Stents, Stent Delivery Systems, and Kits

Abstract

The present application relates to stents, stent delivery systems and kits. The main stent delivery system of the present invention comprises: a main delivery catheter and a main stent, wherein the main delivery catheter comprises an outer catheter and an inner catheter arranged coaxially, wherein the outer catheter has a proximal end and a distal end, and has a first hollow cavity, and the inner catheter extends in the first hollow cavity of the outer catheter; and the main stent is releasably retained in the first hollow cavity between the outer catheter and the inner catheter at the proximal end of the main delivery catheter in a delivery configuration, characterized in that the main stent is a bare stent, having a main stent body and a main channel surrounded by the main stent body, wherein at least one opening is arranged on the main stent body. It also relates to a kit and a main stent comprising the main stent delivery system. The delivery system and the kit are used in the aorta to accurately locate and quickly place the main stent and branch stents, and the main stent can be produced in a standardized manner.

Description

Technical Field

[0001] The present invention relates to stents, stent delivery systems and kits, and more particularly to stents used in vessels with branched vessels, especially the aorta, and systems and methods for delivering and placing stents. Background Art

[0002] The arterial wall is composed of the intima, media, and adventitia that fit tightly together. When the inner wall of the artery is partially damaged, the media of the arterial wall gradually peels off under the strong impact of arterial blood flow, allowing blood to enter between the media and adventitia of the blood vessel wall, forming two true and false cavities. The most common is aortic dissection. Aortic dissection weakens the arterial wall and is at risk of rupture at any time. Once the dissection ruptures, it will cause the patient's death within a few minutes.

[0003] Aortic aneurysm is an abnormal dilation of the aorta. A rupture of an aortic aneurysm can be fatal.

[0004] Therefore, early diagnosis and timely treatment of aortic dissection and aortic aneurysm are very necessary.

[0005] In cases where aortic dissection and aortic aneurysm involve the aortic arch, descending aorta and / or abdominal aorta, covered stents can be used to isolate the damaged area. The advantages of covered stent treatment are less trauma, less bleeding, faster recovery, and lower mortality. Compared with traditional open surgery, it reduces the incidence of perioperative complications.

[0006] The convex side of the aortic arch has three major branch arteries from the heart end, namely the brachiocephalic trunk (also known as the innominate artery, which branches into the right common carotid artery and the right subclavian artery), the left common carotid artery and the left subclavian artery. There are more branch vessels on the abdominal aorta, such as the middle adrenal artery, renal artery, celiac trunk, superior mesenteric artery, inferior mesenteric artery, inferior phrenic artery, lumbar artery, and middle sacral artery, and it branches into the left and right iliac arteries at the end.

[0007] During stent placement surgery, important branch arteries, especially the brachiocephalic trunk, left common carotid artery, left subclavian artery, left and right renal arteries, celiac trunk and superior mesenteric artery cannot be blocked by the stent, otherwise it will cause serious complications or even death to the patient. Therefore, the conventional practice is to make a hole in the aortic stent corresponding to the important branch artery, and then release the stent after aligning the opening with the branch artery. This increases the difficulty of the operation and requires experienced surgeons to perform it. Moreover, if the positioning is inaccurate during placement, or the stent shifts during the release process, blocking important branch blood vessels will cause serious consequences.

[0008] In addition, the relative position of the branch arteries varies from person to person, especially the relative position of the branch arteries on the abdominal aorta is often different for different people. This requires the position of the branch blood vessels on the aorta of each patient to be measured in advance and customized from the stent manufacturer. Even so, due to movement or different postures, the position of the blood vessels will shift, and during surgery, the specific position of the blood vessels may deviate from the opening position of the customized stent. To avoid this situation, experienced surgeons will open holes in the stent during surgery (pre-opening windows or in situ opening windows). However, this practice is often not recognized by stent manufacturers.

[0009] Since aortic dissection may rupture at any time and the branch arteries cannot be blocked for a long time, whether the patient can undergo surgery as soon as possible and whether the stent can be placed quickly during the operation is a matter of life and death. Although there are many advantages to using covered stents to treat aortic dissection, there are still problems such as high difficulty and risk of surgery and the inability to perform surgery in a timely and rapid manner.

[0010] The problem of being able to accurately place a stent in an aortic vessel with branching vessels has received some attention and some solutions have been proposed.

[0011] For example, Chinese patent application No. CN108158703A discloses a delivery system and method. The delivery system has one or more openings on the side wall of the stent and the corresponding position of the delivery catheter, and a guide wire tube is removably received at the opening. When placing the stent, the treatment position in the aorta is first determined by a guide wire, and then the position of the branch artery is determined by at least one other guide wire; the guide wire that has determined the position of the branch artery is passed through the guide wire tube and through the opening, and then the guide wire tube is removed; the stent is guided to the treatment position by the guide wire that has determined the treatment position of the aorta and the guide wire that has determined the position of the branch artery, and the stent is released. In this method, the release position of the stent can be more accurately determined by at least two guide wires at the same time. However, the delivery system and method still cannot solve the problem of accurate opening alignment for multiple branches. For the case of multiple branches, for example, there are three branch arteries at the aortic arch, and at least four branch arteries are to be opened in the abdominal aorta, and multiple guide wires are required to be positioned at the same time before the stent is placed, which increases the complexity of the operation, and thus the operation cannot be performed quickly. Summary of the invention

[0012] In view of this, the main purpose of the present invention is to provide a stent, a stent delivery system and a stent placement method that can solve or improve at least one of the above-mentioned problems, especially to provide a stent delivery system that can be accurately positioned for the aortic arch and abdominal aorta, a stent placement method that can accurately position and quickly place the stent, and a standardizable stent for this area.

[0013] To this end, the first aspect of the present invention provides a main stent delivery system. The main stent delivery system comprises: a main delivery catheter and a main stent, wherein the main delivery catheter comprises an outer catheter and an inner catheter arranged coaxially, wherein the outer catheter has a proximal end and a distal end and has a first hollow cavity, the inner catheter extends in the first hollow cavity of the outer catheter; and the main stent is releasably retained in the first hollow cavity between the outer catheter and the inner catheter at the proximal end of the main delivery catheter in a delivery configuration,

[0014] It is characterized in that the main stent is a bare stent, comprising a main stent body and a main channel surrounded by the main stent body, wherein at least one opening is arranged on the main stent body.

[0015] Specifically, the at least one opening is 2 to 6 openings, preferably 3 or 4 openings.

[0016] The main stent delivery system of the present invention uses a bare stent with an opening, thereby achieving gradual release, making it possible to place the main stent and the branch stent at the same time, thereby at least partially solving the above-mentioned problem and reducing surgical risks.

[0017] According to the present invention, when the main stent is in the released configuration, the opening may be configured such that the relative position of the opening on the main stent is substantially consistent with the position of the opening of the branch vessel on the main vessel of the treatment site.

[0018] According to the specific time implementation method, the main vessel at the treatment site can be the aortic arch or the abdominal aorta, wherein the branch vessels on the aortic arch are the brachiocephalic trunk, the left common carotid artery and the left subclavian artery, and the branch vessels on the abdominal aorta are the left renal artery, the right renal artery, the celiac trunk and the superior mesenteric artery.

[0019] That is, the main stent in the delivery system of the present invention may be a stent suitable for the aortic arch or the abdominal aorta, and thus may have three openings or four openings, respectively.

[0020] According to one embodiment, a sub-channel corresponding to the opening may be provided in the main channel of the main stent, and the sub-channel is used to guide and hold the branch stent to be placed in the branch vessel.

[0021] The sub-channel may be formed by an additional sub-channel member and fixed inside the main stent body, or the sub-channel may be formed by a portion of the main stent body.

[0022] According to a first embodiment of the present invention, the distal end of the outer catheter may be composed of a first proximal end segment and a second proximal end segment, and the first proximal end segment and the second proximal end segment are configured to be relatively distant from each other along the longitudinal axis of the main delivery catheter, thereby allowing the main stent releasably maintained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be released sequentially from the middle to both ends.

[0023] The length ratio of the first proximal end segment to the second proximal end segment may be (1:9) to (9:1), preferably (3:7) to (7:3), and more preferably (4:6) to (6:4).

[0024] The length of the first proximal end segment may be 1 to 20 cm, or the length of the second proximal end segment may be 1 to 10 cm.

[0025] According to a specific embodiment, the first proximal end section of the outer catheter is fixedly connected to or integrally formed with the inner catheter at the proximal end.

[0026] According to another specific embodiment, the inner catheter may have a second hollow cavity, and the main delivery catheter may also include a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod may be fixedly connected to the first proximal end segment of the outer catheter at the proximal end or formed integrally therewith.

[0027] According to a second embodiment of the present invention, the proximal end and the distal end of the outer catheter can be relatively distant from each other along the longitudinal axis of the main delivery catheter, thereby allowing the main stent releasably maintained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be gradually released from the distal end to the proximal end.

[0028] According to a specific embodiment, the proximal end of the outer catheter may be fixedly connected to the proximal end of the inner catheter or formed integrally therewith.

[0029] According to another specific embodiment, similarly, the inner catheter may have a second hollow cavity, and the main delivery catheter may also include a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod is fixedly connected to the outer catheter at the proximal end or formed integrally therewith.

[0030] According to a third embodiment of the present invention, the outer catheter is capable of moving relative to the inner catheter along the longitudinal axis of the main delivery catheter toward the distal end, thereby allowing the main stent releasably retained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be gradually released from the proximal end to the distal end.

[0031] Specifically, the inner catheter may have a second hollow cavity, and the main delivery catheter also includes a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod is fixedly connected to the inner catheter at the proximal end or formed integrally therewith.

[0032] The main delivery catheter of the present invention typically has an outer diameter of about 5 to 10 mm, preferably about 5 to 8 mm.

[0033] Optionally, the outer wall of the proximal end of the inner catheter may be provided with a component for preventing the main stent from moving. For example, the component for preventing the main stent from moving may be protrusions arranged at both ends of the proximal end of the inner catheter.

[0034] Optionally, the main stent delivery system may also have a main stent release limiting member arranged at the proximal end and the distal end of the main stent, and the main stent release limiting member may be configured to keep the proximal end and / or the distal end of the main stent in a delivery configuration before the proximal end and / or the distal end of the main stent are completely released.

[0035] The second aspect of the present invention provides a multi-stent delivery system kit for a vessel with branches, wherein the kit comprises a main stent delivery system of the present invention and at least one branch stent delivery system.

[0036] The branch stent delivery system that can be used in the multi-stent delivery system kit of the present invention is not particularly limited and can be any suitable stent delivery system. According to a preferred embodiment, the branch stent delivery system may include an adjustable curved catheter and a branch stent that is releasably retained in the adjustable curved catheter in a delivery configuration. The branch stent with an adjustable curved catheter does not require guidewire guidance, thereby further speeding up the placement of the stent and saving operation time.

[0037] The branch stent that can be used in the present invention is not particularly limited, and can be any suitable stent, for example, the branch stent can be a bare stent or a coated stent.

[0038] The third aspect of the present invention provides a bare stent. The bare stent of the present invention is suitable for a main vessel with a branch vessel, and is particularly suitable for an aorta with a branch artery. The bare stent has a stent body and a main channel surrounded by the stent body, wherein at least one opening is arranged on the stent body.

[0039] The at least one opening is 2 to 6 openings, preferably 3 or 4 openings.

[0040] Specifically, when the bare stent is in a released configuration, the opening is configured so that the relative position on the bare stent is substantially consistent with the position of the opening of a branch vessel on a main vessel at a treatment site on the main vessel.

[0041] The opening position on the main stent of the present invention does not need to be precisely matched with the opening position of the branch vessel in the treatment site of the patient. Since the present invention uses a bare stent, and since the stent body is formed by weaving fine filaments, the stent body has a certain deformation ability, it is sufficient as long as the opening position on the main stent roughly matches the opening position of the branch vessel in the treatment site. When a certain opening on the main stent is in a semi-released state, the branch stent can be placed by utilizing the deformable behavior of the main stent, so that the branch stent cannot be placed or the branch vessel is not blocked.

[0042] As mentioned above, the main stent of the present invention is particularly suitable for the case where the main vessel of the treatment site is the aortic arch or the abdominal aorta, wherein the branch vessels on the aortic arch are the brachiocephalic trunk, the left common carotid artery and the left subclavian artery, and the branch vessels on the abdominal aorta are the left renal artery, the right renal artery, the celiac trunk and the superior mesenteric artery.

[0043] According to one embodiment, a sub-channel corresponding to the opening may be provided in the main channel of the bare stent, and the sub-channel is used to guide and hold the branch stent to be placed in the branch vessel.

[0044] The two ends of the sub-channel respectively have a first opening and a second opening, wherein the first opening is the corresponding opening on the bare stent, and the second opening is arranged in the main channel of the bare stent or outside the main channel of the bare stent. The branch stent delivery device can sequentially pass through the second opening and the first opening of the sub-channel to enter the main vessel, and then enter the corresponding branch vessel to determine whether to branch the stent.

[0045] The provision of the sub-channel is beneficial for guiding the branch stent delivery system into the corresponding opening, and is also beneficial for the branch stent to be firmly held in the corresponding branch vessel and to maintain its relative position with the main stent without movement.

[0046] The sub-channel may be formed by an additional sub-channel member and fixed inside the main stent body, or the sub-channel may be formed by a portion of the main stent body.

[0047] The stent body of the bare stent and the sub-channel component may be respectively composed of braided metal wires or medical polymer wires, and the materials constituting the stent body of the bare stent and the sub-channel component may be the same or different.

[0048] The bare stent is self-expandable or balloon-expandable.

[0049] The bare stent typically has a length of 10-400 mm and an outer diameter of 20-60 mm.

[0050] The bare stent is used in the aortic arch or the abdominal aorta and is a standard stent. Since the opening on the bare stent of the present invention does not need to be precisely positioned for each patient, it can be industrially mass-produced as a standard stent, and the problem of delayed surgery due to preoperative customization or product quality risks caused by in-situ openings can be avoided.

[0051] A fourth aspect of the present invention provides a method for stent placement at a treatment site in a main vessel with branch vessels. The method comprises the following steps:

[0052] a. guiding the main stent delivery system to the treatment site;

[0053] b. gradually releasing the main stent to expose at least one opening on the main stent body, and adjusting the main stent delivery system so that the opening is located at the opening of the corresponding branch vessel in the main vessel at the treatment site;

[0054] c. releasing the main stent into one end of the branch stent;

[0055] d. guiding at least one branch stent delivery system through one end of the released main stent, into the lumen of the main stent, and through the opening into the branch vessel;

[0056] e. Adjusting the branch stent delivery system to an appropriate position and releasing the branch stent;

[0057] f. Repeat steps b to e to complete the placement of all branch stents;

[0058] g. Completely release the main support.

[0059] According to one embodiment, in step b, two openings on the main stent body may be exposed simultaneously, and in step d, two branch stent delivery systems may be introduced simultaneously, and in step e, the release of the two branch stents may be completed simultaneously.

[0060] According to the method of the present invention, the branch stent delivery system can be introduced into the branch vessel through the sub-channel of the main stent. In this embodiment, after the branch stent is released, a part of it can remain in the sub-channel.

[0061] The main stent delivery system and the branch stent delivery system can be respectively guided to appropriate locations in the vessel through guide wires.

[0062] According to one embodiment, the branch stent delivery system may use an adjustable bend catheter.

[0063] The method is used to place a stent in the aorta, in particular the aortic arch or the abdominal aorta.

[0064] According to one embodiment, in step b, the main stent is released from the middle portion of the main stent to both ends in sequence. Specifically, the main stent is first released from the middle portion of the main stent to its distal end, or conversely, the main stent is first released from the middle portion to its proximal end.

[0065] According to another embodiment, in the step b, the main stent is released from the distal end of the main stent toward the proximal end.

[0066] According to yet another embodiment, in the step b, the main stent is released from the proximal end of the main stent toward the distal end.

[0067] According to the method of the present invention, in step c, the end of the main stent to be introduced into the branch stent may be the distal end of the main stent, or may be the proximal end of the main stent, preferably the distal end of the main stent.

[0068] In step c, the release state of the main stent is further adjusted so that the exposed opening of the main stent body is in a semi-released state, that is, the exposed opening is not attached to the inner wall of the vessel.

[0069] According to a specific embodiment, the vertical distance d between the center point of the opening and the inner wall of the blood vessel is greater than or equal to 3 mm, preferably greater than or equal to 5 mm, and more preferably greater than or equal to 8 mm.

[0070] If the opening is over-released (for example, causing the vertical distance between the center point of the opening and the inner wall of the vessel to be too small), the released portion of the main stent can be retracted between the inner and outer catheters by adjusting the outer catheter and / or the inner catheter.

[0071] After the stent is placed, the stent delivery system is promptly withdrawn.

[0072] The fourth aspect of the present invention provides a method for treating or preventing vascular diseases, especially aortic dissection and aortic aneurysm. The method comprises the step of placing at least a main stent at a treatment site of a patient's aorta using the stent placement method of the present invention.

[0073] The method further comprises the step of sequentially placing branch stents in the branch arteries during the process of placing the main stent.

[0074] The treatment site is the aorta with branched arteries, in particular the aortic arch or the abdominal aorta.

[0075] The main stent delivery system for treating aortic dissection or aortic aneurysm of the present invention can quickly release the main stent in the aorta with branch vessels and place the branch stent in the branch vessels by using the main stent that can be gradually released, so that the main stent and the branch stent can be placed quickly. The system and method save valuable time for patients and reduce the difficulty and risk of surgery.

[0076] Furthermore, the main stent delivery system of the present invention uses a bare stent with an opening, which not only does not significantly block the blood flow during the gradual release, but also utilizes the deformability of the bare stent to place the branch stent in a semi-released state, thereby avoiding the adverse effects of inaccurate openings on the blood flow of the branch vessels and the placement of the branch stents. By using the main stent delivery system and method of the present invention, it is not necessary to make precise openings on the main stent for each patient, thereby allowing the main stents used in the same treatment area to be mass-produced. More importantly, it saves the steps of customization or intraoperative openings according to different patients, saving precious time for patients and avoiding unnecessary trouble. In addition, it also reduces the requirements for the surgeon's experience, greatly reducing the impact of the main stent placement on the blood flow of the branch vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 A schematic diagram of a main stent delivery system according to a first embodiment of the present invention;

[0078] Figure 2 for Figure 1 A schematic diagram of a main stent delivery system of a variation of the illustrated embodiment;

[0079] Figure 3 A schematic diagram of a main stent delivery system according to a second embodiment of the present invention;

[0080] Figure 4 A schematic diagram of a main stent delivery system according to a third embodiment of the present invention;

[0081] Figure 5 A schematic diagram of a main support according to an embodiment of the present invention;

[0082] Figure 6 A partial schematic diagram of a main support according to a specific embodiment of the present invention;

[0083] Figure 7 A partial schematic diagram of a main support according to another specific embodiment of the present invention;

[0084] Figure 8 A schematic diagram of a main stent for the abdominal aorta according to an embodiment of the present invention;

[0085] Fig. 9A schematic diagram of a main stent for an aortic arch (A1, A2) and an abdominal aorta (B1, B2) according to a specific embodiment of the present invention;

[0086] Fig.10 A schematic diagram of a method for placing a main stent and a branch stent in an aorta using the multi-stent delivery system kit of the present invention according to one embodiment;

[0087] Fig.11 A schematic diagram of a method for placing a main stent and a branch stent at an aortic arch using a multi-stent delivery system kit according to a specific embodiment of the present invention;

[0088] Fig.12 The figure is a schematic diagram of a method for placing a main stent and a branch stent in the abdominal aorta using the multi-stent delivery system kit of the present invention according to another specific embodiment. DETAILED DESCRIPTION

[0089] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. In the absence of conflict, the technical solutions recorded in the embodiments of the present invention can be implemented in any combination. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0090] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0091] The same reference numerals in the drawings refer to the same components. The shapes and sizes of the components in the schematic drawings are for illustration only and should not be considered to reflect the actual shapes, sizes and absolute positions.

[0092] It should be noted that, in the present invention, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a method or apparatus including a series of elements includes not only the elements explicitly stated, but also includes other elements not explicitly listed, or also includes elements inherent to the implementation of the method or apparatus.

[0093] It should be noted that the terms "first\second\third" involved in the embodiments of the present invention are only used to distinguish similar objects, and do not represent a specific order for the objects. It is understandable that the specific order or sequence of "first\second\third" can be interchanged where permitted. It should be understood that the objects distinguished by "first\second\third" can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0094] In order to more clearly describe the structure of the delivery system of the present invention, the terms "proximal end" and "distal end" are commonly used in the field of interventional medicine. The "distal end" refers to the end away from the heart during the surgical operation, and the "proximal end" refers to the end close to the heart during the surgical operation.

[0095] Primary stent delivery system

[0096] The present invention provides a novel main stent delivery system, particularly for use in situations where the treatment site is in a vessel with branches, such as for treating aortic diseases that often involve branch arteries, such as aortic dissection or aortic aneurysm in the aortic arch or abdominal aorta.

[0097] refer to Figure 1 , which shows a schematic diagram of a main stent delivery system 10 of a specific example in the first embodiment. According to this embodiment, the main stent can be released from the middle to both ends in sequence.

[0098] like Figure 1 As shown, the main stent delivery system 10 includes a main delivery catheter 20 and a main stent 50. The main delivery catheter 20 includes an outer catheter 30 and an inner catheter 40 coaxially arranged along the longitudinal axis XX. The main delivery catheter 20 has a distal end 23 and a proximal end 22, as well as a proximal end 24 and a distal end 26. The main delivery catheter 20 has a hemostatic valve 25 at the distal end 23. The outer catheter 30 has a first hollow cavity 33. The inner catheter 40 is coaxially arranged with the outer catheter 30 along the longitudinal axis XX and has a second hollow cavity 43. According to another example, the inner catheter 30 can be solid, such as a rod. The inner catheter 40 extends in the first hollow cavity 33 of the outer catheter 30 and further extends from the distal end port 35 of the outer catheter 30. In some embodiments, the portion of the inner catheter extending from the distal end port 35 can be formed as a rigid pusher 70. In the proximal end 24 of the main delivery catheter 20, the main stent 50 is releasably held in the first hollow cavity 33 between the outer catheter 30 and the inner catheter 40 in the delivery configuration. A limiting mechanism (not shown) that limits the movement of the main stent 50 relative to the inner and outer catheters during the release process may be appropriately provided on the outer wall of the inner catheter. For example, a protrusion may be provided near the end of the main stent 50. The limiting mechanism may be those conventionally used in the art, and there is no particular limitation in the present invention.

[0099] According to the delivery system 10 of this embodiment, the outer catheter 30 is constructed as two separable parts 31 and 32 in the middle part corresponding to the proximal end 24 of the main delivery catheter 20. As shown in the figure, the first proximal end section 31 of the outer catheter 30 is fixedly connected to the inner catheter 40 at its proximal end through a connector 60. Through the connector 60, the first proximal end section 31 of the outer catheter can move integrally with the inner catheter 40. The second proximal end section 32 of the outer catheter 30 is integrated with the distal end of the outer catheter. By operating the pusher 70, while keeping the position of the stent 50 relative to the blood vessel unchanged, the outer catheter can be pulled toward the distal end, so that the second proximal end section 32 moves toward the distal end relative to the first proximal end section 31, thereby partially releasing the distal end portion of the stent 50.

[0100] The specific structure and connection method of the main delivery catheter are not limited to the above examples, and any suitable connection method can be used to achieve the above-mentioned release of the main stent, which will not be described in detail here. The following specific embodiments are also described only by the connection method shown in the drawings as an example, but those skilled in the art should know that any structure and connection method of the main delivery catheter that can achieve the release method of the main stent of the present invention are within the scope of the present invention.

[0101] See also Figure 1 , which shows the state where a portion of the stent 50 is exposed after the second proximal end section 32 of the outer catheter is pulled toward the distal end for a distance.

[0102] The present invention has no particular limitation on the connector 60, and it can be any suitable connector, such as a threaded connection, a screw, a buckle, etc., but not limited thereto. According to an alternative embodiment, the inner catheter 40 and the first proximal end section 31 of the outer catheter can be formed integrally.

[0103] Figure 1 The main stent delivery system 10 shown is used to place an aortic stent 50 into the aorta, particularly into the aortic arch or the abdominal aorta with branched arterial vessels. The delivery system allows the main stent 50 to be released from the middle portion to both sides.

[0104] As can be seen from the stent placement method to be described in detail below, using the delivery system 10, the second proximal end segment 32 of the outer catheter can be pulled away from the first proximal end segment 31, thereby releasing the distal end portion of the stent 50. Then, by pushing the pusher 70, the first proximal end segment 31 of the outer catheter is moved toward the proximal end, so that the proximal end portion of the stent 50 is gradually released. An alternative method is to first push the first proximal end segment 31 of the outer catheter toward the proximal end to gradually release the proximal end portion of the stent 50, and then pull the distal end 35 of the outer catheter to make the second proximal end segment 32 disengage toward the distal end, thereby releasing the distal end portion of the stent 50. In other words, there is no particular restriction on the release order of the distal end and the proximal end of the main stent 50.

[0105] In order to facilitate the smooth release of the stent, the main stent delivery system of the present invention may also have a further member coaxially arranged with the inner catheter and the outer catheter. Figure 2 , which shows a perspective schematic diagram of another modified main stent delivery system 100. For clarity, the main stent portion shielded by the outer catheter is not shown.

[0106] The main stent delivery system 100 includes a main delivery catheter 120 and a main stent 150. The main delivery catheter 120 includes an outer catheter 130, an inner catheter 140 and a push rod 170 coaxially arranged along a longitudinal axis XX. The outer catheter 130 has a first hollow cavity 133. The inner catheter 140 is coaxially arranged with the outer catheter 130 along the longitudinal axis XX and has a second hollow cavity 143. The inner catheter 140 extends in the first hollow cavity 133 of the outer catheter 130 and further extends from a distal end port 135 of the outer catheter 130.

[0107] The main stent 150 is releasably retained in the first hollow cavity 133 between the outer catheter 130 and the inner catheter 140 in the delivery configuration.

[0108] In the delivery system 100 of this embodiment, the outer catheter 130 is also configured as two separable parts 131 and 132 at its proximal end. In this embodiment, the first proximal end section 131 of the outer catheter 130 is fixedly connected to the push rod 170 at its proximal end through the connector 160. Through the fixation of the connector 160, the first proximal end section 131 of the outer catheter and the push rod 170 can move as a whole. Figure 2 In the figure, the second proximal end section 132 of the outer catheter 130 is integrated with the distal end section of the outer catheter. By pulling the distal end 135 of the outer catheter, the second proximal end section 132 of the outer catheter can move relative to the inner catheter 140 and the push rod 170 and move away from the first proximal end section 131.

[0109] and Figure 1The main stent delivery system 10 shown in the figure operates in a similar manner, and the main stent delivery system 100 can also gradually release the stent 150 from the middle part to both ends. There is no particular restriction on the order of release. As can be seen from the stent method described in detail below, the order of release is determined according to the needs of the treatment site.

[0110] Those skilled in the art will appreciate that the outer catheter of the delivery system 10, 100 of the present invention can also recycle at least a portion of the released stent into the inner portion of the outer catheter as needed. For example, by moving the distal end 35, 135 of the outer catheter toward the proximal end, the released portion of the stent 50, 150 can be re-collected between the inner and outer catheters.

[0111] According to another specific example (not shown), the main stent delivery system of the present invention may further include a sleeve coaxially arranged outside the outer catheter. The sleeve is used to protect the delivery system to smoothly pass through the aorta to reach the lesion site, avoid kinking and prevent the stent from being released smoothly, etc. The present invention does not specifically limit the structure of the sleeve, and it can be set as needed.

[0112] above Figure 1 and Figure 2 The main stent delivery system shown exemplarily, in which the proximal end portion of the outer catheter, i.e., the portion where the stent is restricted, can set the length of the first proximal end segment and the second proximal end segment in any ratio. For example, the length ratio of the first proximal end segment and the second proximal end segment is (1:9) to (9:1). Preferably, the length ratio of the first and second proximal end segments of the outer catheter is, for example, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 or 2:8, preferably (4:6) to (6:4). The length ratio can be determined according to the treatment site, treatment plan and the release method of the main stent delivery system.

[0113] According to one embodiment, the first proximal end segment or the second proximal end segment may have a very short length. For example, the first proximal end segment may have a length as short as about 1 cm, such as 1 to 20 cm. Specifically, such as a length of about 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm, 16 cm, 17 cm or 18 cm. Correspondingly, the second proximal end segment has a length as long as about the length of the entire main stent in the delivery configuration, or a length of about 1 to 10 cm shorter than the length of the main stent in the delivery configuration. Specifically, such as a length of about 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm or 9 cm shorter than the length of the main stent in the delivery configuration. And vice versa. This embodiment is combined with the following Figure 3 and Figure 4The main stent delivery system described is relatively similar and can generally allow for gradual release starting from either the proximal or distal end of the main stent.

[0114] The outer dimensions of the main delivery catheter used in the present invention can be determined according to actual needs. For example, the main delivery catheter as a whole can have an outer diameter of about 5 to 10 mm (i.e., 15-30 Fr), preferably about 5 to 8 mm (i.e., 15-24 Fr). The outer diameter of the main delivery catheter can be as small as possible to facilitate the subsequent placement of the branch stent.

[0115] Figure 3 An example according to a second embodiment of the present invention is shown. According to this embodiment, the main stent is released starting from the distal end (ie, the end close to the operator).

[0116] See also Figure 3 , which shows the Figure 2 The main stent delivery system 100 shown is similar in structure to the main stent delivery system 200. The main stent delivery system 200 also includes a main delivery catheter 220 and a main stent 250. The main delivery catheter 220 includes an outer catheter 230, an inner catheter 240 and a push rod 270 coaxially arranged along the longitudinal axis XX. The outer catheter 230 has a first hollow cavity 233. The inner catheter 240 is coaxially arranged with the outer catheter 230 along the longitudinal axis XX and has a second hollow cavity 243. The main stent 250 is releasably retained in the first hollow cavity 233 between the outer catheter 230 and the inner catheter 240 in a delivery configuration.

[0117] In this embodiment, the outer catheter 230 includes a proximal end 234 and a distal end 236 for limiting the main stent 250, and the proximal end 234 and the distal end 236 can be separated from each other by operating the push rod 270. The proximal end 234 of the outer catheter 230 is fixedly connected to the push rod 270 at its proximal end through a connector 260. The proximal end 234 of the outer catheter and the push rod 270 can move as a whole through the fixation of the connector 260. The distal end 236 of the outer catheter 230 is fixedly connected to the inner catheter 240 at its distal end, so that the distal end 236 of the outer catheter and the inner catheter 240 can move as a whole.

[0118] In this example, if Figure 3 As shown, the distal end 236 of the outer catheter 230 can be kept stationary, and the proximal end 234 of the outer catheter is moved toward the proximal end by pushing the push rod 270, thereby moving away from the distal end 236 of the outer catheter. By pushing the push rod 270, the main stent 250 is gradually released from the distal end. Figure 3FIG. 2 shows a situation where the distal end of the main stent 250 has been partially released. The distal end 256 of the main stent 250 is still confined in the outer catheter 230 and is not completely released. According to the stent placement method described in detail below, the distal end 256 of the main stent will be released after the position of the main stent relative to the blood vessel is adjusted, so that the partially released portion of the main stent expands and adheres to the inner wall of the blood vessel.

[0119] Of course, the proximal end 234 of the outer catheter 230 can be kept stationary, and the proximal end 236 of the outer catheter 230 can be pulled to drive the inner catheter 240 and the main bracket 250 to move toward the distal end relative to the proximal end 234 of the outer catheter, thereby gradually releasing the main bracket 250 from the distal end.

[0120] Likewise, the main stent delivery system 200 of this embodiment may further include a sleeve; or in certain structures, the inner catheter 240 may be used as a pushing device, and the pushing rod 270 may be omitted.

[0121] Figure 4 An example according to a third embodiment of the present invention is shown. According to this embodiment, the main stent is released starting from the proximal end (ie the end away from the operator).

[0122] like Figure 4 As shown, the main stent delivery system 300 has a structure generally similar to the main stent delivery system 200, including a main delivery catheter 320 and a main stent 350. The main delivery catheter 320 includes an outer catheter 330, an inner catheter 340 and a push rod 370 coaxially arranged along the longitudinal axis XX. The outer catheter 330 has a first hollow cavity 233. The inner catheter 340 has a second hollow cavity 343. The main stent 350 is releasably retained in the first hollow cavity 333 between the outer catheter 330 and the inner catheter 340 in a delivery configuration.

[0123] This implementation method and Figures 2-3 Unlike the embodiment shown, the outer catheter 330 is formed as a whole. The proximal end 331 of the outer catheter can be separated from the proximal end 322 of the main delivery catheter 320. The proximal end of the inner catheter 340 is fixedly connected to the proximal end of the push rod 370 through the connector 360. Through the connector 360, the inner catheter 340 and the push rod 370 can move as a whole.

[0124] In this example, if Figure 4 As shown, the push rod 370 can be kept stationary, and by pulling the distal end 335 of the outer catheter 230, the outer catheter moves toward the distal end relative to the inner catheter 340 and the push rod 370, thereby gradually releasing the main stent starting from the proximal end 354 of the main stent 350. Figure 4FIG. 3 shows a situation where the proximal end of the main stent 350 has been partially released. The proximal end 354 of the main stent is temporarily still restricted on the surface of the inner catheter 330. After the position of the main stent 350 is adjusted, the proximal end 354 will be released, so that a part of the proximal end of the main stent is attached to the inner wall of the blood vessel.

[0125] Of course, the outer catheter 330 can be kept stationary, and the push rod 370 can be pushed toward the proximal end, driving the inner catheter 340 and the main support 350 restricted by the outer wall of the inner catheter to move toward the proximal end, so that the proximal end part of the main support 350 begins to be gradually released.

[0126] Likewise, the main stent delivery system 300 of this embodiment may further include a sleeve; or the inner catheter 340 may be used as a pushing device, and the pushing rod 370 may be omitted.

[0127] Several specific embodiments of the main stent delivery system of the present invention are shown above, but the embodiments of the present invention are not limited thereto. It should be known to those skilled in the art that more release forms of the main stent can be formed by configuring the structure and connection mode of the inner and outer push rods and / or sleeves. Any delivery system structure of the main stent gradual release form and the corresponding cover release form that is conducive to the positioning of the main stent and the placement of the branch stent is within the scope of protection of the present invention.

[0128] The main stent delivery system of the present invention is designed to place a bare stent with an opening in an aortic vessel. The main stent is compressed in the lumen of the outer catheter in the delivery configuration. The main stent can have an outer diameter of about 20-60 mm and a length of about 100-400 mm in the release configuration. Therefore, the main delivery catheter (such as the outer catheter) of the main stent delivery system of the present invention generally has an outer diameter of about 5 to 10 mm (i.e., 15 to 30 Fr) and a length of about 500 to 1000 mm (i.e., 150 to 300 Fr).

[0129] Main bracket

[0130] According to the stent placement method to be described in detail below, since the present invention uses a bare stent, even if a portion of the released stent expands and presses against the inner wall of the aorta, it will not hinder the flow of blood. Therefore, compared with the traditional aortic covered stent placement method, the safety and operability of the delivery system of the present invention during the entire placement process are greatly improved.

[0131] The main stents 50, 150, 250 and 350 used in the main stent delivery system of the present invention are bare stents. Unlike the conventional covered stents used in the aorta, the bare stents can generally maintain blood flow when partially released. Therefore, unlike the conventional covered aortic stent placement surgery, the stent of the present invention can be gradually released, and the branch vessel stents can be placed while being released, thereby solving the problem of difficult positioning in the process of the covered main stent that must be positioned first and then quickly released.

[0132] The main stent delivery system according to the present invention includes a main stent to be released at the treatment site. The main stent that can be used in the present invention is self-expandable or capsule-expandable. The present invention has no particular restrictions on the main stent, which can be any bare stent suitable for the treatment of the corresponding disease. The material of the stent can be metal, such as shape memory alloys (such as nitinol), cobalt-chromium alloys; medical polymers, such as nylon, polyester, polytetrafluoroethylene, polyacrylates, polyolefins, etc.; or it can be a bio-derived material or a biodegradable material.

[0133] The size of the main stent in the released configuration matches the size of the aorta at the treatment site. When the main stent is in the delivery configuration, it is constrained between the outer catheter and the inner catheter.

[0134] The size of the opening on the main stent generally matches the opening of the branch artery in the aorta when the main stent is in the released configuration, thereby allowing blood in the aorta to freely enter the branch artery when the main stent is partially or fully released.

[0135] The main stent according to the present invention may have at least one opening, such as 2, 3, 4 or even more openings. Preferably, the main stent of this embodiment is suitable for treatment of the aortic arch or the abdominal aorta. Figure 5 , which shows schematic diagrams of two main stents that can be used in the main stent delivery system of the present invention. Figure 5 A is a main stent 1a with three openings suitable for the aortic arch. The main stent 1a has a stent body 11a and three openings 12a roughly corresponding to the positions of the brachiocephalic trunk, left common carotid artery and left subclavian artery in the aortic arch. Figure 5 B shows a main stent 1b with four openings suitable for the abdominal aorta. The main stent 1b also has a stent body 11b. The stent body 11b has four openings 12b, which roughly correspond to the left renal artery, the right renal artery, the celiac trunk and the superior mesenteric artery.

[0136] Compared with the covered stent, the bare stent has greater elasticity and deformability, so it can be prepared into a standard opening piece with standard specifications, and the relative position of the opening can be slightly adjusted during placement by utilizing its deformability.

[0137] Another embodiment of the main support that can be used in the present invention is as follows Figure 6 As shown, a partial schematic diagram of an opening of the main support is shown, wherein a pipeline is provided near the opening. Figure 6 Various specific examples of the pipeline are shown. Figure 6 A shows a main stent 2a. The inner cavity of a part of the main stent body 21a of the main stent 2a is configured to form a main channel 23a, in which there is a pipe 25a. The pipe is surrounded by a separate component (which can be made of the same material as the main stent body) to form a sub-channel 26a leading to the opening 22a. The pipe 25a extends a distance from the opening 22a to the distal end of the main stent 2a. Figure 6 In the example shown in A, the tube 25a completely includes the opening 22a on its tube wall. According to one embodiment, the tube 35 may be a cylindrical component formed separately from the stent material and fixed (eg, braided with filaments of the stent material) to the inner wall of the main stent.

[0138] The arrangement of the conduit helps to position the branch stent when placing it, and guides the proximal end of the branch stent delivery system into the correct branch vessel. In addition, the arrangement of the conduit also helps to stably maintain the branch stent in the branch vessel after placement.

[0139] Since the main stent of the present invention is a standard part produced in an industrialized manner, the position of each opening may be slightly adjusted in individual surgery, or slightly deviate from the opening of the branch blood vessel in some cases. Therefore, the branch stent may be subjected to deformation tension from the main stent after release. The pipeline can help the branch stent to be stably maintained in an appropriate position by retaining a section of the branch stent body therein.

[0140] The maximum size of the pipe can match the size of the branch stent after it is released, so that at least a part of the stent body of the branch stent can be stably maintained therein.

[0141] . Figure 6 B shows a partial schematic diagram of the main stent 2b. The pipe 25b is arranged on one side of the opening 22b (i.e., the distal end side). In this structure, the pipe 25b is a cylindrical member and does not cover the opening 22b, but is arranged in the main channel 23b on the distal end side of the opening. When the branch stent is placed into the branch blood vessel from the distal end side of the main stent through the distal port 25b', the proximal port 25b" of the pipe and the opening 22b adjacent to the pipe 25b, a part of the distal end side of the branch stent remains in the pipe 35.

[0142] Figure 6 C shows the form of a pipe 25c covering the opening 22c of the main stent 2c and extending toward the proximal end and the distal end at the same time. The pipe 25c is suitable for a branch stent of a specific T-shaped shape and is more conducive to the stability of the branch stent.

[0143] Figure 6 D shows a conduit 25d formed by a portion of the main stent body 21d and another component 23d (which may be formed of the same stent material as the main stent). The conduit 25d partially covers the opening 22d, and its proximal port 25d' perpendicularly intersects the main stent body at the middle of the main stent opening 22d, and its distal port 25d" opens at the distal end of the main stent 2d.

[0144] Figure 7 A and B show two exemplary embodiments in which the internal conduit is completely formed by the stent body of the main stent.

[0145] Figure 7 In A, the main stent 3a has a main stent body 31a forming a main channel 33a and a pipe 35a protruding from the main channel 33a. The pipe 35a is surrounded by a part of the main stent body to form a sub-channel 36a that allows the branch stent delivery system to pass through and place the branch stent. Figure 7 As shown in FIG. 1A , the sub-channel 36a is formed outside the main channel 33a, and the distal port 35a′ and the proximal port 35a″ of the sub-channel are also respectively located outside the main channel 33a. The tangent portion between the sub-channel 36a and the main channel 33a can be mutually closed or interconnected.

[0146] Figure 7 B shows another example of forming an internal pipe by the support body of the main support 3b. In this example, the main support 3b has a main channel 33b formed by the main support body 31b and a pipe 35b partially protruding from the main channel 33b. The pipe 35b is also formed by a part of the main support body 31b through hot pressing. Figure 7 The main support 3a shown in A is different. Figure 7 The proximal port 35b' of the sub-channel 36b surrounded by the pipe 35b in B is located outside the main channel 33b; while the distal port 35b" and the distal port 31b" of the main channel open together in the distal end portion of the main support and re-merge into a common channel 33b" in the distal end portion of the main support.

[0147] exist Figure 7 In the examples shown in A and B, the tangent parts between the sub-channels 36a, 36b and the main channels 33a, 33b can be closed or interconnected. The sub-channel part can usually be formed by hot pressing. In this way, before the main stent is hot pressed, the part to be formed into the sub-channel can have a larger diameter than other parts, so that the main channel and the sub-channel are formed by using the stent body with a larger diameter.

[0148] Depend on Figure 7It can be seen that the main support of this embodiment can have a variety of specific ways of arranging the pipeline, but the main support applicable to the present invention is not limited to these exemplary ways. The pipeline can also have different shapes, lengths and inner diameters. These structures can be determined by those skilled in the art based on the disclosure of the present invention and according to actual needs.

[0149] Figure 8 A schematic diagram of a bifurcated main stent for the abdominal aorta that can be used in the present invention is shown. Figure 8 As shown, the abdominal aorta stent 4 has a main stent body 41, and the inner cavity of the main stent body 41 forms a main channel 47. The left and right renal artery openings 42a, 42b, the superior mesenteric artery opening 42c and the celiac trunk artery opening 42d are arranged on the side walls of the main stent body 41 respectively. Two sub-channels 44a and 44b are formed in the main channel. The sub-channels are arranged at the distal end of the main stent, and have proximal openings 44a' and 44b', and distal openings 44a" and 44b". Figure 8 In the illustrated structure, the sub-channels 44a and 44b extend completely outside the main channel 47. According to another example, the main channel formed by the main support body 41 can partially or completely accommodate the sub-channels 44a and 44b.

[0150] Regardless of the above configuration, the subchannels 44a and 44b may have the same length (eg, Figure 8 as shown), or have different lengths.

[0151] Figure 8 The abdominal aorta main stent with bifurcation shown is advantageous for further placement of stents of the left and right common iliac arteries under the positioning of the sub-channels after being released in the abdominal aorta.

[0152] Figure 8 The inner cavity of the abdominal aorta main stent shown in the figure may also have the above Figure 6 and 7 The pipe shown in , to facilitate the placement and stability of the branch support. At least one opening or several or all of the openings may have a pipe. Because the openings 42c and 42d are very close, a pipe may also be used together.

[0153] Fig. 9 The main stents for the aortic arch and the abdominal aorta of the present invention are shown respectively. Fig. 9A1 and A2 show two examples of main stents 5 and 5' suitable for the aortic arch. As shown in Figure A1, the main stent 5 has a main stent body 51 and a main channel 53 surrounded by the main stent body 51. The openings 55a, 55b and 55c corresponding to the brachiocephalic trunk, the left common carotid artery and the left subclavian artery on the aortic arch are arranged roughly along the longitudinal axis of the main stent 5. A part of the main stent body 51 is formed into sub-channels 56a, 56b and 56c leading to the openings 55a, 55b and 55c respectively through a molding process. As shown in the figure, in order to facilitate the formation of each sub-channel, the sub-channels 56a and 56b are curved. The openings 53a, 53b and 53c at the other end of these sub-channels are in the main channel 53. Figure A1 shows that the openings 53a, 53b and 53c are arranged on the same horizontal plane perpendicular to the longitudinal axis of the main stent. As needed, the openings 53a, 53b and 53c can be on different horizontal planes perpendicular to the longitudinal axis of the main stent (not shown). The opening arrangement of the main stent is more consistent with the opening of the branch artery at the aortic arch, so that each stent fits better with the blood vessel wall after placement.

[0154] The main stent 5' shown in Figure A2 has the same main stent body 51 as the main stent 5 shown in Figure A1 and a main channel 53 surrounded by the main stent body 51. Among them, the openings 55a', 55b' and 55c' corresponding to the brachiocephalic trunk, the left common carotid artery and the left subclavian artery on the aortic arch are generally arranged on the same horizontal plane perpendicular to the longitudinal axis of the main stent 5', so that the sub-channels 56a', 56b' and 56c' respectively formed by a part of the main stent body 51 are generally arranged in parallel along the longitudinal axis of the main stent 5'. The openings 53a, 53b and 53c at the other end of these sub-channels are also arranged in the same plane perpendicular to the longitudinal axis of the main stent in the main channel 53. The opening arrangement of the main stent makes the longitudinal axes of the sub-channels generally parallel to the longitudinal axis of the main channel, and the opening direction is also generally consistent with the opening direction of the main channel, which is convenient for placing each branch stent. Since the main stent is a bare stent and has a certain deformation ability, the opening arrangement of the main stent will not cause the branch artery to be blocked.

[0155] Fig. 9 B1 and B2 show two examples of main stents 6 , 6 ′ suitable for use in the abdominal aorta.

[0156] As shown in FIG. B1, the main stent 6 has a main stent body 61 and a main channel 63 surrounded by the main stent body 61. The openings 65a, 65b, 65c and 65d corresponding to the main branch arteries (left renal artery, right renal artery, celiac trunk and superior mesenteric artery) on the abdominal aorta are arranged roughly according to the positions corresponding to the branch arteries. Among them, the openings 65c and 65d corresponding to the celiac trunk and the superior mesenteric artery are arranged longitudinally roughly parallel to the longitudinal axis of the main channel. A part of the main stent body 61 is formed into sub-channels 66a and 66b leading to the openings 65a and 65b, and a sub-channel 66c leading to the openings 65c and 65d through a shaping process. In other words, the openings 65c and 65d share the sub-channel 66c. As shown in the figure, the diameter of the main stent part where the openings 65a and 65b and sub-channels 66a and 66b are located is slightly larger than the other parts, and the plane where the openings 65a and 65b are located is located on the inclined surface where the diameter of the main stent body gradually increases, thereby forming angles α and β with the longitudinal axis of the main stent. Angles α and β can be the same or different, and the angle can be 1° to 10°. The openings 63a and 63b at the other ends of the sub-channels 66a and 66b are in the main channel 63. The two ends of the sub-channel 66c have openings 63c and 63d in the main channel 63 respectively. The openings 65c and 65d leading to the branch blood vessels are located on the outer wall of the sub-channel 66c. The diameter of the sub-channel 66c is greater than or equal to the sum of the diameters of the branch blood vessel openings 65c and 65d so as to accommodate two branch stents. Figure 8 Similar to the main stent shown in FIG. 1 , the distal end of the main stent 6 also has sub-channels 64a and 64b for subsequently placing the left and right common iliac artery stents. The opening arrangement of the main stent 6 is more consistent with the opening of the branch artery at the aortic arch. After placement, each stent fits better with the blood vessel wall.

[0157] The main stent 6' shown in FIG. B2 has a structure that is substantially the same as the main stent 6 of FIG. B1, except that the openings 65c' and 65d' corresponding to the celiac trunk and the superior mesenteric artery are arranged side by side in the same plane substantially perpendicular to the longitudinal axis of the main channel, and sub-channels 66c' and 66d' are formed by the main stent body corresponding to the openings 65c' and 65d'. The sub-channels 66c' and 66d' are substantially parallel to the longitudinal axis of the main channel. One end of the sub-channels 66c' and 66d' leads to the openings 65c' and 65d', respectively, and the other end has openings 63c' and 63d' in the main channel, respectively. The opening arrangement of the main stent makes the longitudinal axes of the sub-channels 66c' and 66d' substantially parallel to the longitudinal axis of the main channel, and the opening direction is also substantially consistent with the opening direction of the main channel, which is convenient for placing the branch stents of the celiac trunk and the superior mesenteric artery. Since the main stent is a bare stent and has a certain degree of deformation ability, the opening arrangement of the main stent will not cause the branch artery to be blocked.

[0158] The main stent of the present invention has an outer diameter that is compatible with the inner diameter of the aorta in the released state, usually in the range of 20 to 60 mm. The length of the main stent can be determined specifically according to the treatment site. For example, the length of the main stent used in the aortic arch can be 10-400 mm, and the length of the main stent used in the abdominal aorta can be 10-400 mm. The specific size of the main stent can be determined according to actual needs.

[0159] The main stent that can be used in the present invention is not limited to the specific examples listed above. Any suitable bare stent can be used in the present invention.

[0160] Stent placement method

[0161] Furthermore, the present invention also provides a method for placing a stent at a treatment site of the aorta, particularly at a site with branched blood vessels, using the main stent delivery system.

[0162] In general, the aortic stent placement method of the present invention utilizes the characteristic of bare stents that they do not block blood flow, and by gradually partially releasing the main stent and positioning and placing branch stents one by one as the main stent is released, the difficulty of aortic stent surgery is reduced, the surgical process is accelerated, and the surgical risk is reduced. In addition, the method allows the use of standard main stent parts, avoiding the problems caused by customized openings or openings during surgery.

[0163] The stent placement method of the present invention is further described below with reference to the accompanying drawings and specific examples.

[0164] like Fig.10 As shown, it schematically shows the Figure 1 The procedure for stent placement using the Master Stent Delivery System is shown.

[0165] See also Fig.10 A, Figure 1 The main stent delivery system 10 shown has been guided into the aortic vessel 90 at the treatment site by a guide wire (not shown). A branch vessel 91 in the aortic vessel is schematically shown in the figure. As described above, by operating the pusher 70 of the main stent delivery system 10, the outer catheter 30 is pulled toward the distal end, so that the second proximal end segment 32 thereof is away from the first proximal end segment 31 and moves toward the distal end, so that the main stent 50 is released from the middle thereof toward the distal end thereof. Fig. 9 The figure shows the situation that the distal end 55 of the main stent 50 has been released.

[0166] Before completely releasing the distal end 55 of the main stent, the main stent 50 can be partially released to expose the first opening 52 on the wall of the main stent near the opening 92 of the first branch vessel 91 in the aortic vessel. When necessary, the first proximal end section 31 of the outer catheter 30 can be further pushed toward the proximal end to expose the first opening 52 from the outer catheter. The position of the main stent delivery system 10 and the degree of release of the main stent 50 are controlled and adjusted so that the first opening 52 is located near the opening 92 of the first branch vessel. The position of the first proximal end section 31 of the outer catheter is further adjusted so that the main stent 50 at the opening 52 is in a semi-released state. That is, the opening 52 has a certain distance d from the wall of the aortic vessel 90. For example, the distance between the opening 52 and the vessel wall is 5 to 20 mm, preferably at least about 8 mm, and more preferably at least about 10 mm.

[0167] After adjusting the position of the opening 52, the distal end 55 of the main stent is released, so that the distal end is in a fully released configuration and abuts against the vessel wall. A guide wire 61 is introduced into the treatment site, and the guide wire 61 passes from the distal end 55 of the main stent 50 into the released cavity 53 of the main stent, and further passes out from the first opening 52 and enters the first branch vessel 91.

[0168] After confirming the position of the guide wire 61 again, the first delivery catheter 60 of the first branch stent delivery system is guided by the guide wire 61 to enter the appropriate position of the first branch blood vessel 91 ( Fig.10 B).

[0169] After confirming the delivery position of the branch stent again, release the branch stent 65 ( Fig.10 C).

[0170] If you use something like Figure 6 As shown in the main stent having a tube in the inner cavity of the main stent, the distal end portion of the branch stent 65 can be retained in the tube to stabilize the branch stent 65.

[0171] The second opening 53 on the main bracket 50 is further released by the above method. Fig.10 As shown in FIG. D, the same steps are performed, and the second delivery catheter 70 of the second branch stent delivery system is guided by the guide wire 71 to enter the inner cavity of the main stent 50 and extend from the second opening 53 into the second branch vessel 93 to place the second branch stent (not shown). The main stent is completely released after all the branch stents to be placed are placed.

[0172] The above-mentioned method of delivering the main stent of the present invention can release the main stent while positioning the opening on the main stent, and after the opening is roughly positioned, the branch stent can be placed immediately. Since the main stent of the present invention is a bare stent, even if the main stent is partially released, it will not cause complete blockage of the blood flow, thereby reducing the risk during the operation. This method is more conducive to the positioning of the opening and the branch stent by making the opening on the main stent in a semi-released state. However, this method cannot be used for traditional coated stents. Once the coated stent is partially released, it will completely block the blood flow, so that the operation cannot be performed at all. Traditional aortic stents are all coated stents. During placement, the delivery catheter needs to be adjusted to accurately position the whole (i.e., all openings) and then quickly release the stent completely. The difficulty in positioning this method is the main reason for the long operation time and high risk.

[0173] In addition, the poor deformability and fluid-impermeability of the coated stent require that the multiple openings on it must be precisely positioned. Otherwise, if the openings of the branch vessels cannot be accurately aligned, the branch blood flow will be insufficient or even completely blocked. Moreover, if the main stent opening cannot be accurately aligned with the branch vessel opening, it will also make it impossible to place further branch stents. The main stent of the present invention is a bare stent, which has good deformability. Even if the opening position is deviated, the branch stents can be placed one by one without blocking the branch blood flow.

[0174] Fig.10 The figure shows the method of placing the main stent and the branch stent from one direction. Most surgeries are performed in this way. That is, each delivery system is introduced from the femoral artery. According to the actual situation, the main stent and the branch stent can also be placed from different directions. For example, for the aortic arch, the main stent delivery system can be introduced from the femoral artery, and the branch stent delivery system can be introduced from the superior artery of the neck arch or the brachial artery.

[0175] The main stent delivery systems of various embodiments shown above can all be used in the method of the present invention. Those skilled in the art can select a suitable main stent delivery system, as well as the release direction and release form of the main stent according to actual needs.

[0176] The branch stent delivery system and branch stent applicable to the present invention are not particularly limited. Any conventional suitable stent delivery system and stent can be used for the branch stent delivery system. The above method of introducing the guide wire is used as an example of the placement of the branch stent.

[0177] Preferably, an adjustable bend catheter can also be used as a branch stent delivery system. The adjustable bend catheter usually has an adjustable bend sheath, a traction wire and an adjustable bend driver. The proximal end of the adjustable bend sheath can be bent in any direction and at any angle by manipulating the adjustable bend driver and the traction wire connected thereto, so that it can be quickly and flexibly positioned in the branch vessel. The branch stent delivery system using the adjustable bend catheter eliminates the step of guidewire positioning, further shortening the operation time.

[0178] The present invention has no particular limitation on the adjustable bend conduit, and any suitable adjustable bend conduit can be used in the present invention.

[0179] Fig.11 The schematic diagram of placing a stent at the aortic arch using the above method is schematically shown.

[0180] like Fig.11 As shown in A, the aortic arch 800 has three main branch arteries. On the convex side of the aortic arch, from the proximal end, there are three major branches: the brachiocephalic trunk (innominate artery) 830, the left common carotid artery 820, and the left subclavian artery 810. They are the main arterial trunks that supply blood to the head, neck, and upper limbs. Figure 1 The main stent delivery system 10 shown has a similar structure, and has an outer catheter 530, an inner catheter 540 and a main stent 550. The outer catheter 530 has a first proximal end section 531 and a second proximal end section 532.

[0181] As shown in A in the figure, the second proximal end section 532 of the outer catheter has been pulled toward the distal end, and then the first proximal end section 531 of the outer catheter has been pushed toward the proximal end, so that most of the main stent is released from the distal end portion of the main stent 550. The main stent 550 has openings 552a, 552b and 552c in sequence from the distal end corresponding to the position of the branch artery. Each opening has a pipeline 555a, 555b and 555c inside.

[0182] The first branch stent 581 has been placed in the left subclavian artery 810 according to the aforementioned method. The distal end portion of the first branch stent 581 remains in the first pipe 555a, so that the branch stent 581 is stably maintained in the branch artery 810. Similarly, the second branch stent 582 has also been placed in the left common carotid artery 820. Its distal end portion remains in the second pipe 555b.

[0183] The third branch stent (not shown) is being delivered by the third branch stent delivery system 570c under the guidance of the guide wire 571 through the lumen of the distal end portion of the main stent that has been released, and further through the third tube 555c and the third opening 552c, extending into the brachiocephalic trunk 830.

[0184] According to the same method as above, the position of the third branch stent delivery system 570c is adjusted, and the third branch stent is placed in the brachiocephalic trunk 830, and the third branch stent delivery system 570c is withdrawn. Then, the proximal end of the main stent is also completely released by pushing the first proximal end section 531 of the outer catheter forward. Finally, the main stent delivery catheter is withdrawn from the inner cavity of the completely released main stent 550 (see Fig.11 B). This completes the placement of all stents in the aortic arch.

[0185] Fig.12 Another method for placing a stent in a main stent delivery system is schematically shown. The method shows a method for placing two branch stents simultaneously in two adjacent openings on the main stent.

[0186] Take the abdominal aorta as an example. The abdominal aorta 900 has left and right renal arteries 910 and 920 of substantially the same height. The main stent delivery system 600 also has a main delivery catheter and a main stent 650. The main delivery catheter has an inner catheter 640 and an outer catheter 630. Figure 1 The structure of the delivery system shown is similar, and the outer catheter 630 of the main stent delivery system 600 has a first proximal end segment 631 and a second proximal end segment 632 that can be movably separated. The main stent 650 has four openings suitable for the branch vessels of the abdominal aorta. Fig.10 Openings 652a and 652b corresponding to the left and right renal arteries 910 and 920 are shown.

[0187] According to the method of the present invention, firstly, the first opening 652a and the second opening 652b on the wall of the main stent 650 are exposed. Since the left and right renal arteries are substantially at the same level, the first and second openings are exposed simultaneously. The position of the main stent delivery system 600 and the degree of release of the main stent 650 are controlled and adjusted so that the first opening 652a is located near the opening of the left renal artery 910, and the second opening 652b is located near the opening of the right renal artery 920.

[0188] After adjusting the positions of the openings 652a and 652b, the distal end of the main stent 650 is released so that the distal end is in a fully released configuration and abuts against the vessel wall. Guide wires 671 and 672 are simultaneously introduced into the treatment site and positioned in the left renal artery 910 and the right renal artery 920, respectively.

[0189] After confirming the positions of the guidewires 671 and 672 again, the first delivery catheter 670a and the second delivery catheter 670b of the first and second branch stent delivery systems are guided by the guidewires to enter the appropriate positions in the left renal artery 910 and the right renal artery 920, respectively. Fig.10 ). After reconfirming the delivery position of the branch stent, release the branch stent.

[0190] This method allows the placement of two branch stents at the same time if space permits, thereby further speeding up the operation and shortening the operation time.

[0191] The above descriptions are only some specific implementation methods of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A main stent delivery system, comprising: A primary delivery catheter and a primary stent, wherein The main delivery catheter comprises an outer catheter and an inner catheter arranged coaxially, wherein the outer catheter has a proximal end and a distal end and has a first hollow lumen, the inner catheter extending within the first hollow lumen of the outer catheter; and The main stent is releasably retained in a delivery configuration in a first hollow cavity between the outer catheter and the inner catheter at the proximal end of the main delivery catheter, The main stent is characterized in that the main stent is a bare stent, so that the main stent can be gradually released, and the main stent comprises a main stent body and a main channel surrounded by the main stent body, wherein at least one opening is arranged on the main stent body; When the main stent is in the released configuration, the opening is configured to have a relative position and size on the main stent that is substantially consistent with the position and size of the opening of the branch vessel on the main vessel of the treatment site on the main vessel; The main channel of the main stent has a pipe therein, the pipe is surrounded by separate components to form a sub-channel leading to the opening, the sub-channel is used to guide and hold the branch stent to be placed in the branch vessel, wherein the pipe completely includes the opening on its pipe wall.

2. The main stent delivery system according to claim 1, wherein: The at least one opening is 2 to 6 openings.

3. The main stent delivery system according to claim 2, wherein: The at least one opening is 3 or 4 openings.

4. The main stent delivery system according to claim 1, wherein: The main vessel of the treatment site is the aortic arch or the abdominal aorta, wherein the branch vessels on the aortic arch are the brachiocephalic trunk, the left common carotid artery and the left subclavian artery, and the branch vessels on the abdominal aorta are the left renal artery, the right renal artery, the celiac trunk and the superior mesenteric artery.

5. The main stent delivery system according to any one of claims 1 to 4, wherein: The distal end of the outer catheter is composed of a first proximal end segment and a second proximal end segment, and the first proximal end segment and the second proximal end segment are configured to be relatively distant from each other along the longitudinal axis of the main delivery catheter, thereby allowing the main stent releasably maintained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be released sequentially from the middle to both ends.

6. The main stent delivery system according to claim 5, wherein: The length ratio of the first proximal end segment to the second proximal end segment is (1:9) to (9:1).

7. The main stent delivery system according to claim 6, wherein: The length ratio of the first proximal end segment to the second proximal end segment is (3:7) to (7:3).

8. The main stent delivery system according to claim 7, wherein: The length ratio of the first proximal end segment to the second proximal end segment is (4:6) to (6:4).

9. The main stent delivery system according to claim 5, wherein: The length of the first proximal end segment is 1 to 20 cm, or the length of the second proximal end segment is 1 to 10 cm.

10. The main stent delivery system according to claim 5, wherein: The first proximal end section of the outer catheter is fixedly connected to or integrally formed with the inner catheter at the proximal end.

11. The main stent delivery system according to claim 5, wherein: The inner catheter has a second hollow cavity, and the main delivery catheter also includes a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod is fixedly connected to the first proximal end section of the outer catheter at the proximal end or formed integrally therewith.

12. The main stent delivery system according to any one of claims 1 to 4, wherein: The proximal and distal ends of the outer catheter can be relatively distant from each other along the longitudinal axis of the main delivery catheter, thereby allowing the main stent releasably retained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be gradually released from the distal end to the proximal end.

13. The main stent delivery system according to claim 12, wherein: The proximal end of the outer catheter is fixedly connected to or integrally formed with the inner catheter at the proximal end.

14. The main stent delivery system according to claim 12, wherein: The inner catheter has a second hollow cavity, and the main delivery catheter also includes a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod is fixedly connected to the outer catheter at the proximal end or formed integrally.

15. The main stent delivery system according to any one of claims 1 to 4, wherein: The outer catheter can be moved relative to the inner catheter along the longitudinal axis of the main delivery catheter toward the distal end, thereby allowing the main stent releasably retained in the first hollow cavity between the outer catheter and the inner catheter in a delivery configuration to be gradually released from the proximal end to the distal end.

16. The main stent delivery system according to claim 15, wherein: The inner catheter has a second hollow cavity, and the main delivery catheter also includes a push rod coaxially arranged with the inner catheter and the outer catheter and extending in the second hollow cavity of the inner catheter, and the push rod is fixedly connected to the inner catheter at the proximal end or formed integrally.

17. The main stent delivery system according to any one of claims 1 to 4, wherein: The main delivery catheter has an outer diameter of 5-10 mm.

18. The main stent delivery system according to claim 17, wherein: The main delivery catheter has an outer diameter of 5-8 mm.

19. The main stent delivery system according to any one of claims 1 to 4, wherein: The outer wall of the proximal end of the inner catheter is provided with a component for preventing the main support from moving.

20. The main stent delivery system according to claim 19, wherein: The component for preventing the main support from moving is protrusions arranged at both ends of the proximal end of the inner catheter.

21. The main stent delivery system according to any one of claims 1 to 4, wherein: The main stent delivery system also has a main stent release limiting member arranged at the proximal end and the distal end of the main stent, and the main stent release limiting member is configured to keep the proximal end and / or the distal end of the main stent in a delivery configuration before the proximal end and / or the distal end of the main stent are completely released.

22. A multi-stent delivery system kit for a vessel with branches, characterized in that: The kit includes: The main stent delivery system according to claims 1 to 21; and At least one branched stent delivery system.

23. The multi-stent delivery system kit of claim 22, wherein: The branch stent delivery system includes an adjustable bend catheter and a branch stent releasably retained in the adjustable bend catheter in a delivery configuration.

24. The multi-stent delivery system kit according to claim 22 or 23, wherein: The branch stent is a bare stent or a covered stent.

25. A bare stent, applied to the main stent delivery system according to any one of claims 1 to 21, the bare stent comprising a stent body and a main channel surrounded by the stent body, wherein the stent body is provided with at least one opening, and when the bare stent is in a released configuration, the opening is configured to have a relative position and size on the bare stent that is substantially consistent with the position and size of an opening of a branch vessel on a main vessel at a treatment site on the main vessel; The main channel of the bare stent has a pipeline, which is surrounded by separate components to form a sub-channel leading to the opening, and the sub-channel is used to guide and hold the branch stent to be placed in the branch vessel, wherein: The pipe completely includes the opening in its pipe wall.

26. The bare stent according to claim 25, wherein: The at least one opening is 2 to 6 openings.

27. The bare stent according to claim 26, wherein: The at least one opening is 3 or 4 openings.

28. The bare stent according to claim 25, wherein: The main vessel of the treatment site is the aortic arch or the abdominal aorta, wherein the branch vessels on the aortic arch are the brachiocephalic trunk, the left common carotid artery and the left subclavian artery, and the branch vessels on the abdominal aorta are the left renal artery, the right renal artery, the celiac trunk and the superior mesenteric artery.

29. The bare stent according to claim 25, wherein: The sub-channel has a first opening and a second opening at both ends, respectively, wherein the first opening is the corresponding opening on the bare stent, and the second opening is arranged in the main channel of the bare stent or outside the main channel of the bare stent.

30. The bare stent according to claim 25, wherein: The stent body of the bare stent and the pipeline are respectively composed of braided metal wires or medical polymer wires, and the materials constituting the stent body of the bare stent and the pipeline are the same or different.

31. The bare stent according to claim 25, wherein: The bare stent is self-expandable or balloon-expandable.

32. The bare stent according to claim 25, wherein: The bare stent has a length of 10-400 mm and an outer diameter of 20-60 mm.

33. The bare stent according to claim 25 is used in the aortic arch or abdominal aorta and is a standard stent.

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