Abstract:
A heart valve delivery system includes a low-profile catheter having an outer sheath, the outer sheath having therein a stent and a replacement heart valve. In an unemployed configuration, the stent is located distally to the replacement heart valve. Upon deployment, however, the stent and replacement heart valve are expanded and the replacement heart valve is situated within the stent.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/939,534, filed Jul. 11, 2013, which claims the benefit of and priority to U.S. Provisional Application No. 61/670,776, filed Jul. 12, 2012, the entire contents of which are herein incorporated by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety. 
         [0004]    Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below. 
         [0005]    A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims. 
         [0006]    Various forms of replacement heart valves are known in the art. Moreover, a variety of catheter systems have been developed to implant such replacement heart valves. One method of implantation is Transcatheter Aortic-Valve Implantation (TAVI). Existing TAVI systems suffer from a number of deficiencies, however. In particular, known TAVI systems are relatively large in diameter, which can impede insertion of the catheter. Further, known TAVI systems suffer from a lack of flexibility, which results from the large size of known TAVI systems. Additionally, the large size requires a large entrance incision, further complicating the procedure and increasing risk to the patient. 
         [0007]    In light of the foregoing drawbacks associated with existing TAVI systems, there remains a need for a TAVI system having a smaller profile and greater flexibility. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    In some embodiments, a percutaneous heart valve delivery system has a first configuration and a second configuration. In some embodiments, the system comprises a sheath, a stent, a replacement valve, and at least one suture line. In some embodiments, the replacement valve and stent each have respective proximal ends and distal ends. In some embodiments, the at least one suture line extends between the stent and the replacement valve. In some embodiments, when the system is in the first configuration, the stent and replacement valve are disposed within the sheath and the distal end of the replacement valve is proximal to the proximal end of the stent. Further, in some embodiments, when the system is in the second configuration, the distal end of the replacement valve is distal to the proximal end of the stent. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0009]      FIG. 1  shows a partial cutaway view of a portion of an embodiment of the heart valve delivery system  10 . 
           [0010]      FIG. 2  shows a cutaway view of a portion of the embodiment of  FIG. 1  in a partially deployed configuration  24 . 
           [0011]      FIGS. 3A-3E  show schematic views of the heart valve delivery system  10  in various stages of deployment. 
           [0012]      FIG. 4  shows an embodiment of the pull line  18  and suture  26  of the heart valve delivery system  10 . 
           [0013]      FIG. 5  shows a cutaway view of a portion of an embodiment of the heart valve delivery system  10  prior to deployment. 
           [0014]      FIG. 6  shows the stent  14  and replacement valve  16  of  FIG. 5  after deployment thereof 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    While this invention may be embodied in many different forms, there are described herein specific embodiments. This description is an exemplification of the principles of the invention and is not intended to limit it to the particular embodiments illustrated. 
         [0016]    For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. 
         [0017]    In some embodiments, for example as shown in  FIG. 1 , a heart valve delivery system  10  comprises a sheath  12 , a stent  14 , a replacement valve  16 , and an inner tubular member  15 . In some embodiments, the heart valve delivery system  10  further comprises at least one pull line  18 . Additionally, in some embodiments, the heart valve delivery system  10  further comprises a nosecone  20 . In some embodiments, the nosecone  20  is attached to the inner tubular member  15 , for example via an overmolding process. In some embodiments, the heart valve delivery system  10  is designed for percutaneous implantation. 
         [0018]    The heart valve delivery system  10  has a delivery configuration  22  ( FIG. 1 ) wherein, in some embodiments, the stent  14  is disposed distally to the replacement valve  16  within the sheath  12 . In this way, in some embodiments, the stent  14  and replacement valve  16  are longitudinally spaced apart from one another along the length of the sheath  12  when in the delivery configuration  22 . Placement of the stent  14  and replacement heart valve  16  in a non-overlapping fashion, while in the sheath  12 , allows the heart valve delivery system  10  to be smaller and more flexible than known TAVI systems. In some embodiments, the stent  14  is deployed from the sheath  12  prior to deployment of the replacement valve  16 . Moreover, in some embodiments, the replacement heart valve  16  is tightly wrapped into a cylindrical shape within the sheath  12 . 
         [0019]    With regard to  FIG. 2 , the heart valve delivery system  10  is shown in a partially deployed configuration  24  within the ascending aorta  6  and aortic valve  8 . As illustrated in  FIG. 2 , the stent  14  and replacement heart valve  16  have been deployed from the sheath  12 . In particular, in some embodiments, the stent  14  is deployed from the sheath  12  and expanded, prior to deployment of the replacement heart valve  16 . In order to facilitate deployment and expansion of the stent  14  and replacement heart valve  16 , in some embodiments, the heart valve delivery assembly  10  comprises at least one suture line  26  extending between the stent  14  and the replacement heart valve  16 . Moreover, in some embodiments, the heart valve delivery system  10  comprises a pusher  17 , which can help facilitate deployment of the replacement valve  16 . 
         [0020]    In some embodiments, the suture line  26  is used to secure the replacement valve  16  to the stent  14 . As schematically shown in  FIG. 3A , the stent  14  and the replacement valve  16  are in an unexpanded configuration, for example as they would be disposed within a sheath  12  (not shown) for introduction into a body lumen. The unexpanded configuration is alternatively referred to herein as a first configuration. As further shown in  FIG. 3A , in some embodiments, the pull line  18  extends through a first loop  28  and is doubled-back on itself, Further, the pull line  18  extends proximally to the proximal end of the sheath  12  ( FIG. 1 ) so that the pull line  18  can be manipulated by the operator. 
         [0021]    With further regard to  FIG. 3A , in some embodiments, the suture line  26  is attached to the first loop  28 . The suture line  26  extends distally from the first loop  28  through a second loop  30 , a portion of the replacement valve  16 , and the stent  14 . In some embodiments, a segment of the suture line  26  is formed into the second loop  30  in a slip-knot or similar knot that tightens on itself. In some embodiments, the suture line  26 , or a portion thereof, is formed from a bioabsorbable material. In some embodiments, the bioabsorbable material comprises or consists of hydro polymers, hydro gels, collagen, or suitable combinations thereof. In some embodiments, the bioabsorbable material includes poly(lactic-co-glycolic acid) (PLGA) or poly(lactic acid) (PLA), for example. 
         [0022]    As further shown in  FIG. 3A , the stent  14  has a proximal end  33  and a distal end  34 . In some embodiments, prior to deployment, the proximal end  33  of the stent  14  is located distally to the distal end  38  of the replacement valve  16 . Stated differently, in some embodiments, the distal end  38  of the replacement valve  16  is proximal to the proximal end  33  of the stent  14 . 
         [0023]    Turning to  FIG. 3B , in order to facilitate deployment of the stent  14  and replacement valve  16 , the stent  14  is first deployed, for example via a sheath  12 , and expanded against an aortic valve, as shown in  FIG. 2 . Thereafter, the operator pulls on the pull line  18 . In particular, in some embodiments, the operator pulls both ends of the pull line, as illustrated via arrows  32 . In this way, the replacement valve  16  is moved distally toward the stent  14 . 
         [0024]    With regard to  FIG. 3C , pulling the pull line  18  further moves the replacement valve  16  distally until the replacement valve  16  is situated within the stent  14 . In some embodiments, as the replacement valve  16  is moved into position within the stent  14 , the replacement valve  16  is first partially expanded, then it is situated within the stent  14  and, finally, it is fully expanded and anchored to the stent  14  via suture line  26 . In some embodiments, the replacement valve  16  is moved into position within the stent  14  while in an unexpanded configuration and subsequently expanded. Further, in some embodiments, the replacement valve  16  is fully expanded and then moved into position within the stent  14 . In some embodiments, the replacement valve  16  is expanded within the stent  14  by pulling on the suture line  26 . Pulling of the suture line  26  thereby moves the replacement valve  16  longitudinally to position within the stent  14  and also expands the replacement valve  16  in a radial direction. 
         [0025]    As shown in  FIG. 3D , in some embodiments, after the replacement valve  16  is disposed within the stent  14 , one end of the pull line  18  is released and the operator pulls on the other end, as illustrated via arrow  32  in  FIG. 3D . In this way, the pull line  18  is removed from the patient&#39;s body, leaving the stent  14 , the replacement valve  16 , and the suture line  26 —which, in the illustrated embodiment, forms the second loop  30 . 
         [0026]    With regard to  FIG. 3E , in some embodiments, and upon deployment, the heart valve delivery system  10  is in a second configuration wherein the distal end  38  of the replacement valve  16  is distal to the proximal end  33  of the stent  14 . Further, the delivery system  10  is removed from the patient&#39;s body. 
         [0027]    In some embodiments, the suture line  26  extends through a distal end  34  of the stent  14  and a distal end  38  of the replacement valve  16 . Moreover, in some embodiments, the suture line  26  is routed through holes or slots in the stent  14 . In some embodiments, the suture line  26  is routed between struts. It is also contemplated that the suture line  26  is anchored or tied to the struts, holes, slots, or other features on the stent  14 . 
         [0028]    In some embodiments, the replacement valve  16  has one or more reinforced areas through which the suture line  26  can be routed. In some embodiments, the reinforced areas are sections of harder or more rigid material. In some embodiments, the suture line  26  is attached to such reinforced areas. 
         [0029]    Although illustrated in  FIGS. 3A-3E  with only a single suture line  26 , it will be appreciated that, in some embodiments, the heart valve delivery assembly  10  comprises six to twenty suture lines  26 . In some embodiments, the heart valve delivery assembly  10  has 8, 10, 12, or 14 suture lines  26 . 
         [0030]    In some embodiments, the stent  14  comprises a skirt disposed at a distal end  34  thereof. In some embodiments, the skirt provides a seal between the stent  14  and the adjacent tissue of the aortic valve  8 , upon implantation of the stent  14 . In some embodiments, the suture line  26  is routed through a portion of the skirt. 
         [0031]    In some embodiments, the replacement valve  16  comprises an expandable frame. In some embodiments, the expandable frame comprises a shape-memory material, for example a nickel-titanium alloy. Other suitable material can also be used. 
         [0032]    Further, in some embodiments, the replacement valve  16  is expanded by way of suture line  26 . In particular, in some embodiments, as the pull line  18  is pulled by the operator, the suture line  26  tightens and expands the replacement valve  16 . In some embodiments, the replacement valve  16  is expanded without a self-expanding frame. 
         [0033]    With regard to  FIG. 4 , an embodiment of the suture line  26  and pull line  18  is shown. In the embodiment of  FIG. 4 , the suture line  26  forms the first loop  28  and second loop  30 . In some embodiments, the suture line  26  forms a plurality of twists  40  to form a plurality of loops, which facilitate tightening of the suture line  26 , as desired. 
         [0034]    Turning to  FIG. 5 , an embodiment of the heart valve delivery assembly  10  is shown therein. In the embodiment of  FIG. 5 , the stent  14  and replacement valve  16  are longitudinally offset from one another while in the sheath  12 . Further, the stent  14  is deployed prior to deployment of the replacement valve  16 . 
         [0035]    In some embodiments, for example as shown in  FIG. 5 , the stent has a locking slot  32 . In some embodiments, the locking slot  32  is disposed at or near the distal end  34  of the stent  14 . Further, in some embodiments, the replacement valve  16  has a protruding member  36  which, in some embodiments, is disposed at or near the distal end  38  of the replacement valve  16 . In some embodiments, the locking slot  32  is annularly shaped. Further, in some embodiments, the protruding member  36  is annularly shaped to mate with the locking slot  32 . 
         [0036]    As shown in  FIG. 6 , upon deployment of the stent  14  and replacement valve  16 , the protruding member  36  locks into place within the locking slot  32 , thereby securing the replacement valve  16  within the stent  14 . It will appreciated that the replacement valve  16  and stent  14  can include any suitable arrangement of locking mechanism. For example, in some embodiments, the replacement valve  16  has a locking slot while the stent  14  has a protruding member  36 . Other suitable mechanisms and arrangements are also permissible. 
         [0037]    In some embodiments, the stent  14  and replacement valve  16  are deployed by first deploying the stent  14  from the sheath  12  ( FIG. 5 ). Upon release of the stent  14  from the sheath  12 , the stent  14  can be self-expanded or it can be expanded via a balloon. Once the stent  14  is expanded at a desired location within the aortic valve  8 , the sheath  12  is adjusted for placement of the replacement valve  16  within the stent  14 . Subsequently, the replacement valve  16  is deployed from the sheath  12 . In some embodiments, the replacement valve  16  partially expands within the stent  14  but it is still movable longitudinally within the stent  14 . In this way, the replacement valve  16  is moved, as necessary, until the protruding member  36  locks into place within the locking slot  32 . In some embodiments, the replacement valve  16  is self-expandable. 
         [0038]    It will be appreciated that the heart valve delivery system  10  is not limited to use as a TAVI device. The heart valve delivery system  10  can also be used for the replacement of other heart valves. 
         [0039]    In some embodiments, the sheath  12 , having a stent  14  and replacement valve  16 , has a diameter less than 14 French. In some embodiments, the sheath  12 , having a stent  14  and replacement valve  16 , has a diameter between 14 and 18 French. 
         [0040]    The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this field of art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to.” Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
         [0041]    Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim  1  should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below. 
         [0042]    This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.