Abstract:
A surgical suturing device is disclosed. The surgical suturing device has a forked guide tip having a plurality of legs, wherein each of the plurality of legs comprises a proximal end, an anatomical variation, and a distal end. A method of chord replacement for a heart valve is also disclosed. A suture is placed in a papillary muscle using a surgical suturing device having a forked guide tip and a papillary suture. A leaflet suture is placed in a leaflet. The papillary suture and the leaflet suture are loaded in a suture fastener from opposite directions in a coaxial fashion. The length of the papillary suture and/or the leaflet suture are adjusted relative to the suture fastener to achieve a desired replacement chord length. The suture fastener is attached to the papillary suture and the leaflet suture to lock the desired replacement chord length.

Description:
RELATED APPLICATION 
       [0001]    This patent application claims priority to U.S. Provisional Patent Application 62/000,280 filed May 19, 2014 and entitled, “MINIMALLY INVASIVE SURGICAL SUTURING DEVICE FOR PAPILLARY MUSCLES AND METHODS THEREOF”. The entire provisional patent application 62/000,280 is hereby incorporated by reference in its entirety. 
     
    
     FIELD 
       [0002]    The claimed invention relates to surgical suturing, and more specifically to minimally invasive surgical suturing devices and methods for suturing papillary muscles. 
       BACKGROUND 
       [0003]    The human heart relies on a series of one-way valves to help control the flow of blood through the chambers of the heart. For example, referring to  FIG. 1 , deoxygenated blood returns to the heart  20 , via the superior vena cava  22  and the inferior vena cava  24 , entering the right atrium  26 . The heart muscle tissue contracts in a rhythmic, coordinated heartbeat, first with an atrial contraction which aids blood in the right atrium  26  to pass through the tricuspid valve  28  and into the right ventricle  30 . Following atrial contraction, ventricular contraction occurs and the tricuspid valve  28  closes. Ventricular contraction is stronger than atrial contraction, assisting blood flow through the pulmonic valve  32 , out of the heart  20  via the pulmonary artery  34 , and to the lungs (not shown) for oxygenation. Following the ventricular contraction, the pulmonic valve  32  closes, preventing the backwards flow of blood from the pulmonary artery  34  into the heart  20 . 
         [0004]    Oxygenated blood returns to the heart  20 , via the pulmonary veins  36 , entering the left atrium  38 . Left atrial contraction assists blood in the left atrium  38  to pass through the mitral valve  40  and into the left ventricle  42 . Following the atrial contraction, ensuing ventricular contraction causes mitral valve  40  closure, and pushes oxygenated blood from the left ventricle  42  through the aortic valve  44  and into the aorta  46  where it then circulates throughout the body. Under nominal conditions, prolapse of mitral valve  40  is prevented during ventricular contraction by chordae  40 A attached between the mitral valve  40  leaflets and papillary muscles  40 B. Following left ventricular contraction, the aortic valve  44  closes, preventing the backwards flow of blood from the aorta  46  into the heart  20 . 
         [0005]    Unfortunately, one or more of a person&#39;s heart valves  28 ,  32 ,  40 , and  44  can have or develop problems which adversely affect their function and, consequently, negatively impact the person&#39;s health. Generally, problems with heart valves can be organized into two categories: regurgitation and/or stenosis. Regurgitation occurs if a heart valve does not seal tightly, thereby allowing blood to flow back into a chamber rather than advancing through and out of the heart. This can cause the heart to work harder to remain an effective pump. Regurgitation is frequently observed when the mitral valve  40  fails to properly close during a ventricular contraction. Mitral regurgitation can be caused by chordae  40 A stretching, tearing, or rupture, along with other structural changes within the heart. 
         [0006]    Neochordal replacement for stretched or torn chordae is one option to reduce regurgitation. In such a procedure, chords to be replaced are identified and dissected as required. A papillary suture is placed in a papillary muscle corresponding to the dissected chord. The papillary suture may optionally be pledgeted on one or both sides of the papillary muscle. A leaflet suture is also placed in the corresponding mitral valve leaflet. The papillary suture and the leaflet suture may then be tied or otherwise fastened together to create a replacement chord to help support the mitral valve leaflet and prevent regurgitation. 
         [0007]    Unfortunately, while neochordal replacement with ePTFE suture is a proven method of mitral valve repair, technical challenges impede its widespread utilization, especially in minimally invasive cardiac surgery. In particular, it is difficult and time consuming to manipulate a suture needle with forceps through a minimally invasive opening to place the sutures for neochordal replacement. An innovative system that remotely delivers and reliably secures ePTFE suture (or any other desired suture) would dramatically improve the accessibility and clinical outcomes following neochordal implantation. 
         [0008]    Therefore, there is a need for an efficient and precise minimally invasive surgical suturing device that enables surgeons to utilize a minimal invasive entry point for neochordal replacement without sacrificing suturing effectiveness. 
       SUMMARY 
       [0009]    A surgical suturing device is disclosed. The surgical suturing device has a forked guide tip having a plurality of legs, wherein each of the plurality of legs comprises a proximal end, an anatomical variation, and a distal end. A method of chord replacement for a heart valve is also disclosed. A suture is placed in a papillary muscle using a surgical suturing device having a forked guide tip and a papillary suture. A leaflet suture is placed in a leaflet. The papillary suture and the leaflet suture are loaded in a suture fastener from opposite directions in a coaxial fashion. The length of the papillary suture and/or the leaflet suture are adjusted relative to the suture fastener to achieve a desired replacement chord length. The suture fastener is attached to the papillary suture and the leaflet suture to lock the desired replacement chord length. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a cross-sectional view of a heart, illustrating the chambers and valves which function therein. 
           [0011]      FIG. 2  is a perspective view of one embodiment of a surgical suturing device. 
           [0012]      FIG. 3  is an exploded perspective view of the embodied surgical suturing device of  FIG. 2  without the housing or needle actuator. 
           [0013]      FIGS. 4A-4E  show top, front, bottom, left side, and right side views, respectively for one embodiment of a forked guide tip for a surgical suturing device. 
           [0014]      FIG. 5  illustrates the forked guide tip of  FIG. 4B  with one non-limiting embodiment of advantageous and ergonomic dimensions. 
           [0015]      FIGS. 6A-6C  illustrate, in partial cross-sectional view, an example of using one embodiment of a surgical suturing device to place a stitch in tissue, for example, a papillary muscle. 
           [0016]      FIGS. 7A-1  to  7 G illustrate a method of using an embodiment of the surgical suturing device from  FIG. 2  to place a suture in a papillary muscle. 
           [0017]      FIGS. 7H-7I  illustrate a method of coupling a first suture placed in a papillary muscle and a second suture placed in a valve leaflet to each other using a mechanical fastener to replace a chordae tendinae of the heart. 
           [0018]      FIGS. 8 and 9  illustrate alternate embodiments for using the forked guide tip of  FIG. 2  with a pledgeted suture. 
           [0019]      FIGS. 10A-10B  illustrate one embodiment of a forked guide tip for a surgical suturing device for placing a double-pledgeted suture in a papillary muscle. 
           [0020]      FIGS. 11A-11B  illustrate another embodiment of a forked guide tip for a surgical suturing device for placing a double-pledgeted suture in a papillary muscle. 
           [0021]      FIG. 12  illustrates a further embodiment of a forked guide tip for a surgical suturing device. 
       
    
    
       [0022]    It will be appreciated that for purposes of clarity and where deemed appropriate, reference numerals have been repeated in the figures to indicate corresponding features, and that the various elements in the drawings have not necessarily been drawn to scale in order to better show the features. 
       DETAILED DESCRIPTION 
       [0023]      FIG. 2  is a perspective view of one embodiment of a surgical suturing device  48 . The surgical suturing device  48  may have a housing  50  coupled to a shaft  52 . A forked guide tip  54  is coupled to an end of the shaft  52 , opposite from the housing  48 . In some embodiments, the forked guide tip  54  may be continuous with the shaft  52 , rather than a separate assembly piece which is coupled to the shaft  52 . The surgical suturing device  48  also has a needle actuator  56  which is configured to move two needles (not visible in this view) within the forked guide tip  54  as will be described in greater detail below. Depending on the embodiment, some non-limiting examples of suitable shafts include a straight shaft (as illustrated), a curved shaft, a bent shaft, a flexible shaft, and an articulating shaft. Also depending on the embodiment, some non-limiting examples of suitable needle actuators include a handle (as illustrated), a lever, a knob, a slide, a gear, a wheel, a motor, and a solenoid. 
         [0024]    Depending on the embodiment, the forked guide tip  54  may have a suture feed opening  58  which can be used to allow a portion of a suture (not shown in this view) to be loaded into at least a portion of the shaft  52  and potentially into and/or out of the housing  50  for the purpose of simplifying suture management. The forked guide tip  54  may also have one or more cross-supports  60  extending between individual legs  62 ,  64  of the forked guide tip  54 . A distal end  66 ,  68  of each leg  62 ,  64 , respectively, of the forked guide tip  54 , includes a ferrule receiving aperture in alignment with a needle path (not shown in this view, but illustrated farther below) extending from proximal portions  70 ,  72  of the respective forked guide tip legs  62 ,  64 . 
         [0025]    Between the proximal and distal ends  70 ,  66  of the forked guide tip leg  62 , the fork leg  62  includes an anatomical variation  74 . Similarly, the other forked guide tip leg  64  has an anatomical variation  76  between its proximal and distal ends  72 ,  68 . The anatomical variations  74 ,  76  are sized to help guide the forked guide tip  54  onto one or more anatomical structures. In the illustrated embodiment, the anatomical variations  74 ,  76  include arches sized and shaped to fit on a papillary muscle. The openings between the forked legs  62 ,  64  help to provide visibility to tissue when the anatomical variations are positioned by a surgeon operating the device, for example by manipulating the housing  50  with the attached handle  78 . The forked legs  62 ,  64  may also be curved away from a longitudinal axis  80  of the shaft  52  to provide added visibility through the forked area. In a preferred embodiment, the forked legs  62 ,  64  are curved in a concave fashion with respect to the longitudinal axis  80  passing over them as illustrated in  FIG. 2 . 
         [0026]      FIG. 3  is an exploded perspective view of the embodied surgical suturing device of  FIG. 2  without the housing  50  or needle actuator  56 . Two needle guide tubes  82 A,  82 B are inserted into respective openings  84 A,  84 B in multiple supports  86 . The supports  86  may be distributed evenly or unevenly along the guide tubes  82 A,  82 B. The shaft  52  is hollow and the supports  86  are sized to fit into and be supported by the inside of the shaft  52 . The forked guide tip  54  attaches to the distal end  88  of the shaft  52  such that the needle guide tubes  82 A,  82 B align with needle channels (not visible in this view, but discussed below and shown in  FIGS. 4A-4E ) in the forked guide tip  54 . Two needles  90 A,  90 B can be inserted into respective needle guide tubes  82 A,  82 B as illustrated in  FIG. 3 . The supports  86  can also include a suture passage  85  to allow a portion of a suture (not shown in this view), fed into the shaft  52  via the suture feed opening  58 , to extend either partially into the shaft  52  or all the way through the shaft  52  and into the housing  50  (not shown in this view). 
         [0027]      FIGS. 4A-4E  show top, front, bottom, left side, and right side views, respectively for one embodiment of a forked guide tip  54  for a surgical suturing device. The needle channels  92 A,  92 B can be seen passing from the proximal end  94  of the guide tip  54  through the respective legs  62 ,  64  of the forked guide tip  54 . The distal ends  66 ,  68  of the legs  62 ,  64  each have a respective ferrule receiving aperture  96 A,  96 B which will be discussed in more detail further in this specification. The suture feed opening  58  can be seen extending through the forked guide tip  54  towards and all the way through the proximal end  94  of the forked guide tip  54 . The cross supports  60  and the anatomical variations  74 ,  76  discussed previously, are also shown in one or more views of  FIGS. 4A-4E . 
         [0028]      FIGS. 4A-4E  show top, front, bottom, left side, and right side views, respectively for one embodiment of a forked guide tip  54  for a surgical suturing device as described above. 
         [0029]    Various embodiments of a forked guide tip can be manufactured with a wide range of dimensions. As one non-limiting example,  FIG. 5  illustrates a forked guide tip  54  with one non-limiting embodiment of advantageous and ergonomic dimensions. In the embodiment of  FIG. 5 , the legs  62 ,  64  have a substantially concave shape with respect to the longitudinal axis  80  of the shaft. The needle channel  92 A has a proximal channel axis  81  which us approximately  0 . 204  inches above a tip axis  83 . The proximal channel axis  81  and the tip axis  83  are substantially parallel. The portion of the needle channel  92 A corresponding to the proximal channel axis and the portion of the needle channel  92 A corresponding to the tip axis  83  are approximately 1.405 inches apart when measured in a direction parallel to the proximal channel axis  81 . The upper curve R 2  of the legs  62 ,  64  has a radius of approximately 2.775 inches. 
         [0030]      FIGS. 6A-6C  illustrate, in partial cross-sectional view, an example of using one embodiment of a surgical suturing device to place a stitch in tissue, for example, a papillary muscle  108 . Although the side view illustrates only a single leg  62 , it should be understood that there is a second leg not visible in this view that functions similarly to the shown leg. The anatomical variation  74 , in conjunction with the end of the leg  62  near the anatomical variation  74  and the distal end  112  of the device form a tissue bite area  98  which may be placed over the tissue in question (in this example, a papillary muscle  108 ). The distal end  112  has a ferrule receiving aperture  96 A into which a ferrule  100  has been positioned. The ferrule  100  is coupled to a suture  102  which exits from a slot in the distal end  112  of the device. Depending on the embodiment, the end of the suture  102  opposite the ferrule  100  may terminate in a second ferrule (not shown) that is installed in the ferrule receiving aperture of the second leg (which is not visible in this side view. In other embodiments, the end of the suture  102  opposite the ferrule  100  may have nothing attached thereto. For simplicity in the views of  FIGS. 6A-6C , the suture  102  is simply shown as ending at a break line, however, in practice, part of the suture  102  can be fed back through the suture feed opening  58  to help manage the suture  102 . It should be understood that the term “suture”, as used herein, is intended to cover any thread, cable, wire, filament, strand, line, yarn, gut, or similar structure, whether natural and/or synthetic, in monofilament, composite filament, or multifilament form (whether braided, woven, twisted, or otherwise held together), as well as equivalents, substitutions, combinations, and pluralities thereof for such materials and structures. 
         [0031]    With reference to  FIG. 6A , a needle  90 A is positioned within needle channel  92 A in a refracted position. The needle  90 A has a ferrule-engaging tip  106  which is also configured to be able to penetrate tissue  108 . In  FIG. 6B , an actuator (not shown), coupled to the needle  90 A, moves the needle  90 A in a distal direction  110 , causing the ferrule engaging tip  106  to penetrate the tissue  108  in the tissue bite area  98  as it moves across the tissue bite area  98  and then engages the ferrule  100  held by the ferrule receiving aperture  96 A. In  FIG. 6C , the actuator moves the needle  90 A in a proximal direction  114 , causing the ferrule-engaging tip  106  and the ferrule  100  which is attached to it to be pulled back across the tissue bite area  98  and through the tissue  108 . A portion of the suture  102  is also pulled back through the tissue  108 . 
         [0032]    The utility of such a device and its equivalents is further illustrated with respect to the perspective views of  FIGS. 7A-1  to  7 G which better show the dual needles  90 A,  90 B in action.  FIGS. 7A-1  to  7 G illustrate a method of using an embodiment of the surgical suturing device from  FIG. 2  to place a suture  102  in a papillary muscle  108 .  FIG. 7A-1  schematically illustrates a surgical situation. Minimally invasive access has been gained to the left ventricle  42  of the heart. Healthy chordae  40 A are coupled between a papillary muscle  40 B and leaflets of the mitral valve  40 . A pathologic chord has been removed from another papillary muscle  108  and the suturing device is ready to be used. For convenience the shaft, handle, and actuator of the surgical device are not illustrated in these views. 
         [0033]    The suturing device and the papillary muscle  108  may be seen more clearly in the enlarged view of  FIG. 7A-2 . As before, the device has a forked guide tip  54  having first and second legs. The first leg has a proximal end  70 , an anatomical variation  74 , and a distal end  66 . The second leg has a proximal end  72 , an anatomical variation  76 , and a distal end  68 . The device also has a viewing area  115  defined at least in part by the anatomical variations  74 ,  76  of the forked guide tip  54 . A first needle  90 A, having a suture engaging tip  106 A, resides in the first leg in a refracted position. A second needle  90 B, having a suture engaging tip  106 B, resides in the second leg in a retracted position. A first ferrule  100 A is held in the distal end  66  of the first leg, while a second ferrule  100 B is held in the distal end  68  of the second leg. A suture  102  runs from the first ferrule  100 A, through a first hole in a pledget  116 , back into the suture feed opening  58 , reverses back out of the suture feed opening  58 , through a second hole in the pledget  116 , and to the second ferrule  100 B. In this embodiment, the pledget  116  rests on part of one or more of the anatomical variations  74 ,  76 . In other embodiments, the pledget  116  may rest on other portions of the device. The pledget  116  has a first face  118  where the end of suture  102  exit the pledget  116  to couple to the ferrules  100 A,  100 B. 
         [0034]    As illustrated in  FIG. 7B , the tissue bite area  98  is placed over the papillary muscle  108 . This can advantageously be done by looking through the viewing area  115  from  FIG. 7A-2 . As illustrated in  FIG. 7C , the first and second needles  90 A,  90 B are moved by the actuator (not shown) in a distal direction  110 , causing the ferrule engaging tips  106 A,  106 B to penetrate the tissue  108  in the tissue bite area  98  as they move across the tissue bite area  98  and then engage the respective ferrules  100 A,  100 B held in the distal ends  66 ,  68 . In  FIG. 7D , the actuator (not shown) moves the needles  90 A,  90 B in a proximal direction  114 , causing the ferrule-engaging tips  106 A,  106 B and the respective ferrules  100 A,  100 B which are attached to them to be pulled back through the tissue  108 . Portions of the suture  102  are also pulled back through the tissue  108 . As the suture  102  is pulled through the tissue  108 , the pledget  116  may start to pivot  122  off the end of the device so that the first side  118  of the pledget  116  starts to face the tissue  108 . A second side  120  of the pledget  116  is located opposite the first side  118  of the pledget  116 . As the suture  102  is pulled back through the tissue  108 , the suture  102  starts to play out of the suture feed opening  58 . 
         [0035]    In  FIG. 7E , the suturing device is pulled away  124  from the papillary muscle  108  and the suture  102  may exit the suture feed opening  58  completely. As illustrated in  FIG. 7F , the device may continue to be withdrawn  126  such that the first side of the pledget  118  contacts the tissue  108  as the approximate midpoint  127  of the suture  102  is pulled against the second side  120  of the pledget  116 . The ferrules  100 A,  100 B held by the device may then be removed from the ends of the suture  102 . While other embodiments may not use a pledget  116 , the pledget does provide an advantageous interface to help protect the suture stitch from pulling through the tissue. In fact, in some embodiments, the suture ends passing out of the tissue  108  may be threaded through a second pledget  128  so both sides of the papillary muscle are pledgeted as illustrated in  FIG. 7G . 
         [0036]      FIGS. 7H-7I  illustrate a method of coupling a first suture  102  placed in a papillary muscle  108  (for example, as illustrated in the method of  FIGS. 7A-2  to  7 G) and a second suture  130  placed in a valve leaflet  132  to each other using a mechanical fastener to replace a chordae tendinae of the heart.  FIG. 7H  simply shows the second suture  130  after it has been stitched through a leaflet  132  of the mitral valve  40 . Those skilled in the art will be familiar with a variety of ways to create this stitch of the second suture  130 .  FIG. 7I  illustrates a mechanical fastener  134  which has been fastened to hold a first set of suture ends  136  of the first suture  102  which have been passed up through the mechanical faster  134 . The mechanical fastener  134  also holds a second set of suture ends  138  of the second suture  130  which have been passed down through the mechanical fastener  134 . One suitable method for fastening the two sets of suture ends together in this fashion is disclosed in U.S. Patent Application Publication 2014/0276979, published Sep. 18, 2014 for U.S. patent application Ser. No. 13/840,481 filed Mar. 15, 2013, the entirety of which is hereby incorporated by reference. 
         [0037]      FIGS. 8 and 9  illustrate alternate embodiments for using the forked guide tip of  FIG. 2  with a pledgeted suture. The forked guide tip  140  embodiment of  FIG. 8  is similar to previous embodiments, except for the pledget  116  which is rested against a proximal side of the anatomical variations  74 ,  76 . In this embodiment, the viewing area  142  is defined between the forked legs  62 ,  64  and the proximal portions of the anatomical variations  74 ,  76 . The forked guide tip embodiment of  FIG. 9  is similar to previous embodiments, except for the pledget  116  which is rested against the suture feed opening  58 . In this embodiment, the viewing area  146  is potentially much larger without the pledget  116  blocking a portion of the view. 
         [0038]      FIGS. 10A-10B  illustrate one embodiment of a forked guide tip  148  for a surgical suturing device for placing a double-pledgeted suture in a papillary muscle. The forked guide tip  148  is similar to previous embodiments in that it includes a first pledget  150  through which the suture  102  is routed before reaching the ferrules in the distal leg ends  66 ,  68 . In this embodiment, however, a second pledget  152  is held in a pledget holder  154  adjacent to the tissue bite area  98 . The second pledget  152  is preferably positioned so that the pledget holes are in alignment with the openings in the legs  62 ,  64  from which the needles  90 A,  90 B will extend. As illustrated in  FIG. 10B , the needles  90 A,  90 B may be advanced  156  out of the legs, through the second pledget  152 , across the tissue bite area  98  and into engagement with the ferrules. When the ferrules and suture are pulled back through the tissue bite area, they will then be pulled through the second pledget, thereby double-pledgeting the tissue sutured by the device. 
         [0039]      FIGS. 11A-11B  illustrate another embodiment of a forked guide tip  158  for a surgical suturing device for placing a double-pledgeted suture in a papillary muscle. The forked guide tip  158  is similar to the embodiment of  FIG. 10A , except that it also includes pledget hole stabilizers  160 A,  160 B on the tissue gap  98  side of the pledget holder  154 . Since the needles  90 A,  90 B may tend to push the second pledget  152  out of the pledget holder  154  in some embodiments as they pass through the second pledget  152 , the pledget hole stabilizers  160 A,  160 B may help prevent the movement of the second pledget away from the needles  90 A,  90 B. The pledget hole stabilizers  160 A,  160 B may also enable the use of a second pledget  152  which does not have pre-formed holes, since the needles  90 A,  90 B will be able to pierce the second pledget as it held in place by the pledget holder  154  and the pledget hole stabilizers  160 A,  160 B. As illustrated in  FIG. 11B , the needles  90 A,  90 B may be advanced  162  out of the legs  62 ,  64 , through the second pledget  152 , through the pledget hole stabilizers  160 A,  160 B, across the tissue bite area  98  and into engagement with the ferrules held in the distal ends  66 ,  68 . When the ferrules and suture are pulled back through the tissue bite area  98 , they will then be pulled through the second pledget, thereby double-pledgeting the tissue sutured by the device. 
         [0040]      FIG. 12  illustrates a further embodiment of a forked guide tip  164  for a surgical suturing device. The embodiment of  FIG. 12  is similar to previous embodiments, particularly the embodiment of  FIG. 2 , however it does not include any cross supports. The forked guide tip  164  has first and second legs  166 ,  168  which are coupled to their respective distal ends  66 ,  68  by respective first and second anatomical variations  170 ,  172 . In this embodiment, a viewing area  174  is defined by the combination on one side of the first leg  166 , the first anatomical variation  170 , and the first distal end  66  and by the combination on the other side of the second leg  168 , the second anatomical variation  172 , and the second distal end  68 . 
         [0041]    Various advantages of a minimally invasive surgical suturing device for papillary muscles and methods thereof have been discussed above. Embodiments discussed herein have been described by way of example in this specification. It will be apparent to those skilled in the art that the forgoing detailed disclosure is intended to be presented by way of example only, and is not limiting. Various alterations, improvements, and modifications will occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested hereby, and are within the spirit and the scope of the claimed invention. Additionally, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claims to any order, except as may be specified in the claims. Accordingly, the invention is limited only by the following claims and equivalents thereto.