CN120360754B

CN120360754B - Drug eluting stent

Info

Publication number: CN120360754B
Application number: CN202510873643.5A
Authority: CN
Inventors: 荆洪娟; 黄嘉平; 曹辉
Original assignee: Hangzhou Yike Medical Technology Co ltd
Current assignee: Hangzhou Yike Medical Technology Co ltd
Priority date: 2025-06-27
Filing date: 2025-06-27
Publication date: 2025-09-05
Anticipated expiration: 2045-06-27
Also published as: CN120360754A

Abstract

The invention discloses a drug eluting stent, which comprises a stent body and a plurality of thorn-shaped members, wherein the stent body is provided with a radially compressible contracted state and an expanded state which radially self-expands to support blood vessels, the plurality of thorn-shaped members are arranged on the outer surface of the stent body and are coated with a drug coating for inhibiting restenosis of the blood vessels, and are configured to protrude from the outer surface of the stent body towards the outer side of the stent body to pierce calcification lesions of the inner wall of the blood vessels when the stent body is switched from the contracted state to the expanded state, each thorn-shaped member is provided with an elastically deformable part and is configured to be capable of adaptively deforming according to the thickness of the contacted calcification lesions so as to realize effective penetration of irregular calcification lesions and promote drug release, thus ensuring that drugs can be uniformly distributed in target lesion areas and remarkably improving the utilization rate and treatment effect of the drugs.

Description

Drug eluting stent

Technical Field

The invention relates to the technical field of medical instruments, in particular to a drug eluting stent.

Background

In interventional therapy of vascular stenosis, the drug eluting stent gradually replaces a metal bare stent with a relatively simple structure because the drug eluting stent can effectively inhibit restenosis after operation, and becomes a main therapeutic means in clinical application. The stent is coated with a layer of drug coating for inhibiting restenosis of blood vessel, and the drug coating can be slowly released into the wall of blood vessel to prevent smooth muscle cell from excessive proliferation, thereby obviously reducing the occurrence rate of restenosis. However, conventional drug eluting stents still present challenges in treating stenotic lesions that are accompanied by calcified lesions. Because calcification lesions are hard and poorly permeable, effective diffusion of the drug from the stent coating to the deep vessel wall may be hindered, affecting the therapeutic effect.

In order to solve the above problems, chinese patent CN113599032a adds a plurality of tiny spikes of uniform length on the basis of the conventional drug eluting stent. When the stent expands, the spines are synchronously unfolded and penetrate into calcified plaques, and penetrate into the middle membrane and even adventitia layers of the blood vessel, so that local deep administration of calcified lesion areas is realized, and the distribution efficiency and the treatment effect of the medicine on the lesion areas are enhanced.

Although the above design improves the targeted delivery capability of the drug to calcified lesions to some extent, there are still certain limitations in practical clinical application. Calcified lesions are often characterized by morphological irregularities, thickness distribution irregularities, etc. For a fixed length thorn-like structure, the thorn-like structure lacks adaptive adjustment capability, and is difficult to cope with the difference of calcified thickness of different areas. Specifically, in areas with thicker calcifications, some thorns cannot be fully penetrated due to the greater penetration resistance, while in areas with thinner calcifications, thorns of the same length may only slightly contact or even not fully contact the lesion, resulting in insufficient drug release or maldistribution, thereby affecting the overall therapeutic effect, especially when dealing with complex, multifocal calcified lesions.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art, and provides a drug eluting stent which aims to better realize drug release when treating calcification lesions with irregular shapes.

According to the present invention, there is provided a drug eluting stent comprising a stent body having a radially compressible contracted state and an expanded state radially self-expanding to support a blood vessel, and a plurality of spike members provided on an outer surface of the stent body and coated with a drug coating to inhibit restenosis of the blood vessel and configured to protrude from the outer surface of the stent body toward an outer side of the stent body to pierce a calcified lesion of an inner wall of the blood vessel when the stent body is switched from the contracted state to the expanded state, each of the spike members having an elastically deformable portion and being configured to be capable of being adaptively deformed according to a thickness of the calcified lesion contacted to achieve effective penetration of the irregular calcified lesion and to promote drug release.

Further, each of the spike members is generally sheet-like in configuration and gradually diverges from the proximal end toward the distal end when the stent body is in the expanded state.

Further, each of the spike-like members includes a fixing section, a deforming section and a spike section, the fixing section is connected to the outer surface of the stent body, and the deforming section is connected between the fixing section and the spike section and forms a portion of the spike-like member that is elastically deformable.

Further, the fixing section is located on the outer circumference of the support main body, and the deformation section and the spike section tilt outwards relative to the fixing section.

Further, the deformation section is provided with a slotted structure to be configured as a spring structure to form an elastically deformable portion of the thorn-shaped member.

Further, the inner wall surface of the grooved structure is coated with a drug coating.

Further, the slotted structure forms at least one arcuate region.

Further, the slotting structure is positioned at two sides of the length direction of the deformation section, and the fixing section and the spike section are respectively connected at two ends of the length direction of the deformation section.

Further, the slotted structure comprises at least a first set of slots extending through one side of the deformed segment and a second set of slots extending through the other side of the deformed segment.

Further, the first set of slots and the second set of slots are staggered.

Compared with the prior art, the invention can adaptively deform according to the thickness of the calcified lesions when the stent is switched from the contracted state to the expanded state by arranging the plurality of thorn-shaped members with the elastic deformation parts, thereby realizing the effective penetration of the irregular calcified lesions and promoting the release of the medicine. Even in calcified lesion areas with larger thickness difference, all thorn-shaped members can still keep good penetrating power and structural stability, ensure that the medicine can be uniformly distributed in the target lesion areas, and remarkably improve the medicine utilization rate and the treatment effect.

Drawings

The invention will be more fully understood and its attendant advantages and features will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic overall structure of a first embodiment of the present invention.

Fig. 2 is an enlarged view of a portion a in fig. 1.

Fig. 3 is a schematic view of the deformed and spike sections of fig. 2.

Fig. 4 and 5 are schematic structural views of a deformation section and a spike section in the second embodiment of the present invention.

In the drawing, 10 is a bracket main body, 20 is a thorn-shaped member, 21 is a fixed section, 22 is a deformation section, 23 is a spike section, 231 is a first section, 232 is a second section, 233 is a third section, 30 is a slotting structure, 31 is a first group of slotting, 32 is a second group of slotting, and 40 is a medicine carrying slot.

It should be noted that the drawings are for illustrating the invention and are not to be construed as limiting the invention. Note that the drawings representing structures may not be drawn to scale. Also, in the drawings, the same or similar elements are denoted by the same or similar reference numerals.

Detailed Description

In order that the invention may be more readily understood, a detailed description of the invention is provided below along with specific embodiments and accompanying figures.

The terms "proximal" and "distal" in the sense of the present invention should be understood as meaning, viewed from the direction of the attending physician, the term "proximal" referring to the end proximal to the attending physician, i.e. corresponding to the "left end" referred to with reference to the accompanying drawings, and the term "distal" referring to the end distal to the attending physician, i.e. corresponding to the "right end" referred to with reference to the accompanying drawings.

Embodiment one as shown in fig. 1 to 3, the drug eluting stent of the present embodiment includes a stent body 10 and a plurality of spike members 20. The stent body 10 is a hollow tubular structure, is formed by carving a metal tube such as a nickel titanium tube by laser and shaping the metal tube by heat treatment, has a plurality of meshes formed on the surface thereof, and has a contracted state in which the metal tube is contracted radially and an expanded state in which the metal tube is self-expanded radially to support a blood vessel. The flexibility and the strength of the stent are ensured, the stent can be smoothly unfolded in vivo and stably supported on the vessel wall, and the stent has good biocompatibility and shape memory function due to the selection of the nickel-titanium alloy material, so that the structural stability of the stent can be maintained in different environments. It should be noted that, during actual use, the present embodiment often needs to push the stent body 10 to expand by filling with a balloon, so that the plurality of thorn-shaped members 20 can penetrate into the lesion.

The plurality of thorn-shaped members 20 are circumferentially arranged on the outer surface of the bracket main body 10, and the thorn-shaped members 20 and the bracket main body 10 are integrally formed by heat setting after laser engraving, so that the consistency and the stability of the structure are ensured. After the integral formation, the entire stent is coated with a drug coating to inhibit restenosis, which may be a drug commonly used in the art, such as rapamycin, and will not be described in detail herein. The design of the drug coating is beneficial to improving the utilization rate of the drug and realizing deep drug delivery to the lesion area. The drug coating can be used as an antiproliferative drug and can effectively inhibit the excessive proliferation of smooth muscle cells, thereby reducing the risk of vascular restenosis.

When the stent body 10 is switched from the contracted state to the expanded state, the plurality of thorn-like members 20 protrude from the outer surface of the stent body 10 toward the outside of the stent body 10 to penetrate into calcification lesions of the inner wall of the blood vessel, thereby achieving deep administration of the calcification lesion region. The spike member 20 is generally sheet-like in configuration and gradually diverges from the proximal to distal direction from the stent body 10 when the stent body 10 is in the expanded state, which facilitates safe withdrawal of the entire drug eluting stent from the distal to proximal direction. Each spike member 20 has an elastically deformable portion and is configured to be adaptively deformed according to the thickness of the calcified lesion in contact to achieve effective penetration of the irregular calcified lesion and to facilitate drug release. Even in calcified lesion areas with larger thickness difference, all thorn-shaped members 20 can still keep good penetrating power and structural stability, ensure that the medicine can be uniformly distributed in the target lesion areas, and remarkably improve the medicine utilization rate and the treatment effect.

Each of the spike members 20 includes a fixing section 21, a deforming section 22 and a spike section 23 connected in sequence, the spike section 23 being a portion of the spike member 20 remote from the outer surface of the stent body 10. The fixing section 21 is connected to the outer surface of the stent body 10 and is located on the outer circumference of the stent body 10, and the deformation section 22 and the spike section 23 are tilted outwards relative to the fixing section 21, so that the deformation section 22 and the spike section 23 can be gradually deviated from the stent body 10 from the proximal end to the distal end direction when the stent body 10 is in the expanded state. The deformation section 22 is connected between the fixing section 21 and the spike section 23, forms an elastically deformable part on the spike-shaped member 20, and allows the spike section 23 to be adaptively deformed after contacting calcified lesions of different thicknesses, thereby realizing effective penetration of the spike section 23 into irregular calcified lesions and promoting drug release.

To enhance the elastic deformability of the spike member 20, the deformation section 22 is provided with a slotted structure 30 to configure a spring-like structure. The grooving structures 30 are located at two sides of the length direction of the deformation section 22, and the fixing section 21 and the spike section 23 are respectively connected to two ends of the deformation section 22 in the length direction. The slotting structure 30 at least comprises a first group of slotting 31 and a second group of slotting 32, the first group of slotting 31 and the second group of slotting 32 are all formed into U-shaped slots, the first group of slotting 31 penetrates one side of the deformation section 22, the second group of slotting 32 penetrates the other side of the deformation section 22, and the first group of slotting 31 and the second group of slotting 32 are arranged in a staggered mode, so that the slotting structure 30 forms at least one arched area, and the effect of a spring is simulated. This design not only enhances the elastic response capability of the spike member 20, but also enhances its adaptability to lesions of different thickness. The slotted structure 30 is designed similar to a spring mechanism in that the slotted structure 30 is compressively deformed when a thicker calcified lesion is encountered and slightly or non-curved when a thinner lesion is encountered, thereby ensuring that each of the spike members 20 effectively penetrate the lesion tissue and that the spike members 20 are relatively independent and independent of each other.

The inner wall surface of the slot structure 30 is also coated with a drug coating, i.e. the first set of slots 31 and the second set of slots 32 not only act as springs, but also contain the drug coating inside, which not only improves the drug loading of the whole thorn-shaped member 20, but also ensures that the drug can be released rapidly when contacting the diseased tissue, thus achieving the optimal therapeutic effect. The design of the multi-layer drug coating enables the drugs to be distributed more uniformly in the whole lesion area, and the drug utilization rate and the treatment effect are remarkably improved. In addition, due to the presence of the slotted structure 30, the drug may be released at different locations of the spike member 20, further increasing the penetration depth and coverage of the drug.

Therefore, the drug eluting stent of the embodiment can effectively cope with calcification lesions with different thicknesses, ensure that the drug can be uniformly distributed in a target lesion area, and remarkably improve the drug utilization rate and the treatment effect.

Embodiment two unlike embodiment one, the structure of the spike section 23 of this embodiment is different as shown in connection with fig. 4 and 5. In this embodiment, the spike section 23 is a split structure and includes a first section 231, a second section 232, and a third section 233 that are root-connected together. The root portions of the first, second and third sections 231, 232, 233 are connected to different positions of the deformation section 22 at an end far from the stent body 10, and are configured to be fitted to each other in a compact structure such as a triangle shape in a natural state, as shown in fig. 4. The design not only enables the spike section 23 to keep a compact shape when not stressed and is beneficial to smooth transportation of the stent, but also enables the spike section 23 to elastically deform and separate relative to the root when receiving reverse acting force from calcified lesions, thereby increasing the penetration angle and the contact area, remarkably improving the coverage range and penetration depth of calcified lesion areas, reducing the sliding risk and improving the penetration efficiency, thereby enhancing the effect of inhibiting vascular restenosis and improving the overall treatment performance of the stent.

Specifically, the first, second and third sections 231, 232 and 233 are integrally formed on the outer surface of the stent body 10 through a laser cutting process. The first and third segments 231, 233 are symmetrically disposed on either side of the second segment 232 and are capable of deflecting the second segment 232 in opposite directions, respectively, when subjected to opposing forces from calcified lesions, as shown in particular in fig. 5. The tips of the second segment 232 are more protruding than the tips of the first and third segments 231, 233 so that when penetrating a calcified lesion, the second segment 232 first contacts and penetrates the calcified lesion to serve as an anchor. In addition, the second section 232 is sized larger than the first and third sections 231, 233 to strengthen the anchoring effect. Because the second section 232 has a relatively large size, the second section 232 is provided with the medicine carrying groove 40, the medicine carrying groove 40 is not penetrated, and the medicine carrying space is formed inside the medicine carrying groove 40 and is filled with the medicine coating, so that the treatment effect is further improved.

For a better understanding of the design flexibility of the spike section 23, it will be appreciated that the spike section 23 may also comprise only a first section and a second section connected together at the root or more sections depending on the actual requirements. The tip-puncturing segment is a split structure as long as it includes at least a first segment and a second segment connected together at a root, and a predetermined gap is left between the first segment and the second segment to allow the two to separate along the root after being subjected to a reverse force from the calcified lesion to achieve a greater angle of penetration into the calcified lesion. The flexible design can be adjusted according to different clinical requirements to achieve the optimal therapeutic effect.

It can be seen that the spike section of the embodiment adopts a split structure consisting of at least a first section and a second section connected by a root. The split structure keeps fit under the natural state, forms a compact shape, and is favorable for smooth conveying of the bracket. In the puncturing process, the first section and the second section can be relatively unfolded under the action of external force, so that the puncturing angle and the contact area are increased, the coverage range and the puncturing depth of calcified lesion areas are remarkably improved, the sliding risk is reduced, the puncturing efficiency is improved, the effect of inhibiting vascular restenosis is enhanced, and the overall treatment performance of the stent is improved. In addition, the split design not only improves the penetrating efficiency, but also can be better suitable for calcification lesions with different thicknesses and shapes. The multi-section structure of the spike section can effectively disperse pressure when facing thicker calcified lesions, avoid penetration failure or damage to surrounding tissues caused by excessive concentrated stress, and can provide larger contact area when facing thinner calcified lesions, ensure that medicines can be uniformly distributed in the whole lesion area, and remarkably improve the utilization rate and treatment effect of the medicines.

Other structures of this embodiment are identical to those of the embodiment, and are not described herein.

It will be appreciated that although the invention has been described above in terms of preferred embodiments, the above embodiments are not intended to limit the invention. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A drug-eluting stent, comprising a stent body and a plurality of thorn-like members, the stent body having a radially compressible contracted state and a radially self-expanding expanded state for supporting a blood vessel, the plurality of thorn-like members being disposed on the outer surface of the stent body and coated with a drug coating for inhibiting restenosis of the blood vessel, and being configured to protrude from the outer surface of the stent body toward the outside of the stent body to penetrate calcified lesions on the inner wall of the blood vessel when the stent body switches from the contracted state to the expanded state, characterized in that each thorn-like member has an elastically deformable portion and is configured to adaptively deform according to the thickness of the calcified lesion it contacts, so as to achieve effective penetration of irregular calcified lesions and promote drug release, and each thorn-like member comprises a fixed segment, a deformable segment, and a spike segment, the fixed segment being connected to the outer surface of the stent body, the deformable segment being connected between the fixed segment and the spike segment and forming the elastically deformable portion of the thorn-like member.

2. The drug-eluting stent according to claim 1, wherein each thorn-shaped member is in a sheet-like structure as a whole and gradually deviates from the stent body from the proximal end to the distal end when the stent body is in an expanded state.

3 . The drug-eluting stent according to claim 1 , wherein the fixed section is located on the outer circumference of the stent body, and the deformable section and the spike section are tilted outward relative to the fixed section.

4 . The drug-eluting stent according to claim 1 , wherein the deformation section is provided with a slotted structure to form a spring structure to form a portion of the thorn-shaped member that can undergo elastic deformation.

5 . The drug-eluting stent according to claim 4 , wherein the inner wall surface of the slotted structure is coated with a drug coating.

The drug-eluting stent according to claim 4 , wherein the slotted structure forms at least one arcuate region.

7. The drug-eluting stent according to claim 4, wherein the slotted structure is located on both sides of the deformation segment in the length direction, and the fixed segment and the spike segment are respectively connected to the two ends of the deformation segment in the length direction.

8. The drug-eluting stent according to claim 7, wherein the slotted structure comprises at least a first group of slots and a second group of slots, the first group of slots runs through one side of the deformation section, and the second group of slots runs through the other side of the deformation section.

9 . The drug-eluting stent according to claim 8 , wherein the first group of slots and the second group of slots are arranged alternately.