Abstract:
A surgical fastener for fastening tissue. The fastener includes a first piece of sheet material formed to have a generally planar base and an elongate needle portion extending upward from the base. The fastener includes a second piece of sheet material formed to have a generally planar base and an elongate needle portion extending upward from the base. The second piece of sheet material is pivotally connected to the first piece of sheet material.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a surgical fastener, and more particularly to a surgical fastener having sheet metal components. 
     Gastroesophageal reflux disease or persistent heartburn is caused by an improper relaxation of the lower esophageal sphincter, allowing acidic stomach contents to travel into the esophagus. If left untreated, chronic reflux may cause esophageal stricture, bleeding ulcers, perforation, and scarring. Continued reflux may lead to Barrett&#39;s esophagus, involving changes in the esophageal cells and possibly leading to cancer. Antacids and proton pump inhibitors are initially used to treat this condition. If these treatments are unsuccessful, surgical intervention is often recommended. 
     One interventional surgical method is known as Nissen fundoplication. This procedure involves wrapping a fundus of the stomach around the lower end of the esophagus and fastening it in place to make the lower esophageal sphincter less compliant. Traditionally, this procedure was accomplished by open surgery using sutures to secure the plicated fundus of the stomach around the esophagus without penetrating the stomach. More recently, laparoscopic Nissen procedures have been used. In some laparoscopic procedures, surgical fasteners are used with an endoscopic applicator. Several different fastener designs have been developed. Some of these designs include a two piece fastener. A first of these pieces includes a base having two straight elongate needles extending perpendicularly outward from the base generally parallel to each other. A second piece includes a receiver element having openings positioned for receiving the needles of the first piece and a lock for holding the needles in place once received in the openings. In use, tissue is gathered, the needles of the first piece are pushed through the gathered tissue and the openings of the second piece to hold the tissue and fastener in place. U.S. Pat. No. 7,033,378, entitled “Surgical Fastener, Particularly for the Endoluminal Treatment of Gastroesophageal Reflux Disease (GERD)” and issued on Apr. 25, 2006, which is hereby incorporated by reference, discloses one such fastener and an applicator used with this fastener. 
     Although prior examples of tissue fasteners work well for their intended purpose, they can be improved by reducing their cost. Current designs require molding some components and a complex assembly process. There is a need for a fastener made by less expensive processes. 
     SUMMARY OF THE INVENTION 
     Briefly, in one aspect the present invention includes a surgical fastener for fastening tissue. The fastener comprises a first piece of sheet material formed to have a generally planar base and an elongate needle portion extending upward from the base. Further, the fastener comprises a second piece of sheet material formed to have a generally planar base and an elongate needle portion extending upward from the base. The second piece of sheet material is pivotally connected to the first piece of sheet material. 
     In another aspect, the present invention includes a surgical fastener for fastening tissue. The fastener comprises a base formed from sheet material having at least two pairs of opposing clips formed therein. Further the fastener includes a first latch slideably received between a first pair of the opposing clips and a second latch slideably received between a second pair of the opposing clips. 
     Other features of the present invention will be in part apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective of a surgical fastener of the present invention; 
         FIG. 2  is a perspective of a male piece of the fastener of  FIG. 1  shown in a deployed position; 
         FIG. 3  is a perspective of the male piece shown in a collapsed position; 
         FIG. 4  is a plan of one leaf of the male piece prior to forming; 
         FIG. 5  is a perspective of the leaf prior to assembly; 
         FIG. 6  is a cross section of a needle of the leaf of  FIG. 5  taken through line  6 - 6 ; 
         FIG. 7  is a cross section of a needle of an alternate design; 
         FIG. 8  is a separated perspective of a female piece of a first embodiment of the present invention; 
         FIG. 9  is a cross section of the female piece of the first embodiment showing latches in a latched position; 
         FIG. 10  is a cross section of the female piece of the first embodiment showing latches in an unlatched position; 
         FIG. 11  is a cross section of a female piece of a second embodiment; 
         FIG. 12  is a detail perspective of a portion of a latch and a needle of one embodiment; and 
         FIG. 13  is a perspective of a portion of a device for fastening the fastener to tissue. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and in particular to  FIG. 1 , a two-piece fastener of the present invention is designated in its entirety by the reference numeral  20 . The fastener  20  includes a male piece, generally designated  22 , and a female piece, generally designated  24 . 
     As shown in  FIGS. 2 and 3 , the male piece  22  includes a base, generally designated by  30 , comprising two leaves  32 ,  34  joined by a hinge pin  36  so the male piece can move between a deployed position as shown in  FIG. 2  and a collapsed position as shown in  FIG. 3 . Two elongate needles or posts  38 ,  40  extend upward from the base  30 . Each of the needles  38 ,  40  is integrally formed with the corresponding leaf  32 ,  34 . Although the needles  38 ,  40  are adapted to pierce tissue, in one embodiment they have slightly rounded tips  42 ,  44  so they displace tissue rather than cut tissue. The hinge pin  36  is adapted to bias the male piece  22  toward the collapsed position shown in  FIG. 3  so that if the male piece becomes detached from the female piece  24  while in the patient, the male piece collapses to the collapsed position so it is less likely to pierce tissue if it moves through the body. As will be apparent to those skilled in the art, the leaves  32 ,  34  of the male piece may be formed from sheet material. The shape of the leaves  32 ,  34  may be identical. The shape of the leaves  32 ,  34  prior to being formed as shown in  FIG. 2  will be apparent to those skilled in the art. Although the needles  38 ,  40  may have other dimensions without departing from the scope of the present invention, in one embodiment each needle has a length between about 0.4 inch and about 0.6 inch and a maximum width of between about 0.05 inch and about 0.06 inch. Although the base  30  may have other dimensions without departing from the scope of the present invention, in one embodiment the base, when in the fully deployed position shown in  FIG. 2 , has a length of between about 0.4 inch and about 0.7 inch and a width of between about 0.2 inch and about 0.4 inch. 
     In an alternate embodiment, each leaf  32 ,  34  of the male piece  22  is formed from sheet material  50  having a shape similar to that shown in  FIG. 4 . A central arm  52  of the sheet material  50  is bent so it extends perpendicular to the remainder of the material as shown in  FIG. 5  so it forms a needle. Ends of arms  54 ,  56  extending along each side of the sheet material  50  are rolled to form knuckles  58  through which a hinge pin ( FIG. 2 ) may be inserted to join the first leaf  32  to a similarly formed leaf  34 . As shown in  FIG. 6 , the needle (e.g., needle  38 ) may be bent so it has a curved cross section to provide the needle with additional rigidity.  FIG. 7  shows an alternate cross-sectional needle shape. It is envisioned that the needle may have other cross-sectional shapes (e.g., a shallow V-shape, not shown) without departing from the scope of the present invention. Although the male piece  22  may be made of other materials without departing from the scope of the present invention, in one embodiment the male piece is made from titanium sheet material having a stock thickness of between about 0.010 inch and about 0.020 inch. Because the male piece  22  is formed using conventional manufacturing techniques, they will not be described in further detail. 
       FIG. 8  illustrates a female piece  24  separated so that each component is visible. The female piece  24  includes a cover  70  that fastens to a base  72 . The base  72  includes openings  74  into which the needles  38 ,  40  of the male piece  22  are inserted when the male piece is joined to the female piece  24 . A clip  76  is formed on each side of the base  72  adjacent the openings  74 . Two clasps  78  are slideably fastened to the base  72  so that each clasp is held against the base by one pair of opposing clips  76 . Each clasp  78  includes a V-shaped opening  80  that releasably secures the needles  38 ,  40  in position when they are inserted in the openings  74  in the base  72  as shown in  FIG. 1 . As further illustrated in  FIG. 8 , each clasp  78  includes an upward extending flange  82  that may be grasped to move the clasps from the latched position as shown in  FIG. 9  to the unlatched position as shown in  FIG. 10  to disengage the clasps from the needles  38 ,  40  to allow the male piece  22  to be separated from the female piece  24 . A spring  84  is captured between the flanges  82  of the clasps  78  to bias the clasps toward the latched position. The cover  70  includes openings  86  for providing access to the flanges  82  of the clasps  78 . Although the female piece  24  may be made of other materials without departing from the scope of the present invention, in one embodiment the female piece is made entirely from titanium sheet material having a stock thickness of between about 0.010 inch and about 0.020 inch. Although the female piece  24  may have other dimensions without departing from the scope of the present invention, in one embodiment the fully assembled female piece has a length of between about 0.4 inch and about 0.7 inch and a width of between about 0.2 inch and about 0.4 inch. Because the female piece  24  is formed using conventional manufacturing techniques, they will not be described in further detail. The cover  70  is held in position on the base  72  using conventional techniques such as brazing, adhesive bonding or by an interference fit. 
     In an alternate embodiment illustrated in  FIG. 11 , the clasps are joined by a curved band  90  so the clasps  72  are formed as one piece. In this alternate embodiment, the band  90  biases the clasps toward the latched positioned and thus replaces the spring. As shown in  FIG. 12 , each needle (e.g., needle  38 ) includes notches  92  on opposite sides adjacent its respective tip. As will be appreciated by those skilled in the art, the notches  92  engage a corresponding opening  80  at the outer end of the respective clasp  78  to prevent the needle of the male piece  22  from separating inadvertently from the female piece  24 . 
       FIG. 13  illustrates an instrument, generally designated by  100 , for installing the fastener  20  of the present invention into tissue T. The instrument  100  is generally conventional and operates like the instrument described in U.S. Patent Publication No. 2004/0059354 except that one jaw  102  of the instrument includes stabilizing pins  104  that engage the needles  38 ,  40  of the male piece  22  to hold the male piece in the deployed position so its needles can engage the female piece  24 . The jaw  102  also includes a recess  106  for receiving the knuckles  58  of the male piece  22 . Because the instrument  100  is conventional in other aspects, it will not be described in further detail. 
     Although the fastener  20  may have other dimensions without departing from the scope of the present invention, in one embodiment the fastener sized for passing through a patient&#39;s esophagus. For example, in one embodiment the male piece  22  has a maximum dimension of between about 0.4 inch and about 0.7 inch when in the collapsed position. In this embodiment, the female piece  24  has a length of between about 0.4 inch and about 0.7 inch, a width of between about 0.2 inch and about 0.4 inch, and a height of between about 0.1 inch and about 0.2 inch. The coupled fastener  20  of this embodiment has a length of between about 0.4 inch and about 0.7 inch, a width of between about 0.2 inch and about 0.4 inch, and a height of between about 0.2 inch and about 0.3 inch plus the thickness of the tissue captured between the male and female pieces. 
     As mentioned previously, a generally conventional instrument such as partially shown in  FIG. 13  may be used to install the fastener  20  of the present invention. The male and female pieces  22 ,  24  of the fastener  20  are positioned on opposite sides of tissue T to be fastened. The instrument holds the needles  38 ,  40  of the male piece  22  in the deployed position as shown in  FIG. 13  so the needles can pierce the tissue T and extend into the holes  74  of the base  72  of the female piece  24  ( FIG. 8 ). As will be appreciated by those skilled in the art, the applicator pushes the needles  38 ,  40  through the tissue and into the holes  74  in the base  72  of the female piece  24 . When the needles  38 ,  40  are inserted in the holes  74  in the base  72 , the slide cover  104  and cover  70  of the female piece  24  cover the sharp points  42 ,  44  of needles so they will not penetrate or injure adjacent tissue in the patient. Further, the notches  92  of the needles  38 ,  40  engage the corresponding openings  80  at the outer ends of the respective clasps  78  to prevent the needles of the male piece  22  from separating from the female piece  24 . 
     In one embodiment, the needles  38 ,  40  are straight as shown. However, in an alternative embodiment the needles are curved. As will be appreciated by those skilled in the art, the needles  38 ,  40  travel along arcs as the applicator pushes the needles through the tissue T and into the holes  74  in the base  72  of the female piece  24 . Because the arcs through which the needles  38 ,  40  travel correspond to their overall shape in this alternative embodiment, the needles follow their respective points  42 ,  44  and do not stretch or tear the tissue as the travel along their arced path. 
     In one embodiment, the needles  38 ,  40  may include a series of notches including notch  92  spaced along each needle to permit the base  30  of the male piece  22  and the base  72  of the female piece  24  to be spaced at several different distances relative to each other when the fastener  20  is fastened to tissue. Moreover, the bases  30 ,  84  may be angled relative to each other so that one needle is inserted farther into the female piece  24  than the other needle. This permits the fastener  20  to accommodate various configurations of tissue. As a result of this adjustability, a desired force can be applied to tissue between the pieces  22 ,  24  whether or not the tissue has a uniform thickness. Accordingly, force can be limited to prevent tissue necrosis. 
     After the male and female pieces  22 ,  24  have been locked together, they may be unlocked and separated from each other. To unlock the fastener  20 , the flanges  82  of the latches  78  are pressed toward each other to the unlatched position. As the flanges  82  are pressed toward the unlatched position, the latches  78  disengage the slots  92  so the pieces  22 ,  24  can be pulled apart. It is envisioned that the fastener  20  can be unlocked, separated and retrieved from the patient using a standard endoscopic snare device (not shown). The snare device is looped around the latch flanges  82 . As the snare loop is pulled, the snared parts are pulled toward each other by decreasing the size of the snare loop. As discussed above, the needles  38 ,  40  are spring-biased to move toward the collapsed positioned shown in  FIG. 3  when not retained against the bias. This operates to prevent injury to the patient when the pieces  22 ,  24  are unlocked and separated, or if the male piece  22  inadvertently becomes separated from the applicator or from the female piece  24 . Given the size of the pieces  22 ,  24  and the protection of sharps from exposure to the patient, the pieces may be safely passed through the gastrointestinal system. 
     It is recognized that various other configurations can be used for locking the female piece  24  relative to the needles  38 ,  40  of the male piece  22 . Examples of alternative configurations are included in U.S. Patent Publication No. 2004/0059354. 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.