Degradable blood flow guiding device

Abstract

A main body of the degradable blood flow guiding device is a hollow tubular support formed by winding and weaving a plurality of strands of wires in a staggered mode, after the degradable blood flow guiding device is placed in a blood vessel tumor carrying section, blood flow can flow through a hollow inner cavity, part of blood flows into an aneurysm from a support grid, the inflow amount of the blood is limited due to the fact that the support covers the position of a tumor opening, and therefore the blood flow guiding device can be used for guiding blood flow. In particular, the impact of blood on aneurysm can be relieved, and the wire is made of zinc alloy and a small amount of nickel-titanium alloy; through the mode that zinc alloy and a small amount of nickel-titanium alloy are mixed, overall degradability is achieved, long-term medicine taking is not needed, and stimulation to the blood vessel wall due to long-term implantation is greatly reduced. In addition, a film layer is further arranged on the guide device and used for further optimizing flow direction control, and the treatment effect is improved.

Description

Technical Field

[0001] The utility model belongs to the field of implantable medical devices, and in particular relates to a degradable blood flow guiding device. Background Art

[0002] Aneurysms are a potentially life-threatening disease. They are formed when the blood vessel wall becomes thinner and continues to expand under the impact of blood flow, including the aneurysm opening part connected to the blood vessel and the aneurysm body. When the aneurysm ruptures due to increased blood pressure or other factors, rapid bleeding will occur. Ruptured aneurysms have a very high mortality rate. Aneurysms can form in the brain, abdomen, and multiple locations throughout the body throughout the circulatory system. The walls of cerebral arteries are thin, complex and tortuous, with large curvature, multiple bifurcations, sensitive to stimulation, and lack of tissue support around them. The most common cerebral aneurysms generally occur at the branches, bifurcations, or bends of blood vessels. This is mainly due to the hemodynamic factors at this site, that is, the impact of axial blood flow on the distal end of the blood vessel forms shear stress, resulting in the destruction of the elastic layer of the blood vessel and the formation of saccular protrusions. At the same time, shear stress stimulates the damaged vascular endothelial cells to divide and grow, and then grow into aneurysms. This shear stress is the basic cause of aneurysm formation. The blood in the formed aneurysm is turbulent, forming vortices, inducing fluid resonance, triggering oscillation of the blood vessel wall and promoting its degeneration, growth, and even rupture.

[0003] Common treatment methods in existing technologies include: 1. Surgical clipping of aneurysms, using metal clips to clip the neck of the aneurysm through craniotomy, but this method requires craniotomy and is often accompanied by serious sequelae. 2. Intravascular interventional therapy, using detachable coils (or micro-wire coils or other embolic materials such as detachable balloons, curable liquids, etc.) to embolize aneurysms, but the devices used for embolization may touch nerves or other biological tissues and cause adverse neurological symptoms. 3. Intravascular interventional stent implantation. In contrast, intravascular interventional therapy has the advantages of less trauma, fewer complications, higher safety, less pain for patients, easier acceptance, shorter hospital stays, and tolerance even for the elderly and seriously ill.

[0004] However, because this type of device is a material that is directly implanted into the cerebral artery, the thrombogenicity-induced thrombosis is the most important factor affecting the effect. Long-term antiplatelet aggregation drug treatment after surgery is a powerful measure to reduce the occurrence of ischemic complications. However, continuous medication also greatly increases the economic and physical burden after surgery, and continuous antiplatelet aggregation treatment can also cause additional health problems. At the same time, long-term implanted stents may also cause problems such as hyperplasia or vascular occlusion. Utility Model Content

[0005] The utility model discloses a degradable blood flow guiding device, which is made degradable as a whole by mixing zinc alloy wire with a small amount of elastically deformable wire, does not require long-term medication, and greatly reduces the stimulation of the blood vessel wall caused by long-term implantation. In addition, a membrane layer is also provided on the guiding device to further optimize the flow direction control, increase the endothelialization speed, and improve the treatment effect.

[0006] A degradable blood flow guiding device comprises a stent, which is a hollow tubular structure. The stent covers the aneurysm opening where the aneurysm is connected to a blood vessel, so as to restrict blood from flowing into the aneurysm. The stent is formed by at least three wires interlaced and woven with each other, so as to promote and / or maintain radial and / or axial expansion of the stent in a body cavity. The wires are zinc alloy wires and elastically deformable wires, respectively, and the number of the zinc alloy wires is greater than the number of the elastically deformable wires. A membrane layer is also arranged outside the stent, and the membrane layer partially or completely covers the outside of the stent.

[0007] Furthermore, the stent is a non-tightly woven structure formed by mixing multiple strands of wire, and the ratio of the number of zinc alloy wires to the number of elastically deformable wires in the wires is between 5:1 and 20:1.

[0008] Furthermore, the non-tightly woven structure is a hollow tubular body formed by interlacing and weaving multiple strands of wire in a spiral and reverse spiral form.

[0009] Furthermore, when the same wire is spirally wound into a hollow tubular body, a certain gap is left between adjacent turns.

[0010] Furthermore, the stent has segments with different densities, wherein the outer sides of the denser segments are covered with a membrane layer.

[0011] Furthermore, the film layer is made of one or more degradable polymer materials.

[0012] Furthermore, the degradable polymer material includes, but is not limited to, polyglycolide, polylactic acid, polyglycolide-lactide, polycaprolactone, polyglycolic acid, poly-L-glutamic acid, polyaspartic acid, and polydioxanone.

[0013] Furthermore, the degradable polymer material includes, but is not limited to, collagen, silk fibroin, gelatin, hyaluronic acid, chitosan, and fibrinogen.

[0014] Furthermore, the cross-sectional shape of the wire includes, but is not limited to, a combination of one or more of circle, ellipse, rectangle, and trapezoid.

[0015] Aspects of the present disclosure relate to the use of a device as defined above for deployment in a lumen of the body to treat a pathology of or near a body wall defining the lumen. In various embodiments, the body wall is a blood vessel wall. In various embodiments, the blood vessel is an intracranial blood vessel. In various embodiments, the pathology is an aneurysm, cancer, infection, coronary artery disease, carotid atherosclerotic disease, or intracranial atherosclerosis.

[0016] The utility model has at least the following beneficial effects:

[0017] By mixing zinc alloy wires with a small amount of elastically deformable wires, the device can be made biodegradable as a whole, wherein the zinc alloy wires are completely degraded, while the small amount of elastically deformable wires are endothelialized, which will not cause further stimulation to the blood vessels, thereby reducing the occurrence of complications. In addition, since the zinc alloy material itself has only good developing properties and is combined with the relatively dense structure of the device, a good developing effect can be achieved without additional developing structures. It also has the characteristic of self-expansion, which is beneficial for intraoperative operations during implantation.

[0018] In order to avoid the problem that traditional coating technology cannot effectively form on the outside of the stent, the present application uses electrospinning technology to form a membrane layer. The membrane layer formed by this technology has a structure similar to the natural extracellular matrix and has a high surface area / volume ratio, which is conducive to cell adhesion, proliferation and differentiation. The membrane layer is located on the outside of the stent and is an absorbable single-layer membrane. It can optimize the blood flow direction control after the stent expands and reduce the impact of blood flow on the tumor-bearing segment.

[0019] A stent design with different densities is adopted, in which the denser section is provided with a membrane layer to further enhance the blood guiding effect. The denser segment can effectively support the membrane layer to avoid its damage, while the sparser segment can effectively reduce the impact on the blood flow direction of the branch vessels.

[0020] By adjusting the combination of electrospinning liquids, additional technical effects including drug loading can be achieved, while greatly reducing the processing difficulty and yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The use state diagram of the present application is schematically shown;

[0023] Figure 2The structural diagram of Embodiment 1 of the present application is schematically shown;

[0024] Figure 3 Schematically shows Figure 2 A partial enlarged view of the middle end;

[0025] Figure 4 The schematic diagram of the structure of another preferred embodiment of the present application is shown;

[0026] Figure 5 Schematically shows Figure 4 Schematic diagram of the cross-sectional structure cut along the axial direction.

[0027] In the figure:

[0028] 1-stent, 2-membrane layer, 3-aneurysm, 4-branched vessel. DETAILED DESCRIPTION

[0029] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation methods of the utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the technical solution, and do not indicate that the device or element referred to must have a specific orientation. Therefore, it cannot be understood as a limitation on the utility model. It should also be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or one or more intervening elements may also exist. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the following description, for the purpose of illustration and not limitation, as used herein, "lumen" refers to a cavity defined by a tubular structure in a mammal, including but not limited to blood vessels, ureters, urethra, and bile ducts. Specific details such as specific system structures and technologies are provided to provide a thorough understanding of the embodiments of the utility model; however, it should be clear to those skilled in the art that the utility model can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and methods are omitted to avoid unnecessary details that hinder the description of the utility model. Example

[0031] Figure 2 The present invention shows a degradable and self-expandable lumen implant device: a blood guiding device, the main body of which is a hollow tubular structure formed by interlacing and weaving multiple strands of wire, namely a stent 1. After being placed in the tumor-bearing segment of the blood vessel, blood can flow through the hollow inner cavity, and part of the blood flows from the grid of the stent 1 into the aneurysm 3. Since the stent 1 covers the aneurysm opening, the amount of blood flowing in is limited, and the impact of blood on the aneurysm 3 can be particularly alleviated. The wire is a zinc alloy wire and a small amount of elastically deformable wire. The small amount of elastically deformable wire can optimize the mechanical performance of the stent 1.

[0032] like Figure 1 What is shown is a schematic diagram of the use status of the present application. For similar complex vascular networks, the tumor-bearing segment is not only curved in shape, but also has numerous branch blood vessels 4, and the blood guiding device is placed therein to block the aneurysm opening, limit the blood flow into the aneurysm 3 and reduce the further impact of the blood flow on the aneurysm 3.

[0033] like Figure 2~3 As shown, in the present application, zinc alloy wires and elastically deformable wires are mixed, and the ratio of the number of zinc alloy wires to the number of elastically deformable wires is between 5:1 and 20:1. As a metal material, compared with polymer materials such as polylactic acid used in the prior art, it has higher strength and lighter weight, and the zinc alloy itself can be degraded. After a certain period of time, the zinc alloy will be completely degraded, and the elastically deformable wire can optimize the mechanics of the stent 1 and can assist the expansion of the stent 1. The mixing of the two overcomes the problem that the zinc alloy cannot automatically expand, and the amount of elastically deformable material used is small, and it exists in the form of wire, so it will be completely endothelialized after the zinc alloy is degraded, and its impact can be ignored, so there is no need to take medicine for life.

[0034] It should be noted that the cross-sectional shape of the wire includes but is not limited to: a combination of one or more of circular, rectangular, elliptical, and trapezoidal. The diameter of the zinc alloy when it is a round wire is 0.02mm~0.1mm, the width of the zinc alloy when it is a flat wire is 0.02mm~0.1mm, and the major axis diameter of the zinc alloy when it is an elliptical wire is 0.02mm~0.1mm.

[0035] In addition, although zinc alloy itself has good developing properties, the wire material of zinc alloy is relatively thin. Therefore, in the present application, the stent 1 is formed by weaving, and its developing properties are greatly improved, and no additional developing structure or developing coating is required, which greatly reduces its process and cost, and also avoids the problem of excessive cross-sectional area caused by coating the nickel-titanium alloy wire with a developing layer in the traditional technology.

[0036] Of course, the stent 1 has a clamped state and an expanded state. In the clamped state, the stent 1 can be loaded into a delivery device and delivered to a blood vessel containing an aneurysm 3 structure; after the stent 1 is delivered to a preset position in the blood vessel, the delivery device is separated from the stent 1, the restraining force acting on the stent 1 disappears, the stent 1 gradually opens, and the volume expands to the expanded state.

[0037] Specifically, the stent in the embodiment can press the stent 1 into a smaller blood vessel. When performing vascular reconstruction, it is only necessary to select a stent 1 with a suitable length and diameter and implant it into the artery according to the specific conditions of the hemangioma to be treated. After the stent 1 reaches the lesion site, the balloon dilation step is no longer required, which avoids the problem of restenosis of the blood vessel caused by radial elastic recovery after the traditional balloon dilatation stent 1 is expanded, and the operation is simpler and safer.

[0038] The wires are mixed in a non-tight weaving manner, that is, when the same wire is spirally coiled, there is a certain gap between adjacent coils, and multiple strands of wire are interlaced in spiral and anti-spiral forms to form several meshes. Of course, since the elastically deformable wire has shape memory properties, during the elastic recovery process, it drives the overall uniform self-expansion of the stent, thereby optimizing the mechanical performance of the stent.

[0039] Those skilled in the art should understand that the main body of the stent 1 can be prepared into various sizes.

[0040] In various embodiments of the present application, the elastically deformable wire material includes but is not limited to: nickel-titanium alloy wire and cobalt-chromium alloy wire. Preferably, the elastically deformable wire material in the present application is nickel-titanium alloy wire, which has shape memory properties and good compressibility.

[0041] In another preferred embodiment, a stent 1 having different density segments is involved, wherein the denser segments are located in the lesion part to enhance the blood guidance effect on the aneurysm 3, and the sparser segments are located in the part where the branch vessels are arranged to reduce the influence on the branch vessels in the complex vascular system. Those skilled in the art should understand that the stent 1 having different density segments has various specifications according to different specific usage scenarios.

[0042] Furthermore, the support 1 also includes a membrane layer, such as Figure 5 As shown, the denser segment is located in the middle of the stent 1, and the outer side of the segment is covered with a membrane layer 2, which covers the aneurysm opening of the aneurysm 3 when in use, and the membrane layer 2 covers the outer side of the stent 1. The membrane layer 2 is a biological membrane material that can promote endothelialization, which can induce thrombosis in the aneurysm 3 or the bleeding part, and promote the aneurysm 3 to rapidly shrink and reduce the space-occupying effect in the body; at the same time, it effectively adheres to endothelial cells and cell differentiation, and accelerates the proliferation of endothelialization of the vascular lesion part, which can more effectively treat vascular diseases such as aneurysms.

[0043] The present application is formed on the outside of the stent 1 by electrospinning, and the membrane layer 2 partially or completely covers the stent 1, thereby strengthening the blood flow guiding function of the stent 1, having structural characteristics similar to the natural extracellular matrix, and having a high surface area / volume ratio, which is conducive to cell adhesion, proliferation and differentiation.

[0044] In addition, the combination of the stent 1 and the membrane layer 2 can significantly reduce the blood flow into the aneurysm, and can more effectively resist the pressure of the blood flow, thereby reducing the risk of rupture of the aneurysm 3.

[0045] In the above embodiments, the film layer is made of one or more degradable polymer materials, preferably: polyglycolide, polylactic acid, polyglycolide lactide, polycaprolactone, polyglycolic acid, poly-L-glutamic acid, polyaspartic acid, polydioxanone, etc. Related copolymers or natural polymers can also be selected, preferably: collagen, silk fibroin, gelatin, hyaluronic acid, chitosan, fibrinogen, etc.

[0046] In another preferred embodiment, the membrane layer is also loaded with relevant therapeutic drugs, such as one or more blood thinners and / or antiplatelet agents such as aspirin, heparin, ticagrelor, 5-fluorouracil, clopidogrel, etc.

Claims

1. A degradable blood flow guiding device, characterized in that: The stent is a hollow tubular structure, which covers the aneurysm opening where the aneurysm is connected to the blood vessel, thereby limiting the blood flow into the aneurysm; The stent is formed by at least three wires interlaced and woven with each other, and is used to promote and / or maintain radial and / or axial expansion of the stent in the body cavity; the wires are zinc alloy wires and elastically deformable wires, and the number of zinc alloy wires is greater than the number of elastically deformable wires; A membrane layer is also arranged outside the support, and the membrane layer partially or completely covers the outside of the support.

2. A degradable blood flow guiding device according to claim 1, characterized in that: The stent is a non-tightly woven structure formed by mixing multiple strands of wire materials, and the ratio of the number of zinc alloy wires to the number of elastically deformable wires in the wire materials is between 5:1 and 20:

1.

3. A degradable blood flow guiding device according to claim 2, characterized in that: The non-tightly braided structure is a hollow tubular body formed by interlacing and braiding multiple strands of wire in a spiral and reverse spiral form.

4. A degradable blood flow guiding device according to claim 3, characterized in that: When the same wire is spirally wound into a hollow tubular body, a certain gap is left between adjacent turns.

5. The degradable blood flow guiding device according to claim 1, characterized in that: The stent has segments with different densities, wherein the outer sides of the denser segments are covered with a membrane layer.

6. The degradable blood flow guiding device according to claim 1, characterized in that: The cross-sectional shape of the wire includes, but is not limited to, a combination of one or more of a circle, an ellipse, a rectangle, and a trapezoid.

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