Endovascular systems and methods of delivering tubular implants

Abstract

This invention provides an endovascular system and a method for delivering a tubular implant. The endovascular system includes a delivery device operable to deliver a tubular implant through a catheter. The delivery device includes a delivery wire, a set of stops, a connector, and a protective sheath. The set of stops includes a distal stop and a proximal stop fixedly attached to the delivery wire. The connector is disposed between the distal and proximal stops. The protective sheath covers at least an end portion of the tubular implant. A method for delivering the tubular implant is also described.

Description

Technical Field

[0001] This application generally relates to medical devices and methods of using medical devices for treating diseases. Specifically, various embodiments of intravascular systems, delivery devices, and methods for delivering implants to treatment sites, such as in a patient's cerebral blood vessels, are described. Background Technology

[0002] Stents, or flow-diverting stents, are commonly used in endovascular interventions to treat vascular diseases. Stents can be constructed from patterned cut tubes or braided wires or filaments. In cerebrovascular interventions, self-expanding braided stents are often used due to their desired resheathability, conformability, and radial force. Braided stents typically consist of a tubular or cylindrical structure constructed from multiple wires or filaments interwoven or braided in a repeating pattern.

[0003] Regardless of the stent's construction, a stent to be implanted in a cerebral blood vessel needs to be delivered through the neurovascular system in a collapsed state and then allowed to expand to the target vessel size. Stent delivery is typically achieved by compressing or confining the stent within a sheath or catheter and mounting it on a delivery system to facilitate stent movement.

[0004] In traditional delivery methods, the delivery system is attached to the compressed stent at the proximal end. Advancing the stent distally requires pushing it, while retraction requires pulling it proximally; both actions (pushing and pulling) originate from the proximal end of the stent. In some traditional delivery systems, bumpers are positioned at both the proximal and distal ends of the stent. The stent is advanced by pushing the bumpers at the proximal end, and retracted by pushing the bumpers against the distal end.

[0005] Stent delivery using conventional methods can often be difficult due to the tortuosity of cerebral vascular anatomy and the need for stents with large post-expansion diameters or high radial forces. Traditional systems typically require excessive force and effort to deliver stents and have encountered various other problems.

[0006] Therefore, despite the progress made in vascular intervention, there remains a general need to improve delivery systems and methods to overcome these and other problems experienced by conventional methods. Summary of the Invention

[0007] In one aspect, embodiments of the present disclosure are characterized by an endovascular system. Generally, embodiments of the endovascular system include a catheter, a tubular implant, and a delivery device. The tubular implant has a collapsed state for placement within the lumen of the catheter and an expanded state when not constrained by the catheter. The delivery device is operable to advance and / or retract the tubular implant relative to the catheter. The delivery device includes: a delivery wire, a first set of stops, a first coupling, a second set of stops, and a second coupling, the first set of stops including a distal stop and a proximal stop fixedly attached to the delivery wire, the first coupling disposed between the distal and proximal stops of the first set, the second set of stops including a distal stop and a proximal stop fixedly attached to the delivery wire, and the second coupling disposed between the distal and proximal stops of the second set. A first connector is configured to contact the distal portion of a tubular implant within the lumen of the catheter and apply a radially outward force to the distal portion to hold the tubular implant within the lumen of the catheter. A second connector is configured to contact the proximal portion of the tubular implant within the lumen of the catheter and apply a radially outward force to the proximal portion to hold the tubular implant within the lumen of the catheter. A first proximal stop is configured to engage the first connector when the delivery wire is advanced to apply a translational force in the distal direction to the first connector, thereby generating a distally tensile force on the tubular implant portion proximal to the distal portion of the tubular implant. A second distal stop is configured to engage the second connector when the delivery wire is retracted to apply a proximally translated force to the second connector, thereby generating a proximal tensile force on the tubular implant portion distal to the proximal portion of the tubular implant.

[0008] In another aspect, embodiments of this disclosure are characterized by an endovascular system. Generally, embodiments of the endovascular system include a catheter, a tubular implant, and a delivery device. The tubular implant has a collapsed state for placement within the lumen of the catheter and an expanded state when not constrained by the catheter. The delivery device is operable to advance and / or retract the tubular implant relative to the catheter. The delivery device includes a delivery wire, a set of stops including a distal stop and a proximal stop fixedly attached to the delivery wire, and a connector disposed between the set of distal and proximal stops. The connector is configured to contact a distal portion of the tubular implant within the lumen of the catheter and apply a radially outward force to the distal portion to hold the tubular implant within the lumen of the catheter. The proximal stops of the set are configured to engage the connector when the delivery wire is advanced to apply a translational force in the distal direction to the connector, thereby generating a distally tensile force on the portion of the tubular implant proximal to the distal portion of the tubular implant.

[0009] In another aspect, embodiments of this disclosure are characterized by a method for delivering a tubular implant within the lumen of a catheter. Generally, embodiments of this method include the steps of: applying a translational force in a distal direction to a distal portion of the tubular implant, thereby generating a tensile force on a portion of the tubular implant proximal to the distal portion of the tubular implant; and applying a translational force in a distal direction to the proximal portion of the tubular implant.

[0010] In another aspect, embodiments of this disclosure are characterized by an endovascular system. Generally, embodiments of the endovascular system include: a catheter having a lumen; a tubular implant having a collapsed state for placement within the lumen of the catheter and an expanded state when not constrained by the catheter; and a delivery device operable to deliver the tubular implant through the catheter. The delivery device includes: a delivery wire having a distal segment and a proximal segment; a set of stops including a distal stop and a proximal stop respectively fixedly attached to the distal segment of the delivery wire; a connector disposed between the distal and proximal stops and configured to apply a radially outward force to a distal portion of the tubular implant within the lumen of the catheter to grasp the tubular implant; and a protective sheath including a first end portion fixedly connected to the distal segment of the delivery wire and a second end portion enclosing at least a distal portion of the tubular implant within the lumen of the catheter. The connector is provided with a through opening that allows the distal segment of the delivery wire to pass through, and the through opening is configured to allow the delivery wire to slide longitudinally relative to the connector within the lumen of the catheter, thereby allowing the proximal stop and / or the distal stop to engage the connector and apply a translational force to the connector to advance and / or retract the tubular implant, and allowing the delivery wire to rotate relative to the connector to thereby remove the protective sheath from the tubular implant.

[0011] In another aspect, embodiments of this disclosure are characterized by a method for delivering a tubular implant. Generally, embodiments of the method include the step of positioning an endovascular system within a patient's blood vessel. The endovascular system includes: a catheter having a lumen, a tubular implant constrained within the lumen of the catheter, and a delivery device. The delivery device includes: a delivery wire; a set of stops including a distal stop and a proximal stop fixedly attached to the delivery wire; a connector disposed between the distal and proximal stops and configured to contact and apply a radially outward force to the distal portion of the tubular implant within the lumen of the catheter to grasp the tubular implant; and a protective sheath including a first end portion fixedly connected to the delivery wire and a second end portion enclosing at least a distal portion of the tubular implant within the lumen of the catheter. The method further includes the steps of: advancing or withdrawing the tubular implant by relative movement of the catheter and the delivery wire to allow the proximal stop to engage the connector and apply a translational force to the connector, thereby removing the end portion of the tubular implant, which is covered by the second end portion of the protective sheath, from the lumen of the catheter; and rotating the delivery wire to allow the protective sheath to twist, thereby removing the second end portion of the protective sheath from the end portion of the tubular implant.

[0012] The content of this invention is provided to present selected aspects and embodiments of the invention in a simplified form, and is not intended to identify key features or essential characteristics of the claimed subject matter, nor to help determine the scope of the claimed subject matter. The selected aspects and embodiments are merely intended to provide the reader with an overview of certain forms the invention may take, and are not intended to limit the scope of the invention. Other aspects and embodiments of the invention are described in the Detailed Description section.

[0013] These and various other aspects, embodiments, features, and advantages of this disclosure will be better understood by taking into account the accompanying drawings and by reading the following detailed description. Attached Figure Description

[0014] Figure 1 This is a simplified illustration of an example intravascular system according to an embodiment of the present disclosure.

[0015] Figure 2 This is a simplified illustration of an example delivery apparatus according to an embodiment of the present disclosure.

[0016] Figure 3 This is a schematic diagram illustrating an example delivery device according to an embodiment of the present disclosure for advancing a tubular implant.

[0017] Figure 4 This is a schematic diagram illustrating an example delivery device according to an embodiment of the present disclosure for retracting a tubular implant.

[0018] Figure 5 This is a simplified illustration of an example delivery apparatus according to an alternative embodiment of the present disclosure.

[0019] Figure 6 An example application of the endovascular system of this disclosure for treating aneurysms in the cerebrovascular system is described according to embodiments of this disclosure.

[0020] Figure 7 This is a flowchart illustrating an example method according to an embodiment of the present disclosure.

[0021] Figure 8 This is a simplified illustration of an example intravascular system according to an alternative embodiment of the present disclosure.

[0022] Figure 9 This is a simplified illustration of an example delivery apparatus according to an alternative embodiment of the present disclosure.

[0023] Figure 10 This is a flowchart illustrating an example method according to an embodiment of the present disclosure.

[0024] Figure 11 This is a schematic diagram illustrating an example method of delivering a tubular implant according to an embodiment of the present disclosure.

[0025] Figure 12 This is a schematic diagram illustrating an example method of delivering a tubular implant according to an embodiment of the present disclosure. Detailed Implementation

[0026] Referring to the accompanying drawings, various embodiments of intravascular systems, delivery devices, and methods will now be described. The drawings are intended to facilitate the description of embodiments of this disclosure and are not necessarily drawn to scale. Certain specific details may be set forth in the drawings to provide a thorough understanding of this disclosure. It will be apparent to those skilled in the art that some of these specific details may not be used to implement embodiments of this disclosure. In other instances, structures, components, systems, materials, and / or operations commonly associated with known medical means may not be shown or described in detail to avoid unnecessarily obscuring the description of embodiments of this disclosure.

[0027] Embodiments of this disclosure provide an endovascular system including a delivery device operable to advance and / or retract a tubular implant in a catheter with reduced resistance. The delivery device allows the tubular implant to be pulled during advancement and retraction. The pulling force can cause a slight diameter contraction of the implant, thereby reducing overall static friction between the implant and the catheter. For example, in one embodiment of this disclosure, the delivery device utilizes a distal coupling feature and a proximal coupling feature, each of which contacts or grips an end of a luminal stent constrained in the catheter. The distal coupling feature allows for the generation of a distally pulling force, thereby facilitating stent advancement through the catheter. The proximal coupling feature allows for the generation of a proximal pulling force, thereby facilitating stent retraction or re-sheathing. The inventive features of this disclosure ensure that some tension is applied to the stent during both advancement and retraction.

[0028] Figure 1 An endovascular system 100 according to an embodiment of the present disclosure is depicted. In a broad overview, the exemplary endovascular system 100 includes an elongated tubular member 102 having a lumen 104, a tubular implant 120 disposed in the lumen 104 of the tubular member 102, and a delivery device 150 operable to deliver and / or deploy the tubular implant 120 to a target site within a patient. The delivery device 150 generally includes an elongated delivery wire 152, one or more sets of stops 154, 156, and one or more connecting features 158, 160 respectively disposed between one or more sets of stops 154, 156. One or more connecting features 158, 160 are configured to contact a portion of the implant 120 and apply a radially outward force to said portion of the implant 120 to grip the implant 120 within the lumen 104 of the tubular member 102. As will be described in more detail below, the arrangement of one or more connecting features 158, 160 with one or more sets of stops 154, 156 can produce on the tubular implant 120: a distal pulling force to assist the advancement of the tubular implant 120, and / or a proximal pulling force to assist the retraction of the tubular implant 120.

[0029] refer to Figure 1The elongated tubular member 102 may be in the form of a sheath, catheter, microcatheter, or any other suitable tubular form. For ease of description, the term "catheter" may be used interchangeably with the phrase "tubular member" herein. The catheter 102 includes a proximal portion 106, which may remain outside the patient's body and be accessible to the user or physician when the endovascular system 100 is in use. The size and dimensions of the distal portion 108 of the catheter 102 may be configured to reach remote locations within the patient's vascular system, such as in cerebral vessels adjacent to aneurysms, bifurcation vessels, occlusions in blood vessels, etc. The lumen 104 of the catheter 102 may be configured to accommodate a tubular implant 120 and a delivery device 150, which includes stops 154, 156 and connecting features 158, 160. Although not explicitly shown, the catheter 102 may include one or more segments or regions, each segment or region may have different constructions and / or characteristics. For example, the distal portion 108 of catheter 102 may include a flexible segment or region including a coil that provides appropriate bending or deflection. The flexible distal portion 108 allows the endovascular system 100 to navigate more easily through tortuous areas of the vascular system to remote locations within the patient. The proximal portion 106 may be constructed of a rigid material, such as a rigid metal hypertube, to provide structural stability and sufficient maneuverability. Typically, catheter 102 or segments of catheter 102 may be constructed of a suitable biocompatible polymer, metal, or a combination thereof. The outer diameter of the distal portion 108 of catheter 102 may be smaller than the outer diameter of the proximal portion 106 to reduce the profile of the distal portion 108 and facilitate navigation through tortuous vascular systems. Although not shown, catheter 102 may include one or more markers that can be visualized, for example, via fluoroscopy, to assist a physician in manipulating the endovascular system 100. The inner and outer diameters of the catheter 102 at the distal portion 108 can be appropriately selected based on the application. For example, for applications treating cerebral aneurysms, the catheter or microcatheter 102 may have an inner diameter ranging from 0.0165 inches to 0.040 inches to deliver a blood flow guiding stent of appropriate size to a target site in the brain anatomy or distal cerebral blood vessels.

[0030] refer to Figure 1The tubular implant 120 can be any suitable implant adapted to the delivery device 150 of this disclosure. For example, the tubular implant 120 can be an embolic device, such as a stent, a flow-directing stent, or an intrasaccular device for treating cerebral aneurysms. The tubular implant 120 can also be a flow restoration device or a thrombus removal device for treating conditions in the vascular system or other target sites of the body. The tubular implant 120 can be expandable, having a collapsed state when compressed or constrained within the lumen 104 of the catheter 102, and an expanded state when unconstrained or deployed at the treatment site. As shown, the tubular implant 120 includes a distal portion 122 and a proximal portion 124.

[0031] The tubular implant 120 may include a braided structure or a patterned cut structure. The braided or patterned cut structure may be a closed-cell design, in which repeating loop structures are connected at all strut joints. The braided or patterned cut structure may also be an open-cell scaffold design, in which some joints between the repeating loop structures are removed.

[0032] An exemplary tubular implant 120 includes a braided scaffold constructed from multiple wires or filaments 126. The multiple filaments 126 may be braided, woven, or interlaced in a suitable pattern. For example, the multiple filaments 126 may extend clockwise in a helical or spiral configuration, and may extend counterclockwise in a helical or spiral configuration to form multiple intersecting segments and define multiple units of a radially expandable body. The braided scaffold 120 may be a closed-unit design. The filaments 126 constructing the braided scaffold 120 may be metallic or polymeric. The filaments 126 may be radiopaque or non-radiopaque, or at least one or more of the filaments 126 constituting the scaffold 120 may be radiopaque. Depending on the application, the braided scaffold 120 may include about 40 to about 96 filaments. The filaments 126 may have a diameter ranging from 0.0008 to 0.0030 inches. The filaments 126 may have shape memory properties and / or may be heat-set to form a self-expanding scaffold 120. In its expanded state, depending on the application, the braided stent 120 can have a maximum diameter ranging from 1.0 mm to 10 mm. For the treatment of cerebral aneurysms, the braided stent 120 can be configured with a flow-directing device having a pore size and / or density suitable for interrupting or redirecting blood flow near the neck of the aneurysm, thereby causing occlusion of the aneurysm while allowing blood to flow in the carrier vessel and its branches.

[0033] Due to its interwoven helical structure, the filaments 126 comprising the support 120 can adjust their position and / or orientation when the support 120 is subjected to external forces. For example, when tension is applied to the braided support 120 along its longitudinal axis, the helical filaments 126 reorient themselves to align with the direction of the tension, thereby causing a decrease in the support diameter as the support 120 elongates or stretches. When compression is applied to the braided support 120 along its longitudinal axis, the helical filaments 126 reorient themselves to be perpendicular to the direction of the compressive load, thereby causing an increase in the support diameter as the support 120 contracts in length.

[0034] To deliver a braided stent to the target site, a common method is to attach the proximal end of the stent to the delivery device. According to this method, advancing the stent distally requires pushing it, while retracting it proximally requires pulling it, both of which occur from the proximal end. Another method utilizes buffers positioned proximally and distally on the stent, respectively. The stent, constrained in the catheter, is advanced by contact with the buffer located proximally, or retracted by contact with the buffer located distally. In conventional methods, thrust is used to advance or retract the stent. However, when the stent is advanced and / or retracted, the thrust on the stent and the frictional force along the stent create an overall compressive force on it. This compressive force raises the normal force between the expanding stent and the catheter constraining it, resulting in increased static friction along the stent until sufficient thrust is applied to overcome the friction and move the stent forward or backward. Essentially, advancing and / or retracting the stent by pushing involves increased friction and requires a greater thrust before the stent can move.

[0035] Embodiments of this disclosure utilize the properties of braided stents or closed-cell stents to reduce the force required to move the stent during delivery. The use of distal coupling features, or a combination of distal and proximal coupling features, allows the braided stent constrained in the catheter to be pulled in the intended direction of movement, resulting in a slight reduction in stent diameter compared to conventional push-based delivery systems, thereby reducing overall static friction.

[0036] Figure 2An exemplary delivery device 150 according to an embodiment of the present disclosure is depicted. As shown, the exemplary delivery device 150 includes an elongated delivery wire 152, a first set of stops 154a, 154b fixed to the delivery wire 152, a first connector 158 disposed between the first set of stops 154a, 154b, a second set of stops 156a, 156b fixed to the delivery wire 152, and a second connector 160 disposed between the second set of stops 156a, 156b. The first connector 158 is positioned adjacent to the distal portion 122 of the tubular implant 120 and is configured to contact the tubular implant 120 and apply a radially outward force to the tubular implant 120 to hold the implant 120 in the lumen 104 of the catheter 102. The second connector 160 is positioned adjacent to the proximal portion 124 of the tubular implant 120 and is configured to contact the tubular implant 120 and apply a radially outward force to hold the implant 120 within the lumen 104 of the catheter 102. As will be described in more detail below, the arrangement of the first connector 158 and the first set of stops 154a, 154b allows the first connector 158, which holds the distal portion 122 of the tubular implant 120, to generate a distally pulling force on a portion 123 of the implant 120 proximal to the distal portion 122 of the implant 120, thereby facilitating the advancement of the implant 120 away from the catheter 102. The arrangement of the second connector 160 and the second set of stops 156a, 156b enables the second connector 160, which grips the proximal portion 124 of the tubular implant 120, to generate a proximal pulling force on the portion 123 of the implant 120 distal to the proximal portion 124 of the implant 120, thereby helping the implant 120 to retract back into the catheter 102.

[0037] refer to Figure 2The elongated delivery wire 152 has a proximal portion 152a, a distal portion 152b, and a length extending between the proximal and distal portions 152a. When the delivery device 150 is in use, the proximal portion 152a of the delivery wire 152 can remain outside the patient's body and is accessible to the physician. The proximal portion 152a, which can be coupled to a handle, can be controlled by the user during operation. The distal portion 152b of the delivery wire 152 can be coupled to a first set of stops 154a, 154b, a second set of stops 156a, 156b, and is loaded with the tubular implant 120 to be delivered. Although not specifically shown, the distal portion 152b of the delivery wire 152 may include, for example, a segment or region of a coil to provide appropriate bending or deflection. One or more markers may also be coupled to the delivery wire 152 to assist the physician in operating the delivery device 150 via fluoroscopy. The delivery wire 152 may be constructed of a suitable metal, such as stainless steel, nickel, titanium, nitinol, metal alloys, biocompatible polymers, shape memory polymers, hyaluronic acid tubes, or any combination thereof.

[0038] refer to Figure 2 The first set of stops 154a, 154b may include a stop 154a at the distal end of the first connector 158 and a stop 154b at the proximal end of the first connector 158. The distal stop 154a and the proximal stop 154b of the first set may be fixedly attached to the distal portion 152b of the delivery wire 152 and may therefore be advanced, retracted, and / or rotated together with the delivery wire 152. The dimensions of the first set of stops 154a, 154b may be configured such that they do not directly contact the tubular implant 120 in the lumen 104 of the catheter 102, or do not generate sufficient frictional force to advance or retract the implant 120 constrained in the lumen 104 of the catheter 102 via direct contact with the tubular implant 120. In some embodiments, the dimensions of the first set of stops 154a, 154b are configured such that their cross-section is smaller than the cross-section of the first connector 158.

[0039] The proximal stop 154b of the first group can be configured to engage the first connector 158 when the delivery wire 152 is advanced, to apply a thrust to the first connector 158 from the proximal side. For example, the proximal stop 154b of the first group may include a planar distal surface configured to engage the planar proximal surface of the first connector 158. Other configurations and shapes of the engagement surfaces between the proximal stop 154b of the first group and the first connector 158 are possible and will be understood by those skilled in the art. These and other configurations and shapes of the engagement surfaces may be planar or curved, two-dimensional or three-dimensional, and the scope of this disclosure is not limited to any particular configuration or shape of the engagement surfaces between the proximal stop of the first group and the first connector. When the delivery wire 152 is advanced, the proximal stop 154b of the first group engages the first connector 158 and applies a thrust to the first connector 158 in a distal direction. The force applied by the proximal stop 154b of the first group can be transmitted to the distal portion 122 of the tubular implant 120 held by the first connector 158, thereby generating a pulling force on the portion 123 of the tubular implant 120 proximal to the distal portion 122 of the implant 120 (e.g., the portion 123 of the implant 120 between the first connector 158 and the second connector 160). Additionally or optionally, the distal stop 154a of the first group can be configured to engage the first connector 158 when the delivery wire 152 is retracted. The distal stop 154a of the first group may include a proximal surface for engaging the first connector 158, which may be planar or curved, or two-dimensional or three-dimensional in construction and shape. When the tubular implant 120 is withdrawn or re-entered into the cannula, the distal stop 154a of the first group can engage the first connector 158 and apply a thrust to the first connector 158 from the distal side in the proximal direction, as will be described in more detail below.

[0040] refer to Figure 2 The second set of stops 156a, 156b may include a stop 156a at the distal end of the second connector 160 and a stop 156b at the proximal end of the second connector 160. The distal and proximal stops 156a and 156b of the second set may be securely attached to the delivery wire 152 and thus may be advanced, retracted, and / or rotated together with the delivery wire 152. The dimensions of the second set of stops 156a, 156b may be configured such that they do not directly contact the tubular implant 120 in the lumen 104 of the catheter 102, or do not generate sufficient frictional force to retract or advance the implant 120 constrained in the lumen 104 of the catheter 102 via direct contact with the tubular implant 120. In some embodiments, the dimensions of the second set of stops 156a, 156b are configured such that their cross-section is smaller than the cross-section of the second connector 160.

[0041] The distal stop 156a of the second group can be configured to engage the second connector 160 when the delivery wire 152 is retracted, to apply a thrust to the second connector 160 from its distal side. As an example, the distal stop 156a of the second group may include a planar proximal surface configured to engage the planar distal surface of the second connector 160. Other configurations and shapes of the engagement surfaces between the distal stop of the second group and the second connector are possible and will be understood by those skilled in the art. These and other configurations and shapes of the engagement surfaces may be planar, curved, two-dimensional, or three-dimensional, and the scope of this disclosure is not limited to any particular configuration or shape of the engagement surfaces between the distal stop of the second group and the second connector. When the delivery wire 152 is retracted, the distal stop 156a of the second group engages the second connector 160 and applies a thrust to the second connector 160 in a proximal direction. The force applied by the distal stop 156a of the second group can be transmitted to the proximal portion 124 of the tubular implant 120 held by the second connector 160, thereby generating a pulling force on a portion 123 of the tubular implant 120 at the distal end of the proximal portion 124 of the implant 120 (e.g., the portion 123 of the implant between the first connector 158 and the second connector 160). Additionally or alternatively, the proximal stop 156b of the second group can be configured to engage the second connector 160 when the delivery wire 152 is advanced. The proximal stop 156b of the second group may include a distal surface for engaging the second connector, which may be planar or curved, or two-dimensional or three-dimensional in construction and shape. During advancement of the tubular implant 120, the proximal stop 156b of the second group can engage the second connector 160 and apply a thrust to the second connector 160 from the proximal side in a distal direction, as described in more detail below.

[0042] The first set of stops 154a, 154b and the second set of stops 156a, 156b may be constructed from any suitable material, including polymers such as thermoplastics or thermosettings, metals such as stainless steel, platinum, gold, nitinol, other metal alloys, and any combination thereof.

[0043] refer to Figure 2The first connector 158 and the second connector 160 are configured, for example, in terms of size, shape, and / or construction, to contact the collapsed tubular implant 120 and apply radially outward forces thereto hold the implant 120 within the lumen 104 of the tubular member 102. The first connector 158 and the second connector 160 may be constructed of a compressible and expandable material. Alternatively, the first connector 158 or the second connector 160 may be constructed of an incompressible material. As an example, suitable materials for constructing the first connector 158 and / or the second connector 160 include polymeric materials, such as elastomers like silicone, thermosetting plastics, thermoplastic plastics, thermoplastic polyurethanes, and rubber, or non-polymeric materials, such as shape memory metals like nitinol, stainless steel, and cobalt-chromium.

[0044] The shape and / or size of the first connector 158 and the second connector 160 may be configured to provide circumferential surfaces or surface segments conforming to the inner wall surface of the catheter 102, allowing the tubular implant 120 to be clamped or compressed between the inner surface of the catheter 102 and the first connector 158 and the second connector 160, respectively. As an example, the first connector 158 and / or the second connector 160 may have circular, semi-circular, elliptical, or other regular or irregular cross-sectional shapes. In specific embodiments of this disclosure, the first connector 158 and / or the second connector 160 are in the form of a friction pad made of an elastic polymeric material (such as silicone) having a circular cross-sectional shape.

[0045] According to some embodiments of this disclosure, the first connector 158 and the second connector 160 are configured to allow the delivery filament 152 to slide through them. As an example, the first connector 158 and the second connector 160 may be provided with through passages, channels, slots, etc., to allow the elongated delivery filament 152 to slide freely through.

[0046] According to some embodiments of this disclosure, the first coupling 158 and / or the second coupling 160 may comprise a cylindrical tubular body, for example, in the form of a sleeve. The cylindrical tubular body or sleeve may have an outer surface configured to contact the tubular implant 120 and a lumen allowing the delivery wire 152 to pass freely therethrough. The outer and inner diameters of the cylindrical sleeve may be selected such that when the tubular implant 120 and the sleeve are constrained within the lumen 104 of the catheter 102, the frictional force between the compressed sleeve and the delivery wire 152 is sufficient to prevent the sleeve from rotating freely relative to the delivery wire 152. Thus, the implant 120, the distal coupling 158 and the proximal coupling 160, and the delivery wire 152 are rotatably coupled together within the lumen 104 of the catheter 102, thereby allowing features or components on the delivery device 150 to maintain the same position or orientation relative to each other until the first coupling 158 exits the catheter 102. After the first connector 158 has exited the end of the catheter 102, the delivery wire 152 can rotate independently to allow some control over the delivery device 150 during implant deployment. After exiting the catheter 102, the sleeve of the first connector 158 can rotate freely about the delivery wire 152. The linear range of movement of the sleeve of the first connector 158 is limited by a first set of stops 154a, 154b fixed to the delivery wire 152.

[0047] According to an alternative embodiment of this disclosure, the first connector 158 may be secured to the delivery wire 152. This helps prevent relative movement between the implant 120 and the delivery wire 152 within the lumen 104 of the catheter 102, which would otherwise cause twisting of the distal portion 122 of the implant 120 or the implant cap. Once the distal portion 122 of the implant 120 exits the catheter 102, the contact or grip between the distal portion 122 of the implant 120 and the first connector 158 is released, thereby allowing the user to independently twist the delivery wire 152 or independently control the delivery device 150.

[0048] The first connector 158 has a proximal or proximal surface configured to engage the proximal stops 154b of the first set when the delivery wire 152 is pushed to advance the implant 120 constrained in the lumen 104 of the catheter 102. As described above in conjunction with the first sets of stops 154a, 154b, the first connector 158 may include a proximal plane or curved surface, or a two-dimensional or three-dimensional shape or construction configured to engage the proximal stops 154b of the first set when the delivery wire 152 is pushed in a distal direction. Alternatively or additionally, the first connector 158 may include a distal plane or curved surface, or a two-dimensional or three-dimensional shape or construction configured to engage the distal stops 154a of the first set when the delivery wire 152 is retracted in a proximal direction.

[0049] The second connector 160 has a distal side or distal surface configured to engage the distal stop 156a of the second set when the delivery wire 152 is pulled to retract the implant 120 in the lumen 104 of the catheter 102. As described above in conjunction with the second sets of stops 156a, 156b, the second connector 160 may include a distally flat or curved surface, or a two- or three-dimensional shape or construction, configured to engage the distal stop 156a of the second set when the delivery wire 152 is pulled in a proximal direction. Alternatively or additionally, the second connector 160 may include a proximal flat or curved surface, or a two- or three-dimensional shape or construction, configured to engage the proximal stop 156b of the second set when the delivery wire 152 is pushed in a distal direction.

[0050] Figure 3 This is a schematic diagram illustrating the operation of a delivery device 150 according to an embodiment of the present disclosure for advancing a braided support 120 constrained in the lumen 104 of a catheter 102. To advance the support 120, a delivery wire 152 can be pushed in a distal direction, as indicated by arrow A. A first set of stops 154a, 154b and a second set of stops 156a, 156b fixed to the delivery wire 152 also move forward as the delivery wire 152 is pushed in the distal direction. According to an embodiment of the present disclosure, a first coupling 158 disposed between the first set of stops 154a, 154b and a second coupling 160 disposed between the second set of stops 156a, 156b are arranged such that when the delivery wire 152 is pushed in the distal direction to advance the support 120, the proximal stops 154b of the first set engage the first coupling 158, as shown in the diagram. Figure 3As shown. Thus, a forward force is applied to the first connector 158 by the proximal stop 154b of the first set. The gripping between the first connector 158 and the braided support 120 generates a tensile force, as indicated by arrow B, which pulls or stretches a portion 123 of the support 120 proximal to the distal portion 122, for example, the portion 123 between the first connector 158 and the second connector 160. As a result, the diameter of the support portion 123 decreases as the support 120 is pulled or stretched, as indicated by arrow C. The reduction in the support diameter reduces the normal force and / or surface area of ​​the support portion 123 against the inner surface of the catheter 102, thereby reducing the overall frictional force between the support 120 and the catheter 102 (indicated by arrow D). The slight elongation of the support portion 123 also allows the proximal stop 156b of the second set to engage the second connector 160, thereby allowing a forward force to be applied to the second connector 160. Together, the forward force applied by the proximal stop 154b of the first group, the distal tension generated by the first connector 158 on the stent portion 123, and the forward force applied by the proximal stop 156b of the second group enable the stent 120, constrained within the lumen 104 of the catheter 102, to overcome opposing frictions and move forward. The distal tension generated by the first connector 158 on the stent portion 123 reduces the overall resistance during the advancement of the stent 120 constrained within the lumen 104 of the catheter 102.

[0051] Figure 4 This is a schematic diagram illustrating the operation of the delivery device 150 according to an embodiment of the present disclosure for retracting a braided support 120 constrained in the lumen 104 of a catheter 102. To retract the support 120, the delivery wire 152 can be pulled in the proximal direction, as indicated by arrow E. The first set of stops 154a, 154b and the second set of stops 156a, 156b fixed to the delivery wire 152 also move rearward as the delivery wire 152 is pulled in the proximal direction. According to an embodiment of the present disclosure, a first coupling 158 disposed between the first set of stops 154a, 154b and a second coupling 160 disposed between the second set of stops 156a, 156b are arranged such that when the delivery wire 152 is pulled in the proximal direction to retract the support 120, the distal stop 156a of the second set engages the second coupling 160, as shown in the diagram. Figure 4As shown. Thus, a rearward force is applied to the second connector 160 via the distal stop 156a of the second set. The gripping between the second connector 160 and the braided support 120 generates a tensile force, as indicated by arrow F, which pulls or stretches a portion 123 of the support 120 distal to the proximal portion 124, for example, the portion 123 between the first connector 158 and the second connector 160. As a result, the diameter of the support portion 123 decreases as the support 120 is pulled or stretched, as indicated by arrow G. The reduction in the support diameter reduces the normal force and / or surface area of ​​the support portion 123 against the inner surface of the catheter 102, thereby reducing the overall frictional force between the support 120 and the catheter 102 (indicated by arrow H). The slight elongation of the support portion 123 also allows the distal stop 154a of the first set to engage the first connector 158, thereby allowing a rearward force to be applied to the first connector 158. Together, the rearward force applied by the distal stop 156a of the second group, the proximal tension generated by the second connector 160 on the stent portion 123, and the rearward force applied by the distal stop 154a of the first group enable the stent 120 constrained in the lumen 104 of the catheter 102 to overcome opposing frictions and move rearward. The proximal tension generated by the second connector 160 on the stent portion 123 reduces the overall resistance when retracting the stent 120 constrained in the lumen 104 of the catheter 102.

[0052] Therefore, according to embodiments of this disclosure, the positions of the proximal stop 154b of the first group relative to the first connector 158 and the proximal stop 156b of the second group relative to the second connector 160 can be arranged such that, when the delivery wire 152 is pushed in the distal direction to advance the implant 120, the proximal stop 154b of the first group can engage the first connector 158 before the proximal stop 156b of the second group engages the second connector 160. Thus, a distally directed pulling force can be generated by the first connector 158 on the implant portion 123 between the first connector 158 and the second connector 160. This pulling force causes a slight diameter contraction of the implant portion 123, thereby reducing the overall static friction between the implant 120 and the catheter 102. The elongation of the implant portion 123 caused by the pulling force also allows the proximal stop 156b of the second group to engage the second connector 160, thereby allowing a thrust to be applied to the second connector 160 to advance the implant 120.

[0053] Conversely, according to embodiments of this disclosure, the positions of the first set of distal stops 154a relative to the first connector 158 and the second set of distal stops 156a relative to the second connector 160 can be arranged such that, when the delivery wire 152 is pulled in the proximal direction to retract the implant 120, the second set of distal stops 156a can engage the second connector 160 before the first set of distal stops 154a engages the first connector 158. Therefore, a proximal pulling force can be generated by the second connector 160 on the implant portion 123 between the first connector 158 and the second connector 160. The pulling force causes a slight diameter contraction of the implant portion 123 between the first connector 158 and the second connector 160, thereby reducing the overall static friction between the implant 120 and the catheter 102. The elongation of the implant 120 caused by the tension also allows the distal stop 154a of the first group to engage the first connector 158, thereby allowing force to be applied to the first connector 158 to retract the implant 120.

[0054] It should be noted that, although combined with, for example Figures 2 to 4 The two couplings and two sets of stops shown illustrate various embodiments, but the delivery device according to embodiments of this disclosure may include fewer or more than two couplings and fewer or more than two sets of stops. Figure 5 An intravascular system 200 according to an alternative embodiment of the present disclosure is depicted, which includes a delivery device 250 having a coupling and a set of stops.

[0055] like Figure 5 As shown, an exemplary endovascular system 200 includes an elongated tubular member or catheter 202 having a lumen 204, a tubular implant 220 disposed within the lumen 204 of the catheter 202, and a delivery device 250 operable to deliver the tubular implant 220 to a target site. The delivery device 250 may generate a distally pulling force on the tubular implant 220 to aid in the advancement of the implant 220.

[0056] The catheter 202 and the tubular implant 220 can be combined with the above. Figures 1 to 4 The described catheter 102 and tubular implant 120 are identical or similar. In contrast, Figure 5The delivery device 250 shown includes a delivery wire 252, a set of stops 254a, 254b, a connecting feature or connector 258, and a buffer feature or bumper 260. The connector 258 is disposed between the stops 254a, 254b and configured to contact the distal portion 222 of the tubular implant 220 and apply a radially outward force to hold the tubular implant 220 within the lumen 204 of the catheter 202. The bumper 260 is disposed adjacent to the proximal portion 224 of the implant 220 and configured to apply a forward force to the implant 220 at the proximal portion 224.

[0057] refer to Figure 5 A set of stops 254a, 254b may include a stop 254a at the distal side of the connector 258 and a stop 254b at the proximal side of the connector 258. The distal stop 254a and the proximal stop 254b may be secured to the delivery wire 252 and thus may be advanced, retracted, and rotated together with the delivery wire 252. The delivery wire 252, the distal stop 254a, the proximal stop 254b, and the connector 258 may be combined as described above. Figures 2 to 4 The delivery wire 152, the first set of stops 154a, 154b, and the first connector 158 described are identical or similar. A buffer 260 adjacent to the proximal portion 224 of the tubular implant 220 can be coupled or secured to the delivery wire 252 in any suitable manner. The buffer 260 can be constructed of any suitable material, such as metal, metal alloy, polymer, or any combination thereof. The buffer 260 can be in any suitable form or construction, such as a tube, cone, cylinder, ellipsoid, etc.

[0058] To advance the tubular implant 220, the delivery wire 252 can be pushed in a distal direction. Stops 254a and 254b attached to the delivery wire 252 also move forward as the delivery wire 252 is pushed in the distal direction. According to an embodiment of this disclosure, the connector 258, stops 254a and 254b, and proximal buffer 260 are arranged such that when the delivery wire 252 is pushed forward, the proximal stop 254b engages the connector 258. Thus, a forward force is applied to the connector 258 through the proximal stop 254b. The grip between the connector 258 and the implant 220 slightly pulls or stretches a portion 223 of the implant 220 proximal to the distal portion 222 of the implant 220. As a result, the diameter of the implant portion 223 decreases as the implant 220 is pulled or stretched. The reduction in implant diameter decreases the normal force and / or surface area of ​​implant portion 223 against the inner surface of catheter 202, thereby reducing the overall friction between implant 220 and catheter 202. The slight elongation of implant portion 223 also allows buffer 260 to engage the proximal portion 224 of implant 220, thereby allowing a forward force to be applied to the proximal portion 224 of implant 220. Together, the forward force applied by proximal stop 254b, the distal tension generated by connector 258 on implant portion 223, and the forward force applied by buffer 260 enable implant 220, constrained within lumen 204 of catheter 202, to overcome opposing frictions and move forward. The distal tension generated by connector 258 on implant portion 223 reduces the overall resistance to advancing implant 220 constrained within lumen 204 of catheter 202. To retract the implant 220, the delivery wire 252 can be pulled in the proximal direction. The distal stop 254a, which is attached to the delivery wire 252, can apply a rearward force to the connector 258 to help retract the implant 220 into the catheter 202.

[0059] Figure 6 An exemplary application of the endovascular system 200 of this disclosure is illustrated for treating an aneurysm 110 in a cerebrovascular system 112. In use, a tubular implant 220 (such as a braided flow-directing stent) can be loaded onto a delivery device 250 of this disclosure within a microcatheter 202. The flow-directing stent 220 and delivery device 250 within the microcatheter 202 can be introduced to the target site via an access, for example, in the femoral artery or groin region of the patient, using a guide sheath or guiding catheter (not shown). The endovascular system 200 can be guided to the target site via a guidewire (not shown). The guidewire is visible via fluoroscopic examination, allowing the endovascular system to be reliably advanced to the target site over the guidewire.

[0060] Once the target area has been reached, the guidewire can be withdrawn. Then, the method described above can be used in combination. Figures 2 to 5 The delivery device 250 of this disclosure delivers a flow-directing stent 220. The physician can advance and withdraw the stent 220 multiple times before full deployment to achieve the desired position of the stent 220 relative to the neck of the aneurysm 110. Once the stent 220 is satisfactorily positioned, the physician can push the delivery wire 252 distally, allowing the stent 220 to completely exit the microcatheter 202 and expand at the target site in a deployed configuration. The delivery device 250 can then be withdrawn back into the microcatheter 202 and removed from the patient.

[0061] Now for reference Figure 7 This document describes a method 700 according to embodiments of the present disclosure. Method 700 can be used to deliver a tubular implant, such as a braided tubular stent, to the cerebrovascular system or other treatment sites within a patient. Method 700 can utilize a combination of... Figures 1 to 5 The intravascular system 100, 200 or any other suitable system described herein shall be used to perform this action.

[0062] Method 700 may begin by introducing an endovascular system into a treatment site within a patient, such as the cerebrovascular system. The endovascular system may include: an elongated tubular member, such as a catheter or sheath; a tubular implant disposed or constrained within the lumen of the catheter; and a delivery device operable to advance the tubular implant relative to the catheter for deployment and / or retract the tubular implant for repositioning.

[0063] At step 702, a translational force in the distal direction is applied to the distal portion of the tubular implant. This translational force can be applied by the delivery device using a connecting feature or connector (distal connector) that contacts the distal portion of the tubular implant in the catheter and applies a radially outward force to hold the implant within the catheter lumen. A stop fixed to the delivery wire can be used to push the distal connector from its proximal side. Thus, the distal connector can transmit the translational force in the distal direction to the distal portion of the implant. Due to the translational force applied to the distal portion of the implant, a portion of the implant proximal to the distal portion is pulled or stretched, thereby reducing the diameter of that portion. This reduction in implant diameter reduces the normal force and / or surface area of ​​the implant portion against the inner surface of the catheter, thereby reducing the overall friction between the implant and the catheter.

[0064] At step 704, a distal translational force is applied to the proximal portion of the tubular implant. This distal translational force can be applied by the delivery device to the proximal portion of the implant using a connecting feature or connector (proximal connector), which contacts the proximal portion of the tubular implant in the catheter and applies a radially outward force to hold the implant within the lumen of the catheter. A stop fixed to the delivery wire can be used to push the proximal connector from its proximal side. Thus, the proximal connector can transmit the distal translational force to the proximal portion of the implant. Together, the translational force applied to the distal connector by the stop, the distal tension generated on the implant portion by the distal connector, and the translational force applied to the proximal connector by the stop enable the implant, constrained within the lumen of the catheter, to overcome opposing friction and move forward. The distal tension generated by the distal connector on the implant portion reduces the overall resistance when advancing the implant, which is constrained within the lumen of the catheter.

[0065] According to an embodiment of this disclosure, a translational force in the distal direction is applied to the distal portion of the tubular implant (step 702) before applying a translational force in the distal direction to the proximal portion of the tubular implant (step 704). This can be achieved by arranging the stop fixed to the delivery wire relative to the distal and proximal connectors such that when the delivery wire is pushed in the distal direction, the stop engages the distal connector first before engaging the proximal connector.

[0066] According to embodiments of this disclosure, the method may further include retracting the implant in a proximal direction. The implant may be retracted or reinserted into the cannula as needed, as determined by a physician, to reposition the implant before it is fully released. Retraction or reinsertion of the implant into the cannula may include steps 706 and 708.

[0067] At step 706, a translational force in the proximal direction is applied to the proximal portion of the tubular implant. This translational force can be applied from the delivery device using a proximal connector that contacts the proximal portion of the tubular implant in the catheter and applies a radially outward force to hold the implant within the catheter lumen. A stop attached to the delivery wire can be used to push the proximal connector from its distal side. Thus, the proximal connector can transmit the translational force in the proximal direction to the proximal portion of the implant. Due to the translational force applied to the proximal portion of the implant, a portion of the implant distal to the proximal portion is pulled or stretched, thereby reducing the diameter of that portion. This reduction in implant diameter reduces the normal force and / or surface area of ​​the implant portion against the inner surface of the catheter, thereby reducing the overall friction between the implant and the catheter.

[0068] At step 708, a translational force in the proximal direction can be applied to the distal portion of the tubular implant. This translational force can be applied from the delivery device to the distal portion of the implant using a distal connector that contacts the distal portion of the tubular implant in the catheter and applies a radially outward force to hold the implant within the lumen of the catheter. A stop fixed to the delivery wire can be used to push the distal connector from its distal side. Thus, the distal connector can transmit the translational force in the proximal direction to the distal portion of the implant. Together, the translational force applied to the proximal connector by the stop, the proximal tension generated on the implant portion by the proximal connector, and the translational force applied to the distal connector by the stop enable the implant, constrained within the lumen of the catheter, to overcome opposing friction and move backward. The proximal tension generated by the proximal connector on the implant portion reduces the overall resistance when retracting or re-entering the implant, which is confined within the lumen of the catheter.

[0069] According to an embodiment of this disclosure, a translational force in the proximal direction is applied to the proximal portion of the tubular implant (step 706) before applying a translational force in the proximal direction to the distal portion of the tubular implant (step 708). This can be achieved by arranging the stop fixed to the delivery wire relative to the proximal and distal connectors such that when the delivery wire is pulled in the proximal direction, the stop engages the proximal connector first before engaging the distal connector.

[0070] Various embodiments of endovascular systems including delivery devices have been described. Advantageously, the delivery device of this disclosure includes one or more connecting features for contacting and / or gripping a tubular implant constrained within the lumen of a catheter, which can generate tension on the implant in both the advance and retraction directions, thereby reducing the overall delivery force. This is particularly advantageous in the endovascular treatment of cerebrovascular diseases such as aneurysms. Flow-directing stents are commonly used to treat cerebral aneurysms. However, delivering flow-directing stents within the brain anatomy, especially in small distal cerebral vessels, presents challenges. For the delivery of flow-directing stents to cerebral vessels, microcatheters with small diameters are required. For example, to reach more distant brain anatomy structures, microcatheters used to deliver flow-directing stents can have inner diameters as small as 0.027", 0.021", or 0.017". Flow-directing stents must also be designed for deliverability through the microcatheter and distal cerebral vessels. To fit within the microcatheter, the size of the flow-directing stent must be reduced, which can affect the achievable pore density. The connection features of this disclosure advantageously reduce the overall delivery force, thereby improving the deliverability of the stent via the microcatheter. It also allows flow-directing stents to be constructed without compromising on diameter, radial force, and pore density. To increase the radial force and pore density of the stent, in the stent... More filaments or larger filament diameters are typically used in stent designs. However, in more distal anatomy, smaller microcatheters are needed to navigate, approach, or engage within smaller vessels, thus limiting the size of the lumen through which stents can be delivered. Smaller microcatheters with more compact lumens require higher delivery forces to deliver the stent to distal anatomy. Therefore, to reduce delivery forces, filament counts or sizes are often reduced in stent designs to decrease the stent profile within the microcatheter lumen, which necessitates concessions in stent radial force and pore density. The connection features of this disclosure can advantageously reduce delivery forces in delivery systems without requiring significant concessions in filament counts and sizes in stent design.

[0071] Another advantage of this disclosure is that, in the event that the proximal connector loses contact with the implant during re-entry into the cannula, the distal connector can serve as a backup connector feature. In rare cases, the braided stent may lose contact with its proximal connector during re-entry into the cannula. Using the distal connector feature, the delivery system can be further withdrawn to allow the distal connector to re-engage with the remaining segment of the implant restrained in the catheter and regain the ability to move the implant. Another advantage of having a distal connector feature is improved distal opening capability of the implant. For braided stents with exposed wire ends delivered via an empty catheter, the distal end of the stent needs to be protected from friction or damage by the covering feature, which could hinder proper stent opening. The relatively large profile of the distal connector and its proximity to the distal portion of the restrained device can help ensure that the braided wire is more biased for full expansion.

[0072] Now for reference Figures 8 to 9 The endovascular system 300 according to an alternative embodiment of the present disclosure is now described. In a broad overview, the exemplary endovascular system 300 includes a catheter 302, a tubular implant 320, and a delivery device 350 operable to deliver and deploy the tubular implant 320. The delivery device 350 includes a protective sheath 380 that wraps around at least an end portion of the tubular implant 320 to protect the implant from damage during delivery and deployment.

[0073] In conventional stent delivery, if the stent remains restrained by the protective sheath after withdrawal from the delivery catheter, thus preventing stent opening or expansion, the stent is typically re-entered or withdrawn from the catheter by relative movement of the catheter and the delivery wire. However, re-entry of a tubular stent into the catheter can be difficult, especially in tortuous anatomy such as that of cerebral vessels. Another problem with conventional delivery is that during stent deployment, the delivery wire may become stuck at a narrow bend in the vessel or may enter a perforator, i.e., a small artery branching off from the aorta. As a result, the delivery wire cannot be advanced further, hindering stent deployment. If this occurs, the physician can only re-enter and redeploy the stent, hoping the delivery wire tip will take a different orientation and that such problems will not occur during deployment. The inability to remove the protective sheath even after re-entry is common in conventional stent delivery, occurring more than 25% of the time. According to embodiments of this disclosure, the endovascular system allows for relative rotational movement of the protective sheath and the tubular implant, thereby facilitating implant release and deployment. The delivery device disclosed herein includes a twistable delivery wire with a band-shaped end segment to help physicians navigate through tortuous geometric areas and avoid the risk of perforating the vessel wall or getting stuck in arteries branching off from the aorta.

[0074] refer to Figures 8 to 9 An example endovascular system 300 according to an embodiment of the present disclosure includes a catheter 302 having a lumen 304, a tubular implant 320, and a delivery device 350 operable to deliver the tubular implant 320 through the catheter 302. The tubular implant 320 has a collapsed state for placement within the lumen 304 of the catheter 302 and an expanded state when not constrained by the catheter 302. The delivery device 350 generally includes: an elongated delivery wire 352 having a proximal segment 352a and a distal segment 352b; a set or more sets of stops 354a / 354b, 356a / 356b, fixedly attached to the distal segment 352b of the delivery wire 352; and one or more couplings 358, 360 respectively disposed on the set or more sets of stops 354a / 354b, 356a / 356b. Figure 9Between; and a protective sheath 380. One or more connectors 358, 360 are configured to contact a portion of the tubular implant 320 and apply a radially outward force thereto to hold the implant within the lumen 304 of the catheter 302. One or more connectors 358, 360 are provided with through openings allowing the delivery wire 352 to pass through. The protective sheath 380 includes a first end portion 382 fixedly coupled to a distal segment 352b of the delivery wire 352 and a second end portion 384 enclosing at least a end portion of the tubular implant 320 within the lumen 304 of the catheter 302. As will be described in more detail below, one or more connectors 358, 360 are configured to allow the distal segment 352b of the delivery wire 352 to slide or rotate longitudinally relative to one or more connectors 358, 360. The longitudinal movement of the delivery wire 352 within the lumen 304 of the catheter 302 allows one or more sets of stops 354a / 354b, 356a / 356b to engage one or more connectors 358, 360 for advancing or retracting the tubular implant 320. Rotation of the delivery wire 352 relative to one or more connectors 358, 360 allows the protective sheath 380 to be withdrawn from the end portion of the tubular implant 320 upon exiting the lumen 304 of the catheter 302, thereby facilitating the opening or expansion of the tubular implant 320.

[0075] refer to Figures 8 to 9The catheter 302 can be any suitable tubular component in the form of a sheath, catheter, microcatheter, or other suitable tubular form. The catheter 302 may include a proximal portion 306, a distal portion 308, and a lumen 304 extending between the proximal and distal portions 308. When the endovascular system is in use, the proximal portion 306 may remain outside the patient's body and be accessible to the user or physician. The size and dimensions of the distal portion 308 may be configured to reach remote locations within the patient's vascular system, such as in cerebral vessels adjacent to aneurysms, bifurcation vessels, occlusions in vessels, etc. The lumen 304 of the catheter 302 may be configured to accommodate a tubular implant 320 and a delivery device 350, the delivery device 350 including stops 354, 356 and connectors 358, 360. Although not explicitly shown, the catheter 302 may include one or more segments or regions, each segment or region may have different constructions and / or characteristics. For example, the distal portion 308 of catheter 302 may include a flexible segment or region including a coil that provides appropriate bending or deflection. The flexible distal portion allows the endovascular system to navigate more easily through tortuous areas of the vascular system to a remote location within the patient. The proximal portion 306 may be constructed of a rigid material (e.g., a rigid metal hypotube) to provide structural stability and sufficient maneuverability. Typically, catheter 302 or a segment of catheter 302 may be constructed of a suitable biocompatible polymer, metal, or a combination thereof. The outer diameter of the distal portion 308 of catheter 302 may be smaller than the outer diameter of the proximal portion 306 to reduce the profile of the distal portion and facilitate navigation through tortuous vascular systems. Although not shown, catheter 302 may include one or more markers that can be visualized, for example, via X-ray fluoroscopy, to assist the physician in manipulating the endovascular system. The inner and outer diameters of catheter 302 at the distal portion 308 may be appropriately selected based on the application. For example, in the application of treating cerebral aneurysms, the catheter or microcatheter 302 may have an inner diameter ranging from 0.0165 inches to 0.040 inches to deliver a blood flow guiding stent of appropriate size to a target site in the brain anatomy or distal cerebral blood vessels.

[0076] refer to Figures 8 to 9The tubular implant 320 can be any suitable implant adapted to the delivery device of this disclosure. For example, the tubular implant 320 can be an embolization device, such as a stent, a flow-directing stent, or an intracapsular device for treating cerebral aneurysms. In describing various embodiments of this disclosure, the term "tubular implant" can be used interchangeably with the term "stent." The tubular implant 320 can be expandable, having a collapsed state when compressed or restrained within the lumen of a catheter, and an expanded state when withdrawn from the catheter unrestrained or deployed at a treatment site. As shown, the tubular implant 320 includes a distal portion 322, a proximal portion 324, and an intermediate portion 323 between the distal portion 322 and the proximal portion 324.

[0077] The tubular implant 320 may include a braided structure or a patterned cut tube structure. The braided structure or patterned cut tube structure may be a closed-unit design, in which repeating loop structures are connected at all strut joints. The braided structure or patterned cut tube structure may also be an open-unit scaffold design, in which some joints between the repeating loop structures are removed.

[0078] An exemplary tubular implant 320 includes a braided scaffold constructed from multiple wires or filaments. The filaments can be braided, woven, or interlaced in a suitable pattern. For example, the filaments can extend clockwise in a helical or spiral configuration, and can extend counterclockwise in a helical or spiral configuration to form multiple intersecting segments and multiple units defining a radially expandable body. The braided scaffold can be a closed-unit design. The filaments constructing the braided scaffold can be metallic or polymeric. The filaments can be radiopaque or non-radiopaque, or at least one or more of the filaments constituting the scaffold can be radiopaque. Depending on the application, the braided scaffold can include about 40 to about 96 filaments. The filaments can have a diameter ranging from 0.0008 to 0.0030 inches. The filaments can have shape memory properties and / or can be heat-set to form a self-expanding scaffold. In the expanded state, depending on the application, the braided scaffold can have a maximum diameter ranging from 1.0 mm to 10 mm. For the treatment of cerebral aneurysms, braided stents can be constructed with flow-directing devices having pore size and / or density suitable for interrupting or redirecting blood flow near the neck of the aneurysm, thereby causing occlusion of the aneurysm while allowing blood to flow in the carrier vessel and branch vessels.

[0079] According to embodiments of this disclosure, at least some of the filaments forming the tubular implant 320 are composite wires, such as drawn-filled tubing (DFT) wires. The composite wire (e.g., a DFT wire) includes a core of a first material and a shell of a second material different from the first material.

[0080] Suitable materials for the core of composite wires can be materials with corresponding rigidity and rupture resistance. Example materials for the core of composite wires include, but are not limited to, nickel-cobalt alloys (e.g., MP35N), stainless steel, cobalt-chromium alloys, etc. A rigid, rupture-resistant core material can provide greater radial force against the inner surface of the delivery catheter when the tubular implant is placed within the lumen of the delivery catheter. According to alternative embodiments of this disclosure, the core of the composite wire can be a radiopaque material visible via X-ray fluoroscopy, including but not limited to tungsten, platinum, iridium, gold, tantalum, or any alloys thereof, such as platinum-iridium alloys, platinum-tungsten alloys, etc.

[0081] Suitable materials for the sheath of the composite wire can be materials with elastic or hyperelastic properties. Example materials for the sheath of the composite wire include, but are not limited to, nickel-titanium alloys (e.g., nitinol). Elastic or hyperelastic sheath materials can provide greater flexibility to the tubular implant 320, making it easier to use. According to embodiments of this disclosure, the sheath of the composite wire includes a cobalt-chromium alloy, which can provide structural strength to the DFT wire, resulting in a braided support with higher radial forces.

[0082] According to embodiments of this disclosure, the fill percentage of the composite wire core can be selected to provide a desired balance between the flexibility and radial strength of the tubular implant 320. As used herein, the phrase "fill percentage" refers to the proportion of the cross-sectional area of ​​the composite wire occupied by the core material (the filler material) relative to the total cross-sectional area of ​​the composite wire. According to embodiments of this disclosure, the composite wire includes a fill percentage of core material ranging from about 5% to 35%, or 5% to 30%, or 10% to 30%. In some embodiments, the composite wire includes a fill percentage of core material not exceeding 30%.

[0083] According to embodiments of this disclosure, the tubular implant 320 comprises a braided scaffold constructed of multiple composite wires comprising an inner core of a nickel-cobalt alloy (e.g., MP35N) and an outer shell of a nickel-titanium alloy (e.g., Nitinol). The composite wires comprise a fill percentage ranging from about 5% to 30% of the inner core material.

[0084] Advantageously, the tubular implant 320 constructed from composite filaments according to embodiments of the present disclosure can both maintain the hyperelasticity of implants provided by, for example, pure nitinol filaments, and achieve the higher radial force and radial resistance provided by, for example, MP35N. For example, the braided stent 320 constructed from MP35N-nitinol composite filaments or DFT filaments of the present disclosure can achieve a fusion of the high radial force, rigidity, and rupture resistance provided by cobalt-chromium implants with the hyperelasticity and ease of use provided by nitinol implants, thereby resolving the dilemma experienced in the prior art of having to choose between cobalt-chromium implants and nitinol stents. Another advantage is that it allows the use of smaller diameter composite filaments to achieve the same radial force provided by, for example, larger diameter pure nitinol filaments, which in turn allows for the use of smaller diameter delivery catheters for implant delivery. This is highly desirable in areas such as neurovascular systems.

[0085] refer to Figures 8 to 9 The delivery device 350 includes: an elongated delivery wire 352; one or more sets of stops 354a / 354b, 356a / 356b, which are fixedly attached to the delivery wire 352; one or more couplings 358, 360, which are respectively disposed between one or more sets of stops 354a / 354b, 356a / 356b; and a protective cover 380. Figure 9 The illustrated example delivery device 350 includes: a first set of stops 354a, 354b fixed to the delivery wire 352; a first connecting member 358 disposed between the first set of stops 354a, 354b; a second set of stops 356a, 356b fixed to the delivery wire 352; and a second connecting member 360 disposed between the second set of stops 356a, 356b. It should be noted that the delivery device 350 may include fewer than two sets or more than two sets of stops and fewer than two or more connecting members.

[0086] refer to Figures 8 to 9The elongated delivery wire 352 has a proximal segment 352a, a distal segment 352b, and a length extending between the proximal segment 352a and the distal segment 352b. The proximal segment 352a and the distal segment 352b of the delivery wire 352 may have different profiles, constructions, and / or comprise different materials. For example, the proximal segment 352a may be constructed from a stiffer material (e.g., a rigid metal hypotube) and / or have a larger diameter to provide structural stability and sufficient maneuverability. The distal segment 352b of the delivery wire may be more flexible or have a reduced profile to provide appropriate bending or deflection for navigation through tortuous vascular systems or to reach distant small vessels. The proximal segment 352a of the delivery wire 352 may remain outside the patient's body and is accessible to the physician when the delivery device is used. During operation, the proximal segment 352a, which can be coupled to a handle, can be controlled by the user. For example, the proximal segment 352a can be pushed, pulled, and / or twisted to advance or retract the tubular implant 320 through the catheter 302, and / or to remove the protective sheath 380 from the end portion of the tubular implant 320 after exiting the catheter 302, as described in more detail below. One or more sets of stops 354a / 354b, 356a / 356b can be securely attached to the distal segment 352b of the delivery wire 352, and thus pushed, pulled, and / or rotated with the delivery wire 352. The delivery wire 352 may include one or more markers, such as marker 353 located on the distal segment of the delivery wire 352, to assist a physician in manipulating the delivery device 350 via X-ray fluoroscopy. The delivery wire 352 may be constructed of a suitable metal, such as stainless steel, nickel, titanium, nickel-titanium alloy, metal alloy, biocompatible polymer, shape memory polymer, thiourea tube, or any combination thereof.

[0087] refer to Figures 8 to 9 The delivery wire 352 may include a band-shaped distal segment 352c. For example, the distal segment 352c of the delivery wire 352 may be heat-shaped or processed to have an angled, curved, or other shaped configuration, and retain this band-shaped configuration. For example, the angled distal segment 352c may extend distally and may be oriented to bend or be angled from the longitudinal axis of the delivery wire 352. The angled distal segment 352c may form an angle ranging from 15 to 90 degrees with the longitudinal axis of the delivery wire 352. One advantage of the angled distal segment is that when the delivery wire 352 is twisted at the proximal segment 352a, the orientation of the band-shaped distal segment 352c changes, thereby allowing the physician to navigate through tortuous geometric areas and avoid entering branch arteries and / or avoiding the risk of perforation of the vessel wall.

[0088] refer to Figures 8 to 9One or more sets of stops 354a / 354b, 356a / 356b can be fixed to the delivery wire 352. For example, the first set of stops 354a, 354b and the second set of stops 356a, 356b can be fixed to the distal section 352b of the delivery wire 352. The positions of the first set of stops 354a, 354b and the second set of stops 356a, 356b can be selected such that the first connector 358 disposed between the first set of stops 354a, 354b can be positioned adjacent to the distal portion 322 of the tubular implant 320 and thereby apply a radially outward force to the tubular implant 320 to hold the implant in the lumen 304 of the catheter 302, and the second connector 360 disposed between the second set of stops 356a, 356b can be positioned adjacent to the proximal portion 324 of the tubular implant 320 and thereby apply a radially outward force to the tubular implant 320 to hold the implant 320 in the lumen 304 of the catheter 302. As will be described in more detail below, the arrangement of the first set of stops 354a, 354b and the first connector 358 allows the first connector 358, which grips the distal portion 322 of the tubular implant 320, to generate a distally pulling force on the implant portion 323 proximal to the distal portion 322 of the implant 320, thus facilitating the advancement of the implant 320 from the catheter 302. The arrangement of the second set of stops 356a, 356b and the second connector 360 allows the second connector 360, which grips the proximal portion 324 of the tubular implant 320, to generate a proximal pulling force on the implant portion 323 distal to the proximal portion 324 of the implant 320, thus facilitating the retraction of the implant 320 into the catheter 302.

[0089] exist Figure 9 In the example shown, the first set of stops 354a, 354b includes a stop 354a distal to the first connector 358 and a stop 354b proximal to the first connector 358. The distal and proximal stops 354a and 354b of the first set can be fixedly attached to the distal segment 352b of the delivery wire 352 and thus advance, retract, and / or rotate with the delivery wire 352. The size of the first set of stops 354a, 354b can be configured such that they do not directly contact the tubular implant 320 in the lumen 304 of the catheter 302, or do not generate sufficient frictional force to advance or retract the implant 320 constrained in the lumen 304 of the catheter 302 via direct contact with the tubular implant 320. In some embodiments, the size of the first set of stops 354a, 354b is configured such that their cross-section is smaller than the cross-section of the first connector 358.

[0090] The proximal stop 354b of the first group can be configured to engage the first connector 358 when the delivery wire 352 is advanced, to apply a thrust to the first connector 358 from its proximal side. For example, the proximal stop 354b of the first group may include a planar distal surface configured to engage with a planar proximal surface of the first connector. Other configurations and shapes of the engagement surfaces between the proximal stop 354b of the first group and the first connector 358 are possible and will be understood by those skilled in the art. These and other configurations and shapes of the engagement surfaces may be planar or curved, two-dimensional or three-dimensional, and the scope of this disclosure is not limited to any particular configuration and shape of the engagement surfaces between the proximal stop of the first group and the first connector. When the delivery wire 352 is advanced, the proximal stop 354b of the first group engages the first connector 358 and applies a thrust to the first connector 358 in a distal direction. The thrust applied by the proximal stop 354b of the first group can be transmitted to the distal portion 322 of the tubular implant 320 held by the first connector 358, thereby generating thrust on the portion 323 of the implant 320 proximal to the distal portion 322 of the tubular implant 320 (e.g., the portion of the implant between the first connector 358 and the second connector 360). Additionally or optionally, the distal stop 354a of the first group can be configured to engage the first connector 358 when the delivery wire 352 is retracted. The distal stop 354a of the first group may include a planar or curved, or configured and shaped as a two- or three-dimensional proximal surface for engaging the first connector 358. When the tubular implant 320 is retracted or re-entered, the distal stop 354a of the first group can engage the first connector 358 and apply thrust to the first connector 358 from its distal side in a proximal direction.

[0091] refer to Figure 9 The second set of stops 356a and 356b includes a stop 356a distal to the second connector 360 and a stop 356b proximal to the second connector 360. The distal and proximal stops 356a and 356b of the second set can be fixedly attached to the delivery wire 352 and are thus advanced, retracted, and / or rotated with the delivery wire 352. The stops 356a and 356b of the second set can be sized such that they do not directly contact the tubular implant 320 in the lumen 304 of the catheter 302, or do not generate sufficient frictional force to advance or retract the implant 320 constrained in the lumen 304 of the catheter 302 via direct contact with the tubular implant 320. In some embodiments, the stops 356a and 356b of the second set are sized such that their cross-section is smaller than the cross-section of the second connector 360.

[0092] The distal stop 356a of the second group can be configured to engage the second connector 360 when the delivery wire 352 is retracted, to apply a thrust to the second connector 360 from its distal side. For example, the distal stop 356a of the second group may include a planar proximal surface configured to engage with a planar distal surface of the second connector 360. Other configurations and shapes of the engagement surfaces between the distal stop 356a of the second group and the second connector 360 are possible and will be understood by those skilled in the art. These and other configurations and shapes of the engagement surfaces may be planar or curved, two-dimensional or three-dimensional, and the scope of this disclosure is not limited to any particular configuration and shape of the engagement surfaces between the distal stop of the second group and the second connector. When the delivery wire 352 is retracted, the distal stop 356a of the second group engages the second connector 360 and applies a thrust to the second connector 360 in a proximal direction. The thrust applied by the distal stop 356a of the second group can be transmitted to the proximal portion 324 of the tubular implant 320 held by the second connector 360, thereby generating thrust on the portion 323 of the tubular implant 320 distal to the proximal portion 324 of the implant (e.g., the portion of the implant between the first connector 358 and the second connector 360). Additionally or optionally, the proximal stop 356b of the second group can be configured to engage the second connector 360 when the delivery wire 352 is advanced. The proximal stop 356b of the second group may include a planar or curved, or configured and shaped as two-dimensional or three-dimensional, distal surface for engaging the second connector. During advancement of the tubular implant 320, the proximal stop 356b of the second group can engage the second connector 360 and apply thrust to the second connector 360 from its proximal side in a distal direction.

[0093] The first set of stoppers 354a, 354b and the second set of stoppers 356a, 356b may be constructed from any suitable material, including polymers such as thermoplastics or thermosettings, metals such as stainless steel, platinum, gold, nickel-titanium or other metal alloys, and any combination thereof.

[0094] refer to Figure 9The first connector 358 and the second connector 360 are configured, for example, to be sized, shaped, and / or constructed to contact the collapsed tubular implant 320 and apply a radially outward force thereto to hold the implant 320 within the lumen 304 of the catheter 302. The first connector 358 and the second connector 360 may be constructed of compressible or expandable materials. Alternatively, the first connector 358 and / or the second connector 360 may be constructed of incompressible materials. As an example, suitable materials for constructing the first connector 358 and / or the second connector 360 include polymeric materials, such as elastomers like silicone, thermosetting plastics, thermoplastic plastics, thermoplastic polyurethanes, and rubber, or non-polymeric materials, such as shape memory metals like nitinol, stainless steel, and cobalt-chromium.

[0095] The shape and / or size of the first connector 358 and the second connector 360 may be configured to provide circumferential surfaces or surface segments adapted to the inner wall surface of the catheter 302, allowing the tubular implant 320 to be clamped or compressed between the inner surface of the catheter 302 and the first connector 358 and the second connector 360, respectively. As an example, the first connector 358 and / or the second connector 360 may have a circular, semi-circular, elliptical, or other regular or irregular cross-sectional shape. In a specific embodiment of this disclosure, the first connector 358 and / or the second connector 360 are in the form of a friction pad made of an elastic polymeric material (such as silicone) having a circular cross-sectional shape.

[0096] According to some embodiments of this disclosure, the first connector 358 and the second connector 360 are configured to allow a delivery wire 352, for example, a distal segment 352b of the delivery wire 352, to pass through it. As an example, the first connector 358 and the second connector 360 may be provided with through openings, channels, slots, etc., to allow the elongated delivery wire 352 to rotate relative to the first connector 358 and the second connector 360 within the lumen 304 of the conduit 302.

[0097] According to some embodiments of the present disclosure, the first connector 358 and / or the second connector 360 may include a cylindrical tubular body, for example, in the form of a bushing. The cylindrical tubular body or bushing 358, 360 may have an outer surface configured to contact the tubular implant 320 and a lumen allowing the delivery wire 352 to pass through it. According to embodiments of the present disclosure, the outer and inner diameters of the cylindrical bushings 358, 360 and the through openings therein may be selected such that the delivery wire 352 can still be twisted and rotated relative to the cylindrical bushings 358, 360 when the tubular implant 320 and the bushings 358, 360 are constrained within the lumen 304 of the catheter 302. In some embodiments, the outer and inner diameters of the cylindrical bushings 358, 360 and the through opening therein can be selected such that when the tubular implant 320 and the bushings are constrained within the lumen 304 of the catheter 302, the frictional force between the compressed bushings 358, 360 and the delivery wire 352 is sufficient to prevent the bushings 358, 360 from rotating freely relative to the delivery wire 352. After the first connector 358 has exited the end of the catheter 302, the delivery wire 352 can be independently twisted or rotated.

[0098] refer to Figures 8 to 9 The delivery device 350 may include a protective sheath 380. The protective sheath 380 may protect the tubular implant 320, assist in the delivery and deployment of the tubular implant 320, and / or perform other functions. As discussed above, a braided stent may include multiple filaments or strands. Friction or abrasion of the filaments or strands against the inner wall of the catheter can cause wear, bending, breakage, or other mechanical damage to the stent filaments. The risk of damage to the braided stent increases when the stent is subjected to forces through a tortuous, turning, or bent path. Damaged filaments can compromise the integrity of the stent, hinder its opening or expansion, and impede proper fit or contact between the expanded stent and the vessel wall. Furthermore, the ends of the stent filaments may pierce the liner of the catheter, for example, by scooping out small polymer particles and releasing them into the patient. For this and other reasons, a protective sheath for tubular implants would be highly desirable.

[0099] According to embodiments of this disclosure, the protective sheath 380 may be made of a polymeric material, such as polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyurethane, polyethylene, or other biocompatible polymers. PTFE or ePTFE is known for its flexibility, biocompatibility, and smooth surface. Alternatively, the protective sheath 380 may include a thin metal mesh, such as stainless steel or nitinol mesh, to provide additional mechanical strength and kink resistance.

[0100] refer to Figures 8 to 9The protective sheath 380 may include a first end portion 382 and a second end portion 384. The first end portion 382 of the protective sheath 380 may be fixedly coupled to a distal segment 352b of the delivery wire 352, or fixedly coupled to a radiopaque marker 353, which in turn is fixed to the distal segment 352b of the delivery wire 352. The second end portion 384 may open to enclose or surround at least a portion of the end portion 321 of the tubular implant 320. The second end portion 384 of the protective sheath 380 may be located between the end portion 321 of the tubular implant 320 and the inner wall of the catheter 302. In some embodiments, the second end portion 384 of the protective sheath 380 may radially enclose substantially the entire extremity end portion 321 of the tubular implant 320. Therefore, in some embodiments, the protective sheath 380 may have a tapered shape or configuration that gradually narrows from the second end portion 384 to the first end portion 382.

[0101] In some embodiments, the protective sheath 380 may cover the end portion 321 of the tubular implant 320 over a length ranging from 5 to 10 mm, starting from the distal end of the stent 320.

[0102] In some embodiments, the second end portion 384 of the protective sheath 380 may be configured to provide a restraining force that helps hold the distal end portion 322 of the support 320 in a collapsed configuration. Alternatively, the protective sheath 380 itself does not provide a restraining force for holding the support 320 in the collapsed diameter.

[0103] In a particular embodiment, the protective sheath 380 may include a malleable ePTFE layer having a first end portion 382 that is directly or indirectly attached to a distal segment 352b of the delivery wire 352 and a second end portion 384 that encloses an end portion 321 of a support 320 in the lumen 304 of the catheter 302.

[0104] In some embodiments, the protective sheath 380 may include a continuous layer extending from a first end portion 382 to a second end portion 384. Alternatively, the protective sheath 380 may include a slit sheath construction or end portions of individual segments fixedly attached to the delivery filament 352.

[0105] refer to Figures 10 to 12 Method 800 according to embodiments of the present disclosure is now described. Method 800 can be used to deliver and deploy tubular implants such as braided stents or flow-directing stents in the blood vessels of a patient's brain.

[0106] Method 800 may begin by positioning the endovascular system within the patient's blood vessels, such as... Figure 10 As indicated in step 802. The intravascular system may include, as described herein, [the following is a continuation of the previous sentence]. Figures 8 to 9The described embodiments and other suitable systems known in the art. Generally, as Figures 8 to 9 The illustrated endovascular system 300 includes a catheter 302 having a lumen 304, a tubular implant 320 constrained within the lumen 304 of the catheter 302, and a delivery device 350. The delivery device 350 includes: a delivery wire 352; a set of or more stops 354a / 354b, 356a / 356b fixedly attached to a distal segment 352b of the delivery wire 352; one or more connectors 358, 360 respectively disposed between the set of or more stops 354a / 354b, 356a / 356b; and a protective sheath 380 including a first end portion 382 fixedly coupled to the delivery wire 352 and a second end portion 384 encasing at least an end portion 321 of the tubular implant 320 within the lumen 304 of the catheter 302. Guidewires and guiding catheters known in the art can be used when positioning the endovascular system 300. X-ray fluoroscopy, as is known in the art, can also be used when positioning the intravascular system 300. To obtain the desired position of the intravascular system 300, the physician may advance and / or withdraw the tubular implant 320 multiple times.

[0107] The tubular implant 320 can be advanced or withdrawn by the relative movement of the catheter 302 and the delivery wire 352. As an example, the catheter 302 can be withdrawn proximally to expose the protective sheath 380 and the distal portion 321 of the implant 320. Alternatively, the delivery wire 352 can be pushed distally. Stops 354a, 354b of a first set and 356a, 356b of a second set attached to the delivery wire 352 also move forward as the delivery wire 352 is pushed distally. Through openings in the first coupling 358 and the second coupling 360 allow the delivery wire 352 to pass through. The first coupling 358 and the second coupling 360 can be configured, for example, the inner and outer diameters of the couplings 358, 360 and the material of the couplings can be selected such that the delivery wire 352 can move and rotate longitudinally relative to the first coupling 358 and the second coupling 360. According to embodiments of this disclosure, a first connecting member 358 disposed between a first set of stops 354a, 354b and a second connecting member 360 disposed between a second set of stops 356a, 356b are arranged such that when the delivery filament 352 is pushed in the distal direction, the proximal stop 354b of the first set engages the first connecting member 358. Thus, a forward force is applied to the first connecting member 358 by the proximal stop 354b of the first set. The gripping between the first connecting member 358 and the braided support 320 generates a tensile force that pulls or stretches a portion 323 of the support 320 proximal to the distal portion 322 of the support 320 (e.g., the portion 323 between the first connecting member 358 and the second connecting member 360). As a result, the diameter of the support portion 323 decreases when the support 320 is pulled or stretched. The reduction in stent diameter decreases the normal force and surface area of ​​stent portion 323 against the inner surface of catheter 302, thereby reducing the total friction between stent 320 and catheter 302. The slight elongation of stent portion 323 also allows the proximal stop 356b of the second set to engage the second connector 360, thereby allowing a forward force to be applied to the second connector 360. Together, the forward force applied by the proximal stop 354b of the first set, the distal tension generated by the first connector 358 against stent portion 323, and the forward force applied by the proximal stop 356b of the second set allow stent 320, constrained within the lumen 304 of catheter 302, to move forward against relative friction. The distal tension generated by the first connector 358 against stent portion 323 reduces the overall resistance to advancing stent 320 within the lumen 304 of catheter 302.

[0108] To retract the support 320, the delivery wire 352 can be pulled in the proximal direction. The first set of stops 354a, 354b and the second set of stops 356a, 356b, fixed to the delivery wire 352, also move rearward when the delivery wire 352 is pulled in the proximal direction. According to an embodiment of this disclosure, a first connecting member 358 disposed between the first set of stops 354a, 354b and a second connecting member 360 disposed between the second set of stops 356a, 356b are arranged such that when the support 320 is retracted when the delivery wire 352 is pulled in the proximal direction, the distal stop 356a of the second set engages the second connecting member 360. Thus, a rearward force is applied to the second connecting member 360 by the distal stop 356a of the second set. The gripping force between the second connector 360 and the braided stent 320 generates a tensile force that pulls or stretches the portion 323 of the stent 320 distal to the proximal portion 324 of the stent 320 (e.g., the portion 323 between the first connector 358 and the second connector 360). As a result, the diameter of the stent portion 323 decreases when the stent 320 is pulled or stretched. This reduction in stent diameter reduces the normal force and surface area of ​​the stent portion 323 against the inner surface of the catheter 302, thereby reducing the total frictional force between the stent 320 and the catheter 302. The slight elongation of the stent portion 323 also allows the distal stop 354a of the first set to engage the first connector 358, thereby allowing a rearward force to be applied to the first connector 358. Together, the rearward force exerted by the distal stop 356a of the second group, the proximal tension generated by the second connector 360 on the stent portion 323, and the rearward force exerted by the distal stop 354a of the first group allow the stent 320, constrained within the lumen 304 of the catheter 302, to overcome relative frictional forces and move rearward. The proximal tension generated by the second connector 360 on the stent portion 323 reduces the overall resistance to retraction of the stent 320 constrained within the lumen 304 of the catheter 302.

[0109] Therefore, according to embodiments of this disclosure, the positions of the proximal stop 354b of the first group relative to the first connector 358 and the positions of the proximal stop 356b of the second group relative to the second connector 360 can be arranged such that, when the delivery wire 352 is pushed in the distal direction to advance the stent 320, the proximal stop 354b of the first group engages the first connector 358 before the proximal stop 356b of the second group engages the second connector 360. In this way, a distal-direction tension can be generated by the first connector 358 on the stent portion 323 between the first connector 358 and the second connector 360. This tension causes a slight radial contraction of the stent portion 323, thereby reducing the overall static friction between the stent 320 and the catheter 302. The elongation of the stent portion 323 caused by this tension also allows the proximal stop 356b of the second group to engage the second connector 360, thereby allowing a force to be applied to the second connector 360 to advance the stent 320.

[0110] Conversely, according to embodiments of this disclosure, the positions of the first set of distal stops 354a relative to the first connector 358 and the positions of the second set of distal stops 356a relative to the second connector 360 can be arranged such that, when the delivery wire 352 is pulled in the proximal direction to retract the stent 320, the second set of distal stops 356a engages the second connector 360 before the first set of distal stops 354a engages the first connector 358. Thus, the second connector 360 can generate a proximal-direction tension on the stent portion 323 between the first and second connectors 358. This tension causes a slight radial contraction of the stent portion 323 between the first and second connectors 358, thereby reducing the overall static friction between the stent 320 and the catheter 302. The elongation of the implant 320 caused by this tension also allows the distal stop 354b of the first group to engage the first connector 358, thereby allowing a force to be applied to the first connector 358 to retract the implant 320.

[0111] Back Figure 10 According to an embodiment of method 800, the tubular implant 320 is advanced or withdrawn to allow the end portion of the tubular implant 320, encased in a protective sheath 380, to exit the catheter 302, as indicated in step 804. For example, the delivery wire 352 may be advanced distally to allow the proximal stop 354b to engage the connector 358 and apply a translational force thereto. The gripping between the connector 358 and the braided support 320 allows the tubular implant 320, constrained within the lumen 304 of the catheter 302, to move forward against opposing frictional forces. Figure 11 The diagram schematically shows at least the end portion 321, which is enclosed by a protective sheath 380, exiting the lumen 304 of the catheter 302.

[0112] refer to Figure 10According to an embodiment of method 800, the delivery wire 352 is rotated to remove the protective sheath 380 from the tubular implant 320, as indicated in step 806. As an example, the physician may rotate the proximal segment 352a of the delivery wire 352, which can be coupled to an operating handle. The torque applied to the proximal segment 352a of the delivery wire 352 is transmitted to the distal segment 352b of the delivery wire 352. Because the first end portion 382 of the protective sheath 380 is fixedly coupled to the delivery wire 352, rotation of the delivery wire 352 causes the protective sheath 380 to rotate or wrap around the delivery wire 352, thereby pulling the second end portion 384 of the protective sheath 380 away from the end portion 321 of the tubular implant 320, thereby releasing the end portion 321 of the tubular implant 320 from the constraint of the protective sheath 380. Figure 12 The illustration schematically shows the implant portion 321 of the exit catheter 302 expanding into an expanded configuration after the restraints of the protective sheath 380 are removed.

[0113] Various embodiments of intravascular systems, delivery devices, and methods have been described with reference to the accompanying drawings. It should be noted that the aspects described in connection with a particular embodiment are not necessarily limited to that embodiment and can be practiced in any other embodiment. The drawings are intended to illustrate embodiments and are not an exhaustive description or limitation of the scope of this disclosure. Alternative structures, components, and materials will be readily recognized without departing from the principles of the claimed invention.

[0114] Unless otherwise expressly defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art. As used in the specification and appended claims, the singular forms “a,” “an,” and “described” include plural references unless the context clearly indicates otherwise. The term “or” means a non-exclusive “or” unless the context clearly indicates otherwise. The term “proximal” and its grammatical equivalents refer to a position, direction, or orientation toward the user or physician. The term “distal” and its grammatical equivalents refer to a position, direction, or orientation away from the user or physician. The names “backward,” “forward,” etc., do not imply limitation of the referenced components to a particular orientation. It should be understood that such designation refers to the orientation of the referenced components as shown in the accompanying drawings; the systems and devices of this disclosure can be used in any orientation suitable for the user. The terms “first” or “second,” etc., can be used to distinguish one element from another when describing various similar elements. It should be noted that the terms “first” and “second” as used herein include references to two or more. Furthermore, the use of the terms "first" or "second" should not be construed as indicating any particular order unless the context explicitly indicates otherwise. In alternative embodiments, the order in which the method steps are performed may be changed. One or more method steps may be skipped entirely, and one or more optional steps may be included. All numerical values ​​are provided for illustrative purposes and are assumed to be modified by the term "about," whether explicitly indicated or not. The term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the stated value, for example, having the same function or result. The term "about" may include numbers rounded to the nearest significant digit. The description of a range of numerical values ​​at its endpoints includes all numbers within that range.

[0115] Those skilled in the art will understand that various other modifications can be made. All such and other variations and modifications were conceived by the inventors and are within the scope of this invention.

Claims

1. An intravascular system, the intravascular system comprising: The catheter has a lumen; A tubular implant having a collapsed state for placement within the lumen of the catheter and an expanded state when not constrained by the catheter; as well as A delivery device operable to deliver the tubular implant through the catheter, wherein the delivery device comprises: A delivery filament having a distal segment and a proximal segment; A set of stoppers, the set of stoppers including a first set of stoppers and a second set of stoppers; the set of stoppers includes a distal stopper and a proximal stopper respectively fixedly attached to the distal segment of the delivery wire; A connector, comprising a first connector disposed between the first set of stops and a second connector disposed between the second set of stops, and configured to apply a radially outward force to the distal portion of the tubular implant within the lumen of the catheter to grip the tubular implant, the connector including a through opening allowing the distal segment of the delivery wire to pass through; and A protective sheath includes a first end portion fixedly coupled to the distal segment of the delivery wire and a second end portion enclosing at least a distal portion of the tubular implant within the lumen of the catheter, the second end portion of the protective sheath being configured to provide a restraining force to help retain the distal portion of the stent in a collapsed configuration; wherein the connector is configured to allow the delivery wire to slide longitudinally relative to the connector within the lumen of the catheter, thereby allowing the proximal stop and / or the distal stop to engage the connector and apply a translational force to the connector to advance and / or retract the tubular implant; during stent advancement in the distal direction, The proximal stop of the first group engages the first connector before the proximal stop of the second group engages the second connector, such that the diameter of the stent portion decreases when the stent is pulled or stretched, and the elongation of the stent portion allows the proximal stop of the second group to engage the second connector; when the stent is withdrawn in the proximal direction, the distal stop of the second group engages the second connector before the distal stop of the first group engages the first connector, such that the diameter of the stent portion decreases when the stent is pulled or stretched, and the elongation of the stent portion allows the distal stop of the first group to engage the first connector; and allows the delivery wire to rotate relative to the connector, thereby removing the protective sheath from the tubular implant.

2. The intravascular system according to claim 1, wherein, The distal segment of the delivery wire includes an end segment angled from the longitudinal axis of the catheter, whereby rotation of the delivery wire allows the end segment to change orientation to facilitate delivery and / or deployment of the tubular implant in the patient’s tortuous blood vessels and / or avoid entry into branches of the blood vessel in which the tubular implant is deployed.

3. The intravascular system according to claim 1, wherein, The protective sheath is constructed from a polymer material including expanded polytetrafluoroethylene (ePTFE).

4. The intravascular system according to claim 1, wherein, The connector is constructed from an elastic polymer material.

5. The intravascular system according to claim 1, wherein, The connector is in the form of a cylindrical tubular body made of silicone resin.

6. The intravascular system according to claim 1, wherein, The tubular implant includes a woven structure.

7. The intravascular system according to claim 6, wherein, The braided structure is constructed from two or more composite wires, each composite wire including an inner core of a first material and an outer shell of a second material different from the first material.

8. The intravascular system according to claim 7, wherein, The first material of the inner core comprises a nickel-cobalt alloy, and the second material of the outer shell comprises a nickel-titanium alloy.

9. The intravascular system according to claim 8, wherein, The two or more composite wires comprise a fill percentage of the inner core ranging from about 5% to 30%.

10. The intravascular system according to claim 1, wherein, The first connector is configured to apply a radially outward force to the distal portion of the tubular implant in the lumen of the catheter, and the second connector is configured to apply a radially outward force to the proximal portion of the tubular implant in the lumen of the catheter.

11. The intravascular system of claim 1, further comprising a buffer member fixedly coupled to the delivery wire and positioned adjacent to the proximal end of the tubular implant.

12. A method for delivering a tubular implant, the method comprising: An endovascular system is positioned in a patient's blood vessel, the endovascular system including a catheter having a lumen, a tubular implant constrained within the lumen of the catheter, and a delivery device, wherein the delivery device includes a delivery wire, a set of stops, a connector, and a protective sheath; the set of stops includes a first set of stops and a second set of stops, the set of stops including a distal stop and a proximal stop fixedly attached to the delivery wire; the connector includes a first connector disposed between the first set of stops and a second connector disposed between the second set of stops, and is configured to contact the distal portion of the tubular implant within the lumen of the catheter and apply a radially outward force thereto to grasp the tubular implant; the protective sheath includes a first end portion fixedly connected to the delivery wire and a second end portion enclosing at least a distal portion of the tubular implant within the lumen of the catheter, the second end portion of the protective sheath being configured to provide a restraining force to help hold the distal portion of the stent in a collapsed configuration; via the guide The relative movement of the tube and the delivery wire advances or withdraws the tubular implant, allowing the proximal stop to engage the connector and apply a translational force to the connector. During distal advancement of the stent, the proximal stop of the first group engages the first connector before the proximal stop of the second group engages the second connector, such that the diameter of the stent portion decreases as the stent is pulled or stretched, and the elongation of the stent portion allows the proximal stop of the second group to engage the second connector. During proximal withdrawal of the stent, the distal stop of the second group engages the second connector before the distal stop of the first group engages the first connector, such that the diameter of the stent portion decreases as the stent is pulled or stretched, and the elongation of the stent portion allows the distal stop of the first group to engage the first connector, thereby withdrawing the end portion of the tubular implant, which is enveloped by the second end portion of the protective sheath, from the lumen of the catheter. The delivery wire is rotated to allow the protective sheath to twist, thereby removing the second end portion of the protective sheath from the end portion of the tubular implant.

13. The method according to claim 12, wherein, The protective cover is constructed from a flexible polymer material.

14. The method according to claim 12, wherein, The protective sheath is constructed from a polymer material including expanded polytetrafluoroethylene (ePTFE).

15. The method according to claim 12, wherein, The tubular implant includes a woven structure.

16. The method according to claim 15, wherein, The braided structure is constructed from two or more composite wires, each composite wire including an inner core of a first material and an outer shell of a second material different from the first material.

17. The method according to claim 16, wherein, The first material of the inner core comprises a nickel-cobalt alloy, and the second material of the outer shell comprises a nickel-titanium alloy.

18. The method according to claim 17, wherein, The two or more composite wires comprise a fill percentage of the inner core ranging from about 5% to 30%.

19. The method according to claim 12, in, The first connector is configured to apply a radially outward force to the distal portion of the tubular implant in the lumen of the catheter, and the second connector is configured to apply a radially outward force to the proximal portion of the tubular implant in the lumen of the catheter. and In the relative movement of the catheter and the delivery wire, the proximal stop of the first group engages the first connector and applies a translational force to the first connector, and the proximal stop of the second group engages the second connector and applies a translational force to the second connector.

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