Catheter assembly, dilation sheath, and transfemoral access system

Abstract

The application provides a catheter assembly, a dilating sheath and a transfemoral arterial access system. An outer sheath is sleeved on the outside of an inner catheter, and a tube gap between the outer sheath and the inner catheter forms a fluid channel. The outer sheath includes a fixed diameter tube section and a variable diameter tube section along the axial direction thereof, and a blocking part is arranged at the distal end of the outer sheath. The blocking part has a contracted state and an expanded state. The channel for blood flow and the channel for conveying medical devices belong to two different channels, and the blood flow and the device conveying are separated, which can avoid the obstruction of the device conveying to the blood flow, solve the problem that the reverse flow channel cross-sectional area is limited, and the device conveying and the reverse flow function are restricted. Moreover, the variable diameter tube section can be kept in a small radial size state when it is not radially expanded. At this time, the variable diameter tube section at the distal end can keep a small radial size when the dilating sheath is placed into the femoral artery, so that the mechanical stimulation to the blood vessel wall can be reduced, and the risk of blood vessel injury and plaque shedding can be reduced.

Description

Technical Field

[0001] This invention relates to catheter assemblies, dilating sheaths, and transfemoral artery access systems, belonging to the field of medical device technology. Background Technology

[0002] Carotid artery stenosis is a significant contributing factor to ischemic stroke. For patients unsuitable for traditional carotid endarterectomy, endovascular carotid revascularization is increasingly being used. During carotid artery stenting, the risk of cerebral embolism due to plaque or thrombus dislodgement is a critical issue affecting surgical safety. Therefore, brain protection techniques are becoming a key area of ​​development.

[0003] Currently, proximal brain protection and blood flow reversal systems that operate on the carotid artery region via femoral artery puncture or carotid artery incision can reverse cerebral blood flow by establishing vascular occlusion in the common carotid artery and cooperating with an external circuit, thereby reducing the risk of emboli entering the intracranial circulation during interventional procedures.

[0004] However, existing femoral artery access systems have several drawbacks when performing carotid artery interventional brain protection techniques via the femoral artery approach. These include limited cross-sectional area of ​​the blood flow reversal channel, mutual constraints between device delivery and reversal functions, strong dependence of blood flow reversal on natural pressure differentials, and a high risk of vascular injury and plaque detachment. Summary of the Invention

[0005] Therefore, it is necessary to provide a catheter assembly, a dilating sheath, and a transfemoral artery access system to address at least one of the aforementioned technical problems.

[0006] This application provides a catheter assembly, the catheter assembly comprising:

[0007] Internal catheter; An outer sheath is fitted over the inner conduit, and the gap between the outer sheath and the inner conduit forms a fluid channel; the outer sheath includes a fixed-diameter section and a variable-diameter section along its axial direction, the variable-diameter section being located at the distal end of the fixed-diameter section, and the variable-diameter section having radial deformation capability. A sealing part is disposed at the distal end of the outer sheath tube, and the sealing part has a contracted state and an expanded state.

[0008] In one embodiment, the inner catheter comprises, from the inside out, an outer inner tube layer, an inner tube support layer, and an inner inner tube layer, which are stacked and nested sequentially; and / or, The fixed-diameter section of the outer sheath comprises, from the inside out, a sheath outer layer, a sheath support layer, and a sheath inner layer, stacked sequentially; and / or, The outer sheath is connected to the inner catheter; and / or, The outer sheath is eccentrically positioned relative to the inner catheter, and the inner wall of the outer sheath is linearly connected to the outer wall of the inner catheter along the axial direction; and / or, The fluid channel is configured for blood flow; and / or, The lumen of the inner catheter is configured for the passage of a medical device; and / or, The catheter assembly includes a reflux component connected to at least one of the outer sheath and the inner catheter, and the lumen of the reflux component is in communication with the fluid channel.

[0009] In one embodiment, the variable diameter tube segment includes an inner sheath and an outer sheath, the outer sheath being sleeved over the inner sheath, forming a first deformation cavity between the inner and outer sheaths; at least one of the inner conduit and the outer sheath has an infusion channel communicating with the first deformation cavity; and / or, The maximum deformation of the outer diameter of the variable-diameter pipe section is less than or equal to the outer diameter of the fixed-diameter pipe section; and / or The minimum deformation of the outer diameter of the variable diameter pipe section is smaller than that of the outer diameter of the fixed pipe section.

[0010] In one embodiment, a first connection structure is provided between the inner sleeve and the outer sleeve; and / or, The catheter assembly includes an injection component connected to at least one of the outer sheath and the inner catheter, and the lumen of the injection component communicates with the perfusion channel.

[0011] In one embodiment, the plugging portion has a through-hole, the plugging portion is sleeved on the outside of the inner catheter, and the proximal end of the plugging portion is connected to the outer sheath, the tube layer gap between the plugging portion and the inner catheter is in communication with the fluid channel; and / or, The sealing part is configured as a deformable balloon.

[0012] In one embodiment, the sealing portion includes an outer sheath and an inner sheath, with a second deformation cavity formed between the inner sheath and the outer sheath; at least one of the inner catheter and the outer sheath has an infusion channel communicating with the second deformation cavity; and / or, The maximum deformation of the outer diameter of the sealing part is greater than the outer diameter of the fixed pipe section; and / or The minimum deformation dimension of the outer diameter of the sealing part is smaller than the outer diameter of the fixed pipe section; and / or, In the direction from distal to proximal, the inner diameter of at least a portion of the cavity of the sealing portion in an expanded state gradually decreases; and / or, In the direction from the distal end to the proximal end, the outer diameter of the sealing part in the expanded state exhibits a structure that gradually decreases and then gradually increases.

[0013] In one embodiment, a second connecting structure is provided between the inner sleeve and the outer sleeve; and / or, The catheter assembly includes an injection component connected to at least one of the outer sheath and the inner catheter, and the lumen of the injection component communicates with the infusion channel; and / or, The outer sleeve is made of a compliant material; and / or, The inner sleeve is made of a non-compliant material.

[0014] This application provides an expansion sheath that includes the catheter assembly.

[0015] This application provides a transfemoral artery access system, the transfemoral artery access system comprising: The expanding sheath; Venous sheath; A drive device is disposed between the dilating sheath and the venous sheath.

[0016] In one embodiment, the transfemoral artery access system includes: A filtration device is disposed between the dilating sheath and the venous sheath; and / or, A first expander, configured to cooperate with the expander sheath; and / or A second dilator is configured to cooperate with the venous sheath.

[0017] The catheter assembly, dilating sheath, and femoral artery access system provided by this invention have the following advantages: In the aforementioned catheter assembly, dilating sheath, and femoral artery access system, the lumen of the inner catheter forms one channel, while the fluid channel between the outer sheath and the inner catheter belongs to another. The lumen of the inner catheter can be used for the passage of medical devices, and the fluid channel allows for blood flow. This separates the blood flow channel and the medical device delivery channel into two distinct channels, achieving separation of blood flow and device delivery. By utilizing these two channels to perform different functions, the obstruction of blood flow by the delivery device can be fundamentally avoided, thus solving the problems of limited cross-sectional area of ​​the blood flow reversal channel and the mutual constraint between device delivery and reversal functions. Moreover, based on the radial deformation capability of the deformable segment, the variable diameter segment can maintain a small radial dimension when not radially dilated. When the dilating sheath is inserted into the femoral artery, the distal variable diameter segment can maintain a small radial dimension, thereby reducing mechanical stimulation to the vessel wall and lowering the risk of vascular injury and plaque detachment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the components of a femoral artery access system provided in one embodiment of this application; Figure 2 This is a schematic diagram of the usage status of a transfemoral artery access system provided in one embodiment of this application; Figure 3 A partially enlarged view of the use of a transfemoral artery access system provided in one embodiment of this application; Figure 4 A schematic diagram of the state of an expansion sheath provided in one embodiment of this application; Figure 5 This is a schematic diagram of another state of the dilated sheath provided in one embodiment of this application; Figure 6 For example Figure 5 The axial cross-sectional view of the expansion sheath shown; Figure 7 For example Figure 6 A partially enlarged cross-sectional view of the expansion sheath shown; Figure 8 For example Figure 6 A partially enlarged cross-sectional view of blood flow within the dilating sheath shown; Figure 9 For example Figure 6 A partially enlarged cross-sectional view of the fluid injection state in the dilation sheath shown; Figure 10 A perspective sectional view of the location of the variable diameter tube section in an expansion sheath provided in one embodiment of this application; Figure 11 A perspective sectional view showing the location of a fixed-diameter tube section in an expansion sheath according to an embodiment of this application; Figure 12This is a perspective cross-sectional view of the location of the sealing portion in an expansion sheath provided in one embodiment of this application.

[0019] In the picture: 100. Dilatation sheath; 200. Intravenous sheath; 300. Drive mechanism; 400. Filtering device; 500. First dilator; 600. Second dilator; 1000, Inner catheter; 2000, Outer sheath; 3000, Return device; 4000, Injection device; 2010, Fluid Channel; 2020, Infusion Channel; 2100, Fixed diameter pipe section; 2200, Reducing diameter pipe section; 2300, Sealing section; 2201, First deformable cavity; 2210, Outer sleeve; 2220, Inner sleeve; 2230, First connecting structure; 2301, Second deformable cavity; 2310, Outer sleeve; 2320, Inner sleeve; 2330, Second connecting structure. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0026] To more clearly describe the structure of the catheter assembly, dilation sheath 100, and transfemoral artery access system provided in this application, the term "distal" is defined herein as the end furthest from the operator during the surgical procedure, and "proximal" as the end closest to the operator during the surgical procedure. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0027] See Figure 1 As shown, this application provides a femoral artery access system, which includes components such as a dilating sheath 100, a venous sheath 200, a drive device 300, a filter device 400, a first dilator 500, and a second dilator 600. The drive device 300 is disposed between the dilating sheath 100 and the venous sheath 200, and the filter device 400 is also disposed between them. The first dilator 500 is configured to cooperate with the dilating sheath 100, and the second dilator 600 is configured to cooperate with the venous sheath 200.

[0028] like Figure 2 and Figure 3 As shown, during surgical procedures using the aforementioned femoral artery access system, the dilating sheath 100 can be inserted into the femoral artery, and the venous sheath 200 can be inserted into the femoral vein. During insertion, the first dilator 500 and the second dilator 600 are first used to puncture the femoral artery and femoral vein, establishing access with the help of a guidewire. Once the access is established, the dilating sheath 100 can be inserted into the femoral artery, and the venous sheath 200 can be inserted into the femoral vein, thereby enabling the following procedures: Figure 2 As shown, a reflux channel is established with the femoral vein.

[0029] The filtration device 400 can employ a filter screen or similar material to intercept plaque detached from the common carotid artery, preventing plaque from reaching the veins and causing pulmonary thrombosis. The drive device 300 can be a blood pump, such as a peristaltic pump, to actively drive blood through an external circuit from the carotid region to the femoral vein. The peristaltic pump includes a flow stabilizing device to ensure stable pumping. Based on an externally designed drive device 300, it effectively maintains the continuity of blood flow reversal, providing auxiliary driving force when the body's natural pressure differential is insufficient, and regulating the flow rate and stability of blood flow reversal. Therefore, active pumping reduces the dependence of blood flow reversal on the natural pressure differential, improving the system's applicability in patients with complex anatomy or hypotension.

[0030] It should be noted that, as Figure 1 The two dilatation sheaths 100 in the middle respectively show Figure 4 and Figure 5The diagram shows the expansion sheath 100 in two different states.

[0031] The aforementioned dilating sheath 100 is mainly constructed by connecting several tubing segments, comprising a catheter assembly consisting of the corresponding tubing segments. (See also...) Figures 4 to 7 As shown, the catheter assembly in the dilating sheath 100 may include an inner catheter 1000, an outer sheath 2000, and an occlusion portion 2300. The outer sheath 2000 is fitted over the inner catheter 1000, and the interlayer gap between the outer sheath 2000 and the inner catheter 1000 forms a fluid channel 2010. Therefore, the lumen of the inner catheter 1000 can form one channel, and the fluid channel 2010 between the outer sheath 2000 and the inner catheter 1000 is another channel. The fluid channel 2010 can be used to supply blood flow and remain patent during blood flow reversal. The lumen of the inner catheter 1000 can be used to allow medical devices to pass through, such as carotid artery stent delivery systems or other interventional devices.

[0032] Continue reading Figure 8 As shown, the fluid channel 2010 described above can be as follows: Figure 8 The arrows indicate the direction of blood flow, allowing the blood flow channel and the medical device delivery channel to belong to two separate channels, thus separating blood flow and device delivery. These two channels serve different functions, achieving separation of their respective roles. By implementing blood flow and medical device delivery through two separate channels, the obstruction of the reflux channel by device delivery is avoided, improving reflux efficiency and fundamentally preventing obstruction of blood flow by the delivery device. Compared to structures relying solely on reflux within the catheter lumen, this provides a larger reflux cross-sectional area without significantly increasing the outer diameter of the common carotid artery segment. This solves the problems of limited cross-sectional area in the blood flow reversal channel and the mutual constraint between device delivery and reflux functions, maintaining patency during blood flow reversal.

[0033] The catheter assembly may also include a reflux component 3000. At the structural assembly level, the reflux component 3000 may be connected to at least one of the outer sheath 2000 and the inner catheter 1000; at the access connection level, the lumen of the reflux component 3000 may be connected to the fluid channel 2010, thereby allowing blood to be diverted through the reflux component 3000.

[0034] Continue reading Figure 4 and Figure 5As shown, the outer sheath 2000 can be designed along its axial direction to include a fixed-diameter section 2100 and a variable-diameter section 2200. The variable-diameter section 2200 is located at the distal end of the fixed-diameter section 2100. The fixed-diameter section 2100 is a section with a fixed radial dimension, while the variable-diameter section 2200 is a section with radial deformation capability. The radial deformation capability of the variable-diameter section 2200 can be achieved by filling with gas, filling with liquid, or through metal memory. Those skilled in the art can design the implementation method of the radial deformation capability of the variable-diameter section 2200 according to actual needs, and no limitation is made here.

[0035] Based on the radial deformation capacity of the deformable tube segment, the maximum deformation of the outer diameter of the variable diameter tube segment 2200 can be limited to be less than or equal to the outer diameter of the fixed tube segment, and the minimum deformation of the outer diameter of the variable diameter tube segment 2200 can be less than the outer diameter of the fixed tube segment. Therefore, the variable diameter tube segment 2200 can maintain a small radial dimension when it is not radially expanded. At this time, when the dilating sheath 100 is inserted into the femoral artery, the distal variable diameter tube segment 2200 can maintain a small radial dimension, thereby reducing mechanical stimulation to the blood vessel wall and reducing the risk of vascular injury and plaque detachment. Until the dilating sheath 100 reaches the predetermined position, the distal variable diameter tube segment 2200 is actively controlled to expand radially, expanding the variable diameter tube segment 2200 to the same radial dimension as the fixed tube segment, restoring its proper radial dimension.

[0036] The sealing part 2300 is disposed at the distal end of the outer sheath 2000, and the sealing part 2300 has a contracted state and an expanded state. In this case, the maximum deformation of the outer diameter of the sealing part 2300 in the expanded state can be limited to be greater than the outer diameter of the fixed pipe section, and the minimum deformation of the outer diameter of the sealing part 2300 in the contracted state can be less than the outer diameter of the fixed pipe section. If the maximum deformation of the outer diameter of the reducing pipe section 2200 is limited to be less than or equal to the outer diameter of the fixed pipe section, then the minimum deformation of the outer diameter of the sealing part 2300 in the contracted state can also be designed to be approximately equivalent to the maximum deformation of the outer diameter of the reducing pipe section 2200, i.e., it can be greater than, less than, or equal to it. Those skilled in the art can design this according to actual needs, and no limitation is made here.

[0037] Therefore, the surgeon can actively control the contraction and expansion states of the occlusion unit 2300 during the procedure to achieve vascular occlusion at a predetermined location. For example, by using the expanded occlusion unit 2300 to adhere to the inner wall of the common carotid artery, the antegrade blood flow of the common carotid artery can be blocked, thereby providing conditions for blood flow reversal. Furthermore, the coordinated operation of the drive device 300 and the occlusion unit 2300 can be activated or adjusted after the occlusion is formed to achieve controlled cerebral blood flow reversal.

[0038] The contraction and expansion capabilities of the sealing part 2300 can be achieved by filling it with gas, filling it with liquid, or by using metal memory. Those skilled in the art can design the implementation of the contraction and expansion capabilities of the sealing part 2300 according to actual needs, and no limitation is made here.

[0039] The fluid channel 2010 formed between the outer sheath 2000 and the inner catheter 1000 needs to supply blood flow, thus requiring a stable flow path. Therefore, in one embodiment, the outer sheath 2000 may be directly or indirectly connected to the inner catheter 1000 to prevent changes in the flow path of the fluid channel 2010 due to relative movement between the outer sheath 2000 and the inner catheter 1000. This maintains a stable relative position between the outer sheath 2000 and the inner catheter 1000, ensuring that the fluid channel 2010 is always in a stable flow path, allowing blood to maintain a relatively constant flow rate.

[0040] The outer sheath 2000 and the inner catheter 1000 can be stably connected through a structure between their tubular layers, or through a proximal structure. Alternatively, the outer sheath 2000 and the inner catheter 1000 can be relatively eccentrically positioned, such as... Figure 10 and Figure 11 As shown, the inner wall of the outer sheath 2000 and the outer wall of the inner catheter 1000 are linearly connected along the axial direction. A stable connection between the outer sheath 2000 and the inner catheter 1000 is achieved through a direct sidewall connection. At this point, the interlayer gap between the outer sheath 2000 and the inner catheter 1000 can construct a fluid channel 2010 with a radially incomplete circular cross-section, allowing blood to flow through... Figure 10 and Figure 11 The fluid channel 2010 shown is in flow.

[0041] When the radial deformation capability of the reducing pipe section 2200 is achieved by filling it with gas, liquid, or other methods, the reducing pipe section 2200 can be designed with an internal cavity structure. Therefore, its radial dimension can be controlled by whether or not it is filled with gas or liquid. (Continue reading...) Figure 10 and Figure 11 As shown, in one embodiment, the variable diameter pipe section 2200 may include an inner sleeve 2220 and an outer sleeve 2210. The outer sleeve 2210 is sleeved outside the inner sleeve 2220, and the pipe layer gap between the inner sleeve 2220 and the outer sleeve 2210 can form a first deformation cavity 2201. The inner sleeve 2220 and the outer sleeve 2210 may be made of flexible materials; for example, the inner sleeve 2220 and the outer sleeve 2210 may have a thinner membrane structure.

[0042] Therefore, when the first deformable cavity 2201 is not filled with gas or liquid, the variable diameter tube segment 2200 is in a smaller radial dimension than the fixed diameter tube segment 2100. Based on the flexibility of the inner sheath 2220 and outer sheath 2210, they are tightly attached to the outer wall of the inner catheter 1000. At this time, the distal end of the fluid channel 2010 between the outer sheath 2000 and the inner catheter 1000 is approximately closed and not in a patent state. When the first deformable cavity 2201 is filled with gas or liquid, the variable diameter tube segment 2200 can then radially expand, transforming into a larger radial dimension that is essentially equal to the fixed diameter tube segment 2100. At this time, the distal end of the fluid channel 2010 between the outer sheath 2000 and the inner catheter 1000 is opened, making the fluid channel 2010 patent and serving as a blood flow reversal channel.

[0043] At least one of the inner catheter 1000 and the outer sheath 2000 may have an infusion channel 2020 communicating with the first deformable cavity 2201. For example, the infusion channel 2020 may be formed in the wall of the inner catheter 1000 or in the wall of the outer sheath 2000. Alternatively, when the walls of the inner catheter 1000 and the outer sheath 2000 are connected, the infusion channel 2020 may also be formed at the position of the wall where the inner catheter 1000 and the outer sheath 2000 are connected. No limitation is made here.

[0044] The infusion channel 2020 can be used to inject gas or liquid externally, allowing the gas or liquid to be injected into the first deformable cavity 2201 through the infusion channel 2020, controlling the radial expansion of the variable diameter tube section 2200, converting it into a state with a larger radial dimension that is substantially equal to that of the fixed diameter tube section 2100. The catheter assembly includes an injection component 4000, which is connected to at least one of the outer sheath 2000 and the inner catheter 1000, and the inner lumen of the injection component 4000 communicates with the infusion channel 2020, allowing the injection of gas or liquid through the inner lumen of the injection component 4000.

[0045] Those skilled in the art can design the dimensions of the inner sleeve 2220 and the outer sleeve 2210, as well as the shape and dimensions of the first deformable cavity 2201 formed between the inner sleeve 2220 and the outer sleeve 2210, according to actual needs, without limitation. In addition, those skilled in the art can also use other structural designs for the variable diameter pipe section 2200, without limitation.

[0046] Continue reading Figure 10As shown, in one embodiment, a first connecting structure 2230 may be provided between the inner sheath 2220 and the outer sheath 2210. The first connecting structure 2230 can connect the inner sheath 2220 and the outer sheath 2210. Therefore, when the first deformable cavity 2201 is filled with gas or liquid, when the outer sheath 2210 expands radially relative to the inner sheath 2220, it can also pull the inner sheath 2220 radially to expand together after expanding to a certain extent. This can avoid the inner sheath 2220 from collapsing radially inward. As a result, a stable channel that can communicate with the fluid channel 2010 is also formed in the gap between the variable diameter tube section 2200 and the inner catheter 1000, allowing blood flow to pass through stably.

[0047] The first connecting structure 2230 can adopt a variety of structural designs. For example, the first connecting structure 2230 can adopt an axially extending connecting strip, and the connecting strip can be continuous or intermittent when extending axially. The connecting strip connects the inner sleeve 2220 and the outer sleeve 2210, and multiple connecting strips can be arranged circumferentially at intervals or in a spiral arrangement between the inner sleeve 2220 and the outer sleeve 2210. Alternatively, the first connecting structure 2230 can also adopt a regular or irregular point-like distributed distribution or a mesh structure, etc.

[0048] When using circumferentially spaced connecting strips, 3 to 15 connecting strips can be selected circumferentially to ensure circumferential tensile strength. After folding, they must fit tightly around the inner conduit 1000, preventing an excessively large outer diameter after bonding due to an excessive number of strips. For a spiral arrangement, 2 to 6 connecting strips can be designed. The connecting strip material can be Pebax (polyether block amide elastomer) 45D–55D or TPU (thermoplastic polyurethane) / Pebax (polyether block amide elastomer) 25D–35D. The connecting strips can be connected to the inner sleeve 2220 and outer sleeve 2210 by hot welding, hot pressing, or local melting. Those skilled in the art can design according to actual needs, and no limitations are imposed here. This structure can significantly improve resistance to radial collapse and maintain the unobstructed flow of the fluid channel 2010 under negative pressure backflow or pumping conditions.

[0049] The occlusion portion 2300 can adopt various structures capable of contraction and expansion, such as a deformable balloon, a mesh structure, or a covered stent structure, etc., and is not limited thereto. In one embodiment, the occlusion portion 2300 can adopt a spherical structure, and the occlusion portion 2300 has an axially penetrating inner cavity in the middle. In this case, the occlusion portion 2300 can be sleeved on the outside of the inner catheter 1000, and the proximal end of the occlusion portion 2300 is connected to the outer sheath 2000, located at the distal end of the outer sheath 2000, so that the interlayer gap between the occlusion portion 2300 and the inner catheter 1000 also forms an annular channel, which communicates with the fluid channel 2010 to supply blood flow. Preferably, the proximal end of the occlusion portion 2300 can be connected to the reducing diameter section 2200 of the outer sheath 2000.

[0050] In the direction from distal to proximal, when the sealing portion 2300 is in an expanded state, at least a portion of the inner diameter of the cavity wall in the middle of the sealing portion 2300 can be designed to gradually decrease. Simultaneously, in the direction from distal to proximal, when the sealing portion 2300 is in an expanded state, the outer diameter in the middle of the sealing portion 2300 can be designed to first gradually decrease and then gradually increase, constructing a roughly funnel shape. Therefore, based on the structural design of the sealing portion 2300, blood can smoothly transition when entering the fluid channel 2010 and reversing blood flow, reducing local flow resistance and turbulence generation, ensuring smooth blood flow, and preventing reverse pressure on the reversal channel after adhering to the wall. In addition, those skilled in the art can design the shape and size of the sealing portion 2300 according to actual needs, which is not limited here.

[0051] When the contraction and expansion capabilities of the sealing part 2300 are achieved by filling it with gas, liquid, or other means, the sealing part 2300 can be designed with an internal cavity structure. Therefore, its radial dimensions can be controlled by whether or not it is filled with gas or liquid. (Continue reading...) Figure 12 As shown, in one embodiment, the sealing portion 2300 includes an outer sleeve 2310 and an inner sleeve 2320, with a second deformable cavity 2301 formed between the inner sleeve 2320 and the outer sleeve 2310. The inner sleeve 2320 and the outer sleeve 2310 may be made of flexible materials; for example, the inner sleeve 2320 and the outer sleeve 2310 may also employ a thinner membrane structure.

[0052] Therefore, when the second deformable cavity 2301 is not filled with gas or liquid, the sealing part 2300 is in a smaller radial dimension than the fixed diameter tube section 2100. Based on the flexibility of the inner sleeve 2320 and the outer sleeve 2310, the inner sleeve 2320 and the outer sleeve 2310 are tightly attached to the outer wall of the inner catheter 1000. At this time, the tube layer gap between the sealing part 2300 and the inner catheter 1000 is roughly closed and is not in a smooth state. When the second deformable cavity 2301 is filled with gas or liquid, the sealing part 2300 can be radially expanded, changing to a larger radial dimension than the fixed diameter tube section 2100. At this time, the tube layer gap between the sealing part 2300 and the inner catheter 1000 is opened, which can be used to connect the fluid channel 2010, so that the fluid channel 2010 is in a smooth state, serving as a blood flow reversal channel.

[0053] The outer sheath 2310 can be made of a compliant material, while the inner sheath 2320 can be made of a non-compliant material. The compliant outer sheath 2310 better conforms to the blood vessel, while the non-compliant inner sheath 2320 ensures the stability of the blood flow cavity. The inner sheath 2320 and the outer sheath 2310 can be connected by methods such as hot welding, hot pressing, or local melting, which are not limited here.

[0054] At least one of the inner catheter 1000 and the outer sheath 2000 may have an infusion channel 2020 communicating with the second deformable cavity 2301. For example, the infusion channel 2020 may be formed in the wall of the inner catheter 1000 or in the wall of the outer sheath 2000. Alternatively, when the walls of the inner catheter 1000 and the outer sheath 2000 are connected, the infusion channel 2020 may also be formed at the position of the wall where the inner catheter 1000 and the outer sheath 2000 are connected. No limitation is made here.

[0055] The infusion channel 2020 can be used to inject gas or liquid externally, allowing the gas or liquid to be injected into the second deformable cavity 2301 through the infusion channel 2020, controlling the radial expansion of the sealing part 2300, and converting it into a larger radial dimension state than the fixed diameter tube section 2100. The catheter assembly also includes an injection component 4000, which is connected to at least one of the outer sheath 2000 and the inner catheter 1000, and the inner lumen of the injection component 4000 communicates with the infusion channel 2020, allowing gas or liquid to be injected through the inner lumen of the injection component 4000.

[0056] like Figures 4 to 6As shown, when the reducing pipe section 2200 is located at the distal end of the fixed pipe section 2100, and the sealing part 2300 is located at the distal end of the reducing pipe section 2200, the injection channel 2020 can first connect to the first deformation cavity 2201 of the reducing pipe section 2200 from the proximal end to the distal end, and then indirectly connect to the second deformation cavity 2301 via the first deformation cavity 2201. At this time, gas or liquid can be injected into the first deformation cavity 2201 and the second deformation cavity 2301 simultaneously using one injection channel 2020, thereby achieving radial expansion of the reducing pipe section 2200 and the sealing part 2300.

[0057] Those skilled in the art can design the dimensions of the inner sleeve 2320 and the outer sleeve 2310, as well as the shape and dimensions of the second deformable cavity 2301 formed between the inner sleeve 2320 and the outer sleeve 2310, according to actual needs, without limitation. Alternatively, those skilled in the art can also use other structural designs for the sealing part 2300, without limitation.

[0058] Continue reading Figure 12 As shown, in one embodiment, a second connecting structure 2330 is provided between the inner sleeve 2320 and the outer sleeve 2310. The second connecting structure 2330 can connect the inner sleeve 2320 and the outer sleeve 2310. Therefore, when the second deformable cavity 2301 is filled with gas or liquid, and the outer sleeve 2310 expands radially relative to the inner sleeve 2320, it can also pull the inner sleeve 2320 radially to expand together after expanding to a certain extent. This can avoid the inner sleeve 2320 from collapsing radially inward. As a result, a stable channel that can communicate with the fluid channel 2010 is also formed in the gap between the sealing part 2300 and the inner catheter 1000, allowing blood to pass through stably.

[0059] The second connecting structure 2330 can adopt a variety of structural designs. For example, the second connecting structure 2330 can use an axially extending connecting strip, which can be continuous or intermittent during its axial extension. The connecting strip connects the inner sleeve 2320 and the outer sleeve 2310, and multiple connecting strips can be arranged circumferentially at intervals or in a spiral arrangement between the inner sleeve 2320 and the outer sleeve 2310. Alternatively, the second connecting structure 2330 can also adopt a regular or irregular point-like distributed pattern or a mesh structure, etc.

[0060] When using circumferentially spaced connecting strips, 3 to 15 connecting strips can be selected circumferentially to ensure circumferential tensile strength. This ensures a tight fit around the inner conduit 1000 after folding, preventing excessive outer diameter due to an excessive number of strips. For a spiral arrangement, 2 to 6 connecting strips can be designed. The connecting strip material can be Pebax (polyether block amide elastomer) 45D–55D or TPU (thermoplastic polyurethane) / Pebax (polyether block amide elastomer) 25D–35D. The connecting strips can be connected to the inner sleeve 2320 and outer sleeve 2310 through methods such as hot welding, hot pressing, or local melting. Those skilled in the art can design according to actual needs, and no limitations are imposed here. This structure significantly improves resistance to radial collapse, maintaining the unobstructed flow of the fluid channel 2010 under negative pressure backflow or pumping conditions.

[0061] In one embodiment, the inner diameter of the inner catheter 1000 can be designed to be between 6.2 Fr and 7 Fr, and the wall thickness can be designed to be between 0.5 Fr and 1.5 Fr. The inner catheter 1000 may include an outer inner tube layer, an inner tube support layer, and an inner inner tube layer stacked sequentially from the inside out. The material of the outer inner tube layer can be selected from polymer materials such as PA (polyamide), PEBAX (polyether block amide elastomer series), and HDPE (high-density polyethylene). The material of the inner inner tube layer can be selected from PTFE (polytetrafluoroethylene) material with low friction value to ensure instrument passage. The inner tube support layer may have a metal braided layer, which can resist bending and collapse and provide torque transmission capability.

[0062] The inner catheter 1000 may be equipped with a vascular detection access switch for connection to the fluid channel 2010, ensuring blood flow through the lumen of the inner catheter 1000 even when no instrument is inserted, thus guaranteeing blood flow. It can also be used to confirm whether blood flows into the fluid channel 2010 after radial expansion of the occlusion section 2300 and the reducing section 2200, preventing situations where the occlusion section 2300 and the reducing section 2200 fail to expand radially due to instrument issues, resulting in blood flow only into the lumen of the inner catheter 1000. In such a case, if an instrument is inserted, there will be no blood outflow, leading to reverse blood flow in the external carotid artery. If plaque detaches from the internal carotid artery at this time, it will flow into the external carotid artery, potentially causing facial paralysis.

[0063] In one embodiment, the inner diameter of the fixed-diameter section 2100 of the outer sheath 2000 can be designed to be between 10Fr and 15Fr, and the wall thickness of the fixed-diameter section 2100 can be designed to be between 0.5Fr and 1.5Fr. The fixed-diameter section 2100 may comprise an outer sheath layer, a sheath support layer, and an inner sheath layer, stacked sequentially from the inside out. The materials for the outer and inner sheath layers can be selected from polymer materials such as PA (polyamide), PEBAX (polyether block amide elastomer series), and HDPE (high-density polyethylene). The sheath support layer may include a metal braided layer, which can resist bending and collapse and provide torque transmission capability.

[0064] The reducing pipe section 2200 of the outer sheath 2000 can be made of materials such as Pebax 55D–72D, Pebax + fiber-reinforced composite membrane (PET fiber or UHMWPE fiber), Nylon (PA), or other low-compliance or non-compliance materials. The inner sleeve 2220 and the outer sleeve 2210 of the reducing pipe section 2200 can be connected by means of hot welding, hot pressing, or local melting.

[0065] In one embodiment, the outer diameter of the occlusion portion 2300 in its expanded state can be selected according to the anatomical dimensions of the common carotid artery, for example, designed to be between 10 mm and 12 mm to match the size of the common carotid artery in adults. The outer sheath 2310 of the occlusion portion 2300 can be made of compliant materials such as TPU, low-hardness Pebax (25D–35D), or silicone, while the inner sheath 2320 of the occlusion portion 2300 can be made of compliant materials such as TPU or low-hardness Pebax (25D–35D) or non-compliant materials such as Pebax 55D–72D, Pebax + fiber-reinforced composite membrane (PET fiber or UHMWPE fiber), or Nylon (PA).

[0066] 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.

[0067] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively 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 this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A catheter assembly, characterized in that, The catheter assembly includes: Internal catheter; An outer sheath is fitted over the inner conduit, and the gap between the outer sheath and the inner conduit forms a fluid channel; the outer sheath includes a fixed-diameter section and a variable-diameter section along its axial direction, the variable-diameter section being located at the distal end of the fixed-diameter section, and the variable-diameter section having radial deformation capability. A sealing part is disposed at the distal end of the outer sheath tube, and the sealing part has a contracted state and an expanded state.

2. The catheter assembly according to claim 1, characterized in that, The inner conduit comprises, from the inside out, an outer inner tube layer, an inner tube support layer, and an inner inner tube layer, stacked sequentially; and / or, The fixed-diameter section of the outer sheath comprises, from the inside out, a sheath outer layer, a sheath support layer, and a sheath inner layer, stacked sequentially; and / or, The outer sheath is connected to the inner catheter; and / or, The outer sheath is eccentrically positioned relative to the inner catheter, and the inner wall of the outer sheath is linearly connected to the outer wall of the inner catheter along the axial direction; and / or, The fluid channel is configured for blood flow; and / or, The lumen of the inner catheter is configured for the passage of a medical device; and / or, The catheter assembly includes a reflux component connected to at least one of the outer sheath and the inner catheter, and the lumen of the reflux component is in communication with the fluid channel.

3. The catheter assembly according to claim 1, characterized in that, The variable diameter tubing section includes an inner sheath and an outer sheath, the outer sheath being fitted over the inner sheath, forming a first deformation cavity between the inner and outer sheaths; at least one of the inner conduit and the outer sheath has an infusion channel communicating with the first deformation cavity; and / or, The maximum deformation of the outer diameter of the variable-diameter pipe section is less than or equal to the outer diameter of the fixed-diameter pipe section; and / or The minimum deformation of the outer diameter of the variable diameter pipe section is smaller than that of the outer diameter of the fixed pipe section.

4. The catheter assembly according to claim 3, characterized in that, A first connection structure is provided between the inner sleeve and the outer sleeve; and / or, The catheter assembly includes an injection component connected to at least one of the outer sheath and the inner catheter, and the lumen of the injection component communicates with the perfusion channel.

5. The catheter assembly according to claim 1, characterized in that, The plugging portion has a through-hole, the plugging portion is sleeved on the outside of the inner catheter, and the proximal end of the plugging portion is connected to the outer sheath. The gap between the plugging portion and the inner catheter is in communication with the fluid channel; and / or, The sealing part is configured as a deformable balloon.

6. The catheter assembly according to claim 5, characterized in that, The sealing portion includes an outer sheath and an inner sheath, with a second deformation cavity formed between the inner sheath and the outer sheath; at least one of the inner catheter and the outer sheath has an infusion channel communicating with the second deformation cavity; and / or, The maximum deformation of the outer diameter of the sealing part is greater than the outer diameter of the fixed pipe section; and / or The minimum deformation dimension of the outer diameter of the sealing part is smaller than the outer diameter of the fixed pipe section; and / or, In the direction from distal to proximal, the inner diameter of at least a portion of the cavity of the sealing portion in an expanded state gradually decreases; and / or, In the direction from the distal end to the proximal end, the outer diameter of the sealing part in the expanded state exhibits a structure that gradually decreases and then gradually increases.

7. The catheter assembly according to claim 6, characterized in that, A second connecting structure is provided between the inner sleeve and the outer sleeve; and / or, The catheter assembly includes an injection component connected to at least one of the outer sheath and the inner catheter, and the lumen of the injection component communicates with the infusion channel; and / or, The outer sleeve is made of a compliant material; and / or, The inner sleeve is made of a non-compliant material.

8. An expanding sheath, characterized in that, The dilating sheath comprises a catheter assembly as described in any one of claims 1-7.

9. A transfemoral artery access system, characterized in that, The femoral artery access system includes: The dilating sheath as described in claim 8; Venous sheath; A drive device is disposed between the dilating sheath and the venous sheath.

10. The femoral artery access system according to claim 9, characterized in that, The femoral artery access system includes: A filtration device is disposed between the dilating sheath and the venous sheath; and / or, A first expander, configured to cooperate with the expander sheath; and / or A second dilator is configured to cooperate with the venous sheath.

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