Self-lubricating intravascular catheter conveying system

Abstract

The self-lubricating intravascular catheter conveying system comprises a catheter sheath, a conveying sheath and an implanting sheath, at least one of the catheter sheath, the conveying sheath and the implanting sheath is provided with a self-lubricating intravascular catheter structure, and the self-lubricating intravascular catheter structure is characterized in that the outer side of a catheter body is coated with a lubricating layer with the friction coefficient lower than that of the surface of the catheter body; the lubricating layer is a compact smooth layer formed by wrapping the silk thread structure on the outer side of the catheter body in a weaving or winding mode. Compared with a traditional hydrophilic coating manufacturing process, the manufacturing process is more stable and reliable, the problem of catheter deformation caused by leveling property and thermocuring of the coating can be effectively avoided, and the polymer silk thread material is more stable in the aspect of adhesive force durability. Especially, bending control of the catheter cannot be affected, wrinkles cannot be generated at the inner bending position of the catheter, the torque performance from the near end to the far end of the catheter is prevented from being affected, and the macromolecule silk thread material is more reliable in extreme dynamic mechanical stress and complex biological environments.

Description

Technical Field

[0001] This invention belongs to the field of cardiovascular interventional medical device technology, specifically a self-lubricating intravascular catheter delivery system. Background Technology

[0002] Medical catheters are used in minimally invasive interventional diagnostic and therapeutic surgeries to establish access, deliver or retrieve instruments, and deliver drugs. In interventional clinical surgeries, due to the need for excessively long and tortuous vascular pathways (such as the aortic arch and intracranial vessels), the surface materials of current catheters have a high coefficient of friction. When inserting into blood vessels or pushing multiple catheters together, the force is large and can easily cause vascular damage. Therefore, it is necessary to treat the catheter surface to reduce friction.

[0003] Existing methods for reducing surface friction in catheters mainly involve applying a hydrophilic coating to the catheter surface (such as...). Figure 1 As shown), common coating types include PVP coatings, polysaccharide-based coatings, zwitterionic polymer coatings, and composite functional coatings. Coating methods include... (1) Dip-coating lifting method: The conduit is immersed in the solution, the speed is controlled and the conduit is lifted and then cured by ultraviolet light. It has the following disadvantages: the operation is simple but the cost is high, but the process stability is difficult to control and the thickness uniformity is poor. (2) Thermosetting method: The hydrophilic prepolymer containing active groups or thermosetting monomers is applied to the conduit substrate by dip coating, spraying or brushing, and cured by maintaining a specific temperature of 80-150℃ for a specific time. It has the following advantages and disadvantages: the process is mature and sufficient heat makes the coating melt and flow, reducing surface defects, but above 50℃, it will cause deformation at the weak point of the conduit tip.

[0004] Furthermore, the hydrophilic coating has the following drawbacks in the current operation: (1) The coating has poor adhesion and durability. Specifically, under repeated friction, bending, wrinkling and torsional loads, the coating is very easy to peel off from the catheter substrate, crack and blister. The peeled fragments have a very high risk of becoming a source of embolism (especially in cerebrovascular diseases). (2) Insufficient abrasion resistance: The strength of the coating decreases significantly after absorbing water (water plasticization effect) and the abrasion resistance decreases sharply. Repeated insertion and withdrawal of guidewires and catheters and friction with the blood vessel wall cause the coating to wear down rapidly, become thinner or even wear through, resulting in a rapid decrease in lubricity, increasing surgical resistance and the risk of vascular injury (spasm, perforation, dissection). (3) Poor sterilization tolerance and storage aging: Commonly used ethylene oxide sterilization residues and radiation sterilization (gamma rays, electron beams) can easily lead to hydrophilic polymer chain breakage, cross-linking, discoloration, and performance degradation (decreased lubricity and increased brittleness). During storage (dry state), the coating may undergo physical aging (such as cracking due to changes in crystallinity) or chemical changes (oxidation) due to changes in environmental humidity and temperature, affecting the hydration and lubricity during use.

[0005] In particular, the delivery system of multi-layer catheter using hydrophilic coating (the precise arrival of complex path is achieved by combining multiple catheters), such as the demand of structural heart (such as Figure 4 As shown, multiple catheters are nested in blood vessels, and the friction between the tube walls increases exponentially (especially in curved blood vessel segments such as Figure 5 、 Figure 6 As shown, the bending force is large, the internal catheter pushing and rotating is delayed, the implant action response is inconsistent with the handle end (as shown in Figure 8 ), which affects the precision of intraoperative operation, and the doctor needs to adjust the catheter form multiple times to increase the intraoperative time. If a hydrophilic coating is used, it will be scraped off between the catheters due to poor wear resistance.

[0006] After searching, the Chinese utility model patent: self-lubricating antibacterial medical catheter (publication number: CN202909253U, publication date: 2013.05.01), the application discloses a self-lubricating antibacterial medical catheter, which comprises an antibacterial tubular body and a lubricating layer formed on the outer side of the antibacterial tubular body. The lubricating layer is a hydrophilic polymer coating. The lubricating layer of the application adopts a hydrophilic polymer coating, which also has the above problems.

[0007] In addition, the Chinese invention patent: catheter for intravascular blood pump (publication number: CN113195039A , publication date: 2021.07.30), the application discloses an intravascular blood pump, comprising a catheter and a pumping device attached to the distal end of the catheter. The blood pump is pushed through the blood vessels of the patient by means of the catheter. The catheter has an elongated tube body and a porous three-dimensional structure, which is arranged on at least a part of the outer surface of the tube body to promote the adsorption of proteins and the formation of autografts, thereby preventing the growth of the catheter into the blood vessel wall. The porous three-dimensional structure can be formed into a textile sleeve, preferably made of warp knitting fabric. However, the core of this scheme is to promote the growth of biological tissue by using the "porosity" of the material, and the structure is loose, which not only cannot effectively reduce the mechanical friction between the catheters, but also may increase the frictional resistance due to the rough surface, especially when the catheter is nested in the delivery system, the friction between the multiple catheters is greatly increased, thereby affecting the precision of intraoperative operation. SUMMARY

[0008] To achieve the above object, the technical scheme provided by the application is: The self-lubricating intravascular catheter delivery system of the present application comprises a catheter sheath, a delivery sheath and an implant sheath, at least one of the catheter sheath, the delivery sheath and the implant sheath is provided with a self-lubricating intravascular catheter structure, the self-lubricating intravascular catheter structure is a lubricating layer with a lower friction coefficient than the surface of the catheter body coated on the outside of the catheter body, the lubricating layer is a dense smooth layer formed by coating a wire structure on the outside of the catheter body in a weaving or winding manner, Preferably, the friction coefficient of the material used in the lubricating layer is 0.03-0.15.

[0009] Preferably, the lubricating layer is formed of one wire structure material or a mixture of two or more wire structure materials.

[0010] Preferably, the diameter of the wire structure is 3%-8% of the wall thickness of the catheter body.

[0011] Preferably, the catheter body is provided with a groove for embedding and fixing the end face of the lubricating layer.

[0012] Preferably, the weaving density of the lubricating layer during weaving is PPI, and PPI is 90-150.

[0013] Preferably, the number of layers of the lubricating layer is at least one layer.

[0014] Preferably, the embedding and fixing of the groove with the end face of the lubricating layer is specifically locking and fixing the end face of the lubricating layer in the groove along the groove with a locking assembly.

[0015] Preferably, the groove is also filled with a filler to make the groove flush with the surface of the catheter body.

[0016] Preferably, the reserved depth of the groove is 20-80% of the wall thickness of the catheter body.

[0017] Preferably, the width of the groove is 2-4mm.

[0018] Preferably, the implant sheath is provided with a self-lubricating intravascular catheter structure.

[0019] Preferably, the implant sheath and the delivery sheath are provided with a self-lubricating intravascular catheter structure.

[0020] Preferably, the catheter sheath, the delivery sheath and the implant sheath are all provided with a self-lubricating intravascular catheter structure.

[0021] Preferably, the lubricating layer is arranged on the surface of the catheter sheath, the delivery sheath and the implant sheath in contact with each other.

[0022] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects: The self-lubricating intravascular catheter delivery system of the present application comprises a catheter sheath, a delivery sheath and an implant sheath, at least one of which is provided with a self-lubricating intravascular catheter structure, which is a lubricating layer with a lower friction coefficient than the surface of the catheter body coated on the outside of the catheter body; the lubricating layer is a dense smooth layer formed by coating a wire structure on the outside of the catheter body in a braided or coiled manner. Compared with the traditional hydrophilic coating manufacturing process, it is more stable and reliable, can effectively avoid the problems of coating leveling and catheter deformation caused by heat curing, and the adhesion durability of the high molecular wire material is more stable. In particular, it does not affect the bending control of the catheter, and the inner bending part of the catheter bending control does not produce wrinkles to avoid affecting the torque performance from the proximal end to the distal end of the catheter, and the high molecular wire material is more reliable in extreme dynamic mechanical stress and complex biological environment. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Structure diagram of adding hydrophilic coating in the prior art; Figure 2 Structure diagram of a self-lubricating intravascular catheter structure in a self-lubricating intravascular catheter delivery system of Example 1; Figure 3 Structure diagram of a self-lubricating intravascular catheter structure in a self-lubricating intravascular catheter delivery system of Example 2; Figure 4 Clinical intraoperative application diagram of a delivery system of a multi-layer catheter using a hydrophilic coating in the prior art; Figure 5 Bending state diagram of a delivery system of a multi-layer catheter using a hydrophilic coating in the prior art; Figure 6 Catheter space angle form diagram in the prior art; Figure 7 Structure diagram of a self-lubricating intravascular catheter delivery system of Examples 1 and 2; Figure 8 Use state diagram of a delivery system of a multi-layer catheter using a hydrophilic coating in the prior art.

[0024] Explanation of reference numerals in the diagram: 100, catheter body; 110, groove; 200, coiled spring layer; 210, locking assembly one; 300, braided layer; 310, locking assembly two; 400, implant sheath; 500, catheter sheath; 600, delivery sheath. DETAILED DESCRIPTION

[0025] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0026] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0028] In addition, in addition to being used to indicate the orientation or positional relationship, the above-mentioned partial terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain attachment relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0029] In addition, the terms "mount", "set", "provided with", "connected", "connected", "sleeved" should be broadly understood. For example, it can be a fixed connection, a detachable connection, or a monolithic structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Embodiment 1

[0032] Referring to the accompanying drawings Figure 7 A self-lubricating intravascular catheter delivery system includes a catheter sheath 500, a delivery sheath 600 and an implant sheath 400, at least one of which is provided with a self-lubricating intravascular catheter structure, which is a lubricating layer with a lower friction coefficient than the surface of the catheter body 100 coated on the outside of the catheter body 100. The lubricating layer is a smooth and dense solid polymer layer formed by coating a wire structure on the outside of the catheter body 100 in a woven or wire-wound manner, which has a lower friction coefficient than the surface of the catheter body 100, and is used to reduce the friction between the catheter and other sheaths when moving relative to each other inside the delivery system. In this embodiment, the wire-wound layer 200 is formed in a wire-wound manner, and the lubricating layer is formed by coating a wire structure on the outside of the catheter body 100 in a woven or wire-wound manner. Figure 2 The wire-wound layer 200 formed in a wire-wound manner is the lubricating layer, and the material used in the lubricating layer has a friction coefficient of 0.03-0.15. It can be ultra-high molecular weight polyethylene, polytetrafluoroethylene or Pom, etc.

[0033] The lubricating layer is formed by a wire structure material or a mixture of two or more wire structure materials. The wire structure can be round wire or flat wire, etc. The surface of the catheter body 100 is formed with a low-friction woven layer, so that the catheter body 100 has a lubricating effect. Moreover, compared with the traditional hydrophilic coating process, it is more stable and reliable, and can effectively avoid the problems of coating leveling and catheter deformation caused by heat curing. The adhesion durability of the high molecular wire material is more stable. In particular, it does not affect the bending control of the catheter, and does not produce wrinkles at the inner bending of the catheter bending control, which affects the torque performance from the proximal end to the distal end of the catheter. Compared with the hydrophilic coating of the combined substance, the high molecular wire material is more reliable in extreme dynamic mechanical stress and complex biological environment. The present application constructs a dense and smooth wire lubricating layer, which not only overcomes the defects of the traditional hydrophilic coating, but also fundamentally opposes the porous structure growth scheme in the background technology. The present application aims to create a mechanical lubrication interface, actively avoid biological adhesion and tissue growth, and achieve extremely low friction coefficient, excellent wear resistance, stable and durable lubrication effect and precise torque transmission in a complex and tortuous vascular path and multi-layer catheter system, which cannot be achieved by surface porous woven structure or hydrophilic coating.

[0034] The diameter of the wire structure of the embodiment is 3% to 8% of the wall thickness of the catheter body 100. The overall catheter wall thickness, bending performance, braided lubricating layer effect and strength can be effectively guaranteed to meet the requirements. When less than 3%, the formed lubricating layer is too thin, and the lubricating effect and strength are poor. When greater than 8%, the overall wall thickness is increased, the bending performance is affected, and the use difficulty is increased.

[0035] The wire structure covering method is two kinds: spring winding type and braiding type. The spring winding type: the wire diameter is greater than or equal to 0.04 mm, which guarantees the braiding machine covering strength and wear resistance performance, and the number of strands is greater than or equal to 2, the PPI calculation formula is PPI = 1 foot / strand * wire diameter + 0.01. The braiding type: adopts a diamond structure braiding form, the number of single-strand wire is 3-10, and the PPI is 60-150. According to the above parameters in this interval, the braiding density makes the wires tightly combined, and guarantees the dense lubricating property of the outer layer of the catheter.

[0036] The number of layers of the lubricating layer is at least one layer, and can be set to two or more layers according to the requirements of the use environment or performance requirements.

[0037] In the process of braiding the lubricating layer, the braiding density is PPI, and the PPI is 90-150. This interval of braiding density guarantees that the wires are tightly combined to achieve the best lubricating effect.

[0038] Specifically, the catheter body 100 is provided with a groove 110, and the groove 110 is used to embed and fix the end face of the lubricating layer. The end face of the lubricating layer is specifically the cut-off face formed by the two side end wires of the lubricating layer. The embedding and fixing of the groove 110 and the end face of the lubricating layer is specifically that the end face of the lubricating layer is locked and fixed in the groove 110 along the groove 110 by a locking assembly one 210. The groove 110 is also filled with a filler to make the groove 110 flush with the surface of the catheter body 100. By arranging the groove 110 along the annular catheter body 100, placing the end face of the lubricating layer in the groove 110 and fixing it by the locking assembly one 210, the end face of the lubricating layer is prevented from spreading apart, thereby preventing a gap between the lubricating layer and the surface of the catheter body 100. The lubricating layer can be effectively fastened to the surface of the catheter body 100. The positions of the two end grooves 100 are fixed by the locking assembly one 210, and the excess wires are cut off to make them into one body to prevent the wires from exploding. The surface of the two end grooves 110 of the catheter body 100 is filled with a filler and heat shrunk to make it smooth. The filler heat shrinkage can further fix the end face of the lubricating layer in the groove 110. The locking assembly one 210 of the embodiment is locked by a fiber wire.

[0039] The reserved depth of the groove 110 is 20-80% of the wall thickness of the catheter body 100. When the depth of the groove 110 is less than 20% of the wall thickness of the catheter body 100, it is difficult to effectively fix the end face of the lubricating layer of the groove 110, and when the depth of the groove 110 is greater than 80% of the wall thickness of the catheter body 100, the catheter body 100 at the position of the groove 110 will have a risk of leakage after being bent multiple times, so the interval of 20-80% can effectively ensure the internal sealing of the catheter to prevent delamination leakage caused by multiple fatigue, and at the same time, the silk thread can be better covered and fixed to make the outer layer of the catheter smooth transition.

[0040] In addition, the width of the groove 110 is 2-4 mm. The minimum transition interval and silk thread fixation are ensured to prevent the silk thread from falling off under stress.

[0041] Specifically, the system of the embodiment can be: the implant sheath 400 is provided with a self-lubricating intravascular catheter structure, or the implant sheath 400 and the delivery sheath 600 are provided with a self-lubricating intravascular catheter structure, or the catheter sheath 500, the delivery sheath 600 and the implant sheath 400 are all provided with a self-lubricating intravascular catheter structure.

[0042] The lubricating layer is arranged on the surface where the catheter sheath, the delivery sheath and the implant sheath contact each other. By arranging the lubricating layer to replace the traditional hydrophilic coating, the comfort and passability in the case of needing to bend and rotate during the operation of the delivery system can be effectively improved. This is because during the bending control of the delivery system, the bending control inside of the delivery sheath 600 tightly contacts the inside of the inner cavity of the catheter sheath 500 and generates a large pressure; the bending control outside of the implant sheath 400 tightly contacts the outside of the inner cavity of the delivery sheath 600 and generates a large pressure. Figure 5 The huge pressure generated by the three-layer sheath during bending control inevitably generates a large friction force when the three-layer sheath is pushed and pulled or rotated, and simply relying on the lubricity of the catheter surface cannot meet the demand, which will cause a large resistance of the delivery sheath 600 to push and rotate in the catheter sheath 500, especially when the space bending is formed, the bending type of the delivery sheath 600 will drive the bending type of the catheter sheath 500 to rotate synchronously to a certain extent, which affects the positioning (such as Figure 6 ), and at the same time, the torque transmission is difficult to be transmitted from the proximal end of the sheath to the distal end, and the handle of the proximal delivery sheath 600 and the implant sheath 400 needs to be rotated by a large angle to accumulate force every time the head end forms a certain space angle. The hydrophilic coating will significantly decrease in strength after absorbing water (water plasticization effect) and sharply decrease in wear resistance, which is easy to cause scratching and falling off, and the particles of the fallen coating may embolize the distal blood vessels. By arranging the multi-layer catheter outer layer braid (such as Figure 7PTFE and other high lubricating wire can be woven on the surface of the catheter body 100 to produce lubricating effect, the spring force value of the weaving machine can be adjusted to increase the covering strength of the wire on the catheter, so that the wire is firmly covered on the surface of the catheter. Taking 0.08mm PTFE wire as an example, the tensile strength is between 4-5N, and the dynamic friction coefficient is between 0.03-0.08, which can effectively prevent the wire from falling off the catheter base and improve the lubricating performance of the catheter. The weaving structure and spring structure have a remarkable feature that they do not affect the bending control of the catheter and do not produce wrinkles at the inner bending of the bending control of the catheter to avoid affecting the torque performance from the proximal end to the distal end of the catheter. Compared with the hydrophilic coating of the chemical substance, the high molecular wire material is more reliable in the extreme dynamic mechanical stress and complex biological environment, and the production process is more economical and simple.

[0043] Example 2

[0044] Referring to the accompanying drawings Figure 3 The basic structure of the present embodiment is the same as that of Example 1, and the difference is that the lubricating layer of the present embodiment is formed by covering the wire structure on the outer side of the catheter body 100 in a woven manner, or first forming a net cover in a woven manner and then wrapping it on the outer side of the catheter body 100 to form, wherein the woven layer 300 is the lubricating layer, and the end surface of the woven layer 300 is placed in the groove 110 and locked and fixed by the locking assembly two 310.

[0045] The above-described embodiments only express certain embodiments of the present application, which are described in more detail and in more detail, but should not be construed as limiting the scope of the present application; It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application; Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A self-lubricating intravascular catheter delivery system, characterized by: The catheter sheath, delivery sheath and implant sheath are provided with self-lubricating intravascular catheter structure, which is a lubricating layer with lower friction coefficient than the surface of the catheter body coated on the outside of the catheter body; the lubricating layer is a dense smooth layer formed by weaving or winding a wire structure on the outside of the catheter body.

2. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The friction coefficient of the material of the lubricating layer is 0.03-0.

15.

3. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The lubricating layer is formed by one wire structure material or a mixture of two or more wire structure materials.

4. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The diameter of the wire structure is 3%-8% of the wall thickness of the catheter body.

5. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The catheter body is provided with a groove for embedding and fixing the end surface of the lubricating layer.

6. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The weaving density of the lubricating layer during weaving is PPI, and PPI is 90-150.

7. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The lubricating layer has at least one layer.

8. A self-lubricating intravascular catheter delivery system according to claim 5, wherein: The embedding and fixing of the groove and the end surface of the lubricating layer is specifically locking and fixing the end surface of the lubricating layer in the groove by using a locking assembly along the groove.

9. A self-lubricating intravascular catheter delivery system according to claim 5, wherein: The groove is also filled by filling material to make the groove flush with the surface of the catheter body.

10. A self-lubricating intravascular catheter delivery system according to claim 5, wherein: The reserved depth of the groove is 20-80% of the wall thickness of the catheter body.

11. A self-lubricating intravascular catheter delivery system according to claim 5, wherein: The width of the groove is 2-4 mm.

12. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The implant sheath is provided with self-lubricating intravascular catheter structure.

13. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The implant sheath and the delivery sheath are provided with self-lubricating intravascular catheter structure.

14. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The catheter sheath, delivery sheath and implant sheath are provided with self-lubricating intravascular catheter structure.

15. A self-lubricating intravascular catheter delivery system according to claim 1, wherein: The lubricating layer is arranged on the surface of the catheter sheath, delivery sheath and implant sheath in contact with each other.

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