CN113577501A

CN113577501A - Retraction-preventing catheter

Info

Publication number: CN113577501A
Application number: CN202110796525.0A
Authority: CN
Inventors: 王越; 程瑞; 孙璐; 李志刚; 王国辉
Original assignee: Shanghai Xinwei Medical Technology Co ltd
Current assignee: Shanghai Xinwei Medical Technology Co ltd
Priority date: 2021-07-14
Filing date: 2021-07-14
Publication date: 2021-11-02
Anticipated expiration: 2041-07-14
Also published as: CN113577501B

Abstract

The invention belongs to the field of medical instruments, particularly relates to the field of A61M25/00, and particularly relates to an anti-retraction catheter. An anti-retraction catheter comprises an inner catheter and an outer catheter, wherein the inner catheter and the outer catheter are coaxially arranged, the outer catheter is arranged outside the inner catheter, and the axial length of the outer catheter is smaller than that of the inner catheter; the outer catheter and the inner catheter realize relative sliding in the axial direction through an extracorporeal control device. The principle of adjusting the passing resistance of the catheter in the blood vessel is utilized, the resistance of the catheter is minimized during the delivery and the recovery of the catheter, and the maximum passing performance of the catheter is given; after the catheter reaches the lesion part, the resistance on the surface of the catheter is increased, so that the catheter is difficult to move, and the retraction phenomenon of the catheter is effectively prevented.

Description

Retraction-preventing catheter

Technical Field

The invention belongs to the field of medical instruments, particularly relates to the field of A61M25/00, and particularly relates to an anti-retraction catheter.

Background

With the development of social economy, the national life style is deeply changed, particularly, the aging of population and the urbanization progress are accelerated, the prevalence trend of cardiovascular disease risk factors in China is obvious, and the number of people suffering from cardiovascular diseases is continuously increased. At present, about 220 tens of thousands of patients suffering from chronic total occlusion lesions of coronary arteries in China exist. Clinically, when minimally invasive interventional therapy is performed on a blood vessel with a chronic total occlusion lesion or a vascular dissection, a catheter and other interventional devices are usually required to be used in cooperation for performing therapeutic operation, such as balloon dilatation, stent implantation and other technical means. In the operation process, the catheter is often required to be pushed to the pathological change position from the outside of the body, so that the catheter is required to have strong pushing performance, bending resistance, flexibility and the like, and the micro-catheter is ensured to accurately reach the pathological change part of a patient and pass through the pathological change blood vessel without damaging the healthy blood vessel in the operation process.

Chinese patent publication No. CN109498957A provides a novel microcatheter, discloses a novel microcatheter, is a tubular structure, includes head end, tube body, diffusion stress tube and needle seat that set gradually from distal end to proximal end, wherein: developing materials are doped in the head end, and a developing ring is arranged between the head end and the tube body; the pipe body sequentially comprises an outer sleeve layer, a woven reinforcing layer, a woven layer and an inner liner layer from outside to inside; and the near end of the tube body is fixedly connected with the needle seat, and the joint of the near end of the tube body and the needle seat is sleeved with the diffusion stress tube. The novel microcatheter has strong pushing performance, bending resistance and tracking performance, and the microcatheter gradually hardens from the far end to the near end, so that the flexibility and the shape maintaining performance of the far end can be ensured, and the microcatheter can accurately reach the pathological change part of a patient and pass through a tortuous pathological change blood vessel in the operation process. U.S. patent publication No. CN102014773B provides a catheter system for opening blocked vascular passageways, disclosing a rotary cutting head catheter for crossing chronic total occlusions or other persistent atherosclerotic plaques in diseased arteries. When not in use, the rotating cutting head of the catheter is designed to be safely housed in an outer protective sheath. The outer protective sheath includes one or more helical grooves or slots and the cutting head includes protruding blades or projections that fit in these helical grooves or slots. Application of torque to an internal catheter or wire attached to the cutting head causes the cutting head to rotate and the force of the helical groove or slit of the sheath against the protruding blade or protrusion of the cutting head pushes the cutting head out of the protective sheath. Once extended, the cutting head may be freely rotated. The device may use a guide wire to guide the cutting head to the desired position.

Similar to the above patents, when the conventional catheter (middle catheter, micro catheter, etc.) is used with an interventional device, the catheter is often retracted due to the large supporting force required to be provided when the interventional device passes through the inside of the catheter, especially through a tortuous part, and the retraction is often caused by the movement and deformation of the catheter in the blood vessel. In addition to providing greater support, catheter movement and deformation are due, in part, to increased catheter throughput, often to the surface of the catheter being coated with a hydrophilic coating to reduce the resistance of the catheter to movement through the blood vessel, which results in a catheter that is highly susceptible to movement within the blood vessel, especially when subjected to high forces. Once the catheter is retracted, the distal end of the catheter may be withdrawn from the lesion and fail to function.

Disclosure of Invention

Aiming at the problems, the invention provides an anti-retraction catheter structure which can ensure that a catheter can smoothly pass through a blood vessel and can effectively fix the catheter after the catheter reaches a diseased position.

An anti-retraction catheter comprises an inner catheter and an outer catheter, wherein the inner catheter and the outer catheter are coaxially arranged, the outer catheter is arranged outside the inner catheter, and the axial length of the outer catheter is smaller than that of the inner catheter; the outer catheter and the inner catheter realize relative sliding in the axial direction through an extracorporeal control device.

As a preferred technical scheme, the inner conduit is arranged in a multi-layer structure which is coaxially arranged, and the inner conduit is sequentially arranged from inside to outside into an inner liner layer, a reinforcing layer and an outer sleeve layer; the inner liner, the reinforcing layer and the outer sleeve layer are sequentially and fixedly arranged.

In a preferred embodiment, the frictional resistance of the outer sheath layer to pass through the blood vessel is smaller than the frictional resistance of the outer catheter to pass through the blood vessel.

As a preferable technical solution, the frictional resistance between the outer catheter and the outer jacket layer is smaller than the frictional resistance of the outer catheter passing through the blood vessel.

As a preferred technical solution, the outer wall of the outer catheter is provided with a hydrophilic coating.

As a preferred solution, the axial length of the outer catheter is at least 1500 mm.

Preferably, the difference between the axial lengths of the inner and outer conduits is at least 200 mm.

In a preferred embodiment, the anti-retraction catheter includes a first configuration, and the outer catheter is coincident with the inner catheter distal end when the anti-retraction catheter is in the first configuration.

In a preferred embodiment, the retraction-prevention catheter comprises a second configuration, wherein when the retraction-prevention catheter is in the second configuration, the outer catheter is coincident with the inner catheter proximal end, and the inner catheter distal portion is exposed outside the outer catheter covering region.

As a preferable technical scheme, the material of the hydrophilic coating is polyvinyl pyrrolidine or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methyl propiophenone.

Has the advantages that:

the invention provides an anti-retraction catheter, which utilizes the principle of adjusting the passing resistance of the catheter in a blood vessel, minimizes the resistance of the catheter during the delivery and the recovery of the catheter and provides the maximum passing performance of the catheter; after the catheter reaches the lesion part, the resistance on the surface of the catheter is increased, so that the catheter is difficult to move, and the retraction phenomenon of the catheter is effectively prevented.

The passing resistance of the catheter in the blood vessel is changed by adjusting the catheter resistance adjusting layer, so that the passing performance of the catheter is kept, and the position of the catheter is fixed after the catheter reaches a lesion position, so that the retraction of the catheter is prevented. The catheter has multiple functions, and can be used for treatment means such as internal guide wires, stents or auxiliary thrombus suction.

Drawings

FIG. 1 is a schematic view of an anti-retraction catheter according to the present invention;

FIG. 2 is a schematic structural view of an anti-retraction catheter provided in accordance with the present invention in a first configuration;

FIG. 3 is a schematic structural view of an anti-retraction catheter provided in accordance with the present invention in a second configuration;

wherein, 1-inner conduit, 11-inner liner layer, 12-reinforcing layer, 13-outer jacket layer, 2-outer conduit.

Detailed Description

An anti-retraction catheter comprises an inner catheter 1 and an outer catheter 2, wherein the inner catheter 1 and the outer catheter 2 are coaxially arranged, the outer catheter 2 is arranged outside the inner catheter 1, and the axial length of the outer catheter 2 is smaller than that of the inner catheter 1; the outer catheter 2 and the inner catheter 1 realize relative sliding in the axial direction through an extracorporeal control device.

In some preferred embodiments, the inner catheter 1 is provided as a coaxially arranged multilayer structure, and the inner catheter 1 is provided with an inner liner layer 11, a reinforcing layer 12 and an outer jacket layer 13 from inside to outside; the inner liner layer 11, the reinforcing layer 12 and the outer sleeve layer 13 are fixedly arranged in sequence.

The invention does not limit the material composition of the inner liner layer, the reinforcing layer and the outer sleeve layer, in some embodiments, the inner liner layer is made of high-density polyethylene or polytetrafluoroethylene, and the inner liner layer is made of the high-density polyethylene and the high-density polytetrafluoroethylene, so that the mechanical strength of the whole micro-catheter is improved, and the diameter of the micro-catheter is ensured to be smaller so that the micro-catheter can smoothly enter the blood vessel of a human body; the reinforcing layer is formed by weaving stainless steel braided wires or nickel titanium braided wires, the pushing performance and the twisting performance can be enhanced by adding the reinforcing layer, the inner catheter has smaller size, the passing performance of the blood vessel is improved, and particularly when lesion occurs in a highly tortuous side branch part, the inner catheter with the design has very obvious clinical advantages; the outer sleeve layer is made of one or more of polyamide, polyurethane and polyolefin materials.

In some preferred embodiments, the frictional resistance to the intravascular passage of the outer sheath 13 is less than the frictional resistance to the intravascular passage of the outer catheter 2.

In the invention, the moving capacity of the catheter in the blood vessel is improved/reduced by changing the passing resistance of the catheter by utilizing the difference of the frictional resistance; when the catheter needs to smoothly pass through a blood vessel and quickly pass through the blood vessel, the far end of the outer catheter is superposed with the inner catheter, the far end of the inner catheter is coated by the outer catheter, and the surface of the outer catheter exposed in the blood vessel and the surface of the catheter exposed in the blood vessel are the surfaces of the outer catheter with the hydrophilic coating, so that the friction force is small, and the rapid and smooth passing in the blood vessel can be realized. (ii) a When the catheter smoothly reaches a diseased region and needs to be matched with other interventional devices for use, the position of the catheter in a blood vessel is required to be kept stable so as to provide the supporting force required by other interventional devices, and the outer catheter is adjusted to enable the proximal end of the outer catheter to coincide with the proximal end of the inner catheter so as to realize that the surface of the inner catheter is exposed in the blood vessel to the maximum extent. Because the surface of the inner catheter is not coated with the hydrophilic coating, the inner catheter has larger moving resistance in the blood vessel, thereby playing the role of fixing the position of the inner catheter in the blood vessel.

In some preferred embodiments, the frictional resistance between the outer catheter 2 and the outer sheath 13 is less than the frictional resistance of the outer catheter 2 to travel within the blood vessel.

In the invention, the outer catheter and the inner catheter need to axially move relative to each other, and if the frictional resistance between the outer catheter and the outer sleeve layer is too large, smooth relative sliding cannot be realized, so that the relative position of the inner catheter in a blood vessel can be affected while the outer catheter is moved, and the pulling or damage to the blood vessel can be caused, thereby causing adverse effects.

In some preferred embodiments, the outer wall of the outer catheter 2 is provided with a hydrophilic coating.

The hydrophilic coating is used for reducing the friction coefficient between the outer wall of the outer catheter 2 and the blood vessel, and reducing the passing resistance of the catheter, so that the area coated by the outer catheter can rapidly pass through the blood vessel.

In some preferred embodiments, the outer catheter 2 has an axial length of at least 1500 mm. The conveying length of the catheter in a human body can be completely covered when the catheter is conveyed, and the tail end is placed outside the body, so that the position of the outer catheter can be conveniently adjusted.

In some preferred embodiments, the difference in axial length between the inner catheter 1 and the outer catheter 2 is at least 200 mm. Giving room for the outer catheter to adjust its position.

In some preferred embodiments, the anti-retraction catheter comprises a first configuration, when the anti-retraction catheter is in the first configuration, the outer catheter 2 is coincident with the distal end of the inner catheter 1. At the moment, the contact part of the catheter and the blood vessel is provided with the hydrophilic coating, and the friction resistance is minimum, so that the catheter can conveniently pass through the blood vessel.

In some preferred embodiments, the anti-retraction catheter comprises a second configuration, when the anti-retraction catheter is in the second configuration, the outer catheter 2 is coincident with the proximal end of the inner catheter 1, and the distal portion of the inner catheter 1 is exposed outside the envelope of the outer catheter 2. At the moment, the area of the part of the catheter with the hydrophilic coating is the minimum, the resistance on the surface of the catheter is increased, the catheter is difficult to move, and the retraction phenomenon of the catheter is effectively prevented.

In some preferred embodiments, the material of the hydrophilic coating is provided as polyvinylpyrrolidine or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone.

The working principle is as follows: before the catheter is used and is conveyed in a blood vessel, the anti-retraction catheter is in a first configuration, the outer catheter and the inner catheter are overlapped at the distal end of the catheter, namely the outer catheter completely covers the distal end of the anti-retraction catheter, and the part of the anti-retraction catheter in the body is covered by the outer catheter with the hydrophilic coating, so that the passing resistance of the anti-retraction catheter is minimum. When the retraction catheter is conveyed in place in a blood vessel and is matched with other interventional equipment for use, the outer catheter is retracted, so that the retraction-preventing catheter is in the second configuration, the outer jacket layer at the far end of the retraction-preventing catheter is exposed to the outside to the maximum extent, and the passing resistance of the retraction-preventing catheter is increased. When the interventional therapy is finished and the anti-retraction catheter is recovered, the anti-retraction catheter is returned to the first configuration again, the outer catheter is adjusted to cover the distal end of the inner catheter again, and the passing resistance of the anti-retraction catheter in the blood vessel is reduced, so that the recovery of the anti-retraction catheter is ensured to be carried out smoothly.

Claims

1. An anti-retraction catheter is characterized by comprising an inner catheter (1) and an outer catheter (2), wherein the inner catheter (1) and the outer catheter (2) are coaxially arranged, the outer catheter (2) is arranged outside the inner catheter (1), and the axial length of the outer catheter (2) is smaller than that of the inner catheter (1); the outer catheter (2) and the inner catheter (1) realize relative sliding in the axial direction through an extracorporeal control device.

2. The retraction-prevention catheter as claimed in claim 1, characterized in that the inner catheter (1) is provided as a coaxially arranged multilayer structure, the inner catheter (1) being provided in order from the inside to the outside as an inner liner (11), a reinforcing layer (12), an outer jacket layer (13); the inner liner layer (11), the reinforcing layer (12) and the outer sleeve layer (13) are sequentially and fixedly arranged.

3. Anti-retraction catheter according to claim 2, characterized in that the frictional resistance to the passage of the outer sheath (13) within the blood vessel is lower than the frictional resistance to the passage of the outer catheter (2) within the blood vessel.

4. Anti-retraction catheter according to claim 2, characterized in that the frictional resistance between the outer catheter (2) and the outer sheath (13) is smaller than the frictional resistance of the outer catheter (2) to passage within the blood vessel.

5. Anti-retraction catheter according to claim 1, characterized in that the outer wall of the outer catheter (2) is provided with a hydrophilic coating.

6. Anti-retraction catheter according to claim 1, characterized in that the axial length of the outer catheter (2) is at least 1500 mm.

7. Anti-retraction catheter according to claim 1 or 6, characterized in that the difference in axial length of the inner catheter (1) and the outer catheter (2) is at least 200 mm.

8. An anti-retraction catheter according to claim 1, characterized in that the anti-retraction catheter comprises a first configuration, when the anti-retraction catheter is in the first configuration, the outer catheter (2) coincides with the inner catheter (1) distal end.

9. The anti-retraction catheter according to claim 1, characterized in that it comprises a second configuration, when in which the outer catheter (2) coincides with the proximal end of the inner catheter (1), the distal portion of the inner catheter (1) being exposed outside the envelope of the outer catheter (2).

10. The retraction-prevention catheter as recited in claim 5, wherein the material of the hydrophilic coating is provided as polyvinylpyrrolidone or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone.