Patent Publication Number: US-2011077683-A1

Title: Puncture closure apparatuses, sealing plugs, and related methods

Description:
RELATED APPLICATION 
     This is a divisional of U.S. patent application Ser. No. 11/419,941 filed on 23 May 2006, now pending, the disclosure of which is incorporated, in its entirety, by this reference. 
    
    
     TECHNICAL FIELD 
     This relates generally to medical devices and more particularly to methods and devices for sealing punctures or incisions in a tissue wall 
     BACKGROUND 
     Various surgical procedures are routinely carried out intravascularly or intraluminally. For example, in the treatment of vascular disease, such as arteriosclerosis, it is a common practice to invade the artery and insert an instrument (e.g., a balloon or other type of catheter) to carry out a procedure within the artery. Such procedures usually involve the percutaneous puncture of the artery so that an insertion sheath can be placed in the artery and thereafter instruments (e.g., a catheter) can pass through the sheath and to an operative position within the artery. Intravascular and intraluminal procedures unavoidably present the problem of stopping the bleeding at the percutaneous puncture after the procedure has been completed and after the instruments (and any insertion sheaths used therewith) have been removed. Bleeding from puncture sites, particularly in the case of femoral arterial punctures, is typically stopped by utilizing vascular closure devices, such as those described in U.S. Pat. Nos. 6,179,963; 6,090,130; and 6,045,569 and related patents, which are hereby incorporated by this reference. 
     Typical closure devices such as the ones described in the above-mentioned patents place a sealing plug at the tissue puncture site. Nevertheless, the incision track leading to the invaded artery often continues to ooze blood from side vessels at the puncture site. Manual compression is typically applied at the puncture site to stop the track bleeding. Manual compression can lead to patient soreness and requires additional time from medical personnel. The time spent by medical personnel compressing the puncture site to stop the bleeding from the incision track can be expensive to the patient, and tiring to the medical personnel. Accordingly, there is a need for improving the sealing methods and apparatus at the site of subcutaneous tissue punctures. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention relates to a puncture closure device. Particularly, a puncture closure device may include an anchor support including a coupling feature and an anchor connected to the anchor support, wherein the anchor is configured for insertion through a puncture. Further, the puncture closure device may include a movable compression element configured to be movable between a first position and a second position, wherein movement of the compression element to the second position causes coupling of the compression element to the coupling feature of the anchor support and a sealing plug positioned generally between the compression element and the anchor. The compression element may be configured to cause compression of the sealing plug generally between the compression element and the anchor upon movement of the compression element from the first position to the second position. A puncture closure assembly may comprise a puncture closure device and an insertion sheath configured to receive at least a portion of the puncture closure device. 
     Another aspect of the present invention relates to a method of compressing a sealing plug. Particularly, a bore of a sealing plug may be positioned generally about a portion of an anchor support, wherein the anchor support is connected to an anchor and the sealing plug may be longitudinally compressed. A further aspect of the present invention relates to a method of sealing a puncture. More specifically, an anchor may be positioned generally within a puncture, the anchor connected to an anchor support. Further, a bore of a sealing plug may be positioned generally about a portion of an anchor support. In addition, the sealing plug may be longitudinally compressed generally between the anchor and a compression element. 
     An additional aspect of the present invention relates to a sealing plug for use in a puncture closure apparatus. In one embodiment, a sealing plug may comprise a first end region, a second end region, and an intermediate region positioned between the first end region and the second end region, wherein the intermediate region comprises a material with a density less than a density of the first end region and a density of the second end region. In another embodiment a sealing plug may comprise a generally cylindrical body including a bore formed therethrough and a plurality of slits formed into an exterior surface of the sealing plug, the plurality of slits configured to facilitate radial expansion of the sealing plug in response to longitudinal compression of the sealing plug. 
     Features from any of the above mentioned embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the instant disclosure will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features of the subject matter of the present invention, its nature, and various advantages will be more apparent from the following detailed description and the accompanying drawings, which illustrate various exemplary embodiments, are representations, and are not necessarily drawn to scale, wherein: 
         FIG. 1  shows a side view, partly in section, of a conventional puncture closure device; 
         FIG. 2  shows a schematic side view of the puncture closure device shown in  FIG. 1  inserted through an insertion sheath and engaged with a blood vessel; 
         FIG. 3  shows a schematic side view of the conventional puncture closure device as shown in  FIG. 2 , wherein the conventional puncture closure device and insertion sheath are being withdrawn from the artery to deploy a sealing plug; 
         FIG. 4  shows a side view of the conventional puncture closure device, as shown in  FIG. 3 , illustrating use of a tamping tube to tamp the sealing plug; 
         FIG. 5  shows a schematic perspective view of a puncture closure device according to the present invention; 
         FIG. 6  shows a perspective view of one embodiment of an assembly of an anchor and an anchor support; 
         FIG. 7  shows a side cross-sectional view of one embodiment of an anchor and a anchor support, wherein the anchor is pinned to the anchor support; 
         FIG. 8  shows a side cross-sectional view of another embodiment of an anchor and an anchor support, wherein the anchor is pivotably coupled to the anchor support by a suture; 
         FIG. 9  shows a perspective view of one embodiment of a sealing plug for use with a tissue puncture closure device according to the present invention; 
         FIG. 10  shows a perspective view of another embodiment of a sealing plug for use with a tissue puncture closure device according to the present invention; 
         FIG. 11  shows a perspective view of a further embodiment of a sealing plug for use with a tissue puncture closure device according to the present invention; 
         FIG. 12  shows a perspective view of an additional embodiment of a sealing plug for use with a tissue puncture closure device according to the present invention; 
         FIG. 13  shows a partial side view, partly in section, of an internal tissue puncture closure device prior to deployment of a plug assembly; 
         FIG. 14  shows a partial side view, partly in section, of the internal tissue puncture closure device shown in  FIG. 13  following deployment of the plug assembly; 
         FIG. 15  shows a perspective view of a plug assembly prior to deployment according to the invention; 
         FIG. 16  shows a perspective view of the plug assembly shown in  FIG. 15  after deployment; 
         FIG. 17  shows a partial side cross-sectional view of a puncture closure device during use; 
         FIG. 18  shows a partial side cross-sectional view of a puncture closure device shown in  FIG. 17 , wherein the sealing plug has been longitudinally compressed and radially expanded; and 
         FIG. 19  shows perspective view of a plug assembly deployed partially within a tissue tract and partially within a blood vessel to effectively close a puncture formed in the blood vessel. 
         FIG. 20  is a perspective view of another embodiment of a puncture closure device prior to deployment. 
         FIG. 21A  is a partial cross-sectional view of the puncture closure device shown in  FIG. 20 . 
         FIGS. 21B-21D  illustrate stages of deployment of the puncture closure device shown in  FIG. 21A . 
         FIG. 22  is perspective view of another embodiment of a puncture closure device prior to deployment. 
         FIGS. 23A and 23B  illustrate stages of deployment of the puncture closure device shown in  FIG. 22 . 
     
    
    
     Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. 
     DETAILED DESCRIPTION 
     As mentioned above, vascular procedures are conducted throughout the world and require access to an artery through a puncture. Most often, the artery is a femoral artery. To close the puncture following completion of the procedure, many times a closure device is used to sandwich the puncture between an anchor and a sealing plug. However, sometimes the sealing plug is difficult to eject from the sealing device and may not properly seat against an exterior situs of the arteriotomy. If the plug does not seat properly against the arteriotomy, there is a potential for elongated bleeding. The present disclosure describes methods and apparatus that facilitate placement and sealing of tissue punctures. While the vascular instruments shown and described below include procedure sheaths and puncture sealing devices, the application of principles described herein are not limited to the specific devices shown. The principles described herein may be used with any medical device. Therefore, while the description below is directed primarily to arterial procedures and certain embodiments of a puncture closure device, the methods and apparatus are only limited by the appended claims. 
     The term “tissue,” as used herein, means an aggregation of morphologically similar cells and associated intercellular matter acting together to perform one or more specific functions in a body. The term “lumen,” as used herein, means any open space or cavity in a bodily organ, especially in a blood vessel. The terms “tamp” or “tamping,” as used herein, mean pushing or packing by one or a succession of pushes, blows, or taps. The term “biologically resorbable material,” as used herein, means a material capable of degradation by biological processes such as collagen, synthetic collagen, polymerized polylactic acid, polyglycolic acid matrix, or any other bioabsorbable material. The words “including” and “having,” as used in the specification, including the claims, have the same meaning as the word “comprising.” 
     Referring now to the drawings, and in particular to  FIGS. 1-4 , a vascular puncture closure device  100  is shown according to the prior art. The vascular puncture closure device  100  includes a carrier tube  102  with a filament or suture  104  extending at least partially therethrough. The closure device  100  also includes a first or proximal end  106  and a second or distal end  107 . External to a second or distal end  107  of the carrier tube  102  is an anchor  108 . The anchor is an elongated, stiff, low profile member including an eye  109  formed at the middle. The anchor  108  is typically made of a biologically resorbable polymer. 
     The suture  104  is threaded through the anchor  108  and back to a collagen pad  110 . The collagen pad  110  may comprise randomly oriented fibrous material bound together by chemical means. The collagen pad  110  is slidingly attached to the suture  104  as the suture passes distally through the carrier tube  102 , but as the suture traverses the anchor  108  and reenters the carrier tube  102 , it is securely slip knotted proximal to the collagen pad  110  to facilitate cinching of the collagen pad  110  when the closure device  100  is properly placed and the anchor  108  deployed (see  FIG. 4 ). The carrier tube  102  typically includes a tamping tube  112  disposed therein. The tamping tube  112  is slidingly mounted on the suture  104  and may be used by an operator to tamp the collagen pad  110  toward the anchor  108  at an appropriate time to seal a percutaneous tissue puncture. 
     Prior to deployment of the anchor  108  within an artery, the eye  109  of the anchor  108  rests outside the distal end  107  of the carrier tube  102 . The anchor  108  may be temporarily held in place flush with the carrier tube  102  by a bypass tube  114  disposed over the distal end  107  of the carrier tube  102 . The flush arrangement of the anchor  108  and carrier tube  102  allows the anchor  108  to be inserted into a procedure sheath such as insertion sheath  116  as shown in  FIGS. 2-4 , and eventually through an arterial puncture  118 . The insertion sheath  116  is shown in  FIGS. 2-4  inserted through a percutaneous incision  119  and into an artery  128 . However, the bypass tube  114  ( FIG. 1 ) includes an oversized head  120  that prevents the bypass tube  114  from passing through an internal passage of the insertion sheath  116 . Therefore, as the puncture closure device  100  is inserted into the insertion sheath  116 , the oversized head  120  bears against a surface  122  of insertion sheath  116 . Further insertion of the puncture closure device  100  results in sliding movement between the carrier tube  102  ( FIG. 1 ) and the bypass tube  114 , releasing the anchor  108  from the bypass tube  114  ( FIG. 1 ). However, the anchor  108  remains in the flush arrangement shown in  FIG. 1  following release from the bypass tube  114 , limited in movement by the insertion sheath  116 . 
     The insertion sheath  116  includes a monofold  124  at a second or distal end  126  thereof. The monofold  124  acts as a one-way valve to the anchor  108 . The monofold  124  is a plastic deformation in a portion of the insertion sheath  116  that elastically flexes as the anchor  108  is pushed out through the distal end  126  of the insertion sheath  116 . Typically, after the anchor  108  passes through the distal end  126  of the insertion sheath  116  and enters the artery  128 , the anchor  108  is no longer constrained to the flush arrangement with respect to the carrier tube  102  and it deploys and rotates to the position shown in  FIG. 2 . 
     Referring next to  FIGS. 3-4 , with the anchor  108  deployed, the puncture closure device  100  and the insertion sheath  116  are withdrawn together, ejecting the collagen pad  110  from the carrier tube  102  into the incision tract  119  and exposing the tamping tube  112 . With the tamping tube  112  fully exposed as shown in  FIG. 4 , the collagen pad  110  is manually tamped, and the anchor  108  and collagen pad  110  are cinched together and held in place with the self-tightening slip-knot on the suture  102 . Thus, the tissue puncture is sandwiched between the anchor  108  and the collagen pad  110 , thereby sealing the tissue puncture  118 . The suture  104  is then cut and the incision tract  119  may be closed. The suture  104 , anchor  108 , and collagen pad  110  are generally made of resorbable materials and therefore remain in place while the puncture  118  heals. 
     Using the typical tissue puncture closure device  100  described above, however, it may be difficult to adequately tamp the collagen pad  110 . Tamping cannot commence until the sheath  116  has been removed so as to expose the tamping tube  112  for manual grasping. Under certain conditions, removal of the sheath  116  prior to tamping the collagen pad  110  causes the collagen pad  110  to retract or displace proximally from the tissue puncture  118 , creating an undesirable gap  120  between the collagen pad  110  and the puncture  118 . The gap  120  may remain even after tamping as shown in  FIG. 4 , and sometimes results in only a partial seal and bleeding from the tissue puncture  118 . 
     Therefore, the present specification describes an methods and apparatuses including a tissue puncture closure device that may provide a stable seal at the tissue puncture site. The tissue puncture closure device may include an anchor attached to a rigid support with a sealing plug movably disposed thereover. 
     Generally, one aspect of the present invention described herein relates to a puncture closure device including a movable compression element configured to compress and deform a sealing plug within a tissue tract of a patient. More particularly, in one embodiment, a puncture closure device may include an anchor, an anchor support, and a movable compression element. Further, the movable compression element may be configured to compress the sealing plug and lock, contact, or couple to the anchor support upon moving to a selected position. Such a configuration may provide repeatability in the compression of the sealing plug and may provide a relatively unobtrusive closure assembly which may be deployed within a patient. 
       FIG. 5  shows one embodiment of a puncture closure device  200  according to principles of the present invention. The puncture closure device  200  may have particular utility when used in connection with intravascular procedures, such as angiographic dye injection, cardiac catheterization, balloon angioplasty and other types of vascular access of atherosclerotic arteries, etc., as may be appreciated with respect to use of the puncture closure device  200  to effectively close vascular incisions as described below. However, it will be understood that while the description of the embodiments below are directed to closure of percutaneous punctures in blood vessels, such devices have much more wide-spread applications and can be used for sealing punctures or incisions in other types of tissue walls and tissues as well. Thus, the sealing of a percutaneous puncture in a blood vessel, as shown and discussed herein, is merely illustrative of one particular application of the apparatuses and methods of the present invention. 
     As shown in  FIG. 5 , the puncture closure device  200  includes a proximal end  206  and a distal end  207 . A plug assembly  204  is positioned generally near the distal end  207  and includes an anchor  208 , an anchor support  210 , a coupling feature  226 , a sealing plug  240 , and a compression element  280 . The sealing plug  240  may comprise any biologically resorbable material (e.g., collagen, polyglycolic acid, etc.), as known in the art. For example, sealing plug  240  may comprise a sponge-like material (e.g., naturally occurring collagens, synthetic collagens, or other biologically resorbable sponge-like material), a foam, or a fibrous material, and may be configured in any shape to facilitate sealing the puncture  218 . The sealing plug may also include a hemostatic agent, such as a tissue thromboplastin, to accelerate local hemostasis. Anchor support  210  includes a proximal end  222  and distal end  224  which, optionally, may be coincident with the distal end  207  of the closure device  200 . As shown in  FIG. 5 , the anchor  208  is positioned at least partially within a recess  212  of the anchor support  210  to facilitate insertion into a lumen of a blood vessel. In further detail,  FIG. 6  shows a perspective view of anchor support  210  and anchor  208  according to one embodiment. Anchor  208  may be pivotably coupled to anchor support  210 . Put another way, anchor  208  may be coupled to anchor support  210  so that anchor  208  may pivot generally about an axis of rotation  209 . As shown in  FIG. 6 , anchor  208  includes a body that is elongated along an axis of elongation  211 , which, optionally, may be oriented substantially perpendicularly with respect to axis of rotation  209 . Of course, many different embodiments for anchor  208  and anchor support  210  are contemplated by the present invention. For example,  FIGS. 7 ,  8 ,  20 , and  22  show different embodiments of an assembly including an anchor and an anchor support. In one embodiment, anchor  208  may be coupled to the anchor support  210  with a pin  260  shown in  FIG. 7 . Pin  260  passes through a hole  264  formed through anchor support  210  and an eyelet aperture  262  formed through a portion of anchor  208 . In another embodiment shown in  FIG. 8 , anchor  208  may be coupled to the anchor support  210  with a suture  266  or any other relatively flexible member which can be attached or molded to the anchor support  210 . In the separate embodiments shown in of  FIGS. 20 and 22 , anchor support  210  may have the suture  266  attached or molded to a distal end  224 . The suture  266  attaches the anchor support  210  to the anchor  208 . The anchor  208  may be initially arranged in a nest  267  formed in the anchor support  210  at the distal end  224 . 
     In the embodiments of  FIGS. 7 ,  8 ,  20 , and  22 , the anchor  208  may be configured to be positioned inside a blood vessel and against a wall of the blood vessel. Further, the anchor  208  may be configured to be generally centered with respect to a puncture formed through a wall of a blood vessel. The anchor  208  may comprise an elongated, low-profile member (i.e., with respect to a distance inwardly from the wall of a blood vessel) and may comprise a relatively stiff (e.g., exhibiting a relatively high modulus of elasticity) material. In addition, the anchor  208  may comprise a biologically resorbable material such as, for example, a mixture of approximately 50% lactide and 50% glycolide material. The anchor support  210  may also comprise a biologically resorbable material such as, for example, collagen or polyglycolic acid (PGA). 
     As shown the embodiments of  FIGS. 7 ,  8 ,  20 , and  22  anchor support  210  includes first or proximal end  222  and second or distal end  224 . Coupling feature  226  (shown in  FIGS. 7 ,  8 ,  20  and  22  as an annular groove) may be located near first end  222  of anchor support  210 . Anchor support  210  tends to hold its shape and may be substantially rigid. Anchor support  210  defines a rigid support to which the anchor  208  is mounted. Anchor support  210  may be referred to as a rigid support member and have a rigid portion. Anchor support  210  is shown in at least  FIG. 7  having a generally elongate construction and may be referred to as a generally rigid elongated member. Anchor support  210  comprises a bioabsorbable material and may include a hemostasis promoting material. Generally, coupling feature  226  may be configured for selectively engaging an associated coupling feature of a movable compression element, as described in greater detail below. As shown in  FIGS. 7 ,  8 ,  20  and  22 , the coupling feature  226  may be a groove indented into anchor support  210  that is substantially concentric with respect to the body of anchor support  210  and may be positioned anywhere along the outside surface of the anchor support. In the embodiments of  FIGS. 7 ,  8 ,  20  and  22  the coupling feature  226  is arranged proximate to the first end  222  of the anchor support  210 . Thus, it may be appreciated that in some embodiments, a mating device such as suitably sized retaining ring or disc-shaped member may be moved along the first end  222  of anchor support  210  and positioned at least partially within coupling feature  226 . It should be noted that the retaining ring or disc-shaped member is not necessarily closed, it may comprise a partial ring or disc. Such a configuration may effectively couple the suitably sized ring or disc to the coupling feature  226 . Of course, many different interlocking, coupling, contacting, and engaging structures (e.g., tabs, slots, threads, protrusions, recesses, snap-fittings, etc.) may be employed as a coupling feature  226  in cooperation with an associated coupling feature of a mating device such as a movable compression element (discussed below). 
     As further shown in  FIGS. 7 and 8 , anchor support  210  may optionally include a cavity  214  defining an opening at the first end  222  of anchor support  210  that extends toward second end  224 . In one embodiment, cavity  214  may include one or more substantially cylindrical regions  270  and one or more non-cylindrical regions  272 . Non-cylindrical regions  272  may be substantially conical or substantially spherical in shape. The non-cylindrical regions  272  may form diverging/converging cones as shown in  FIGS. 7 and 8 . 
     Referring again to  FIG. 5 , prior to deployment of the plug assembly  204  within a tissue tract, the anchor support  210  may be positioned adjacent to a placement rod  202  at the first end  222  of the anchor support  210 . Sealing plug  240  may be initially substantially concentrically positioned with respect to placement rod  202  as shown in  FIG. 5 , and may also be slidably connected or radially adjacent to anchor support  210  as shown in  FIGS. 20 and 22 . Put another way, a bore may be formed through sealing plug  240  and placement rod  202  or anchor support  210  may be positioned within the bore of the sealing plug  240 . Optionally, sealing plug  240  may at least partially interfere (i.e., an interference fit) with the exterior of placement rod  202  or anchor support  210  to provide a snug fit such that the sealing plug  240  tends to remain in place until acted upon by a force exceeding the frictional force between the sealing plug  240  and the placement rod  202  or the anchor support  210 . However, a compression element such as a slideable collar  280  may be arranged around the placement rod  202  or the anchor support  210  proximal of the sealing plug. The slideable collar  280  can be moved to cause movement and/or compression of the sealing plug  240  as discussed in more detail below. 
     Further, placement rod  202  may extend from the first end  206  of the puncture closure device  200  to the anchor support  210  through a tamper  217  and through a sheath  216 . Tamper  217  is also positioned within sheath  216  and abuts slideable collar  280 . Tamper  217  has an outer diameter that is larger than an inner diameter of the slideable collar  280  (or an inner diameter that is smaller than an outer diameter of the slideable collar  280 ) so that an operator may apply a force to the tamper  217  and advance the compression element  280  along the placement rod  202  and/or the anchor support  210  in the direction of the second end  224  of the plug assembly  204 . In one embodiment depicted in  FIG. 5 , slideable collar  280  may be substantially concentrically disposed about (e.g., about a circumference of) placement rod  202  and adjacent to sealing plug  240 . In embodiments depicted in  FIGS. 20 and 22 , however, the sealing plug  240  is radially adjacent to or substantially concentrically disposed about the anchor support  210 . The slideable collar  280  may be substantially concentrically arranged about the anchor support or the placement rod  202 . Slideable collar  280  is moveably arranged with respect to placement rod  202  or anchor support  210 . During deployment of the plug assembly  204 , slideable collar  280  may be moved along the placement rod  202  and/or the anchor support  210  until entering, contacting, locking with, or engaging coupling feature  226 . As the slideable collar  280  advances distally, it contacts, moves, compresses, and/or deforms the sealing plug  240 . If the sealing plug is not already arranged adjacent to the anchor  208 , the slideable collar  280  moves the sealing plug toward the anchor and may cause the sealing plug  240  to buckle or expand radially as it is compressed. Radial expansion of the sealing plug  240  may promote sealing of a puncture between the anchor element  208  and the sealing plug  240 . 
     It will be appreciated by one of ordinary skill in the art having the benefit of this disclosure that prior to a successful deployment of the sealing plug, an insertion sheath may be properly positioned within a blood vessel (or another selected lumen). Proper placement of an insertion sheath may be accomplished with the aid of a puncture locator. Explaining further, according to one aspect, a puncture locator and insertion sheath are inserted through the hole in the vessel wall. The puncture locator may provide fluid communication path from a distal tip (where the insertion sheath enters the vessel) to a proximal end, where blood flow can be observed by an operator or the puncture locator may otherwise indicate proper placement of the distal tip within a blood vessel. Proper placement of the insertion sheath enables proper placement of the sealing plug or insertion of a vascular tool for another purpose. Any locating device and method may be used in conjunction with a puncture closure device according to principles described herein. 
     Turning to  FIGS. 9-11 , various embodiments of the sealing plug  240  are shown in respective perspective views. The sealing plug  240  may encompass any number of configurations, including the ones shown in  FIGS. 9-11  that promote compression of the sealing plug  240  generally along longitudinal axis  201 . Compression of the sealing plug  240  as shown in  FIGS. 9-11  tends to cause the radial outward expansion with respect to longitudinal axis  201 . When used in a puncture tract, such compression may cause sealing plug  240  to expand radially outwardly and sealingly engage or contact tissue surrounding the sealing plug  240 . As shown in  FIGS. 9-11 , an end region  242  of the sealing plug  240  may comprise a relatively dense matrix of bioabsorbable material and may be positioned longitudinally adjacent to (along interfacial surface  254 ) an intermediate region  246  comprising a less dense bioabsorbable material than the end region  242 . Intermediate region  246  is adjacent (along interfacial surface  256 ) an end region  244  comprising another relatively dense matrix of bioabsorbable material. Bore  248  may be formed through each of end regions  242 ,  244 , and intermediate region  246 . Further, bore  248  may be substantially centered about longitudinal axis  201 . Regions  242  and  244 , respectively, may be configured to facilitate compaction of layer  246  and corresponding radial expansion of region  246  by application of a compressive force between end regions  242  and  244  (i.e., toward intermediate region  246 ). Furthermore, as shown in  FIG. 9 , a plurality of slits such as substantially linear slits  250  may be formed at least partially into region  246  and may extend at least partially between interfacial surfaces  254  and  256 . Optionally, linear slits  250  may be substantially parallel. Such linear slits  250  may promote radial expansion of region  246  in response to compression. Particularly, linear slits  250  may substantially inhibit or reduce development of hoop stress within region  246  that may resist radial expansion of region  246 . In one embodiment shown in  FIG. 10 , a plurality of arcuate (e.g., helical) slits  252  may be formed at least partially into region  246  between interfacial surfaces  254  and  256 . Also, as shown in  FIG. 10 , the plurality of arcuate slits  252  may extend substantially parallel to one another. In one embodiment, the plurality of arcuate slits  252  may extend in an intersecting (e.g., a so-called crisscross) fashion, may be unevenly spaced, or may be of unequal length. In one embodiment depicted in  FIG. 11 , sealing plug  240  may comprise end region  242 , intermediate region  246 , and end region  244  with no slits. In yet another embodiment depicted in  FIG. 12 , the sealing plug  240  may comprise uniform material  247 . Of course, optionally, the sealing plug  240  may include linear slits, arcuate slits, or combinations of linear and arcuate slits as may be desired. Also, as shown in  FIGS. 9-11 , sealing plug  240  may be substantially cylindrical and a bore formed through the sealing plug  240  may also be substantially cylindrical. As mentioned above, sealing plug  240  can be made of animal derived collagens or synthetic type materials. Bore  248  of sealing plug  240  may be either molded, punched, machined, or otherwise formed. Although the sealing plug  240  is shown in  FIGS. 9-12  as substantially cylindrical, any other shape may be used. 
     The bore formed through a bioabsorbable sealing plug may provide a structure that facilitates positioning of the sealing plug with respect to an anchor. Such a configuration may reduce the tamping distance applied to compress a sealing plug. Such a configuration may also reduce or eliminate tearing of a sealing pad during tamping and may promote more reproducible and reliable tamping and compression of a sealing plug. 
     More particularly, turning to  FIG. 13 , a portion of the puncture closure device  200  is shown in an initial or “ready to deploy” configuration, wherein each of the anchor support  210 , sealing plug  240 , tamper  217 , and placement rod  202  are generally aligned along longitudinal axis  201 . Following insertion of anchor  208  through a percutaneous tissue incision and into an arterial puncture or other lumen, the anchor  208  may be caused to rotate to the position shown in  FIG. 14 , such that its wings  238 ,  239  are arranged adjacent to an internal wall of the lumen to anchor puncture closure device  200  to the tissue breach (similar to the position of anchor  108  as shown in  FIG. 2 ). The puncture closure device  200  may be twisted and/or pulled in a proximal direction to facilitate rotation of the anchor  208  to engage the lumen. Similar to the above-described operation of a conventional puncture closure device  100 , the sheath  216  houses a tamper  217  for advancing the slideable collar  280  along the placement rod  202  toward the coupling feature  226  and toward the anchor  208 . Tamper  217  may be driven manually (i.e., by hand) or with an automatic driving system to force slideable collar  280  toward the anchor  208 . Accordingly, slideable collar  280  may engage or abut sealing plug  240  at a first or proximal end  281  of the sealing plug  240  to move the sealing plug  240  generally along longitudinal axis  201 . Such movement of sealing plug  240  may be substantially concentric with respect to the placement rod  202  (and/or the support anchor  210 ). Further, such movement of sealing plug  240  may cause the bore of sealing plug  240  to become positioned about (e.g., substantially concentrically) at least a portion of the anchor support  210 . Force applied to slideable collar  280  may compress sealing plug  240 , as shown in  FIG. 14 . As the sealing plug  240  is compressed longitudinally generally between anchor  208  and slideable collar  280 , it correspondingly expands radially against the surrounding tissue to secure the anchor  208  and seal a puncture. In two embodiments shown in  FIGS. 20 and 22 , a protruding lip  213  arranged on the anchor support  210  may limit the travel of the sealing plug  210  toward the anchor  208 . In other embodiments, sealing plug  210  travel is only limited by the anchor  208 . 
     In addition, the slideable collar  280  may be configured to couple to the coupling feature  226  formed in anchor support  210 . More specifically, in one embodiment, the inner circumference of slideable collar  280 , as shown in  FIGS. 15-16  may include a plurality of inward radial protrusions  284 . As slideable collar  280  moves toward and passes onto anchor support  210 , sealing plug  240  is longitudinally compressed and radially expands in proximity to anchor  208 . When slideable collar  280  reaches coupling feature  226 , the plurality of protrusions  284  expand into and are captured (e.g., within a groove as shown in  FIG. 15 ) or otherwise coupled to or locked in position with respect to the coupling feature  226 . Slideable collar  280  may comprise a biologically resorbable material made of the materials mentioned above or others. In one embodiment shown in  FIG. 20 , the slideable collar  280  does not include inward radial protrusions  285 . The slideable collar  280  is elastically expanded from a normal diameter to fit around the anchor support  210 . When the slideable collar  280  reaches the coupling feature  226 , it springs closer to or back to its normal diameter and resists removal from the coupling feature  226 . In one embodiment shown in  FIGS. 22-23B , the slideable collar  280  includes a pair of leg members  283  which are biased to press against the anchor support  210  as the slideable collar  280  is moved distally therealong. As shown in  FIGS. 23A-23B , the leg members  283  abut the sealing plug  240  as the slideable collar  280  is advanced by the tamper  217  and assist in expanding the sealing plug. 
     Embodiments disclosed above may provide substantial centering of a sealing plug with respect to an anchor. Such configurations may facilitate proper positioning of the plug assembly  204  with respect to an arteriotomy. In addition, the embodiments described above may provide more reproducible and reliable tamping and less tearing of the sealing plug. Also, some of the disclosed embodiments which deposit a sealing plug assembly may eliminate the need to cut a suture near the surface of the patient&#39;s skin. Eliminating the need cut a suture may also reduce the risk of tissue tract infections by reducing or eliminating foreign material near the tissue tract opening. 
     Once the sealing plug  240  has been compressed, in some embodiments everything but the plug assembly  204  is removed from the tissue tract. Therefore, anchor support  210  may be operably and releasably connected to placement rod  202 . A fastener, including, but not limited to: a threaded screw, a hook, an elastomeric stopper, an inflatable stopper, or the like, may be employed to selectively couple (and decouple) anchor support  210  to placement rod  202 . In one embodiment depicted in  FIG. 17 , placement rod  202  may operably connect to anchor support  210  with a plug  276  positioned generally within cavity  214  and affixed to filament  274  (e.g., a suture, cord, hose, or other slender member). Plug  276  may be pliant and, therefore, may be forced into cavity  214  or removed therefrom. As shown in  FIG. 17 , filament  274  may extend through bore  278  of placement rod  202  and may be accessible to a user of the puncture closure device  200 . Thus, placement rod  202  may be coupled to anchor support  210  if filament  274  is coupled to placement rod  202  and plug  276  is arranged inside cavity  214 . The coupling of placement rod  202  to anchor support  210  may inhibit retracted longitudinal (i.e., away from anchor  208 , along longitudinal axis  201 ) movement of the placement rod  202  with respect to anchor support  210 . Plug  276  may be elastomeric and shaped to resist removal from cavity  214  under normal conditions of placing the plug assembly  204 . Moreover, in one embodiment, filament  274  may comprise a fluid conducting tube which may be pressurized to inflate plug  276  into an expanded shape and couple placement rod  202  to anchor support  210 . 
     Likewise, anchor support  210  may be selectively released from placement rod  202 . In one embodiment, following deployment of the plug assembly  204  and coupling of slideable collar  280  to coupling feature  226  (as depicted in  FIG. 18 ), placement rod  202  can be disconnected from the anchor support  210 . As described above, plug  276  may be pliant, compressible, or otherwise configured so that when a force exceeding a selected minimum force is applied to filament  274  in a retraction direction (i.e., away from anchor  208 ), the plug  276  deforms to pass through the upper cylinder segment  270  of cavity  214 . In embodiments wherein filament  274  comprises a fluid conducting tube, plug  276  may be deflated to be removed from cavity  214 . Thus, placement rod  202  and anchor support  210  may be selectively connected and disconnect as desired. 
     In one embodiment, after the slideable collar  280  is coupled to coupling feature  226  and the placement rod  202  is disconnected from the anchor support  210 , each of the placement rod  202 , the tamper  217 , the filament  274 , the plug  276  and the sheath  216  may be withdrawn from percutaneous tissue defining an incision. More particularly, from the foregoing discussion, it may be appreciated that the plug assembly  204  may remain within a patient to close a vascular puncture. For example,  FIG. 19  shows plug assembly  204  anchored proximate to wall  234  of blood vessel  290  and positioned at least partially within percutaneous incision  219  (i.e., surrounded by percutaneous tissue  220 ) to effectively close puncture  218 . As shown in  FIG. 19 , sealing plug  240  may be expanded against the surrounding percutaneous tissue  220  and substantially centered with respect to the original lumen puncture  218 . 
     The embodiments shown in  FIGS. 20-21D  and  22 - 23 B illustrate similar deployment of the sealing plug  240  by actuating the sliding collar  280  with the tamper  217 . In each of these two embodiments, when the anchor  208  is deployed in a lumen or vessel, the sealing plug  240 , which is arranged about the anchor support  210 , is compressed by the sliding collar  280 . The sliding collar  280  may likewise be arranged around the anchor support  210 . The tamper  217  is forced distally, which advances the sliding collar  280  and compresses and causes radial expansion of the sealing plug  240 . The sealing plug  240  may only advance to the lip  213 , and further advancement of the sliding collar  280  may tend to cause only radial expansion of the sealing plug  240 . The sliding collar  280  may be advanced until it reaches the radial groove or coupling feature  226  of the anchor support  210 . The sliding collar  280  then contacts and locks in the coupling feature  226  and prevents retraction of the sealing plug  240 . The anchor support  210 , sealing plug  208 , sliding collar  280 , and the anchor  208  remain at the puncture side and seal the puncture. 
     While certain embodiments and details have been included herein for purposes of illustrating aspects of the invention, it will be apparent to those skilled in the art that various changes in the systems, apparatuses, and methods disclosed herein may be made without departing from the scope of the invention, which is defined by the appended claims. Moreover, features shown in certain embodiments are not exclusive to the embodiment shown. Any feature shown in any embodiment may be used in any combination with other features described herein.