CN113967114A

CN113967114A - A kind of aortic rapid repair stent, stent kit and delivery system

Info

Publication number: CN113967114A
Application number: CN202010712818.1A
Authority: CN
Inventors: 丁剑
Original assignee: Shanghai Qi Gong Medical Technology Co ltd
Current assignee: Shanghai Qi Gong Medical Technology Co ltd
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2022-01-25

Abstract

The present application discloses an aortic rapid repair stent, a stent kit and a delivery system. The stent of the present invention includes a stent body and a channel surrounded by the stent body, and is characterized in that the stent body has a woven mesh structure, and the meshes of the mesh structure are expandable and deformable without expansion. The widest point of the mesh is at least 1mm. The stent of the present invention can quickly relieve the risk of arterial dissection or aneurysm at the aorta with branch vessels by applying the braided, high-strength, high-elastic mesh, thereby avoiding the risk of the stent blocking the blood flow of the branch arteries on the one hand. On the other hand, it can quickly repair the aorta in advance, reduce the risk of surgery and reduce the technical difficulty of surgery, thereby winning precious treatment time for patients.

Description

Aorta rapid repair stent, stent kit and delivery system

Technical Field

The present invention relates to stents for placement in the aorta, particularly in the aortic arch and abdominal aortic region for the treatment of aortic dissection or aortic aneurysm.

Background

The arterial vessel wall is formed by closely adhering the intima, media and adventitia. When the inner wall of an arterial blood vessel is locally damaged, the stripping of the tunica media in the arterial blood vessel wall gradually occurs under the strong impact of the arterial blood flow, so that blood enters between the tunica media and the tunica adventitia of the arterial blood vessel wall to form two true and false cavities. Aortic dissection is most common. Aortic dissection weakens the arterial wall and risks rupture at all times, which can lead to death of the patient within minutes once the dissection is ruptured.

Aortic aneurysms are also a condition of abnormal dilation of the aorta. Rupture of an aortic aneurysm can also be fatal to the patient.

Therefore, early diagnosis and timely treatment of aortic dissection and aortic aneurysm are very essential.

Aortic dissection and aortic aneurysm affect the aortic arch, descending aorta and/or abdominal aorta, and stents may be used to isolate the damaged site. The stent treatment has the advantages of small trauma, less bleeding, quick recovery and low mortality, and reduces the incidence of perioperative complications compared with the traditional open surgery.

The convex side of the aortic arch is provided with three branch arterial vessels, namely a head-arm trunk (also named, innominate artery, and branches into a right common carotid artery and a right subclavian artery), a left common carotid artery and a left subclavian artery, in sequence from the end close to the heart. The abdominal aorta has many branches, such as the middle adrenal artery, renal artery, celiac trunk, superior mesenteric artery, inferior diaphragmatic artery, lumbar artery, and sacral median artery, and branches into the right and left iliac arteries at the distal ends.

In stenting procedures, the critical branch arteries, particularly the brachiocephalic trunk, left common carotid artery, left subclavian artery, left and right renal arteries, and celiac trunk, cannot be occluded by stents, or serious complications and even death can occur to the patient. Therefore, it is a conventional practice to open a hole at a portion of the aortic stent corresponding to an important branch artery and to release the stent after aligning the opened hole portion with the branch artery. This increases the difficulty of the procedure and requires an experienced surgeon to perform it. And once the stent is inaccurately positioned during placement or the stent is displaced during release, the blockage of important branch blood vessels can cause serious consequences.

Furthermore, the relative position of the branch arteries varies from person to person, and in particular the relative position of the branch arteries on the abdominal aorta tends to be different for different persons. This requires that the position of the branch vessel on the aorta of each patient be measured in advance and customized to the stent manufacturer. Even so, the position of the blood vessel may shift due to movement or different postures, and the specific position of the blood vessel may deviate from the position of the opening of the customized stent during the operation. To avoid this, experienced surgeons may open the stent intraoperatively (pre-fenestration or in situ fenestration). However, this practice is often not approved by the stent manufacturer, and there is a greater risk of deviation.

The following problems exist with current treatment of aortic dissection and aortic aneurysms. On one hand, the aortic dissection causes the aorta true cavity to be inwards sunken, the aortic aneurysm causes the aorta true cavity to be outwards protruded, and the blood supply problem of the branch false cavity of the aortic dissection part is solved; on the other hand, as described above, there is a problem that the alignment of the branch site is difficult or the operation is complicated in the case of stent therapy.

Since there is a chance of rupture of the aortic dissection or aneurysm at any time and the branch arteries cannot be blocked for a long time, it is vital for the patient to perform the operation as early as possible and to place the stent quickly during the operation. Despite the advantages of using stents to treat aortic dissection, there are still problems of great surgical difficulty, high risk, and inability to perform surgery promptly and quickly.

Although numerous improvements have been proposed to address one or more of the above problems, the complex and numerous stents need to be deployed due to the presence of more important branch arterial vessels at the aortic arch and abdominal aorta sites, resulting in an inefficient reduction in procedure time.

Disclosure of Invention

In view of the above, the main object of the present invention is to provide a stent which, once placed, can greatly alleviate the risk of arterial dissection or aneurysm at the aortic arch and/or abdominal aorta site, without the risk of branch artery blockage due to surgery, and which gains time for treatment.

To this end, a first aspect of the invention provides a stent. The stent comprises a stent body and a channel surrounded by the stent body, and is characterized in that the stent body is provided with a woven mesh structure, meshes of the mesh structure can be expanded and deformed, and the widest part of the mesh is at least 1mm when the mesh is not expanded.

The stent body of the stent is characterized by a high-elasticity braided net structure with high-elasticity expandable meshes, and the stent body can provide supporting force for a treatment part and simultaneously can not block the flow of blood completely. And each mesh can be expanded and deformed, so that a branch stent can be conveniently placed subsequently, the positioning problem of branch blood vessels does not exist, and the smooth blood flow of each branch artery in the operation is ensured.

The widest part of the mesh can have a width of 1-5 mm, preferably 2-3 mm.

According to one embodiment, the stent body may be woven from 0.05 to 0.5mm, preferably 0.1 to 0.4mm diameter filaments. The filaments may be one material selected from metals, medical polymers or biodegradable materials.

The metal material may be exemplified by: shape memory alloys (e.g., nitinol), cobalt chromium alloys, but are not limited thereto. Medical polymers may be listed as: nylon, polyester, polytetrafluoroethylene, polyacrylates, polyolefins, and the like, but are not limited thereto. The stent material of the invention is preferably nickel titanium alloy.

According to one embodiment, the mesh openings, when expanded, can allow passage of a stent delivery device having an outer diameter of at least 4.8 mm.

The stent of the present invention may have a length of 10 to 500mm, preferably 100 to 300mm, and a diameter of 25 to 55mm in a released state. The stent of the present invention having the above length and diameter ranges may be applicable to the treatment of any portion of the aorta. The particular size may vary depending on the particular treatment site.

According to one embodiment, the stent body of the stent of the invention has at least in part a coated region and an uncoated region, wherein the uncoated region corresponds to at least the site with a branched artery when the stent is released in the site to be treated.

The coated stent can have a quick relieving effect particularly on aortic aneurysm, and has a better effect on repair of aortic dissection.

According to one embodiment, the film may simultaneously have a developing function.

Because the part corresponding to the branch artery is not coated, the stent with the coating is also easy to deploy, can be quickly and simply placed, and ensures blood supply of the branch artery in the operation.

The film of the coating region may be formed of a bioaffinity polymer, and the present invention is not particularly limited thereto. Preferably, the film may be formed of one material selected from the group consisting of polytetrafluoroethylene, dacron, and polyurethane. Preferably, the film is polyurethane, in particular formed of thermoplastic polyurethane.

The film may have a thickness of 0.01 to 0.3mm, preferably 0.05 to 0.1 mm.

According to a specific embodiment, the stent has a proximal end and a distal end, wherein the proximal end has a diameter gradually decreasing from 40-55 mm to 30-38 mm, and the distal end has a substantially constant diameter of 28-38 mm. The stent of the embodiment is more suitable for treating the aortic arch part. The proximal end part with gradually changed diameter accords with the physiological anatomical structure of a human body, and can better support the aorta at the heart side.

In this embodiment, the proximal end portion may have a length of 10 to 100mm, preferably 10 to 20 mm. The distal end portion may have a length in a wide range of 20mm to 300mm, preferably 40 to 60mm, as required.

According to another embodiment, the stent is adapted for use in the visceral vascular area from the ascending aorta to the abdominal aorta including the aortic arch region, said stent having a coated area at least on the greater curvature side of the aortic arch, with the proviso that at least the region of the branch arteries corresponding to said greater curvature side has an uncoated area after release of said stent.

Because the part corresponding to the branch artery is not coated, the stent with the coating is also easy to deploy, can be placed quickly and simply, and ensures blood supply to the brain in the operation.

Specifically, the length of the stent with the coating part is 10-300 mm. The area of the film coating can be determined according to the specific requirements of the treatment. According to a preferred embodiment, the stent further has a development mark on the side of the major bend to facilitate positioning of the stent.

A second aspect of the invention provides a stent kit. The support kit comprises the support and at least one branch support.

The branch stent in the stent kit of the present invention is not particularly limited and may be any suitable branch stent conventionally used.

The stent kit of the invention reduces the risk of arterial rupture by placing the stent of the invention at the treatment site of the aorta in advance, thereby gaining time for further stent placement. The stent kit of the present invention may therefore further comprise, in addition to the branch stent, other stents for the aortic treatment site. These brackets may be any suitable brackets conventionally used. For example: a stent for an abdominal aorta with a bifurcated sub-channel, a stent for an iliac artery branch to maintain patency of an internal iliac artery (IBD), and the like, but not limited thereto.

A third aspect of the invention provides a stent delivery system. The stent delivery system includes a delivery catheter and a stent as described above, wherein the stent is retained in the delivery catheter in a releasable delivery configuration.

The stent delivery system of the present invention is not particularly limited with respect to the structure of the delivery catheter, and any suitable delivery catheter may be used for the delivery of the stent of the present invention, thereby constituting a stent delivery system together with the stent of the present invention.

According to one embodiment, the delivery catheter has a proximal end, a distal end, and a hollow cavity extending between the proximal and distal ends, the stent is releasably retained in the hollow cavity of the proximal end of the delivery catheter in a delivery configuration, wherein the delivery catheter includes at least one set of a first guidewire opening, a second guidewire opening, and a slit corresponding to the at least one opening of the stent, wherein:

the first guidewire opening being disposed on the delivery catheter wall corresponding to remaining in a delivery configuration

An opening on a stent in the delivery catheter;

the second guidewire opening is disposed at the distal end of the delivery catheter, and

the slit is arranged at the first guide wire opening and the delivery in the longitudinal direction of the delivery catheter

On the wall of the delivery catheter between the proximal ends of the catheter; and

the stent delivery system also includes at least one guidewire tube that is movably and removably disposed in the hollow cavity of the delivery catheter and extends between the first guidewire opening and the second guidewire opening.

According to one embodiment, the guidewire tubes may extend from the respective first guidewire openings through the respective openings on the stent into the interior space of the stent and further to the second guidewire openings when the stent is held in the hollow cavity of the delivery catheter in a delivery configuration.

According to one embodiment, the guide wire tube can be passed through the respective first guide wire opening and/or the second guide wire opening if required.

In the stent placement method described in detail below, the guidewire tube may be removed through the corresponding second guidewire opening after the guide guidewire is positioned at the desired treatment site. This facilitates subsequent stent release.

The stent delivery system of the embodiment is matched with the stent design of the invention, so that the rapid placement of the stent can be realized, the risk of blockage of a branch blood vessel in the stent placement is reduced, and valuable treatment time is won for a patient.

According to the invention, the guide wire tube can have an outer diameter of 2 to 6mm and an inner diameter of 1.7 to 5.8 mm.

According to one embodiment, the delivery catheter may further have a third guidewire opening disposed at the distal end of the delivery catheter, the third guidewire opening configured to allow a guidewire to pass through the hollow lumen of the delivery catheter through the third guidewire opening and guide the stent delivery system to a treatment site.

In the stent placement method described in detail below, a guidewire that has been previously positioned at the treatment site can be inserted into the delivery catheter at one end outside the patient's body and passed out through this third guidewire opening to guide the stent delivery system to the treatment site.

Further, a push rod is coaxially disposed within the hollow cavity of the delivery catheter, the push rod configured to operably couple with the delivery catheter to fully or partially release the stent when the push rod is manipulated.

According to a specific embodiment, the slit is configured to have a slit width allowing the passage of the guidewire tube.

As described in more detail below, upon release of the stent, the delivery catheter is moved relative to the stent, and the guidewire for positioning the branch vessel may remain in the slit and thus relatively immovable relative to the stent and the branch vessel.

The delivery catheter of the stent delivery system of the present invention may further comprise an inner catheter, and the stent may be disposed in a space between the delivery catheter and the inner catheter.

In a fourth aspect of the invention, there is also provided a method of treating or preventing aortic dissection or aortic aneurysm. The method comprises the step of placing the stent of the present invention at a treatment site of the aorta.

The method further comprises the step of placing a further aortic stent and/or a branch stent into at least one branch artery of the treatment site.

The treatment site is any artery with a branching artery. The artery may be a blood vessel, a lymphatic vessel, or the like. The treatment site according to the invention is in particular a blood vessel, in particular the aortic arch or the abdominal aorta.

According to one embodiment of the stent delivery system described above, the stent placement method comprises the steps of:

guiding a stent delivery system to the treatment site over a first guidewire;

extending a second guidewire through a guidewire tube from the first guidewire opening and guiding the stent delivery system such that the first guidewire opening on the delivery catheter is generally aligned with the branch vessel of the treatment site;

at least partially releasing the stent (and optionally, substantially aligning the coated region of the released stent with the branch vessel opening in the main vessel), and withdrawing the guidewire tube through a second guidewire opening;

placing a branch stent into the branch vessel by passing a branch stent delivery system through the hollow cavity of the delivery catheter and one mesh of the stent under guidance of the second guidewire;

withdrawing the first guidewire and the delivery catheter from the patient.

According to a specific embodiment, the first and/or second guide wire may be introduced into the stent delivery system by an adjustable bend catheter, a catcher (or snare) or a single bend catheter.

According to one embodiment, after the first guidewire opening is substantially aligned with the branch vessel of the treatment site, the guidewire tube may be moved to partially enter and remain in the branch vessel through the first guidewire opening. This ensures that the guidewire remains in the branch vessel when the stent is released.

According to a specific embodiment, the stent may be partially released step by step during the placement process, so as to place the branch stents one by one during the release process; or the stent can be released at one time, so that the branched stents are placed one by one after the stent is completely released.

After placement of each branch stent is completed, the respective second guidewire and the delivery system of that branch stent are withdrawn.

According to the method of the present invention, the guidewire may be introduced into the delivery catheter or guidewire tube from the same direction that the stent delivery system is introduced into the body, or may be introduced into the delivery catheter or guidewire tube from the opposite direction that the stent delivery system is introduced into the body.

According to one embodiment, the location of the stent and all branch stents is finally confirmed before the first guidewire and the delivery catheter are finally withdrawn from the patient. This confirmation may be made, for example, by a medical visualization device.

The stent can be quickly placed at the aorta part with the branch blood vessels by applying the woven stent with the expandable meshes, so that the risk of arterial dissection or aneurysm is quickly relieved, the risk that the stent blocks the blood flow of the branch arteries is avoided, and time is gained for subsequent further treatment. In addition, the high compliance and high elasticity mesh with large holding power of the stent of the invention, and the optional local coating film structure can rapidly and previously repair the aorta, reduce the operation risk and the technical difficulty of the operation, thereby gaining valuable treatment time for patients.

Drawings

FIG. 1 is a schematic view of a stent according to one embodiment of the present invention;

FIG. 2 is a schematic view of a stent according to another embodiment of the present invention;

FIG. 3 is a schematic view of a stent according to yet another embodiment of the present invention;

FIG. 4 is an enlarged partial view of a stent according to one embodiment of the present invention;

FIG. 5 is a schematic view of the stent of the embodiment of FIG. 4 being placed at a treatment site;

FIG. 6 is a schematic view of a stent delivery system that may be used to place a stent according to the present invention;

FIG. 7 is a partial top view of the outer catheter of the stent delivery system shown in FIG. 6 with a first guidewire opening; and

fig. 8 is a schematic view of a stent placement procedure at a treatment site using the stent delivery system of fig. 6.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments, and the technical solutions described in the embodiments of the present invention may be implemented in any combination without conflict. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.

Like reference numerals in the drawings refer to like parts. The shapes and dimensions of the various elements in the schematic drawings are illustrative only and are not to be construed as embodying the actual shapes, dimensions and absolute positions.

It is to be noted that, in the present invention, the terms "comprises", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion, so that a method or apparatus including a series of elements includes not only the explicitly recited elements but also other elements not explicitly listed or inherent to the method or apparatus.

It should be noted that the terms "first \ second \ third" referred to herein merely distinguish similar objects and do not represent a specific ordering for the objects, and it should be understood that "first \ second \ third" may be interchanged under certain ordering or sequence. It should be understood that "first \ second \ third" distinct objects may be interchanged under appropriate circumstances such that embodiments of the invention described herein may be practiced in sequences other than those illustrated or described herein.

To more clearly describe the structure of the delivery system of the present invention, the terms "proximal", "proximal" and "distal", "distal" are terms commonly used in the field of interventional medicine. The term "distal end" refers to the end (segment) that is distal from the heart during a surgical procedure, and the term "proximal end" refers to the end (segment) that is proximal to the heart during a surgical procedure.

According to a first aspect of the present invention, a stent is provided. Referring to fig. 1, a schematic view of a stent 10 according to one embodiment of the present invention is shown in a released state. The stent 10 has a stent body 11 and a channel 12. The stent body 11 is a mesh structure woven from a stent material.

The stent material may be metallic, such as shape memory alloys (e.g., nitinol), cobalt chromium alloys; medical polymers such as nylon, polyester, polytetrafluoroethylene, polyacrylates, polyolefins, and the like; or may be a biologically derived material or a biodegradable material. The stent material of the present invention is not particularly limited, and any suitable conventional material may be used. A preferred material for the inventive stent is nitinol.

The mesh structure constituting the stent body 11 of the present invention may be woven from the above-described wires or threads of the stent material in a conventional manner such that the stent 10 is self-expandable or balloon-expandable.

The diameter of the filaments from which the stent is woven may be 0.05-0.5 mm. Preferably, the diameter of the filament is 0.1-0.4 mm.

The mesh of the mesh structure of the stent body 11 has a widest dimension l (see fig. 4, which shows a partially enlarged stent) of 1 to 5mm, preferably 2 to 3mm, and more preferably 2.5 mm.

The stent body 11 of the stent of the present invention is entirely composed of a net structure having high elastic meshes. The net structure is woven so that each mesh is expandable.

Due to the structure, when the stent is released at a treatment part, on one hand, the stent can play a role in supporting the wall of a blood vessel, quickly repairs the damage of an aortic dissection and ensures that blood flow mainly passes through the true arterial cavity; on the other hand, the whole stent is formed by a reticular structure with expandable mesh holes, so that the branch artery can not be blocked, and the branch stent can be further introduced into the branch artery through the mesh holes. Thus, the mesh openings of the stent body 11 of the present invention are expanded to allow passage of at least a delivery system having an outer diameter of 14f (about 4.8mm) for placement of a branch stent in a branch artery. A portion of the branched stent remains in the channel of the stent 10 of the present invention, and the mesh may also function to fix the branched stent.

Fig. 2 shows a stent 20 according to another embodiment of the present invention. The holder 20 likewise has a holder body 21 and a channel 22 enclosed by the holder body 21. In this embodiment, the stent body 21 has a proximal end 28 and a distal end 29. Wherein the proximal end 28 has a diameter that tapers from the proximal end to the distal end, i.e., from a proximal diameter D1 to a proximal diameter D2. Wherein D1 can be in the range of 40mm to 55mm, and D2 can be in the range of 28mm to 38 mm. Preferably, D1 may be in the range of 45mm to 55mm, and D2 may be in the range of 30mm to 35 mm. The proximal end 28 may have a length in the range of 10 to 30mm, preferably 20 mm. The distal end 29 has a substantially constant diameter D2 and may have a length in the range of 20mm to 300mm, preferably 40mm to 60 mm.

The stent of this embodiment is suitable for treating a lesion in the aortic arch region because the blood vessel on the proximal side of the aortic arch region is relatively thick and tapers away from the heart. The bracket structure of the embodiment is beneficial to conforming to the physiological anatomical structure of a human body, is quick and simple, has short bow operation time, and reduces the occurrence of brain complications. The uniformly distributed high-elasticity meshes enable the branch stent to quickly select meshes with proper positions for deployment, reduce the operation on the superior arch artery and protect the cerebral vessels.

With further reference to fig. 3, a partially coated stent 30 is shown. The stent 30 is mainly used in the aortic arch region and has substantially the same structure as the stent 20 shown in fig. 2: the stent body 31 formed of a mesh structure encloses a channel 32. The stent body 31 includes a proximal end portion 38 and first and second

distal end portions

39a, 39 b. Wherein the second distal end 39b generally corresponds to the location of the three branch arteries of the aortic arch. The second distal end 39b has a membrane 33 corresponding to the major curvature of the aortic arch. An uncoated film area 34 remains in the middle of the film 33. The uncoated areas 34 may cover the open areas of the three branch arteries of the aortic arch site after the stent 30 is released at the aortic arch site.

Since the stent body of the stent of the present invention is formed of a net structure having high elasticity, the uncoated region 34 can form an open blood channel to all the branched arteries. The provision of such an overall open area as the uncoated region 34 enables the uncoated region 34 to be easily aligned with the ostium of the branch artery on the side of the greater curve during the placement of the stent 30, thereby quickly completing the placement of the stent.

The stent according to the embodiment of the present invention shown in fig. 1 to 3 can be placed quickly without aligning the openings of the stent with each branch artery one by one as in the conventional stent, thereby greatly reducing the difficulty of the operation and gaining time for the treatment of the patient.

Fig. 3 shows an embodiment in which the film is applied only to a part (large curved side) of a segment of the stent (second distal end portion 39 b). The stent of the present invention may be coated in sections or entirely except for the portion corresponding to the branched artery. The area of the coating film and the area of the coating film can be determined depending on the treatment site, the purpose of the treatment, and the like. For example, a substantially fully coated stent may be more advantageous for treating an aortic aneurysm.

The membrane 33 used in the stent of the present invention may be any suitable membrane for use in a stent coated with a membrane. There may be exemplified polytetrafluoroethylene, polyester, polyurethane (e.g., thermoplastic polyurethane), etc., but not limited thereto. Thermoplastic polyurethane films are preferably used.

The thickness of the film is not particularly limited, but is usually 0.01 to 0.3mm, preferably 0.05 to 0.1 mm.

The size of the uncoated region 34 varies from treatment site to treatment site, as long as the opening of the branch artery can be exposed and the positioning is easy and quick. Generally, to reduce the difficulty of the surgery, the size of the uncoated film area 34 may be set relatively large. Or in some cases, the portion corresponding to the branched artery is not coated at all. The shape of the uncoated film region 34 is also not particularly limited, and may be, for example, a rectangle, an ellipse, a circle, or the like. For aortic arch sites, the uncoated region 34 may have a length of about 20-40 mm and a central angle corresponding to about 120-180.

FIG. 4 shows an enlarged partial view of a stent according to one embodiment. The stent 40 of this embodiment is provided with a branch channel 45 in the channel 42. One end of the branch channel 45 is opened to a (non-coated) mesh 46 on the stent body 41, and the other end is opened to the inside of the channel 42 of the stent 40.

With further reference to fig. 5, an enlarged partial view of the stent 40 of fig. 4 positioned in the treatment site 90 is shown. Wherein the treatment site 90 has a branch artery 91. The stent 40 has been released at this location 90. Wherein the branch channel 45 is arranged with one end open to the mesh 46 and the mesh 46 is substantially near the opening of the branch artery 91. The branch stent 80 has been placed in the branch artery 91 with the other end thereof held in the branch channel 45. The branch channel 45 may not be perfectly aligned with the branch artery 91 as long as it is substantially near the opening of the branch artery 91. By expanding the mesh openings 46, the mesh openings can be generally aligned with the branch arteries 91, thereby facilitating placement and stabilizing of the branch stent.

The branch channels 45 may be woven from any of the stent materials described above and may expand to some extent as the mesh 45 expands.

The stent is suitable for being placed in advance in operations for treating aortic dissection and aortic aneurysm, the risk of aortic rupture is rapidly reduced, and the time for further treatment is won for patients. Accordingly, the present invention also provides a stent kit. The stent kit comprises the stent of the invention as described above and at least one branch stent.

The stent kit of the present invention may further comprise other stents for the treatment site of the aorta according to different treatment purposes. There may be mentioned: a stent for the abdominal aorta with a bifurcated sub-passage to facilitate placement of the left and right common iliac arteries further under the positioning of the sub-passage after release; stents (IBDs) for iliac artery branches are used to maintain patency of the internal iliac artery.

The stents of the present invention, as well as the individual stents in the stent kit, may be placed using any suitable stent delivery system in a conventional manner.

According to a specific embodiment, the stents and stent kits of the present invention may be placed using the stent delivery system described below.

Referring to fig. 6, there is shown a perspective schematic view of a stent delivery system 100 according to one embodiment of the present invention. The stent delivery system may be used to place the inventive stent and may be used to place the inventive stent in a stent kit and position each branch stent. It will be understood by those skilled in the art that the stent of the present invention may be placed by any suitable conventional stent delivery system and is not limited to this embodiment only

The stent delivery system 100 includes a delivery catheter 120 and a stent 110 of the present invention. Delivery catheter 120 includes an outer catheter 130 and a push rod 170 coaxially arranged along longitudinal axis X-X. The outer catheter 130 has proximal and

distal ends

131, 132 and a hollow cavity 133 extending therebetween. The hollow cavity 133 has a proximal end 138 and a distal end 139. The push rod 170 is disposed coaxially with the outer catheter 130 along the longitudinal axis X-X.

The stent 110 is releasably retained in the proximal end 138 of the hollow body 133 of the outer catheter 130 in a delivery configuration. The entire mesh structure of stent 110 is not shown in fig. 6, and only the uncoated mesh structure 114 designed to correspond to a portion of a branch vessel is exemplarily shown. As can be seen from the above description, the rest of the stent 110 shown in fig. 6 may have the same net structure as the net structure 114 or a partial or full coating film.

According to some embodiments, a mechanism (not shown) such as, but not limited to, a bump or the like may be provided on the inner wall of the proximal end 138 of the outer catheter 130 or at a suitable location of the push rod 170 to keep the stent 110 from moving.

The support 110 may be a support having any of the structures described above. In the present embodiment, the stent 110 has an uncoated film region 114.

Further, the proximal end portion of the outer catheter 130 of this embodiment is provided with a first guide wire opening 134 on the tube wall with respect to the uncoated film region 114 of the stent 110. A guidewire for guiding a delivery system of the branched stent may be passed through the opening to locate the branched artery according to a stent placement method described in detail below.

Similar to conventional delivery systems, outer catheter 130 can be moved along the X-axis relative to push rod 170 by manipulating push rod 170, thereby releasing stent 110. In this embodiment (see further fig. 8A-C), after the delivery system 100 is guided to the treatment site 90 over the first guidewire 181 and the uncoated region 114 of the stent 110 is generally aligned with the branch artery 91 over the second guidewire 182, the push rod 170 is manipulated to move the proximal end 138 of the outer catheter 130 toward the proximal end 131 to separate the proximal end 138 from the distal end 139 of the outer catheter 130, thereby releasing the stent 110 from its distal end.

In this embodiment, a slit 136 is provided on the outer catheter wall on one side of the first guide wire opening 132 in the moving direction when the outer catheter 130 releases the stent 110, so that the second guide wire 182 that has been positioned into the branch artery can be held in the branch artery 91 with the release of the stent 110 when the outer catheter 130 is moved to release the stent 110.

Fig. 7 illustrates a partial top view schematic of the proximal end 138 of the outer catheter 130 of the stent delivery system 100 of fig. 6. As shown in FIG. 7, upon release of the stent, the outer catheter 130 moves along the X-axis as indicated by the arrow. The wall of the catheter has a first guide wire opening 134, and a slit 136 is provided parallel to the X axis on the opposite side of the first guide wire opening 134 to the moving direction of the outer catheter 130 (i.e., on the side near the distal end). The width d of the slit 136 is at least such as to allow the second guide wire to move within the slit.

According to another embodiment, as opposed to the present embodiment described above, when stent 110 is released, outer catheter 130 is moved distally 132, with proximal end 131 moving away from head 160 of the delivery system, thereby releasing stent 110 from its proximal end. In this embodiment, the slit 136 may be disposed on a proximal side of the first wire opening 134.

According to other embodiments, the stent of the present invention may also be released starting from its middle part, such as described in chinese patent application CN110353866A, the entire content of which is incorporated herein by reference.

The stent release means that can be used in the present invention can be any suitable means known in the art, and the skilled person can appropriately position the slit according to the specific situation in order to complete the stent placement process described in detail below.

Still referring to fig. 6, the stent delivery system 100 also has a guidewire tube 150. The guidewire tube 150 has two

open ends

151 and 152, and a lumen extending therebetween. The guide wire tube 150 is disposed in the hollow cavity 133 of the outer catheter 130. One end 151 of which protrudes through the lumen of the stent 110 from a mesh of the uncoated region 114 thereof, but remains inside the lumen 133 of the outer catheter 130. The other end 152 of the guidewire tube 150 extends from the distal end 132 of the outer catheter 130. The end of distal end 132 may be provided with a second guidewire opening 135. In this embodiment, the other end 152 of the guidewire tube 150 extends out of the outer catheter 130 through the second guidewire opening 135.

The guidewire tube 150 of the present invention is movable within the hollow cavity 133 of the outer catheter 130 and is removable from the stent delivery system 100 through the second guidewire opening 135

With further reference to fig. 8A, in positioning the branch artery 91 over the second guidewire 182, the second guidewire 182 is introduced through the first guidewire opening 134 of the outer catheter 130 of the delivery system 100, passed through one end 151 of the guidewire tube 150, and passed out the other end 152 thereof. After positioning, the guidewire tube 150 can be moved such that the guidewire tube 150 extends out of the first guidewire opening 134 and partially into the branch artery 91 to further stabilize the second guidewire in the branch artery (see fig. 8B-C).

In this case, the width d of the slit 136 may be set to allow the guide wire tube 150 to move in the slit.

Referring to fig. 8C-E, when the stent is fully or partially released such that the uncoated region 114 of the stent 110 is generally at the branch artery, the guidewire tube 150 can be withdrawn through the second guidewire opening 135 while still retaining the second guidewire 182 in the branch artery 91. The branch stent delivery system 80 is then introduced over the second guidewire 182 at the branch artery 91 and the branch stent 70 is released.

The guide wire tube 150 may be a thin tube made of any suitable material and having a certain flexibility, and the outer diameter thereof may be in the range of 2 to 6mm, and the inner diameter thereof may be in the range of 1.7 to 5.8 mm. Usable materials are, for example: stainless steel, pebax (nylon elastomer), PTFE, PU, etc., but is not limited thereto.

According to other embodiments, the delivery catheter 120 may further have an inner catheter (not shown) arranged coaxially with the outer catheter, such that the stent is retained in the space between the outer and inner catheters. The guide wire tube is correspondingly arranged in the hollow cavity of the inner catheter. When the delivery system 100 has an inner catheter, the inner catheter is also provided with an opening corresponding to the outer catheter to facilitate passage of the guidewire tube. Optionally, the inner catheter may also have a slit that facilitates the guidewire tube to maintain its position during release of the stent.

According to other embodiments, the stent delivery system 100 of the present invention may further comprise a sleeve; or the inner catheter may be used as the pushing device and the push rod 170 omitted.

The stent of the present invention may have an outer diameter of about 25-55 mm and a length of about 10-500 mm in a released configuration. Thus, the delivery catheter (e.g., outer catheter) of the stent delivery system of the present invention typically has an outer diameter of about 4-10 mm (i.e., 12-30 Fr), and a length of about 400-1000 mm.

Several specific embodiments of the stent and stent delivery system of the present invention are shown above, but the embodiments of the present invention are not limited thereto. Those skilled in the art will appreciate that prior art stent configurations suitable for differently shaped or positioned arteries may be used with the stent of the present invention; in addition, by configuring the structure and connection manner of the inner catheter, the outer catheter, the push rod and/or the sleeve, a wider variety of stent release forms can be formed. Any form of release that facilitates stent positioning and placement, and the corresponding delivery system configuration, is within the scope of the present invention, consistent with the spirit of the present invention.

A simple method of placement of a stent according to the present invention may be simply introducing the stent of the present invention into a treatment site in a blood vessel by a delivery system using conventional methods, and then releasing it. Since the stent of the present invention is constituted by an expandable mesh structure or has a large uncoated area at a portion corresponding to a branch vessel, there is no fear of whether or not the portion corresponding to the branch vessel has an opening even if the subsequent treatment requires further placement of the branch stent in the branch vessel. The placement of the branch stent can be performed by only appropriately expanding the meshes of the branch vessel site.

The placement of the inventive stent and the method of branching the stent at a treatment site, particularly a site having a branching artery, using the inventive stent delivery system is described in detail below with reference to fig. 8.

In general, fig. 8 specifically illustrates a method of using a stent delivery system comprising the stent of the present invention with a coated stent and a mechanism disposed in the stent delivery system to facilitate positioning of a second guidewire (the mechanism comprising, inter alia, first and second guidewire openings and slits disposed on an outer catheter, and a guidewire tube). According to the stent placement method, the positioning of the stent can be completed quickly, the difficulty of the operation is reduced, the operation process is accelerated, and the operation risk is reduced. As shown in fig. 8, a process for placing a stent using the stent delivery system shown in fig. 6 is schematically illustrated.

Referring to fig. 8A, a treatment site 90 is schematically shown, in which there is a branch artery 91. The first guidewire 181 has been positioned at the treatment site 90 and the second guidewire 182 has been positioned at the branch artery 91. As shown in fig. 8A, the first guidewire 181 has been introduced into the hollow cavity 133 of the outer catheter 130 through the head 160 of the stent delivery system 100 and exits the distal end 132 of the outer catheter 130; and the second guidewire 182 has also been introduced into the guidewire tube 150 through the first guidewire opening 134 of the outer catheter 130 and exits out the distal end.

As shown in fig. 8B, the stent delivery system 100 is guided to the treatment site 90 over the first and

second guide wires

181, 182 with the first guide wire opening 134 of the outer catheter 130 generally aligned with the branch artery 91. At this point, the uncoated region 114 of the stent 110, still held in the delivery configuration within the hollow cavity 133 of the outer catheter 130, is also generally aligned with the branch artery 91. Since the uncoated region 114 is significantly larger than the opening of the branch artery, it is sufficient to align the first guidewire opening substantially with the branch artery 91, thereby greatly reducing the difficulty of the procedure.

As described above, the outer catheter 130 is pushed proximally 131 by operating the push rod 170 of the stent delivery system 100, so that its proximal end 138 is moved away from the distal end 139 and proximally, thereby releasing the stent 110 from its distal end to its proximal end (fig. 8C).

According to a specific embodiment, after the stent delivery system 100 is guided to the appropriate location, the guidewire tube 150 can be moved so that its one end 151 passes out of the second guidewire opening 134 along the second guidewire and partially into the branch artery 91 to ensure that the second guidewire 182 remains in the branch artery 91 at all times during release of the stent (fig. 8C). This further ensures that the stent is released in the desired predetermined position.

Since the slit 136 is provided in advance on the side of the second guide wire opening 134 of the outer catheter 130 near the distal end, the second guide wire 182 or the guide wire tube 150 can enter the slit 136 when the outer catheter 130 moves toward the proximal end, and thus can be kept from moving relative to the branch artery.

After the stent 110 is fully released, the guidewire tube 150 is withdrawn from the second guidewire opening 135. The branched stent delivery system 80 is then introduced into the hollow lumen 133 of the outer catheter 130, guided by a second guidewire, and further into the lumen 113 of the stent 110 and through one of the mesh openings of the uncoated film region 114 into the branched artery 91 (fig. 8D).

Before introducing the branch stent delivery system 80, the mesh through which the second guidewire 182 passes may be suitably enlarged so that the branch stent delivery system 80 may easily pass. The method of enlarging the mesh is not particularly limited. The mesh may be enlarged, for example, by a balloon or a high holding force stent.

Finally, as shown in fig. 8E, the branch stent 70 is released in place and the delivery catheter of the branch stent delivery system 80 and the second guidewire are withdrawn.

For treatment sites with multiple branch arteries, stents with multiple openings and corresponding delivery systems with multiple guide wire tubes and openings can be used, as can stents with one opening.

When all the branch stents have been placed, the placement location is optionally confirmed again by intraoperative visualization and the stent delivery system 100 and first guidewire are withdrawn.

The stent placement method of the present invention is described above by taking a specific stent placement process as an example. One skilled in the art will appreciate that other placement methods may be used depending on the treatment site and depending on the actual condition of the patient.

For example, the entire stent delivery system may be introduced into the body from the femoral artery, or a branched stent delivery system may be introduced from the superior cervical arch artery or the brachial artery. The guide wire may also be introduced into the treatment site from the femoral artery, the superior cervical arch artery, or the brachial artery.

In addition, the stent delivery system and guidewire may be introduced into the treatment site in the same path or in opposite paths. For example, unlike the manner described above in fig. 8, a guidewire may be introduced into the treatment site from the upper carotid artery and the guidewire may be introduced into the delivery system using a guidewire catcher, but is not limited thereto.

Methods for these variations are well known to those skilled in the art and will not be described in detail herein.

The branched stent delivery system and the branched stent suitable for use in the present invention are not particularly limited. Any conventional suitable stent delivery system and stent may be used for the branched stent delivery system. The method of guiding a guide wire is used as an example of placement of the branch stent. An adjustable bend catheter may also be used as a branch stent delivery system.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents made by the contents of the present specification and drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A stent comprises a stent body and a channel enclosed by the stent body, and is characterized in that the stent body is of a woven mesh structure, the meshes of the mesh structure are expandable and deformable, and the widest part of the meshes is at least 1mm when the mesh structure is not expanded.

2. The stent according to claim 1, wherein the stent body is woven from 0.05 to 0.5mm, preferably 0.1 to 0.4mm diameter filaments, which are one material selected from metals, medical polymers or biodegradable materials.

3. The stent of claim 1, wherein the mesh openings, when expanded, allow passage of a stent delivery device having an outer diameter of at least 4.8 mm.

4. The stent according to claim 1, wherein the stent has a length of 10 to 500mm, preferably 100 to 300mm, and a diameter in a released state of 25 to 55 mm.

5. The stent of claim 1, wherein the stent body has at least in part a coated region and an uncoated region, wherein the uncoated region corresponds to at least the site having a branched artery when the stent is released in the site to be treated.

6. The stent according to claim 5, wherein the membrane of the coating region is formed of a biocompatible polymer, preferably one selected from the group consisting of polytetrafluoroethylene, dacron, and polyurethane.

7. The stent of claim 5, wherein the membrane has a thickness of 0.01 to 0.3 mm.

8. The stent of claims 1-7, wherein the stent has a proximal end and a distal end, wherein the proximal end has a diameter that gradually decreases from 40-55 mm to 30-38 mm, and the distal end has a substantially constant diameter of 28-38 mm.

9. The stent of claim 8, wherein the proximal end has a length of 10-100 mm and the distal end has a length of 20-300 mm.

10. The stent according to claim 9, wherein said stent is adapted to a visceral vessel area from an ascending aorta to an abdominal aorta including an aortic arch region, said stent having a coated region at least at a great curvature side of an aortic arch, with the proviso that at least a portion corresponding to a branch artery at said great curvature side has an uncoated region after release of said stent,

preferably, the length of the stent with the coating film part is 10 to 300mm,

more preferably, the stent further has a development mark on the side of the major bend.

11. A stent kit, the stent kit comprising:

a stent according to any one of claims 1 to 10; and

at least one branch stent for branching a blood vessel,

preferably, the stent kit further comprises other stents for the aortic treatment site.

12. A stent delivery system comprising a delivery catheter and a stent according to any one of claims 1 to 10, wherein the stent is retained in the delivery catheter in a releasable delivery configuration.