CN113081387B - Covered stent, covered stent conveying system and covered stent loading method - Google Patents

Abstract

The invention discloses a tectorial membrane bracket, which comprises a main body bracket and a skirt bracket, wherein the skirt bracket is sleeved on the outer surface of the main body bracket and is close to the proximal end of the main body bracket, the distal end of the skirt bracket is connected with the outer surface of the main body bracket, the main body bracket comprises a plurality of first supporting bodies and a first tectorial membrane connected with the first supporting bodies, the skirt bracket comprises a plurality of second supporting bodies and a second tectorial membrane connected with the second supporting bodies, the first supporting bodies and the second supporting bodies both comprise a plurality of wave crests, the proximal end of the first supporting body closest to the proximal end of the main body bracket comprises a first exposed part, the proximal end of the second supporting body closest to the proximal end of the skirt bracket comprises a second exposed part, and the first exposed part and the second exposed part both comprise a plurality of exposed wave crests.

Description

Stent graft, stent graft delivery system and loading method of stent graft

Technical field

The invention belongs to the field of medical devices, and specifically relates to a stent graft, a stent graft delivery system and a loading method of the stent graft.

Background technique

This section provides merely background information related to the present disclosure and is not necessarily prior art.

Various pathological changes in the human aorta, such as inflammation and ulcers, can cause damage to the intima or wall of the aorta. Under the combined action of the impact of blood flow, aortic aneurysm or aortic dissection can easily occur. For aortic dissection and other related diseases, the current treatment methods are mainly surgical treatment and interventional treatment. Traditional surgical treatment is surgery. After establishing extracorporeal blood circulation, diseased blood vessels such as aortic dissection are removed, and then artificial blood vessels are used to connect the blood vessels to achieve normal circulation of arterial blood. As traditional surgical treatment has problems such as high risks, greater trauma to people, and long postoperative recovery time, interventional treatment methods are increasingly favored by doctors and patients.

With the continuous development of interventional technology, the advantages of using covered stents to treat aortic aneurysms and arterial dissections have become increasingly prominent. For a stent graft that needs to be implanted into the thoracic aorta, the process of using the stent graft is as follows: first compress the stent into the sheath of the stent delivery device, usually puncture the blood vessel at the femoral artery or iliac artery, and use a guidewire to establish the graft. track, the transporter is established through the iliac artery-abdominal aorta-thoracic aorta-aortic arch-ascending aorta. When the delivery sheath of the pre-installed stent reaches the appropriate lesion position, it is withdrawn through the external control mechanism. Sheath, releasing stent.

In particular, when choosing the chimney parallel stent treatment plan (that is, the branch stent is implanted outside the main stent in parallel with the main stent), at least two stents need to be implanted in the aortic arch to isolate the breach and achieve the purpose of minimally invasive treatment. This requires at least two punctures on the human body surface, which causes great trauma to the person, slows recovery, and increases surgical complications.

Contents of the invention

In view of the above problems, the purpose of the present invention is to at least solve the problem of needing to puncture multiple puncture holes on the human body surface during the chimney parallel stent treatment plan. This purpose is achieved through the following technical solutions:

A covered stent includes a main body stent and a skirt stent. The skirt stent is sleeved on the outer surface of the main body stent and close to the proximal end of the main body stent. The distal end of the skirt stent is connected to the The outer surfaces of the main body bracket are connected, the main body bracket includes a plurality of first support bodies and a first covering film connecting the plurality of first support bodies, the skirt bracket includes a plurality of second support bodies and a first covering film connecting the plurality of first support bodies. The second coating of a plurality of second support bodies, the first support body and the second support body each include a plurality of wave crests, and the proximal end of the first support body closest to the proximal end of the main body stent includes A first exposed portion, the proximal end of the second support body closest to the proximal end of the skirt bracket includes a second exposed portion, both the first exposed portion and the second exposed portion include a plurality of exposed crests .

In one embodiment, the main body stent includes a first stent section, a second stent section, and a connecting section connecting the distal end of the first stent section and the proximal end of the second stent section. The outer diameter is smaller than the outer diameter of the second bracket section, and the distal end of the skirt bracket is connected to the outer surface of the first bracket section.

In one embodiment, the proximal end portion of the first covering covers the distal end portion of the first support body closest to the proximal end of the main body stent.

In one embodiment, both the first support body and the second support body include screw rods, and the diameter of the screw rod constituting the second support body is at least partially smaller than that of the screw rod constituting the first support body. wire diameter.

A stent graft delivery system includes a transporter and any of the above stent grafts. The transporter is used to transport the stent graft. The transporter includes a sheath core and an anchoring part. When the stent graft is When the stent graft is loaded in the transporter, the first exposed part is connected to the anchoring part, and the proximal end of the stent graft is closer to the transporter than the distal end of the stent graft. near end.

In one embodiment, the anchoring part includes a fixing part and an anchoring part, the fixing part is fixed on the sheath core, the anchoring part protrudes from the outer surface of the fixing part, and the anchoring part The thickness of the stator gradually decreases from the proximal end to the distal end and/or the width of the anchoring member gradually decreases from the proximal end to the distal end.

In one embodiment, the delivery device further includes a protruding point structure disposed on the sheath core and protruding from the outer surface of the sheath core, and the protruding point structure is closer to the delivery device than the anchoring portion. the far end.

A loading method for a stent graft includes the above-mentioned delivery system, the delivery device further includes a sheath, and the loading method for the sheath includes the following steps:

Use a pull wire to pass through the multiple exposed wave crests on the first exposed part in sequence along the circumferential direction of the covered stent, and hang the exposed wave crests on the first exposed part on the anchoring part, so that the covered stent The membrane stent moves toward the proximal end of the conveyor, and the proximal end of the main body stent is received into the conveyor.

In one embodiment, the loading method includes the following steps:

Use a pull wire to pass through the second exposed portion along the circumferential direction of the stent graft and move toward the proximal end of the conveyor, so that the proximal end of the skirt stent is retracted into the conveyor.

In one embodiment, when using a pull wire to thread around the first exposed part and the second exposed part, two pull wires are used to thread around the first exposed part and the second exposed part respectively.

In one embodiment, when using a pull wire to thread around the first exposed part and the second exposed part, a pull wire is used to thread around the first exposed part, and one end of the pull wire is first circumferentially threaded around the first exposed part. half a week, then pass to the second exposed part, and go around the entire circumference along the circumferential direction of the second exposed part, and then go through the first exposed part and go around the other half of the first exposed part.

In one embodiment, the outer surface of the sheath core of the delivery device is provided with a protruding point structure, and the protruding point structure is closer to the distal end of the delivery device than the anchoring portion. When the inner surface of the main body stent When in contact with the bump structure, the pull wire is pulled out.

The advantages of the present invention are:

The coated stent provided by the present invention is provided with exposed parts at the proximal ends of the main body stent and the skirt stent, so that reverse assembly can be achieved during assembly of the stent, and the exposed part and the coated part form a small step, and the compression cross-section size of the exposed part is larger than that of the coated stent. The compression cross-section size of the proximal end of the membrane is smaller, which is more convenient for the stent graft to be assembled into the sheath. The transporter of the stent graft delivery system provided by the present invention is provided with an anchoring portion at the proximal end of the sheath core, and the transporter can load the stent on it in a reverse assembly manner. The loading method of the stent graft provided by the present invention uses the pull wire to match the exposed part of the stent to realize the reverse assembly of the stent graft. When the conveyor of the embodiment of the present invention is used to implant the chimney parallel stent, since the stent on it is Assembled in reverse, the transporter can deliver the branch stent into the branch vessel through the puncture hole created when the main stent is implanted, thereby reducing the damage to the patient from the puncture hole and also reducing the impact of branch vessel stent implantation on the aorta. Impact on the safety and reliability of the stent.

Description of drawings

The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the invention. Also throughout the drawings, the same reference characters are used to designate the same components.

In the attached picture:

Figure 1 is a schematic structural diagram of a conveyor according to an embodiment of the present invention;

Figure 2 is a schematic diagram of an anchoring part according to an embodiment of the present invention;

Figure 3 is a schematic diagram of another anchoring part according to an embodiment of the present invention;

Figure 4 is a schematic diagram of a bracket according to an embodiment of the present invention;

Figures 5a to 5c are schematic diagrams of the stent assembly process in the stent delivery system according to an embodiment of the present invention;

Figure 6 is a schematic diagram of the stent delivery system according to an embodiment of the present invention when it is applied to a chimney parallel stent treatment plan;

Figure 7 is a schematic view of the stent in the structure shown in Figure 6 after deployment.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a thorough understanding of the disclosure, and to fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprises", "includes", "contains" and "having" are inclusive and thus indicate the presence of stated features, steps, operations, elements and/or parts but do not exclude the presence or addition of one or Various other features, steps, operations, elements, components, and/or combinations thereof. The method steps, procedures, and operations described herein are not to be construed as requiring that they be performed in the particular order described or illustrated, unless an order of performance is expressly indicated. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections shall not be referred to as restricted by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. These relative terms, such as "inner", "outer", "inner" ”, “outside”, “below”, “below”, “above”, “above”, etc. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "beneath" the other elements or features. Features above". Thus, the example term "below" may include an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, when describing the implant, the orientation can be defined according to the direction of blood flow, and the blood flow can be defined as flowing from the proximal end to the distal end. For example, for a stent, the present invention defines the end where the blood flows in as the "proximal end" and the end where the blood flows out. is the "distal end"; and for devices that require direct operation by the operator, such as conveyors, the present invention defines the end close to the operator as the "proximal end" and the end far away from the operator as the "distal end".

As shown in Figure 1, an embodiment of the first aspect of the present invention provides a conveyor 100 for loading and conveying a stent graft 200. Specifically, the delivery device 100 includes a sheath tube 10 , a sheath core 20 that is axially movably inserted into the sheath tube 10 , and an anchoring portion 40 provided at the distal end of the sheath core 20 .

The stent delivery device 100 according to the embodiment of the present invention is provided with an anchoring portion 40 at the proximal end of the sheath core 20, and the delivery device 100 can cooperate with a pull wire to load the stent graft 200 on it in a reverse assembly manner. Specifically, the pull wire 30 is movably inserted into the sheath 10. The pull wire 30 is used to circumferentially wrap around the proximal opening of the stent graft 200. The free end of the pull wire 30 passes through the proximal end of the sheath 10. When the pulling wire 30 moves proximally relative to the sheath tube 10 , the proximal opening of the stent graft 200 shrinks, so that the proximal end of the stent graft 200 is fixed on the sheath core 20 through the anchoring part 40 . More specifically, the stent graft 200 can be placed on the sheath core 20 , and then the pull wire 30 is threaded around the proximal opening of the stent graft 200 and the free end of the pull wire 30 is passed out from the proximal end of the sheath tube 10 , and then The proximal opening of the stent graft 200 is contracted using the pulling wire 30 , and then the proximal end of the stent graft 200 is loaded into the sheath 10 , so that the proximal end of the stent graft 200 is fixed to the sheath core 20 through the anchoring part 40 , and then the sheath 10 is directed toward the distal direction, and the stent 200 is gradually contracted and stored in the sheath 10 . Thus, the stent graft 200 is assembled on the transporter 100 in reverse order (the proximal end of the stent 200 is close to the proximal end of the transporter 100, while the distal end of the stent graft 200 is close to the distal end of the transporter 100). When the transporter 100 according to the embodiment of the present invention is used to implant a chimney-parallel stent, since the covered stent 200 on it is assembled in reverse, the transporter 100 can branch through the puncture hole created when the main stent is implanted. The covered stent 200 is delivered to the position of the branch blood vessel (described in detail later), thereby reducing damage to the patient from the puncture port.

In some embodiments of the present invention, the anchoring part 40 includes a fixing part 41 and an anchoring part 42. The fixing part 41 is fixed on the sheath core 20 and the anchoring part 42 protrudes from the outer surface of the fixing part 41. The anchoring part 42 Used to anchor the proximal end of the stent 200.

The fixing member 41 may be a hollow annular structure, and may be fixed on the sheath core 20 by bonding, welding or injection molding.

In a specific embodiment, as shown in FIG. 2 , the anchor 42 is a wedge-shaped structure with a proximal thickness greater than a distal thickness, wherein the thickness of the anchor 42 refers to the thickness of the anchor 42 in the sheath core 20 Radial dimensions. In this embodiment, an inclined area is formed between the proximal end and the distal end of the anchor 42 , which can reduce the overall volume of the anchor 42 and make it easier for the covered portion of the stent 200 to enter the sheath 10 . In addition, when the stent graft is loaded, the exposed crest hook hangs on the proximal end of the anchor, and the support body and coating close to the crest on the stent graft will accumulate at the distal end of the anchor when compressed. The thick bottom of the distal end is small, which can reduce the size of the compressed stent graft as a whole, and can reduce the size of the outer sheath to a certain extent. Moreover, the thickness of the distal end of the anchor is small and flat, which will not resist the compression of the stent and will not break the coating.

In another specific embodiment, as shown in FIG. 3 , the anchoring member 42 has a triangular structure, in which the size of the proximal end of the anchoring member 42 in the circumferential direction is larger than the size of the distal end in the circumferential direction, that is, the anchoring member 42 has a triangular structure. The proximal end of the anchor member 42 is the bottom edge of the triangular structure, and the distal end of the anchor member 42 is the apex angle β of the triangular structure. This can reduce the overall volume of the anchor member 42 and make it easier for the covered part of the stent 200 to enter the sheath. tube 10. Preferably, the range of the vertex angle β may be 30°≤β≤60°. It will be appreciated that in other embodiments, both the thickness and width of the anchor may gradually decrease from proximal to distal end.

On the same perimeter of the fixing part 41, the number of anchoring parts 42 may be between 1 and 5.

In some embodiments of the present invention, the delivery device 100 further includes a protruding point structure 50 disposed on the sheath core 20 and protruding from the outer surface of the sheath core 20 , and the protruding point structure 50 is closer to the proximal portion of the delivery device than the anchoring portion. end. When the stent 200 shrinks to a certain extent, the bump structure 50 can contact the inner wall of the stent 200, thereby increasing the friction between the stent 200 and the sheath core 20. In addition, when the stent 200 is released, the stent 200 can be prevented from shortening.

In some embodiments of the present invention, the delivery device 100 further includes a push rod 60 connected to the proximal end of the sheath core 20 . The distal end of the push rod 60 can resist the proximal end of the stent 200 , thereby allowing the stent 200 to be received in the sheath tube. 10 or when the stent 200 is released from the sheath 10, it will not move proximally.

In some embodiments of the present invention, the delivery device 100 further includes a guide head 70 connected to the distal end of the sheath core 20 . The guide head 70 is used to guide the delivery device 100 into the blood vessel along the guide wire 300 . In order to reduce the scratching of blood vessels by the guide head 70, the guide head 70 can be configured in a conical shape.

In some embodiments of the present invention, when loading the stent, a guide sheath 80 is also used. The guide sheath 80 is sleeved on the distal end of the sheath 10, and both ends of the guide sheath 80 are in the form of a gradually expanding trumpet-shaped structure. During the process of loading the stent 200 on the delivery device 100, the proximal opening of the stent 200 can be compressed once by the guide sheath 80 before entering the sheath 10, and then further contracted by the action of the pull wire 30 and then enter the sheath 10.

In some embodiments of the present invention, the pulling wire 30 can be suture silk or nylon thread commonly used in medical devices. The material has a certain strength but will not damage the support structure and coating structure of the stent 200. In some other embodiments, the pull wire 30 may also be made of a material with a certain stiffness, so as to ensure that the pull wire 30 will not detach or break from the sheath tube 10 and the sheath core 20 . Just make sure that the cable is not easy to break or the material of the cable is not easy to fall off. Further, the wire diameter of the pull wire 30 may be between 0.07 mm and 0.1 mm.

The second embodiment of the present invention provides a stent graft delivery system, which includes a stent graft 200 and the transporter 100 in any of the above embodiments.

The stent graft delivery system according to the embodiment of the present invention has the conveyor 100 according to the embodiment of the first aspect of the present invention. Therefore, the stent graft delivery system according to the embodiment of the present invention has all the technical effects of the above-mentioned conveyor 100.

Specifically, as shown in FIG. 4 , the stent graft 200 includes a main body stent 210 and a skirt stent 220 . The skirt stent 220 is sleeved on the outer surface of the main body stent 210 close to the proximal end of the main body stent. The distal end of the skirt bracket 220 is connected to the outer surface of the main body bracket 210, that is, the skirt bracket 220 has an opening toward the proximal end. The main body bracket 210 includes a plurality of first support bodies 211 and a first covering film 212 connecting the plurality of first support bodies 211. The skirt bracket 220 includes a plurality of second support bodies 221 and a second covering film 222 connecting the plurality of second support bodies 221 . The proximal end of the main body bracket 210 forms a first proximal opening, and the distal end of the main body bracket 210 forms a first distal opening. The proximal end of the skirt bracket 220 is formed with a second proximal opening. The proximal end of a first support body 211 closest to the proximal end of the main body stent 210 has a first exposed portion that is not covered by the first covering film 212, and the proximal end of a second support body 221 closest to the proximal end of the skirt stent 220 There is a second exposed portion not covered by the second coating 222 .

In this embodiment, the stent graft 200 is a double-layered stent including a main body stent 210 and a skirt stent 220. The main body stent 210 has a larger radial force and can resist the contraction of blood vessels and maintain smooth blood flow. When the stent 200 is used to supply blood to a branch vessel, the skirt stent 220 can be extruded and deformed to eliminate the gap between the implanted aortic stent and the main body stent and the blood vessel wall. In addition, a first exposed portion and a second exposed portion are respectively formed at the first proximal opening and the second proximal opening. One of the purposes is to facilitate the threading of the pull wire 30, and the other is to form a gap between the exposed portion and the starting position of the film. The small step makes it easier for the coated part to shrink into the sheath 10. Third, it is easy to self-expand and expand when the coated stent 200 is released, reducing the constraint between the coating on the skirt stent and the coating on the main stent.

Both the first support body 211 and the second support body 221 include a plurality of wave rings arranged along the length direction of the bracket. The wave ring structure is W-shaped, and the wave ring structure has multiple turning vertices. The present invention combines a single wave ring with The apex closer to the proximal end of the stent is called the "crest" and the apex closer to the distal end of the stent is called the "trough." Correspondingly, the first exposed part is a part of a wave ring at the most proximal end of the first support body 211, the second exposed part is a part of a wave ring at the most proximal end of the second support body 221, and the first Both the exposed portion and the second exposed portion include a plurality of exposed crests. That is, the coating only covers part of the most proximal wave circle, leaving the wave crest exposed. Thus, a small step is formed between the exposed crest and the proximal end of the coating.

The main body stent 210 includes a first stent section 2101, a second stent section 2102, and a connecting section 2103 connecting the distal end of the first stent section 2101 and the proximal end of the second stent section 2102, wherein the first stent section 2101 and the second stent section The segments 2102 are all straight tubular structures, and the outer diameter of the first stent segment 2101 is smaller than the outer diameter of the second stent segment 2102 . The outer diameter of the connecting section 2103 gradually increases from the proximal end to the distal end, and the outer diameter of the proximal end of the connecting section 2103 is equal to the outer diameter of the first stent section 2101, and the outer diameter of the distal end of the connecting section 2103 is equal to the outer diameter of the second stent section 2102. The diameters are equal, so that the outer surface of the connecting section 2103 has an inclination angle α relative to the length direction of the main bracket 210. In order to avoid the outer diameter difference between the first bracket section 2101 and the second bracket section 2102 being too large, the inclination angle α range is preferably 15°. ≤α≤30°, and the axial length of the connecting section 2103 is preferably in the range of 5 mm to 10 mm. Setting the inclination angle can increase the anchoring force between the stent graft 200 and the blood vessel and prevent the stent from being displaced after release. In order to ensure that the second stent segment 2102 has a certain anchoring force after being implanted in the branch, the length of the second stent segment 2102 is preferably not less than 15 mm. The length of the first bracket section 2101 can be selected according to actual needs and is not limited by the present invention. It should be understood that the present invention controls the outer diameter difference between the first stent section and the second stent section to not be too large in order to ensure that the opening of the first stent section does not become too small, thereby affecting the amount of blood flowing into the branch blood vessel.

In addition, the outer diameter of the first bracket segment of the present invention is smaller than the outer diameter of the second bracket segment. When the support members of the first bracket segment and the second bracket segment have the same number of peaks and troughs and the wires that constitute the screw rod of the support member When the diameters are the same, the radial deformation capacity of the first bracket section is greater than the radial deformation capacity of the second bracket section. When the covered stent of the present invention is implanted close to the aortic stent, the proximal opening of the first stent segment will not be overly squeezed by the aortic stent, thus affecting the blood inflow into the branch. It can be understood that when the radial deformation capacity of the first stent segment is large, the difficulty of loading the stent will also increase. Therefore, the present invention also provides a first exposed portion at the proximal end of the first stent segment to A small step is formed between the exposed part and the proximal end of the coating, so that when the stent graft is loaded into the sheath, the exposed part with a smaller compressed cross-section first enters the sheath, and then the covered part that is slightly larger than the exposed part enters the sheath. Partially re-enters the sheath to reduce the difficulty of loading the stent graft.

When the stent graft is compressed and reproduced, the skirt stent and the main stent will have a partial overlap area. If the wire diameter of the screw rod constituting the first support body is the same as the wire diameter of the screw rod constituting the second support body, the stent graft will be compressed. Then, the cross-sectional size of this overlapped area will be larger than the cross-sectional size of the rest of the stent graft. In order to reduce the impact of the overlapping area on the overall delivery size of the stent graft, in other embodiments, the wire diameter of the support body in this area can be appropriately reduced, so that the compressed cross-sectional size of the overlapping area is at least no larger than the second stent segment. compression section size. That is to say, the wire diameter of the screw rod constituting the second support body on the skirt bracket is at least smaller than the wire diameter of part of the screw rod of the first support body. More preferably, the third part of the area on the main body bracket that overlaps the skirt bracket The wire diameter of the screw rod of one support body is smaller than the wire diameter of the screw rod of the remaining first support body on the main frame.

In some embodiments of the present invention, the distal end of the first covering 212 matches the shape of the distal end of the main body support 210 , that is to say, the wave rod of the most distal wave ring of the first support body 211 is completely covered by the second wave ring. It is covered by a coating 212, but there is no coating between two adjacent troughs. This arrangement can increase the friction between the stent and the transporter during assembly, and can also reduce stimulation to the blood vessel wall.

The skirt bracket 220 and the main body bracket 210 may be connected by sewing or welding.

In order to ensure that the covered stent 200 will not block the end blood flow of the implanted aortic stent after implantation, the distance between the proximal end of the skirt stent 220 and the proximal end of the main body stent 210 is preferably 10 mm to 15 mm.

Both the first support body 211 and the second support body 221 can be made of various biocompatible materials, including known materials used in implanted medical devices or combinations of various materials, such as 316L stainless steel, cobalt-chromium-nickel-titanium - Magnesium-iron alloy, nickel-titanium-tantalum alloy, etc., or other biocompatible metal materials. The first support body 211 and the second support body 221 can be formed by winding or cutting metal wires, or the connection between the support structures can be achieved by sewing, winding, weaving, cutting or coating. The first covering film 212 and the second covering film 222 can be an ePTFE film or a PET film, and can cover the first supporting body 211 and the second supporting body 221 by sewing or heat melting.

When a stent with a multi-layer structure similar to the stent graft 200 of the present invention is covered with double-layer PTFE or ePTFE, the coatings between the layers are prone to adhesion, which affects the expansion of the stent after compression. In the present invention, the proximal end of the skirt stent 220 is set into a semi-naked structure (that is, a second exposed portion is formed). Since the semi-bare wave ring will not adhere to the first covering of the main body stent 210, when the covered stent 200 is deployed, , the proximal edge self-expands, thereby driving other covered parts to expand, preventing the outer skirt stent 220 from failing to expand.

In some embodiments of the present invention, when the bracket is loaded, the pull wire 30 includes a first pull wire 301 for circumferentially passing through the first exposed part and a second pull wire for circumferentially passing through the second exposed part. 302. In other embodiments, there may be only one pull wire 30 , and the pull wire may pass through the first exposed part and the second exposed part at the same time. When the pull wire moves toward the proximal direction, the first proximal end may be opened at the same time. and constriction of the second proximal opening.

A third embodiment of the present invention provides a method for loading a luminal stent, which method is implemented based on the stent delivery system in any of the above embodiments. As shown in Figure 5a to Figure 5c, specifically, the loading method includes:

S101: Set the guiding sheath 80 on the distal end of the sheath tube 10, and set the stent graft 200 on the sheath core 20;

S102: After the pull wire 30 is threaded around the first exposed part of the stent graft 200, the free end of the pull wire 30 is passed out from the proximal end of the sheath 10;

S103: Hang the first exposed part on the protruding part 42 of the anchoring part 40, start the pull wire 30, and shrink the first proximal opening of the stent graft 200;

S104: Control the sheath tube 10 to move toward the distal end of the conveyor, and pull the pull wire 30 to gradually store the proximal end of the main body stent 210 in the sheath tube 10;

S105: After the pull wire 30 is threaded around the second exposed part of the stent graft 200, the free end of the pull wire 30 is passed out from the proximal end of the sheath 10;

S106: Activate the pull wire 30 to shrink the second proximal opening of the stent graft 200;

S107: Control the sheath tube 10 to move toward the distal end of the conveyor, and pull the pull wire 30 to gradually store the proximal end of the skirt stent 220 in the sheath tube 10;

S108: Continue to control the sheath tube 10 to move toward the distal end of the conveyor until all the stent grafts 200 are stored in the sheath tube 10.

Before pulling the proximal end of the main body stent 210 into the sheath 10 , hang the first exposed portion on the protruding portion 42 of the anchoring portion 40 , thereby anchoring the stent graft 200 . When the covered part of the stent graft 200 comes into contact with a part of the bump structure 50, the pull wire 30 is pulled out in order to anchor the proximal part of the main body stent 210. Pulling out the pull wire 30 does not affect subsequent assembly. When the pull wire is passed through the sheath tube, since the pull wire itself has a certain hardness, it can be easily passed through the sheath tube. It is understandable that other tools can also be used, which will not be described in detail in the present invention.

In addition, after the proximal end of the skirt stent 220 is pulled into the sheath 10, when the skirt stent 220 completely enters the sheath 10, the pull wire 30 is pulled out. Pulling out the pull wire 30 does not affect subsequent assembly.

In some other embodiments, steps S102 to S108 can also be replaced with:

S102′: After the pull wire 30 is threaded around the first exposed part and the second exposed part of the stent graft 200, the free end of the pull wire 30 is passed out from the proximal end of the sheath 10;

S103′: Activate the pull wire 30 to shrink the first proximal opening and the second proximal opening of the stent graft 200;

S104' controls the sheath tube 10 to move toward the distal end of the conveyor, and pulls the pull wire 30 to gradually store the stent graft 200 in the sheath tube from the proximal end to the distal end.

In this embodiment, the half turns of the first exposed part can be put on sequentially with the pull wire 30, and a free end of the pull wire 30 can be passed through the second exposed part counterclockwise, and the free end can be pulled back to the first exposed part to continue. The remaining half turn is threaded, and then the free end is led out from the proximal end of the sheath 10 . By pulling the pulling wire 30 in this embodiment, the first proximal opening and the second proximal opening of the stent graft 200 can be contracted simultaneously.

The loading method provided by the present invention uses a pull wire to tighten the proximal end of the stent graft. Even if the radial support force of the proximal end of the stent graft is relatively large, the stent graft can be quickly loaded into the sheath. In addition, when used with the guide sheath, the guide sheath can also pre-compress and disperse the force on the sheath to a certain extent.

After loading according to the loading method of the present invention, the proximal end of the stent graft is close to the proximal end of the conveyor, and the distal end of the stent graft is close to the distal end of the conveyor. Therefore, when the covered stent is released from the delivery device and implanted into the body, it can be implanted in the reverse direction.

The effects of the present invention are illustrated below in conjunction with specific embodiments:

As shown in Figure 6, the chimney parallel stent implantation operation of the delivery device is described as follows:

Blood vessel 805 is an aortic dissection vessel and is treated with an inverted chimney parallel stent. The stent graft 200 is assembled in the transporter 10. After the implantation of the aortic stent 803 is completed through the puncture port 804, the transporter 10 loaded with the stent graft 200 enters through the puncture port 804, and is guided by the guide wire 300 to enter if reconstruction is required. The location of the branch blood vessel 802. The location of the puncture port 804 is also the location of the entrance of the large stent 803, which can reduce the damage caused by the puncture port. In addition, compared with the proximal end of the aortic stent 803, the blood pressure at the distal end is smaller. When a branch vessel stent (ie, the stent graft of the present invention) is implanted at the distal end, the impact caused by blood flow can be reduced. There is a risk of stent displacement, and at this time, the adhesion between the proximal end of the aortic stent 803 and the vascular stent is not affected by the implantation of the branch vessel stent, and the safety and reliability of the stent are higher. That is to say, the present invention After implantation of the covered stent, it has less impact on the aortic stent.

As shown in FIG. 7 , the stent graft 200 is released from the first distal opening, is first anchored to the branch vessel 802 , and then is released to the first proximal opening of the stent graft 200 . As shown in FIG. 7 , the stent graft 200 is released from the first distal opening. The gap caused by the extrusion between the bracket 200 and the large bracket 803 is blocked by the skirt bracket 220, effectively preventing internal leakage.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention. All substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (11)

1. A stent graft comprising a main body stent and a skirt stent, wherein the skirt stent is sleeved on the outer surface of the main body stent and is close to the proximal end of the main body stent, the distal end of the skirt stent is connected with the outer surface of the main body stent, the main body stent comprises a plurality of first supporting bodies and a first coating film connected with the first supporting bodies, the skirt stent comprises a plurality of second supporting bodies and a second coating film connected with the second supporting bodies, and the first supporting bodies and the second supporting bodies comprise a plurality of wave crests, and the stent graft is characterized in that the proximal end of the first supporting body closest to the proximal end of the main body stent comprises a first exposed part, the proximal end of the second supporting body closest to the proximal end of the skirt stent comprises a second exposed part, and the first exposed part and the second exposed part comprise a plurality of exposed wave crests; the first exposed part and the second exposed part enable reverse assembly to be realized when the bracket is assembled.

2. The stent graft of claim 1, wherein said main body stent comprises a first stent segment, a second stent segment, and a connecting segment connecting a distal end of said first stent segment with a proximal end of said second stent segment, said first stent segment having an outer diameter less than an outer diameter of said second stent segment, said distal end of said skirt stent being connected to an outer surface of said first stent segment.

3. The covered stent of claim 1, wherein the proximal portion of the first cover covers the distal portion of the first support body nearest the proximal end of the main body stent.

4. The stent graft of claim 1, wherein said first support and said second support each comprise a lead screw, the lead screw comprising said second support having a lead diameter at least partially smaller than the lead screw comprising said first support.

5. A stent graft delivery system comprising a delivery device and the stent graft of any one of claims 1-4, the delivery device being configured to deliver the stent graft, the delivery device comprising a sheath core and an anchor portion, the first exposed portion being connected to the anchor portion when the stent graft is loaded in the delivery device, and a proximal end of the stent graft being closer to a proximal end of the delivery device than a distal end of the stent graft.

6. The stent graft delivery system of claim 5, wherein said anchor comprises a fastener and an anchor, said fastener being secured to said sheath core, said anchor protruding from an outer surface of said fastener, and wherein a thickness of said anchor decreases gradually from proximal to distal and/or a width of said anchor decreases gradually from proximal to distal.

7. The stent graft delivery system of claim 6, wherein said delivery device further comprises a bump structure disposed on said sheath core and protruding from an outer surface of said sheath core, said bump structure being closer to a distal end of said delivery device than said anchor.

8. A method of loading a stent graft comprising the delivery system of claim 5, the delivery further comprising a sheath, the method comprising the steps of:

sequentially penetrating through a plurality of exposed wave crests on the first exposed part along the circumferential direction of the covered stent by using a pull wire, hanging the exposed wave crests on the first exposed part on the anchoring part, enabling the covered stent to move towards the proximal end of the sheath, and taking the proximal end of the main body stent into the sheath; and a pull wire passes through the second exposed part along the circumferential direction of the covered stent and moves towards the proximal end of the sheath, so that the proximal end of the skirt stent is retracted into the sheath, and then the sheath is retracted towards the distal direction, so that the stent is gradually retracted and accommodated in the sheath.

9. The loading method of the stent graft of claim 8, wherein when using two pull wires to wind the first exposed portion and the second exposed portion, two pull wires are used to wind the first exposed portion and the second exposed portion, respectively.

10. The loading method of the stent graft of claim 8, wherein when the first exposed portion and the second exposed portion are wound with the pull wire, the pull wire is simultaneously wound with one pull wire, and one end of the pull wire is wound around a half of the first exposed portion in the circumferential direction, then around the second exposed portion, around the entire circumference in the circumferential direction of the second exposed portion, and then around the other half of the first exposed portion in the circumferential direction.

11. The loading method of the stent graft of claim 8, wherein the outer surface of the sheath core of the conveyor is provided with a bump structure, the bump structure being closer to the distal end of the conveyor than the anchoring portion, and the pull wire is pulled out when the inner surface of the main body stent contacts the bump structure.