Systems and methods for treating vascular disease - Patents.com

Abstract

A flow diverter including a self-expanding tubular member having a plurality of expandable cells, each of the expandable cells having interconnected struts and bridges. The tubular member has a constrained configuration having a first outer diameter sized for delivery with a flow diverter delivery system of at least 1.0 mm, and a deployed configuration having a second diameter greater than the first outer diameter. The tubular member has a proximal end zone, a distal end zone, and an intermediate zone, the intermediate zone being located between the proximal end zone and the distal end zone. At least the intermediate zone of the tubular member is laser cut and has at least 25% material coverage when the tubular member is in the deployed configuration. Related devices, systems, and methods are provided for treating diseases, particularly cerebral and intracranial aneurysms, by deploying a deployable deployable device.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. application Ser. No. 63 / 338,114, filed May 4, 2022, U.S. application Ser. No. 63 / 346,524, filed May 27, 2022, and U.S. application Ser. No. 63 / 422,762, filed November 4, 2022, the disclosures of which are incorporated herein by reference in their entireties.

[0002] [Technical field] The present technology relates generally to medical device systems and methods, and more particularly to medical device delivery and methods for the placement of stents or flow diverters for the treatment of vascular disease, such as intracranial aneurysms. [Background technology]

[0003] Intravascular placement of scaffolding devices such as flow diverters has been used to treat aneurysms in blood vessels of the brain (e.g., cerebral arteries) or blood vessels leading to the brain (e.g., intracranial arteries). Flow diverters are particularly useful in treating wide-necked aneurysms that are difficult to eliminate by other means, such as embolic coils. Flow diverters are intended to be positioned to begin at the distal normal portion, span the aneurysm, and terminate at the proximal normal portion. Flow diverters are designed to have a very high density of material coverage, about 30%, when deployed (or expanded), to block or restrict blood flow into the aneurysm through the aneurysm neck. Eliminating blood flow into the aneurysm reduces or eliminates the risk of aneurysm rupture due to thrombosis at that site over time.

[0004] Typically, intravascular placement of devices in cerebral and intracranial arteries has been accomplished through smaller sized delivery systems. Access with larger diameter systems is difficult, in part, due to the small size and delicate nature of the vessels, as well as the tortuosity of the intracranial vasculature. Navigating these arteries to deliver intravascular implants, such as flow diverters, requires catheter systems with good flexibility and deliverability, which can be challenging, especially for larger diameter catheters. Due to the difficulty of advancing larger diameter delivery systems to these anatomical structures, flow diverters and other intravascular implants have typically been delivered through microcatheters with inner diameters of 0.027 inches or smaller. Furthermore, the implants are typically pushed through these catheters rather than delivered pre-mounted at the distal end of the delivery system, as is standard practice for self-expanding stents in larger, more accessible locations. This method requires additional steps and wire exchanges, increasing the time and risk of the procedure.

[0005] To achieve the high percentage of metal coverage that achieves the desired thrombotic effect, all currently available flow diverters are based on braided wire structures. The braided structures can be deployed in vessels with diameters deliverable through a 0.027 inch inner diameter microcatheter up to a maximum desired vessel diameter of 5 mm (0.2 inch) and still have a percentage of metal coverage of 30% in the deployed structure. Examples include Medtronic's PIPELINE, Stryker's SURPASS, Terumo's FRED, etc. In contrast, stents constructed from laser-cut metal tubes such as Nitinol, stainless steel, and other alloys cannot achieve the desired percentage of metal coverage of at least 30% due to geometric limitations.

[0006] Unfortunately, braided flow diverters can be difficult, time consuming, inaccurate, and potentially dangerous to deliver. One problem with braided, self-expanding implants, such as braided flow diverters, is that they may not immediately fully deploy to the vessel wall and therefore may move during deployment, making it a time consuming and dangerous operation to achieve the desired wall coverage, location, and wall apposition. Significant shortening of the braided flow diverter is also problematic during deployment due to the nature of the braided structure, often resulting in ineffective coverage of the aneurysm site and often requiring repositioning, manipulation, or the placement of additional implants. For these reasons, coverage and / or apposition of the flow diverter to the wall of the aneurysm is often not optimal. Poor apposition is associated with a high probability of stenosis or occlusion of the flow diverter.

[0007] In addition, due to the difficulty of advancing large diameter delivery systems into the distal carotid and cerebral anatomy, devices such as flow diverters are typically delivered through microcatheters with an inner diameter of 0.027 inches or smaller. The delivery systems for such devices often include a leading distal guidewire tip, which poses the risk of vessel perforation. Furthermore, braided implants such as flow diverters that terminate on a wire end often require delivery systems with additional distal end restricting features to allow the device to be pushed through the microcatheter. Such restricting features add additional time and complexity to the deployment procedure.

[0008] There is a need for improved flow diverters that can be delivered through larger bore access systems to optimally access cerebral and intracranial arterial aneurysms for the treatment of these sites while providing adequate vascular coverage and improved deliverability and deployment characteristics. There is also a need for improved flow diverter delivery systems that are compatible with these larger bore access devices and that can deliver the flow diverter accurately and quickly with minimal steps. Summary of the Invention

[0009] In one embodiment, provided is a self-expanding tubular member including a plurality of expandable cells, each of which has interconnected struts and bridges. The tubular member has a constrained configuration having a first outer diameter sized for delivery using a flow diverter delivery system of at least 1.0 mm, and a deployed (or expanded) configuration having a second outer diameter greater than the first outer diameter. The tubular member has a proximal end zone, a distal end zone, and an intermediate zone located between the proximal end zone and the distal end zone. At least the intermediate zone of the tubular member is laser cut to have at least 25% material coverage when the tubular member is in the deployed configuration.

[0010] The interconnected struts and bridges of each expandable cell may include two pairs of struts, each strut of the two pairs of struts having an outer edge. The outer edge of a first strut of the first pair may be interconnected with an outer edge of a second strut of the first pair by one of the bridges. The first strut of the first pair of struts may be connected to a first strut of the second pair of struts at a central curve, and the second strut of the first pair may be connected to a second strut of the second pair at a central curve. The circumferential (or circumferential) height from the central curve of the first pair to the outer edge of the first pair is Y, and the axial distance from the central curve of the first pair to the outer edge of the first pair is X, where the diagonal of the rectangle defined by X and Y may be equal to the length of the first strut. The ratio of the length of the first strut to the circumferential height (or length) of the first strut may be between 1 and 5. Each pair of struts may be arranged parallel to one another and axially spaced from one another, thereby defining a V-shaped opening of the expandable cell. The two pairs of struts may be interconnected to form a peak at a first end of the expandable cell and a corresponding valley at a second end of the expandable cell. The plurality of expandable cells may be arranged in a circumferential ring, with each peak of the circumferential ring of expandable cells being circumferentially aligned with each peak of an adjacent circumferential ring of expandable cells. A bridge may connect the peak of the expandable cell of the first circumferential ring to the valley of the expandable cell of the adjacent second circumferential ring.

[0011] The intermediate zone can have different properties than one or both of the proximal end zone and the distal end zone. The intermediate zone can have a greater material coverage than one or both of the proximal end zone and the distal end zone. One or both of the proximal end zone and the distal end zone can be laser cut to have a lesser material coverage than the intermediate zone. The intermediate zone can have a material coverage of 25% to 35% when the tubular shape is in a deployed configuration, and the proximal end zone and the distal end zone can have a lesser material coverage than the intermediate zone. At least one of the proximal end zone, the intermediate zone and the distal end zone can include at least one radiopaque marker. The length of the flow diverter in the constrained configuration can differ from the length of the flow diverter in the deployed configuration by less than 1%. The length of the flow diverter in the constrained configuration can differ from the length of the flow diverter in the deployed configuration by less than about 5%. The length of the flow diverter in the restrained configuration may differ from the length of the flow diverter in the deployed configuration by less than about 10%.

[0012] The first outer diameter may be between 1.5 mm and 2.5 mm, and the second outer diameter is between 2.0 mm and 6.0 mm. The length of the flow diverter in the constrained configuration may be between 10 mm and 35 mm. The plurality of expandable cells of the tubular member may be arranged as between 10 and 50 circumferential rings. The pitch of the intermediate zone may be between about 0.25 mm and 0.40 mm, the pitch corresponding to the bridge length of the expandable cells of the intermediate zone. The pitch of one or both of the proximal end zone and the distal end zone may be between 0.45 mm and 0.75 mm, the pitch corresponding to the bridge length of the expandable cells of the proximal end zone or the distal end zone. The plurality of expandable cells may form a row extending parallel to the longitudinal axis of the tubular member and between the proximal and distal ends of the tubular member, the row of expandable cells being aligned peak-to-valley. The tubular member may include between 4 and 10 rows.

[0013] At least the distal end zone may include rails formed of bridges interconnecting a plurality of expandable cells in rows. The rails allow the distal end zone to be resheathed in the delivery system after at least partial deployment of the distal end zone. One or both of the proximal end zone and the distal end zone may include a braided or woven structure. The interconnected struts may be connected by a plurality of V-shaped hinges. A line connecting radially adjacent hinges may pass through at least four cells in the intermediate zone. A line connecting radially adjacent hinges may pass through fewer cells in the proximal and distal zones than in the intermediate zone. The bridges located in the intermediate zone may be shorter than the bridges located in the distal and proximal end zones. The struts in the intermediate zone, the distal end zone and the proximal end zone may be substantially the same in length and structure. The bridges may be located parallel to a central axis of the flow diverter.

[0014] In a related aspect, provided is a method of treating an intracranial or cerebral aneurysm comprising advancing a catheter system through a base sheath toward an intracranial or cerebral vessel having an aneurysm in it, the catheter system including an inner catheter having a tubular elongate body with a single lumen and a flexible distal tapered end region, and an outer catheter having a catheter lumen and a distal end. The method includes positioning a tapered end region of the inner catheter distal to the distal end of the outer catheter, passing at least a portion of the tapered end region of the inner catheter through a section of the blood vessel containing the aneurysm, advancing the outer catheter over the inner catheter to position the distal end region of the outer catheter across the lesion, withdrawing the inner catheter from the catheter lumen and holding the outer catheter in a position across the aneurysm, advancing a flow diverter delivery system including a flow diverter through the catheter lumen to the distal end region of the outer catheter, withdrawing the outer catheter while holding the flow diverter delivery system in place, and deploying the flow diverter across the section containing the aneurysm.

[0015] In a related aspect, provided is a method of performing a medical procedure at a treatment site in a patient's brain, comprising placing a system of devices in an advanced configuration. The system of devices includes a catheter having a catheter lumen, an inner diameter, and a distal end, and an inner (or internal) member sized and shaped for sliding within the catheter lumen. The inner member defines a single lumen and has a distal portion. The distal portion has a first outer diameter that tapers distally to a smaller second outer diameter, the inner member transitioning in flexibility from its proximal end to its distal end, the inner member's distal end being more flexible than the catheter's distal end. When the inner member is placed in the advanced configuration, the inner member extends coaxially through the catheter inner diameter until the distal portion of the inner member is distal to the catheter's distal end. The method includes advancing a catheter and a flexible inner member to a desired location relative to an access point of entry while the system of devices is in an advanced configuration, positioning the catheter at a treatment site having an aneurysm, removing the inner member from the patient, and treating the aneurysm via the catheter. The treatment step can include delivering a flow diverter to the aneurysm via the catheter.

[0016] In a related aspect, provided is a flow diverter delivery system including a flow diverter having a tubular structure and configured to treat an aneurysm of an intracranial vessel, the flow diverter including a constrained structure having a first outer diameter and a deployed structure having a second outer diameter, and an inner core member including an elongate shaft including a recessed region near a distal end region, the recessed region sized to receive the tubular structure of the flow diverter in the constrained configuration, and an atraumatic distal tip region distal to the recessed region. The distal tip region tapers from the first outer diameter of the elongate shaft to the second outer diameter of the elongate shaft. The first outer diameter of the elongate shaft is greater than the outer diameter of the recessed region. The system includes an outer restraining sleeve having an inner diameter sized to receive the inner core member and the flow diverter in the constrained configuration. The outer restraining sleeve can be retracted at least a distance to deploy the flow diverter.

[0017] The inner diameter of the constraining sleeve can be sized to fit over the first outer diameter of the elongate shaft, eliminating an annular space at the distal end of the flow diverter delivery system. The distal tip region can include at least one radiopaque marker at the distal end. The distal tip region can include a second radiopaque marker positioned to identify the taper.

[0018] In a related embodiment, provided is a flow diverter having a self-expanding tubular member having a proximal end, a distal end, and a longitudinal axis. The tubular member has a constrained configuration with a first outer diameter sized for delivery and a deployed configuration with a second outer diameter larger than the first outer diameter. The tubular member includes a plurality of expandable cells, each of the cells having interconnected struts and bridges arranged in a circumferential ring-like fashion. The circumferential rings form an array of expandable cells extending parallel to the longitudinal axis between the proximal and distal ends of the tubular member, the arrays of expandable cells overlapping (or nesting) at peaks and valleys. The tubular member has a proximal end zone near the proximal end of the tubular member, a distal end zone near the distal end of the tubular member, and an intermediate zone located between the proximal end zone and the distal end zone. At least the distal end zone includes at least one rail formed from bridges interconnecting each of the circumferential rings of each of the expandable cells in a single row.

[0019] The at least one rail can enable the distal end zone to be resheathed within the delivery system after at least partial deployment of the distal end zone from the delivery system.At least the intermediate zone of the tubular member can be laser cut such that the tubular member has at least 25% material coverage in a deployed configuration.

[0020] In a related aspect, provided is a flow diverter configured to deploy from a constrained state to a deployed state. The flow diverter includes a first tube of superelastic material formed from a plurality of cells having a first material coverage and a second tube of superelastic material formed from a plurality of cells having a second material coverage. The second tube is disposed inside the first tube such that in the deployed state of the flow diverter, an overlap of the plurality of expandable cells of the first tube and the second plurality of expandable cells forms a third material coverage that is greater than the first material coverage and the second material coverage.

[0021] At least one of the first and second tubes may have cut pattern features that allow the second tube to be fastened in place inside the first tube. The features may include a slot in the first or second tube and a tab configured to protrude into the slot and fasten the first and second tubes together. The features may include a hole in the first or second tube and a malleable disk configured to be inserted into the hole and fasten the first and second tubes together. At least one of the first and second tubes may be non-braided and laser cut. [Brief description of the drawings]

[0022] These and other aspects will now be described in detail with reference to the following figures, in which: The figures are generally not to scale in an absolute sense or in a relative sense, but are intended to aid in understanding, and the relative placement of features and elements may be modified for purposes of clarity of illustration.

[0023] [Figure 1A] FIG. 1A is an embodiment of a cut tube flow diverter in a contracted delivery configuration. [Figure 1B] FIG. 1B is the flow diverter of FIG. 1A in a deployed configuration. [Figure 1C] FIG. 1C is the flow diverter of FIG. 1B in an unfolded configuration, showing a top (unfolded) view of the device pattern. [Figure 1D] FIG. 1D is an interrelated embodiment of a cut tube flow diverter. [Figure 1E] FIG. 1E is the flow diverter of FIG. 1D, showing a plan (developed) view of the device pattern. [Figure 1F] FIG. 1F is the flow diverter of FIG. 1D in a cut configuration, showing details of the cut pattern. [Figure 2A] FIG. 2A shows a cell that is a portion of the flow diverter of FIG. 1C. [Figure 2B] FIG. 2B shows cells in various portions of the flow diverter of FIG. 1C having different pitches. [Figure 2C] FIG. 2C shows cells in various portions of the flow diverter of FIG. 1C having different pitches. [Figure 2D] FIG. 2D shows cells in various portions of the flow diverter of FIG. 1C having different pitches. [Diagram 3] FIG. 3 shows additional details of an embodiment of a cut tube flow diverter. [Figure 4A] FIG. 4A shows details of the attachment mechanism between the two layers of the dual flow diverter. [Figure 4B] FIG. 4B shows details of the attachment mechanism between the two layers of the dual flow diverter. [Figure 4C] FIG. 4C shows details of the attachment mechanism between the two layers of the dual flow diverter. [Figure 5A] FIG. 5A details an alternative attachment mechanism between the two layers of a dual flow diverter. [Figure 5B] FIG. 5B details an alternative attachment mechanism between the two layers of the dual flow diverter. [Figure 6A] FIG. 6A shows an embodiment of a dual layer flow diverter. [Figure 6B] FIG. 6B shows an embodiment of a dual layer flow diverter. [Figure 7] FIG. 7 shows an embodiment of a composite flow diverter. [Figure 8A] FIG. 8A shows the components of the flow diverter and the delivery system of the flow diverter. [Figure 8B] FIG. 8B shows the flow diverter and delivery system of FIG. 8A assembled in a delivery configuration. [Figure 8C] FIG. 8C shows the flow diverter of FIG. 8B with the flow diverter partially deployed and a delivery system. [Figure 9A] FIG. 9A shows an access catheter system for accessing an arterial treatment site. [Figure 9B]FIG. 9B shows the access catheter system of FIG. 9A assembled for use. [Figure 10A] FIG. 10A is a detailed view of the distal end region of the catheter advancement element taken along circle CC of FIG. 9A. [Figure 10B] FIG. 10B is a detailed view of the distal end region of the catheter advancement element of FIG. 10A, with a guidewire disposed within the lumen of the catheter advancement element. [Figure 11A] FIG. 11A shows an assembled catheter system accessing an intracranial aneurysm with a base sheath placed in the internal carotid artery (ICA), an outer catheter advanced distal to the ICA, and an inner catheter passing through the vessel in the area of ​​the aneurysm. [Figure 11B] FIG. 11B shows the outer catheter of FIG. 11A advanced through the aneurysm and the inner catheter withdrawn. [Figure 11C] FIG. 11C shows the flow diverter delivery system advanced through the aneurysm and the outer catheter withdrawn. [Figure 11D] FIG. 11D shows the flow diverter being withdrawn, the restraining sleeve, and the flow diverter being deployed through the aneurysm. [Figure 12A] FIG. 12A is a plan (unfolded) view of an interrelated embodiment of a cut tube flow diverter in a contracted state. [Figure 12B] FIG. 12B shows a detailed portion of the flow diverter of FIG. [Figure 13] FIG. 13 is a plan (unfolded) view of an interrelated embodiment of a cut tube flow diverter in a contracted state. [Figure 14] FIG. 14 is an interrelated embodiment of a cut tube flow diverter with flared ends.

[0024] It should be understood that the figures are for example purposes only and are not meant to be to scale. The figures are intended to aid in understanding of features, including metal coverage percentages. The figures are not to scale in an absolute sense or relative to scale. It should be understood that devices described herein may include features not necessarily depicted in each figure. DETAILED DESCRIPTION

[0025] Described herein are flow diverters, delivery systems and methods that are compatible with large-bore access systems. These devices, systems and methods improve upon current braided flow diverters and associated microcatheter-based delivery systems to allow for more precise, safe and rapid treatment of aneurysms utilizing large-bore access systems. These devices and systems can be delivered via any large-bore cerebrovascular access system. Also described are improved large-bore access systems that facilitate speed, safety and ease of accessing cerebral arteries and intracranial aneurysms despite navigational difficulties.

[0026] When the term "access catheter" is used herein, such catheters may be used for other purposes, such as for accessing, or for delivering fluids to a treatment site, or as an aspiration catheter. In another embodiment, the access systems described herein may also be useful for accessing other parts of the body outside the vasculature. Similarly, other interventional devices may be delivered using the access and delivery systems described herein, where the device in question is described as a deployable intracranial treatment device or flow diverter. As used herein, "aneurysm" refers to a bulging area of ​​weakness in the wall of a blood vessel. "Cerebral aneurysm" or "intracranial aneurysm" refers to an aneurysm in the blood vessels of the brain.

[0027] Flow Diverter Disclosed herein is a flow diverter with greatly improved deployment and performance compared to current braided flow diverters. The flow diverter is a self-expanding, cut tube type implant, unlike wire tubes, that can be deployed to its full diameter much more quickly and accurately. The cut tube structure does not have wire ends as braided implants do, and therefore does not need to constrain or cover the distal end of the implant. The cut tube flow diverter described herein also does not encounter significant foreshortening as braided wire scaffolds do. The cut pattern can be designed to achieve wall apposition and coverage sufficient to divert, prevent, or block blood flow into the aneurysm and / or isolate the aneurysm with a single piece of material, resulting in a smoother and less thrombogenic interior surface.

[0028] 1A-1C and 1D-1F show an embodiment of a cut-tube type flow diverter 700. In each embodiment, the flow diverter 700 is a generally unbraided tubular member or element having an open distal end 707 and an open proximal end 709, with the distal end 707 being further from the user during advancement through the vessel and the proximal end 709 being closer to the user during advancement through the vessel. A longitudinal axis extends between the distal end 707 and the proximal end 709. FIG. 1A shows the flow diverter 700 in a constrained configuration having a first outer diameter OD1 and a first length L1. The first outer diameter OD1 is adapted for inserting the flow diverter into and guiding it through the vasculature to a treatment site. FIG. 1B shows the flow diverter 700 in a deployed configuration having a second outer diameter OD2 and a second length L2. Upon reaching the treatment site, the flow diverter 700 is deployed and expands to a second outer diameter OD2, where OD2 is therefore greater than OD1.

[0029] The constrained outer diameter OD1 of the flow diverter 700 can be about 0.035 inches to about 0.118 inches, preferably about 0.06 inches to about 0.10 inches, or about 1.60 mm. This constrained outer diameter OD1 is relatively large compared to the constrained outer diameter of conventional braided flow diverters. This is made possible by the larger diameter large bore access system described herein that is configured to reach distal sites for deployment of the flow diverter. Delivery of the large bore access system, described in more detail below, allows for delivery of flow diverters with larger constrained outer diameter OD1 and also allows for a structure with greater material coverage when the flow diverter is deployed.

[0030] The deployed outer diameter OD2 of the flow diverter 700 can be from about 2 mm (0.08 inches) to about 6 mm (0.24 inches), preferably from about 2.5 mm (0.1 inches) to about 5 mm (0.2 inches), depending on the anatomical requirements. When deployed, the flow diverter 700 is preferably suitable for blood vessels up to 5 mm in diameter. The length L1 of the flow diverter can also be manufactured depending on the anatomical requirements. For example, the length L1 of the flow diverter before deployment can vary from 10 mm to 50 mm or any dimension therebetween, preferably from 10 mm to 35 mm.

[0031] The length L2 of the deployed flow diverter may be in the same range. The cut tube flow diverter 700 described herein exhibits minimal shortening when deployed in a vessel from a constrained state to a deployed state. This provides an advantage over braided wire flow diverters, which shorten significantly upon deployment. Flow diverters of the configuration shown in Figures 1A-1C and 1D-1F shorten less than 10%, less than 5%, or about 1% or less when deployed from about 1.6 mm to about 4.0 mm. For example, the constrained length L1 can be about 20.7 mm and the deployed length L2 can be about 20.5 mm, which is less than about 1% shortening. In contrast, a braided stent shortens about 50% when deployed to 4 mm (see instructions for use of the Stryker Neurovascular Surpass Evolve flow diverter system). This large foreshortening of the braided flow diverter requires precise placement of the distal end to ensure adequate coverage of the target area. The distal end must extend from a site distal to the aneurysm at the normal vessel so that the midsection of the flow diverter can be positioned across the aneurysm neck and relative to the normal vessel proximal to the aneurysm. Large foreshortening of the flow diverter can result in "mis"deployment, especially in curved or convoluted anatomical structures. When the aneurysm neck is very large or the vessel tapers at the aneurysm neck, the final length and placement is even less predictable.

[0032] The flow diverter 700 can achieve a material coverage suitable for treating an aneurysm when the tubular member is in a deployed state. The material coverage (also referred to herein as material density) can vary, but is typically about 25% to 35% material coverage (+ / - 5%). As used herein, "material coverage" refers to the surface area of ​​the outer surface of the flow diverter divided by the surface area of ​​the lumen of the blood vessel. The components of the flow diverter provide material coverage, which is the inverse of the porosity of the flow diverter and a function of the amount of free space in the deployed flow diverter.

[0033] 1C and 1E are exploded views of the flat pattern of the flow diverter. The flow diverter 700 includes a plurality of repeating cells 750 arranged in a plurality of circumferential rings 760 that repeat along the axial length of the flow diverter between a proximal end 709 and a distal end 707. The cells 750 are aligned with adjacent cells 750 radially and circumferentially to form a repeating zigzag pattern. The cells 750 are aligned axially such that they overlap each other to create a plurality of axial rows 765. Thus, the number of axial rows 765 is controlled by the number of cells 750 around the circumference of the flow diverter within one ring 760.

[0034] The flow diverter may be a tubular member having a circumferential ring of self-deploying, expandable cells 750. Each of the cells 750 includes interconnected struts and an axial bridge. FIG. 2A shows a single cell of the flow diverter 700 of FIGS. 1A and 1D, including an arrangement of interconnected struts 751 and an axial bridge 752. Each cell 750 may be formed by four struts 751 with a first two struts of the four struts 751 connected at a first central bend or hinge to form a V-shape and a second two struts of the four struts 751 connected at a second central bend or hinge to form a V-shape. The central bends (also referred to herein as hinges) are aligned and spaced apart a distance such that pairs of struts 751 are spaced apart from each other. Stated another way, each cell incorporates two V-shaped struts 751, each including a central curve and two straight arms projecting in opposite directions at angles away from the central curve. The struts 751 of each cell 750 are positioned such that the central curves overlap at a fixed distance. The angles of the central curves may be equal such that the struts 751 are positioned parallel to one another, thereby defining a V-shaped opening in each cell 750. Whether a cell 750 is considered to have two V-shaped struts or four struts arranged in two V-shapes, the multiple struts 751 form a zigzag pattern around the circumference of the flow diverter 700. Additionally, the zigzag pattern of struts 751 need not be limited to a V-shape, but can include "W-shaped," "M-shaped," or "Z-shaped" strut patterns, as well as other strut patterns such as diamond-shaped or patterns forming open or closed cell structures.

[0035] Each expandable cell 750 with a V-shaped opening 754 forms a valley 753 that is open toward the proximal end 707 of the flow diverter 700 and a peak 757 that protrudes toward the distal end 707 of the flow diverter. The peak 757 is formed by a central curved portion 758 between two struts 751, and the valley 753 is formed by the central curved portions 758 of the other two struts 751. A first pair of struts 751 may be connected to each other at a first edge of the cell 750 by a first bridge 752, and a second pair of struts 751 may be connected to each other at an opposite edge of the cell 750 by a second bridge 752. A third bridge 752 may connect the peak 757 of one cell 750 to the valley 753 of an adjacent cell 750, as described in more detail below.

[0036] The V-shaped openings 754 formed by the struts 751 and connecting bridges 752 may be repeated around the circumference of the flow diverter 700 to form one of a number of circumferential rings 760. The pattern of cells 750 may be repeated multiple times along the axial length of the flow diverter 700, thereby defining a number of rings 760. Depending on the desired overall axial length and cell density, the flow diverter 700 may include between 10 and 50 rings 760, and may include anywhere between 10 and 50 zigzag V-shaped cells 750, depending on the overall length of the flow diverter 700 and the needs of the anatomy being treated. The pattern of cells 750 may be repeated multiple times around the circumference of the tubular structure of the flow diverter 700, thereby defining a number of rows 765. The number of rows 765 may vary depending on the desired dimensions of the flow diverter 700. For dimensions typical for treating cerebral aneurysms and intracranial aneurysms, the number of rows 765 may be between 4 and 10, with a preferred number being about 6. Thus, the number of struts 751 around the circumference of the flow diverter may be between about 8 and 20, preferably about 12, in pairs. (Four struts 751 create a single cell 750 with one peak 753, so twice the number of peaks 753.) Figures 1C and 1E show a row 765 that includes cells 750 with peaks 757 and valleys 753 that open from the distal end 707 of the flow diverter toward the proximal end 709 of the flow diverter. With this arrangement, a single ring 760 includes six rows 765 of complete cells 750.

[0037] 1C and 1E, the rings 760 of cells 750 may be connected to adjacent rings 760 via bridges 752. The bridges 752 connect the peaks 757 of a first cell of the first ring 760 to the valleys 753 of adjacent cells 750 of the second ring 760. The peak-valley connections allow the rings 760 of each V-shaped cell 750 to closely overlap one another in the contracted configuration and maintain high material coverage when deployed to the deployed configuration. The close overlap and high material coverage upon deployment is also a function of the long struts 751 and the relatively short bridges 752 connecting at the peaks and valleys.

[0038] The axial length of these bridges 752 controls the axial spacing between the struts 751 of the cells 750, and is referred to herein as the pitch P (see FIG. 2A). This axial length and axial spacing is one factor that controls the material coverage of the flow diverter and the porosity of the flow diverter, which is the inverse of material coverage. The material of the struts 751 provides the material coverage and the openings 754 between the struts 751, and the openings 765 between the cells 750 create the open space of the flow diverter, which is the porosity.

[0039] 2A-2D show a single cell 750 formed from interconnected struts 751 and axial bridges 752. As described above, each of the cells 750 may be formed by four struts 751. The four struts 751 may be grouped into pairs. Each strut of the two pairs of struts may include an outer edge 755. The outer edge 755a of a first strut of the first pair is interconnected by one of the axial bridges 752a to a corresponding outer edge 755b of a second strut 751b of the first pair. The first strut 751a of the first pair of struts connects at a central bend 758a to a first strut 751c of a second pair of struts. The second strut 751b of the first pair connects at a central bend 758b to a second strut 751d of the second pair of struts. An outer edge 755c of a first strut 751c of a second pair of struts is interconnected to a corresponding outer edge 755d of a second strut 751d of a second pair of struts by another axial bridge 752b. A third bridge 752c projects distally from the central curved portion 758a.

[0040] 2A-2D, Y is the circumferential height occupied by a single strut 751 from the central curved portion 758 proximal to the peak 757 of the cell 750 to the outer edge 755 of the cell 750. X is the axial distance occupied by a single strut 751 from the central curved portion 758 proximal to the peak 757 of the cell 750 to the outer edge 755 of the cell 750. The length of the strut is approximately equal to the length of the diagonal of the rectangle defined by X and Y. The ratio of the length of the strut to the circumferential height Y of the strut in the deployed configuration controls the angle of the strut 751 projecting away from the central curved portion 758 proximal to the peak 757. This ratio may be 1-5, 1-3, preferably about 2. The ratio of the radius R of each central curved portion 758 to the circumferential height Y of the strut in the constrained configuration (see FIG. 2D) controls the radius of curvature of each peak 757. The ratio may range from 2 to 10, preferably about 6. The width of the support, W S 2A, and the width of the bridge is W B The axial height of the support is X, the circumferential height is Y, and the width of the support is W. S , axial bridge length P, bridge width W Bis selected to satisfy certain criteria.

[0041] Bridges 752 are shown as connecting members that are substantially straight and lie parallel to the longitudinal axis (i.e., central axis) of the flow diverter. Bridges 852 connect adjacent peaks and valleys to form cells 750. However, bridges 752 need not be straight, but may be curved or angled relative to the longitudinal axis of the flow diverter. Also, bridges 752 can connect at locations other than peak-valley, such as connecting midway between struts 751, or at the points where struts 751 meet the hinge (i.e., central curved portion 758). Additionally, bridges 752 are shown as being longitudinally aligned and connecting every second pair of struts. However, bridges need not be axially aligned at all, but may be axially aligned every third, fourth, fifth, or other number of pairs of struts or cells. Use of the term "axial" herein means a direction along the length of the tubular member of the flow diverter, and does not necessarily mean that the direction is parallel to the longitudinal axis of the flow diverter. For example, an "axial bridge" includes a bridge that lies parallel to the central axis of the flow diverter, and also includes a bridge that is angled, stepped, or curved relative to the central axis of the flow diverter.

[0042] In the contracted configuration as shown in FIG. 1A, the struts 751 of each cell 750 are close enough to touch or are touching in at least a portion of each cell 750. The extent of the struts 751 can be selected such that the struts 751 do not overlap one another at the constrained diameter of OD1. The area of ​​the V-shaped opening between the struts 751 of each cell 750 can be reduced to nearly zero such that only the area of ​​the V-shaped opening 754 near the center of the pair of struts, or the area between the valley 753 and peak 757 of each cell remains. In the expanded configuration as shown in FIG. 1B, the struts 751 of each cell 750 can be expanded away from one another so that they do not touch. FIG. 1F is a detailed view taken at circle A in FIG. 1E. Each strut 751 in this region is spaced apart from adjacent struts by a space as narrow as the width of the strut. This spacing between the struts 751 of the cells 750 results in high material coverage of the flow diverter in the deployed configuration. The flow diverter 700 preferably has 25% to 35% material coverage at the deployed diameter of OD2.

[0043] Table 1 below provides parameters for the example flow diverter 700 shown in FIGS. 1A-1C, including parameters such as the pitch P1 of the central portion of the flow diverter. The material coverage in the deployed configuration can be about 25% to about 35%. The outer diameter OD1 in the contracted configuration can be about 1.5 mm to about 2.5 mm. The outer diameter OD2 in the deployed configuration can be about 2 mm to about 6 mm. The length L1 of the flow diverter in the contracted configuration and the length L2 of the flow diverter in the deployed configuration can be about 10 to about 50 mm. The change in length between the contracted and deployed configurations can be less than 10%, less than 5%, and less than 1%. The number of rows 765 of the flow diverter can be about 4 rows to about 10 rows, and the number of rings 760 can be about 10 to about 30. The pitch P of each cell 750 at the densest portion of the flow diverter can be from about 0.25 mm to about 0.75 mm, depending on the desired material coverage. The circumferential height Y of a single strut can be from about 0.5 mm to about 1.5 mm, and the axial distance X can be from about 1.0 mm to about 2.0 mm. The width W of the bridge B The width W of the support can be about 0.025 to about 0.09 mm. S can be about 0.025 to about 0.09 mm.

[0044] [Table 1]

[0045] Other combinations of parameters can be selected to meet the above criteria. Other features, such as the radius of the struts and the thickness of the tube walls can also be selected to achieve the desired physical properties of the flow diverter 700. For example, the radius of the struts can be about 0.05 mm to 0.10 mm, preferably about 0.07 mm, and the thickness of the tube walls can be about 0.05 mm to 0.09 mm, preferably about 0.065 mm to 0.075 mm.

[0046] The flow diverter 700 can be constructed with a consistent pattern along its length, or the pattern can vary over its length. Additionally, the flow diverter 700 can have the same pattern of cells along its entire length, but the pitch of the cells can vary depending on the needs of the anatomy. The differences in the pattern along the length of the flow diverter 700 can be selected to modify strength and material coverage for optimal performance. The variations in the pattern can form different zones along the length of the flow diverter. Again, with reference to FIG. 1C, the ring 765 of cells 750 in the central portion of the flow diverter 700 can have a pitch P that creates a dense intermediate flow diversion zone 701. The intermediate flow diversion zone 701 of the flow diverter 700 can have a maximum material density to divert flow away from anatomical structures external to the zone, such as an aneurysm. The flow diverter can have medium density zones 702, 704 on either side of the intermediate flow diversion 701. The medium density zones 702, 704 may have a lower material density or material coverage than the intermediate zone 701. The flow diverter 700 may have two end zones 703, 705 with an even lower material density than the intermediate zones 702, 704, one of the respective medium density zones 702, 704. The material density or material coverage of the zones is a function of the pitch P or the axial spacing between adjacent struts 751, which is a function of the bridge length. At least the intermediate zone of the tubular member is laser cut to have at least about 25% material coverage when the tubular member is in a deployed configuration. The intermediate zone may have different properties than one or both of the proximal end zone and the distal end zone. The intermediate zone may have a greater material coverage than one or both of the proximal end zone and the distal end zone. One or both of the proximal end zone and the distal end zone may be laser cut to have a lesser material coverage than the intermediate zone. One or both of the proximal and distal end zones can include a different construction compared to the intermediate zone, such as a braided or woven construction.

[0047] The lengths of the different zones can be varied as well. The intermediate flow diversion zone 701 has a length L that can be designed to be longer or shorter to fit the needs of the anatomy being treated. c As an example, a flow diverter having an overall length L2 of about 20 mm may have a length L of 10 mm to 15 mm. c The flow diverter can have an intermediate flow diversion zone 701 having a length L2, a deployed outer diameter OD2, and an intermediate zone L c The length of the slit may be 0.01 to 0.05.

[0048] The intermediate flow diversion zone 701 can be formed by multiple rings 760 configured to closely overlap one another after deployment due to the relatively short lengths of bridges 752 connecting the peaks 757 and valleys 753 of cells 750 in adjacent rings 760. The length of bridges 752 controls the pitch of cells 750. The greater the length of bridges 752, the greater the pitch or spacing between struts 751 of cells 750 and the lower the material density. FIG. 2B shows cells 750 in distal end zone 703 or proximal end zone 705 with pitch P3. FIG. 2C shows cells 750 in transition or medium density zones 702 or 704 with pitch P2. FIG. 2D shows cells of intermediate flow diversion zone 701 with pitch P1. The pitch P3 of the end zones 703, 705 can be the largest, the pitch P1 of the mid-flow diversion 701 can be the smallest, and the pitch P2 of the medium density zones 702, 704 can be somewhere in between such that P3>P2>P1. The lower material coverage of the zones outside of the mid-zone 701 allows the flow diverter 700 to effectively treat aneurysms and prevent blood from entering the diseased portion of the vasculature in the mid-zone while preventing the flow diverter from occluding branch vessels, for example, near the end zones. In implementation, the axial spacing in P1 or mid flow diversion zone 701 can be about 0.25mm to 0.40mm, the axial spacing in P2 or medium density flow diversion zones 702, 704 can be about 0.35mm to 0.050mm, and the axial spread in P3 or end flow diversion zones 703, 705 can be about 0.45mm to 0.75mm. The length of the bridges in the mid zone 701, medium density zones 702, 704, distal end zone 703, and proximal end zone 705 can vary. The length of the bridges in the medium density zones 702, 704 can be at least 120% of the length of the bridges in the mid zone 701.The length of the bridges in the distal end zone 703 and the proximal end zone 705 can be at least 125% of the length of the bridges in the intermediate zone 701, and preferably about 150-300% (i.e., 1.5x-3x) of the length of the bridges in the intermediate zone 701.

[0049] Pillar width W S The strut circumferential width Y, and strut axial length X can be the same for all three zones or can vary from one zone to another to vary the density pattern and physical properties between zones. The distal end zone 703 and proximal end zone 705 can have 1 or 2 axial repeats or rings 760, the medium density zones 702, 704 can have 2 or 3 axial repeats or rings 760, and the intermediate zone 701 can have 10 to 30 axial repeats or rings.

[0050] In a related embodiment, the flow diverter may have different cut patterns at both ends to optimize deployment characteristics, resulting in an overall asymmetric structure. FIG. 12A shows a flow diverter 700 with an intermediate flow diversion zone 730 having a cut pattern similar to the intermediate flow diversion zone 701 of the flow diverter 700 of FIG. 1C. In contrast to the flow diverter 700 shown in FIG. 1C, the proximal end zone 733 and the distal end zone 734 of the flow diverter of FIG. 12A have a more traditional "stacked wave" pattern of conventional stents. The patterns of the end zones 733 and 734 can be similar to intracranial stents. Such stents are not structured for flow diversion, but rather to assist in the coiling procedure, similar to, for example, the Stryker NEUROFORM ATLAS Stent. These stents are known to be easily and precisely deployed, in contrast to braided flow diverters. The "stacked wave" pattern has fewer connections between sections and therefore opens more quickly during deployment compared to the flow diverter shown in FIG. 1C. In other words, the flow diverter of FIG. 12A reaches a fully deployed diameter when the shorter deployable portion is exposed and therefore can "settle" against the wall during most of the deployment process. The first circumferential ring of the proximal end zone 733 can have corresponding peaks that connect with valleys of the second circumferential ring of the proximal end zone 733, forming a fully dense cell in the outermost region of the proximal end zone 733. Similarly, the first circumferential ring of the distal end zone 734 can have corresponding valleys that connect with peaks of the second circumferential ring in the distal end zone 734, forming a fully dense cell in the outermost region of the distal end zone 734. In this way, the first two outer rings of both the distal end zone 734 and the proximal end zone 733 can be fully dense diamond shaped cells.

[0051] Further, with reference to FIG. 12A, moving inward toward the intermediate zone 730, each of the proximal end zone 733 and distal end zone 734 can have alternating larger and smaller rings. The one inner circumferential ring of the proximal end zone 733 can be larger than the first two circumferential rings forming the diamond shaped cell and can be larger than the adjacent circumferential ring disposed inward from the most proximal end of the device. Similarly, the one inner circumferential ring of the distal end zone 734 can be larger than the first two circumferential rings forming the diamond shaped cell and can be larger than the adjacent circumferential ring disposed inward from the most distal end of the device. This pattern of both the proximal end zone 733 and distal end zone 734 having alternating larger and smaller circumferential rings inward toward the intermediate zone can continue. The larger circumferential rings can have larger peaks and valleys in circumferential spacing and height. Every other larger peak connects to every fourth smaller valley of a neighboring smaller circumferential ring, resulting in an open cell structure where every other peak of the larger circumferential ring is not connected to an adjacent circumferential ring. The circumferential rings on both the proximal and distal sides of the intermediate zone 730 can make peak-valley contact with adjacent peaks and valleys of the circumferential rings of the intermediate zone 730, forming diamond shaped cells that are closed at both ends.

[0052] The strut pattern can also be varied in the end zones 733 and 734 to optimize the balance between flexibility and radial strength of the device. For example, as most easily seen in FIG. 12B (Detail A of FIG. 12A), some sections may have narrower struts 742 with a smaller "wavelength", while adjacent sections may have wider struts 744 with a "larger wavelength". In an embodiment, the narrower struts have a width of 0.025 inches (about 0.64 mm) and 12 waves around the circumference, while the wider struts 744 have a width of 0.047 inches (about 1.2 mm) and 8 waves around the circumference. Other strut dimensions and frequencies may also meet design requirements.

[0053] Further variations can be implemented along the length of the flow diverter 700. For example, FIG. 13 is a flat view of a flow diverter having different strut patterns from one end of the flow diverter 700 to the other. The flow diverter 700 can include a first transition section 735 between the intermediate flow diversion zone 730 and the distal end zone 734. The flow diverter 700 can include a second transition section 735 between the intermediate flow diversion zone 730 and the proximal end zone 733. The transition section 735 has a pattern density between the dense pattern density in the intermediate flow diversion zone 730 and the more open pattern density of the end zones 733, 734. The transition section 735 can have a ring of 24 struts embedded between the intermediate flow diversion zone 730 and the end zones 733, 734. The overlapping strut transition can result in increased spacing in the proximal and distal end regions of the intermediate flow diversion zone 730.

[0054] The structure of the distal end may differ from the structure of the proximal end of the flow diverter. For example, as can be seen in FIG. 13, the distal end region 738 of the flow diverter 700 formed by the two outermost circumferential rings has an "open cell" structure in which the end rows of struts are only connected to adjacent rows of struts every third wave. In other words, the larger circumferential rings can have peaks and valleys that are greater in circumferential spacing and height, such that every other larger peak of the larger circumferential ring is connected to every fourth smaller valley of the adjacent smaller circumferential ring, thereby leaving every other larger peak of the larger circumferential ring unconnected to an adjacent circumferential ring, forming an open cell structure. In contrast, the proximal end region 737 of the flow diverter 700 formed by the two outermost circumferential rings has a "closed cell" structure in which each wave is attached peak-valley to an adjacent strut, forming a diamond-shaped cell. The open cell nature of the distal end region 738 results in more rapid radial expansion of the flow diverter 700 during deployment because the end rows of struts have fewer connections to adjacent rows. The asymmetry between the distal and proximal ends can be achieved by having one end with a diamond shape and the other end with a single ring of 24 struts.

[0055] To further optimize the flexibility of the device with longitudinal stability, the width, number, and location of the axially connecting struts can be varied, such as axial struts 746 (shown in FIG. 12B) in the distal end zone 734 of the flow diverter 700, or axial struts 752 (shown in FIG. 1F) in the mid-section of the flow diverter 700. A major drawback of braided flow diverters is their tendency to shorten during deployment. Proper addition of axial struts can maintain the longitudinal stability of the device during deployment without making it overly stiff.

[0056] The ends of the flow diverter may be flared during the manufacture of the device. For example, as seen in FIG. 14, the flow diverter 700 has a flared distal end 740 and a flared proximal end 739. In this example, the distal end 740 has a more "open cell" structure such that gaps exist between the peaks. In another embodiment, the distal end 740 and the proximal end 739 have the same structure, whether closed cell, open cell, or hybrid structure. The flared angle may vary from about 15 degrees to 40 degrees, or about 20 degrees to 30 degrees, relative to the longitudinal axis of the flow diverter 700 from the proximal end to the distal end. The purpose of the flared shape is to ensure good apposition of the ends of the flow diverter to the vessel wall, even when the device is deployed in a curve. The elasticity of the nickel titanium (NiTi) cut tube device causes the flared ends to press against the outside of the curve when placed in a curve. A device without flared ends may pull away from the vessel wall on the inside of the curve. Depending on the location of the device within the curve, both ends of the device may separate from the wall, which may lead to problems with subsequent advancement or retraction of the device through the flow diverter, as well as an increased risk of device thrombosis.

[0057] The flare at the proximal end of the flow diverter can be greater than the flare at the distal end of the flow diverter. For example, the angle of flare at the proximal end can be about 40 degrees and the angle of flare at the distal end can be about 20 degrees, such that the diameter of the opening into the stent lumen at the proximal end can be about 10 mm and the diameter of the opening into the stent at the distal end can be about 7 mm. In comparison, the outer diameter in the central region of the stent can be about 4.25 mm. The length of the flare at the distal and proximal ends can each be about 3-4 mm in length, and the unflared constant OD region can be about 20-23 mm in length.

[0058] The length of the intermediate flow diversion zone 730 can be about 8 mm to 12 mm. The length of each of the end zones 733, 734 can be about 5 mm to 10 mm, with the total length being about 18 mm to 35 mm, preferably 20 mm to 30 mm. The number of overlapping struts around the circumference of the stent can be more than 12, for example about 16, aligned with a 16-strut structure in the anchor region. The gap between the struts in the intermediate flow diversion zone can be about 33 to 34 μm.

[0059] FIG. 3 shows a detail of the repeating laser cut pattern of the flow diverter 700, illustrating how the porosity of the device is defined. In this view, the V-shaped cells 750 overlap one another such that the central curvatures are aligned and the peak 757 of one cell 750 is spaced from the valley 753 of the adjacent cell 750 by the distance of the connecting bridge 752. The struts 751 of the cells 750 define a V-shaped opening 754 between them. The spacing between the cells 750 provided by the bridges 752 forms an additional V-shaped opening 756 aligned on the back side of the cells 750. The openings 754 of the cells 750 and the openings 756 between the cells 750 (when viewing the flow diverter in an upside-down position) represent the open space (AO), and the struts 751 and bridges 752 represent the metal structure (AM) of the flow diverter. The sum of the open space and the metal structure equals the area of ​​the bounding rectangle "A". The porosity (p) can be defined as the percentage of voids to the total area, p=AO / A. The coverage (c) can be defined as the percentage of metal structures belonging to the total area, c=AM / A. In the structure of the present invention, the porosity is approximately equal to 70% and the material coverage is approximately equal to 30%. Depending on whether the flow diverter cell 750 is located in the middle zone 701, the medium density zone 702, 704, or the end zone 703, 705, the typical gap between adjacent struts 751 of the cell 750, shown as d in FIG. 3, can vary. In some embodiments, the gap d between the pair of struts 751 of a single cell 750 in the middle zone can be approximately 0.08 mm. The described coverage and porosity are calculated for the flow diverter middle zone 701 with the following dimensions in the expanded structure shown in FIG. 3: The gap between the central bends of the pair of struts 751 of a single cell 750 is dX in FIG. 3. max This is the maximum gap between pairs of struts in the direction of flow, which may be approximately 0.22 mm in the middle zone 701 of the flow diverter 700. The maximum gap between pairs of struts 751 of a single cell 750 perpendicular to the flow direction is indicated by the arrows marked dY in FIG. maxand may be approximately 0.29 mm in intermediate zone 701. The area of ​​the V-shaped opening at the central curvature of the pair of struts of cell 750 (e.g., between valley 753 and peak 757) is the maximum diameter Φ of a circle that fits within opening 754. max This maximum diameter Φ max can be approximately 500 μm or less, or between about 100 μm and 500 μm, preferably about 250 μm, for the cells 750 of the intermediate zone 701. max , dY max , and Φ max The size range of dX of cell 750 can vary depending on whether the cell 750 is in the intermediate zone 701, the medium density zones 702, 704 or the edge zones 703, 705. max , dY max , and Φ max can be about 500 μm or less, about 100 μm to 500 μm, for example, about 250 μm.

[0060] The flow diverters described herein can incorporate radiopaque marker receptacles 770 (see FIG. 1B) on one or more of the edge features and / or features located thereon. For example, a first set of one or more receptacles 770a can be located on the proximal and distal ends of the flow diverter, and a second set of one or more receptacles 770b can be located, for example, on either side of the intermediate flow diversion zone 701 to identify the length Lc. Receptacles 770a can be located on the most distal and most proximal ends, while receptacles 770b can be located in the valleys of the intermediate flow diversion zone 701 to identify the tightest coverage. Radiopaque material can be pressed into the receptacles 770 to allow the edges and zones of the flow diverter 700 to be visible under fluoroscopy. For example, radiopaque markers can be placed in recesses 770b on either side of intermediate zone 701 to allow a user to verify and / or confirm that intermediate zone 701 with approximately 30% material coverage is located across the neck of the aneurysm prior to performing procedural steps. The placement of recesses 770 can vary, some of which are shown in FIG. 1B as examples and are not intended to be limiting, as recesses 770 can be placed in any of a variety of locations depending on which portion of the flow diverter is desired to be visualized. At least one of the proximal end zone, intermediate zone, and distal end zone can include at least one radiopaque marker.

[0061] The flow diverter 700 can be designed to retract at least partially back into the sheath some distance during the deployment process. As described in more detail below with reference to Figures 8A-8C and 11C-11D, the flow diverter 700 can be deployed using a flow diverter delivery system 800 having an inner core member 820 and an outer restraining sleeve 810. The flow diverter 700 is attached to the inner core member 820, and the outer restraining sleeve 810 can be retracted a predetermined amount to partially deploy the flow diverter 700 (see Figure 8C). The design of the flow diverter 700 allows the user to pull back the restraining sleeve 810 proximally to partially deploy a portion of the flow diverter, and then re-advance the sleeve distally to reposition the distal end 707 of the flow diverter 700.

[0062] The cut pattern of the flow diverter 700 determines whether the flow diverter can be resheathed. If the pattern includes features that pop open beyond the inner diameter of the outer restraining sleeve 810, the flow diverter generally cannot be resheathed after being partially deployed. However, the flow diverters described herein can incorporate features (see rails 775 in FIG. 1E) that ensure that the flow diverter 700 remains within a particular outer diameter that can be received within the restraining sleeve even after being partially deployed.

[0063] The flow diverter of Figures 1A-1C has bridges 752 connecting a valley 753 of a first cell 750 to a peak 757 of a cell 750 in the same row 765 of an adjacent ring 760. However, these peak-valley connections may skip a ring 760 such that these peak-valley bridges alternate. The bridges 752 connecting the struts 751 near the edges of the cells 750 may also alternate with respect to the ring. In the embodiment of the flow diverter of Figures 1D-1F, some bridges 752 connecting the struts 751 near the edges of the cells do not alternate with respect to the ring. Instead, these bridges 752 form a continuous rail 755 that extends the axial length of the flow diverter 700. The rails 755 may form a line that passes through at least three cells, at least four cells, at least five cells, at least six cells, at least seven cells, or at least eight cells to connect radially adjacent hinges (or central curves). The lines can connect between 3 and 8 cells, or between about 4 and 6 cells. The connected cells can be in the middle zone, the medium density zone, or the end zone. The lines connecting radially adjacent hinges can be in the proximal and distal zones and pass through fewer cells than in the lines connecting radially adjacent hinges in the middle zone. The rails 775 can be in one or both corresponding zones 702, 703 near the distal end 707 of the flow diverter 700 but not in the zones 704, 705 near the proximal end 709 of the flow diverter 700 such that the flow diverter 700 has an asymmetry between its distal end 707 and proximal end 709. The presence of rails 775 in zones 702 and / or 703 near the distal end 707 of the flow diverter 700 is configured to allow the restraining sleeve 810 to be retracted and re-sheathed even after zones 702, 703 have been partially deployed and at least a portion of the intermediate zone 701 has been exposed.In yet another embodiment, these additional axial rails 775 may be incorporated into one or more other zones (e.g., zones 703, 702, 701, 704, and 705) along the length of the device so that the flow diverter 700 can be resheathed over most of the fully deployed length of the flow diverter 700. If more flexibility is desired than resheathing ability, in another embodiment, the axial rails 775 may extend at one end region 703 of the flow diverter 700 rather than two or more regions of the flow diverter 700. The axial rails 775 are shown extending between the peak-valley portions of the cells 750. Other axial features may be added at other locations of the cells 750, such as between the struts. When the flow diverter 700 is deployed in a curved configuration (a phenomenon known as “fish-scaling” in reference to open-cell stent structures), axial peak-valley rails 755 or other axial inter-strut features added between ring portions 760 may limit penetration of the features into the lumen or aneurysm space.

[0064] The embodiment shown in Figures 1A-1F has a cut pattern that provides a desired material coverage when deployed within a vessel, which can (but need not) vary along the axial length of the flow diverter. Figures 4A-4C illustrate a flow diverter 700 constructed from two laser cut, non-braided tubular members or tubes 706, 708 that provide a desired material coverage depending on how the flow diverter is deployed within a vessel and overlap can provide enhanced material coverage along the length of the flow diverter 700. Each of the two tubes 706, 708 may have a density of 15% respectively when deployed and may have a total material density of 30% when assembled together. Two tubes 706, 708 may be assembled in an staggered overlapping manner to form an overlapping region having a first density (e.g., 30% material coverage and 70% porosity) and each end of the staggered tubes 706, 708 having a second, lower density (e.g., 15% material coverage and 85% porosity). The two tubes 706, 708 may be fastened together by fastening features incorporated into the laser cut pattern. For example, as shown in FIG. 4A, one tube 706 may have one or more holes or elongated slots 710 laser cut into the tube 706 at one or both ends, and the second tube 708 may have one or more corresponding tabs 712 that protrude into and lie flat in the slots 710. The two tubes 706, 708 are assembled such that the tab 712 is inserted into the slot 710 and then the tubes 706, 708 slide against each other to fasten the two tubes 706, 708 together. In a different case, as can be seen in Fig. 4B, the slot 710 may have an 'L' shape such that the two tubes 706, 708 can be rotated to fasten the two tubes 706, 708 against each other to fasten them together. Alternately, as can be seen in Fig. 4C, the tab 712 may be pushed through the slot 710 and bent to fasten it in place.The tabs 712 may be over the slots in the inner tube 708 and outer tube 706 or vice versa.

[0065] 5A-5B illustrate another fastening mechanism for a flow diverter 700 consisting of two laser cut tubes 706, 708. Both tubes 706, 708 can be laser cut to include holes or elongated slots 710 at one or both ends in corresponding locations. The two tubes 706, 708 are assembled, one inside the other, with their respective holes 710a, 710b aligned. A disk 716 made from a malleable material is pressed into the holes 710a, 710b to fasten the tubes 706, 708 together. The disk 716 can be slightly tapered (i.e., from top to bottom as shown in FIG. 5A) and sized such that when the disk 716 is pressed into position, it deforms to fill the holes 710a, 710b and is held tightly in position. The disk 716 may be a radiopaque malleable material such as gold, gold alloy or tungsten so that it can also function as a radiopaque marker for the fastening mechanism and implant.

[0066] FIG. 6A illustrates another embodiment of a flow diverter 700 comprised of two laser cut tubes 706, 708. One tube 706 is constructed to provide structural integrity to the flow diverter, for example, to provide sufficient wall apposition and anchoring, such as by wall thickness and / or strut width. The other laser cut tube 708 is constructed to provide 30% material coverage, with a very fine strut pattern and a thin wall thickness. The thinner cut tube 708 may be a porous material such as a very fine wire braided tube, expanded (or stretched) PTFE tube, as seen in FIG. 6B. Also, the tube 708 with the finer strut pattern may be shorter than the tube 706 with the larger strut structure. In another embodiment, as illustrated in FIG. 6B, the two tubes 706, 708 may be the same length and the tubes 706, 708 may substantially overlap each other.

[0067] These multi-layered flow diverter implants 700 utilize the stent layer of the tube 706 structure to provide precise placement and anchoring, while the thinner stent layer of the tube 708 provides higher material coverage to divert blood away from the blocked aneurysm. The larger diameter access systems described herein allow for delivery of these multi-layered devices that are not possible with current microcatheter delivery methods, which have smaller inner diameters (e.g., 0.027 inches) that cannot accommodate the flow diverter alone, much less the restraining sleeve along with the flow diverter, as described above, which are laser cut.

[0068] The flow diverter 700 may also be formed from a variety of materials and structures along its length. For example, as shown in FIG. 7, the flow diverter 700 is formed from two laser cut bands 718, 722 at either end of the device. A thinner structure such as a braided wire tube 720 can be placed between the two laser cut bands 718, 722 and connected to the laser cut bands to form a multi-part implant. The braided wire tube 720 can be combined with the laser cut bands 718, 722 to bond with the bands. This composite or hybrid structure provides two end anchors to the flow diverter 700 with higher material coverage across the aneurysm.

[0069] The flow diverter implants described herein may be self-expanding tubes or cut tube elements to achieve a designed pattern. Any of the cut tube elements of the flow diverters described herein may be self-expanding members or one or more laser cut tubes of Nitinol. The tubes may be Nitinol or another elastic material that allows for the desired mechanical properties of the self-expanding device.

[0070] Tubes or cut tube components can be cut to achieve the desired cut pattern, such as by laser, machining, photolithographic photoetching, or other chemical etching. Instead of cutting structures from tubing on a cylinder, they can be cut or assembled into planar structures as flat patterns, and then compressed or otherwise wrapped or rolled up into a helical or cylindrical structure for delivery, and deployed in situ into a partially cylindrical shape, a cylindrical shape, or a partially or fully overlapping roll structure. In this embodiment, features may include a ratchet feature or latching flow diverter in the deployed configuration. Cut tubes can also be fabricated by deposition in a tube or flat pattern, which is then rolled up.

[0071] The cut tube may undergo a finishing process, such as electropolishing or heat setting, to achieve the desired mechanical and dimensional properties. In some embodiments, the flow diverter can be heat formed to have a flare at one or both ends 707, 709 to aid in anchoring the flow diverter against the vessel wall during deployment.

[0072] Other materials and manufacturing methods can be utilized to fabricate the flow diverter as described herein. Alternately, any of the above flow diverter implants can be a balloon mounted laser cut stent that can be fabricated from one or more laser cut stainless steel, cobalt chrome alloy, or other materials known for use in balloon deployable stents. The flow diverter can be fabricated from a tubing material that includes a radiopaque material in addition to the typical composition of superelastic nickel titanium. For example, the radiopaque material can include platinum, tantalum, tungsten, or gold. The radiopaque material can be homogenously incorporated into the material in an advantageous ratio, or the material can be configured as a laminate that includes one or more layers of radiopaque material in addition to one or more layers of nickel titanium, or can be coated onto the surface of the nickel titanium.

[0073] The systems described herein may be used with larger-bore access systems, and therefore, if desired, the flow diverter may be a braided wire type flow diverter, in which case the braiding parameters of the braided wire type flow diverter may be modified to improve performance. For example, the wire size and / or number of wires may be increased without limiting the design to being deliverable through a 0.21 inch or 0.27 inch inner diameter microcatheter delivery system as required for current flow diverters. An example of a current braided flow diverter is the Pipeline Embolization System with 48 wires x 30 microns (0.0013 inch). The increased wire size would not be compatible with a 0.027 inch inner diameter microcatheter. Flow diverters with a larger number of braided wires have smaller wire sizes, for example, the Surpass Evolve has 64 braided wires with 0.011 inch wires. Again, the increased wire size would not be compatible with a 0.027 inch inner diameter microcatheter. In one embodiment, the flow diverter 700 is a braided wire flow diverter constructed from 48 or up to 96 or more wires with 35-55 μm diameter strands. These thicker gauge and / or higher number of wire strands braided flow diverters may have stronger radial forces and faster opening deployment than currently available flow diverters, making them easier to deploy and reducing current issues with braided flow diverters such as flattening and ribboning during deployment.

[0074] The flow diverters described herein may have anti-thrombosis specific surface modifications or coatings, such as, for example, heparin coatings, hydrophilic polymer coatings such as phosphorylcholine and phenox hydrophilic polymers, albumin, or fibrin.

[0075] Flow Diverter Delivery System

[0076] Flow diverters are conventionally attached to an inner delivery core wire and delivered through a microcatheter having an inner diameter of 0.027 inch (0.7 mm). In order to be delivered through such smaller sized delivery systems while still providing the desired wall coverage (approximately 30%) when deployed in vessels up to 5.0 mm in diameter, flow diverters conventionally have a braided wire construction.

[0077] Delivery of conventional braided flow diverters typically occurs in multiple steps. First, a microcatheter is inserted into the vasculature and advanced over a guidewire to a location past the desired aneurysm site. The microcatheter tip is often placed too far distal to the final target site due to imprecision in delivery of braided flow diverters. Once the microcatheter is positioned over the desired aneurysm, the guidewire is removed. The braided flow diverter is then inserted into the proximal end of the microcatheter using an introducer tube. The flow diverter is pre-attached to a delivery corewire with features that restrain the flow diverter in a contracted configuration and remain longitudinally attached on the delivery corewire. For example, the corewire may have a PTFE sleeve that covers and restrains the braided flow diverter at both ends. The corewire often has a distal flexible tip that extends up to 15 mm beyond the distal end of the flow diverter. This means that the distal tip needs to be placed at least 15 mm beyond the treatment site, and the more distally the microcatheter is placed, the greater the distance required to properly position the flow diverter, potentially resulting in complications. The core wire is used to push the flow diverter to the end of the microcatheter. The microcatheter is then retracted to expose the braid, which due to its material properties and construction, begins to pop open. The distal end does not reach a fully open diameter until several millimeters of the braid are exposed, due to the nature of the braided construction. To achieve adequate placement of the flow diverter against the vessel wall, the user is often required to push the microcatheter while pulling on the core to "push" the braid until it is fully open, which is highly desirable to achieve the intended therapeutic effect. This push and pull technique is yet another potential source of clinical complexity and time for conventional braided flow diverters in terms of procedural and placement inaccuracies.Braids, by their very nature, shorten significantly upon deployment, making precise placement more difficult. Often, flow diverters are delivered distally to the desired site and then partially deployed and "pulled back" to position themselves across the target site. Both the distal placement and retraction steps of the microcatheter carry the risk of vascular injury and vascular perforation, both of which have significant clinical sequelae.

[0078] In many flow diverter delivery systems, the delivery corewire has features that restrain the braided wire end. Following deployment of the flow diverter, the microcatheter must be re-advanced through the braid so that it is proximal enough to the implant and covers the corewire features so that the delivery corewire is not obstructed by the flow diverter that has just been deployed. Each of these steps potentially obstructs the flow diverter, adding to procedure time and a potential source of clinical complications due to additional catheter manipulation.

[0079] The flow diverters described herein are larger in diameter and can be delivered by a flow diverter delivery system configured for use with a large bore access system as compared to traditional braided flow diverters. The delivery system described herein can be used with any of the flow diverters described above, including laser cut, braided, or woven flow diverters or combinations thereof.

[0080] 8A-8C illustrate a flow diverter delivery system 800 having an outer restraining sleeve 810 and an inner core member 820 having an elongated shaft 823. The inner core member 820 can have an internal lumen (not shown) sized to accommodate a guidewire. The internal lumen can be a single central lumen, allowing the flow diverter 700 and flow diverter delivery system 800 to be delivered over a guidewire. The shaft 823 of the inner core member 820 has a recessed section 825 of reduced diameter near the distal end region sized to accommodate the flow diverter 700. As shown in FIG. 8B, the flow diverter 700 is positioned in the recess 825 of the inner core member 820 and is held in this position by the outer restraining sleeve 810. The flow diverter 700 is held within the recessed section 825 by the inner core member 820 and deployed by deployment when the restraining sleeve 810 is retracted proximally. The inner core member 820 may include a gripping feature 829 located at the proximal end of the recessed section 825 configured to prevent the flow diverter 700 from being pulled back over the shaft 823 of the inner core member 820 when the restraining sleeve 810 is withdrawn during deployment of the flow diverter. The gripping feature 829 may be of a high friction component, such as a thin walled silicone or other elastomeric tube.

[0081] The material of the shaft 823 of the inner core member 820 is selected to maintain axial integrity during deployment of the flow diverter 700. For example, the shaft 823 and recessed section 825 may be constructed from Pebax, such as Pebax 72D. The shaft 823 and / or recessed section 825 may be braid reinforced, coil reinforced, or reinforced to provide axial stiffness.

[0082] The length of the outer restraining sleeve 810 is shorter than the inner core member 820 (see FIG. 8C) by a length that allows the flow diverter 700 to be fully deployed when the restraining sleeve 810 is retracted relative to the inner core member 820. The restraining sleeve 810 is configured so that it can be easily retracted without pulling the flow diverter with it. For example, the restraining sleeve 810 can be configured with multiple layers including a low friction inner liner such as PTFE or FEP. The restraining sleeve 810 can be braided or coil reinforced to resist stretching during retraction. The restraining sleeve 810 can also have an outer hydrophilic coating layer on the distal portion to improve delivery through larger bore catheters, as described in more detail below.

[0083] 8A, the inner core member 820 can include a distal tip region 827 located distal to the recessed region 825. The distal tip region 827 of the inner core member 820 is tapered and has a flexibility, shape, taper length and taper angle configured for atraumatic delivery of the delivery system 800 to a blood vessel in the brain with or without a guidewire. Its structure, materials and configuration can be similar to the tapered tip 346 of the catheter advancement element 300 described below with respect to the access system 100 and in U.S. Patent No. 11,065,019, which is incorporated herein by reference. For example, the distal tip region 827 can have two radiopaque markers 844a, 844b configured to outline a tapered section. A first radiopaque marker 844a can identify the distal most end of the inner core member 820 and a second radiopaque marker 844b can identify the area of ​​maximum outer diameter of the taper for optimal delivery purposes to the outer constraining sleeve 810. The outer diameter of the inner core member 820 just proximal to the taper can be sized to be a smooth fit against the inner diameter of the constraining sleeve 810 to provide a smooth tip for the flow diverter delivery system to be advanced within the vasculature with or without a guidewire.

[0084] The dimensions of the flow diverter 700 and flow diverter delivery system 800 are sized to be deliverable through a larger-bore access system. As described above, the flow diverter 700 may be a cut tube structure with cells 750 arranged in peak-valley connected rings 760. When deployed, the flow diverter has dense material coverage (e.g., 30% coverage or 70% porosity) due to the closely stacked arrangement of cells 750. The flow diverter 700 can utilize the constraints of the larger diameter access system to achieve this dense material coverage. For example, for a distal access system 100 having an access catheter 200 with an inner diameter (ID) of 0.088 inches, the outer restraining sleeve 810 may have an outer diameter (OD) of approximately 0.082 inches, leaving an annular clearance of 0.003 inches (ID / OD difference of 0.006 inches) for optimal advancement of the flow diverter delivery system 800 through the access catheter 200. In this example, the inner diameter of the outer restraining sleeve 810 is approximately 0.070 inches. The contracted flow diverter 700 may have an OD of approximately 0.064 inches to easily slide through this outer restraining sleeve 810. The inner core member 820 may have an OD of approximately 0.064 inches, with a recessed section 825 of smaller ID depending on the wall thickness of the flow diverter 700. If the wall thickness of the cut tube flow diverter 700 is approximately 0.005 inches, then the recessed section 825 has an OD of approximately 0.054 inches.

[0085] Larger access systems allow for alternative delivery methods. For example, rather than first placing a microcatheter across the aneurysm, removing the guidewire, and then pushing the flow diverter into place as with conventional flow diverter delivery systems, the flow diverter 700 described herein can be pre-mounted onto a delivery system 800 with a restraining sleeve 810 and delivered to the site via a larger delivery system (e.g., 0.087" to 0.126" ID). The guidewire, flow diverter 700, and inner core member 820 can all be pre-mounted onto one system rather than replacing the guidewire with the flow diverter and inner core member as with conventional systems.

[0086] In some embodiments, the access catheter 200 acts as the restraining sleeve of the flow diverter delivery system 800 instead of a separate restraining sleeve 810. Similar to how current flow diverters can be introduced into a pre-positioned microcatheter across the desired site, the flow diverter 700 can be attached to the inner core member 820, introduced into the access system 100 via a separate introducer component, and pushed by advancing the inner core member 820 to the desired aneurysm treatment site. In this example, the access catheter 200 can be pre-positioned across the desired site. Once the flow diverter 700 is positioned at its desired site, the access catheter 200 can be pulled back while holding the inner core member 820 in place to deploy the flow diverter 700. In this example, there is one "layer" of the catheter removed (i.e., the restraining sleeve 810). This allows for a larger inner diameter for the same size flow diverter. A flow diverter with an outer diameter of 0.064 inches can be delivered using an access catheter with an inner diameter of 0.070 inches and an outer diameter of 0.082 inches (vs. ID 0.088 and OD 0.100 inches in the previous example).

[0087] Access System The flow diverters and flow diverter delivery systems described above can be delivered using an access system and / or access catheter with suitable large bore internal diameter and capability to reach the intended aneurysm treatment site. Current access devices, i.e., guidewires and / or guide sheaths, are used to access the anatomical structures of the cerebral vasculature but have limitations.

[0088] Guide catheters or guide sheaths are used to guide interventional devices from an arterial access site, typically the femoral artery, to the target anatomical structure. The length of the guide is determined by the distance between the access site and the desired location of the guide distal tip. Interventional devices such as guidewires, microcatheters, and intermediate catheters used for partial selective guidance are inserted through the guide and advanced to the target site. Often, the devices are used in a coaxial fashion, i.e., with an inner guidewire of an inner microcatheter inside an intermediate catheter, advanced as an assembly to the target site in stages, with the inner, most atraumatic element advancing distally first and providing support for the advancement of the outer elements. The length of each element of the coaxial assembly takes into account the length of the guide, the length of the catheter's proximal connector, and the length it needs to extend from the distal end.

[0089] A typical triaxial system, such as for the delivery of flow diverters, stents, stent retrieval devices, and other typical interventional devices, requires a series of overlapping catheters, each with its own rotating hemostatic valve (RHV) at the proximal end. For example, a guidewire can be inserted through a Penumbra VELOCITY microcatheter with a first proximal RHV, which can be inserted through a Penumbra ACE68 with a second proximal RHV, which can be inserted through a Penumbra NEURONMAX 088 access catheter with a third proximal RHV placed in the high carotid artery via the femoral region. Maintaining a coaxial relationship between these catheters can be technically challenging. The three RHVs require constant adjustments by two hands, or more commonly, four hands (i.e., two operators). Additionally, the working area of ​​a typical triaxial system for intracranial and intracerebral device delivery can require a working area of ​​3 to 5 feet at the operating table base. Time is required to access the treatment site with a three-axis system.

[0090] It is also difficult to reach intracranial and cerebral vessels in a rapid and atraumatic manner with larger bore access catheters and sheaths. Both the length and diameter of current systems pose limitations to delivery systems for intravascular scaffolding devices such as stents or flow diverters, which limit the safety, speed, and accuracy of delivering such devices. There is a need for device systems and methods with larger lumen sizes and / or shorter lengths that allow rapid access of distal intracranial and cerebral vessels.

[0091] The access systems and methods described herein allow for the safe and rapid placement of large interventional devices, such as flow diverter delivery systems, at aneurysm sites in intracranial or cerebral arteries. Additionally, the extreme flexibility and deliverability of the distal access catheter systems described herein allows the catheters to take the shape of curved anatomical structures rather than exerting a straightening force creating a new anatomical structure. The distal access catheter systems described herein can pass through tortuous loops while retaining the original curvature of the anatomical structure, thereby creating a safe conduit through the cerebral vasculature that retains the original curvature of the anatomical structure for passage of other catheters (e.g., interventional device delivery catheters) while reducing the risk of vessel straightening. Catheters passing through the conduit do not need to have the same degree of flexibility and deliverability that would result in the straightening, kinking, or bending of the anterior circulation if they were delivered directly to the same anatomical structure rather than through a conduit.

[0092] Provided herein is an access system that includes a catheter advancement element having a tapered distal end region with flexibility, shape, and taper length configured for intact delivery to blood vessels in the brain. This has not been achieved with prior catheter systems because prior catheter systems have inadequate flexibility, are made of inadequate materials, or have inadequate shapes and / or taper lengths that could be misdirected, snag, or perforate blood vessels if greater force is applied. Unlike these prior catheter systems, the catheter systems described herein include a catheter advancement element that can be safely guided into the brain anatomy and have an internal lumen that allows a corresponding large bore catheter (i.e., flow diverter delivery system) to be delivered to a distal site. The catheter systems described herein aid in locating vascular occlusions in a novel manner as provided herein. These and other features are described in detail herein.

[0093] 9A-9B illustrate an embodiment of a distal access system 100 including a device for accessing and treating an intracranial or cerebral aneurysm, for example by deploying a flow diverter. FIG. 9A is an exploded view of an embodiment of the access catheter system, and FIG. 9B is an assembled view of the catheter system of FIG. 9A. FIG. 10A is a detailed view of the catheter advancement element of FIG. 9A taken along circle CC of FIG. 9A. FIG. 10B is a detailed view of the catheter advancement element with a guidewire 500 in lumen 368 such that the distal end of the guidewire 500 extends distal to the distal opening 326 of lumen 368. The distal access system 100 can provide quick and easy access to distal target anatomies, particularly tortuous anatomies of the intracranial or cerebral vasculature. The system 100 can be a single operator system such that each of the components and systems can be delivered and used together by a single operator via a single point of manipulation requiring minimal hand movement. As described in more detail below, all wire and catheter manipulation may be accomplished at a single rotating hemostatic valve (RHV) or at the access points of more than a single RHV co-located in the same device.

[0094] The system 100 can include one or more catheter systems 150, each having a catheter 200 and a catheter advancement element 300. The catheter system 150 is configured to be advanced through an access guide sheath 400. The catheter 200 is configured to be received through the guide sheath 400 and is designed to have very good deliverability. The catheter 200 may, but need not, be a distal access catheter having a distal tubular component that couples to a proximal control element of smaller outer diameter. The distal tubular component, which is coaxial with the lumen of the guide sheath 400, provides a step-up in inner diameter within the conduit. The catheter need not include a proximal control element, but instead may be a conventional full-length catheter having a constant diameter.

[0095] The catheter 200 can be delivered using a catheter advancement element 300 that inserts through the lumen 223 of the catheter 200. The flexibility and deliverability of the distal access catheter 200 allows the catheter 200 to take the shape of curved anatomy and avoid exerting straightening forces that would create new anatomy. The distal access catheter 200 has this capability even with the catheter advancement element 300 extending through its lumen. In this manner, the flexibility and deliverability of the catheter advancement element 300 is equal to or better than that of the distal lumen portion 222 of the distal access catheter 200, both of which are configured to reach the middle cerebral artery (MCA) circulation without stretching the curves of the anatomy along the way.

[0096] 9A-9B, the distal access system 100 can include an access guide sheath 400 having a body 402 through which a working lumen extends from a proximal hemostatic valve 434 connecting with a proximal end region 403 of the body 402 to a distal opening 408 at the distal end region. The working lumen is configured to receive a catheter 200 therethrough such that the distal end of the catheter 200 can extend through the distal opening 408 and beyond the distal end of the sheath 400. The guide sheath 400 can be used to deliver the catheters described herein, as well as any of a variety of working devices known in the art. For example, the working device can be configured for treatment of a thrombus and can include a large diameter catheter for delivery of a flow diverter.

[0097] The sheath body 402 can extend from a rotary hemostatic valve (RHV) 434 at the proximal furcation or proximal end region 403 to a distal end opening 408 of the body 402. The proximal RHV 434 can include one or more lumens 412 formed in the connector body to connect to the working lumen of the body 402 of the guide sheath 400. The working lumen can receive the catheter 200 and / or any of a variety of working devices for delivery to the target anatomical structure. The RHV 434 can be constructed from thick wall polymeric tubing or reinforced polymeric tubing. The RHV 434 allows for the introduction of devices through the guide sheath 400 into the vasculature while avoiding or minimizing blood loss and preventing the introduction of air in the guide sheath. The RHV 434 can be integral to the guide sheath or the guide sheath 400 can terminate at its proximal end with a female Luer adapter to which another hemostatic valve element, such as a passive seal valve, a Tuohy-Borst valve, or an RHV, can be attached. The RHV 434 can have an adjustable opening that opens wide enough to allow removal of a device having a thrombus attached to the distal opening 408 without dislodging the thrombus from the RHV 434 during removal. In another embodiment, the RHV 434 avoids dislodging the thrombus in the RHV 434, such as when removing the device from the sheath 400. The RHV 434 can be a dual RHV or a multi-headed RHV.

[0098] A contrast agent can be injected through the guide sheath 400 to make the occlusion site visible by angiogram. For example, the guide sheath 400 can be positioned so that it is at least partially located within the carotid artery. Once in position, the contrast agent can be injected through the sheath 400. The contrast agent can also be injected through one or more catheters inserted through the guide sheath 400. A baseline angiogram can be obtained, for example in superior / posterior and / or lateral views, prior to insertion of the device to assess the occlusion site by injection of contrast agent through the sheath 400 with fluoroscopic visualization. Fluoroscopic visualization can be continued while advancing the catheter system, and subsequent angiograms are obtained periodically to assess recanalization. The baseline angiogram images can be superimposed such that the vasculature and / or the occlusion site are visible while the catheter is advanced, as with digital subtraction angiograms.

[0099] Once the catheter system 150 has been advanced to a predetermined location (placement is described in more detail below), the catheter advancement element 300 can be retracted and removed from the system. In some embodiments, the catheter 200 can be used as a support catheter to deliver a stent or flow diverter to a treatment site (e.g., a site within the carotid or intracerebral arteries), as described elsewhere herein.

[0100] In one embodiment, the guide sheath 400 includes one or more radiopaque markers 411. The radiopaque markers 411 can be positioned near the distal end opening 408. For example, a pair of radiopaque bands can be positioned. The radiopaque markers 411 or any of the markers of the components of the system can be crimped, painted, embedded, or otherwise positioned in or on the body. In some embodiments, the radiopaque markers include barium polymer, tungsten polymer blend, tungsten-filled, or platinum-filled markers that maintain the flexibility of the device and improve resistance to transitions and bending along the length of the component. In some embodiments, the radiopaque markers are tungsten-filled PEBAX or polyurethane heat welded to the components.

[0101] The guide sheath markers 411 are illustrated as rings circumferentially around one or more regions of the body 402. However, the markers 411 can have other shapes or create various patterns that orient the operator with respect to the location of the distal opening 408 within the vessel. Thus, the operator can visualize the location of the distal opening 408 under fluoroscopy to ensure that the distal opening 408 is advanced toward the target anatomical structure to which the catheter 200 is to be delivered. For example, the distal opening radiopaque marker 411 allows the operator to rotate the body 402 of the guide sheath 400 at an anatomical access point, such as the patient's groin, such that the distal opening provides access to the ICA with subsequent working devices, such as a catheter and wire advanced to the ICA. In some embodiments, the radiopaque marker 411 comprises platinum, gold, tantalum, tungsten, or other material visible under fluoroscopy. Any of the various elements of the systems described herein may incorporate radiopaque markers.

[0102] 9A-9B, the catheter 200 can include a stiffer, bend-resistant proximal extension or a relatively flexible distal lumen portion 222 that connects to the proximal control element 230. The term "control element" as used herein can refer to a proximal region configured to allow a user to exert a pushing motion in a distal direction as well as a pulling motion in a proximal direction. The control elements described herein can be spines, tethers, push wires, push tubes, or other elements having any of a variety of shapes. The proximal control element 230 can be a hollow or tubular element. Also, the proximal control element 230 can be solid and can have no lumen, such as a solid rod, ribbon, or other solid wire-type element. Generally, the proximal control element as described herein is configured to move its respective component (which may be attached or integral with it) in a bidirectional manner through a lumen.

[0103] A single lumen 223 extends through lumen portion 222 between the proximal and distal ends of lumen portion 222 (lumen 223 is visible in FIG. 9B). In some embodiments, a proximal opening 242 into lumen 223 can be located near where proximal control element 230 joins distal lumen portion 222. In other embodiments, proximal opening 242 into lumen 223 is at the proximal end region of catheter 200. Distal opening 231 from lumen 223 can be located at or near the distal-most end 215 of lumen portion 222. Lumen 223 of catheter 200 can have a first inner diameter and the working lumen of guide sheath 400 can have a second, larger inner diameter. Upon insertion of the catheter 200 through the working lumen of the sheath 400, the lumen 223 of the catheter 200 is configured to be in fluid communication with the working lumen of the sheath 400, allowing for the flow of liquid into and / or out of the system 100, for example, by application of suction from a vacuum connected to the system 100 at the proximal end. The combination of the sheath 400 and catheter 200 may be in continuous communication with the blood flow at the proximal end upon advancement and retraction of the catheter 200.

[0104] The distal lumen portion 222 of the catheter 200 may have one or more radiopaque markers 224. A first radiopaque marker 244a may be located near the most distal end 215 to aid in navigation to and proper placement at the most distal end 215 under fluoroscopy. In addition, the proximal region of the catheter 200 may have one or more proximal radiopaque markers 224b to allow visualization of the overlap region 348, as the relationship between the radiopaque marker 411 on the guide sheath 400 and the radiopaque marker 224b on the catheter 200. The proximal region of the catheter 200 may also have one or more radiopaque markers, for example, near the proximal opening 242 to the single lumen 223 of the catheter 200, as described in more detail below. In one embodiment, the two radiopaque markers (marker 224a near the most distal end 215 and marker 224b more proximal) can be distinct to minimize clutter in the fluoroscopic image, for example, the catheter proximal marker 224b can be a single band and the marker 411 on the guide sheath 400 can be a dual band, and any markers on the working device delivered through the distal access system can be different types of bands or marks. The radiopaque markers 224 on the distal lumen portion 222, especially those near the distal end region that navigates through extremely tortuous anatomy, can be relatively flexible so as not to affect the overall flexibility of the distal lumen portion 222 near the distal end region. The radiopaque markers 224 can be tungsten-filled or platinum-filled markers, which are relatively flexible compared to other types of radiopaque markers used in devices where flexibility is not a priority. In some embodiments, the radiopaque marker can be a band of tungsten-filled PEBAX having a hardness of Shore A 35D.

[0105] The proximal control element 230 may include one or more markers 232 to indicate the overlap between the distal lumen portion 222 of the catheter 200 and the sheath body 402, as well as the overlap between the distal lumen portion 222 of the catheter 200 and other interventional devices that may extend through the distal lumen portion 222. At least a first mark may be an RHV proximal marker, positioned at a distal-most position with a minimum overlap length required for the catheter 200 to form a seal between the catheter 200 and the working lumen when the mark is aligned with the sheath proximal hemostatic valve 434 during insertion of the catheter 200 through the guide sheath 400. At least a second marker 232 may be a Fluoro-saver marker, positioned on the control element 230 and may be positioned away from the distal-most end 215 of the distal lumen portion 222. In some embodiments, marker 232 can be positioned about 100 cm from the distal-most end 215 of distal lumen portion 222. One or more markers can be positioned such that they are visible to an operator outside the patient (and outside of guide sheath 400) during use, and one or more markers can be visible to an operator inside the patient (and inside or beyond the distal end of guide sheath 400) during use, as visualized under fluoroscopy.

[0106] 9A-9B is shorter than full length and includes a rapid exchange opening 242 to the distal lumen portion 222. The catheter 200 can also be a full-length catheter with the lumen terminating between the distal and proximal openings, with the proximal opening configured to be external to the sheath hub and external to the patient.

[0107] 9A-9B and 10A, the catheter advancement element 300 can include a non-stretching, flexible body 360 and a proximal portion 366. The catheter advancement element 300 and catheter 200 described herein can be configured for rapid exchange or over-the-wire. For example, the flexible elongate body 360 can be a tubular portion that extends the entire length of the catheter advancement element 300 and can have a proximal opening from a lumen 368 of the flexible elongate body 360 that is configured to extend outside the patient's body during use. In another aspect, the tubular portion can have a proximal opening that is positioned to be located inside the patient's body during use. The proximal portion 366 can be a proximal element that connects to the distal tubular portion 360 and its location extends proximally. The proximal opening from the tubular portion 360 can be located near where the proximal element 366 joins with the tubular portion 360. In another embodiment, the proximal portion 366 can be an extension of the tubular portion 360 having a length that extends to a proximal opening near the proximal end of the catheter advancement element 300 (i.e., outside the patient's body). A luer 364 can be coupled to the proximal portion 366 at the proximal end region so that a tool such as a guidewire can be advanced through the lumen 368 of the catheter advancement element 300. A syringe or other component can be connected to the luer to draw a vacuum and / or inject liquids through the lumen 368. A syringe connected to the luer can also be used to close off the lumen of the catheter advancement element 300, maximizing the piston effect described elsewhere herein.

[0108] The configuration of the proximal portion 366 can vary. In some embodiments, the proximal portion 366 is simply a proximal extension of the flexible elongate body 360 that does not vary significantly in terms of structure, but rather in terms of flexibility. For example, the proximal portion 366 transitions from a very flexible distal region of the catheter advancement element 300 toward a less flexible proximal region of the catheter advancement element 300. In some embodiments, the proximal portion 366 can provide a relatively stiff proximal end suitable for manipulating (e.g., advancing and retracting) the more distal region of the catheter advancement element relative to the anatomical structure and / or the outer catheter 200. The proximal portion 366 can be formed from a less flexible polymer than the flexible elongate body. The proximal portion 366 can be all polymer with no reinforcement, or the proximal portion 366 can be a reinforced polymer portion. Depending on whether the catheter advancement element 300 is being used with a full length catheter or with a catheter having only a short distal tubular section, the configuration of the proximal section 366 can vary. A catheter advancement element 300 used with a full length catheter does not need to rely on a proximal reinforcement section to advance the catheter system through the anatomy, but can instead rely on the proximal stiffness of the outer catheter. A catheter advancement element 300 used with a partially tubular outer catheter can benefit from a stiffer reinforcement section in its proximal end region to advance the system.

[0109] In some embodiments, the proximal portion 366 is a metal reinforced portion. The metal reinforced portion can be spaced apart from the distal end of the elongated body. For example, the metal reinforced portion can be about 50 cm from the distal end. The metal reinforced portion can have an inner diameter of about 0.021 inches and an outer diameter of about 0.027 inches. The metal reinforced portion can be a spine. The metal reinforced portion can be a hypotube. In other embodiments, the proximal portion 366 is a hypotube. The hypotube can be bare or coated with a polymer. In yet another embodiment, the proximal portion 366 can be a tubular polymer portion reinforced with a coiled ribbon or braid. The proximal portion 366 can have the same outer diameter as the flexible elongated body or a smaller outer diameter like the flexible elongated body.

[0110] The proximal portion 366 need not include a lumen. For example, the proximal portion 366 may be a solid rod, ribbon, or wire, and does not have a lumen extending therethrough that connects it to the tubular elongate body 360. Where the proximal portion 366 is described herein as having a lumen, it will be understood that the proximal portion 366 can also be solid and have no lumen. The proximal portion 366 is generally less flexible than the elongate body 360, and can transition to be more rigid toward the proximal-most end of the proximal portion 366. In this manner, the catheter advancement element 300 can have a very soft and flexible distal end region 346 that transitions proximally to a stiff proximal portion well suited for pushing and / or rotating the distal elongate body 360.

[0111] The elongate body 360 can be received within and extend through the lumen 223 of the distal lumen portion 222 of the catheter 200 (see FIG. 2B). The elongate body 360 or tubular portion can have an outer diameter. The outer diameter of the tubular portion can have at least one snug point. The at least one snug point provides a close fit between the distal lumen portion 222 and the elongate body 360 that minimizes the distal edge or lip of the distal end of the catheter 200, yet still allows movement relative to one another so that a user can achieve a desired advancement or retraction of the catheter advancement element 300 relative to the catheter 200 or the advancement element 300 relative to the catheter 200. The snug point allows movement between the catheters when a relatively small force is applied to avoid negative effects on use in a patient. The difference between the inner diameter of the catheter 200 and the outer diameter of the tubular portion at the snug point can be about 0.015 inches (0.381 mm) or less, or can be about 0.010 inches (0.254 mm) or less, for example, about 0.03 inches (0.0762 mm) to about 0.012 inches (0.3048 mm), preferably about 0.005 inches (0.127 mm) to about 0.010 inches (0.254 mm), and more preferably about 0.007 inches (0.1778 mm) to about 0.009 inches (0.2286 mm).

[0112] As described in more detail below, the catheter advancement element 300 can also include a distal end region 346 located distal to at least one snug point of the tubular portion. The distal end region 346 can have a length and a taper along at least a portion of the length. The distal end region 346 of the catheter advancement element 300 can extend beyond the distal end of the catheter 200, as shown in FIG. 9B. A proximal portion 366, or proximal extension, of the catheter advancement element 300 is connected to and extends proximally from the proximal end region of the elongated body. The proximal portion 366 can be less flexible than the elongated body 360 and can be configured to allow bidirectional movement of the elongated body 360 of the catheter advancement element 300 within the lumen portion 222 of the catheter 200, as well as for movement of the catheter system 100 as a whole. The elongated body 360 can be coaxially inserted through the lumen 223 inside the lumen 222. The outer diameter of at least one region of elongate body 360 can be sized to substantially fill at least a portion of the lumen of interior 223 of lumen 222 .

[0113] The overall length of the catheter advancement element 300 (e.g., from the proximal end to the distal-most tip) can vary, but is generally long enough to extend through the support catheter 200, as well as at least a distance beyond the distal end of the support catheter 200, while remaining outside the proximal end of the guide sheath 400 at least a proximal portion 366, and outside the patient's body. In some embodiments, the overall length of the catheter advancement element 300 is about 145 to about 150 cm, and has a working length, from the proximal tab or hub to the distal-most tip 325, of about 140 cm to about 145 cm. The elongate body 360 may have at least the same length as the lumen portion 222 of the catheter 200, but may be shorter than the lumen portion 222, so long as at least a minimum length of the elongate body 360 is inside the lumen portion 222 when the distal portion of the elongate body 360 extends distal to the distal end of the lumen portion 222 so as to form a snug point or area with the catheter. In some embodiments, this minimum length of the elongate body 360 that is inside the lumen portion 222 when the distal end region 346 is positioned in its optimally advanced configuration is at least about 5 cm, at least about 6 cm, at least about 7 cm, at least about 8 cm, at least about 9 cm, at least about 10 cm, at least about 11 cm, or at least about 12 cm, up to about 50 cm. In some embodiments, the shaft length of the distal lumen portion 222 can be from about 35 cm to about 75 cm, which can be shorter than the working length of the guide sheath, and the insertion length of the elongate body 360 can be at least about 45 cm, at least about 46 cm, at least about 47 cm, at least about 48 cm, at least about 48.5 cm, at least about 49 cm, at least about 49.5 cm, up to about 85 cm.

[0114] The length of the elongated body 360 allows the distal end of the elongated body 360 to reach target or occlusion sites within cerebral vasculature within segments of the internal carotid artery, including the neck (1C), petrous (2C), hiatus (3C), marine (4C), clinoid (5C), orbital (6C), and communicating (7C) segments of the internal carotid artery (ICA), as well as branches from these segments, including the middle cerebral artery (MCA), anterior cerebral artery (ACA), anterior temporal branch (ATB), and / or M1 or M2 segments of the posterior cerebral artery (PCA). The distal region of the elongated body 360 can reach these distal target locations while the proximal end region of the elongated body 360 remains below or proximal to the sharp bends along the push path. For example, the entry location of the catheter system can be in the femoral artery and the intended occlusion location can be distal to the right common carotid artery, such as in the M-segment of the right middle carotid artery. The proximal end region of the elongated body 360, which transitions to the proximal portion 366, can remain in the proximal vessel of highly tortuous anatomical structures such as the carotid siphon, right common carotid artery, brachiocephalic artery, aortic arch to brachiocephalic artery branch, and aortic arch, as they transition from the descending aorta. This avoids inserting the stiffer proximal portion 366 or following the aortic arch turn or the aortic arch to brachiocephalic artery branch turn, both of which can be very severe, as the material transition between the stiffer proximal portion 366 and the elongated body 360. The lengths described herein for the distal lumen portion can also be applied to the elongated body 360 of the catheter advancement element.

[0115] The proximal portion 366 can also vary in length. In some embodiments, the proximal portion 366 is about 90 cm to about 95 cm. The distal portion, which extends distally of the distal end of the lumen portion 222, can include a distal end region 346 that protrudes beyond the distal end of the lumen portion 222 during use of the catheter advancement element 300. As described in more detail below, the distal end region 346 of the elongate body 360 is configured to protrude distally from the distal end of the lumen portion 222 during advancement of the catheter 200 through the tortuous anatomy of the brain vasculature. The proximal portion 366, which is connected to and extends proximally therefrom, can be generally aligned side-by-side with the proximal control element 230 of the catheter 200. As described in more detail below, alignment between elongate body 360 and lumen portion 222 can be maintained during advancement of catheter 200 through tortuous anatomical structures to reach a desired point for treatment within a distal vessel, helping to prevent the distal end of catheter 200 from becoming caught in tortuous, branching vessels.

[0116] In some embodiments, the elongate body 360 can have a relatively uniform outer diameter extending along at least a portion of its length, with the distal end region 346 tapering away from the uniform outer diameter. The outer diameter of the elongate body 360 can also taper or step down in the outer diameter proximally, for example, near where the elongate body 360 joins or transitions to the proximal portion 366. The outer diameter of the elongate body 360 need not change near where the elongate body 360 joins or transitions to the proximal portion 366. In some embodiments, the region of relatively uniform outer diameter can extend along a majority of the working length of the catheter advancement element 300, including the proximal portion 366. This first region of uniform outer diameter can transition to a second region of uniform outer diameter located distal to the first region. This transition can incorporate a smooth taper or step change in outer diameter between the two regions. A second region of uniform outer diameter having a larger size and located distal to the first region can help fill the lumen of a larger diameter catheter without the entire working length of the elongate body having to be this larger size. In this embodiment, the elongate body 360 can have a distal taper that transitions from the second uniform diameter region toward the distal opening and a proximal taper that transitions from the second uniform diameter region toward the first region of uniform outer diameter.

[0117] Depending on the inner diameter of the catheter 200, the difference between the inner diameter of the catheter 200 and the elongate body 360 may be less than about 0.015 inches (0.381 mm), such as in the range of about 0.003 inches to 0.015 inches (0.0762 mm to 0.381 mm), or between 0.006 inches to 0.010 inches (0.1524 mm to 0.254 mm), along at least a portion of the length of the catheter, e.g., at least 10 cm of its length, and preferably at least 15 cm of its length. In this manner, the clearance between the catheter 200 and the elongated body 360 can provide a space of not more than 0.008 inches (0.2032 mm) on either side, or can be about 0.005 inches (0.127 mm) or less, for example, about 0.001 inches to about 0.006 inches (0.0254 mm to 0.1524 mm), preferably about 0.002 inches to about 0.005 inches (0.0508 mm to 0.127 mm), and more preferably about 0.003 inches to about 0.005 inches (0.0762 mm to 0.0508 mm).

[0118] The catheter advancement element 300 has a larger outer diameter and a relatively small inner diameter, especially when a guidewire extends through or into the lumen of the catheter advancement element 300. The elongate body 360 can have an overall geometric profile from the proximal end to the distal end that transitions from a first outer diameter having a first length to a tapered outer diameter having a second length. The first length of this first outer diameter region (i.e., the snug fit region between the distal lumen portion 222 and the elongate body 360) can be at least about 5 cm or 10 cm to about 50 cm. In other embodiments, the snug fit region can extend from the proximal tab or luer 364 substantially to the tapered distal end region 346, and can be up to about 170 cm, depending on the length of the catheter advancement element 300. The length of the tapered outer diameter of the distal end region 346 can be between about 0.5 cm and about 5 cm, about 1 cm and about 4 cm, about 1.5 cm and about 3 cm, or about 2.0 cm and about 2.5 cm. In some embodiments, the length of the distal end region 346 can vary depending on the inner diameter of the catheter 200 with which the catheter advancement element is to be used. For example, the length of the distal end region 346 can be shorter (e.g., 1.2 cm) for a catheter advancement element 300 sized for use with a catheter 200 having an inner diameter of about 0.054 inches (1.372 mm) or longer (e.g., 2.5 cm) for a catheter advancement element 300 sized for use with a catheter 200 having an inner diameter of about 0.088 inches (2.235 mm). 10A, the distal end region 346 can have a constant taper over a length of about 1 cm from a larger outer diameter (e.g., at the distal end of marker 344b) to a second, smaller outer diameter at the most distal end (e.g., at the proximal end of marker 344a). In some embodiments, the constant taper of the distal end region 346 can be from an outer diameter of 0.062 inches (1.575 mm) to an outer diameter of 0.031 inches (0.0787 mm).In further embodiments, the constant taper of the distal end region 346 can be from an outer diameter of 0.080 inches (2.032 mm) to an outer diameter of 0.031 inches (0.0787 mm) over a length of about 2.5 cm. The constant taper length of the distal end region 346 can vary, for example, between 0.8 and about 2.5 cm, between 1 cm and 3 cm, or between 2.0 cm and 2.5 cm. The angle of the taper can vary depending on the outer diameter of the elongate body. For example, the angle of the taper can be between 0.9 and 1.6 degrees relative to the horizontal. The angle of the taper can be between 2 and 3 degrees from the centerline of the elongate body 360. The length of the taper of the distal end region 346 can be between about 5 mm and 20 mm, or between about 20 mm and about 50 mm.

[0119] Additionally, the distal end region 346 of the elongate body 360 may be tapered or non-tapered and is configured to extend beyond and protrude from the distal-most end 215 of the lumen portion 222 when the catheter advancement element 300 is inserted into the catheter 200, while the more proximal region of the body 360 (i.e., the first length described above) remains within the lumen portion 222.

[0120] As mentioned, the most distal end 215 of the lumen portion 222 is blunt and has no change in outer diameter dimension, but the distal end region 346 can be tapered, providing an elongated tapered shape for the overall catheter system. Also, the outer diameter of the elongated body 360 approaches the inner diameter of the lumen portion 222, minimizing the step from the elongated body 360 to the outer diameter of the lumen portion 222. Minimizing this step prevents issues with the edge formed by the distal end of the lumen portion 222 catching on tortuous intracerebral vessels, such as the carotid siphon near the ophthalmic artery bifurcation, when the distal end region 346 in combination with the distal end region of the catheter 200 bends and curves within the vascular anatomy. In some embodiments, the inner diameter of lumen portion 222 can be at least about 0.052 inches (1.321 mm), about 0.054 inches (1.372 mm), and the maximum outer diameter of elongated body 360 can be about 0.048 inches (1.219 mm), such that the difference between them is about 0.008 inches (0.2032 mm). In some embodiments, the inner diameter of lumen portion 222 can be at least about 0.088 inches (2.235 mm), and the maximum outer diameter of elongated body can be about 0.080 inches (2.032 mm), such that the difference between them is about 0.080 inches (2.032 mm). In some embodiments, the inner diameter of the lumen portion 222 may be about 0.072 inches (1.829 mm) and the maximum outer diameter of the elongated body 360 is about 0.070 inches such that the difference between them is only 2 / 1000 inches (0.002 inches / 0.0508 mm). In other embodiments, the maximum outer diameter of the elongated body 360 is about 0.062 inches (1.575 mm) such that the difference between them is about 0.010 inches (0.254 mm). Even though the outer diameter of the elongated body 360 extends through the lumen of the lumen portion 222, the lumen portion 222 and the elongated body 360 extending coaxially therethrough are flexible enough to navigate tortuous anatomical structures up to the level of the M1 or M2 arteries without kinking and traumatizing the vessel. Delivery of a catheter with a larger inner diameter for passage through a larger size flow diverter delivery system is preferred.

[0121] The dimensions provided herein are approximate, and each dimension may have an engineering tolerance or allowable variation limit. Use of the terms "about," "approximately," or "substantially" is intended to provide such allowable tolerance for the dimension being referenced. When "about," "approximately," or "substantially" is not used herein with respect to a particular dimension, the dimension need not be exact.

[0122] The elongate body 360 of the catheter advancement element can have a lumen 368 with an inner diameter that does not change over the length of the elongate body, even when there is a taper in the distal end region 346. Thus, the inner diameter of the lumen 368 extending through the tubular portion of the catheter advancement element 300 can remain uniform, and the wall thickness of the distal end region 346 can be reduced to form a taper. The wall thickness can be thinner distally along the length of the taper. In this manner, the material properties in combination with the wall thickness, angle, and length of the taper can all contribute to the overall maximum flexibility of the most distal end of the distal end region 346. From the most distal end, the catheter advancement element 300 transitions in flexibility toward the snug point where it achieves an outer diameter that is about 0.010 inches (0.254 mm) or less different from the inner diameter of the catheter 200.

[0123] The inner diameter of the elongate body 360 may be constant along its length, even where the single lumen passes through the tapered distal end region 346. In another embodiment, the inner diameter of the elongate body 360 may have a first size through the tapered distal end region 346 and a second, larger size through the cylindrical section of the elongate body 360. The cylindrical section of the elongate body 360 may have a wall thickness that varies as the inner diameter of the cylindrical section changes, or a constant wall thickness. As an example, the outer diameter of the cylindrical section of the elongate body 360 may be approximately 0.080 inches. The inner diameter of the elongate body 360 within the cylindrical section may be uniform along the length of the cylindrical portion and may be approximately 0.019 inches. The wall thickness in this section may be approximately 0.061 inches. As another example, the outer diameter of the cylindrical section of the elongate body 360 may again be approximately 0.080 inches. The inner diameter of the elongate body 360 within the cylindrical section may not be uniform along the length of the cylindrical section, but may increase (or increase in steps) from a first inner diameter of about 0.019 inches to a larger second inner diameter of about 0.021 inches. The wall thickness may be about 0.061 inches in the first inner diameter region and about 0.059 inches in the second inner diameter region. The wall thickness of the cylindrical portion of the elongate body 360 may be about 0.050 inches to about 0.065 inches. The wall thickness of the tapered distal end region 346 near the location of the proximal marker band may be the same as the cylindrical portion (about 0.050 inches to about 0.065 inches) and becomes thinner toward the location of the distal marker band. By way of example, the inner diameter at the distal opening from the single lumen may be about 0.020 inches and the outer diameter at the distal opening (i.e., the outer diameter of the distal marker band) may be about 0.030 inches, resulting in a wall thickness of about 0.010 inches compared to the wall thickness of the cylindrical portion which may be up to about 0.065 inches, thus the outer diameter of the distal end 346 may be tapered, as may the wall thickness. The wall thickness of the medium density portion and the non-tapered portion of the tip portion may be about 0.050 inches to about 0.065 inches.The wall thickness of the medium density section and the non-tapered section may be constant. The inside diameter of the medium density section and the tapered end region may be constant.

[0124] The distal portion of the flexible elongate body can have a tapered portion that tapers distally from a first outer diameter to a second outer diameter. The second outer diameter can be about 1 / 2 the first outer diameter. The second outer diameter can be 40% of the first outer diameter. The second outer diameter can be about 65% of the first outer diameter. The first outer diameter can be about 0.062 inches to about 0.080 inches. The second outer diameter can be about 0.031 inches. The second outer diameter can be about 50% of the first outer diameter, about 40% of the first outer diameter, or about 65% of the first outer diameter.

[0125] The length of the taper can also vary depending on the anatomy of the region of interest. The distal end region 346 can be provided with its soft, atraumatic, flexible characteristics by material properties other than external dimensional changes to facilitate endovascular navigation to occlusions in tortuous anatomy. Additionally or alternatively, the distal region 346 of the elongate body 360 can vary in flexibility along its length. The most flexible region of the distal end region 346 can be its distal terminus. Moving along the length of the distal end region 346 from the distal terminus toward the region proximal to the distal terminus. For example, the distal end region 346 can be formed from a material having a Shore material hardness of 35D or less, or about 62A, transitioning to less flexibility proximally near the proximal portion 366 formed from a material having a material hardness of 55D or less, up to 72D, the proximal portion can be a stainless steel hypotube, or a combination of material properties and taper shapes. Materials used to form the elongated body 360 region include PEBAX (PEBAX 25D, 35D, 55D, 69D, 72D, etc.) or blends of PEBAX with lubricant additive compounds such as Mobilize (Compounding Solutions, Lewiston, Maine) (mixes of 25D and 35D, 25D and 55D, 25D and 72D, 35D and 55D, 35D and 72D, 55D and 72D, etc., where the mix ratios may range from 0.1% to 50% of each PEBAX durometer). In some embodiments, the material used to form the elongated body 360 region may be Tecothane 62A. Incorporating a lubricant additive directly into the polymeric elongated body means that the incorporation of a separate lubricant liner, such as a Teflon liner, is not necessary. This allows for a more flexible element that can navigate distal intracranial anatomy and is less likely to kink. Similar materials, with similar advantages, may be used to form the distal lumen portion 222 of the catheter 200. Flexibility in the distal end region 346 may be achieved by combining a soft, lubricious material with a tapered shape.For example, the length of the distal region 346 can be kept shorter than 2-3 cm, while still maintaining optimal deliverability due to the transition in softness of the material from the most distal end 325 to the more proximal regions spaced from the most distal end 325. In one embodiment, the elongate body 360 is formed of PEBAX (polymer block amide) embedded silicone designed to maintain maximum softness. The wall thickness at the distal end of the luminal portion 222 can also be thin enough that the edge (or lip) formed by the distal end of the luminal portion 222 relative to the elongate body 360 is minimized.

[0126] The elongated body 360 has an advantage over a microcatheter in that it can have a relatively large outer diameter, between 0.003 inches and 0.010 inches (0.0762 mm and 0.254 mm) smaller than the inner diameter of the distal lumen portion 222 of the catheter 200, and still retain a high degree of flexibility for navigating tortuous anatomy. If the gap between the two components is too narrow (e.g., less than about 0.003 inches (0.0762 mm)), the force required to slide the catheter advancement element 300 relative to the catheter 200 may result in damage to one or both of the components, increasing the risk to the patient during the procedure. Such a gap results in a fit that is too snug and does not provide optimal relative sliding. If the gap between the two components is too loose (e.g., greater than about 0.010 inches / 0.254 mm), the distal end of the catheter 200 may form edges that are prone to catching on carotid artery dissections or branch vessels while navigating through tortuous cerebral vasculature, such as near the carotid siphon where the ophthalmic artery branches, and the piston effect when retracting the elongated body 360 may be reduced or lost.

[0127] The ID / OD clearance (or gap) between the elongate body 360 and the distal lumen portion 222 may be within this size range (e.g., 0.003 inches to 0.015 inches (0.0762 mm to 0.381 mm), or 0.006 inches to 0.010 inches (0.152 mm to 0.254 mm)) along the majority of their lengths. For example, the elongate body 360 may have a relatively uniform outer diameter of between about 0.048 inches (1.219 mm) to about 0.080 inches (2.032 mm) from the proximal end region to the distal end region to the point where the taper of the distal end region 346 begins. Similarly, the distal lumen portion 222 of the catheter 200 may have a relatively uniform inner diameter of between about 0.054 inches (1.372 mm) to about 0.088 inches (2.235 mm) from the proximal end region to the distal end region. As such, the difference between their respective inner and outer diameters along the majority of their lengths can be within a gap size range of 0.003 inches to 0.015 inches (0.0762 mm to 0.381 mm). The tapered distal end region 346 of the elongate body 360 has a larger gap size compared to the inner diameter of the distal lumen portion 222. However, during use, this tapered distal end region is configured to extend distally of the distal end of the catheter 200 such that a region of the elongate body having an outer diameter sized to match the inner diameter of the distal portion 222 is disposed within the lumen of the catheter 200, minimizing edges at the distal end of the catheter 200.

[0128] The elongate body 360 can be formed from a variety of materials that provide suitable flexibility and lubricity. Exemplary materials include high density polyethylene, 77A PEBAX, 33D PEBAX, 42D PEBAX, 46DPEBAX, 54D PEBAX, 69D PEBAX, 72D PEBAX, 90D PEBAX, and mixtures thereof, or materials with comparable stiffness and lubricity. In some embodiments, the elongate body 360 is an unreinforced, non-torqueing catheter with a relatively large outer diameter designed to fill the lumen into which it is inserted and a relatively small inner diameter to minimize clearance at the distal end of the device. In other embodiments, at least a portion of the elongate body 360 may be reinforced (e.g., a braided reinforcement layer) to improve navigation and torquability. The flexibility of the elongate body 360 can be greater toward the distal end region 346 such that the distal region of the elongate body 360 is softer, more flexible, and more easily articulates and bends than the more proximal regions. For example, the more proximal region of the elongate body can have a bending stiffness that is flexible enough to navigate tortuous anatomical structures such as the carotid siphon without kinking. If the elongate body has a braided reinforcement layer along at least a portion of its length, the braided reinforcement layer can terminate spaced apart proximal to the distal end region 346. For example, the distance from the end of the braid to the most distal end 325 can be about 10 cm to 15 cm, or about 4 cm to about 10 cm, or about 4 cm to about 15 cm.

[0129] In some embodiments, the elongate body 360 may be generally tubular along at least a portion of its length to have a single lumen 368 that extends parallel to the longitudinal axis of the catheter advancement element 300 (see FIGS. 9A-9B, and 10A-10B). In one embodiment, the single lumen 368 of the elongate body 360 is sized to accommodate a guidewire, although the use of the catheter advancement element 300 generally obviates the need for a guidewire lead. Preferably, the assembled system does not include a guidewire or includes a guidewire that is placed inside the lumen 368 recessed away from the distal opening. Guidewires are designed to be very flexible so that they can bend and navigate the severe bends of the anatomy. However, many mainline guidewires are stiff along their longitudinal axis and / or have an outer diameter small enough to find their way through the occlusion rather than slipping around it or catching on the vessel wall and increasing the risk of perforation. In some cases, these guidewires can cause vessel perforation and / or dissection. Guidewires tend to redirect into branches rather than remaining in the larger vessel. This helps select branches, but can be difficult to navigate in tortuous anatomy. It is problematic to navigate and follow the main blood flow through the occlusion. Thus, even though a guidewire may have a small outer diameter at its distal tip and is very flexible at the distal tip, the guidewire typically cannot atraumatically explore an occlusion or other structure, and repeated advances pose the risk of perforation. The guidewire does not deflect when it encounters a relatively tight space, such as the proximal surface of an occlusion or dissection flap. Instead, it embeds itself in and penetrates such structures. The catheter advancement element 300 has a softness, taper, and size that finds and / or creates space. For example, when an occlusion, such as an arteriosclerotic lesion or an embolus, is encountered, the catheter advancement element 300 can slide between the occlusion and the vessel wall, rather than penetrating through it as a guidewire would. In the case of a partially occluded vessel, such as a stenosis in the carotid artery flow, the catheter advancement element 300 can find a path through the stenosis intact and safely. Also, the catheter advancing element 300 veers away from the dissection flap so as to remain within the larger lumen. The softness, taper, and size of the catheter advancing element 300 allow it to be repeatedly passed through the carotid artery into the intracerebral aneurysm without penetrating or bypassing these structures. The distal tip region veers past such structures so that the catheter system can be advanced through these structures in a safe manner to the distal occlusion site or nearby probes and wedges.

[0130] The guidewire 500 can extend generally concentrically through a single lumen from a proximal opening of the catheter advancement element 300 to a distal opening 326 at the distal end 325 (see FIG. 10B). In some embodiments, the proximal opening is at the proximal end of the catheter advancement element 300 such that the catheter advancement element 300 is configured for an over-the-wire (OTW) procedure. In other embodiments, the proximal opening is a rapid exchange opening through the wall of the catheter advancement element such that the catheter advancement element 300 is configured for rapid exchange rather than or in addition to OTW. In this embodiment, the proximal opening extends through the sidewall of the elongate body 360 and is located distal to the proximal portion 366, spaced from the proximal tab or luer 364. The proximal opening can be located approximately 10 cm from the distal end region 346 and approximately 20 cm from the distal end region 346. In some embodiments, the proximal opening can be located near the area where the elongate body 360 is joined to the proximal portion 366, for example, just distal to the end of the hypotube. In other embodiments, the proximal opening is located more distally, such as about 10 cm to about 18 cm from the most distal end of the elongate body 360. A proximal opening located closer to the distal end region 346 allows for easier removal of the catheter advancement element 300 from the catheter 200 while leaving the guidewire in place for a "rapid exchange" type procedure. Rapid exchange can be relied upon to have only one person perform the exchange. The catheter advancement element 300 can be easily substituted for another device using the same guidewire that remains in place. The single lumen 368 of the elongate body 360 can be configured to receive a guidewire 500 having a diameter range of 0.014 inches (0.356 mm) to 0.018 inches (0.457 mm), or a diameter range of 0.014 inches to 0.022 inches (0.356 mm to 0.559 mm). In this embodiment, the diameter of the inner lumen of the elongate body 360 can be 0.020 inches to 0.024 inches (0.508 mm to 0.610 mm).The guidewire, catheter advancement element 300, and catheter 200 can all be coaxially assembled for insertion through the working lumen of the guide sheath. The inner diameter of the lumen 368 of the elongate body 360 can be 0.019 inches to about 0.021 inches (0.483 mm to 0.533 mm). The opening 326 distal to the lumen 368 can have an inner diameter of about 0.018 inches to about 0.024 inches (0.457 mm to 0.610 mm). The opening 326 distal to the lumen 368 can have an inner diameter of about 0.016 inches to about 0.028 inches. The distal opening 326 is sized to receive a guidewire, which can be a 0.014 inch to 0.024 inch guidewire.

[0131] The region proximal to the distal end region 346 may be tapered such that the outer diameter tapers over a length of about 0.5 cm to about 5 cm, 1 cm to 4 cm, or other length as described elsewhere herein. The larger outer diameter can be at least about 1.5 times, about 2 times, about 2.5 times, about 3 times, or more than the smaller outer diameter. The distal end region 346 can be tapered along a distance from a first outer diameter to a second outer diameter, the first outer diameter being at least 1.5 times the second outer diameter. In some embodiments, the distal end 346 tapers from about 0.080 inches (2.032 mm) to about 0.031 inches (0.787 mm). In some embodiments, the smaller outer diameter at the distal end of the taper can be between about 0.026 inches (0.66 mm) and 0.040 inches (1.016 mm), and the larger outer diameter at the proximal side of the taper can be between about 0.062 inches (1.575 mm) and about 0.080 inches (2.032 mm). Additionally, the distal end region 346 can be formed from a material having a material hardness (e.g., 62A and 35D) that transitions proximally to an increasingly harder material (e.g., 55D and 72D) until the proximal portion 366. The first portion of the elongated body 360, including the distal end region, can be formed from a material having a material hardness of 35D and a length of about 10 cm to about 12.5 cm. The first portion of the elongated body 360, including the distal end region 346, can be formed from a material having a material hardness of 62A and a length of about 10 cm to about 12.5 cm. The second portion of the elongated body 360 can be formed from a material having a material hardness of 55D and can be about 5 cm to about 8 cm in length. The third portion of the elongated body 360 can be formed from a material having a material hardness of 72D and can be about 25 cm to about 35 cm in length. The three portions combined can form an insertion length of the elongated body 360 from where the proximal portion 366 joins the elongated body 360 to the end of the distal end region 346 which can be about 49 cm in length.

[0132] The catheter advancement element 300 can incorporate a reinforcing layer. The reinforcing layer can be a braid or other type of reinforcement and is useful for improving the torqueability of the catheter advancement element 300 and for bridging components of the catheter advancement element that have different flexibility. The reinforcing layer can bridge the transition from the stiff proximal portion 366 to the flexible elongate body 360. In some embodiments, the reinforcing layer can be a braid disposed between the inner and outer layers of PEBAX. The reinforcing layer can terminate at a proximal distance to the distal end region 346. The distal end 346 can be formed from a material having a material strength of up to about 35D. The first portion can be an unreinforced polymer with a length of about 4 cm to about 12.5 cm without metal reinforcement. A third portion of the elongate body 360, located proximal to the first portion, can include a reinforcing layer and can extend a total of about 37 cm to the unreinforced distal portion. The proximal end region of the reinforcement layer may overlap with the distal end region of the proximal portion 366 such that a small overlap of the hypotube and reinforcement material exists near the transition between the proximal portion 366 and the elongated body 360.

[0133] The tubular portion of the catheter advancement element 300 can have an outer diameter with at least one snug point. The difference between the outer diameter at the snug point and the inner diameter of the lumen at the distal end of the distal catheter portion can be about 0.015 inches (0.381 mm) or less, or can be about 0.010 inches (0.254 mm) or less. The at least one snug point of the tubular portion can be a point along the length of the tubular portion. The at least one snug point of the tubular portion can have a length of at least about 5 cm to about 50 cm, including, for example, at least about 6 cm, at least about 7 cm, at least about 8 cm, at least about 9 cm, at least about 10 cm, at least about 11 cm, or at least about 12 cm up to about 50 cm. The length need not be uniform, and the length need not be snug along its entire length. For example, the area of ​​the snug point can include a ridge, groove, slit, or other surface feature.

[0134] In other embodiments, the entire catheter advancement element 300 can be a tubular element configured to receive the guidewire 500 through both the elongate body 360 and the proximal portion 366. For example, the proximal portion 366 can be a tubular element having a lumen communicating with the lumen 368 extending through the elongate body 360. In some embodiments, the proximal portion 366 can be a PTFE-coated stainless steel skived hypotube having an outer diameter of 0.026 inches (0.660 mm). In other embodiments, the outer diameter can be 0.024 inches (0.610 mm) to 0.030 inches (0.762 mm). In some embodiments, such as over-the-wire embodiments, the proximal portion 366 can be a skived hypotube that connects with a proximal hub or luer 364. The proximal portion 366 can extend eccentrically or concentrically with respect to the distal lumen portion 222. The proximal portion 366 can be a stainless steel hypotube. The proximal portion 366 can be a solid metal wire with a circular or elliptical cross-sectional shape. The proximal portion 366 can be a flattened ribbon of wire with a rectangular cross-sectional shape. The ribbon of wire can be bent into a circular, elliptical, C-shaped, or quarter-circular, or other cross-sectional shape along an arc. The proximal portion 366 can have any of a variety of cross-sectional shapes, including circular, elliptical, C-shaped, D-shaped, or other shapes, whether or not a lumen extends therethrough. In some embodiments, the proximal portion 366 is a hypotube having a D-shape, such that the inner-facing side is flat and the outer-facing side is rounded. The rounded side of the proximal portion 366 can be shaped to engage a corresponding rounded inner surface of the sheath 400. The hypotube can have a lubricious coating, such as PTFE or other lubricious polymer, covering the hypotube. The hypotube can have an inner diameter of about 0.021 inches (0.533 mm), an outer diameter of about 0.0275 inches (0.699 mm), and an overall length of about 94 cm, providing a working length of the catheter advancement element 300 that is about 143 cm.Including the proximal luer 364, the catheter advancement element 300 can have an overall length of about 149 cm. In some embodiments, the hypotube can be a tapered section with a length of about 100 mm, beginning proximally with a thickness of 0.3 mm and ending with a thickness of 0.10 mm to 0.15 mm. In further embodiments, the elongate body 360 can be a solid element connected with a proximal section 366 that does not have a guidewire lumen.

[0135] 9A as having a smaller outer diameter compared to the outer diameter of elongate body 360. Proximal portion 366 need not have a smaller outer diameter and can have the same outer diameter as the outer diameter of elongate body 360. Proximal portion 366 can incorporate a hypotube or other rigid element that is coated with one or more layers of polymer, resulting in proximal portion 366 having substantially the same outer diameter as elongate body 360.

[0136] At least a portion of the solid elongate body 360, such as the elongate distal end region 346, can be formed of, embedded in, or attached to a malleable material that is trimmed to a smaller dimension at the distal end. The distal end region 346 can be angled or shaped as desired, similar to a guidewire. The malleable length of the elongate body 360 can be at least about 1 cm, 3 cm, 5 cm, and can be up to about 10 cm, 15 cm, or longer. In some embodiments, the malleable length can be about 1%, 2%, 5%, 10%, 20%, 25%, 50% or more of the total length of the elongate body 360. In some embodiments, the catheter advancement element 300 can have a working length of about 140 cm to about 143 cm, and the elongate body 360 can have an insertion length of about 49 cm. The insertion length can be about 49.5 cm of the PEBAX portion of the elongated body 360. Thus, the flexible length of the elongated body 360 can be along about 0.5 cm to about 25 cm or longer, and the shape change can be the action of the user manually shaping the malleable length prior to insertion, or the distal end region 346 can be preformed at the time of manufacture to a particular angle or curve. In another embodiment, the shape change can be a reversible and actuatable shape change such that the distal end region 346 forms a shape upon actuation by the user, or the distal end region 346 can be used in a straight format until a shape change is desired by the user. The catheter advancement element 300 can also include a forming mandrel extending through the lumen of the elongated body 360 so that the physician can shape the distal end region 346 to a desired shape during use. In this manner, a shapeable distal end region 346 can be incorporated into the elongated body 360 having a guidewire lumen.

[0137] The elongate body 360 can extend along the entire length of the catheter 200, including the distal lumen portion 222 and the proximal extension 230, or the elongate body 360 can incorporate a proximal portion 366 that is generally aligned alongside the proximal extension 230 of the catheter 200. The proximal portion 366 of the elongate body 360 can be disposed coaxially or eccentrically relative to the elongate body 360. The proximal portion 366 of the elongate body 360 can have a lumen extending therethrough. Alternatively, the portion 366 can be a solid rod or ribbon without a lumen.

[0138] 9A-9B and 10A-10B, like the distal lumen portion 222 of the catheter 200, the elongate body 360 can have one or more radiopaque markers along its length. The one or more markers can vary in size, shape, and location. One or more markers 344 can be incorporated along one or more parts of the catheter advancement element 300, such as a tip-to-tip marker, a tip-to-taper marker, a RHV proximal marker, a fluoroscopy marker, or other markers, to provide various information regarding the relative positions of the catheter advancement element 300 and its components. At least one radiopaque marker can identify a tapered end region of the elongate body 360. 10A-10B, the distal end region can have a first radiopaque marker 344a and a second radiopaque marker can be positioned to indicate the boundary between a more proximal region of elongate body 360 having a uniform or maximum outer diameter and the tapered portion of distal region 346. This provides the user with information regarding the optimal extension of distal end region 346 relative to the distal end of luminal portion 222 to minimize an edge (or lip) at the distal end of luminal portion 222 for navigation through tortuous anatomy. In other embodiments, for example, where distal end region 346 is not necessarily tapered but instead has a varying overall flexibility along its length, the second radiopaque marker can be positioned to indicate a region where the relative flexibility of elongate body 360 (or distal end region 346 of elongate body 360) and the distal end of luminal portion 222 are substantially the same. The marker material may be a platinum / iridium band, tungsten, platinum or tantalum impregnated polymer, metal coil or braid, or other radiopaque marker. The radiopaque marker preferably does not affect the flexibility of the distal end region 346 and the elongated body 360. In some embodiments, the radiopaque marker is extruded PEBAX (filled with radiopaque tungsten).In some embodiments, the proximal marker band can be about 2.0 mm wide and the distal marker band can be about 2.5 mm wide to provide discernible information about the distal end region 346. In other embodiments, the proximal marker is of a different structure and / or material than the proximal marker. In addition, the radiopaque marker bands 344a, 344b can be visible to the user without fluoroscopy, for example, prior to inserting the catheter system into the patient. The marker bands 344a, 344b can form a contrasting color visible to the user compared to the color of the polymer of the flexible elongate body, such as a black band relative to the white color of the polymer. The marker bands 344a, 344b can help achieve a particular relative extension of the catheter advancement element 300 relative to the catheter 200 prior to inserting the device into the RHV.

[0139] The catheter 200 and catheter advancement element 300 (with or without a guidewire) can be advanced as a single unit through both bends of the carotid siphon. Both bends can be traversed in one smooth pass or throw to a target in the intracerebral vasculature without incremental adjustment of their relative extension and without resorting to conventional incremental advancement techniques with conventional microcatheters. The catheter 200 with the catheter advancement element 300 extending through it allows them to be advanced in unison, in the same relative position, from the first bend of the siphon through the second bend, across the distal cavernous carotid artery, and into the ACA and MCA. Importantly, the two component advancement elements 300 can be advanced in one smooth motion through both bends without changing hand position.

[0140] The catheter advancement element 300 can be juxtaposed to the catheter to provide an optimal relative extension between the two components for a single smooth advancement. The catheter advancement element 300 can be positioned through the lumen of the catheter such that its distal end region 346 extends just beyond the distal-most end 215 of the catheter 200. The distal end region 346 of the catheter advancement element 300 can eliminate a gradual transition between the inner member and the outer catheter 200 so that the catheter 200 can easily traverse the multiple angled bends of the carotid siphon, thereby avoiding issues with snagging on branch vessels in that region of the vasculature. For example, the optimal relative extension can be the distal end region 346 of the elongate body 360 extending just distal to the distal-most end 215 of the catheter 200. The length of the distal end region 346 extending distal to the distal-most end 215 of the catheter 200 during advancement can be between 0.5 cm and about 4 cm. This apposition may be a locked engagement by a mechanical element, or may simply be by a user holding the two components together. The mechanical fastening element may be a fixed or removable mechanical element configured to connect to one or more of the catheter 200, the catheter advancement element 300, and the guidewire 500. The mechanical fastening element may be slidable along at least the length of the system components when connected, thereby allowing adjustment of the mechanical attachment. The mechanical fastening element 605 may have a disposable feature, or may be reusable to connect to at least a portion of the shaft, or to a more proximal portion of the component, such as a luer or hub at the proximal end of the component. In some embodiments, the mechanical fastening element 605 may be attached to the catheter 200, the catheter advancement element 300 in a desired relative position such that the catheter 200 and the catheter advancement element may be advanced together without inadvertently changing their relative state. While the mechanical fastening element 605 is attached to the catheter 200 and the catheter advancement element 300, their relative positions can be changed, if desired.A mechanical fastening element 605 can additionally be attached to a region of the guidewire 500 that extends through the catheter advancement element 300, thereby maintaining the relative positions of all three components during advancement until relative sliding movement is desired. In further embodiments, depending on which step of the method is being performed, the location of attachment of the mechanical fastening element 605 can be changed from engaging a first combination of components (e.g., catheter, catheter advancement element, and guidewire) to engaging a different combination of components (e.g., catheter advancement element and guidewire). In further embodiments, the guidewire 500 is attached and maintained to the catheter advancement element 300 via a rotating hemostatic valve that interfaces with the proximal hub 434, and the catheter advancement element 300 is attached and maintained to the catheter 200 by another mechanical fastening element 605. Regardless of whether the relative positions of the components are fixed by a mechanical element, a combination of mechanical elements, or by the user, the proximal portion 264 of each of the catheter 200 and the catheter advancement element 300 (and guidewire 500, if present) is configured to be held at one point by the user. For example, when the catheter and catheter advancement element are manually advanced and / or retracted, the one point may be just between the user's index finger and thumb.

[0141] The components can be advanced with a guidewire, with a pre-placed guidewire, or without a guidewire. In some embodiments, the guidewire can be pre-assembled with the catheter 200 and the catheter advancing element, which is loaded through the lumen of the catheter 200, with the guidewire extending through the lumen of the catheter advancing element, all prior to insertion into the patient. The pre-assembled components can be inserted into the sheath 400 at the same time and advanced together to pass the bend in the carotid siphon. A guidewire can be placed within the lumen 368 of the catheter advancing element 300 proximal to the tapered distal end region 346, or proximal to the distal tip, for use when the catheter advancing element without the guidewire does not reach the desired location. For example, the distal end of the guidewire can be positioned about 5 cm to about 40 cm, or about 20 cm to about 30 cm proximal to the distal end region 346 of the catheter advancing element 300. In this position, the guidewire does not interfere with the performance or function of the catheter advancing element. A guidewire can be positioned within the lumen of the catheter advancement element such that its distal end is within the catheter advancement element during the process of advancing the assembled system of devices, and can be extended out of the distal opening 326 from the catheter advancement element if necessary for navigation. In one example, a rescue guidewire is placed within the lumen of the catheter advancement element, with the distal end of the guidewire located about 0 cm to about 40 cm proximal, about 5 cm to about 35 cm proximal, about 7 cm to about 30 cm proximal, and preferably about 10 cm proximal to the distal end of the catheter advancement element. The guidewire in this placement position can provide additional support to the proximal portion of the system without affecting the flexibility and handling of the distal portion of the system.

[0142] Standard cerebrovascular interventions, and almost all vascular interventions, are based on the concept of a guidewire leading a catheter to the desired location. Guidewires are typically preformed and often find side branches in misplaced locations where the guidewire bunches up or slips out, creating a time-consuming and cumbersome problem to resolve during the intervention that requires the operator to redirect the guidewire. Furthermore, the tendency of guidewires to enter side branches can be dangerous. Guidewires are typically 0.014"-0.018" (0.356mm-0.457mm) in the anatomy and often find and damage dissection flaps or small branches that accommodate this size, which can result in minor bleeding or dissection and further blockage. In a delicate area such as the brain, these events can be catastrophic. The tendency of guidewires to bunch and slip out can also create a dissection surface where the leading end of the guidewire, which can be advanced alone or as part of a triaxial system, can also injure small vessels.

[0143] In contrast, the catheter advancement element 300 described herein preferentially remains within the larger lumen of the conduit vessel. The catheter advancement element 300 delivers to the largest lumen within the anatomy, even considering the highly tortuous anatomy and the bends to navigate. The catheter advancement element 300 also preferentially follows the larger lumen at the bifurcation or incision flap while following the maximum blood flow, thereby preserving the general direction and angulation of the previous vessel. When looking at the standard anatomy found in the brain vasculature, the Circle of Willis is served by two vertebral arteries and two carotid arteries. These four arteries are the access points to the brain anatomy, and the path of the catheter advancement element 300 can be identified and confirmed in the standard brain anatomy model.

[0144] In the anterior circulation, when the conduit arterial point of entry for intracerebral vasculature processing is the internal carotid artery (ICA), the catheter advancement element can guide a large diameter catheter to the M1 segment of the middle cerebral artery (MCA), bypassing the anterior communicating artery (ACA) and the frontotemporal branch (ATB). The highly flexible nature of the catheter advancement element 300 combined with the flexible nature of the distal portion of most intracerebral catheters allows delivery through severe tortuous sections. Regardless of the tortuous nature of the arterial course, the catheter advancement element 300 tends to guide the bends and deliver from the parent artery to the largest child artery, e.g., from the ICA to the M1 segment of the MCA. The M2 level branching (or bifurcation) of the M1 can vary, but is often shown to have two major M2 branches (superior and inferior), which can branch "evenly" or "unevenly" depending on the anatomy, which can vary significantly between patients. If the branching MS2 calibers are of similar size and angle, the catheter advancement element 300 may take one of the two branches. If the goal of catheter placement is not the preferred angle of the artery or the size of the artery, the catheter advancement element 300 may be bent and oriented (e.g., by shaping a malleable distal tip) or a guidewire may be used.

[0145] In some anatomies where the M2 branches are "evenly" sized, a back and forth motion can aid in selecting one branch and then the other while avoiding the need or use of a curved distal tip of the guidewire or catheter advancing element. The back and forth motion allows the catheter advancing element to be aimed at either branch of the M2. The catheter advancing element achieves some curvature that helps to orient it into the branch vessel even if it is initially straight. Thus, if the operator encounters an M2 branch and wishes to cannulate either branch of the equally divided branches, selection of either branch allows the use of a catheter advancing element without a guidewire.

[0146] Thus, major pathways such as the ICA, the middle intracerebral artery, and its tributaries in the anterior circulation naturally become the preferred pathways for the described catheter advancement elements and subsequent large diameter catheter delivery (via access from the ICA). A similar event may occur in the posterior circulation accessed via the vertebral arteries arising from the right and left subclavian arteries. The catheter advancement elements follow the major pathway in this circulation by passing from the vertebral artery to the basilar artery and then from the major branches of the basilar artery: the posterior intracerebral artery and the superior cerebellar artery in the posterior circulation.

[0147] Navigation (or guiding) with a catheter advancement element can provide maximum deliverability with minimal vessel trauma. The blunt end of a larger diameter catheter, when pushed by the operator, can tend to take on a larger curvature as it bends the vessel, causing a "razoring" effect in curved vessels. This blunt end can carve or "shave" the larger curvature with a sharp edge, increasing the risk of dissection along anatomical planes in multi-layered medium or large sized arteries or veins (Catheter Cardiovasc. Interv. 2014 Feb; 83(2):211-20 shows an example). The catheter advancement element can act to minimize these catheter edges. Positioning the catheter advancement element within the lumen of a larger diameter catheter so that the taper marker of the catheter advancement element is optimally aligned with the distal end marker of the catheter minimizes the blades, thereby eliminating "shaving" as the large diameter catheter is advanced through vessel bends. This is particularly useful for the anatomical structure of the brain. Access to the distal carotid siphon, particularly the distal ophthalmic artery, which branches off from the more severely tortuous curvature of the final bend of the carotid siphon, the "S-curve," typically the "knee" of the carotid siphon, seen as a portion of the terminal internal carotid artery (ICA), can be improved using the access system described herein. Proper alignment of the catheter advancement element within the large diameter catheter (the "tip-to-taper" position indicated by the distal tip marker) relative to the taper marker of the catheter advancement element maximizes the chances of avoiding shaving and snagging in the ophthalmic artery during manual advancement of the catheter system. Placing the taper marker of the catheter advancement element at or beyond the bifurcation of the ophthalmic artery minimizes these deleterious effects, allowing the large diameter catheter to pass through the ophthalmic artery without issue. In the relatively straight section common after passing through the siphon, the large diameter catheter can be advanced over the catheter advancement element, which acts as a guide element to the destination.The transition between the catheter advancement element and the distal edge of the larger diameter catheter is not critical, especially compared to the gradual change with a typical microcatheter or guidewire that does not prevent snagging in a branch, such as the ophthalmic artery. The catheter advancement element allows for manipulation of the larger diameter catheter to a distal site without the use of a microcatheter or guidewire.

[0148] The systems described herein can incorporate a guidewire, but it is not necessary. And, when a guidewire is used, it does not need to be advanced independently (i.e., without a sheath) to the desired treatment site. The systems described herein can incorporate a relatively large diameter catheter that is delivered over a guidewire without disturbing the anatomy, reducing the risk of stroke and downstream of fragmentation of the occlusion, and has improved efficiency. In addition, the systems described herein are single-operator systems that allow the operator to work with one RHV, and in the case of spinned components, the "knob" of one hand can operate all the elements used to navigate the anatomy. This can be referred to as "monopoint."

[0149] Any of the flow diverters described herein can be used with any device delivery system, including but not limited to the devices described herein, and the flow diverter can be delivered via an access catheter, including but not limited to the catheters described herein, and other catheters.

[0150] How to use The access catheter system, flow diverter, and delivery system described herein can be used to access and treat intracranial and cerebral aneurysms. The access catheter system provides mono-point manipulation at the base sheath for various tools to be used in a manner that provides improved safety, ease of use, and single operator manipulation compared to conventional systems. These catheter advancement elements provide easy and rapid access to the target site, even through tortuous anatomical structures to reach the target lesion. The flow diverter and delivery system described herein provide improved, more precise, and safer aneurysm treatment. In addition, the flow diverter described herein potentially reduces complication rates due to the shape (or configuration) of the device placement against the wall.

[0151] A method for treating a cerebral or intracranial aneurysm will now be described. The method may include a flow diverter and a flow diverter delivery system advanced over a guidewire through (or not through) an outer catheter extending through a base sheath. The catheter may be a conventional full-length catheter, but is preferably a catheter having a larger diameter lumen portion 222 mated with a smaller diameter proximal control element 230, as shown in Figures 9A-9B, to allow monopoint manipulation at the base sheath hub. The base sheath 400 can be inserted into a vessel (e.g., femoral artery) and advanced toward a cerebral or intracranial vessel having an aneurysmal portion, at least to the level of the common carotid artery. The outer catheter 200 is advanced through the hub (e.g., RHV 434) of the base sheath 400 until the distal end of the catheter 200 exits the distal opening 408 of the base sheath 400 (see Figure 11A). The catheter 200 can be advanced into the high ICA. The outer catheter 200 may be part of a catheter system that includes an inner catheter 300 having a tapered end region 346 extending distally of the distal end of the outer catheter 200. The outer catheter may be led through the carotid siphon CS toward the aneurysm A targeted by the inner catheter 300. As shown in FIG. 11A, the outer catheter 200 and the inner catheter 300 may be advanced until at least a portion of the tapered end region of the inner catheter 300 is positioned across the aneurysm of interest. Alternatively, the outer catheter 200 may be held in place at a position between the distal end of the base sheath 400 and the aneurysm A (e.g., near or at the carotid siphon CS) while the guidewire 500 is advanced through the hub of the base sheath 400 until the guidewire is positioned across the aneurysm A.

[0152] The distal end region of the outer catheter 200 can be advanced over the inner catheter 300 to position it across the aneurysm A. The inner catheter 300 is withdrawn from the outer catheter 200, and the outer catheter 200 is held in position across the aneurysm (see FIG. 11B). The outer catheter 200 can have an ID of 2.0 mm to 3.0 mm configured to receive a flow diverter 700 mounted within a flow diverter delivery system 800. The flow diverter delivery system 800 and flow diverter 700 can be advanced to the distal end region of the outer catheter (e.g., through the hub of the outer catheter, or through the hub of the base sheath 400, and into the distal tubular portion of the catheter 200 if the catheter 200 is a partial length catheter). While the flow diverter delivery system 800 is held across the aneurysm A, the outer catheter 200 can be withdrawn to expose the flow diverter delivery system 800 (see FIG. 11C). The flow diverter 700 of the flow diverter delivery system 800 can then be deployed across the aneurysm A (see FIG. 11D).

[0153] The flow diverter delivery system 800 may include an inner core member 820 and an outer restraining sleeve 810. The flow diverter 700 may be attached to the inner core member 820 and restrained by the outer restraining sleeve 810 during delivery. The flow diverter 700, restrained by the outer restraining sleeve 810, may be delivered via a delivery catheter having an inner diameter of 2.0 mm to 3.0 mm. Deployment of the flow diverter 700 across the aneurysm A may be accomplished by retracting the outer restraining sleeve 810 of the delivery system 800 to expose the flow diverter, while the inner core member 820 holds it in place distal to the aneurysm A, for example, with reference to FIG. 11D.

[0154] The flow diverter 700 may be any of those described above. For example, the flow diverter may be a laser cut deployable metal tube. The flow diverter may be formed of a first and a second deployable tube, each being a laser cut metal tube. The first deployable tube may be a laser cut metal tube and the second deployable tube may be a braided tube. Alternatively, the first deployable tube may be a laser cut metal tube and the second deployable tube may be a polymer sleeve. The flow diverter may have a composite structure. The composite structure may include two end sections made up of laser cut tubes and a middle section that is a blade.

[0155] material One or more components of the catheters, delivery systems, and flow diverters described herein can comprise or be made from a variety of materials, including metals, metal alloys, polymers, metal polymer composites, ceramics, hydrophilic polymers, polyacrylimides, polyesters, polyamides, polyethylene, polyurethanes, copolymers thereof, polyvinyl chloride (PVC), PEO, PEO impregnated polyurethanes, such as Hydrothane Tecophilic polyurethanes, Tecothane, PEO soft segmented polyurethanes blended with Tecoflex, thermoplastic starch, PVP, and combinations thereof, or other suitable materials.

[0156] Some examples of suitable cut tubes or flat metals include Nitinol, a layered tube having an outer Nitinol and an inner core of a radiopaque material such as tantalum, platinum, iridium, gold, alloys, etc. Additionally, the material can be cobalt, cobalt alloys, or stainless steel.

[0157] Some examples of suitable materials and metal alloys include stainless steels, such as 304V, 306L, and 316LV stainless steel; mild steel; nickel-titanium alloys, such as linear elastic and / or superelastic Nitinol; nickel-chromium-molybdenum alloys, (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; HASTELLOY® C276®; nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.); nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N®, etc.); nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY®, etc.); B2®, UNS:N10665), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten alloys or tungsten alloys, etc., cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®, etc.), platinum strengthened stainless steels, titanium, combinations thereof, etc., or other suitable materials described herein.

[0158] The inner liner materials of the catheters described herein can include low friction polymers such as PTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene) or PTFE with a polyurethane layer (Tecoflex). Reinforcement layer materials of the catheters described herein such as stainless steel, nitinol, nitinol braid, helical ribbon, helical wire, cut stainless steel, etc., or stiff polymers such as PEEK can be incorporated to provide mechanical integrity for torque application and / or to avoid flattening or kinking. Reinforcement fiber materials of the catheters described herein can include various high toughness polymers such as, for example, Kevlar, polyester, metaparamide, PEEK, monofilament, multifilament bundles, high tensile strength polymers, metals, alloys, etc. The outer jacket materials of the catheters described herein provide mechanical integrity and can be constructed from various materials such as polyethylene, polyurethane, PEBAX, nylon, Tecothane, etc. Other coatings for the catheters described herein include Paralene, Teflon, silicone, polyimide-polytetrafluoroethylene, and the like. The inner liner may further include various surface finishes, such as dimples, ridges, elongated ridges, and grooves. The surface finishes may be randomly arranged along the length of the catheter, linearly finished, spirally finished, or arranged in a specific pattern. It is contemplated that the inner liner may include a mixture of different surface finishes, for example, one section having dimples and another section having grooves. Furthermore, the surface finish may be incorporated along the entire length of the catheter or only on a portion of the catheter. It is also contemplated that the inner liner may further include an electrospray layer, whereby a material may be incorporated into the inner liner. Exemplary materials may include the low friction materials discussed above.Alternatively, the electrosprayed or electrospun layer may incorporate a beneficial agent that is released from the coating when exposed to blood or compressed from a thrombus; for example, the beneficial agent may be heparin or tissue plasminogen activator (tPA) encapsulated in alginate.

[0159] The embodiments describe catheters, delivery systems, and methods for delivering catheters to target anatomical structures. However, while some embodiments are described with particular reference to delivering catheters to target vessels in the cerebrovascular anatomical structure, such as intracerebral vessels, the embodiments are not so limited and certain embodiments are applicable to other applications. For example, the catheters can be adapted for delivery to various neurological structures, such as subclavian, vertebral, carotid vessels, as well as coronary or peripheral vascular anatomical structures, to name a few potential applications. It should also be understood that while the systems described herein are described as being useful in treating certain conditions or pathologies, the conditions or pathologies treated may vary and are not intended to be limiting.

[0160] Various embodiments are described with reference to the drawings. However, an embodiment may be implemented without one or more of these specific details or in combination with other known methods and configurations. In this description, numerous specific details, such as specific configurations, dimensions, and processes, are described for a thorough understanding of the embodiments. In other instances, well-known processes and manufacturing techniques have not been described in particular detail so as not to unnecessarily obscure the description. References throughout this specification to "one form," "an embodiment," "one embodiment," "an embodiment," or the like mean that a particular feature, structure, configuration, or characteristic described is included in at least one form or embodiment. Thus, references to "one form," "an embodiment," "one embodiment," "an embodiment," or the like in various places throughout this specification are not necessarily referring to the same form or embodiment. Furthermore, particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments.

[0161] Use of relative terms throughout this specification can refer to relative positions or directions. For example, "distal" can refer to a first direction away from a reference point. Similarly, "proximal" can refer to a position in a second direction opposite to the first direction. The reference point used herein can be the operator, such that the terms "proximal" and "distal" refer to the worker (or operator) using the device. A region of the device closer to the operator can be described herein as "proximal" and a region of the device further away from the operator can be described herein as "distal". Similarly, the terms "proximal" and "distal" are also used herein to refer to a patient's anatomical location from the operator's perspective or entry point, or along an insertion path from an entry point of the system. Thus, a proximal position can refer to a position in the patient closer to the entry point of the device along the insertion path towards the target, and a distal position can refer to a position in the patient further away from the entry point of the device along the insertion path towards the desired location. However, such terms are used to establish a relative frame of reference (or coordinate system) and are not intended to limit the use or orientation of the catheters and / or delivery systems to the specific configurations described in the various embodiments.

[0162] The term "about" refers to a range of values ​​that includes the specified value, and one of ordinary skill in the art would consider such range to be reasonably similar to the specified value. In embodiments (or aspects), about refers to within a standard deviation using measurements generally accepted in the art. In embodiments, about refers to a range that extends to + / - 10% of the specified value. In embodiments, about includes the specified value.

[0163] Although the present specification contains many details, these should not be construed as limiting the scope of what is or may be claimed, but as descriptions of features related to particular embodiments. Features described herein with respect to individual embodiments can be implemented in combination in a single embodiment. Conversely, various features described with respect to a single embodiment can be implemented separately in multiple embodiments or in any suitable subcombination (or subcombination). Furthermore, although previously described as acting in a certain combination and initially claimed as such, one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may be directed to a subcombination or a variation of the subcombination. Similarly, while tasks (or operations) are depicted in the figures in a particular order, this should not be understood as requiring such tasks to be performed in the particular order or sequence shown, or as requiring all of the described tasks to be performed, to achieve desired results. Only a few examples and embodiments have been disclosed. Changes, modifications, and enhancements to the described examples, embodiments, and other embodiments may be made based on what has been disclosed.

[0164] In the above description and in the claims, phrases such as "at least one" or "one or more" may be followed by a list of linked elements or features. Also, the term "and / or" may be included in a list of two or more elements or features. Unless implicitly or explicitly contradicted by the context in which it is used, such terms are intended to mean any of the elements or features of the list individually, or any of the other listed elements or features in combination with any of the listed elements or features. For example, the phrases "at least one of A and B," "one or more of A and B," and "A and / or B" are intended to mean "A alone, B alone, or A and B together," respectively. A similar interpretation is intended for lists containing three or more items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B and / or C" are intended to mean, respectively, "A only, B only, C only, A and B together, A and C together, B and C together, or A and B and C together."

[0165] Use of the term "based on" above and in the claims is intended to mean "based at least in part on," allowing for unrecited features or elements.

[0166] The components of the systems disclosed herein may be packaged together in a single package or separately. The completed package is sterilized using a sterilization method such as ethylene oxide or radiation, labeled, and packed into a box. Instructions for use may also be included in the box or provided via an internet link printed on the label.

Claims

1. A flow diverter having a tubular structure and configured to treat an aneurysm of an intracranial blood vessel, comprising a constrained structure having a first outer diameter and an unfolded structure having a second outer diameter; The inner core member, An elongated shaft including a recessed region near the distal end region, wherein the recessed region is sized to accommodate the tubular structure of the flow diverter in the constrained structure, A non-traumatic distal tip region located distal to the recessed region, wherein the non-traumatic distal tip region has a taper from the first outer diameter of the long shaft to the second outer diameter of the long shaft, and the first outer diameter of the long shaft is larger than the outer diameter of the recessed region, An inner core member including; and An outer restraint sleeve having an inner diameter sized to accommodate the inner core member and the restrained structure of the flow diverter, wherein the outer restraint sleeve can be retracted by at least a distance for deploying the flow diverter; A flow diverter delivery system, including [a specific component].

2. The flow diverter delivery system according to claim 1, wherein the inner diameter of the outer restraint sleeve is sized to match the first outer diameter of the long shaft, thereby reducing the annular space at the tip of the flow diverter delivery system.

3. The first radiopaque marker of the inner core member identifies the most distal end of the inner core member, The flow diverter delivery system according to claim 1, wherein a second radiopaque marker identifies the maximum outer diameter region of the tapered portion for the purpose of delivery to the outer restraint sleeve.

4. The flow diverter delivery system according to claim 1, further comprising the feature of a grip located in the recessed region.

5. The flow diverter delivery system according to claim 4, wherein the grip features include a high friction material, the friction material is configured to contact the flow diverter, and the flow diverter prevents movement of the inner core member relative to the long shaft.

6. The flow diverter delivery system according to claim 4, wherein the grip features include an elastomer material in the recessed area.

7. The aforementioned grip features a silicone-containing flow diverter delivery system according to claim 4.

8. The flow diverter delivery system according to claim 1, wherein the inner core member includes a single central lumen sized to accommodate a guide wire.

9. The flow diverter delivery system according to claim 1, wherein the inner core member does not include a lumen.

10. The flow diverter delivery system according to claim 1, wherein the elongated shaft comprises a material selected to provide a complete axial state while the flow diverter is deployed.

11. The flow diverter delivery system according to claim 1, wherein the long shaft is blade-reinforced or coil-reinforced to provide a complete axial state.

12. The flow diverter delivery system according to claim 1, wherein the outer restraint sleeve is shorter than the inner core member by a length that allows the flow diverter to be fully deployed when the outer restraint sleeve is retracted.

13. The flow diverter delivery system according to claim 1, wherein the outer restraint sleeve includes an inner liner layer with low friction.

14. The flow diverter delivery system according to claim 13, wherein the outer restraint sleeve further includes an outer hydrophilic coating layer in its distal portion.

15. The flow diverter delivery system according to claim 1, wherein the non-traumatic distal tip region of the inner core member has flexibility, shape, taper length, and taper angle configured to deliver the flow diverter delivery system to blood vessels in the brain with or without the use of a guidewire without damaging it.

16. The flow diverter delivery system according to claim 15, wherein the taper length is 0.5 cm to 5 cm.

17. The flow diverter delivery system according to claim 16, wherein the taper angle is 2 to 3 degrees from the center line of the inner core member.

18. The flow diverter delivery system according to claim 1, wherein the first outer diameter is smaller than the inner diameter of the outer restraint sleeve by a difference of 0.010 inches or less.

19. The flow diverter delivery system according to claim 1, wherein the distal end region is formed from a material having a Shore hardness of 35D or less.

20. The flow diverter delivery system according to claim 1, wherein the recessed region has an outer diameter of less than 0.064 inches.

21. The inner diameter of the outer restraint sleeve is 0.070 inches. The flow diverter delivery system according to claim 20, wherein the outer diameter of the outer restraint sleeve is 0.082 inches.

22. The flow diverter delivery system according to claim 21, wherein the flow diverter delivery system is sized to be delivered via a large bore access system having an inner diameter of 0.087 inches to 0.126 inches.

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