A vascular stent

Abstract

The present invention discloses a vascular stent, which comprises a plurality of single-ring stents arranged at intervals along the axial direction. While extending circumferentially, the single-ring stents undulate axially in a wavy shape; a plurality of connectors, with adjacent two single-ring stents connected by the connectors; wherein, the connectors include two first circumferential connectors and at least one axial connector; one of the first circumferential connectors connects the peak of one single-ring stent circumferentially, and the other first circumferential connector connects the trough of another single-ring stent circumferentially; the axial connector connects the peaks or troughs or the first circumferential connectors of adjacent two single-ring stents axially, and the axial connector is unevenly distributed in the circumferential direction. The vascular stent of the present invention has different support performance and compliance performance in the circumferential direction, can better adapt to the vascular anatomical structure, and at the same time has excellent bending performance and fatigue performance.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical engineering, and particularly relates to a vascular stent. Background Art

[0002] Thoracic Endovascular Aortic Repair (TEVAR) is a minimally invasive interventional treatment. Through percutaneous puncture of the femoral artery, interventional devices such as a covered stent are guided by imaging equipment and transported along the femoral artery to the lesion site to locally isolate the dissected area in the vascular lumen. Due to its many advantages such as small trauma, fast recovery, and avoidance of some complications of surgical operations, it is widely used clinically.

[0003] The aortic blood vessel presents a certain taper in its axial direction. The blood vessel diameter at the proximal end is larger, and the blood vessel diameter at the distal end is smaller. After TEVAR, it may lead to Stent-Induced New Entry (SINE). SINE means that the straight covered stent does not completely match the conical blood vessel morphology. When the covered stent is intervened, the distal end of the stent overopens, generating a large shear stress on the aortic dissection septum, thereby triggering a new tear. Usually, before the covered stent is released during TEVAR, a Restrictive Bare stent (RBS) is pre-placed at the distal end of the covered stent to limit the overopening of the distal end of the covered stent and prevent the occurrence of SINE.

[0004] The existing aortic covered stents and restrictive stents have the following defects:

[0005] 1. The exposed area extending from the end of some existing covered stents may compress the inner wall of the blood vessel, increasing the risk of intimal rupture. Some existing covered stents are usually formed by sewing multiple stent single rings with a polymer film. A small section of exposed stent single ring will extend from the proximal end or the distal end of the covered stent for hooking the delivery system to adapt to the loading, pushing, and releasing of the delivery system. However, the blood vessel peristalsis occurs with the beating of the heart. When the covered stent is completely released at the lesion site, the exposed area extending from the covered stent will squeeze against the inner wall of the blood vessel, and may even pierce through the weak intima of the lesion area blood vessel.

[0006] 2. The stent vertices at both ends of the bare stent may compress the inner wall of the blood vessel, increasing the risk of intimal rupture. The two ends of the bare stent are similar to the exposed sections extending from the above-mentioned covered stents. When the bare stent is completely released at the lesion site, the two ends of the bare stent will squeeze against the inner wall of the blood vessel with the peristalsis of the blood vessel, and may even pierce through the weak intima of the lesion area blood vessel.

[0007] 3. The shortening rate of the stent is relatively large, that is, the length of the tubular stent in its axial direction is prone to decrease. The reason for this phenomenon is mostly due to the poor way of connecting the ring stents. Reason for shortening one: After the existing stent is axially stressed, the connecting body is extremely easy to reverse axially, causing the stent to axially shorten. Moreover, the greater the axial length of the connecting body, the greater the shortening rate. Reason for shortening two: The existing stents are mostly composed of multiple independent single-ring stents connected together, and the connecting body is a metal wire or a polymer wire, etc. By winding or knotting the silk thread at the wave peaks and wave troughs, multiple single-ring stents are then connected into a complete stent. However, the silk thread knots are prone to slide on the wave bars of the stent. When the knots slide from the wave peaks and wave troughs to the middle section of the wave bar, the stent not only shortens as a whole, but its shape will also change unpredictably, thereby affecting the performance of the overall stent.

[0008] 4. The bending performance of some bare stents is poor. After some existing bare stents are bent greatly, the bending cross-section of the stent is distorted, and the cross-sectional shape changes from circular to an oval-like shape with acute angles. The major axis of the oval is larger than the inner diameter of the blood vessel at the diseased site, and the acute angles may scratch the inner wall of the blood vessel. At the same time, after some existing bare stents are bent greatly, internal folding will occur at the small bend, and the cross-sectional area becomes smaller, resulting in the outer surface of the stent being unable to fit well with the inner wall of the blood vessel.

[0009] 5. At the present stage, there are relatively few vascular stents specifically used for treating Debakey type II, especially for Debakey type II without the need for branch vessel reconstruction and the dissection not involving the aortic arch. Since the ascending aorta is short and close to the heart, to prevent the vascular stent inserted into this part from falling off, the stent needs to have a certain length sufficient to span the aortic arch and complete anchoring. If a traditional covered stent is used for interventional treatment, the polymer film will block the blood supply of some branches of the aortic arch, so it is necessary to open holes in the film and complete the precise adaptation of the holes to the branch vessels, which greatly increases the difficulty of the surgical operation.

[0010] 6. The radial support force distribution of some bare stents as a whole is uneven in the axial direction, that is, the radial support forces of the single-ring stent and the connecting body differ greatly. The existing stent's radial support force is provided by the single-ring stent, and the bending performance is provided by the connecting body silk thread, while the silk thread has almost no radial support force. This results in uneven radial support force distribution of the overall stent. The single-ring stent must have sufficient radial support force to stably anchor the overall stent in the blood vessel without sliding. Therefore, the pressure generated by the single-ring stent on the inner wall of the blood vessel is much greater than that of the connecting body part, and the inner wall of the patient's blood vessel is very weak. The single-ring stent generating a large pressure is very likely to cause secondary damage to the inner wall of the blood vessel.

[0011] 7. The mechanical property specifications of some existing bare stents are relatively single. According to the structural design and manufacturing technology of some existing stents, only the mechanical properties of the single-ring stent can be adjusted, and the mechanical properties of the single-ring stent mainly depend on two parts: the size of the wave rod cross-section and the performance of the manufacturing material itself. The size specification of the wave rod cross-section is relatively fixed, and the mechanical properties of the material itself need to be debugged through complex processes. Therefore, based on the structural design and manufacturing technology of the existing stent, it is very difficult to produce stents with a variety of different mechanical properties.

[0012] 8. Some existing bare stents are prone to phenomena such as eccentricity and collapse of the stent ring. After some existing bare stents are implanted, the probability of faults such as separation, fracture, and dislocation of the stent ring is as high as 9.2%. Especially for the bare stent part extending to the abdominal aorta, it is extremely prone to phenomena such as eccentricity and collapse, which is caused by the lack of radial support force and axial support of the stent. Summary of the Invention

[0013] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a vascular stent that has different support performance and compliance performance in the circumferential direction, can better adapt to the vascular anatomical structure, and has excellent bending performance and fatigue performance.

[0014] To achieve the above purpose and other related purposes, the present invention provides a vascular stent, including a plurality of single-ring stents arranged at intervals along the axial direction. While the single-ring stents extend circumferentially, they undulate axially in a wave shape.

[0015] A plurality of connectors connect adjacent two single-ring stents.

[0016] Among them, the connector includes two first circumferential connectors and at least one axial connector.

[0017] One of the first circumferential connectors connects the wave crest of one single-ring stent in the circumferential direction, and the other first circumferential connector connects the wave trough of the other single-ring stent in the circumferential direction.

[0018] The axial connector connects the wave crests or wave troughs or the first circumferential connectors of two adjacent single-ring stents in the axial direction, and the axial connector is unevenly distributed in the circumferential direction.

[0019] In an optional embodiment of the present invention, the material of the single-ring stent is a shape memory alloy.

[0020] In an optional embodiment of the present invention, the single-ring stent includes a wave crest, a wave trough, and a wave rod connecting the wave crest and the wave trough. The wave rod is tangent or not tangent to the wave crest / wave trough.

[0021] In an alternative embodiment of the present invention, the relative positions of the single-ring stents of the vascular stent are the same or different.

[0022] In an alternative embodiment of the present invention, the material of the connecting body is a shape memory alloy.

[0023] In an alternative embodiment of the present invention, the connecting body is in a grid form.

[0024] In an alternative embodiment of the present invention, the vascular stent further includes a film, and the film is attached to the single-ring stent or the connecting body.

[0025] In an alternative embodiment of the present invention, the first circumferential connecting body is annular, and the first circumferential connecting body is connected to the trough / crest of the single-ring stent by a winding method.

[0026] In an alternative embodiment of the present invention, the vascular stent further includes a second circumferential connecting body, and the second circumferential connecting body winds around the axial connecting body in the circumferential direction.

[0027] In an alternative embodiment of the present invention, the first circumferential connecting body is a single-strand metal wire or a multi-strand twisted metal wire; the second circumferential connecting body is a single-strand metal wire or a multi-strand twisted metal wire.

[0028] In an alternative embodiment of the present invention, the first circumferential connecting body includes a first knot, and the first knot is a knot wound around the crest or trough of the single-ring stent.

[0029] In an alternative embodiment of the present invention, the axial connecting body winds around the crest / trough and passes through the gap of the first knot.

[0030] In an alternative embodiment of the present invention, the number of the first knots of one first circumferential connecting body is greater than or equal to half of the number of the crests / troughs of one single-ring stent.

[0031] In an alternative embodiment of the present invention, the first circumferential connecting body further includes a second knot, and the second knot is a knot formed by the self-winding of the first circumferential connecting body and located between adjacent crests or troughs of the single-ring stent, and the axial connecting body is intertwined and wound around the crest, the first knot, the second knot, the trough and the first knot.

[0032] In an alternative embodiment of the present invention, the axial connecting body winds in the gap of the second knot.

[0033] In an alternative embodiment of the present invention, the axial connecting body includes at least two, one axial connecting body is in an "N" shape, and the other axial connecting body is in a reverse "N" shape.

[0034] In an alternative embodiment of the present invention, the axial connectors are distributed on a partial circumference of the vascular stent.

[0035] In an alternative embodiment of the present invention, the cross-sectional dimension of the metal wire of the connector is smaller than the cross-sectional dimension of the wire of the single-ring stent.

[0036] In an alternative embodiment of the present invention, the ratio of the cross-sectional dimension of the wire of the single-ring stent to the cross-sectional dimension of the metal wire of the connector is between 2 and 20.

[0037] The vascular stent of the present invention has good bending performance, can obtain different circumferential support performance and compliance performance as needed, and can better adapt to the curved vascular environment.

[0038] The vascular stent of the present invention can not only maintain the uniformity of the stent shape, but also obtain different circumferential support performance and compliance performance. The different circumferential support performance and compliance performance of the overall stent can better adapt to the vascular anatomical structure.

[0039] The combination of the local film covering and the excellent bending performance of the stent of the present invention enables the vascular stent of the present invention to be used for the interventional treatment of Debakey type II without the need for branch vessel reconstruction and without the dissection involving the aortic arch.

[0040] The vascular stent of the present invention has better fatigue resistance and will not cause damage to the inner wall of the blood vessel.

[0041] The preparation method of the vascular stent of the present invention can easily change the overall mechanical properties of the stent and produce more stents with different mechanical property specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Shows a schematic structural view of the vascular stent of the present invention.

[0043] Figure 2 Shows a three-dimensional structural view of the single-ring stent of the vascular stent of the present invention.

[0044] Figure 3 Shows a front view of the single-ring stent of the vascular stent of the present invention.

[0045] Figure 4 Shows a schematic structural view when the lengths of the wave rods of the single-ring stent of the vascular stent of the present invention are not equal.

[0046] Figures 5a - 5c Shows a schematic view of three alternative forms of the wave crest or wave trough of the vascular stent of the present invention.

[0047] Figure 6Shows a schematic diagram of the relative positions of the single-ring stent of the vascular stent of the present invention.

[0048] Figure 7 Shows a three-dimensional structural schematic diagram of the connector of the vascular stent of the present invention.

[0049] Figure 8 Shows a front view of the connector of the vascular stent of the present invention.

[0050] Figure 9 Shows a winding schematic diagram of the connector of the vascular stent of the present invention.

[0051] Figures 10a - 10e Shows five alternative schematic diagrams of the grid form of the connector of the vascular stent of the present invention.

[0052] Figure 11 Shows a structural schematic diagram of the film covering of the vascular stent of the present invention.

[0053] Figure 12a and 12b Respectively show a comparative schematic diagram of a partial existing stent and the vascular stent of the present invention in a large bending form.

[0054] Figure 13a and 13b Respectively show a morphological comparison diagram of a partial existing stent and the vascular stent of the present invention after the free side is stressed.

[0055] Figure 14 Shows a schematic diagram of the vascular stent of the present invention for treating DeBakey type II dissection.

[0056] Figure 15 Shows Figure 14 A partial enlarged view of the boxed area in

[0057] Figures 16a - 16c Respectively show a comparative schematic diagram of the morphology of a partial existing stent and the vascular stent of the present invention after being implanted into a blood vessel.

[0058] Label description

[0059] Vascular stent 100, non-film-covered section 100a, film-covered section 100b, single-ring stents 10, 10', peak 101, wave rod 102, trough 103, tube sleeve 104, connectors 20, 20', 21 circumferential connectors, first circumferential connector 211, first knot 2111, second knot 2112, second circumferential connector 212, axial connector 22, first axial connector 22a, second axial connector 22b, film covering 30, sheath tube 40, fixed claw head 50, inner core tube 60, ascending aorta 701, aortic arch 702, descending aorta 703, branch blood vessel 704, dissection 705. Detailed implementation manners

[0060] The following describes the implementation manners of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0061] Please refer to Figures 1 - 1 6. It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0062] For the convenience of description, the following explains the professional terms appearing in the text:

[0063] Minor bend: Blood vessels, stents, etc. are approximately circular tubes. When they are bent, the side with a smaller bending radius is the minor bend side.

[0064] Major bend: Blood vessels, stents, etc. are approximately circular tubes. When they are bent, the side with a larger bending radius is the major bend side.

[0065] Proximal end: The arterial blood vessels that originate from the heart gradually branch into capillaries and then gradually converge into venous blood vessels and return to the heart. For any section of blood vessel, the end closer to the heart is called the proximal end.

[0066] Distal end: The arterial blood vessels that originate from the heart gradually branch into capillaries and then gradually converge into venous blood vessels and return to the heart. For any section of blood vessel, the end farther from the heart is called the distal end.

[0067] Axial direction: Blood vessels, interventional stents, etc. are approximately circular tubes. If they are regarded as cylinders, the rotation axis of the cylinder is defined as the axial direction.

[0068] Radial direction: The "radial direction" is perpendicular to the "axial direction", that is, the radius or diameter direction of the end face circle of the cylinder, and the radial direction is perpendicular to the axial direction in space.

[0069] Circumferential direction: The "circumferential direction" is the circumferential direction, which together with the "axial direction" and the "radial direction" constitutes the three orthogonal directions of the cylindrical coordinate.

[0070] The present invention introduces an interventional vascular stent 100 (which can also be called a vascular stent). Among them, Figure 1 The structural schematic diagram of the vascular stent 100 of the present invention is shown. As Figure 1As shown, the vascular stent serves as the entire prosthesis for interventional treatment. The vascular stent 100 is an assembly composed of three components, namely, the single-ring stent 10, the connector 20, and the membrane 30, through a certain process.

[0071] It should be noted that in some embodiments, the vascular stent 100 may not include the membrane 30, but is directly an assembly composed of the single-ring stent 10 and the connector 20 through a certain process. Hereinafter, the case where the vascular stent 100 includes the single-ring stent 10, the connector 20, and the membrane 30 will be described as an example.

[0072] As Figure 1 shown, in the present invention, the vascular stent 100 is composed of multiple-ring single-ring stents 10 and multiple-ring connectors 20. The whole vascular stent is a tubular network structure. The membrane 30 is a layer of flexible film material attached to the single-ring stent 10 or the connector 20. The multiple-ring single-ring stents 10 are arranged in parallel at intervals in sequence from the proximal end to the distal end of the vascular stent 100. There is one ring of connector 20 between every two adjacent rings of single-ring stents 10, that is, the single-ring stents 10 and the connectors 20 are distributed at intervals along the axial direction of the vascular stent 100. It should be noted that in some embodiments, the connector 20 may not be provided between two adjacent rings of single-ring stents 10 connected by the membrane 30. The single-ring stent 10 has better bending resistance and support performance than the connector. When the vascular stent 100 is implanted into the diseased site, multiple single-ring stents 10 can be relied on to anchor and support at the diseased site to prevent the vascular stent 100 from shifting. The connector 20 has better bending performance and flexibility than the single-ring stent 10. When the vascular stent 100 is delivered in a curved blood vessel and placed in the curved blood vessel, multiple connectors 20 can be relied on for bending. The membrane 30 has high sealing performance. When the vascular stent 100 is implanted into the diseased site, the membrane 30 can cover the diseased area and seal the diseased area, preventing the blood in the aorta from entering the media of the blood vessel from the tear of the intima, and preventing the continuous separation of the intima and media of the blood vessel, thereby alleviating the disease.

[0073] Figure 2 Fig. Figure 3 shows a schematic three-dimensional structure diagram of the single-ring stent 10 of the present invention, Figure 2 and Figure 3 Fig. shows a front view of the single-ring stent 10 of the present invention. Please refer to

[0074] In the present invention, the single-ring stent 10 is a circular or approximately circular ring formed by bending and heat-treating a metal wire with a circular cross-section. While extending circumferentially, the single-ring stent 10 undulates axially in a wavy shape. The material for making the single-ring stent 10 is a shape memory alloy, such as nickel-titanium alloy (NiTi). The overall height H1 of the single-ring stent 10 ranges from 5 to 20 mm, such as 5 mm, 10 mm, 15 mm, or 20 mm; the overall diameter D1 of the single-ring stent 10 ranges from 10 to 50 mm, such as 10 mm, 20 mm, 30 mm, 40 mm, or 50 mm; the cross-sectional diameter d1 of the metal wire of the single-ring stent 10 ranges from 0.1 to 1 mm, such as 0.1 mm, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, or 1 mm.

[0075] In an alternative embodiment, the cross-section of the metal wire of the single-ring stent 10 can also be square, trapezoidal, or other suitable shapes. When the cross-section of the metal wire of the single-ring stent 10 is square, the diagonal dimension of the square is defined as d1, and its range is from 0.1 to 1 mm, such as 0.1 mm, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, or 1 mm.

[0076] In an alternative embodiment, the single-ring stent 10 can also be made by laser cutting a metal pipe and then expanding and shaping it through heat treatment. In an alternative embodiment, the single-ring stent 10 can also be made in one step by 3D metal printing.

[0077] Please refer to Figure 2 and Figure 3 , in the present invention, the single-ring stent 10 includes a wave crest 101, a wave trough 103, and a wave rod 102 connecting the wave crest 101 and the wave trough 103. One wave crest 101 and two adjacent wave rods 102 form a wave. The wave crest 101 and the wave trough 103 are relative. When the single-ring stent 10 is inverted axially, the wave crest becomes the wave trough, and the wave trough becomes the wave crest. The number of waves of a single-ring stent 10 is not fixed and should be set according to the values of the overall height H1 of the single-ring stent 10 and the overall diameter D1 of the single-ring stent 10 to conform to the aortic physiological and anatomical structure. As an example, the number of waves of a single-ring stent 10 is between 3 and 12, where Figure 2 shows a case where the number of waves of the single-ring stent 10 is 6.

[0078] In the present invention, the radius R of the transition fillet between the wave crest 101 or the wave trough 103 ranges from 0 to 5 mm, such as 0 mm (corresponding to the case where two adjacent wave bars 102 are directly connected without a fillet), 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. The several R values of a single-loop stent 10 are not necessarily the same, that is, the sizes of the several wave crests 101 or wave troughs 103 of the same single-loop stent 10 may be the same or different. The size of each R value should be set according to the requirements of functions such as the later crimping of the vascular stent 100. As an example, Figure 3 shows the case where the sizes of the several wave crests 101 or wave troughs 103 of the same single-loop stent 10 are the same.

[0079] In the present invention, the included angle (i.e., the angle α between two adjacent wave bars 102) of the wave crest 101 ranges from 10° to 70°, such as 10°, 20°, 30°, 40°, 50°, 60°, or 70°. The included angles α of the several wave crests 101 in the same single-loop stent 10 may be the same or different. The size of each α value should be set according to the requirements of functions such as the later crimping of the vascular stent 100.

[0080] Figure 2 And Figure 3 shows the case where all the wave bars 102 of the single-loop stent 10 are tangent to the adjacent wave crests 101 or wave troughs 103, and all the α values are the same acute angle (of course, it can also be an obtuse angle). It can be understood that the wave bar 102 and the wave crest 101 or wave trough 103 can also adopt one of the wave forms such as Figures 5a - 5c . Among them, in Figure 5a , the wave bar 102 is not tangent to the wave crest 101 or wave trough 103, and α is an acute angle, and the wave crest 101 or wave trough 103 presents a major arc shape; in Figure 5b , the wave bar 102 is not tangent to the wave crest 101 or wave trough 103, and α is an obtuse angle, and the wave crest 101 or wave trough 103 presents a minor arc shape; in Figure 5c , the wave crest 101 or wave trough 103 can be in the shape of "M" or "W", etc.

[0081] Please refer to Figures 2 - 4 as shown. In the present invention, the wave bar 102 is a straight bar connecting the wave crest 101 and the wave trough 103. The length L1 of the wave bar 102 ranges from 1 to 30 mm, and the length L1 of the wave bar 102 ranges from 1 to 30 mm, such as 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm. In the same single-loop stent 10, the lengths L1 of several wave bars 102 may be the same or different. As an example, Figure 3 shows the case where the lengths L1 of all the wave bars 102 of each single-loop stent 10 are equal. As an example, Figure 4The schematic structural diagram of the single-ring stent 10 is shown when the lengths of the wave rods 102 are unequal. When the lengths L1 of the wave rods 102 are unequal, the waves in the single-ring stent 10 present different sizes. The bending properties of the waves of different sizes are different, and it can better adapt to the curved blood vessels. It should be noted that in addition to the straight rod form, the form of the wave rod 102 can also be an "S"-shaped rod, a "Z"-shaped rod, etc.

[0082] Please refer to Figure 2 , in the present invention, the single-ring stent 10 further includes a tube sleeve 104, and the tube sleeve 104 can be a thin-walled metal sleeve with an inner diameter slightly larger than the cross-sectional diameter d1 of the wire of the single-ring stent 10. Figure 2 The situation where the single-ring stent 10 includes 2 tube sleeves 104 is shown. One function of a tube sleeve 104 is to connect the head and tail of the wire forming the single-ring stent 10. By clamping or welding, a wire is made into a ring with the head and tail connected. The other tube sleeve 104 is sleeved on the wave rod 102, the lead of the connecting body 20 is buried in the tube sleeve 104, and the tube sleeve 104 is clamped so that the tube sleeve 104 and the lead are fixed on the wave rod 102. The manufacturing material of the tube sleeve 104 is suitable metals such as stainless steel, NiTi, etc. It can be understood that only one tube sleeve 104 can be used to connect the head and tail of the wire of the single-ring stent 10, and the lead of the connecting body 20 is trimmed without burying it in the tube sleeve 104.

[0083] It can be understood that when the single-ring stent 10 is made by cutting or metal printing, the tube sleeve 104 is not required.

[0084] Such as Figure 6 shown, the relative positions of the multiple single-ring stents 10 in the blood vessel stent 100 can be the same or different. In Figure 6 the lower elliptical area, the wave peaks 101 of two adjacent single-ring stents 10 are arranged in a staggered manner. The wave peak 101 of one single-ring stent 10 is located between the two wave peaks 101 of another single-ring stent 10. For example, for two adjacent single-ring stents 10, the wave peak 101 of one single-ring stent 10 can be axially vertically opposite to the wave valley 103 of another single-ring stent 10; in Figure 6 the upper elliptical area, for two adjacent single-ring stents 10, the wave peak 101 of one single-ring stent 10 can also be axially inclined relative to the wave valley 103 of another single-ring stent 10, that is, the wave peak 101 of one single-ring stent 10 is located between the two wave valleys 103 of another single-ring stent 10. For example, the wave peaks 101 of two adjacent single-ring stents 10 are aligned.

[0085] Figure 7 The three-dimensional schematic diagram of the connecting body 20 of the present invention is shown, Figure 8 The front view plane schematic diagram of the connecting body 20 of the present invention is shown, Figure 9Shows a winding schematic diagram of the connecting body of the vascular stent of the present invention.

[0086] Please refer to Figures 7 - 9 , in the present invention, the connecting body 20 is composed of several cord-like flexible bodies. The several cord-like flexible bodies are wound around a plurality of single-ring stents 10 to play a role in connecting adjacent single-ring stents 10. At the same time, the several cord-like flexible bodies will also be intertwined to jointly form a connecting body 20. Among them, the cord-like flexible body is, for example, a metal wire, and the material of the connecting body 20 is a shape memory alloy, such as nickel-titanium alloy (NiTi). The axial cross-sectional dimension d2 of the metal wire used for the connecting body 20 is smaller than the axial cross-sectional dimension d1 of the metal wire used for the single-ring stent 10, and d1:d2 = 2-20, such as 2, 5, 8, 11, 14, 17, 20. The connecting body 20 includes a circumferential connecting body 21 and an axial connecting body 22.

[0087] Please refer to Figures 7 - 9 , in the present invention, the circumferential connecting body 21 includes a first circumferential connecting body 211 and a second circumferential connecting body 212. The first circumferential connecting body 211 is a metal wire that is wound around the valleys 103 or peaks 101 of the single-ring stent 10 in sequence in the circumferential direction. Through bending, winding, and heat treatment setting of the metal wire, its circumferential shape is the same as that of the single-ring stent 10, which is a circular or approximately circular ring. The first circumferential connecting body 211 can be a single-strand metal wire or a multi-strand twisted metal wire. The first circumferential connecting body 21 includes a first knot 2111 formed by winding around the peak 101 or valley 103 and a second knot 2112 that winds itself and is located between adjacent peaks 101 or valleys 103. The first knot 2111 can be any suitable knot form such as a Prusik knot, a single knot, a figure-eight knot, a double fisherman's knot, or a direct loop; the second knot 2112 can be any suitable knot form such as a Prusik knot, a single knot, a figure-eight knot, a double fisherman's knot, or a direct loop.

[0088] The number of the first knots 2111 on each first circumferential connecting body 21 is not limited, nor is it limited that they must be evenly distributed circumferentially, that is, the first knots 2111 may not be tied on some of the peaks 101 or valleys 103. The maximum number of the first knots 2111 is the same as the number of the peaks 101 or valleys 103, but the minimum number should not be less than half of the number of the peaks 101 or valleys 103 of each first circumferential connecting body 21.

[0089] The number of the second knots 2112 on a first circumferential connecting body 21 is not limited, that is, there may be no self-wound knots between adjacent peaks 101 or valleys 103, or there may be multiple knots. The number of the second knots 2112 should match the required shape of the axial connecting body 22.

[0090] The axial connecting body 22 is intertwined around the wave crest 101, the first knot 2111, the second knot 2112, the wave trough 103 and the first knot 2111. The axial connecting body 22 is formed by bending, winding and heat treatment shaping of a metal wire. The circumferential shape of the axial connecting body 22 is a circular or approximately circular ring or a semi-circular or approximately semi-circular arc that is adapted to the single-ring bracket 10. When the axial connecting body 22 is wound around the wave crest 101 or the wave trough 103, it needs to pass through the gap of the first knot 2111 to ensure that the axial connecting body 22 binds itself, the first knot 2111 and the wave crest 101 or the wave trough 103 together, so as to limit the sliding of the winding points of the first knot 2111 and the axial connecting body 22 on the single-ring bracket 10. The axial connecting body 22 needs to be wound through the gap of the second knot 2112 to limit the sliding of the axial connecting body 22 on the first circumferential connecting body 211.

[0091] As Figure 1 and Figure 7 shown, in the present invention, the axial connecting body 22 is arranged in a non-uniform distribution in the circumferential direction, and the axial connecting body 22 is provided in some regions in the axial direction, while the axial connecting body 22 is not provided in other regions. In other words, adjacent single-ring brackets 10 can be axially connected only in some regions, while not axially connected in other regions. The parts of the single-ring brackets that are not axially connected are in a free state in the axial direction.

[0092] It can be understood that in other embodiments, the non-uniform distribution of the axial connecting body 22 in the circumferential direction may also mean that the density of the axial connecting body 22 in the circumferential direction is inconsistent, with some regions being densely arranged and some regions being sparsely arranged. It should be noted that in the present invention, when the wave crest 101 or the wave trough 103 is Figures 5a - 5c in the shown form, it can better resist the sliding of the first knot 2111 on the single-ring bracket 10.

[0093] It should be noted that in the present invention, at the first knot 2111 or the second knot 2112 of the axial connecting body 22, in addition to the Figure 9 shown direct winding method, it can also be tied into knot forms such as Prusik knot, single knot, figure-eight knot, double fisherman's knot, etc. For example: when the first knot 2111 is a Prusik knot, the axial connecting body 22 can tie a reverse Prusik knot here to form an interpenetrating double Prusik knot. When the second knot 2112 is a single knot, the axial connecting body 22 can tie a single knot here to form a double knot.

[0094] It should be noted that in the present invention, the number and uniformity of the winding points of the axial connecting body 22 on the wave crest 101, the wave trough 103 or the circumferential connecting body 21 are not fixed, that is, winding may not be performed on some wave crests 101, wave troughs 103 or a certain section of the circumferential connecting body 21.

[0095] As shown in the figure Figure 9 As shown, the connecting body 20 includes two axial connecting bodies 22a and 22b. One axial connecting body 22b is an "N" shape with staggered heights, and the other axial connecting body 22a is a reverse "N" shape with staggered heights.

[0096] Figure 9 It shows a situation where the first knot 2111 is a Prusik knot and the second knot 2112 is, for example, a simple knot. The first knot 2111 is provided on each peak 101 or trough 103, and a second knot 2112 is provided between each adjacent peak 101 or trough 103. The axial connecting body 22 winds around each first knot 2111 and second knot 2112 once.

[0097] As Figure 9 shown, in the present invention, the second circumferential connecting body 212 is located between two adjacent first circumferential connecting bodies 211 and can be connected to the axial connecting body 22 in a circumferential direction by winding. When the axial connecting body 22 is provided in a partial area in the circumferential direction, the second circumferential connecting body 212 is also only arranged in the area corresponding to the axial connecting body 22.

[0098] In Figure 9 , the connecting body 20 includes three circumferential connecting bodies 21, namely two first circumferential connecting bodies 211 and one second circumferential connecting body 212. One first circumferential connecting body 211 winds around the peak 101 of the single-ring bracket 10 on one side, and the other first circumferential connecting body 211 winds around the trough 103 of the single-ring bracket 10 on the other side; one second circumferential connecting body 212 is located on the intermediate plane of the axial connecting body 22 in the axial direction, and it winds around the axial connecting body 22. Optionally, it can also be tied to the axial connecting body 22 in a suitable knotting manner.

[0099] It should be noted that in the present invention, the number and shape of the axial connecting bodies 22 between two adjacent single-ring brackets 10 are not limited Figure 9 to the situation shown. The number and shape of the axial connecting bodies 22 should match the required support performance and compliance performance of the vascular stent 100. As an example, the number of circumferential connecting bodies 21 between two adjacent single-ring brackets 10 is 2 - 5, that is, in addition to one first circumferential connecting body 211 wound around the opposite peak 101 and trough 103 of two adjacent single-ring brackets 10 on each side, there are 0 - 3 second circumferential connecting bodies 212 distributed in the axial direction of the axial connecting body 22. That is to say, in some embodiments, the connecting body may not be provided with the second circumferential connecting body 212. The number of axial connecting bodies 22 between two adjacent single-ring brackets 10 can be 1 - 3, and the shape can be an "N" shape, a reverse "N" shape, or a "Z" shape.

[0100] AsFigure 9 As shown, the connecting body 20 is in a grid form composed of a number of triangles with different orientations. It can be understood that according to the above-mentioned setting methods of the circumferential connecting body 21 and the axial connecting body 22, the final grid form of the connecting body 20 can also be Figures 10a - 10e the various grid forms shown. The grid form of the same connecting body 20 can be single or different in segments. The grid forms of several connecting bodies 20 on the same vascular stent 100 can be the same or different.

[0101] With the structural design of the connecting body 20 of the present invention, the circumferential connecting body 21 and the axial connecting body 22 form mutual limits to prevent the node from sliding on the wave rod of the stent.

[0102] For the connecting body of the existing bare stent, only the vertex of the stent ring of the single-ring stent can be used as the winding place of the node; while with the structural design of the connecting body 20 of the present invention, the circumferential connecting body 21 can be used as the winding point of the axial connecting body at various positions within 360° in the circumferential direction. The axial connecting body 22 has more node winding places, which enables the axial connecting body 22 to be only concentrated on one side of the vascular stent and be axially free on the other side of the vascular stent.

[0103] As Figure 1 shown, in the present invention, the film 30 is one of the components constituting the vascular stent 100, and the vascular stent 100 may include several films 30. The film 30 is a layer of flexible film material attached to the single-ring stent 10 or the connecting body 20. The material of the film 30 can be, for example, PET (polyester fiber, terylene) or EPTFE (polytetrafluoroethylene) and other materials. The film 30 is attached to at least one single-ring stent 10 or one connecting body 20, and at most to all the single-ring stents 10 and connecting bodies 20.

[0104] As Figure 11 shown, the setting position of the film 30 is optional and can be attached to different single-ring stents 10 or connecting bodies 20 of the vascular stent 100 as required. The film 30 can be attached to the outside, inside or both inside and outside of the single-ring stent 10 or the connecting body 20. The film 30 can be attached to the single-ring stent 10 or the connecting body 20 by any suitable method such as adhesion (such as hot melting), sewing, etc.

[0105] Next, the beneficial effects of the vascular stent 100 of the present invention will be elaborated by comparing it with the existing stents.

[0106] 1. The vascular stent 100 of the present invention has good bending performance, can obtain different support performance and compliance performance in the circumferential direction according to needs, and can better adapt to the curved vascular environment.

[0107] As Figure 12aAs shown, in some existing bare stents, the peaks and valleys of adjacent single-ring stents are connected by silk threads, resulting in poor bending performance. The overall stent has uniform circumferential support performance and compliance performance and cannot well adapt to the curved vascular environment. When the stent undergoes a large bend, due to the excessive pulling of the wave rods of adjacent single-ring stents at the large bend of the stent by the silk threads, the stent undergoes excessive bending towards the central axis at the small bend, resulting in distortion of the bending cross-section.

[0108] As Figure 12b shown, the vascular stent 100 of the present invention has good bending performance and can be segmented and designed with connectors 20 as needed to obtain different circumferential support performance and compliance performance, and can well adapt to the curved vascular environment. The part without the axial connector 22 can be used as the large bend side of the stent bend. Then, the stent part at the large bend is in a free state axially. At this time, only the parts of the stent at the small bend will overlap each other, so that excessive bending towards the central axis will not occur.

[0109] 2. The vascular stent 100 of the present invention can not only maintain the uniformity of the stent shape, but also obtain different circumferential support performance and compliance performance. The different circumferential support performance and compliance performance of the overall stent can better adapt to the vascular anatomical structure.

[0110] As Figure 13a shown, in some existing stents, since there is no circumferential connector as the winding point of the axial connector, the axial connector can only use the peaks and valleys of each ring stent as the connection points. In order to ensure the circumferential uniformity of the overall stent, the axial connectors must also be evenly distributed circumferentially on the single-ring stent, which also results in uniform circumferential support and compliance of the overall stent. If some axial connectors are removed, the free waves of the single-ring stent may undergo axial deformation due to external forces. For example, when an interventional operation is performed, the overall stent may not be completely placed properly and needs to be adjusted in position. If the stent is moved at this time, it is possible to cause the free waves to scratch on the inner wall of the blood vessel, resulting in axial deformation and damaging the blood vessel.

[0111] As Figure 13bAs shown in the figure, since the circumferential connector 21 of the vascular stent 100 of the present invention serves as the winding point of the axial connector 22, the axial connector 22 can be freely arranged circumferentially according to design requirements to obtain different circumferential support performance and compliance performance. At the same time, due to the limitation of the circumferential connector 21, the single-ring stent 10 has no absolute free wave and will not produce axial deformation. When the vascular stent 100 of the present invention is placed in the ascending aorta, the proximal end of the ascending aorta will produce a larger contraction than the distal end with the beating of the heart. Therefore, through the design and adjustment method of the circumferential connector 21 and the axial connector 22 of the present invention, the support performance of the proximal end of the vascular stent 100 can be reduced without changing the mechanical properties of the rest of the vascular stent 100, so as to better adapt to the systolic and diastolic of the proximal end of the ascending aorta.

[0112] 3. As Figure 14 and Figure 15 shown, the excellent bending performance of the local film covering and the stent of the vascular stent of the present invention enables the vascular stent 100 of the present invention to be used for the interventional treatment of Debakey type II without the need for branch vessel reconstruction and the dissection not involving the aortic arch.

[0113] At present, there are few vascular stents specifically used for the treatment of Debakey type II, especially for Debakey type II without the need for branch vessel 704 reconstruction and the dissection 705 not involving the aortic arch 702. Since the ascending aorta 701 is short and close to the heart, in order to prevent the vascular stent inserted into this part from falling off, the stent needs to have a certain length to span the aortic arch 702 and complete anchoring. If a traditional covered stent is used for interventional treatment, the polymer film will block the blood supply of the branch vessel 704 at the aortic arch 702. Therefore, it is necessary to open holes in the film 30 and complete the precise adaptation of the holes to the branch vessel 704, which greatly increases the difficulty of the surgical operation.

[0114] As Figure 14 and Figure 15 shown, the proximal end of the vascular stent 100 of the present invention is attached with a film covering 30, and this section can seal the dissection 705 rupture opening on the ascending aorta 701, achieving the purpose of treating Debakey type II dissection. The non-covered section 100a of the vascular stent 100 of the present invention spanning the aortic arch 702 can not only allow the free flow of blood from the thoracic aortic vessel to the branch vessel 704, but also prevent the dissection 705 rupture opening from expanding towards the aortic arch 702. At the same time, the vascular stent 100 of the present invention can design suitable single-ring stent 10 sizes and connector 20 sizes according to the interval of the branch vessels 704 of the aortic arch 702, so that the adjacent single-ring stents 10 are stuck on both sides of the bifurcation of the branch vessel 704, ensuring that there is no interference from the single-ring stent 10 or the connector 20 at the bifurcation of the branch vessel 704, and greatly guaranteeing the smooth flow of blood.

[0115] The vascular stent 100 of the present invention can also be precisely positioned. If the vascular area covered by the axial connector 22 has small branch blood vessels 704, the axial connectors 22 can be densely arranged in the part away from the bifurcation of the branch blood vessels 704, and the axial connectors can be sparsely arranged at the bifurcation of the branch blood vessels 704 to reduce the interference with the blood flow of the branch blood vessels and ensure smooth blood circulation.

[0116] In addition, the coating 30 attached to the distal end of the vascular stent 100 can relieve the pressure exerted by the free apex of the stent end on the inner wall of the blood vessel, thereby reducing the risk of intimal rupture.

[0117] 4. The vascular stent 100 of the present invention has better fatigue resistance and will not cause damage to the inner wall of the blood vessel.

[0118] Figure 16a The existing stent shown in the figure has no circumferential connector as the winding point of the axial connector. The axial connector is evenly distributed circumferentially on the single-ring stent, which also leads to uniform support and flexibility of the whole stent in the circumferential direction. When the whole stent is placed in a curved blood vessel, the whole stent on the inside is in a compressed state, and the whole stent on the outside is in a stretched state. Due to the transitional pulling of the outer axial connector on the outer side of the single-ring stent, the outer wave of the single-ring stent is subjected to tension and deforms such as buckling inward (see Figure 16a The area indicated by the circle in the middle). According to the basic knowledge of material mechanics, it can be known that the fatigue performance of the single-ring stent and the connector in this state is weakened. In the present invention, since the connector adopts a connector with different segmented designs, the above problem can be better solved. That is, an axial connector is set at the part without transition traction on the inside to connect multiple single-ring stents to ensure the continuity of the overall stent; the design of the axial connector is cancelled at the part where transition traction is generated on the outside to ensure the flexibility of the outer side of the overall stent, so that the vascular stent 100 has better fatigue resistance.

[0119] Figure 16b The prior art stent shown in the figure has no circumferential connector as the winding point of the axial connector, and the part of the axial connector located on the outside is cancelled. When the whole stent is placed in a curved blood vessel, the whole stent on the inside is in a compressed state, and the outer wave of the single-ring stent is completely in a free state, so the outer wave of the single-ring stent will be outwardly warped (see Figure 16b The area indicated by the middle circle), at this time, the outward-warped outer wave will cause damage to the inner wall of the blood vessel, especially the endothelial layer of the blood vessel in the pathological state is easily scratched.

[0120] like Figure 16cAs shown, the vascular stent 100 of this patent is provided with an axial connector 22 in the inner region, and no axial connector 22 is provided in the outer region. That is, the outer waves of the single-ring stent 10 will not be excessively pulled by the connector 20. Due to the limitation of the circumferential connector 21, the outer waves will not completely float and warp outward, which neither affects the fatigue performance of the overall stent nor causes damage to the inner wall of the blood vessel.

[0121] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or by other devices, systems, components, methods, parts, materials, elements, etc. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0122] It should also be understood that one or more of the elements shown in the drawings may also be implemented in a more separated or more integrated manner, or even removed because they are inoperable in some cases or provided because they may be useful for a particular application.

[0123] Additionally, unless otherwise clearly specified, any marked arrows in the drawings should be considered exemplary only and not limiting. Furthermore, unless otherwise indicated, the term "or" as used herein generally intends to mean "and / or". In cases where the ability to provide separation or combination is unclear, the combination of components or steps will also be considered to have been specified.

[0124] The above description of the embodiments shown in the present invention (including the content in the abstract of the specification) is not intended to be exhaustive or to limit the present invention to the precise forms disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, as will be recognized and understood by those skilled in the art, various equivalent modifications are possible within the spirit and scope of the present invention. As noted, these modifications can be made to the present invention in accordance with the above description of embodiments of the present invention, and these modifications will be within the spirit and scope of the present invention.

[0125] The systems and methods have been generally described herein to facilitate understanding of the details of the present invention. Additionally, various specific details have been given to provide an overall understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or by using other devices, systems, fittings, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusing aspects of embodiments of the present invention.

[0126] Accordingly, while the present invention has been described herein with reference to its specific embodiments, modifications, various changes and substitutions are also within the above disclosure, and it should be understood that in some cases, some features of the present invention will be employed without corresponding use of other features, without departing from the scope and spirit of the claimed invention. Therefore, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms used in the following claims and / or to the specific embodiments disclosed as the best mode contemplated for carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the present invention will be determined only by the appended claims.

Claims

1. A vascular stent, characterized in that, comprising: a plurality of single - loop stents, arranged at intervals along the axis, while the single - loop stents extend circumferentially, they undulate axially in a wavy shape; a plurality of connectors, adjacent two single - loop stents are connected by the connectors; wherein, the connector includes two annular first circumferential connectors and at least one axial connector; one of the first circumferential connectors successively winds around the wave crests of one of the adjacent two single - loop stents in the circumferential direction, and the other first circumferential connector successively winds around the wave troughs of the other of the adjacent two single - loop stents in the circumferential direction. The first circumferential connector includes a first knot formed by winding around the wave crest or the wave trough and a second knot formed by its own winding and located between adjacent wave crests or wave troughs; the axial connector is located between two adjacent first circumferential connectors. While the axial connector extends circumferentially, it interweaves and winds around the wave crest, the first knot, the second knot, the wave trough and the first knot to limit the sliding of the winding points of the first knot and the axial connector on the single - loop stent, and to limit the sliding of the axial connector on the first circumferential connector, and the axial connector is unevenly distributed in the circumferential direction.

2. The vascular stent according to claim 1, characterized in that, the material of the single - loop stent is shape - memory alloy.

3. The vascular stent according to claim 1, characterized in that, the single - loop stent includes a wave crest, a wave trough and a wave rod connecting the wave crest and the wave trough, and the wave rod is tangent or non - tangent to the wave crest / wave trough.

4. The vascular stent according to claim 1, characterized in that, the relative positions of the single - loop stents of the vascular stent are the same or different.

5. The vascular stent according to claim 1, characterized in that, the material of the plurality of connectors is shape - memory alloy.

6. The vascular stent according to claim 1, characterized in that, the plurality of connectors are in a mesh form.

7. The vascular stent according to claim 1, characterized in that, the vascular stent further includes a membrane, and the membrane is attached to the single - loop stent or the plurality of connectors.

8. The vascular stent according to claim 1, characterized in that, the vascular stent further includes a second circumferential connector, which is located between two adjacent first circumferential connectors and winds around the axial connector in the circumferential direction.

9. The vascular stent according to claim 8, characterized in that, the first circumferential connector is a single - strand metal wire or a multi - strand twisted metal wire; the second circumferential connector is a single - strand metal wire or a multi - strand twisted metal wire.

10. The vascular stent according to claim 1, characterized in that, the number of the first knots of one of the first circumferential connectors is greater than or equal to half of the number of the wave crests / wave troughs of one single - loop stent.

11. The vascular stent according to claim 1, characterized in that, the axial connector includes at least two. One axial connector is in an "N" shape, and the other axial connector is in a reverse "N" shape.

12. The vascular stent according to claim 1, characterized in that, the axial connectors are distributed in a partial circumference of the vascular stent.

13. The vascular stent according to claim 1, characterized in that, the axial cross-sectional dimension of the metal wires of the plurality of connectors is smaller than the axial cross-sectional dimension of the wire of the single-ring stent.

14. The vascular stent according to claim 13, characterized in that, the ratio of the axial cross-sectional dimension of the wire of the single-ring stent to the axial cross-sectional dimension of the metal wires of the plurality of connectors is between 2 and 20.

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