Stent system

Abstract

The present application relates to a stent system, which comprises a covered stent and a delivery device, the covered stent comprises a main stent and a branch stent, the branch stent is arranged on one side of the main stent, the main stent comprises a main wave coil and a main covering, the delivery device comprises a semi-constrained structure, the semi-constrained structure comprises a sheath and a diameter releasable member, the sheath releasably constrains the main stent through the diameter releasable member to make the main stent radially compressed or released, the sheath comprises a slit, the sheath is provided with two rows of opposite perforations along the axial seam, in the delivery state, the diameter releasable member passes through the perforations to make the sheath radially compress the main stent, the slit extends towards the proximal end to beyond the branch stent, so that the branch stent can be exposed from the sheath, and one end of the sheath is connected to the distal end of the sheath tube or the distal end inner surface. The stent system provided by the present application can expose the branch stent from the slit in the semi-constrained state, and is convenient for releasing the sheath.

Description

TECHNICAL FIELD

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

[0002] Aortic aneurysm and aortic dissection are currently serious diseases that endanger human life and safety. If not actively treated, the aortic aneurysm and dissection will continue to enlarge, eventually rupturing, causing serious complications and death. With the increasing number of patients with hypertension, hyperlipidemia and hyperglycemia, the incidence of aortic aneurysm and aortic dissection is also increasing significantly. Traditional open surgery for aortic aneurysm and aortic dissection has high mortality, long operation time, high incidence of postoperative complications and high surgical difficulty, while endovascular treatment has the characteristics of less trauma, fewer postoperative complications, shorter operation time and lower surgical difficulty, and has gradually become the main method for treating aortic aneurysm and aortic dissection. By implanting a covered stent in the aorta, the vascular lesions are isolated outside the covered stent, and the blood flow is constrained to flow from the inside of the covered stent, thereby achieving the purpose of protecting the blood vessels.

[0003] For aortic aneurysm or aortic dissection involving the branch of the aortic arch, abdominal aortic trunk, bilateral renal artery or superior mesenteric artery, the use of a covered stent will affect the blood supply of the arterial branch vessels. In view of this situation, a corresponding hole is provided on the covered stent to perfuse the blood flow supply of the branch vessels through the hole. The diameter of the hole is usually close to that of the branch vessels, and how to ensure that the hole exactly coincides with the branch vessels and guide the wire into the branch vessels is the key to branch reconstruction.

[0004] In order to ensure that the hole exactly coincides with the branch vessels, a common way is to use a semi-tethering structure formed by a diameter guide wire and a binding wire to constrain the stent circumferentially and make the stent be radially compressed. After the stent is released from the sheath tube of the delivery device, it is in a radially compressed state, so that the doctor can adjust the position to accurately position the stent before it is completely released. However, this semi-tethering method generally fixes the binding wire or other diameter structure on the stent, so that the stent cannot be taken out of the body after it is completely released, thereby increasing the foreign matter. In addition, for a stent system in which a guide wire is directly pre-positioned and then guided into the branch vessels, the guide wire is soft and has no directionality, so it is difficult to directly select the guide wire into the branch vessel opening along the radially compressed stent. It is necessary to use a snare to select the guide wire into the branch vessel from the other end of the branch vessel, which requires the doctor to puncture or incise the blood vessel from the other end of the branch vessel before the operation, increasing the damage to the patient. At the same time, during the snaring process, the guide wire is easily entangled with the super-hard guide wire of the main stent, increasing the operation time and surgical difficulty. SUMMARY

[0005] The present application at least solves one technical problem of how to set the envelope of the semi-constrained structure of the stent system to facilitate the removal of the envelope, thereby reducing foreign matter.

[0006] The present application provides a stent system, which comprises a covered stent and a delivery device, the delivery device comprises a sheath tube, the covered stent comprises a main stent and a branch stent, the branch stent is arranged on one side of the main stent, the main stent comprises a main coil and a main cover, the main cover is covered on the main coil, the delivery device comprises a semi-constrained structure, the semi-constrained structure comprises an envelope and a diameter releasable member, the envelope releasably constrains the main stent through the diameter releasable member to make the main stent be radially compressed or released, the envelope comprises a cut seam, the envelope is provided with two rows of opposite perforations along the cut seam which is axially seamed, in the delivery state, the diameter releasable member passes through the perforations to make the envelope radially compress the main stent, the cut seam extends towards the proximal end to beyond the branch stent, so that the branch stent can be exposed from the envelope through the cut seam, one end of the envelope is connected to the distal end or the inner surface of the distal end of the sheath tube.

[0007] In one embodiment, the envelope comprises a natural unfolded state and a folded wrapping state, in the folded wrapping state, the envelope comprises a first wrapping layer, a first folding position, a second wrapping layer, a second folding position, a third wrapping layer and a circumferential connecting position, the part of the envelope from the first folding position towards the proximal end forms the first wrapping layer, the covered stent is wrapped in the first wrapping layer, the envelope is folded outward along the first folding position from the distal end towards the proximal end in the natural unfolded state, thereby forming the second wrapping layer outside the first wrapping layer, the envelope continues to fold outward along the second folding position from the distal end, thereby forming the third wrapping layer outside the second wrapping layer; in the folded wrapping state, the cut seam on the second wrapping layer extends from the first folding position towards the proximal end to beyond the branch stent, the cut seam forms an opening towards the distal end at the partially overlapping position of the first wrapping layer and the second wrapping layer.

[0008] In one embodiment, the distal end of the diameter releasable member is sequentially stitched or passed through the perforations.

[0009] In one embodiment, the delivery device further comprises a preset catheter, the distal end of the preset catheter penetrates from the distal end of the main stent and penetrates out from the branch stent.

[0010] In one of the embodiments, the preset catheter is arranged as an adjustable bending catheter, which comprises an adjustable bending tube and an adjusting member. The adjustable bending tube comprises an extension section and an adjustable bending section, which is arranged at the distal end side of the extension section. The adjustable bending tube further comprises a limiting hole section, which is arranged at the proximal end side of the adjustable bending section. The adjusting member comprises a distal end part and an adjusting section. The distal end part of the adjusting member is connected with the distal end of the adjustable bending tube. The adjusting member passes through the limiting hole section and extends towards the proximal end, so as to form the adjusting section between the limiting hole section and the distal end part.

[0011] In one of the embodiments, the semi-constrained structure further comprises a diameter releasable member, which cooperates with the envelope to realize the radial constriction and release of the covered stent. The diameter releasable member passes through the gap between the adjusting section and the adjustable bending section.

[0012] In one of the embodiments, the delivery device comprises a sheath core assembly and a support rod. The sheath core assembly comprises an inner sheath core and an outer sheath core. The inner sheath core, the outer sheath core, the support rod and the sheath tube are sequentially sleeved from inside to outside. The inner sheath core, the outer sheath core, the sheath tube and the support rod can move relative to each other in the axial direction. The covered stent further comprises a first bare coil. The stent system comprises a rear release structure. The distal end of the outer sheath core and the proximal end of the guide head form the rear release structure. The rear release structure is used to hook the first bare coil, so as to realize the rear release of the first bare coil.

[0013] In one of the embodiments, the proximal end of the cut seam does not penetrate the proximal end of the first wrapping layer.

[0014] In one of the embodiments, the axial length of the envelope in the natural unfolding state is defined as L1, and the axial length of the main body covered stent is defined as L2. L1 and L2 satisfy: L1>2L2.

[0015] In one of the embodiments, the axial length from the first folding position to the proximal end of the envelope is defined as L3. L3 and L2 satisfy: L3≥L2.

[0016] In one of the embodiments, the covered stent comprises a first connection point, which is the connection point located at the most distal end of the main body stent when the branch stent is circumferentially connected with the main body stent. The axial length from the first connection point to the proximal end surface of the main body covered stent is defined as L5. When the envelope is in the folded wrapping state, the axial length of the cut seam is defined as L4. L4 and L5 satisfy: L4≥L5.

[0017] In one of the embodiments, the stent system further comprises a pull wire, the distal end of which is connected to the proximal end side of the first wrapping layer.

[0018] One technical effect of one embodiment of the present application is that the sheath is provided with a slit, which corresponds to the proximal end of the main support. Due to the slit and the connection between the sheath and the sheath tube, the sheath can be easily pulled out, and the sheath can be easily removed from the main support. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Structure diagram of a covered stent according to one embodiment of the present application;

[0020] Figure 2 Structure diagram of a covered stent according to one embodiment of the present application; Figure 1 Structure diagram of a covered stent according to one embodiment of the present application;

[0021] Figure 3 Structure diagram of a covered stent according to one embodiment of the present application;

[0022] Figure 4 Structure diagram of a covered stent according to one embodiment of the present application;

[0023] Figure 5 Structure diagram of a covered stent according to one embodiment of the present application;

[0024] Figure 6 Structure diagram of a covered stent according to one embodiment of the present application;

[0025] Figure 7 Structure diagram of a covered stent according to one embodiment of the present application; Figure 6 Enlarged view of A in FIG. 6;

[0026] Figure 8 Structure diagram of a covered stent according to one embodiment of the present application;

[0027] Figure 9 Structure diagram of a covered stent according to one embodiment of the present application;

[0028] Figure 10 Structure diagram of a covered stent according to one embodiment of the present application;

[0029] Figure 11 For Figure 10 Enlarged view of the middle Q;

[0030] Figure 12 For Figure 10 Right view schematic diagram of the envelope-wrapped covered stent fitting together in the state of the envelope being naturally unfolded;

[0031] Figure 13 For the structural schematic diagram of the envelope being in the natural unfolded state in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0032] Figure 14 For the structural schematic diagram of the envelope being in the folded wrapped state in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0033] Figure 15 For the structural schematic diagram of the envelope being in the natural unfolded state in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0034] Figure 16 For the structural schematic diagram of the envelope being in the folded wrapped state in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0035] Figure 17 For the structural schematic diagram of the envelope being in the fully wrapped and semi-bound state in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0036] Figure 18 For the structural schematic diagram of the envelope being in the semi-wrapped intermediate state (cut seam overlapping) in another embodiment provided by the present application (in order to better show the position of the stent wrapped in the envelope, the schematic diagram of the covered stent when the stent is not radially compressed is specially shown at the transversely corresponding position outside the envelope for position reference);

[0037] Figure 18a For Figure 18 Enlarged view of the middle B;

[0038] Figure 19Part structure schematic diagram of guide head and inner sheath core provided by an embodiment of the present application;

[0039] Figure 20 Structure schematic diagram of clamping piece in rear release structure provided by an embodiment of the present application;

[0040] Figure 21 Closable state diagram formed by clamping piece and clamping groove cooperation clamping of rear release structure provided by an embodiment of the present application;

[0041] Figure 22 Part structure schematic diagram of adjustable bending catheter in an embodiment provided by the present application;

[0042] Figure 23 Part structure schematic diagram of adjustable bending catheter in another embodiment provided by the present application; Figure 22 Radial section view;

[0043] Figure 24 Part structure schematic diagram of adjustable bending catheter in another embodiment provided by the present application (bending state);

[0044] Figure 25 Part structure schematic diagram of adjustable bending catheter in another embodiment provided by the present application (bending state);

[0045] Figure 26 Enlarged view of D in Figure 24 Enlarged view of D in

[0046] Figure 27 Enlarged view of E in Figure 26 Enlarged view of E in

[0047] Figure 28 Section view of extension section in Figure 24 Section view of extension section in

[0048] Figure 29 Structure schematic diagram of another embodiment of limiting hole part provided by the present application;

[0049] Figure 30 Structure schematic diagram of another embodiment of limiting hole part provided by the present application; Figure 6 Structure schematic diagram of another embodiment of limiting hole part provided by the present application; Figure 9 Structure schematic diagram of adjustable bending catheter cooperating with bundle diameter releasable piece when envelope setting bundle diameter releasable piece is provided in

[0050] Figure 31 Enlarged view of branch stent part in Figure 30 Enlarged view of branch stent part in

[0051] Figure 32 Schematic diagram of stent system provided by the present application for aortic arch, the stent system is sent to aortic arch along guide wire channel, then the sheath tube is withdrawn to the distal end of the covered stent to make the envelope in full wrapping and half binding state;

[0052] Figure 33 In order to be in Figure 32 A schematic diagram showing the process of pushing the adjustable catheter forward to expose it through the capsule and then adjusting it to select a branch vessel.

[0053] Figure 34 In order to be in Figure 33 A schematic diagram of removing the adjustable bend conduit based on the above.

[0054] Figure 35 In order to be in Figure 34 The diagram shows the process of further retracting the sheath to completely release the covered stent from the membrane (the first bare wave loop is hooked onto the release structure). Detailed Implementation

[0055] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0056] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0057] "Axial direction" generally refers to the length of a medical device during delivery, while "radial direction" generally refers to the direction perpendicular to the medical device's "axial direction." Based on this principle, the "axial" and "radial" directions of any component of a medical device are defined. Furthermore, when describing luminal stents or covered stents, the orientation can be defined according to the direction of blood flow in the blood vessel. In this invention, blood flow is defined as flowing from the proximal end to the distal end of the stent. In the field of interventional medical devices, for delivery devices used to implant medical devices into humans or animals, the end closer to the operator is generally defined as the "proximal end," and the end farther from the operator is defined as the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of the delivery device are defined.

[0058] The "wave loop" in this application is a closed ring structure, also known as a wave-shaped ring, made of woven or cut metallic elastic material. This metallic elastic material includes known materials used in implanted medical devices or combinations of various biocompatible materials, such as alloys of two or more single metals selected from cobalt, chromium, nickel, titanium, magnesium, and iron, as well as 316L stainless steel, nickel-titanium-tantalum alloys, or other biocompatible metallic elastic materials. The wave loop has radial expansion capability, allowing it to radially contract under external force and recover its initial shape after the external force is removed, thus maintaining its initial shape. After implantation into a lumen, its radial support force allows it to adhere tightly to the inner wall of the lumen. The waveform of the wave loop is unrestricted, including Z-shaped waves, M-shaped waves, V-shaped waves, sine waves, etc. The wave loop includes multiple peaks (also known as proximal apexes), multiple troughs (also known as distal apexes), and wave rods connecting adjacent peaks and troughs. A single peak (proximal or distal) and the two wave rods connected to that peak form a single wave.

[0059] This invention provides a support system 700, such as Figures 1-35 As shown, the stent system 700 includes a covered stent 100 and a delivery device 70. The covered stent is preferably a single-branch covered stent for the aortic arch, wherein, as... Figures 1-2 As shown, the covered support 100 includes a main support 10, a first bare wave coil 20, and a branch support 30. The main support 10 includes a main wave coil 11 and a main cover 12, with the main cover 12 covering the main wave coil 11. The main wave coil 11 is a ring structure formed by connecting multiple waveform units end to end. Here, a waveform unit refers to a single-wave structure composed of wave crests, wave rods, and wave troughs, and the shape of the waveform unit is not limited. Each main wave coil 11 can be a regular ring structure formed by multiple waveform units of equal height, or it can be an irregular ring structure including high and low waves formed by waveform units of different wave heights. Adjacent main wave coils 11 can all be regular ring structures, or they can all be irregular ring structures including high and low waves, or they can be a combination of two types of ring structures: regular ring structures and irregular ring structures including high and low waves. This is not limited here.

[0060] The main body covering 12 is a tubular structure with openings at both ends. Multiple main body wave coils 11 are arranged axially and connected through the tubular main body covering 12 to form a tubular main body support 10. The distal end of the first bare wave coil 20 is connected to the proximal end of the main body support 10, thereby exposing the first bare wave coil 20 to the outside of the main body covering 12.

[0061] The branch stent 30 is connected to one axial side of the main stent 10, and the lumen of the branch stent 30 is connected to the lumen of the main stent 10. In this embodiment, the covered stent 100 serves as a single-branch covered stent for the aortic arch and can be implanted into curved blood vessels. When the covered stent 100 is implanted in a curved blood vessel, the first side 10a of the main stent 10 is defined as the side that conforms to the greater curvature of the blood vessel, and the second side 10b of the main stent 10 is defined as the side that conforms to the lesser curvature of the blood vessel. Taking the curved shape of the main stent 10 implanted in the aortic arch as an example, the first side 10a and the second side 10b of the main stent 10 are further explained. The first side 10a is the side of the main stent 10 closer to the branch of the aorta (greater curvature), and the second side 10b is the side of the main stent 10 away from the branch of the aorta (lesser curvature). The first side and the second side each occupy an arc of 180° circumferentially.

[0062] The branch bracket 30 is connected to the first side 10a of the main bracket 10. The branch bracket 30 can be located at the middle of the arc of the first side 10a. The main bracket 10 also includes multiple connectors (not shown). The connectors connect two adjacent main corrugated coils 11. The connectors are located on the first side 10a of the main bracket 10. The connector can be formed by one end of a main corrugated coil 11 extending to an adjacent main corrugated coil 11, or multiple separate connectors can connect two adjacent main corrugated coils 11 together axially. The connectors are continuously arranged axially at the circumferential center of the first side 10a. The branch bracket 30 is located on the circumferential central axis of the first side 10a. Some connectors are located on the same axial line as the branch bracket 30, so that the coating bracket 100 can be easily bent toward the second side 10b, but not easily bent toward the first side 10a. The connectors near the branch bracket 30 can be located on both sides of the branch bracket 30 axially to avoid the position of the branch bracket 30.

[0063] like Figures 1-2 As shown, the main support 10 includes an annular support 13 and a window 14. The window 14 is disposed on one side of the main support 10 and is used to communicate with the branch support 30. The annular support 13 is disposed along the window 14 and is made of developing material. It is used to support the edge of the window 14 and to show the position of the branch support 30.

[0064] The branch bracket 30 includes a first end 31, a middle section 32, and a second end 33. The first end 31 and the second end 33 are two opposite ends. The middle section 32 is located between the first end 31 and the second end 33. The first end 31 of the branch bracket 30 can be directly connected circumferentially to the window 14 of the main bracket 10, thereby connecting the branch bracket 30 to one side of the main bracket 10. Figure 1In other embodiments, the covered stent 100 further comprises a ring-shaped connecting membrane connecting the intermediate section 32 of the branch stent 30 to the main stent 10, so as to connect the branch stent 30 to the main stent 10, and to allow the first end 31 of the branch stent 30 to be located within the lumen of the main stent 10, and the second end 33 of the branch stent 30 to be located outside the lumen of the main stent 10.

[0065] The outer diameter of the branch stent 30 is smaller than the inner diameter of the ring-shaped support 13, and the radial width of the ring-shaped connecting membrane is greater than the difference between the inner diameter of the ring-shaped support 13 and the outer diameter of the branch stent 30, so that the ring-shaped connecting membrane can allow the branch stent 30 to float up and down (radially of the main stent 10), and the branch stent 30 can swing along the circumferential direction of the tube by 360°, so that the opening of the second end 33 of the branch stent 30 is adjustable, and after the covered stent 100 is implanted into the blood vessel, when a guide wire is used to access the branch blood vessel, the opening of the second end 33 of the branch stent 30 is more easily aligned with the branch blood vessel, and the complexity of the anatomical form has less influence on the alignment of the opening of the second end 33 of the branch stent 30 with the branch blood vessel. The ring-shaped connecting membrane connects the intermediate section of the branch stent 30, so that part of the branch stent 30 is located outside the main stent 10, and part of the branch stent 30 is located inside the main stent 10, which can ensure that the second end 33 of the branch stent 30 floats down to be flush with the main stent 10, and the opening of the second end 33 of the branch stent 30 is adjustable within the range of the ring-shaped support 13, which is more convenient to adapt to different anatomical forms.

[0066] In combination Figures 3-5 As shown in FIG. 1, the delivery device 70 comprises a sheath core assembly 71, a support rod 72, a sheath tube 73, a semi-constrained structure, a handle assembly 75, and a pre-positioning catheter. The sheath core assembly 71 comprises an inner sheath core 711 and an outer sheath core 712. The inner sheath core 711, the outer sheath core 712, the support rod 72, and the sheath tube 73 are sequentially sleeved from inside to outside, and the inner sheath core 711, the outer sheath core 712, and the sheath tube 73 can move axially relative to each other. The support rod 72 is sleeved outside the sheath core assembly 71.

[0067] The delivery device 70 further comprises a guide head 76 arranged at the distal end of the inner sheath core 711. The distal end of the support rod 72 and the proximal end of the guide head 76 are spaced apart to form a loading space for the covered stent 100. Figure 3 In combination Figure 5The half-constrained structure includes a sheath 79 for releasably constraining the covered stent 100 to be radially compressed or released, and the sheath 79 is connected to the distal end of the sheath tube 73 or the support rod 72, so as to facilitate the removal of the sheath 79 from the main stent 10 to be taken out of the patient's body; further, in other embodiments, the half-constrained structure can also include a diameter-releasable member 74, and the sheath 79 cooperates with the diameter-releasable member 74 to form the half-constrained structure, and the sheath 79 realizes the radial compression and release of the main stent 10 by cooperating with the diameter-releasable member 74. In this embodiment, the covered stent is preferably an aortic arch single-branch covered stent.

[0068] In combination Figure 9 As shown in the figure, the distal end of the sheath tube 73 is provided with a developing member 731, which can be a developing ring, for indicating the position of the distal end of the sheath tube 73.

[0069] The delivery device 70 further includes a sheath 79, which in one embodiment is connected to the distal end of the support rod or the distal end of the sheath tube of the delivery device 70, and the sheath 79 is a tubular film, which is used to radially compress the main stent 10. When the preset catheter is provided, the relationship between the circumference W of the sheath 79 and the lumen circumference C of the covered stent 100 at the corresponding position satisfies: W≤C / 4; so that the compression radius of the covered stent 100 in the half-constrained state is small, that is, the degree of radial compression of the covered stent 100 is kept at a relatively large degree; on the one hand, it can ensure that the channel size is slightly larger than the outer diameter of the preset catheter, so that the delivery of the preset catheter is smooth, that is, even if the stacked coils of the radially compressed covered stent 100 are crowded, the preset catheter is preset in the covered stent 100, and due to the soft wrapping of the sheath 79, it can provide radial soft buffering and reduce the friction between the preset catheter and the stacked main coils 11, and the smoothness of the delivery can still be ensured when it needs to be delivered in the axial direction; on the other hand, it can ensure that the channel size is not too large, which can limit the radial space of the preset catheter to some extent, and can avoid the bending of the preset catheter in the channel during delivery; in addition, the radial compression of the sheath 79 on the covered stent 100 is smaller than the compression of the sheath tube 73 on the covered stent 100, and the friction on the preset catheter is smaller, and due to the uniformity of the wrapping of the sheath 79 on the main stent 10 in the axial direction of the main stent 10, it can also avoid the situation that when the covered stent 100 is constrained by the wire, the part not bound by the wire is lifted up due to the self-expanding force of the main coil 11, resulting in a larger channel space, and the preset catheter bends at the position with a larger channel space.

[0070] It can be understood that, in order to make the radial compression degree of the envelope 79 greater, the relationship between the circumference W of the envelope 79 and the lumen circumference C of the covered stent 100 at the corresponding position can also satisfy W≤C / 5; that is, even if the envelope 79 wraps the covered stent 100, the channel space of the covered stent 100 after radial compression is small, and since the envelope 79 is a flexible film, the radial compression of the covered stent 100 is soft wrapping, when the preset catheter is preset in the space in the axial direction, the preset catheter can also smoothly slide in the axial direction along the narrow space, and at the same time, the envelope 79 radially extrudes the covered stent 100, which can avoid the bending of the preset catheter in the channel space.

[0071] As shown in Figures 6-7 and Figures 8-14 , the envelope 79 includes a small section of the cut seam 791, which is correspondingly arranged at the proximal end side of the main stent 10. The cut seam 791 can extend in the axial direction or deviate from the axial direction. The proximal end of the cut seam 791 passes the branch stent 30, which can expose the branch stent 30 from the cut seam 791, and the proximal end of the first bare coil 20 is hooked on the rear release structure formed by the sheath core assembly 71. At this time, the first main coil 11 and the first bare coil 20 are still radially compressed to a certain extent, which can also fine-tune the release position of the main stent 10 or the position of the branch stent 30 corresponding to the branch blood vessel before the stent system 700 is released, and at the same time, after the stent system 700 is accurately positioned, the proximal end 79a or the distal end of the envelope 79 can be easily pulled to remove the envelope 79 from the main stent 10.

[0072] In one embodiment, as shown in Figures 6-7 , the distal end of the cut seam 791 starts from the distal end 79b of the envelope 79, that is, during the release process of the main stent 10, the cut seam 791 forms a non-closed opening at the proximal end of the main stent 10. The proximal end 79a of the envelope 79 is connected to the distal end of the support rod 72 in the circumferential direction. The support rod 72 can move relative to the sheath core assembly 71 in the axial direction, so that after the stent system 700 constructs the branch channel and positions the covered stent 100 to the release position, due to the arrangement of the cut seam 791, the distal end 79b of the envelope 79 is expanded by the natural expansion of the main stent 10. The support rod 72 can be easily pulled out to release the main stent 10 from the envelope 79.

[0073] Further, the bundle diameter releasable member 74 can be provided at the cut 791 of the envelope 79. When the bundle diameter releasable member 74 is provided, two rows of perforations 798 are provided along the cut 791 of the envelope 79. The distal end of the bundle diameter releasable member 74 is sequentially stitched or passed through the perforations 798 along the cut 791 of the envelope 79. When the sheath 73 is retracted, the envelope 79 is removed, and the distal end 79b of the envelope 79 is radially compressed by the bundle diameter releasable member 74, thereby maintaining the main stent 10 in a semi-tethered state. The envelope 79 can be removed after the bundle diameter releasable member 74 is retracted, thereby releasing the main stent 10 and removing the envelope 79 from the patient's body, thereby reducing foreign matter. In one embodiment, the bundle diameter releasable member 74 can include a bundle diameter guide wire 741 that is sequentially passed through the perforations 798 along the cut 791 of the envelope 79. When the bundle diameter guide wire 741 is retracted, the envelope 79 is expanded at the proximal end, thereby facilitating the removal of the envelope 79 from the stent graft 100 by the delivery device 70. The proximal end of the bundle diameter releasable member 74 is connected to a safety catch 743 that is releasably fixed to the handle assembly 75, thereby preventing the proximal end of the stent graft 100 from being released by mistake.

[0074] As shown in FIG. 1, the support rod 72 includes a first channel 721 and a second channel 722 that extend through the support rod 72 in the axial direction. The first channel 721 is used for the sheath core assembly 71 to pass through in the axial direction, and the second channel 722 is used for the pre-positioning catheter to pass through. Figure 4 As shown in FIG. 1, the support rod 72 includes a first channel 721 and a second channel 722 that extend through the support rod 72 in the axial direction. The first channel 721 is used for the sheath core assembly 71 to pass through in the axial direction, and the second channel 722 is used for the pre-positioning catheter to pass through.

[0075] The bundle diameter releasable member and the envelope cooperate to form a semi-tethered state of the main stent. The envelope releasably tethers the main stent by using the bundle diameter releasable member, so that the main stent is radially compressed or untethered. In order to facilitate the removal of the envelope from the main stent and not to affect the established branch channel during the removal of the envelope from the main stent, one end of the envelope can be connected to the inner surface of the sheath, thereby facilitating the removal of the envelope from the main stent by retracting the sheath. In one embodiment, as shown in FIG. 1, the envelope 79 includes a naturally expanded state and a folded state. The envelope 79 is in the naturally expanded state before being assembled into the stent system 700. Figures 8-9 Figure 8 ​As shown, the envelope 79 is in a tubular shape in the natural unfolded state, the envelope 79 includes a slit 791, a proximal end 79a and a distal end 79b, and the axial length LI of the envelope 79 in the natural unfolded state is greater than the axial length L2 of the main body covering 12, and LI and L2 satisfy: LI > 2L2. When the covering stent 100 is loaded into the envelope 79 to form the stent system 700 described above, the envelope 79 is in a folded wrapping state, and in the folded wrapping state of the envelope 79, the envelope 79 includes a first wrapping layer 792, a first folding portion 793, a second wrapping layer 794, a second folding portion 795, a third wrapping layer 796, and a circumferential connecting portion 797. The portion of the envelope 79 from the first folding portion 793 toward the proximal end 79a forms the first wrapping layer 792, and the covering stent 100 is wrapped in the first wrapping layer 792. The envelope 79 is folded outward from the distal end in the natural unfolded state along the first folding portion 793 toward the proximal end, thereby forming the second wrapping layer 794 outside the first wrapping layer 792. The envelope 79 continues to fold outward along the second folding portion 795 toward the distal end, thereby forming the third wrapping layer 796 outside the second wrapping layer 794. The slit 791 extends from the first folding portion 793 toward the proximal end to beyond the branch stent 30, and the slit 791 is formed at the partially overlapping portion of the first wrapping layer 792 and the second wrapping layer 794, i.e., the slit continuously extends between the first wrapping layer 792 and the second wrapping layer 794 when the envelope 79 is in the natural unfolded state, and the slit on the first wrapping layer 792 and the slit on the second wrapping layer 794 are symmetrical along the first folding portion 793, so that when the envelope 79 is folded into the folded wrapping state, the slit forms an opening toward the distal end at the partially overlapping portion of the first wrapping layer and the second wrapping layer, as shown in FIG. 8B. Figures 8-12The envelope is provided with two rows of perforations along the axial seam 791. The perforations are sequentially arranged from the distal end of the axial seam to the position close to the branch stent. In the delivery state, the radial compression member passes through the perforations to radially compress the envelope on the main stent, and the branch stent can be exposed from the axial seam on both sides where no perforations are arranged. The perforations can only pass through the inner and outer of the first wrapping layer, only pass through the inner and outer of the second wrapping layer, or pass through the inner and outer of the first wrapping layer 792 and the second wrapping layer 794 respectively, which is not limited here. The distal end of the radial compression member 74 is sequentially stitched or passed through the first wrapping layer and the second wrapping layer along the perforations on both sides of the axial seam 791, or only passes through one of the wrapping layers to achieve the radial compression of the main stent in the folded wrapping state. When there are two or more wrapping layers wrapped on the main stent, as long as at least one wrapping layer remains closed, the radial compression of the main stent can be achieved. The radial compression member is sequentially passed through the perforations from the distal end of the axial seam to the position close to the branch stent, so that the axial seam 791 corresponding to the branch stent is not closed, thereby achieving the partial closure of the axial seam 791, and the branch stent is exposed from the axial seam corresponding to the position of the first wrapping layer 792 and the second wrapping layer 794. In this embodiment, the covered stent is preferably an aortic arch single-branch covered stent.

[0076] The axial length of the first folding position 793 to the proximal end of the envelope 79 is defined as L3 (i.e. the axial length of the first wrapping layer is L3), and L3 and L2 satisfy: L3≥L2, and in one of the embodiments, L3 is equal to L2. When the envelope is in the folded wrapping state, the axial length of the axial seam 791 is defined as L4. The covered stent 100 comprises a first connection point 103, which is the connection point of the branch stent 30 and the main stent 10 located at the distal end of the main stent 10. The axial length of the first connection point to the proximal end of the main covered stent 12 is defined as L5, and L4 and L5 satisfy: L4≥L5, so that the branch stent can be exposed from the second wrapping layer.

[0077] One end of the envelope 79 is circumferentially connected to the distal end of the sheath tube 73 or the distal inner surface close to the distal end. The circumferential connection 797 is located at the distal end of the envelope 79 in the natural unfolded state. The envelope 79 is connected to the distal end of the sheath tube 73 or the distal inner surface close to the distal end of the sheath tube through the circumferential connection 797. In the stent system 700, as shown in Figure 9 The envelope 79 is in a folded wrapping state. When the stent system 700 is delivered to the position to be released, the envelope 79 further includes a fully wrapped semi-restricted state and a wrapped semi-released state during the retraction of the sheath tube 73. As Figure 10As shown, with the retraction of the sheath 73, first, the distal end of the sheath 73 is retracted to the distal end of the main body support 10, so that the whole covered stent 100 wrapped by the envelope 79 is exposed from the sheath 73, and the third wrapping layer 796 is folded from the outside of the second wrapping layer 794 to the proximal end side of the second wrapping layer 794 (in the wrapping folded state, since the first wrapping layer 792 and the second wrapping layer 794 are both on the inside of the third wrapping layer 796, and the sheath 73 cannot directly transmit force to the second wrapping layer 794 and the first wrapping layer 792, the retraction of the sheath 73 will not pull the second wrapping layer 794, and even less the first wrapping layer 792, before the third wrapping layer 796 is completely folded to the proximal end side of the second wrapping layer 794, so that the first wrapping layer 792 and the second wrapping layer 794 cooperate to well radially compress the covered stent 100 in the first wrapping layer 792, and at this time, the part of the incision 791 at the proximal end side of the branch stent is closed by the bundle diameter releasable member, and the whole covered stent 100 is radially compressed), so that the third wrapping layer 796 and the second wrapping layer 794 are wrapped outside the first wrapping layer 792, as shown in Figure 10 As shown, at this time, the envelope 79 is in a full-wrapping and semi-restraining state of double-layer wrapping the covered stent 100, the inner layer is the first wrapping layer 792, and the outer layer is the axially connected second wrapping layer 794 and third wrapping layer 796; at this time, the branch stent is exposed from the incision, and the whole main body support is in a full-wrapping and semi-restraining state, which can adjust the alignment of the branch stent and the branch blood vessel opening, and is beneficial to the selection of the pre-positioning guide wire or pre-positioning catheter into the branch blood vessel. After the pre-positioning guide wire or pre-positioning catheter is selected into the branch blood vessel, the axial position of the main body support is kept unchanged, and then the bundle diameter releasable member is retracted to release the closed state of the incision, so that the distal end of the double-layer wrapping is in a partially open state, at this time, the envelope is in a wrapping semi-released state, and the proximal end of the main body support 10 is partially released.

[0078] Afterwards, if the sheath 73 continues to be withdrawn, the first fold 793 is withdrawn, the sheath 73 will pull the first wrapping layer 792 through the second wrapping layer 794, so that the distal end of the first wrapping layer 792 is folded and gradually moves towards the proximal end until the first wrapping layer 792 is completely removed from the main body stent 10, at this time the envelope 79 is in a removed state. In the folded wrapping state, the axial length of the first fold 793 to the distal end surface of the main body covering 12 is defined as L6, L6>L4≥L5, so that the proximal end of the incision on the first wrapping layer is not through, which can make the first wrapping layer always surround the sheath core during the process of removing the envelope, especially the process of peeling off the main body stent with the first wrapping layer of the envelope folded, so that the envelope does not deviate from the sheath core and is difficult to be collected in the sheath and stacked at the distal end of the sheath during the subsequent withdrawal of the delivery device, thereby causing excessive friction with the inner wall of the blood vessel. In one embodiment, L6 Figure 8 L5

[0079] On the one hand, for the main body stent 10 having a radial self-expanding ability, since the envelope 79 radially binds the main body stent 10, there is still a large radial support force of the main body stent 10 on the envelope 79 during the removal of the envelope, thereby causing a large friction force of the envelope 79 removed from the main body stent 10. For the interventional surgery, the operating end is outside the patient's body and the implanted device is inside the patient's body, and the process requiring a large force is not suitable for use in the interventional device. In the stent system 700 provided in the embodiment, due to the radial self-expanding force of the main body stent 10, when the incision 791 is released from the closed state of the diameter-releasable member, the envelope can form a flared portion at the position corresponding to the incision, and with the withdrawal of the sheath 73, the first wrapping layer 792 wrapped on the innermost side is gradually removed from the proximal end to the distal end of the main body stent 10 from the distal end to the proximal end, rather than being directly pulled out from the proximal end 79a of the envelope 79 and removed from the main body stent 10, thereby requiring a smaller force to remove the envelope 79 and making it easier to remove the envelope from the main body stent without affecting the release position of the main body stent. On the other hand, since the diameter-releasable member, the pre-positioned guide wire or the pre-positioned guide tube all pass through the support rod in the axial direction and extend in the axial through hole in the support rod, one end of the envelope is connected to the distal end or the inner surface of the distal end of the sheath 73, rather than being directly connected to the push rod, which can reduce the influence on the diameter-releasable member, the pre-positioned guide wire or the pre-positioned guide tube during the removal of the envelope.

[0080] In other embodiments, in combination with Figure 9As shown, the stent system further comprises a pull wire 80, the distal end of which is connected to the proximal side of the first wrapping layer 792, and the proximal end of which extends to the proximal end of the delivery device for facilitating the operation of the pull wire. When the envelope 79 is completely removed from the main stent 10, the envelope can be pulled back into the sheath tube 73 by the pull wire due to the folding of the envelope 79 to the distal end of the sheath tube 73, and then the sheath tube 73 is pushed forward to the guide head 76, so that the delivery device can be conveniently withdrawn from the human body, and the envelope 79 will not be exposed outside the sheath tube 73 during the withdrawal process. In other embodiments, the pull wire 80 can also be symmetrically arranged in two or more than two uniform distribution along the circumference of the envelope, so that when the pull wire pulls back the envelope, the envelope is symmetrically stressed along the circumference, and it is easier to pull back the envelope into the sheath tube. The proximal end of the envelope 79 can also be provided with a transverse limiting line, which can be arranged on the envelope 79 by heat melting, and the pull wire 80 can pass through the limiting line to be fixed on the envelope, thereby increasing the connection reliability of the pull wire 80 and the envelope 79.

[0081] In other embodiments, the diameter releasable member can also not be provided, and only the envelope 79 can be used to complete the half restraint of the main stent 10 and achieve the easy removal of the envelope 79 during the removal of the envelope 79. For example, Figures 15-18As shown, the envelope 79 includes a naturally expanded state and a folded wrapping state. The envelope 79 belongs to the naturally expanded state before being assembled to the stent system 700, at which time the envelope 79 is a tubular membrane, the envelope 79 includes a cut seam 791, a proximal end 79a and a distal end 79b, and the axial length L1 of the envelope 79 in the naturally expanded state is greater than the axial length L2 of the main body covering membrane 12, and L1 and L2 satisfy: L1>2L2. When the covering stent 100 is loaded into the envelope 79 to form the above stent system 700, the envelope 79 is in the folded wrapping state, and in the folded wrapping state of the envelope 79, the envelope 79 includes a first wrapping layer 792, a first folding portion 793, a second wrapping layer 794, a second folding portion 795, a third wrapping layer 796, and a circumferential connection portion 797. The portion of the envelope 79 from the first folding portion 793 towards the proximal end 79a forms the first wrapping layer 792, and the covering stent 100 is wrapped in the first wrapping layer 792. The envelope 79 is folded outward along the first folding portion 793 from the distal end in the naturally expanded state towards the proximal end, so as to form the second wrapping layer 794 outside the first wrapping layer 792. The envelope 79 continues to fold outward along the second folding portion 795 towards the distal end, so as to form the third wrapping layer 796 outside the second wrapping layer 794. In the folded wrapping state, the cut seam 791 on the second wrapping layer extends from the first folding portion 793 towards the proximal end to beyond the branch stent 30, wherein the axial length of the first folding portion 793 to the proximal end of the envelope 79 is defined as L3, and L3 and L2 satisfy: L3>L2. In one embodiment, L3 is greater than or equal to the L2 plus the wave height of the first bare coil; the axial length of the cut seam 791 is defined as L4, the covering stent 100 includes a first connection point 103, the first connection point 103 is the connection point of the branch stent 30 and the main body stent 10 when they are circumferentially connected, which is located at the most distal end of the main body stent 10, the axial length of the first connection point to the proximal end surface of the main body covering membrane 12 is defined as L5, and L4 and L5 satisfy: L4≥2L5. In the process of removing the envelope, when the cut seam overlaps, the cut seam can overlap the main body covering membrane for a longer length at the proximal end of the main body covering membrane, and the timing of forming a non-closed opening of the cut seam at the proximal end of the main body covering membrane is better.

[0082] As shown, one end of the envelope 79 is circumferentially connected to the distal end of the sheath tube 73, and the circumferential connection portion 797 is located at the distal end of the envelope 79 in the naturally expanded state. The envelope 79 is connected to the distal end of the sheath tube 73 or the distal inner surface of the sheath tube close to the distal end through the circumferential connection portion 797. In the stent system 700, as shown, Figure 16 As shown, the envelope 79 is in the folded wrapping state. When the stent system 700 is delivered to the position to be released, the envelope 79 also includes a fully wrapped semi-restrained state, a semi-wrapped intermediate state and a removal state during the retraction of the sheath tube 73. Figures 17-18As shown, as the sheath 73 is retracted, firstly, the distal end of the sheath 73 is retracted to the distal end of the main support 10, thereby exposing the entire covered support 100, which is wrapped by the membrane 79, from the sheath 73. The sheath 73 causes the third wrapping layer 796 to fold from the outside of the second wrapping layer to the proximal side of the second wrapping layer 794 (since the first wrapping layer 792 and the second wrapping layer 794 are both inside the third wrapping layer 796, and the sheath 73 cannot directly transmit force to the second wrapping layer 794 and the first wrapping layer 792 in the folded state, therefore...). Before the third wrapping layer 796 is completely folded over to the proximal side of the second wrapping layer 794, the retraction of the sheath 73 will not pull on the second wrapping layer 794, nor on the first wrapping layer 792. This allows the first and second wrapping layers 792 to work together to effectively radially compress the covered stent 100 within the first wrapping layer 792, and since there are no slits 791 on the second wrapping layer 794, the entire covered stent 100 is radially compressed. This ensures that the third and second wrapping layers 796 together wrap around the first wrapping layer 792. Figure 17 As shown, at this time, the membrane 79 is in a fully enclosed, semi-bound state of double-layered wrapping of the covered support 100. The inner layer is the first wrapping layer 792, and the outer layers are the axially connected second wrapping layer 794 and third wrapping layer 796. Continuing to retract the sheath 73, the first fold 793 retracts, and the sheath 73 pulls the first wrapping layer 792 through the second wrapping layer 794, causing the distal end of the first wrapping layer 792 to fold and gradually move towards the proximal end. Simultaneously, the slit 791 shows an overlap of the inner and outer layers at the distal end, indicating a semi-enclosed intermediate state. Figure 18 Combination Figure 18a As shown, during the release of the main support 10, the slit 791 forms a non-closed opening at the proximal end of the main support 10. When the proximal end of the overlapping slit 791 moves to the main support 10, the proximal end of the main support 10 is gradually released until the first wrapping layer 792 is completely removed from the main support 10. At this time, the wrapping 79 is in the removed state.

[0083] For the main body stent 10 with self-expanding ability in the radial direction, since the envelope 79 is radially constrained to the main body stent 10, the main body stent 10 still has a large radial support force to the envelope 79 in the radial direction during the envelope removal, so that the friction force of the envelope 79 removed from the main body stent 10 is large. For the interventional operation, the operating end is outside the patient's body, and the implanted implant is inside the patient's body. For the process that requires a larger force to be achieved, it is not suitable to be used in the interventional instrument. In the stent system 700 provided in the embodiment, due to the radial self-expanding force of the main body stent 10, when the proximal end of the overlapping portion of the cut seam 791 moves to the proximal end of the main body stent 10, the double-layer wrapped envelope 79 can form a flared portion in the range of the overlapping position of the distal cut seam 791, and at this time, the first wrapping layer 792 wrapped on the innermost side is gradually removed from the proximal end to the distal end of the main body stent 10, instead of being directly pulled out from the proximal end 79a of the envelope 79 and removed from the main body stent 10, so that the force required for the removal of the envelope 79 is smaller and easier to achieve.

[0084] In other embodiments, the diameter-releasable member 74 can also include a releasable suture structure that axially penetrates the perforations 798 near the edges on both sides of the cut seam 791 to compress the radial direction of the proximal end of the covered stent 100 into the envelope 79. The diameter-releasable member 74 is not limited here, and only needs to cooperate with the cut seam 791 of the envelope 79 to achieve the radial compression and release of the entire covered stent 100.

[0085] As shown in Figure 3 The handle assembly 75 includes a fixed handle 751, a sliding handle 752, and a wing portion 753. The proximal end of the fixed handle 751 includes a guide rail 7511 extending towards the proximal end. The proximal end of the sheath tube 73 is connected to the sliding handle 752, which is arranged on the proximal end side of the fixed handle 751 around the guide rail 7511, so that the sliding handle 752 slides along the guide rail 7511 to drive the sheath tube 73 to retract, so as to release the lumen stent from the distal end of the sheath tube 73. The wing portion 753 is arranged on the proximal end side of the guide rail, and a passage is provided in the wing portion 753 and communicates with the passage in the support rod 72, for the adjustable bending catheter to pass out, so as to facilitate the operation of the adjustable bending catheter.

[0086] As shown in Figures 19-21As shown, the delivery device further comprises a rear release structure formed by the distal end of the outer sheath core 712 and the proximal end of the guide head 76, which is used to hook the first bare coil 20, so as to realize the rear release of the first bare coil 20 at the proximal end of the stent graft 100. The delivery device comprises a clamping member 77 connected to the distal end of the outer sheath core 712; the clamping member 77 comprises a plurality of clamping claws 771 and a connecting portion 772, and the proximal end of the guide head 76 is provided with a clamping portion 761 and a clamping groove 762; the plurality of clamping claws 771 radiate and disperse from the connecting portion 772 towards the distal end, and the connecting portion 772 fixes the plurality of clamping claws 771 to the distal end of the outer sheath core 712, wherein the plurality of clamping claws 771 can be matched with the clamping groove 762 one by one respectively; the clamping portion 761 is arranged on the distal end side of the clamping groove 762, and the clamping portion 761 comprises a clamping surface 7611 and a clamping step 7612; the inner circumferential surface of the sheath tube 73 is sleeved on the clamping surface 7611, and the distal end surface of the sheath tube 73 abuts against the clamping step 7612, so as to facilitate the guide head 76 to be embedded into the distal end of the sheath tube 73, and at the same time, the matched portions of the clamping claws 771 and the clamping groove 762 are accommodated in the sheath tube 73. It can be understood that the cooperation of the clamping member 77 and the clamping groove 762 forms the above-mentioned releasable rear release structure, that is, the rear release structure comprises a closable state formed by the cooperation of the clamping member 77 and the clamping groove 762, and an openable state formed by the mutual separation of the clamping member 77 and the clamping groove 762; when in the closable state, the rear release structure can temporarily fix the first bare coil 20 at the proximal end of the stent graft 100 before the rear release.

[0087] The preset catheter extends along the cavity of the main stent 10 and is axially movable relative to the main stent 10, and the distal end of the preset catheter penetrates from the distal end of the main stent 10 and exits from the branch stent 30. The preset catheter can be directly selected into the branch blood vessel, and the preset catheter does not need to be punctured or incised through the other end of the branch blood vessel to capture the branch guide wire, thereby reducing the pain of the patient, avoiding the problem that the guide wire is easily entangled with the super-hard guide wire of the main stent 10 during the capturing process, and reducing the operation difficulty of the doctor during the branch selection process and the operation time.

[0088] As Figures 22-29As shown, the preset catheter can be provided as an adjustable bending catheter 78, which comprises an adjustable bending tube 781 and an adjusting member 782. The adjustable bending tube 781 comprises an extension section 7811 and an adjustable bending section 7812, which is arranged at the distal end side of the extension section 7811. The adjustable bending section 7812 can be the part of the adjustable bending tube 781 from the position corresponding to the distal end face of the limiting hole part 783 to the position where the distal end of the adjustable bending tube 781 is connected with the distal end 7821 of the adjusting member 782. The natural axial length of the adjustable bending section 7812 when not being adjusted can be set in the range of 0.5 cm to 10 cm. The adjustable bending catheter 78 further comprises a limiting hole part 783, which is arranged at the proximal end side of the adjustable bending section 7812. The limiting hole part 783 can be located on the tube wall of the adjustable bending tube 781 or outside the tube wall of the adjustable bending tube 781. The adjusting member 782 comprises a distal end 7821 and an adjusting section 7822. The distal end 7821 of the adjusting member 782 is connected with the distal end of the adjustable bending tube 781. The adjusting member 782 passes through the limiting hole part 783 and extends towards the proximal end, so as to form the adjusting section 7822 between the limiting hole part 783 and the distal end 7821. When the adjusting member 782 is pulled back, the distal end of the adjustable bending tube 781 can be bent by the adjusting member 782, so as to adjust the bending of the adjustable bending section 7812. It can be understood that the adjusting member 782 can be provided as a pulling wire extending in the axial direction. The adjusting member 782 extends towards the proximal end to the outside of the operating handle. The proximal end of the adjusting member 782 can be provided with a bending button. When the adjusting member 782 is pulled back by the bending button, the adjusting member 782 moves in the axial direction relative to the adjustable bending tube 781, so as to bend the adjusting section 7822.

[0089] Further, the adjustable bending tube 781 comprises a first lumen 78a. The limiting hole part 783 comprises a lumen structure extending in the axial direction. The distal end of the limiting hole part 783 extends to the proximal end side of the adjustable bending section 7812. In one embodiment, the lumen structure is provided as a second lumen 783a, and the distal end of the second lumen 783a extends to the proximal end side of the adjustable bending section 7812, i.e. the adjustable bending catheter 78 forms a double-lumen tube. The first lumen 78a and the limiting hole part 783 can be provided as not being communicated, so as to avoid affecting the independence and smoothness of the inner wall of the first lumen 78a when the adjusting member 782 extends along the second lumen 783a. Thus, after the adjustable bending section 7812 of the adjustable bending tube 781 is adjusted, it is ensured that the (superfine or superhard) guide wire along the first lumen 78a of the adjustable bending catheter 78 can be selected into the branch blood vessel without any obstacle.

[0090] For example, the limiting hole part 783 is set as a second lumen 783a extending in the axial direction. It can be understood that when the adjusting member 782 does not bend the adjustable bend segment 7812, the adjustable bend tube 781 and the adjusting member 782 are both in a straightened state, and the adjusting segment 7822 of the adjusting member 782 is attached to the outer wall of the adjustable bend segment 7812, as shown in Figure 24 In combination with Figure 26 When the adjusting member 782 is pulled backward on this basis, part of the adjusting segment 7822 enters the second lumen 783a from the distal end of the second lumen 783a, and the distal end of the adjustable bend segment 7812 is bent toward the side connected to the adjusting member 782, so that the part of the adjusting segment 7822 exposed outside the second lumen 783a deviates from the arc formed by the adjustable bend segment 7812, as shown in Figure 25 The adjustable bend tube 781 can be bent to align with the branch blood vessel orifice after the main body support 10 is released, and the bent adjustable bend segment 7812 can be directly selected into the branch blood vessel or the super-fine guide wire can be directly selected into the branch blood vessel by using the adjustable bend tube 78 as a guide, which is not limited herein.

[0091] Further, the second lumen 783a can be set on the tube wall of the adjustable bend tube 781 and extend in the axial direction along the tube wall of the adjustable bend tube 781 in a cavity type hole. The tube wall of the adjustable bend tube 781 can include, from inside to outside, a braided layer 7813 and a polymer layer 7814 in sequence, and the second lumen 783a is set in the polymer layer 7814. Generally, the thickness of the polymer layer 7814 is thickened to slightly exceed the size of the second lumen 783a, and the second lumen 783a can be formed in the polymer layer 7814, as shown in Figure 23 In other embodiments, as shown in Figure 28 The second lumen 783a is located outside the adjustable bend tube 781, the tube wall of the adjustable bend tube 781 can include, from inside to outside, the braided layer 7813 and the polymer layer 7814 in sequence, and the adjustable bend tube 78 further includes an arc-shaped wall 7815 extending in the axial direction and located outside the polymer layer 7814. The arc-shaped wall 7815 and the outer wall of the polymer layer form the second lumen 783a in the axial direction, and the distal end of the arc-shaped wall 7815 extends to the proximal side of the adjustable bend segment 7812. The second lumen 783a is set outside the adjustable bend tube 781, so that the overall outer diameter of the adjustable bend tube 78 is smaller, and in particular, the thickness of the polymer layer 7814 can greatly improve the flexibility of the overall adjustable bend tube 78. In other embodiments, as shown in Figure 29As shown, the limiting hole part 783 comprises a limiting ring, which is arranged outside the adjustable elbow tube 781 and at the proximal end side of the adjustable elbow segment 7812, so as to facilitate the connection between the distal end part 7821 of the adjusting member 782 and the distal end of the adjustable elbow tube 781. The adjusting member 782 passes through the limiting ring and extends towards the proximal end, so as to form the adjusting segment 7822 between the limiting ring and the distal end part 7821.

[0092] The stent system 700 further comprises a superfine guide wire. After the adjustable elbow segment 7812 of the adjustable elbow tube 781 is adjusted, it can be used to guide the superfine guide wire, so as to facilitate the selection of the superfine guide wire into the branch blood vessel. After the superfine guide wire enters the branch blood vessel for a certain length (only to ensure that the adjustable elbow tube 781 does not take the superfine guide wire out of the branch blood vessel after the adjustment is cancelled), the adjustment of the adjustable elbow segment 7812 can be cancelled, so that the adjusting segment 7822 is attached to the outer wall of the adjustable elbow segment 7812 instead of being away from the adjustable elbow segment 7812. The forward pushing of the adjustable elbow tube 781 can make the adjustable elbow tube 781 conform to the superfine guide wire entering the branch blood vessel. After the adjustable elbow tube 781 is selected into the branch blood vessel, the superfine guide wire is withdrawn, and then a superhard guide wire is selected into the branch blood vessel along the adjustable elbow tube 781, so as to use the superhard guide wire selected into the branch blood vessel as a delivery channel for the external small branch. Such a stent system 700 can first select the superfine guide wire into the branch blood vessel by means of the guiding effect of the adjustable elbow segment 7812 during the process of the adjustable elbow tube 781 entering the branch blood vessel, and then guide the adjustable elbow tube 781 by means of the superfine guide wire which has entered the branch blood vessel, so that the adjustable elbow tube 781 can enter the branch blood vessel by relying on the guiding effect of the superfine guide wire without the need for the adjustable elbow segment 7812 to remain adjusted. That is, during the process of the adjustable elbow tube 781 entering the branch blood vessel, the adjusting segment 7822 can be attached to the outer wall of the adjustable elbow segment 7812 instead of being away from the adjustable elbow segment 7812, so as to avoid the possibility of damage to the blood vessel by the adjusting segment 7822.

[0093] In one embodiment, as shown in FIG. 1, the stent system 700 comprises an adjustable elbow tube 781 and an adjusting member 782. The adjustable elbow tube 781 comprises an adjustable elbow segment 7812 and a straight segment 7811. The adjustable elbow segment 7812 is arranged at the distal end of the straight segment 7811. The adjusting member 782 is arranged at the proximal end of the straight segment 7811. The adjusting member 782 comprises a distal end part 7821 and an adjusting segment 7822. The distal end part 7821 is arranged at the distal end of the adjusting member 782. The adjusting segment 7822 is arranged at the proximal end of the adjusting member 782. The distal end part 7821 is connected to the proximal end of the straight segment 7811. The adjusting segment 7822 is arranged outside the adjustable elbow segment 7812. Figures 30-31As shown, when the diameter release member 74 is arranged, due to the loading state of the stent system 700, the distal end of the adjustable bending catheter 78 exceeds the second end 33 of the branch stent 30, and is passed through the gap formed by the diameter release member 74 from the cut seam 791, the diameter release member 74 is arranged to pass through the gap between the adjusting segment 7822 and the adjustable bending segment 7812, and is located between the distal end 7821 of the adjusting member 782 and the limiting hole portion 783. The intersection formed by the distal end 7821 of the adjusting member 782 and the distal end of the adjustable bending tube 781 makes the diameter release member 74 limit the intersection, which facilitates the distal end of the adjustable bending catheter 78 to extend out of the envelope 79 and always have part of the adjustable bending catheter 78, so that the distal end 7821 of the adjustable bending catheter 78 is not brought into the envelope 79 due to the friction of the sheath tube 73 retracting, which is not conducive to the subsequent adjustable bending catheter 78 extending out of the envelope 79 again. The adjustable bending catheter 78 further comprises a limiting buckle 784, which is arranged on the distal side of the limiting hole portion 783 and close to the limiting hole portion 783, so that the adjustable bending segment 7812 and the adjusting member 782 form a limiting hole 785 between the limiting buckle 784 and the distal end of the limiting hole portion 783. The diameter release member 74 can pass through the limiting hole 785, and in combination with the limiting action of the diameter release member 74, the possibility of the adjustable bending catheter 78 retracting in the axial direction can be further reduced, so that the entire adjustable bending segment 7812 remains outside the envelope 79, which facilitates the subsequent adjustment of the bending state.

[0094] In other embodiments, when the diameter release member 74 is not required to be arranged, the envelope 79 comprises a natural unfolding state and a folded wrapping state, the distal end of the adjustable bending catheter 78 is inserted into the distal end of the main stent 10, and is passed out of the branch stent 30, and the distal end of the adjustable bending catheter 78 is wrapped in the first wrapping layer 792 together with the branch stent 30, and the distal end of the adjustable bending catheter 78 at least exceeds the proximal end of the main stent 10, for example, to send the stent system 700 into the aortic arch. The following is a brief overview of the surgical method of the stent system 700 provided in this embodiment (the surgical steps of the stent system in other embodiments are generally consistent):

[0095] First, the stent system 700 is sent to the aortic arch along the guide wire channel, and then the sheath tube 73 is retracted to fold the third wrapping layer 796 from the outside of the second wrapping to the proximal side of the second wrapping layer 794, so that the third wrapping layer 796 and the second wrapping layer 794 are wrapped outside the first wrapping layer 792, and the envelope 79 is in a fully wrapped and semi-restricted state, as shown in Figure 32 In combination with Figures 16-17 As shown;

[0096] Then, the adjustable bend catheter 78 is pushed forward so that the distal end of the adjustable bend catheter 78 is out of the envelope 79, thus exposing the adjustable bend catheter 78 from the envelope 79, and then the adjusting member 782 of the adjustable bend catheter 78 is adjusted so that the adjustable bend segment 7812 is bent to face the branch vessel orifice, a super-fine guide wire is inserted into the lumen of the adjustable bend tube 781, and the super-fine guide wire is introduced into the branch vessel along the adjustable bend catheter 78 to a certain length (to prevent the super-fine guide wire from being pulled out of the branch vessel when the adjustable bend catheter 78 is introduced into the branch vessel later), and then the bending of the adjustable bend segment 7812 is cancelled, the adjustable bend catheter 78 is continuously pushed forward along the super-fine guide wire into the branch vessel, the super-fine guide wire is withdrawn, a super-hard guide wire 83 is inserted into the lumen of the adjustable bend tube 781, and the super-hard guide wire 83 is introduced into the branch vessel along the adjustable bend catheter 78, thus establishing a branch passage, as shown in Figure 33 For the branch vessels that are not extended from the branch orifice in a direction away from the heart, i.e., the branch vessels with a branch angle that is not excessively twisted, the super-fine guide wire can not be used, and after the adjustable bend segment 7812 is bent, the distal end of the adjustable bend catheter 78 is directly inserted into the super-hard guide wire along the lumen of the adjustable bend tube 781, and the super-hard guide wire is introduced into the branch vessel along the adjustable bend catheter 78.

[0097] As shown in Figure 34 the adjustable bend catheter 78 is withdrawn, the sheath tube 73 is continuously withdrawn, so that the envelope 79 is in an intermediate state of half-wrapping, and as shown in Figures 18-18a when the coincident incision 791 is withdrawn to the first connection point at the proximal end of the outer part, the branch stent 30 is exposed from the envelope 79, at this time, due to the radial constraint of the envelope 79 on the first bare coil 20 in combination with the post-release structure, the proximal end of the main body stent 10 is not much expanded, the stent system 700 can be continuously fine-tuned, the super-hard guide wire is used to make the branch stent 30 adhere to the branch vessel orifice, and the sheath tube 73 is further withdrawn, so that the envelope 79 is gradually removed from the main body stent 10, thus making the main body stent 10 be completely released, as shown in Figure 35 .

[0098] Finally, the outer sheath core 712 is withdrawn, the post-release structure is removed, the first bare coil 20 is adhered to the wall, and the delivery device 70 is withdrawn, thus taking the envelope 79 out of the patient's body.

[0099] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as within the scope of the present disclosure.

[0100] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A support system, characterized in that, The stent system includes a covered stent and a delivery device. The delivery device includes a sheath. The covered stent includes a main stent and a branch stent. The branch stent is disposed on one side of the main stent. The main stent includes a main corrugated coil and a main covering. The main covering covers the main corrugated coil. The delivery device includes a semi-binding structure. The semi-binding structure includes a membrane and a detachable member. The membrane can release the main stent by means of the detachable member to compress or release the main stent radially. The membrane includes a slit. The membrane has two rows of opposite perforations along the axial edge of the slit. In the delivery state, the detachable member passes through the perforations to compress the membrane radially against the main stent. The slit extends proximally past the branch stent, allowing the branch stent to protrude from the membrane. One end of the membrane is connected to the distal end or distal inner surface of the sheath. The membrane includes a naturally unfolded state and a folded wrapped state. In the folded wrapped state, the membrane includes a first wrapping layer, a first fold, a second wrapping layer, a second fold, a third wrapping layer, and a circumferential connection. The membrane forms the first wrapping layer from the first fold towards the proximal end, and the covered support is wrapped within the first wrapping layer. The membrane is folded outward from the distal end towards the proximal end in the naturally unfolded state along the first fold, thereby forming the second wrapping layer on the outside of the first wrapping layer. Based on this, the membrane continues to be folded towards the distal end along the second fold, thereby forming the third wrapping layer on the outside of the second wrapping layer. In the folded wrapped state, the slit on the second wrapping layer extends from the first fold towards the proximal end beyond the branch support, and the slit forms an opening towards the distal end at the partial overlap of the first and second wrapping layers.

2. The support system according to claim 1, characterized in that, The distal end of the detachable member is sequentially sewn or passed through the perforation.

3. The support system according to claim 1, characterized in that, The delivery device also includes a pre-placed conduit, the distal end of which enters from the distal end of the main support and exits from the branch support.

4. The support system according to claim 3, characterized in that, The pre-installed conduit is configured as an adjustable bend conduit, which includes an adjustable bend and an adjusting member. The adjustable bend includes an extension section and an adjustable bend section, with the adjustable bend section located at the distal end of the extension section. The adjustable bend conduit also includes a limiting hole located at the proximal end of the adjustable bend section. The adjusting member includes a distal end and an adjusting section. The distal end of the adjusting member is connected to the distal end of the adjustable bend conduit. The adjusting member passes through the limiting hole and extends towards the proximal end, thereby forming the adjusting section between the limiting hole and the distal end.

5. The support system according to claim 4, characterized in that, The semi-binding structure also includes a detachable beam diameter member, which cooperates with the membrane to achieve radial constriction and release of the covered support. The detachable beam diameter member passes through the gap between the adjustment section and the adjustable bending section.

6. The support system according to claim 1, characterized in that, The conveying device includes a sheath core assembly and a support rod. The sheath core assembly includes an inner sheath core and an outer sheath core. The inner sheath core, the outer sheath core, the support rod, and the sheath tube are sequentially sleeved from the inside to the outside, and each pair of the inner sheath core, the outer sheath core, and the sheath tube can move relative to each other along the axial direction. The film-coated support also includes a first bare wave coil. The support system includes a rear-release structure. The distal end of the outer sheath core and the proximal end of the guide head of the conveying device form a rear-release structure. The rear-release structure is used to hook the first bare wave coil, thereby realizing the rear release of the first bare wave coil.

7. The support system according to claim 1, characterized in that, The proximal end of the cut does not penetrate the proximal end of the first wrapping layer.

8. The support system according to claim 7, characterized in that, Let L1 be the axial length of the membrane in its naturally unfolded state, and L2 be the axial length of the main body covering. Then L1 and L2 satisfy: L1 > 2L2.

9. The support system according to claim 8, characterized in that, The axial length from the first fold to the proximal end face of the membrane is defined as L3, where L3 and L2 satisfy the following condition: L3≥L2.

10. The support system according to claim 8, characterized in that, The covered support includes a first connection point, which is the connection point located at the farthest end of the main support when the branch support is circumferentially connected to the main support. The axial length from the first connection point to the proximal end face of the main cover is defined as L5. When the cover is in the folded wrapping state, the axial length of the slit is defined as L4. L4 and L5 satisfy the following condition: L4≥L5.

11. The support system according to claim 1, characterized in that, The stent system also includes a traction wire, the distal end of which is connected to the proximal side of the first wrapping layer.

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