Patent Publication Number: US-11638580-B2

Title: Devices and methods for suturing a cardiac implant

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 15/326,567, filed Jan. 16, 2017, now U.S. Pat. No. 10,555,732, which is a U.S. National Stage of International Application No. PCT/US2015/040782, filed Jul. 16, 2015, which claims the benefit of U.S. Patent Application No. 62/025,117, filed Jul. 16, 2014, all of which are incorporated by reference herein in their entireties for all purposes. 
    
    
     FIELD 
     Described herein are devices and methods for suturing a cardiac implant using a surgical needle. 
     BACKGROUND 
     Needles are frequently used with a needle driver in many different surgical procedures, such as to close vascular tissues, during an aortotomy, and during heart valve surgery. These needles typically have a size and shape that is customized for each particular procedure. Such customized needles can be very expensive. During procedures, a surgeon often uses several different types of needles and sutures for different aspects of the procedure. The needles are typically used with one or more small reinforcing pledgets for each suture. The pledgets provide more resistance to the sutures and protect against the sutures cutting the tissue. However, during surgery, a suture occasionally breaks or pulls out of the needle, and as a consequence a pledget for that suture can come loose and can get lost inside the patient. During a cardiac valve replacement, for example, a surgeon may place 12-18 sutures within the native valve annulus, with each suture having a respective needle and its own respective pledget. The surgeon then drives each needle and respective suture through and anchorage part of the implant. Since each of the sutures is applied using a different needle, the cost of placing 12-18 sutures includes 12-18 times the cost of one needle. 
     SUMMARY 
     The disclosed devices and methods can reduce the total cost of the needles by using the same needle for all or many of the sutures, can eliminate or reduce the risk of losing pledgets within the patient&#39;s body, and/or can provide an alternative and easier way to place the needle/sutures within the tissue and cardiac implants. 
     An exemplary suture needle includes an elongated rigid body having a sharp front end for piercing and a flexible looped portion coupled to the rear end the rigid body. In some embodiments, the looped portion comprises four substantially linear segments linked together end-to-end with three bends joining the four linear segments such that the looped portion has a generally quadrilateral shape in an open configuration. The looped portion is resiliently collapsible from the open configuration to a collapsed configuration such that the surgical needle is adapted to capture a suture in the looped portion in the collapsed configuration while the surgical needle is drawn through a target object. The looped portion is then resiliently expandable from the collapsed configuration back to the open configuration, such that the surgical needle is adapted to release the captured suture from the looped portion after the surgical needle has drawn the suture through a target object. 
     An exemplary suture spool assembly comprises a rigid outer housing and at least one spool of suture material suspended within the outer housing such that the spool is free to rotate relative to the outer housing about a central axis of the spool. For each spool, the housing can include a suture outlet through which a free end of the suture material on the spool extends, such that tension on the free end of the suture material causes the spool to rotate and dispense the suture material from the spool through the suture outlet. The assembly can include two or more spools that each hold different kinds of suture material suture materials. The housing can be opened and closed to insert, remove and replace the spools. 
     Also described herein are annular pledgets having diametrical dimensions similar to an outer anchorage ring of a cardiac implant such that a single annular pledget can be used with the plurality of sutures that secure the cardiac implant to native tissue around the perimeter of the cardiac implant. 
     An exemplary method of securing a cardiac implant comprises dispensing a first suture from a suture spool assembly, inserting the first suture through an opening in a surgical needle, passing the surgical needle and first suture through a first native tissue implant location, passing the surgical needle and first suture through an annular pledget, passing the surgical needle and first suture through an outer anchorage portion of a cardiac implant, and securing the cardiac implant to the first native tissue implant location using the first suture, with the annular pledget positioned between the first native tissue implant location and the outer portion of a cardiac implant. The method can further include reusing the same needle to apply one or more additional sutures that secure the surgical implant to one or more respective additional native tissue locations, wherein the additional sutures pass through the same annular pledget. A single annular pledget can be used that has roughly the same diametrical dimensions as the outer anchorage portion of the cardiac implant. 
     The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows an exemplary surgical needle with a straight body and a curved looped end. 
         FIG.  2    shows an exemplary surgical needle with a curved body and a curved looped end. 
         FIG.  3    shows an exemplary surgical needle with a curved body and a four-sided looped end. 
         FIG.  4    shows an exemplary surgical needle with a straight body and slotted end. 
         FIG.  5    shows an exemplary surgical needle passing a suture through an exemplary cardiac implant. 
         FIG.  6    shows an exemplary annular pledget. 
         FIG.  7    is a top view of an exemplary cardiac implant with two pairs of sutures passing through its outer body. 
         FIG.  8    is a schematic cross-sectional side view of an exemplary suture spool assembly, showing an internal suture spool and a suture passing from the spool through an aperture out of the assembly. 
         FIG.  9    is a perspective view of the suture spool assembly of  FIG.  8   . 
         FIG.  10    is a side view of the suture spool assembly of  FIG.  8   . 
         FIG.  11    is an exploded perspective view of the suture spool assembly of  FIG.  8   . 
         FIG.  12    is an exploded side view of the suture spool assembly of  FIG.  8   . 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows an exemplary needle  2  that comprises a body  4  with a sharp distal tip  6  at a distal or lead end and a loop  8  extending from the proximal or rear end. The body  4  can be solid or tubular, and can be made from any sufficiently strong material, such as stainless steel. In some embodiments, the body  4  is made from a sharpened solid wire, and in other embodiments the body  4  is made from a hypotube with a beveled tip. The body  4  can have a diameter and length selected to match the application for which it is intended. In one example, the body  4  can have an outer diameter of about 0.025 inch and a length of about 1.0 inch. The distal tip  6  can be beveled or otherwise sharpened to a point for puncturing tissue and an implant. The loop  8  can have a rounded, generally teardrop shape as shown in  FIG.  1   . The loop  8  can comprise a thin, flexible, resilient strand, such as a stainless steel wire, or can comprise other thin, strong, resilient material, such as polymeric material. The loop  8  can be attached to the body  4  in any secure manner, such as by welding (e.g., laser welding) or bonding the ends of the loop directly to the body, or by inserting ends of the loop into a hole or cavity in the proximal end of the body (e.g., with a tubular body or a solid body) and crimping the proximal end of the body onto the ends of the loop. 
     The loop  8  receives a suture (or sutures) such that the needle  2  can penetrate through tissue, a valve frame, sewing cuff, or other component of a prosthetic device, and carry the suture through the device. When the loop  8  passes through tissue or another object, the loop  8  collapses and grips the suture securely, preventing the suture from sliding out. The loop  8  can resiliently re-expand, at least partially, back to its original teardrop shape after passing through an object to release the suture and reload a new suture. 
       FIG.  2    shows another exemplary needle  10  comprising a curved body  12  with a sharp distal tip  14  at the distal end and a loop  16  extending from the proximal end. The needle  10  is similar to the needle  2 , except that the body  12  is curved. The curved body  12  can have any degree of curvature. For example, the body  12  can form a semi-circle, or a quarter of a circle, or other arcuate shapes. 
       FIG.  3    shows another exemplary needle  20  comprising a curved body  22  with a sharp distal tip  24  at the distal end and a loop  26  extending from the proximal end. The loop  26  includes substantially straight sides extending between angled bends  28  and  30 , forming a generally diamond shape or kite shape. This shape can help the loop  26  re-open after passing through a narrow passage, such as after passing through a valve frame or sewing cuff. The two bends  28  can remain separated from each other even after the loop  26  has plastically deformed and collapsed to some degree following several passes through a valve frame or other object. Such resilient separation can allow a surgeon to continue to rethread sutures through the loop  26  over and over again until the surgery is complete, reusing the single needle for each suture. Many other loop shapes and configurations can also be used in other embodiments. In alternative embodiments, the rigid body  22  can be straight or can any other suitable curvature. 
     In general, a surgical needle can comprise an elongated rigid body having a sharp front end for piercing and a rear end, and a looped portion coupled to the rear end the rigid body. The looped portion can comprise four substantially linear segments linked together end-to-end with three bends joining the four linear segments such that the looped portion has a generally quadrilateral shape in an open configuration. The looped portion is resiliently collapsible from the open configuration to a collapsed configuration where the four linear segments are generally parallel and extending linearly from the rear end of the rigid body, such that the surgical needle is adapted to capture a suture between the four linear segments in the collapsed configuration while the surgical needle is drawn through a target object, such as a pledget and/or a cardiac implant. The looped portion is also resiliently expandable from the collapsed configuration back to the open configuration, such that the surgical needle is adapted to release the captured suture from between the four linear segments after the surgical needle has drawn the suture through a target object. 
     In some embodiments, the looped portion has a generally kite-shaped formation in the open configuration (like the shape shown in  FIG.  3   ), wherein a first two of the four linear segments have substantially the same length, and a second two of the four linear segments have substantially the same length, but the first two linear segments have a different length than the second two linear segments. In some embodiments, the three bends in the looped portion each define an interior angle between the linear segments joined by the respective bend, and when the looped portion is in the collapsed configuration, a first of the three bends (e.g., bend  30  in  FIG.  3   ) has an interior angle that is less than 10°, such as near 0°, and the other two of the three bends (e.g., bends  28  in  FIG.  3   ) have an interior angle that is greater than 170°, such as near 180°. 
       FIG.  4    shows is a schematic side view of another exemplary needle  40  that comprises a sharp distal tip  42  and an angled slot  44  adjacent the proximal end for receiving a suture. The slot  44  can extend proximally from a lateral opening  46  such that a suture in the slot is restricted from exiting the slot while the needle  40  is passed through an object and the object applies proximally directed forces on the suture. In some such embodiments, the lateral opening  46  can be plastically closed after inserting a suture into the slot, and manually re-opened to release the suture and load another suture. The ability to load and remove a suture through laterally into and out of the slot  44  can obviate the need to thread an end of the suture through a loop, eyelet, or other enclosed opening to load and remove the suture. This can save time during the procedure and can allow the needle  40  to be applied onto or removed from a suture when neither end of the suture is free, such as with a looped portion of a suture or a suture with both ends extending into tissue or other objects. 
       FIG.  5    shows an exemplary needle  52  (similar to the needle  2  in  FIG.  1   ) passing through an outer annular portion of a cardiac implant  50  (e.g., a sewing ring of a prosthetic heart valve) while loaded with a suture  54 . The suture  54  passes through a proximal loop portion of the needle  52  while a sharpened distal end has already puncture the implant  50 .  FIG.  7    shows the exemplary cardiac implant  50  from a top view after several sutures  54  have been threaded through it. Any of the needles disclosed herein can be loaded with a variety of different types of sutures. For example, the sutures can vary in material, size, and/or color. 
       FIG.  6    shows an exemplary pledget  60  that can be used in place of a plurality of smaller individual pledgets. The pledget  60  comprises an annular body with a central opening  62 . The annular body of the pledget  60  can be sized to correspond with the diameter of a particular cardiac implant, such as the cardiac implant  50  in  FIG.  5   , with the central opening  62  being aligned with the flow pathway through the cardiac implant. The pledget  60  can be placed along the lower surface of the implant such that a plurality of sutures (e.g., all 12-18 sutures) can pass through the single pledget  60  and then through the cardiac implant. If one of the sutures breaks or comes loose, the pledget  60  is still retained by the other sutures and it is less prone to become lost inside of the patient like individual smaller pledgets for each suture. The pledget  60  can be made of any suitable material (e.g., Teflon®) and can have any shape and size to correspond with the suture pattern for a particular implant. For example, the pledget may have a D-shape for a mitral valve implant. 
       FIGS.  8 - 12    illustrate an exemplary suture spool assembly  70  that can be used to contain and dispense sutures for quick and easy access during implantation of cardiac implants. The assembly  70  can comprise a housing  72  that forms a handle portion  74  at one end and houses one or more spools  78  of sutures. A cap  76  can close off the opposite end and include an opening  82  to allow the suture  80  to extend out of the assembly to be dispensed. The cap  76  can include a blade or other cutting element to cut the suture when a desired length has been pulled out. As shown in  FIGS.  9  and  11   , the cap  76  can be secured to the housing  72  via fasteners (e.g., screws) passing through openings  84  and  88 . 
     As shown in  FIGS.  11  and  12   , at least one spool  78  can be mounted within a cavity  86  inside the housing  72 . Each spool  78  can include an outer body  96  that does not rotate relative to the housing  72  and an inner body  92  that rotates within the outer body about an axle  94 . The inner body  92  can be loaded with the suture material and the leading end of the suture material can pass through an opening  90  in the outer body  96  and out through the opening  82  in the cap  76  to be dispensed. In embodiments having more than one spool, the spools can be oriented side-by-side and the cap  76  can include a corresponding number of opening  82  to dispense each different suture from. Each different suture and/or the spools themselves can have a different color for visual identification. In some embodiments, the plural spools can share a common rotation axle, with in other embodiment, individual axles are included. Each spool can be winded with any length of suture material, such as about 10-30 feet, or about 20-25 feet, of suture material. The total length on the spool can be sufficient to supply material for all the sutures needed to complete a given procedure. The cap  76  can be easily removed and replaced to load, remove, or swap out the spools. 
     During surgery, the user can dispense a length of suture material from the suture spool assembly  70  for a first suture, cut the suture material to the desired length, insert the suture material into the needle, pass the needle and suture through the tissue where the cardiac implant is to be secured, pass the needle and suture through the pledget and the cardiac implant, release the suture from the needle, secure the suture to secure the implant to the tissue, then repeat the process for each suture location using the same needle for each suture. 
     The disclosed devices, systems, and methods can be used with various types of sutures, threads, cords, wires, cables, lines, filaments, or similar objects (which are collectively referred to herein as “sutures” for ease of description). Exemplary suture materials can include biological tissues (e.g., collagen-based tissue), polyglycolide, polydioxanone, polyester, nylon, polypropylene, and other polymeric materials. Some sutures comprise several strands of fibers braided or woven together. Any suitable materials can be used in the construction of the needles, pledgets, suture spools, suture dispensers, and/or other devices disclosed herein. 
     For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, devices, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, devices, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. 
     As used herein, the term “and/or” used in a list of elements means any one or more of the listed elements. For example, the phrase “A, B, and/or C” means “A,” “B,” “C,” “A and B,” “A and C,” “B and C” or “A, B and C.” 
     As used herein, the term “coupled” generally means physically linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language. 
     In view of the many possible embodiments to which the principles disclosed herein may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosure. The scope of this disclose is at least as broad as the scope of the following claims. I therefore claim all that comes with the scope of these claims.