A biodegradable vascular embolism

Abstract

The present invention relates to a biodegradable vascular embolism body, belonging to the technical field of medical devices. The embolism body has a linear structure, and is sequentially provided with a core layer, a main body layer, a procoagulant layer and a self-expanding material coating from the inside to the outside along the radial direction; the core layer, the main body layer, the procoagulant layer and the self-expanding material coating include absorbable materials; the core layer includes a developer. The vascular embolism body provided by the present invention has good passability and can be imaged, and can reach the vascular perforation site in a timely and accurate manner; it can be fixed at the vascular target point to avoid displacement caused by blood flow impact, thereby minimizing the potential impact of the embolism body on non-perforated blood vessels and avoiding the expansion of the area of iatrogenic myocardial infarction. The vascular embolism body uses biodegradable materials to avoid potential safety hazards caused by long-term indwelling of foreign bodies in the human body.

Description

Technical Field

[0001] The present invention relates to a biodegradable vascular embolism body, belonging to the technical field of medical devices. Background Art

[0002] Coronary atherosclerotic heart disease (CHD) is an ischemic heart disease caused by the progression of atherosclerotic lesions leading to stenosis or occlusion of the coronary artery lumen, and is one of the main diseases endangering people's lives and health. Coronary intervention has become the main means for CHD patients to relieve symptoms, improve prognosis and enhance the quality of life due to its advantages such as definite curative effect, minimal trauma and rapid postoperative recovery. Coronary perforation is the rupture of the coronary artery wall caused by various reasons during the interventional procedure, resulting in blood flowing outside the blood vessel through the damaged vessel wall. Previous studies have shown that the incidence of coronary perforation during coronary intervention ranges from 0.1% to 0.9%, which can cause serious complications such as acute cardiac tamponade and acute myocardial infarction, reducing the success rate of coronary intervention and increasing the risk of emergency coronary artery bypass grafting. If not detected in time or treated improperly, it can even endanger the patient's life, with a maximum mortality rate of up to 9%.

[0003] Currently, the main treatment methods for occluding coronary perforation in clinical practice include: continuous low-pressure balloon dilation to occlude the perforation, implantation of covered stents locally at the perforation site, vascular embolization, and surgical repair. For continuous low-pressure balloon dilation, the balloon needs to be sent to the proximal part of the perforation site and dilated at a pressure of 2-6 atm, and the dilation time is determined according to the patient's tolerance for 10-30 minutes. The efficacy of this method is uncertain, and it is mostly used in clinical practice to temporarily control bleeding and gain time for subsequent treatment. Covered stents are mainly used for occluding large proximal vessel perforations. However, due to the poor passability of covered stents, they often fail to reach the occluding site in calcified or tortuous lesions, resulting in occlusion failure. At the same time, the risk of in-stent restenosis significantly increases after the implantation of covered stents. The vascular embolization method is mainly applicable to distal vessel perforations with a smaller diameter. Currently, there is still a lack of targeted embolization materials in clinical practice. Commonly used embolization materials include microcoils, gelatin sponges, and autologous adipose tissue. Gelatin sponges and autologous adipose tissue cannot be visualized under X-rays, with poor visibility and blind operation. They often require multiple repeated embolizations, and may even cause embolization of non-perforated vessels, expanding the area of myocardial necrosis. Coils have the advantage of visibility, but due to the rigidity of the metal itself, there are still difficulties in releasing them in tortuous vessels and extremely distal small vessels. They do not have biocompatibility, and there are potential hazards in leaving foreign bodies in the coronary artery for a long time. More importantly, coils lack self-expansion function, and their procoagulant effect is not as good as that of gelatin sponges and autologous adipose tissue. There are often escape phenomena during use, resulting in incomplete occlusion. Therefore, aiming at the deficiencies in vascular embolization technology in the existing technology, there is an urgent need in this technical field to obtain a bioabsorbable vascular embolization body, which not only has good passability, can reach the vascular perforation site in time to play a role, but also enables medical staff to accurately release the embolization material under X-ray fluoroscopy and quickly and effectively embolize the target vessel. Summary of the Invention

[0004] The object of the present invention is to solve the technical problem of how to obtain a bioabsorbable vascular embolization body, which not only has good passability, can reach the vascular perforation site in time to play a role, but also enables medical staff to accurately release it under X-ray fluoroscopy and quickly and effectively embolize the target vessel.

[0005] To achieve the above object, the technical solution adopted by the present invention is to provide a bioabsorbable vascular embolization body. The embolization body has a linear structure, and a core layer, a main body layer, a procoagulant layer, and a self-expanding material coating are sequentially arranged from the inside to the outside along the radial direction; the core layer, the main body layer, the procoagulant layer, and the self-expanding material coating include absorbable materials; the core layer includes a contrast agent.

[0006] Preferably, the self-expanding material coating is axially arranged in the middle part of the outer periphery of the procoagulant layer.

[0007] Preferably, part of the procoagulant layer is arranged on the outer surface of the embolization body.

[0008] Preferably, the core layer comprises a mixture of an absorbable polymer material and a developer.

[0009] Preferably, the absorbable polymer material of the core layer comprises polyglycolic acid, polycaprolactone or p-dioxanone.

[0010] Preferably, the developer is barium sulfate.

[0011] Preferably, the absorbable material of the main body layer comprises polyglycolic acid, polycaprolactone or p-dioxanone.

[0012] Preferably, the coagulation promoting layer comprises chitosan, chitosan derivatives, human blood coagulation factor or thrombin.

[0013] Preferably, the self-expanding material coating comprises polyethylene glycol, chitosan or sodium carboxymethylcellulose.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention provides a flexible vascular embolization device with good passability, which can quickly pass through complex vascular lesions such as tortuous and calcified vessels with the assistance of a microcatheter and reach the vascular perforation site in time to play its function.

[0016] 2. The vascular embolization body provided by the present invention is provided with an X-ray developable material, which enables medical staff to accurately release the embolization body under X-ray fluoroscopy. The outermost self-expanding coating of the embolization body fixes the released embolization body at the vascular target point, avoiding the displacement of the device caused by blood flow impact, thereby minimizing the potential impact of the embolization body on non-perforated blood vessels and avoiding the expansion of the area of iatrogenic myocardial infarction.

[0017] 3. All the vascular embolization bodies provided by the present invention are made of bioabsorbable materials. After completing the vascular embolization function, the embolization bodies are completely degraded into carbon dioxide, water, urea, amino acids and other substances within 2-3 months, avoiding potential safety hazards caused by long-term indwelling of foreign bodies in the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional structure diagram of a bioabsorbable vascular embolization body of the present invention.

[0019] Figure 2 It is a schematic longitudinal sectional structure diagram of a bioabsorbable vascular embolization body of the present invention.

[0020] Reference numerals: 1. Core layer; 2. Main body layer; 3. Coagulation promoting layer; 4. Self-expanding material coating. DETAILED DESCRIPTION OF THE INVENTION

[0021] To make the present invention more obvious and understandable, the following is a detailed description of preferred embodiments:

[0022] As Figure 1 , shown in FIG. 2, the present invention provides a bio - degradable vascular embolism body. The embolism body has a linear structure, and from the inside to the outside along the radial direction, there are a core layer 1, a main body layer 2, a coagulation - promoting layer 3, and a self - expanding material coating 4 in sequence; the core layer 1, the main body layer 2, the coagulation - promoting layer 3, and the self - expanding material coating 4 include absorbable materials; the core layer 1 includes a developer. The self - expanding material coating 4 is axially disposed in the middle part of the outer periphery of the coagulation - promoting layer 3. Part of the coagulation - promoting layer 3 is disposed on the outer surface of the embolism body. The core layer 1 includes a mixture composed of an absorbable polymer material and a developer. The absorbable polymer material of the core layer 1 includes polyglycolic acid, polycaprolactone, or p - dioxanone; the developer is barium sulfate. The absorbable material of the main body layer 2 includes polyglycolic acid, polycaprolactone, or p - dioxanone. The coagulation - promoting layer 3 includes chitosan, chitosan derivatives, human coagulation factor, or thrombin. The self - expanding material coating 4 includes polyethylene glycol, chitosan, or sodium carboxymethylcellulose.

[0023] Currently, commonly used coronary embolism materials in clinical practice include micro - coils, gelatin sponges, and autologous adipose tissue, etc. During the use of these materials, there are disadvantages such as poor passability, lack of biocompatibility, and poor visibility, which not only affect the efficiency of vascular embolism, but may even cause embolism of non - target blood vessels, leading to an increase in the area of myocardial necrosis. The present invention aims at the above - mentioned deficiencies of the prior art and specifically designs a new type of vascular embolism device. The flexible linear structure ensures that the device has good passability, adding a developer component improves the visibility of the device, using bio - degradable materials realizes complete biocompatibility, and at the same time, the use of coagulation - promoting materials and self - expanding materials ensures the embolism efficiency and avoids the "escape phenomenon".

[0024] To overcome the deficiencies of the prior art, the present invention provides a bio - degradable vascular embolism body. The vascular embolism body has a linear structure, and its cross - section includes a four - layer wrapping structure of a core layer, a main body layer, a coagulation - promoting layer, and a self - expanding material coating from the inside to the outside; the central area of the core layer is a mixture of an absorbable polymer material and a developer; the main body layer is a flexible absorbable synthetic thread; the coagulation - promoting layer is an absorbable material; the self - expanding material coating is located in the middle section outside the coagulation - promoting layer.

[0025] The absorbable polymer materials that make up the core layer include polyglycolic acid, polycaprolactone, p - dioxanone, and the developer is barium sulfate;

[0026] The absorbable polymer materials that make up the main body layer include polyglycolic acid, polycaprolactone, p - dioxanone; the above - mentioned polymer materials are commonly used materials in products such as tissue engineering scaffolds and sutures, and can be degraded and completely absorbed in the human body.

[0027] Optional materials for the procoagulant layer include chitosan, carboxymethyl chitosan, carboxyethyl chitosan, human coagulation factor, and thrombin. Among them, chitosan and its derivatives have a natural positively charged group, amino group, which can promote red blood cell aggregation and induce thrombus formation. Chitosan and its derivatives can be gradually degraded in the human body to form small molecule monosaccharides and then be absorbed by the human body; human coagulation factor and thrombin are commonly used procoagulant drugs in clinical practice.

[0028] Optional materials for the self-expanding material coating include polyethylene glycol, chitosan, sodium carboxymethyl cellulose, or a hydrogel layer made by chemically cross-linking the above materials. Chitosan and its derivatives, and sodium carboxymethyl cellulose generally have good hydrophilicity and solubility. The hydrogel layer formed by chemical cross-linking can retain its original shape, absorb water, and play the effect of volume expansion.

[0029] Such as Figure 1 and Figure 2 As shown in

[0030] The innermost core layer 1 of the present invention uses an absorbable polymer material, polyglycolic acid, and a developer, barium sulfate; the absorbable synthetic thread of the second main layer 2 uses polyglycolic acid; the procoagulant layer 3 selects chitosan; chitosan and its derivatives have a natural positively charged group, amino group, which can promote red blood cell aggregation and induce thrombus formation. Chitosan and its derivatives can be gradually degraded in the human body to form small molecule monosaccharides and then be absorbed by the human body; the material used for the self-expanding material coating 4 is chitosan; chitosan and its derivatives, and sodium carboxymethyl cellulose have good hydrophilicity and solubility. The hydrogel layer formed by chemical cross-linking can retain its original shape, absorb water, and play the effect of volume expansion.

[0031] Use of the present invention:

[0032] When coronary distal perforation occurs, a microcatheter is sent along the coronary guide wire to the proximal part of the perforation site, the coronary guide wire is withdrawn, and under X-ray fluoroscopy through the microcatheter, the vascular embolism is sent to the perforation site. After the embolism reaches the vascular perforation, it contacts the human blood. The middle section of the outermost layer of the embolism undergoes self-expansion, blocks and fixes at the vascular target point and blocks blood flow. The third procoagulant coating induces local thrombus formation and completely blocks the perforated blood vessel.

[0033] Subsequently, the constituent materials of the embolism body break the molecular chains and reduce the molecular weight in the human body, gradually becoming oligomers or monomers, and then are completely absorbed by the human body and enter the normal metabolic process of the human body. The final degradation products include carbon dioxide, water, urea, and amino acids.

[0034] As described above, only the preferred embodiments of the present invention are provided, and there is no limitation in any form or substance to the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any equivalent changes in the form of slight modifications and evolutions made by those skilled in the art who are familiar with this specialty without departing from the spirit and scope of the present invention by using the technical content disclosed above are equivalent embodiments of the present invention; at the same time, any equivalent changes in the form of modifications and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solutions of the present invention.

Claims

1. A biodegradable vascular embolization body for a vascular perforation site, characterized in that, The embolus has a linear structure, and a core layer, a main body layer, a coagulation-promoting layer, and a self-expanding material coating are sequentially provided from the inside to the outside in the radial direction; absorbable materials are included in the core layer, the main body layer, the coagulation-promoting layer, and the self-expanding material coating; a developer is included in the core layer; The self-expanding material coating is axially provided at the middle part of the outer periphery of the coagulation-promoting layer; The self-expanding material coating includes polyethylene glycol, chitosan, or sodium carboxymethylcellulose; After the embolus reaches the vascular perforation and contacts the human blood, the middle section of the outermost layer of the embolus undergoes self-expansion, is blocked and fixed at the vascular target point, and blocks blood flow. The third layer of coagulation-promoting coating induces local thrombus formation to completely block the perforated blood vessel.

2. The bio - degradable vascular embolism body according to claim 1, characterized in that, Part of the coagulation-promoting layer is provided on the outer surface of the embolus.

3. The bio - degradable vascular embolism body according to claim 1, characterized in that, The core layer includes a mixture composed of an absorbable polymer material and a developer.

4. A biodegradable vascular embolism body according to claim 3, characterized in that, The absorbable polymer material of the core layer includes polyglycolic acid, polycaprolactone, or p-dioxanone.

5. A biodegradable vascular embolism body according to claim 3, characterized in that, The developer is barium sulfate.

6. The biodegradable vascular embolism body according to claim 1, characterized in that, The absorbable material of the main body layer includes polyglycolic acid, polycaprolactone, or p-dioxanone.

7. A biodegradable vascular embolism body according to claim 1, characterized in that, The coagulation-promoting layer includes chitosan, chitosan derivatives, human coagulation factor, or thrombin.

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