Gradient degradable tracheal stent for expanding tracheal stenosis and plugging orificium fistulae

Abstract

The utility model relates to a gradient degradable tracheal stent for expanding tracheal stenosis and blocking fistula. The gradient degradable tracheal stent comprises integral woven structures (I) located on the two sides of the stent and a local woven structure (II) located in the center of the stent. The integral woven structure (I) and the local woven structure (II) are both formed by weaving degradable metal wires (1) and degradable polymer fibers (2) in a mixed mode. Compared with a covered woven stent, the tracheal stent has more accurate mechanical enhancement and plugging effects, the tracheal stent has gradient degradation speed after being implanted, the maximum mechanical property and plugging effect are provided in the initial stage of treatment, the mechanical supporting effect and the plugging effect are gradually reduced along with tracheal healing, and the tracheal stent has the advantages of being good in sealing effect and good in sealing effect. The stent can be completely degraded and does not need to be taken out again through an operation, the pain of a patient is relieved, and good application prospects are achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of medical apparatus and instruments, especially relates to a gradient degradable tracheal stent for dilating tracheal stenosis and plugging fistula. BACKGROUND

[0002] Trachea is the only passage for gas exchange in human body, which is formed by alternately arranged cartilage rings and inter-ring connective tissue, wherein the cartilage tissue provides mechanical support to maintain the patency of trachea, and the inter-ring connective tissue has axial bending flexibility to adapt to the movement of head and neck. Tracheal stenosis caused by intratracheal and extratracheal malignancies is a clinically critical condition, especially in the case of patients with advanced esophageal cancer combined with tracheoesophageal fistula, the patients have symptoms such as dyspnea, eating coughing, pulmonary infection, etc., and will die in a short time if not treated in time. With the improvement of medical level, tracheal stent implantation has become an important means for treating tracheal stenosis and tracheal fistula, and its main purpose is to dilate the stenosis of trachea caused by lesions, maintain the patency of airway and plug the fistula.

[0003] At present, the tracheal stent mainly includes silicone stent, metal stent and degradable stent. The silicone stent has the advantages of less new granulation and easy removal, but the stent is easy to shift after implantation and has weak supporting force; the metal stent has the advantages of strong supporting force and less shift, but the metal stent has large mesh on the surface, cannot plug the fistula, and the granulation tissue is easy to grow inward to cause tracheal restenosis. At present, a layer of plugging film is usually covered on the metal surface to block the mesh, but the plugging film is easy to be damaged after implantation and lose effectiveness. In addition, the long-term retention of the stent in the body is easy to cause inflammation and complications, so the stent needs to be removed again after the treatment period. Therefore, at present, there is an urgent need for a tracheal stent capable of dilating tracheal stenosis and plugging fistula to solve the problems of insufficient supporting force of the stent, restenosis, easy shift and the need for reoperation during stent implantation treatment. SUMMARY

[0004] The utility model wants to solve the technical problem to provide a kind of gradient degradable tracheal stent for dilating tracheal stenosis and plugging fistula, relative to the film knitted stent more has the effect of accurate mechanical enhancement and plugging, and tracheal stent is implanted in the gradient degradation rate, provide the biggest mechanical property and plugging effect in the initial stage of treatment, with tracheal healing gradually reduce mechanical support effect and plugging effect, stent can be completely degraded without reoperation, reduce the pain of patient, with good application prospect.

[0005] The utility model provides a kind of gradient degradable tracheal stent for dilating tracheal stenosis and plugging fistula, including the whole braided structure in the stent both sides and the local woven structure in the stent center;The whole braided structure and local woven structure are obtained by the mixed weaving of degradable metal wire and degradable polymer fiber.

[0006] Preferably, the whole woven structure comprises a diamond woven structure, a regular woven structure or a three-phase woven structure.

[0007] Preferably, the local woven structure comprises a plain weave, a twill weave, a satin weave, a leno weave, a mesh weave, a honeycomb weave or a double-layer weave.

[0008] Preferably, the local woven structure is composed of warp yarns and weft yarns, the warp yarns are of the same material as the woven structure, and the weft yarns can be of the same or different material as the woven structure. The density of the warp yarns and weft yarns of the local woven structure is 20-400 per 10 cm. The density of the warp yarns and weft yarns determines the porosity and mechanical properties of the tracheal stent surface, which can be set according to the support force and occlusion requirements of the tracheal stent.

[0009] Optionally, the size, area, length, diameter and shape of the whole woven structure are set according to the size, dimension and location of the stenosis and the tracheal tissue condition.

[0010] Optionally, the size, area, length, diameter, shape and location of the local woven structure in the tracheal stent are set according to the size, dimension and location of the fistula and the tracheal tissue condition.

[0011] Preferably, the material of the degradable metal wire is magnesium, zinc or an alloy material thereof.

[0012] Preferably, the diameter of the degradable metal wire is 0.1-0.5 mm. If the diameter is less than 0.1 mm, the tracheal stent is prone to collapse, and if the fineness is higher than 0.5 mm, the interaction between the tracheal stent and the trachea may be too large to cause tracheal damage.

[0013] Preferably, the material of the degradable polymer fiber is one or more of polydioxanone, poly-p-dioxanone and polylactic acid.

[0014] Preferably, the diameter of the degradable polymer fiber is 0.1-0.5 mm. If the diameter is less than 0.1 mm, the tracheal stent is prone to collapse, and if the fineness is higher than 0.5 mm, the interaction between the tracheal stent and the trachea may be too large to cause tracheal damage.

[0015] Preferably, the number of the degradable metal wires and degradable polymer fibers is 10-500. If the number is less than 10, the porosity of the stent is large, making it difficult to expand the tracheal stenosis and occlude the fistula. If the number is greater than 500, the stent loses the expansion and compression ability after being stressed, and the weaving technology barrier is extremely high.

[0016] Preferably, the shape of the tracheal stent can be straight cylinder, single / double horn, biomimetic shape, etc. The shape of the tracheal stent can be set according to the processing requirements.

[0017] Further, the gradient-degradable tracheal stent further comprises a degradable blocking film encapsulated in the local woven structure. The degradable blocking film can further enhance the effect of the tracheal stent on fistula sealing, and the area and position of the degradable blocking film are set according to the size of the fistula and the relative position of the tracheal stenosis site.

[0018] The gradient-degradable tracheal stent of the utility model is an integrated structure woven and knitted by biodegradable polymer fibers and degradable metal wires. The overall knitted structure of the stent enables the stent to be compressed for delivery and expanded after implantation to adhere to the trachea, facilitating stent implantation and preventing slippage. The local woven structure of the stent can achieve the functions of blocking the fistula and preventing the ingrowth of granulation by high-density weaving. Considering the shorter healing period of tracheal fistula and the longer healing period of tracheal stenosis, the mixed weaving structure of degradable polymer fibers and degradable metal wires provides sufficient support force at the initial implantation stage, and the polymer fibers provide gradient-changing support force and blocking effect at the pre-, mid-, and post-implantation stages.

[0019] Advantageous effects

[0020] After the utility model is implanted into the diseased trachea, the overall knitted structure has the function of expanding the tracheal stenosis site, and the local woven structure has the functions of blocking the tracheal fistula and providing mechanical support. Compared with the covered knitted stent, the utility model has more precise mechanical enhancement and blocking effect. Moreover, the tracheal stent has a gradient degradation rate after implantation, providing the maximum mechanical properties and blocking effect at the initial stage of treatment, gradually reducing the mechanical support effect and blocking effect as the trachea heals, and the stent can be completely degraded without the need for reoperation, thereby reducing the patient's pain and having good application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 Fig. 1 is a structural schematic diagram of the utility model stent.

[0022] Fig. 2 Fig. 2 is an expanded view of the utility model stent.

[0023] Fig. 3 Fig. 3 is a schematic diagram of the overall knitted structure in the utility model stent.

[0024] Fig. 4 Fig. 4 is a schematic diagram of the local woven structure in the utility model stent. DETAILED DESCRIPTION

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] Example 1

[0027] Depend on Figs. 1-2 As shown, this embodiment provides a graded degradable tracheal stent for dilating tracheal stenosis and sealing fistulas, including an integral braided structure I located on both sides of the stent and a local woven structure II located in the center of the stent; both the integral braided structure I and the local woven structure II are made of a mixture of degradable metal wires 1 and degradable polymer fibers 2.

[0028] As an example, by Fig. 3 As shown, the overall braided structure I adopts a diamond braided structure. The biodegradable metal wire 1 is made of magnesium metal wire. The biodegradable polymer fiber 2 is made of polydioxanone fiber. The diameter of the magnesium metal wire is 0.2 mm, and the diameter of the polydioxanone fiber is 0.3 mm.

[0029] As an example, by Fig. 4 As shown, the partial woven structure II employs a plain weave structure. The warp yarns of the partial woven structure II are the same magnesium wire and polydioxanone fiber as the overall woven structure I. The diameter of the magnesium wire is 0.2 mm, and the diameter of the polydioxanone fiber is 0.3 mm. The weft yarns of the partial woven structure II are the same polydioxanone fiber as the overall woven structure. The warp density is 200 yarns / 10 cm, and the weft density is 100 yarns / 10 cm.

[0030] For example, the total number of magnesium wires and polydioxanone fibers is 110.

[0031] For example, the tracheal stent is cylindrical in shape.

[0032] After the tracheal stent of this embodiment is implanted into the diseased trachea, the overall woven structure has the function of expanding the tracheal stenosis, and the local woven structure has the function of sealing the tracheal fistula and providing mechanical support. Compared with the covered woven stent, it has more precise mechanical enhancement and sealing effect. Moreover, the tracheal stent degrades at a gradient rate after implantation, providing the maximum mechanical performance and sealing effect in the early stage of treatment. As the trachea heals, the mechanical support and sealing effect gradually decrease. The stent can be completely degraded without the need for surgical removal, reducing the patient's pain.

Claims

1. A gradeably degradable tracheal stent for dilating tracheal stenosis and sealing fistulas, characterized in that: The stent includes an integral woven structure (I) located on both sides of the stent and a partial woven structure (II) located in the center of the stent; both the integral woven structure (I) and the partial woven structure (II) are made of biodegradable metal wires (1) and biodegradable polymer fibers (2); the warp and weft density of the partial woven structure (II) is 20-400 threads / 10cm; the graded degradable tracheal stent also includes a biodegradable sealing membrane encapsulated inside the partial woven structure (II).

2. The graded degradable tracheal stent according to claim 1, characterized in that: The overall braided structure (I) includes a diamond braided structure, a regular braided structure, or a three-phase braided structure.

3. The graded degradable tracheal stent according to claim 1, characterized in that: The local woven structure (II) includes plain weave, twill weave, satin weave, gauze weave, openwork weave, honeycomb weave, or double-layer weave.

4. The graded degradable tracheal stent according to claim 1, characterized in that: The biodegradable metal wire (1) is made of magnesium, zinc or their alloys.

5. The graded degradable tracheal stent according to claim 1 or 4, characterized in that: The diameter of the biodegradable metal wire (1) is 0.1-0.5 mm.

6. The graded degradable tracheal stent according to claim 1, characterized in that: The biodegradable polymer fiber (2) is made of one of polydioxane, polydioxane, or polylactic acid.

7. The graded degradable tracheal stent according to claim 1 or 6, characterized in that: The diameter of the biodegradable polymer fiber (2) is 0.1-0.5 mm.

8. The graded degradable tracheal stent according to claim 1, characterized in that: The total number of the biodegradable metal wire (1) and the biodegradable polymer fiber (2) is 10 to 500.

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