Abstract:
Multipurpose fluid applicators and applicator tips, particularly suitable for surgical purposes, are disclosed. The applicators and applicator tips are specifically designed for dispensing various combinations of sterile pressurized gas, suction, irrigation and sealant agents, including a mixed liquid sealant agent. Preferred embodiments employ a dual-acting valve selectively to control the flow of gas or suction which valve is capable of simultaneously varying flow from a source and the venting of that flow to atmosphere.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from U.S. provisional patent application serial No. 60/096,940 filed on Aug. 18, 1998. The present application also is a continuation-in-part of co-pending U.S. patent application Ser. No. 08/838,078 filed on Apr. 14,1997, now U.S. Pat. No. 6,331,172, and a continuation in part U.S. patent application Ser. No. 08/839,614, filed on Apr. 14, 1997, now U.S. Pat. No. 5,971,956, and a continuation-in-part of U.S. patent application Ser. No. 08/946,364, filed on Oct. 7, 1997, now U.S. Pat. No. 6,007,515, and a continuation-in-part of U.S. patent application Ser. No. 09/037,160, filed on Mar. 9, 1998, now U.S. Pat. No. 6,063,055, all naming Gordon H. Epstein as first named inventor. Also, the present application is a continuaton-in-part of U.S. patent application Ser. No. 09/315,702, filed on May 20, 1999, naming Mitchel Levinson as first named inventor. The disclosures of the aforementioned United States patent applications are hereby incorporated by reference In their entirety herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCHER DEVELOPMENT 
     (Not Applicable) 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and method for applying component parts of a sealant which when mixed transforms from a fluidic state to a non-fluidic state. In particular but not exclusively, the present invention is directed to an apparatus and process in which sealant components are mixed prior to being applied to biological tissue to effect hemostasis or achieve other therapeutic results. 
     2. Description of Related Art Including Information Disclosed under 37 CFR 1.97 and 37 CFR 1.98 
     Use of tissue sealants and other biological materials is an important emerging surgical technique, well adapted for the operating room or field environments such as the doctor&#39;s office or mobile medical units. In addition, the application of such sealants while performing or as necessary to perform minimimally invasive surgery reduces or eliminated the traditional problems associated with more invasive types of procedures. Preferred sealants include fibrin sealants which are formed from blood plasma components and comprise, on the one hand, a first component containing fibrinogen and Factor XIII and on the other hand a second component which usually includes thrombin, and calcium ions. 
     The fibrinogen is capable of a polymerizing and being cross-linked to form a solid fibrin clot when the components are mixed. The necessary additional factors to simulate relevant portions of the natural blood coagulation cascade are suitably distributed between the fibrinogen and thrombin components. 
     High levels of protection against transmission of infections or induction of immunological reactions can be assured by using an autologous or single-donor source for both components. Such sealants are highly effective, are biologically degraded without residue and may promote wound healing. 
     Depending upon the potency of the particular formulations employed, coagulation of the sealant may take place very rapidly, yielding a gel within perhaps 10 or 20 seconds after mixing of the two components. Though often very desirable for surgical reasons, such fast-acting properties present potential problems of fouling or clogging. These problems must be overcome in devising suitable applicators, and methods of application. 
     A popular manually operable applicator for such two-component sealants employs a dual syringe construction wherein two syringes, connected by a yolce, each provide a reservoir for one of the components. In most prior devices, the sealant components are discharged in separate streams and mixed externally of the applicator. Such applicators are similar in principle to household epoxy glue applicators commonly available in hardware stores. Achieving effective mixing externally of the applicator is problematic. 
     In U.S. Pat. No. 5,266,877, and the above applications, the present inventor teaches various constructions of a dual syringe applicator wherein the fluid sealant components are mixed internally. 
     Antanavich et al. U.S. Pat. No. 5,585,007, whose disclosure and references are hereby incorporated herein by reference thereto, provides an extensive discussion of the literature relating to fibrinogen sealant preparation (column 1, line 20 to column 4, line 62) and applicators column 4 line 62 to column 5, line 14), as well as a bibliography, (columns 6-10) and is a helpful guide to the teachings of prior workers in the field. 
     Though a superior quality sealant can be obtained, a difficulty with internal mixing is that the coagulating nature of the sealants causes the discharge opening or openings of an application device to become clogged so that flow out of the applicator slows down or stops. 
     While the above-referenced copending applications disclose effective clearing methods, difficulties may occur if the mixing pathway to be cleared has an extended length such as might be required to reach an unexposed location or work site. 
     There is accordingly a need for a sealant applicator and method that can be used to reach an unexposed location and that is capable of being rapidly unclogged without disassembly of the applicator. 
     SUMMARY OF THE INVENTION 
     The present invention solves this problem by providing an applicator tip comprising a mixing chamber communicating with two or more reservoirs which can effectively deliver mixed multiple sealant components to a remote work area and is capable of being unclogged without removing or relocating the applicator tip or by dispersing unwanted clots into the application environment. 
     The present invention also assures that an effective sealant composition reaches the area of application because the sealant components are actively mixed in close proximity to the applicator outlet while also providing for means of removal of coagulated sealant from the applicator tip. 
     Preferably, although not necessarily, the sealant is a biological sealant, for example a tissue adhesive, and the area of application is a biological tissue subject to surgery. The sealant components can comprise a first, structural component capable of gelling, and preferably of solidification and a second, activation component which activates such gelling and, optionally, solidification. More preferably, the sealant is a tissue sealant and the first component comprises fibrinogen and the second component comprises, or can generate a fibrinogen activator, especially thrombin or an equivalent thereof. 
     The invention also provides a novel surgical method of applying sealant to unexposed or internal biological surfaces, e.g. human or animal anatomical surfaces, that are accessible to a remote application devices, such as the ones disclosed in aforementioned patent applications. The use of a remote mixing chamber, which receives a flow of multiple sealant components and mixes the sealant components at the distal end of the applicator, allows the distal end of the applicator to apply a mixed sealant a work site. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One way of carrying out the invention is described in detail below with reference to the drawings which illustrate one or more specific embodiments of the invention and in which: 
     FIG. 1 is a top plan view of a first embodiment of a sealant applicator tip according to the present invention; 
     FIG. 2 is a perspective view of the FIG. 1 embodiment showing a rotatable plate in a first position; 
     FIG. 3 is a perspective view of the FIG. 1 embodiment showing a rotatable plate in a second position; 
     FIG. 4 is a top plan view of a second embodiment of the present invention; 
     FIG. 5 a  is a cross sectional view along the lines  5 — 5  of FIG. 4 in a first position; 
     FIG. 5 b  is a cross sectional view along the lines  5 — 5  of FIG. 4 in a second position; 
     FIG. 6 is a top plan view of a third embodiment of the present invention; 
     FIG. 7 a  is a cross sectional view along lines  7 — 7  of FIG. 6 in a first position; 
     FIG. 7 b  is a cross sectional view along lines  7 — 7  of FIG. 6 in a second position; 
     FIG. 7 c  is a cross sectional view of the FIG. 6 embodiment; 
     FIGS. 8 a-b  is a cross sectional view of a fourth embodiment of the present invention; 
     FIGS. 9 a-b  is a cross sectional view of a fifth embodiment of the present invention; 
     FIGS. 10 a-b  is a cross sectional view of a sixth embodiment of the present invention; 
     FIGS. 11 a-b  is a cross sectional view of a seventh embodiment of the present invention; 
     FIGS. 12 a-b  is a cross sectional view of an eighth embodiment of the present invention; 
     FIGS. 13 a-b  is a cross sectional view of a ninth embodiment of the present invention; 
     FIGS. 14 a-c  illustrate a sealant application instrument for use with the present invention; and 
     FIG. 14 d  is a cross sectional view along lines  14   d — 14   d  of FIG.  14   a.   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIGS. 1-3, a sealant applicator tip  10 , for use with a sealant application instrument (FIGS. 14 a-c ) is illustrated. Tip  10  is generally conical in shape and is configured to have an internal mixing chamber  12 . Mixing chamber  12  communicates with a pair of conduits  14  and  16  which each supply a sealant agent  18  or  20 , respectively, for internal mixing in mixing chamber  12 . Preferably, agents  18  and  20  are those disclosed in the aforementioned patent applications, and are manually dispersed under pressure applied by the user from reservoirs (not shown). 
     As previously discussed, once mixed, agents  18  and  20  provide a sealant  22  which is used for application to a remote area. Sealant  22  travels through an application conduit  24  which is configured to deliver sealant  22  to an application opening  26 . 
     The coagulating nature of the sealant sometimes causes the discharge opening or openings of an application device to become clogged so that flow out of the applicator slows down or stops. 
     Thus, it is one aspect of the present invention to provide for retrograde clearing of the mixing chamber while also limiting the flow of agents  18  and  20  during such clearing. 
     Tip  10  is mounted to a pin  28  which is slidably received within an opening  29  (FIG.  3 ). As illustrated in FIGS. 1-3, to provide an extended reach, the application device (see FIGS. 14 a-c ) is equipped with an elongated shaft  32  having applicator tip  10  removably mounted to the distal end of the device. 
     As an alternative or as a supplement conduits  14  and  16 , are used to deliver an irrigation fluid and/or pressurized gas as well as agents  18  and  20 . 
     Although described in the context of an applicator with an extension tip, it will be understood that the sealant valving and clearing mechanisms disclosed herein can also be embodied in other applications such as those having relatively shorter tips, as disclosed in the above applications. 
     To facilitate the clearing of mixing chamber  12 , a circular plate  30  is rotatably mounted on pin  28 . Plate  30  is located between tip  10  and shaft  32  and is rotated either manually by the user or is rotated through the incorporation of a remotely positioned actuating device, such as a trigger  150  (see FIG. 14 a ). 
     As an alternative, pin  28  and accordingly plate  30  is rotated from a position remote from tip  10 . This rotation can also be facilitated through trigger  150 . 
     Tip  10  is slidably mounted to shaft  32  via pin  28 . Pin  28  slides into and away from shaft  32 . This allows tip  10  to be moved in the directions of arrow  34  and to the positions illustrated by FIGS. 1-3. 
     Referring now in particular to FIGS. 2 and 3, circular plate  30  is capable of being rotated in the directions indicated by arrow  36 . Circular plate  30  has a pair of openings  38  and an opening  40 . Openings  38  are configured to align with conduits  14  and  16  when circular plate  30  is in the position depicted by FIG.  3 . Opening  40  is configured to align with mixing chamber  12  when circular plate  30  is in the position depicted by FIG.  2 . In addition, opening  40  is larger than openings  38 . In the preferred embodiment, opening  40  is as large as mixing chamber  12 . The larger size of opening  40  helps facilitate the removal of clotted material from mixing chamber  12 . 
     If desired, conduits  14  and  16 , and openings  38  can be radially offset to avoid cross contamination as plate  30  rotates. 
     Accordingly, and as can be seen by FIGS. 1-3, to remove coagulated sealant that has partially or totally clogged conduit  22 , a user manipulates plate  30  to the position illustrated by FIG.  2 . In this position conduits  14  and  16  are blocked off by circular plate  30  while mixing chamber  12  is aligned to opening  40  which allows a suction force to be applied to mixing chamber  12  via conduit  42 . 
     Thus, circular plate  30  may be rotated to allow for application of sealant  22  or removal of coagulated sealant from mixing chamber  12 . 
     Once circular plate  30  is placed into the desired position, the user then will either apply sealant  22  or remove coagulated sealant from mixing chamber  12 . 
     To facilitate removal of coagulated sealant a suction force is applied to mixing chamber  12  via a suction conduit  42 . Accordingly, retrograde clearing of mixing chamber  12 , application conduit  24  and opening  26  is possible. Thus, the present invention allows a user to clear applicator tip  10  should it become clogged. This feature is of particular importance especially if tip  10  becomes clogged during a surgical procedure. In accordance with the present invention the user can clear the clogged passage in a quick and easy manner convenient to the user. In addition, retrograde clearing prevents coagulated sealant from being dispersed into the application area. 
     Tip  10  may also be completely removed to insert another tip which has different features, such as, a more elongated nose shape, a larger or smaller application opening, an angular configuration to the distal end of tip  10  or any other configuration which would vary the application of sealant  22 . In addition, tip  10  may even be disposed being replaced with a new tip, for example, for each patient. 
     Optionally, to prevent inadvertent removal of tip  10 , pin  28  is equipped with a retaining device  31 . Retaining device  31  prevents pin  28  from being completely removed from shaft  32 . As an example, retaining device may be an end stop with a larger diameter than opening  29 . 
     In addition, the movement of tip  10  away from shaft  32  may also be limited by a locking mechanism, such as a spring loaded ball bearing device, which is received into recesses positioned along opening  29  and can lock tip  10  into position at differing spacings from shaft  32 . 
     A preferred external configuration of tip  10  is that of a blunt pencil tip, as shown, facilitating access to internal locations of a treatment subject, providing a manipulable dispersing tip and avoiding tissue damage by sharp or bulky protuberances. 
     In addition and as an alternative embodiment, and when retrograde suction is applied to mixing chamber  12 , conduits  14  and  16  are equipped with one way flap valves  15  and  17  respectively (see the dashed lines in FIG.  1 ). Flap valves  15  and  17  prevent flow from mixing chamber  12  back into conduits  14  and  16 . In this embodiment retrograde suction may also be applied to conduits  14  and  16  which will draw back sealant agents  18  and  20  but not any coagulated or mixed sealant  22 . Thus, and in this embodiment, retrograde suction may be applied to remove coagulated sealant  22  without drawing sealant agent  18  and  20  with it. 
     In yet another embodiment, valves  15  and  17  are used to completely close off conduits  14  and  16  and are actuated to close when retrograde suction is applied to mixing chamber  12 . 
     Alternatively, conduits  14  and  16 , which in accordance with the co-pending and commonly owned patent applications, are flexible and capable of being easily manipulated. In this embodiment, the flexible nature of conduits  14  and  16  allows for them to be pinched or easily constricted to prevent flow therethrough. Accordingly, conduits  14  and  16  are pinched to prevent flow of sealant agents  18  and  20  when retrograde suction is applied to mixing chamber  12 . 
     Such pinching of conduits  14  and  16  can be performed at either the distal or proximal end of an application device, such as the one depicted in FIG. 14 a  and the above mentioned copending patent applications. 
     Pinching of conduits  14  and  16 , at either the proximal or distal end of the application device, in addition to sealing off conduits  14  and  16  for retrograde clearing, will also provide a hydraulic force or surge through conduits  14  and  16 . This will force out a small amount of agents  18  and  20 , prior to the application of retrograde suction. 
     This forcing of a small amount of agents  18  and  20  out of conduits  14  and  16  will assist in dislodging coagulated sealant  22  from the openings of conduits  14  and  16  communicating with mixing chamber  12 . 
     Locating the mechanism for the pinching of conduits  14  and  16  at the proximal end of the application device will provide the user with an ergonomic means for closing off of conduits  14  and  16 . 
     Accordingly, a trigger manipulated device can be ergonomically placed for the user to pinch off conduits  14  and  16  and create a hydraulic force of sealants  18  and  20  for dislodging any coagulated mixed sealant  22 . 
     As illustrated in FIG. 14 d  a pair of flexible hinges  21  manipulated by a user activated trigger can effectively pinch conduits  14  and  16  into the position illustrated by the dashed lines. Such manipulation creates a force of sealant  18  and  20  in the direction of arrows  19 . 
     As an alternative, hinges  21  can be replaced by, a slidable roller, a slidable shuttle having an opening that reduces in size and effectively pinches off conduits  14  and  16 , or any other mechanical equivalent that can pinch off conduits  14  and  16  through the use of user applied force which returns to its unconstricting position after the force is removed. 
     In addition, such placement proximal placement of the pinching mechanism also limits the amount of working parts at the distal end of the device, which is generally inserted into hard to reach areas and, accordingly, is small in its overall size. 
     Referring now to FIGS. 4,  5   a  and  5   b  another alternative embodiment of the present invention is illustrated. In this embodiment, components and/or parts performing analogous or similar functions to those in FIGS. 1-3 are numbered in increments of  100 . Here communication of mixing chamber  112  with conduit  142  is limited by a shuttle  130 . Shuttle  130  is made of flexible material (such as plastic or metal) and is slidably positioned within tip  110  and is manipulated by the user at a convenient location remote to applicator tip  110 . 
     Shuttle  130  is configured to have an opening  140  which when it is in the position illustrated by FIG. 5 b  retrograde clearing, as previously discussed, of mixing chamber  112  is possible. In the preferred embodiment, opening  140  is at least as large as the opening into mixing chamber  112 . However, opening  140  may be larger than the opening to mixing chamber  112 . After clearing coagulated sealant from mixing chamber  112 , shuttle  130  is then moved into the positioned illustrated by FIG. 5 a . Opening  140  of shuttle  130  is equipped with a pair of blades  141  positioned on either end of opening  140 . Thus, as shuttle moves from the positions depicted in FIGS. 5 a  and  5   b  any coagulated sealant is sheared off by blades  141  and suctioned out through conduit  142 . 
     To facilitate the movement of shuttle  130  back into the position illustrated by FIG. 5 a , a spring actuated trigger  150  (FIG. 14 a ) can be configured to manipulate the movement of shuttle  130 . Therefore, the user need only to release the trigger and shuttle  130  moves back into the position illustrated by FIG. 5 a.    
     Alternatively, the trigger movement of shuttle  130  may also be tied into the application of sealant  122  (application of sealants agents  118  and  120 ). In this variation the application of sealant  122  is caused by manipulating a trigger which simultaneously moves shuttle  130  into the position of FIG. 5 a . Thus, as the user releases the trigger, application of sealant  122  stops and shuttle  130  moves into the position of FIG. 5 b , and retrograde clearing is possible. 
     In addition, and as illustrated trigger  150  is remotely positioned with respect to applicator tip  10 . Accordingly, the release of sealants  18  and  20 , mixed sealant  22  and the retrograde clearing of tip  10  can be remotely controlled. 
     Moreover and as another alternative, a constant suction force can be applied to conduit  142  in the direction of arrow  135 . Thus, and as discussed above, as the user releases the trigger, application of sealant  122  stops and shuttle  130  automatically moves into the position of FIG. 5 b , and retrograde clearing is instantaneously initiated. 
     In summation, mixing chamber  112  is effectively blocked off from conduit  142  while conduits  114  and  116  are still in communication with mixing chamber  112 . In this position agents  118  and  120  can now be supplied to mixing chamber  112  via positive pressure from conduits  114  and  116 . This provides for turbulent mixing of the agents prior to application. 
     Referring now to FIGS. 6,  7   a ,  7   b  and  7   c , yet another alternative embodiment of the present invention is illustrated. In this embodiment, components and/or parts performing analogous or similar functions are numbered in multiples of 100. Here retrograde clearing of mixing chamber  212  is limited by a silicon tube  240 . 
     Silicon tube  240  is attached to a conduit  230  at one end and mixing chamber  212  at the other end. Conduit  230  is position within a second conduit  242  which is larger in diameter than conduit  230 . 
     The flexible nature of silicon tube  230  and the diameter of conduit  242  allows conduit  230  to be rotated in the direction indicated by arrow  234 . 
     Referring now to FIG. 7 b , in this position conduit  230  and silicon tube  240  allow for retrograde clearing of mixing chamber  212 . As conduit  230  is rotated, silicon tube  240  is twisted and conduit  230  is drawn closer to mixing chamber  212 . Ultimately, silicon tube  240  is twisted until communication from conduit  230  to mixing chamber  212  is cut off. In this position agents  218  and  220  can now be supplied to mixing chamber  212  via positive pressure from conduits  214  and  216  to provide for turbulent mixing of the same prior to application. 
     When silicon tube  240  is in the position illustrated by FIG. 7 b , conduits  214  and  216  are blocked off to prevent retrograde suction of sealant agents  218  and  220 . Such blocking can be facilitated through the pinching of conduits  2 l 4  and  216 . 
     Referring now to FIG. 7 c , the opposite end of shaft  232  is illustrated. Here conduit  230  extends outwardly from conduit  242  to provide for an extended surface to allow for the user to easily manipulate conduit  230 . 
     The twisting of conduit  230  will create a torsional moment that, when conduit  230  is released, will cause silicon tube  240  to return to its untwisted position. 
     Alternatively, and in order to assist the user, conduit  230  can be configured to have a locking mechanism, such as a ratchet and pawl retaining device, or the equivalent thereof, to maintain silicon tube  240  in its twisted position. 
     Referring now to FIGS. 8 a  and  8   b  yet another alternative embodiment of the present invention is illustrated. Here communication of mixing chamber  312  with conduit  342  is limited through the incorporation of a flap valve  330 . Flap valve  330  is preferably constructed out of a stiff material such as hardened plastic or metal and opens and closes by manipulation of an actuating arm  331 . The manipulation of actuating arm  331 , as indicated by arrow  334 , cause flap valve  330  to either open or close. Flap valve  330  is pivotally secured to the inner surface of conduit  342  through the use of a hinge or other equivalent mechanism. 
     Flap valve  330  is received into a recess in conduit  342  (as illustrated in FIG. 8 b ) when it is in its open position. The recessment of flap valve  330  assists in the unimpeded clearing of mixing chamber  312 . As discussed above, the manipulation of valve  330  can be associated with the application of sealant  22  (ie. use of a trigger mechanism). 
     In addition, the when flap valve  330  is in the position illustrated by FIG. 8 b , conduits  314  and  316  (not shown) are blocked off to prevent retrograde suction of sealant agents  318  and  320 . Such blocking can be facilitated through the pinching of conduits  314  and  316  that consummates with the actuation of flap valve  330 . 
     Alternatively, and as illustrated in FIGS. 9 a  and  9   b  conduit  342  can be a flexible silicone tube which is opened or closed through the use of a slidably secured shuttle  330 . Shuttle  330  is equipped with an opening or slit  340  that reduces in size and therefore constricts flexible conduit  342  until it is effectively blocked off (as illustrated in FIG. 9 a ). 
     Movement of shuttle  330  may be achieved through the manipulation of a trigger ergonomic to manipulation of the user. 
     Effective closure of conduits  314  and  316  is facilitated, as discussed above, to prevent suction of agents  318  and  320  while clots are being removed from mixing chamber  312 . 
     In yet another embodiment, tip  410  is provided with a dual action valve for blocking off of mixing chamber  412  from conduit  442 . In this embodiment conduit  442  is a flexible silicone tube, and accordingly, the walls are capable of being manipulated by a pair of hinged pinching arms  430 . As illustrated in FIG. 10 a , arms  430  are hinged to flex the walls of silicon tube  442  inwardly. Thus, as arms  430  move inwardly, silicon tube  442  is compressed to effectively seal mixing chamber  412  from conduit  442 . 
     Once released, the resilient nature of silicon tube  442  causes conduit  442  to returns to its un-constricted position. In this position, retrograde clearing of area  412  is possible (FIG. 10 b ). 
     Effective closure of conduits  414  and  416  is facilitated, as discussed above, to prevent suction of agents  418  and  420  while clots are being removed from mixing chamber  412 . 
     Alternatively, and as illustrated in FIGS. 11 a  and  11   b , conduit  442  is a silicon tube and the outer wall of conduit  442  is positioned within shaft  432  to also define the area of conduits  414  and  416 . Accordingly, the flexible wall of conduit  442  may be pinched outwardly by a pair of hinged arms  430  (FIG. 11 b ). In this position retrograde clearing of mixing chamber  412  is possible while also effectively blocking off conduits  414  and  416 . Thus, suction can be applied to mixing chamber  412  without also sucking the agents out of conduits  414  and  416 . 
     In addition, hinged arms  430  are also configured to block off conduit  442  from mixing chamber  412  (as illustrated in FIG. 11 a ). 
     Alternatively, and as illustrated in FIGS. 12 a  and  12   b , a pair of shuttles  430 , each having a nub  431  for pinching flexible conduits  414  and  416 , are positioned to allow for retrograde clearing while also pinching off conduits  414  and  416 . In this embodiment the ends of shuttles  430  are angularly configured to slide backward while also constricting flexible conduits  414  and  416 . 
     In yet another variation (FIGS. 13 a  and  13   b ), the communication of mixing chamber  412  and conduit  442  is regulated by a stop cock valve  430 . Valve  430  is configured to block off conduits  414  and  416  when it is in its open position. 
     The present invention provides a novel surgical method of applying a quick coagulating sealant to unexposed or internal biological surfaces, e.g. human or animal anatomical surfaces, that are remotely accessible while also providing for retrograde clearing of the application device. 
     Thus, a surgeon, or other user, can insert the applicator tip into a cavity in a subject, operate applicator to disperse sealant and to apply the sealant to desired locations in the subject cavity, withdraw the applicator and manipulate it to a clearing configuration, apply suction to clear away any clogs and, if desired, reinsert the applicator to apply further sealant. 
     Moreover, the user can remotely control the release of the sealant and/or the sealant components by way of the mechanical components illustrated and described in the instant application. 
     In addition, alternative embodiments of the present invention also allow for the applicator to be manipulated to a clearing configuration without having to remove the applicator tip. 
     While illustrative embodiments of the invention have been described above, it is, of course, understood that various modifications will be apparent to those of ordinary skill in the art. Such modifications are contemplated as being within the spirit and scope of the present invention which is limited and defined only by the appended claims.