Patent Publication Number: US-11020211-B2

Title: Accessory device to provide neuroprotection during interventional procedures

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/366,696 filed Mar. 27, 2019 which is a non-provisional of U.S. provisional No. 62/648,393 filed Mar. 27, 2018, the content of both of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     Devices, systems and methods for filtering embolic particles that may be generated from a medical procedure including protection of the major branching vessels from the aorta and catches and filters emboli that may be generated during the TAVR procedure. The filter devices disclosed herein form an improved seal against the vessel wall that is activated by flowing blood. Devices described herein also allow for the closing of the ends of the filter device after capture of emboli, providing further security against accidental loss of emboli post capture. The TAVR procedure is just one application where the use of the devices, systems, and methods provides improved benefits. However, the devices, systems, and methods can be used in any portion of the body. 
     BACKGROUND OF THE INVENTION 
     Percutaneous coronary valve interventions, including both valve replacements and valve repairs, are a rapidly growing segment of catheter based medical interventions. Catheter based interventions have recently been a growing sector in cardiac interventions, and currently include mitral valve repairs and aortic valve repairs and replacements. One segment of this growing market is aortic valve replacements, referred to as Transcatheter Aortic Valve Replacement (“TAVR”). While TAVR procedures are increasing in frequency and with much success, the procedure has a risk of dislodging a clot or thrombi within the vasculature, in the form of thrombus and/or pieces of stenosis. These clots can potentially cause ischemic cerebral stroke if they travel to the brain, lungs or to the peripheral vessels. 
     Efforts have been taken to reduce the risk of stroke through the development of medical devices designed to prevent the dislodged clot from traveling to the brain. While these devices have met some success, there remains significant need for further refinement and improvement. 
     The previous devices generally fall into two classifications: deflector devices, and capture devices. Deflectors act to “deflect” thrombus away from critical vessels that lead to the brain, and usually entail deploying a nitinol mesh material (or similar) to prevent passage of the thrombus/stenosis fragment into critical vessels leading to the brain. A physician will temporarily deploy the mesh material over the origin of the vessels leading to the brain, so that blood can continue flowing but clot causing materials cannot get through the mesh pores (usually around 100 microns pore size). Since the clot material is not captured, it travels elsewhere in the body, usually down the ascending aorta and into the peripheral vasculature. For example,  FIG. 1A  illustrates an aortic arch  2 , left subclavian artery  4 , left common carotid artery  6 , and brachiocephalic trunk (innominate artery)  8 . The left common carotid artery  6  and the brachiocephalic trunk  8  supply blood to the head and neck. Therefore, any migration of emboli  30  poses a risk if the emboli  30  travel through these arteries and into the brain. 
       FIGS. 1A to 1C  show examples of conventional vascular protection devices. For example,  FIG. 1A  shows a capture device called the Sentinel™ by Claret Medical. As illustrated, the capture device is positioned within the left common carotid artery  6  and the brachiocephalic trunk  8  to prevent emboli  30  from migrating. However, it has been published in the medical literature that these filters do not adequately fit within the anatomy in at least 10% of the cases, which creates a risk from emboli passing.  FIGS. 1B and 1C  show examples of deflector devices  24 ,  26 . As shown, the deflector devices  24 ,  26  prevent emboli from entering the branching vessels. Moreover, if any of the conventional devices do not form an adequate seal against the vessel wall, thrombi can pass by the device (i.e., between the device and the vessel wall) and flow to the brain, causing cerebral ischemic strokes. 
     There are additional limitations with deflectors devices. First, in most devices, clot material is not captured or removed from the body. While it is advantageous to prevent the clot material from traveling to the brain and causing an ischemic stroke, the device deflects clots to the peripheral vessels. While less dangerous, the clots can still lead to blockages in the legs, renal vessels, etc. Additionally, the deflector devices also do not form an effective seal in the vasculature, meaning that while some or even most of the clot might be prevented from entering the vessels leading to the brain, a clot can still pass by the device creating a risk of a stroke. 
     Apart from the above, conventional capture devices have more additional limitations. Some of the capture devices do not protect all of the vessels leading to the brain (there are three main vessels that branch from the aorta and lead to the brain: the brachiocephalic artery which then feeds the right subclavian and right common carotid arteries, the left common carotid artery, and the left subclavian artery). The Sentinel device, made by Claret Medical (Santa Rosa, Calif.) protects only 2 of the 3 branching vessels. Other capture devices, such as the Emboliner device, made by Emboline (Santa Cruz Calif.) uses a nitinol mesh cylinder to attempt to provide coverage across all three branching vessels, but may fail if the seal between the mesh cylinder and the aortic wall is suboptimal, and allow clot to pass between the mesh cylinder and vessel, allowing clot to flow to the brain and cause stroke. 
     In fact, sub-adequate contact between the deflector/capture device and the vessel wall is a problem for all of the current cerebral protection devices. The imperfect seal allows for the passage of small clots to the brain creating a risk of stroke. Current medical literature states that these filters do not adequately “fit” the anatomy in at least 10% of cases. 
     Another limitation of the current capture devices is the risk that, once captured, the clot can potentially dislodge and travel back into the bloodstream. Both the Sentinel device and the Emboline device capture clot, but the distal end of the device remains open. Upon removal of the device from the body at the end of procedure, clots can migrate from the distal end. This could occur if the device collapses or geometrically distorts during removal, if the device scrapes against plaque and distorts during removal, or if the blood flow pulsations (so close to the heart) create flow distortions that dislodge the clot from the filter. 
     There remains a need for improved devices and methods to address the problems discussed above. While the discussion focuses on applications for protecting the cerebral vasculature, the improved devices and methods described below have applications for protecting any part of the vasculature. 
     BRIEF SUMMARY OF THE INVENTION 
     The examples discussed herein show variations of protection devices, systems, and methods that are suitable to protect vasculature, or other fluid filled passages, from debris caused during procedures that are performed upstream to the site at which the protection device is delivered, or the protective system and/or method is applied. The term emboli can include particles generated by blood clot, plaque, cholesterol, thrombus, calcifications, naturally occurring foreign bodies (i.e., a part of the body that is lodged within the lumen), a non-naturally occurring foreign body (i.e., a portion of a medical device or other non-naturally occurring substance lodged within the lumen.) However, the devices are not limited to such applications and can apply to any number of medical applications where protection of the vascular or passage is required. 
     Variations of the inventions described herein include protection systems for reducing migration of emboli within a blood flow of a vessel. For example, such a system can include a filter body having a distal portion and a proximal portion, where the filter body is configured for positioning within the vessel such that the blood flow enters the distal portion, wherein a wall of the filter body is porous to permit passage of the blood flow therethrough while capturing emboli within the blood flow; a sealing membrane located circumferentially on the distal portion, where the sealing membrane deflects from the filter body as a result of blood flow against the sealing membrane, wherein the deflection of the sealing member permits creation of a seal against a wall of the vessel; and a catheter body configured to navigate through the vessel, where the filter body is configured about an exterior of the catheter body. 
     In another variation, the inventions described herein include protection systems for reducing migration of emboli within a blood flow of a vessel. For example such a system can include a filter body having a distal portion and a proximal portion, where the filter body is configured for positioning within the vessel such that the blood flow enters the distal portion, wherein a wall of the filter body is porous to permit passage of the blood flow therethrough while capturing emboli within the blood flow; a sealing membrane located circumferentially on the distal portion, where the sealing membrane deflects from the filter body as a result of blood flow against the sealing membrane, wherein the deflection of the sealing member permits creation of a seal against a wall of the vessel; and a catheter body configured to navigate through the vessel, where the filter body is configured to re-enter the catheter body such that the filter body and emboli located therein are protected within the sheath body upon removal from the patient. 
     The sealing membranes can optionally comprise a fluid impermeable material. In some variations, the sealing membrane can have one or more openings to control building of pressure at the sealing membrane. A variation of the can comprise an expandable portion such that blood flow against the sealing membrane causes expansion of the expandable portion. In additional variations, the sealing membrane comprises a thin film polymer or elastomer. 
     The sealing membranes can be located within the filter body. Alternatively, or in combination, the sealing membranes can be located on an exterior portion of the filter body. In yet another variation, the sealing membrane is located on an interior diameter of the filter body and a second sealing membrane is located on an exterior of the filter body, wherein blood flow causes deflection of the sealing membrane to increase an effective sealing area of the filter device. In an additional variation, the sealing membrane comprises a first layer and a second layer, where the first layer is adjacent to an outer surface of the filter device and the second layer is adjacent to an interior passage of the filter device. In one variation the first layer is connected to the second layer such that blood flow into a region of the sealing membrane bounded by the first layer and second layer increases in pressure to further enhance opening of the sealing membrane. Additionally, or in combination, the first layer is configured to expand more than the second layer such that the sealing membrane expands outward from the filter device. 
     Variations of the filter device include a series of petals on a distal end of the filter body, where the sealing membrane is coupled to the series of petals. The series of petals can include at least one deflected petal and where the sealing membrane comprises a first layer coupled to the at least one deflected petal and a second layer coupled to the series of petals such that blood flow into a region between the first layer and second layer increases a pressure in the region. 
     The filter body can comprise a mesh braid or multiple layers of mesh braids. The mesh braids can comprise superelastic Nitinol. Alternatively, or in combination, the filter body comprises a thin film polymer or elastomer. 
     The filter body can comprise a pore size of 40 microns to 200 microns. 
     In additional variations, the sealing member further expands in response to blood flow. 
     Variations of the devices described herein can include a proximal sealing membrane within the filter body and located adjacent to the proximal portion of the device. Alternatively, or in combination, the filter body comprises a sheet of material with controlled porosity. In additional variations, the filter body is composed of strips of material which overlay to form a continuous surface. 
     The devices described herein can include at least one pull wire coupled to the distal end such that application of a tensile force on the pull wire urges the distal end to a closed position. In additional variations, the device can further comprise at least one resilient ring located at a distal end of the filter body to bias the distal end in an open position in the absence of the tensile force. 
     Any of the systems and/or devices described herein can include a synching member configured to synch a portion of the filter body. 
     The present invention also includes methods for filtering a vessel for emboli dislodged during a procedure performed within the vessel of a patient. For example, such a method can include positioning a filter device at a deployment site in the vessel, where the deployment site is downstream of the procedure site, a distal portion of the filter device includes a sealing member; deploying the filter device such that a blood flow towards the filter device causes the sealing member to form a seal against a wall of the vessel and where a body of the filter device permits passage of the blood flow while restricting flow of emboli such that emboli within the blood flow is retained within the filter device; securing the filter device and emboli located therein within a catheter body after the procedure; and removing the catheter body, filter device, and emboli from the vessel. 
     The methods described herein can include advancing a second catheter through a proximal opening the filter device and constricting a proximal portion of the filter device about the second catheter to prevent emboli from between the second catheter and the proximal opening. 
     In additional variations, the methods can further comprise completing the procedure and withdrawing the second catheter from the filter device while constricting the proximal portion of the filter device about the second catheter, and upon removal of the second catheter from the filter device, further constricting the filter device to prevent escape of emboli from the proximal opening. 
     In one variation of the methods, securing the filter device and emboli located therein comprises withdrawing the filter device within the catheter body. 
     The methods can also further include restricting a distal opening of the filter device prior to withdrawing the filter device within the catheter body. 
     In an additional variation of the methods, the filter device comprises a proximal sealing member, wherein the blood flow causes the proximal sealing member to form a proximal seal against the second catheter. In an additional variation of the method, the filter device is affixed to a distal end of the catheter body. 
     The methods can also comprise, prior to deploying the filter device, inverting the filter device within the catheter body, and wherein deploying the filter device comprises securing a proximal end of the filter device within the catheter body while withdrawing the catheter body relative to the filter device such that the filter device everts into position within the vessel. 
     In another variation of the methods, prior to deploying the filter device, the filter device is inverted within the catheter body, and wherein deploying the filter device comprises advancing a proximal end of the filter device out of the catheter body such that the filter device everts into position within the vessel. 
     A variation of the methods can also include advancing a second catheter through the catheter body and filter device to perform the procedure. In an additional variation, the method can further comprise restricting a distal end of the filter body to prevent emboli from passing through the distal end. In another variation, the method can further comprise withdrawing the distal end of the filter body into the catheter body such that the filter body inverts within the catheter body. 
     In an additional variation of the method, after deploying the filter device, a balloon catheter or bristle-brush device is used to loosen emboli from a procedure site, in order to ensure capturing of emboli within the filter body. 
     The methods include positioning the filter device an aorta. The methods can include advancing the filter device and catheter body through a radial vessel or advancing the filter device and catheter body through a femoral vessel. 
     In another variation, the methods can further include passing a portion of the blood flow exterior to a body of the patient, through an external filter, and returning the blood flow back to an artery in the patient. 
     Another variation of the methods described herein include advancing a filter device to a deployment site in the vessel, where a distal portion of the filter device includes a sealing member; deploying the filter device in proximity to the procedure site, where the filter device permits the passage of blood therethrough; forming a first seal between a wall of the vessel at the deployment site using the sealing member causing a flow of blood into the filter device; advancing a medical device through the filter device to the procedure site; performing a procedure in the vessel distally to the filter device using the medical device, where the procedure causes emboli in the flow of blood; withdrawing the medical device from the deployment site and further restricting the proximal portion of the filter device such that emboli remains within the filter device; positioning the filter device and emboli located therein within a catheter to prevent passing of emboli into the blood flow; and removing the catheter, filter device, and emboli from the patient. 
     Variations of the methods described herein can further include constricting a proximal portion of the filter device about the medical device to form a second seal about the medical device after advancing the medical device through the filter device. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Each of the following figures diagrammatically illustrates aspects of the invention. Variation of the invention from the aspects shown in the figures is contemplated. 
         FIGS. 1A to 1C  show examples of conventional vascular protection devices. 
         FIGS. 2A to 2I  illustrates an example of the flow assisted sealing of the present disclosure. 
         FIG. 3  shows a variation of a filter device  100  a collar comprising a lasso-type mechanism that can adjust a diameter of a portion of the device. 
         FIGS. 4A to 4I  illustrate examples of flow activated seals. 
         FIG. 5A  illustrates a conventional capture device expanded against a wall of a vessel. 
         FIG. 5B  an improved filter device with a flow-activated seal expanding against the wall of a vessel. 
         FIGS. 6A and 6B  show a variation of a device having a proximal flow activated seal that is located at a proximal region of the filter device. 
         FIGS. 7A-7G  illustrate an additional variation of a filter device that is integrated with a system that is delivered from the femoral artery through the aortic arch. 
         FIGS. 8A to 8E  show another variation of a filter device incorporated directly into the procedural device. 
         FIGS. 9A to 9C  illustrate additional configurations for restricting one or both ends of the filter device. 
         FIGS. 10A to 10C  illustrate the use of one or more balloons that control an opening of a filter device. 
         FIGS. 11A to 11C  illustrate an additional variation of filter devices that uses a lasso-effect to close an end of the filter. 
         FIGS. 12A to 12C  illustrate another variation of a filter device that is integrated with a guide catheter and constrained within an outer sheath. 
         FIGS. 13A to 13C  illustrate variations of a filter body for use with the devices described herein. 
         FIGS. 14A to 14E  show another variation of a filter device with a multi layer seal. 
         FIG. 15  illustrates a variation of a filter device configured for an exterior of a guide catheter or sheath. 
         FIGS. 16A to 16C  illustrate additional variations of devices for use with the procedures described herein. 
     
    
    
     DETAILED DESCRIPTION 
     It is understood that the examples below discuss uses in the aortic arch to protect cerebral vasculature (namely the arteries). However, unless specifically noted, variations of the device and method are not limited to use in the cerebral vasculature. Instead, the invention may have applicability in various parts of the body. Moreover, the invention may be used in various procedures where the benefits of the method and/or device are desired. 
       FIGS. 2A to 2I  illustrates an example of the flow assisted sealing of the present disclosure. In this variation, a guidewire  110  advances through the left subclavian artery  4  to permit positioning of a filter system (not shown in  FIG. 2A ) using a radial artery approach. Such an approach allows a TAVR system to be delivered from a femoral artery without the filter system reducing the available space within the vessel. Many TAVR systems are large, typically 12-18 French in diameter, so variations of a filter system that is also delivered from the femoral artery might compete for space within this vessel. Delivering the filter system from the radial artery allows for the space within the femoral artery to accommodate the TAVR system and other necessary devices. 
     The seal, filter device and/or guide catheter can have any number of coatings to minimize thrombogenicity, minimize platelet activity, or provide other drug eluting benefits as needed. Alternatively, or in combination, the seal, filter device and/or guide catheter can include a hydrophilic coating. 
     As shown in  FIG. 2A , a guidewire  110  can be introduced from a radial artery through the left subclavian artery  4 , into the aortic arch  2 , to the aortic valve  10 . A guide catheter or guide sheath  112  can be introduced over the guidewire  110  and advanced to a site for deployment of the filter device, which can be downstream of the procedure site (as shown in  FIG. 2B ). In this example, the procedure site is the location of the valve  10 . As noted, the guide catheter  112  can be introduced over the guidewire  110  while containing the collapsed filter system (not shown yet). Alternatively, the filter system can be advanced through the guide catheter  112  when the guide catheter  112  is properly positioned. Exemplary variations of the guide catheter  112  can range from 4 F to 8 F in diameter. However, any size can be used as needed. Moreover, the distal region(s) of the guide catheter can be pre-shaped with bends and angles to facilitate navigation in a desired region of the anatomy. For instance, the guide catheter  112  can have a bend proximate to the distal end to accommodate entry into the aortic arch  2  and to allow advancement of the distal end towards the valve  10 . 
       FIG. 2C  illustrates initial deployment of a filter device  100  at a deployment site in the path of blood flow  12  from the procedure site (e.g., the valve  10 ). The filter device  100  can be deployed by applying a force on the device  100  to urge it out of the delivery catheter  112 . Alternatively, the guide catheter  112  be pulled relatively to the filter device  100  to expose the filter device  100  at the desired deployment site. Variations of the filter device  100  are constructed from a super elastic Nitinol mesh, that is heat set to expand to the arterial surface (typically 2.5 cm to 3.5 cm in the aortic arch  2 ). 
     In one variation of the filter device  100 , the Nitinol mesh is a single layer of woven Nitinol wires. Additional variations of the device  100  can comprise multiple mesh layers of Nitinol overlaying one another. The Nitinol wires can be round, square, or rectangular in cross section, as well as triangular, half-round, or any combination thereof. Such irregular shapes may be preferential for limiting thrombogenic responses, as the blood patterns and flow properties may be changed due to wire shape. 
     Additionally, some portion of the wires could be composed of DFT (Drawn Filled Tube), where the Nitinol wire contains a core of gold, platinum, or tantalum (or similar) for radiopacity. Alternatively, individual wires of the mesh can be composed of solid or hollowed platinum, gold, and/or tantalum for radiopacity. Gold, platinum, and/or tantalum rings may also be used for radiopacity. 
     In one variation of the filter device  100 , the nitinol mesh has a a pore size of around 100 microns, although a range of about 40 to 200 microns, or even larger, could also be appropriate. 
       FIG. 2C  also illustrates the filter device  100  having a flow-seal  102  located at a distal end  122  of the filter device  100 . This flow-seal  102  is activated by blood flow  12  into the device. Variations of the flow-seal comprise a section of impermeable soft polymer membrane that expands as blood flows into the membrane. The blood flow  12  causes the flow-seal to expand against the arterial wall to create a tight seal, which prevents the passage of emboli that are located within the blood flow  12 . As noted above, conventional protective devices can fail to create a tight seal between filter device  100  and vessel wall, which allows emboli to escape the protective device. As noted above, the wall of the aorta is usually calcified and contains plaque deposits, which creates a geometrically irregular surface that makes it difficult to form an appropriate seal using conventional devices. The flow seal shown in  FIG. 2C  avoids problems associated with conventional devices by using the naturally occurring blood flow  12  to expand the flow-seal  102  membrane and create a tight seal, which requires that emboli pass into the opening of the filter device  100 . Additional variations of the flow-seal are discussed below. 
       FIG. 2D  illustrates a variation of a filter device  100  having an adjustable collar  104  at a proximal end of the device  100 . The collar  104  can position the device as well as adjust a diameter of the proximal end  120  by application of a force on the connecting wire  106  that extends through the guide catheter  106  and through the left subclavian  4  and radial arteries. The restriction collar  104  can be used to clamp down tightly onto a catheter or device (such as a TAVR guide catheter discussed below) that is inserted into the proximal opening  122  of the device  100 . Variations of the device  100  can include a polymeric liner on the ID of the mesh at or near the collar  104  location to ensure a tight seal against the catheter or device that extends therein. In one variation, the collar  104  can comprise a push-pull ribbon that controls the diameter of the filter device  100 . Alternatively, as discussed below, the collar can include, or is replaced with, any number of ring structures that control the diameter of the filter device  100 . 
       FIG. 2E  shows the deployed filter device  100  in place to receive a second catheter  130  that will be used to complete a procedure within the vessel. In the illustrated example, a TAVR system is introduced through a femoral artery with the TAVR guidewire  138  advanced into the proximal opening  120  of the device  100  and through the distal opening  122  to the procedure site (again the valve  10 ). Again, as discussed above, the filter device  100  maintains a circumferential seal with the flow seal  102  that remains activated by the flow of blood within the vessel. Next, as shown in  FIG. 2E , a TAVR guide catheter  130  and TAVR valve  132  with balloon  134  are advanced along or over the TAVR guidewire  138 . In alternate variations, additional devices (not shown), such as a pig tail catheter, infusion catheter, or pressure monitoring catheter or guidewire can be delivered or advanced through the filter device  100 , which can accommodate multiple devices. 
       FIG. 2F  illustrates a state where the TAVR guide catheter  130  passes through the filter device  100  and the TAVR valve  132  is positioned within the aortic valve  10 . Once the TAVR (or other devices for the appropriate procedure) is positioned, the medical practitioner can restrict the collar  104  to form a seal against the TAVR guide catheter  130 . The seal can be tight or can be sufficient to continue to allow the TAVR catheter  130  to slide therein. In some variations, a tight seal is essential for ensuring that emboli  30  trapped by the filter device  100  remain contained inside the filter mesh. As stated previously, a polymer ring or other structure on the ID of the filter at the location of the collar can be used to further enhance the seal. It should also be noted that the collar  104  can be substantially restricted as soon as the TAVR guide  130  enters the filter  100 , while allowing sliding of the TAVR guide  130  relative to the collar  104 , and then further restricted to form a tight seal once the TAVR guide  130  and TAVR valve  132  are in place. 
       FIG. 2F  illustrates the situation where the TAVR valve  132  is deployed against the aortic valve, and the TAVR delivery catheter  130  is being withdrawn from the procedure site. As shown, the procedure can cause embolic particles  30  to being to migrate within the vessel. However, the flow-seal  102  will direct any embolic particle  30  flowing in the blood into the distal opening  122  of the filter device  100 . Therefore, the filer device  100  traps and contains many of the embolic particles  30  that would otherwise travel to other parts of the body such as the brain, where an embolic particle could cause an ischemic stroke. 
       FIG. 2G  shows the state after the procedure where the TAVR implant  132  is positioned at the valve  10  and where the TAVR balloon and TAVR wire are removed from the filter device  100 . This leave only the TAVR guide  130  through the filter device  100 . (Note: guidewire may or may not be removed prior to TAVR guide catheter removal).  FIG. 2H  shows the filter device  100  after the TAVR guide is removed but where the collar  104  further constricts the proximal portion of the filter device  100  to effectively completely close the proximal end of the filter  100 . This ensures that the trapped embolic material  30  cannot escape through the proximal opening  120  of the filter device  100 . 
     It should also be noted that a physician could elect to keep the filter device  100 , as shown in  FIG. 2H , in place for several hours or even days after the procedure as a precautionary means to collect any late-breaking plaque from the aortic valve. This would further provide protection against stroke. 
       FIG. 2I  illustrates a condition where the filter device  100  is ready for removal. The filter device  100  can be withdrawn into the guide catheter  112 . Alternatively, the guide catheter  112  can be advanced over the filter device  100 , resulting in collapse of the filter device  100  as it is constrained inside the guide catheter  112 . Since the filter device  100  is constrained inside the guide catheter  112 , the embolic particles  30  are now protected from escaping. Once secured, the guide catheter  112  and filter device  100  are removed. 
       FIG. 3  shows a variation of a filter device  100  having a collar comprising a lasso-type mechanism that can adjust a diameter of a portion of the device  100 . As shown, the filter device  100  can include a proximal lasso  152  and/or a distal lasso  154 . Each lasso can be independently adjusted using one or more wires  156 ,  158  that are extended through the guide sheath  112 . In the illustrated variation, each lasso member  152 ,  154  is shown to include two pull wires. However, variations of the filter device  100  include a single pull wire for each lasso or more than 2 pull wires for each lasso member  152 ,  154 . The benefit of having separate control wires for each lasso member  152 ,  154  is that the proximal and distal ends of the filter device  100  can be independently controlled. 
       FIGS. 4A to 4C  illustrate some examples of flow activated seals  102 . In one variation, the flow activated seal  102  comprises a soft polymer membrane that can expand in response to the pressure caused by the blood flowing against the membrane. The pressure causes deflection and/or expansion of the membrane. In some variations, the flow activated seal  102  only partially deflects and/or expands. 
       FIG. 4A  shows a variation of a device  100  having a polymer layer that forms the flow activated seal  102 . As shown in  FIG. 4B , the flow of blood  12  causes expansion and/or deflection of the membrane  102 , which creates increased surface contact with the inner wall of the vessel not shown. Variations of the flow activated seal can simply unfold from the body of the filter device. Alternatively, or in combination, the flow activated seal (e.g., a center portion that is not attached to the filter body) can stretch or expand upon receipt of the flow of blood. In additional variation, the flow activated seal is flow impermeable such that the flow against the seal increases pressure at the seal. In addition, the flow activated seal typically comprises a softer, more compliant material as compared to the mesh of the filter device. This difference allows the flow activated seal to conform to any irregularities on the vessel wall. This allows the filter device to form an improved seal against the vessel wall. Variations of the filter devices  100  can include flow activated seals  102  that provide increased friction when expanded/deflected against the vessel wall. For example, the membrane  102  can include a roughened surface texture or particles that increase resistance to movement of the filter device in response to the blood flow. These expandable sealing members can be distensible or non-distensible. 
       FIG. 4C  illustrates another variation of a flow activated seal  102  in a filter device  100  where blood flow causes the seal  102  to balloon or expand outwards from the mesh forming the device  100 . 
     Variations of the flow activated seals  102  membrane can be fabricated from thin film polymer or elastomer, or similar materials. A thermoplastic urethane could be very suitable, as could other thermoplastic elastomers. Variations of the devices include membranes about 0.001″ in thickness. Alternatively, variations of the membranes can include thicknesses of 0.0003″ to 0.003″. The membranes can be processed with a “redundancy” such as folds or extra slack, to further enhance the ease and size of the opening of the membrane. 
       FIG. 4D to 4G  illustrate additional configurations of a flow-activated seal  102 . In  FIG. 4D , the flow activated seal comprises an elastic polymer positioned on the interior of a braid structure forming the filter device  100 . As shown in  FIG. 4E , as blood flow  12  enters the filter device  100 , the blood flow  12  deflects/displaces the polymer material along with a portion of a mesh  108  forming the filter device  100 . Therefore, the blood flow  12  forces the polymer and mesh  108  to expand and form aa seal against the vessel wall. 
       FIG. 4F  illustrates another variation where the polymer layer or membrane is located within a filter device  100 . As shown a soft, ultra-compliant polymer (such as urethane or another thermoplastic elastomer TPE) forms a shape within the filter device  100  that captures blood flow  12  using a dual layer configuration that includes an upper seal surface  166  and a lower seal surface  168 . The seal  102  shown in  FIG. 4F , for example, includes a large upper sealing surface  166  adjacent to an outer surface of the filter device  100  and a smaller lower sealing surface  168  adjacent to an inner passage of the filter device  100 . As blood flows into the space between the upper  166  and lower  168  sealing surfaces, the pressure inside (i.e. between the two surfaces) increases in fluid pressure, which helps the seal  102  to advance outward against the vessel as shown in  FIG. 4G . In one variation, the lower sealing surface  168  is intentionally smaller than the upper, to ensure that the upper surface  168  expands more than the lower  166 . However, alternate variations permit design selection to allow the upper surface  166  to expand more than the lower surface  168 . As shown in  FIG. 4G , the blood flow  12  enters the membrane  102  to cause deflection and displacement such that the filter device  100  seals against the arterial wall. 
       FIGS. 4H and 4I  illustrate a variation of a filter device  100  having a first flow activated seal  102  with a secondary seal  114 . In this variation, the flow activated seal  102  is located within the filter device  100  while the secondary seal  114  is located on an exterior of the device  100 . Since each layer  102  and  114  is affixed to the two layers of the mesh filter  108  when blood flows  12  (as shown in  FIG. 4I ), the flow  12  increases a pressure on the surface of the inner membrane  102  to deflect and push on the outer membrane  114 . The two membranes  102 ,  114  form a seal at the area where they overlap. This configuration comprises two separate seals  102  and  114  that function as a single seal or single layer. 
     While the variations of the flow activated seal discussed herein are shown in relation to the distal portion of the filter device, additional variations of filter devices include flow activated seals on the proximal region of the filter device as well. Such a proximal flow activated seal can further assist in sealing the filter device against the guide catheter or other device advanced therethrough. In such cases, the design of the proximal flow activated seal will be actuated by blood flowing into the distal portion, through the filter device, and towards the proximal portion. 
     The flow activated seal provides significant advantage when used in a protection device by decreasing the likelihood that an embolic particle will bypass the device.  FIGS. 5A and 5B  illustrate the difference between conventional devices (such as those shown in  FIGS. 1A to 1C ) and the improved filter devices  100  discussed herein.  FIG. 5A  illustrates a cross sectional view of a vessel  2  (the scale of the drawing is adjusted to better illustrate the fit of the device  22  against a wall  14  of the vessel). As shown, the perimeter of the device  22  is intended to form a seal against the vessel wall. However, irregularities  16  in the vessel  2  (such as plaque, calcification, shape of the vessel, or other naturally occurring formations) result in irregular geometries  18  that cannot be sealed with the protection device.  FIG. 5B  illustrates a feature of the flow activated seals  102  of the present disclosure where the seal often has a softness or conformability that is greater than the mesh structure forming the device  100 . This feature allows the flow activated seal  102  to expand or deform into any irregularities  18  in the vessel  2  at a greater degree than the mesh or filter device  100 . This creates an improved seal between the wall  14  of the vessel  2  and the filter device  100  to improve filtering of emboli within the blood stream with an enhanced seal. 
       FIGS. 6A and 6B  show a variation of a device having a proximal flow activated seal  116  that is located at a proximal region of the filter device  100 , much like the distal seal. Note that collar is shown as being adjacent to the seal  116 . However, variations of the filter device  100  can include a proximal seal  116  located in any part of the proximal portion. Any one of the seal designs disclosed herein for the distal seal could also be used at the proximal location, or some combination thereof as long as they seal flow from the distal portion of the device. 
       FIGS. 6A and 6B  also show a variation where the proximal seal  116  includes an attachment  118  that connects the seal back to the braid. This connection prevents inversion of the seal  116 . In the illustrated variation, drawing, the seal  116  is permanently fixed to the braid where shown (i.e., adhesive bonded, thermal-mechanical encapsulation, etc.). To ensure the opposite end of the seal does not invert, either from blood flow  12  or from withdrawing the guide catheter, the seal can be additionally tethered  118  to another region of the braid. Tethering can be accomplished with a tack melt, additional encapsulation/thermal fuse, or using additional fibers or polymer or metal filaments. 
     Another variation of the system can include an enhanced TAVR guide catheter  130  in a manner that enhances the sealing properties of the filter. A geometric “bump” or protrusion  138  could be on the OD of the guide  130  in the sealing region. In the variation shown in  FIG. 6A , the protrusion  138  is shown outside of the filter device  100  for illustrative purposes. The protrusion  138  can be manufactured into the catheter  130 . Alternatively, or in combination, the protrusion can be added to the TAVR guide catheter  108  in the sterile environment (such as a small sterile sleeve). Additionally, a swellable coating, such as a thick hydrophilic coating, could also perform a similar effect of increasing the proximal seal. 
       FIGS. 7A-7G  illustrate an additional variation of a filter device  100  that is integrated with a system that is delivered from the femoral artery through the aortic arch  2  to the valve  10 . In this variation, the filter device  100  is integrated and permanently fixed to a guide catheter  140 .  FIG. 7A  shows an example of a variation of a system with a filter device  100  integrated with a guide catheter or sheath  140  that is advanced to a deployment site within a vessel  2 . In this variation, the filter device  100  is inverted within the guide sheath  140  and where a proximal end of the device  120  is affixed to a distal end  142  of the guide catheter  140 . As shown in  FIG. 7B , a stabilizing device  170  (e.g., a dilator device or support catheter) advances to the distal end  122  of the filter device  100 .  FIG. 7C  shows a condition where the guide  140  is withdrawn while the stabilizing device  170  stabilizes the filter device  100  such that it everts into position as the guide sheath  140  is withdrawn. The stabilizing device  170  can also be used to ensure filter is fully reverted into an open or deployed shape by extending it through the filter device  100 .  FIG. 7C  shows the distal portion  122  of the device  100  with a flow activated seal and the proximal portion  120  of the device  100  coupled to the distal end  142  of the guide catheter  140 . 
     The use of a stabilizing device  170  allows for either “extruding” of the filter by using the stabilizer/dilator  170  to push the filter  100  distally. Alternatively, the stabilizer/dilator  170  could be advanced to the inverted filter at the proximal end to stabilize the filter, and then an outer sheath constraining sheath could be withdrawn proximally to unsheath the filter. 
     Next, as shown in  FIG. 7D , the TAVR implant  132  and system  130  advances through the guide catheter or sheath  140  with the integral filter device  100 . The distal end  122  of the filter  100  contains the flow activated seal  102 .  FIG. 7E  illustrates the TAVR implant  132  deployed at a deployment site with emboli  30  in the flow of blood but is directed into the filter device  100  because of the flow activated seal  102 . There is no risk of the emboli escaping through the proximal end  120  of the device  100  since the proximal end is integral with the distal end  142  of the guide catheter  140 . 
       FIG. 7F  illustrates closing of a distal end  122  of the filter device  100  using one or more pull wires  124 . As illustrated, the embolic particles  30  are secured within the closed filter device  100  that is integral/secured to the guide catheter  140 .  FIG. 7G  illustrates an optional feature of the system where the filter device  100  can be inverted back into the guide catheter  140 . As shown, the pull wires  124  are tensioned to bring the distal portion  122  of the closed filter device  100  back into the catheter body  140 , which causes inversion the filter device  100  into the guide body  140 . Again, there is no risk of losing captured emboli, since the filter is closed. Such a step could ensure filter and emboli are protected during removal from body. 
     It should also be noted that additional design options include building the filter onto the femoral introducer sheath (i.e., long sheath with filter located near aortic valve) or using a long sheath to constrain the filter if it is not pre-inverted in the guide catheter. 
       FIGS. 8A to 8E  show another variation of a filter device incorporated directly into the procedural device. For example, the filter device can be built directly into the TAVR guide catheter, which eliminates the need for an additional guide catheter for the filter alone.  FIG. 8A  illustrates a TAVR guide catheter  130  that is used to advance the TAVR implant  132  to the site of the valve  10  within the aorta  2 . FIG.  FIG. 8A  does not show the filter but is loaded inside TAVR guide catheter  130 . 
       FIG. 8B  shows the filter device  100  delivered from the TAVR guide catheter  130 . This deployment can be accomplished in any of the ways disclosed herein (inverted inside the guide catheter and delivered by ‘pushing’ with another integrated tube or similar; or simply compressed within TAVR guide catheter and unsheathed).  FIG. 8C  shows the TAVR balloon and guidewire removed from the site. Since the filter device  100  is mechanically integrated to the catheter body  130 , there is no concern that emboli can escape through the proximal region of the filter device  100 .  FIG. 8D  illustrates one or more guidewires  124  that are used to close a distal end  122  of the filter device  100 . The proximal end of the filter device  100  is positioned within the distal end  128  of the TAVR guide catheter  130 .  FIG. 8E  illustrates a variation where the filter device  100  is coupled to be slidable within the TAVR guide catheter  130 , which allows closed filter to be brought back into guide lumen while being removed. 
     The variations shown in  FIGS. 7A-7G and 8A-8E  are systems that can be constructed either into a delivery guide catheter of the TAVR system or into separate delivery catheter. 
       FIGS. 9A to 9C  illustrate additional configurations for restricting a filter device  100 . In the example shown in  FIG. 9A , the filter device  100  comprises a double mesh layer with an inner mesh  108  and outer mesh  109 . In one example the mesh layers  108 ,  109  comprise Nitinol braids. An additional ring structure  160  is provided at an end of the filter device  100 . In the illustrated example, the ring structure  160  comprises a coil shape. However, alternative shapes (e.g., straight wire, sinusoidal, helical, etc.) can be used as long as the shape provides an outward radial force to maintain the end of the filter  100  in an open configuration. One or more pull wires  156  are coupled to the ring  160  such that the application of a force on the pull wire  156  closes the ring  160  and the end of the filter device  100 . The illustrated example shows the pull wire  156  extending through a tube (e.g., a polyimide tube).  FIG. 9B  shows a ring structure  160  coupled with a pull wire  156  without the mesh of the filter device. As noted above, the coiled ring  160  provides an outward radial force that opens the end of the filter device when unconstrained. Application of a force  52  on the wire  156  away from the ring  160  causes closure  54  of the ring  160  and the filter device. As noted above, the coiled ring  160  provides an outward radial force that opens the end of the filter device when unconstrained. Application of a force  52  on the wire  156  away from the ring  160  causes closure  52  of the ring  160  and the filter device. 
       FIG. 9C  shows another variation of a self-expanding ring  164 . In this variation, the ring is in an undulating shape with a pull wire  158  passing through the ring  164 . As noted above, the ring  164  is self-expanding (or heat activated) to provide an outward expanding force on the filter device  100 . The pull wire  158  acts to close the ring  164  and filter device  100  upon the application of a closing force. The pull wire  158  can optionally pass through a tube  162  or can be incorporated into the mesh of the filter. 
     It is noted that any of the ring designs discussed herein can be used interchangeably for the distal and/or proximal regions of the filter, or any combination thereof. In addition, the ring designs can be incorporated at any medial portion of the filter if required. 
       FIGS. 10A to 10C  illustrate the use of one or more balloons that control an opening of a filter device  100 . For example,  FIG. 10A  illustrates a variation of a filter device  100  having an elastomeric balloon  180  at an end of a filter device  100 . In this variation, the balloon is in a closed position (as shown) when not pressurized. Application of a fluid through a line  184  causes the balloon  180  to expand  188  to open the filter device  100 .  FIG. 10B  illustrates another variation of a filter device  100  having a balloon  182  that is in a normally open position. Application of a fluid through line  184  causes the balloon  182  to collapse inwards as shown in  FIG. 10C . 
       FIGS. 11A to 11C  illustrate an additional variation of filter devices that uses a lasso-effect to close an end of the filter. Again, all of the closing mechanisms discussed herein can be applied to a proximal, distal, and/or medial portion of the filter device.  FIG. 11A  shows a pull wire  156  used to create an aperture or opening at an end of the filter device  100  that can be restricted/occluded by pulling on the wire  156 . Pulling of the wire  156  reduces the diameter of the filter device  100  and effectively closes the attached portion of the filter  100 . In this variation the wire  156  is located at the distal end of a guide catheter  140  with an integrated filter device. However, this closing structure can be used on any filter device. In addition, these concepts can apply equally to the proximal end of a filter as well. 
     As noted above, in order to prevent the spreading of emboli, some applications of the device require the closing mechanism to completely and fully close off the open end of the filter. In such applications, the wire  156  can be constructed from a superelastic nitinol wire with oxide coating, about 0.001″ to 0.002″, but variations of the device allow for up to 0.010″. Wire could also be ribbon wire, rectangular, or other shape. Fiber or polymer or thread are also options.  FIG. 11B  shows two sets of pull wires  156  coupled to the distal end of the filter device  100 .  FIG. 11C  shows multiple sets of pull wires  156  that close the end of the filter device. 
       FIGS. 12A to 12C  illustrate another variation of a filter device  100  that is integrated with a guide catheter  140  and constrained within an outer sheath  190 .  FIG. 12A  shows a filter device  100  and guide catheter  140  constrained within an outer sheath  190  so that the system can be advanced to a deployment site as discussed herein. This variation is typically delivered from the femoral artery, where the TAVR system is delivered.  FIG. 12B  shows the outer restraining sheath  190  being withdrawn  192  while the guide catheter  140  is held stationary. Withdrawing the constraining sheath  190  causes the filter device  100  to expand. As noted above, the flow activated seals will ensure proper filtering of the vessel. This is a two-catheter design, or coaxial system, where one catheter  140  is integrated with the filter device  100 , and one catheter/sheath  190  acts to constrain the filter  100  for delivery. Variations of the system include replacing the outer sheath  190  with another mechanism, such as a coil or short collar, to constrain the filter. In additional variations, the outer sheath  190  could be very thin, such as a coil reinforced polyimide tube, in cases where it is only intended to constrain the filter and does not need to navigate on its own.  FIG. 12C  shows activation of the pull wire  156  after completion of the procedure. Activation of the pull wire closes the end of the filter device  100  to secure any embolic particles within the filter  100 . 
       FIGS. 13A to 13C  illustrate variations of a filter body for use with the devices described herein.  FIG. 13A  shows a dual layer filter device  100  with the outer layer comprising a mesh  108  or a thin film porous material, such as a polymer film with holes or pores (e.g., laser drilled, chemically formed, mechanically formed) and the inner layer comprising a coil or braid  148  that is designed for providing radial force such that the filter body  100  expands with radial force to contact the wall of the vessel.  FIGS. 13B and 13C  respectively illustrate a non-expanded and expanded filter device  100  comprising an inner inflation member  150  with a mesh or braid  108 . The coiled inflation member  150  expands and opens the braid upon inflation. It should also be noted filter device  100  can be made from components other than wire braid or mesh. For example, the filter device  100  can comprise a porous polymer film, such as polyurethane or a similar material. Porosity of the film can be achieved with laser processing, chemical etching or other chemical treatment, or micro abrasion processes, or other means known to those skilled in the art. In another variation, the filter device is constructed from a thin film process. The thin film such as a thin film metal can be made with a custom selected porosity. The filters shown in  13 A to  13 C provide multiple layers where the inner layer (e.g., the coil, braid, stent-like structures) provides an outward radial force to open the filter and the outer layer (e.g., braid, polymer, porous film, porous metal film) provides the filtration for blood. 
       FIGS. 14A to 14E  show another variation of a filter device with a multi-layer seal. In this variation, as shown in  FIG. 14A , the mesh  108  of the filter device  100  terminates in a series of petals  105 ,  107 . The construction of the petals  105 ,  107  can include separate wires or wires from an inner/outer mesh that returns back to form an outer/inner mesh. The petals can be atraumatic or can include features that increase friction against the vessel wall (or wall of the body lumen).  FIG. 14B  illustrates alternating petals  107  being shaped with an offset  126  e.g, alternating petals  107  are shaped to extend upward  126 , and then next petal  105  can either be horizontal (as shown), or even extend slightly downward (into the ID of the device  100 ) as shown in  FIG. 14C . This angulation and separation of the petals creates a space to attach the flow activated seal  102 . As shown, the seal  102  can have both an upper surface  164  and lower surface  165 . In one variation the seal  102  can be formed from a single section of polymer film or could be two independent pieces which meet at the apex and are overlapped. It is also possible that selective small “holes”  163  in the seal  102  could be beneficial to control the pressure inside the seal  102  and ensure that blood flow doesn&#39;t over-pressure the seal  102  and dislodge position of the filter device  100 . It should also be noted that this same design concept could be achieved with “standard” braid (i.e. no petals). In this case, individual braid wires would be formed to either extend outward or flat/inward, and then the ends of the wires would terminate within the seal polymer.  FIG. 14E  illustrates a partial side view of the upper seal  164  and lower seal  165  with a space therebetween for increasing pressure in response to blood flow. As noted herein, the upper seal  164  can be configured to preferentially deflect into a wall of the vessel (e.g., via sizing or material selection). 
       FIG. 15  shows another variation of a filter device  100 . Previous variations showed the filter device  100  attached at or near the distal end of the guide catheters. Here, the filter  100  is attached to the outside of the guide  174 . The filter  100  could be self-expanding (or mechanically assisted, as described before), and then opened by the conventional methods (releasing pull wire, activating coil or inflation lumen, or removing external sheath or covering). Once the collection of thrombi is completed, the filter  100  can be closed to the OD of the guide/sheath  174 , trapping the emboli between filter and guide surface. It should be noted that the guide  174  could be a procedural guide, TAVR guide, and or sheath. Sheath options include long introducer sheath, procedural sheath, and/or expandable sheath (i.e e-sheath). 
       FIGS. 16A to 16C  illustrate additional variations of devices for use with the procedures described herein.  FIG. 16A  illustrates a distal end of a TAVR guide catheter  144  with a distal end that is flared outward in multiple points  144 , presumably to keep contact on the proximal edge of the balloon and possibly even to have contact on the compressed TAVR valve. The guide  130  with inverted (or non-inverted, but simply compressed) filter could still have this flared distal end, as shown. The mesh of the filter device  100  can be folded into the guide catheter  130 . 
       FIG. 16B  shows an additional variation during or after the use with the filter devices described herein. In this example, after the filter is deployed in position (regardless of a radial or femoral approach), a custom catheter or guidewire with a “brush-like”  176  attachment advances to the procedure site to loosen any plaque or other debris from the procedure site (e.g., the valve or any other procedure site). The custom catheter  176  can be delivered to the procedure site (e.g., the aortic valve  10 ) prior to TAVR introduction. The brush attachment is one variation of a device that can loosen debris. For example, the brush device can have bristles or bristle-like protrusions, such as polymer fibers, arranged about the distal end. The protrusions “knock free” any loose plaque from the aortic valve prior to placing the new filter. This could be done to simply get a better fit of the new valve with respect to the aortic wall or could be done to minimize the likelihood of plaque breaking free post-procedure, especially after the filter might be removed. 
     Another option is to deploy the filter as shown in  FIG. 16B  (either femoral or radial approach) and pre-dilate the aortic valve with a balloon catheter. The expansion of the balloon can simply allow for a better fit of the new valve with respect to the aortic wall or can be performed to minimize the likelihood of plaque breaking free post-procedure. 
       FIG. 16C  shows a variation of returning blood through the catheter  112  extending from the left subclavian artery  4  and out of the radial artery. Once outside the patient&#39;s body, the blood can flow through a simple filter  196  with a similar pore size. Filters are readily available in paper, woven textiles, polymer, and thin film composite materials. The constriction ring or collar  104  can still be used at the proximal region to allow the passage of the TAVR system. Alternatively, this design configuration can also be used in the patient, post procedure, to collect any late breaking emboli. In this case, the constriction ring would be completely closed, forcing all of the blood through the catheter and filter. A portion of the filter can be made impermeable to control how much blood flows into the catheter/filter loop and how much flows into the other vessels. The filtered blood can be passed back into the body via e.g., a femoral access point  198 . 
     As for other details of the present invention, materials and manufacturing techniques may be employed as within the level of those with skill in the relevant art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts that are commonly or logically employed. In addition, though the invention has been described in reference to several examples, optionally incorporating various features, the invention is not to be limited to that which is described or indicated as contemplated with respect to each variation of the invention. 
     Various changes may be made to the invention described and equivalents (whether recited herein or not included for the sake of some brevity) may be substituted without departing from the true spirit and scope of the invention. Also, any optional feature of the inventive variations may be set forth and claimed independently, or in combination with any one or more of the features described herein. Accordingly, the invention contemplates combinations of various aspects of the embodiments or combinations of the embodiments themselves, where possible. Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “and,” “said,” and “the” include plural references unless the context clearly dictates otherwise. 
     It is important to note that where possible, aspects of the various described embodiments, or the embodiments themselves can be combined. Where such combinations are intended to be within the scope of this disclosure.