Laser ablation catheter

Abstract

The embodiment of the present application provides a laser ablation catheter, which comprises a laser fiber bundle, an adjustable head, an outer tube, a sleeve and a connector; the outer tube wraps the laser fiber bundle; the adjustable head comprises an adjustable support made of a shape memory material and sleeved at one end of the outer tube; the connector is connected to the other end of the outer tube, and the laser fiber bundle can be connected to a laser generator through the connector; the sleeve is sleeved outside the adjustable support and used for compressing the adjustable support; at least one end of the adjustable support is a movable end, and the movable end is slidingly connected to the outer tube; when the sleeve is removed, the movable end provides a condition for the deformation of the adjustable support. The laser ablation catheter is kept in the center of a target blood vessel through the adjustable head, so that the laser is concentratedly irradiated to a lesion position and the adverse effect on a blood vessel wall is reduced.

Description

Technical Field

[0001] This invention relates to the field of laser ablation catheter technology, and more particularly to a laser ablation catheter. Background Technology

[0002] Coronary heart disease (CHD) is a disease with high morbidity and mortality. Percutaneous coronary intervention (PCI) is one of the most common surgical methods.

[0003] Chronic total occlusion (CTO) of the coronary arteries has always been a challenge in percutaneous coronary intervention (PCI). CTO formation occurs on the basis of severe coronary artery stenosis or acute occlusion, with thrombus formation followed by gradual fibrosis and calcification. The blood flow shear forces differ between the proximal (closer to the operator) and distal (farthest) ends of the occluded segment of the CTO. The proximal fibrous cap, composed of fibrous tissue surrounding the thrombus and lipid components, is very rigid due to the greater impact of blood flow and the higher proportion of fibrous tissue. Based on the degree of calcification, plaques are classified as soft plaques, hard plaques, and complex plaques. The degree of plaque calcification affects the ease of guidewire advancement; the more severe the calcification, the more difficult it is for the guidewire to enter the interstitial space.

[0004] Laser-assisted coronary artery plaque ablation (ELCA) is a relatively new percutaneous coronary intervention (PCI) procedure. Using a cold light source, the excimer laser ablates plaques through a laser catheter. Due to its short wavelength and shallow ablation depth, ELCA exhibits significant clinical efficacy and a low complication rate, making it a preferred interventional treatment for complex coronary artery lesions. Clinical studies have demonstrated it to be a safe, feasible, and effective synergistic tool for managing CTO lesions.

[0005] For lesions where a guidewire can pass but other interventional devices such as balloons cannot or cannot dilate, laser ablation can be used to ablate the plaque and create a pathway. However, for lesions where a guidewire cannot pass, laser ablation carries a high risk of vascular perforation; therefore, ELCA is not recommended in such cases. Currently, there are no ideal PCI treatment methods or devices for CTO lesions that cannot be treated with a guidewire. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a laser ablation catheter that overcomes the drawback of existing laser ablation catheters easily damaging target blood vessels during CTO surgery.

[0007] The laser ablation catheter includes:

[0008] Laser fiber bundle, adjustable head, outer tube, outer sheath, and connector;

[0009] The outer tube encloses the laser fiber bundle. The adjustable head includes an adjustable bracket made of shape memory material and fitted onto one end of the outer tube. The connector is connected to the other end of the outer tube. The laser fiber bundle can be connected to the laser generator through the connector.

[0010] The outer sleeve is fitted over the outside of the adjustable bracket and is used to compress the adjustable bracket;

[0011] The adjustable bracket has at least one movable end, which is slidably connected to the outer tube. When the outer tube is removed, the movable end provides conditions for the deformation of the adjustable bracket.

[0012] As a further alternative to the laser ablation catheter, one end of the adjustable support is a movable end and the other end is a fixed end, with the fixed end fixedly connected to the outer tube.

[0013] As a further alternative to the laser ablation catheter, the end of the adjustable support furthest from the connector is the movable end, and the end closest to the connector is the fixed end.

[0014] 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.

[0015] As a further alternative to the laser ablation catheter, the end of the adjustable support away from the connector is set as a fixed end, while the other end is a movable end.

[0016] As a further alternative to the laser ablation catheter, the adjustable head also includes an annular structure, which is fixedly connected to both ends of the adjustable support.

[0017] As a further alternative to the laser ablation catheter, the adjustable stent is made of nickel-titanium alloy.

[0018] As a further alternative to the laser ablation catheter, the adjustable support is made of nickel-titanium alloy wire through a braiding process.

[0019] As a further alternative to the laser ablation catheter, the adjustable support is made of nickel-titanium alloy plate processed by sheet metal technology.

[0020] As a further alternative to the laser ablation catheter, the adjustable stent is manufactured using a laser cutting process.

[0021] Implementing the embodiments of the present invention will have the following beneficial effects:

[0022] The adjustable tip added to the laser ablation catheter can adapt to the size of the target vessel after reaching the lesion location, thereby keeping the laser ablation catheter in the center of the vessel. This allows the laser to be concentrated at the lesion location to the maximum extent, maximizing the laser ablation effect while reducing adverse effects on the target vessel wall, thus reducing the risk of vascular wall complications and improving the success rate of the operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] in:

[0025] Figure 1 This is a schematic diagram of the structure of a laser ablation catheter in one embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of a laser ablation catheter in one embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the adjustable tip of a laser ablation catheter in one embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of an adjustable bracket manufactured by a weaving process in one embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of an adjustable bracket manufactured by sheet metal process in one embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of an adjustable bracket manufactured by laser cutting process in one embodiment of the present invention;

[0031] Explanation of key component symbols:

[0032] Laser fiber bundle 10; adjustable bracket 21; ring structure 22; outer tube 30; limiting stage 31; outer tube 40; connector 50. Detailed Implementation

[0033] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0034] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] This invention provides a laser ablation catheter that can solve the problem that existing laser ablation catheters are prone to damaging target blood vessels during CTO surgery.

[0037] Please refer to the reference. Figures 1 to 2 The structure of this laser ablation catheter includes a laser fiber bundle 10, an adjustable head, an outer tube 30, an outer sheath 40, and a connector 50. The outer tube 30 wraps around the outside of the laser fiber bundle 10. The adjustable head includes an adjustable support 21, which is made of shape memory material and is fitted onto one end of the outer tube 30. The connector 50 is connected to the other end of the outer tube 30. The laser fiber bundle 10 can be connected to a laser generator through the connector 50 to emit laser light to irradiate the lesion site of the target blood vessel and ablate the lesion. The outer sheath 40 is fitted onto the outside of the adjustable support 21 and is used to compress the adjustable support 21. At least one end of the adjustable support 21 is a movable end, which is slidably connected to the outer tube 30. When the outer sheath 40 is removed, the movable end provides conditions for the deformation of the adjustable support 21.

[0038] The working process of this laser ablation catheter is as follows: Initially, the adjustable stent 21 is compressed within the outer sheath 40. After the laser ablation catheter is inserted into the lesion of the target blood vessel, the outer sheath 40 is withdrawn, and the adjustable stent 21 expands to abut against the inner wall of the target blood vessel, thereby fixing the laser ablation catheter in the middle of the target blood vessel, so that the laser emitted by the laser fiber bundle 10 can accurately irradiate the lesion. During the expansion and deformation of the adjustable stent 21, its radial dimension increases and its axial dimension decreases. Therefore, a movable end is provided to ensure that its expansion process proceeds smoothly.

[0039] An 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, thereby keeping the laser ablation catheter in the center of the target vessel. This allows the laser to be concentrated at the lesion location to the maximum extent, maximizing the laser ablation effect while reducing adverse effects on the target vessel wall, thereby reducing the risk of vascular wall complications and improving the success rate of the operation.

[0040] In one embodiment, the maximum profile diameter of the adjustable bracket 21 is 0.6 mm to 4 mm.

[0041] 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, the components of the adjustable bracket 21 (such as metal wires, metal strips, or some polymers) require fixed connection points to ensure the integrity of its structure. However, the presence of these connection points weakens the deformability of the adjustable bracket 21 to some extent and increases the processing difficulty. Introducing the annular structure 22 allows the ends of the components of the adjustable bracket 21 to be directly fixed to the annular structure 22, reducing or even eliminating the fixed connection points, thereby reducing the processing difficulty of the adjustable bracket 21 and improving its deformability.

[0042] In one specific embodiment, the ring structure 22 is made of a metallic material.

[0043] In another specific embodiment, the annular structure 22 is fixedly connected to the outer tube 30 by heat fusion or adhesive bonding.

[0044] In one embodiment, one end of the adjustable bracket 21 is a movable end and the other end is a fixed end, with the fixed end fixedly connected to the outer tube 30.

[0045] In one specific embodiment, the end of the adjustable bracket 21 away from the connector 50 is the movable end, and the other end is the fixed end.

[0046] During certain surgical procedures, the blood vessel wall may shrink from large to small. In this case, the blood vessel wall will compress the adjustable stent 21, causing the radial dimension of the adjustable stent 21 to decrease while the axial dimension increases. This pushes the movable end towards the end of the outer tube 30, and the movable end may slip off the outer tube 30.

[0047] To avoid this situation, there are two options available.

[0048] In a more specific embodiment, there is a sufficient distance between the movable end and the end of the outer tube 30, which ensures that the movable end remains on the outer tube 30 when the adjustable stent 21 is pressed against the surface of the outer tube 30 due to the small size of the blood vessel.

[0049] In this design, because sufficient distance needs to be maintained between the movable end and the end of the outer tube 30, the adjustable stent 21 provides relatively poor support for the end of the laser ablation catheter, meaning the laser may not be concentrated on the center of the lesion; and it loses its support effect when the adjustable stent 21 is in contact with the surface 31 of the outer tube. Its advantage lies in its relatively simple structure and ease of production.

[0050] 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 dimension of the limiting platform 31 is larger than the radial dimension of the movable end, thereby preventing the movable end from sliding off the outer tube 30.

[0051] 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 motion of the movable end of the adjustable stent 21 is limited, thereby further limiting the range of radial dimension change of the adjustable stent 21, so that it can better adapt to surgery under different blood vessel size conditions.

[0052] In a further specific embodiment, the outer tube 30 is provided with a plurality of snap-fit ​​slots, the limiting platform 31 snaps into the outer tube 30, and its position can be adjusted by selecting different snap-fit ​​slots.

[0053] The advantage of using the limiting stage 31 is that it allows for better control over the radial dimensions of the adjustable bracket 21.

[0054] In another specific embodiment, the end of the adjustable bracket 21 away from the connector 50 is set as a fixed end, and the other end is a movable end.

[0055] With this structure, during the withdrawal of the laser ablation catheter at the end of the procedure, the friction between the vessel wall and the adjustable stent 21 will cause the movable end to tend to retract relative to the withdrawal direction. This retraction tendency will cause the radial dimension of the adjustable stent 21 to tend to increase, thus providing better support for the vessel wall during withdrawal and facilitating the withdrawal of the laser ablation catheter. Furthermore, this structure does not require the addition of a limiting stage 31 on the outer tube 30, making its manufacturing process simpler, and therefore it is the preferred solution in practice.

[0056] To prevent the adjustable stent 21 from being squeezed into the outer tube 30 due to the aforementioned small blood vessel size, in a more specific embodiment, a limiting platform 31 is provided near the movable end of the outer tube 30 to limit the deformation range of the adjustable stent 21.

[0057] In another specific embodiment, the fixed end is fixedly connected to the outer tube 30 by heat fusion or adhesive bonding.

[0058] In another embodiment, please continue to refer to Figure 3 Both ends of the adjustable bracket 21 are set 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 set a limiting platform 31 at the position of the outer tube 30 near the two movable ends of the adjustable bracket 21 to prevent the adjustable bracket 21 from sliding freely on the outer tube 30.

[0059] It is understandable that the adjustable bracket 21 can be manufactured using various production and processing methods, and only some preferred options will be described below.

[0060] In one embodiment, the adjustable support 21 is made of nickel-titanium alloy.

[0061] The advantage of using nickel-titanium alloy is that it is a type of shape memory metal, which can restore its original shape in the temperature environment of blood and has good corrosion resistance. It has been successfully applied in the medical field.

[0062] In one specific embodiment, please refer to Figure 4 The adjustable bracket 21 is made of nickel-titanium alloy wire through a weaving process.

[0063] In a more specific embodiment, the adjustable bracket 21 is made of nickel-titanium alloy wire with a diameter of 0.05-0.1 mm, woven into a braided tube of 2 mm-3 mm. The braided tube is then fixed into a designed outline using a shaping mold, with a maximum diameter of 1.5 mm-3 mm. Finally, the shaped braided mesh is placed in a vacuum heat treatment furnace for heat setting. It is understood that these figures are merely empirical values ​​from practical experience and are not intended to limit the invention.

[0064] In another specific embodiment, the adjustable bracket 21 is made of nickel-titanium alloy plate by sheet metal processing.

[0065] 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. Its structure has a raised middle section to support the blood vessel wall and two ends that are tapered into round openings for connection with the outer tube 30.

[0066] In yet another specific embodiment, please refer to Figure 6 The adjustable bracket 21 is made using laser cutting technology.

[0067] In a more specific embodiment, the adjustable bracket 21 is made of a nickel-titanium metal tube with a diameter of 2mm-3mm, which is laser-cut into a designed mesh structure or bracket structure, and then heat-treated by a shaping mold.

[0068] The following describes some embodiments of the laser fiber bundle 10, the outer tube 30, and the outer sheath 40.

[0069] In one embodiment, the laser fiber bundle 10 is composed of multiple uniformly arranged multimode optical fibers, with the ends of the optical fibers flush with the outer tube.

[0070] In one specific embodiment, a lens is fixedly connected to one end of the laser fiber bundle 10 that emits laser light.

[0071] The advantage of setting up a lens is that it can focus the laser emitted by the laser fiber bundle 10, thereby enabling it to better ablate the lesion.

[0072] In a more specific embodiment, the lens is made of sapphire material.

[0073] The advantages of using sapphire material are its high hardness, excellent thermal properties, resistance to chemical corrosion, high temperature resistance, and ability to meet the requirements for visibility under X-rays.

[0074] In one embodiment, the outer tube 30 is made of a polymer material, including but not limited to polyether block polyamide (Pebax), polyamide (PA), polytetrafluoroethylene (PTFE), or thermoplastic polyurethane elastomer rubber (TPU).

[0075] The advantages of using polymer materials are that they have low density, are lighter in weight for the same volume, have high specific strength, and have good toughness and flexural fatigue strength, which can well meet the needs of use in surgery; while the PTFE material has an extremely low coefficient of friction, which can provide good lubrication and facilitate the movement of the laser ablation catheter in blood vessels.

[0076] In another embodiment, the two ends of the outer tube 30 are bonded to the two ends of the laser fiber bundle 10 by heat fusion or adhesive bonding.

[0077] In another embodiment, the surface of the outer tube 30 is covered with a medical-grade hydrophilic coating. When the surface of the hydrophilic coating is exposed to water or moisture, it can trap water molecules, thus becoming lubricated when wetted, thereby further increasing the lubricity of the outer tube 30.

[0078] In one embodiment, the outer sheath 40 is also made of a polymer material, including but not limited to polyether block polyamide (Pebax), polyamide (PA), polytetrafluoroethylene (PTFE), or thermoplastic polyurethane elastomer rubber (TPU).

[0079] In another embodiment, the surface of the outer sleeve 40 is also covered with a hydrophilic coating to increase lubricity.

[0080] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0081] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A laser ablation catheter, characterized by, The utility model relates to a laser ablation catheter, comprising: a laser fiber bundle, an adjustable head, an outer tube, a sleeve tube and a connector; the outer tube wraps the laser fiber bundle, the adjustable head comprises an adjustable support made of shape memory material and sleeved at one end of the outer tube, the connector is connected to the other end of the outer tube, and the laser fiber bundle can be connected with a laser generator through the connector; the sleeve tube is sleeved outside the adjustable support and is used for compressing the adjustable support; at least one end of the adjustable support is a movable end, the movable end is slidingly connected to the outer tube, when the sleeve tube is removed, the adjustable support expands to abut the inner wall of the target blood vessel and fixes the laser ablation catheter in the middle of the target blood vessel, and the movable end provides conditions for the deformation of the adjustable support; wherein one end of the adjustable support is a movable end, and the other end is a fixed end, the fixed end is fixedly connected to the outer tube; one end of the adjustable support away from the connector is set as a fixed end, and the other end is a movable end; the outer tube is provided with a limiting table near the movable end.

2. The laser ablation catheter of claim 1, wherein, One end of the adjustable support away from the connector is a movable end, and one end close to the connector is a fixed end.

3. The laser ablation catheter of claim 2, wherein, The outer tube is provided with a limiting table at the end, which is used for preventing the movable end from sliding out of the outer tube.

4. The laser ablation catheter of claim 1, wherein, The adjustable head further comprises a ring structure fixedly connected to both ends of the adjustable support.

5. The laser ablation catheter of claim 1, wherein, The adjustable support is made of nickel-titanium alloy.

6. The laser ablation catheter of claim 5, wherein, The adjustable support is made of nickel-titanium alloy wire through a weaving process.

7. The laser ablation catheter of claim 5, wherein, The adjustable support is made of a nickel-titanium alloy plate through a metal plate process.

8. The laser ablation catheter of claim 5, wherein, The adjustable support is made of a laser cutting process.

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