Cavity stent

Abstract

The utility model discloses a cavity stent, and relates to the technical field of medical instruments. The cavity stent comprises a metal wire, a covering film, a tearing belt and an adhesion layer, wherein the metal wire is spirally constructed into a tubular metal framework with a set diameter. The covering film is fixed to the outer side and / or the inner side of the tubular metal framework. The tearing belt is wound on the covering film in a spiral shape and does not intersect with the metal wire. The adhesion layer is arranged on the outer side of the covering film, the adhesion layer comprises an anti-adhesion layer in direct contact with the wall of the cavity and an adhesive layer located between the anti-adhesion layer and the covering film, the anti-adhesion layer can be naturally degraded in the cavity, and the adhesive layer can be naturally degraded and / or emergently released from adhesion in the cavity. And the natural degradation time of the adhesive layer is longer than that of the anti-sticking layer. According to the cavity stent, under the normal condition, the cavity stent does not shift in a cavity, and restenosis and blockage of the cavity cannot be caused; and the stent can be smoothly removed when emergently removed, so that the harm to a patient is reduced.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a cavity stent. Background Technology

[0002] Medical implantable stents can relieve narrowing of body cavities and alleviate various discomforts caused by narrowing. However, after implantation, some stents may shift in their target position due to factors such as cavity peristalsis, fluid flushing, and changes in body position. Once the stent shifts from its target position, it loses its support effect on the narrowed segment, leading to surgical failure. Utility Model Content

[0003] The purpose of this invention is to provide a cavity stent that, under normal circumstances, does not shift within the cavity and does not cause restenosis or blockage; it can also be easily removed when emergency removal is required, reducing harm to the patient.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] Cavity stents, comprising:

[0006] Metal wire, the metal wire being spirally constructed into a tubular metal skeleton with a set diameter;

[0007] A film is fixed to the outside and / or inside of the tubular metal skeleton;

[0008] The tear strip is spirally wound around the coating, and the tear strip does not intersect with the metal wire;

[0009] An adhesive layer is disposed on the outside of the coating, the adhesive layer comprising an anti-adhesive layer in direct contact with the wall of the cavity and an adhesive layer located between the anti-adhesive layer and the coating;

[0010] The anti-adhesive layer is capable of natural degradation within the cavity, the adhesive layer is capable of natural degradation and / or emergency release within the cavity, and the natural degradation time of the adhesive layer is longer than that of the anti-adhesive layer.

[0011] As an alternative to the cavity support, the anti-adhesive layer does not adhere to the wall of the cavity, so that the cavity support can move to the target position within the cavity.

[0012] As an alternative to the cavity support, the adhesive layer can adhere to the wall of the cavity, so that an adhesive force is generated between the adhesive layer and the wall of the cavity to fix the cavity support.

[0013] As an alternative to the cavity stent, the adhesion force is 0.1 N / cm to 5 N / cm.

[0014] As an alternative to the cavity stent, the adhesive layer is disposed partially or entirely on the outside of the membrane.

[0015] As an alternative to the cavity support, when the adhesive layer is locally disposed on the outside of the membrane, it is distributed continuously or intermittently along the tear strip.

[0016] As an alternative to the cavity support, the adhesive layer includes a temperature-sensitive polymer that can cause the adhesion between the adhesive layer and the wall of the cavity to disappear when an aqueous solution at a set temperature is introduced.

[0017] As an alternative to the cavity stent, the natural degradation time of the anti-adhesive layer is 1 hour to 3 days, and the natural degradation time of the adhesive layer is 3 days to 1 year.

[0018] As an alternative to the cavity stent, the anti-adhesion layer comprises a biodegradable material, which may be selected from: PLGA, hyaluronic acid, deacetylated chitosan, quaternized chitosan, carboxymethyl chitosan, type I collagen, carboxymethyl chitosan, regenerated oxidized cellulose, oxidized cellulose, dextran, starch, collagen, and gelatin.

[0019] As an alternative to the cavity stent, the metal wire is made of any one of nickel-titanium alloy, stainless steel, tantalum or platinum-iridium alloy.

[0020] As an alternative to the cavity support, the metal wire is one or a combination of straight and wavy shapes.

[0021] The beneficial effects of this utility model are:

[0022] The cavity stent provided by this invention comprises a tubular metal skeleton with a predetermined diameter, constructed by spiraling metal wires. This skeleton provides support for narrowed cavities and prevents tissue ingrowth into the stent. A spiral tear strip, not intersecting with the metal wires, is wound around a membrane fixed to the outer and / or inner side of the tubular metal skeleton. The stent is then bonded to the cavity wall via an adhesive layer in an adhesive layer on the outer side of the membrane, thus securing its position within the cavity and preventing displacement. This effectively supports narrowed cavities and alleviates discomfort caused by stenosis. After reaching its intended service life, the membrane can be torn along the tear strip under tension, allowing the tubular metal skeleton to disintegrate and be pulled out of the cavity in a linear fashion. The degradation time of the anti-adhesion layer, which is in direct contact with the cavity wall, is shorter than that of the adhesive layer. This allows surgeons sufficient time to successfully implant the cavity stent, preventing the adhesive layer from adhering to surgical instruments or the cavity wall during implantation, which could lead to difficulties or even failure. In emergency situations, such as when a patient experiences severe discomfort or requires immediate removal of the cavity stent, the anti-adhesion layer is not yet fully degraded. Only a portion of the adhesive layer is in direct contact with the cavity wall, resulting in weak adhesion between the stent and the cavity wall. Under significant tensile force, the covering tears along the tear line, causing the tubular metal framework to disintegrate. However, the stent can still be straightened into a linear shape and smoothly removed from the body through the cavity. At this point, some incompletely degraded adhesive layer may adhere to the cavity wall, but this does not affect the patient's normal physiological activities. After a period of time, these residual adhesive layers will degrade and be excreted from the body, posing no serious harm to the patient's health. In special circumstances, such as after the stent has been implanted in the cavity for a period of time, the adhesive layer has completely adhered and fixed to the cavity wall. At this point, the adhesive force between the adhesive layer and the cavity wall is sufficient to firmly fix the stent to the cavity wall. However, if it is found that the stent is misaligned, an aqueous solution at a set temperature can be introduced into the cavity for emergency removal. This causes the adhesive force between the adhesive layer (including the temperature-sensitive polymer) and the cavity wall to disappear, allowing the stent to be smoothly removed from the cavity. This stent design ensures that, under normal circumstances, the stent does not shift within the cavity and does not cause restenosis or blockage; it also allows for smooth removal in case of emergency, reducing harm to the patient. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the cavity stent provided in a specific embodiment of the present invention;

[0024] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0025] In the picture:

[0026] 1. Metal wire;

[0027] 2. Lamination; 21. Tear strip;

[0028] 3. Adhesive layer. Detailed Implementation

[0029] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] This embodiment provides a cavity stent that can be applied to cavities such as vascular cavities, urethral cavities, or esophageal cavities. During implantation, the cavity stent can be successfully inserted into the designated location within the cavity, and during its service life in the designated location, it will not shift due to cavity peristalsis, fluid flushing, changes in body position, or other reasons. Furthermore, it can be easily removed from the cavity after its service life has expired or in case of an emergency.

[0032] like Figure 1 and Figure 2 As shown, the cavity support provided in this embodiment includes a metal wire 1, a membrane 2, a tear strip 21, and an adhesive layer 3. The metal wire 1 is spirally constructed into a tubular metal skeleton with a set diameter. The membrane 2 is fixed to the outer and / or inner side of the tubular metal skeleton. The tear strip 21 is spirally wound around the membrane 2, and the tear strip 21 does not intersect with the metal wire 1. The adhesive layer 3 is disposed on the outer side of the membrane 2, and the adhesive layer 3 includes an anti-adhesive layer that is in direct contact with the wall of the cavity and an adhesive layer located between the anti-adhesive layer and the membrane 2. The anti-adhesive layer can be naturally degraded in the cavity, and the adhesive layer can be naturally degraded and / or quickly released from adhesion in the cavity, and the natural degradation time of the adhesive layer is longer than that of the anti-adhesive layer.

[0033] After reaching its expected service life, the cover 2 of the cavity stent can be torn along the tear band 21 under tensile force, allowing the tubular metal skeleton to disintegrate and be pulled out of the body in a linear form. The natural degradation time of the anti-adhesion layer in the adhesive layer 3, which is in direct contact with the cavity wall, is shorter than that of the adhesive layer. This allows the surgeon sufficient time to successfully implant the cavity stent, preventing the adhesive layer from adhering to surgical instruments or the cavity wall during implantation, which could lead to implantation difficulties or even failure. In emergency situations, such as when the patient experiences severe discomfort or other conditions requiring immediate removal of the cavity stent, the anti-adhesion layer is not yet fully degraded, and only part of the adhesive layer is in direct contact with the cavity wall. The adhesion between the cavity stent and the cavity wall is relatively weak. Under greater tensile force, the cover 2 ruptures along the tear band 21, causing the tubular metal skeleton to disintegrate. The cavity stent can still be pulled straight into a linear form and smoothly removed from the body through the cavity. At this point, some incompletely degraded adhesive layer may adhere to the wall of the cavity, but this does not affect the patient's normal physiological activities. After a period of time, these residual adhesive layers will degrade and be excreted from the body, posing no serious harm to the patient's health. This cavity stent ensures that, under normal circumstances, the stent does not shift within the cavity and does not cause restenosis or blockage; it can also be easily removed in case of emergency, minimizing harm to the patient.

[0034] This luminal stent provides the necessary support for the target cavity through a tubular metal framework. Specifically, the metal wire 1 can be one or a combination of straight and wavy shapes. The straight metal wire 1 can be spirally coiled to form the tubular metal framework, or the wavy metal wire 1 can be spirally coiled to form the tubular metal framework. The tubular metal framework formed by the wavy metal wire 1 has higher strength than that formed by the straight metal wire 1. Of course, the strength of the tubular metal framework formed by the straight metal wire 1 can also be increased by increasing its diameter. The diameter can be set according to the inner diameter of normal cavities such as blood vessels, urethra, or esophagus.

[0035] In one embodiment, the metal wire 1 is made of any one of nickel-titanium alloy, stainless steel, tantalum, or platinum-iridium alloy. Nickel-titanium alloy has good biocompatibility and shape memory (superelasticity), high temperature resistance, corrosion resistance, and long fatigue life. The metal wire 1 can be processed by weaving, laser cutting, or 3D printing during the process of spiraling and forming a tubular metal skeleton. The spiraled tubular metal skeleton can provide good support for narrow cavities.

[0036] Of course, in other embodiments, the material of the metal wire 1 can also be stainless steel, tantalum or platinum-iridium alloy, all of which can ensure that the cavity stent has a stable supporting function during its service life in the cavity.

[0037] The coating 2 is a non-degradable polymer film, which can be one or a combination of polyurethane, silicone rubber, polytetrafluoroethylene, nylon, polyester, etc., and can be processed by spraying, dip coating, hot pressing, sewing, etc., with a thickness of 0.02mm-0.5mm. This coating 2 has good biocompatibility and can effectively prevent tissue proliferation and endothelialization.

[0038] Since the membrane 2 can wrap the metal wire 1 whether it is fixed to the outside or the inside of the tubular metal skeleton, it can prevent the cavity tissue from growing into the cavity scaffold. Therefore, the membrane 2 can be fixed to the inside or the outside of the tubular metal skeleton; if cost or the wall thickness of the cavity scaffold allows, the membrane 2 can be fixed to both the inside and outside of the tubular metal skeleton.

[0039] The tubular metal skeleton has multiple spaced-apart first spirals. A spiral tear strip 21 is wound around adjacent first spirals to form multiple spaced-apart second spirals. The second spirals have a certain width. The first and second spirals are alternately arranged to form a tubular cavity support. When the tear strip 21 is subjected to tension along the axial direction, the second spirals are pulled into a linear shape, thereby causing the tubular cavity support to disintegrate, and the first spirals can also be straightened into a linear shape.

[0040] Regarding the formation of the tear strip 21, in one embodiment, after the membrane 2 is fixed to the outer and / or inner side of the tubular metal skeleton, a tubular cavity support is formed. That is, the membrane 2 covers not only the location of the first spiral ring but also the location of the second spiral ring. After the tubular metal skeleton and the membrane 2 are fixed, a complete tube wall structure is formed. The strength of the membrane 2 at the location of the second spiral ring is set to be 30% to 80% lower than the strength of the membrane 2 at the location of the first spiral ring. When a tensile force is applied to the membrane 2 at one end of the tubular cavity support, the membrane 2 at the location of the second spiral ring disintegrates from the tubular cavity support under tensile force, thereby allowing the first spiral ring to be straightened into a line. That is, the membrane 2 located between the first spiral rings directly forms the tear strip 21, and the material of the tear strip 21 is the same as the material of the membrane 2.

[0041] The strength of the coating 2 at the location of the second spiral ring is reduced by decreasing the thickness and width of the coating 2. For example, the thickness of the coating 2 at the location of the first spiral ring is set to 0.02 mm and the width is set to 4 mm; the thickness of the coating 2 at the location of the second spiral ring is set to 0.01 mm and the width is set to 0.5 mm.

[0042] Alternatively, the thickness of the coating 2 at the location of the second spiral ring can be set to be the same as the thickness of the coating 2 at the location of the first spiral ring. A spiral-shaped easy-tear line can be provided on the coating 2 at the location of the second spiral ring. The easy-tear line can be a point break line and / or a cutting depth line smaller than the thickness of the coating 2. The easy-tear line can be processed by mechanical cutting with a cutting tool, or by laser cutting or chemical etching.

[0043] In one embodiment, the tear strip 21 may also be made of a different material from the coating 2. That is, when coating 2 is applied, the coating 2 is applied only at the location of the first spiral ring, and then a material with a strength lower than that of the coating 2 is used to wrap around the first spiral ring to form the tear strip 21.

[0044] The adhesive layer 3 is partially or completely disposed on the outer side of the membrane 2. After the membrane 2 is fixed to the outer and / or inner side of the tubular metal skeleton to form a tubular cavity support, the adhesive layer 3 can be disposed on the entire outer side of the membrane 2, that is, the entire outer peripheral wall of the tubular cavity support is covered with the adhesive layer 3, increasing the bonding area between the adhesive layer 3 and the cavity wall, and ensuring the stability of the cavity support's position within the cavity. Alternatively, multiple dot-shaped or strip-shaped adhesive layers 3 can be disposed at intervals on the outer side of the membrane 2, so that the cavity support is fixed to the cavity wall at multiple intervals, which also ensures the stability of the cavity support's position within the cavity.

[0045] In one embodiment, when the adhesive layer 3 is partially disposed on the outside of the coating 2, it is distributed continuously or intermittently along the tear strip 21. Since the tear strip 21 has low strength, distributing the adhesive layer 3 continuously or intermittently along the tear strip 21 allows the tear strip 21, along with the adhesive layer 3, to be disintegrated from the tubular cavity support when tension is applied to one end of the tear strip 21, making it easier to release the adhesive force between the cavity support and the cavity wall.

[0046] Specifically, when the adhesive layer 3 is discontinuously distributed along the tear strip 21, it can be uniformly or non-uniformly distributed on the outer surface of the tear strip 21, and the distribution shape can be dotted or linear. Furthermore, the width of the adhesive layer 3 is smaller than the width of the tear strip 21 to avoid excessive adhesion between the adhesive layer 3 and the wall of the cavity, which would increase the difficulty of tearing the tear strip 21.

[0047] Of course, in other embodiments, the adhesive layer 3 may also be continuously distributed along the location of the first spiral.

[0048] Furthermore, the adhesive layer 3 includes an anti-adhesive layer and an adhesive layer disposed between the anti-adhesive layer and the coating 2. The adhesive layer can adhere to the wall of the cavity, thereby generating an adhesive force between the adhesive layer and the wall of the cavity to fix the cavity scaffold. The adhesive layer includes a bioadhesive material, wherein the bioadhesive material is a biodegradable material, and the biodegradable material includes an adhesive with reactive groups that adhere to and bind to the wall tissue of the cavity. The adhesive action of the adhesive fixes the cavity scaffold to the wall of the cavity, thereby preventing the cavity scaffold from shifting.

[0049] In one embodiment, the adhesion force is 0.1 N / cm to 5 N / cm. Experimental verification shows that an adhesion force of 0.1 N / cm to 5 N / cm is sufficient to prevent displacement of the stent within the cavity. The specific adhesion force value needs to be designed based on the fluid flow rate and velocity at the specific application location of the stent, ensuring that the stent at that location will not shift due to the flow of blood, urine, or drinking fluid passing through that location. When the stent reaches its service life, the adhesive layer will naturally degrade; in emergency situations, most of the adhesive layer will detach from the cavity wall when the tear strip 21 is subjected to tensile force, and a small amount of adhesive layer remaining on the cavity wall will completely degrade and be excreted from the body after a period of time.

[0050] In one embodiment, the adhesion of the adhesive layer to the cavity wall occurs after the anti-adhesion layer has completed its natural degradation. The adhesive layer directly contacts and adheres to the cavity wall. Setting the natural degradation time of the anti-adhesion layer to be much shorter than that of the adhesive layer allows the surgeon sufficient time to place the cavity stent in the target position within the cavity. This also helps maintain the shape of the cavity stent effectively during its shelf life (generally, cavity stents are stacked during their shelf life, and the cover 2 will be folded and compressed). After the cavity stent is in the target position within the cavity, the tubular metal skeleton compacts the cavity stent and presses it tightly against the cavity wall. The anti-adhesion layer, adhesive layer, and cover 2 are distributed from near to far from the cavity wall, meaning the anti-adhesion layer is close to the cavity wall. After the anti-adhesion layer has completed its natural degradation, the adhesive layer can directly contact and adhere to the cavity wall to fix the position of the cavity stent within the cavity and prevent displacement.

[0051] Specifically, the bioadhesive material includes any one or a combination of at least two of N-hydroxysuccinimide, N-hydroxysuccinimide ester, cyanoacrylate, aldehydes, primary amines, thiols, imidazoles, maleamides, isocyanates, epoxy compounds, acrylates, catechols, and aryl azides. For example, the combination of at least two is a combination of N-hydroxysuccinimide and N-hydroxysuccinimide ester, a combination of maleamide and acrylate, or a combination of N-hydroxysuccinimide ester and acrylate, etc.

[0052] Furthermore, the adhesive layer also includes a temperature-sensitive polymer, which can cause the adhesion between the adhesive layer and the cavity wall to disappear when an aqueous solution at a set temperature is introduced. By incorporating a temperature-sensitive polymer into the adhesive layer, when it is necessary to urgently release the adhesion of the adhesive layer, an aqueous solution at a set temperature can be introduced into the cavity, causing the adhesion between the adhesive layer and the cavity wall to disappear. This makes it easier to disintegrate the tubular cavity support when a tensile force is applied to one end of the tear strip 21, thereby straightening the tubular metal skeleton into a linear shape and removing it from the cavity.

[0053] Regarding thermosensitive polymers, when the temperature is below the thermosensitive polymer transition temperature (LCST), the hydrophilic groups within the polymer molecule dominate. These hydrophilic groups form hydrogen bonds with water molecules, creating a dense hydration shell structure, causing the thermosensitive polymer to exhibit an extended "coil" state. At this point, the thermosensitive polymer is soluble. Thermosensitive polymers exhibit a cloud point (CP) or a lower critical dissolution temperature (LCST) in aqueous solutions. Water-soluble thermosensitive polymers are selected to produce low-viscosity liquids when dissolved in water at low temperatures. Raising the temperature above the gelation temperature (Tgel) will cause the composition to solidify. The thermosensitive polymer has an ABA triblock structure, where A is a hydrophilic oligomer and B is a hydrophobic oligomer; or A is a hydrophobic oligomer and B is a hydrophilic oligomer; or A and B contain aliphatic polyethers and / or polyester units; or A is poly(ethylene oxide) and B is poly(propylene oxide). This thermosensitive polymer is poly(N-substituted (meth)acrylamide). This poly(N-substituted (meth)acrylamide) is poly(N-isopropyl (meth)acrylamide). The thermosensitive polymer is hydroxypropyl methylcellulose, ethyl hydroxyethyl cellulose (EHEC), or any combination thereof. The thermosensitive polymer has a multi-block (ABA-X)m random or repeating configuration, where m is an integer from 1 to 30, and X is a chain extender. X is selected from di, tri, and polyisocyanates, di, tri, and polycarboxylic acids, diacyl halides, triphosgene, or any combination thereof. A is a hydrophilic oligomer, and B is a hydrophobic oligomer; or, A is a hydrophobic oligomer, and B is a hydrophilic oligomer. The multi-block structure is polyurethane, polycarbonate, polyester, or any combination thereof, and the transformation can occur at temperatures as low as 30°C-40°C. Poly(N-isopropylacrylamide) [poly(NIPAM)] exhibits a low critical dissolution temperature (LCST) of about 31°C in aqueous solution. NIPAM gels undergo a volumetric phase transition from a swollen gel to a shrinking gel in water at approximately 33.6°C. First, the thermosensitive copolymer synthesized from the hydrophilic monomer and the thermosensitive polymer monomer exhibits shrinkage responsive to temperature (human body temperature 36.5°C). Increasing the amount of hydrophilic monomer raises the transition temperature of the resulting thermosensitive copolymer. Therefore, for thermosensitive polymer monomers with inherently high transition temperatures (such as N-isopropylacrylamide), the amount of hydrophilic monomer should not be excessive. Conversely, for thermosensitive polymer monomers with inherently low transition temperatures (such as 2-methyl-2-acrylate-2-(2-methoxyethoxy)ethyl ester), increasing the amount of hydrophilic polymer monomer can raise the transition temperature of the resulting polymer.

[0054] It should be noted that the set temperature is not specifically limited in this embodiment; those skilled in the art can set it according to the transition temperature of the temperature-sensitive polymer. The aqueous solution can be physiological saline or purified water.

[0055] The anti-adhesion layer prevents adhesion to the cavity wall, allowing the stent to move within the cavity to its target location. The anti-adhesion layer delays the release of the adhesive layer, providing the physician with time to maneuver and preventing the stent from adhering to the cavity wall before the implantation procedure is complete. Alternatively, when the stent is within its shelf life, folding and compressing it prevents the adhesive layer from self-adheding and causing stent failure. During implantation, the anti-adhesion layer also ensures the stent can move within the cavity, allowing the physician to place it at the target location.

[0056] Specifically, the surface of the anti-adhesive layer can be a smooth surface or an uneven surface with a certain degree of friction, as long as it does not affect the relative movement of the cavity support relative to the cavity wall. The anti-adhesive layer includes biodegradable materials, which can be selected from: PLGA (poly(lactic-co-glycolic acid), hyaluronic acid, deacetylated chitosan, quaternized chitosan, carboxymethyl chitosan, type I collagen, carboxymethyl chitosan, regenerated oxidized cellulose, oxidized cellulose, dextran, starch, collagen, and gelatin. The anti-adhesive layer can be selected from one or more of the above-mentioned biodegradable materials.

[0057] The anti-adhesion layer and adhesive layer do not undergo natural degradation in a dry state; they only degrade naturally in a moist environment within the cavity. Therefore, the anti-adhesion layer and adhesive layer do not undergo natural degradation during their shelf life, and their natural degradation time is calculated from the time of implantation into the cavity. Generally, the anti-adhesion layer will naturally degrade within a set time after being implanted at the target position within the cavity. Within this set time, the doctor can adjust the position of the cavity stent within the cavity. If the patient experiences unbearable discomfort or other situations require emergency removal, the anti-adhesion layer has not yet completely degraded, and only part of the adhesive layer is in direct contact with the cavity wall. The adhesion between the cavity stent and the cavity wall is relatively weak. Therefore, only surgical forceps or other tools are needed to apply a large pulling force to one end of the cavity stent's tear strip 21. Under the action of the pulling force, the tear strip 21 disintegrates from the tubular cavity stent support, allowing the tubular metal skeleton to straighten into a line and be smoothly moved out of the body along the cavity.

[0058] Specifically, the natural degradation time of the anti-adhesion layer is 1 hour to 3 days, and the natural degradation time of the adhesive layer is 3 days to 1 year. This means that the anti-adhesion layer will only completely degrade naturally within 1 hour to 3 days after the stent is implanted at the target location in the cavity, allowing the doctor time for the implantation procedure and time for emergency removal should the patient experience discomfort. If the patient experiences no discomfort, they can engage in appropriate activities and consume small amounts of food after 3 days to prevent the stent from shifting within the cavity. As the anti-adhesion layer completely degrades, the adhesive layer adheres firmly to the cavity wall, allowing the patient to move freely and gradually increase their food intake without stent displacement. If, after the adhesive layer has adhered firmly to the cavity wall, the patient experiences discomfort or the stent is found to be misaligned, or other situations necessitate removal, an aqueous solution at a set temperature can be introduced into the cavity. The aqueous solution reacts with the temperature-sensitive polymer in the adhesive layer, causing the adhesion between the adhesive layer and the cavity wall to disappear. Then, a pulling force is applied to one end of the stent, straightening the tubular metal skeleton into a linear shape and removing it along the cavity.

[0059] Furthermore, the natural degradation time of the anti-stick layer can be controlled by adjusting the molecular weight, layer thickness, material type, or combination ratio, thereby meeting the service time requirements of different cavities.

[0060] In this embodiment, the cavity stent is implanted into the target cavity by a physician using a delivery system. The supporting force of the tubular metal skeleton compresses the entire tubular cavity stent support body tightly against the cavity wall. Then, the anti-adhesion layer begins to degrade and is completely degraded within 1 hour to 3 days. Subsequently, the adhesive layer is exposed and adheres to the cavity tissue. This adhesion can fix the cavity stent and prevent its displacement. After the cavity stent reaches its expected service life, the adhesive layer degrades to very low viscosity or disappears completely. At this time, there is no adhesive connection between the cavity stent and the cavity wall. Using surgical forceps or other tools, a pulling force is applied to one end of the cavity stent, and the membrane 2 of the cavity stent can be torn along the tear band 21, causing the tubular cavity stent support body to disintegrate. After disintegration, the tubular metal skeleton is straightened into a line and smoothly moved out of the body along the cavity. In emergency situations, such as when a patient experiences severe discomfort or requires immediate removal of the intracavitary stent, the anti-adhesion layer is not yet fully degraded. Only a portion of the adhesive layer is in direct contact with the cavity wall, resulting in weak adhesion between the stent and the cavity wall. Using surgical forceps or similar tools, a slightly greater pulling force is applied to one end of the stent. Under this force, the stent's covering membrane 2 is torn along the tear band 21, causing the tubular stent support to disintegrate. The tubular metal skeleton can still be straightened and smoothly removed from the body through the cavity. A small amount of incompletely degraded adhesive layer may remain on the cavity wall, but this does not affect the patient's normal physiological activities. After a period of time, this residual adhesive layer will completely degrade and be excreted. The anti-adhesion layer outside the adhesive layer can shield the adhesive layer's stickiness for a certain period, allowing the surgeon sufficient time to successfully implant the stent into the patient. This avoids implantation difficulties or even failure caused by the adhesive layer adhering to surgical instruments or other parts of the cavity wall during stent implantation. This anti-adhesion layer also helps maintain the shape of the cavity stent during its shelf life (generally, the cavity stent is in a stacked state during its shelf life, and the film 2 will be folded and squeezed), preventing the cavity stent from failing due to self-adhesion between the adhesive layers.

[0061] In special circumstances, such as after a stent has been implanted in a cavity for a period of time, the adhesive layer has completely adhered and fixed to the cavity wall. At this time, the adhesive force between the adhesive layer and the cavity wall is sufficient to firmly fix the stent to the cavity wall. However, if it is found that the stent is adhered to the cavity wall in the wrong position, in order to remove the stent urgently, saline or purified water at a temperature lower than the set temperature of the thermosensitive polymer transition (LCST) can be introduced into the cavity to change the thermosensitive polymer from solid to liquid, thereby removing the stent from the cavity.

[0062] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. A cavity stent, characterized in that, include: Metal wire (1), said metal wire (1) is spirally constructed as a tubular metal skeleton with a set diameter; A film (2) is fixed to the outside and / or inside of the tubular metal skeleton; A tear strip (21) is spirally wound around the film (2), and the tear strip (21) does not intersect with the metal wire (1); An adhesive layer (3) is disposed on the outside of the covering film (2). The adhesive layer (3) includes an anti-adhesive layer that is in direct contact with the wall of the cavity and an adhesive layer located between the anti-adhesive layer and the covering film (2). The anti-adhesive layer is capable of natural degradation within the cavity, the adhesive layer is capable of natural degradation and / or emergency release within the cavity, and the natural degradation time of the adhesive layer is longer than that of the anti-adhesive layer.

2. The cavity stent according to claim 1, characterized in that, The anti-adhesive layer does not adhere to the wall of the cavity, so that the cavity support can move to the target position within the cavity.

3. The cavity stent according to claim 1, characterized in that, The adhesive layer can adhere to the wall of the cavity, thereby creating an adhesive force between the adhesive layer and the wall of the cavity to fix the cavity support.

4. The cavity stent according to claim 3, characterized in that, The adhesion force is 0.1 N / cm to 5 N / cm.

5. The cavity stent according to claim 1, characterized in that, The adhesive layer (3) is disposed partially or entirely on the outside of the coating (2).

6. The cavity stent according to claim 5, characterized in that, When the adhesive layer (3) is partially disposed on the outside of the coating (2), it is distributed continuously or intermittently along the tear strip (21).

7. The cavity stent according to any one of claims 1-6, characterized in that, The adhesive layer includes a temperature-sensitive polymer that can cause the adhesion between the adhesive layer and the wall of the cavity to disappear when an aqueous solution at a set temperature is introduced.

8. The cavity stent according to any one of claims 1-6, characterized in that, The natural degradation time of the anti-stick layer is 1 hour to 3 days, and the natural degradation time of the adhesive layer is 3 days to 1 year.

9. The cavity stent according to any one of claims 1-6, characterized in that, The metal wire (1) is made of any one of nickel-titanium alloy, stainless steel, tantalum or platinum-iridium alloy.

10. The cavity stent according to any one of claims 1-6, characterized in that, The metal wire (1) is one or a combination of straight and wavy shapes.

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