An adaptive catheter sheath

Abstract

The application discloses a self-adaptive catheter sheath, and relates to a catheter sheath which comprises a tube wall and an elastic polymeric sleeve covering the outer side of the tube wall; the tube wall is circular or elliptical in cross section with overlapping areas; the tube wall has two working modes: a predetermined mode of self-recovery and an expanded mode under the support of radial external force; when the tube wall is in the expanded mode, the overlapping areas of the tube wall slide and expand in diameter, and the tube wall still retains part of the overlapping structure after expansion. The initial predetermined tube diameter is only 4-6 mm, which is suitable for the slender blood vessels of Asian people, reduces the risk of calcified blood vessel plaque shedding, widens the applicable patients and reduces the risk of thrombosis; only the instrument passage section is temporarily expanded in diameter, and the instrument is retracted immediately after passing through, so that the blood vessel is prevented from being subjected to the expansion stress for a long time, and complications such as blood vessel spasm, lamination and rupture are reduced; the outer elastic polymeric sleeve has the triple functions of sealing, preventing seepage and synchronous expansion and rebounding, and realizes the self-adaptive repeated diameter change of the sheath tube.

Description

Technical Field

[0001] This invention relates to a catheter sheath, specifically an adaptive catheter sheath. Background Technology

[0002] Currently, most catheter sheaths used in clinical practice have a fixed outer diameter. The selection of a suitable sheath must match the maximum outer diameter of the delivery tube, resulting in an overall diameter that is too large. For patients with thin blood vessels or calcification of the blood vessel walls, the insertion of a large-diameter catheter sheath can easily cause vascular dissection and detachment of calcified plaques. Furthermore, prolonged dilation of blood vessels can lead to vasospasm, significantly increasing the probability of surgical complications. Summary of the Invention

[0003] The purpose of this invention is to provide an adaptive catheter sheath to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: An adaptive catheter sheath includes a tube wall and an elastic polymer sleeve covering the outside of the tube wall; The cross-section of the pipe wall is circular or elliptical with overlapping areas. The pipe wall has two working modes: a predetermined mode of self-recovery and an expansion mode under radial external force. When the pipe wall is in the expansion mode, the overlapping areas of the pipe wall slide against each other to expand the diameter, and the pipe wall still retains part of the overlapping structure after expansion. The elastic polymer sleeve is fitted to the outer wall of the tube. The elastic polymer sleeve can expand radially synchronously with the tube wall and provide a uniform radial contraction force after the radial external force disappears, driving the tube wall to return to the predetermined shape. At the same time, the elastic polymer sleeve seals the overlapping gaps of the tube wall to form a closed fluid channel to prevent blood leakage.

[0005] As a further aspect of the present invention: the outer diameter of the pipe wall in the predetermined state is 4-6 mm and the inner diameter is 3-5 mm; the inner diameter of the pipe wall in the expanded state can be expanded to 5-9 mm.

[0006] As a further embodiment of the present invention: the pipe wall is made of HDPE or Pebax material, the pipe wall thickness is 0.3-1.0mm, and the Shore D hardness of the pipe wall is 60-90.

[0007] As a further embodiment of the present invention: the elastic polymer sleeve is selected from one of ultra-high molecular weight polyethylene, high molecular weight polyethylene, polyetheretherketone, and elastic nylon; the sleeve thickness is 0.1-0.2 mm.

[0008] As a further aspect of the present invention: the outer wall of the elastic polymer sleeve is provided with a lubricating coating, and the lubricating coating material is one of PTFE, polyethylene, and polyvinylidene fluoride.

[0009] As a further embodiment of the present invention: the outer surface, inner surface, and outer surface of the elastic polymer sleeve are all provided with an elastic hydrophilic coating; The elastic hydrophilic coating is a covalently grafted elastic composite coating, selected from any one of the following: 1) Polyvinylpyrrolidone combined with a medical-grade elastic polyurethane base coating; 2) High-molecular-weight polyacrylamide combined with an elastic silane base coating; 3) Hyaluronic acid combined with elastic TPU composite coating.

[0010] As a further embodiment of the present invention: a contrast ring is provided at the distal end of the catheter sheath.

[0011] As a further embodiment of the present invention, it also includes a proximal sheath seat, a hemostatic valve, a dust cap, and a dilator; the catheter sheath is equipped with a puncture needle and an interventional guidewire kit.

[0012] An interventional device delivery device includes an interventional device and any of the aforementioned adaptive catheter sheaths; when the interventional device passes through the internal channel of the adaptive catheter sheath, a radial thrust is applied to the tube wall to cause the tube wall and the elastic polymer sheath to expand synchronously; after the interventional device is removed, the elastic polymer sheath uses its own elasticity to drive the tube wall to contract and return to a predetermined shape.

[0013] Compared with the prior art, the beneficial effects of the present invention are: ① The initial design has a small tube diameter, with an outer diameter of only 4-6mm, which can be adapted to the slender inferior vena cava of Asian people and expand the range of applicable patients; the small tube diameter during the insertion stage means that when it comes into contact with calcified aortic vessels, it will not compress calcified plaques over a large area, avoid plaque detachment and thrombus formation, and significantly reduce the risk of valve replacement surgery.

[0014] ② The dilation is only temporary at the location where the interventional device passes, and the vessel wall immediately contracts and resets after the device passes, without maintaining a large diameter throughout the entire process; this eliminates the continuous dilation stress caused by the long-term expansion of blood vessels by traditional fixed thick sheaths, effectively reducing surgical complications such as vasospasm, vascular dissection, and vascular rupture.

[0015] ③ The elastic polymer sheath covers the outside of the overlapping tube wall, filling the gap between the overlapping tube walls and forming a complete and sealed channel to avoid blood leakage during the operation; it has high elasticity and expands synchronously with the tube wall to ensure the smooth passage of large-sized delivery sheaths; after the instrument is withdrawn, it provides uniform radial contraction force, which drives the overlapping tube wall to retract autonomously to the initial state of the small diameter, realizing repeated adaptive switching.

[0016] ④ The hydrophilic coating on the outer wall of the sheath reduces frictional resistance when inserting the device into the blood vessel, reducing scratches on the inner wall of the blood vessel during puncture and catheterization; the hydrophilic coating on the inner wall of the sheath reduces sliding friction between the device and the interventional instrument, making the insertion and removal of the instrument smoother and simplifying the surgical procedure; the coating adopts a high-resilience covalent grafting system, which is not easy to fall off as the sheath expands and contracts, maintaining a long-lasting lubrication effect and improving the safety of the entire surgical procedure.

[0017] ⑤ The overlapping structure is retained in both the contraction and expansion states of the vessel wall, allowing for repeated expansion and contraction. The structure is not prone to failure and has a stable service life. It can be equipped with a distal contrast ring, hemostatic valve, dilator, puncture guide wire and other conventional interventional accessories, and is compatible with various endovascular interventional surgeries such as aortic valve and pulmonary valve replacement. The vessel wall and cannula materials take into account strength, flexibility and resilience, as well as intraoperative support and vascular compliance. Attached Figure Description

[0018] Figure 1 This is an isometric view of the catheter sheath of the present invention.

[0019] Figure 2 This is a cross-sectional view of the catheter sheath of the present invention in a predetermined configuration.

[0020] Figure 3 This is a cross-sectional view of the catheter sheath in the expanded state according to the present invention.

[0021] Figure 4 This is a schematic diagram of an interventional device.

[0022] Figure 5 A schematic diagram showing the state before the interventional device is inserted into the catheter sheath of this invention.

[0023] In the diagram: 1. Elastic polymer sleeve; 2. Pipe wall. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] Please refer to the attached figure. An adaptive catheter sheath is provided. The core of this adaptive catheter sheath consists of two main parts: a tube wall 2 and an elastic polymer sheath 1 covering the outside of the tube wall 2. It is also equipped with various conventional supporting components and is adapted for use in endovascular interventional surgery.

[0029] In addition to the core sheath structure, the catheter sheath also includes a proximal sheath seat, hemostatic valve, dust cap, and dilator; the complete set of instruments is also equipped with a puncture needle and interventional guidewire kit. If clinical surgery requires contrast localization, a contrast ring can be added to the distal end of the catheter sheath to facilitate intraoperative confirmation of the sheath implantation location.

[0030] The cross-section of the tube wall 2 is designed as a circular or elliptical structure with overlapping areas. It has two freely switchable working modes: a predetermined mode and an expanded mode. The switching between the two modes is achieved by external force and its own material properties. Pre-determined configuration: This is the original state of the catheter sheath when it leaves the factory, and it is also the initial shape when it is inserted into the patient's vascular wound along the guidewire. After the external radial force disappears, the tube wall 2 can also spontaneously rebound to return to this shape. In this state, the outer diameter of the tube wall 2 is controlled at 4-6mm, and the inner diameter is 3-5mm. The overall tube diameter is relatively small, making it easier to insert into patients with thin tubes and calcified blood vessels, reducing the risk of vascular damage.

[0031] Expanded State: When the interventional device passes through the internal channel of tube wall 2, the device applies a radial force to the inner wall of tube wall 2. The overlapping areas on tube wall 2 slide against each other, and the overall inner diameter is expanded, entering the expanded state. It is worth noting that even when fully expanded, tube wall 2 will still retain some overlapping structures and will not completely separate. This design ensures that tube wall 2 will not fail after repeated expansion and contraction, stably achieving the switching between the two states. In the expanded state, the inner diameter of tube wall 2 can expand to a maximum of 5-9 mm, which can smoothly pass through clinical 16F-24F valve delivery sheaths.

[0032] The tube wall 2 is made of HDPE or Pebax material with a thickness ranging from 0.3 to 1.0 mm, with 0.4 to 0.6 mm being the preferred thickness. The Shore D hardness of the tube wall ranges from 60 to 90, with 80 to 90 being the most common range, taking into account the resilience, structural strength, and vascular adaptability.

[0033] The elastic polymer sleeve 1 fits tightly against the outer wall of the tube wall 2, and works in conjunction with the tube wall 2 to achieve adaptive expansion and contraction, mainly undertaking three core functions: First, it expands radially in sync with the pipe wall 2, providing elastic support for the expansion of the pipe wall 2 and preventing deformation and damage when the pipe wall is stretched open by force. Second, after the interventional device is withdrawn and the radial external force disappears, the cannula relies on its own elasticity to provide a uniform inward contraction force, pulling the overlapping area of ​​the cannula wall 2 to slide and close, allowing the cannula wall 2 to automatically return to the predetermined shape. Third, the tube wall 2 itself has overlapping gaps. After the cannula completely wraps around the outside, it can seal the gaps and form a complete and sealed fluid channel to prevent blood from leaking out of the gaps during the operation.

[0034] The elastic polymer sheath 1 can be made of any one of the following materials: ultra-high molecular weight polyethylene, high molecular weight polyethylene, polyetheretherketone, or elastic nylon, with an elastic modulus of 400 MPa or above; the sheath thickness is set to 0.1-0.2 mm, and it should be made as thin as possible while ensuring elastic deformation and self-recovery performance, thereby reducing the overall outer diameter of the sheath.

[0035] An additional lubricating coating is provided on the outer wall of the elastic polymer sheath 1. The coating can be selected from PTFE, polyethylene, or polyvinylidene fluoride. This coating can reduce the friction between the sheath and the blood vessel, making it easier to insert the sheath into the blood vessel and reducing blood vessel scratches.

[0036] To further reduce frictional damage during cannulation and instrument delivery, the outer surface of the elastic polymer sleeve 1, the inner surface of the tube wall 2, and the outer surface of the tube wall 2 are all coated with an elastic hydrophilic coating.

[0037] Considering the repeated expansion and contraction of the sleeve, ordinary coatings are prone to peeling off. Therefore, an elastic composite coating that can be covalently grafted onto the substrate surface is selected, with three optional formulations: Polyvinylpyrrolidone combined with a medical-grade elastic polyurethane base coating is compatible with PEBAX, medical TPU, and nylon outer tubes. High-molecular-weight polyacrylamide combined with an elastic silane base coating results in higher cross-linking density and tensile resilience ≥96%. Hyaluronic acid combined with an elastic TPU composite coating mimics the structure of the human blood vessel endothelium, resulting in better biocompatibility.

[0038] This solution also provides an interventional device delivery device, which includes interventional devices and any of the adaptive catheter sheaths mentioned above.

[0039] The entire process of the device is as follows: During the procedure, the adaptive catheter sheath is first inserted into the patient's blood vessel in a predetermined shape; then the interventional device is pushed along the internal channel of the catheter sheath. The outer diameter of the device will continuously squeeze the inner wall of the tube wall 2, generating radial thrust, which drives the tube wall 2 and the outer elastic polymer sheath 1 to expand outward synchronously, and the maximum outer diameter of the adapter device can pass smoothly. Once the interventional device has completely exited the catheter sheath and withdrawn outward, the tube wall 2 no longer bears radial thrust. The outer elastic polymer sheath 1 relies on its own elastic contraction to pull the overlapping area of ​​the tube wall 2 together, allowing the entire tube wall to quickly contract and return to the predetermined shape with a small diameter. This reduces the stimulation caused by prolonged vascular dilation and lowers surgical complications such as vascular spasm, dissection, and calcified plaque detachment.

[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An adaptive catheter sheath, characterized in that, Includes a pipe wall (2) and an elastic polymer sleeve (1) covering the outside of the pipe wall (2); The cross-section of the pipe wall (2) is a circle or ellipse with overlapping areas. The pipe wall (2) has two working modes: a predetermined mode of self-recovery and an expansion mode under radial external force. When the pipe wall (2) is in the expansion mode, the overlapping areas of the pipe wall (2) slide to expand the diameter, and the pipe wall (2) still retains a part of the overlapping structure after expansion. The elastic polymer sleeve (1) is fitted to the outer wall of the tube wall (2). The elastic polymer sleeve (1) can expand radially synchronously with the tube wall (2) and provide uniform radial contraction force after the radial external force disappears, driving the tube wall (2) to return to the predetermined shape. At the same time, the elastic polymer sleeve (1) closes the overlapping gap of the tube wall (2) to form a closed fluid channel to prevent blood leakage.

2. The adaptive catheter sheath according to claim 1, characterized in that, The outer diameter of the pipe wall (2) in the predetermined state is 4-6 mm and the inner diameter is 3-5 mm; the inner diameter of the pipe wall (2) in the expanded state can be expanded to 5-9 mm.

3. The adaptive catheter sheath according to claim 1, characterized in that, The pipe wall (2) is made of HDPE or Pebax material, and the thickness of the pipe wall (2) is 0.3-1.0mm; the Shore D hardness of the pipe wall (2) is 60-90.

4. The adaptive catheter sheath according to claim 1, characterized in that, The elastic polymer sleeve (1) is selected from one of ultra-high molecular weight polyethylene, high molecular weight polyethylene, polyether ether ketone, and elastic nylon; the sleeve thickness is 0.1-0.2 mm.

5. The adaptive catheter sheath according to claim 1, characterized in that, The outer wall of the elastic polymer sleeve (1) is provided with a lubricating coating, and the lubricating coating material is one of PTFE, polyethylene, and polyvinylidene fluoride.

6. The adaptive catheter sheath according to claim 1, characterized in that, The outer surface of the elastic polymer sleeve (1), the inner surface of the tube wall (2), and the outer surface of the tube wall (2) are all provided with an elastic hydrophilic coating; The elastic hydrophilic coating is a covalently grafted elastic composite coating, selected from any one of the following: 1) Polyvinylpyrrolidone combined with a medical-grade elastic polyurethane base coating; 2) High-molecular-weight polyacrylamide combined with an elastic silane base coating; 3) Hyaluronic acid combined with elastic TPU composite coating.

7. The adaptive catheter sheath according to claim 1, characterized in that, A contrast ring is provided at the distal end of the catheter sheath.

8. The adaptive catheter sheath according to claim 1, characterized in that, It also includes a proximal sheath seat, a hemostatic valve, a dust cap, and a dilator; the catheter sheath is equipped with a puncture needle and an interventional guidewire kit.

9. An interventional instrument delivery device, characterized in that, Includes interventional devices and the adaptive catheter sheath as described in any one of claims 1-8; When the interventional device passes through the internal channel of the adaptive catheter sheath, it applies a radial thrust to the tube wall (2) to make the tube wall (2) and the elastic polymer sheath (1) expand synchronously; after the interventional device is removed, the elastic polymer sheath (1) drives the tube wall (2) to contract and reset to the predetermined shape by its own elasticity.

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