted into the blood vessel first. The user connects the dilator to the distal end of the inner sheath 200 externally, and inserts the combined dilator and inner sheath 200 into the outer sheath 100 through the first access 120, causing the outer sheath 100 to change from its natural state to a partially or fully dilated state; at this point, the interventional device is in its second state. Next, the combined dilator and interventional sheath assembly 10 is inserted into the blood vessel along the guidewire until the designated position is reached, after which the dilator is withdrawn. The interventional device is then inserted into the blood vessel through the second access 210 and the guidewire until the designated position is reached; at this point, the interventional device is in its third state.

[0109] Finally, the interventional device 20 can be withdrawn from the blood vessel together with the interventional sheath assembly 10. This scenario is suitable for use in short-term support type interventional procedures. In this case, the interventional device 20 can be a valve delivery device. After the valve prosthesis in the valve delivery device is inserted to the designated position, the valve delivery device and the interventional sheath assembly 10 can be completely withdrawn from the blood vessel.

[0110] Furthermore, after the third state, the inner sheath 200 can be withdrawn from the blood vessel first. Since the interventional device 20 is located within the interventional sheath assembly 10, the outer sheath 100 will rebound and wrap around the surface of the interventional device, at which point the interventional device is in the fourth state. This usage scenario is suitable for long-term support type interventional procedures. In this case, the interventional device 20 can be a blood pumping catheter, etc. After the inner sheath 200 is withdrawn, the elastic sheath 110 rebounds and wraps around the surface of the blood pumping catheter. The blood pumping catheter and the outer sheath 100 remain in the patient's blood vessel for a longer period of time, providing auxiliary blood pumping function to the patient through the blood pumping catheter.

[0111] In some alternative embodiments, the interventional device also includes a variable diameter sheath (not shown) that, in long-term support type interventional procedures, after the inner sheath 200 is withdrawn, the variable diameter sheath is inserted from the outer sheath seat 300 and the outer sheath 100 into the blood vessel to a designated location to achieve hemostasis.

[0112] It is understandable that interventional devices can produce the same technical effects as interventional sheaths, so I will not go into further detail here.

[0113] In addition, this application also provides a method for using an interventional device, applied to the interventional device. The method will be described below using one type of interventional device as an example, and includes the following steps:

[0114] Step S01: Insert the guidewire into the blood vessel.

[0115] In step S02, the expander is inserted into the second passage of the inner sheath, and the expander is connected to the distal end of the inner sheath 200. Then, the expanded and inner sheath 200 connected together are inserted into the first passage 120, and at least part of the elastic sheath 110 is expanded and wrapped around the outer surface of the inner sheath 200 that extends into the first passage 120.

[0116] Step S03: Insert the assembled dilator, inner sheath 200, and outer sheath 100 into the blood vessel along the guidewire.

[0117] Step S04: Remove the dilator, leaving the outer sheath 100 and inner sheath 200 inside the blood vessel.

[0118] Step S05: Insert the interventional device into the blood vessel through the pathway within the inner sheath 200.

[0119] In step S02, at least a portion of the inner sheath 200 needs to extend from the distal end of the first passage 120, so that the entire outer sheath 100 is squeezed and expanded.

[0120] In some optional embodiments, after step S05, the method further includes:

[0121] Step S06: Withdraw the inner sheath 200, leaving the interventional device and outer sheath 100 inside the blood vessel. The elastic sheath 110 rebounds and wraps around the surface of the interventional device in the second access.

[0122] Step S07: Inflate the balloon 500 to fix the interventional device to the inner sheath 200 through the balloon 500 and the outer sheath seat 300.

[0123] This method of use is suitable for long-term support type interventional surgery, in which the interventional device can be a blood pumping catheter, etc. After the sheath is torn open and withdrawn, the elastic sheath 110 rebounds and covers the surface of the blood pumping catheter. The blood pumping catheter and the outer sheath 100 remain in the patient's blood vessels for a long time and provide auxiliary blood pumping function to the patient through the blood pumping catheter.

[0124] In some optional embodiments, after step S05, the method further includes:

[0125] Step S061: Deliver the components within the interventional device to the designated location;

[0126] Step S062: Remove the interventional device, leaving the components inside the interventional device in the designated position;

[0127] Step S063: Remove the inner sheath 200 and the outer sheath 100.

[0128] This method of use is suitable for short-term support type interventional procedures. In this case, the interventional device can be a valve delivery device. After the valve delivery device inserts the internal valve prosthesis into the designated position, the femoral artery sheath and the outer sheath 100 can be withdrawn after the valve delivery device is withdrawn, leaving the valve prosthesis in the designated position.

[0129] In addition, this application also provides a sheath, including an elastic sheath extending along its axial direction and a first passage formed by the elastic sheath. The sheath includes a natural state and an expanded state that can be interchanged. In the expanded state, at least part of the elastic sheath expands and increases the radial dimension of the first passage. In the natural state, the elastic sheath springs back and decreases the radial dimension of the first passage.

[0130] It is understood that the sheath in this application can be any of the aforementioned interventional sheaths.

[0131] The expansion of the elastic sheath can be achieved by inserting other sheaths into the first access route, or by inserting other interventional devices into the first access route.

[0132] In some of the alternative embodiments, the expansion state includes a partially expanded state and a fully expanded state. In the partially expanded state, part of the elastic sheath expands and wraps around the inner sheath extending into the first passage. In the fully expanded state, the inner sheath passes through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath expands.

[0133] In some alternative embodiments, the elastic sheath includes: an elastic layer; and a lubricating layer located on at least one side of the elastic layer, the friction coefficient of the lubricating layer being less than that of the elastic layer.

[0134] In some alternative embodiments, the elastic layer is composed entirely of an elastic material, or a portion of the elastic layer is composed of an elastic material and another portion of it is composed of a rigid material, or the elastic layer is formed by a mesh of elastic material surrounding it.

[0135] In some alternative embodiments, the elastic layer is provided with a lubricating layer on both the side facing the first passage and the side away from the first passage.

[0136] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. An interventional sheath assembly, characterized in that, include: The outer sheath includes an elastic sheath tube extending along its axial direction and a first passage formed by the elastic sheath tube; The inner sheath has a second passage extending axially therein, and the outer sheath is configured such that when the inner sheath extends into the first passage, at least part of the elastic sheath expands and wraps around the inner sheath extending into the first passage, and the second passage is in communication with the first passage; when the inner sheath moves out of the first passage, the elastic sheath rebounds.

2. The interventional sheath assembly according to claim 1, characterized in that, The outer sheath includes a natural state and an expanded state that can be switched between each other. When at least part of the inner sheath extends into the first passage, the outer sheath changes from the natural state to the expanded state, and at least part of the elastic sheath expands and wraps around the inner sheath that extends into the first passage. When the inner sheath moves out of the first passage, the elastic sheath rebounds and causes the outer sheath to change from the expanded state to the natural state.

3. The interventional sheath assembly according to claim 2, characterized in that, The expansion state includes a partial expansion state, in which the inner sheath passes through a portion of the first passage along the axial direction of the outer sheath, and a portion of the elastic sheath expands and wraps around the inner sheath extending into the first passage.

4. The interventional sheath assembly according to claim 2, characterized in that, The expansion state includes a fully expanded state, in which the inner sheath extends through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath tube expands and wraps around the inner sheath extending into the first passage.

5. The interventional sheath assembly according to claim 2, characterized in that, The radial dimension of the first passage in its natural state is smaller than the radial dimension of the outer surface of the inner sheath away from its central axis.

6. The interventional sheath assembly according to claim 1, characterized in that, The elastic sheath includes: Elastic layer; A lubricating layer is located on at least one side of the inner and outer sides of the elastic layer, and the coefficient of friction of the lubricating layer is less than the coefficient of friction of the elastic layer.

7. The interventional sheath assembly according to claim 6, characterized in that, The elastic layer is entirely composed of elastic material, or a portion of the elastic layer is composed of elastic material and another portion is composed of rigid material, or the elastic layer is formed by a mesh of elastic material surrounding it.

8. The interventional sheath assembly according to claim 6, characterized in that, The elastic layer has a lubricating layer on both the side facing the first passage and the side away from the first passage.

9. The interventional sheath assembly according to claim 6, characterized in that, The material of the elastic layer includes at least one of polydimethylsiloxane, polyurethane elastomer, and polyolefin elastomer, and the material of the lubricating layer includes at least one of polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

10. The interventional sheath assembly according to claim 1, characterized in that, Also includes: An outer sheath seat is connected to the proximal end of the outer sheath, and the outer sheath seat has a fourth passage that extends along its axial direction and communicates with the first passage. A fixed wing is connected to the outer sheath seat, and the fixed wing is located on the side of the outer sheath seat opposite to the fourth passage.

11. The interventional sheath assembly according to claim 10, characterized in that, Also includes: A balloon is connected to the outer sheath seat and located within the fourth passage, the balloon enclosing and forming a third passage that communicates with the first passage; An inflation tube, connected to the balloon, is used to inflate the balloon to reduce the radial dimension of the third passage or to release gas from the balloon to increase the radial dimension of the third passage.

12. The interventional sheath assembly according to claim 1, characterized in that, The circumferential dimension of the outer sheath is greater than or equal to 9F and less than or equal to 24F.

13. The interventional sheath assembly according to claim 1, characterized in that, The elasticity of the inner sheath is less than that of the outer sheath.

14. An interventional device, characterized in that, The interventional device includes an interventional instrument and an interventional sheath assembly as described in any one of claims 1 to 13, wherein the interventional instrument is detachably connected to the interventional sheath assembly, and the interventional device includes a first state, a second state, and a third state; In the first state, the outer sheath is in its natural state; In the second state, at least a portion of the inner sheath extends into the first passage, causing the outer sheath to change from the natural state to a partially expanded state or a fully expanded state. In the partially expanded state, the inner sheath passes through a portion of the first passage along the axial direction of the outer sheath, and a portion of the elastic sheath expands and wraps around the inner sheath extending into the first passage. In the fully expanded state, the inner sheath passes through the entire first passage along the axial direction of the outer sheath, and the entire elastic sheath expands and wraps around the inner sheath extending into the first passage. In the third state, the interventional device extends into the second passage from the proximal end of the inner sheath and extends out of the second passage from the distal end of the inner sheath.

15. The interventional device according to claim 14, characterized in that, The interventional device further includes a fourth state in which the inner sheath is removed from the first passage, at least a portion of the interventional instrument is located within the first passage, and at least a portion of the outer sheath rebounds and wraps around the surface of the interventional instrument.

16. The interventional device according to claim 14, characterized in that, Also includes: A guidewire is detachably connected to the interventional sheath assembly, and the guidewire is used to guide the interventional sheath assembly to a designated position; An expander is detachably connected to the distal end of the inner sheath.

17. A sheath, characterized in that, It includes an elastic sheath extending along its axial direction and a first passage enclosed by the elastic sheath, the sheath comprising a natural state and an expanded state that can be interchanged, in the expanded state at least partially expanding and increasing the radial dimension of the first passage; in the natural state, the elastic sheath springs back and decreases the radial dimension of the first passage.

Images