A cardiovascular stent loading sheath and a retraction system for an advance stent sheath.

Abstract

This invention relates to a cardiovascular stent loading sheath and a retraction system for an advancing stent sheath. The cardiovascular stent loading sheath, through the deformation-sealing opening of a deformable element disposed on the sheath tube, achieves the purpose of sealing the sheath opening after stent deployment. This ensures that when the loading sheath retracts across the stent, the sheath end opening does not snag on the stent, effectively preventing stent displacement and reducing surgical risks.

Description

Technical Field

[0001] This invention relates to the field of cardiovascular disease access treatment technology, specifically to a cardiovascular stent loading sheath and a retraction system for an advance stent sheath. Background Technology

[0002] Cardiovascular disease is one of the most life-threatening and deadliest diseases in human history. Minimally invasive interventional surgery offers advantages such as less surgical trauma and shorter recovery time, significantly reducing surgical risks, alleviating patient suffering, and improving treatment outcomes. With continuous advancements in medical technology and the upgrading of equipment, minimally invasive cardiovascular interventional surgery has been widely applied clinically and has achieved significant therapeutic effects. Compared to traditional surgery, minimally invasive interventional surgery relies more heavily on the safety and effectiveness of instruments; therefore, continuous innovation in cardiovascular minimally invasive interventional medical devices is crucial for its further promotion. Cardiovascular stents, including vascular stents and valvular stents, are among the main products for treating cardiovascular diseases and have undergone rapid development and iteration in recent years, gaining widespread application in China. However, these cardiovascular stent devices still present some technical challenges and require continuous optimization and innovation.

[0003] like Figure 1 As shown, cardiovascular stents are delivered to the target location in the body by a loading sheath 110, and the sheath needs to be withdrawn after deployment. The loading sheath can be divided into two types according to the stent deployment method: forward deployment and retraction deployment. Forward deployment means the stent sheath moves forward during stent deployment, while retraction deployment means the stent sheath moves backward during stent deployment. In forward deployment, after the loading sheath 110 deploys the stent, it must first cross over the stent 100 before being withdrawn. In actual use, because the stent loading sheath needs to traverse a tortuous path, the end of the stent loading sheath almost always adheres to the wall. Therefore, in forward deployment, after stent deployment, the loading sheath 110 will adhere to one side of the stent 100, making it easy for the loading sheath to snag on the stent's apex 101 when retracting across the stent, leading to stent displacement, seriously affecting the treatment effect, and even causing serious medical accidents. Summary of the Invention

[0004] Based on the above description, the present invention provides a cardiovascular stent loading sheath to solve the technical problem that the forward loading sheath often gets caught on the stent when crossing the stent in the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] A cardiovascular stent loading sheath includes a stent sheath and a deformable element;

[0007] The support sheath includes a sheath tube and a core rod. The distal end of the sheath tube is closed and the proximal end is provided with an opening. The core rod extends into the sheath tube from the opening. An accommodating cavity is formed inside the sheath tube.

[0008] The deformable element is disposed on the sheath, and the deformable element deforms to close the opening.

[0009] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0010] The cardiovascular stent loading sheath provided in this application, through the deformation-sealing opening of the deformable element provided on the sheath tube, ensures that the opening at the end of the sheath will not snag on the stent when the loading sheath is retracted across the stent, effectively preventing stent displacement and reducing surgical risks.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the deformable element includes a self-closing structure disposed at the opening, the self-closing structure being configured to close without support inside the opening.

[0013] Furthermore, the self-closing structure includes a shape memory alloy skeleton and an elastic membrane. The shape memory alloy skeleton is connected to the edge of the opening and is shaped to close the opening. The elastic membrane is disposed on the outside or both the inside and outside sides of the shape memory alloy skeleton.

[0014] Furthermore, the shape memory alloy skeleton is configured in a funnel shape or a straight cylinder shape at its AF point temperature.

[0015] Furthermore, the shape memory alloy skeleton is a rod-shaped, U-shaped, or wavy shape with continuous bends, arranged with rods spaced apart.

[0016] Furthermore, the deformable component is an expansion component, which is connected to the core rod and at least partially disposed inside the sheath tube, and the expansion component blocks the opening after expansion.

[0017] Furthermore, the expansion member includes an outer segment and an inner segment. The expansion member is configured such that, after expansion, the outer segment is located outside the opening, and the inner segment is located inside the opening. A step is formed between the outer segment and the inner segment, and the end face of the step is in contact with the edge of the opening.

[0018] Furthermore, the accommodating cavity includes a support loading area near the proximal end and a non-support area near the distal end. An expansion member is connected to the distal end of the core rod, which is movably disposed inside the sheath 11. The expansion member is disposed in the non-support area before the support is released, and the expansion member is configured to move inside the sheath to fill and cover the opening.

[0019] Furthermore, the deformable component is a hat, the hat includes a hat frame, the core rod includes a core rod body and a sleeve fitted on the core rod body, the distal end of the core rod body is connected to the sheath tube, the sleeve is connected to the hat frame, and the hat frame is configured to be compressible into the sheath tube and return to the hat shape when withdrawn from the sheath tube.

[0020] Furthermore, the cap frame is made of shape memory alloy.

[0021] Furthermore, the cap frame includes a central elastic element and a plurality of connecting rod structures disposed outside the central elastic element. The plurality of connecting rod structures are disposed along the outer periphery of the central elastic element. Each connecting rod structure includes a first connecting rod and a second connecting rod hinged at its ends. The other ends of the first connecting rod and the second connecting rod are respectively connected to the two ends of the central elastic element. When the cap frame is inserted into the sheath tube, the central elastic element extends.

[0022] Furthermore, the cap frame is covered with an elastic membrane.

[0023] This application also provides a retraction system for an advance-mounted stent sheath, which includes a cardiovascular stent-loading sheath as described in any of the above.

[0024] Furthermore, it also includes a protective sheath with a distal opening, the protective sheath being disposed on the proximal side of the cardiovascular stent loading sheath for inserting the cardiovascular stent loading sheath. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the state in which the forward loading sheath is hooked onto the support when it is retracted in the prior art of this invention;

[0026] Figure 2 This is a schematic diagram of a first-type embodiment of a cardiovascular stent loading sheath provided by the present invention;

[0027] Figure 3 This is a schematic diagram of another state of a first-type embodiment of a cardiovascular stent loading sheath provided by the present invention;

[0028] Figure 4 This is a schematic diagram of an optional structure of the nickel-titanium alloy skeleton in the first embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the self-closing structure expanding into a funnel shape in the first embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of another optional structure of the nickel-titanium alloy skeleton in the first embodiment of the present invention;

[0031] Figure 7This is a schematic diagram of another optional structure of the nickel-titanium alloy skeleton in the first embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of a second embodiment of the cardiovascular stent loading sheath provided by the present invention, in which a balloon is used;

[0033] Figure 9 This is a schematic diagram of the structure of a second type of cardiovascular stent loading sheath provided by the present invention, in which the structure is an expandable structure;

[0034] Figure 10 This is a schematic diagram of the compression state of a third embodiment of a cardiovascular stent loading sheath provided by the present invention;

[0035] Figure 11 This is a schematic diagram illustrating the restored cap-shaped state of a third embodiment of a cardiovascular stent loading sheath provided by the present invention;

[0036] Figure 12 A schematic diagram of the cap frame of a third embodiment of a cardiovascular stent loading sheath provided by the present invention;

[0037] Figure 13 This is another structural schematic diagram of the cap skeleton of a third embodiment of a cardiovascular stent loading sheath provided by the present invention. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0040] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0041] like Figure 2-7As shown, this application provides a cardiovascular stent loading sheath, which includes a stent sheath 10 and a deformable element;

[0042] The sheath 10 includes a sheath tube 11 and a core rod 12. The distal end of the sheath tube 11 is closed and the proximal end is provided with an opening 111. The core rod 12 extends into the sheath tube 11 through the opening 111. A receiving cavity 11a is formed inside the sheath tube 11.

[0043] A deformable element is disposed on the sheath 11, and the deformable element deforms to close the opening 111.

[0044] As a first-class optional implementation of this application, the deformable component includes a self-closing structure 20 disposed at the opening, the self-closing structure 20 being configured to close in a state of no support inside the opening, that is, after the support 200 is released, the opening 111 of the sheath 11 automatically closes.

[0045] As a specific implementation of this embodiment, the self-closing structure 20 includes a shape memory alloy skeleton 211 and an elastic membrane 212. The shape memory alloy skeleton 211 is connected to the edge of the opening 111 and is shaped to close the opening 111. The elastic membrane 212 is disposed on the outside or on both the inside and outside sides of the shape memory alloy skeleton 211.

[0046] As a preferred embodiment, the shape memory alloy skeleton 211 is described below using a nickel-titanium alloy skeleton.

[0047] A soft, elastic membrane 212 sandwiches the nickel-titanium alloy skeleton in the middle, preventing it from contacting the stent 200 and blood vessels to avoid scratches or abrasions. During fabrication, the nickel-titanium alloy skeleton is shaped into a closed state, and then the elastic membrane 212 is applied to both the inner and outer surfaces of the skeleton. The skeleton can be designed as a flared, cylindrical, or semi-closed shape, depending on the elasticity of the membrane. This application process does not affect the shaping effect of the nickel-titanium alloy.

[0048] At room temperature, the nickel-titanium alloy skeleton is in a closed state. When loading the stent in vitro, the nickel-titanium alloy skeleton is first cooled to below the AF point (the first temperature of the nickel-titanium alloy). Then, a conical tool is used to expand the nickel-titanium alloy skeleton at the opening 111 into a funnel shape (the performance of the membrane needs to be considered during lamination to ensure that it can be expanded into a funnel shape). At low temperature, the nickel-titanium alloy skeleton can maintain the funnel shape, which is conducive to the stent 200 entering the sheath 11. That is, the self-expanding stent loading process is carried out in cold water or ice water below the AF point of the nickel-titanium alloy skeleton at the stent sheath port. After the stent 200 enters the sheath 11, at room temperature or when it enters the human body, the temperature is higher than the AF point of the nickel-titanium alloy skeleton, and the self-closing structure 20 will automatically close or return to the state of compressing the stent 200.

[0049] After the stent 200 is delivered to the designated position in the loading sheath, the stent is kept stationary by external control of the delivery system, and the sheath tube 11 is advanced to release the stent 200. Then, the self-closing structure 20 will close due to the lack of support, so that the opening 111 cannot catch the wave angle 201 of the stent 200. After the stent 200 self-expands or is expanded to the target size, the loading sheath is retracted to cross the stent 200 and withdrawn from the body.

[0050] Optionally, the nickel-titanium alloy skeleton 21 structure at the end of the support sheath 10 can be designed as a rod shape with intervals, a U-shape 511 with intervals, or a wave shape 611 with continuous bending, etc. Specifically, the nickel-titanium alloy skeleton is shaped into a closed state, and the inside and outside of this section are covered with an elastic membrane 212. The nickel-titanium alloy skeleton can drive the elastic membrane 212 to close together, and can be expanded into a trumpet shape at a temperature below the AF point.

[0051] It should be noted that the nickel-titanium alloy skeleton 21 has relatively low strength and is not a major part of the loading bracket 200, while the other parts of the bracket sheath 10 have higher strength and are the major parts of the loading bracket 200.

[0052] As a second optional implementation scheme of this application, such as Figure 8-9 As shown, the deformable component is an expansion component, which is connected to the core rod 12 and is at least partially disposed inside the sheath tube 11. After the expansion component expands, it blocks the opening 111.

[0053] In this type of solution, the expansion component can be a balloon 31 or an expansion structure 32 that expands after being injected with a specific substance such as gas or liquid. After the stent 200 is released, the balloon 31 is inflated or the expansion structure 32 is expanded to fill the opening 111, so that the opening 111 of the sheath 11 has no space to catch the stent 200, ensuring that the stent sheath 10 safely crosses the stent 200.

[0054] Taking balloon 31 as an example, it includes an outer segment 311 and an inner segment 312. The balloon 31 is configured such that after inflation, the outer segment 311 is located outside the opening 111, and the inner segment 312 is located inside the opening 111. A step is formed between the outer segment 311 and the inner segment 312, and the end face of the step is in contact with the edge of the opening 111.

[0055] Specifically, first, the balloon 31 is drained and vented and pressed tightly onto the core rod 12, taking up no space. Then, the stent 200 is installed into the stent sheath 10. After the stent 20 is sent to the target position through the sheath tube 11, the stent 20 is fixed in place. The sheath tube 11 is pushed forward to release the stent 200. Then, the balloon 31 is inflated. The inner section 312 of the balloon 31 is inside the sheath tube 11, and the diameter of the outer section 311 is larger than the outer diameter of the sheath tube 11. The step is attached to the opening 111 of the sheath tube 11. Then, the balloon 31 and the sheath tube 11 are pulled back together. The balloon 31 can effectively prevent the stent sheath from catching the stent wavy angle 201.

[0056] Taking the expansion structure 32 as an example, the accommodating cavity 11a includes a support loading area a1 near the proximal end and a non-support area a2 near the distal end. The expansion structure 32 is connected to the distal end of the core rod 12, which is movably disposed inside the sheath 11. The expansion structure 32 is disposed in the non-support area a2 before the support 200 is released. The expansion structure 32 is configured to move inside the sheath 11 and fill and cover the opening 111 when it moves to the opening 111.

[0057] The expansion structure 32 has a small initial volume and can be fixed in the stent loading area a1 or the non-stent area a2. It expands to a specific shape when it absorbs water, special substances, or is exposed to body temperature, and can fill the covering opening 111. In order not to affect the stent loading area a1, the expansion structure 32 is fixed at the position of the core rod 12 corresponding to the non-stent area a2. After the stent 200 is released, the expansion structure 32 is moved back to the vicinity of the opening 111 by retracting the core rod 12. The expanded expansion structure 32 can fill the opening 111 covering the stent sheath, so that the stent sheath 10 will not snag the stent 200 when it is retracted.

[0058] As a third optional implementation scheme of this application, such as Figure 10-13 As shown, the deformable part is a hat. The hat 40 includes a hat body frame 41, and the core rod 12 includes a core rod body 121 and a sleeve 122 fitted on the core rod body 121. The distal end of the core rod body 121 is connected to the sheath tube 11, and the sleeve 122 is connected to the hat body frame 41. The hat body frame 41 is constructed to be compressible and fit into the sheath tube 11 and to return to the hat shape when it is removed from the sheath tube 11.

[0059] Specifically, first, compress the cap frame 41 fixed on the sleeve 122 and insert it into the bottom of the sheath 11. Then, insert the bracket 200 into the sheath 11. If there is enough space, the cap 40 can also be located inside the bracket 200. After the bracket 200 reaches the target position, fix the bracket 200 in place, push the sheath 11 forward with the core rod body 121 to release the bracket 200, then pull back the sleeve 122 to remove the cap frame 41 from the sheath 11. Then, move the sleeve 122 forward to make the cap 40 cover the opening. Finally, pull back the core rod body 121 and the sleeve 122 together so that the bracket 200 will not be caught.

[0060] The cap frame 41 can be used alone as the cap 40, or it can be used in conjunction with an elastic membrane as in the first embodiment.

[0061] Optionally, the cap frame 41 can be a shape memory alloy structure, using the same shape memory alloy as in the first embodiment, such as a nickel-titanium alloy. It is compressed and inserted into the sheath 11, and can automatically recover after being removed from the sheath 11, so that it or the elastic membrane on it becomes the shape of a cap. Correspondingly, the nickel-titanium alloy cap frame 41 can also be designed as a claw shape, a wave shape, etc., which will not be elaborated here.

[0062] Optionally, the cap frame 41 can be a mechanical structure. For example, the cap frame 41 includes a central elastic member 412 and a plurality of connecting rod structures disposed outside the central elastic member 412. The plurality of connecting rod structures are disposed along the outer periphery of the central elastic member 412. The connecting rod structure includes a first connecting rod 413 and a second connecting rod 414 hinged at both ends. The other end of the first connecting rod 413 and the other end of the second connecting rod 414 are respectively connected to the two ends of the central elastic member 412. When the cap frame 41 is inserted into the sheath tube 11, the central elastic member 412 extends.

[0063] For example, an elastic membrane is placed on the first link 413. When the first link 413 and the second link 414 stretch the middle elastic element 412, the cap 40 shrinks and can be inserted into the sheath 11. When the cap 40 is released, the middle elastic element 412 automatically shrinks and shortens, and the first link 413 and the second link 414 are pulled closer. At the same time, the first link 413 drives the elastic membrane to return to its maximum shape, forming a cap shape that can cover the opening. The middle elastic element 412 is preferably a spring, but it can also be replaced with a nickel-titanium alloy component with memory properties, which can realize both elongation and automatic shortening functions.

[0064] In summary, the first type of implementation scheme employs a self-closing structure 20, which automatically closes the opening 111 of the sheath 11 after the stent 200 is released; the second type of scheme uses an expansion component composed of a balloon or other expansion structure to fill the sheath opening through expansion; and the third type of scheme uses a cap that can be placed on the sheath opening to achieve closure. All of these schemes achieve the purpose of closing the sheath opening after the stent is released, so that when the loading sheath is withdrawn across the stent, the opening at the sheath end will not catch on the stent, effectively preventing stent displacement and reducing surgical risks.

[0065] Based on the aforementioned cardiovascular stent loading sheath, this application provides a retraction system for an advance-type stent sheath, such as... Figure 3As shown, in addition to the structure of the cardiovascular stent loading sheath 100 described above, it also includes a protective sheath 300. The protective sheath 300 has a distal opening and is disposed on the side of the cardiovascular stent loading sheath 100 near the proximal end for inserting the cardiovascular stent loading sheath.

[0066] After the stent sheath 10 crosses the stent 200, it is first withdrawn into the protective sheath 300 and then withdrawn from the body together with the protective sheath 300. In the prior art, when a normal straight-tube stent sheath is withdrawn into the protective sheath 300, it is difficult to enter because of the misalignment. In this application, the stent sheath 10 is more likely to enter the protective sheath 300 after the opening is closed.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A retraction system for a forward-moving support sheath, characterized in that, Includes a cardiovascular stent loading sheath, the cardiovascular stent loading sheath comprising a stent sheath and a deformable element; The support sheath includes a sheath tube and a core rod. The distal end of the sheath tube is closed and the proximal end is provided with an opening. The core rod extends into the sheath tube from the opening. An accommodating cavity is formed inside the sheath tube. A deformable element is disposed on the sheath, and the deformable element deforms to close the opening. The deformable element includes a self-closing structure disposed at the opening. The self-closing structure is configured to close without support inside the opening. The self-closing structure includes a shape memory alloy skeleton and an elastic membrane. The shape memory alloy skeleton is connected to the edge of the opening and is shaped to close the opening. The elastic membrane is disposed on the outside or both the inside and outside sides of the shape memory alloy skeleton. The shape memory alloy skeleton is configured into a trumpet shape or a straight cylinder at its AF point temperature. Alternatively, the deformable component is an expansion member, which is connected to the core rod and at least partially disposed inside the sheath tube, and the expansion member blocks the opening after expansion; Alternatively, the deformable component may be a hat, the hat comprising a hat frame, the core rod comprising a core rod body and a sleeve fitted onto the core rod body, the distal end of the core rod body being connected to the sheath, the sleeve being connected to the hat frame, and the hat frame being configured to be compressible into the sheath and to return to a hat shape when withdrawn from the sheath.

2. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The shape memory alloy skeleton is a rod-shaped, U-shaped, or wavy shape with continuous bends, with rods spaced apart.

3. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The expansion member includes an outer segment and an inner segment. The expansion member is configured such that, after expansion, the outer segment is located outside the opening and the inner segment is located inside the opening. A step is formed between the outer segment and the inner segment, and the end face of the step is in contact with the edge of the opening.

4. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The accommodating cavity includes a stent loading area near the proximal end and a non-stent area near the distal end. An expansion member is connected to the distal end of the core rod, which is movably disposed inside the sheath. The expansion member is disposed in the non-stent area before the stent is released. The expansion member is configured to move inside the sheath and fill and cover the opening when it moves to the opening.

5. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The cap frame is made of shape memory alloy.

6. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The cap frame includes a central elastic element and multiple connecting rod structures disposed outside the central elastic element. The multiple connecting rod structures are arranged along the outer periphery of the central elastic element. Each connecting rod structure includes a first connecting rod and a second connecting rod hinged at its ends. The other ends of the first connecting rod and the second connecting rod are respectively connected to the two ends of the central elastic element. When the cap frame is inserted into the sheath tube, the central elastic element extends.

7. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, The cap frame is covered with an elastic membrane.

8. The retraction system of the forward-moving support sheath according to claim 1, characterized in that, It also includes a protective sheath with a distal opening, the protective sheath being disposed on the proximal side of the cardiovascular stent loading sheath for inserting the cardiovascular stent loading sheath.

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