Abstract:
The present invention comprises a method for deploying an aortic valve prosthesis. This valve prosthesis may include any of the known aortic valves including, but not limited to, stented and unstented bioprosthetic valves, stented mechanical valves, and expandable or self-expanding valves, whether biological or artificial. The method involves the steps of: making a first opening leading to the left atrium; passing a valve prosthesis through the opening and into a cardiac chamber of the left side of the heart using a first manipulation instrument; making a second opening in the arterial system and advancing one end of a second manipulation instrument through the arterial opening and into the aforementioned cardiac chamber; securing the second manipulation instrument to the valve prosthesis; and using the second manipulation instrument to retract at least some portion of the valve prosthesis out of the aforementioned cardiac chamber.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION  
       [0001]    This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 60/215,245, filed Jun. 30, 2000 for CARDIAC VALVE PROCEDURE METHODS AND DEVICES, which patent application is hereby incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    Of all valvular heart lesions, aortic stenosis carries the worst prognosis. Within one year of diagnosis, approximately half of all patients with critical aortic stenosis have died, and by three years, this figure rises to approximately 80%. Currently, the most prominent and effective treatment for patients with aortic stenosis is aortic valve replacement via open heart surgery. Unfortunately, this procedure is a substantial and invasive undertaking for the patient.  
           [0003]    While there have been significant advances in heart valve technology over the past 30 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 then a prosthetic valve is sutured to the inner surface of the aorta with a multitude of sutures passing only partly into the wall of the aorta. Given the current invasiveness of this procedure and the requirement to utilize cardiopulmonary bypass, aortic valve replacement surgery is associated with a high risk of morbidity and mortality. This is especially true in elderly patients, and in those patients who require concomitant coronary artery bypass grafting. Even when a good surgical result is achieved, virtually all patients require approximately 6 weeks to several months to fully recover from the procedure. In order to decrease these associated risks of aortic valve surgery, many have pursued novel approaches and technologies.  
           [0004]    Less invasive approaches to aortic valve surgery have generally followed two paths.  
           [0005]    In the 1980&#39;s, there was a flurry of interest in percutaneous balloon valvotomy. In this procedure, a cardiologist introduced a catheter 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.  
           [0006]    More recently, surgeons have approached the aortic valve via smaller chest wall incisions. However, these approaches still require cardiopulmonary bypass and cardiac arrest, which themselves entail significant morbidity and a prolonged post-operative recovery.  
           [0007]    The ideal minimally invasive approach to the treatment of aortic valve disease requires aortic valve replacement without cardiopulmonary bypass and without cardiac arrest. Such an approach would greatly reduce patient morbidity and mortality and hasten recovery. Unfortunately, although there has been great progress in the treatment of coronary artery disease without cardiopulmonary bypass (e.g., angioplasty, with or without 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 and accurate diagnosis of aortic stenosis will continue to increase. The development of a system for “off-pump” aortic valve replacement would be of significant benefit to this increasing patient population.  
           [0008]    There are three important challenges to replacing a diseased aortic valve without cardiopulmonary bypass.  
           [0009]    The first challenge is to remove the diseased valve without causing stroke or other ischemic events that might result from the liberation of particulate material while removing the diseased valve.  
           [0010]    The second challenge is to prevent cardiac failure during removal of the diseased valve. In this respect it must be appreciated that the aortic valve continues to serve a critical function even when it is diseased. However, as the diseased valve is removed, it becomes acutely and severely incompetent, causing the patient to develop heart failure which results in death unless the function of the valve is taken over by another means.  
           [0011]    The third challenge is placing a prosthetic valve into the vascular system and affixing it to the wall of the aorta. More particularly, during cardiac rhythm, the aortic and arterial pressures are substantially greater than atmospheric pressure. Therefore, any sizable incision made to the aorta in order to insert a standard valve prosthesis into the arterial system creates the potential for uncontrollable bleeding from the incision site. Furthermore, even if bleeding is successfully controlled, pressures within the aorta may result in weakening of the aorta caused by aortic wall dissection. In addition, large incisions on the aorta also increase the potential for liberating plaque from the aortic wall that can lead to embolic complications.  
           [0012]    For these reasons, prior art valve prostheses potentially suitable for off-pump implantation have relied upon relatively flimsy expandable structures to support and secure the valve within the aorta. More particularly, these prosthetic valves are constructed so that they can be compressed to a relatively small dimension suitable for insertion into the arterial system, advanced to the site of the aortic valve, and then expanded against the aortic wall. Unfortunately, however, none of these relatively flimsy valve prostheses have proven adequate to endure the repetitive stresses undergone by the aortic valve over the ten to twenty years typically required.  
           [0013]    In addition to the foregoing, the precise placement of such expandable prosthetic valves in the correct sub-coronary position can be extremely challenging, particularly in view of the high pressure, pulsatile blood flow passing through the aorta. Furthermore, expandable prosthetic valves would typically be positioned from a remote artery, which would reduce the ability to precisely control the placement and positioning of the device and therefore would increases the risk of obstructing the coronary arteries. The expandable prosthetic valves are held on the ends of elongate, flexible catheters that are threaded into the aorta, around the aortic arch and then expanded. The pulsatile flow during cardiac rhythm induces a to-and-fro motion of the valve prosthesis relative to the aorta that makes the timing of valve expansion critical for proper placement of the expandable prosthetic valve and hence the survival of the patient.  
           [0014]    Finally, many of the challenges discussed in the foregoing section pertaining to aortic valve replacement are also relevant to other procedures in the aortic root such as aortic valve resection, aortic valve decalcification, stent grafting for aortic dissections, etc.  
         SUMMARY OF THE INVENTION  
         [0015]    It is, therefore, one object of the present invention to enable the passage of a device from the left atrium, through the left ventricle, and into the arterial system.  
           [0016]    Further, another object of the present invention is to enable the implantation of a device in the arterial system without cardiopulmonary bypass.  
           [0017]    Further, another object of the present invention is to enable the implantation of a prosthetic valve in the arterial system without cardiopulmonary bypass.  
           [0018]    Another object of the present invention is to allow the insertion of such a valve while minimizing the risks to the patient posed by large arterial incisions.  
           [0019]    And another object of the present invention is to simplify the precise placement of such a valve.  
           [0020]    Further, another object of the present invention is to enable the implantation of a device other than a valve, such as but not limited to a valve resection tool, a decalcifying tool, an aortic valve repair tool, or a stented aortic graft, in the arterial system without cardiopulmonary bypass.  
           [0021]    Another object of the present invention is to allow the insertion of a device other than a valve, such as but not limited to a valve resection tool, a decalcifying tool, an aortic valve repair tool, or a stented aortic graft, while minimizing the risks to the patient posed by large arterial incisions.  
           [0022]    And another object of the present invention is to simplify the precise placement of a device other than a valve, such as but not limited to a valve resection tool, a decalcifying tool, an aortic valve repair tool, or a stented aortic graft.  
           [0023]    The present invention relates to a method and apparatus for positioning a device in the arterial system. More specifically, the present invention relates to a method and apparatus for positioning an aortic valve prosthesis in the aorta or aortic outflow tract, with or without cardiopulmonary bypass.  
           [0024]    One aspect of the present invention is a method for deploying an aortic valve prosthesis. This valve prosthesis may include any of the known aortic valves including, but not limited to, stented and unstented bioprosthetic valves, stented mechanical valves, and expandable or self-expanding valves, whether biological or artificial.  
           [0025]    In one aspect of the invention, there is provided a method of inserting a prosthesis or device from a lower pressure region into a higher pressure region of the cardiovascular system comprising the steps of: making an opening in a wall of a lower pressure region of the cardiovascular system; advancing the prosthesis or device through the opening and into the lower pressure region; and advancing the prosthesis or device through a natural barrier between the lower pressure region and the higher pressure region.  
           [0026]    In another aspect of the invention, there is provided a method of inserting a prosthesis or device into a vessel within the arterial system comprising the steps of: making an opening in a wall of a low pressure region of the heart; advancing the prosthesis or device through the opening and into the low pressure region; advancing the prosthesis or device through a natural barrier between the low pressure region and the left ventricle; and advancing the prosthesis or device from the left ventricle into the arterial system and the vessel.  
           [0027]    And in another aspect of the invention, there is provided a method of inserting a prosthesis or device into a vessel within the arterial system comprising the steps of: making an opening in a wall of the left atrium; advancing the prosthesis or device through the opening and into the left atrium; advancing the prosthesis or device through the mitral valve and into the left ventricle; and advancing the prosthesis or device from the left ventricle into the arterial system and the vessel.  
           [0028]    And in another aspect of the present invention, there is provided a method for positioning a device in the arterial system comprising the steps of: making a first opening leading to the left atrium; passing a valve prosthesis through the first opening and into a cardiac chamber of the left side of the heart using a first manipulation instrument; making a second opening in the arterial system and advancing one end of a second manipulation instrument through the second opening and into the aforementioned cardiac chamber; securing the second manipulation instrument to the valve prosthesis; and then using the second manipulation instrument to retract at least some portion of the valve prosthesis out of the aforementioned cardiac chamber.  
           [0029]    An alternative method for positioning a device in the arterial system comprises the steps of: making an opening leading to the left atrium; passing a valve prosthesis through the opening and into a cardiac chamber of the left side of the heart using an articulating manipulation instrument; using the articulating manipulation instrument to guide the valve prosthesis into the arterial cardiac chamber; releasing the valve prosthesis into a desired position: and then retracting at least a portion of the articulating manipulation instrument out of the aforementioned cardiac chamber and left atrium.  
           [0030]    The pressure of blood flowing through the left atrium is very low, peaking at a few inches of water during the cardiac cycle. This pressure is a small fraction of that found within the arterial system and thus permits insertion of a conventional valve prosthesis through a relatively large opening formed in the wall of the left atrium without the risk of uncontrollable bleeding. In this respect it will be appreciated that various methods are known to those skilled in the art for controlling bleeding from an incision into the left atrium. The left atrium also rarely suffers from atherosclerotic plaque formation or calcification, thus minimizing the risk of embolic debris during such incision.  
           [0031]    Another aspect of the present invention is the use of a prosthesis holding apparatus for releasably holding the valve prosthesis during manipulation to its implant site. The prosthesis holding apparatus may be secured to the prosthetic valve at any suitable location(s) through the use of any of a variety of approaches including, but not limited to, suture loops, barbs, hooks, grasping jaws, opposing magnetic poles, friction fits and the like. The prosthesis holding apparatus is configured to provides first and second manipulation mounts for engagement by the aforementioned first and second manipulation instruments, respectively, whereby the prosthetic valve can be delivered to its implant site. This construction is highly advantageous in that it permits the valve prosthesis to be passed easily and reliably from the first manipulation instrument to the second manipulation instrument within the vascular system.  
           [0032]    In an alternative preferred embodiment, the prosthetic holding apparatus is attached on the ventricular side of the prosthesis. The aforementioned first manipulation instrument would articulate at or near the prosthetic valve to facilitate manipulation of the prosthesis holding apparatus (and hence the prosthesis itself) through the smallest possible incision site, then through the left atrium, the mitral valve and within the heart to align and position the prosthesis within the aortic annulus or left ventricular outflow track. In this alternative embodiment, there is no need for the aforementioned second manipulation instrument or the second manipulation mount.  
           [0033]    In addition, if the prosthesis holding apparatus is attached on the aortic side of the prosthesis, the manipulation instrument may articulate and may be introduced into the arterial system, brought across the mitral valve into the left atrium, out the left atrium to pick up the prosthesis holding apparatus (and hence the prosthesis) and then retracted back to position the prosthesis directly into the aortic annulus without the need for another manipulation instrument. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0034]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like elements and further wherein:  
         [0035]    [0035]FIG. 1 is a schematic side view showing the introduction of a valve prosthesis and prosthesis holding apparatus into the left atrium of the heart, through an atriotomy, using a first manipulation instrument;  
         [0036]    [0036]FIG. 2 is a schematic side view showing passage of the apparatus of FIG. 1 from the left atrium, through the mitral valve, and into the left ventricle;  
         [0037]    [0037]FIG. 3 is a schematic side view showing the introduction of a second manipulation instrument into the left ventricle through an arteriotomy into the arterial system;  
         [0038]    [0038]FIG. 4 is a schematic side view showing the second manipulation instrument being attached to the prosthesis holding apparatus while the first manipulation instrument remains secured to the prosthesis holding apparatus;  
         [0039]    [0039]FIG. 5 is a schematic side view similar to that of FIG. 4, except showing the first manipulation instrument being removed from the surgical site while the second manipulation instrument remains secured to the prosthesis holding apparatus;  
         [0040]    [0040]FIG. 6 is a schematic side view showing the second manipulation instrument positioning the prosthetic valve within the aorta prior to fixation;  
         [0041]    [0041]FIG. 7 is a schematic side view showing the prosthetic valve secured to the tissues of the aorta following removal of the second manipulation instrument and prosthesis holding apparatus;  
         [0042]    [0042]FIGS. 8, 9 and  10  are enlarged schematic views showing a preferred construction for the valve holding apparatus, and for the attachment to, and detachment from, the prosthetic valve; and  
         [0043]    [0043]FIG. 11 is a schematic view showing a guide for guiding the second manipulation instrument relative to the first manipulation instrument such that the second manipulation instrument will be aimed directly at the second manipulation mount when the first manipulation mount is secured to the first manipulation instrument. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0044]    The present invention can be used to implant a variety of prostheses into the arterial system or left side of the heart. The prosthesis used in the preferred embodiment is an aortic valve prosthesis. Alternatively, the prosthesis may comprise, but is not limited to, a cylindrical arterial stent, an arterial prosthesis or graft, a ventricular assist device, a device for the treatment of heart failure such as an intraventricular counterpulsation balloon, chordae tendinae prostheses, arterial filters suitable for acute or chronic filtration of emboli from the blood stream, arterial occlusion devices and the like.  
         [0045]    For clarity of illustration, the present invention will hereinafter be discussed in the context of implanting an aortic valve prosthesis.  
         [0046]    It should also be appreciated that the present invention may be practiced either “on-pump” or “off-pump”. In other words, the present invention may be performed either with or without the support of cardiopulmonary bypass. The present invention also may be performed either with or without cardiac arrest.  
         [0047]    Looking now at FIG. 1, there is shown an exemplary embodiment of the present invention. A prothesis holding apparatus  100  is secured to a prosthetic valve  200  so as to form a temporary prosthetic assembly  300 . A first manipulation instrument  400  is secured to a first manipulation mount  105  formed on prosthesis holding apparatus  100 , whereby temporary prosthetic assembly  300  may be moved about by first manipulation instrument  400 . Temporary prosthetic assembly  300  has been positioned in left atrium  5  by passing first manipulation instrument  400  through atriotomy  10 . Alternatively, the temporary prosthetic assembly  300  could be passed into the left atrium  5 , using first manipulation instrument  400 , through any of the pulmonary veins  15 . And in another form of the invention, temporary prosthesis assembly  300  could be passed into the left atrium by first passing the assembly into the right atrium via an atriotomy, and then into the left atrium through an incision made in the interatrial septum.  
         [0048]    Prosthetic valve  200  is preferably a conventional mechanical aortic valve of the sort well known in the art, although other forms of valve prostheses may also be used.  
         [0049]    In one preferred form of the invention, first manipulation instrument  400  functions by virtue of the relative motion of an outer cannula  405  relative to an inner grasper  410 . More particularly, inner grasper  410  has an elastically deformable distal gripper  415  which is open when the gripper is outside of outer cannula  405 . However, when deformable gripper  415  is pulled at least partially into or against outer cannula  405 , gripper  415  is elastically deformed into a closed position, whereby it may grip an object, e.g., first manipulation mount  105  formed on prosthesis holding apparatus  100 . First manipulation instrument  400  is shown in FIG. 1 in its closed position, wherein deformable gripper  415  is closed about first manipulation mount  105 , such that prosthesis holding apparatus  100 , and hence the entire temporary prosthetic assembly  300 , is held secured to the distal end of first manipulation instrument  400 .  
         [0050]    The specific embodiment of first manipulation instrument  400  shown in FIG. 1 is presented as an illustrative example only, and is not intended to limit the scope of the present invention. Many other arrangements may be used for releasably gripping first manipulation mount  105  formed on prosthesis holding apparatus  100 . Furthermore, first manipulation mount  105  may itself have many potential shapes and properties to enable releasable attachment to first manipulation instrument  400 . Other possible configurations for releasably securing first manipulation mount  105  to first manipulation instrument  400  include, but are not limited to, opposing magnet poles in the mount and instrument, adhesives, a press fit between mount and instrument, threaded couplings, suture loops, a balloon or balloons expanded within a mating cavity, collapsible barbs, etc. For the purposes of the present invention, the important point is that some arrangement be provided for releasably securing the prosthesis holding apparatus (and hence the prosthetic valve) to a manipulation instrument.  
         [0051]    Still looking now at FIG. 1, first manipulation instrument  400  is shown as having a long axis that extends outside of the heart, with first manipulation instrument  400  being straight along that axis. However, it should also be appreciated that first manipulation instrument  400  may, alternatively, be formed with a curve at one or more location along this length. Furthermore, first manipulation instrument  400  may be constructed so as to allow articulation at the distal end, the proximal end, or both, or at any point therebetween. In addition, first manipulation instrument  400  may be formed either entirely rigid or substantially flexible, along all or part of its length.  
         [0052]    First manipulation instrument  400  is also shown as having a relatively small dimension perpendicular to its long axis. This configuration allows atriotomy  10  to be reduced in size after the passage of temporary prosthetic assembly  300  into left atrium  5 . This perpendicular dimension may be constant or varied along the long axis of first manipulation instrument  400 .  
         [0053]    The specific embodiment of the prosthesis holding apparatus  100  shown in FIG. 1 is presented as an illustrative example only, and is not intended to limit the scope of the present invention. Many other arrangements may be used for releasably gripping prosthetic valve  200  and for providing first manipulation mount  105 , as well as providing a second manipulation mount  110  that will be discussed below. In FIG. 1, first manipulation mount  105  and second manipulation mount  110  are shown as spherical additions to struts  115  extending away from prosthetic valve  200 . These spheres are intended to fit, respectively, within the deformable gripper  415  of first installation instrument  400  and the deformable gripper  515  of a second installation instrument  500  (discussed below). First manipulation mount  105  and/or second manipulation mount  110  could, alternatively, be indentations within a portion of male or female threaded extensions from, magnetized surfaces of, slots or holes in or through, prosthesis holding apparatus  100 , etc. Furthermore, first manipulation mount  105  and/or second manipulation mount  110  could be portions of the struts  115  extending away from prosthetic valve  200 , where those portions may be either reduced or enlarged in dimension relative to neighboring portions of the struts. Many other constructions may also be used to form first manipulation mount  105  and second manipulation mount  110 . For the purposes of the present invention, the important point is that some arrangement be provided for releasably securing the prosthesis holding apparatus (and hence the prosthetic valve) to manipulation instruments.  
         [0054]    Still looking now at FIG. 1, it will be appreciated that the native aortic valve has been removed. Removal of the native aortic valve is not a necessary element of the present invention, but may be incorporated into the preferred method. Removal of the native aortic valve may be accomplished either before or after passage of the temporary prosthetic assembly  300  into left atrium  5 .  
         [0055]    When the methods and devices of the present invention are employed during an off-pump valve replacement procedure, it may be beneficial to provide temporary valves and/or filters in the arterial system, downstream of the site of the native aortic valve. Thus, for example, in FIG. 2 there is shown a temporary valve  600  which may be used to support cardiac function during and following removal of the diseased cardiac valve. Temporary valve  600  is shown positioned in aorta  20 . Alternatively, temporary valve  600  may be positioned in the aortic arch or the descending aorta. In addition, temporary valve  600  may incorporate a filter therein to mitigate the risks of embolic complications. Alternatively, a separate filter may be employed within the aorta and/or the branch arteries extending therefrom.  
         [0056]    [0056]FIG. 2 shows first manipulation instrument  400  being used to manipulate temporary prosthetic assembly  300  (and hence prosthetic valve  200 ) into left ventricle  25  through mitral valve  30 . After temporary prosthetic assembly  300  has passed into left ventrical  25 , the first manipulation instrument  400  will continue to traverse mitral valve  30 ; however, the reduced perpendicular cross-section of first manipulation instrument  400  will cause only minimal disruption of the function of mitral valve  30 .  
         [0057]    [0057]FIG. 3 shows the insertion of a second manipulation instrument  500  through the arterial system and into left ventricle  25 . Second manipulation instrument  500  is shown being inserted through an incision  35  on aorta  20 . Alternatively, second manipulation instrument  500  could be inserted into a central or peripheral artery and than advanced into left ventricle  25 . Aortic incision  35  is small relative to the atriotomy  10  formed in left atrium  5 .  
         [0058]    Bleeding through incision  35  may be readily controlled through a variety of means. These include, but are not limited to, employing a valved or un-valved arterial cannula, a purse-string suture placed around incision  35  and then pulled tight about second manipulation instrument  500 , a side-arm graft sewn to aorta  20  that may be constricted about a region of second manipulation instrument  500 , the use of a tight fit between a portion of second manipulation instrument  500  and aortic incision  35 , etc.  
         [0059]    Second manipulation instrument  500  is shown in FIG. 3 as being of the same form and function of first manipulation instrument  400 . Again, outer cannula  505  fits around inner grasper  510 , and the relative motion between grasper  510  and cannula  505  can be used to deform gripper  515  between open and closed positions. Alternatively, second manipulation instrument  500  may have any of the variety of other forms and functions described above with respect to first manipulation instrument  400 . Furthermore, second manipulation instrument  500  is preferably of a smaller dimension perpendicular to its long axis than first manipulation instrument  400  so as to reduce the risks posed by arteriotomy  35 .  
         [0060]    [0060]FIG. 4 shows second manipulation instrument  500  being secured to the second manipulation mount  110  formed on prosthesis holding apparatus  100 . This is done while first manipulation instrument  400  is secured to first manipulation mount  105  formed on prosthesis holding apparatus  100 , in order that temporary prosthetic assembly  300  will be under control at all times during the “hand-off” between first manipulation instrument  400  and second manipulation instrument  500 .  
         [0061]    It should be appreciated that the orientation of second manipulation mount  110  is preferably such as to enable the long axis of second manipulation instrument  500  to be substantially perpendicular to the flow area of prosthetic valve  200 . This arrangement is particularly helpful when guiding prosthetic valve  200  into its final position within aorta  20  as shown hereafter in FIGS. 6 and 7.  
         [0062]    The use of two separate manipulation instruments, and the method of passing valve prosthesis  200  from one to the other, avoids the complex manipulations of valve prosthesis  200  that would be required to position valve  200  within aorta  20  using only a single manipulation instrument introduced through the left atrium. In this respect it should be appreciated that such a “single manipulation instrument” technique has been found to be possible, however, and is best facilitated by using a manipulation instrument capable of bending or articulating at or near the site of its attachment to valve holding apparatus  100 . In this respect it has been found that it can be particularly advantageous to provide a manipulation instrument capable of bending or articulating within about 4 cm or so of the point of attachment to valve holding apparatus  100 . It has also been found that it can be particularly advantageous for such an articulating instrument to be able to deflect its distal tip by an angle of between about 90 to 180 degrees from the long axis of the first manipulation instrument  400  shown in FIG. 4.  
         [0063]    The angular offset of first manipulation mount  105  and second manipulation mount  110  is preferably set to facilitate passage of temporary prosthetic assembly  300  from left atrium  5  to aorta  20  using two substantially straight manipulation instruments, e.g., first manipulation instrument  400  and second manipulation instrument  500 . This angle is preferably approximately 45 degrees. However, this angle may also be varied so as to optimize passage of different valve designs or other prostheses using curved, straight or articulating manipulation instruments from various access sites into the left atrium and arterial system. This angle may be fixed or variable on a given prosthesis holding apparatus  100 .  
         [0064]    Once second manipulation instrument  500  is safely secured to second manipulation mount  110 , first manipulation instrument  400  may be released from first manipulation mount  105  and removed from left ventricle  5 , as shown in FIG. 5. Alternatively, first manipulation instrument  400  may remain secured to prosthesis holding apparatus  100  or prosthetic valve  200  by a flexible tether so as to facilitate re-attachment of first manipulation instrument  400  to valve holding apparatus  100  if necessary.  
         [0065]    [0065]FIG. 6 shows temporary prosthesis assembly  300  being positioned by second manipulation instrument  500  at a preferred fixation site. This fixation site is preferably upstream of or proximal to the coronary arteries, although this position is not a restrictive requirement of the present invention.  
         [0066]    [0066]FIG. 7 shows valve prosthesis  200  secured to the walls of aorta  30  and removal of second manipulation instrument  500  and prosthesis holding apparatus  100 . In this respect it should be appreciated that prosthesis holding apparatus  100  is preferably wholly or partially flexible, or otherwise collapsible, so as to allow the prosthesis holding apparatus  100  to be collapsed radially and then withdrawn through arteriotomy  35  after prosthesis holding apparatus  100  has been released from prosthetic valve  200 . Alternatively, prosthesis holding apparatus  100  may be removed from the vascular system, either partially or entirely, through atriotomy  10  by first manipulation instrument  400 , by a tether leading therefrom, or a separate instrument. Of course, in the situation where prosthesis holding apparatus  100  is to be removed via atriotomy  10 , the prosthesis holding apparatus  100  should be appropriately mounted to prosthetic valve  200 , i.e., prosthesis holding apparatus  100  should be positioned on the atriotomy side of the valve.  
         [0067]    In FIG. 7, valve prosthesis  200  is shown secured to aorta  30  using barbs or staples  700 . Barbs or staples  700  may be a component of, and/or deployed from, prosthesis holding apparatus  100 , and/or valve prosthesis  200 , and/or a separate fixation device. Alternatively, barbs or staples  700  may be deployed by a separate instrument inserted through the outer surface of aorta  30 , from a remote site in the arterial system, through atriotomy  10  or through some other incision into a cardiac chamber or great vessel.  
         [0068]    Looking next at FIGS.  8 - 10 , there is shown one preferred configuration for prosthesis holding apparatus  100 . More particularly, prosthesis holding apparatus  100  comprises a base  120  having a longitudinal opening  123  (FIG. 9) therein for slidably receiving a rod  125  therethrough. Base  120  also comprises a plurality of side slots  130 . Each side slot  130  has a strut  115  pivotally connected thereto. Slots  130  are constructed so that each strut  115  can pivot freely between (i) the position shown in FIGS. 8 and 9, and (ii) the position shown in FIG. 10. A body  135  is mounted on rod  125 . A plurality of wire fingers  140  are secured to body  135 . Wire fingers  140  extend through holes  145  formed in base  120  and extend around the cuff  205  of prosthetic valve  200 . Second manipulation mount  110  is secured to the proximal end of rod  125 . First manipulation mount  105  is secured to one of the struts  115 . Alternatively, as noted above, first manipulation mount  105  may be formed by a strut  115  itself, provided that first manipulation instrument  400  is appropriately adapted to engage the strut  15  directly.  
         [0069]    In use, prosthesis holding apparatus  100  is fit about valve prosthesis  200  so that wire fingers  140  hold valve cuff  205  to struts  115 . Prosthesis holding apparatus  100  is then engaged by first manipulation instrument  400 , using first manipulation mount  105 , and moved into and through right atrium  5 , through mitral valve  30  and into left ventricle  25 . Then second manipulation tool  500 , comprising outer cannula  505  and inner grasper  510  having the deformable gripper  515 , engages second manipulation mount  110 . The distal tip  520  of outer cannula  505  is placed against edge  150  of base  120  and gripper  515  is drawn proximally within outer cannula  505  until deformable gripper  515  engages shoulder  525 , whereupon prosthesis holding apparatus  100  (and hence prosthetic valve  200 ) will be mounted to second manipulation tool  500 . Second manipulation tool  500  is then used to maneuver temporary prosthetic assembly  300  into position, whereupon the valve&#39;s cuff  205  is secured to the side wall of the aorta, e.g., with barbs, staples, suture, etc. Then prosthesis holding apparatus  100  is detached from prosthetic valve  200  by pulling inner grasper  510  proximally relative to outer cannula  505  so that wire fingers  140  are pulled past valve cuff  205  (FIG. 9), whereby to free prosthesis holding apparatus  100  from the prosthetic valve  200 . Then second manipulation instrument  500  is withdrawn out aorta  20  and arteriotomy  35 , with struts  115  folding inwardly (FIG. 10) so as to pass through the arteriotomy. Struts  115  can be adapted to fold inwardly through engagement with the walls of the arteriotomy  35  or, alternatively, additional means (such as springs, cams, etc.) can be provided to fold struts  115  inwardly.  
         [0070]    In practice, it has been found that it can sometimes be difficult to locate second manipulation mount  110  with second manipulation instrument  500  so as to “hand off” temporary prosthesis assembly  300  from first manipulation instrument  400  to second manipulation instrument  500 . This can be particularly true where the procedure is to be conducted “off-pump”, i.e., without stopping the heart. To this end, and looking now at FIG. 11, there is shown a guide  800  for guiding second manipulation instrument  500  relative to first manipulation instrument  400  such that second manipulation instrument  500  will be aimed directly at second manipulation mount  110  when first manipulation mount  105  is secured to first manipulation instrument  400 . More particularly, guide  800  comprises a first passageway  805  for slidably receiving first manipulation instrument  400 , and a second passageway  810  for slidably receiving second manipulation instrument  500 . Passageways  805  and  810  are oriented so that second manipulation instrument  500  will be aimed directly at second manipulation mount  110  when temporary prosthesis assembly  300  is held by first manipulation instrument  400  engaging first manipulation mount  105 .  
         [0071]    In accordance with the present invention, it is also possible to enter the left atrium other than through an exterior wall of the left atrium. Thus, for example, it is possible to introduce the prosthetic valve through an opening in an exterior wall of the right atrium, pass the prosthetic valve through an incision in the interatrial septum and across to the left atrium, and then advance the prosthetic valve to its implantation site via the mitral valve and the left ventricle.  
         [0072]    As noted above, the manipulation instrument(s) do not need to take the form of the installation instrument  400  or  500 . It is also possible to deliver the prosthetic valve to its implant site using a guidewire and a pusher tool riding on the guidewire.  
         [0073]    Thus, for example, in an alternative preferred embodiment, a wire, a catheter, a tube or any other filament can be placed from the left atrium, through the ventricle and into the arterial system, over (or through) which a prosthesis or device can be advanced (pushed or pulled). As an example, a catheter with a balloon can be placed through an incision in the left atrial wall. The balloon can be inflated and this catheter can then be “floated” along the flow of blood across the mitral valve, into the left ventricle, and out into the arterial system. At that point the catheter can be grasped by an instrument placed through a small incision in the aorta or passed into the aorta by means of a remote vessel such as the femoral artery. At this point, the prosthesis or device can be mounted onto the catheter and either be pushed (or pulled) over the catheter into position. This procedure can be similarly performed by the use of a wire or other filament structure. Also, a tube could be employed, with the prosthesis or device being advanced within the tube.