Cerebral dural venous sinus stent

Abstract

To provide a favorable cerebral dural venous sinus stent.SOLUTION: An implantable device comprises a tubular member defining a longitudinal axis and a lumen. The tubular member comprises: 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 that is larger than the distal diameter; and an intermediate portion having an intermediate diameter that is smaller than the distal diameter. In one 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.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit and priority of U.S. Provisional Patent Application No. 62 / 984,549, filed Mar. 3, 2020. The entire disclosure of the foregoing application is incorporated herein by reference.

Background Art

[0002] Idiopathic intracranial hypertension (IIH) is a common disorder that afflicts young, overweight women in whom increased intracranial pressure can lead to severe symptoms such as blindness and cognitive decline, as well as headache and pulsatile tinnitus (PT). Dural venous sinus stenting is an emerging therapy for IIH patients and PT patients who suffer from venous sinus stenosis. To be eligible for the therapy, intracranial pressure measurements are taken and a sufficient pressure gradient across the stenosis is measured in patients who are minimally or not at all under sedation (typically, greater than 5 or 8 mmHg). However, the implantation of currently available stents designed for either carotid or peripheral venous use is very difficult for the operator and painful for the patient due to the stiffness of the carotid stents and the high radial forces. 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 be treated only with steroids. Steroids in IIH patients are very risky because the discontinuation of steroids can itself exacerbate the underlying IIH condition.

[0003] Currently available stents, such as typical carotid stents, are not stocked in lengths or configurations suitable for treating IIH. In particular, carotid stents are not stocked in sufficiently long configurations, do not have a suitable diameter, and are mainly rounded in shape. In response, many operators are using multiple stent configurations that vary widely in size. This exposes the patient to increased procedural risks (the risk of potentially mismatching the stent or having dimensions that are too short), which can lead to stent migration (if a stent that is too small is used) or headache (if a stent that is too large is used).

[0004] In addition, many patients suffering from PT have stenosis of the cavernous sinus, which is the source of their PT. However, many cases of cavernous sinus stenosis are asymptomatic. The only currently available stent for treating cavernous sinus stenosis is a permanent implant that needs to be placed in a patient under general anesthesia. A stent that could be positioned safely and painlessly while the patient is awake would allow the patient to report immediately whether their symptoms have improved upon deployment of the stent. In patients in whom the symptoms are worsened or not improved by stent placement, current technology does not allow removal of the stent.

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

[0006] Accordingly, there is a need for improved treatment methods and devices to address the drawbacks of conventional stents. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0007] The present disclosure provides a stent configured and designed for the unique environment of the dural venous sinuses, particularly the sigmoid sinuses of the cerebral dural veins and the dural venous sinus confluence regions. The stent may be tapered and include a flexible proximal tip that can cross the venous sinus and stenosis easily and with substantially no pain. The disclosed stent has a sufficiently low radial force to open a venous sinus stenosis that can be from about 0.1 Newton per square millimeter (about 0.1 N / mm 2 ) to about 0.2 N / mm 2 .

[0008] As used herein, the term "distal" refers to the portion of the implantable device that is farther 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. Accordingly, the proximal portion may be disposed adjacent to the S-shaped sinus venosus, and the distal portion may be disposed adjacent to the venous sinus junction after implantation.

[0009] As used herein, the terms "biodegradable" and "bioabsorbable" are used with respect to the properties of materials. "Biodegradable" is a material that can decay or decompose in vivo and then be excreted. "Bioabsorbable" is a material that can decay or decompose in vivo and then be resorbed. Both biodegradable materials and bioabsorbable materials are suitable for the purposes of this application, and thus, for simplicity, unless otherwise indicated, biodegradable materials and bioabsorbable 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 decompose in vivo. Additionally, the term "dissolution" as used in the description refers to the decomposition of both biodegradable materials and bioabsorbable materials.

[0010] The radial force of the stent is such that it becomes greater when the stent is folded and smaller when the stent is expanded. Such a design allows the stent to temporarily narrow to a certain extent due to a normal transient increase in intracranial pressure, but then be able to withstand further compression. By contracting in response to an elevated intracranial pressure (ICP), the stent will cause a temporary venous pulmonary hypertension to withstand the collapse of the untreated dural venous sinus during a transient change in ICP. When the transient ICP increase resolves, i.e., the ICP decreases, the stent will expand again. Conventional stents do not change their expansion size in response to changes in ICP due to their high radial force (or high crush resistance). As a result, conventional stents can expand the vessel beyond its natural diameter, resulting in a wider section. At the junction of the non-stented and stented portions of the blood vessel, the blood flow can result in a violent blood flow and the resulting pressure drop. Thus, conventional stents may not function at their junction points.

[0011] The stent according to the present disclosure may have any suitable cross-section, such as an elliptical, circular, triangular, rectangular, polygonal, etc., suitable for the geometry of the blood vessel, i.e., the dural venous 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., a larger diameter) to a distal portion (i.e., a 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 adjacent to or disposed within the S-shaped venous sinus. The distal portion may be adjacent to the venous sinus intersection or disposed within the superior sagittal venous sinus. The tapered portion minimizes changes in the shape and cross-sectional area of the blood vessel and limits the occurrence of turbulent flow.

[0012] Secondary stents can also be used to treat the unique anatomical considerations of the posterior third of the superior vena cava. The diameter can be from about 4 mm to about 5 mm throughout its length and can have the ability to expand more widely to accommodate the vena cava confluence. It can also be tapered from about 3 mm distally to about 6 mm proximally. It can be tapered such that it has a cross-sectional area similar to that of the natural sinus. It can thus have an expanded portion to a wider diameter to accommodate the vena cava confluence. The secondary stent can be about 60 - 100 mm in length.

[0013] The stent can have a closed-cell design or a braided design such that the structure allows for reversible expansion and folding of the stent, enabling the stent to be retrievable. In embodiments, the stent can have an open-cell design to minimize radial force. In embodiments, the stent can be mounted on a wire to facilitate retrievability. In further embodiments, the stent can have a hook configuration on the side of the stent proximate to the jugular vein to enable the operator to retrieve the stent. Pulling on the hook adjusts the dimensions and shape of the stent, i.e., changes the shape of the tapered portion. The hook also enables the stent to be recaptured by a catheter having a corresponding hook. The stent can be formed from a biodegradable material such that the stent dissolves after a period of time, i.e., when the stent has "healed" in a given position. The stent can be formed from a degradable material such that a reagent, or chemical, or other material that dissolves or degrades the stent can be injected into the stent, adjacent to the stent, or systemically when the stent is no longer required after a period of time.

[0014] The disclosed stent 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 prevalence of obesity spreads, this patient population is expected to continue to grow. Most of these patients can be well treated using the cavernous sinus stents according to the present disclosure. Alternative conventional therapies have significant limitations, including inadequate safety records, high rates of replacement therapy, or difficulties with patient acceptability. PT afflicts 3 to 5 million Americans and has a very high comorbidity association with depression, anxiety, and even suicidal thoughts. There are very few effective conventional treatments for PT.

[0015] According to one embodiment of the present disclosure, an implantable device is disclosed. 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 larger than the distal diameter, and an intermediate portion having an intermediate diameter smaller than the distal diameter.

[0016] According to one 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. The intermediate diameter is from about 4 mm to about 7 mm. The proximal diameter can 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, and the wire is coupled to the tubular member. The tubular member is formed of a non-biodegradable material, and the wire is formed of a biodegradable material. According to a further aspect of the above embodiment, the tubular member is formed of 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 smaller than the distal diameter.

[0020] According to one aspect of the above embodiment, the proximal end portion is disposed adjacent to the S-shaped sinus of the cerebral dural venous sinus. The distal end portion is disposed adjacent to the sinus confluence of the cerebral dural venous sinus. The stent may be long enough such that the distal end of that portion is disposed within the superior sagittal sinus.

[0021] 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 filament. 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 to the first direction to constrain the tubular member.

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

[0023] According to yet another aspect of the above-described 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 crushing resistance equal to an intracranial pressure threshold such that each of the tubular members is configured to fold in response to an intracranial pressure that rises above the threshold and expand in response to an intracranial pressure that falls below the threshold. In other words, each of the tubular members has a different threshold pressure at which it folds. Some fold at a high but normal physiological range of ICP. Some fold at a very high ICP, and some are essentially always open.

[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 crushing resistance equal to a first intracranial pressure threshold such that the first expandable tubular member is configured to fold in response to an intracranial pressure that rises above the first intracranial pressure threshold and expand in response to an intracranial pressure that falls below the first intracranial pressure threshold. The implantable device further includes a second expandable tubular member in contact with and arranged parallel to the first expandable tubular member, the second expandable tubular member having a crushing resistance equal to a second intracranial pressure threshold such that the second expandable tubular member is configured to fold in response to an intracranial pressure that rises above the second intracranial pressure threshold and expand in response to an intracranial pressure that falls below the second intracranial pressure threshold.

[0026] According to one aspect of the above-described 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) An implantable device, the implantable device comprising a tubular member defining a longitudinal axis and a lumen, the tubular member 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, and an intermediate portion having an intermediate diameter smaller than the distal diameter An implantable device having the same. (Item 2) The implantable device according to 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) The implantable device according to item 1, wherein the proximal diameter is about 2 to about 3 times larger than the distal diameter. (Item 4) The implantable device according to item 1, further comprising an attachment member including a plurality of attachment filaments and hooks coupled to the attachment filaments. (Item 5) The implantable device according to item 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 to the first direction restrains the tubular member. (Item 6) The implantable device according to item 4, wherein the tubular member is formed of a non-biodegradable material and the attachment member is formed of a biodegradable material. (Item 7) The implantable device according to item 1, further comprising a wire disposed through the lumen and coupled to the tubular member. (Item 8) The implantable device according to item 7, wherein the tubular member is formed of a non-biodegradable material and the wire is formed of a biodegradable material. (Item 9) The implantable device according to item 1, wherein the tubular member is formed of a biodegradable material. (Item 10) A method for treating a cerebral dural venous sinus, the method comprising: 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 larger than the distal diameter; and an intermediate portion having an intermediate diameter smaller than the distal diameter; inserting the implantable device into the cerebral dural venous sinus; and expanding the implantable device within the cerebral dural venous sinus to an expandable configuration. The method according to item 10, further comprising installing the implantable device within the dural venous sinus such that the proximal end portion is disposed adjacent to the sigmoid sinus of the cerebral dural venous sinus and the distal end portion is disposed adjacent to the venous sinus confluence of the cerebral dural venous sinus. The method according to item 10, further comprising: (Item 11) The implantable device further comprises an attachment member including a plurality of attachment filaments and hooks coupled to the attachment filaments. (Item 12) The method according to item 12, further comprising rotating the attachment member about the longitudinal axis in a first direction to expand the tubular member. (Item 13) The method according to item 13, further comprising rotating the attachment member about the longitudinal axis in a second direction opposite to the first direction to constrain the tubular member. (Item 14) (Item 15) (Item 15) The method according to item 12, wherein the tubular member is formed of a non-biodegradable material and the attachment member is formed of a biodegradable material. (Item 16) The method according to item 15, further comprising injecting a reagent into the cerebral dural venous sinus and dissolving at least a part of the attachment member. (Item 17) 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) An implantable device, 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 having a crushing resistance equal to an intracranial pressure threshold, whereby each of the tubular members is configured to be folded in response to an intracranial pressure rising above the threshold and to expand in response to the intracranial pressure dropping below the threshold. (Item 19) An implantable device, wherein the implantable device A first expandable tubular member having a crushing resistance equal to a first intracranial pressure threshold, whereby the first expandable tubular member is configured to be folded in response to an intracranial pressure rising above the first intracranial pressure threshold and to expand in response to the intracranial pressure dropping below the first intracranial pressure threshold, A second expandable tubular member in contact with and arranged parallel to the second expandable tubular member and comprising The second expandable tubular member has a crushing resistance equal to a second intracranial pressure threshold, whereby the second expandable tubular member is configured to be folded in response to an intracranial pressure rising above the second intracranial pressure threshold and to expand in response to the intracranial pressure dropping below the second intracranial pressure threshold. (Item 20) The first intracranial pressure threshold and the second intracranial pressure threshold are different, the implantable device according to item 19.

Brief Description of the Drawings

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

[0028]

Figure 1

[0029]

Figure 2

[0030]

Figure 3

[0031]

Figure 4

[0032]

Figure 5

[0033]

Figure 6

[0034]

Figure 7

Mode for Carrying Out the Invention

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

[0036] The present disclosure provides a method of treating IIH and PT by inserting a catheter into a cerebral venous sinus and implanting a device. A suitable implantable device according to the present disclosure can be a self-expanding or balloon-expandable stent having outer walls of various diameters.

[0037] The implantable device is constrained within a catheter and, when released at a target location within a target vein or any other vascular location, can self-expand, contact the vessel wall, press against it, and prevent movement of the device. In embodiments, the device can 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 the entry of veins from cortical veins or the internal jugular vein into larger sinuses. Thus, the device is minimally thrombogenic to minimize the risk of embolism to the entire systemic venous circulation and pulmonary arterial system, as thrombosis can lead to occlusion of the parent venous sinus.

[0038] Referring to FIGS. 1 - 3, an implantable device 2 according to the present disclosure, such as a stent, includes a tubular member 10 defining a lumen 12 that extends along a longitudinal axis “A - A”. 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, and the plurality of interconnected filaments 17 define a plurality of openings 19 therebetween. The tubular member 10 is configured to contact the wall of a vessel, such as a dural venous sinus.

[0039] Following the implantation, the distal end portion 14 can be disposed adjacent to the vena cava junction and the proximal end portion 16 can be disposed adjacent to the S-shaped vena cava after implantation. The tubular member 10 can have any suitable cross-sectional shape that conforms to the natural shape of a blood vessel, such as oval, circular, polygonal (i.e., triangular or rectangular), etc. As shown in FIG. 2, the tubular member 10 can have a triangular cross-section, which more closely approximates a certain vascular shape than a circular tubular member 10. As described above, a geometric mismatch between the stent and the blood vessel can result in the generation of turbulent flow.

[0040] In a further embodiment, the proximal end portion 16 can have a proximal cross-sectional shape while the distal end portion 14 can have a distal cross-sectional shape that is different from the first cross-sectional shape to allow for better conformity. The proximal cross-sectional shape can be triangular and the distal cross-sectional shape can be rectangular, oval, or circular for better conformity within the S-shaped vena cava.

[0041] The radial force of the tubular member 10 can be characterized as the crushing resistance force, i.e., the force required to fold the tubular member 10, and a long-lasting radially outward force, i.e., the long-lasting pressure applied by the tubular member 10 when in the nominal state (i.e., the expanded configuration). In the nominal state, the radial force can be from about 0 mmHg to 100 mmHg, and in an embodiment, the radial force can be from about 10 mmHg to about 30 mmHg. The long-lasting radially outward force in the nominal state can be from about 0 mmHg to about 30 mmHg, and in an embodiment, it can be from about 0 mmHg to about 10 mmHg. The radial resistance force at approximately 30% of the nominal state can be from about 20 mmHg to about 70 mmHg, and in an embodiment, it can be from about 30 mmHg to about 50 mmHg. The long-lasting radially outward force at approximately 30% of the nominal state can be from about 15 mmHg to about 70 mmHg, and in an embodiment, it can be from about 20 mmHg to about 50 mmHg. The radial force when the tubular member 10 is completely constrained can be from about 30 mmHg to about 200 mmHg, and in an embodiment, it can be from 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 movement, but is low enough so that the nominal radial force does not cause dural inflammation.

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

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

[0044] Referring to FIG. 4, the tubular member 10 can include an optional attachment member 20 coupled thereto. The attachment member 20 can include an optional loop 21 coupled to one or more attachment filaments 22. The loop 21 and / or the attachment filaments 22 can be continuous with the filament 17 and can be woven, braided, or otherwise coupled to the tubular member 10 (FIG. 4). In an embodiment, the attachment filament 22 can be coupled to a hook 24. The loop 21 can be coupled to an intermediate location of the tubular member 10 such that the loop 21 is adjacent to the intermediate diameter d3. Pulling and / or rotating the attachment filament 22 using the hook 24 modifies the shape of the tubular member 10 by adjusting the size of the intermediate diameter d3. In an embodiment, the attachment filament 22 is rotated in either direction about the longitudinal axis “A-A” via the hook 24. Thus, rotating in a first (e.g., clockwise) direction a expands the tubular member 10 and increases the intermediate diameter d3, and rotating in a second (e.g., counterclockwise) direction b constrains the tubular member 10 and decreases the intermediate diameter d3. This will enable determination of a more patient-specific size of the tubular member 10, adjustment of the radial forces, and potential removal. In a further embodiment, the hook 24 enables an external device such as a recapture catheter (not shown) to attach to the tubular member 10 to remove the tubular member 10.

[0045] Referring to FIG. 5, the tubular member 10 can be connected to the wire 30 via the attachment filament 22. The wire 30 can be disposed within and through the lumen 12 and be parallel to the longitudinal axis "A - A". The wire 30 can be used to expand or constrain the tubular member 10 by rotation, in a manner similar to the hook 24, whereby the intermediate diameter d3 of the tubular member 10 can be adjusted after implantation. The tubular member 10 can also include a tapered proximal conical portion 26 coupled to the proximal end portion 16 disposed over the attachment filament 22. The shape of the tapered proximal conical portion 26 provides for an easy and substantially painless traversal of the atrium and stenosis.

[0046] Since various blood vessels have different blood flow parameters and characteristics, it would be useful to adjust the intermediate diameter d3 of the tubular member 10 according to the characteristics of the blood flow using the attachment filament 22, the hook 24, and / or the wire 30. The tubular member 10 of FIGS. 1 - 5 can also include a plurality 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 fixed within the vasculature and minimize movement of the tubular member 10 after implantation.

[0047] In an embodiment, the attachment filament 22, the hook 24, and / or the wire 30 can be removably coupled to the tubular member 10 by using a release mechanism that can be mechanical, electrolytic, or chemical. In an embodiment, the tubular member 10 can be formed from a non-biodegradable material and the attachment filament 22, the hook 24, and / or the wire 30. With respect to the chemical release mechanism, a reagent is injected either systemically intravenously or locally via a catheter positioned within the venous system “upstream” from the tubular member 10, which can dissolve the attachment points that couple the attachment filament 22, the hook 24, and / or the wire 30 to the tubular member 10. In a further embodiment, the attachment filament 22, the hook 24, the wire 30, and the tubular member 10 can be formed from a biodegradable material, the dissolution of which can be accelerated by an injected reagent that dissolves some or all of the attachment filament 22, the hook 24, the wire 30, and / or the tubular member 10. Complete or partial dissolution would obviate the need for antiplatelet therapy and reduce the radial force.

[0048] Referring to FIG. 6, another embodiment of the implantable device 2’ includes a plurality of tubular members 100, 101, 102 arranged in a configuration parallel to each other, each of the longitudinal axes of which are parallel to each other and to the longitudinal axis “B-B”. Each of the tubular members 100, 101, 102 is substantially similar to the tubular member 10, the differences between them being described below.

[0049] Each of the tubular members 100, 101, 102 defines a lumen 112 that extends along the longitudinal axis “B-B”. 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 therebetween.

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

[0051] As described above, when the ICP fluctuates, the cerebral dural veins are compressed or expanded in response to the pressure. The ICP can be about 5 mmHg to about 50 mmHg. Thus, a low CR force can be selected to correspond to a first ICP threshold that can be about 20 mmHg to about 30 mmHg. When the ICP begins to rise, only the second tubular member 101 and the third tubular member 102 remain open, so the first tubular member 100 (i.e., the low CR tubular member) is compressed and / or folded first, thereby resulting in a small diameter of the blood vessel. 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 blood vessel. The intermediate CR force can be selected to correspond to a second ICP threshold that can be about 35 mmHg to about 45 mmHg. The third tubular member 102 can have a high CR, for example, a value of 50 mmHg or more, whereby the tubular member 102 is not folded when the ICP increases. Thus, the third lumen 112 remains open.

[0052] In an embodiment, the implantable device 2' may include only two tubular members 100 and 101, or any other suitable number, for example, four or more tubular members. In this embodiment, one of the tubular members of the implantable device 2' has a high CR force and is configured to remain in an expanded configuration after deployment regardless of the ICP. The remaining tubular members, i.e., one or more of them, are configured to fold 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 and interconnected filaments according to the present disclosure, forming a relatively low CR force but a high opening force. The third tubular member 102 may be formed by braiding a metal wire, a polymer filament, or a combination thereof to form a tubular member having a high CR force that withstands a high ICP.

[0054] When an increase in blood pressure occurs (which occurs in response to an increase in ICP), the blood vessel may be able to return to its shape and allow each of the tubular members 100, 101, 102 to reform into its fully expanded configuration. In an embodiment, the tubular member 10 of the implantable device 2 may have a CR force configured to fold the tubular member 10 into its foldable configuration when the ICP reaches a predetermined threshold. When the ICP drops below the threshold, the tubular member 10 returns to its expanded configuration.

[0055] Referring to FIG. 7, yet another embodiment of the implantable device 2” includes a plurality of tubular members 200 and 202, namely, an outer tubular member 200 and an inner tubular member 202, which are arranged in a nested configuration parallel to each other, and each of their longitudinal axes is parallel to each other and to the longitudinal axis “C-C”. Each of the tubular members 200 and 202 is substantially similar to the tubular member 10, and the differences between them are described below.

[0056] The outer tubular member 200 defines a lumen 212 that extends along the longitudinal axis "C-C". 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 coupled at one or more locations on the inner surface of the outer tubular member 200 (i.e., the filament 217) 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 therebetween.

[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 can be from about 0.002 N / mm 2 to about 0.004 N / mm 2 The high CR force can be about 0.0065 N / mm or more. 2

[0059] As described above, when the ICP varies, the cerebral dural veins expand or contract. Thus, the low CR force can be selected to correspond to a first ICP threshold that can be from about 20 mmHg to about 30 mmHg. When the ICP begins to increase, the outer tubular member 200 is first compressed and / or folded, thereby resulting in a smaller diameter of the vasculature. As the ICP continues to increase, the inner tubular member 202 has a high CR such that the tubular member 202 does not fold as the ICP continues to increase. Thus, the lumen 213 remains open.

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

[0061] The implantable devices 2, 2', 2" of FIGS. 1-7 can be delivered to a target vasculature, such as a cerebral vein or jugular vein, particularly at the location of maximum sound generation, using any suitable transvenous surgical method that may include a trans-femoral, trans-septal, or internal jugular vein access. Suitable delivery devices include balloon catheters and stented delivery catheters depending on the type of implantable device being used.

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

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

[0064] In further embodiments, the implantable devices 2, 2', 2'' can be formed from bioabsorbable / biodegradable materials that dissolve or degrade within the vasculature. Suitable biodegradable materials include synthetic and natural-derived polymers and copolymers, and 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, poly(lactic acid)-poly(ethylene 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 an embodiment, the implantable devices 2, 2', 2'' can be self-expanding due to the inherent elastic force of a specific biodegradable material such as poly-L-lactide, poly-D-lactide, polyglycolide, etc., such that the filament returns 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 those that biodegrade relatively rapidly (weeks to months), while others are those that biodegrade relatively slowly (months to years). The dissolution rate of filaments 17, 117, and 217 can be adjusted by controlling the type of biodegradable polymer, the thickness and / or density of the biodegradable polymer, and / or the properties of the biodegradable polymer. Additionally, increasing the thickness and / or density of the polymer material will generally slow down the dissolution rate of the filament. Properties such as the chemical composition and molecular weight of the biodegradable polymer can also be selected to control the dissolution rate of the filament. In one embodiment, the filament can be made from a biodegradable polymer that degrades within one year and has sufficient mechanical properties to provide wall apposition and strength for at least six months. Anti-fraying techniques can optionally be applied to the ends of the filaments to prevent fraying of the tubular member.

[0066] In an embodiment, at least a portion of the implantable devices 2, 2', 2'' can be coated with a therapeutic agent (not shown) such as a controlled release polymer and / or a drug, as known in the art, since it reduces the probability of unwanted side effects, such as restenosis. The therapeutic agent can be of a type that dissolves plaque material that forms stenosis, or can be an anti-cancer agent, an anti-proliferative agent, an antibiotic, an anti-thrombotic agent, an anticoagulant, an antiplatelet agent, an anti-inflammatory agent, a combination of the above, etc. Such drugs can include, for example, zotarolimus, rapamycin, VEGF, TPA, heparin, urokinase, or sirolimus. The implantable devices 2, 2', 2'' can be used to deliver any suitable agent to the walls of the body's vasculature.

[0067] It should be understood that various modifications can be made to the embodiments disclosed herein. In particular, the implantable devices according to the present disclosure can be implanted in any suitable blood vessel. Accordingly, the above description should not be construed as limiting the various embodiments, but rather should be construed 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; and a proximal end portion opposite the distal end portion; having An implantable device, wherein at least one of the distal end portion or the proximal end portion has a triangular cross-sectional shape.

2. The implantable device of claim 1, wherein the distal end portion has a triangular cross-sectional shape and the proximal end portion has a cross-sectional shape that is at least one of an elliptical, circular, rectangular, or polygonal cross-sectional shape.

3. The implantable device of claim 1, wherein the proximal end portion has a triangular cross-sectional shape and the distal end portion has a cross-sectional shape that is at least one of an elliptical, circular, rectangular, or polygonal cross-sectional shape.

4. The implantable device of claim 1, wherein each of the distal end portion and the proximal end portion has a triangular cross-sectional shape.

5. The implantable device according to claim 1, wherein the distal end portion has a distal cross-sectional dimension and the proximal end portion has a proximal cross-sectional dimension. The implantable device of claim 1 , further comprising an intermediate portion having an intermediate cross-sectional dimension less than at least one of the distal cross-sectional dimension or the proximal cross-sectional dimension.

6. The implantable device according to claim 1, wherein the distal end portion has a distal cross-sectional dimension and the proximal end portion has a proximal cross-sectional dimension. The implantable device of claim 1 , further comprising an intermediate portion having an intermediate cross-sectional dimension less than both the distal and proximal cross-sectional dimensions such that the tubular member has an hourglass shape.

7. An attachment member coupled to the tubular member, the attachment member including a plurality of attachment filaments; a hook coupled to the plurality of attachment filaments; 10. The implantable device of claim 1 further comprising:

8. 8. The implantable device of claim 7, 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.

9. The method of claim 8, further comprising: disposing a wire through the lumen and coupled to the tubular member; The implantable device of claim 1 , wherein the tubular member is formed from a non-biodegradable material and the wire is formed from a biodegradable material.

10. The implantable device of claim 1, wherein the tubular member is formed from a biodegradable material.

11. An implantable device as described in claim 1, wherein the radial outward pressure exerted by the tubular member when the tubular member is compressed to approximately 30% of its nominal state is between 15 mmHg and 70 mmHg.

12. 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 20 mmHg and 50 mmHg.

13. The implantable device of claim 1, wherein in a nominal state of the tubular member, the radially outward pressure exerted by the tubular member is between 10 mmHg and 30 mmHg.

14. An implantable device as described in claim 1, wherein the radially outward pressure exerted by the tubular member when the tubular member is fully restrained is between 30 mmHg and about 200 mmHg.

15. 10. The implantable device of claim 1, wherein the radially outward pressure exerted by the tubular member when fully constrained is between 40 mmHg and 60 mmHg.

Images