Abstract:
This invention relates to apparatus and methods for use in sealing a vascular puncture site and to apparatus and methods for properly locating and deploying a sealing device. The locating apparatus comprises a lumen which extends from an opening in the distal region of the apparatus but located proximally of the sealing device, which lumen extends to another opening in the proximal region of the device. When the distal opening is in communication with blood in a blood vessel, blood flow through the lumen and out of the proximal opening signifies such location to the user. When the sealing device is withdrawn such that the sealing device is deployed such that it blocks the blood flow into the distal port, the user will know the location of the sealing device. In a preferred embodiment, the sealing device is then withdrawn proximally a predetermined distance to assure that no part of the sealing device extends into the blood vessel lumen. The sealing device is then detached from the delivery device.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to apparatus and methods for sealing or closing passages through tissue, and more particularly to devices for sealing punctures or other openings communicating with body lumens, such as blood vessels, and to apparatus and methods for delivering such devices.  
       BACKGROUND OF THE INVENTION  
       [0002]     Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient&#39;s skin and muscle tissue into the vascular system. A guide wire may then be passed through the needle lumen into the patient&#39;s blood vessel accessed by the needle. The needle may be removed, and an introducer sheath may be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to a dilator. A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introduction of various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.  
         [0003]     Upon completion of the procedure, the devices and introducer sheath may be removed, leaving a puncture site in the vessel wall. External pressure may be applied to the puncture site until clotting and wound sealing occur. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a physician&#39;s or nurse&#39;s time. It is also uncomfortable for the patient, and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.  
         [0004]     Various apparatus have been suggested for percutaneously sealing a vascular puncture by occluding the puncture site. For example, U.S. Pat. Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the use of a biodegradable plug that may be delivered through an introducer sheath into a puncture site. When deployed, the plug may seal the vessel and provide hemostasis. Such devices, however, may be difficult to position properly with respect to the vessel, which may be particularly significant since it is generally undesirable to expose the plug material, e.g., collagen, within the bloodstream, where it may float downstream and risk causing an embolism.  
         [0005]     Another technique has been suggested that involves percutaneously suturing the puncture site, such as that disclosed in U.S. Pat. No. 5,304,184, issued to Hathaway et al. Percutaneous suturing devices, however, may require significant skill by the user, and may be mechanically complex and expensive to manufacture.  
         [0006]     Staples and surgical clips have also been suggested for closing wounds or other openings in tissue. For example, U.S. Pat. Nos. 5,007,921 and 5,026,390, issued to Brown, disclose staples that may be used to close a wound or incision. In one embodiment, an “S” shaped staple is disclosed that includes barbs that may be engaged into tissue on either side of the wound. In another embodiment, a ring-shaped staple is disclosed that includes barbs that project from the ring. These staples, however, have a large cross-sectional profile and therefore may not be easy to deliver through a percutaneous site to close an opening in a vessel wall.  
         [0007]     In addition, skin seals have been proposed that may be threaded into an opening in skin. For example, U.S. Pat. No. 5,645,565, issued to Rudd et al., discloses a surgical plug that may be screwed into a puncture to seal the puncture. The surgical plug includes an enlarged cap and a threaded shaft that extends from the cap. During an endoscopic procedure, the plug may be threaded into an opening through skin until the cap engages the surface of the skin. The plug is intended to seal the opening communicating with a body cavity to prevent insufflation fluid from leaking from the cavity. Such plugs, however, may only be used at the surface of the skin, and may not be introduced through tissue, for example, to seal an opening in the wall of a-blood vessel or other subcutaneous region.  
         [0008]     Various methods and means for determining the location of the distal end of a closure device have been proposed, including “bleedback” methodology such as that disclosed in U.S. Pat. No. 4,738,658 issued to Magro et al. However, prior bleedback devices have been constructed such that blood flow out of the patient continues for a longer period of time during deployment of the sealing means than would be desirable. Thus, a need exists for a closure device with a bleedback locator feature which reduces the amount of time during which blood flows out of the patient during deployment of a sealing member.  
       SUMMARY OF INVENTION  
       [0009]     The present invention is directed to a device which is capable of both locating a punctured blood vessel and sealing the puncture in the vessel and to the method of using the device as well. This device makes use of a “bleed back” feature, but, unlike known bleed back devices, uses a shut-off feature to deploy a sealing element at the desired location. In a preferred embodiment, the device of the present invention comprises an elongate member having a lumen extending from a point in the distal region to a point in its proximal region. The lumen is connected at its proximal and distal regions to proximal and distal ports in the elongate member which create a conduit from the lumen to the outer surface of the elongate member. In this embodiment, the elongate member is also provided with a detachable sealing element which is attached to the elongate member distally of its distal port. The sealing element may be a bioabsorbable felt or other suitable material. The proximal and distal ports are spaced sufficiently far apart that the proximal port is outside the patient&#39;s body when the distal port is within the lumen of the punctured blood vessel.  
         [0010]     In an alternative embodiment, a groove in the outer wall of the elongate member or in the inner wall of a tubular member, such as an introducer sheath, which runs from the distal region of the elongate member to the proximal region thereof is provided proximal to the sealing element such that blood can flow through the groove when the distal end of the groove is in communication with the blood in a blood vessel.  
         [0011]     In use, the device of the present invention can be used to close a puncture wound such as that in a femoral artery after a catheterization procedure has been performed. Typically, the device of the present invention will be introduced through an introducer sheath used in the catheterization procedure. When so used, the device is passed through the introducer sheath until the sealing element of its distal end and the distal port or distal opening of a groove are within the lumen of the femoral artery. The user will know when this has occurred when blood emerges from the proximal port or proximal end of a groove since this will occur when the distal port or distal end of a groove reaches the lumen of a blood vessel such as the femoral artery. Once this occurs, the device is withdrawn a short distance until the sealing element is no longer within the lumen of the femoral artery.  
         [0012]     The user will know when the sealing element is no longer within the lumen of the femoral artery because the blood flow out of the proximal port or proximal end of a groove will cease or substantially diminish once the sealing element is outside of the lumen of the femoral artery and is substantially sealing the puncture wound. In this preferred embodiment, the sealing element is fabricated from an expandable material which then expands to assure an effective closure of the puncture wound.  
         [0013]     The foregoing description has been directed to sealing a puncture wound in the femoral artery, but it is to be understood that the device of the present invention can be used to locate the lumens of other blood vessels and to seal puncture wounds in them. With that understanding, we turn to a more detailed description of the invention. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  illustrates the device of the present invention with its distal portion in the lumen of a blood vessel.  
         [0015]      FIG. 2  illustrates the distal region of the device after its distal portion has been withdrawn from the lumen of the blood vessel.  
         [0016]      FIG. 3  illustrates the deployed sealing element after it has been detached from the elongate member.  
         [0017]      FIGS. 4 and 4 A illustrate plug assemblies which may be used according to the present invention.  
         [0018]      FIG. 5  illustrates the plug assembly in conjunction with a delivery system.  
         [0019]      FIG. 6  and  7  illustrate the manner in which elements of the delivery system are coupled to each other.  
         [0020]      FIG. 8  illustrates in greater detail a delivery system which can be used according to the present invention.  
         [0021]      FIGS. 9 through 13  sequentially illustrate the manner in which the locating device and plug assembly of the present invention may be used.  
         [0022]      FIG. 14  is a perspective view of the delivery system and plug assembly mounted on a handle. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]     As can be seen from  FIG. 1 , the combined locator-sealing device of the present invention comprises tubular elongated member  11 , sealing member  12 , and optimally, handle  13 . The device  10  is shown as it would be when initially installed with its distal region in the lumen of blood vessel. As shown, the device  10  has been introduced through introducer sheath  15  which may have been used in a previous catheterization procedure.  
         [0024]     The elongated member  11  of device  10  has an internal lumen (not shown) which communicates with proximal port  16  and with distal port  17 . The proximal port  16  is separated from distal port  17  sufficiently to permit proximal port  16  to be outside of the patient&#39;s body when distal port  17  is within the lumen of blood vessel  14 . Thus, as shown in  FIG. 1 , the proximal port  16  is proximal of the patient&#39;s skin  18  and device  10  extends through introducer sheath  15  which is located in puncture wound tract  19  and extends through puncture  20  in the wall of the vessel  14 .  
         [0025]     When the device  10  is positioned as shown in  FIG. 1 , blood will flow into port  17  and out of port  16 , thereby indicating that the distal region of device  10 , including sealing member  12 , is within the lumen of vessel  14 . Once it is thus established that distal port  17  and sealing member  12  are within the lumen of vessel  14 , the introducer sheath  15  is partially withdrawn as shown in  FIG. 2 . Device  10  is then withdrawn until, as shown in  FIG. 2 , sealing member  12  has been withdrawn until it substantially occludes the flow of blood out of vessel  14  through puncture  20 . It will be apparent that such occlusion has occurred when the blood flow out of proximal port  16  has been substantially diminished by reason of the occlusion of puncture  20  by sealing member  12 . Sealing member  12  is then detached from elongated member  11 , as shown in  FIG. 3 .  
         [0026]     Preferably, sealing member  12  will be substantially adjacent to puncture  20  when it is detached. However, the device  10  can be used successfully when sealing member  12  is detached proximally of puncture  20  within tract  19 .  
         [0027]     Referring now to  FIG. 3 , it can be seen that, after disengagement from elongated member  11 , sealing member  12  occludes blood flow from puncture  20 . In a preferred embodiment, the sealing member  12  will be fabricated from a material which expands upon contact with blood such as a felt made from polyglycolic acid and/or polylactic acid polymers or copolymers or other materials such as collagens. The sealing member  12  may also have one or more hemostasis, antibiotic or other therapeutic agents added to it.  
         [0028]     Alternatively, in other preferred embodiments, the sealing member will be made in such a manner that it will expand spontaneously or upon removal of a restraining force. In still other embodiments, the sealing member can be expandable mechanically, hydraulically or pneumatically. In all such embodiments, it is preferred that the sealing member be fabricated from a bioabsorbable material.  
         [0029]     In  FIG. 4 , a preferred plug construction is shown. Plug assembly  120  comprises proximal element  121  and distal element  122  which is connected to element  121  through any suitable connection  123 . In this embodiment, the connection between elements  121  and  122  is a threaded connection. Proximal element  121  has cavity  124  therein. The purpose of cavity  124  will be explained with regard to  FIG. 5 . The sealing element of this preferred embodiment is bioabsorbable felt  125 . This bioabsorbable felt may be fabricated from polymers of polyglycolic acid, polylactic acid or copolymers thereof.  
         [0030]     In  FIG. 4A , an alternate plug assembly which is provided with two bioabsorbable felt sealing means is illustrated. As shown in  FIG. 4A , the plug assembly  420  comprises a proximal portion  421  and a distal portion  422 . The plug assembly is provided with two bioabsorbable felt sealing means  425  and  426  which are mounted between proximal portion  421  and distal portion  422 . Spacers  427  and  428  are also provided. The additional bioabsorbable felt member increases the efficiency of the sealing function of the plug assembly. It will be readily apparent to those skilled in the art that other configurations of the plug and the sealing elements may be used.  
         [0031]     The detachable connections between the sealing member  12  and the elongate member  11  may be any of a wide variety of connections. A preferred connection is illustrated in  FIG. 5 . In  FIG. 5 , plug assembly  120  is shown in combination with tubing  126  and pusher  127  which has a proximal shaft  128  and a larger diameter distal region  129  which distal region has a proximal shoulder  130 . When it is desired to separate plug assembly  120  from the remainder of the apparatus, pusher  127  is pushed distally (downwardly in  FIG. 5 ) while restraining tubing  126  from movement to push the proximal portion  121  of plug assembly  120  past the outwardly flaring shoulder  130  and the distal region of tubing  126 . In this embodiment, tubing  126  is provided with one or more openings  131  in its distal region which communicate with blood flow lumen  132  which, as explained with regard to  FIGS. 1 and 2 , extends to an opening (not shown in  FIG. 5 ) in the proximal region of sheath  126 . Once plug assembly  120  has been detached from sheath  126 , pusher  127  is withdrawn from plug assembly  120  simply by pulling pusher  127  in the proximal direction.  
         [0032]      FIGS. 6 and 7  illustrate one manner in which pusher member  127  can be combined with tubing  126 . As shown in  FIG. 6 , tubing  126  is a plastic tube and pusher  127  comprises enlarged distal portion  129  and elongated shaft  128 . To assemble these elements, pusher  127  can be moved proximally (to the left as shown in  FIG. 6 ) while tubing  26  is held stationary. The result, as shown in  FIG. 7 , is that the distal portion of tubing  126  will be expanded by the proximal shoulder  130  on distal portion  129  of pusher  127  such that pusher  127  and tubing  126  are releasably attached to each other. For purposes of simplicity, opening  131  and lumen  132  are not shown in  FIGS. 6 and 7 .  
         [0033]     Accordingly, the structure of  FIG. 5  can be assembled by first inserting the distal end  129  of pusher  127  into cavity  124  in plug assembly  120 . The outside diameter of distal end  129  is preferably smaller than the inside diameter of the opening in the proximal end  122  of the plug. The tubing  126  is then passed down over shaft  128  into the plug assembly. The tubing  126  is then pushed over the distal portion  129  of the pusher such that the diameter of the tubing expands over the shoulder  130  and distal portion  129 . When this is done, the tubing is expanded such that it is larger in outside diameter than the opening in the proximal portion  121  of plug assembly  120 . This couples tubing  126  and pusher  127  to plug assembly  120 .  
         [0034]     To release the plug assembly  120  from tubing  126  and pusher  127 , shaft  128  is pushed towards the plug assembly  120  while restraining movement of the tubing  126 . The distal portion  129  of pusher  127  is thus pushed out of the expanded end of tubing  126 , allowing the tubing to recover to its original outside diameter and to pass through the opening in the proximal portion of  121  of plug assembly  120 . Distal portion  129  of pusher  127  is thereby caused to move until it comes into contact with the floor of cavity  124  thereby assisting in pushing the plug off the end of the tubing  126 .  
         [0035]      FIG. 8  illustrates additional elements in the delivery system of the present invention. As shown in  FIG. 8 , plug assembly  220  is releasably attached to detachment assembly  227  as described with regard to  FIGS. 5-8 . Thus, plug assembly  220  comprises proximal portion  221  and distal portion  222  with a sealing material such as a bioabsorbable felt  225  firmly held between them. Distal portion  222  is attached to proximal portion  221  through any suitable connection  223  such as a threaded connection. Detachment assembly  227  comprises detachment tubing  226  which its distal region flared over shoulder  230  and which is releasably attached to pusher element  229 .  
         [0036]     In this embodiment, detachment assembly  227  is loaded into delivery sheath  235 . Delivery sheath  235  is provided with one or more bleed back openings  231  in its distal region. Bleed back opening  231  communicate with lumen  232  through which blood entering openings  231  will flow and, in this embodiment, exit through the proximal end of delivery sheath  235 . As shown in  FIG. 14  and as further described with regard that Figures lumen  232  may communicate with a handle and outlet port. In addition, delivery sheath  235  may be provided with plug introducer  236  which is shown diagrammatically and which is adapted to slide over plug assembly  220  to capture and compress felt  225  to facilitate introduction of the plug assembly into a femoral sheath which will be described in other figures.  
         [0037]     As shown in  FIG. 9 , femoral, or introducer, sheath  331  having hub  332  and port  333  to which tubing/valve assembly  334  are attached is shown diagramatically as installed in a patient such that the distal end of femoral sheath  331  extends into the lumen  336  of blood vessel  337 . The proximal end of the femoral sheath having hub  332  extends proximally of the patient&#39;s skin  338 .  FIG. 10  illustrates, again diagramatically, the femoral sheath  331  with a delivery sheath  339  of the type described in  FIG. 8  together with its associated plug delivery assembly extending part of the way down the femoral sheath, but not yet in the lumen  336  of blood vessel  337 . The plug is shown diagramatically as element  340  and the delivery sheath as element  341 .  
         [0038]      FIG. 11  illustrates the advancement of plug  340  and delivery sheath  341  into blood vessel lumen  336 . As shown in  FIG. 11 , bioabsorbable felt  342  has been released from the plug introducer  236  shown in  FIG. 8  and extends radially outwardly from plug  340 . As also shown in this figure, the hub  343  of delivery sheath  341  has been advanced until it contacts the hub  332  of femoral sheath  331 . When so deployed, one or more bleed back holes  344  are exposed in lumen  336  and permit blood flow through the bleed back lumen in the delivery sheath which is shown as element  232  in  FIG. 8 .  FIG. 12  diagramatically illustrates withdrawal of the femoral sheath and plug assembly into the tissue tract such that the blood flow into the one or more holes  344  in the wall of the delivery sheath has been stopped thereby indicating that the plug assembly is substantially withdrawn from the lumen  336 .  
         [0039]     As illustrated in  FIG. 13 , the plug assembly is then further withdrawn a predetermined fixed amount to assure that no part of the plug assembly is any longer within the lumen  336  of blood vessel  337 .  
         [0040]     The use of the embodiment illustrated in  FIG. 8  is illustrated in  FIGS. 9-13 . As shown in  FIG. 9 , a femoral sheath  331  has been inserted for the purpose of facilitating a treatment of a patient such as an angioplasty. After the angioplasty or other procedure has been completed, the device of the present invention is used to seal the puncture in the wall of the blood vessel  337 .  FIG. 9  shows the femoral sheath  331  in place.  FIG. 10  shows the initial stage of advancing the delivery sheath  341  and plug  340  which are shown diagramatically and correspond to plug assembly  220  and delivery sheath  235  of  FIG. 8 , respectively.  
         [0041]      FIG. 11  shows delivery sheath  341  advanced out of the distal end of the femoral sheath such that one or more bleed black holes  344  are exposed to the blood flow in the lumen  336  of blood vessel  337 . As also shown, the bioabsorbable felt  341  (which corresponds to felt  225  of  FIG. 8 ) is no longer constrained by the plug introducer shown as element  235  in  FIG. 8  and is free to extend radially from plug  340 . At this stage of use, the user will know that the plug  340  is in the lumen  336  because the blood flow into one or more holes  344  and through the lumen shown as element  232  in  FIG. 8 , which blood flow can be observed at the proximal end of the delivery sheath will inform the user that the plug is in the lumen. In a preferred embodiment lumen  232  communicates with outlet tube  240  having port  241  mounted in handle  239  as described in more detail with regard to  FIG. 14 . The plug has a shoulder, shown as element  230  in  FIG. 8 , which facilitates locating the tip of the plug in the end of the delivery sheath. The proximal end of detachment tubing  226  is locked into the proximal end of the delivery sheath, thus holding the plug tight into the outer end of the delivery sheath. The delivery sheath is long enough such that when its proximal end  343  contacts the proximal end of the femoral sheath  332 , as shown in  FIG. 11 , the bleed back holes  344  are exposed to the blood flow in blood vessel lumen  336 .  
         [0042]     As shown in  FIG. 12 , the femoral sheath and plug assembly are then withdrawn until the bleed back blood flow stops. At this time, the plug and delivery sheath are at or proximal to the vessel wall  337 . The whole assembly is then further withdrawn a fixed amount as shown in  FIG. 13  to properly position the plug within the tissue tract proximal of the puncture in vessel wall  337 , at which time the plug  340  is detached as previously described. A filler material, sealing fluid or other additional closure substance may then be added proximally of plug  340 , if desired. A tether, such as a suture, may also be attached to the proximal portion of the plug to facilitate moving it or removing it from the patient&#39;s body after it has been detached.  
         [0043]     As shown in  FIG. 14 , in a preferred embodiment, delivery sheath  235  is mounted on handle  239  which is provided with outlet tube  240  which is provided with port  241 . Outlet tube  240  may be connected to a tubing (not shown) such as tubing/valve assembly  334  of  FIG. 9 . Thus, in such an embodiment, the blood flow through lumen  232  will be visible when it exits through port  241 . Handle  239  is also provided with male fitting  237  which may be provided with threads in its distal region such that it can be brought into threaded engagement with the threads at the proximal portion  243  of plug introducer  236 . Outlet tube  240  is located in slot  242  in handle  239  such that once bleed back flow stops when the femoral sheath and plug assembly are withdrawn to the point shown in  FIG. 12 , the slot defines the fixed amount to which the whole assembly comprising the femoral sheath delivery sheath and plug are further withdrawn prior to detachment of the plug as shown in  FIG. 13 .  
         [0044]     The present invention is not to be considered to be limited to the specific embodiments set forth, but is of the full scope of the appended claims.