Cerebral dural sinus stent

Abstract

The implantable device includes a tubular member defining a longitudinal axis and a lumen. The tubular member includes a plurality of filaments defining a plurality of openings therebetween, a distal end portion having a distal diameter, a proximal end portion having a proximal diameter greater than the distal diameter, and an intermediate portion having an intermediate diameter smaller than the distal diameter. In one embodiment, the proximal diameter is about 10 mm to about 14 mm, the distal diameter is about 4 mm to about 8 mm, and the intermediate diameter is about 4 mm to about 7 mm.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 984,549, filed March 3, 2020. The entire disclosure of the aforementioned application is incorporated herein by reference. [Background technology]

[0002] Idiopathic intracranial hypertension (IIH) is a common disorder afflicting young overweight women in which elevated intracranial pressure can lead to blindness and cognitive decline, and severe symptoms of headaches and pulsatile tinnitus (PT). Dural sinus stenting is an emerging therapy for IIH and PT patients with venous sinus stenosis. To be eligible for therapy, intravenous pressure measurements must be performed and a sufficient pressure gradient across the stenosis must be measured (typically above 5 or 8 mmHg) in patients with little or no sedation. However, placement of currently available stents designed for either carotid or peripheral venous applications is very tricky for the operator and painful for the patient due to the stiffness and high radial forces of the carotid stent. Thus, stent procedures typically require general anesthesia to be performed safely. The high radial forces exerted by carotid stents can also cause severe headaches in patients, which can sometimes only be treated with steroids. Steroids in IIH patients are very dangerous as withdrawal of steroids may in itself worsen the underlying IIH pathology.

[0003] Currently available stents, such as typical carotid stents, also do not come in suitable lengths or configurations to treat IIH. In particular, carotid stents do not come in long enough configurations, do not have suitable diameters, and are primarily round in shape. In response, many operators use multiple stent configurations that vary widely in size. This exposes patients to increased procedural risks (risk of potentially mismatching the stent or sizing it too short), which can lead to stent migration (if a stent that is too small is used), or headaches (if a stent that is too large is used).

[0004] In addition, many patients with PT have a venous sinus stenosis that is the source of their PT. However, many sinus stenoses are asymptomatic. The only currently available stents to treat transverse sinus stenosis are permanent implants that must be placed in patients under general anesthesia. A stent that can be safely and painlessly placed while the patient is awake would allow the patient to report immediately upon stent deployment whether their symptoms have improved. In patients whose symptoms are worsened or do not improve with stent placement, current technology does not allow for removal of the stent.

[0005] In addition, many patients treated with currently available stents have to undergo revision surgery to durably treat venous pulmonary hypertension and IIH due to failure of the initial stent placement procedure. This may be in part because the carotid stents utilized have too high a radial force and are circular. These stents decompress the dural venous sinuses to a point where normal fluctuations in intracranial pressure can cause dural venous sinuses not treated with a stent to collapse. In other words, the venous sinuses are unable to withstand normal transient spikes in intracranial pressure. The ability of the venous sinuses to withstand compression from intracranial pressure is a combination of the pressure within the vein and the inherent resistance of the sinuses. By placing a stent with a very high resistance in the dural venous sinuses, the venous system does not have the capacity to withstand normal transient spikes in intracranial pressure, and therefore IIH recurs in many patients treated with venous sinus stent placement.

[0006] Therefore, a need exists for improved treatment methods and devices that address the shortcomings of conventional stents. Summary of the Invention [Means for solving the problem]

[0007] The present disclosure provides a stent that is constructed and designed for the unique environment of the dural sinuses, particularly the sigmoid and sinus intersections of the cerebral dural veins. The stent can be tapered and include a flexible proximal tip that can easily and nearly painlessly traverse sinuses and stenoses. The disclosed stent has a resistance of approximately 0.1 Newtons per square millimeter (approximately 0.1 N / mm 2 ) ~ approx. 0.2N / mm 2 The radial force is sufficiently low to open possible sinus stenosis.

[0008] As used herein, the term "distal" refers to the portion of the implanted device that is further from the heart, while the term "proximal" refers to the portion that is closer to the heart. Thus, with respect to blood flow through a vein, blood flows from the distal end to the proximal end. Thus, the proximal portion may be positioned adjacent to the sigmoid sinus and the distal portion may be positioned adjacent to the sinus intersection after implantation.

[0009] As used herein, the terms "biodegradable" and "bioresorbable" are used in reference to the properties of materials. "Biodegradable" is a material that can be decayed or broken down in the body and then excreted. "Bioresorbable" is a material that can be decayed or broken down in the body and then resorbed. Both biodegradable and bioresorbable materials are suitable for the purposes of this application, and therefore, for simplicity, unless otherwise indicated, biodegradable and bioresorbable materials are collectively referred to herein as "biodegradable". Conversely, "non-biodegradable" is a biocompatible (i.e., not harmful to living tissue) material that does not decay or break down in the body. In addition, the term "dissolution" used in the description refers to the degradation of both biodegradable and bioresorbable materials.

[0010] The radial force of the stent is such that it is larger when the stent is collapsed and smaller when the stent is expanded. Such a design allows the stent to temporarily narrow to a point due to normal transient increases in intracranial pressure, but then to withstand further compression. By contracting in response to elevated intracranial pressure (ICP), the stent will cause temporary venous pulmonary hypertension to withstand the collapse of untreated dural venous sinuses during transient changes in ICP. Once the transient ICP rise resolves, i.e., ICP decreases, the stent will expand again. Due to high radial forces (or high crush resistance), conventional stents do not change their expanded size in response to changes in ICP. As a result, conventional stents can expand the vessel beyond its natural diameter, resulting in a wider section. At the junction of the unstented and stented sections of the vessel, blood flow can result in heavy blood flow and a resulting pressure drop. Thus, conventional stents may fail at the juncture.

[0011] A stent according to the present disclosure may have any suitable cross-section, e.g., elliptical, circular, triangular, rectangular, polygonal, etc., to suit the geometry of the vessel, i.e., the dural sinus. The stent may have a length of about 30 mm to about 200 mm and may be tapered from a proximal portion (i.e., larger diameter) to a distal portion (i.e., smaller diameter). The proximal diameter may be about 8 mm to about 14 mm, and the distal diameter may be about 4 mm to about 8 mm. After implantation, the proximal portion may be positioned adjacent to or within the sigmoid sinus. The distal portion may be positioned adjacent to the sinus intersection or within the superior sagittal sinus. The tapered portion minimizes changes in the shape and cross-sectional area of ​​the vessel, limiting the occurrence of turbulent flow.

[0012] A secondary stent may also be used to treat the unique anatomical considerations of the posterior third of the superior sagittal sinus. It may be about 4 mm to about 5 mm in diameter throughout its length and may have the ability to flare wider to accommodate the sinus intersection. It may also be tapered from about 3 mm distally to about 6 mm proximally. It may be tapered to be of a cross-sectional area similar to the natural sinus. It may therefore have a flare to a wider diameter to accommodate the sinus intersection. The secondary stent may be about 60 to 100 mm in length.

[0013] The stent may have a closed cell or braided design, allowing the stent to be retrievable, as such a structure allows for reversible expansion and collapse of the stent. In embodiments, the stent may have an open cell design to minimize radial forces. In embodiments, the stent may be mounted on a wire to facilitate retrievability. In further embodiments, the stent may have a hook arrangement on the side of the stent proximal to the jugular vein to allow the operator to retrieve the stent. Pulling on the hook adjusts the size and shape of the stent, i.e., changes the shape of the taper. The hook also allows the stent to be recaptured by a catheter with a corresponding hook. The stent may be formed from a biodegradable material such that the stent dissolves after a period of time, i.e., when the stent has "healed" into place. The stent may be formed from a degradable material such that an agent, or chemical, or other material that dissolves or degrades the stent after a period of time can be injected into, adjacent to, or systemically.

[0014] The disclosed stents can be used in safer, less painful, and more durable treatments for IIH and PT. IIH affects 20 out of 100,000 overweight women of childbearing age. As the obesity epidemic grows, this patient population is expected to continue to expand. A large proportion of these patients can be successfully treated with a venous sinus stent according to the present disclosure. Alternative conventional therapies have significant limitations, including poor safety records, high revision therapy rates, or difficulty in patient tolerance. PT afflicts 3-5 million Americans and has a very high comorbidity association with depression, anxiety, and even suicidal ideation. Effective conventional treatments for PT are few and far between.

[0015] According to one embodiment of the present disclosure, an implantable device is disclosed that includes a tubular member defining a longitudinal axis and a lumen, the tubular member including a plurality of filaments defining a plurality of openings therebetween, a distal end portion having a distal diameter, a proximal end portion having a proximal diameter greater than the distal diameter, and an intermediate portion having an intermediate diameter less than the distal diameter.

[0016] According to one aspect of the above embodiment, the proximal diameter is about 10 mm to about 14 mm. The distal diameter is about 4 mm to about 8 mm. The intermediate diameter is about 4 mm to about 7 mm. The proximal diameter may be about 2 to about 3 times larger than the distal diameter.

[0017] According to another aspect of the above embodiment, the implantable device further includes an attachment member including a plurality of attachment filaments and a hook coupled to the attachment filaments. Rotation of the attachment member about the longitudinal axis in a first direction expands the tubular member and rotation in a second direction opposite the first direction constrains the tubular member. The tubular member is formed from a non-biodegradable material and the attachment member is formed from a biodegradable material.

[0018] According to another aspect of the above embodiment, the implantable device further includes a wire disposed within and through the lumen, which may be parallel to the longitudinal axis, the wire being coupled to the tubular member. The tubular member is formed from a non-biodegradable material and the wire is formed from a biodegradable material. According to a further aspect of the above embodiment, the tubular member is formed from a biodegradable material.

[0019] According to a further embodiment of the present disclosure, a method of treating a cerebral dural venous sinus is disclosed. The method includes inserting an implantable device into the cerebral dural venous sinus. The implantable device includes a tubular member defining a longitudinal axis and a lumen. The tubular member includes a plurality of filaments defining a plurality of openings therebetween, a distal end portion having a distal diameter, a proximal end portion having a proximal diameter greater than the distal diameter, and an intermediate portion having an intermediate diameter less than the distal diameter.

[0020] According to one aspect of the above embodiment, the proximal end portion is positioned adjacent to a sigmoid sinus of the cerebral dural sinuses. The distal end portion is positioned adjacent to a sinus intersection of the cerebral dural sinuses. The stent can also be sufficiently long such that the distal end of the portion is positioned within the superior sagittal sinus.

[0021] In accordance with another aspect of the above embodiment, the implantable device further includes an attachment member including a plurality of attachment filaments and a hook coupled to the attachment filaments. The method also includes rotating the attachment member about the longitudinal axis in a first direction to expand the tubular member. The method further includes rotating the attachment member about the longitudinal axis in a second direction opposite the first direction to constrain the tubular member.

[0022] According to further aspects of the above embodiment, the tubular member is formed from a non-biodegradable material and the attachment member is formed from a biodegradable material, and the method further includes injecting a reagent into the cerebral dural sinus to dissolve at least a portion of the attachment member.

[0023] According to yet another aspect of the above embodiment, the proximal diameter is from about 10 mm to about 14 mm, the distal diameter is from about 4 mm to about 8 mm, and the intermediate diameter is from about 4 mm to about 7 mm.

[0024] According to a further embodiment of the present disclosure, an implantable device is disclosed. The implantable device includes a plurality of tubular members arranged parallel to each other and defining a longitudinal axis and a lumen. Each of the tubular members has a crush resistance equal to an intracranial pressure threshold such that each of the tubular members is configured to collapse in response to intracranial pressure rising above the threshold and expand in response to intracranial pressure falling below the threshold. In other words, each of the tubular members has a different threshold pressure at which it collapses. Some collapse at high normal physiological range of ICP. Some collapse at very high ICP and some are essentially open all the time.

[0025] According to yet another embodiment of the present disclosure, an implantable device is disclosed. The implantable device includes a first expandable tubular member having a crush resistance equal to a first intracranial pressure threshold such that the first expandable tubular member is configured to collapse in response to intracranial pressure rising above the first intracranial pressure threshold and expand in response to intracranial pressure falling below the first intracranial pressure threshold. The implantable device further includes a second expandable tubular member in contact with and disposed parallel to the second expandable tubular member, the second expandable tubular member having a crush resistance equal to the second intracranial pressure threshold such that the second expandable tubular member is configured to collapse in response to intracranial pressure rising above the second intracranial pressure threshold and expand in response to intracranial pressure falling below the second intracranial pressure threshold.

[0026] According to one aspect of the above embodiment, the first intracranial pressure threshold and the second intracranial pressure threshold are different. The present invention further provides, for example, the following: (Item 1) 14. An implantable device comprising: a tubular member defining a longitudinal axis and a lumen, the tubular member comprising: a plurality of filaments, the plurality of filaments defining a plurality of openings therebetween; a distal end portion having a distal diameter; a proximal end portion having a proximal diameter greater than the distal diameter; an intermediate portion having an intermediate diameter smaller than the distal diameter; 13. An implantable device comprising: (Item 2) 2. The implantable device of item 1, wherein the proximal diameter is about 10 mm to about 14 mm, the distal diameter is about 4 mm to about 8 mm, and the intermediate diameter is about 4 mm to about 7 mm. (Item 3) 2. The implantable device of claim 1, wherein the proximal diameter is about 2 to about 3 times larger than the distal diameter. (Item 4) Item 14. The implantable device of item 1, further comprising an attachment member including a plurality of attachment filaments and hooks coupled to the attachment filaments. (Item 5) 5. The implantable device of claim 4, wherein rotation of the attachment member about the longitudinal axis in a first direction expands the tubular member and rotation in a second direction opposite the first direction constrains the tubular member. (Item 6) 5. The implantable device of claim 4, wherein the tubular member is formed from a non-biodegradable material and the attachment member is formed from a biodegradable material. (Item 7) 2. The implantable device of claim 1, further comprising a wire disposed through the lumen and coupled to the tubular member. (Item 8) 8. The implantable device of claim 7, wherein the tubular member is formed from a non-biodegradable material and the wire is formed from a biodegradable material. (Item 9) Item 14. The implantable device of item 1, wherein the tubular member is formed from a biodegradable material. (Item 10) 1. A method for treating a cerebral dural venous sinus, the method comprising: 1. Folding an implantable device into a folded configuration, the implantable device including a tubular member defining a longitudinal axis and a lumen, the tubular member comprising: a plurality of filaments, the plurality of filaments defining a plurality of openings therebetween; a distal end portion having a distal diameter; a proximal end portion having a proximal diameter greater than the distal diameter; an intermediate portion having an intermediate diameter smaller than the distal diameter; and inserting the implantable device into the cerebral dural sinus; Expanding the implantable device inside the cerebral dural sinus to an expandable configuration. A method comprising: (Item 11) 11. The method of claim 10, further comprising placing the implantable device within the dural venous sinus such that the proximal end portion is positioned adjacent to a sigmoid sinus of the cerebral dural venous sinus and the distal end portion is positioned adjacent to a sinus intersection of the cerebral dural venous sinus. (Item 12) 11. The method of claim 10, wherein the implantable device further comprises an attachment member including a plurality of attachment filaments and hooks coupled to the attachment filaments. (Item 13) Item 13. The method of item 12, further comprising rotating the attachment member about the longitudinal axis in a first direction to expand the tubular member. (Item 14) Item 14. The method of item 13, further comprising rotating the attachment member about the longitudinal axis in a second direction opposite the first direction to constrain the tubular member. (Item 15) Item 13. The method of item 12, wherein the tubular member is formed from a non-biodegradable material and the attachment member is formed from a biodegradable material. (Item 16) 16. The method of claim 15, further comprising injecting a reagent into the cerebral dural sinus to dissolve at least a portion of the attachment member. (Item 17) Item 11. The method according to item 10, wherein the proximal diameter is about 10 mm to about 14 mm, the distal diameter is about 4 mm to about 8 mm, and the intermediate diameter is about 4 mm to about 7 mm. (Item 18) 1. An implantable device comprising: The implantable device comprises a plurality of tubular members arranged parallel to one another and defining a longitudinal axis and a lumen, each of the tubular members having a crush resistance equal to an intracranial pressure threshold, whereby each of the tubular members is configured to collapse in response to intracranial pressure rising above the threshold and to expand in response to the intracranial pressure falling below the threshold. (Item 19) 1. An implantable device, comprising: a first expandable tubular member having a crush resistance equal to a first intracranial pressure threshold, whereby the first expandable tubular member is configured to collapse in response to intracranial pressure rising above the first intracranial pressure threshold and to expand in response to the intracranial pressure falling below the first intracranial pressure threshold; a second expandable tubular member disposed in contact with and parallel to the first expandable tubular member; Equipped with An implantable device, wherein the second expandable tubular member has a crush resistance equal to a second intracranial pressure threshold, whereby the second expandable tubular member is configured to collapse in response to intracranial pressure rising above the second intracranial pressure threshold and to expand in response to the intracranial pressure falling below the second intracranial pressure threshold. (Item 20) 20. The implantable device of claim 19, wherein the first intracranial pressure threshold and the second intracranial pressure threshold are different. [Brief description of the drawings]

[0027] Embodiments of the present disclosure are described herein with reference to the accompanying drawings.

[0028] [Figure 1] FIG. 1 is a perspective view of an implantable device according to one embodiment of the present disclosure.

[0029] [Diagram 2] FIG. 2 is a perspective view of an implantable device according to another embodiment of the present disclosure.

[0030] [Diagram 3] FIG. 3 is a perspective view of an implantable device according to a further embodiment of the present disclosure.

[0031] [Figure 4] 4 is a perspective view of a mounting member of the implantable device of FIG. 1 according to one embodiment of the present disclosure.

[0032] [Diagram 5] FIG. 5 is a perspective view of an implantable device according to a further embodiment of the present disclosure.

[0033] [Figure 6] FIG. 6 is a perspective view of an implantable device according to yet another embodiment of the present disclosure.

[0034] [Figure 7] FIG. 7 is a perspective view of an implantable device according to a further embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Embodiments of the present disclosure will now be described in detail with reference to the drawings, in which like reference numerals designate the same or corresponding elements in each of the several views.

[0036] The present disclosure provides a method of treating IIH and PT by inserting a catheter into the cerebral venous sinus and implanting a device. Suitable implantable devices according to the present disclosure can be self-expanding or balloon-expandable stents with various outer wall diameters.

[0037] The implantable device may be constrained within a catheter and, upon release at a target location within a target vein or any other vascular location, self-expand to contact and press against the vessel wall, preventing migration of the device. In embodiments, the device may include one or more attachment members, such as hooks, anchors, or teeth, for fitting the device into the vein wall. The outer wall of the implantable device is sufficiently permeable so as not to impede venous access from the cortical or internal jugular veins into the larger sinuses. Thus, the device is minimally thrombogenic to minimize the risk of embolism to the systemic venous circulation and the entire pulmonary arterial system, as thrombogenicity may result in parent sinus occlusion.

[0038] 1-3, an implantable device 2, e.g., a stent, in accordance with the present disclosure includes a tubular member 10 defining a longitudinal axis "AA" and a lumen 12 extending along the longitudinal axis "AA." The tubular member 10 includes a distal end portion 14 and a proximal end portion 16. The tubular member 10 includes a plurality of interconnected filaments 17 that define a plurality of openings 19 between the interconnected filaments 17. The tubular member 10 is configured to contact a wall of a vessel, such as a dural venous sinus.

[0039] Following implantation, the distal end portion 14 may be positioned adjacent the sinus intersection and the proximal end portion 16 may be positioned adjacent the sigmoid sinus after implantation. The tubular member 10 may have any suitable cross-sectional shape to match the natural shape of the blood vessel, such as oval, circular, polygonal (i.e., triangular or rectangular), etc. As shown in FIG. 2, the tubular member 10 may have a triangular cross-section, which more closely approximates certain vascular shapes than a circular tubular member 10. As described above, the mismatch in geometry between the stent and the blood vessel may result in turbulent flow.

[0040] In further embodiments, the proximal end portion 16 may have a proximal cross-sectional shape while the distal end portion 14 may have a distal cross-sectional shape different from the first cross-sectional shape to allow for a better fit. The proximal cross-sectional shape may be triangular and the distal cross-sectional shape may be rectangular, oval, or circular to better fit within the sigmoid sinus.

[0041] The radial force of the tubular member 10 may be characterized as the crush resistance, i.e., the force required to collapse the tubular member 10, and the persistent radially outward force, i.e., the persistent pressure exerted by the tubular member 10 when in a nominal state (i.e., expanded configuration). At the nominal state, the radial force may be from about 0 mmHg to about 100 mmHg, and in embodiments, the radial force may be from about 10 mmHg to about 30 mmHg. The persistent radially outward force at the nominal state may be from about 0 mmHg to about 30 mmHg, and in embodiments, may be from about 0 mmHg to about 10 mmHg. The radial force at approximately 30% of the nominal state may be from about 20 mmHg to about 70 mmHg, and in embodiments, may be from about 30 mmHg to about 50 mmHg. The sustained radially outward force at approximately 30% nominal may be about 15 mmHg to about 70 mmHg, and in embodiments, about 20 mmHg to about 50 mmHg. The radial force when the tubular member 10 is fully constrained may be about 30 mmHg to about 200 mmHg, and in embodiments, about 40 mmHg to about 60 mmHg. The radial force when the tubular member 10 is expanded is sufficient to withstand intracranial pressure fluctuations and minimize the risk of migration, yet low enough that the nominal radial force does not cause dural inflammation.

[0042] The tubular member 10 may have a length of about 30 mm to about 200 mm. The tubular member 10 may have a tapered shape as shown in FIG. 3 such that a proximal diameter d1 of the proximal end portion 16 is larger than a distal diameter d2 of the distal end portion 14. The proximal diameter d1 may be about 10 mm to about 14 mm, and the distal diameter d2 may be about 4 mm to about 8 mm. In an embodiment, the proximal diameter d1 may be about 2 to about 3 times larger than the distal diameter d2.

[0043] As shown in FIG. 1, the tubular member 10 may have an hourglass shape with a middle portion 15 with a middle diameter d3 smaller than the distal diameter d2 and the proximal diameter d1. The flared design of the hourglass shape also allows the tubular member 10 to withstand intracranial pressure fluctuations and minimize the risk of migration. The middle diameter d3 may be about 4 mm to about 7 mm. With reference to FIG. 2, if the cross-sectional shape of the tubular member 10 is not circular, tapering may be achieved by reducing the width or other cross-sectional dimension to form a tapered portion (i.e., distal end portion 14).

[0044] Referring to FIG. 4, tubular member 10 may include an optional attachment member 20 coupled thereto. Attachment member 20 may include an optional loop 21 coupled to one or more attachment filaments 22. Loop 21 and / or attachment filament 22 may be continuous with filament 17, woven, braided, or otherwise coupled to tubular member 10 (FIG. 4). In an embodiment, attachment filament 22 may be coupled to hook 24. Loop 21 may be coupled to an intermediate location of tubular member 10 such that loop 21 is adjacent intermediate diameter d3. Pulling attachment filament 22 with hook 24 and / or rotating it modifies the shape of tubular member 10 by adjusting the size of intermediate diameter d3. In an embodiment, rotating attachment filament 22 in either direction about longitudinal axis "AA" via hook 24. Thus, rotating in a first (e.g., clockwise) direction a expands tubular member 10, increasing mid-diameter d3, and rotating in a second (e.g., counterclockwise) direction b constrains tubular member 10, decreasing mid-diameter d3. This would allow for more patient-specific sizing of tubular member 10, adjusting radial force, and potential removal. In a further embodiment, hook 24 allows an external device, such as a recapture catheter (not shown), to attach to tubular member 10 for removal of tubular member 10.

[0045] 5, tubular member 10 may be connected to wire 30 via attachment filament 22. Wire 30 may be disposed within and through lumen 12 and parallel to longitudinal axis "AA." Wire 30 may be used to expand tubular member 10 by rotation or to restrain it in a manner similar to hook 24. Thereby, after implantation, the intermediate diameter d3 of the tubular member 10 can be adjusted. The tubular member 10 can also include a tapered proximal cone 26 coupled to the proximal end portion 16 that is disposed over the attachment filament 22. The shape of the tapered proximal cone 26 provides for easy and substantially painless traversal of venous sinuses and stenoses.

[0046] Because various blood vessels have different blood flow parameters and characteristics, it may be useful to adjust the intermediate diameter d3 of the tubular member 10 according to the blood flow characteristics using the attachment filaments 22, hooks 24, and / or wires 30. The tubular member 10 of Figures 1-5 may also include a number of attachment members, such as hooks, anchors, teeth, or other structures configured to grip the wall of the blood vessel so that the tubular member 10 is secured within the vessel and minimize movement of the tubular member 10 after implantation.

[0047] In embodiments, the attachment filaments 22, hooks 24, and / or wires 30 may be removably coupled to the tubular member 10 by using a release mechanism that may be mechanical, electrolytic, or chemical. In embodiments, the tubular member 10 may be formed from a non-biodegradable material and the attachment filaments 22, hooks 24, and / or wires 30. With respect to a chemical release mechanism, a reagent may be injected either systemically intravenously or locally via a catheter positioned in the venous system "upstream" from the tubular member 10 to dissolve the attachment points coupling the attachment filaments 22, hooks 24, and / or wires 30 to the tubular member 10. In further embodiments, the attachment filaments 22, hooks 24, wires 30, and tubular member 10 may be formed from a biodegradable material whose dissolution may be accelerated by the injected reagent to dissolve some or all of the attachment filaments 22, hooks 24, wires 30, and / or tubular member 10. Complete or partial dissolution would eliminate the need for antiplatelet therapy and reduce radial forces.

[0048] 6, another embodiment of an implantable device 2' includes multiple tubular members 100, 101, 102 arranged in a parallel configuration relative to one another, with each of their respective longitudinal axes parallel to one another and to longitudinal axis "BB." Each of tubular members 100, 101, 102 is substantially similar to tubular member 10, with the differences therebetween being described below.

[0049] Each of the tubular members 100, 101, 102 defines a lumen 112 extending along a longitudinal axis "BB." The tubular members 100, 101, 102 include a distal end portion 114 and a proximal end portion 116. The tubular members 100, 101, 102 include a plurality of interconnected filaments 117 that define a plurality of openings 119 between the interconnected filaments 117.

[0050] The tubular members 100, 101, 102 may have any suitable cross-section and dimensions as described above with respect to tubular member 10. Each of the tubular members 100, 101, 102 may have a different crush resistance ("CR") force. Thus, the first tubular member 100 may have a low CR force, the second tubular member 101 may have a medium CR force, and the third tubular member 102 may have a high CR force. In an embodiment, the low CR force is about 0.002 N / mm 2 ~ approx. 0.004N / mm 2 A moderate CR force may be about 0.003 N / mm 2 ~ approx. 0.006N / mm 2 The high CR force can be about 0.0065 N / mm 2 It could be more than that.

[0051] As described above, as the ICP fluctuates, the dural veins of the brain are compressed or expanded in response to pressure. The ICP may be about 5 mmHg to about 50 mmHg. Thus, a low CR force may be selected to correspond to a first ICP threshold, which may be about 20 mmHg to about 30 mmHg. As the ICP begins to rise, the first tubular member 100 (i.e., the low CR tubular member) is compressed and / or folded first, thereby resulting in a smaller diameter of the vessel, since only the second tubular member 101 and the third tubular member 102 remain open. As the ICP continues to increase, the second tubular member 101 (i.e., the intermediate CR tubular member) is also compressed and / or folded, resulting in further constriction of the vessel. The intermediate CR force may be selected to correspond to a second ICP threshold, which may be about 35 mmHg to about 45 mmHg. The third tubular member 102 can have a high CR, for example 50 mmHg or greater, so that the tubular member 102 does not collapse when the ICP increases, and thus the third lumen 112 remains open.

[0052] In an embodiment, implantable device 2' may include only two tubular members 100 and 101, or any other suitable number, e.g., four or more tubular members. In this embodiment, one of the tubular members of implantable device 2' has a high CR force and is configured to remain in an expanded configuration after deployment regardless of ICP. The remaining tubular members, i.e., one or more, are configured to collapse at a predetermined ICP threshold.

[0053] The first and second tubular members 100 and 101 may be machined or laser cut from a solid tube of material to form interconnected filaments in accordance with the present disclosure to provide a high opening force but relatively low CR force. The third tubular member 102 may be formed by braiding metal wires, polymer filaments, or a combination thereof to form a tubular member with a high CR force to withstand high ICP.

[0054] When an increase in blood pressure occurs (which occurs in response to an increase in ICP), the blood vessel may regain its shape, allowing each of the tubular members 100, 101, 102 to reform to their fully expanded configuration. In an embodiment, the tubular member 10 of the implantable device 2 may have a CR force configured to collapse the tubular member 10 into its collapsible configuration when the ICP reaches a predetermined threshold. When the ICP falls below the threshold, the tubular member 10 returns to its expanded configuration.

[0055] With reference to FIG. 7 , yet another embodiment of implantable device 2″ includes a plurality of tubular members 200 and 202, i.e., an outer tubular member 200 and an inner tubular member 202, disposed in a parallel nested configuration relative to one another, each with their respective longitudinal axes parallel to one another and to longitudinal axis “CC”. Each of tubular members 200 and 202 is substantially similar to tubular member 10, with the differences therebetween being described below.

[0056] The outer tubular member 200 defines a lumen 212 extending along a longitudinal axis "CC." The inner tubular member 200 includes a distal end portion 214 and a proximal end portion 216. The tubular member 202 also defines a lumen 213 having a distal end portion 215 and a proximal end portion 218.

[0057] The inner tubular member 202 is bonded at one or more locations to the inner surface (i.e., filaments 217) of the outer tubular member 200 such that the inner tubular member 200 is disposed within the lumen 212. The outer tubular member 200 and the inner tubular member 202 include a plurality of interconnected filaments 217 that define a plurality of openings 219 between the interconnected filaments 217.

[0058] Each of the tubular members 200 and 202 has a different CR force. Thus, the outer tubular member has a low CR force while the second tubular member 202 has a high CR force. In an embodiment, the low CR force is about 0.002 N / mm 2 ~ approx. 0.004N / mm 2 The high CR force can be about 0.0065 N / mm 2 It could be more than that.

[0059] As described above, as the ICP fluctuates, the dural veins of the brain expand or contract. Thus, a low CR force may be selected to correspond to a first ICP threshold, which may be about 20 mmHg to about 30 mmHg. As the ICP begins to increase, the outer tubular member 200 initially compresses and / or collapses, thereby resulting in a smaller diameter of the vessel. As the ICP continues to increase, the inner tubular member 202 has a high CR, thereby the tubular member 202 does not collapse as the ICP continues to increase. Thus, the lumen 213 remains open.

[0060] The outer tubular member 200 may be machined or laser cut from a solid tube of material to form interconnected filaments to provide a high opening force but relatively low CR force in accordance with the present disclosure. The inner tubular member 202 may be formed by braiding metal wires, polymer filaments, or a combination thereof to form a tubular member with a high CR force to withstand high ICP.

[0061] The implantable devices 2, 2', 2" of FIGS. 1-7 may be delivered to the target vessel, e.g., the cerebral or jugular veins, particularly to the site of maximal sound production, using any suitable transvenous surgical method, which may include transfemoral, transsinus intersection, or internal jugular vein access. Suitable delivery devices include balloon catheters and constrained stent delivery catheters, depending on the type of implantable device being used.

[0062] The implantable device 2, 2', 2" may be implanted within the target vessel by attaching the implantable device 2, 2', 2" to the wall of the target vessel to align the blood flow with the longitudinal axis of the implantable device 2, 2', 2". In an alternative embodiment, the implantable device 2, 2', 2" may be implanted by attaching the distal end portion 14 and the proximal end portion 16 to the wall of the target vessel to position the implantable device 2, 2', 2" across the target vessel and transverse to the blood flow.

[0063] The implantable devices 2, 2', 2" may be self-expanding stents formed from metal or shape memory materials such as those disclosed in U.S. Pat. No. 5,954,744, the entire disclosure of which is incorporated herein by reference, e.g., non-biodegradable materials such as nickel-titanium alloys (nitinol) or shape memory polymers. The implantable devices 2, 2', 2" may be machined or laser cut from a solid tube of material to form interconnected filaments in accordance with the present disclosure. In other embodiments, the implantable devices 2, 2', 2" may be formed by braiding metal wires, polymer filaments, or combinations thereof into the desired shapes as described above with respect to FIGS. 1-7.

[0064] In further embodiments, the implantable devices 2, 2', 2" may be formed from bioabsorbable / biodegradable materials that dissolve or degrade within the vessel. Suitable biodegradable materials include synthetic and naturally derived polymers and copolymers, as well as hybrids, composites, and combinations thereof. Examples of suitable materials include, but are not limited to, polylactide (PLA) [poly-L-lactide (PLLA), poly-DL-lactide (PDLLA)], polyglycolide (PLG or PLGA), polydioxanone, polycaprolactone, polygluconate, polylactic acid-polyethylene oxide copolymer, modified cellulose, collagen, poly(hydroxybutyric acid), polyanhydrides, polyphosphoesters, poly(amino acids), poly(alpha hydroxy acids), or two or more polymerizable monomers such as trimethylene carbonate, ε-caprolactone, polyethylene glycol, 4-tert-butylcaprolactone, N-acetylcaprolactone, poly(ethylene glycol) bis(carboxymethyl) ether, polylactic acid, polyglycolic acid, or polycaprolactone, fibrin, chitosan, or polysaccharides.

[0065] In embodiments, implantable devices 2, 2', 2" may be self-expanding due to the inherent elasticity of certain biodegradable materials, e.g., poly-L-lactide, poly-D-lactide, polyglycolide, etc., such that the filaments return to an expanded state when released from a compressed state. Each type of biodegradable polymer has a characteristic degradation rate in the body. Some materials are relatively fast biodegrading materials (weeks to months) while others are relatively slow biodegrading materials (months to years). The dissolution rate of filaments 17, 117, and 217 depends on the type of biodegradable polymer, the thickness of the biodegradable polymer, and the The dissolution rate of the filaments may be adjusted by controlling the thickness and / or density, and / or properties of the biodegradable polymer. In addition, increasing the thickness and / or density of the polymeric material will generally slow down the dissolution rate of the filaments. Properties such as chemical composition and molecular weight of the biodegradable polymer may also be selected to control the dissolution rate of the filaments. In one embodiment, the filaments may be made of a biodegradable polymer that is degradable within one year and has sufficient mechanical properties to provide wall apposition and strength for at least six months. Anti-fraying technology may optionally be applied to the ends of the filaments to prevent unraveling of the tubular member.

[0066] In embodiments, at least a portion of the implantable device 2, 2', 2" may be coated with a therapeutic agent (not shown), such as a controlled release polymer and / or drug as known in the art to reduce the probability of undesirable side effects, e.g., restenosis. The therapeutic agent may be of the type that dissolves the plaque material that forms the stenosis, or may be an anti-neoplastic agent, an anti-proliferative agent, an antibiotic, an anti-thrombotic agent, an anti-coagulant agent, an anti-platelet agent, an anti-inflammatory agent, combinations of the above, and the like. Such drugs may include, for example, zotarolimus, rapamycin, VEGF, TPA, heparin, urokinase, or sirolimus. The implantable device 2, 2', 2" may be used to deliver any suitable agent to the wall of a vessel in the body.

[0067] It should be understood that various modifications may be made to the embodiments disclosed herein. In particular, an implantable device according to the present disclosure may be implanted in any suitable blood vessel. Thus, the above description should not be construed as limiting the various embodiments, but merely as illustrative thereof. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. 14. An implantable device comprising: a tubular member defining a longitudinal axis and a lumen, the tubular member comprising: a plurality of interconnected filaments, the plurality of interconnected filaments defining a plurality of openings therebetween; a distal end portion having a triangular cross-sectional shape and a first cross-sectional dimension; a proximal end portion having a second cross-sectional dimension larger than the first cross-sectional dimension and having a circular or elliptical cross-sectional shape; 13. An implantable device comprising:

2. 10. The implantable device of claim 1, wherein the second cross-sectional dimension is from about 10 mm to about 14 mm and the first cross-sectional dimension is from about 4 mm to about 8 mm.

3. The implantable device of claim 1 , wherein the second cross-sectional dimension is about 2 to about 3 times larger than the first cross-sectional dimension.

4. 10. The implantable device of claim 1, further comprising an attachment member including a plurality of attachment filaments and a hook coupled to the plurality of attachment filaments.

5. 5. The implantable device of claim 4, wherein rotation of the attachment member about the longitudinal axis in a first direction expands the tubular member and rotation of the attachment member about the longitudinal axis in a second direction opposite the first direction constrains the tubular member.

6. The implantable device of claim 4 , wherein the tubular member is formed from a non-biodegradable material and the attachment member is formed from a biodegradable material.

7. 10. The implantable device of claim 1, wherein the radially outward pressure exerted by the tubular member when the tubular member is compressed to approximately 30% of its nominal state is between about 20 mmHg and about 50 mmHg.

8. An implantable device as described in claim 1, wherein under nominal conditions, the radially outward pressure exerted by the tubular member is between about 10 mmHg and about 30 mmHg.

9. The implantable device of claim 1, wherein when fully compressed, the radially outward pressure exerted by the tubular member is from about 30 mmHg to about 200 mmHg.

10. 10. The implantable device of claim 9, wherein the radially outward pressure exerted by the tubular member when fully compressed is between about 40 mmHg and about 60 mmHg.

11. the implantable device is configured to treat a cerebral dural sinus; the implantable device is configured to fold into a folded configuration; the implantable device is configured to be inserted into the cerebral dural sinus; The implantable device of any one of claims 1-10, wherein the implantable device is configured to expand into an expandable configuration inside the cerebral dural venous sinus.

12. 12. The implantable device of claim 11, wherein the implantable device is further configured to be placed within the dural venous sinus such that the proximal end portion is positioned adjacent to a sigmoid sinus of the cerebral dural venous sinus and the distal end portion is positioned adjacent to a sinus intersection of the cerebral dural venous sinus.

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