Patent Publication Number: US-2004059413-A1

Title: Suture template for facilitating implantation of a prosthetic heart valve

Description:
RELATED APPLICATIONS  
     [0001] The present application claims priority to U.S. Provisional Application Serial No. 60/412,415, filed Sep. 20, 2002. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention is related generally to a suture template for assisting surgeons in placing sutures or marking locations where a valve prosthesis is to be attached.  
       BACKGROUND  
       [0003] Prostheses are artificial devices used to repair or replace damaged or diseased organs, tissues and other structures in humans and animals. Prostheses must be generally bio-compatible since they are typically implanted for extended periods of time. For example, prostheses can include artificial hearts, artificial heart valves, ligament repair material, vessel repair material, surgical patches constructed of mammalian tissue and the like.  
       [0004] Prosthetic heart valves are used to replace diseased natural heart valves in the aortic, mitral, tricuspid and pulmonary positions in the heart. Examples of three such valves are shown in Carpentier et al. U.S. Pat. No. 4,106,129, Ionescu et al. U.S. Pat. No. 4,084,268 and Davis et al U.S. Pat. No. 4,192,020. As shown by these patents, a prosthetic heart valve typically includes a stent formed of a wire or a shell, and valve leaflets attached to the stent. U.S. Patent No. 4,501,030, issued to Lane, discloses another prosthetic heart valve which includes a frame having a plurality of commissure supports, a plurality of resilient supports, and a plurality of valve leaflets. The valve leaflets are attached to the resilient supports, and the resilient supports lie radially outwardly of the commissure supports, respectively. When in use, the valve is subjected to forces which are used to clamp the valve leaflets between the resilient supports and the commissure supports to augment any leaflet attachment techniques that may be used.  
       [0005] The natural aortic heart valve has three leaflets that open to allow flow into the aorta and close to prevent back flow into the left ventricle. Each of the three leaflets of the natural aortic heart valve is attached to the cylindrical wall of the aorta along a non-planar curve. A typical aortic prosthetic valve includes three valve leaflets attached to a post frame. Some relatively recent valve designs require that the valve be secured in position via an undulating suture line that generally follows the cusps and commissure supports of the wireframe. Coronary arteries, however, join the aorta near the valve. Thus the commissure post of the prosthetic heart valve, if located improperly in the aorta, can block or partially block a coronary artery. This complicates the placement of the prosthesis.  
       [0006] Valve replacement is typically performed during open-heart surgery. The natural valve is mounted in an annulus comprising dense fibrous rings attached either directly or indirectly to the atrial and ventricular muscle fibers. In a valve replacement operation, the damaged leaflets are typically excised and the annulus sculpted to receive the replacement valve. Ideally the annulus presents relatively healthy tissue which can be formed by the surgeon into a uniform ledge projecting into the orifice left by the removed valve. The time and spatial constraints imposed by surgery, however, often dictate that the shape of the resulting annulus is less than perfect for attachment of a sewing ring of the replacement valve. Moreover, the annulus may be calcified as well as the leaflets and complete annular debridement, or removal of the hardened tissue, results in a larger orifice and less defined annulus ledge to which to attach the sewing ring of the prosthesis. In short, the contours of the resulting annulus vary widely after the natural valve has been excised.  
       [0007] During replacement, the annulus is sized with an annulus sizer to determine the proper size of the artificial valve. The artificial valve is then positioned in the opening and the sewing ring is carefully sutured or sewn to the tissue surrounding the valve opening. The annulus sizer is typically cylindrical, and made of plastic with a central threaded tap to which a handle is attached. A number of sizers are at a surgeon&#39;s disposal, each having a different size, or diameter. In use the surgeon inserts the sizer into the valve opening, measuring the size of the opening. An artificial valve properly sized for the valve opening is then selected and sewn in place.  
       [0008] Prior to attaching the prosthetic valve to the annulus and/or aorta, it is also helpful for the surgeon to mark the location within the aorta where the prosthetic valve is to be attached. Failure to mark the proper location where the prosthetic valve is to be precisely attached could lead to undesirable consequences including improper placement of the prosthetic valve.  
       SUMMARY  
       [0009] In one embodiment, a suture template for facilitating implantation of a prosthetic heart valve in a patient is disclosed. The suture template includes an annular body having a plurality of commissure portions and a plurality of cusp portions. The plurality of commissure portions are connected with each other utilizing the plurality of cusp portions. In one embodiment, each commissure portion of the suture template includes a pair of upstanding arms extending from the cusp portions, the arms coming together to form a tip and defining an elongated downwardly opening notch between the arms. The cusp portions can also be provided with at least one notch. The notches, which can open toward the top and/or bottom, facilitate the removal of the suture template. All notches on the commissure portions as well as cusp portions represent major reference points for suture placement for implanting the prosthetic valve.  
       [0010] In a further embodiment of the invention, a method of marking a location to implant a prosthetic heart valve in a patient, utilizing a suture template, is disclosed. The method includes placing the suture template in the location of the heart that is to receive the valve, placing a plurality of spaced apart sutures through notches along one end of the suture template and through and along the desired location of the heart and removing the suture template, and placing the sutures into the prosthetic valve that is to be implanted. Instead of a notch, any other physical or visual guide of the template may be used to assist the surgeon in suture placement.  
       [0011] In yet another embodiment, the invention provides a method of marking a location for implanting an artificial device by a surgeon. The method includes lowering a marking tool within a body cavity, positioning the marking tool where the artificial device is to be implanted within the body cavity, and triggering a marking element while firmly holding the marking tool at a desired location to mark positions. The marking of the positions is accomplished by dispensing the marking material on the body cavity tissues, which helps to facilitate a placement of sutures by the surgeon.  
       [0012] In yet a further embodiment, a marking tool for marking a location for implanting an artificial device by a surgeon is disclosed. The tool includes a button, a cylindrical handle, an actuator, a wire guide arrangement having a plurality of stainless steel tubes, a wire retaining plug mounted within the handle and positioned on top of a spring within the handle, a plurality of flexible wires press fitted within the wire retaining plug and positioned within the stainless steel tubes of the wire guide arrangement, and a prosthetic template connected to the handle. The handle has a central axis, a top end and a bottom end, and a bore extending through the handle around the central axis. The actuator rod is positioned within the bore of the handle and retained within the handle at a fixed location to engage the button when the button is threadably engaged with the handle. The actuator rod is retained in the handle by utilizing a pin.  
       [0013] The stainless steel tubes are partly mounted inside the handle and partly protruding outside the handle. A wire guide is engaged on the bottom end of the handle to seal the bore and to remain in contact with a spring positioned within the handle. The plurality of flexible wires are positioned within each respective stainless steel tube. Two or more wires are selected depending on the application.  
       [0014] The prosthetic template, in one embodiment, has a generally cylindrical section. The prosthetic template of the marking tool further includes a plurality of holes to accommodate the stainless steel tubes protruding out of the wire guide arrangement. The plurality of the stainless steel tubes are connected to the handle around the central axis by utilizing a support plate mounted within the prosthetic template and a support pin connected to the support plate and to the wire guide. The support pin provides additional support to the prosthetic template around the central axis of the handle.  
       [0015] In another embodiment of the invention, the prosthetic template includes a plurality of commissure portions. The plurality of commissure portions extends upward from the annular base corresponding to a prosthetic valve. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016] The invention is best understood from the following description when read in conjunction with the accompanying drawings. Included are the following figures:  
     [0017]FIG. 1 is a sectional view through the left half of a human heart showing a systolic phase of left ventricular contraction;  
     [0018]FIG. 2 is a sectional view through the left half of a human heart showing a diastolic phase of left ventricular expansion;  
     [0019]FIG. 3 is a perspective view of a prosthetic heart valve;  
     [0020]FIG. 4 a  is a perspective view of an embodiment of a suture template of the present invention;  
     [0021]FIG. 4 b  is a top view of the suture template of FIG. 4 a;    
     [0022]FIG. 4 c  is a sectional view taken along line  4 - 4  of FIG. 4 b;    
     [0023]FIG. 4 d  is a perspective view of an alternative embodiment of a suture template of the present invention.  
     [0024]FIG. 5 is a schematic view showing the placement of the suture template of FIG. 4 a  in the aorta of a patient;  
     [0025]FIG. 6 is a perspective view of a marking tool for facilitating a heart valve replacement;  
     [0026]FIG. 7 is an exploded perspective view of the marking tool of FIG. 6;  
     [0027]FIG. 8 is a perspective view of a prosthetic template of the marking tool of FIG. 6;  
     [0028]FIG. 9 is a partial cut-away view further showing an assembly of the marking tool of FIG. 6; and  
     [0029]FIG. 10 is a partial cut-away view of the marking tool of FIG. 6. 
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
     [0030] The present invention relates to a suture template for assisting surgeons in marking a location and, more specifically, to a suture template for facilitating a prosthetic heart valve replacement.  
     [0031] To better illustrate the advantages of the suture template of the present invention, a brief understanding of the heart and of a prosthetic heart valve is helpful. To assist in properly implanting the prosthetic heart valve, the suture template of the present invention may be employed.  
     [0032]FIGS. 1 and 2 illustrate an understanding of the movement of the annulus of the aorta of the heart  10 . In this regard, FIGS. 1 and 2 illustrate the two phases of left ventricular function; systole and diastole. Systole refers to the pumping phase of the left ventricle, while diastole refers to the resting or filling phase. FIGS. 1 and 2 illustrate in cross section the left chamber of the heart with the left ventricle  20  at the bottom, and the ascending aorta  22  and left atrium  24  diverging upward from the ventricle to the left and right, respectively.  
     [0033]FIG. 1 illustrates systole with the left ventricle  20  contracting, while FIG. 2 illustrates diastole with the left ventricle dilating. The aortic valve  28  is schematically illustrated here as having leaflets  30 . A natural aortic valve typically has three leaflets, and a vertically oriented flow axis, wherein the leaflets are usually evenly distributed circumferentially about 120° apart. In this regard it will be understood that the cross-sections shown are not taken in a single plane, but instead are taken along two planes angled apart 120° with respect to one another and meeting at the midpoint of the aorta  22 . Contraction of the ventricle  20  causes the mitral valve  26  to close and the aortic valve  28  to open, and ejects blood through the ascending aorta  22  to the body&#39;s circulatory system, as indicated in FIG. 1 by the arrows  32 . Dilation of the ventricle  20  causes the aortic valve  28  to close and the mitral valve  26  to open, and draws blood into the ventricle from the left atrium  24 , as indicated in FIG. 2 by the arrows  33 .  
     [0034] The walls of the left chamber of the heart around the aortic valve can be generally termed the annulus region  34  and the sinus region  36 . The annulus region  34  generally defines an orifice that is the narrowest portion between the ventricle  20  and the ascending aorta  22 , and which is composed of generally fibrous tissue. The sinus region  36  is that area just downstream from the annulus region  34  and includes somewhat elastic, less fibrous tissue. Specifically, the sinus region  36  typically includes three identifiable, generally concave sinuses (formally known as Sinuses of Valsalva) in the aortic wall intermediate the upstanding commissures of the valve  28 . The sinuses are relatively elastic and are constrained by the intermediate, more fibrous commissures of the aortic annulus. Those of skill in the art will understand that the annulus region  34  and sinus region  36  are not discretely separated into either fibrous or elastic tissue, as the fibrous commissures of the annulus extend into the sinus region  36 . In addition, it will be appreciated that the valve may have only two leaflets or more than three leaflets, and that the leaflets whether two, three or more than three leaflets, may not be evenly distributed circumferentially. The suture template of the present invention is intended to be used in these less common situations also.  
     [0035] Each leaflet of the aortic valve has a lower cusp portion. The highest point of attachment of the leaflets to the aortic wall is called the commissure. Each commissure is connected between adjacent cusp portions and is generally axially aligned along the aortic wall. The triangular space below the commissure is called the interleaflet triangle. The tissues in this triangular space have much less dense connective tissue and are pliable and flexible. The three sinuses are located in the most proximal portion of the aorta, just above the cusps of the leaflets of the natural aortic valve. The sinuses correspond to the individual cusps of the aortic valve.  
     [0036] With reference to FIG. 3, a relatively new style of prosthetic heart valve  40  includes a trifoliate valve with three leaflets  42 . Although three leaflets are described, and mimic the natural aortic valve, the principles of the present invention can be applied to the construction of a prosthetic valve with two or more leaflets, depending on the need.  
     [0037] The leaflets  42  each include an arcuate lower cusp edge  50  terminating in upstanding commissure regions  52 . Each leaflet  42  includes a coapting or free edge  54  opposite the cusp edge  50 . The cusp edges  50  and commissure regions  52  are secured around the periphery of the valve, with the free edges  54  permitted to meet or “coapt” in the middle. A stent assembly  46  also includes three cusps separated by three upstanding commissures. Further details regarding the structure of the heart and implanting of a prosthetic heart valve of the style illustrated in FIG. 3 is described in U.S. application Ser. No. 09/847,930, filed May 3, 2001, incorporated herein by reference. It will also be appreciated by those skilled in the art that the suture template of the present invention and its method of use may be adapted for use in any of the valves of the heart and may be used with other types of prosthetic heart valves.  
     [0038] Implanting the more traditional prosthetic aortic heart valves typically involves excising the natural leaflets and attaching the prosthetic heart valve along the relatively planar fibrous annulus. Implanting a valve such as that illustrated in FIG. 3 in which the sewing area more closely follows the undulating path along the leaflets&#39;cusps and commissures is more complicated. This valve is designed to be more flexible and thus the sewing ring undulates from cusp to commissure and thus requires better sewing guidance.  
     [0039] To assist in properly locating such a prosthetic heart valve, the suture template of the present invention may be employed. With reference to FIGS. 4 a - 4   c , a suture template  100  for an aortic valve includes three commissure portions  110  alternating with three cusp portions  120 . The commissure and cusp portions form an annulus defining an opening  132  therethrough having a central axis  134 . The template  100  has a circumference that is sized to fit the annulus region of the aorta.  
     [0040] Each cusp portion  120  preferably includes a convexly curved outer surface  130  that faces radially outward, a radially inwardly extending ledge  133  to facilitate positioning of the template within the aorta and a concavely curved upper surface  136  that correlates to the bottom margin of a cusp of a leaflet of the prosthetic valve. Centrally located on each cusp are one or more downwardly opening notches  138  size to locate and capture a suture. The notches also extend through the ledge. A tab (not shown) may also be provided on an inner wall of the template to assist in placement.  
     [0041] Each commissure portion  110  includes a pair of upstanding arms  140 ,  142  that come together at the top forming a rounded tip  144 . Each arm of the commissure portion extends from a respective adjacent cusp portion. The arms for each commissure portion are spaced apart at the bottom to define an elongated notch  146  that is open at the bottom and extends up to the underside of the rounded tip. The elongated notch is sized to locate and capture a suture at a location adjacent the rounded tip. Preferably, the elongated notch extends up from the base to a location above the lowermost point of the concavely curved upper surfaces  136  of the adjacent cusp portions  120 . The elongated notch permits the template to fit better in the annulus around remnants of the excised leaflets and provides flexibility to the template.  
     [0042] Additional notches may be placed in the template to locate and capture additional sutures. For example, additional downwardly extending notches may be placed at the junctures between ends of the cusps portions and respective lower ends of the arms of the commissure portions, such as shown at  148 ,  150  of FIG. 4 a.    
     [0043]FIGS. 4 a - 4   c  depict one embodiment of a template design. It will be understood by those skilled in the art, however, that several other configurations of the template are suitable for use in locating a prosthetic heart valve, including templates having different numbers of commissure and cusp portions, templates with different types of ledges or without ledges and templates with different types of surface configurations. In addition, the numbers of notches and notch placement can vary. For example, while notches  148 , 150  are illustrated extending downward, another embodiment would have the notches extend upward. The design of the suture template  100  is illustrated for the aortic position with three leaflets, but can be designed to the type of prosthetic heart valve to be implanted (e.g. mitral valve, pulmonary valve, tricuspid valve).  
     [0044] In one embodiment, the suture template is made out of a flexible material. In an exemplary embodiment, the material utilized in the suture template does not chip and is easy to cut. Suitable materials include, for example, polypropylene, polycarbonate, polystyrene or polyurethane and may be radio opaque to assist in locating the template by X ray. In another embodiment, the suture template is molded of silicone rubber.  
     [0045] The use of the suture template  100  in aortic heart valve replacement is described below in connection with FIG. 5. A prosthetic aortic valve of the type illustrated in FIG. 3 is typically implanted on the wall of the left ventricular outflow tract mostly above the anatomic ventriculoaortic junction. The lowest point of the semilunar point of attachment of the prosthetic valve may be on the ventricular side of the junction. After the patient has been anesthetized, and the chest is opened, the top part of the heart and the aorta are visible. The patient is then placed on a heart-lung bypass machine. The cardiac surgeon then makes an incision in the aorta to gain access to the natural valve by cutting the aorta radially just above the natural valve that is to be replaced. Sutures may be generally placed at the commissures (the position on the aortic wall where two cusps meet) to hold the root open and give the surgeon easy access to the working area. Once the valve is exposed, the surgeon inspects the valve and the aortic root surrounding it to determine the extent of disease. If the disease is limited to the natural valve cusps, then the natural valve cusps are cut out. After the diseased cusps have been removed and the surgeon is satisfied that the existing root tissue is healthy, a valve sizing tool, such as described in U.S. Pat. No. 6,350,281 B1 incorporated by reference herein, may be used to determine the optimal replacement valve size.  
     [0046] One type of the sizer that may be utilized is disclosed in PCT International Publication Number WO 00/64382, entitled “Aortic Heart Valve Prosthesis Sizer and Marker”, which is also incorporated herein by reference. The sizer described includes a prosthesis template and a handle extending from the prosthesis template. The prosthesis template includes a generally cylindrical section and a plurality of posts along the outflow edge extending upwardly from the generally cylindrical section around the circumference of the cylindrical section. The sizer system can include a plurality of sizing elements with prosthesis templates having different diameters.  
     [0047] It is common practice to use the largest valve that will fit to minimize the restriction of blood flow between the valve and the annulus wall. Once the size of the prosthesis has been determined it may be “dry fitted” to ensure that the valve geometry is compatible with the patient&#39;s annulus and aortic root. Generally, the prosthetic valve is attached to a holder for ease of handling and implantation. Various types of holders are described in a U.S. application Ser. No. 09/847,930, filed May 3, 2001, entitled FLEXIBLE HEART VALVE, mentioned earlier.  
     [0048] Based on the size of the prosthetic valve to be implanted, the surgeon selects a suture template  100  and places it in the aorta  22 , e.g. by holding a tab or a commissure portion, using e.g., forceps. The template is located such that the cusp portions  120  are aligned with the sinuses of the sinus region  36  and the commissure portions  110  are located between respective adjacent sinuses. The cusp portions are located such that the coronary artery located in two of the sinuses will remain open and unblocked to the flow of blood once the prosthetic valve is sewn in place.  
     [0049] Once the template  100  is in place, each notch of the template serves as a guide for receiving an individual suture  200 . Each suture typically has a thread  202  and two needles, needle A and a needle B, attached at each end of the thread. In one method, the surgeon starts with a commissure portion  110  and runs the needle A of the suture  200  from inside the template through the notch  146  into the wall  204  of the aorta  22  and out of the aorta wall and back into the cavity of the aorta. The surgeon takes the needle A and the needle B and inserts them into a suture organizer, such as described in U.S. Pat. No. 4,185,636 issued on Jan. 29, 1980 to Gabbay et al. to organize various sutures. Other equivalent suture organizers available may also be utilized. The suture organizer provides an orderly and controlled arrangement of the sutures.  
     [0050] The surgeon then takes additional sutures and runs them individually through the two other commissure portion notches  146  and takes the needles A&#39;s and B&#39;s of each respective suture and organizes them into the suture organizer. Next, the surgeon runs new sutures through the notches  138  in the cusp portions and the notches  148 ,  150  at the juncture between the cusp portions and the commissure portions and organizes the needles A&#39;s and B&#39;s of each suture into the suture organizer. In another method, the surgeon may simply use the notch that is most conveniently accessible to place initial sutures rather than placing sutures initially through the commissure portion notches  110 .  
     [0051] After the template  100  is sutured into position, the surgeon takes each needle of the suture  200  and threads it through the sewing ring of the prosthetic valve at a location corresponding to the sutures&#39; location in the patient. At this stage, each needle A is retained in the organizer and each needle B is threaded through the sewing ring of the prosthetic valve. The surgeon repeats this process for all of the remaining sutures ensuring that needles A of all the sutures are in the organizer and needles B of all the sutures are in the prosthetic valve.  
     [0052] After approximately 8-12 sutures have been positioned in the aortic wall utilizing the notches of the suture template  100  and sewn through the sewing ring on the prosthetic valve, the surgeon extracts the suture template  100  from the aorta. As few as three sutures is also possible. Using the notches on the template, the template may be removed by carefully pulling it in an appropriate direction such that the sutures fall away from the notches. In addition, or alternatively, the surgeon cuts the suture template  100  in one or more places to facilitate removal of the suture template  100  from the aorta. The pieces are then removed from the patient.  
     [0053] Once the suture template  100  is removed, the surgeon pushes the prosthetic valve along the sutures to its proper location within the aorta and uniformly tightens the knots of each suture around the sewing ring of the prosthetic valve. Tightening of the knots secures the prosthetic valve in the proper location. If desired, the prosthetic valve may be attached to a holder, such as described in U.S. application Ser. No. 09/847,930, filed May 3, 2001, to facilitate placement of the prosthesis at the proper location.  
     [0054] All the sutures, once uniformly tightened, ensure the proper implantation of the prosthetic valve. Pledgets may be used to reinforce the annulus, minimizing tearing of the tissue and the failure of sutures. After the sutures are tightened, the surgeon inspects the work to make sure that blood does not leak around the valve. The surgeon also inspects that the position of the prosthetic valve does not block the blood flow to the coronary arteries and the blood flow out of the heart. After the inspection, the extraneous lengths of sutures are cut off. Once the surgeon is satisfied that the valve is positioned correctly, the aorta is sutured back together. The heart is checked for any blood leakage, air bubbles are eliminated from the heart and the patient is removed from heart-lung bypass, closed, and sent to recovery.  
     [0055] In the above described method, the sutures were secured to the sewing ring of the prosthetic valve prior to removing the template. It will be appreciated, however, that the template may be removed prior to securing the sutures to the prosthesis. In another alternative, after the sutures have been located in the annulus region through use of the template, the template can be removed and the prosthesis sewn directly to the annulus using the sutures.  
     [0056] With reference to FIG. 4 d , an alternative embodiment of a template design has notches extending upward from the cusp portions. In particular, a suture template  100 ′ for an aortic valve includes three commissure portions  110 ′ alternating with three cusp portions  120 ′. The commissure and cusp portions form an annulus defining an opening  132 ′ therethrough having a central axis. The template  100 ′ has a circumference that is sized to fit the annulus region of the aorta.  
     [0057] Each cusp portion  120 ′ includes a convexly curved outer surface  130 ′ that faces radially outward, a radially inwardly extending ledge  133 ′ to facilitate positioning of the template within the aorta and a concavely curved upper surface  136 ′ that correlates to the bottom margin of a cusp of a leaflet of the prosthetic valve. Centrally located on each cusp is an upwardly opening notch  138 ′ that is sized to locate a suture. A tab (not shown) may also be provided on an inner wall of the template to assist in placement.  
     [0058] Each commissure portion  110 ′ includes a pair of upstanding arms  140 ′,  142 ′ that come together at the top forming a rounded tip  144 ′. Each arm of the commissure portion extends from a respective adjacent cusp portion. The arms for each commissure portion are spaced apart at the bottom to define an elongated notch  146 ′ that is open at the bottom and extends up to the underside of the rounded tip. The elongated notch is sized to locate and capture a suture at a location adjacent the rounded tip. Preferably, the elongated notch extends up from the base at least to a location above the lowermost point of the concavely curved upper surfaces  136 ′ of the adjacent cusp portions  120 ′. The elongated notch permits the template to fit better in the annulus around remnants of the excised leaflets and provides flexibility to the template.  
     [0059] Additional notches may be placed in the template to locate additional sutures. For example, additional upwardly extending notches may be placed at the junctures between ends of the cusps portions and respective lower ends of the arms of the commissure portions, such as shown at  148 ′,  150 ′ of FIG. 4 d.    
     [0060] The use of this suture template  100 ′ is similar to the use of the suture template of FIGS. 41 a - 4   c . However, because several notches extend upward from the cusp portions, instead of extending downward, these notches are simply used to assist in locating the suture and do not capture the suture as in the case of the downwardly extending notches shown in FIG. 5.  
     [0061] After sutures are positioned in the aortic wall, using the template  100 ′ as a guide, the template is removed by pulling it away and/or by cutting the template in one or more places to facilitate removal.  
     [0062] In another alternative embodiment, once the suture template  100 ,  100 ′ is strategically positioned at the annulus of the aorta, the surgeon uses a marker to mark the aorta through the notches. Once the position within the aorta is marked for the sutures, the surgeon runs the sutures through the marked positions and implants the prosthetic valve. In this embodiment, the suture template  100 ,  100 ′ is utilized simply as a guide to mark the positions for sutures rather than running the sutures through the notches as described earlier.  
     [0063] In yet another embodiment illustrated in FIG. 6, a marking tool  302 ,. is used for facilitating the replacement of the aortic valve. However, this is merely illustrative inasmuch as the features of this invention are equally applicable to marking positions of other heart valve replacements.  
     [0064] With reference to FIGS. 6 and 7, the marking tool  302  includes a button  304 , a handle  306 , and a wire guide arrangement  308  connected to a prosthetic template  310 . The marking tool  302  is utilized by inserting the marking tool  302  within the aorta, positioning the marking tool  302  where the prosthetic device is to be implanted, and pressing the button  304  of the marking tool  302  while firmly holding the marking tool  302  at a desired location to mark positions by a marking material to facilitate the placement of sutures by the surgeon.  
     [0065] Referring to FIG. 7, the button  304  includes a flat head  312  at a first end, a threaded post  314  at a second end, and a middle cylindrical portion  316  between the head and the threaded post. The.middle cylindrical portion  316  is sized to fit within a central bore  334  of the handle  306 . The post  314  at the second end is threaded to engage an actuator rod  318  when the actuator rod  318  is positioned within the handle  306 .  
     [0066] The actuator rod  318 , as shown in FIG. 7, includes a threaded groove portion  322  at a top end  324  and a flat surface  326  at a second end  328 . The threaded groove portion  322  includes internal threads sized to receive the threads of the post  314  of the button  304 . The actuator rod  318  has an outer diameter  329  sized to fit slidably within the central bore  334  of the handle. The actuator rod  318  further includes a slot  330  (shown in FIG. 9 below) of a pre-determined length to accommodate a vertical movement of the actuator rod  318  when the button  304  is depressed to eject the nitinol wires out of the prosthetic template  310 , as explained below. The details pertaining to the vertical movement is further shown and elaborated in FIGS. 9 and 10 below.  
     [0067] Referring again to FIGS. 6 and 7, the tubular-shaped handle  306  is formed by a cylindrical wall  332  having a central bore  334  to slidably accommodate the actuator rod  318  and a portion of the button  304 . The handle  306  has an axis of symmetry  340  and a small opening  342  perpendicular to the axis of symmetry  340  to receive a pin  344 . The pin  344  is positioned within the small opening  342  of the handle  306  and the slot  330  of the actuator rod  318  to facilitate the actuator movement in a vertical direction  345  when the button  304  is pressed. The handle  306  further includes a top end  345  and a bottom end  346 . The top end  345  is sized to receive the actuator rod  318  as well as the button  304 . The bottom end  346  is sized to receive a wire guide  390  of the wire guide arrangement  308 , as explained below.  
     [0068] Preferably, the outer surface of the handle  306  has indentations or raised ridges to provide a gripping surface such as, for example, a knurled surface. In an alternative embodiment, the handle  306  has a finished surface. The small size of the handle  306  provides flexibility to the surgeon while positioning the marking tool  302  at the proper location within the aorta during the surgery. In one embodiment, the handle  306  has a grip (not shown). The grip can have any convenient shape for gripping. The grip can include a button or other suitable structure for implementing marking when the marking tool  302  is properly positioned within the aorta. In another embodiment, if necessary, the handle  306  can be connected to an external power supply or the like to implement marking.  
     [0069] The marking tool  302  further includes a wire retaining plug  350  and a spring  352 . The spring  352  is provided to facilitate the vertical movement of the wire retaining plug  350 , when the spring and the plug are mounted within the handle. The wire retaining plug  350  is cylindrical in shape and is sized to fit within the bore  334  of the handle  306 . The wire retaining plug  350  has substantially the same diameter as the outer diameter  329  of the actuator rod  318  and includes a top surface  354  and a bottom surface  356 . The top surface  354  of the wire retained plug is frictionally in contact with the second end  328  of the actuator rod  318  when the wire retaining plug  350  is mounted within the handle  306 . A plurality of miniature openings  358  are provided on the bottom surface  356  of the wire retaining plug to receive a plurality of nitinol wires  360 . The wires  360  are press fitted into the miniature openings  358 . The wire retaining plug  350  is made out of a stainless steel material. In another embodiment, the wire retaining plug  350  is made out of a plastic or other material.  
     [0070] The wire guide arrangement  308  includes a wire guide  390  having a plurality of holes  392  on a periphery of the wire guide to accommodate a plurality of stainless steel tubes  430  at a pre-determined location. The wire guide  390  has a central aperture  394 , which is substantially concentric with the opening  334  and is sized to receive a support pin  395 . The wire guide  390  further includes a cylindrical first portion  396  connected to an annular flange  398 . The cylindrical first portion  396  is sized to frictionally engage the central bore  334  of the handle  306 . The annular flange  398  has an increased diameter than the first portion  396 .  
     [0071] In this embodiment, the annular flange  398  has an outside diameter, which is substantially equal to the outside diameter of the handle  306 . The spring  352  is positioned to provide the vertical movement to the actuator rod  318  when the button  304  is depressed. As discussed earlier, the button  304 , when pressed, pushes the actuator rod  318  in a downward direction, which in turn, pushes the plug  350  in the same downward direction to eject the nitinol wires  360  out of the prosthetic template  310 .  
     [0072] The plurality of holes  392  are evenly distributed along the periphery on the wire guide  390  in a pre-determined arrangement to receive a plurality of steel tubes  430 . The predetermined arrangement of the holes  392  ensures that the steel tubes  430 , when press fitted in the holes  392 , provide the necessary structural support to the prosthetic template  310 . Each steel tube is guided and press fitted through each hole of the wire guide  390 . The stainless steel tubes  430  (shown in FIG. 8) are partly mounted inside the handle  306  to guide the nitinol wires  360  that are press fitted into the wire retaining plug  350  and partly protruding outside the handle  306  to connect to the prosthetic template  310 . The entire wire guide arrangement  308  is then press fitted into the central bore  334  of the handle and is frictionally in contact with the bottom end  346  of the handle. In one embodiment, the wire guide  390  is formed from a plastic material such as, polypropylene, polycarbonate, or polystyrene.  
     [0073] The support pin  395 , which is cylindrical in shape, is generally rigid and fabricated from the stainless steel material. The support pin  395  includes an upper end  400  and a lower end  402 . The upper end  400  is fixedly attached to the wire guide  390 , while the lower end  402  is fixedly attached into an opening  420  of a support plate  422 . The support plate  422  is star-shaped. In another embodiment, the support plate  422  is generally triangular or any other suitable shape. During the assembly, the support plate  422  is positioned in the center of the prosthetic template  310  to provide the structural support. The details pertaining to the prosthetic template  310  are shown further in FIG. 8.  
     [0074] As shown in FIG. 8, three cusp portions  456 ,  458 ,  460  are connected with each other utilizing three commissure portions  466 ,  468 ,  470  to form the prosthetic template  310 . In the embodiment shown, the three cusp portions  456 ,  458 ,  460  are molded together with three commissure portions  466 ,  468 ,  470  to form a single piece. The prosthetic template  310  further includes a plurality of openings  442  to firmly connect the plurality of stainless steel tubes  430  that are partly protruding out of the wire guide  390 .  
     [0075] The prosthetic template  310  is assembled to the handle  306  utilizing the plurality of steel tubes  430 , the support pin  395  and the support plate  422 . The support plate  422  is mounted within the three cusp portions and is firmly connected to three commissure portions by utilizing a plurality of pins  472  to connect the ends of the support plate  422 . The upper end  400  (as shown in FIG. 7) of the support pin  395  is fixedly attached to the wire guide  390  while the lower end  402  (as shown in FIG. 7) is fixedly attached into the opening  420  of the support plate  422  (as shown in FIG. 7) thereby connecting the support plate  422  to the handle  306 . The support pin  395  is assembled with the wire guide  390  to provide additional support to the prosthetic template  310  around the axis of symmetry  340  of the handle  306 . The template  310  when assembled with the support plate  422  and the support pin  395  provides additional structural support to the prosthetic template  310  around the axis of symmetry  340  of the handle  306 . The template  310  when assembled forms an annular base  482  having an opening  484  therein around an axis of symmetry  340 .  
     [0076] The plurality of nitinol wires  360  that are press fitted into the wire retaining plug  350 , as described above, are positioned within the plurality of stainless steel tubes  430  to provide the marking function. The nitinol wires  360  are ejected out of their respective stainless steel tubes  430  to mark positions on body cavity tissues when the button  304  is firmly pressed by applying pressure on the first end  352 . Once assembled, the button  304 , the handle  306 , the wire arrangement  308 , the prosthetic template  310 , and the actuator rod  318 , all form a common axis of symmetry collinear with the axis of symmetry  340 . In the embodiment shown, nine stainless steel tubes, the support pin  395 , and the support plate  422  are utilized to assemble and firmly hold the prosthetic template  310  to the handle  306 .  
     [0077] In another embodiment, flexible wires made out of materials instead of nitinol may be used. A plurality of flexible wires may be positioned within each respective stainless steel tube in a similar fashion as nitinol wires. The diameter of each respective stainless steel tube is selected to accommodate the number of flexible wires or nitinol wires selected. The prosthetic template  310  simulates the leaflets and commissures of the prosthetic valve. Different numbers of commissure portions, such as two, can be used for a prosthesis with different numbers of cusp portions. The number of steel tubes are selected based on the number of commissure portions of the prosthetic template  310 .  
     [0078]FIG. 9 is a partial cut-away view further showing the assembly of the marking tool  302 . As shown, the button  304  is attached to the actuator rod  318  positioned within the handle  306  by utilizing the threads located on the threaded post  314  at the second end of the button  304 . The actuator rod  318  is positioned at a pre-determined location within the handle  306  utilizing the pin  342 . The pin  342  is fixedly attached to the handle  306  and mounted within the slot  330  of the actuator rod  318  to accommodate the vertical movement of the actuator rod  318  when the button  304  is depressed by the surgeon. As shown and fully described earlier, the wire retaining plug  350 , the spring  352  and the wire guide assembly  308  are positioned within the handle. Connected to the wire guide assembly  308  are the plurality of steel tubes  430 , which are partially protruding from the wire guide  390  and away from the axis of symmetry  340  to connect the prosthetic template  310 . The support pin  395  connected to the wire guide  390  and the support plate  422  are mounted within the prosthetic template  310 , as discussed above, to provide structural support to the template  310 . The prosthetic template  310  generally includes openings  442  at desired locations to accommodate the stainless steel tubes  430 . The stainless steel tubes  430  are utilized to guide the nitinol wires  360  out of openings  442  and mark the tissue when the tool  302  is properly positioned. In the embodiment shown, there are nine different openings  442  on the prosthetic template  310 . The number and location of the openings  442  are selected to leave desired markings within the aorta. The markings at or near the openings  442  approximately outline the position of the prosthesis against the aorta. In an alternative embodiment, the nitinol wires  360  are coated with a dry powder. This is achieved by applying ink having a very volatile thinner that dries out quickly, leaving just the dry powder at a tip of the nitinol wire. In another embodiment, a set of flexible wires are utilized instead of nitinol wires  360 .  
     [0079]FIG. 10 is a partial cut-away view depicting the use and the operation of the marking tool  302 .  
     [0080] The method of marking a location includes lowering the marking tool  302  within a body cavity, positioning the marking tool  302  where the prosthetic device is to be implanted within the body cavity, and pressing a button of the marking tool  302  while firmly holding the marking tool  302  at a desired location to mark positions. The marking of the positions is accomplished by dispensing the marking material in the body cavity tissues, which facilitates a placement of sutures by the surgeon.  
     [0081] The marking function is normally performed by the surgeon following the removal of the damaged natural heart valve and prior to implantation of the prosthetic device. The use of the marking tool improves the consistency of the replacement procedure, decreases the complexity of the attachment and reduces the implantation time. The marking function is performed by pressing the button  304  shown in FIG. 6. Pushing the button  304  in a downward direction pushes the actuator rod  318 , which, in turn, pushes the wire retaining plug  350  (shown in FIG. 7) in a downward direction. The downward movement of the wire retaining plug  350  within the handle  306  ejects the nitinol wires  360  out of the steel tubes  430 . As shown in FIGS. 9 and 10, the steel tubes  430  are connected to the openings  442  of the prosthetic template  310 . The support plate  422  provides counter support against the downward force applied by the handle  306  thereby forcing the nitinol wires  360  out of the tubes  430  to carry the marking material or ink to mark the tissues. The nitinol wires  360  positioned within the steel tubes  430  are ejected when the actuator rod  318  mounted within the handle  306  is depressed by utilizing the button  304 .  
     [0082] It will, of course, be understood that modifications to the present preferred embodiment will be apparent to those skilled in the art. Consequently, the scope of the present invention should not be limited by the particular embodiments discussed above, but should be defined only by the claims set forth below and equivalents thereof.