CN114052981A - Covered stent and covering method - Google Patents

Abstract

The invention discloses a covered stent and a covering method, the covered stent comprises: the stent main body comprises an inflow section, an outflow section and a middle section positioned between the inflow section and the outflow section, wherein blood can flow in from the inflow section and flow out from the outflow section after passing through the middle section; and the coating is arranged at one end, close to the inflow section, of the middle section of the stent body in a surrounding way and corresponds to the proximal end of an aneurysm opening. The tectorial membrane of the tectorial membrane stent provided by the invention can cover the proximal end of an aneurysm opening, prevent or reduce blood in a blood vessel from entering the aneurysm, and improve the healing efficiency of the aneurysm.

Description

Covered stent and covering method

Technical Field

The invention relates to the field of medical instruments, and further relates to a covered stent and a covering method.

Background

Aneurysms are common cardiovascular and cerebrovascular diseases and are extremely lethal once ruptured. Larger aneurysms are more at risk of rupture, and even if the ruptured aneurysm is treated conservatively, the ruptured aneurysm is more at risk of rupture after stabilization, and the aneurysm usually has an acute onset and a short course of disease and is prone to poor prognosis. The causes of aneurysm formation are many, and are related to arteriosclerosis, hypertension, myofibrodysplasia, immune factors, genetic factors and the like, and the pathogenesis of the aneurysm is not completely clear at present. There is no fully unified understanding of the treatment of aneurysms, medical treatment is the basis, and the treatment of aneurysms mainly involves surgical clamping of the aneurysm and interventional intraluminal treatment. The surgical operation has higher risk, larger wound and more complications, and along with the development of interventional technology, the occurrence of the bracket greatly improves the curative effect of interventional therapy on intracranial aneurysm.

The current clinical major stent techniques include stent assisted coil embolization, blood flow guide placement and stent graft placement. The stent-assisted spring ring embolism can change the hemodynamic state of the neck of the aneurysm, change the curvature of the parent artery and play a role of a scaffold for the growth of vascular endothelium. The blood flow guiding device can change the hemodynamic state in the artery to induce thrombosis in the aneurysm. The covered stent can isolate the blood flow in the aneurysm to induce the thrombosis in the aneurysm. However, the prior art vascular stents still have some drawbacks.

In the process of interventional operation of stent-assisted spring coil embolism, the aneurysm cavity needs to be filled by passing through a stent mesh delivery spring coil through a microcatheter, the difficulty of passing through the stent gap by the microcatheter is high, the risk is high due to the fact that vascular tissues are easy to puncture during operation, and the cost is high. There is a risk of delayed occlusion, recurrence, rupture after aneurysm embolization. In the blood flow guiding device implantation, in order to change the blood flow in the artery to induce the thrombosis in the aneurysm, the stent is expected to have high metal coverage rate, and the metal coverage rate of the blood vessel stent refers to the proportion of the metal coverage area in the stent to the total area of the stent. At present, the Pipeline stent with the metal coverage rate of about 35 percent can be selected for interventional therapy clinically. However, a series of problems also exist when the metal coverage of the stent is higher: 1. the higher the coverage, the higher the radial tension, the poorer the compliance; 2. high coverage may obstruct or even block the blood flow of peripheral blood vessels, causing additional harm to the patient; 3. in the case of high coverage, the blood pressure at the proximal end of the aneurysm is high, and the meshes of the stent are easy to rupture and bleed under the continuous scouring of blood flow. If the full-covered stent is adopted, although the blood flow in the aneurysm can be isolated, the full-covered stent has the risk of covering other branch arteries of the blood vessel to block the normal blood flow, and has high profile characteristics, so that the stent is difficult to convey and difficult to reach a lesion part, and the application range is limited.

In view of the above, there is a need to develop a more deliverable and safer endovascular treatment implant for diseased vessels adjacent to important branch vessels in larger aneurysms to avoid delayed occlusion, recurrence, or even rupture of the aneurysm.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a stent graft and a method for grafting a stent graft, in which a stent graft is positioned at one end of a stent main body, which is close to an inflow section, of a middle section, and which can close the proximal end of an aneurysm opening, prevent or reduce the flow of blood in a blood vessel from entering the aneurysm, and facilitate the repair of the aneurysm.

In order to achieve the above object, the present invention provides a stent graft comprising:

the stent main body comprises an inflow section, an outflow section and a middle section positioned between the inflow section and the outflow section, wherein blood can flow in from the inflow section and flow out from the outflow section after passing through the middle section;

and the coating is arranged at one end, close to the inflow section, of the middle section of the stent body in a surrounding way and corresponds to the proximal end of an aneurysm opening.

In some preferred embodiments of the invention, the length of the cover is greater than half the length of the aneurysm opening and less than the length of the aneurysm opening.

In some preferred embodiments of the invention, the stent body is a self-expanding stent.

In some preferred embodiments of the present invention, the stent body is made of a shape memory material.

In some preferred embodiments of the present invention, the covering membrane is attached to the middle section of the stent body by sewing, or by bonding, or by electrospinning.

In some preferred embodiments of the present invention, the cover film is a single-layer film, and is mounted on the inner side or the outer side of the stent main body.

In some preferred embodiments of the present invention, the cover includes an inner cover mounted to an inner wall of the stent body and an outer cover mounted to an outer wall of the stent body.

In some preferred embodiments of the present invention, the material of the inner layer film is a non-degradable polymer which is biologically modified or carries a functional drug; the outer layer film is made of non-degradable high polymer material.

In some preferred embodiments of the present invention, the stent graft further comprises a development marker, and the development marker comprises a stent development marker and a stent graft development marker, wherein the stent development marker is mounted on the stent main body and used for marking the position of the stent main body, and the stent graft development marker is mounted at the joint of the stent graft and the stent main body.

In some preferred embodiments of the present invention, the stent development marker and the stent graft development marker are made of a combination of one or more of gold, platinum, PTW alloy, or PtIr alloy.

According to another aspect of the present invention, the present invention further provides a film coating method comprising:

when the covered stent is in a contraction state, controlling the covered stent to enter a blood vessel with aneurysm, and enabling one end of the middle section of the stent main body, which is close to the inflow section, to correspond to the proximal end of the aneurysm opening;

allowing the stent graft to switch to an expanded state, and distracting a graft located in the middle section of the stent body close to the inflow section by the stent body, so that the graft covers a proximal end of the aneurysm opening.

The covered stent provided by the invention has at least one of the following beneficial effects:

1. the cover film of the covered stent provided by the invention covers one end, close to the inflow section, of the middle section of the stent main body and can cover the proximal end of the aneurysm opening, so that blood in a blood vessel can be further prevented or reduced from flowing into the aneurysm, and the aneurysm healing efficiency is improved.

2. According to the stent graft provided by the invention, the membrane is arranged at one end, close to the inflow section, of the middle section of the stent main body, and the membrane correspondingly covers the proximal end of the aneurysm opening, so that the pressure intensity of the stent main body can be reduced, the fatigue resistance of the whole implant is improved, and the stent main body is prevented from being damaged and the aneurysm is prevented from being broken. And the part of the tectorial membrane can adopt a stent main body with lower metal coverage rate to improve the compliance of the implant.

Drawings

The above features, technical features, advantages and modes of realisation of the present invention will be further described in the following detailed description of preferred embodiments thereof, which is to be read in connection with the accompanying drawings.

FIG. 1 is a perspective view of a stent graft of a preferred embodiment of the present invention;

FIG. 2 is a partial perspective view of a stent graft of a preferred embodiment of the present invention;

FIG. 3 is a schematic view of blood flow in a vessel without a stent implanted therein;

FIG. 4 is a schematic illustration of blood flow after placement of a stent graft of a preferred embodiment of the present invention into a blood vessel;

FIG. 5 is a partial schematic view of a stent graft according to a preferred embodiment of the present invention after placement in a blood vessel;

FIG. 6 is a schematic illustration of a repair procedure for an aneurysm after placement of a stent in a blood vessel;

FIG. 7 is a schematic representation of blood flow in an advanced aneurysm;

fig. 8 is a schematic blood flow diagram of an early stage aneurysm.

The reference numbers illustrate:

1 stent main part, 2 tectorial membranes, 3 development marks, 11 inflow sections, 12 interlude, 13 outflow sections, 31 stent development marks, 32 tectorial membrane development marks, x blood vessel, d aneurysm, z branch's blood vessel.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, only the parts relevant to the invention are schematically shown in the drawings, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

Example 1

Referring to the attached drawings 1-7 in the specification, the invention provides a covered stent, wherein a middle section of a stent main body of the covered stent is covered by a film, and the film is positioned at one end of the middle section close to an inflow section, so that the proximal end part of an opening of a hemangioma communicated with a blood vessel can be blocked during use, and the inflow of blood in an aneurysm area can be further prevented or reduced, thereby being beneficial to healing.

Referring to the attached drawings 1 and 2 of the specification, in particular, the stent graft comprises a stent body 1 and a stent graft 2, wherein the stent body 1 comprises an inflow section 11, an intermediate section 12 and an outflow section 13, the intermediate section 12 is located between the inflow section 11 and the outflow section 13, and when the stent graft is installed in a blood vessel, blood in the blood vessel can enter from the inflow section 11 and flow out from the outflow section 13 after passing through the intermediate section 12. The coating 2 is mounted to the middle section 12 of the stent body 1.

The stent body 1 has a crimped state in which the stent body 1 is contracted and can be loaded with a delivery device to be delivered into a blood vessel containing an aneurysm structure, and an expanded state; after the stent body 1 is delivered to a preset position in a blood vessel, the delivery device is separated from the covered stent, the binding force acting on the stent body 1 disappears, the stent body 1 gradually expands, the volume expands to the expanded state, and the covered stent 2 is expanded.

Further, the coating film 2 is attached to one end of the intermediate section 12 near the inflow section 11. The length of the middle section 12 corresponds to the size of the opening of the aneurysm d communicating with the blood vessel x, and the length of the coating 2 is smaller than the length of the middle section 12.

Specifically, when the stent graft is installed in a blood vessel x with an aneurysm d, the middle section 12 of the stent body 1 corresponds to the opening of the aneurysm, one end of the middle section 12 close to the inflow section 11 corresponds to the proximal end of the opening of the aneurysm, and one end of the middle section 12 close to the outflow section 13 corresponds to the distal end of the opening of the aneurysm. The cover 2 which is propped by the stent main body 1 in the expansion state can block the proximal end of the aneurysm opening, and prevent or reduce the blood in the blood vessel from flowing into the aneurysm from the proximal end of the aneurysm opening so as to improve the healing efficiency of the aneurysm.

It is noted that the proximal end of the aneurysm opening refers to the end close to the heart, and the distal end refers to the end far away from the heart. Within the blood vessel, blood flows from the proximal end to the distal end.

Referring to fig. 6 of the specification, when a stent is not implanted in a blood vessel having an aneurysm, blood in the blood vessel enters the aneurysm from the distal end of the opening of the aneurysm, forms a vortex in the aneurysm, and exits the aneurysm through the proximal end of the opening of the aneurysm.

Referring to the description of fig. 6, after a stent is implanted into a blood vessel having an aneurysm, the amount of blood in the blood vessel entering the aneurysm decreases immediately, only small eddies exist, and most of the blood flow flows in from the proximal end of the aneurysm opening.

Referring to fig. 6 of the specification, after a period of time following the implantation of a stent into a blood vessel having an aneurysm, the aneurysm is almost filled with thrombus, and the inflow of blood flow is further reduced, leaving only a small amount of blood flow at the neck opening of the aneurysm.

Referring to fig. 6 of the specification, after a certain period of time, the aneurysm is almost completely absorbed, healed and the blood vessel is completely reconstructed.

As is clear from the above-described flow between the blood vessel and the aneurysm after the stent is implanted, when the stent is implanted in the blood vessel having the aneurysm, the blood in the blood vessel enters the aneurysm in such a manner that the blood enters the aneurysm from the distal end to the proximal end of the aneurysm opening. In the invention, the coating 2 is arranged at the position of the middle section 12 of the stent main body 1 corresponding to the proximal end of the aneurysm opening, so that the blood flow in the blood vessel can be further prevented or reduced from flowing into the aneurysm from the proximal end of the aneurysm opening, and the occlusion and repair of the aneurysm are accelerated.

Referring to the description figures 7 and 8, late and early occluded arteries are shown compared six months after stent implantation for wide tumor neck and large caliber inflow, which are potential factors for delayed occlusion in stenting non-ruptured mural aneurysms. The arrows indicate blood flow into the aneurysm. The oval 1 and 2 regions at the aneurysm opening represent the regions of inward and outward blood flow, respectively. FIG. 7 shows a late occlusion aneurysm showing a significant size, height, geometric opening of the tumor sac and high influx of the proximal tumor neck (region 1); FIG. 8 shows an early occluded aneurysm, showing minor changes in size, height, geometry and neck hemodynamics, as well as distal neck (2-region) inflow. It can be seen that, in the case of an aneurysm with advanced occlusion, a stent (blood flow guide) is covered at the proximal end of the aneurysm opening, so that the amount of blood flowing into the aneurysm opening at the proximal end can be reduced, occlusion of the aneurysm can be accelerated, and the risk of rupture of the aneurysm due to continuous blood flow entering the aneurysm opening at the proximal end can be reduced.

Preferably, the length of the cover 2 is greater than half the width of the aneurysm opening and less than the width of the aneurysm opening. It is to be noted that the length of the cover 2 can be implemented with different values depending on the width of the aneurysm opening.

It is also noted that the stent body 1 is hollow inside, tubular in shape as a whole and has a circular cross section. Optionally, the stent body 1 is a self-expandable stent made of nitinol or other biocompatible materials with shape memory, and may be selected from materials that are elastically or plastically deformable, such as balloon-expandable materials. The processing technology can be pipe laser cutting, silk thread weaving or welding, and the stent is formed by subsequent heat treatment and shaping, the stent main body 1 is of a net structure after being subjected to heat shaping, and the radial force of the stent main body 1 can be adjusted by adjusting the thickness of the cut pipe and the diameter of the silk thread for weaving. The compliance of the stent body 1 can be optimized by adjusting the mesh structure of the stent. The stent body 1 prepared by the shape memory alloy has good compressibility and can reduce the diameter of the stent to enter a smaller blood vessel. When the covered stent is conveyed to reach a focus part, the covered stent can be released from expansion to a shape before being compressed, so that when the vascular reconstruction is carried out, the covered stent with a proper length and diameter is selected to be implanted into an arterial blood vessel according to the specific condition of hemangioma to be treated, the step of balloon expansion is not needed after the covered stent reaches the focus part, and the operation is convenient. Further, the stent body 1 is preferably of a woven structure, and may be woven from 8 to 256 woven filaments, for example, and the number of the woven filaments is preferably 12 to 64. The middle section 12 of the stent body 1 is used for forming a blood supply cavity with the wall of the artery blood vessel. The inflow section 11 and the outflow section 12 have a diameter of 2-6mm and a total length of 18-42 mm. The stent may be a straight tubular shape (the diameter of the inflow section 11, the outflow section 13 and the middle section 12 is equal), or an hourglass shape (the diameter of the inflow section 11 and the outflow section 13 is larger than that of the middle section 12), and the present invention is not particularly limited thereto.

Preferably, in the present preferred embodiment, the coating film 2 includes an inner layer coating film and an outer layer coating film.

Preferably, the material of the inner layer covering film may be polytetrafluoroethylene (ePTFE) in a swollen state; or non-degradable polymer or polymer thereof which is biologically modified or carries functional drug, such as Polyurethane (PU), polyethylene glycol terephthalate (PET), polytetrafluoroethylene Polymer (PTFE), etc.; or degradable high molecular materials such as polylactic acid (PLLA or DLPLA), lactic-glycolic acid copolymer (PLGA), polyglycolic acid, polyglycolide, polylactide, polycaprolactone, polyglycolic acid, etc.; or related copolymers or natural polymers such as collagen, gelatin, chitosan, fibrinogen, and the like. Because the inner-layer film has low surface energy, the inner-layer film has good blood compatibility when being contacted with blood, so that the thrombosis can be effectively reduced, and a smooth blood flow channel can be formed.

Preferably, the outer layer film can be made of non-degradable high polymer materials, such as Polyurethane (PU), polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE), and the like; degradable high molecular materials such as polyglycolide, polylactide, polycaprolactone, polyglycolic acid and the like can also be selected; related copolymers or natural polymers such as collagen, gelatin, chitosan, fibrinogen, etc. may also be selected. The outer surface of the outer layer covering film is a biological film material which is easy to promote endothelialization, can induce thrombosis in an aneurysm or a bleeding part, promotes rapid activation and shrinkage of the aneurysm, and reduces the in-vivo occupying effect; meanwhile, endothelial cells are effectively adhered and differentiated, proliferation accelerates endothelialization of pathological part of the blood vessel, and the vascular diseases such as aneurysm and the like can be effectively treated.

It is noted that in other preferred embodiments of the invention, the covering film 2 can also be implemented as a single-layer structure, i.e. comprising only the inner covering film, or only the outer covering film.

Preferably, the coating 2 and the stent body 1 can be combined together by sewing, bonding, electrospinning, etc. The invention is not limited thereto.

Further, the covered stent further comprises a development identifier 3, wherein the development identifier 3 comprises a stent development identifier (not shown in the figure) and a covered stent development identifier 32, and the stent development identifier is mounted on the stent main body 1 and is used for identifying the position and the total length of the stent main body 1 in the blood vessel; the tectorial membrane development identifier 32 is installed at the connecting position between the tectorial membrane 2 and the stent main body 1, and is used for identifying the position of the tectorial membrane 2 in the blood vessel, ensuring that the tectorial membrane 2 can cover the proximal end of the aneurysm opening, and simultaneously avoiding the tectorial membrane 2 from covering the branch blood vessel z.

Preferably, the stent development identifier is made of gold, tantalum, platinum, PtW alloy or PtIr alloy. The bracket developing identification piece 1 is an alloy ring wrapping the bracket main body 1. Optionally, the stent development identifier 1 can also be formed by weaving an alloy wire wound around the stent main body 1, and the specific structure of the stent development identifier 1 is not specially developed in the invention.

Preferably, the coating developing marker 32 is made of gold, tantalum, platinum, PtW alloy or PtIr alloy. The coating development identifier 32 is located at the joint of the coating 2 and the stent body 1, that is, the coating development identifier 32 is located at the boundary position of the coating 2. Tectorial membrane sign spare passes through the winding of development silk support main part 1 forms, perhaps wraps up through the development silk one end or several sections of support main part 1 form, perhaps weld through the development ring and be in form on the support main part 1, be used for the sign the accurate position of tectorial membrane 2.

It should be noted that, since the vascular diseases vary greatly, the size, shape, and indications of the stent graft related to the stent body 1 and the stent graft 2 are still within the protection scope of the present invention without exceeding the core concept of the present invention.

Optionally, the stent main body 1 is a self-expanding mesh structure, and in the framework design of the stent main body 1, the coverage rate of the stent is reduced as much as possible while the radial tension and good wall-adhering performance of the stent are ensured. The coating 2 covers the middle section 12 of the stent body 1 near the inflow section 11, and does not completely cover the middle section 12. The inner-layer film of the film 2 is attached to the inner surface of the stent main body 1, the inner surface of the inner-layer film is smooth and coated with a hydrophilic coating, and the inner-layer film has good blood compatibility with blood, can effectively reduce thrombosis and can form a smooth blood flow channel. The outer-layer covering film of the covering film 2 is attached to the outer surface of the stent main body 1, the outer surface of the outer-layer covering film is a biological film material which is easy to promote endothelialization, so that thrombosis in an aneurysm or a bleeding part can be induced, the aneurysm is promoted to be rapidly activated and reduced, and the occupied effect in a body is reduced; meanwhile, endothelial cells are effectively adhered and differentiated, proliferation accelerates endothelialization of pathological part of the blood vessel, and the vascular diseases such as aneurysm and the like can be effectively treated. The bare stent area of the stent main body which is not covered with the covering film 2 is not easy to cover the branch blood vessel of the area adjacent to the aneurysm due to the low coverage rate of the stent, and the blood supply function of the branch blood vessel is reserved.

The invention can be compatible with a micro catheter, a micro guide wire, a push rod and the like, and is matched with the prior art known by the technical personnel in the field. Before implantation, firstly carrying out radiography, determining the position, size, neck range and distribution condition of the aneurysm, selecting a bracket with proper specification, loading the bracket in place by a micro catheter, slowly releasing the bracket after observing the proper position of the developing point, simultaneously paying attention to fine adjustment of the position of the bracket to partially cover the aneurysm, keeping the branch blood vessel, carrying out radiography observation on the isolation effect and the unobstructed condition of the branch blood vessel after releasing, and withdrawing the surgical instrument.

The above embodiments of the present invention have been described, and the present invention is not limited to the above specific embodiments, and can be used for ostium isolation in the vicinity of arteriovenous fistula of a branch vessel, so that those skilled in the art can modify or increase the application range within the scope of the claims.

It should be noted that, in the present invention, the cover membrane 2 is disposed at one end of the middle section 12 of the stent body 1 close to the inflow section 11, and the cover membrane 2 correspondingly covers the proximal end of the aneurysm opening, so that the pressure applied to the stent body 1 can be reduced, the fatigue resistance of the entire implant can be improved, and the stent body 1 can be prevented from being damaged and the aneurysm can be prevented from being ruptured. Moreover, the stent body 1 with low metal coverage can be adopted at the part where the tectorial membrane 2 is implanted so as to improve the compliance of the implant; by partially coating the intermediate section 12 of the stent body 1, interference of the coating 2 with other branch artery vessels can be reduced, and the application range can be increased. Generally, after the stent graft is implanted, the mode of blood entering the aneurysm is changed from the distal end to the proximal end of the aneurysm opening. Research shows that wide tumor neck and large caliber inflow are potential reasons for delaying occlusion of a dense-mesh stent for treating non-ruptured side wall intracranial aneurysm, and for late-stage occlusion aneurysm, the wide tumor neck and the large caliber are covered at the proximal end of the stent main body 1 corresponding to an aneurysm opening, namely, the wide tumor neck and the large caliber are reduced to narrow tumor neck and small caliber, so that the blood inflow of the proximal tumor neck can be reduced, the occlusion of the aneurysm is accelerated, and meanwhile, the risk of aneurysm rupture caused by continuous blood flow entering at the proximal end of the tumor neck can be reduced.

According to another aspect of the present invention, the present invention further provides a film coating method comprising:

when the covered stent is in a contraction state, controlling the covered stent to enter a blood vessel with aneurysm, and enabling one end, close to the inflow section 11, of the middle section 12 of the stent main body 1 to correspond to the proximal end of the opening of the aneurysm;

allowing the stent graft to switch to an expanded state, distracting the graft 2 located in the intermediate section 12 of the stent body 1 near the inflow section 11 by the stent body 1 such that the graft 2 covers the proximal end of the aneurysm opening.

It is noted that in the stent graft method provided by the present invention, the stent graft 2 covers the proximal end of the aneurysm opening to further prevent or reduce blood flow in the blood vessel into the aneurysm, thereby facilitating repair of the aneurysm.

Further, the length of the cover 2 of the covered stent is greater than half of the length of the aneurysm and less than the length of the aneurysm, so as to avoid covering branch vessels when covering the proximal end of the aneurysm opening.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims (10)

1. A stent graft, comprising:

the stent main body comprises an inflow section, an outflow section and a middle section positioned between the inflow section and the outflow section, wherein blood can flow in from the inflow section and flow out from the outflow section after passing through the middle section;

and the coating is arranged at one end, close to the inflow section, of the middle section of the stent body in a surrounding way and corresponds to the proximal end of an aneurysm opening.

2. The stent graft of claim 1, wherein the length of the graft is greater than half the length of the aneurysm opening and less than the length of the aneurysm opening.

3. The stent-graft of claim 1, wherein the stent body is a self-expanding stent.

4. The stent graft of claim 3, wherein the stent body is fabricated from a shape memory material.

5. The stent graft of claim 2, wherein the cover is attached to the middle section of the stent body by sewing, or by adhesive bonding, or by electrospinning.

6. The stent graft of claim 1, wherein the graft is a single layer of film mounted on the inside or outside of the stent body.

7. The stent graft of claim 1, wherein the graft comprises an inner graft mounted to an inner wall of the stent body and an outer graft mounted to an outer wall of the stent body.

8. The stent graft as recited in claim 7, wherein the material of the inner coating is a non-degradable polymer that is biologically modified or carries a functional drug; the outer layer film is made of non-degradable high polymer material.

9. The stent graft of any one of claims 1-8, wherein the stent graft further comprises a development marker, the development marker comprising a stent development marker and a stent graft development marker, wherein the stent development marker is mounted to the stent body for marking the position of the stent body, and the stent graft development marker is mounted at the junction of the stent graft and the stent body.

10. A method of laminating a film, comprising:

when the covered stent is in a contraction state, controlling the covered stent to enter a blood vessel with aneurysm, and enabling one end of the middle section of the stent main body, which is close to the inflow section, to correspond to the proximal end of the aneurysm opening;

allowing the stent graft to switch to an expanded state, and distracting a graft located in the middle section of the stent body close to the inflow section by the stent body, so that the graft covers a proximal end of the aneurysm opening.

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