Conveying system

Abstract

The application provides a delivery system, which comprises an outer tube assembly and an inner tube assembly, a part of the inner tube assembly is arranged in the outer tube assembly, and the inner tube assembly and the outer tube assembly can move relatively, the inner tube assembly comprises an inner tube and a head end part, the head end part is arranged at the distal end of the inner tube, the head end part has at least a contracted state and an expanded state, and can be converted between the contracted state and the expanded state; after the head end part is contracted, the radial dimension of at least a part of the head end part is reduced; in this way, the secondary injury to the blood vessel can be reduced effectively, and the blood vessel complication can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a delivery system. Background Art

[0002] Heart valves are the gateways to blood circulation. Stenosis or incomplete closure can lead to insufficient heart power or failure, resulting in symptoms such as chest tightness, shortness of breath, generalized swelling, weakness, and chest pain. These conditions pose a significant threat to the lives and quality of life of the elderly. With an aging population and advances in medical technology, valvular heart disease (VHD) has become the third most common cardiovascular disease, severely endangering human health. Aortic stenosis (AS), for example, is one of the most common valvular heart diseases, and its incidence increases with age (2% annually for those aged >65, 3% annually for those aged >75, and 4% annually for those aged >85). Thirty-three percent of patients with aortic stenosis are untreatable, with a two-year mortality rate of 50% and a five-year mortality rate of 80%.

[0003] For patients with severe aortic stenosis, open-chest surgical aortic valve replacement with extracorporeal circulation was once the only treatment option to prolong their lives. Although complications and mortality rates from surgical aortic valve replacement have continued to decrease with advancements in surgery, anesthesia, and intensive care, the prognosis of the disease deteriorates dramatically once typical symptoms or clear left ventricular function decline develop. Current aortic stenosis treatment guidelines list this as an absolute indication for surgical valve replacement. Elderly patients are often contraindicated for surgery due to advanced age, frailty, severe lesions, or comorbidities, which limits the population for whom surgery is appropriate.

[0004] Over the past decade, internationally, transcatheter valve therapy has made significant progress through continuous exploration, becoming the most promising branch of interventional cardiology. This technology has been called the fourth revolution in cardiovascular intervention. A growing number of studies indicate that transcatheter valve therapy will be an important direction for the future development of heart valve therapy. The Society of Thoracic Surgeons and American College of Cardiology Transcatheter Valve Therapy (STS-ACC TVT) registry study showed that in 2019, the number of transcatheter aortic valve replacement procedures in the United States exceeded all forms of surgical aortic valve replacement for the first time, and has become one of the important treatments for symptomatic severe AS.

[0005] In recent years, minimally invasive transcatheter valvular disease interventional treatment has garnered increasing attention. With the advancement of transcatheter valvular disease interventional technology, new demands and challenges have emerged. For example, to improve surgical success rates or ensure the quality of valve prosthesis delivery, retrievable delivery systems are being adopted. Retrievable delivery systems require higher performance from the delivery catheter, resulting in a larger outer diameter. This larger outer diameter further increases the requirements for both vascular access and post-access transversal performance.

[0006] Before delivering the delivery system, transcatheter valvular disease interventional surgery requires the use of a catheter sheath to pre-dilate the blood vessels to establish a channel. The larger the outer diameter of the delivery catheter, the larger the diameter of the catheter sheath required. In order to reduce the overall outer diameter of the medical device, an inline catheter sheath technology is generally used. This technology involves wrapping the catheter sheath over the delivery catheter of the delivery system so that the catheter sheath is located between the sheath tube and the handle of the delivery system. The inner diameter of the catheter sheath is smaller than the outer diameter of the sheath tube, and a head end component is provided at the distal end of the sheath tube. The sheath tube can form a closure with the head end component to cover the valve prosthesis. During the loading and delivery stage of the valve prosthesis, the maximum outer diameter of the head end component is the same as the outer diameter of the sheath tube to meet the sealing requirements of the delivery system. When the valve prosthesis is delivered to the lesion site, the inner and outer tubes of the delivery system move relative to each other, and the valve prosthesis is released. After the release is completed, the inner and outer tubes are closed, and the delivery system is withdrawn. During the withdrawal stage, the inline catheter sheath is withdrawn together with the delivery system. However, in order for the valve prosthesis to better expand or fit the native tissue or other functional requirements, it is generally necessary to use the original vascular channel to deliver new accessory products such as balloons. In this process, since the inline catheter sheath has been withdrawn together with the delivery system, a new catheter sheath needs to be inserted to establish a pathway. Doing so increases the difficulty of the surgical operation on the one hand, and causes secondary damage to the blood vessels on the other hand. In addition to the inline catheter sheath technology, a split catheter sheath technology is also used. This technology separates the catheter sheath from the delivery system; during the delivery and withdrawal processes, the delivery system catheter passes through the catheter sheath. Due to the larger outer diameter of the delivery catheter, the surgical operation is more difficult, and there may even be a risk of the catheter sheath and the delivery system being withdrawn together, increasing the risk of secondary damage to the blood vessels, which needs to be solved together. In addition, in addition to heart valve prostheses, other implantable prostheses also have the problem of secondary damage to blood vessels when using a transcatheter delivery method. Summary of the Invention

[0007] The purpose of the present invention is to provide a delivery system to solve the problem of secondary damage to blood vessels existing in existing delivery systems.

[0008] To achieve the above-mentioned object, the present invention provides a conveying system, comprising an outer tube assembly and an inner tube assembly, wherein a portion of the inner tube assembly is disposed within the outer tube assembly, and the inner tube assembly and the outer tube assembly are capable of relative movement;

[0009] The inner tube assembly includes a head end component, which has at least a contracted state and an expanded state and can be switched between the contracted state and the expanded state; after the head end component is contracted, at least a portion of the radial dimension of the head end component is reduced.

[0010] Optionally, a ratio of a maximum radial dimension of the head end component in an expanded state to a maximum radial dimension of the head end component in a contracted state is not less than 1.05.

[0011] Optionally, the inner tube assembly further comprises an inner core, and the head end component is outer-mounted on the inner core.

[0012] Optionally, the head end component includes an expandable device, the expandable device is capable of retracting and contracting, and the head end component is capable of retracting and contracting along with the expandable device.

[0013] Optionally, the expandable device is a mesh support structure, at least one end of which is movably arranged relative to the inner core; the mesh support structure is woven from braided wire or cut from a tube, or the mesh support structure is composed of a plurality of foldable wave rods, and the plurality of wave rods are arranged at intervals along the circumferential direction.

[0014] Optionally, the inner tube assembly further includes an inner tube, the inner core is at least partially placed in the inner tube, the expandable device is composed of a plurality of foldable wave rods, the plurality of wave rods are arranged at intervals along the circumferential direction, and at least the proximal ends of a portion of the wave rods are connected to the distal end of the inner tube, and the distal ends of the wave rods are connected to the distal end of the inner core.

[0015] Optionally, the delivery system further comprises a manipulation component, and at least a portion of the proximal end of the wave rod is connected to the distal end of the manipulation component, and the manipulation component is used to control the folding and extension of the wave rod.

[0016] Optionally, the expandable device is an expandable body made of polymer material, the expandable body has an inner cavity for injecting filling medium, and the expandable body is fixed on the inner core; a channel for conveying filling medium is provided between the inner core and the expandable body.

[0017] Optionally, the expandable body is a non-compliant balloon.

[0018] Optionally, the head end component also includes a shell, which covers the expandable device, and the shell and the expandable device are an integrally molded structure or a split-molded structure; when the shell and the expandable device are a split-molded structure, the shell and the expandable device are at least partially fixedly connected in the circumferential direction.

[0019] Optionally, the outer tube assembly includes a sheath tube, and the head end component is arranged at the distal end of the sheath tube and is used to cooperate with the sheath tube;

[0020] When the head end component is expanded, the maximum radial dimension of the head end component is the same as the maximum radial dimension of the sheath tube.

[0021] Optionally, the sheath has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the ratio of the maximum radial dimension of the sheath in the expanded state to the maximum radial dimension of the sheath in the contracted state is not less than 1.05.

[0022] Optionally, the ratio of the maximum radial dimension of the sheath in the expanded state to the maximum radial dimension of the sheath in the contracted state is not higher than 1.3.

[0023] Optionally, the outer tube assembly includes a sheath tube, and the head end component is arranged at the distal end of the sheath tube;

[0024] The sheath has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the maximum radial dimension of the sheath after expansion is the same as the maximum radial dimension of the head end component after expansion, and the maximum radial dimension of the sheath after contraction is smaller than the distal inner diameter of the catheter sheath.

[0025] Optionally, the sheath tube includes a tube body and a connecting structure; the tube body has an opening along the circumferential direction, the opening is continuously arranged along the axial direction, and the opening and closing of the opening corresponds to the state conversion of the sheath tube; the connecting structure is connected to both sides of the opening.

[0026] Optionally, the sheath tube further includes a reinforcement structure, which is continuously arranged in the tube body along at least a portion of the circumference of the tube body, and the reinforcement structure does not overlap in the circumferential direction of the tube body.

[0027] Optionally, the sheath tube has at least one folding area along the circumferential direction when in the contracted state, the folding areas are continuously arranged along the axial direction, and the opening and closing of the folding areas corresponds to the state conversion of the sheath tube.

[0028] Optionally, the delivery system also includes a catheter sheath, and the outer tube assembly includes a sheath tube and a delivery outer tube connected in sequence; when the delivery system is in a delivery state, the catheter sheath is outermost on the delivery outer tube; when the head end component is in an expanded state, the maximum radial dimension of the head end component is greater than the distal inner diameter of the catheter sheath; when the head end component is in a contracted state, the maximum radial dimension of the head end component is smaller than the distal inner diameter of the catheter sheath.

[0029] In the delivery system provided by the present invention, the head end component has at least a contracted state and an expanded state, and is capable of switching between the contracted state and the expanded state; wherein after the head end component contracts, at least part of the radial dimension of the head end component is reduced, and the reduction in radial dimension here is relative to the head end component in the expanded state. With such a configuration, the radial dimension can be adjusted by the retractable head end component, and secondary damage to the blood vessels can be reduced while ensuring the sealing performance and penetration performance of the delivery system, thereby reducing vascular complications. Moreover, when a delivery channel is established with the help of a catheter sheath, the head end component can pass through the catheter sheath after contraction, avoiding the problem of the catheter sheath being withdrawn together with the delivery system and needing to be reinserted, which can further reduce secondary damage to the blood vessels.

[0030] In the delivery system provided by the present invention, the sheath tube has at least a contracted state and an expanded state, and can be converted between the contracted state and the expanded state. Such a configuration increases the deformation performance of the sheath tube, so that the sheath tube has a smaller outer diameter after contraction, which can further reduce secondary damage to the blood vessels. Moreover, when a delivery channel is established with the help of a catheter sheath, the contracted sheath tube is easier to pass through the catheter sheath, further reducing secondary damage to the blood vessels. In particular, the ratio of the maximum radial dimension of the sheath tube in the expanded state to the maximum radial dimension of the sheath tube in the contracted state is not less than 1.05, and more preferably not more than 1.3. Such a configuration can effectively reduce the difficulty of process manufacturing while taking into account better delivery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0032] Figure 1 1 is a schematic structural diagram of a conveying system provided by a preferred embodiment of the present invention, wherein the conveying system shown is a conventional conveying system;

[0033] Figure 2a 1 is a schematic structural diagram of a delivery system for an inline catheter sheath provided in a preferred embodiment of the present invention, wherein the head end component and the sheath are both in an expanded state;

[0034] Figure 2b 1 is a schematic structural diagram of a delivery system for an inline catheter sheath provided by a preferred embodiment of the present invention, wherein the head end component and the sheath are both in a retracted state;

[0035] Figure 3 This is a schematic structural diagram of an inner tube assembly provided in a preferred embodiment of the present invention;

[0036] Figure 4 This is a schematic structural diagram of the head end component in an expanded state provided by the first preferred embodiment of the present invention;

[0037] Figure 5 This is a schematic structural diagram of the head end component in a retracted state provided by the first preferred embodiment of the present invention;

[0038] Figure 6 This is a schematic structural diagram of an inner tube assembly provided in a second preferred embodiment of the present invention;

[0039] Figure 7 This is a schematic structural diagram of the head end component in an expanded state provided by the second preferred embodiment of the present invention;

[0040] Figure 8 This is a schematic structural diagram of the head end component in a retracted state provided by the second preferred embodiment of the present invention;

[0041] Figure 9a 1 is a schematic structural diagram of a sheath tube with foldable wings in a retracted state provided in a third preferred embodiment of the present invention;

[0042] Figure 9b 1 is a schematic structural diagram of a sheath tube with foldable wings in an expanded state provided in a third preferred embodiment of the present invention;

[0043] Figure 9c 1 is a schematic structural diagram of a delivery catheter and a sheath tube with foldable wings provided in a third preferred embodiment of the present invention, wherein the sheath tube is in a retracted state;

[0044] Figure 10a 1 is a schematic structural diagram of a delivery catheter and a sheath tube with a circumferential opening provided in a third preferred embodiment of the present invention, wherein the sheath tube is in a contracted state;

[0045] Figure 10b is a schematic cross-sectional view of a sheath tube with a circumferential opening provided in a third preferred embodiment of the present invention;

[0046] Figure 11a is a cross-sectional view of a sheath tube with a rolled wall folding structure provided in a third preferred embodiment of the present invention, wherein the tube body has an overlapping area along the circumferential direction;

[0047] Figure 11b is a cross-sectional view of a sheath tube with a rolled wall folding structure provided by a third preferred embodiment of the present invention, wherein the tube body does not overlap in the circumferential direction;

[0048] Figure 12 is a three-dimensional diagram of a sheath tube with a built-in reinforcement structure provided in a third preferred embodiment of the present invention, wherein the reinforcement structure includes a metal ring;

[0049] Figure 13a This is an expanded view of the diamond-shaped metal ring provided in the third preferred embodiment of the present invention;

[0050] Figure 13bThis is an expanded view of the oblong metal ring provided in the third preferred embodiment of the present invention;

[0051] Figure 14a is an internal perspective view of a sheath tube provided by a third preferred embodiment of the present invention, wherein the reinforcement structure includes a metal fold line;

[0052] Figure 14b to Figure 14c This is an expanded view of the metal fold line provided in the third preferred embodiment of the present invention;

[0053] Figure 15a This is a schematic structural diagram of a reinforcement structure in a contracted state provided by a third preferred embodiment of the present invention, which is composed of C-shaped metal pieces connected in series in sequence;

[0054] Figure 15b yes Figure 15a Schematic diagram of the structure of the reinforcement structure in the expanded state.

[0055] In the figure: 100-handle; 200-delivery catheter; 201-sheath; 2011-tube body; 2012-connecting structure; 2013-reinforcement structure; 2013A-extension section; 2013B-folded section; 2013C-reinforcement rib; 2014-opening; 2015-outer jacket; 2016-inner lining; 2017-folding wing; 202-delivery outer tube; 203-head end component; 2031-outer shell; 2032-mesh support structure; 2032a-wave rod; 2032b-slider; 2033-expandable body; 2034-inner cavity of expandable body; 204-inner tube; 205-inner core; 300-catheter sheath; 301-catheter section; 302-sheath seat. DETAILED DESCRIPTION

[0056] In order to make the objects, advantages and features of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. As used in this specification, the singular forms "one", "an" and "the" include plural objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in a sense including "and / or", unless the content clearly indicates otherwise. In the description of the present invention, unless otherwise stated, the meaning of "multiple" is generally two or more. In the description of the present invention, unless otherwise stated, the meaning of "not less than" is generally greater than or equal to; the meaning of "not higher than" is generally less than or equal to.

[0057] In the following description, the terms "distal" and "proximal" are used for ease of description; "distal" refers to the side away from the operator of the delivery system, i.e., the end that first enters the body; "proximal" refers to the side closest to the operator of the delivery system; and "axial" refers to the direction along the axis of the delivery system. In addition, in the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features known in the art have not been described to avoid confusion with the present invention.

[0058] The core idea of ​​the present invention is to provide a delivery system suitable for the delivery of medical implants, which includes an outer tube assembly and an inner tube assembly, a portion of the inner tube assembly is arranged in the outer tube assembly, and the inner tube assembly and the outer tube assembly can move relative to each other; wherein the inner tube assembly includes a retractable head end component, and the radial size of the head end component is adjustable through the retraction and expansion of the head end component. It should be understood that the cross-sectional shape of the head end component after expansion or contraction includes but is not limited to a circle; if it is a circle, the radial size of the head end component is the outer diameter; if it is non-circular, the radial size of the head end component refers to the maximum width on the cross section. Similarly, in the following description, the radial size of the sheath can be the outer diameter when the cross section is circular, or the maximum width on the cross section when the cross section is non-circular.

[0059] In the present application, the delivery process of the medical implant generally includes three stages: the first stage is the medical implant loading and delivery stage, in which the head end component is in an expanded state, and the maximum radial dimension of the head end component after expansion is generally the same as the maximum radial dimension of the sheath of the delivery system, and the medical implant is covered by the closure of the sheath and the head end component, so that the medical implant is pressed and limitedly loaded in the sheath; the second stage is the medical implant release stage, in which the medical implant is released by the relative movement of the inner and outer tube components; the third stage is the withdrawal of the delivery system, in which the head end component is in a contracted state, and at least part of the radial dimension of the contracted head end component is reduced. Such a configuration can reduce the secondary damage to the blood vessels caused by the delivery system during the withdrawal stage and reduce vascular complications. Especially when the delivery channel is established with the help of a catheter sheath, the retracted head end component can still pass through the catheter sheath, thereby withdrawing the entire delivery system catheter from the human body, but the catheter sheath remains in the body. Then, when it is necessary to deliver a new product such as a balloon with the help of the original vascular channel, there is no need to reinsert the catheter sheath to establish a passage, thereby avoiding further damage to the blood vessels caused by withdrawing and reinserting the catheter sheath.

[0060] The delivery system disclosed herein can be used to deliver medical implants selected based on the location of the target delivery site. For example, such medical implants include, but are not limited to, heart valve stents. Those skilled in the art will appreciate that, in addition to delivering heart valve stents, the delivery system disclosed herein can also be used to place other medical implants (such as vascular stents, aneurysm stents, balloon-expandable stents, ureteral stents, prostate stents, peripheral stents, and tracheobronchial stents) into corresponding locations in the body. Such medical implants can also be grafts, embolic devices, occlusion devices, and the like. The delivery system disclosed herein can be used with or without a catheter sheath.

[0061] The delivery system disclosed in the present invention can be a conventional delivery system. In this case, the catheter sheath is designed separately from the delivery system, and the delivery system catheter passes through the catheter sheath during both the delivery and withdrawal processes. Of course, the delivery system disclosed in the present invention can also be a delivery system with an inline catheter sheath. In this case, the catheter sheath is pre-placed over the delivery system catheter during both the delivery and withdrawal processes. Whether a conventional delivery system or a delivery system with an inline catheter sheath, the delivery system disclosed in the present invention can reduce secondary damage to blood vessels and reduce vascular complications.

[0062] Specifically, vascular complications are a significant complication of transcatheter implantation. The larger outer diameter of surgical instruments can cause certain vascular damage. Damage to the vessels can occur during both the delivery and withdrawal phases of the implant. The larger outer diameter of the delivery system is particularly prone to secondary damage during withdrawal. The inventors conducted extensive clinical trials and found that controlling the degree of vascular dilation to within 130% (i.e., the dilated vessel diameter is 1.3 times the undilated vessel diameter) during the delivery phase allows the vessel to automatically retract, minimizing the impact on vascular performance. However, this retraction can further damage the vessel when the delivery system re-passes through it. Therefore, a smaller outer diameter of the delivery system during withdrawal can reduce secondary vascular damage. Conventional tip components, however, have a larger outer diameter that is not adjustable and can cause secondary damage during withdrawal. On the contrary, the delivery system disclosed in the present invention can shrink the head end component during the retraction phase, reducing the radial size of the head end component, thereby reducing secondary damage to the blood vessels. Especially in the case of a catheter sheath, the catheter sheath and the delivery system catheter can be prevented from being retracted together, avoiding further damage to the blood vessels caused by the withdrawal and insertion of the catheter sheath.

[0063] Furthermore, the sheath has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the maximum radial dimension of the sheath after expansion is generally the same as the maximum radial dimension of the head end component after expansion, so as to meet the sealing and crossing performance; and at least part of the radial dimension of the sheath after expansion is reduced. Such a configuration can increase the deformation performance of the sheath, so that the sheath has a smaller radial dimension, so as to further reduce secondary damage to the blood vessel. In order to reduce the difficulty of process manufacturing, preferably, the ratio of the maximum radial dimension of the sheath in the expanded state to the maximum radial dimension of the sheath in the contracted state is not less than 1.05, more preferably not more than 1.3. Within this range, it is also possible to take into account the better sheath-loaded implant delivery performance.

[0064] To ensure the sealing and traversability of the delivery system, the maximum radial dimension of the tip component is generally consistent with the maximum radial dimension of the sheath. Furthermore, the ratio of the maximum radial dimension of the tip component in the expanded state to the maximum radial dimension of the tip component in the contracted state is not less than 1.05, and more preferably not more than 1.3.

[0065] The delivery system of the present invention is described in further detail below with reference to the accompanying drawings and preferred embodiments. Furthermore, the following embodiments and features thereof may complement or be combined with each other, unless they conflict. The following description uses a catheter sheath as an example for schematic illustration, but this should not be construed as limiting the present invention. The delivery system of the present invention is not limited to the case of a catheter sheath and may also be used without a catheter sheath.

[0066] Please refer to Figure 1 A preferred embodiment of the present invention provides a delivery system comprising a handle 100 and a delivery catheter 200. The delivery catheter 200 comprises an inner tube assembly and an outer tube assembly that are movable relative to each other, with a portion of the inner tube assembly disposed within the outer tube assembly. The outer tube assembly is axially connected to a sheath tube 201 and a delivery outer tube 202 in sequence from the distal end to the proximal end. The proximal end of the delivery outer tube 202 is connected to the handle 100. The inner tube assembly comprises a head end component 203 disposed at the distal end of the inner tube assembly, the proximal end of which is connected to the handle 100. The head end component 203 is configured to cooperate with the sheath tube 201 (e.g., a closed or interference fit) to enclose and position the medical implant, and the head end component 203 and the sheath tube 201 can be relatively close to or distant from each other.

[0067] In one embodiment, reference Figure 2a and Figure 2b The delivery system can be connected to a catheter sheath 300 (expandable catheter sheath), and the catheter sheath 300 is specifically sleeved on the delivery outer tube 202 to form a delivery system with an inner catheter sheath 300. In another embodiment, referring to Figure 1The delivery system is a conventional delivery system without an inline catheter sheath 300.

[0068] The catheter sheath 300 can utilize existing catheter sheath structures. Generally, the catheter sheath 300 comprises a catheter segment 301 and a sheath hub 302. The proximal end of the catheter segment 301 is connected to the sheath hub 302, while the distal end of the catheter segment 301 is inserted into the opening of a designated blood vessel. Typically, the distal end of the catheter segment 301 has a smaller inner diameter. During delivery, the smaller inner diameter of the distal end of the catheter segment 301 prevents the catheter sheath 300 from moving onto the sheath tube 201, thereby avoiding interference with the prosthesis. The distal end of the catheter segment 301 is a rigid ring, which can be made of a radiopaque material, allowing for positioning using medical imaging during delivery. The distal inner diameter of the catheter sheath 300 refers to the inner diameter of the distal end of the catheter segment 301. The sheath hub 302 is located at the proximal end of the catheter segment 301 and serves as a grip when the catheter segment 301 is introduced into the body. A sealing valve is provided in the sheath hub 302 to minimize blood loss throughout the operation of the catheter sheath 300. The sheath seat 302 is also connected to an emptying tube and a three-way stopcock, which can be used to flush and empty the catheter section 301. The three-way stopcock can be used for drawing blood samples, pressure testing, injecting drugs or contrast agents, etc. during surgery.

[0069] In order to solve the problem that the existing delivery system is prone to causing secondary damage to the blood vessels, and the problem that the catheter sheath 300 and the delivery system are withdrawn together when the delivery system is withdrawn, the present invention improves the structure of the head end component 203, so that when the delivery system is withdrawn, at least part of the radial dimension of the head end component 203 is reduced. This not only reduces the secondary damage to the blood vessels, but also enables the head end component 203 to pass through the catheter sheath 300 to withdraw the entire delivery system catheter from the human body, but retain the catheter sheath 300 in the body, further reducing damage to the blood vessels.

[0070] More specifically, the head component 203 has at least a contracted state and an expanded state, and is capable of transitioning between the contracted and expanded states. When the head component 203 is expanded, i.e., in the expanded state, the head component 203 is generally conical, with a smooth outer surface, and its radial dimensions increase from the distal end to the proximal end, including but not limited to the radial dimensions increasing sequentially from the distal end to the proximal end. When the head component 203 is contracted, i.e., in the contracted state, at least a portion of the radial dimensions of the head component 203 decreases in the contracted state, but the shape of the contracted head component 203 is not limited in any way. In one embodiment, the maximum radial dimension of the contracted head component 203 is smaller than the distal inner diameter of the catheter sheath 300. It should also be understood that the contracted state of the head end component 203 is actually a forced, tightened state, which is the state in which the head end component 203 is subjected to external forces, such as tension or reduced fluid pressure; and the expanded state of the head end component 203 is actually a forced, expanded state, which is the state in which the head end component 203 is subjected to external forces, such as thrust or increased fluid pressure. Furthermore, the contracted state can also be a pre-set state, which is the initial state of the head end component 203 in its natural state. Furthermore, the reduction in at least a portion of the radial dimension of the contracted head end component 203 can be understood as meaning that at least a portion of the radial dimension of the head end component 203 in the contracted state is smaller than the radial dimension of the head end component 203 in the expanded state. Generally, the maximum radial dimension (preferably the maximum outer diameter) of the head end component 203 in the contracted state is smaller than the maximum radial dimension (preferably the maximum outer diameter) of the head end component 203 in the expanded state. That is, after expansion, the head end component 203 can be partially or fully contracted, and conversely, after contraction, the head end component 203 can be partially or fully expanded.

[0071] It should be understood that the telescopic properties of the tip component 203 can, on the one hand, enable the maximum radial dimension of the expanded tip component 203 to be the same as the maximum radial dimension of the sheath 201, thereby meeting the sealing requirements of the delivery system and providing a smooth transition at the distal end of the entire delivery system to meet the requirements of transverse performance. On the other hand, during withdrawal of the delivery system, the maximum radial dimension of the tip component 203 can be reduced, particularly enabling the maximum radial dimension of the contracted tip component 203 to be smaller than the inner diameter of the catheter sheath 300. Thus, in the presence of the catheter sheath 300, the reduced radial dimension of the tip component 203 during withdrawal allows the tip component 203 to pass through the catheter sheath 300, achieving the goal of withdrawing only the delivery system catheter while retaining the catheter sheath 300 within the body. This structure solves the problem of the larger outer diameter of the delivery system in the prior art, which can easily cause secondary damage to the blood vessels, and also solves the problem of withdrawing and reinserting the catheter sheath 300 to establish access in the prior art. This not only reduces the difficulty of surgical operation, but also effectively avoids damage to the blood vessels, reduces vascular complications, and improves the effectiveness of surgical treatment.

[0072] In one embodiment, the head end component 203 includes an expandable device, and the expandable device is capable of expansion and contraction, and the expansion and contraction of the head end component 203 is mainly achieved by the expansion and contraction of the expandable device. The present application does not limit the structure of the expandable device. For example, the expandable device can be a mesh support structure, and the mesh support structure can be cut from a tube or woven from braided wire, or composed of foldable wave rods, or can be an expandable body whose material itself is deformable. The expandable body is made of a medical polymer material and has an inner cavity for injecting a filling medium, so that the expansion and contraction of the expandable device is controlled by the pressure of the filling medium, but the type of the filling medium is not limited, and can be, for example, physiological saline or contrast agent, etc.

[0073] Furthermore, the inner tube assembly further includes an inner core, over which the expandable device is disposed. In an exemplary embodiment, the expandable device is a mesh support structure, at least one end of which is movably disposed relative to the inner core. Furthermore, the proximal end of the mesh support structure is movably disposed relative to the inner core, while the distal end is fixedly connected to the inner core. Furthermore, the proximal end of the mesh support structure is connected to a slider, which is movable relative to the inner core.

[0074] In another exemplary embodiment, the expandable body is a medical balloon. Medical balloons have good expansion and contraction properties and controllable radial dimensions. Preferably, the medical balloon is a non-compliant balloon, primarily made of one or more combinations or composites of polyamide, polyester, polyvinyl chloride, nylon elastomer, and polyurethane elastomer.

[0075] Furthermore, after the head end member 203 is contracted, the radial dimensions of the head end member 203 remain the same. That is, the head end member 203 has a uniform radial dimension after contraction. In this case, the head end member 203 may be cylindrical to obtain a head end member 203 with a smaller radial dimension, thereby improving retraction performance. To facilitate passage of the delivery system through blood vessels, the head end member 203 in the contracted state is generally tapered.

[0076] In one embodiment, the head assembly 203 further includes a housing that encases the expandable device. The entire expandable device is covered by the housing. The housing has a smooth surface and protects the expandable device, minimizing damage to blood vessels caused by the head assembly 203. The housing has a high elongation at break and can expand and contract with the expandable device, thereby increasing or decreasing the radial dimension of the head assembly 203. The housing is typically made of a medical polymer material, such as one or more combinations of polyether block polyamide (PEBAX), polyethylene, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), high-density polyethylene (HDPE), and thermoplastic polyurethane (TPU). Generally, the housing should be made of a material with good elasticity, such as thermoplastic polyurethane or polyether block polyamide. Furthermore, the housing is radiographically displayable, allowing operators to determine the position of the distal end of the delivery system based on the X-ray image of the head assembly 203. Generally, a developer is added to the polymer material used to make the shell. The developer material is not limited and can be, for example, one or more combinations of barium sulfate, tungsten powder, bismuth carbonate, bismuth oxide, and platinum-iridium alloy. In some embodiments, the shell and expandable device are integrally formed, such as when the head end component 203 is a special-shaped balloon. In other embodiments, the shell and expandable device are formed separately and fixedly connected to the expandable device. The method of fixing the shell and expandable device is not limited and can be sutured, tied, or glued. Preferably, the shell and expandable device are at least partially fixedly connected in the circumferential direction.

[0077] In one embodiment, the inner tube assembly has a control channel for an external control component to pass through, and the control component is connected to the expandable device and the handle 100 via the control channel. Medical staff controls the control component through the handle 100, so that the control component drives the expandable device to expand and contract. The control component can be a structure such as a wire, a rope, a belt, a rod, etc. In this example, the control component is a drive wire or a drive rod, which is not specifically limited. In other embodiments, the inner tube assembly has a channel for conveying a filling medium, and the channel is used to inject a filling medium into the expandable device, or to discharge the filling medium in the expandable device. The expandable device is expanded and contracted by changing the pressure of the internal filling medium.

[0078] Furthermore, the inventors of the present application discovered that although existing sheaths are polymer tubes with a certain degree of deformation, the actual deformation is not large, and there is a risk that the sheath will not easily pass through the catheter sheath 300 when the delivery system is withdrawn. To reduce this risk, the present invention also improves the structure of the sheath, increasing its deformation performance, so that the sheath 201 has a smaller radial dimension after contraction, further reducing secondary damage to the blood vessels. It also allows the sheath 201 to pass through the catheter sheath 300 more smoothly, further reducing damage to the blood vessels. Specifically, the sheath 201 has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the maximum radial dimension of the sheath 201 after expansion is the same as the maximum radial dimension of the head end component 203 after expansion; and the maximum radial dimension of the sheath 201 after contraction is smaller than the distal inner diameter of the catheter sheath 300; with such a configuration, when withdrawing the delivery system, not only does it make the sheath 201 have a smaller outer diameter, but it can also reduce the difficulty of the sheath 201 passing through the catheter sheath 300, so that the entire delivery system can be evacuated from the human body more smoothly and reduce damage to blood vessels.

[0079] Next, the structure of the head end component 203 will be further described in detail in conjunction with several preferred embodiments. However, the following examples are only for illustration and do not constitute any limitation to the present invention.

[0080] <Example 1>

[0081] Please refer to Figures 3 to 5 In this embodiment, the head end component 203 is disposed at the distal end of the inner tube assembly and includes a smooth outer shell 2031. When expanded, the outer shell 2031 assumes a conical shape. The head end component 203 also includes an expandable device, which is a mesh support structure 2032 disposed within the outer shell 2031. When the outer shell 2031 is expanded, the radial dimensions and axial length of the mesh support structure 2032 are adapted to those of the outer shell 2031. The outer shell 2031 contracts as the mesh support structure 2032 contracts and expands as the mesh support structure 2032 expands.

[0082] In this embodiment, the inner tube assembly includes an inner tube 204 and an inner core 205, wherein the inner core 205 is at least partially disposed within the inner tube 204. In a specific embodiment, the inner core 205 extends beyond the distal end of the inner tube 204, and the inner core 205 and the inner tube 204 remain relatively stationary. A guidewire can pass through the interior of the inner core 205.

[0083] In this example, the mesh support structure 2032 is composed of a plurality of foldable wave rods 2032a, which are spaced apart along the circumference. The proximal ends of at least some of the wave rods 2032a are connected to the distal end of the inner tube 204, and the distal ends of the wave rods 2032a are connected to the distal end of the inner core 205. In another example, the proximal ends of all the wave rods 2032a are connected to the distal end of the inner tube 204, and the distal ends of at least some of the wave rods 2032a are connected to the distal end of the inner core 205. Therefore, the mesh support structure 2032 can be contracted and expanded by manipulating the folding and stretching of at least some of the wave rods 2032a.

[0084] In one embodiment, the distal ends of all the wave rods 2032a are fixedly connected to the distal end of the inner core 205, while the proximal ends of some of the wave rods 2032a are fixedly connected to the distal end of the inner tube 204. The proximal ends of other wave rods 2032a are connected to a control component. This allows the wave rods 2032a connected to the control component to fold and extend, and achieve non-uniform retraction, under the control of the control component. In another embodiment, the distal ends of all the wave rods 2032a are fixedly connected to the distal end of the inner core 205, while the proximal ends of all the wave rods 2032a are connected to the control component. This allows the wave rods 2032a to fold and extend, and achieve uniform retraction, under the control of the control component. Furthermore, the control component may be directly or indirectly connected to the wave rods 2032a. Furthermore, the distal end of the control component is connected to the proximal ends of at least some of the wave rods 2032a, and the proximal end of the control component is configured to pass through the gap between the inner tube 204 and the inner core 205 and then connect to the handle 100.

[0085] In one example, the distal end of the mesh support structure 2032 is fixed to the distal end of the inner core 205, and the proximal end of the mesh support structure 2032 is movably disposed at the distal end of the inner tube 204. By moving the proximal end of the mesh support structure 2032 back and forth relative to the distal end, the maximum radial dimension of the mesh support structure 2032 is increased or decreased, thereby achieving variable radial dimensions of the head end component 203. In another example, the proximal end of the mesh support structure 2032 is fixed to the distal end of the inner tube 204, and the distal end of the mesh support structure 2032 is movably disposed at the distal end of the inner core 205. By moving the distal end of the mesh support structure 2032 back and forth relative to the proximal end, the maximum radial dimension of the mesh support structure 2032 is increased or decreased, thereby achieving variable radial dimensions of the head end component 203. In other examples, the proximal end of the mesh support structure 2032 is movably disposed at the distal end of the inner tube 204, and the distal end of the mesh support structure 2032 is movably disposed at the distal end of the inner core 205. In this case, the maximum radial dimension of the mesh support structure 2032 is increased or decreased by relative movement of the proximal and distal ends of the mesh support structure 2032, thereby achieving variable radial dimensions of the head end component 203.

[0086] Figure 4 FIG. 2 is a diagram showing the expanded state of the mesh support structure 2032. Figure 4 As shown in a specific example, the proximal ends of all the wave rods 2032a are fixed on a slider 2032b, and the distal ends of all the wave rods 2032a are fixedly connected to the distal end of the inner core 205. The proximal end of the mesh support structure 2032 moves relative to the distal end through the forward and backward movement of the slider 2032b. Figure 4 As shown, as the proximal end of the mesh support structure 2032 moves toward the distal end, the radial dimension of the mesh support structure 2032 increases until the maximum radial dimension of the head end component 203 matches the maximum radial dimension of the sheath tube 201. It is sufficient to maintain the expanded state of the head end component 203. The slider 2032b can be a sleeve structure having a plurality of mounting holes spaced circumferentially thereon, and the proximal end of each wave rod 2032a is fixedly connected to a corresponding mounting hole.

[0087] Figure 5 FIG. 2 is a diagram showing the contraction state of the mesh support structure 2032. Figure 5 As shown, when the proximal end of the mesh support structure 2032 moves away from the distal end, the radial dimension of the mesh support structure 2032 decreases until the maximum radial dimension of the head end component 203 is smaller than the inner diameter of the catheter sheath 300. Preferably, the wave rod 2032a can be extended into a straight state to minimize the radial dimension of the head end component 203.

[0088] In order to better control the radial dimension change of the mesh support structure 2032, the delivery system preferably further includes the control component, which can be directly or indirectly connected to the wave rod 2032a to drive the wave rod 2032a to extend and retract.

[0089] In one embodiment, the control component includes at least one driving wire, one end of the at least one driving wire is connected to the slider 2032b (see Figure 4 and Figure 5 ), the other end passes through the delivery system catheter and is connected to the handle 100, so that the slider 2032b is pushed and pulled by at least one driving wire. Figure 3 As shown, at least one drive wire can be inserted into the gap between the inner core 205 and the inner tube 204. In another embodiment, the control component includes at least one drive rod, one end of which is connected to the slider 2032b, and the other end of which passes through the delivery system catheter and is connected to the handle 100, so that the drive rod pushes and pulls the slider 2032b to move. However, in other embodiments, the slider 2032b can be eliminated, and the rod 2032a can be directly connected to the control component, such as directly connected to at least one drive wire or directly connected to the drive rod.

[0090] Furthermore, a control component such as a control button may be provided on the handle 100 , and the movement (such as movement or rotation) of the control component drives the operation component to move.

[0091] As a preferred embodiment, the proximal ends of all the wave rods 2032a of the mesh support structure 2032 are connected to at least one driving wire, at least one of the driving wires is passed between the inner core 205 and the inner tube 204, and the distal ends of all the wave rods 2032a are fixed to the farthest end of the inner core 205. The control button on the manual operation handle 100 drives at least one driving wire to move, and finally drives the mesh support structure 2032 to fold and stretch.

[0092] As another preferred embodiment, the proximal ends of all the wave rods 2032a of the mesh support structure 2032 are connected to a driving rod. One of the driving rods can be externally mounted on the inner tube 204, and the distal ends of all the wave rods 2032a are fixed to the farthest end of the inner core 205. The control button on the manual operation handle 100 drives a driving rod to move, and finally drives the mesh support structure 2032 to fold and stretch.

[0093] Furthermore, the head end component 203 can be provided separately and detachable from the conduit of the inner tube assembly, or can be integrated with the conduit of the inner tube assembly so that the head end component 203 and the conduit are inseparable. If the head end component 203 is provided as a separate component, the head end component 203 can include an independent inner core, which is assembled and connected to the inner tube 204 and the inner core 205, so that the head end component 203 can be provided independently and can be easily replaced at any time.

[0094] This embodiment does not limit the material of the outer shell 2031. The outer shell 2031 is typically made of a highly elastic polymer material to cover the entire mesh support structure 2032. Its ends are fixedly connected to the mesh support structure 2032, such as by sewing, tying, or gluing, forming the outer surface of the head end component 203. The outer shell 2031 is made of an elastomer, such as TPU (thermoplastic polyurethane) or a polyether polyester block copolymer, such as Pebax (polyether block polyamide). These materials exhibit high elongation at break, allowing them to radially stretch when the mesh support structure 2032 expands and recover when it contracts. This allows the outer shell 2031 to expand and contract with the mesh support structure 2032. Preferably, the outer shell 2031 is partially fixedly connected to the mesh support structure 2032 circumferentially. The connection method is not limited and can be prepared using conventional processes, such as gluing, sewing, or tying.

[0095] The present embodiment also has no limitations on the material of the mesh support structure 2032. For example, medical polymer materials or medical metal materials may be used. Medical metal materials include, but are not limited to, metal elastic materials. Preferably, the mesh support structure 2032 is made of one or more combinations of nickel-titanium alloy, nitinol, stainless steel, cobalt-chromium alloy, and nickel-cobalt alloy. In other embodiments, the mesh support structure 2032 is made of a medical polymer material, such as polylactic acid.

[0096] In this embodiment, a control channel may be provided between the inner tube 204 and the inner core 205 , and the control channel is used for allowing control components to pass through.

[0097] It should be understood that this embodiment utilizes the contraction or expansion of the mesh support structure 2032 to achieve adjustable radial dimensions of the head end component 203. It has a simple structure, is easy to manufacture, and is easy to operate. Moreover, the radial dimensions of the head end component 203 are controllable, which can ensure the safety of the operation.

[0098] <Example 2>

[0099] The structure of the head end component provided in this embodiment is substantially the same as that of the head end component in the first embodiment. The similarities will not be described in detail and please refer to the first embodiment above. The following mainly describes the differences.

[0100] refer to Figures 6 to 8 In this embodiment, the expandable device is an expandable body 2033. The expandable body 2033 is made of a medical polymer material and has a certain degree of elasticity. It can expand when filled with a filling medium and contract when the filling medium is drained or reduced. The expandable body 2033 can be a medical balloon or other pre-plastic expandable body.

[0101] Specifically, the expandable body 2033 has at least two states, namely a contracted state and an expanded state, and switches between the contracted state and the expanded state; the contracted state of the expandable body 2033 is actually a predetermined state, and the expanded state of the expandable body 2033 is actually a forced expansion state, wherein the predetermined state is the initial state of the expandable body 2033 in the natural state; the expanded state is the state of the expandable body 2033 when it is expanded after being filled.

[0102] Figure 7 FIG is a cross-sectional view of the head end component 203 in the expanded state. Figure 7 As shown, after the inner cavity 2034 of the expandable body 2033 is filled with the filling medium, the expandable body 2033 expands, increasing the radial size of the head end component 203 until the maximum radial size of the head end component 203 matches the maximum radial size of the sheath 201, and then maintaining the filling pressure of the expandable body 2033.

[0103] Figure 8 FIG is a cross-sectional view of the head end component 203 in the retracted state. Figure 8 As shown, after the inner cavity 2034 of the expandable body 2033 leaks, the expandable body 2033 shrinks, reducing the radial size of the head end component 203, and further making the maximum radial size of the head end component 203 smaller than the distal inner diameter of the catheter sheath 300.

[0104] This embodiment does not limit the medical polymer material for preparing the expandable body 2033. It can adopt conventional medical polymer materials, such as one or more combination mixtures or composites of polyamide, polyester, polyvinyl chloride, nylon elastomer and polyurethane elastomer.

[0105] Furthermore, the expandable body 2033 is covered with a shell (not shown) to increase the strength of the expandable body 2033. Due to its high elongation at break, the shell can be stretched when the expandable body 2033 is inflated and expanded, and can be restored when the expandable body 2033 is depressurized or retracted. Therefore, the shell can adapt to the expansion and contraction of the expandable body 2033.

[0106] In this embodiment, if Figures 6 to 8 As shown, the shell and the expandable body 2033 are an integrally formed structure, such as a predetermined special-shaped balloon, and the special-shaped balloon in the expanded state forms an integral head end component 203. Preferably, the special-shaped balloon is a non-compliant balloon, and the outer wall of the balloon is generally conical.

[0107] In other embodiments, the housing and the expandable body 2033 are separately formed structures, and both ends of the housing are fixedly connected to the expandable body 2033, such as by adhesion, to form the outer surface of the head end component 203. Preferably, the housing and the expandable body 2033 are partially fixedly connected in the circumferential direction, and the connection method is not limited, and conventional manufacturing processes such as adhesion can be selected.

[0108] It should be noted that when a single balloon is filled with a filling fluid (e.g., filling liquid) at a nominal pressure (i.e., rated pressure), it expands to a certain size. Typically, the balloon's cross-section is roughly circular at this point, and its diameter (outer diameter) is the nominal diameter. Continued injection of filling fluid into a balloon at its nominal diameter causes further expansion, eventually causing it to burst. The internal pressure at the time of bursting is the rated burst pressure. In this embodiment, a non-compliant balloon is one whose diameter at the rated burst pressure is no greater than 15% of the nominal diameter. The head component 203 is a non-compliant balloon that is intended to come into direct contact with human tissue during use. It must possess a high puncture resistance and a certain degree of compressive strength to prevent puncture by certain tissues, such as calcified annuli.

[0109] In this embodiment, the expandable body 2033 is fixed to the inner core 205, with its proximal end fixedly connected to the distal end of the inner tube 204, and its distal end fixedly connected to the distal end of the inner core 205. A channel (not shown) for delivering a filling medium is provided between the inner core 205 and the expandable body 2033. The proximal end of the channel is connected to the handle 100, and the distal end is provided with at least one outlet, which is connected to the inner cavity 2034 of the expandable body 2033. Thus, the filling medium can be delivered to or discharged from the expandable body 2033 through the channel.

[0110] It can be understood that this embodiment utilizes the contraction or expansion of the expandable body 2033 to achieve the adjustable radial size of the head end component 203. This structure is simple, easy to manufacture, easy to operate, and convenient for adjusting and controlling the radial size of the head end component 203.

[0111] Next, the sheath tube 201 is further described in detail herein with reference to specific embodiments. However, the following embodiments do not constitute a limitation on the sheath tube 201 of the present invention.

[0112] <Example 3>

[0113] When the delivery system delivers a medical implant, first, during the medical implant loading and delivery stage, the radial dimension of the sheath tube 201 after expansion is adapted to the medical implant in the gripped state, and the radial dimension of the sheath tube 201 after expansion is larger than the radial dimension of the delivery outer tube 202, thereby gripping the medical implant between the sheath tube 201 and the inner tube 204, and the maximum radial dimension of the sheath tube 201 after expansion is adapted to the maximum radial dimension of the head end component 203 after expansion; secondly, during the delivery system withdrawal stage, the radial dimension of the head end component 203 and the radial dimension of the sheath tube 201 can both be reduced, especially so that the delivery system catheter can more smoothly pass through the catheter sheath 300 and withdraw the entire delivery system catheter, while the catheter sheath 300 remains in the body.

[0114] For example, Figure 2a In the illustrated sheath delivery system with an inline catheter sheath, the head end component 203 and the sheath tube 201 are both in an expanded state. The maximum radial size of the head end component 203 and the sheath tube 201 after expansion is larger than the distal inner diameter of the catheter sheath 300, and it is not easy to retract to the catheter sheath 300.

[0115] For example, Figure 2b In the illustrated sheath delivery system with an inline catheter sheath, the head end component 203 and the sheath tube 201 are both in a retracted state. The maximum radial dimension of the head end component 203 and the sheath tube 201 after retraction is smaller than the distal inner diameter of the catheter sheath 300, so that the catheter sheath 300 can be passed smoothly.

[0116] The following is a further detailed description of the method for achieving variable diameter of the sheath tube 201 in conjunction with specific embodiments. However, the following embodiments do not constitute a limitation on the sheath tube 201 of the present invention.

[0117] Please refer to Figures 9a to 9c In an exemplary embodiment, the sheath 201 is a polymer tube with folding wings 2017, and its material can be conventional medical polymer tubes such as the Pebax series. The sheath 201 is closed circumferentially and has at least one folding wing 2017 along the circumference when in the contracted state, but the number of folding wings 2017 is not limited to one, and can also be multiple. The folding wings 2017 are continuously arranged along the axial direction, and the opening and closing of the folding wings 2017 corresponds to the state conversion of the sheath 201. Therefore, the presence of the folding wings 201 allows the sheath 201 to expand radially outward, and the sheath 201 can restore the folded state by itself when retracted to reduce the radial size of the sheath 201. In detail, after the sheath 201 covers the medical implant (such as a heart valve stent), the sheath 201 is stretched, and the sheath 201 is expanded to the extent that it can cover the medical implant according to the size of the medical implant, for example Figure 9b The diagram shows the state of the sheath tube 201 being fully expanded. At this time, the sheath tube 201 is expanded to its maximum size after the medical implant is inserted. Figure 9a and Figure 9c When the delivery system is withdrawn, the sheath 201 automatically returns to its initial folded shape, reducing the radial dimension of the sheath 201 so that it can pass smoothly through the catheter sheath 300. The advantage of providing the folding wings 217 is that it reduces the radial dimension of the sheath 201 in the pre-formed state, which is conducive to reducing the delivery size.

[0118] Please refer to Figure 10a and Figure 10bIn another exemplary embodiment, the sheath tube 201 includes a tube body 2011 and a connecting structure 2012. The tube body 2011 has circumferential openings 2014, which are continuously arranged along the axial direction. The openings 2014 open and close corresponding to the state transition of the sheath tube 201. The connecting structure 2012 is connected to two radially opposite sides of the openings 2014 of the tube body 2011, connecting the two radially opposite sides of the openings 2014. It should be understood that the openings 2014 extend axially along the tube body 2011. The tube body 2011 is configured to have a certain degree of elasticity. When the tube body 2011 is subjected to a radially outward expansion force, the presence of the openings 2014 allows the tube body 2011 to expand radially outward. The connecting structure 2012 is connected to two radially opposite sides of the openings 2014, ensuring that the outer circumference of the sheath tube 2011 is sealed. Preferably, the sheath tube 201 further includes a reinforcement structure 2013, which is continuously disposed within the tube body 2011 along at least a portion of the circumference of the tube body 2011, and the reinforcement structure 2013 does not overlap in the circumferential direction of the tube body 2011. It should be understood that the reinforcement structure 2013 is disposed within the tube body 2011. In one example, the reinforcement structure 2013 is attached to the inner wall of the tube body 2011, or the inner wall of the tube body 2011 is provided with a recessed area that matches the thickness of the reinforcement structure 2013, and the reinforcement structure 2013 is disposed in the recessed area; in another example, the reinforcement structure 2013 is embedded in the side wall of the tube body 2011, that is, the reinforcement structure 2013 is buried in the side wall of the tube body 2011. The setting of the reinforcement structure 2013 can achieve radial reinforcement of the tube body 2011, effectively enhance the bending and compression resistance of the sheath 201 without affecting the expansion performance of the sheath 201, achieve compliant bending in all directions, reduce the risk of bending the sheath 201 due to excessive curvature of the blood vessel, and improve surgical safety.

[0119] Preferably, the sheath tube 201 further comprises an outer cover 2015 and / or an inner liner 2016; the outer cover 2015 covers the outer surface of the tube body 2011 and can adapt to the expansion and contraction of the sheath tube 201 by elastic expansion and contraction; the inner liner 2016 is attached to the inner surface of the tube body 2011 and the reinforcing structure 2013. Figure 10b In one embodiment, the sheath tube 201 is divided into four layers from the outside to the inside, namely, an outer shell 2015, a tube body 2011, a reinforcement structure 2013, and an inner liner 2016. It should be understood that in some embodiments, both the outer shell 2015 and the inner liner 2016 may be provided, while in other embodiments, only one of the outer shell 2015 and the inner liner 2016 may be provided.

[0120] The outer sleeve 2015 is made of a material with a higher elasticity than the tube body 2011, covering the entire circumference. Its ends are bonded to the wall of the tube body 2011, forming the outer surface of the sheath tube 201. The outer sleeve 2015 can be made of materials such as TPU (thermoplastic polyurethane) or Pebax (polyether block polyamide), which have high elongation at break. This allows the outer sleeve 2015 to radially stretch when the tube body 2011 expands and recover when the tube body 2011 contracts. In other words, the outer sleeve 2015 can expand and contract with the expansion and contraction of the tube body 2011. Preferably, the outer sleeve 2015 is partially fixedly connected to the tube body 2011 along the circumference. The connection method is not limited and can be prepared using conventional processes such as bonding.

[0121] The liner 2016 provides a smooth inner wall, forming the inner surface of the sheath tube 201. In some embodiments, the reinforcement structure 2013 is attached to the inner wall of the tube body 2011. In areas of the tube body 2011 where the reinforcement structure 2013 is not provided, the liner 2016 is attached to the inner wall of the tube body 2011. In areas where the reinforcement structure 2013 is provided, the liner 2016 is attached to the inner wall of the reinforcement structure 2013. Optionally, the liner 2016 can also be attached to the inner sidewall of the connecting structure 2012 to cover the inner surface of the sheath tube 201, thereby achieving a circumferentially closed arrangement of the liner 2016 on the inner surface of the sheath tube 201. Preferably, the liner 2016 is made of a high-strength, low-friction material, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), or HDPE (high-density polyethylene), to further reduce the friction coefficient of the inner wall and facilitate the insertion and release of the medical implant. In particular, in some embodiments, the connection structure 2012 may be formed by extending the liner 2016, i.e., the material and structure of the connection structure 2012 are the same as those of the liner 2016. Optionally, the liner 2016 is fixedly connected to the inner wall of the pipe body 2011 or the inner wall of the reinforcement structure 2013. The connection method is not limited and conventional preparation processes such as bonding can be selected.

[0122] Please refer to Figure 11a and Figure 11bIn one exemplary embodiment, the tube body 2011 includes a polymer tubing layer with a rolled-wall folded structure. The material used can be conventional medical polymer tubing, such as the Pebax series. The polymer tubing layer is not circumferentially closed. Preferably, when the sheath tube 201 is in a contracted state, the tube body 201 has an overlapping region along the circumference. The opening 2014 is located in the overlapping region, and the connecting structure 2012 is sandwiched within the overlapping region. The overlapping region can be partially or fully expanded within a patient's blood vessel, with the degree of expansion being determined by the size of the medical implant being passed through. The advantages of providing the overlapping region are: on the one hand, it reduces the diameter of the sheath tube 201 in its pre-formed state; on the other hand, in the expanded state, the overlapping region serves as part of the sheath tube 201, further improving the bending resistance of the expanded sheath tube 201. In some other embodiments, the two axial edges of the polymer tube layer gradually become thinner toward the edges (both sides of the opening 2014), which has the advantage of reducing the thickness of the overlapping area and making a smooth transition at the opening 2014, which is beneficial for the expansion of the connection structure 2012 and is more conducive to forming an expanded state. Figure 11b In other embodiments, the tube body 2011 does not overlap circumferentially when the sheath tube 201 is in the contracted state, and the connecting structure 2012 overlaps and covers the opening 2014, forming a pleat-like shape. The tube body 2011 does not overlap circumferentially, i.e., there is no overlap, while the opening 2014 is directly covered by the connecting structure 2012. The connecting structure 2012 is preferably made of an elastic material to accommodate the expansion requirements of the sheath tube 201. Preferably, the connecting structure 2012 is made of a highly elastic and high-strength material, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), or HDPE (high-density polyethylene). In other embodiments, other materials with similar properties known to those skilled in the art may also be used. More preferably, the connecting structure 2012 is configured to be flattened but not stretched, allowing it to better return to its original state after expansion, thereby preventing plastic deformation.

[0123] Preferably, the extension length of the reinforcement structure 2013 along the circumferential direction of the tube body 2011 is not less than 3 / 4 of the inner circumference of the sheath tube 201 when it is in the contracted state. Figure 10b The inner circumference of the sheath tube 201 in the contracted state means that if the tube body 2011 has a circumferential overlap area, the inner circumference does not include the body section overlapped by the overlap area, but only covers the tube body 2011 with a circumferential angle of 360°. Figure 10bIn the illustrated tube body 2011, the tube body 2011 extends counterclockwise around the inner wall of the tube body, starting from the inner opening of the tube body 2011 in the overlapped area, to the position corresponding to the inner opening of the tube body and the overlapped area, without continuing to extend into the overlapped area. The extension length of the reinforcement structure 2013 is not less than 3 / 4 of the inner circumference. It is understood that one or both ends of the reinforcement structure 2013 can extend into the overlapped area. Depending on the length of the overlapped area, both ends of the reinforcement structure 2013 can also be located outside the overlapped area. If the tube body 2011 does not overlap circumferentially, as shown in FIG. Figure 11b As shown, the inner circumference of the sheath 201 when it is in the contracted state refers to the circumference of the entire inner wall of the tube body. It should be understood that in some special cases, such as when the sheath 201 is in the contracted state, the tube body 2011 is not circumferentially closed at the opening 2014, then the circumferential coverage angle of the inner circumference is less than 360°, that is, it only matches the inner wall of the tube body 2011.

[0124] The reinforcing structure 2013 preferably includes a metal layer, which has good elasticity. The ratio of the extended length of the reinforcing structure 2013 to the inner circumference is between 3 / 4 and 1, so that the reinforcing structure 2013 is C-shaped in the circumferential direction, which increases the overall stiffness of the sheath 201 and helps the sheath 201 to recover to the contracted state, that is, to the original open state, after the external force is removed.

[0125] like Figure 12 As shown, in an exemplary embodiment, the reinforcement structure 2013 includes a metal ring, and the length of the metal ring along the circumferential direction of the tube body 2011 is greater than the length along the axial direction of the tube body 2011, that is, when a single metal ring is unfolded, it is a circumferential rectangle with the long side perpendicular to the axis of the tube body 2011. In the present invention, it is not limited to a rectangle with the long side perpendicular to the axis of the tube body, and can also be a rectangle, square or ellipse with the long side parallel to the axis of the tube body. Preferably, the reinforcement structure 2013 includes a plurality of metal rings, and the plurality of metal rings are arranged along the axial direction of the tube body 2011. The arrangement of the metal rings provides a highly flexible anti-bending range, realizing the compliant bending of the sheath tube 201 in all directions.

[0126] This application has no requirements on the shape of the metal ring, it can be Figure 13a The diamond-shaped metal ring in the Figure 13bThe oblong metal rings in the embodiment are, however, understandably, those skilled in the art may also configure the metal rings to other shapes, such as rings, quadrilaterals, or ellipses. Preferably, multiple metal rings are arranged in an intermittent manner. Each metal ring can be the same or different in size, shape, and spacing between metal rings can be the same or different. The design of independently spaced metal rings allows for more uniform circumferential force distribution and improved shape recovery during expansion of the sheath tube 201. The spacing between axially adjacent metal rings can also vary to achieve different bending resistance properties. A denser distribution can also effectively achieve axial compressive resistance. Those skilled in the art can set the spacing between metal rings based on practical needs. Multiple metal rings can be arranged parallel to each other, or they are not limited to being parallel to each other. Adjacent metal rings can also be arranged at angles, such as in groups of two in an "eight" shape, in groups of three in a "river" shape, or in groups of more in a repeated arrangement. The metal rings can also be arranged at irregular angles. The metal rings arranged at an angle can provide a certain supporting force in the axial direction when the sheath tube 201 is expanded, thereby improving its anti-bending performance.

[0127] In other embodiments, multiple metal rings are arranged at intervals, with their lengths along the circumferential direction of the tube body gradually decreasing from the proximal end to the distal end along the axial direction of the tube body. Metal rings at the proximal end have a longer circumferential length along the tube body and are relatively close to the outer delivery tube 202, while metal rings at the distal end have a shorter circumferential length along the tube body and are relatively far from the outer delivery tube 202. With this arrangement, the sheath tube 201 can be expanded to varying degrees based on the different expansion requirements at the distal and proximal ends. During the initial expansion phase, the sheath tube 201 is subjected to less radial expansion force, and the longer metal rings can better maintain minimal deformation, improving stability during expansion and facilitating operation. In other examples, the spacing between metal rings gradually increases along the axial direction of the tube body from the proximal end to the distal end. That is, the metal rings are densely distributed near the outer delivery tube 202, while the metal rings are sparsely distributed far from the outer delivery tube 202. This arrangement also allows the sheath tube 201 to be expanded to varying degrees based on the different expansion requirements at the distal and proximal ends.

[0128] In another example, multiple metal rings are arranged adjacent to each other, each of which is the same size and shape, and are arranged parallel to each other. Adjacent metal rings are connected to each other, forming a pattern similar to a woven mesh. The advantage of this arrangement is that the continuous metal rings provide better compression resistance and enhance the torque control. Compared with the design of spaced metal rings, the metal rings arranged adjacent to each other in sequence provide a stronger support, effectively improving the compression resistance of the sheath tube 201 and enhancing the torque control performance of the sheath tube 201. Of course, in other examples, those skilled in the art can also configure the multiple metal rings to be arranged in an overlapping manner, that is, the metal rings have overlapping portions to form a grid, which can further improve the support performance of the metal rings.

[0129] like Figure 14a As shown, in an exemplary embodiment, the reinforcement structure 2013 includes a metal fold line, and the extension length of the metal fold line along the circumferential direction of the tube body 2011 is greater than the fold length along the axial direction of the tube body 2011. The provision of the metal fold line can further improve the bending resistance of the sheath 201, and the fold structure can achieve better compression resistance. Preferably, the metal fold line can be woven from a single metal wire, or it can be formed by connecting the metal fold line by bonding, welding, etc. after being manufactured separately. The metal fold line can be woven in a U-shaped, V-shaped, S-shaped, Z-shaped or bow-shaped design. Please refer to Figure 14b Generally, the metal fold line includes an extension section 2013A and a fold section 2013B. The extension section 2013A extends circumferentially of the tube body 2011, while the fold section 2013B extends axially of the tube body 2011. The metal fold line connects the circumferential extension sections 2013A via the fold section 2013B, thereby improving the axial compressive strength and bending resistance of the sheath tube 201, ensuring that the overall shape of the sheath tube 201 remains stable while it is expanded.

[0130] Please refer to Figure 14cIn a specific embodiment, the reinforcement structure 2013 may further include a reinforcing rib 2013C arranged axially along the tube body 2011, with the rib 2013C sequentially extending through multiple metal rings or metal fold lines. Optionally, there may be at least one reinforcing rib 2013C. Preferably, the reinforcing rib 2013C is located at the center of the metal ring or metal fold line along the circumferential direction of the tube body 2011. Optionally, the reinforcement structure 2013 includes multiple metal rings arranged at equal intervals. Preferably, the reinforcing rib 2013C is located within the inner layer of the metal rings, at the central axis of the metal ring structure. This arrangement effectively enhances the sheath tube 201's axial compressive and torsional deformation resistance. The reinforcing rib 2013C effectively absorbs the axial pressure of the sheath tube 201, allowing the metal rings to fully perform radial expansion and recovery functions. Furthermore, the sheath tube 201 with the reinforcing rib 2013C significantly improves its overall bending resistance. It should be noted that those skilled in the art may adjust the number of reinforcing ribs 2013C based on actual needs, or may add reinforcing ribs 2013C to the metal fold lines, which also achieves good results. Preferably, the metal ring, metal fold lines, or reinforcing ribs 2013C may be made of a memory alloy to enhance the pre-setting capability and post-expansion recovery capability of the reinforcing structure 2013.

[0131] Please refer to Figure 15a and Figure 15b In another exemplary embodiment, the reinforcement structure 2013 may be a skeleton structure composed of a plurality of C-shaped metal pieces connected in series, which can effectively enhance the axial compression and torsional deformation resistance of the sheath tube 201. The number of C-shaped metal pieces is determined according to the axial length of the sheath tube 201. Figure 15a It shows that the reinforcement structure 2013 is in a contracted state. Figure 15b The reinforcement structure 2013 is shown in an expanded state.

[0132] In summary, the delivery system of the present invention realizes the adjustable radial size of the head end component through the retractable head end component. On the basis of ensuring the sealing performance and penetration performance of the delivery system, the head end component has a smaller radial size after contraction, so as to reduce secondary damage to the blood vessels. Moreover, when the delivery channel is established with the help of the catheter sheath, the contracted head end component can also pass through the catheter sheath, avoiding the problem of the catheter sheath and the delivery system being withdrawn together, further reducing damage to the blood vessels, improving the safety of the operation, and reducing vascular complications. In addition, the present invention enhances the deformation performance of the sheath tube through the structural design of the sheath tube, so that the sheath tube has a smaller radial size after contraction, thereby further reducing secondary damage to the blood vessels. Then, when the delivery channel is established with the help of the catheter sheath, the contracted sheath tube can also pass through the catheter sheath more easily, further solving the problem of the catheter sheath and the delivery system being withdrawn together.

[0133] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between the various embodiments can be referred to in conjunction with each other. The above description is merely a description of preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes or modifications made by a person skilled in the art based on the above disclosure are within the scope of protection of the present invention.

Claims

1. A conveying system, characterized in that: The invention comprises an outer tube assembly and an inner tube assembly, wherein a portion of the inner tube assembly is disposed inside the outer tube assembly, and the inner tube assembly and the outer tube assembly are capable of relative movement; The inner tube assembly includes a head end component, the head end component has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; after the head end component is contracted, at least a portion of the radial dimension of the head end component is reduced; The ratio of the maximum radial dimension of the head end component in the expanded state to the maximum radial dimension of the head end component in the contracted state is not less than 1.05 and not more than 1.

3.

2. The conveying system according to claim 1, characterized in that The inner tube assembly further comprises an inner core, and the head end component is outer-mounted on the inner core.

3. The conveying system according to claim 2, characterized in that The head end component includes an expandable device, the expandable device is capable of expansion and contraction, and the head end component is capable of expansion and contraction along with the expandable device.

4. The conveying system according to claim 3, characterized in that The expandable device is a mesh support structure, at least one end of which is movably arranged relative to the inner core; the mesh support structure is woven from braided wire or cut from a tube, or the mesh support structure is composed of a plurality of foldable wave rods, which are arranged at intervals along the circumference.

5. The conveying system according to claim 3, characterized in that The inner tube assembly also includes an inner tube, the inner core is at least partially placed in the inner tube, the expandable device is composed of a plurality of foldable wave rods, the plurality of wave rods are arranged at intervals along the circumferential direction, and the proximal ends of at least part of the wave rods are connected to the distal end of the inner tube, and the distal ends of the wave rods are connected to the distal end of the inner core.

6. The conveying system according to claim 5, characterized in that The delivery system further includes a manipulation component, wherein at least a proximal end of a portion of the wave rod is connected to a distal end of the manipulation component, and the manipulation component is used to control the folding and extension of the wave rod.

7. The conveying system according to claim 3, characterized in that The expandable device is an expandable body made of polymer material, the expandable body has an inner cavity for injecting filling medium, and the expandable body is fixed on the inner core; a channel for conveying filling medium is provided between the inner core and the expandable body.

8. The conveying system according to claim 7, characterized in that The expandable body is a non-compliant balloon.

9. The conveying system according to claim 3, characterized in that The head end component further includes a shell, the shell covers the expandable device, and the shell and the expandable device are an integrally formed structure or a separately formed structure; When the shell and the expandable device are separately formed structures, the shell and the expandable device are at least partially fixedly connected in the circumferential direction.

10. The conveying system according to any one of claims 1 to 9, characterized in that The outer tube assembly includes a sheath tube, and the head end component is arranged at the distal end of the sheath tube and is used to cooperate with the sheath tube; When the head end component is expanded, the maximum radial dimension of the head end component is the same as the maximum radial dimension of the sheath tube.

11. The conveying system according to claim 10, characterized in that The sheath tube has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the ratio of the maximum radial dimension of the sheath tube in the expanded state to the maximum radial dimension of the sheath tube in the contracted state is not less than 1.

05.

12. The conveying system according to claim 11, characterized in that The ratio of the maximum radial dimension of the sheath tube in the expanded state to the maximum radial dimension of the sheath tube in the contracted state is not higher than 1.

3.

13. The conveying system according to any one of claims 1 to 9, characterized in that: The outer tube assembly includes a sheath tube, and the head end component is arranged at the distal end of the sheath tube; The sheath has at least a contracted state and an expanded state, and can be switched between the contracted state and the expanded state; the maximum radial dimension of the sheath after expansion is the same as the maximum radial dimension of the head end component after expansion, and the maximum radial dimension of the sheath after contraction is smaller than the distal inner diameter of the catheter sheath.

14. The conveying system according to claim 13, characterized in that The sheath tube includes a tube body and a connecting structure; the tube body has openings along the circumferential direction, the openings are continuously arranged along the axial direction, and the opening and closing of the openings correspond to the state conversion of the sheath tube; the connecting structure is connected to both sides of the opening.

15. The conveying system according to claim 14, characterized in that The sheath tube further includes a reinforcement structure, which is continuously disposed in the tube body along at least a portion of the circumference of the tube body, and the reinforcement structure does not overlap in the circumferential direction of the tube body.

16. The conveying system according to claim 13, wherein: The sheath tube has at least one folding area along the circumferential direction when in the contracted state. The folding areas are continuously arranged along the axial direction. The opening and closing of the folding areas corresponds to the state conversion of the sheath tube.

17. The conveying system according to any one of claims 1 to 9, characterized in that It also includes a catheter sheath, and the outer tube assembly includes a sheath tube and a delivery outer tube connected in sequence; when the delivery system is in a delivery state, the catheter sheath is outermost on the delivery outer tube; when the head end component is in an expanded state, the maximum radial dimension of the head end component is greater than the distal inner diameter of the catheter sheath; when the head end component is in a contracted state, the maximum radial dimension of the head end component is smaller than the distal inner diameter of the catheter sheath.

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