Abstract:
A surgical fastener for fastening tissue. The fastener includes a first piece having a curved needle, a second piece having an opening sized for receiving the needle, and a lock for holding the needle of the first piece in the opening of the second piece.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to a surgical fastener, and more particularly to a surgical fastener having curved piercing elements. 
         [0002]    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. 
         [0003]    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 discloses one such fastener and an applicator used with this fastener. 
         [0004]    The applicator disclosed in U.S. Pat. No. 7,033,378 includes an elongate shaft having two jaws pivotally attached to its end. The jaws include receptacles for holding the first and second pieces of the fastener. The jaws push the needles of the first piece through the gathered tissue and the openings of the second piece to hold the tissue and fastener in place. As will be appreciated by those skilled in the art, because the jaws are pivotally attached to the shaft, each of the needles sweeps through an arc as the jaws pivot to pierce the tissue and push the needles into the corresponding openings. As a result of the needles sweeping through arcs, the needles do not enter and pass through the tissue at a single point. Rather, the needles trace a line, increasing the force required to push the needles through the tissue and potentially causing the tissue to tear. 
         [0005]    Moreover, on occasion fasteners will become unfastened during post-operative recovery so the fasteners are free to move about the patient&#39;s body. In the case of fasteners used in gastroesophageal applications, the unfastened fasteners can move through the patient&#39;s esophagus, stomach and/or bowel. As the fasteners move, the piercing elements of can pierce portions of the patient&#39;s body with which they come in contact unless provisions are made to protect the body from the elements. 
       SUMMARY OF THE INVENTION 
       [0006]    Briefly, the present invention includes a surgical fastener for fastening tissue. The fastener comprises a first piece having a curved needle, a second piece having an opening sized for receiving the needle therein, and a lock for holding the needle of the first piece in the opening of the second piece. 
         [0007]    In another aspect, the invention includes a surgical fastener for fastening tissue. The fastener comprises a first piece having a curved needle, and a second piece having an opening sized for receiving the needle and adapted for holding the needle of the first piece in the opening of the second piece. 
         [0008]    In yet another aspect, the invention includes a surgical fastener for fastening tissue. The fastener comprises a first piece having a base and a plurality of curved needles attached thereto. Each of the needles is adapted for movement between a collapsed position in which the needle extends generally parallel to the base and a deployed position in which the needle extends outward from the base. The fastener also comprises a second piece having a plurality of openings therein. Each of the openings is sized and positioned for receiving one of the needles therein when the needles are in the deployed position. Further, the fastener comprises a lock for holding each of the needles of the first piece in the respective opening of the second piece. 
         [0009]    In another aspect, the invention includes a surgical fastener for use with an applicator to fasten tissue. The fastener comprises a first piece including a needle having a shape defined be a path through which the applicator moves the needle when fastening tissue. In addition, the fastener comprises a second piece having an opening sized for receiving the needle therein, and a lock for holding the needle of the first piece in the opening of the second piece. 
         [0010]    Other features of the present invention will be in part apparent and in part pointed out hereinafter. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective of a surgical fastener of the present invention; 
           [0012]      FIG. 2  is a perspective of a male piece of the fastener of  FIG. 1  shown with needles in a deployed position; 
           [0013]      FIG. 3  is a perspective of the male piece shown with the needles in a collapsed position; 
           [0014]      FIG. 4  is an alternate perspective of the surgical fastener; 
           [0015]      FIG. 5  is a perspective similar to  FIG. 1  with a latch body cover and base removed to facilitate viewing interior structure; 
           [0016]      FIG. 6  is a perspective of a surgical fastener of the present invention shown with a portion of an applicator used to install the fastener in a patient; 
           [0017]      FIG. 7  is a perspective similar to  FIG. 1  with a slide assembly in a locked position; and 
           [0018]      FIG. 8  is a perspective similar to  FIG. 5  with the slide assembly in the locked position. 
       
    
    
       [0019]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0020]    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 . 
         [0021]    As shown in  FIG. 2 , the male piece  22  includes a base  30  having two openings  32 ,  34 . An elongate channel  36 ,  38  extends from each opening  32 ,  34 . A recess  40 ,  42  is positioned adjacent each opening  32 ,  34 , generally opposite one of the channels  36 ,  38 . Two elongate curved needles or posts  50 ,  52  are rotatably coupled to the base  30 . Each of the needles  50 ,  52  is held in position in its corresponding opening  32 ,  34  by an axle pin  54 ,  56  so the needle is aligned with its corresponding channel  36 ,  38 . Although the needles  50 ,  52  are adapted to pierce tissue, in one embodiment they have slightly rounded tips  58 ,  60  so they displace tissue rather than cut tissue. Torsion springs  62 ,  64  are fitted over each axle pin  54 ,  56  so one end is coupled to the corresponding needle  50 ,  52  and another end is biased against the base  30  in the corresponding recess  40 ,  42 . The torsion springs  62 ,  64  operate to bias the corresponding needle  50 ,  52  toward a collapsed position in which the needles lie in the corresponding channel  36 ,  38  as shown in  FIG. 3 . Thus, when the male piece  22  and the female piece  24  are unfastened, the needles  50 ,  52  collapse so the tips  58 ,  60  are covered and cannot pierce tissue within the patient as the fastener  20  moves through the body. When the needles  50 ,  52  extend generally perpendicular to the base as shown in  FIG. 2 , the needles are in a deployed position. Although the needles  50 ,  52  may have other lengths departing from the scope of the present invention, in one embodiment each needle has a length measured from a center of the axle pin to its respective tip of between about ten millimeters and about twenty millimeters. In one particular embodiment, each needle  50 ,  52  has a length of at least about twenty millimeters so it can penetrate two full thicknesses of stomach tissue (each full thickness including a mucosal layer, a muscularus layer and a serosal layer). Although the needles  50 ,  52  may have other shapes and dimensions without departing from the scope of the present invention, in one embodiment each needle has a circular cross section and a diameter of between about one millimeter and about two millimeters. In one particular embodiment, each needle  50 ,  52  tapers from a diameter of less than about one millimeter at the tip to less than 1.5 millimeters at the base so the needles penetrate tissue easily, so the needles have sufficient strength to maintain alignment during tissue penetration and so the holes made by the needles in the tissue are not prone to leakage. Further, although the needles  50 ,  52  may have other shapes without departing from the scope of the present invention in one embodiment the needles are curved. In one particular embodiment, the needles  50 ,  52  are arcuate and have a radius of curvature of between about twelve millimeters and about thirty millimeters. In one embodiment, the radius of curvature of each needle  50 ,  52  is equal for manufacturing convenience. In another embodiment shown in  FIG. 6 , the needles  50 ,  52  have a common center of curvature C and radii of curvature corresponding to a distance between the center of curvature and the particular needle. As will be appreciated by those skilled in the art, the common center of curvature in this embodiment is positioned at the pivot axis P of jaws of an applicator A which are used to install the fastener in the patient. One such applicator A is described in U.S. Pat. No. 7,033,378 and will not be described in further detail. In one embodiment, the needles  50 ,  52  lie in a common plane. 
         [0022]    As further shown in  FIG. 3 , the channels  36 ,  38  may be oriented at an angle within the base  30  to accommodate longer needles  50 ,  52  without increasing a length of the base. Each needle  50 ,  52  includes a series of notches or grooves  66  near its tip  58 .  60 . A lower portion  68 ,  70  of each needle  50 ,  52  opposite the tip  58 ,  60  extends beyond the axle pin  54 ,  56  ( FIG. 2 ) so that the lower portion extends beyond the base  30  when the needles are in the deployed position as shown in  FIG. 2 . The lower portions  68 ,  70  may be held by an applicator (not shown) to maintain the needles  50 ,  52  in the deployed position against the forces applied by the torsion springs  62 ,  64 . The lower portions  68 ,  70  may also include openings  72 ,  74  for receiving portions of the applicator. Features of an exemplary applicator are described in detail in U.S. Pat. No. 7,033,378. 
         [0023]    As shown in  FIG. 1 , the female piece  24  includes a latch body, generally designated by  80 , and a slide assembly, generally designated by  82 , slidably connected to the latch body. The latch body  80  includes a base  84  and a cover  86 . The base  84  includes two openings or holes  88 ,  90 . These holes  88 ,  90  are sized and positioned to receive the needles  50 ,  52  of the male piece  22 . Preferably, the holes  88 ,  90  are chamfered to guide the needles  50 ,  52  into them to permit modest misalignment of the needles and holes. As illustrated in  FIG. 4 , in one embodiment the cover  86  of the latch body is U-shaped, having an end portion  92  and two side portions  94  extending from the end portion. Thus, the end portion  92  and side portions  94  define a central opening  98  in the cover  86 . The end portion  92  has an opening  96  adjacent the base  84  of the latch body  80  for accommodating a portion of the slide assembly  82  as will be explained in greater detail below. 
         [0024]    As illustrated in  FIG. 5 , the slide assembly  82  includes a body  100 , a lock  102 , and a cover  104 . The body  100  has two elongate slots  106 ,  108  sized and positioned for receiving the needles  50 ,  52  when extending through the holes  88 ,  90  in the base  84  of the latch body  80 . As will be appreciated by those skilled in the art, the slots  106 ,  108  permit the slide assembly  82  to move relative to the latch body  80  between an unlocked position shown in  FIG. 1  and a locked position shown in  FIG. 7 . As further shown in  FIG. 5 , the body  100  also has a recess  110  for receiving the lock  102 . The lock  102  includes a central portion  112  sized and shaped for engaging the recess of the body  100  to hold the lock in position relative to the body. As will be appreciated by those skilled in the art, the lock  102  is captured between the slide assembly body  100  and the base  84  of the latch body  80  so the lock is retained in the recess  110 . Two arms or catches  114 ,  116  extend outward in opposite directions from the central portion  112  of the lock  102 . The arms  114 ,  116  are flexible but biased toward a position in which they overlap the slots  106 ,  108  in the body  100 . As will be described below, each arm  114 ,  116  selectively engages corresponding slots  66  in the needles  50 ,  52 . Each of the arms  114 ,  116  includes an angled portion  118 ,  120  for guiding the respective arm into the corresponding slot. The arms  114 ,  116  also include stops  122 ,  124  for preventing the arms from blocking the slots  106 ,  108  when the needles  50 ,  52  are not present. During manufacture, the slide assembly cover  104  is attached to the latch slide  100  with pins  130  that are press fit into coupling holes  132 , and the lock  102  is inserted into the recess  110 . The slide assembly  82  is then captured between the latch body  80  and base  84 . 
         [0025]    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 length of about 15 mm, a width of about 6.25 mm, and a height of about 2 mm when the needles are in their collapsed positions. In this embodiment, the female piece  24  has a length of about 15 mm, a width of about 6.25 mm, and a height of about 4 mm. The coupled fastener  20  of this embodiment has a length of about 15 mm, a width of about 6.25 mm, and a height of about 6 mm plus the thickness of the tissue captured between the male and female pieces. 
         [0026]    Although the pieces  22 ,  24  may be made of other materials without departing from the scope of the present invention, in one embodiment the pieces are made of titanium or titanium alloy, and anodized. In one particular embodiment, the pieces  22 ,  24  are anodized to have a color that is distinct from natural colors of tissue of the stomach cavity so that the pieces may be easily seen during visual inspection during surgery. Preferred colors include purple, blue and black. 
         [0027]    A conventional instrument (not shown) such as described in U.S. Pat. No. 7,033,378 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 to be fastened. The instrument holds the needles  50 ,  52  of the male piece  22  in the deployed position as shown in  FIG. 2  so the needles can pierce the tissue and extend into the holes  88 ,  90  of the base  84  of the female piece  24  ( FIG. 1 ). The chamfered openings of the holes  58 ,  60  guide the needles  50 ,  52  into the holes if the pieces  22 ,  24  are slightly misaligned. As will be appreciated by those skilled in the art, the needles  50 ,  52  travel along arcs as the applicator pushes the needles through the tissue and into the holes  88 ,  90  in the base  84  of the female piece  24 . Because the arcs through which the needles  50 ,  52  travel correspond to their overall shape, the needles follow their respective points  58 ,  50  and do not stretch or tear the tissue as they travel along their arced path. When the needles  50 ,  52  are inserted in the holes  88 ,  90  in the base, the slide cover  104  and latch cover  86  cover the sharp points  58 ,  60  of needles so they will not penetrate or injure adjacent tissue in the patient. 
         [0028]    Referring now to  FIGS. 7 and 8 , once the fastener  20  is positioned around the tissue with a desired clamping force (or desired pressure), the slide assembly  82  is moved longitudinally relative to the latch body  80  until the body  100  abuts the cover  86  of the latch body  80 . As the slide assembly  82  moves relative to the body  80 , the arms  114 ,  116  engage the respective slots  66  of the needles  50 ,  52 , thereby locking the male and female pieces  22 ,  24  together and clamping the captured tissue between them. The plurality of slots  66  permit the base  30  of the male piece  22  and the base  84  of the latch body  80  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 latch body 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. When the slide assembly  82  is moved relative to the latch body  80 , the arms  114 ,  116  will automatically find an appropriate slot  66 . Further, the flexibility of the arms  114 ,  116  compensates for small amounts of misalignment between the arms and slots  66 . If an arm  114 ,  116  of the lock  102  initially contacts a needle  50 ,  52  at a non-slotted location, the flexibility of the arm will permit it to move into an adjacent slot  66 . When locked, a gap  134  is formed between the latch body  80  and the cover  86  of the slide assembly  82  as shown in  FIG. 7 . 
         [0029]    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 slide assembly  82  is moved relative to the latch body  80  so the gap  134  closes. As the gap  134  closes, the arms  114 ,  116  disengage the slots  66  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 slide body  104  and cover  86 . 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  50 ,  52  are spring-biased to collapse into the channels  36 ,  38  of the base  30  of the male piece  22  when not retained against the bias of the torsion springs  62 ,  64 . 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. 
         [0030]    It is recognized that various other configurations can be used for locking the female piece  24  relative to the needles  50 ,  52  of the male piece  22 . Examples of alternative configurations are included in U.S. Pat. No. 7,033,378. 
         [0031]    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. 
         [0032]    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.