WO2015065484A1 - Surgical fastener applying apparatus - Google Patents

Abstract

The surgical stapling device (10) includes a housing (20), an outer tube (60) extending distally from the housing, a disposable staple assembly (300) releasably supported on a distal end of the outer tube, an approximation assembly (100) operably received within the housing, and a staple pusher assembly (200) extending from within the housing to the distal end of the outer tube. The outer tube includes a proximal end configured for operable connection with the housing and a distal end. The staple assembly includes a shell (302) supporting a pusher back (310), and a plurality of fasteners S. The pusher back being axially movable within the shell to eject the plurality of fasteners from the disposable staple assembly, the shell being adapted to be rotabably connected to the outer tube. The approximation assembly includes an anvil retainer (140) releasably engageable with an anvil assembly (80). The approximation assembly being operable to approximate the anvil assembly and the staple assembly. The staple pusher assembly adapted to be rotatably connected to the pusher back of the disposable staple assembly and operable to effect axial movement of the pusher back within the shell. The approximation assembly and the staple pusher assembly are releasably secured within the housing.

Description

SURGICAL FASTENER APPLYING APPARATUS

Background

1. Technical Field

[0001] The present disclosure relates to a surgical fastener applying apparatus and, more particularly, to surgical fastener applying apparatus having reusable and disposable components.

2. Discussion of Related Art

[0002] Anastomosis refers to the surgical joining of separate hollow tissue sections.

Typically, an anastomosis procedure follows surgery in which a diseased or defective section of a hollow tissue structure is removed, thus requiring the joining of the remaining end sections of the tissue structure. Depending on the particular procedure being performed and/or other factors, the end sections of the tissue may be joined by circular anastomosis, e.g., end-to-end anastomosis, end-to-side anastomosis, or side-to-side anastomosis.

[0003] In a circular anastomosis procedure, the two end sections of a tubular organ are joined using a stapling apparatus that drives a circular array of staples through each of the end sections to join the end sections to one another in end-to-end relation and simultaneously cores any tissue within the newly joined hollow tissue structure to clear the passage defined by the hollow tissue structure. The apparatus can also apply other surgical fasteners such as, for example, clips or two part polymeric surgical fasteners.

[0004] A typical circular anastomosis apparatus includes an elongated shaft having a handle portion at a proximal end and a staple holding component at a distal end. An anvil assembly including an anvil rod and an attached anvil head is mounted to the distal end of the elongated shaft adjacent the staple holding component. In use, the end portions to be joined are clamped between the anvil head and the staple holding component. The clamped end portions are then joined to one another by driving one or more staples from the staple holding component, through the tissue, and into the anvil head to form the staples about the tissue. In some such apparatus, a knife is provided to cut the tissue which has been joined by the staples. Examples of such circular anastomosis apparatus are described in U.S. Patent Nos. 7,857,187 to Milliman ("the Milliman Ί87 patent" and 6,945,444 to Gresham et al. ("the Gresham '444 patent"), the entire contents of which are hereby incorporated by reference herein in their entireties.

[0005] Typically, surgical stapling apparatus for performing circular anastomosis procedures are disposable after a single use. Because of the high costs associated with the use of disposable surgical stapling apparatus, a need exists for a surgical stapling apparatus that includes reusable components and is not overly complex and is configured to facilitate effective sterilization after use in a surgical procedure.

SUMMARY

[0006] Accordingly, a surgical stapling device is provided. The surgical stapling device includes a housing, an outer tube extending distally from the housing, a disposable staple assembly releasably supported on a distal end of the outer tube, an approximation assembly operably received within the housing, and a staple pusher assembly extending from within the housing to the distal end of the outer tube. The outer tube includes a proximal end configured for operable connection with the housing and a distal end. The staple assembly includes a shell supporting a pusher back, and a plurality of fasteners. The pusher back being axially movable within the shell to eject the plurality of fasteners from the disposable staple assembly, the shell being adapted to be rotabably connected to the outer tube. The approximation assembly includes an anvil retainer releasably engageable with an anvil assembly. The approximation assembly being operable to approximate the anvil assembly and the staple assembly. The staple pusher assembly adapted to be rotatably connected to the pusher back of the disposable staple assembly and operable to effect axial movement of the pusher back within the shell. The approximation assembly and the staple pusher assembly are releasably secured within the housing.

[0007] In some embodiments, the housing includes a first housing section, a second housing section and a chassis pivotally connect to each of the first and second housing sections. The first and second housing sections may be configured to be separated to provide access to an interior of the housing. The staple pusher assembly may be configured to be sterilized. The staple pusher assembly may include a pusher linkage for effecting ejection of the staples from the staple assembly. The outer tube may include at least one tab and the shell includes thread positioned to engage the at least one tab to releasably secure the shell to the outer sleeve. The at least one tab may include two tabs configured to engaged the thread formed on the shell. The pusher back may include thread and the staple pusher assembly includes a pusher defining at least one tab position to engage the at least one tab to releasably secure the pusher back to the pusher. The at least one tab may include two tabs configured to engaged the thread formed on the pusher. Also provided is a method of performing a circular stapling procedure. The method includes the steps of, positioning a surgical stapler within a patient such that tissue to stapled is disposed between an anvil assembly and a first staple assembly, the first staple assembly including a first circular array of staples, performing a first stapling procedure by ejecting the first circular array of staples from the first staple assembly, removing the surgical stapler from within the patient, replacing the first staple assembly of the surgical stapler with a second staple assembly, the second staple assembly including a second circular array of staples, repositioning the surgical stapler within the patient, and performing a second stapling procedure by ejecting the second circular array of staples from the second staple assembly. The method may also include the steps of, replacing the first staple assembly includes rotating the first staple assembly in a first direction relative to an elongated body portion of the surgical stapler to disconnect the first staple assembly from the elongated body portion and rotating the second staple assembly in a second direction relative to the elongated body portion to connect the second staple assembly with the elongated body portion.

Brief Description Of The Drawings

[0008] Various embodiments of the presently disclosed surgical fastener applying apparatus will now be described herein with reference to the accompanying figures wherein:

[0009] FIG. 1 is a perspective view of an embodiment of the presently disclosed surgical stapling device including an anvil assembly in the unapproximated position;

[0010] FIG. 2 is an enlarged view of the indicated area of detail shown in FIG. 1 ;

[0011] FIG. 3 is a side view of the surgical stapling device shown in FIG. 1 without an anvil assembly;

[0012] FIG. 4 is a side perspective view from the proximal end of the surgical stapling device shown in FIG. 1 without an anvil assembly;

[0013] FIG. 5 is an exploded perspective view of the surgical stapling device shown in

FIG. 1;

[0014] FIG. 6 is a side, perspective view of the housing of the surgical stapling device shown in FIG. 1;

[0015] FIG. 7 is a side, perspective exploded view of the housing shown in FIG. 6;

[0016] FIG. 8 is a side, perspective view of the handle assembly of the surgical stapling device of FIG. 1; [0017] FIG. 9 is a side, perspective view of the handle assembly shown in FIG. 8 with a housing section removed showing the internal components of the handle assembly;

[0018] FIG. 10 is a side, perspective view of the approximation assembly of the surgical stapling device of FIG. 1;

[0019] FIG. 11 is an enlarged view of the indicated area of detail shown in FIG. 10;

[0020] FIG. 12 is a perspective view of the approximation assembly shown in FIG. 10 with parts separated;

[0021] FIG. 13 is a perspective view of a rotatable sleeve of the approximation assembly shown in FIG. 10;

[0022] FIG. 14 is a cross-sectional side view of the rotatable sleeve shown in FIG. 13 connected to the proximal end of a screw of the approximation assembly shown in FIG. 10;

[0023] FIG. 15 is a perspective view of a staple pusher assembly of the surgical stapling device shown in FIG. 1;

[0024] FIG. 16 is an enlarged view of the indicated area of detail shown in FIG. 15;

[0025] FIG. 17 is a perspective view of the staple pusher assembly shown in FIG. 15 with parts separated;

[0026] FIG. 18 is an enlarged cross-sectional side view of a distal end of the staple pusher assembly shown in FIG. 15;

[0027] FIG. 19 is a side, cross-sectional view of the distal end of the staple pusher assembly taken along section line 19-19 of FIG. 18;

[0028] FIG. 20 is a side, cross-sectional side view of the distal end of the staple pusher assembly shown in FIG. 19 with parts further pivoted relative to each other; [0029] FIG. 21 is a side, perspective view from the distal end of a staple assembly of the surgical stapling device of FIG. 1 with parts separated;

[0030] FIG. 22 is a perspective view from the proximal end of the staple assembly shown in FIG. 21;

[0031] FIG. 23 is an perspective view from the proximal end of a pusher back of the staple assembly shown in FIG. 21;

[0032] FIG. 24 is a perspective view of the staple assembly shown in FIG. 21 positioned adjacent a distal end of an outer tube of the surgical stapling device shown in FIG. 1;

[0033] FIG. 25 is a side, perspective view of the distal end of the outer tube shown in

FIG. 24;

[0034] FIG. 26 is a side, perspective view of the distal end of the staple pusher assembly shown in FIG. 18;

[0035] FIG. 27 is a side, perspective side view from the proximal end of the anvil assembly of the surgical stapling device shown in FIG. 1;

[0036] FIG. 28 is a side, perspective view of the anvil assembly of the surgical stapling device shown in FIG. 1;

[0037] FIG. 29 is a side, cross-sectional view of the surgical stapling device shown in

FIG. 1, in an initial or unapproximated position prior to attachment of the anvil assembly;

[0038] FIG. 30 is an enlarged view of the indicated area of detail shown in FIG. 29;

[0039] FIG. 31 is an enlarged view of the indicated area of detail shown in FIG. 29;

[0040] FIG. 32 is an enlarged view of the indicated area of detail shown in FIG. 31 ;

[0041] FIG. 33 is a cross-sectional top view taken along lines 33-33 of FIG. 31; [0042] FIG. 34 is a side cross-sectional view of the handle assembly of the surgical stapling device shown in FIG. 1 with the anvil assembly in an approximated position;

[0043] FIG. 35 is an enlarged view of the indicated area of detail shown in FIG. 34;

[0044] FIG. 36 is a top view of the surgical stapling device shown in FIG. 1, in an approximated position.;

[0045] FIG. 37 is an enlarged view of the indicated area of detail shown in FIG. 37;

[0046] FIG. 38 is a side, cross-sectional view of the distal portion of the surgical stapling device shown in FIG. 1, in an approximated position;

[0047] FIG. 39 is a side, cross-sectional view of the handle portion of the surgical stapling device shown in FIG. 1, in a fired position;

[0048] FIG. 40 is an enlarged view of the indicated area of detail shown in FIG. 39;

[0049] FIG. 41 is a cross-sectional side view of the distal portion of the surgical stapling device shown in FIG. 1, in a fired position;

[0050] FIG. 42 is a perspective view with parts separated of a staple pusher assembly according to an alternative embodiment of the present disclosure;

[0051] FIG. 43 is a side, cross-sectional view of the handle assembly of a surgical stapling device including a staple pusher assembly show in FIG. 42 with the trigger lock in a locked position;

[0052] FIG. 44 is a side, cross-sectional view of a handle assembly including the staple pusher assembly shown in FIG. 42 with the trigger lock in an unlocked position;

[0053] FIG. 45 is a perspective view with parts separated from the distal end of a staple assembly according to an alternative embodiment of the present disclosure; [0054] FIG. 46 is a side, perspective view of a shell of the staple assembly shown in FIG.

45; and,

[0055] FIG. 47 is a side, perspective end view of a pusher back of the staple assembly shown in FIG. 45.

Detailed Description of Embodiments

[0056] Embodiments of the presently disclosed surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. Throughout this description, the term "proximal" will refer to the portion of the instrument closer to the operator and the term "distal" will refer to the portion of the instrument further from the operator.

[0057] FIGS. 1-41 illustrate one embodiment of the presently disclosed surgical fastener applying apparatus designated generally as surgical stapling device 10. The stapling device 10 is intended to be resterilized and reused. As will become apparent from the following disclosure, stapling device 10 is constructed as a plurality of assemblies that are selectively retained within a housing. The construction of stapling device 10 facilitates the sterilization of surgical device 10 between uses.

[0058] With reference initially to FIGS. 1-4, stapling device 10 includes a proximal handle portion 12, an elongated curved central body portion 14 and a distal head portion 16. Alternately, in some surgical procedures, e.g., the treatment of hemorrhoids, it may be desirable to have a substantially straight, shortened, central body portion. The length, shape and/or the diameter of any of handle portion 12, body portion 14 and head portion 16 may also be selected to suit a particular surgical procedure. [0059] With reference now to FIGS. 3-5, handle portion 12 of stapling device 10 includes a housing 20 which supports proximal portions of an approximation assembly 100 and a staple pusher assembly 200, as will be discussed in further detail below. Body portion 14 of stapling device 10 includes an outer tube 60 which supports elongated portions of approximation assembly 100 and elongated portions of staple pusher assembly 200. Head portion 16 of stapling device 10 includes a staple assembly 300 which is supported on a distal end 64 of outer tube 60 and is operably connected with a distal end of staple pusher assembly 200.

[0060] To allow for repeated use of surgical stapling device 10, each component of surgical stapling device 10 must either be capable of sterilization or replacement. In an embodiment, each of housing 20, outer tube 60, approximation assembly 100 and staple pusher assembly 200 are configured to be reused while staple assembly 300 is configured to be replaced. As such, except where otherwise noted, the components of surgical stapling device 10 are generally formed from thermoplastics including polycarbonates, and metals including stainless steel and aluminum, that are suited to withstand repeated sterilization procedures, e.g., autoclaving.

[0061] With particular reference now to FIGS. 6-9, housing 20 of surgical stapling device

10 (FIG. 1) includes housing sections 20a, 20b which are operably connected to a frame or chassis 40 (FIG. 6). Housing sections 20a, 20b are configured to permit access to approximation assembly 100 and staple pusher assembly 200 and to facilitate sterilization of housing 20 and chassis 40. Housing sections 20a, 20b are each configured to be pivotally secured to chassis 40 along a first longitudinal edge 22a, 22b, respectively. Each of first longitudinal edges 22a, 22b defines a step or cutout 23 a, 23b configured to receive an attachment portion 42 of chassis 40. Slots 25a, 25b are formed in respective housing sections 20a, 20b on either end of cutout 23a, 23b, respectively, and are each configured to receive a pivot pin 30. As will be discussed in further detail below, pivot pins 30 pivotally connect housing sections 20a, 20b to chassis 40. Slots 25a, 25b may be configured, as shown, to receive pivot pins 30 in a snap-fit manner to facilitate separation of housing sections 20a, 20b from chassis 30. A second longitudinal edge 24a, 24b (FIG. 8) of each of housing section 20a, 20b, respectively, each define a recess 27a, 27b, which when housing 20 is in a closed configuration (FIG. 6), form an opening 27 configured to accommodate a firing trigger 202 of staple pusher assembly 200 (FIG. 8). A latch 32 is formed adjacent a proximal end of recesses 27a, 27b. As will be discussed in further detail below, latch 32 is configured to engage and secure an end of a trigger lock 260 of staple pusher assembly 200 to retain trigger lock 260 in a locked position. Second longitudinal edges 24a, 24b of housing sections 20a, 20b may each include a clasp (not shown) or other mechanism for securing housing 20 in the closed configuration.

[0062] Each housing section 20a, 20b includes a threaded proximal portion 26a, 26b, respectively, and a threaded distal portion 28a, 28b, respectively. As will be discussed in further detail below, when first and second housing sections 20a, 20b are in a closed configuration (FIG. 6), proximal threaded portions 26a, 26b (collectively, threaded proximal portion 26) are configured to selectively receive a proximal ferrule 70 (FIG. 8) thereabout and distal threaded portions 28a, 28b (collectively, threaded distal portion 28) are configured to selectively receive a distal ferrule 72 (FIG. 8) thereabout. Proximal and distal ferrules 70, 72 are configured to maintain housing sections 20a, 20b in the closed position. Cushioned and/or resilient slip resistant grip portions may be fastened to or included as part of housing sections 20a, 20b. The slip resistant grip portions may be formed over housing sections 20a, 20b using an overmolding procedure and may be formed from neoprene or rubber. Alternately, other suitable materials, e.g., elastomeric materials, and joining techniques may be employed to secure a slip resistant portion to housing sections 20a, 20b.

[0063] With continued reference to FIGS. 6-9, chassis 40 includes a base 41 having an attachment portion 42, a proximal extension 44 and a distal extension 46. Base 41 is sized to extend substantially the length of housing 20. Base 41 includes a position indicator 50 in the form of a window 50a. As will be discussed in further detail below, position indicator 50 is configured to provide indication of the position of approximation assembly 100, i.e., unapproximated and approximated, and staple pusher assembly 200, i.e., unfired and fired. As shown, attachment portion 42 of base 41 is configured to pivotally and releasably engage housing sections 20a, 20b of housing 20 in a fashion that permits ready separation of housing sections 20a, 20b from chassis 40 to facilitate sterilization of stapling device 10. In particular, each of a proximal facing surface 42a and a distal facing surface 42b of attachment portion 42 define a pair of openings 43, 45, respectively, (FIGS. 6 and 9) one on each side of proximal and distal extensions 44, 46, respectively, each configured to receive a first end of pin 30. As noted above, slots 25a, 25b, formed in respective housing sections 20a, 20b along first longitudinal edge 22a, 22b, respectively, are each configured to receive a second end of pin 30. Alternatively, housing sections 20a, 20b may be connected to attachment portion 42 of base 41 with a living hinge that may or may not be releasable.

[0064] With reference still to FIGS. 6-9, proximal extension 44 of base 41 includes a proximal annular flange 52 defining an opening 53. Proximal annular flange 52 is configured to support a rotatable sleeve 110 of approximation assembly 100, as will be discussed in further detail below. In particular, first opening 53 is sized such that rotatable sleeve 110 is received and rotatably supported within flange 52 about the longitudinal axis of rotatable sleeve 52 during approximation and unapproximation of an anvil assembly 80 (FIG. 1) during use of surgical stapling device 10. Distal extension 46 of base 41 includes a distal annular flange 54 defining an opening 55. Distal annular flange 54 is configured to support an elongated pusher tube 230 of staple pusher assembly 200. In particular, second opening 55 is sized such that elongated pusher tube 230 is longitudinally advanced and retracted within annular flange 54 as firing trigger 202 of staple pushing assembly 200 is actuated, i.e., compressed toward housing 20 and released during use of surgical stapling device 10.

[0065] Turning briefly to FIGS. 5 and 25, as noted above, outer tube 60 extends distally from housing 20. Openings 61 (FIG. 5) formed in a proximal end 62 of outer tube 60 are dimensioned to receive protrusions 21 (FIG. 7) formed on the internal wall of housing sections 20a, 20b to facilitate attachment of outer tube 60 to housing 20 when housing 20 is in a closed position (FIG. 6). Proximal end 62 of outer tube 60 further includes a flange member 63. As will be discussed in further detail below, flange member 63 is configured to provide a stop surface for a spring 235 of staple pusher assembly 200. A distal end 64 of outer tube 60 is configured for operable connection with a proximal end of staple assembly 300. In particular, distal end 64 of outer tube 60 includes an area of reduced diameter 66 having a pair of radially outward extending tabs 68 configured for selective connection with a shell 302 of stapling assembly 300 (FIG. 21).

[0066] Approximation assembly 100 will now be described in detail with reference to

FIGS. 5 and 9-14. Approximation assembly 100 includes an approximation knob 102, a rotatable sleeve 110, a drive screw 120, a screw extension 130, an anvil retainer 140, a screw stop 150 and a cam mechanism 160. Rotatable sleeve 110 includes a substantially cylindrical hollow body portion 112 and a substantially cylindrical collar 114 which together define a central bore 113 (FIG. 14). Collar 114 has an annular groove 114a formed thereabout which is dimensioned to receive an inwardly extending flange 27 (FIG. 7) formed on an inner wall of housing sections 20a, 20b. Engagement between groove 114a and flange 27 axially fixes sleeve 110 within housing 20 while permitting rotation of sleeve 110 in relation to housing 20. With particular reference to FIGS. 13 and 14, cylindrical collar 114 of rotatable sleeve 110 includes a ball detent assembly 115 having a plug 116 and a detent member. In an embodiment, the detent member includes a ball 118a. As will be discussed in further detail below, ball 118a extends into central bore 113 of rotatable sleeve 110 from a recess 117 of cylindrical collar 114 and is received in a helical channel 121 of drive screw 120. Plug 116 defines a semi-spherical concavity 116a for receiving a side of ball 118a opposite screw 120 to retain ball 118a within recess 117 of cylindrical collar 114. Plug 118a defines a bore 116b for receiving pin 118b. Pin 118b extends through openings 119 in cylindrical collar 114 and bore 116b of plug 1 16 to secure plug 116 and ball 1 18a within recess 117 of cylindrical collar 114. Recess 117 includes a cutout 117a for receiving a rib 116c of plug 116 to properly align bore 116b of plug 116 with openings 117 in cylindrical collar 114.

[0067] A proximal end of body portion 112 of rotatable sleeve 110 extends through an opening 21 in a proximal end of housing 20. Approximation knob 102 is rotatably affixed to rotatable sleeve 112 such that rotation of knob 102 causes concurrent rotation of rotatable sleeve 110. Approximation knob 102 may be selectively or permanently affixed to rotatable sleeve 110, i.e., snap-fit connection, interference fit connection, adhesive, welding, and/or mechanical fasteners. Approximation knob 102 may include one or more protrusions and/or slots for engagement with one or more slots and/or protrusions formed on rotatable sleeve 110 to rotatably fix approximation knob 102 relative to sleeve 110. [0068] With reference still to FIGS. 5 and 9-14, a proximal half 120a of screw 120 includes helical channel 121 and is dimensioned to be slidably positioned within central bore 113 of rotatable sleeve 110. A distal end 120b of screw 120 may include an annular recess (not shown) dimensioned to receive a seal member (not shown) for providing a fluid tight seal between the outer surface of screw 120 and the inner surface of pusher linkage 220 of staple pusher assembly 200. As described above, ball 118a of ball detent mechanism 115 extends into helical channel 121 of screw 120. Since sleeve 110 is axially fixed with respect to housing 20, rotation of sleeve 110 about screw 120 causes ball 118a to move along channel 121 of screw 120 to effect axial movement of screw 120 within housing 20. Although shown having helical channel 121 configured to receive ball 118a, it is envisioned that screw 120 may alternatively include a helical thread (not shown) on an outer surface thereof configured to be received within a channel or groove (not shown) formed on an inner surface of sleeve 110.

[0069] Located between proximal end 120a and distal end 120b of screw 120 is an indicator member 122 (FIG. 12). Indicator member 122 includes a first indicator 122a and a second indicator 122b. As will be discussed in further detail below, first indicator 122a is configured to be viewed through window 50a of position indicator 50 in base 41 of chassis 40 when approximation assembly 100 is in a first or unapproximated position. Second indicator 122b is configured to be viewed through window 50a of position indicator 50 when approximation mechanism 100 is a second or approximated position (FIG. 33).

[0070] With particular reference to FIG. 12, threaded bore 123 and a cut-out or recess

125 are defined between proximal end 120a and distal end 120b of screw 120. As will be described in further detail below, threaded bore 123 is configured to receive a set screw 164 of a cam adjustment member 160 and cut-out 125 is configured to receive a protrusion 206 of a lockout feature of a trigger handle 202 of staple pusher assembly 200.

[0071] With reference to FIGS. 5 and 12, distal end 120b of screw 120 defines a transverse slot 127a and a throughbore 127b formed perpendicular to transverse slot 127a. Transverse slot 127a is configured to receive a proximal end of screw extension 130 and throughbore 127b is configured to receive a pin 126 for securing screw extension 130 to screw 120.

[0072] With reference now to FIGS. 10-12, screw extension 130 includes a flexible flat band having proximal and distal portions 132, 134. Although shown including only a single flexible flat band, it is envisioned that screw extension 130 may include more than one flexible flat band. Alternately, it is envisioned that screw extension 130 may have other than a flexible flat band configuration. For example, screw extension 130 may be semi-circular or circular in cross-section. The flexibility of screw extension 130 permits movement of screw extension 130 through curved elongated body portion 14. Proximal portion 132 of screw extension 130 includes a hole 133 dimensioned to receive a pin 126 for securing proximal portion 132 of screw extension 130 within transverse slot 127a of screw 120. Alternately, other fastening techniques may be used to secure flat band portion 132 to screw 120, e.g., welding, crimping, etc. Distal portion 134 of screw extension 130 is configured to be received within a transverse slot 141a (FIG. 12) formed in a proximal end 142 of anvil retainer 140 to fasten anvil retainer 140 to distal end 134 of screw extension 130. In one embodiment, and as shown, a pin 144 extends through an opening 141b defined in proximal end 142 of anvil retainer 140 and hole 135 in distal portion 134 of screw extension 130 to secure screw extension 130 to anvil retainer 140. Alternately, distal portion 134 of screw extension 130 may be secured within slot 141a using any other fastening technique, e.g., screws, crimping, brazing, welding or the like to secure distal portion 134 of screw extension 130 to anvil retainer 140.

[0073] Anvil retainer 140 includes an annular protrusion 146 which is configured to releasably engage anvil assembly 80 in a manner to be discussed in detail below. Alternately, protrusion 146 need not be annular or may include different attachment structure, e.g., recesses, grooves, etc.

[0074] Referring again to FIGS. 5 and 9-14, when approximation knob 102 is manually rotated, rotatable sleeve 110 is rotated about proximal end 120a of screw 120 to move ball 118a (FIG. 13) along helical channel 121 of screw 120. Since sleeve 110 is axially fixed to housing 20, as ball 118a is moved relative to channel 121, screw 120 is advanced or retracted within housing 20. As a result, screw extension 130, which is fastened at its proximal end to distal end 124 of screw 120, and at its distal end to anvil retainer 140, is moved axially within elongated body portion 14. Since anvil assembly 80 (FIG. 1) is secured to the distal end of anvil retainer 140, rotation of approximation knob 102 will effect movement of anvil assembly 80 in relation to staple assembly 300 (FIG. 1) between a spaced or unapproximated position and an approximated position.

[0075] With particular reference now to FIGS. 10-12, cam adjustment member 160 is secured by set screw 164 onto a sidewall 150a of screw stop 150 within a recess 150b formed in sidewall 150a. Cam adjustment member 160 includes a circular disc 162 having a throughbore 163. Throughbore 163 is eccentrically formed through disc 162 and is dimensioned to receive set screw 164. A smaller notch or hole 165 is also formed in disc 162 and is dimensioned to receive a tip of an adjustment tool (not shown). Set screw 164 extends through disc 162 and screw stop 150 and is received in a threaded bore 121a in proximal end 120a of screw 120 to secure screw stop 150 in an axially fixed position on screw 120. Cam adjustment member 160 functions to adjust the axial position of screw stop 150 on screw 120. More specifically, set screw 164 may be loosened to allow disc 162 to rotate within recess 150b of screw stop 150. For a more detailed description of the structure and function of stop member 150 and cam adjustment member 160, please refer to commonly owned U.S. Patent No. 7,303,106, the disclosure of which is incorporated by reference herein in its entirety.

[0076] When stapling device 10 is in a fully approximated position, i.e., anvil assembly

80 and staple assembly 300 are brought into juxtaposed alignment to define a tissue receiving clearance (FIG. 38), screw stop 150 abuts against a distal end of body portion 112 of the rotatable sleeve 110, i.e., cylindrical collar 114 of sleeve 110 functions as a stop for approximation assembly 100 (FIG. 35). In this position, anvil assembly 80 and staple assembly 300 are spaced slightly to define a tissue receiving clearance or minimum tissue gap. By providing cam adjustment member 160, the tissue receiving clearance or minimum tissue gap may be selectively adjusted to be within a desired range by adjusting the position of screw stop 150 on screw 120. In one embodiment, cam adjustment member 160 permits adjustment of the tissue receiving clearance of ±0.045 inches, although greater or lesser adjustment capabilities are also envisioned. Typically, adjustments to the tissue receiving clearance will be made by the device manufacturer. Alternately, a hole or opening may be provided in handle portion 12 (FIG. 1) to provide direct access to adjustment member 160 to allow for on-site adjustment of the tissue receiving clearance by a surgeon or other medical professional. Adjustment member 160 may also be adjusted between uses when housing 20 is opened and approximation assembly 100 is removed from housing 20 for sterilization purposes. [0077] Staple pushing assembly 200 will now be described with reference to FIGS. 15-

20. Staple pusher assembly 200 includes firing trigger 202, a firing link 210, and a pusher linkage 220. Pusher linkage 220 includes an elongated pusher tube 230, a pusher link 240 and a pusher end tube 250. Pusher linkage 220 is configured for transferring force from proximal handle portion 12 (FIG. 1) to distal head portion 16 (FIG. 1). Although shown to include a three- part assembly, it is envisioned that pusher linkage 220 may include one or more additional sections. Optionally, staple pushing assembly 200 includes a trigger lock 260.

[0078] With particular reference now to FIG. 17, firing trigger 202 is configured for operable engagement by a user. Firing trigger 202 may support cushioned gripping surface (not shown) formed of neoprene, rubber or the like. The cushioned gripping surface provides a non- slip cushioned surface to make actuation of stapling device 10 more comfortable to a surgeon. Alternatively, firing trigger 202 may be formed of perforated stainless-steel or other metal to facilitate sterilization. The distal end of trigger 202 includes a pair of flanges 204a, 204b each defining an opening 205a, 205b, respectively. As will be discussed in further detail below, flanges 204a, 204b are configured for pivotal connection with a pair of flanges 224 formed on proximal end 230a of elongated pusher tube 230 of pusher linkage 220 by a pivot member 208a. Alternatively, pusher linkage 220 may include a coupling member (not shown), integrally formed with or fixedly secured to, end 230a of pusher tube 230 for pivotally connecting firing trigger 202 with pusher linkage 220.

[0079] With reference still to FIG. 17, firing trigger 202 further includes a lockout feature, e.g., protrusion 206, extending from a distal end of firing trigger 202 adjacent flanges 204a, 204b. Protrusion 206 is configured to engage distal end 120b of screw 120 of approximation assembly 100 when approximation assembly 100 is in an unapproximated position to prevent accidental actuation of firing lever 202, i.e., firing of stapling device 10. As will be discussed in further detail below, when approximation assembly 100 is in the approximated position, recess 125 (FIG. 12) formed in distal end 120b of screw 120 aligns with protrusion 206, thereby permitting actuation of firing lever 202, i.e., pivotal movement of firing lever 220 about pivot member 208a towards handle assembly 20. Firing trigger 202 further includes a first opening 201a, a second opening 201b, a notch 201c and an indicator member 209. First opening 201a in firing trigger 202 is configured to receive a pin 208b for pivotally connecting firing lever 202 with firing link 210. Second opening 201b in firing trigger 202 is configured to receive a pin 208c for pivotally connecting firing lever 202 with safety link 260. As will be discussed in further detail below, notch 201c is configured to engage a safety pin 268 connected to trigger lock 260 to retain safety link 260 in an unlocked position. As will also be discussed in further detail below, indicator member 209 is positioned adjacent first opening 201a and is configured to engage an indicator member 218 formed on firing link 210 to provide an audible and/or tactile indication to a user as stapling device 10 is fired.

[0080] Still referring to FIG. 17, firing link 210 includes a distal end 212 pivotally secured to trigger 202 by a pivot member 208b received through opening 201a. A second end 214 of firing link 210 is pivotally secured within slot 31 (FIG. 7) formed on each internal wall of housing 20 by pivot member 216. Pivot member 216 is free to move vertically within slots 31. Although not shown, it is contemplated that a spring may be supported within housing 20 to urge pivot member 216 towards the bottom of slot 31. A more detailed description of a spring configured for supporting pivot member 216 is provided in the Milliman Ί87 patent, the content of which was previously incorporated by reference. Indicator member 218 is formed on distal trigger 202 during firing of stapling device 10.

[0081] As noted above, pusher linkage 220 includes an elongated pusher tube 230, a pusher link 240 and a pusher end tube 250. A pair of extensions 232 extends radially outwardly from proximal end 230a of elongated pusher tube 230. Extensions 232 are dimensioned to slide along channel 33 (FIG. 7) formed along each internal wall of housing 20 to maintain proper alignment of pusher linkage 220 within housing 20 during firing of stapling device 10. Proximal end 230a of elongated pusher tube 230 further includes a pair of indicator members 234 configured for viewing through window 50a of position indicator 50 formed in base 41 of chassis 40 when elongated pusher tube 230 is in a fully advanced position, e.g., upon completion of the firing stroke of stapler 10. Proximal end 230a of pusher tube 230 defines an elongated channel 233 configured to receive indicator member 122 of approximation assembly 100 when screw 120 of approximation assembly 100 is received within elongated pusher tube 230. Spring 235 is received about proximal end 230a of elongated pusher tube 230 adjacent extensions 232. As will be discussed in further detail below, spring 235 is configured to bias pusher linkage 220 proximally to a retracted position.

[0082] With continued reference to FIG. 17, distal end 230b of pusher tube 230 includes a pair of flanges 236a, 236b each defining an opening 235a, 235b, respectively. Each of openings 235a, 235b is configured to receive a pivot pin 238a, 238b, respectively, to pivotally secure a proximal end 240a of pusher link 240 with distal end 230b of elongated pusher tube 230.

[0083] With reference to FIG. 16-20, pusher link 240 includes an elongated member defining a channel 241 (FIG. 20) extending substantially the length thereof. As shown, pusher link 240 may be slightly curved along the length thereof. As will be discussed in further detail below, channel 241 is configured to receive screw extension 130 of approximation assembly 100 therethrough. Proximal end 240a of pusher link 240 includes a first pair of flanges 242a, 242b each defining an opening 243a, 243b sized to receive respective pivot pin 238a, 238b for pivotally connecting pusher link 240 and elongated pusher tube 230. A distal end 240b of pusher link 240 includes a second pair of flanges 244a, 244b, each defining an opening 245a, 245b sized to receive a pivot pin 248a, 248b, respectively, for pivotally connecting pusher link 240 and pusher end tube 250. Pusher link 240 may include one or more support members or spacers 246 (FIG. 20) extending within channel 241 for supporting screw extension 130 as screw extension 130 is advanced and/or retracted relative to pusher linkage 220 and/or as pusher linkage 220 is advanced and retracted relative to screw extension 130.

[0084] A proximal end 250a of pusher tube 250 includes a pair of flanges 252a, 252b each defining an opening 253a, 253b configured for receiving respective pivot pins 248a, 248b for pivotally connecting pusher tube 250 with pusher link 240. A distal end 250b of pusher end tube 250 is configured to selectively engage a proximal end of a pusher back 310 of staple assembly 300 (FIG. 1). In particular, distal end 250b includes an enlarged portion 254 having a distal facing surface 254a and a distally extending annular flange 256. Extending radially outward from annular flange 256 is a pair of tabs 256a (FIG. 16). As will be discussed in further detail below, tabs 256a are configured to selectively engage a threaded end of pusher back 310. Distal end 250b of pusher end tube 250 further includes spacers 258 extending radially outward therefrom to maintain pusher end tube 250 centered within distal end 60b of outer tube 60.

[0085] With reference back to FIG. 17, as noted above, staple pusher assembly 200 may optionally include trigger lock 260. Trigger lock 260 includes a first end 262 defining a first pair of openings 263 and a second end 264 defining a second pair of openings 265. First openings 263 are configured to receive pivot pin 208c for pivotally connecting trigger lock 260 with firing trigger 202. Second openings 265 are configured to receive pivot pin 268 for selectively connecting trigger lock 260 with clip 32 formed in housing 20. As will be discussed in further detail below, trigger lock 260 prevents movement of firing trigger 202 relative to housing 20, thereby preventing firing of stapling device 10.

[0086] Staple assembly 300 will now be described in detail with respect to FIGS. 21-26.

Referring initially to FIG. 21, staple assembly 300 includes a shell 302, a pusher back 310, a cylindrical knife 320 and a staple guide 330. Shell assembly 302 includes an outer housing portion 304 and an inner guide portion 306. Outer housing portion 304 defines a throughbore 305 and includes a distal cylindrical section 304a, a central conical section 304b and a proximal cylindrical section 304c. Distal cylindrical section 304a includes a slot 305a and a plurality of recesses 305b. Slot 305a is configured to receive a protrusion 332 formed on staple guide 330 to properly align staple guide 330 with pusher back 310. Recesses 305b are configured for engagement with tabs 334 formed on staple guide 330 for securing staple guide 330 to staple back 310. In some embodiments, a plurality of openings 307 is formed in conical section 304b to permit fluid and tissue passage during operation of stapling device 10.

[0087] With reference to FIGS. 22 and 24, proximal cylindrical section 304c of shell 302 includes a thread 308 formed about an inner surface thereof. Thread 308 is configured to selectively engage tabs 68 (FIG. 24) formed on distal end 64 of outer tube 60. As will be discussed in further detail below, the threaded engagement of shell 302 and outer tube 60 permits separation of staple assembly 300 from outer tube 60. In this manner, shell 302 of staple assembly 300 may be removed from surgical device 10 subsequent to use and stapling device 10 may be reloaded with another staple assembly 300 and reused.

[0088] Referring to FIGS. 21, 23 and 24, pusher back 310 includes a central throughbore

311 which is slidably positioned about inner guide portion 306 of shell 302. Pusher back 310 includes a distal cylindrical section 310a which is slidably positioned within distal cylindrical section 304c of shell 304, a central conical section 310b and a proximal smaller diameter cylindrical section 310c. Proximal cylindrical section 310c of pusher back 310 includes a thread

312 (FIG. 24) which is configured to selectively engage distal end 250b of pusher end tube 250 of pusher assembly 220 of stapling assembly 200. In particular, thread 312 is configured to receive tabs 256a formed on annular flange 256 extending from distal end 250b of pusher end tube 250 (FIG. 26). Rotation of pusher back 310 relative to pusher end tube 250 causes engagement/disengagement of tabs 256a from thread 218. In this manner, pusher back 310 may be readily attached or separated from staple pusher assembly 200 of surgical device 10 simultaneously with the attachment and separation of shell 302 from outer tube 60 to permit replacement of staple assembly 300.

[0089] With continued reference to FIG. 21, distal cylindrical section 310a of pusher back 310 includes a plurality of distally extending fingers 314 dimensioned to be slidably received within slots 331 formed in staple guide 330 to eject staples "S" therefrom. Distal ends 314a of fingers 314 define a groove for engaging staples "S". Cylindrical knife 320 is retained within central throughbore 311 of pusher back 310 by a pair of tabs 321. Alternately, knife 320 may be retained within pusher back 310 using adhesives, crimping, pins, etc. A distal end of knife 320 includes a circular cutting edge 322. A rigid bushing 340 is supported in the proximal end of inner guide portion 306 of shell 302. Bushing 340 defines a throughbore dimensioned to slidably receive anvil retainer 140 and center rod 86 of anvil assembly 80 (FIG. 1).

[0090] As will be discussed in further detail below, in operation, when pusher linkage

220 is advanced distally in response to actuation of firing trigger 202, pusher back 310 is advanced distally within shell 302. Advancement of pusher back 310 advances fingers 314 through slots 331 of staple guide 330 to advance staples "S" positioned within slots 331 and eject staples "S" from staple guide 330 into staple deforming pockets 97 of anvil 88 of anvil assembly 80 (FIG. 27). Since knife 320 is secured to pusher back 310, knife 320 is also advanced distally to core tissue as will be described in more detail below.

[0091] Anvil assembly 80 will now be described with reference to FIGS. 27 and 28.

Anvil assembly 80 is substantially similar to the anvil assembly disclosed in the Ί06 patent, the content of which has been previously incorporated herein by reference in its entirety. Therefore the anvil assembly 80 will only be described to the extent necessary to fully disclose the aspects of the present disclosure. A more detailed description of anvil assembly 80 is provided in the Ί06 patent.

[0092] Briefly, anvil assembly 80 includes an anvil head assembly 82 which is pivotally supported on an anvil center rod assembly 84. Anvil center rod assembly 84 includes anvil center rod 86 which defines a bore 81 defined by a plurality of flexible arms 88. Bore 81 is dimensioned to receive anvil retainer 140. The distal ends of each of flexible arms 88 include an internal shoulder (not shown) dimensioned to releasably engage anvil retainer 140. Bushing 340 provides lateral support for flexible arms 88 of center rod 86 when the anvil assembly 80 has been approximated to prevent outward movement of arms 88 after arms 88 have been withdrawn into bushing 340 to prevent disengagement of anvil assembly 80 from anvil retainer 140. In the unapproximated position, flexible arms 88 of center rod 86 are positioned externally of bushing 340 to permit removal of anvil assembly 80 from retainer 140. A plurality of splines 92 are formed about center rod 86. Center rod 84 also includes an annular recessed portion 85 to facilitate grasping of anvil assembly 80 by a surgeon with a grasper.

[0093] The operation of surgical stapling device 10 will now be described in detail with reference to FIGS. 29-41. With reference initially to FIGS. 29-33, surgical stapling device 10 is illustrated in an unapproximated or open position prior to attachment of anvil assembly 80 to anvil retainer 140 of approximation assembly 100. In the unapproximated or open position, screw 120 of approximation assembly 100 is in a distal-most position. A visual indication that stapling device 10 is in the unapproximated position is provided by the positioning of first indicator 122a of indicator member 122 formed on screw 120 under window 50a of position indicator 50 formed in chassis 40 of housing 20. As discussed above, surgical stapling device 10 includes spring 235 for biasing linkage assembly 220 of staple pusher assembly 200 proximally. In particular, spring 235 is disposed between flange member 63 formed on proximal end 62 of outer tube 60 and extensions 232 formed on proximal end 232 of elongated pusher tube 230. As discussed above, spring 235 is configured to urge pusher linkage 220 to its proximal-most position. As seen in FIG. 31, staple pusher assembly 200 is prevented from being actuated by engagement of protrusion 206 of trigger handle 202 with screw 120 of approximation assembly 100. Staple pusher assembly 200 is further prevented from being actuated by engagement of trigger lock 260 with housing 20.

[0094] As discussed above, anvil assembly 80 (FIGS. 27 and 28) is attached to surgical stapling device 10 by engaging center rod 86 of anvil assembly 80 with anvil retainer 140. In particular, anvil retainer 140 is received with bore 81 of center rod 86 of anvil assembly 80. Flexible arms 88 deflect outwardly to accommodate center rod 86. Center rod 86 is advanced onto anvil retainer 140 until internal shoulder (not shown) of flexible arms 88 passes over annular protrusion 146 (FIG. 12) formed on anvil retainer 140. At this point, resilient legs 88 releasably engage anvil retainer 140. The position of the remaining components of stapling device are not affected by attachment of anvil assembly 80 to anvil retainer 140 and remain as described above and shown in FIGS. 29-33.

[0095] FIGS. 34-38 illustrate surgical stapling device 10 during approximation of anvil assembly 80 and staple assembly 300 (FIG. 38). As discussed above, anvil assembly 80 (FIG. 1) is moved to the approximated or closed position by rotating rotation knob 102 in the direction indicated by arrow "A" (FIG. 34). Rotation of knob 102 causes cylindrical sleeve 110 to rotate to move ball 118a along helical channel 121 of screw 120. Movement of ball 118a relative to helical channel 121 causes screw 120 to translate proximally within sleeve 110, as indicated by arrow "B" (FIG. 34). Distal end 120a of screw 120 is connected to screw extension 130 which is fastened at its distal end to anvil retainer 140. As such, retraction of screw 120 within sleeve 110 is translated into proximal movement of anvil retainer 140 and anvil assembly 80. It is noted that when anvil assembly 80 is approximated, flexible legs 88 of center rod 86 are drawn into bushing 340 to lock legs 88 onto anvil retainer 140. Knob 102 of approximation assembly 100 is rotated until anvil head assembly 82 of anvil assembly 80 is disposed adjacent staple guide 330 of staple assembly 300 to retain tissue "T" (FIG. 38) therebetween.

[0096] In the approximated position, recess 125 formed in screw 120 of approximation assembly 100 is aligned with protrusion 206 formed on firing trigger 202 of staple pusher assembly 200 to permit actuation of firing trigger 202 of stapling device 10. In addition, when in the approximated position, second indicator 122b of indicator member 122 formed on screw 120 of approximation assembly 100 is aligned with window 50a of position indicator 50, thereby providing a visual indication to a user that anvil assembly 80 and staple assembly 300 have been fully approximated.

[0097] Prior to the firing of stapling device 10, trigger lock 260 (FIG. 34) is disengaged from housing 20 to enable movement of firing trigger 202 relative to housing 20. Specifically, second end 264 of trigger lock 260 including safety pin 268 is disengaged from latch 32 formed in housing 20 and is secured within notch 201c formed in firing trigger 202 to prevent inadvertent movement of trigger lock 260 during firing of stapling device 10 (FIG. 1). As noted above, in the approximated position, recess 125 formed in screw 120 of approximation assembly 100 is aligned with protrusion 206 formed on firing trigger 202 of staple pusher assembly 200, thereby permitting pivotal actuation of trigger handle 202.

[0098] With reference now to FIGS. 39-41, surgical stapling device 10 (FIG. 1) is illustrated during the firing stroke of firing trigger 202. As trigger 202 is compressed towards housing 20 in the direction indicated by arrow "D" (FIG. 39), pivot member 216 engages an abutment surface 154 on screw stop 150 and firing trigger 202 is pushed distally. During movement of firing trigger 202, indicator member 209 (FIG. 17) formed on firing trigger 202 engages indicator member 218 (FIG. 17) formed on firing link 210 to produce an audible and/or tactile indication to the user that firing trigger 202 has been actuated. As discussed above, the distal end of firing trigger 202 is connected to the proximal end of elongated pusher tube 230 of pusher linkage 220. Accordingly, as firing trigger 202 is moved distally, elongated pusher tube 230, pusher link 240 and pusher end tube 250 of pusher linkage 220 are moved distally in the direction indicated by arrow "E" (FIG. 39) to effect advancement of pusher back 310 within staple assembly 300. A visual indication that pusher linkage 220 has been fully advanced is provided by the alignment of indicator member 234 formed on elongated pusher tube 230 with window 50a of position indicator 50. As pusher back 310 is advanced within staple assembly 300, fingers 314 of pusher back 310 engage and eject staples "S" from staple guide 330. Cylindrical knife 320 is moved concurrently with pusher back 310 such that knife 320 moves into engagement with a cutting ring 94 (FIG. 27) and a backup plate 96 (FIG. 27) of anvil assembly 80.

[0099] Anvil assembly 80 may be unapproximated from staple assembly 300 and separated from stapling device 10 in a reverse manner. In particular, firing trigger 202 is pivoted away from housing 20 to retract pusher linkage 202 of staple pushing assembly 200, thereby retracting pusher back 310 of staple assembly 300. Approximation knob 102 is then turned in an opposite direction from that required to approximate anvil assembly 80 to move anvil head assembly 82 of anvil assembly 80 away from staple assembly 300. Once anvil head assembly 82 of anvil assembly 80 is sufficiently spaced from staple assembly 300, anvil head assembly 82 tilts to permit removal of stapling device 10 from within the patient (not shown). Anvil head assembly 82 of anvil assembly 80 is further separated from staple assembly 300 by continued rotation of approximation knob 102 to withdraw legs 88 anvil assembly 80 from within bushing 340 to unlock anvil assembly 80 from anvil retainer 140 and permit separation of anvil assembly 80 from stapling device 10.

[00100] Once anvil assembly 80 is separated from stapling device 10, staple assembly 300 can be disengaged from outer tube 60 and pusher end tube 250 of approximation assembly 200 in the manner discussed above. In particular, staple assembly 300 is rotated relative to outer tube 60 to unthread shell 302 from outer tube 60 and pusher back 310 from pusher end tube 250. During a procedure on a patient, it is envisioned that stapling device 10 may be used multiple times by replacing staple assembly 300 after each use.

[00101] Stapling device 10 (FIG. 1) is used to perform circular anastomoses. Typically, circular anastomoses are required during procedures for removing a portion of a diseased vessel such as the colon or the intestine. During such a procedure, the diseased portion of the vessel is removed from the diseased vessel and the end portions of the remaining first and second vessel sections are joined together using the stapling device 10. Circular anastomoses are also required in a variety of other surgical procedures such as in gastric bypass procedures.

[00102] The use of stapling device 10 will now be described. In use, stapling device 10 is operated in a manner substantially similar to a traditional circular stapler. Prior to removing a diseased vessel portion from a diseased vessel, anvil assembly 80 (FIG. 1) with a removable trocar (not shown) attached thereto is positioned in the first vessel section on a first side of the diseased portion. A removable trocar which is suitable for use with the anvil assembly 80 is disclosed in the Gresham '444 patent which, as discussed above, is incorporated herein by reference in its entirety. After the diseased vessel portion is removed and open ends of the first and second vessel sections have been sutured, the distal end of surgical device 10 is positioned in the second vessel section on the other side of the diseased portion which has been removed. At this time, the removable trocar is pushed through the suture line in the end of the first vessel section and removed from anvil assembly 80. Next, the end of anvil retainer 140 is pushed through the suture line in the second vessel section and is joined to center rod 84 of the anvil assembly 80. Stapling device 10 may now be approximated and fired in the manner discussed above to join the ends of the first and second vessel sections and core out any tissue obstructing the vessel lumen (FIG. 41). [00103] As discussed above, stapling device 10 is configured to be sterilized to facilitate use of stapling device 10 on a plurality of patients on different occasions. To permit reuse of stapling device 10, the components of stapling device 10 must either be disposed of or sterilized. Following use, staple assembly 300 is separated from body portion 14 (FIG. 1) in the manner discussed above. Next proximal and distal ferrules 70, 72 are disengaged from proximal and distal threads 26, 28, respectively, of housing 20 to permit opening of housing sections 20a, 20b of housing 20. Housing sections 20a, 20b may remain attached to chassis 40. Alternatively, housing sections 20a, 20b may be disengaged from chassis 40 by disengaging pins 30 from slots 25a, 25b. Staple pusher assembly 200 is then separated from approximation assembly 100 to permit sterilization thereof. Approximation assembly 100 is then sufficiently disassembled to permit disengagement from proximal and distal flanges 52, 54 of chassis 40 to permit sterilization of approximation assembly 100. Alternatively, approximation assembly 100 may remain attached to chassis 40 during sterilization.

[00104] Once all of the components are sterilized, stapling device 10 may be reassembled, with a fresh staple assembly 300 secured to the components of stapling device 10. It is noted that because staple assembly 300 can be easily separated from outer tube 60 and approximation assembly 100 by rotating staple assembly 300 relative to outer tube 60 and replaced with a fresh staple assembly 300, stapling device 10 may be used to perform multiple operations during a single surgical procedure on a single patient without sterilizing stapling device 10. More specifically after a first stapling procedure has been performed on a patient by ejecting a first circular array of stapler from a first staple assembly 300, the first staple assembly 300 can be replaced with a second staple assembly 300 to perform a second stapling procedure on the patient. [00105] A surgical stapling device having a staple pushing assembly and staple assembly according to an alternative embodiment of the present disclosure will now be described with reference to FIGS. 42-45. Staple pushing assembly 200' and staple assembly 300' (FIG. 45) of stapling device 10' (FIG. 43) are substantially similar in structure and function to staple pusher assembly 200 and staple assembly 300 of stapling device 10 described above and, therefore, will only be described as relates to the differences therebetween. Similar structure and features will be designated by a prime mark.

[00106] With initial reference to FIGS. 42-44, approximation assembly 200' includes a firing trigger 202' and a trigger lock 260'. A first end 262' of trigger lock 260' is pivotally secured to firing trigger 202'. Firing trigger 202' is configured to selectively retain trigger lock 260' in an extended position, as shown in FIG. 43. A second end 264' of trigger lock 260' includes a notch 264a configured to engage housing 20' of stapling device 10' when trigger lock 260' is in the extended position. Firing trigger 202' is further configured to permit pivoting of trigger lock 260', as indicated by arrow "F" in FIG. 44, prior to firing of stapling device 10'. Firing trigger 202' may also be configured to retain trigger lock 260' in a stored position to prevent inadvertent movement of trigger lock 260' during firing of stapling device 10'.

[00107] With particular reference back to FIG. 42, a reduced diameter portion 256' extending from an enlarged portion 254' formed on a distal end 250b' of an pusher end tube 250' of pusher linkage 220' includes a pair of knobs 256a' extending radially outward therefrom. As will be discussed in further detail below, knobs 256a' are configured to selectively engage pusher back 310' of staple assembly 300'. A ridge 258' extends about enlarged portion 254' for maintaining pusher end tube 250' axially aligned with the outer tube (not shown) of stapling device 10'. [00108] Turning now to FIGS. 45-47, staple assembly 300' includes a shell 302' and a pusher back 310'. Shell 302' includes a reduced diameter extension 308' on a proximal end thereof configured for operable connection with the outer tube (not shown) of stapling device 10' (FIG. 43). Reduced diameter portion 308' includes a pair of tabs 309' extending radially outward therefrom. Tabs 309' are configured to engage an internally threaded distal end (not shown) of the outer tube (not shown). Alternatively, tabs 309 are configured to be received within openings (not shown) formed in the outer tube (not shown). Pusher back 310' defines a pair of longitudinal slots 315 formed on a proximal end thereof. A notch 317 is formed perpendicular to each of slots 315 in the proximal end of pusher back 310'. Each of notches 317 are configured to selectively receive knobs 256a' (FIG. 42) formed on reduced diameter portion 256' of pusher end tube 250'. In this manner, pusher back 310' is connected with pusher end tube 250' in a manner commonly referred to as a bayonet coupling. As noted above, surgical stapling device 10' operates in a manner similar to surgical stapling device 10'. Accordingly, surgical stapling device 10' offers the same or similar benefits of surgical stapling device 10 as describe above.

[00109] It will be understood that various modifications may be made to the embodiments disclosed herein. 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. For example, although the description refers exclusively to staples, it is envisioned that staples may include different types of tissue fasteners including two-part fasteners. In a stapling device for applying two-part fastener, the anvil assembly of the stapling device would support one part of each two-part fastener.

Claims

WHAT IS CLAIMED IS:

1. A surgical stapling device comprising:

a housing;

an outer tube extending distally from the housing having a proximal end configured for operable connection with the housing and a distal end;

a disposable staple assembly releasably supported on a distal end of the outer tube, the staple assembly including a shell supporting a pusher back, and a plurality of fasteners, the pusher back being axially movable within the shell to eject the plurality of fasteners from the disposable staple assembly, the shell being adapted to be rotabably connected to the outer tube; an approximation assembly operably received within the housing, the approximation assembly including an anvil retainer releasably engageable with an anvil assembly, the approximation assembly being operable to approximate the anvil assembly and the staple assembly; and

a staple pusher assembly extending from within the housing to the distal end of the outer tube, the staple pusher assembly adapted to be rotatably connected to the pusher back of the disposable staple assembly and operable to effect axial movement of the pusher back within the shell.

2. The surgical stapling device of claim 1, wherein the approximation assembly and the staple pusher assembly are releasably secured within the housing.

3. The surgical stapling device of claim 1, wherein the housing includes a first housing section, a second housing section and a chassis pivotally connect to each of the first and second housing sections.

4. The surgical stapling device of claim 3, wherein the first and second housing sections are configured to be separated to provide access to an interior of the housing.

5. The surgical stapling device of claim 1, wherein the staple pusher assembly is configured to be sterilized.

6. The surgical stapling device of claim 1, wherein the staple pusher assembly includes a pusher linkage for effecting ejection of the staples from the staple assembly.

7. The surgical stapling device of claim 1, wherein the outer tube includes at least one tab and the shell includes thread positioned to engage the at least one tab to releasably secure the shell to the outer sleeve.

8. The surgical stapling device of claim 9, wherein the at least one tab includes two tabs configured to engaged the thread formed on the shell.

9. The surgical stapling device of claim 1, wherein the pusher back includes thread and the staple pusher assembly includes a pusher defining at least one tab position to engage the at least one tab to releasably secure the pusher back to the pusher.

10. The surgical stapling device of claim 9, wherein the at least one tab includes two tabs configured to engaged the thread formed on the pusher.

11. A method comprising the steps of:

positioning a surgical stapler within a patient such that tissue to stapled is disposed between an anvil assembly and a first staple assembly, the first staple assembly including a first circular array of staples;

performing a first stapling procedure by ejecting the first circular array of staples from the first staple assembly;

removing the surgical stapler from within the patient;

replacing the first staple assembly of the surgical stapler with a second staple assembly, the second staple assembly including a second circular array of staples;

repositioning the surgical stapler within the patient; and

performing a second stapling procedure by ejecting the second circular array of staples from the second staple assembly.

12. The method of claim 11, wherein the step of replacing the first staple assembly includes rotating the first staple assembly in a first direction relative to an elongated body portion of the surgical stapler to disconnect the first staple assembly from the elongated body portion.

13. The method of claim 12, wherein the step of replacing the first staple assembly further includes rotating the second staple assembly in a second direction relative to the elongated body portion to connect the second staple assembly with the elongated body portion.