Expandable sheath, introducer using the expandable sheath, and method of using the same

Abstract

The present invention discloses an expandable sheath, which is in a longitudinal shape with a tubular cavity, wherein the longitudinal direction is the axial direction and the direction perpendicular to the axial direction is the radial direction; the expandable sheath comprises an elastic layer which can be elastically deformed radially and forms an inner cavity and a reinforcing member arranged in the inner cavity of the elastic layer; the reinforcing member is a cylindrical body formed by winding a longitudinal elastic member, the cylindrical body is located in the inner cavity of the elastic layer, and the axial direction of the cylindrical body is in the same direction as the axial direction of the tubular cavity, the longitudinal direction of the elastic member is a second longitudinal direction, and the elastic member can be elastically deformed in the second longitudinal direction.

Description

Technical Field

[0001] The present invention relates to a sheath for use with catheter-based techniques for repairing and / or replacing heart valves, and for delivering implants, such as prosthetic valves, to the heart via the vasculature of a patient. Background Art

[0002] Intravascular delivery catheter assemblies are used to implant prosthetic devices (such as prosthetic valves) into locations in the body that are not easily accessible by surgery or where minimally invasive surgery is desired. For example, aortic, mitral, tricuspid, and / or pulmonary prosthetic valves can be delivered to the treatment site using minimally invasive surgical techniques.

[0003] The introducer sheath is used to safely introduce the delivery device into the patient's vasculature (e.g., the femoral artery). The introducer sheath generally has an elongated sleeve that is inserted into the vasculature and a housing containing one or more sealing valves that allow the delivery device to be placed in fluid communication with the vasculature with minimal blood loss. Once the introducer sheath is positioned within the vascular system, the shaft of the delivery device is advanced through the sheath and carries the prosthetic device into the vascular system.

[0004] Since the introducer is used to facilitate the insertion of the medical device into the blood vessel, the trauma to the blood vessel can be reduced by minimizing the size of the introducer. Some medical device manufacturers have also designed some radially deformable introducers, which have a smaller outer size when inserted into the vascular system and can be radially expanded as needed when guiding the medical device.

[0005] The Chinese invention patent application No. 201780027828.8 published on December 21, 2018, discloses a radially expandable introducer. The introducer has a tearable outer layer and a folded inner layer located in the inner cavity of the outer layer. When the delivery device carries the medical device through the introducer, the outer layer of the introducer is torn at a weak point, and the folded inner layer is expanded, thereby expanding the radial size of the introducer.

[0006] Chinese Patent Invention Application No. 201880040805.5, published on February 7, 2020, discloses a radially expandable expandable sheath, which includes an elastic outer layer and a folded inner layer located in the inner cavity of the elastic outer layer. When the delivery device carries the medical device through the expandable sheath, the outer layer radially expands elastically and the folded inner layer unfolds, thereby expanding the radial size of the expandable sheath.

[0007] Since expandable sheaths have the advantage of significantly reducing blood vessel trauma compared to non-expandable sheaths, further research and development of expandable sheaths is still necessary. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide an expandable sheath with a simple structure.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: an expandable sheath, which is a longitudinally elongated sheath with a tubular cavity, wherein the longitudinal direction is the axial direction, and the direction perpendicular to the axial direction is the radial direction; the expandable sheath comprises an elastic layer which can be elastically deformed radially and forms an inner cavity, and a reinforcing member arranged in the inner cavity of the elastic layer; the reinforcing member is a cylindrical body formed by winding a longitudinally elongated elastic member, the cylindrical body is located in the inner cavity of the elastic layer, and the axial direction of the cylindrical body is in the same direction as the axial direction of the tubular cavity, the longitudinal direction of the elastic member is a second longitudinal direction, and the elastic member can be elastically deformed in the second longitudinal direction.

[0010] Compared with the prior art, the present invention has the following beneficial effects: the expandable sheath of the present invention is an elastic layer with an inner cavity and a reinforcing member located in the inner cavity of the elastic layer, and the reinforcing member is a cylindrical body formed by winding a longitudinal elastic member; the expandable sheath of the present invention can not only be elastically deformed in the radial direction, but also has a simple structure compared with the prior art.

[0011] Preferably, when the expandable sheath is in a radially unexpanded state, two adjacent circles of the elastic member abut against each other in the axial direction.

[0012] Preferably, the expandable sheath comprises a lubricating layer disposed within the inner cavity of the cylinder.

[0013] In one embodiment, the material of the lubricating layer is selected from one or more of polyurethane, silicone, rubber, fluoropolymer, TPE, and PEBAX.

[0014] In one embodiment, the elastic layer is made of silicone, rubber, TPU, TPE or PEBAX.

[0015] Preferably, the elastic member is a spring wound around the second longitudinal direction.

[0016] The present invention also provides an introducer, which comprises the expandable sheath.

[0017] The present invention also provides a method for using the above-mentioned introducer, which includes the following steps: using a guide member to pass through the lumen of the expandable sheath and protrude out of the distal end of the expandable sheath; under the guidance of the guide member, allowing the expandable sheath to pass through the lumen or blood vessel of the human body to reach a predetermined position; withdrawing the guide member through the expandable sheath, and leaving the expandable sleeve in the lumen or blood vessel of the human body to provide an instrument channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1is a three-dimensional schematic diagram of the introducer of the present invention;

[0019] Figure 2 is an exploded schematic diagram of an embodiment of the expandable sheath of the present invention;

[0020] Figure 3 is a schematic diagram of a reinforcement member of the present invention in an uncoiled state;

[0021] Figure 4 It is a partial cutaway schematic diagram of the expandable sheath of the present invention;

[0022] Figure 5 It is a cross-sectional schematic diagram of the expandable sheath of the present invention in a state of not radially expanding;

[0023] Figure 6 It is a cross-sectional schematic diagram of the expandable sheath of the present invention in a radially expanded state;

[0024] Figure 7 is a schematic diagram of a guide member assembled in the introducer;

[0025] Figure 8 A schematic diagram of the guide. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, but the scope of protection of the present invention is not limited. The term "proximal end" refers to the end close to the handheld operation, and the opposite "distal end" refers to the end close to the treatment position (such as the heart) after entering the human body. The terms "first" and "second" are only used to simplify the text description to distinguish similar objects, and cannot be understood as a specific order of precedence or importance.

[0027] Embodiment 1

[0028] See also Figure 1 As shown, Figure 1 1 is a three-dimensional schematic diagram of an introducer 100 of the present invention, which includes an elongated expandable sheath 1 and a housing assembly 2 located at the proximal end of the expandable sheath 1. A hemostatic valve can be installed at the proximal end of the housing assembly 2, and the distal end of the housing assembly 2 is connected to the proximal end of the expandable sheath 1. Both the housing assembly 2 and the expandable sheath 1 have lumens, and the lumens of the connected housing assembly 2 and the expandable sheath 1 are interconnected to form a passage for the delivery system.

[0029] See also Figure 2 As shown, Figure 2It is a schematic diagram of the exploded view of the expandable sheath of the present invention. The expandable sheath 1 is a longitudinal shape having a tubular cavity 10, wherein the longitudinal direction is the axial direction x, and the direction perpendicular to the axial direction x is the radial direction y. The expandable sheath 1 comprises an elastic layer 11 and a reinforcing member 12 assembled in the elastic layer 11. The elastic layer 11 can be made of materials such as silicone, rubber, TPU (thermoplastic urethanes), TPE (Thermoplastic Elastomer) or PEBAX (polyether block polyamide). The elastic layer 11 is a hollow structure, thereby forming an inner cavity for assembling the reinforcing member 12. Since the elastic layer 11 is elastic, it can be elastically deformed in the radial direction.

[0030] Please combine Figure 2 and Figure 3 As shown, Figure 3 This is a schematic diagram of the reinforcement member of the present invention in an uncoiled state. Please note that Figure 3 Only a section of the unwound reinforcement member is schematically shown, not the entire length. The reinforcement member 12 is a cylindrical body formed by winding a longitudinal elastic member. The longitudinal direction z of the elastic member is the second longitudinal direction, and the elastic member can be elastically deformed in the second longitudinal direction. In this embodiment, the elastic member is a longitudinal spring, but the elastic member of the present invention is not limited to a spring, as long as it is an element that can be elastically deformed in the second longitudinal direction. Figure 2 The figure shows the state where the elastic member is coiled as a reinforcement member. Figure 3 The elongated elastic member shown in the figure surrounds Figure 2 The axis x'-x' shown in is coiled to form a cylinder, and the x'-x' direction becomes the axial direction of the cylinder. Since the cylinder is formed by the coiling of the elastic member, each circle forming the circumference of the cylinder can be elastically deformed in the radial direction of the cylinder, and the elastic deformation is the result of the elastic deformation of the elastic member in the second longitudinal direction. Since each circle forming the circumference of the cylinder can be elastically deformed in the radial direction of the cylinder, the entire cylinder can be elastically deformed in the radial direction. A preferred embodiment is that two adjacent circles formed by the coiling of the elastic member abut against each other, in other words, two adjacent rings forming the cylinder abut against each other. With such an arrangement, the rigidity of the cylinder in the axial direction of the cylinder can be improved, that is, the cylinder is not easily compressed in the axial direction.

[0031] There are two main ways to form the expandable sheath 1 with the reinforcing member 12 and the elastic layer 11. The first is that the elastic member is coiled to form a cylindrical reinforcing member 12, the elastic layer 11 is formed separately, and then the reinforcing member 12 is assembled into the inner cavity of the elastic layer 11. The axial direction of the cylinder coincides with the axial direction of the inner cavity of the elastic layer 11. The second is that after the elastic member is coiled to form the cylindrical reinforcing member 12, an elastic material is coated, poured or slurried on the outer surface of the reinforcing member 12 to form the elastic layer 11. Figure 4 1 is a schematic diagram of a partial cross-section of the expandable sheath, which shows that the reinforcing member 12 is located in the lumen of the elastic layer 11 .

[0032] See also Figure 5 and Figure 6 As shown, Figure 5 is a cross-sectional schematic diagram of the expandable sheath in a non-radially expanded state, Figure 6 It is a cross-sectional schematic diagram of the expandable sheath in a radially expanded state. When a delivery system with a larger radial dimension or a replacement prosthesis with a larger radial dimension enters the expandable sheath, a radial force is applied to the reinforcing member 12, and the reinforcing member 12 elastically expands in the radial direction, and the elastic layer 11 also elastically expands accordingly, so that the inner cavity of the expandable sheath 1 becomes larger in the radial direction, allowing the delivery system or replacement prosthesis to pass through. When the delivery system completes the delivery, the expandable sheath 1 elastically shrinks in the radial direction and returns to its original size.

[0033] Embodiment 2

[0034] The difference between the second embodiment and the first embodiment is that the expandable sheath 1 further includes a lubricating layer, which is disposed in the cavity of the reinforcement 12. The lubricating layer can be formed by coating a lubricant in the inner cavity of the reinforcement 12, or by first forming a coating layer in the inner cavity of the reinforcement 12 and then spraying the lubricant on the inner wall of the coating layer. The material of the lubricant can be a combination of one or more of polyurethane, silicone, rubber, fluorine-containing polymer, TPE (Thermoplastic Elastomer), and PEBAX (polyether block polyamide).

[0035] The present invention also provides an introducer 100, see Figure 1 , Figure 7 and Figure 8 As shown, Figure 7 is a schematic diagram of the guide 100 in which the guide member 3 is assembled; Figure 8: is a schematic diagram of the guide member 3. The guide member 3 includes a longitudinal main body 31 and a tip 32 located at the distal end of the main body 31. When the introducer 100 is used, the tip 32 of the guide member 3 is first inserted from the proximal end of the introducer housing assembly 2 until the tip 32 protrudes out of the distal end of the expandable sheath 1. Then the introducer 100 assembled with the guide member 3 is inserted from the incision of the blood vessel of the human body. Under the guidance of the guide member 3, the guide member 100 enters the blood vessel and gradually penetrates deeper until it reaches the predetermined position. After reaching the predetermined position, the guide member 3 is withdrawn. At this time, the expandable sheath 1 remains in the blood vessel, and the housing assembly 2 is left outside the human body, so that the housing assembly 2 and the expandable sheath 1 jointly establish a channel, which not only allows the conveying system to pass through, but also allows the radial elastic deformation of the channel to allow the conveying system or replacement prosthesis with a larger radial size to pass through, thereby reducing the trauma to the blood vessel.

[0036] The present invention also provides a method for using the introducer 100, which includes the following steps: using a guide member 3 to pass through the lumen of the expandable sheath 1 and protrude out of the distal end of the expandable sheath 1; under the guidance of the guide member 3, the expandable sheath 1 passes through the lumen or blood vessel of the human body to reach a predetermined position; the guide member 3 is withdrawn through the expandable sheath 1, and the expandable sleeve 1 is left in the lumen or blood vessel of the human body to provide an instrument channel.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Therefore, although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An expandable sheath, characterized in that: The expandable sheath is in a longitudinal shape with a lumen, the longitudinal direction of which is the axial direction, and the direction perpendicular to the axial direction is the radial direction; The expandable sheath comprises an elastic layer which can be elastically deformed radially and forms an inner cavity, and a reinforcing member arranged in the inner cavity of the elastic layer; The reinforcing member is a cylindrical body formed by winding a longitudinal elastic member, the cylindrical body is located in the inner cavity of the elastic layer, and the axial direction of the cylindrical body is in the same direction as the axial direction of the lumen, the longitudinal direction of the elastic member is the second longitudinal direction, and the elastic member can be elastically deformed in the second longitudinal direction; Wherein, the elastic member is a spring wound around the second longitudinal direction, two adjacent circles formed by the spring being wound are in contact with each other, and a plurality of the circles are in contact with each other to form the cylindrical body; The expandable sheath includes a lubricating layer disposed within the inner cavity of the cylinder.

2. The expandable sheath according to claim 1, characterized in that: The material of the lubricating layer is selected from one or more of polyurethane, silicone, rubber, fluoropolymer, TPE, and PEBAX.

3. The expandable sheath according to claim 1, characterized in that: The elastic layer is made of silicone, rubber, TPU, TPE or PEBAX.

4. An introducer, characterized in that: Comprising an expandable sheath as claimed in any one of claims 1 to 3.

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