Delivery system of C-shaped iron-based alloy biodegradable endotracheal stent

Abstract

The present invention provides a delivery system of a C-shaped iron-based alloy degradable endotracheal stent, including a C-shaped mesh endotracheal stent and a stent delivery system; the delivery system includes an outer sheath tube, an inner sheath tube and a core structure; the inner sheath tube is a pipeline structure passing through the inside of the outer sheath tube, including a stent groove, a tail, and an inner sheath tube water injection port, and the stent groove includes a front end and a balloon; the tail is provided with a balloon water injection hole, and the balloon water injection hole is communicated with the inner sheath tube water injection port and the balloon respectively; the core structure includes a guide wire and an inner sheath tube core, the inner sheath tube core is a blocking structure for blocking the inner sheath tube water injection port, and the inner sheath tube core end is provided with a core water injection hole; the guide wire is a metal wire with a soft head at the front end, and the guide wire passes through the inner sheath tube after the inner sheath tube core is pulled out. The present invention degrades quickly in vivo, is firmly fixed, is not easy to shift, and is convenient for positioning.

Description

Technical Field

[0001] The invention relates to the field of organ stent equipment, in particular to a delivery system for a C-shaped iron-based alloy degradable tracheal stent. Background Art

[0002] The trachea is a tube connecting the larynx and the lungs, composed of cartilage, muscle, connective tissue and mucosa; the cartilage is a "C"-shaped cartilage ring with a gap facing backwards. The cartilage rings are connected by ligaments, and the gap behind the ring is connected by smooth muscle and dense connective tissue, maintaining a continuous open state. The most common tracheal malformation is tracheal stenosis, and cardiovascular malformation is one of the reasons for the compression and softening of the trachea. Trauma, endotracheal intubation and other reasons can cause abnormal passages between the trachea or bronchi and the pleural membrane, mediastinum and organs in the mediastinum (such as esophagus, chest, stomach, etc.), that is, partial defects in the trachea, which can cause irritating coughs, repeated lung infections, swallowing and breathing difficulties, and even life-threatening.

[0003] Tracheal stents can be implanted in the body through minimally invasive surgery, which has the advantages of safety, effectiveness and low trauma. After implantation, artificial tracheal stents can continuously expand the airway, block the defect, and immediately improve the patient's pulmonary ventilation function, so that the patient's discomfort symptoms are relieved. Clinically, the treatment of tracheal stenosis in infants and young children is still a difficult problem. At present, there are very few hospitals that can perform primary surgical correction for children with congenital heart disease and tracheal stenosis, and the postoperative recovery is poor. At present, the treatment of tracheal stenosis in children is still a clinical problem. The main reasons are: first, there is a lack of tracheal stent products suitable for children. Adult tracheal stents are not suitable for children, especially infants and young children, due to size and material problems; second, as the cartilage rings of children's trachea grow and develop, the diameter of the stent body cannot increase with the development of the child's trachea, resulting in the width of the stent body being unable to meet the demand. Existing tracheal stents will deform and collapse due to physiological environment or random stimulation (such as coughing) during use, which will cause symptoms such as shortness of breath and dyspnea in patients with implanted stents. Therefore, the support force and anti-displacement ability of the tracheal stent are required to be high. At present, most tracheal stents are straight tubes, and there is still a lot of room for improvement in anti-displacement performance and radial support force. Artificial tracheal stents made of non-degradable materials can cause tracheal stenosis due to long-term retention in the body, or cause damage to the airway when removed. Degradable artificial tracheal stents will gradually degrade over time, thus avoiding the risk of secondary surgery. The application of tracheal stents in clinical practice has achieved good results, and this technology has become an extremely important means of treating patients with inoperable airway stenosis. However, this technology still has a lot of room for development.

[0004] There are many types of stents:

[0005] 1. Silicone stents are more common and cannot shrink like metal stents, making them difficult to place and difficult to integrate into the airway, so they are prone to migration. At the same time, because silicone stents hinder the cleaning function of the airway mucosa, mucus retention will be relatively high.

[0006] 2. Metal stents have good support, large cross-sectional diameter, low stent displacement rate and radiopacity, and the procedure for metal stent implantation is relatively simple. However, non-degradable bare metal stents are highly irritating, resulting in a high risk of granulation tissue formation, making it difficult to recover the metal stent; to avoid granulation proliferation, the outer wall of the stent is often coated to form a covered stent. The use of covered stents will affect the ciliary activity and mucus clearance function of the respiratory tract, thereby causing blockage of airway secretions. At the same time, the displacement rate of the covered stent is high, but after long-term implantation, it is often easier to produce granulation tissue at the upper and lower ends of the covered stent, causing the trachea to narrow again and difficult to remove.

[0007] 3. 3D printed stents. With the development of 3D printing technology, it is now possible to produce patient-specific silicone stents through computed tomography, magnetic resonance imaging, etc. Individualized treatment is better than other stents, but due to material limitations, there are many disadvantages. The main limitation of 3D printed stents is that it usually takes several days to manufacture the stent, and it cannot be extended to emergency patients at present.

[0008] If ordinary stents are placed in the airway for more than 6 months, restenosis is prone to occur. Absorbable stents will degrade over time, avoiding complications caused by stent retention for too long or when removed, thereby reducing the risk of bleeding and infection. For children with tracheomalacia or tracheal stenosis, degradable stents are a more advantageous means. Commonly used degradable stents have a fast degradation rate, insufficient support force, and poor tissue compatibility. In addition, existing stents have the disadvantages of poor shape after release and poor support effect. Summary of the invention

[0009] In order to solve the problems of the prior art, the present invention provides a C-shaped iron-based alloy degradable endotracheal stent delivery system, which degrades quickly in the body, is firmly fixed, not easy to shift, and is easy to position. The C-shaped structure is a 270-degree surround structure, which meets the requirements of the physiological and anatomical structure of the trachea and is conducive to the normal function of the tracheal membranous part.

[0010] The invention provides a delivery system for a C-shaped iron-based alloy degradable endotracheal stent, comprising a C-shaped mesh endotracheal stent and a stent delivery system; the delivery system comprises an outer sheath tube, an inner sheath tube and a tube core structure; the inner sheath tube is a pipeline structure passing through the interior of the outer sheath tube, comprising a stent slot, a tail, and an inner sheath tube water injection port, the stent slot comprises a front end and a balloon, the front end is a tubular silica gel embedded in the inner sheath tube, and the thickness is less than the tail, the balloon is a double-layer, closed plastic tubular structure communicated with the tail, and the length is the same as that of the C-shaped mesh endotracheal stent; the tail is provided with a balloon water injection hole, and the balloon water injection hole is respectively communicated with the inner sheath tube water injection port and the balloon; the tube core structure comprises a guide wire and an inner sheath tube core, the inner sheath tube core is a blocking structure for blocking the inner sheath tube water injection port, and a tube core water injection hole is provided at the end of the inner sheath tube core; the guide wire is a metal wire with a soft head at the front end, and the guide wire passes through the interior of the inner sheath tube after the inner sheath tube core is pulled out.

[0011] As a further improvement, the C-shaped mesh tracheal stent comprises an iron-based alloy matrix and a degradable polyester coated on the inner and outer surfaces of the stent, wherein the degradable polyester covers the surface of the stent in the form of a coating. The iron-based alloy comprises an alloy composed of pure iron and metallic manganese.

[0012] As a further improvement, the C-shaped mesh tracheal stent is a C-shaped structure composed of a diamond-shaped mesh, and the diamond-shaped mesh is woven from a single alloy metal wire.

[0013] Further improvement, the C-shaped structure is a 270-degree surrounding structure, and the diamond-shaped grid structure is a large grid structure. The diameter of the C-shaped mesh tracheal stent ranges from 3mm to 12mm, with 1mm as a step.

[0014] Further improvement, the outer sheath tube includes an outer sheath tube front end and an outer sheath tube tail end, the outer sheath tube front end is a transparent or translucent plastic pipe, the diameter is larger than the contracted mesh tracheal stent, and the outer sheath tube tail end is fixedly connected to the inner sheath tube through a lock structure. The outer sheath tube front end is 50cm long, and a colored scale ring is provided on the outer sheath tube with length marks of 10mm, 20mm, 30mm, 40mm, and 50mm in sequence.

[0015] Further improvement, the locking structure includes a first locking buckle, a second locking buckle and a connecting tube, the connecting tube connects the first locking buckle and the second locking buckle, the first locking buckle matches with the threaded structure of the outer sheath tube through a threaded structure to fix the outer sheath tube, and the second locking buckle is connected to the connecting tube through a threaded structure to fix the inner sheath tube after tightening.

[0016] The present invention mainly cooperates with fiberoptic bronchoscopy and tracheal CT examination, and includes the following steps:

[0017] 1. Determine the location and degree of tracheal stenosis and select the stent diameter and type.

[0018] 2. Use a fiberoptic bronchoscope to check, insert a guide wire along the guide wire hole of the fiberoptic bronchoscope, confirm the insertion depth of the stent with the fiberoptic bronchoscope, retain the guide wire and withdraw the fiberoptic bronchoscope.

[0019] 3. Tighten the second lock of the delivery system, pull out the inner sheath tube core, inject water into the water injection hole of the inner sheath tube, insert the guide wire through the front end of the inner sheath tube, and pass through the tail end of the inner sheath tube to deliver the delivery system into the trachea according to the insertion depth;

[0020] 4. Loosen the second lock, fix the inner sheath so that there is no relative displacement between it and the human body, and withdraw the outer sheath until the stent is released.

[0021] 5. Inject water through the balloon injection hole and maintain positive pressure so that the balloon supports the stent.

[0022] 6. Pump water out of the balloon injection hole and maintain negative pressure, then slowly withdraw from the delivery system.

[0023] 7. Use a fiberoptic bronchoscope to check the status of the stent and its supporting effect.

[0024] The beneficial effects of the present invention are:

[0025] 1. The corrosion rate of pure iron in the in vivo environment is slow, which cannot meet the clinical degradation time requirements for degradable stents, so it is necessary to increase the corrosion rate of iron. From the perspective of clinical application, when the absorbable implantable medical device has completed its intended use, the lesion site has healed and restored its normal morphology and function, the shorter the time for the device to be completely degraded and absorbed by the body, the better, without causing new biocompatibility issues. Depending on the different parts of the device in clinical application, it is generally believed that the healing period is 1-6 months, during which time the device needs to maintain structural integrity and sufficient mechanical properties. Iron-based alloys are used as the matrix material of implantable medical devices, with good biocompatibility, and iron ions help inhibit smooth muscle and promote endothelial cell growth, but iron-based alloys corrode slowly in the body, resulting in iron-based alloy devices still taking a long time to completely corrode after the healing period, so it is necessary to speed up its corrosion rate to shorten the corrosion cycle of iron-based alloys. Studies have shown that coating a degradable polyester coating on the surface of an iron-based alloy can increase its corrosion rate. The degradation of the degradable polyester coating in the body will cause the pH value of the local microenvironment near the device implantation site to decrease, forming a local slightly acidic environment. The iron-based alloy can corrode faster in this acidic environment to generate corrosion products such as iron salts and / or iron oxides and / or iron hydroxides.

[0026] 2. Existing studies have found that bare iron-based stents do not corrode or corrode slowly in animals for a long time, and their complete corrosion cycle may exceed 5 years, which cannot reflect the advantages of bioabsorbable stents. After the introduction of a degradable polymer coating on the surface of the stent, the acidic environment generated by the degradation of the polymer can promote the corrosion of iron, regulate the degradation behavior of the iron stent and shorten the entire degradation cycle. However, immediately after the stent is implanted, the degradable polymer coating begins to swell and hydrolyze, and the iron-based matrix immediately starts to corrode, which may cause the stent to lose effective support prematurely before the vascular remodeling is completed, and then cause restenosis. In order to ensure that the iron-based matrix does not start to corrode within a certain period of time (3 to 6 months) after implantation, so as to provide sufficient mechanical support for vascular repair, a manganese-containing protective layer is also introduced between the iron-based matrix and the degradable polymer layer. In addition, in order to match the degradation cycle of the degradable polymer and the consumption rate of the manganese-containing protective layer with the corrosion cycle of the iron-based matrix, so as to ensure that the iron-based matrix can provide sufficient radial support during the repair period and can corrode quickly after the repair period, the selection of degradable polymers is crucial. Parameters such as the type and molecular weight of the degradable polymer are key parameters affecting the consumption rate of the zinc-containing protector.

[0027] 3. The iron-based alloy stent is a bare stent made of a single alloy metal wire and composed of a rhombus grid structure, wherein the rhombus grid structure is a large grid structure. The bare stent is firmly fixed and not easy to shift.

[0028] 4. C-shaped iron-based alloy biodegradable endotracheal stent, the C-shaped structure is a 270-degree surround structure, which meets the requirements of the physiological and anatomical structure of the trachea and is conducive to the normal function of the tracheal membranous part.

[0029] 5. The inner sheath is equipped with a balloon structure, and the stent is covered on the outside of the balloon. After the stent is released, the balloon is filled with water to quickly shape the stent to the expected diameter.

[0030] 6. The diameter of the stent is serialized in a step-by-step manner, which is convenient for patients, especially children, to choose.

[0031] 7. The stent and the outer sheath of the delivery system are equipped with colored scale rings with length marks of 10mm, 20mm, 30mm, 40mm, 50mm, etc. for easy positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a schematic diagram of the structure of the present invention;

[0034] Figure 2 Schematic diagram of the inner sheath structure;

[0035] Figure 3 This is a schematic diagram of the C-type structure.

[0036] In the figure, an outer sheath 1, an inner sheath 2, a core structure 3, a front end of the outer sheath 4, a rear end of the outer sheath 5, a connecting tube 6, a first locking buckle 7, a second locking buckle 8, a bracket groove 9, a rear end 10, an inner sheath water injection port 11, a front end 12, a balloon 13, a balloon water injection hole 14, a guide wire 15, an inner sheath core 16, and a core water injection hole 17. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] A specific embodiment of the present invention is structured as follows Figure 1 As shown, it includes a C-shaped mesh tracheal stent and a delivery system, and the delivery system includes an outer sheath tube, an inner sheath tube, and a tube core structure.

[0039] The C-shaped mesh tracheal stent comprises an iron-based alloy matrix and a degradable polyester coated on the inner and outer surfaces of the stent, wherein the degradable polyester covers the surface of the stent in the form of a coating. The iron-based alloy comprises an alloy composed of pure iron and metallic manganese.

[0040] The C-shaped structure is a 270-degree surrounding structure. The iron-based alloy stent is a bare stent made of a single alloy metal wire and composed of a diamond grid. The diamond grid structure is a large grid structure. The mesh stent is an iron-based alloy stent, and its diameter ranges from 3mm to 12mm, with 1 mm as a step.

[0041] The degradable polyester coated on the inner and outer surfaces of the stent is polylactic acid.

[0042] The delivery system includes an outer sheath tube 1, an inner sheath tube 2, and a core structure 3. The outer sheath tube includes an outer sheath tube front end 4 and an outer sheath tube tail end 5. The outer sheath tube front end is a transparent or translucent plastic pipe with a length of 50 cm and a diameter of: (the diameter is larger than the contracted stent). The outer sheath tube is provided with a colored scale ring with length marks of 10mm, 20mm, 30mm, 40mm, 50mm, etc. in sequence.

[0043] The tail end of the outer sheath tube includes a first locking buckle 7, a second locking buckle 8, and a connecting tube 6. The connecting tube connects the first locking buckle and the second locking buckle. The first locking buckle matches the threaded structure of the outer sheath tube through a threaded structure to fix the outer sheath tube. The second locking buckle is connected to the connecting tube through a threaded structure and fixes the inner sheath tube after tightening so that the inner and outer sheath tubes will not move relative to each other.

[0044] The inner sheath is as follows Figure 2 As shown, it includes a stent groove 9, a tail 10, and an inner sheath water injection port 11. The inner sheath is a pipeline structure. The inner sheath stent groove includes a front end 12 and a balloon 13. The front end of the inner sheath is a tubular silicone embedded in the inner sheath, with a length of 3mm. The thickness of the front end is smaller than the tail. The length of the balloon is the length of the stent. The balloon is a double-layer, closed plastic tubular structure that communicates with the tail of the inner sheath, with a length of 50cm. The closed structure is connected to the balloon water injection hole at the tail of the inner sheath 14.

[0045] The core structure 3 includes a guide wire 15 and an inner sheath tube core 16. The guide wire is 60 cm long, has a soft head at the front end, and a metal wire at the tail end that can be inserted through the front end of the inner sheath tube after the inner sheath tube core is pulled out. The guide wire is 100 cm long.

[0046] The inner sheath tube core structure is a metal tubular structure, and the end thereof is connected to the tube core water injection hole 17 .

[0047] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A delivery system for a C-shaped iron-based alloy biodegradable endotracheal stent, characterized in that: It comprises a C-shaped mesh tracheal stent and a stent delivery system; the delivery system comprises an outer sheath tube, an inner sheath tube and a tube core structure; the inner sheath tube is a pipeline structure passing through the interior of the outer sheath tube, comprising a stent slot, a tail, and an inner sheath tube water injection port, the stent slot comprises a front end and a balloon, the front end is a tubular silicone embedded in the inner sheath tube, and the thickness is smaller than the tail, the balloon is a double-layer, closed plastic tubular structure communicating with the tail, and the length is the same as that of the C-shaped mesh tracheal stent; the tail is provided with a balloon water injection hole, and the balloon water injection hole is respectively communicated with the inner sheath tube water injection port and the balloon; the tube core structure comprises a guide wire and an inner sheath tube core, the inner sheath tube core is a blocking structure for blocking the inner sheath tube water injection port, and a tube core water injection hole is provided at the end of the inner sheath tube core; the guide wire is a metal wire with a soft head at the front end, and the guide wire passes through the interior of the inner sheath tube after the inner sheath tube core is pulled out.

2. The delivery system of the C-shaped iron-based alloy biodegradable endotracheal stent according to claim 1, characterized in that: The C-shaped mesh tracheal stent comprises an iron-based alloy matrix and a degradable polyester coated on the inner and outer surfaces of the stent, wherein the degradable polyester covers the surface of the stent in the form of a coating.

3. The delivery system of the C-shaped iron-based alloy biodegradable endotracheal stent according to claim 2, characterized in that: The iron-based alloy comprises an alloy consisting of pure iron and metallic manganese.

4. The delivery system of the C-shaped iron-based alloy degradable endotracheal stent according to claim 2 or 3, characterized in that: The C-shaped mesh tracheal stent is a C-shaped structure composed of a rhombus mesh, and the rhombus mesh is woven from a single alloy metal wire.

5. The delivery system of the C-shaped iron-based alloy degradable endotracheal stent according to claim 4, characterized in that: The C-shaped structure is a 270-degree surrounding structure, and the diamond-shaped grid structure is a large grid structure.

6. The delivery system of the C-shaped iron-based alloy biodegradable endotracheal stent according to claim 4, characterized in that: The diameter of the C-shaped mesh tracheal stent ranges from 3 mm to 12 mm, with 1 mm as a step.

7. The delivery system of the C-shaped iron-based alloy biodegradable endotracheal stent according to claim 1, characterized in that: The outer sheath tube comprises an outer sheath tube front end and an outer sheath tube tail end. The outer sheath tube front end is a transparent or translucent plastic pipe with a diameter larger than the contracted mesh tracheal stent. The outer sheath tube tail end is fixedly connected to the inner sheath tube through a locking structure.

8. The delivery system of the C-shaped iron-based alloy degradable endotracheal stent according to claim 7, characterized in that: The front end length of the outer sheath tube is 50 cm, and the outer sheath tube is provided with a colored scale ring with length marks of 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm in sequence.

9. The delivery system of the C-shaped iron-based alloy degradable endotracheal stent according to claim 8, characterized in that: The locking buckle structure includes a first locking buckle, a second locking buckle and a connecting tube. The connecting tube connects the first locking buckle and the second locking buckle. The first locking buckle matches the threaded structure of the outer sheath tube through a threaded structure to fix the outer sheath tube. The second locking buckle is connected to the connecting tube through a threaded structure and fixes the inner sheath tube after tightening.

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