Ascending aorta covered stent and delivery system assembly and method of use thereof

Abstract

The present invention discloses an ascending aorta covered stent and delivery system component and a method of using the same, which belongs to the field of minimally invasive surgery technology and is designed to solve the problem that it is difficult to use minimally invasive surgery in the treatment of the ascending aorta in the prior art. The ascending aorta covered stent and delivery system component of the present invention include a stent conveyor and a covered stent, the stent conveyor includes an outer sheath, an adjustable bend, a single-lumen middle tube, a single-lumen tube, a flexible TIP head, a chronic dilator and an adjustment handle; the covered stent includes a proximal bare crown stent and a distal covered stent connected. The ascending aorta covered stent and delivery system component of the present invention and a method of using the same solve the problem that ascending aorta dissection is not suitable for minimally invasive surgery, reduce the mortality rate and complication rate during surgery, and require shorter hospitalization and postoperative monitoring time. The outer sheath has sufficient axial and radial support and compliance.

Description

Technical Field

[0001] The present invention relates to the technical field of minimally invasive surgery, and in particular to an ascending aorta covered stent and a delivery system component and a use method thereof. Background Art

[0002] When the aorta is pathologically dilated and exceeds 50% of the normal blood vessel diameter, it is called an aortic aneurysm. Aortic aneurysms located in the ascending aorta often involve the aortic sinus, causing deformation of the aortic valve ring and separation of the valve leaflets, leading to aortic valve insufficiency, and long-term effects causing heart failure. According to the different distribution of aortic lesions, aortic dissection can be divided into the following three types according to the DeBakey system: Type I dissection originates from the ascending aorta, extends beyond the aortic arch to the descending aorta, and even the abdominal aorta. This type is the most common. Type II dissection originates from and is limited to the ascending aorta. DeBakey types I and II can also be equated with Stanford type A.

[0003] Among them, Stanford A type dissection involving the ascending aorta is one of the most dangerous vascular diseases with a high mortality rate. Aortic dissection is a rupture in the middle layer of the aortic wall, and there is flowing or coagulated blood at the rupture. The rupture of the middle layer is usually at the interface between the inner 1 / 3 and the outer 2 / 3 of the middle layer. The dissection divides the complete aortic wall structure into two: a part of the aortic wall composed of the inner 1 / 3 of the middle layer of the aortic wall intima and the other part of the aortic wall composed of the outer 2 / 3 of the middle layer and the adventitia. The former is called the inner wall of the dissection, and the latter is called the outer wall of the dissection. The rupture gap between the inner and outer walls of the dissection is the dissection cavity. Aortic dissections with proximal ruptures in the ascending aorta account for 65% of all aortic dissections, those in the aortic arch account for 5%, and those in the descending aorta account for about 30%.

[0004] Currently, only open surgical treatment is available, such as open-chest artificial blood vessel replacement, such as Bentall surgery (using polyester blood vessel replacement with artificial aortic valve and reimplanting the coronary artery into the polyester blood vessel), Wheat surgery, etc. Open surgical treatment requires cardiac arrest and extracorporeal circulation, which is extremely traumatic and has high mortality and complication rates.

[0005] Due to the complex anatomical structure of the ascending aorta, with the heart, valves, and coronary arteries at the anterior proximal end and the supra-aortic branch arteries that supply blood to the brain and upper limbs at the posterior end, coupled with the high blood pressure and rapid flow rate of the ascending aorta, large vascular wall pulsation and deformation, and the severity of ascending aortic dissection, it is difficult to accurately position the stent in an extremely limited area. The anchoring of the stent must not only overcome the pulsation and deformation of the vascular wall, but also prevent backward displacement or even tearing of the dissection, and avoid extending the stent forward into the sinus to prevent damage to the valve and blockage of the coronary artery, resulting in the difficulty of applying intravascular minimally invasive technology to the treatment of the ascending aorta. Summary of the invention

[0006] One object of the present invention is to provide an ascending aortic covered stent and a delivery system assembly, which can be used for minimally invasive surgery on ascending aortic dissection.

[0007] Another object of the present invention is to provide a method for using an ascending aortic stent graft and a delivery system assembly that can be used for minimally invasive surgery on ascending aortic dissection.

[0008] To achieve this object, on the one hand, the present invention adopts the following technical solutions:

[0009] An ascending aorta covered stent and delivery system component, including a stent delivery device and a covered stent, the stent delivery device including an outer sheath, an adjustable bend, a single-lumen middle tube, a single-lumen tube, a flexible TIP head, a chronic dilator and an adjustment handle, one end of the chronic dilator is connected to the head end of the single-lumen middle tube and the other end is connected to the single-lumen tube, the single-lumen tube is inserted into the single-lumen middle tube, the end of the single-lumen middle tube and the end of the outer sheath are respectively connected to the adjustment handle; the adjustment handle includes an outer sheath moving speed control unit, a bend direction adjustment unit, a bare crown stent release unit, a distal end A coated stent release unit, a front cleaning port, a rear cleaning port and a handle; the coated stent includes a proximal bare crown stent and a distal coated stent that are connected to each other; the distal coated stent includes a plurality of annular support single rings, a cylindrical film and a reinforcement ring, all of the support single rings are evenly arranged axially on the outer wall of the cylindrical film, and the reinforcement ring is fixed on the inner wall of the end of the cylindrical film; a front barb and a rear barb are provided on the proximal bare crown stent, the front barb is at the proximal end position relative to the rear barb, the tip of the front barb faces the distal end, and the tip of the rear barb faces the proximal end.

[0010] In particular, the outer sheath tube movement speed control unit includes an outer sheath tube retraction knob and a sleeve, a spiral piece, a retraction knob handle, a quick release switch and a V-shaped elastic steel sheet arranged in the outer sheath tube retraction knob. The end of the outer sheath tube is fixedly connected to the sleeve, and the sleeve is inserted into the retraction knob handle. One end of the spiral piece is connected to the V-shaped elastic steel sheet and the other end abuts against the quick release switch. The quick release switch is configured to control the engagement and disengagement of the spiral piece and the external thread of the handle.

[0011] In particular, the adjustable bend includes a bendable section, a transition connection rod and a rear tough multi-lumen tube connected in sequence, and the end of the rear tough multi-lumen tube is fixedly connected to the adjustment handle; a plurality of traction wires are passed through the adjustable bend, and the head ends of all the traction wires are respectively fixedly connected to different positions at the front end of the bendable section, and the tail ends of all the traction wires respectively pass through different azimuth holes of the transition connection rod and the rear tough multi-lumen tube and are connected to the steering assembly on the adjustment handle.

[0012] In particular, the steering assembly includes a plurality of bending adjustment sliders, the adjustment handle includes an adjustable bending knob in the X-axis direction and an adjustable bending knob in the Y-axis direction, and the plurality of bending adjustment sliders are respectively connected to the adjustable bending knob in the X-axis direction or the adjustable bending knob in the Y-axis direction; and / or, the steering assembly includes two rotating hand wheels, two spur gears and four racks, each of the rotating hand wheels is connected to a spur gear, the two racks are respectively meshed with a spur gear from opposite sides, and the racks are respectively connected to the tail of the traction wire.

[0013] In particular, the bare crown stent release unit includes a chronic dilator release knob and a bare crown stent release switch, the end of the single-lumen middle tube is connected to an externally threaded slider, the externally threaded slider is connected to the chronic dilator release knob, and the chronic dilator release knob is configured to control the expansion and contraction of the chronic dilator; the proximal bare crown stent is tied to the chronic dilator by an elastic rope buckle, and one end of the elastic rope buckle is connected to the bare crown stent release switch.

[0014] In particular, the bare crown stent release unit includes a chronic expander release knob, a retention restraining wire that is inserted into the proximal bare crown stent for a circle, a double-strand traction wire, and a fixed pin arranged on the single-lumen inner middle tube, and the double-strand traction wire is wrapped around the retention restraining wire; the front end of the double-strand traction wire is connected to the fixed pin, the end of the double-strand traction wire is connected to the external thread slider, and the external thread slider is connected to the chronic expander release knob, and the chronic expander release knob is configured to drive the retention restraining wire to tighten or relax through the double-strand traction wire, thereby forcing the proximal bare crown stent to compress or expand.

[0015] In particular, the distal end coated stent release unit includes a coated segment release switch, the distal end coated stent is restrained on the adjustable bend by a soft film, a draw wire is passed through the soft film, the front end of the draw wire is connected to the flexible TIP head, and the rear end of the draw wire is connected to the coated segment release switch, and the coated segment release switch is configured to release the distal end coated stent by pulling out the draw wire.

[0016] In particular, the outer sheath comprises a three-layer structure arranged sequentially from the inside to the outside, the inner side is made of PTFE material, the middle layer is made of metal wire or braided mesh, and the outer layer is made of PEBAX, PU or PTFE material.

[0017] Particularly, the cylindrical film is made of a biocompatible film material.

[0018] In particular, the inclination angles of the front barb and the rear barb are both between 30° and 45°.

[0019] In particular, a metal protective sleeve is provided on the inner side of the outer sheath tube, and the proximal bare crown stent is at least partially located in the metal protective sleeve when it is in a contracted state.

[0020] In particular, the reinforcement ring is rhombus-shaped; or, the single support ring and the reinforcement ring are respectively sinusoidal, the width of the reinforcement ring is smaller than the width of the single support ring and the number of wave heads of the reinforcement ring is greater than the number of wave heads of the single support ring.

[0021] On the other hand, the present invention adopts the following technical solutions:

[0022] A method for using an ascending aorta covered stent and a delivery system assembly, comprising the following steps:

[0023] Step 1: Push the flexible TIP head along the blood vessel until it reaches the set position;

[0024] Step 2: After the stent graft reaches the target lesion, the outer sheath is removed to expose the semi-expanded stent graft; the single-lumen inner tube and the single-lumen middle tube are pushed forward as a whole to expose the proximal bare crown stent;

[0025] Step 3, withdrawing the single-lumen inner tube and the single-lumen middle tube until the chronic dilator is aligned with the proximal bare-crown stent; withdrawing the single-lumen inner tube alone to allow the chronic dilator to expand radially, and the constrained proximal bare-crown stent gradually expands with the expansion of the chronic dilator;

[0026] Step 4, adjusting the angle of the proximal bare crown stent during the process of expanding the chronic dilator until the proximal bare crown stent fits the inner wall of the target diseased blood vessel;

[0027] Step 5: First completely release the distal covered stent, and then push the single-lumen inner tube forward alone to separate the chronic dilator from the proximal bare-crown stent, thereby completing the release and angle adjustment of the proximal bare-crown stent.

[0028] The stent conveyor of the ascending aorta covered stent and the delivery system assembly of the present invention can deliver the covered stent used to isolate the target diseased blood vessel to a designated position, perform ascending aorta intraluminal isolation, solve the problem that ascending aortic dissection is not suitable for minimally invasive surgery, reduce the mortality rate and complication rate during surgery, and shorten the required hospitalization and postoperative monitoring time. The outer sheath has sufficient axial and radial support and compliance, and the adjustable bend can travel in a blood vessel with severe distortion and a small growth angle to adapt to the tortuosity of the human vascular system, and realize the long-distance delivery and operation of the covered stent. The setting of the front barb and the rear barb makes the proximal bare crown stent anchored more firmly in a very limited area, which is enough to resist the unfavorable conditions such as high blood pressure and high blood flow velocity, and ensures that the release position and release angle of the whole covered stent are sufficiently accurate, and the wall adhesion is better, so as to avoid the formation of internal leakage or displacement, and not interfere with the aortic valve and the coronary entrance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the ascending aorta covered stent and delivery system assembly provided by a specific embodiment of the present invention;

[0030] Figure 2 is a schematic structural diagram of a stent conveyor provided in a specific embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of the internal structure of a stent conveyor provided in a specific embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the structure of the stent delivery device provided by a specific embodiment of the present invention after the outer sheath is withdrawn;

[0033] Figure 5 is a schematic diagram of the structure of a chronic expander of a stent delivery device after expansion provided by a specific embodiment of the present invention;

[0034] Figure 6 It is a schematic structural diagram of a proximal bare crown stent provided in a specific embodiment of the present invention;

[0035] Figure 7 is a schematic structural diagram of a stent graft provided in a specific embodiment of the present invention;

[0036] Figure 8 It is a structural schematic diagram of an adjustable elbow provided in a specific embodiment of the present invention;

[0037] Fig. 9 It is a structural schematic diagram of a transition connection top rod provided in a specific embodiment of the present invention;

[0038] Fig.10 is a schematic diagram of another preferred structure of a steering assembly provided in a specific embodiment of the present invention;

[0039] Fig.11 It is a schematic diagram of the structure of the distal end stent graft in a semi-released state provided by a specific embodiment of the present invention;

[0040] Fig.12 It is a schematic diagram of the structure of the distal end stent graft provided by a specific embodiment of the present invention in a released state;

[0041] Fig.13 Schematic diagram of the winding method of the elastic cord buckle provided in a specific embodiment of the present invention;

[0042] Fig.14 and Fig.15 They are schematic diagrams of the structure of the proximal bare crown stent in a constrained state provided by a specific embodiment of the present invention;

[0043] Figures 16 to 20 They are schematic diagrams of the process of delivering the coated stent by the stent conveyor.

[0044] In the figure:

[0045] 100, stent delivery device; 110, outer sheath; 111, metal protective sleeve; 120, adjustable bend; 121, bendable segment; 122, rear tough multi-lumen tube; 123, traction wire; 124, bend adjustment slider; 125, transition connection top rod; 130, single-lumen middle tube; 140, single-lumen tube; 150, flexible TIP head; 160, chronic dilator; 171, outer sheath withdrawal knob; 172, X-axis adjustable bend knob; 173, Y-axis adjustable bend knob; 174, chronic dilator release knob; 175, coated segment release switch; 176, bare crown stent release switch; 177, front cleaning port; 178, rear cleaning port; 1 79. Handle; 180. Elastic cord buckle; 190. Soft film; 191. Wire drawing; 200. Covered stent; 210. Proximal bare crown stent; 211. Front barb; 212. Rear barb; 220. Distal covered stent; 221. Support single ring; 222. Cylindrical film; 223. Reinforcement ring; 224. Skirt; 401. Handwheel; 402. Spur gear; 403. Rack; 501. Retaining binding wire; 502. Double-strand traction wire; 503. Fixing pin; 1251. Azimuth hole; 1711. Sleeve; 1712. Spiral sheet; 1713. Retraction knob handle; 1714. Quick release switch; 1715. V-shaped elastic steel sheet. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0047] This embodiment discloses an ascending aorta covered stent and a delivery system assembly, such as Figure 1As shown, the assembly includes a stent delivery device 100 and a stent graft 200. Figures 2 to 5 As shown, the stent delivery device 100 includes an outer sheath 110, an adjustable bend 120, a single-lumen middle tube 130, a single-lumen inner tube 140, a flexible TIP head 150, a chronic dilator 160 and an adjustment handle, one end of the chronic dilator 160 is connected to the head end of the single-lumen middle tube 130 and the other end is connected to the single-lumen inner tube 140, the single-lumen inner tube 140 is inserted into the single-lumen middle tube 130, and the end of the single-lumen middle tube 130 and the end of the outer sheath 110 are respectively connected to the adjustment handle; the adjustment handle includes an outer sheath moving speed control unit, a bend direction adjustment unit, a bare crown stent release unit, a distal end coated stent release unit, a front cleaning port 177, a rear cleaning port 178 and a handle 179. Among them, the chronic expander 160 has a function similar to balloon expansion, which improves the wall adhesion of the coated stent 200, shortens the balloon expansion time, and ensures that the anchored coated stent 200 will not shift, thus solving the problems of slow aortic blood flow and reflux caused by long-term balloon expansion.

[0048] like Figure 6 and Figure 7 As shown, the stent graft 200 includes a proximal bare crown stent 210 and a distal stent graft 220 connected to each other. The distal stent graft 220 includes a plurality of annular support single rings 221, a cylindrical film 222 and a reinforcing ring 223, all of the support single rings 221 are evenly arranged on the outer wall of the cylindrical film 222 along the axial direction, and the reinforcing ring 223 is fixed on the inner wall of the end of the cylindrical film 222.

[0049] The distal end covered stent 220 is preferably made of nickel-titanium wire; the support single ring 221 is preferably formed of a sinusoidal (or wavy) nickel-titanium wire to form a ring structure. The proximal end bare crown stent 210 is preferably made of nickel-titanium alloy material by laser engraving into a plurality of diamond structures connected in sequence, all of which are wound into a circle. The evenly arranged diamond structures have a certain radial force while reducing the stimulation to the inner wall of the blood vessel, and the inner wall of the blood vessel is evenly stressed.

[0050] A front barb 211 and a rear barb 212 are provided on the proximal bare crown stent 210. The front barb 211 is located at the proximal end relative to the rear barb 212, the tip of the front barb 211 faces the distal end, and the tip of the rear barb 212 faces the proximal end. The inclination angles of the front barb 211 and the rear barb 212 relative to the surface of the proximal bare crown stent 210 body are 30°-45°. After the proximal bare crown stent 210 is released, the front barb 211 and the rear barb 212 are slowly pressed into the inner wall of the blood vessel by using the "ball expansion" function of the chronic dilator 160, so that the proximal bare crown stent 210 can be more firmly and reliably anchored at the set position, reducing the risk of displacement of the proximal bare crown stent 210; the front barb 211 and the rear barb 212 are small in area and have little effect on the aortic blood flow. The arrangement of the barbs and the sinusoidal (or wavy) shape of the supporting single ring 221 improve the sealing performance of the head end of the proximal bare crown stent 210 .

[0051] The proximal bare crown stent 210 consists of a proximal end and a distal end. The proximal end is in the shape of a trumpet with an outward expansion angle of 10°-30°; the distal end is in the shape of a straight cylinder and is fixedly connected to the inner wall of the head end of the cylindrical film 222. The outer side of the distal end has a skirt 224, which is inclined toward the proximal end.

[0052] The stent delivery device 100 of the ascending aorta covered stent and delivery system assembly can deliver the covered stent 200 used to isolate the target diseased blood vessel to a designated location, perform ascending aorta intraluminal isolation, and treat ascending aortic dissection or aneurysm, and is particularly suitable for treating type A aortic dissection and ascending aortic aneurysm, solving the problem that ascending aortic dissection is not suitable for minimally invasive surgery, reducing the mortality rate and complication rate during surgery, and shortening the required hospitalization and postoperative monitoring time. The outer sheath 110 has sufficient axial and radial support and compliance, and the adjustable bend 120 can travel in a severely twisted blood vessel with a small growth angle to adapt to the tortuosity of the human vascular system, and realize the long-distance delivery and operation of the covered stent 200. The provision of the front barb 211 and the rear barb 212 allows the proximal bare crown stent 210 to be anchored more firmly in a very limited area, sufficient to withstand adverse conditions such as high blood pressure and high blood flow velocity, and ensure that the overall release position and release angle of the coated stent 200 are sufficiently precise, with better wall adhesion, avoiding the formation of internal leakage or displacement, and not interfering with the aortic valve and the coronary artery entrance.

[0053] On the basis of the above structure, the outer sheath tube moving speed control unit includes an outer sheath tube retraction knob 171 and a sleeve 1711, a spiral piece 1712, a retraction knob handle 1713, a quick release switch 1714 and a V-shaped elastic steel sheet 1715 arranged in the outer sheath tube retraction knob 171. The end of the outer sheath tube 110 is fixedly connected to the sleeve 1711, the sleeve 1711 is inserted into the retraction knob handle 1713, one end of the spiral piece 1712 is connected to the V-shaped elastic steel sheet 1715, and the other end is abutted against the quick release switch 1714. Pressing or releasing the quick release switch 1714 can control the clutch of the spiral piece 1712 and the external thread of the handle 179, so as to realize the control of the axial movement speed of the outer sheath tube 110. Specifically, by releasing the quick release switch 1714 and rotating the retract knob handle 1713, the outer sheath tube 110 can be slowly moved axially; by pressing the quick release switch 1714 and rotating the retract knob handle 1713, the outer sheath tube 110 can be quickly moved axially.

[0054] The target lesion vessel sometimes grows at an abnormally twisted angle, so the stent delivery device 100 needs to use an adjustable bending function during the delivery of the coated stent 200, such as Figure 8 and Fig. 9 As shown, the adjustable elbow 120 includes a bendable section 121, a transition connecting rod 125 and a rear tough multi-lumen tube 122 connected in sequence, and the end of the rear tough multi-lumen tube 122 is fixedly connected to the adjustment handle; a plurality of traction wires 123 are inserted into the adjustable elbow 120. The head ends of all traction wires 123 are respectively fixedly connected to different positions at the front end of the bendable section 121; the tails of all traction wires 123 pass through different azimuth holes 1251 of the transition connecting rod 125 and the rear tough multi-lumen tube 122, and are connected to the steering assembly on the adjustment handle. Among them, the traction wires 123 are preferably four, and four circular azimuth holes 1251 are symmetrically arranged in the transition connecting rod 125. The bendable section 121 is preferably laser engraved by a metal tube and can be bent in the radial direction; the bendable section 121 can also be a multi-lumen tube with a front section hardness less than a rear section hardness. The built-in traction wire 123 can avoid cutting the inner wall of the blood vessel, and is safer to use.

[0055] The specific structure of the steering assembly is not limited, as long as the bendable section 121 can be turned by pulling the corresponding traction wire 123. Preferably, the steering assembly may include a plurality of bending sliders 124, the adjustment handle includes an adjustable bending knob 172 in the X-axis direction and an adjustable bending knob 173 in the Y-axis direction, and the plurality of bending sliders 124 are respectively connected to the adjustable bending knob 172 in the X-axis direction or the adjustable bending knob 173 in the Y-axis direction. Among them, the X / Y axis direction uses the cross section of the blood vessel as a reference plane, and a vertical coordinate system is formed in the reference plane. Preferably, four bending sliders 124 are provided, and the tail of each traction wire 123 is connected to a bending slider 124. Among the four bending sliders 124, two are left-handed external threads, and the other two are right-handed external threads, and the adjustable bending knob 172 in the X-axis direction and the adjustable bending knob 173 in the Y-axis direction both have left-handed and right-handed internal threads. By rotating the adjustable bending knob 172 in the X-axis direction and the adjustable bending knob 173 in the Y-axis direction to pull the four traction wires 123, any bending direction and angle of the bendable section 121 can be achieved, and the proximal bare crown stent 210 can be turned within a range of 360°.

[0056] like Fig.10 As shown, another preferred structure of the steering assembly is: comprising two rotating hand wheels 401, two spur gears 402 and four racks 403, each rotating hand wheel 401 is connected to a spur gear 402, two racks 403 are respectively engaged with a spur gear 402 from opposite sides, and each rack 403 is respectively connected to the tail of a traction wire 123. The spur gear 402 can be driven to rotate by rotating the hand wheel 401, thereby driving the rack 403 to move, and the softer section of the head end of the multi-lumen tube is pulled to bend by the traction wire 123.

[0057] Based on the above structure, Figures 11 to 13 As shown, the bare crown stent release unit includes a chronic dilator release knob 174 and a bare crown stent release switch 176. The end of the single-lumen middle tube 130 is connected to the external threaded slider 301, and the external threaded slider 301 is connected to the chronic dilator release knob 174. The chronic dilator release knob 174 is configured to control the expansion and contraction of the chronic dilator 160.

[0058] The proximal bare crown stent 210 is tied to the chronic dilator 160 by the elastic cord 180. As the chronic dilator 160 expands, the proximal bare crown stent 210 is slowly released; after the elastic cord 180 is removed, the proximal bare crown stent 210 is completely released. After the proximal bare crown stent 210 is completely released, the chronic dilator 160 can still be used to perform a similar "balloon back dilation" action on the proximal bare crown stent 210.

[0059] The bundling method of the elastic cord buckle 180 is preferably as follows Fig.13As shown, the proximal bare crown stent 210 is folded and sleeved on the outer wall of the chronic dilator 160, and the elastic cord 180 ties together each node of the proximal bare crown stent 210. One end of the elastic cord 180 is free, and the other end is connected to the bare crown stent release switch 176. After the proximal bare crown stent 210 is positioned, the distal coated stent 220 is first completely released, and then the bare crown stent release switch 176 is extracted to complete the complete release of the proximal bare crown stent 210.

[0060] like Figure 2 , Figure 3 , Fig.14 and Fig.15 As shown, the bare crown stent release unit can also be another structure, specifically, including a chronic dilator release knob 174, a retention binding wire 501 that penetrates into the proximal bare crown stent 210, a double-strand traction wire 502, and a fixed pin 503 arranged on the single-lumen middle tube 130, the double-strand traction wire 502 is wound around the retention binding wire 501; the front end of the double-strand traction wire 502 is connected to the fixed pin 503, the end of the double-strand traction wire 502 is connected to the external thread slider 301, the external thread slider 301 is connected to the chronic dilator release knob 174, and the chronic dilator release knob 174 is configured to drive the retention binding wire 501 to tighten or relax through the double-strand traction wire 502, and use the retention binding wire 501 to force the proximal bare crown stent 210 to compress or expand. Wherein, the double-strand traction wire 502 is made of smooth metal wire or polymer wire.

[0061] like Figure 2 and Fig.11 As shown, the distal end stent graft release unit includes a graft segment release switch 175, and the distal end stent graft 220 is restrained on the adjustable elbow 120 by the soft film 190. The soft film 190 is preferably a rectangular sheet structure with a width of 5mm-10mm, and channels are formed at both ends of the soft film 190. A wire drawing 191 is passed through the soft film 190, the front end of the wire drawing 191 is connected to the flexible TIP head 150, and the rear end of the wire drawing 191 is connected to the graft segment release switch 175, and the graft segment release switch 175 is configured to release the distal end stent graft 220 by pulling out the wire drawing 191. The center line of the soft film 190 is fixedly connected to the distal end stent graft 220, and when the wire drawing 191 is pulled out, the distal end stent graft 220 is completely released in sequence from the proximal end to the distal end.

[0062] Based on the above structure, the outer sheath 110 preferably includes a three-layer structure arranged from the inside to the outside, the inner side is made of a smooth PTFE material, the middle layer is made of metal wire or braided mesh, and the outer layer is made of PEBAX, PU or PTFE material. It has good compliance and has sufficient support, bending resistance and smooth inner and outer surfaces in both radial and axial directions.

[0063] The cylindrical film 222 is preferably made of a biocompatible film material. Specifically, the biocompatible film material is preferably polyester or ePTFE.

[0064] On the basis of the above structure, a 10mm-15mm long metal protective sleeve 111 is passed through the inner side of the outer sheath 110. When the proximal bare crown stent 210 is in a contracted state, it is at least partially located in the metal protective sleeve 111, so as to avoid damaging the inner wall of the outer sheath 110 when the proximal bare crown stent 210 is contracted in the outer sheath 110.

[0065] The reinforcing ring 223 is annular as a whole, but the shape of the reinforcing ring 223 in the radial direction is not limited. The reinforcing ring 223 can be rhombus-shaped, which has higher strength; the reinforcing ring 223 can also be sinusoidal like the supporting single ring 221, the width of the reinforcing ring 223 is smaller than the width of the supporting single ring 221, and the number of wave heads of the reinforcing ring 223 is greater than the number of wave heads of the supporting single ring 221, which is more convenient to process.

[0066] The method of using the ascending aorta stent graft and delivery system assembly is as follows:

[0067] Step 1: Build a channel, such as Fig.16 and Fig.17 As shown, the flexible TIP head 150 is pushed along the blood vessel until it reaches the set position. Considering that the stent delivery device 100 made of a four-layer structure is relatively hard, the outer sheath 110 can be removed first at a position with a large turn, and the stent graft 200 can be delivered to the target lesion position using the adjustable bend 120.

[0068] Step 2: After the stent graft 200 reaches the target lesion location, Fig.18 and Fig.19 As shown, the outer sheath 110 is removed to expose the semi-expanded coated stent 200; the single-lumen inner tube 140 and the single-lumen inner middle tube 130 are pushed forward as a whole to expose the proximal bare crown stent 210.

[0069] Step 3, withdraw the single-lumen inner tube 140 and the single-lumen middle tube 130 until the chronic dilator 160 is aligned with the proximal bare-crown stent 210; after adjusting the release angle, withdraw the single-lumen inner tube 140 alone to allow the chronic dilator 160 to expand radially, and the constrained proximal bare-crown stent 210 gradually expands with the expansion of the chronic dilator 160.

[0070] Step 4: Adjust the angle of the proximal bare crown stent 210 during the expansion of the chronic dilator 160 until the proximal bare crown stent 210 fits the inner wall of the target diseased blood vessel. That is, during the release of the proximal bare crown stent 210, the angle of the proximal bare crown stent 210 can be adjusted at any time as needed.

[0071] Step 5: Fig. 20 As shown, first remove the draw wire 191 to completely release the distal coated stent 220; then push the single-lumen inner tube 140 forward alone to slowly contract the chronic dilator 160 until the chronic dilator 160 is completely separated from the proximal bare crown stent 210, completing the release and angle adjustment of the proximal bare crown stent 210.

[0072] In the method of use, the distal end covered stent 220 and the proximal end bare crown stent 210 are released successively. By setting the adjustable elbow 120 and the chronic dilator 160, the proximal end bare crown stent 210 can adjust the release angle while slowly releasing, ensuring that the proximal end bare crown stent 210 can be more accurately anchored at the target position, even if the target position is extremely limited, thereby achieving minimally invasive surgery in the ascending aorta diseased blood vessels with abnormally complex physiological and anatomical structures and extremely high criticality.

[0073] In the prior art, when the covered stent is released, its proximal end is released first, and the distal end is contracted. At this time, the covered stent is like a "pocket", which is prone to form a "storm" effect, causing the impact of blood flow on the covered stent to become greater. In severe cases, the proximal end of the covered stent is easily displaced, and even stimulates the inner wall of the blood vessel to cause dissection rupture, making the covered stent unsuitable for the current ascending aorta with an abnormally complex physiological and anatomical structure.

[0074] The ascending aorta covered stent and delivery system assembly can release the distal end covered stent 220 and the proximal end bare crown stent 210 in steps. After the outer sheath 110 is removed, the distal end covered stent 220 constrained by the soft membrane 190 or the binding wire with a diameter of 10mm-15mm is half-released, which enhances the flexibility and reduces the "storm" effect, further improving the safety and feasibility of minimally invasive surgery.

[0075] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An ascending aorta stent graft and delivery system assembly, comprising a stent delivery device (100) and a stent graft (200), characterized in that: The stent delivery device (100) comprises an outer sheath tube (110), an adjustable bend tube (120), a single-lumen middle tube (130), a single-lumen inner tube (140), a flexible TIP head (150), a chronic dilator (160) and an adjustment handle, wherein one end of the chronic dilator (160) is connected to the head end of the single-lumen middle tube (130) and the other end is connected to the single-lumen inner tube (140), the single-lumen inner tube (140) is inserted into the single-lumen middle tube (130), and the end of the single-lumen middle tube (130) and the end of the outer sheath tube (110) are respectively connected to the adjustment handle; the adjustment handle comprises an outer sheath tube moving speed control unit, a bend tube direction adjustment unit, a bare crown stent release unit, a distal end coated stent release unit, a front cleaning port (177), a rear cleaning port (178) and a grip (179); The coated stent (200) comprises a proximal bare crown stent (210) and a distal coated stent (220) connected to each other; the distal coated stent (220) comprises a plurality of annular support single rings (221), a cylindrical film (222) and a reinforcing ring (223), all of the support single rings (221) are evenly arranged on the outer wall of the cylindrical film (222) along the axial direction, and the reinforcing ring (223) is fixed on the inner wall of the end of the cylindrical film (222); A front barb (211) and a rear barb (212) are provided on the proximal bare crown stent (210), wherein the front barb (211) is located at the proximal end relative to the rear barb (212), the tip of the front barb (211) faces the distal end, and the tip of the rear barb (212) faces the proximal end; The outer sheath tube moving speed control unit comprises an outer sheath tube retraction knob (171), and a tube sleeve (1711), a spiral piece (1712), a retraction knob handle (1713), a quick release switch (1714), and a V-shaped elastic steel sheet (1715) arranged in the outer sheath tube retraction knob (171); the end of the outer sheath tube (110) is fixedly connected to the tube sleeve (1711); the tube sleeve (1711) is inserted into the retraction knob handle (1713); one end of the spiral piece (1712) is connected to the V-shaped elastic steel sheet (1715) and the other end abuts against the quick release switch (1714); the quick release switch (1714) is configured to control the engagement and disengagement of the spiral piece (1712) and the external thread of the handle (179); The bare crown stent release unit comprises a chronic dilator release knob (174) and a bare crown stent release switch (176); the end of the single-lumen middle tube (130) is connected to an externally threaded slider (301), and the externally threaded slider (301) is connected to the chronic dilator release knob (174); the chronic dilator release knob (174) is configured to control the expansion and contraction of the chronic dilator (160); the proximal bare crown stent (210) is tied to the chronic dilator (160) by an elastic cord buckle (180), and one end of the elastic cord buckle (180) is connected to the bare crown stent release switch (176); or, The bare crown stent release unit comprises a chronic dilator release knob (174), a retaining binding wire (501) inserted into a circle of the proximal bare crown stent (210), a double-strand traction wire (502), and a fixing pin (503) arranged on the single-lumen middle tube (130), wherein the double-strand traction wire (502) is wound around the retaining binding wire (501); the front end of the double-strand traction wire (502) is connected to the fixing pin (503), the end of the double-strand traction wire (502) is connected to the external thread slider (301), and the external thread slider (301) is connected to the chronic dilator release knob (174), and the chronic dilator release knob (174) is configured to drive the retaining binding wire (501) to be tightened or relaxed through the double-strand traction wire (502), thereby forcing the proximal bare crown stent (210) to compress or expand; The distal end coated support release unit includes a coated segment release switch (175), the distal end coated support (220) is restrained on the adjustable bend (120) by a soft film (190), a draw wire (191) is passed through the soft film (190), the front end of the draw wire (191) is connected to the flexible TIP head (150), and the rear end of the draw wire (191) is connected to the coated segment release switch (175), and the coated segment release switch (175) is configured to release the distal end coated support (220) by pulling out the draw wire (191).

2. The ascending aorta covered stent and delivery system assembly according to claim 1, characterized in that: The adjustable curved tube (120) comprises a bendable section (121), a transition connecting rod (125) and a rear tough multi-lumen tube (122) which are connected in sequence, and the end of the rear tough multi-lumen tube (122) is fixedly connected to the adjustment handle; a plurality of traction wires (123) are passed through the adjustable curved tube (120), and the head ends of all the traction wires (123) are respectively fixedly connected to different positions of the front end of the bendable section (121), and the tail ends of all the traction wires (123) respectively pass through different azimuth holes (1251) of the transition connecting rod (125) and the rear tough multi-lumen tube (122) and are then connected to the steering assembly on the adjustment handle.

3. The ascending aorta covered stent and delivery system assembly according to claim 2, characterized in that: The steering assembly comprises a plurality of bending adjustment sliders (124), the adjustment handle comprises an X-axis direction adjustable bending knob (172) and a Y-axis direction adjustable bending knob (173), and the plurality of bending adjustment sliders (124) are respectively connected to the X-axis direction adjustable bending knob (172) or the Y-axis direction adjustable bending knob (173); and / or, The steering assembly comprises two rotating hand wheels (401), two spur gears (402) and four racks (403); each rotating hand wheel (401) is connected to one spur gear (402); two racks (403) are respectively meshed with one spur gear (402) from opposite sides; and the racks (403) are respectively connected to the tail of the traction wire (123).

4. The ascending aorta covered stent and delivery system assembly according to any one of claims 1 to 3, characterized in that: The outer sheath tube (110) comprises a three-layer structure arranged in sequence from the inside to the outside, the inner side is made of PTFE material, the middle layer is made of metal winding wire or braided mesh, and the outer layer is made of PEBAX, PU or PTFE material.

5. The ascending aorta covered stent and delivery system assembly according to any one of claims 1 to 3, characterized in that: The cylindrical film (222) is made of a biocompatible film material.

6. The ascending aorta covered stent and delivery system assembly according to any one of claims 1 to 3, characterized in that: The inclination angles of the front barb (211) and the rear barb (212) are both between 30° and 45°.

7. The ascending aorta covered stent and delivery system assembly according to any one of claims 1 to 3, characterized in that: A metal protective sleeve (111) is provided on the inner side of the outer sheath tube (110), and the proximal bare crown stent (210) is at least partially located in the metal protective sleeve (111) when in a contracted state.

8. The ascending aorta covered stent and delivery system assembly according to any one of claims 1 to 3, characterized in that: The reinforcement ring (223) is in a rhombus shape; or, the single support ring (221) and the reinforcement ring (223) are respectively in a sinusoidal shape, the width of the reinforcement ring (223) is smaller than the width of the single support ring (221), and the number of wave heads of the reinforcement ring (223) is greater than the number of wave heads of the single support ring (221).

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