Expandable vascular sheath

Abstract

The present disclosure relates to an expandable vascular sheath. The expandable vascular sheath comprises a radially expandable sheath tube forming an instrument channel extending in an axial direction, the sheath tube comprising an extension tube segment and a tip tube segment connected in an axial direction, a distal end of the extension tube segment being connected to a proximal end of the tip tube segment, the tip tube segment comprising a first intermediate layer, an inner wall of the first intermediate layer being provided with a pre-cut slot extending from the proximal end of the tip tube segment towards the distal end of the tip tube segment and the distance from the distal end of the tip tube segment being greater than zero, the depth of the pre-cut slot being less than the thickness of the first intermediate layer. The outer wall of the tip tube segment of the sheath tube maintains axial and axial integrity, so that the distal end of the tip tube segment has sufficient strength when entering the blood vessel, avoiding the distal end of the tip tube segment from wrinkling and cracking prematurely when entering the human body. Due to the design of the pre-cut slot, the valve can be conveniently and uniformly split when extending out of the sheath tube, which is conducive to the valve being smoothly extended and retracted from the tip tube segment.

Description

TECHNICAL FIELD

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

[0002] With the continuous development of science, the increasing improvement of medical devices and operating techniques, and the deeper research of related medical mechanisms, transcatheter implantation is more and more applied in clinical practice. In recent years, researchers have been committed to performing artificial heart valve replacement without opening the chest or placing the patient on extracorporeal circulation, so as to minimize trauma. The existing transcatheter valve replacement technology has significantly reduced the trauma of the operation on the patient. When performing transcatheter valve replacement surgery, a vascular sheath is first used to establish a vascular access in the femoral artery or other arteries and veins of the human body, 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] The existing expandable vascular sheath enters the blood vessel at the tip first when establishing an access in the blood vessel, and the valve device passes through the access and finally extends from the tip. However, the existing expandable vascular sheath has an opening or a gap at the tip for the convenience of the valve device extending from and retracting into the tip, which causes the tip of the expandable vascular sheath to wrinkle or hinder when entering the blood vessel. SUMMARY

[0004] Therefore, in view of the above problems, it is necessary to provide an expandable vascular sheath.

[0005] The expandable vascular sheath provided by the embodiment of the present disclosure includes a radially expandable sheath tube, the sheath tube forms a device channel extending in the axial direction, and the sheath tube includes an extension tube segment and a tip tube segment connected in 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, and a pre-cut groove is formed in the inner wall of the first intermediate layer. The pre-cut groove extends from the proximal end of the tip tube segment towards the distal end of 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. The depth of the pre-cut groove is less than the thickness of the first intermediate layer.

[0006] The expandable vascular sheath provided by the embodiment of the present disclosure enters the blood vessel at the tip tube segment first, and then the partial extension tube segment also enters the blood vessel to establish an access, so that the device can pass through the device channel and enter the human body from the tip tube segment. The pre-cut groove is formed in the inner wall of the first intermediate layer of the tip tube segment, and extends from the proximal end of the tip tube segment to the distal end of the tip tube segment, so that the first intermediate layer of the tip tube segment is continuous in the circumferential direction, avoiding the distal end of the tip tube segment from wrinkling and cracking prematurely when entering the human body. Due to the design of the pre-cut groove, the tip tube segment is uniformly cracked when the valve device extends out of the sheath tube, which is conducive to the valve device extending out of and retracting into the tip tube segment smoothly.

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

[0008] In this way, the middle to the distal end of the tip tube segment is continuous in the circumferential direction, which can better avoid the tip tube segment from being wrinkled or cracked prematurely when it enters the human body, and reduce the uneven cracking caused by the pre-cut groove being too short or the premature cracking caused by the pre-cut groove being too long when the valve extends from the tip tube segment.

[0009] In some embodiments, the extension tube segment includes 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 extension tube segment includes an expandable segment and a variable diameter segment connected in sequence, the outer diameter size of the variable diameter segment is larger than that of the expandable segment; the material strength of the second intermediate layer corresponding to the expandable segment is smaller than that of the second intermediate layer corresponding to the variable diameter segment, and the material strength of the second intermediate layer corresponding to the variable diameter segment gradually decreases towards the expandable segment along the axial direction.

[0010] In this way, the smaller outer diameter size of the expandable segment than that of the variable diameter segment makes the variable diameter segment have a smaller diameter, which facilitates the variable diameter segment to enter the blood vessel more smoothly and reduces the damage to the blood vessel wall. The different material strengths of the second intermediate layer at different positions and the gradually changing strength of the variable diameter segment make the sheath tube in the blood vessel remain soft and not easily damage the blood vessel, while ensuring that the outer layer is too smooth without steps, so that the sheath tube has better support and passability, facilitating the valve and the instrument to pass through.

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

[0012] In this way, the material strength of the first intermediate layer being greater than that of the second intermediate layer can avoid wrinkles to facilitate the sheath tube to enter the blood vessel better.

[0013] In some embodiments, the sheath tube has a first state of contraction in the radial direction and a second state of expansion in the radial direction; the second intermediate layer includes a first end and a second end arranged in the circumferential direction, the first end and the second end form a gap, and the gap extends in the axial direction; in the first state, the first end overlaps the outside of the second end in the radial direction, and the direction of the gap is circumferential; in the second state, the first end and the second end are distributed in the circumferential direction, and the direction of the gap is radial.

[0014] The gap can change the radial size of the second intermediate layer, and the change in the direction of the gap corresponds to the change in the state of the sheath tube. When the first end and the second end overlap in the radial direction, the diameter of the sheath tube decreases to facilitate the sheath tube to enter the blood vessel; when the first end and the second end are distributed in the circumferential direction, the sheath tube expands.

[0015] In some embodiments, the expandable vascular sheath further comprises a visualization ring mounted on the distal end of the extension tube segment, the visualization ring being located between the second intermediate layer and the inner liner, the visualization ring having an opening, the opening being oriented in the same direction as the cutout; the opening being arranged corresponding to the cutout and the circumferential dimension of the opening being larger than the circumferential dimension of the cutout.

[0016] In this way, the opening of the visualization ring is oriented in the same direction as the cutout, and the direction of the cutout of the second intermediate layer can be determined by observing the opening, so as to confirm the direction of the local expansion of the sheath tube when the valve moves in the sheath tube, so as to better adjust the direction of the cutout of the second intermediate layer, so that the direction of the cutout of the second intermediate layer is always inward when the sheath tube is bent, further reducing the damage to the blood vessel wall.

[0017] In some embodiments, the inner liner comprises a first main segment abutting the inner wall of the second intermediate layer and a first cutout segment connected to the inner wall of the first end and the inner wall of the second end; the outer layer comprises a second main segment abutting the outer wall of the second intermediate layer and a second cutout segment connected to the outer wall of the second end and the outer wall of the second intermediate layer; in the first state of the sheath tube, the first cutout segment is located between the first end and the second end; in the second state of the sheath tube, the first cutout segment, the first end and the second end form a circular ring.

[0018] In this way, the first cutout segment can connect the two ends of the inner side of the cutout together, ensuring the closure of the outer periphery of the sheath tube; the second cutout segment can connect the two ends of the outer side of the cutout together, ensuring the closure of the inner periphery of the sheath tube, avoiding wrinkles caused by the cutout when entering the blood vessel, effectively enhancing the anti-bending and anti-compression ability of the sheath tube, and not affecting the expansion performance of the sheath tube, facilitating the change of the state of the sheath tube.

[0019] In some embodiments, the expansion segment comprises an insertion segment and a transition segment connected in the axial direction, the distal end of the transition segment being connected to the proximal end of the insertion segment; the material strength of the outer layer corresponding to the transition segment and the variable diameter segment is greater than the material strength of the outer layer corresponding to the insertion segment; or the thickness of the outer layer corresponding to the transition segment and the variable diameter segment is greater than the thickness of the outer layer corresponding to the insertion segment; or the transition segment further comprises a reinforcing layer, the inner wall of the reinforcing layer abutting the outer wall of the outer layer.

[0020] In this way, the strength or thickness of the transition segment and the variable diameter segment is increased, avoiding the risk of sheath tube bulging caused by the pressure difference between the inside and outside of the body after the insertion segment is inserted into the blood vessel.

[0021] In some embodiments, the material of the outer layer is a ductile 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] In this way, the hydrophilic coating or the reduced friction coefficient makes the sheath tube not tight and rough when entering and exiting the blood vessel, reducing the difficulty of the operation and reducing the damage to the blood vessel wall.

[0023] In some embodiments, the extension section further includes a locking section, the distal end of which is connected to the proximal end of the reducing section, the outer diameter of the proximal end of which gradually increases along the opposite side of the 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 provided with multiple protrusions along the circumference. The multiple protrusions are arranged along the axial direction and abut against the outer wall of the locking section and part of the diameter-changing section.

[0025] With this configuration, the proximal end of the locking head secures the fixed end. The multi-layered boss structure of the locking head increases the contact surface with the locking section and part of the variable diameter section, and each contact surface is subjected to different forces, which allows the locking section to tightly abut against the connection end, further strengthening the tightness of the connection. The process is reliable and stable, making it difficult for the sheath to detach from the hemostatic valve. Attached Figure Description

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

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

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

[0029] Figure 4 This is a schematic diagram of the overall structure of the sheath in an embodiment of this disclosure;

[0030] Figure 5 This is a cross-sectional view of the sheath in an embodiment of this disclosure;

[0031] Figure 6 This is a schematic diagram of the cross-section along the EE direction as shown in Figure 4;

[0032] Figure 7 This is a partial structural schematic diagram of the extension tube segment and developing ring in an embodiment of this disclosure;

[0033] Figure 8 for Figure 1 Sectional view at point B;

[0034] Figure 9 for Figure 1 Sectional view at point C;

[0035] Figure 10 for Figure 1 Sectional view at point D.

[0036] Reference Signs:

[0037] 100, expandable vascular sheath; 1, sheath tube; 11, extension tube segment; 111, expandable segment; 1111, insertion segment; 1112, transition segment; 112, variable diameter segment; 113, locking segment; 101, outer layer; 1011, second body segment; 1012, second notched segment; 102, second intermediate layer; 1021, first end; 1022, second end; 1023, notch; 103, inner liner; 1031, first body segment; 1032, first notched segment; 12, tip tube segment; 121, pre-cut slot; 104, first intermediate layer; 13, radiopaque ring; 131, opening; 2, hemostatic valve; 21, connection end; 22, fixed end; 3, locking head; 31, boss; 4, three-way valve. DETAILED DESCRIPTION

[0038] In order to make the above objectives, features and advantages of the embodiments of the present disclosure more clear and easy to understand, the specific embodiments of the embodiments of the present disclosure will be described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, the embodiments of the present disclosure can be implemented in many other different ways than described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the embodiments of the present disclosure, so the embodiments of the present disclosure are not limited to the specific examples 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", "upper", "lower", "front", "rear", "left", "right", "vertical", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the embodiments of the present disclosure and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present disclosure.

[0040] In the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an implied order of magnitude of the features being described. Thus, a feature defined with "first", "second" can explicitly or implicitly include at least one of the features. For example, the first intermediate layer can also be referred to as the second intermediate layer, and the second intermediate layer can also be referred to as the first intermediate layer. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0042] In the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the terms "connected", "connected", and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be flexibly connected, or it can be rigidly connected in at least one direction; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be directly connected while the intermediate medium exists, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. The terms "installation", "arrangement", "fixation" and the like can be understood in a broad sense as connection. For those skilled 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] Reference 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 technical field of medical devices. It should be noted that the distal end and the proximal end referred to in the present disclosure are based on the operator, and 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] In combination Figure 2 and Figure 3 , the embodiments of the present disclosure provide an expandable vascular sheath 100, which comprises a radially expandable sheath tube 1, and the sheath tube 1 forms a device channel extending in the axial direction. For example, the sheath tube 1 partially extends into the human body blood vessel to establish a vascular access, at this time, the sheath tube 1 is in a contracted state, and the subsequent valve and other devices can pass through the device channel to enter the human body, at this time, the sheath tube 1 is in an expanded state. The establishment of the vascular access through the sheath tube 1 can reduce the trauma of the human body.

[0045] The sheath tube 1 comprises an extension tube segment 11 and a tip tube segment 12 connected in an 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 enters the human body first 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. The tip tube segment 12 comprises a first intermediate layer 104, and the inner wall of the first intermediate layer 104 is provided with a pre-cut slot 121 extending from the proximal end of the tip tube segment 12 towards the distal end of the tip tube segment 12, and the distance from the distal end of the tip tube segment 12 is greater than zero, and the depth of the pre-cut slot 121 is less than the thickness of the first intermediate layer 104.

[0046] The expandable vascular sheath 100 provided by the embodiment of the present disclosure is capable of establishing a passageway by first entering the blood vessel with the tip tube segment 12 of the sheath tube 1 and then entering the blood vessel with the extension tube segment 11, so that the instrument can pass through the instrument channel and enter the human body from the tip tube segment 12. The pre-cut slot 121 is provided on the inner wall of the first intermediate layer 104 of the tip tube segment 12, and extends 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 in 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, and the distal end of the tip tube segment 12 has sufficient strength when entering the blood vessel, thereby avoiding wrinkles caused by the incomplete outer wall of the tip tube segment 12.

[0047] Further, when the instrument finally extends out of the distal end of the tip tube segment 12 after moving in the instrument channel, tearing of the tip tube segment 12 will occur when extending out. The pre-cut slot 121 of the second intermediate layer 102 has a partial thickness less than the thickness of other portions, so that the pre-cut slot 121 is torn first when the tip tube segment 12 is subjected to internal stress, facilitating uniform tearing of the tip tube segment 12 and smooth extension and retraction of the instrument. In addition, the design of the pre-cut slot 121 avoids greater tearing of the tip tube segment 12 when entering the blood vessel due to the incomplete outer wall of the tip tube segment 12, 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, and preventing the instrument from being unable to smoothly extend and retract from the tip tube segment 12.

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

[0049] Exemplarily, the depth of the pre-cut slot 121 is half of the thickness of the first intermediate layer 104. In other embodiments, the depth of the pre-cut slot 121 is less than half of the thickness of the first intermediate layer 104; or the depth of the pre-cut slot 121 is greater than half of 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 can be equal to the circumferential dimension of the pre-cut groove 121.

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

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

[0053] With reference to Figure 1 , Figure 4 , Figure 5 and Figure 8 In some embodiments, the extension tube segment 11 includes, in sequence along the radial direction, an outer layer 101, a second intermediate layer 102, and an inner liner 103. The distal end to the proximal end of the extension tube segment 11 includes, in sequence, an expandable segment 111 and a variable diameter segment 112, and the outer diameter dimension of the variable diameter segment 112 is greater than the outer diameter dimension of the expandable segment 111. The outer diameter dimension of the expandable segment 111 is less than the outer diameter dimension of the variable diameter segment 112, so that the variable diameter segment 112 has a smaller diameter, facilitating the variable diameter segment 112 to enter the blood vessel more smoothly while reducing damage to the blood vessel wall.

[0054] The material of the second intermediate layer 102 corresponding to the expandable section 111 has a smaller strength than the material of the second intermediate layer 102 corresponding to the variable-diameter section 112, and the strength of the material of the second intermediate layer 102 corresponding to the variable-diameter section 112 gradually decreases along the axial direction towards the expandable section. The different strengths of the material of the second intermediate layer 102 at different positions and the gradually changing strength of the variable-diameter section 112 are configured to ensure that the sheath 1 in the blood vessel is not excessively smooth and has no steps, so that the sheath 1 has better supportability and passability, facilitating the passage of the valve and the instrument. Since the thickness of the second intermediate layer 102 is greater than the thicknesses of the outer layer 101 and the inner liner 103, the supportability of the second intermediate layer 102 is better than those of the outer layer 101 and the inner liner 103, and the deformation of the second intermediate layer 102 can drive the deformation of the outer layer 101 and the inner liner 103. Therefore, compared with changing the material strength of the outer layer 101 or the inner liner 103, changing the material strength of the second intermediate layer 102 can greatly improve the performance and operability of the sheath 1, ensure the integrity and smoothness of the outer layer 101, and make the sheath 1 move more conveniently in the blood vessel and further reduce the damage to the blood vessel.

[0055] Exemplarily, the material of the second intermediate layer 102 can be a soft plastic material, for example, polyether block polyamide (Pebax), thermoplastic polyurethane elastomer (tpu), etc.

[0056] Exemplarily, the inner liner 103 can be made of a relatively lubricious material, for example, polyethylene (PE), polytetrafluoroethylene (PTFE), etc., so that the medical instrument can pass through the channel smoothly.

[0057] Reference Figure 5 , Figure 6 , Figure 8 , Figure 9 and Figure 10 Exemplarily, the materials of the second intermediate layer 102 with different strengths are represented by different hatch lines in the figure.

[0058] Reference 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 material of the first intermediate layer 104 has a greater strength than the material of the second intermediate layer 102 corresponding to the expandable section 111. In this way, the greater strength of the material of the first intermediate layer 104 than the material of the second intermediate layer 102 can avoid the generation of wrinkles, so that the sheath 1 can better enter the blood vessel.

[0059] As can be seen from the above, the material of the second intermediate layer 102 corresponding to the expandable section 111 has the smallest strength, facilitating the expansion of the sheath 1.

[0060] Reference Figure 6In some embodiments, the sheath 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 circumferentially, the first end 1021 and the second end 1022 form a gap 1023 extending in the axial direction; in the first state of the sheath 1, the first end 1021 is radially overlapped outside the second end 1022, and the gap 1023 is circumferentially oriented; in the second state of the sheath 1, the first end 1021 and the second end 1022 are circumferentially distributed, and the gap 1023 is radially oriented. The gap 1023 is arranged to change the radial dimension of the second intermediate layer 102, and the change in the orientation of the gap 1023 corresponds to the change in the state of the sheath 1, the radial overlap of the first end 1021 and the second end 1022 allows the sheath 1 to enter the blood vessel with a reduced diameter; the circumferential distribution of the first end 1021 and the second end 1022 facilitates the expansion of the sheath 1.

[0061] Exemplarily, the sheath 1 in the second state is in a cylindrical shape, the distance between the first end 1021 and the second end 1022 is the size of the gap 1023, the gap 1023 is radially oriented, and the diameter of the sheath 1 reaches the maximum size. The sheath 1 in the second state is in a deformed cylindrical shape, and the overlap of the first end 1021 and the second end 1022 changes the orientation of the gap 1023 to be circumferential, and the diameter of the sheath 1 reaches the minimum size.

[0062] Reference Figure 2 and Figure 7 In some embodiments, the expandable vascular sheath 100 further includes a visualization ring 13 mounted on the distal end of the extension tube segment 11, the visualization ring 13 is located between the second intermediate layer 102 and the inner liner 103, the visualization ring 13 has an opening 131, the opening 131 is oriented in the same direction as the gap 1023; the opening 131 is arranged corresponding to the gap 1023, and the circumferential size of the opening 131 is greater than the circumferential size of the gap 1023. In this way, the opening 131 of the visualization ring 13 is oriented in the same direction as the gap 1023, and the direction of the gap 1023 of the second intermediate layer 102 can be determined by observing the opening 131, so as to confirm 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 gap 1023 of the second intermediate layer 102, so that the direction of the gap 1023 of the second intermediate layer 102 is always inward when the sheath 1 is bent, and further reduces the damage to the blood vessel wall.

[0063] Exemplarily, the circumferential size of the opening 131 is greater than the circumferential size of the gap 1023, so that the two ends of the developing ring 13 fail to contact the first end 1021 and the second end 1022 respectively, and thus, in the first state, the two ends of the developing ring 13 do not overlap, and the direction of the gap 1023 of the second intermediate layer 102 can be determined by the positions of the two ends of the developing ring 13, so as to determine the direction of the local expansion of the sheath tube 1. At this time, the opening 131 of the developing ring 13, i.e., the gap 1023 of the second intermediate layer 102, is placed on the inner side of the blood vessel to avoid damage to the blood vessel wall caused by the bending of the gap 1023 during expansion. It can be understood that the opening 131 of the sheath tube 1 in the first state is directed to the overlapping position of the first end 1021 and the second end 1022, and the opening 131 of the sheath tube 1 in the second state is directed in the same direction as the direction of the gap 1023.

[0064] Reference Figure 6 In some embodiments, the inner layer 103 includes a first main segment 1031 abutting the inner wall of the second intermediate layer 102 and a first gap segment 1032 connecting 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 segment 1011 abutting the outer wall of the second intermediate layer 102 and a second gap segment 1012 connecting the outer wall of the second end 1022 and the outer wall of the second intermediate layer 102; in the first state of the sheath tube 1, the first gap segment 1032 is located between the first end 1021 and the second end 1022; in the second state of the sheath tube 1, the first gap segment 1032, the first end 1021 and the second end 1022 form a circular ring. In this way, the first gap segment 1032 can connect the two ends of the inner side of the gap 1023 together, ensuring the closure of the outer periphery of the sheath tube 1; the second gap segment 1012 can connect the two ends of the outer side of the gap 1023 together, ensuring the closure of the inner periphery of the sheath tube 1, avoiding wrinkles caused by the gap 1023 when entering the blood vessel, effectively enhancing the bending and compression resistance of the sheath tube 1, and not affecting the expansion performance of the sheath tube 1, facilitating the change of the state of the sheath tube 1.

[0065] Exemplarily, in the second state of the sheath tube 1, the first gap segment 1032 and the second gap segment 1012 are located on the inner and outer sides of the gap 1023 respectively. The first gap segment 1032 and the second gap segment 1012 can both elastically deform, facilitating the expansion of the sheath tube 1.

[0066] Reference Figure 9In some embodiments, the expandable section includes an insertion section 1111 and a transition section 1112 connected along an axial direction, a distal end of the transition section 1112 being connected to a proximal end of the insertion section 1111. The material of the outer layer 101 corresponding to the transition section 1112 and the variable-diameter section 112 has a higher strength than the material of the outer layer 101 corresponding to the insertion section 1111. The thickness of the outer layer 101 corresponding to the transition section 1112 and the variable-diameter section 112 is greater than the thickness of the outer layer 101 corresponding to the insertion section 1111. The transition section 1112 further includes a reinforcing layer, an inner wall of the reinforcing layer abutting against an outer wall of the outer layer 101. In this way, the strength or thickness of the transition section 1112 and the variable-diameter section 112 is increased, and the risk of the sheath tube 1 bulging due to the pressure difference between the inside and outside of the body after the insertion section 1111 is inserted into the blood vessel is avoided.

[0067] Exemplarily, the reinforcing layer of the transition section 1112 can have multiple layers.

[0068] In some embodiments, the material of the outer layer 101 is a ductile 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 coefficient of friction of the outer wall of the outer layer 101 is less than 0.1. Reducing the coefficient of friction makes the sheath tube 1 not tight when entering and exiting the blood vessel, reduces the difficulty of the operation, and reduces the damage to the blood vessel wall.

[0070] Exemplarily, the material of the outer layer 101 can be selected from materials with good ductility, such as polyether block polyamide (Pebax), thermoplastic polyurethane elastomer (tpu), etc.

[0071] Reference Figure 10 In some embodiments, the extension tube section 11 further includes a locking section 113, a distal end of the locking section 113 being connected to a proximal end of the variable-diameter section 112, and an outer diameter of a proximal end of the locking section 113 gradually increasing in a direction away from the variable-diameter section 112.

[0072] The expandable vascular sheath 100 further 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. An outer wall of the connecting end 21 abuts against an inner wall of the locking section 113. A proximal end of the locking head 3 is fixed to the fixed end 22. An inner wall of a distal end of the locking head 3 is circumferentially provided with multiple layers of bosses 31. The multiple layers of bosses 31 are arranged along an axial direction. The multiple layers of bosses 31 abut against the outer wall of the locking section 113 and part of the variable-diameter section 112. In this way, the proximal end of the locking head 3 plays a fastening role on the fixed end 22. The structure of the multiple layers of bosses 31 of the locking head 3 increases the contact area with the locking section 113 and part of the variable-diameter section 112. The force on each contact area is different, which can make the locking section 113 tightly abut against the connecting end 21, further strengthening the fastening of the connection, making the process reliable and stable, and making the sheath tube 1 not easy to be separated from the hemostatic valve 2.

[0073] Exemplarily, 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 are sequentially arranged from the proximal end to the distal end along the axial direction.

[0074] Exemplarily, the fixed end 22 is threadedly connected with the locking head 3. The sizes of the multi-layer bosses 31 increase 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 above disclosed embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as within the scope of the present disclosure.

[0076] In the above disclosed embodiments, unless otherwise explicitly specified and limited, the execution order of each step is not limited, for example, the steps can be executed in parallel, or in different orders. The sub-steps of each step can also be executed in an interleaved manner. The above various forms of flow can be used, and the steps can be reordered, added or deleted, as long as the desired results of the technical solutions provided by the embodiments of the present disclosure can be achieved, which are not limited herein.

[0077] The above disclosed embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. An expandable vascular sheath, characterized by, The sheath tube comprises a radially expandable sheath tube, which forms an instrument channel extending in the axial direction, and 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, and the distal end to the proximal end of the extension tube section comprises an expandable section and a variable diameter section connected in sequence; The tip tube section comprises a first intermediate layer, and a pre-cut groove is formed in the inner wall of the first intermediate layer, the pre-cut groove extends from the proximal end of the tip tube section towards the distal end of the tip tube section, and the distance from the pre-cut groove to the distal end of the tip tube section is greater than zero, and the depth of the pre-cut groove is less than the thickness of the first intermediate layer; The extension tube section comprises an outer layer, a second intermediate layer and an inner lining stacked in sequence in the radial direction; the material strength of the second intermediate layer corresponding to the expandable section is less than the material strength of the second intermediate layer corresponding to the variable diameter section, and the material strength of the second intermediate layer corresponding to the variable diameter section gradually decreases towards the expandable section in the axial direction; The proximal end of the first intermediate layer is connected to the distal end of the second intermediate layer, the material strength of the first intermediate layer is greater than the material strength of the second intermediate layer corresponding to the expandable section, and the pre-cut groove is used to crack the tip tube section when the instrument is extended.

2. The expandable vascular sheath of claim 1, wherein, The pre-cut groove extends from the proximal end of the tip tube section to the middle of the tip tube section.

3. The expandable vascular sheath of claim 1, wherein, The outer diameter of the variable diameter section is greater than the outer diameter of the expandable section.

4. The expandable vascular sheath of claim 3, wherein, The sheath tube has a first state of contraction in the radial direction and a second state of expansion in the radial direction; The second intermediate layer comprises a first end and a second end arranged in the circumferential direction, and the first end and the second end form a gap extending in the axial direction; in the first state of the sheath tube, the first end overlaps the second end outside in the radial direction, and the direction of the gap is the circumferential direction; in the second state of the sheath tube, the first end and the second end are distributed in the circumferential direction, and the direction of the gap is the radial direction.

5. The expandable vascular sheath of claim 4, wherein, Further comprising a developing ring mounted on the distal end of the extension tube section, the developing ring is located between the second intermediate layer and the inner lining, the developing ring has an opening, the direction of the opening is consistent with the direction of the gap; the opening is arranged corresponding to the gap, and the circumferential dimension of the opening is greater than the circumferential dimension of the gap.

6. The expandable vascular sheath of claim 5, wherein, The inner lining comprises a first main section abutting the inner wall of the second intermediate layer and a first gap section connected to the inner wall of the first end and the inner wall of the second end; the outer layer comprises a second main section abutting the outer wall of the second intermediate layer and a second gap section connected to the outer wall of the second end and the outer wall of the second intermediate layer; In the first state of the sheath tube, the first gap section is located between the first end and the second end; in the second state of the sheath tube, the first gap section, the first end and the second end form a circular ring.

7. The expandable vascular sheath of claim 3, wherein, The expandable section comprises an insertion section and a transition section connected in the axial direction, and the distal end of the transition section is connected to the proximal end of the insertion section; The material strength of the outer layer corresponding to the variable diameter section and the transition section is greater than the material strength of the outer layer corresponding to the insertion section; or The thickness of the outer layer corresponding to the transition section and the variable diameter section is greater than the thickness of the outer layer corresponding to the insertion section; or The transition section further comprises a reinforcing layer, and an inner wall of the reinforcing layer abuts against an outer wall of the outer layer.

8. The expandable vascular sheath of claim 3, wherein, The material of the outer layer is a ductile 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.

9. The expandable vascular sheath of claim 3, wherein, The extension tube section further comprises a locking section, a distal end of the locking section is connected to a proximal end of the variable diameter section, and an outer diameter dimension of a proximal end of the locking section gradually increases in a direction away from the variable diameter section; The expandable vascular sheath further comprises a hemostatic valve, a locking head, and a three-way valve, the three-way valve is communicated with the hemostatic valve, the hemostatic valve comprises a connecting end and a fixed end, an outer wall of the connecting end abuts against an inner wall of the locking section; a proximal end of the locking head is fixed to the fixed end, and an inner wall of a distal end of the locking head is circumferentially provided with a plurality of layers of bosses, the plurality of layers of bosses are arranged along the axial direction, and the plurality of layers of bosses abut against the outer walls of the locking section and part of the variable diameter section.

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