Abstract:
A ligation device is disclosed that is capable of containing a fluid, e.g., a biomechanical medium or an antimicrobial solution. The ligation device comprises an upper clip and a lower clip, each having a locking feature that enables the upper clip and the lower clip to be movably attached to each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation of U.S. application Ser. No. 12/542,883 filed Aug. 18, 2009 and the disclosure of the above-identified application is hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to apparatus and methods for joining tissue portions and occluding vessels. 
         [0004]    2. Background of Related Art 
         [0005]    Ligation devices are used to join tissue portions and to occlude vessels. When tissue is held together by ligation devices that penetrate the body, the risk of foreign matter entering the site of a surgical wound is increased. To reduce the risk of infection, ligation devices can be coated with an antimicrobial or antibiotic material. 
         [0006]    Once inserted into the body, ligation devices will remain in place unless they are either physically removed or dissolved in the body. The physical removal of non-resorbable ligation devices is a complicated surgical procedure typically involving the use of specially designed instruments. 
       SUMMARY 
       [0007]    The present disclosure describes various methods and devices for tissue ligation and/or vessel occlusion. A device for delivering a localized antimicrobial solution or a biomechanical medium is described. 
         [0008]    A ligation device may include a fastener member having a backspan and at least two prongs generally perpendicular to the backspan, a retainer portion having a connector and at least two columnar members attached to the connector, each columnar member having an aperture to receive and to retain the prongs, and a reservoir located within at least one of the columnar members. In another embodiment, the ligation device may include a fastener member having a backspan and legs generally perpendicular to the backspan with at least one leg housing a reservoir, and a retainer portion with a connector and at least two columnar members attached to the connector, each columnar member having an aperture to receive and retain the legs. The ligation device may also include a locking surface extending from at least one prong that is removably attached to a locking surface extending from at least one aperture. 
         [0009]    Within the reservoir, a fluid such as an antimicrobial medium or solution may be stored. To facilitate storage of the fluid, a membrane seal may be positioned at the opening of the reservoir. Dispersion of the fluid may be facilitated by puncturing the membrane seal upon insertion of the fastener member into the retainer portion. The prongs of the fastener member may include a sharp distal tip to facilitate the opening of the membrane seal. A groove may be located on an inner surface of the retainer portion to facilitate dispersion of the fluid. 
         [0010]    The various aspects of the present disclosure will be more readily understood from the following description when read in conjunction with the appended figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    By way of description only, embodiments of the disclosure will be described with reference to the accompanying drawings, in which: 
           [0012]      FIG. 1  is a side cross-sectional view showing a ligation device according to one embodiment of the present disclosure; 
           [0013]      FIG. 2  is a side cross-sectional view of the ligation device of  FIG. 1  showing a distal portion of an upper clip inserted into a cavity of a lower leg; 
           [0014]      FIG. 3  is a side cross-sectional view of the ligation device of  FIG. 2  showing the upper leg engaged in the cavity of the lower leg; 
           [0015]      FIG. 4  is a front view of a ligation device according to an embodiment of the present disclosure; and 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Particular embodiments of the present disclosure will be described herein with reference to the accompanying drawings. As shown in the drawings and as described throughout the following descriptions, and is traditional when referring to relative positioning on an object, the term “proximal” refers to the end of the apparatus that is closer to the user and the term “distal” refers to the end of the apparatus that is further from the user. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. 
         [0017]    As seen in  FIG. 1 , a ligation device  100  is shown including a fastener member  10  and a retainer portion  11 . The fastener member  10  includes a backspan  7  and at least two prongs or legs  18  that are generally perpendicular to the backspan  7 . The retainer portion  11  includes a connector  6  and at least two columnar members  5  configured and adapted to receive the prongs  18  of the fastener member  10  therein. The connector  6  is a generally U-shape member. The connector  6  may be resilient or flexible. As such, the connector  6  allows the columnar members  5  to move towards each other and away from each other. Similarly, the backspan  7  may be resilient or flexible, thereby allowing the fastener member  10  to match the spacing between the columnar members  5  of the retainer portion  11 . At least one of the columnar members  5  is configured and adapted to store a fluid  15  within a reservoir  14  within the columnar member  6 . A membrane seal  16  may be positioned on or within the retainer portion  11  to facilitate storage of the fluid  15  within the reservoir  14 . The fluid  15  is released from the reservoir  14  upon insertion of the fastener member  10  into the retainer portion  11 . To facilitate release of the fluid  15  upon insertion of the fastener member  10  into the retainer portion  11 , prongs  18  may include a sharp distal tip  9  that is configured and adapted to puncture the membrane seal  16 . Dispersion of the fluid  15  may be facilitated by a groove  8 , as shown in  FIG. 1 , positioned on the inner profile of the retainer portion  11 . In an alternative embodiment, the groove  8  may be positioned on the inner profile of the fastener member  10 . 
         [0018]    As seen in  FIGS. 1-3 , prong  18  is shown having a recess  12  that is engagable with a protrusion  13  within the columnar member  8 . Variations of this structure that are in the spirit of this disclosure will be apparent to those skilled in the art. For example, the prong  18  may have a protrusion that is engagable with a recess within the columnar member  8 .  FIG. 3  shows the recess  12  engaged with the protrusion  13 , thereby locking the fastener member  10  to the retainer portion  11 . As shown in  FIG. 3 , the recess  12  can be disengaged form the protrusion  13  by sliding the retainer portion  11  apart from the fastener member  10  in the direction of arrow A. To facilitate movement of the fastener member  10  and the retainer portion  11  apart from each other, the fastener member  10  and the retainer portion  11  may be formed from a material capable or small defections, e.g., an elastic and/or resilient material. 
         [0019]    In an alternative embodiment, as seen in  FIG. 4  ligation device  200  includes an upper clip  20  and a lower clip  23 . The upper clip  20  includes a leg  20   a  including a reservoir  24  that is sealed by a membrane  21 . The lower clip  23  includes a cutting element  22  extending from columnar member  23   a  that is capable of puncturing the membrane  21 . Fluid  15  can be stored within the reservoir  24 . 
         [0020]    Fluid  15  may be for example, but is not limited to being, an antiseptic or an antimicrobial solution, a biomechanical medium, and/or a wound treatment material. Examples of antimicrobial agents include but are not limited to β-Lactam agents, such as penicillins, and cephalosporins. By way of example only, the fluid  15  may include an antimicrobial hydrogel and may be in the form of a thixotropic, non-cytotoxic hydrogel. Preferably, the fluid  15  will facilitate healing by decreasing the likelihood of infection while not inhibiting healing of the surgical site. 
         [0021]    The ligation devices disclosed herein may be made from natural or synthetic bio-absorbable materials, including but not limited to, alloys and polymers. Examples of families of bioabsorbable polymers include polymers having glycolic and ester linkages, including but not limited to polyesters, poly(amino acids), polyanhydrides, polyortho-esters, polyurethanes, polycarbonates, poly(dioxanone) (PDO), polyethylene glycol (hydrogels, polylactides (PLA), polyglycolides (PGA), polycaprolactone (PCL), and their copolymers. Some of the polymers, such as hydrogels, are hydrophilic. Others, such as PCL, are hydrophobic. The bioabsorbable polymers may be prepared by copolymerization of various monomers to modify and improve their properties as applications demand, e.g., poly(lactide-co-glycolide) copolymers. Because these polymers degrade by hydrolysis, the type of polymer and its physical form used in a particular application has an effect in defining the degradation period. Mechanical blending, as opposed to copolymerization, can also further enhance their properties. 
         [0022]    Biocompatible, solid-solution strengthened alloys such as iron-based alloys, cobalt-based alloys and titanium-based alloys as well as refractory metals and refractory-based alloys may be utilized in the manufacture of such implantable medical devices. For example, traditional stainless steel alloys such as 316L, i.e., UNS S31603, may be utilized as an implantable, biocompatible device material. Depending upon the material selected, degradation of the material may be accelerated after exposing the material to radiation, including but not limited to gamma radiation. 
         [0023]    Additionally, the ligation device  100  may also be made from materials impregnated or coated with substances known to have antimicrobial properties, such as silver or an antimicrobial medium. For example, oligodynamic metals including silver, copper, iron, zinc, bismuth, gold, aluminum, and other metals are known to have antimicrobial properties. 
         [0024]    It will be understood by those skilled in the art that various modifications and changes in form and detail may be made therein without departing from the scope and spirit of the present disclosure. Accordingly, modifications such as those suggested above, but not limited thereto, are to be considered within the scope of the disclosure.