Device for treating aneurysms

Abstract

The methods and apparatus for the treatment of aneurysms include a frame for stent-assisted aneurysm coil embolization, an endovascular flow diverter, and an intrasaccular flow diverter. The device includes a cover with a porosity specified for the treatment of intracranial aneurysms. The cover may be made of an electrospun polymer.

Description

[Technical field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Applications Nos. 63 / 313487, 63 / 313635, and 63 / 313652, all filed on February 24, 2022. The entire disclosures of these applications are incorporated herein by reference in their entirety. [Background technology]

[0002] Intracranial aneurysms are among the most serious of medical conditions. Their typical size and location make them particularly difficult to detect and treat, but even small ones can cause debilitating physical and cognitive disabilities, coma, and death if ruptured. Early treatment methods involved clip ligation of the aneurysm neck in an open surgical procedure. More recently, minimally invasive endovascular techniques have been developed. Given the clinical significance of the condition and the difficulties encountered in addressing it, treatment for intracranial aneurysms has been a particularly active area for device and surgical development.

[0003] It should be noted that this background is not intended to aid in determining the scope of the claimed subject matter, nor is it to be construed as limiting the claimed subject matter to embodiments that solve any or all of the disadvantages or problems expressed above. Discussion of any technology, document, or reference in this Background section should not be construed as an admission that the content described is prior art to any of the subject matter claimed herein. Summary of the Invention

[0004] In one embodiment, a device is provided for temporarily protecting an aneurysmal neck of an intracranial vessel during treatment of the aneurysm. In this embodiment, the device comprises one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition in use from the contracted configuration to an expanded configuration that substantially conforms to a shape of an inner surface of the intracranial vessel proximate the aneurysm being treated, and the frame configured to transition back to the contracted configuration and removed from the intracranial vessel after the aneurysm has been treated. The device further comprises a cover disposed on at least a portion of the frame, the cover having at least a first portion configured to be positioned against the neck of the aneurysm while the aneurysm is being treated, the first portion of the cover having pores formed therein defining a first porosity thereof.

[0005] In another embodiment, a device is provided for temporarily protecting an aneurysmal neck of an intracranial vessel during treatment of the aneurysm. In this embodiment, the device comprises one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition in use from the contracted configuration to an expanded configuration that substantially conforms to the shape of the inner surface of the intracranial vessel near the aneurysm being treated, and after the aneurysm is treated, the frame is configured to transition back to the contracted configuration and removed from the intracranial vessel. In this embodiment, the device further comprises an electrospun covering disposed on at least a portion of the frame, the covering comprising at least a first portion configured to be positioned against the neck of the aneurysm while the aneurysm is being treated, the first portion of the covering having pores formed therein defining a first porosity thereof, the first porosity being 20% ​​or less, and the pore size associated with the first porosity being less than about 10 microns.

[0006] In another embodiment, a method of treating an intracranial aneurysm is provided, comprising the steps of passing a first microcatheter through an intracranial vessel and at least partially into the intracranial aneurysm, passing a guidewire through the intracranial vessel to a location outside the neck of the aneurysm while the first microcatheter is positioned within the intracranial vessel, passing a second microcatheter over the guidewire and through the intracranial vessel to a location outside the neck of the aneurysm, and passing a device for temporarily protecting the neck of the aneurysm in a deflated state through the second microcatheter and out from a distal end of the second microcatheter. The device for temporarily protecting the neck of the aneurysm comprises one or more wires forming a collapsible frame having at least a portion thereof a covering with pores defining a first porosity, and the method comprises the steps of expanding the device to a deployed configuration that substantially conforms to the shape of an inner surface of an intracranial vessel near the aneurysm with the covering defining the first porosity positioned relative to the neck of the aneurysm, placing at least one coil within the aneurysm through a first microcatheter, and removing the device from the intracranial vessel.

[0007] In another embodiment, an intravascular flow diverter for treating an aneurysm of an intracranial vessel comprises one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition in use from the contracted configuration to an expanded configuration that substantially conforms to a shape of an inner surface of the intracranial vessel proximate the aneurysm. The flow diverter further comprises an electrospun covering disposed on at least a portion of the frame. The covering comprises a first portion configured to be positioned against the neck of the aneurysm, the first portion of the covering having pores formed therein that define a first porosity of the first portion of the covering, and a second portion having a second porosity to blood flow that is greater than the first porosity, the second portion configured to be positioned adjacent to the aneurysm but not directly over the aneurysm.

[0008] In another embodiment, an intravascular flow diverter for treating an aneurysm of an intracranial vessel comprises one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition from the contracted configuration to an expanded configuration in use that substantially conforms to a shape of an inner surface of the intracranial vessel proximate the aneurysm. The flow diverter further comprises an electrospun covering disposed on at least a portion of the frame. The covering comprises a first portion configured to be positioned against a neck of the aneurysm, the first portion of the covering having pores formed therein that define a first porosity of the first portion, a second portion distal to the first portion having a second porosity to blood flow that is higher than the first porosity, the second portion configured to be positioned adjacent to the aneurysm but not directly over the aneurysm, and a third portion proximal to the first portion having a third porosity to blood flow that is higher than the first porosity, the third portion configured to be positioned adjacent to the aneurysm but not directly over the aneurysm. In this embodiment, each of the one or more wires has a diameter of less than 0.002 inches, the frame porosity over substantially the entire length of the frame is 93% or greater in an expanded frame configuration, the first porosity is less than 0.05, and the second porosity and third porosity are each greater than 0.05.

[0009] In another embodiment, a method of using an intravascular flow diverter to treat an aneurysm of an intracranial vessel comprises disposing the intravascular flow diverter within a microcatheter, threading the microcatheter through the intracranial vessel to the location of the aneurysm, and removing the intravascular flow diverter from the distal end of the microcatheter, in an aspect where an intravascular flow diverter stent comprising a plurality of wires coiled to form an expandable structure expands within the intracranial vessel sufficiently such that a first portion of an electrospun covering disposed over an outer surface of the stent is disposed directly against the neck of the aneurysm, the first portion having a first porosity to blood flow, and at least one second portion of the membrane is disposed adjacent to but not directly over the aneurysm, the at least one second portion having a second porosity to blood flow that is greater than the first porosity.

[0010] In another embodiment, an intrasaccular flow diverter for treating an aneurysm of an intracranial vessel comprises one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition from the contracted configuration to an expanded configuration that substantially conforms to a shape of an inner surface of an aneurysm sac during use. The intrasaccular flow diverter further comprises an electrospun covering disposed on at least a portion of the frame. The covering comprises a first portion configured to be positioned against the neck of the aneurysm, the first portion of the covering having pores formed therein that define a first porosity thereof, and a second portion having a second porosity to blood flow that is greater than the first porosity, the second portion configured to be positioned within the aneurysm sac distal to the neck of the aneurysm.

[0011] In another embodiment, a method of utilizing an intrasaccular flow diverter to treat an aneurysm of a blood vessel includes disposing the intrasaccular flow diverter within a microcatheter in a contracted state, threading the microcatheter through the blood vessel to a location within the aneurysm, and removing the intrasaccular flow diverter from a distal end of the microcatheter, such that a plurality of coiled wires forming a contracted generally spherical frame of the intrasaccular flow diverter are fully expanded within the aneurysm. In this embodiment, a first portion of a membrane disposed on at least a portion of an outer surface of the generally spherical frame is disposed directly against the neck of the aneurysm, the first portion having a first porosity to blood flow, and a second portion of the membrane is disposed within the aneurysm and distal to the neck of the aneurysm, the second portion having a second porosity to blood flow that is greater than the first porosity.

[0012] Various configurations of the subject technology have been shown and described by way of illustration, with the understanding that such configurations will be apparent to those skilled in the art from this disclosure. As will be recognized, the subject technology is capable of other different configurations, and its several details are capable of modification in various other respects, all without departing from the scope of the subject technology. Accordingly, the summary, drawings, and detailed description are to be regarded as illustrative in nature, and not as restrictive.

[0013] Various embodiments will now be described in detail with an emphasis on highlighting advantageous features in conjunction with the figures described below. These embodiments are for illustrative purposes only, and any scales that may be shown therein are not intended to limit the scope of the disclosed technology. These drawings include the following figures, in which like reference numerals indicate like parts: [Brief description of the drawings]

[0014] [Figure 1] Figure 1A shows blood flow near an aneurysm, and Figure 1B shows an aneurysm filled with coils. [Figure 2-1]Figure 2A shows balloon-assisted aneurysm coil embolization, and Figure 2B shows stent-assisted aneurysm coil embolization. [Figure 2-2] FIG. 2C shows a commercially available stent for stent-assisted aneurysm coil embolization. [Figure 3-1] 3A illustrates a portion of a blood vessel having an aneurysm, according to some embodiments, and FIG 3B illustrates a first microcatheter positioned within the blood vessel and the aneurysm, according to some embodiments. [Figure 3-2] Figure 3C illustrates a guidewire inserted into a blood vessel as shown in Figure 3B, according to some embodiments, and Figure 3D illustrates a second microcatheter positioned in a blood vessel guided by the guidewire of Figure 3C, according to some embodiments. [Figure 3-3] Figure 3E illustrates a second microcatheter as shown in Figure 3D with the guidewire removed, according to some embodiments. Figure 3F illustrates a temporary aneurysm neck protection device positioned within a vessel and against the neck of an aneurysm, according to some embodiments. [Figure 4-1] Figure 4A shows the temporary aneurysm neck protection device of Figure 3F. Figure 4B shows a modified structure of the temporary aneurysm neck protection device of Figure 3F, in which frame struts are connected at the distal and proximal ends of the frame. [Figure 4-2] Figure 4C shows a top view of an alternative embodiment of a temporary aneurysm neck protection device, and Figure 4D shows a side view of the embodiment of Figure 4C. [Diagram 5] 5A shows blood flow during stent-assisted coil embolization in some exemplary embodiments, and FIG 5B is a histogram of cover pore size in one embodiment of a temporary aneurysm neck protection device. [Figure 6] FIG. 6 illustrates side and cross-sectional views of a temporary aneurysm neck protection device in an expanded and contracted state according to some exemplary embodiments. [Figure 7] FIG. 7 illustrates side and cross-sectional views of another temporary aneurysm neck protection device in an expanded and contracted state according to some exemplary embodiments. [Figure 8]FIG. 8 illustrates a side view and a cross-sectional view of another temporary aneurysm neck protection device in an expanded and contracted state according to some exemplary embodiments. [Figure 9] FIG. 9 shows an exemplary wire stent framework design. [Figure 10-11] Figure 10 illustrates yet another temporary aneurysm neck protection device positioned within a blood vessel and against the neck of an aneurysm, according to some embodiments. Figure 11 illustrates a side view of at least a portion of the temporary aneurysm neck protection device of Figure 10, according to some exemplary embodiments. [Figure 12] FIG. 12 illustrates a flow chart of a method of using a temporary aneurysm neck protection device, according to some example embodiments. [Figure 13] FIG. 13 illustrates a flow chart for a method of manufacturing a temporary aneurysm neck protection device, according to some example embodiments. [Figure 14] Figure 14A shows a portion of a blood vessel having an aneurysm according to some embodiments, and Figure 14B shows an intravascular flow diverter positioned across the neck of the aneurysm. [Figure 15-16] Figure 15 shows a microcatheter placed in a blood vessel and near an aneurysm, according to some embodiments. Figure 16 shows an intravascular flow diverter placed in a blood vessel and directly against an aneurysm, according to some embodiments. [Figure 17] FIG. 17 illustrates an enlarged view of a portion of the intravascular flow diverter of FIG. 16 according to some exemplary embodiments. [Figure 18] Figure 18A illustrates a cross-section of a first embodiment of the intravascular flow diverter of Figure 16 according to some exemplary embodiments. Figure 18B illustrates a cross-section of a second embodiment of the intravascular flow diverter of Figure 16 according to some exemplary embodiments. Figure 18C illustrates a cross-section of a third embodiment of the intravascular flow diverter of Figure 16 according to some exemplary embodiments. [Figure 19-20]Figure 19 illustrates a flow chart for a method of using an intravascular flow diverter, according to some exemplary embodiments.Figure 20 illustrates a flow chart for a method of manufacturing an intravascular flow diverter, according to some exemplary embodiments. [Figure 21-1] FIG. 21A illustrates a portion of a blood vessel having an aneurysm according to some embodiments. [Figure 21-2] Figure 21B shows an intrasaccular flow diverter located inside the aneurysm. Figure 21C shows an embodiment of an intrasaccular flow diverter. [Figure 22-23] Figure 22 illustrates a microcatheter positioned within a blood vessel and within an aneurysm, according to some embodiments. Figure 23 illustrates an intrasaccular flow diverter positioned within an aneurysm within a blood vessel, according to some embodiments. [Figure 24-1] Figure 24A illustrates an embodiment of the intracapsular flow diverter of Figure 23 according to some exemplary embodiments. Figure 24B illustrates the intracapsular flow diverter of Figure 24A according to some exemplary embodiments, but from a different angle than that of Figure 24A. [Figure 24-2] Figure 24C illustrates yet another embodiment of the intracapsular flow diverter of Figure 23, according to some exemplary embodiments. Figure 24D illustrates yet another embodiment of the intracapsular flow diverter of Figure 23, according to some exemplary embodiments. [Diagram 25] FIG 25A illustrates a cross section of a collapsed embodiment of the intra-sac flow diverter of FIG 23 according to some exemplary embodiments. FIG 25B illustrates a cross section of another collapsed embodiment of the intra-sac flow diverter of FIG 23 according to some exemplary embodiments. FIG 25C illustrates a cross section of yet another collapsed embodiment of the intra-sac flow diverter of FIG 23 according to some exemplary embodiments. FIG 25D illustrates a cross section of yet another collapsed embodiment of the intra-sac flow diverter of FIG 23 according to some exemplary embodiments. [Figure 26] FIG. 26 illustrates a flow chart for a method of using an intracapsular flow diverter, according to some example embodiments. [Figure 27] FIG. 27 illustrates a flow chart for a method of manufacturing an intrasaccular flow diverter, according to some example embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The following description and examples set forth in detail some exemplary embodiments, implementations and configurations of the invention of the present disclosure. Those skilled in the art will recognize that there are numerous variations and modifications of the invention that fall within its scope. Thus, the description of a particular exemplary embodiment should not be deemed to limit the scope of the invention.

[0016] definition Collapsed Configuration: The device is in the collapsed configuration when it is sheathed near and within the distal end of a catheter ready for use in an intravascular procedure.

[0017] Expanded Configuration: The device is in the expanded configuration when it is unsheathed outside of the vasculature such that the outward expansion of the side walls is not constrained by any surrounding walls. For flow diverters that are manually expanded by a surgeon, the expanded configuration is achieved when the flow diverter is manually expanded to its maximum target diameter for its normal use.

[0018] Deployment Configuration: A device is in the deployed configuration when it is unsheathed and its sidewalls are in contact with the inner wall of a vessel. The deployed configuration may have a smaller diameter relative to the sidewall than the expanded configuration depending on the size of the vessel in which the device is deployed. A device in the deployed configuration is usually close to, but not completely in, the expanded configuration.

[0019] Frame: One or more struts forming a structural scaffolding that defines the device sidewalls configured to conform to the inner surface of the vascular section when the device is in a deployed configuration. A metal wire configuration is a common example of struts for a frame.

[0020] Frame Porosity: The fractional open area of ​​a selected portion of a sidewall defined by the struts of a device when the device is in an expanded configuration. Frame porosity may vary in different portions of a sidewall. Thus, for a given selected portion of a frame sidewall, the frame porosity is the total area of ​​the selected portion of the sidewall minus the area of ​​the struts that define the selected portion of the sidewall divided by the total area of ​​the selected portion of the sidewall when the device is in an expanded configuration.

[0021] Cover: A film or membrane that connects two or more posts of a frame and extends over some or all of the open area of ​​a sidewall defined by the posts of the frame.

[0022] Cover Porosity: The fractional open pore area of ​​a selected portion of the cover membrane when the device is in an expanded configuration. Cover porosity may vary in different portions of the sidewall that are covered by the membrane.

[0023] Pore ​​Size: The size of a given pore is defined as the diameter of the inscribed circle that touches the actual boundary of the given pore in three points.

[0024] Cover Porosity Distribution: Cover porosity in a selected area of ​​a cover may be distributed among a group of pores having a particular pore characteristic, usually a size characteristic. For example, a 30% porosity cover has a certain portion of its porosity contributed by pores of a defined size range. Cover porosity distribution refers to the characterization of the amount of total porosity distributed by pores of a defined set of one or more characteristics.

[0025] Covering Permeability: Covering permeability is a qualitative or quantitative measurement of the ability of various materials to pass through the covering when the device is in normal use in a blood vessel. Covering permeability is affected by several different aspects of the covering, including cover porosity and porosity distribution for various sizes of blood components and / or blood particles, and the chemical properties of the covering material for the chemical properties of the various blood components and / or blood particles. Covering permeability to various blood components may also be affected by local flow and pressure conditions at the implantation site in the blood vessel. The characteristics of fluid flow that occur during use of the devices described herein when porosity and permeability are the relevant device properties will be clear from the context, and typically involve blood flow through an intracranial blood vessel opening and / or an intracranial aneurysm neck that is not occluded except when the device is applied over or across it.

[0026] Electrospinning: A technique for depositing fibrous layers onto a target surface. Electrospinning involves discharging a jet of polymer solution from an outlet orifice in a reservoir onto a target surface under the influence of an electric field. By moving the outlet orifice and / or the target surface during the electrospinning process, polymer fibers and fibrous polymer layers and mats with various properties can be produced. Fibers or fibrous polymer layers or mats so deposited are referred to herein as "electrospun." Various electrospinning techniques and materials suitable for electrospinning are described in U.S. Patent Application Publication No. 2018 / 0161185 to Kresslein et al. at paragraphs

[0061] -

[0077] , which are incorporated herein by reference.

[0027] SUMMARY OF THE DISCLOSURE The present disclosure relates to apparatus and methods for the treatment of intracranial aneurysms.Several exemplary embodiments that overcome the limitations of current devices are described herein in connection with one or more of the drawings.

[0028] Stent-assisted aneurysm coil embolization 1A shows blood flow through a blood vessel 110 in the region surrounding an aneurysm 120. In many cases, particularly for wider-necked aneurysms, a portion of the blood vessel flow 150 passing through the aneurysm neck is diverted into the aneurysm as aneurysm inflow 155 and circulates backwards before re-entering the blood vessel flow 150 as aneurysm outflow 165. This intrasaccular circulation presses outward against the walls of the aneurysm, causing it to expand and potentially rupture.

[0029] Endovascular coil embolization is the treatment of choice for most aneurysms in many centers. This is shown in FIG. 1B. In this treatment protocol, one or more wire coils 230 are placed inside the aneurysm to partially or completely fill the sac. When the aneurysm is filled in this manner with coils, blood flow 150 is largely diverted into the aneurysm sac, reducing internal pressure and also aiding in aneurysm embolization by retaining red blood cells inside the aneurysm. Interventional neuroradiologists have developed several important adjuncts to aid in the treatment of these intracranial aneurysms, such as balloon and stent assisted coil embolization of wide-necked aneurysms. These techniques have made it possible to treat many aneurysms that previously required more invasive open neurosurgical clipping procedures.

[0030] Figure 2A shows a portion of a blood vessel 110 having an aneurysm 120, shown as a bulge in the vessel wall, in a portion of the vessel 110. The aneurysm 120 in Figure 2A has been treated by balloon-assisted coil embolization. A balloon 250 is used to confine the coil 230 as it is deployed within the aneurysm sac.

[0031] A potential problem with the balloon-assisted coil embolization technique is that the introduction of an occlusion balloon increases the rate of thrombus formation and thromboembolic events. Moreover, the presence of such a balloon in the parent vessel may theoretically promote blood stasis, leading to thrombus formation or platelet aggregation. Furthermore, because the neurovasculature distal to the aneurysm being treated has a constant requirement for blood, the occlusion balloon must be deflated intermittently during the procedure to control the restriction of blood flow to such distal neurovasculature, as well as to control blood flow into and out of the aneurysm.

[0032] FIG. 2B illustrates stent-assisted embolization. For this procedure, an intravascular stent or flow diverter 270 previously used as a permanent implant has been modified and repurposed for temporary coil embolization support. However, these devices are relatively unsuitable for protecting the aneurysm neck from outflow flow once expanded across the neck of the aneurysm due to the high frame porosity of the conventional intravascular stent. For example, the Comaneci Aneurysm Neck Protection Device (290 shown in FIG. 2C) by Rapid Medical is an expandable braid that opens up to protect the neck and allows coil embolization to proceed while "jailing" the coils within the aneurysm during the procedure. The open structure of the Comaneci device is useful for retaining the coils, but does not prevent migration of embolic debris from the aneurysm and potentially into the parent artery through the braid. Similarly, the exposed metal in such devices is a known thrombogenic surface that allows blood clots to form on the exposed wires or in the gaps between the wires relative to the braid.

[0033] For these reasons and others, there is a need for improved temporary aneurysm neck protection devices and associated methods of using and / or manufacturing the same. Accordingly, in some embodiments described herein, a device is provided for temporarily protecting the neck of an aneurysm of a blood vessel. The device may include one or more struts forming a frame configured to expand and substantially conform to the shape of the inner surface of the blood vessel while the aneurysm is being treated. The frame may define a frame porosity. The device may include a retention wire disposed at a proximal end of a multi-wire frame for unsheathing and resheathing the device before and after an aneurysm coiling procedure is performed. The device may include a cover adhered or deposited over a portion or all of the frame. The cover may include at least a first portion configured to be placed directly against the neck of the aneurysm while the aneurysm is being treated. The first portion may define a cover porosity, porosity distribution, and permeability while the aneurysm is being treated. Common locations for intracranial aneurysms include the communicating arteries, the internal carotid arteries, and the middle cerebral arteries. The devices described herein may be usable within these arteries, for example.

[0034] In some other embodiments, a method is provided that utilizes a device for temporarily protecting an aneurysmal neck of a blood vessel. The method may include threading a first catheter through the blood vessel and at least partially into the aneurysm. The method may include threading a guidewire through the blood vessel to a location outside the neck of the aneurysm while the first catheter is positioned within the blood vessel, and threading a second microcatheter over the guidewire and through the blood vessel to a location outside the neck of the aneurysm. The method may further include threading a device for temporarily protecting an aneurysmal neck constructed according to the principles and embodiments described herein through the second microcatheter in a contracted state and outward from a distal end of the second microcatheter such that a plurality of struts forming a contractible frame expand to substantially conform to the shape of the inner surface of the blood vessel. A retaining wire disposed at a proximal end of the frame of the plurality of wires may extend through the second catheter. At least a first portion of a cover covering all or a portion of the frame may be positioned directly against the neck of the aneurysm. The first portion during which the aneurysm is being treated may define the covering porosity, porosity distribution and permeability.

[0035] In some other embodiments, a method of manufacturing a device for temporarily protecting an aneurysmal neck of a blood vessel is provided. The method may include forming a collapsible frame configured to expand to substantially conform to a shape of an inner surface of the blood vessel. The method may include disposing a retention wire at a proximal end of a multi-wire frame. The method may include disposing a cover over a portion or all of a length of the frame. The cover may be configured to be placed directly against the aneurysm neck during an aneurysm treatment procedure, such as coil embolization.

[0036] Some described embodiments of temporary aneurysm neck protection devices, which may be angiographically visible for precise placement, may be suitable for use in neurovascular aneurysm embolization cases, soft dilation procedures (e.g., releasing other neurovascular devices against the vessel wall), potential vasospasm cases, and potential vascular stenosis cases, among other suitable applications.

[0037] Some embodiments described herein may have similar advantages as balloon-assisted aneurysm coil embolization, but without the risk of occlusion of the parent artery or blocking of blood flow to the distal neurovasculature upon expansion and / or inflation of the temporary aneurysm neck protection device. This may advantageously reduce time constraints on the clinician and reduce the risk of parent artery thrombosis. Some embodiments as described herein may have similar advantages as stent-assisted aneurysm coil embolization, but without the risk of embolic debris generation and release into the parent artery associated with performing a coil embolization procedure.

[0038] 3A-3F illustrate one embodiment of performing a stent-assisted aneurysm coil embolization procedure. As shown in FIG. 3A, a first catheter 200 may be threaded through blood vessel 110 and at least partially into aneurysm 120. The first catheter 200 will be utilized to deploy a coil within aneurysm 120 in a later step. As shown in FIG. 3B, a guidewire 300 may be threaded through blood vessel 110 to a location outside the neck of aneurysm 120. As shown in FIG. 3C, a second catheter 400 may be threaded through blood vessel 100, guided over guidewire 300, to a location outside the neck of aneurysm 120. As shown in FIG. 3D, guidewire 300 may be retracted or removed through second catheter 400. In some embodiments, the use of guidewire 300 may be optional. 3F, a temporary aneurysm neck protection device 600 may be deployed out from the distal end of the second catheter 400 over the neck of the aneurysm and a portion of the first catheter. The device 600 may self-expand under bias from a frame 610 or may be manually expanded under the control of a surgeon.

[0039] The stent 600 of Figure 3F differs from conventional stents used in stent-assisted coil embolization in that the frame of the stent includes a covering 610, which may include a polymeric material extending between some or all of the struts of the frame. This stent embodiment is further shown in Figure 4A.

[0040] Referring now to Figure 4A, a first embodiment of a temporary aneurysm neck protection device 600 is shown in an expanded state. The device 600 comprises a frame defined by struts 640. Figure 4B is a modified version of the device 600 in which the struts 640 of the frame are interconnected at the distal end as well as the proximal end of the stent. A retention wire 630 is coupled to the frame at the proximal end of the frame. The frame has a total stent length L between its proximal and distal ends in a substantially expanded state. 1 The cover 610 may define a predetermined length L of the frame of the wire 640 in this embodiment, on a part or all of the frame. 2 (e.g., along a portion) of the frame sidewall. In some embodiments, at least the portion of the frame of wires 640 on which the membrane 610 is disposed may have a generally cylindrical sidewall. In some embodiments, the distal end 850 of the frame of wires 640 may not be shielded by any of the struts 640. The porosity and permeability of the covering 610 may be particularly suitable for stent-supported coil embolization procedures. The electrospinning process described above has been found to be advantageous in controlling the porosity and permeability of the covering membrane to achieve various clinical and surgical functions.

[0041] 4C and 4D show another embodiment of a temporary aneurysm neck protection device, with FIG. 4C being a top view and FIG. 4D being a side view. In this embodiment, the distal end 674 is not shielded by any struts, similar to the embodiment of FIG. 4A. At the proximal end 672, the retention wire 630 is attached to the proximal end at only one point, again leaving little or no shielding of the opening at the proximal end 672. This maximizes blood flow through the device during the coil embolization procedure. Also, the peripheral opening at the proximal end 672 may be beveled or chamfered from where the retention wire 630 is attached to the strut of the protection device toward the distal end. This can increase blood flow through the device and aid in re-sheathing the device inside an introducer catheter for removal after the coil embolization procedure. The distal end may be heat set to bias the wire against the vessel wall.

[0042] 5A, a temporary aneurysm protection stent 600 is shown placed across the neck of an aneurysm 120 to support an aneurysm coil embolization procedure. A cover 610 is provided over the struts 640 that form the frame of the stent. The cover 610 has porosity, porosity distribution, and permeability characteristics that substantially block the circulating aneurysm inflow 155 and outflow 165 flows shown in FIG. 1A. This inflow 155 and outflow blocking function can be provided by a membrane with surprisingly high porosity and large pore size. In general, the porosity and pore size can be appropriately balanced to produce a membrane with low permeability to the inflow 155 and outflow 165 flows in the presence of vascular flow 150. A higher total porosity requires a smaller pore size, and a lower porosity will have a larger pore size while still maintaining the desired inhibition of the inflow 155 and outflow 165 flows. This can be evaluated in a more quantitative manner by considering the product of the median pore size and the total cover fractional porosity as a characterization of the cover porosity distribution. For advantageous coil embolization support cover membranes, this product may be in the range of 0.1 to 50, with 5 to 20 being found to be particularly suitable, with the pore size units being microns. For example, a suitable membrane may have a total porosity of 0.05 to 0.5 and a median pore size of 10 to 100 microns. In one embodiment, a membrane with a porosity of 0.3 to 0.6 and a median pore size of 20 to 30 microns is utilized. In another embodiment, a membrane with a total porosity of 0.05 to 0.15 and a median pore size of 30 to 100 microns is utilized. In another embodiment, a membrane with a total porosity of 0.15 to 0.25 and a median pore size of 20 to 80 microns is utilized. In any of the embodiments described herein, the pore size range can be 5 to 400 microns, 5 to 200 microns, or 5 to 100 microns. Outliers outside these ranges that do not contribute significantly to the total porosity of the cover (e.g., less than 5% of the total porosity) are ignored.

[0043] A relatively high porosity membrane that retains the ability to block large amounts of aneurysm inflow 155 and outflow 165 has a number of beneficial effects. As the coil 230 is deployed to displace the original contents of the aneurysm, blood components such as plasma and red blood cells can still migrate out of the aneurysm sac generally perpendicular to the covering membrane plane (as shown at 175 in FIG. 5A). Furthermore, the lower pressure drop from the blood vessel to the aneurysm's internal volume across the more porous covering membrane allows blood pressure to keep the aneurysm sac in an expanded state while the coil embolization procedure is being performed. Additionally, as will be further described below, a higher porosity membrane allows the use of a very high porosity wire stent frame by providing structural support to the stent, thereby allowing the manufacture of a highly flexible stent that is more easily navigated through complex vasculature to the aneurysm.

[0044] It is also desirable to allow the major blood components of plasma and red blood cells to migrate out of the aneurysm sac, similar to uncovered stents currently used to assist with coil embolization, while retaining any embolic debris generated during the coil embolization procedure inside the aneurysm. Electrospun stent cover membranes having suitable porosity and permeability to achieve this are described in paragraphs

[0092] to

[0103] of U.S. Patent Application Publication No. 2021 / 0052360. In this embodiment, as the coil is deployed within the aneurysm sac, blood components displaced by the coil may migrate out as described above, but embolic debris may be substantially retained within the sac.

[0045] A cover membrane 610 having any of the above considered porosity and permeability characteristics may also aid in redirecting the coil away from the neck to effectively fill the aneurysm 120, since it eliminates the risk of a coil structure being built up that protrudes and becomes entangled within the frame, as is known to occur with the use of the open blade Comaneci device described above.

[0046] In some embodiments, it may be desirable to associate the cover membrane porosity almost exclusively with small pores and relatively low total porosity (e.g., median pore size of 10 microns or less and fractional porosity of 0.2 or less) so that the membrane remains more permeable to plasma than to red blood cells (preferably substantially more permeable, e.g., at least 10% more permeable, or preferably at least 50% more permeable). In some embodiments, the cover membrane may be substantially impermeable to the movement of red blood cells out of the aneurysm sac, but substantially permeable to the movement of plasma out of the aneurysm sac. This is because when the embolic coil is placed, the cover membrane retains free red blood cells with the coil in addition to any embolic debris, still allowing the aneurysm sac to move fluids, potentially enhancing the embolization process driven by the coil. Another advantage of the small pore size is that radiocontrast agents may flow through the device without entering the aneurysm sac during the procedure. This allows for fluoroscopic visualization of the coils flowing into the aneurysm sac during the procedure without interference from contrast that may be noticeable in the vasculature. FIG. 5B is a histogram of one embodiment of a pore size distribution in a portion of a suitable covering for some device embodiments. In this covering, the median pore size is 5-6 microns. In this embodiment, the total porosity was about 0.025. For these small pore low porosity embodiments, particularly suitable coverings may be characterized by the median pore size multiplied by the partial porosity of the covering of 0.1-2.

[0047] These smaller pore sizes can be achieved, for example, by depositing a relatively thick multi-layer mat of electrospun fibers onto a shrinkable frame, such that any large pores are essentially unable to extend across the thickness of the cover.

[0048] In some embodiments, a surgical kit may be provided for support of an aneurysm sac coil embolization procedure, the kit including a variety of stents with different porosity and permeability characteristics to allow the surgeon to select the appropriate covering membrane properties for a given procedure based on the surgeon's preferences, experience, and the physiological characteristics of the particular aneurysm being treated.

[0049] As shown in Figures 6-8, the temporary aneurysm neck protection device 600 may comprise a frame comprising struts 640 constructed from a number of wires braided or coiled together. In some such embodiments, each of the wires will ultimately extend to its entire length L in the expanded configuration. 1 and diameter D 1 The coil may be coiled in a contractible and later re-expandable substantially helical shape or configuration configured to provide a frame of (e.g., about 0.12 inches, or 3 mm, for intracranial applications, although any other suitable maximum diameter is contemplated).

[0050] In some such embodiments, each wire is spaced apart at a predetermined interval L 4 In some embodiments, each of the wires is offset from an adjacent wire by a predetermined pitch L 3 (i.e., each loop or winding of a particular one of the wires may have a predetermined length L along the length of extension of the temporary aneurysm neck protection device 600. 3 In some such embodiments, the distance L 4 is the division pitch L of the wires wound in the same direction. 3 The above-described geometry of the wire advantageously provides for easy unhindered expansion and contraction of the temporary aneurysm neck protection device 600 in vivo.

[0051] In some embodiments, the wire 640 is made of superelastic Nitinol. In some other embodiments, Cobalt Chromium may be used. In still other embodiments, Nitinol shape memory alloy may be used. However, the disclosure is not so limited and the wire may be made of any suitably flexible, expandable and compressible material, including a polymer, which may itself be an electrospun polymer fiber.

[0052] In some other embodiments, a laser cut nitinol tube can be constructed, then expanded, and then heat set, and the resulting nitinol tube can be superelastic in nature, allowing for subsequent contraction for introduction into the vasculature and re-expansion during later deployment.

[0053] In some embodiments, each of the wires or the Nitinol tubes described above may be coated with a resilient polymer 1210 configured to eliminate or substantially reduce the exposed metal surface of the wires, thereby minimizing the thrombogenicity of the frame. The coated wires may then be covered by a membrane 610 having the desired porosity and permeability as described above.

[0054] In addition to providing the selective filtering functions described above, the membrane 610 may provide support for the underlying extension frame of struts 640 while also having a very thin construction. Such a supporting cover membrane 610 allows for a reduction in the number of wires 640 required for construction and effective operation (e.g., six or fewer wires as shown in Figures 6-8, or even a single wire) compared to conventional devices without such a membrane. The cover membrane allows for increased frame porosity while still providing all the desired filtering functions of the membrane 610. In some embodiments, the frame porosity over the majority of its length is greater than 90%, and more preferably greater than 95%.

[0055] This reduction in strut area (increased frame porosity) also advantageously reduces the device mass per unit length, the delivery profile as it navigates the aneurysm 120 in the delivery system, the longitudinal stiffness of the device 600, and the radial forces it exerts. All of these improvements, individually and collectively, allow for easier tracking within the vasculature and improved delivery and deployment of the device 600, 700. This is particularly true and advantageous for smaller and / or tortuous vessel applications, such as those of the brain, where the ratio of retracted radius to properly deployed radius of the device 600, 700 can be much smaller than in larger vessel applications such as the aorta.

[0056] In some embodiments, the primary or only function of the covering membrane 610 is frame support, rather than filtering. In these embodiments, the frame porosity is very high and the covering membrane porosity is also very high and may be dominated by large pores that perform substantially no filtering function for any blood components, embolic debris, etc. These embodiments may still be an improvement over existing coil embolization assisted stents, as they may be particularly flexible in the contracted configuration, thus making it easier for the vascular surgeon to reach the aneurysm to be treated through the tortuous intracranial vasculature.

[0057] In one embodiment, the frame porosity is greater than 90% and the frame is covered over at least the area of ​​its length intended to bridge the aneurysm neck with an electrospun polymer membrane that is substantially permeable to the movement of plasma and red blood cells from the aneurysm sac to the exterior during coil embolization and substantially impermeable to blood flow past the aneurysm neck during normal circulation.

[0058] In another embodiment, the frame porosity is greater than 93% and the frame is covered over at least the area of ​​its length intended to bridge the aneurysm neck with an electrospun polymer membrane that is substantially permeable to the movement of plasma and red blood cells out of the aneurysm sac during coil embolization and substantially impermeable to blood flow past the aneurysm neck during normal circulation.

[0059] In other embodiments, the frame porosity is greater than 93% and the expanded configuration has a sidewall maximum diameter of less than 10 mm. The frame is covered by an electrospun membrane over at least a portion of its length with a pore size distribution. The pore size distribution includes a first set of pores with a maximum dimension of about 25 microns or less and a second set of pores with a maximum dimension of about 50 microns or more. The prevalence of pores in the first set is at least three times the prevalence of pores in the second set. In this embodiment, the cover porosity can be about 30% or more.

[0060] Another advantage of the membrane 610 applied to the frame of the wire 640 is that the porosity and therefore flow control provided by the membrane 610 allows smaller devices 600 to be made available and / or used compared to existing devices, all of which have a very narrow range of vessel diameters in which each size is effective in satisfactorily manipulating blood flow. For example, while traditional wire braids are typically provided in 0.25 mm increments, in at least some embodiments, the temporary aneurysm neck protection devices 600, 700 may be available in much larger increments of size, e.g., 1.0-1.5 mm, allowing the device 600 to be included in a surgical kit for treating an aneurysm by a factor of 4-6.

[0061] It is also contemplated that the wires may have a variety of different thicknesses depending on the requirements of the desired application. Figures 6-8 show various exemplary side and cross-sectional views of exemplary temporary aneurysm neck protection device embodiments. The embodiments of Figures 6-8 each have a different diameter D 2 , D5 , D 8 6A and 6B are substantially similar to each other, except that they utilize wires 640 having a respective minimum contracted diameter for each of the two exemplary configurations for wire orientation when the frame is in a substantially contracted state.

[0062] The first exemplary orientation of wires in each of Figures 6-8 shown in respective cross sections 1250, 1350, 1450 comprises an innermost subset of six wires and an outermost subset of six wires. Each of the innermost threads is disposed in direct contact with two adjacent threads of the innermost subset and one thread of the outermost subset. The center of each of the outermost threads is radially collinear with both the center of the cross section of the frame and the center of the corresponding inner thread with which it is in direct contact.

[0063] A second exemplary orientation of the wire is shown at cross-section 1280, 1380, 1480 in each of Figures 6-8 and comprises the same innermost subset of six threads and outermost subset of six threads, except that each of the innermost threads is disposed in direct contact with each of two adjacent threads of the innermost subset and each of two adjacent threads of the outermost subset. In this second exemplary orientation, the center of each of the outermost threads is offset evenly but oppositely from the center of each of the adjacent inner threads with which it directly contacts. This second exemplary orientation is more densely packed than the first exemplary orientation (e.g., the centers of each immediately adjacent pair of innermost threads and the center of the shared immediately adjacent outermost thread form the vertices of an equilateral triangle), thus providing the smallest possible minimum contraction diameter between the two exemplary orientations.

[0064] In FIG. 6, the wire is shown as having an outer diameter of about 0.001 inches, and thus has a maximum expanded diameter D 1 and minimum shrinkage diameter D 3 (e.g., 0.005 inches) and a maximum expanded diameter D 1 and minimum shrinkage diameter D 4(e.g., 0.004 inches).

[0065] In FIG. 7, the wire is shown as having an outer diameter of about 0.002 inches, and thus has a maximum expanded diameter D 1 and minimum shrinkage diameter D 6 (e.g., 0.010 inches) and a maximum expanded diameter D 1 and minimum shrinkage diameter D 7 (e.g., 0.009 inches).

[0066] In FIG. 8, the wire is shown as having an outer diameter of about 0.003 inches, and thus has a maximum expanded diameter D 1 and minimum shrinkage diameter D 9 (e.g., 0.015 inches) and a maximum expanded diameter D 1 and minimum shrinkage diameter D 10 (e.g., 0.013 inches).

[0067] The specific embodiments described with reference to Figures 6, 7 and 8 should not be construed as limiting the frame configurations that can be used with the inventive stent embodiments described herein. Figure 9 shows exemplary stent frame configurations of currently available commercial stents. As can be seen, a wide variety of frame strut configurations, strut connection techniques, coiling and braiding designs have been developed, with many more still being developed. Any of these may be used in accordance with the inventive principles described herein to generate new and improved stents for aneurysm coil embolization support applications.

[0068] In some embodiments, the cover membrane 610 may be provided on only a portion of the deployed functional portion of the frame, or may be configured to cover different portions of the sidewall and have one or more of variable porosity, variable porosity distribution and / or variable permeability along its length. Embodiments having such configurations are shown in Figures 10 and 11. In these embodiments, the device 700 comprises a substantially cylindrical frame wire and retention wire 630 that allows blood flow through substantially open proximal and distal ends.

[0069] The membrane 610 is disposed on at least a portion of the frame, and the wire 640 is spaced apart from the frame by a predetermined length L 2 (e.g., a portion) around substantially the entire circumference. However, in the embodiment of Figs. 10 and 11, the cover 610 has a first portion 710 extending along a first portion of the length of the frame and having a first porosity and permeability characteristic, and a second portion 720 extending along a second portion of the length of the frame and having a second porosity and / or permeability characteristic, where one or both of the second porosity and permeability may be different from the first. In some embodiments where the stent is suitable for aneurysm coil embolization support, the cover membrane portion 720 has porosity and permeability characteristics as described above, and the cover membrane portion 710 may be essentially liquid-tight (e.g., less than 5% cover porosity). This can be achieved, for example, by depositing a relatively thick multi-layer mat of electrospun fibers onto the stent frame such that essentially no pores are able to extend through the thickness of the cover. According to this design, if the aneurysm 120 ruptures during a coil embolization procedure, without the need to remove the temporary aneurysm neck protection device 700 or insert another device, the retention wire 630 can be pulled and ultimately the temporary aneurysm neck protection device 700 moved relative to the blood vessel 100 until the distal first portion 710 of the membrane 610 is now positioned over the neck of the aneurysm 120, thereby advantageously preventing the unwanted passage of emboli or blood clots into the parent vessel 100 and preventing blood flow into the ruptured aneurysm.

[0070] This disclosure now refers to Figure 12, which shows a flow chart for an exemplary method of utilizing a device for temporary protection of an aneurysmal neck of a blood vessel, as described elsewhere in this disclosure.

[0071] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0072] Step 1502 includes threading a first microcatheter through a blood vessel and at least partially into the aneurysm. For example, as previously described, a first microcatheter 200 may be threaded through a blood vessel 100 and at least partially into the aneurysm 120.

[0073] Step 1504 includes threading a guidewire through the blood vessel to a location outside the neck of the aneurysm while the first microcatheter is positioned within the blood vessel. For example, as previously described, the guidewire 300 can be threaded through the blood vessel 100 to a location outside the neck of the aneurysm 120 while the first microcatheter 200 is positioned within the blood vessel 100.

[0074] Step 1506 includes threading a second microcatheter over the guidewire and through the blood vessel to a location outside the neck of the aneurysm. For example, as described above, the second microcatheter 400 can be threaded over the guidewire 300 and through the blood vessel 100 to a location outside the neck of the aneurysm 120.

[0075] Once the second microcatheter 400 is so positioned, the guidewire 300 may be removed from the second microcatheter 200 and the blood vessel 100. In embodiments in which a guidewire 300 is not utilized, step 1504 may be omitted and step 1506 may comprise threading the second microcatheter 400 through the blood vessel 100 to a location outside the neck of the aneurysm 120 without guidewire guidance.

[0076] Step 1508 includes threading a device for temporarily protecting the neck of the aneurysm in a contracted state through the second microcatheter and out of the distal end of the second microcatheter. The device comprises one or more wires forming a contractible frame having at least a portion thereof a covering with pores defining a first porosity. In step 1510, the device is expanded to a deployed configuration that substantially conforms to the shape of the inner surface of the blood vessel near the aneurysm with the covering positioned against the neck of the aneurysm.

[0077] For example, as previously described, the device 600, 700 for temporarily protecting the neck of the aneurysm 120 may be threaded in a contracted state through the second microcatheter 400 from the distal end of the second microcatheter 400 to the outside in the following manner, in which the wire 640 coiled to form a contractible frame expands to substantially conform to the shape of the inner surface of the blood vessel 100, and the retaining wire 630 disposed at the proximal end of the frame of the wire 640 extends through the entire length of the second catheter 400 and retains the predetermined length L of the frame. 2 At least a first portion of the membrane 610 having a first porosity relative to blood flow disposed substantially around the entire circumference of the aneurysm 120 is positioned directly against the neck of the aneurysm 120 .

[0078] In some embodiments, the method according to this flowchart may include an optional step including utilizing membrane 610 to retain an intra-aneurysmal clot within aneurysm 120, thereby preventing migration of the clot into blood vessel 100 while aneurysm 120 is being treated.

[0079] In some embodiments, the method according to this flowchart may include step 1512, which includes placing at least one coil through the first microcatheter 200 within the aneurysm 120 with the frame of the device 600, 700 substantially conforming to the shape of the inner surface of the blood vessel 110 and redirecting the at least one coil away from the neck of the aneurysm 120, thereby facilitating effective filling of the aneurysm 120 with the coils. In step 1514, the device may be removed from the blood vessel.

[0080] In some embodiments, the method according to this flowchart may include an optional step including utilizing a membrane 610 to prevent at least one coil from protruding into and / or becoming entangled in the wires 640 of the frame.

[0081] In some embodiments, the method according to this flowchart may include an optional step including allowing blood to flow freely longitudinally through the frame while the frame is expanded to supply blood directly to tissue distal to the aneurysm.

[0082] In some embodiments, each of the wires 640 converge and meet at the distal end 650 of the frame. In some embodiments, none of the wires 640 meet at the distal end 850 of the frame, thereby providing an unobstructed distal end 850 of the frame. In some embodiments, each of the wires 640 terminates at the distal end 850 of the frame and is doubled over or merged into a generally circular structure.

[0083] In some embodiments, the frame is configured to stretch as it contracts, thereby minimizing the contracted diameter of the device 600, 700. In some embodiments, the frame is configured to extend beyond a predetermined length L over which at least the membrane 610 is disposed. 2 In some embodiments, the collapsible frame includes wires 640 each wound in a generally helical shape, each wire 640 including a plurality of helical loops, each having a predetermined pitch L3 In some embodiments, each wire 640 has a predetermined spacing L 4 640. In some embodiments, there are six wires 640. In some embodiments, the frame is configured to self-expand under bias from the wires 640.

[0084] In some embodiments, in the contracted state, the device 600, 700 is configured to be disposed within a microcatheter 400 that is configured to be threaded through the blood vessel 100 to a location immediately adjacent the neck of the aneurysm 120. In some embodiments, the device 600, 700 is configured to be threaded while the microcatheter 200 is disposed within the blood vessel 100 with at least a distal tip disposed within the aneurysm sac 120.

[0085] In some embodiments, the first porosity is in the range of about 0-0.1 and the pore size associated with the first porosity is less than about 20 microns, and the device 600, 700 is configured to support hemostasis within the aneurysm 120 by substantially blocking blood flow into the aneurysm 120 through the first portion 610, 710 of the membrane 610. In some embodiments, the first porosity is in the range of about 0.1-0.4 and the pore size associated with the second porosity is greater than about 100 or 200 microns, and the device 600, 700 is configured to allow substantially free flow of fluid through the first portion 610 of the membrane 610 in the following manner: As intrasac volume is displaced by a coil introduced into the aneurysm sac 120, fluid flows freely out of the aneurysm 120 through the first portion 710 of the membrane 610, and the coil is introduced into the aneurysm 120 while systemic blood pressure maintains the aneurysm 120 in an expanded state.

[0086] In some embodiments, membrane 610 is configured to retain any intraaneurysmal blood clots within aneurysm 120, thereby preventing migration of the blood clots into blood vessel 100 while aneurysm 120 is being treated. In some embodiments, membrane 610 is configured to redirect coils introduced into aneurysm 120 away from the neck of aneurysm 120, thereby facilitating effective filling of aneurysm 120 with the coils. In some embodiments, membrane 610 is configured to prevent coils introduced into aneurysm 120 from protruding into and / or becoming entangled in wires 640 of the frame.

[0087] In some embodiments, each end (e.g., proximal and distal) of the frame is substantially open in a manner such that the frame is configured to allow blood to flow freely longitudinally therethrough while the frame is expanded to supply tissue directly distal to the aneurysm.

[0088] In some embodiments, the wires 640 form the innermost wires of a first subset and the outermost wires of a second subset when the frame is contracted. In some embodiments, each of the innermost wires is placed in direct contact with each of two adjacent innermost wires and one of the outermost wires, and the center of each of the outermost wires is collinear with the center of the cross-section of the contracted frame and the center of the corresponding innermost wire with which the outermost wire is in direct contact. In some embodiments, each of the innermost wires is placed in direct contact with each of two adjacent innermost wires and each of two adjacent outermost wires, and the center of each of the outermost wires is offset evenly but oppositely from the center of each of the adjacent inner wires with which the outermost wire is in direct contact.

[0089] In some embodiments, each of the wires 640 has a diameter of about one of 0.001 inches, about 0.002 inches, and about 0.003 inches. In some embodiments, the device 600, 700 is configured to have a minimum outer diameter of about one of about 0.004 inches, about 0.005 inches, about 0.009 inches, about 0.010 inches, about 0.013 inches, and about 0.015 inches when the frame is fully contracted. In some embodiments, the device 600, 700 has a maximum outer diameter D of about 0.12 inches or about 3 millimeters when the frame is fully expanded. 1 The device is configured to have:

[0090] In some embodiments, the membrane 610 further comprises a second portion 720 having a second porosity to blood flow that is different than the first porosity of the first portion 710 of the membrane 610 .

[0091] In some embodiments, a substantial majority of the aggregate porosity of the device 600 , 700 in the first portion of the membrane 610 is derived from the first porosity of the membrane 610 .

[0092] In some embodiments, each of the wires 640 is made of at least one of superelastic nitinol, cobalt chromium alloy, and nitinol shape memory alloy. In some embodiments, the membrane 610 is made of a polymer. In some embodiments, each of the wires 640 is coated with a polymer 1210 configured to significantly reduce exposure of the wires 640 to blood, thereby significantly reducing the thrombogenicity of the coated wires compared to uncoated wires.

[0093] This disclosure now refers to Figure 13, which shows a flow chart for an exemplary method of manufacturing a device for temporary protection of an aneurysmal neck of a blood vessel, as described elsewhere in this disclosure.

[0094] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0095] Step 1602 includes coiling (e.g., looping, braiding, joining, or arranging) a plurality of wires to form a contractible frame configured to expand to substantially conform to the shape of the inner surface of a blood vessel. For example, as described above, wire 640 may be coiled to form a contractible frame configured to expand to substantially conform to the shape of the inner surface of blood vessel 100.

[0096] Step 1604 includes disposing a retention wire at a proximal end of a frame of wires. For example, as previously described, retention wire 630 can be disposed at a proximal end of a frame of wires 640.

[0097] Step 1606 includes placing a membrane around substantially the entire circumference of the predetermined length of the frame, the membrane having at least a first portion having a first porosity to blood flow and configured to be placed directly against the neck of the aneurysm. For example, as previously described, the membrane 610 may be placed around the predetermined length L of the frame. 2 The membrane 610 may be disposed around substantially the entire circumference of the aneurysm 120. The membrane 610 may include a first portion 710 having at least a first porosity to blood flow and configured to be positioned directly against the neck of the aneurysm 120.

[0098] In some embodiments, the method according to this flowchart may include an optional step 1608 that includes coating each of the plurality of wires with a polymer configured to significantly reduce the exposure of the plurality of wires to blood, thereby significantly reducing the thrombogenicity of the coated wire compared to an uncoated wire. For example, each wire 640 may be coated with a polymer 1210 configured to significantly reduce the exposure of the wire 640 to blood, thereby significantly reducing the thrombogenicity of the coated wire compared to an uncoated wire. Dip coating may also bond the wires to each other at crossover points, providing a good bond between the electrospun membrane and the frame.

[0099] In some embodiments, the method according to this flowchart may include an optional step 1610 that includes forming a second portion of the membrane having a second porosity to blood flow that is different from the first porosity of the first portion of the membrane. For example, the second portion 720 of the membrane 610 may be formed with a second porosity to blood flow that is different from the first porosity of the first portion 710 of the membrane 610.

[0100] In some embodiments, the method according to this flowchart may include optional steps corresponding to providing, forming, or assembling any feature of any of the devices 600, 700 described herein.

[0101] Intravascular flow diverter FIELD OF THE DISCLOSURE The present disclosure relates to intravascular flow diverters and methods of using and / or manufacturing same. Several exemplary embodiments of such intravascular flow diverters and associated methods are described herein with reference to one or more drawings.

[0102] Endovascular repair of fusiform or bifurcation aneurysms is challenging due to complex flow geometries, side branch vessels at the bifurcation point, and the possibility of perforating vessels that it is desirable to preserve. Thus, there is a need for improved endovascular flow diverters and associated methods of using and / or manufacturing the same.

[0103] FIG. 14A shows a portion of a blood vessel 110. The blood vessel 110 is shown to include one or more branch vessels 130 and an aneurysm 120, which is shown bulging beyond adjacent portions of the blood vessel 110. FIG. 14A shows blood flow through the blood vessel 110 in the area surrounding the aneurysm 120. Often, particularly for wider neck aneurysms, a portion of the blood vessel flow 150 passing the aneurysm neck is diverted into the aneurysm as an aneurysm inflow flow 155 where it may circulate backwards and then re-enter the blood vessel flow 150 as an aneurysm outflow flow 165. This intravascular circulation presses outward against the walls of the aneurysm, causing it to expand and possibly rupture. Endovascular repair of fusiform or bifurcated aneurysms is challenging due to the complex flow geometry, side branch vessels at the bifurcation point, and the possibility of blood flow 151, 153 perforating the vessel that is desired to be preserved.

[0104] Treatment of this type of aneurysm 120 may involve the use of a flow diverter to bypass the affected area. One contemporary treatment involves the use of a Medtronic pipeline flow diverter 205 having a dense braid of 64×0.001 inch diameter wires configured to bridge the aneurysm 120. This is shown diagrammatically in FIG. 14B. The very dense wire braiding provides resistance to blood flow through the sidewalls of the pipeline flow diverter 270. However, the very dense wire braiding, along with the wires being constructed from cobalt chromium wires, can make the pipeline flow diverter very difficult to deploy. Furthermore, to completely occlude flow to some of the aneurysms 120, multiple pipeline flow diverters must often be deployed coaxially within one another to achieve the desired cessation of inflow blood flow to the aneurysm 120. This is an expensive and complicated procedure.

[0105] For these reasons and others, there is a need for improved flow diverters for treating aneurysms and associated methods of using and / or manufacturing same. Accordingly, in some embodiments described herein, an intravascular flow diverter for treating aneurysms in a blood vessel is provided. The diverter includes a stent including a plurality of wires coiled to form an expandable structure. The diverter includes a membrane disposed over an outer surface of the stent. The membrane includes a first portion configured to be positioned directly against the neck of the aneurysm. The membrane includes at least one second portion configured to be positioned adjacent to but not directly over the aneurysm. The first portion has a first porosity to blood flow and the second portion has a second porosity to blood flow that is higher than the first porosity. Common locations for intracranial aneurysms include the communicating arteries, the internal carotid arteries, and the middle cerebral arteries. The devices described herein can be used, for example, in these arteries.

[0106] In some other embodiments, a method is provided that utilizes an intravascular flow diverter to treat an aneurysm in a blood vessel. The method includes disposing the intravascular flow diverter in a microcatheter. The method includes threading the microcatheter through a blood vessel to a location of the aneurysm. The method includes removing the intravascular flow diverter from a distal end of the microcatheter in a manner that an intravascular flow diverter stent including a plurality of wires coiled to form an expandable structure expands in the blood vessel sufficiently such that a first portion of a membrane disposed over an outer surface of the stent is disposed directly against the neck of the aneurysm and at least one second portion of the membrane is disposed adjacent to but not directly over the aneurysm. The first portion has a first porosity to blood flow and the at least one second portion has a second porosity to blood flow that is higher than the first porosity.

[0107] In some other embodiments, a method of manufacturing an endovascular flow diverter configured to treat an aneurysm in a blood vessel is provided. The method includes coiling a plurality of wires to form an expandable stent. The method includes disposing a membrane over an exterior surface of the stent in a manner in which the membrane includes a first portion configured to be positioned directly against the neck of the aneurysm and at least one second portion having a second porosity to blood flow that is greater than the first porosity and configured to be positioned adjacent to but not directly over the aneurysm.

[0108] The intravascular flow diverter improvements described herein may include a stent comprising a self-expanding and / or balloon expandable braid of wire 420 (which may be constructed using known techniques including, but not limited to, braiding and / or laser cutting) and coated with a thin film 410 comprising one or more portions 310, 320a and 320b having one or more desired porosities. Details of the intravascular flow diverter 300 are described in more detail in connection with Figures 16-18C.

[0109] As shown in FIG. 15 , a flow diverter 300 comprising the collapsible contracted stent and membrane can be placed within a microcatheter 200 and microcatheter 207 threaded through the blood vessel 100 until the flow diverter 300 is positioned directly adjacent to the aneurysm 120 in order to eliminate blood flow into the aneurysm 120, thereby relieving stress on the walls of the aneurysm 120.

[0110] Once the flow diverter 300 stent is properly positioned immediately adjacent to the aneurysm 120 in the blood vessel 100, it may be allowed to self-expand under a bias from a plurality of interwoven wires 420 (see, e.g., FIGS. 17-18C), as shown, for example, in FIG. 16, and / or may be manually expanded using an expansion balloon (not shown) positioned within at least a portion of the contracted stent.

[0111] 16, the endovascular flow diverter 300 may include a first portion 310 configured to be placed directly over the neck of the aneurysm 120. The first portion 310 has a first porosity that prevents inflow 155 and outflow 165 of circulating blood. This may be accomplished, for example, by depositing a relatively thick multi-layer mat of electrospun fibers onto the stent frame in this region, essentially preventing a large number of pores from extending through the thickness of the covering, resulting in a porosity of, for example, 0-0.05 (5%).

[0112] In other embodiments, it has been found that this inflow 155 and outflow 165 blocking function can be provided by a membrane with surprisingly high porosity and large pore size. In general, porosity and pore size should be appropriately balanced to produce a membrane with low permeability to the inflow 155 and outflow 165 flows in the presence of vascular flow 150. Higher total porosity requires smaller pore size, while lower porosity can have larger pore size while still maintaining the desired inflow 155 and outflow 165 inhibition. This can be evaluated in a more quantitative manner by considering the product of the median pore size and the total fractional porosity as a characterization of the cover porosity distribution. For advantageous flow diverter cover membranes, this product can be in the range of 0.5 to 50, with 5 to 20 being found to be particularly suitable. For example, a suitable membrane can have a total porosity of 0.05 to 0.5 and a median pore size of 10 to 100 microns. In one embodiment, a membrane with a porosity of 0.3-0.6 and a median pore size of 20-30 is utilized. In another embodiment, a membrane with a total porosity of 0.05-0.15 and a median pore size of 30-100 microns is utilized. In another embodiment, a membrane with a total porosity of 0.15-0.25 and a median pore size of 20-80 microns is utilized. In any of the embodiments described herein, the pore size range can be 5-400 microns, 5-200 microns, or 5-100 microns. Outliers outside these ranges that do not contribute significantly to the total porosity of the cover (e.g., less than 5% of the total porosity) are ignored.

[0113] In some embodiments, the intravascular flow diverter 305 may further comprise one or more second portions 320a, 320b adjacent the first portion 310 and configured to allow increased blood flow through the side branch 130 of the blood vessel 100 as compared to reduced or substantially eliminated blood flow through the first portion 310 and into the aneurysm 120. The second portion 320 has a second porosity that is higher than the first porosity of the first portion 310 (e.g., a porosity between 0.05 and 0.4). In some embodiments, one of the second portions 320 may have a different porosity than either the first portion 310 or the other second portion 320. Thus, the flow diverter 305 may be configured to address sidewall aneurysms, bifurcation aneurysms, and fusiform aneurysms.

[0114] Electrospun stent cover membranes having porosity and permeability suitable to achieve one or more of these functions are described in U.S. Patent Application Publication No. 2021 / 0052360, paragraphs

[0092] to

[0103] , which paragraphs are incorporated herein by reference.

[0115] 17, the flow diverter 305 comprises a number of wires 420 braided around one another. For example, in some embodiments, each of the wires 420 has a predetermined length L when fully expanded. 1 (e.g., about 0.79 inches, i.e., 20 mm, although any other suitable length is contemplated) and a predetermined maximum diameter D 1 (e.g., 0.18 inches or 4.5 mm, although any other suitable diameter is contemplated). In some such embodiments, each wire 420 may be coiled into a generally helical shape or structure that is contractible and expandable and configured to have a predetermined distance L from an adjacent wire 420. 3 In some embodiments, each of the wires 420 is offset by a predetermined pitch L 2 (i.e., each loop or turn of a particular one of the wires 420 may have a predetermined length L along the length of extension of the flow diverter 305. 2In some such embodiments, the spacing L extends (e.g., about 0.18 inches, i.e., 4.5 mm, although any other suitable length is contemplated). 3 is the pitch L of the wire 420 2 4. The wires 420 of one subset may be wound in a clockwise direction, while the wires 420 of the other subset may be wound in a counterclockwise direction. Thus, when the wires 420 of the subset are wound in opposite directions, the wires 420 of one subset may be wound in a counterclockwise direction, while the wires 420 of the other subset may be wound in a counterclockwise direction. 1 will overlap at multiple points along the

[0116] In some embodiments, the frame is configured to stretch as it contracts, thereby minimizing the contracted diameter of the frame. The above geometry of the wire 420 advantageously provides for easy unhindered expansion of the flow diverter 305 in vivo. In some embodiments, the wire 420 is made of superelastic Nitinol. In some other embodiments, cobalt chrome may be used. In still other embodiments, Nitinol shape memory alloy may be used. However, the disclosure is not so limited and the wire 420 may be made of any suitably flexible, expandable and compressible material.

[0117] As can be most easily seen in any of Figures 5A-5C, each of the wires 420 may be further coated with a polymer 510, which may be a dip coating configured to significantly reduce or minimize exposure of the metal to blood. The dip coating may also bond the wires to each other at the crossover points. In some embodiments, the polymer 510 comprises an elastic polymer.

[0118] As further shown in FIG. 17, the flow diverter 305 may have a circumferential extension L of at least a portion, typically the entirety of the outer surface of the flow diverter 305, e.g., a circumferential extension L of substantially the entire perimeter. 1 For example, in some embodiments, the membrane 410 may extend along the entire extension length L of the flow diverter 305, as shown in FIG. 1 Membrane 410 has a generally cylindrical shape when arranged parallel to wires 420. Membrane 410 provides support for an underlying expansion frame of wires 420 and a thickness of, e.g., T 1 The dip coating can provide a nearly or substantially impermeable layer having an advantageously very thin construction with a good bond between the electrospun membrane and the frame.

[0119] The supporting membrane 410 and this nearly impermeable layer cooperate to allow for a reduced number of wires 420 (e.g., 6, 8, 12 or 16 wires 420) required for construction and effective operation, as compared to, for example, the Medtronic pipeline flow diverter (which has and requires, for example, 64 wires). While the Medtronic pipeline flow diverter, for example, relies on the density and proximity of a large number (e.g., 64) of individual wires to provide sufficient support against the vessel wall and also provide sufficiently low porosity to prevent blood flow into the aneurysm, at least a portion of the support required against the wall of the vessel 110 and most of the required low permeability of the flow diverter 305 is provided by the cover membrane 410.

[0120] The cover 410 can provide support for the underlying expansion frame of struts 640 while also having a very thin construction. The cover membrane 410 providing such support allows for a reduction in the number of wires 420 required for construction and effective operation compared to conventional devices without such a membrane. The cover membrane allows for increased frame porosity. In some embodiments, the frame porosity over most, substantially all or all of its length is greater than 90%, preferably greater than 93%, and more preferably greater than 95%.

[0121] This reduction in strut area (increased frame porosity) advantageously reduces the device mass per unit length, the delivery profile as it navigates the aneurysm 120 in the delivery system, the longitudinal stiffness of the device 305, and the radial forces it exerts. All of these improvements, individually and collectively, allow for easier tracking within the vasculature and improved delivery and deployment of the device 300. This is particularly true and advantageous for smaller and / or tortuous vessel applications, such as those of the brain, where the ratio of the device's retracted radius to properly deployed radius can be much smaller than in larger vessel applications, such as the aorta.

[0122] This reduction in wire count also advantageously reduces the delivery profile, longitudinal stiffness of the diverter 305, and radial forces exerted by the delivery system as it navigates the aneurysm 120. All of these improvements, individually and collectively, allow for easier tracking within the vasculature and improved delivery and deployment of the diverter 305. This is particularly true and advantageous for smaller and / or tortuous vessel applications, such as those of the brain, where the ratio of the retracted radius to the properly deployed radius of the diverter 305 may be much smaller than in larger vessel applications, such as the aorta.

[0123] Additionally, the reduced number of wires 420 also provides more uniform porosity across the neck of the curve of the diverter 300, at least because fewer wires are packed to a lesser extent inside the curve. And because the porosity along the length of the diverter 305 is largely controlled by the porosity and / or permeability of the membrane 410, the porosity and / or permeability of the membrane 410 can be customized to allow substantially no or very little blood flow through or to areas of the membrane 410 that directly cover the diseased vessel wall of the aneurysm 120 (see, for example, the portion of the membrane 410 shown in FIG. 17 forming the first portion 310 shown in FIG. 16), thereby allowing clots to form, organize and scar to provide an effective long-term treatment, while at the same time allowing a sufficient increase in blood flow to or through areas of the membrane 410 that are adjacent to but covering or not directly adjacent the diseased vessel wall of the aneurysm 120 (see, for example, the portion of the membrane 410 forming the lateral second portion 320 in FIG. 16), thereby allowing sufficient blood flow through the side branch 130 of the blood vessel 100.

[0124] Thus, in some embodiments, the density and / or porosity of the membrane 410 is adjusted to have different or variable values ​​at different locations, thereby providing a relatively high porosity in the second portion 320 (for positioning adjacent the side branch 130) and a relatively low porosity in the first portion 310 (for positioning at the aneurysm 120 where isolation from blood flow and clotting outside the stent should be promoted). In such embodiments, areas of the vessel 110 having perforated vessels or side branches 130 that require maintained blood flow are advantageously made viable by the increased blood flow through the second portion 320 of the membrane 410. The above-mentioned advantages may also directly alleviate the need for a physician to use multiple flow diverters to achieve blood flow stasis for blood flow into the aneurysm 120.

[0125] Another advantage of the membrane 410 applied to a stent formed from wire 420 is that the porosity and therefore flow control provided by the membrane 410 allows smaller diverters 305 to be available and / or used compared to existing flow diverters, all of which have a very narrow range of vessel diameters over which each size is effective in isolating blood flow. For example, while traditional wire braids are typically available in ¼ mm increments, in at least some embodiments, the flow diverters 305 may be available in much larger increments of size, e.g., 1.0-1.5 mm, allowing the diverters 300 to be 4-6 times smaller in size compared to traditional wire braided stents.

[0126] Additionally, the flow diverter 305 may have improved capabilities for use with coil or intrasaccular flow diverters, such as in the event of inadvertent aneurysm rupture when using the flow diverter 305 in combination with said coil or intrasaccular flow diverter, where the flow diverter 305 provides additional hemostasis via the membrane 410 compared to traditional dense wire braided stents.

[0127] It is also contemplated that the wire 420 may have one of a variety of different thicknesses depending on the requirements of the desired application. Figures 18A-18C show cross sections of first through third exemplary embodiments of an intravascular flow diverter 305, for example, as viewed along section line AA' shown in Figure 17. Each of the embodiments of Figures 18A-18C may be substantially similar to one another, except that each utilizes a wire 420 having a different diameter, and thus the diverter 305 of each illustrated embodiment also has a respective minimum contraction diameter.

[0128] As shown in FIG. 18A, the wire 420 has an outer diameter of about 0.002 inches, and the diverter 305 is accordingly sized to a minimum contracted diameter D 2 (e.g., 0.011 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0129] As shown in FIG. 18B, the wire 420 has an outer diameter of about 0.0015 inches, and the diverter 305 is accordingly sized to a minimum contracted diameter D 3 (e.g., 0.008 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0130] As shown in FIG. 18C, the wire 420 has an outer diameter of about 0.001 inches, and the diverter 305 is accordingly sized to a minimum contracted diameter D 4 (e.g., 0.006 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0131] 18A-18C, the exemplary orientation of wire 420 in the contracted state includes an innermost subset of eight threads and an outermost subset of eight threads. Each of the innermost threads is disposed in direct contact with each of two adjacent threads of the innermost subset and one thread of the outermost subset. The center of each of the outermost threads is radially collinear with both the center of the cross section of the frame and the center of the corresponding inner thread with which it is in direct contact.

[0132] This disclosure now refers to Figure 19, which shows a flow chart for an exemplary method of utilizing an intravascular flow diverter 305, as described elsewhere in this disclosure.

[0133] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0134] Step 602 includes disposing an intravascular flow diverter within the microcatheter. For example, the intravascular flow diverter 305 can be disposed within the microcatheter 207, as described above in connection with at least FIG.

[0135] Step 604 includes threading a microcatheter through the blood vessel to the location of the aneurysm. For example, a microcatheter 207 can be threaded through the blood vessel 110 to the location of the aneurysm 120, as described above in connection with at least FIG.

[0136] Step 606 includes removing the intravascular flow diverter from the distal end of the microcatheter in a manner in which an intravascular flow diverter stent comprising a plurality of wires coiled to form an expandable structure expands in the blood vessel sufficiently such that a first portion of a membrane disposed over the exterior surface of the stent is positioned directly against the neck of the aneurysm, the first portion having a first porosity to blood flow, and at least one second portion of the membrane is positioned adjacent to but not directly over the aneurysm, the at least one second portion having a second porosity to blood flow that is greater than the first porosity.

[0137] For example, as described above in connection with at least one of Figures 15-18C, the intravascular flow diverter 305 can be removed from the distal end of the microcatheter 207 (see, e.g., Figure 15) in the following manner: In that manner, a stent of the intravascular flow diverter 305 comprising a wire 420 coiled to form an expandable structure expands within the blood vessel 110 sufficiently such that a first portion 310 of the membrane 410 is positioned directly against the neck of the aneurysm 120 and at least one second portion 320 of the membrane 410 is positioned adjacent to, but not directly over, the aneurysm 120. The first portion 310 has a first porosity to blood flow and the second portions 320a, 320b have a second porosity to blood flow that is greater than the first porosity.

[0138] In some embodiments, the method according to this flowchart may include an optional step 608 of expanding the plurality of wires by expanding the balloon from within the generally helical shape. For example, as described above in connection with at least one of Figures 15-18C, the balloon may be expanded from within the generally helical shape of the wires 420 if the wires 420 are not configured to self-expand under their self-bias.

[0139] In some embodiments, the expandable structure comprises a plurality of wires 420 each wound in a generally helical shape. In some embodiments, each of the wires 420 has a predetermined pitch L 2 In some embodiments, the first subset of wires 420 are wound in a clockwise direction and the second subset of wires 420 are wound in a counterclockwise direction. In some embodiments, each of the wires 420 is spaced a predetermined distance L from at least one adjacent wire 420. 3The plurality of wires are offset by 100%. In some embodiments, the plurality of wires is one of 6 wires, 8 wires, 12 wires, and 16 wires. In some embodiments, the wires 420 are configured to self-expand under a self-bias when the intravascular flow diverter 305 is removed from the microcatheter 207. In some embodiments, threading the microcatheter 207 through the blood vessel 110 to the location of the aneurysm 120 comprises positioning at least one of the at least one second portion 320 directly over a side branch 130 of the blood vessel 110. In some embodiments, the first porosity is sufficiently low such that when the intravascular flow diverter 305 is properly positioned within the blood vessel 110, the first portion 310 of the membrane 410 is configured to substantially not allow blood flow therethrough, thereby allowing blood clots to form and ultimately scar over the aneurysm 120. In some embodiments, the second porosity is sufficiently high such that at least one of the at least one second portions 320 of the membrane 410 is configured to permit substantial blood flow therethrough directly into the side branch 130 of the blood vessel 110 when the intravascular flow diverter 305 is properly positioned within the blood vessel 110. In some embodiments, each of the wires 420 has a diameter of one of about 0.002 inches, about 0.015 inches, and about 0.001 inches (see, e.g., FIGS. 18A-18C). In some embodiments, the intravascular flow diverter 305 has a minimum outer diameter D of one of about 0.011 inches, about 0.008 inches, and about 0.006 inches when the expandable structure of the stent is fully contracted. 2 , D 3 , D 4 (See, e.g., FIGS. 18A-18C.) In some embodiments, the intravascular flow diverter 300 has a maximum outer diameter D of about 0.18 inches when the expandable structure of the stent is fully expanded. 1 In some embodiments, a substantial majority of the aggregate porosity of the intravascular flow diverter 305 at the first and second portions 310, 320 of the membrane 410 is derived from the first and second porosities of the membrane 410 at the first and second portions 310, 320, respectively.

[0140] The present disclosure now refers to Figure 20, which shows a flow chart for an exemplary method of manufacturing an intravascular flow diverter as described elsewhere in this disclosure.

[0141] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0142] Step 702 includes coiling (e.g., looping, braiding, joining, or arranging) a plurality of wires to form a collapsible stent. For example, as described above in connection with at least one of Figures 15-18C, coiled wire 420 may be coiled to form a collapsible stent.

[0143] Step 704 includes disposing a membrane over the exterior surface of the stent in a manner in which the membrane comprises a first portion having a first porosity to blood flow and configured to be positioned directly against the neck of the aneurysm, and at least one second portion having a second porosity to blood flow that is greater than the first porosity and configured to be positioned adjacent to, but not directly over, the aneurysm.

[0144] For example, as described above in connection with at least one of Figures 15-18C, the membrane 410 may be disposed over the exterior surface of the stent in the following manner, in which the membrane 410 comprises a first portion 310 having a first porosity to blood flow and configured to be positioned directly against the neck of the aneurysm 120, and at least one second portion 320 having a second porosity to blood flow that is greater than the first porosity and configured to be positioned adjacent to, but not directly over, the aneurysm 120.

[0145] In some embodiments, coiling the wire 420 comprises winding each of the wires 420 in a generally helical shape. In some embodiments, each of the wires 420 has a plurality of helical loops each having a predetermined pitch L. 2 In some embodiments, the wires 420 of the first subset are wound in a clockwise direction and the wires 420 of the second subset are wound in a counterclockwise direction. In some embodiments, each of the wires 420 is separated from at least one adjacent wire 420 by a predetermined distance L. 3In some embodiments, the plurality of wires 420 is one of 6 wires, 8 wires, 12 wires, and 16 wires. In some embodiments, the wires 420 are configured to self-expand under a self-bias. In some embodiments, the wires 420 are configured to expand under the influence of a balloon configured to expand from within a generally helical shape. In some embodiments, the intravascular flow diverter 305 is configured to be disposed in a contracted configuration within a microcatheter 207 configured to be threaded through the blood vessel 100 to the location of the aneurysm 120 (see, e.g., FIG. 15 ). In some embodiments, at least one of the at least one second portion 320 is configured to be disposed directly over a side branch 130 of the blood vessel 110. In some embodiments, the first porosity is sufficiently low such that when the intravascular flow diverter 305 is properly positioned within the blood vessel 110, the first portion 310 of the membrane 410 is configured to substantially permit blood flow therethrough to cause a blood clot to form and ultimately scar over the aneurysm 120. In some embodiments, the second porosity is sufficiently high such that at least one of the at least one second portions 320 of the membrane 410 is configured to permit substantial blood flow therethrough into the side branch 130 of the blood vessel 100 when the intravascular flow diverter 305 is properly positioned within the blood vessel 110. In some embodiments, each of the wires 420 is provided having a diameter of one of about 0.002 inches, about 0.015 inches, and about 0.001 inches (see, e.g., FIGS. 18A-18C). In some embodiments, the intravascular flow diverter 305 has a minimum outer diameter D of one of about 0.011 inches, about 0.008 inches, and about 0.006 inches when the expandable structure of the stent is fully contracted. 2 , D 3 , D 4 (See, e.g., FIGS. 18A-18C.) In some embodiments, the intravascular flow diverter 305 is configured to have a maximum outer diameter D of about 0.18 inches when the expandable structure of the stent is fully expanded. 1(See, e.g., FIGS. 18A-18C). In some embodiments, a substantial majority of the aggregate porosity of the intravascular flow diverter 305 at the first and second portions 310, 320 of the membrane 410 is derived from the first and second porosity of the membrane 410 at the first and second portions 310, 320, respectively. In some embodiments, each of the wires 420 is comprised of at least one of superelastic nitinol, cobalt chromium, and nitinol shape memory alloy.

[0146] Intracapsular flow diverter The present disclosure relates to intracapsular flow diverters and associated methods of using and / or manufacturing the same. In some embodiments, the intracapsular flow diverters described anywhere herein may be considered as intracapsular neural flow diverters configured for application in at least the tortuous vasculature of the brain. Several exemplary embodiments that overcome many of the limitations of current devices are described herein in conjunction with one or more of the drawings.

[0147] FIG. 21A illustrates a portion of a blood vessel 110. The blood vessel 110 is shown as including one or more branch vessels 130 and an aneurysm 120, which are shown bulging beyond adjacent portions of the blood vessel 110. FIG. 21A illustrates blood flow through the blood vessel 110 in the area surrounding the aneurysm 120. In many cases, particularly for wide-necked aneurysms, a portion of the blood vessel flow 150 passing the aneurysm neck is diverted into the aneurysm as aneurysm inflow flow 155, where it may circulate backwards before re-entering the blood vessel flow 150 as aneurysm outflow flow 165. This intravascular circulation presses outward against the walls of the aneurysm, causing it to expand and possibly rupture. Endovascular repair of fusiform or bifurcated aneurysms is challenging due to the complex flow geometry, side branch vessels at the bifurcation point, and the possibility of blood flow 151, 153 perforating the vessels that it is desired to preserve.

[0148] Endovascular repair of sidewall or branch aneurysms is not always amenable to standard procedures. One type of such aneurysm may include those with particularly wide-necked anatomical configurations. Conventional treatment of some such aneurysms involves the use of balloons to support and block flow in the parent vessel and associated aneurysms while coil embolization of the aneurysm is achieved. Traditionally, coils have been used to fill the aneurysmal sac due to their inherent softness. However, such coils lack sufficient retention in large-necked aneurysms. Other difficulties may be presented by nearby branch vessels 130 that may preclude the use of conventional fluid-impermeable stents in vessel 110 across the neck of the aneurysm 120.

[0149] One option is to deploy an intrasaccular occluder within the aneurysm sac. This is shown in FIG. 21A. An example of such a device is the Microvention WEB device 270, a high-density braid of superelastic Nitinol wire that deploys into a 3D shape configured for insertion into the aneurysm sac. However, the WEB device is composed of dozens of wires that form the braid. This makes the device very stiff to manipulate during its initial deployment before it begins to soften by allowing the device to extend sufficiently from the microcatheter to begin to open. These devices attempt to exclude the aneurysm from the systemic circulation, resulting in the formation of a blood clot as a result of the cessation of blood flow within the aneurysm.

[0150] In some embodiments, an intrasaccular flow diverter for treating aneurysms of a blood vessel is provided. The intrasaccular flow diverter includes a plurality of wires coiled to expand within the aneurysm to form a collapsible frame configured to substantially conform to the shape of the inner surface of the aneurysm. The intrasaccular flow diverter includes a membrane disposed on all or a portion of the outer surface of the frame. The membrane includes a first portion configured to be positioned directly against the neck of the aneurysm. The membrane may include a second portion configured to be positioned within the aneurysm and distal to the neck of the aneurysm. The first portion has a first porosity to blood flow and the second portion has a second porosity to blood flow that is higher than the first porosity. Common locations for intracranial aneurysms include the communicating artery, the internal carotid artery, and the middle cerebral artery. The devices described herein can be used, for example, within these arteries.

[0151] In some other embodiments, a method is provided that utilizes an intrasaccular flow diverter to treat an aneurysm of a blood vessel. The method includes disposing the intrasaccular flow diverter in a microcatheter in a contracted state. The method includes threading the microcatheter through the blood vessel to a location within the aneurysm. The method includes removing the intrasaccular flow diverter from a distal end of the microcatheter in a manner in which a plurality of coiled wires forming a contracted generally spherical frame of the intrasaccular flow diverter expands sufficiently within the aneurysm such that a first portion of a membrane disposed across an outer surface of the generally spherical frame is disposed directly against the neck of the aneurysm and a second portion of the membrane is disposed within the aneurysm and distal to the neck of the aneurysm. The first portion has a first porosity to blood flow and the second portion has a second porosity to blood flow that is greater than the first porosity.

[0152] In some other embodiments, a method of manufacturing an intrasaccular flow diverter configured to treat an aneurysm of a blood vessel is provided. The method includes coiling a plurality of wires to form a collapsible, generally spherical frame configured to expand within the aneurysm to substantially conform to a shape of the inner surface of the aneurysm. The method includes disposing a membrane on all or a portion of an outer surface of the frame in a manner in which the membrane comprises a first portion configured to be positioned directly against the neck of the aneurysm and a second portion configured to be positioned within the aneurysm and distal to the neck of the aneurysm. The first portion has a first porosity to blood flow and the second portion has a second porosity to blood flow that is greater than the first porosity.

[0153] Improvements to intrasaccular flow diverters as described herein may include a self-expanding frame of wires 420 configured to fill the aneurysmal sac and aid in remodeling the neck of the aneurysm 120, thereby preventing further growth of the aneurysm 120 (see, e.g., any of FIGS. 24A-24D). In some embodiments, each of the wires 420 may be encased in a polymer 510 configured to minimize exposure of the metal to the blood (see, e.g., any of FIGS. 25A-25D), and the entire frame of wires 420 is further encased in a polymeric membrane 410 having one or more portions 910, 920 having one or more respective desired porosities (see, e.g., FIG. 23). Details of such an intrasaccular flow diverter 900 are described in more detail in connection with at least FIGS. 23-25C.

[0154] For deployment as shown in FIG. 22, the flow diverter 900 can be placed in a contracted state within the microcatheter 200, and the microcatheter 200 can be threaded through the blood vessel 100 until the distal end of the microcatheter 200 is positioned within the aneurysm 120.

[0155] For example, as shown in FIG. 23, once properly positioned within the aneurysm 120, the flow diverter 900 can be pushed out of the distal end of the microcatheter 200 to allow the frame of the wire 420 to self-expand under a bias from the wire 420 itself (see, e.g., FIGS. 24A-25C).

[0156] As shown in FIG. 23, the intrasaccular flow diverter 900 may comprise a contracted or contractible generally spherical frame formed by wires 420 and configured to expand to substantially conform to the shape of the inner surface of the aneurysm 120 (see, e.g., FIGS. 24A-24D). The diverter 900 comprises a first portion 910 having a first desired porosity and configured for placement within and / or directly against the neck of the aneurysm 120, thereby protecting the neck of the aneurysm 120. The diverter 900 may further comprise a second portion 920 adjacent the first portion 910, having a second desired porosity greater than the first porosity of the first portion 910, and configured for placement within and distal to the neck of the aneurysm 120. The second portion 920 is configured for increasing blood flow perfusion therethrough as compared to reducing or substantially eliminating blood flow perfusion therethrough. 24A-24D, these aggregate first and second porosities of the first and second portions 910, 920 of the diverter 900 may be achieved generally and / or substantially entirely by manipulation of the porosity of corresponding portions of a membrane disposed on at least a portion of the outer surface of the frame, preferably the entire outer surface of the frame formed by the wires 420, rather than by utilization of an ultra-dense assembly of a greater number of wires, as in conventional intrasaccular occluders and / or stents. Thus, the flow diverter 900 may be configured to address sidewall and / or branch aneurysms, in some cases, that have sufficiently wide-necked anatomical geometries to contraindicate standard aneurysm procedures.

[0157] The cover membrane 910 has porosity, porosity distribution and permeability characteristics that substantially block the circulating aneurysmal inflow 155 and outflow 165 flows as shown in FIG. 21A. It has been found that this inflow 155 and outflow blocking function can be provided by a membrane with surprisingly high porosity and large pore size. In general, to produce a membrane with low permeability to the inflow 155 and outflow 165 flows in the presence of vascular flow 150, the porosity and pore size should be properly balanced. Higher total porosity requires smaller pore size, while lower porosity has larger pore size while still maintaining the desired inflow 155 and outflow 165 inhibition. This can be evaluated in a more quantitative manner by considering the product of the median pore size and the total fractional porosity as a characterization of the cover porosity distribution. It has been found that for an advantageous coil embolization support cover membrane, this product can be in the range of 0.5 to 50, with 5 to 20 being particularly suitable. For example, a suitable membrane may have a total porosity of 0.05-0.5 and a median pore size of 10-100 microns. In one embodiment, a membrane with a porosity of 0.3-0.6 and a median pore size of 20-30 microns is utilized. In another embodiment, a membrane with a total porosity of 0.05-0.15 and a median pore size of 30-100 microns is utilized. In another embodiment, a membrane with a total porosity of 0.15-0.25 and a median pore size of 20-80 microns is utilized. In any of the embodiments described herein, the pore size range may be 5-400 microns, 5-200 microns, or 5-100 microns. Outliers outside these ranges that do not significantly contribute to the total porosity of the cover (e.g., less than 5% of the total porosity) are ignored. Endothelial growth is enhanced by having a relatively small median pore size, such as between 10 and 50 microns, and a high porosity of greater than 0.3, more preferably greater than 0.4.

[0158] A relatively high porosity membrane that retains the ability to block large amounts of aneurysmal inflow 155 and outflow 165 has many advantages. For example, a higher porosity membrane allows for the use of a very high porosity wire frame by providing structural support to the device, thereby allowing for the fabrication of a highly flexible device that is more easily navigated through complex vasculature to the aneurysm. Electrospun stent cover membranes having suitable porosity and permeability to accomplish one or more of these tasks are described in U.S. Patent Application Publication No. 2021 / 0052360, paragraphs

[0092] to

[0103] , which are incorporated herein by reference.

[0159] 24A-24D, the flow diverter 900 comprises a plurality of wires 420 woven around one another to form a contracted and / or contractible (and similarly expanded and / or expandable) frame. For example, in some embodiments, each of the wires 420 has a predetermined maximum spherical diameter D when the wires 420 are fully expanded. 1 (e.g., about 0.18 inches, or 4.5 mm) into a plurality of contractible and expandable generally helical shapes or structures with a plurality of loops having successively increasing and then decreasing diameters. In some such embodiments, each wire 420 is spaced a predetermined distance L from an adjacent wire 420. 3 In some embodiments, each of the wires 420 may have a predetermined pitch (i.e., each loop or turn of a particular one of the wires 420 extends a predetermined length). In embodiments in which the frame has a generally spherical maximum expanded shape, this predetermined pitch may be offset by a diameter D of the frame. 1 For example, 0.18 inches, or 4.5 mm. In some such embodiments, the spacing L 3 is the pitch of the wire 420 or the diameter D in the appropriate embodiment. 124A-24D, a subset of the plurality of wires 420 (e.g., 8, 12, or 16 of the plurality of wires 420 in FIGS. 24A-B, 24C, and 24D, respectively) are wound in a clockwise direction, while another subset of the plurality of wires 420 (e.g., 8, 12, or 16 of the plurality of wires 420 in FIGS. 24A-B, 24C, and 24D, respectively) are wound in a counterclockwise direction. Thus, when the subsets of wires 420 are wound in opposite directions to one another, the wires 420 of one subset will have a predetermined maximum expanded diameter D 1 25A-25D, each of the wires 420 may be further coated with a polymer 510 configured to substantially reduce or minimize exposure of the metal to the blood.

[0160] As further shown in Figures 24A-24D, the flow diverter 900 includes a membrane 410 disposed over an outer surface of the flow diverter 900. For example, in some embodiments, the membrane 410 has a generally spherical morphology as shown in any of Figures 24A-24D. At least a portion of the membrane 410 may advantageously provide a nearly or substantially impermeable layer having a very thin configuration, for example, as a result of the electrospinning process utilized to form the membrane 410 from a polymer. In some embodiments that coagulate the aneurysm 120 by blood flow arrest and / or turbulence, the membrane 410 may be comprised of a highly extensible, solvent dispersible material with good anti-thrombogenic properties, rather than a highly thrombogenic material that would generate a clot.

[0161] The membrane 410 may also provide support for the underlying expansion frame of wires 420. This support function, in combination with providing a substantially impermeable layer in at least a portion of the membrane 410, allows for a reduction in the number of wires 420 (e.g., 8, 12 or 16 wires 420) required for construction and effective operation, as compared to, for example, Microvention's Web. While, for example, Microvention's Web provides sufficient support to the walls of the aneurysm 120 through the density and proximity of the large number (e.g., 144) of individual wires, and also provides sufficiently low porosity to prevent blood flow to the aneurysm 120, at least a portion of the necessary support for the inner surface of the aneurysm 120 is provided by the membrane 410 in any embodiment described herein. The membrane 410 additionally provides a force to assist in expanding the diverter 900, and much of the required low permeability of the flow diverter 900 is provided by the membrane 410.

[0162] This reduction in wire count also advantageously improves the in vivo navigation of the diverter 900. For example, when compared to wires of the same diameter, fewer wires 420 make the diverter 900 easier to navigate into the aneurysm 120 than other conventional designs due to the reduced moment of inertia of fewer and less massed wires. This is true when the diverter 900 is utilized in isolation as well as when the diverter 900 is utilized in conjunction with one or more of a stent-based diverter within the vessel 100 and / or coils disposed within the diverter 900 for additional wall contact, radial force, and / or filling of the aneurysm 120.

[0163] For example, in some embodiments, additional radial force may be applied to the aneurysm 120 by placing a coil within the diverter 300 after the diverter 900 has been deployed within the aneurysm 120 to fill the internal volume of the aneurysm 120. To accomplish this, the microcatheter 200 (see FIG. 2) may be repositioned adjacent the diverter 900 after the diverter 900 has been deployed within the aneurysm 120. A guidewire may be threaded through the microcatheter 200 and extended beyond the distal tip of the microcatheter 200 sufficiently to penetrate the membrane 410 of the diverter 900 and expand within the aneurysm 120. The microcatheter 200 may then be advanced over the guidewire into the diverter 900. A conventional coil may then be delivered into the diverter 900, if desired.

[0164] Another advantage of using fewer wires 420 compared to other conventional designs is the reduced stiffness of the diverter 900 during the initial portion of deployment. This reduced stiffness also translates to benefits to the diverter 900 in the deployed, expanded state, such as improved wall apposition in irregularly shaped aneurysms. All of these improvements, individually and collectively, allow for easier tracking into the vasculature and improved delivery and deployment of the diverter 900. This is particularly true and advantageous for smaller and / or tortuous vessel applications, such as those of the brain, where the winding radius within the vessel can be very tight and the ratio of the contracted radius to the properly deployed radius of the diverter 900 can be much smaller than in larger vessel applications, such as the aorta.

[0165] Because the porosity at any given point of the diverter 900 is generally controlled by the porosity and / or permeability of the membrane 410, the porosity and / or permeability of the membrane 410 can be customized, independent of the number or density of the wires 420, to allow little or substantially no blood flow through an area of ​​the membrane 410 configured to be positioned directly within and / or against the neck of the aneurysm 120 (see, for example, the portion of the membrane 410 in any of Figures 24A-24D that forms or coincides with first portion 910 in Figure 23), thereby protecting the neck of the aneurysm 120.

[0166] Thus, in some embodiments, the density and / or porosity of the membrane may be adjusted to have different or variable values ​​at different locations, thereby providing a relatively high porosity in the second portion 920 (e.g., 5-40% porosity) and a relatively low porosity in the first portion 910 (e.g., 0-5% porosity).

[0167] Additionally, the flow diverter 900 may have improved applicability for use with coils or endovascular flow diverters, such as in the event of inadvertent aneurysm rupture when using the flow diverter 900 in combination with said coils or endovascular flow diverters, where the flow diverter 900 provides additional hemostasis through the membrane compared to the dense wire braid of traditional intrasaccular occluders.

[0168] One advantage of traditional coils is that their softness can be customized or selected to provide minimal disruption or reformation of irregularly shaped aneurysms. The diverter 900 embodiments described herein include many fewer wires 420 than traditional diverters and can provide a similar advantage, at least in terms of the reduced force that can be applied to the walls of the aneurysm 120.

[0169] It is also contemplated that the wire 420 may have one of a variety of different thicknesses depending on the requirements of the desired application. Figures 25A-25D show cross-sectional views of first through fourth exemplary embodiments of an intrasaccular flow diverter 900 in a contracted state. Each of the embodiments of Figures 25A-25D may be substantially similar to one another, except that each utilizes a wire 420 having a different diameter, thus providing a different minimum diameter of the flow diverter 300 when in a fully contracted state.

[0170] As shown in FIG. 25A, the wire 420 has an outer diameter of about 0.0003 inches, and the diverter 900 is accordingly sized to a minimum contracted diameter D 2 (e.g., 0.002 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0171] As shown in FIG. 25B, the wire 420 has an outer diameter of about 0.0005 inches, and the diverter 900 is accordingly sized to a minimum contracted diameter D 3 (e.g., 0.003 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0172] As shown in FIG. 25C, the wire 420 has an outer diameter of about 0.0007 inches, and the diverter 900 is accordingly sized to a minimum contracted diameter D 4 (e.g., 0.004 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0173] As yet another example shown in FIG. 25D, the wire 420 has an outer diameter of about 0.001 inches and the diverter 900 is accordingly sized to a minimum contracted diameter D 5 (e.g., 0.006 inches) and maximum expansion diameter D 1 The signal may be configured to have the following characteristics:

[0174] The exemplary orientation of wire 420 in the contracted state shown in each of Figures 25A-25D comprises an innermost subset of eight threads and an outermost subset of eight threads. Each of the innermost threads is disposed in direct contact with each of two adjacent threads of the innermost subset and one thread of the outermost subset. The center of each of the outermost threads is radially collinear with both the center of the cross section of the frame and the center of the corresponding inner thread with which it is in direct contact.

[0175] This disclosure now refers to Figure 26, which shows a flow chart for an exemplary method of utilizing an intracapsular flow diverter, as described elsewhere in this disclosure.

[0176] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0177] Step 612 includes disposing an intrasaccular flow diverter in a deflated state within the microcatheter. For example, as described above in connection with at least FIG. 22, an intrasaccular flow diverter 900 may be disposed in a deflated state within the microcatheter 200.

[0178] Step 614 includes threading a microcatheter through the blood vessel to a location within the aneurysm. For example, a microcatheter 200 may be threaded through the blood vessel 100 to a location within the aneurysm 120, as described above in connection with at least FIG.

[0179] Step 616 includes removing the intrasaccular flow diverter from the distal end of the microcatheter in a manner in which the plurality of coiled wires forming the contracted generally spherical frame of the intrasaccular flow diverter expand within the aneurysm sufficiently such that a first portion of a membrane disposed across the outer surface of the generally spherical frame is positioned directly against the neck of the aneurysm, the first portion having a first porosity to blood flow, and a second portion of the membrane is positioned within the aneurysm and distal to the neck of the aneurysm, the at least one second portion having a second porosity to blood flow that is greater than the first porosity.

[0180] For example, as described above in connection with at least one of Figures 22-25C, the intrasaccular flow diverter 900 is removed from the distal end of the microcatheter 200 in the following manner, in which the wires 420 forming the contracted generally spherical frame of the intrasaccular flow diverter 900 expand sufficiently within the aneurysm 120 such that a first portion 910 of the membrane disposed across the outer surface of the generally spherical frame is disposed directly against the neck of the aneurysm 120 and a second portion 920 of the membrane is disposed within the aneurysm 120 and distal to the neck of the aneurysm 120. The first portion 910 has a first porosity to blood flow and the second portion 920 has a second porosity to blood flow that is greater than the first porosity.

[0181] In some embodiments, each of the wires 420 is wound in a generally helical shape. In some embodiments, each of the wires 420 includes a plurality of helical loops, each of which extends along a maximum expanded diameter D of the generally spherical frame. 1 In some embodiments, the plurality of helical loops have successively increasing and then decreasing diameters, thereby forming a generally spherical structure. In some embodiments, a first subset of wires 420 are wound in a clockwise direction and a second subset of wires 420 are wound in a counterclockwise direction. In some embodiments, each wire 420 is spaced a predetermined distance L from at least one adjacent wire 420. 1In some embodiments, wires 420 are one of 8 wires, 12 wires, and 16 wires. In some embodiments, wires 420 are configured to self-expand under a self-bias.

[0182] In some embodiments, the first porosity of the first portion 910 of the intracapsular flow diverter 900 is in the range of about 0-5%. In some embodiments, the second porosity of the second portion 920 of the intracapsular flow diverter 900 is in the range of about 5-40%.

[0183] In some embodiments, each of the wires 420 has a diameter of about one of 0.0003 inches, about 0.0005 inches, 0.0007 inches, and 0.001 inches. In some embodiments, the intracapsular flow diverter 900 has a minimum outer diameter D of about one of about 0.002 inches, about 0.003 inches, about 0.004 inches, and about 0.006 inches when the generally spherical structure is fully deflated. 2 , D 3 , D 4 , D 5 In some embodiments, the intracapsular flow diverter 900 is configured to have a maximum outer diameter D of about 0.18 inches when fully expanded as a generally spherical structure. 1 The device is configured to have:

[0184] In some embodiments, a substantial majority of the aggregate porosity of the intrasac flow diverter 900 at the first and second portions 910, 920 of the membrane 410 is derived from the first and second porosities of the membrane at the first and second portions 910, 920, respectively.

[0185] In some embodiments, each of the wires 420 is made of superelastic nitinol. In some embodiments, the membrane is made of a polymer. In some embodiments, the membrane is electrospun from a polymeric material. In some embodiments, each of the wires 420 is coated with a polymer 510 configured to substantially reduce exposure of the wires 420 to blood.

[0186] In some embodiments, wires 420 include a sufficiently small number of wires such that wires 420 that expand sufficiently into aneurysm 120 provide apposition of membrane 410 to the irregular shape of the inner surface of aneurysm 120 .

[0187] This disclosure now refers to Figure 27, which shows a flow chart for an exemplary method of manufacturing an intracapsular flow diverter, as described elsewhere in this disclosure.

[0188] Although the methods disclosed herein comprise one or more steps or actions for achieving the described method, such steps and / or actions may be interchangeable with one another and / or any subset of these steps and / or actions may be used without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be varied without departing from the scope of the claims. One or more additional steps not specifically recited herein may also be included.

[0189] Step 712 includes coiling a plurality of wires to form a collapsible, generally spherical frame configured to expand within the aneurysm and substantially conform to the shape of its interior surface.

[0190] For example, as described above in connection with at least one of Figures 22-25C, the wire 420 can be coiled to form a contractible, generally spherical frame configured to expand within the aneurysm 120 to substantially conform to the shape of its inner surface.

[0191] In some embodiments, coiling the plurality of wires to form a contractible generally spherical frame comprises winding each of the wires 420 in a generally helical shape. In some embodiments, winding each of the plurality of wires wound in a generally helical shape comprises winding each of the wires 420 such that each of the wires 420 has a maximum expanded diameter D of the generally spherical frame. 1forming a plurality of helical loops having a predetermined pitch substantially equal to . In some embodiments, the plurality of helical loops are wound to have successively increasing and then decreasing diameters, thereby forming a generally spherical structure. In some embodiments, a first subset of wires 420 are wound in a clockwise direction and a second subset of wires 420 are wound in a counterclockwise direction. In some embodiments, each wire 420 is spaced a predetermined distance L from at least one adjacent wire 420. 1 In some embodiments, the wires 420 are one of 8 wires, 12 wires, and 16 wires. In some embodiments, the wires 420 are configured to self-expand under a self-bias. In some embodiments, each of the plurality of wires has a diameter of one of about 0.0003 inches, about 0.0005 inches, 0.0007 inches, and 0.001 inches. In some embodiments, each of the plurality of wires is made of superelastic Nitinol. In some embodiments, the wires 420 include a sufficiently small number of wires to allow apposition of the membrane against the irregular shape of the inner surface of the aneurysm 120 when the intrasaccular flow diverter 900 is properly positioned within the aneurysm 120.

[0192] In some embodiments, the intracapsular flow diverter 900 has a minimum outer diameter D of one of about 0.002 inches, about 0.003 inches, about 0.004 inches, and about 0.006 inches when the generally spherical structure is fully deflated. 2 , D 3 , D 4 , D 5 In some embodiments, the intracapsular flow diverter 900 is configured to have a maximum outer diameter D of about 0.18 inches when fully expanded as a generally spherical structure. 1 The device is configured to have:

[0193] Step 714 includes disposing the membrane over the exterior surface of the frame in a manner in which the membrane comprises a first portion having a first porosity to blood flow and configured to be positioned directly against the neck of the aneurysm, and a second portion having a second porosity to blood flow that is greater than the first porosity and configured to be positioned within the aneurysm and distal to the neck of the aneurysm.

[0194] For example, as discussed above in connection with at least one of Figures 22-25C, the membrane may be disposed over the exterior surface of the frame in the following manner, in which the membrane comprises a first portion 910 having a first porosity to blood flow and configured to be positioned directly against the neck of the aneurysm 120, and a second portion 920 having a second porosity to blood flow that is greater than the first porosity and configured to be positioned within the aneurysm 120 and distal to the neck of the aneurysm 120.

[0195] In some embodiments, the first porosity is in the range of about 0-5%. In some embodiments, the second porosity is in the range of about 5-40%. In some embodiments, a substantial majority of the aggregate porosity of the intrasac flow diverter 900 at the membrane first and second portions 910, 920 is derived from the membrane first and second porosities at the membrane first and second portions 910, 920, respectively. In some embodiments, the cover membrane is electrospun from a polymeric material.

[0196] In some embodiments, the method according to flowchart 700 may include an optional step 716 that includes coating each of the plurality of wires with a polymer configured to substantially reduce exposure of the plurality of wires to blood.

[0197] For example, as described above in connection with at least one of Figures 22-25C, each of the wires 420 may be coated with a polymer configured to substantially reduce exposure of the wires 420 to blood.

[0198] General Rules of Interpretation of This Disclosure Various aspects of the novel system, apparatus and method are described more fully below with reference to the accompanying drawings. However, the disclosed teachings can be embodied in many different forms and should not be construed as being limited to any specific structure or function presented throughout this disclosure. These aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art will understand that the scope of the disclosure includes any aspect of the novel system, apparatus and method disclosed herein, whether implemented independently or in combination with any other aspect of the disclosure. For example, a system or apparatus may be implemented or a method may be practiced using any one or more of the aspects described herein. Furthermore, the scope of the disclosure includes such systems, apparatus or methods implemented using other structures, functions, or structures and functions in addition to or other than the various aspects of the disclosure described herein. It should be understood that any aspect disclosed herein may be described in one or more elements of a claim. Although some benefits and advantages of the preferred aspects are described, the scope of the disclosure is not limited to any particular advantage, use, or problem. The detailed description and drawings are merely illustrative of the disclosure rather than limiting, the scope of which is defined by the following claims and their equivalents.

[0199] With respect to the use of singular terms for plural terms herein, those of skill in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. Various singular / plural permutations may be expressly set forth herein for clarity.

[0200] When describing absolute values ​​of features or characteristics of objects or operations described herein, the terms "substantially," "substantially," "essentially," "about," and / or other terms or phrases of degree may be used without specifically reciting a numerical range. These terms, when applied to a feature or characteristic of an object or operation described herein, refer to a range of the feature or characteristic consistent with providing a desired functionality associated with that feature or characteristic.

[0201] When a single numerical value is given for a characteristic or property, it should be construed as including at least a deviation of that value within one significant digit of the given numerical value.

[0202] When a numerical value or range of numerical values ​​is provided to define a feature or characteristic of an object or operation described herein, whether or not the numerical value or range is modified by a degree term, a specific method of measuring the feature or characteristic may be specified herein as well. If a specific method of measuring the feature or characteristic is not specified herein, and there are different commonly accepted methods of measurement for the feature or characteristic, the method of measurement should be interpreted as the method of measurement that is most likely to be employed by a person of ordinary skill in the art, given the description and context of the feature or characteristic. Furthermore, if there are two or more methods of measurement that are equally likely to be employed by a person of ordinary skill in the art to measure the feature or characteristic, the value or range of values ​​should be interpreted as being satisfied regardless of which method of measurement is selected.

[0203] It will be understood by those of skill in the art that the terms used herein, and particularly in the claims that follow (e.g., the body of the claims that follow), are intended to be "open" terms unless otherwise specified (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.).

[0204] It should be further understood by those skilled in the art that where a particular number of pre-prefaced claim recitations is intended, that intent is expressly recited in the claim and that in the absence of such recitation, no intent exists. For example, as an aid to understanding, the claims hereafter may include the use of the pre-preface terms "at least one" and "one or more" to preface the claim recitations. However, the use of such terms should not be construed as suggesting that the pre-preface of a claim recitation with the indefinite article "a" or "an" limits any particular claim that includes such pre-prefaced claim recitation to an embodiment that includes only such one recitation, even if the same claim includes the pre-preface terms "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"). The same applies to the use of definite articles used to preface the claim recitations. Moreover, even if a particular number of recited elements of a preambled claim is explicitly recited, one of ordinary skill in the art will recognize that such a recitation should normally be interpreted as meaning at least the recited number (e.g., a mere recitation of "two named objects" without other qualification normally means at least two named objects or more than two named objects).

[0205] In instances where conventional analogs to "at least one of A, B, and C" are used, such configurations would include systems having only A, only B, only C, both A and B without C, both A and C without B, both B and C without A, and all of A, B, and C. It should be further understood by those skilled in the art that virtually any disjunction and / or phrase presenting two or more alternative terms, whether in the detailed description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" should be understood to include A without B, B without A, and both A and B.

[0206] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the claims, principles and novel features disclosed herein. The word "exemplary" is used exclusively herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0207] Certain features that are described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Further, although features may be described above as operating in a particular combination and may initially be claimed as such, one or more features from a claimed combination may in some cases be excluded from that combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0208] The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and / or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

Claims

1. 1. A device for temporarily protecting the neck of an aneurysm of an intracranial vessel during treatment of the aneurysm, comprising: one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition in use from the contracted configuration to an expanded configuration that substantially conforms to a shape of an inner surface of the intracranial vessel proximate the aneurysm being treated, the frame configured to transition back to the contracted configuration after the aneurysm has been treated and removed from the intracranial vessel; a covering disposed on at least a portion of the frame, the covering including at least a first portion configured to be positioned against a neck of the aneurysm while the aneurysm is being treated, the first portion of the covering having pores formed therein defining a first porosity thereof; 16. A device comprising:

2. The device of claim 1 , wherein the one or more wires converge and meet at a distal end of the frame.

3. The device of claim 1 , further comprising a retention wire disposed at a proximal end of the frame of the one or more wires.

4. The device of claim 1 , wherein none of the one or more wires converge at a distal end of the frame, thereby providing an unobstructed distal end of the frame.

5. The device of claim 4 , wherein the frame includes a generally circular flow outlet opening at the distal end of the frame.

6. The device of claim 5 , wherein the frame comprises a chamfered flow inlet opening at the proximal end of the frame.

7. The device of claim 1 , wherein the one or more wires is 12 or fewer wires.

8. The device of claim 1 , wherein the frame is configured to self-expand under a bias from a plurality of the wires.

9. The device of claim 1 , wherein the first porosity is configured to support hemostasis within the aneurysm by substantially blocking blood flow to the aneurysm through the first portion of the covering.

10. 10. The device of claim 1, wherein the membrane is configured to retain any intraaneurysmal blood clot within the aneurysm, thereby preventing migration of the clot into the intracranial vessel while the aneurysm is being treated.

11. 10. The device of claim 1, wherein a membrane is configured to redirect a coil introduced into the aneurysm away from the neck of the aneurysm, thereby facilitating effective filling of the aneurysm with the coil.

12. 10. The device of claim 1, wherein a membrane is configured to prevent a coil introduced into the aneurysm from protruding into and / or becoming entangled in the plurality of wires of the frame.

13. 2. The device of claim 1, wherein the first porosity allows fluid to exit the aneurysm through the first portion of the membrane while intrasac volume is displaced by a coil introduced into the aneurysm, and systemic blood pressure maintains the aneurysm in an expanded state while the coil is introduced into the aneurysm.

14. The device of claim 1 , wherein the first porosity substantially blocks radiocontrast agent injected into the intracranial vessels.

15. the first porosity is less than or equal to 10%; The device of claim 1 , wherein the pore size associated with the first porosity is less than about 20 microns.

16. the first porosity is within a range of about 10-40%; The device of claim 1 , wherein the pore size associated with the second porosity is greater than about 100 or 200 microns.

17. 2. The device of claim 1, wherein each of the proximal and distal ends of the frame is substantially open such that the frame is configured to expand while allowing blood to flow freely longitudinally therethrough to supply directly to tissue distal to the aneurysm.

18. The device of claim 1 , wherein the cover is made of a polymer.

19. The device of claim 18 , wherein the cover is electrospun onto the frame.

20. The device of claim 1 , wherein the diameter of the frame in the expanded configuration is less than 10 mm.

21. The device of claim 1 , wherein the diameter of the frame in the expanded configuration is less than 5 mm.

22. 1. A device for temporarily protecting the neck of an aneurysm of an intracranial vessel during treatment of the aneurysm, comprising: one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition in use from the contracted configuration to an expanded configuration that substantially conforms to a shape of an inner surface of the intracranial vessel proximate the aneurysm being treated, the frame configured to transition back to the contracted configuration after the aneurysm has been treated and removed from the intracranial vessel; an electrospun covering disposed on at least a portion of the frame, the covering comprising at least a first portion configured to be positioned against a neck of the aneurysm while the aneurysm is being treated, the first portion of the covering having pores formed therein defining a first porosity thereof; Equipped with said first porosity is less than or equal to 0.2, a pore size associated with said first porosity is less than about 10 microns, and the product of said first porosity and median pore size in microns is between 0.1 and 2.

23. 23. The device of claim 22, wherein the covering prevents the inflow of radiocontrast media into the aneurysm sac.

24. 1. A method of treating an intracranial aneurysm, comprising: inserting a first microcatheter through an intracranial vessel and at least partially into the intracranial aneurysm; threading a guidewire through the intracranial vessel to a location outside the neck of the aneurysm while the first microcatheter is positioned within the intracranial vessel; threading a second microcatheter over the guidewire and through the intracranial vessel to a location outside the neck of the aneurysm; threading a device for temporarily protecting the neck of the aneurysm through the second microcatheter in a contracted state and out of the distal end of the second microcatheter, the device for temporarily protecting the neck of the aneurysm comprising one or more wires forming a contractible frame having a covering on at least a portion thereof with pores defining a first porosity; expanding the device to a deployed configuration that substantially conforms to a shape of an interior surface of the intracranial vessel proximate the aneurysm, with the cover defining a first porosity positioned against the neck of the aneurysm; placing at least one coil through the first microcatheter and into the aneurysm; removing the device from the intracranial vessel; A method for providing the above.

25. 25. The method of claim 24, comprising utilizing a membrane to retain an intra-aneurysmal clot within the aneurysm, thereby preventing migration of the clot into the blood vessel while the aneurysm is being treated.

26. 25. The method of claim 24, comprising injecting a radiopaque contrast agent into the intracranial vessels and substantially preventing the radiopaque contrast agent from entering the aneurysm sac.

27. 25. The method of claim 24, comprising utilizing the membrane to prevent the at least one coil from protruding into and / or becoming entangled in the plurality of wires of the frame.

28. 25. The method of claim 24, wherein the intracranial vessel has a diameter of less than 5 mm.

29. 29. The method of claim 28, wherein the intracranial vessel is selected from the internal carotid artery, the communicating artery, or the middle cerebral artery.

30. 1. An intravascular flow diverter for treating an aneurysm of an intracranial vessel, comprising: one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition, in use, from the contracted configuration to an deployed configuration that substantially conforms to a shape of an interior surface of the intracranial vessel proximate the aneurysm; an electrospun cover disposed on at least a portion of the frame, a first portion configured to be positioned against the neck of the aneurysm, the first portion of the covering having pores formed therein defining a first porosity thereof; and a second portion having a second porosity to blood flow greater than the first porosity, the second portion configured to be positioned adjacent to but not directly over the aneurysm; The cover comprising: An intravascular flow diverter comprising:

31. 31. The intravascular flow diverter of claim 30, wherein the one or more wires are configured to self-expand under a bias from a plurality of the wires.

32. 31. The intravascular flow diverter of claim 30, wherein the one or more wires are configured to expand under the influence of a balloon configured to be expanded from within the frame.

33. 31. The intravascular flow diverter of claim 30, configured to be disposed within a microcatheter configured to be threaded through the intracranial blood vessel to the location of the aneurysm, in a contracted configuration.

34. 31. The intravascular flow diverter of claim 30, wherein the second portion is configured to be placed directly over a side branch of the blood vessel.

35. 31. The intravascular flow diverter of claim 30, wherein the first porosity is sufficiently low such that when the intravascular flow diverter is properly positioned within the blood vessel, the first portion of the membrane is configured to substantially not allow blood flow therethrough, causing a blood clot to form and ultimately scar over the aneurysm.

36. 31. The intravascular flow diverter of claim 30, wherein the second porosity is sufficiently high such that when the intravascular flow diverter is positioned within the blood vessel, the second portion of the covering is configured to permit blood flow therethrough directly into a side branch of the blood vessel.

37. 31. The intravascular flow diverter of claim 30, wherein each of the plurality of wires has a diameter of one of about 0.002 inches, about 0.015 inches, and about 0.001 inches.

38. 31. The intravascular flow diverter of claim 30, wherein the expandable structure of the stent is configured to have a minimum outer diameter of one of about 0.011 inches, about 0.008 inches, and about 0.006 inches when fully contracted.

39. 31. The intravascular flow diverter of claim 30, wherein the expandable structure of the stent is configured to have a maximum outer diameter of about 0.18 inches when fully expanded.

40. 31. The intravascular flow diverter of claim 30, wherein a substantial majority of the combined porosity of the first and second portions of the membrane of the intravascular flow diverter is derived from the first and second porosities of the membrane in the first and second portions, respectively.

41. 31. The intravascular flow diverter of claim 30, wherein each of the plurality of wires is comprised of at least one of superelastic nitinol, cobalt chromium, and nitinol shape memory alloy.

42. 1. An intravascular flow diverter for treating an aneurysm of an intracranial vessel, comprising: one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition, in use, from the contracted configuration to an deployed configuration that substantially conforms to a shape of an interior surface of the intracranial vessel proximate the aneurysm; an electrospun cover disposed on at least a portion of the frame, a first portion configured to be positioned against the neck of the aneurysm, the first portion of the covering having pores formed therein defining a first porosity thereof; a second portion distal to the first portion, the second portion having a second porosity to blood flow greater than the first porosity, the second portion configured to be positioned adjacent to but not directly over the aneurysm; and a third portion proximal to the first portion, the third portion having a third porosity to blood flow greater than the first porosity, the third portion configured to be positioned adjacent to but not directly over the aneurysm; The cover comprising: Equipped with 1. An intravascular flow diverter, wherein each of the one or more wires has a diameter of less than 0.02 inches, a frame porosity over substantially the entire length of the frame is 93% or greater in an expanded frame configuration, the first porosity is less than 0.05, and each of the second porosity and the third porosity is greater than 0.

05.

43. 43. The intravascular flow diverter of claim 42, wherein each of the second porosity and the third porosity is less than 0.

4.

44. 43. The intravascular flow diverter of claim 42, wherein the expandable structure comprises each of the one or more wires wound in a generally helical shape.

45. 45. The intravascular flow diverter of claim 44, wherein each of the one or more wires comprises a plurality of helical loops, each having a predetermined pitch.

46. 46. ​​The intravascular flow diverter of claim 45, wherein a first subset of the one or more wires are wound in a clockwise direction and a second subset of the wires are wound in a counterclockwise direction.

47. 47. The intravascular flow diverter of claim 46, wherein each wire of the one or more wires is offset from at least one adjacent one of the plurality of wires by a predetermined interval.

48. 43. The intravascular flow diverter of claim 42, wherein the one or more wires are one of 6 wires, 8 wires, 12 wires, and 16 wires.

49. 43. The intravascular flow diverter of claim 42, wherein each of the plurality of wires has a diameter of approximately one of 0.015 inches and 0.001 inches.

50. 43. The intravascular flow diverter of claim 42, wherein the expandable structure of the stent, when fully contracted, has a minimum outer diameter of one of about 0.011 inches, about 0.008 inches, and about 0.006 inches.

51. 43. The intravascular flow diverter of claim 42, wherein the expandable structure of the stent has a maximum outer diameter of about 0.18 inches when fully expanded.

52. 43. The intravascular flow diverter of claim 42, wherein a substantial majority of the combined porosity of the first and second portions of the membrane of the intravascular flow diverter is derived from the first and second porosities of the membrane in the first and second portions, respectively.

53. 43. The intravascular flow diverter of claim 42, wherein each of the plurality of wires is comprised of at least one of superelastic nitinol, cobalt chromium, and nitinol shape memory alloy.

54. 1. A method of using an intravascular flow diverter to treat an aneurysm of an intracranial vessel, comprising: placing the intravascular flow diverter within a microcatheter; threading the microcatheter through the intracranial vessel to the location of the aneurysm; The endovascular flow diverter stent comprises a plurality of wires coiled to form an expandable structure, a first portion of an electrospun covering disposed over an outer surface of the stent is positioned directly against the neck of the aneurysm, the first portion having a first porosity to blood flow; At least one second portion of the membrane is positioned adjacent to but not directly over the aneurysm, the at least one second portion having a second porosity to blood flow that is greater than the first porosity. removing the intravascular flow diverter from the distal end of the microcatheter so as to sufficiently expand within the intracranial vessel; The method includes:

55. 55. The method of claim 54, comprising expanding the intravascular flow diverter under bias from the plurality of wires when the intravascular flow diverter is removed from the microcatheter.

56. 55. The method of claim 54, comprising expanding the plurality of wires by expanding a balloon from within a generally helical configuration.

57. 55. The method of claim 54, wherein threading the microcatheter through the intracranial vessel to the location of the aneurysm comprises positioning at least one of the at least one second portion directly over a side branch of the vessel.

58. 55. The method of claim 54, wherein the first porosity is sufficiently low such that when the intravascular flow diverter is properly positioned within the intracranial blood vessel, the first portion of the membrane is configured to substantially not allow blood flow therethrough, thereby causing a blood clot to form and ultimately scar over the aneurysm.

59. 55. The method of claim 54, wherein the second porosity is sufficiently high such that at least one of the at least one second portion of the membrane is configured to allow substantial blood flow therethrough directly into a side branch of the intracranial blood vessel when the intravascular flow diverter is properly positioned within the vessel.

60. 1. An intrasaccular flow diverter for treating an aneurysm of an intracranial vessel, comprising: one or more wires forming a frame, the frame having a contracted configuration and an expanded configuration, the frame configured to transition, in use, from the contracted configuration to a deployed configuration that substantially conforms to a shape of an inner surface of a sac of the aneurysm; an electrospun cover disposed on at least a portion of the frame, a first portion configured to be positioned against the neck of the aneurysm, the first portion of the covering having pores formed therein that define a first porosity thereof; and a second portion having a second porosity to blood flow greater than the first porosity, the second portion configured to be positioned within the sac of the aneurysm distal to the neck of the aneurysm. The cover comprising: An intracapsular flow diverter comprising:

61. 61. The intracapsular flow diverter of claim 60, wherein the frame comprises each of the one or more wires wound in a generally helical shape.

62. 62. The intracapsular flow diverter of claim 61, wherein the plurality of helical loops have diameters that continuously increase and then decrease, thereby forming a generally spherical structure.

63. 61. The intracapsular flow diverter of claim 60, wherein the plurality of wires is one of 8 wires, 12 wires, and 16 wires.

64. 61. The intracapsular flow diverter of claim 60, wherein the one or more wires are configured to self-expand under a bias from the one or more wires.

65. 61. The intrasaccular flow diverter of claim 60, configured to be disposed within a microcatheter configured to be threaded through the blood vessel to a location within the aneurysm, in a contracted configuration.

66. 61. The intracapsular flow diverter of claim 60, wherein the first porosity is less than 0.

05.

67. 61. The intracapsular flow diverter of claim 60, wherein the second porosity is greater than 0.

05.

68. 61. The intracapsular flow diverter of claim 60, wherein each of the plurality of wires has a diameter of about one of 0.0003 inches, about 0.0005 inches, 0.0007 inches, and 0.001 inches.

69. 61. The intracapsular flow diverter of claim 60, wherein the generally spherical structure is configured to have a minimum outer diameter of one of about 0.002 inches, about 0.003 inches, about 0.004 inches, and about 0.006 inches when fully contracted.

70. 61. The intracapsular flow diverter of claim 60, wherein the generally spherical structure is configured to have a maximum outer diameter of about 0.18 inches when fully expanded.

71. 61. The intra-sac flow diverter of claim 60, wherein a substantial majority of the combined porosity of the membrane in the first and second portions of the intra-sac flow diverter is derived from the first and second porosities of the membrane in the first and second portions, respectively.

72. 61. The intracapsular flow diverter of claim 60, wherein each of the one or more wires is comprised of superelastic Nitinol.

73. 61. The intrasaccular flow diverter of claim 60, wherein the membrane is made of a polymer.

74. 1. A method of utilizing an intrasaccular flow diverter to treat a vascular aneurysm, comprising: placing the intrasaccular flow diverter in a deflated state within a microcatheter; threading the microcatheter through the blood vessel to a location within the aneurysm; a plurality of coiled wires forming a contracted generally spherical frame of the intracapsular flow diverter; a first portion of the membrane disposed on at least a portion of an exterior surface of the generally spherical frame is positioned directly against the neck of the aneurysm, the first portion having a first porosity to blood flow; A second portion of the membrane is disposed within the aneurysm and distal to the neck of the aneurysm, the second portion having a second porosity to blood flow that is greater than the first porosity. removing the intrasaccular flow diverter from the distal end of the microcatheter so as to sufficiently expand within the aneurysm; and The method includes:

75. 75. The method of claim 74, wherein the plurality of wires is configured to self-expand under a bias from the plurality of wires.

76. 75. The method of claim 74, wherein the first porosity is less than 0.

05.

77. 75. The method of claim 74, wherein the second porosity is between 0.05 and 0.4.

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