Patent Publication Number: US-2012046689-A1

Title: Wound Closure Material Applicator

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 10/513,434, filed Nov. 1, 2004, which is a National Stage entry under 35 U.S.C. §371(a) of International Application No. PCT/US03/16064, filed May 16, 2003, which claims the benefit of, and priority to, U.S. Provisional Patent Application Ser. No. 60/381,435, filed May 17, 2002, now expired, the entire contents of each application being incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an applicator for applying a fluid material onto a surface. More specifically, the present disclosure relates to an applicator for applying a wound closure material onto tissue for wound repair. 
     2. Background of Related Art 
     Applicators for applying wound closure materials, for example, adhesives, sealants and hemostats, to tissue to effect wound repair are well known in the art. Typically, such applicators include a tube or syringe and a plunger or driver which is advanceable through the syringe to force the wound closure material from the syringe. Such a device is disclosed in U.S. Pat. No. 6,027,471. In such devices, the distal end of the syringe is open and the wound closure material is retained within the syringe by surface adhesion of the wound closure material to the internal walls of the syringe. After the wound closure material is dispensed from the syringe, drippage of the wound closure material from the distal end of the syringe is common. Due to the location of use of wound closure material applicators, e.g., body cavities, body tissue, etc., such drippage is undesirable. 
     Accordingly, a need exists for a wound closure material applicator which is easy to operate, minimizes drippage and provides a more controlled application of the material to tissue. 
     SUMMARY 
     In accordance with one preferred embodiment of the present disclosure, a wound closure material applicator is provided which includes a handle assembly having a movable handle or trigger and a stationary handle. A body portion extends distally from the handle assembly and defines a body channel dimensioned to receive wound closure material or a reservoir of wound closure material. A tip assembly is supported adjacent the distal end of the body portion and includes a seal member, a valve seat and a discharge channel positioned distally of the valve seal The seal member is movable distally within the tip assembly from a closed position in which the seal member engages the valve seat to an open position in which the seal member is spaced from the valve seat. The tip assembly is configured such that movement of the seal member from the open position to the closed position causes a reduction of pressure within the discharge channel of the tip assembly to minimize drippage of wound closure material from the applicator. Preferably, the seal member is urged toward the closed position by a biasing member. 
     Preferably, the tip assembly also includes a housing which defines an inlet channel and the valve seat, the valve seat being positioned adjacent the inlet channel. The seal member may include a spherical valve member positioned to engage the valve seat which can be formed integrally with or separately from the seal member. The seal member can also be configured to define the discharge channel. The tip assembly can also include a tip member having a concave or spherical receptacle which communicates with the discharge channel. One or a plurality of inlet ports may be formed in the seal member to communicate with the discharge channel. Preferably, the seal member includes an annular resilient finger which is positioned to engage a wall defining a bore in the tip assembly housing and provides a seal between the bore and the seal member. A feed bar can be provided within the body portion which is operatively associated with the movable handle such that actuation of the movable handle effects distal movement of the feed bar within the body portion. A pusher may be supported or integrally formed on a distal end of the feed bar. In a preferred embodiment, a drive plate provided in the handle assembly is driven into engagement with the feed bar by the movable handle to move the feed bar distally. A movable locking plate may also be provided in the handle assembly for permitting movement of the feed bar in a first position and for engaging and preventing proximal movement of the feed bar in a second position. Preferably, the locking member is urged to the second position by a biasing member. 
     In another preferred embodiment of the present disclosure, the tip assembly includes a housing, a tip member, and a permeable membrane. The permeable membrane is supported over the open end of a tip housing bore. In use, wound closure material is forced into the bore of the tip housing and passes through the permeable membrane into a spherical recess formed in the tip member. The presently disclosed wound closure material applicators provide a more controlled application of wound closure material onto a surface by minimizing dripping of the material from the applicator. 
     The wound closure material applicator can be used to dispense wound closure materials including adhesives, sealants and hemostats. One preferred adhesive is a cyanoacrylate adhesive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various preferred embodiments of the presently disclosed wound closure material applicator are described herein with reference to the drawings wherein: 
         FIG. 1  is a top view of one preferred embodiment of the presently disclosed wound closure material applicator; 
         FIG. 2  is a side view of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 3  is a side view of the proximal portion of the wound closure material applicator shown in  FIG. 1  including the handle assembly with a body half-section removed; 
         FIG. 4  is a front view of the drive plate of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 5  is a side cross-sectional view of the drive plate shown in  FIG. 4 ; 
         FIG. 6  is a side view of a feed bar guide member of the wound closure material applicator shown in  FIG. 3 ; 
         FIG. 7  is a front view of the feed bar guide member shown in  FIG. 6 ; 
         FIG. 8  is a side partial cross-sectional view of the guide member shown in  FIG. 6 ; 
         FIG. 9  is a side view of the feed bar of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 10  is a cross-sectional view taken along section lines  10 - 10  of  FIG. 9 ; 
         FIG. 11  is a front view of the locking member of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 12  is a cross-sectional view taken along section lines  12 - 12  of  FIG. 11 ; 
         FIG. 13  is a cross-sectional cutaway view of the distal end of the locking member of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 14  is a top view of the distal portion of the wound closure material applicator shown in  FIG. 1  with the outer tube removed; 
         FIG. 15  is a side view of the distal portion of the wound closure material applicator shown in  FIG. 14 ; 
         FIG. 15A  is a side cross-sectional view of the central portion of the wound closure material applicator shown in  FIG. 1  with the pusher in a retracted position; 
         FIG. 15B  is a side cross-sectional view of the distal portion of the wound closure material applicator shown in  FIG. 1  with the pusher in an advanced position; 
         FIG. 16  is a top view with portions broken away of the outer tube of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 17  is a top view of the inner tube of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 18  is a side view of the inner tube shown in  FIG. 17 ; 
         FIG. 18   a  is a cross-sectional view taken along section lines  18   a - 18   a  of  FIG. 18 ; 
         FIG. 19  is a front view of the inner tube shown in  FIG. 17 ; 
         FIG. 20  is a side cross-sectional view of the tip assembly of the wound closure material applicator shown in  FIG. 1 ; 
         FIG. 20A  is a side perspective view from the rear of the seal member of the tip assembly shown in  FIG. 20 ; 
         FIG. 20B  is a cross-sectional cutaway view of the proximal end of the seal member shown in  FIG. 20   a;    
         FIG. 21  is a side view of another preferred embodiment of the presently disclosed wound closure material applicator with a handle assembly body half-section removed; 
         FIG. 22  is a top view of the wound closure material applicator shown in  FIG. 21 ; 
         FIG. 23  is a side view of the proximal portion of the wound closure material applicator shown in  FIG. 21  including the handle assembly with a body half-section removed; 
         FIG. 24  is a side cross-sectional view of the wound closure material applicator shown in  FIG. 21  with the body half-sections of the handle assembly removed; 
         FIG. 25  is a side view with portions broken away of the feed bar of the wound closure material applicator shown in  FIG. 21 ; 
         FIG. 26  is a cross-sectional view taken along section lines  26 - 26  of  FIG. 25 ; 
         FIG. 27  is a side view with portions broken away of the pusher of the wound closure material applicator shown in  FIG. 21 ; 
         FIG. 28  is a top view with portions broken away of the pusher shown in  FIG. 27 ; 
         FIG. 29  is a side perspective view of the piston of the wound closure material applicator shown in  FIG. 21 ; 
         FIG. 30  is a side partial cross-sectional view of the piston shown in  FIG. 29 ; 
         FIG. 31  is a side cross-sectional view of a distal portion of the wound closure material applicator shown in  FIG. 21 ; 
         FIG. 31A  is a side cross-sectional view of the tip assembly shown in  FIG. 31  supported in the inner and outer tubes; 
         FIG. 32  is a side perspective view of the housing of the tip assembly shown in  FIG. 31 ; 
         FIG. 33  is a side cross-sectional view of the housing shown in  FIG. 32 ; 
         FIG. 34  is a side perspective view of the tip member of the tip assembly shown in  FIG. 31 ; 
         FIG. 35  is a side cross-sectional view of the tip member shown in  FIG. 34 ; 
         FIG. 36  is a side perspective view of the seal member of the tip assembly shown in  FIG. 31 ; 
         FIG. 37  is a side cross-sectional view of the seal member shown  FIG. 36 ; 
         FIG. 38  is a side cross-sectional view of the proximal end of the seal member shown in  FIG. 36 ; 
         FIG. 39  is a side cross-sectional view with portions broken away of the distal portion of another preferred embodiment of the presently disclosed wound closure material applicator; 
         FIG. 40  is an enlarged cross-sectional view with portions broken away of the encircled distal portion of the tip assembly of the wound closure material applicator shown in  FIG. 39 ; 
         FIG. 41  is a side perspective view of the tip member of another preferred embodiment of the presently disclosed wound closure material applicator; 
         FIG. 42  is a side partial cross-sectional view of the tip assembly shown in  FIG. 42 ; and 
         FIG. 43  is a side cross-sectional view of the tip member of another preferred embodiment of the wound closure material applicator. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the presently disclosed wound closure material applicator will now be described in detail with reference to the drawings, wherein like reference numerals designate identical or corresponding elements in each of the several views: 
       FIGS. 1 and 2  illustrate one embodiment of the presently disclosed wound closure material applicator shown generally as  10 . Wound closure material applicator  10  includes a handle assembly  12 , an elongated body portion  14  and a distally positioned tip assembly  16 . Handle assembly  12  includes a barrel portion  18 , a stationary handle portion  20 , a movable handle portion or trigger  22  and a locking member  24 . Handle portions  20  and  22  include finger loops  20   a  and  22   a,  respectively, which facilitate gripping of the instrument. Body portion  14  has a proximal end secured to handle assembly  14  and a distal end supporting tip assembly  16 . 
     Referring to  FIG. 3 , handle assembly  12  includes a body  26  formed from body half-sections  26   a  and  26   b  ( FIG. 1 ), which are preferably molded from a polycarbonate or other plastic material. Alternately, other materials may be used to form body half-sections  26   a  and  26   b,  e.g., stainless steel, etc. Trigger  22  is pivotally supported about a pivot member  28  which is supported between body half-sections  26   a  and  26   b.  Trigger  22  is pivotal in the direction indicated by arrow “A” towards stationary handle portion  20 . A drive plate  32  ( FIGS. 4 and 5 ) includes a slotted opening  34  dimensioned to receive a feed bar  36  which is slidably positioned within body  26  and elongated body portion  14 . A pair of feed bar guide members  38  ( FIGS. 6-8 ) are supported at spaced locations between half-sections  26   a  and  26   b.  Each guide member  38  includes a slot  38   a  for slidably receiving feed bar  36 . 
     A biasing member  40 , which is preferably a torsion spring, is positioned about feed bar  36  between the forward most guide member  38  and drive plate  32 . Biasing member  40  is positioned to urge drive plate  32  proximally into engagement with trigger  22  to urge trigger  22  in a counter-clockwise direction as shown in  FIG. 3  to a (non-compressed) position spaced from stationary handle portion  20 . Trigger  22  includes a flat face  44  against which drive plate  32  abuts. 
     Referring also to  FIGS. 9 and 10 , feed bar  36  preferably includes a flat elongated member having a substantially rectangular cross-section with radiused top and bottom edges. Alternately, other feed bar configurations are envisioned, e.g., cylindrical, triangular, square, etc. Feed bar  36  extends through the proximal and distal ends of barrel portion  18  of handle assembly  12 . The distal end of feed bar  36  extends into elongated body portion  14 . As discussed above, feed bar  36  is slidably supported within barrel portion  18  of handle assembly  12  by guide members  38 . See  FIG. 3 . The proximal end of feed bar  36  extends rearwardly from barrel portion  18  and includes a knob or grip  50  secured to the proximal end thereof. Knob  50  is configured to be grasped by a surgeon such that feed bar  36  can be returned to a retracted position. Knob  50  also functions as a stop to limit distal advancement of feed bar  36 . 
     Locking member  24  is pivotally supported within the distal end of barrel portion  18  of handle assembly  12  and includes an elongated slot  52  ( FIGS. 11 and 12 ) dimensioned to slidably receive feed bar  36 . A biasing member  56 , which is preferably a torsion spring, is positioned to urge locking member  24  from a substantially vertical orientation in which slot  52  is aligned with feed bar  36  to allow feed bar  36  to slide in relation thereto to a canted orientation in which the top and/or bottom edges defining slot  52  engage feed bar  36  to prevent proximal movement of feed bar  36  in relation to locking member  24 . Because of the angle of locking member  24  in relation to feed bar  36  in its canted position, locking member  24  permits distal advancement of feed bar  36  when trigger  22  is actuated. The top surface of feed bar  36  may be roughened, e.g., serrated, scarred, knurled, etc., to enhance contact between locking member  24  and feed bar  36 . 
     Referring to  FIGS. 13-15 , the distal end of feed bar  36  is secured to the proximal end of a pusher  62  in a known manner, e.g., welding, brazing, screws, etc. Alternately, feed bar  36  and pusher  62  may be monolithically formed. The distal end of pusher  62  includes a cavity  64  configured and dimensioned to receive a drive member  66  ( FIGS. 14 and 15 ). Drive member  66  preferably has a spherical configuration and is made of non-stick material such as a synthetic fluorine containing resin, e.g., Teflon™ or formed of another material, e.g., plastic, metal, etc., that has a non-stick outer surface, layer or covering. Alternately, drive members having different configurations are envisioned, e.g., cylindrical, rectangular, convex, concave, etc. Preferably, drive member  66  is not physically attached to pusher  66 . Alternately, drive member  66  can be monolithically formed with pusher  62  or fastened to pusher  36  within cavity  64  using any known technique including welding, brazing, adhesives, etc. 
     Referring to  FIGS. 1-3  and  14 - 16 , elongated body  14  includes an inner tube  68 , a wound closure material reservoir  70 , a pusher guide  72  and an outer tube  76 . Reservoir  70  is preferably a tube having two open ends. Reservoir  70  can, for example be a capillary tube or cartridge. Alternately, reservoir  70  may be formed from a flexible, deformable or compressible material having an open distal end and a sealed proximal end  70   b.  The sealed proximal end  70   a  may be pinch sealed between inner and outer tubes  68  and  76 , respectively, to permit drive member  66  to pass over the proximal end of the outer surface of reservoir  70  to force wound closure material from distal end  70   b  of reservoir  70 . See  FIG. 15A . Open distal end  70   b  of reservoir  70  may be positioned about the proximal end  78   a  of housing  78  of tip assembly  16  within inner tube  68 . See  FIG. 15B . Such a reservoir can be deformed by direct contact of drive member  66  with reservoir  70  to dispense material. Preferably, distal end  70   b  of reservoir  70  is fastened about the proximal end  78   a  of tip assembly  16  such as by crimping, press-fitting, adhesives, etc. Alternately, other fastening techniques may be used. 
     Inner tube  68  includes an elongated opening  74  formed therein. (See  FIGS. 17-19 ). Opening  74  is dimensioned to receive or allow passage of reservoir  70  during assembly of applicator  10 . The distal end of inner tube  68  is fastened about proximal end  78   a  of tip assembly  16  and the distal end of reservoir  70 . The proximal end of inner tube  68  is fastened about pusher guide  72 . Referring to  FIGS. 1-3  and  16 , an outer tube  76  extends between handle assembly  12  and tip assembly  16  to axially fix handle assembly  12  and tip assembly  16  in relation to each other and confine inner tube  68  and reservoir  70  therein. 
     Referring to  FIGS. 20-20   b,  tip assembly  16  includes housing  78 , a tip member  80 , a valve member  82 , a seal member  84  and a biasing member  86 . Housing  78  includes a proximal end defining an inlet channel  88  which converges towards valve member  82  and a distal end defining a hollow bore  90 . Alternately, channel  88  may include other configurations, e.g., cylindrical, diverging, etc. An internal wall of housing  78  adjacent inlet channel  88  defines a valve seat  82   a.  Tip member  80  is fixedly received within bore  90  of housing  78  using press-fitting, adhesives, welding, brazing, etc. The distal end of tip member  80  includes a spherical or concave receptacle  92  which will be discussed in detail below and an angled distal face  80   a.  Angled face  80   a  defines an angle Θ with respect to an axis perpendicular to the longitudinal axis of the applicator of between about 10° and about 45° and preferably about 15°. The proximal end of tip member  80  has a reduced outer diameter defining a step or shoulder  94 . Seal member  84  is slidably positioned within tip member  80  and includes an elongated central discharge channel  96  having a distal end  96   a  located adjacent receptacle  92  of tip member  80  and a proximal end  96   b  defining a recess having a plurality of inlet ports  84   a  Seal member  84  and valve member  82  can be integrally formed or formed separately. The wall defining central discharge channel  96  is preferably coated with a non-stick material such as a synthetic fluorine containing resin, e.g., Teflon™. Valve member  82  may also include a non-stick coating. Seal member  84  also includes a shoulder  84   b  and a resilient annular, outwardly diverging finger  84   c.  Biasing member  86 , which is preferably a torsion spring, is positioned between shoulder  94  of tip member  80  and shoulder  84   b  of seal  84  to urge seal member  84  including valve member  82  into sealing contact with valve seat  82   a  of housing  78 . 
     Referring to  FIGS. 3 ,  15  and  20 , when trigger  22  is pivoted about pivot member  28  in the direction indicated by arrow “A” in  FIG. 3 , drive plate  32  is tilted into engagement with feed bar  36  and moved forwardly in the direction indicated by arrow “B” in  FIG. 3  to effect distal advancement of feed bar  36 . As feed bar  36  is advanced distally in the direction indicated by arrow “C” in  FIG. 15 , drive member  66  is also advanced distally into and through reservoir  70  to force wound closure material to flow into inlet channel  88  of tip assembly seal member  84 . As trigger  22  is pivoted further, the fluid pressure of the wound closure material within channel  88  increases until the force applied by spring  86  on valve member  82  is overcome and valve member  82  is lifted off of valve seat  82   a.  When this occurs, valve member  82  advances seal member  84  distally against the bias of spring member  86  such that the distal end of seal member  84  is positioned adjacent to or extends into receptacle  92  of tip assembly  16 . Thereafter, wound closure material flows around valve member  82  through channels  84   a  in seal member  84  into central channel  96  of seal member  84  into receptacle  92  of tip assembly  16  and can be dispensed on tissue. Referring again to  FIG. 3 , when a surgeon releases trigger  22 , biasing member  40  urges trigger  22  to pivot in the direction indicated by arrow “D” to its non-compressed position to disengage drive plate  32  from feed bar  36 . Locking member  24  remains in engagement with feed bar  36  to prevent retraction of feed bar  36 . In order to retract feed bar  36 , locking member  24  is moved against the bias of spring  56  to its vertical position disengaged from feed bar  36  and knob  50  is pulled proximally. Trigger  22  can be actuated multiple times to dispense the required amount of wound closure material. 
     After a sufficient amount of wound closure material has been dispensed and trigger  22  is released by a surgeon, spring  86  will return valve member  82  onto valve seat  82   a.  Movement of valve member  82  proximally back onto valve seat  82   a  draws a vacuum within central discharge channel  96  of seal member  84  to draw some of the wound closure material within receptacle  92  of tip  80  back into central discharge channel  96  to minimize the amount of drippage from the instrument 
       FIGS. 21-23  illustrate another preferred embodiment of the presently disclosed wound closure material applicator shown generally as  100 . Wound closure material applicator  100  includes a handle assembly  112 , an elongated body portion  114 , and a tip assembly  116  supported on the distal end of elongated body portion  114 . Handle assembly  112  is similar to handle assembly  12  and will only be discussed in detail to the extent necessary to identify differences in construction and operation. 
     Handle assembly  112  includes a stationary handle portion  120 , a movable handle portion or trigger  122 , and a locking member  124 . Trigger  122  is pivotally supported between body half-sections  126   a  (only one half-section is shown) about a pivot member  128  and is in operative engagement with a drive plate  132 . A biasing member  140  is positioned to urge drive plate  132  and trigger  122  to a rearward or non-compressed position. Trigger  122 , drive plate  132  and biasing member  140  are associated with feed bar  136  and operate in a manner substantially similar to trigger  22 , drive plate  32  and biasing member  40  of applicator  10  described above and will not be discussed in further detail herein. 
     Handle assembly  112  includes a locking member  124  which is pivotally supported in the distal end of barrel portion  118  of handle assembly  112  and a biasing member  156  which urges locking member  124  into a canted position engaged with feed bar  136 . Although the location of locking member  124  and biasing member  156  has changed slightly compared to that of locking member  24  and biasing member  56  described above, the operation and function of locking member  24  is identical to that described above and will not be described in further detail herein. 
     Referring to  FIGS. 24-26 , feed bar  136  preferably includes a flat elongated member having a substantially rectangular cross-section with radiused top and bottom edges. Alternately as discussed above, other configurations are envisioned. The proximal and distal ends of feed bar  136  preferably include throughbores  142   a  and  142   b,  respectively, dimensioned to receive screws or pins. The proximal end of feed bar  136  is secured to knob  150  and the distal end of feed bar  136  is secured to pusher  162 . 
     Referring also to  FIGS. 27 and 28 , pusher  162  is preferably substantially cylindrical and includes a proximal end having a transverse slot  162   a  configured and dimensioned to receive the distal end of feed bar  136 . A throughbore  162   b  formed in the proximal end of pusher  162  is dimensioned to receive a screw or pin  162   c  for securing feed bar  136  to pusher  162 . Alternately other fastening techniques, such as welding, brazing, crimping, etc., may be sued to secure the feed bar  136  to the pusher. 
     Referring to FIGS.  24  and  29 - 31 , a piston  166  is secured to the distal end of pusher  162 . Piston  166  has a bore  166   a  formed in a proximal end thereof. Bore  166   a  is dimensioned to receive a reduced diameter portion  162   d  of pusher  162 . Pusher  162  is secured within bore  166   a  of piston  166  using any known fastening technique including press-fitting, screws, pins, welding, etc. Alternately, piston  166  and pusher  162  can be monolithically formed. The distal end of piston  166  is cylindrical and corresponds in shape to the internal wall of wound closure material reservoir  170 . 
     Referring to  FIGS. 31 and 31A , elongated body  114  includes an inner tube  170  defining a body channel and an outer tube  176  Inner tube  170  includes a supply of wound closure material (not shown) which may be in the form of a cartridge of material or material located directly in the channel. The distal end of inner tube  170  is fixedly positioned about the proximal end of housing  178  of tip assembly  116 . Outer tube  176  extends between handle assembly  112  and tip assembly  116  and encloses elongated body  114  and tip assembly  116 . The distal end of outer tube  176  includes spring tabs  176   a  which are received in recesses  178   a  formed in housing  178  of tip assembly  116  and axially secure tip assembly  116  within outer tube  116   a.    
     Tip assembly  116  includes a housing  178 , a tip member  180 , a valve member  182 , a seal member  184  and a biasing member  186 . Housing  178  includes a proximal end defining an inlet channel  188  which includes a convergent, reduced diameter section  188   a  which extends towards valve member  182  and a distal end defining a hollow bore  190 . See  FIGS. 32 and 33 . A central portion of housing  178  defines a valve seat  178   a.  Tip member  180  is fixedly received within bore  190  of housing  178 . The distal end of tip member  180  includes a spherical receptacle  192  which will be discussed in detail below. See  FIGS. 34 and 35 . The proximal end of tip member  180  has a reduced outer diameter defining a step or shoulder  194 . Seal member  184  is slidably positioned within tip member  180  and includes an elongated central discharge channel  196  having a distal end  196   a  located adjacent receptacle  192  of tip member  180  and a proximal end  196   b  defining a recess having a plurality of inlet ports  184   a  ( FIG. 38 ) which communicate with discharge channel  196 . The wall defining central channel  196  is preferably coated with a non-stick synthetic fluorine containing, e.g., Teflon™. Seal member  184  also includes a shoulder  184   b.  Biasing member  186 , which is preferably a torsion spring, is positioned between shoulder  194  of housing  178  and shoulder  184   b  of seal member  184  to urge seal member  184  into sealing contact with valve seat  178   a  of housing  178 . 
     In use, when trigger  122  is pivoted about pivot member  128  ( FIG. 21 ), drive plate  132  is tilted into engagement with feed bar  136  and moved forwardly to effect distal advancement of feed bar  136 . As feed bar  136  is advanced distally, pusher  162  and drive member  166  are advanced distally through inner tube or reservoir  170  to force wound closure material to flow into inlet channel  188  of housing  178 . As trigger  22  is pivoted further, the fluid pressure of the wound closure material within channel  188  increases until the force applied by spring  186  on valve member  182  is overcome and valve member  182  lifts off of valve seat  178   a.  When this occurs, wound closure material flows around valve member  182  through ports  184   a  in seal member  184  into central discharge channel  196  of seal member  184  and into receptacle  192  of tip assembly  116 . Thereafter, wound closure material can be dispensed on tissue. As discussed above with respect to wound closure material applicator  10 , when trigger  122  is released and the pressure of wound closure material in channel  188  is reduced, valve member  182  is urged into contact with valve seat  178   a  to seal inlet channel  188 . As valve member  182  is moved towards valve seat  178   a,  a vacuum is created in center discharge channel  196  of seal member  184  which draws wound closure material positioned in spherical receptacle  192  into central channel  196  to minimize dripping of wound closure material from tip assembly  116 . 
       FIGS. 39 and 40  illustrate another preferred embodiment of the tip assembly shown generally as  216 . Tip assembly  216  includes a housing  278 , a tip member  280 , an insert member  282  and a permeable membrane  284 . The proximal end of housing  278  is fixedly received within the distal end of a wound closure material reservoir  270  in a manner similar to that disclosed above. Tip member  280  is fixedly received within the distal end of housing  278 . Preferably, protrusions  280   a  are formed on an outer surface of tip member  280  and are received within concavities  278   a  formed on an inner wall of housing  278  to secure tip member  280  to tip housing  278 . Alternately, other known securement means may be used to secure tip member  280  to housing  278 , e.g., press-fitting, crimping, adhesives, etc. 
     Insert member  282  includes an annular ring having a proximally extending tapered portion  282   a  and a distally located increased diameter portion  282   b.  Tip member  280  includes an annular recess  280   b  configured to receive tapered portion  282   a  of insert member  282  and a radial cutout  280   c  configured to receive increased diameter portion  282   b  of insert member  282 . Insert member  282  is received within tip member  280  to secure permeable membrane  284  between a front face of tip member  280  and a proximal surface, e.g.,  282   a,  of insert member  282 . 
     Tip member  280  may be substituted for the tip assemblies discussed above with reference to wound closure material applicators  10  and  100 . In use, when piston  266  is advanced distally through reservoir  270 , wound closure material is forced from reservoir  270  into bore  290  of tip housing  278  and bore  281  of tip member  280  into contact with on interior side  284   a  of permeable membrane  284 . As piston  266  is advanced and the pressure of the wound closure material within bore  281  increases, the wound closure material will pass from interior side  284   a  through permeable membrane  284  to exterior side  284   b  into receptacle  292  at the distal end of tip member  280 . Thereafter, the wound closure material can be dispensed on tissue by the surgeon. 
       FIGS. 41 and 42  illustrate yet another preferred embodiment of the tip assembly shown generally as  316 . Tip assembly  316  includes a tip housing  378  having a central throughbore  390 . The proximal end of tip housing  378  includes a reduced diameter portion  378   a  which is configured and dimensioned to be fixedly received within the distal end of a wound closure material reservoir (such as reservoir  170 ,  FIG. 31A ). The outer surface of tip housing  378  also includes one or more recesses for engaging the outer housing of a wound closure material applicator. Tip assembly  316  is suitable for use with wound closure material applicators having a more viscous wound closure material than are tip assemblies  16 ,  116  and  216  disclosed above. 
     It is understood that would closure materials include but are not limited to adhesives, hemostats and sealants. Adhesives function to attach or hold organs, tissues or structures, sealants to prevent fluid leakage, and hemostats to halt or prevent bleeding. Examples of adhesives which can be employed include protein derived, aldehyde-based adhesive materials, for example, the commercially available albumin/glutaraldehyde materials sold under the trade designation BioGlue™ by Cryolife, Inc., and cyanoacrylate-based materials sold under the trade designations Indermil™ and Derma Bond™ by Tyco Healthcare Group, LP and Ethicon Endosurgery, Inc., respectively. Examples of sealants which can be employed include fibrin sealants and collagen-based and synthetic polymer-based tissue sealants. Examples of commercially available sealants are synthetic polyethylene glycolbased, hydrogel materials sold under the trade designation CoSeal™ by Cohesion Technologies and Baxter International, Inc. Examples of hemostat materials which can be employed include fibrin-based, collagen-based, oxidized regenerated cellulose-based and gelatin-based topical hemostats herein can include astringents and coagulants. Examples of commercially available hemostat materials are fibrinogen-thrombin combination materials under sold the trade designations CoStasis™ by Tyco Healthcare Group, LP and Tisseel™ sold by Baxter International, Inc. Hemostats herein include astringents, e.g., sulphates of aluminum, and coagulants. 
     It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the tip housing may define a converging throughbore  490 . See  FIG. 43 . The applicator may be constructed from any material or materials suitable for surgical use including metals, stainless steel, plastics, polymeric materials, PTFE, etc. Any part or all of the applicator may be formed so as to be disposable. For example, the elongated body and/or tip assembly may be in the form of a replaceable and disposable unit. Although, especially suitable for dispensing wound closure material to apply mesh to tissue during a surgery for hernia repair, the wound closure material applicator may be used in a variety of surgical procedures requiring wound closure materials. Further, the above-described applicator may also be suitable for dispensing materials other than wound closure materials in surgical and non-surgical applications. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.