A type of aortic branch endovascular stent

Abstract

This invention discloses an aortic branch endovascular stent graft, belonging to the field of medical device technology, comprising a branch endovascular stent graft and a branch framework. The branch endovascular stent graft includes a straight segment, a tapered segment, and a skirt segment. The small-diameter end of the tapered segment is connected to the straight segment, and the large-diameter end of the tapered segment is connected to the skirt segment. The branch framework includes a support framework and a skirt framework. The support framework includes a support segment and a separation segment. The support segment is pressed into the framework interlayer of the straight segment, and the separation segment is fitted inside the tapered segment. There is a movable gap between the separation segment and the tapered segment. The skirt framework is pressed into the framework interlayer of the skirt segment. Under continuous blood perfusion pressure, the tapered segment can undergo axial movement and bend or fold to drive the skirt segment to seal the implantation site. There is no need to worry too much about whether the implantation depth is sufficient when implanting the branch vessel. Excessive insertion is unlikely during surgery, and even insufficient insertion can achieve a precise implantation effect due to the special mechanism of this aortic branch endovascular stent graft.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an aortic branch covered stent. Background Technology

[0002] Aortic branch stent grafts are used to treat aortic lesions involving aortic arch branches or in patients with insufficient proximal anchorage of the aortic stent graft. They are typically used in conjunction with a main aortic stent graft with an implantation site for endovascular treatment.

[0003] Aortic branch endovascular stent grafts are mainly divided into two types based on whether they have a skirt: one is a skirtless aortic branch endovascular stent graft. During deployment, there is a risk that the stent graft may extend too far into the branch vessel, failing to connect with the fenestration (implantation site) of the main aortic endovascular stent graft. Figure 14 As shown; or, if the aortic branch stent graft extends too far into the aortic branch stent graft, it affects the hemodynamics of the aortic lumen, and even under continuous blood flow, the aortic branch stent graft may shift, detaching from the fenestration (implantation site) of the main aortic stent graft, forming an endoleak, such as... Figure 15 As shown. Another type is the aortic branch endovascular stent graft with a skirt. The accuracy of deployment is more critical with this type of stent graft, because if it extends excessively into the branch vessel, the skirt may fail to open. Figure 16 As shown, if the stent graft remains too long within the aortic body lumen, its impact on aortic hemodynamics is greater due to the skirt effect. Figure 17 As shown. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide an aortic branch endovascular stent graft, which has a tapered segment between the straight segment and the skirt segment, and leaves a movable gap between the separated segment of the branch skeleton and the tapered segment without rigid connection. Under continuous blood perfusion pressure, the tapered segment can move axially and bend or fold to drive the skirt segment to seal the implantation site. There is no need to worry too much about whether the implantation depth is sufficient when implanting the branch vessel. During the operation, there is basically no situation of excessive insertion. Even if the insertion is too small, under the special mechanism of this aortic branch endovascular stent graft, it can still achieve a precise implantation effect.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention discloses an aortic branch endovascular stent graft, comprising a branch endovascular graft and a branch framework; the branch endovascular graft comprises a straight tube segment, a tapered tube segment, and a skirt segment connected sequentially along the axial direction; the straight tube segment is used for implanting a branch vessel; the small-diameter end of the tapered tube segment is connected to the straight tube segment; the large-diameter end of the tapered tube segment is connected to the skirt segment; the skirt segment is used to seal the implantation port of the aortic main body endovascular stent graft from within the aortic main body endovascular stent graft; the branch framework comprises a supporting framework and a skirt framework; the supporting framework comprises a supporting segment and a separating segment; the supporting segment is pressed into the framework interlayer of the straight tube segment; the separating segment is sleeved within the tapered tube segment; there is an movable gap between the separating segment and the tapered tube segment that allows the tapered tube segment to move axially; the separating segment extends out of the skirt segment; and the skirt framework is pressed into the framework interlayer of the skirt segment.

[0006] Preferably, the support section includes a Z-shaped skeleton, which is formed by a single wire continuously spirally wound in a Z-shape along the axial direction of the straight pipe section, and multiple Z-shaped skeletons are arranged at axial intervals along the straight pipe section; the separation section includes a rhomboid skeleton, which includes V-shaped skeletons suspended from end to end, and the V-shaped skeleton is composed of a continuous closed loop of V-shaped wires. The first V-shaped skeleton is suspended on the adjacent Z-shaped skeleton, and the suspension point of the first V-shaped skeleton is clamped in the skeleton interlayer of the straight pipe section. The last V-shaped skeleton can extend out of the skirt section in the suspended state.

[0007] Preferably, the tapered pipe section, the straight pipe section, and the skirt section are all elastic membranes, and the elasticity of the tapered pipe section is equal to that of the straight pipe section.

[0008] Preferably, the tapered tube segment, the straight tube segment, and the skirt segment are all elastic membranes. The tapered tube segment has greater elasticity than the straight tube segment. The large-diameter end of the tapered tube segment is sewn to the suspension point of the last V-shaped skeleton and the previous V-shaped skeleton with absorbable sutures. After being sewn with absorbable sutures, the large-diameter end of the tapered tube segment is in a stretched state.

[0009] Preferably, the skirt frame is in a bent state in its natural state, the bending direction of the skirt frame is away from the conical tube segment, and the skirt segment forms a passage area for blood flow as the skirt frame bends.

[0010] Preferably, the skirt segment is an annular skirt segment, the skirt frame is a circular frame, and the circular frame has two radially symmetrically arranged bent segments, the bending direction of the bent segments is opposite to that of the tapered tube segment, and the circular frame is bent along the bending direction of the bent segments.

[0011] Preferably, the bent segment is a herringbone bend.

[0012] Preferably, the circular frame has two radially symmetrically arranged protruding sections, and the two protruding sections and the two bent sections are respectively located on the cross center line of the circular frame.

[0013] Preferably, the convex segment is an arc-shaped protrusion, and the outer arc of the arc-shaped protrusion faces away from the center of the circular skeleton.

[0014] Preferably, the material of the branch skeleton is an elastic shape memory alloy.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] The aortic branch endovascular stent graft of this invention features a tapered segment between the straight segment and the skirt segment, with a movable gap between the portion of the branch skeleton corresponding to the tapered segment (the separated segment) and the tapered segment, without rigid connection. This allows the tapered segment to move axially and bend or fold under continuous blood perfusion, thereby causing the skirt segment to adhere to and seal the implantation site, exposing more of the separated segment of the branch skeleton. Because it is a bare stent, it does not affect blood flow, achieving the same effect as the precise release of the aortic branch endovascular stent graft. Therefore, there is no need to worry too much about whether the aortic branch endovascular stent graft is inserted deep enough into the branch vessel, thus avoiding the problem of excessive insertion. Even if the insertion is too shallow, the special mechanism of this aortic branch endovascular stent graft can still achieve a precise implantation effect.

[0017] Other technical solutions of the present invention have achieved the following technical effects compared with the prior art:

[0018] In the aortic branch covered stent of the present invention, the tapered segment is more elastic than the straight segment and the skirt segment, and has a higher rebound function. Even if the implantation position of the aortic branch covered stent is inaccurate when the tapered segment is not connected to the rhomboid skeleton, the skirt segment can still adhere to the inner wall of the arch apex of the aortic main covered stent under the rebound effect of the tapered segment after the absorbable suture is absorbed, and expose more of the rhomboid skeleton, making it a bare stent. This prevents stent displacement and does not affect the hemodynamics of the branch vessels. Compared with the tapered segment being bent or folded by blood flow pressure, the resilient tapered segment has a higher fault tolerance and is more reliable. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained by analyzing these drawings without creative effort.

[0020] Figure 1 This is a front view schematic diagram of the aortic branch covered stent in an embodiment of the present invention;

[0021] Figure 2 This is a top view of the aortic branch covered stent in an embodiment of the present invention;

[0022] Figure 3 This is a perspective view of the aortic branch covered stent in an embodiment of the present invention;

[0023] Figure 4 This is a partial structural diagram of the interlocking point of the rhomboid skeleton and the Z-shaped skeleton in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the skirt hem segment and skirt hem frame in an embodiment of the present invention;

[0025] Figure 6 This is a three-dimensional structural diagram of the skirt hem segment and skirt hem frame in an embodiment of the present invention;

[0026] Figure 7 This is a front view structural diagram of the skirt hem segment and skirt hem frame in an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram illustrating the relationship between the aortic branch covered stent placement direction and the blood flow direction in an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of the structure of the aortic branch covered stent after being sutured with absorbable sutures in an embodiment of the present invention;

[0029] Figure 10 This is a partial structural diagram of the joint where the tapered tube and the rhomboid skeleton are sutured together with absorbable sutures in an embodiment of the present invention;

[0030] Figure 11 This is a schematic diagram of the structure of the aortic branch covered stent after the absorbable sutures have been decomposed and absorbed in an embodiment of the present invention;

[0031] Figure 12 This is a schematic diagram showing the position of the aortic branch covered stent relative to the main aortic covered stent and the branch vessels during accurate deployment in an embodiment of the present invention.

[0032] Figure 13 This is a schematic diagram showing the position of the aortic branch covered stent relative to the main aortic covered stent and the branch vessels in an embodiment of the present invention when the aortic branch covered stent is not precisely deployed;

[0033] Figure 14 A schematic diagram illustrating the positional relationship of a traditional skirtless aortic branch covered stent implanted too deeply into a branch vessel.

[0034] Figure 15 A schematic diagram illustrating the positional relationship of a traditional skirtless aortic branch covered stent when it is placed too deep within the main aortic covered stent.

[0035] Figure 16 A schematic diagram illustrating the positional relationship of a traditional aortic branch covered stent with a skirt when implanted too deeply into a branch vessel.

[0036] Figure 17 A schematic diagram showing the positional relationship between the traditional aortic branch covered stent with and without a skirt and the covered stent in the main aortic body.

[0037] Explanation of reference numerals in the attached diagram: 1. Main aortic stent graft; 2. Branch aortic stent graft; 3. Branch vessel; 4. Main vessel; 201. Straight segment; 202. Conical segment; 203. Skirt segment; 204. Z-shaped skeleton; 205. Rhomboid skeleton; 206. Skirt skeleton; 207. Absorbable suture; 208. Bent segment; 209. Outwardly convex segment. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments analyzed and obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The purpose of this invention is to provide an aortic branch endovascular stent graft to address the problems existing in the prior art. A tapered segment is provided between the straight segment and the skirt segment, and a movable gap is left between the separated segment of the branch framework and the tapered segment, without rigid connection. This allows the tapered segment to move axially and bend or fold under continuous blood perfusion pressure, thereby causing the skirt segment to adhere to and seal the implantation site, exposing more of the separated segment of the branch framework. Since the separated segment is a bare stent, it does not affect blood flow, achieving the same effect as precise release of the aortic branch endovascular stent graft. There is no need to overly consider whether the depth of the aortic branch endovascular stent graft into the branch vessel is sufficient, thus avoiding the problem of excessive insertion. Even with insufficient insertion, the special mechanism of this aortic branch endovascular stent graft can still achieve precise implantation.

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figures 1 to 17 As shown, this embodiment provides an aortic branch endovascular stent graft, including a branch endovascular graft and a branch skeleton.

[0042] The branched stent graft includes a straight tube segment 201, a tapered tube segment 202, and a skirt segment 203, which are connected sequentially along the axial direction of the branched stent graft. The straight tube segment 201 is used for implanting the branch vessel 3. The small-diameter end of the tapered tube segment 202 is connected to the straight tube segment 201, and the large-diameter end of the tapered tube segment 202 is connected to the skirt segment 203. The skirt segment 203 is used to seal the implantation site (fenestration) of the aortic main body stent graft 1 from the inside.

[0043] The branch frame includes a support frame and a skirt frame 206. The support frame includes a support section (refer to the Z-shaped frame 204) and a separation section (refer to the rhomboid frame 205). The support section is pressed into the frame interlayer of the straight pipe section 201 to maintain the shape of the straight pipe section 201. The separation section is fitted inside the tapered pipe section 202, and there is a movable gap between the separation section and the tapered pipe section 202, which allows the tapered pipe section 202 to move axially. The separation section extends out of the skirt section 203, and the skirt frame 206 is pressed into the frame interlayer of the skirt section 203 to maintain the shape of the skirt section 203.

[0044] Working principle:

[0045] The aortic branch covered stent 2 needs to be inserted into the catheter and constricted by the catheter to contract. At this time, the straight tube segment 201 and the tapered tube segment 202 contract radially, and the skirt segment 203 folds together.

[0046] Then, using a catheter and guidewire, the aortic branch covered stent 2 is implanted into the implantation site of the aortic main covered stent 1 and the branch vessel 3;

[0047] If the aortic branch covered stent 2 is deployed accurately, the end of the skirt segment 203 connected to the cone segment 202 will be located within the branch vessel 3, while the end of the skirt segment 203 away from the cone segment 202 will be located on the inner wall of the arch apex of the aortic main covered stent 1, sealing the implantation site. Figure 12 As shown, the portion of the separated segment (refer to the rhomboid skeleton 205) extending beyond the skirt segment 203 is a bare stent, so it will not obstruct the blood flow within the lumen and therefore will not affect the blood flow of the main vessel 4.

[0048] If the aortic branch stent graft 2 is not positioned accurately, and the end of the skirt segment 203 furthest from the cone segment 202 extends excessively into the lumen of the main aortic stent graft 1, it will affect the hemodynamics of the branch vessel 3. However, this effect is temporary. With continued blood perfusion, because the diameter of the end connecting the cone segment 202 and the skirt segment 203 is larger than the other end, the cone segment 202 is more likely to move axially towards the implantation site, causing it to bend or fold upwards. This allows the skirt segment 203 to adhere to the inner wall of the arch of the main aortic stent graft 1, exposing a longer bare stent (separated segment), further reducing the impact on blood flow in the main vessel 4. Figure 11 and Figure 13 As shown. Under this mechanism, when the aortic branch endovascular stent graft 2 is deployed, there is no need to consider whether the deployment position of the aortic branch endovascular stent graft 2 is accurate. Therefore, there is no need to excessively pursue whether the depth of the aortic branch endovascular stent graft 2 into the branch vessel 3 is sufficient. Consequently, during the operation, the surgeon can tend to leave more in the main aortic endovascular stent graft 1. At this time, during deployment, either the deployment is precise or the insertion into the branch vessel 3 is too shallow. There is basically no problem of the skirt segment 203 not being able to unfold due to excessive insertion into the branch vessel 3. That is, too much is left in the main aortic endovascular stent graft 1. However, under the special mechanism of this aortic branch endovascular stent graft 2, both precise insertion and insufficient insertion can achieve a good implantation effect.

[0049] This aortic branch endovascular stent graft 2 has a tapered section 202 between the straight section 201 and the skirt section 203. A gap is left between the portion of the branch skeleton corresponding to the tapered section 202 (the separated section) and the tapered section 202, without a rigid connection. This allows the tapered section 202 to move axially and bend or fold under the continuous perfusion pressure when the aortic branch endovascular stent graft 2 extends too far into the lumen of the main aortic endovascular stent graft 1, thus affecting the skirt section 203. 03. It fits snugly to seal the implantation site and exposes more of the separated segment of the branch skeleton. Since it is a bare stent, it will not affect blood flow. It achieves the same effect as the precise release of the aortic branch covered stent 2. Therefore, there is no need to worry too much about whether the aortic branch covered stent 2 is inserted into the branch vessel 3. This will prevent the problem of excessive insertion. The only issues will be precise insertion or insufficient insertion. With the special mechanism set in this aortic branch covered stent 2, both precise insertion and insufficient insertion can achieve a good implantation effect.

[0050] In one embodiment, the support section includes a Z-shaped skeleton 204, which is formed by spirally winding a single filament along the axial direction of the straight tube section 201, forming a continuous Z-shape. Multiple Z-shaped skeletons 204 are spaced axially along the straight tube section 201 and are pressed and locked within a skeleton interlayer composed of the inner and outer membranes of the straight tube section 201, preventing axial movement. The separation section includes a rhomboid skeleton 205, which is mainly composed of multiple V-shaped skeletons, each consisting of a continuous closed loop of V-shaped filaments. Multiple V-shaped skeletons are suspended sequentially, with the first V-shaped skeleton suspended on an adjacent Z-shaped skeleton 204. The suspension point of the first V-shaped skeleton is also pressed and locked within the skeleton interlayer composed of the inner and outer membranes of the straight tube section 201, preventing axial movement of the first V-shaped skeleton. The last V-shaped skeleton extends out of the skirt section 203 in the suspended state.

[0051] The Z-shaped skeleton 204 ensures radial support and flexibility for the straight tube segment 201. The rhomboid skeleton 205 provides axial support for the release of the aortic branch stent graft 2 without cladding, ensuring smooth release. Since the rhomboid skeleton 205 is a bare stent, it does not affect hemodynamics within the aortic lumen. Furthermore, the rhomboid skeleton 205 is formed by multiple interlocking V-shaped skeletons; this structure facilitates radial contraction and bending, adapting to thinner or more tortuous branch vessels 3, and facilitating the delivery of the aortic branch stent graft 2 to its target location. Under the radial constraint of the catheter, the tapered tube segment 202 compresses the multiple V-shaped skeletons, preventing axial movement of the V-shaped skeletons during catheter delivery. During catheter release, because the catheter is gradually released from the straight tube segment 201 towards the skirt segment 203, the multiple V-shaped skeletons do not fold together axially.

[0052] In one embodiment, the straight section 201, the tapered section 202, and the skirt section 203 are all elastic membranes, with the elasticity of the tapered section 202 equal to that of the straight section 201. When the aortic branch stent graft 2 is not accurately deployed, under the pressure of blood flow, the tapered section 202 will bend or fold, and the skirt section 203 will adhere tightly to the arched wall of the aortic main body stent graft 1, exposing more of the rhomboid skeleton 205, such as... Figure 11 and Figure 13 As shown. Preferably, the straight pipe section 201, the tapered pipe section 202, and the skirt section 203 are made of the same material, all of which are made of polymer materials, such as expanded polytetrafluoroethylene.

[0053] In one embodiment, the straight tube segment 201, the tapered tube segment 202, and the skirt segment 203 are all elastic membranes. The tapered tube segment 202 has greater elasticity than the straight tube segment 201. The large-diameter end of the tapered tube segment 202 is sutured to the suspension point of the last V-shaped skeleton and the previous V-shaped skeleton by absorbable suture 207. After being sutured by absorbable suture 207, the large-diameter end of the tapered tube segment 202 is in a stretched state. When the aortic branch stent graft 2 is not accurately released, as the absorbable suture 207 is decomposed and absorbed, the tapered tube segment 202 will bounce towards the straight tube segment 201, causing the skirt segment 203 to move, so that the skirt segment 203 adheres tightly to the arch apex wall of the aortic main body stent graft 1, and exposes more of the rhomboid skeleton 205, such as... Figure 11 and Figure 13 As shown. Compared to relying on blood flow pressure, relying on the elasticity of the cone segment 202 to achieve contraction makes the skirt segment 203 more reliable in adhering to the inner surface of the arch top wall of the aortic main body covered stent 1.

[0054] Preferably, during suturing, the absorbable suture 207 requires pulling the end connecting the tapered tube segment 202 and the skirt hem segment 203 to the interlocking position of the last V-shaped skeleton and the previous V-shaped skeleton. Specifically, the absorbable suture 207 is fixed by repeatedly inserting and re-inserting the absorbable suture 207 along the circumferential direction between the tapered tube segment 202 and the interlocking ring. Figure 9 and Figure 10 As shown. The straight pipe section 201, the tapered pipe section 202, and the skirt section 203 are all made of polymer materials. The straight pipe section 201 and the skirt section 203 are usually made of expanded polytetrafluoroethylene, while the tapered pipe section 202 is usually made of TPU (thermoplastic polyurethane rubber).

[0055] In one embodiment, the skirt frame 206 is naturally bent, with the bending direction of the skirt frame 206 away from the cone segment 202. The skirt segment 203 bends along the skirt frame 206, forming a passage area for blood flow. After bending along its bending line, the skirt segment 203, viewed from the front, has a V-shape with two arms, and the area between the two arms is the passage area. The purpose of this arrangement is twofold: firstly, it facilitates the folding of the skirt segment 203 and the skirt frame 206 into the catheter; secondly, when implanting the aortic branch covered stent 2, the bending line should be extended as much as possible towards the blood flow direction so that when blood flows in the aorta, it will flow between the two arms (passage area) of the V-shaped skirt segment 203. This facilitates the blood flow pushing the skirt segment 203 towards the inner surface of the arched top wall of the aortic main covered stent 1, causing the cone segment 202 to fold or bend.

[0056] In one embodiment, the skirt segment 203 is an annular skirt, and the skirt skeleton 206 is a circular skeleton. The circular skeleton has two radially symmetrically arranged bent segments 208, with the bending direction of the two bent segments 208 facing away from the tapered tube segment 202. The circular skeleton is bent along the bending direction of the bent segments 208. Existing skirt stents are often multi-peak stents. After radial compression, the number of stent wires results in a large footprint, requiring the branch-covered stent to be inserted into a larger catheter. When the patient's branch vessel 3 is thin or tortuous, it is difficult to deliver the stent to the target location. However, this aortic branch-covered stent 2 uses a circular skeleton and includes bent segments 208, which facilitates folding the skirt skeleton 206. After compression, the skirt skeleton 206 occupies only the space of four wire diameters in the radial section, far fewer than the number of stent wires occupied by multi-peak stents. Therefore, its compression performance is superior to existing technologies.

[0057] In one embodiment, the bending segment 208 is bent in a V-shape, so that the skirt frame 206 appears as a V-shape when viewed from the front. The V-shape bend can ensure that the skirt segment 203 can open smoothly after the aortic branch stent graft 2 is released, preventing the aortic branch stent graft 2 from shifting, and can also minimize the compressible volume of the aortic branch stent graft 2, so that the aortic branch stent graft 2 can be loaded into a thinner catheter, thereby adapting to patients with tortuous and stenotic branch vessels.

[0058] In one embodiment, the circular frame has two radially symmetrically arranged protruding sections 209, and the two protruding sections 209 and two bent sections 208 are respectively located on the cross center line of the circular frame. The protruding sections 209, together with the herringbone bends, control the direction of compression deformation of the skirt frame 206.

[0059] In one embodiment, the outwardly protruding segment 209 is an arc-shaped protrusion, with the outer arc of the arc-shaped protrusion facing away from the center of the circular frame. The two herringbone-shaped bending segments 208 and the two arc-shaped protruding outwardly protruding segments 209 can cause the skirt frame 206 to elongate axially and contract radially during compression.

[0060] In one embodiment, the branch skeleton is made of an elastic shape memory alloy. Specifically, the Z-shaped skeleton 204, the rhomboid skeleton 205, and the skirt skeleton 206 are all made of elastic shape memory alloy. The elastic shape memory alloy is typically a nickel-titanium alloy.

[0061] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An aortic branch covered stent, characterized by, The application relates to a branched stent and a branched endovascular stent.

2. The aortic branch debrancher stent of claim 1, wherein, The branched endovascular stent comprises a branched covering and a branched stent; the branched covering comprises a straight pipe section, a tapered pipe section and a skirt section which are connected in sequence along an axial direction; the straight pipe section is used for implanting a branched blood vessel; the small-diameter end of the tapered pipe section is connected with the straight pipe section; the large-diameter end of the tapered pipe section is connected with the skirt section; the skirt section is used for sealing an implantation port of a main aortic body covering stent from the inside of the main aortic body covering stent; the branched stent comprises a supporting stent and a skirt stent; the supporting stent comprises a supporting section and a separating section; the supporting section is pressed into a stent sandwich layer of the straight pipe section; the separating section is sleeved in the tapered pipe section; the separating section and the tapered pipe section have a movable gap which allows the tapered pipe section to move along the axial direction, and the separating section and the tapered pipe section are not rigidly connected; the separating section extends out of the skirt section; the separating section is a bare stent; the skirt stent is pressed into a stent sandwich layer of the skirt section; the skirt stent is in a bent state in a natural state; the bending direction of the skirt stent is away from the tapered pipe section; the skirt section is bent along with the skirt stent to form a passing area for blood flow; the skirt section is in a herringbone shape with two branch arms when viewed from the front after being bent along the bending line; and the passing area is between the two branch arms.

3. The aortic branch debranching stent graft of claim 1, wherein, The supporting section comprises a Z-shaped stent which is formed by continuously winding a wire in a Z-shaped spiral along the axial direction of the straight pipe section; the separating section comprises a diamond-shaped stent which comprises V-shaped stents which are hung in sequence; the V-shaped stents are composed of continuous V-shaped wire closed loops; the V-shaped stent at the head end is hung on the adjacent Z-shaped stent; the hanging position of the V-shaped stent at the head end is clamped in the stent sandwich layer of the straight pipe section; and the V-shaped stent at the tail end can extend out of the skirt section in a hanging state.

4. The aortic branch debrancher stent of claim 2, wherein, The tapered pipe section, the straight pipe section and the skirt section are all elastic membranes; and the elasticity of the tapered pipe section is equal to that of the straight pipe section.

5. The aortic branch debranching stent graft of claim 1, wherein, The tapered pipe section, the straight pipe section and the skirt section are all elastic membranes; the elasticity of the tapered pipe section is greater than that of the straight pipe section; the large-diameter end of the tapered pipe section is sewn at the hanging position of the V-shaped stent at the tail end and the V-shaped stent in front of the V-shaped stent at the tail end by using absorbable suture threads; and the large-diameter end of the tapered pipe section is in a stretched state after being sewn by using the absorbable suture threads.

6. The aortic branch debranching stent graft of claim 5, wherein, The skirt section is a circular skirt; the skirt stent is a circular stent; two bending sections which are symmetrically arranged along the radial direction are arranged on the circular stent; the bending direction of the bending sections is away from the tapered pipe section; and the circular stent is bent along the bending direction of the bending sections.

7. The aortic branch debranching stent graft of claim 6, wherein, Two outer convex sections which are symmetrically arranged along the radial direction are arranged on the circular stent; and the two outer convex sections and the two bending sections are respectively located on the cross center line of the circular stent.

8. The aortic branch debranching stent graft of claim 1, wherein, The outer convex sections are arc-shaped protrusions; and the outer arcs of the arc-shaped protrusions are away from the center of the circular stent. The material of the branched stent is an elastic shape memory alloy.

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