CN112354065A

CN112354065A - Medical catheter

Info

Publication number: CN112354065A
Application number: CN202011162097.8A
Authority: CN
Inventors: 孙剑峰; 柳逸凡; 倪尊张; 张子衡; 陈宇芬
Original assignee: Chuangmai Medical Technology Shanghai Co ltd; Shanghai Microport Medical Group Co Ltd
Current assignee: Chuangmai Medical Technology (Shanghai) Co.,Ltd.; Shanghai Weidun Medical Technology Co.,Ltd.
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2021-02-12
Also published as: CN112972864A

Abstract

The invention provides a medical catheter which comprises an inner layer, a spiral layer and a braided layer, wherein the spiral layer and the braided layer are arranged outside the inner layer, the braided layer is a net structure formed by crossed braiding of first silk threads, the spiral layer is a spiral structure formed by axially winding second silk threads, the medical catheter comprises at least two sections which are distributed along the axial direction, and the included angle formed by the first silk threads and the second silk threads in at least one section is different from the included angle formed by the first silk threads and the second silk threads in other sections. According to the medical catheter, the included angle formed by the first silk thread and the second silk thread in at least one section is different from the included angle formed by the first silk thread and the second silk thread in other sections, so that the medical catheter has good flexibility, tensile strength and radial supporting force in the distal section, the stress mutation of the distal end and the proximal end can be prevented in the middle section, the strength is high and the pushing performance is good in the proximal section, and therefore release and recovery of an intravascular interventional instrument are guaranteed.

Description

Medical catheter

The divisional application is based on the divisional application of Chinese patent application with the application number of 201911296393.4, the application date of 2019, 12 and 16, and the name of the invention is 'a medical catheter'.

Technical Field

The present invention relates to a medical catheter for delivering an endovascular interventional instrument during a surgical procedure, and more particularly, to a medical catheter for releasing and retrieving an endovascular interventional instrument during cardiac and/or aortic surgery.

Background

In cardiac surgery, when performing an intracardiac procedure, medical catheters are often required for delivering specific surgical instruments, such as endovascular interventional instruments. For example, in the case of an ultrasonically guided atrial septal defect closure procedure, a medical catheter is required to deliver the fan into the heart.

Traditional medical catheter adopts the knitting to make the enhancement layer, and the knitting is adjusted through adjusting speed of knitting and silk rotation speed and is woven the angle to preparation enhancement layer, and the medical catheter's that obtains like this tensile strength and compliance can't compromise, and the kink resistance is poor, and radial support force is poor to influenced follow-up therapeutic equipment and intervened.

Disclosure of Invention

The invention aims to provide a medical catheter, which aims to solve the technical problems that the tensile strength and the flexibility of the medical catheter cannot be considered at the same time, the anti-torsion property is poor, the radial supporting force is poor, and the subsequent intervention of a therapeutic apparatus is influenced.

In order to solve the technical problem, the invention provides a medical catheter, which comprises an inner layer, and a spiral layer and a braided layer arranged outside the inner layer, wherein the braided layer is a net structure formed by cross braiding of first silk threads, the spiral layer is a spiral structure formed by winding second silk threads along the axial direction, the medical catheter comprises at least two sections distributed along the axial direction, and an included angle formed by the first silk threads and the second silk threads in at least one section is different from included angles formed by the first silk threads and the second silk threads in other sections.

Optionally, the medical catheter comprises a distal section and a proximal section which are axially opposite, and the included angle formed by the first wire and the second wire in the distal section is smaller than the included angle formed by the first wire and the second wire in the proximal section.

Further, the first wire and the second wire form an included angle of between 15 ° and 25 ° in the distal section and an included angle of between 35 ° and 45 ° in the proximal section.

Optionally, the first filaments form the braided layer with a different pore density, and the pore density of the first filaments is between 20PPI and 120 PPI.

Further, the pore density of the braided layer becomes gradually larger from the proximal end to the distal end of the medical catheter; or the pore density of the braided layer is gradually increased from the proximal end to the distal end of the medical catheter according to the section.

Optionally, the first silk thread is made of one or a combination of aramid, polyester, polypropylene, nylon, liquid crystal polymer or nylon.

Optionally, the second filaments are helically wound at different pore densities to form the helical layer.

Further, the pore density of the spiral layer becomes gradually smaller from the proximal end to the distal end of the medical catheter; or the pore density of the spiral layer is gradually reduced from the proximal end to the distal end of the medical catheter according to the section.

Still further, the medical catheter comprises a distal section, at least one intermediate section and a proximal section distributed axially, the porosity density of the helical layer in the distal section being between 20PPI and 55PPI, the porosity density of the helical layer in the intermediate section being between 35PPI and 100PPI, and the porosity density of the helical layer in the proximal section being between 45PPI and 150 PPI.

Furthermore, the included angle between the second wire and the axial direction of the medical catheter is 45-90 degrees.

Optionally, the medical catheter further comprises an outer layer disposed outside the inner layer, and the spiral layer and the woven layer are disposed through the outer layer.

Optionally, the inner layer, the spiral layer and the woven layer of the medical catheter are sequentially arranged from inside to outside, or the inner layer, the woven layer and the spiral layer of the medical catheter are sequentially arranged from inside to outside.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a medical catheter which comprises an inner layer, and a braided layer and a spiral layer which are arranged outside the inner layer, wherein the braided layer is a net structure formed by cross braiding of first silk threads, and the spiral layer is a spiral structure formed by winding second silk threads along the axial direction; the medical catheter comprises at least two sections which are distributed along the axial direction, and the included angle formed by the first silk thread and the second silk thread in at least one section is different from the included angle formed by the first silk thread and the second silk thread in other sections. According to the medical catheter, the included angle formed by the first wire and the second wire in at least one section is different from the included angle formed by the first wire and the second wire in other sections, so that the medical catheter has good flexibility, tensile strength and radial supporting force in the distal section, can prevent stress mutation of the distal end and the proximal end in the middle section, and has high strength and good pushing performance in the proximal section, and release and recovery of an intravascular interventional instrument are guaranteed. The medical catheter is convenient for preassembling the intravascular interventional device, is not easy to deform, can easily pass through a vascular bending lesion area, ensures the stability of the intravascular interventional device in the release process of the intravascular interventional device, has low elongation, ensures the release and recovery safety of the intravascular interventional device and reduces the complexity of surgical operation.

Drawings

FIG. 1 is a perspective schematic view of a medical catheter in accordance with an embodiment of the present invention;

FIG. 2 is an axial cross-sectional view of a medical catheter in accordance with an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a spiral layer according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a relative angle between the spiral layer and the braid layer according to an embodiment of the present invention.

Description of reference numerals:

100-an outer layer;

200-a helical layer;

300-weaving layer;

400-inner layer.

Detailed Description

A medical catheter of the present invention will be described in further detail below. The present invention will now be described in more detail with reference to the accompanying drawings, in which preferred embodiments of the invention are shown, it being understood that one skilled in the art may modify the invention herein described while still achieving the advantageous effects of the invention. Accordingly, the following description should be construed as broadly as possible to those skilled in the art and not as limiting the invention.

In the interest of clarity, not all features of an actual implementation are described. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific details must be set forth in order to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art.

In order to make the objects and features of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise ratio for the purpose of facilitating and distinctly aiding in the description of the embodiments of the invention.

Fig. 1 is a perspective view schematically illustrating a medical catheter according to an embodiment of the present invention. As shown in fig. 1, the present embodiment provides a medical catheter, which can be used as a delivery sheath or for other medical purposes. The medical catheter is, for example, a hollow tube, and in this embodiment, the medical catheter is, for example, a delivery sheath, which is used to provide a delivery path for an intravascular interventional device, release and retrieval of an intravascular interventional device, and the like. The diameter of the medical catheter includes, but is not limited to, between 6F-12F to facilitate delivery of the interventional device into a blood vessel during cardiac or aortic surgery. In other embodiments, the diameter of the medical catheter may be modified according to actual needs.

The medical catheter comprises at least two sections distributed along the axial direction, and specifically, the medical catheter comprises two sections distributed along the axial direction, namely a distal section and a proximal section which are opposite along the axial direction; alternatively, the medical catheter comprises at least three axially distributed sections, respectively a distal section, a proximal section, which are axially opposite, and at least one intermediate section between the distal section and the proximal section. The distal section may be a constriction, i.e. the diameter of the distal section gradually decreases towards the side remote from the proximal section, so that the medical catheter can enter the blood vessel without scratching the blood vessel wall during operation. The tensile strength of the medical catheter can reach 60N-120N so as to ensure sufficient pushing force when the intravascular interventional device is released, the stability of the intravascular interventional device and lower elongation. It should be noted that the proximal end refers to the end close to the operator, and the distal end refers to the end away from the operator.

Fig. 2 is an axial cross-sectional view of a medical catheter in accordance with an embodiment of the present invention. As shown in fig. 2 and referring to fig. 1, the medical catheter includes an inner layer 400, and a spiral layer 200 and a woven layer 300 disposed outside the inner layer 400, wherein the inner layer 400, the spiral layer 200 and the woven layer 300 are sequentially disposed from inside to outside. In other embodiments, the medical catheter may further have a structure in which the inner layer, the woven layer, and the spiral layer are sequentially disposed from inside to outside. The medical catheter may further include an outer layer 100 disposed outside the inner layer 400, and the spiral layer 200 and the braid layer 300 are penetrated into the outer layer 100. In other embodiments, the spiral layer 200 and the woven layer 300 may also be disposed between the inner layer 400 and the outer layer 100.

The material of the outer layer 100 may be any one of fluorine-containing polymer resins such as polyether-amino block copolymer resin (PEBAX), NYLON resin (NYLON), POLYIMIDE resin (polyimid) or Polytetrafluoroethylene (PTFE). Preferably, the material of the outer layer 100 is PEBAX, so as to increase the flexibility and chemical resistance of the outer layer 100 and the corrosion resistance of salt or sulfuric acid, and simultaneously reduce the resistance of the outer layer 100 in blood, and improve the biocompatibility of the outer layer 100. The PEBAX has a variety of hardness options, for example ranging from shore 25D to shore 74D. The outer layer 100 may be integrally formed by selecting PEBAX with corresponding hardness according to specific product requirements, or may be formed by using PEBAX with different hardness at different positions of the same outer layer 100, for example, PEBAX with higher hardness at the proximal end of the outer layer 100, and PEBAX with lower hardness at the distal end portion of the outer layer 100, so that the proximal end of the medical catheter has excellent pushing ability and strength, and the distal end of the medical catheter has excellent flexibility and bending performance.

Optionally, the outer layer 100 may have a coating on its outer wall, such as a hydrophilic coating, a hydrophobic coating, or a self-lubricating fluoroplastic, to facilitate easy access of the medical catheter into the blood vessel.

The inner layer 400 forms a hollow chamber that may be used for placement of an endovascular access device. The material of the inner layer 400 may be Polytetrafluoroethylene (PTFE), which has excellent chemical stability, corrosion resistance, sealability, high lubrication non-stick properties, and biocompatibility. The inner layer 400 is made of PTFE material, so that the release resistance of the intravascular interventional device can be reduced, the positioning accuracy and controllability of the intravascular interventional device during release can be improved, and the resistance of the medical catheter during entering a blood vessel can be reduced; in addition, the inner layer 400 has the advantages of low friction coefficient, strong biocompatibility, no rejection to human bodies, no physiological side effect to human bodies and the like.

The braided layer 300 is, for example, mesh-shaped to increase the strength and flexibility of the medical catheter in the radial and axial directions. For example, the woven layer 300 is formed by cross-weaving a plurality of first filaments, specifically, the woven layer 300 may be formed by cross-weaving a strand of woven rope formed by spirally winding a plurality of first filaments, or may be formed by directly cross-weaving a plurality of first filaments, so as to ensure the tensile strength of the woven layer 300, provide mechanical properties similar to those of a cable, have good flexibility, and have good fatigue resistance after multiple spiral bending, thereby being suitable for the case of blood vessel tortuosity. Preferably, the braided layer 300 is formed by, for example, cross-braiding 4 to 64 first filaments. For example, the first yarn is formed by knitting the knitted layer 300 in an upper-lower cross manner, or formed by knitting the knitted layer 300 in an upper-lower cross manner, but the knitted layer 300 may also be formed by other cross knitting manners, specifically, knitting may be performed according to actual situations. The first filaments may be braided with a uniform porosity to form the braided layer 300, or may be braided with a different porosity to form the braided layer 300, for example, the porosity of the braided layer 300 may gradually increase from the proximal end to the distal end of the medical catheter; or the porosity density of the braided layer 300 becomes progressively greater in the section from the proximal end to the distal end of the medical catheter. The pore density of the first filaments can be specifically changed according to the stress requirement of the medical catheter and the specific material of the first filaments. Preferably, the first wire has a pore density gradually increasing from the proximal end to the distal end, and the density is between 20PPI and 120PPI, so that the medical catheter has good support, flexibility and pushing performance, and the braided layer 300 can bear most of axial tensile force when releasing the intravascular interventional device. The diameter of the first wire is in the range of 0.012mm-0.1mm, further the diameter of the first wire is in the range of 0.012mm-0.05mm, preferably the diameter of the first wire is in the range of 0.012mm-0.025 mm. The first silk thread can be made of one or a combination of polymer materials such as Aramid (AF), Polyester (PES), Polyester (PET), polypropylene (PP), NYLON (NYLON), Liquid Crystal Polymer (LCP) or chinlon, so that the deformation resistance of the woven layer 300 is improved, the adhesion between the woven layer 300 and the outer layer 100 is improved, the wall thickness of the medical catheter is reduced, and a large inner cavity is obtained while blood vessels are not stimulated.

Fig. 3 is a schematic structural diagram of a spiral layer according to an embodiment of the present invention. As shown in fig. 3, the spiral layer 200 is, for example, spiral along the axial direction to increase the strength and flexibility of the medical catheter along the axial direction. The spiral layer 200 may be formed by spirally winding a plurality of second silk threads in the axial direction, and specifically, the spiral layer 200 may be formed by spirally winding a plurality of second silk threads in the axial direction after spirally winding the second silk threads in the axial direction to form a spiral rope, or may be formed by directly spirally winding a plurality of second silk threads in the axial direction; the spiral layer 200 may also be a tube cut by laser. In addition, the second wires may form the spiral layer 200 with a uniform pore density, or may form the spiral layer 200 with a different pore density. The pore density of the spiral layer 200 may taper from the proximal end to the distal end of the medical catheter; or the pore density of the spiral layer may taper in sections from the proximal end to the distal end of the medical catheter.

The medical catheter may comprise at least three axially distributed segments, respectively a distal segment, a proximal segment, and at least one intermediate segment between the distal and proximal segments, which are axially opposite. The pore density of the helical layer 200 in the distal segment is between 20PPI-55 PPI. Preferably, the pore density of the helical layer 200 in the distal segment is between 20PPI and 35 PPI. The pore density of the spiral layer 200 in the intermediate section is between 35PPI and 100 PPI. Preferably, the pore density of the helical layer 200 in the intermediate section is between 35PPI and 45 PPI. The pore density of the helical layer 200 in the proximal section is between 45PPI and 150 PPI. Preferably, the pore density of the helical layer 200 in the proximal section is between 45PPI and 60 PPI. The diameter of the second wire is for example between 0.025mm and 0.3mm, and the second wire is for example a round or flat wire.

The included angle between the second silk thread and the axial direction of the medical catheter can be 45-90 degrees. Preferably, the second wire is at an angle of 60 ° to 80 ° with respect to the axial direction of the medical catheter, so that the spiral layer 200 supports the supporting force of the intravascular interventional device in the radial direction of the medical catheter during deployment, and also can maintain the medical catheter to have strong kink resistance, and not suffer physical damage, such as deformation or bending, at the bending position of the blood vessel or when the manipulation force is large. The second wire can be made of metal such as stainless steel or nickel-titanium alloy, polymer material such as polyether ether ketone (PEEK) or High Density Polyethylene (HDPE), or composite material of metal, polymer and inorganic nonmetal.

Fig. 4 is a schematic structural diagram of a relative angle between the spiral layer and the braid layer according to an embodiment of the present invention. As shown in fig. 4, the first wires and the second wires form an included angle a, and specifically, the included angle a formed by the first wires and the second wires in at least one of the sections of the medical catheter is different from the included angle a formed by the first wires and the second wires in other sections of the medical catheter, so that the medical catheter has good flexibility, tensile strength and radial supporting force in a distal section of the medical catheter, can prevent sudden stress change in the distal section and a proximal section of the medical catheter in a middle section of the medical catheter, and has higher strength and good pushability in a proximal section of the medical catheter, thereby ensuring release and recovery of an intravascular interventional instrument. The angle a formed by the first and second wires in the distal section may be smaller than the angle a formed by the first and second wires in the proximal section. The first and second wires may form an included angle a of between 10 ° and 50 °. Preferably, the included angle formed by the first wire and the second wire in the distal section is 15-25 degrees, and the included angle formed by the first wire and the second wire in the proximal section is 35-45 degrees, so that the bearing capacity of the medical catheter along the axial direction of the medical catheter is improved, and the elongation of the medical catheter along the axial direction of the medical catheter is reduced. It should be noted that the included angle is defined as an included angle projected in the axial direction of the first wire and the second wire.

Optionally, the medical catheter further includes a radiographic marker, the radiographic marker is sleeved on the distal end of the braided layer 300, the radiographic marker includes a developing point or a developing ring, and the radiographic marker is made of a metal or other materials, such as platinum-iridium alloy, tungsten, and the like, which can be developed under X-ray, so as to facilitate monitoring of the position of the medical catheter by an operator.

In summary, the medical catheter provided by the invention includes an inner layer, a spiral layer and a woven layer, which are sequentially arranged from inside to outside, the woven layer is a mesh structure formed by first silk threads through cross weaving, the spiral layer is a spiral structure formed by second silk threads wound along an axial direction, the medical catheter includes at least two sections distributed along the axial direction, and an included angle formed by the first silk threads and the second silk threads in at least one section is different from included angles formed by the first silk threads and the second silk threads in other sections. According to the medical catheter, the included angle formed by the first wire and the second wire in at least one section is different from the included angle formed by the first wire and the second wire in other sections, so that the medical catheter has good flexibility, tensile strength and radial supporting force in the distal section, can prevent stress mutation of the distal end and the proximal end in the middle section, and has high strength and good pushing performance in the proximal section, and release and recovery of an intravascular interventional instrument are guaranteed. The medical catheter is convenient for preassembling the intravascular interventional device, is not easy to deform, can easily pass through a vascular bending lesion area, ensures the stability of the intravascular interventional device in the release process of the intravascular interventional device, has low elongation, ensures the release and recovery safety of the intravascular interventional device and reduces the complexity of surgical operation.

In addition, it should be noted that the description of the terms "first", "second", and the like in the specification is only used for distinguishing each component, element, step, and the like in the specification, and is not used for representing a logical relationship or a sequential relationship between each component, element, step, and the like, unless otherwise specified or indicated.

It is to be understood that while the present invention has been described in conjunction with the preferred embodiments thereof, it is not intended to limit the invention to those embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.

Claims

1. A medical catheter is characterized by comprising an inner layer, a spiral layer and a woven layer, wherein the spiral layer and the woven layer are arranged outside the inner layer, the woven layer is a net structure formed by first silk threads in a crossed and woven mode, the spiral layer is a spiral structure formed by second silk threads wound in an axial direction, the medical catheter comprises at least two sections distributed in the axial direction, and the included angle formed by the first silk threads and the second silk threads in at least one section is different from the included angles formed by the first silk threads and the second silk threads in other sections; the medical catheter comprises a distal section and a proximal section which are opposite along the axial direction, wherein the included angle formed by the first wire and the second wire in the distal section is smaller than the included angle formed by the first wire and the second wire in the proximal section.

2. The medical catheter of claim 1, wherein said first wire and said second wire form an angle between 15 ° and 25 ° in said distal section and said first wire and said second wire form an angle between 35 ° and 45 ° in said proximal section.

3. The medical catheter of claim 1, wherein said first filaments form said braid at different pore densities, and wherein said first filaments have a pore density between 20PPI and 120 PPI.

4. The medical catheter of claim 3, wherein said braided layer has a pore density that increases from a proximal end to a distal end of said medical catheter; or the pore density of the braided layer is gradually increased from the proximal end to the distal end of the medical catheter according to the section.

5. The medical catheter of claim 1, wherein the first thread is made of one or a combination of aramid, polyester, polypropylene, nylon, liquid crystal polymer, and nylon.

6. The medical catheter of any one of claims 1-5, wherein said second wire is helically wound at a different pore density to form said helical layer.

7. The medical catheter of claim 6, wherein the helical layer has a pore density that tapers from the proximal end to the distal end of the medical catheter; or the pore density of the spiral layer is gradually reduced from the proximal end to the distal end of the medical catheter according to the section.

8. The medical catheter of claim 7, wherein the medical catheter comprises a distal section, at least one intermediate section and a proximal section distributed axially, wherein the helical layer has a pore density in the distal section between 20PPI and 55PPI, wherein the helical layer has a pore density in the intermediate section between 35PPI and 100PPI, and wherein the helical layer has a pore density in the proximal section between 45PPI and 150 PPI.

9. The medical catheter of claim 6, wherein said second wire is angled 45 ° -90 ° from an axial direction of said medical catheter.

10. The medical catheter of claim 1, further comprising an outer layer disposed outside of the inner layer, and wherein the helical layer and the braided layer are disposed through the outer layer.

11. The medical catheter of claim 1, wherein said inner layer, said helical layer and said braided layer of said medical catheter are disposed in sequence from inside to outside, or said inner layer, said braided layer and said helical layer of said medical catheter are disposed in sequence from inside to outside.