Absorbable tracheal stent with drug coating

Abstract

The invention relates to the technical field of medical instruments, in particular to an absorbable tracheal stent containing a drug coating, which comprises a cylindrical shell, the shell comprises a longitudinal skeleton, a ring-shaped skeleton, an extension drug groove and an assembly groove, and the extension drug groove is filled with a drug coating strip; a covering film is pasted on the outer portion of the shell and comprises a tightening film, a contact film and a sealing film. According to the invention, the sealing film is firstly degraded in the trachea of a patient, and the stress on the shell corresponding to the outward expanding medicine groove is released, so that the outward expanding medicine groove is expanded, the outer diameter of the whole tracheal stent is increased, and the medicine coating strip is driven to synchronously expand outwards to abut against an affected part, so that the stent can be automatically degraded in the body of the patient; and the expansion force of the stent can be slowly released in the degradation process, so that the reduction of the expansion force of the stent caused by thinning of the wall of the degraded stent or natural growth of the trachea is counteracted, the expansion force of the stent is dynamically maintained, and the stability of the stent is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, in particular to an absorbable tracheal stent containing a drug coating. Background Art

[0002] A tracheal stent is a prosthesis used to address tracheal lumen obstruction or stenosis. It is a device used in tracheal lumen shaping surgery. It maintains the diameter and patency of the tracheal lumen by resisting pressure from the tracheal lining and providing internal support. It is commonly used to treat tracheal and bronchial stenosis caused by inflammatory granulomas, scars, tuberculosis, trauma, tracheomalacia, amyloidosis, and tumors. Airway stenosis can cause obstructive pneumonia, atelectasis, and dyspnea. Patients experience symptoms such as dyspnea, wheezing, and choking. Severe cases can develop respiratory failure and be life-threatening. Tracheal stent placement is an important treatment for airway stenosis, quickly relieving dyspnea and improving clinical symptoms.

[0003] Patent application number CN106626374A discloses a tracheal stent for infants and young children. The stent is cylindrical with a notch, and the cross-section of the cylinder is C-shaped. The central angle of the C-shaped notch is 75°-115°. The inner diameter of the stent is 6mm-7mm, the wall thickness is 0.4mm-0.6mm, and the length is 20mm-100mm. On the inner side of the stent, a groove with a width of 1mm and a depth of 0.1mm is provided every 5mm in the longitudinal direction. On the wall of the stent, at least four square holes with a length of 2mm and a width of 1mm are evenly distributed laterally between each two grooves. The stent is made of polyacrylate / polymethacrylate photosensitive resin PIC100 and is obtained by 3D printing.

[0004] Its C-shaped structure can indeed better fit the lesioned area of ​​the trachea in children. It has stress in the cross-sectional direction, making it less likely to slip, and the gaps can also play a certain adaptive role. However, since the resin material still needs to be removed from the body after full recovery, its stress will change with the pressure of the tracheal wall while in the body, and the patient may feel uncomfortable. In addition, when the hollow stent is placed in the trachea, new granulation tissue is likely to grow along the edges of the hollow or hard objects, which can easily lead to restenosis of the trachea. Summary of the Invention

[0005] In order to overcome the defects in the prior art, the purpose of the present invention is to provide an absorbable tracheal stent containing a drug coating to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides an absorbable, drug-coated tracheal stent, comprising a cylindrical housing, the housing comprising four longitudinal frames, a plurality of ring-shaped frames equally spaced between the longitudinal frames, a plurality of external drug slots for storing drugs defined in the outer wall of the housing, an assembly slot provided on the inner side of the ring-shaped frames and located between adjacent external drug slots, and a skirt slot provided on the inner side of the housing and located between adjacent ring-shaped frames. The outside of the shell is glued with a covering film, and the covering film includes a shrinking film that is glued and wrapped around the outside of the shell. The shrinking film includes a contact film for sticking to the outside of the shell corresponding to the assembly groove and a closing film for closing the side notches of the external medicine groove. The external medicine groove is filled with a drug coating strip; when the closing film degrades, the external medicine groove expands outward and drives the drug coating strip to expand outward synchronously.

[0007] As a further improvement of the present technical solution, the external medicine groove and the assembly groove are both centrally symmetrically arranged, the materials of the shell and the coating are both biodegradable and elastic polylactic acid materials, the glue on the inner wall of the coating used for bonding to the outer wall of the shell is polylactic acid glue, and the thickness of the glue is less than the thickness of the shrink film.

[0008] As a further improvement of the present technical solution, all longitudinal frames, all the external medicine grooves and all the assembly grooves are parallel to each other, the inner groove of the assembly groove is in an arc shape, the inner groove of the external medicine groove is in an arc shape and a number of spherical convex hairs are fixed on the groove wall, and all the spherical convex hairs are arranged in a matrix with equal spacing.

[0009] As a further improvement of the present technical solution, at least four of the ring-shaped skeletons are provided, and the inner height of the ring-shaped skeleton away from the middle of the shell is smaller than the inner height of the ring-shaped skeleton close to the middle of the shell.

[0010] As a further improvement of the present technical solution, the depth of the external medicine groove is at least one tenth of the outer diameter of the shell; the thickness of the longitudinal skeleton and the annular skeleton are equal, and the thickness of the two is at most one third of the depth of the external medicine groove; the thickness of the tightening membrane is at most one third of the thickness of the annular skeleton.

[0011] As a further improvement of the present technical solution, the groove depth of the assembly groove is equal to the groove depth of the external medicine groove, and the length of the contact membrane is less than or equal to the outer arc length of the shell corresponding to the assembly groove.

[0012] As a further improvement of the present technical solution, the length of the closing membrane is greater than or equal to the width of the slot of the external medicine slot.

[0013] As a further improvement of the technical solution, a degradation groove is vertically opened on the inner side wall of each of the closing films, and the degradation groove is located in the center of the closing film.

[0014] As a further improvement of the present technical solution, the width of the shrinking film is equal to the length of the shell, the length of the shrinking film is greater than or equal to the outer circumference of the shell, and a circular cover film is integrally formed at the upper and lower edges of the closing film, and the thickness of the cover film is less than the thickness of the closing film.

[0015] As a further improvement of the present technical solution, a number of cover film flaps for fixing the cover film are integrally formed at the arc edge of the cover film. The shape of the cover film is similar to the cross-sectional shape of the external medicine groove, and the size of the cover film is greater than or equal to the cross-sectional size of the external medicine groove.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The absorbable and drug-coated tracheal stent has a ring-shaped skeleton, an external drug groove, a contact membrane, a sealing membrane, and a drug coating. When the stent is placed in the trachea, the sealing membrane is first degraded, thereby releasing the stress in the ring-shaped skeleton corresponding to each external drug groove one by one. The outer diameter of the entire tracheal stent is then expanded, and the drug coating strip is driven to expand outward synchronously to press against the patient's area. This allows the stent to self-degrade in the patient's body and slowly release its expansion force during the degradation process, thereby offsetting the reduction in the stent expansion force caused by the thinning of the stent wall after degradation or the natural growth of the trachea, dynamically maintaining the stent expansion force, and increasing the stability of the stent.

[0017] 2. The absorbable and drug-coated tracheal stent has spherical convex hairs arranged in the external drug groove, so that the drug coating strip can be better attached to the external drug groove after filling. When the drug coating strip expands outward and presses against the patient's area, it can ensure that the drug acts on the patient's area for a longer time; there is no hollowing on the outside of the stent, thereby avoiding tracheal restenosis caused by the growth of granulation tissue and scars; because the stent material is made of degradable material, the longitudinal skeleton and the ring skeleton are thicker than the shell part corresponding to the skirt groove, which can maintain the overall strength of the stent while saving materials, and the inner height of the ring skeleton away from the middle of the shell is smaller than the inner height of the ring skeleton close to the middle of the shell, so that when the skeleton part degrades, it degrades from both ends to the middle, reducing the probability of the degraded stent breaking before the middle degradation, thereby increasing the stability and safety of the stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the drawings are merely illustrative and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances under the guidance of the present invention.

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the shell in the expanded state of the present invention; Figure 3 For the present invention Figure 1 One of the partial enlarged images of point A in the middle; Figure 4 For the present invention Figure 1 The second partial enlarged view of point A in the middle; Figure 5 For the present invention Figure 2 A partial enlarged view of point B in the middle; Figure 6 This is a schematic diagram of the structure of the spherical convex hairs in the present invention; Figure 7 It is a schematic diagram of the top surface structure of the present invention; Figure 8 It is a schematic diagram of the transverse cross-sectional structure of the present invention; Figure 9 Schematic diagram of the transverse cross-sectional structure of the housing in the present invention; Figure 10 For the present invention Figure 8 A partial enlarged view of point C in the middle; Figure 11 Schematic diagram of the local structure of the coating in the present invention; Figure 12 For the present invention Figure 11 A partial enlarged view of point D in the middle; The meaning of each number in the figure is: 1. Shell; 10. Longitudinal frame; 11. Ring frame; 110. External medicine slot; 111. Assembly slot; 12. Skirt slot; 13. Ball convex hair; 2. Laminating film; 20. Shrinking film; 201. Contact film; 202. Sealing film; 2021. Degradation tank; 21. Covering film; 22. Covering film flap; 3. Drug-coated strips. DETAILED DESCRIPTION

[0020] The details of the present invention can be more clearly understood in conjunction with the accompanying drawings and the description of the specific embodiments of the present invention. However, the specific embodiments of the present invention described herein are for the purpose of explaining the present invention only and are not to be construed as limiting the present invention in any way. Based on the teachings of the present invention, skilled artisans can conceive of any possible variations based on the present invention, which should be considered to fall within the scope of the present invention. The terms "mounted" and "connected" should be understood broadly and can refer to direct connection or indirect connection through an intermediary.

[0021] The terms "central axis," "vertical," "horizontal," "front," "back," "up," "down," "left," "right," "top," "bottom," "inside," and "outside" used herein to indicate positions or location relationships are based on the positions or location relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, in the description of the present invention, "several" means two or more, unless otherwise specifically defined.

[0022] See also Figures 1-12 As shown, the present invention provides an absorbable and drug-coated tracheal stent, comprising a cylindrical shell 1, the shell 1 including four longitudinal frames 10, a plurality of ring-shaped frames 11 equally spaced between the longitudinal frames 10, a plurality of external drug slots 110 for storing drugs on the outer wall of the shell 1, an assembly slot 111 provided inside the ring-shaped frames 11 and located between two adjacent external drug slots 110, and a skirt slot 12 provided inside the shell 1 and located between two adjacent ring-shaped frames 11. The skirt slot 12 can reduce the material usage of the tracheal stent, thereby reducing the manufacturing cost. The outside of the shell 1 is glued with a covering film 2, which includes a shrinking film 20 that is pasted and wrapped around the outside of the shell 1. The shrinking film 20 includes a contact film 201 for pasting on the outside of the shell 1 corresponding to the assembly groove 111 and a closing film 202 for closing the side notch of the external medicine groove 110. The external medicine groove 110 is filled with a drug coating strip 3; when the closing film 202 degrades, the external medicine groove 110 expands outward and drives the drug coating strip 3 to expand outward synchronously, so that the drug coating strip 3 can also resist the tracheal wall so that the drug can continuously and fully act on the inner wall of the trachea.

[0023] Among them, the external medicine groove 110 and the assembly groove 111 are both arranged symmetrically with the center, and the materials of the shell 1 and the coating 2 are both biodegradable and elastic polylactic acid materials, so as to ensure that the outer diameter of the stent can be reduced to a level that is easy to move from the throat to the tracheal stenosis before it is placed in the target position; the glue on the inner wall of the coating 2 used for bonding with the outer wall of the shell 1 is polylactic acid glue, and the thickness of the glue is less than the thickness of the shrink film 20, so as to ensure that the glue can be degraded before the shell 1.

[0024] Preferably, all longitudinal skeletons 10, all external medicine grooves 110 and all assembly grooves 111 are parallel to each other, the inner groove of the assembly groove 111 is in an arc shape, the inner groove of the external medicine groove 110 is in an arc shape and a number of spherical convex hairs 13 are fixed on the groove wall, and all spherical convex hairs 13 are arranged in a matrix with equal spacing, so that the drug coating strip can better adhere to the external medicine groove after filling, and when the drug coating strip expands outward and presses against the patient's area, it can ensure that the drug acts on the patient's area for a longer time.

[0025] Specifically, at least four ring-shaped skeletons 11 are provided, and the inner height of the ring-shaped skeleton 11 away from the middle of the shell 1 is smaller than the inner height of the ring-shaped skeleton 11 close to the middle of the shell 1, so that the longitudinal skeleton 10 and the ring-shaped skeleton 11 degrade from both ends to the middle, reducing the probability of the degraded bracket breaking before the middle, thereby increasing the stability and safety of the bracket.

[0026] Specifically, the depth of the external medicine groove 110 is at least one tenth of the outer diameter of the shell 1; the thickness of the longitudinal skeleton 10 and the ring-shaped skeleton 11 are equal, and the thickness of both is at most one third of the depth of the external medicine groove 110 to ensure that the stent has a sufficient ventilation inner diameter; the thickness of the tightening membrane 20 is at most one third of the thickness of the ring-shaped skeleton 11 to ensure that the tightening membrane 20 is degraded before the shell 1.

[0027] Specifically, the groove depth of the assembly groove 111 is equal to the groove depth of the external medicine groove 110, and the length of the contact film 201 is less than or equal to the external arc length of the shell 1 corresponding to the assembly groove 111, thereby ensuring that the contact film 201 can be completely adhered to the outside of the shell 1 part corresponding to the assembly groove 111.

[0028] Specifically, the length of the closing film 202 is greater than or equal to the width of the slot of the external medicine slot 110, thereby ensuring that the tightening film 20 applies tension to the two side shells 1 corresponding to the slot of the external medicine slot 110 to lock the expansion force at the slot of the external medicine slot 110.

[0029] Preferably, a degradation groove 2021 is vertically opened on the inner wall of each closing film 202, and the degradation groove 2021 is located in the center of the closing film 202, so that the closing film 202 can degrade faster at the rapid degradation groove 2021, thereby releasing the expansion force at the notch of the external medicine groove 110.

[0030] Preferably, the width of the shrinking film 20 is equal to the length of the shell 1, and the length of the shrinking film 20 is greater than or equal to the outer circumference of the shell 1 so as to better seal and tighten the outside of the shell 1. The upper and lower edges of the closing film 202 are integrally formed with a circular cover film 21, and the thickness of the cover film 21 is less than the thickness of the closing film 202, so that it can be degraded first so as not to affect the degradation of the closing film 202 to release the expansion force at the notch of the external medicine groove 110 and the drug coating strip 3.

[0031] Preferably, a plurality of cover film flaps 22 for fixing the cover film 21 are integrally formed at the arc edge of the cover film 21. The shape of the cover film 21 is similar to the cross-sectional shape of the external medicine groove 110, and the size of the cover film 21 is greater than or equal to the cross-sectional size of the external medicine groove 110. The inner side of the cover film flap 22 is also coated with degradable glue. The cover film flap 22 can be folded inward and adhered to the edge of the corresponding end ring-shaped frame 11, so as to better fix the cover film 21 and close the upper and lower ends of the drug coating strip 3.

[0032] Working principle of the present invention: After the tracheal stent is placed in the patient's tracheal diseased area for a period of time, the shrink film 20 degrades and cracks from the several degradation grooves 2021, and the external tension stress of the external drug groove 110 corresponding to the ring-shaped skeleton 11 is released, which increases the expansion force of the stent, offsetting the insufficient expansion force of the stent caused by the thinning of the stent wall after degradation or the natural growth of the trachea. At the same time, the drug coating strips 3 in the external drug groove 110 also press outward against the narrow part of the inner wall of the trachea, allowing the drug to fully act there.

[0033] Finally, it should be noted that the above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent variations or modifications made in accordance with the spirit and substance of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. An absorbable, drug-coated tracheal stent, characterized by: The invention comprises a shell (1) in the shape of a cylindrical tube, wherein the shell (1) comprises four longitudinal frames (10), a plurality of ring-shaped frames (11) arranged at equal intervals between the longitudinal frames (10), a plurality of external medicine slots (110) for storing medicines provided on the outer wall of the shell (1), an assembly slot (111) arranged on the inner side of the ring-shaped frames (11) and located between two adjacent external medicine slots (110), and a skirt slot (12) arranged on the inner side of the shell (1) and located between two adjacent ring-shaped frames (11); The outer portion of the shell (1) is adhered with a coating (2) by glue, and the coating (2) includes a shrink film (20) adhered and wrapped around the outer portion of the shell (1), and the shrink film (20) includes a contact film (201) for adhering to the outer portion of the shell (1) corresponding to the assembly groove (111) and a closing film (202) for closing the side notch of the external medicine groove (110), and the external medicine groove (110) is filled with a medicine coating strip (3); when the closing film (202) degrades, the external medicine groove (110) expands outward and drives the medicine coating strip (3) to expand outward synchronously.

2. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: The external medicine groove (110) and the assembly groove (111) are both centrally symmetrically arranged. The shell (1) and the coating (2) are both made of biodegradable and elastic polylactic acid. The glue on the inner wall of the coating (2) for bonding to the outer wall of the shell (1) is polylactic acid glue, and the thickness of the glue is less than the thickness of the shrink film (20).

3. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: All longitudinal frames (10), all external medicine grooves (110) and all assembly grooves (111) are parallel to each other, the inner groove of the assembly groove (111) is in an arc shape, the inner groove of the external medicine groove (110) is in an arc shape and a plurality of spherical convex hairs (13) are fixedly provided on the groove wall, and all the spherical convex hairs (13) are arranged in a matrix shape with equal spacing.

4. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: At least four of the ring-shaped frames (11) are provided, and the inner height of the ring-shaped frames (11) away from the middle of the shell (1) is smaller than the inner height of the ring-shaped frames (11) close to the middle of the shell (1).

5. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: The groove depth of the external medicine groove (110) is at least one tenth of the outer diameter of the shell (1); the thickness of the longitudinal skeleton (10) and the ring-shaped skeleton (11) are equal, and the thickness of both is at most one third of the groove depth of the external medicine groove (110); the thickness of the tightening membrane (20) is at most one third of the thickness of the ring-shaped skeleton (11).

6. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: The groove depth of the assembly groove (111) is equal to the groove depth of the external medicine groove (110), and the length of the contact membrane (201) is less than or equal to the outer arc length of the shell (1) corresponding to the assembly groove (111).

7. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: The length of the closing film (202) is greater than or equal to the width of the slot of the external medicine slot (110).

8. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: A degradation groove (2021) is vertically provided on the inner side wall of each of the closing films (202), and the degradation groove (2021) is located in the center of the closing film (202).

9. The absorbable drug-coated tracheal stent according to claim 1, characterized in that: The width of the shrink film (20) is equal to the length of the shell (1), and the length of the shrink film (20) is greater than or equal to the outer circumference of the shell (1). A circular cover film (21) is integrally formed at the upper and lower edges of the closing film (202), and the thickness of the cover film (21) is less than the thickness of the closing film (202).

10. The absorbable drug-coated tracheal stent according to claim 9, characterized in that: A plurality of cover film flaps (22) for fixing the cover film (21) are integrally formed at the arc edge of the cover film (21); the shape of the cover film (21) is similar to the cross-sectional shape of the external medicine groove (110), and the size of the cover film (21) is greater than or equal to the cross-sectional size of the external medicine groove (110).

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