Device and method for altering blood flow characteristics in a blood vessel

Abstract

A device (15, 50, 55, 60, 100, 200) for altering blood flow characteristics within a blood vessel (20), comprising: a cuff (10) configured to be surgically placed around a portion of the blood vessel (20); and a first pad (40) disposed on an interior wall of the cuff (10), wherein the pad (40) locally reduces a cross-sectional area of ​​a passageway (25) extending through the cuff (10) and / or defines a non-linear passageway (25) within the cuff (10).

Description

[Technical Field]

[0001] The present disclosure relates to devices and methods for altering blood flow characteristics in a blood vessel, particularly the carotid artery, but which may be any blood vessel (artery or vein). In particular, the devices and methods are intended to prevent or at least reduce the risk of cognitive decline. However, those skilled in the art will recognize that the present invention may be used in other medical applications. [Background technology]

[0002] The heart supplies the body with oxygenated blood through a network of interconnected branching arteries that begin with the aorta, the largest artery in the body. As shown in Figure 1, a schematic diagram of the heart and selected arteries, the portion of the aorta closest to the heart is divided into three regions: the ascending aorta (where the aorta first leaves the heart and extends upward), the aortic arch, and the descending aorta (where the aorta extends downward). Three major arteries branch off from the aorta along the aortic arch: the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery.

[0003] The brachiocephalic trunk extends away from the aortic arch and then divides into the right common carotid artery, which supplies oxygenated blood to the head and neck, and the right subclavian artery, which supplies blood primarily to the right arm. The left common carotid artery extends away from the aortic arch and supplies blood to the head and neck. The left subclavian artery extends away from the aortic arch and supplies blood primarily to the left arm. The right and left common carotid arteries then each branch into separate internal and external carotid arteries.

[0004] The descending aorta extends downward to define the descending thoracic aorta, then the abdominal aorta, which then branches into the left and right iliac arteries. Various organs of the body are supplied by arteries that join and are supplied by the descending aorta.

[0005] During the systole phase of the heartbeat, contraction of the left ventricle forces blood into the ascending aorta, increasing pressure within the arteries (known as systolic pressure). The volume of blood ejected from the left ventricle creates a pressure wave, known as a pulse wave, which propagates through the arteries, propelling the blood. The pulse wave causes the arteries to dilate. When the left ventricle relaxes (during the diastole phase of the heartbeat), pressure within the arterial system decreases (known as diastolic pressure), causing the arteries to constrict. This is characterized by a series of forward and backward compression waves and forward and backward relaxation waves.

[0006] The difference between systolic and diastolic blood pressure is the "pulse pressure," which generally depends on, among other things, the magnitude of the contractile force exerted by the heart, heart rate, peripheral vascular resistance, and diastolic "run-off" (e.g., blood flowing through a pressure gradient from arteries to veins). High-flow organs, such as the brain, are particularly sensitive to excessive pressure and blood flow pulsatility. Other organs, such as the kidneys, liver, and spleen, can also be damaged over time by excessive pressure and blood flow pulsatility.

[0007] To ensure a relatively consistent flow of blood to these sensitive organs, arterial vessel walls expand and contract in response to pressure waves, absorbing some of the pulse wave energy. However, as the vasculature ages, the arterial walls lose elasticity, thereby increasing pulse wave velocity and wave reflection through the arterial vasculature.

[0008] Arteriosclerosis impairs the ability of the carotid arteries and other large arteries to dilate and attenuate blood flow pulsatility, thereby increasing systolic and pulse pressure. Thus, as arterial walls stiffen over time, the arteries transmit excessive forces to distal branches of the arterial vasculature.

[0009] Research suggests that consistently high systolic pressure, pulse pressure, and / or pressure change over time (dP / dt) increase the risk of dementia, including vascular dementia (e.g., reduced blood supply to the brain or intracerebral hemorrhage, or high pulse pressure). Without being bound by theory, it is believed that high pulse pressure may be an underlying cause or aggravating factor of vascular dementia and age-related dementia (e.g., Alzheimer's disease). Therefore, the progression of vascular dementia and age-related dementia (e.g., Alzheimer's disease) may also be influenced by loss of elasticity in arterial walls and the resulting stress on cerebral blood vessels. For example, Alzheimer's disease is commonly associated with the presence of senile plaques and neurofibrillary tangles in the brain. Recent studies suggest that elevated pulse pressure, elevated systolic pressure, and / or elevated rate of pressure change (dP / dt) may, over time, cause microbleeds in the brain, which may contribute to senile plaques and neurofibrillary tangles.

[0010] Elevated pulse pressure is a hallmark of vascular aging and has recently been identified as a potential risk factor for cognitive decline and dementia due to its destructive effects on the brain's fragile microvasculature.

[0011] There are studies supporting a link between high blood pressure in midlife and cognitive decline or dementia later in life.

[0012] Blood pressure is measured regularly and is used as an indicator of the presence of various underlying diseases. However, blood pressure measurement alone cannot adequately measure cognitive decline because a patient's blood pressure can increase or fluctuate as a result of various factors unrelated to cognitive decline.

[0013] The actual cause of brain damage from high pulse pressure may be the "intensity" of the carotid pulse waves as they travel to the brain. Therefore, increased amplitude of pulse-generating waves traveling to the brain may be an important risk factor for cognitive decline later in life. Summary of the Invention [Problem to be solved by the invention]

[0014] It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages, or to provide a useful alternative. [Means for solving the problem]

[0015] In a first aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: 1. A device for altering blood flow characteristics in a blood vessel, comprising: a spiral cuff configured to be surgically placed around a portion of a blood vessel; a first abutment formation defined by an inner wall of the spiral cuff; a central spine disposed within the spiral cuff; The abutment forming portion a localized reduction in the cross-sectional area of ​​the passageway extending through the cuff; and / or The cross-sectional shape of the passageway extending through the cuff changes; and / or A non-linear path is defined within the cuff. The cuff is defined by an elastically deformable spiral coated with a compliant layer; A device is provided.

[0016] blood 1. A device for altering blood flow characteristics in a vessel, comprising: a cuff configured to be surgically placed around a portion of a blood vessel; a first contact function portion disposed on an inner wall of the cuff; The contact function portion a localized reduction in the cross-sectional area of ​​the passageway extending through the cuff; and / or A non-linear path is defined within the cuff. Device is disclosed herein.

[0017] The passageways are preferably curved about one or more axes that extend generally perpendicular to the direction of blood flow.

[0018] The first abutment formation is preferably defined by the first pad.

[0019] The device preferably further comprises a second pad and a third pad, the three pads being longitudinally separated within the cuff and spaced apart around the cuff.

[0020] The three pads are preferably equally circumferentially spaced at approximately 120 degrees to each adjacent pad.

[0021] The device preferably further comprises a second pad diametrically opposed to and axially aligned with the first pad to define a first pair of pads.

[0022] The device preferably further comprises a second pair of pads that are also diametrically opposed and axially aligned.

[0023] The first pair of pads are preferably longitudinally spaced relative to the second pair of pads to define an expansion chamber within the cuff.

[0024] The device preferably further comprises a third pair of pads that are also diametrically opposed and axially aligned.

[0025] The first pair of pads is preferably positioned adjacent the proximal end of the device and the second pair of pads is preferably positioned adjacent the distal end of the device, the first and second pairs of pads being circumferentially aligned.

[0026] The third pair of pads is preferably positioned between the first pair of pads and the second pair of pads, and further, the third pair of pads is circumferentially offset by approximately 90 degrees.

[0027] Preferably, the pad is filled with gel.

[0028] The cuff is preferably defined by a generally tubular body.

[0029] The cuff preferably has a longitudinally extending seam that allows the cuff to be placed around a blood vessel.

[0030] The seam is preferably defined by first and second longitudinally extending arms that are selectively securable to one another.

[0031] The cuff is preferably defined by an elastically deformable spiral coated with a compliant layer.

[0032] The elastically deformable helix is ​​preferably made from Nitinol™ and the compliant layer is preferably made from silicone.

[0033] The radially inner surface of the compliant layer is preferably curved such that when cut through a plane parallel to and passing through the longitudinal axis of the spiral, the cross-sectional area of ​​the compliant layer is generally "D" shaped, although it will be appreciated that a variety of shapes and dimensions can be provided along the cross-sectional length of the compliant layer.

[0034] The radially inner surface of the compliant layer preferably has at least one inwardly extending projection.

[0035] blood 1. A method of altering blood flow characteristics in a vessel, comprising: surgically placing a cuff around a portion of a blood vessel; locally altering blood flow characteristics within the vessel with one or more abutment formations disposed within the cuff; and the abutment forming portion a reduction in the cross-sectional area of ​​the passageway extending through the blood vessel; and / or the vessel is deformed to define a curved region about one or more axes extending generally perpendicular to the direction of blood flow; method is disclosed herein.

[0036] No. 2 In one embodiment, the present invention provides a method for altering blood flow characteristics within a blood vessel. 1. A method comprising: surgically placing a spiral cuff around a portion of a blood vessel; locally altering blood flow characteristics within the blood vessel with an abutment formed within the cuff; Including, The spiral cuff is defined by an elastically deformable central spine coated with a compliant layer, the compliant layer having at least one abutment formation configured to abut against the vessel wall, the abutment formation providing: a reduction in the cross-sectional area of ​​the passageway extending through the blood vessel; and / or the vessel is deformed to define a curved region about one or more axes extending generally perpendicular to the direction of blood flow; A method is provided.

[0037] Preferably, a cable is positioned adjacent to the central spine, extending between the proximal and distal ends of the device, the length of the cable being selectively adjustable to vary the shape of the helix, such that shortening the cable decreases the pitch of the helix and increases the diameter of the helix.

[0038] The cross section of the central spine preferably varies along the length of the device between the proximal and distal ends.

[0039] The cross section of the spiral cuff preferably varies along the length of the device between the proximal and distal ends.

[0040] The device preferably further comprises one or more sensors disposed on the spiral cuff for obtaining data relating to blood flow characteristics within the blood vessel and / or blood vessel characteristics.

[0041] The sensor preferably includes one or more of an electrode, a pressure sensor, and an ultrasound emitter.

[0042] The sensor is preferably located on a radially inner portion of the spiral cuff and is positionable to directly abut the blood vessel.

[0043] The sensors are preferably configured to communicate wirelessly with a computer or other such device to transmit information regarding the measured blood flow and / or vascular characteristics.

[0044] The cross-sectional shape of the passageway preferably varies along the length of the device between the proximal and distal ends.

[0045] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0046] [Figure 1] 1 is a schematic diagram of the human heart. [Figure 2] 1 is a schematic diagram of a device for altering blood flow characteristics according to a first embodiment of the present invention; [Figure 3] FIG. 3 is a further schematic diagram of the apparatus of FIG. 2. [Figure 4] FIG. 1 shows a device for altering blood flow characteristics according to a second embodiment of the present invention. [Figure 5] FIG. 10 shows a device for altering blood flow characteristics according to a third embodiment of the present invention. [Figure 6] FIG. 10 shows a device for altering blood flow characteristics according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a side view of a device for altering blood flow characteristics according to a fifth embodiment when deployed. [Figure 8] FIG. 8 is a perspective view of the device of FIG. 7. [Figure 9] 8 is a further side view of the device for altering blood flow characteristics according to FIG. 7. [Figure 10] FIG. 8 is a cross-sectional side view of a portion of the device of FIG. 7. [Figure 11] FIG. 8 is a cross-sectional side view of a portion of the device of FIG. 7 when deployed. [Figure 12] FIG. 10 is a front view of the device according to the sixth embodiment. [Figure 13] FIG. 13 is a top view of the device of FIG. 12. [Figure 14] FIG. 14 is an end view of the device of FIGS. 12 and 13. [Figure 15] FIG. 15 is a partial detail of the end view of FIG. [Figure 16] FIG. 16 is a perspective view of the device of FIGS. 12 to 15. DETAILED DESCRIPTION OF THE INVENTION

[0047] Disclosed herein are several embodiments of devices 15, 50, 55, 60, 100, 200 for altering blood flow characteristics in the form of an external cuff or band 10 that is surgically placed around the outer wall of a blood vessel 20, preferably a carotid artery, including the common carotid artery or the internal carotid artery. The cuff 10 deforms the arterial wall, thereby altering the blood flow characteristics within the passageway 9 of the blood vessel 20 by changing the geometry of the blood vessel 20 such that the profile of the wall of the blood vessel 20 changes along the length of the cuff 10. The change in the structure of the blood vessel 20 results in a change in the cross-sectional shape and / or cross-sectional area and / or curvature or tortuosity of the vessel about an axis extending generally perpendicular to the direction of flow (i.e., the vessel becomes locally non-linear).

[0048] The devices 15, 50, 55, 60, 100, 200 are preferably placed around the circumference of the common carotid artery, and their intended function is to alter the dynamics of arterial blood pressure transmission to the cerebral microvasculature and absorb excess energy from the arterial pulsation.

[0049] Each embodiment of the device 15, 50, 55, 60, 100, 200 includes a member that is placed around a blood vessel during a surgical procedure.

[0050] In each embodiment described herein, the devices 15, 50, 55, 60, 100, 200 locally reduce the cross-sectional area or change the shape of the blood vessel 20 and / or deform the blood vessel 20 extending through a non-linear passage 25 that is curved or bent about one or more axes extending generally perpendicular to the direction of blood flow (i.e., the blood vessel becomes locally non-linear).

[0051] First embodiment In a first embodiment, shown in Figures 2 and 3, the device 15 includes a cuff 10 that constrains a portion of a blood vessel 20 to assume a bent or curved profile having curvature about one or more axes extending generally perpendicular to the direction of blood flow (i.e., the blood vessel 20 becomes locally non-linear). As shown, the cuff 10 includes an outer scaffold 30 fabricated from a suitable biocompatible material, such as stainless steel or nitinol. The scaffold 30 can be formed as two separate pieces, placed around the blood vessel, and attached to each other. Alternatively, the scaffold can be fabricated as a single piece that is sufficiently malleable so that it can be wrapped around the blood vessel before attaching the two opposing sides to define the generally tubular cuff 10.

[0052] An abutment formation in the form of a pad or cushioning 40 is disposed on the radially inner wall of the cuff 10. The pad 40 is preferably a gel pad 40 and may be defined by a single gel pad 40 or multiple individual gel pads 40. In the embodiment shown in Figures 2 and 3, the gel pad 40 causes deformation of the vessel 20, forcing it to locally assume a curved profile within the wall of the generally cylindrical scaffold 30. The curvature of the deformed vessel 20, as shown schematically in Figure 1, has a central concave region and adjacent convex regions, which causes the path of blood flow to deviate significantly from a straight line.

[0053] The pad 40 is not limited to a gel pad, but may be made from other materials such as polymers of various hardness or gas-filled cushions.

[0054] The gel pad 40 serves two purposes: First, the gel pad 40 induces a desired deformation in the wall of the blood vessel 20. Second, because the outer wall of the blood vessel 20 directly abuts the gel pad 40, the gel pad 40 attenuates the energy carried by the blood flow as it contacts the wall of the blood vessel 20.

[0055] The deformation of the blood vessel 20 forces the blood flow to take a non-linear path within the cuff 10. Thus, pressure waves traveling axially within the blood vessel 20 contact the walls of the blood vessel 20, which are then supported against the gel pad 40. The gel pad 40 absorbs a portion of the energy carried by the blood flow.

[0056] Additionally, deformation of the blood vessel 20 causes the reflected portion of the pressure wave to be non-axial with respect to the blood vessel 20. This typically causes the reflected wave to contact the wall of the blood vessel 20 at some other location, which also reduces the intensity of the energy carried by the pressure wave downstream of the cuff 10.

[0057] 2 and 3, the gel pad 40 and cuff 10 are configured to introduce a curvature into the blood vessel 20 while maintaining the generally circular cross-sectional area of ​​the blood vessel 20 so that the blood vessel 20 generally maintains its native diameter. In an alternative embodiment, in addition to introducing a curvature into the blood vessel 20, the cuff 10 can also alter the cross-sectional area or shape of the blood vessel 20. For example, the blood vessel is flattened partially along its length to assume an oval or elliptical cross-section having a cross-sectional area smaller than the native cross-sectional area of ​​the blood vessel 20. While the cross-section of the blood vessel 20 can be altered to any shape, typically the cross-section is flattened and stretched overall.

[0058] Such partial flattening of blood vessel 20 can desirably enhance the vessel's ability to bend due to the ribbon-like cross-sectional profile (when flattened) being more easily deformed.

[0059] The diameter (and length) of the passageway 25 through the tubular scaffold 30 relative to the natural outer diameter of the vessel 20 determines the amount of vessel curvature that can be introduced by a given cuff 10.

[0060] Second embodiment A second embodiment of the device 50 is shown in FIG. 4. In this embodiment, there are three gel pads 40 arranged around the cuff 10. Each gel pad 40 is approximately equally spaced longitudinally. Circumferentially, the gel pads 40 are offset approximately 120 degrees from each adjacent gel pad 40. The radial spacing of the gel pads 40 forces the blood flow to follow a more circuitous (non-linear) path. Furthermore, this arrangement provides several contact points that force axial pressure waves carried by the blood flow to contact the wall of the blood vessel 20 at locations supported by one of the gel pads 40.

[0061] Due to the presence of the three gel pads 40, when viewed axially through the blood vessel 20, there is a limited cross-sectional area within the blood vessel 20 that is not affected by any of the gel pads 40. In certain configurations, due to the level of deformation caused by the gel pads 40, there may not be a straight line through the blood vessel 20. However, because the gel pads 40 are spaced axially, each gel pad 40 only partially restricts or changes the shape of the local cross-sectional area of ​​the blood vessel 20. Therefore, because the local cross-sectional area of ​​the blood vessel 20 at any location does not significantly change relative to the original cross-sectional area of ​​the blood vessel 20, volumetric blood flow through the device 50 is not significantly affected. Thus, the device 50 can deflect and / or absorb a portion of the energy carried by pressure waves without significantly interfering with the volumetric blood flow velocity.

[0062] 4, the scaffold is defined by a tube placed around the blood vessel, which has a longitudinal split defining two arms 35. The arms 35 may be secured to one another by welding, suturing, gluing, stapling, corresponding male and female mating formations, or some other means that allows for quick attachment of the arms 35 to one another during surgery. It will be understood that in embodiments where the scaffold is made from a metallic material such as Nitinol, mating may not be necessary.

[0063] Third embodiment A third embodiment of the device 55 is shown in FIG. 5. The third embodiment is functionally similar to the second embodiment described above. However, there are three pairs of gel pads 40. A first pair of gel pads 42 are positioned diametrically opposite one another at a first (proximal) end 52 of the device 55. A second pair of gel pads 46 are positioned diametrically opposite one another generally at a second (distal) end 56 of the device 55.

[0064] The third pair of gel pads 44 is positioned adjacent to the first pair in the longitudinal central region 54 of the device 55. The third pair of gel pads 44 is circumferentially offset by approximately 90 degrees relative to the first and second pairs of gel pads 42, 46.

[0065] Each pair of gel pads 42, 44, 46 locally flattens the blood vessel 20 so that the blood vessel 20 locally assumes an oval or elliptical profile, or at least a non-circular profile. In this way, at the junction between each pair of gel pads 42, 44, 46, the pressure wave encounters a step-like change in the geometry of the blood vessel 20.

[0066] As with the second embodiment described above, when viewed axially through the blood vessel 20, there is a limited cross-sectional area within the blood vessel 20 that is at the radial center of the blood vessel 20 and is not affected by any of the gel pads 40.

[0067] Fourth embodiment A fourth embodiment of the device 60 is shown in Figure 6. The fourth embodiment is similar to the third embodiment described above, but omits the central pair of gel pads. Thus, in the fourth embodiment, there is a first pair of gel pads 62 located at a first end 64 of the device 60 and a second pair of gel pads 66 located at an opposing second end 68 of the device 60.

[0068] In the fourth embodiment, the space between the pair of gel pads 62, 66 defines an expansion chamber 70 in the central longitudinal region of the device 60. The expansion chamber 70 allows the blood vessel 20 to locally expand or distend, which results in a remodeling of the vessel's geometry and a reduction in pressure within the blood vessel 20. The expansion of the portion of the blood vessel 20 within the region of the expansion chamber 70 can occur permanently within the device 60 or as a result of changes in blood pressure within the vessel.

[0069] In a variation of the fourth embodiment not shown in the drawings, the gel pads 62, 66 may be circumferentially offset from one another by approximately 90 degrees, with an expansion chamber 70 therebetween.

[0070] Although the pads described in each embodiment are described as separately formed components, it will be understood that the pads may be integrally formed with the cuff 10.

[0071] Fifth embodiment A fifth embodiment of device 100 is shown in Figures 7-11. Device 100 generally includes a spiral or cuff 110, and in a manner similar to the previous embodiments, device 100 is intended to be placed externally around the outside of the common or internal carotid artery.

[0072] The device 100 has a helical profile and therefore can be positioned around the blood vessel 20 with minimal interference during a surgical procedure, and the resilience of the device 100 allows the blood vessel 20 to be radially seated within a central passage 25 that extends longitudinally through the helix of the device 100.

[0073] The device 100 includes a central spine 120 fabricated from an elastically deformable material, such as medical-grade Nitinol™, or another suitable metal, metal alloy, or polymer. The spine 120 is coated with a silicone cover 130 or another suitable polymer. The silicone 130 is conformable and reduces the risk of damage to the outer wall of the blood vessel 20. While the device is depicted with the silicone cover 130, it can alternatively be fabricated without the cover 130, such that the spine 120 defines an outer surface that abuts the blood vessel 20.

[0074] The device 100 is a single-piece device with no articulating parts and is constructed in the form of an open spiral helix with a total length preferably of about 45 mm, but may be provided in different lengths ranging from 20 to 55 mm for the common carotid artery, but may be longer or shorter for other vessels 20.

[0075] As shown in FIG. 7 , device 100 is designed to fit around the outside of the common or internal carotid artery and deflect the artery (smoothly and continuously) along the length of the arterial segment. For example, an 8 mm diameter common carotid artery will deflect approximately 6 degrees from its long axis each time it passes through device 100. Upon exiting device 100, artery 20 resumes its natural path. The inner diameter of the spiral of device 100, which defines central passage 25, is selected to be smaller than the local arterial outer diameter to properly deflect the artery. However, because device 100 deforms the artery only at the contact points, i.e., along the spiral, and does not completely surround the artery, it does not significantly change the cross-sectional area or shape of the artery. If the pitch is small enough, device 100 can reduce the diameter of the artery, thereby deflecting it and reducing its cross-sectional area. The pitch of device 100 can be constant or variable. If the helical pitch is fine enough, the device 100 can act like a continuous tube, with minimal or no spacing between adjacent helical peaks.

[0076] 10, the central helical spine 120 is fabricated from a piece of Nitinol™ plate that is wound such that the spine 120 is wound about a longitudinal helical axis. Thus, the spine 120 is elastically deformable, able to stretch and wrap around the vessel 20 and then spring back to the original diameter of the device 100. The helical spine 120 is preferably preformed into a self-supporting helix, fabricated, for example, by a heat-setting process.

[0077] 10, the cross-sectional shape of the silicone cover 130 is generally contoured to have an oval, elliptical, oval, or other such shape in outline, which allows the vessel 20 to deform gradually, reducing the risk of injury to the vessel 20. This also helps create a gradual transition within the vessel 20 from the region of its original diameter to the region deformed by the device 100.

[0078] 11, the radially outer surface of the silicone 130 is defined by a portion of a cylinder or tube such that the radially outer surface is locally parallel to the longitudinal axis of the device 100. In contrast, the radially inner surface of the silicone 130 is curved such that when cut through a plane parallel to and passing through the longitudinal axis of the spiral, the cross-sectional area of ​​the silicone 130 is generally "D" shaped.

[0079] The device 100 is intended to locally alter a blood vessel by changing its shape and / or diameter and / or flow direction. For example, the device 100 can reduce the vessel's original cross-sectional area by approximately 5% to 30%, preferably approximately 10% to 20%, and most preferably approximately 15%. However, the reduction in cross-sectional area may be greater, even up to 50%. To accommodate vessels of various cross-sectional areas, the device 100 is manufactured with various helical diameters, and the device 100 with the most appropriate dimensions is selected prior to the surgical procedure to achieve an optimal fit to the patient's vascular geometry and the intended cross-sectional area restriction. It is envisioned that the device 100 may be supplied in approximately 12 different sizes, with the preferred size being determined by imaging the blood vessel 20 preoperatively. Another means of reducing the passageway 25 within the device 100 is by modifying the silicone cover 130 within the device to a thicker or thinner version. Alternatively, the device may be shortened and its internal diameter increased by placing a cable at one end and pulling from the other end. For this purpose, the nitinol spine may be a hollow tube. As described in the sixth embodiment below, the cable can be shortened or lengthened by turning a screw at one end of the device.

[0080] In the embodiment shown in Figures 7-9, the length of device 100 is equal to a multiple of the pitch, approximately 1.5 times. It will be understood that the length of device 100 may be some other multiple of the pitch, such as approximately 1-2 times the pitch. In more extreme cases, the coil may be up to 30 times the pitch or more. Alternatively, device 100 may be provided with a fixed length, regardless of pitch.

[0081] 9, inwardly extending protrusions 140 may be formed on the inner wall of the silicone cover 130. The protrusions 140 assist in further localized deformation of the vessel 20. The protrusions 140 may be spaced intermittently along the length of the spiral, each directed radially inward.

[0082] It will be understood that the ratio of the cross-sectional areas of the Nitinol™ spine 120 to the silicone 130 may vary beyond the embodiment shown in the drawings. For example, providing the Nitinol™ with a thicker cross-sectional area may increase the stiffness of the device 100. It will be understood that the Nitinol may vary in cross-section along its length, for example, being stiffer at the ends and softer in the middle.

[0083] The fifth embodiment of the spiral device 100 operates in a manner similar to the previous embodiment of Figure 4. As shown in that figure, the pad 40 is configured in a manner functionally similar to the spiral of the fifth embodiment. Similarly, the silicone present on the inner surface of the spiral of the fifth embodiment provides cushioning against the outer wall of the blood vessel in a manner similar to the pad 40 of the first through fourth embodiments.

[0084] Sixth embodiment A sixth embodiment of device 200, which is a variation of the fifth embodiment 100, is shown in Figures 12-16. Device 200 generally includes a spiral or cuff 210, and in a manner similar to the previous embodiments, device 200 is intended to be placed externally around the outside of the common or internal carotid artery (or another suitable blood vessel).

[0085] The radially inner wall of the cuff 210 may be smooth or may be textured.

[0086] The device 200 has a helical profile and therefore can be positioned around the blood vessel 20 with minimal interference during a surgical procedure, and the resilience of the device 200 allows the blood vessel 20 to be radially seated within a central passage 25 extending longitudinally through the helix.

[0087] The device 200 includes a central spine 220 fabricated from an elastically deformable material, such as medical-grade Nitinol™, stainless steel, or another suitable metal, metal alloy, or polymer. The spine 220 is covered with a covering of silicone 230 or another biocompatible polymer. The silicone covering 230 is conformable, may contain and / or release drugs, and may reduce the risk of damage to the outer wall of the blood vessel 20.

[0088] 12, for example, a tension wire or cable 240 runs through the helix adjacent to the central spine 220. In a preferred embodiment, the tension wire 240 is secured to the central spine 220 at several spaced apart anchoring points 250. The anchoring points 250 can take a variety of forms, such as lugs 250 with eyelets for receiving the wire 240. Similarly, the tension wire 240 may run through the center of the hollow spine 220.

[0089] 14 and 15, cable 240 has an adjustment mechanism 260 disposed at one end of device 200. Adjustment mechanism 260 may be in the form of an interacting screw and nut, a worm drive, a hose clamp-type slotted screw, or some other mechanism configured to selectively mechanically shorten the length of cable 240. The cable is attached at each end to central spine 220 and intermittently to anchor points 250, so that shortening cable 240 decreases the length and increases the diameter of the helix. This has the effect of radially expanding device 200 around the vessel.

[0090] The radial expansion or contraction of the helix may be performed manually during placement, or alternatively, remotely or mechanically in a post-operative procedure, as described below. For example, cable 240 may be intermittently or occasionally adjusted, e.g., remotely or mechanically, in keyhole surgery. Such adjustments may be made to accommodate changes in the vessel, changes in the patient's blood flow characteristics, or for any other purpose.

[0091] Referring to FIG. 12, device 200 includes a radio component 280 and a copper coil winding 290 or other such antenna.

[0092] The wireless component may receive a signal that instructs, for example, the diameter of the helix to expand or contract.

[0093] 13, the device 200 also has a tab 300 that houses a sensor facing other associated components located on the spiral so that measurements can be taken on diametrically opposite sides of the spiral. One such component could be a mirror or reflector 320 for ultrasound purposes, or an LED receiver 330.

[0094] Various sensors or communication devices may be provided on the spine 220 or overlying silicone cover 230, such as platinum electrodes 340, pressure sensors 360, and ultrasound emitters 380.

[0095] In a preferred embodiment, the electrodes 340 and pressure sensor 360 extend radially inward through the surface of the silicone cover 230 so that the electrodes 340 and pressure sensor 360 can be placed in direct contact with the wall of the blood vessel 20.

[0096] Referring to FIG. 15, the central spine 220 can be fabricated by sandwiching a nitinol helix 400 .

[0097] The sensors and adjustment mechanisms of the device 200 may be controlled by a printed circuit board (PCB), such as the double-upflex PCB 410 shown in FIG.

[0098] In each of the embodiments described herein, the cuff 10 is typically about 40-50 mm in length, but may be longer or shorter.

[0099] When treated with each of the devices of the first to fourth embodiments, the diameter of the blood vessel 20 can be reduced by about 3% to 30%, preferably about 5% to 15%, and most preferably about 10% by each pad.

[0100] In the embodiments of Figures 2-6, varying the inner diameter of the device 15, 50, 55, 60 can be achieved by varying the dimensions of the silicone cover 130. In the embodiments of Figures 7-16, varying the inner diameter of the spiral can be achieved by varying the dimensions (particularly the thickness) of the silicone cover 120 or the dimensions of the spine 130. Additionally, varying the inner diameter can be achieved by mechanisms such as shortening the cable, for example, as described with respect to the sixth embodiment.

[0101] It will be appreciated that the cross-section of the silicone cover 130 can be constant between the proximal and distal ends. Alternatively, the cross-section of the silicone cover 130 can vary between the proximal and distal ends. Similarly, there can be variations in the cross-section of the central spine 220, which is preferably fabricated from Nitinol.

[0102] Advantageously, when placed around a blood vessel 20, such as the carotid artery, the cuff 10 does not significantly affect blood flow velocity, as autoregulation of blood flow helps maintain the natural volumetric blood flow rate.

[0103] Although the present invention has been described with reference to specific examples, those skilled in the art will appreciate that the present invention may be embodied in many other forms.

Claims

1. A device for altering blood flow characteristics in an artery supplying blood to the brain, comprising: a spiral cuff configured to be surgically placed around the exterior of a portion of an artery that supplies blood to the brain; a first abutment formation defined by an inner wall of the spiral cuff; a central spine disposed within the spiral cuff; Equipped with the abutment formation defines a non-linear path within the spiral cuff; the spiral cuff is defined by an elastically deformable spiral coated with a compliant layer; Device.

2. The abutment forming portion a locally reduced cross-sectional area of ​​the passageway extending through the spiral cuff; and / or a passageway extending through the spiral cuff having a varying cross-sectional shape; 10. The apparatus of claim 1.

3. 3. The device of claim 1 or claim 2, wherein the elastically deformable spiral is made from Nitinol™ and the compliant layer is made from silicone.

4. 4. The device of claim 1, wherein the radially inner surface of the compliant layer is curved such that when cut through a plane parallel to and passing through the longitudinal axis of the spiral, the cross-sectional area of ​​the compliant layer is generally "D" shaped.

5. The device of any one of claims 1 to 4, wherein the radially inner surface of the compliant layer has at least one inwardly extending protrusion.

6. 6. The device of claim 1, wherein a cable is disposed adjacent to the central spine, the cable extending between the proximal and distal ends of the device, the length of the cable being selectively adjustable to vary the shape of the helix, whereby shortening the cable decreases the pitch of the helix and increases the diameter of the helix.

7. The device of claim 1 , wherein the cross-sectional area of ​​the passageway varies along the length of the device between the proximal and distal ends.

8. The device of claim 1 , wherein the cross-sectional shape of the passageway varies along the length of the device between the proximal and distal ends.

9. The device of claim 1 , wherein the cross-section of the spiral cuff varies along the length of the device between the proximal and distal ends.

10. An apparatus as described in any one of claims 1 to 9, further comprising one or more sensors positioned on the spiral cuff to obtain data relating to blood flow characteristics in the arteries supplying blood to the brain and / or vascular characteristics of the arteries supplying blood to the brain.

11. The device of claim 10 , wherein the sensor includes one or more of an electrode, a pressure sensor, and an ultrasound emitter.

12. 12. The device of claim 10 or claim 11, wherein the sensor is located on a radially inner portion of the spiral cuff and is positionable to directly abut an artery that supplies blood to the brain.

13. 13. The apparatus of any one of claims 10 to 12, wherein the sensor is configured to communicate wirelessly with a computer or other such device to transmit information about the measured blood flow characteristics and / or vascular properties of the arteries supplying blood to the brain.

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