Airway stent

Abstract

The utility model relates to an airway stent, the airway stent comprises a stent body and a covering film arranged on the stent body, the covering film comprises a covering part and a folding part, the covering part covers the stent body, and the folding part is formed by folding back from the end part of the covering part. According to the airway stent, the folding parts are formed at the two ends of the airway stent through the covering films so as to increase the thickness of the two ends of the airway stent, meanwhile, the soft supports at the two ends of the airway stent are added so as to provide radial support for the end portions of the two ends of the airway stent, and meanwhile stimulation of hard objects cannot be increased; and hard object friction of the end part of the stent body to the tracheal wall is reduced, so that stimulation to tracheal wall tissues is reduced, and the possibility of restenosis of the airway is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical equipment, and in particular relates to an airway stent. Background Art

[0002] In order to prevent airway stenosis caused by tumor growth and improve the patient's survival status, metal stents made of stainless steel or nickel-titanium alloy are widely used in clinical practice. By inserting a metal stent into the stenosis of the trachea and using the support of the metal stent to expand the stenosis of the trachea, the airway can be quickly rebuilt, the patient's breathing volume can be increased, and symptoms such as dyspnea can be alleviated, 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 and generates friction, which stimulates 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. Utility Model Content

[0004] A technical problem solved by the utility model 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 restenosis of the airway.

[0005] The utility model provides an airway stent, which comprises a stent body and a coating arranged on the stent body, wherein the coating comprises 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.

[0006] In one embodiment, the coating is wrapped around the stent body, and the coating is made of medical silicone or polyurethane.

[0007] In one embodiment, the stent body includes a middle section and thinned sections connected to two ends of the middle section, and the wire diameter of the thinned section is smaller than the wire diameter of the middle section.

[0008] 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 one circle of the circumference of the stent body is not greater than 15.

[0009] 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 coating portion, and the free end can be sutured to the stent body by means of sutures.

[0010] In one embodiment, the end of the coating exceeds the end of the stent body, so that the protruding portion of the coating forms a buffer zone.

[0011] In one embodiment, the folded portion includes an inner side and an outer side, the inner side is a side close to the covering portion, the outer side is a side away from the covering portion, and the outer side is provided with at least one protrusion.

[0012] In one of the embodiments, 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 of the airway stent toward the middle part of the airway stent.

[0013] In one embodiment, a hydrophobic coating is provided on a surface of the covering portion located on the inner side of the airway stent.

[0014] In one embodiment, the airway stent further includes a drug-sustained release 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, the injection needle nozzle is arranged on the filter layer, the drug-sustained release interlayer and the stent body are wrapped in the coating, and the opening of the injection needle nozzle is exposed from the coating.

[0015] In one embodiment, the injection needle nozzle is funnel-shaped, comprising a base and a degradable head, one end of the base is fused to the filter layer, and the other end extends radially along the airway stent and exceeds the filter layer, and the side of the degradable head away from the base is exposed to the coating.

[0016] 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 coating of the airway stent is radially squeezed, the liquid drug can flow out from the injection needle nozzle.

[0017] A technical effect of an embodiment of the utility model 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, while increasing the soft support at both ends of the airway stent to provide radial support to the end parts of the two ends of the airway stent, while not increasing the stimulation of hard objects, reducing the friction of the end of the stent body on the tracheal wall, thereby reducing the stimulation to the tracheal wall tissue and reducing the possibility of airway restenosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of an airway stent provided by the utility model;

[0019] Figure 2(a) is a partial cross-sectional schematic diagram of one end of the airway stent provided by the utility model when the folding portion is not folded;

[0020] Figure 2 (b) is Figure 1 Partial cross-sectional view along the AA direction ( Figure 2 (a) is a schematic diagram showing that the folded portion is folded on the outside of the airway stent);

[0021] Figure 3 A schematic diagram of the structure of another airway stent provided by the utility model;

[0022] Figure 4 (a) is a partial cross-sectional schematic diagram of one end of another airway stent provided by the utility model when the folding portion is not folded;

[0023] Figure 4 (b) is Figure 1 A partial cross-sectional view of another embodiment along the AA direction ( Figure 4 (a) is a schematic diagram showing that the folded portion is folded on the outside of the airway stent);

[0024] Figure 5 Another airway stent provided by the utility model (corresponding to Figure 4 (b) Structural diagram of the structure;

[0025] Figure 6 for Figure 3 The cross-sectional view along the BB direction;

[0026] Figure 7 for Figure 5 A cross-sectional view of another airway stent along the CC direction;

[0027] Figure 8 for Figure 6 A cross-sectional schematic diagram showing that when the airway stent is squeezed, the silicone coating is deformed and concave toward the inner side of the airway stent relative to the needle nozzle;

[0028] Fig. 9 for Figure 7 A cross-sectional schematic diagram showing that when the airway stent is squeezed, the silicone coating is deformed and concave toward the inner side of the airway stent relative to the needle nozzle;

[0029] Fig.10 for Figure 7 The enlarged view of point D in the middle;

[0030] Fig.11 for Fig.10 A schematic diagram of the base of the injection needle nozzle after the degradable head is degraded;

[0031] Fig.12This is a schematic diagram of the structure of the support system provided by the utility model.

[0032] 100, airway stent; 10, stent body; 10a, proximal end; 10b, distal end; 11, middle section; 12, thinning section; 20, coating; 21, covering portion; 211, single film section; 22, folding portion; 221, connecting end; 222, free end; 223, inner side; 224, outer side; 2241, protrusion; 20a, buffer zone; 30, recovery line; 40, suture; 50, hydrophobic coating;

[0033] 60. drug sustained-release interlayer; 61. drug layer; 62. filter layer; 63. injection needle nozzle; 631. opening; 632. base; 633. degradable head;

[0034] 70. conveying device; 71. guide head; 72. sheath core; 73. sheath tube;

[0035] 170. Bracket system. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant drawings. The drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "inside", "outside", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0038] For ease of description, the following description uses the terms "distal end" and "proximal end", where "distal end" refers to the end of the airway stent that is away from the mouth after implantation, and "proximal end" refers to the end of the airway stent that is close to the mouth after implantation. "Axial" should be understood in this patent to mean the direction in which the airway stent is pushed in and out, that is, the axial direction of its tubular shape. The direction perpendicular to the "axial" is defined as the "radial" direction.

[0039] The utility model provides an airway stent 100, comprising a stent body 10 and a coating 20 disposed on the stent body 10, wherein the stent body 10 is a dense mesh structure formed by weaving or laser cutting of braided wires. In this embodiment, Figure 1As shown, the stent body 10 is formed by one or more braided wires cross-laminated to form a diamond mesh tube structure, and this mesh tube structure can ensure its axial elongation, so that the airway stent 100 has axial extension performance while ensuring radial support. When the airway stent 100 needs to be recovered, the airway stent 100 can be stretched axially by pulling the recovery line 30 to gather one end of the airway stent 100, thereby reducing its radial size to recover the airway stent 100. Among them, the wire diameter of the braided wire can be selected in the range of: 0.14mm~0.4mm, and the material of the braided wire can be selected from an alloy material with shape memory function, such as nickel titanium wire.

[0040] The stent body 10 also includes a middle section 11 and thinned sections 12 connected to both ends of the middle section 11, wherein the wire diameter of the thinned section 12 is smaller than the wire diameter of the middle section 11, and the wire diameter of the thinned 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 thinned section 12 gradually decreases in the direction from the side close to the middle section 11 toward the end away from the side of the middle section 11. In this embodiment, the middle section 11 and the thinning section 12 can be set as an integral 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 thinning sections 12, so that the radial support force of the thinning section 12 is less than the radial support force of the middle section 11. The nickel-titanium wire of the thinning section 12 becomes soft due to the reduced diameter, so as to alleviate the scratching of the hard objects on the tracheal wall at the two ends of the stent, thereby reducing the stimulation of the two ends of the airway stent 100 on the tracheal wall and reducing the possibility of granulation hyperplasia at the contact part between the edges of the two ports of the stent and the tracheal wall. Among them, the thinning section 12 at one end can account for 0 to 30% of the axial length of the stent body 10. In this embodiment, the thinning section 12 at one end accounts for 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, and soften the two ends of the airway stent 100 to reduce the stimulation of the airway stent 100 end to the airway wall.

[0041] 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 the present 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 the use of biopsy forceps to tighten the annular knot and pull the recovery line 30 outward, thereby removing the airway stent 100 for recovery.

[0042] 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 are too densely arranged along the circumferential direction, which increases the friction between the recovery line and the bracket body, thereby causing excessive pulling resistance of the recovery line and being unfavorable for recovery.

[0043] The coating 20 includes a covering portion 21 and a folding portion 22, wherein 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 portions of the airway stent at both ends, while not increasing the stimulation of hard objects, reducing the friction of the end of the stent body 10 on the hard objects of the tracheal wall, thereby reducing the stimulation to the tracheal wall tissue and reducing the possibility of airway restenosis.

[0044] The edge of the coating 20 exceeds the edge of the stent body 10, and the portion of the coating 20 that exceeds the stent body 10 at both ends is a 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, Figure 1 Combination Figure 2 As shown in (b), 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 is not covered on the stent body 10 is called a single film segment 211; Figure 2 Middle (a) - Figure 2 As shown in (b), the folded portion 22 is folded from the end of the covering portion 21 toward the outside of the airway stent 100, wherein the folded portion 22 and the overlapping portion of the single film segment 211 and the single film segment 211 together form the 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 against the hard object of the tracheal wall, and thus reduce the stimulation to the tracheal wall tissue. The length range of the buffer zone 20a in the axial direction is: 1mm ~ 3mm; the length range of the stent body 10 of the airway stent 100 in the axial direction is: 20mm-120mm;

[0045] The folding portion 22 includes a connecting end 221 and a free end 222. The connecting end 221 is connected to the end of the single film segment 211, and the free end 222 can be sutured to the airway stent 100 by forming a cuff suture 40. Figure 1 Combination Figure 2 As shown in (b), the hem suture 40 sews the free end 222 around the circumference, thereby fixing the free end 222 on the stent body 10. The folded portion 22 can be a continuous film in the entire circumference, or it can be a film strip spaced apart in the circumference. When the spaced film strips are folded, the free end 222 is fixed to the stent body 10. Figure 3 As shown in FIG. 1 , the folded portion 22 is disposed at a position where the end edge of the stent body 10 has a tip (i.e., at the corner of the rhombus) to reduce the hard object stimulation of the stent body 10 on the airway wall. In other embodiments, the folded portion 22 may be a film strip with a gap at one end, such as Figure 3 The proximal end of the airway stent 100 is shown, and the other end is a circumferentially continuous membrane, such as Figure 3 The distal end of the airway stent 100 is shown; it may also be a membrane strip with intervals at both ends, or a membrane with circumferential continuity at both ends, which is not limited here.

[0046] The coating 20 is wrapped on the stent body 10. The material of the coating 20 can be selected from polymer films such as medical silicone or polyurethane, and the coating 20 is in a colloidal form when coated on the stent body 10, so that the coating 20 also has ductility and elasticity in the axial direction. It is understandable that the coating 20 can wrap the stent body 10 by soaking in a solution so that the stent body 10 is not exposed to the outside, or it can be coated on the stent body 10 by other methods. The way in which the coating 20 is coated on the stent body 10 is not limited. In other embodiments, the inner side surface 223 of the coating 20 can form a smooth surface to reduce the possibility of sputum plug retention, and the outer side surface 224 of the coating 20 can form a concave-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, such as Figure 7 As shown, the retention and adhesion of sputum plugs can be further reduced, thereby reducing the risk of tracheal restenosis caused by sputum plug retention.

[0047] In this embodiment, if Figure 4 Middle (a) - Figure 4 (b) Combined Figure 5 As shown, the folded portion 22 includes an inner side 223 and an outer side 224, wherein the inner side 223 is a side close to the covering portion 21, and the outer side 224 is a side away from the covering portion 21. Figure 4As shown in (b), 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, avoid the displacement of the airway stent 100, and further compensate for the problem of reduced radial support force of this part caused by the thinning of the thinning segment 12. At least two protrusions 2241 are arranged at intervals along the axial direction, and the height of the two protrusions 2241 gradually decreases from the end of the airway stent 100 toward the middle part of the airway stent in the axial direction. In this embodiment, three protrusions 2241 are arranged at intervals along the axial direction, and the height of the three protrusions 2241 gradually decreases from the end of the airway stent 100 toward the middle section 11 of the airway stent 100 to complement the change in the wire diameter of the thinning segment 12, which can further compensate for the radial support force of the stent body 10 reduced by the thinning segment 12.

[0048] In this embodiment, if Figure 3 As shown, a developing member 70 is also 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 wires 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 the axial offset is not much (the circumferential offset central angle does not exceed 10°), and another three 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.

[0049] In this embodiment, if Figure 6-11 As shown, the airway stent 100 also includes a drug-releasing interlayer 60, which 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 adheres 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, and the opening 631 of the injection needle nozzle 63 is exposed from the coating 20, as shown in FIG. Figure 6 shown.

[0050] like Figure 6 As shown in combination with 10-11, the injection needle nozzle 63 is funnel-shaped, and the injection needle nozzle 63 includes a base 632 and a degradable head 633, wherein the base 632 is a large-mouthed end of the funnel, and the degradable head 633 is a small-mouthed end of the funnel. One end of the base 632 is fused to the filter layer 62, and the other end extends along the radial direction of the airway stent 100 and exceeds the filter layer 62. The side of the degradable head 633 away from the base 632 (the opening of the small-mouthed end) is exposed to the coating 20, as shown in FIG. Figure 7The drug layer 61 is a soft colloid at room temperature or below room temperature (25°C), and melts into a liquid at a temperature above room temperature. When the coating 20 of the airway stent 100 is radially squeezed, the silicone coating 20 is deformed, so that the liquid drug can flow out from the injection needle nozzle 63. Fig. 9 As shown, it can reduce the proliferation of tumor tissue or the growth of tracheal wall smooth muscle tissue, reduce granulation hyperplasia, and thus reduce the possibility of airway restenosis.

[0051] The main component of the drug layer 61 is sirolimus aqueous solution, and 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 sirolimus aqueous solution can be selected as 1mg / ml; gelatin can be selected from pharmaceutical grade gelatin, and the concentration is greater than 98%; glycerol can be selected from medical grade glycerol, and the concentration is greater than 98%; hydroxyphenyl ester is selected from a sample with a concentration greater than 98%, and the mass percentage of the above ingredients is selected to be sirolimus: gelatin: glycerol: hydroxyphenyl ester = 10 (±1): 20 (±2): 67 (±2): 3 (±1) to mix and configure the above drug layer. When the temperature exceeds 30°C, the drug layer 61 is completely dissolved into a liquid state.

[0052] like Figure 9-10 As shown, the filter layer 62 is arranged on the side of the drug layer 61 away from the stent body 10. The filter layer 62 can be made of meltblown cloth with higher toughness. The meltblown cloth can be set in two layers, and then part of the base 632 of the injection needle nozzle 63 is welded between the two layers of meltblown cloth, so that the filter layer 62 and the injection needle nozzle are welded as a whole, and the end of the base 632 close to the degradable head 633 is not exposed from the coating. Among them, the base 632 can be partially set to polyester material, and the material of the degradable head 633 can be selected from left-handed polylactic acid material. Left-handed polylactic acid is degradable, and the degradation period of the degradable head 633 is about 2 months. When the degradable head is degraded, the structure of the base relative to the meltblown cloth is as shown Fig.11 As shown, the base 632 is welded between two layers of meltblown cloth, and the side of the base 632 close to the degradable head 633 is a smoothly transitioned arc structure, which further reduces the irritation to the airway wall on the basis of the coating isolation.

[0053] 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 melted liquid drug layer 61 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.

[0054] The utility model also provides a bracket system 170, such as Fig.12 As shown, it includes 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 by using the delivery device 70, the airway stent 100 can be released by withdrawing the sheath tube 73 so that the airway stent 100 expands naturally and adheres to the airway wall.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0056] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An airway stent, characterized in that: The airway stent comprises a stent body and a coating disposed on the stent body, wherein the coating comprises 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 an end portion of the covering portion.

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

3. The airway stent according to claim 1, characterized in that: The stent body comprises a middle section and thinned sections connected to two ends of the middle section, and the wire diameter of the thinned section is smaller than that of the middle section.

4. The airway stent according to claim 1, characterized in that: The stent body also 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.

5. The airway stent according to claim 1, characterized in that: 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 coating portion, and the free end can be sutured to the stent body by means of sutures.

6. The airway stent according to claim 1, characterized in that: The end of the coating exceeds the end of the stent body, so that the exceeding portion of the coating forms a buffer zone.

7. The airway stent according to claim 1 or 5, characterized in that: The folding portion includes an inner side surface and an outer side surface, wherein the inner side surface is a side close to the covering portion, and the outer side surface is a side away from the covering portion, and the outer side surface is provided with at least one protrusion.

8. The airway stent according to claim 7, characterized in that: 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 of the airway stent toward the middle part of the airway stent.

9. The airway stent according to claim 1, characterized in that: The surface of the covering portion located on the inner side of the airway stent is provided with a hydrophobic coating.

10. The airway stent according to claim 1, characterized in that: The airway stent also includes a drug-sustained-release 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-sustained-release interlayer and the stent body are wrapped in the coating, and the opening of the injection needle nozzle is exposed from the coating.

11. The airway stent according to claim 10, characterized in that: The injection needle nozzle is funnel-shaped and includes a base and a degradable head. One end of the base is fused 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.

12. The airway stent according to claim 10, characterized in that: The drug layer is a soft colloid at room temperature or below, and melts into a liquid state 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.

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