A delivery sheath

Abstract

The utility model discloses a kind of delivery sheaths, it is related to medical instrument technical field, including sheath tube, sheath tube has sheath tube distal end first curved section, sheath tube distal end second curved section, sheath tube distal end third curved section and sheath tube main body section in turn from the distal end of sheath tube to the proximal end of sheath tube on sheath tube, the center line of sheath tube distal end first curved section and the center line of sheath tube distal end second curved section are on first plane, the center line of sheath tube distal end third curved section and the center line of sheath tube main body section are on second plane, the included angle between second plane and first plane is greater than 0 and less than 90 °;The center line of sheath tube distal end third curved section can be parallel with the center line of aortic arch, the outlet on sheath tube distal end first curved section can be directly opposite aortic valve orifice;The utility model can effectively avoid blood vessel or valve injury.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a delivery sheath. Background Technology

[0002] The delivery sheath plays a crucial role in medical device interventions. As an interventional tool, it establishes a surgical pathway, providing a safe and effective route to guide and support the device into its target location, ensuring stability and accuracy during the intervention. Without a delivery sheath, intervention would face numerous difficulties. Furthermore, the delivery sheath reduces surgical trauma; by using it, surgeons can perform procedures more precisely, thereby reducing the risk of trauma and complications for the patient.

[0003] In interventional procedures, a fixed bend in the delivery sheath is necessary. Existing curved delivery sheaths are usually used in situations where a change in delivery direction is required but the degree of curvature is not significant. When used to deliver medical devices to the left ventricle, they are difficult to pass through the aortic arch, tend to stick tightly to the vessel wall, and the distal end of the sheath cannot be aligned with the aortic valve orifice. This makes it impossible to guarantee that the device will be aligned with the aortic valve orifice after exiting the sheath, which can easily cause damage to the vessel or valve. Utility Model Content

[0004] The purpose of this invention is to provide a delivery sheath to solve the problems existing in the prior art and to effectively avoid damage to blood vessels or valves.

[0005] To achieve the above objectives, this utility model provides the following solution:

[0006] This utility model provides a delivery sheath, including a sheath tube. The sheath tube has, from its distal end to its proximal end, a first-order distal bending segment, a second-order distal bending segment, a third-order distal bending segment, and a main body segment. The centerline of the first-order distal bending segment and the centerline of the second-order distal bending segment lie on a first plane, and the centerline of the third-order distal bending segment and the centerline of the main body segment lie on a second plane. The angle between the second plane and the first plane is greater than 0° and less than 90°. The centerline of the third-order distal bending segment is parallel to the centerline of the aortic arch, and the outlet on the first-order distal bending segment is directly opposite the aortic valve orifice.

[0007] Preferably, the distal primary bending section, the distal secondary bending section, the distal tertiary bending section, and the main body section of the sheath are connected in a smooth transition sequence.

[0008] Preferably, the angle between the second plane and the first plane is 55° to 65°; the first-order curved section at the distal end of the sheath is straight, and the length of the first-order curved section at the distal end of the sheath is 14mm to 16mm; the second-order curved section at the distal end of the sheath is arc-shaped, and the radius of the second-order curved section at the distal end of the sheath is 41mm to 43mm, with a central angle of 90° to 100°; the third-order curved section at the distal end of the sheath is arc-shaped, and the radius of the third-order curved section at the distal end of the sheath is 119mm to 121mm, with a central angle of 65° to 75°.

[0009] Preferably, the length of the sheath is 80cm to 150cm.

[0010] Preferably, the inner diameter of the sheath is 4F to 14F.

[0011] Preferably, it also includes an expander, which has, from its distal end to its proximal end, a first-order curved section, a second-order curved section, a third-order curved section, and a main body section, with the center lines of the first-order curved section, the second-order curved section, the third-order curved section, and the main body section lying on a third plane.

[0012] Preferably, the distal first-stage bending section, the distal second-stage bending section, the distal third-stage bending section, and the main body section of the expander are connected in a smooth transition sequence.

[0013] Preferably, the distal first-stage curved section of the expander is straight, the angle between the distal first-stage curved section and the main body of the expander is 40° to 50°, the length of the distal first-stage curved section is 6.5mm to 8.5mm, and the outer wall of the distal first-stage curved section gradually contracts inward in the direction away from the distal third-stage curved section; the distal second-stage curved section of the expander is arc-shaped, the radius of the distal second-stage curved section is 19mm to 21mm, the arc length of the distal second-stage curved section is 9mm to 11mm; the radius of the distal tertiary curved section of the expander is 59mm to 61mm, and the corresponding central angle is 73° to 83°.

[0014] Preferably, the length of the expander is 85cm to 155cm.

[0015] Preferably, the outer diameter of the expander is 4F to 14F, and the inner diameter of the expander is 0.889mm.

[0016] The present invention achieves the following technical advantages over the prior art:

[0017] The delivery sheath provided by this utility model is configured with, from the distal end to the proximal end of the sheath, a first-order curved section, a second-order curved section, a third-order curved section, and a main body section. The centerline of the first-order curved section and the centerline of the second-order curved section lie on a first plane, and the centerline of the third-order curved section and the centerline of the main body section lie on a second plane. The angle between the second plane and the first plane is greater than 0° and less than 90°. This allows the distal end, which would normally easily conform to the vessel wall, to extend to the middle of the aortic arch root and align with the aortic valve orifice. Through multiple bends on different planes, a spatial combination of curved structures is formed. The central line is parallel to the central line of the aortic arch, and the outlet on the first-order curved section of the distal end of the sheath is aligned with the aortic valve orifice. This allows the medical device to be smoothly guided across the aortic arch, ensuring that the device is aligned with the aortic valve orifice after exiting the sheath. With gentle manipulation, it can then smoothly enter the left ventricle, preventing valve damage. The sheath provided by this invention not only serves as a delivery channel for the medical device, but also prevents it from adhering to the vessel wall. Furthermore, the distal end of the sheath, located at the center of the blood vessel, provides support for the medical device, preventing it from adhering to the vessel wall and avoiding excessive friction or pressure between the sheath, the medical device, and the vessel wall, thus reducing the risk of bleeding and infection and effectively preventing damage to the blood vessel or valve. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the delivery sheath provided by this utility model;

[0020] Figure 2 A three-dimensional schematic diagram of the sheath tube in the delivery sheath provided by this utility model;

[0021] Figure 3 A schematic diagram of the sheath tube in one direction of the delivery sheath provided by this utility model;

[0022] Figure 4 A schematic diagram of the sheath tube in the delivery sheath provided by this utility model from another direction;

[0023] Figure 5 A schematic diagram of the curved section of the sheath tube in the conveying sheath provided by this utility model;

[0024] Figure 6 A schematic diagram of the expander in the delivery sheath provided by this utility model;

[0025] In the diagram: 1-Sheath, 11-First-order curved section of distal sheath, 12-Second-order curved section of distal sheath, 13-Third-order curved section of distal sheath, 14-Main body of sheath, 2-Expander, 21-First-order curved section of distal expander, 22-Second-order curved section of distal expander, 23-Third-order curved section of distal expander, 24-Main body of expander. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] The purpose of this invention is to provide a delivery sheath to solve the problems existing in the prior art and to effectively avoid damage to blood vessels or valves.

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The femoral artery is a common interventional site during surgery. After the delivery sheath is inserted through the femoral artery and passes through the relatively straight thoracic and abdominal aorta, it needs to be flipped over the curved aortic arch. After flipping over the aortic arch, the delivery sheath must be aligned with the aortic valve orifice so that the medical device being delivered can also be aligned with the aortic valve orifice after exiting the sheath. During this process, if the delivery sheath or device is not completely positioned in the middle of the artery, but sticks to the wall or scrapes against the aortic valve, it will cause tissue tearing, bleeding and other damage, or even damage or malfunction of the device.

[0030] like Figures 1 to 6 As shown, this utility model provides a delivery sheath, including a sheath tube 1. The sheath tube 1 has, from its distal end to its proximal end, a first-order curved section 11, a second-order curved section 12, a third-order curved section 13, and a main body section 14. The centerline of the first-order curved section 11 and the centerline of the second-order curved section 12 are on a first plane, and the centerline of the third-order curved section 13 and the centerline of the main body section 14 are on a second plane. The angle between the second plane and the first plane is greater than 0° and less than 90°. The centerline of the third-order curved section 13 is parallel to the centerline of the aortic arch, and the outlet on the first-order curved section 11 is directly opposite the aortic valve orifice.

[0031] The delivery sheath provided by this utility model is particularly suitable for intervention via the femoral artery, passing through the relatively straight thoracic and abdominal aorta, overcoming the curved aortic arch, and directly facing the aortic valve orifice. The sheath 1 is configured with, from its distal end to its proximal end, a first-order curved segment 11, a second-order curved segment 12, a third-order curved segment 13, and a main body segment 14. The centerline of the first-order curved segment 11 and the centerline of the second-order curved segment 12 lie in a first plane, while the centerline of the third-order curved segment 13 and the centerline of the main body segment 14 lie in a second plane. The angle between the second plane and the first plane is greater than 0° and less than 90°. This allows the distal end, which would normally easily conform to the vessel wall, to extend to the middle of the aortic arch root and align with the aortic valve orifice. Through multiple bends on different planes, a spatial combination of curved structures is formed. The centerline of the third-order curved segment 13... Parallel to the centerline of the aortic arch, the outlet of the distal first-order curved segment 11 of the sheath is aligned with the aortic valve orifice, allowing for smooth guidance of the medical device across the aortic arch. This ensures the device is directly aligned with the aortic valve orifice after exiting the sheath, facilitating gentle entry into the left ventricle and preventing valve damage. The sheath 1 of this invention not only serves as a delivery channel for the medical device, preventing it from adhering to the vessel wall, but its distal end, located at the center of the blood vessel, also provides support, preventing the device from adhering to the wall and avoiding excessive friction or pressure between the sheath 1, the medical device, and the vessel wall, thus reducing the risk of bleeding and infection. This effectively prevents damage to the blood vessel or valve. Furthermore, the distal end of the sheath 1 being aligned with the aortic valve orifice simplifies surgical procedures, improves surgical efficiency, enhances patient comfort, and promotes postoperative recovery.

[0032] The delivery sheath provided by this utility model is preferably made by thermoplastic bending process, but it can also be made of shape memory alloy material or shape memory polymer.

[0033] As a preferred embodiment of this invention, the distal primary bending segment 11, the distal secondary bending segment 12, the distal tertiary bending segment 13, and the main body segment 14 of the sheath are connected in a smooth transition sequence, which can effectively reduce abrasion and avoid vascular damage.

[0034] In a preferred embodiment of this invention, the angle between the second plane and the first plane is 55° to 65°; the distal primary bend 11 of the sheath is straight, with a length of 14mm to 16mm, to ensure it remains aligned with the aortic valve orifice during sheath advancement; the distal secondary bend 12 of the sheath is arc-shaped, with a radius of 41mm to 43mm and a central angle of 90° to 100°, to accommodate the distance between the aortic valve orifice and the aortic root vessel wall (approximately 20mm); the distal tertiary bend 13 of the sheath is arc-shaped, with a radius of 119mm to 121mm and a central angle of 65° to 75°, to facilitate passage through the aortic arch.

[0035] As a preferred embodiment of this invention, based on the anatomical structure of human blood vessels, the length of the blood vessel from the femoral artery puncture point to the target location is generally about 80cm, taking into account the possible tortuosity and twisting of the blood vessel, as well as facilitating surgical operation. The length of the sheath 1 is 80cm to 150cm.

[0036] As a preferred embodiment of this example, since the inner diameter of the femoral artery is about 8mm, the inner diameter of the thoracic and abdominal aorta is 10mm to 21mm, the inner diameter of the aortic arch is 20mm to 40mm, and the sheath 1 is used to deliver medical devices such as guidewires, catheters, and covered stents, the inner diameter of the sheath 1 is 4F to 14F.

[0037] Furthermore, the delivery sheath provided by this utility model also includes an expander 2. The expander 2 has, from its distal end to its proximal end, a first-stage curved section 21, a second-stage curved section 22, a third-stage curved section 23, and a main body section 24. The center lines of the first-stage curved section 21, the second-stage curved section 22, the third-stage curved section 23, and the main body section 24 lie on a third plane. The second-stage curved section 22 and the third-stage curved section 23 of the expander 2 cooperate with each other. Successfully pass through the aortic arch, ensuring that the distal end of dilator 2 is precisely aligned with the aortic valve orifice. In rare cases, due to factors such as the patient's aortic valve orifice being too narrow, unclear valve structure, redundant / adhesive / severe calcification of valve leaflets, or critically ill patients being unable to tolerate prolonged surgery, sheath 1 may not be aligned with the aortic valve orifice when facing the impact of high-speed blood flow, making subsequent operations difficult. In such cases, sheath 1 can be pushed to a position slightly further from the aortic root, while dilator 2, which has stronger support and a smaller distal diameter, is pushed to the aortic root first. At this time, due to its special curved shape, the distal end of dilator 2 can also be precisely aligned with the aortic valve orifice.

[0038] As a preferred embodiment of this invention, the distal first-stage bending segment 21, the distal second-stage bending segment 22, the distal third-stage bending segment 23, and the main body segment 24 of the expander are connected in a smooth transition sequence, which can effectively reduce abrasion and avoid vascular damage.

[0039] In a preferred embodiment of this invention, the distal first-order curved section 21 of the dilator is straight, with an angle of 40° to 50° between it and the main body section 24. The length of the distal first-order curved section 21 is 6.5 mm to 8.5 mm, serving to maintain direction. The outer wall of the distal first-order curved section 21 gradually contracts inward in a direction away from the distal third-order curved section 23, facilitating advancement within narrowed blood vessels. The distal second-order curved section 22 of the dilator is arc-shaped, with a radius of 19 mm to 21 mm and an arc length of 9 mm to 11 mm. The radius of the distal third-order curved section 23 is 59 mm to 61 mm, and the corresponding central angle is 73° to 83°, to accommodate the curvature radius and angle of the aortic arch and the diameter of the aortic root vessels.

[0040] As a preferred embodiment of this invention, since the expander 2 is generally located inside the sheath 1 and extends out of the sheath 1 at its distal end for expansion and development, the length of the expander 2 is set to be 85cm to 155cm.

[0041] As a preferred embodiment of this invention, the outer diameter of the dilator 2 is 4F to 14F, and the inner diameter of the dilator 2 is 0.889mm, which facilitates the passage of the guidewire. The cross-lobe is made of a 0.035-inch ultra-hard guidewire with good rigidity and flexibility.

[0042] Specifically, sheath 1 is the main body of the delivery sheath, and its design directly affects the performance and effectiveness of the entire delivery sheath. Sheath 1 is usually made of high-strength, corrosion-resistant, and biocompatible materials to ensure sufficient stability and durability during delivery. Its inner wall is smooth to reduce friction and resistance, thus facilitating the smooth passage of the delivered object. The soft material and smooth outer surface of sheath 1 reduce friction with blood vessels and tissues, protecting surrounding blood vessels and tissues from damage and reducing surgical risks and the incidence of complications. The dilator 2 is usually located inside sheath 1 and can extend to the distal end of sheath 1. The main function of dilator 2 is to open and expand the channel. When the delivery sheath needs to pass through narrow or blocked areas, dilator 2 can use the shape and rigidity of its distal end to expand these narrow areas by physical means (such as pushing, rotating, etc.), providing sufficient space for the subsequent sheath 1 and ensuring that it can reach the target position smoothly. Dilator 2 can also serve as a guide for sheath 1. Its distal end usually has a specific shape, which helps to maintain the correct orientation in complex or tortuous vascular structures. With the guidance of dilator 2, the travel path of sheath 1 can be controlled more accurately, improving the precision and safety of the operation.

[0043] Similar to conventional designs, in this embodiment, the sheath 1 consists of a sheath body, a sheath cap, a sheath seat, a silicone pad, a stress-diffusing tube, and an extension tube. The sheath body comprises three layers: a smooth inner layer, a middle reinforcing layer, and a plastic outer layer. The inner layer can be made of materials with low friction coefficients, such as polytetrafluoroethylene, high-density polyethylene, or ethylene-tetrafluoroethylene copolymer. The middle layer can be one or more metal materials, such as stainless steel or nickel-titanium. The outer layer can be made of biocompatible materials such as polyether block polyamide, polyurethane, or polyamide. The sheath cap is located at one end of the sheath body and serves to seal and protect the interior of the sheath body. It prevents external impurities from entering the sheath body and also provides some cushioning and support during transport. The sheath seat is another important part of the sheath 1. It is usually connected to the sheath body and serves to fix and support the sheath body. The design of the sheath base can be adjusted according to actual application needs to ensure that the conveying sheath can be stably installed in the required position; the silicone pad, as a soft and durable material, is often used in the conveying sheath to provide additional sealing and cushioning effects. It can effectively reduce vibration and impact during the conveying process, thereby protecting the conveyed object from damage; the stress diffusion tube is a component specially designed to disperse stress. During the conveying process, due to the influence of various factors (such as temperature, pressure, etc.), certain stress may be generated. The stress diffusion tube can effectively disperse these stresses to a larger area, thereby avoiding damage caused by excessive local stress; the extension tube, as an extension part of the conveying sheath, can be adjusted in length according to actual needs. It allows the conveying sheath to flexibly adapt to different application scenarios, ensuring that the conveyed object can smoothly reach the target position.

[0044] Similar to conventional designs, in this embodiment, the dilator 2 consists of a dilator catheter and a dilator seat. The dilator catheter is the main body of the dilator 2 and is typically made of biocompatible materials such as HDPE or LDPE. Its function is to guide and dilate. The dilator seat is another key component connected to the dilator catheter. It is usually located proximally and is made of a material with sufficient strength and durability. By mechanically pushing the dilator seat, it provides dilation force to open narrowed or blocked blood vessels, channels, or other anatomical structures.

[0045] It should be noted that during its journey within the blood vessel, sheath 1 is shaped by dilator 2 and the ultra-stiff guidewire, and after shaping, it enters essentially coaxial with the blood vessel. The structural difference between sheath 1 and dilator 2 lies in their respective functions. The in-plane curvature of dilator 2 facilitates coaxiality with the blood vessel under the shaping of the ultra-stiff guidewire, and consequently, ensures that sheath 1 is also coaxial with the blood vessel. After dilator 2 and sheath 1 are assembled, they enter the aorta together, crossing the aortic arch. Since the aortic arch and left ventricle do not form a planar curved structure, the anterior and posterior positions of sheath 1 need to be finely adjusted so that the distal end of dilator 2, guided by the pre-shaped curvature of sheath 1, is aligned with the aortic valve. Then, together, they enter the left ventricle under the protection of the guidewire to avoid valve damage. Once sheath 1 enters the valve, dilator 2 and guidewire are withdrawn from the left ventricle. Sheath 1 remains in the left ventricle to facilitate the entry of delivery devices. Before dilator 2 is withdrawn, sheath 1 is already in the left ventricle, so there is no need to worry about whether the distal end of sheath 1 is aligned with the aortic valve. As explained above, after adjusting the position of sheath 1 so that the opening of dilator 2 is aligned with the aortic valve opening, both are pushed together through the aortic valve into the left ventricle under the protection of the guidewire. Then, dilator 2 and guidewire are withdrawn from the body, and sheath 1 remains in the left ventricle awaiting the entry of the delivery device. The curved structure of sheath 1 fits snugly against the curved structure of the aorta, ensuring a stable position.

[0046] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A delivery sheath, characterized in that: The device includes a sheath, which, from its distal end to its proximal end, has sequentially formed a primary distal bending segment, a secondary distal bending segment, a tertiary distal bending segment, and a main body segment. The centerline of the primary distal bending segment and the centerline of the secondary distal bending segment lie in a first plane, and the centerline of the tertiary distal bending segment and the centerline of the main body segment lie in a second plane. The angle between the second plane and the first plane is greater than 0° and less than 90°. The centerline of the tertiary distal bending segment is parallel to the centerline of the aortic arch, and the outlet on the primary distal bending segment is directly opposite the aortic valve orifice.

2. The delivery sheath according to claim 1, characterized in that: The distal first-order curved section, the distal second-order curved section, the distal third-order curved section, and the main body of the sheath are smoothly connected in sequence.

3. The delivery sheath according to claim 2, characterized in that: The angle between the second plane and the first plane is 55° to 65°; the first-order curved section at the distal end of the sheath is straight, and the length of the first-order curved section at the distal end of the sheath is 14mm to 16mm; the second-order curved section at the distal end of the sheath is arc-shaped, and the radius of the second-order curved section at the distal end of the sheath is 41mm to 43mm, with a central angle of 90° to 100°; the third-order curved section at the distal end of the sheath is arc-shaped, and the radius of the third-order curved section at the distal end of the sheath is 119mm to 121mm, with a central angle of 65° to 75°.

4. The delivery sheath according to claim 3, characterized in that: The length of the sheath is 80cm to 150cm.

5. The delivery sheath according to claim 4, characterized in that: The inner diameter of the sheath is 4F to 14F.

6. The delivery sheath according to claim 5, characterized in that: It also includes an expander, which has, from its distal end to its proximal end, a first-order curved section, a second-order curved section, a third-order curved section, and a main body section. The center lines of the first-order curved section, the second-order curved section, the third-order curved section, and the main body section lie on a third plane.

7. The delivery sheath according to claim 6, characterized in that: The distal first-stage bending section, the distal second-stage bending section, the distal third-stage bending section, and the main body section of the expander are connected in a smooth transition sequence.

8. The delivery sheath according to claim 7, characterized in that: The distal first-stage curved section of the expander is straight, with an angle of 40°–50° between it and the main body of the expander. The length of the distal first-stage curved section is 6.5mm–8.5mm, and the outer wall of the distal first-stage curved section gradually contracts inward in the direction away from the distal third-stage curved section. The distal second-stage curved section of the expander is arc-shaped, with a radius of 19mm–21mm and an arc length of 9mm–11mm. The radius of the distal tertiary curved section of the expander is 59mm–61mm, and the corresponding central angle is 73°–83°.

9. The delivery sheath according to claim 8, characterized in that: The length of the expander is 85cm to 155cm.

10. The delivery sheath according to claim 9, characterized in that: The outer diameter of the expander is 4F to 14F, and the inner diameter of the expander is 0.889mm.

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