CN215688105U

CN215688105U - Support system with controllable release mechanism

Info

Publication number: CN215688105U
Application number: CN202120373267.0U
Authority: CN
Inventors: 李彪; 胡晓明; 董娟; 陈超
Original assignee: Ningbo Diochange Medical Technology Co Ltd
Current assignee: Ningbo Diochange Medical Technology Co Ltd
Priority date: 2021-02-18
Filing date: 2021-02-18
Publication date: 2022-02-01
Anticipated expiration: 2031-02-18

Abstract

The utility model relates to a stent system containing a controllable release mechanism, which comprises an elastic stent and a conveying system; the support is enclosed into a frame by the support rods and comprises a first support section, a middle support section and a second support section; the first support section comprises a controllable release mechanism comprising a release rod, a release hole, a release ring and a release head; the release holes comprise first release holes, and the first release holes are close to the release heads and have the largest distance from the closed loop contour formed by the far ends of all the release rods; the release rod is positioned at the near end of the first support section and connected with the support rod, the release hole is positioned at the near end of the release rod, the release ring is inserted into the release hole and is in sliding connection with at least one release hole, and the release head is connected with the release ring; the release head is pulled, all the release holes are folded, and the support is driven to contract and load into the conveying system; the second support section and the intermediate support section return to a predetermined shape and the first support section returns to the predetermined shape as the release ring relaxes. The functions of controllable release in the operation and convenient capture and recovery after complete release are realized, and the safety is high.

Description

Support system with controllable release mechanism

Technical Field

The utility model relates to the field of passive instrument therapy for heart failure, in particular to a stent system with a controllable release mechanism.

Background

Heart failure (Heart failure) is the end result of various cardiovascular events and the cumulative effect of various cardiac abnormalities. In some heart diseases, the pressure in the left and right heart rooms can be obviously different, for example, in patients with pulmonary hypertension, the continuous right atrial hypertension exists, the right atrial pressure needs to be reduced, otherwise, the right heart is enlarged and fails, and finally, the heart pumping function is reduced, once the clinical manifestations of heart failure appear in cardiovascular patients, the prognosis is poor, the heart failure is heavier, and the death risk is higher. Heart failure is an abnormal change in the structural function of the heart caused by various causes, causing ventricular systolic ejection and/or diastolic filling dysfunction, resulting in a complex group of clinical syndromes, mainly manifested by a decrease in exercise tolerance (dyspnea, fatigue) and fluid retention (pulmonary congestion, systemic congestion and peripheral hematoma).

Interatrial septal angioplasty is a method for treating complex heart disease, which establishes traffic between the left atrium and the right atrium of a patient by an interventional method, mixes blood in the left atrium and the right atrium, adjusts hemodynamics to a relatively stable state, transmits pressure between the left atrium and the right atrium, relieves cardiac load, and prevents the patient from suffering from cardiac insufficiency.

The V-Wave products, IASD products and the heart failure treatment equipment mentioned in patent EP3171786B1 developed abroad are all cutting stents, the waist of the stents can provide certain supporting force for the shunting holes after puncture, but because the radial supporting force of the cutting stents is larger and the resilience is higher, an operator pushes the stents out from the conveying system, gradually spreads the stents and finally releases the stents to the target position, the stents and the conveying system are usually related with each other only by generating frictional resistance through simple extrusion of the stents and the conveying system, at the moment when the stents are completely separated from the conveying system, such as a sheath tube in the conveying system, due to the huge deformation amount of the proximal end area of the stents, the adverse event of stent bouncing is easily generated, under the condition, the stents either form impact force on the tissues in the target position area to cause physical damage to the target tissues or fly to the non-target position area, for example, stuck at the orifice of the valve, creating a risk to the patient's life; in addition, the product is not provided with a catching structure, so that the product with an unsatisfactory position cannot be smoothly and conveniently recycled to the outside of the body. This is because when the position is unsatisfactory when the product is implanted, perhaps when the operator misoperation drops the product in the human body, the operator accessible catches the waist, perhaps the bracing piece edge of left side dish/right dish even can catch the product, nevertheless because the bracing piece edge of right side dish/right dish can't gather together or gather together the back in disorder, leads to catching the sheath pipe size greatly increased that the product required used. This leads to two situations, 1) the sheath required to catch the product is too large and never sold in the market; 2) if a larger sheath is directly used, a larger wound is generated on the patient. Generally, the smaller the sheath to be inserted through the body's own vascular access, the better, but the clinically recommended maximum is not more than 24Fr, especially when the product is dropped into the pulmonary artery, the required sheath is not more than 14Fr, otherwise, the body may be injured.

Furthermore, a controlled release system as proposed in patent CN110934618A may also have the following effect on the implantation of the atrial septum shunt: a) the instrument may fall to other positions from the interatrial septum tissue, such as the right atrium, the right ventricle, the pulmonary artery, etc., due to improper operation of the operator; b) in the product implantation process, the traction rod at the far end of the conveying system is positioned in the right atrium in a scattered lantern shape, and the ultrasonic effect is possibly influenced; c) the distal end of the delivery system is connected with the product in a filament drawing control mode, which requires that the distal end area of the traction rod has certain rigidity; however, the distal end of the drawbar may contact the atrial septum target tissue or the right atrial luminal surface, and to avoid damage to these tissues, the distal region of the drawbar should be flexible so that the distal end of the drawbar cannot achieve a so-called "adaptive state"; d) clinically, this so-called "adaptive state" results in the distal end of the drawbar not being able to retract smoothly into the sheath, which may result in contact with the right atrial tissue and the tissue of the access passage during retraction, and even damage to some of the contacted tissue; e) in the traction process of the controllable release system, the traction force is only transmitted on the traction frame, so that the far end of the traction rod is elastically deformed, but the traction force cannot be transmitted to the instrument, and whether the instrument is safely fixed in a target area on the interatrial space cannot be accurately judged.

Therefore, there is a need in the market to develop a stent system that is intraoperatively controlled to release, and that is also easy to capture and retrieve after complete release.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art, and provides a stent system with a controllable release mechanism, which realizes that a stent framework, particularly an inner cavity defined by a middle support section of the stent framework is stable after the stent is implanted into a target tissue, and the stent system is convenient to capture and recover after controlled release and complete release in an operation.

In order to achieve the purpose, the utility model adopts the technical scheme that:

a stent system containing a controllable release mechanism comprises an elastic stent and a conveying system for conveying the stent to a target position in a body, wherein the stent is surrounded by supporting rods to form a frame and comprises a first supporting section, a middle supporting section and a second supporting section;

the stent is of a self-expanding structure, the first support section comprises a controllable release mechanism, the controllable release mechanism comprises a release rod, a release hole, a release ring and a release head, and the release hole comprises a first release hole and a tail release hole;

the release rod is positioned at the near end of the first support section and fixedly connected with the support rod at the corresponding position, the release hole is fixedly arranged at the near end of the release rod, the release ring sequentially penetrates through the release hole to form a closed loop, the release ring is in sliding connection with at least one release hole, the release head is connected with the release ring, and the release head is detachably connected with the conveying system;

the bracket is provided with a first state and a second state which can be mutually converted, the release head is pulled, all the release holes are mutually close and furled to drive the bracket to shrink, and finally the whole bracket is linearly loaded or pulled into the conveying system, namely the first state; the second support section and the middle support section are successively restored to a preset shape, then the release lever of the first support section is restored to the preset shape along with the relaxation of the release ring, and the fully-stretched state after the release lever is completely released to the target position is the second shape.

Preferably, the whole support is in a flat I shape, and the support is an atrial septal pore-forming support (namely, an atrial shunt); a tangent plane alpha exists on the edge area of the first supporting section; the tangent plane alpha is perpendicular to the central axis m of the bracket; a tangent plane beta is arranged on the edge area of the second support section; the tangent plane beta is perpendicular to the central axis m of the bracket.

Preferably, the first release aperture is proximate to the release head and is spaced a maximum distance from the closed loop profile defined by the distal ends of all of the release levers.

Preferably, the release hole, the controllable release mechanism and the bracket are of an integrated structure formed by laser engraving and heat setting of the same shape memory alloy tube; the number of the release levers is even and is half of that of the support levers on the first support section; the far ends of the release levers are fixedly connected with the far ends of the support levers on the corresponding first support sections, the near ends of every two adjacent release levers are connected in an intersecting and fixed mode to form a release connecting piece, the point where the near ends of every two adjacent release levers are connected defines an intersecting point, and all the release holes are located in the release connecting piece; on the plane a or the plane β, all the release connections and the release holes are located within the projected area of the first support section.

Preferably, the release lever is provided with an adaptive structure with anatomical shape adaptability, the adaptive structure is radially outwards from the edge of the first support section, then the adaptive structure obliquely spans the edge of the first support section in a bending shape and extends towards the center of the bracket, and the bending angle theta satisfies the following condition: theta is more than or equal to 90 degrees and less than or equal to 175 degrees; or the first support section is radially outward from the edge and then extends in a curved shape on the plane alpha in the direction far away from the bracket, and the bending angle theta satisfies the following condition: theta is more than or equal to 10 degrees and less than or equal to 135 degrees; the bending angle theta is an included angle formed by the radial outward direction of the edge face of the first support section and the inward direction of the tangent of the proximal end of the release lever; on the plane a or the plane β, all the release connections and the release holes are located in or at the periphery of the projected area of the first support section.

Preferably, the release rod is a shape memory alloy thin rod, and the support rod at the edge of the first support section is the release rod; all the release levers and the support are of an integrated structure formed by laser engraving and heat setting of the same shape memory alloy tube, and the release holes are located in the edge area of the release levers; all the release connections and the release holes are located at the edge of the first support section on the planes a and β.

Preferably, the release holes include the first, second and third release holes … … and … …, the first release hole has a minimum distance from the central axis of the stent, and the distances from the first, second and third release holes … … to the central axis of the stent are respectively defined as L₁、L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nWherein L is₁、L₂、 L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nThe mathematical relationship is satisfied: l is₁<L_n<L₂<L₃<……<L_n-1Or L₁<L₂<L₃<……<L_n-1<L_n，L₂＝L₂’，L₃＝L₃’……L_n-1＝L_n-1', the centers of all the release holes are not on the same circle.

Preferably, the number of the release holes is at least 4, and the release rings pass through the first release hole end to end, so that in the second state, the position of the release head relative to the first release hole is defined, and the last release hole comprises a double-hole structure, and the release rings are sequentially inserted into the double-hole structure.

Preferably, the first, second and third release holes … … and the last release hole have a cavity length dimension M on a plane perpendicular to the central axis M and passing through the release holes₁、M₂、M₃……M_nWhen the release ring is linear, the outer diameter of the release ring itself is M₀Then M is₁、M₂、M₃……M_nThe mathematical relationship is satisfied: m₁>2×M₀，M₂>3×M₀，M₃>3× M₀……M_n-1>3×M₀，M₀<M_n≤3×M₀，0.08mm≤M₀≤1mm。

Preferably, the proximal ends of every two adjacent release levers are jointed and fixedly connected to form a release connecting piece, the distal end of the release connecting piece comprises a joint, the release hole is located on the release connecting piece, and the central axes of the rest release holes do not penetrate through the joint and are located on one side close to the release head except that the central axes of the first release hole and the last release hole penetrate through the corresponding joint; the release holes and the release rings are in a penetrating structure, for any one of the release holes, on one side close to the release head, the release ring is arranged above, the release hole is arranged below, on one side far away from the release head, the release ring is arranged below, and the release hole is arranged above.

Preferably, the central axis of the release hole forms an angle b with a plane of the proximal end regions of two corresponding adjacent release levers, so that: 0 degrees < b <90 degrees, and the distance between the first release holes and the surface enclosed by the first support section is the largest.

Preferably, the release head comprises a release head part and a release head neck part, the maximum size of the release head part is at least the maximum size of the release head neck part or at least 4 times of the diameter of the release loop, and an angle γ formed by the central axis of the release head and the plane enclosed by the support rods in the proximal region of the first support section satisfies the following conditions: 5 DEG-gamma <90 DEG so that the release head is remote from and able to project beyond the first support section.

Preferably, the release head is of a conical or spherical configuration and is visible, the release head neck abutting or being adjacent to the first support section.

Preferably, the angle γ satisfies: gamma is more than or equal to 30 degrees and less than or equal to 60 degrees.

Preferably, a release extension rod is fixedly connected to the proximal end of the first release hole, an auxiliary release hole is formed in the proximal end of the release extension rod, the release rings penetrate through the auxiliary release hole end to end, the position of the release head relative to the auxiliary release hole is limited in the second state, and the auxiliary release hole is located between the first release hole and the inner wall surface of the middle support section.

Preferably, all of the outer surfaces of the release levers are wrapped with a winding body that is wound at the release link to form the release aperture.

Preferably, the winding body is formed with a reinforcing structure, and the reinforcing structure is positioned on the release lever, fixedly connects the release connecting piece, the release hole and the release lever and limits the relative position of the release hole on the release lever.

Preferably, the delivery system comprises an inner core assembly, a middle layer assembly and a catheter sheath assembly which can form mutual axial movement, the inner core assembly is detachably connected with the release head, the distal end region of the middle layer assembly is provided with a middle layer tube, and the release ring and the release head can enter and exit the middle layer tube.

Preferably, the stent also comprises a catching system, wherein the catching system comprises a snare, a catching inner sheath and a catching outer sheath, and the release holes, the release rings, the release heads, the snare and the catching inner sheath and/or the catching outer sheath are matched with each other, so that the stent can be caught and taken out of a body.

Preferably, the outer surfaces of the release ring and the release head are covered or coated with a biocompatible or anti-thrombotic coating.

By adopting the technical scheme, compared with the prior art, the utility model has the following technical effects:

1. the first support section comprises a controllable release mechanism, the controllable release mechanism comprises a release lever, a release hole, a release ring and a release head, the release hole comprises a first release hole and a tail release hole, the release lever is positioned at the near end of the first support section and fixedly connected with the support rod at a corresponding position, the release hole is fixedly arranged at the near end of the release lever, the release ring sequentially penetrates through the release hole to form a closed loop, the release ring is in sliding connection with at least one release hole, the release head is connected with the release ring, and the release head is detachably connected with the conveying system; the bracket is provided with a first form and a second form which can be mutually converted, the release head is pulled, all the release holes are mutually close and furled to drive the bracket to shrink, and finally the whole bracket is linearly loaded or pulled into the conveying system, so that the functions of pressing and holding the bracket and loading the bracket into the conveying system are realized; in the process of converting the first form into the second form, the second support section and the middle support section are successively restored to preset shapes, then the release rod of the first support section is restored to the preset shapes along with the relaxation of the release ring, and finally the stent is suitable for percutaneous transcatheter minimally invasive intervention implantation and realizes a controllable release function in the operation process.

2. The utility model provides that the first release hole is close to the release head and has the largest distance with the closed loop outline surrounded by the far ends of all the release levers, and the design is that: when the stent is loaded into the delivery system by pressing and holding, the first releasing hole firstly enters the delivery system and is closer to the operator relative to all releasing holes, on one hand, the problem that the releasing holes are squeezed together to the utmost extent, so that individual or most releasing holes are blocked outside the distal end surface of the delivery system, the successful loading into the delivery system is difficult, and the complete release of the stent is not ensured, and the capturing and the recovery are convenient is avoided, on the other hand, because the releasing holes or the releasing connecting pieces are surrounded by the largest outline in the circumferential direction by a larger area than the corresponding cross-sectional area of the releasing rods, or the sum of the cross-sectional areas of two adjacent releasing rods, all the releasing holes enter the delivery system in sequence, the process of converting the stent into the first form can be reduced, the resistance of the stent and the release holes thereof entering the delivery system (such as a sheath tube therein) improves the operation hand feeling of a surgeon, ensures stronger recoverability, and conversely, can also ensure that the safety of the release process of the stent system is higher in the process of converting the first form into the second form, and simultaneously reduces the inner diameter of the delivery system, particularly a delivery outer sheath, so as to reduce the requirement of the percutaneous transcatheter minimally invasive intervention implantation of the stent on the diameter of a vein (such as femoral vein and jugular vein) or an artery (such as femoral artery, carotid artery, radial artery and the like) of a patient, thereby expanding the application range of the stent system product to a certain extent.

3. The release holes provided by the utility model comprise the first release hole, the second release hole and the third release hole … … and the tail release hole, wherein the distances between the tail release holes of the first release hole, the second release hole and the third release hole … … and the central axis of the stent are respectively defined as L₁、L₂、L₂’、L₃、L₃’…… L_n-1、L_n-1’、L_nWherein L is₁、L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nThe mathematical relationship is satisfied: l is₁<L_n<L₂<L₃<……<L_n-1Or L₁<L₂<L₃<……<L_n-1<L_n，L₂＝L₂’， L₃＝L₃’……L_n-1＝L_n-1The centers of all the releasing holes are not on the same circle, and the design ensures that all the releasing holes sequentially enter the conveying system one by one in a certain sequence in the process of pressing, holding and loading the stent into the conveying system, so that the problem that individual or most releasing holes are clamped outside the far end surface of the conveying system and are difficult to be successfully loaded into the conveying system due to the fact that all the releasing holes are extruded together is fundamentally avoided, the stent can be pressed, held and loaded into the conveying system, the controllable releasing function is realized, and finally the stent is suitable for percutaneous transcatheter minimally invasive interventional implantation, and the ultrahigh safety of catching and recovering is also ensured after the stent is completely released.

4. The distance between the first release holes and the surface defined by the first support section is the largest, and the rest release holes are attached to the surface defined by the first support section, so that most or the whole release ring is attached to the surface defined by the bracket, and the design has the following advantages: a) the friction between the release ring and the first release hole is reduced, so that the first release hole and the release head can quickly and smoothly enter the conveying system, the loading performance of the whole stent is ensured, and the extremely high safety of catching and recovering after complete release is also facilitated; b) reducing the contact area of the stent, especially the first support segment, with the surface of the target area to minimize the irritation (and inflammatory response) caused by the stent to the target tissue or organ, especially the surface, and the severe requirement for the anatomical morphology of the target tissue area, expands the application scope of the stent system product, for example, when the stent is an interatrial pore-forming stent, the product can be applied to a population with a small interatrial surface area in the right atrium of the heart, especially a population with a close distance between the foramen ovale and the tricuspid valve annulus.

5. The number of the release holes is at least 4, the head and the tail of the release ring penetrate through the first release hole, so that in the second state, the position of the release head relative to the first release hole is limited, which is helpful for an operator to easily control the conveying system to realize the accurate positioning of the stent at a target position, and further enhance the controllable release performance of the stent system. Further, the tail release hole comprises a double-hole structure, the release rings are sequentially inserted into the double-hole structure, and the length size M of the hole cavity of the tail release hole_nAnd the outer diameter of the release ring itself is M₀Satisfies the following conditions: m₀<M_n≤3×M₀，0.08mm≤M₀The tail release holes are positioned at the far ends of the release rings and can be in interference fit with the release rings to play a role in fixing the release rings, so that the position of the release heads relative to the first release holes is fully ensured to be limited in the second state, the relative positions of the tail release holes and the release rings are always kept unchanged in the process that the stent is released to a target position through the delivery system after being sequentially pressed and loaded outside the body (the first state is converted into the second state) after being pressed and loaded into the delivery system, the release rods of the first support section are ensured to be restored to a preset shape along with the release rings, and the stent is fully unfolded after being completely released to the target position, and finally, the controllable release performance, operation safety and convenience of the operation are ensured.

6. The utility model is arranged on a plane perpendicular to the central axis m and passing through the release hole, the firstThe length of the cavity of the last release hole of one release hole, the second release hole and the third release hole … … is M₁、M₂、M₃……M_nWhen the release ring is linear, the outer diameter of the release ring itself is M₀Then M is₁、M₂、M₃……M_nThe mathematical relationship is satisfied: m₁>2×M₀，M₂>3×M₀， M₃>3×M₀……M_n-1>3×M₀，0.08mm≤M₀Less than or equal to 1mm, the design ensures that the release ring is arranged in the (n-1) th release holes of the second release holes and the third release holes … … to form low-damping sliding, so that the frictional resistance between the release ring and the release holes is sufficiently reduced, thereby not only further improving the functions of the stent which is pressed and loaded outside the body into the delivery system, but also further ensuring the controllable release property, the operation safety and the convenience of the operation, and further enhancing the safety of catching and recovering after complete release. Further, the central axes of the second release hole, the third release hole … … and the (n-1) th release hole do not pass through the corresponding junction and are located in the proximal region of the corresponding junction, the design enables the release ring to form nearly unimpeded sliding in the second release hole, the third release hole … … and the (n-1) th release hole, so that the resistance of the release ring in sliding in the release hole is reduced to the maximum extent, and the safety and smoothness of catching and recycling after complete release are further improved.

7. The stent system with the controllable release mechanism further comprises a capturing system, wherein the capturing system comprises a snare, a capturing inner sheath and a capturing outer sheath, and the stent can be placed in a lumen of the capturing outer sheath and recovered and taken out of a body through the mutual matching of the release hole, the release ring, the release head, the snare and the capturing inner sheath, so that the capturing and recovering of the stent under the conditions of unsatisfactory release effect or accidental dropping and the like are realized, and compared with similar products on the market, the stent provided by the utility model has higher safety and stronger recoverability.

Drawings

FIG. 1 is a schematic view of an embodiment of the present invention in which the release hole, the release mechanism and the bracket are an integrated structure, and all the release connecting members and the release holes are located outside the projection area of the first supporting section;

FIG. 2 is a schematic view of the release hole, release mechanism and stent being an integral structure, all of the release links and release holes being located within the projected area of the first support section in accordance with one embodiment of the present invention;

FIG. 3 is a top view of FIG. 2 showing only the first support section and the release mechanism, and the intermediate support section;

fig. 4a to 4c are partial views of fig. 3;

FIG. 4a is a front view of FIG. 3 showing only one release hole and its associated release ring;

FIG. 4b is a partial cross-sectional view of the release hole and release ring of FIG. 4 a;

FIG. 4c is a partial cross-sectional view of FIG. 3 showing only the first release hole, the auxiliary release hole and the release ring thereof;

FIG. 5 is a schematic view of a second embodiment of the first embodiment of the present invention, in which the support rod is a release lever, the release hole and the release connecting member are located on the edge of the first support frame, and the release head is located on the release ring;

FIG. 6 is a schematic view of a second embodiment of the first embodiment of the present invention, in which the support rod is a release lever, the release hole and the release connecting member are located at the edge of the first support frame, and the release head is located at the first release hole;

fig. 7a to 7b are partial views of fig. 6:

FIG. 7a is a cross-sectional view of the release head being tapered;

FIG. 7b is a cross-sectional view of the release head in the form of a sphere;

FIG. 8 is a schematic view of a release lever wrapped with a wrap according to a second embodiment of the present invention;

FIG. 9 is a schematic view of the release hole and release link of FIG. 8 in combination with a reinforcing structure on the release lever;

FIG. 10 is a schematic view of the stent having a controllable release mechanism according to the present invention, which is generally hollow and tubular;

FIG. 11 is a pre-assembled schematic view of a stent system incorporating a controlled release mechanism according to the present invention;

FIG. 12a is a partial view of the connection of FIG. 10, wherein the connection is a threaded connection;

FIG. 12b is a partial view of the connection of FIG. 10, wherein the connection is a ball detent connection;

FIG. 12c is a partial view of the connection of FIG. 12b in a disassembled state;

FIG. 13 is a schematic view of a stent system containing a controllable release mechanism according to the present invention released to a target tissue (atrial septum);

FIG. 14 is a schematic view of a stent system release head containing a controllable release mechanism of the present invention being captured by a snare and just entering a capture sheath;

FIG. 15 is a schematic view of a portion of a first support segment of a stent system incorporating a controllable release mechanism of the present invention being captured within a capture sheath;

FIG. 16 is a schematic view of the instant state in which the stent system including the controllable release mechanism of the present invention is fully captured within the capturing sheath;

wherein the reference numerals include: a stent system 1 comprising a controllable release mechanism; a bracket 2; a second support section 20; an intermediate support section 21; a support bar 210; an intermediate support section lumen 211; a first support section 22; a controllable release mechanism 23; a release lever 230; an adaptive structure 2300; a connection hole C2301; release the connection 2302; a junction 2303; a release hole 231; a first release hole 2310; a second release hole 2311; a third release hole 2312; a tail release hole 2313; a release ring 232; a release head 233; a release head 2330; release of the head and neck 2331; a winding body 234; a reinforcing structure 235; releasing the extension rod 236; an auxiliary release hole 237; a conveying system 3; an inner core assembly 30; a middle layer assembly 31; a catheter sheath assembly 32; pre-sheathing 320; a delivery sheath 321; a capture system 4; a snare 40; catching the inner sheath 41; capturing the outer sheath 42; the target tissue 5.

Detailed Description

The technical solution proposed by the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is provided solely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. In particular, different proportions are often used, as the drawing figures are to be distinguished.

To more clearly describe the stent system of the present invention having a controllable release mechanism, the terms "distal" and "proximal" are defined herein, which terms are conventional in the field of interventional medical devices. In particular, "proximal" refers to the end near the operator during the procedure, particularly when the stent is crimped loaded in the delivery system, and "distal" refers to the end away from the operator during the procedure, particularly when the stent is crimped loaded in the delivery system.

The utility model will be described in further detail below with reference to the drawings and a number of specific embodiments.

Example 1

A stent system 1 comprising a controllable release mechanism, comprising an elastic stent 2 and a delivery system 3 for delivering the stent 2 to a target site in a body; the support 2 is a frame surrounded by support rods 210, and specifically, the support 2 is a wavy or net-shaped structure formed by fixedly connecting a plurality of elastic support rods 210; the support comprises a first support section 22, a middle support section 21 and a second support section 20 from near to far in sequence, wherein the middle support section 21 is in a hollow tubular shape.

The stent 2 is a self-expanding structure, the first support segment 22 comprises a controllable release mechanism 23, the controllable release mechanism 23 comprises a release rod 230, a release hole 231, a release ring 232 and a release head 233, and the release hole 231 comprises a first release hole 2310 and a last release hole 2313.

The release lever 230 is located at the proximal end of the first support section 22 and is fixedly connected to the support rod 210 at a corresponding position, the release hole 231 is fixedly disposed at the proximal end of the release lever 230, the release ring 232 sequentially penetrates through the release hole 231 to form a closed loop, the release ring 232 and at least one of the release holes 231 form a sliding connection, the release head 233 is connected to the release ring 232, and the release head 233 is detachably connected to the delivery system 3.

The stent 2 has a first form and a second form which can be mutually converted, the release head 233 is pulled, all the release holes 231 are close to each other and are folded, the stent 2 is driven to shrink, and finally the whole stent 2 is linearly loaded or pulled into the conveying system 3, and the stent 2 is in the first form at this time, so that the functions of pressing and loading the stent 2 into the conveying system 3 are realized; in the process of transforming the first form into the second form, the second support section 20 and the intermediate support section 21 are restored to the preset shape in sequence, then the release lever 230 of the first support section 22 is restored to the preset shape along with the release ring 232 being loosened, and the fully-expanded state after being completely released to the target position is the second form of the stent 2, so that the stent 2 is finally suitable for percutaneous transcatheter minimally invasive interventional implantation, and the controllable release function is realized in the surgical process.

Preferably, the first release hole 2310 is closest to the release head 233 and is at the maximum distance from the closed loop profile defined by the distal ends of all the release levers 230, and the design is such that: when the stent 2 is loaded into the delivery system 3 by pressing, the first release holes 2310 firstly enter the delivery system 3 and are closer to the operator relative to all the release holes 231, on one hand, the problem that the release holes 231 are crowded together to the utmost extent and cause the individual or most of the release holes 231 to be blocked outside the distal end of the delivery system 3, the successful loading into the delivery system 3 is difficult, and the problem that the complete release of the stent 2 is not ensured and the capture and recovery are convenient occurs is solved, on the other hand, because the maximum contour of the release holes 231 or the release connectors 2302 in the circumferential direction is far larger than the cross-sectional area of the corresponding release bars 230 or the sum of the cross-sectional areas of two adjacent release bars 230, all the release holes 231 enter the delivery system 3 in a certain sequential order, the resistance of the stent 2 and the release holes 231 thereof entering the delivery system 3 (such as a sheath therein) during the process of converting the stent 2 into the first form can be reduced, the operation hand feeling of the operator can be improved, and the stronger recyclability can be ensured, and conversely, the safety of the release process of the stent system can be higher during the process of converting the first form into the second form, and simultaneously, the inner diameter of the delivery system 3, particularly the delivery sheath 321, can be reduced, so that the requirement of the percutaneous transcatheter minimally invasive interventional implantation of the stent 2 on the approach of the patient, particularly the diameter of the blood vessels of veins (such as femoral vein and jugular vein) or arteries (such as femoral artery, carotid artery, radial artery and the like) can be reduced, and the application range of the stent system product can be expanded to a certain extent.

In one embodiment, the release holes include the first release hole, the second release hole, the third release hole … … and the distal release hole, the distance between the first release hole and the central axis of the stent is the smallest, and the distance between the distal release hole and the central axis of the stent is respectively defined as L, L₁、L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nWherein L is₁、 L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nThe mathematical relationship is satisfied: l is₁<L_n<L₂<L₃<…… <L_n-1Or L₁<L₂<L₃<……<L_n-1<L_n，L₂＝L₂’，L₃＝L₃’……L_n-1＝L_n-1', the centers of all the release holes are not on the same circle, which has the following advantages: 1) the distance between the first release hole 2310 and the central axis of the bracket 2 is minimized, so that the release head 233 is closer to the central position of the bracket 2 whenDuring the press-and-hold loading of the stent 2 into the delivery system 3, the release holes 231, the first release holes 2310 enter the delivery system 3 first and closer to the surgeon, a) all the release holes 231 can enter the delivery system 3 one by one in a certain sequential order, thus fundamentally avoiding that all the release holes 231 get jammed together, resulting in individual or most of the release holes 231 getting stuck out of the distal end of the delivery system 3, and being difficult to load into the delivery system 3 successfully, further ensuring that the stent 2 can be pressed, held and loaded into the conveying system 3 to realize the controllable release function, finally ensuring that the stent 2 is suitable for percutaneous transcatheter minimally invasive intervention implantation, and also ensuring the ultrahigh safety of facilitating capture and recovery after the stent 2 is completely released; b) since the maximum contour of the release holes 231 or the release connection members 2302 in the circumferential direction is much larger than the sum of the cross-sectional areas of the two adjacent release levers 230, all the release holes 231 enter the delivery system 3 sequentially in a certain sequence, the resistance of the stent 2 and the release holes 231 entering the delivery system 3 (such as a sheath therein) during the process of the stent 2 transforming from the second configuration to the first configuration can be reduced, the operation hand feeling of the operator is improved, and the recyclability is ensured; c) the safety of the release process of the stent system is higher in the process of converting the first form into the second form; 2) the inner diameter of the delivery system 3, particularly the delivery sheath 321, is reduced, so that the requirement of the percutaneous transcatheter minimally invasive intervention implantation of the stent 2 on the diameter of the access of a patient, particularly the diameter of a vein or an artery vessel, is reduced, and the application range of the product is expanded to a certain extent.

In one embodiment, the first release holes 2310 are spaced the greatest distance from the surface enclosed by the first support section 22, and the remaining release holes 231 fit the surface enclosed by the first support section 22, so that most or all of the release rings 232 fit the surface enclosed by the stent 2, which has the following advantages: a) the friction between the release ring 232 and the first release hole 2310 is reduced, so that the first release hole 2310 and the release head 233 can enter the conveying system 3 quickly and smoothly, the loading performance of the whole stent 2 is ensured, and the high safety of capturing and recovering after complete release is facilitated; b) reducing the contact area of the stent 2, particularly the first support segment 22, with the surface of the target site area to a certain extent, minimizing the irritation (and inflammatory reaction) caused by the stent 2 to the target tissue 5 or organ, particularly the surface, and the strict requirement on the anatomical morphology of the target tissue 5 area, and expanding the applicable population of the stent system, for example, when the stent 2 is an interatrial pore-forming stent 2, the product can be applied to a population with a small interatrial surface area in the right atrium of the heart, particularly a population with a close distance between the foramen ovale and the annulus of the tricuspid valve; c) the space occupied by the first support section 22 in the right atrium is reduced to a certain extent, the operation space is increased during the implantation of the stent system, and the influence on the cardiac hemodynamics is reduced;

in one embodiment, the present invention provides that the number of the release holes 231 is at least 4, the release ring 232 passes through the first release hole 2310, end to end, such that in the second state, the position of said release head 233 relative to said first release aperture 2310 is defined, this facilitates easy manipulation of the delivery system 3 by the surgeon to achieve precise positioning of the stent 2 at the target site, thereby enhancing the controlled release of the stent system of the present invention, which, of course, to a certain extent, continuous blood flow impinging on the stent 2, in particular the controllable release mechanism 23, is avoided, resulting in a continuous relative movement, eventually resulting in a slow progression of endothelialization of the controllable release mechanism 23, or the release ring 232 and the release hole 231 may rub against each other, which may cause fatigue fracture of the controllable release mechanism 23. Further, when the number of the release holes 231 is even, the tail release hole 2313 includes a double-hole structure, and the release ring 232 sequentially penetrates through the double-hole structure, as shown in fig. 1, fig. 2, fig. 3, fig. 5, and fig. 6, so as to ensure that the head and the tail of the release ring 232 can penetrate out of the first release hole 2310 from bottom to top, thereby facilitating the realization of the release by means of the release head 233Controlled release of the stent 2 and subsequent capture recovery as mentioned. A cavity length dimension M of the tail release hole 2313_nAnd the outer diameter M of the release ring 232 itself₀Satisfies the following conditions: m₀ <M_n≤3×M₀，0.08mm≤M₀No more than 1mm, the tail release holes 2313 are located at the distal end of the release ring 232, and can be in interference fit with the release ring 232 to play a role of fixing the release ring 232, which not only sufficiently ensures that the position of the release head 233 relative to the first release hole 2310 is defined in the second state, but also ensures that the relative positions of the tail release holes 2313 and the release ring 232 are always kept unchanged in the process of releasing the stent 2 to the target position through the delivery system 3 after being successively pressed and loaded into the delivery system 3 in vitro (the first state is converted into the second state), thereby ensuring that the release levers 230 of the first support sections 22 can be restored to the preset shapes along with the release ring 232 being loosened, and the stent 2 is in a sufficiently unfolded state after being completely released to the target position, and finally ensuring the controllable release performance of the operation, Safety and convenience of operation.

In one embodiment, the first release hole 2310, the second release hole 2311, the third release hole 2312 … … and the last release hole 2313 have a bore length dimension M, respectively, in a plane perpendicular to the central axis M and passing through the release hole 231₁、M₂、M₃……M_nWhen the release ring 232 is linear, the outer diameter of the release ring 232 itself is M₀Then M is₁、M₂、M₃……M_nThe mathematical relationship is satisfied: m₁>2×M₀，M₂>3×M₀，M₃>3×M₀……M_n-1>3×M₀，0.08mm ≤M₀Less than or equal to 1mm, the design is that the release ring 232 is arranged to form low-damping sliding in the n-1 th release holes of the second release hole 2311 and the third release hole 2312 … …, the frictional resistance between the release ring 232 and the release holes 231 is sufficiently reduced, and therefore, the external pressure holding and loading of the stent 2 in the body is further improvedThe function of the system 3 further ensures the controllable release, operation safety and convenience of the operation, and further enhances the safety of catching and recovering after complete release. Further, the central axes of the second release hole 2311 and the n-1 th release hole 2312 … … do not pass through the corresponding intersection points 2303 and are located at a side close to the release head 233, which enables the release ring 232 to slide in the n-1 th release hole 2311 and the third release hole 2312 … … without obstruction, so as to reduce the resistance of the release ring 232 to slide in the release hole 231 to the maximum, and further enhance the safety and smoothness of catching and recovering after complete release.

The diameter of the first release hole 2310 is as large as the size of the release connector 2302 allows, so as to ensure that the two ends of the release ring 232 can slide smoothly in the first release hole 2310, but not exceed the size of the release head 233, so as to ensure that the release head 233 protrudes from the outer surface of the controllable release mechanism 23 and the release head 233 completely abuts against the first release hole 2310.

Preferably, the release holes 231 and the release rings 232 are inserted, and for any one of the release holes 231, on the side close to the release head 233, the release ring 232 is on top, the release hole 231 is on bottom, on the side far from the release head 233, the release ring 232 is on bottom, and the release hole 231 is on top.

In one embodiment, the stent 2 containing the controllable release mechanism provided by the present invention has a hollow tubular shape, the shape of the hollow tubular shape includes a cylindrical shape with a constant diameter and a straight tube, such as a cylindrical shape with a constant diameter and a curved bow shape, and a tapered cone shape or a truncated cone shape with a gradually changing size, as shown in fig. 10, the stent 2 can be adapted to various artery or venous blood vessel lumens, and can be used for supporting various large and small blood vessels, such as coronary artery (coronary artery stent), peripheral popliteal artery (popliteal artery stent) and below-knee artery (below-knee artery stent), intracranial artery (intracranial artery covered stent), jugular vein (jugular vein stent), treating stenosis or blockage of blood vessels, and also can be used for isolating or plugging true aneurysm or pseudo aneurysm (such as abdominal aorta covered stent) formed by dissection or enlargement of peripheral blood vessels (thoracic aorta covered stent), the device can be used for preventing blood vessel rupture, filtering or storing fragments such as artery and vein thrombosis or calcification, for example, a vein thrombosis filter, an artery thrombosis protector, and the like, and preventing blood vessel blockage for supplying blood to important organs of human body.

In another embodiment, the stent 2 has an overall h-shape, and the stent 2 is an atrial septal foramen stent 2 (i.e., an atrial shunt), and specifically, the stent 2 comprises a first support segment 22 attached to an interatrial septum surface in a right atrial chamber, a second support segment 20 attached to an interatrial septum surface in a left atrial chamber, and an intermediate support segment 21 disposed between the first support segment 22 and the second support segment 20 and fixedly connecting the first support segment 22 and the second support segment 20. The design that a tangent plane alpha exists on the edge area of the first support section 22, the tangent plane alpha is perpendicular to the central axis m of the stent 2, a tangent plane beta exists on the edge area of the second support section 20, and the tangent plane beta is perpendicular to the central axis m of the stent 2 can remarkably enhance the fitting performance of the edge area of the second support section 20 and the edge area of the first support section 22 with the target tissue 5, and reduce the stimulation or damage of the edge area of the second support section 20 and the edge area of the first support section 22 to the target tissue 5 to a certain extent. The middle support section 21 is hollow and tubular as a whole, and the inner cavity of the middle support section 21 enables the left atrium and the right atrium to be in fluid communication, so that shunting of the left atrium and the right atrium is realized.

The stent system for establishing atrial shunts following atrial septal foramina is further described and illustrated below.

In this embodiment, the release lever 230 and the release hole 231 of various embodiments are disposed on the first support section 22, and the release hole 231, the controllable release mechanism 23 and the stent 2 are an integrated structure formed by laser engraving and heat setting the same shape memory alloy tube.

In the first embodiment, the number of the release levers 230 is even and half of the number of the support levers 210 on the first support section 22. The distal ends of the release levers 230 are fixedly connected to the distal ends of the support rods 210 of the first support section 22, the proximal ends of every two adjacent release levers 230 are connected and fixed to each other to form a release connection member 2302, the point where the proximal ends of every two adjacent release levers 230 are connected defines a connection point 2303, and all the release holes 231 are located on the release connection member 2302. On the plane α or the plane β, all the release links 2302 and the release holes 231 are located within the projected area of the first support section 22, as shown in fig. 2. This design has the following advantages:

a) the release holes 231 are located in the area covered by the first support section 22, that is, the area of the circle surrounded by all the release holes 231 is smaller than the area covered by the first support section 22, and the release ring 232 is located outside the lumen surrounded by the middle support section 21, so that the flow dividing effect of the lumen surrounded by the middle support section 21 is not affected;

b) reducing the diameter of the circle enclosed by the distal ends of all of the drawbars detachably connected to the release link 2302 in the prior art, namely: the space occupied by the traction rod in the right atrium is reduced to a certain extent, the operation space is increased in the process of implanting the bracket system, and meanwhile, the influence on the cardiac hemodynamics is reduced;

c) compared with the prior art, the number of the release rods 230 is reduced, so that the number of the release rods 230 is half of that of the support rods 210 on the first support section 22, the pulling process of the stent system is easier to control, and the physician can fully judge whether the stent system is safely fixed (straddled) on the interatrial target tissue 5 through a pulling test.

In addition, the release lever 230 is provided with an adaptive structure 2300, the adaptive structure 2300 is located at the connection region of the release lever 230 and the support rod 210 of the first support section 22, the adaptive structure 2300 is radially outward from the edge of the first support section 22, then the adaptive structure 2300 is bent to obliquely span the edge of the first support section 22 and extend towards the center of the support frame (fig. 2), and the bending angle θ of the adaptive structure 2300 satisfies: 90 DEG-175 DEG, or from the edge of the first support section 22 radially outward and then curves in a plane alpha extending away from the support frame (FIG. 1), the angle of curvature theta of the adaptive structure 2300 being such that: 10 DEG-135 DEG, wherein the bending angle theta is an angle formed by a radially outward direction of the edge face of the first support section 22 and an outward direction of a tangent to the proximal end of the release lever 230.

Preferably, the adaptive structure 2300 extends radially outwards from the edge of the first support section 22 and then obliquely crosses the edge of the first support section 22 in a curved shape and extends towards the center of the support frame, and the bending angle θ of the adaptive structure 2300 satisfies: theta is more than or equal to 90 degrees and less than or equal to 175 degrees. This adaptive structure 2300 has the following advantages:

a) the stent has a larger curve arc shape and tends to be in a gentle state, so that the contact area of the stent 2 and the target tissue 5 is greatly increased, the stimulation and damage of the stent 2 to the target tissue 5 are reduced to the greatest extent, and the stimulation and inflammatory response to the tissue and the physical damage to the tissue caused by stress concentration and other mechanisms are avoided;

b) the adaptive structure 2300 as described above further has the characteristic of being attached to the outer surface of the first support section 22 and being non-obtrusive relative to the first support section 22, thereby reducing the space occupied in the right atrium and greatly reducing the impact on the hemodynamics; at the same time, the probability of thrombosis on the stent 2 is reduced;

c) the adaptive structure 2300 has a much smaller cross-sectional area and a much higher elastic deformability than all the support rods 210 in the edge area of the first support segment 22, wherein the cross-sectional area of the adaptive structure 2300 is not more than half of the cross-sectional area of all the support rods 210, I) not only allows all the adaptive structures 2300 to have a certain degree of radial expansion and contraction adjustment function, thus being adaptable to a smaller atrial septal surface area, expanding the adaptive population of the stent system in the present invention, especially asian population, and minors population; of course, the effects on the atrial septum adjacent tissue, such as the tricuspid valve, may also be minimized or controlled; II) the adaptive structure 2300 is also enabled to have a certain degree of elastic deformability in the axial direction, so that the adaptive structure can adapt to uneven tissues possibly existing in the right atrial side area of the interatrial septum, the tissue fitting performance is remarkably improved, and the stimulation and damage of the stent 2 to the target tissue 5 are reduced, so that the adaptive structure has wide anatomical form adaptability;

d) although the release rod 230 has an adaptive structure 2300, the pressure transmissibility of the stent 2 in the whole process of being pressed and held in the delivery sheath to be pushed and guided to a target position and the tension transmissibility of the stent 2 in the process of being recovered or caught into the delivery sheath after being partially or completely released are not lost, so that the stent system has ultrahigh maneuverability in the process of surgical introduction and recovery or catching, and compared with the traditional atrial septal defect occluder, the surgical mode has nearly the same surgical mode and surgical steps, so the learning curve (period) of the product is short, and the application popularization is fast; in order to prevent the pressure transmissibility from being lost, the curve length of the adaptive structure 2300 is 1-15 mm, and preferably, the length of the adaptive structure 2300 is 2-5 mm;

e) the adaptive structure 2300 obliquely spans the edge of the first support section 22 and extends towards the center of the stent 2, so that the release lever 230 is close to the proximal end and the central region, and the release connector 2302 is always positioned outside the proximal end of the first support section 22, so that the surgeon can utilize the release head 233 and the release ring 232 to cooperate with the snare 40 and the capture sheath to perform the recaptured sheathing function on the stent 2 after capturing, without attempting to tighten the release ring 232, possibly causing the edge of the support rod 210 of the first support section 22 to be directly radially contracted and to be pressed down on the periphery of the intermediate support section 21, causing the support rod 210, especially the edge, of the first support section 22 to partially or completely overlap the support rod 210 of the intermediate support section 21, and further causing a ring-shaped bulge to be formed at the connecting transition region of the intermediate support section 21 and the first support section 22, due to the fact that the outer diameter of the annular bulge is large and may exceed 20mm, the stent system cannot be finally recovered from the capturing sheath used in the following conventional surgery, and therefore, when the stent system is completely released to the interatrial septum target tissue 5, if instrument displacement occurs or the effectiveness of pore creation is insufficient, and possibly due to improper operation of an operator, the instrument falls to other positions from the interatrial septum tissue, such as the right atrium, the right ventricle, the pulmonary artery and the like, the design of the adaptive structure 2300 enables the operator to timely develop emergency remedial measures, facilitates the capturing and recovering functions, safely and quickly captures and recovers the stent 2 into the sheath until the outside of the patient, and finally ensures that the surgery has very high safety.

Preferably, the central axis of the release hole 231 forms an included angle b with a plane where the proximal end regions of two adjacent release levers 230 are located, where the included angle b satisfies: 0 degrees < b <90 degrees, so that the release holes 231 can be attached to the surface enclosed by the first support section 22 to the maximum extent.

In a second embodiment, the release rod 230 is a shape memory alloy thin rod, and the support rod 210 at the edge of the first support section 22 is the release rod 230, as shown in fig. 5 and 6. All the release levers 230 and the support frame are of an integrated structure formed by laser engraving and heat setting the same shape memory alloy tube, and the release holes 231 are located in the edge area of the release levers 230. All the releasing links 2302 and the releasing holes 231 are located at the edges of the first supporting section 22 on the plane α and the plane β, but the centers of all the releasing holes 231 are not located on the same circle, which is simple in structure and easy to manufacture, and can achieve the beneficial effect close to the first embodiment.

Preferably, the release heads 233 are located at the first release holes 2310, and the release rings 232 pass through the first release holes 2310 end to end, so that the position of the release heads 233 relative to the first release holes 2310 is defined in the second state.

In one embodiment, a release extension rod 236 is further fixedly connected to a proximal end of the first release hole 2310, and an auxiliary release hole 237 is disposed at a proximal end of the release extension rod 236. The release extension rod 236, the auxiliary release hole 237 and the stent 2 are of an integrated structure formed by laser engraving and heat setting of the same shape memory alloy tube, and the release ring 232 is of a closed loop structure formed by heat setting of a shape memory alloy wire; the release rings 232 all penetrate through the auxiliary release holes 237 end to end, the auxiliary release holes 237 are located between the first release holes 2310 and the inner wall surface of the intermediate support section 21, as shown in fig. 4c, in the second state, the positions of the release heads 233 relative to the auxiliary release holes 237 are limited, and the design can reduce the distance from the release heads 233 to the central axis of the stent 2, so that the release heads 233 are closer to the central area of the proximal end of the stent 2, the loading and sheath collection of the stent 2 are facilitated, and the safety of the operation process is improved.

For the release ring 232, the release ring 232 sequentially penetrates all the release holes 231 in an up-down penetrating manner, and two ends of the release ring 232 are gathered at the release head 233, as shown in fig. 5 and 6, and are placed in the release head 233 by means of screw extrusion, knotting, heat bonding, gluing, etc. to form a closed loop structure, so that the release head 233 is attached to the release holes 231 and protrudes out of the outer surface of the first support section 22.

In one embodiment, the release ring 232 is made of a flexible material, and in a natural state, the shape enclosed by the release ring 232 is the same as or close to the shape of the polygon enclosed by the release holes 231, so that the release ring 232 is in a tight state, and the release heads 233 at the two ends of the release ring 232 are fixed relative to the position of the release ring 232 and abut against and protrude from the outer surface of the release mechanism or the first support section 22.

In another embodiment, the release ring 232 is formed from a single metal wire having elasticity or shape memory or torsion resistance, and is formed into a ring shape by joining the metal wire end to end, and the diameter of the metal wire is preferably controlled to be smooth in sliding the metal wire through the release hole 231

And

in the meantime. When the release ring 232 is visible, if a shape memory alloy wire is selected, an operator can judge the position and the state of the stent 2 through images, so that the release and recovery operations of the stent 2 are realized; in a natural state, two end regions of the release ring 232 are gathered and shaped and located at the edge of the release mechanism or the first support section 22, preferably, two end regions of the release ring 232 are located at the release hole 231, so that the release head 233 abuts against the release hole 231 and protrudes out of the outer surface of the release mechanism or the first support section 22.

The release rings 232 sequentially penetrate through all the release holes 231 in an up-and-down penetrating manner to form a closed loop structure, the shape of the closed loop is preferably circular, so that the area surrounded by the release rings 232 is not smaller than the polygonal area surrounded by the passed release holes 231, and the closed loop is located in the area covered by the first support section 22, and when the number of the release holes 231 is as small as 4, the shape of the closed loop line may be quadrilateral, so that part of the line segment of the closed loop line is located in the area covered by the middle support section inner cavity 211, the shunting effect is influenced to a certain extent, and the risk of forming thrombus on the surface of the stent 2 is increased. Preferably, the release rings 232 passing through every two adjacent release holes 231 form a circular arc or a V-shaped wave with a two-dimensional plane or a three-dimensional solid, and the design enables the release rings 232 to bypass the projection area of the intermediate support section 21 on the plane α without affecting the flow distribution effect of the stent 2.

Further preferably, an arc transition structure is arranged in the wave point area of the V-shaped wave, and generally, the arc transition structure has an arc radius of 1-15 mm, and the design does not affect the relative sliding of the release lever 230 and the release hole, so that the releasing and unfolding processes of the first support section 22 and the capturing and recovering processes of the stent 2 are not affected.

Preferably, the outer surfaces of the release ring 232 and the release head 233 are provided with a coating, such as parylene, titanium nitride, mucopolysaccharidosis, ceramic, polyethylene terephthalate, expanded polytetrafluoroethylene, polyurethane, heparin, by coating or magnetron sputtering, to cover the outer surfaces of the release ring 232 and the release head 233. The thickness of the coating is 0.05-10 mu m, the adhesion force of the coating attached to the surface of the metal material can be effectively enhanced, the surface of the metal material implanted into a human body for a long time can be modified to improve the corrosion resistance of the metal material, and the risk of thrombosis is reduced.

Preferably, the release head 233 is visible to facilitate rapid identification and location of the connection of the release head 233 to the release lever 230 via an imaging device, such as an ultrasound, X-ray device.

Preferably, the release head 233 is a cone or a sphere, as shown in fig. 7a and 7b, structurally, the release head 233 comprises a release head portion 2330 and a release head neck 2331, the release head neck 2331 abuts against or is close to the first support section 22, the maximum size of the release head portion 2330 is at least the maximum size of the release head neck 2331 or at least 4 times the diameter of the release ring 232, and the release head portion 2330 is far away from and can protrude out of the first support section 22. In addition, the central axis of the release head 233 and the support rod 210 in the proximal region of the first support section 22 form an angle γ, and the included angle γ satisfies γ being not less than 5 degrees and less than 90 degrees, so that the design can give consideration to the recovery convenience and reduce the risk of thrombosis through multiple tests of simulating clinical environments. More preferably, the angle γ should satisfy 30 ° ≦ γ ≦ 60 ° so that the subsequently mentioned snare 40 can quickly catch onto the release neck 2331 and retrieve the stent 2 into the catching outer sheath 42 by interacting with the subsequently mentioned catching inner sheath 41 and catching outer sheath 42.

Preferably, the distal end of the release head-neck 2331 is provided with a stepped hole, which is reduced in size from the proximal to the distal, and which can accommodate the tip of the release lever 230; the size of the tip of the release lever 230 is larger than the minimum aperture size of the stepped hole, so as to achieve a limit connection of the release lever 230 with the release head 233. Further, the smallest aperture of the stepped hole can simultaneously pass through two ends of the release lever 230, so that during the catching of the release head 233 by the mentioned snare 40, the end of the release lever 230, especially the portion outside the release head 233 and adjacent to the release head 233, can play the role of the neck, so as to facilitate the catching of the snare 40 and firmly sleeve the release head 233, thereby avoiding the slippage between the snare 40 and the stent 2 during the catching process, which leads to the falling-off of the stent 2.

Preferably, the release head 2330 and the release head 2331 can be fixedly connected by a screw connection, an adhesive connection, a welding or a mechanical clamping. Further preferably, the proximal end of the release head and neck portion 2331 is provided with an internal thread, the distal end of the release head portion 2330 is provided with an external thread, through the matching connection between the threads, not only the fixed connection between the release head and neck portion 2331 and the release head portion 2330 can be realized, but also the internal space between the proximal end of the release head and neck portion 2331 and the distal end of the release head and head portion 2330 can be limited, and the two end portions of the release lever 230 are completely placed inside the release head 233 by a thread pressing manner, so that the positions of the two end portions of the release lever 230 inside the release head 233 are not affected by the release process and the recovery operation, and are always placed inside the release head 233 and are not contacted with blood, thereby reducing the risk of thrombus formation; the delivery system 3 at least comprises a core assembly 30, and the proximal end of the release head 2330 is provided with an internal thread, and the proximal end of the internal thread is detachably connected with the distal end of the core assembly 30 of the delivery system 3 through a thread.

Example 2

Based on example 1, example 2 differs from the first embodiment of example 1 in that: the release hole 231 is combined with the release link 2302, the release lever 230 is wrapped with a winding body 234 on the entire outer surface, as shown in fig. 8, the release hole 231 is formed by winding the winding body 234 around the release link 2302, and the release hole 231 has flexibility and stretch resistance. The release ring 232 sequentially penetrates through all the release holes 231 in an up-and-down penetrating manner, and two ends of the release ring 232 are gathered at the release head 233 and are arranged in the release head 233 through screw extrusion, knotting, hot bonding, cementing and the like, so that a closed loop structure is formed. The release head 233 can protrude from the outer surface of the release mechanism and is detachably connected to the delivery system 3.

Preferably, the release lever 230 is provided with a connecting hole C2301, and further, the connecting hole C2301 is located inside the release lever 230, so that both ends of the winding body 234 can respectively pass through the connecting holes C2301 and wind around the release lever 230, and completely wrap the release lever 230. This design has the following advantages:

a) the connecting holes C2301 can fix both ends of the winding body 234, and prevent the winding body 234 from slipping during the loading and retrieving process of the bracket 2;

b) the winding body 234 completely wraps the release rod 230, so that the surface area of metal in the product, which is in direct contact with blood, is reduced, and the risk of complications such as thrombosis on the surface of the product is reduced;

c) the winding body 234 is preferably made of a material with a lower friction coefficient than that of the release rod 230, such as polytetrafluoroethylene, expanded polytetrafluoroethylene, fluorinated ethylene propylene, which not only can reduce the friction resistance of the stent 2 in and out of the delivery system 3 and the catching outer sheath 42 mentioned later during the installation or release process, improve the handling feeling and ensure the controllability of installation and release, but also can facilitate the tissue growth and endothelial coating on the release rod 230 after the stent 2 is released on the target tissue 5 when a material with a porous structure is used as the winding body 234, shorten the endothelialization time and enhance the fixation safety of the stent 2.

Preferably, the winding body 234 is formed with a reinforcing structure 235, as shown in fig. 9, the reinforcing structure 235 is located on the release lever 230, and the release connector 2302, the release hole 231 and the release lever 230 are fixedly connected to each other, so as to prevent the winding body 234 from sliding on the release lever 230 under an external force, ensure the size of the release hole 231 is stable, and limit the relative position of the release hole 231 on the release lever 230.

Example 3

Based on example 1, example 3 differs from example 1 in that: the delivery system 3 includes at least an inner core assembly 30, a middle layer assembly 31 and an introducer sheath assembly 32 that are configured for axial movement relative to one another. The inner core assembly 30 can move axially in the lumen of the middle layer assembly 31, and the distal end of the inner core assembly 30 is detachably connected to the release head 233. Specifically, the proximal end of the release head 2330 is provided with an internal thread, and the proximal end of the internal thread is detachably connected to the distal end of the inner core assembly 30 through a thread (shown in fig. 12 a), or the release head 233 is detachably connected to the distal end of the inner core assembly 30 through a ball detent (shown in fig. 12b and 12 c). The distal region of the mid-level assembly 31 is provided with a mid-level tube into and out of which the release ring 232 and the release head 233 can pass. The catheter sheath assembly 32 includes a pre-loaded sheath 320 and a delivery outer sheath 321. In this embodiment, the releasing and recovering process of the delivery system 3 and the stent 2 is simpler and safer, and the specific implementation process is as follows:

the support 2 and the inner core assembly 30 are pre-assembled in vitro, and the pre-assembly process is as follows:

a) firstly, the support 2 is detachably connected with the far end of the inner core assembly 30 through thread matching, then the near-end handle of the inner core assembly 30 is withdrawn, the end parts of the release head 233 and the release ring 232 and the part of the release ring 232 adjacent to the release head 233 are retracted into the middle layer assembly 31, and the relative fixation of the positions of the middle layer assembly 31 and the inner core assembly 30 is realized through a locking device of the near-end handle of the middle layer assembly 31;

b) further retraction of the inner core assembly 30 loads the stent 2, including the first support section 22, the intermediate support section 21, and the second support section 20, fully compressed into the pre-sheathing 320, as shown in fig. 11.

Then, the pre-assembled stent system is used with the delivery sheath 321 to complete the implantation of the stent 2, as follows:

a) after a channel is established in the body, the distal end of the delivery sheath 321 is positioned at the interatrial septum target site. At this point, the pre-assembled sheath 320 is inserted distally into the proximal end of the delivery outer sheath 321, and the middle assembly 31 is slowly pushed distally to introduce the stent system into the delivery outer sheath 321;

b) the position of the delivery sheath 321 remains unchanged, and the middle assembly 31 is slowly pushed distally until the second support section 20 of the stent 2 is pushed out of the distal end of the delivery sheath 321 and fully deployed;

c) slowly withdrawing the delivery sheath 321 proximally so that the second support section 20 can abut the target tissue 5 on the left atrial side of the interatrial septum;

d) after the second support section 20 is fully engaged with the target tissue 5, the delivery sheath 321 is continuously withdrawn proximally, such that the middle support section 21 and the first support section 22 are located outside the delivery sheath 321 and tend to be in an extended state, fully engaged or partially engaged with the corresponding target tissue 5;

e) an operator judges whether the position of the stent 2 is ideal through images, if so, the handle of the inner core assembly 30 controls the far end of the inner core assembly 30 and the detachable structure of the release head 233 on the stent 2 to release the stent 2, and the stent 2 after being completely released is completely attached to the interatrial septum target tissue 5, as shown in fig. 13. When the placement position is not ideal, the stent 2 is completely placed in the delivery sheath 321 by slowly pushing the delivery sheath 321 towards the far end, so that the recovery of the stent 2 is realized; subsequently, the stent 2 is implanted into the target tissue 5 by the second adjustment.

Example 4

Example 4 differs from example 3 in that, based on example 3: the stent system 1 comprising the controllable release mechanism 23 comprises a capturing system 4, the capturing system 4 comprising a snare 40, a capturing inner sheath 41 and a capturing outer sheath 42. The release head 233 protruding from the stent 2 can be placed in the catching inner sheath 41 by the mutual cooperation of the release hole 231, the release ring 232, the release head 233, the snare 40 and the catching inner sheath 41. Further, by using the catching outer sheath 42 in a matching manner, the snare 40, the catching inner sheath 41 and the stent 2 can be placed in the lumen of the catching outer sheath 42 and recovered and taken out to the outside of the body, so that the catching and recovery of the stent 2 under the conditions of non-ideal release effect or accidental dropping and the like are realized, and therefore, compared with similar products in the market, the stent 2 disclosed by the utility model is higher in safety and higher in recoverability. Preferably, the catching inner sheath 41 is 6Fr in specification, and the catching outer sheath 42 is 8-24 Fr in specification. More preferably, the specifications of the catching sheath 42 adapted to the stent 2 of the present invention are recommended to be 10Fr, 12Fr, 14 Fr.

When the stent 2 is completely released in vivo, the image shows that the implantation position of the stent 2 is not ideal, and particularly, when the stent 2 falls to the emergency such as the left atrium, the right ventricle and the valve orifice, the stent 2 needs to be captured and recovered in an emergency, and the specific process is as follows:

a) when the release ring 232 and the release tip 233 are made of a developing material, the release ring 232 and the release tip 233 have visibility, so that an operator can judge the position and state of the stent 2 by an image, and with the aid of the image, the release tip 233 is firmly grasped by the snare 40 and the proximal end of the snare 40 is locked with the capturing inner sheath 41, as shown in fig. 14;

b) keeping the position of the delivery sheath 321 or the capture sheath 42 unchanged, slowly withdrawing the snare 40 proximally, retracting the release head 233 and the distal end of the snare 40 to the distal end of the delivery sheath 321 or the capture sheath 42, and continuing to slowly withdraw the snare 40, so that the stent 2 is entirely withdrawn into the delivery sheath 321 or the capture sheath 42, as shown in fig. 15;

c) the snare 40 and the stent 2 are withdrawn outside the body by withdrawing the delivery sheath 321 or the catching sheath 42, as shown in fig. 16, thereby completely releasing or accidentally falling off the function of facilitating the catching recovery, thus ensuring higher safety and recyclability during and after the operation.

The embodiments of the present invention have been described in detail, but the embodiments are merely examples, and the present invention is not limited to the embodiments described above. Any equivalent modifications and substitutions to those skilled in the art are also within the scope of the present invention. Accordingly, equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered by the present invention.

Claims

1. A stent system containing a controllable release mechanism comprises an elastic stent and a delivery system for delivering the stent to a target position in a body, wherein the stent is surrounded by support rods to form a frame, the stent comprises a first support section, a middle support section and a second support section, and is characterized in that,

2. The bracket system of claim 1, wherein the first release aperture is proximate the release head and is a maximum distance from a closed loop profile defined by distal ends of all of the release levers.

3. The stent system of claim 2, wherein the release holes comprise the first release hole, the second release hole and the third release hole … …, the first release hole has a minimum distance from the central axis of the stent, and the first release hole, the second release hole and the third release hole … … have a distance from the central axis of the stent defined as L₁、L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nWherein L is₁、L₂、L₂’、L₃、L₃’……L_n-1、L_n-1’、L_nThe mathematical relationship is satisfied: l is₁<L_n<L₂<L₃<……<L_n-1Or L₁<L₂<L₃<……<L_n-1<L_n，L₂＝L₂’，L₃＝L₃’……L_n-1＝L_n-1', the centers of all the release holes are not on the same circle.

4. A stent system according to claim 3 wherein the number of release holes is at least 4, the release rings each passing end to end through the first release hole such that in the second state the position of the release head relative to the first release hole is defined, the last release hole comprising a double-hole structure through which the release rings are sequentially interleaved.

5. The stent system according to claim 3 wherein the first, second and third release holes … … have a cavity length dimension M and the tail release hole has a cavity length dimension M₁、M₂、M₃……M_nWhen the release ring is linear, the outer diameter of the release ring itself is M₀Then M is₁、M₂、M₃……M_nThe mathematical relationship is satisfied: m₁>2×M₀，M₂>3×M₀，M₃>3×M₀……M_n-1>3×M₀，M₀<M_n≤3×M₀，0.08mm≤M₀≤1mm。

6. The bracket system as claimed in claim 1, wherein the proximal ends of every two adjacent releasing levers are jointed and fixedly connected to form a releasing connector, the distal end of the releasing connector comprises a joint point, the releasing holes are positioned on the releasing connector, and the central axes of the rest of the releasing holes do not pass through the joint point and are positioned at one side close to the releasing head except that the central axes of the first releasing hole and the last releasing hole pass through the joint point; the release holes and the release rings are in a penetrating structure, for any one of the release holes, on one side close to the release head, the release ring is arranged above, the release hole is arranged below, on one side far away from the release head, the release ring is arranged below, and the release hole is arranged above.

7. The bracket system as claimed in claim 1, wherein the central axis of the release hole forms an angle b with the plane of the proximal regions of the corresponding adjacent two release levers, which satisfies: 0 degrees < b <90 degrees, and the distance between the first release holes and the surface enclosed by the first support section is the largest.

8. The stent system according to claim 1 wherein the release head comprises a release head and a release neck, the release head having a maximum dimension that is at least the maximum dimension of the release neck or at least 4 times the release loop diameter, and the release head central axis forming an angle γ with a plane defined by the first support section proximal region support bars that satisfies: gamma is more than or equal to 5 degrees and less than 90 degrees.

9. The stent system of claim 1, wherein a release extension rod is fixedly connected to the proximal end of the first release hole, an auxiliary release hole is provided at the proximal end of the release extension rod, the release rings pass through the auxiliary release hole end to end, and the position of the release head relative to the auxiliary release hole is defined in the second state, and the auxiliary release hole is located between the first release hole and the inner wall surface of the intermediate support section.

10. The bracket system of claim 6, wherein all of the release lever exterior surfaces are wrapped with a wrap that wraps around to form the release aperture at the release connection.

11. The bracket system of claim 10, wherein the winding body is formed with a reinforcing structure on the release lever that fixedly connects the release link, the release aperture and the release lever and defines the relative position of the release aperture on the release lever.

12. The stent system according to claim 1 wherein the delivery system comprises an inner core assembly, a middle layer assembly, and an introducer sheath assembly configured for mutual axial movement, the inner core assembly being removably coupled to the release head, the middle layer assembly having a distal region provided with a middle tube, the release ring and release head being accessible to and accessible from the middle tube.

13. The stent system of claim 1, further comprising a capture system comprising a snare, a capture inner sheath, and a capture outer sheath, the release holes, the release loops, the release head, the snare, and the capture inner sheath and/or the capture outer sheath cooperating such that the stent can be captured and withdrawn outside the body.