Patent Description:
Intraoperative embolic stroke is one of the most dreadful complications of cardiac, aortic and vascular procedures, diagnosed in <NUM>-<NUM>% of patients undergoing cardiovascular surgery. Even more frequently, in up to <NUM>% of cases, patients undergoing heart, valve, coronary artery bypass and aortic surgery experience subclinical embolic events as recorded by transcranial Doppler and MRI. These embolic events lead to cognitive impairment and disability and have a significant impact on patients' recovery.

The main sources of cerebral emboli and stroke in this setting resides in the heart, heart valves, thoracic aorta, and great vessels when these structures are intervened thereon. Even simple cardiac catheterization with an endovascular catheter can induce microtrauma of the atherosclerotic thoracic aorta leading to formation of embolic particles with subsequent embolic brain injury ranging from latent ischemic foci to a massive or even fatal stroke.

Multiple devices are known that attempt to prevent embolization of the carotid arteries during endovascular and cardiac interventions by using different types of filters, deflection devices or endoluminal balloons. These anti-embolic devices, however, have not received wide acceptance in surgery of the heart, heart valves and thoracic aorta due to their complexity and invasive character with the risk of additional trauma to the inner vessel wall resulting in a high risk to benefit ratio. Known devices require insertion of additional hardware into the arterial system or aorta, a procedure that is known by itself to be associated with all classical risks of endovascular intervention , including aortic dissection, bleeding, thrombosis, and carotid cerebral embolization and stroke. One known intra -aortic filter device that is inserted into the ascending portion of the thoracic aorta via an aortic cannula to capture potential embolic material released from the heart and aortic wall during heart surgery was found to be quite difficult to implement and was reported to be associated with major trauma to aortic wall and acute aortic dissection.

Aside from introducing hardware into the patient and causing the aforementioned problems, intravascular filters are not able to capture embolus smaller than the pore size of the available devices (currently <NUM>-<NUM>) resulting in cerebral microembolization. Furthermore, the placement of the filter by itself may produce cerebral emboli. For example, the mere passing of a guide wire into a carotid artery generates approximately <NUM>,<NUM> microemboli, with a significant percentage of small, less than <NUM>, particles that are not retained by standard filters. Therefore, in spite of multiple innovations in the field of anti-embolic devices, the problem of cerebral emboli and stroke during cardiovascular surgery is far from being resolved. As such, there remains room for variation and improvement within the art.

<CIT> discloses a hemostasis device and method for closing wounds by the application of pressure. The device includes one or more inflatable bladders which may be coupled to a portion of a patient's body in order to apply pressure to a wound site upon inflation.

<CIT> discloses an extracorporeal intelligent blocking instrument for carotid bloodstream that comprises a neck collar and a support mounted on a horizontal plate, a carotid compression piece mounted on the support, an automatic carotid pressure regulating device, as well as an oxyhemoglobin saturation monitoring probe. A pressure head of the carotid compression piece is an airbag; the automatic carotid pressure regulating device comprises a singlechip used for main control, an oxyhemoglobin saturation signal processing circuit, a pressure measurement regulator, a human-computer interaction operation key, a display, a memorizer and a power supply, wherein, the oxyhemoglobin saturation signal processing circuit is connected with the oxyhemoglobin saturation monitoring probe and the singlechip respectively; the pressure measurement regulator is connected with the singlechip and connected with the airbag of the carotid compression piece through a pipe fitting; the human-computer interaction operation key, the display and the memorizer are connected with the singlechip respectively; and the power supply is connected with the singlechip, the oxyhemoglobin saturation signal processing circuit and the pressure measurement regulator respectively. The instrument can block the carotid bloodstream and monitor, regulate and record the strength and the time of carotid pressurization in a real time.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements.

It is to be understood that the ranges mentioned herein include all ranges located within the prescribed range. As such, all ranges mentioned herein include all sub-ranges included in the mentioned ranges. For instance, a range from <NUM>-<NUM> also includes ranges from <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. Further, all limits mentioned herein include all other limits included in the mentioned limits. For instance, a limit of up to <NUM> also includes a limit of up to <NUM>, up to <NUM>, and up to <NUM>.

The present invention provides for an apparatus of preventing stroke by diverting emboli from cerebral circulation as defined in claim <NUM>.

A device <NUM> is placed around the neck of a patient that is non-invasive and can include a longitudinal carotid expandable member <NUM> and/or a transverse carotid expandable member <NUM>. The members <NUM> and <NUM> can be expanded from an unactuated state to an actuated state in which the members <NUM> and <NUM> create an area of compression <NUM> at the carotid arteries <NUM> to prevent blood flow therethrough into the cerebral circulation. Emboli <NUM>, <NUM> that are formed in the patient secondary to emboligenic intervention are diverted into a descending aorta <NUM> and other vascular structures.

With reference to <FIG>, a front view of a patient is shown in which emboli <NUM> are transferred from the aortic arch <NUM> into the carotid arteries <NUM>. The emboli <NUM> that are present in the carotid arteries <NUM> can then be transferred into the cerebral circulation causing stroke of the patient. The emboli <NUM> may be fragments of atherosclerotic plaque <NUM> of the aorta <NUM> that become dislodged during manipulation of the ascending thoracic aorta <NUM>. Also shown in <FIG> is calcification of the aortic valve <NUM> and intracardiac emboli <NUM> of the heart <NUM> that can also be the origin of emboli <NUM> eventually present in the carotid artery <NUM>. The intracardiac emboli <NUM> may include air, gas, thrombi and atherosclerotic materials. Although all of the various emboli in the heart <NUM>, aortic arch <NUM> and aortic valve <NUM> need not be present in all instances, they are all shown in <FIG> for sake of example. Trauma to the heart <NUM>, aortic valve <NUM> and aortic structures during placement and removal of items such as an aortic clamps, balloon valvuloplasty and electrophysiological instruments, along with manipulations such coronary artery bypass grafting, aortic and mitral valve replacement, catheter ablation, endovascular grafting of the aorta <NUM>, percutaneous implantation of the aortic or mitral valves, endovascular manipulations on the aorta <NUM>, aortic branches and the heart <NUM> may give rise to the presence of emboli <NUM> in the carotid arteries <NUM>. Critical moments of the aforementioned procedures (for example during the aortic cross clamp manipulation, aortic valvuloplasty or valve implantation, coronary interventions, and endovascular procedures on the aorta) may cause emboli <NUM> to form and cause stroke and are referred to as "emboligenic" events.

<FIG> and <FIG> show the disclosed method of diverging emboli <NUM> from cerebral circulation by exerting external compression to form areas of compression <NUM> at the carotid arteries <NUM> to lead to temporary interruption of carotid flow. The distal carotid arteries <NUM> are present downstream from the areas of compression <NUM>, and the proximal carotid arteries are the portions of carotid arteries <NUM> upstream from the areas of compression <NUM>. Upon creation of the areas of compression <NUM>, a relative pressure gradient and a "no-flow" condition is produced in the proximal carotid arteries <NUM> that prevents emboli <NUM> from entering the cerebral circulation. The proximal carotid arteries <NUM> are areas of the carotid arteries <NUM> upstream from the areas of compression <NUM> that have interrupted blood flow due to the compression. Potential carotid emboli <NUM> are diverted into the descending aorta <NUM> and are illustrated as emboli <NUM>. The arrow <NUM> shows preferential direction of the blood flow that carries potential cerebral emboli <NUM> into the descending aorta <NUM> when the areas of compression <NUM> are created.

<FIG> disclose an exemplary embodiment of a device <NUM> that can be used to create the areas of compression <NUM> previously described to deflect emboli <NUM> from the carotid arteries <NUM> to prevent emboli in the cerebral circulation. The device <NUM> can be positioned on the neck of the patient so that a pair of straps <NUM> and <NUM> extend around to the back of the neck of the patient and are secured to one another via hooks <NUM> and loops <NUM> that form a hook and loop type arrangement. However, it is to be understood that other mechanisms of securing the straps <NUM> and <NUM> to one another are possible and that the disclosed arrangement is only one exemplary embodiment. Securement of the hooks <NUM> and loops <NUM> causes the device <NUM> to be retained onto the neck of the patient. This retention may be loose so that the device <NUM> has some room to give on the neck, or the retention may be of a tightness that firmly secures the device <NUM> onto the neck and prevents same from moving or twisting. The device <NUM> may be a neck collar in accordance with various exemplary embodiments. In other arrangements the device <NUM> may be a strap that lays on the front of the neck of the patient, or may be made of multiple components that are not directly attached to one another but are positioned proximate to the neck of the patient. The device <NUM> may include two semi-oval halves that may be positioned around the neck of the patient in accordance with one exemplary embodiment. The device <NUM> need not be circular in shape. Even if the device <NUM> is not circular in shape it may still have a central axis <NUM> as the central axis <NUM> can be located at the center of the neck of the patient and thus may still be a central axis <NUM> of the device <NUM>.

With reference in particular to <FIG>, a pair of insertion pockets <NUM> and <NUM> are present on the device <NUM> and may be sealed at their tops and bottoms with respect to the vertical direction <NUM>. As used herein, the vertical direction <NUM> may be the direction of the device <NUM> that is parallel to the direction of extension of the central axis <NUM>. Strap <NUM> may extend from the first insertion pocket <NUM>, and strap <NUM> may extend from the second insertion pocket <NUM>. The first insertion pocket <NUM> forms a cavity into which a first longitudinal carotid expandable member <NUM> is located. Member <NUM> is shown in a deflated or unactuated state in <FIG> and may be made of a flexible material that can be stretched or otherwise deformed. The material making up member <NUM> can be nonporous such that member <NUM> is capable of being filled with gas or liquid that enables the member <NUM> to expand and at the same time hold the gas or liquid therein. The pocket <NUM> may be made of a material that is different than the material making up member <NUM>.

The second insertion pocket <NUM> forms a cavity into which the second longitudinal carotid expandable member <NUM> is retained. Member <NUM> may be configured in a manner similar to member <NUM> and a repeat of this information is not necessary. Member <NUM> may be completely sealed except for an opening that leads into connecting tube <NUM>. Member <NUM> is in an unactuated state in <FIG>.

A pressure source <NUM> is included and is placed into fluid communication with the first longitudinal carotid expandable member <NUM> by way of pressure tubing <NUM> that extends through a port of member <NUM>. A manometer <NUM> may be included in the device <NUM> at some point between the member <NUM> and the pressure source <NUM> in order to monitor and measure pressure in the system. <FIG> illustrate the device <NUM> once the pressure source <NUM> is activated in order to cause the device <NUM> to be pressurized. The pressure source <NUM> may be a pump that injects air, gas or liquid, such as water, through the pressure tubing <NUM>. Injection of air or otherwise increasing the pressure causes the first longitudinal carotid expandable member <NUM> to expand. Due to fluid communication through the connecting tube <NUM>, the second longitudinal carotid expandable member <NUM> will likewise expand and the two members <NUM> and <NUM> may expand at the same rate to the same size. Expansion may be in the radial direction <NUM> such that the expandable members <NUM> and <NUM> expand towards the central axis <NUM> and away from the central axis <NUM>. In some exemplary embodiments, the members <NUM> and <NUM> may expand in the radial direction <NUM> towards the central axis <NUM> but not in the radial direction <NUM> away from the central axis <NUM>. This arrangement may be accomplished by making portions of the expandable members <NUM> and <NUM>, for example the portions facing away from the central axis <NUM> in the radial direction <NUM>, such that they cannot expand while the portion facing towards the central axis <NUM> are in fact expandable. The expandable members <NUM> and <NUM> may be inflated to a pressure level that is above the level of the patient's arterial pressure to achieve temporary interruption of the carotid blood flow. Both the left and right carotid arteries <NUM> can be compressed at the same time.

Additionally or alternatively, the insertion pockets <NUM> and <NUM> could have portions that are made of different materials so that the parts facing the central axis <NUM> in the radial direction <NUM> are expandable while the parts facing away from the central axis <NUM> in the radial direction <NUM> are not expandable. The expandable members <NUM> and <NUM> are elongated in the vertical direction <NUM>, which is the same direction as the central axis <NUM>. However, it may be the case that upon expansion of the expandable members <NUM> and <NUM> from the unactuated to the actuated states the expandable members <NUM> and <NUM> do not expand in the vertical direction <NUM>.

The exemplary embodiment of the device <NUM> in <FIG> does not include a transverse carotid expandable member <NUM> but instead includes only two expandable members <NUM>. The device <NUM> may be placed onto the patient so that the first longitudinal carotid expandable member <NUM> overlays the carotid artery <NUM> such that the carotid artery <NUM> is located between the central axis <NUM> and the member <NUM> in the radial direction <NUM>. The second longitudinal carotid expandable member <NUM> may be laid on top of the other carotid artery <NUM> such that the second carotid artery <NUM> is likewise between the member <NUM> and the central axis <NUM> in the radial direction <NUM>. Expansion forces of the expandable members <NUM> and <NUM> may be imparted onto the carotid arteries <NUM> so that they are compressed thus forming the areas of compression <NUM> as previously discussed. The pressure in the expandable members <NUM> and <NUM> may be set so as to exceed the patient's systemic pressure to achieve adequate compression of the carotid arteries <NUM> to have a transient "no-flow" effect. In some arrangements the pressure of the members <NUM>, <NUM> and/or <NUM> may exceed the patient's systemic pressure by <NUM>-<NUM> Hg, or up to <NUM> Hg or higher in accordance with certain exemplary embodiments. Once the "emboligenic" part of the procedure is completed, the pressure in members <NUM> and <NUM> may be released in order to establish carotid arterial flow.

Another exemplary embodiment of the device <NUM> is illustrated in <FIG>. The device <NUM> in this exemplary embodiment also functions to compress the carotid arteries <NUM> to create the areas of compression <NUM>. The device <NUM> includes a first insertion pocket <NUM> and a second insertion pocket <NUM> but lacks first and second longitudinal carotid expandable members <NUM> and <NUM>. Instead a first compression member <NUM> is located within the first insertion pocket <NUM>, and a second compression member <NUM> is located within the second insertion pocket <NUM>. The compression members <NUM> and <NUM> are not expandable but may be made of a material, such as foam, that can be compressed and then can subsequently expand back into its original shape. The compression members <NUM> and <NUM> may alternatively be made of a material that does not exhibit any give upon the application of forces thereto that would be encountered in a procedure of the type described herein. The compression members <NUM> and <NUM> may be elongated in the vertical direction <NUM> and may have a convex shape that faces the central axis <NUM>. The shape of the compression members <NUM> and <NUM> at their surfaces that face away from the central axis <NUM> in the radial direction <NUM> may be different than those that face towards the central axis <NUM>.

The device <NUM> may include a transverse carotid compression section <NUM> that is located outward from the compression members <NUM> and <NUM> in the radial direction <NUM> from the central axis <NUM>. A transverse carotid expandable member <NUM> may be held by the section <NUM> and can have an arc length about the central axis <NUM> that extends beyond both of the compression members <NUM> and <NUM>. The transverse carotid expandable member <NUM> has a height in the vertical direction <NUM> that is the same as, larger or smaller than the height of the compression members <NUM> and <NUM> in the vertical direction <NUM>. The member <NUM> is made of a material that will hold air, gas or liquid such that it can be expanded upon the application of fluid thereto. The member <NUM> has a single port that is in fluid communication with the pressure tubing <NUM>. Application of pressure to the member <NUM> will cause the member <NUM> to expand as shown for example in <FIG>. In other embodiments, the compression members <NUM> and <NUM> can be removed and not present so that only the expandable member <NUM> is present to compress the carotid arteries <NUM>.

The transverse carotid compression section <NUM> can be arranged so that all of it is expandable or so that only a portion of it expands as the member <NUM> expands. Boundary lines <NUM> and <NUM> may demarcate areas of the transverse carotid compression section <NUM> that can expand from those that cannot expand. For example, the portion of section <NUM> radially outward from the boundary lines <NUM> and <NUM> may not be capable of expansion while the portions of section <NUM> radially inward from boundary lines <NUM> and <NUM> are capable of stretching and thus expanding or contracting. This arrangement may cause expansion only, or primarily, in the radially inward direction upon expansion of the expandable member <NUM>. In other embodiments, the section <NUM> is made of the same material and exhibits expansibility such that it generally expands in all directions equally. The expandable member <NUM> may be arranged so that it does not lengthen in the vertical direction <NUM> upon expansion, or in some arrangements only minimally expands in the vertical direction <NUM> when actuated.

Placement of the device <NUM> onto the patient may result in the first compression member <NUM> overlaying the carotid artery <NUM> so that the carotid artery <NUM> is between compression member <NUM> and the central axis <NUM> in the radial direction <NUM>. The second compression member <NUM> will be arranged so that it overlays the second carotid artery <NUM> causing it to be between the second compression member <NUM> and the central axis <NUM> in the radial direction <NUM>. The expandable members <NUM>, <NUM> and <NUM> may be located at the neck of the patient such that they are secured to the neck or otherwise proximate the neck. The expandable members <NUM>, <NUM> and <NUM> need not be in direct contact with the neck of the patient but only located near the neck of the patient. Application of pressure via the pressure source <NUM> causes the transverse carotid expandable member <NUM> to expand in the radial direction <NUM>. This inward radial expansion causes the compression members <NUM> and <NUM> to move inwards and be urged against the carotid arteries <NUM>. The positioning and configuration of the members <NUM> and <NUM> function to impart compressive forces onto the carotid arteries <NUM> when the device <NUM> is pressurized thus resulting in the creation of the areas of compression <NUM>. The other components of the device <NUM> may be made as those previously described and a repeat of this information is not necessary.

Although described as lacking first and second longitudinal carotid expandable members <NUM> and <NUM>, an alternative arrangement may be made in which these members <NUM> and <NUM> are present. In such an arrangement, the expandable members <NUM> and <NUM> may expand in order to press the compression members <NUM> and <NUM> towards the carotid arteries <NUM>.

An alternative exemplary embodiment of the device <NUM> is illustrated with reference to <FIG> in which both a pair of longitudinal carotid expandable members <NUM> and <NUM> are present along with a transverse carotid expandable member <NUM>. A pair of compression members <NUM> and <NUM> may be missing from this embodiment, or they may be present in certain arrangements. This exemplary embodiment includes additional pressure tube lines <NUM> and <NUM> that are separate from pressure tubing <NUM> that actuates the transverse carotid expandable member <NUM>. Pressure tube lines <NUM> and <NUM> provide pressure to the first and second longitudinal carotid expandable members <NUM> and <NUM> so that these members <NUM> and <NUM> can be expanded at different rates, amounts, and/or times than expandable member <NUM>. This flexibility provides selective pressure adjustments between the transverse carotid expandable member <NUM> and the pair of longitudinal carotid expandable members <NUM> and <NUM>. This feature will provide an option to decrease or completely eliminate the degree of circumferential neck compression when selective inflation of the two longitudinal carotid expandable members <NUM> and <NUM> is adequate. Conversely, if inflation of members <NUM> and <NUM> does not lead to sufficient reduction of the carotid flow, an additional inflation of the expandable member <NUM> would allow one to achieve the desired effect by combining the effect of pressure created in all of the members <NUM>, <NUM> and <NUM>.

The preferred method of carotid artery <NUM> compression in this case will be an initial inflation of members <NUM> and <NUM>, followed by inflation of member <NUM> when necessary. The degree of interruption of the carotid flow in this and other embodiments can be checked by the data of carotid Doppler, trans-cranial Doppler, pulsation of the temporal arteries and other techniques of assessment of the carotid and cerebral perfusion. The other components of the device <NUM> are the same as those previously disclosed with respect to other embodiments and a repeat of this information is not necessary.

An alternative exemplary embodiment of the device <NUM> is disclosed with reference to <FIG>. The embodiment disclosed is similar to that previously disclosed with respect to <FIG> and a repeat of the features and functionality that are similar between the two need not be repeated. The pressurization of the members <NUM>, <NUM> and <NUM> are different in that the second pressure tube <NUM> feeds into the first longitudinal carotid expandable member <NUM>, and in that the third pressure tube <NUM> supplies the second longitudinal carotid expandable member <NUM> to allow the members <NUM> and <NUM> to be pressurized independently from one another. In this regard, one can apply more or less pressure to member <NUM> than member <NUM> so that compression of the carotid arteries <NUM> can be more precisely controlled. The transverse carotid expandable member <NUM> is supplied by pressure tubing <NUM> and is independent from the expansion of members <NUM> and <NUM> such that it can be pressurized to a greater or lesser extent than members <NUM> and <NUM>. The manometer <NUM> may be capable of measuring pressures in all of the lines <NUM>, <NUM> and <NUM> so that their individual pressures can be monitored. In use, one may adjust the pressures in members <NUM> and <NUM> first, then subsequently if needed one may apply pressure into member <NUM> to cause its expansion so that adequate compression of the carotid arteries <NUM> is realized.

The ports for the pressure lines <NUM> and <NUM> may be located at the bottom of the expandable members <NUM> and <NUM> in the vertical direction <NUM>. However, the ports for pressure lines <NUM> and <NUM> need not be in the disclosed locations in accordance with other exemplary embodiments and may be above the transverse carotid compression section <NUM> or at the same location as the section <NUM> in the vertical direction <NUM> in other exemplary embodiments. The insertion pockets <NUM> and <NUM> although described as being sealed may have an opening into which the expandable members <NUM> and <NUM> may be removed and into which first and/or second compression members <NUM> and <NUM> may be inserted so that the device <NUM> can function with the compression members <NUM> and <NUM> and transverse carotid expandable member <NUM> as previously discussed.

The arrangement of the device <NUM> in <FIG> thus includes a pair of longitudinal carotid expandable members <NUM> and <NUM> along with a transverse carotid expandable member <NUM>. With reference to <FIG>, the boundary lines <NUM> and <NUM> may be located at the boundaries of the straps <NUM> and <NUM> and the transverse carotid compression section <NUM>. The lengths of the members <NUM> and <NUM> in the vertical direction <NUM> are each longer than the length of the member <NUM> in the vertical direction <NUM>, and the arc length of the member <NUM> is larger than the arc lengths of the members <NUM> and <NUM> combined. The transverse carotid expandable member <NUM> may have an arc length that extends up to <NUM>% of the circumferential distance about the central axis <NUM>. In this regard, the member <NUM> may have an arc length that is up to <NUM> degrees about central axis <NUM>. The circumferential distance about the central axis <NUM> may also be the circumferential distance about the neck of the patient when the device <NUM> is worn by a patient and thus these two terms can be interchangeable when discussing the arc length of the member <NUM>. In other exemplary embodiments, the arc length of the member <NUM> may be from <NUM>-<NUM>% (<NUM> degrees - <NUM> degrees) about the circumference of the neck of the patient, from <NUM>%-<NUM>% (<NUM> degrees - <NUM> degrees) about the circumference of the neck of the patient, or from <NUM>%-<NUM>% (<NUM> degrees - <NUM> degrees) about the circumference of the neck of the patient. In yet other exemplary embodiments, the member <NUM> may extend <NUM> degrees completely about the central axis <NUM>/neck of the patient.

The members <NUM> and <NUM> are closer to the central axis <NUM> in the radial direction <NUM> than the member <NUM> is to the central axis <NUM>. Comparison of <FIG> and <FIG> demonstrate that the lengths of the members <NUM>, <NUM> and <NUM> do not increase in the vertical direction <NUM>, or in the arc length direction, upon moving from the unactuated orientation to the actuated orientation or only slightly expand in these directions upon actuation. The majority of the expansion may be in the radial direction <NUM> either towards the central axis <NUM> or away from the central axis <NUM> or a combination of the two. In other arrangements, however, expansion of the members <NUM>, <NUM> and <NUM> may result in equal expansion in all directions. As previously stated, various components of the device <NUM> in <FIG> may be arranged and function in a manner similar to those as previously discussed and a repeat of this information is not necessary.

<FIG> disclose modifications of the geometry of the members <NUM> and <NUM> with respect to the geometry of the transverse carotid expandable member <NUM> which is the same in both <FIG>. The different geometries for members <NUM> and <NUM> may be due to variations of neck anatomy in each patient. In patients with a short and large neck the embodiment in <FIG> may be employed that has longitudinal carotid expandable members <NUM> and <NUM> that are bigger and more round to achieve more efficient carotid compression. The length of each one of the members <NUM> and <NUM> in the vertical direction <NUM> may be less than the length of the member <NUM> in the vertical direction <NUM> both when all of the members <NUM>, <NUM> and <NUM> are unexpanded, and when all of the members <NUM>, <NUM> and <NUM> are expanded. In patients with a long and thin neck the preferred embodiment comprises the members <NUM> and <NUM>, as shown in <FIG>, that are more oval and narrow for the same reason of more efficient carotid compression to account for the differences in neck geometries of patients. The lengths of each of the members <NUM> and <NUM> in the vertical direction <NUM> is longer than the length of the member <NUM> in the vertical direction <NUM> both when all of the components <NUM>, <NUM> and <NUM> are unactuated and when they are all actuated.

<FIG> and <FIG> demonstrate the method of use and the effect of inflation of the device <NUM> resulting in external compression of both carotid arteries <NUM>, leading to transient interruption of carotid flow. These two figures demonstrate the anatomic relationship of the device <NUM> to both carotid arteries <NUM> and surrounding structures <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. The carotid arteries <NUM> are bordered by neck muscles <NUM>, esophagus <NUM>, trachea <NUM> and fat tissues <NUM>. These structures provide a protective cushion, minimizing the risk of carotid injury during external compression. In fact, an external compression of carotid arteries <NUM> in this setting would lead to significantly lower risk of injury to carotid intima than intravascular carotid occlusion with the balloon or umbrella devices used for cerebral protection in patients undergoing carotid stenting. The longitudinal carotid expandable members <NUM>, <NUM> are positioned along the course of both carotid arteries <NUM> on the neck.

The exemplary embodiment of the device <NUM> may be any one of those previously disclosed that lacks a transverse carotid expandable member <NUM>. However, it is to be understood that this is just one example and that other devices <NUM> that include member <NUM> can function in a similar manner to the device <NUM> disclosed in <FIG> and <FIG>. As shown in <FIG>, one of the longitudinal carotid expandable members <NUM> is placed along the course of one of the carotid arteries <NUM>, and the other expandable member <NUM> is placed along the course of the other carotid artery <NUM>. The lumen of both carotid arteries is compressed between the inflated bladders <NUM> and <NUM> anteriorly (outward in the radial direction <NUM>) and the cervical spine <NUM> posteriorly (inward in the radial direction <NUM>). Actuation of the members <NUM> and <NUM> cause the members to move radially inward and compress fat tissue <NUM> that is immediately adjacent the device <NUM>. The expandable members <NUM> and <NUM> are shown moving in the radial direction <NUM> inward of portions of the trachea <NUM> and neck muscles <NUM> so that portions of the expandable members <NUM> and <NUM> are closer to the central axis <NUM> in the radial direction <NUM> than portions of the trachea <NUM> and neck muscles <NUM>. Full expansion of the expandable members <NUM> and <NUM> may result in inward radial movement so that they are not radially closer to the axis <NUM> than any portion of the esophagus <NUM>. However, other embodiments are possible in which at least some portion of the expandable members <NUM> and <NUM> are closer to the central axis <NUM> than a portion of the esophagus <NUM>.

The soft tissues such as the fat tissues <NUM>, neck muscles <NUM>, esophagus <NUM> and trachea <NUM> around carotid arteries <NUM> provide a smooth cushion assuring adequate protection against carotid trauma. Expansion of the members <NUM> and <NUM> causes the areas of compression <NUM> to restrict blood flow through the carotid arteries <NUM> which leads to transient interruption of carotid flow. The trachea <NUM> and esophagus <NUM> are not closed or restricted upon actuation of the expandable members <NUM> and <NUM> due to the placement and specific configuration of the expandable members <NUM> and <NUM>. However, in some arrangements some degree of restriction of the trachea <NUM> and/or esophagus <NUM> may occur when the expandable members <NUM> and <NUM> are expanded. It may be advisable, however, to obtain carotid Duplex scan in all patients planned for this procedure to rule out significant atherosclerotic disease of these vessels <NUM>. If the patient is found to have severe carotid disease, the risk of dislodging the carotid plaque due to carotid compression should be weighed against the risk of stroke associated with the main cardiovascular intervention.

The divergence of potential cerebral emboli <NUM>, <NUM> and prevention of stroke can be achieved by a noninvasive safe method that involves external compression of the carotid arteries <NUM>. The method and device <NUM> disclosed do not require puncture of the skin or arteries and do not necessitate the use of endovascular devices. The device <NUM> and disclosed method allow for the divergence of emboli <NUM> and <NUM> of all sizes, including those microscopic particles that are too small to be trapped with the known intravascular filters.

Various types of mechanisms capable of compressing the carotid arteries <NUM> can be included in the device <NUM> in addition to or alternatively to those previously discussed. For example, the device <NUM> can be supplied with different carotid compression mechanisms, including different forms of longitudinal bladders, cuffs, compression pads or inserts with the same effect of carotid compression to the point of transient interruption of carotid flow. The fluid provided to pressurize the expandable components of the device <NUM> from the pressure source <NUM> may be a liquid substance in some embodiments. Fluid that is a liquid may be used in the device <NUM> to effect pressurization and more uniform constriction of the carotid arteries <NUM> than gas or air fluid because liquid is more non-compressible at the operating range of pressures. Liquid fluid in the members <NUM>, <NUM> and <NUM> may more directly transmit pressure to the carotid area than gas or air fluid.

Further, although shown as employing a single pressure source <NUM>, it is to be understood that multiple pressure sources <NUM> may be used. For instance, the transverse carotid expandable member <NUM> may be pressurized by a first pressure source <NUM> such as a pump, while a second source of pressure <NUM> is included in the device <NUM> to provide pressure to the two longitudinal carotid expandable members <NUM> and <NUM>.

A monitoring system <NUM> may be included with the device <NUM> to assure a safe, adequate, easily manageable and controllable compression of carotid vessels <NUM>. The monitoring system <NUM> may comprise Doppler ultrasound, Doppler probe, oscillotonometry, electroencephalography, transcranial Doppler, cerebral oximetry and/or other techniques. The device <NUM> may be actuated to such a degree that the two areas of compression <NUM> formed completely stop the flow of blood into the distal carotid artery <NUM>, or to an extent that partial flow of blood passes through the areas of compression <NUM> and into the distal carotid artery <NUM> and cerebral circulation.

The device <NUM> provided is a noninvasive and precise apparatus with an option of assessing a degree and an effectiveness of an interruption of the carotid flow by the optional inclusion of a monitoring system <NUM>. The device <NUM> assures a uniform and reproducible interruption of the carotid flow bilaterally minimizing the risk of trauma to the carotid artery wall and subsequent cerebral emboli <NUM>. According to an embodiment of the invention, alarm system <NUM> is included in the device <NUM> that is triggered by excessive or lengthy compression of the carotid arteries <NUM>. The alarm system <NUM> may be a part of the monitoring system <NUM> or may be a different component that is not part of the monitoring system <NUM>. The alarm system <NUM> thus measures.

the time of compression, and the magnitude of compression. Constant monitoring of carotid <NUM>, systemic arterial and device <NUM> pressures with pressure in the device <NUM> exceeding only slightly the pressure in the arterial system may be conducted to ensure safe operation and use of the disclosed device <NUM>. The device <NUM> provides a noninvasive compression apparatus that does not require the insertion of intravascular devices.

With reference now to <FIG>, an alternative exemplary embodiment of the device <NUM> is illustrated. Here, the device <NUM> lacks an expandable member <NUM>, <NUM>, or <NUM> and includes a compression member <NUM>. The particular arrangement of <FIG> also includes a second compression member <NUM>. The compression members <NUM>, <NUM> are located within and held by first and second insertion pockets <NUM> and <NUM>. The compression members <NUM> and <NUM> may be as previously described and a repeat of this information is not necessary. The compression members <NUM>, <NUM> may be referred to as compression members because they function to compress the carotid arteries <NUM>. The compression members <NUM>, <NUM> may themselves be compressible such that they can be deformed when force is applied thereto to be compressed and hence smaller. When the force is removed the compression members <NUM>, <NUM> can spring back to their non-compressed state. However, in some arrangements the compression members <NUM>, <NUM> are not compressible themselves at all and maintain the same size and shape when force is applied. The compression members <NUM>, <NUM> still function to compress the carotid arteries <NUM> even when they themselves are not compressible. The compression members <NUM>, <NUM> function without being expanded by the pressure source <NUM>. The device <NUM> of <FIG> lacks a pressure source <NUM> and no components of the device <NUM> are expandable.

A strap <NUM> extends from the boundary line <NUM> and has hooks <NUM> disposed thereon. Strap <NUM> extends from boundary line <NUM> and has loops <NUM> located on one surface thereof. The straps <NUM>, <NUM> extend circumferentially around the central axis <NUM> and may surround the central axis <NUM> up to <NUM> degrees in some exemplary embodiments. The straps <NUM>, <NUM> are adjustable in that they can be unattached from one another and then reengaged such that the points of contact between the hooks <NUM> and the loops <NUM> are changed. This change causes the relative size of the device <NUM> in the radial direction <NUM> to either increase to relive pressure on the neck of the patient, or decrease to increase the amount of pressure on the neck of the patient so that the compression members <NUM> and <NUM> apply greater pressure to the carotid arteries <NUM>.

Although shown and described as a pair of straps <NUM>, <NUM> it is to be understood that as used herein the term "strap" is broad enough to include a pair of straps, a single strap, or any other tightening mechanism. If a single strap is present it will extend from boundary line <NUM> to boundary line <NUM> and can be adjustable to increase pressure supplied by the device <NUM> to the neck of the patient, or non-adjustable such that it may function to hold the device <NUM> to the neck of the patient while some other mechanism functions to apply pressure to the compression members <NUM> and <NUM>.

Another exemplary embodiment of the device <NUM> is shown in <FIG>. The device <NUM> includes a pair of compression members <NUM>, <NUM> that are held by pockets <NUM> and <NUM>. The compression members <NUM>, <NUM> may apply pressure to the carotid arteries <NUM> and in this regard need to directly contact the skin of the neck of the patient. Instead, the insertion pockets <NUM> and <NUM> directly contact the skin of the neck of the patient, and the compression members <NUM>, <NUM> apply pressure to the carotid arteries <NUM> by exerting force through the insertion pockets <NUM>, <NUM> and into the neck of the patient. The embodiment in <FIG> lacks a source of pressure and the device <NUM> does not have an expandable member.

Strap <NUM> extends from boundary line <NUM> of the device <NUM> and is longer than strap <NUM> that extends from boundary line <NUM>. A lock and adjustment clip <NUM> is attached to the end of strap <NUM> and this attachment may be a permanent attachment. Strap <NUM> is not attached to the lock and adjustment clip <NUM> in <FIG>. The health care provider may place the device <NUM> around the neck of the patient so that the compression members <NUM>, <NUM> overlay the carotid arteries <NUM> of the patient. The strap <NUM> could be moved through the lock and adjustment clip <NUM> and secured thereto so that the strap <NUM> is attached to the strap <NUM> to cause the device to be held onto the neck of the patient. However, the tightening of the strap <NUM> relative to strap <NUM> may be loose such that the compression members <NUM>, <NUM> do not apply pressure to the carotid arteries <NUM>.

When compression of the carotid arteries <NUM> is desired, the health care provider may adjust the strap <NUM> relative to the lock and adjustment clip <NUM> as shown for instance in <FIG>. The health care provider can move a desired amount of the length of strap <NUM> through the lock and adjustment clip <NUM> and then lock the strap <NUM> to the lock and adjustment clip <NUM> so that it does not move relative thereto. This adjustment causes the size of the device <NUM> in the radial direction <NUM> to decrease, relative to the size in <FIG>, and forces the compression members <NUM>, <NUM> against the carotid arteries <NUM> to compress the carotid arteries <NUM>. The straps <NUM>, <NUM> thus function to not only hold the device <NUM> onto the neck of the patient, but to also apply the pressure necessary for compressing the carotid arteries <NUM>.

Other arrangements of the device <NUM> are possible. For example, the straps <NUM> and <NUM> can be located on the device <NUM> to hold the device <NUM> onto the patient but not to provide force that causes the compression members <NUM>, <NUM> to be pressed against the carotid arteries <NUM>. The device <NUM> may lack any members that are expandable, and thus may lack a pressure source <NUM>. A belt or other mechanism can be wrapped around the compression members <NUM>, <NUM> and may be tightened so that force from this tightening is transferred to the compression members <NUM>, <NUM> so that they in turn will be urged against the carotid arteries <NUM> to close the carotid arteries <NUM>.

A method for reducing or totally preventing cerebral emboli will now be discussed. A brief compression of carotid arteries <NUM> by way of a device <NUM> may be performed first to assure adequate position of the device leading to reduction or interruption of carotid flow or pulse as assessed by carotid Doppler, a pressure gauge, percutaneous cerebral oximetry or transcranial Doppler.

Once an adequate position of the device <NUM> is confirmed, the pressure in the carotid compression components (<NUM>, <NUM> and <NUM>) is released and the apparatus <NUM> is ready for use. The device <NUM> is inflated to the pressure exceeding patient's systemic pressure just before proceeding with the emboligenic part of the procedure. Adequate compression of carotid arteries <NUM> will lead to physiological reduction of flow through vertebral arteries leading to further divergence of blood and emboli away from all cerebral vessels and toward more distal arteries, thus decreasing the risk of stroke.

The pressure in the device <NUM>, and thus to the expandable components <NUM>, <NUM> and <NUM> is released after the emboligenic procedure is completed after a full washout of potential emboli <NUM>, <NUM> from the heart <NUM> and thoracic aorta <NUM>. The pressurization of the device <NUM> can be repeated any time and on multiple occasions when the emboligenic intervention is contemplated.

According to an embodiment of the invention, should the physician or physician's assistant forget to release carotid compression timely, an alarm would go off and the pressure would be released spontaneously to avoid undue interruption of the cerebral flow. The alarm and deflation can be overridden by the physician when clinically indicated. The alarm may be sounded by the alarm system <NUM>, and the deflation is activated by the pressure source <NUM> and/or the alarm system <NUM> According to an example not forming part of the invention, the deflation can be activated by the monitoring system <NUM>.

The central axis <NUM> may be present even when the device <NUM> is not configured with straps <NUM>, <NUM> to form a generally circular member when viewed from the top as for example in <FIG>. In some embodiments of the device <NUM>, a circular member is not formed when viewed from the top by the straps <NUM>, <NUM>. For instance, the straps <NUM>, <NUM> may be missing such that the section <NUM> is attached to sides of a bed or otherwise secured so that the device <NUM> is located at the neck of the patient. In such instances, the central axis <NUM> is still present. The central axis <NUM> may be located at a location within the neck of the patient, for examples shown with reference to <FIG> and <FIG>. This location may be at the spinal column <NUM> of the patient, or may be at the center of the neck of the patient. It is to be understood that various embodiments of the device <NUM> exist in which the device <NUM> does not wrap completely around the neck of the patient but instead only wraps around a portion of the neck of the patient less than <NUM> degrees fully about the neck of the patient.

Claim 1:
A device (<NUM>) for diverting emboli (<NUM>, <NUM>, <NUM>) from cerebral circulation of a patient, comprising:
a member (<NUM>, <NUM>, <NUM>) that is configured to press on a carotid artery (<NUM>) of the patient to compress the carotid artery (<NUM>) and limit blood flow through the carotid artery (<NUM>), wherein the member (<NUM>, <NUM>, <NUM>) is configured to be placed around the neck of the patient, wherein the member is an expandable member (<NUM>, <NUM>, <NUM>) that is configured to expand from a non-expanded configuration to an expanded configuration, wherein when the expandable member (<NUM>, <NUM>, <NUM>) is located at a neck of a patient and when in the expanded configuration the expandable member creates an area of compression (<NUM>) of the carotid artery (<NUM>) of the patient and restricts blood flow through the carotid artery (<NUM>), and wherein the device further comprises a pressure source (<NUM>) that is configured to apply pressure to the expandable member (<NUM>, <NUM>, <NUM>) to move the expandable member from the non-expanded configuration to the expanded configuration and a manometer (<NUM>) that is configured to measure the pressure applied by the pressure source (<NUM>);
characterised in that the device further comprises an alarm system (<NUM>) that is configured to measure a time of compression and a magnitude of compression of the expandable member, wherein if compression is applied for longer than a pre-determined time the alarm system (<NUM>) activates an alarm and spontaneously pressure in the expandable member is released by the pressure source and/or the alarm system, and wherein the alarm and the release of pressure can be manually overridden.