A balloon-constrained stent with cutting function and a vascular dilation device using the stent

Abstract

A balloon restraint stent with cutting function, comprising a main body area, the main body area having a first state for shrinking together with a balloon and a second state for expanding together with the balloon, the main body area comprising a restraint ring and a cutting section; and an implantable vascular expansion device with cutting function, comprising a balloon, and also comprising the balloon restraint stent as described above, the balloon is wrapped and restricted by the restraint ring to form alternating raised annular bands and recessed annular bands after expansion. The present invention has a simple structure and can achieve better dredging effect compared with the prior art. The restraint stent has both restraint and cutting functions. The treatment process of the vascular expansion device is controllable and predictable, which greatly improves the treatment effect, reduces the probability of damage to blood vessels and complications, and improves the treatment effect of balloon angioplasty. It has guiding significance for the treatment of complex plaque lesions and is worthy of promotion and use in this field.

Description

Technical Field

[0001] The invention relates to the technical field of angioplasty surgery, in particular to a balloon restraint stent with a cutting function and a vascular dilation device using the stent. Background Art

[0002] Balloon angioplasty is one of the most commonly used treatments for cardiovascular diseases. Traditional balloon catheters are made into cylindrical balloons of different diameters and lengths according to the size of the patient's blood vessels and the length of the lesion. The working principle is: using a delivery system, a balloon dilation catheter is placed at the lesion. After the balloon is inflated, the blood vessel is dilated to expand the lumen.

[0003] Traditional balloon angioplasty is often accompanied by vascular damage. For example, during the balloon expansion process, the diameter of the proximal and distal ends of the balloon is larger than the diameter of the middle part of the balloon, which is the "dog bone effect". This causes the blood vessels in contact with the two ends of the balloon to over-expand, causing damage to the vascular wall and causing the longitudinal elongation of the balloon to accelerate vascular dissection (>30%). It can also cause acute vascular occlusion (5%~12%) and postoperative restenosis (50%) at the lesion site. Vascular dissection, acute vascular occlusion, and vascular wall damage are all vascular trauma caused by traditional balloon angioplasty, and traditional balloon angioplasty itself is still not effective enough in clearing the lumen.

[0004] In order to eliminate the "dog bone effect", it is of great significance to design a PTCA / PTA balloon with a constrained stent. Existing balloons have begun to combine constrained stents to solve this problem. For example, the patent document with patent number CN102939125A discloses an angioplasty balloon with an elastic restraint structure. When the balloon is expanded, the elastic restraint structure draws a uniformly arranged grid area on the balloon to form a "pillow" pattern. The balloon has a restrictive expansion shape and can reduce vascular damage. However, it is found in clinical applications that the balloon catheter formed by this scheme will greatly reduce the force of the plaque in the lumen, but it cannot effectively compress and remove the plaque, which greatly reduces the effect of dredging blood vessels. The present invention focuses on seeking a more optimized structure on the existing PTCA / PTA balloon to solve the aforementioned technical problems at the same time. Summary of the invention

[0005] One of the technical objectives of the present invention is to provide a balloon-constrained stent with a cutting function, which can limit the expansion of the balloon, so that its expansion rate and size can be effectively controlled and kept stable, reducing its damage to blood vessels, and at the same time cutting plaques, which can effectively dredge blood vessels compared with the existing technology.

[0006] The specific technical solution of the balloon restraint stent of the present invention is as follows: a balloon restraint stent with a cutting function, comprising a main body area, the main body area having a first state for being crumpled together with the balloon and a second state for being expanded together with the balloon, the main body area comprising a restraint ring and a cutting segment; the restraint rings are arranged at intervals along the length direction of the restraint stent and form interval spaces, the restraint rings themselves are used to compress a part of the balloon body and limit the complete expansion of the balloon, and the interval space is used for the remaining part of the balloon body to expand and bulge outward; a plurality of cutting segments are connected between two adjacent restraint rings, and the cutting segments are used to conform to the surface of the remaining part of the bulging balloon body and be adhered.

[0007] The balloon restraint stent is made of a retractable memory material and can expand / contract along with the expansion / contraction of the balloon. The main body area is correspondingly wrapped outside the expansion body of the balloon. The restraint ring mainly restricts the complete or excessive expansion of the balloon catheter. The balloon expands in a restricted manner as a whole, effectively avoiding the "dog bone" effect and reducing trauma to diseased blood vessels. The axially spaced restraint rings form a circle of convexities and a circle of concavities alternating circumferentially when the balloon expands, ensuring that there is still sufficient force on the vascular plaque to reshape the plaque. When the balloon expands, the cutting section clings to the surface of the convex part of the balloon, follows the balloon to exert force on the plaque, compresses the vascular plaque, and cuts and fragments the vascular plaque at the same time, thereby achieving the purpose of effectively unblocking the blood vessels.

[0008] Preferably, the relative arrangement relationship of the cutting segments between two adjacent confinement rings includes an interval arrangement and / or a cross arrangement.

[0009] The cutting segments can be arranged horizontally or obliquely at intervals, and the spacing setting can be selected to be uniform or non-uniform; or the cutting segments can be arranged obliquely and crosswise, so that a variety of adaptive and targeted cutting methods can be provided according to the actual lesion conditions, effectively solving the problem of complex vascular plaque lesions.

[0010] Preferably, the cutting segment includes a straight segment and / or a curved segment.

[0011] The processing of the straight cutting segment is relatively simple and the effect is relatively stable; while the curved cutting segment has more cutting contact surfaces, providing a better plaque cutting effect.

[0012] Preferably, a cutting portion is provided on the cutting section.

[0013] Preferably, the cutting portion is a micro blade.

[0014] Compared with the single cutting section body, the micro blade can more effectively and easily cut off the elasticity and fiber continuity of the tube wall at the lesion site, reduce the migration of plaques, and thus achieve a therapeutic effect.

[0015] Preferably, the cutting portion is a plurality of convex teeth.

[0016] Compared with the single cutting segment body, each convex tooth can cut off continuous plaques more easily and effectively, and the tooth grooves between the convex teeth provide space for closing elastic recovery, thereby reducing damage to the blood vessel wall.

[0017] Preferably, the confinement ring and the cutting section are connected in a fixed manner and / or a movable manner.

[0018] The relatively fixed connection method is easier to implement and has a more stable effect, but it cannot effectively deal with complex plaque lesions; the relatively movable connection method allows the cutting segment to move relatively on the restraint ring. For complex plaque lesions that cannot be cut in one go, mobile cutting can be achieved, thereby improving the therapeutic effect of balloon surgery.

[0019] Preferably, the fixed connection method is welding, gluing or hot-melt connection.

[0020] Preferably, the fixed connection method is that the restraint ring and the corresponding cutting segment have an intersection and are tied and connected at the intersection by a connecting line.

[0021] The binding connection can avoid residual stress at the connection point as in an integrally formed connection, thereby reducing the risk of structural damage. The binding connection can disassemble and assemble the cutting section, and the restraint ring is separated from the cutting section to achieve modular processing, improve production efficiency, and reduce production costs.

[0022] Preferably, the movable connection method is that there is an intersection between the constraint ring and the corresponding cutting segment and a connecting key is connected to the cutting segment at that intersection, and a sleeve space for the constraint ring to pass through is formed between the connecting key and the cutting segment so that the connecting key is relatively sleeved on the constraint ring.

[0023] The connecting key enables a non-fixed connection between the constraint ring and the cutting segment, and the cutting segment can move circumferentially along the constraint ring to achieve targeted mobile cutting, effectively dealing with complex plaques.

[0024] Preferably, the restraining stent further comprises a balloon end connection area.

[0025] The balloon end connection area is connected to the two ends of the main body area, and is used for fixed connection with the distal end and the proximal end of the balloon.

[0026] Another technical purpose of the present invention is to provide a vascular dilation device using the constrained stent, in which the expansion rate and expansion size are controlled and ultimately remain stable, causing less damage to the blood vessels. During the expansion process, the force exerted on the plaque is sufficient, and the plaque can be cut at the same time, effectively reshaping and breaking up the plaque, thereby greatly improving the effect of vascular dredging.

[0027] The specific technical solution of the vascular dilation device of the present invention is as follows: an implantable vascular dilation device with a cutting function, comprising a balloon and a balloon restraint bracket as described above, wherein the balloon is wrapped and restrained by the restraint ring to form alternating raised annular bands and recessed annular bands after expansion, and the cutting section conforms to and adheres to the surface of the raised annular band of the balloon.

[0028] The restraining ring limits the expansion of the balloon and forms convex and concave shapes on the balloon between adjacent restraining rings, which can not only effectively reshape the plaque but also reduce vascular damage. On this basis, the cutting segment is tightly attached to the surface of the expanded balloon and has a cutting effect, which can effectively cut the plaque.

[0029] The technical advantage of the present invention is that the restraining stent and the vascular expansion device have a simple structure and can achieve a better dredging effect compared with the prior art. The restraining stent has both restraining and cutting functions to ensure that the balloon expands gently and evenly, avoiding radial force and axial force that cause damage to the blood vessel wall due to too fast and excessive expansion. The restraining ring is used to separate the balloon into a raised annulus and a recessed annulus to ensure that the balloon has sufficient force on the plaque, and the cutting segment is used to cut and fragment the plaque in a targeted manner. The treatment process of the vascular expansion device is controllable and predictable, which greatly improves the treatment effect, reduces the probability of damage to the blood vessels and complications, improves the treatment effect of balloon angioplasty, has guiding significance for the treatment of complex plaque lesions, and is worthy of promotion and use in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the restraining stent in a first state when it is collapsed according to an embodiment of the present invention (the balloon is schematically drawn with separation);

[0031] Figure 2 It is a schematic diagram of the structure of the restraint stent in a second state when it is expanded according to an embodiment of the present invention (the balloon is schematically drawn separately);

[0032] Figure 3 A schematic diagram of an arrangement of a restraining ring and a cutting segment according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the binding connection between the restraining ring and the cutting section according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the movable connection between the restraining ring and the cutting section according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the cutting portion of an embodiment of the present invention being a micro blade;

[0036] Figure 7 This is a schematic diagram of the structure of the cutting portion of an embodiment of the present invention as a convex tooth;

[0037] The names of the parts corresponding to the numbers in the figure are: 1-main body area, 2-constraint ring, 3-cutting section, 31-micro blade, 32-convex teeth, 4-connecting line, 5-connecting key, 6-balloon, 7-balloon connecting area, 71-transition part, 72-end head. DETAILED DESCRIPTION

[0038] The present invention will be further described below by means of specific embodiments in conjunction with the accompanying drawings:

[0039] See Figure 1 , an embodiment of a balloon restraint stent with cutting function, an embodiment of an expansion device with a balloon 6 is a restraint stent wrapped with a balloon 6. The restraint stent includes a main body area 1 and a balloon 67, and the balloon 67 includes a transition portion 71 and an end portion 72. The main body area 1 has a first state for shrinking together with the balloon 6 and a second state for expanding together with the balloon 6, and the main body area 1 includes a restraint ring 2 and a cutting segment 3; the restraint ring 2 is arranged at intervals along the length direction of the restraint stent and forms a spacing space, the restraint ring 2 itself is used to compress a part of the body of the balloon 6 and limit the full expansion of the balloon 6, and the spacing space is used for the remaining part of the body of the balloon 6 to expand and bulge outward; a plurality of cutting segments 3 are connected between two adjacent restraint rings 2, and the cutting segments 3 are used to conform to the surface of the remaining part of the body of the balloon 6 after the bulge and to be covered. The balloon 6 is wrapped and restricted by the restraint ring, and after expansion, it forms an alternating convex ring belt and a concave ring belt, and the cutting segment conforms to the surface of the convex ring belt of the balloon 6. The transition part 71 is composed of a memory axial rod segment, and generally, two of them can be selected as shown in the schematic diagram of this embodiment; the end part 72 is composed of a memory circumferential bending rod segment, and generally, two of them can be selected as shown in the schematic diagram of this embodiment. The left and right sides of the transition part 71 are respectively connected to the outermost restraining ring 2 and the end part 72.

[0040] Figure 1 To constrain the shrinkage state of the stent, Figure 2 yes Figure 1In the expanded form, the constraint rings 2 are wavy and arranged at intervals in the axial direction. The cutting segments 3 are connected between the constraint rings 2. The cutting segments 3 can be straight or curved. The crests / troughs of the constraint rings 2 are generally the connection points with the cutting segments 3. The crests / troughs of adjacent constraint rings 2 can correspond to each other one by one or be staggered so that the connected cutting segments 3 can be arranged horizontally or obliquely. The relative arrangement relationship between the cutting segments 3 can be arranged at intervals or crosswise. Figure 1 , Figure 2 As shown, the cutting segments 3 are arranged at intervals in an oblique manner. Of course, the arrangement of the cutting segments 3 in different intervals on the restraining bracket may also be different, such as Figure 3 As shown, both horizontal spacing arrangement and oblique spacing arrangement exist, and they can be set and manufactured according to actual processing needs. Curved, obliquely set, and cross-arranged cutting segments 3 can often provide relatively larger cutting contact areas and cutting capabilities, and can cope with more complex lesions. Further, conventional regularity or customized irregular spacing or cross-arrangement can be selected. In fact, according to the lesion condition, a constrained stent with different cutting segments 3 can be manufactured and selected to provide a variety of cutting methods, which is of great significance for solving complex vascular plaque lesions.

[0041] The cutting section 3 is provided with a cutting part. The material of the restraining stent is metal or medical polymer material. When there is no cutting part, the cutting section 3 itself can complete the cutting of the plaque during use, but the setting of the cutting part can further improve the cutting ability. The cutting part can be optionally provided with a medical micro blade 31 on the cutting section 3, such as Figure 6 . The connection method of the micro blade 31 and the cutting section can be simple, such as gluing or snap connection. Compared with the single cutting section 3, the micro blade 31 can more effectively and easily cut off the elasticity and limiting continuity of the lesion site, and reduce the migration of plaques. The inventor has also tried to set a micro blade 31 on the balloon 6 of this structure, but after testing, it was found that the micro blade 31 should not be set on the surface of the balloon 6. In the structure of this scheme, in order to enable the balloon 6 to have sufficient force on the plaque after expansion compared with the prior art, there is a distinction between a raised annulus and a recessed annulus. However, if a micro blade 31 is also set on the balloon 6, excessive cutting will occur, which may cause greater damage to the inner wall of the blood vessel.

[0042] The cutting portion can also be designed in the shape of a convex tooth 32, preferably a triangular pyramid, such as Figure 7 Each convex tooth 32 can be connected to the cutting section by bonding, welding or hot-melt forming, and each convex tooth 32 has a cutting function and can cut off continuous plaques. The tooth groove between two convex teeth 32 provides space for the elastic recovery of the vessel wall, thereby reducing damage to the vessel wall.

[0043] There are two ways to connect the restraining ring 2 and the cutting section 3: fixed connection and movable connection, which can be selected according to the condition of the lesion. The more commonly used fixed connection methods are welding, gluing and hot melt connection, which are more conventional and have better structural strength and connection effect. In addition, there are binding connections, such as Figure 4 Specifically, the restraining ring 2 and the corresponding cutting section 3 have an intersection and are connected by a connecting line 4 at the intersection. The connecting line 4 can be disassembled. The disassembly can be done by directly cutting it, or by tying it in a certain binding method in advance and then untying it. The existing technology can achieve this. In this way, modular processing of the restraining ring 2, the cutting section 3, and the connecting line 4 can be achieved, the production efficiency can be improved, and the disassembly and replacement can be carried out, which reduces the use cost in disguise. The binding connection can also avoid the residual stress caused by the integral molding type fixed connection, thereby reducing the risk of structural failure.

[0044] Activity connection method such as Figure 5 As shown, the constraint ring 2 and the corresponding cutting segment 3 intersect at an intersection and a connecting key 5 is connected to the cutting segment 3 at that intersection, and a sleeve space for the constraint ring 2 to pass through is formed between the connecting key 5 and the cutting segment 3 so that the connecting key 5 is relatively sleeved on the constraint ring 2, and the connecting key 5 is fixedly connected to the cutting segment 3 or detachably connected (similar to the aforementioned connecting line 4, which can be wound and then cut or untied). This method also has the advantages mentioned in the binding connection method, and the cutting segment 3 can also move circumferentially along the constraint ring 2 to realize the mobile cutting function, which is aimed at solving complex vascular plate lesions.

[0045] The sizes of the restraint bracket and the balloon 6 can be formulated in different specifications according to the size of the blood vessel. The maximum diameter of the restraint bracket after expansion is smaller than the maximum diameter of the balloon 6 after expansion. The expansion of the balloon 6 is restricted, which effectively avoids the "dog bone" effect. Before the expansion device is expanded, the balloon 6 is in a wrinkled state, and the restraint bracket is also in a wrinkled first state. At this time, the restraint bracket is tightly wrapped around the surface of the balloon 6, so that the diameter of the balloon 6 is as small as possible in the wrinkled state, and the restraint bracket and the balloon 6 catheter can be inserted or withdrawn from the blood vessel together. After the balloon 6 and the constraining stent are expanded, the balloon 6 protrudes from the space between the constraining rings 2 to form a protruding annulus, and the balloon 6 at the constraining ring 2 is restricted to form a concave annulus relatively. The protruding annulus provides sufficient and appropriate support to the inner wall of the blood vessel and the force on the plaque. The blood vessel wall is evenly stressed and in a good open state. While the blood vessel is evenly and gently expanded, the damage to the blood vessel is smaller than that caused by the traditional balloon 6 surgery. The concave annulus forms a gap space, and the microvascular tissue flow provides a channel, allowing the intravascular tissue to slowly reconstruct, promote wound healing, reduce and prevent restenosis, and eliminate the risk of possible late thrombosis. In addition, the cutting segment 3 will not compress the surface of the balloon 6 during the expansion process, until it is finally fully expanded, and it is compliantly attached to the surface of the balloon 6. It is also OK to have a certain gap. It can be understood that the cutting segment 3 is an arc segment along the surface of the expanded balloon 6. It will not be responsible for compressing the surface of the balloon 6 to form a concave annulus like the traditional balloon 6 stent, so as to weaken the final force of the balloon 6 on the plaque or the blood vessel wall. On this basis, the cutting segment 3 will effectively cut the plaque, open the blocked blood vessels, and promote blood circulation. The cutting segment 3 will play a certain cutting effect during the expansion process, mainly after the expansion is completed, the plaque is completely cut. The overall position of the balloon catheter can be adjusted according to the actual pathological condition to optimize the cutting. In addition, the surface of the balloon 6 and the constrained stent can be coated with a drug-loaded coating, such as sirolimus, paclitaxel, etc., which can inhibit smooth muscle cell proliferation and reduce the probability of restenosis of the blood vessel. This technical solution greatly improves the treatment effect and reduces the damage to the blood vessels, that is, the incidence of complications.

Claims

1. A balloon-constrained stent with cutting function, comprising a main body region (1), wherein the main body region (1) has a first state for being collapsed together with a balloon and a second state for being expanded together with the balloon, characterized in that: The main body area (1) comprises a restraining ring (2) and a cutting section (3); the restraining rings (2) are arranged at intervals along the length direction of the restraining stent to form a spacing space, the restraining ring (2) itself is used to compress a part of the balloon body to limit the balloon from fully expanding, and the spacing space is used to allow the remaining part of the balloon body to expand and bulge outward; a plurality of cutting sections (3) are connected between two adjacent restraining rings (2), and the cutting sections (3) are used to conform to the surface of the remaining part of the balloon body after the bulge to be attached; The cutting section (3) is provided with a cutting portion; The cutting portion is a tooth groove; The cutting segment (3) comprises a straight segment and / or a curved segment; The cutting section (3) will not exert pressure on the surface of the balloon during the expansion process, and will only adhere to the surface of the balloon in a compliant manner after the balloon is fully expanded.

2. The balloon-restrained stent with cutting function according to claim 1, characterized in that: The relative arrangement relationship of the cutting segments (3) between two adjacent constraint rings (2) includes an interval arrangement and / or a cross arrangement.

3. The balloon-restrained stent with cutting function according to claim 1, characterized in that: The connection mode between the restraining ring (2) and the cutting section (3) includes a fixed connection and / or a movable connection.

4. The balloon-restrained stent with cutting function according to claim 3, characterized in that: The fixed connection method is welding, gluing or hot-melt connection.

5. The balloon-restrained stent with cutting function according to claim 3, characterized in that: The fixed connection method is that the restraining ring (2) and the corresponding cutting section (3) have an intersection and are tied and connected at the intersection via a connecting line (4).

6. The balloon-restrained stent with cutting function according to claim 3, characterized in that: The movable connection method is that the constraint ring (2) and the corresponding cutting section (3) have an intersection and a connecting key (5) is connected to the cutting section (3) at the intersection, and a sleeve space for the constraint ring (2) to pass through is formed between the connecting key (5) and the cutting section (3), so that the connecting key (5) is relatively sleeved on the constraint ring (2).

7. An implantable vascular dilation device comprising a balloon-constrained stent with cutting function according to any one of claims 1 to 6, comprising a balloon (6), characterized in that: The balloon (6) is wrapped and restricted by the restraining ring (2) to form alternately arranged raised ring bands and recessed ring bands after expansion, and the cutting section (3) conforms to and adheres to the surface of the raised ring band of the balloon (6).

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