A stent system for sustainable drug delivery

Abstract

The present application relates to the field of medical device technology, and more particularly to a stent system capable of sustained drug delivery. The stent system comprises a coated stent and an infusion catheter. The coated stent is coated with an inner membrane and an outer membrane, forming a liquid reservoir between the inner and outer membranes for storing drugs. The outer membrane is provided with a liquid outlet, through which the drug can seep out, achieving sustained drug release. The liquid outlet of the infusion catheter is inserted into the liquid reservoir to infuse the liquid reservoir. This stent system can achieve sustained drug release, effectively resolving the problem of drug retention during digestive tract drug delivery.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a stent system for sustainable drug delivery. Background Art

[0002] In the medical field, endoscopic treatment methods are often used. Endoscopic treatment includes endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR). ESD is relatively mature in the treatment of early gastric cancer, and it also has advantages such as a higher en bloc resection rate and no restrictions on the scope of the lesion. Therefore, it is more widely used than EMR.

[0003] Currently, ESD treatment has been extended to the treatment of early-stage esophageal cancer. However, since digestive tract stenosis often occurs after ESD surgery and affects the patient's quality of life, how to prevent digestive tract stenosis after ESD or prolong the time of stenosis is the focus of esophageal cancer patients after ESD surgery. Currently, commonly used prevention methods include: oral or local injection of steroid hormones, endoscopic balloon dilation (EBD), use of polyglycolic acid mesh, stent implantation, etc., and the above methods can also be used in combination. Due to the limited preventive effect of the above methods, some patients still develop stenosis after a certain period of time. For patients who have already developed stenosis, balloon dilation, endoscopic double-channel local muscle incision or surgical intervention are needed to relieve the stenosis.

[0004] All of the above methods have certain limitations. For example, the use of steroid hormones alone can delay the occurrence of stenosis, but cannot prevent the occurrence of stenosis. Excessive use of steroid hormones can cause patients to have adverse reactions such as glucose metabolism disorders, cardiovascular disease, and osteoporosis. When using polyacetic acid mesh, it often needs to be used in conjunction with other means, and the effect is only equivalent to hormone treatment. When using a balloon or dilator for dilation after stenosis, multiple dilations are often required, and the recurrence rate is high, which often brings more inconvenience to doctors and patients.

[0005] At the same time, with the concept of clinical advancement of treatment, such as chemotherapy and radiotherapy, it is often necessary to implant or inject chemotherapy drugs into the tumor site. However, due to the cavity structure of the digestive tract, the drugs are often difficult to retain for chemotherapy and radiotherapy of the tumor. The present invention aims to provide a digestive tract stent for storing drugs. While being fixed and supported in the digestive tract (such as the bile duct and intestine), the drug storage cavity can continuously release drugs (such as paclitaxel, gatacillin, aspirin, etc.) to inhibit the proliferation of tumor granulation. Summary of the Invention

[0006] The purpose of the present application is to provide a stent system with sustainable drug delivery to solve the technical problem that existing treatment methods are poorly effective in preventing gastrointestinal stenosis after ESD surgery.

[0007] The present application provides a stent system for sustainable drug delivery, comprising:

[0008] A covered stent, which is covered with an inner membrane and an outer membrane, the outer membrane covering and connecting to the inner membrane, forming a liquid storage cavity between the inner membrane and the outer membrane, and the outer membrane is provided with a liquid outlet hole, and the liquid in the liquid storage cavity can seep out from the liquid outlet hole; and

[0009] The liquid outlet is inserted into the liquid injection conduit of the liquid storage cavity.

[0010] Furthermore, the coated stent includes a proximal end and a distal end, the liquid storage cavity is located at the proximal end, and the outer membrane covers the proximal end.

[0011] Furthermore, the distal end of the injection catheter extends into the liquid storage cavity, the distal end is provided with the liquid outlet, and the body of the injection catheter is fixedly connected to the stent graft.

[0012] The proximal end of the injection catheter is used to connect with the syringe connector.

[0013] Furthermore, the tube body is fixedly connected to the stent mesh of the stent graft by means of sutures; and / or

[0014] The interface between the liquid storage cavity and the liquid outlet is sealed.

[0015] Furthermore, the axial distance from the interface between the liquid storage cavity and the liquid outlet to the proximal edge of the stent graft is less than 1 / 3 of the axial spacing of the liquid storage cavity.

[0016] Furthermore, the injection catheter includes a distal section and a proximal section that are separately connected to each other, the distal section is fixedly connected to the stent mesh of the coated stent, and the proximal section is used to connect to the syringe connector.

[0017] Furthermore, the distal segment and the stent graft are integrally vulcanized; and / or

[0018] The distal end section is made of high temperature resistant material.

[0019] Furthermore, in the implantation direction of the stent graft, the outer membrane covers the upper middle portion of the stent graft; and / or

[0020] The edge of the outer film is sealed and bonded to the inner film; and / or

[0021] The inner membrane and / or the outer membrane of the stent graft are made of polymer film material.

[0022] Furthermore, the outer membrane circumferentially covers the proximal end of the coated stent.

[0023] Furthermore, a plurality of liquid outlet holes are evenly arranged around the outer membrane.

[0024] Furthermore, the liquid outlet holes are micropores or capillaries, and the pore diameter thereof is less than 2 mm.

[0025] Furthermore, the structure of the coated stent is in the shape of a dumbbell, with flared ends at both ends, located at the proximal end and the distal end respectively.

[0026] Compared with the existing technology, the sustainable drug delivery stent system provided in the present application is implanted into the patient's digestive tract, and includes a coated stent. The proximal end of the coated stent is close to the human oral cavity, and the distal end is far away from the human oral cavity. The coated stent can give a certain mechanical stimulation to the digestive tract after surgery. At the same time, it is covered with an inner membrane and an outer membrane. The inner membrane can effectively prevent the internal growth of the digestive tract mucosa. A liquid storage cavity is formed between the inner membrane and the outer membrane. The amount of drug solution required to effectively prevent digestive tract stenosis during ESD surgery of the patient is first injected into the liquid storage cavity through the injection device through the injection catheter, and then continuously seeps out a little bit from the liquid outlet hole of the outer membrane, and then slowly infiltrates the wound surface under the action of downward gravity. This method can control the injection amount of the drug solution and ensure the uniformity of drug delivery. It also ensures effective drug input and effectively prevents postoperative stenosis. At the same time, it continuously infuses the wound surface, controls the infiltration rate of the drug solution, greatly prolongs the drug administration time, reduces drug stimulation, and effectively avoids the adverse reactions such as sugar metabolism disorders, cardiovascular disease, osteoporosis, etc. caused by excessive use of steroid hormones and other drugs at a time, greatly improving the treatment effect of preventing gastrointestinal stenosis after ESD surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 A schematic diagram of the overall structure of a support system provided in one embodiment of the present application;

[0029] Figure 2 An enlarged view of a portion of the structure of the support system provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of a partial structure of the support system provided in an embodiment of the present application;

[0031] Figure 4 This is a schematic diagram of the overall structure of a support system provided in another embodiment of the present application.

[0032] Reference numerals:

[0033] 10-Stent Graft;

[0034] 11-proximal;

[0035] 12-distal;

[0036] 13-middle section;

[0037] 14-intima;

[0038] 15-grid bracket;

[0039] 20-outer membrane;

[0040] 21- liquid outlet;

[0041] 30-infusion catheter;

[0042] 31-liquid outlet;

[0043] 321-distal segment;

[0044] 322-proximal segment;

[0045] 33- injection catheter docking port;

[0046] 34-suture;

[0047] 40-Syringe connector;

[0048] 41-air valve;

[0049] 42-Air intake. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0052] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0053] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0055] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0056] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0057] like Figures 1 to 4As shown, an embodiment of the present application provides a stent system for sustainable drug delivery, which includes a coated stent 10, wherein the end of the coated stent 10 close to the human oral cavity is a proximal end 11, the end away from the human oral cavity is a distal end 12, and the middle section 13 is between the proximal end 11 and the distal end 12. The coated stent 10 includes a grid stent 15 and an inner membrane 14 covering, bonding and adhering to the outer periphery of the grid stent 15, and an outer membrane 20 covering and connected to the inner membrane 14. The edge of the outer membrane 20 can be sealed and bonded to the inner membrane 14. The grid stent 15 has a stent mesh. The coated stent 10 can be vulcanized and formed at high temperature. A liquid storage cavity is formed between the inner membrane 14 and the outer membrane 20. A liquid outlet 21 is opened on the outer membrane 20. The liquid medicine in the liquid storage cavity can seep out from the liquid outlet 21. The liquid medicine can specifically be paclitaxel, cisplatin, aspirin, steroid hormones, etc.

[0058] Preferably, the aforementioned liquid storage cavity is located at the proximal end 11 of the coated stent 10, and the outer membrane 20 is coated on the proximal end 11, that is, it is arranged as close to the entrance of the digestive tract as possible to maximize the coverage of the wound surface that can be infiltrated. In addition, because the liquid storage cavity is located at the proximal end 11 of the coated stent 10, it is convenient for the drug solution to infiltrate the entire wound surface under the action of gravity after it seeps out. If the liquid storage cavity covers the entire coated stent 10, this effect cannot be achieved. Because if the liquid storage cavity covers the entire coated stent 10, when the drug in the liquid storage cavity decreases, the drug will accumulate at the distal end of the liquid storage cavity, that is, the distal end 12 area of ​​the coated stent 10. Then, after the drug seeps out, the drug cannot flow back to the proximal end 11 area of ​​the coated stent 10 due to gravity, and the drug cannot be administered to the proximal wound surface.

[0059] The stent system may further include an infusion conduit 30, the outlet 31 of which is inserted into the liquid reservoir for infusing the reservoir. Preferably, the distal end of the infusion conduit 30 extends into the liquid reservoir and may include the outlet 31, enabling more targeted infusion. The proximal end of the infusion conduit 30 may be adapted to interface with a syringe connector 40, which may include an air valve 41 and an air inlet 42 for delivering medication, controlling drug dosage, and adjusting infusion rate.

[0060] Compared with the prior art, the sustainable drug delivery stent system provided in the embodiment of the present application is implanted into the patient's digestive tract, and includes a coated stent 10. The proximal end 11 of the coated stent 10 is close to the human oral cavity, and the distal end 12 is away from the human oral cavity. The coated stent 10 can give a certain mechanical stimulation to the digestive tract after surgery. At the same time, it is covered with an inner membrane 14 and an outer membrane 20. The inner membrane 14 can effectively prevent the internal growth of the digestive tract mucosa; a liquid storage cavity is formed between the inner membrane 14 and the outer membrane 20. The amount of drug solution required to effectively prevent digestive tract stenosis during ESD surgery of the patient is first injected into the liquid storage cavity through the injection device through the injection catheter 30, and then continuously seeps out a little bit from the liquid outlet 21 of the outer membrane 20, and then slowly infiltrates the wound surface under the action of downward gravity. This method can control the injection amount of the drug solution while ensuring the uniformity of drug delivery. It also ensures effective drug input and effectively prevents postoperative stenosis. At the same time, it continuously infuses the wound surface, controls the infiltration rate of the drug solution, greatly prolongs the drug administration time, reduces drug stimulation, and effectively avoids the adverse reactions such as sugar metabolism disorders, cardiovascular disease, osteoporosis, etc. caused by excessive use of steroid hormones and other drugs at a time, greatly improving the treatment effect of preventing gastrointestinal stenosis after ESD surgery.

[0061] Furthermore, the distal end of the aforementioned injection catheter 30 can extend into the aforementioned liquid storage cavity, and the tube body can be sutured and fixedly connected to the stent mesh of the aforementioned stent graft 10 at the suture point 34 by means of sutures, such as Figure 3 As shown, it can be sutured and fixed to the inner membrane 14 of the coated stent 10, and inserted into the stent mesh of its grid support 15 for fixed connection, so as to strengthen the fixation of the distal liquid outlet 31 side of the infusion catheter 30. In order to prevent the drug solution from leaking out of the liquid outlet 31, the interface where the infusion catheter 30 penetrates into the liquid storage cavity can be sealed.

[0062] Preferably, the axial distance between the interface between the liquid reservoir and the liquid outlet 31 of the injection catheter 30 and the edge of the proximal end 11 of the stent graft 10 can be less than 1 / 3 of the axial spacing of the liquid reservoir. This can reduce the axial overlap between the injection catheter 30 and the stent graft 10, making it easier for the stent graft to be compressed into an implant with a smaller outer diameter.

[0063] Further, such as Figure 4As shown, the aforementioned injection catheter 30 may include a distal section 321 and a proximal section 322 that can be separably connected. The distal section 321 can be fixedly connected to the stent mesh of the aforementioned coated stent 10, and the proximal section can be connected to the syringe street 40. The separate connection can facilitate independent molding and separate placement. The distal section 321 and the proximal section 322 can be docked through the injection catheter docking port 33. The proximal section 322 can be connected with a longer catheter. The distal section 321 can be made of a high-temperature resistant material that can withstand a high-temperature environment of more than 80°C. It can be vulcanized and molded integrally with the coated stent 10. The two can be fixed together first, so that they can be vulcanized and molded together in an oven when the coated stent 10 is coated. The high-temperature resistant material is not afraid of the high-temperature environment in the oven. After the coating is completed, it can be docked with the proximal section 322 to form a complete injection catheter 30. In this way, when the distal end section 321 of the injection catheter is connected to the coated stent 10, it can be put into the oven for vulcanization and silicone film sealing treatment again, and at the same time, the distal end section 321 only needs to be resistant to high temperature.

[0064] Furthermore, in the implantation direction of the stent graft 10, the outer membrane 20 can cover the upper and middle part of the stent graft 10, covering 0 to 1 / 2 of the stent graft, which can further effectively cover the drug solution infiltration surface.

[0065] Furthermore, the outer membrane 20 can be circumferentially wrapped around the proximal end 11 of the stent graft 10. This can, on the one hand, increase the liquid storage space of the liquid reservoir, thereby effectively increasing the amount of drug stored, further extending the drug administration time, reducing drug stimulation, and improving the therapeutic effect. On the other hand, the outer membrane 20 is circumferentially arranged around the proximal end 11 of the stent graft 10, eliminating the need to accurately determine the specific location of the wound in advance, or to adjust the position of the stent after it enters the digestive tract to prevent further unnecessary trauma to the digestive tract. Instead, it is only necessary to determine the approximate location and ensure that any corresponding surface of the stent midsection and the distal end below corresponds to the wound location.

[0066] Furthermore, the aforementioned outer membrane 20 may be uniformly provided with a plurality of the liquid outlet holes 21 around the circumference. The liquid medicine seeping out of the liquid outlet holes 21 can penetrate into the wound surface due to the action of gravity, effectively infiltrating the wound surface, and effectively preventing the patient's digestive tract from being damaged unnecessary and preventing the patient from suffering unnecessary pain. The liquid outlet holes 21 may be specifically located outside the middle area of ​​the coated stent 10. Not only can the liquid discharge be more uniform, but it can also further effectively correspond to the wound surface position, so that the liquid medicine seeping out of the liquid outlet holes 21 can directly penetrate into the wound surface or be located directly above the wound surface and can penetrate nearby, thereby increasing the infiltration efficiency and improving the therapeutic effect.

[0067] In one specific embodiment, the liquid outlet 21 can be a micropore with a very small pore size or a capillary pore with an even smaller pore size, such as less than 2 mm. This further prolongs the drug delivery time, improves sustainability, further reduces drug irritation, and enhances therapeutic efficacy. In another specific embodiment, the inner membrane 14 and / or the outer membrane 20 of the stent graft 10 can be made of a polymer membrane material such as silicone or PTFE.

[0068] In another specific embodiment, the stent graft 10 may be shaped like a dumbbell, a trumpet, a cup, a sphere, or a right cylindrical shape. Preferably, the dumbbell-shaped structure has flared ends, which can relatively increase the liquid storage space of the liquid storage cavity between the inner membrane 14 and the outer membrane 20.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A stent system for continuous drug delivery, characterized in that: include: A covered stent comprises a lattice stent, an inner membrane covering the periphery of the lattice stent, and an outer membrane covering and connected to the inner membrane, wherein a liquid storage cavity is formed between the inner membrane and the outer membrane, and a liquid outlet hole is formed on the outer membrane, through which the liquid in the liquid storage cavity can seep out; and The liquid outlet is inserted into the liquid injection catheter of the liquid storage cavity; The stent graft comprises a proximal end and a distal end, wherein the end of the stent graft close to the human oral cavity is the proximal end, and the end away from the human oral cavity is the distal end, the liquid storage cavity is located at the proximal end, and the outer membrane covers the proximal end; The distal end of the injection catheter extends into the liquid storage cavity, the distal end is provided with the liquid outlet, and the body of the injection catheter is fixedly connected to the stent graft; the interface between the liquid storage cavity and the liquid outlet is sealed; The proximal end of the injection catheter is used to connect to the syringe connector; the drug solution is injected into the liquid storage cavity through the injection catheter by the injection device, continuously seeps out from the liquid outlet hole of the outer membrane, and then infiltrates the entire wound surface under the downward action of gravity.

2. The bracket system according to claim 1, wherein: The tube body is fixedly connected to the stent mesh of the stent graft by means of sutures.

3. The bracket system according to claim 1, wherein: The axial distance from the interface between the liquid storage cavity and the liquid outlet to the proximal edge of the stent graft is less than 1 / 3 of the axial spacing of the liquid storage cavity.

4. The bracket system according to claim 1, wherein: The injection catheter includes a distal section and a proximal section that are separately connected to each other. The distal section is fixedly connected to the stent mesh of the coated stent, and the proximal section is used to connect to the syringe connector.

5. The support system according to claim 4, wherein: The distal segment and the stent graft are integrally vulcanized; and / or The distal end section is made of high temperature resistant material.

6. The support system according to claim 1, wherein: In the implantation direction of the stent graft, the outer membrane covers the upper middle portion of the stent graft; and / or The edge of the outer film is sealed and bonded to the inner film; and / or The inner membrane and / or the outer membrane of the stent graft are made of polymer film material.

7. The bracket system according to claim 1, wherein: The outer membrane circumferentially covers the proximal end of the stent graft.

8. The support system according to claim 7, wherein: A plurality of liquid outlet holes are evenly arranged around the outer membrane.

9. The support system according to claim 8, wherein: The liquid outlet hole is a micropore with a pore diameter less than 2 mm.

10. The support system according to claim 1, wherein: The stent graft has a dumbbell-shaped structure, with enlarged ends at both ends, located at the proximal end and the distal end respectively.

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