CN215839741U - Blood vessel support system - Google Patents

Abstract

The utility model provides a degradable vascular stent system, which comprises a stent, wherein the stent comprises a stent matrix and a drug coating arranged on the stent matrix, and the stent matrix is made of a biodegradable material; the balloon conveying system conveys the stent to a lesion part, the balloon conveying system comprises a balloon, and the state of connection or separation between the balloon and the stent base body can be realized by changing the states of the balloon and the stent base body. The support among this technical scheme blood vessel support system is made by degradable material and carries on the medicine layer, not only can realize the radial expansion supporting role to blood vessel, but also can release the medicine for a long time, reach the effect to the long-term treatment of injury position, and along with vascular progressively restoreing with perfect, the degradation is also progressively realized to the support, generate human absorbable carbon dioxide and water, avoid the support to remain for a long time in vivo, avoid causing secondary damage such as vascular restenosis or complication.

Description

Blood vessel support system

Technical Field

The utility model belongs to the technical field of medical instruments, and particularly relates to a vascular stent system.

Background

The intravascular stent is characterized in that an internal stent is placed in a lesion section on the basis of the expansion forming of a lumen saccule so as to achieve the purposes of supporting a blood vessel at a stenotic occlusion section, reducing the elastic retraction and reshaping of the blood vessel and keeping the blood flow of a lumen unobstructed. Some stents also have the effect of preventing restenosis. Most of the existing vascular stents are made of medical stainless steel, and along with the gradual repair of vascular functions, the vascular stents made of the medical stainless steel can be stored in the vascular tube for a long time, which easily causes vascular restenosis, vascular wall damage and a series of complications. Particularly, when the blood vessel support is used for treating below-knee diseases, due to the special position below the knee, when a patient moves, the below-knee part can be in a state of frequent stretching or bending, and the stainless steel support staying in the blood vessel for a long time can form repeated friction with the blood vessel under the action of external skin pressure, so that the possibility of complications caused by the in-vivo support is greatly improved. There is a need for a degradable vascular stent, which is gradually degraded along with the gradual repair of blood vessels, so as to prevent the vascular stent from remaining in vivo for a long time and causing secondary injury to patients.

Disclosure of Invention

In order to solve the technical problems, the first aspect of the utility model provides a vascular stent system, which comprises a stent, a drug coating and a drug releasing layer, wherein the stent comprises a stent base body and the drug coating is arranged on the stent base body, and the stent base body is made of a biodegradable material; the balloon conveying system conveys the stent to a lesion part, the balloon conveying system comprises a balloon, and the state of connection or separation between the balloon and the stent base body can be realized by changing the states of the balloon and the stent base body.

As a preferable technical scheme, the in vivo degradation time of the stent matrix is 24-48 months.

As a preferable technical scheme, the material of the stent matrix is selected from at least one of polylactic acid, levorotatory polylactic acid, racemic polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polylactic acid-caprolactone copolymer, polycaprolactone, poly-p-phenylene dioxanone fiber and poly-beta-hydroxybutyric acid.

As a preferable technical scheme, the material of the stent matrix is polylactic acid, the melt flow index of the polylactic acid is 40000-45000g/10min, and the test conditions of the melt flow index are as follows: GB/T3682-.

As a preferable technical scheme, the tensile strength of the polylactic acid is more than or equal to 50MPa, and the test reference standard of the tensile strength is as follows: GB/T1040-.

As a preferable technical scheme, the impact strength of the polylactic acid is more than or equal to 2.0KJ/m2, and the test reference standard of the impact strength is as follows: GB/T1043-.

As a preferable technical proposal, the time for releasing 95wt percent of the drug in the drug coating is more than or equal to 90 days. The polylactic acid has complete biodegradability, and the stent matrix prepared by using the polylactic acid can be gradually degraded within 24-48 months, and finally forms carbon dioxide and water which can be absorbed by human bodies. The polylactic acid has better biocompatibility, air permeability and oxygen permeability, and when the bracket matrix made of the polylactic acid material is taken as an explant to be conveyed into a human body, the human body does not have any rejection reaction, thereby being beneficial to the treatment of the diseases of patients. The stent matrix is coated with the drug coating, the stent matrix is transported to a lesion under the action of the balloon, the stent matrix is expanded at the lesion, so that the purposes of supporting a stenosed occlusive segment blood vessel and keeping blood in the blood vessel smooth are achieved, at the moment, the balloon is separated from the stent matrix through contraction, and the stent matrix is placed at the lesion. However, in the process of transporting the stent matrix by the balloon, a bent bone or a bent blood vessel can be encountered, a certain external stress can be applied to the stent matrix, the pressing and holding firmness of the stent matrix and the balloon stent is reduced, the smoothness of the balloon in transporting the stent matrix is prevented, and the holding force between the stent matrix and the balloon is improved, so that the stent matrix material cannot have too high toughness and elasticity. However, when the stent matrix reaches the lesion site, the stent matrix is completely expanded by inflating and expanding the balloon, and the blood vessel can be supported, and if the toughness and elasticity of the stent matrix are too low, the stent matrix is not completely expanded, which may hinder the separation of the stent matrix and the balloon. The inventor finds that when polylactic acid with the melt flow index of 40000-45000g/10min, the tensile strength of more than or equal to 50MPa and the impact strength of more than or equal to 2.0KJ/m2 is selected, particularly when the polylactic acid with the melt flow index of 42000-43000g/10min is selected, the formed stent matrix has better toughness, moldability and hardness, better moldability during pressing and holding, better holding force between the stent matrix and the balloon, proper toughness and recovery, and complete expansion can be realized when the stent needs to be expanded. And the polylactic acid under the melt flow index has proper molecular weight, so that the medicine coated on the polylactic acid has longer slow release time, the effect of long-time slow release is achieved, and the treatment effect is improved. When the melt flow index of polylactic acid is reduced, the drug slow-release time is further prolonged, but the toughness of the stent matrix is reduced, and complete expansion cannot be realized during expansion. When the melt flow index of the polylactic acid is increased, the mechanical strength of the polylactic acid is reduced, and the stent matrix has no good support property in blood vessels.

As a preferred technical solution, the drug in the drug coating is selected from at least one of rapamycin, sirolimus, tacrolimus, everolimus, leflunomide, M-dehydrocortisol, dexamethasone, cyclosporins, mycophenolic acid, mizoribine, tranilast, zotarolimus, actinomycin, methotrexate, angiostatin, vincristine, mitomycin, statins, and probucol.

As a preferable technical scheme, the medicine in the medicine coating is rapamycin, and the content of the rapamycin instruction on the stent matrix is 10ug/mm 2.

As a preferred technical scheme, the developing mosaic ring is arranged on the support base body, the support base body comprises a plurality of support beams and connecting rods for connecting the support beams, and the support beams are wavy by repeated extension of convex peaks and concave valleys.

As a preferred technical scheme, two ends of the bracket base body are respectively provided with two connected developing embedded rings, developing marks are arranged in the developing embedded rings, and the developing marks are made of platinum alloy.

As a preferable technical scheme, the platinum-based alloy is specifically Pt90/Ir 10.

As a preferable technical scheme, the beam width of the support beams is 0.1-0.3mm, the height difference between adjacent convex peaks and valleys is 0.3-0.8mm, the vertical distance between two adjacent support beams is 0.5-0.9mm, the radian corresponding to the convex peaks is pi/4-5 pi/6, and the radian corresponding to the valleys is pi/4-5 pi/6.

In a preferable technical scheme, the beam width of the support beams is 0.18mm, the height difference between the adjacent convex peaks and the adjacent concave valleys is 0.55mm, the vertical distance between two adjacent support beams is 0.7mm, the radian corresponding to the convex peaks is 2 pi/5, and the radian corresponding to the concave valleys is 2 pi/5. The structure of the stent base body has very important significance for the pressing and holding process, the smoothness of transportation in the blood vessel, the support property and the support strength of the blood vessel. In order to achieve better supporting strength, the inventor expands the beam width of the supporting beam as much as possible, but the expansion of the beam width reduces the grippability of the stent matrix, reduces the firmness and the holding force of the stent matrix on the balloon, and makes the stent matrix difficult to be delivered to a lesion. A certain gap is kept between two adjacent supporting beams of the stent base body, on one hand, the air permeability of a blood vessel at a lesion part is ensured, on the other hand, the circulation of blood in the stent is ensured, and the situation that the blood vessel at the lesion part is restenosis is prevented. Too large gaps between the support beams can reduce the pressure bearing capacity and the mechanical strength of the support matrix, and too small gaps can hinder the blood circulation in the support. When the support beam is arranged in a wave shape with convex peaks and concave valleys, better press-holding formability can be kept between the support frame and the balloon, better holding force can be obtained, and the flowing resistance of the stent base body in a blood vessel can be increased. The inventor finds in continuous design research that when the beam width of the support beams is 0.18mm, the height difference between the adjacent peaks and the valleys is 0.55mm, the vertical distance between two adjacent support beams is 0.7mm, the radian corresponding to the peaks is 2 pi/5, and the radian corresponding to the valleys is 2 pi/5, the stent base has good support strength, the lowest delivery resistance, the blood vessel at the lesion has good air permeability, the stent base has good pressure-holding force when being pressed against the balloon, and when the stent base is expanded, uniform expansion of the stent can be achieved.

As a preferred aspect, the balloon delivery system further comprises a tip attached to the distal end of the balloon; the inner tube penetrates through the middle of the balloon, the far end of the inner tube is fixedly connected with the far end of the balloon, the inner tube sequentially comprises an inner layer, a woven layer and an outer layer which are fixedly connected from inside to outside, a guide wire passes through the inner tube, and developing rings are arranged at the far end and the near end of the balloon of the inner tube; an outer tube comprising a distal outer tube, a proximal outer tube connected to the distal outer tube, a length ratio between the distal outer tube and the proximal outer tube being in the range of 1: (3-5), the inner tube is sleeved inside the outer tube, when the inner tube is arranged in the balloon, the far end of the inner tube extends out of the far end of the far outer tube and is connected with the far end of the balloon, the outer side of the far outer tube is coated with a hydrophilic coating, the far end of the far outer tube is fixedly connected with the near end of the balloon, and a pressure channel is formed among the outer tube, the inner tube and the balloon to realize compression and expansion of the balloon; the near ends of the near outer pipe and the near ends of the near inner pipe are sleeved in the stress supporting pipe; the handle is connected with one end of the stress supporting tube far away from the outer tube, and the handle is fixedly connected with the inner tube and the outer tube; the balloon is provided with a reserved crease which is formed by pressing and holding the bracket.

As a preferred technical scheme, the material of the tip is polyether block polyamide.

As a preferred embodiment, the polyether block polyamide of the tip material has a Shore hardness of 50 to 55D.

As a preferred technical solution, the material of the balloon is selected from at least one of nylon, polyethylene, polypropylene and polyether copper.

As a preferred technical solution, the material of the balloon is nylon, more specifically PA 12.

As a preferable technical scheme, the inner layer of the inner pipe is divided into an A section, a B section and a C section from the proximal end to the distal end in the length direction, the Shore hardness of the raw materials used for the A section is 70-75D, the Shore hardness of the raw materials used for the B section is 66-72D, the Shore hardness of the raw materials used for the C section is 50-55D, and the length ratio of the A section, the B section and the C section is (10-15): (1-3): (0.8-2).

As a preferred solution, the inner layer of the inner tube has a thickness of 0.0004 to 0.0006 inches.

As a preferable technical scheme, the material of the section A of the inner layer of the inner pipe is nylon, more specifically PA12, and the Shore hardness of the PA12 is 70-75D, which is obtained by referring to ASTM D2240 test standard.

As a preferable technical scheme, the material of the section B of the inner layer of the inner pipe is polyether block polyamide, and the Shore hardness of the polyether block polyamide is 66-72D, and is obtained by referring to ASTM D2240 test standard.

As a preferable technical scheme, the material of the section C of the inner layer of the inner pipe is polyether block polyamide, and the Shore hardness of the polyether block polyamide is 50-55D and is obtained by referring to ASTM D2240 test standard. The inner layer of the inner tube has a supporting function for the balloon to smoothly pass through the blood vessel to reach a lesion part, so the material of the inner layer of the inner tube needs to have certain mechanical strength, but the inventor finds that if the mechanical strength of the inner tube is too high, the blood vessel or the lesion part can be greatly impacted, unnecessary injury is easily brought to the blood vessel, and when the mechanical strength of the inner layer of the inner tube is low, a good force transmission effect cannot be achieved. The inventor finds that the nylon PA12 and polyether block polyamide with different mechanical strength are connected to form the inner layer of the inner pipe with mechanical strength transition and transition properties, namely the mechanical strength and hardness of the inner layer of the inner pipe are gradually reduced from the near end to the far end, so that the force transmission and support effects of the inner pipe can be ensured, and the inner pipe does not have large impact on blood vessels.

As a preferred technical solution, the material of the braided layer of the inner tube is stainless steel.

As a preferred technical solution, the material of the braided layer of the inner tube is 304V stainless steel.

As a preferred solution, the thickness of the braided layer of the inner tube is between 0.001 inch and 0.003 inch.

As a preferable technical scheme, the material of the outer layer of the inner pipe is polytetrafluoroethylene. As a preferred embodiment, the outer layer of the inner tube has a thickness of 0.02 to 0.03 inches.

As a preferred technical scheme, the friction coefficient of the hydrophilic coating is 0.01-0.02.

As a preferred technical scheme, the thickness of the hydrophilic coating is 3-5 um.

As a preferable technical scheme, the material of the hydrophilic coating is polyvinylpyrrolidone.

As a preferable technical scheme, the number average molecular weight of the polyvinylpyrrolidone is 300000-400000.

As a preferable technical scheme, the number average molecular weight of the polyvinylpyrrolidone is 320000-380000. The inventor begins to select polyvinylpyrrolidone with a larger molecular weight as the hydrophilic coating in order to improve the flexibility of the hydrophilic coating, but the inventor finds that when polyvinylpyrrolidone with a larger molecular weight is selected as the hydrophilic coating, the friction between the hydrophilic coating and the body is improved, and the patient feels pain. In the later period, the inventor artificially relieves the pain of patients, and selects polyvinylpyrrolidone with smaller molecular weight as the hydrophilic coating, but the inventor finds that the hydrophilic coating has poorer durability, the hydrophilic coating is easy to crack and fall off on the far outer tube, the acting force between the hydrophilic coating and the far outer tube is smaller, and the polyvinylpyrrolidone can not be firmly molded on the far outer tube. The inventor unexpectedly finds that the polyvinylpyrrolidone with the molecular weight of 320000-.

The second aspect of the utility model provides a preparation method of the vascular stent system, which at least comprises the following steps: a: preparing a bracket; b: preparing a balloon transportation system; c: the stent is crimped onto the balloon of the balloon delivery system.

Has the advantages that:

(1) the support among this technical scheme blood vessel support system is made by degradable material and carries on the medicine layer, not only can realize the radial expansion supporting role to blood vessel, but also can release the medicine for a long time, reach the effect to the long-term treatment of injury position, and along with vascular progressively restoreing with perfect, the support also progressively realizes the degradation, generate human absorbable carbon dioxide and water, avoid the support to remain for a long time in vivo, avoid causing secondary damage such as vascular restenosis or complication, especially when being used for treatment under the knee, better treatment has. (2) According to the technical scheme, the inventor reasonably designs the support structure and selects the support material, so that the support has good support strength and the lowest conveying resistance, the blood vessel at the lesion position has good air permeability, the support base body and the balloon are pressed and held with good pressing and holding force, and when the support base body expands, the support can be uniformly expanded. (3) In the technical scheme, the inventor selects materials and structurally designs the balloon, the inner tube and the outer tube, so that the balloon has better contraction and expansion states, the inner tube and the outer tube have more proper supporting force and softness, the force transmission can be realized, and the intervention feeling of a patient can be relieved to the greatest extent.

Drawings

Fig. 1 is a schematic view of the entire structure of the stent system in example 1.

Fig. 2 is a schematic view of the deployed structure of the vascular stent in example 1.

Fig. 3 is a schematic sectional structure of the inner tube.

1-tip, 2-saccule, 3-developing ring, 4-stent base body, 5-inner tube, 6-far outer tube, 7-near outer tube, 8-stress supporting tube, 9-handle, 10-hydrophilic coating, 11-developing embedded ring, 12-convex peak, 13-concave valley, 14-supporting beam, 15-connecting rod, 16-inner layer, 17-woven layer and 18-outer layer.

Detailed Description

Example 1

As shown in figure 1, the blood vessel stent system comprises a stent and a balloon conveying system for conveying the stent to a lesion, wherein the balloon conveying system comprises a balloon 2, and the stent can be conveyed to the lesion and separated from the stent by changing the contraction and expansion states of the balloon 2. The stent comprises a stent matrix 4 and a drug coating arranged on the stent matrix 4, wherein the stent matrix is made of biodegradable materials, and the specification specifically refers to polylactic acid. The in vivo degradation time of the stent matrix 4 in this embodiment is 24-48 months, and the degradation time may vary depending on the physical condition of the patient. The melt flow index of the polylactic acid described in this example is 42045g/10min, and the test conditions of the melt flow index are as follows: GB/T3682-. The tensile strength of the polylactic acid is more than or equal to 50MPa, and the test reference standard of the tensile strength is as follows: GB/T1040-. The impact strength of the polylactic acid is more than or equal to 2.0KJ/m2, and the test reference standard of the impact strength is as follows: GB/T1043-1992, the glass transition temperature of the polylactic acid is 57-60 ℃, and the mark of the polylactic acid is marine organism REVODE 101. The drug in the drug coating in this example is rapamycin, the content of rapamycin on the stent substrate is 10ug/mm2, the drug coating is rapamycin dissolved in tetrahydrofuran, then the rapamycin is sprayed on the stent substrate by ultrasound, and cured in air for 35min, then the procedure is repeated until the content of rapamycin on the stent substrate is 10ug/mm2, and finally the stent substrate coated with the drug coating is placed in a vacuum oven at 40 ℃ for drying for 1 h. In this example, the time for releasing 95 wt% of the drug in the drug coating is greater than or equal to 90 days. As shown in fig. 2, two ends of the bracket base 4 in this embodiment are respectively provided with two connected developing embedded rings 11, developing marks are provided in the developing embedded rings 11, positions of products are located through an X-ray machine and the developing marks, the developing marks are platinum, the bracket base 4 includes a plurality of supporting beams 14 and connecting rods 15 connecting the supporting beams 14, the supporting beams 14 are wavy and formed by repeatedly extending peaks 12 and valleys 13, a beam width of each supporting beam 14 is 0.18mm, a height difference between adjacent peaks 12 and valleys 13 is 0.55mm, a vertical distance between two adjacent supporting beams 14 is 0.7mm, a radian corresponding to a peak 12 is 2 pi/5, and a radian corresponding to a valley 13 is 2 pi/5. The stent basal body 4 of this design has better support intensity, the lowest transport resistance, and the blood vessel of pathological change department has better gas permeability, and when stent basal body 4 and sacculus 2 were pressed and are held, has better pressure and hold the holding power, and when the stent basal body expansion, can realize the even expansion of support. The balloon transportation system further comprises a tip 1, wherein the tip 1 is connected to the distal end of the balloon 2 and is used for guiding the balloon 2; as shown in fig. 3, the inner tube 5 penetrates through the middle of the balloon 2, the distal end of the inner tube 5 is fixedly connected with the distal end of the balloon 2, the inner tube 5 sequentially comprises an inner layer 16, a braided layer 17 and an outer layer 18 which are fixedly connected from inside to outside, a guide wire passes through the inner tube 5, the size of the guide wire is 0.014 inch, developing rings 3 are arranged at the distal end and the proximal end of the inner tube 5, and the developing rings are made of Pt90/Ir 10; an outer tube comprising a distal outer tube 6, a proximal outer tube 7 connected to the distal outer tube 6, the length ratio between the distal outer tube and the proximal outer tube being in the range of 1: 4, the outer tube is made of PA12, the inner tube is sleeved inside the outer tube specification, when in the balloon, the far end of the inner tube 5 extends out of the far end of the outer tube and is connected with the far end of the balloon, the outer side of the far outer tube 6 is coated with a hydrophilic coating 10, the far end of the far outer tube 6 is fixedly connected with the near end of the balloon 2, a pressure channel is formed among the outer tube 6, the inner tube 5 and the balloon 2, and the compression and expansion of the balloon 2 are realized by inflating or deflating the pressure channel; the stress support tube 8 is sleeved at the near ends of the near outer tube 7 and the inner tube 5, the connection part of the outer tube and the inner tube 5 with the handle 9 can be prevented from being broken due to the arrangement of the stress support tube 8, the stress support tube 8 is made of polyether block polyamide, and the polyether block polyamide is Pebax 5533; the handle 9 is connected with one end of the stress support tube 8 far away from the outer tube 7, and the handle 9 is fixedly connected with the inner tube 5 and the outer tube; and a reserved crease which is formed by pressing and holding the bracket is arranged on the balloon 2. The handle is made of polycarbonate. The material of the tip is polyether block polyamide, the Shore hardness of the polyether block polyamide of the tip material is 54D, and the Shore hardness is measured according to the standard test of ASTM D2240, and the specific mark is Pebax 5533. The material of the balloon is nylon, more specifically PA12, the inner layer 16 of the inner tube 5 is divided into a section A, a section B and a section C from the proximal end to the distal end in the length direction, the Shore hardness of the raw material used for the section A is 72D, the Shore hardness of the raw material used for the section B is 69D, the Shore hardness of the raw material used for the section C is 54D, and the length ratio of the section A, the section B and the section C is 11.5: 1.7: 1.1. the inner layer 16 of the inner tube 5 has a thickness of 0.0004 inches. The material of the section A of the inner layer of the inner pipe is nylon, more specifically is PA12, the Shore hardness of the PA12 is 72D, and the grade of the PA12 is as follows: swiss EMS TR90, obtained with reference to ASTM D2240 test standard. The material of the section B of the inner layer of the inner pipe 5 is polyether block polyamide, the Shore hardness of the polyether block polyamide is 69D, the Shore hardness is obtained by referring to ASTM D2240 test standard, and the grade of the polyether block polyamide is Pebax 7233. The material of the section C of the inner layer of the inner pipe is polyether block polyamide, the Shore hardness of the polyether block polyamide is 54D, the Shore hardness is obtained by referring to ASTM D2240 test standard, and the grade of the polyether block polyamide is Pebax 5533. The braided layer 17 of the inner tube 5 is made of stainless steel, specifically 304V stainless steel, and the thickness of the braided layer of the inner tube is 0.001 inch. The outer layer of the inner pipe is made of polytetrafluoroethylene, and the thickness of the outer layer of the inner pipe is 0.023 inches. The hydrophilic coating has an average coefficient of friction of 0.0127. The thickness of the hydrophilic coating is 4um, the material of the hydrophilic coating is polyvinylpyrrolidone, the number average molecular weight of the polyvinylpyrrolidone is 320000-: 9003-39-8. And dissolving polyvinylpyrrolidone in water, and spraying the solution on the far-infrared tube in a spraying manner. When the blood vessel stent system is used, the saccule which is pressed and held with the stent is conveyed to a lesion position along a path of a guide wire, when the stent and the saccule reach the lesion position, the saccule is inflated to reach an expanded state, the stent which is pressed and held on the saccule is changed from a bending pressing and holding state to an expansion state, when the stent is expanded to a certain state, after a blood vessel at the lesion position is expanded and expanded, the saccule is contracted through deflation, the saccule is extracted from the body, and the stent is kept at the lesion position.

In a second aspect of this embodiment, there is provided a method for preparing the vascular stent system, comprising the steps of: a: preparing a scaffold, wherein the preparation of the scaffold comprises the following steps; (1) cutting the base material to form the size of the required bracket matrix, and then cleaning, disinfecting and sterilizing; (2) impressing developing points on a developing ring of the support substrate; (3) spraying rapamycin solution on the stent matrix with the imprinted development points to form a drug coating, and drying for later use. B: preparing a balloon transportation system; (1) forming a cylindrical balloon by using PA12 and a forming die, and butting a tip at the far end of the balloon; (2) welding an outer tube at the proximal end of the balloon; (3) welding the inner tube with the far end of the balloon, respectively arranging developing rings at the two ends of the inner tube in the balloon, and welding a tip at the far end of the balloon; (4) marking, cleaning and disinfecting a handle with a stress supporting tube, and bonding an inner tube and an outer tube on the handle; (5) the balloon is provided with a reserved crease, wherein the specific preparation method of the balloon transportation system is carried out by referring to the method in the utility model patent with the patent application number of CN 201310029870.7. C: crimping the stent onto the balloon of the balloon delivery system, wherein the crimping is performed in a specific manner, as described in patent application No. 201380057836.9. Performance test the stent of example 1 was placed in pbs buffer and shaken in a 37 ℃ water bath to observe the complete degradation of the stent for 24 months and the distal outer tube coated with a hydrophilic coating was subjected to a friction coefficient test using an automatic medical catheter friction coefficient tester (LC671-S-F) having a gauge length of 100mm, a speed of 20mm/S, a target clamping force value of 300gf, and a cycle test number of 25 times. The hydrophilic coating in test example 1 had an average coefficient of friction of 0.0127.

Claims (10)

1. A vascular stent system is characterized by comprising a stent, wherein the stent comprises a stent matrix and a drug coating arranged on the stent matrix, and the stent matrix is made of biodegradable materials; the balloon conveying system conveys the stent to a lesion part, the balloon conveying system comprises a balloon, and the state of connection or separation between the balloon and the stent base body can be realized by changing the states of the balloon and the stent base body.

2. The stent system according to claim 1, wherein the stent base has a development inlay ring thereon, and the stent base comprises a plurality of support beams, and a connection rod connecting the support beams, and the support beams have a wave shape formed by repeated extensions of peaks and valleys.

3. A vascular stent system as claimed in claim 2, wherein the peaks correspond to an arc of Π/4-5 Π/6 and the valleys correspond to an arc of Π/4-5 Π/6.

4. A vascular stent system as in claim 2, wherein the support beam has a beam width of 0.1-0.3 mm.

5. The vascular stent system according to claim 2, wherein the height difference between the adjacent crests and valleys is 0.3-0.8 mm.

6. Vessel support system according to claim 2, wherein the vertical distance between two support beams adjacent to each other is between 0.5-0.9 mm.

7. The vascular stent system of any of claims 1-6, wherein the balloon delivery system further comprises a tip attached to a distal end of the balloon; the inner tube penetrates through the middle of the balloon, the far end of the inner tube is fixedly connected with the far end of the balloon, a guide wire passes through the inner tube, and developing rings are arranged at the far end and the near end of the balloon in the inner tube; an outer tube comprising a distal outer tube, a proximal outer tube connected to the distal outer tube, a length ratio between the distal outer tube and the proximal outer tube being in the range of 1: (3-5), the inner tube is sleeved inside the outer tube, when the inner tube is arranged in the balloon, the far end of the inner tube extends out of the far end of the far outer tube and is connected with the far end of the balloon, the far end of the far outer tube is fixedly connected with the near end of the balloon, and a pressure channel is formed among the outer tube, the inner tube and the balloon to realize compression and expansion of the balloon; the near ends of the near outer pipe and the near ends of the near inner pipe are sleeved in the stress supporting pipe; the handle is connected with one end of the stress supporting tube far away from the outer tube, and the handle is fixedly connected with the inner tube and the outer tube; the balloon is provided with a reserved crease which is formed by pressing and holding the bracket.

8. The vascular stent system according to claim 7, wherein the inner tube comprises an inner layer, a woven layer and an outer layer which are fixedly connected in sequence from inside to outside.

9. The vascular stent system according to claim 8, wherein the woven layer is made of stainless steel.

10. The vascular stent system according to claim 7, wherein the outside of the distal outer tube is coated with a hydrophilic coating.

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