WO2023216183A1

WO2023216183A1 - Laser ablation catheter

Info

Publication number: WO2023216183A1
Application number: PCT/CN2022/092430
Authority: WO
Inventors: 吴难; 潘淑芬
Original assignee: 深圳微量医疗科技有限公司
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-11-16

Abstract

A laser ablation catheter. The laser ablation catheter comprises a laser optical fiber bundle (10), an adjustable head, an outer layer pipe (30), an outer sleeve (40), and a connector (50). The outer layer pipe (30) wraps the laser optical fiber bundle (10). The adjustable head comprises an adjustable support (21). The adjustable support (21) is made of a shape memory material and sleeves one end of the outer layer pipe (30). The connector (50) is connected to the other end of the outer layer pipe (30). The laser optical fiber bundle (10) can be connected to a laser generator by means of the connector (50). The outer sleeve (40) sleeves the outer side of the adjustable support (21) and is used for compressing the adjustable support (21). At least one end of the adjustable support (21) is a movable end. The movable end is slidably connected to the outer layer pipe (30). When the outer sleeve (40) is removed, the movable end provides a condition for the deformation of the adjustable support (21). The laser ablation catheter is kept in the center of a target blood vessel by means of the adjustable head, such that laser is concentrated to irradiate a lesion position, and the adverse effect on the blood vessel wall is reduced.

Description

A laser ablation catheter

Technical field

The present application relates to the technical field of laser ablation catheters, and in particular to a laser ablation catheter.

Background technique

Coronary heart disease (CHD) is a disease with high morbidity and mortality, and percutaneous coronary intervention (PCI) is currently one of the most important surgical methods.

technical problem

Coronary artery chronic total occlusion (CTO) lesions in PCI have always been a difficulty in coronary interventional therapy. The process of CTO formation is based on severe stenosis or acute occlusion of the coronary arteries, thrombosis, and gradual fibrosis and calcification. Evolution. The proximal (end close to the operator) and distal (end far away from the operator) blood vessels of the CTO occlusion segment have different blood flow shear forces. The proximal fibrous cap is formed by fibrous tissue surrounding the thrombus and lipid components. Due to the greater The blood flow impacts the machine and has more fibrous tissue components, making it very hard. According to the degree of calcification in the plaque, it is divided into soft plaque, hard plaque and composite plaque. The degree of plaque calcification will affect the difficulty of the guide wire advancing. The more serious the calcification, the more difficult it is for the guide wire to enter the tissue space.

Excimer laser coronary plaque ablation (ELCA) is a newer PCI treatment method. The excimer laser is a cold light source that ablates plaques through a laser catheter. Because of its short wavelength and shallow ablation depth, ELCA has obvious clinical effects and a low complication rate, making it the choice for interventional treatment of complex coronary artery lesions. Clinical studies have proven that it is a safe, feasible and effective collaborative tool for treating CTO lesions.

For lesions that the guidewire can pass through but other interventional devices such as balloons cannot pass or cannot be expanded, the laser can ablate the plaque and create a path. However, for lesions that cannot be passed by the guide wire, the use of laser ablation has a high risk of vascular perforation, so ELCA is not recommended in this case. Currently, there is no ideal PCI treatment method and device for CTO lesions that cannot be passed by the guide wire.

Technical solutions

In view of the shortcomings of the existing technology, embodiments of the present application provide a laser ablation catheter, which can overcome the shortcomings of existing laser ablation catheters that easily damage target blood vessels during CTO surgery.

This laser ablation catheter includes:

Laser fiber bundle, adjustable head, outer tube, outer sleeve and connectors;

The outer tube wraps the laser fiber bundle, the adjustable head includes an adjustable bracket, the adjustable bracket is made of shape memory material, and is sleeved on one end of the outer tube, and the connector Connected to the other end of the outer tube, the laser fiber bundle can be connected to the laser generator through the connector;

The outer sleeve is set on the outside of the adjustable bracket and is used to compress the adjustable bracket;

At least one end of the adjustable bracket is a movable end, and the movable end is slidingly connected to the outer tube. When the outer tube is removed, the movable end provides conditions for the deformation of the adjustable bracket.

As a further alternative to the laser ablation catheter, one end of the adjustable bracket is a movable end and the other end is a fixed end, and the fixed end is fixedly connected to the outer tube.

As a further alternative to the laser ablation catheter, the end of the adjustable bracket away from the connector is a movable end, and the end close to the connector is a fixed end.

As a further alternative to the laser ablation catheter, a limiting platform is provided at the end of the outer tube to prevent the movable end from sliding out of the outer tube.

As a further alternative to the laser ablation catheter, one end of the adjustable bracket away from the connector is set as a fixed end, and the other end is a movable end.

As a further alternative to the laser ablation catheter, the adjustable head further includes an annular structure, and the annular structure is fixedly connected to both ends of the adjustable bracket.

As a further alternative to the laser ablation catheter, the adjustable bracket is made of nickel-titanium alloy.

As a further alternative to the laser ablation catheter, the adjustable stent is made of nickel-titanium alloy wire through a braiding process.

As a further alternative to the laser ablation catheter, the adjustable bracket is made of a nickel-titanium alloy plate through sheet metal processing.

As a further alternative to the laser ablation catheter, the adjustable bracket is made using a laser cutting process.

beneficial effects

Implementing the embodiments of this application will have the following beneficial effects:

The adjustable head added to the head end of the laser ablation catheter can adapt to the size of the target vessel after reaching the lesion location of the target vessel, thereby keeping the laser ablation catheter in the center of the vessel, allowing the laser to be concentrated at the lesion location to the greatest extent. While maximizing the effect of laser ablation, the adverse effects on the vessel wall of the target vessel are reduced, thereby reducing the risk of vessel wall complications and improving the success rate of the operation.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

in:

Figure 1 is a schematic structural diagram of a laser ablation catheter in an embodiment of the present application;

Figure 2 is a schematic cross-sectional structural diagram of a laser ablation catheter in an embodiment of the present application;

Figure 3 is a schematic structural diagram of the adjustable head end of the laser ablation catheter in one embodiment of the present application;

Figure 4 is a schematic structural diagram of an adjustable bracket made by a weaving process in an embodiment of the present application;

Figure 5 is a schematic structural diagram of an adjustable bracket made by sheet metal technology in an embodiment of the present application;

Figure 6 is a schematic structural diagram of an adjustable bracket made by laser cutting technology in one embodiment of the present application;

Description of main component symbols:

Laser fiber bundle 10; adjustable bracket 21, ring structure 22; outer tube 30, limiter 31; outer tube 40; connector 50.

Embodiments of the invention

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are shown in the accompanying drawings. However, the present application may be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough understanding of the disclosure of the present application will be provided.

It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or intervening elements may also be present. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may also be intervening elements present. The terms "vertical," "horizontal," "left," "right" and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing specific embodiments only and is not intended to limit the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Embodiments of the present application provide a laser ablation catheter, which can solve the problem that existing laser ablation catheters easily damage target blood vessels in CTO surgery.

Please refer to FIGS. 1 to 2 . The structure of the laser ablation catheter includes a laser fiber bundle 10 , an adjustable head, an outer tube 30 , an outer tube 40 and a connector 50 . The outer tube 30 is wrapped around the outside of the laser fiber bundle 10. The adjustable head includes an adjustable bracket 21. The adjustable bracket 21 is made of shape memory material and is sleeved on one end of the outer tube 30. The connector 50 is connected to At the other end of the outer tube 30, the laser fiber bundle 10 can be connected to the laser generator through the connector 50, thereby emitting laser light to irradiate the lesion position of the target blood vessel and ablate the lesion; the outer tube 40 is set on the outside of the adjustable bracket 21, and is For compressing the adjustable bracket 21; at least one end of the adjustable bracket 21 is a movable end, and the movable end is slidingly connected to the outer tube 30. When the outer tube 40 is removed, the movable end provides conditions for the deformation of the adjustable bracket 21.

The working process of the laser ablation catheter is: initially, the adjustable stent 21 is compressed in the outer cannula 40. After the laser ablation catheter extends into the lesion of the target blood vessel, the outer cannula 40 is withdrawn and the adjustable stent 21 expands to Contacting the inner wall of the target blood vessel, the laser ablation catheter is fixed in the middle of the target blood vessel, so that the laser light emitted by the laser fiber bundle 10 can accurately irradiate the lesion. During the expansion and deformation process of the adjustable bracket 21, its radial size increases and its axial size decreases. Therefore, a movable end is provided to ensure the smooth progress of the expansion process.

The adjustable head added to one end of the laser ablation catheter can adapt to the size of the target vessel after reaching the lesion location of the target vessel, thereby keeping the laser ablation catheter in the center of the target vessel, so that the laser can be concentrated at the lesion location to the greatest extent. While maximizing the effect of laser ablation, the adverse effects on the vessel wall of the target vessel are reduced, thereby reducing the risk of vessel wall complications and improving the success rate of the operation.

In one embodiment, the maximum profile diameter of the adjustable bracket 21 is 0.6mm-4mm.

In one embodiment, the adjustable head further includes an annular structure 22 , which is fixedly connected to both ends of the adjustable bracket 21 to ensure the structural stability of the adjustable bracket 21 . Without the annular structure 22, fixed connection points need to exist between the components of the adjustable bracket 21 (such as metal wires, metal strips or some polymers) to ensure the integrity of its structure, but these connection points The existence of the adjustable bracket 21 will weaken the deformation ability of the adjustable bracket 21 to a certain extent and increase the difficulty of processing; and by introducing the ring structure 22, the ends of the components of the adjustable bracket 21 can be directly fixed to the ring structure 22, reducing or even eliminating them. The connection points are fixed, thereby reducing the processing difficulty of the adjustable bracket 21 and improving its deformation ability.

In a specific embodiment, the annular structure 22 is made of metal material.

In another specific embodiment, the annular structure 22 is fixedly connected to the outer tube 30 through heat welding or glue bonding.

In one embodiment, one end of the adjustable bracket 21 is a movable end and the other end is a fixed end, and the fixed end is fixedly connected to the outer tube 30 .

In a specific embodiment, one end of the adjustable bracket 21 away from the connector 50 is a movable end, and the other end is a fixed end.

During some operations, the blood vessel wall may change from large to small. At this time, the blood vessel wall will squeeze the adjustable stent 21, causing the radial size of the adjustable stent 21 to become smaller and the axial size to increase, pushing the movement If the movable end moves toward the end of the outer tube 30, the movable end may slip off the outer tube 30.

To avoid this situation, there are two options available.

In a more specific embodiment, there is a sufficient distance between the movable end and the end of the outer tube 30. This distance can ensure that the adjustable stent 21 is pressed to fit the outer tube 30 when the blood vessel is too small. When it is on the surface, the movable end still remains on the outer tube 30.

In this solution, since a sufficient distance needs to be left between the movable end and the end of the outer tube 30, the adjustable bracket 21 has a relatively poor support effect on the end of the laser ablation catheter, that is, the laser may not focus on irradiating the lesion. There is a problem in the center; and when the adjustable bracket 21 fits the outer tube surface 31, the supporting effect will be lost. Its advantage lies in its relatively simple structure and convenient production.

In another more specific embodiment, please refer to Figure 3. A limiting platform 31 is provided near the movable end of the outer tube 30. The radial size of the limiting platform 31 is greater than the radial size of the movable end, thereby preventing the movable end from Slide off outer tube 30.

In a further specific embodiment, the relative position between the limiting platform 31 and the outer tube 30 is adjustable, that is, by adjusting the position of the limiting platform 31, the range of movement of the movable end of the adjustable bracket 21 is limited, thereby further limiting The radial size range of the adjustable stent 21 can be adjusted to better adapt to operations under different blood vessel sizes.

In a further specific embodiment, the outer tube 30 is provided with several snap-in slots, the limiting platform 31 is snap-connected with the outer tube 30, and its position can be adjusted by selecting different snap-in slots.

The advantage of using the limiting platform 31 is that the radial size of the adjustable bracket 21 can be better controlled.

In another specific embodiment, one end of the adjustable bracket 21 away from the connector 50 is configured as a fixed end, and the other end is configured as a movable end.

With this structure, during the process of withdrawing the laser ablation catheter at the end of the operation, the friction between the blood vessel wall and the adjustable stent 21 will cause the movable end to have a tendency to retract relative to the withdrawal direction. This retraction trend The radial size of the adjustable stent 21 will tend to increase, so that the adjustable stent 21 can better support the blood vessel wall during the withdrawal process, which is beneficial to the withdrawal of the laser ablation catheter. Moreover, this structure does not require the addition of a limiting platform 31 on the outer tube 30, and its processing process is simpler, so it is a preferred solution in practice.

In order to prevent the aforementioned situation where the blood vessel is too small and the adjustable stent 21 is squeezed to fit the outer tube 30, in a more specific embodiment, a limiting platform is provided near the movable end of the outer tube 30. 31, thereby limiting the deformation range of the adjustable bracket 21.

In another specific embodiment, the fixed end is fixedly connected to the outer tube 30 using a heat welding or glue bonding process.

In another embodiment, please continue to refer to FIG. 3 , both ends of the adjustable bracket 21 are configured as movable ends. With this structure, it is difficult to fix the relative position between the adjustable bracket 21 and the outer tube 30 . Therefore, it is necessary to provide limiters 31 at the positions of the outer tube 30 and the two movable ends of the adjustable bracket 21 , thereby preventing the adjustable bracket 21 from being fixed. Slide freely on the outer tube 30.

It can be understood that the adjustable bracket 21 can be made by a variety of production and processing methods, and only some preferred solutions will be described below.

In one embodiment, the adjustable bracket 21 is made of nickel-titanium alloy.

The advantage of using nickel-titanium alloy is that it is a type of shape memory metal that can return to its original shape under the temperature environment of blood. It has good corrosion resistance and has been maturely used in the medical field.

In a specific embodiment, please refer to FIG. 4 , the adjustable bracket 21 is made of nickel-titanium alloy wire through a braiding process.

In a more specific embodiment, the adjustable bracket 21 is woven into a braided tube of 2mm-3mm using nickel-titanium alloy wire with a diameter of 0.05-0.1mm, and the braided tube is fixed into a designed outline through a shaping mold. The maximum diameter is 1.5mm-3mm; the final woven mesh is placed in a vacuum heat treatment furnace for heat setting treatment. It can be understood that these figures are only empirical values in practice and are not considered to be limitations of the present application.

In another specific embodiment, the adjustable bracket 21 is made of a nickel-titanium alloy plate through sheet metal processing.

In a more specific embodiment, please refer to Figure 5. The adjustable stent 21 is composed of several nickel-titanium alloy plates surrounding the outer tube 30. The middle bulge of the structure is used to support the blood vessel wall, and the two ends are gathered into round openings. to connect with the outer tube 30.

In yet another specific embodiment, please refer to FIG. 6 , the adjustable bracket 21 is made using a laser cutting process.

In a more specific embodiment, the adjustable bracket 21 is made of a nickel-titanium metal tube with a diameter of 2mm-3mm by laser cutting into a designed mesh structure or bracket structure, and then heat-treated by a shaping mold.

Some embodiments of the laser fiber bundle 10, the outer tube 30, and the outer sleeve 40 are described below.

In one embodiment, the laser fiber bundle 10 is composed of a plurality of uniformly arranged multi-mode optical fibers, and the ends of the optical fibers are flush with the outer tube.

In a specific embodiment, a lens is fixedly connected to one end of the laser fiber bundle 10 that emits laser light.

The advantage of setting up a lens is that the laser light emitted by the laser fiber bundle 10 can be focused so that it can better ablate the lesion location.

In a more specific embodiment, the lens is made of sapphire material.

The advantage of using sapphire material is that it has high hardness, good thermal properties, chemical corrosion resistance, high temperature resistance, and meets the visibility requirements under X-rays.

In one embodiment, the outer tube 30 is made of polymer material, including but not limited to polyether block polyamide (Pebax), polyamide (PA), polytetrafluoroethylene (PTFE) or thermoplastic polyurethane elastomer. Rubber (TPU).

The advantages of using polymer materials are that they have low density, light weight under the same volume, high specific strength, and good toughness and bending fatigue strength, which can well meet the needs of use in surgery; and the PTFE material among them The friction coefficient is extremely low, which can provide better lubrication function and facilitate the movement of the laser ablation catheter in blood vessels.

In another embodiment, the two ends of the outer tube 30 and the two ends of the laser fiber bundle 10 are bonded by heat welding or glue.

In yet another embodiment, the surface of the outer tube 30 is covered with a medical hydrophilic coating. When the surface of the hydrophilic coating is exposed to water or moisture, it is able to capture water molecules. Therefore, the hydrophilic coating becomes lubricated when wetted, thereby further increasing the lubricity of the outer tube 30 .

In one embodiment, the outer sleeve 40 is also made of polymer materials, including but not limited to polyether block polyamide (Pebax), polyamide (PA), polytetrafluoroethylene (PTFE) or thermoplastic polyurethane elastomer. Rubber (TPU).

In another embodiment, the surface of the outer sleeve 40 is also covered with a hydrophilic coating to increase lubricity.

The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-described embodiments only express several implementation modes of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all fall within the protection scope of the present application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

A laser ablation catheter, characterized by including: a laser fiber bundle, an adjustable head, an outer tube, an outer sleeve and a connector;

The outer tube wraps the laser fiber bundle, the adjustable head includes an adjustable bracket, the adjustable bracket is made of shape memory material, and is sleeved on one end of the outer tube, and the connector Connected to the other end of the outer tube, the laser fiber bundle can be connected to the laser generator through the connector;

The outer sleeve is set on the outside of the adjustable bracket and is used to compress the adjustable bracket;

At least one end of the adjustable bracket is a movable end, and the movable end is slidingly connected to the outer tube. When the outer tube is removed, the movable end provides conditions for the deformation of the adjustable bracket.
The laser ablation catheter according to claim 1, wherein one end of the adjustable bracket is a movable end and the other end is a fixed end, and the fixed end is fixedly connected to the outer tube.
The laser ablation catheter according to claim 2, wherein the end of the adjustable bracket away from the connector is a movable end, and the end close to the connector is a fixed end.
The laser ablation catheter according to claim 3, wherein a limiting platform is provided at the end of the outer tube to prevent the movable end from sliding out of the outer tube.
The laser ablation catheter according to claim 2, wherein one end of the adjustable bracket away from the connector is set as a fixed end, and the other end is set as a movable end.
The laser ablation catheter according to claim 1, wherein the adjustable head further includes an annular structure, and the annular structure is fixedly connected to both ends of the adjustable bracket.
The laser ablation catheter according to claim 1, wherein the adjustable bracket is made of nickel-titanium alloy.
The laser ablation catheter according to claim 7, wherein the adjustable bracket is made of nickel-titanium alloy wire through a braiding process.
The laser ablation catheter according to claim 7, wherein the adjustable bracket is made of a nickel-titanium alloy plate through sheet metal processing.
The laser ablation catheter according to claim 7, wherein the adjustable bracket is made by laser cutting technology.