Delivery system for bifurcation support

Abstract

This invention describes a delivery system (100) for a bifurcated stent (200) having a rod (226) and a pair of arms (220, 222). The delivery system includes a delivery conduit (110) comprising an elongated first tube (102) having a proximal end (20) and a distal end (30) and a bifurcation portion (114) at the distal end (30), the bifurcation portion being configured to receive the arms (220, 222), wherein a longitudinal slit (140) disposed on the bifurcation portion (114) is configured to allow releasable passage of the bifurcated stent (200) through the longitudinal slit. The invention also describes a method for delivering the bifurcated stent to a treatment site using the delivery system (100).

Description

[0001] This application is a divisional application of the applicant’s patent application No. 201880014820.2 (PCT / EP2018 / 050554) entitled “Delivery System for Bifurcation Bracket”, filed on January 10, 2018. Technical Field

[0002] This article describes a delivery system for bifurcation stents and a method for treating arteries located at bifurcation points (e.g., aneurysms or occlusions). The system and method can be implemented for use with bifurcation aneurysms or occlusions located intracranially or extracranially (i.e., aortic or peripheral aneurysms). Background Technology

[0003] Intracranial aneurysms are saccular dilatations of cerebral arteries, or more rarely fusiform dilatations, caused by histological changes in the arterial wall. They result in thin walls that, if left untreated, pose a risk of rupture and thus intracranial hemorrhage (subarachnoid hemorrhage and / or intraparenchymal hemorrhage). In younger populations, intracranial aneurysm disease represents the most prevalent predisposition to fatal risk, with an estimated incidence of 5–7 cases per 100,000 people per year and a prevalence between 2% and 5%. It is a leading cause of hemorrhagic stroke and contributes to reduced life expectancy and potentially severe disability that impacts quality of life. The 30-day mortality rate associated with subarachnoid hemorrhage, second only to ruptured intracranial aneurysms, is estimated at 45%–50%. The associated morbidity is estimated at 25%–30%, and is dependent in nearly 30% of patients within one year, even with appropriate and early treatment. The risk of rupture of unruptured intracranial aneurysms is difficult to estimate and varies between 0.4% and 17.8% over five years. Intracranial aneurysms are increased by factors including age, sex, hypertension, smoking, aneurysm size, and location in the posterior circulation. Finally, aneurysm rupture and its complications have a significant economic impact in terms of the costs associated with the management of the acute phase, neurological deficits, and / or subsequent dependence. In Europe alone, between 35 and 37 million people may have intracranial aneurysms. In France alone, there are 6,000 intracranial hemorrhages annually, second only to ruptured intracranial aneurysms.

[0004] Regardless of the method chosen, the primary goal of intracranial aneurysm management is to remove the out-pouching malformation from the bloodstream. Most current practices for managing intracranial aneurysms are based on endovascular catheter-based methods, primarily represented by aneurysm filling with packing material (the so-called "coiling" technique using platinum coils and / or cellulose acetate polymers). The deployment of the packing material within the aneurysm can be associated with the inflation of a balloon within the arterial lumen during packing material deployment (called the "balloon remodeling method") or with the deployment of a stent within the artery covering the neck of the aneurysm (called the "stent-assisted coiling method") to prevent its protrusion within the artery. This results in thrombosis on the medial side of the aneurysm and its removal from the bloodstream. These techniques have quickly become the gold standard for intracranial management. Historically, surgical clipping was a method involving the placement of an aneurysm clip across the aneurysm to prevent blood flow into it. This technique is more invasive and is performed less frequently due to its high risk, especially in older or medically complex patients.

[0005] The methods described above involve permanently leaving a device in the body for aneurysm treatment or involve its temporary deployment in the lumen of an arterial bifurcation and its subsequent retrieval for treatment or arterial occlusion. For the first purpose, recent inventions of biodegradable polymers address this issue, and the device will be able to be removed from the body by time or by dissolving the biopolymer itself using a chemical composition. For the final purpose, a stent can be placed in cases of arterial stenosis and left permanently in the body, and therefore, apart from its design (laser-cut rather than a woven mesh), it exhibits the same material properties described above.

[0006] Despite significant advancements and paradigm shifts in the management of intracranial aneurysms through endovascular techniques, bifurcation aneurysms, especially those presenting with large necks or necks encircling one or both of the bifurcation branches, remain challenging to manage. Stent placement techniques represent an alternative approach for these aneurysms. Currently, many strategies are used to treat intracranial bifurcation aneurysms with currently available stent designs (laser-incision or braided stents), including stent-assisted coiling, Y-shaped stents, T-shaped stents, or compression stent techniques. For stenting, a common approach is to place a stent (laser-incision or braided stent) in the aorta and one of its branches (more commonly the largest branch or the branch more affected by the aneurysm) before or after coiling the aneurysm sac (occlusion method). If the first deployed stent is not sufficiently effective in preventing the coiled protrusion from entering the arterial lumen, a second stent is deployed within the first stent and the second branch (known as the Y-shaped stent technique). This latter technique may be used as a first option depending on arterial anatomy and access difficulties. However, with these methods, the amount of material within the arterial lumen and precisely across the arterial branches (multiple) is a source of increased thromboembolic complications in Y-shaped, T-shaped, and squeeze-stent techniques. Recently, flow diversion techniques based on the deployment of flow diverter stents within the aneurysm-bearing artery and flow interruption techniques based on the deployment of intravascular flow interruption devices within the aneurysm have also become options for those challenging aneurysms. Due to the higher material content in their design, flow diverter stents carry a higher risk of thromboembolic complications. Furthermore, in arterial bifurcation, the intravascular deployment of flow diverter stents not only covers the lateral perforator but also the bifurcation branch, which can compromise its patency in the long term. The flow interruption device method consists of a frame based on the same braided mesh as braided stents, which is deployed into the aneurysm sac to fill it, subsequently stopping flow within the sac and promoting intravascular thrombosis. This method is limited by incomplete occlusion of the aneurysm at its neck or bulging of the frame into the arterial lumen, which necessitates secondary rescue stent placement. These limitations stem from the frame's design; in most cases, despite its compliance, the frame fails to provide an ideal fit for the aneurysm neck and wall. 。

[0007] The objective of this invention is to overcome the problems encountered in the prior art. Another objective is to provide a new treatment for certain types of intracranial aneurysms located at the bifurcation of arteries, for which current treatments are widely considered inappropriate. Summary of the Invention

[0008] This document describes a delivery system (100) for a bifurcated support (200) having a rod (226) and a pair of arms (220, 222). The delivery system includes a delivery conduit (110) comprising an elongated first tube (102) having a proximal end (20) and a distal end (30) and a bifurcation portion (114) at the distal end (30) configured to receive the arms (220, 222), wherein a longitudinal slit (140) disposed on the bifurcation portion (114) is configured for releasable passage of the bifurcated support (200) through the longitudinal slit.

[0009] The longitudinal slot may extend from the first pin (120) of the bifurcation portion (114) to the second pin (122).

[0010] The bifurcation portion (114) of the first tube (102) may include first (120) and second (122) pins respectively configured for passing through branches (422, 424) of the bifurcation of the body's blood vessels.

[0011] The first (120) and second (122) pins may each be configured to radially compress the bifurcation bracket (200).

[0012] The delivery system (100) may further include an access conduit (300) comprising an elongated second tube (302) having a proximal end (20) and a distal end (30), the elongated second tube having a second lumen (330) adapted to slidably receive the first tube (102) and configured to control the gradual opening or folding of the bifurcation portion (114) of the first tube (102) in response to slidable relative displacement of the first (102) and the second (302) tubes.

[0013] The delivery catheter (110) can be configured for use in guidewire-based or rapid-exchange operation modes.

[0014] The delivery system (100) may further include the self-expanding bifurcation stent (200). The bifurcation stent (200) may contain an elutable active pharmaceutical ingredient and may optionally have antithrombotic, anticoagulant, endothelializing, cell migration stimulant, or cell growth stimulant properties. The bifurcation stent (200) may be prepared by laser cutting or weaving.

[0015] The delivery system (100) may further include a thruster (500) comprising an elongated flexible rod (510) having proximal (20) and distal (30) ends, and a capture element (520) at the distal (30) end for releasably attaching to the bifurcation support (200) at the proximal end (20), the capture element (520) being radially self-expanding to employ an open or folded configuration, wherein the folded configuration is configured for passage within the first lumen (230) of the first tube (102), and wherein the peripheral edges of the capture element (520) are brought closer together to grip the proximal end (20) of the bifurcation support (200), and wherein the open configuration is configured for releasing the bifurcation support (200).

[0016] The delivery system (100) may further include a loader (600) for loading the bifurcated support (200) into the delivery conduit (110), the loader including an elongated third tube (602) having a proximal end (20) and a distal end (30), the elongated third tube being provided with a third lumen (630) adapted to slidably receive the bifurcated support (200) in the folded configuration, wherein the distal end (30) of the third tube (602) is configured to engage with the proximal terminal end of the delivery conduit (110) such that the first (130) and the third (630) lumens are connected to form a continuous passage for the bifurcated support (200) in the folded state to advance from the loader (600) into the delivery conduit (110).

[0017] The kit described herein includes a delivery catheter (110) as defined herein, and one or more of the following:

[0018] -As defined in this document, the access catheter (300),

[0019] -As defined in this article, the bifurcated bracket (200),

[0020] - As defined in this article, the thruster (500),

[0021] - As defined in this article, the loader (600) and

[0022] - One or more guidewires.

[0023] This document describes a method for delivering a bifurcation support to a treatment site using a delivery system (100) as defined herein, the method comprising the following steps:

[0024] -The delivery catheter (110), which carries the bifurcated stent (200), is advanced within the blood vessel to the treatment site via the access catheter (300).

[0025] -The delivery catheter (110) is gradually opened by retraction of the access catheter (300), and

[0026] - The bifurcated support (200) is deployed by retracting the delivery conduit (110) through the slit (140).

[0027] Treatment can be for arterial aneurysms or arterial occlusion. Attached Figure Description

[0028] Figure 1 A schematic diagram of the delivery catheter as described herein is shown. Panels A, B, and B' show transverse cross-sectional views of the pins passing through planes B and B' and the main portion at plane A, respectively. Panels B-1 and B'-1 show slots with mating edges, and panels B-2 and B'-2 show slots with overlapping edges.

[0029] Figure 2 A schematic diagram of a bifurcated bracket as described herein is shown.

[0030] Figure 3 Panels A through C show the sequence of gradually unfolding (opening) the delivery catheter via a sliding actuation of the access catheter.

[0031] Figure 4 Panels A through D show the sequence of delivery and unfolding (opening) of the delivery catheter at the treatment site, and the deployment of the bifurcated stent.

[0032] Figure 5 A thruster with a capture element in an open configuration is shown.

[0033] Figure 6 Showing the alignment with the bifurcation bracket Figure 5 The thrusters.

[0034] Figures 7A to 7C The loading sequence for loading the bifurcated support into the pin of the delivery catheter is shown.

[0035] Figure 8 A through 8E illustrate the loading sequence for loading the bifurcated stent into the first lumen of the delivery catheter.

[0036] Figure 9 Panels A and B show the deployment sequence of the bifurcated support using the thrusters.

[0037] Figure 10 Panels A through H show different branching architectures. Detailed Implementation

[0038] Before describing the system and method of this invention, it will be understood that the invention is not limited to the specific systems, methods, or combinations described, as such systems, methods, and combinations can certainly vary. It should also be understood that the terminology used herein is not intended to be limiting, as the scope of the invention will be limited only by the appended claims.

[0039] As used herein, the singular form (“a”, “an”) and “the” include both the singular and plural indicators, unless the context clearly specifies otherwise.

[0040] As used herein, the terms “comprising / comprises” and “composed of” are synonymous with “including / includes” or “containing / contains”, and are inclusive or open-ended, and do not exclude additional undescribed components, elements, or method steps. It will be understood that the terms “comprising / comprises” and “composed of” as used herein include the terms “consisting of / consistsof” and “constituting”.

[0041] A description of a numerical range defined by endpoints includes all numbers and decimals falling into the corresponding range, as well as the endpoints described.

[0042] When referring to measurable values ​​such as parameters, quantities, durations of time, etc., the term “about” or “approximately” as used herein means to encompass a particular value and variations relative to that particular value of + / - 10% or less, preferably + / - 5% or less, more preferably + / - 1% or less, and even more preferably + / - 0.1% or less, provided that such variations are appropriate for implementation in the disclosed invention. It will be understood that the values ​​referred to by the modifier “about” or “approximately” are themselves specifically and preferably disclosed.

[0043] The terms “one or more” or “at least one” as used herein, such as one or more or at least one of a set of components, are self-evident. By further illustration, the terms particularly cover references to any one of the components, or to two or more of the components, such as, for example, any ≥3, ≥4, ≥5, ≥6 or ≥7 of the components, and at most all of the components.

[0044] All references cited in this specification are hereby incorporated in their entirety by reference. Specifically, the teachings of all references specifically referred to herein are incorporated by reference.

[0045] Unless otherwise specified, all terms used in this disclosure, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Further explanation of the terminology is provided through definitions to better understand the teachings of this invention.

[0046] The following paragraphs define different aspects of the invention in more detail. Each aspect thus defined may be combined with any other aspect or multiple aspects unless clearly indicated to the contrary. Specifically, any feature indicated as preferred or advantageous may be combined with any other feature or multiple features indicated as preferred or advantageous.

[0047] Throughout this specification, the reference to "one embodiment" or "implementation" means that a specific feature, structure, or characteristic described in conjunction with said embodiment is included in at least one embodiment of the invention. Therefore, the phrase "in one embodiment" or "in an embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments, as will be apparent to those skilled in the art from this disclosure. Moreover, while some embodiments described herein include some features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments, as will be understood by those skilled in the art. For example, any of the claimed embodiments in the appended claims can be used in any combination.

[0048] In this description of the invention, reference is made to the accompanying drawings, which form part of the invention and illustrate only specific embodiments in which the invention can be practiced. Parenthetical or bold reference numerals attached to corresponding elements are merely illustrative by way of example and are not intended to limit the corresponding elements. It should be understood that other embodiments can be used and structural or logical changes can be made without departing from the scope of the invention. Therefore, the following detailed description should not be considered limiting, and the scope of the invention is defined by the appended claims.

[0049] The terms “distal,” “distal,” or “…distal” and “proximal,” “proximal,” or “…proximal” are used throughout the specification and are generally understood in the field to mean orientation (proximal) or distance (distal) relative to the surgeon’s side of the device. Thus, “proximal,” “proximal,” or “…proximal” means the side facing the surgeon and therefore away from the patient. Conversely, “distal,” “distal,” or “…distal” means the side facing the patient and therefore away from the surgeon.

[0050] The first aspect relates to a delivery system (100) for a bifurcated support (200), the bifurcated support having a rod (226) and a pair of arms (220, 222), the delivery system comprising:

[0051] - Delivery catheter (110) comprising an elongated first tube (102) having a proximal end (20) and a distal end (30) and a bifurcation portion (114) at the distal end (30) configured to receive arms (220, 222), wherein a longitudinal slit (140) provided on the bifurcation portion (114) is configured for releasable passage of a bifurcation support (200) through the longitudinal slit.

[0052] It is used in the treatment of blood vessels in the body, specifically arteries.

[0053] The bifurcated support (200) is a support having a proximal end (20) and a distal end (30), the support comprising a rod portion (226) at the proximal end (20) that bifurcates into a pair of arms (220, 222) at the distal end, such as, for example Figure 2 As illustrated in the illustration. The stent lumen (230) extends from the proximal end (232) of the rod to the distal end of each arm (234, 236). The ends of the bifurcated stent (200) are preferably open to allow the passage of bodily fluids in place. The bifurcated stent (200) is flexible and may be compliant.

[0054] A bifurcation stent (200) can be used to treat aneurysms located at the bifurcation of a body vessel having a wall and a bifurcation that forms two dividing branches. An aneurysm with a neck may be located at an arterial bifurcation that communicates with the lumen of the body vessel at the bifurcation and may or may not communicate with one or both dividing branches. The aneurysm may surround one or both dividing branches.

[0055] The bifurcation stent (200) can be used to treat occlusions in the vessel wall. The occlusion may surround one or both branches.

[0056] According to one aspect, the occlusion material (e.g., clot, thrombus, embolus) is penetrated by the arm of the bifurcation stent (200), and the bifurcation stent (200) is retracted, thereby removing at least a portion of the occlusion material from the treatment site.

[0057] According to another aspect, the occlusion is opened by an inflatable balloon. This opening can be performed before or simultaneously with the deployment of the bifurcation stent (200). In the case of simultaneous deployment, the delivery catheter may accommodate additional tubing or lumen for the expansion of the inflatable balloon; and the balloon-expandable (non-self-expanding) bifurcation stent (200).

[0058] The bifurcation stent (200) may be in an expanding or compressible configuration. The compressible configuration is used to pass through the body's blood vessels within a delivery catheter (110), wherein the stent arms (220, 222) and stem (226) have a narrowed lateral cross-sectional profile. An expanding configuration is used after deployment; the stent arms and stem have an increased lateral cross-sectional profile. The expanding configuration contacts the inner luminal wall of the body's blood vessel. It should be understood that the bifurcation stent (200) may not be fully expanded upon placement; it is typically positioned in a transitional state between full expansion and full compression, wherein the bifurcation stent (200) applies radial forces to the vessel wall. Generally, when discussed herein, the expanding configuration may also be considered as implying the aforementioned transitional state of not being fully expanded.

[0059] The bifurcation support is preferably self-expanding. It is preferably biased in an expanded configuration; no force is required to maintain the expanded configuration. When an external radial force is applied, the bifurcation support arms (220, 222) and rod (226) can each be radially compressed, thereby reducing the transverse cross-sectional profile (e.g., diameter) of the support arms and rod in the compressed configuration. The self-expanding bifurcation support can be held in the compressed configuration within the first lumen (130) of the first tube (102), as described later below. The bifurcation support in the compressed configuration... Figure 4 As illustrated in panel A, the bifurcated support in the expanded configuration is... Figure 4 An example is shown in panel D. The self-expanding scaffold is preferably formed of shape memory materials such as nickel-titanium alloys, chromium-cobalt alloys, or biodegradable materials.

[0060] According to one aspect, the bifurcation stent can be balloon-expandable (non-self-expanding). A balloon-expandable bifurcation stent can be mounted on a balloon for delivery to the treatment site and actuation of expansion.

[0061] The bifurcated stent (200) may be further configured in either an open or folded configuration. A folded configuration is used to pass through the body's blood vessels within the access catheter (300), wherein the stent arms (220, 222) are closer together and typically have a substantially T-shaped profile. An open configuration is used after deployment within the body's blood vessels, wherein the stent arms (220, 222) are positioned more widely apart and typically have a substantially Y-shaped profile.

[0062] The bifurcation support (200) can be compliant and is biased into an open (“Y”) configuration. When force is applied, the support folds into a folded configuration. When the force is released, the bifurcation support (200) returns to the open (“Y”) configuration. The bifurcation support (200) can be held in a closed (T-profile) configuration within the second lumen (330) of the second tube (302), as described later below. The bifurcation support (200) in the closed configuration... Figure 4 As illustrated in panel A, the forked support in the configuration is opened. Figure 4 Example shown in panel B.

[0063] The bifurcated stent wall extends along the rod (226) at the proximal end (20) to each of the arms (220, 222) at the distal end (30), thereby defining a stent lumen. The stent lumen (230) is sized in an expanded configuration for the flow of bodily fluids such as blood. The stent lumen may be sized in a compressed configuration for the slidable passage of one or more, preferably two, guidewires. More specifically, the stent lumen (232) in the rod portion (226) may be sized in a compressed configuration for the slidable passage of two guidewires, and the stent lumens (234, 236) of the arms (220, 222) may be sized in a compressed configuration for the slidable passage of each guidewire.

[0064] The bifurcated support arms can have equal lengths in the non-folded state. Alternatively, the bifurcated support arms can have unequal lengths in the non-folded state. An exemplary configuration of the bifurcated support is shown in... Figure 10 , in panels A through G.

[0065] The stent wall can be permeable to blood flow or impermeable to blood flow. It can exhibit variable porosity along the length of the stent to allow it to be used as a stent for filling aneurysms (e.g., as part of a stent-assisted coiling technique) or as a flow diverter stent. The porosity can vary depending on its compression or expansion during deployment. An exemplary configuration of a bifurcated stent with a variable porosity arm (224') is shown in [illustration / description]. Figure 10 In panel H.

[0066] The bifurcation stent (200) may or may not be drug-eluting. According to one aspect, the bifurcation stent possesses an active pharmaceutical ingredient having antithrombotic, anticoagulant, endothelializing, cell migration-stimulating, or cell growth-stimulating properties. The active pharmaceutical ingredient may be provided on the inner and / or outer surfaces of the bifurcation stent (200).

[0067] Compared to the outer surface of the bifurcation stent (200), different active pharmaceutical ingredients can be provided on the inner surface. For example, the inner surface may have active pharmaceutical ingredients that promote vascular patency, while the outer surface may have active pharmaceutical ingredients that promote thrombus formation, coagulation, or healing.

[0068] According to one aspect, the bifurcated stent has an active pharmaceutical ingredient on its inner surface that has antithrombotic properties, or anticoagulant properties, or pro-endothelisation properties, or is a cell migration stimulant, or is a cell growth stimulant, and has an active pharmaceutical ingredient on its outer surface that has prothrombotic properties, or procoagulant properties, or pro-endothelisation properties, or is a cell migration stimulant, or is a cell growth stimulant.

[0069] The bifurcation stent (200) can be manufactured by braiding metal wire or by laser cutting techniques as known in the art. For aneurysm treatment, the stent allows blood flow to be redirected (i.e., diverted) and thus promotes thrombosis and occlusion of the medial side of the bifurcation aneurysm.

[0070] Typically, the delivery catheter (110) comprises an elongated first tube (102) having a proximal end (20) and a distal end (30) and a bifurcation portion (114) at the distal end (30). The bifurcation portion (114) comprises a first leg (120) and a second leg (122). The first leg (120) and the second leg (122) are connected to each other at a bifurcation point (124) and constitute the remainder of the first tube (102) proximal to the bifurcation point (124). The remainder of the first tube (102) proximal to the bifurcation portion (114) is also referred to as the main portion (112) of the first tube (102).

[0071] The first tubing (102) is provided with a first lumen (130). The first lumen (130) is fluidly connected to the proximal end (20) of the main portion (112) of the first tubing (102) and branches (134, 136) at the distal end (30), corresponding to the branch of the first tubing (120). The branched portion (114) of the first lumen (134, 136) is configured to receive the arms (220, 222) of the branched support (200). The main portion (112) of the first lumen (232) is configured to receive the rod (226) of the branched support (200) specifically adjacent to the branch point (124). The main portion of the first lumen (232) may be further configured for the passage of one or more guidewires, preferably two guidewires (one for each branched leg (120, 122)). The end of the delivery catheter (110) is preferably open for the passage of one or more guidewires.

[0072] The bifurcation portion (114) of the first tubing (102) receives the arms (220, 222) of the bifurcation stent (200). In the case that the bifurcation stent (200) is self-expanding, the first tubing (102) is adapted to maintain the bifurcation stent (200) in a contracted state. Resistance to expansion of the wall of the first tubing, particularly in the bifurcation portion (114), prevents the bifurcation stent from expanding, thereby maintaining it in a contracted state before deployment. After the bifurcation stent (200) is released from the first tubing (102) through the slits (140, 140', 140"), the stent expands and occupies the lumen of the bifurcation vessel.

[0073] The bifurcation portion (114) of the first tubing (102) has slits (140, 140', 140") configured for the passage of a bifurcation stent (200). The slits connect the bifurcation portion of the first lumen (134, 136) to the outside of the first tubing (102). The slits (140, 140', 140") may be radial relative to the central axis of each leg. After the first leg (120) and the second leg (122) have been positioned within the bifurcation of the body's blood vessel, the bifurcation portion of the first tubing (102) can releasably hold the bifurcation stent for deployment. The slits (140, 140', 140") may be further configured for the passage of a guidewire.

[0074] Preferably, the slots (140, 140', 140") extend from the first pin (120) to the second pin (122). More preferably, the slots extend from the distal (30) end of the first pin (120) in the proximal (20) direction and from the distal end of the second pin (122) in the proximal (20) direction, and connect where the corresponding pins (120, 122) meet. The slots (140, 140', 140") may intersect the central axis of the main portion (112) of the first tube (102). The slots (140', 140") on each pin may face each other. The slots (140', 140") may be straight and parallel to the central axis of the corresponding pin, or inclined to the central axis, or partially spiral. The slots may be continuous.

[0075] The slots (140, 140', 140") can be open or closed in their natural state. When closed, the slot edges are compliant to allow the bifurcated support to pass through. In the closed state, the slot edges can contact (e.g.) Figure 1 Panels B'-1, 142' and B-1, 142") or overlapping (e.g.) Figure 1 Panels B'-2, 144' and B-2, 144" are shown.

[0076] With the slot open, the width of the slot can be set to allow the bifurcated bracket to pass through easily, while providing sufficient resistance to the expansion of the wall to keep the self-expanding bifurcated bracket in the closed position. The slot (140, 140', 140") can occupy between 1% and 30% of the circumference of the pin (120, 122).

[0077] The slits (140, 140', 140") may be provided with one or more breakable seals configured to prevent the bifurcation support from passively passing through the slits and / or to prevent the expansion of the self-expanding bifurcation support. The breakable seals may be broken when the delivery conduit (110) retracts from the bifurcation support (200) or when the bifurcation support (200) is advanced using the pusher (500). The breakable seals may be formed through a reduced wall thickness section of the first tubing (102); the reduced wall thickness section may span all or part of the slit. The breakable seals may be interrupted by a section where the edge of the slit is formed by a non-cut section bridging the gap.

[0078] The gap can be formed by laser cutting, water cutting, or milling of the wall of the first tube in the bifurcation portion (114), which also allows the formation of a breakable seal by, for example, partial cutting to a certain depth and / or by providing an interruption (bridging) to the gap.

[0079] The bifurcation portion (114) of the first tube (102) is compliant and biased into an open (V-shaped) configuration. When an external force is applied, the bifurcation portion (114) can be converted into a folded configuration, wherein the corresponding distal ends of the first tube leg (120) and the second tube leg (122) are brought closer together. Upon release of the force, the bifurcation portion (114) returns to the open (V-shaped) configuration. This foldable nature allows the access conduit (300) to slide through the compression lumen (330). The bifurcation portion (114) of the first tube (102) in a closed configuration is illustrated in… Figure 3 In panel A, and with the bifurcation of the first tube in the open configuration illustrated... Figure 3 In panel C.

[0080] The controlled and gradual opening and / or folding of the bifurcation portion (114) of the first tubing can be actuated by retraction of the compressed second lumen (330) through the access conduit (300) or by forward movement through the compressed second lumen (as described in more detail later), i.e. by inserting or removing the sheath of the bifurcation portion (114) of the first tubing. Preferably, the access conduit (300) retracts while the first tubing (102) remains in a substantially fixed relationship relative to the treatment site. Advantageously, if it has not yet been satisfactorily deployed or positioned, the bifurcation portion (114) of the first tubing can be reinserted into the sheath and repositioned.

[0081] The first tube (102) may preferably be sized for slidable passage through, for example, the working channel of an endoscope or the second lumen of a second tube (described below). As a general guideline, for vascular applications, the maximum outer diameter of the main portion (112) of the first tube (102) may be equal to or not greater than 0.1F to 0.3F (0.05 mm to 0.10 mm).

[0082] As a general guideline, the maximum diameter of the first lumen (132) of the main portion (112) of the first pipe (102) may be equal to or not greater than 0.1F to 0.2F (0.04 mm to 0.07 mm).

[0083] As a general guideline, the length of the main portion (112) of the first tube (102) can be from 120 cm to 160 cm, depending on the application. The corresponding diameter and length can be set according to the location relative to the entry point, the size of the blood vessel to be treated, such as the size of the artery, the size of the aneurysm neck, and the anatomy.

[0084] The maximum outer diameter of the main portion (112) of the first tube (102) can be greater than the maximum outer diameter of the first pin (120) and the second pin (122). The maximum outer diameter of the first pin (120) can be the same as or different from the maximum outer diameter of the second pin (122). The corresponding diameter can be set according to the size of the blood vessel to be processed, such as the size of the artery or the size of the aneurysm neck.

[0085] As a general guideline, for vascular applications (e.g., intracranial), the maximum outer diameter of the first pin (120) or the second pin (122) of the first tube (102) may be equal to or not greater than 0.1F to 0.2F (0.04 mm to 0.07 mm).

[0086] As a general guideline, the maximum diameter of the first lumen (136, 134) of the first pin (120) of the first pipe (102) or the first lumen (136, 134) of the second pin (122) may be equal to or not greater than 0.09F to 0.18F (0.03mm to 0.06mm).

[0087] The length of the first pin (120) may be the same as or different from the length of the second pin (122). The corresponding length can be adjusted according to the size of the blood vessel to be treated, such as the size of the artery or the size of the aneurysm neck.

[0088] The lengths of the first pin (120) and the second pin (122) may be longer than the corresponding lengths of the first arm (220) and the second arm (222).

[0089] The first tubing (102) can be formed using an extrusion or non-extrusion process. The first tubing can be formed from a biocompatible material that provides the necessary flexibility, maneuverability, and strength. It may exhibit low or no radial expansion. Suitable biocompatible materials include, but are not limited to, polymers such as polypropylene, polyethylene, polyurethane, polyamide, polyimide, polyethylene terephthalate (PET) or polyesters and copolymers thereof, metals (stainless steel, nickel-titanium alloys), or combinations of metals and polymers. In a preferred embodiment, it is formed from a polymeric material that is polyamide, polyimide, stainless steel or nickel-titanium alloy, a combination or blend of these. The first tubing can be formed from a polymeric material (e.g., polyimide) reinforced with a braided or coiled metal (stainless steel or nickel-titanium alloy), the braided or coiled metal being disposed within the polyimide wall. For a first tubing formed by extrusion, it is preferably formed from polyamide. For a first tubing formed by non-extrusion, it is preferably formed from polyimide. The exterior may be coated to reduce friction during insertion or retraction. Examples of suitable friction-reducing coatings include Teflon.

[0090] The main portion (112) of the first tube (102) may be provided with a coil spring, which is at least partially disposed along its length to increase rigidity and maneuverability while maintaining flexibility. The coil spring is preferably disposed adjacent to the inner wall of the first lumen. A rubber layer may be provided to protect the coil spring. The rubber layer may have a friction-reducing coating, such as a hydrophilic polymer, to facilitate the passage of the guidewire through the first lumen. On the other hand, the bifurcation portion of the first tube lacks a coil spring; rigidity can be provided by the presence of a bifurcation support.

[0091] The delivery catheter (110) may be further provided with one or more expandable balloons. The expandable balloons can be used for the treatment of occlusion and / or for the opening of a balloon-expandable bifurcation stent. The expandable balloon can be advanced toward the treatment site through a first lumen (230) of the first tubing (102). The expandable balloon and associated catheter may be slidable relative to the delivery catheter (110). In a specific instance, the expandable balloon can be used to perform in-stent angioplasty in cases of incomplete deployment (expansion) of a bifurcation stent due to anatomical complexity. A bifurcation stent may be mounted on the balloon—one per stent arm—which allows for the deployment (expansion) of the balloon-expandable stent.

[0092] The first tubing (102) may include one or more additional lumens, for example, for the deployment of an expandable balloon, which may be used to perform in-stent angioplasty.

[0093] The treatment of arterial occlusion can be performed by: 1) deploying a bifurcation stent through the clot (or thrombus), 2) pausing for a period of time to allow the clot to penetrate the strut of the bifurcation stent, and 3) pulling the bifurcation stent back (retracting) together with the clot that has penetrated into its strut.

[0094] The delivery catheter (110) may be further provided with a flexible and slidable pusher (500) to assist in the distribution of the bifurcated support through the slit (140), such as, for example Figure 5 and 6 As shown in the diagram, the thruster (500) includes an elongated flexible rod (510) having proximal (20) and distal (30) ends, the elongated flexible rod being configured for passage through a first lumen (130) of a first tube (102). The thruster (500) may be slidable relative to the delivery conduit.

[0095] The propeller rod (510) may be formed of a biocompatible material that provides the necessary flexibility, maneuverability, and strength. Suitable biocompatible materials include, but are not limited to, polymers such as polypropylene, polyethylene, polyurethane, polyamide, polyimide, polyethylene terephthalate (PET), or polyesters and copolymers thereof. The exterior of the rod may be coated to reduce friction during passage through the first lumen (230) of the first tubing (102). Examples of suitable friction-reducing coatings include Teflon. The propeller rod may be formed of a hollow tubing or may be at least partially, preferably entirely, solid.

[0096] According to one aspect, the distal end (30) of the propeller rod (500) may be permanently attached to the proximal end (20) of the bifurcation support (200), for example, when the bifurcation support is used to treat vascular occlusion by removing a portion of the occlusive material, the bifurcation support (200) does not need to be released.

[0097] According to one aspect, the distal end (30) of the propeller rod (500) is provided with a capture element (520) releasably attached to the proximal end (20) of the bifurcation bracket (200). The capture element (520) can be provided in a fixed, slidable, and preferably rotatable relationship with the distal end of the propeller rod. The capture element (520) can be radially self-expanding, for example, a radially self-expanding claw or mesh with an open or folded configuration. The folded configuration is used for passage within a first lumen (130) of the first tube (102), wherein the peripheral edges of the capture element (520) are closer together, typically having a substantially “I”-shaped profile. The capture element (520) in the folded configuration is capable of gripping the proximal end (20) of the bifurcation bracket (200); once gripped, translation and preferably rotation of the propeller rod are transmitted to the bifurcation bracket (200). The open configuration is adopted after the deployment of the bifurcation support (200), with the peripheral edges set to be wider and typically having a substantially conical or dome shape. The capture element (520) in the open configuration releases the grip of the proximal end (20) of the bifurcation support (200).

[0098] The capturing element (520) may be compliant and biased into an open (conical or dome-shaped) configuration. Upon application of radial force, the capturing element (520) folds into a folded configuration. The capturing element (520) may be held in a closed (“I” profile) configuration within the first lumen (130) of the first tube (102). Upon release of radial force, the capturing element (520) returns to the open configuration. The capturing element (520) may adopt the open configuration after it has advanced through the gap (140) of the bifurcation portion (114) of the first tube. An example of the capturing element (520) in a closed configuration is shown below. Figures 7A to 7C In, and the capture element in the open configuration is exemplified in Figure 5 and 6 middle.

[0099] The advance of the thruster (500) in the distal (30) direction when the delivery conduit (110) is held in position, or the retraction of the delivery conduit (110) when the thruster (500) is held in position, allows the bifurcated support (200) to be deployed, i.e., pushed out from the slot. Figure 9 Panels A and B show the sequence in which the pusher (500) is held in a constant position as the delivery catheter (110) retracts proximally, thereby deploying the bifurcated support (200).

[0100] It should be noted that the pusher (500) can be used to load the bifurcated support (200) into the pins (120, 122) of the delivery conduit (110). The loading sequence is shown, for example... Figures 7A to 7C In the folded configuration, the bifurcated support (200) can be introduced into the proximal end (20) of the first lumen (130) of the main portion (112) of the first tube (102), and when gripped by the capturing element (520) in the closed configuration, it moves along as... Figure 7A The first lumen (130) of the main portion (112) shown advances in the distal (30) direction. Upon reaching the bifurcation portion (114) of the first tube (102), the bifurcation support (200) arms (220, 222) extend into the lumen (134, 136) of the bifurcation portion (114) of the first tube (102) and occupy the lumen. Figure 7B and 7C It should be understood that loading of the bifurcated stent (200) into the delivery catheter (110) can be performed via a pair of guidewires.

[0101] The delivery system (100) for the bifurcation stent may further include an access catheter (300) for delivering the delivery catheter (110) to the treatment site, such as, for example... Figure 3 As shown in panels A through C.

[0102] The access catheter (300) includes an elongated second tube (302) having a proximal end (20) and a distal end (30), the elongated second tube being provided with a second lumen (330) adapted to slidably receive a delivery catheter (110) or a first tube (102). The second tube (302) is configured to slidably receive a bifurcation portion (114) of the first tube (102) in a folded configuration.

[0103] The proximal (20) and distal (30) ends of the second tubing (302) are open. The second tubing (302) may be cylindrical, thus having a generally uniform external shape in the proximal region. It will be understood that the open proximal ends may be configured for connection to one or more hubs. One or more hubs, selectively having Luer fittings (such as Y-connectors), may mate with the proximal end of the access conduit or second tubing to facilitate the passage of the first tubing or delivery conduit, guidewire, or device to provide torque / longitudinal force through the first tubing.

[0104] As those skilled in the art will understand, the second tube (302) may preferably be sized for slidable passage through, for example, the working channel of an endoscope or through a body lumen, specifically a vascular system (via an introducer). As a general guideline, for vascular applications (e.g., intracranial), the maximum outer diameter of the second tube (302) toward the distal (in-place) end may be equal to or no greater than 4F to 6F (1.33 mm to 2 mm).

[0105] As a general guideline, the maximum diameter of the distal (in-place) end of the second lumen (330) may be equal to or not greater than 3.9F to 5.9F (1.30 mm to 1.97 mm).

[0106] As a general guideline, the length of the second tube (302) can be from 110cm to 150cm, depending on the application.

[0107] The second tubing (302) can be formed using an extrusion or non-extrusion process. The second tubing (302) can be formed from a biocompatible material that provides the necessary flexibility, maneuverability, and strength. Suitable biocompatible materials include, but are not limited to, polymers such as polypropylene, polyethylene, polyurethane, polyamide, polyimide, polyethylene terephthalate (PET) or polyesters and copolymers thereof, metals (stainless steel, nickel-titanium alloys), or combinations of metals and polymers. In a preferred embodiment, it is formed from a polymeric material that is polyamide, polyimide, stainless steel or nickel-titanium alloy, or combinations or blends thereof. The second tubing (302) can be formed from a polymeric material (e.g., polyimide) reinforced with a braided or coiled metal (stainless steel or nickel-titanium alloy), the braided or coiled metal being disposed within the polyimide wall. For a second tubing (302) formed by extrusion, it is preferably formed from polyamide. For a second tubing (302) formed by non-extrusion, it is preferably formed from polyimide. The exterior may be coated to reduce friction during insertion or retraction. Examples of suitable friction-reducing coatings include Teflon.

[0108] The second tube (302) may include a coil spring, which is at least partially disposed along its length to increase rigidity and maneuverability while maintaining flexibility. The coil spring is preferably disposed adjacent to the inner wall of the second lumen. A rubber layer may be provided to protect the coil spring. The rubber layer may have a friction-reducing coating, such as a hydrophilic polymer, to facilitate the passage of the first tube through the second lumen.

[0109] The second tubing (302) may contain one or more additional lumens, such as the deployment of an expandable balloon for occlusion treatment.

[0110] The delivery system (100) may further include a loader (600) configured to load the bifurcated support (200) into the delivery conduit (110), such as, for example... Figure 8 As shown in panels A through E.

[0111] The loader (600) includes an elongated third tube (602) having a proximal end (20) and a distal end (30), the elongated third tube having a third lumen (630) adapted to slidably receive a bifurcated support (200) in a folded configuration.

[0112] The distal end (30) of the third tubing (602) is configured to connect to the proximal terminal end of the delivery conduit (110), such that the first lumen (130) and the third lumen (630) are connected to form a continuous pathway for the bifurcated support (200) in a folded state to advance from the loader (600) to the delivery conduit (110). The proximal (20) and distal (30) terminal ends of the third tubing (602) are open. The distal end (30) of the third tubing (602) may have a connector (640) (e.g., a Luer fitting, a push connector, a narrowing section of the third tubing (602)) configured to connect to a complementary connector (140) (such as a hub) provided on the proximal end of the first tubing (102).

[0113] The third tube (602) may be cylindrical, thus having a generally uniform external shape in the distal region.

[0114] The proximal end (rod portion (226)) of the bifurcated support (200) is inserted into the distal end of the third (630) lumen, and the bifurcated support (200) retracts proximally (20) to fold the arm (220, 222) when the third tube (602) covers it. Figure 8 (Panels A to C).

[0115] Subsequently, the distal end (30) of the third pipe (602) is connected to the proximal end of the first pipe (102), so that the corresponding lumens (630, 130) form a continuous passage. Figure 8 Panel D). Subsequently, the bifurcated support (200) is advanced distally (30) so that it enters the first cavity (130) of the first tube (102). Figure 8 (Panel E). The loader (600) thus facilitates loading of the bifurcated support (200) from the proximal end of the delivery conduit (110), wherein the arms (120, 122) are oriented in the distal (30) direction.

[0116] It should be understood that a thruster (500) or other type of bar can be used to advance and retract the bifurcated support (200) relative to the loader (600).

[0117] The delivery system (100) may be provided with at least one guidewire, preferably two guidewires. The guidewires may have a shapeable distal end for intraluminal navigation.

[0118] There are two main types of catheters commonly used: the quick-exchange type (single-rail) and the transwire type (OTW). Transwire catheters use a long guidewire lumen extending from the proximal to the distal end of the catheter. Quick-exchange catheters use a distal guidewire lumen with side holes for the guidewire exiting towards the distal end. The fact that the guidewire is only received within the distal portion allows the catheter to be easily exchanged without the need for a guidewire extender or an excessively long guidewire. This delivery system can be easily adapted to guidewire deployment using either mode. The figures illustrate the OTW mode; however, it can be easily adapted to the quick-exchange operation mode within the skill level of a technician.

[0119] The delivery system (100) may include a delivery conduit (110) and one or more of the following elements:

[0120] -Bifurcation bracket (200),

[0121] -Connecting catheter (300),

[0122] - One or more, preferably two guidewires.

[0123] The delivery system (100) may be provided as a kit, the kit including a delivery conduit (110) and one or more of the following elements:

[0124] -Bifurcation bracket (200),

[0125] -Connecting catheter (300),

[0126] - One or more, preferably two guidewires.

[0127] The delivery system (100) may include a delivery conduit (110) and one or more of the following elements:

[0128] -Bifurcation bracket (200),

[0129] -Connecting catheter (300),

[0130] -Thruster (500),

[0131] -Loader (600), and

[0132] - One or more, preferably two guidewires.

[0133] The delivery system (100) may be provided as a kit, the kit including a delivery conduit (110) and one or more of the following elements:

[0134] -Bifurcation bracket (200),

[0135] -Connecting catheter (300),

[0136] -Thruster (500),

[0137] -Loader (600), and

[0138] - One or more, preferably two guidewires.

[0139] It should be understood that a delivery system (100) or kit may be supplied in which one or more of the delivery conduit (110) and components are not co-assembled.

[0140] A further aspect described herein relates to a method for delivering a bifurcation support to a treatment site using the delivery system (100) described herein, the method comprising:

[0141] - The access catheter (300) is advanced within the blood vessel to the treatment site via the access catheter (300), which is provided with a delivery catheter (110) loaded with a bifurcated stent (200).

[0142] -The delivery catheter (110) is gradually opened by retracting the access catheter (300), and

[0143] - Deploy the bifurcated support (200) by retracting the delivery catheter (110) through the gap (140).

[0144] The delivery system (100) can advance within the blood vessel along one or more, preferably a pair of guidewires. Typically, one guidewire is present for each arterial branch. The guidewire is positioned before the advancement of the delivery system (100).

[0145] A further aspect described herein relates to a method for treating an arterial aneurysm located at a vascular bifurcation using the delivery system (100) described herein, the method comprising:

[0146] -The delivery catheter (110) loaded with the bifurcated stent (200) is advanced within the blood vessel to the aneurysm site via the access catheter (300).

[0147] -The delivery catheter (110) is gradually opened by retracting the access catheter (300), such that each pin (120, 122) of the delivery catheter (110) is positioned within a branch of the vascular bifurcation, and

[0148] - A bifurcation stent (200) is deployed by retracting the delivery catheter (110) through the slit, such that each arm (220, 222) of the bifurcation stent (200) is positioned within the branch of the vascular bifurcation.

[0149] After deployment, the bifurcation support (200) is removed from the delivery system (100), for example, from the pusher (500), and the bifurcation support (200) remains in place.

[0150] A further aspect described herein relates to a method for treating an arterial occlusion located at a vascular bifurcation using the delivery system (100) described herein, the method comprising:

[0151] -The delivery catheter (110) loaded with the bifurcated stent (200) is advanced within the blood vessel to the occlusion site via the access catheter (300).

[0152] -The delivery catheter (100) is gradually opened by retracting the access catheter (300), such that each pin (120, 122) of the delivery catheter (110) is positioned within a branch of the vascular bifurcation, and

[0153] - A bifurcation stent (200) is deployed by retracting a delivery catheter (110) through a slit (140), such that each arm (220, 222) of the bifurcation stent (200) is positioned within a branch of the vascular bifurcation and one or both arms (220, 222) are positioned within an occlusive material (e.g., clot, thrombus, embolus).

[0154] -Retract the bifurcation support (200) together with at least a portion of the occluding material.

[0155] The retraction of the bifurcated support (200) can be achieved by a pusher rod attached to the bifurcated support (200).

[0156] Arterial aneurysms or arterial occlusions can be intracranial.

[0157] A further aspect described herein relates to a method for loading a bifurcated stent (200) into a delivery catheter (110), the method comprising the steps of:

[0158] - Insert the proximal end (20) of the bifurcated bracket (200) into the distal end (30) of the third (630) lumen of the loader (600).

[0159] -Retract the bifurcated support (200) to the proximal side (20) so that the arm (120, 122) is folded when the third tube (602) covers it.

[0160] The distal end (30) of the third tubing (602) is connected to the proximal end of the first tubing (102) of the delivery conduit (110), so that the corresponding lumens (630, 130) form a continuous passage.

[0161] The bifurcation support (200) is advanced distally (30) so that the bifurcation support enters the first cavity (130) of the first tube (102).

[0162] Using the method described, the bifurcated support (200) is loaded onto the proximal end of the delivery conduit (110), and the arms (120, 122) are oriented distally (30) for subsequent deployment. The method may use a thruster (500) to advance or retract the bifurcated support (200) relative to the loader (600).

[0163] Attached Figure

[0164] Figure 1 A delivery conduit (110) in an open configuration is shown, having a proximal end (20) and a distal end (30), the delivery conduit comprising a first tubing (102) provided with a first lumen (130, 132, 134, 136). The first tubing (102) branches at a bifurcation point (124) at the distal end (30), thereby forming a proximal main portion (112) and a bifurcation portion (114) provided with the first lumen (132), wherein the first lumen (134, 136) extends into each of the pins (120, 122) of the bifurcation portion (114). The bifurcation portion (114) is provided with a longitudinal slit (140) for passage of a bifurcation support (200).

[0165] Figure 1 Panels B and B' illustrate the transverse cross-sections passing through the first pin (120) and the second pin (122), respectively, as well as the corresponding gaps (140', 140") and corresponding portions of the first lumen (134, 136). Panel A illustrates the transverse cross-section passing through the main portion (112) of the first tube (102).

[0166] Figure 2 A bifurcated support (200) in an open (Y) configuration is shown, the bifurcated support having proximal (20) and distal (30) ends and including a rod portion (226) at the proximal end (20), the rod portion bifurcating at a bifurcation point (224) into a pair of arms (220, 222) at the distal end (30). A support lumen (230) extends from the proximal end (232) of the rod portion (226) to the distal end of each arm (234, 236).

[0167] Figure 3Panels A through C each show an access conduit (300) having proximal (20) and distal (30) ends, the access conduit comprising a second tube (302) provided with a second lumen (330), wherein the second lumen (330) slidably receives a first tube (102). In panel A, the bifurcation (114) of the first tube (102) is fully retracted within the second lumen (330), thereby assuming a folded configuration. In panel B, the bifurcation (114) of the first tube (102) is partially retracted within the second lumen (330), thereby assuming an open configuration. In panel C, the bifurcation (114) of the first tube (102) extends fully from the second lumen (330), thereby allowing the bifurcation (114) to assume a fully open configuration.

[0168] Figure 4 Panels A through D illustrate the delivery and deployment sequence into a portion of an artery (400) having proximal (20) and distal (30) ends, the artery bifurcating into two branches (422, 424) at the distal end (30), the branches exiting from the main portion (426) of the artery. The arterial lumen (430) has a corresponding main lumen portion (432) and luminal branches (434, 436). An aneurysm sac (430) has formed at the bifurcation of the branches (422, 424). In panel A, the delivery system (100) has advanced along the main portion (426) of the artery and approached the bifurcation portion of the artery (400). The delivery system (100) includes a bifurcation stent (200) loaded into the bifurcation portion of a delivery catheter (110), and an access catheter (300), the delivery catheter (110) being retracted into the access catheter (300) to maintain the prongs in a folded configuration. Typically, the delivery system (100) advances along two guidewires (not shown) (one guidewire per arm of the bifurcation stent) and through each of the arterial branches. In panel B, the access catheter (300) has been retracted relative to the delivery catheter (110), thereby extending the delivery catheter (110) and opening its pins (120, 122), each of which has been positioned into the lumen (434, 436) of a branch (422, 424) of the bifurcation artery (400). In practice, extension is performed gradually and in coordination with positioning. The delivery catheter (110) may be repeatedly reinserted and extended for optimal placement. In panel C, the delivery catheter (110) has been retracted relative to the bifurcation stent (200), thereby partially distributing the bifurcation stent (200) through the slit (140).

[0169] Each arm (220, 222) of the bifurcation stent (200) is positioned into the lumen (434, 436) of a branch (422, 424) of the bifurcation artery (400). The guidewire is preferably secured during dispensing when in use. In panel D, the delivery catheter (110) has been further retracted relative to the bifurcation stent (200). Each arm (220, 222) of the bifurcation stent (200) is fully deployed into the lumen (434, 436) of the arterial branch (422, 424), and the rod (226) is partially deployed. The stent mesh covers the wide neck of the aneurysm sac (430).

[0170] Figure 5 A thruster (500) with proximal (20) and distal (30) ends is shown. The thruster includes an elongated flexible rod (510) having a capture element (520) in an open configuration at the distal end (30) for releasable attachment to the bifurcation bracket (200) at the proximal end (20).

[0171] Figure 6 Show Figure 5 The thruster (500) wherein the capture element (520) in the open configuration is in close contact with the bifurcated support (200) and before capture.

[0172] Figures 7A to 7C The loading sequence for loading the bifurcated support (200) into the pins (120, 122) of the delivery catheter (110) is shown. Figure 7A In the folded configuration, the bifurcated support (200) is gripped by the capturing element (520) in the closed configuration, and advances in the distal (30) direction by pushing the elongated flexible rod (510) along the first lumen (130) of the main portion (112) of the first tube (102) in the distal direction. Figure 7B In this configuration, the bifurcated support (200) arms (220, 222) begin to extend into and occupy the lumens (134, 136) of the bifurcation portion (114) of the first tube (102). Figure 7C In the middle, the bifurcation bracket (200) is fully loaded into the bifurcation portion (114) of the first tube (102).

[0173] Figure 8Panels A through E illustrate the loading sequence for loading the bifurcation support (200) into the delivery conduit (110) such that the arms (220, 222) are aligned distally. The proximal end (rod portion (226)) of the bifurcation support (200) is inserted into the capture element (520) of the pusher (500) in the open configuration (panel A). The pusher (500) is retracted proximally (20) into the distal end of the third lumen (630) so that the capture element (520) folds and grips the rod portion (226) of the bifurcation support (200) (panel B). The pusher (500) is further retracted proximally (20) so that it folds as the third tubing (602) covers the arms (220, 222) of the bifurcation support (200). Figure 8 (Panels A to C). After the bifurcated support (200) arms (220, 222) have been closed, the distal end (30) of the third tube (602) is connected via a connector (640) to the proximal end of the first tube (102) provided with a complementary connector (140), thereby forming a continuous passage in the corresponding lumens (630, 130). Figure 8 Panel D). Subsequently, by pushing the pusher (500) forward, the bifurcation bracket (200) is advanced to the distal side (30), causing the bifurcation bracket (200) to enter the first cavity (130) of the first tube (102). Figure 8 Panel E).

[0174] Figure 9 Panels A and B show the relationship with Figure 4 The sequence shown is similar to the deployment sequence into a portion of the artery (400), where the bifurcation stent (200) is held or advanced relative to the delivery catheter (110) using a thruster (500). In panel A, the pins (120, 122) of the delivery catheter (110) have been positioned into the lumen (434, 436) of the branches (422, 424) of the bifurcation artery (400). The delivery catheter (110) has been partially retracted relative to the bifurcation stent (200), which is held in place, allowing the thruster rod (500) to be held fixed relative to the treatment site, thereby partially dispensing the bifurcation stent (200) through the slit (140). In panel B, the delivery catheter (110) has been further retracted relative to the thruster rod (500) and the bifurcation stent (200). Each arm (220, 222) of the bifurcated stent (200) is fully deployed into the lumen (434, 436) of the arterial branch (422, 424), and the strut (226) is partially deployed. The stent mesh covers the wide neck of the aneurysm sac (430).

[0175] Figure 10Panels A through H show different bifurcation stent (200) configurations based on the size of the arterial branches (422, 424). Compared to panel A, the lengths of the bifurcation stent arms are different in panels B and C; the lengths of the bifurcation stent rods are different in panel D; the branching angles are different in panel E, and the diameter of the left branch of the bifurcation stent is also different; the branching angles are different in panel F, and the diameter of the right branch of the bifurcation stent is also different; the branching angles are different in panel G, and the diameter and length of the branches are also different. In panel H, similar to panel G, the porosity of the right stent branch varies at region 224'.

Claims

1. A delivery system (100) for a bifurcated stent (200) having a stem (226) and a pair of arms (220, 222), the delivery system comprising a delivery catheter (110) including an elongated first tubing (102) having a proximal end (20) and a distal end (30) and a bifurcated portion (114) at the distal end (30) configured to receive the arms (220, 222), wherein a longitudinal slit (140) disposed on the bifurcated portion (114) is configured for releasable passage of the bifurcated stent (200) therethrough, edges of the slit being either separated or in contact, and the bifurcated portion being made of a compliant material allowing for repeated opening and closing of the slit, wherein the longitudinal slit extends from a first leg (120) to a second leg (122) of the bifurcated portion (114), wherein the slit (140) occupies between 1% - 30% of a circumference of each leg (120, 122).

2. The delivery system of claim 1, wherein the bifurcated portion (114) of the first tubing (102) includes a first leg (120) and a second leg (122) each configured for passage through a branch (422, 424) of a bifurcated body vessel.

3. The delivery system (100) of claim 1, further comprising an access catheter (300) including an elongated second tubing (302) having a proximal end (20) and a distal end (30), the elongated second tubing being provided with a second lumen (330) adapted to slidably receive the first tubing (102) and configured to control gradual opening or folding of the bifurcated portion (114) of the first tubing (102) in response to slidable relative displacement of the first tubing (102) and second tubing (302).

4. The delivery system of claim 3, wherein the delivery catheter (110) is configured for a wire-guided or rapid-exchange mode of operation.

5. The delivery system (100) of claim 1, further comprising the bifurcated stent (200) being self-expanding or balloon-expandable, wherein the bifurcated stent (200) is drug-eluting.

6. The delivery system (100) of claim 1, further comprising a pusher (500) comprising an elongated flexible rod (510) having a proximal end (20) and a distal end (30), and a capture element (520) at the distal end (30) for releasable attachment to the bifurcated stent (200) at a proximal end (20) thereof, the capture element (520) being radially self-expandable to assume an open or collapsed configuration, wherein the collapsed configuration is configured for passage within a first lumen of the first tubing (102) and the capture element (520) has a peripheral edge closer together to grip the proximal end (20) of the bifurcated stent (200), and wherein the open configuration is configured for releasing the bifurcated stent (200).

7. The delivery system (100) of claim 1, further comprising a loader (600) for loading the bifurcated stent (200) into the delivery catheter (110), the loader comprising an elongated third tubing (602) having a proximal end (20) and a distal end (30), the elongated third tubing being provided with a third lumen (630) adapted to slidably receive the bifurcated stent (200) in a collapsed configuration, wherein the distal end (30) of the third tubing (602) is configured to be connected with a proximal end of the delivery catheter (110) such that a first lumen of the first tubing (102) and the third lumen (630) are connected to form a continuous passage for the bifurcated stent (200) in the collapsed configuration to advance from the loader (600) to the delivery catheter (110).

8. A kit comprising the delivery catheter (110) as defined in any one of claims 1 to 2, and one or more of: - the access catheter (300) as defined in claim 3 or 4, - the bifurcated stent (200) as defined in claim 5, - the pusher (500) as defined in claim 6, - the loader (600) as defined in claim 7, and - one or more guidewires.

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