Implantable damping devices for the treatment of dementia

Description

TECHNICAL FIELD

[0001] The present technology relates to implantable damping devices for treating dementia and associated systems and methods of use. In particular, the present technology is directed to damping devices for treating an artery.BACKGROUND

[0002] The heart supplies oxygenated blood to the body through a network of interconnected, branching arteries starting with the largest artery in the body-the aorta. As shown in the schematic view of the heart and selected arteries in Figure 1A, the portion of the aorta closest to the heart is divided into three regions: the ascending aorta (where the aorta initially leaves the heart and extends in a superior direction), the aortic arch, and the descending aorta (where the aorta extends in an inferior direction). Three major arteries branch from the aorta along the aortic arch: the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. The brachiocephalic artery extends away from the aortic arch and subsequently divides into the right common carotid artery, which supplies oxygenated blood to the head and neck, and the right subclavian artery, which predominantly supplies blood to the right arm. The left common carotid artery extends away from the aortic arch and supplies the head and neck. The left subclavian artery extends away from the aortic arch and predominantly supplies blood to the left arm. Each of the right common carotid artery and the left common carotid artery subsequently branches into separate internal and external carotid arteries.

[0003] During the systole stage of a heartbeat, contraction of the left ventricle forces blood into the ascending aorta that increases the pressure within the arteries (known as systolic blood pressure). The volume of blood ejected from the left ventricle creates a pressure wave-known as a pulse wave-that propagates through the arteries propelling the blood. The pulse wave causes the arteries to dilate, as shown schematically in Figure 1B. When the left ventricle relaxes (the diastole stage of a heartbeat), the pressure within the arterial system decreases (known as diastolic blood pressure), which allows the arteries to contract.

[0004] The difference between the systolic blood pressure and the diastolic blood pressure is the "pulse pressure," which generally is determined by the magnitude of the contraction force generated by the heart, the heart rate, the peripheral vascular resistance, and diastolic "run-off" (e.g., the blood flowing down the pressure gradient from the arteries to the veins), amongst other factors. High flow organs, such as the brain, are particularly sensitive to excessive pressure and flow pulsatility. To ensure a relatively consistent flow rate to such sensitive organs, the walls of the arterial vessels expand and contract in response to the pressure wave to absorb some of the pulse wave energy. As the vasculature ages, however, the arterial walls lose elasticity, which causes an increase in pulse wave speed and wave reflection through the arterial vasculature. Arterial stiffening impairs the ability of the carotid arteries and other large arteries to expand and dampen flow pulsatility, which results in an increase in systolic pressure and pulse pressure. Accordingly, as the arterial walls stiffen over time, the arteries transmit excessive force into the distal branches of the arterial vasculature.

[0005] Research suggests that consistently high systolic pressure, pulse pressure, and / or change in pressure over time (dP / dt) increases the risk of dementia, such as vascular dementia (e.g., an impaired supply of blood to the brain or bleeding within the brain). Without being bound by theory, it is believed that high pulse pressure can be the root cause or an exacerbating factor of vascular dementia and age-related dementia (e.g., Alzheimer's disease). As such, the progression of vascular dementia and age-related dementia (e.g., Alzheimer's disease) may also be affected by the loss of elasticity in the arterial walls and the resulting stress on the cerebral vessels. Alzheimer's Disease, for example, is generally associated with the presence of neuritic plaques and tangles in the brain. Recent studies suggest that increased pulse pressure, increased systolic pressure, and / or an increase in the rate of change of pressure (dP / dt) may, over time, cause microbleeds within the brain that may contribute to the neuritic plaques and tangles. Accordingly, there is a need for improved devices, systems, and methods for treating vascular and / or age-related dementia.

[0006] United States Patent Application Publication n° US 2012 / 029625 A1 discloses a barbed radially expandable stent. United States Patent Application Publication n° US 2013 / 079871 A1 discloses vascular elastance.

[0007] A selective circumferential pressure applicator of United States Patent Application Publication n° US 2011 / 0213408 A1 includes at least two surfaces that increase baroreceptor activity of the subject, by applying pressure to an artery of the subject at two or more respective non-contiguous regions around the circumference of the artery, at a longitudinal site of the artery, such that between the non-contiguous regions, at the longitudinal site (a) there is at least one region of the artery that is more relaxed than in the absence of the device, and (b) there is at least one region of the artery that is more tense than in the absence of the device. A joint couples the surfaces to each other.

[0008] United States Patent Publication n° US 4,881,939 A shows an implantable, inflatable helical cuff which is wrapped about a tubular body member such as a nerve cord, esophagus, colon, intestine, or blood vessel in a pressure transferring relationship.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Many aspects of the present disclosure can be better understood with reference to the following drawings, of which Figures 16A to 18B illustrate the invention and wherein devices of the preceding Figures are described as reference devices. The invention is defined in the claims, and the components in the drawings are not necessarily to scale. Figure 1A is a schematic illustration of a human heart and a portion of the arterial system near the heart. Figure 1B is a schematic illustration of a pulse wave propagating along a blood vessel. Figure 2A is a front view of a damping device shown in a deployed, relaxed state. Figure 2B is a front cross-sectional view of the damping device shown in Figure 2A. Figure 2C is a front cross-sectional view of the damping device shown in Figure 2A, shown in a deployed state positioned within a blood vessel. Figure 2D is a front cross-sectional view of another damping device shown in a deployed, relaxed state Figures 2E-2G are front cross-sectional views of several damping members, all shown in a deployed, relaxed state. Figure 3A is a front cross-sectional view of another damping device in a deployed, relaxed state. Figures 3B-3D are front cross-sectional views of several damping members, all shown in a deployed, relaxed state. Figure 4A is a front view of another damping device shown in a deployed, relaxed state. Figure 4B is a front cross-sectional view of the damping device shown in Figure 4A. Figure 4C is a front cross-sectional view of the damping device shown in Figure 4A, shown in a deployed state positioned within a blood vessel. Figure 4D is a front cross-sectional view of a portion of a damping member showing deformation of the damping member (in dashed lines) in response to a pulse wave. Figure 4E is a front cross-sectional view of a portion of another damping member showing deformation of the damping member (in dashed lines) in response to a pulse wave. Figures 5-7 are front cross-sectional views of several damping devices. Figures 8A-8E illustrate a method of delivering a damping device to an artery. Figures 9A-9F are schematic cross-sectional views of several damping members. Figures 10 and 11 are front cross-sectional views of damping devices shown positioned at or near a resected blood vessel. Figure 12A is a front view of a helical damping device shown positioned around a blood vessel in a deployed, relaxed state. Figure 12B is a cross-sectional view of the damping device of Figure 12A (taken along line 12B-12B in Figure 12A), shown positioned around the blood vessel as a pulse pressure wave travels through the vessel. Figures 13 and 14 show different wrapped damping devices, each shown positioned around a blood vessel. Figure 15 is a cross-sectional view of another damping device. Figure 16A is a perspective view of another damping device. Figure 16B is a cross-sectional view of the damping device shown in Figure 16A, taken along line 16B-16B. Figure 17A is a perspective view of another damping device. Figure 17B is a cross-sectional view of the damping device shown in Figure 17A. Figure 18A is a perspective view of another damping device. Figure 18B is a front view of the damping device shown in Figure 18A, shown in a deployed state positioned around a blood vessel. Figure 19A is a perspective view of another damping device shown in an unwrapped state. Figure 19B is a top view of the damping device shown in Figure 19A, shown in an unwrapped state. DETAILED DESCRIPTION

[0010] The present disclosure is directed to implantable damping devices for treating or slowing the progression of dementia, which includes both vascular dementia and age-related dementia, and associated systems and methods of use. Some damping devices, for example, are directed to damping devices including an anchoring member and a flexible, compliant damping member having an outer surface and an inner surface defining a lumen configured to direct blood flow. The inner surface is configured such that a cross-sectional dimension of the lumen varies. For example, the outer surface and the inner surface can be separated from each other by a distance that varies along the length of the damping member. The damping member can further include a first end portion, a second end portion opposite the first end portion, and a damping region between the first and second end portions. The distance between the outer surface and the inner surface of the damping member can be greater at the damping region than at either of the first or second end portions. When blood flows through the damping member during systole, the damping member absorbs a portion of the pulsatile energy of the blood to reduce the magnitude of the pulse pressure transmitted to a portion of the blood vessel distal to the damping device. Specific details of several damping devices are described below with reference to Figures 2A-19B.

[0011] With regard to the terms "distal" and "proximal" within this description, unless otherwise specified, the terms can reference a relative position of the portions of a damping device and / or an associated delivery device with reference to an operator, direction of blood flow through a vessel, and / or a location in the vasculature. For example, in referring to a delivery catheter suitable to deliver and position various damping devices described herein, "proximal" refers to a position closer to the operator of the device or an incision into the vasculature, and "distal" refers to a position that is more distant from the operator of the device or further from the incision along the vasculature (e.g., the end of the catheter).

[0012] As used herein, "artery" and "arteries that supply blood to the brain," include any arterial blood vessel (or portion thereof) that provides oxygenated blood to the brain. For example, "arteries" or "arteries that supply blood to the brain" can include the ascending aorta, the aortic arch, the brachiocephalic trunk, the right common carotid artery, the left common carotid artery, the left and right internal carotid arteries, the left and right external carotid arteries, and / or any branch and / or extension of any of the arterial vessels described above.I. Selected Intravascular Damping Devices

[0013] Figures 2A and 2B are a front view and a front cross-sectional view, respectively, of a damping device 100 shown in an expanded or deployed state. Figure 2C is a front view of the damping device 100 in a deployed state positioned in a carotid artery CA (e.g., the left or right carotid artery). Referring to Figures 2A-2C together, the damping device 100 includes a flexible, viscoelastic damping member 102 (e.g., a cushioning member) and anchoring members 104 (identified individually as first and second anchoring members 104a and 104b, respectively). The damping member 102 includes an undulating or hourglass-shaped sidewall having an outer surface 115 and an inner surface 113 (Figures 2B and 2C) that defines a lumen 114 configured to receive blood flow therethrough. The outer surface 115 is separated from the inner surface 113 by a distance t (Figure 2B). The damping member 102 has a length L, a first end portion 106, and a second end portion 108 opposite the first end portion 106 along its length L, and a damping region 120 between the first end portion 106 and the second end portion 108. In the damping devices shown in Figures 2A-2C, the distance t between the outer and inner surfaces 115 and 113 varies along the length L of the damping member 102 when it is in a deployed, relaxed state. In some damping devices, the distance t between the outer and inner surfaces 115 and 113, on average, can be greater at the damping region 120 than at either of the first or second end portions 106, 108. In other damping devices, the damping member 102 can have other suitable shapes (for example, Figures 2E-2G), sizes, and / or configurations. For example, as shown in Figure 2D, the distance t between the outer and inner surfaces 115 and 113 may be generally constant along the length of the damping member 102 and / or the damping region 120 when the damping member 102 is in a deployed, relaxed state.

[0014] The damping member 102 shown in Figures 2A-2C is a solid piece of material that is molded, extruded, or otherwise formed into the desired shape. The damping member 102 can be made of a biocompatible, compliant, viscoelastic material that is configured to deform in response to local fluid pressure in the artery. As the damping member 102 deforms, the damping member 102 absorbs a portion of the pulse pressure. The damping member 102, for example, can be made of a biocompatible synthetic elastomer, such as silicone rubber (VMQ), Tufel I and Tufel III elastomers (GE Advanced Materials, Pittsfield, MA), Sorbothane ®< (Sorbothane, Incorporated, Kent, OH), and others. The damping member 102 can be flexible and elastic such that the inner diameter ID of the damping member 102 at the damping region 120 increases as a systolic pressure wave propagates through the damping region 120. For example, a systolic pressure wave may push the inner surface 113 radially outwardly, thus forcing a portion of the outer surface 115 to also deform radially outwardly. Additionally, the damping member 102 can also optionally be compressible such that the distance t between the inner and outer surfaces 115 and 113 decreases to further open the inner diameter ID of the damping region 120 as the systolic pressure wave engages the damping region 120. For example, a systolic pressure wave may push the inner surface 113 radially outwardly while the contour of the outer surface 115 remains generally unaffected.

[0015] In the damping devices shown in Figures 2A-2C, the anchoring members 104a-104b individually comprise a generally cylindrical structure configured to expand from a low-profile state to a deployed state in apposition with the blood vessel wall. Each of the anchoring members 104a-b can be a stent formed from a laser cut metal, such as a superelastic material (e.g., Nitinol) or stainless steel. All or a portion of each of the anchoring members can include a radiopaque coating to improve visualization of the device during delivery, and / or the anchoring members may include one or more radiopaque markers. In other damping devices, the individual anchoring members 104a-104b can comprise a mesh or woven (e.g., a braid) construction in addition to or in place of a laser cut stent. For example, the individual anchoring members 104a-104b can include a tube or braided mesh formed from a plurality of flexible wires or filaments arranged in a diamond pattern or other configuration. In some damping devices, all or a portion of one or both of the anchoring members 104a-104b can be covered by a graft material (such as Dacron) to promote sealing with the vessel wall. Additionally, all or a portion of one or both anchoring members can include one or more biomaterials.

[0016] In the damping devices shown in Figures 2A-2B, the anchoring members 104a-104b are positioned around the damping member 102 at the first and second end portions 106, 108, respectively. As such, in this damping device, the outer diameter OD of the damping member 102 is less than the inner diameter of the anchoring members 104a-104b. Also in the damping device shown in Figures 2A-2B, the anchoring members 104a-104b are positioned around the damping member 102 only at the first and second end portions 106, 108, respectively. As such, in several damping devices, the damping region 120 of the damping member 120 is not surrounded by a stent-like structure or braided material. In other damping devices, the anchoring members 104 and damping member 102 may have other suitable configurations. For example, the anchoring members 104a-104b may be positioned at other locations along the length L of the damping member 102, though not along the full length of the damping member 102. Also, in some damping devices, all or a portion of one or both anchoring members 104a-104b may be positioned radially outwardly of all or a portion of the damping member 102. Although the damping device 100 shown in Figures 2A-2B includes two anchoring members 104a-104b, the damping device 100 can also have more or fewer anchoring members (e.g., one anchoring member, three anchoring members, four anchoring members, etc.).

[0017] In some damping devices, a biocompatible gel or liquid may be located between the wall of the artery A and the outer surface 115 of the damping member 102 to prevent the ingression of blood into the void defined between the first anchoring member 104a, the second anchoring member 104b, the damping member 102, and the inner wall of the artery CA. Alternatively, air or another gas may be located between the internal wall of the carotid artery CA and the damping member 102 to prevent the ingression of blood into the void.

[0018] Figure 3A is a front cross-sectional view of another damping device 100'. The damping device 100' shown in Figure 3A is similar to the damping device 100 shown in Figures 2A-2C, and like reference numbers refer to like components in Figures 2A-2C and Figure 3A. As shown in Figure 3A, the damping device 100' includes an inner damping member 102 and an outer layer 130 surrounding the damping member 102. The outer layer 130 has an outer surface 131 and, in the damping device shown in Figure 3A, the first and second anchoring members 104a-b are attached to the outer surface 131. At least along the damping region 120, the outer layer 130 is spaced apart from the outer surface 115 of the damping member 102 to form a chamber 132. The chamber 132 can be at least partially filled with a fluid, such as a gas, liquid, or gel. The device 100' has a length L and a distance d between the outer surface 131 of the outer layer 130 and the inner surface 113 of the damping member 102. Along the damping region 120, the distance d between the outer and inner surfaces 131 and 113 increases then decreases in a radial direction when the damping member 102 is in a deployed, relaxed state. On average, the distance d between the outer surface 131 and the inner surface 113 of the damping member 102 is greater at the damping region 120 than at either of the first or second end portions 106, 108. As a result, the diameter ID of the lumen 114 varies along the length L. For example, the outer surface 131 and / or the outer layer 130 can be generally cylindrical in an unbiased state, and the inner surface 113 and / or the damping member 102 can have an undulating or hourglass shape. In other damping devices, the outer surface 131 and / or the outer layer 130 can be other suitable shapes, and the inner surface 113 and / or the damping member 102 can be other suitable shapes (Figures 3B-3D).

[0019] In some damping devices, instead of the damping device 100' having a separate outer layer 130, the damping member 102 can be molded, formed, or otherwise extruded to enclose a cavity. For example, as shown in Figures 3B-3D, the damping member 102' can include an inner layer 116, an outer layer 118, and a cavity 119 therebetween. The cavity 119 can be at least partially filled with a fluid, such as a gas, liquid, or gel.

[0020] Figures 4A and 4B are a front view and a front cross-sectional view, respectively, of another damping device 200 shown in an expanded or deployed state. Figure 4C is a front cross-sectional view of the damping device 200 in a deployed state positioned in a carotid artery (e.g., the left or right carotid artery). Referring to Figures 4A-4C together, the damping device 200 includes a flexible, viscoelastic damping member 202 (e.g., a cushioning member) and anchoring members 204 (identified individually as first and second anchoring members 204a-204b, respectively). As shown in Figures 4B and 4C, the damping member 202 includes a generally tubular sidewall having a cylindrical outer surface 210 and an inner surface 212 that defines a lumen 214 configured to receive blood flow therethrough. The outer surface 210 is separated from the inner surface 212 by a distance t (Figure 4B). The damping member 202 has a length L, a first end portion 206, and a second end portion 208 opposite the first end portion 206 along its length L, and a damping region 220 between the first end portion 206 and the second end portion 208. Along the damping region 220, the distance t between the outer and inner surfaces 210 and 212 increases then decreases in a radial direction when the damping member 202 is in a deployed, relaxed state. On average, the distance t between the outer and inner surfaces 210 and 212 of the damping member 202 is greater at the damping region 220 than at either of the first or second end portions 206, 208. As a result, the inner diameter ID of the damping member 202 varies along its length L relative to the outer diameter OD of the damping member 202. For example, the outer surface 210 can be generally cylindrical in an unbiased state, and the inner surface 212 can have an undulating or hourglass shape. As described in greater detail below with respect to Figures 9A-9F, the damping member 202 can have other suitable shapes, sizes, and / or configurations.

[0021] The damping member 202 shown in Figures 4A-4C is a solid piece of material that is molded, extruded, or otherwise formed into the desired shape. The damping member 202 can be made of a biocompatible, compliant, viscoelastic material that is configured to deform in response to local fluid pressure in the artery. As the damping member 202 deforms, the damping member 202 absorbs a portion of the pulse pressure. The damping member 202, for example, can be made of a biocompatible synthetic elastomer, such as silicone rubber (VMQ), Tufel I and Tufel III elastomers (GE Advanced Materials, Pittsfield, MA), Sorbothane ®< (Sorbothane, Incorporated, Kent, OH), and others. The damping member 202 can be flexible and elastic such that the inner diameter ID of the damping member 202 at the damping region 220 increases as a systolic pressure wave P (Figure 4D) propagates through the damping region 220. For example, as shown schematically in the isolated, cross-sectional view of a portion of a damping member 202 before and during deformation (damping member 202', shown in dashed lines) in Figure 4D, the systolic pressure wave P may push the inner surface 212' radially outwardly, thus forcing a portion of the outer surface 210' to also deform radially outwardly. Additionally, the damping member 202 can also optionally be compressible such that the distance t between the inner and outer surfaces 210 and 212 decreases to further open the inner diameter ID of the damping region 220 as the systolic pressure wave P engages the damping region 220. For example, as shown schematically in the isolated, cross-sectional view of a portion of a damping member 202 before and during deformation (damping member 202', shown in dashed lines) in Figure 4E, the systolic pressure wave P may push the inner surface 212' radially outwardly while the contour of the outer surface 210' remains generally unaffected.

[0022] In the damping device shown in Figures 4A-4C, the anchoring members 204a-204b individually comprise a generally cylindrical structure configured to expand from a low-profile state to a deployed state in apposition with the blood vessel wall. Each of the anchoring members 204a-b can be a stent formed from a laser cut metal, such as a superelastic material (e.g., Nitinol) or stainless steel. All or a portion of each of the anchoring members can include a radiopaque coating to improve visualization of the device during delivery, and / or the anchoring members may include one or more radiopaque markers. In other damping devices, the individual anchoring members 204a-204b can comprise a mesh or woven (e.g., a braid) construction in addition to or in place of a laser cut stent. For example, the individual anchoring members 204a-204b can include a tube or braided mesh formed from a plurality of flexible wires or filaments arranged in a diamond pattern or other configuration. In some damping devices, all or a portion of one or both of the anchoring members 204a-204b can be covered by a graft material (such as Dacron) to promote sealing with the vessel wall.

[0023] In the damping device shown in Figures 4A-4B, the anchoring members 204a-204b are positioned around the damping member 202 at the first and second end portions 206, 208, respectively. As such, in this damping device, the outer diameter OD (Figure 4A) of the damping member 202 is less than the inner diameter of the anchoring members 204a-204b. Also in the damping device shown in Figures 4A-4B, the anchoring members 204a-204b are positioned around the damping member 202 only at the first and second end portions 206, 208, respectively. As such, in several damping devices, the damping region 220 of the damping member 220 is not surrounded by a stent-like structure or braided material. In other damping devices, the anchoring members 204a-204b and damping member 202 may have other suitable configurations. For example, the anchoring members 204a-204b may be positioned at other locations along the length L of the damping member 202, though not along the full length of the damping member 202. Also, in some damping devices, all or a portion of one or both anchoring members 204a-204b may be positioned radially outwardly of all or a portion of the damping member 202. Although the damping device 200 shown in Figures 4A-4B includes two anchoring members 204a-204b, the damping device 200 can also have more or fewer anchoring members (e.g., one anchoring member, three anchoring members, four anchoring members, etc.).

[0024] In some damping devices, one or both of the anchoring members 204a-204b can optionally include one or more fixation elements 205 (Figure 4B) configured to engage the blood vessel wall. The fixation elements 205 can include, for example, one or more hooks or barbs that, in the deployed state, extend outwardly away from the corresponding frames of the anchoring member 204a-204b to penetrate the vessel wall at the treatment site. In these and other damping devices, one or more of the fixation elements can be atraumatic. In Figure 5, the damping device 200A does not include a stent-type or braid-type anchoring member, but rather the frame of the anchoring members 204 can be one or more expandable rings 230. For example, the damping device 200 can include two rings 230, each attached to a respective end portion 206 and 208, and the plurality of fixation elements 205 can extend outwardly from the rings 230. In the damping device 200B shown in Figure 6, the anchoring members 204 are integral portions of the end portions 206, 208, such as thick wall portions 240a-b of the damping member 202 that extend radially outward from the outer wall of the damping region 220, instead of separate metal or polymeric components. In this damping device, the fixation elements 205 can extend outwardly from integral anchoring members 240a-b at the first and second end portions 206, 208 of the damping member 202. When the damping device 200 is in a deployed state, the fixation elements 205 extend outwardly away from the outer surface of the damping member 202 to engage vessel wall tissue. In yet other damping devices, the fixation elements 205 can extend outwardly from the outer surface 210 of the damping member 202, as shown in the damping device 200C of Figure 7.

[0025] Figures 8A-8E illustrate a method for positioning a damping device at a treatment location within an artery A (such as the left and / or right common carotid artery CA). Although Figures 8B-8E depict the damping device 200 shown in Figures 4A and 4B, the methods and systems described with respect to Figures 8A-8E can be utilized for any of the damping devices 100, 100', 200, 200A, 200B, and 200C described with respect to Figures 2A-7 and Figures 9A-9F.

[0026] As shown in Figure 8A, a guidewire 602 may first be advanced intravascularly to the treatment site from an access site, such as a femoral or a radial artery. A guide catheter 604 may then be advanced along the guidewire 602 until at least a distal portion of the guide catheter 604 is positioned at the treatment site. In these and other damping devices, a rapid-exchange technique may be utilized. In some damping devices, the guide catheter 604 may have a pre-shaped or steerable distal end portion to direct the guide catheter 604 through one or more bends in the vasculature. For example, the guide catheter 604 shown in Figures 8A-8E has a curved distal end portion configured to navigate through the ascending aorta AA and preferentially bend or flex at the left and / or right common carotid artery A to direct the guide catheter 604 into the artery A.

[0027] Image guidance, e.g., computed tomography (CT), fluoroscopy, angiography, intravascular ultrasound (IVUS), optical coherence tomography (OCT), or another suitable guidance modality, or combinations thereof, may be used to aid the clinician's positioning and manipulation of the damping device 200. For example, a fluoroscopy system (e.g., including a flat-panel detector, x-ray, or c-arm) can be rotated to accurately visualize and identify the target treatment site. In other damping devices, the treatment site can be determined using IVUS, OCT, and / or other suitable image mapping modalities that can correlate the target treatment site with an identifiable anatomical structure (e.g., a spinal feature) and / or a radiopaque ruler (e.g., positioned under or on the patient) before delivering the damping device 200. Further, in some damping devices, image guidance components (e.g., IVUS, OCT) may be integrated with the delivery catheter and / or run in parallel with the delivery catheter to provide image guidance during positioning of the damping device 200.

[0028] Once the guide catheter 604 is positioned at the treatment site, the guidewire 602 may be withdrawn. As shown in Figures 8B and 8C, a delivery assembly 610 carrying the damping device 200 may then be advanced distally through the guide catheter 604 to the treatment site. In some damping devices, the delivery assembly 610 includes an elongated shaft 612 having an atraumatic distal tip 614 (Figure 8B) and an expandable member 616 (e.g., an inflatable balloon, an expandable cage, etc.) positioned around a distal portion of the elongated shaft 612. The damping device 200 can be positioned around the expandable member 616. As shown in Figure 8D, expansion or inflation of the expandable member 616 forces at least a portion of the damping device 200 radially outwardly into contact with the arterial wall. In some damping devices, the delivery assembly 610 can include a distal expandable member for deploying a distal portion of the damping device 200, and a proximal expandable member for deploying a proximal portion of the damping device 200. In other damping devices, the entire length of the damping device 200 may be expanded at the same time by deploying one or more expandable members.

[0029] In some procedures the clinician may want to stretch or elongate the damping device 200 before deploying the proximal second anchoring member 204b against the arterial wall. To address this need, the delivery assembly 610 and / or damping device 200 can optionally include a tensioning mechanism for pulling or providing a tensile stress on the second anchoring member 204b, thereby increasing the length of the damping member 202 and / or a distance between the first and second and anchoring members 204a, 204b. For example, as shown in Figure 8C, the second anchoring member 204b can include one or more coupling portions 205 (e.g., one or more eyelets extending proximally from the anchoring frame) and one or more coupling members 618 (e.g., a suture, a thread, a filament, a tether, etc.) extending between the second anchoring member 204b and a proximal portion (not shown) of the delivery assembly 610 (e.g., a handle). The coupling members 618 are configured to releasably engage the coupling portions 205 to mechanically couple the second anchoring member 204b to a proximal portion of the delivery assembly 610. A clinician can apply a tensile force to the coupling member 618 to elongate the damping device 200 and / or damping member 202 and adjust the longitudinal position of the second anchoring member 204b. Once the second anchoring member 204b is positioned at a desired longitudinal position relative to the first anchoring member 204a and / or the local anatomy, the second anchoring member 204b can be expanded into contact with the arterial wall (e.g., via deployment of one or more expandable members). Before, during, and / or after expansion of the second anchoring member 204b, the coupling member(s) 618 may be disengaged from the second anchoring member 204b. For example, in some damping devices, the operator can force the coupling members 618 to break along their lengths by applying a tensile force that is less than a force that would be required to dislodge one or both of the first and second anchoring members 204a, 204b. Once disengaged from the second anchoring member 204b and / or the damping device 200, the coupling member(s) 618 can then be withdrawn from the treatment site through the guide catheter 604.

[0030] In other damping devices, other tensioning mechanisms may be utilized. For example, the damping device 200 may include a releasable clasp, ring, or hook which is selectively releasable by the operator. The clasp, ring or hook may be any type that permits securement of the thread to the second anchoring member 204b, and which can be selectively opened or released to disengage the thread from the second anchoring member 204b. The releasing can be controlled by the clinician from an extracorporeal location. Although the tensioning mechanism is described herein with respect to the second anchoring member 204b, it will be appreciated that other portions of the damping device 200 and / or the delivery assembly 610 (such as the first anchoring member 204a) can be coupled to a tensioning mechanism.

[0031] In certain damping devices, the damping member 202 and / or individual anchoring members 204a, 204b may be self-expanding. For example, the delivery assembly 610 can include a delivery sheath (not shown) that surrounds and radially constrains the damping device 200 during delivery to the treatment site. Upon reaching the treatment site, the delivery sheath may be at least partially withdrawn or retracted to allow the damping member 202 and / or the individual anchoring members 204a, 204b to expand. In some damping devices, expansion of the anchoring members 204 may drive expansion of the damping member 202. For example, the anchoring members 204 may be fixedly attached to the damping member 202, and expansion of one or both anchoring 204 pulls or pushes (depending on the relative positioning of the damping member 202 and anchoring members 204) the damping member 202 radially outwardly.

[0032] As best shown in Figure 8C, once the damping device 200 is positioned at the treatment site (e.g., in a left or right common carotid artery), oxygenated blood ejected from the left ventricle flows through the lumen 214 of the damping member 202. As the blood contacts the damping region 220 of the damping member 202, the damping region 220 deforms to absorb a portion of the pulsatile energy of the blood, which reduces a magnitude of a pulse pressure transmitted to the portions of the artery distal to the damping device 200 (such as the more-sensitive cerebral arteries). The damping region 202 acts a pressure limiter that distributes the pressure of the systolic phase of the cardiac cycle more evenly downstream from the damping device 200 without unduly compromising the volume of blood flow through the damping device 200. Accordingly, the damping device 200 reduces the pulsatile stress on downstream portions of the arterial network to prevent or at least partially reduce the manifestations of vascular dementia and / or age-related dementia.

[0033] In some procedures, it may be beneficial to deliver multiple damping devices 200 to multiple arterial locations. For example, after deploying a first damping device 200 at a first arterial location (e.g., the left or right common carotid artery, an internal or external carotid artery, the ascending aorta, etc.), the clinician may then position and deploy a second damping device 200 at a second arterial location different than the first arterial location (e.g., the left or right common carotid artery, an internal or external carotid artery, the ascending aorta etc.). In a particular application, a first damping device is deployed in the left common carotid artery and the second damping device is deployed in the right common carotid artery. Two or more damping devices 200 may be delivered simultaneously.

[0034] In some damping devices, an additional stent of larger diameter may be placed within the vessel prior to deployment of the damping device 200 to expand the diameter of the vessel in preparation for the device. Subsequently, the damping device 200 can be deployed within the larger stent. This may assist to reduce impact on the residual diameter of the vessel, and thereby reduce impact on blood flow rate.

[0035] Figures 9A-9F are schematic cross-sectional views of several damping members. Like reference numbers refer to similar or identical components in Figures 2A-9F. In the damping device shown in Figure 9A, the inner surface 212 of the damping member 202 is curved along its entire length. The distance between the outer surface 210 and the inner surface 212 gradually increases then decreases in a distal direction. As such, the damping region 220 extends the entire length of the damping member 202. Figures 9B and 9C illustrate damping members 202 in which the inner surface 212 has a series of damping regions 220 defined by undulations in the inner surface 212. In these damping devices, the distance t increases, then decreases, then increases, then decreases, etc. in a distal direction. In Figure 9B, the damping regions 220 are generally linear, while in Figure 9C, the damping regions 220 are generally curved. Figures 9D-9E illustrate damping members 202 having damping regions 220 comprising an annular ring projecting radially inwardly into the lumen 214. One or more portions of the annular ring may flex in a longitudinal direction in response to blood flow. As shown in Figure 9F, the damping member 220 can comprise two or more opposing leaflets 221.II. Selected Resection Damping Devices

[0036] Figures 10 and 11 are schematic cross-sectional views of several damping devices. Like reference numbers refer to similar or identical components in Figures 2A-15. Figure 10, for example, shows a damping device 1000 comprising only the damping member 202. A portion of the arterial wall A may be resected, and the damping member 202 may be coupled to the open ends of the resected artery (e.g., via sutures 1002) such that the damping member 202 spans the resected portion of the artery A. In some damping devices, the damping member 202 may have a generally cylindrical shape with a constant wall thickness, as shown in Figure 11. In such damping devices, an inner diameter ID of the damping member 202 may be generally constant along the length of the damping member 202. In operation, the damping devices 1000 and 1100 shown in Figures 10 and 11 are highly flexible, elastic members that expand radially outward as the systolic pressure wave passes through the damping devices 1000 and 1100. Since the resected portions of the arterial wall A cannot limit the expansion of the damping devices 1000 and 1100, these devices can expand more than the native arterial wall A to absorb more energy from the blood flow.III. Selected Additional Damping Devices

[0037] Figures 12A-19B illustrate additional damping devices. For example, Figure 12A shows a damping device 1200 comprising a damping member 1202 coupled to anchoring members 1204a and 1204b at its proximal and distal end portions. The damping member 1202 comprises a strand 1203 having a pre-set helical configuration such that, in a deployed state, the strand 1203 forms a generally tubular structure defining a lumen extending therethrough. The tubular structure has an inner surface 1209 (Figure 12B) and an outer surface 1211. The strand 1203 may be formed of any suitable biocompatible material such as one or more elastic polymers that are configured to stretch in response to the radially outward forces exerted by the pulse wave on the helical strand. In some damping devices, the strand 1203 may additionally or alternatively include one or more metals such as stainless steel and / or a superelastic and / or shape memory alloy, such as Nitinol. In a particular damping device, the damping member 1202 may be fabricated from a recombinant human protein such as tropo-elastin or elastin.

[0038] The anchoring members 1204a and 1204b can be generally similar to the anchoring members 104a and 104b described with respect to Figures 2A-2C. The damping device 1200 may include more or fewer than two anchoring members 1204 (one anchoring member, three anchoring members, etc.) or does not include anchoring members 1204.

[0039] In the deployed state, the damping member 1202 is configured to be wrapped along the circumference of an artery that supplies blood to the brain. For example, in the damping device shown in Figure 12A, the damping member 1202 is configured to be positioned around the exterior of the artery A such that the inner surface 1209 of the damping member 1202 contacts an outer surface of the artery A (see Figure 12B). In other damping devices (not shown), the damping member 1202 is configured to be positioned around the lumen of the artery such that the outer surface 1211 of the damping member 1202 contacts an inner surface of the arterial wall.

[0040] Figure 12B is a cross-sectional side view of the damping device 1200 during transmission of a pulse wave PW through the portion of the artery A surrounded by the damping device 1200. In Figure 12B, the dashed lines A represent the artery during diastole, or when the artery is relaxed. The solid line A' represents the artery in response to a pulse wave PW traveling through the artery during systole. As shown in Figure 12B, as the wave front WF (or leading edge of the pulse wave PW) travels through the artery, the wavefront dilates the artery A at an axial location L 1 corresponding to the wavefront WF. The wavefront WF pushes the arterial wall radially outwardly against the coil, thereby radially expanding the portion R 1 of the coil axially aligned with the wave front WF. For example, in those damping devices where the strand 1203 is made of a stretchable material, such as an elastic polymer, the coil stretches along the portion R 1 to expand and accommodate the pulse wave, thereby absorbing some of the energy transmitted with the pulse wave and reducing the stress on the arterial wall. In any of the above damping devices, the portions of the coil distal or proximal the wave-affected region are forced to contract (R 2 ), thereby causing the artery to narrow relative to its relaxed diameter. This narrowing of the artery creates a temporary impedance to the pulse wave which absorbs some of the energy. Once the pulse wave has passed, the arterial wall returns to its relaxed state.

[0041] Figure 13 illustrates another damping device 1300. As shown in Figure 13, the damping device 1300 can include a damping member 1302 defined by an extravascular wrap. The damping member 1302 may be fabricated from a generally rectangular portion of a suitable bio-compatible and elastically deformable material which is configured to be wrapped around the blood vessel. Alternatively, the damping member 1302 may be initially provided having a cylindrical configuration including a longitudinal slit 1304 for receiving the vessel. The damping member 1302 may be fabricated from a synthetic such as an elastic polymer, a shape memory and / or superelastic material such as Nitinol (nickel titanium), a recombinant human protein such as tropo-elastin or elastin, and other suitable materials. As shown in Figure 13, the damping member 1302 is configured to be secured around an artery (e.g., a carotid artery) between the aortic arch and the junction where the left common carotid artery divides into the internal (IC) and external (EC) carotid arteries. It will be appreciated by those skilled in the art that the damping member 1302 may alternatively or additionally be deployed around the brachiocephalic trunk (not shown) or the right common carotid artery (not shown), or any distal branch of the aforementioned arteries, or any proximal branch of the aforementioned arteries, such as the ascending aorta. Opposing edges of the damping member 1302 can be secured to each other with a coupling device such as stitching / sutures 1310, stapling, or another coupling device such that the external diameter of the artery is reduced. In some damping devices, the coupling device can be made from an elastic material so that it can stretch to accommodate the pulse wave and absorb its energy. The elastically deformable damping member 1302 is adapted to radially expand during the systole stage and radially contract during the diastole stage. The damping member 1302 is secured such that an internal diameter of the elastically deformable material is smaller than an initial, outer diameter of the artery during a systole stage, but not smaller than an outer diameter of the artery during a diastole stage.

[0042] Figure 14 depicts another damping device 1400 for treating an arterial blood vessel. The device 1400 can be structurally similar to the damping device 1300 shown in Figure 13, with the exception that the two opposing edges of the elastically deformable damping member 1402 of Figure 14 are secured to each other using a zip-lock type coupling mechanism 1410.

[0043] Figure 15 shows another damping device 1500. The damping device 1500, includes a generally tubular anchoring member 1504 (e.g., a stent, a mesh, a braid, etc.) defining a lumen 1514 therethrough. The anchoring member may be made of a resilient, biocompatible material such as stainless steel, titanium, nitinol, etc. In some damping devices, the anchoring member 1504 is made of a shape memory and / or superelastic material. A radially outer surface of the anchoring member 1504 is configured to be positioned in apposition with an inner surface of an arterial wall. A radially inner surface of the anchoring member 1504 is lined or otherwise coated with an absorptive material 1503 (e.g., a cushioning material), such as an elastically deformable material, which is adapted to absorb shock. The lumen 1514 is configured to receive blood flow therethrough. The lumen 1514 is present when the anchoring member 1504 is radially expanded, but it may not be present in the initial, contracted configuration prior to deployment

[0044] Some not shown damping devices can be a biocompatible gel which is injected around a portion of the left or right carotid artery or the brachiocephalic trunk. The gel increases the external pressure acting on the artery and thus reduces the external diameter of the artery. As blood pressure increases within the artery, the gel elastically deforms, such that the artery radially expands during the systole stage and radially contracts during the diastole stage.

[0045] Figure 16A is a perspective, cut-away view of a damping device 1600 in accordance with the present technology in a deployed, relaxed state. Figure 16B is a cross-sectional view of the damping device 1600 positioned in an artery A during transmission of a pulse wave PW through the portion of the artery A surrounded by the damping device 1600. Referring to Figures 16A and 16B together, the damping device 1600 includes a damping member 1602 and a structural member 1604 coupled to the damping member 1602. In Figure 16A, a middle portion of the structural member 1604 has been removed to show features of the structure of the damping member 1602. As shown in Figure 16A, the damping device 1600 can have a generally cylindrical shape in the deployed, relaxed state. The damping device 1600 may be configured to wrap around the circumference of the artery with opposing longitudinal edges (not shown) secured to one another via sutures, staples, adhesive, and / or other suitable coupling devices. Alternatively, the damping device 1600 can have a longitudinal slit for receiving the artery therethrough. The foregoing extravascular damping device 1600 is configured to be positioned around the circumference of the artery A so that the inner surface 1612 (Figure 16B) is adjacent and / or in contact with the outer surface of the arterial wall.

[0046] The structural member 1604 may comprise a mesh or woven (e.g., a braid) construction in addition to or in place of a laser cut stent. For example, the structural member 1604 can include a tube or braided mesh formed from a plurality of flexible wires or filaments arranged in a diamond pattern or other configuration. In some damping devices, all or a portion of the structural member 1604 can be covered by a graft material (such as Dacron) to promote sealing with the vessel wall. Additionally, all or a portion of the structural member 1604 can include one or more biomaterials.

[0047] In the damping device shown in Figures 16A and 16B, the structural member 1604 is positioned radially outwardly of the damping member 1602 and extends along the entire length of the damping member 1602 (though a middle portion of the structural member 1604 is cut-away in Figure 16A for illustrative purposes only). In other damping devices, the structural member 1604 and the damping member 1602 may have other suitable configurations. For example, the damping device 1600 can include more than one structural member 1604 (e.g., two structural members, three structural members, etc.). Additionally, in some damping devices, the structural member(s) 1604 may extend along only a portion of the damping member 1602 such that a portion of the length of the damping member 1602 is not surrounded and / or axially aligned with any portion of the structural member 1604.

[0048] In the embodiment shown in Figures 16A and 16B, the damping member 1602 includes a proximal damping element 1606a and a distal damping element 1606b. The damping member 1602 may further include optional channels 1608 extending between the proximal and distal damping elements 1606a, 1606b. The channels 1608, for example, can extend in a longitudinal direction along the damping device 1600 and fluidly couple the proximal damping element 1606a to the distal damping element 1606b. The damping member 1602 includes an abating substance 1610 configured to deform in response to fluid stress (such as blood flow), thereby absorbing at least a portion of the stress. As best shown in Figure 16B, in one embodiment, the abating substance 1610 includes a plurality of fluid particles F (only one fluid particle labeled) contained in the proximal damping element 1606a, distal damping element 1606b, and channel(s) 1608. As used herein, the term "fluid" refers to liquids and / or gases, and "fluid particles" refers to liquid particles and / or gas particles. In some embodiments, the damping member 1602 is a gel, and the plurality of fluid particles F are dispersed within a network of solid particles. In other embodiments, the damping member 1602 may include only fluid particles F (e.g., only gas particles, only liquid particles, or only gas and liquid particles) contained within a flexible and / or elastic membrane that defines the proximal damping member 1606a, the distal damping member 1606b, and the channel(s) 1608. The viscosity and / or composition of the abating substance 1610 may be the same or may vary along the length and / or circumference of the damping member 1602.

[0049] In the embodiment shown in Figures 16A and 16B, the channels 1608 have a resting radial thickness t r and circumferential thickness t c (Figure 16A) that is less than the resting radial thickness t r and circumferential thickness t c , respectively, of the proximal and distal damping elements 1606a, 1606b. As best shown in Figure 16A, in some embodiments the proximal and distal damping elements 1606a and 1606b may extend around the full circumference of the damping device 1600 and the channels 1608 may extend around only a portion of the circumference of the damping device 1600. In other embodiments, the channels 1608 can have a resting radial thickness t r that is generally the same as that of the proximal and distal damping elements 1606a, 1606b (see damping elements 1906a-c and channels 1908 in Figures 19A and 19B) and / or a resting circumferential thickness t c that is generally the same as that of the proximal and distal damping elements 1606a, 1606b.

[0050] Referring to Figure 16B, when a pulse wave PW traveling through the artery A applies a stress at a first axial location L 1 along the length of the damping member 1602 (e.g., at wavefront WF), at least a portion of the fluid particles move away from the first axial location L 1 to a second axial location L 2 along the length of the damping member 1602. As such, at least a portion of the fluid particles are redistributed along the length of the damping member 1602 such that the inner diameter ID of the damping member 1602 increases at the first axial location L 1 while the inner diameter ID decreases at another axial location (e.g., L 2 ). For example, as the wavefront WF passes through the proximal portion 1600a of the device 1600, the portion of the artery A aligned with the wavefront WF dilates, thereby applying a stress to the proximal damping element 1606a and forcing at least some of the fluid particles in the proximal damping element 1606a to move distally within the damping member 1602. At least some of the displaced fluid particles are forced through the channel(s) 1608 and into the distal damping element 1606b, thereby increasing the volume of the distal damping element 1606b and decreasing the inner diameter ID of the damping device 1600 at the distal portion 1600b. The decreased inner diameter ID of the damping device 1600 provides an impedance to the blood flow that absorbs at least a portion of the energy in the pulse wave when the blood flow reaches the distal damping member 1606b. As the wavefront WF then passes through the distal portion 1600b of the device 1600, the portion of the artery A aligned with the wavefront WF dilates, thereby applying a stress to the distal damping element 1606b and forcing at least some of the fluid particles currently in the distal damping element 1606b to move proximally within the damping member 1602. At least some of the displaced fluid particles are forced through the channel(s) 1608 and into the proximal damping element 1606a, thereby increasing the volume of the proximal damping element 1606a and decreasing the inner diameter ID of the device 1600 at the proximal portion 1600a. Movement of the fluid particles and / or deformation of the damping member 1602 in response to the pulse wave absorbs at least a portion of the energy carried by the pulse wave, thereby reducing the stress on the arterial wall distal to the device.

[0051] When the damping member 1602 deforms in response to the pulse wave, the shape of the structural member 1604 may remain generally unchanged, thereby providing the support to facilitate redistribution of the fluid particles within and along the damping member 1602. The structural member 1604 may also deform in response to the local fluid stress.

[0052] Figure 17A is a perspective view of another damping device 1700. Figure 17B is a cross-sectional view of the damping device 1700 positioned in an artery A during transmission of a pulse wave PW through the portion of the artery A surrounded by the damping device 1700. The damping device 1700 can include a structural member 1704 and a damping member 1702. The structural member 1704 can be generally similar to the structural member 1604 shown in Figures 16A and 16B. The damping member 1702 is defined by a single chamber 1705 including an abating substance 1610 and a plurality of baffles 1720 that separate the chamber 1705 into three fluidically-coupled compartments 1706a, 1706b, and 1706c. The baffles 1720 extend only a portion of the radial thickness of the damping member 1702, thereby leaving a gap G between the end of the baffles 1720 and an inner wall 1722 of the damping member 1702. The damping device 1700 can include more or fewer compartments (e.g., a single, tubular compartment (no baffles), two compartments, four compartments, etc.). Moreover, the baffles 1720 may extend around all or a portion of the circumference of the damping member 1702.

[0053] Figure 18A is a perspective view of another damping device 1800, and Figure 18B is a front view of the damping device 1800, shown in a deployed state positioned around an artery A. Referring to Figures 18A-18B together, the damping device 1800, in a deployed, relaxed state, includes a generally tubular sidewall 1805 that defines a lumen. The damping device 1800 can be formed of a generally parallelogram-shaped element that is wrapped around a mandrel in a helical configuration and heat set. The damping device 1800 can have other suitable shapes and configurations in the unfurled, non-deployed state. As shown in Figure 18B, in the deployed state, the damping device 1800 is configured to be wrapped helically along or around the circumference of an artery supplying blood to the brain. Opposing longitudinal edges 1807 of the damping device 1800 come together in the deployed state to form a helical path along the longitudinal axis of the artery A. The damping device 1800 can include any of the coupling devices described with respect to Figures 13-15 to secure all or a portion of the opposing longitudinal edges to one another.

[0054] As best shown in Figure 18A, the sidewall 1805 of the damping device 1800 includes a structural member 1804 and a damping member 1802. The structural member 1804 can be generally similar to the structural member 1604 shown in Figures 16A and 16B, except the structural member 1804 of Figures 18A and 18B has a helical configuration in the deployed state. The damping member 1802 can be generally similar to any of the damping members described herein, especially those described with respect to Figures 13-17B and 19A and 19B. In the damping device shown in Figures 18A and 18B, the damping member 1802 is positioned radially inwardly of the structural member 1804 when the damping device 1800 is in the deployed state. The damping member 1802 may be positioned radially outwardly of the structural member 1804 when the damping device 1800 is in the deployed state.

[0055] The damping device 1800 may be configured to wrap around the circumference of the artery A so that the inner surface 1812 (Figure 18A) is adjacent and / or in contact with the outer surface of the arterial wall. The damping device 1800 can be configured to be positioned intravascularly (e.g., within the artery lumen) such that an outer surface of the damping device 1800 is adjacent and / or in contact with the inner surface of the arterial wall. In such intravascular damping devices, the inner surface 1812 of the damping member 1802 is adjacent or directly in contact with blood flowing through the artery A.

[0056] Figures 19A and 19B are perspective and top views, respectively, of a damping device 1900 that can define one variant of the damping device 1800 shown in Figures 18A and 18B. In Figures 19A and 19B, the damping device 1900 is shown in an unfurled, non-deployed state. The damping device 1900 includes a damping member 1902 having a plurality of chambers 1906a, 1906b, 1906c spaced apart along a longitudinal dimension of the damping device 1900 in the unfurled state. The chambers 1906a, 1906b, 1906c may be fluidly coupled by channels 1908 extending between adjacent chambers. The damping device 1900 can thus operate in a manner similar to the damping device 1600 where an abating substance (not shown in Figures 19A and 19B) in the chambers 1906a-c moves through the channels 1908 to inflated / deflate individual chambers in response to a pressure wave traveling through the blood vessel. The displacement of the abating substance within the chambers 1906a-c attenuates the energy of the pulse wave to reduce the impact of the pulse wave distally of the damping device 1900.IV. Conclusion

[0057] Although many of the damping devices are described above with respect to systems, devices, and methods for treating and / or slowing the progression of vascular and / or age-related dementia via intravascular methods, the technology is applicable to other applications and / or other approaches, such as surgical implantation of one or more damping devices and / or treatment of blood vessels other than arterial blood vessels supplying blood to the brain, such as the abdominal aorta. Any appropriate site within a blood vessel may be treated including, for example, the ascending aorta, the aortic arch, the brachiocephalic artery, the right subclavian artery, the left subclavian artery, the left common carotid artery, the right common carotid artery, the internal and external carotid arteries, and / or branches of any of the foregoing. A person of ordinary skill in the art, therefore, will understand that the invention is defined in the claims.

Claims

1. A device for treating or slowing the effects of dementia, comprising: a damping member (1802) and a structural element (1804) coupled to the damping member (1802); the damping member (1804) including an abating substance having a plurality of fluid particles (F) wherein the fluid particles are axially movable along at least a part of a length of the damping member, the damping member (1802) being configured to be positioned along a circumference of an artery at a treatment site along a length of the artery, wherein, when the damping member (1802) is in a deployed configuration and positioned at the treatment site, deformation of the damping member and redistribution of at least a portion of the fluid particles occurs in response to a pulse wave traveling in the artery, and the shape of the structural member remains unchanged; wherein, in the deployed state, the damping member (1802) is configured to wrap around at least a portion of the circumference of the artery, and wherein, in the deployed state, the structural element (1804) has a pre-set helical configuration; wherein the damping member includes a slit along its length; and characterised in that the device further comprises cooperating coupling arrangements located on or near opposing edges of the slit, to allow the edges to be joined together once the damping member has been fitted around the portion of the circumference of the artery.

2. The device of claim 1 wherein the fluid particles (F) are contained within a flexible member and the particles (F) may move along the length of the damping member (1802) within the flexible member.

3. The device of claim 2 wherein the flexible member may, at at least some locations along the length of the damping member (1802), be deformed radially with respect to the damping member (1802).

4. The device of any one of claims 1-3 wherein the abating substance includes a liquid.

5. The device of any one of claims 1-4 wherein the abating substance includes a gas.

6. The device of any one of claims 1-5 wherein the abating substance includes a gel.

7. The device of any one of claims 1-6 wherein the damping member (1802), in the deployed configuration, is configured to be positioned in apposition with an outer surface of the arterial wall.

8. The device of any one of claims 1-7 wherein the damping member (1802), in the deployed configuration, is configured to be positioned around the arterial wall such that an inner surface of the damping member (1802) is adjacent and / or in contact with the outer surface of the arterial wall.

9. The device of any one of claims 1-8 wherein the damping member (1802) has a low profile configuration and a deployed configuration.