Abstract:
Self-tensioning occlusion devices and systems provide percutaneous access and closure of vascular puncture sites. One device includes a catheter body having a proximal end and a distal end, an occlusion member, and a tensioning member. The occlusion member, for example an expansible member, is disposed on a distal end of the body. The tensioning member, such as a spring or coil, is slidably disposed over the body and proximal to the expansion member. Generally, during application, the tensioning member will be positionable against subcutaneous tissue so as to lodge and anchor the expansible member against the puncture site. In particular, the expansible member allows for sealing of the puncture site while the tensioning member applies and maintains tension to the expansible occluder so that it is seated against the puncture site at a vascular surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 10/857,177 filed on May 27, 2004, the full disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to devices, systems, and methods for percutaneous sealing of puncture sites in body lumens or tissue tracts. More specifically, the present invention relates to self-tensioning vascular occlusion devices, systems, and methods for its use for hemostasis of vascular puncture sites. 
     Percutaneous access of blood vessels in the human body is routinely performed for diagnostics or interventional procedures such as coronary and peripheral angiography, angioplasty, atherectomies, placement of vascular stents, coronary retroperfusion and retroinfusion, cerebral angiograms, treatment of strokes, cerebral aneurysms, and the like. Patients undergoing these procedures are often treated with anti-coagulants such as heparin, thrombolytics, and the like, which make the closure and hemostasis process of the puncture site in the vessel wall at the completion of such interventional procedures more difficult to achieve. 
     Various devices have been introduced to provide hemostasis, however none have been entirely successful. Some devices utilize collagen or other biological plugs to seal the puncture site. Alternatively, sutures and/or staples have also been applied to close the puncture site. External foreign objects such as plugs, sutures, or staples however may cause tissue reaction, inflammation, and/or infection as they all “leave something behind” to achieve hemostasis. 
     There is also another class of devices that use the body&#39;s own natural mechanism to achieve hemostasis wherein no foreign objects are left behind. Such devices typically provide hemostasis by sealing the puncture site from the inside of the vessel wall wherein the device is left in place in the vessel lumen until hemostasis is reached and thereafter removed. These devices generally comprises two separate and distinct components, namely a catheter and an external tensioning element. The external tensioning element is typically connected to the catheter shaft and rests on an exterior surface of the skin after the catheter is positioned in the vessel. It provides tension to the catheter at the puncture site as well as anchors the applied tension so that a tip of the deployed catheter is maintained against the vessel wall at the puncture site. The external tensioning element is kept in tension for a period of time. 
     Although such devices have achieved relative levels of success, the external tensioning element is not always easy and convenient in its application. Further, the external tensioning element may not always preserve the integrity of the catheter system. For example, manipulation of the catheter when the external tensioner is applied or removed may cause disruption of the seal at the vessel puncture site, resulting in bleeding or hematoma formation (i.e., leaking of blood into interstitial space). Also, the external tensioner may be subject to being dislodged accidentally while in use, which may result in complications, such as resumption of bleeding. 
     In light of the above, it would be desirable to provide alternative devices, systems, and methods for complete hemostasis of a puncture site in a body lumen, particularly blood vessels of the human body. It would be particularly desirable if such devices, systems, and methods utilize the body&#39;s own natural healing mechanism to achieve hemostasis. It would be further desirable if such devices and systems utilize a simple construction and user interface allowing for convenient application without numerous intermediary steps. Further, such devices should be reliable, preserve the integrity of the system, and provide for appropriate tension application without the need for user intervention. At least some of the these objective will be met by the devices, systems, and methods of the present invention described hereinafter. 
     2. Description of the Background Art 
     Hemostasis devices for use in blood vessels and tracts in the body are described in co-pending U.S. patent application Ser. Nos. 10/821,633 and 10/718,504 and U.S. Pat. Nos. 6,656,207; 6,464,712; 6,056,770; 6,056,769; 5,922,009; and 5,782,860, assigned to the assignee of the present application. The following U.S. patents and Publications may be relevant to the present invention: U.S. Pat. Nos. 4,744,364; 4,852,568; 4,890,612; 5,108,421; 5,171,259; 5,258,000; 5,383,896; 5,419,765; 5,454,833; 5,626,601; 5,630,833; 5,634,936; 5,728,134; 5,836,913; 5,861,003; 5,868,778; 5,951,583; 5,957,952; 6,017,359; 6,048,358; 6,296,657; U.S. Publication Nos. 2002/0133123; 2003/0055454; and 2003/0120291. 
     The full disclosures of each of the above mentioned references are incorporated herein by reference. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention advantageously provides self-tensioning occlusion devices, systems, and methods for percutaneous access and closure of puncture sites in a body lumen, particularly blood vessels of the human body. It will be appreciated however that application of the present invention is not limited to the blood vasculature, and as such may be applied to any of the vessels, even severely tortuous vessels, ducts, and cavities found in the body as well as tissue tracts. Such closure devices, systems, and methods utilize the body&#39;s own natural healing mechanism to achieve complete hemostasis without leaving any foreign objects behind. 
     In a first aspect of the present invention, a device for hemostasis of a puncture site in a body lumen or tissue tract comprises a catheter body having a proximal end and a distal end, an occlusion member, and a tensioning member. The occlusion member, such as an expansible member, is disposed on a distal end of the body. The tensioning member is slidably disposed over the body and proximal the expansion member. Generally, during application, the tensioning member will be positionable against subcutaneous tissue so as to lodge and anchor the expansible member against the puncture site. In particular, the expansible member allows for sealing of the puncture site while the tensioning member applies and maintains tension to the expansible occluder so that it is seated against the puncture site at a vascular surface (e.g., blood vessel wall). 
     The present invention integrates the expansible occluder with the tensioning member to form a single unitary catheter construction. This simple construction and user interface allows for easy and convenient application of the device without numerous intermediary steps. Further, the tensioning member is not subject to interference due to catheter integration. This results in a more reliable, safe, and effective device which preserves the integrity of the system, which in turn reduces the risk of bleeding, hematoma formation, thrombosis, embolization, and/or infection, particularly in lengthy applications. 
     The tensioning member typically comprises a spring or coil of wire formed from a variety of medical grade materials including stainless steel, shape memory alloy, superelastic metal, and the like. The wire may have a diameter in a range from about 0.02 mm to about 1 mm and form any number of loops, typically from 1 to 30 loops. The spring or coil diameter will be in a range from about 1 mm to about 10 mm in a relaxed state. As discussed in more detail below, the relaxed spring diameter is sufficiently large to allow it to be slidably received over the catheter body and greater than an inner diameter of a delivery sheath. A tubular member may additionally be slidably disposed over the catheter body and coupleable to a proximal end of the tensioning member. Such a tubular member may aid in loading and removal of the tensioning element as well as provide a mechanism for applying a predetermined amount or additional tension upon the expansible member. 
     The expansible member may comprise a variety of structures including a braided filament, mesh layer, spring, coil, slotted tube, or balloon. Generally, a deformable membrane will at least be partially disposed over the expansible member. However, in the case where the expansible member comprises a braided mesh, the braid may be sufficiently tight without the use of a membrane so that in a deployed state it can adequately occlude the puncture site in the vessel. The expansible member may also be coated with a highly hydrophobic coating such as TEFLON® or HYDRO-SIL®. The combination of small pores in the braided mesh and high surface tension of the expansible member achieved by the use of such coatings may provide adequate barrier to blood flow through the puncture site. Exemplary expansible member structures are described in detail in co-pending U.S. patent application Ser. No. 10/718,504, assigned to the assignee of the present application and incorporated herein by reference. The expansible member occludes the vascular surface at the puncture site without substantially disturbing the blood flow to the lower extremities. In some embodiments, the deformable membrane may further comprise a membrane tip at the most distal end of the catheter body so as to provide a soft and blunt point for percutaneous access. In other embodiments, a flexible tip deflector may be coupleable to the catheter body distal the expansible member so as to prevent any damage to the surrounding vessel wall. 
     The device of the present invention further comprises deployment means, such as a two part handle assembly, coupleable to the proximal end of the catheter body. A locking or latching mechanism may be incorporated into the two part handle so as to securely and reliably lock the expansible member in an expanded configuration. Further, such a locking or latching mechanism may also be incorporated into the tubular member of the tensioning element so as to provide a connection to the deployment means for easy loading into the sheath and removal of the tensioning element and the catheter from the body. 
     In another aspect of the present invention, methods to use the device for hemostasis of a puncture site in a blood vessel at an end of a tissue tract are provided. A catheter having a proximal end, a distal end, an expansible member at the distal end thereof, and a tensioning member proximal the expansible member is provided. The catheter is inserted through an opening in a skin surface, typically through a seal of an existing sheath, so as to traverse a length of the sheath and expose the expansible member of the catheter in a lumen of the blood vessel. The expansible member of the catheter is then deployed in the blood vessel. The sheath is then slowly pulled out of the body, placing the expansible member of the catheter against the inner wall of the vessel at the puncture site. As the sheath is further removed, the tensioning member of the catheter which is slidably located on the catheter shaft is released from the sheath and into the fascia surrounding the tissue track. The tensioning member is lodged against the fascia, providing for adequate tension on the expansible member to seal the puncture site. 
     Hence, the expansible occluder of the device may be set by the removal of the sheath, therefore simplifying the procedure. Further, the tensioner may be set by the removal of the sheath so as to provide for appropriate tension application. This may be achieved by the interference between the sheath and the tensioning coil as a result of the coil diameter, in a relaxed state, being larger than the sheath diameter. In other embodiments, the device may be equipped with a loading element, a flexible elongated tube that contains the tensioning element and can be slidably received within the sheath. In such an embodiment, the tension is set by the interference between the tensioning coil and the loader as the sheath and the loader are removed. When a loader is used, the tension produced and exerted on the expansible member remains the same. The use of the loader or the sheath to set the tension advantageously eliminates user involvement in setting the tension, and consequently provides for more precise and consistent application of tension. As such, the devices of the present invention do not require measurements, such as length measurements for the placement of the expansible member or force measurements for application of tension. Further, removal of the catheter is simplified, as there is no external tensioner to be removed. Generally, the integrated design of the present invention greatly simplifies and automates operation of the device without any intermediary steps between its application and removal. 
     Typically, the amount of tension applied to the expansible member is in a range from about 0.5 ounce to 30 ounces, preferably in a range from about 5 ounces to 15 ounces. The expansible member is further anchored against the puncture site. This is typically carried out by the tensioning member. However, in some embodiments, an external clip seated against the skin surface may be utilized to anchor and/or provide additional tension upon the expansible member. Still further, tension on the expansible member may be increased by pulling on the tubular member coupled to the tensioning spring in a proximal direction. It will be appreciated that a predetermined amount of tension may be applied to the expansible member. For example, the tubular member coupled to the tensioning spring may be displaced a predetermined distance to effect a predetermined transitional tension onto the expansible member. 
     Deployment of the expansible member typically comprises pushing or pulling a two part handle assembly coupled to the expansible member. The parts of the handle assembly are locked by conventional mechanical means, so that the expansible member securely remains in a deployed configuration. Methods of the present invention may further comprise interlocking the handle assembly with the tubular member coupled to the tensioning spring. As discussed above, this connection provides for easy loading and removal of the tensioning element and/or for re-introducing the sheath over the catheter if necessary. Generally, the expansible member is deployed to an expanded configuration within the blood vessel having a diameter in a range from about 3 mm to about 10 mm. 
     The expansible member and tensioning member are deployed sequentially or simultaneously. Deployment of the tensioning member may comprise of removing an elongated tubular member, such as a delivery sheath or loading element, disposed over the tensioning member in a proximal direction. The loading element is preferably removed concurrently with the sheath. In particular, the diameter of the tensioning member in a relaxed state is greater than the inner diameter of the delivery member so as to provide adequate positioning and tension upon the expansible member. 
     The present invention further includes kits comprising a self-tensioning vascular occlusion device as described herein and instructions to use the device for hemostasis of a puncture site in a blood vessel. Instructions for use will generally recite the steps for performing one or more of the above described methods. The instructions will often be printed, optionally being at least in part disposed on packaging. The instructions may alternatively comprise a videotape, a CD-ROM or other machine readable code, a graphical representation, or the like showing any of the above described methods. The kit may further include additional components of the system, such as a loading element, sheath, external clip, or the like. The kit components will be packaged in a conventional medical device package that is usually sterile, such as a pouch, tray, box, or the like. 
     A further understanding of the nature and advantages of the present invention will become apparent by reference to the remaining portions of the specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings should be read with reference to the detailed description. Like numbers in different drawings refer to like elements. The drawings, which are not necessarily to scale, illustratively depict embodiments of the present invention and are not intended to limit the scope of the invention. 
         FIG. 1  illustrates an exemplary self-tensioning vascular occlusion device for hemostasis of vascular puncture sites constructed in accordance with the principles of the present invention. 
         FIG. 2  illustrates an alternative embodiment of the occlusion membrane that may be employed in any of the devices disclosed herein. 
         FIGS. 3A and 3B  illustrate another embodiment of the expansible member in a retracted configuration and an expanded configuration respectively that may be employed in any of the devices disclosed herein. 
         FIGS. 4A and 4B  illustrate yet another embodiment of the expansible member in a retracted configuration and an expanded configuration respectively that may be employed in any of the devices disclosed herein. 
         FIGS. 5A through 5C  illustrate an alternative embodiment of the deployment means that may be employed in any of the device disclosed herein. 
         FIG. 6  illustrates a system for hemostasis of a puncture site in a body lumen employing the device of  FIG. 1  in conjunction with a loading element. 
         FIG. 7  illustrates another device for hemostasis of a puncture site in a body lumen employing a locking mechanism. 
         FIGS. 8A  though  8 D illustrate a method for hemostasis of a puncture site in a body lumen employing the device of  FIG. 1 . 
         FIGS. 9A through 9C  illustrate another embodiment of the expansible member in a retracted configuration, expanded configuration, and retraction through unwinding process, respectively that may be employed in any of the devices disclosed herein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1 , an exemplary self-tensioning vascular occlusion device  10  for hemostasis of vascular puncture sites constructed in accordance with the principles of the present invention is illustrated. Device  10  comprises a first flexible elongated tubular member  11  having a distal end  12  and a proximal end  13 . Tubular member  11  may be formed from coiled stainless steel tubing or polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Tubular member  11  may have a length in a range from about 10 cm to about 50 cm, preferably in the range from about 15 cm to about 30 cm and a diameter in the range from about 0.25 mm to about 5 mm, preferably in the range from about 0.5 mm to about 2 mm. An expansible occlusion member  14  is disposed on the distal end  12  of tubular member  11 . Further, a tensioning member  26  is slidably disposed over the tubular member  11  and proximal the expansible member  14 . It will be appreciated that the above depictions are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the device  10 . This applies to all depictions hereinafter. 
     Referring now to  FIG. 2 , the expansible member  14  may at least partially or preferably be fully covered with an elastomeric membrane material  36 . Membrane  36  may be formed from a variety of medical grade materials, such as thermoplastic elastomers (e.g., CHRONOPRENE® or POLYBLEND®) having durometers in a range from 15 Å to about 40 Å. Membrane  36  may be connected at a distal connection point  17  and a proximal connection point  15 . Adhesives such as LOCTITE® 4014 may be used to attach membrane  36  to the catheter  11 . Alternatively, membrane  36  may take a form of a sock having its distal end sealed through a heat stake process or the like. In this case membrane  36  may not have to be attached distally. Membrane  36  preferably has a diameter that is sufficient to cover the expansible member  14 . In some embodiments, membrane  36  may be designed and attached to facilitate expansible member  14  deployment as well as to reduce the amount of required elongation when the expansible member  14  is deployed. This may be achieved by molding the membrane  36  so that its midpoint diameter, where deployed expansible member  14  has its greatest diameter, is larger than its proximal and distal end diameters (e.g., a spherical shape). Membrane  36  may also be formed like a tube with a larger diameter than needed (diameter of retracted expansible member  14 ), and then stretched over expansible member  14  and attached. The stretch should be enough to reduce the diameter of the membrane  36  to that of the expansible member  14 . In such a case, when member  14  is deployed, there is less elongation and stress experienced by membrane  36 . The membrane  36  may additionally form a membrane tip  37  at a distal end  12 A of the catheter  11  so as to provide a soft and blunt point for percutaneous access. 
     Referring now to  FIGS. 3A ,  3 B,  4 A, and  4 B, expansible member  14  may be formed from a variety of medical grade materials, including stainless steel, superelastic material such as NITINOL®, or polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. The expansible member  14  in a retracted or collapsed state has a diameter of less than about 3 mm, preferably less than about 1.5 mm, as shown in  FIGS. 3A and 4A . When deployed, the expansible member  14  in an expanded state has a diameter in a range from about 3 mm to about 10 mm, preferably from about 4 mm to about 7 mm, as shown in  FIGS. 3B and 4B . The expansible member  14  may comprise a push or a pull type deployment means as is described in detail co-pending U.S. patent application Ser. No. 10/821,633, assigned to the assignee of the present application and incorporated herein by reference. Exemplary expansible member structures  14  are described in detail in co-pending U.S. patent application Ser. No. 10/718,504, assigned to the assignee of the present application and incorporated herein by reference. Still further embodiments of a braided mesh member  14  are disclosed in U.S. Pat. No. 5,836,913, also incorporated herein by reference. 
     In a preferred embodiment, the expansible member  14  comprises a pull type, where the retracted state of the expansible member  14  is its natural, unconstrained free state. Deployment of the expansible member  14  requires that a member  16  be pulled proximally, as denoted by arrow  9  in  FIGS. 3A and 4A .  FIG. 3A  illustrates a malecot member  14  in its natural retracted state and  FIG. 3B  shows this expansible member  14  in its expanded state at a distal end  12 B of the catheter  11 .  FIG. 4A  illustrates another embodiment that comprises a tubular braided mesh member  14  in its free retracted state at a distal end  12 C of the catheter.  FIG. 4B  illustrates this expansible member  14  in its deployed expanded configuration. The manner in which these expansible members  14  may be assembled onto the catheter  11  and the way in which these members  14  may interact with other components of the device  10  are similar. 
     Referring back to  FIG. 1 , a proximal end of expansible member  14  is connected to the distal end  12  of tubular member  11  at connection point  15 . The connection may be made with a crimp process, use of shrink tubing such as polyester tubing, adhesives such as glue, heat staking member  14  into member  11 , or a combination thereof. A distal end of expansible member  14  is connected to the push/pull member  16  at connection point  17 . Push/pull member  16  may be formed from metals (e.g., stainless steel or NITINOL®) or from polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Member  16  has a diameter small enough to go through the tubular member  11  and a length that is long enough to traverse the length of the tubular member  11 . The proximal end  13  of members  11  and  16  incorporate a handle assembly  18 . A first part of the handle  19  is connected to the proximal end  13  of member  11 . A second part of the handle  20  is connected to proximal end of member  16 . Handle parts  19  and  20  provide for an enhanced grip on members  11  and  16 , allowing the user to more conveniently move these members with respect to each other for the purpose of deploying and retracting the expansible member  14 . Moving parts  19  and  20  away from each other causes the deployment of expansible member  14  and moving them towards each other causes the retraction of expansible member  14 . 
     Referring now to  FIGS. 5A through 5C , if no friction is built into the movement of members  11  and  16 , handle assembly  18 A may be designed to allow the deployed state of expansible member  14  to be held in position. This is because the lack of friction allows members  11  and  16  to move freely with respect to each other forcing the expansible member  14  back to its natural retracted state. Hence, locking features  21  and  22  of handle parts  19  and  20  respectively may be locked to maintain the expansible member  14  in a deployed configuration. In operation, parts  19  and  20  are moved apart until features  21  and  22  completely slide over each other. Handle part  20  can then be twisted with respect to part  19  by approximately 180° degrees, allowing the proximal end  21  of handle part  19  to rest over the distal end  22  of handle part  20 , as shown in  FIG. 5B . These ends  21  and  22  may be serrated or one end may have a half circular protrusion, as in feature  23  on proximal end of part  19 , and the other end have a half circular indentation, such as feature  24  on the distal end of part  20 , allowing these ends to detent into each other. A top view of this locking mechanism is illustrated in  FIG. 5C  showing the handle assembly in a deployed position. This locking mechanism may be beneficial to greatly reduce the chances of parts  19  and  20  slipping relative to each other causing unintended retraction. To further secure and stabilize the handle assembly  18 A, particularly during deployment of expansible member  14 , a handle housing  35  may at least be partially disposed over parts  19  or  20 . In  FIG. 5A , housing member  35  is attached to the first part of the handle  19  and is long enough that when member  14  is deployed and features  23  and  24  are in contact, member  35  extends proximally beyond feature  22 . 
     Referring now to  FIGS. 1 ,  6 , and  7 , device  10  also includes a second flexible tubular member  25  that is slidably disposed over the first tubular member  11 . Second member  25  is formed from a variety of medical grade materials, including polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Second member  25  is shorter than first member  11  and may have a length in range from about 5 cm to about 40 cm, preferably in the range from about 10 cm to about 20 cm. A distal end of member  25  is connected to the tension coil spring  26 . Tension coil spring  26  encompasses first member  11 , wherein its distal end is connected to member  11  proximal the expansible member  14  at connection point  15 . 
     Tensioning member  26  may be formed from a variety of medical grade materials, including suitable metals such as stainless steel or preferably shape memory or superelastic metals such as NITINOL®. The amount of force that expansible member  14  can exert against a vessel wall at the puncture site primarily depends on the diameter of the wire used, the diameter of the resulting coil, the pitch of the coil, and/or the total number of the loops in the coil of the tensioning member  26 . The number of loops in the coil spring  26  may be in the range from about 1 loop to about 30 loops, preferably in the range from about 3 loops to about 20 loops. The coils are preferably wound tightly with little or no pitch between the loops when the coil  26  is at its relaxed state. The wire diameter used to fabricate the coil  26  may be in the range from about 0.02 mm to about 1 mm, preferably in the range from about 0.05 mm to about 0.5 mm. The fabricated coil  26  may have a diameter in the range from about 1 mm to about 10 mm, preferably in the range from about 1.5 mm to about 5 mm in a relaxed state. The diameter of the tension coil spring  26  in the preferred embodiment of this invention is chosen to be greater than the inside diameter of a delivery sheath. For example, when a 5 Fr sheath is used the diameter of coil  26  would be greater than 1.75 mm. The greater this difference, the greater the interference between the coil spring  26  and the sheath, and consequently the greater is the resulting tension on the expansible member  14  against the vessel wall as the sheath is being removed. The operation of device  10  is described in greater detail below with respect to  FIGS. 8A through 8D . 
     As shown in  FIGS. 1 ,  6 , and  7 , the distal end  12  of device  10  may include a tip deflector  27 . Deflector  27  prevents element  17  from damaging the vessel wall on the opposite side of the puncture site. This may happen if the user excessively compresses the skin at or adjacent to the puncture site, which potentially could happen when the device  10  is being removed. Deflector  27  may be formed from a variety of medical grade materials, including flexible metal coil materials or polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. In one embodiment, deflector  27  may be formed from a small diameter wire, possibly the extension of member  16 , coated with a soft polymer material. Deflector  27  will generally have a diameter equal to or smaller than the catheter diameter at element  17  and a length in the range from about 1 cm to about 10 cm, preferably from about 2 cm to about 4 cm. A welding process may be utilized to provide for a short and strong connection point at element  17 . It will be appreciated however that the need for a deflector tip  27  may be alleviated if element  17  itself is made short and blunt. 
     Referring now to  FIG. 6 , device  10  may be equipped with a catheter loading element  28  when tensioning member  26  at its relaxed state is larger than the inner diameter of the delivery sheath in order to facilitate insertion of the device  10  through the sheath. Loading element  28  generally comprises an elongated tubular member  29 . An outer diameter of member  29  is smaller than the opening in a hub of the sheath and can penetrate a seal in the sheath. An inner diameter of loader  28  is large enough to allow the catheter  11  to completely slide through. Loader  28  has a length long enough to at least contain all the elements of the catheter  11  distal to and including the tensioning member  26 . Loader  28  may include a feature  30  at a proximal end. This feature  30  may be used as a stop against the hub of the introducer sheath, preventing the loading element  28  from completely sliding into a lumen of the sheath. Loading element  28  may be formed from coiled stainless steel tubing or polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. 
     Referring now to  FIG. 7 , introduction of the device  10 A into the sheath and removal of the device  10 A from the body may also be facilitated by incorporating a locking mechanism  33  at a proximal end of second tubular member  25  that may be interlocked with a feature  34  on a distal end of handle  19 . The locking mechanism  33 ,  34  allows tensioning member  26  to be maintained in a stretched state so as to reduce the coil diameter to below that of the inner diameter of the delivery sheath and thereby allowing the device  10 A to slide through the sheath without interference. In other embodiments, locking features on the catheter  11  may interlock with the locking mechanism  33  on member  25 . Even when member  25  is equipped with an interlocking mechanism  33  so that tensioning member  26  does not interfere with the sheath, loader  28  may still provide for enhanced introduction of the device  10 A into the sheath. 
     As shown in  FIGS. 1 ,  6 , and  7 , tubular member  11  has a visual mark  31 . When device  10  is inserted through the delivery sheath, alignment of mark  31  with the opening of the hub of the sheath indicates that catheter  10  has been advanced enough through the sheath to expose the expansible member  14  in the lumen of the vessel. Alternatively, when element  30  of loading element  28  is against the hub of the sheath, alignment of mark  31  with the proximal end of feature  30  may indicate appropriate advancement of the expansible member  14  in the vessel lumen. Optionally, alignment of the distal end of handle  19  with the hub of the sheath or loading element  30  may eliminate the need for mark  31 . Still further, mechanical means may be utilized for proper location of the expansible member  14  within the lumen of the vessel. 
     Referring now to  FIGS. 8A through 8D , a method for hemostasis of a puncture site in a body lumen employing the device of  FIG. 1  is illustrated.  FIG. 8A  depicts an existing delivery sheath  40  through an opening in a skin surface  46 , tissue tract in fascia  45 , and vessel wall  43  and seated in a vessel lumen  41  at the completion of an interventional procedure. Device  10  including loading element  28  is then inserted through the hub of the sheath  40  so that loading element  28  at least penetrates the seal of sheath  40  or until feature  30  is against the hub of the sheath  40 , as shown in  FIG. 8B . Loader  28  may now be removed. Alternatively, device  10  with loader  28  present can be pushed into sheath  40  until the identifying mark  31  on member  11  is aligned with feature  30  of loading element  28 . As shown in  FIG. 8C , expansible member  14  is then deployed by holding part  19  of handle assembly  18 A stationary and moving member  20  proximally, as depicted by arrow  8  and described in detail with respect to  FIGS. 5A through 5C . Second tubular member  25  may then be pulled proximally until resistance is felt indicating that expansible member  14  is at the distal end of sheath  40 . If member  25  is equipped with a locking mechanism  33  in a locked position, member  11  or the handle assembly  18 A may be grasped to pull the device  10  proximally and seat member  14  against the tip of the sheath  40 . Member  25  is then unlocked at this point. Optionally, the sheath  40  at the hub may be gently removed from the body so as to seat the expansible member  14 . There may be a short time period of nominal bleeding from when the distal end of the sheath  40  is removed from the vessel lumen  41  and when the expansible member  14  is set against the puncture site  42 . 
     Referring again to  FIG. 8C , once the distal end of sheath  40  exits the vessel wall  43  at puncture site  42  and the expansible member  14  is placed against the vessel wall  43  at the puncture site  42 , the resistance offered by member  14  against the vessel wall  43  will cause catheter  10  to exit the sheath  40 . The amount of interference between tensioning coil  26  and sheath  40  at points  44  determines the amount of force exerted by member  14  against the vessel wall  43 . Overcoming the friction force between the fascia  45  and the outer surface of sheath  40  as well as between the tensioning coil  26  and the sheath  40  at points  44 , sheath  40  is removed from the body exposing the loops of the coil  26  and lodging them into the fascia  45  one loop at a time. Loader  28  along with sheath  40  are removed and may be discarded. 
     Referring now to  FIG. 8D , the interference between the loops of the coil  26  and fascia  45  provides the hold and retains expansible member  14  under tension against the vessel wall  43  at the puncture site  42 . The tension applied to the expansible member  14  is sufficient for complete hemostasis, typically in a range from about 0.5 ounce to 30 ounces. When the sheath  40  and/or loader  28  are removed and the coil  26  gets embedded in the tissue  45 , the amount of the tension at the puncture site  42  may drop as the coil  26  recoils some to engage itself in the tissue  45 . The amount in the reduction of tension is dependant on the tissue type  45  surrounding the puncture site  42 , the nature of the coil spring  26 , and the thickness of the fascia  45 . These factors have been considered in the proper design of the coil  26  of the present invention. 
     If greater tension is desired once the device  10  is first seated, second tubular member  25  may be moved proximally and released increasing the amount of compression that expansible member  14  applies on the vessel wall  43 . The increase in the pull force may be limited by the amount of proximal movement of member  25 , which can be determined by the proper length of member  25  and the distance between the proximal end of member  25  and distal end of handle part  19 . The pull force may be limited by interference of members  25  and  19 . The pull force may also be limited by interference between the coil  26  and the first tubular member  11 . In particular, the closer the diameter of member  11  to the inside diameter of coil  26 , the less stretch member  26  can experience before the coil diameter is reduced enough to interfere with member  11 . In the above methodologies, when second member  25  stops moving respect to first member  11 , that may be an indication that the maximum allowable and safe pull force has been reached. 
     Device  10  remains in the body for an adequate period of time. Occlusive compression may be applied proximal to the puncture site  42  when the device  10  is to be removed. Expansible member  14  is retracted by manipulation of handle assembly  18 A and member  25  is grasped so as to pull the device  10  out of the body. Pulling on member  25  causes coil  26  to stretch, reducing the coil diameter, and consequently reducing the amount of interference between coil  26  and fascia  45 . If device  10  is equipped with locking features  33  and  34 , removal of device  10  may be accomplished by first pulling on member  25  proximally and interlocking features  33  and  34 . This easily disengages device  10  from the fascia  45 . Removal of the device  10  may be followed by a few minutes of manual compression at the skin surface  46  to achieve complete hemostasis. 
     As shown in  FIG. 8D , device  10  may include an external clip  50 . Clip  50  couples member  25  and rests on the patient&#39;s skin surface  46 . Clip  50  may be used as a safety feature to further secure and keep expansible member  14  under tension. It may also be used when greater tension is desired than that provided by interaction of coil  26  with sheath  40  and fascia  45  alone. In another embodiment (not shown), coil member  26  may be intended to function only as a tensioning member. Coil  26  in this embodiment may have a diameter smaller than the inner diameter of the sheath  40  and be formed from elastomeric material. This elastomeric member is preferably in a form of a tube which is attached to the first member  11  at point  15  and to the distal end of second member  25 . Once the device  10  is placed in the sheath  40 , and expansible member  14  is deployed, member  25  is used to place expansible member  14  against the vessel wall  43  at the puncture site  42  and to apply the required tension to the device  10 . The substantial hold once the tension is applied is then provided by external means, such as the external clip  50 . This device  10  may have the advantage of being easier to load and insert through the sheath  40  as the external clip  50  provides anchoring. 
     Referring now to  FIGS. 9A through 9C , a still further embodiment of the expansible member  60  of the present invention is illustrated. The expansible member  60  preferably comprises coiled string constructed from small diameter tubing that is flexible. The tubular configuration may have a suture or small diameter wire in its lumen to add to its tensile strength. Flexible member  60  may be formed from medical grade materials, including polymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Flexible member  60  can be coiled into an expanded configuration comprising a disc or dome shape  61 . Adjacent loops of member  60  may be adhered lightly through a heating or a gluing process. Member  60  at the center is fed through a tube  62 , wrapped around tube  62 , and is housed in a tubular member  63 , as shown in  FIG. 9A . To deploy the expansible member  60 , tube  62  is pushed forward to expose the expansible member  61 . Once extracted from tubular member  63 , the expansible member  61  unfolds into a disc or a dome configuration as illustrated in  FIG. 9B . The sealing process is attained by pulling on tube  62 , allowing the expansible member  61  to press against the puncture site. Retraction is effected by pulling coil  60  through tube  62 , causing the loops of the expansible member  61  to unwind as depicted by  FIG. 9C . Still further embodiments of such an expansible member are disclosed in U.S. Patent Application No. 2003/0120291, which describes a temporary seal and method for facilitating anastomosis and is also incorporated herein by reference. 
     Although certain exemplary embodiments and methods have been described in some detail, for clarity of understanding and by way of example, it will be apparent from the foregoing disclosure to those skilled in the art that variations, modifications, changes, and adaptations of such embodiments and methods may be made without departing from the true spirit and scope of the invention. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.