Multi-branch intravascular stent flexible to use

Abstract

The invention relates to the technical field of medical instruments, in particular to a flexibly-used multi-branch intravascular stent which comprises a stent body and a blood vessel bridle, the stent body comprises a first main blood vessel, a second main blood vessel, a first branch, a second branch, a third branch, a fourth branch and a supporting ring, and an opening in the upper end of the first branch is a free movable end; an upper port of the second branch is a free movable port, an upper port of the third branch is a free movable port, one end of the fourth branch is a free movable port, and a near-end opening of the first main blood vessel is a free movable end; the far end of the first main blood vessel is communicated with the near end of the second main blood vessel; a flange edge is annularly arranged on the outer side wall of the far end of the first main blood vessel, and a supporting ring is annularly arranged on the outer side wall of the near end of the second main blood vessel. By means of operation, the time of profound hypothermia circulation arrest is greatly shortened, brain damage and organ damage to a patient are reduced, the application range of the intravascular stent assembly is expanded, and the intravascular stent assembly can be better matched with branch blood vessels of the patient.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a flexible multi-branched blood vessel stent. Background Art

[0002] Stanford type A aortic dissection or aortic aneurysm involving the aortic arch has always been one of the most complex and risky diseases in cardiovascular surgery. Currently, the mainstream treatment for this disease is the "Sun's surgery" founded by Professor Sun Lizhong.

[0003] The "Sun's operation" has solved the problem of aortic arch treatment, but it also has problems such as more anastomosis during the operation, longer cardiac arrest time, and greater damage to the patient. To address this problem, the current method is to implant a stent with three branches during the operation. The stent (such as Figure 1 ) usually includes a section of artificial blood vessel 31, a self-expanding vascular stent 11 sutured and connected to the artificial blood vessel, and three branch stents 21 connected to the self-expanding vascular stent using a soft membrane; the intraoperative stent can greatly reduce the anastomosis time between the branch stent 21 and the three branch blood vessels on the aortic arch (brachiocephalic trunk, left common carotid artery, left subclavian artery) during surgery, but because the artificial blood vessel 31 of the intraoperative stent still needs to be anastomosed with the patient's vascular stump, and the process is performed under deep hypothermic circulatory arrest conditions, this will lead to a long intraoperative deep hypothermic circulatory arrest time and increase the incidence of brain injury and postoperative complications in patients; on the other hand, the three branches of the intraoperative stent, the diameter and height are relatively fixed, while the size and position of the branch blood vessels of the patient are different, especially the patient's innominate artery has more branch blood vessels, and there are more variations, so it is difficult for the branch stent of the intraoperative stent to match the patient's branch blood vessels, and the customized stent is not suitable for emergency surgery, so the intraoperative stent has a small scope of clinical application. Summary of the invention

[0004] In view of the problems in the prior art, the present invention provides a flexible multi-branch vascular stent. Compared with the prior art, the present invention has a novel structure and ingenious design. The operation of the present invention greatly reduces the time of deep hypothermic circulatory arrest and reduces brain damage and organ damage to patients. At the same time, since the first branch, the second branch, and the third branch all have freely movable ports, the adaptability of the vascular stent assembly of the present invention is greatly expanded, and it can better match the branch blood vessels of the patient.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a flexible multi-branch blood vessel stent, which comprises a stent body and a blood vessel band, wherein the stent body comprises a first main blood vessel, a second main blood vessel, a first branch, a second branch, a third branch, a fourth branch and a support ring, wherein the first branch and the fourth branch are respectively connected to the proximal outer side wall of the first main blood vessel and communicated with the first main blood vessel, and the second branch and the third branch are respectively connected to the side wall of the second main blood vessel and communicated with the second main blood vessel; the upper end opening of the first branch is a free movable end, the upper port of the second branch is a free movable port, the upper port of the third branch is a free movable port, one end of the fourth branch is a free movable port, and the proximal end opening of the first main blood vessel is a free movable end;

[0007] The distal end of the first main blood vessel is connected and communicated with the proximal end of the second main blood vessel; a flange is arranged around the outer wall of the distal end of the first main blood vessel, and the support ring is arranged around the outer wall of the proximal end of the second main blood vessel;

[0008] The vascular band includes a band body and a buckle for fixing the band body, and the band body is used to cover the outer circumference of the support ring.

[0009] The first branch and the fourth branch are arranged at an angle of 90°, and the minimum distance between the first branch and the fourth branch is greater than 10 mm.

[0010] The proximal end of the first main blood vessel is a free end, and the diameter of the first main blood vessel is D1, wherein 20 mm ≤ D1 ≤ 42 mm.

[0011] The distance between the outer edge of the flange and the outer wall of the first main blood vessel is L1, wherein 12 mm ≤ L1 ≤ 25 mm.

[0012] Among them, the second main blood vessel is a hollow tubular structure; the proximal end of the second main blood vessel is provided with a variable diameter structure portion, the variable diameter structure portion includes a middle section and a conducting section arranged at both ends of the middle section, the diameter of the conducting section is D2, the diameter of the middle section is D3, wherein D2≤D3≤1.5*D2; the distal diameter of the second main blood vessel is D4, wherein 0mm≤D2-D4<6mm.

[0013] Wherein, the second main blood vessel comprises a polymer membrane and a metal corrugated ring with deformation recovery capability; the metal corrugated ring is arranged on the inner side and / or the outer side of the polymer membrane.

[0014] Wherein, the second main blood vessel comprises a polymer film and a metal corrugated ring with deformation recovery capability; the polymer film is arranged on the inner side and / or the outer side of the metal corrugated ring.

[0015] Wherein, a suture edge is further extended from the distal end of the polymer film, and the length of the suture edge is L2, wherein 2mm≤L2≤10mm.

[0016] Wherein, the support ring is made of a material with deformation recovery ability; the diameter of the support ring is the same as the diameter of the middle section, the length of the support ring is L3, wherein 10mm≤L3≤25mm, and the support ring is sleeved on the outer circumferential wall or the inner circumferential wall of the middle section.

[0017] Among them, the vascular band also includes a sealing strip and a ring. Semi-enclosed circular cavities are provided on both sides of the band body. The sealing strip is installed in the circular cavity. The ring is provided at one end of the band body. The band body is wrapped around the outer circumference of the support ring. The other end of the band body is wrapped around the support ring and then passed through the ring and then reversely stacked on the outer wall of the band body. The buckle is used to fix the stacked band bodies.

[0018] Beneficial effects of the present invention:

[0019] The invention has a novel structure and an ingenious design. When in use, the various parts of the vascular stent assembly are compressed on the delivery system. During surgical thoracotomy, the heart is stopped under deep hypothermic circulatory arrest conditions, the aorta of the patient is cut open, and the vascular stent assembly is implanted into the aorta through the delivery system, wherein the second main blood vessel is implanted into the aortic arch and the descending aorta, the second branch and the third branch are implanted into the left common carotid artery and the left subclavian artery respectively, and the proximal end of the second main blood vessel is implanted into the aorta between the innominate artery and the left common carotid artery, or the aorta proximal to the innominate artery. The patient's vascular stump is wrapped around the entire outside of the second main blood vessel; a vascular band is used to bind the patient's vascular stump and the support ring outside the support ring together, and the diameter of the support ring is shrunk, that is, the diameter of the support ring after contraction is the same as the diameter of the proximal end of the second main blood vessel; then the perfusion tube of the extracorporeal circulation is connected to the fourth branch, so that the patient's lower limb blood circulation and cerebral vascular perfusion can be restored, and finally the proximal opening of the first main blood vessel is connected to the patient's ascending aorta, the first branch is connected to the patient's innominate artery, and the flange is used to wrap and suture the opening of the patient's vascular stump, and the operation is completed. Compared with the prior art, the present invention greatly reduces the time of deep hypothermic circulatory arrest and reduces brain damage and organ damage to patients. At the same time, because the first branch, the second branch, and the third branch all have freely movable ports, the adaptability of the vascular stent assembly of the embodiment of the present application is greatly expanded, and it can better match the patient's branch blood vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an intraoperative stent in the prior art.

[0021] Figure 2 It is a schematic structural diagram of a flexible multi-branched vascular stent of the present invention.

[0022] Figure 3 It is a schematic diagram of the structure of the vascular band of the present invention.

[0023] Figure 4 This is a schematic structural diagram of the vascular band of the present invention from another viewing angle.

[0024] Figure 5 It is a schematic diagram of the structure of the cooperation between the tie belt body and the sealing strip of the present invention.

[0025] Figure 6 It is a schematic diagram of the distribution structure of the first main blood vessel, the first branch and the fourth branch of the present invention.

[0026] Figure 7 It is a schematic diagram of the structure of the flange edge of the present invention cooperating with the first main blood vessel.

[0027] Figure 8 It is a cross-sectional view of the second main blood vessel of the present invention.

[0028] Fig. 9 for Figure 8 Enlarged view of point A.

[0029] Fig.10 for Figure 8 Enlarged view of point B.

[0030] Fig.11 It is a schematic diagram of the structure of the polymer film and metal corrugated ring of the second main blood vessel of the present invention.

[0031] Fig.12 It is a schematic diagram of the structure of the cooperation between the variable diameter structure part and the support ring of the present invention.

[0032] Fig.13 It is a schematic diagram of the structure of the buckle of the present invention when it is opened.

[0033] Fig.14 It is a schematic diagram of the structure of the buckle of the present invention when it is closed.

[0034] Fig.15 It is a schematic diagram of the structure of the cooperation between the vascular band and the support ring of the present invention.

[0035] Fig.16 This is a schematic diagram of the structure in which the patient's vascular stump is wrapped around the outside of the entire second main blood vessel.

[0036] Fig.17 This is a schematic structural diagram of the present invention using a vascular band to bind the patient's vascular stump outside the support ring together with the support ring.

[0037] Fig.18 This is a schematic diagram of the structure of using a flange edge to wrap and sew up the opening of the patient's blood vessel stump.

[0038] exist Figures 1 to 18 Reference numerals in the drawings include:

[0039] 1. First branch; 2. First main blood vessel; 3. Flange edge; 4. Support ring; 5. Second branch; 6. Third branch; 7. Second main blood vessel; 8. Fourth branch; 9. Band body; 10. Sealing strip; 11. Ring; 12. Buckle;

[0040] 70. Metal corrugation; 71. Polymer film; 72. Metal rod; 73. Sewn edge;

[0041] 120. Movable rod; 121. Fixed rod. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention. It is understood that the drawings are only provided for reference and illustration, and are not used to limit the present invention. The connection relationship shown in the drawings is only for the convenience of clear description and does not limit the connection method.

[0043] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to another component, or there may be an intermediate component at the same time. Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as those generally understood by technicians in the technical field of the present invention. It should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0044] It should also be noted that in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0045] Embodiment 1

[0046] like Figures 1 to 18 As shown, a flexible multi-branch vascular stent includes a stent body and a vascular band, the stent body includes a first main blood vessel 2, a second main blood vessel 7, a first branch 1, a second branch 5, a third branch 6, a fourth branch 8 and a support ring 4, the first branch 1 and the fourth branch 8 are respectively connected to the proximal outer wall of the first main blood vessel 2 and communicated with the first main blood vessel 2, the second branch 5 and the third branch 6 are respectively connected to the side wall of the second main blood vessel 7 and communicated with the second main blood vessel 7; wherein the first main blood vessel 2, the second main blood vessel 7, the first branch 1, the second branch 5, the third branch 6, and the fourth branch 8 are all hollow tubular structures;

[0047] The upper opening of the first branch 1 is a free active end, and the lower opening of the first branch 1 is connected to the first main blood vessel 2. The two can be sutured together with sutures, or they can be woven into an integral form. The lower opening of the first branch 1 is connected to the first main blood vessel 2 to ensure that when blood flows through the first main blood vessel 2, part of the blood can flow to the first branch 1;

[0048] The fourth branch 8 is similar to the first branch 1, one end of the fourth branch 8 is a freely movable port, and the other end of the fourth branch 8 is connected to the first main blood vessel 2, and the two can be sutured together with sutures, or they can be woven into an integral form; the fourth branch 8 is connected to the first main blood vessel 2 to ensure that blood can flow from the freely movable port of the fourth branch 8 to the lumen of the first main blood vessel 2;

[0049] The upper port of the second branch 5 is a free active port, and the lower port of the second branch 5 is connected to the side wall of the second main blood vessel 7 and the lumens of the two are completely connected, so as to ensure that when blood flows through the second main blood vessel 7, blood flows through the interior of the second branch 5;

[0050] The upper port of the third branch 6 is a free active port, and the lower port of the third branch 6 is connected to the side wall of the second main blood vessel 7 and the lumens of the two are completely connected to ensure that when blood flows through the second main blood vessel 7, blood flows through the inside of the third branch 6;

[0051] The distal end of the first main blood vessel 2 is connected and communicated with the proximal end of the second main blood vessel 7; a flange 3 is provided around the distal outer wall of the first main blood vessel 2, and a support ring 4 is provided around the proximal outer wall of the second main blood vessel 7; the first main blood vessel 2 is a hollow tubular structure, the proximal opening of the first main blood vessel 2 is a free active end, and the distal opening of the first main blood vessel 2 is connected and communicated with the proximal opening of the second main blood vessel 7;

[0052] The vascular band includes a band body 9 and a buckle 12 for fixing the band body 9 . The band body 9 is used to be wrapped around the outer circumference of the support ring 4 .

[0053] Specifically, the present invention has a novel structure and an ingenious design. When in use, the various parts of the vascular stent assembly are compressed on the delivery system. During surgical thoracotomy, the heart is stopped under deep hypothermic circulatory arrest conditions, the patient's aortic vessels are cut, and the vascular stent assembly is implanted into the aortic vessels through the delivery system, wherein the second main blood vessel 7 is implanted into the aortic arch and the descending aorta, the second branch 5 and the third branch 6 are implanted into the left common carotid artery and the left subclavian artery, respectively, and the proximal end of the second main blood vessel 7 is implanted into the aortic vessel between the innominate artery and the left common carotid artery, or the aortic vessel proximal to the innominate artery. At this time, the patient's vascular stump is wrapped around the entire outside of the second main blood vessel 7, as shown in FIG. Fig.16 As shown; use a vascular band to bind the patient's blood vessel stump and the support ring 4 outside the support ring 4 together, and shrink the diameter of the support ring 4, that is, after shrinkage, the diameter of the support ring 4 is the same as the diameter of the proximal end of the second main blood vessel 7, as shown Fig.17 As shown; then the perfusion tube of the extracorporeal circulation is connected to the fourth branch 8, so that the patient's lower limb blood circulation and cerebral vascular perfusion can be restored. Finally, the proximal opening of the first main blood vessel 2 is connected to the patient's ascending aorta, the first branch 1 is connected to the patient's innominate artery, and the opening of the patient's vascular stump is wrapped and sutured with the flange edge 3, and the operation is completed. Fig.18 Compared with the prior art, the embodiment of the present application greatly reduces the time of deep hypothermic circulatory arrest, reduces the brain damage and organ damage to the patient, and at the same time, because the first branch 1, the second branch 5, and the third branch 6 all have freely movable ports, the adaptability of the vascular stent assembly of the embodiment of the present application is greatly expanded, and it can better match the branch blood vessels of the patient.

[0054] In the embodiment of the present application, the material of the first branch 1 is preferably retractable polyethylene terephthalate (PET), which is at its original length in its natural state. Under extremely small pulling force, the first branch 1 can achieve an elongation of 100%-300%; the inner and outer surfaces of the first branch 1 can be optionally coated with a blood-proof coating; the material of the first branch 1 can also be polytetrafluoroethylene (PTFE); there is no metal support on the inner and / or outer sides of the first branch 1 to ensure that the first branch 1 has better freedom and can swing flexibly; the diameter of the first branch 1 is usually 8mm, 10mm, 12mm, 14mm, and 16mm to choose from, and the length is greater than 100mm. More diameter options and longer length can ensure that the first branch 1 has greater freedom. Even if there are more variations in the patient's innominate artery, the first branch 1 can still be well matched with the patient's innominate artery.

[0055] In the embodiment of the present application, the first branch 1 and the fourth branch 8 are arranged at an angle of 90°, and the minimum distance between the first branch 1 and the fourth branch 8 is greater than 10 mm; the material and structure of the fourth branch 8 are consistent with those of the first branch 1, and the size is somewhat different from that of the first branch 1. The diameter of the fourth branch 8 is preferably 10 mm, and the length is greater than 100 mm; the fourth branch 8 and the first branch 1 are distributed at 90° in the circumferential direction of the first main blood vessel 2, such as Figure 6 As shown; viewed in the axial direction of the first main blood vessel 2, the first branch 1 is closer to the proximal end of the first main blood vessel 2, while the minimum distance between the fourth branch 8 and the first branch 1 is greater than 10 mm.

[0056] In the embodiment of the present application, the proximal end of the first main blood vessel 2 is a free active end, and the diameter of the first main blood vessel 2 is D1, wherein 20mm≤D1≤42mm. The material of the first main blood vessel 2 is preferably retractable PET, which is at its original length in a natural state. Under a very small tensile force, the first main blood vessel 2 can achieve an elongation of 100%-300%; the inner and outer surfaces of the first main blood vessel 2 can be optionally coated with a blood-proof coating; the diameter size of the first main blood vessel 2 is D1, and the range of D1 is 20mm-42mm.

[0057] In the embodiment of the present application, the distance between the outer edge of the flange 3 and the outer wall of the first main blood vessel 2 is L1, where 12mm≤L1≤25mm; the flange 3 is in a circular shape and is nested on the outside of the first main blood vessel 2. The material of the flange 3 is preferably PET, but it can also be PTFE or other polymer materials.

[0058] In the embodiment of the present application, the second main blood vessel 7 is a hollow tubular structure; the proximal end of the second main blood vessel 7 is provided with a diameter-changing structure portion, that is, Fig. 9In the structure shown, the variable diameter structure portion includes a middle section and conducting sections arranged at both ends of the middle section. Under the above setting, the variable diameter structure portion is "spindle-shaped" with equal diameters at both ends; the diameter of the conducting section is D2, and the diameter of the middle section is D3, wherein D2≤D3≤1.5*D2; the distal diameter of the second main blood vessel 7 is D4, wherein 0mm≤D2-D4<6mm.

[0059] In the embodiment of the present application, the second main blood vessel 7 includes a polymer film 71 and a metal corrugated ring 70 with deformation recovery ability; the metal corrugated ring 70 is arranged on the inner side or / and the outer side of the polymer film 71; a plurality of metal corrugated rings 70 may be provided, and the plurality of metal corrugated rings 70 are arranged in a row at equal intervals along the length direction of the second main blood vessel 7. The metal corrugated ring 70 may be woven from metal wires with shape memory function, or cut from metal pipes with shape memory function. After undergoing different metal heat treatments, they have similar functions, that is, they can be compressed to a state where the diameter is much smaller than the patient's blood vessel diameter at a certain temperature. After being released during the operation, they automatically expand to their original state to ensure that the blood flow can pass smoothly in the second main blood vessel 7; the metal corrugated ring 70 is arranged from the right side of the variable diameter structure to the distal end of the second main blood vessel 7. They are independent of each other and can move freely axially to ensure that the blood flow can pass smoothly through the second main blood vessel 7. This ensures that the second main blood vessel 7 has good flexibility; the polymer membrane 71 is usually made of PET or PTFE membrane, and the second main blood vessel 7 including the polymer membrane 71 of the variable diameter structure at its proximal end is an integrated structure; the metal wave ring 70 is on the inner side or outer side of the polymer membrane 71, or is arranged on the inner side and outer side of the polymer membrane 71 at the same time, or the polymer membrane 71 is arranged on both sides of the metal wave ring 70, and the whole presents a "sandwich" structure; the polymer membrane 71 and the metal wave ring 70 are tightly attached together; the connection between the polymer membrane 71 and the metal wave ring 70 is generally achieved by suturing or high-temperature firing.

[0060] In the embodiment of the present application, the distal end of the polymer film 71 is further extended with a suture edge 73, and the length of the suture edge 73 is L2, wherein 2mm≤L2≤10mm; at the distal end of the second main blood vessel 7, the length of the polymer film 71 exceeds the length of the metal corrugated ring 70, i.e., the suture edge 73, as shown in FIG. Fig.11 As shown, the length L2 of the suture edge 73 is 2 mm-10 mm, so that blood vessels can be anastomosed at this position during a secondary operation.

[0061] In the embodiment of the present application, the support ring 4 is made of a material with deformation recovery ability; the diameter of the support ring 4 is the same as the diameter of the middle section, the length of the support ring 4 is L3, wherein 10mm≤L3≤25mm, and the support ring 4 is sleeved on the outer peripheral wall or the inner peripheral wall of the middle section. Specifically, the support ring 4 is a ring-shaped structure with a self-expansion function, such as Fig.12As shown, similar to the metal corrugated ring, the support ring 4 can also be woven from metal wires with shape memory function, or cut from metal tubes with shape memory function; the diameter of the support ring 4 is consistent with the diameter of the middle section of the variable diameter structure, both of which are D3; its length L3 ranges from 10mm to 25mm; the support ring 4 is usually set in the middle section of the variable diameter structure of the second main blood vessel 7, on the inner side of the polymer membrane of the second main blood vessel 7 or using a polymer membrane to cover the support ring 4 in the middle, forming a "sandwich" structure.

[0062] In the embodiment of the present application, the composition and material of the second branch 5 are related to the second main blood vessel 7. When the polymer membrane of the second main blood vessel 7 is PET, the composition of the second branch 5 preferably includes PET and metal corrugations, and the metal corrugations of the second branch 5 are arranged on the outside or inside of the PET membrane of the second branch 5, or the second branch 5 selects a retractable PET, and the second branch 5 is connected to the second main blood vessel 7 by suture suture. When the polymer membrane of the second main blood vessel 7 is a PTFE membrane, the composition of the second branch 5 includes a PTFE membrane and a metal corrugation, and the second branch 5 and the polymer membrane of the second main blood vessel 7 are integrally fired, and the polymer membrane of the second branch 5 is arranged on the inside and outside of the metal corrugation of the second branch 5, and the whole is a "sandwich" structure. The diameter size range of the second branch 5 is 8mm-16mm, and the length range is 20mm-40mm.

[0063] In the embodiment of the present application, the composition and material of the third branch 6 are related to the second main blood vessel 7. When the polymer membrane of the second main blood vessel 7 is PET, the composition of the third branch 6 preferably includes PET and metal corrugations, and the metal corrugations of the third branch 6 are arranged on the outside or inside of the PET membrane of the third branch 6. At this time, the third branch 6 and the second main blood vessel 7 are connected by sutures; when the polymer membrane of the second main blood vessel 7 is PTFE membrane, the composition of the third branch 6 includes PTFE membrane and metal corrugations, and at this time, the third branch 6 and the polymer membrane of the second main blood vessel 7 are integrally fired, and the polymer membrane of the third branch 6 is arranged on the inside and outside of the corrugations of the third branch 6, forming a "sandwich" structure as a whole. The diameter size range of the third branch 6 is 8mm-16mm, and the length range of the third branch 6 is 20mm-40mm; the difference between the third branch 6 and the second branch 5 is that the second branch 5 is close to the proximal end of the second main blood vessel 7, and the third branch 6 is close to the distal end of the second main blood vessel 7, and the minimum distance between the second branch 5 and the third branch 6 is 0mm-15mm.

[0064] In the embodiment of the present application, the vascular band also includes a sealing strip 10 and a ring 11. Semi-enclosed circular cavities are provided on both sides of the band body 9, and the sealing strip 10 is installed in the circular cavity. A ring 11 is provided at one end of the band body 9. The band body 9 is wrapped around the outer periphery of the support ring 4. The other end of the band body 9 is wrapped around the support ring 4 and then passed through the ring 11 and then reversely stacked on the outer wall of the band body 9. The buckle 12 is used to fix the stacked band body 9; wherein the band body 9 is a soft polymer material, commonly used materials such as PET, PTFE, etc.

[0065] Specifically, semi-enclosed circular cavities are provided on both sides of the belt body 9, and the sealing strip 10 passes through the circular cavity. The sealing strip 10 is a solid rod-shaped structure, and the preferred material is silicone. The length of the sealing strip 10 is equal to that of the belt body 9. The position relationship between the two is as follows: Figures 3 to 5 As shown; the length of the strap is 15cm-20cm, and the required length can be adaptively adjusted according to the diameter of the support ring 4 when in use.

[0066] Among them, a loop 11 is provided at one end of the band body 9, and the loop 11 is a quadrilateral, closed ring structure. One side of the loop 11 is fixedly connected to one end of the band body 9. Preferably, the two sides adjacent to the side where the loop 11 is connected to the band body 9 are arc-shaped sides. When the vascular band is used, the center of the circle corresponding to the arc-shaped side of the loop 11 should face the center line of the blood vessel so that the loop 11 can better fit the blood vessel wall.

[0067] Among them, the buckle 12 is used to clamp the folded and stacked straps together to prevent them from slipping, so that the vascular strap is tightly bound to the vascular stump and the outer wall of the vascular stent. The buckle 12 can be made of a material with good elasticity, such as stainless steel, spring steel, etc. We use such a design to enable the buckle 12 to clamp the strap.

[0068] as follows Figures 13 to 15 As shown, the buckle 12 includes a movable rod 120 and a fixed rod 121. The left side of the fixed rod 121 is a semi-closed circular ring. The distance from the opening of the circular ring to the fixed rod 121 is L. The right side of the fixed rod 121 is connected to the right side of the movable rod 120 as a whole. The movable rod 120 and the fixed rod 121 form a certain angle a. The distance from the lowest point on the right side of the movable rod 120 to the fixed rod 121 is h. If the diameter of the sealing strip 10 is A, L<A and h<A should be satisfied. The distance from the highest point on the left side of the movable rod 120 to the fixed rod 121 is H, and H should be greater than A. When in use, the folded and stacked strap is passed through the buckle 12, and the left side of the movable rod 120 is pressed down to the inner side of the opening of the semi-closed circular ring on the left side of the fixed rod 121, so that the movable rod 120 no longer bounces up, and the folded and stacked strap body 9 can be clamped. The schematic diagram of the use of the buckle 12 is as follows Figures 13 to 15As shown; the above is the basic idea of ​​the buckle 12 clamping the strap body 9. Preferably, the outside of the buckle 12 can be coated with a wrapping layer, which can not only enhance the blood compatibility of the buckle 12, but also increase the friction between the movable rod 120 of the buckle 12 and the semi-closed circular ring, so that the buckle 12 and the strap are relatively more secure; or the movable rod 120 and the fixed rod 121 of the buckle 12 are both set to a wavy structure or other structures, so as to increase the friction by increasing the contact area between the buckle 12 and the strap body 9, so that the combination is more secure.

[0069] Embodiment 2

[0070] In the second embodiment of the present application, the second main blood vessel 7 includes a polymer film 71 and a metal corrugated ring 70 with deformation recovery capability; the polymer film 71 is arranged on the inner side and / or the outer side of the metal corrugated ring 70 .

[0071] Embodiment 3

[0072] In the third embodiment of the present application, a metal rod 72 is used to connect two adjacent metal corrugations 70, so that the second main blood vessel 7 has a good rigidity. Fig.11 The metal rods 72 can be on the same straight line or randomly distributed on the circumference of the polymer film 71 to connect the metal corrugations 70 one by one in series.

[0073] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technology of the present invention are within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.

Claims

1. A flexible multi-branch vascular stent, characterized in that: The invention comprises a stent body and a vascular band, wherein the stent body comprises a first main blood vessel, a second main blood vessel, a first branch, a second branch, a third branch, a fourth branch and a support ring, wherein the first branch and the fourth branch are respectively connected to the proximal outer side wall of the first main blood vessel and communicate with the first main blood vessel, and the second branch and the third branch are respectively connected to the side wall of the second main blood vessel and communicate with the second main blood vessel; the upper end opening of the first branch is a free movable end, the upper port of the second branch is a free movable port, the upper port of the third branch is a free movable port, one end of the fourth branch is a free movable port, and the proximal end opening of the first main blood vessel is a free movable end; The distal end of the first main blood vessel is connected and communicated with the proximal end of the second main blood vessel; a flange is arranged around the outer wall of the distal end of the first main blood vessel, and the support ring is arranged around the outer wall of the proximal end of the second main blood vessel; The vascular band comprises a band body and a buckle for fixing the band body, and the band body is used to cover the outer circumference of the support ring.

2. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The first branch and the fourth branch are arranged at an angle of 90°, and the minimum distance between the first branch and the fourth branch is greater than 10 mm.

3. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The proximal end of the first main blood vessel is a free end, and the diameter of the first main blood vessel is D1, wherein 20 mm≤D1≤42 mm.

4. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The distance between the outer edge of the flange and the outer wall of the first main blood vessel is L1, wherein 12 mm ≤ L1 ≤ 25 mm.

5. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The second main blood vessel is a hollow tubular structure; a variable diameter structure portion is provided at the proximal end of the second main blood vessel, the variable diameter structure portion includes a middle section and a conducting section provided at both ends of the middle section, the diameter of the conducting section is D2, the diameter of the middle section is D3, wherein D2≤D3≤1.5*D2; the distal diameter of the second main blood vessel is D4, wherein 0mm≤D2-D4<6mm.

6. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The second main blood vessel comprises a polymer film and a metal corrugated ring with deformation recovery capability; the metal corrugated ring is arranged on the inner side and / or the outer side of the polymer film.

7. The multi-branch vascular stent for flexible use according to claim 1, characterized in that: The second main blood vessel comprises a polymer film and a metal corrugated ring with deformation recovery capability; the polymer film is arranged on the inner side and / or the outer side of the metal corrugated ring.

8. The multi-branched vascular stent for flexible use according to claim 6 or 7, characterized in that: A sewing edge is further extended from the distal end of the polymer film, and the length of the sewing edge is L2, wherein 2mm≤L2≤10mm.

9. The multi-branched vascular stent for flexible use according to claim 5, characterized in that: The support ring is made of a material with deformation recovery ability; the diameter of the support ring is the same as the diameter of the middle section, the length of the support ring is L3, wherein 10mm≤L3≤25mm, and the support ring is sleeved on the outer circumferential wall or the inner circumferential wall of the middle section.

10. The multi-branched vascular stent for flexible use according to claim 1, characterized in that: The vascular band also includes a sealing strip and a ring. Semi-enclosed circular cavities are provided on both sides of the band body. The sealing strip is installed in the circular cavity. The ring is provided at one end of the band body. The band body is wrapped around the outer circumference of the support ring. The other end of the band body is wrapped around the support ring and then passed through the ring to be reversely stacked on the outer wall of the band body. The buckle is used to fix the stacked band bodies.

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