Abstract:
A device for holding an implantable medical device includes a jar for receiving the implantable medical device, and a ring coupleable to the jar. The ring has a plurality of channels adapted to receive retaining features of the implantable medical device to stabilize the medical device within the jar.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/713,213 filed Oct. 12, 2012, the disclosure of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to heart valve replacement and, in particular, to heart valve loading and storage. More particularly, the present invention relates to devices and methods for holding, transferring and deploying prosthetic heart valves. 
         [0003]    Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery. 
         [0004]    Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size. 
         [0005]    Despite the various improvements that have been made to the collapsible prosthetic heart valve delivery process, conventional storage, transfer and delivery techniques suffer from some shortcomings. Ideally, prosthetic heart valves are properly packaged at the manufacturing facility to ensure that the arriving valve performs as intended, and that the design and the quality of the valve is not compromised during delivery. However, in conventional prosthetic heart systems, the valve may sometimes be damaged during delivery. In addition to physical damage of the prosthetic heart valve during shipping and handling, valves may also be contaminated as they are transferred from storage or during implantation in the patient. 
         [0006]    There therefore is a need for further improvements to the devices, systems, and methods for transcatheter storage and delivery of collapsible prosthetic heart valves. Among other advantages, the present invention may address one or more of these needs. 
       SUMMARY OF THE INVENTION 
       [0007]    A device for holding an implantable medical device may include a jar for receiving the implantable medical device and a ring coupleable to the jar, the ring having a plurality of channels adapted to receive retaining features of the implantable medical device to stabilize the medical device within the jar. 
         [0008]    In some examples, the ring further comprises a plurality of openings through which a liquid may be drained from the jar. The jar may include a plurality of clips and the ring includes a plurality of indentations capable of mating with the clips to lock the ring to the jar. The plurality of clips may be evenly spaced about a circumference of the jar and the plurality of channels may extend radially in the ring. In some variations, the channels may extend circumferentially or may be angled. The plurality of channels may include three channels and may be adapted to receive a circular retaining feature of the implantable medical device. 
         [0009]    The plurality of channels may be adapted to receive a diamond-shaped retaining feature of the implantable medical device. The plurality of channels may be adapted to receive a square-shaped retaining feature of the implantable medical device. 
         [0010]    In some embodiments, a device for transporting an implantable medical device may include a ring coupleable to the implantable medical device, the ring having a plurality of channels adapted to receive retaining features of the implantable medical device. The ring may further include a plurality of openings through which a liquid may be drained from the jar. The plurality of channels may extend radially in the ring. The plurality of channels may include three channels. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Various embodiments of the presently disclosed delivery system are described herein with reference to the drawings, wherein: 
           [0012]      FIG. 1  is a side elevational view of a collapsible prosthetic heart valve showing the valve assembly attached to the stent; 
           [0013]      FIG. 2  is an enlarged side elevational view of a retaining element of a collapsible prosthetic heart valve; 
           [0014]      FIGS. 3A-E  are enlarged side elevational views of alternate embodiments of retaining elements; 
           [0015]      FIG. 4  is a diagrammatic view of a stent disposed within a jar for storage and/or transport; 
           [0016]      FIG. 5  is a top view of a ring coupled to a jar containing the stent; 
           [0017]      FIGS. 6A-6D  is a series of retainer element-channel interfaces coupling the stent to a ring; 
           [0018]      FIG. 7A  is a partial perspective view of a tool for decoupling the ring from the jar; 
           [0019]      FIG. 7B  is a partial perspective view of a tool and a threaded shaft for decoupling the ring from the jar; 
           [0020]      FIG. 7C  is a partial perspective view of a press-fit shaft for decoupling the ring from the jar; 
           [0021]      FIG. 7D  is a perspective view showing a ring being decoupled from the jar; 
           [0022]      FIG. 7E  is a perspective view showing the heart valve being rinsed; 
           [0023]      FIG. 7F  is a perspective view showing the heart valve being inserted into the support member of a valve loading device; and 
           [0024]      FIG. 7G  is a partial perspective view showing a heart valve inserted in the support member with the ring removed. 
       
    
    
       [0025]    Various embodiments of the present invention will now be described with reference to the appended drawings. It is to be appreciated that these drawings depict only some embodiments of the invention and are therefore not to be considered limiting of its scope. 
       DETAILED DESCRIPTION 
       [0026]    As used herein, the term “proximal,” when used in connection with a prosthetic heart valve, refers to the end of the heart valve closest to the heart when the heart valve is implanted in a patient, whereas the term “distal,” when used in connection with a prosthetic heart valve, refers to the end of the heart valve farthest from the heart when the heart valve is implanted in a patient. 
         [0027]      FIG. 1  shows a collapsible prosthetic heart valve  100  according to an embodiment of the present disclosure. The prosthetic heart valve  100  is designed to replace the function of a native aortic valve of a patient. Examples of collapsible prosthetic heart valves are described in International Patent Application Publication No. WO/2009/042196; U.S. Pat. No. 7,018,406; and U.S. Pat. No. 7,329,278, the disclosures of all of which are hereby incorporated herein by reference. As discussed in detail below, the prosthetic heart valve has an expanded condition and a collapsed condition. Although the invention is described herein as applied to a prosthetic heart valve for replacing a native aortic valve, the invention is not so limited, and may be applied to prosthetic valves for replacing other types of cardiac valves. 
         [0028]    The prosthetic heart valve  100  includes a stent or frame  102 , which may be wholly or partly formed of any biocompatible material, such as metals, synthetic polymers, or biopolymers capable of functioning as a stent. Suitable biopolymers include, but are not limited to, elastin, and mixtures or composites thereof. Suitable metals include, but are not limited to, cobalt, titanium, nickel, chromium, stainless steel, and alloys thereof, including nitinol. Suitable synthetic polymers for use as a stent include, but are not limited to, thermoplastics, such as polyolefins, polyesters, polyamides, polysulfones, acrylics, polyacrylonitriles, polyetheretherketone (PEEK), ultra-high molecular weight polyethylene and polyaramides. The stent  102  may have an annulus section  110  adjacent a proximal end  150 , an aortic section  130  adjacent a distal end  152 , and a transition section  120  between the aortic section  130  and the annulus section  110 . Each of the annulus section  110 , the transition section  120  and the aortic section  130  of the stent  102  includes a plurality of struts  114 . Certain struts  114  may be joined to form a plurality of cells  112  connected to one another around the stent. The annulus section  110  and the aortic section of the stent  102  may include one or more annular rows of cells  112  connected to one another. For instance, the annulus section  110  may have two annular rows of cells  112 . The cells in the aortic section  130  may be larger than the cells in the annulus section  110 . The larger cells in the aortic section  130  better enable the prosthetic valve  100  to be positioned without the stent structure interfering with blood flow to the coronary arteries. When the prosthetic heart valve  100  is in the expanded condition, each cell  112  may be substantially diamond shaped. 
         [0029]    The annulus section  110  of stent  102  has a relatively small cross-section in the expanded condition, while the aortic section  130  has a relatively large cross-section in the expanded condition. Preferably, annulus section  110  is in the form of a cylinder having a substantially constant diameter along its length. The transition section  120  may taper outwardly from the annulus section  110  to the aortic section  130 . 
         [0030]    The stent  102  may also include a plurality of commissure features  116  for attaching the commissure between two adjacent leaflets to the stent. As can be seen in  FIG. 1 , the commissure features  116  may lie at the intersection of four cells  112 , two of the cells being adjacent one another in the same annular row, and the other two cells being in different annular rows and lying in end-to-end relationship. Preferably, commissure features  116  are positioned entirely within annulus section  110  or at the juncture of annulus section  110  and transition section  120 . Commissure features  116  may include one or more eyelets which facilitate the suturing of the leaflet commissure to the stent. 
         [0031]    The prosthetic heart valve  100  also includes a valve assembly  104  attached inside the annulus section  110  of the stent  102 . United States Patent Application Publication No. 2008/0228264, filed Mar. 12, 2007, and United States Patent Application Publication No. 2008/0147179, filed Dec. 19, 2007, the entire disclosures of both of which are hereby incorporated herein by reference, describe suitable valve assemblies. The valve assembly  104  may be wholly or partly formed of any suitable biological material or polymer. Examples of biological materials suitable for the valve assembly  104  include, but are not limited to, porcine or bovine pericardial tissue. Examples of polymers suitable for the valve assembly  104  include, but are not limited to, polyurethane, ultra-high molecular weight polyethylene and polyester. 
         [0032]    The valve assembly  104  may be secured to stent  102  by any suitable attachment means, such as suturing, stapling, adhesives or the like. The valve assembly  104  includes a cuff  106  and a plurality of leaflets  108  which collectively function as a one-way valve.  FIG. 1  illustrates a prosthetic heart valve for replacing a native tricuspid valve, such as the aortic valve. Accordingly, prosthetic heart valve  100  is shown in  FIG. 1  with three leaflets  108 , as well as three commissure features  116 . However, it will be appreciated that the prosthetic heart valves according to this aspect of the invention may have a greater of lesser number of leaflets and commissure features. 
         [0033]    Cuff  106  may be disposed on the lumenal surface of annulus section  110 , on the ablumenal surface of annulus section  110 , or on both surfaces, and the cuff may cover all or part of either or both of the lumenal and ablumenal surfaces of the annulus section.  FIG. 1  shows cuff  106  disposed on the lumenal surface of annulus section  110  so as to cover part of the annulus section while leaving another part thereof uncovered. The cuff  106  may be wholly or partly formed of any suitable biological material or polymer, such as ultra-high molecular weight polyethylene or PTFE. 
         [0034]    A first edge (not shown) of each leaflet  108  may be attached to the stent  102  by any of the various manners described above. For example, the first edge of each leaflet  108  may be sutured to the stent  102  by passing strings or sutures through the cuff  106  of the valve assembly  104 . The cuff and/or sutures may be formed from ultra-high-molecular-weight polyethylene. A second or free edge  124  of each leaflet  108  may coapt with the corresponding free edges of the other leaflets, thereby enabling the leaflets to function collectively as a one-way valve. 
         [0035]    As is shown in  FIG. 1 , the entirety of valve assembly  104 , including the leaflet commissures, may be positioned in the annulus section  110  of stent  102 . When opened, the leaflets may extend further into the transition section or may be designed such that they remain substantially completely within the annulus section. That is, substantially the entirety of valve assembly  104  may be positioned between the proximal end  150  of stent  102  and the commissure features  116 , with none of the valve assembly  104  positioned between commissure features  116  and the distal end  152  of the stent. 
         [0036]    It will also be noted that while the inventions herein described are predominately discussed in terms of a tricuspid valve and a stent having a shape as illustrated in  FIG. 1 , the valve could be a bicuspid valve, such as the mitral valve, and the stent could have different shapes, such as a flared or conical annulus section, a less-bulbous aortic section, and the like, and a differently shaped transition section. 
         [0037]    Stent  102  may include one or more retaining elements  118  at the distal end  152  thereof, the retaining elements being sized and shaped to cooperate with female retaining recesses provided on a deployment or storage device. Additionally, the retaining elements  118  may be disposed at the proximal end  150  of the device or on both ends of the device. The engagement of retaining elements  118  with the female retaining recesses on the deployment device helps maintain prosthetic heart valve  100  in assembled relationship with the deployment or storage device, minimizes longitudinal movement of the prosthetic heart valve relative to the deployment device during unsheathing or resheathing procedures, and helps prevent rotation of the prosthetic heart valve relative to the deployment device as the deployment device is advanced to the target location and during deployment. 
         [0038]    In operation, the embodiments of the prosthetic heart valve described above may be used to replace a native heart valve, such as the aortic valve, a surgical heart valve or a heart valve that has undergone a surgical procedure. The prosthetic heart valve may be delivered to the desired site (e.g., near a native aortic annulus) using any suitable delivery device. During delivery, the prosthetic heart valve is disposed inside the delivery device in the collapsed condition. The delivery device may be introduced into a patient using a transfemoral, transapical, transseptal, transaxillary or any other percutaneous approach. Once the delivery device has reached the target site, the user may deploy the prosthetic heart valve. Upon deployment, the prosthetic heart valve expands into secure engagement within the native aortic annulus. When the prosthetic heart valve is properly positioned inside the heart, it works as a one-way valve, allowing blood to flow in one direction and preventing blood from flowing in the opposite direction. 
         [0039]    In a prosthetic heart valve, the valve assembly may be spaced from the distal or aortic end of the stent by a distance that enables deployment of the heart valve by an amount sufficient for the valve leaflets of the prosthetic valve to operate as intended, while the distal end  152  of the stent remains captured by the delivery device. More particularly, as will be explained further below, the annulus end of the prosthetic heart valve may be deployed first while the aortic end of the prosthetic heart valve remains at least partially covered by the distal sheath of the delivery device. The annulus portion of the prosthetic heart valve may be deployed so that the entirety of the valve leaflets, up to and including the commissures, is deployed and fully operational. By deploying the prosthetic heart valve in this manner, the user can determine whether the valve leaflets are properly positioned relative to the native valve annulus, and whether the valve is functioning properly. If the user determines that the position and operation of the valve are acceptable, the remainder of the valve may be deployed. However, if it is determined that the leaflet position is improper or that the valve is not functioning properly, the user may resheath the valve and either reposition it for redeployment, or remove it entirely from the patient. This can be particularly important in very high risk patients who would typically be recipients of these types of valves, because of the nature of their condition and the impact that may have on the shape and/or condition of the native valve and valve annulus. 
         [0040]      FIG. 2  is an enlarged view of the retaining element  118  described in  FIG. 1 , above. As shown in  FIG. 2 , one or more struts  114  may terminate in a circular retaining element  118 . Retaining element  118  may include an eyelet  210  used to position, transfer or adjust the position of the stent via a snare as will be described later. Retaining elements  118  may also be useful in implanting the heart valve  100  in a patient by mating to a delivery device as described above with reference to  FIG. 1 . 
         [0041]      FIGS. 3A-E  illustrate several variations of the retaining element shown in  FIG. 2  to aid in storage, shipment, transfer and delivery of a prosthetic heart valve.  FIG. 3A  illustrates a first example of a retaining element  118  at the end of a strut  114 , the retaining element  118  being in the shape of a square. As with the retaining element shown in  FIG. 2 , square retaining element  118  may include one or more eyelets  210 . It will be understood that eyelet  210  need not be circular and that various configurations of the eyelet, such as oval, triangular and square eyelets are contemplated.  FIG. 3B  illustrates a diamond-shaped retaining element  118  attached to a strut  114 , the retaining element having an eyelet  210 .  FIG. 3C  illustrates an oblong retaining element  118  having an elongated eyelet  210 . 
         [0042]      FIG. 3D  illustrates a substantially semi-circular retaining element  118  having a circular eyelet  210 . Retaining element  118  may further include a pair of tabs  330  that form recesses  340  between tabs  330  and strut  114 . Recesses  340  may be used as additional members for snaring the stent during repositioning, loading and/or delivery.  FIG. 3E  illustrates yet another example of retaining element  118 . The retaining element  118  of  FIG. 3E  is circular in form but also includes a pair of separate tabs  330  similar to those described in  FIG. 3D . In contrast to the example shown in  FIG. 3D , tabs  330  are formed as part of strut  114  and not as part of retaining element  118 . As previously discussed, retaining element  118  may mate with female recesses on a deployment or delivery device. Thus, by forming tabs  330  on strut  114  instead of on retaining element  118 , the same deployment or storage devices may be used to couple to the stents regardless of whether they include tabs  330 . 
         [0043]      FIG. 4  illustrates one method of storing and transporting a stent within a jar. As seen in  FIG. 4 , jar  450  may be sized slightly larger than stent  400  and stent  400  may be placed in an upright position within the jar. A ring  500  may be placed on top of jar  450  to keep the stent  400  from moving during delivery and/or storage. An additional top cap (not shown) may be disposed on top of ring  500  to seal and secure stent  400  within jar  450 . 
         [0044]    Jar  450  may include a plurality of clips  460  which mate with a plurality of indentations  510  on ring  500  to align the ring with jar  450 . Clips  460  may also help secure ring  500  to jar  450 . Clips  460  may be pliable prongs that are simply bent over selected indentations of the ring. Alternatively, clips  460  may include spring clips which deform from an initial position to facilitate mating with the indentations, and then spring back into their original position within the indentations to hold the ring  500  in place. Additional sutures may also be used to secure the stent. The jar may be filled with a preserving solution that immerses stent  400 , such as glutaraldehyde, formaldehyde or an inert gas such as nitrogen. 
         [0045]      FIG. 5  illustrates a top view of ring  500  coupled to jar  450 . In the illustrated example, ring  500  includes three indentations  510  for aligning it with jar  450 . Ring  500  may further include a plurality of openings  520  to allow drainage of the preserving solution from jar  450  after removal of the top cap. Any number of openings  520  may be formed in ring  500  and the shape and size of the openings may be varied as desired. Ring  500  may further include a plurality of channels  530  adapted to receive the retaining elements  118  described above. The number of channels  530  may be the same as the number of retaining elements  118  on stent  102 . Channels  530  may be evenly spaced about the perimeter of ring  500  when retaining elements  118  are evenly spaced around the perimeter of stent  400 . As illustrated, ring  500  includes three channels  530 , although it will be understood that the ring may include two, three, four, five, six or more channels. 
         [0046]    The cross-sectional shape of channels  530  may be varied, and may be dependent upon the shape of the retaining elements  118  to be received therein.  FIGS. 6A-6D  illustrate a series of retaining element-channel interfaces.  FIG. 6A  illustrates a retaining element  118  similar to that shown in  FIG. 2  within a channel  530  of ring  500 . Channel  530  may include a beveled top surface  535  to properly locate and seat retaining element  118  in the channel. The same or similar retaining element  118  may also mate with a channel  530  having a square recess  540  in its top surface, as seen in  FIG. 6B . In other examples illustrated in  FIGS. 6C and 6D , channels  530  may have a beveled top surface for accepting square or diamond-shaped retaining elements  118 . It will be appreciated that the bevel angle illustrated in  FIG. 6D  is steeper than that of  FIG. 6C . Thus, the angle of the bevel of channel  530  may be selected to accommodate various retaining elements  118 . 
         [0047]    In operation, a fully assembled prosthetic heart valve  100  may be placed in a jar  450  having glutaraldehyde or other preserving solution. Ring  500  may be correctly positioned over jar  450  by aligning the clips  460  of the jar with the indentations  510  of the ring. Certain struts  114  of heart valve  400  that include retaining elements  118  may be guided into channels  530  of ring  500  and allowed to naturally radially expand until the retaining elements are affixed within the channels. Once all retaining elements  118  are mated within ring  500 , a top cap, such as a screw cap, may be affixed to jar  450  to seal heart valve  400  within the jar. Jar  450  may then be transported to a hospital or clinic for use. 
         [0048]    Once at the use location, the prosthetic heart valve  400  may be removed from jar  450  as will be described below. Ideally, prosthetic heart valve  400  is removed from jar  450  using aseptic techniques to maintain sterility and avoid contamination of the valve. 
         [0049]    A tool  700  may be used to detach ring  500  from jar  450 .  FIG. 7A  illustrates the use of tweezers to pull ring  500  off jar  450 . It will be understood that a hemostat, forceps, clamp or other similar instrument may likewise be used to remove ring  500  from jar  450  or that manual removal of ring  500  using fingers may be possible. As seen in  FIG. 7A , tool  700  grasps a portion of ring  500  and pulls it to decouple it from jar  450 , disengaging clips  460  from indentations  510 . 
         [0050]      FIG. 7B  shows a similar concept, but includes a tool having a threaded shaft  710  that mates with a threaded aperture  550  in the center of ring  500 . Instead of being threaded, shaft  710  may instead be press-fit or snap fit into a non-threaded aperture in the center of ring  500  to remove the ring from the jar as seen in  FIG. 7C . 
         [0051]    Regardless of the method of detachment, once ring  500  is decoupled from jar  450 , prosthetic heart valve  400  remains attached to ring  500  via the retaining elements  118 . 
         [0052]      FIG. 7D  illustrates a stent  400  coupled to a ring  500  being removed from jar  450 . For the sake of clarity, stent  400  does not include a valve assembly, although it will be understood that a completely assembled prosthetic heart valve  400  includes a valve assembly. 
         [0053]    Prosthetic heart valve  400  may be rinsed in a solution  730  while still being secured to ring  500 , as shown in  FIG. 7E . The rinsing solution may, for example, include a 0.9% sterile saline solution. Heart valve  400  may be immersed in rinsing solution  730  simply by grasping ring  500 , without the need to contact the valve, thereby reducing the likelihood of contamination and damage to the prosthetic heart valve. 
         [0054]    Using tool  700 , ring  500  may be maneuvered to place prosthetic heart valve  400  in a support member  750  of a valve loading system, as seen in  FIG. 7F . At this juncture, retaining elements  118  of heart valve  400  may be decoupled from channels  530  of ring  500  by sliding each retaining element  118  radially inward until it clears its associated channel  530 . The retaining elements  118  may be decoupled from the channels  530  together or one at a time.  FIG. 7G  illustrates heart valve  400  after being loaded into support member  750  and removal of ring  500 . Prosthetic heart valve  400  may now be ready for loading into a delivery device using the valve loading system. Thus, heart valve  400  may be shipped, transferred and loaded with minimal handing. 
         [0055]    Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. 
         [0056]    It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.