Airway stent

Abstract

The present application relates to an airway stent comprising a stent body and a covering membrane disposed on the stent body. The covering membrane comprises a covering section and folded-back sections, the covering section covering the stent body, and the folded-back sections being formed by folding back from ends of the covering section. The airway stent provided by the present application forms folded-back sections at both ends of the airway stent by using the covering membrane to increase thickness at both ends of the airway stent, while also enhancing soft support at both ends of the airway stent, thereby providing radial support to end portions at both ends of the airway stent without introducing rigid stimuli. This configuration reduces rigid friction of the ends of the stent body against a tracheal wall, thereby reducing stimuli to tracheal wall tissue and lowering the likelihood of airway restenosis.

Description

Airway stents Technical Field

[0001] The present application belongs to the field of medical device technology, and specifically relates to an airway stent. Background Art

[0002] To prevent airway stenosis caused by tumor growth and improve patients' survival, metal stents made of stainless steel or nickel-titanium alloy are widely used clinically. By inserting a metal stent into the narrowed area of ​​the trachea, the stent's supportive properties dilate the narrowed area, rapidly reestablishing the airway, increasing the patient's breathing capacity, and alleviating symptoms such as dyspnea, thereby improving the patient's quality of life.

[0003] During the implantation process, the metal mesh at both ends of the stent contacts the tracheal wall, causing friction and irritation to the tracheal wall tissue. Over time, this can lead to infection, and granulation tissue can slowly grow along both ends of the tracheal stent, causing the patient's airway to narrow again, resulting in breathing difficulties and, in severe cases, airway obstruction.

[0004] Contents of this application

[0005] A technical problem solved by the present application is how to provide a method for reducing the stimulation of hard objects on the airway wall at both ends of the airway stent, so as to reduce the possibility of airway restenosis.

[0006] The present application provides an airway stent, which includes a stent body and a coating provided on the stent body, wherein the coating includes a covering portion and a folding portion, wherein the covering portion covers the stent body, and the folding portion is formed by folding back from the end of the covering portion.

[0007] In one embodiment, the coating is wrapped around the stent body, and the material of the coating is medical silicone or polyurethane.

[0008] In one embodiment, the stent body includes a middle section and thinned sections connected to both ends of the middle section, and the wire diameter of the thinned sections is smaller than the wire diameter of the middle section.

[0009] In one embodiment, the stent body further includes a proximal end and a distal end, and the proximal end and / or the distal end are provided with a recovery line wound along the circumference thereof; the number of unit spans formed by the recovery line along the circumference of the stent body is not greater than 15.

[0010] In one embodiment, the folding portion is folded from the end of the covering portion toward the outside of the airway stent, and the folding portion includes a connecting end and a free end, the connecting end is connected to the end of the covering portion, and the free end can be sutured to the stent body by means of sutures.

[0011] In one embodiment, the end of the coating extends beyond the end of the stent body, so that the portion of the coating that extends beyond the end forms a buffer zone.

[0012] In one embodiment, the folded portion includes an inner side surface and an outer side surface, the inner side surface is a side close to the covering portion, the outer side surface is a side away from the covering portion, and the outer side surface is provided with at least one protrusion.

[0013] In one embodiment, at least two protrusions are arranged at intervals along the axial direction, and the heights of the two protrusions gradually decrease in the axial direction from the end portion of the airway stent toward the middle portion of the airway stent.

[0014] In one embodiment, a surface of the covering portion located on the inner side of the airway stent is provided with a hydrophobic coating.

[0015] In one embodiment, the airway stent further includes a drug-releasing interlayer, which includes a drug layer, a filter layer and an injection needle nozzle. The drug layer is arranged on the outside of the stent body, the filter layer is arranged on the side of the drug layer away from the stent body, and the injection needle nozzle is arranged on the filter layer. The drug-releasing interlayer and the stent body are wrapped in the coating, and the opening of the injection needle nozzle is exposed from the coating.

[0016] In one embodiment, the injection needle nozzle is funnel-shaped, and includes a base and a degradable head. One end of the base is welded to the filter layer, and the other end extends radially along the airway stent and exceeds the filter layer. The side of the degradable head away from the base is exposed to the coating.

[0017] In one embodiment, the drug layer is a soft colloid at room temperature or below, and melts into a liquid at a temperature above room temperature, so that when the film of the airway stent is radially squeezed, the liquid drug can flow out from the injection needle nozzle.

[0018] A technical effect of an embodiment of the present application is: by using a coating to form folded parts at both ends of the airway stent to increase the thickness of the two ends of the airway stent, and at the same time increase the soft support at both ends of the airway stent to provide radial support to the end parts of both ends of the airway stent, while not increasing the stimulation of hard objects, reducing the friction of hard objects on the tracheal wall by the end of the stent body, thereby reducing the stimulation to the tracheal wall tissue and reducing the possibility of airway restenosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of an airway stent provided in the present application;

[0020] FIG2a is a partial cross-sectional schematic diagram of one end of the airway stent provided by the present application when the folding portion is not folded;

[0021] FIG2 b is a partial cross-sectional view along the AA direction of FIG1 (a schematic diagram showing the folded portion of FIG2 a folded outside the airway stent);

[0022] FIG3 is a schematic structural diagram of another airway stent provided in the present application;

[0023] FIG4a is a partial cross-sectional schematic diagram of one end of another airway stent provided by the present application when the folding portion is not folded;

[0024] FIG4 b is a partial cross-sectional view of another embodiment along the AA direction of FIG1 (a schematic diagram of the folded portion of FIG4 a folded outside the airway stent);

[0025] FIG5 is a schematic structural diagram of another airway stent provided in the present application (corresponding to FIG4b );

[0026] FIG6 is a cross-sectional view along the BB direction in FIG3;

[0027] FIG7 is a cross-sectional view of another airway stent taken along the CC direction in FIG5 ;

[0028] FIG8 is a cross-sectional view of the silicone coating deforming and concaving toward the inner side of the airway stent relative to the needle nozzle when the airway stent is squeezed from the perspective of FIG6 ;

[0029] FIG9 is a cross-sectional view of the silicone coating deforming and concaving toward the inner side of the airway stent relative to the needle nozzle when the airway stent is squeezed from the perspective of FIG7 ;

[0030] FIG10 is an enlarged view of point D in FIG7 ;

[0031] FIG11 is a schematic diagram of the base of the injection needle nozzle after the degradable head in FIG10 is degraded;

[0032] FIG12 is a schematic structural diagram of the support system provided in this application.

[0033] 100. Airway stent; 10. Stent body; 10a. Proximal end; 10b. Distal end; 11. Intermediate segment; 12. Thinned segment; 20. Cover; 21. Covering portion; 211. Single membrane segment; 22. Folding portion; 221. Connecting end; 222. Free end; 223. Medial side; 224. Lateral side; 2241. Protrusion; 20a. Buffer zone; 30. Retrieval line; 40. Suture; 50. Hydrophobic coating;

[0034] 60. Drug-release interlayer; 61. Drug layer; 62. Filter layer; 63. Injection needle nozzle; 631. Opening; 632. Base; 633. Degradable head;

[0035] 70. Delivery device; 71. Seeker; 72. Sheath core; 73. Sheath tube;

[0036] 170. Bracket system. DETAILED DESCRIPTION

[0037] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0039] For ease of description, the following description uses the terms "distal" and "proximal." The "distal" refers to the end of the airway stent away from the mouth after implantation, and the "proximal" refers to the end of the airway stent closer to the mouth after implantation. "Axial" in this patent should be understood to refer to the direction in which the airway stent is advanced and advanced, i.e., the axial direction of the tubular shape. The direction perpendicular to the "axial" is defined as the "radial" direction.

[0040] The present application provides an airway stent 100, comprising a stent body 10 and a coating 20 disposed on the stent body 10. The stent body 10 comprises a dense mesh structure formed by braiding or laser cutting a braided wire. In this embodiment, as shown in FIG1 , the stent body 10 comprises a mesh structure of a diamond-shaped grid formed by overlapping one or more braided wires. This mesh structure ensures axial elongation, allowing the airway stent 100 to maintain axial support while also exhibiting axial elongation. When the airway stent 100 needs to be recovered, the airway stent 100 can be axially stretched by pulling a recovery line 30 to tighten one end of the airway stent 100, thereby reducing its radial dimension and allowing the airway stent 100 to be recovered. The diameter of the braided wires can be selected from a range of 0.14 mm to 0.4 mm, and the braided wires can be made of a shape-memory alloy, such as nickel-titanium wire.

[0041] The stent body 10 also includes a middle section 11 and thinning sections 12 connected to both ends of the middle section 11, wherein the wire diameter of the thinning section 12 is smaller than the wire diameter of the middle section 11, and the wire diameter of the thinning section 12 gradually decreases in the axial direction from the middle section 11 of the airway stent 100 toward the end away from the middle section 11, that is, the radial supporting force of the thinning section 12 gradually decreases from the side close to the middle section 11 toward the end away from the middle section 11. In this embodiment, the middle section 11 and the thinned section 12 can be configured as an integrated structure with the same mesh density. By performing a thinning process on the area near the two ports of the stent body 10, the wire diameter of the nickel-titanium wire near the two ends of the stent body 10 is reduced to form two thinned sections 12, thereby making the radial support force of the thinned sections 12 less than the radial support force of the middle section 11. The nickel-titanium wire of the thinned sections 12 becomes softer due to the reduced diameter, thereby alleviating the friction between the two ends of the stent and the tracheal wall, thereby reducing the irritation of the two ends of the airway stent 100 to the tracheal wall and reducing the possibility of granulation proliferation at the contact area between the edges of the two ports of the stent and the tracheal wall. Among them, the thinned section 12 at one end can occupy a range of 0-30% of the axial length of the stent body 10. In this embodiment, the thinned section 12 at one end occupies 7% of the axial length of the stent body 10, which can maintain most of the radial support force of the airway stent 100 body while softening the two ends of the airway stent 100 to reduce the irritation of the airway stent 100 end to the airway wall.

[0042] The stent body 10 includes a proximal end 10a and a distal end 10b. At least one of the proximal end 10a and the distal end 10b is provided with a recovery line 30 wound along its circumference. In this embodiment, the recovery line 30 passes through the inner and outer sides of the end tip of the stent body 10 along the circumferential direction, and passes through the coating 20 at the same time. After winding once, at least one annular knot is formed to facilitate tightening the annular knot with a biopsy forceps to pull the recovery line 30 outward, thereby removing the airway stent 100 for recovery.

[0043] The recovery line 30 passes through the diamond grid of the bracket body 10 at intervals across the mesh along the circumferential direction, so that the recovery line 30 includes multiple inner line segments (inside the bracket body) and multiple outer line segments (outside the bracket body) along the inside and outside of the bracket body 10. An inner line segment and an outer line segment connected to the inner line segment are defined as the unit span of the recovery line 30. The number of unit spans formed by the recovery line 30 along the circumference of the bracket body 10 is not more than 15, so that the unit span is not too small. If the unit span of the recovery line 30 is too small, the unit spans along the circumferential direction will be too dense, which will increase the friction between the recovery line and the bracket body, thereby causing the pulling resistance of the recovery line to be too large and not conducive to recovery.

[0044] The coating 20 includes a covering portion 21 and a folding portion 22. The covering portion 21 covers the stent body 10, and the folding portion 22 is formed by folding back from the end of the covering portion 21. It can be understood that the folding portion 22 increases the thickness at both ends of the airway, while increasing the soft support at the end of the airway stent 100 to provide radial support force to the end parts of both ends of the airway stent, while not increasing the stimulation of hard objects, reducing the friction of hard objects on the tracheal wall by the end of the stent body 10, thereby reducing the stimulation to the tracheal wall tissue and reducing the possibility of airway restenosis.

[0045] The edge of the covering film 20 exceeds the edge of the stent body 10, and the portion of the covering film 20 that exceeds the stent body 10 at both ends is the buffer zone 20a. In this embodiment, both the covering portion 21 and the folding portion 22 have a section located in the extension direction of the stent body 10 and do not cover the stent body 10. The overlapping portion forms the above-mentioned buffer zone 20a. In this embodiment, as shown in Figure 1 and Figure 2b, the end of the covering portion 21 exceeds the end of the stent body 10, and the portion of the covering portion 21 that exceeds the stent body 10 and does not cover the stent body 10 is called a single film segment 211; as shown in Figures 2a-2b, the folding portion 22 is folded from the end of the covering portion 21 toward the outside of the airway stent 100, wherein the portion of the folding portion 22 that overlaps with the above-mentioned single film segment 211 and the single film segment 211 together form the above-mentioned buffer zone 20a, which is used to buffer the contact between the tip of the stent body 10 and the tracheal wall, reduce the friction of the end of the stent body 10 on the hard objects of the tracheal wall, and thus reduce the irritation to the tracheal wall tissue. The length of the buffer zone 20a in the axial direction ranges from 1 mm to 3 mm; the length of the stent body 10 of the airway stent 100 in the axial direction ranges from 20 mm to 120 mm;

[0046] The folded portion 22 includes a connecting end 221 and a free end 222. The connecting end 221 is connected to the end of the single membrane segment 211. The free end 222 can be sutured to the airway stent 100 by forming a cuffing suture 40. As shown in FIG1 and FIG2b, the cuffing suture 40 circumferentially sutures the free end 222, thereby fixing the free end 222 to the stent body 10. The folded portion 22 can be a continuous membrane or a circumferentially spaced membrane strip. When the spaced membrane strips are folded, as shown in FIG3, the folded portion 22 is positioned at a point on the end edge of the stent body 10 (i.e., at the corner of the diamond grid) to reduce the irritation of the stent body 10 on the airway wall caused by hard objects. In other embodiments, the folded portion 22 can be a membrane strip with an interval at one end, as shown in the proximal end of the airway stent 100 in Figure 3, and a circumferentially continuous membrane at the other end, as shown in the distal end of the airway stent 100 in Figure 3; it can also be a membrane strip with intervals at both ends, or a circumferentially continuous membrane at both ends, which is not limited here.

[0047] The coating 20 is wrapped around the stent body 10. The material of the coating 20 can be a polymer film such as medical silicone or polyurethane, and the coating 20 is in a colloidal form when covered on the stent body 10, so that the coating 20 is also ductile and elastic in the axial direction. It is understandable that the coating 20 can be wrapped around the stent body 10 by soaking it in a solution so that the stent body 10 is not exposed to the outside, or it can be covered on the stent body 10 by other means. The way in which the coating 20 is covered on the stent body 10 is not limited. In other embodiments, the inner side 223 of the coating 20 can be formed into a smooth surface to reduce the possibility of sputum plug retention, and the outer side 224 of the coating 20 can be formed into a concave and convex surface to increase the anchoring of the airway stent 100 to the tracheal wall. It is understandable that a hydrophobic coating 50 can also be provided on the surface of the covering portion 21 located on the inner side of the airway stent 100, as shown in Figure 7, which can further reduce the retention and adhesion of sputum plugs, thereby reducing the risk of tracheal restenosis caused by sputum plug retention.

[0048] In this embodiment, as shown in Figures 4a-4b in combination with Figure 5, the folding portion 22 includes an inner side surface 223 and an outer side surface 224, the inner side surface 223 is the side close to the covering portion 21, and the outer side surface 224 is the side away from the covering portion 21. As shown in Figure 4b, the outer side surface 224 is provided with at least one protrusion 2241. The setting of the protrusion 2241 can increase the friction between the end of the airway stent 100 and the tracheal wall, thereby avoiding displacement of the airway stent 100, and at the same time can further compensate for the problem of reduced radial support force of this part due to the thinning of the thinning segment 12. At least two protrusions 2241 are arranged at intervals along the axial direction, and the heights of the two protrusions 2241 gradually decrease in the axial direction from the end of the airway stent 100 toward the middle part of the airway stent. In this embodiment, three protrusions 2241 are arranged at intervals along the axial direction, and the heights of the three protrusions 2241 gradually decrease in the direction from the end of the airway stent 100 toward the middle section 11 of the airway stent 100, so as to complement the change in wire diameter of the thinning section 12, and can further compensate for the radial support force of the stent body 10 reduced due to the thinning section 12.

[0049] In this embodiment, as shown in FIG3 , a developing member 70 is further provided at the proximal end, distal end and axial middle position of the stent body 10. The three developing members 70 can be configured as developing wires wound around the braided wire of the stent body 10 to display the distal end, proximal end and middle position of the airway stent 100. The three developing members are on the same axial line, or are not offset much in the axial direction (the circumferential offset central angle does not exceed 10°), and three other developing members symmetrical to the three developing members are also provided at the proximal end, distal end and middle on the opposite side (not shown in the figure), which is beneficial to the positioning and visualization of the stent implantation.

[0050] In this embodiment, as shown in Figures 6-11, the airway stent 100 also includes a drug-releasing interlayer 60. The drug-releasing interlayer 60 includes a drug layer 61, a filter layer 62 and an injection needle nozzle 63. The drug layer 61 is arranged on the outside of the stent body 10, the filter layer 62 is arranged on the side of the drug layer 61 away from the stent body 10, and the injection needle nozzle 63 is arranged on the filter layer 62. When the airway stent 100 naturally expands in the airway and sticks to the airway wall, the tip of the injection needle nozzle 63 pierces the airway wall to facilitate drug injection; the drug-releasing interlayer 60 and the stent body 10 are wrapped in the coating 20 together, and the opening 631 of the injection needle nozzle 63 is exposed from the coating 20, as shown in Figure 6.

[0051] As shown in FIG6 in conjunction with 10-11, the injection nozzle 63 is funnel-shaped and includes a base 632 and a degradable head 633. The base 632 is the large end of the funnel, while the degradable head 633 is the small end of the funnel. One end of the base 632 is fused to the filter layer 62, while the other end extends radially along the airway stent 100 and beyond the filter layer 62. The side of the degradable head 633 facing away from the base 632 (the opening at the small end) is exposed to the membrane 20, as shown in FIG7. The drug layer 61 is a soft colloid at room temperature or below (25°C). It melts into a liquid at temperatures above room temperature. When the membrane 20 of the airway stent 100 is subjected to radial compression, the silicone membrane 20 deforms, allowing the liquid drug to flow out of the injection nozzle 63, as shown in FIG9. This reduces tumor tissue proliferation or the growth of tracheal smooth muscle tissue, reduces granulation, and thus reduces the possibility of airway restenosis.

[0052] The main component of the drug layer 61 is a sirolimus aqueous solution. Other components include hydroxyphenyl esters (such as methyl ester and propyl hydroxyphenyl ester) and gelatin. The main function of sirolimus is to inhibit the proliferation of tumor cells and reduce the growth of granulation tissue. Gelatin and glycerol are used as carriers, so that the drug begins to melt when the temperature exceeds room temperature (25°C). The function of hydroxyphenyl ester is to inhibit bacteria and prevent bacterial growth in the drug solution after long-term implantation of the stent. Among them, the concentration of the sirolimus aqueous solution can be selected as 1 mg / ml; gelatin can be pharmaceutical grade gelatin with a concentration of >98%; glycerol can be medical grade glycerol with a concentration of >98%; hydroxyphenyl ester can be selected from a sample with a concentration of >98%, and the above ingredients are mixed in a ratio of sirolimus: gelatin: glycerol: hydroxyphenyl ester = 10 (±1): 20 (±2): 67 (±2): 3 (±1) by mass to form the above drug layer. When the temperature exceeds 30°C, the drug layer 61 is completely dissolved into a liquid.

[0053] As shown in Figures 9-10, the filter layer 62 is positioned on the side of the drug layer 61 facing away from the stent body 10. The filter layer 62 can be made of a high-toughness meltblown fabric. Two layers of meltblown fabric can be used. A portion of the base 632 of the injection nozzle 63 is then welded between the two layers of meltblown fabric, forming a single, integrated unit. The end of the base 632 near the degradable head 633 is not exposed from the coating. The base 632 can be partially made of polyester, while the degradable head 633 can be made of poly(L-lactic acid), which is biodegradable and has a degradation cycle of approximately two months. After the degradable head degrades, the base's structure relative to the meltblown fabric is shown in Figure 11. The base 632 is welded between the two layers of meltblown fabric, and the side of the base 632 near the degradable head 633 has a smoothly curved shape. This, in addition to the insulation provided by the coating, further reduces irritation to the airway wall.

[0054] When the airway stent 100 is released into the airway, the airway stent 100 is squeezed by the tracheal wall, thereby squeezing the silicone membrane, so that the drug layer 61 melted into liquid is injected into the tissue of the tracheal wall through the injection needle nozzle 63, thereby inhibiting the growth of tumors or granulation cells and reducing the risk of airway restenosis.

[0055] The present application also provides a stent system 170, as shown in Figure 12, including the above-mentioned airway stent 100 and a delivery device 70. The delivery device 70 includes a sheath core 72, a guide head 71 and a sheath tube 73. The sheath tube 73 surrounds the sheath core 72 and forms a loading space for the airway stent 100 at its end away from the operator. The airway stent 100 surrounds the sheath core 72 in the loading space and is close to the guide head 71, and is radially constrained in the sheath tube 73. When the airway stent 100 is delivered to the airway using the delivery device 70, the airway stent 100 can be released by withdrawing the sheath tube 73 so that the airway stent 100 naturally expands and adheres to the airway wall.

[0056] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An airway stent, characterized in that, The airway stent includes a stent body and a film disposed on the stent body. The film includes a covering portion and a folded portion. The covering portion covers the stent body, and the folded portion is formed by folding back from the end of the covering portion.

2. The airway stent according to claim 1, characterized in that, The film is wrapped around the stent body, and the material of the film is medical silicone or polyurethane.

3. The airway stent according to claim 1, characterized in that, The stent body includes an intermediate section and tapered sections connected to both ends of the intermediate section. The wire diameter of the tapered sections is smaller than that of the intermediate section.

4. The airway stent according to claim 1, wherein The stent body further includes a proximal end and a distal end. A retrieval line wound circumferentially is provided at the proximal end and / or the distal end; the number of unit spans formed by the retrieval line in one circumferential turn along the stent body is not greater than 15.

5. The airway stent according to claim 1, wherein The folded portion is folded outward from the end of the covering portion toward the outside of the airway stent. The folded portion includes a connecting end and a free end. The connecting end connects to the end of the film portion, and the free end can be sutured to the stent body by means of a suture.

6. The airway stent according to claim 1, wherein The end of the film extends beyond the end of the stent body, such that the extended portion of the film forms a buffer zone.

7. The airway stent according to claim 1 or 5, characterized in that, The folded portion includes an inner side and an outer side. The inner side is the side close to the covering portion, and the outer side is the side away from the covering portion. At least one protrusion is provided on the outer side.

8. The airway stent according to claim 7, wherein At least two protrusions are arranged at intervals along the axial direction. The heights of the two protrusions gradually decrease in the axial direction from the end of the airway stent toward the middle part of the airway stent.

9. The airway stent according to claim 1, wherein A hydrophobic coating is provided on the surface of the covering portion located inside the airway stent.

10. The airway stent according to claim 1, characterized in that, The airway stent further includes a drug sustained-release interlayer. The drug sustained-release interlayer includes a drug layer, a filter layer, and an injection nozzle. The drug layer is disposed on the outside of the stent body. The filter layer is disposed on the side of the drug layer away from the stent body. The injection nozzle is disposed on the filter layer. The drug sustained-release interlayer and the stent body are together wrapped in the film, and the opening of the injection nozzle is exposed outside the film.

11. The airway stent according to claim 10, characterized in that, The injection nozzle is funnel-shaped. The injection nozzle includes a base and a degradable head. One end of the base is welded to the filter layer, and the other end extends radially along the airway stent and extends beyond the filter layer. The side of the degradable head away from the base is exposed outside the film.

12. The airway stent according to claim 10, characterized in that, The drug layer is a soft colloid at normal temperature and below normal temperature, and melts into a liquid state above normal temperature, such that when the film of the airway stent is radially compressed, the liquid drug can flow out from the injection nozzle.

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