Systems and methods for treating vascular disease

Abstract

A diverter includes a self-expanding tubular member having a plurality of expandable units, each of the expandable units having interconnected struts and bridges. The tubular member has a constrained configuration having a first outer diameter of at least 1.0 mm sized for delivery using the shunt delivery system and an expanded configuration having a second outer diameter greater than the first outer diameter. The tubular member has a proximal end region, a distal end region, and a medial region between the proximal end region and the distal end region. When the tubular member is in the expanded configuration, at least the middle region of the tubular member is laser cut to have a material coverage of at least 25%. Related devices, systems, and methods are provided for treating diseases, particularly intracranial aneurysms and cerebral aneurysms, by deploying implantable expandable devices.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Serial Nos. 63 / 338,114, filed on May 4, 2022, 63 / 346,524, filed on May 27, 2022, and 63 / 422,762, filed on November 4, 2022. These disclosures are hereby incorporated by reference in their entirety. Technical Field

[0003] The present technology relates generally to systems and methods for medical devices, and more particularly, to methods for medical device delivery and implantation of stents or flow diverters for treating vascular disease, such as intracranial aneurysms. Background Art

[0004] Intravascular implantation of a stent device, such as a flow shunt, is 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 shunts are particularly useful for treating wide-necked aneurysms that are difficult to exclude by other means, such as embolic coils. The goal of a flow shunt is to be positioned starting from the distal normal segment, crossing the aneurysm, and ending in the proximal normal segment. Flow shunts are designed to have very dense material coverage (approximately 30% when expanded) in order to exclude or limit blood flow into the aneurysm through the aneurysm neck. Excluding blood flow into the aneurysm can reduce or eliminate the risk of aneurysm rupture due to thrombosis at this site over time.

[0005] In general, intravascular implantation of devices in the cerebral and intracranial arteries is performed via smaller sized delivery systems. Access with larger diameter systems is challenging due in part to the tortuosity of the vasculature in the skull and the small size and fragility of the vessels. Navigating these arteries to deliver intravascular implants such as shunts requires catheter systems with excellent flexibility and deliverability, which can be challenging especially with larger diameter catheters. Due to the difficulty in navigating large diameter delivery systems into these anatomical structures, shunts and other intravascular implants are often delivered via microcatheters with an inner diameter of 0.027" or less. Additionally, as is standard for self-expanding stents in larger and more accessible locations, implants are often pushed through these catheters rather than being delivered pre-mounted on the distal end of the delivery system. This approach requires additional steps and wire exchanges, increasing the time and risk of the procedure.

[0006] All currently available shunts are based on a braided wire design to achieve a high percentage of metal coverage to achieve the desired thrombogenic effect. Braided designs can be expanded from diameters deliverable through a 0.027" inner diameter microcatheter to vessels with a maximum desired vessel diameter of up to 5 mm (0.2") while still having 30% metal coverage in the collapsed configuration. Examples include Medtronic PIPELINE, Stryker SURPASS, Terumo FRED, etc. In contrast, stents constructed from laser cut metal tubes (such as Nitinol, stainless steel, and other alloys) cannot achieve the desired at least 30% metal coverage due to geometric constraints.

[0007] Unfortunately, the delivery of braided shunts can be difficult, time-consuming, imprecise, and risky. One problem with braided self-expanding implants, such as braided shunts, is that they may not fully expand to the vessel wall immediately and therefore may move during deployment, resulting in time-consuming and dangerous operations to achieve the desired wall coverage, position, and wall fit. Due to the nature of the braided construction, significant shortening of braided shunts is also a problem during deployment and often results in ineffective coverage of the aneurysm site, and often requires repositioning, manipulation, or may require placement of additional implants. Therefore, coverage of the aneurysm and / or fit of the shunt against the wall is usually not optimal. Poor fit is associated with a higher rate of narrowing or occlusion of the shunt.

[0008] Additionally, due to the difficulty of navigating large diameter delivery systems to the distal carotid anatomy and brain anatomy, devices such as shunts are often delivered via microcatheters of 0.027" ID or smaller. Delivery systems for such devices often include a leading distal guidewire tip, which presents a risk of vessel perforation. Furthermore, braided implants such as shunts that terminate in a wire tip often require a delivery system with an additional distal constraint feature to enable the device to be pushed through the microcatheter. This constraint feature increases the time and complexity of the deployment procedure.

[0009] There is a need for improved shunts that can be delivered via larger caliber access systems that can optimally access the cerebral and intracranial arteries to treat aneurysms at these locations while providing adequate vascular coverage and improved deliverability and expansion characteristics. There is also a need for improved shunt delivery systems that are compatible with these larger caliber access devices and that can accurately and quickly deliver the shunt in a minimum of steps. Summary of the invention

[0010] In one aspect, a shunt is provided, comprising a self-expanding tubular member having a plurality of expandable units, each of the expandable units having interconnected struts and bridges. The tubular member has a constrained configuration and an expanded configuration, the constrained configuration having a first outer diameter of at least 1.0 mm sized for delivery using a shunt delivery system, the expanded configuration having a second outer diameter greater than the first outer diameter. The tubular member has a proximal end region, a distal end region, and a middle region located between the proximal end region and the distal end region. When the tubular member is in the expanded configuration, at least the middle region of the tubular member is laser cut to have at least 25% material coverage.

[0011] The interconnected struts and bridges of each expandable unit may include two pairs of struts, each of the two pairs of struts having an outer edge. The outer edge of a first strut in a first pair of struts may be interconnected with the outer edge of a second strut in the first pair of struts by one of the bridges. The first strut in the first pair of struts may be connected to the first strut in the second pair of struts at a center bend, and the second strut in the first pair of struts may be connected to the second strut in the second pair of struts at a center bend. The circumferential height from the center bend of the first pair of struts to the outer edge of the first pair of struts is Y, and the axial distance from the center bend of the first pair of struts to the outer edge of the first pair of struts is X, and wherein 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 of the first strut may be between 1 and 5. Each pair of struts may be arranged parallel to each other and spaced apart from each other by an axial distance, thereby defining a V-shaped opening of the expandable unit. The two pairs of struts may be interconnected to form a peak on the first end of the expandable unit and a corresponding valley on the second end of the expandable unit. A plurality of expandable cells may be arranged in a circumferential ring and each peak in a circumferential ring of expandable cells may be circumferentially aligned with each peak of a circumferential ring of adjacent expandable cells. A bridge may connect a peak of an expandable cell of a first circumferential ring to a valley of an expandable cell of an adjacent second circumferential ring.

[0012] The middle zone may have characteristics different from one or both of the proximal end zone and the distal end zone. The middle zone may have 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 material coverage less than the material coverage of the middle zone. When the tubular member is in an expanded configuration, the material coverage of the middle zone may be between 25% and 35%, and the material coverage of the proximal end zone and the distal end zone may be less than the material coverage of the middle zone. At least one of the proximal end zone, the middle zone, and the distal end zone may include at least one radiopaque marker. The length of the shunt in the constrained configuration may differ from the length of the shunt in the expanded configuration by less than 1%. The length of the shunt in the constrained configuration may differ from the length of the shunt in the expanded configuration by less than about 5%. The length of the shunt in the constrained configuration may differ from the length of the shunt in the expanded configuration by less than about 10%.

[0013] The first outer diameter can be between 1.5mm and 2.5mm, and wherein the second outer diameter is between 2.0mm and 6.0mm. The length of the shunt in the constrained configuration can be between 10mm and 35mm. A plurality of expandable units of the tubular member can be arranged into 10 and 50 circumferential rings. The spacing of the middle zone can be between about 0.25mm and 0.40mm, and the spacing corresponds to the length of the bridge of the expandable unit in the middle zone. The spacing of one or both of the proximal end zone and the distal end zone can be about 0.45mm to 0.75mm, and the spacing corresponds to the length of the bridge of the expandable unit in the proximal end zone or the distal end zone. A plurality of expandable units can form a row, and the row extends parallel to the longitudinal axis of the tubular member between the proximal end and the distal end of the tubular member, and the row of expandable units is aligned in a peak-to-valley manner. The tubular member can include between 4 and 10 rows.

[0014] At least the distal end region may include a track formed by a bridge piece of a plurality of expandable units interconnected in a row. The track may enable the distal end region to be re-inserted in the delivery system after at least a portion of the distal end region is deployed. One or both of the proximal end region and the distal end region may include a braided structure or a textile structure. The interconnected pillars may be connected by a plurality of V-shaped hinges. The line connecting the radially adjacent hinges may pass through at least 4 units in the middle region. The line connecting the radially adjacent hinges in the proximal and distal regions may pass through fewer units than in the middle region. The bridge piece located in the middle region may be shorter than the bridge piece located in the distal end region and the proximal end region. The pillars in the middle region, the distal end region, and the proximal end region may be substantially the same in length and configuration. The bridge piece may be parallel to the central axis of the shunt.

[0015] In a related aspect, a method for treating an intracranial aneurysm or a cerebral aneurysm is provided, the method comprising advancing a catheter system through a base sheath toward an intracranial or cerebral blood vessel having an aneurysmal segment. The catheter system comprises: an inner catheter having a tubular elongated body having a single lumen and a flexible distal tapered end region; and an outer catheter having a catheter lumen and a distal end. The method comprises: positioning the tapered end region of the inner catheter distal to the distal end of the outer catheter; crossing the blood vessel segment having an aneurysm with at least a portion of the tapered end region of the inner catheter; advancing the outer catheter over the inner catheter and positioning the distal end region of the outer catheter across the lesion; withdrawing the inner catheter from the catheter lumen and keeping the outer catheter in place across the aneurysm; advancing a shunt delivery system including a shunt through the catheter lumen to the distal end region of the outer catheter; withdrawing the outer catheter while keeping the shunt delivery system in place; and deploying the shunt across the segment having the aneurysm.

[0016] In a related aspect, a method for performing a medical procedure at a treatment site in a patient's brain is provided, the method comprising positioning a system of a device in a propulsion configuration. The system of the device comprises: a catheter having a catheter lumen, an inner diameter, and a distal end; and an inner member sized and shaped to slide 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 second outer diameter that is smaller than the first outer diameter, and the inner member transitions from a proximal end of the inner member to a distal end of the inner member in flexibility, the distal end of the inner member being more flexible than the distal end of the catheter. When positioned in the propulsion configuration, the inner member coaxially extends through the catheter lumen until the distal portion of the inner member is positioned distal to the distal end of the catheter. The method comprises: when the system of the device is positioned in the propulsion configuration, advancing the catheter and the flexible inner member to a target location of an access point; positioning the catheter at a treatment site that includes an aneurysm; removing the inner member from the patient; and treating the aneurysm by the catheter. The treating step may include delivering a flow shunt to the aneurysm via a catheter.

[0017] In a related aspect, a shunt delivery system is provided, the shunt delivery system comprising: a shunt having a tubular structure and configured to treat an aneurysm in an intracranial blood vessel, the shunt having a constrained configuration having a first outer diameter and an expanded configuration having a second outer diameter; an inner core member comprising an elongated shaft having a recessed region near a distal end region of the elongated shaft, the recessed region being sized to receive the tubular structure of the shunt when the shunt is in the constrained configuration; and an atraumatic distal tip region located distal to the recessed region. The distal tip region has a taper from the first outer diameter of the elongated shaft to the second outer diameter of the elongated shaft. The first outer diameter of the elongated shaft is greater than the outer diameter of the recessed region. The system comprises an outer restraining sleeve having an inner diameter sized to receive the inner core member and the shunt in the constrained configuration. The outer restraining sleeve can be retracted at least a distance to deploy the shunt.

[0018] The inner diameter of the restricting sleeve can be matched to the first outer diameter size of the elongated shaft to reduce the annular space at the leading end of the shunt delivery system. The distal end region can include at least one radiopaque marker at the distal end. The distal end region can include a second radiopaque marker positioned to identify the tapered portion.

[0019] In a related aspect, a shunt with a self-expanding tubular member is provided, the self-expanding tubular member having a proximal end, a distal end and a longitudinal axis. The tubular member has a constrained configuration and an expanded configuration, the constrained configuration having a first outer diameter sized for delivery, the expanded configuration having a second outer diameter greater than the first outer diameter. The tubular member comprises a plurality of expandable units, each unit having interconnected struts and bridges arranged in a circumferential ring. The circumferential ring forms a row of expandable units extending parallel to the longitudinal axis between the proximal end and the distal end of the tubular member, the row of expandable units being nested in a peak-to-valley manner. The tubular member has a proximal end region near the proximal end of the tubular member, a distal end region near the distal end of the tubular member, and a middle region between the proximal end region and the distal end region. At least the distal end region comprises at least one track formed by the bridges of each circumferential ring of the expandable units in the interconnected single row.

[0020] The at least one track can enable recapping of the distal end region in the delivery system after the distal end region is at least partially deployed from the delivery system.At least a mid-region of the tubular member can be laser cut to have at least 25% material coverage when the tubular member is in the expanded configuration.

[0021] In a related aspect, a flow diverter is provided, the flow diverter being configured to expand from a constrained state to an expanded state. The flow diverter comprises: a first tube of a superelastic material formed by a plurality of cells having a first material coverage; and a second tube of a superelastic material formed by a plurality of cells having a second material coverage. The second tube is positioned inside the first tube so that when the flow diverter is in the expanded state, an overlap of the plurality of expandable cells of the first tube and the plurality of expandable cells of the second tube forms a third material coverage greater than the first material coverage and the second material coverage.

[0022] The second tube may be locked in place inside the first tube by a feature in the cut pattern of at least one of the first tube and the second tube. The feature may include a slot in the first tube or the second tube and a tab configured to protrude into the slot to lock the first tube and the second tube together. The feature may include a hole in the first tube or the second tube and a malleable disc configured to be inserted into the hole to lock the first tube and the second tube together. At least one of the first tube and the second tube may be non-woven and laser cut. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other aspects will now be described in detail with reference to the following drawings. In general, the drawings are not drawn in absolute or relative proportions, but are intended to be illustrative. Likewise, the relative positions of features and elements may be modified for the purpose of clarity of illustration.

[0024] Figure 1A is an implementation of a cutting tube shunt in a collapsed delivery configuration;

[0025] Figure 1B is in extended configuration Figure 1A The shunt;

[0026] Figure 1C is in extended configuration Figure 1B A shunt of FIG. 1 , showing a plan (expanded) view of a device pattern;

[0027] Figure 1D It is a related implementation of the cut tube splitter;

[0028] Figure 1E yes Figure 1D A shunt of FIG. 1 , showing a plan (expanded) view of a device pattern;

[0029] Figure 1F is in the cutting configuration Figure 1D The splitter, showing details of the cutting pattern;

[0030] Figure 2A Shows Figure 1C a unit of a segment of a flow divider;

[0031] FIG. 2B to FIG. 2D shows different spacings Figure 1C The units of different sections of the diverter;

[0032] Figure 3 Additional details of the implementation of the cut tube splitter are shown;

[0033] FIG. 4A to FIG. 4C Details of the attachment mechanism between the two layers of a double-layer shunt are shown;

[0034] FIG. 5A to FIG. 5B Details of an alternative attachment mechanism between the two layers of a double-layer shunt are shown;

[0035] FIG. 6A to FIG. 6B The implementation of a double-layer shunt is shown;

[0036] Figure 7 The implementation of the composite splitter is shown;

[0037] Fig. 8A A shunt and components of a delivery system for the shunt are shown;

[0038] Figure 8B The assembly into the delivery configuration is shown Fig. 8A diverters and delivery systems;

[0039] Figure 8C shows a diagram where the splitter is partially deployed Figure 8B diverters and delivery systems;

[0040] Fig.9A An access catheter system for accessing a treatment site in an artery is shown;

[0041] Fig. 9B Shown assembled for use Fig.9A Access catheter system;

[0042] Fig. 10A It is along Fig.9A A detailed view of the distal end region of the catheter advancement element taken through circle CC;

[0043] Fig. 10B Is located in Fig. 10A a detailed view of a distal end region of a catheter advancement element of a guidewire within an inner lumen of the catheter advancement element;

[0044] Fig.11A An assembled catheter system for accessing an intracranial aneurysm is shown, wherein a base sheath is positioned in the internal carotid artery (ICA), an outer catheter is advanced in the distal ICA, and an inner catheter spans the vessel at the aneurysm site;

[0045] Fig. 11B Shown is the advancement of Fig.11A the outer catheter and the withdrawn inner catheter;

[0046] Fig. 11C shows a flow shunt delivery system advanced across an aneurysm and the outer catheter withdrawn;

[0047] Fig.11D shows a withdrawn shunt restraining sheath and a shunt deployed across an aneurysm;

[0048] Fig. 12A is a plan (expanded) view of a related implementation of a cut tube splitter in a retracted state;

[0049] Fig. 12B The image taken at circle A is shown. Fig. 12A Detailed cross section of the flow divider;

[0050] Fig.13 is a plan (expanded) view of a related implementation of a cut tube splitter in a retracted state;

[0051] Fig.14 A related implementation of a cut tube splitter with flared ends.

[0052] It should be understood that the drawings are for illustration purposes only and are not drawn to scale. The drawings are intended to illustrate dimensions including metal coverage percentages. The drawings are not drawn to absolute or relative scale. It should be understood that the devices described herein may include features that are not necessarily depicted in every figure. DETAILED DESCRIPTION

[0053] Shunts and delivery systems and methods compatible with large-bore access systems are described herein. The devices, systems, and methods utilize large-bore access to provide improvements over existing braided shunts and associated microcatheter-based delivery systems, enabling more precise, safe, and rapid treatment of aneurysms. These devices and systems can be delivered by any large-bore neurovascular access system. An improved large-bore access system is also described that facilitates speed, safety, and ease of access to intracranial and cerebral arteries to implant shunts at their intended locations, even despite challenges in navigation.

[0054] The phrase "access catheter" as used herein means that such catheters can be used for purposes other than or in addition to access, such as delivering fluids to a treatment site or as an aspiration catheter. Alternatively, the access systems described herein can also be used to access other parts of the body outside of the vasculature. Similarly, where the working device is described as an expandable brain treatment device or shunt, other interventional devices can be delivered using the access and delivery systems described herein. As used herein, an "aneurysm" refers to a bulge from a weak section of a blood vessel wall. A "cerebral aneurysm" or "intracranial aneurysm" refers to an aneurysm in a blood vessel of the brain.

[0055] Shunt

[0056] The shunt disclosed herein greatly improves deployment and performance compared to current braided shunts. The shunt can be a self-expanding cutting tube implant, which, unlike a braided wire tube, expands to full diameter much faster and more accurately. Since the cutting tube construction does not have wire ends like a braided implant, there is no need to constrain or cover the distal end of the implant. The cutting tube shunt described herein also does not experience significant perspective foreshortening like a braided wire stent. The cutting pattern can be designed to utilize a single layer of material, rather than a braid with a cross-wire surface, to achieve wall conformation and coverage sufficient to achieve shunt, prevent or prevent blood flow into the aneurysm and / or aneurysm isolation, thereby producing a smoother and less thrombotic inner surface.

[0057] Figures 1A to 1C and Figures 1D to 1F Implementations of a cut tube shunt 700 are shown. In each implementation, the shunt 700 is a generally tubular member or element that is non-braided and has an open distal end 707 that is distal to the user during advancement through a blood vessel and an open proximal end 709 that is closer to the user during advancement through a blood vessel. A longitudinal axis extends between the distal end 707 and the proximal end 709. Figure 1A Shunt 700 is shown in a constrained configuration having a first outer diameter OD1 and a first length L1. The first outer diameter OD1 accommodates insertion of shunt 700 into the vasculature and navigation through the vasculature to a treatment site. Figure 1B The shunt 700 is shown in an expanded configuration having a second outer diameter OD2 and a second length L2. Upon reaching the treatment site, the shunt 700 is deployed and expanded to the second outer diameter OD2. Thus, OD2 is greater than OD1.

[0058] The constrained outer diameter OD1 of the shunt 700 can be approximately 0.89 mm (0.035") to approximately 3 mm (0.118"), preferably approximately 1.5 mm (0.06") to 2.5 mm (0.10"), or approximately 1.60 mm. This constrained outer diameter OD1 is relatively large compared to the constrained outer diameter of conventional braided shunts. This is achieved through the larger caliber access system described herein, which is configured to reach a distal site to deploy the shunt. The deliverability of the large caliber access system, which will be described in more detail below, enables the delivery of larger constrained outer diameter OD1 shunts, and also enables the shunt to be designed to have greater material coverage when expanded.

[0059] Depending on the anatomical requirements, the expanded outer diameter OD2 of the shunt 700 can be from about 2 mm (0.08") to about 6 mm (0.24"), preferably between about 2.5 mm (0.10") and about 5 mm (0.2"). When expanded, the shunt 700 is preferably suitable for blood vessels with a diameter of up to 5 mm. The shunt length L1 can also be manufactured according to the anatomical requirements. For example, the length L1 of the shunt before expansion can vary from 10 mm to 50 mm, including any size between 10 mm and 35 mm and preferably from 10 mm to 35 mm.

[0060] The length L2 of the expanded shunt can be within the same range. The cut tube shunt 700 described herein undergoes minimal shortening when deployed from a constrained state to an expanded state in a vessel. This provides an advantage over braided wire shunts that shorten significantly when deployed. When expanded from about 1.6 mm to about 4.0 mm, Figures 1A to 1C and Figures 1D to 1F The shunt design shown in the foreshortened is less than 10%, less than 5%, or about 1% or less. For example, the constrained length L1 can be about 20.7 mm and the expanded length L2 can be about 20.5 mm, which is less than about 1% shortening. In contrast, when expanded to 4 mm, the braided stent is shortened by about 50% (see Instructions for Use of Surpass Evolve Flow Diverter System; Stryker Neurovascular). This extreme shortening of the braided shunt requires precise placement of the distal end to ensure complete coverage of the target segment. The distal end must extend from a portion of the normal vessel segment away from the aneurysm so that the middle segment of the shunt can cross the aneurysm neck and be positioned to the normal vessel on the proximal side of the aneurysm. Especially in curved or tortuous anatomical structures, the extreme shortening of the shunt may result in "missed" deployment. If the aneurysm neck is very large, or if the vessel tapers at the aneurysm neck, the final length and position are even more unpredictable.

[0061] When the tubular member is in the expanded state, the shunt 700 can achieve a material coverage suitable for treating an aneurysm. The material coverage (also referred to herein as material density) can vary, but is generally between about 25% and 35% material coverage (+ / - 5%). As used herein, "material coverage" means the surface area of ​​the outer surface of the shunt divided by the surface area of ​​the lumen within the vessel. The material of the shunt provides material coverage, which is the inverse of the porosity of the shunt, and the material coverage is a function of the amount of open space when the shunt is expanded.

[0062] Figure 1C and Figure 1E 765. The shunt 700 includes a plurality of repeating units 750 arranged in a plurality of circumferential rings 760 that repeat between the proximal end 709 and the distal end 707 along the axial length of the shunt 700. The units 750 are radially and circumferentially aligned with adjacent units 750 to form a repeating zigzag pattern. The units 750 are axially aligned so that they are nested within each other to form a plurality of axial rows 765. Thus, the number of axial rows 765 is controlled by the number of units 750 around the circumference of the shunt within a single ring 760.

[0063] The flow diverter is self-expanding and may be a tubular member having a circumferential ring of expandable cells 750. Each of the cells 750 comprises interconnected struts and axial bridges. Figure 2A An arrangement comprising interconnected struts 751 and axial bridges 752 is shown. Figure 1A and Figure 1DA single unit 750 of the diverter 700. Each unit 750 can be formed by four struts 751, wherein the first two of the four struts 751 are connected in a V shape at a first center bend or hinge, and the last two of the four struts 751 are connected in a V shape at a second center bend or hinge. The center bend (also referred to as the hinge herein) is aligned and spaced apart by a distance so that the pair of struts 751 are spaced apart by a distance away from each other. In other words, each unit combines two V-shaped struts 751, each V-shaped strut comprising a center bend and two straight arms, which protrude in opposite directions at a certain angle away from the center bend. The struts 751 in each unit 750 are arranged so that the center bends are nested at a distance. The angles of the center bends can be equal, so that the struts 751 are positioned parallel to each other, thereby defining a V-shaped opening 754 for each unit 750. Regardless of whether the unit 750 is considered to have two V-shaped struts or four struts arranged in two V-shapes, the plurality of struts 751 form a zigzag pattern around the circumference of the diverter 700. Additionally, the zigzag pattern of struts 751 need not be limited to V-shapes and may include "W-shaped," "Z-shaped," or "M-shaped" strut patterns as well as other strut patterns, such as diamond shapes or patterns forming open or closed cell structures.

[0064] Each expandable unit 750 having a V-shaped opening 754 forms a valley 753 that opens toward the proximal end 709 of the shunt 700 and a peak 757 that protrudes toward the distal end 707 of the shunt. The peak 757 is formed by a center bend 758 between two struts 751 and the valley 753 is formed by the center bend 758 of the other two struts 751. A first pair of struts 751 can be connected to each other at a first edge of the unit 750 by a first bridge 752, and a second pair of struts 751 can be connected to each other at an opposite edge of the unit 750 by a second bridge 752. A third bridge 752 can connect the peak 757 of one unit 750 to the valley 753 of an adjacent unit 750, which will be described in more detail below.

[0065] The V-shaped openings 754 formed by struts 751 and connecting bridges 752 can be repeated around the circumference of the shunt 700 to form one of a plurality of circumferential rings 760. The pattern of cells 750 can be repeated multiple times along the axial length of the shunt 700 to define a number of rings 760. Depending on the desired overall axial length and cell density, the shunt 700 can include 10 to 50 rings 760, and any number of zigzag V-shaped cells 750 therebetween, depending on the overall length of the shunt 700 and the needs of the anatomical structure being treated. The pattern of cells 750 can be repeated multiple times circumferentially around the tubular structure of the shunt 700 to define a number of rows 765. The number of rows 765 can vary depending on the desired size of the shunt 700. For typical sizes for intracranial aneurysms and cerebral aneurysm treatment, the number of rows 765 can be from 4 to 10, preferably about 6. Thus, the number of struts 751 around the circumference of the diverter (which is twice the number of peaks 753 because four struts 751 are paired to form a single unit 750 with peaks 753) can be about 8 to 20, preferably about 12. Figure 1C and Figure 1E A row 765 is shown containing cells 750 with peaks 757 of cells 750 pointing toward distal end 707 of shunt 700 and valleys 753 of cells 750 open toward proximal end 709 of shunt 700. With this arrangement, a single ring 760 contains six rows 765 of full cells 750.

[0066] Still reference Figure 1C as well as Figure 1E , a ring 760 of a unit 750 can be connected to an adjacent ring 760 via a bridge 752. The bridge 752 connects the peak 757 of a first unit 750 of a first ring 760 to the valley 753 of an adjacent unit 750 of a second ring 760. The peak-to-valley connection allows each ring 760 of the V-shaped unit 750 to nest closely with each other when in the collapsed configuration and also maintain high material coverage when deployed to the expanded configuration. The close nesting and high material coverage when deployed are also a function of the long struts 751 and the relatively short bridges 752 that connect them peak to valley.

[0067] The axial length of the bridges 752 determines the axial spacing between the struts 751 in the unit 750, which is also referred to herein as the pitch P (see Figure 2A ). This axial length and axial spacing is a factor that controls the material coverage of the diverter and the porosity of the diverter, the porosity being the inverse of the material coverage. The material of the struts 751 provides the material coverage, and the openings 754 between the struts 751 and the openings 756 between the cells 750 form the open space of the diverter and are the porosity.

[0068] FIG. 2A to FIG. 2D A single unit 750 is shown formed of interconnected struts 751 and axial bridges 752. As described above, each of the units 750 can be formed of four struts 751. The four struts 751 can be grouped in pairs. Each strut in the two pairs of struts can include an outer edge 755. The outer edge 755a of the first strut 751a in the first pair of struts is interconnected with the corresponding outer edge 755b of the second strut 751b in the first pair of struts through one axial bridge 752a. The first strut 751a in the first pair of struts is connected to the first strut 751c in the second pair of struts at a center bend 758a. The second strut 751b in the first pair of struts is connected to the second strut 751d in the second pair of struts at a center bend 758b. The outer edge 755c of the first strut 751c in the second pair of struts is interconnected with the corresponding outer edge 755d of the second strut 751d in the second pair of struts through another axial bridge 752b. The third bridge 752c protrudes distally from the central bending portion 758a.

[0069] Still reference FIG. 2A to FIG. 2D , Y is the circumferential height occupied by a single strut 751 from the central bend 758 near 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 bend 758 near the peak 757 of the cell 750 to the outer edge 755 of the cell 750. The strut length is approximately equal to the diagonal of the rectangle defined by X and Y. The ratio of the strut length in the expanded configuration to the circumferential height Y of the strut 751 controls the angle at which the strut 751 protrudes away from the central bend 758 near the peak 757. This ratio can be 1 to 5, 1 to 3, and preferably around 2. Each central bend 758 (see Figure 2D The ratio of the radius R of the peak 757 to the circumferential height Y of the strut in the constrained configuration controls the radius of curvature of each peak 757. This ratio can be in the range of 2 to 10, preferably around 6. Figure 2A The strut width in is shown as WS and the bridge width is shown as WB. The strut axial height X and circumferential height Y, the strut width WS, the axial bridge length P and the bridge width WB are selected to meet certain criteria.

[0070] The bridge 752 is shown as a connecting member that is substantially straight and parallel to the longitudinal axis (i.e., the central axis) of the shunt. The bridge 752 connects adjacent peaks and valleys to form a unit 750. However, the bridge 752 does not need to be straight, and may also be curved or angled relative to the longitudinal axis of the shunt. The bridge 752 may also be connected at a position other than the peak to the valley, such as being connected to the middle of the strut 751 or the point where the strut 751 meets the hinge (i.e., the central bend 758). In addition, the bridge 752 is shown to be aligned in the longitudinal direction and connect every second pair of struts. However, the bridge does not need to be aligned axially at all, or may be aligned axially at every 3rd, 4th, 5th or other number of strut pairs or units. The term "axial" used herein means in the direction of the length of the tubular member along the shunt, but does not require that the direction be parallel to the longitudinal axis of the shunt. For example, an "axial bridge" includes a bridge that is parallel to the central axis of the splitter, and also includes a bridge that is angled, stepped, or curved relative to the central axis of the splitter.

[0071] When in such Figure 1A When in the collapsed configuration shown in FIG. 1 , the struts 751 of each unit 750 are close to touching or touching at least one area of ​​each unit 750. The spacing of the struts 751 can be selected so that the struts 751 do not overlap each other at the constrained diameter of OD1. The area of ​​the V-shaped opening 754 between the struts 751 of each unit 750 can be reduced to almost zero, so that only the area of ​​the V-shaped opening 754 near the center bend of the strut pair or between the valley 753 and the peak 757 of each unit 750 remains. When in the collapsed configuration shown in FIG. Figure 1B In the expanded configuration shown in FIG. 7 , the struts 751 of each unit 750 may be expanded away from each other so as to no longer be in contact. Figure 1F It is intercepted at circle A. Figure 1E Detailed view of FIG. Each strut 751 in this region is spaced apart from an adjacent strut by a distance as narrow as the strut width. The spacing between struts 751 of unit 750 provides high material coverage of the diverter when in the expanded configuration. When at the expanded diameter of OD2, diverter 700 preferably has between 25% and 35% material coverage.

[0072] Table 1 below provides Figures 1A to 1CExample parameters of the shunt 700 shown in , including parameters such as the spacing P1 of the center portion of the shunt. The material coverage in the expanded configuration can be between about 25% and about 35%. The outer diameter OD1 in the contracted configuration can be between about 1.5mm and about 2.5mm. The outer diameter OD2 of the shunt in the expanded configuration can be between about 2mm and about 6mm. The length L1 of the shunt in the contracted configuration and the length L2 of the shunt in the expanded configuration can be between about 10mm and about 50mm. The length change between the contracted configuration and the expanded configuration can be less than 10%, less than 5% and less than 1%. The number of rows 765 in the shunt can be between about 4 and about 10 and the number of rings 760 can be between about 10 and about 30. Depending on the desired material coverage, the spacing P of each unit 750 in the densest part of the shunt can be between about 0.25mm and about 0.75mm. The circumferential height Y of a single strut may be between about 0.5 mm and about 1.5 mm, and the axial distance X may be between about 1.0 mm and about 2.0 mm. The bridge width WB may be between about 0.025 mm and about 0.09 mm. The strut width Ws may be between about 0.025 mm and about 0.09 mm.

[0073] Table 1

[0074]

[0075] Other combinations of parameters may be selected to meet the criteria described above. Other features, such as strut radius, wall thickness, may also be selected so that the diverter 700 obtains desired physical properties. For example, the strut radius may be about 0.05 mm to 0.10 mm, preferably about 0.07 mm, and the wall thickness may be about 0.05 mm to about 0.09 mm, preferably between 0.065 mm and 0.075 mm.

[0076] The shunt 700 can be designed to have a consistent pattern along its length or can vary in pattern over its length. Further, the shunt 700 can have the same cell pattern along its entire length, but the spacing of the cells varies depending on the needs of the anatomical structure. The difference in pattern along the length of the shunt 700 can be selected to vary the strength and material coverage percentage for optimal performance. The variation in pattern can form different zones along the length of the shunt. Again referring to Figure 1C, the ring 765 of cells 750 within the central portion of the diverter 700 can have a pitch P that forms a dense central diverter zone 701. The central diverter zone 701 of the diverter 700 can have a maximum material density in order to divert flow away from anatomical structures (such as aneurysms) outside the zone. The diverter 700 can have intermediate density zones 702, 704 on either side of the central diverter zone 701. The intermediate density zones 702, 704 can have a lower material density or material coverage than the central zone 701. The diverter 700 can have two end zones 703, 705 on either side of the intermediate density zones 702, 704, respectively, which have a lower material density than the intermediate density zones 702 and 704. The material density or material coverage of the zones can be a function of the pitch P or the axial spacing between adjacent struts 751, and the pitch P is a function of the length of the bridge. When the tubular member is in the expanded configuration, at least the middle region of the tubular member is laser cut to have a material coverage of at least about 25%. The middle region can have characteristics different from one or both of the proximal end region and the distal end region. The middle region can have a greater material coverage than one or both of the proximal end region and the distal end region. One or both of the proximal end region and the distal end region can be laser cut to have a material coverage less than the material coverage of the middle region. Compared to the middle region, one or both of the proximal end region and the distal end region can include a different structure, such as a braided structure or a textile structure.

[0077] The lengths of the different zones can also vary. The middle shunt zone 701 can have a length Lc designed to be longer or shorter in order to match the needs of the anatomical structure being treated. As an example, a shunt with an overall length L2 of approximately 20 mm can be combined with a middle shunt zone 701 with a length Lc between 10 mm and 15 mm. The shunt can have a variety of lengths L2, expanded diameters OD2, and middle zone lengths Lc.

[0078] The middle diversion area 701 may be formed by a plurality of rings 760 that can be closely nested with each other even after expansion due to the relatively short length of the bridges 752 connecting the peaks 757 and valleys 753 of the cells 750 in adjacent rings 760. The length of the bridges 752 controls the spacing of the cells 750. The greater the length of the bridges 752, the greater the spacing or interval between the struts 751 of the cells 750, and the lower the material density. Figure 2B A cell 750 is shown having a distal end region 703 or a proximal end region 705 with a pitch P3. Figure 2C A cell 750 is shown having a transition density region 702 or an intermediate density region 704 with a pitch P2. Figure 2DA cell 750 is shown with a middle shunt zone 701 having a spacing P1. The spacing P3 of the end zones 703, 705 can be the largest and the spacing P1 of the middle shunt zone 701 can be the smallest, with the spacing P2 of the intermediate density zones 702, 704 in between, such that P3>P2>P1. The lower material coverage of the zones outside the middle zone 701 allows the shunt 700 to effectively treat aneurysms and prevent blood from flowing into the diseased part of the vasculature in the middle zone while preventing the shunt 700 from occluding branch vessels (e.g., near the end zones). In an implementation, P1 or axial spacing within the middle shunt zone 701 can be approximately 0.25mm to 0.40mm, P2 or axial spacing within the middle shunt zones 702, 704 can be approximately 0.35mm to 0.050mm, and P3 or axial spacing within the end shunt zones 703, 705 can be approximately 0.45mm to 0.75mm. The length of the bridges in the middle zone 701, the intermediate zones 702, 704, and the distal end zones 703 / proximal end zones 705 may vary. The length of the bridges in the middle zones 702, 704 may be at least 120% of the length of the bridges in the middle zone 701. The length of the bridges in the distal end zones 703 / proximal end zones 705 may be at least 125% of the length of the bridges in the middle zone 701, preferably about 150% to 300% (i.e., 1.5x to 3x) of the length of the bridges in the middle zone 701.

[0079] The strut width Ws, strut circumferential width Y, and strut axial length X can be the same in all three zones, or can vary from one zone to another to change the pattern density and physical properties between zones. The distal zone 703 and the proximal zone 705 can have one or two axial repeats or rings 760, the intermediate zones 702, 704 can have two or three axial repeats or rings 760, and the middle zone 701 can have 10 to 30 axial repeats or rings 760.

[0080] In a related implementation, the flow diverter 700 may have different cut patterns at either end to optimize deployment characteristics, resulting in an overall asymmetric design. Fig. 12A A flow divider 700 is shown having a central flow divider region 730 having a flow divider region similar to Figure 1C The cutting pattern of the middle diverter region 701 of the middle diverter 700. Figure 1C Compared to the shunt 700 shown in FIG. Fig. 12AThe proximal end region 733 and the distal end region 734 of the shunt 700 have a more traditional "stacked wave" pattern of a conventional stent. The pattern of the end regions 733 and 734 can be similar to an intracranial stent that is not designed for shunts but rather for supporting coiling procedures similar to, for example, the Stryker NEUROFORM ATLAS stent. These stents are known to be easier and more accurately deployed than braided shunts. Figure 1C Compared to the shunt shown in FIG. 1 , the “stacked wave” pattern has fewer connections between segments and therefore opens faster during deployment. In other words, when there is less exposed expandable length, Fig. 12A The shunt 700 of the embodiment of the present invention achieves a fully expanded diameter and can therefore be "anchored" to the wall during most of the deployment steps. The first circumferential ring in the proximal end region 733 can have a peak that connects to the corresponding valley of the second circumferential ring in the proximal end region 733, thereby forming a completely closed unit at the outermost area of ​​the proximal end region 733. Similarly, the first circumferential ring in the distal end region 734 can have a valley that connects to the corresponding peak of the second circumferential ring in the distal end region 734, thereby forming a completely closed unit at the outermost area of ​​the distal end region 734. Therefore, the first two outer rings of the distal end region 734 and the proximal end region 733 can be completely closed diamond-shaped units.

[0081] Still reference Fig. 12A , moving inwardly toward the middle area 730, each of the proximal end area 733 and the distal end area 734 can have alternating larger rings and smaller rings. An inner circumferential ring in the proximal end area 733 can be larger than the first two circumferential rings forming the rhombus unit, and also larger than the next circumferential ring located inwardly from the most proximal end area of ​​the device. Similarly, an inner circumferential ring in the distal end area 734 can be larger than the first two circumferential rings forming the rhombus unit, and also larger than the next circumferential ring located inwardly from the most distal end of the device. This pattern can continue so that both the proximal end area 733 and the distal end area 734 have alternating larger circumferential rings and smaller circumferential rings moving inwardly toward the middle area 730. Larger circumferential rings can have peaks and valleys with a large height and a large circumferential span. Every other larger peak is connected to every four smaller valleys of the adjacent smaller circumferential ring. This causes every other peak of the larger circumferential ring to be retained without being connected to the adjacent circumferential rings, so as to form an open cell design. Circumferential rings on both the proximal and distal sides of the middle region 730 may meet peak to valley, wherein adjacent peak to valley portions of the circumferential rings of the middle region 730 form closed diamond-shaped cells at either end.

[0082] Even within the end regions 733 and 734, the strut pattern can be varied to optimize the balance between device flexibility and radial strength. Fig. 12B ( Fig. 12A As most easily seen in detail A), some sections may have thinner struts 742 with smaller "wavelengths" while adjacent sections may have wider struts 744 with larger "wavelengths". In an embodiment, the thinner struts have a width of 0.025" (approximately 0.64 mm) and 12 waves around the circumference, while the thicker struts 744 have a width of 0.047" (approximately 1.2 mm) and 8 waves around the circumference. Other strut sizes and frequencies may also meet design requirements.

[0083] Further variations can be made along the length of the diverter 700. For example, Fig.13 730 and 734. The plan view of the shunt 700 having different strut patterns from one end of the shunt 700 to the other end. The shunt 700 can include a first transition section 735 between the middle shunt region 730 and the distal end region 734. The shunt 700 can include a second transition section 735 between the middle shunt region 730 and the proximal end region 733. The transition section 735 can have a pattern density between the dense middle shunt region 730 and the more open pattern density of the end regions 733, 734. The transition section 735 can have a 24-strut ring combined between the middle shunt region 730 and the end regions 733, 734. The transition nested struts can provide increased spacing in the proximal and distal regions of the middle shunt region 730.

[0084] The design of the distal end may be different from the design of the proximal end of the shunt. Fig.13 As shown in FIG, the distal end region 738 of the shunt 700 formed by the outermost two circumferential rings has an "open cell" design, in which the struts of the terminal row are only attached to the struts of the adjacent row every 3 waves. In other words, the larger circumferential ring can have peaks and valleys with greater height and greater circumferential span, so that every other larger peak is connected to every fourth smaller valley of the adjacent smaller circumferential ring, resulting in every other peak of the larger circumferential ring remaining unconnected to the adjacent circumferential ring to form an open cell design. In contrast, the proximal end region 737 of the shunt 700 formed by the outermost two circumferential rings has a "closed cell" design, in which each wave is attached to the adjacent strut peaks to the valleys to form a diamond-shaped unit. The open cell nature of the distal end region 738 will make the radial expansion of the shunt 700 during deployment faster because the end rows of struts are less connected to the adjacent rows. The asymmetry between the distal end and the proximal end can be achieved by having one end with a diamond shape and the other end with a single 24-strut ring.

[0085] The width, length, number, and location of the axial connecting struts may vary, such as the axial struts 746 ( Fig. 12B), or the axial struts 752 in the middle section of the diverter 700 ( Figure 1F ) to further optimize device flexibility with longitudinal stability. The main disadvantage of braided shunts is that they are prone to shortening during expansion. The rational addition of axial struts can maintain the longitudinal stability of the device during deployment without making the device too rigid.

[0086] The ends of the shunt may be flared during manufacture of the device. Fig.14 As shown, the shunt 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" construction, so that there are gaps between some peaks. In another implementation, the distal end 740 and the proximal end 739 have the same design, whether it is a closed cell, an open cell or a mixed design. The flaring angle can change from 15 degrees to 40 degrees, or about 20 degrees to 30 degrees, from the proximal end to the distal end relative to the longitudinal axis of the shunt 700. The purpose of the flared shape is to ensure a good fit of the shunt end to the vessel wall even if the device is deployed in a curve. The elastic properties of the nickel-titanium (NiTi) cutting tube device make the device with the flared end press against the outside of the curve when positioned in the curve. The device without the flared end may be lifted from the vessel wall on the inside of the curve. Depending on the position of the device in the curve, either end of the device can be lifted off the wall. If the tip is lifted, it may cause problems with subsequent advancement or retraction of the device through the shunt and increase the risk of device thrombosis.

[0087] The flaring at the proximal end area of ​​shunt can be greater than the flaring at the distal end of shunt.For example, the angle of the flaring at the proximal end can be about 40 degrees, and the angle of the flaring at the distal end can be about 20 degrees, so that the diameter of the stent lumen opening at the proximal end can be about 10mm and the diameter of the stent opening at the distal end can be about 7mm.By contrast, the outer diameter in the central area of ​​the stent can be about 4.25mm.The length of the flaring on the distal end and the proximal end can be about 3mm to 4mm long respectively, and the non-flared uniform OD region can be about 20mm to 23mm long.

[0088] The length of the middle shunt zone 730 can be about 8 mm to 12 mm. For a total length of about 18 mm to 35 mm, preferably about 20 mm to 30 mm, the length of each of the end zones 733, 734 can be about 5 mm to 10 mm. The number of nested struts around the circumference of the stent can be greater than 12, such as about 16, to align with the 16 strut geometry of the anchoring area. The gap between the struts in the middle shunt zone can be about 33 microns to 34 microns.

[0089] Figure 3 Detail of a repeating laser cut pattern of a shunt 700 is shown, illustrating how the porosity of the device is defined. In this view, the V-shaped cells 750 are nested within each other so that the center bends are aligned and the peaks 757 of one cell 750 are spaced from the valleys 753 of an adjacent cell 750 by the distance of the connecting bridge 752. The struts 751 of the cells 750 define V-shaped openings 754 between them. The spacing between the cells 750 provided by the bridge 752 forms additional V-shaped openings 756 arranged in the opposite direction of the cells 750. The openings 754 of the cells 750 and the openings 756 between the cells 750 (when the shunt is viewed in the opposite orientation) represent the open space (AO), and the struts 751 and bridge 752 represent the metal structure (AM) of the shunt. The sum of the open space and the metal structure is equal to the area "A" of the circumscribed rectangle. The porosity (p) can be defined as the ratio of the open space to the total area, p=AO / A. The coverage (c) can be defined as the ratio of metal area to total area, c = AM / A. In this configuration, the porosity is approximately equal to 70% and the material coverage is approximately equal to 30%. Figure 3 The typical spacing between adjacent struts 751 of a cell 750, shown as d in FIG. 7 , can vary depending on whether the cell 750 is located in the middle region 701, intermediate regions 702, 704, or end regions 703, 705 of the diverter 700. In some implementations, the spacing d between strut pairs 751 of a single cell 750 in the middle region 701 can be approximately 0.08 mm. The coverage and porosity described are calculated for the middle region 701 of the diverter, which is located in the middle region 701 of the diverter. Figure 3 The expanded configuration shown has the following dimensions. The gap between the center bends of the strut pairs 751 of the individual units 750 is Figure 3 In the max This is the maximum gap between the strut pairs in the flow direction and can be approximately 0.22 mm in the middle region 701 of the splitter 700. The maximum gap between the strut pairs 751 of the single unit 750 perpendicular to the flow direction is Figure 3 In the max , and can be approximately 0.29 mm in the middle region 701. The area of ​​the V-shaped opening 754 at the central bend of the strut pair of unit 750 (e.g., between the valley 753 and the peak 757) can be determined by the maximum diameter Φ of the circle that fits within the opening 754. max For the unit 750 in the middle region 701, the maximum diameter Φ max It may be approximately 500 microns or less, or between about 100 microns and 500 microns, preferably about 250 microns. The gap d, dX of the unit 750 max dYmax and Φ max The size range of dX may vary depending on whether the unit 750 is in the middle region 701, the intermediate regions 702, 704, or the end regions 703, 705. max ,dY max and Φ max It may be about 500 microns or less, about 100 microns and 500 microns, such as about 250 microns.

[0090] The shunts described herein may include a radiopaque marker container 770 (see Figure 1B ) is incorporated into one or more of the end features and / or positioning features. For example, a first set of one or more containers 770a can be positioned at the proximal and distal ends of the shunt, and a second set of one or more containers 770b can be positioned to identify a length Lc such as at either end of the middle shunt region 701. Containers 770a can be positioned at the most distal end and the most proximal end, while containers 770b can be positioned over the valley of the middle shunt region 701 to identify the densest coverage. Radiopaque material can be pressed into the containers 770 to make the ends and regions of the shunt 700 visible under fluoroscopy. For example, radiopaque markers can be located in containers 770b on either end of the middle region 701, enabling a user to confirm that the location of the middle region 701 with approximately 30% material coverage is properly positioned across the aneurysm neck, and / or perform surgical steps to ensure that this is true. The arrangement of the containers 770 can vary and can be used in a variety of ways. Figure 1B Several are shown as illustrations and are not intended to be limiting, as container 770 may be positioned in any of a variety of locations depending on which portion of the shunt is desired to be visualized. At least one of the proximal end region, the middle region, and the distal end region may include at least one radiopaque marker.

[0091] The flow diverter 700 can be designed to be at least partially retractable some distance during the deployment process. FIG. 8A to FIG. 8C as well as FIG. 11C to FIG. 11D Described in more detail, the shunt 700 can be deployed using a shunt delivery system 800 having an inner core member 820 and an outer restricting sleeve 810. The shunt 700 is mounted on the inner core member 820, and the outer restricting sleeve 810 can be pulled back a specified amount to partially deploy the shunt 700 (see Figure 8C ). The design of shunt 700 allows the user to withdraw restraining sheath 810 proximally a distance to partially deploy a portion of the shunt, and then, if desired, re-advance the sheath distally to reposition distal end 707 of shunt 700.

[0092] The cut pattern of the shunt 700 determines whether the shunt is re-insertable. If the pattern includes features that pop out beyond the inner diameter of the outer restraining sleeve 810, the shunt 700 generally cannot be re-inserted after partial deployment. However, the shunts described herein may incorporate features that ensure that the shunt 700 remains within a specific outer diameter that can be received within the restraining sleeve even after partial deployment (see Figure 1E track 775).

[0093] Figures 1A to 1C The flow divider has bridges 752 that connect the valleys 753 of a first cell 750 to the peaks 757 of cells 750 in the same row 765 of an adjacent ring 760. However, these peak-to-valley connections can skip rings 760 so that the peak-to-valley bridges alternate. The bridges 752 connecting the struts 751 near the edges of the cells 750 also alternate from ring to ring. Figures 1D to 1FIn the implementation of the flow divider in, some bridges 752 of the struts 751 near the edges of the connecting cells do not alternate from ring to ring. Instead, these bridges 752 form a continuous track 775 that extends the axial length of the flow divider 700. The track 775 can form a line that passes through at least 3 cells, at least 4 cells, at least 5 cells, at least 6 cells, at least 7 cells, or at least 8 cells connecting radially adjacent hinges (or center bends). The line can connect 3 to 8 cells or about 4 to 6 cells. The connected cells can be found in the middle zone, intermediate zone, or terminal zone. The line connecting radially adjacent hinges can be in the proximal zone and distal zone, and passes through fewer cells than the line connecting radially adjacent hinges in the middle zone. Tracks 775 may be found in one or two zones 702, 703 near the distal end 707 of the shunt 700, but not in corresponding zones 704, 705 near the proximal end 709 of the shunt 700, such that the shunt 700 is asymmetric between its distal end 707 and proximal end 709. The presence of tracks 775 within zones 702 and / or 703 near the distal end 707 of the shunt 700 is configured to allow re-insertion even after the restraining sleeve 810 is withdrawn to partially deploy the zones 702, 703 and expose at least a portion of the middle zone 701. In yet another implementation, these additional axial tracks 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 to make the shunt 700 re-insertable over nearly the entire deployed length of the shunt 700. Alternatively, if greater flexibility in nesting capability is desired, the axial track 775 can extend over one end region 703 of the flow diverter, rather than over two or more regions of the flow diverter 700. The axial track 775 is shown extending between the peak to valley portions of the cell 750. Other axial features can be added at other locations (one or more) of the cell 750, such as between struts. The axial peak to valley track 775 or other axial features added between struts between the annular segments 760 can also limit feature intrusion into the lumen or aneurysm space when the flow diverter 700 is positioned in a curve (a phenomenon referred to as "fish scaling" when referring to open-cell stent designs).

[0094] Figures 1A to 1F The implementation shown in has a cutting pattern that provides a desired material coverage when expanded in a vessel, which coverage can (but need not) vary along the axial length of the shunt. FIG. 4A to FIG. 4CA shunt 700 is shown constructed from two laser cut non-braided tubular members or tubes 706, 708 that together provide a desired material coverage when the shunt is expanded in a vessel and that, depending on the overlap, can provide progressive material coverage along the length of the shunt 700. When expanded, each of the two tubes 706, 708 can each have a density of 15%, but when assembled together, have a total material density of 30%. The two tubes 706 and 708 can be assembled overlapping but staggered to form an overlap region having a first density (e.g., 30% material coverage and 70% porosity), and each end of the staggered tubes 706, 708 has a second, lower density (e.g., 15% material coverage and 85% porosity). The two tubes 706, 708 can be locked together by a locking feature built into the laser cut pattern. For example, as Figure 4A As shown in FIG. 1 , one tube 706 may have one or more holes or elongated slots 710 laser cut on either or both ends of the tube 706, and a second tube 708 may have one or more corresponding tabs 712 formed to protrude into the slots 710 and then lie flat. The two tubes 706, 708 are assembled so that the tabs 712 are inserted into the slots 710 and then the tubes 706, 708 are slid relative to each other to lock the two tubes 706, 708 together. In a variation, as shown in FIG. Figure 4B As shown, the slot 710 can have an "L" shape so that the two tubes 706, 708 can be rotated relative to each other to lock the two tubes 706, 708 together. Alternatively, the tab 712 can be pushed through the slot 710 and bent to lock in place, such as Figure 4C The tabs 712 may be on the inner tube 708 and the slots 710 on the outer tube 706, or vice versa.

[0095] FIG. 5A to FIG. 5B Another locking mechanism of a flow divider 700 constructed from two laser cut tubes 706, 708 is illustrated. Both tubes 706, 708 may be laser cut to include holes or elongated slots 710 on either or both ends in corresponding locations. The two tubes 706, 708 are assembled one inside the other so that their corresponding holes 710a, 710b are aligned. A disk 716 made of a ductile material may be pressed into the holes 710a, 710b to lock the tubes 706, 708 together. The disk 716 may be slightly tapered (i.e., as Figure 5A710a, 710b and is securely held in place. The disc 716 may be a radiopaque, ductile material such as gold, a gold alloy, or tungsten to serve as both a radiopaque marker on the implant and a locking mechanism.

[0096] Fig. 6A Another implementation of a flow splitter 700 constructed from two laser cut tubes 706, 708 is illustrated. One tube 706 is designed to provide full wall fit and anchoring, such as by providing structural integrity to the flow splitter 700 through wall thickness and / or strut width. The other laser cut tube 708 is designed to provide 30% material coverage and has a very fine strut pattern and thin wall thickness. Figure 6B As shown, the thinner cutting tube 708 can also be a very thin wire braided tube, or a porous material, such as an expanded PTFE tube. The thinner strut pattern tube 708 can also be shorter than the larger strut structure tube 706. Alternatively, as shown in FIG. Figure 6B As shown in FIG. 1 , the two tubes 706 , 708 may be the same length and the tubes 706 , 708 may substantially overlap one another.

[0097] These multi-layer shunt implants 700 utilize the structural stent layers of tube 706 to provide precise placement and anchoring, and utilize the finer stent layers of tube 708 to provide greater material coverage to divert blood flow into the excluded aneurysm. The larger diameter access systems described herein enable delivery of these multi-layer devices, which is not possible with current microcatheter delivery methods having smaller inner diameters (e.g., 0.027"), which, as described above, cannot accommodate a laser cut shunt alone, and certainly not a flower shunt and a restricting sleeve.

[0098] The flow divider 700 may also be made of different materials and structures along its length. Figure 7 As shown in FIG. 1 , the shunt 700 is formed by two laser cut bands 718, 722 located on both ends of the device. A thinner structure, such as a braided wire tube 720, can be positioned between and connected to the two laser cut bands 718, 722 to form a multi-segment implant. The braided wire tube 720 can be interwoven with the laser cut bands 718, 722 to couple to the bands. This composite or hybrid design provides the shunt 700 with two end anchors with higher material coverage across the aneurysm.

[0099] The shunt implants described herein may be self-expanding tubes or tube components cut into a desired pattern. Any cut tube components in the shunts described herein may be self-expanding material or made from one or more Nitinol laser cut tubes. The tube may be Nitinol or another elastic material that may have the desired mechanical properties of a self-expanding device.

[0100] The tube or cut tube component can be laser cut, machined, photoetched by photolithography or other chemical etching, etc. to achieve the desired cutting pattern. As an alternative to cutting the design from a cylindrical tube, the design can be cut or assembled into a planar configuration as a planar pattern and compressed or otherwise wrapped or rolled up into a spiral or cylindrical configuration for delivery, and expanded in situ into a partial cylindrical configuration, a cylindrical configuration, or a partially or completely overlapping roll configuration. In the latter implementation, features for locking or ratcheting the diverter in the expanded shape can be included. The cut tube can also be manufactured by vapor depositing the material in a tubular or flat pattern, and then rolling up the latter.

[0101] The cut tube may undergo a finishing process such as electropolishing and heat setting to achieve desired mechanical and dimensional properties. In some implementations, the shunt may be heat formed to flare one or both of the ends 707, 709 to assist in anchoring the shunt to the vessel wall during deployment.

[0102] As described herein, other materials and manufacturing methods may also be utilized to manufacture shunts. Alternatively, any of the above-described shunt implants may be a balloon-mounted laser-cut stent, made of one or more laser-cut stainless steels, cobalt-chromium alloys, or other materials known for balloon-expandable stents. In addition to the typical composition of superelastic nickel-titanium, the shunt may be made of a tubing material comprising a radiopaque material. For example, the radiopaque material may comprise platinum, tantalum, tungsten, or gold. The radiopaque material may be uniformly incorporated into the material in a favorable proportion, or the material may be constructed as a laminate that includes one or more layers of radiopaque material in addition to one or more layers of nickel-titanium, or may be coated onto the surface of the nickel-titanium.

[0103] The systems described herein are used with larger caliber access systems, and therefore, if desired, the shunt can be a braided wire shunt in which the braiding parameters of the braided wire shunt are modified to improve performance. For example, as required by current shunts, the wire size and / or number of wires can be increased without the design limitations of being deliverable via a 0.021" or 0.027" ID microcatheter delivery system. An example of a current braided shunt is a tubing embolization system with 48 wires x 30 microns (0.0013"). Increasing the wire size would make it incompatible with a microcatheter with an inner diameter of 0.027". Shunts with a larger number of braided wires have smaller wire sizes, for example the Surpass Evolve has a 64-wire braid with 0.0011" wires. Likewise, increasing the wire size would make it incompatible with a microcatheter with an inner diameter of .027". In an implementation, the shunt 700 is a braided wire shunt constructed of 48 or up to 96 or more wires with a wire strand diameter between 35 microns and 55 microns. Such larger gauge and / or greater number of wire strand braided shunts have greater radial force and faster elastic opening speed, making them easier to deploy and reducing current problems with braided shunts, such as flattening and ribboning during deployment.

[0104] The shunts described herein may have specialized anti-thrombotic surface modifications or coatings, for example, heparin coatings, hydrophilic polymer coatings (such as phosphorylcholine and phenoxy hydrophilic polymers), albumin, fibrin, and the like.

[0105] Shunt delivery system

[0106] Shunts are conventionally mounted on an inner delivery core wire and delivered through a microcatheter with an inner diameter of 0.027" (0.7 mm). In order to be delivered through such a small size delivery system while still providing the desired wall coverage (approximately 30%) when expanded up to 5.0 mm diameter in the vessel, shunts conventionally have a braided wire construction.

[0107] The delivery of conventional braided shunts occurs conventionally through several surgical steps. First, a microcatheter is inserted into the vascular system and advanced over the guidewire to a position across the target aneurysm site. Due to the imprecision of delivering braided shunts, the microcatheter end is usually placed far distal to the final target implant site. Once the microcatheter is in position relative to the target aneurysm, the guidewire is removed. The braided shunt is then inserted into the proximal end of the microcatheter using a guide tube. The shunt is pre-installed on the delivery core wire by keeping the shunt restricted in a contracted configuration and longitudinally fixed on the delivery core wire. For example, the core wire can have a PTFE sleeve that covers and constrains the braided shunt at either end. The core wire typically has a distal flexible end that extends until 15mm beyond the distal end of the shunt. This means that in order to implant the shunt in the correct position, the distal end needs to be positioned at least 15mm beyond the treatment site, and if the microcatheter is positioned distally, it may be more, which is another source of potential complications. The core wire is used to push the shunt to the end of the microcatheter. The microcatheter is then retracted to expose the braid, which begins to pop open due to its material properties and construction. Due to the nature of the braided construction, the distal end does not reach its full opening diameter until the braid is exposed for several millimeters. The user must often push the microcatheter while pulling the core to "push" the braid to its maximum opening so that the shunt fits completely against the vessel wall, which is highly desirable for achieving the expected clinical effect. This push-pull technique is another potential cause of clinical complications of conventional braided shunts, and increases the inaccuracy of surgical time and implantation location. The braid shortens significantly when expanded due to its nature, making accurate implantation more difficult. Typically, the shunt is delivered to the distal side of the desired site, and then partially deployed and "dragged back" across the target site to the appropriate position. There is a risk of vascular damage and vascular perforation in both the distal positioning and "drag-back" steps of the microcatheter, both of which lead to serious clinical sequelae.

[0108] In many shunt delivery systems, the delivery core wire has features that constrain the ends of the braided wire. The microcatheter after the shunt is expanded is fully accessible to the implant and must be re-advanced through the braid to cover the delivery core wire features so that the delivery core wire is not obstructed by the just deployed shunt. Each of these steps potentially disturbs the shunt, increases procedure time, and is a potential cause of clinical complications due to additional catheter manipulation.

[0109] Compared to conventional braided shunts, the shunts described herein can be delivered by a shunt delivery system that is larger in diameter and configured for use with larger caliber access systems. The delivery system described herein can be used with any of the previously described shunts, including laser cut, braided or woven shunts, or a combination thereof.

[0110] FIG. 8A to FIG. 8C A shunt delivery system 800 is illustrated having an outer limiting sleeve 810 and an inner core member 820 having an elongated shaft 823. The inner core member 820 can have an inner lumen (not shown) sized to accommodate a guidewire. The lumen can be a single central lumen that allows the shunt 700 and shunt delivery system 800 to be delivered over a guidewire. The shaft 823 of the inner core member 820 has a reduced diameter recessed section 825 sized to accommodate the shunt 700 near the distal end region. Figure 8B 825 of the inner core member 820 and is retained in this position by the outer restraining sleeve 810. The shunt 700 is retained by the inner core member 820 within the recessed section 825 and is deployed by expansion when the restraining sleeve 810 is withdrawn proximally. The inner core member 820 may include a gripping feature 829 at the proximal end of the recessed section 825 that is configured to prevent the shunt 700 from being dragged back onto the shaft 823 of the inner core member 820 when the restraining sleeve 810 is withdrawn during shunt deployment. The gripping feature 829 may be a high friction component, such as a section of thin-walled silicone or other elastic tubing.

[0111] The material of the shaft 823 of the inner core member 820 is selected to maintain axial integrity during deployment of the diverter 700. For example, the shaft 823 and the recessed section 825 can be constructed of Pebax, such as Pebax 72D. The shaft 823 and / or the recessed section 825 can be braided, coiled, or otherwise reinforced to provide axial stiffness.

[0112] The length of the outer restraining sleeve 810 is shorter than the inner core member 820 by an amount that allows the flow diverter 700 to be fully deployed when the restraining sleeve 810 is pulled back relative to the inner core member 820 (see Figure 8C ). The restraining sleeve 810 is configured so that it can be easily pulled back without dragging the shunt 700 along. For example, the restraining sleeve 810 can be constructed of multiple layers including a low friction liner such as PTFE or FEP. The restraining sleeve 810 can be braid or coil reinforced so as not to stretch during withdrawal. The restraining sleeve 810 can also have an outer hydrophilic coating on the distal portion to improve delivery through large-bore catheters, which will be described in more detail below.

[0113] Reference again Fig. 8A, the inner core member 820 may include a distal end region 827 located distal to the recessed region 825. The distal end region 827 of the inner core member 820 is tapered and has flexibility, shape, tapered length and tapered angle, and the distal end region 827 is configured to deliver the delivery system 800 to the blood vessels in the brain without or with a guidewire. The construction, materials and configuration may be similar to the conical end 346 of the catheter advancement element 300, which will be described below with respect to the access system 100 and described in U.S. Patent No. 11,065,019, which is incorporated herein by reference in its entirety. For example, the distal end region 827 may have two radiopaque markers 844a, 844b, which are configured to depict the conical segment. The first radiopaque marker 844a can identify the distal-most end of the inner core member 820 and the second radiopaque marker 844b can identify the maximum outer diameter region of the taper for optimal delivery purposes relative to the outer restraining sleeve 810. The outer diameter of the inner core member 820 just proximal to the taper is sized to fit smoothly against the inner diameter of the restraining sleeve 810 to provide a smooth leading edge for the shunt delivery system 800 with or without guidewire advancement in the vasculature.

[0114] The shunt 700 and shunt delivery system 800 are sized to be deliverable through larger caliber access systems. As discussed above, the shunt 700 can be a cut tube design having cells 750 arranged in a ring 760 connected peak to valley. When expanded, the shunt 700 has dense material coverage (e.g., 30% coverage or 70% porosity) due to the tightly nested arrangement of the cells 750. The shunt 700 can achieve this dense material coverage by utilizing the constraints of larger caliber access systems. For example, for a distal access system 100 having an access catheter 200 with an inner diameter (ID) of 0.088", the outer limiting sleeve 810 can have an outer diameter (OD) of approximately 0.082", leaving an annular gap of 0.003" (ID / OD difference of 0.006") for optimal advancement of the shunt delivery system 800 through the access catheter 200. In this example, the ID of the outer restraining sleeve 810 is approximately 0.070". The collapsed diverter 700 can have an outer diameter of approximately 0.064" to easily slide through the outer restraining sleeve 810. The inner core member 820 can have an OD of approximately 0.064", with a recessed section 825 of smaller ID depending on the wall thickness of the diverter 700. If the wall thickness of the cut tube diverter 700 is approximately 0.005", the outer diameter of the recessed section 825 is approximately 0.054".

[0115] Larger access systems allow for alternative delivery methods. For example, the shunt 700 described herein can be pre-installed across a delivery system 800 with a limiting sleeve 810 and delivered to the site by a larger delivery system (e.g., 0.087" to 0.126" ID), rather than first placing a microcatheter across the aneurysm, removing the guidewire, and then pushing the shunt into the site as in a conventional shunt delivery system. The guidewire, shunt 700, and inner core member 820 can all be pre-installed in one system, rather than exchanging the shunt and inner core member with a guidewire as in a conventional system.

[0116] In some implementations, the access catheter 200 acts as the limiting sleeve of the shunt delivery system 800, replacing a separate limiting sleeve 810. The shunt 700 can be installed across the inner core member 820, and the same way as the current shunt can be introduced into the microcatheter previously positioned across the target site, via a separate introducer component, the access system 100 is introduced and pushed to the target aneurysm treatment site via the advancement of the inner core member 820. In this example, the access catheter 200 can be positioned across the target site in advance. Once the shunt 700 is positioned at its target site, when the access catheter 200 is pulled back to deploy the shunt 700, the inner core member 820 can be maintained in place. In this example, there is a catheter "layer" (that is, limiting sleeve 810) is eliminated. This allows the shunts of the same size to have a larger internal diameter. A shunt with an outer diameter of 0.064" can be delivered using an access catheter with an inner diameter of 0.070" and an outer diameter of 0.082" (compared to the inner diameter of 0.088" and outer diameter of 0.100" in the previous example).

[0117] Access System

[0118] The shunts and shunt delivery systems described above can be delivered using an access system and / or access catheter having an appropriately large bore inner diameter and capable of reaching the target aneurysm treatment site. Current access devices, ie, guide catheters and / or guide sheaths, have limitations when used to access neurovascular anatomy.

[0119] A guide catheter or guide sheath is used to guide an interventional device from an arterial access site (usually a femoral artery) to a target anatomical structure. The length of the guide is determined by the distance between the access site and the desired site at the distal end of the guide. An interventional device (such as a guidewire, a microcatheter, and an intermediate catheter for a sub-selective guide) is inserted and advanced to the target site through the guide. Typically, the device is used in a coaxial manner, i.e., the guidewire is inside the microcatheter inside the intermediate catheter, and is advanced to the target site in a stepwise manner as an assembly, wherein the least traumatic element inside is first advanced distally and provides support for the advancement of the outer element. The length of each element of the coaxial assembly takes into account the length of the guide, the length of the proximal connector on the catheter, and the length required to extend from the distal end.

[0120] Typical triaxial systems such as systems for delivering shunts, stents, stent retrievers, and other interventional devices require a series of overlapping catheters, each with its own rotary hemostatic valve (RHV) at the proximal end. For example, a guidewire can be inserted via a Penumbra VELOCITY microcatheter with a first proximal RHV, which can be inserted via a Penumbra ACE68 with a second proximal RHV, which can be inserted via a Penumbra NEURONMAX 088 access catheter with a third proximal RHV positioned in the high carotid artery via a femoral introducer. Maintaining the coaxial relationship between these catheters is technically challenging. The three RHVs must be constantly adjusted with two hands or more commonly four hands (i.e., two operators). In addition, the workspace of a typical triaxial system for intracranial device delivery and brain device delivery may require a 3-foot to 5-foot workspace at the base of the operating table. It takes time to access the treatment site using a triaxial system.

[0121] There are also difficulties in introducing larger caliber access catheters and sheaths into intracranial and cerebral vessels in a fast and non-invasive manner. Both the length and diameter of current systems limit the delivery system of intravascular stent devices (such as stents or shunts), which in turn limits the safety, speed and accuracy of delivering such devices. Systems and methods that allow rapid access to devices with larger lumen sizes and / or shorter lengths of distal intracranial and cerebral vessels are needed.

[0122] Access system and method described herein make it possible to locate large interventional devices (such as shunt delivery system) safely and quickly to the aneurysm site in intracranial artery or cerebral artery. In addition, the extreme flexibility and deliverability of the distal access catheter system described herein allow catheter to take the shape of tortuous anatomical structure, rather than applying the straightening force forming new anatomical structure. The distal access catheter system described herein can pass through tortuous rings, while keeping the natural curve of anatomical structure wherein, thereby reducing the risk of blood vessel straightening. The distal access catheter system described herein can form a safe pipeline passing through neurovascular system thus, keeping the natural tortuosity of anatomical structure for other catheters to pass (for example, interventional device delivery catheter). The catheter passing through pipeline does not need to have the same degree of flexibility and deliverability, so that if they are directly delivered to identical anatomical structure rather than by pipeline, the straightening, kink or folding of the anterior circulation will be caused.

[0123] Provided herein is an access system comprising a catheter advancement element, which has a tapered distal end region, which has flexibility, shape and tapered length configured to be delivered to the blood vessel in the brain atraumatically. Conventional catheter systems can not realize this point, because they may have inappropriate flexibility, are formed by inappropriate materials, or have inappropriate shapes and / or tapered lengths, causing conventional catheter systems to be mistakenly guided or hung up, or if applying greater force, penetrate blood vessels. Different from these conventional catheter systems, catheter system described herein comprises a catheter advancement element, which can safely navigate neurovascular anatomical structures and find lumen, so that corresponding large-caliber catheters (i.e. shunt delivery systems) can be delivered to distal sites. Catheter system described herein helps to locate the occlusion in the blood vessel in the novel manner of the method provided herein. These features and other features will be described in detail herein.

[0124] FIG. 9A to FIG. 9B Illustrated is an implementation of a distal tip access system 100 that includes a device for accessing and treating an intracranial or cerebral aneurysm, such as by deploying a flow shunt. Fig.9A is an exploded view of an implementation of the access catheter system and Fig. 9B yes Fig.9A Assembly view of the catheter system. Fig. 10A It is taken along circle CC Fig.9A Detailed view of catheter advancement element 300. Fig. 10BDetailed view of a catheter advancement element having a guidewire 500 in lumen 368 such that the distal end of the guidewire 500 extends distally of the distal opening 326 of lumen 368. The distal access system 100 is capable of providing rapid and simple access to distal target anatomical structures, particularly the tortuous anatomical structures of the intracranial vasculature and the 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 one operator through a single manipulation point requiring minimal hand movement. As will be described in more detail below, all wire and catheter manipulations can occur at or adjacent to a single rotary hemostatic valve (RHV), or at or adjacent to multiple RHVs co-located in the same device.

[0125] The system 100 may 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 excellent deliverability. The catheter 200 may, but need not, be a distal access catheter having a distal tubular member coupled to a proximal control element of a smaller outer diameter. The distal tubular member coaxial with the lumen of the guide sheath 400 provides a stepwise increase in the inner diameter of the conduit. The catheter need not include a proximal control element and may instead be a conventional full-length catheter of uniform diameter.

[0126] The catheter 200 can be delivered using a catheter pusher element 300 inserted 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 a tortuous anatomical structure and avoid applying a straightening force that forms a new anatomical structure. The distal access catheter 200 is able to do this even when the catheter pusher element 300 extends through its lumen. Therefore, the flexibility and deliverability of the catheter pusher element 300 is comparable to or better than the flexibility and deliverability of the distal lumen portion 222 of the distal access catheter 200, because both are configured to reach the middle cerebral artery (MCA) circulation without straightening the curve of the anatomical configuration along the route.

[0127] Still reference FIG. 9A to FIG. 9B, the distal end access system 100 can include an access guide sheath 400 having a body 402, with a working lumen extending through the body 402 from a proximal hemostasis valve 434 coupled to a proximal end region 403 of the body 402 to a distal opening 408 of the distal end region. The working lumen is configured to receive a catheter 200 therethrough so that the distal end of the catheter 200 can extend beyond the distal end of the sheath 400 through the distal opening 408. The guide sheath 400 can be used to deliver the catheters described herein and any of a variety of working devices known in the art. For example, the working device can be configured to provide thrombosis treatment and can include a large-bore catheter for delivering a shunt.

[0128] The sheath body 402 can extend from a proximal end portion at the proximal end region 403 to a distal end opening 408 of the body 402 by a forked or rotating hemostatic valve (RHV) 434. The proximal RHV 434 can include one or more lumens 412 molded into the connector body to connect to the working lumen of the body 402 of the guide sheath 400. The working lumen can receive any of a variety of working devices for delivery to the target anatomical structure of the catheter 200. The RHV 434 can be constructed of a thick-walled polymer tube or a reinforced polymer tube. The RHV 434 allows the device to be introduced into the vascular system through the guide sheath 400 while preventing or minimizing blood loss and preventing air from being introduced into the guide sheath 400. The RHV 434 can be integral with the guide sheath 400, or the guide sheath 400 can terminate on the proximal end in a female Luer adapter to which a separate hemostatic valve component (such as a passive sealing valve, Tuohy-Borst valve, or RHV) can be attached. The RHV 434 can have an adjustable opening that is large enough to allow removal of the device with an adhered blood clot on the distal end opening 408 without causing the blood clot to shift at the RHV 434 during removal. Alternatively, the RHV 434 can be removable (such as when the device is removed from the sheath 400) to prevent the blood clot from shifting at the RHV 434. The RHV 434 can be a double RHV or a multi-head RHV.

[0129] Contrast agent can be injected into the blood vessel through the guide sheath 400 to visualize the occlusion site through angiography. For example, the guide sheath 400 can be positioned so that at least a portion is positioned in the carotid artery. Once positioned in this position, a 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. Before inserting the device, a baseline angiography can be obtained, such as in an anterior / posterior (AP) view and / or a side view, to evaluate the occlusion site by visualizing the injection of contrast agent through the sheath 400 with fluoroscopic visualization. As the catheter system advances, fluoroscopic visualization can continue, and subsequent angiography can be captured periodically to evaluate reperfusion. The baseline angiography image can be superimposed, such as with digital subtraction angiography, so that the vascular system and / or occlusion site are visible when the catheter system advances.

[0130] Once the catheter system 150 is advanced to the proper position (positioning will be described in more detail below), the catheter advancement element 300 can be withdrawn from the system and removed. In some implementations, the catheter 200 can be used as a support catheter to deliver a stent or shunt to a treatment site (e.g., within a carotid or cerebral artery), as will be described elsewhere herein.

[0131] In an implementation, the guide sheath 400 includes one or more radiopaque markers 411. The radiopaque marker 411 can be disposed near the distal end opening 408. For example, a pair of radiopaque bands can be provided. The radiopaque marker 411 or any system component marker can be swaged, painted, embedded, or otherwise disposed in or on the body. In some implementations, the radiopaque marker includes a barium polymer, a tungsten polymer blend, a tungsten-filled, or a platinum-filled marker that maintains the flexibility of the device and improves the transition along the length of the component and its kink resistance. In some implementations, the radiopaque marker is a tungsten-loaded PEBAX or polyurethane that is heat welded to the component.

[0132] The guide sheath marker 411 is shown as a ring around the circumference of one or more regions of the main body 402. However, the marker 411 can have other shapes or form a variety of patterns that provide the operator with orientations about the position of the distal opening 408 in the blood vessel. Therefore, the operator can visualize the position of the distal opening 408 under fluoroscopy to confirm that the distal opening 408 points to the target anatomical structure to which the catheter 200 will be delivered. For example, (one or more) non-transmissive wire markers 411 allow the operator to rotate the main body 402 of the guide sheath 400 at the anatomical access point (e.g., the patient's groin) so that the distal opening provides access to the ICA through (one or more) subsequent working devices (e.g., catheters and wires that are advanced to the ICA). In some implementations, (one or more) non-transmissive markers 411 are included in platinum, gold, tantalum, tungsten or any other material visible under an x-ray fluoroscope. Any of the various components of the system described herein can be combined with non-transmissive markers.

[0133] Still reference FIG. 9A to FIG. 9B , catheter 200 can include a relatively flexible distal lumen portion 222, which is connected to a harder, anti-kink proximal extension or proximal control element 230. As used herein, the term "control element" can refer to a proximal region that is configured for a user to cause a push movement in a distal direction and a pull movement in a proximal direction. The control element described herein can also be referred to as a spine, tether, push wire, push tube or other element with any of a variety of configurations. The proximal control element 230 can be a hollow or tubular element. The proximal control element 230 can also be solid and have no inner lumen, such as a solid rod, ribbon or other solid wire type element. In general, the proximal control element described herein is configured to move its corresponding component (the proximal control element can be attached to the component or integrated with it) through the lumen in a bidirectional manner.

[0134] A single inner lumen 223 extends through the lumen portion 222 between the proximal and distal ends of the lumen portion 222 (the lumen 223 is located at Fig. 9B4. In some implementations, the proximal opening 242 of the access lumen 223 can be located near where the proximal control element 230 is coupled to the distal lumen portion 222. In other implementations, the proximal opening 242 of the access lumen 223 is at a proximal end region of the catheter 200. The distal opening 231 of the lumen 223 can be located near or at the distal-most end 215 of the lumen portion 222. The inner lumen 223 of the catheter 200 can have a first inner diameter, and the working lumen of the 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 can be configured to be fluidly connected and abutting the working lumen of the sheath 400, such that fluid inflow and / or outflow of fluid into and out of the system 100 is possible, such as by applying suction from a vacuum source coupled to the system 100 at the proximal end. As the catheter 200 is advanced and withdrawn, the combination of the sheath 400 and the catheter 200 may be in continuous communication with the blood flow at the proximal end.

[0135] The distal lumen portion 222 of the catheter 200 can have one or more radiopaque markers 224. A first radiopaque marker 224a can be located near the distal-most end 215 to assist in navigation under fluoroscopy and to properly position the distal-most end 215. Additionally, the proximal region of the catheter 200 can have one or more proximal radiopaque markers 224b so that the overlap region 348 can be visualized 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 can also have one or more radiopaque markers that provide visibility, for example, near the proximal opening 242 in the single lumen 223 of the catheter 200, as will be described in more detail below. In one implementation, the two radiopaque markers (the most distal end 215 access marker 224a and the more proximal marker 224b) are different to minimize confusion of the fluoroscopic image, for example, the catheter proximal marker 224b can be a single band, while the marker 411 on the guide sheath 400 can be a double band, and any markers on the working device delivered by the distal access system can have another type of band or marker. The radiopaque markers 224 of the distal lumen portion 222, especially those navigating extremely tortuous anatomical structures near the distal end region, can be relatively flexible so that they do not affect the overall flexibility of the distal lumen portion 222 near the distal end region. The radiopaque markers 224 can be tungsten-loaded markers or platinum-loaded markers, which are relatively flexible compared to other types of radiopaque markers used in devices where flexibility is not of paramount importance. In some implementations, the radiopaque markers can be tungsten-loaded PEBAX bands having a Shore A35D hardness.

[0136] The proximal control element 230 may include one or more markings 232 to indicate overlap between the distal lumen portion 222 of the catheter 200 and the sheath body 402, as well as 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 marking may be an RHV proximity marking positioned such that when the marking is aligned with the sheath proximal hemostasis valve 434 during insertion of the catheter 200 through the introducer sheath 400, the catheter 200 is positioned in a distal-most position with a minimum overlap length required to form a seal between the catheter 200 and the working lumen. At least a second marking 232 may be a fluorescent protection marking that may be positioned on the control element 230 and located at the distal-most end 215 of the distal lumen portion 222. In some implementations, the marking 232 may be positioned approximately 100 cm away from the distal-most end 215 of the distal lumen portion 222. The markers 232 can be positioned on the catheter so that during use, one or more of the markers are visible to an operator outside the patient (and outside the guide sheath 400). During use, one or more of the markers can also be visible to an operator inside the patient (and inside or beyond the distal end of the guide sheath 400) so that they are visible under fluoroscopy.

[0137] FIG. 9A to FIG. 9B The catheter 200 shown in FIG. 2 is less than full length and includes a rapid exchange opening 242 that enters the distal lumen portion 222. The catheter 200 may also be a full length catheter having a lumen terminating between a distal opening and a proximal opening that is configured to remain external to the sheath hub and external to the patient.

[0138] Still reference FIG. 9A to FIG. 9B as well as Fig. 10A, the catheter propulsion element 300 can include non-expandable flexible elongated body 360 and proximal portion 366. The catheter propulsion element 300 and catheter 200 described herein can be configured for rapid exchange or by silk method. For example, the flexible elongated body 360 can be a tubular portion extending over the entire length of the catheter propulsion element 300 and can have a proximal opening from the lumen 368 of the flexible elongated body 360, which is configured to extend to the patient's body exterior during use. Alternatively, the tubular portion can have a proximal opening, which is positioned so that the proximal opening remains in the patient's body interior during use. The proximal portion 366 can be a proximal element that is coupled to the distal tubular portion 360 and extends proximally therefrom. The proximal opening of the tubular portion 360 can be positioned near the place where the proximal element 366 is coupled to the tubular portion 360. Alternatively, the proximal portion 366 can be an extension of the tubular portion 360 having a length extending to a proximal opening near the proximal terminal end of the catheter advancement element 300 (i.e., outside the patient's body). A Luer connector 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 coupled to the Luer connector 364 to draw a vacuum and / or inject a fluid through the lumen 368. A syringe coupled to the Luer connector 364 can also be used to close the lumen of the catheter advancement element 300 to maximize the piston effect described elsewhere herein.

[0139] The configuration of the proximal portion 366 can be varied. In some implementations, the proximal portion 366 is only a proximal extension of the flexible elongated body 360 that does not change significantly in structure but changes in flexibility. For example, the proximal portion 366 transitions from the very flexible distal region of the catheter propulsion element 300 toward the less flexible proximal region of the catheter propulsion element 300. In some implementations, the proximal portion 366 can provide a relatively hard proximal end suitable for manipulating (e.g., advancing and withdrawing) the more distal region of the catheter propulsion element 300 relative to the anatomical structure and / or the outer catheter 200. The proximal portion 366 can be formed by a polymer that is less flexible than the flexible elongated body. The proximal portion 366 can be a fully polymerized without reinforcement, or the proximal portion 366 can be a reinforced polymer portion. The configuration of the proximal portion 366 can be used with full-length catheters or with catheters with only short distal tubular portions according to whether the catheter propulsion element 300 is used together with full-length catheters or used together with catheters with only short distal tubular portions. The catheter propulsion element 300 used with a full-length catheter does not need to rely on proximal reinforcement to propel the catheter system through the anatomical structure and can instead rely on the proximal stiffness of the outer catheter. The catheter propulsion element 300 used with a partial-tube outer catheter can benefit from a stiffer reinforcement in its proximal end region for propulsion of the system.

[0140] In some implementations, the proximal portion 366 is a metal reinforcement segment. The metal reinforcement segment can be positioned at a distance away from the distal end of the slender body. For example, the metal reinforcement segment can be about 50cm away from the distal end. The metal reinforcement segment can have an inner diameter of about 0.021 "and an outer diameter of about 0.027". The metal reinforcement segment can be a ridge. The metal reinforcement segment can be a hypotube. In other implementations, the proximal portion 366 is a hypotube. The hypotube can be exposed or can be coated with a polymer. In a further implementation, the proximal portion 366 can be a tubular polymer portion reinforced by a spiral ribbon or a braid. The proximal portion 366 can have the same outer diameter as the flexible elongated body or can have an outer diameter smaller than the flexible elongated body.

[0141] The proximal portion 366 does not need to include a lumen. For example, the proximal portion 366 can be a solid rod, ribbon or silk thread that does not extend through the lumen of the tubular elongated body 360 that is connected to it. When the proximal portion 366 is described as having a lumen in this article, it should be understood that the proximal portion 366 can also be solid and do not have a lumen. The proximal portion 366 is generally less flexible than the elongated body 360 and can be even harder towards the most proximal end of the proximal portion 366. Therefore, the catheter propulsion element 300 can have an extremely soft and flexible distal end region 346, which transitions to the hard proximal portion 366 that is very suitable for pushing and / or twisting the distal elongated body 360.

[0142] The elongated body 360 can be received within and extend through the inner lumen 223 of the distal lumen portion 222 of the catheter 200 (see Figure 2B). The elongated body 360 or tubular portion may have an outer diameter. The outer diameter of the tubular portion may have at least one abutment point. The at least one abutment point provides a tight fit between the elongated body 360 and the distal lumen portion 222, which minimizes the distal lip or edge at the distal end of the catheter 200, but still allows movement relative to each other to allow a user to achieve a desired extension or withdrawal of the catheter advancement element 300 relative to the catheter 200 or the catheter 200 relative to the catheter advancement element 300. The abutment point allows movement between the catheters when a relatively small load is applied to avoid any negative impact on usability in the patient. At the abutment point, the difference between the inner diameter of the catheter 200 and the outer diameter of the tubular portion can be no greater than about 0.015" (0.381 mm), or can be no greater than about 0.010" (0.254 mm), for example, from about 0.003" (0.0762 mm) up to about 0.012" (0.3048 mm), preferably about 0.005" (0.127 mm) to about 0.010" (0.254 mm), and more preferably about 0.007" (0.1778 mm) to about 0.009" (0.2286 mm).

[0143] As will be described in more detail below, the catheter advancement element 300 may also include a distal end region 346 located distal to at least one abutment point of the tubular portion. The distal end region 346 may have a length and taper along at least a portion of the length. The distal end region 346 of the catheter advancement element 300 may extend beyond the distal end of the catheter 200, such as Fig. 9B 360. The proximal portion 366 or proximal extension of the catheter advancement element 300 is coupled to the proximal end region of the elongated body 360 and extends proximally therefrom. The proximal portion 366 can be less flexible than the elongated body 360 and is configured for bidirectional movement of the elongated body 360 of the catheter advancement element 300 within the lumen portion 222 of the catheter 200 and for movement of the catheter system 100 as a whole. The elongated body 360 can be inserted through the inner lumen 223 of the lumen portion 222 in a coaxial manner. The outer diameter of at least one region of the elongated body 360 can be sized to substantially fill at least a portion of the inner lumen 223 of the lumen portion 222.

[0144] The overall length of the catheter advancement element 300 (e.g., between the proximal end region to the distal-most tip) can vary, but is generally long enough to extend through the support catheter 200 plus at least a distance beyond the distal end of the support catheter 200, while at least a length of the proximal portion 366 remains outside the proximal end of the introducer sheath 400 and outside the patient's body. In some implementations, the overall length of the catheter advancement element 300 is about 145 cm to about 150 cm, and has a working length of about 140 cm to about 145 cm from the proximal tab or hub to the distal-most end 325. The elongated body 360 can have a length at least as long as the lumen portion 222 of the catheter 200, although the elongated body 360 can be shorter than the lumen portion 222, as long as at least a minimum length remains inside the lumen portion 222 when the distal portion of the elongated body 360 extends distally to the distal end of the lumen portion 222 to form an abutment point or abutment area with the catheter. In some implementations, when the distal end region 346 is positioned in its optimal advancement configuration, this minimum length that the elongated body 360 remains within the lumen portion 222 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 implementations, the shaft length of the distal lumen portion 222 can be about 35 cm up to about 75 cm and is shorter than the working length of the introducer sheath, and the insertion length of the elongated body 360 can be at least about 45 cm, 46 cm, 47 cm, 48 cm, 48.5 cm, 49 cm, 49.5 cm up to about 85 cm.

[0145] The length of the elongated body 360 can allow the distal end of the elongated body 360 to reach a cerebral vascular target or occlusion, for example, the internal carotid artery segments including the cervical segment (C1), petrous segment (C2), ligament segment (C3), cavernous segment (C4), clinoid segment (C5), ophthalmic artery segment (C6) and communicating segment (C7) of the internal carotid artery (ICA), and the branches of these segments, including the M1 or M2 segments of the middle cerebral artery (MCA), the anterior cerebral artery (ACA), the anterior temporal branch (ATB) and / or the posterior cerebral artery (PCC). The distal end region of the elongated body 360 can reach these distal target locations, while the proximal end region of the elongated body 360 remains close to or below the level of the sharp turn along the path of insertion. For example, the entry position of the catheter system can be in the femoral artery, and the target occlusion position can be distal to the right common carotid artery, such as in the M1 segment of the right middle cerebral artery. The proximal end region where the slender body 360 transitions to the proximal portion 366 can be retained within a blood vessel that is close to sharply tortuous anatomical structures, such as the carotid siphon, the right common carotid artery, the brachiocephalic trunk, the beginning of the aortic arch into the brachiocephalic artery, and the aortic arch as a transition from the descending aorta. This avoids the insertion of a harder proximal portion 366 or a material transition between the harder proximal portion 366 and the slender body 360, and avoids experiencing a turn in the aortic arch or a turn in the brachiocephalic artery starting from the aortic arch, both of which can be very serious. The length of the distal lumen portion 222 described herein can also be applied to the slender body 360 of the catheter propulsion element.

[0146] The proximal portion 366 can have a length that can also vary. In some implementations, the proximal portion 366 is about 90 cm up to about 95 cm. The distal portion extends distally to the distal end of the lumen portion 222, and the distal portion can include a distal end region 346 that protrudes beyond a length of the distal end of the lumen portion 222 during use of the catheter advancement element 300. As will be described in more detail below, the distal end region 346 of the elongated 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 anatomical configuration of the cerebral blood vessels. The proximal portion 366, which is coupled to the elongated body 360 and extends proximally from the elongated body 360, can be aligned generally side by side with the proximal control element 230 of the catheter 200. The arrangement between the elongated body 360 and the lumen portion 222 can be maintained and help prevent the distal end of the catheter 200 from snagging on tortuous branch vessels during advancement of the catheter 200 through tortuous anatomical structures to reach a target location for treatment in a distal vessel, as will be described in more detail below.

[0147] In some implementations, the elongated body 360 may have a region of relatively uniform outer diameter extending along at least a portion of its length, and the distal end region 346 tapers downward from the uniform outer diameter. The outer diameter of the elongated body 360 may also taper or taper proximally in outer diameter, for example near where the elongated body 360 connects or transitions to the proximal portion 366. The outer diameter of the elongated body 360 does not necessarily have to change outer diameter near where the elongated body 360 connects or transitions to the proximal portion 366. In some implementations, a region of relatively uniform outer diameter may extend along most of the working length of the catheter propulsion element 300, including the proximal portion 366. This first region of uniform outer diameter may transition to a second region of uniform outer diameter distal to the first region. The transition may be combined with 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 being distal to the first region may be used to fill the lumen of a larger caliber catheter without requiring the entire working length of the elongated body to have this larger size. In this implementation, the elongated body 360 can have a distal tapered portion having a diameter that changes from the second uniform diameter region toward the distal opening, and a proximal tapered portion having a diameter that changes from the second uniform diameter region toward the first uniform outer diameter region.

[0148] Depending on the inner diameter of the catheter 200, the difference between the inner diameter of the catheter 200 and the outer diameter of the elongated body 360 may be no greater than about 0.015" (0.381 mm), such as in the range of about 0.003" to 0.015" (0.0762 mm to 0.381 mm) or between 0.006" to 0.010" (0.1524 mm to 0.254 mm) along at least a portion of its length, e.g., at least 10 cm of its length, preferably at least 15 cm of its length. Thus, the difference between the inner diameter of the catheter 200 and the outer diameter of the elongated body 360 may be no greater than about 0.015" (0.381 mm), such as in the range of about 0.003" to 0.015" (0.0762 mm to 0.381 mm) or between 0.006" to 0.010" (0.1524 mm to 0.254 mm). The gap between 60 can result in a space on opposing sides of no greater than about 0.008" (0.2032mm), or can be no greater than about 0.005" (0.127mm), for example, from about 0.001" up to about 0.006" (0.0254mm to 0.1524mm), preferably about 0.002" to about 0.005" (0.0508mm to 0.127mm), and more preferably about 0.003" to about 0.005" (.0762mm to .0508mm).

[0149] The catheter propulsion element 300 has a large outer diameter and a relatively small inner diameter, particularly when the guidewire extends into or through the lumen of the catheter propulsion element 300. The elongated body 360 can have an overall shape profile from the proximal end to the distal end, transitioning from a first outer diameter having a first length to a tapered portion outer diameter having a second length. The first length of the first outer diameter region (i.e., the close fitting region between the distal lumen portion 222 and the elongated body 360) can be at least about 5 cm, or about 10 cm, up to about 50 cm. In other implementations, the close fitting region can extend substantially from the proximal tab or Luer connector 364 to the tapered distal end region 346, which can reach about 170 cm depending on the length of the catheter propulsion element 300. The length of the tapered portion outer diameter of the distal end region 346 can be about 0.5 cm to about 5 cm, about 1 cm to about 4 cm, or about 1.5 cm to about 3 cm, or between 2.0 cm and about 2.5 cm. In some implementations, the length of the distal end region 346 varies depending on the inner diameter of the catheter 200 with which the catheter advancement element 300 is used. For example, for a catheter advancement element 300 sized for use with a catheter 200 having an inner diameter of approximately 0.054" (1.372 mm), the length of the distal end region 346 can be shorter (e.g., 1.2 cm), while for a catheter advancement element 300 sized for use with a catheter 200 having an inner diameter of approximately 0.088" (2.235 mm), the length of the distal end region 346 can be longer (e.g., 2.5 cm). Fig. 10A, the distal end region 346 can be a constant taper that goes from a larger outer diameter of the elongated body 360 (e.g., the distal end marked 344b) down to a second smaller outer diameter at the distal-most terminal end (e.g., the proximal end marked 344a). In some implementations, the constant taper of the distal end region 346 can go from about 0.048" outer diameter to about 0.031" (0.787mm) outer diameter over a length of about 1 cm. In some implementations, the constant taper of the distal end region 346 can go from 0.062" (1.575mm) outer diameter to about 0.031" (0.787mm) outer diameter over a length of about 2 cm. In further implementations, the constant taper of the distal end region 346 can go from 0.080" (2.032mm) outer diameter to about 0.031" (0.787mm) outer diameter over a length of about 2.5 cm. The length of the constant taper of the distal end region 346 can vary, for example, between 0.8 cm and about 2.5 cm, or 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 elongated body 360. For example, the angle of the taper can be between 0.9 and 1.6 degrees relative to the horizontal plane. The angle of the taper can be between 2 degrees and 3 degrees from the centerline of the elongated body 360. The length of the taper of the distal end region 346 can be between about 5 mm and 20 mm or about 20 mm and about 50 mm.

[0150] The distal end region 346 of the elongated body 360 may also be shaped with or without a taper. When the catheter advancement element 300 is inserted through the catheter 200, this distal end region 346 is configured to extend beyond and protrude through the distal-most end 215 of the lumen portion 222, while the more proximal region of the body 360 (i.e., the first length described above) remains within the lumen portion 222.

[0151] As described above, the distal-most end 215 of the lumen portion 222 can be blunt and have no change in size in outer diameter, while the distal end region 346 can be tapered, thereby providing an overall elongated taper geometry for the catheter system. The outer diameter of the elongated body 360 is also close to the inner diameter of the lumen portion 222, so that the step-wise increase in outer diameter from the elongated body 360 to the lumen portion 222 is minimized. When the distal end region 346 is combined with the distal end region of the catheter 200 to follow bends in the vascular anatomy, minimizing such a step-wise increase prevents problems such as the lip formed by the distal end of the lumen portion 222 around the carotid siphon near the ophthalmic artery branch from catching on tortuous neurovasculature. In some implementations, the inner diameter of the lumen portion 222 can be at least about 0.052" (1.321 mm), about 0.054" (1.372 mm), and the maximum outer diameter of the elongated body 360 can be about 0.048" (1.219 mm), such that the difference therebetween is about 0.006" (0.1524 mm). In some implementations, the inner diameter of the lumen portion 222 can be approximately 0.070" (1.778 mm) and the maximum outer diameter of the elongated body 360 can be approximately 0.062" (1.575 mm), such that the difference therebetween is approximately 0.008" (0.2032 mm). In some implementations, the inner diameter of the lumen portion 222 can be approximately 0.088" (2.235 mm) and the maximum outer diameter of the elongated body 360 can be approximately 0.080" (2.032 mm), such that the difference therebetween is approximately 0.008" (0.2032 mm). In some implementations, the inner diameter of the lumen portion 222 can be approximately 0.072" (1.829 mm) and the maximum outer diameter of the elongated body 360 is approximately 0.070" (1.778 mm), such that the difference therebetween is only 2 thousandths of an inch (0.002") / 0.0508 mm. In other implementations, the maximum outer diameter of the elongated body 360 is approximately 0.062" (1.575 mm), such that the difference therebetween is approximately 0.010" (0.254 mm). Although 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 sufficiently flexible to navigate the tortuous anatomy leading to the level of the M1 or M2 arteries without kinking and without damaging the vessel. It is preferred to deliver a catheter having an inner diameter as large as the channel of a larger sized shunt delivery system.

[0152] The dimensions provided herein are approximate and each dimension may have an engineering tolerance or allowable variation limit. The use of the terms "approximately," "approximately," or "substantially" is intended to provide such allowable tolerances for the dimensions referred to. When "approximately," "approximately," or "substantially" is not used with a particular dimension herein, the dimension need not be exact.

[0153] The elongated body 360 of the catheter advancement element 300 can have a lumen 368 having an inner diameter that does not change over the length of the elongated body even as the distal end region 346 tapers. 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 provide a taper. The wall thickness can taper distally along the length of the taper. Thus, the combination of material properties with the wall thickness, angle, and length of the taper all contribute to the overall maximum flexibility of the distal-most end of the distal end region 346. The catheter advancement element 300 undergoes a flexible transition from the distal-most end toward a point of abutment, where the catheter advancement element 300 achieves an outer diameter that differs from the inner diameter of the catheter 200 by no more than about 0.010" (0.254 mm).

[0154] Even though a single lumen passes through the tapered distal end region 346, the inner diameter of the elongated body 360 can be constant along its length. Alternatively, the inner diameter of the elongated body 360 can have a first size passing through the tapered distal end region 346 and a second, larger size passing through the cylindrical section of the elongated body 360. The cylindrical section of the elongated body 360 can have a constant wall thickness or a wall thickness that varies as the inner diameter of the cylindrical section varies. As an example, the outer diameter of the cylindrical section of the elongated body 360 can be approximately 0.080". The inner diameter of the elongated body 360 within the cylindrical section can be uniform along the length of the cylindrical section and can be approximately 0.019". In turn, the wall thickness of this section can be approximately 0.061". As another example, the outer diameter of the cylindrical section of the elongated body 360 can also be approximately 0.080". The inner diameter of the elongated body 360 within the cylindrical section can be non-uniform along the length of the cylindrical section and can gradually increase from a first inner diameter of approximately 0.019" to a larger second inner diameter of approximately 0.021". In turn, the wall thickness can be approximately 0.061" at the first inner diameter region and approximately 0.059" at the second inner diameter region. The wall thickness of the cylindrical portion of the elongated body 360 can be between approximately 0.050" and approximately 0.065". The wall thickness of the tapered distal end region 346 near the proximal marker band location can be the same as the cylindrical portion (between approximately 0.050" and approximately 0.065") and become thinner toward the distal end marker band location. As an example, the inner diameter at the distal opening of a single lumen can be approximately 0.020", while the outer diameter at the distal opening (i.e., the outer diameter of the distal marker band) can be approximately 0.030", resulting in a wall thickness of approximately 0.010", compared to a cylindrical portion wall thickness of up to approximately 0.065". Thus, the outer diameter of the distal tip 346 can taper, as can the wall thickness. The wall thickness of the non-tapered portion of the intermediate segment and the end segment can be approximately 0.050" to approximately 0.065". The wall thickness of the intermediate segment and the non-tapered portion can be constant. The inner diameter of the intermediate segment and the tapered end region can be constant.

[0155] The end segment of the flexible elongated body may have a tapered portion that tapers from the first outer diameter to the second outer diameter distally. The second outer diameter may be about 1 / 2 of the first outer diameter. The second outer diameter may be about 40% of the first outer diameter. The second outer diameter may be about 65% of the first outer diameter. The first outer diameter may be about 0.062" up to about 0.080". The second outer diameter may be about 0.031". The second outer diameter may be about 50% of the first outer diameter, about 40% of the first outer diameter, or about 65% of the first outer diameter.

[0156] The length of the tapered portion can also vary depending on the anatomical structure of the target area. The distal end region 346 can achieve soft, non-traumatic and flexible properties due to material properties rather than changes in outer dimensions to facilitate intravascular navigation to occlusions in tortuous anatomical structures. Additionally or alternatively, the distal end region 346 of the elongated body 360 can have a flexible transition along its length. The most flexible area of ​​the distal end region 346 can be its distal terminal. Move from the distal terminal toward the area close to the distal terminal along the length of the distal end region 346. For example, the distal end region 346 can be formed by a material having a Shore material hardness of no more than 35D or about 62A, and transition to the proximal side near the place formed by a material having a material hardness of no more than 55D and 72D until the proximal portion 366, which can be a stainless steel hypotube, or a combination of material properties and a tapered shape. The material used to form the region of the elongated body 360 can include PEBAX (such as PEBAX 25D, 35D, 55D, 69D, 72D) or a mixture of PEBAX (such as a mixture of 25D and 35D, 25D and 55D, 25D and 72D, 35D and 55D, 35D and 72D, 55D and 72D, where the mixing ratio can range from 0.1% to 50% for each PEBAX durometer), and a lubricating additive compound such as Mobilize (Compound Solutions, Lewiston, Maine). In some embodiments, the material used to form the region of the elongated body 360 can be Tecothane 62A. Incorporating the lubricating additive directly into the polymer elongated body means that a separate lubricating lining (such as a polytetrafluoroethylene lining) does not need to be incorporated. This allows a more flexible element to navigate distal brain anatomy and is less likely to kink. Similar materials can be used to form the distal lumen portion 222 of the catheter 200, thereby providing similar advantages. The flexibility of the distal end region 346 can be achieved by a combination of a flexible lubricating material and a tapered shape. For example, the length of the distal end region 346 can be kept shorter than 2 cm to 3 cm, but due to the change of the flexible material from the farthest side 325 toward the more proximal region at a distance away from the farthest side 325, the best deliverability is maintained. In an implementation, the elongated body 360 is formed by a silicone resin embedded with PEBAX (polyether block amide) designed to maintain the highest degree of flexibility. The wall thickness of the distal end of the lumen portion 222 can also be made thin enough to minimize the lip formed by the distal end of the lumen portion 222 relative to the elongated body 360.

[0157] An advantage of the elongated body 360 over a microcatheter is that it can have a relatively large outer diameter that is only 0.003" to 0.010" (0.0762mm to 0.254mm) less than the inner diameter of the distal lumen portion 222 of the catheter 200 and still remain highly flexible for navigating tortuous anatomical structures. When the gap between the two components is too tight (e.g., less than about 0.003" (0.0762 mm)), the force required to slide the catheter advancement element 300 relative to the catheter 200 may cause damage to one or both of the components and increase risk to the patient during surgery. The gap results in a fit that is too tight and does not provide optimal relative sliding. When the gap between the two components is too loose (e.g., greater than about 0.010" / 0.254 mm), the distal end of the catheter 200 forms a lip that is prone to getting stuck on a carotid dissection or branch vessel (such as around the carotid siphon of the ophthalmic artery branch) during advancement through the tortuous neurovasculature and the piston effect of the withdrawal of the slender body 360 is reduced or eliminated.

[0158] The ID / OD gap between the elongated body 360 and the distal lumen portion 222 can be within this size range (e.g., 0.003" to 0.015" (0.0762mm to 0.381mm) or between 0.006" to 0.010" (0.152mm to 0.254mm) along most of their lengths. For example, the elongated body 360 can have a relatively uniform outer diameter between about 0.048" (1.219mm) to about 0.080" (2.032mm) from the proximal end region to the distal end region until the point where the distal end region 346 begins to taper. Similarly, the distal lumen portion 222 of the catheter 200 can have a relatively uniform inner diameter between about 0.054" (1.372mm) to about 0.088" (2.235mm) from the proximal end region to the distal end region. Thus, along most of their lengths, the difference between their respective inner and outer diameters can be within a gap size range of 0.003" to 0.015" (0.0762mm to 0.381mm). The distal end region 346 of the tapered elongated body 360 will have a larger gap size relative to the inner diameter of the distal end lumen portion 222. However, during use, this tapered distal end region 346 is configured to extend distally of the distal end of the catheter 200 so that a region of the elongated body 360 having an outer diameter sized to match the inner diameter of the distal end lumen portion 222 is positioned within the lumen of the catheter 200, enabling the lip at the distal end of the catheter 200 to be minimized.

[0159] The elongated body 360 can be formed by various materials providing suitable flexibility and lubricity.Example materials include high density polyethylene, 77APEBAX, 33DPEBAX, 42DPEBAX, 46DPEBAX, 54DPEBAX, 69DPEBAX, 72DPEBAX, 90DPEBAX and mixtures thereof or materials of equivalent hardness and lubricity.In some implementations, the elongated body 360 is an unreinforced, non-torsion conduit, which has a relatively large outer diameter designed to fill the lumen into which it is inserted and a relatively small inner diameter minimizing any gap at the distal end of the device.In other implementations, at least a portion of the elongated body 360 can be strengthened to improve navigation and torsion (e.g., braided reinforcement layer).The flexibility of the elongated body 360 can increase toward the distal end region 346, so that the distal end region of the elongated body 360 is softer, more flexible than the proximal region, and is more easily articulated and bent. For example, the more proximal region of the elongated body may have a sufficiently flexible bending stiffness to navigate tortuous anatomical structures (such as the carotid siphon) without kinking. If the elongated body 360 has a braid reinforcement layer along at least a portion of its length, the braid reinforcement layer may terminate at a distance proximal to the distal end region 346. For example, the distance from the end of the braid to the distal-most end 325 may be from about 10 cm to about 15 cm, or from about 4 cm to about 10 cm, or from about 4 cm up to about 15 cm.

[0160] In some implementations, the elongated body 360 can be generally tubular along at least a portion of its length such that the elongated body 360 has a single lumen 368 extending parallel to the longitudinal axis of the catheter advancement element 300 (see FIG. 9A to FIG. 9B and FIG. 10A to FIG. 10B). In one implementation, the size of the single lumen 368 of the elongated body 360 is designed to accommodate a guide wire, but the use of the catheter propulsion element 300 generally eliminates the need for a guide wire. Preferably, the assembled system does not contain a guide wire or a guide wire parked inside the lumen 368 retracted away from the distal opening. The guide wire is designed to be extremely flexible so that they deflect to navigate the sharp turns of the anatomical structure. However, many heavy guide wires have a wire hardness along its longitudinal axis and / or its outer diameter is small enough so that they can find their way through the occlusion, rather than sliding around the occlusion or hanging on the vascular wall dissection to increase the risk of perforation. In some cases, these guide wires may cause perforation and / or dissection of the blood vessel itself. The guide wire tends to be redirected into the branch, rather than being retained in the larger blood vessel. This makes them helpful in selecting branches, but it is problematic for navigating tortuous anatomical structures and following the main flow of blood. Therefore, even if the guidewire has a smaller outer diameter at its distal end region and is very soft at the distal end, the guidewire cannot usually detect occlusions or other structures without trauma, so that the risk of perforation is brought when repeatedly advancing. The guidewire does not deflect when encountering relatively dense objects, such as the proximal side of the occlusion or the dissecting valve. On the contrary, the guidewire is embedded in and penetrates such structures. The catheter propulsion element 300 has the softness, taper and size of finding and / or forming space. For example, when the catheter propulsion element 300 encounters an occlusion (such as an atherosclerotic lesion or an embolus), it can slide between a part of the occlusion and the vessel wall, rather than penetrating it like a guidewire. In the case of partially occluded blood vessels (such as narrowing in the carotid artery), the catheter propulsion element 300 can be non-traumatic and safely found through the narrowed path. The catheter propulsion element 300 will also deflect away from the dissecting valve so as to remain in a larger lumen. The softness, taper and size of the catheter propulsion element 300 allow it to repeatedly pass through the carotid artery and enter the cerebral artery without penetrating these structures or bypassing them relative to these structures. The distal tip region deflects and passes through these structures, allowing the catheter system to be advanced through these structures in a safe manner to the stylet and wedge at or near the distal occlusion site.

[0161] The guidewire 500 may extend generally concentrically from the proximal opening through the single lumen 368 to the distal opening 326 at the distal end 325 of the catheter advancement element 300 (see Fig. 10B). In some implementations, the proximal opening is at the proximal end of the catheter propulsion element 300, so that the catheter propulsion element 300 is configured for an over-the-wire (OTW) method. In other implementations, the proximal opening is a rapid exchange opening through the wall of the catheter propulsion element 300, so that the catheter propulsion element 300 is configured for rapid exchange instead of OTW or in addition to OTW. In this implementation, the proximal opening extends through the side wall of the elongated body 360 and is located at a distance away from the proximal lug or Luer connector 364 and is located at the distal end of the proximal portion 366. The proximal opening can be located at a distance of about 10 cm from the distal end region 346 to about 20 cm from the distal end region 346. In some implementations, the proximal opening can be located near the area where the elongated body 360 is connected to the proximal portion 366, for example, just distal to the end of the hypotube. In other implementations, the proximal opening is located further distally, such as about 10 cm to about 18 cm from the most distal end of the elongated body 360. The proximal opening located closer to the distal end region 346 allows for easier removal of the catheter pusher element 300 from the catheter 200, leaving the guide wire in place for a "quick exchange" type of surgery. Quick exchange can rely on a single person to perform the exchange. The catheter pusher element 300 can be easily replaced with another device using the same guide wire that remains in place. The single lumen 368 of the elongated body 360 can be configured to receive a guide wire 500 in a range of 0.014 "(0.356mm) and 0.018 "(0.457mm), or in a range of 0.014 "and 0.022 "(0.356mm to 0.559mm). In this implementation, the inner lumen diameter of the elongated body 360 can be between 0.020 "and 0.024 "(0.508mm to 0.610mm). The guidewire, catheter advancement element 300, and catheter 200 can all be coaxially assembled for insertion through the working lumen of the guide sheath 400. The inner diameter of the lumen 368 of the elongated body 360 can be 0.019" to about 0.021" (0.483mm to 0.533mm). The distal opening 326 of the lumen 368 can have an inner diameter between about 0.018" to about 0.024" (0.457mm to 0.610mm). The distal opening 326 of the lumen 368 can have an inner diameter between about 0.016" to about 0.028". The size of the distal opening 326 is designed to receive a guidewire of 0.014" to 0.024".

[0162] The area near the distal end region 346 can be tapered so that the outer diameter tapers over a length of about 0.5 cm to about 5 cm, or 1 cm to about 4 cm, or other lengths described elsewhere herein. The larger outer diameter can be at least about 1.5 times, 2 times, 2.5 times, or about 3 times larger than the smaller outer diameter. The distal end region 346 can taper 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 implementations, the distal end region 346 tapers from about 0.080" (2.032 mm) to about 0.031" (0.787 mm). In some implementations, the smaller outer diameter at the distal end of the tapered portion can be approximately 0.026" (0.66 mm) up to approximately 0.040" (1.016 mm), and the larger outer diameter proximal to the tapered portion is approximately 0.062" (1.575 mm) up to approximately 0.080" (2.032 mm). Additionally, the distal end region 346 can be formed of a material having a material hardness (e.g., 62A and 35D) that transitions proximally to increasingly harder materials (e.g., 55D and 72D) up to the proximal portion 366. The first section of the elongated body 360 including the distal end region 346 can be formed of a material having a material hardness of 35D and a length of approximately 10 cm to approximately 12.5 cm. The first section of the elongated body 360 including the distal end region 346 can be formed of a material having a material hardness of 62A and a length of approximately 10 cm to approximately 12.5 cm. The second segment of the elongated body 360 can be formed of a material having a material hardness of 55D and a length of about 5 cm to about 8 cm. The third segment of the elongated body 360 can be formed of a material having a material hardness of 72D and a length of about 25 cm to about 35 cm. The three segments combined can form an insertion length of the elongated body 360, from where the proximal portion 366 is coupled to the elongated body 360 to the terminal end of the distal end region 346, which can be about 49 cm in length.

[0163] The catheter propulsion element 300 can be combined with a reinforcement layer. The reinforcement layer can be a braid or other types of reinforcements to improve the torsionability of the catheter propulsion element 300 and help bridge the parts with such poor flexibility of the catheter propulsion element 300. The reinforcement layer can bridge the transition from the rigid proximal portion 366 to the flexible elongated body 360. In some implementations, the reinforcement layer can be a braid positioned between the PEBAX inner layer and the outer layer. The reinforcement layer can terminate at a distance close to the distal end region 346. The distal end region 346 can be formed by a material with a material hardness of up to about 35D. The first segment can be an unreinforced polymer without a metal reinforcement, and the length is about 4cm until the length of about 12.5cm. The third segment of the elongated body 360 close to the first segment can include a reinforcement layer and can extend a total of about 37cm until the unreinforced distal segment. The proximal end region of the reinforcement layer may overlap with the distal end region of the proximal portion 366 such that there is a small overlap of the hypotube and the reinforcement near the transition between the proximal portion 366 and the elongated body 360 .

[0164] The tubular portion of the catheter propulsion 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 no greater than about 0.015" (0.381mm), or can be no greater than about 0.010" (0.254mm). The at least one snug point of this tubular portion can be a point along the length of the tubular portion. The at least one snug point of this tubular portion can have a length of at least about 5cm up to about 50cm, including, for example, at least about 6cm, at least about 7cm, at least about 8cm, at least about 9cm, at least about 10cm, at least about 11cm, or at least about 12cm up to about 50cm. This length does not need to be uniform, so that the length does not need to be snug along its entire length. For example, the snug point area can include ridges, grooves, slits or other surface features.

[0165] In other embodiments, the entire catheter advancement element 300 can be a tubular element configured to receive a guidewire 500 passing through both the proximal portion 366 and the slender body 360. For example, the proximal portion 366 can be a tubular element having a lumen that is connected to a lumen 368 extending through the slender body 360. In some embodiments, the proximal portion 366 can be a PTFE-coated stainless steel thinned sea wave tube having an outer diameter of 0.026" (0.660mm). In other embodiments, the outer diameter can be between 0.024" (0.610mm) and 0.030" (0.762mm). In some embodiments, such as in the over-the-wire version, the proximal portion 366 can be a thinned sea wave tube connected to the proximal hub or Luer connector 364. The proximal portion 366 can be eccentric or The proximal portion 366 may be a stainless steel hypotube. The proximal portion 366 may be a solid metal wire having a circular or elliptical cross-sectional shape. The proximal portion 366 may be a flat ribbon having a rectangular cross-sectional shape. The ribbon of wire may be bent into a circular, elliptical, C-shaped, or quarter-circular shape, or other cross-sectional shapes along an arc. Whether or not the lumen extends through the proximal portion 366, the proximal portion 366 may have any of a variety of cross-sectional shapes including circular, elliptical, C-shaped, D-shaped, or other shapes. In some implementations, the proximal portion 366 is a hypotube having a D-shape such that the inwardly facing side is planar and the outwardly facing side is rounded. The rounded side of the proximal portion 366 can be shaped to engage with a correspondingly 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 approximately 0.021" (0.533 mm), an outer diameter of approximately 0.0275" (0.699 mm), and an overall length of approximately 94 cm, thereby Provide a working length of about 143cm for the catheter propulsion element 300. Including the proximal Luer connector 364, the catheter propulsion element 300 can have an overall length of about 149cm. In some implementations, the hypotube can be a tapered portion of about 100mm in length, starting with a thickness of 0.3mm from the proximal side and ending with a thickness of 0.10mm to 0.15mm. In a further implementation, the elongated body 360 can be a solid element coupled to a proximal portion 366 without a guidewire lumen.

[0166] exist Fig.9AThe proximal portion 366 is shown as having an outer diameter that is smaller than the outer diameter of the elongated body 360. The outer diameter of the proximal portion 366 need not taper and may also have the same outer diameter as the outer diameter of the elongated body 360. The proximal portion 366 may incorporate a hypotube or other stiffening element that is coated with one or more layers of polymer, resulting in the proximal portion 366 having substantially the same outer diameter as the elongated body 360.

[0167] At least a portion of the solid elongated body 360, such as the elongated distal end region 346, can be formed by or embedded in or attached to a ductile material that is thinned to a smaller size at the distal end. The distal end region 346 can be formed into a desired angle or shape, similar to the use of a guidewire. The extendable length of the elongated body 360 can be at least about 1 cm, 3 cm, 5 cm, and up to about 10 cm, 15 cm or longer. In some implementations, the extendable length can be about 1%, 2%, 5%, 10%, 20%, 25%, 50% or more of the total length of the elongated body 360. In some implementations, the catheter propulsion element 300 can have a working length of about 140 cm to about 143 cm, and the elongated body 360 can have an insertion length of about 49 cm. The insertion length can be a PEBAX portion of about 49.5 cm of the elongated body 360. Therefore, the extendable length of elongated body 360 can be between about 0.5cm and about 25cm or longer. Shape change can be a function of the user manually shaping the extendable length before insertion, or the distal end region 346 can be preformed to a specific angle or curve when manufactured. Alternatively, the shape change can be a reversible and actuable shape change, so that the distal end region 346 forms a shape when actuated by the user, so that the distal end region 346 can be used in a straight form until the user expects the shape change. The catheter propulsion element 300 can also include a forming mandrel extending through the lumen of the elongated body 360, so that the doctor can mold the distal end region 346 into a desired shape when in use. Therefore, moldable distal end region 346 can be incorporated in the elongated body 360 with a guidewire lumen.

[0168] The elongated 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 elongated body 360 can incorporate a proximal portion 366 that is generally aligned side by side with the proximal extension 230 of the catheter 200. The proximal portion 366 of the elongated body 360 can be coaxial or eccentrically positioned with the elongated body 360. The proximal portion 366 of the elongated body 360 can have a lumen extending through it. Alternatively, the portion 366 can be a solid rod or ribbon without a lumen.

[0169] Reference again FIG. 9A to FIG. 9Band FIG. 10A to FIG. 10B , similar to the distal lumen portion 222 of the catheter 200, the elongated body 360 can have one or more radiopaque markers 344 along its length. The one or more markers 344 can vary in size, shape, and location. One or more markers 344 that provide various information about the relative position of the catheter advancement element 300 and its components, such as an end-to-end marker, an end-to-taper marker, an RHV approach marker, a fluorescent protection marker, or other markers, can be incorporated along one or more portions of the catheter advancement element 300. At least one radiopaque marker can identify a tapered end region of the elongated body 360. In some implementations, such as FIG. 10A to FIG. 10B As best shown in FIG. 1 , the distal end region can have a first radiopaque marker 344a and a second radiopaque marker 344b that can be positioned to indicate the boundary between the tapering of the distal end region 346 and the more proximal region of the elongated body 360 having a uniform or maximum outer diameter. This provides the user with information about the optimal extension of the distal end region 346 relative to the distal end of the lumen portion 222 to minimize the lip at this distal end of the lumen portion 222 for advancement through tortuous anatomical structures. In other implementations, such as where the distal end region 346 is not necessarily tapered, but instead has a change in overall flexibility along its length, the second radiopaque marker 344b can be positioned to indicate an area where the relative flexibility of the elongated body 360 (or the distal end region 346 of the elongated body 360) and the distal end of the lumen portion 222 is substantially the same. The marker material can be a platinum / iridium ribbon, tungsten, a platinum or tantalum impregnated polymer, a metal coil or braid, or other radiopaque marker. (One or more) radiopaque markers preferably do not affect the flexibility of the distal end region 346 and the elongated body 360. In some implementations, the radiopaque marker is an extruded PEBAX loaded with tungsten for radiopaqueness. In some implementations, the proximal marker band can be approximately 2.0 mm wide and the distal end marker band can be approximately 2.5 mm wide to provide discernible information about the distal end region 346. In other implementations, the proximal marker is a different construction and / or material from the proximal marker. Additionally, for example, before the catheter system is inserted into the patient's body, the radiopaque marker bands 344a, 344b can be visible to the user without fluoroscopy. The marker bands 344a, 344b can form a contrasting color visible to the user compared to the color of the polymer of the flexible elongated body, such as a black band relative to the white of the polymer. Before the device is inserted into the RHV, the marker bands 344a, 344b can be used to achieve a specific relative extension of the catheter propulsion element 300 relative to the catheter 200.

[0170] The catheter 200 and catheter advancement element 300 (with or without a guidewire) can be advanced as a single unit through two turns in the carotid siphon. Both turns can be passed through or thrown to targets in the cerebral vasculature in a single smooth pass without the need to gradually adjust their relative extensions and without relying on conventional step-by-step advancement techniques with conventional microcatheters. The catheter 200 with the catheter advancement element 300 extending therethrough allows the user to consistently advance them from the first bend in the siphon through the second bend, beyond the terminal cavernous carotid arteries into the ACA and MCA in the same relative position. Importantly, advancement of the two components can be performed in a single smooth movement through the two bends without requiring any changes in the position of the hand.

[0171] The catheter propulsion element 300 can be juxtaposed relative to the catheter 200, which provides the best relative extension between the two components for a single smooth advancement. The catheter propulsion element 300 can be positioned through the lumen of the catheter 200 so that the distal end region 346 of the catheter propulsion element 300 just extends beyond the most distal end 215 of the catheter 200. The distal end region 346 of the catheter propulsion element 300 eliminates the stepped transition between the inner member and the outer catheter 200, so that the problem of getting stuck in the vascular system region of the branch vessels is avoided, so that the catheter 200 can easily pass through the angled multiple turns of the carotid siphon. For example, the best relative extension can be the distal end region 346 of the elongated body 360 that just extends to the far end 215 of the catheter 200. During advancement, the length of the distal end region 346 extending to the far end 215 of the catheter 200 can be between 0.5cm and about 4cm. This juxtaposition can be a locking engagement with a mechanical element or simply by the user to keep the two components together. The mechanical locking element can be a fixed or removable mechanical element 605, which is configured to be connected to one or more of the catheter 200, the catheter advancement element 300 and the guide wire 500. When connected, the mechanical locking element 605 can slide at least along the length of the system component so that the mechanical attachment is adjustable. The mechanical locking element 605 can be a disposable feature or a reusable component for being connected to at least a portion of the shaft or a more proximal portion of the component, such as the Luer connector or the hub at the proximal end of the component. In some implementations, the mechanical locking element 605 can be clamped on the catheter 200 and the catheter advancement element 300 with a desired relative position so that the two can be advanced together without accidentally changing the relative position. If desired, the relative position can be changed while the mechanical locking element 605 is clamped on the catheter 200 and the catheter advancement element 300. Mechanical locking element 605 can be additionally clamped on the area of ​​guidewire 500 extending through catheter advancement element 300, so that the relative position of all three parts can be maintained during advancement, until relative sliding motion is expected. In a further implementation, according to the stage of the method being performed, the clamping position of mechanical locking element 605 can be changed to the different combinations of parts (for example, catheter advancement element and guidewire) from the first combination with parts (for example, catheter, catheter advancement element and guidewire) engagement. In a further implementation, guidewire 500 is fixed relative to catheter advancement element 300 via the rotary hemostatic valve connected to proximal hub 434, and catheter advancement element 300 is fixed to catheter 200 via a separate mechanical locking element 605. No matter the relative position of parts is fixed by mechanical element, the combination of mechanical elements or by the user, the proximal part 264 of each of catheter 200 and catheter advancement element 300 (and guidewire 500, if present) is configured to be maintained at a single point by the user.For example, in the case of manual advancement and / or retraction of the catheter and catheter advancement element, the single point may be only between the user's index finger and thumb.

[0172] These parts can be advanced together with guide wire, advanced on the guide wire of pre-positioning, or there is no guide wire at all.In some implementations, guide wire can be preassembled with catheter advancement element 300 and catheter 200, so that guide wire extends through the lumen of catheter advancement element 300, and guide wire is loaded by the lumen of catheter 200, all before being inserted in the patient.Preassembled parts can be inserted into sheath 400 simultaneously, and advance upwards through and through the turn of carotid siphon together.Guide wire can be located in the lumen 368 of catheter advancement element 300 and parked on the near side of tapered distal end region 346 or the near side of distal end, for the potential use when the catheter advancement element without guide wire does not reach the target position.For example, the distal end of guide wire 500 can be positioned at the proximal about 5cm to about 40cm of the distal end region 346 of catheter advancement element 300, or about 20cm to about 30cm.In this position, guide wire can not interfere with the performance or function of catheter advancement element. The guidewire can be positioned in the lumen of the catheter advancement element so that in the step of advancing the assembled system of the device together, the distal end of the guidewire is in the catheter advancement element, and when navigation is required, the distal end of the guidewire can extend from the distal opening 326 of the catheter advancement element. In one example, the rescue guidewire is parked in the lumen of the catheter advancement element, wherein the distal end of the guidewire is about 0 cm to about 40 cm proximal to the distal end of the catheter advancement element or about 5 cm to about 35 cm proximal to the distal end of the catheter advancement element or about 7 cm to about 30 cm, preferably about 10 cm proximal to the distal end of the catheter advancement element. The guidewire in this parked position can provide additional support for the proximal portion of the system without affecting the flexibility and performance of the distal portion of the system.

[0173] Standard neurovascular interventions, as well as almost all endovascular interventions, are based on the concept of a guidewire guiding a catheter to a target location. Guidewires are typically preformed and often find side branches that deviate from the target location, where the guidewires bunch or sag, causing time-consuming hassles during intervention, which often requires the operator to repeatedly change the direction of the guidewire to overcome. In addition, this tendency of the guidewire to enter the side branch can be dangerous. In neuroanatomical structures, guidewires are typically 0.014" to 0.018" (0.356mm to 0.457mm), and dissecting flaps or small branches that accommodate this size are found and often traumatized, which can lead to small hemorrhages or dissections and further occlusions. In sensitive areas like the brain, these events can be catastrophic. The tendency of the guidewire to bunch and sag can also cause the leading edge of the guidewire to be pushed forward on its own or as part of a triaxial system, thereby forming a dissection plane and causing trauma to small vessels.

[0174] In contrast, the catheter propulsion element 300 described herein preferably stays in the larger lumen of the conduit vessel. Even taking into account the highly tortuous anatomical structures and curves being navigated, the catheter propulsion element 300 is delivered to the largest lumen within the anatomical structure. The catheter propulsion element 300 can preferentially occupy a larger lumen at a bifurcation or dissecting valve, while also following the flow of maximum blood flow, thereby maintaining the overall direction and angle of the tumor-bearing vessel. When observing the standard anatomical structures found in the cerebral vasculature, the Willis circle is supplied by two vertebral arteries and two carotid conduit arteries. Since these four arteries are access points to the cerebral anatomical structure, the route of the catheter propulsion element 300 can be identified and has been verified in a standard cerebral anatomical structure model.

[0175] In the anterior circulation, the arterial access point for cerebral endovascular surgery is the internal carotid artery (ICA), and the catheter pusher element can guide the large-caliber catheter to the M1 segment of the middle cerebral artery (MCA) by bypassing the anterior communicating artery (ACA) and the anterior temporal branch (ATB). The very flexible nature of the catheter pusher element 300 is combined with the distal flexibility of most cerebral catheters to allow delivery through sharp twists and turns. Independent of the tortuous nature of the arterial route, the catheter pusher element 300 tends to navigate the turn and deliver from the parent artery to the largest daughter artery of the mother artery, for example, the ICA segment of the MCA to the M1 segment. The M2 horizontal branch of the M1 can be variable, but it is usually seen that there are two main M2 branches (upper branch and lower branch), and "equal" or "unequal" bifurcations can be seen according to the anatomical structure (which may be significantly different between different patients). If the caliber of the M2 branch has a similar size and angle, the catheter pusher element 300 can adopt one of the two branches. If the target for catheter placement is not in a favorable angle or size of artery, the catheter advancement element 300 may be curved (eg, via shaping of a malleable distal tip) and guided, or a guidewire may be used.

[0176] In some anatomical structures where the M2 bifurcation size is "uniform", the forward and backward motion can assist in selecting one branch and then another branch, while still avoiding the need or use of a curved distal end of a wire or catheter advancement element. The forward and backward motion can allow the catheter advancement element to be guided into either branch of the M2. Even if the catheter advancement element is initially straight, a certain curvature will be achieved to assist in guiding the catheter advancement element into the branch vessel. Therefore, when the operator encounters an M2 bifurcation and desires to cannulate either branch of the evenly separated bifurcation, the catheter advancement element can be used without a guide wire to select either branch.

[0177] Therefore, major channels, such as the ICA, the middle cerebral artery and its branches in the anterior circulation, will naturally be the preferred paths for the catheter pusher element and subsequent large-bore catheter delivery (via access from the ICA). A similar phenomenon can occur in the posterior circulation, which is accessed via the vertebral arteries that emanate from the subclavian arteries on the right and left sides. The catheter pusher element will also occupy the major channels in this circulation by passing through the vertebral arteries to the basilar artery and the major branches of the basilar artery (the posterior cerebral artery and the superior cerebellar artery in the posterior circulation).

[0178] Using a catheter pusher element to navigate can provide maximum deliverability with minimal vascular trauma. The catheter can produce a "scraping" effect in curved blood vessels because the blunt end of the large-caliber catheter tends to present a larger bend when the blood vessel is rounded when pushed by the operator. This blunt end can groove or "scrape" a larger curve with its sharp edge, increasing the risk of dissection along the anatomical plane in multi-layer medium or large arteries or veins (see, e.g., Catheter and Cardiovascular Intervention, February 2014; 83 (2): 211-20). The catheter pusher element can be used to minimize the edge of these catheters. The catheter pusher element is positioned in the lumen of the large-caliber catheter so that the tapered portion mark of the catheter pusher element is optimally aligned with the distal end mark of the catheter, so that the edge is minimized and thereby eliminates the "scraping" when the large-caliber catheter is pushed through the turn of the blood vessel. This is particularly useful for brain anatomical structures. Treatment away from the carotid siphon, and in particular treatment of the ophthalmic artery away from the sharp tortuosity of the last turn of the carotid siphon's "S-turn," the "front knee" of the carotid siphon, which is typically considered a portion of the terminal internal carotid artery (ICA), can be improved using the access system described herein. The detail of the catheter advancement element properly aligned within the large-bore catheter relative to the tapered portion marking of the catheter advancement element (the "end to tapered portion" position marked by the distal end marking) maximizes the likelihood of avoiding scraping and cutting on the ophthalmic artery during manual advancement of the catheter system. The tapered portion marking of the catheter advancement element can be positioned at or past the beginning of the ophthalmic artery to minimize these deleterious effects and allow the large-bore catheter to pass through the ophthalmic artery without incident. In the relatively straight section that is common after passing through the siphon, the large-bore catheter can be advanced on the catheter advancement element, which still serves as a guiding element to reach the target. The transition between the catheter advancement element and the distal edge of the large bore catheter is not dramatic (especially compared to the step change present with a typical microcatheter or guidewire), which does not prevent severing of branches such as the ophthalmic artery. The catheter advancement element allows the large bore catheter to be maneuvered to a distal site without the use of a microcatheter or guidewire.

[0179] The system described herein can but need not be combined with a guide wire. And, if a guide wire is used, there is no need to separately advance the guide wire (i.e., remove the sheath) to the target treatment site. Therefore, the system described herein can be combined with a relatively large-caliber catheter that is delivered with a guide wire without interfering with the anatomical structure, reducing the risk of stroke and the downstream effects caused by occlusive rupture, and having improved efficiency. Additionally, the system described herein is a single-operator system that allows the operator to work under a single RHV, and in the case of a spinal component, all elements for navigating the anatomical structure can be manipulated by "pinching" with a single hand. This can be referred to as a "single point".

[0180] Any shunt described herein may be used with any device delivery system, including but not limited to those described herein, and may be delivered via an access catheter, including but not limited to those described herein.

[0181] How to use

[0182] The access catheter system, shunt and delivery system described herein can be used for access and treatment of intracranial aneurysms and cerebral aneurysms. Compared with conventional systems, the access catheter system provides a single point of manipulation at the base sheath for the various tools used in the method, thereby providing improved safety, ease of use and manipulation of a single operator. These catheter systems provide easy and fast access to the target site, even through tortuous anatomical structures to reach the target lesion. The shunt and delivery system described herein provide improved, more accurate and safer aneurysm treatment. In addition, due to the geometry of the device against the wall, the shunt described here potentially reduces the incidence of complications.

[0183] A method of treating a cerebral or intracranial aneurysm is now described. The method may include a shunt and a shunt delivery system that are advanced over a guidewire (or not over a guidewire) through an outer catheter that extends through a base sheath. The catheter may be a conventional full-length catheter, but is preferably a catheter having a larger diameter distal lumen portion 222 that is coupled to a smaller diameter proximal control element 230, such as FIG. 9A to FIG. 9B 4, so that a single point of manipulation can be performed at the hub of the base sheath. The base sheath 400 can be introduced into a blood vessel (e.g., the femoral artery) and advanced toward an intracranial or cerebral vessel having an aneurysmal segment to at least the level of the common carotid artery. The outer catheter 200 is advanced through the hub (e.g., RHV 434) on the base sheath 400 until the distal end of the catheter 200 exits the distal opening 408 of the base sheath 400 (see FIG. 4). Fig.11A). The catheter 200 can be advanced to the high ICA. The outer catheter 200 can be part of a catheter system that includes an inner catheter 300 having a tapered end region 346 extending distally toward the distal end of the outer catheter 200. With the assistance of the inner catheter 300, the outer catheter 200 can be navigated through the carotid siphon CS toward the aneurysm A. The outer catheter 200 and the inner catheter 300 can be advanced until at least a portion of the tapered end region 346 of the inner catheter 300 is positioned across the target aneurysm, such as Fig.11A Alternatively, the guidewire 500 can be advanced through the hub on the base sheath 400 and advanced until the guidewire 500 is positioned across the aneurysm A while the outer catheter 200 remains parked between the distal end of the base sheath 400 and the aneurysm A (e.g., at or near the carotid siphon CS).

[0184] The distal end region of the outer catheter 200 can be advanced over the inner catheter 300 and positioned across the aneurysm A. The inner catheter 300 can be withdrawn from the outer catheter 200 and the outer catheter 200 is maintained in place across the aneurysm (see Fig. 11B ). The outer catheter 200 can have an ID between 2.0 mm and 3.0 mm configured to receive the shunt 700 installed within the shunt delivery system 800. The shunt delivery system 800 and the shunt 700 can be advanced (e.g., if the catheter 200 is a partial length catheter, through the hub of the outer catheter 200 or the hub of the base sheath 400 and into the distal tubular portion of the catheter 200) to the distal end region of the outer catheter 200. The outer catheter 200 can be withdrawn to expose the shunt delivery system 800 while maintaining the shunt delivery system 800 across the aneurysm A (see Fig. 11C ). Then, the shunt 700 of the shunt delivery system 800 may be deployed across the aneurysm A (see Fig.11D ).

[0185] The shunt delivery system 800 can include an inner core member 820 and an outer restraining sleeve 810. The shunt 700 can be mounted on the inner core member 820 and constrained by the outer restraining sleeve 810 during delivery. The shunt 700 constrained by the outer restraining sleeve 810 can be delivered through a delivery catheter having an inner diameter between 2.0 mm and 3.0 mm. For example, referring to Fig.11D Deployment of the shunt 700 across the aneurysm A may be accomplished by retracting the outer restraining sheath 810 of the delivery system 800 to expose the shunt 700 while the inner core element 820 remains in position distal to the aneurysm A.

[0186] The flow splitter 700 can be any of those previously described. For example, the flow splitter can be a laser cut expandable metal tube. The flow splitter can be formed by a first expandable tube and a second expandable tube, each of which is a laser cut metal tube. The first expandable tube can be a laser cut metal tube and the second expandable tube can be a braided tube. Alternatively, the first expandable tube can be a laser cut metal tube and the second expandable tube can be a polymer sleeve. The flow splitter can have a composite construction. The composite construction can include two end sections constructed from laser cut tubes and a braided middle section.

[0187] Material

[0188] One or more components of the catheters, delivery systems, and shunts described herein may comprise or be made of a variety of materials, including one or more of metals, metal alloys, polymers, metal-polymer composites, ceramics, hydrophilic polymers, polyacrylamides, polyethers, 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, combinations thereof, or the like, or other suitable materials.

[0189] Some examples of suitable cutting tubes or flat metal materials include Nitinol, layered tubes with Nitinol on the outside and inner core of a radiopaque material such as Tantalum, Platinum, Iridium, Gold, alloys, etc. Additionally, the material may be cobalt, cobalt alloys, or stainless steel.

[0190] Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steels; low carbon steels; nickel-titanium alloys, such as linear elastic and / or superelastic nitinol; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as 625, UNS:N06022, such as UNS:N10276, such as other alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as 400, 400, 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g. UNS: R30035, such as etc.), nickel-molybdenum alloys (e.g. UNS: N10665, such as ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.); platinum-rich stainless steel; titanium; combinations thereof; etc.; or any other suitable material, and as described elsewhere herein.

[0191] The lining material of the catheter described herein can include low friction polymers, such as PTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene), PTFE (Tecoflex) with a polyurethane layer. The reinforcing layer material of the catheter described herein can be combined to provide mechanical integrity for applying torque and / or prevent flattening or kinking, and the material is, for example, metal, including stainless steel, nitinol, nitinol braid, spiral ribbon, spiral wire, cut stainless steel, etc., or hard polymers, such as PEEK. The reinforcing fiber material of the catheter described herein can include various high-toughness polymers, such as Kevlar, polyester, inter-para-aramid, PEEK, single fiber, multi-fiber bundle, high tensile strength polymer, metal or alloy, etc. The outer jacket material of the catheter described herein can provide mechanical integrity and can be made of a variety of materials, such as polyethylene, polyurethane, PEBAX, nylon, Tecothane, etc. Other coating materials of the catheter described herein include polyparaxylene, polytetrafluoroethylene, silicone, polyimide-polytetrafluoroethylene, etc. The liner may also include different surface treatments (or surface finishes), such as pits, bumps, ridges, grooves. The surface treatments may be randomly arranged, linearly arranged, spirally arranged, or arranged using a specific pattern along the length of the catheter. It is also contemplated that the liner may include a mixture of different surface treatments, for example, one section may have pits, another section may have grooves, and so on. Additionally, surface treatments may be incorporated along the entire length of the catheter or only in sections of the catheter. It is also contemplated that the liner may also include an electrosprayed coating, whereby materials may be incorporated into the liner. Examples of materials may include low friction materials as described above. Alternatively, the electrosprayed or electrospun layer may incorporate a beneficial agent that is released from the coating when exposed to blood or clot compression, for example, the beneficial agent may be tissue plasminogen activator (tPA) or heparin encapsulated in alginate.

[0192] Implementations describe catheters and delivery systems and methods for catheter delivery to target anatomical structures. However, although some implementations are described specifically for catheter delivery to the target vessel (such as cerebral blood vessels) of neurovascular anatomical structures, the implementation is not limited thereto, and some implementations may also be applicable to other purposes. For example, catheters may be suitable for delivery to different neuroanatomical structures, such as subclavian vessels, spinal vessels, carotid vessels, and coronary anatomical structures or peripheral vascular anatomical structures, only listing several possible applications. It should also be understood that although system described herein is described as being able to be used for treating specific illness or pathology, the illness or pathology treated may change and are not intended to be limited.

[0193] In each implementation, the reference figures are described. However, some implementations can be implemented without one or more of these specific details, or in combination with other known methods and configurations. In the description, many specific details are set forth, such as specific configurations, sizes and processes in order to provide a thorough understanding of the implementation. In other cases, in order to avoid unnecessary fuzzy descriptions, well-known processes and manufacturing techniques are not particularly described in detail. Throughout this specification, references to "one embodiment", "embodiment", "one implementation", "implementation", etc. mean that the specific features, structures, configurations or characteristics described are included in at least one embodiment or implementation. Therefore, the phrases "one embodiment", "embodiment", "one implementation", "implementation", etc. throughout this specification do not necessarily relate to the same embodiment or implementation. In addition, specific features, structures, configurations or characteristics can be combined in any suitable manner in one or more implementations.

[0194] The use of relative terms throughout the specification may indicate a relative position or direction. For example, "distal" may indicate a first direction away from a reference point. Similarly, "proximal" may indicate a position in a second direction opposite to the first direction. The reference point used herein may be an operator, so the terms "proximal" and "distal" are references to the operator using the device. The region of the device closer to the operator may be described as "proximal" in this article and the region of the device further away from the operator may be described as "distal" in this article. Similarly, the terms "proximal" and "distal" may also be used herein to refer to the anatomical position of the patient observed along the insertion path from the perspective of the operator or from the perspective of the entry point or from the entry point of the system. Therefore, the position of the proximal side may mean a position closer to the entry point of the device in the patient's body along the insertion path toward the target, and the position of the distal side may refer to a position farther away from the entry point of the device in the patient's body along the insertion path toward the target position. However, such terms are provided to establish a relative reference system and are not intended to limit the use or orientation of the catheter and / or delivery system to the specific configurations described in each implementation.

[0195] The word "about" means a range of values ​​including the specified value that one of ordinary skill in the art would consider to be reasonably similar to the specified value. In the embodiments, about means within the standard deviation using measurements generally accepted in the art. In the embodiments, about means a range extending to + / - 10% of the specified value. In the embodiments, about includes the specified value.

[0196] Although this specification contains many details, these details should not be interpreted as limitations on the scope of protection or the scope that can be claimed, but should be interpreted as descriptions of features peculiar to a particular embodiment. Certain features described in the context of a separate embodiment in this specification may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations, and even 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 for a sub-combination or a variant of a sub-combination. Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order, or requiring all operations shown to be performed to achieve the desired result. Only a few examples and implementations are disclosed. The described examples and implementations and other implementations may be varied, modified, and enhanced based on the disclosed content.

[0197] In the above description and claims, phrases such as "at least one of..." or "one or more of..." may appear after a conjunction list of elements or features. The term "and / or" may also appear in a list of two or more elements or features. Unless the context of its use implicitly or explicitly contradicts, such phrases are intended to mean any element or feature listed individually, or a combination of any listed element or feature with any other listed element or feature. For example, the phrases "at least one of A and B"; "one or more of A and B"; and "A and / or B" are each intended to mean "A alone, B alone, or A and B together". A similar interpretation also applies to lists containing three or more items. For example, the phrases "at least one of A, B, and C" A, B, and C, one or more and "A, B, and / or C" are each intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together".

[0198] The term “based on” as used above and in the claims is intended to mean “based, at least in part, on” such that unrecited features or elements are also permissible.

[0199] The components of the systems disclosed herein may be packaged together in a single package or individually. The finished package will be sterilized using a sterilization method (such as ethylene oxide or radiation), and labeled and boxed. Instructions for use may also be provided in the box or via an Internet link printed on the label.

Claims

1. A flow divider, comprising: a self-expanding tubular member comprising a plurality of expandable units, each of the expandable units comprising interconnected struts and bridges, wherein the tubular member has a constrained configuration having a first outer diameter of at least 1.0 mm sized for delivery using a shunt delivery system and an expanded configuration having a second outer diameter greater than the first outer diameter, and The tubular member comprises a proximal end region, a distal end region and a middle region between the proximal end region and the distal end region, wherein when the tubular member is in an expanded configuration, at least the middle region of the tubular member is laser cut to have a material coverage of at least 25%.

2. A diverter according to claim 1, wherein the interconnected struts and bridge members of each expandable unit include two pairs of struts, each strut in the two pairs of struts having an outer edge, wherein the outer edge of the first strut in the first pair of struts is interconnected to the outer edge of the second strut in the first pair of struts through one of the bridge members.

3. A flow divider according to claim 2, wherein the first strut of the first pair of struts is connected to the first strut of the second pair of struts at a center bend, and the second strut of the first pair of struts is connected to the second strut of the second pair of struts at a center bend, wherein the circumferential height from the center bend of the first pair of struts to the outer edge of the first pair of struts is Y, and the axial distance from the center bend of the first pair of struts to the outer edge of the first pair of struts is X, and wherein the diagonal of the rectangle defined by X and Y is equal to the length of the first strut. The flow diverter of claim 3 , wherein a ratio of the length of the first strut to the circumferential height of the first strut is between 1 and 5.

5.

5. The flow diverter according to any one of claims 2 to 4, wherein each of the pair of struts are arranged parallel to each other and spaced apart from each other by an axial distance, thereby defining a V-shaped opening of the expandable unit.

6. The flow diverter of claim 5, wherein the two pairs of struts are interconnected to form a peak on a first end of the expandable unit and a corresponding valley on a second end of the expandable unit.

7. The flow diverter of claim 6, wherein the plurality of expandable cells are arranged in a circumferential ring and each peak in a circumferential ring of expandable cells is circumferentially aligned with each peak in an adjacent circumferential ring of expandable cells.

8. A flow diverter according to claim 6 or 7, wherein bridges connect peaks of expandable cells of a first circumferential ring to valleys of expandable cells of an adjacent second circumferential ring.

9. A shunt according to any one of the preceding claims, wherein the middle region has different properties than one or both of the proximal and distal end regions.

10. A shunt according to any one of the preceding claims, wherein the middle region has a greater material coverage than one or both of the proximal and distal end regions.

11. The shunt of any of the preceding claims, wherein one or both of the proximal and distal end regions are laser cut to have less material coverage than the middle region.

12. A shunt according to any one of the preceding claims, wherein when the tubular member is in the expanded configuration, the material coverage of the middle region is between 25% and 35%, and the material coverage of the proximal end region and the distal end region is less than the material coverage of the middle region.

13. A shunt according to any one of the preceding claims, wherein at least one of the proximal end region, the middle region and the distal end region comprises at least one radiopaque marker.

14. A flow diverter according to any one of the preceding claims, wherein the length of the flow diverter in the constrained configuration differs from the length of the flow diverter in the expanded configuration by less than 1%.

15. A flow diverter according to any one of the preceding claims, wherein a length of the flow diverter in the constrained configuration differs from a length of the flow diverter in the expanded configuration by less than about 5%.

16. A flow diverter according to any one of the preceding claims, wherein a length of the flow diverter in the constrained configuration differs from a length of the flow diverter in the expanded configuration by less than about 10%.

17. A shunt according to any one of the preceding claims, wherein the first outer diameter is between 1.5 mm and 2.5 mm, and wherein the second outer diameter is between 2.0 mm and 6.0 mm.

18. A flow diverter according to any one of the preceding claims, wherein the length of the flow diverter in the constrained configuration is between 10 mm and 35 mm.

19. A flow diverter according to any one of the preceding claims, wherein the plurality of expandable cells of the tubular member are arranged in between 10 and 50 circumferential rings.

20. A flow diverter according to any one of the preceding claims, wherein the pitch of the middle region is between about 0.25 mm and 0.40 mm, the pitch corresponding to the length of the bridges of the expandable cells of the middle region.

21. The shunt of claim 20, wherein the spacing of one or both of the proximal and distal end regions is approximately 0.45 mm to 0.75 mm, the spacing corresponding to the length of the bridge of the expandable unit of the proximal or distal end region.

22. A shunt according to any of the preceding claims, wherein the plurality of expandable units form a row extending parallel to the longitudinal axis of the tubular member between the proximal end and the distal end of the tubular member, the row of expandable units being aligned in a peak to valley manner.

23. The flow diverter of claim 22, wherein the tubular members comprise 4 to 10 rows.

24. A shunt according to claim 22 or 23, wherein at least the distal end region comprises a track formed by bridges interconnecting the plurality of expandable units within a row.

25. The shunt of claim 24, wherein the track enables re-insertion of the distal end region in a delivery system after at least partial deployment of the distal end region.

26. A shunt according to any one of the preceding claims, wherein one or both of the proximal end region and the distal end region comprise a braided or woven construction.

27. A flow diverter according to any one of the preceding claims, wherein the interconnected struts are connected by hinges into a plurality of V-shapes.

28. The flow diverter of claim 27, wherein a line connecting radially adjacent hinges passes through at least 4 cells in the middle region.

29. The shunt of claim 28, wherein the lines connecting radially adjacent hinges in the proximal and distal regions pass through fewer cells than in the middle region.

30. A shunt according to any of the preceding claims, wherein the bridge located in the middle region is shorter than the bridges located in the distal end region and the proximal end region, and wherein the struts in the middle region, the distal end region and the proximal end region are substantially the same in length and configuration.

31. A flow splitter according to any one of the preceding claims, wherein the bridge is positioned parallel to a central axis of the flow splitter.

32. A method for treating an intracranial aneurysm or a cerebral aneurysm, the method comprising: The catheter system is advanced through the base sheath toward the intracranial blood vessel or cerebral blood vessel having the aneurysm segment, the catheter system comprising: an inner catheter having a tubular elongated body with a single lumen and a flexible distal tapered end region; and an outer catheter having a catheter lumen and a distal end; positioning the tapered end region of the inner catheter distal to the distal end of the outer catheter; spanning the vessel segment having the aneurysm with at least a portion of the tapered end region of the inner catheter; advancing the outer catheter over the inner catheter and positioning a distal end region of the outer catheter across the lesion; withdrawing the inner catheter from the catheter lumen and maintaining the outer catheter in place across the aneurysm; advancing a shunt delivery system including a shunt through the catheter lumen to a distal end region of the outer catheter; withdrawing the outer catheter while maintaining the shunt delivery system in place; and The flow diverter is deployed across the segment having the aneurysm.

33. A method of performing a medical procedure at a treatment site in a patient's brain, the method comprising: Positioning a system of apparatus into a propulsion configuration, the system of apparatus comprising: a catheter having a catheter lumen, an inner diameter, and a distal end; and an inner member sized and shaped to slide within the lumen of the catheter, wherein the inner member defines a single lumen and has a distal portion, wherein the distal portion has a first outer diameter that tapers distally to a second outer diameter that is smaller than the first outer diameter, and wherein the flexibility of the inner member transitions from a proximal end of the inner member to a distal end of the inner member, the distal end of the inner member being more flexible than the distal end of the catheter, and wherein when positioned in the advancing configuration, the inner member coaxially extends through the catheter lumen until a distal portion of the inner member is positioned distal to a distal end of the catheter; advancing the catheter and the flexible inner member to a target location of an access point when the system of the device is positioned in the advancement configuration; positioning the catheter at the treatment site, the treatment site comprising an aneurysm; removing the inner member from the patient; and The aneurysm is treated via the catheter.

34. The method of claim 33, wherein the treating step comprises delivering a flow shunt to the aneurysm via the catheter.

35. A shunt delivery system comprising: a flow shunt having a tubular structure and configured to treat an aneurysm in an intracranial blood vessel, the flow shunt comprising a constrained configuration having a first outer diameter and an expanded configuration having a second outer diameter; An inner core member comprising: an elongated shaft including a recessed region proximate a distal end region of the elongated shaft, the recessed region being sized to receive the tubular structure of the shunt when the shunt is in the constrained configuration; as well as an atraumatic distal end region distal to the recessed region, the distal end region having a tapered portion from a first outer diameter of the elongated shaft to a second outer diameter of the elongated shaft, wherein the first outer diameter of the elongated shaft is greater than the outer diameter of the recessed region; and an outer limiting sleeve having an inner diameter sized to receive the inner core member and the shunt in the constrained configuration, wherein the outer limiting sleeve can be retracted at least a distance to deploy the shunt.

36. The shunt delivery system of claim 35, wherein the inner diameter of the restricting sleeve is sized to the first outer diameter of the elongated shaft to reduce the annular space at the leading end of the shunt delivery system.

37. The shunt delivery system of claim 35 or 36, wherein the distal tip region comprises at least one radiopaque marker at the distal end.

38. The shunt delivery system of claim 37, wherein the distal tip region comprises a second radiopaque marker, wherein the second radiopaque marker is positioned to identify the tapered portion.

39. A flow diverter comprising: a self-expanding tubular member having a proximal end, a distal end, and a longitudinal axis, the tubular member having a constrained configuration having a first outer diameter sized for delivery and an expanded configuration having a second outer diameter greater than the first outer diameter, wherein the tubular member comprises a plurality of expandable cells, each cell comprising interconnected struts and bridges arranged in a circumferential ring, the circumferential ring forming a row of expandable cells extending parallel to the longitudinal axis between a proximal end and a distal end of the tubular member, the rows of expandable cells being nested in a peak-to-valley manner, wherein the tubular member has a proximal end region near the proximal end of the tubular member, a distal end region near the distal end of the tubular member, and a middle region between the proximal end region and the distal end region, Wherein at least the distal end region comprises at least one track formed by bridges interconnecting each circumferential ring of expandable cells within a single row.

40. The shunt of claim 39, wherein the at least one track enables reinsertion of the distal end region within the delivery system after the distal end region has been at least partially deployed from the delivery system.

41. A flow diverter according to claim 39 or 40, wherein at least a mid-region of the tubular member is laser cut to have at least 25% material coverage when the tubular member is in the expanded configuration.

42. A flow splitter configured to expand from a constrained state to an expanded state, the flow splitter comprising: a first tube of superelastic material formed from a plurality of cells having a first material coverage; as well as a second tube of superelastic material formed from a plurality of cells having coverage of the second material, The second tube is positioned inside the first tube so that when the diverter is in the expanded state, the overlap of the multiple expandable units of the first tube and the multiple expandable units of the second tube forms a third material coverage greater than the first material coverage and the second material coverage.

43. The flow splitter of claim 42, wherein the second tube is locked in place inside the first tube by features in the cut pattern of at least one of the first tube and the second tube.

44. The flow splitter of claim 43, wherein the feature comprises a slot in the first tube or the second tube and a tab configured to protrude into the slot to lock the first tube and the second tube together.

45. A flow splitter according to claim 43 or 44, wherein the feature includes a hole in the first tube or the second tube and a ductile disc configured to be inserted into the hole to lock the first tube and the second tube together.

46. ​​The flow diverter of any one of claims 42 to 45, wherein at least one of the first tube and the second tube is non-woven and laser cut.

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