CN116269930A

CN116269930A - Conveying system

Info

Publication number: CN116269930A
Application number: CN202111572791.1A
Authority: CN
Inventors: 姜智博; 陈国明
Original assignee: Shanghai Microport Cardioflow Medtech Co Ltd
Current assignee: Shanghai Microport Cardioflow Medtech Co Ltd
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2023-06-23

Abstract

The invention provides a conveying system, which comprises an outer pipe assembly and an inner pipe assembly, wherein a part of the inner pipe assembly is arranged in the outer pipe assembly, the inner pipe assembly and the outer pipe assembly can move relatively, the inner pipe assembly comprises an inner pipe and a head end part, the head end part is arranged at the distal end of the inner pipe, and the head end part at least has a contracted state and an expanded state and can be switched between the contracted state and the expanded state; after the head end section is contracted, at least a portion of the radial dimension of the head end section is reduced; by the configuration, secondary damage to the blood vessel can be effectively reduced, and vascular complications are reduced.

Description

Conveying system

Technical Field

The invention relates to the technical field of medical equipment, in particular to a conveying system.

Background

The heart valve is a gate of heart blood circulation, once stenosis or insufficiency occurs, the heart can be in insufficient power or failure, and symptoms such as chest distress, asthma, whole body edema, weakness, chest pain and the like appear, so that the heart valve is a hidden danger which endangers the life and the life quality of the old. With the aging population and the development of medical technology, heart valve disease (Valvular Heart Disease, abbreviated as VHD) has become the third largest cardiovascular disease, severely jeopardizing human health. Taking Aortic Stenosis (AS) AS an example, aortic Stenosis is one of the most common valvular heart diseases in heart valve diseases, with the incidence increasing with age (> population aged 65 increases at 2% per year, > population aged 75 increases at 3% per year, > population aged 85 increases at 4% per year). 33% of patients with aortic valve stenosis can not be treated, the death rate of 2 years reaches 50%, and the death rate of 5 years reaches 80%.

Transthoracic direct-view surgical aortic valve replacement with the assistance of extracorporeal circulation has been the only treatment that can extend the life of patients with severe aortic valve stenosis. Although complications and mortality of surgical aortic valve replacement continue to decrease with the continued advancement of surgical, anesthesia, and intensive care techniques. However, once typical symptoms or defined left ventricular dysfunction are present, the outcome of the disease will be dramatically worsened and current guidelines for treatment of aortic valve stenosis will list this as an absolute indicator of surgical valve replacement. Elderly patients often contraindicated for surgery due to advanced age, physical weakness, severe lesions or complicated with other diseases, which limit the applicable population for surgery.

In recent decades, international transcatheter valvular interventional therapy has been continuously explored to make great progress, becoming a branch of the most promising field of interventional cardiology, which is called the fourth revolution in the field of cardiovascular intervention. More and more studies have shown that transcatheter valvular intervention will be an important direction in the development of future heart valve therapies. The american society of thoracic surgeons in combination with the american society of cardiology through catheter valve intervention (Society of Thoracic Surgeons and American College of Cardiology TranscatheterValve Therapy, STS-ACC TVT) registered studies have shown that the surgical volume of the global through catheter aortic valve replacement procedure in 2019 exceeds various forms of surgical aortic valve replacement procedure for the first time, and has become one of the important treatments for symptomatic severe AS.

In recent years, minimally invasive transcatheter valvular interventional procedures have received increasing attention. With the development of transcatheter valvular intervention techniques, new needs and challenges have also been presented. For example, to increase the success rate of surgery, or to ensure the quality of valve prosthesis release, recyclable delivery systems are used. The recyclable delivery system has a higher performance on the delivery catheter, which results in a larger outer diameter delivery catheter, which further increases the requirements on the vascular access and the post-access crossing performance of the delivery catheter.

While transcatheter valvular interventions require pre-dilation of the vessel with a catheter sheath to create a passageway prior to delivery of the delivery system, 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 apparatus, an inline catheter sheath technology is generally adopted, wherein a catheter sheath is sleeved on a delivery catheter of a delivery system, the catheter sheath is positioned between a sheath tube and a handle of the delivery system, the inner diameter of the catheter sheath is smaller than the outer diameter of the sheath tube, a head end part is arranged at the distal end of the sheath tube, and the sheath tube can form a closure with the head end part for coating a valve prosthesis. In the valve prosthesis loading and conveying stage, the maximum outer diameter of the head end part is the same as the outer diameter of the sheath tube so as to meet the sealing requirement of a conveying system; after the valve prosthesis is delivered to the lesion site, the inner and outer tubes of the delivery system are moved relative to each other, and the valve prosthesis is released; after the release is finished, the inner tube and the outer tube are closed, and the conveying system is retracted; during the retraction phase, the inline catheter sheath is retracted together with the delivery system. However, in order to better dilate or conform to the native tissue or other functional requirements of the valve prosthesis, it is generally necessary to deliver a new accessory product, such as a balloon, via the original vascular passageway, during which a new catheter sheath is inserted to create a passageway, since the inline catheter sheath has been withdrawn with the delivery system, which increases the difficulty of the surgical procedure on the one hand and also causes secondary damage to the blood vessel on the other hand. Besides the technology of an inline catheter sheath, a split type catheter sheath technology is adopted, and the technology is to split the catheter sheath and a conveying system; in the conveying process and the retracting process, the conveying system catheter passes through the catheter sheath, and the operation difficulty is high due to the large outer diameter of the conveying catheter, and even the catheter sheath and the conveying system can be withdrawn together, so that the risk of secondary damage to blood vessels is increased, and the problem needs to be solved together. In addition to heart valve prostheses, there is also the problem of secondary damage to blood vessels when using transcatheter delivery of other implanted prostheses.

Disclosure of Invention

The invention aims to provide a conveying system which solves the problem of secondary damage to blood vessels in the existing conveying system.

In order to achieve the above object, the present invention provides a conveying system including an outer tube assembly and an inner tube assembly, a portion of the inner tube assembly being disposed within the outer tube assembly, and the inner tube assembly and the outer tube assembly being capable of relative movement;

the inner tube assembly includes a head end section having at least a contracted state and an expanded state, and being transitionable between the contracted state and the expanded state; after the head end section is contracted, at least a portion of the radial dimension of the head end section is reduced.

Optionally, the ratio of the maximum radial dimension of the head end section in the expanded state to the maximum radial dimension of the head end section in the contracted state is not less than 1.05.

Optionally, the inner tube assembly further comprises an inner core, and the head end part is sleeved on the inner core.

Optionally, the head end component includes an expandable device that is expandable and contractible along with the expandable device.

Optionally, the expandable device is a mesh support structure having at least one end movably disposed relative to the inner core; the net-shaped supporting structure is formed by weaving woven wires or cutting a pipe, or is formed by a plurality of foldable wave rods, and the wave rods are arranged at intervals along the circumferential direction.

Optionally, the inner tube assembly further comprises an inner tube, the inner core is at least partially disposed in the inner tube, the expandable device is composed of a plurality of foldable waverods, the plurality of waverods are circumferentially spaced apart, at least a portion of the proximal ends of the waverods are connected with the distal end of the inner tube, and the distal ends of the waverods are connected with the distal end of the inner core.

Optionally, the delivery system further comprises a manipulation member, at least a portion of the proximal end of the shaft being connected to the distal end of the manipulation member, the manipulation member being configured to control folding and stretching of the shaft.

Optionally, the expandable device is an expandable body made of a high molecular material, the expandable body having a lumen for injecting filling medium, the expandable body being fixed to the inner core; a channel for conveying filling medium is arranged between the inner core and the inflatable body.

Optionally, the inflatable body is a non-compliant balloon.

Optionally, the head end part further comprises a housing, the housing encloses the expandable device, the housing and the expandable device are in an integrally formed structure or a split-formed structure; when the shell and the expandable device are in a split molding structure, the shell and the expandable device are at least partially fixedly connected in the circumferential direction.

Optionally, the outer tube assembly comprises a sheath, the head end component being disposed at a distal end of the sheath and adapted to mate with the sheath;

when the head end section expands, the maximum radial dimension of the head end section is the same as the maximum radial dimension of the sheath.

Optionally, the sheath has at least a contracted state and an expanded state, and is switchable 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.

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.

Optionally, the outer tube assembly comprises a sheath, the head end component being disposed at a distal end of the sheath;

the sheath having at least a contracted state and an expanded state, and being transitionable 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 part after expansion, and the maximum radial dimension of the sheath after contraction is smaller than the inner diameter of the distal end of the catheter sheath.

Optionally, the sheath comprises a tube body and a connection structure; the tube body has openings in the circumferential direction, the openings being provided continuously in the axial direction, the opening and closing of the openings corresponding to the switching of the state of the sheath; the connecting structure is connected to two sides of the opening.

Optionally, the sheath further comprises a reinforcing structure continuously provided within the tube body along at least a portion of the circumferential direction of the tube body, and the reinforcing structure does not overlap in the circumferential direction of the tube body.

Optionally, the sheath has at least one folding zone in the circumferential direction in the contracted state, the folding zones being arranged axially consecutively, the opening and closing of the folding zones corresponding to a transition of the state of the sheath.

Optionally, the delivery system further comprises a catheter sheath, and the outer tube assembly comprises a sheath tube and a delivery outer tube which are sequentially connected; the catheter sheath is sleeved on the outer conveying pipe in the conveying state of the conveying system; when the head end part is in an expanded state, the maximum radial dimension of the head end part is larger than the inner diameter of the distal end of the catheter sheath; when the head end part is in a contracted state, the maximum radial dimension of the head end part is smaller than the inner diameter of the distal end of the catheter sheath.

In the delivery system provided by the invention, the head end part has at least a contracted state and an expanded state, and is capable of being switched between the contracted state and the expanded state; wherein after the head end section has contracted, at least a portion of the radial dimension of the head end section decreases, where the radial dimension decrease is relative to the head end section in the expanded state. So configured, the radial dimension is adjusted by the telescopic head end part, so that the secondary damage to the blood vessel is reduced and the vascular complications are reduced on the basis of ensuring the sealing performance and the crossing performance of the conveying system. Moreover, when the delivery channel is established by means of the catheter sheath, the head end part can pass through the catheter sheath after being contracted, so that the problem that the catheter sheath is retracted together with the delivery system and needs to be reinserted into the catheter sheath is avoided, and the secondary damage to the blood vessel can be further reduced.

In the delivery system provided by the invention, the sheath tube at least has a contracted state and an expanded state, and can be switched between the contracted state and the expanded state, so that the deformation performance of the sheath tube is improved, the sheath tube has smaller outer diameter after contraction, and the secondary damage to the blood vessel can be further reduced. And when the delivery channel is established by means of the catheter sheath, the contracted sheath tube passes through the catheter sheath more easily, and the secondary damage to the blood vessel is further reduced. In particular, 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, so that the configuration can effectively reduce the manufacturing difficulty of the process under the condition of considering the better conveying performance.

Drawings

Those of ordinary skill in the art will appreciate that the figures are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention. In the accompanying drawings:

FIG. 1 is a schematic diagram of a conveyor system according to a preferred embodiment of the present invention, wherein the conveyor system is a conventional conveyor system;

FIG. 2a is a schematic illustration of a delivery system for an inline catheter sheath according to a preferred embodiment of the present invention, wherein both the head end section and the sheath are in an expanded state;

FIG. 2b is a schematic illustration of a delivery system for an inline catheter sheath according to a preferred embodiment of the present invention, wherein both the head end section and the sheath are in a contracted state;

FIG. 3 is a schematic view of an inner tube assembly according to a preferred embodiment of the present invention;

fig. 4 is a schematic view of a head end assembly according to a first preferred embodiment of the present invention in an expanded configuration;

fig. 5 is a schematic view of a head end part in a contracted state according to a preferred embodiment of the present invention;

FIG. 6 is a schematic structural view of an inner tube assembly according to a second preferred embodiment of the present invention;

fig. 7 is a schematic view of a head end assembly according to a second preferred embodiment of the present invention in an expanded state;

fig. 8 is a schematic view of a head end part in a contracted state according to a second preferred embodiment of the present invention;

FIG. 9a is a schematic view of a sheath with folding wings in a contracted state according to a third preferred embodiment of the present invention;

FIG. 9b is a schematic view of a sheath with folded wings in an expanded state according to a third preferred embodiment of the present invention;

FIG. 9c is a schematic view of a delivery catheter and sheath with folded wings according to a third preferred embodiment of the present invention, wherein the sheath is in a contracted state;

FIG. 10a is a schematic view of a delivery catheter and sheath having a circumferential opening according to a third preferred embodiment of the present invention, wherein the sheath is in a contracted state;

FIG. 10b is a schematic cross-sectional view of a sheath having a circumferential opening provided in accordance with a third preferred embodiment of the present invention;

FIG. 11a is a cross-sectional view of a sheath having a rolled wall fold configuration provided by a third preferred embodiment of the invention wherein the tube body has an overlap region in the circumferential direction;

FIG. 11b is a cross-sectional view of a sheath having a rolled wall fold configuration in which the tube body does not circumferentially overlap, provided in accordance with a third preferred embodiment of the present invention;

FIG. 12 is a perspective view of a sheath having a reinforcing structure therein, wherein the reinforcing structure comprises a ferrule, according to a third preferred embodiment of the present invention;

FIG. 13a is an expanded view of a diamond-shaped eyelet provided by a third preferred embodiment of the invention;

FIG. 13b is an expanded view of an oblong eyelet provided by a third preferred embodiment of the invention;

FIG. 14a is an internal perspective view of a sheath provided by a third preferred embodiment of the present invention, wherein the reinforcing structure comprises a metallic fold-back line;

FIGS. 14 b-14 c are expanded views of a metal fold back line provided in accordance with a third preferred embodiment of the present invention;

FIG. 15a is a schematic view showing a structure of a reinforcing structure comprising sequentially connected C-shaped metal members in a contracted state according to a third preferred embodiment of the present invention;

FIG. 15b is a schematic view of the reinforcement structure of FIG. 15a in an expanded state.

In the figure: 100-handle; 200-a delivery catheter; 201-sheath; 2011-a tube body; 2012-a connection structure; 2013-reinforcing structure; 2013A-extension; 2013B-a folded back section; 2013C-stiffener; 2014-opening; 2015-jacket; 2016-liner; 2017-folding wings; 202-conveying an outer tube; 203-a head end component; 2031-a housing; 2032-mesh support structure; 2032 a-wave rod; 2032 b-slider; 2033-inflatable body; 2034-lumen of inflatable body; 204-an inner tube; 205-an inner core; 300-catheter sheath; 301-conduit section; 302-sheath holder.

Detailed Description

The invention will be further described in detail with reference to the accompanying drawings, in order to make the objects, advantages and features of the invention more apparent. It should be noted that the drawings are in simplified form and are not drawn to scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. As used in this specification, the singular forms "a", "an" and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is usually two or more. In the description of the present invention, unless otherwise indicated, the meaning of "not lower than" is usually greater than or equal to; the meaning of "not higher than" is generally less than or equal to.

In the following description, for ease of description, "distal" and "proximal" are used; "distal" is the side remote from the operator of the delivery system, i.e., the end that first enters the body; "proximal" is the side proximal to the operator of the delivery system; "axial" refers to a direction along the axis of the delivery system. Furthermore, in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the invention.

The core idea of the invention is to provide a delivery system suitable for the delivery of a medical implant, comprising an outer tube assembly and an inner tube assembly, a part of the inner tube assembly being arranged in the outer tube assembly, and the inner tube assembly and the outer tube assembly being relatively movable; the inner pipe assembly comprises a telescopic head end part, and the radial size of the head end part is adjustable through the telescopic of the head end part. It is to be understood that the expanded or contracted cross-sectional shape of the head end section includes, but is not limited to, circular; if circular, the radial dimension of the head end part is the outer diameter; if non-circular, the radial dimension of the head end section refers to the maximum width in cross-section. Similarly, in the following description, the radial dimension of the sheath may be the outer diameter when the cross-section is circular, or the maximum width in cross-section when the cross-section is non-circular.

In this application, the delivery process of a medical implant generally includes three phases: the first stage is a medical implant loading and conveying stage, wherein the head end part is in an expanded state, the maximum radial dimension of the head end part after expansion is generally the same as the maximum radial dimension of a sheath tube of a conveying system, and the medical implant is covered by closing the sheath tube and the head end part, so that the medical implant is held under pressure and is limited and loaded in the sheath tube; the second stage is a medical implant release stage, which releases the medical implant by relative movement of the inner and outer tube assemblies; the third stage is to withdraw the delivery system, in which the head end part is in a contracted state, and at least part of the contracted radial dimension of the head end part is reduced, so that the configuration can reduce the secondary damage to the blood vessel caused by the delivery system in the withdrawal stage and reduce the vascular complications. Especially when a delivery channel is established by means of a catheter sheath, the contracted head end part can also pass through the catheter sheath, so that the whole delivery system catheter is withdrawn from the human body, but the catheter sheath still remains in the body, and when a new product such as a balloon needs to be delivered by means of the original vascular channel, the catheter sheath is not required to be reinserted to establish a passage, and further damage to the blood vessel caused by extraction-reinsertion of the catheter sheath is avoided.

The medical implants suitable for delivery by the delivery system disclosed herein may be selected based on the location of the target delivery site, such as medical implants including, but not limited to, heart valve stents. It will be appreciated by those skilled in the art that the delivery system disclosed herein may be used to deliver other medical implants (e.g., vascular stents, aneurysm stents, balloon-expandable stents, ureteral stents, prostatic stents, distal stents, tracheobronchial stents, etc.) to corresponding locations in the body in addition to the heart valve stent. The medical implant may also be a graft, embolic device, occlusion device, or the like. The delivery system disclosed herein may be adapted to the catheter sheath or to situations where there is no catheter sheath.

The delivery system disclosed herein may be a conventional delivery system where the catheter sheath is designed separately from the delivery system, and where the delivery system catheter is passed through the catheter sheath during both delivery and retraction. The delivery system disclosed in the present invention may of course also be a delivery system with an inline catheter sheath, in which case the catheter sheath is pre-sleeved over the delivery system catheter during delivery and retraction. The delivery system disclosed by the invention is a conventional delivery system or an inline catheter sheath delivery system, so that secondary damage to blood vessels can be reduced, and vascular complications can be reduced.

In particular, vascular complications are one of the complications that cannot be ignored in the transcatheter implantation procedure, and the larger outer diameter of the surgical instrument can cause certain damage to the blood vessel. The vessel may be damaged during both the delivery and retraction phases of the implant, especially during the retraction phase, the larger delivery system outer diameter may easily cause secondary damage to the vessel. The inventor carries out a great deal of clinical trial research, and discovers that the degree of vasodilation is controlled within 130 percent (namely, the diameter of the expanded blood vessel is 1.3 times of that of the unexpanded blood vessel) in the delivery stage, and at the moment, the blood vessel can retract automatically, so that the influence on the performance of the blood vessel is small. However, because the blood vessel is retracted, the blood vessel is again damaged when the delivery system is passed through the blood vessel again. Then the smaller delivery system outer diameter may reduce secondary damage to the vessel during the retraction phase, whereas the outer diameter of the conventional head end section is not adjustable and has a larger outer diameter, which may cause secondary damage to the vessel during the retraction phase. In contrast, the delivery system disclosed by the invention can shrink the head end part in the retraction stage, and reduce the radial dimension of the head end part, so that secondary damage to the blood vessel is reduced, and the catheter sheath and the delivery system catheter can be prevented from being retracted together under the condition of the catheter sheath, and further damage to the blood vessel caused by the extraction-insertion of the catheter sheath is avoided.

Further, the sheath has at least a contracted state and an expanded state, and is switchable 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 part after expansion to meet the sealing and traversing performance; and at least part of radial dimension of the sheath after the sheath is expanded is reduced, so that the deformation performance of the sheath can be improved, and the sheath has smaller radial dimension, so that secondary damage to blood vessels is further reduced. In order to reduce the difficulty of manufacturing the process, it is preferable that 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, and in this range, the delivery performance of the sheath loading implant can be considered to be better.

To ensure sealing and ride-through performance of the delivery system, the maximum radial dimension of the head end component generally coincides with the maximum radial dimension of the sheath. Further, the ratio of the maximum radial dimension of the head end section in the expanded state to the maximum radial dimension of the head end section in the contracted state is not less than 1.05, more preferably not more than 1.3.

The delivery system of the present invention will be described in further detail below with reference to the drawings and the preferred embodiments. Further, the following embodiments and features of the embodiments may be complemented or combined with each other without conflict. In the following description, a catheter sheath is schematically illustrated as an example, but this should not be taken as a limitation of the present invention, and the delivery system of the present invention is not limited to the case of adapting a catheter sheath, but may be the case without a catheter sheath.

Referring to fig. 1, a preferred embodiment of the present invention provides a delivery system comprising a handle 100 and a delivery catheter 200; delivery catheter 200 includes inner and outer tube assemblies that are relatively movable, a portion of which is disposed within the outer tube assembly; the outer tube assembly is axially connected with a sheath tube 201 and a conveying 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 includes a head end section 203, the head end section 203 being disposed at a distal-most end of the inner tube assembly, a proximal end of the inner tube assembly being connected to the handle 100. The head end 203 is configured to mate (e.g., close or interference fit) with the sheath 201 to encase and retain the medical implant, and the head end 203 and the sheath 201 may be relatively close or remote.

In one embodiment, referring to fig. 2a and 2b, the delivery system may include an inline catheter sheath 300 (expandable catheter sheath), the catheter sheath 300 being specifically sleeved over the delivery outer tube 202 to form the delivery system of the inline catheter sheath. In another embodiment, referring to fig. 1, the delivery system is a conventional delivery system without an inline catheter sheath 300.

The catheter sheath 300 may employ an existing catheter sheath structure. Generally, the catheter sheath 300 includes a catheter segment 301 and a sheath hub 302, the proximal end of the catheter segment 301 being connected to the sheath hub 302, the distal end of the catheter segment 301 being adapted for insertion into an open end of a predetermined blood vessel. Typically, the distal end of the catheter section 301 has a smaller inner diameter. In the delivery state, the smaller inner diameter of the distal end of the catheter segment 301 prevents the catheter sheath 300 from moving over the sheath 201, avoiding interference with the prosthesis. The distal end of catheter segment 301 is a rigid ring, which may be made of radiopaque material, so that it may be positioned using medical imaging during delivery. The distal inner diameter of catheter sheath 300 refers to the inner diameter of the distal end of catheter section 301. Sheath mount 302 is disposed at the proximal end of catheter segment 301 and serves as a grip for pushing catheter segment 301 into the body. A sealing valve is provided in the sheath hub 302 to ensure that blood loss is minimized throughout operation of the catheter sheath 300. The sheath holder 302 is further connected with an evacuation tube and a three-way stopcock for flushing and evacuating the catheter section 301, and the three-way stopcock can be used for drawing blood samples, pressure detection, injection of drugs or contrast agents, etc. during operation.

In order to solve the problem that the existing delivery system is easy to cause secondary damage to the blood vessel and the problem that the catheter sheath 300 and the delivery system are retracted together when the delivery system is retracted, the invention improves the structure of the head end part 203, so that when the delivery system is retracted, at least part of the radial dimension of the head end part 203 is reduced, thereby not only reducing the secondary damage to the blood vessel, but also enabling the head end part 203 to pass through the catheter sheath 300 so as to withdraw the whole delivery system catheter from the human body, but keeping the catheter sheath 300 in the body and further reducing the damage to the blood vessel.

In more detail, the head end part 203 has at least a contracted state and an expanded state, and is switchable between the contracted state and the expanded state; when the head end 203 is in an expanded state after being expanded, the head end 203 in the expanded state is generally cone-shaped, has a smooth outer surface, and increases in radial dimension from distal end to proximal end, including but not limited to increases in radial dimension sequentially from distal end to proximal end; when the head-end part 203 is contracted, i.e. in a contracted state, at least part of the radial dimension of the head-end part 203 in the contracted state is reduced, and the shape of the head-end part 203 when contracted is not subject to any limitation. In one embodiment, the maximum radial dimension of the contracted head end portion 203 may be less than the distal inner diameter of the catheter sheath 300. It should be further understood that the contracted state of the head end 203 is actually a forced tightening state, and is a state when the head end 203 is subjected to an external force, such as a state when a tensile force or a reduced fluid pressure is applied; the expanded state of the head end 203 is actually a forced expanded state, and is a state when the head end 203 is subjected to an external force, such as a thrust force or an increased fluid pressure. The contracted state may be a pre-molded state, which is an initial state of the head end member 203 in a natural state. In addition, the at least partial radial dimension reduction of the contracted head end portion 203 is understood to mean that the at least partial radial dimension of the head end portion 203 in the contracted state is less than the radial dimension of the head end portion 203 in the expanded state, and generally the radial maximum dimension (preferably the maximum outer diameter) of the head end portion 203 in the contracted state is less than the radial maximum dimension (preferably the maximum outer diameter) of the head end portion 203 in the expanded state. That is, the head end 203 may be partially contracted or entirely contracted after being expanded, whereas the head end 203 may be partially expanded or entirely expanded after being contracted.

It should be appreciated that, by utilizing the telescoping property of the head end 203, the maximum radial dimension of the head end 203 after being expanded is the same as the maximum radial dimension of the sheath 201 to meet the sealing requirement of the delivery system, and the distal end of the entire delivery system is smoothly transited to meet the traversing performance requirement, and the maximum radial dimension of the head end 203 can be reduced, especially when the delivery system is retracted, such that the maximum radial dimension of the head end 203 after being contracted is smaller than the inner diameter of the catheter sheath 300. The reduction in the radial dimension of the head end section 203 in the case of the catheter sheath 300 during the retraction phase may then also enable the head end section 203 to pass through the catheter sheath 300, achieving the purpose of retracting only the delivery system catheter while retaining the catheter sheath 300 in the body. So constructed, the problem of the prior art that the larger outer diameter of the delivery system easily causes secondary damage to the blood vessel is solved, and the problem of the prior art that the catheter sheath 300 is withdrawn and reinserted to establish a passage is also solved, so that the operation difficulty is reduced, the damage to the blood vessel is effectively avoided, the vascular complications are reduced, and the effect of the operation treatment is improved.

In an embodiment, the head end part 203 comprises an expandable device, which is expandable and contractible, the expansion and contraction of the head end part 203 being achieved mainly by the expansion and contraction of the expandable device. The structure of the expandable device is not limited in this application, for example, the expandable device may be a mesh-shaped support structure, which may be formed by cutting a tube or braiding a braided wire, or may be composed of a collapsible waved rod, or may be an expandable body that is deformable in itself. The inflatable body is made of medical polymer materials and is provided with a cavity for injecting filling media, so that the expansion and contraction of the inflatable device are controlled through the pressure of the filling media, but the type of the filling media is not limited, and the inflatable body can be physiological saline, contrast agent and the like.

Further, the inner tube assembly also includes an inner core over which the expandable device is over-wrapped. In an exemplary embodiment, the expandable device is a mesh support structure having at least one end movably disposed relative to the inner core. Further, the proximal end of the mesh support structure is movably disposed relative to the inner core, and the distal end is fixedly coupled to the inner core. Still further, a proximal end of the mesh support structure is coupled to a slider that is movable relative to the inner core.

In another exemplary embodiment, the inflatable body employs a medical balloon. The medical balloon has good expansion performance and controllable radial dimension. Preferably, the medical balloon is a non-compliant balloon, and the non-compliant balloon mainly adopts one or a plurality of combination mixtures or composites of polyamide, polyester, polyvinyl chloride, nylon elastomer and polyurethane elastomer.

Further, after the head-end part 203 is shrunk, the radial dimensions of the head-end part 203 are the same, that is, the head-end part 203 has a uniform radial dimension after being shrunk, at this time, the head-end part 203 may be cylindrical, so as to obtain the head-end part 203 with a smaller radial dimension, which has better retractive performance. In order to facilitate passage of the delivery system through the blood vessel, the head end section 203 in the contracted state is generally tapered.

In one embodiment, the head end 203 further comprises a housing that encloses the expandable device, the expandable device being covered entirely by the housing, the housing having a smooth surface and protecting the expandable device, reducing damage to the blood vessel by the head end 203. While the housing has a higher elongation at break and is capable of telescoping with the expandable device to increase or decrease the radial dimension of the head end section 203. The material of the housing is typically a medical polymer material such as one or more of polyether block Polyamide (PEBAX), polyethylene, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), high Density Polyethylene (HDPE), and Thermoplastic Polyurethane (TPU). In general, the material of the housing should be selected to have good elasticity, such as thermoplastic polyurethane or polyether block polyamide. Further, the housing can be developed so that an operator can determine the location of the distal end of the delivery system based on the development of the head end 203 under X-rays. In general, the polymer material for the casing is added with a developer, and the material of the developer is not limited, and may be one or a combination of a plurality of barium sulfate, tungsten powder, bismuth carbonate, bismuth oxide, and platinum iridium alloy. In some embodiments, the housing is integrally formed with the expandable device, such as when the head end component 203 is a profiled balloon; in other embodiments, the housing is formed separately from the expandable device, and the housing is fixedly connected to the expandable device, and the manner of fixing connection between the housing and the expandable device is not limited, for example, stitching, binding, glue bonding, etc., and preferably, the housing and the expandable device are at least partially fixedly connected in the circumferential direction.

In one embodiment, the inner tube assembly has a steering channel through which an external steering member passes, the steering member being connected to the expandable device and handle 100 via the steering channel. The healthcare worker controls the control component through the handle 100, so that the control component drives the expandable device to stretch and retract. The control component may be a wire, a rope, a belt, a rod or the like, and in this example, the control component is a driving wire or a driving rod, which is not particularly limited. In other embodiments, the inner tube assembly has a passageway for delivering inflation medium to, or from, the expandable device, which is then expanded or contracted by a change in pressure of the internal inflation medium.

Further, the present inventors have found that although the conventional sheath tube is a polymer tube and has a certain deformability, the conventional sheath tube does not actually deform much, and there is a risk that the sheath tube does not easily pass through the catheter sheath 300 when the delivery system is retracted. In order to reduce the risk, the invention improves the structure of the sheath tube, increases the deformation performance of the sheath tube, ensures that the sheath tube 201 has smaller radial dimension after shrinkage so as to further reduce secondary damage to the blood vessel, and can ensure that the sheath tube 201 can pass through the catheter sheath 300 more smoothly so as to further reduce the damage to the blood vessel. Specifically, the sheath 201 has at least a contracted state and an expanded state, and is switchable 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 part 203 after expansion; and the maximum radial dimension of the contracted sheath 201 is smaller than the distal inner diameter of the catheter sheath 300; so configured, not only does the sheath 201 have a smaller outer diameter when the delivery system is retracted, but the difficulty of the sheath 201 passing through the catheter sheath 300 is reduced, allowing the entire delivery system to more smoothly evacuate the body and reducing trauma to the blood vessel.

The structure of the head member 203 will be described in further detail in connection with several preferred embodiments, but the following list is intended to be illustrative only and not limiting in any way.

Example 1

Referring to fig. 3 to 5, in this embodiment, the head end 203 is disposed at the most distal end of the inner tube assembly, and includes a rounded outer shell 2031, and the expanded outer shell 2031 has a tapered shape. The head end section 203 further comprises an expandable device that is a mesh support structure 2032, the mesh support structure 2032 being disposed within the housing 2031. In the expanded state of the housing 2031, the radial dimensions and axial length of the mesh support 2032 are adapted to the housing 2031. The housing 2031 contracts with the contraction of the mesh support structure 2032 and expands with the expansion of the mesh support structure 2032.

In this embodiment, the inner tube assembly includes an inner tube 204 and an inner core 205, the inner core 205 being at least partially disposed within the inner tube 204. In one 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. The interior of the inner core 205 may be threaded.

In this example, the mesh support structure 2032 is composed of a plurality of collapsible waverods 2032a, the plurality of waverods 2032a are circumferentially spaced apart, at least a portion of the proximal ends of the waverods 2032a are connected to the distal end of the inner tube 204, and the distal ends of the waverods 2032a are connected to the distal end of the inner core 205. In another example, the proximal ends of all of the waverods 2032a are connected to the distal end of the inner tube 204, and at least a portion of the distal ends of the waverods 2032a are connected to the distal end of the inner core 205. Thus, by manipulating the folding and unfolding of at least a portion of the waverods 2032a, the contraction and expansion of the mesh support 2032 can be achieved.

In a specific embodiment, the distal ends of all the waverods 2032a are fixedly connected with the distal end of the inner core 205, and the proximal end of one part of the waverods 2032a is fixedly connected with the distal end of the inner tube 204, and the proximal end of the other part of the waverods 2032a is connected with the control component, so that the waverods 2032a connected with the control component can be folded and stretched under the drive of the control component, and realize non-equal-diameter retraction. In another embodiment, the distal ends of all the waverods 2032a are fixedly connected with the distal end of the inner core 205, and the proximal ends of all the waverods 2032a are connected with the manipulation member, so that all the waverods 2032a can be folded and stretched under the drive of the manipulation member, and the isodiametric retraction is realized. Furthermore, the manipulation member may be directly or indirectly connected to the waverod 2032a. Further, the distal end of the steering member is connected to the proximal end of at least a portion of the waver rod 2032a, and the proximal end of the steering member is adapted to be connected to the handle 100 after passing through the gap between the inner tube 204 and the inner core 205.

In one example, the distal end of the mesh support structure 2032 is fixed to the distal end of the inner tube 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 enabling variability in the radial dimension of the head end section 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 enabling variability in the radial dimension of the head end section 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. At this time, the maximum radial dimension of the mesh support structure 2032 is increased or decreased by the relative movement of the proximal and distal ends of the mesh support structure 2032, thereby enabling the radial dimension of the head end section 203 to be varied.

Fig. 4 is an expanded state view of the mesh support structure 2032. As shown in fig. 4, in a specific example, the proximal ends of all the waverods 2032a are fixed on one slider 2032b, and the distal ends of all the waverods 2032a are fixedly connected with the distal end of the inner core 205. By the back and forth movement of the slider 2032b, the proximal end of the mesh support 2032 is moved relative to the distal end. As shown in fig. 4, as the proximal end of mesh support structure 2032 is moved in a proximal direction, the radial dimension of mesh support structure 2032 increases until the maximum radial dimension of head end section 203 matches the maximum radial dimension of sheath 201, as long as the expanded state of head end section 203 is maintained. The sliding block 2032b may be a sleeve structure, and a plurality of mounting holes are circumferentially arranged on the sleeve structure at intervals, and the proximal end of each wave rod 2032a is fixedly connected with a corresponding one of the mounting holes.

Fig. 5 is a contracted state diagram of the mesh support structure 2032. As shown in fig. 5, as the proximal end of the mesh support 2032 moves away from the distal end, the radial dimension of the mesh support 2032 becomes smaller until the maximum radial dimension of the head end section 203 is smaller than the inner diameter of the catheter sheath 300. Preferably, the waverods 2032a are extendable to a straight state to minimize the radial dimension of the head end section 203.

In order to better control the radial dimensional change of the mesh support 2032, the delivery system preferably further comprises the steering component, which may be directly or indirectly connected to the waverod 2032a to drive the waverod 2032a to telescope.

In one embodiment, the manipulation member comprises at least one driving wire, one end of the at least one driving wire is connected to the slider 2032b (see fig. 4 and 5), and the other end of the at least one driving wire is connected to the handle 100 after passing through the catheter of the delivery system, so that the at least one driving wire pushes and pulls the slider 2032 b. For example, as shown in fig. 3, at least one drive wire may be threaded through the gap between the inner core 205 and the inner tube 204. In another embodiment, the manipulation member comprises at least one driving rod, one end of at least one driving rod is connected to the slider 2032b, and the other end of at least one driving rod passes through the catheter of the delivery system and then is connected to the handle 100, so that the driving rod pushes and pulls the slider 2032 b. However, in other embodiments, the slider 2032b may be omitted, and the wave lever 2032a may be directly connected to the control element, for example directly to at least one drive wire or directly to a drive lever.

Further, a control component, such as a control button, may be disposed on the handle 100, and the control component is moved (e.g., moved or rotated) by the movement of the control component.

As a preferred embodiment, the proximal ends of all the waverods 2032a of the mesh-shaped supporting structure 2032 are connected with at least one driving wire, at least one driving wire is inserted between the inner core 205 and the inner tube 204, and the distal ends of all the waverods 2032a are fixed at the distal end of the inner core 205, and the control button on the handle 100 is manually operated to drive at least one driving wire to move, so as to finally drive the mesh-shaped supporting structure 2032 to fold and extend.

As another preferred embodiment, the proximal ends of all the waverods 2032a of the mesh-shaped supporting structure 2032 are connected with a driving rod, one driving rod can be sleeved on the inner tube 204, the distal ends of all the waverods 2032a are fixed at the distal end of the inner core 205, and the control button on the handle 100 is manually operated to drive one driving rod to move, so as to finally drive the mesh-shaped supporting structure 2032 to fold and extend.

The head end 203 may be provided separately so as to be separable from the duct of the inner tube assembly, or may be integrated with the duct of the inner tube assembly so that the head end 203 and the duct are not separable. If the head end part 203 is an independent part, the head end part 203 can be provided with an independent inner core, and the inner core is assembled and connected with the inner pipe 204 and the inner core 205, so that the head end part 203 is arranged independently, and the head end part 203 can be replaced conveniently at any time.

The material of the housing 2031 is not limited in this embodiment. The housing 2031 is typically made of a polymer material with excellent elasticity to cover the whole mesh support structure 2032, and two ends of the housing are fixedly connected to the mesh support structure 2032, such as by stitching, binding, adhesion, etc., to form the outer surface of the head end 203. The material of the housing 2031 is an elastomer, such as a TPU material (thermoplastic polyurethane) or a polyether polyester block copolymer, such as Pebax material (polyether block polyamide) or the like, which has a high elongation at break, and can be stretched radially when the mesh support 2032 expands and recover when the mesh support 2032 contracts, i.e., the housing 2031 can accommodate the expansion and contraction of the mesh support 2032. Preferably, the housing 2031 is fixedly connected to the mesh support 2032 at a circumferential portion thereof, and the connection manner is not limited, and conventional manufacturing processes such as adhesion, sewing or binding may be selected.

The material of the mesh-shaped supporting structure 2032 is not limited in this embodiment, and may be a medical polymer material or a medical metal material, including but not limited to a metal elastic material. Preferably, the material of the mesh support 2032 is one or more combinations of nitinol, stainless steel, cobalt chrome, nickel cobalt alloy, and the like. In other embodiments, the material of the mesh support structure 2032 is a medical polymer material, such as polylactic acid.

In this embodiment, a manipulation channel may be disposed between the inner tube 204 and the inner core 205, where the manipulation channel is used for passing through a manipulation component.

It should be understood that, in this embodiment, the radial dimension of the head end 203 is adjustable by using the shrinkage or expansion of the mesh support structure 2032, which has a simple structure, is convenient to manufacture, is easy to control, and the radial dimension of the head end 203 is controllable, so that the safety of the operation can be ensured.

< example two >

The structure of the head end part provided in this embodiment is substantially the same as that of the head end part in the first embodiment, and for the same point, the detailed description will not be given with reference to the first embodiment, and the following description will mainly be made with respect to the different points.

Referring to fig. 6 to 8, in this embodiment, the expandable device is an expandable body 2033, and the expandable body 2033 is made of a medical polymer material and has a certain elasticity, and can expand after filling with a filling medium and contract after draining or reducing the filling medium. The inflatable body 2033 may be a medical balloon or other inflatable body that is pre-plastically deformable.

Specifically, the inflatable body 2033 has at least two states, a contracted state and an expanded state, and transitions between the contracted state and the expanded state; the contracted state of the inflatable body 2033 is in fact a pre-shaped state, and the expanded state of the inflatable body 2033 is in fact a forced expanded state, wherein the pre-shaped state is the initial state of the inflatable body 2033 in its natural state; the expanded state is the state when the inflatable body 2033 expands after filling.

Fig. 7 is a cross-sectional view of the head end 203 in an expanded state. As shown in fig. 7, after inflation of lumen 2034 of inflatable body 2033 with inflation medium, inflatable body 2033 expands to increase the radial dimension of head end section 203 until the maximum radial dimension of head end section 203 matches the maximum radial dimension of sheath 201, after which inflation pressure of inflatable body 2033 is maintained.

Fig. 8 is a cross-sectional view of the head end 203 in a contracted state. As shown in fig. 8, the lumen 2034 of the expandable body 2033 is retracted after venting, allowing the radial dimension of the head end section 203 to be reduced, and further allowing the maximum radial dimension of the head end section 203 to be less than the distal inner diameter of the catheter sheath 300.

The medical polymer material for preparing the inflatable body 2033 is not limited in this embodiment, and conventional medical polymer materials such as one or more of polyamide, polyester, polyvinyl chloride, nylon elastomer and polyurethane elastomer may be used.

Further, the exterior of the inflatable body 2033 is covered with a housing (not shown) to increase the strength of the inflatable body 2033. The housing, due to its high elongation at break, can be stretched when the inflatable body 2033 expands fully and recover when the inflatable body 2033 is depressurized or depressurized retracted, so the housing can accommodate the expansion and contraction of the inflatable body 2033.

In this embodiment, as shown in fig. 6-8, the housing and inflatable body 2033 are of an integrally formed structure, such as a pre-formed shaped balloon, the expanded shaped balloon forming an integral head end section 203, preferably a non-compliant balloon, the outer wall of which is generally tapered.

In other embodiments, the housing and the inflatable body 2033 are formed as separate pieces, and the two ends of the housing are fixedly attached, e.g., adhered, to the inflatable body 2033 to form the outer surface of the head end 203. Preferably, the housing is fixedly connected to the expandable body 203 at a circumferential portion thereof in a manner not limited, and conventional manufacturing processes such as adhesion and the like may be selected.

It should be noted that, for a single balloon, when inflated with a filling fluid (e.g., filling fluid) at a nominal pressure (i.e., nominal pressure), the balloon will expand to a certain size, typically when the cross-section of the balloon is substantially circular, and the diameter (referred to as the outer diameter) is the nominal diameter of the balloon. And continuously flushing a balloon with a nominal diameter into the filling fluid to further expand the balloon, wherein the balloon is finally burst by the filling fluid, and when the balloon is burst, the internal pressure of the balloon is the rated burst pressure. In this embodiment, rather than a compliant balloon, it is meant that the balloon has a diameter at rated burst pressure of no more than 15% of the nominal diameter. The head end 203 is a non-compliant balloon that is intended to be in direct contact with human tissue during use, and that is required to have high puncture resistance and a certain compressive strength to avoid puncture by some human tissue, such as calcified annuli and the like.

In this embodiment, the inflatable body 20 is fixed on the inner core 205, the proximal end is fixedly connected to the distal end of the inner tube 204, the distal end is fixedly connected to the distal end of the inner core 205, a channel (not shown) for delivering filling medium is provided between the inner core 205 and the inflatable body 20, the proximal end of the channel is connected to the handle 100, and the distal end is provided with at least one outlet, at least one outlet is communicated with the inner cavity 2034 of the inflatable body 2033. Thereby delivering or discharging inflation medium from the channel to the inflatable body 2033.

It will be appreciated that this embodiment utilizes the contraction or expansion of the inflatable body 2033 to achieve the radial dimension adjustment of the head end section 203, which is simple in structure, easy to manufacture, easy to manipulate, and easy to adjust and control the radial dimension of the head end section 203.

Next, the sheath 201 will be described in further detail with reference to specific examples, but the embodiments listed below do not limit the sheath 201 of the present invention.

Example III

When the delivery system delivers the medical implant, firstly, in the loading and delivery stage of the medical implant, the radial dimension of the sheath 201 after expansion is matched with the medical implant in a press-holding state, and the radial dimension of the sheath 201 after expansion is larger than the radial dimension of the delivery outer tube 202, so that the medical implant is pressed between the sheath 201 and the inner tube 204, and the maximum radial dimension of the sheath 201 after expansion is matched with the maximum radial dimension of the head end part 203 after expansion; second, during withdrawal of the delivery system, the radial dimension of the head end 203 and the radial dimension of the sheath 201 can be reduced, particularly to allow the delivery system catheter to be withdrawn through the catheter sheath 300 more smoothly while the catheter sheath 300 remains in the body.

For example, in the sheath delivery system with an inline catheter illustrated in fig. 2a, both the head end section 203 and the sheath 202 are in an expanded state, and the maximum radial dimension of the head end section 203 and the sheath 202 after expansion is greater than the distal inner diameter of the catheter sheath 300, and is not easily retracted into the catheter sheath 300.

As also illustrated in fig. 2b, in the sheath delivery system with an inline catheter sheath, both the head end section 203 and the sheath 202 are in a contracted state, and the maximum radial dimension of the head end section 203 and the sheath 202 after contraction is smaller than the distal inner diameter of the catheter sheath 300, so that the catheter sheath 300 can be passed smoothly.

The manner in which the diameter of the sheath 201 is varied will be described in further detail with reference to specific examples, but the embodiments listed below do not limit the scope of the sheath 201 of the present invention.

Referring to fig. 9a to 9c, in an exemplary embodiment, the sheath 201 is a polymer tube with folded wings 2017, and the material thereof may be a conventional medical polymer tube, such as Pebax series, etc. The sheath 201 is circumferentially closed and has at least one folding wing 2017 in the circumferential direction in the contracted state, but the number of folding wings 2017 is not limited to one but may be plural. The folding wings 2017 are continuously provided in the axial direction, and the folding and unfolding of the folding region 2017 corresponds to the switching of the state of the sheath 201. Thus, the presence of the fold wings 2017 allows the sheath 201 to expand radially outward and the sheath 201 is able to self-resume the folded state upon retraction to reduce the radial dimension of the sheath 201. In detail, when the sheath 201 is wrapped around a medical implant (e.g., a heart valve stent), the sheath 201 is expanded, and the sheath 201 is expanded according to the size of the medical implant to such an extent that the sheath 201 can be wrapped around the medical implant, for example, fig. 9b illustrates a state in which the sheath 201 is fully expanded, and at this time, the sheath 201 is expanded to a maximum size after the medical implant is inserted. Referring to fig. 9a and 9c, on the contrary, when the delivery system is retracted, the sheath 201 automatically returns to the original collapsed configuration, allowing the radial dimension of the sheath 201 to be reduced and the catheter sheath 300 to pass therethrough. The provision of the folding wings 2017 also has the advantage of reducing the radial dimension of the pre-shaped state of the sheath 201, which is advantageous for reducing the delivery size.

Referring to fig. 10a and 10b, in another exemplary embodiment, the sheath 201 includes a tube body 2011 and a connection structure 2012. The tube body 2011 has an opening 2014 along the circumferential direction, and the openings 2014 are continuously arranged along the axial direction, and the opening and closing of the openings 2014 correspond to the switching of the state of the sheath 201; the connection structure 2012 connects the two opposite sides of the opening 2014 of the tube body 2011 in the radial direction, so as to connect the two opposite sides of the opening 2014 in the radial direction together. It will be appreciated that where the opening 2014 extends axially of the tube body 2011, the tube body 2011 is configured to have a degree of resiliency, the presence of the opening 2014 allowing the tube body 2011 to expand radially outwardly when the tube body 2011 is subjected to a radially outwardly expanding force. The connection structure 2012 is connected to opposite sides of the opening 2014 in the radial direction, so as to ensure that the outer circumference of the sheath 201 is closed. Preferably, the sheath 201 further comprises a reinforcement structure 2013, the reinforcement structure 2013 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 appreciated that the reinforcement structure 2013 is disposed in the tube body 2011, and includes: in an example, the reinforcement structure 2013 is attached to the inner wall of the tube body 2011, or a concave region adapted to the thickness of the reinforcement structure 2013 is formed on the inner wall of the tube body 2011, and the reinforcement structure 2013 is disposed in the concave region; in another example, the reinforcing structure 2013 is embedded in a sidewall of the tube body 2011, i.e., the reinforcing structure 2013 is embedded in a sidewall of the tube body 2011. The arrangement of the reinforcement structure 2013 can realize radial reinforcement of the tube body 2011, can effectively enhance the bending resistance and compression resistance of the sheath 201, does not influence the expansion performance of the sheath 201, realizes compliant bending in all directions, reduces the risk of bending the sheath 201 due to overlarge bending of a blood vessel, and improves the operation safety.

Preferably, the sheath 201 further comprises an outer sleeve 2015 and/or an inner liner 2016; the outer sleeve 2015 is coated on the outer surface of the tube body 2011, and can elastically stretch and retract to adapt to the stretching of the sheath 201; the inner liner 2016 is attached to the inner surface of the pipe body 2011 and the reinforcing structure 2013. Referring to fig. 10b, in one embodiment, the sheath 201 is mainly divided into four layers from outside to inside, namely, a jacket 2015, a tube body 2011, a reinforcing structure 2013 and a liner 2016. It is to be appreciated that some embodiments may provide both the outer jacket 2015 and the inner liner 2016, while other embodiments may provide one of the outer jacket 2015 and the inner liner 2016 separately.

The outer sleeve 2015 uses a material having higher elasticity than the tube body 2011 to cover the entire circumference, and both ends thereof are adhered to the wall of the tube body 2011 to form the outer surface of the sheath 201. The material of the jacket 2015 may be, for example, TPU (thermoplastic polyurethane) or Pebax (polyether block polyamide) and the like, which has a high elongation at break, and can be stretched radially when the pipe body 2011 expands and recover when the pipe body 2011 contracts, that is, the jacket 2015 can adapt to the expansion and contraction of the pipe body 2011. Preferably, the outer sleeve 2015 is fixedly connected to the pipe body 2011 at a circumferential portion, and the connection manner is not limited, and conventional preparation processes such as adhesion and the like can be selected.

The inner liner 2016 provides a smooth inner wall, forming the inner surface of the sheath 201. In some embodiments, the reinforcing structure 2013 is attached to the inner wall of the tube body 2011, the inner liner 2016 is attached to the inner wall of the tube body 2011 in the region of the tube body 2011 where the reinforcing structure 2013 is not disposed, and the inner liner 2016 is attached to the inner wall of the reinforcing structure 2013 in the region where the reinforcing structure 2013 is disposed. Optionally, a liner 2016 may be attached to the inner side wall of the connection structure 2012 to cover the inner surface of the sheath 201, such that the liner 2016 is disposed on the inner surface of the sheath 201 in a circumferentially closed manner. Preferably, the inner liner 2016 uses a high strength, low coefficient of friction material, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), HDPE (high density polyethylene), etc., to further reduce the coefficient of friction of the inner wall, and to further facilitate insertion and release of the medical implant. Specifically, in some embodiments, the connection structure 2013 may be formed by extending the liner 2016, i.e., the connection structure 2013 is the same material and structure as the liner 2016. Optionally, the inner liner 2016 is fixedly connected to the inner wall of the pipe body 2011 or the inner wall of the reinforcement structure 2013, and the connection manner is not limited, and conventional preparation processes such as adhesion and the like can be selected.

Referring to fig. 11a and 11b, in an exemplary embodiment, the tube body 2011 includes a polymer tube layer with a rolled wall structure, and the material thereof may be a conventional medical polymer tube, such as Pebax series. The macromolecule tube layer is not closed in the circumferential direction. Preferably, when the sheath 201 is in the contracted state, the tube body 201 has an overlapping region along a circumferential direction, the opening 2014 is located in the overlapping region, and the connection structure 2012 is sandwiched in the overlapping region. The overlapping area can be partially unfolded and fully unfolded in the blood vessel of a patient, the expansion degree of the overlapping area is determined by the size of the medical implant, and the overlapping area has the advantages that: on the one hand, the diameter of the sheath 201 in the pre-molded state is reduced, and on the other hand, the overlapping region in the expanded state serves as a part of the sheath 201, so that the buckling resistance of the expanded sheath 201 can be further improved. In other embodiments, the two edges of the polymer tube layer in the axial direction are gradually thinner towards the edges (two sides of the opening 2014), which has the advantages of reducing the thickness of the overlapped area and smoothly transitioning at the opening 2014, facilitating the deployment of the connection structure 2012 and further facilitating the formation of the expanded state. Referring to fig. 11b, in other embodiments, the tube body 2011 is not overlapped in the circumferential direction when the sheath 201 is in the contracted state, and the connecting structure 2012 is overlapped and covered outside the opening 2014 to form a shape similar to a pleat. The circumference of the tube body 2011 is non-overlapping, i.e. there is no overlapping region, while the opening 2014 is directly overlapped by the connection structure 2012, which is preferably a resilient material, to meet the expansion requirement of the sheath 201. Preferably, the connection 2012 is made of a high elasticity, high strength material such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), HDPE (high density polyethylene), etc., and in other embodiments, other materials with similar properties known to those skilled in the art may be used. More preferably, the connecting structure 2012 is configured to be flattened but not stretched so that it returns to its original state better after being expanded so as not to undergo plastic deformation.

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 201 in the contracted state. With continued reference to fig. 10b, the inner circumference of the sheath 201 in the contracted state refers to that, if the tube body 2011 has a circumferential overlapping region, the inner circumference does not include the body section overlapped by the overlapping region, but only covers the tube body 2011 with a circumferential angle of 360 °. Specifically, in the pipe body 2011 illustrated in fig. 10b, from the opening of the pipe body 2011 at the inner side of the overlapping region, the pipe body extends circumferentially around the inner wall of the pipe body counterclockwise to a position corresponding to the opening of the pipe body at the inner side of the overlapping region, without continuing to extend toward the overlapping region. The extension length of the reinforcement structure 2013 is not less than 3/4 of the inner perimeter, and it is understood that one or both ends of the reinforcement structure 2013 may extend into the overlapping region, and that both ends of the reinforcement structure 2013 may be located outside the overlapping region according to the length of the overlapping region. If the tube body 2011 is circumferentially non-overlapping, as shown in fig. 11b, the inner circumference of the sheath 201 in the contracted state refers to the circumference of the tube body extending along the entire inner wall, and it should be understood that in some special cases, such as when the sheath 201 is in the contracted state, the tube body is not circumferentially closed at the opening 2014, and the circumferential coverage angle of the inner circumference is less than 360 °, i.e. only fits the inner wall of the tube body.

The reinforcement structure 2013 preferably comprises a metal layer with better elasticity, and the ratio of the extension length to the inner circumference of the reinforcement structure 2013 ranges from 3/4 to 1, so that the reinforcement structure 2013 presents a C shape in the circumferential direction, the overall rigidity of the sheath 201 is increased, and the sheath 201 can be automatically restored to a contracted state, namely to an original opening state after external force is removed.

As shown in fig. 12, in an exemplary embodiment, the reinforcement structure 2013 includes a metal ring, and the metal ring has a length along the circumferential direction of the tube body 2011 that is greater than a length along the axial direction of the tube body 2011, that is, when the metal ring is unfolded, the metal ring is rectangular in the circumferential direction, and the long side is perpendicular to the axis of the tube body 2011. In the present invention, the shape is not limited to a rectangle having a long side perpendicular to the axis of the tube body, and may be a rectangle having a long side parallel to the axis of the tube body, a square, an oval, or the like. Preferably, the reinforcement structure 2013 includes a plurality of metal rings, and a plurality of the metal rings are arranged along an axial direction of the tube body 2011. The provision of the ferrule provides a high degree of flexibility in terms of bending resistance, enabling compliant bending of the sheath 201 in all directions.

The shape of the eyelet is not required in this application, as may be the diamond eyelet of fig. 13a, or the oblong eyelet of fig. 13b, but it will be appreciated that one skilled in the art may also provide the eyelet with other shapes, such as a ring shape, a quadrilateral shape, an oval shape, etc. Preferably, a plurality of metal rings are arranged at intervals, the size of each metal ring can be the same or different, the shape of each metal ring can be the same or different, and the interval distance between the metal rings can be the same or different. The mutually independent and spaced metal rings can ensure that the circumferential stress of the sheath 201 is more uniform during expansion and the shape recovery is better. The spacing between two axially adjacent metal rings can be different, so that different bending resistance can be realized, and the axial compression resistance can be effectively realized by denser distribution. The spacing between the metal rings can be set by those skilled in the art based on the actual circumstances. The metal rings are arranged in parallel or are not limited to be parallel, and the adjacent metal rings can be arranged at an angle, for example, every two metal rings are arranged in a group in an eight shape, the metal rings can be arranged in a group in a Sichuan shape, or the metal rings are repeatedly arranged in a group, and the metal rings can be arranged at an angle not according to a rule. The angularly aligned metal rings provide a certain supporting force to the shaft when the sheath 201 is expanded, improving the bending resistance thereof.

In other embodiments, a plurality of the metal rings are arranged at intervals, and the lengths of the metal rings in the circumferential direction of the tube body gradually decrease from the proximal end to the distal end in the axial direction of the tube body. The proximally located eyelet is longer along the circumferential length of the tube body, relatively closer to the delivery outer tube 202, and the distally located eyelet is smaller along the circumferential length of the tube body, relatively farther from the delivery outer tube 202. In practice, the sheath 201 can expand to different degrees according to different expansion requirements of the distal end and the proximal end, the radial expansion force applied at the initial stage of expansion is small, and the long metal ring can better maintain small deformation, so that the stability during expansion is improved, and the operation is convenient. In other examples, the spacing distance between the metal rings increases gradually from the proximal end to the distal end along the axial direction of the tube body. I.e., the metal rings closer to the delivery outer tube 202 are more densely distributed and the metal rings farther from the delivery outer tube 202 are more loosely distributed. This also allows for the sheath 201 to expand to different degrees depending on the expansion requirements of the distal and proximal ends.

In another example, a plurality of the metal rings are arranged adjacently in turn, each of the metal rings being identical in size and shape, and the plurality of the metal rings being arranged parallel to each other. The adjacent metal rings are connected with each other to form a pattern similar to a woven net, and the advantage of the arrangement provides good compression resistance for the continuous metal rings, simultaneously enhances the torsion control performance, and compared with the design of the spaced metal rings, the metal rings which are arranged adjacently in sequence play a strong supporting role, effectively improve the compression resistance of the sheath 201, and simultaneously enhance the torsion control performance of the sheath 201. Of course, in other examples, the person skilled in the art may also configure the plurality of metal rings to be sequentially overlapped, that is, to have mutually overlapped portions between the metal rings, to form a grid shape, so that the supporting performance of the metal rings may be further improved.

As shown in fig. 14a, in one exemplary embodiment, the reinforcement structure 2013 includes a metal return line having an extension length along the circumferential direction of the tube body 2011 that is greater than a return length along the axial direction of the tube body. The bending resistance of the sheath 201 can be further improved by setting the metal bending line, and the bending structure can realize better compression resistance. Preferably, the metal back folding line can be woven by one metal wire, or can be formed by connecting in a bonding, welding or other modes after split manufacturing. The metal back folding line can be designed by using U-shaped, V-shaped, S-shaped, Z-shaped or arched braiding and the like. Referring to fig. 14B, in general, the metal return line includes an extension section 2013A and a return section 2013B, the extension section 2013A extends along the circumferential direction of the pipe body, and the return section 2013B extends along the axial direction of the pipe body. The metal reverse fold line connects the extension sections 2013A arranged circumferentially through the folding sections 2013B, so that the axial compressive resistance of the sheath 201 is improved, the bending resistance is also improved, and the overall shape of the sheath 201 is ensured to be stable while being expanded.

Referring to fig. 14C, in a specific embodiment, the reinforcement structure 2013 may further include a reinforcement rib 2013C disposed along an axial direction of the tube body 2011, where the reinforcement rib 2013C sequentially penetrates through the plurality of metal rings or the metal back-folding line. Optionally, the reinforcement rib 2013C may be at least one, and preferably, the reinforcement rib 2013C is located at the center of the metal ring or the metal back-folding line along the circumferential direction of the tube body. Optionally, the reinforcement structure 2013 comprises a number of equally spaced metal rings. Preferably, the stiffener 2013C is disposed on the inner layer of the ferrule, at the central axis of the ferrule structure, which effectively enhances the axial compression and torsional deformation resistance of the sheath 201. The reinforcing rib 2013C effectively bears the axial pressure of the sheath 201, so that the metal ring fully performs radial expansion and recovery functions, and meanwhile, the overall bending resistance of the sheath 201 with the reinforcing rib 2013C is obviously improved. It should be noted that, according to the number of the reinforcing ribs 2013C actually set, the reinforcing ribs 2013C may be added to the metal reverse fold line by those skilled in the art, which also has a better effect. Preferably, the material of the metal ring, the metal back-fold line or the reinforcing rib 2013C may be selected from a memory alloy material to improve the pre-forming ability and the restoring ability of the reinforcing structure 2013 after expansion.

Referring to fig. 15a and 15b, in another exemplary embodiment, the reinforcement structure 2013 may be a skeleton structure formed by sequentially connecting a plurality of C-shaped metal pieces in series, and the skeleton structure can effectively enhance the axial compression and buckling deformation resistance of the sheath 201. The number of C-shaped pieces is dependent on the axial length of the sheath 201. Wherein fig. 15a illustrates the reinforcement structure 2013 in a contracted state and fig. 15b illustrates the reinforcement structure 2013 in an expanded state.

In summary, the delivery system of the invention realizes the radial dimension adjustment of the head end part through the telescopic head end part, so that the head end part has smaller radial dimension after contraction on the basis of ensuring the sealing performance and the traversing performance of the delivery system, thereby reducing the secondary damage to the blood vessel, and when the delivery channel is established by means of the catheter sheath, the contracted head end part can also pass through the catheter sheath, thereby avoiding the problem that the catheter sheath and the delivery system are retracted together, further reducing the damage to the blood vessel, improving the safety of the operation and reducing the vascular complications. In addition, the deformation performance of the sheath tube is enhanced through the structural design of the sheath tube, so that the sheath tube has smaller radial dimension after being contracted, thereby further reducing the secondary damage to the blood vessel, and the contracted sheath tube can also more easily pass through the catheter sheath when a conveying channel is established by means of the catheter sheath, and further solving the problem that the catheter sheath and the conveying system are retracted together.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the present invention.

Claims

1. A delivery system comprising an outer tube assembly and an inner tube assembly, a portion of the inner tube assembly disposed within the outer tube assembly, and the inner tube assembly and the outer tube assembly being capable of relative movement;

2. The delivery system of claim 1, wherein a ratio of a maximum radial dimension of the head end section in the expanded state to a maximum radial dimension of the head end section in the contracted state is not less than 1.05.

3. The delivery system of claim 1, wherein the inner tube assembly further comprises an inner core over which the head end component is over-molded.

4. A delivery system according to claim 3, wherein the head end component comprises an expandable device, the expandable device being expandable and contractible along with the expandable device.

5. The delivery system of claim 4, wherein the expandable device is a mesh support structure having at least one end movably disposed relative to the inner core; the net-shaped supporting structure is formed by weaving woven wires or cutting a pipe, or is formed by a plurality of foldable wave rods, and the wave rods are arranged at intervals along the circumferential direction.

6. The delivery system of claim 4, wherein the inner tube assembly further comprises an inner tube, the inner core being at least partially disposed within the inner tube, the expandable device being comprised of a plurality of collapsible wavebars, the plurality of wavebars being circumferentially spaced apart, and at least a portion of the proximal ends of the wavebars being connected to the distal end of the inner tube, the distal ends of the wavebars being connected to the distal end of the inner core.

7. The delivery system of claim 6, further comprising a steering member, at least a portion of the proximal end of the waverod being coupled to the distal end of the steering member, the steering member being configured to control folding and stretching of the waverod.

8. The delivery system of claim 4, wherein the expandable device is an expandable body made of a polymeric material, the expandable body having a lumen for injection of filling medium, the expandable body being secured to the inner core; a channel for conveying filling medium is arranged between the inner core and the inflatable body.

9. The delivery system of claim 8, wherein the inflatable body is a non-compliant balloon.

10. The delivery system of claim 4, wherein the head end component further comprises a housing encasing the expandable device, the housing being of unitary or split construction with the expandable device; when the shell and the expandable device are in a split molding structure, the shell and the expandable device are at least partially fixedly connected in the circumferential direction.

11. The delivery system of any one of claims 1-10, wherein the outer tube assembly comprises a sheath, the head end component being disposed at a distal end of the sheath and adapted to mate with the sheath;

12. The delivery system of claim 11, wherein the sheath has at least a contracted state and an expanded state, and is switchable 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.

13. The delivery system of claim 12, wherein a ratio of a maximum radial dimension of the sheath in an expanded state to a maximum radial dimension of the sheath in a contracted state is no greater than 1.3.

14. The delivery system of any one of claims 1-10, wherein the outer tube assembly comprises a sheath, the head end component being disposed at a distal end of the sheath;

15. The delivery system of claim 14, wherein the sheath comprises a tube body and a connection structure; the tube body has openings in the circumferential direction, the openings being provided continuously in the axial direction, the opening and closing of the openings corresponding to the switching of the state of the sheath; the connecting structure is connected to two sides of the opening.

16. The delivery system of claim 15, wherein the sheath further comprises a reinforcing structure disposed continuously within the tube body along at least a portion of a circumferential direction of the tube body, and wherein the reinforcing structure does not overlap in the circumferential direction of the tube body.

17. The delivery system of claim 14, wherein the sheath has at least one fold in the circumferential direction in the contracted state, the fold being disposed axially continuously, the opening and closing of the fold corresponding to a transition in the state of the sheath.

18. The delivery system of any one of claims 1-10, further comprising a catheter sheath, the outer tube assembly comprising a sheath tube and a delivery outer tube connected in sequence; the catheter sheath is sleeved on the outer conveying pipe in the conveying state of the conveying system; when the head end part is in an expanded state, the maximum radial dimension of the head end part is larger than the inner diameter of the distal end of the catheter sheath; when the head end part is in a contracted state, the maximum radial dimension of the head end part is smaller than the inner diameter of the distal end of the catheter sheath.