Abstract:
Medical devices and related methods for closing a perforation in a bodily wall The medical device generally includes a suture having opposing first and second ends and a set of visceral staples. Each visceral staple includes a base and two tines connected to the base, the tines spaced apart two define a slot therebetween. The slot slidably receives the suture therein. Each visceral staple is attached to the bodily wall adjacent the periphery of the perforation. The ends of the suture are tensioned to reduce the distance between the visceral staples and compress the bodily wall around the perforation. The ends of the suture are secured to maintain the compression of the bodily wall and close the perforation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/956,580, filed on Aug. 17, 2007, entitled “VISCERAL STAPLES FOR PURSE-STRING CLOSURE OF PERFORATIONS” the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to visceral stapes for closing perforations in tissue. 
       BACKGROUND OF THE INVENTION 
       [0003]    Perforations in the walls of internal organs and vessels may be naturally occurring, or formed intentionally or unintentionally. In order to permanently close these perforations and allow the tissue to properly heal, numerous medical devices and methods have been developed employing sutures, adhesives, clips, and the like. One class of such devices is commonly referred to as suture staples or visceral staples. In certain applications, the staples themselves hold the edges of a perforation together, and in others they are used with sutures to draw the perforation closed. Visceral staples of the latter type have been successfully used in closing perforations, but are not without their drawbacks. 
         [0004]    For example, when a series of staples are placed around a perforation, all of the individual sutures connected to the staples must be collected and connected together. It can often be difficult to properly tension each of the individual sutures to ensure proper approximation of the tissue around the perforation and complete closure thereof. This is especially critical within the gastrointestinal tract, where the travel of bacteria-laden fluids outside of the tract may cause unwanted and sometimes deadly infection. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The present invention provides medical devices and related methods for closing a perforation in a bodily wall in a manner that is simple and reliable, while at the same time gives increased versatility and control over perforation closure. One embodiment of a medical device, constructed in accordance with the teachings of the present invention, generally comprises a suture having opposing first and second ends and a set of two or more visceral staples. Each visceral staple includes a base and two tines connected to the base. The tines are spaced apart to define a slot therebetween. The suture is slidably received within the slot and between the base and the bodily wall. The first and second ends of the suture are capable of being independently tensioned for translating the suture relative to each of the visceral samples enclosing the perforation. According to more detailed aspects of this embodiment tensioning of the suture reduces the distance between the visceral samples to close the perforation in a purse-string fashion. The tensioning of the suture causes compression of the bodily wall around the perforation. Each visceral staple includes barbs on the two tines, the barbs being spaced a distance away from the base such that the base is positioned near the bodily wall, thereby containing the suture immediately adjacent the bodily wall. 
         [0006]    Another embodiment of a medical device, constructed in accordance with the teachings of the present invention, generally comprises a suture, a set of visceral staples, and a delivery catheter. Each visceral staple includes a base and two tines connected to the base, the tines being spaced apart to define a slot therebetween. The delivery catheter defines a lumen sized to receive the visceral staples. A distal end of the delivery catheter defines a pair of circumferentially spaced apertures in communication with the lumen. The suture passes through the pair of apertures and the lumen. The visceral staples are arranged in the delivery catheter such that distal translation of a visceral staple through the distal end of the delivery catheter causes the suture to enter the slot. 
         [0007]    According to more detailed aspects of this embodiment of the medical device, as the visceral staples are sequentially placed the suture may be spooled in several manners. In one manner, the first end of the suture is fixed relative to the catheter such that the second end of the suture is spooled toward the apertures as a set of visceral staples are distally translated relative to the catheter and connected to the bodily wall. Here, the second end of the suture is preferably tensioned during distal translation of a visceral staple through the distal end of the delivery catheter. In another manner, the first and second ends of the suture are translatable relative to the catheter such that the first and second ends of the suture are spooled towards the apertures as a set of visceral staples are distally translated relative to the catheter and connected to the bodily wall. Here, both the first and second ends of the suture may be tensioned during distal translation of a visceral staple through the distal end of a delivery catheter. Preferably, the lumen of the delivery catheter is sized to receive each of the visceral staples in series. Each base includes a second slot sized to receive the two tines of the adjacent staple, thereby providing compact containment of the visceral staples. The two tines of each staple include a barb spaced away from a distal end of the staple, the barb not fitting within the second slot when the two tines are positioned within the slot. 
         [0008]    According to another embodiment, a staple is provided for closing a perforation in a bodily wall in accordance with the teachings of the present invention. The staple generally comprises a base and two tines connected to the base. The tines are spaced apart to define a slot therebetween. Each of the tines defines a first barb and a second barb. The first and second barbs are longitudinally spaced apart, and further the first and second barbs are circumferentially spaced apart. According to more detailed aspects, the first barb extends radially inwardly, and the second barb extends laterally. The staple may further comprise a third barb longitudinally spaced from the first barb. The third barb also preferably extends laterally and is longitudinally aligned with the second barb. The base, the two tines and the bodily wall define a passageway receiving a suture, and the width of the passageway is preferably about equal to the diameter of the suture. This staple is preferably radiused where the two tines meet the base to provide a smooth surface for translating the suture relative to the staple. 
         [0009]    Yet another embodiment, in accordance with the teachings of the present invention, provides a method for closing a perforation in a bodily wall using a set of visceral staples operably connected to a suture. The method generally comprises the steps of attaching each visceral staple to a proximal side of the bodily wall adjacent the periphery of the perforation. The ends of the suture are tensioned to reduce the distance between the visceral staples and compress the bodily wall around the perforation. The ends of the suture are secured to maintain the compression of the bodily wall enclosed to perforation. According to more detailed aspects, the attaching step preferably includes positioning the set of visceral staples around the perforation to permit closing of the perforation in a purse string fashion. The attaching step may include positioning the set of visceral staples sequentially around the perforation in a semi-annular or annular shape, or alternatively may comprise positioning the set of visceral anchors sequentially on opposite sides of the perforation. The tensioning step preferably includes independently tensioning the ends of the suture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings: 
           [0011]      FIG. 1  is a perspective view of a visceral staple constructed in accordance with the teachings of the present invention; 
           [0012]      FIG. 2  is a plan view of the visceral staple depicted in  FIG. 1 ; 
           [0013]      FIG. 3  is a side view of the visceral staple depicted in  FIG. 1 ; 
           [0014]      FIG. 4  is a perspective view of a medical device employing the visceral staples depicted in  FIGS. 1-3 ; 
           [0015]      FIG. 5  is a perspective view similar to  FIG. 4 , partially cut away to illustrate the visceral staples of  FIGS. 1-3 ; 
           [0016]      FIGS. 6-12  are plan views and cross-sectional view illustrating a method of closing a perforation utilizing the visceral staples and medical device depicted in  FIGS. 1-5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Turning now to the figures,  FIGS. 1-3  depict a visceral staple  20  constructed in accordance with the teachings of the present invention. The staple  20  generally includes a base  22  and two tines  24 ,  26  connected to the base  22 . The tines  24 ,  26  are laterally spaced apart to define a slot  28  therebetween. The visceral staple  20  is utilized to connect a suture  60  to tissue  80 , as will be later described herein with reference to  FIGS. 6-12 . Generally, the visceral staples  20  receive the suture  60  within the slot  28 , and provide for translation of the suture  60  within the slot  28 . In this manner, a set of staples  20  may be utilized to form a purse-string type closure, as will also be discussed in further detail herein. Each staple  20  is preferably formed of a material such as stainless steel, titanium, nitinol or other metals/alloys, although various ceramics or plastics can be employed, such as polycarbonates (PC), polyamides including Nylon (TM), polytetrafluorethylenes (e.g. PTFE and EPTFE), polyethylene ether ketones (PEEK), polyvinylchlorides (PVC), polyimides, polyurethanes, and polyethylenes (high, medium or low density), including multi-layer or single layer constructions with or without reinforcing elements. Bioresorbable polymers, such as polylactide (PLA), polyglycolide (PGA), poly-L-lactide (PLLA), poly-DL-lactide (PDLLA) and their copolymers (e.g., PGLA, PLGA), and the like may also be used for the staples  20  such that they would degrade away after the tissue has healed. 
         [0018]    Each of the tines  24 ,  26  includes a first barb  30 , a second barb  32  and a third barb  34 . The first barb  30  is located at the distal end of the visceral staple  20 , while the second and third barbs  32 ,  34  are longitudinally spaced apart from the first barb  30 . The tines  24 ,  26  and first barb  30  generally include a sharp distal edge  36  for piercing tissue. The first barb  30  also extends radially inwardly to define proximal facing shoulder  38 . The shoulder  38  serves to prevent backward migration of the visceral staple  20  from the tissue. The second and third barbs  32 ,  34  extend laterally from the tines  24 ,  26 . It can be seen that the second and third barbs  32 ,  34  are circumferentially spaced from the first barb  30 . The second and third barbs  32 ,  34  are longitudinally aligned along the first and second tines  24 ,  26 , and define proximally facing shoulders  40 ,  42 , respectively, which also serve to prevent backward migration of the visceral staple  20  from tissue. 
         [0019]    In order to accommodate the relative translation between the suture  60  and staple  20 , the portions of the staple  20  where the tines  24 ,  26  meet the base  22  have a radiused portion  44  to provide for smooth relative translation. Preferably, the width of the slot  28  is about equal to the diameter of the suture  60 , or a few times (e.g., 5 times) larger than the diameter of the suture  60 . The base  22  of the visceral staple  20  also includes a second slot  46  which is sized to receive the distal ends of the tines  24 ,  26  of an adjacent visceral staple  20 , as shown in  FIG. 5 . The receipt of adjacent tines  24 ,  26  in the second slot  46  allows for force and torque transmission through a set of multiple staples  20 . Many variations of this interrelation provided by second slot  46  are envisioned; e.g. the base  22  may include a tab or other projection that is sized to fit between the tines  24 ,  26  of adjacent staples  20 , and different socket-like arrangements can be employed between multiple staples  20  and any pusher used to advance the staples, as will be described in detail below. 
         [0020]    It will be recognized by those skilled in the art that the tines and barbs may take many different shapes and constructions. For example, the tines may have a hollow construction, or a solid construction as shown. While two tines have been depicted, more than two tines may be readily employed in a visceral staple in accordance with the teachings of the present invention. The barbs may be formed by any resistant features, such as flat or angled surfaces, expandable surfaces or structures, or any structure that increases the force required for the tines to translate back out of the tissue. 
         [0021]    Turning now to  FIGS. 4 and 5 , a medical device  50  for closing a perforation in a bodily wall will now be discussed. Generally, the medical device  50  includes a plurality of visceral staples  20 , a delivery catheter  52 , and a suture  60 . Although two visceral staples  20   a ,  20   b , have been depicted in  FIG. 5 , any number of staples  20  may be employed in conjunction with the present invention. The delivery catheter  52  defines a lumen  54  sized to receive a set (i.e. two or more) of visceral staples  20   a ,  20   b . The visceral staples  20   a ,  20   b  are arranged in series within the lumen  54  as shown in  FIG. 5 . The relative position of the staples  20   a ,  20   b  is maintained by the distal ends of tines  24 ,  26  being received within the second slot  46  defined by the base  22  of adjacent visceral staples  20 . 
         [0022]    A distal end  56  of the delivery catheter  52  includes a pair of circumferentially spaced apertures  58 . The apertures  58  are preferably spaced apart about 180 degrees, although any degree of spacing may be employed. The suture  60  is strung through the apertures  58  such that the suture  60  extends through the lumen  54  of the delivery catheter  52 . Accordingly, distal translation of a visceral staple  20  through the distal end  56  of the catheter  52  causes the suture  60  to pass between the tines  24 ,  26  and enter the slot  28  of the visceral staple  20 . A pusher  70  is slidably received within the lumen  54  of the catheter  52 , and is used to distally translate the set of visceral staples  20   a ,  20   b . It will be recognized that the pusher  70  may take many forms, including solid rods, tubular cannulas or catheters having sufficient strength to transmit force from the medical professional (outside the body) to the visceral staples  20 . Preferably, the pusher  70  includes a tab  72  which is sized to be received within the second slot  46  of the most proximal visceral staple  20   b . In this manner, the pusher  70  may be used to both distally translate the visceral staples  20   a ,  20   b , and also circumferentially rotate the staples to properly orient the tines  24 ,  26  relative to the suture  60 . 
         [0023]    It can also be seen that the second and third barbs  32   b ,  34   b  of visceral staple  20   b  press against a proximal end of the base  22   a  of the first visceral staple  20   a . The longitudinal spacing of barbs  30   b  and barbs  32   b ,  34   b  relative to the size of the second slot  46   a  prevents the sharp edge  36   b  of the visceral staple  20   b  from being blunted or otherwise deformed by being pressed against the first visceral staple  20   a . At the same time, force transmission is still provided through the pusher  70  to the second visceral staple  20   b  and to the first visceral staple  20   a . It will be recognized by those skilled in the art that the medical device  50  may simply comprise the suture  60  and a set of visceral staples  20   a ,  20   b , etc., and that any other delivery device may be employed in accordance with the teachings of the present invention. 
         [0024]    As subsequent visceral staples  20  are placed within tissue, additional suture material may be spooled from either the first end  61  or second end  62  of the suture, or from both ends. Additionally, one of the suture ends  61 ,  62  could be prevented from spooling, such as by tying a knot therein to prevent that end from passing through the holes  58  in the delivery catheter  52 . For example, in  FIG. 5  the first end  61  of the suture  60  includes a knot  63 , whereby spooling of additional suture  60  is forced to occur from the second end  62 . The spooling of suture  60  will be discussed in more detail hereinbelow. 
         [0025]    Turning now to  FIGS. 6-12 , a method of closing a perforation in tissue will now be described. As shown in  FIG. 6 , tissue  80  will generally include a perforation  82  that is desired to be closed. Accordingly, the medical device  50  will be navigated to a location within the body proximate the perforation  82 . As previously discussed, the medical device  50  generally includes the catheter  52 , a suture  60 , and a set of visceral staples  20 . Preferably, an endoscope (not shown) is utilized to access the area, and the medical device  50  may be delivered through the working channel of the endoscope. Alternatively, other visualizing devices, such as catheter based systems, other fiber optic devices, or techniques such as fluoroscopy or ultrasound may be employed in parallel with the medical device  50 . 
         [0026]    As shown in  FIG. 7 , the first visceral staple  20   a  is placed into the tissue  80  by distally translating the pusher  70  ( FIG. 5 ) while the delivery catheter  52  is maintained in close proximity to the tissue  80 . As previously discussed, the suture  60  will be maintained within the slot  28  of the visceral staple  20   a , while being translatable relative thereto. That is, a passageway is formed between the base  22 , tines  24 ,  26  and the tissue  80 , the passageway slidably receiving the suture  60  when the staple  20  is placed in the tissue  80 . Notably, through design of the staples&#39; barbs  30 ,  32 ,  34 , the base  22  maintains the suture  60  immediately adjacent the tissue  80  to improve perforation closure. Preferably, the first barbs  30  are spaced a distance from the base  22  about equal to or less than the thickness of the tissue  80 . As such, different sized staples  20  may be designed for different applications. 
         [0027]    Next, the delivery catheter  52  is moved away from the first visceral staple  20   a  to a second location. As one example, when the first end  61  includes a knot  63 , the suture  60  will be spooled from the second end  62  thereof as is shown in  FIG. 8 . Preferably, the second end  62  is tensioned in order to maintain a tautness of the suture  60  within the lumen  54  at the distal end of catheter  52 . The tensioning may occur by hand or by a spooling device. The device  50  may be rotated as shown in  FIG. 8  to position the aperture  58  that is opposite knot  63  furthest away from the placed staple  20   a , to ensure to suture  60  crosses the lumen of catheter  52  for engagement by subsequent staples  20   b . It will also be seen that when knot  63  is not present, the suture  60  may be spooled from either or both of the first and second ends  61 ,  62 , in which case both ends  61 ,  62  are maintained in some tension to assist with the suture  60  entering the slot  28  of the distal-most staple  20  as it is translated through the distal end  56  of the delivery catheter  52 . 
         [0028]    The process of placing a second visceral staple  20   b  is again accomplished through the distal translation of pusher  70 . The above-mentioned steps are repeated to sequentially place a set of visceral staples  20   a ,  20   b ,  20   c ,  20   d  around the perforation  82  in a annular or semi-annular configuration, as shown in  FIG. 9 . The suture  60  and both of its ends  61 ,  62  are translatable relative to each of the visceral staples  20   a ,  20   b ,  20   c ,  20   d , whereby the ends  61 ,  62  may be tensioned, together or independently, in order to draw the visceral staples  20 ,  20   b ,  20   c ,  20   d  towards each other and close the perforation  82  in a purse-string fashion, as shown in  FIGS. 10 and 11 . The ends  61 ,  62  of the suture  60  are fixed, such as by using a suture lock  68 , or by using other devices or techniques known in the art, such as simply typing the ends  61 , 62  of the suture  60 . As best seen in  FIG. 11 , the perforation  82  is therefore closed by drawing the edges of the tissue  80  around the perforation  82  into close proximity to promote healing. Although positioning of the visceral staples  20  has been shown in a semi-annular or annular shape in  FIGS. 9 and 10 , it will be recognized that numerous formations may be employed, such as a zig-zag formation where the visceral anchors  20  are sequentially spaced on opposite sides of a perforation  82 , such as is shown in  FIG. 12 . 
         [0029]    It will be recognized that the embodiments of the devices, systems and methods disclosed herein may be used with many types of tissue defects, and thus as used herein the term “perforation” includes all other tissue defects including tears, resected mucosal sites, bleeding vessels, sampled or biopsied tissue and other tissue voids which don&#39;t extend entirely through the tissue or bodily wall, as well as protrusions such as polyps, growths, hernias, aneurysms and the like. 
         [0030]    The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.