Delivery System for a Recyclable Artificial Implant

Abstract

The present application discloses a delivery system for a recyclable artificial implant, which includes a catheter assembly and a control handle. The catheter assembly includes a sheath and an inner shaft assembly for loading and retrieving the artificial implant. The sheath includes: a tube body, which has opposite distal and proximal ends along its own axial direction, and the distal end is provided with a plurality of support rods arranged at intervals along the circumferential direction of the tube body. Each support rod has a relative retracted state and an everted state. It is characterized in that more than two connecting strips are arranged axially between adjacent support rods. Each connecting strip is reciprocally folded in the retracted state and has a tendency to straighten relative to the retracted state in the everted state; in the direction from the proximal end to the distal end, the self-straightening lengths of the connecting strips increase in sequence, and the axial spans L1 of the connecting strips increase in sequence. Both ends of the same connecting strip are connected to the corresponding side of the support rod, and the connection parts have the same axial position. The connecting strips on both circumferential sides of the same support rod are symmetrically arranged.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a delivery system for retrievable artificial implants. Background Art

[0002] A diseased or defective heart valve can be repaired or replaced by implanting a prosthetic heart valve (hereinafter referred to as an artificial implant). The artificial implant is loaded at the distal end of the delivery system and delivered to the surgical site by the intervention of the delivery system. If the artificial implant fails to be correctly positioned with the native annulus during the expansion process, serious complications will occur.

[0003] The existing method is to recapture the artificial implant, that is, to recompress and reposition the fully expanded or partially expanded artificial implant back into the sheath of the delivery system. This process can also be called retrieving the artificial implant. The terms "retrieving" and "recapturing" can be used interchangeably in the specification. After retrieval, it is then withdrawn from the body or repositioned.

[0004] The existing delivery systems have problems such as jamming, lack of smoothness during the retrieval operation, or the artificial implant damaging the sheath, resulting in retrieval failure. Summary of the Invention

[0005] This application provides a delivery system for loading and retrieving an artificial implant, which improves the smoothness of retrieving the artificial implant and avoids damage to the sheath during retrieval.

[0006] This application provides a delivery system for retrievable artificial implants, including a catheter assembly and a control handle connected to the proximal end of the catheter assembly. The catheter assembly includes a sheath for loading and retrieving the artificial implant and an inner shaft assembly. The artificial implant is connected to the distal end of the inner shaft assembly. The sheath includes:

[0007] A tube body, which has opposite distal and proximal ends along its own axis, and the distal end is provided with a plurality of support rods arranged at intervals along the circumferential direction of the tube body. Each support rod has a relative retracted state and an everted state. It is characterized in that more than two connecting strips are arranged axially between adjacent support rods. Each connecting strip reciprocally folds in the retracted state and has a tendency to straighten relative to the retracted state in the everted state;

[0008] In the direction from the proximal end to the distal end, the self-straightening lengths of the connecting strips increase in sequence, and the axial spans L1 of the connecting strips increase in sequence. Both ends of the same connecting strip are connected to the corresponding support rods on the corresponding side and the connection parts have the same axial position. The connecting strips on both circumferential sides of the same support rod are symmetrically arranged;

[0009] The area where the support rods are located is the expansion section. During the retrieval operation, the artificial implant acts on the distal end of the sheath, thereby driving the expansion section to switch from the retracted state to the everted state.

[0010] The following also provides several optional ways, which are not additional limitations to the above overall solution, but merely further supplements or optimizations. On the premise of no technical or logical contradictions, each optional way can be combined with the above overall solution separately, or can also be a combination between multiple optional ways.

[0011] Optionally, 3 to 4 connecting bars are arranged axially between adjacent two support bars; in the direction from the proximal end to the distal end, the axial span ratio of two adjacent connecting bars is 1:1.2 - 2; the axial span ratio of the connecting bar at the proximal most end and the connecting bar at the distal most end is 1:2 - 4.

[0012] Optionally, both ends of the same connecting bar are connecting ends, and the connecting ends are substantially perpendicular to the support bar and intersect.

[0013] Optionally, the support bar extends with equal width along the axis, and the connecting bar has a smooth transition at the turning part;

[0014] The turning part and the connecting end at the distal end of the same connecting bar are in the same axial position, and the two turning parts at the proximal end are in the same axial position.

[0015] Optionally, the shapes of the connecting bars are similar;

[0016] The connecting bar is approximately W-shaped, and both ends are turned outwards to be connected to the corresponding side support bars. The connecting bar includes a first section, a second section, a third section, and a fourth section that are connected in sequence along the circumferential direction. In the retracted state of each connecting bar, two adjacent sections are approximately in the shape of Ω.

[0017] Optionally, both ends of the connecting bar at the distal most end are tangent to the distal ends of the corresponding side support bars, and the turning part at the distal end of this connecting bar is used as the distal end of the expansion section.

[0018] Optionally, the distance L2 between the corresponding connecting ends of two adjacent connecting bars gradually increases from the proximal end to the distal end.

[0019] Optionally, between two adjacent connecting bars, the axial distance between the distal end of the proximal connecting bar and the proximal end of the distal connecting bar is L3, and in the same group of connecting bars, each L3 is approximately equal.

[0020] Optionally, the area where the support bar is located is the expansion section of the tube body. A part of the tube body on the proximal side of the expansion section adopts a multi-layer structure, that is, there is a metal reinforcement layer in the tube wall of this part. The metal reinforcement layer is a metal tube with a hollow structure, and the support bar and the connecting bar are an integral structure with this metal tube.

[0021] Optionally, both the inner and outer sides of the metal reinforcement layer are provided with polymer coating layers. The polymer coating layers on the inner and outer sides extend towards the distal end and cross the expansion section and are connected to each other at the distal end to form a protection section.

[0022] When the delivery system of the present application is in the recovery operation, the support rod in the sheath tube is subjected to different pulling forces of the corresponding connecting bars, causing itself to turn outwards in a curve, which is beneficial to the recovery of the artificial implant. In the outward-turned state, the expansion section where the support rod is located has strong structural strength and a flared shape, which is also beneficial to the recovery of the artificial implant and avoids damage caused by the artificial implant, improving the success rate of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Partial structural schematic diagram of the sheath tube (without a polymer coating layer in the expansion section) of an embodiment of the present application in the retracted state;

[0024] Figure 2 is Figure 1 Partial structural schematic diagram of the expansion section of the sheath tube in the expanded state in ;

[0025] Figure 3 Partial structural schematic diagram of the sheath tube of an embodiment of the present application when recovering an artificial implant;

[0026] Figure 4 Partial structural schematic diagram of the sheath tube of an embodiment of the present application in the retracted state;

[0027] Figure 5 is Figure 4 Partial structural schematic diagram of the sheath tube in the outward-turned state in ;

[0028] Figure 6 Partial structural schematic diagram of the sheath tube of another embodiment of the present application in the retracted state;

[0029] Figure 7 Structural schematic diagram of the sheath tube of an embodiment of the present application at the distal end;

[0030] Figure 8 Structural schematic diagram of the sheath tube of an embodiment of the present application for recovering an artificial implant in the body;

[0031] Figure 9 Structural schematic diagram of the delivery system of an embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS:

[0033] 1000. Sheath tube; 101. Proximal end; 102. Distal end;

[0034] 110. Tube body; 111. Polymer coating layer; 112. Protection section;

[0035] 120. Support rod; 122. Connection part; 130. Expansion section;

[0036] 140. Connecting strip; 140a. First connecting strip; 140b. Second connecting strip; 140c. Third connecting strip; 140d. Fourth connecting strip; 141. First section; 142. Second section; 143. Third section; 144. Fourth section; 145. Connecting end; 145a. First connecting end; 145b. Second connecting end; 146. Turning part; 147. Peak; 148. Trough; 147a. First peak; 148a. First trough; 148b. Second trough;

[0037] 150. Metal reinforcement layer; 190. Intermediate section;

[0038] 2000. Conveying system; 210. Catheter assembly; 220. Control handle; 230. Inner shaft assembly;

[0039] 3. Artificial implant. Detailed implementation manner

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0041] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may also be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments, and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] In this application, terms such as "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity or order of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0044] In the following drawings or text, an artificial implant is exemplified by an artificial heart valve. An artificial heart valve generally includes a deformable stent and leaflets connected within the stent. The stent is generally tubular in shape, and its side walls are a perforated grid structure. Unless otherwise specified, the shape or size of the grid structure is not strictly limited. The interior of the stent is a blood flow channel, and multiple leaflets cooperate with each other to control the opening and closing degree of the blood flow channel within the stent. For in-vivo positioning, a positioning structure that can interact with the surrounding native tissue, such as anchor spines, arms, etc., can also be provided on the outer periphery of the stent.

[0045] The stent can incorporate a wire control method to facilitate retrievability at any time during the release process. The stent itself can be formed by cutting a pipe or weaving a wire, and the leaflets can be connected to the stent by sewing, bonding, or integral molding.

[0046] The stent generally can have a connection structure that cooperates with the catheter assembly to define positions with each other and prevent unnecessary positional deviation during delivery. The artificial implant is in a radially compressed state, i.e., the loaded state, during interventional delivery, and is in a released state after releasing the restraint of the catheter assembly and radially expanding in the body.

[0047] When used to indicate direction, the proximal end in the text generally refers to the side adjacent to the operator (such as a doctor), and the distal end is the relatively far side. Along the interventional path, each component itself has a relative distal end and proximal end; theoretically, when the catheter assembly and the control handle are fully straightened, the line between the proximal end and the distal end is a straight line, which determines the axial direction, and correspondingly also determines the radial direction perpendicular to the axial direction and the circumferential direction arranged around the axial direction; when used to refer to a structure, the "end" in the text represents the end point of the structure or a certain point or area in that side direction or the specific structure connected to that point or area.

[0048] As Figure 8 and Figure 9 shown, an embodiment of the present application provides a delivery system 2000 for a retrievable artificial implant, including a catheter assembly 210 and a control handle 220. The catheter assembly 210 includes a sheath 1000 and an inner shaft assembly 230. An artificial implant is connected to the distal end of the inner shaft assembly 230. The sheath 1000 has an initial state of wrapping the artificial implant and a release state of completely exposing the artificial implant by moving relative to the inner shaft assembly 230. The proximal end of the catheter assembly 210 is connected to the control handle 220. The specific structures of the catheter assembly and the control handle can adopt existing technologies.

[0049] Further combined, Figures 1 to 5, the sheath 1000 of the present application (hereinafter referred to as the sheath) includes a tube body 110. The tube body 110 has opposite distal end 102 and proximal end 101 along its own axis, and the distal end 102 is provided with a plurality of support rods 120 arranged at intervals along the circumferential direction of the tube body. Each support rod 120 has a relatively retracted state and an everted state. The main difference between the retracted state and the everted state lies in the radial change of the support rod relative to the axis of the tube body. Axially on the tube body, the area where the plurality of support rods 120 are located is the expansion section 130. As Figure 1 shown, the expansion section 130 is in a straight tube shape in the retracted state; as Figure 2 shown, in the everted state of the expansion section 130, each part of its axis is away from the axis of the tube body. As Figure 3 shown, during the retrieval operation, the artificial implant acts on the distal end of the sheath 1000, thereby driving the expansion section 130 to switch from the retracted state to the everted state.

[0050] Two or more connecting strips 140 are arranged axially between adjacent support rods 120. Each connecting strip 140 is reciprocally folded in the retracted state, and has a tendency to be straightened relative to the retracted state in the everted state; in the everted state, the connecting strip 140 provides a pulling force for adjacent support rods 120 to approach each other to limit the further eversion of the support rods 120. From the proximal end to the distal end direction, the self-straightening length (i.e., the length along its own extension path) of each connecting strip 140 increases in turn. The two ends of the same connecting strip 140 are connected to the corresponding side support rods 120 and the connection parts have the same axial position. Different pulling forces are provided at different positions (i.e., the corresponding connection parts) in the axial direction of the tube body, so that the support rods 120 present an arc shape in the everted state, and the corresponding expansion section presents a trumpet shape, improving the smoothness during the retrieval of the artificial implant.

[0051] Since the connection parts of the same connecting strip 140 with the support rods 120 on both sides have the same axial position, the forces at each axial position of adjacent support rods 120 are the same, and adjacent two support rods 120 present the same curvature.

[0052] In the retracted state, the direction of reciprocal folding includes along the axis of the tube body, for example, extending from the support rod to the distal end or the proximal end, and then extending to the proximal end or the distal end, which is defined as one reciprocal fold. In some embodiments, the number of reciprocal folds is at least one.

[0053] The reciprocally folded connecting strip better adapts to the eversion of the expansion section 130, and the connecting strip is placed in the gap between the adjacent support rods 120, ensuring the structural strength of the expansion section, facilitating the in-vivo interventional delivery in the retracted state, and maintaining a stable posture (i.e., the trumpet shape) in the everted state to improve the efficiency of retrieving the artificial implant and avoid damage to the sheath by the artificial implant.

[0054] In the axial direction, the change in the straightened length of each connecting strip can adapt to the successive increase in the axial deformation of the support rod.

[0055] From the proximal end to the distal end, the method of successively lengthening the straightened length of each connecting strip 140 is as follows: in the retracted state, the number of reciprocating folds of each connecting strip is different, or the lengths of each connecting strip in the axial direction are different, or both are different.

[0056] For the convenience of description, in the following, a group of connecting strips refers to all the connecting strips between two adjacent support rods, and a pair of connecting strips refers to two connecting strips that are approximately in the same axial position and on both sides of a support rod.

[0057] In this embodiment, there are 4 connecting strips 140 arranged axially along the tube body between two adjacent support rods 120, which are the first connecting strip 140a, the second connecting strip 140b, the third connecting strip 140c, and the fourth connecting strip 140d from the distal end to the proximal end respectively; each connecting strip is reciprocally folded circumferentially in the retracted state (non-expanded state), and in the everted state (expanded state), relative to the retracted state, the two ends of each connecting strip move away from each other and tend to be straightened; from the proximal end to the distal end direction, the straightened lengths of each connecting strip increase successively, and the two ends of the same connecting strip are connected to the corresponding support rod 120 on the corresponding side and the connecting parts have the same axial position, as Figure 4 shown, the two ends, i.e., the connecting ends 145, of a single connecting strip 140 are respectively connected to the corresponding support rod 120 on the corresponding side, and the connecting ends 145 have the same axial position.

[0058] The connecting strip 140 has a wave crest 147 and a wave trough 148, wherein the wave crest 147 and the wave trough 148 face the axial direction of the expansion section 130, and the wave crest 147 is located at the distal end of the wave trough 148, and the numbers of the wave crest 147 and the wave trough 148 change according to the number of reciprocating folds of the connecting strip. The wave crests 147 of each of the first connecting strips 140a at the outermost distal end of the expansion section are located on the same first circumference (in the axial direction of the tube body); the wave troughs 148 of each of the first connecting strips 140a at the outermost distal end of the expansion section are located on the same second circumference, and the second circumference is parallel to the first circumference; in this embodiment, the two ends of each of the first connecting strips 140a are located on the same circumference as the wave crests 147 of each of the first connecting strips 140a. It should be noted that the connecting end of the connecting strip 140 and the support rod 120 is on the same circumference as the wave crest or the wave trough, but does not belong to the wave crest or the wave trough.

[0059] The second connecting strip 140b, the third connecting strip 140c, and the fourth connecting strip 140d have a shape similar to that of the first connecting strip 140a. The numbers of wave crests and wave troughs between the two ends of the second connecting strip 140b, the third connecting strip 140c, and the fourth connecting strip 140d are the same as those between the two ends of the first connecting strip 140a. For example, the connecting strip is approximately W-shaped, that is, it is reciprocally folded three times. In one embodiment, asFigure 4 As shown, each connecting strip has one crest 147 and two troughs 148; in another embodiment, as Figure 6 shown, each connecting strip 140 has two crests 147 and one trough 148.

[0060] The crests and troughs of the first connecting strip 140a, the second connecting strip 140b, the third connecting strip 140c, and the fourth connecting strip 140d are staggered in the circumferential direction. Taking Figure 4 the first connecting strip 140a and the second connecting strip 140b as an example, in the retracted state, the first trough 148a of the first connecting strip 140a is located between the first connection end 145a and the first crest 147a of the second connecting strip 140b; the crest 147a of the second connecting strip 140b is located between the first trough 148a and the second trough 148b of the first connecting strip 140a; the second trough 148b of the first connecting strip 140a is located between the second connection end 145b of the second connecting strip 140b and the first crest 147a.

[0061] In some other embodiments, 2 to 3 connecting strips 140 are provided axially along the tube body between adjacent two support rods 120.

[0062] In one embodiment, both ends of the same connecting strip 140 are connection ends 145. Axially, each connection end 145 is located on the distal side of the connecting strip 140 where it is located. First, the deformation amount of the expansion section 130 gradually increases from the proximal end to the distal end. And the connection end 145, as the force-bearing point, is arranged on the distal side of the connecting strip 140, which can better adapt to the deformation change of the expansion section 130 and reduce the risk of tearing of the inner and outer membranes (i.e., the following polymer coating layer) provided on the expansion section. For the same support rod 120, the connecting strips 140 on both circumferential sides are symmetrically arranged.

[0063] For example Figure 6 , in another embodiment, both ends of the same connecting strip 140 are connection ends 145. Axially, each connection end 145 is located on the proximal side of the connecting strip 140 where it is located.

[0064] In one embodiment, the support rod 120 extends with equal width along the axis, and the connecting strip 140 has a smooth transition at the turning part 146. This reduces the change in deformation stress during the eversion process of the connecting strip 140. The connecting strip 140 extends with equal width, and the width ratio of the connecting strip 140 to the support rod 120 is 1:1.5 to 2.5, preferably 1:1.7. The crest 147 and the trough 148 are located at the turning part 146.

[0065] In one embodiment, the shapes of the connecting bars 140 are similar. Similar shapes are understood to mean that the number of reciprocating folds and the extending directions between the connecting bars 140 are the same, etc. For example, the connecting bar 140 mentioned above is approximately W-shaped. Compared with the V-shaped bar that reciprocates and folds once, under the same amount of deformation, the stress generated by the V-shaped bar on the coating film is more concentrated, increasing the risk of tearing the coating film. The W-shaped structure can distribute the amount of deformation more evenly at multiple positions in the circumferential direction, making the stress acting on the inner and outer coating films more dispersed and uniform, reducing the risk of tearing the coating film.

[0066] However, if the number of folds is too large, the width of the connecting bar itself will inevitably need to be reduced in the limited space (the space between the two support rods), thereby reducing the structural strength of the connecting bar, and it is easy to warp and damage the coating film during the eversion process, and it also affects the storage of the artificial implant.

[0067] The two end portions of the W-shaped connecting bar 140 turn outward along the circumferential direction of the tube body and are connected to the corresponding support rod 120 (the connection position is the connection end 145). The connection end 145 intersects the support rod 120 substantially perpendicularly, with reasonable force, so that the support rod 120 will not twist and tear the polymer coating layer during the deformation process.

[0068] For the same connecting bar 140, the turning portion 146 at the distal end and the connection end 145 are in the same axial position, and the two turning portions 146 at the proximal end are in the same axial position.

[0069] In one of the embodiments, as Figure 4 shown, in the retracted state, among the connecting bars in the same group, in the direction from the proximal end to the distal end, the axial spans L1 of the connecting bars 140 increase in sequence. The axial span of the connecting bar is the axial straight-line distance from its proximal end to the distal end.

[0070] In one embodiment, the distance L2 between the corresponding connection ends 145 of two adjacent connecting bars 140 gradually increases from the proximal end to the distal end.

[0071] In one embodiment, between two adjacent connecting bars, the axial distance between the distal end of the proximal connecting bar and the proximal end of the distal connecting bar is L3. For example, Figure 4 in the axial distance between the distal end of the fourth connecting bar 140d and the proximal end of the third connecting bar is L3. In a group of connecting bars, each L3 is approximately equal.

[0072] For example, in the direction from the proximal end to the distal end, the ratio of the axial spans of two adjacent connecting bars 140 is 1:1.2 to 2, preferably 1:1.4. The ratio of the axial spans of the connecting bars 140 at the proximal most end and the distal most end is 1:2 to 4, preferably 1:2.8.

[0073] As Figure 4 and Figure 5As shown, the connecting strip 140 includes a first section 141, a second section 142, a third section 143, and a fourth section 144 that are sequentially connected along the circumferential direction. In the retracted state of each connecting strip, two adjacent sections present an approximate Ω shape; in the everted state, for the connecting strips 140a and 140b near the distal end, two adjacent sections thereof present an approximate V shape, and for the connecting strips 140c and 140d near the proximal end, two adjacent sections thereof still present an approximate Ω shape.

[0074] In one embodiment, both ends of the connecting strip 140 at the outermost distal end are tangent to the distal ends of the corresponding side support rods 120, increasing the structural strength of the distal ends of the support rods and the contact area with the artificial implant. Combining the foregoing, the turning portion 146 and the connecting end 145 at the distal end of the connecting strip are in the same axial position, that is, the turning portion 146 serves as the distal end of the expansion section 130, which is beneficial for the recovery operation.

[0075] In one embodiment, a part of the tube body 110 located on the proximal side of the expansion section adopts a multi-layer structure, and there is a metal reinforcement layer 150 in the tube wall of the tube body. The metal reinforcement layer 150 is a metal tube with a hollow structure, and the support rod 120 and the connecting strip 140 are an integral structure with the metal tube. For example, it is formed by integral cutting of the tube material. Figure 4 In this case, the support rod 120 is connected to the metal tube, and there is a fillet transition at the connection portion 122 between the two. When recovering the artificial implant, the part with the metal reinforcement layer 150 does not expand outward.

[0076] The metal tube is connected to the expansion section 130, and the length of the metal tube is not strictly limited to the whole body. For example, based on the axial proximal end, the end of the metal tube is on the proximal side of the end of the artificial implant (compressed in the tube body).

[0077] In one embodiment, the tube body 110 further includes an intermediate section 190 located at the proximal end of the expansion section. The bending performance of the intermediate section 190 is better than that of the expansion section 130, which is convenient for passing through the curved part in the body, such as the aortic arch.

[0078] Both the inner and outer sides of the metal reinforcement layer 150 are provided with a polymer coating layer 111. The polymer coating layer 111 is made of a transparent or opaque material. For the convenience of observation, Figure 1 the polymer coating layer in this case is shown in an opaque form. As Figure 7 shown, the polymer coating layer 111 extends distally to cover the expansion section 130, and the inner and outer polymer coating layers 111 meet and are connected to each other (for example, fused) at the distal end to form a protection section 112, improving the connection strength of the inner and outer polymer coating layers, better wrapping the expansion section, and reducing the risk of tissue damage during the intervention of the sheath tube.

[0079] The following is the process of using the delivery system of the present application to retrieve an artificial implant: The control handle 220 drives the sheath 1000 to move distally, causing the sheath 1000 to move axially relative to the inner shaft assembly 230. The expansion section of the sheath acts on the artificial implant 3 until the entire artificial implant retracts into the sheath.

[0080] During the retrieval process, each support rod turns outwards to present an arc of the same radian, making the inside of the expansion section smooth without inflection points, so that the artificial implant can be compressed more smoothly. In the everted state, the relatively strong structural strength and the flared shape of the expansion section are also conducive to the retrieval of the artificial implant, and avoid damage caused by the artificial implant, improving the success rate of the operation.

[0081] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification. When the technical features in different embodiments are embodied in the same drawing, the drawing can be regarded as simultaneously disclosing the combined examples of the respective embodiments involved.

[0082] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application.

Claims

1. A delivery system for a recyclable artificial implant, characterized in that, Comprising a catheter assembly and a control handle connected to the proximal end of the catheter assembly, the catheter assembly includes a sheath tube and an inner shaft assembly for loading and retrieving an artificial implant, the artificial implant being connected to the distal end of the inner shaft assembly, and the sheath tube comprising: A tube body having a distal end and a proximal end opposite to each other along its own axis, and the distal end being provided with a plurality of support rods arranged at intervals along the circumferential direction of the tube body. Each support rod has a relative retracted state and an everted state. It is characterized in that more than two connecting strips are arranged axially between adjacent support rods. Each connecting strip is reciprocally folded in the retracted state and has a tendency to straighten relative to the retracted state in the everted state; In the direction from the proximal end to the distal end, the self-straightening length of each connecting strip increases in sequence, and the axial span L1 of each connecting strip increases in sequence. Both ends of the same connecting strip are connected to the corresponding support rods on the corresponding side and the connecting parts have the same axial position. The connecting strips on both circumferential sides of the same support rod are symmetrically arranged; The area where the support rods are located is the expansion section. During the retrieval operation, the artificial implant acts on the distal end of the sheath tube, thereby driving the expansion section to switch from the retracted state to the everted state.

2. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, 3 to 4 connecting strips are arranged axially between adjacent support rods; in the direction from the proximal end to the distal end, the ratio of the axial spans of two adjacent connecting strips is 1:1.2 to 2; the ratio of the axial spans of the connecting strip at the proximalmost end and the connecting strip at the distalmost end is 1:2 to 4.

3. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, Both ends of the same connecting strip are connecting ends, and the connecting ends are substantially perpendicular to the support rods and intersect.

4. The delivery system of the recyclable artificial implant according to claim 1, wherein The support rods extend with equal width along the axis, and the connecting strips have a smooth transition at the turning parts; The turning part at the distal end of the same connecting strip and the connecting end are at the same axial position, and the two turning parts at the proximal end are at the same axial position.

5. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, The shapes of the connecting strips are similar; The connecting strip is approximately W-shaped, and the two ends are everted and connected to the corresponding support rods on the corresponding side. The connecting strip includes a first section, a second section, a third section and a fourth section connected in sequence along the circumferential direction. In the retracted state of each connecting strip, the adjacent two sections present an approximate Ω shape.

6. The delivery system of the recyclable artificial implant according to claim 1, wherein Both ends of the connecting strip at the distalmost end are tangent to the distal ends of the corresponding support rods on the corresponding side, and the turning part at the distal end of this connecting strip serves as the distal end of the expansion section.

7. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, The distance L2 between the corresponding connecting ends of two adjacent connecting strips gradually increases from the proximal end to the distal end.

8. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, Between two adjacent connecting strips, the axial distance between the distal end of the proximal connecting strip and the proximal end of the distal connecting strip is L3, and in the same group of connecting strips, each L3 is substantially equal.

9. The delivery system of the recyclable artificial implant according to claim 1, characterized in that, The area where the support rods are located is the expansion section of the tube body. A part of the tube body on the proximal side of the expansion section adopts a multi-layer structure, that is, there is a metal reinforcing layer in the tube wall of this part. The metal reinforcing layer is a metal tube with a hollow structure, and the support rods and the connecting strips are an integral structure with the metal tube.

10. The delivery system of the recyclable artificial implant according to claim 9, characterized in that, Both the inner and outer sides of the metal reinforcing layer are provided with polymer coating layers. The polymer coating layers on the inner and outer sides extend distally and cross the expansion section and are connected to each other at the distal end to form a protection section.

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