Disclosure of Invention
The utility model aims to provide an object taking support, an object taking device and an object taking system, which are used for solving the problems of low treatment efficiency, low treatment success rate and the like in the prior art when thrombus, calculus and other embolism are treated.
In order to achieve the above object, according to a first aspect of the present utility model, there is provided a stent which is capable of self-expanding, the stent being made of a mesh tube and forming a distal curved section and a proximal loading section, a part of the tube section of the mesh tube being turned outside the mesh tube to form the distal curved section, the other part of the tube section of the mesh tube being not turned to form the proximal loading section, the distal curved section having an umbrella-shaped mesh surface which is concave and faces the proximal end of the stent.
Optionally, the radial dimension of the distal curved section is greater than or equal to the diameter of the target lumen, and the mesh density of the distal curved section is progressively sparse from the center to the rim.
Optionally, the stent graft further comprises a cover disposed over the distal curved section, the cover covering a portion of the mesh of the distal curved section.
Optionally, the cover film is disposed at a mesh-sparse region of the distal curved section.
Optionally, a developing structure is disposed on the distal curved section, the developing structure being disposed at a location of maximum radial dimension of the distal curved section.
Optionally, the developing structure includes an extension rod and a developer disposed on the extension rod, the extension rod is disposed in the mesh of the distal bending section, one end of the extension rod is connected to the mesh support rod, and the other end of the extension rod is a free end.
Optionally, the distal curved section includes a proximal and distal rail section, the distal and proximal rail sections being oppositely disposed in an axial direction of the retrieval bracket, the proximal rail section being closer to a proximal end of the retrieval bracket than the distal rail section.
Optionally, the distal rail section is curved toward a proximal end of the retrieval stent, the proximal rail section is curved toward the distal rail section, and the proximal rail section has a sparser mesh than the distal rail section.
Optionally, the shape of the proximal blocking section is arc-shaped or broken-line-shaped, and the shape of the distal blocking section is arc-shaped or broken-line-shaped.
Optionally, the shapes of the proximal blocking section and the distal blocking section are arc-shaped and are directly connected, or the shape of the distal blocking section is arc-shaped, the shape of the proximal blocking section is a fold line shape, the distal blocking section is directly connected with the proximal blocking surface, or the shapes of the proximal blocking section and the distal blocking section are fold line shapes, and the proximal blocking section is connected with the distal blocking section through an arc-shaped transition net surface.
Optionally, the distal curved section is rolled with the tail end of the proximal loading section turned outwards to form an atraumatic end, and a soft wrap is provided at the end face of the atraumatic end.
Optionally, the proximal loading section is a straight pipe section integrally, or the proximal loading section includes a plurality of radially outward bulged convex units, a plurality of convex units are sequentially arranged at intervals in the axial direction of the article taking support, adjacent convex units are connected through a connecting part extending straight, and all the convex units and the distal bending section are integrally formed.
Optionally, the structures of the plurality of the convex units are the same or different, and the convex units adopt any one shape or a combination of a plurality of shapes of sphere, disk, cylinder, basket and net bag.
Optionally, the radial dimension of the plurality of the convex units gradually increases or decreases from the distal end to the proximal end of the object taking support, and/or the mesh density of the plurality of the convex units gradually becomes sparse from the distal end to the proximal end of the object taking support.
Optionally, the male unit is deflectable proximally or distally.
In order to achieve the above object, according to a second aspect of the present utility model, there is provided a retrieval device comprising a core tube and the retrieval stent of any one of the above, the retrieval stent being provided on a distal periphery of the core tube, the retrieval stent being connected to the core tube by the proximal loading section.
Optionally, the number of the article taking brackets is multiple, and the article taking brackets are sequentially arranged at intervals along the axial direction of the core tube.
Optionally, the mesh density of the plurality of the fetching holders is gradually reduced from the distal end to the proximal end of the core tube, and/or the radial dimension of the plurality of the fetching holders is gradually reduced or increased from the distal end to the proximal end of the core tube.
Optionally, the stent further comprises a covering film disposed on the distal bending section, the covering film covering a part of the mesh openings of the distal bending section, and the covering film is disposed on at least one of the distal-most stent.
Optionally, the proximal end of the proximal loading section is fixedly connected to the core tube, or the proximal end and the distal end of the proximal loading section are both fixedly connected to the core tube.
Optionally, the proximal loading section is fixedly connected to the core tube by a developing ring.
Optionally, the number of the object taking support is one, the proximal loading section includes a plurality of radially outwards bulged convex units, a plurality of convex units are sequentially arranged at intervals in the axial direction of the object taking support, all the convex units are integrally formed with the distal bending section, the proximal side of the most proximal one of the convex units is fixedly connected with the core tube to form a proximal fixed point, the transitional connection part of the distal bending section and the most distal one of the convex units is fixedly connected with the core tube to form a distal fixed point, and the part of the proximal loading section between the proximal fixed point and the distal fixed point is not connected with the core tube.
Optionally, the core tube has a rigid section at a proximal end and an elastic section at a distal end, and the stent is disposed on the elastic section.
To achieve the above object, according to a third aspect of the present utility model, there is also provided an article taking system, comprising:
the object taking device of any one of the claims;
a delivery device for loading the object retrieval device to deliver the object retrieval device to a target lesion; the method comprises the steps of,
and the suction device is connected with the conveying device and applies suction force through the conveying device so as to suck the embolic material at the target lesion.
In summary, the fetching bracket provided by the utility model can be self-expanded, the fetching bracket is prepared through the webmaster, a part of the pipe section of the webmaster is turned towards the outside of the webmaster to form a distal bending section of the fetching bracket, and the other part of the pipe section which is not turned over by the webmaster is formed into a proximal loading section of the fetching bracket, so that the distal bending section has a concave umbrella-shaped net surface facing the proximal end of the fetching bracket.
Taking thrombus as an example, the configuration is that the stent is formed by adopting a net pipe, even if the stent is bent outwards, the radial support of the distal bending section can be ensured, and further, in the thrombus taking process, the stent is not only not easy to be extruded and deformed by the thrombus, but also can effectively crush the thrombus and capture the thrombus, in the withdrawing process, the captured thrombus is not easy to fall off from the surface of the stent or escape from meshes of the stent, especially for some thrombus with higher hardness, the stent is not easy to deform and take the thrombus out of the body in the withdrawing process, the opening at the tail end of the stent is not closed, so that the stent is good in flexibility, is not easy to collapse in the tortuous vessels, the contact surface between the distal bending section and the blood vessels is reduced, the damage to the blood vessels is small when the thrombus is scraped, and in the recovering process, the stent is better guided and stored in the conveying device by the distal bending section. Therefore, compared with the existing thrombus taking structure, the thrombus taking efficiency of the thrombus taking support is improved, and the thrombus taking effect is better.
Because the object taking device and the object taking system provided by the utility model belong to the same conception, the object taking device and the object taking system provided by the utility model have all the advantages of the object taking bracket provided by the utility model, and the beneficial effects of the object taking device and the object taking system provided by the utility model are not repeated one by one.
Detailed Description
The utility model will be described in further detail with reference to the drawings and the specific embodiments thereof in order to make the objects, advantages and features of the utility model more apparent. It should be noted that the drawings are in a very simplified form and are not drawn to scale, merely for convenience and clarity in aiding in the description of embodiments of the utility model. Furthermore, the structures shown in the drawings are often part of actual structures. In particular, the drawings are shown with different emphasis instead being placed upon illustrating the various embodiments. It should be further understood that the terms "first," "second," and the like in this specification are used solely to distinguish one from another component, element, step, or the like in the specification and do not necessarily denote a logical or sequential relationship between the individual components, elements, steps, or the like, unless otherwise indicated.
The definition of "proximal" and "distal" herein is: "distal" generally refers to the end of the medical device that first enters the patient during normal operation, and "proximal" generally refers to the end of the medical device that is near the operator during normal operation. The "distal" and "proximal" in the present document are not directed towards the ends of the structure, but rather are relative positions, e.g. the distal end of the access stent is not the end of the access stent, but rather is a position relatively close to the end of the access stent. "axial" herein generally refers to a direction along a central axis, such as along the central axis of the access stent or core tube, "radial" generally refers to a direction perpendicular to the axial direction, and "circumferential" refers to a direction about the central axis. Herein, the target lumen may be a blood vessel, bile duct, ureter, or the like. The term "radial dimension" as used herein refers to a length in the diametrical direction, and is mainly a dimension in the unfolded state; "inner" refers to a location near the central axis and "outer" refers to a location away from the central axis.
The utility model provides a fetching bracket, a fetching device and a fetching system, and further solves the problems of low treatment efficiency, low treatment success rate and the like in the prior art when thrombus, calculus and other embolism materials are treated.
The following description refers to the accompanying drawings. In the following description, the following embodiments and features in the embodiments may be mutually complemented or combined with each other without conflict.
Example 1
The present embodiment, which is described by taking intravascular thrombus removal as an example, first, referring to fig. 1 and fig. 2a and 2b, provides an object taking system, which includes an object taking device 100, a delivery device 200, and a suction device 300. The retrieval device 100 includes a self-expanding retrieval stent 101. The stent 101 is made of mesh tubing, such as cut or woven to form mesh tubing, which is then heat set to form the stent 101 of the desired configuration.
Referring to fig. 3a and 3b, the stent 101 has a distal bending section 103 and a proximal loading section 105, in practice, a part of the tube section of the mesh tube is turned to the outside of the mesh tube to form the distal bending section 103, and the other part of the tube section that is not turned is used as the proximal loading section 105. The proximal loading section 105 may be loaded on the distal periphery of the core tube 102 to effect a positional mounting of the retrieval stent 101 on the core tube 102, and the distal curved section 103 has a concave umbrella-like web facing the proximal end of the retrieval stent 101, which may be shaped as a fold line or an arc, or a combination of fold lines and arcs. The transition between the distal curved section 103 and the proximal loading section 105 is preferably smooth, i.e., the transition between the distal curved section 103 and the proximal loading section 105 is smooth, preventing stress concentrations. Optionally, the distal curved section 103 is in an arcuate or linear transition with the proximal loading section 105.
Referring back to fig. 1 and 2a and 2b, the retrieval device 100 further includes a core tube 102, with at least one retrieval bracket 101 disposed on a distal periphery of the core tube 102. After the stent 101 is positioned and mounted on the core tube 102, the umbrella-shaped mesh surface of the stent 101 when fully deployed is first curved toward the proximal end of the stent 100 so as to receive and capture thrombus.
The number of the fetching holders 101 may be plural, and the plural fetching holders 101 may be sequentially arranged at intervals along the axial direction of the core tube 102, for example, equidistantly or non-equidistantly. The present utility model is not limited to a particular number of access racks 101, although three access racks 101 are shown, in other embodiments, the access device 100 may include more or less than three access racks 101 (e.g., one access rack 101, two access racks 101, four access racks 101, etc.).
During surgery, the delivery device 200 is required to access the body, and thus the delivery device 200 is used to load the delivery device 100 and to deliver the delivery device 100 to the targeted lesion in compression. Of course, the function of the conveying device 200 may have other functions in addition to the delivery of the object taking device 100, such as controlling the release and recovery of the object taking device 100, etc., and herein, the structure and function of the conveying device 200 may be understood by those skilled in the art according to the prior art, and the present utility model will not be described in detail.
In the process of thrombus extraction, it is often necessary to inhale and guide thrombus out of the body in cooperation with the aspiration device 300, thereby improving thrombus extraction efficiency and thrombus extraction effect. For this purpose, the aspiration device 300 is used to aspirate the thrombus captured by the object device 100, the aspiration device 300 may be detachably or non-detachably connected to the delivery device 200, and the aspiration device 300 is adapted to apply aspiration force through the delivery device 100 to aspirate the thrombus at the target lesion. The structure and function of the suction device 300 are also understood by those skilled in the art and will not be described in detail herein.
It should be understood that, unlike the thrombus taking structure in the prior art, the thrombus taking support 101 provided in this embodiment adopts the mesh tube to form, the radial supporting force is enhanced, and in the thrombus taking process, the thrombus taking support 101 is not only not easy to be extruded and deformed by thrombus, but also can effectively crush the thrombus and capture the thrombus, in addition, in the withdrawing process, the captured thrombus is not easy to fall off from the surface of the thrombus taking support 101 or escape from the mesh hole 107 of the thrombus taking support 101, so that the thrombus taking efficiency is improved, and the risk of plugging the distal end of a blood vessel by the thrombus is also reduced. Especially for some thrombus with larger hardness, the thrombus is taken away from the body in the retracting process easily because the stent 101 is not easy to deform, so that the catching success rate of the thrombus is increased. Not only is the tail end 101a (see fig. 3a, namely the tail end 101a of the distal bending section 103) of the fetching support 101 made of the net tube not closed, so that the fetching support is good in flexibility, is not easy to collapse when working in a tortuous blood vessel, so that the possibility of escaping or cracking captured thrombus is reduced, meanwhile, the probability of damaging the blood vessel is also reduced because the contact surface of the distal bending section 103 and the blood vessel is reduced, and for some thrombus tightly adhered to the blood vessel, the structure design of the fetching support 101 is easy to scrape, catch and transfer the wall-attached thrombus, so that the probability of removing thrombus is further increased. The thrombus taking support 101 has the advantages that in the recovery process, the everting and curling structural design can better lead the thrombus taking support 101 to be guided and stored in the conveying device 200, so that the recovery operation difficulty is reduced.
It should be further appreciated that, during the self-expanding deployment process of the vascular lesion of the stent 101, the distal bending section 103 can be utilized to cut and break the large thrombus so as to facilitate suction and export, and further, after the stent 101 is completely deployed, the thrombus is timely collected in the umbrella-shaped mesh surface facing the proximal bending, so as to collect the thrombus and reduce the risk of the thrombus escaping distally, and further, during the retraction process, the umbrella-shaped mesh surface of the distal bending section 103 of the stent 101 can be tightly contacted with the inner wall of the lumen, and the thrombus tightly adhered to the wall of the blood vessel can be effectively scraped and collected, so that the thrombus in the lumen and on the wall of the blood vessel can be better removed and captured, the thrombus taking efficiency is high, and the treatment effect is good.
In some embodiments, the fetching device 100 includes a plurality of fetching holders 101, where the plurality of fetching holders 101 are each independently mounted on the core tube 102, and adjacent fetching holders 101 are disposed at a distance from each other, so that thrombus can be accommodated between umbrella-shaped mesh surfaces of the adjacent fetching holders 101, and is less likely to escape distally. In addition, the structural design of the plurality of object taking brackets 101 also increases the flexibility and adaptability of the object taking device 100 in tortuous vessels and reducing vessels, reduces the possibility of inward collapse of the object taking brackets 101 in the tortuous vessels, and further improves the capability of the object taking device 100 for embedding and capturing thrombus. Simultaneously, the plurality of taking supports 101 can take thrombus out of the body in a segmented mode, so that a large amount of thrombus can be quickly removed.
In the illustrated embodiment, the proximal loading section 105 of each retrieval bracket 101 is generally cylindrical (corresponding to a flat tube section) and may be integrally sleeved on the distal outer peripheral surface of the core tube 102, thereby fixedly connecting the proximal end 101b of the proximal loading section 105 (i.e., the proximal end of the retrieval bracket 101) to the core tube 102. The connection between the proximal loading section 105 and the core tube 102 can be performed in a number of ways, at least one of which is selectable. The following is an exemplary illustration.
Alternatively, the proximal loading segment 105 may be thermally fused, glued, or mechanically coupled to the core tube 102, and the mechanical coupling may be any type of coupling known to those skilled in the art, including, but not limited to, welding. In this embodiment, the proximal loading section 105 is fixedly connected to the core tube 102 by a developing ring 104, and the developing ring 104 is sleeved outside the proximal loading section 105, so that the proximal end 101b of the proximal loading section 105 is wrapped and fixed on the distal peripheral surface of the core tube 102. The developer ring 104 is made of a radiopaque material, the particular material not being required.
The fetching rack 101 is a self-expanding net structure, which is in a compressed state under the action of external force, and is automatically converted into an expanded state from the compressed state after the external force is removed. The fetching bracket 101 is in a natural state when no external force acts, and the fetching bracket 101 in the natural state is in an unfolding shape. The stent 101 is compressed for delivery into the delivery device 200 in a compressed state, and generally the stent 101 is compressed into a compressed shape that is generally linear and extends generally parallel to the core tube 102, that is, the stent 101 is inverted in a position substantially collinear with the proximal loading section 105 when compressed, such delivery being small in size. After the restraint of the conveying device 200 is removed, the fetching rack 101 can be automatically expanded to be in an unfolding state. The access stent 101 is transitionable between a compressed state and an expanded state.
The access stent 101 is often made of a metallic material, such as a metal or alloy material, with a shape memory effect being particularly preferred, including but not limited to nickel titanium alloys. Here, the metallic mesh tube may be prepared in various ways known in the art, however the metallic mesh tube shaping process forms the retrieval stent 101 with the proximal loading section 105 and the distal bending section 103 integrated together. As is well known in the heat setting arts, a mold may be used to hold the metal mesh tube in its desired final configuration and subjected to an appropriate heat treatment to set the retrieval bracket 101 to the desired configuration.
In some embodiments, the fetching rack 101 is made by integrally cutting metal pipe, and the cutting mode is not limited to laser cutting. In other embodiments, the stent 101 is integrally woven from a plurality of wires, and the weaving method is not particularly limited.
The number of stent grafts 101 may be determined based on lesion length (e.g., thrombus length), thrombus length of stent grafts 101, etc. For example, to achieve rapid removal of a large amount of thrombus, a plurality of stent-grafts 101 are generally provided, and each stent-graft 101 is capable of taking the thrombus out of the body in sections; if the device is suitable for removing a small amount of thrombus, only one fetching bracket 101 can be arranged. The length and radial dimensions of the plurality of access holders 101 may be the same or different. It should be appreciated that the plurality of stent grafts 101 may be used to break thrombus multiple times, thereby providing better thrombus breaking and increasing the flexibility and adaptability of the stent graft 100 in tortuous vessels and reducing vessels.
The utility model is not limited to the shape of the mesh 107 on the access rack 101, and the mesh 107 may be any suitable shape, such as: diamond, diamond-like, rectangular, circular, oval, or other shapes. In some embodiments, the mesh 107 of the proximal loading section 105 is generally diamond-shaped or diamond-like, the mesh shape of the distal curved section 103 is not limited, and the mesh 107 of the distal curved section 103 may alternatively be one or more combinations of rectangular, circular, diamond-shaped, oval-shaped.
In this embodiment, the mesh density of the proximal loading section 105 is substantially uniform, while the mesh density of the distal bending section 103 gradually changes during the everting bending process, which causes the mesh density of the distal bending section 103 to gradually diverge from the center to the edge, forming a mesh dense region 1031 near the center and a mesh sparse region 1032 away from the center on the distal bending section 103, see fig. 3c. The mesh-dense region 1031 has a larger number of meshes than the mesh-sparse region 1032, and the mesh size (aperture diameter) of the mesh-dense region 1031 is smaller than the mesh size of the mesh-sparse region 1032. The dense mesh region 1031 is beneficial to collecting thrombus and reducing the probability of thrombus escaping to a far branch, while the sparse mesh region 1032 is beneficial to breaking large thrombus in the process of everting, expanding and bending or retracting the stent 101, and meanwhile, the dense-center and sparse-edge mesh distribution can better bag thrombus and reduce sheath receiving resistance.
When the stent 101 is fully deployed, preferably, the radial dimension of a certain position (such as the maximum diameter position) on the distal curved section 103 is greater than or equal to the diameter of the blood vessel where the lesion is located, so that the everted distal curved section 103 can be closely contacted and supported with the inner wall of the blood vessel and can move along the inner wall of the blood vessel, thereby effectively scraping and collecting thrombus attached to the wall of the blood vessel in the retracting process, and collecting the crushed thrombus into the umbrella-shaped mesh surface of the distal curved section 103 along the inner wall of the blood vessel, and simultaneously, blood flow can also pass through the distal curved section 103 of the stent 101, thereby ensuring smoothness of blood flow and life safety of a patient.
The core tube 102 is an elongate tubular structure that can be internally passed through the guidewire 10. In the illustrated embodiment, the distal end of the core tube 102 is secured with a guide cap 106, and the distal surface of the guide cap 106 is smooth and does little damage to surrounding tissue. The presence of the guide cap 106 facilitates advancement of the access device 100 within the lumen. The guide cap 106 may be a hollow conical cap with a spherical end surface at the distal end, the junction of the conical cap and the core tube 102 forming a step that can rest against the distal end surface of the delivery catheter 201 of the delivery device 200 without entering the lumen of the delivery catheter 201. In practice, the core tube 102 may be operated to push the object picking apparatus 100 out of the conveyor 200 for release, and if the release position of the object picking apparatus 100 is not appropriate, the object picking apparatus 100 is again recovered into the conveyor 200, and after the position is adjusted, the object picking apparatus 100 is released again. After the thrombus is removed, the core tube 102 is operated again, and the material removing device 100 is recovered into the conveying device 200, so that the thrombus is led out of the body.
In one embodiment, the core tube 102 includes an elastic segment disposed at the distal end of the core tube 102 and a rigid segment disposed at the proximal end of the core tube 102, the elastic segment being softer than the rigid segment. The elastic section is used for installing all the fetching holders 10. The elastic section and the rigid section can be assembled and connected after being integrally or separately formed. The distal end of the rigid segment and the proximal end of the flexible segment may be connected by heat welding, snap-fit, or other known means, as the application is not limited in this regard. The rigid section of the core tube 102 facilitates force transfer, while the flexible section of the core tube 102 is capable of freely flexing as the retrieval stent 101 flexes, thereby improving the flexibility and applicability of the retrieval device 100 in tortuous vessels. In other embodiments, rigid segments may be employed throughout the core tube 102.
In some embodiments, delivery device 200 includes a delivery catheter 201 and a sheath 202 coaxially disposed from inside to outside. The core tube 102 extends through the delivery conduit 201. The delivery catheter 201 can compress and carry all of the stent 101 to the site of the thrombus. The delivery catheter 201 also extends through the sheath 202 and is pushed through the sheath 202, and after the removal of the thrombus, the delivery device 100 may be guided and received in the sheath 202. The proximal end of the sheath 202 needs to be sealed by a sealing flap to prevent blood from seeping out of the proximal end of the sheath 202.
In some embodiments, suction device 300 includes suction tube 301 and connection mount 302. Further, the suction apparatus 300 further comprises a suction device (not shown). The connection hub 302 is removably mounted to the proximal end of the delivery catheter 201, and a flexible hemostatic sealing valve 303 is typically provided at the proximal opening of the connection hub 302 to seal the proximal end of the connection hub 302 with the hemostatic sealing valve 303. The proximal end of the delivery catheter 201 is connected to the connection hub 202 to form a main passageway through which the delivery device 100 passes into and out of the delivery catheter 201. The suction tube 301 is disposed on the side of the connection base 302, and the distal end of the suction tube 301 is connected to the side hole of the connection base 302. The proximal end of the suction tube 301 is often provided with a one-way valve 304, the one-way valve 304 being used for connection to a suction device which applies suction to the delivery catheter 201 through the suction tube 301. The suction device may be selected from negative pressure suction devices, such as vacuum pumps and the like.
The use of the retrieval system 100 is further described below in conjunction with fig. 4 a-4 f, and is illustrated as an intravascular retrieval of a thrombus.
As shown in fig. 4a, when it is desired to clear a thrombus from a diseased site of a blood vessel, the guidewire 10 is first advanced along the blood vessel 20 to the thrombus 30 and the guidewire 10 is advanced completely through the thrombus 30.
As shown in fig. 4b, the sheath 202 is pushed along the guidewire 10 to a position adjacent to the thrombus 30, and then the position of the sheath 202 is kept unchanged, and the delivery catheter 201 carrying the retrieval device 100 is also pushed along the guidewire 10 until the guide cap 106 at the distal end of the core tube 102 is completely passed through the thrombus 30.
As shown in fig. 4 c-4 e, the delivery catheter 201 is then gradually retracted back while holding the core tube 102 stationary until the stent 101 is fully expanded, at which point the distal curved section 103 of the stent 101 will fully embed and fracture the thrombus 30. Further activation of the aspiration device draws thrombus at the distal opening 202a of the sheath 202 into the lumen of the delivery catheter 201 and to the aspiration tube 301. If there are a plurality of the fetching holders 101, the plurality of fetching holders 101 are sequentially deployed during the retracting process of the delivery catheter 201.
After all of the stent grafts 101 have been deployed, the core tube 102 is retracted proximally, so that all of the stent grafts 101 are also slowly moved proximally, so that the thrombus 30 is gradually scraped, squeezed, cut and broken and trapped between the distal curved section 103 of the stent grafts 101 and the adjacent stent grafts 101 and gradually moved into the vicinity of the distal opening 202a of the sheath 202, during which time aspiration of the thrombus 30 is continued using aspiration equipment until the distal last stent graft scaffold 101 is retracted into the sheath 202, at which time a portion of the thrombus is collected in the sheath 202 and finally withdrawn with the stent graft 100.
Preferably, the mesh density of the plurality of stent grafts 101 in the stent delivery device 100 is progressively less dense from the distal end to the proximal end. This allows the proximal stent 101 to have relatively sparse mesh openings 107, which facilitates interception of broken large thrombi, while the more distal stent 101 has relatively dense mesh openings 107, which facilitates interception of fine thrombi escaping distally. However, in other embodiments, the mesh density of the plurality of retrieval racks 101 may also be the same.
< example two >
Referring to fig. 5, the structure of the fetching rack 101 provided in the second embodiment of the present utility model is substantially the same as that of the fetching rack 101 provided in the first embodiment, and the same parts will not be described again, and only the differences will be described below.
As shown in fig. 5, unlike the first embodiment, in the stent graft 101 provided in the second embodiment, a covering film 108 is provided on the distal curved section 103 of the stent graft 101, and the covering film 108 covers a part of the mesh holes 107 of the distal curved section 103. Preferably, the cover film 108 covers only the mesh sparse zone 1032 of the distal curved section 103 for covering the meshes 107 of the mesh sparse zone 1032, while the meshes 107 of the mesh dense zone 1031 of the distal curved section 103 are not covered by the film. The presence of the membrane 108 may further collect and block escaping broken thrombus, enhancing the effectiveness of the thrombus extraction, while maintaining the patency of the intraluminal blood flow. The cover 108 may be disposed on an inner or outer surface of the distal curved section 103. The cover 108 may be sutured secured to the distal curved segment 103.
Further, when the number of the fetching holders 101 is plural, it is preferable that the covering film 108 is provided on at least one of the fetching holders 101 at the most distal end, and the covering film 108 may be provided or not provided on the fetching holders 101 at other positions.
Example III
Referring to fig. 6a and 6b, the structure of the fetching rack 101 according to the third embodiment of the present utility model is substantially the same as that of the fetching rack 101 according to the first embodiment, and the same parts will not be described again, and only the differences will be described below.
As shown in fig. 6a and 6b, unlike the first embodiment, the third embodiment provides the stent 101 in which the developing structure 110 is provided on the mesh struts 109 of the mesh 107 of the distal curved section 103 or in the vicinity of the mesh struts 109, and the developing structure 110 is capable of developing under X-rays. So that the operator can observe the position and the unfolding condition of the fetching bracket 101 in the tube cavity according to the developing structure 110 in real time during the operation. Visualization structure 110 is preferably disposed at a maximum radial position of distal curved segment 103 after deployment to facilitate visualization of the apposition of distal curved segment 103. The developing structure 110 is preferably a plurality of developing structures 110 distributed on the same circumference. However, those skilled in the art will recognize that the visualization structure 110 may be disposed at virtually any suitable location on the distal curved segment 103 and may be distributed at different locations on the distal curved segment 103, as the utility model is not limited in this regard. The manner in which the visualization structure 110 is provided on the distal curved section 103 is also not particularly limited in the present utility model, and one skilled in the art may select at least one structure to perform. The following is an exemplary illustration.
In one embodiment, as shown in fig. 6b, the developing structure 110 includes an extension bar 110a and a developer 110b disposed on the extension bar 110 a. An extension rod 110a is provided in the mesh 107, one end of the extension rod 110a is connected to the mesh strut 109, and the other end of the extension rod 110a is a free end. The developer 110b may be implemented in a number of structures including, but not limited to, developer wire, developer ring. In the illustrated embodiment, the developer 110b employs a developer wire that is helically wound around the extension rod 110 a. The extension rod 110a can be integrally formed with the mesh tube, such as integrally cut, and is convenient to manufacture. The material from which the developer 110b is made is a conventional radiopaque material including, but not limited to, platinum iridium alloy, tungsten, and the like. The developer 110b may be fixedly coupled to the extension bar 110a in a variety of ways, such as by welding, glue bonding, or clamping. In other embodiments, the development structure 110 may be made directly from a composite core wire (e.g., DFT) that includes a nickel-titanium sleeve and a development core wire that is encased by the nickel-titanium sleeve.
It should be noted that, although the present embodiment is described taking the extension rod 110a and the developer 110b as an example, it should be understood by those skilled in the art that this is not a limitation of the present utility model, and in other embodiments, the developing structure 110 may be directly made of a developing sleeve or a developing wire, and only need to be directly sleeved or wound on the mesh support 109, and the developing structure 110 may be disposed at a grid node, for example, a developing point at the grid node.
Example IV
Referring to fig. 7 to 10, the structure of the fetching rack 101 according to the fourth embodiment of the present utility model is substantially the same as that of the fetching rack 101 according to the first embodiment, and the same parts will not be described again, and only the differences will be described below. It should be noted that fig. 7 to 10 are simplified schematic views of the fetching rack 101, and only the outline of the fetching rack 101 is illustrated without showing the mesh shape in detail.
Unlike the first embodiment, the fourth embodiment provides a stent graft 101 in which the distal curved section 103 may exhibit different bending angles and bending shapes.
As shown in fig. 7, in an exemplary embodiment, the distal curved section 103 of the stent 101 is formed of a first mesh surface 1033 and a second mesh surface 1034 that are sequentially disposed from the inside to the outside, i.e., the first mesh surface 1033 and the second mesh surface 1034 are directly connected. When the retrieval bracket 101 is fully deployed, the first web 1033 is bent toward the proximal end of the retrieval bracket 101, and the second web 1034 is bent from the first web 1033 toward the first web 1033, which causes the trailing end 101a of the retrieval bracket 101 to be received within the umbrella-shaped web and toward the first web 1033. At this point, during withdrawal, the second web 1034 shares a substantial portion of the withdrawal resistance, thereby reducing the likelihood of distal tip-up of the crimped web due to excessive thrombus, making the distal curved section 103 less prone to deformation. In yet another embodiment, and referring to fig. 3b, the distal curved section 103 of the stent 101 is substantially composed of only the first web 1033 curved proximally. In the embodiment shown in fig. 7, the first web 1033 is an arcuate web and forms a distal blocking section, and the second web 1034 is also an arcuate web and forms a proximal blocking section, the distal blocking section and the proximal blocking section being oppositely disposed in the thrombus extraction direction, the proximal blocking section being closer to the proximal end 101b of the stent 101 than the distal blocking section.
As shown in fig. 8, in another exemplary embodiment, the distal curved section 103 of the fetching rack 101 is formed by combining an arc-shaped mesh surface and a fold-line-shaped mesh surface, specifically, the distal curved section 103 is formed by sequentially arranging a first mesh surface 1033 and a second mesh surface 1034 from inside to outside, the first mesh surface 1033 and the second mesh surface 1034 are directly connected, the first mesh surface 1033 is an arc-shaped mesh surface, and the second mesh surface 1034 is a fold-line-shaped mesh surface. The first web 1033 is smoothly transitioned to the second web 1034. At this time, when the fetching rack 101 is fully unfolded, the first web 1033 is also bent toward the proximal end 101b of the fetching rack 101, and the second web 1034 is bent toward the first web 1033, so that the tail end 101a of the fetching rack 101 is still received in the umbrella-shaped web and faces the first web 1033. In the embodiment shown in fig. 8, the first web 1033 remains in a distal cross-sectional area and the second web 1034 forms a proximal cross-sectional area. The second web 1034 here primarily serves to promote the supportive and intercepting properties of the distal curved segment 103. At this point, the distal curved section 103 is better supportive and interceptive, and thus has better clearance.
The mesh density of the proximal and distal rail sections may be the same or different. Preferably, the proximal blocking section has a sparser mesh than the distal blocking section, so that the proximal blocking section intercepts the thrombus proximal to the distal curved section 103, and the distal blocking section intercepts the thrombus further distal to the distal curved section 103, whereby during withdrawal, the larger mesh 107 of the proximal blocking section breaks up the bulk thrombus while the denser mesh 107 of the distal blocking section intercepts the fine thrombus from escaping.
As shown in fig. 9a and 9b, in another exemplary embodiment, when the access stent 101 is fully deployed, the distal curved section 103 is rolled out and turned away from the trailing end 101a of the proximal loading section 105 to form an atraumatic end 1035 (not limited to a circular ring), and the atraumatic end 1035 may have a bend angle less than, equal to, or greater than 360 °. The atraumatic end 1036 is configured to reduce trauma to the vessel from the trailing end 101a of the stent graft 101 during self-expanding deployment or retrieval. Preferably, the end face of the atraumatic end 1035 is provided with a soft coating 1036, and the soft coating 1036 is made of a softer polymer material, so that the damage risk of the tail end 101a to the blood vessel can be further reduced. Thus, the design of atraumatic end 1035 and flexible covering 1036 may reduce trauma to the vessel from trailing end 101a of stent graft 101 during self-expanding deployment or retrieval into sheath 202.
As shown in fig. 10, in other exemplary embodiments, the distal curved section 103 of the fetching rack 101 is formed by combining an arc-shaped mesh surface and a fold-line-shaped mesh surface, specifically, the distal curved section 103 is formed by sequentially arranging a first mesh surface 1033, a transition mesh surface 1037 and a second mesh surface 1034 from inside to outside, where the first mesh surface 1033 and the second mesh surface 1034 are both fold-line-shaped mesh surfaces, and the transition mesh surface 1037 is an arc-shaped mesh surface. At this time, the transition web 1037 is smoothly connected to the first web 1033, and accordingly, the transition web 1037 is smoothly connected to the second web 1034. When the stent 101 is fully deployed, the first web 1033 is also curved toward the proximal end 101b of the stent 101 and the second web 1034 is curved from the transition web 1037 toward the first web 1033. In the embodiment shown in fig. 10, a first web 1033 of a fold line shape is used as the distal blocking section, while a second web 1034 of a fold line shape forms the proximal blocking section. Thus, the distal blocking section may be an arcuate web or a zigzag web, as may the proximal blocking section. The transition mesh 1037 is supported in contact with the inner wall of the blood vessel. Such distal curved section 103 provides better support and less contact area with the blood vessel, thereby reducing trauma to the blood vessel during thrombus removal.
The bending angle and the bending shape of the distal bending section 103 of the fetching rack 101 can be realized by different heat treatment shaping dies. Further, the retrieval device 100 may be one or more of the various types of retrieval racks 101 described above. In addition, the bending angle and the bending shape of the fetching rack 101 are not limited to those exemplified in the above embodiments, and those skilled in the art can set the bending angle and the bending shape of the fetching rack 101 according to actual needs.
< example five >
Referring to fig. 11a to 11b, the structure of the object-taking device 100 according to the fifth embodiment of the present utility model is substantially the same as that of the object-taking device 100 according to the first embodiment, and the same parts will not be described again, and only the differences will be described below. It should be noted that fig. 11a and 11b are simplified schematic views, and only the outlines of all the fetching holders 101 are illustrated, and the net shape is not shown in detail.
As shown in fig. 11a, in the object-taking device 100 provided in the fifth embodiment, a plurality of object-taking supports 101 are sequentially disposed at the distal end of the core tube 102, and the radial dimensions of the plurality of object-taking supports 101 gradually decrease from the distal end to the proximal end, at this time, the radial dimension of one of the object-taking supports 101 at the most distal end is greater than or equal to the diameter of the blood vessel where the lesion is located, so that the one of the object-taking supports 101 at the most distal end is in close contact with the inner wall of the blood vessel. It should be appreciated that the gradual radial dimension arrangement is beneficial to reducing the resistance of thrombus to the proximal stent 101 during the retraction of the stent 100, reducing the problems of excessive deformation or collapse of the proximal stent 101 during the retraction due to excessive thrombus resistance, and reducing the loss of thrombus during the retraction of the proximal stent 101 during the retraction of the delivery device 200. In addition, the tapered radial dimension of the stent 101 also increases the flexibility and applicability of the entire device 100 in curved vessels and reducing vessels.
As shown in fig. 11b, in the object-taking device 100 provided in the fifth embodiment, a plurality of object-taking supports 101 are sequentially disposed at the distal end of the core tube 102, and the radial dimensions of the plurality of object-taking supports 101 gradually increase from the distal end to the proximal end, and the radial dimension of one of the object-taking supports 101 at the nearest end is greater than or equal to the diameter of the blood vessel where the lesion is located, so that the one of the object-taking supports 101 at the nearest end is in close contact with the inner wall of the blood vessel. Similarly, the plurality of radially tapered stent grafts 101 increases the flexibility and applicability of the overall stent graft 100 in curved and reduced vessels, and particularly the distal stent grafts 101 may extend into smaller diameter vessels (e.g., double pulmonary branches) for thrombus removal, reducing the probability of vessel trauma.
< example six >
Referring to fig. 12a to 12c, the structure of the object-taking device 100 according to the sixth embodiment of the present utility model is substantially the same as that of the object-taking device 100 according to the first embodiment, and the same parts will not be described again, and only the differences will be described below.
As shown in fig. 12a to 12c, unlike the first embodiment, in the object taking device 100 provided in the sixth embodiment, the object taking device 100 includes only one integral object taking bracket 101 except for the core tube 102, and the integral object taking bracket 101 may be formed by braiding heat treatment or by heat treatment after cutting. The fetching rack 101 is in a whole or integral structure, the structure of the distal bending section 103 is basically the same as that of any embodiment, while the proximal loading section 105 is directly configured to include a plurality of radially outwardly bulged convex units 1051, the plurality of convex units 1051 are sequentially arranged at intervals in the axial direction of the fetching rack 101, and all the convex units 1051 and the distal bending section 103 are integrally formed. The plurality of male units 1051 may be identical or different in structure, where the structure includes shape and size. Each of the male units 1051 is connected by a connection 1052 extending substantially straight.
In this embodiment, the mesh holes 107 of the distal curved section 103 are all very dense and have a deployed diameter greater than or equal to the diameter of the vessel at the lesion for collecting the fine fragmented thrombus escaping distally.
The male unit 1051 may have various suitable shapes, which the present utility model is not limited to. Generally, the male unit 1051 may take one or a combination of shapes from the group consisting of spherical, disk-like (including discoid), cylindrical, basket-like, and net-like. When the convex unit 1051 has a circular cross section or an approximately circular cross section, the supporting performance is better, thrombus attached to the wall of the blood vessel can be effectively removed, and the probability of excessive deformation or collapse of the fetching bracket 101 caused by excessive thrombus in the retracting process can be reduced. When the male unit 1051 employs a basket or a string bag, thrombus can be better collected and prevented from escaping distally.
The shape, number, deployment diameter, etc. of the protruding units 1051 are not limited, and may be specifically set according to the use scenario and the intraluminal situation.
As shown in fig. 12a, in an exemplary embodiment, proximal loading section 105 includes a disk-like male unit 1051 and a ball-like male unit 1051, and the positions of disk-like male unit 1051 and ball-like male unit 1051 may be interchanged, not limited to that shown in the figures. The convex units 1051 are integrally connected to each other by a substantially cylindrical connecting portion 1052. When the access stent 101 is fully deployed, the proximal male unit 1051 preferably has a smaller radial dimension than the other male units 1051. Of course, the utility model does not exclude that the radial dimensions of the individual male units 1051 are identical. The deployment diameter of each of the protruding units 1051 may be equal to or greater than the target vessel diameter, and the deployment diameter of each of the protruding units 1051 may also be gradually decreased or increased from far to near.
As shown in fig. 12b, in an exemplary embodiment, the mesh density of each protruding unit 1051 is gradually reduced from far to near, the mesh with the sparse near end can break up the large thrombus better, and the mesh with the dense far end can reduce the probability of thrombus escaping to far branches.
As shown in fig. 12c, in an exemplary embodiment, the proximal loading section 105 includes a disk-like male unit 1051 and a basket-like male unit 1051, and the positions of the disk-like male unit 1051 and the basket-like male unit 1051 may be interchanged, not limited to those shown in the drawings. In this embodiment, the basket-shaped outer protruding unit 151 includes a protruding rod 1051a and a net 1051b, and the protruding rod 1051a can cut a large thrombus while collecting the thrombus in the inner space of the net 1051b when being retracted. This design combines the advantages of each male unit 1051 to enhance the latch extraction.
Referring to fig. 12a to 12c, both the proximal and distal ends of the stent 101 are fixedly connected to the core tube 102, specifically, the proximal end of the proximal-most one of the convex units 1051 is fixed to the core tube 102 and forms a proximal fixed point, the transitional connection between the distal-most one of the convex units 1051 and the distal curved section 103 is fixed to the core tube 102 and forms a distal fixed point, and the portion of the proximal loading section 105 between the proximal fixed point and the distal fixed point is substantially disconnected from the core tube 103 to facilitate the unblocking of blood flow. In the illustrated embodiment, the proximal end of the proximal-most one of the male units 1051 is secured by a developer ring 104, and the transition junction of the distal-most one of the male units 1051 and the distal curved segment 103 is secured by another developer ring 104.
It should be noted that the number of the protruding units 1051 may be one or more, and the number is not limited to two.
< example seven >
Referring to fig. 13, the structure of the object-taking device 100 according to the seventh embodiment of the present utility model is substantially the same as that of the object-taking device 100 according to the above embodiment, and the same parts will not be described again, and only the differences will be described below.
As shown in fig. 13, unlike the above-described embodiments, the present embodiment provides an object extraction device 100 suitable for bile duct or ureter extraction, but the extraction principle is basically similar to that of thrombus extraction.
The description will be given taking the integral article taking rack 101 using the protruding unit 1051 as an example. In other embodiments, the proximal loading section 10 may include a plurality of protruding units 1051 that are each disk-like, and the protruding units 1051 may deflect distally or proximally, where resistance to withdrawal of the protruding units 1051 into the sheath 202 may be reduced.
In the illustrated embodiment, two disk-like male units 1051 are deflected proximally, each male unit 1051 being connected by a substantially cylindrical connection 1052, the mesh density of each male unit 1051 being very dense.
When the stent 101 is fully deployed, both the male unit 1051 and the distal curved section 103 can conform to the inner wall of the lumen of the stone site, thereby pulling the stone in the canal out through the movement of the stent 101 within the lumen during the procedure. Meanwhile, the laminated arrangement of the plurality of convex units 1051 forms a laminated stone-taking structure, so that on one hand, the organ lumen can be cleaned repeatedly, stone-making omission is avoided, and stone-taking efficiency is further improved. The dense mesh of each male unit 1051 can effectively prevent small stones from passing through the mesh. On the other hand, in the process of taking out the stones, the external suction equipment is matched, so that the far-end small stones can be sucked into the suction tube 301, and the stone taking-out rate is improved.
In summary, the object taking support, the object taking device and the object taking system provided by the utility model have at least the following beneficial effects:
firstly, the object taking support adopts an umbrella-shaped form with an outwards curled distal end opening, the contact area between the object taking support and a lumen is small, when thrombus, calculus and other embolism materials are scraped, the damage to the wall of the lumen due to the curled design is small, and in the recovery process, the object taking support can be better guided into a conveying device;
secondly, when the object taking device comprises a plurality of object taking brackets or the object taking brackets are structured to contain a plurality of convex units, the multi-section design can improve the flexibility and the adaptability of the object taking device in the tortuous passages and the reducing passages, thereby reducing the possibility of inward collapse of the brackets in the tortuous passages, improving the capability of embedding and catching emboli and facilitating the transportation and the recovery;
furthermore, after the object taking device is completely unfolded, the everted part of the net surface of the object taking support is tightly contacted with the inner wall of the tube, and the embolism attached to the tube wall can be effectively removed in the retracting process, so that the embolism removing effect is improved;
in addition, when the object taking device is fully unfolded, the emboli can be collected in the curled umbrella-shaped net surface, and particularly, more emboli can be contained in the space between the adjacent object taking brackets or adjacent outer convex units, so that the efficiency of removing the emboli is improved;
In addition, the mesh density of each object taking support or each outer convex unit is gradually sparse from far to near, so that the mesh at the far end is relatively dense, the risk of the embolic object escaping to the far branch can be collected and reduced, the mesh at the near end is relatively sparse, the massive embolic object is broken in the retracting process of the object taking device, and meanwhile, the embolic object is wrapped and transferred to the suction tube, so that the cleaning effect is good, and the cleaning efficiency is high.
It should also be appreciated that while the present utility model has been disclosed in the context of a preferred embodiment, the above embodiments are not intended to limit the utility model. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present utility model still fall within the scope of the technical solution of the present utility model.