Covered stent and delivery system

Abstract

The application provides a covered stent and a delivery system. The covered stent comprises a stent body, a bare stent arranged at the distal end of the stent body, and a barb connected with the bare stent. The stent body comprises a first wave coil, and the barb is connected with the first wave coil. The free end of the barb extends in a direction away from the bare stent and gradually deviates from the surface of the stent body, so that the barb is at least partially radially stacked on the outer circumferential side of the stent body. The bare stent is radially constrained, the bare stent pulls the barb connected therewith, the pulled barb extrudes the stent body radially stacked therewith, and the stent body is radially compressed. According to the application, the barb is sunken to the stent body section, and the barb and the stent body are radially stacked, so that the covered stent can be stably and safely anchored to the blood vessel wall, and the form and / or position of the covered stent can be adjusted when the distal end of the bare stent is subjected to a radial compression force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of interventional medical devices, in particular to a covered stent and a delivery system. BACKGROUND

[0002] Abdominal aortic aneurysm (AAA) refers to the local abnormal expansion and bulging caused by the high-pressure blood flow impact under the factors such as hardening, injury, infection, etc. of the abdominal aorta, resulting in a tumor-like pathological condition with a diameter greater than 1.5 times of the normal diameter. After a long time of expansion, the blood vessel wall becomes very fragile, and the main danger of abdominal aortic aneurysm is the rupture of the aneurysm, which leads to severe internal bleeding, which is an acute condition that endangers life and is called a "bomb" in the human body. With the continuous development of interventional medical device technology and the continuous improvement of the medical skills of the operator, minimally invasive interventional surgery has become the first choice for the surgical treatment of abdominal aortic aneurysm.

[0003] In the interventional surgery of abdominal aortic aneurysm, the operator can send the delivery sheath tube of the delivery system loaded with the covered stent to the lesion site through the incision of the distal aorta such as the femoral artery of the human body, then release the covered stent, and fix the covered stent at the lesion site, so as to isolate the blood flow and the aneurysm of the lesion by the covered stent, reduce the influence of blood pressure on the lesion position of the artery, and at the same time make the blood flow through the hollow cavity of the covered stent to reestablish the blood circulation channel, so as to achieve the purpose of treatment on the basis of maintaining the needs of the patient's body, reducing the patient's pain and trauma.

[0004] At present, the covered stent for treating abdominal aortic aneurysm generally comprises a covered stent segment and a bare stent segment, the proximal end of the bare stent segment is connected with the distal end of the covered stent segment, the covered stent segment is axially formed with a channel for blood flow, and the distal end of the bare stent segment is designed with a barb structure to hook the covered stent on the blood vessel wall to prevent it from separating from the blood vessel wall or changing position in the blood vessel. Although the existing covered stent has solved the problem of abdominal aortic aneurysm to a great extent, it has defects that: after the covered stent is released from the delivery sheath tube, the covered part connected with the bare stent is expanded, the shape and position of the stent cannot be adjusted, the position of the stent may change during the release process due to the influence of blood flow pulsation and friction, and if the position changes greatly, it is easy to cause occlusion of the renal artery branch or fail to cover the lesion site, resulting in surgical failure and threatening the safety of the patient's life. SUMMARY

[0005] The purpose of the embodiments of the present application is to solve the technical problems that the shape and position of the entire covered stent cannot be adjusted once the covered part is expanded during the release of the existing covered stent, which requires high medical skills of the operator and has high surgical risk.

[0006] To solve the above technical problems, the present application provides a kind of covered stent, uses the technical scheme as follows:

[0007] The present application provides a kind of covered stent, the covered stent includes stent body, bare stent at the distal end of the stent body and barb connected with the bare stent, the stent body includes first wave coil, the barb is connected with the first wave coil, the free end of the barb extends towards the direction of gradually deviating from the surface of the stent body, away from the bare stent, so that the barb is at least partially radially stacked on the outer circumferential side of the stent body;The bare stent is radially constrained, the bare stent pulls the barb connected therewith, the barb pulled is extruded inward to the stent body radially stacked with it, so that the stent body is radially compressed.

[0008] In the preferred scheme of some embodiments of the covered stent of the present application, the barb and the wave rod of the first wave coil are at least partially radially stacked opposite to each other;The bare stent is radially constrained, the bare stent pulls the barb connected therewith, the barb pulled is extruded inward to the wave rod radially stacked opposite to it, and the wave rod drives the stent body to be radially compressed.

[0009] In the preferred scheme of some embodiments of the covered stent of the present application, the barb includes first barb and second barb, the distal ends of the first barb and the second barb are close to each other and connected with the bare stent at the same time, the free ends of the first barb and the second barb extend towards the direction of gradually deviating from the surface of the stent body, away from the bare stent, in a manner that the two gradually move away from each other, the barb is connected with the wave crest of the first wave coil, and the first barb and the second barb are respectively radially stacked opposite to at least part of the wave rod located on both sides of the wave crest.

[0010] In the preferred scheme of some embodiments of the covered stent of the present application, the extension length of the barb is between 1mm-10mm;And / or the extension length of the barb is between 0.6 to 0.8 times the wave height of the first wave coil, and / or the included angle of the barb deviating from the surface of the stent body ranges from 15° to 45°.

[0011] In the preferred scheme of some embodiments of the covered stent of the present application, a through hole is provided at the connection between the barb and the bare stent;And / or the stent body includes a main covering film, the first wave coil is connected to the distal end of the main covering film, the covered stent further includes a blocking film wrapped on the outer circumferential side of the connection between the barb, the bare stent and the first wave coil, and the blocking film is connected with the main covering film, and the free end of the barb penetrates out from between the two covering films.

[0012] In some preferred embodiments of the stent-graft of the present application, the bare stent comprises a plurality of V-shaped wave structures arranged in sequence and spaced apart in the circumferential direction, and each two adjacent V-shaped wave structures are connected by an arc-shaped hooking portion; the tip of each V-shaped wave structure is located at a proximal wave valley and connected to the barb, and the arc-shaped hooking portion is located at a distal wave peak.

[0013] In some preferred embodiments of the stent-graft of the present application, the barb is integrally formed with the bare stent.

[0014] In some preferred embodiments of the stent-graft of the present application, the first wave ring comprises a plurality of W-shaped wave structures arranged in sequence and connected end to end in the circumferential direction, each W-shaped wave structure has a first wave peak and first wave valleys symmetrically arranged on both sides of the first wave peak, the first wave ring comprises a plurality of first wave peaks, a plurality of first wave valleys, and a plurality of second wave peaks formed by connecting each two W-shaped wave structures, and the wave angle of the first wave peak is smaller than the wave angle of the second wave peak.

[0015] In some preferred embodiments of the stent-graft of the present application, the wave angle of the second wave peak is 1 to 3 times the wave angle of the first wave peak.

[0016] In some preferred embodiments of the stent-graft of the present application, when the barb comprises a first barb and a second barb, the first barb, the second barb, and the bare stent are all connected to the first wave peak in the first wave ring, and the first barb and the second barb are at least partially radially stacked opposite to the wave strut located on both sides of the first wave peak, respectively.

[0017] In some preferred embodiments of the stent-graft of the present application, when the bare stent comprises a plurality of V-shaped wave structures arranged in sequence and spaced apart in the circumferential direction, the second wave peak of the first wave ring is located between two adjacent V-shaped wave structures of the bare stent, so that the second wave peak is opposite to the arc-shaped hooking portion located at the distal wave peak.

[0018] In some preferred embodiments of the stent-graft of the present application, the stent body further comprises a second wave ring located on the proximal side of the first wave ring, the second wave ring is connected to the first wave ring by a main covering film, one wave peak of the second wave ring is opposite to one second wave peak of the first wave ring, and one wave valley of the second wave ring is opposite to one W-shaped wave structure of the first wave ring.

[0019] In some preferred embodiments of the stent-graft of the present application, the second wave ring is arranged axially spaced apart from or partially axially inserted with the first wave ring; when arranged spaced apart, the spacing distance between the second wave ring and the first wave ring is between 0 mm and 4 mm; when partially axially inserted, the insertion height of the second wave ring with the first wave ring is less than or equal to half of the wave height of the first wave ring.

[0020] In a preferred scheme of some embodiments of the stent graft of the present application, the stent body comprises a body segment at the distal end side and a long branch and a short branch connected in parallel to the proximal end side of the body segment, the branch lumen of the long branch and the short branch are communicated with the main lumen of the body segment, and the radial support force of the short branch is greater than that of the long branch connected in parallel.

[0021] To solve the above technical problems, the embodiments of the present application also provide a delivery system, which adopts the technical scheme as follows: the delivery system comprises the stent graft described above and a delivery device for loading and releasing the stent graft, the delivery device comprises a sheath core and a sheath tube sleeved outside the sheath core, and the bare stent at the distal end of the stent graft can be hooked on the anchor at the distal end of the sheath core; before the bare stent is separated from the anchor, the bare stent can drive the stent body of the stent graft to be radially compressed under the constraint of the constraint member at the distal end of the sheath core.

[0022] Compared with the prior art, the stent graft and the delivery system of the present application have the following beneficial effects:

[0023] The stent graft of the present application changes the conventional setting, and the barb is not provided at the distal end of the bare stent, but is sunken and connected with the first wave ring at the distal end of the stent body after being sunken to the periphery of the stent body and connected with the bare stent. This setting has the following effects: on the one hand, the bare stent and the barb can radially compress the stent body to a certain extent when the bare stent is radially constrained, so that the shape of the distal end of the stent can be adjusted during the release of the stent graft, the shape and / or position of the stent graft can be adjusted in the blood vessel as needed by the operator during the operation, which is beneficial to improve the success rate of the operation and reduce the risk of the operation, greatly reduce the one-time implantation accuracy of the stent graft during the operation, and further reduce the medical skill requirement of the operator. On the other hand, since the barb is provided at the periphery of the main graft, when the barb is released and anchored to the blood vessel wall, the main graft can block the anchoring position to avoid the formation of a new tumor body or a dissection caused by blood flow impact. At the same time, when the distal end of the stent graft is bridged with other stents (such as thoraco-abdominal stents or extension stents), the barb provided at the distal end is prevented from piercing other stents to cause internal leakage. In addition, the distal end of the stent graft can be resisted by the expanded bare stent in the circumferential direction, and the barb provided at the periphery of the main graft can be pierced into the blood vessel wall to form further anchoring, so that the stent graft is stably anchored at the predetermined position. BRIEF DESCRIPTION OF DRAWINGS

[0024] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention or corresponding prior art. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] in:

[0026] Figure 1 This is a three-dimensional structural schematic diagram of an exemplary film-coated stent of the present invention;

[0027] Figure 2 This is a side view of an exemplary film-covered stent of the present invention;

[0028] Figure 3 yes Figure 2 A schematic diagram of the planar unfolding at point A in the middle;

[0029] Figure 4 This is a top view of the exemplary first wave coil and barb combination of the present invention;

[0030] Figure 5 This is a three-dimensional structural diagram of the bare support, barb, and first wave coil of the present invention;

[0031] Figure 6 This is a three-dimensional structural diagram of an exemplary bare support and barb of the present invention;

[0032] Figure 7 yes Figure 6 A magnified view of a section at point B in the middle;

[0033] Figure 8 This is a three-dimensional structural diagram of the bare scaffold and barbs in an exemplary covered scaffold of the present invention;

[0034] Figure 9 This is a front view schematic diagram of the W-shaped bezel in the first bezel of the present invention;

[0035] Figure 10 This is a three-dimensional structural schematic diagram of the W-shaped bezel of the first bezel of the present invention;

[0036] Figure 11 This is a simplified front view of an exemplary covered stent of the present invention;

[0037] Figure 12 This is a simplified side view of an exemplary covered stent of the present invention;

[0038] Figure 13 This is a simplified front view of the exemplary covered stent of the present invention after being released from the abdominal aorta and installed at the corresponding location of the abdominal aortic aneurysm, in the first application scenario.

[0039] Figure 14 is a simplified front view of an exemplary covered stent of the present application in a second application scenario after the covered stent is released in the abdominal aorta and installed at a position corresponding to the abdominal aortic aneurysm; in this figure, the bare stent of the covered stent is connected to the thoracoabdominal stent;

[0040] Figure 15 is a simplified front view of an exemplary covered stent of the present application in a third application scenario after the covered stent is released in the abdominal aorta and installed at a position corresponding to the abdominal aortic aneurysm; in this figure, the bare stent of the covered stent is connected to the thoracoabdominal stent through the extension stent;

[0041] Figure 16 is a front view of another exemplary covered stent of the present application;

[0042] Figure 17 is a side view of another exemplary covered stent of the present application;

[0043] Figure 18 is a side view of another exemplary covered stent of the present application;

[0044] Figure 19 is Figure 17 is a planar development schematic diagram of C in

[0045] Figure 20 is a structural schematic diagram of an exemplary delivery system of the present application.

[0046] Reference signs in the drawings are as follows:

[0047] 1000, delivery system; 100, covered stent; 200, abdominal aorta; 210, abdominal aortic aneurysm; 300, thoracic aorta; 400, thoracoabdominal stent; 500, extension stent; 600, delivery device; 610, anchor; 620, sheath core;

[0048] 1, stent body; 11, body segment; 111, main covering; 112, first wave coil; 1121, wave rod; 1122, W-shaped wave frame; 1123, first wave peak; 1124, first wave valley; 1125, second wave peak; 113, second wave coil; 114, blocking film; 12, long branch; 121, third wave coil; 13, short branch; 131, fourth wave coil;

[0049] 2, bare stent; 21, V-shaped wave frame; 21a, bare wave rod; 22, arc-shaped hooking part;

[0050] 3, barb; 31, first barb; 32, second barb; 4, perforation;

[0051] 5, developing mark; 51, first developing point; 52, second developing point; 53, third developing point; 54, fourth developing point; 55, fifth developing point; 56, sixth developing point; 57, seventh developing point; 58, eighth developing point; 59, ninth developing point;

[0052] 6, connecting sleeve. DETAILED DESCRIPTION

[0053] 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 in the description herein is for describing particular embodiments only and is not intended to be limiting upon the scope of the present application, for example, the terms "length", "width", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like specify relative positions according to the orientations shown in the drawings and are for convenience not for limitation of the present technical solution.

[0054] The terms "comprise", "comprising", "include", "including", "have", "having" and any variations thereof in the specification and in the claims of the present application and in the above description of the drawings are intended to cover a non-exclusive inclusion; the terms "first", "second" and the like in the specification and claims of the present application or in the above description of the drawings are used to distinguish different objects, not to describe a particular order. The meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0055] In the specification and claims of the present application and in the above description of the drawings, when an element is referred to as being "fixed to" or "attached to" or "disposed on" or "connected to" another element, it can be directly or indirectly on or connected to the other element. For example, when an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element.

[0056] In addition, the reference herein to "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0057] It should be noted that in the field of interventional medical devices, the end close to the operator is generally defined as the proximal end, and the end away from the operator is defined as the distal end. According to this principle, the "proximal end" and "distal end" of any part of the stent are defined. The "axial direction" generally refers to the length direction of the stent during transportation, and the "radial direction" generally refers to the direction perpendicular to the "axial direction" of the stent. According to this principle, the "axial direction" and "radial direction" of any part of the stent are defined. The "middle section" generally refers to the part of the pipe / rod that distinguishes the two ends, and is not only the part located at the middle position of the pipe / rod.

[0058] The embodiment of the present application provides a covered stent 100, which can be used for repairing abdominal aortic aneurysm, arterial dissection and the like in the abdominal aorta 200 through interventional surgery. It should be noted that the application of the covered stent 100 is only exemplary and is not limited thereto.

[0059] As shown in Figures 1 to 3 and Figure 5 , the exemplary covered stent 100 of the present application comprises a stent body 1, a bare stent 2 and a barb 3, the bare stent 2 and the barb 3 are connected to each other and are arranged at the distal end (i.e. the upper part in Figure 1 ) of the stent body 1, and the barb 3 is connected to the stent body 1. Exemplarily, the distal end of the barb 3 is connected to the proximal end of the bare stent 2, and both are connected to the stent body 1 at the connection position. The extension direction of the barb 3 is opposite to that of the bare stent 2, the free end of the bare stent 2 extends towards the side away from the stent body 1 (i.e. extends towards the distal side), and the free end of the barb 3 extends towards the proximal side, so that the barb 3 is at least partially radially stacked on the outer circumferential side of the stent body 1, radially constraining the bare stent 2, the bare stent 2 pulling the barb 3 connected thereto, and the pulled barb 3 extruding the stent body 1 radially stacked thereon, so that the stent body 1 is radially compressed. It should be noted that the bare stent 2 of the present application comprises a wave coil structure, and the wave coil structure itself does not comprise a covering film. The bare stent 2 can be hooked on the anchoring member at the distal end of the sheath core during transportation. It should be further noted that the "radial stacking" of the present application means that the projection in the radial direction has overlap.

[0060] As shown in Figures 1 to 3As shown, the stent body 1 comprises a first wave 112. In other embodiments, the stent body 1 further comprises a main covering 111 connected with the first wave 112, and the first wave 112 is connected to the distal end of the main covering 111. Specifically, the first wave 112 is covered by the main covering 111 at the distal end of the stent body 1, and the main covering 111 can be arranged on the outside of the first wave 112, or on the inside of the first wave 112, or on both the inside and the outside of the first wave 112. The barb 3 and the bare stent 2 are both connected, and the barb 3 is connected with the first wave 112 of the stent body 1. Preferably, the barb 3 and the bare stent 2 are both connected at the connection thereof with the first wave 112 at the distal end of the stent body 1, and the free end of the barb 3 extends away from the bare stent 2 and gradually deviates from the surface of the stent body 1, so that the barb 3 is at least partially radially stacked on the outer periphery of the stent body 1. The bare stent 2 is radially constrained, the bare stent 2 pulls the barb 3 connected thereto, the barb 3 pulled is pressed inwardly against the stent body 1 radially stacked thereon, and the stent body 1 is radially compressed accordingly. It should be understood that when the stent body 1 is not provided with the main covering 111, the barb is pressed inwardly by the barb 3 pulled. When the stent body 1 is provided with the main covering 111, the barb is pressed inwardly by the barb 3 pulled, and due to the different shapes and positions of the barb, the barb can press the main covering 111, the first wave 112, or part of the main covering 111 and part of the first wave 112, as long as the stent body can be radially compressed. Of course, based on the compression effect and the consideration of avoiding the main covering being pierced, preferably, the barb is pressed inwardly by the first wave 112.

[0061] When the anchor in the delivery system is completely or partially inserted into the constraining member, the constraining member of the delivery system compresses the wave of the bare stent into the groove of the anchor, the bare stent pulls the barb connected thereto, and the barb and the bare stent pulled compress the stent body radially stacked thereon, so that the form of the covered stent is adjusted before the bare stent completely separates from the anchor, until the anchor is completely withdrawn from the constraining member after being adjusted to the appropriate position and angle, and at this time the bare stent hooked on the anchor is completely unfolded and separated from the anchor, thereby completing the in-vivo release of the covered stent.

[0062] The film covered stent 100 of the present application changes the conventional setting, and the barb 3 is not arranged at the distal end of the bare stent 2, but is arranged to be sunken to the periphery of the stent body 1, and is connected with the first wave ring at the distal end of the stent body 1 after being connected with the bare stent 2. The setting of this mode can make the bare stent and the barb compress the stent body to a certain extent when the bare stent is radially constrained, and can realize the regulation of the shape of the distal end of the stent during the release of the film covered stent. On the other hand, when the stent body is provided with the main film 111, the barb 3 is arranged at the periphery of the main film 111, so that when the barb is released and anchored to the blood vessel wall, the main film 111 can form a block at the anchoring position to avoid the impact of blood flow to form a new tumor or a dissection. At the same time, when the film covered stent is bridged with other stents (such as thoracico-abdominal stent 400 or extension stent 500, etc.) at the distal end, the barb arranged at the distal end is avoided to pierce other stents to cause internal leakage. In addition, the distal end of the film covered stent can be abutted on the blood vessel wall in the circumferential direction through the expanded bare stent, and the barb 3 arranged at the periphery of the main film 111 is pierced into the blood vessel wall to form further anchoring, so that the film covered stent 100 is stably anchored at the predetermined position.

[0063] Exemplarily, referring to FIG. 6, Figure 20 When the stent body 1 of the film covered stent 100 is partially released or completely released from the sheath tube of the delivery device 600, the stent body 1 is quickly expanded to be attached to the blood vessel wall. However, if the surgeon finds that the actual position of the stent body 1 is not the predetermined position, i.e., the stent body 1 is not released at the predetermined position, or although the stent body 1 is attached to the predetermined position, the surgeon finds that the target position to be attached is not the predetermined position during the operation, i.e., the original predetermined position is not accurate. In the release of the film covered stent 100, before the bare stent 2 completely separates from the anchor 621, the distal end of the bare stent 2 is subjected to a radial compression force due to the hooking of the anchor 621 of the delivery device 600 and the radial limiting of the constraint member 612. Thus, the bare stent 2 subjected to the radial compression force transmits the radial compression force to the barb 3 connected thereto, and the barb 3 transmits the radial compression force to the main film 111 of the stent body 1 radially arranged thereon and the first wave ring 112 connected with the barb 3. In addition, the first wave ring 112 is further subjected to radial compression under the pulling of the main film 111. Therefore, the distal end of the stent body 1 and the segment near the distal end are in different degrees of radial compression, and are not attached to the blood vessel wall. Thus, the surgeon can easily adjust the shape and position of the distal end of the film covered stent 100 in the blood vessel. In this way, on the one hand, the occlusion of the renal artery branch or the failure to cover the diseased site caused by the incorrect release of the film covered stent 100 can be avoided, and the safety of the patient can be ensured. On the other hand, the one-time implantation accuracy of the film covered stent 100 during the operation can be greatly reduced, and the skill requirement of the surgeon can be greatly reduced.

[0064] For example, the covered stent 100 may be an abdominal aortic stent, such as... Figure 13 As shown, the exemplary covered stent 100 of this invention can be directly and individually implanted into the abdominal aorta 200 at the location of an abdominal aortic aneurysm. For example... Figure 14 As shown, when a patient has already had a thoracic and abdominal main stent 400 implanted in the thoracic aorta 300, the distal end of the bare stent 2 of the covered stent 100 can be directly connected to the proximal end of the thoracic and abdominal main stent 400, depending on the patient's vascular structure and the length of the implanted thoracic and abdominal main stent 400, so that the covered stent 100 and the thoracic and abdominal main stent 400 directly cover the lesion area. Of course, as... Figure 15 As shown, when the lesion area is large, an extension stent 500 can be added to the proximal end of the main thoracic and abdominal stent 400, and the distal end of the bare stent 2 of the covered stent 100 can be connected to the proximal end of the extension stent 500 to achieve docking between the covered stent 100 and the main thoracic and abdominal stent 400. Clearly, this covered stent 100 allows surgeons to design more reasonable medical plans in one go based on different patient conditions, reducing the number of surgeries and risks.

[0065] Preferably, to ensure the connection strength and tensile strength between the bare support 2 and the barb 3, support body 1, etc., and to effectively transfer the radial constraint on the bare support 2, the barb 3 is integrally formed with the bare support 2. For example, as shown... Figure 6 As shown, the barb 3 and the bare support 2 can be integrally formed by laser cutting. Of course, they can also be integrally formed by other suitable processing methods. However, the barb 3 and the bare support 2 are not limited to being integrally formed.

[0066] It should also be noted that, in the embodiments of the present invention, the bare stent 2, barbs 3, first corrugated coil 112, etc., are preferably made of nickel-titanium alloy wire with good biocompatibility and superelasticity. Of course, they can also be made of other suitable materials. In addition, the main coating 111 of the stent body 1 can be single-layer, double-layer, or multi-layer. Preferably, the coating can be leak-proof and can be made of polyester, polyurethane, ePTFE coating, PET coating, or other polymer materials. Exemplarily, the various stents and corrugated coils of the coated stent 100 are made of nickel-titanium alloy wire, and the coating adopts a double-layer structure with inner and outer wrapping and is made of ePTFE material.

[0067] The covered stent 100 of the present application can effectively avoid the formation of new dissection aneurysm at the distal end of the bare stent 2, and can directly and intactly connect other stents at the distal end of the bare stent 2 according to the needs, by connecting the distal end of the barb 3 to the proximal end of the bare stent 2, connecting the first wave coil 112 at the distal end of the main covering 111, connecting the bare stent 2 and the barb 3 to the first wave coil 112 at the connection between the barb 3 and the bare stent 2, and radially stacking the barb 3 on the outer peripheral side of the stent body 1, and gradually deviating and exposing the proximal end of the barb 3 to the outer peripheral wall of the stent body 1, so as to sink the barb 3 to the main covering 111 segment of the stent body 1. It can also ensure that the barb 3 will not be impacted by the blood flow and has strong radial support force from the first wave coil 112, which is beneficial to improve the stability of anchoring and avoid the formation of new aneurysm or dissection near the anchoring position.

[0068] More importantly, because the barb 3 and the stent body 1 are radially stacked, after the stent body 1 of the covered stent 100 is released during the operation, the radial compression force can be directly transmitted to the main covering 111 and the first wave coil 112 by applying a radial compression force to the distal end of the bare stent 2, so that the distal end of the stent body 1 is in different radial compression forms at different positions. Therefore, the operator can adjust the form and / or position of the covered stent 100 in the blood vessel as needed during the operation, which is beneficial to improve the success rate of the operation and reduce the risk of the operation, greatly reduce the implanting precision of the covered stent 100 in the operation, and further reduce the medical skill requirements of the operator.

[0069] In order for those skilled in the art to better understand the present application, the following will combine the drawings to describe the present application. Figures 1 to 15 The technical scheme of the exemplary covered stent of the present application is described clearly and completely.

[0070] As a specific embodiment of the covered stent of the present application, as shown in Figure 1 , Figure 3 , Figure 5 , Figure 6 and Figure 8 , the first wave coil 112 of the stent body 1 includes a plurality of wave structures, and the barb 3 is radially stacked opposite to the wave rod 1121 of the first wave coil 112. Among them, the radial stacking opposite of the present application refers to at least partially overlapping in the projection in the radial direction, that is, the barb 3 located on the outer peripheral side of the first wave coil 112 and the wave rod 1121 of the first wave coil 112 at least partially overlap in the projection in the radial direction of the stent body 1. The bare stent 2 is radially constrained, the bare stent 2 pulls the barb 3 connected thereto, the barb 3 pulled inwardly extrudes and abuts against the wave rod 1121 of the first wave coil 112 radially stacked opposite thereto, and the wave rod 1121 drives the stent body 1 to be radially compressed.

[0071] Understandably, when the barb 3 is extruded, the barb 3 can directly transmit the radial compression force through the overlapping part of the barb 3 and the wave rod 1121, so that the radial constraint force of the bare stent 2 can be more effectively transmitted to the stent body 1; in addition, the self-expanding first wave ring 112 can provide radial support force for the barb 3, so that when the barb 3 is anchored to the blood vessel wall, the anchoring stability of the barb 3 is improved; at the same time, when the covered stent 100 is sheathed, the barb 3 abuts against the wave rod 1121, avoiding scratching or injuring the main covering film 111 due to the radial retraction of the barb 3.

[0072] As shown in Figure 1 , Figures 3 to 6 , Figure 8 To further improve the anchoring stability of the barb 3 and enhance the sheathing effect on the stent body 1, the barb 3 includes a first barb 31 and a second barb 32, the distal ends of the first barb 31 and the second barb 32 are close to each other and connected to the proximal end of the bare stent 2 at the same time, the proximal ends of the first barb 31 and the second barb 32 extend in a direction away from the bare stent 2 and gradually deviating from the surface of the stent body 1, and the proximal ends of the first barb 31 and the second barb 32 gradually move away from each other, as shown in Figure 5 and Figure 6 , the first barb 31 and the second barb 32 are arranged in a roughly eight-shaped manner, so that the first barb 31 and the second barb 32 can hook and anchor the blood vessel wall from different directions, which is beneficial to improve the anchoring reliability of the covered stent 100.

[0073] At the same time, as shown in Figure 5 , the first barb 31, the second barb 32 and the bare stent 2 are connected to the wave crest of the first wave ring 112 at the connection of the three, and the first barb 31 and the second barb 32 are respectively opposite to the radially overlapping wave rod 1121 located on both sides of the wave crest. The radial overlapping of the present application refers to at least partial overlap in the radial projection, that is, the projection of the first barb 31 and the second barb 32 in the radial direction of the stent body 1 is at least partially located in the projection of the wave crest corresponding wave rod 1121. That is, the projection of the first barb 31 and the wave rod 1121 on one side of the wave crest in the radial direction of the stent body 1 at least partially overlaps, and for the same reason, the projection of the second barb 32 and the wave rod 1121 on the other side of the wave crest in the radial direction of the stent body 1 at least partially overlaps, so that the action area of the radial compression force transmission between the barb 3 and the first wave ring 112 can be enlarged, and the radial compression force transmission effect is better.

[0074] To ensure good radial constraint effect between the barb 3 and the stent main body 1, and to avoid the barb 3 from piercing the blood vessel wall due to its excessive length, as an embodiment, the extension length of the barb is between 1mm and 10mm; preferably, the extension length of the barb is between 2mm and 8mm. As another embodiment, as shown in Figure 5 the extension length L of the barb 3 is between 0.6 and 0.8 times the wave height H of the first wave coil 112, wherein the range includes both 0.6 times and 0.8 times. Of course, to achieve the best effect, the extension length of the barb is between 1mm and 10mm, and the extension length L of the barb 3 is between 0.6 and 0.8 times the wave height H of the first wave coil 112.

[0075] Preferably, to further improve the anchoring stability of the barb 3 and the efficiency of transmitting radial compression force to the first wave coil 112, when the barb 3 is a double-prong structure, as shown in Figure 6 the included angle a between the first prong 31 and the second prong 32 of the barb 3 is between 20° and 30°. Specifically, the included angle a between the two prongs can be preferably 24° to make the barb 3 achieve the best state.

[0076] Continuing to refer to Figure 6 to facilitate the anchoring of the covered stent 100 and obtain a longer and effective anchoring length, the included angle y of the barb 3 deviating from the surface of the stent main body 1 is between 15° and 45°, wherein the range includes both 15° and 45°. Exemplarily, the included angle y of the proximal end of the first prong 31 and the second prong 32 deviating from the surface of the stent main body 1 can be preferably between 30° and 35°, and likewise, the range includes both 30° and 35°, to ensure that the barb 3 is anchored to the blood vessel wall at the best anchoring angle in the aortic blood vessel, and can quickly transmit radial force.

[0077] As shown in Figures 5 to 7 to radially stack the barb 3 on the stent main body 1, a through hole 4 is provided at the connection between the barb 3 and the bare stent 2. Specifically, the wave peak of the first wave coil 112 of the stent main body 1 can be fixedly connected with the bare stent 2 and the barb 3 by passing a connecting line (not shown in the figure, the connecting line can be a PTFE line) through the through hole 4, so that the barb 3 can be radially stacked on the first wave coil 112, and it is beneficial to increase the local contact area between the bare stent 2, the barb 3 and the first wave coil 112, and it is beneficial to ensure that the radial constraint received by the distal end of the bare stent 2 is more effectively transmitted to the stent main body 1 through the barb 3. At the same time, the provision of the through hole 4 can also reduce the overall weight of the covered stent 100.

[0078] Of course, in other specific embodiments, the barb 3 and the first wave coil 112 can also be radially stacked through other suitable ways or structures at the connection between the barb 3 and the bare stent 2.

[0079] Further, as shown in Figure 1 , the covered stent 100 further comprises a blocking film 114, wherein, outside the main covering film 111, the blocking film 114 covers the outer circumferential side of the junction of the barb 3, the bare stent 2 and the first wave coil 112, and the distal end of the blocking film 114 extends to the distal end of the main covering film 111, and the free end of the barb penetrates out from the proximal side between the main covering film and the blocking film, so that the distal end and the middle section of the bare stent 2 are exposed, and the proximal end and the middle section of the barb 3 are exposed. On the one hand, the barb 3 is radially arranged between the blocking film 114 and the main covering film 111, which can avoid the barb 3 from piercing the blood vessel wall to form a new tumor or / and a lamination, and improve the connection reliability of the junction structure of the above three, and facilitate the transmission of the constraint force. On the other hand, through the part of the bare stent 2 and the part of the barb 3 exposed to the blocking film 114, the hooking and anchoring are realized.

[0080] As shown in Figure 1 , Figure 3 , Figure 5 , Figure 6 and Figure 8 , the bare stent 2 comprises V-shaped wave frames 21 and arc-shaped hooking parts 22, wherein a plurality of V-shaped wave frames 21 are sequentially and spaced apart circumferentially, each V-shaped wave frame 21 comprises two bare wave rods 21a symmetrically arranged, the proximal ends of the two bare wave rods 21a are connected, the two bare wave rods 21a gradually move away from each other from the proximal end to the distal end, and the distal ends of the two bare wave rods 21a are respectively connected to one end of an arc-shaped hooking part 22. Each adjacent two V-shaped wave frames 21 are connected by an arc-shaped hooking part 22, so that the bare stent 2 has a ring-shaped wave coil structure, which is beneficial to improve the adhesion of the bare stent 2. Specifically, the tip of the V-shaped wave frame 21 is located at the proximal valley of the bare stent 2 and is connected to the distal end of the barb 3, and the arc-shaped hooking part 22 is located at the distal peak of the bare stent 2. In this way, the bare stent 2 can be hooked on the anchor of the sheath core assembly through the arc-shaped hooking part 22. Preferably, the arc-shaped hooking part 22 is substantially semicircular. This arrangement not only allows the bare stent to quickly detach from the anchor when it is not constrained by the constraining member, but also prevents the arc-shaped hooking part 22 from damaging the blood vessel wall, and prevents the other stent connected to the covered stent 100 from being pierced, thereby preventing the formation of a new tumor or lamination near the distal end of the covered stent 100.

[0081] As shown in Figures 1 to 3 , Figure 5 , Figure 9 and Figure 10As shown, to improve the sealing fit of the proximal end of the stent body 1 and improve the radial support force, the first wave ring 112 includes a plurality of W-shaped wave frames 1122 connected in sequence in the circumferential direction, wherein each W-shaped wave frame 1122 has a first wave crest 1123 and a first wave trough 1124 symmetrically arranged on both sides of the first wave crest 1123, that is, a W-shaped wave frame includes a first wave crest 1123 and two first wave troughs 1124, and every two W-shaped wave frames 1122 form a second wave crest 1125 at the connection therebetween. Specifically, since the first wave ring 112 includes a plurality of W-shaped wave frames 1122, the first wave ring 112 includes a plurality of first wave crests 1123 and a plurality of first wave troughs 1124 and a plurality of second wave crests 1125 formed by connecting every two W-shaped wave frames 1122. More specifically, the distal end of the first wave ring 112 has a plurality of first wave crests 1123 and second wave crests 1125, and the proximal end has a plurality of first wave troughs 1124, and the first wave crests 1123 and the second wave crests 1125 at the distal end are arranged at intervals. Preferably, the wave angle β (see Figure 9 ) of the first wave crest 1123 is less than the wave angle θ (see Figure 9 ) of the second wave crest 1125. Preferably, the wave angle θ (see Figure 9 ) of the second wave crest 1125 is 1 to 3 times the wave angle β (see Figure 9 ) of the first wave crest 1123, and this range includes 1 times and 3 times at both ends. Of course, in other embodiments, the multiples of the two can also be other suitable multiples.

[0082] Understandably, the two adjacent W-shaped wave frames 1122 are symmetrically connected, the two first wave troughs 1124 of each W-shaped wave frame 1122 are symmetrically arranged, and the wave crests of the first wave ring 112 are arranged in an alternating manner of “one large and one small” and uniformly distributed in the circumferential direction, so that the first wave ring 112 has a non-uniform wave shape, which facilitates the dispersion of stress concentration of the wave crests and wave troughs of the first wave ring 112, is beneficial to improve the fatigue life of the first wave ring 112, and further improves the reliability and service life of the covered stent 100.

[0083] As shown in Figure 1 , Figure 4 , Figure 5 and Figure 7 , when the barb 3 includes the first barb 31 and the second barb 32, the first barb 31, the second barb 32 and the bare stent 2 are connected at the connection of the three, and the first wave crest 1123 in the first wave ring 112, the first barb 31 and the second barb 32 are respectively radially laminated with the wave rod 1121 located on both sides of the first wave crest 1123, so as to realize the radial lamination of the barb 3 and the first wave ring 112 of the stent body 1. Specifically, the included angle α (see Figure 6 or Figure 7 ) between the first barb 31 and the second barb 32 is less than or equal to the wave angle β (see Figure 9 ) of the first wave crest 1123.

[0084] It can be understood that the first barb 31 and the second barb 32 of the barb 3 are located between the two wave rods 1121 forming the first wave crest 1123, preferably, the first barb 31 and the second barb 32 respectively at least partially overlap with the projection of the two wave rods 1121 of the first wave crest 1123 in the radial direction of the stent main body 1, on the one hand, when the bare stent 2 is subjected to a radial compression force, the radial compression force is more effectively transmitted through the first barb 31 and the second barb 32, so as to more quickly and better complete the adjustment of the shape and position of the covered stent 100; on the other hand, the first wave ring 112 can provide stronger radial support force for the barb 3, thereby making the anchoring of the barb 3 to the blood vessel wall more firm, so as to avoid the covered stent 100 from shaking or shifting under the impact of blood flow pressure, and at the same time, it can also prevent the double barbs of the barb 3 from scratching or injuring the main covering membrane 111 of the stent main body 1 when it is retracted, thereby avoiding the formation of new tumors or layers.

[0085] Further, as shown in Figure 1 and Figure 5 , when the bare stent 2 includes a plurality of V-shaped wave frames 21 arranged in sequence in the circumferential direction, the second wave crest 1125 of the first wave ring 112 is located between two adjacent V-shaped wave frames 21 of the bare stent 2, that is, the large wave crest is located between two adjacent V-shaped wave frames 21, so that the second wave crest 1125 of the first wave ring 112 is opposite to the arc-shaped hooking part 22 of the bare stent 2. Preferably, the arc-shaped hooking part 22 of the bare stent 2 and the top of the second wave crest 1125 of the first wave ring 112 are located on the same straight line. That is, the W-shaped wave frame 1122 and the V-shaped wave frame 21 correspond to each other on the same axial straight line. In this way, on the one hand, after the stent is implanted in the blood vessel and starts to work, the amount of wrinkles of the distal end covering membrane of the covered stent can be reduced when the distal end of the covered stent is subjected to a radial compression force of the blood vessel, so as to make the distal end of the covered stent better adhere to the wall, and prevent endoleakage from occurring at the distal end part of the stent after the stent is implanted in the blood vessel. On the other hand, the wave shape design of the W-shaped wave frame 1122 can further disperse the stress received by the distal end of the covered stent 100, thereby further improving the fatigue life of the covered stent 100. At the same time, the W-shaped wave frame 1122 can provide more effective radial force transmission when retracted.

[0086] Preferably, as shown in Figure 3 and Figure 5 , the number of W-shaped wave frames 1122 of the first wave ring 112 is the same as the number of V-shaped wave frames 21. In combination with Figure 4 and Figure 5 , the first wave ring 112 is provided with six W-shaped wave frames 1122, and the bare stent 2 is provided with six V-shaped wave frames 21. It should be noted that in clinical actual application, the number of W-shaped wave frames 1122 and V-shaped wave frames 21 can be determined according to actual needs.

[0087] As shown in Figure 1 , Figure 2、 Figure 11 and Figure 12 To improve the adhesion of the stent body 1 and ensure that the stent body 1 has sufficient radial support force, the stent body 1 further comprises a second wave 113 located at the proximal end side of the first wave 112. Preferably, the second wave 113 is provided with a plurality of second waves 113, and the plurality of second waves 113 are arranged at intervals along the axial direction of the stent body 1. In addition, the second wave 113 is connected with the main covering film 111, one wave crest of the second wave 113 is opposite to one second wave crest 1125 of the first wave 112, and one wave trough of the second wave 113 is opposite to one W-shaped wave frame 1122 of the first wave 112, so that the first wave 112 and the second wave 113 are arranged in a wave circumferential staggered manner, and the second wave 113 provides a strong axial support force, which is beneficial to improve the axial compression resistance of the distal end of the stent body 1 and prevent the distal end of the covering stent 100 from being shortened in the axial direction.

[0088] It should be noted that in the present embodiment, the first wave 112 and the second wave 113 can be fixed on the main covering film 111 by sewing, high-temperature pressing, hot melting sintering or bonding and the like. Exemplarily, in the present specific embodiment, the wave crest and the wave trough of the first wave 112 and the second wave 113 are all fixed together with the main covering film 111 by sewing with sewing threads through a sewing process.

[0089] As shown in Figure 1 、 Figure 2 、 Figure 3 、 Figure 11 and Figure 12 , the second wave 113 is arranged in partial overlap with the first wave 112 in the axial direction, wherein when arranged in partial overlap, the overlap height of the second wave 113 with the first wave 112 is less than or equal to half of the wave height of the first wave 112, and the vertical distance m between the first wave trough 1124 of the first wave 112 and the corresponding wave rod 1121 of the second wave 113 is 1mm-2mm, so that the covering stent 100 is more firm, so that the covering stent 100 can be compressed smaller when being transferred and transported in the sheath of the conveyor 600, and therefore it is beneficial to use a smaller size sheath for transportation. Correspondingly, the releasing force required by the covering stent 100 is smaller, so as to facilitate the implantation operation of the operator.

[0090] As shown in Figure 2 、 Figure 3 、 Figures 11 to 15 , in order to be suitable for the abdominal aorta 200, the stent body 1 comprises a main body section 11, a long branch 12 and a short branch 13, wherein the main body section 11 is located at the distal end of the stent body 1, the long branch 12 and the short branch 13 are connected in parallel to the proximal end of the main body section 11, and the branch lumens of the long branch 12 and the short branch 13 are communicated with the main lumen of the main body section 11.

[0091] It should be noted that in the stent body 1, the body section 11 is a covering film section of the main covering film 111 covering the first wave coil 112 and the second wave coil 113. The long branch 12 includes the third wave coil 121, and the short branch 13 includes the fourth wave coil 131. Similarly, the long branch 12 is a covering film section of a corresponding secondary covering film (not shown) covering the third wave coil 121, and the short branch 13 is a covering film section of a corresponding secondary covering film (not shown) covering the fourth wave coil 131. The main covering film 111 of the body section 11 and the secondary covering films are connected in one body by stitching or one-piece forming, etc., to ensure that the covering stent 100 is a one-piece structure.

[0092] In addition, the structure of the short branch 13 and the long branch 12, and the structure of the connection between the short branch 13 and the long branch 12 and the body section 11 can adopt existing structures or newly created structures, which will not be described here.

[0093] In this embodiment, in order to adapt to the blood vessel conditions of different patients and avoid the mutual extrusion of the two branches, which leads to the difficulty of the short branch 13 in passing through the guide wire and placing the extension stent 500, the radial support force of the short branch 13 is greater than that of the long branch 12 in the parallel section. It should be noted that the "parallel section" refers to one section of the long branch 12 opposite to the short branch 13, and the radial support force of the section is less than that of the short branch 13 opposite to it.

[0094] In order to realize that the radial support force of the short branch 13 is greater than that of the long branch 12, the fourth wave coil 131 of the short branch 13 and the third wave coil 121 of the long branch 12 can be set to different wire diameters, for example, the wire diameter of the fourth wave coil 131 of the short branch 13 is greater than the wire diameter of the third wave coil 121 of the entire long branch 12, or greater than the wire diameter of the third wave coil 121 of the long branch 12 interfering with the short branch 13. Alternatively, the fourth wave coil 131 of the short branch 13 and the third wave coil 121 of the long branch 12 can be set to different wave shapes, for example, all or part of the third wave coil 121 adopts a shape or structure with smaller radial support force, and the fourth wave coil 131 of the short branch 13 adopts a connected wave coil structure. Alternatively, the fourth wave coil 131 of the short branch 13 and the third wave coil 121 of the long branch 12 can be arranged in different wave coil positions, for example, the fourth wave coil 131 is densely arranged, and the third wave coil 121 is sparsely arranged. In this way, when the short branch 13 and the long branch 12 are extruded in the blood vessel, the inside of the short branch 13 can be relatively unobstructed, facilitating the entry of the guide wire and the docking of the extension stent 500.

[0095] It should be noted that the specific length of the long branch 12 and the short branch 13 can be determined according to actual needs. In addition, in order to ensure that the proximal end of the long branch 12 can be firmly anchored to the blood vessel wall in clinical use, the wire diameter of the plurality of third coils 121 at the proximal end of the long branch 12 is larger than that of the other third coils 121, or a different wave shape is used, so that the proximal end of the long branch 12 has stronger radial support force.

[0096] It should be further noted that in order to connect the coils of the covered stent 100 to ensure the structural strength of the covered stent 100, the covered stent 100 further comprises a plurality of connecting sleeves 6, wherein the coils on the main body segment 11, the short branch 13 and the long branch 12 are connected by the connecting sleeves 6 to connect a ring in the circumferential direction by the connecting sleeves 6. Exemplarily, the connecting sleeve is a steel sleeve, and the material can be preferably stainless steel, and the steel sleeve is connected by riveting. Or the connecting sleeve 6 is a nickel-titanium tube, which is fixed by laser welding.

[0097] Further, the connecting sleeves 6 on the main body segment 11 can also be used to fix the keels on the second coils 113; the connecting sleeves 6 on the short branch 13 can be used to fix the keels on the fourth coils 131, and the connecting sleeves 6 on the long branch 12 can be used to fix the keels on the third coils 121. As shown, in order to improve the fit of the long branch 12, the positions of the last three connecting sleeves 6 at the proximal end of the long branch 12 are gradually rotated.

[0098] In the present embodiment, as shown in Figure 2 , Figure 3 , Figures 11 to 15 In order to provide various position information of the covered stent 100 for the operator, facilitate the operator to judge whether the anchoring position of the covered stent 100 is accurate during the operation, and accurately adjust the position of the covered stent 100 according to the indicated position information, the covered stent 100 further comprises a plurality of developing marks 5, wherein the distal end of the stent body 1 is provided with different shapes of developing marks 5 at the corresponding positions to respectively indicate the starting positions of the short branch 13, the long branch 12, the main covering 111 and the position of the barb 3. Of course, different shapes of developing marks 5 are also provided at the related positions of the short branch 13 and the long branch 12.

[0099] Exemplarily, in one specific embodiment of the present embodiment, as shown in Figure 3 In the main body segment 11, the distal end of the stent body 1 is provided with four developing marks 5, which are respectively denoted as one first developing point 51, one second developing point 52 and two third developing points 53 for convenience of description, wherein, as shown in Figure 11As shown, the first imaging point 51 and the second imaging point 52 are located on both sides of the distal end of the stent body 1, respectively. The side corresponding to the first imaging point 51 indicates the side where the long branch 12 is located, and the side corresponding to the second imaging point 52 indicates the side where the short branch 13 is located and the starting position of the main cover 111 in the stent body 1. In addition, two third imaging points 53 are set at the front and rear of the stent body 1. During the operation, they are used to indicate the starting position of the main cover 111 and the position of the barbs 3, respectively, so as to facilitate the surgeon in determining the anchoring position of the covered stent 100 in the blood vessel or the thoracic and abdominal main stent 400.

[0100] It should be noted that the first developing point 51, the second developing point 52, and the third developing point 53 are marked differently. Specifically, they can be O-shaped developing points, figure-eight shaped developing points, and inverted V-shaped developing points, respectively. Of course, in other embodiments, they can also be developing points of other different shapes.

[0101] like Figures 11 to 15 As shown, in the short branch 13, a total of 7 imaging marks 5 are provided. For ease of explanation, these 7 imaging marks 5 are respectively designated as one fourth imaging point 54, one fifth imaging point 55, and five sixth imaging points 56. Correspondingly, in the long branch 12, a total of 3 imaging marks 5 are provided, and these 3 imaging marks 5 are respectively designated as one seventh imaging point 57, one eighth imaging point 58, and one ninth imaging point 59. As shown in Figure 11, different shapes of fourth imaging points 54 and seventh imaging points 57 are respectively provided on both sides of the distal bifurcation position of the short branch 13 and the long branch 12 to guide the surgeon to the bifurcation position of the long branch 12 and the short branch 13 with the main segment 11 via X-ray during the operation. For example, the fourth imaging point 54 and the seventh imaging point 57 are respectively O-shaped imaging points and inverted V-shaped imaging points. Of course, in other specific embodiments, other shapes of imaging points can also be used.

[0102] The second imaging point at the distal end of the short branch 13 is designated as the fifth imaging point 55. This serves as an intraoperative indicator of the optimal placement of the distal end of the extension stent 500. Specifically, at the location indicated by the fifth imaging point 55, the overlap area between the extension stent 500 and the short branch 13 is optimal, improving the stability of their connection and preventing endoleak. Figure 11 and Figure 12 As shown, the end of the short branch 13 has a total of five sixth developing points 56 to indicate the end position of the short branch 13. Exemplarily, the fifth developing point 55 and the sixth developing point 56 are respectively O-shaped and V-shaped developing points. Of course, in other embodiments, developing points of other shapes can also be used.

[0103] In addition, the middle section of the long branch 12 is marked by a second marker 5, which is an eighth marker 58, and is mainly used to indicate the optimal position for placing the distal end of the extension stent 500, so as to improve the connection stability and prevent internal leakage. The marker 5 at the proximal end of the long branch 12 is a ninth marker 59, which is mainly used to indicate the end of the long branch 12. Exemplarily, the eighth marker 58 and the ninth marker 59 are both O-shaped markers. Of course, in other embodiments, other shapes of markers can also be used.

[0104] Exemplarily, in the embodiment, each marker 5 can be an O-shaped marker, an 8-shaped marker or a V-shaped marker made of gold, platinum or other metals. The specific shape of the marker can be selected according to actual needs, as long as it can be easily distinguished, and will not be described here.

[0105] In other embodiments, please refer to Figures 16 to 18 As shown in FIG. 6, the second wave 113 is axially spaced apart from the first wave 112, and the axial spacing distance n between the second wave 113 and the first wave 112 is between 0 mm and 4 mm. Preferably, the axial spacing distance is between 1 mm and 2 mm. In this way, the stent graft 100 can be compressed smaller when loaded in the sheath of the delivery device 600, so that a smaller sheath can be used for delivery, and the release force required by the stent graft 100 is smaller, so that the implantation operation of the operator is facilitated.

[0106] Referring to Figure 20 Based on the stent graft 100 described above, the embodiment of the present application further provides a delivery system 1000, which comprises the stent graft 100 and a delivery device 600 for loading and releasing the stent graft 100. The delivery device 600 comprises a sheath core and a sheath tube (not shown) sleeved outside the sheath core. In the loaded state, the stent graft 100 is compressed between the sheath core and the sheath tube. The sheath core comprises an inner sheath core and an outer sheath core sleeved outside the inner sheath core, and the inner sheath core and the outer sheath core can axially move relative to each other. Referring to Figure 20As shown, the inner sheath core distal end is provided with a tip head 611 and a sleeve-shaped restraint 612 connected to the tip head proximal end, the outer sheath core is sleeved on the inner sheath core, and the outer sheath core distal end is provided with an anchoring member 621, the anchoring member 621 can be inserted or extended into the restraint 612 during the axial relative movement of the inner sheath core and the outer sheath core, the bare stent 2 of the covered stent 100 can be hooked on the anchoring member 621, and when the anchoring member 621 is inserted into the restraint 612, the bare stent 2 is radially compressed and gathered in the restraint 612, and the bare stent 2 can drive the stent body 1 of the covered stent 100 to be radially compressed. Before the bare stent 2 is separated from the anchoring member 621, the bare stent 2 can drive the stent body 1 of the covered stent 100 to be radially compressed under the restraint of the restraint 612 at the sheath core distal end.

[0107] That is, after the stent body 1 of the covered stent 100 is partially or completely released, before the bare stent 2 is completely separated from the anchoring member 621, that is, the bare stent 2 is still hooked on the anchoring member 621, at this time the distal end of the bare stent 2 is radially gathered in the restraint 612 at the sheath core distal end, when the inner sheath core and the outer sheath core move axially towards each other, the anchoring member 621 is inserted into the restraint 612, the distal end of the stent body 1 of the covered stent 100 is also radially compressed by the radial compression force transmitted from the bare stent 2 and the barb 3, thereby the operator can timely adjust the shape and position of the covered stent 100.

[0108] It should be noted that the delivery device 600 needs to have the restraint 612 and the anchoring member 621, other structures can adopt existing structures or newly created structures, which are not limited here. Among them, the restraint 612 needs to have relatively high support hardness, for example, it is a steel sleeve with an opening at the proximal end.

[0109] The delivery system 1000 of the present application can not only ensure that the released covered stent 100 is stably anchored and has good adhesion, but also can facilitate the operator to adaptively adjust the shape and / or position of the covered stent 100 according to the needs during the operation through the cooperation of the restraint 612, the anchoring member 621 and the bare stent 2 and the barb 3 of the covered stent 100, while avoiding the formation of a new aneurysm or artery dissection at the distal end of the covered stent 100, thereby reducing the operation risk and the requirement for the operator's medical skills and improving the success rate of the operation.

[0110] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A covered stent, characterized by, The covered stent comprises a stent body, a bare stent arranged at the distal end of the stent body, and a barb connected with the bare stent, the stent body comprises a first wave ring, the barb is connected with the first wave ring, the free end of the barb extends towards a direction away from the bare stent and gradually deviates from the surface of the stent body, so that the barb is at least partially radially stacked on the outer circumferential side of the stent body; the bare stent is radially constrained, the bare stent pulls the barb connected therewith, the pulled barb extrudes the stent body radially stacked thereon inward, so that the stent body is radially compressed, and the barb and the wave rod of the first wave ring are at least partially radially stacked opposite to each other; the bare stent is radially constrained, the bare stent pulls the barb connected therewith, the pulled barb extrudes the wave rod radially stacked opposite thereto inward, and the wave rod drives the stent body to be radially compressed; the stent body comprises a main covering film, the first wave ring is connected to the distal end of the main covering film, the covered stent further comprises a blocking film wrapped on the outer circumferential side of the connection between the barb, the bare stent and the first wave ring, and the blocking film is connected with the main covering film, and the free end of the barb penetrates out from between the two covering films.

2. The stent graft of claim 1, wherein, The barb comprises a first barb and a second barb, the distal ends of the first barb and the second barb are close to each other and connected with the bare stent at the same time, the free ends of the first barb and the second barb extend towards a direction away from the bare stent and gradually deviate from the surface of the stent body in a manner that the two gradually move away from each other, the barb is connected with the wave crest of the first wave ring, and the first barb and the second barb are respectively radially stacked opposite to at least part of the wave rod located on both sides of the wave crest.

3. The stent graft of claim 1, wherein, The extension length of the barb is between 1mm and 10mm; and / or the extension length of the barb is between 0.6 and 0.8 times the wave height of the first wave ring; and / or the included angle of the barb deviating from the surface of the stent body ranges from 15° to 45°.

4. The stent graft of claim 1, wherein, A through hole is arranged at the connection between the barb and the bare stent.

5. The stent graft of claim 1, wherein, The bare stent comprises a plurality of V-shaped wave frames arranged in sequence and spaced apart in the circumferential direction, each adjacent two V-shaped wave frames are connected by an arc-shaped hooking part; the tip of the V-shaped wave frame is at the proximal wave valley and connected with the barb, and the arc-shaped hooking part is at the distal wave crest.

6. The stent graft of claim 1, wherein, The barb and the bare stent are integrally formed.

7. The stent graft of any one of claims 1 to 6, wherein, The first wave ring comprises a plurality of W-shaped wave frames connected in sequence and end to end in the circumferential direction, each W-shaped wave frame has a first wave crest and a first wave valley symmetrically arranged on both sides of the first wave crest, the first wave ring comprises a plurality of first wave crests, a plurality of first wave valleys, and a plurality of second wave crests formed by connecting each two W-shaped wave frames, and the wave angle of the first wave crest is smaller than the wave angle of the second wave crest.

8. The stent graft of claim 7, wherein, The wave angle of the second wave crest is 1 to 3 times the wave angle of the first wave crest.

9. The stent graft of claim 7, wherein, In the case that the barb comprises a first barb and a second barb, the first barb, the second barb and the bare stent are all connected with the first peak of the first wave, the first barb and the second barb are respectively opposite to at least part of the radial layer of the wave rod on both sides of the first peak; and / or, In the case that the bare stent comprises a plurality of V-shaped wave frames arranged in sequence in the circumferential direction, the second peak of the first wave is located between two adjacent V-shaped wave frames of the bare stent, so that the second peak is opposite to the arc-shaped hooking part at the distal peak.

10. The stent graft of claim 7, wherein, The stent body further comprises a second wave frame located on the proximal side of the first wave frame, the second wave frame is connected with the first wave frame through the main covering film, one peak of the second wave frame is opposite to one second peak of the first wave frame, and one valley of the second wave frame is opposite to one W-shaped wave frame of the first wave frame.

11. The stent graft of claim 10, wherein, The second wave frame and the first wave frame are arranged axially spaced or partially axially inserted; wherein, when arranged spaced, the spacing distance between the second wave frame and the first wave frame is between 0mm and 4mm; when partially axially inserted, the insertion height of the second wave frame and the first wave frame is less than or equal to half of the wave height of the first wave frame.

12. The stent graft of claim 1, wherein, The stent body comprises a main body segment located on the distal side, and a long branch and a short branch connected in parallel on the proximal side of the main body segment, the branch lumen of the long branch and the short branch is communicated with the main lumen of the main body segment, and the radial support force of the short branch is greater than that of the long branch in parallel.

13. A delivery system characterized by, The delivery system comprises the covered stent of any one of claims 1-12 and a delivery device for loading and releasing the covered stent, the delivery device comprises a sheath core and a sheath tube sleeved outside the sheath core, the bare stent at the distal end of the covered stent can be hooked on the anchor at the distal end of the sheath core; before the bare stent is separated from the anchor, the bare stent can be constrained by the constraint at the distal end of the sheath core to drive the stent body of the covered stent to be radially compressed.

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