Abstract:
A device is proposed for inserting hemostatic material through a tissue channel and against the outside wall of a blood vessel of a patient, wherein the blood vessel wall has a puncture therein adjacent the tissue channel. The device includes a charge of hemostatic material and a hollow sheath adapted to pass through the tissue channel, the sheath having a cross sectional profile larger than the puncture. The device places the hemostatic material in the hollow sheath and advances the hemostatic material through the sheath to the outside of the vessel wall around the puncture.

Description:
This is a continuation of application Ser. No. 09/085,727 filed on May 27, 1998 now abandoned, which is a continuation of application Ser. No. 08/318,380 filed on Oct. 5, 1994, now U.S. Pat. No. 5,830,130, which is a divisional of application Ser. No. 07/746,339 filed on Aug. 16, 1991, now U.S. Pat. No. 5,391,183, which is a continuation-in-part of application Ser. No. 07/634,478 filed on Dec. 27, 1990, now abandoned. This is also a continuation of application Ser. No. 08/701,630 filed on Aug. 22, 1996 now abandoned, which is a continuation of application Ser. No. 08/318,381 filed on Oct. 5, 1994, now U.S. Pat. No. 5,591,204, which is a divisional of application Ser. No. 07/746,339 filed on Aug. 16, 1991, now U.S. Pat. No. 5,391,183, which is a continuation-in-part of application Ser. No. 07/634,478 filed on Dec. 27, 1990, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method for sealing a puncture wound in a blood vessel and a device for practicing said method. 
     2. Related Background 
     In certain medical procedures, such as cardiac catheterization, dilatation and counterpulsation, a catheter or other device is inserted into an artery, most commonly by percutaneous methods, and then fed through the arterial tree to the site where needed, frequently, the region of the heart. The site usually selected for insertion is the groin, because the femoral artery in that region is relatively easy to locate. 
     These procedures are normally initiated by insertion of an angiographic needle, followed by passing a guide wire through that needle into the artery. The needle is then removed leaving the guide wire in place. Next, a sheath-dilator set is passed over the guide wire into the artery in order to enlarge the opening sufficiently to permit entry of the catheter or other device. The dilator is then removed, leaving the sheath or guide cannula in place. The catheter or other device can then be inserted through the cannula with full confidence that when it emerges from the distal end it will be within the lumen of the artery. 
     It should be understood that the subject invention is independent of the nature of the medical device being used to treat the patient. Accordingly, the term “catheter” will be used here in a very generic and broad way to include not only “catheters” in the strict sense, but any device that is inserted into a blood vessel of the body. 
     Similarly, the subject invention is independent of the blood vessel involved. While it is anticipated that the femoral artery will be the most commonly used blood vessel, other arteries as well as veins might just as easily be involved. 
     After a procedure, for example, counterpulsation, has been completed, the sheath must be removed and the wound closed. Often, this can be accomplished simply by the application of digital pressure, generally augmented by the use of a pressure dressing. Customarily, pressure must be applied for at least ½ hour, and frequently for much longer than that. While pressure dressings often suffice, it is not uncommon for additional devices, such as sandbags, to be needed. In addition, during this period the patient must be immobilized, lest movement interfere with the closing process. Because of the pressure required, the time during which it must be applied and the need for immobilization, the procedure is painful and uncomfortable. It also requires prolonged personal attention of a health care professional. Finally, wound closures accomplished in this manner are prone to reopen unexpectedly long after closure appears to have been completed. Patients are therefore often required to remain in the hospital for 24 hours or longer. 
     Because sealing can be such a problem, cardiologists tend to use the smallest calibre catheters when performing catheterization procedures. Larger calibre catheters, however, are far preferable. An improved sealing procedure whereby larger catheters can be used without increasing the sealing difficulties would greatly facilitate cardiac catheterization. 
     A series of related devices which were designed to address some of these problems is described in U.S. Pat. Nos. 4,744,364, 4,852,568 and 4,890,612. These three patents describe a mushroom or umbrella shaped device which is used to seal the artery from the inside. The head of the device is placed within the arterial lumen and means are provided to pull and hold the underside of the head against the inside wall of the lumen. It is believed, however, that sealing from the inside can be the source of its own problems, including the promotion of clot formation inside the vessel. 
     Another method for sealing a puncture wound is described in U.S. Pat. No. 4,929,246. The approach taken there is to insert a balloon-tipped catheter into the tissue wound, inflate the balloon against the hole in the artery and then use a laser to thermally weld the wound closed. 
     The present invention is believed to overcome most of the drawbacks of the traditional method, without creating any new difficulties. This is accomplished by using a plug, preferably a collagen plug or plug of some other resorbable material, to seal the artery along its outside wall. 
     SUMMARY OF THE INVENTION 
     In its most simplified form, the instant invention involves the placing of hemostatic material against the outside wall of a punctured artery. The hemostatic material covers the entire puncture site and a hemostatic seal is formed so as to stop bleeding from the puncture wound. 
     In one embodiment, the subject invention teaches the use of a plug, preferably of fibrous collagen material. The plug is inserted into the tissue wound and is held against the outside of the artery wall so as to overlap the puncture wound. Before plug insertion, the artery is preferably clamped by the use of external digital pressure, at a point slightly upstream of the wound site. After the plug has been inserted, the upstream clamping pressure is maintained for a very short period of time, and then gently removed. Slight pressure may be maintained on the plug to hold it against the artery wall until a good seal has been established. 
     In order to insert the plug in accordance with the procedure outlined above, a special device has been designed. It is comprised of two basic components, a sheath and a plug pusher or piston. The sheath is inserted through the tissue until its leading end is near to or abuts the outer wall of the artery. Thereafter, the plug is advanced through the sheath by use of the plug pusher until the plug abuts the artery wall and overlaps the arterial puncture on all sides. Finally, after a good seal has been established, the sheath and pusher are removed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is an exploded view of one embodiment of an insertion apparatus in accordance with the instant invention. 
     FIG. 2 depicts, in cross section, one embodiment of an insertion apparatus in accordance with the instant invention. 
     FIG. 3 depicts, in cross section, a second embodiment of an insertion device in accordance with the instant invention. 
     FIG. 4 depicts, in cross section, an exploded view of a third embodiment of an insertion apparatus in accordance with the instant invention. 
     FIG. 5 is an enlarged, schematic drawing, in cross section, of an insertion site, showing a balloon catheter, having passed over a guide wire through a guide cannula into the femoral artery of a patient. 
     FIG. 6 shows the insertion site of FIG. 5 after the catheter and cannula have been removed. 
     FIG. 7 shows the insertion site of FIG. 6 after insertion of a tissue dilator in accordance with the instant invention. 
     FIG. 8 shows the insertion site of FIG. 7 after insertion of a sheath over the tissue dilator in accordance with the instant invention. 
     FIG. 9 shows the insertion site of FIG. 8 after removal of the tissue dilator and guide wire and after partial insertion of a hemostatic plug and plug pusher. 
     FIG. 10 shows the insertion site of FIG. 9 after the hemostatic plug has been pushed out of the sheath and while it is being held in intimate contact with the arterial puncture. 
     FIG. 11 shows an alternative embodiment of the instant invention wherein a collagen balloon is used to seal an arterial puncture. 
     FIGS. 12 a, b, c, d  and  e  show alternative forms of plug which are useful in practicing the instant invention. 
     FIGS. 13 through 23 show the steps of an alternate procedure for practicing the instant invention. 
    
    
     DETAILED DESCRIPTION 
     In certain procedures, for example, intra-aortic balloon pumping (“IABP”), percutaneous transluminal coronary angioplasty (“PTCA”) and angiography, as best seen in FIG. 5, a catheter or other device  7  is inserted, often over a guide wire  15 , through a guide cannula  3  into an artery  11 , most frequently, the common femoral artery in the groin area of the patient&#39;s leg  1 . When the procedure (e.g., counterpulsation) has been completed, the device (e.g., the catheter), the guide wire and the guide cannula must be removed and the wound closed. 
     In accordance with one embodiment of the instant invention, wounds of this type are closed by inserting a hemostatic material, either in the form of a plug of loose fibers or compressed or partially compressed fibers, or in the form of a sponge, a liquid, or a paste-like material, into tissue wound or channel  9 , and holding it against the outside of the artery wall over arterial puncture  13  for a short period of time until a good self-sustaining hemostatic seal is established. Although punctures of the sort made by percutaneous procedures will generally, after removal of all cannulas and catheters, be in the nature of slits, for ease of understanding, they are depicted in the drawings herein more as holes. The shape of the puncture, however, is not critical. 
     In order to insert the plug, to assure that it is properly located and to be able to hold it in place until a good seal is established, a special insertion apparatus has been designed. One embodiment (FIG. 1) of an insertion apparatus according to the instant invention is comprised of a sheath assembly  23 , a plug holder  29  and a plug pusher  33 . Sheath assembly  23 , in turn, is comprised of an elongated tubular sheath  45  and a collar  35 . At its rear end, collar  35  is provided with an external thread  37 . In addition, sheath assembly  23  is provided with a sheath channel  27 , which runs through the entire assembly, from front end  25 , through sheath  45  and through collar  35 . 
     Plug holder  29  is comprised of an elongated rear tubular portion  47  and a coupling  39  which has an internal thread  41 . Plug holder  29  also has a channel  31  running throughout its entire length. Coupling thread  41  is designed to mate with collar thread  37  so that when collar  35  is screwed into coupling  39 , channels  31  and  27 , which preferably are of the same cross sectional size and configuration, are aligned. 
     Like the other two components, the plug pusher  33  is also comprised of two parts, an elongated piston  49 , and a stop knob  43 . Piston  49  has a cross sectional size and configuration so as to permit sliding passage into channels  31  and  27  with only minimal clearance. The length of piston  49  is such that when sheath assembly  23  and plug holder  29  are screwed tightly together, shoulder  51  of knob  43  will abut rear end  53  of plug holder  29  as front end  55  of piston  49  is aligned with front end  25  of sheath  45 . 
     It should be noted that pusher  33  is provided with its own channel  19 . This is to permit passage therethrough of a guide wire and hence to enable pusher  33  to serve dual functions, as a tissue dilator and as a plug pusher. 
     In accordance with the method of the instant invention, first the device  7  (e.g., the IAB) and the guide cannula  3  are removed, leaving the guide wire  15  in place (as seen in FIG.  6 ). If no guide wire has been employed, prior to removal of the catheter and cannula, a guide wire may be inserted. As the cannula is withdrawn, in order to prevent bleeding, the artery is clamped, usually by pressing a finger  2  over the femoral artery upstream of the wound site. Because of this clamping, there is no significant blood pressure inside the artery at the site of the puncture (other than some small retrograde pressure) and the artery tends to collapse. 
     Although it is believed preferable to employ a guide wire, it is possible to practice the invention without one. It is also possible to practice the instant invention by eliminating the dilator, but this too is not the preferred approach. 
     The artery is clamped at least in part to prevent tissue channel  9  from filling with a pool of blood. When loose fibrous collagen encounters a pool of blood it tends to disintegrate almost immediately. Obviously, once disintegrated it cannot function properly to seal the arterial puncture. Hence, when collagen in loose fibrous form is employed, clamping of the artery is important. It is less important, but still generally advantageous, if the loose fibrous material has been tamped down or otherwise compressed. As used herein, the term “loose” includes material which has been compressed or tamped down. 
     Collagen that is more densely packed does not disintegrate upon encountering blood nearly as quickly as loose fibrous collagen. Therefore, clamping of the artery is not nearly as important when the hemostatic material is in the form of a densely packed material, as it is when a loose fleece-type hemostatic material is employed. Thus, although clamping is believed to be desireable, it is not, in all cases essential. 
     While the artery remains clamped, the proximal end of guide wire  15  is fed through channel  20  of tissue dilator  17 . The physician can then slide the dilator down along the guide wire into tissue channel  9  until it reaches the wall of artery  11  (as depicted in FIG.  7 ). 
     The size and shape of the tissue dilator are such as to ensure that the body thereof will not enter the artery. In terms of size, preferably a dilator is selected which is significantly larger than the original guide cannula  3 . With respect to its shape, unlike more traditional dilators which often have long tapered forward ends, the tissue dilator  17  of the instant invention has a blunt forward end  21 . Although end  21  may be slightly rounded or chamfered in order to facilitate smooth passage through tissue channel  9 , it is preferable not to reduce it in size sufficiently to permit entry through the arterial puncture  13  into the lumen of the artery. 
     As noted above, during this phase of the procedure, there is no significant blood pressure in the region of artery  11  adjacent puncture  13 . As a result, when end  21  of dilator  17  reaches artery  11 , the wall of the artery tends to collapse further (as depicted in FIG.  7 ). The physician knows that the dilator has reached the artery because a noticeable increase in resistance is felt. 
     According to the procedure of the instant invention, once increased resistance is encountered, axial pressure is maintained so as to hold end  21  of dilator  17  against artery  11 . Next, a sheath  45  is passed over dilator  17  and advanced along the dilator again until increased resistance is encountered. As with the dilator, increased resistance indicates that front end  25  is against artery  11  (as depicted in FIG.  8 ). In addition, a marker can be placed around the circumference of the dilator to signal when the distal end of the sheath is aligned with the distal end of the dilator. 
     Because end  25  of sheath  45  is larger than arterial puncture  9 , the sheath cannot enter the arterial puncture. Although the precise dimensions of dilator  17  and sheath  45  are not critical, it is believed desirable that the sheath  45  be 30% to 50% or more larger than the previously removed guide cannula  3 . In clinical trials done to date, when the guide cannula was 9 Fr., a 13 Fr. tissue dilator and a 14 Fr. sheath were used. It should be understood, however, that cannulae which are oversized by as little as 10% may also be suitable. 
     Once the guide or procedure cannula has been removed, tissue channel  9  tends to collapse. Also, once the procedure cannula and the procedure catheter have been removed, arterial puncture  13  has a tendency to close up. It may therefore be possible or even preferable to use a sheath that is the same size as or even smaller than the previously removed procedure cannula. 
     With the front end  25  of sheath  45  held snugly against the wall of artery  11 , plug  57  is slid down through lumen  27  of sheath  45  (as shown in FIG. 9) until it reaches end  25  of sheath  45  where it encounters artery  11 . If an insertion apparatus like that shown in FIG. 1 is used, plug  57  is initially housed in plug holder  29 . When it is time for plug insertion, holder  29  is screwed onto sheath assembly  23  by means of threads  37  and  41 , and piston  49  is inserted into channel  31 . Advancement of the piston then forces plug  57  from holder  29  into sheath  45  and through lumen  27  to the artery wall. 
     Once resistance is felt, the physician slowly withdraws the sheath while continuing to maintain pressure against the piston so that plug  57  remains pressed against artery  11 . When shoulder  51  of knob  43  abuts rear end  53  of holder  29 , the physician knows that plug  57  has been pushed entirely out of lumen  27  (as shown in FIG.  10 ). Axial pressure is maintained for a short period of time, perhaps as little as one minute or as long as five minutes, depending upon the circumstances, to allow plug  57  to seat in tissue channel  9  and against arterial puncture  13 . Minimal axial pressure is thereafter continued while clamping pressure is slowly released until a good self-sustaining hemostatic seal has been confirmed. The sheath, holder, and pusher can all then be removed. 
     While it is believed that the preferable procedure is to permit both piston and sheath to remain in place until a self-sustaining hemostatic seal has been achieved, this is not absolutely necessary. Some physicians may prefer, once the pressure of the plug against the artery wall has produced hemostasis, to withdraw the sheath so that the tissue wound may begin to close down, while maintaining pressure on the plug by use of the piston alone. Alternatively, the piston might be withdrawn and reliance placed upon the outer rim of the sheath to hold the plug against the artery wall and assure hemostasis in that manner. 
     In addition, removal of the piston without removal of the sheath permits insertion of a second plug. This might be necessary where the first plug, perhaps of a loose fibrous material, disintegrates upon encountering a pool of blood. A second plug, this one of more densely packed material having greater physical integrity and less of a tendency toward immediate disintegration, is inserted in the sheath and the piston reinserted behind it. 
     An apparatus similar to that of FIG. 1 is depicted in FIG.  4 . The primary difference between the two is that the plug pusher of the FIG. 4 embodiment does not serve a dual function. Instead, the embodiment of FIG. 4 has a separate tissue dilator  17  with channel  20  running throughout its length. 
     Another, somewhat different embodiment of an apparatus for inserting a plug in accordance with the instant invention is depicted in FIG.  2 . The insertion apparatus  59  of that embodiment is made in the form of a Y, with a common or sheath leg  61 , a plug leg  63  and a dilator leg  65 . 
     In one method of using the apparatus of FIG. 2, tissue dilator  17  and insertion apparatus  59  are preassembled by passing the dilator through legs  65  and  61  until enough of dilator  17  extends beyond the forward end of leg  61  to assure that end  21  will abut artery  11  before front end  26  of leg  21  reaches the surface of the patient&#39;s leg. The proximal end of the guide wire is then fed through dilator channel  20  and the dilator is slid down the guide wire into tissue wound  9  until end  21  of dilator  17  reaches the wall of artery  11 . While holding the dilator against the artery wall, the physician slides insertion apparatus  59  along dilator  17  until end  26  of leg  61  reaches artery  11 . 
     With end  26  held snugly against artery  11 , dilator  17  is withdrawn, but only far enough so as to uncover channel  67  of plug leg  63 . Plug pusher  69  is then moved down through channel  67  until plug  57  has entered common leg  61  and pusher  69  is then withdrawn so that it will not interfere with dilator  17  as it passes from leg  65  into leg  61 . 
     Once plug  57  has entered leg  61  and pusher  69  has been retracted, dilator  17  is again advanced into leg  61 . When resistance is encountered, the physician knows that plug  57  has reached the artery. While maintaining axial pressure on dilator  17 , apparatus  59  is slowly withdrawn until proximal end  73  of leg  65  reaches indicator mark  71 . The distance between indicator  71  and dilator end  21  is the same as the distance between proximal end  73  and forward end  26 . Therefore, the physician knows that when mark  71  reaches end  73 , all of plug  57  has exited from end  26  of leg  61 . As was described in connection with the embodiment of FIG. 1, pressure is then maintained until a good self-sustaining hemostatic seal has been established. 
     The embodiment of FIG. 3 is very similar to that of FIG. 1, except that the dilator and plug legs have been transposed. In the FIG. 3 embodiment, plug leg  74  is coaxial with common leg  61  and dilator leg  75  is at an angle, whereas in the FIG. 2 embodiment the reverse is true. 
     Although it is believed that the preferred method for using the embodiment of FIG. 2 is to preassemble dilator  17  in apparatus  59 , that is by no means necessary. If the physician prefers, he can just as well insert dilator  17  into tissue channel  9  as was described above in connection with the embodiment of FIG.  1 . He can then pass leg  61  over it. With the embodiment of FIGS. 4 and 1, while it is believed preferable to insert dilator  17  first, the physician, if he prefers, can preassemble the dilator in the sheath before passing the dilator over the guide wire. 
     While plug  57  may be made of any resorbable material, collagen is believed to be most suitable. The physical form of the plug may vary widely, with the one selected by the physician being dependent upon the circumstances of the case. For example, where the puncture wound is relatively small and the patient has not been on high doses of anticoagulant and heparin, a plug, like that depicted in FIG. 12 a , of loose fibrous material, somewhat like fleece or absorbent cotton or oxygenated cellulose, would serve quite well. Alternatively, for larger wounds in patients who have been on anticoagulants and heparin, it may be necessary that the plug be able to maintain some structural integrity for a longer period of time. Under those circumstances, a plug of more densely packed material, as depicted in FIG. 12 b , might be preferred. 
     A third embodiment of a suitable plug is depicted in FIG. 12 c . In that embodiment, the front end  77  of the plug might be of loose fibrous material, like that depicted in FIG. 12 a , whereas the remainder  79  could be made of a more densely packed material. 
     Yet another type of plug is shown in FIG. 12 d . In this configuration, the front end  81  is a collagen membrane and the remainder  83  is an expandable collagen sponge. 
     It is believed that when a collagen sponge or a densely packed collagen material are employed, very little if any pressure need be applied after the initial seating of the plug. This is believed to be true because the physical characteristics of the sponge-like or densely packed plug and the expansion thereof, as well as its interaction with body fluids in the tissue channel will be adequate to hold the front end against the artery wall. 
     It is also believed that, initially, when the plug is pressed against the artery, hemostasis is achieved by mechanical means, i.e., by application of mechanical pressure all around the arterial puncture. Shortly thereafter, however, the hemostatic material begins to bind to the arterial tissue and biochemical hemostasis takes over. Once biochemical hemostasis becomes sufficiently strong to withstand the normal blood pressure within the artery, and therefore self-sustaining, external mechanical pressure can be removed. 
     FIG. 12 e  shows yet another form of plug, similar to the plug of FIG. 12 d , but with a lumen  85 . This form of plug is designed for use by physicians who prefer not to remove the guide wire immediately after a procedure. The proximal end of the guide wire  15  can be fed through lumen  85  and through the collagen membrane  81 . The plug is slid down along the guide wire through tissue channel  9  until its front end reaches the wall of the femoral artery. Indeed, the plug of FIG. 12 e  could even be inserted without the use of a sheath. When the wire  15  is withdrawn, the collagen membrane automatically reseals itself. 
     As noted earlier, the sheath is substantially larger in cross section than is arterial puncture  13 . Consequently, when plug  57 , which fills the entire cross section of the sheath channel, reaches the artery, even in its compressed state it overlaps puncture  13  on all sides. Obviously, then, when it exits the sheath and is permitted to expand, a full bandage-like covering over puncture  13  is assured. 
     In practice it has been found that when using a collagen plug in accordance with the subject invention, a good hemostatic seal can be achieved in five minutes or less. With larger wounds, for example, ones left after removal of 14 Fr. or larger catheters, or after the use of anticoagulants and heparin, sealing may take somewhat longer. 
     FIG. 11 depicts another means for practicing the instant invention. In this embodiment a piston  18  pushes ahead of its front end a closed balloon  87  formed of a collagen membrane and only partially filled with a collagen substance and a saline solution. The piston  18  has an injection needle  18   a  on its front end which pierces the balloon during the pushing action. 
     After the balloon  87  exits from the sheath  23  and is pressed against the wall of the artery  11 , an inflation fluid is injected via the needle  18   a  to fill and expand the balloon, as shown in FIG. 11, so that the balloon covers the arterial puncture  13  and fills the region of tissue channel  9  immediately adjacent the arterial puncture  13 . The piston  18  is thereafter retracted to withdraw the injection needle  18   a  from the balloon  87 . The membrane which forms the balloon  87  then automatically reseals itself to hold the balloon in the inflated condition shown in FIG.  11 . The sheath  23  and piston  18  may then be withdrawn. When using this embodiment, the inflation fluid itself should be resorbable, preferably a saline solution or saline mixed with collagen in solution. 
     As noted above, when the procedure cannula is removed, both the arterial puncture  13  and the tissue channel  9  tend to close up somewhat. The method depicted in FIG. 13 through 22 is designed to take advantage of this tendency. In the FIGS. 13-22 method, neither the hemostasis sheath  45  nor the dilator  17  are pushed through channel  9  all the way to arterial puncture  13 . Instead, as shown at  89  in FIGS. 14,  14 A,  15  and  15 A they are inserted no further than to within about ¾ cm. of the artery. 
     First, digital pressure (see arrows  105  in FIGS. 13-21) is applied upstream of the wound so as to close down the artery (see arrows  106 ). In this way the pressure in the artery at the puncture site  13  is no more than about atmospheric pressure. Although the method of this invention could be practiced without applying digital pressure, that would likely result in more profuse bleeding. 
     Then, as shown in FIG. 13, the dilator  17  is inserted over guide wire  15  to about ¾ cm from puncture  13 . It will generally be inserted so that between about 3 and about 6 cm. of its length is beneath the surface of the skin. 
     One method for assuring that the sheath is inserted to the proper depth is as follows. Once the artery  107  has been punctured and the guide wire is in place, a needle clamp  108 , as is depicted in FIG. 23, is placed on the needle  109  at the skin line  110 . With the clamp in place, the needle is removed from the patient. The needle can then be placed along side the sheath and a mark made on the sheath to indicate the distance from needle tip to needle clamp. Alternatively, a mark can be made ½ or ¾ cm. closer to the distal end of the sheath. As yet another alternative, a kit can be provided of variable length sheaths, each having a hub at one end, and from that kit a sheath of the proper length, i.e., one having a total length, from hub to distal end, of ½ or ¾ cm. less than the distance from needle tip to needle clamp can be selected. 
     Next, as is best seen in FIG. 14, the sheath  45  is slid down over the dilator, again stopping when its distal tip is about ¾ cm. from the arterial puncture  13 . The sheath and dilator can be inserted separately, i.e., in two steps, or together as a unit, in one step. 
     As can be seen in FIGS. 14 a  and  15   a , the partially collapsed section of tissue channel  9  which is immediately adjacent puncture  13  is not reexpanded. Instead, it remains undisturbed. 
     The next step is to withdraw dilator  17  (as is indicated by arrow A on FIG. 15) with guide wire  15  (see FIG.  15 ), leaving only sheath  45  in tissue channel  9 . As depicted in FIG. 16, a preloaded holder or cartridge  91  with plug  93  therein is inserted (see arrow B) into sheath chamber  97 . As cartridge  91  is fully seated within chamber  97 , a plunger  95  is used to push (see arrow C) plug  93  into and through sheath  45  until the plug exits the sheath so as to cover puncture  13  and fill that section of channel  9  which is adjacent puncture  13  (see FIGS. 17 and 17 a ). Simultaneously, sheath  45  is slightly withdrawn (indicated by arrows D on FIG. 17) to permit plug  93  to be fully discharged from the sheath. 
     Plunger  95  is then withdrawn, leaving sheath  45  to maintain pressure on plug  93 . Sheath  45  can then be used to hold plug  93  in place over puncture  13  until self sustaining hemostasis has been achieved. Alternatively, as depicted in FIG. 18, a second preloaded holder or cartridge  99  can then be inserted (see arrow E) into chamber  97 . Once again, a plunger,  103  is used to push (see arrow F) plug  101  through the sheath. Preferably, plug  101  should be long enough so that when fully discharged from the sheath (as depicted in FIG.  21 ), it will fill substantially all of channel  9 , reaching almost to the surface of the skin. 
     When the front end of plug  101  reaches the end of sheath  45 , it abuts plug  93 . Plunger  103  is then used to force about 1 cm. of plug  101  out of the sheath ( 107  on FIG.  19 ). In this way, plug  101  takes over the function of holding plug  93  in place against puncture  13 . While plunger  103  continues to hold plug  101  in place (see arrow H), sheath  45  is withdrawn from channel  9  (see arrows G on FIG.  20 ). As can be seen in FIG. 22, when sheath  45  is fully withdrawn, plugs  93  and  101  fill substantially all of channel  9 . 
     It is believed to be most desireable that the front plug  93  be of loosely packed material, while rear plug  101  be of a more densely packed material. Also, as presently contemplated, in its natural, unrestrained state, plug  101  has a cross section larger than that of cartridge  99 . Therefore, in order to get it into the cartridge, it must be compressed. It then stays in this compressed state while in cartridge  99  as well as while passing through sheath  45 . However, after exiting from sheath  45 , it naturally expands and presses against the walls of channel  9 . The interaction then between plug  101  and the walls of channel  9  tends to hold the plug in place. As a result, very little if any external pressure is required. 
     Accordingly, after only a very short period of time, perhaps almost immediately, the plunger can be removed, leaving only the two plugs in the wound (see FIG.  21 ). Pressure on the artery (see arrows  105  in FIGS. 13-21) can then be released, permitting normal flow through the artery to resume. 
     Although it is not necessary, in the practice of the method of the instant invention, for plugs  93  and  101  to fill all of channel  9  from artery to skin line, it is believed preferable that they do so. Alternatively, plug  101  can be made longer than necessary to reach the skin line, in which case it could then be cut off flush with the skin. As yet another alternative, a single plug, the size of plugs  93  and  101  combined could be used instead of two separate plugs. 
     While it is believed most advantageous to remove the procedure cannula and then insert a new sheath, it would be within the scope of the instant invention to use the procedure cannula as the delivery sheath through which the hemostatic material is passed. 
     It should also be understood that the hemostatic material employed may take many forms. For example, it may be in the form of a liquid or it may have a more viscous paste-like consistency and in both the cases of the hemostatic material being in the form of a liquid or having a viscous paste-like consistency, it can specifically include such hemostatic materials as fibrin glue and thrombin. When using such liquid or paste-like materials, the delivery sheath, the hemostatic charge holder and the piston might most advantageously be combined together in a single syringe-like device. 
     While the method and apparatus of this invention have been described in connection with several specific embodiments, it should be understood that numerous modifications could be made by persons of skill in this art without departing from the scope of this invention. Accordingly, the above description is intended to be merely illustrative and not limiting. The scope of the invention claimed should be understood as including all those alternatives and modifications which the above specification would readily suggest or which would readily occur or be apparent to one skilled in the art upon reading the above.