Drug carrying device capable of achieving continuous perfusion

Abstract

The utility model provides a drug loading device capable of continuous perfusion, which comprises a balloon dilatation catheter, a drug covered stent and a guide recovery catheter which are connected in sequence, the drug covered stent comprises a self-expanding base stent, a balloon component is arranged in the base stent, a covering film is arranged on the surface of the base stent, and the balloon component is connected with the guide recovery catheter. A medicine coating is arranged on the surface of the covering film, the base body support comprises a main body section capable of expanding in the radial direction, the two ends of the main body section are connected with fixing sections through connecting sections, and the balloon assembly is arranged in the main body section and fixed through the fixing sections. According to the embodiment of the utility model, the medicine placing time can be prolonged, so that the medicine can be better absorbed; meanwhile, the medicine loss of the medicine in the release process can be reduced, the harm of the medicine to other visceral organs due to the blood flow flushing effect is reduced, and the transfer rate of the medicine to blood vessels is increased; and as the placement time can be prolonged, the device can be used as a treatment device for vascular perforation.

Description

Technical Field

[0001] The utility model relates to the technical field of drug-carrying devices, and more specifically, to a drug-carrying device capable of continuous perfusion. Background Technique

[0002] Arteriosclerosis obliterans is mainly caused by atherosclerotic stenosis or occlusion of the arterial lumen. Endovascular treatment, as a minimally invasive method, especially for patients who are old, weak, or have other diseases and cannot tolerate the trauma of arterial bypass surgery, can be the first choice. Drug-coated balloons are an effective strategy for interventional treatment. Although drug-coated balloons avoid the permanent implantation of stents, they only temporarily displace plaques and carry the risks of elastic recoil, residual stenosis, and severe restrictive flow dissections.

[0003] To solve the above problems, more and more stents that can continuously provide high radial support force are being applied clinically. However, the continuous inflammatory response caused by stent implantation can lead to the proliferation of smooth muscle cells, further increasing the risk of in-stent restenosis. In this way, the inflammation caused by the stent and stent fracture together affect the long-term patency rate after surgery.

[0004] To address the intimal hyperplasia caused by vascular injury resulting from traditional endovascular treatment, drug-coated balloons have gradually become an important means for treating femoral-popliteal arteries, infra-popliteal arteries, and coronary arteries in recent years. In particular, they are used in percutaneous transluminal coronary angioplasty, which involves puncturing the femoral artery to send a balloon catheter to the coronary artery stenosis lesion and pressurizing and expanding it to increase the blood vessel diameter and improve myocardial blood supply.

[0005] However, current drug-coated balloons also have certain limitations. For example, when a drug-coated balloon is opened and releases drugs in an artery, it can block the arterial blood vessel and interrupt blood flow, which may cause ischemia of the arterial blood vessel. Therefore, the balloon inflation time is about 1 minute, and the absorption of drugs by the arterial wall is insufficient. In addition, part of the drugs will be washed away by the blood flow during the release process of the balloon, so the actual amount of drugs transferred to the blood vessel wall is low, and it is difficult to achieve the expected effect. Finally, existing drug-coated balloons cannot be used as an indication for treating vascular perforation.

[0006] Traditional balloon angioplasty is often accompanied by vascular injuries. For example, during the balloon dilation process, the diameters of the proximal and distal ends of the balloon are larger than that of the middle part of the balloon, namely the dog-bone effect, which causes the blood vessels contacted by both ends of the balloon to be over-dilated, resulting in damage to the blood vessel wall and accelerating the longitudinal elongation of the balloon to cause vascular dissection (>30%), and at the same time, it can trigger acute vascular occlusion (5%-12%) at the lesion site and restenosis after surgery (50%). Currently, the main support strength of the constrained balloon basically meets the requirements, but there are still some deficiencies. (1) During the balloon inflation process, the metal mesh structure will twist along with the balloon body, resulting in uneven concave-convex structures on the balloon surface; (2) The constrained balloon itself has poor flexibility, resulting in poor ability to adapt to blood vessels when implanted at the lesion site; (3) After the balloon deflates, the metal mesh has poor performance in rebounding the balloon, making it difficult to withdraw the whole from the body. Summary of the Invention

[0007] In view of this, the present invention aims to provide a drug delivery device with sustainable perfusion to solve the above technical problems in the prior art.

[0008] One aspect of the present invention provides a drug delivery device with sustainable perfusion, including a balloon dilation catheter, a drug-coated stent, and a guiding and retrieving catheter connected in sequence. The drug-coated stent includes a self-expandable matrix stent. A balloon assembly is arranged inside the matrix stent. A film is arranged on the surface of the matrix stent, and a drug coating is arranged on the surface of the film. The matrix stent includes a radially expandable main body section. Both ends of the main body section are connected to a fixed section through a connecting section. The balloon assembly is arranged inside the main body section and fixed through the fixed section.

[0009] In some embodiments, the main body section adopts a pipe network type (metal mesh) structure, which includes a plurality of main body units. Adjacent main body units are connected through a connecting member, and the connecting member is an asymmetric hippocampal connecting rod.

[0010] In some embodiments, the main body unit includes a plurality of first main body units located at the middle position and second main body units located at both side end positions. The first main body unit adopts a structure in the shape of a quasi-sine wave. Each first main body unit is arranged along the circumferential direction of the main body section, and a plurality of first main body units are arranged in sequence along the axial direction of the main body section. The second main body unit is arranged along the circumferential direction of the main body section, and the second main body unit is connected to the fixed section through the connecting section.

[0011] In some embodiments, the first main body unit has a tip. The tips of two adjacent first main body units are connected through the connecting member. The tip of the second main body unit and the tip of the adjacent second main body unit are connected through the connecting member. The connecting members are distributed at intervals along the circumferential direction or the axial direction.

[0012] In some embodiments, the asymmetric hippocampal connecting rod includes a head, a middle part, and a tail. The head and the tail are connected to two different first main body units. The head and the tail are curled. The head has a first arc facing a first direction, and the tail has a second arc facing a second direction. The orientations of the first arc and the second arc are opposite.

[0013] In some embodiments, the head and the tail are of an n-shaped structure, and there is a certain arc connection between the head and the tail and the middle part.

[0014] In some embodiments, the middle part is of a gradient structure. The middle part includes a back and a belly. The width gradually increases from the head to the belly and gradually decreases from the belly to the tail.

[0015] In some embodiments, the fixed section is an annular structure composed of V-shaped structural units arranged continuously in the radial direction.

[0016] In some embodiments, the connecting section is a straight connecting rod or a wavy connecting rod.

[0017] In some embodiments, the connecting section includes a connecting arm, and a tantalum bead connected to the fixed section is arranged at the end of the connecting arm.

[0018] In some embodiments, the connecting section adopts a spring structure, and the spring structure is arranged in a spring shape by winding one end of a developing filament around the head end of the fixed section.

[0019] In some embodiments, a barbed structure in the shape of a 7 is provided on the main body unit. It includes a connecting rib connected to the main body unit and a barbed part. The connecting rib is of a straight rod structure. The barbed part is made of a developing material and is connected to the connecting rib. The barbed part forms a predetermined angle with the connecting rib and is parallel to the main body unit.

[0020] The embodiments of the present utility model can prolong the drug placement time, thereby promoting better drug absorption; at the same time, it can reduce the drug loss during the drug release process, reduce the harm caused by the drug to other organs through the blood flow scouring effect, and improve the drug transfer rate to the blood vessel; and because the placement time can be prolonged, it can also be used as a treatment device for blood vessel perforation.

[0021] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed description. Description of the Drawings

[0022] In the accompanying drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same reference numerals with alphabetical suffixes or different alphabetical suffixes may represent different instances of similar components. The drawings generally illustrate various embodiments by way of example and not limitation, and are used in conjunction with the description and the claims to explain the disclosed embodiments. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be an exhaustive or exclusive embodiment of the device or method. The drawings described herein are used to provide a further understanding of the present utility model and form a part of this application. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation of the present utility model. In the drawings:

[0023] Figure 1 is a schematic structural view of a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0024] Figure 2 is a schematic structural view of a drug-coated stent in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0025] Figure 3 is a schematic structural view of a matrix stent in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0026] Figure 4 is a schematic structural view of a connector in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0027] Figure 5 is a schematic view of the connection between a connector and a main unit in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0028] Figure 6 is a first schematic structural view of a connection section in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0029] Figure 7 is a second schematic structural view of a connection section in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model;

[0030] Figure 8 is a schematic structural view of a main unit in a drug-loaded device with sustainable perfusion in an embodiment of the present utility model.

[0031] Reference numerals:

[0032] 1 - First fixed section; 2 - Main body section; 3 - Second fixed section; 4 - First connection section; 5 - Second connection section; 6 - Main body unit; 7 - Connector; 8 - Barbed structure; 81 - Connecting rib; 82 - Sashimi part; 11 - Head; 12 - Middle part; 121 - Back; 122 - Abdomen; 13 - Tail; 61 - First main body unit; 62 - Second main body unit; 10 - Drug-coated stent; 20 - Guiding and retrieving catheter; 30 - Base; 31 - Connecting arm; 32 - Tantalum bead; 33 - Spring structure; 101 - Matrix stent; 102 - Balloon assembly. Detailed implementation manners

[0033] Next, with reference to the accompanying drawings, specific embodiments of the present utility model will be described in detail, but it is not intended to limit the present utility model.

[0034] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be regarded as a limitation, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present utility model.

[0035] The accompanying drawings included in and forming a part of the specification illustrate embodiments of the present utility model, and together with the general description of the present utility model given above and the detailed description of the embodiments given below are used to explain the principles of the present utility model.

[0036] These and other features of the present utility model will become apparent from the following description of the preferred forms of the embodiments given as non-limiting examples with reference to the accompanying drawings.

[0037] It should also be understood that although the present utility model has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present utility model, which have the features as described in the claims and thus are all within the protection scope defined thereby.

[0038] When combined with the accompanying drawings, in view of the following detailed description, the above and other aspects, features and advantages of the present utility model will become more apparent.

[0039] Hereinafter, specific embodiments of the present utility model will be described with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are only examples of the present utility model, and it can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to avoid obscuring the present utility model with unnecessary or redundant details. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but only as a basis and representative basis for the claims to teach those skilled in the art to use the present utility model in substantially any suitable detailed structure in various ways.

[0040] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present utility model are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] This specification may use the phrase "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", which may each refer to one or more of the same or different embodiments according to the present utility model.

[0042] The first embodiment of the present utility model provides a drug-loaded device capable of sustainable perfusion, such as Figures 1 to 8 shown, which includes a balloon dilation catheter, a drug-coated stent 10 and a guiding and retrieving catheter 20. Among them, the proximal end of the guiding and retrieving catheter 20 is connected to a base 30, the distal end of the guiding and retrieving catheter 20 is connected to the proximal end of the drug-coated stent 10, and the distal end of the drug-coated stent 10 is connected to the proximal end of the balloon dilation catheter. Here, the drug-coated stent 10 is controlled by the guiding and retrieving catheter 20 to expand and retract. Among them, when the drug-coated stent 10 expands, it can be close to the blood vessel wall and realize drug release, and when the drug release is completed, the drug-coated stent 10 can realize retraction.

[0043] The drug-coated stent 10 here is a self-expanding stent. The self-expanding stent is a super-elastic stent made by laser cutting a nickel-titanium alloy thin-walled tube. Generally, the matrix stent 101 is transported to the lesion site through, for example, a crimped delivery catheter, and self-expands after the fixation is released to make the blood unobstructed and play a supporting role in the lesion site.

[0044] Specifically, the drug-coated stent 10 includes a matrix stent 101. The matrix stent 101 is made of nickel-titanium alloy. A balloon assembly 102 is arranged inside the matrix stent 101. Here, the balloon assembly 102 can drive the matrix stent 101 to expand after inflation.

[0045] Furthermore, a film is provided on the surface of the matrix stent 101, and a drug coating is provided on the surface of the film. The drug coating can release drugs when the matrix stent 101 adheres tightly to the blood vessel wall after expansion. By providing the film on, for example, the inner and / or outer surface of the matrix stent 101, continuous forward blood flow is allowed to pass through the inside of the matrix stent 101, so that it can be used as a treatment device for vascular perforation. By providing the drug coating on the film, it can be used as a drug-loading device to release drugs for treatment, and combined with continuous forward blood flow passing through, the time of blood vessel wall adhesion can be prolonged, the absorption of drugs by the blood vessel can be improved, the drug effect time can be prolonged, and the purpose of effective treatment can be achieved.

[0046] In this embodiment, the matrix stent 101 is made of a shape-memory nickel-titanium alloy material. The matrix stent 101 is sleeved on the outside of the balloon assembly 102, and the complete or excessive expansion of the balloon assembly 102 is restricted by the structure of the matrix stent 101, so that the overall expansion of the balloon assembly 102 is restricted, effectively avoiding the "dog-bone" effect and reducing the trauma to the diseased blood vessel. The dog-bone effect here refers to the situation where when the stent delivery system is filled to the maximum recommended filling pressure, the diameters of the proximal and distal ends of the balloon are both larger than the diameters of the proximal and distal ends of the stent. At this time, it looks quite like a dog bone under X-ray, so it is called the dog-bone effect.

[0047] Furthermore, the matrix stent 101 includes a first fixing section 1, a radially expandable main body section 2, and a second fixing section 3 arranged axially in sequence. A first connecting section 4 is provided between the first fixing section 1 and the main body section 2, and a second connecting section 5 is provided between the main body section 2 and the second fixing section 3.

[0048] Among them, the first fixing section 1 and the second fixing section 3 are annular structures. The balloon assembly 102 is arranged inside the main body section 2, so that the main body section 2 can be expanded axially and radially and form a cylindrical structure after expansion; the drug coating is particularly provided on the main body section 2, so that the main body section 2 can adhere to the wall after expansion, thus facilitating the release of drugs.

[0049] Furthermore, both ends of the balloon assembly 102 are respectively connected to the first fixing section 1 and the second fixing section 3 in the matrix stent 101 to achieve fixation inside the matrix stent 101. The expansion of the balloon assembly 102 can assist the expansion of the main body section 2 to better achieve the wall adhesion effect. In addition, after the balloon assembly 102 retracts, there is a gap between the inside of the main body section 2 and the balloon assembly 102, which is convenient for continuous blood flow to pass through, thus prolonging the time of the main body section 2 adhering to the wall, promoting better absorption of drugs and increasing the drug effect time.

[0050] Specifically, the main body section 2 adopts a metal mesh structure to facilitate radial expansion, and it includes a plurality of main body units 6. Among them, adjacent main body units 6 are connected by connecting pieces 7. Wherein, the main body unit 6 includes a plurality of first main body units 61 located at the middle position and second main body units 62 located at both side end positions.

[0051] The first main body unit 61 here is a rod-shaped structure in the shape of a quasi-sine wave. The width of the first main body unit 61 is 0.09 - 0.15 mm. The quasi-sine wave shape makes the first main body unit 61 have pointed parts, and the pointed parts here are arc-shaped. The bending angle of the arc of each pointed part is 45 - 65°.

[0052] Preferably, the pointed parts are thickened. Specifically, when the base stent 101 made of nitinol alloy deforms, its stress is generally concentrated at the corners of the main body unit 6, that is, the pointed parts. Therefore, in the structure of the main body unit 6, the part located at the corner (such as the pointed part) should be appropriately widened and thickened or the bending angle should be reduced. In this embodiment, the first main body unit 61 in the shape of a quasi-sine wave has a relatively high compression ratio, so it can be placed in a smaller conveyor, and after expansion, the overall deformation of the base stent 101 is uniform and the force is also relatively uniform, which can make the stress distribution wide and not easily cause stress concentration, thereby enhancing the fatigue performance of the base stent 101.

[0053] Furthermore, the pointed parts between two adjacent first main body units 61 are connected by the connecting piece 7, and the second main body unit 62 is connected to the pointed part of the adjacent second main body unit 61 by the connecting piece 7.

[0054] It should be noted that all the main body units 6 here adopt rib structures, and their width and thickness are determined according to the requirements for stiffness or flexibility. This is mainly because the low-life units and high-stress units of the base stent 101 are concentrated at the turning positions in the main body section 2, while the high-life units and low-stress units of the base stent 101 are concentrated at the straight positions in the main body section 2, which is more in line with the stress distribution of a sine curve-shaped stent; during the anti-compression and bending processes, the occurrence of stress-induced martensite transformation is an important reason for the sudden collapse phenomenon of the base stent 101; increasing in the width or thickness direction of the main body unit 6 has basically the same influence on the anti-compression performance of the base stent 101, and the increase in width has a greater effect on flexibility than the increase in thickness.

[0055] Further, each of the first main body units 61 is arranged along the circumferential direction of the main body section 2, and a plurality of the first main body units 61 are arranged in sequence along the axial direction of the main body section 2; the second main body unit 62 is arranged along the circumferential direction of the main body section 2, and the second main body unit 62 here is connected to the first fixing section 1 and the second fixing section 3 respectively through the first connecting sections 4 and the second connecting sections 5 on both sides.

[0056] Further, two axially adjacent first main body units 61 located in the middle position and between the first main body unit 61 and the adjacent second main body unit 62 are connected through the connecting member 7. Here, the connecting member 7 is an asymmetric seahorse-shaped connecting rod. In this way, the asymmetric seahorse-shaped connecting rods are distributed at intervals along the circumferential direction or the axial direction. For example, two adjacent first main body units 61 are connected through a plurality of the connecting rods 7. Here, a plurality of the connecting rods 7 are arranged at intervals along the circumferential direction between the two first main body units 61; the connecting rods 7 between different two adjacent first main body units 61 are arranged at intervals along the axial direction.

[0057] Further, the asymmetric seahorse-shaped connecting rod includes a head 11, a middle part 12 and a tail 13. The head 11 is connected to one first main body unit 61, and the tail 13 is connected to another adjacent first main body unit 61. Among them, the head 11 and the tail 13 here are in a curled shape, and the curled shape is in an arc shape. Specifically, the head 11 has a first arc facing the first direction, and the tail 13 has a second arc facing the second direction. Here, the first arc and the second arc face in opposite directions.

[0058] In one embodiment, the head 11 is an n-shaped structure, the range of its width L1 is 0.10 - 0.18 mm, and its curling angle a is 120 - 140°; the tail 13 is also an n-shaped structure, the range of its width L2 is 0.10 - 0.18 mm, and its curling angle b is 120 - 145°; the head 11 and the tail 13 are connected to the middle part 12 with a certain radian.

[0059] The middle part 12 here has a tapered structure, which can ensure sufficient strength and certain flexibility. The middle part 12 includes a back part 121 and a belly part 122. The width gradually increases from the head part 11 to the belly part 122, and gradually decreases from the belly part 122 to the tail part 13. For example, it can gradually increase from the width of 0.04 - 0.07 mm at the head part 11 to 0.06 - 0.09 mm at the belly part 122; and gradually decrease from 0.06 - 0.09 mm at the belly part 122 to 0.04 - 0.07 mm at the tail part 13. For example, the width L4 of the middle part 12 is greater than the width L3 at the connection position between the middle part 12 and the head part 11, and also greater than the width L5 at the connection position between the middle part 12 and the tail part 13. In addition, the length of the middle part 12 here is preferably 0.8 - 1.5 mm.

[0060] In this embodiment, the first main body units 61 formed based on a structure in the shape of a quasi-sine wave are distributed at intervals in the radial direction to form the main body section 2. At the same time, the second main body units 62 are connected to the connection sections on both sides, enabling the main body section 2 to expand axially and radially, thereby ensuring excellent flexibility, achieving the lowest blood vessel closure rate, and ensuring that when the matrix stent 101 is bent at 90°, the closure rate is only 3 - 7%.

[0061] Considering that the two ends of the first connection section 4 are respectively connected to the main body section 2 and the first fixed section 1, and the two ends of the second connection section 5 are respectively connected to the main body section 2 and the second fixed section 3. Therefore, the second main body units 62 at the two end positions of the main body section 2 are respectively connected to the first fixed section 1 and the second fixed section 3 through the first connection section 4 and the second connection section 5 on both sides. In one embodiment, the first connection section 4 and the second connection section 5 here are straight connecting rods.

[0062] In another embodiment, the first connection section 4 and the second connection section 5 are in a wavy structure. Using this wavy structure facilitates corresponding deformation when the matrix stent 101 expands. As the matrix stent 101 expands, a corresponding expansion trend gradually occurs until the wavy structure is straightened, and then it contracts and resets as the matrix stent 101 is retracted, which can achieve the constraint on the balloon assembly 102. In this embodiment, by adopting the shape of the wavy connection section, the bending deformation of the matrix stent 101 caused by the remaining length during the compression process can be reduced, and at the same time, it will not affect the outer diameter within the effective length of the balloon dilation catheter, thereby ensuring that its passability in the blood vessel will not be affected by the fixing method of the stent and the balloon dilation catheter.

[0063] Specifically, since the matrix stent 101 is disposed outside the balloon assembly 102, certain length changes will occur during the contraction and expansion of the matrix stent 101, thereby generating an axial shortening rate. Here, the axial shortening rate = (L - L0) / L * 100%, where L represents the original length of the expansion of the matrix stent 101, and L0 represents the length after the matrix stent 101 is recovered and compressed.

[0064] In this way, the first connecting section 4 and the second connecting section 5 with a wavy structure can change along with the expansion and contraction of the matrix stent 101, and at the same time can also adapt to the changes in the expansion and contraction of the balloon assembly 102, and can offset the axial shortening rate generated after the expansion of the main body section 2, thereby improving the release accuracy of the drug-coated stent 10 at the target vascular lesion site.

[0065] In this embodiment, since the first connecting section 4 and the second connecting section 5 are connected to the main body section 2 and the corresponding fixing sections, they are straightened and bent during the expansion and compression of the balloon outside the catheter and the expansion and compression of the stent, thereby causing length changes. In this embodiment, the first connecting section 4 and the second connecting section 5 are arranged at intervals along the circumferential direction respectively, so that the number of connecting sections can be reduced, thereby reducing the winding problem of the connecting sections during the transfer process; in addition, the number of the second main body units 62 provided at both ends of the main body section 2 can also be reduced, thereby reducing the risk of the matrix stent 101 getting stuck in the guiding recovery catheter 20 during the preloading process, making the preloading process smoother.

[0066] Further, the length and radian of the first connecting section 4 can be respectively smaller than those of the second connecting section 5. Specifically, the length of the first connecting section 4 is 2 - 5 mm, and the radian is 50 - 70°, and the length of the second connecting section 5 is 3 - 6 mm, and the radian is 60 - 90°. The lengthening setting of the second connecting section 5 here is because it is necessary to avoid the welding position of the balloon assembly 102, so as not to affect the outer diameter within the effective length of the balloon dilatation catheter; the shortening setting of the first connecting section 4 is because the head end length of the balloon dilatation catheter is shorter and the distance from the balloon assembly 102 is closer, so by reducing the length of the connecting section, the head end length can be reduced, and reducing the head end length can increase the passing ability of the balloon dilatation catheter in the curved blood vessel.

[0067] Further, the first fixing section 1 and the second fixing section 3 are circular ring structures composed of V-shaped structure units arranged continuously along the circumferential direction. The first fixing section 1 is used to connect with the distal end of the balloon assembly 102; the second fixing section 3 is used to connect with the proximal end of the balloon assembly 102, so that the balloon assembly 102 is stably disposed inside the main body section 2.

[0068] Furthermore, the angle of the V-shaped structural unit of the first fixing section 1 is 60 - 80°, and the side length is 1.5 - 3.0 mm; the angle of the V-shaped structural unit of the second fixing section 3 is 40 - 60°, and the side length is 2.5 - 4.5 mm. Since the ring forming the fixing section is made of nitinol material and is a continuously arranged V-shaped structural unit, the size of the ring can be enlarged and reduced to meet different requirements; during the process of inserting the matrix stent 101 into the balloon dilatation catheter, the ring structures of the first fixing section 1 and the second fixing section 3 need to be expanded and compressed to the outer diameter size of the catheter when it is in contact with the balloon dilatation catheter.

[0069] In addition, since the outer diameter of the catheter of the second fixing section 3 is large, and the connection strength with the catheter is required to be relatively high, and at the same time the weldable area of the catheter is relatively long; the first fixing section 1 needs to be welded to the distal end of the balloon dilatation catheter, the outer diameter of the distal end is small and the length of the weldable area is short, so the V-shaped angle of the second fixing section 3 is smaller and the side length is longer than that of the first fixing section 1. In this way, while meeting the welding strength between the drug-coated stent 10 and the balloon dilatation catheter, the outer diameter of the effective length will not be increased.

[0070] Furthermore, the fixing method between the matrix stent 101 and the balloon assembly 102 is of two types: hot melting and welding. The specific operation method is as follows: the first fixing section 1 is sleeved on the distal position of the balloon assembly 102, and the second fixing section 3 is sleeved on the proximal position of the balloon assembly 102; hollow tubes with appropriate sizes made of materials such as Pebax, Pellethane, and Grilamid are respectively sleeved on both ends of the first fixing section 1 and the second fixing section 3, and a heat shrinkable tube is sleeved on the outside of the hollow tube. The first fixing section 1 and the second fixing section 3 are respectively fixed on the distal and proximal positions of the balloon assembly 102 by hot melting or laser welding.

[0071] Among them, when the laser welding method is adopted, the welding steps generally include 3-6 steps. Specifically, the first step is circumferential welding, with a power of 280 mW, a rotation speed of 100 rpm, a duration of 2.0 Sec, and a spot size of 1.00 mm; the second step is circumferential welding, with a power of 350 mW, a rotation speed of 100 rpm, a duration of 2.0 Sec, and a spot size of 1.00 mm; the third step is dynamic welding, with a power of 280 mW, a rotation speed of 300 rpm, a moving speed of 0.2 mm / s, a moving distance of 1.5 mm, and a spot size of 1.00 mm; the fourth step is dynamic welding, with a power of 290 mW, a rotation speed of 400 rpm, a moving speed of 0.15 mm / s, a moving distance of -2.00 mm, and a spot size of 1.00 mm; the fifth step is dynamic welding, with a power of 295 mW, a rotation speed of 500 rpm, a moving speed of 0.15 mm / s, a moving distance of -2.50 mm, and a spot size of 1.00 mm; the sixth step is dynamic welding, with a power of 320 mW, a rotation speed of 500 rpm, a moving speed of 0.20 mm / s, a moving distance of 4.50 mm, and a spot size of 1.00 mm; finally, the heat shrinkable tube is torn off after welding is completed.

[0072] In addition, in order to facilitate the connection of the first connecting section 4 and the second connecting section 5 to the first fixing section 1 and the second fixing end 3 respectively, in another embodiment, the first connecting section 4 or the second connecting section includes a connecting arm 31. One end of the connecting arm is connected to the second main body unit 62, and a tantalum bead 32 is provided at the other end of the connecting arm 31. Here, the detachable fixation with the first fixing section 1 or the second fixing section 3 can be achieved through the tantalum bead 32; in addition, the tantalum bead 32 also has strong developability, which can help the operator determine the position of the drug-coated stent 10 during the operation.

[0073] In another embodiment, the first connecting section 4 or the second connecting section 5 adopts a spring structure 33. Here, the spring structure 33 can be arranged in a spring shape by winding one end of a developing filament around the head end of the first fixing section 1. The soft spring structure 33 can avoid the damage to the blood vessel caused by the stent directly pressing against the blood vessel wall due to misoperation when the instrument exits the catheter. At the same time, the spring structure 33 here adopts a platinum-tungsten alloy, and the platinum-tungsten alloy has strong developability, which can help the operator determine the position of the drug-coated stent 10 during the operation.

[0074] Further, a barbed structure 8 for development is provided on the main body unit 6. The shape of the barbed structure 8 here is similar to the shape of the number 7. The barbed structure 8 is particularly provided on the second main body unit 62, and it includes a connecting rib 81 connected to the main body unit 6 and a sashimi part 82. Here, the connecting rib 81 is a straight rod structure. Among them, the transition part where the connecting rib 81 is connected to the main body unit 6 is thickened. For example, the rod width is set to 0.7 - 0.15 mm, which can enhance the connection strength between the barbed structure 8 and the main body unit 6.

[0075] Further, the sashimi part 82 is made of a development material such as platinum-iridium alloy and welded to the connecting rib 81. The platinum-iridium alloy here has strong developability, which can help the surgeon determine the position and expansion state of the drug-coated stent 10 during the operation.

[0076] Further, the sashimi part 82 adopts a rod-shaped structure with a gradually changing width. The width of the sashimi part 82 gradually increases from the position where it is connected to the connecting rib 81 to the open end of the sashimi part 82. If the welding material is a ring structure, the gradually changing structure can assist in fixing the ring structure and reduce the risk of the ring structure falling off during the production and preparation process.

[0077] Here, a predetermined angle is formed between the sashimi part 82 and the connecting rib 81. The predetermined angle d here is 80° - 88°. Among them, the straight rod part of the sashimi part 82 is slightly inclined towards the straight rod of the main body unit 6 and is as parallel as possible to the straight rod part of the main body unit 6. This can reduce the overall width of the barbed structure 8. By bringing the sashimi part 82 closer to the straight rod part of the main body unit 6, it can also reduce the resistance between the head end of the sashimi part 82 and the inner cavity of the catheter during the release and recovery of the drug-coated stent 10, and reduce the risk of scraping the blood vessel after the drug-coated stent 10 is released.

[0078] As described above, in order to achieve the release of the drug, a film is provided on the surface of the base stent 101, and a drug coating is provided on the surface of the film. Since the film covering methods are divided into hot melt film covering and braided film covering, the materials used can be, for example, ePTFE, PU, PET, etc.; in the embodiment of the present invention, hot melt film covering is adopted. The specific film covering steps include: First step, prepare a hollow or solid mandrel suitable for the inner cavity of the base stent 101, take a suitable length of film and cover it on the mandrel, and the number of film covering layers is 2 - 10 layers; Second step, place the main body section 2 on the film covering section mandrel; Third step, cover the film on the main body section 2; Fourth step, wrap the outer film with raw tape or heat shrink tube; Fifth step, place the completed base stent 101 in a heating furnace for heating, and the heating temperature is (300 - 380) °C.

[0079] According to the above structure of the present embodiment, the specific usage of the present utility model embodiment is as follows: the base stent 101 and the balloon assembly 102 of the drug-coated stent 10 are pre-installed in the guide retrieval catheter 20, and the vascular access device is prepared according to the standard PTCA operating procedure. Here, the operator's proximal operation is only the hypotube, guidewire and sheath of the balloon. Compared with the retrieval stent with a similar thrombectomy stent structure, the operator's operation is facilitated by reducing one core wire.

[0080] Specifically, a guide catheter with a hemostatic valve is inserted and a guide wire of 0.014" is inserted into the guide catheter, and the length of the guide wire should be able to reach the distal end of the stenotic lesion; the proximal end of the guide wire is inserted from the head end of the balloon dilatation catheter in this embodiment, and the guide wire cavity is led out until the drug-carrying device is delivered to the lesion along the guide wire; the guide recovery catheter 20 is then withdrawn to release the drug-coated stent 10 for wall adhesion operation, and the pressure is released after the balloon assembly 102 is filled for 30s-60s; after the drug-coated stent 10 is left stationary in the blood vessel for 1min-10min, the guide recovery catheter 20 is conveyed forward to recover the drug-coated stent 10, and finally all the devices are withdrawn from the body.

[0081] Among them, since the drug-coated stent 10 in this embodiment adopts a self-expanding nickel-titanium alloy structure, the drug-coated stent 10 can adhere to the wall by itself after being released. The balloon assembly 102 here provides an auxiliary wall adhesion function and can provide a guide wire cavity. After the balloon assembly 102 retracts, the base stent 101 will not be reset as the balloon assembly 102 retracts. Therefore, the inner cavity of the base stent 101 has continuous forward blood flow without obstructing the vascular lumen, thereby achieving an effect similar to that of a perfusion balloon catheter; at the same time, since the inside and outside of the base stent 101 are coated with, for example, an ePTFE membrane to block blood seepage, it can also be used as a treatment device for vascular perforation. Here, the ePTFE membrane can also be coated with rapamycin and can be used as a drug-carrying device, for example, for the treatment of primary coronary artery vascular lesions.

[0082] The embodiments of the present utility model mainly achieve the following technical effects: 1. After the drug-coated stent 10 is adhered to the blood vessel, the expansion of the balloon assembly 102 will not affect its uniformity; 2. The drug-coated stent 10 is used in cooperation with the guiding and retrieving catheter 20 to improve the pushing performance and achieve better retraction; 3. The connecting member 7 is designed with an asymmetric seahorse structure, which can improve flexibility and better adapt to blood vessels; 4. The matrix stent 101 is provided with inner and outer coatings, and can also be used for coronary perforation treatment, while increasing the surface area for drug loading; 5. The drug-coated stent 10 is provided with drug-loaded outer coating, and when used in cooperation with the balloon assembly 102, it can enhance its wall adhesion and promote the absorption of drugs by blood vessels; 6. The drug-coated stent 10 is used in cooperation with the outer tube and delivered to the target blood vessel position, which can reduce the loss of drugs caused by blood flow scouring; 7. After the balloon assembly 102 is retracted, the inner cavity of the matrix stent 101 can allow blood flow, which can prolong the placement time of the drug in the blood vessel, better promote drug absorption, and reduce the risk of blood vessel rebound and in-stent restenosis.

[0083] The embodiments of the present utility model can prolong the drug placement time, thereby promoting better drug absorption; at the same time, it can reduce the drug loss during drug release, reduce the harm caused to other organs by the drug through blood flow scouring, and improve the drug transfer rate to blood vessels; and because the placement time can be prolonged, it can also be used as a treatment device for blood vessel perforation.

[0084] In addition, the features of the embodiments shown in the accompanying drawings of the present application or various embodiments mentioned in this specification do not have to be understood as independent embodiments of each other. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to generate other embodiments not described in words or with reference to the accompanying drawings.

[0085] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A drug-loaded device with sustainable perfusion, characterized in that, It includes a balloon dilation catheter, a drug-coated stent, and a guiding and retrieving catheter connected in sequence. The drug-coated stent includes a self-expanding matrix stent. A balloon assembly is arranged inside the matrix stent. A film is arranged on the surface of the matrix stent, and a drug coating is arranged on the surface of the film. The matrix stent includes a radially expandable main body section. The two ends of the main body section are connected to the fixed section through connection sections. The balloon assembly is arranged inside the main body section and fixed through the fixed section.

2. The drug-loading device according to claim 1, wherein The main body section adopts a network structure, which includes a plurality of main body units. Adjacent main body units are connected through connecting pieces, and the connecting pieces are asymmetric seahorse-shaped connecting rods.

3. The drug-loading device according to claim 2, wherein, The main body units include a plurality of first main body units located at the middle position and second main body units located at both side end positions. The first main body units adopt a structure in the shape of a quasi-sine wave. Each first main body unit is arranged along the circumferential direction of the main body section. A plurality of first main body units are arranged in sequence along the axial direction of the main body section. The second main body units are arranged along the circumferential direction of the main body section, and the second main body units are connected to the fixed section through the connection sections.

4. The drug-loading device according to claim 3, wherein, The first main body unit has a tip. The tips of two adjacent first main body units are connected through the connecting piece. The tip of the second main body unit and the tip of the adjacent second main body unit are connected through the connecting piece. The connecting pieces are distributed at intervals along the circumferential direction or the axial direction.

5. The drug-loading device according to claim 4, characterized in that, The asymmetric seahorse-shaped connecting rod includes a head, a middle part, and a tail. The head and the tail are connected to two different first main body units. The head and the tail are in a curled shape. The head has a first arc facing the first direction, and the tail has a second arc facing the second direction. The orientations of the first arc and the second arc are opposite.

6. The drug-loading device according to claim 5, wherein, The head and the tail are in an n-shaped structure, and the head and the tail are connected to the middle part at a certain radian.

7. The drug-loading device according to claim 5, characterized in that, The middle part is a gradient structure. The middle part includes a back and a belly. The width gradually increases from the head to the belly and gradually decreases from the belly to the tail.

8. The drug-loading device according to claim 4, characterized in that, The fixed section is an annular structure composed of V-shaped structural units arranged continuously in the radial direction.

9. The drug-loading device according to claim 8, wherein, The connection section is a straight connecting rod or a wavy connecting rod.

10. The drug-loading device according to claim 8, characterized in that, The connection section includes a connecting arm, and a tantalum bead connected to the fixed section is arranged at the end of the connecting arm.

11. The drug-loading device according to claim 8, characterized in that, The connection section adopts a spring structure, and the spring structure is arranged in a spring shape by winding one end of a developing filament around the head end of the fixed section.

12. The drug-loading device according to claim 8, wherein, A barbed structure in the shape of a 7 is arranged on the main body unit, which includes a connecting rib connected to the main body unit and a barbed part. The connecting rib is in a straight rod structure. The barbed part is made of a developing material and connected to the connecting rib. The barbed part forms a predetermined angle with the connecting rib and is parallel to the main body unit.

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