Patent Publication Number: US-8992598-B2

Title: Biomedical valve devices, support frames for use in such devices, and related methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/842,363, filed on Aug. 21, 2007 and now U.S. Pat. No. 8,257,429, which claims priority to U.S. Provisional Application Ser. No. 60/822,963, filed on Aug. 21, 2006. The entire contents of each of these related applications are hereby incorporated into this disclosure. 
    
    
     FIELD 
     The disclosure relates, generally, to the field of medical devices and associated methods of making medical devices and methods of treating animals, including humans, with medical devices. More particularly, the disclosure relates to valve devices that can be used to affect the flow of fluid through a body vessel. 
     BACKGROUND 
     Many vessels in animal bodies transport fluids from one bodily location to another. Frequently, fluid flows in a unidirectional manner along the length of the vessel. In some vessels, such as mammalian veins, natural valves are positioned along the length of the vessel and act as one-way check valves that open to permit the flow of fluid in the desired direction and close to substantially prevent fluid flow in a reverse direction, i.e., retrograde flow. These natural valves can change between open and closed positions in response to a variety of circumstances, including changes in the cross-sectional shape of the vessel and the fluid pressure within the vessel. 
     While natural valves may function without failure for an extended time, some may lose effectiveness, which can lead to physical manifestations and pathology. For example, venous valves are susceptible to becoming insufficient due to one or more of a variety of factors. For example, vein walls may become stretched or weakened in localized areas, affecting the ability of the valve leaflets within the affected areas to close. Furthermore, natural valve leaflets are relatively fragile and may become damaged, such as by formation of thrombus and scar tissue, which may also affect the ability of the valve leaflets to close. Ultimately, damaged venous valves may lead to venous valve insufficiency, which can produce a variety of clinical manifestations, including swelling of the lower leg, discomfort, and ulcers in the legs and ankles that are difficult to heal. Valve insufficiency patients are often unable to withstand even short periods of standing. 
     Current treatments for venous valve insufficiency include the use of compression stockings that are placed around the leg of a patient in a effort to force the vessel walls radially inward to restore valve function. Surgical techniques can be employed in which valves can be bypassed, repaired, such as by valvuloplasty, or replaced with artificial valves or autogenous sections of veins having competent valves. The art has recently expanded to include prosthetic valves that are implantable by minimally invasive techniques, including catheter-based deployment of self-expandable valve devices. In these devices, a graft member is typically attached to a support frame in a manner that forms some type of valve that is able to selectively open and close in response to various environmental factors, such as changes in fluid pressure, within a body vessel. For example, the graft member can be in the form of one or more leaflets that are attached to a support frame and movable between first and second positions. In a first position, the valve is open and allows fluid flow to proceed through a vessel in a first direction. In a second position, the valve is closed to prevent fluid flow in a second, opposite direction, i.e., retrograde flow. Examples of this type of prosthetic valve are described in commonly owned U.S. Pat. No. 6,508,833 to Pavcnik for a MULTIPLE-SIDED INTRALUMINAL MEDICAL DEVICE, United States Patent Application Publication No. 2001/0039450 to Pavcnik for an IMPLANTABLE VASCULAR DEVICE, and U.S. patent application Ser. No. 10/642,372, filed on Aug. 15, 2003, each of which is hereby incorporated by reference in its entirety. 
     The use of autogenous tissue in a valve device has the advantage of avoiding some materials-based concerns that must be taken into consideration when developing a prosthetic valve that includes a graft member formed of non-autogenous materials, such as non-natural materials and natural, non-autogenous materials. To date, however, many artisans believed that the drawbacks of using autogenous tissue in a valve device outweighed the benefits. For example, the use of autogenous tissue requires additional procedures in a treatment regimen, including harvesting of the tissue and fashioning of the tissue into a useable valve device, that many believe are too time-consuming and complicated to form the basis of a dependable treatment regimen. 
     As a result, there remains a need in the art for improvements relating to autogenous biomedical valves and related methods. 
     SUMMARY OF EXEMPLARY EMBODIMENTS 
     The invention provides biomedical valve devices that are suitable for use in treating a variety of conditions, including venous disease. Support frames that provide a scaffolding onto which a tissue valve and/or tissue can be attached to form a biomedical valve device are described. A preexisting tissue valve can be placed on the support frame or a non-valve tissue can be placed on the support frame in a manner to form a valve. 
     A support frame according to a first exemplary embodiment comprises first and second interconnected frame members. The first frame member defines a first closed circumference and has a first axial length. The second frame member defines a second closed circumference and a second axial length. The second closed circumference is smaller than the first closed circumference and the second axial length is shorter than the first axial length. The first and second frame members are joined at proximal base portions and substantially free of each other at distal apical portions. 
     In one exemplary embodiment, the second frame member includes a plurality of arms, each of which includes a base portion and an upper portion separated by an angle. In another exemplary embodiment, the second frame member includes a lower portion that joins two or more arms. 
     Biomedical valve devices are also described. Valve devices according to exemplary embodiments include a support frame according to the invention and a tissue valve attached to the support frame. Valve devices according to other exemplary embodiments include a support frame according to the invention and a tissue attached to the support frame in a manner to form a valve. Exemplary embodiments include a native venous valve attached to a support frame according to the invention. Another exemplary embodiment comprises a section of an body vessel, such as a vein, attached to a support frame according to the invention. Attachment of a tissue valve or a tissue to form a valve can be accomplished using sutures or other suitable fasteners. Exemplary embodiments include a tissue valve or a tissue attached to a support frame according to the invention using barbs associated with the support frame, either in conjunction with or in the absence of other means for attaching the tissue valve or tissue to the support frame. 
     Methods of making biomedical valve devices are also described. An exemplary method comprises the steps of providing a support frame according to the invention and providing a tissue valve. Another step comprises attaching the tissue valve to the support frame. In one exemplary method, the tissue valve comprises a native venous valve. In another exemplary embodiment, the tissue valve comprises a venous valve harvested from the same patient into which the biomedical valve device is intended to be implanted. In this embodiment, the biomedical valve device comprises an autogenous biomedical valve device. In alternative embodiments, a tissue, such as a portion of a body vessel, is attached to the support frame in a manner to form a valve. 
     Methods of treating animals, including human and non-human animals alike, for valve-related conditions are also described. A exemplary method comprises the steps of harvesting a tissue valve from the patient and providing a support frame according to the invention. Another step comprises forming an autogenous biomedical valve device by attaching the tissue valve to the support frame. Any suitable method of forming a biomedical valve device according to the invention can be used for this step. Another step comprises loading the biomedical valve device into a suitable delivery system. Another step comprises advancing the biomedical valve device, loaded on the delivery system, to a point of treatment within a body vessel. Another step comprises deploying the biomedical valve device using a technique appropriate for the selected delivery system. Another step comprises withdrawing the delivery step from the body vessel. In alternative embodiments, a tissue, such as a portion of a body vessel, is harvested from the patient and attached to the support frame in a manner to form a valve. 
     Additional understanding of the invention can be obtained with review of the detailed description of exemplary embodiments, below, and the appended drawings illustrating various exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of a support frame according to a first exemplary embodiment shown in a flattened configuration. 
         FIG. 2  is a side view of the support frame of  FIG. 1  shown in a second configuration. 
         FIG. 3  is an illustration of a support frame according to a second exemplary embodiment shown in a flattened configuration. 
         FIG. 4  is a side view of the support frame of  FIG. 3  shown in a second configuration. 
         FIG. 5  is a side view of a biomedical valve device that includes the support frame of  FIGS. 3 and 4 . 
         FIG. 6  is a side view of a support frame according to a third exemplary embodiment. 
         FIG. 7  is a side view of a biomedical valve device that includes the support frame of  FIG. 6 . 
         FIG. 8  is an illustration of a support frame according to a fourth exemplary embodiment shown in a flattened configuration. 
         FIG. 9  is a side view of the support frame of  FIG. 8  shown in a second configuration. 
         FIG. 10  is a second side view of the support frame of  FIG. 8  shown in the second configuration. 
         FIG. 11  is a side view of a support frame according to a fifth exemplary embodiment. 
         FIG. 12  is a side view of a biomedical valve device that includes the support frame of  FIG. 11 . 
         FIG. 13  is a side view of a support frame according to a sixth exemplary embodiment. 
         FIG. 14  is a second side view of the support frame illustrated in  FIG. 13 . 
         FIG. 15  is a flowchart illustrating an exemplary method of making an autogenous biomedical valve. 
         FIG. 16  is a flowchart illustrating an exemplary method of treating an animal for a valve-related condition. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following detailed description and the appended drawings describe and illustrate exemplary embodiments of the invention solely for the purpose of enabling one of ordinary skill in the relevant art to make and use the invention. As such, the description and illustration of these embodiments are purely exemplary in nature and are in no way intended to limit the scope of the invention, or its protection, in any manner. 
       FIGS. 1 and 2  illustrate a support frame  10  according to a first exemplary embodiment. The support frame comprises first  12  and second  14  interconnected frame members. In this embodiment, each of the frame members  12 ,  14  comprises a wire member formed into a closed circumference from a single piece of material. The closed circumference  16  defined by the first frame member  12  has an overall length that is greater than the overall length of the closed circumference  18  defined by the second frame member  14 . As such, the second frame member  14  is essentially disposed within the closed circumference  16  of the first frame member  12  when the support frame  10  is in a flattened configuration, such as the view illustrated in  FIG. 1 . 
     In the illustrated embodiment, each of the frame members  12 ,  14  comprises a simple wire frame support, which is described in detail in U.S. Pat. No. 6,508,833 to Pavcnik et al. for a MULTIPLE-SIDED INTRALUMINAL MEDICAL DEVICE, the entire contents of which is hereby incorporated by reference for the purpose of describing suitable frame members for use in support frames according to the invention. 
     The first frame member  12  comprises apical bends  20 ,  22  and lateral bends  24 ,  26 . The second frame member  14  comprises apical bends  28 ,  30  and lateral bends  32 ,  34 . The first frame member  12  includes a coil  36  at each bend  20 ,  22 ,  24 ,  26 . The presence of coils enhances the flexibility of the support frame  10  and can provide a point for anchoring tissue or other material to the frame  10 . The second frame member  14  includes coils  38  at apical bends  28 ,  30 . Coils can also be included at lateral bends  32 ,  34  or, as in the illustrated embodiment, these coils can be eliminated. 
     Barbs can be included at various locations to facilitate anchoring of the support frame  10  in a body vessel and/or attachment of tissue or other material to the frame  10 . The illustrated embodiment includes apical barbs  40 ,  42  disposed on opposing struts of the first frame member  12 . Lateral barbs  44 ,  46 ,  48 ,  50  can be disposed near the lateral bends  24 ,  26  of the first frame member  12  and/or the lateral bends  32 ,  34  of the second frame member  14 . As best illustrated in  FIG. 1 , these barbs  44 ,  46 ,  48 ,  50  can be formed by cutting the second frame member  14  at the lateral bends  32 ,  34 . It is noted, though, that separately attached members can also be used to form lateral barbs. 
     As best illustrated in  FIG. 1 , the support frame  10  according to the first exemplary embodiment is formed simply by interconnecting the first  12  and second  14  frame members. Various cannulae  52  disposed at various locations can be used to join the frame members  12 ,  14 . In the illustrated embodiment, cannulae  52  are disposed near each of the lateral bends  24 ,  26 ,  32 ,  34 . Each cannulae receives a portion of each frame member  12 ,  14  and is crimped, welded, soldered or otherwise fixed to form a connection between the members  12 ,  14 . While cannulae are illustrated as a means for connecting the first  12  and second  14  frame members, it is expressly understood that any suitable means for connecting members together can be used, including adhesives, direct soldering of the first frame member  12  to the second frame member  14 , and other suitable means for connecting. Cannulae  52  or other suitable means for connecting are also used to join ends of a wire or other material used to form each of the frame members  12 ,  14 . Joining of blunt ends of a wire or other material can also be used. 
     The support frame  10  is placed in a second configuration, illustrated in  FIG. 2 , by advancing a apical bends  20 ,  22  of the first frame member  12  toward each other, which results in apical bends  28 ,  30  of the second frame member  14  being similarly advanced toward each other. This transformation is represented by arrow  60  in  FIG. 1 . The resulting second configuration is illustrated in  FIG. 2 . The second configuration substantially represents the form the support frame  10  would take within a body vessel following deployment. It is the configuration the support frame  10  would be in prior to loading in a delivery system to effect such deployment in a body vessel, as will be described in detail below. Immediately prior to loading into a delivery system, the support frame, along with any attached tissue valve or tissue fashioned into a valve, the support frame can be compressed into a low-profile configuration suitable for placement within the selected delivery system. 
     When deployed in a lumen of a vessel, the support frame  10  in the second configuration exerts a radially outward force on the interior wall of the vessel. The bending stresses introduced to the frame  10  by the folding required to form the second configuration apply force radially outward against the vessel wall to hold the frame in place and prevent vessel closure. Absent any significant plastic deformation occurring during folding and deployment, the second configuration, when not in the vessel or subject to other constraining means, will at least partially return to the first configuration illustrated in  FIG. 1 , although some deformation can occur depending on the material used. It is also possible to plastically deform the frame  10  into the second configuration, such that it does not unfold when restraint is removed. This might be particularly desirable if the device is made from nitinol or a superelastic alloy. 
     As best illustrated in  FIG. 2 , the support frame  10  includes vessel  70  and valve  72  support portions. The vessel support portion  70  is defined by the circumference  16  of the first frame member  12  when the support frame  10  is in the second configuration. Similarly, the valve support portion  72  is defined by the circumference  18  of the second frame member  14  when the support frame  10  is in the second configuration. Because the circumference  16  of the first frame member  12  is greater than the circumference  18  of the second frame member  14 , the vessel support portion  70  has an axial length  80  that is greater than the axial length  82  of the valve support portion  72 , as measured from a hypothetical line  84  that connects lateral bends  24 ,  26  of the first frame member  12  when the support frame  10  is in the second configuration. In use, the vessel support portion  70  provides support to the portion of the vessel in which the support frame  10  is implanted and the valve support portion  72  provides a structure onto which a tissue valve or other tissue can be attached to form a biomedical valve device, as will be described in more detail below. This structural and spatial relationship between the vessel  70  and valve  72  support portions ensures that a valve disposed or formed on the valve support portion  72  is positioned within an area of a body vessel that is supported by the vessel support portion  70  when a biomedical valve that incorporates the support frame  10  is implanted in a body vessel. This is believed to be advantageous at least because it provides a separation between the vessel wall and the valve. 
     The support frame  10  is made of resilient material, preferably metal wire formed from stainless steel or a superelastic alloy, such as nitinol. Other materials, such as polymeric and resorbable materials, can also be used. Indeed, any suitable material can be used to form a support frame according to the invention. The material chosen for a specific support frame according to a particular embodiment need be capable of providing the desired support to the vessel and to the valve. The material should be biocompatible or be capable of being rendered biocompatible. The support frame  10  and/or the individual frame members  12 ,  14  could also be formed by punching, cutting or otherwise forming the item from a solid piece of material. For example, the support frame  10  could be laser cut from a nitinol tube, as is known in the art. 
     Certain features of the support frame can be modified and/or optimized based upon the characteristics of the selected material. For example, instead of using coils, such as coils  36  and  38  of the embodiment illustrated in  FIGS. 1 and 2 , a simple bend, such as a substantially orthogonal bend, may be more appropriate if the frame is formed of nitinol or another superelastic alloy because the formation of certain types of bends, such as coils, may actually decrease fatigue life of a superelastic material. Other alternative bend structures, including outward-projecting fillets and inward-projecting fillets comprising a series of curves, can be used and may be appropriate for certain types of materials. Fillets are well known in the stent art as a means for reducing stresses in bends. In any particular embodiment, the specific structure chosen for bends in the frame members  12 ,  14  should be one that minimizes bending fatigue for the material of which the support frame  10  is formed. If this construction is used, certain features of the illustrated embodiment, such as the various coils, may not be necessary. 
     While round wire is depicted in the figures, other types, such as wire having flat, square, triangular, D-shaped, trapezoidal, and delta-shaped cross-sectional profiles may be used to form the frame  10 . Indeed, wire having any suitable cross-sectional shape can be used. Furthermore, while each of the first  12  and second  14  frame members of the support frame  10  illustrated in  FIGS. 1 and 2  have four sides of approximately equal length, it is expressly understood that frames with sides of different lengths and frames of any polygonal shape, such as pentagons hexagon, and octagon shapes, can also be used. 
     The cross-sectional diameter of the wire selected will depend on the size of the medical device and the application. Wire that is too stiff can damage the vessel, not conform well to the vessel wall, and increase the profile of the device when loaded in a delivery system prior to deployment. Wire that is not sufficiently stiff may not allow a valve disposed or formed on the valve support portion  72  to function as desired. An appropriate diameter can be selected by those skilled in the art based on various considerations, including the desired profile of a delivery system into which a biomedical valve device incorporating the support frame  10  will be loaded, the vessel within which the device is intended to be used, and the type of tissue valve and/or tissue that will be attached to the support frame  10  during use. It is expressly understood and appreciated that material of different diameters could be used for different portions of the support frame. For example, the first frame member  12  could be formed of wire having a first diameter and the second frame member  14  could be formed of wire having a second, different diameter. This may be advantageous if different support characteristics are desired for the vessel  70  and valve  72  support portions. It is also expressly understood and appreciated that material that has a varying diameter over its length could be used to form the support frame  10  or portions of the support frame  10 . For example, one or both frame members  12 ,  14  could be formed of a wire that has a first diameter along portions of its length and a second, different diameter along other portions of its length. This construction could be used to place wire with a larger diameter in portions of a frame member  12 ,  14  that would benefit from such placement, such as the various apical and/or lateral bends. 
       FIGS. 3 and 4  illustrate a support frame  110  according to a second exemplary embodiment. The support frame  110  is similar to the support frame  10  illustrated in  FIGS. 1 and 2 , except as described below. Accordingly, the support frame  110  includes first  112  and second  114  support frames that define first  116  and second  118  closed circumferences. A vessel support portion  170  is defined by the closed circumference  116  of the first support frame  112  and a valve support portion  172  is defined by the closed circumference  118  of the second support frame  114 . 
     In this embodiment, each arm  190  of the second support frame  114  defines an angle  192  to form base  194  and upper  196  portions of the frame member  114 . As best illustrated in  FIG. 4 , which illustrates the support frame  110  in the second configuration, the base portion  194  is a relatively wide portion of the second frame member  114  that extends inward at a first angle relative to a lengthwise axis  198  of the support frame  110 . The upper portion  196 , in contrast, is relatively narrow and extends inward at a second angle relative to a lengthwise axis  198  of the support frame  110 . The second angle is smaller than the first angle. That is, the upper portion  198  of the second frame member  114  extends closer to parallel to the lengthwise axis  198  than the base portion  194 . As described below, when a valve is attached to or formed on the valve support portion  172 , upper portions of the valve are placed further from the vessel wall than portions adjacent the base portion  194  of the second frame member  114 . This is believed to be advantageous at least because the movable portion of the valve, i.e., the portion that defines the valve orifice, is spaced from the vessel wall when implanted in a body vessel. 
     Any suitable angle can be used for the angle  192 . Furthermore, a curvilinear portion can be used in place of a distinct angle. For a specific support frame according to an embodiment of the invention, a skilled artisan can choose a suitable angle based on various considerations, including the desired coaptation length for the valve portion of a valve attached to or formed on the second frame member  114 , the desired depth of the valve pockets, and the nature of the vessel wall and the tissue valve or tissue attached to the second frame member  114 . It is expressly understood and appreciated that a support frame according to the invention can include a second frame member that has two or more different angles formed on the arms. The use of different angles may be desirable, for example, if a support frame is being used in a biomedical valve designed for use in a body vessel or other location that is not expected to have a uniform inner diameter or that is expected to have differential wall characteristics. 
       FIG. 5  illustrates a biomedical valve  100  that includes the support frame  110  illustrated in  FIGS. 3 and 4 . A tissue valve  102  is attached to the valve support portion  172  formed by the second support frame  114 . The tissue valve  102  includes first  104  and second  106  valve leaflets that cooperatively define a valve orifice  108  that is able to open and close to permit and substantially prevent, respectively, fluid flow through the body vessel into which the biomedical valve  100  is intended to be implanted. As will be described in greater detail below, the tissue valve  102  in this embodiment is an autogenous valve harvested from a different body vessel than the vessel into which the biomedical valve  100  is intended to be implanted. In an alternative embodiment, a valve is formed on the valve support portion  172  by attaching a tissue or portion thereof to the valve support portion in a manner that fashions the attached tissue into a valve. That is, the tissue is attached in a manner defines functional valve that is able to selectively allow and substantially prevent fluid flow through the body vessel. Formation of a valve orifice by two or more valve leaflets, similar to the biomedical valve  100  illustrated in  FIG. 5 , is an exemplary alternative embodiment. 
     Any suitable tissue can be used to form a valve of the support frame. The tissue selected for a biomedical valve device according to a particular embodiment of the invention need only be capable of being attached to the support frame in a manner that forms the desired valve configuration. The tissue should be selected to provide desirable behavior of the valve following deployment of the biomedical valve device in a body vessel. Examples of suitable tissues include pleura, such as a lining from the peritoneal cavity, a tissue capsule, such as a renal capsule, and a vessel wall or portion thereof. The use of tissues other than vessel walls might be particularly advantageous when fashioning a biomedical valve device according to an embodiment of the invention that is intended to be implanted in a patient that is missing a particular body vessel or has a damaged portion of a particular body vessel. For example, in humans that have already lost a greater saphenous or other donor vessel, use of a renal capsule or other tissue might be advantageous. 
     The tissue valve  102  is attached to the second frame member  114  with sutures placed at various positions along the length of the second frame member  114 . In this embodiment, sutures  111  placed at the coils  138  disposed at apical bends  128 ,  130  provide a suitable attachment for the tissue valve adjacent the valve orifice  108 . Other suitable means for attaching a tissue valve and/or a tissue to a support frame can be used, of course, including clips, staples, adhesives, tissue welding materials and techniques, and other suitable means for attaching. It will be readily appreciated that the presence of coils  138  at the apical bends  128 ,  130  of the second frame member  114  is believed to be particularly advantageous at least because, as described above, they provide a mechanism for relieving stress introduced into the support frame  110  by forming the second configuration, and also because they provide a point for securing a tissue valve and/or a tissue to the valve support portion  172 . 
     As will be described in more detail below, biomedical valve devices according to the invention are formed by attaching a tissue valve or a tissue to a support frame. This can be conducted as part of a treatment regimen in which an autogenous tissue valve or tissue is harvested from a patient and immediately attached to an appropriate support frame to form an autogenous biomedical valve. In these methods, it is desirable to conduct the attachment step as quickly as possible to minimize the time during which the harvested tissue valve or tissue is outside of its natural environment. 
       FIG. 6  illustrates a support frame  210  that includes adaptations that are believed to facilitate attachment of a tissue valve or tissue to the support frame in a relatively quick manner. The support frame  210  according to this exemplary embodiment is similar to the support frame  110  illustrated in  FIGS. 3 and 4 , except as described below. Accordingly, the support frame  210  includes first  212  and second  214  support frames that define first  216  and second  218  closed circumferences. A vessel support portion  270  is defined by the closed circumference  216  of the first support frame  212  and a valve support portion  272  is defined by the closed circumference  218  of the second support frame  214 . 
     In this embodiment, the second frame member  214  includes barbs  240  disposed at the apical bends  228 ,  230 , in addition to the barbs  244 ,  246 ,  248 ,  250  disposed at lateral bends  232 ,  234 . The positioning of barbs at the apical  228 ,  230  and lateral  232 ,  234  bends of the first frame member provide attachment points that allow for relatively quick securement of a tissue valve and/or tissue to the valve support portion  272  during a treatment procedure. A user need only pierce the barbs  244 ,  246 ,  248 ,  250  through the tissue valve and/or tissue to form a biomedical valve device, such as the valve device  200  illustrated in  FIG. 7 . These adaptations of the support frame  210  are expected to significantly facilitate the use of the support frame as a scaffold for forming biomedical valve devices and to address some of the concerns associated with using autogenous valves in the treatment of various valve disorders, namely, the concern that such an approach necessarily requires time-consuming and complicated valve formation steps. 
     It is expressly understood and appreciated that sutures and/or other suitable means for attaching a tissue valve and/or tissue to the support frame  210  can be used in addition to the barbs  240 ,  244 ,  246 ,  248 ,  250 . For example, it may be advantageous to include a suture or other means for attaching at an interior point along the length of the second frame member  114 , such as at or near the angle  292 . 
       FIGS. 8 through 10  illustrate a support frame  310  according to another exemplary embodiment. The support frame comprises a first frame member  312  and two secondary frame members  314   a ,  314   b . The first frame member  312  is similar to the first frame member described above in connection with other exemplary embodiments in that it defines a closed circumference  316 . The secondary frame members  314   a ,  314   b , however, do not define a single closed circumference by themselves. Rather, in this embodiment, the secondary frame members  314   a ,  314  beach provide a base  394  and upper  396  portion onto which a tissue valve and/or tissue can be attached to form a biomedical valve device. 
     In contrast to the second frame members of the embodiments described above, the secondary frame members  314   a ,  314   b  of this embodiment are positioned substantially orthogonally to a lateral axis  313  of the first frame member  312 . This relative positioning is believed to be advantageous at least because it makes it relatively easier to attach a tissue valve and/or tissue to the tissue support portion during formation of a biomedical valve device, which may reduce the time required for an attachment step during formation of an autogenous valve device. As described above, this reduction in time might prove important to the acceptance of the use of autogenous biomedical valve devices in the treatment of valve conditions, such as venous insufficiency. Furthermore, this relative positioning of the first frame member  312  and the secondary frame members  314   a ,  314   b  places the valve orifice of a biomedical valve device that includes the support frame  310  at an angle with respect to a lateral axis of the first frame member  312 , such as the lateral axis  313  extending between apical bends  320 ,  322  of the vessel support portion  370 . This positioning is also believed to be advantageous at least because, upon implantation of the biomedical valve device in a body vessel, it is expected to place the valve orifice within a sinus formed in the body vessel due to outwardly directed radial force placed on the vessel wall by the vessel support portion  370 . This placement in a formed sinus may facilitate opening and closing of the valve orifice and flushing of the valve pockets. This positioning is best illustrated in  FIG. 10 . 
     It is expressly understood and appreciated that the support frame  310  can be modified to include barbs at various locations to facilitate attachment of a tissue valve and/or tissue to form a biomedical valve device, such as at the apical bends  328 ,  330  of the secondary frame members  314   a ,  314   b , similar to the modifications described above and illustrated in  FIGS. 6 and 7 . 
       FIG. 11  illustrates a support frame  410  according to another exemplary embodiment. The support frame  410  is similar to the support frame  110  described above and illustrated in  FIG. 4 , except as detailed below. Accordingly, the support frame  410  includes a first frame member  412  that defines a first closed circumference  416 . Secondary frame members  414   a ,  414   b  are connected to the first frame member  412  and define secondary closed circumferences  418   a ,  418   b . Each of the secondary frame members  414   a ,  414   b  includes a base  494 , an upper portion  496 , and a lower portion  498 . When used in a biomedical valve device, such as the device  400  illustrated in  FIG. 12 , a tissue valve  402  or tissue is attached to a valve support portion  472  defined by the base  494  and upper  496  portions of the secondary frame members  414   a ,  414   b . The lower portions  498  of the secondary frame members  414   a ,  414   b  remain substantially free of the tissue valve  402  and/or tissue, as best illustrated in  FIG. 12 . As such, the lower portions  498  provide a means for providing additional support to the body vessel at the site at which the biomedical valve device is implanted. 
     The support frame  410  illustrated in  FIG. 11  is readily formed by interconnected a first wire form member with second and third wire form members. The first wire form member is formed into the first frame member  412  and the second and third wire form members are individually formed into the secondary frame members  414   a ,  414   b . Connections can be formed using suitable techniques and means for connecting, including cannulae, as described above. 
       FIGS. 13 and 14  illustrate a support frame  510  according to another exemplary embodiment. The support frame  510  is similar to the support frame  310  described above and illustrated in  FIGS. 8 through 10 , except as detailed below. Furthermore, the support frame  510  includes a modification similar to the modification made to the support frame  410  illustrated in  FIG. 11 . That is, the support frame  510  includes a first frame member  512  that defines a first closed circumference  516  and secondary frame members  514   a ,  514   b  that define secondary closed circumferences  518   a ,  518   b . Each of the secondary frame members  514   a ,  514   b  includes a base  594 , an upper portion  596 , and a lower portion  598 . When used in a biomedical valve device, a tissue valve or tissue is attached to a valve support portion  572  defined by the base  594  and upper  596  portions of the secondary frame members  514   a ,  514   b . The lower portions  598  of the secondary frame members  514   a ,  514   b  remain substantially free of the tissue valve and/or tissue. As such, the lower portions  598  provide a means for providing additional support to the body vessel at the site at which the biomedical valve device is implanted. 
     The support frame  510  according to this embodiment is readily formed in a similar manner to the support frame  410  illustrated in  FIG. 11  and described above. The support frame  510  can be formed by interconnecting a first wire form member with second and third wire form members. The first wire form member is formed into the first frame member  512  and the second and third wire form members are individually formed into the secondary frame members  514   a ,  514   b . Connections can be formed using suitable techniques and means for connecting, including cannulae, as described above. 
     It is expressly understood and appreciated that any feature or component of any embodiment described herein can be combined with any other embodiment of the invention even though the subject feature or component is not specifically described in connection with such embodiment. For example, the barb adaptations  240  on the second support frame  214  can be used in connection with any embodiment of the invention. The use of these adaptions on a second support frame, or on secondary support frames such as those illustrated in  FIGS. 8 through 14  and described above, are believed to be advantageous at least because they facilitate the attachment of a tissue valve and or tissue to the support frame, thereby facilitating the formation of a biomedical valve device. 
     Furthermore, it is expressly understood and appreciated that, while the support frames described herein are particularly well-suited for use in biomedical valve devices, these apparatuses may find other utility in the medical arts or even in other arts. For example, a support frame according to an embodiment of the invention could likely be adapted to be used as a stent, as an occluder, or as an intravascular filter. Taken alone, the support frames described herein could provide a stenting function to a body vessel. Occluders and filters, among other devices, could be made by adding appropriate functionality to the base support frame, such as an appropriate graft material or wire members. Nothing in this disclosure is intended to limit the scope of the described support frames to the biomedical valves application. 
     The support frame described herein are particularly well suited for use in biomedical valve devices. A biomedical valve device can be formed by attaching a tissue valve to a valve support portion of a support frame according to the invention using any suitable means for attaching a tissue valve to a support frame, including sutures, barbs, a combination of sutures and barbs, clamps, adhesives, and any other suitable means for attaching. Alternatively, a biomedical valve device can be formed by attaching a tissue, such as a portion of a body vessel, to at least a valve support portion of a support frame according to an embodiment of the invention in a manner that forms a valve capable of permitting flow through a body vessel in a first direction and substantially preventing fluid flow through a body vessel in a second, opposite direction. Tissues can be attached to a valve support portion of a support frame according to the invention using any suitable means for attaching tissue to a support frame, including sutures, barbs, a combination of sutures and barbs, clamps, adhesives, and any other suitable means for attaching. The inventor has determined that barbs, either alone or in combination with another means for attaching, such as sutures, are particularly advantageous when a portion of a body vessel, such as a vein, is used as a tissue in a biomedical valve device according to an embodiment of the invention. The vessel provides a relatively thick material that is able to be pierced by barbs without risking compromise to the tissue and the function of the valve formed by the tissue. As described above, the use of barbs, either alone or in combination with other suitable means for attaching, such as sutures, facilitates the formation of the biomedical valve device, which can be particularly advantageous when the formation is part of a time sensitive procedure, such as formation of an autogenous biomedical valve device. 
     Methods of making biomedical valve devices are provided. An exemplary method comprises the steps of providing a support frame according to the invention and providing a tissue valve. Another step comprises attaching the tissue valve to the support frame as described above. In one exemplary embodiment, the tissue valve comprises a venous valve. In another exemplary embodiment, the tissue valve comprises a venous valve harvested from the same patient into which the biomedical valve device is intended to be implanted. In this embodiment, the biomedical valve device comprises an autogenous biomedical valve device. 
     An alternative method of making a biomedical valve device comprises the steps of providing a support frame according to the invention and providing a tissue. Another step comprises attaching the tissue valve to the support frame as described above. In one exemplary embodiment, the tissue comprises a portion of a body vessel. In another exemplary embodiment, the tissue comprises a portion of a vein. In another exemplary embodiment, the tissue comprises a portion of a vein harvested from the same patient into which the biomedical valve device is intended to be implanted. In this embodiment, the biomedical valve device comprises an autogenous biomedical valve device. 
     In another exemplary embodiment, the tissue comprises a portion of a vessel that includes a native valve. The vessel is attached to the support frame in an inverted orientation, placing the valve on the exterior of the support frame. Another portion of the tissue is fashioned into a valve. When deployed in a body vessel, the native valve is diposed adjacent the interior vessel wall. This is believed to be advantageous at least because it offers a simple fabrication process. Furthermore, the presence of the native valve adjacent the vessel wall following deployment may enhance anchoring of the biomedical valve device within the body vessel. 
       FIG. 15  illustrates an exemplary method  600  of making an autogenous biomedical valve device according to the invention. An initial step  602  comprises establishing access to a donor vessel. For this exemplary method and step, the term “donor vessel” refers to a body vessel of the same patient into which the autogenous biomedical valve device is intended to be implanted. Any suitable vessel can be used. This exemplary method makes use of a preexisting natural valve, so the vessel should be selected to include such a valve. A suitable vein is appropriate. Jugular veins have been used in animal studies. 
     Another step  604  comprises excluding a portion of the donor vessel from fluid flow through the vessel. This can be accomplished by tying or clamping off a portion of the donor vessel as is known in the art. Another step  606  comprises excising a portion of the donor vessel from the patient. For this exemplary method, the portion is selected to include a native tissue valve, such as a native venous valve. The remaining vessel is advantageously tied, clamped or otherwise sealed off to prevent unintended leakage of fluid following removal of the portion to be used for forming the autogenous biomedical valve device. Following removal of the portion of the body vessel that includes the tissue valve, the portion is advantageously kept hydrated with fluid from the vessel or an appropriate tissue preservation fluid, such as University of Wisconsin solution known in the art. The portion is advantageously kept tied, clamped, or otherwise sealed until later in the method, as described below. 
     Another step  608  comprises providing a support frame according to the invention. Any suitable support frame according to the invention can be used in the method, and the specific support frame selected for a particular method according to the invention will depend on several considerations, including the nature of the tissue valve and donor vessel being used and the nature of the body vessel into which the autogenous biomedical valve device will be implanted. 
     Another step  610  comprises placing the portion of the donor vessel within the interior of the support frame such that the tissue valve is substantially adjacent the valve support portion of the support frame. Another step  612  comprises cutting away a portion of the body vessel portion to expose the tissue valve. Another step  614  comprises attaching the tissue valve to the valve support portion of the support frame. In this step, any suitable means for attaching the tissue valve to the support frame can be used, including sutures, clamps, and other suitable means for attaching. The inventor has determined that the use of barbs formed on the tissue support portion of the support frame, with or without other means for attaching the tissue valve to the support frame, provides significant advantage in that barbs provide a relatively quick and secure way to attach the tissue valve to the support frame, significantly reducing complexity and time involved in the formation of the autogenous biomedical valve device. 
     An optional step  616  comprises cutting away the vessel wall to leave substantially only the tissue valve attached to the support frame. An alternative to this optional step comprises securing one or more portions of the vessel wall to a portion of the support frame, such as the vessel support portion. 
     In one alternative method, the step of placing the portion of the donor vessel within the interior of the support frame is eliminated. Instead, a step according to this method comprises placing the support frame within the lumen of the body vessel such that the tissue valve is substantially adjacent the valve support portion of the support frame. This can be accomplished by opening one end of the portion of the body vessel that includes the tissue valve and advancing the support frame into the lumen of the portion. Positioning of the tissue valve can be verified by shining a light directly on the body vessel and observing the support frame position through the vessel wall. Observation can be enhanced by applying pressure, such as with a finger, to effectively compress or thin the vessel wall under the light source. 
     Methods of treating animals for valve-related conditions are also provided. Biomedical valve devices according to the invention are particularly well-suited for treating a variety of valve-related conditions, including venous insufficiency and heart valve conditions. The support frame according to the invention provide a scaffold onto which a valve can be attached or formed, and enable the use of percutaneous delivery techniques to deploy the biomedical valve devices with a body vessel of an animal, including humans. The use of autogenous biomedical valve devices in methods according to the invention are considered particularly advantageous because they significantly reduce various materials-related issues associated with implanting a biomedical valve device within a body vessel. 
       FIG. 16  illustrates one exemplary method  700  of treating an animal, such as a human, for venous insufficiency. An initial step  702  comprises harvesting a tissue valve from the patient. Another step  704  comprises providing a support frame according to the invention. Another step  706  comprises forming an autogenous biomedical valve device by attaching the tissue valve to the support frame. Any suitable method of forming a biomedical valve device according to the invention can be used for this step. 
     Another step  708  comprises loading the biomedical valve device into a delivery system. Any suitable delivery system can be used and the specific delivery system selected for a particular method will depend on several considerations, including the nature of the tissue valve, the overall profile of the biomedical valve device, and the nature of the vessel into which the biomedical valve device is intended to be implanted. Those skilled in the art will be able to readily identify a suitable delivery system for use in the method. Examples of suitable delivery systems are described in International application PCT/US05/30861, entitled DELIVERY SYSTEM WHICH FACILITATES HYDRATION OF AN INTRALUMINAL MEDICAL DEVICE, the entire disclosure of which is incorporated into this disclosure in its entirety for the purpose of describing suitable delivery systems for use with the support frames and biomedical valve devices described herein. 
     Another step  710  comprises advancing the biomedical valve device, loaded on the delivery system, to a point of treatment within a body vessel. Another step  712  comprises deploying the biomedical valve device using a technique appropriate for the selected delivery system. Another step  714  comprises withdrawing the delivery step from the body vessel. 
     An alternative method of treating an animal includes an initial step of implanting a support frame according to the invention in a body vessel adjacent a natural valve. Next, the support frame is kept in the body vessel for a period of time sufficient in length to allow the support frame to become sufficiently integrated into at least a portion of the thickness of the vessel wall at the point of implantation. The support frame is advantageously allowed to become sufficiently integrated into the wall thickness such that the support frame fully supports the natural valve upon excision of the portion of the vessel that contains the valve. An period of approximately 14 days is considered appropriate when sheep valves are used, although any suitable time period can be used. 
     Following the passage of the sufficient time period, the portion of the body vessel that contains the support frame and natural valve is harvested. Then, the support frame/natural valve combination, which can be referred to as a valve device, is loaded into an appropriate delivery system and implanted at a desired point of treatment, such as at a fixed distance from a natural valve shown to be or suspected of being incompetent, or adjacent a natural valve shown to be or suspected to be incompetent. 
     Optional steps in this exemplary method include inspecting the valve device for ruggedness or other desired property; alteration of the valve device following the harvesting step, such as by securing the valve and/or a portion of the vessel to the support frame using a suitable means of securement. Also, a step of hydrating the valve device following harvesting and prior to loading in the delivery system and/or prior to implanting at the treatment site. 
     Implantation can also be accomplished surgically, in which case the loading step can be eliminated. 
     The initial implantation step can be performed in the same animal, including a human patient, as the animal in which the valve device is ultimately implanted. Alternatively, a different animal, and indeed a different species, can be used. For example, the initial implantation step can be performed in a sheep, and the valve device implantation step can be performed in a human patient. In this case, a sheep valve is implanted in a human patient. In any method in which different animals and/or species are used in the two implantation steps, standard tissue grafting considerations should be evaluated and addressed. 
     The foregoing detailed description provides exemplary embodiments of the invention and includes the best mode for practicing the invention. The description and illustration of embodiments is intended only to provide examples of the invention and not to limit the scope of the invention, or its protection, in any manner.