Abstract:
Device, system and method for drawing together patient tissue. A bridge segment has an axis and a first end and a second end opposite the first end. A first tine is coupled to the first end and projects from the bridge segment in a first direction orthogonal to the bridge segment. A second tine is coupled to the first end and projects from the bridge segment in a second direction approximately opposite the first direction. A third tine is coupled to the second end and projects from the bridge segment approximately in the first direction. A fourth tine is coupled to the second end and projects from the bridge segment approximately in the second direction. The first, second, third and fourth tines are each resiliently biased to form a coil approximately parallel to a plane orthogonal to the axis of the bridge segment.

Description:
FIELD 
       [0001]    The present invention relates generally to devices, systems and methods of drawing patient tissue together, and in particular such devices, systems and methods of drawing patient tissue together using a medical clip. 
       BACKGROUND 
       [0002]    In many circumstances and for many reasons, it is often beneficial to capture and draw together two or more pieces of tissue of a patient. The location of the tissue and the circumstances of the need to draw the pieces of tissue together have long resulted in a variety of different devices and methods for drawing the tissue together. Devices such as bandages, both self-adhesive and otherwise, clamps and stitches have been used to capture pieces of tissue and draw them together. Once tissue is drawn together, the natural healing abilities of the body may then allow the pieces of tissue to grow together, over time sealing a gap between the pieces of tissue such that the device is no longer needed. Alternatively, the pieces of tissue may be held together by the device indefinitely or for a particular period of time. 
         [0003]    But, dependent on the location of the tissue, certain devices and methods may be impractical to utilize. For instance, while stitches may lend themselves well to readily accessible patient tissue, such as skin and muscle tissue, relatively inaccessible tissue, such as that found in the organs of the patient, may be impractical to capture and draw together using stitches. As such, the use of stitches to treat a defect in a patient&#39;s heart may tend require a traumatic open heart procedure, and even then, because the interior of the heart still may not be readily accessible, the treatment of a defect inside the heart may still not be attainable with stitches. Thus, a common device and method for drawing together patient tissue may not be applicable for all situations, particularly those involving a defect in organs of the patient such as the heart. 
         [0004]    One relatively common defect in the heart of newborn children, which may also be present in older children and in adults, is a patent foramen ovale (“PFO”). During the gestation of a fetus in the womb, blood is oxygenated not by the undeveloped lungs of the fetus, but rather by the placenta of the mother. However, the heart of the fetus nevertheless pumps the blood through the cardiovascular system and receives the blood from the cardiovascular system. As such, in order to avoid the undeveloped lungs of the fetus, various vessels and bypasses exist that operate only during gestation that divert the blood from the lungs. At birth these bypasses typically close and circulation occurs by way of the lungs as with a normally developed adult. 
         [0005]    An opening between the right atrium and the left atrium called the foramen ovale is open during gestation to prevent transfer of blood from the right ventricle of the heart to the lungs during gestation. Upon birth, the child&#39;s inherent circulation creates pressure within the atrium which causes a flap of tissue to close over the foramen ovale. As the child matures, the flap of tissue develops into a permanent closure. However, in some children the flap of tissue does not close, either in whole or in part, over the entire foramen ovale, creating a patent foramen ovale. The continued existence of the foramen ovale results in continued diversion from the lungs of at least some of the child&#39;s blood, reducing the flow of oxygenated blood through the child&#39;s system, and potentially leading to serious complications to the health of the child. 
         [0006]    It is recognized that although PFO may occur most prominently in children and, in particular, relatively newborn children, that the PFO may also occur or be present in older children and in adults. 
         [0007]    Other cardiac defects are known to exist beyond patent foramen ovales. For instance, atrial-septal defects (“ASD”) and ventricular-septal defects (“VSD”) likewise sometimes occur and may be detrimental to the health of the person, e.g., a child. Historically, open heart surgery had been required to fix such defects. But open heart surgery carries with it serious and well-known and recognized risks to the well-being of the person, in addition to being expensive and a considerable burden on hospital resources. 
         [0008]    Closure devices for treating heart defects, such as patent foramen ovales, have been developed. 
         [0009]    U.S. Pat. No. 6,776,784, Ginn, Clip Apparatus For Closing Septal Defects and Methods of Use, (Core Medical, Inc.) discloses a device for closing a septal defect, such as a patent foramen ovale, includes a clip formed from a superelastic material that is inserted into a septum wall of a heart. The clip is advanced through a patient&#39;s vasculature, e.g., within a delivery apparatus, until the clip is disposed within a first chamber adjacent the septal defect. Tines of the clip are directed through a flap of tissue of the septal defect until the tines of the clip are disposed within a second opposing chamber. The clip then transforms into its relaxed state, wherein the tines of the clip engage with a surface of the second chamber, thereby substantially closing the septal opening. 
         [0010]    U.S. Patent Application Publication No. US2007/0060858, Sogard et al, Defect Occlusion Apparatus, System and Method, discloses occluding a multiplicity of parallel membranes, such as found in a patent foramen ovale. The methods, apparatus, and systems include the use of a positioning device that can be seated on the limbus of the septum secundum. The positioning device includes a piercing member that can pierce the septum secundum and septum primum. The positioning device also includes a fastening member that can engage the septum secundum and septum primum to fasten the tissues and thereby occlude a patent foramen ovale. 
         [0011]    U.S. Pat. No. 7,220,265, Chanduszko et al, Patent Foramen Ovale (PFO) Closure Method and Device, (NMT Medical, Inc.) discloses methods and devices for closing two overlapping layers of tissue in a mammalian heart, such as a patent foramen ovale. The closure devices may take a number of different forms and may be retrievable. In some embodiments, the closure devices may be delivered with a catheter capable of puncturing mammalian tissue. In some embodiments, a spring-like bioabsorbable polymer material are used, in one such embodiment as a “grappling hook”, to embed in and draw together the pieces of tissue. In another embodiment, a suture is delivered, and an anchor forms a pre-determined shape and engages the septum secundum, closing the patent foramen ovale. 
       SUMMARY 
       [0012]    Closure devices for treating patent foramen ovales have been developed that allow for the treatment of patent foramen ovales and other cardiac defects without conducting open heart surgery. Instead, the closure devices may be utilized to cure or treat cardiac defects by way of transvenous implantation. With the device placed in a sheath attached to a catheter small enough to pass through the blood vessels of the child and into the heart, the device may be deployed in the heart to treat the cardiac defect. 
         [0013]    The device itself may be made of a number of joined tines, each of which may form a loop, perhaps sharpened at the end to allow for puncturing the cardiac tissue of the patient. Outside of the implantation sheath each tine may be biased so that each tine forms a loop or coil in a relaxed state. Inside of the sheath the tines are uncoiled to be relative linear, possibly giving the device an adequately small profile to allow passage of the device through a vein or other vascular component of the patient. When the device is deployed from the sheath the tines may curl into a biased (relaxed) coiled form. During a transition from a relatively linear configuration to a coiled configuration, as the device is deployed from the sheath, within the heart the sharpened end of the tines may pass through cardiac tissue. In the case of the treatment of a patent foramen ovale, if the device is positioned adjoining the two flaps of tissue which did not automatically close together, at least one approximately linear tine may pass through each flap of tissue as coils are formed. As the tines complete forming a coil, the two flaps of tissue may be drawn together, either closing the foramen ovale altogether, or bringing the flaps of tissue in closer proximity of each other such that vascular pressure may ultimately bring the flaps of tissue together. As the patient matures flaps of tissue may grow together and the foramen ovale close permanently. 
         [0014]    In an embodiment, a medical clip is disclosed for drawing together patient tissue. The medical clip comprises a bridge segment having an axis and a first end and a second end opposite the first end, a first tine coupled to the first end of the bridge segment and projecting from the bridge segment in a first direction approximately orthogonal to the bridge segment, a second tine coupled to the first end of the bridge segment and projecting from the bridge segment in a second direction approximately opposite the first direction, a third tine operatively coupled to the second end of the bridge segment and projecting from the bridge segment approximately in the first direction, and a fourth tine coupled to the second end of the bridge segment and projection from the bridge segment approximately in the second direction. The first tine, the second tine, the third tine and the fourth tine are each resiliently biased to form a coil approximately parallel to a plane orthogonal to the axis of the bridge segment. 
         [0015]    In an embodiment, each of the tines may be flexed to be approximately linear. 
         [0016]    In an embodiment, the coil comprises at least one full revolution. 
         [0017]    In an embodiment, the coil comprises at least one-and-a-quarter revolutions. 
         [0018]    In an embodiment, the tines are configured to pass through the patient tissue. 
         [0019]    In an embodiment, the tines are configured to draw a first piece of the patient tissue together with a second piece of the patient tissue. 
         [0020]    In an embodiment, at least one of the first tine and the third tine are configured to pass through the first piece of patient tissue and wherein at least one of the second tine and the fourth tine are configured to pass through the second piece of patient tissue. 
         [0021]    In an embodiment, the first tine and the third tine pass through the first piece of patient tissue and the second tine and the fourth tine pass through the second piece of patient tissue during a transition from being approximately linear to forming the coil. 
         [0022]    In an embodiment, the first piece of tissue is drawn together with the second piece of tissue when the tines form the coil. 
         [0023]    In an embodiment, the first tine, the second tine, the third tine and the fourth tine are each comprised of nitinol. 
         [0024]    In an embodiment, a system is disclosed for drawing together patient tissue. The system comprises a medical clip and a delivery catheter. The medical clip comprises a bridge segment having an axis and a first end and a second end opposite the first end, a first tine coupled to the first end and projecting from the bridge segment in a first direction approximately orthogonal to the bridge segment, a second tine coupled to the first end and projecting from the bridge segment in a second direction approximately opposite the first direction, a third tine operatively coupled to the second end and projecting from the bridge segment approximately in the first direction, and a fourth tine coupled to the second end and projection from the bridge segment approximately in the second direction. Each of the tines is resiliently biased to form a coil approximately parallel to a plane orthogonal to the axis of the bridge segment. The delivery catheter comprises a lumen containing the medical clip with the first tine, the second tine, the third tine and the fourth tine being flexed to be approximately linear by the delivery catheter and a deployment mechanism positioned within the lumen adapted to deploy the medical clip by pushing the medical clip out of an opening in the lumen. The first tine, the second tine, the third tine and the fourth tine coil when the medical clip is deployed from the delivery catheter. 
         [0025]    In an embodiment, a method is disclosed for drawing together tissue of a patient using a medical clip having a first tine and a third tine coupled to a first end of a bridge segment and a second tine and a fourth tine coupled to a second end of the bridge segment, wherein the first tine, the second tine, the third tine and the fourth tine are each resiliently biased to form a coil. The method comprises the steps of placing a delivery catheter having a lumen containing the medical clip between a first piece of the tissue and a second piece of the tissue, wherein the first tine, the second tine, the third tine and the fourth tine are straightened while in the delivery catheter and deploying the medical clip from the delivery catheter. Upon coiling, the first tine and the third tine and pass through the first piece of tissue and upon coiling, the second tine and the fourth tine pass through the second piece of tissue. The first piece of tissue and the second piece of tissue are drawn together upon coiling of the first tine, the second tine, the third tine and the fourth tine. 
         [0026]    In an embodiment, a method is disclosed for treating a patent foramen ovale using a medical clip having a first tine and a third tine coupled to a first end of a bridge segment and a second tine and a fourth tine coupled to a second end of the bridge segment, wherein the first tine, the second tine, the third tine and the fourth tine are each resiliently biased to form a coil. The method comprises the steps of placing a delivery catheter having a lumen containing the medical clip between a first piece of tissue of the patent foramen ovale and a second piece of tissue of the patent foramen ovale, wherein the first tine, the second tine, the third tine and the fourth tine are straightened while in the delivery catheter and deploying the medical clip from the delivery catheter. Upon coiling, the first tine and the third tine and pass through the first piece of tissue of the patent foramen ovale and, upon coiling, the second tine and the fourth tine and pass through the second piece of tissue of the patent foramen ovale. The patent foramen ovale is reduced in size when the first piece of tissue of the patent foramen ovale and the second piece of tissue of the patent foramen ovale are drawn together upon coiling of the first tine, the second tine, the third tine and the fourth tine. 
         [0027]    In an embodiment, the patent foramen ovale is closed upon coiling of the first tine, the second tine, the third tine and the fourth tine coil. 
         [0028]    In an embodiment, a method is disclosed for making a system for drawing together patient tissue using a medical clip. The method comprises the steps of forming the medical clip by coupling a plurality of tines to a bridge segment, each individual one of the plurality of tines being resiliently biased to form a coil, inserting the medical clip into a lumen of a delivery catheter having a distal end such that the plurality of tines are oriented toward the distal end, wherein the plurality of tines uncoil and become approximately linear upon each individual one of the plurality of tines entering the lumen, inserting a deployment mechanism in the lumen of the delivery catheter such that using the deployment mechanism deploys the medical clip out of an end of the lumen. The plurality of tines begin to coil upon being deployed, penetrating the patient tissue and drawing the patient tissue together as each individual one of the plurality of tines form a coil. 
         [0029]    In an embodiment, the inserting the medical clip into the lumen step comprises inserting the bridge segment into the lumen of the delivery catheter and drawing the bridge segment down the lumen at least as far as a length of individual ones of the plurality of tines. 
         [0030]    In an embodiment, the deployment mechanism pushes on the medical clip to deploy the medical clip. 
     
    
     
       DRAWINGS 
         [0031]      FIG. 1  shows a medical clip for drawing together patient tissue; 
           [0032]      FIG. 2  shows the medical clip of  FIG. 1  positioned in a deployment catheter; 
           [0033]      FIG. 3  shows the medical clip of  FIG. 1  deployed from, but still coupled to the deployment catheter; 
           [0034]      FIGS. 4   a - 4   c  illustrate the positioning and deployment of the medical clip of  FIG. 1  for the treatment of a patent foramen ovale; 
           [0035]      FIG. 5  is a flowchart for implanting a medical clip; 
           [0036]      FIG. 6  is a flowchart for making a system including a medical clip positioned in a deployment catheter; 
           [0037]      FIG. 7  shows the medical clip of  FIG. 1  deployed from the deployment catheter with an alternative deployment mechanism; and 
           [0038]      FIG. 8  is a flowchart for explanting a medical clip. 
       
    
    
     DESCRIPTION 
       [0039]    It is often advantageous to capture and draw together pieces of tissue of a patient. Doing so may close and help wounds heal, or close defects in patient organs. Various capture and closure devices exist, but while such devices may be effective in certain situations and under certain conditions, they may be ineffective or disadvantageous in other conditions. Particularly in situations where the tissue to be drawn together is not readily accessible to personal manipulation, commonly known devices are often of limited use. The treatment of cardiac defects may be one such relatively common situation. 
         [0040]    In order to treat cardiac defects such as a patent foramen ovale, it is desirable close the gap between flaps of cardiac tissue without having to experience the trauma and expense of open heart surgery. Accordingly, a medical clip and delivery system has been developed that may be inserted into the heart intravenously. Upon positioning the delivery system within the gap of the patent foramen ovale, a deployment system deploys the medical clip. The physical nature of the medical clip may capture and draw together the flaps of tissue of the patent foramen ovale, thereby reducing or closing the gap between the pieces of tissue altogether. 
         [0041]    An embodiment of a medical clip for treating cardiac defects is illustrated in  FIG. 1 . Clip  10  has bridge section  12 . Four tines  14 ,  16 ,  18 ,  20  project from bridge section  12 . Each tine  14 ,  16 ,  18 ,  20  is comprised of coil  22  and end  24 . In an embodiment, end  24  forms a sharpened tip. In the illustrated embodiment, tines  14 ,  16 ,  18 ,  20  are coupled to bridge section  18 , with two tines  14 ,  16  coupled to end  26  and two tines  18 ,  20  coupled to end  28 . In the illustrated embodiment, bridge section  12  has bulk  20  to which the tines  14 ,  16 ,  18 ,  20  are coupled. 
         [0042]    In various alternative embodiments, the number of tines  14 ,  16 ,  18 ,  20  may be altered based on various criteria. For instance, in some circumstances it may be desirable to have six total tines, such as when an amount of tissue to be captured is relatively large. Increases to eight or more tines may likewise be desirable. Further, it may be advantageous to utilize unequal numbers of tines on opposing sides of clip  10 , for instance when the flaps of tissue to be drawn together are of unequal size. In one embodiment, one side may have two tines while the opposite side may have one tine. Various other combinations of numbers of tines are envisioned. 
         [0043]    In an alternative embodiment, tine  14  and tine  16  are made from a single length of material, and tine  18  and tine  20  are made from a single length of material, forming two tine pairs  32   a,    34   a,  with each tine pair  32   a,    34   a  then being coupled to bridge section  12 . In another alternative embodiment, tine  14  and tine  20  are made from a single length of material, and tine  16  and tine  18  are made from a single length of material, to form two tine pairs  32   b,    34   b . Tine pairs  32   b,    34   b  may then be coupled together at bridge section  12 . Coupling may be accomplished utilizing a weld, adhesive, or by any means of joining the pairs  32   a,    32   b,    34   a,    34   b  suitable for use in a human body. Alternatively, bulk  30  may be coupled to each tine pair  32   b,    34   b,  forming clip  10  and bridge section  12  without coupling tine pairs  32   b,    34   b  together directly. 
         [0044]    Tines  14 ,  16 ,  18 ,  20  may be made from a variety of different materials. Any material may be used such that tines  14 ,  16 ,  18 ,  20  may be resiliently biased to form coil  22  when clip  10  has been deployed, provided the material is biocompatible or may be treated to make it biocompatible. In an embodiment, tines  14 ,  16 ,  18 ,  20  are made from the shaped memory alloy Nitinol. In alternative embodiments, biocompatible elastic material such as stainless steel may be utilized. Biocompatible super-elastic materials may also be utilized. Super-elastic materials could encompass super-elastic plastics and super-elastic metals. A super-elastic plastic generally is any material that has shape memory ability after shaped setting, e.g., materials described in the Massachusetts Institute of Technology, News Office article entitled “Intelligent Plastics Change Shape With Light, dated Apr. 13, 2005, authored by Elizabeth A. Thomson, which is hereby incorporated by references in its entirety. Super-elastic metals are sometimes known as a shape memory alloy (also, smart metal, memory alloy or muscle wire) that remembers its shape and can be returned to that shape after being deformed, by applying heat to the alloy. When the shape memory effect is correctly harnessed, super-elastic metals becomes a lightweight, solid-state alternative to conventional actuators such as hydraulic, pneumatic and motor-based systems. In an embodiment, drawn filled tubes filled with a super-elastic material or materials. 
         [0045]    In a further alternative embodiment, spring-like bioabsorbable material may be utilized, which may result in clip  10  ultimately dissolving. Alternatively, a non-bioabsorbable material may be utilized to form clip  10 , but the material may be coated with biological tissue, bioabsorbable polymer, a therapeutic substance or other substance which may be advantageously delivered to the treatment site concurrent with clip  10 . 
         [0046]    In the illustrated embodiment of  FIG. 1 , coils  22  create a full circular loop, whereby a completed circle is formed because individual tines  14 ,  16 ,  18 ,  20  complete an approximately circular circuit. As illustrated, tines  14 ,  16 ,  18 ,  20  complete one-and-a-quarter revolutions, with the overlap providing potentially enhanced ability to hold tissue over a coil which completes only one full revolution. Alternatively, coils  22  may form only a partial circular loop. In an embodiment, coil  22  may be only three-quarters of a completed circle. In such an embodiment, the tissue captured in coil  22  may be sufficiently secured that the flaps of tissue may be drawn together even without coil  22  forming a completed circle. Alternative partial loops may also be utilized such that the tissue may still be captured and retained by coil  22 . In further alternative embodiments, non-circular loops may also be utilized. Oval or ellipsoid shapes may be utilized advantageously in certain circumstances. Alternatively, shapes with angles such as triangles or rectangles may be utilized. Further, irregular shapes may be utilized. 
         [0047]      FIG. 2  illustrates an embodiment of clip  10  in an embodiment of a deployment catheter  48  having a sheath  50 . To place clip  10  in sheath  50 , bridge section  12  may be drawn into lumen  52  of sheath  50 . As bridge section  12  is drawn in to sheath  50 , coil  22  of each tine  14 ,  16 ,  18 ,  20  is stressed by sheath  50 , causing coil  22  to unwind and each tine  14 ,  16 ,  18 ,  20  to become approximately straight when positioned in sheath  50 . End  24  of each tine  14 ,  16 ,  18 ,  20  remains in proximity of the distal end of sheath  50 . 
         [0048]    Sheath  50  may be coupled to catheter  54  to form deployment catheter  48 . Catheter  54  may be utilized to guide sheath  50  into position to deploy clip  10 . Catheter  54  may also be utilized to deploy clip  10 . In an embodiment, catheter  54  has a deployment mechanism  56  in contact with bridge section  12 . When deployment mechanism  56  pushes bridge section  12 , clip  10  slides along sheath  50  until clip  10  has fully emerged from sheath  50 . 
         [0049]      FIG. 3  illustrates an embodiment of clip  10  fully emerged from sheath  50  but still attached to deployment mechanism  56 . In the illustrated embodiment, tines  14 ,  16 ,  18 ,  20  have returned to their resiliently biased coiled state. In various embodiments of clip  10 , dependent on the material from which tines  14 ,  16 ,  18 ,  20  were made, tines  14 ,  16 ,  18 ,  20  may coil within moments of emerging from sheath  50 , or may require a lengthier amount of time to coil. In certain embodiments, tines  14 ,  16 ,  18 ,  20  may, for a time, remain essentially straight even after bridge section  12  has emerged from sheath  50  due to the length of time required to coil. However, in such an embodiment, tines  14 ,  16 ,  18 ,  20  will eventually coil after clip  10  has deployed from sheath  50 . 
         [0050]      FIGS. 4   a - 4   c  and the flowchart of  FIG. 5  illustrate a use of clip  10  and sheath  50  in the treatment of a patent foramen ovale. Sheath  50  is positioned ( FIG. 5 ,  200 ) in a gap  106  between a first flap of tissue  100  and a second flap of tissue  102  within heart  104  while clip  10  remains in sheath  50  with tines  14 ,  16 ,  18 ,  20  uncoiled ( FIG. 4   a ). As clip  10  is deployed ( FIG. 5 ,  202 ) from sheath  50 , tines  14 ,  16 ,  18 ,  20  begin to coil, with the coiling motion causing ( FIG. 5 ,  204 ) end  24  of tine  14  and tine  20  to pass through tissue  100  and end  24  of tine  16  and tine  18  passing through tissue  102  ( FIG. 4   b ). As tines  14 ,  16 ,  18 ,  20  complete coiling, tissue  100  and tissue  102  are drawn ( FIG. 5 ,  206 ) together by the decrease in the radius of coil  22  as each tine  14 ,  16 ,  18 ,  20  coils. The completion of coiling may draw tissue  100  and tissue  102  completely together and close gap  106  ( FIG. 4   c ). Alternatively, the completion of coiling may draw tissue  100  and tissue  102  nearly together though still leaving a reduced gap  106 . 
         [0051]    The treatment of other cardiac defects, such as atrial-septal defects (“ASD”) and ventricular-septal defects (“VSD”), by the same steps illustrated above is also contemplated. In fact, any patient condition in which it is desirable to join or draw together two flaps of tissue may be effectively treated utilizing the steps illustrated in  FIGS. 4   a - 4   c . While the physical dimensions of clip  10  and delivery catheter  54  may need to change to reflect the different conditions, such as a wider gap  106  or tougher or thicker tissue  100 ,  102 , the method of using clip  10  may remain unchanged. 
         [0052]    In various implementations of the deployment of clip  10 , tissue  100  and tissue  102  may be drawn together even if one or two of tines  14 ,  16 ,  18 ,  20  do not pass through tissue as intended. So long as at least one tine  14 ,  16 ,  18 ,  20  passes through each flap of tissue  100 ,  102 , tissue  100  may be drawn together with tissue  102 . Instances in which all four tines  14 ,  16 ,  18 ,  20  pass through tissue  100 ,  102  may, however, create the highest likelihood of maximizing the amount of tissue  100 ,  102  brought together. 
         [0053]    The geometry of the components of clip  10  influence performance of clip  10 . Relatively longer tines  14 ,  16 ,  18 ,  20  and relatively greater diameter of coil  22  may allow for the treatment of a relatively larger gap  106 , or result in greater depth of penetration of tissue  100 ,  102 , perhaps increasing the likelihood of closing gap  106  altogether. A relatively longer length of bridge section  12  may result in an increased area of tissue  100 ,  102  that is drawn together, thereby increasing the tissue area brought together, aiding in the ultimate sealing of the foramen ovale. And a relatively greater diameter of the material comprising tines  14 ,  16 ,  18 ,  20  may increase the ability of tines  14 ,  16 ,  18 ,  20  to hold tissue  100 ,  102  and decrease the likelihood of tissue  100 ,  102  slipping out of tines  14 ,  16 ,  18 ,  20  during or after coiling. In an embodiment, the dimensions of coil  22  is approximately 0.090 inches, the length of bridge section  12  is 0.070 inches, and the diameter of tines  14 ,  16 ,  18 ,  20  is 0.014 inches. In alternative embodiments, coil  22  may range from 0.050 inches to 0.125 inches, bridge section  12  may range from 0.050 inches to 0.25 inches, and the diameter of times  14 ,  16 ,  18 ,  20  may range from 0.008 inches to 0.018 inches. 
         [0054]      FIG. 6  is a flowchart of a method for making a system in which an embodiment of medical clip  10  is positioned in deployment catheter  48 . Medical clip  10  is formed ( 300 ) by coupling tines  14 ,  16 ,  18 ,  20  to bridge section  12 . Medical clip  10  is inserted ( 302 ) into lumen  52  of delivery catheter  48 . In an embodiment, bridge section  12  is inserted into lumen  52  first, followed by tines  14 ,  16 ,  18 ,  20 . As the insertion occurs, tines  14 ,  16 ,  18 ,  20  uncoil until they are approximately linear within lumen  52 . Deployment mechanism  56  is inserted ( 304 ) into lumen  52 , such that when the deployment mechanism is used, medical clip  10  deploys out of lumen  52  and tines  14 ,  16 ,  18 ,  20  coil. In embodiments where deployment mechanism  56  is coupled to medical clip  10 , coupling deployment mechanism  56  to medical clip  10  may occur either before or after insertion of medical clip into delivery catheter  48 . When coupling occurs before insertion of medical clip  10 , deployment mechanism  56  may be utilized to insert medical clip  10  into deployment catheter  48  by pulling medical clip into lumen  52 . 
         [0055]      FIG. 7  illustrates an alternative embodiment of deployment mechanism  154 . In contrast with deployment mechanism  54  ( FIGS. 2 and 3 ), which may deploy medical clip  10  simply by pushing on medical clip  10  until it emerges from sheath  50 , deployment mechanism  154  may engage bridge section  12  in notch  156 . With bridge section  12  deployed in notch  156 , medical clip  10  may be deployed from sheath  50 , or may be retracted back into sheath  50  by engaging medical clip  10 , e.g., bridge segment  12 , in notch  156  and drawing deployment mechanism  154  back into sheath  50 . In various embodiments, deployment mechanism  154  may be utilized to secure and retract medical clip  10  after medical clip  10  has been fully deployed into tissue  100 ,  102  ( FIG. 4 ) by engaging bridge section  12  in notch  156  and exerting a pulling force using deployment mechanism  154 . Alternative embodiments of deployment mechanism  154  may utilize clamps, magnets, or any other selectively engageable fastening mechanism to engage medical clip  10  with deployment mechanism  154  such that medical clip  10  may be retracted into sheath  50 . 
         [0056]      FIG. 8  is a flow chart of a method of explanting a medical clip  10  deployed in tissue  100 ,  102 , as illustrated in  FIG. 4   c . Deployment catheter  48  is positioned ( 400 ) in proximity of bridge section  12  of medical clip  10 . Deployment mechanism  154  engages ( 402 ) bridge section  12 . As retraction force is exerted ( 404 ) on deployment mechanism  154  bridge section  12  moves away from tissue  100 ,  102  and tines  14 ,  16 ,  18 ,  20  begin uncoiling. Ultimately, tines  14 ,  16 ,  18 ,  20  disengage ( 406 ) from tissue  100 ,  102  and medical clip may be fully retracted ( 408 ) into sheath  50 . 
         [0057]    Thus, embodiments of the devices, system and methods of drawing patient tissue together are disclosed. One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow.