Abstract:
An adapter assembly for connecting an end effector to a surgical instrument includes first and second drive assemblies configured for converting rotational motion into linear motion, and an actuation assembly. The second drive assembly includes a pair of push/pull cables for longitudinally advancing and retracting a drive member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/251,300 filed Nov. 5, 2015, the entire disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates generally to powered surgical devices. More specifically, the present disclosure relates to adapter assemblies for selectively connecting end effectors to actuation units of powered surgical devices. 
         [0004]    2. Background of Related Art 
         [0005]    Powered devices for use in surgical procedures typically convert rotational motion from a handle assembly to linear motion for effectuating one or more functions, e.g., clamping, stapling, cutting. To permit reuse of the handle assemblies of these powered surgical devices and so that the handle assembly may be used with a variety of end effectors, adapter assemblies have been developed for selective attachment to the handle assemblies and to a variety of end effectors. Following use, the adapter assembly may be disposed of along with the end effector. 
         [0006]    It has been discovered that a need exists for an adapter assembly having a flexible or more flexible body portion, as compared to prior adapter assemblies having rigid or relatively more rigid body portions thereof. 
       SUMMARY 
       [0007]    An adapter assembly for operably connecting an end effector to a powered surgical instrument is provided. The adapter assembly includes a drive coupling assembly, a first drive assembly, a second drive assembly, and an actuation assembly. The first drive assembly is operably connected to the drive coupling assembly and includes a first push/pull cable. The second drive assembly is operably connected to the drive coupling assembly and includes second and third push/pull cables. The actuation assembly includes a first pusher member. Retraction of the second and third push/pull cables effects advancement of the first pusher member. 
         [0008]    In embodiments, the adapter assembly further includes a third drive assembly operably connected to the drive coupling assembly. The third drive assembly includes at least fourth and fifth push/pull cables. The actuation assembly may include a second pusher member. Retraction of the fourth and fifth push/pull cables may effect advancement of the second pusher member. The adapter assembly may further include a trocar member. The first push/pull cable may be secured to the trocar member. Each of the second and third push/pull cables and the fourth and fifth push/pull cables may include a corresponding sheath. The second, third, fourth, and fifth push/pull cables and the corresponding sheaths may each include service slack. Each of the second and third push/pull cables may be secured to a first pair of guide members and the fourth and fifth push/pull cables may be secured to a second pair of guide members. 
         [0009]    The actuation assembly may include a cylindrical housing. Each guide member of the first and second pairs of guide members may be secured relative to the cylindrical housing. Each of the first, second, and third drive assemblies may include a transmission for converting high speed, low torque input to low speed, high torque output. 
         [0010]    The coupling assembly may connect each of the first, second, and third drive assemblies with respective first, second, and third drive shafts of a handle assembly. The first drive assembly may include a first carriage assembly and the second drive assembly may include a second carriage assembly. The first push/pull cable may be secured to the first carriage assembly and the second and third push/pull cables may be secured to the second carriage assembly. The third drive assembly may include a third carriage assembly. The fourth and fifth push/pull cables may be secured to the third carriage assembly. 
         [0011]    In embodiments, the adapter assembly further includes a trocar assembly. The trocar assembly may include a locking member and a releasable trocar member. The releasable trocar member may be configured for operable engagement with an anvil assembly. 
         [0012]    Also provided is a surgical assembly for connection to and operation by a handheld electromechanical instrument. The surgical assembly includes a trocar assembly and an adapter assembly. The trocar assembly includes a locking member, and a trocar member releasably secured to the locking member. The adapter assembly is configured to be releasably secured to a handheld electromechanical instrument and includes a first drive cable. The locking member of the trocar assembly is secured to the first drive cable and is movable between a first position where the trocar member is releasable from the locking member and a second position were the trocar member is secured to the locking member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Embodiments of the present disclosure are described herein with reference to the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a perspective view of an adapter assembly, in accordance with an embodiment of the present disclosure, an exemplary handle assembly, and an exemplary tool assembly; 
           [0015]      FIG. 2  is a perspective view of the adapter assembly of  FIG. 1  including the exemplary tool assembly, with an outer sleeve removed; 
           [0016]      FIG. 3  is a perspective end view of a proximal end of the adapter assembly of  FIG. 1 ; 
           [0017]      FIG. 4  is a perspective view of a distal end of the adapter assembly of  FIG. 1 , including the exemplary tool assembly; 
           [0018]      FIG. 5  is a perspective end view of the proximal end of the adapter assembly of  FIG. 3 , with an outer housing removed; 
           [0019]      FIG. 6  is another perspective view of the proximal end of the adapter assembly of  FIG. 3 ; 
           [0020]      FIG. 7  is a perspective end view of the proximal end of the adapter assembly of  FIG. 3 , with the outer housing and an inner housing removed; 
           [0021]      FIG. 8  is another perspective view of the proximal end of the adapter assembly of  FIG. 7 ; 
           [0022]      FIG. 9  is a cross-sectional perspective end view of the proximal end of the adapter assembly of  FIG. 8 , taken along section line  9 - 9 ; 
           [0023]      FIG. 10  is a side perspective view of the distal end of the adapter assembly shown in  FIG. 4 , with the outer sleeve removed; 
           [0024]      FIG. 11  is a side perspective view of a pair of push/pull cables having a wave configuration; 
           [0025]      FIG. 12  is a side perspective view of a push/pull cable having a looped configuration; 
           [0026]      FIG. 13  is a side cross-sectional perspective view of a distal end of the adapter assembly of  FIG. 1 ; 
           [0027]      FIG. 14  is an enlarged view of the indicated area of detail in  FIG. 13 ; 
           [0028]      FIG. 15  is a perspective view of an actuation assembly of the adapter assembly of  FIG. 1 , with a housing, and first and second pusher members removed; 
           [0029]      FIG. 16  is a side perspective view of the actuation assembly of the adapter assembly of  FIG. 15 , including the first and second pusher members in their first or proximal positions; 
           [0030]      FIG. 17  is a side perspective view of the actuation assembly of the adapter assembly of  FIG. 15 , including the second pusher member; 
           [0031]      FIG. 18  is a side perspective view of a locking member and a trocar member of a trocar assembly of the adapter assembly of  FIG. 1 , with parts separated; 
           [0032]      FIG. 19  is a cross-sectional side view of the actuation assembly of the adapter assembly of  FIG. 15 , with the trocar assembly in an extended condition; 
           [0033]      FIG. 20  is a cross-sectional side view of the actuation assembly of  FIG. 19 , with the trocar assembly in a retracted position; 
           [0034]      FIG. 21  is a cross-sectional side view of the actuation assembly of  FIG. 19  and the anvil assembly of  FIG. 1 , with the second pusher member in a first distal position; 
           [0035]      FIG. 22  is a cross-sectional side view of the actuation assembly of  FIG. 19 , with the first pusher member in its distal-most position; and 
           [0036]      FIG. 23  is a cross-sectional side view of the actuation assembly of  FIG. 19 , with the first and second pusher members in their distal-most position. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0037]    Embodiments of the presently disclosed adapter assembly for surgical devices and/or handle assemblies are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the adapter assembly or surgical device, or component thereof, farther from the user, while the term “proximal” refers to that portion of the adapter assembly or surgical device, or component thereof, closer to the user. 
         [0038]    With reference to  FIGS. 1 and 2 , an adapter assembly in accordance with an embodiment of the present disclosure, shown generally as adapter assembly  100 , is configured for selective connection to a powered handheld electromechanical instrument shown, generally as handle assembly  20 . As illustrated in  FIG. 1 , the handle assembly  20  is configured for selective connection with the adapter assembly  100 , and, in turn, the adapter assembly  100  is configured for selective connection with a tool assembly or end effector, e.g. tool assembly  30 , which may, in exemplary embodiments, include a loading unit  40  and an anvil assembly  50 , for applying a circular array of staples (not shown) to tissue (not shown). The handle assembly  20 , along with the adapter assembly  100  and the tool assembly  30  form a surgical stapling device  10 . Although shown and described for use with a circular stapling loading unit, it is envisioned that the aspects of the present disclosure may be modified for use with stapling assembly have alternative configurations. 
         [0039]    For a detailed description of the structure and function of an exemplary handle assembly, please refer to commonly owned U.S. Pat. Appl. Publ. Nos. 2012/0253329, 2015/0157320, and 2015/0157321 (“the &#39;329, &#39;320, and &#39;321 applications”), the content of each of which is incorporated by reference herein in its entirety. 
         [0040]    With continued reference to  FIGS. 2-4 , the adapter assembly  100  includes a proximal portion  102  ( FIG. 3 ) configured for operable connection to the handle assembly  20  ( FIG. 1 ), a distal portion  104  configured for operable connection to the tool assembly  30  ( FIG. 1 ), and an intermediate portion  106  operably connecting the proximal and distal portions  102 ,  104 . The proximal portion  102  of the adapter assembly  100  includes a coupling assembly  110  receivable within the handle assembly  20  ( FIG. 1 ) for operatively connecting first, second, and third drive shafts (not shown) of the handle assembly  20  with the adapter assembly  100 , and a drive assembly  115  ( FIG. 5 ) for transferring power from the handle assembly  20  to the tool assembly  30 . For a detailed description of an exemplary adapter assembly including an exemplary coupling assembly, please refer to commonly owned U.S. patent application Ser. No. 14/875,766 (“the &#39;766 application”), filed Oct. 21, 2014, the contents of which are incorporated herein by reference in their entirety, and the previously incorporated &#39;329, &#39;320, and &#39;321 applications. 
         [0041]    With reference to  FIGS. 5-9 , first, second, and third drive assemblies  120  ( FIGS. 7 and 8 ),  130 ,  140  of the adapter assembly  100  extend from the coupling assembly  110 , through an outer sleeve  108  ( FIG. 1 ) of the intermediate portion  106  ( FIG. 1 ), and to an actuation assembly  150  ( FIG. 10 ) disposed in the distal portion  104  ( FIG. 4 ) of the adapter assembly  100 . As will be described in further detail below, the first drive assembly  120  operates to effect a first function, e.g., clamping of tissue, of the tool assembly  30  ( FIG. 1 ). The second drive assembly  130  operates to effect a second function, e.g., stapling of tissue, of the tool assembly  30  ( FIG. 1 ). The third drive assembly  140  operates to effect a third function, e.g., cutting of tissue, of the tool assembly  30  ( FIG. 1 ). 
         [0042]    The first drive assembly  120  extends through the proximal and intermediate portions  102 ,  106  ( FIG. 2 ) of the adapter assembly  100  and includes a first elongate drive shaft  122  rotatably supported within the proximal portion  102  of the adapter assembly  100 , a first carriage assembly  124  movably supported by the first elongate drive shaft  122 , and a first push/pull cable  126  ( FIG. 8 ) secured to the first carriage assembly  124 . The first push/pull cable  126  extends from the first carriage assembly  124  through the intermediate portion  106  ( FIG. 2 ) to the actuation assembly  150  ( FIG. 10 ) in the distal portion  104  ( FIG. 4 ) of the adapter assembly  100 . 
         [0043]    With particular reference to  FIG. 9 , the first carriage assembly  124  of the first drive assembly  120  is in threaded engagement (not shown) with the first elongate drive shaft  122  of the first drive assembly  120 , such that rotation of the first elongate drive shaft  122  causes longitudinal movement, i.e., advancement and retraction, of the first carriage assembly  124 . Longitudinal movement of the first carriage assembly  124  of the first drive assembly  120  pushes and pulls the first push/pull cable  126  to effect longitudinal movement, i.e., advancement and retraction, of a trocar member  174  ( FIG. 18 ) of a trocar assembly  170  ( FIG. 18 ) disposed in the distal portion  104  ( FIG. 4 ) of the adapter assembly  100 . The first push/pull cable  126  is adjustably secured to the first carriage assembly  124  by a set screw  125  ( FIG. 9 ). The effective length of the first push/pull cable  126  may be adjusted using the set screw  125  to accommodate, for example, anvil assemblies of different sizes. 
         [0044]    The second drive assembly  130  extends through the proximal and intermediate portions  102 ,  106  ( FIG. 2 ) of the adapter assembly  100  and includes a second elongate drive shaft  132  rotatably supported within the proximal portion  102  of the adapter assembly  100 , a second carriage assembly  134  movably supported along the second elongate drive shaft  132 , and second and third push/pull cables  136 ,  138  secured to the second carriage assembly  134 . Although shown including two (2) push/pull cables, the second carriage assembly  134  is configured to accommodate up to six (6) push/pull cables. It is envisioned that the second carriage assembly  134  may be configured to accommodate any number of push/pull cables. In some embodiments, the second and third push/pull cables  136 ,  138  are small coiled throttle cables which are capable of handling large compressive loads without buckling while remaining flexible. The second and third push/pull cables  136 ,  138  are adjustably secured to the second carriage assembly  134  by set screws  135 . The effective length of the second and third push/pull cable  136 ,  138  may be adjusted using the set screws  135  to accommodate, for example, loading units having various sized pusher assemblies. 
         [0045]    With particular reference to  FIG. 9 , the second carriage assembly  134  of the second drive assembly  130  is in threaded engagement (not shown) with the second elongate drive shaft  132  of the second drive assembly  130 , such that rotation of the second elongate drive shaft  132  causes longitudinal movement, i.e., advancement and retraction, of the second carriage assembly  134 . Longitudinal movement of the second carriage assembly  134  pushes and pulls the second and third push/pull cables  136 ,  138  to effect longitudinal movement, i.e., advancement and retraction, of a first pusher member  154  ( FIG. 16 ) of the actuation assembly  150  ( FIG. 10 ) disposed in the distal portion  104  of the adapter assembly  100 . 
         [0046]    The third drive assembly  140  extends through the proximal and intermediate portions  102 ,  106  ( FIG. 2 ) of the adapter assembly  100  and includes a third elongate drive shaft  142  rotatably supported within the proximal portion  102  of the adapter assembly  100 , a third carriage assembly  144  movably supported along the third elongate drive shaft  142 , and fourth and fifth push/pull cables  146 ,  148  secured to the third carriage assembly  144 . Although shown including only two (2) push/pull cables  146 ,  148 , the third carriage assembly  144  is configured to accommodate up to four (4) push/pull cables. It is envisioned that the third carriage assembly  144  may be configured to accommodate any number of push/pull cables. In some embodiments, the fourth and fifth push/pull cables  146 ,  148  are small coiled throttle cables which are capable of handling large compressive loads without buckling while remaining flexible. The fourth and fifth push/pull cables  146 ,  148  are adjustably secured to the second carriage assembly  144  by set screws  145 . The effective length of the fourth and fifth push/pull cables  146 ,  148  may be adjusted using the set screws  145  to accommodate, for example, loading units having various sized pusher assemblies. 
         [0047]    With particular reference to  FIG. 9 , the third carriage assembly  144  of the third drive assembly  140  is in threaded engagement (not shown) with the third elongate drive shaft  142  of the third drive assembly  140 , such that rotation of the third elongate drive shaft  142  causes longitudinal movement, i.e., advancement and retraction, of the third carriage assembly  144 . Longitudinal movement of the third carriage assembly  144  pushes and pulls the fourth and fifth push/pull cables  146 ,  148  to effect longitudinal movement, i.e., advancement and retraction, of a second pusher member  156  ( FIG. 17 ) of the actuation assembly  150  ( FIG. 10 ) disposed in the distal portion  104  of the adapter assembly  100 . 
         [0048]    With particular reference to  FIGS. 7 and 8 , disposed between the coupling assembly  110  of the adapter assembly  100  and the first elongate drive shaft  122  of the first drive assembly  120  of the adapter assembly  100  is a first high ratio transmission assembly “T 1 ”. Disposed between the coupling assembly  110  of the adapter assembly  100  and the second elongate drive shaft  132  of the second drive assembly  130  of the adapter assembly  100  is a second high ratio transmission assembly “T 2 ”. A third high ratio transmission assembly “T 3 ” is disposed between the coupling assembly  110  of the adapter assembly  100  and the third elongate drive shaft  142  of the adapter assembly  100 . The first, second, and third high ratio transmission assemblies “T 1 ”, “T 2 ”, “T 3 ” convert the high speed, low torque rotary input from the handle assembly  20  ( FIG. 1 ) to lower speed, higher torque output for use in effecting actuation of the tool assembly  30  ( FIG. 1 ). Although shown as planetary gear systems, each of the first, second, and third high ratio transmission assemblies “T 1 ”, “T 2 ”, “T 3 ”, may be any type of suitable high ratio transmission assembly, e.g., orbital gear system, yoked sun orbital gear system, compound gear system. For a detailed description of an exemplary planetary gear system, please refer to the &#39;766 application, the content of which was previously incorporated by reference herein. 
         [0049]    With continued reference to  FIGS. 5-9 , the second and third push/pull cables  136 ,  138  of the second drive assembly  130  extend through a first opening  113   a  in a frame member  112  of the proximal portion  104  of the adapter assembly  100 , and the fourth and fifth push/pull cables  146 ,  148  extend through a second opening  113   b  in the frame member  112 . Each of the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  includes an outer sheath or service conduit  137 ,  139 ,  147 ,  149 , respectively. As noted above, proximal ends of the second and third cables  136 ,  138  are secured to the second carriage assembly  134  and proximal ends of the fourth and fifth cables  146 ,  148  are secured to the third carriage assembly  144 . Similarly, proximal ends of the respective second, third, fourth, and fifth outer sheaths  137 ,  139 ,  147 ,  149  of the respective second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  are secured to the frame member  112 . 
         [0050]    With additional reference to  FIG. 10 , the first push/pull cable  126  of the first drive assembly  120 , and each of the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  with respective outer sheaths  137 ,  139 ,  147 ,  149  of the second and third drive assemblies  130 ,  140 , respectively, extend through the intermediate portion  106  ( FIG. 1 ) of the adapter assembly  100  and operably engage the actuation assembly  150  disposed in the distal portion  104  of the adapter assembly  100 . 
         [0051]    As shown in  FIG. 10 , the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  are arranged in a helical pattern within the intermediate portion  106  of the adapter assembly  100 . It is envisioned that the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  may instead be arranged in a wave pattern ( FIG. 11 ), an offset wave pattern, or simple loop pattern ( FIG. 12 ). These arrangements provide service slack, i.e., extra length, in the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  of the respective second and third drive assemblies  130 ,  140  within the intermediate portion  106  of the adapter assembly  100 . In addition to accommodating the shortening and lengthening of the intermediate portion  106  of the adapter assembly during flexing of the adapter assembly  100 , the service slack allows for migration during cycling operation of the second and third drive assemblies  130 ,  140 . 
         [0052]    As will be described in further detail below, the inclusion of the service slack in each of the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  and the respective second, third, fourth, and fifth outer sheaths  137 ,  139 ,  147 ,  149  within the intermediate portion  106  of the adapter assembly  100  changes the relative frame of reference of the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  and the respective second, third, fourth, and fifth outer sheaths  137 ,  139 ,  147 ,  149 . The configuration of the adapter assembly  100  is such that when the second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  are pulled within the proximal portion  102  of the adapter assembly  100 , the second, third, fourth, and fifth outer sheaths  137 ,  139 ,  147 ,  149  of the respective second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  are pushed within the distal portion  104  of the adapter assembly  100 . 
         [0053]    With reference now to  FIGS. 13-17 , the actuation assembly  150  of the adapter assembly  100  includes a cylindrical housing  152  received within an inner sleeve  108   a  of the distal portion  104  of the adapter assembly  100 , the first and second pusher members  154 ,  156  slidably supported within the cylindrical housing  152 , first and second pairs of guide members  158   a,    158   b,    160   a,    160   b  secured relative to the cylindrical housing  152 , and first and second pairs of guide tubes  162   a,    162   b,    164   a,    164   b  ( FIG. 10 ) extending from respective first and second pusher members  154 ,  156  and about respective free ends of the first and second pairs of guide members  158   a,    158   b,    160   a,    160   b.    
         [0054]    With particular reference to  FIG. 13 , a proximal end of the cylindrical housing  152  of the actuation assembly  150  extends from a distal end of the inner sleeve  108   a  and both the cylindrical housing  152  and the inner sleeve  108   a  are received within a distal end of the outer sleeve  108  ( FIG. 1 ). A distal end of the cylindrical housing  152  releasably receives the loading unit  40  of the tool assembly  30  ( FIG. 2 ). 
         [0055]    With continued reference to  FIGS. 13-17 , the first pusher member  154  of the actuation assembly  150  is movably supported within the cylindrical housing  152  ( FIG. 13 ) of the actuation assembly  150  and the second pusher member  156  is moveably supported within the first pusher member  154 . The second and third outer sheaths  137 ,  139  ( FIG. 16 ) of the respective second and third push/pull cables  136 ,  138  ( FIG. 9 ) engage the first pusher member  154  ( FIG. 16 ) and the fourth and fifth outer sheaths  147 ,  149  ( FIG. 17 ) of the respective fourth and fifth push/pull cables  136 ,  148  ( FIG. 9 ) engage the second pusher member  156  ( FIG. 17 ). The first and second pusher members  154 ,  156  each define a plurality of slots  153  ( FIG. 16 ),  155  ( FIG. 17 ), respectively, for accommodating the first and second pairs of guide members  158   a,    158   b,    160   a,    160   b.    
         [0056]    As noted above, each of the first pair of guide members  158   a,    158   b  is integrally formed with, or securely connected to, the respective second and third push/pull cable  136 ,  138  ( FIG. 9 ), of the second drive assembly  130  of the adapter assembly  100 . Each guide member  158   a,    158   b  of the first pair of guide members engages the cylindrical housing  152  of the actuation assembly  150  (see, for example,  FIG. 14 ) to fix the second and third push/pull cables  136 ,  138  relative to the actuation assembly  150 . A free end of each of guide member  158   a,    158   b  of the first pair of guide members is received within the respective tubular guide  162   a,    162   b  extending from the first pusher member  154 . As noted above, the second drive assembly  130  includes two (2) push/pull cables  136 ,  138 , however, the second drive assembly  130  is capable of accommodating up to six (6) push/pull cables (not shown). In some embodiments, any or all of the tubular guides  162   a,    162   b  may be replaced with additional push/pull cables (not shown) and accompanying outer sheaths (not shown). 
         [0057]    During actuation of the second drive assembly  130 , each of the second and third push/pull cables  136 ,  138  are retracted distally through longitudinal movement of the second carriage assembly  134  of the second drive assembly  130 . As described in detail above, the configuration of the second and third push/pull cables  136 ,  138  of the second drive assembly  130 , and the accompanying second and third sheaths  137 ,  139 , respectively, facilitated by the service slack provided by, for example, the helical pattern of the second and third push/pull cables  136 ,  138  within the intermediate portion  106  of the adapter assembly  100 , is such that when the second and third push/pull cables  136 ,  138  are pulled, i.e., retracted, the second and third sheaths  137 ,  139  move distally, i.e., advance. Advancement of the second and third sheaths  137 ,  139  of the second drive assembly  130  causes distal movement of the first pusher member  154  of the actuation assembly  150 , as indicated by arrow “A” in  FIG. 16 . 
         [0058]    As noted above, each guide member  160   a,    160   b  of the second pair of guide members is integrally formed with, or securely connected to, the respective fourth and fifth push/pull cable  146 ,  148 , of the third drive assembly  140  of the adapter assembly  100 . Each guide member  160   a,    160   b  of the second pair of guide members engages the cylindrical housing  152  of the actuation assembly  150  to fix the fourth and fifth push/pull cables  146 ,  148  relative to the actuation assembly  150 . The free end of each guide member  160   a,    160   b  of the second pair of guide members is received within the respective tubular guide  164   a,    164   b  extending for the second pusher member  156 . As noted above, the third drive assembly  140  includes two (2) push/pull cables  146 ,  148 ; however, the third drive assembly  140  is capable of accommodating up to four (4) push/pull cables. In some embodiments, any or all of the tubular guides  164   a,    164   b  may be replaced with additional push/pull cables (not shown) and accompanying outer sheaths (not shown). 
         [0059]    During actuation of the third drive assembly  140 , each of the fourth and fifth push/pull cables  146 ,  148  are retracted distally through longitudinal movement of the third carriage assembly  144  of the third drive assembly  140 . As described in detail above, the configuration of the fourth and fifth push/pull cables  146 ,  148 , and the accompanying fourth and fifth sheaths  147 ,  149 , respectively, facilitated by the service slack provided by the, for example, helical pattern ( FIG. 2 ) of the fourth and fifth push/pull cables  146 ,  148  within the intermediate portion  106  of the adapter assembly  100 , is such that when the fourth and fifth push/pull cables  146 ,  148  are pulled, i.e., retracted, the fourth and fifth sheaths  147 ,  149  are moved distally, i.e., advanced. Advancement of the fourth and fifth sheaths  147 ,  149  of the third drive assembly  140  causes distal movement of the second pusher member  156  of the actuation assembly  150 , as indicated by arrow “B” in  FIG. 16 . 
         [0060]    Springs “S” received about the second, third, fourth, and fifth sheaths  137 ,  139 ,  147 ,  149  of the respective second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  facilitate the return of the second, third, fourth, and fifth sheaths  137 ,  139 ,  147 ,  149  to their initial positions when the respective second, third, fourth, and fifth push/pull cables  136 ,  138 ,  146 ,  148  are advanced, i.e., pushed distally. As the second, third, fourth, and fifth sheaths  137 ,  139 ,  147 ,  149  move proximally, the respective first and second pusher members  154 ,  156  are moved distally, i.e., retracted. 
         [0061]    When the loading unit  40  is secured to the cylindrical housing  152  of the actuation assembly  150 , the first pusher member  154  engages a staple pusher member  42  of the loading unit  40  and the second pusher member  156  engages a knife pusher member  44  of the loading unit  40 . The first and second pusher members  154 ,  156  are moveably supported within the cylindrical housing  152  to effect longitudinal movement of the respective stapler pusher member  42  and the knife pusher member  44 . 
         [0062]    With reference now to  FIGS. 18-23 , the trocar assembly  170  of the adapter assembly  100  is operably connected to the first drive assembly  120  and is operably received through the first and second pusher members  154 ,  156  of the actuation assembly  150 . More particularly, the trocar assembly  170  includes a locking member  172 , and a trocar member  174  releasably secured to the locking member  172 . The trocar member  174  may be formed of proximal and distal portions  174   a,    174   b,  as shown, or may be integrally formed, e.g., monolithic. 
         [0063]    A proximal end of the locking member  172  is securely connected to the first push/pull cable  126  of the first drive assembly  120  ( FIG. 8 ). A distal end of the locking member  172  includes a plurality of fingers  172   a  configured for releasably engaging the trocar member  174 . The plurality of fingers  172   a  are movable between a first position ( FIG. 18 ) in which the plurality of fingers  172   a  are splayed apart to facilitate the receipt of the trocar member  174  therein, and a second position ( FIG. 21 ) in which the plurality of fingers  172   a  are compressed about the trocar member  174  to secure the trocar member  174  therein. As will be described in further detail below, the plurality of fingers  172   a  are in the first position when the second pusher member  156  of the actuation assembly  150  is in a proximal-most position, thereby allowing the plurality of fingers  172   a  to splay outwardly. 
         [0064]    Each of the plurality of fingers  172   a  includes a locking feature, e.g., a pair of teeth  173 , and the proximal portion  174   a  of the trocar member  174  defines a corresponding locking feature, e.g., a pair of annular grooves  175 . The annular grooves  175  are positioned to receive the pairs of teeth  173  of the plurality of fingers  172   a  when the trocar member  174  is in engagement with the locking member  172  and the plurality of fingers  172   a  are in their second position. 
         [0065]    With particular reference to  FIG. 19 , the first drive assembly  120  is shown with the first push/pull cable  126  in a distal-most position. When in the distal-most position, a tissue piercing tip of the distal portion  174   b  of the trocar member  174  facilitates penetration of tissue (not shown) by the trocar member  174 . As shown, the second pusher assembly  156  of the actuation assembly  150  is in its proximal-most position. In this manner, the plurality of fingers  172   a  of the locking member  172  of the trocar assembly  170  is in its second position. 
         [0066]    Turning to  FIG. 20 , actuation of the first drive assembly  120  causes pulling, i.e., retraction, of the first push/pull cable  126 , as indicated by arrow “C” in  FIG. 19 , to retract the trocar member  174  within the plurality of fingers  172   a  of the locking member  172  of the trocar assembly  170 . Prior to, or simultaneously with the retraction of the first push/pull cable  126 , the third drive assembly  140  ( FIG. 7 ) is actuated to cause the retraction of the second pusher member  156 , as indicated by arrow “D” in  FIG. 19 , to its proximal-most position, in the manner described above. Alternatively, the adapter assembly  100  is provided to a clinician with the second pusher member  156  of the actuation assembly  150  in its proximal-most position, thereby eliminating the need to retract the second pusher member  156  prior to securing the trocar member  174  to the locking member  172 . 
         [0067]    Turning to  FIG. 21 , upon receipt of the trocar member  174  of the trocar assembly  170  within the locking member  172  of the trocar assembly  170 , the second pusher member  156  of the actuation assembly  150  is returned to its initial position, i.e., advanced, through operation of the third drive assembly  140 . As the second pusher member  156  advances relative to the locking member  172 , engagement between the second pusher member  156  and the plurality of fingers  172   a  of the locking member  172  causes the plurality of fingers  172   a  to flex radially inwardly about the proximal portion  174   a  of the trocar member  174  such that the pairs of teeth  173  of the plurality of fingers  172   a  of the locking member  172  are received within the annular grooves  175  of the trocar member  174 . In this manner, the trocar member  174  is secured to the locking member  172 . 
         [0068]    With reference to  FIG. 22 , during operation of the surgical stapling device  10 , actuation of the first drive assembly  120  ( FIG. 8 ), in the manner described above, effects movement of the trocar assembly  170 , as indicated by arrow “D”. When the anvil assembly  50  is secured to the distal portion  174   b  of the trocar member  174  of the trocar assembly  170 , movement of the trocar assembly  170  causes a clamping of tissue between, for example, the anvil assembly  50  ( FIG. 1 ) and the loading unit  40  of the tool assembly  30  ( FIG. 1 ). 
         [0069]    Subsequent to the clamping of tissue (not shown), actuation of the second drive assembly  130  ( FIG. 8 ), in the manner described above, effects movement of the first pusher member  154  of the actuation assembly  150 , as indicated by arrow “E” in  FIG. 21 . As noted above, the first pusher member  154  is connected to the staple pusher member  42  ( FIG. 13 ) of the loading unit  40  ( FIG. 13 ). Accordingly, advancement of first pusher member  154  of the actuation assembly  150  causes advancement of the stapler pusher member  42  of the loading unit  40  to effect the stapling of tissue (not shown) that is clamped between the anvil assembly  50  ( FIG. 1 ) and the loading unit  40  of the tool assembly  30  ( FIG. 1 ). 
         [0070]    Turning to  FIG. 23 , subsequent to the stapling of tissue (not shown), actuation of the third drive assembly  140 , in the manner described above, effects movement of the second pusher member  156  of the actuation assembly  150 , as indicated by arrow “F” in  FIG. 22 . As noted above, the second pusher member  156  is connected to the knife pusher member  44  ( FIG. 13 ) of the loading unit  40  ( FIG. 13 ). Accordingly, advancement of second pusher member  156  of the actuation assembly  150  causes advancement of the knife pusher member  44  of the loading unit  40  to effect the cutting of tissue (not shown) that is clamped between anvil assembly  50  ( FIG. 1 ) and the loading unit  40  of the tool assembly  30  ( FIG. 1 ). 
         [0071]    Although the adapter assembly  100  has been shown and described in relation to operation of the tool assembly  30  ( FIG. 1 ) including the loading unit  40  ( FIG. 1 ) and the anvil assembly  50  ( FIG. 1 ), the adapter assembly  100  may be modified for operation with end effectors having different configurations. For example, the adapter assembly  100  may be modified for use with an end effector having only a single actuation, e.g., linear stapling. 
         [0072]    Any of the components described herein may be fabricated from either metals, plastics, resins, composites or the like taking into consideration strength, durability, wearability, weight, resistance to corrosion, ease of manufacturing, cost of manufacturing, and the like. 
         [0073]    Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.