A valve prosthesis that facilitates the capture of valve leaflets

Abstract

The present application relates to the field of medical devices, and specifically to a valve prosthesis that is convenient for capturing valve leaflets, comprising an expandable stent for support and anchoring, a positioning member for positioning and clamping autologous valve leaflets, and a delivery system for delivering the valve prosthesis, wherein the expandable stent has an inflow end and an outflow end, the positioning member comprises a connecting portion arranged at the distal end and a positioning portion at the proximal end, the expandable stent is provided with a plurality of connecting structures at the outflow end, the connecting structure is provided with a strut, and one end of the strut is connected to the connecting portion of the positioning member, and the other end of the strut is connected to the connecting structure; when the valve prosthesis reaches the target position, the positioning portion of the positioning member extends from the delivery system, and the two ends of the expandable stent are restricted by the delivery system, so that the proximal end of the strut is propped up toward the outside of the expandable stent relative to the distal end of the strut, and drives the positioning portion of the positioning member to prop up toward the outside of the expandable stent.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to a valve prosthesis that facilitates the capture of valve leaflets. Background Art

[0002] At present, aortic valve stents mainly include mechanically expandable stents, balloon-expandable stents and self-expanding stents. After the release of mechanically expandable stents and balloon-expandable stents, the open area of ​​the valve is small, precise positioning is impossible, and the transvalvular pressure difference is large. Although the transvalvular pressure difference and conduction block are small after the release of the self-expanding stent, the coaxiality after release is poor, and precise positioning is impossible, which can easily cause problems such as paravalvular leakage and valve slippage. Most aortic valve stents are currently designed for patients with aortic stenosis. For patients with aortic regurgitation, how to improve the prevention of regurgitation while retaining the function of the native valve leaflets, reducing the amount of implants, and at the same time ensuring the reliable anchoring of the implanted prosthesis in the heart to avoid problems such as falling off, are issues that urgently need to be solved in this field.

[0003] Patent CN201610009313.2 discloses an atrioventricular valve stent for puncture insertion and its delivery system, which relates to a prosthesis that can be inserted into the body, and in particular to a heart valve stent and its insertion surgical instrument, including an expandable outer stent, a valve and several fixed arms, the inverted hook portion of the fixed arm and the fixed arm forming a seesaw-like lever; the pull wire pulls the inverted hook portion to drive the fixed arm to extend outward and hook the leaflets of the mitral valve, fixing the valve stent to the atrioventricular valve; the intervalvular anti-regurgitation edge corresponding to the junction of the leaflets seals the gap at the junction to prevent paravalvular regurgitation. The delivery system includes an outer sheath, an inner core, and a push rod. The head end of the inner core is connected to the head end sheath. The front end of the valve stent is compressed in the head end sheath, and the rear end is compressed in the outer sheath. The push rod pushes and releases the valve stent from the outer sheath in a multi-stage segmented mode. The pull line connected to the valve stent cooperates with the intervalvular anti-regurgitation edge for placement, adjustment, or retrieval. The operation is convenient and safe, with a high success rate, and can effectively prevent paravalvular leakage. In this patented solution, the fixed arm is connected to the stent to form a "fulcrum", and the rear end of the fixed arm forms a hook portion. The hook portion and the other end of the fixed arm are preset at a certain angle. When the valve prosthesis enters the heart to clamp the native valve leaflets, the delivery sheath is used to press the hook portion, causing the other end of the fixed arm to tilt outward to facilitate the capture of the valve leaflets. However, in clinical operation, due to the preset angle between the barb and the fixed arm, and in the natural state, the barb expands outward, which makes it impossible to retract the fixed arm after it is separated from the sheath. In addition, the outward-turned barb will also increase the loading diameter of the delivery sheath during loading, which is not conducive to the transfemoral surgical approach.

[0004] In summary, the problems that urgently need to be solved in this field include: how to make the artificial valve leaflet more closely fit the shape of the native valve leaflet, not be restricted by the structure of the stent, and be able to be recovered after the positioning part is released, while also being able to be used for minimally invasive interventional surgery, so as to greatly reduce the harm caused by the surgery to the patient. Summary of the Invention

[0005] In view of the above and other concepts, this application is proposed. The main purpose of this application is to overcome some problems and shortcomings of the prior art.

[0006] According to one aspect of the present application, a valve prosthesis is provided for facilitating the capture of leaflets, comprising: an expandable stent for support and anchoring, a positioning member for positioning and clamping autologous leaflets, and a delivery system for delivering the valve prosthesis, wherein the expandable stent has an inflow end and an outflow end, the positioning member comprises a connecting portion arranged at the distal end and a positioning portion at the proximal end, the expandable stent is provided with a plurality of connecting structures at the outflow end, the connecting structure is provided with a strut, and one end of the strut is connected to the connecting portion of the positioning member, and the other end of the strut is connected to the connecting structure; when the valve prosthesis reaches the target position, the positioning portion of the positioning member extends from the delivery system, and the two ends of the expandable stent are restricted by the delivery system, so that the proximal end of the strut is propped up toward the outside of the expandable stent relative to the distal end of the strut, and drives the positioning portion of the positioning member to prop up toward the outside of the expandable stent.

[0007] According to one embodiment, the connecting structure is a grid-like structure, and the struts are arranged within the grid of the connecting structure; such a design has at least two advantages: first, when the valve prosthesis is compressed and loaded, the loading tube diameter will not increase, which is conducive to transvascular delivery; second, the struts are arranged within the grid, and when the positioning member does not capture the leaflet ideally or other problems occur with the valve prosthesis, the struts will not affect the recovery of the valve prosthesis at all, thereby improving the fault tolerance of the device.

[0008] According to one embodiment, in a natural state, the axial length of the connecting structure is greater than the length of the support rod; this allows the support rod to be within the grid of the connecting structure in either a loaded or natural state, utilizing the grid space of the connecting structure without increasing its loaded tube diameter.

[0009] According to one embodiment, the connection structure is substantially arranged in a diamond-shaped structure.

[0010] According to one embodiment, the middle end portion of the connecting structure is arched toward the outside of the expandable stent, and one end of the connecting structure in the outflow direction is bent or gathered toward the center of the expandable stent.

[0011] According to one embodiment, one end of the strut is fixedly connected to the connecting structure, the other end of the strut is free, and the other end of the strut is bent or tilted toward the inside of the expandable stent; the purpose of this design is that the connecting portion of the positioning member is connected to the other end of the strut, and in a natural state, the positioning portion of the positioning member can be tightly attached to the outside of the expandable stent, which significantly improves the clamping force of the positioning member and enhances the anchoring effect of the valve prosthesis.

[0012] According to one embodiment, in a natural state, the positioning portion of the positioning member is in close contact with the outside of the expandable stent; the design of the strut enables the positioning member to open to a larger angle toward the outside of the expandable stent when capturing the leaflets, and at the same time, after capturing the leaflets, the positioning member can provide a strong clamping force, so that the valve prosthesis can be stably anchored in the heart.

[0013] According to one embodiment, the support rod is provided with a recessed portion for connection, the connecting portion of the positioning member is provided with a raised portion, and when loading, the raised portion engages with the recessed portion; the engagement of the raised portion and the recessed portion can effectively increase the connection strength between the positioning member and the support rod.

[0014] According to one embodiment, the connecting portions of adjacent positioning members are cooperatively connected to the same support rod, and a sleeve member is provided at the connection between the connecting portion and the support rod.

[0015] According to one embodiment, the positioning member is arranged in a "U"-shaped structure, and after the valve prosthesis is implanted, the positioning portion of the positioning member is located at the root position of the native valve; further, when the valve prosthesis is used to treat the aortic valve, after the valve prosthesis is implanted, the positioning portion of the positioning member is located at the sinus bottom position of the aortic valve.

[0016] According to one embodiment, the positioning portion of the positioning member is provided with a buffer structure, and the buffer structure is arranged in a "V" or "U" shape; the buffer structure can prevent the positioning member from breaking due to stress concentration after compression loading.

[0017] According to one embodiment, after the positioning member captures the autologous leaflet, the inflow end of the expandable stent is released so that the autologous leaflet is clamped between the positioning member and the expandable stent, and then the outflow end of the expandable stent is released to complete the implantation of the valve prosthesis.

[0018] Compared with the prior art, the advantages and beneficial technical effects of this application include at least the following:

[0019] 1. Due to the size limitation of the opening of the positioning members, the existing valves with positioning members are difficult to insert into the sinuses during clinical operation due to different anatomical structures and insufficient opening of the positioning members. The surgeon needs to make repeated attempts to complete the insertion, which increases the difficulty of the operation and greatly prolongs the operation time. Different from the existing technology, one embodiment of the present application utilizes a strut to connect the positioning member, so that after the two ends of the expandable stent are compressed, one end of the strut gathers toward the center of the stent, and the other end of the strut drives the positioning member to the outside of the expandable stent, so that when the positioning member captures the native leaflet, the outward size of the positioning member can be significantly increased, making it easier to capture the leaflet.

[0020] 2. Different from the prior art, the connection structure in one embodiment of the present application is a grid-like structure, and the struts are arranged within the grid of the connection structure; this design has at least two advantages: first, when the valve prosthesis is compressed and loaded, the loading tube diameter will not increase, which is conducive to transvascular delivery; second, the struts are arranged within the grid. When the positioning member does not capture the leaflet ideally or other problems occur with the valve prosthesis, the struts will not affect the recovery of the valve prosthesis at all, thereby improving the fault tolerance of the device.

[0021] 3. Different from the prior art, in one embodiment of the present application, one end of the strut is fixedly connected to the connecting structure, the other end of the strut is free, and the other end of the strut is bent or tilted toward the inside of the expandable stent; the purpose of this design is that: the connecting portion of the positioning member is connected to the other end of the strut, and in a natural state, the positioning portion of the positioning member can be tightly attached to the outside of the expandable stent, which significantly improves the clamping force of the positioning member and enhances the anchoring effect of the valve prosthesis.

[0022] 4. Different from the prior art, in one embodiment of the present application, a recessed portion for connection is provided on the support rod, and a protrusion is provided on the connection portion of the positioning member, and when loading, the protrusion engages with the recessed portion; the engagement of the protrusion and the recessed portion can effectively increase the connection strength between the positioning member and the support rod.

[0023] 5. Different from the prior art, in one embodiment of the present application, the positioning portion of the positioning member is provided with a buffer structure, and the buffer structure is arranged in a "V" or "U" shape; the buffer structure can prevent the positioning member from breaking due to stress concentration after compression loading.

[0024] The embodiments of the present application can achieve other beneficial technical effects that are not listed one by one. These other technical effects may be partially described below and can be anticipated and understood by those skilled in the art after reading this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above features and advantages of these embodiments and other features and advantages and the manner in which they are achieved will become more apparent, and the embodiments of the present application may be better understood, by referring to the following description taken in conjunction with the accompanying drawings, in which:

[0026] Figures 1a-1c Schematic diagram of the overall structure of the expandable stent of the present invention.

[0027] Figures 2a-2d The structural diagram and connection diagram of the support rod of the present invention are shown in FIG. Figure 2b for Figure 2a A partial enlarged view of the circled part in the middle.

[0028] Figure 3a and 3b Schematic diagram of the buffer structure of the present invention.

[0029] Figures 4a-4d Schematic diagram of the release process of the expandable and releasable stent of the present invention.

[0030] The names of the parts indicated by the numbers in the accompanying drawings are as follows: 1-expandable stent, 11-inflow end, 12-outflow end, 13-connecting structure, 14-support rod, 141-recessed portion, 2-positioning member, 21-connecting portion, 211-protruding portion, 22-positioning portion, 221-buffer structure, 3-sleeve member, 4-delivery system. DETAILED DESCRIPTION

[0031] In the following description of the drawings and specific embodiments, details of one or more embodiments of the present application will be described. Other features, purposes and advantages of the present application will be clear from these descriptions, drawings and claims.

[0032] It should be understood that the illustrated and described embodiments are not limited in application to the details of the construction and arrangement of the components set forth in the following description or illustrated in the accompanying drawings. The illustrated embodiments may be other embodiments and can be implemented or executed in various ways. Each example is provided in an explanation of the disclosed embodiments, not in a limiting manner. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments of the present application without departing from the scope or essence of the disclosure of the present application. For example, a feature illustrated or described as part of one embodiment may be used in conjunction with another embodiment to still produce another embodiment. Therefore, the present application discloses such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0033] Likewise, it is understood that the phrases and terms used herein are for descriptive purposes only and should not be considered restrictive. The use of "include," "comprising," or "having" and variations thereof herein is intended to encompass the items listed thereafter and their equivalents, as well as possible additional items.

[0034] As used herein, “axial” refers to a direction generally along the central axis of the aorta at the surgical site, and “transverse” refers to a direction generally transverse to, preferably perpendicular to, the “axial” direction.

[0035] The present application will be described in more detail below with reference to different embodiments and examples of several aspects of the application.

[0036] In this application, the proximal end refers to the end close to the apex of the heart, and the distal end refers to the end away from the surgical apex of the heart.

[0037] Due to the size limitation of the positioning member opening, the existing valve with a positioning member is difficult to insert into the sinus during clinical operation due to different anatomical structures and insufficient opening of the positioning member. The surgeon needs to make repeated attempts to complete the insertion, which increases the difficulty of the operation and greatly prolongs the operation time. The solution disclosed in patent CN201610009313.2 is to connect the fixed arm to the stent. The point where the stent and the fixed arm are connected is defined as the fixed arm connection point. One end of the fixed arm connection point forms a barb. In its natural form, the barb is tilted toward the outside of the stent. When capturing the leaflet, the delivery sheath is used to press the barb so that the fixed arm is propped up toward the outside of the stent. However, this solution has at least the following defects: 1. Both the fixing arm and the barb part need to have a relatively high degree of rigidity to ensure that the barb part can lift up the fixing arm and that the fixing arm can effectively clamp the native valve leaflet, which will inevitably affect the compression and sheathing of the fixing arm, and the situation where the delivery system is difficult to recover the fixing arm after the fixing arm is released; 2. The barb part is naturally tilted toward the outside of the stent, which will increase the loading diameter of the delivery sheath tube, which is not conducive to transvascular delivery.

[0038] In one embodiment of the present invention, the invention comprises an expandable stent 1 for supporting and anchoring, a positioning member 2 for positioning and clamping the native valve leaflet, and a delivery system 4 for delivering the valve prosthesis. Figures 1a to 1cAs shown, the expandable stent 1 has an inflow end 11 and an outflow end 12, the positioning member 2 includes a connecting portion 21 and a positioning portion 22, and the expandable stent 1 is provided with a plurality of connecting structures 13 at the outflow end 12, and the connecting structure 13 is provided with a strut 14, and one end of the strut 14 is connected to the connecting portion 21 of the positioning member 2, and the other end of the strut 14 is connected to the connecting structure 13; when the valve prosthesis reaches the target position, the positioning portion 22 of the positioning member 2 extends from the conveying system 4, and the two ends of the expandable stent 1 are restricted by the conveying system 4, so that one end of the strut 14 is supported relative to the other end of the strut 14 toward the outside of the expandable stent 1, and drives the positioning portion 22 of the positioning member 2 to be supported toward the outside of the expandable stent 1.

[0039] According to one embodiment, the connection structure 13 is a grid structure. In this embodiment, the connection structure 13 is a grid of diamond structure, and the support rods 14 are arranged in the grid of the diamond structure. Figure 2a and 2b As shown; this design has at least two advantages: first, when the valve prosthesis is compressed and loaded, the loading tube diameter will not increase, which is conducive to transvascular delivery; second, the struts 14 are arranged in the grid. When the positioning member 2 does not capture the leaflet ideally or other problems occur in the valve prosthesis, the struts 14 will not affect the recovery of the valve prosthesis at all, thereby improving the fault tolerance of the device.

[0040] According to one example, in a natural state, the axial length of the connecting structure 13 is greater than the length of the support rod 14; this allows the support rod 14 to be within the grid of the connecting structure 13 in either a loaded or natural state, utilizing the grid space of the connecting structure 13 without increasing its loaded tube diameter.

[0041] According to one example, the middle end portion of the connecting structure 13 is arched toward the outside of the expandable stent 1, and one end of the connecting structure 13 in the direction of the outflow end 12 is bent or gathered toward the center of the expandable stent 1, as shown in FIG. Figure 2b shown.

[0042] According to one example, one end of the strut 14 is fixedly connected to the connecting structure 13, and the other end of the strut 14 is free, and the other end of the strut 14 is bent or tilted toward the inside of the expandable stent 1, as shown in FIG. Figure 2c As shown; the purpose of this design is that the connecting portion 21 of the positioning member 2 is connected to the other end of the support rod 14, so that in a natural state, the positioning portion 22 of the positioning member 2 can be closely attached to the outer side of the expandable stent 1, significantly improving the clamping force of the positioning member 2 and enhancing the anchoring effect of the valve prosthesis.

[0043] According to one example, in a natural state, the positioning portion 22 of the positioning member 2 is in close contact with the outside of the expandable stent 1; the design of the strut 14 enables the positioning member 2 to open to a larger angle toward the outside of the expandable stent 1 when capturing the leaflets. At the same time, after capturing the leaflets, the positioning member 2 can provide a strong clamping force, so that the valve prosthesis can be stably anchored in the heart.

[0044] According to one example, the support rod 14 is provided with a recessed portion 141 for connection, and the connecting portion 21 of the positioning member 2 is provided with a raised portion 211, and when loading, the raised portion 211 is engaged with the recessed portion 141, as shown in FIG. Figure 2d As shown; the engagement of the raised portion 211 with the recessed portion 141 can effectively increase the connection strength between the positioning member 2 and the support rod 14.

[0045] According to an example, the connecting portions 21 of the adjacent positioning members 2 are connected to the same support rod 14, and a sleeve member 3 is provided at the connection between the connecting portion 21 and the support rod 14, such as Figure 1b and 2d shown.

[0046] According to one example, the positioning member 2 is arranged in a "U"-shaped structure. After the valve prosthesis is implanted, the positioning portion 22 of the positioning member 2 is located at the root position of the native valve; further, when the valve prosthesis is used to treat the aortic valve, after the valve prosthesis is implanted, the positioning portion 22 of the positioning member 2 is located at the sinus bottom position of the aortic valve.

[0047] According to an example, the positioning portion 22 of the positioning member 2 is provided with a buffer structure 221, and the buffer structure 221 is arranged in a "V" or "U" shape. Figure 3a and 3b As shown; the buffer structure 221 can prevent the positioning member 2 from breaking due to stress concentration after compression loading.

[0048] According to one example, after the positioning member 2 captures the native valve leaflet, Figure 4a and 4b As shown, the inflow end 11 of the expandable stent 1 is released, as shown in FIG. Figure 4c As shown, the autologous valve leaflet is clamped between the positioning member 2 and the expandable stent 1, and then the outflow end 12 of the expandable stent 1 is released to complete the implantation of the valve prosthesis. Figure 4d shown.

[0049] The foregoing description of exemplary embodiments of the present application has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the present application to the precise configurations and / or constructions disclosed, and it is apparent that numerous modifications and variations may be made by those skilled in the art in light of the above teachings without departing from the present invention. It is intended that the scope and full range of equivalents of the present invention be defined by the claims appended hereto.

Claims

1. A valve prosthesis for facilitating leaflet capture, comprising an expandable stent for supporting and anchoring a valve, a positioning member for positioning and clamping a native valve leaflet, and a delivery system for delivering the valve prosthesis, wherein the expandable stent has an inflow end and an outflow end, and the positioning member includes a distal connection portion and a proximal positioning portion, characterized in that: The expandable stent is provided with a plurality of connecting structures at the outflow end, the connecting structure is provided with a strut, and one end of the strut is connected to the connecting portion of the positioning member, and the other end of the strut is connected to the connecting structure, the connecting portions of adjacent positioning members are cooperatively connected to the same strut, and a sleeve member is provided at the connection between the connecting portion and the strut; when the valve prosthesis reaches the target position, the positioning portion of the positioning member extends from the conveying system, and the two ends of the expandable stent are restricted by the conveying system, so that the proximal end of the strut is supported toward the outside of the expandable stent relative to the distal end of the strut, and drives the positioning portion of the positioning member to be supported toward the outside of the expandable stent.

2. The valve prosthesis for facilitating leaflet capture according to claim 1, characterized in that: The connection structure is a grid structure, and the support rods are arranged in the grid of the connection structure.

3. The valve prosthesis for facilitating leaflet capture according to claim 1 or 2, characterized in that: One end of the support rod is fixedly connected to the connecting structure, and the other end of the support rod is free, and the other end of the support rod is bent or inclined toward the inside of the expandable stent.

4. The valve prosthesis for facilitating leaflet capture according to claim 3, characterized in that: In a natural state, the positioning portion of the positioning member is in close contact with the outer side of the expandable stent.

5. The valve prosthesis for facilitating leaflet capture according to claim 1 or 2, characterized in that: The support rod is provided with a recessed portion for connection, the connecting portion of the positioning member is provided with a raised portion, and during loading, the raised portion engages with the recessed portion.

6. The valve prosthesis for facilitating leaflet capture according to claim 1, characterized in that: The positioning member is arranged in a "U"-shaped structure. After the valve prosthesis is implanted, the positioning portion of the positioning member is located at the root of the native valve.

7. The valve prosthesis for facilitating leaflet capture according to claim 6, characterized in that: The positioning portion of the positioning member is provided with a buffer structure, and the buffer structure is arranged in a "V" or "U" shape.

8. The valve prosthesis for facilitating leaflet capture according to claim 1, characterized in that: In a natural state, the axial length of the connecting structure is greater than the length of the support rod.

9. The valve prosthesis for facilitating leaflet capture according to claim 1, characterized in that: After the positioning member captures the native leaflet, the inflow end of the expandable stent is released, so that the native leaflet is clamped between the positioning member and the expandable stent, and then the outflow end of the expandable stent is released to complete the implantation of the valve prosthesis.

Images