Abstract:
A valve prosthesis comprises a valve fixation device that comprises a plurality of struts that run in a direction substantially parallel to the longitudinal axis; a first circumferential row of cells coupled to the plurality of struts; and a second circumferential row of cells coupled to the plurality of struts. The valve fixation device is compressible to a compressed state for delivery to an implantation site, and expandable to an expanded state for deployment at the implantation site. The plurality of struts are substantially rigid such that the plurality of struts do not change dimensions between the compressed state and the expanded state. The valve prosthesis also comprises a valve comprising a plurality of leaflets and a plurality of commissures. The valve is coupled to the valve fixation device such that the plurality of commissures are radially aligned with respective struts of the plurality of struts.

Description:
BACKGROUND 
     Of all valvular heart lesions, aortic stenosis carries the worst prognosis. Within one year of diagnosis, half of patients with critical aortic stenosis have died, and by three years this figure rises to 80%. Currently, there is only one effective treatment for patients with aortic stenosis-aortic valve replacement via open heart surgery. Unfortunately, this is a substantial and invasive undertaking for the patient. 
     While there have been significant advances in heart valve technology over the last thirty years, there has been little progress in the development of safer and less invasive valve delivery systems. Aortic valve replacement currently requires a sternotomy or thoracotomy, use of cardiopulmonary bypass to arrest the heart and lungs, and a large incision on the aorta. The native valve is resected through this incision and a prosthetic valve is sutured to the inner surface of the aorta with a multitude of sutures passing into the wall of the aorta. This procedure is accompanied by a 5% mortality rate, in addition to significant morbidity (stroke, bleeding, myocardial infarction, respiratory insufficiency, wound infection) related to the use of cardiopulmonary bypass and the approach to the aortic valve. Elderly patients and those who require concomitant coronary artery bypass grafting experience increased morbidity and mortality. All patients require 4 to 6 weeks to recover from the procedure. 
     Less invasive approaches to aortic valve surgery have followed two paths. In the Eighties, there was a flurry of interest in percutaneous balloon valvotomy. In this procedure, a cardiologist introduced catheters through the femoral artery to dilate the patient&#39;s aortic valve, thereby relieving the stenosis. Using the technology available at that time, success was limited. The valve area was increased only minimally, and nearly all patients had restenosis within one year. More recently, surgeons have approached the aortic valve via smaller chest wall incisions. These approaches still require cardiopulmonary bypass and cardiac arrest, which entail significant morbidity and a prolonged postoperative recovery. 
     A truly minimally invasive approach to the treatment of aortic valve disease requires aortic valve replacement without cardiopulmonary bypass. Such an approach would reduce patient morbidity and mortality and hasten recovery. Although there has been great progress in the treatment of coronary artery disease without cardiopulmonary bypass (angioplasty/stenting and “off-pump” coronary artery bypass grafting), similar advances have not yet been realized in heart valve surgery. With an aging population and improved access to advanced diagnostic testing, the incidence of aortic stenosis will continue to increase. The development of a system for “off-pump” aortic valve replacement would be of tremendous benefit to this increasing patient population. 
     There are three significant challenges to replacing a diseased aortic valve without cardiopulmonary bypass. The first is to remove the valve without causing stroke or other ischemic events that might result from particulate material liberated while manipulating the valve. The second is to prevent cardiac failure during removal of the valve. The aortic valve serves an important function even when diseased. When the valve becomes acutely and severely incompetent during removal, the patient develops heart failure leading to death unless the function of the valve is taken over by another means. The third challenge is placing a prosthetic valve into the vascular system and affixing it to the wall of the aorta. 
     Temporary valves have been reported in the art, most notably by Boretos, et. al. in U.S. Pat. No. 4,056,854 and Moulopoulos in U.S. Pat. No. 3,671,979. All temporary valves disclosed to date have been inserted into a vessel, advanced to a location distant from the insertion site and then expanded radially from the center of the vessel. 
     These designs have many disadvantages. First, they tend to occupy a significant length of the vessel when deployed. During a valve procedure, it may be advantageous to place the temporary valve in a vessel between two branches leading from that vessel. It may also be necessary to insert other tools through the vessel wall between those two branches. A temporary valve such as the ones disclosed in the art may leave very little room between the branches for insertion of these tools. The valves disclosed to date tend also to be rather flimsy and may have difficulty supporting the fluid pressures while the valve is closed. A more significant disadvantage of these valves is that they generally must be inserted into a vessel at a significant distance from the valve to allow adequate room for deployment. If some portions of the operation are performed through the chest wall, insertion of such a temporary valve may require a separate incision distant from the chest cavity. This adds morbidity and complexity to the procedure. Another drawback of the prior art is that valves with three or fewer leaflets rely on the perfect performance of each of those leaflets. If one of the leaflets malfunctions, the valve fails to function adequately. 
     Throughout this disclosure the terms proximal and distal will be used to describe locations within the vascular anatomy. In the arterial system, proximal means toward the heart while distal means away from the heart. In the venous system, proximal means away from the heart while distal means toward the heart. In both the arterial and venous systems a distal point in a blood flowpath is downstream from a proximal point. The terms antegrade and retrograde flow are also used. In the arterial system, antegrade refers to flow away from the heart while retrograde refers to flow toward the heart. In the venous system, these terms are again reversed. Antegrade means toward the heart while retrograde means away from the heart. 
     SUMMARY OF THE INVENTION 
     The present invention relates to devices and methods for providing a valve within a fluid-bearing vessel within the body of a human. The present invention further relates to intravascular filters capable of filtering particulate debris flowing within a vessel. The present invention further relates to devices and methods for performing the repair or replacement of cardiac valves. 
     One aspect of the present invention involves methods and devices of performing aortic valve repair or replacement. In one form, the method involves the steps of inserting at least a temporary valve and a temporary filter into a segment of the aorta. Following placement of these devices, various procedures can be carried out on the aortic valve. Following the procedure, the temporary valve and temporarily filter can be removed. 
     The temporary valve acts to restrict retrograde blood flow while allowing antegrade flow. Generally, the valve allows forward or antegrade flow during the systolic phase of cardiac rhythm while obstructing flow during the diastolic phase. The valve serves to assist or replace the function of the native aortic valve while a procedure is performed on the native valve. The temporary valve means can be one of a variety of possible designs. The embodiments described below are merely illustrative examples and do not serve to limit the scope of this invention. 
     The temporary valve can be placed in any suitable location within the aorta and can be inserted either directly into the aorta itself or advanced into the aorta from a peripheral vessel such as the femoral or axillary artery. The temporary valve is preferably inserted into the vascular system in a compressed state requiring a relatively small insertion hole and expands or is expanded within the aorta at a desired site. It can then be compressed for removal. In its expanded state, the valve can occupy the entirety of the aorta&#39;s flow path, although this is not a requirement of the present invention and may not be preferred in certain patients with extensive atherosclerotic disease in the aorta. The temporary valve, therefore, can, but does not need to contact the wall of the aorta and can act to obstruct all or only a portion of the aorta&#39;s flow path. 
     The temporary filter acts to prevent emboli that may be dislodged during the valve procedure from moving distal to the filter. In a preferred method of use, the filter is placed in the aorta proximal to the braciolcephalic artery to prevent emboli from reaching the brain. The filter can be one of a variety of designs, including, but not limited to a mesh filter with a pore size smaller than the dimensions of anticipated embolic particles. The filter can be inserted directly into the aorta or advanced into the aorta from a peripheral artery. It is preferably inserted in a compressed state and expands or is expanded to a larger state at a desired site within the aorta. 
     The temporary filter and temporary valve can be separate elements or part of a single device. They may be affixed to various tubes, rods, wires, catheters, etc., to aid in their insertion into and removal from the vascular system. 
     Once the temporary valve and filter have been placed within the aorta, various procedures can be performed safely on the aortic valve while the heart is beating. This includes, but is not limited to, balloon aortic valvuloplasty, or removal of the aortic valve, followed by placement of a permanent valve prosthesis. The temporary valve, temporary filter, or both may be designed with lumens through which various procedure instruments can be placed. Instruments might also be passed around these devices or through a site in the aorta proximal to them. 
     Another aspect of the present invention is a method of performing a procedure on a beating heart involving, at a minimum, inserting into the aorta, a temporary valve, as described above, removing at least some portion of the native aortic valve, and placing a permanent valve prosthesis at a site within the aorta. The temporary valve allows removal of the native valve while reducing the risk of heart failure due to insufficiency of the native valve. Removal of at least some portion of the native valve can be carried out with one or a variety of tools that can be inserted either directly into the aorta or through a peripheral artery and advanced to the native valve. Similarly, the permanent valve prosthesis can be inserted either directly into the aorta or advanced into the aorta from a peripheral artery. The valve prosthesis is preferably inserted in a compressed state and expands or is expanded at the desired implantation site. The implantation site is preferably proximal to the coronary arteries, but can be at any suitable location in the aorta. The valve can be one of a variety of types known in the art, but is preferably a flexible valve suitable for inserting into an artery in a compressed state. This method can further involve the placement of a temporary filter as described above to reduce the risk of emboli generated during manipulation of the native valve. As described above, the temporary filter can be a separate device or an integral component of the temporary valve. 
     Any procedure performed using the disclosed methods can be assisted by one of a variety of visualization technologies, including, but not limited to, fluoroscopy, angioscopy and/or epi-cardial, epi-aortic, and/or trans-esophageal echocardiography. These methodologies allow real-time visualization of intra-aortic and intra-cardiac structures and instruments. 
     Specific reference is made to procedures performed on the aortic valve in this description, however the methods and devices described herein could be applied to other valves within the heart. The devices described above and in the claims below can be used as part of procedures performed on cardiac valves, but their use is not restricted to this limited application. 
    
    
     
       DESCRIPTION OF THE DRAWING 
       For a fuller understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which: 
         FIGS. 1A-1F  depict various phases in the deployment of an exemplary filter device of the present invention; 
         FIGS. 2A-2C  depict another embodiment of a temporary filter device. A small balloon located about the exterior of the cannula of this device forces blood to flow through a filter when inflated; 
         FIG. 3A  shows a schematic representation of an endovascular procedure catheter of the invention, with the one-way valve and filter membrane in a retracted position; 
         FIG. 3B  depicts the endovascular procedure catheter of  FIG. 3A  following deployment of the one-way valve and filter membrane; 
         FIG. 4A  depicts valve and filter components of the procedure catheter of  FIG. 3A  viewed along the retrograde flow path. The valve is closed on the left portion of  FIG. 4A , preventing retrograde flow, and open on the right portion of  FIG. 4A , allowing antegrade flow; 
         FIG. 4B  depicts the “valve open” (left portion) and “valve closed” (right portion) positions of the procedure catheter of  FIG. 3A  viewed along an axis perpendicular to the flow path; 
         FIG. 5A  depicts the filter membrane element of the procedure catheter of  FIG. 1A  as viewed along the flow path within a vessel; 
         FIG. 5B  depicts the procedure catheter of  FIG. 3A  with the one-way valve removed; 
         FIG. 6  depicts an exemplary deployment system for the temporary valve and filter elements of the endovascular procedure catheter of  FIG. 3A ; 
         FIGS. 7A-7D  depict exemplary elements used to aid in deployment of the temporary valve and filter element of the endovascular procedure catheter of  FIG. 3A ; 
         FIGS. 8A and 8B  depict another embodiment of a temporary valve and filter device of the invention. The temporary valve of the depicted device is a small balloon on the outside of an inner cannula. The balloon is inflated to prevent retrograde flow and deflated to allow antegrade flow; 
         FIGS. 9A and 9B  depict another embodiment of a temporary valve and filter device in accordance with the invention. Flaps of material collapse against the expandable mesh of the temporary filter to prevent retrograde flow; 
         FIGS. 10A and 10B  depict another embodiment of a temporary valve and filter device in accordance with the invention. Slits cut in a valve material located about the expandable mesh provide a path for blood during antegrade flow and close against the expandable mesh during retrograde flow; 
         FIGS. 11A and 11B  depict the device of  FIGS. 2A-C  with the addition of a one-way valve; 
         FIG. 12  depicts an exploded cross-sectional view of an alternative temporary valve assembly in accordance with the invention. In  FIG. 12 , components of the valve pieces are shown in cross section except for backing element  110  and valve  111 ; 
         FIGS. 13A ,  13 B,  13 C,  13 C′,  13 D and  13 D′. depict a series of cross-sectional views of the valve assembly illustrated in  FIG. 12 ; 
         FIG. 13A  depicts the valve of the exemplary valve assembly of  FIG. 12  in a compressed state within a delivery cannula  105 ; 
         FIG. 13B  depicts the valve of  FIG. 13A  advanced outside of delivery cannula  105 ; 
         FIG. 13C  depicts the expanded valve of  FIG. 13A  seen looking down the long axis of the vessel into which it is deployed. The valve is expanded by pulling back on button  101 . In  FIG. 13C , the valve is open, allowing flow through flexible loop  109 . This depiction represents the state of the valve during the systolic phase when placed in the aorta and acting to support the aortic valve; 
       FIG.  13 C′ is the same as  FIG. 13C  with the valve assembly viewed along a radius/diameter of the vessel into which it is deployed. Valve leaflets  111  extend away to the right (as shown) of flexible loop  109 ; 
         FIG. 13D  depicts the expanded valve of  FIG. 13A  seen looking down the long axis of the vessel into which it is deployed. In  FIG. 13D , the valve is in a closed position, preventing flow through flexible loop  109 . This depiction represents the state of the valve during the diastolic phase when placed in the aorta and acting to support the aortic valve; 
       FIG.  13 D′ is the same as  FIG. 13D  with the valve assembly viewed along a radius/diameter of the vessel into which it is deployed. Valve leaflets  111  are collapsed against backing  110 ; 
         FIGS. 14A-14D  depict the valve end of temporary valve assembly of  FIG. 12  inserted into a vessel.  FIG. 14A  is a lateral view, showing partial deployment into the vessel.  FIG. 14B  is a lateral view of the deployment of  FIG. 14A , showing a rod  106  positioning the temporary valve into the vessel. In this view, the temporary valve is beginning to unfold and expand.  FIGS. 14C and 14D  show similar views with the temporary valve somewhat more deployed; 
         FIG. 15  depicts a temporary valve of the invention deployed in the aorta with the valve open; 
         FIG. 16  depicts the temporary valve of  FIG. 16  deployed in the aorta, with the valve closed; 
         FIGS. 17A-17E  show various components of a prosthetic valve and fixation system in lateral views (left side) and axial views (right side); 
         FIG. 18  depicts a method of performing surgery on a cardiac valve using a temporary valve and filter of the invention; 
         FIG. 19  depicts another method of performing surgery on a cardiac valve using a temporary valve of the invention; 
         FIG. 20  depicts the methods of  FIGS. 18 and 19  following removal of the cardiac valve and inner cannula; 
         FIG. 21  depicts deployment of an expandable prosthetic valve through the outer cannula and into the valve annulus, in accordance with the invention; 
         FIG. 22  depicts an exemplary method of fixing a prosthetic valve to a vessel wall during cardiac rhythm, in accordance with the invention; 
         FIGS. 23A and 23B  depict a method for repairing a stenotic aortic valve, in accordance with the invention; 
         FIG. 24  depicts another method for performing surgery in a cardiac valve using a temporary valve and filter in accordance with the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The methods and devices of the present invention can be used for performing procedures on cardiac valves without cardiac arrest or cardiopulmonary bypass. Various embodiments of the methods and devices are described to clarify the breadth of the present invention. 
     Preferred Embodiments—Temporary Filter Device 
     One critical aspect of any intravascular procedure that potentially involves the liberation of embolic material is the prevention of stroke and other ischemic events. Below, numerous temporary filter devices are described that allow the passage of procedure instruments into the vascular system while filtering blood passing through the lumen of the vessel into which the instrument is placed. 
       FIGS. 1A-1F  depict multiple stages of deployment of an exemplary temporary filter device  10  of the present invention. This device is particularly useful during the manipulation and/or resection of a cardiac valve. 
       FIG. 1A  shows the three primary components of the filter device  10 —outer cannula  1 , inner cannula  2 , and expandable mesh  3 . Outer cannula  1  has an inner diameter that is greater than the outer diameter of inner cannula  2 . Mesh  3  is generally tubular when collapsed and at least conical in part when expanded, and is located on the outside of inner cannula  2 . The apex of the conical portion of mesh  3  is movably attached to inner cannula  2  along a length proximal (to the right) of inner cannula  2 &#39;s distal tip. Collapsed mesh  3  is restrained on inner cannula  2  between two OD steps  4  rigidly affixed or integral to inner cannula  2 . These OD steps may be greater than the generalized outer diameter of inner cannula  2  or may mark the ends of a reduced diameter section of inner cannula  2 . The apex of mesh  3  is free to slide along and rotate about inner cannula  2 &#39;s length between the two OD steps. Expandable mesh  3  may be affixed to a ring (not shown) with an inner diameter larger than the outer diameter of cannula  2  a long this length. This allows the cannula to be moved along and rotated about its long axis within a tubular vessel without the expandable means and filter material moving against and abrading the vessel wall. This feature may act to minimize the risk of dislodging embolic material from the vessel wall during manipulations required by the procedure. 
     To maintain its collapsed state in the embodiment of  FIGS. 1A-1F , the self-expanding, mesh  3  is positioned against the outer surface of inner cannula  1 . As shown in  FIG. 1E  (but not shown in  FIGS. 1A-1F ), a filter material  71 , such as woven nylon mesh with a defined pore size, may be positioned over the mesh  3 . Such a material is optional and may be used to cover at least some portion of expanded mesh  3  and may be placed on either the outer or inner surface of mesh  3 . 
     The outer and inner cannulae can be constructed from any one of a variety of materials, including, but not limited to, various plastics, rubber, and metals. They can be either wholly rigid or flexible in nature. They can be rigid along most of their lengths with a small flexible region or regions that allow the cannulae to bend. There can further be a valve means (not shown) situated along the interior of inner cannula  2  that prevents the flow of blood while allowing passage of instruments through inner cannula  2 . Either or both of inner cannula  2  and outer cannula  1  can have additional degassing ports (not shown) exterior to the vascular system to allow removal of air and other gases from the interiors of the cannulae. 
     Expandable mesh  3  can also be made from any one of a variety of materials, but is preferably constructed from elastic metal woven into a tube. This tube preferably has a first diameter in an expanded state and a second, smaller diameter in a compressed state. The first diameter is preferably similar to that of the aorta or vessel in which the filter is used. The mesh itself can act as a filter or filter material can be attached along its interior or exterior. This embodiment is merely an illustrative example. There are many other potential embodiments of a filter means that could be imagined without departing from the spirit of the present invention. 
       FIG. 1B  depicts assembled filter device  10 , with the distal end of the inner cannula  2  inserted into the proximal end of the outer cannula  1 . 
       FIG. 1C  depicts assembled filter device  10  with the outer cannula  1  retracted proximally, exposing mesh  3  and allowing its free to expand against the inner wall of the vessel into which it is deployed. In this embodiment, mesh  3  expands into a conical shape, with the base of the cone extending toward the distal end of the cannulae. Inner cannula  2  has a deflected tip that bends the lumen of the cannula away from the long axis of the device. This bend assists in guiding any procedural instrument passed through the lumen of inner cannula  2  toward the wall of the vessel and/or the attachments of a cardiac valve to that wall. The mobility of mesh  3  in this figure permits this bend without altering the orientation of mesh  3  relative to the vessel into which it is inserted. As shown, the tip of inner cannula  2  extends beyond mesh  3 . Moreover, in some embodiments, that tip is steerable under the remote control of a surgeon. In that configuration, a device, such as valve resecting device which extends out of cannula  2 , may be steered to resect desired portion of a stenotic valve, for example. The invention may also include a fiber optic viewing assembly extending through cannula  2 . 
       FIG. 1D  depicts the device of  FIG. 1C  with inner cannula  2  rotated 180° about its long axis and retracted proximally. The sliding attachment of expanded mesh  3  to inner cannula  2  allows this to occur without any motion of mesh  3  relative to the vessel wall. 
       FIG. 1E  depicts the device of  FIG. 1D  during removal. Outer cannula  1  is advanced over inner cannula  2  and is about to compress expanded mesh  3  and any entrapped material. The mobility of expanded mesh  3  relative to inner cannula  2  causes mesh  3  to move beyond the distal end of inner cannula  2 . This ensures that embolic material captured by mesh  3  will not be trapped between mesh  3  and the exterior of inner cannula  2 . This would prevent passage of outer cannula  1  over mesh  3  and inner cannula  2 . With the mobility of mesh  3  relative to inner cannula  2 , a much greater amount of embolic material may be trapped compared to a fixed proximal filter as described in the prior art. 
       FIG. 1F  depicts the device of  FIG. 1D  with filter material  71  added to the exterior surface of expanded mesh  3 . In this embodiment, expanded mesh  3  has been shortened to just the cone portion of the prior meshes. Extending distally beyond this cone are filter extensions  70  that occupy only a portion of the circumference of a cylinder having a diameter equal to the maximum diameter of the cone-shaped mesh  3 . The extensions are adapted to lie along the vessel wall and rest over the ostium of one or more arteries that branch from the vessel. The extension configuration of  FIG. 1E  is advantageous for filtering the ostia of branch vessels that may be located between valve commissures, such as the coronary ostia in the aorta. 
     For aortic valve applications, extensions  70  are preferably from three points spaced around the circumference of the cone&#39;s expanded end. These points are preferably 120 degrees apart. Each extension  70  is preferably a hemi-circular leaflet with the diameter of the hemi-circle being located about the circumference of the cone&#39;s base. When deployed, device  10  is oriented so that the base of the cone is expanded toward the aortic valve. The shape of the three leaflets allows the filter to be expanded or advanced along the wall of the aorta beyond the plane created by the three apices of the aortic valve commissures. In this position, the leaflets cover and filter the left and right coronary ostia while the filter cone filters blood flowing through the aorta. 
     In the expanded position, the three extensions  70  can be biased against the wall of the aorta by expandable mesh  3 , by the stiffness of the filter material  71 , or by the shape of the filter itself. Extensions  70  can further be designed to exploit pressure within the vessel to compress them against the vessel wall. 
     Such an expandable filter acts to filter just the branch vessels with the conical portion of the expanded mesh left uncovered by filter material  71 . In such an embodiment, either the partial filter extensions can be employed (as in  FIG. 1F ) or full cylindrical filters (not shown) that cover the entire circumference of the vessel wall can be employed. 
       FIGS. 2A ,  2 B, and  2 C show an alternate embodiment of a filter that can be used to filter emboli from blood flowing through a vessel. Filter  20  consists of cannula  17 , a valve located within the interior of the cannula (not shown), an expandable means depicted as balloon  19 , and a filter depicted as mesh  18 . The valve interior to cannula  17  acts to prevent the flow of blood out of the vessel through cannula  17  while allowing the passage of instruments through the lumen of cannula  17 . This valve is positioned to the right of filter  18  as viewed in  FIGS. 2A and 2B . Balloon  19  can be expanded by the injection of gas or liquid through port  21 . Once inflated, balloon  19  obstructs the flow path of the vessel exterior to cannula  17 . Hence, the blood must flow into the interior of cannula  17  and exit the cannula through filter  18 . In this way, emboli are prevented from flowing past the filter. In  FIG. 2B , an intravascular instrument  5  has been passed through the inner lumen of cannula  17 . As instrument  5  does not occupy the entire interior flow area of cannula  17 , blood can flow around instrument  5 , into cannula  17  and through filter  18 .  FIG. 2C  is an end-on view of filter  20  and instrument  5  from the left side as viewed in  FIG. 2B . In this figure, the blood flow path is annulus  22  formed by the inner wall of the cannula  17  and the shaft of the instrument  5 . Additional blood flow paths could be provided through portions of balloon  19 . Optionally, these paths additionally have a filter mesh covering the path. Filter  20  can be used in a variety of intravascular procedures that would benefit from the filtration of blood. 
     Preferred Embodiment—Combined Temporary Valve Devices 
     In order to carry out procedures on cardiac valves without cardiopulmonary bypass, it is critical to support the function of the valve during the procedure. Numerous preferred embodiments of temporary valves that perform this function are disclosed below. Many of these valves are combined with filters to further limit the risk of ischemic events that might result from liberated embolic material. 
       FIGS. 3-7  depict one embodiment of such a combined valve and filter device. As depicted in  FIGS. 3A and 3B , endovascular procedure catheter  2 ′ is inserted into the host. It is positioned over a guide wire  800  at its desired location, for this example in the ascending aorta above the coronary arteries and below the brachiocephalic artery. Guide wire  800  and guiding catheter  700  can then be removed. 
     Once endovascular procedure catheter  2 ′ is in position, temporary one way valve  26 , the selectively permeable, filtering membrane  3 ′, and mounting ring  900  are deployed. Deployment comprises the controlled, adjustable increase in the diameter of valve  26 , membrane  3 ′, and/or mounting ring  900  until they abut or nearly abut the inner wall of the vessel. 
     Temporary one-way valve mechanism  26  can be comprised of any type of one way valve. The critical function of valve  26  is to limit the aortic insufficiency and, thus, the amount of volume overload on the heart generated by resecting or manipulating the diseased or damaged host valve. This will allow procedures to be performed on the valve and replacement of the valve without the need for partial or complete cardiac bypass or cardiopulmonary bypass. 
     Next, the host aortic valve is resected, removed or manipulated. If the valve is to be replaced, the new cardiac valve is implanted. This valve can be mounted on endovascular procedure catheter  2 ′ or can be delivered through another port of entry or cannula. Upon completion of the procedure, all devices are retracted and removed. 
     The illustrated exemplary endovascular procedure catheter  2 ′ is a cylindrical sleeve that is made of a flexible material. It is durable and resistant to thrombogenesis. 
     It has several associated components:
         a lumen for the passage of devices e.g. imaging devices, tissue resecting devices, valve deployment devices, the new valve, or any other device necessary to perform endovascular procedures on the endovascular vessels or valves   a guiding catheter  700  which is tapered on the end and extends out of the working port of the endovascular procedure catheter  2 ′; catheter  700  helps in positioning the endovascular procedure catheter   a one way valve  25  inside the catheter which limits blood loss during the procedure   temporary one way valve  26     a selectively permeable, filtering membrane  3 ′   an endovascular mounting ring  900  onto which temporary valve  26  and/or selectively permeable, filtering membrane  3 ′ are mounted   a stent system  950 - 958  which deploys the mounting ring  900 , temporary endovascular one-way valve  26 , and selectively permeable filtering membrane  3 ′ by interacting with guiding catheter  700  and endovascular procedure catheter  2 ′   several holes  600  in the wall of the distal end of the catheter which may augment antegrade flow of blood during the procedure.       

     The aforementioned components may be used alone or in combination during endovascular procedures. 
     The lumen of endovascular procedure catheter  2 ′ functions as a working port allowing for the passage of devices such as imaging devices, tissue resecting devices, or any other device necessary to perform endovascular procedures on the endovascular vessels or valves. 
     Endovascular procedure catheter  2 ′ itself has a one-way valve  25  in its lumen (indicated in phantom) to minimize the loss of fluid i.e. blood during the procedure. This one-way valve can be of any configuration as long as it serves to permit the passage and removal of instruments through the lumen of the endovascular procedure catheter and inhibits retrograde blood flow through the endovascular procedure catheter. It is located proximal to side holes  600  of endovascular procedure catheter  2 ′. 
     Temporary valve  26  is made of a flexible, durable, non-thrombogenic material. Valve  26  can be any type of one-way valve and consist of as many or few leaflets as desired as long as it permits the antegrade flow of blood and prevents the retrograde flow of blood. This minimizes the development of aortic insufficiency created during manipulation of the valve and minimizes the need for cardiac or cardiopulmonary bypass. Valve  26  depicted in  FIGS. 3A ,  3 B and  FIGS. 4A ,  4 B is a bileaflet valve mounted on mounting ring  900 . It permits antegrade blood flow through filter  3 ′ in the open position and inhibits retrograde blood flow by collapsing against filter  3 ′ in the closed position. The valve mechanism is a simple one way, single orifice valve which is mounted on the stabilizer. However, the valve can sit independent of mounting ring  900  and as aforementioned can take on any shape as long as it functions as a one way valve. 
     The center of selectively permeable filtering membrane  3 ′ is mounted on the outside wall of endovascular&#39; procedure catheter  2 ′. The relatively large diameter peripheral edge is mounted on mounting ring  900 . It is conical in shape when deployed and sits just upstream of temporary valve  26 . Filter membrane  3 ′ is made of a flexible, durable, non-thrombogenic material that has pores that are sized to permit select fluids through (i.e. blood and blood components) but prevents the flow or embolization of debris generated during the endovascular procedure. By placing it upstream of temporary valve  26  it prevents prolapse of the temporary valve leaflets. 
     In order to assist in positioning and removal of endovascular procedure catheter  2 ′, a tapered guiding catheter  700  of the size of the internal diameter of endovascular procedure catheter  2 ′ is placed inside endovascular procedure catheter  2 ′ as depicted in  FIG. 3A . In a preferred form, the tapered end at the distal tip DT extends approximately 2 centimeters beyond the distal end of endovascular procedure catheter  2 ′, but other extension lengths may be used. Guiding catheter  700  is made of flexible material and the end is soft to prevent injury to the vessels during placement of endovascular procedure catheter  2 ′. Guiding catheter  700  has a lumen of such a size as to permit its passage over guide wire  800 . 
     Guiding catheter  700  also serves to deploy and retract mounting ring  900 , temporary valve  26 , and filter membrane  3 ′.  FIG. 6  illustrates an exemplary deployment assembly DA for membrane  3 ′. That assembly DA includes elements  950 - 958 , described in detail below. As depicted in  FIG. 7A , guiding catheter  700  has slots distally which engage extension arms  955  of struts  952  that support mounting ring  900 . 
     Mounting ring  900  is mounted on the outside of endovascular procedure catheter  2 ′ by struts  952 . Mounting ring  900  is comprised of a flexible, durable, nonthrombogenic material which abuts the inner lumen of the vessel when deployed. Temporary valve  26  and/or selectively permeable membrane  3 ′ are mounted on mounting ring  900 . When mounting ring  900  is deployed so are the mounted components. Mounting ring  900  is deployed in a controlled, adjustable way. Struts  952  are connected to mobile ring  953  and fixed ring  950  which is mounted on endovascular, procedure catheter  2 ′ as shown in  FIG. 6 . Mobile ring  953  has extensions  955  which extend into the lumen of endovascular procedure catheter  2 ′ by passing through slots in the wall of endovascular procedure catheter  2 ′. These extensions are engaged by grooves  957  in the wall of guiding catheter  700 . Thus as guiding catheter  700  is withdrawn or advanced inside endovascular procedure catheter  2 ′, mounting ring  900  is deployed or retracted in an umbrella-like manner. Once mounting ring  900  is deployed to the desired diameter, it is “locked” into place by engaging extension arms  955  into locking slots  958  cut into the wall of endovascular procedure catheter  2 ′. At this point, guiding catheter  700  is disengaged from extension arms  955  and removed while mounting ring  900  remains deployed. 
     As shown in  FIG. 6 , the strut mechanism consists of struts  952 , rings  950  and  953 , and hinges  954 . The strut mechanism depicted here consists of three struts  952  that connect mounting ring  900  to the fixed proximal ring  950  that is mounted on the outside of procedure catheter  2 ′. These struts are also connected to support arms  951  which extend to mobile distal ring  953  also mounted to the outside of endovascular procedure catheter  2 ′. Distal ring  953  has extension arms  955  which extend through the slots in the wall of procedure catheter  2 ′ as shown in  FIG. 7 . Mounting ring  900  is expanded by moving support rings  953  and  950  relative to each other. Struts  952  and arms  951  are hinged at pivot points  954 . 
       FIGS. 8A and 88  illustrate another embodiment of a combined valve and filter device for use in intravascular procedures. The filter means of device  40  is the same as device  10  depicted in  FIGS. 1A-1E . A temporary valve, depicted in  FIGS. 8A and 88  as expandable balloon  25 , is situated on the exterior of outer cannula  1 ′ of the device. A continuous lumen (not shown) extends from the interior of balloon  25  to port  21 ′. Port  21 ′ is connected to balloon pump  8  by tube  24 .  FIG. 8A  depicts a device  40  with filter  3  deployed and balloon  25  deflated during the systolic phase of the cardiac rhythm.  FIG. 8B  shows balloon  25  in an inflated state  25 ′ during the diastolic phase. Similar to device  10  of  FIG. 3 , inner cannula  2  may have a lumen through which instruments can be passed to effect an intravascular procedure. In these figures, the filter is shown to the left of the valve. In other embodiments, this relationship may be reversed. 
       FIGS. 9A and 9B  show yet another embodiment of a combined valve and filter device for use in intravascular procedures. Device  50  is the same as device  10  in  FIGS. 1A-1E  with the addition of valve means  26  that covers the surface of expanded filter  3 . In this embodiment, valve means  26  consists of one or a number of thin sheets of material that are attached to the exterior of the base of the cone formed by the expanded mesh filter  3 . The sheet material is relatively free to move at the apex of the cone such that mesh filter  3  and the sheet material act in concert as a flap valve. As shown in  FIG. 9B , blood flows through filter  3  from the interior of the cone causing flap valve  26  to open and allow flow. As shown in  FIG. 9A , blood moving toward the exterior of the cone causes the sheet material of flap valve  26  to move against the exterior of the cone, preventing flow through filter  3 . The device can be delivered with mesh filter  3  and flap valve  26  in a compressed state within outer cannula  1  similar to  FIG. 3B . Mesh filter  3  and valve  26  then expand once outer cannula  1  is retracted. The sheet material can additionally be affixed to a more proximal segment of inner cannula  2  by thin filaments  27  or the like to aid in returning valve  26  and filter  3  to a collapsed state by advancing the outer cannula  1 . 
       FIGS. 10A and 10B  show another embodiment of a combined valve and filter device. Device  60  is the same as device  10  in  FIGS. 1A-1E  with the addition of valve  28  that covers the surface of expanded filter  3 . Valve  28  consists of a singular sheet of material that covers the entirety of the outer surface of the cone portion of expanded mesh filter  3 . It is attached, at a minimum, to the cone&#39;s base and either its apex or the exterior of inner cannula  2  near the apex. Slit  29  is cut through the sheet between these attachment sites. As shown in  FIG. 10A , slot  29  closes against filter  3 ′ during retrograde flow, i.e. flow from the cone&#39;s apex toward its base, preventing the passage of blood through expanded filter  3 . As shown in  FIG. 10B , slit  29  moves to an open state  29 ′ during antegrade flow, i.e. from the cone&#39;s base toward its apex, allowing passage of blood through expanded filter  3 . Slit  29  is shown in these figures as being in a plane that passes through the long axis of inner cannula  2 , however other orientations are possible. A singular slit is shown, although there could be multiple slits. The sheet material comprising valve  28  can be attached at additional sites along mesh filter  3  to assist in its function. 
       FIGS. 11A and 11B  depict a combined valve and filter device  30 . The filter means of device  30  is the same as filter device  20  shown in  FIGS. 2A-2C . In this embodiment, valve  22  is placed around the exterior of cannula  17 , covering filter  18 . Valve means  22  is preferably a flexible sleeve of material such as silicone rubber. A slit  23  has been cut through the sleeve along its length. Slit  23  is normally closed, but opens under positive pressure within cannula  17 . Hence, when this device is placed in the arterial system with the distal end (near balloon  19 ) pointed proximally, slit  23  opens during the systolic phase of cardiac rhythm, allowing blood flow through filter  18 , and closes during the diastolic phase, preventing blood flow through filter  18 .  FIG. 11A  depicts valve  22  in a closed position.  FIG. 11B  depicts valve means  22  in an open position. Similar to device  20 , device  30  may be configured with additional flow paths (not shown) passing through balloon  19 . These flow paths may have filters associated with them that act to filter blood passing therethrough. These flow paths may include additional valves that resist retrograde flow while allowing antegrade flow. 
     Each of the preceding filter and valve embodiments are adapted to be inserted into a vessel through an insertion site and expanded radially from the center of the vessel at a site remote from that insertion site. 
       FIGS. 12-14  disclose a temporary valve assembly (with optional filter)  100  which can be inserted substantially perpendicular to the long axis of the vessel and expanded at or near the insertion site. 
     In a preferred form, the valve assembly  100  consists of four components—a cannula, a deformable loop, a backing element and a valve. In use, the distal end of the cannula is inserted into a vessel, the deformable loop is then advanced out of the distal end into the vessel and expanded to abut the interior wall of the vessel. The backing element spans the interior lumen of the expanded loop and is attached to the loop at at least one point. The backing element is permeable to blood flow. A valve is affixed to either the expanded loop, the backing element, or both and functions to stop flow along the long axis of the vessel in a first direction through the loop by collapsing against the backing element and covering substantially all of the lumen formed by the loop. The valve further allows flow in a second, opposite direction by deflecting away from the backing element during flow through the loop in that direction. 
       FIG. 12  depicts the detailed construction of the valve device  100  in exploded form. Button  101  is a rigid piece with an opening that is used to attach it to a central rod  106 . Rod  106  is rigid and is attachable to the valve components of the device (Parts G, A, and B, as illustrated) as well as two small discs  108  and  108 ′. Secondary button  102  is affixed to valve holder  107  through tube  103 . Parts I form proximal seal  104  and are affixed to each other and delivery cannula  105 . Tube  103  can slide through the lumens of proximal seal  104  and delivery cannula  105 . Rod  106  can in turn be passed through the lumens of valve holder  107 , tube  103 , and secondary button  102 . Proximal seal  104  includes an o-ring that seals around the exterior of tube  103 . Flexible loop  109  has a hole through the center of its length seen at the base of the loop formed in the figure. A backing element  110  and valve  111  are affixed to flexible loop  109  with any suitable fixation means. Backing element  110  spans the interior of flexible loop  109 . Element  110  is made of flexible material and in its preferred embodiment is a woven nylon sheet. This sheet can act to filter particulate debris from blood passing through flexible loop  109 . Valve  111  is a set of valve leaflets. In this figure there are six valve leaflets. These leaflets are attached to the periphery of backing means  110 , flexible loop  109  or both, for example, by way of a ring of material surrounding the leaflets. Once assembled, backing element  110 , valve  111 , and flexible loop  109  are affixed to valve holder  107  through the two small through-holes in valve holder  107 . These through holes act as hinge points about which the ends of flexible loop  109  can pivot. Rod  106  is inserted through a central lumen in valve holder  107 , superior disc  108 , the hole in flexible loop  109 , and finally inferior disc  108 ′. Discs  108  and  108 ′ are affixed to rod  106  to immobilize the center section of flexible loop  109  relative to the lower end of rod  106 . Valve holder  107  fits within the lumen of delivery cannula  105 . 
     In a preferred embodiment of this valve assembly  100 , backing element  110  is a porous sheet of material that further acts to filter blood passing through deformable loop  109 . This porous sheet can be a woven material with an open area that allows the passage of blood, although other forms may be used, all within the scope of the invention. 
     In another preferred implementation of the device  100 , deformable loop  109  is made from a strip of material with a non-circular cross section. It may have a rectangular cross-section. The thicker side of the rectangle can be positioned against the wall of the vessel. This gives the loop greater flexibility to conform easily to the shape of the wall and greater stiffness against flopping or twisting away from the vessel wall under the pressure of blood flowing through the vessel. 
     The valve  111  is preferably effected by a set of valve leaflets as shown. The valve leaflets can collapse, in an overlapping manner, against backing element  110  to prevent flow in a first direction through the loop  100 . The leaflets may alternatively coapt against each other so as to prevent flow in the first direction. In the latter form, the device may be used without a filter (backing element), to provide a valve-only device. Generally, such a device would be used with a filter in another location. 
     The leaflets of valve  111  are preferably formed from thin, flexible sheets of material. There may be any number of leaflets. The leaflets may be sized to act in concert to close the flow path formed by the loop. The leaflets may alternatively be oversized, such that fewer than all of the leaflets are required to close the flow path. 
     In one embodiment, there may be two or more leaflets with one or some combination of the leaflets capable of closing the flow path through the loop against flow in the second direction. 
     The valve  111  may alternatively be a sheet of material cut with slits. The slits stay substantially closed (not parted) to prevent flow in a first direction through the flow path created by the loop  109  by collapsing against the backing element. The slits allow the passage of blood in the second, opposite direction through the flow path by parting open in the direction away from the backing element. 
     In a preferred method of using a valve of the form of  FIGS. 12-14 , the device is expanded from a point or set of points on the circumference of the vessel into which it is placed until the valve occupies substantially all of the cross sectional flow area of that vessel. 
     Another method of using that device of the form of  FIGS. 12-14 , is to insert the distal end of the device into the vessel through an entry site and expanding the valve proximate to the entry site. This allows the device to be placed easily, near the heart, during an open-chest procedure. 
     Another method of using the device is to insert its distal end into a vessel along a path that is substantially perpendicular to the long axis of the vessel and expand the valve about that path. In a preferred application of this method, the device is expanded until it occupies the entire flow path of the vessel and sits within a cross-section of that vessel taken perpendicular to the vessel&#39;s long axis. This minimizes the length of the vessel taken up by the temporary valve device. 
       FIG. 15  depicts temporary valve assembly  100 , with its valve deployed in aorta  215 . In this figure, a procedure is indicated as being performed on aortic valve  212  through a separate access cannula  201  using procedure instrument  205 . Device  100  is shown with its valve open (as in FIG.  13 C′) allowing flow through flexible loop  109 . This figure depicts the systolic phase of cardiac rhythm. 
     In  FIG. 16 , valve assembly  100  is similarly positioned, but is closed (as in FIG.  13 D′), preventing flow back toward the heart. This figure depicts the diastolic phase of cardiac rhythm. The position of valve assembly  100  distal to the three branches from the aortic arch is shown as a representative application of the device and by no means limits its application to this position. 
     Preferred Embodiment—Prosthetic Valve 
     Another aspect of the present invention is a valve fixation device, illustrated in  FIGS. 17A-17E . The valve fixation device  300  is used to secure a prosthetic valve to the wall of a vessel. In a preferred embodiment, the prosthetic valve is a stentless tissue valve. The tissue valve has a base, located proximal to the heart when placed in an anatomic position, and an apex located distal to the base. The prosthetic valve preferably has three commissures and three leaflets. The apex of the commissures is toward the apex of the valve. The valve has an interior surface and an exterior surface. The interior surface serves as an attachment site for the valve leaflets to the valve anulus. The exterior of the valve is generally smooth and forms at least a portion of a cylinder. The valve has a long axis that runs along the long axis of the cylinder. 
     The valve fixation device consists of at least one substantially rigid strut and at least two expandable fixation rings. The strut(s) runs along the exterior surface of the valve in a direction substantially parallel to the long axis of the valve. The rings are preferably located about the circumference of the base and apex of the valve. These rings are affixed to the strut(s) such that the distance along the long axis of the valve between the rings is fixed. The rings may be located either on the interior or exterior surface of the valve. The valve is preferably affixed to both the rings and the struts by any suitable fixation means including, but not limited to barbs, sutures, staples, adhesives, or the like. In a preferred embodiment, the valve fixation device  90  has three struts  92  and two rings  91 . Each of the three struts  92  is affixed to the valve a long an axis that is parallel to the long axis of the valve and passes proximate to one of the valve commissures. 
     The rings  91  are preferably self-expanding. Alternatively, rings  91  may be plastically expandable by any suitable means, such as a balloon. The rings  91  and/or strut(s)  92  may employ barbs or spikes  83  at any location along their exterior to aid in securing the valve to the vessel wall. The rings  91  may further be affixed to the exterior of the valve and employ a sealing material  84  or other means, on rings  91 , to aid in sealing rings  91  against the vessel wall. 
     In the preferred embodiment, the valve fixation device  90  and attached tissue valve  80  are inserted in a compressed state into the vascular system. The compressed valve/fixation system is then advanced to the site of implantation, expanded, and secured to the vessel wall. When used as an aortic valve replacement, the compressed valve/fixation system can be inserted through any peripheral artery distal to the aorta. Alternatively, the valve can be inserted through the wall of a cardiac chamber or directly into the aorta itself. Various devices can be employed to aid in delivering the valve to the implantation site, including, but not limited to delivery cannulae, catheters, and any of a variety of valve holders known in the art. 
       FIG. 17A  depicts a stentless tissue valve  80  such as those known in the art. The valve consists of valve wall  81  and three attached leaflets  82 . Valve wall  81  has three sections of its cylindrical form removed so as not to block branch vessels such as the coronaries. There are many variations of this type of valve prosthesis. Any flexible valve with a wall and leaflets can be used with the present invention. 
       FIG. 17B  depicts valve fixation device  90  of the present invention. This embodiment comprises two expandable rings-like structures  91 , shown in their expanded state, and three struts  92 . Struts  92  are relatively rigid and do not change dimensions from the compressed to the expanded state of the device  90 . The three struts  92  are separated by roughly 120 degrees in the illustrated form, as shown in the axial view of the figure, corresponding to the three commissures of the prosthetic valve. Struts  92  are preferably relatively rigidly attached to expandable rings  91  such that the two expandable rings  91  may not rotate about their central axes relative to each other. This avoids twisting of tissue valve  80  during deployment, minimizing the risk of valve leakage. 
       FIG. 17C  depicts valve fixation device  90  affixed to tissue valve  80 , forming valve assembly  85 . Fixation device  90  can be affixed to tissue valve  80  at sites along struts  92 , expandable rings  91 , or both. In this embodiment, struts  92  and expandable rings  91  are affixed to the outside of the valve wall  81 . 
       FIG. 17D  depicts the assembly  85  of  FIG. 17C  in a compressed state  85 ′ suitable for insertion into an artery or vein through a relative smaller opening. 
       FIG. 17E  depicts another embodiment of the valve fixation device  90 . In embodiment  86 , barbs  83  reside on the exterior surfaces of both struts  92  and expandable rings  91  to aid in securing the device  90  to a vessel wall. Felt  84  has also been added to the expandable rings  91  to aid in sealing against peri-valvular leaks. Felt  84  could be added to struts  92 . Other forms of sealant may be used as well. 
     Preferred Embodiments—Procedure Methods 
     The above embodiments may be used alone or in combination with other devices to carry out procedures on a cardiac valve while the heart is beating. Below are numerous such procedure methods in accordance with the invention, which are described to clarify the breadth of possible applications of these preferred device embodiments. 
       FIG. 18  depicts a procedure being carried out on aortic valve  412  while the heart is beating. Instrument  405  is manipulating aortic valve  412  following the placement of both temporary valve  406  and filter device  410 . In this embodiment, temporary valve  406  and filter device  401  (for example device  10  of  FIGS. 1A-1F ) are separate instruments that have been inserted directly into the aorta through separate insertion sites  414  and  413 . Alternatively, valve  406  and filter  410  may be effected in a single instrument placed through a single incision. Valve  406  and filter  410  may also be inserted from a peripheral vessel and advanced to a location within the aorta. 
     Mesh filter  403  is deployed through outer cannula  401  to a preferred site proximal to the brachiocephalic artery  411 . In this position, filter  403  prevents distal embolization of debris that may be dislodged during manipulation of valve  412 . Portions of inner and outer cannulae  401  and  402  and instrument  405  extend to the exterior of the aorta where they can be manipulated by a surgeon. In the method illustrated by  FIG. 18 , balloon valve  406  is deployed in the descending aorta  415 . Balloon  406  is inflated and deflated by an attached balloon pump  408  exterior to the patient. Balloon pump  408  is in fluid connection with balloon  406  through tube  407 . Balloon pump  408  is timed to the cardiac rhythm so that it inflates balloon  406  during substantially all of the diastolic phase and deflates balloon  406  during substantially all of the systolic phase. This allows the valve  406  to perform the function of aortic valve  412  while the aortic valve is manipulated. 
       FIGS. 19 ,  20 , and  21  show another form of the present invention. Those figures depict sequential views of method of removing the native aortic valve and replacing it with a permanent prosthetic valve while the heart is beating. In  FIG. 19 , balloon valve  406  has been placed in the descending aorta  415 . Cannula  401  has been placed into the aorta to allow the passage of instrument  405 . Cannula  401  may have a valve (not shown) along its interior that acts to prevent the flow of blood through the cannula while allowing the passage of various instruments. Instrument  405  has been inserted through cannula  401  to remove native aortic valve  412 .  FIG. 20  shows the embodiment described in  FIG. 19  after substantially all of the aortic valve has been removed. Portions  412 ′ of the aortic valve may remain without deviating from the scope of this invention. Indeed resection of native valve  412  can be limited to removal of those portions of the right and left valve leaflets that would cover coronary arteries  409  if the valve were to be compressed against the inner walls of the aorta. Instrument  405  has been withdrawn from outer cannula  401  to allow the insertion of valve prosthesis  416  into the aorta. In this figure, temporary valve  406  is performing the full function of the resected aortic valve.  FIG. 21  shows valve prosthesis  416  expanded against and affixed to the aortic wall at a site near the previous attachment of the native valve. Once valve prosthesis  416  is in place and functioning, temporary valve  406  can be removed. No filter is shown in  FIGS. 19 ,  20 , and  21 . A filter is not necessary for completing the procedure, but could be used without deviating from the intent of the present invention. 
     Another method of replacing a cardiac valve while the heart is beating, employs described using a combination of the methods disclosed in  FIGS. 18 ,  20 , and  21 . In accordance with the latter method, a set of two concentric cannulae, inner cannula  402  that fits within the lumen of outer cannula  401 , are inserted into the vessel. The method further involves the steps of advancing the set of cannulae to a site downstream of the cardiac valve, expanding an expandable member  403  from the exterior of the inner cannula  402 , performing a procedure at least in part through the lumen of the inner cannula that removes or disrupts cardiac valve  412 , retracting inner cannula  402  and expandable member  403  through the inner lumen of outer cannula  401 , leaving the distal end of outer cannula  401  near the annulus of cardiac valve  412 , inserting a compressed valve prosthesis  416  through the inner lumen of outer cannula  401  to the site of the cardiac valve anulus, and expanding and affixing prosthetic valve  416  to the cardiac valve annulus. Using the set of two cannulae allows the insertion and removal of expandable member  403  on the exterior of inner cannula  402  as well as valve prosthesis  416  and other instruments through the lumen of outer cannula  401  without losing the position of outer cannula  401  relative to the cardiac valve during the procedure. Expandable member  403  is located anywhere along the length of inner cannula  402  and performs any number of functions such as acting as a temporary valve, acting as a filter, or removing or disrupting the cardiac valve leaflets. 
       FIG. 22  depicts one method of fixing a prosthetic valve  516  to a vessel wall during cardiac rhythm. In this embodiment, prosthetic valve  516  is inserted into aorta  515  in a compressed state through access cannula  501 . Prosthetic valve  516  is then expanded to abut the inner wall of aorta  515 . A needle  512  and suture  514  are then passed from the outer surface of aorta  515  through the aortic wall and into the prosthetic valve  516 . In this depiction, three sutures are used to tack prosthetic valve  516  to the aortic wall in locations superior to the valve commissures. Alternatively, a fixation means can be passed from the interior wall of aorta  515  through to the exterior surface. The fixation means can be a staple, suture or other suitable means. 
     In accordance with another aspect of the present invention, a compressed prosthetic valve is inserted into a vessel downstream of the cardiac valve to be replaced. The prosthetic valve is then expanded to allow it to function temporarily in its downstream location. With that valve temporarily placed, and functioning, a procedure on the cardiac valve is performed, involving the disruption and/or removal of the cardiac valve. Then the prosthetic valve is advanced toward the site of the excised or disrupted cardiac valve, and affixed at a site within the vessel at or near the site of the excised or disrupted cardiac valve. During the procedure on the cardiac valve, the expanded prosthetic valve functions as the native valve, preventing retrograde flow. 
     The cardiac valve procedure occurring while the prosthetic valve is downstream of its final position, may be performed through an incision somewhere between the cardiac valve and the prosthetic valve. Alternatively, the procedure could be done with tools inserted through the functioning prosthetic. 
       FIGS. 23A and 23B  depict a method for repairing a stenotic aortic valve in accordance with the invention.  FIG. 23A  shows stenotic aortic valve  612  within the aortic root. View  1  in this figure shows two views of stenotic valve  612  looking along the long axis of aorta  615  proximal to the valve. In this view, the leaflets of valve  612  provide a reduced aperture due to the stenosis. 
       FIG. 23B  shows the aortic valve after the repair method of the invention has been implemented. Initially, the aortic valve  612 ″ is disrupted by incising each leaflet such that six leaflets are formed. A balloon valvuloplasty may optionally be performed on valve  612 ″. Following the disruption of valve  612 ″, a valve support  620  is positioned upstream of the valve  612 ″. Preferably, the valve support  620  includes an expandable outer ring (circular or otherwise, eg elliptical, oval, polygonal), which is spanned by a bloodflow permeable structure. The outer ring is expanded to be proximal to and affixed to the aortic wall, so that the support structure provides a surface against which the disrupted leaflets can collapse, forming a multileafed flap valve, similar to the valve described above in conjunction with  FIGS. 12-14 . 
       FIG. 24  depicts a procedure being performed on the aortic valve  412  while the heart is beating. Instrument  405  is manipulating aortic valve  412  following the placement of both temporary valve  100  and filter device  410  (for example, device  10  of  FIG. 1F ). In this embodiment, temporary valve  100  and filter device  410  have been inserted directly into the aorta through separate insertion sites  414  and  413 . 
     Mesh filter (not visible) has been deployed through outer cannula  401  to a site proximal to the coronary arteries  409 . Filter material  71  covers the mesh filter. Filter extensions  70  extend from the filter material and form filter leaflets that prevent embolic material from entering the coronary arteries  409 . Portions of the inner and outer cannulae  401  and  402  and instruments  405  extend to the exterior of the aorta where they can be manipulated by the surgeon. 
     In the method illustrated in  FIG. 24 , temporary valve  100  is deployed in the descending aorta  415 , and as described earlier, expands to occupy the entire flow path. Temporary valve  100  is shown in the systolic phase of cardiac rhythm, i.e. with its valve open (as in FIG.  13 D′), allowing flow through the device. 
     In other embodiments of the invention the temporary valve and/or filter may be deployed downstream of the aortic valve, or in still other forms, downstream of the mitral or other cardiac valves. Further, these devices may be deployed downstream of one cardiac valve while procedures are being performed on another cardiac valve upstream of the devices. 
     Although preferred and other embodiments of the invention are described herein, further embodiments may be perceived by those skilled in the art without departing from the scope of the claims.