Patent Document

RELATED APPLICATION 
   This patent application is a continuation-in-part of pending U.S. patent application Ser. No. 10/687,848 filed on Oct. 17, 2003, the disclosure of which is incorporated by reference herein. 

   FIELD OF THE INVENTION 
   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 
   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. 
   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. 
   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. 
   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. 
   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. 
   U.S. Pat. No. 6,033,427, issued to Lee, discloses a method and device for sealing internal puncture sites which, in one embodiment, uses a dual lumen bleed back system in which the distal bleed back ports are axially spaced from each other such that when the obturator is in a certain location, there will be bleed back through one of the lumens, but not through the other. 
   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. 
   Various methods and means for determining the location of the distal end of a closure device have been proposed, including “bleed back” methodology such as that disclosed in U.S. Pat. No. 4,738,658 issued to Magro et al. However, prior bleed back 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. 
   A further development in bleed back technology is disclosed in published U.S. patent application 2004/0019330, in which a control element having an enlarged distal end is used both to control blood flow through the blood vessel puncture and to provide an indication of the position of the distal end of an introducer sheath by withdrawing the enlarged distal end from the lumen of the blood vessel into the puncture in the wall of the blood vessel such that bleed back is, according to this published application, stopped. 
   Leschinsky Patent No. 5,871,501 discloses the use of an anchor on a guide wire to provide an indication of the location of the wall of a blood vessel to assist in the placement of a hemostatic material to block flow of blood out of a puncture in the vessel. 
   Although these and other methods and devices have been proposed for deploying a plug to prevent blood flow from a puncture in a blood vessel, a need remains for a safe and effective device and method for deploying a plug for this purpose. 
   SUMMARY OF INVENTION 
   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. The device makes use of a “bleed back” feature which uses a shut-off feature to indicate the location of a sealing element at an approximate desired location. A guidewire-based system is then used to more precisely locate the sealing element. In a preferred embodiment, the device comprises a delivery tube in the form of an elongate member having a lumen extending from a point in its 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 retained within the elongate member distally of its distal port. The sealing element may be a bioabsorbable felt, a hydrogel, or other material suitable for the purpose of sealing punctures or other openings communicating with body lumens, such as blood vessels. The proximal and distal ports are spaced sufficiently far apart that the proximal port may be outside the patient&#39;s body when the distal port is within the lumen of the punctured blood vessel. 
   The device is also provided with an obturator in the lumen of the elongate member, which obturator has a relatively large diameter distal portion coupled to a shaft having a narrower diameter. The distal port in the elongate member is located proximally of the large diameter portion of the obturator. In this preferred embodiment, the distal portion of the obturator and the shaft have a common central lumen and an outer surface of the distal portion of the obturator is provided with a groove which is substantially parallel to the axis of the obturator. The device is also provided with a guidewire which passes through the groove on the external surface of the distal portion of the obturator and a tether which passes through the central lumen of the obturator. The guidewire has a specialized configuration at its distal end and is provided with an indicator means at its proximal region. These features facilitate the ability of the device to deploy the sealing element at a substantially precise location. Once this location is reached, the elongate member is withdrawn a short distance and the obturator is held stationary to eject the sealing element from the elongate member. 
   The tether, which passes through the central lumen of the obturator, is attached or coupled to the sealing element in any suitable manner, e.g., by wrapping, looping and/or tying the distal region of the tether around or to the sealing element. 
   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 provided with a flange or other means adapted to engage the device and to prevent further distal movement and which preferably is used in the catheterization procedure. When so used, the device is passed through the introducer sheath until the sealing element at the distal end of the obturator and the distal port in the elongate member are within the lumen of the femoral artery. The user will know when this has occurred when the engaging means on the introducer sheath arrests further distal movement by the device. When this occurs, blood will emerge from the proximal port because when the distal port reaches the lumen of a blood vessel, such as the femoral artery, blood will flow from the blood vessel, through the distal port, into and through the lumen in the elongate member and out of the proximal port. 
   Next, the device and sheath are withdrawn together a short distance such that the distal port is no longer within the lumen of the femoral artery and the flow of blood is substantially blocked from reaching the distal port by the patient&#39;s tissue and the sealing element. 
   The user will know when the sealing element is close to the desired position once it causes the blood flow out of the proximal port to cease or substantially diminish. At this point, the sealing element is at approximately the desired location. The device is then withdrawn until a disc attached to the proximal portion of the delivery tube comes into contact with a disc attached to the proximal portion of the guidewire, at which point the sealing element is in the final deployment position. 
   The disc attached to the guidewire and the disc attached to the delivery tube are spaced a short distance apart and permit a more precise positioning of the sealing element than would otherwise be possible. It is to be noted, however, that the use of such discs is preferred, but that other structures can be used to accomplish the same purpose. 
   The guidewire is then withdrawn into the guidewire tube in the groove in the obturator while holding the remainder of the device in place. At this time, the sealing instrument is at the desired location and can be deployed by withdrawing the elongate member a short distance, while holding the obturator in place, as described above. After deployment, the distal end of the obturator will be substantially at the distal end of the elongate member. The distal end of the guidewire will be in the lumen of the guidewire tube and the elongate member, obturator and guidewire may then be withdrawn from the patient as a unit. The tether will remain coupled to the sealing element and can be used to retrieve the sealing element should it become dislodged from the tract in the tissue leading to the puncture in the blood vessel. 
   If the device of the present invention is delivered through an introducer sheath, it is preferred to provide a coupling device such that the sheath and the device will become attached to each other when the distal port of the elongate member is within the lumen of the blood vessel. If this is done, the withdrawal of the device and the sheath as a unit will be facilitated as will the maintenance of the distal port at a location distal to the distal end of the sheath. 
   In the preferred embodiment, the sealing element is fabricated from an expandable material such as a felt made from strands of polyglycolic acid (PGA) which, because of its felt structure, then expands to assure an effective closure of the puncture wound. Alternatively, the sealing element may be fabricated from a hydrogel, such as hydroxypropyl cellulose (HPC) microporous hydrogel The seal may also be coated with or otherwise provided with a hemostatic material which will promote clotting. 
   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 
       FIG. 1  is a schematic illustration of the device of the present invention. 
       FIG. 2  is a cross-sectional view of the device illustrated in  FIG. 1 , taken on line A-A. 
       FIG. 3  illustrates the device of the present invention having its distal end inserted into the lumen of a blood vessel. 
       FIG. 4  shows the device of the present invention when it has been substantially withdrawn from the lumen of a blood vessel. 
       FIG. 5  shows the device of the present invention when the seal has been properly positioned. 
       FIG. 6  shows the device of the present invention after the seal has been ejected into the tissue tract. 
       FIG. 7  illustrates the tether feature of the device shown in  FIG. 1 . 
       FIG. 8  illustrates the device of the present invention with more detail at its proximal end. 
       FIG. 9  illustrates further detail of the proximal end of the device. 
       FIG. 10  illustrates a slot in the handle of the device. 
       FIG. 11  illustrates an exploded perspective view of the device of the present invention. 
       FIGS. 12A and 12B  illustrate portions of the device shown in  FIG. 11 , with additional detail at its proximal end. 
       FIG. 12C  illustrates further detail of components of a precise positioning feature. 
       FIG. 12D  illustrates a cross-sectional view of the device illustrated in  FIG. 12A , taken on line D-D. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates in a somewhat schematic form many of the features of the device of the present invention. The device  10  includes a delivery tube  11  which is provided with a distal port  12  and a proximal port  13 . An obturator  14  is housed within the delivery tube  11  and comprises a shaft  20  and a larger diameter distal portion  21 . The device  10  is also provided with a guidewire  15  which has a transversely extending distal portion  16 . The device is also provided with a sealing element  17  which is preferably formed from a felt, hydrogel, or other material suitable for use in sealing punctures or other openings communicating with body lumens, such as blood vessels. 
     FIG. 2  is a cross-sectional view of the device shown in  FIG. 1  taken on line A-A. As can be seen from  FIG. 2 , the distal portion  21  of the obturator  14  is provided with a groove  18  which serves as a passageway for the guidewire  15 . In addition, the obturator  14  is provided with a lumen  19  (not shown in  FIG. 1 ) which extends from its distal end to its proximal end and which serves as a passageway for a tether (also not shown). 
     FIG. 3  illustrates the device  10  having its distal portion inserted into the lumen  22  of a blood vessel  23 . As can be seen, the device extends through a tract  24  which extends through the tissue from the skin  25  of the patient to a puncture  26  in the wall of the blood vessel. When so positioned, the bleed back feature of the device, which comprises the distal port  12  in the delivery tube  11 , the lumen  27  of the delivery tube  11 , and the proximal port  13  of the delivery tube  11 , functions to indicate to the user that the distal portion of the delivery tube  11  is located in the blood vessel lumen by reason of the visible flow of blood out of the proximal port  13 . 
     FIG. 4  illustrates the device  10  after its distal portion including the distal port  12  has been withdrawn from the interior of the lumen  22  of the vessel  23 . When the device is in the position illustrated in  FIG. 4 , the tissue of the patient and the sealing material  17  have substantially diminished or prevented blood flow from reaching the distal port  12  and the proximal port  13 . Accordingly, the user will know from the substantial absence of blood flowing from the port  13  that the sealing material  17  is in approximately the appropriate location for deployment. However, before the sealing material  17  is deployed, additional positioning steps are preferably taken. 
   Referring to  FIG. 4 , it can be seen that the transversely extending distal portion  16  of the guide wire is not in contact with the vessel wall at this stage of withdrawal of the device  10 . 
   Referring next to  FIG. 5 , it can be seen that the distal portion  16  of the guidewire has been brought into contact with the vessel wall  23  and that, in addition, the distal portion  16  of the guidewire has been reconfigured by reason of the pressure exerted by the wall on that distal portion  16 . This contact between the distal portion of the guide wire and the vessel wall can be felt by the user because of the resistance to further proximal movement of the guidewire  15 . This contact may also be confirmed by viewing the deformation of the distal portion  16  of the guidewire by suitable means, such as by fluoroscopy. This occurrence may be used to achieve final positioning of the device for deployment of the sealing element  17 , as described more fully below. 
   As shown in  FIG. 6 , the sealing material  17  is deployed by withdrawing the delivery tube  11  proximally while at the same time holding the obturator  14  stationary. This causes the sealing element  17  to be ejected from the tube  11  and to take its desired position in the vessel tract  24  proximal to the puncture  26 . The guide wire  15  is also withdrawn proximally such that its distal portion  16  passes through the groove  18  and resides in the lumen  27  of the delivery tube  11 , or, preferably, in a guidewire tube  34  extending through the length of the lumen  27  (see  FIG. 8 ). Preferably, the distal end of the tube  11  will be flush with the distal end of enlarged portion  21  of the obturator  14 . The entire device  10  may then be removed from the patient by withdrawing it from the tract  24 . Preferably, a tether (not shown) which extends through the central lumen  19  of the obturator  14  is provided and is tied or otherwise suitably attached to the sealing element  17 . The tether serves to give the user at least a measure of control over the sealing element  17  in the event that there is any need to withdraw the sealing element  17  from the patient. This may be done simply by pulling proximally on the tether until the sealing element  17  is removed. 
   The relationship between the tether  28  which has its distal portion looped around the sealing element  17  is shown diagrammatically in  FIG. 7 , which also shows the distal portion  21  and the shaft  20  of the obturator  14  having the central lumen  19  extending therethrough. As noted above, the tether  28  may be secured to the sealing element  17  by tying, looping, or any other suitable means. The representation shown in  FIG. 7  is for illustrative purposes. 
   Referring now to  FIG. 8 , the device of the present invention is illustrated in somewhat more detail with regard to its proximal structure.  FIG. 8  shows the delivery tube  11  which is provided with the distal port  12  and proximal port  13  and which houses the shaft  20  and the distal portion  21  of the obturator in its lumen  27 . The delivery tube  11  is also provided with a guidewire tube  34  which serves as a passage for the guidewire from the proximal end of the device through the groove  18  in the distal portion  21  of the obturator. The sealing element  17  is also shown. 
   The actuator  31 , which is bonded or otherwise suitably attached to the delivery tube  11 , is also shown. The actuator  31  is provided with a knob  32  that has a lumen  33  which is aligned with the proximal port  13  in the delivery tube  11 . The knob  32  can be used to move the delivery tube  11  proximally and distally. In use, the actuator  31  is moved proximally while holding the obturator  14  stationary such that the sealing element  17  is ejected from the delivery tube  11  once the delivery tube has been properly located. A cap  35  is provided with an aperture through which the shaft  20  of the obturator  14  can slide. A length of necked tubing  51  is provided surrounding the shaft  20  to provide a slidable seal. The cap  35  is also provided with an aperture for the guide wire tube  34 , but the guide wire tube  34  is bonded or otherwise suitably attached to the cap  35  such that movement of the actuator  31  will cause the delivery tube  11  and the guide wire tube  34  to move as a unit. Adhesive material  52  is provided near the proximal end of the delivery tube  11  to maintain the relative positions and seal the necked tubing  51  and guidewire tube  34  relative to the delivery tube  11 . 
   The actuator  31  is also provided with a recess  36  which is preferably annular in configuration. The recess  36  terminates at a floor  37  which, as explained in more detail with regard to other drawings, functions as a seat for a spring. 
     FIG. 9  further illustrates the proximal region of the device and, in addition to the elements shown in  FIG. 8 , shows a button  38  in the recess  36  with a spring  38  biasing the button  36  in a proximal direction. The proximal end of the button  38  is provided with a tube  39  through which the guidewire tube  34  can slide. Also shown is a handle  40  which surrounds the actuator  31  and the button  38 . The handle  40  is provided with an L-shaped slot  41 , which is more completely illustrated in  FIG. 10 , in which the knob  32  is able to move. This L-shaped slot is partially shown as element  41  in  FIG. 9 . The proximal portion of the guidewire tube  34 , which is fixed to the actuator  31 , is provided with an actuator disc  42 . Proximal to the actuator disc  42  is a guidewire disc  43  which is attached to the guidewire  15 . The actuator disc  42  and the guidewire disc  43  are separated by a spring  45 . 
   The L-shaped slot  41  in the handle  40  is shown in more detail in  FIG. 10 . As can be seen from that Figure, the knob  32  can move both transverse to the longitudinal axis of the device in the shorter leg of the slot and in an axial direction in the longer leg of the slot. 
     FIG. 11  is an exploded perspective view of an embodiment of the device of the present invention. As here illustrated; it can be seen that handle  40  is comprised of an upper half  46  and a lower half  47 . The handle upper half  46  contains the L-shaped slot  41 . The actuator  31  having the knob  32  and the button  38  are also shown, with the knob  32  being received and retained in the L-shaped slot  41 . The delivery tube  11  with the distal port  12  together with the distal portion of the guidewire  44  comprise the distal portion of the device. The delivery tube  11  is provided with a collar  48  which extends into the distal recess  49  in the handle  40  when the upper and lower handle halves  46  and  47  are joined together. The actuator disc  42  is attached to the guidewire tube  34  near its proximal end, while the guidewire disc  43  is attached to the guidewire at a point proximal to the actuator disc. 
   Turning to  FIGS. 12A-D , additional detail is shown relating to the actuator  31  and the actuator disc  42  and guidewire disc  43 . In  FIG. 12A-B , the actuator  31  is shown, having the knob  32  located at a distal portion and the button  38  at its proximal end. The actuator  31  comprises two parts, a proximal portion  31   a  and a distal portion  31   b  (see  FIG. 12B ). The proximal portion  31   a  of the actuator forms an internal shoulder  31   c  that limits proximal movement of the button  38 . The spring  44  ( FIG. 12B ) biases the button in the proximal direction. The guidewire tube  34  extends proximally from the actuator  31 , with the guidewire  15  located inside the lumen of the guidewire tube  34 . The actuator disc  42  is attached to the proximal end of the guidewire tube  34 , and the guidewire disc  43  is attached to the guidewire  14  at a point proximal to the actuator disc  42 . 
   Referring to  FIG. 12C , a disc spring  45  is provided between the actuator disc  42  and the guidewire disc  43 . The disc spring  45  provides a force that tends to separate the two discs  42 ,  43 , i.e., the disc spring  45  biases the actuator disc  42  distally and biases the guidewire disc  43  proximally, relative to one another. 
     FIG. 12D  provides additional detail relating to the proximal portion of the device. As shown, the button  38  has a lumen  53  that is used to inject the adhesive material  52  described above in relation to  FIG. 9 . The obturator shaft  20  is attached to the button  38 , as is the tube  39  through which the guidewire tube  34  and guidewire  15  are able to slide. The proximal portion of the actuator  31   a  is shown, and is described more fully above. 
   Additional detail concerning the operation of the actuator disc  42  and guidewire disc  43  will now be described. The actuator disc  42  and guidewire disc  43  are used to provide final, precise positioning of the sealing element  17  in the tract  24  formed in the tissue of the patient. As described previously, the guidewire disc  43  is attached to a proximal portion of the guidewire  14 , whereas the actuator disc  42  is attached to the guidewire tube  34 , which is, in turn, attached to the actuator  31 . The two discs  42 ,  43  are separated by a small distance,  1 , as shown in  FIG. 12C . When the device  10  is being withdrawn from the lumen of the vessel, as described above, the distal portion  16  of the guidewire engages the vessel wall  23  at the point during withdrawal that the distal end of the device  10  is withdrawn from the vessel, as shown, for example, in  FIG. 5 . At this point, the bleedback feature will be in a condition that no substantial bleedback is taking place, indicating that the device is near the location at which the sealing element  17  is to be deployed. Continued withdrawal of the device will cause the guidewire  15  to remain relatively stationary, due to the engagement of the guidewire distal portion  16  with the vessel wall. At the same time, the actuator  31 , the actuator disc  43 , and the remaining portions of the device  10  will continue to move proximally. The final deployment position is indicated when the actuator disc  43  engages the guidewire disc  42 , i.e., when the device has been withdrawn an additional distance— 1 —from the point at which the guidewire distal portion  16  engages the vessel wall. At this point, the sealing element  17  is deployed. 
   As described above, deployment of the sealing element is achieved by causing proximal movement of the delivery tube  11  relative to the obturator  14 . This is achieved by sliding the knob  32  axially in the L-shaped slot  41 . Because the knob  32  is coupled with the actuator  31 , this axial movement causes the actuator  31  and the delivery tube  11  to advance proximally. At the same time, the obturator  14  is held in place, thereby deploying the sealing element  17  in the selected location. The actuator  31  is able to move proximally within the handle  40  against the spring force of the button spring  44 , as the proximal end of the button  38  engages an internal surface of the handle  40 . In this way, the delivery tube  11 , which is attached to the actuator  31 , is able to move axially relative to the actuator  14 . 
   While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims.

Technology Category: 1