Abstract:
An attachment system for tissue apposition or manipulation and a method of attaching a suture to a tissue for apposition or manipulation of the tissue are provided. The system includes an attachment device including a body having a proximal portion and a distal portion. The attachment device further includes a tissue attachment portion operably connected to the distal portion wherein the tissue attachment portion has a shape that is maintained throughout a tissue apposition procedure. The attachment device also includes a suture operably connected to the body and having an unconnected proximal end and a retaining structure at the proximal portion of the body. The retaining structure configured to releasably mate with a complementary retaining structure on a stylet.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/583,409, filed Jan. 5, 2012, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Tissue perforations in the walls of internal organs and vessels may occur naturally may be formed intentionally or unintentionally. Numerous medical devices and methods have been developed to close the perforations and to allow the tissue to heal. In some procedures, it is desirable to retract tissue for further manipulation. For example, a fold may be created in the stomach that results in a gastric reduction by first placing an anchor through the stomach wall and tensioning the anchor so that the stomach wall invaginates. The gastric fold created may than be held in place with another anchor. 
     Devices currently used to close perforations and to hold tissues in position include clips, staples, anchors, sutures, adhesives and the like. The devices may be deployed using minimally invasive techniques, for example using endoscopic or laproscopic systems. For many tissue perforations, accessing the site and approximating the tissue to close the perforation requires complex and time consuming procedures. In some situations, the perforation may be larger than can be treated with a clip to hold the tissue together. For some perforations, the placement of the medical device at the proper site may be difficult. The delivery may be difficult due to engagement of the device within the delivery system, for example the device may be prematurely deployed or the placement may not allow proper apposition of the perforated tissue for healing. Some devices may be long enough to extend through the tissue, but uncontrolled insertion may lead to inadvertent puncturing of tissues due to the device extending too far. Some medical devices may not allow for repositioning of the device at the perforation site when the initial placement is not correct. 
     What is needed in the art is a medical device for repairing tissue perforations and for tensioning or holding tissues that is readily deployable at the tissue site, with controlled insertion and being repositionable to provide for proper tissue apposition. The medical device should also provide for apposition of large tissue perforations. 
     BRIEF SUMMARY 
     Accordingly, it is an object of the present invention to provide a device and a method having features that resolve or improve on the above-described drawbacks. 
     In one aspect, an attachment system for tissue apposition or manipulation is provided. The system includes an attachment device including a body having a proximal portion and a distal portion. The attachment device further includes a tissue attachment portion operably connected to the distal portion wherein the tissue attachment portion has a shape that is maintained throughout a tissue apposition procedure. The attachment device also includes a suture operably connected to the body and having an unconnected proximal end and a retaining structure at the proximal portion of the body. The retaining structure configured to releasably mate with a complementary retaining structure on a stylet. 
     In another aspect, a method of attaching a suture to a tissue for apposition or manipulation of the tissue is provided. The method includes forming a releasable connection between a stylet having a retaining portion and an attachment device having a complementary retaining portion and positioning an inner catheter over the connection to hold the stylet and the attachment device together at the retaining portions. The method further includes positioning a first tissue attachment portion of the attachment device at a first tissue site, rotating the stylet in an insertion direction to insert a distal tip of the tissue attachment portion into a tissue, the tissue attachment portion retaining its shape throughout the insertion and proximally withdrawing the inner catheter proximal to the connection to release the stylet from the attachment device and withdrawing the stylet and the attachment device remains with at least a portion of the attachment device positioned in the tissue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side view of an embodiment of an attachment device in accordance with the present invention; 
         FIGS. 1B and 1C  are partial views of embodiments of tissue attachment portions; 
         FIG. 2  is a side view of an embodiment of an attachment device and a stylet; 
         FIG. 3  is a side view of the attachment device and the stylet shown in  FIG. 2  in a connected position; 
         FIG. 4  is a side view of an embodiment of an attachment device and a stylet; 
         FIG. 5  is a side sectional view of an embodiment of an attachment system; 
         FIG. 6  is a side sectional view of the attachment system shown in  FIG. 5  with the outer sheath withdrawn; 
         FIG. 7  is a side sectional view of the attachment system shown in  FIG. 6  with the inner sheath withdrawn; 
         FIG. 8  illustrates insertion of an embodiment of the attachment device into a tissue; 
         FIG. 9  insertion of an embodiment of the attachment device into a tissue; 
         FIG. 10  illustrates an embodiment of a suture lock system and an embodiment of the attachment device; 
         FIG. 11  illustrates an embodiment of a suture lock system and an embodiment of the attachment device; 
         FIG. 12  illustrates an embodiment of the suture lock system secured to an embodiment of the attachment device; 
         FIG. 13  is a partial side view of an embodiment of an attachment device; and 
         FIGS. 14A and 14B  illustrate embodiments of attachment devices including a suture. 
     
    
    
     DETAILED DESCRIPTION 
     The invention is described with reference to the drawings in which like elements are referred to by like numerals. The relationship and functioning of the various elements of this invention are better understood by the following detailed description. However, the embodiments of this invention are not limited to the embodiments illustrated in the drawings. It should be understood that the drawings are not to scale, and in certain instances details have been omitted which are not necessary for an understanding of the present invention, such as conventional fabrication and assembly. 
     As used in the specification, the terms proximal and distal should be understood as being in the terms of a physician delivering the expandable biopsy device to a patient. Hence the term “distal” means the portion of the attachment device that is farthest from the physician and the term “proximal” means the portion of the attachment device that is nearest to the physician. 
       FIG. 1A  illustrates an embodiment of an attachment device  10  in accordance with the present invention. The attachment device  10  includes a body  12  having a proximal portion  14  and a distal portion  16 . A tissue attachment portion  18  is operably connected to the distal portion  16  of the body  12 . In some embodiments, the tissue attachment portion  18  is a helical member having a sharp distal end  20  for piercing a patient&#39;s tissue. In some embodiments, the tissue attachment portion  18  may be a flattened spiral as shown in  FIG. 1B  or a threaded screw as shown in  FIG. 10  to help hold the attachment device  18  in the tissue. Other configurations for the tissue attachment portion  18  are also possible. The tissue attachment portion  18  may be formed from a biocompatible material such as a metal or plastic and is configured to be rigid and to retain its shape from delivery through implantation into the patient&#39;s tissue. In some embodiments, the tissue attachment portion  18  is configured to be rotated about 4-5 rotations of the device  10  to insert into the tissue and may be removable from the tissue by the same number of rotations. In some embodiments, the tissue attachment portion  18  may be about 0.5 cm to about 2 cm in length, and in some embodiments, about 1 cm in length. In some embodiments, the attachment portion  18  may be formed from a wire having about a 0.01-0.04 inch O.D. and in some embodiments a wire having about a 0.02 inch O.D. 
     The attachment device  10  further includes a suture  22  having a distal portion  24  operably connected to the body  12  and a free end  25 . The proximal portion  14  of the body  12  includes a first retainer  26 . The first retainer  26  is configured to mate with a second retainer  32  provided on a distal portion  34  of a stylet  36  as shown in  FIG. 2 . The first retainer  26  and second retainer  32  have complimentary shapes that mate together to hold the attachment device  10  to the stylet  36  as described in more detail below. In the embodiment shown in  FIG. 2 , the first retainer  26  and the second retainer  32  have a half cylinder shape, each with a flattened portion  33 ,  35  that mate together. The first retainer  26  and the second retainer  32  may have any complimentary shape. See for example another shape shown in  FIG. 4  where the first retainer  26  is a protrusion  42  that mates with the second retainer  32  that includes a recess  44 . The recess  44  includes a pair of expandable arms  46  that enclose the protrusion  42  to hold the attachment device  10  to the stylet  36 . 
     As shown in  FIG. 3 , the attachment device  10  and the stylet  36  are mated together with the complimentary retainers  26 ,  32  joined. As shown in the embodiment of  FIG. 3 , when the complimentary retainers  26 ,  32  are joined, outer diameters of the stylet  36 , a connection region  40  and attachment device  10  are substantially the same. The embodiment shown in  FIG. 4  may also be joined so that when the complimentary retainers  26 ,  32  are joined, the arms  46  of the second retainer  32  fold in around the protrusion  42  of the first retainer so that the outer diameters of the stylet  36 , the connection region  40  and attachment device  10  are substantially the same. 
       FIG. 5  illustrates an embodiment of a delivery system  100  that may be used to deliver the attachment device  10  to the tissue site. The same type of system  100  may also be used to remove the attachment device from the tissue site as discussed in more detail below. As shown, the attachment device  10  is removably joined to the stylet  36  by joining the first and second retainers  26 ,  32  together. An inner sheath  50  is slidably positioned so that a distal end  52  of the inner sheath  50  is positioned over and distal to the joined first and second retainers  26 ,  32 . An inner diameter  54  of the sheath  50  is sized to fit over the first and second retainers  26 ,  32  and hold the first and second retainers  26 ,  32  in the joined position. Without the sheath  50  extending over the first and second retainers  26 ,  32 , the first and second retainers  26 ,  32  are easily separable. 
     An outer sheath  60  is slidably positioned over the inner sheath  50  and is distally extendable so that a distal end  62  of the outer sheath  60  extends distal to the distal end  20  of the attachment device  10  as shown in  FIG. 5 . The outer sheath  60  may be used to deliver the attachment device  10  to a treatment site so that the distal end  20  is not exposed while the device  10  is being guided through a patient&#39;s lumen. Once the device  10  is near the tissue site having the perforation to be joined, the outer sheath  60  may be withdrawn to expose the distal end  20  of the attachment device  10 . 
       FIGS. 6 and 7  illustrate delivery of the attachment device  10  to a tissue  11 . As shown in  FIG. 6 , the outer sheath  60  is proximally withdrawn so that the distal end  20  of the attachment device  10  is exposed. The distal end  20  may include a sharp tip to facilitate entry of the tissue attachment portion  18  into the tissue  11 . With the distal end  20  positioned at the entry site, the stylet  36  may be rotated in an insertion direction  62  using a handle (not shown) so that the attachment device  10  also rotates and the tissue attachment portion  18  is rotatably inserted into the tissue  11 . The inner sheath  50  is positioned over the first and second retainers  26 ,  32  to maintain the connection between the first and second retainers  26 ,  32  while the tissue attachment portion  18  is rotatably inserted so that the body  12  moves with the stylet  36 . If the position of the tissue attachment portion  18  is incorrect, the stylet  36  may be rotated in the opposite direction to the insertion direction  62  to withdraw the tissue attachment portion  18  from the tissue  11 . The tissue attachment portion  18  may then be reinserted in another position. The physician will know the length of the attachment portion  18  so that the depth that the attachment portion  18  is inserted into the tissue is controlled. Once the tissue attachment portion  18  is securely positioned in the tissue  11  in the desired position, the inner sheath  50  may be proximally withdrawn to release the mating connection between the first and second retainers  26 ,  32  as shown in  FIG. 7 . With the inner sheath  50  withdrawn, the attachment device  10  is released from the stylet  36 . The stylet  36 , the inner sheath  50  and the outer sheath  60  may be proximally withdrawn from the patient. The free end  25  of the suture  22  may extend proximally and external to the patient so that the physician may access the free end  25  to facilitate connecting the suture  22  of one attachment device  10  to the sutures  22  of one or more additional attachment devices  10  as described in detail below. In some embodiments, the suture  22  may be pulled proximally to retract the tissue into which the device  10  is inserted. The helical shape of the attachment portion  18  may be used to retract the tissue using greater force than can be used with a straight device. 
       FIG. 8  illustrates a first attachment device  10   a  positioned in the tissue  11   a  so that the tissue attachment portion  18  is implanted into the tissue  11  and at least a portion of the body  12  and the suture  22  extend above the tissue  11 . A perforation  13  is shown between the tissues  11   a  and  11   b . A second attachment device  10   b  is shown in  FIG. 8  being positioned into the tissue  11   b . The stylet  36  is being rotated in the insertion direction  62  so that the distal end  20  of the tissue attachment portion is rotatably inserted into the tissue  11   b.    
       FIG. 9  illustrates to attachment devices  10   a ,  10   b  positioned in tissue  11   a ,  11   b  on opposite sides of the perforation  13 . The delivery system  100  has been withdrawn so that only the attachment devices  10   a ,  10   b  remain in the patient. The sutures  22  have free ends  25  that extend proximally so that the sutures  22  and thus the attachment devices  10   a ,  10   b  can be easily joined to approximate the tissues  11   a ,  11   b  and close the perforation  13 . 
     The sutures  22  may be held together using a suture lock as described briefly herein. Exemplary suture locks may be found in U.S. Publication 2008/0300629 which is herein incorporated by reference in its entirety.  FIG. 10  illustrates an embodiment of a suture lock system  120  that may be employed to join the attachment devices  10   a ,  10   b  together to approximate the tissues  11   a ,  11   b  and close the perforation  13 . The suture lock system  120  includes a suture lock  121  having a sleeve  126  and a locking body  140 . The suture lock system  120  includes an outer catheter  124  that includes the sleeve  126  positioned at a distal end  128  of the outer catheter  124 . The sleeve  126  may include a shoulder  130  that abuts the distal end  128  so the outer catheter  126  can push the sleeve  126  into position as described below. The sleeve  126  may include a cavity  131  that is sized and shaped to accommodate a plurality of attachment devices  10 . The cavity  131  may accommodate 1, 2, 3, 4 or more attachment devices  10 . The outer catheter  124  includes a lumen  132  extending at least partially therethrough. The sleeve  126  is positioned at least partially within the lumen  132  and is releasable from the outer catheter  124 . The sleeve  126  includes a lumen  134  extending therethrough. 
     The suture lock system  120  further includes the locking body  140  that is sized and shaped to at least partially fit with in the lumen  134  of the sleeve  126  and to secure one or more sutures  22  extending through the lumen  134 . The locking body  140  may include a shoulder  142  as shown in  FIG. 10 . The suture lock system  120  may also include an inner catheter  150  that is sized to coaxially extend within the lumen  132  of the outer catheter  124 . The inner catheter  150  includes a distal end  152  that may abut the shoulder  142  of the locking body  140  so the inner catheter  150  may advance the locking body  140  to a locked position as described below. 
       FIG. 11  illustrates the tissue  11   a ,  11   b  having been approximated by pulling the sutures  22  to join the tissue  11   a ,  11   b  together to close the perforation  13 . The outer catheter  124  has been proximally withdrawn and the sleeve  126  released from the outer catheter  124 . The sleeve  126  is shown with the shoulder  130  positioned against the tissue  11   a ,  11   b  and with the attachment devices  10   a ,  10   b  positioned within the cavity  131  of the sleeve  126 . The sutures  22  extend through the lumen  134  of the sleeve  126  and into the lumen  132  of the outer catheter  124 . The inner catheter  150  is advanceable within the outer catheter  124  to move the locking body  140  to a locked configuration  170  shown in  FIG. 12 . In the locked configuration  170 , the plurality of sutures  22  are secured between a wall  127  the sleeve  126  and the locking body  140  so that the sutures  22  may be tensioned to maintain the position of the tissue  11   a ,  11   b . The attachment devices  10   a ,  10   b  are held within the cavity  131  of the sleeve  126  with the tissue attachment portions  18  secured within the tissue  11   a ,  11   b  and the tissue  11   a ,  11   b  approximated. The attachment devices  10   a ,  10   b  remain locked in position so that the perforation can heal. Once the perforation is healed, the attachment devices  10   a ,  10   b , the sleeve  126  and locking body  140  will eventually slough off and pass naturally. 
       FIG. 13  illustrates an embodiment of an attachment device  210  in accordance with the present invention. The attachment device  210  includes a tissue attachment portion  212  having a proximal portion  214  and a distal portion  216 . In some embodiments, the tissue attachment portion  212  is a helical member having a sharp distal end  220  for piercing a patient&#39;s tissue and may be similar to the tissue attachment portion  18  described above. The attachment device  210  may be delivered to the site and rotationally inserted using a torque cable  226  operably connected to the attachment device  210 . The attachment device  210  may be delivered to the site within an outer sheath  228  so that the attachment portion  212  or the distal tip  220  does not contact an accessory channel of a delivery device such as an endoscope or a patient&#39;s tissue until the attachment device  210  is at the proper position. 
     In some embodiments, the attachment device  210  further includes a suture  222  operably connected to the proximal portion  214  of the device  210  as shown in  FIG. 14A . In some embodiments, the attachment device  210  may include a loop  230  at the proximal portion  214 . The suture  222  may be threaded through the loop  230 . Similar to the embodiments described above, the suture  222  may be used to join the device  210  to other attachment devices  210  or to retract the tissue to which the device  210  is inserted. A plurality of devices  210  may be positioned in adjacent tissue sites similar to the devices  10  described above to approximate tissue portions and may be secured using a suture lock as described above. The closure may be a purse string closure with multiple devices  210  being pulled together using the sutures  222 . 
     The attachment devices described herein may also be removed from the tissue site using a device like the delivery system described above. By way of non-limiting example, the removal of the attachment device  10  will be described with respect to the delivery system  100  and  FIGS. 5-7 . If multiple attachment devices  10  are joined together by the suture  22  or other attachment, the suture  22  may be cut using a cutting device before removal of each attachment device  10 . To remove the attachment device  10 , the insertion method shown in  FIGS. 5-7  may be reversed. The stylet  36  is extended from the inner sheath  50  and the outer sheath  60  and the first and second retainers  26 ,  32  are aligned as shown in  FIG. 7 . The stylet  36  is advanced toward the attachment device  10  so the attachment device  10  is joined to the stylet  36  and the first and second retainers  26 ,  32  are joined. The inner sheath  50  is advanced toward the tissue until the first and second retainers  26 ,  32  that are rejoined are covered by a portion of the inner sheath  50  as shown in  FIG. 6 . The stylet  36  may be rotated in a direction opposite the insertion direction  62  using a handle (not shown) so that the attachment device  10  also rotates and the tissue attachment portion  18  is rotatably removed from the tissue  11 . The inner sheath  50  is positioned over the first and second retainers  26 ,  32  to maintain the connection between the first and second retainers  26 ,  32  while the tissue attachment portion  18  is rotatably removed so that the body  12  moves with the stylet  36 . Once the tissue attachment portion  18  of the attachment device  10  is completely removed from the tissue, the outer sheath  60  may be advanced over the inner sheath  50  and the tissue attachment portion  18  to cover the distal end  20  of the attachment device  10  as shown in  FIG. 5 . The outer sheath  60  may be used to remove the attachment device  10  from the patient so that the distal end  20  is not exposed while the device  10  is being guided through a patient&#39;s lumen. 
     The materials used to form the attachment devices described herein and the suture lock may be any biocompatible materials suitable for implantation in a bodily lumen. By way of non-limiting example, the tissue attachment portion may be made from any suitable biocompatible metal, such as stainless steel and shape memory alloys, such as nitinol or plastic that are sufficiently rigid to maintain the shape the tissue attachment portion throughout the procedure. The tissue attachment portion is not intended to change shape once the portion is inserted into the tissue. The body, the sleeve and the locking body may be formed from any suitable material such as stainless steel, titanium, nitinol or other metals/alloys as well as various ceramics and plastic materials, such as polycarbonates, polyamides including nylon, polytertrafluorethylenes (i.e. PTFE and EPTFE), polyethylene ether ketones (PEEK), poly vinyl chlorides, polyimides, polyurethanes, and polyethylenes, including multi-layer or single layer constructions with or without reinforcement wires, coils or filaments. The sutures may be made from common suture material as known in the art, for example polyester suture such as 4-0 Tevdek®, nylon, silk, polypropylene, ultra high molecular weight polyethylene (UHMPE) and the like. The sutures may be monofilament, braided, twisted or multifilament. 
     The above Figures and disclosure are intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in the art. All such variations and alternatives are intended to be encompassed within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the attached claims.