Expandable blood vessel sheath

Abstract

The present disclosure relates to an expandable vascular sheath. The expandable blood vessel sheath comprises a sheath tube capable of expanding in the radial direction, the sheath tube forms an instrument channel extending in the axial direction, and the sheath tube comprises an extending tube section and a tip tube section which are connected in the axial direction; the far end part of the extension tube section is connected to the near end part of the tip tube section; the tip pipe section comprises a first middle layer, a pre-cutting groove is formed in the inner wall of the first middle layer and extends from the near end of the tip pipe section to the far end close to the tip pipe section, the distance between the pre-cutting groove and the far end of the tip pipe section is larger than zero, and the depth of the pre-cutting groove is smaller than the thickness of the first middle layer. The outer wall of the tip tube section of the sheathing canal keeps axial and axial integrity, so that the far end part of the tip tube section has enough strength when entering a blood vessel, and the far end part of the tip tube section is prevented from wrinkling and cracking in advance when entering a human body; due to the design of the pre-cutting groove, the tip tube section can be evenly cracked when the valve extends out of the sheathing canal, and the valve can smoothly extend out of and retract back from the tip tube section.

Description

Technical Field

[0001] The present disclosure relates to the technical field of medical devices, and in particular to an expandable vascular sheath. Background Art

[0002] With the continuous development of science, the improvement of medical devices and operation techniques, and the more in-depth study of related medical mechanisms, transcatheter implantation is increasingly being used in clinical practice. In recent years, researchers have been committed to performing artificial heart valve replacement without opening the chest cavity or placing the patient on extracorporeal circulation, striving to minimize trauma. Existing transcatheter valve replacement technology has significantly reduced the trauma of surgery to patients. When performing transcatheter valve replacement surgery, a vascular sheath must first be inserted into the femoral artery or other arteries and veins of the human body to establish a vascular access so that the device can enter the human body through the established access; on the other hand, the vascular sheath plays a role in stopping bleeding throughout the operation.

[0003] When the current expandable vascular sheath establishes a passage in a blood vessel, the tip of the expandable vascular sheath first enters the blood vessel, and the valve device is closely attached to the expandable vascular sheath when passing through the passage, and finally extends from the tip. However, in order to facilitate the extension and retraction of the valve device from the tip, the existing expandable vascular sheath has an opening or slit at the tip, which causes wrinkles or obstruction when the tip of the expandable vascular sheath enters the blood vessel. Summary of the invention

[0004] Based on this, in order to solve the above problems, it is necessary to provide an expandable vascular sheath.

[0005] An embodiment of the present disclosure provides an expandable vascular sheath, which includes a radially expandable sheath tube, the sheath tube forming an instrument channel extending axially, the sheath tube including an extension tube segment and a tip tube segment connected along the axial direction; the distal end of the extension tube segment is connected to the proximal end of the tip tube segment; the tip tube segment includes a first intermediate layer, the inner wall of the first intermediate layer is provided with a pre-cut groove, the pre-cut groove extends from the proximal end of the tip tube segment toward the distal end close to the tip tube segment and the distance between the pre-cut groove and the distal end of the tip tube segment is greater than zero, and the depth of the pre-cut groove is less than the thickness of the first intermediate layer.

[0006] In the expandable vascular sheath provided by the embodiment of the present disclosure, the tip tube section of the sheath first enters the blood vessel and then the partially extended tube section also enters the blood vessel to establish a passage, and the instrument can pass through the instrument channel and enter the human body from the tip tube section. The pre-cut groove is on the inner wall of the first middle layer of the tip tube section, extending from the proximal end of the tip tube section to the distal end of the tip tube section, so that the first middle layer of the tip tube section is continuous along the circumferential direction, avoiding wrinkles and premature cracking of the distal end of the tip tube section when entering the human body; due to the design of the pre-cut groove, the tip tube section of the valve is convenient for evenly splitting when the valve is extended out of the sheath, which is conducive to the valve being able to smoothly extend and retract from the tip tube section.

[0007] In some of these embodiments, the pre-cut groove extends from the proximal end of the tip tube segment to the middle of the tip tube segment.

[0008] With such a configuration, the middle to distal ends of the tip tube segment remain continuous in the circumferential direction, which can better prevent wrinkles and premature cracking of the tip tube segment when it enters the human body and reduce uneven cracking due to a shorter pre-cut groove or premature cracking due to a longer pre-cut groove when the valve extends from the tip tube segment.

[0009] In some of the embodiments, the extended pipe segment includes an outer layer, a second intermediate layer and an inner lining stacked in sequence along the radial direction; the extended pipe segment includes an expandable segment and a variable diameter segment connected in sequence from the distal end to the proximal end, and the outer diameter of the variable diameter segment is larger than the outer diameter of the expandable segment; the strength of the material of the second intermediate layer corresponding to the expandable segment is smaller than the strength of the material of the second intermediate layer corresponding to the variable diameter segment, and the strength of the material of the second intermediate layer corresponding to the variable diameter segment gradually decreases along the axial direction toward the expansion segment.

[0010] With this arrangement, the outer diameter of the expandable section is smaller than that of the variable section, so that the variable section has a smaller diameter, which facilitates the variable section to enter the blood vessel more smoothly while reducing damage to the blood vessel wall. The material strength of the second intermediate layer at different positions is different, and the gradual strength setting of the variable section ensures that the sheath in the blood vessel is excessively smooth and has no steps while maintaining softness and not easily damaging the blood vessel, so that the sheath has better support and passability, which is convenient for the valve and the instrument to pass through.

[0011] In some of the embodiments, a proximal end of the first intermediate layer is connected to a distal end of the second intermediate layer, and a strength of a material of the first intermediate layer is greater than a strength of a material of the second intermediate layer corresponding to the expandable segment.

[0012] In this configuration, the strength of the material of the first intermediate layer is greater than the strength of the material of the second intermediate layer, which can avoid the generation of wrinkles and facilitate the sheath to enter the blood vessel better.

[0013] In some embodiments, the sheath has a first state of radial contraction and a second state of radial expansion; the second intermediate layer includes a first end and a second end arranged along the circumferential direction, the first end and the second end form a notch, and the notch extends axially; in the first state of the sheath, the first end radially overlaps with the outer side of the second end, and the direction of the notch is circumferential; in the second state of the sheath, the first end and the second end are distributed along the circumferential direction, and the direction of the notch is radial.

[0014] The setting of the notch enables the radial size of the second intermediate layer to change. The change in direction of the notch corresponds to the change in the state of the sheath. The first end and the second section overlap radially, so that the diameter of the sheath is reduced to facilitate the sheath to enter the blood vessel; the first end and the second end are distributed circumferentially to facilitate the expansion of the sheath.

[0015] In some of the embodiments, the expandable vascular sheath also includes a developing ring, which is installed at the distal end of the extended tube segment, and is located between the second intermediate layer and the inner lining. The developing ring has an opening, and the direction of the opening is consistent with the direction of the notch; the opening is set corresponding to the notch and the circumferential size of the opening is larger than the circumferential size of the notch.

[0016] With such a configuration, the opening direction of the developing ring is consistent with the direction of the notch, and the direction of the notch in the second intermediate layer can be determined by observing the opening, thereby confirming the direction of the local expansion of the sheath when the valve moves in the sheath, so as to better adjust the direction of the notch in the second intermediate layer, so that when the sheath bends, the direction of the notch in the second intermediate layer is always inward to avoid bending, further reducing damage to the blood vessel wall.

[0017] In some embodiments, the lining includes a first main body section abutting against the inner wall of the second intermediate layer and a first notch section connected to the inner wall of the first end and the inner wall of the second end; the outer layer includes a second main body section abutting against the outer wall of the second intermediate layer and a second notch section connected to the outer wall of the second end and the outer wall of the second intermediate layer; when the sheath is in the first state, the first notch section is located between the first end and the second end; when the sheath is in the second state, the first notch section, the first end and the second end form a circular ring shape.

[0018] With such a configuration, the first notch section can connect the two ends of the inner side of the notch together, ensuring that the outer periphery of the sheath is closed; the second notch section can connect the two ends of the outer side of the notch together, ensuring that the inner periphery of the sheath is closed, avoiding wrinkles caused by the notch when entering the blood vessel, effectively enhancing the sheath's anti-bending and anti-compression capabilities, and does not affect the expansion performance of the sheath, facilitating the change of the sheath state.

[0019] In some of the embodiments, the expansion section includes an insertion section and a transition section connected axially, the distal end of the transition section is connected to the proximal end of the insertion section; the strength of the material of the outer layer corresponding to the variable diameter section and the transition section is greater than the strength of the material of the outer layer corresponding to the insertion section; or the thickness of the outer layer corresponding to the variable diameter section and the transition section is greater than the thickness of the outer layer corresponding to the insertion section; or the transition section also includes a reinforcement layer, the inner wall of the reinforcement layer abuts against the outer wall of the outer layer.

[0020] Such a configuration increases the strength or thickness of the transition section and the diameter-changing section, thereby avoiding the risk of sheath bulging due to the pressure difference between the inside and outside of the body after the insertion section is inserted into the blood vessel.

[0021] In some of the embodiments, the material of the outer layer is a tough material; the outer wall of the outer layer has a hydrophilic coating; or the friction coefficient of the outer wall of the outer layer is less than 0.1.

[0022] With such a configuration, the hydrophilic coating or reduced friction coefficient prevents the sheath from being tight when entering and exiting the blood vessel, thereby reducing the difficulty of the operation and the damage to the blood vessel wall.

[0023] In some embodiments, the extension pipe section further includes a locking section, the distal end of the locking section is connected to the proximal end of the diameter-reducing section, and the outer diameter of the proximal end of the locking section gradually increases along the back of the diameter-reducing section;

[0024] The expandable vascular sheath also includes a hemostatic valve, a locking head and a three-way valve. The three-way valve is connected to the hemostatic valve. The hemostatic valve includes a connecting end and a fixed end. The outer wall of the connecting end abuts against the inner wall of the locking section. The proximal end of the locking head is fixed to the fixed end. The inner wall of the distal end of the locking head is circumferentially protruded with a plurality of bosses. The plurality of bosses are arranged axially, and the plurality of bosses abut against the outer wall of the locking section and part of the reducing section.

[0025] With this arrangement, the proximal end of the locking head tightens the fixed end. The multi-layer boss structure of the locking head increases the contact surface with the locking section and part of the reducing section. Each contact surface is subjected to different forces, which enables the locking section to tightly abut against the connecting end, further enhancing the tightness of the connection. The process is reliable and stable, making it difficult for the sheath to detach from the hemostatic valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the overall structure of the expandable vascular sheath in the embodiment of the present disclosure;

[0027] Figure 2 for Figure 1 Sectional view at point A;

[0028] Figure 3 is a schematic diagram of the overall structure of the tip tube segment in the embodiment of the present disclosure;

[0029] Figure 4 is a schematic diagram of the overall structure of the sheath tube in the embodiment of the present disclosure;

[0030] Figure 5 is a cross-sectional view of the sheath tube in the embodiment of the present disclosure;

[0031] Figure 6 It is a schematic cross-sectional view along the EE direction as shown in 4;

[0032] Figure 7 It is a partial structural schematic diagram of the extension pipe section and the development ring diagram in the embodiment of the present disclosure;

[0033] Figure 8 for Figure 1 Sectional view at B in the middle;

[0034] Fig. 9 for Figure 1 Sectional view at C in the middle;

[0035] Fig.10 for Figure 1 Cross-sectional view at point D in the middle.

[0036] Reference numerals:

[0037] 100. expandable vascular sheath; 1. sheath tube; 11. extension tube section; 111. expandable section; 1111. insertion section; 1112. transition section; 112. diameter-reducing section; 113. locking section; 101. outer layer; 1011. second main section; 1012. second notch section; 102. second intermediate layer; 1021. first end; 1022. second end; 1023. notch; 103. lining; 1031. first main section; 1032. first notch section; 12. tip tube section; 121. pre-cut groove; 104. first intermediate layer; 13. developing ring; 131. opening; 2. hemostatic valve; 21. connecting end; 22. fixed end; 3. locking head; 31. boss; 4. three-way valve. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present disclosure more obvious and understandable, the specific implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the embodiments of the present disclosure. However, the embodiments of the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the embodiments of the present disclosure, so the embodiments of the present disclosure are not limited by the specific embodiments disclosed below.

[0039] In the description of the embodiments of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present disclosure.

[0040] In the embodiments of the present disclosure, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. Exemplarily, the first intermediate layer may also be referred to as the second intermediate layer, and the second intermediate layer may also be referred to as the first intermediate layer. In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0042] In the embodiments of the present disclosure, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a flexible connection, or a rigid connection in at least one direction; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or a direct connection with the presence of an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. The terms "install", "set", "fixed" and the like can be broadly understood as connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0043] refer to Figure 1 , Figure 1 The side view of the overall structure of the expandable vascular sheath 100 in the embodiment of the present disclosure is shown. The present disclosure relates to the field of medical device technology. It should be noted that the distal end and the proximal end referred to in the present disclosure are based on the operator, the end close to the operator is the proximal end, and the end away from the operator is the distal end. The radial and axial directions in the present disclosure are based on the cross-sectional direction of the sheath tube 1.

[0044] Combination Figure 2 and Figure 3 The embodiment of the present disclosure provides an expandable vascular sheath 100, which includes a radially expandable sheath tube 1, and the sheath tube 1 forms an instrument channel extending in the axial direction. Exemplarily, the sheath tube 1 partially extends into a human blood vessel to establish a vascular access. At this time, the sheath tube 1 is in a contracted state, and subsequent valves and other instruments can enter the human body through the instrument channel. At this time, the sheath tube 1 is in an expanded state. Establishing a vascular access through the sheath tube 1 can reduce trauma to the human body.

[0045] The sheath tube 1 includes an extension tube segment 11 and a tip tube segment 12 connected in the axial direction. The distal end of the extension tube segment 11 is connected to the proximal end of the tip tube segment 12. Exemplarily, the distal end of the tip tube segment 12 first enters the human body away from the operator, and after the tip tube segment 12 completely enters the human body, the distal end of the extension tube segment 11 enters the human body accordingly. The tip tube segment 12 includes a first intermediate layer 104, and the inner wall of the first intermediate layer 104 is provided with a pre-cut groove 121, the pre-cut groove 121 extends from the proximal end of the tip tube segment 12 toward the distal end close to the tip tube segment 12, and the distance between the pre-cut groove 121 and the distal end of the tip tube segment 12 is greater than zero, and the depth of the pre-cut groove 121 is less than the thickness of the first intermediate layer 104.

[0046] In the expandable vascular sheath 100 provided in the embodiment of the present disclosure, the tip tube segment 12 of the sheath tube 1 first enters the blood vessel and then the partially extended tube segment 11 also enters the blood vessel to establish a passage, and the instrument can pass through the instrument channel and enter the human body from the tip tube segment 12. The pre-cut groove 121 is on the inner wall of the first intermediate layer 104 of the tip tube segment 12, extending from the proximal end of the tip tube segment 12 to the distal end of the tip tube segment 12, so that the first intermediate layer 104 of the tip tube segment 12 is continuous along the circumferential direction. Therefore, the outer wall of the tip tube segment 12 of the sheath tube 1 maintains axial and axial integrity, so that the inserted dilator can be tightly attached to the distal end of the tip tube segment 12, so that the distal end of the tip tube segment 12 has sufficient strength when entering the blood vessel, avoiding wrinkles caused by the incompleteness of the outer wall of the tip tube segment 12.

[0047] Furthermore, when the instrument moves in the instrument channel and finally extends from the distal end of the tip tube segment 12, the tip tube segment 12 will be torn when extending. The thickness of the pre-cut groove 121 of the second intermediate layer 102 is smaller than the thickness of other parts, so when the tip tube segment 12 is subjected to force from the inside, the pre-cut groove 121 is torn first, which facilitates the uniform splitting of the tip tube segment 12 and facilitates the smooth extension and retraction of the instrument. In addition, the design of the pre-cut groove 121 prevents the tip tube segment 12 from being torn more due to the incomplete outer wall of the tip tube segment 12 when entering the blood vessel, thereby preventing the sheath tube 1 from being difficult to enter the blood vessel and causing greater damage to the blood vessel after entering the blood vessel, resulting in the instrument being unable to be smoothly extended and retracted from the tip tube segment 12.

[0048] Exemplarily, the outer diameter of the extension tube section 11 changes from the proximal end to the distal end. The diameter of the tip tube section 12 gradually decreases from the proximal end to the distal end. The outer wall surface of the tip tube section 12 is a conical surface.

[0049] Exemplarily, the depth of the pre-cut groove 121 is half the thickness of the first intermediate layer 104. In other embodiments, the depth of the pre-cut groove 121 is less than half the thickness of the first intermediate layer 104; or the depth of the pre-cut groove 121 is greater than half the thickness of the first intermediate layer 104 and less than the thickness of the first intermediate layer 104.

[0050] Exemplarily, the pre-cut groove 121 is square in shape, and the axial dimension of the pre-cut groove 121 is much larger than the circumferential dimension of the pre-cut groove 121. In other embodiments, the axial dimension of the pre-cut groove 121 may be equal to the circumferential dimension of the pre-cut groove 121.

[0051] refer to Figure 2 and Figure 3 In some embodiments, the pre-cut groove 121 extends from the proximal end of the tip tube segment 12 to the middle of the tip tube segment 12. In this way, the tip tube segment 12 is continuous from the middle to the distal end in the circumferential direction, which can better prevent the tip tube segment 12 from wrinkling and premature cracking when entering the human body, and reduce the uneven cracking caused by the short pre-cut groove 121 or the premature cracking caused by the long pre-cut groove 121 when the valve extends from the tip tube segment 12.

[0052] In other embodiments, the ratio of the distance between the pre-cut groove 121 and the proximal end of the tip tube segment 12 to the tip tube segment 12 is less than 1 / 2. Or the ratio of the distance between the pre-cut groove 121 and the proximal end of the tip tube segment 12 to the tip tube segment 12 is greater than 1 / 2 and less than 1.

[0053] refer to Figure 1 , Figure 4 , Figure 5 and Figure 8 In some embodiments, the extension tube section 11 includes an outer layer 101, a second intermediate layer 102, and an inner liner 103 stacked in sequence along the radial direction. The extension tube section 11 includes an expandable section 111 and a reducing section 112 connected in sequence from the distal end to the proximal end, and the outer diameter of the reducing section 112 is larger than the outer diameter of the expandable section 111. The outer diameter of the expandable section 111 is smaller than the outer diameter of the reducing section 112, so that the reducing section 112 has a smaller diameter, which facilitates the reducing section 112 to enter the blood vessel more smoothly while reducing damage to the blood vessel wall.

[0054] The strength of the material of the second intermediate layer 102 corresponding to the expandable section 111 is less than the strength of the material of the second intermediate layer 102 corresponding to the diameter-reducing section 112, and the strength of the material of the second intermediate layer 102 corresponding to the diameter-reducing section 112 gradually decreases along the axial direction toward the expansion section. The material strengths of the second intermediate layer 102 at different positions are different, and the gradual strength setting of the diameter-reducing section 112 ensures that the outer layer 101 is excessively smooth and has no steps while the sheath tube 1 in the blood vessel remains soft and not easy to damage the blood vessel, so that the sheath tube 1 has better support and passability, which is convenient for the valve and the instrument to pass through. Since the thickness of the second intermediate layer 102 is greater than that of the outer layer 101 and the inner lining 103, the supporting performance of the second intermediate layer 102 is better than that of the outer layer 101 and the inner lining 103. The deformation of the second intermediate layer 102 can drive the deformation of the outer layer 101 and the inner lining 103. Therefore, compared with changing the material strength of the outer layer 101 or the inner lining 103, changing the material strength of the second intermediate layer 102 can greatly improve the performance and operability of the sheath 1 itself, ensure the integrity and smoothness of the outer layer 101, make it easier for the sheath 1 to move in the blood vessel and further reduce damage to the blood vessel.

[0055] Exemplarily, the material of the second middle layer 102 can be selected from soft plastic materials, such as polyether block polyamide (Pebax), thermoplastic polyurethane elastomer (TPU), etc.

[0056] For example, the inner lining 103 may be made of a relatively lubricating material, such as polyethylene (PE), polytetrafluoroethylene (PTFE), etc., so that the medical device can pass smoothly through the channel.

[0057] refer to Figure 5 , Figure 6 , Figure 8 , Fig. 9 and Fig.10 By way of example, materials of different strengths of the second intermediate layer 102 are represented as different hatching lines in the figure.

[0058] refer to Figure 5 In some embodiments, the proximal end of the first intermediate layer 104 is connected to the distal end of the second intermediate layer 102, and the strength of the material of the first intermediate layer 104 is greater than the strength of the material of the second intermediate layer 102 corresponding to the expandable segment 111. In this way, the strength of the material of the first intermediate layer 104 is greater than the strength of the material of the second intermediate layer 102, which can avoid wrinkles and facilitate the sheath 1 to enter the blood vessel better.

[0059] It can be seen from the above that the material strength of the second intermediate layer 102 corresponding to the expandable section 111 is the smallest, which facilitates the expansion of the sheath tube 1.

[0060] refer to Figure 6In some embodiments, the sheath tube 1 has a first state of radial contraction and a second state of radial expansion; the second intermediate layer 102 includes a first end 1021 and a second end 1022 arranged in the circumferential direction, the first end 1021 and the second end 1022 form a notch 1023, and the notch 1023 extends in the axial direction; in the first state of the sheath tube 1, the first end 1021 overlaps the outer side of the second end 1022 in the radial direction, and the direction of the notch 1023 is circumferential; in the second state of the sheath tube 1, the first end 1021 and the second end 1022 are distributed in the circumferential direction, and the direction of the notch 1023 is radial. The provision of the notch 1023 enables the radial dimension of the second intermediate layer 102 to change, and the change in the direction of the notch 1023 corresponds to the change in the state of the sheath tube 1, the first end 1021 and the second section overlap in the radial direction, so that the diameter of the sheath tube 1 is reduced, which facilitates the sheath tube 1 to enter the blood vessel; the first end 1021 and the second end 1022 are distributed in the circumferential direction, which facilitates the expansion of the sheath tube 1.

[0061] Exemplarily, the sheath tube 1 in the second state is cylindrical, the distance between the first end 1021 and the second end 1022 is the size of the notch 1023, the notch 1023 is in the radial direction, and the diameter of the sheath tube 1 is maximized. The sheath tube 1 in the second state is a deformed cylindrical shape, and the notch 1023 is changed to the circumferential direction due to the overlap of the first end 1021 and the second end 1022, and the diameter of the sheath tube 1 is minimized.

[0062] refer to Figure 2 and Figure 7 In some embodiments, the expandable vascular sheath 100 further includes a developing ring 13, which is installed at the distal end of the extension tube section 11, and is located between the second intermediate layer 102 and the inner lining 103. The developing ring 13 has an opening 131, and the direction of the opening 131 is consistent with the direction of the notch 1023; the opening 131 is arranged corresponding to the notch 1023, and the circumferential dimension of the opening 131 is greater than the circumferential dimension of the notch 1023. In this arrangement, the direction of the opening 131 of the developing ring 13 is consistent with the direction of the notch 1023, and the direction of the notch 1023 of the second intermediate layer 102 can be determined by observing the opening 131, thereby confirming the direction of the local expansion of the sheath 1 when the valve moves in the sheath 1, so as to better adjust the direction of the notch 1023 of the second intermediate layer 102, so that when the sheath 1 is bent, the direction of the notch 1023 of the second intermediate layer 102 is always inward to avoid bending, thereby further reducing damage to the blood vessel wall.

[0063] Exemplarily, the circumferential dimension of the opening 131 is larger than the circumferential dimension of the notch 1023 so that the two ends of the developing ring 13 cannot contact the first end 1021 and the second end 1022 respectively. Therefore, when in the first state, the two ends of the developing ring 13 do not overlap, and the direction of the notch 1023 of the second intermediate layer 102 can be determined by the positions of the two ends of the developing ring 13, thereby clarifying the direction of local expansion of the sheath 1. At this time, the opening 131 of the developing ring 13, that is, the notch 1023 of the second intermediate layer 102, is placed on the inner side of the blood vessel to avoid the notch 1023 from bending during expansion and causing damage to the blood vessel wall. It can be understood that when the sheath 1 is in the first state, the direction of the opening 131 is toward the overlap of the first end 1021 and the second end 1022, and when the sheath 1 is in the second state, the direction of the opening 131 is consistent with the direction of the notch 1023.

[0064] refer to Figure 6 In some embodiments, the lining 103 layer includes a first main section 1031 abutting against the inner wall of the second intermediate layer 102 and a first notch section 1032 connected to the inner wall of the first end 1021 and the inner wall of the second end 1022; the outer layer 101 includes a second main section 1011 abutting against the outer wall of the second intermediate layer 102 and a second notch section 1012 connected to the outer wall of the second end 1022 and the outer wall of the second intermediate layer 102; in the sheath 1 in the first state, the first notch section 1032 is located between the first end 1021 and the second end 1022; in the sheath 1 in the second state, the first notch section 1032, the first end 1021 and the second end 1022 form a circular ring shape. With such a configuration, the first notch section 1032 can connect the two ends of the inner side of the notch 1023 together, ensuring that the outer periphery of the sheath tube 1 is closed; the second notch section 1012 can connect the two ends of the outer side of the notch 1023 together, ensuring that the inner periphery of the sheath tube 1 is closed, avoiding wrinkles caused by the notch 1023 when entering the blood vessel, effectively enhancing the bending and compression resistance of the sheath tube 1, and does not affect the expansion performance of the sheath tube 1, facilitating the change of the state of the sheath tube 1.

[0065] Exemplarily, when the sheath tube 1 is in the second state, the first notch section 1032 and the second notch section 1012 are respectively located at the inner and outer sides of the notch 1023. The first notch section 1032 and the second notch section 1012 can both undergo elastic deformation to facilitate the expansion of the sheath tube 1.

[0066] refer to Fig. 9In some embodiments, the expansion section includes an insertion section 1111 and a transition section 1112 connected in the axial direction, and the distal end of the transition section 1112 is connected to the proximal end of the insertion section 1111. The strength of the material of the outer layer 101 corresponding to the reducing section 112 and the transition section 1112 is greater than the strength of the material of the outer layer 101 corresponding to the insertion section 1111. The thickness of the outer layer 101 corresponding to the reducing section 112 and the transition section 1112 is greater than the thickness of the outer layer 101 corresponding to the insertion section 1111. The transition section 1112 also includes a reinforcement layer, and the inner wall of the reinforcement layer abuts against the outer wall of the outer layer 101. In this way, the strength or thickness of the transition section 1112 and the reducing section 112 is increased, and the risk of bulging of the sheath tube 1 caused by the pressure difference between the inside and the outside of the body after the insertion section 1111 is inserted into the blood vessel is avoided.

[0067] Exemplarily, the reinforcement layer of the transition section 1112 may have multiple layers.

[0068] In some embodiments, the material of the outer layer 101 is a tough material, and the outer wall of the outer layer 101 has a hydrophilic coating. In this way, the hydrophilic coating can reduce friction.

[0069] In some embodiments, the friction coefficient of the outer wall of the outer layer 101 is less than 0.1. Reducing the friction coefficient will prevent the sheath tube 1 from being tight when entering and exiting the blood vessel, thereby reducing the difficulty of surgery and the damage to the blood vessel wall.

[0070] For example, the material of the outer layer 101 may be a material with good toughness, such as polyether block polyamide (Pebax), thermoplastic polyurethane elastomer (TPU), etc.

[0071] refer to Fig.10 In some embodiments, the extension tube section 11 further includes a locking section 113, the distal end of the locking section 113 is connected to the proximal end of the diameter-reducing section 112, and the outer diameter of the proximal end of the locking section 113 gradually increases along the direction away from the diameter-reducing section 112;

[0072] The expandable vascular sheath 100 also includes a hemostatic valve 2, a locking head 3 and a three-way valve 4. The three-way valve 4 is connected to the hemostatic valve 2. The hemostatic valve 2 includes a connecting end 21 and a fixed end 22. The outer wall of the connecting end 21 abuts against the inner wall of the locking section 113. The proximal end of the locking head 3 is fixed to the fixed end 22. The inner wall of the distal end of the locking head 3 is convexly provided with multi-layer bosses 31 along the circumferential direction. The multi-layer bosses 31 are arranged along the axial direction. The multi-layer bosses 31 abut against the outer walls of the locking section 113 and the part of the diameter-reducing section 112. In this way, the proximal end of the locking head 3 plays a role in tightening the fixed end 22. The multi-layer boss 31 structure of the locking head 3 increases the contact surface with the locking section 113 and the part of the diameter-reducing section 112. The force exerted on each contact surface is different, which can make the locking section 113 tightly abut against the connecting end 21, further strengthen the tightness of the connection, and the process is reliable and stable, so that the sheath tube 1 is not easy to separate from the hemostatic valve 2.

[0073] Exemplarily, along the axial direction from the proximal end to the distal end, there are the hemostatic valve 2, the locking head 3, the locking section 113, the reducing section 112, the transition section 1112, the insertion section 1111 and the tip tube section 12 in sequence.

[0074] Exemplarily, the fixing end 22 is threadedly connected to the locking head 3. The size of the multi-layer boss 31 increases from the proximal end to the distal end. The outer surface of the proximal end of the locking section 113 is a conical surface.

[0075] The technical features of the embodiments disclosed above can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the embodiments described above 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.

[0076] In the embodiments disclosed above, unless otherwise clearly specified and limited, the execution order of each step is not limited, for example, it can be executed in parallel, or it can be executed successively in different orders. The sub-steps of each step can also be executed alternately. The above-mentioned various forms of processes can be used, and steps can be reordered, added or deleted, as long as the desired results of the technical solution provided in the embodiment of the present disclosure can be achieved, and this document does not limit it here.

[0077] The embodiments disclosed above only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An expandable vascular sheath, characterized in that: The invention comprises a radially expandable sheath tube, wherein the sheath tube forms an instrument channel extending in the axial direction, and the sheath tube comprises an extension tube section and a tip tube section connected in the axial direction; the distal end of the extension tube section is connected to the proximal end of the tip tube section; The tip tube segment includes a first middle layer, an inner wall of which is provided with a pre-cut groove, the pre-cut groove extends from the proximal end of the tip tube segment toward the distal end close to the tip tube segment, and the distance between the pre-cut groove and the distal end of the tip tube segment is greater than zero, and the depth of the pre-cut groove is less than the thickness of the first middle layer.

2. The expandable vascular sheath according to claim 1, characterized in that: The pre-cut groove extends from the proximal end of the tip tube segment to the middle of the tip tube segment.

3. The expandable vascular sheath according to claim 1, characterized in that: The extended pipe section comprises an outer layer, a second intermediate layer and an inner liner stacked in sequence along the radial direction; the distal end to the proximal end of the extended pipe section comprise an expandable section and a diameter-changing section connected in sequence, and the outer diameter of the diameter-changing section is larger than the outer diameter of the expandable section; The strength of the material of the second middle layer corresponding to the expandable section is less than the strength of the material of the second middle layer corresponding to the diameter-changing section, and the strength of the material of the second middle layer corresponding to the diameter-changing section gradually decreases along the axial direction toward the expansion section.

4. The expandable vascular sheath according to claim 3, characterized in that: The proximal end of the first intermediate layer is connected to the distal end of the second intermediate layer, and the strength of the material of the first intermediate layer is greater than the strength of the material of the second intermediate layer corresponding to the expandable segment.

5. The expandable vascular sheath according to claim 3, characterized in that: The sheath tube has a first state contracted along the radial direction and a second state expanded along the radial direction; The second intermediate layer includes a first end and a second end arranged along the circumferential direction, the first end and the second end form a notch, and the notch extends along the axial direction; when the sheath is in the first state, the first end overlaps with the outer side of the second end along the radial direction, and the direction of the notch is the circumferential direction; when the sheath is in the second state, the first end and the second end are distributed along the circumferential direction, and the direction of the notch is the radial direction.

6. The expandable vascular sheath according to claim 5, characterized in that: It also includes a developing ring, which is installed at the distal end of the extended pipe section, the developing ring is located between the second intermediate layer and the lining, and the developing ring has an opening, the direction of the opening is consistent with the direction of the notch; the opening is set corresponding to the notch and the circumferential size of the opening is larger than the circumferential size of the notch.

7. The expandable vascular sheath according to claim 6, characterized in that: The inner lining includes a first main body section abutting against the inner wall of the second intermediate layer and a first notch section connected to the inner wall of the first end and the inner wall of the second end; the outer layer includes a second main body section abutting against the outer wall of the second intermediate layer and a second notch section connected to the outer wall of the second end and the outer wall of the second intermediate layer; In the sheath tube in the first state, the first notch section is located between the first end and the second end; in the sheath tube in the second state, the first notch section, the first end and the second end form a circular ring shape.

8. The expandable vascular sheath according to claim 3, characterized in that: The expansion section includes an insertion section and a transition section connected along the axial direction, and the distal end of the transition section is connected to the proximal end of the insertion section; The strength of the material of the outer layer corresponding to the diameter-changing section and the transition section is greater than the strength of the material of the outer layer corresponding to the insertion section; or The thickness of the outer layer corresponding to the diameter-changing section and the transition section is greater than the thickness of the outer layer corresponding to the insertion section; or The transition section further includes a reinforcement layer, the inner wall of the reinforcement layer abuts against the outer wall of the outer layer.

9. The expandable vascular sheath according to claim 3, characterized in that: The material of the outer layer is a tough material; the outer wall of the outer layer has a hydrophilic coating; or The friction coefficient of the outer wall of the outer layer is less than 0.

1.

10. The expandable vascular sheath according to claim 3, characterized in that: The extension pipe section further comprises a locking section, the distal end of the locking section is connected to the proximal end of the diameter-changing section, and the outer diameter of the proximal end of the locking section gradually increases along the direction away from the diameter-changing section; The expandable vascular sheath also includes a hemostatic valve, a locking head and a three-way valve, the three-way valve is connected to the hemostatic valve, the hemostatic valve includes a connecting end and a fixed end, the outer wall of the connecting end abuts against the inner wall of the locking section; the proximal end of the locking head is fixed to the fixed end, the inner wall of the distal end of the locking head is provided with a plurality of layers of bosses along the circumferential direction, the plurality of layers of bosses are arranged along the axial direction, and the plurality of layers of bosses abut against the outer wall of the locking section and part of the reducing section.

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