WO2014139327A1

WO2014139327A1 - Surgical stapling apparatus

Info

Publication number: WO2014139327A1
Application number: PCT/CN2014/000263
Authority: WO
Inventors: Kin Ying LEE
Original assignee: Covidien Lp; Covidien (China) Medical Devices Technology Co., Ltd
Priority date: 2013-03-15
Filing date: 2014-03-13
Publication date: 2014-09-18
Also published as: CN104042290A

Abstract

A surgical stapling apparatus (10) includes a handle (20), a body (30), a firing assembly (300) and a stapling assembly (100). The body (30) extends distally from the handle (20) and includes an engagement member (36) that defines a slot (165) and is coupled to a distal end of the body (30). The firing assembly (300) includes a trigger (24) and a link (330) that is configured for translation through the body (30) in response to actuation of the trigger (24). The stapling assembly (100) is configured to house a plurality of surgical staples (600) and includes an outer shell (142) having a tab (152). The engagement member (36) is rotatable relative to the body (30) and the stapling assembly (100) to releasably engage the tab (152) within the slot (165), thereby securing the stapling assembly (100) at the distal end of the body (30) and operably coupling the stapling assembly (100) to the link (330) such that, in response to distal advancement of the link (330), the plurality of surgical staples (600) are ejected from the stapling assembly (100).

Description

SURGICAL STAPLING APPARATUS

BACKGROUND

Technical Field

[0001] The present disclosure relates generally to a surgical stapling apparatus for applying surgical staples to body tissue and, more particularly, to a surgical stapling apparatus for performing circular anastomosis of hollow tissue structures.

Background 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. 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. An example of such a circular anastomosis apparatus is described in U.S. Patent No. 7,857,187 to Milliman, the entire contents of which is hereby incorporated by reference herein in its entirety.

[0004] Typically, surgical stapling apparatus for performing circular anastomosis procedures are disposable after a single use. A need exists for a surgical stapling apparatus that includes reusable components and is configured to facilitate sterilization.

SUMMARY

[0005] A surgical stapling apparatus provided in accordance with one aspect of the present disclosure includes a handle portion, an elongated body portion, a firing assembly, and a replaceable stapling assembly. The elongated body portion extends distally from the handle portion and includes an engagement member rotatably coupled to the elongated body portion towards a distal end thereof. The engagement member defines an engagement slot. The firing assembly includes a firing trigger and a firing link extending at least partially through the elongated body portion. The firing link is configured for distal translation through the elongated body portion in response to actuation of the firing trigger. The replaceable stapling assembly is configured to house a plurality of surgical staples therein. The replaceable stapling assembly includes an outer shell having an engagement tab. The engagement member is rotatable relative to the elongated body portion and the replaceable stapling assembly to releasably engage the engagement tab within the engagement slot, thereby securing the replaceable stapling assembly at the distal end of the elongated body portion and operably coupling the replaceable stapling assembly to the firing link such that, in response to distal advancement of the firing link, the plurality of surgical staples are ejected from the replaceable stapling assembly. [0006] In some embodiments, the firing trigger extends from the handle portion and is coupled to the firing link. In such embodiments, the firing trigger is selectively actuatable to translate the firing link distally through the elongated body portion.

[0007] In some embodiments, an approximation assembly is provided. The approximation assembly can include a drive member configured to extend distally from the elongated body potion and the replaceable stapling assembly. The distal end of the drive member can be configured to releasably engage an anvil assembly.

[0008] In some embodiments, an approximation knob extending from the handle portion is provided, coupled to the drive member and selectively actuatable to move the anvil assembly between a spaced-apart position and an approximated position relative to the replaceable stapling assembly.

[0009] In some embodiments, the drive member defines a helical channel and the approximation knob is coupled to a pin disposed within the helical channel such that rotation of the approximation knob effects translation of the drive member.

[0010] In some embodiments, a biasing member is disposed between the elongated body portion and the engagement member to bias the engagement member proximally.

[0011] In some embodiments, the engagement tab is retained in engagement within the engagement slot under the bias of the biasing member.

[0012] In some embodiments, the engagement tab further includes an engagement nub and the engagement slot further includes an engagement notch. The engagement nub can be configured to engage the engagement notch to secure the replaceable stapling assembly at the distal end of the elongated body portion and operably couple the replaceable stapling assembly to the firing link. [0013] In some embodiments, the replaceable stapling assembly includes a cartridge assembly disposed within the outer shell. The cartridge assembly may include a pusher including a plurality of pusher fingers configured to support the plurality of surgical staples and a staple guide member configured to guide ejection of the surgical staples from the replaceable stapling assembly.

[0014] In some embodiments, the handle portion is formed from first and second handle sections that are releasably engagable with one another.

[0015] In some embodiments, first and second handle sections are releasably engaged with one another via at least one of a hook assembly and a plunger assembly.

[0016] In accordance with another aspect of the present disclosure, a stapling apparatus is provided which includes a handle portion, a curved elongated body potion, a stapling assembly, and an approximation assembly. The curved elongated body portion extends distally from the handle portion. The stapling assembly is disposed at a distal end of the curved elongated body portion and is configured to house a plurality of surgical staples therein. The approximation assembly includes a drive member configured to engage an anvil assembly at a distal end of the drive member. The drive member is configured for selective translation through and relative to the curved elongated body portion and the stapling assembly to move the anvil assembly relative to the stapling assembly. The drive member includes a pair of opposed flexible portions configured to facilitate translation of the drive member through the curved elongated body portion. The opposed flexible portions are engaged to one another along at least a portion of lengths thereof via a plurality of pins arranged so that heads of the pins are alternatingly disposed on either side of the flexible portions along the lengths thereof. [0017] In some embodiments, an approximation knob extending from the handle portion is provided, coupled to the drive member and selectively actuatable to move the anvil assembly between a spaced-apart position and an approximated position relative to the stapling assembly.

[0018] In some embodiments, the drive member defines a helical channel and the approximation knob is coupled to a pin disposed within the helical channel such that rotation of the approximation knob effects translation of the drive member.

[0019] In some embodiments, first and second fiat bands form the opposed flexible portions of the drive member.

[0020] In some embodiments, the drive member further includes a proximal shaft portion.

In such embodiments, the opposed flexible portions are engaged to and extend distally from a distal end of the proximal shaft portion.

[0021] In some embodiments, the drive member includes a distal anvil retainer configured to engage the anvil assembly. In such embodiments, the opposed flexible portions can be engaged to the anvil retainer at distal ends of the opposed flexible portions.

[0022] In some embodiments, a firing assembly including a firing trigger and a firing link is provided, the firing link disposed about the drive member and extending at least partially through the curved elongated body portion. The firing link is configured for distal advancement through the elongated body portion in response to actuation of the firing trigger to eject the plurality of surgical staples from the stapling assembly.

[0023] In accordance with another aspect of the present disclosure, a surgical stapling apparatus is provided including a handle portion formed from first and second handle sections, an elongated body portion extending distally from the handle portion, a stapling assembly disposed at a distal end of the elongated body portion that is configured to house a plurality of surgical staples therein, an approximation assembly, and a firing assembly. The approximation assembly includes an approximation actuator extending from the handle portion and a drive member coupled to the approximation actuator. The drive member is configured to engage an anvil assembly at a distal end thereof. The drive member is further configured for translation through the elongated body portion in response to actuation of the approximation actuator to move the anvil assembly relative to the stapling assembly. The firing assembly includes a firing trigger extending from the handle portion and a firing link coupled to the firing trigger. The firing link is configured for distal translation through the elongated body portion in response to actuation of the firing trigger to eject the plurality of surgical staples from the stapling assembly. The first and second handle sections are releasably engagable with one another to house at least a portion of the approximation assembly and at least a portion of the firing assembly therein. The first and second handle sections are releasably engagable with one another via at least one hook and recess engagement and at least one plunger and protrusion engagement.

[0024] In some embodiments, the hook and recess engagement includes a hook assembly coupled to one of the first and second handle sections and a recess defined within the other of the first and second handle sections. The hook assembly can include a hook and a biasing member configured to bias the hook into engagement with the recess upon approximation of the first and second handle sections.

[0025] In some embodiments, the plunger and protrusion engagement includes a pair of opposed, inwardly-biased plungers disposed on one of the first and second handle sections, and a protrusion disposed on the other of the first and second handle sections. The plungers can be configured to bias inwardly into engagement with the protrusion upon approximation of the first and second handle sections. [0026] In some embodiments, the first and second handle sections each include first channels configured to receive a portion of the drive member to guide translation of the drive member.

[0027] In some embodiments, the first and second handle sections each include second channels configured to receive a portion of the firing link to guide translation of the firing link.

[0028] A method of surgery provided in accordance with the present disclosure includes a surgical stapling apparatus including a handle portion formed from first and second handle sections releasably engaged to one another, an elongated body portion, a firing assembly, an approximation assembly, an anvil assembly, and a first replaceable stapling assembly. The method further includes inserting the surgical stapling apparatus into an internal surgical site, actuating the approximation assembly to clamp tissue between the first replaceable stapling assembly and the anvil assembly, actuating the firing assembly to eject the first plurality of surgical staples from the first replaceable stapling assembly, through the clamped tissue, and into the anvil assembly to form the first plurality of surgical staples about the clamped tissue, removing the surgical stapling apparatus from the internal surgical site, disengaging the first replaceable stapling assembly from the engagement member, and disengaging the first and second handle sections from one another.

[0029] In some embodiments, the method further includes disassembling the first and second handle sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly from one another; sterilizing the first and second housing sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly; reassembling the first and second handle sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly to one another; and engaging a second replaceable stapling assembly with the engagement member. The second replaceable stapling assembly preferably houses a second plurality of surgical staples therein.

[0030] In some embodiments, the method further includes inserting the surgical stapling apparatus into an internal surgical site, actuating the approximation assembly to clamp tissue between the second replaceable stapling assembly and the anvil assembly, and actuating the firing assembly to eject the second plurality of surgical staples from the second replaceable stapling assembly, through the clamped tissue, and into the anvil assembly to form the second plurality of surgical staples about the clamped tissue. See also, for example, U.S. Patent No. 7,857,187 to Milliman, previously incorporated by reference herein, U.S. Patent No. 6,945,444 to Gresham et al., the entire contents of which are incorporated by reference herein, and U.S. Patent 7,303,106 to Milliman et al., the entire contents of which are incorporated by reference herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various embodiments of the presently disclosed surgical stapling apparatus are described herein with reference to the drawings wherein:

[0032] FIG. 1 is a top, side, perspective view from the distal end of the presently disclosed surgical stapling apparatus;

[0033] FIG. 2 is a side view of the surgical stapling apparatus shown in FIG. 1 with the anvil assembly removed;

[0034] FIG. 3 is a top, side, perspective view from the proximal end of the surgical stapling apparatus shown in FIG. 1 with the anvil assembly removed; [0035] FIG. 4 is a side, perspective view of the handle portion of the surgical stapling apparatus of FIG. 1 wherein one of the handle sections has been removed to shown the internal components of the handle portion;

[0036] FIG. 5 is a transverse, cross-sectional view taken along section line 5-5 of FIG. 4;

[0037] FIG. 6 is a transverse, cross-sectional view taken along section line 6-6 of FIG. 4;

[0038] FIG. 7 is a transverse, cross-sectional view taken along section line 7-7 of FIG. 4;

[0039] FIG. 8 is an exploded, perspective view of the surgical stapling apparatus of FIG. i ;

[0040] FIG. 9 is a top, side, perspective view from the proximal end of the distal shell and cartridge assembly of the replaceable stapling assembly of the surgical stapling apparatus of FIG. 1 ;

[0041] FIG. 10 is an enlarged view of the area of detail indicated as "10" in FIG. 9;

[0042] FIG. 1 1 is an exploded, perspective view of the cartridge assembly and the distal shell of the replaceable stapling assembly of FIG. 9;

[0043] FIG. 12 is a top, side, perspective view from the proximal end of the distal shell of the replaceable stapling assembly of FIG. 9;

[0044] FIG. 13 is a side, perspective view from the distal end of the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0045] FIG. 14 is a side, perspective view from a proximal end of the firing assembly of the surgical stapling apparatus of FIG. 1 ;

[0046] FIG. 15 is an exploded, perspective view of the firing assembly of FIG. 14;

[0047] FIG. 16 is a top, side, perspective view of the approximation assembly of the surgical stapling apparatus of FIG. 1 ; [0048] FIG. 17 is an exploded, perspective view of the of the approximation assembly of

FIG. 16;

[0049] FIG. 18 is a side, perspective view of the inner assembly of surgical stapling apparatus of FIG. 1 ;

[0050] FIG. 19 is an exploded, perspective view of the inner assembly of FIG. 18;

[0051] FIG. 20 is a side, perspective, interior view of one of the handle sections of the handle portion of FIG. 4;

[0052] FIG. 21 is an enlarged view of the area of detail indicated as "21" in FIG. 20;

[0053] FIG. 22 is a top, perspective view from a proximal end illustrating engagement of the handle sections to one another to form the handle portion of FIG. 4;

[0054] FIG. 23 is an enlarged view of the area of detail indicated as "23" in FIG. 22;

[0055] FIG. 24 is an enlarged view of the area of detail indicated as "24" in FIG. 22;

[0056] FIG. 25 is a transverse, cross-sectional view taken along section line 25-25 of FIG.

23;

[0057] FIG. 26 is a longitudinal, cross-sectional view taken along section line 26-26 of

FIG. 23;

[0058] FIG. 27 is a side, perspective, view of the replaceable stapling assembly of FIG.

9 shown disengaged from the distal end of the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0059] FIG. 28 is a side, perspective, cut-away view of the replaceable stapling assembly of FIG. 9 shown disengaged from the distal end of the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ; [0060] FIG. 29 is a longitudinal, cross-sectional view of the replaceable stapling assembly of FIG. 9 shown disengaged from the distal end of the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0061] FIG. 30 is a longitudinal, cross-sectional, cut-away view of the replaceable stapling assembly of FIG. 9 shown disengaged from the distal end of the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0062] FIG. 31 is a side, perspective, view of the replaceable stapling assembly of FIG. 9 shown during initiation of engagement between the replaceable stapling assembly and the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0063] FIG. 32 is a side, perspective, cut-away view of the replaceable stapling assembly of FIG. 9 shown during initiation of engagement between the replaceable stapling assembly and the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0064] FIG. 33 is a side, perspective view of the replaceable stapling assembly of FIG. 9 shown during completion of engagement between the replaceable stapling assembly and the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0065] FIG. 34 is a longitudinal, cross-sectional view of the replaceable stapling assembly of FIG. 9 shown engaged to the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0066] FIG. 35 is a longitudinal, cross-sectional, cut-away view of the replaceable stapling assembly of FIG. 9 shown engaged to the outer tube of the elongated body portion of the surgical stapling apparatus of FIG. 1 ;

[0067] FIG. 36 is a longitudinal, cross-sectional view of the surgical stapling apparatus of

FIG. 1 ; [0068] FIG. 37 is an enlarged view of the area of detail indicated as "37" in FIG. 36;

[0069] FIG. 38 is an enlarged view of the area of detail indicated as "38" in FIG. 36;

[0070] FIG. 39 is a longitudinal, cross-sectional view taken along section line 39-39 of

FIG. 38

[0071] FIG. 40 is an enlarged view of the area of detail indicated as "40" in FIG. 39;

[0072] FIG. 41 is a longitudinal, cross-sectional view of the handle portion of the surgical stapling apparatus of FIG. 1 shown in a position corresponding to the approximated position of the surgical stapling apparatus;

[0073] FIG. 42 is a longitudinal, cross-sectional view of the distal end of the surgical stapling apparatus of FIG. 1 shown in the approximated position clamping tissue between the replaceable stapling assembly and the anvil assembly;

[0074] FIG. 43 is a longitudinal, cross-sectional view of the handle portion of the surgical stapling apparatus of FIG. 1 shown in a position corresponding to the fired position of the surgical stapling apparatus; and

[0075] FIG. 44 is a longitudinal, cross-sectional view of the distal end of the surgical stapling apparatus of FIG. 1 shown in the fired position after firing and forming staples about the clamped tissue.

DETAILED DESCRIPTION OF EMBODIMENTS

[0076] Embodiments of the presently disclosed surgical stapling apparatus 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 apparatus closer to the user and the term "distal" will refer to the portion of the apparatus further from the user. [0077] With general reference to FIGS. 1-44, an embodiment of the presently disclosed surgical stapling apparatus is shown identified by reference numeral 10. Surgical stapling apparatus 10 includes a proximal handle portion 20, an elongated central body portion 30, and a distal head portion 40. The length, shape and/or the diameter of any of handle portion 20, body portion 30, and/or head portion 40 may also be varied to suit a particular surgical procedure. With particular reference to FIGS. 4 and 8, proximal handle portion 20 includes a stationary handle 22, a firing trigger 24, and a rotatable approximation knob 26. Stationary handle 22 is formed from first and second releasably engagable handle sections 22a and 22b (see FIGS. 20-26) that cooperate to house the internal components of handle portion 20, e.g., the proximal components of approximation assembly 200 and firing assembly 300. Proximal handle portion 20 and the internal components thereof will be described in greater detail below.

[0078] With particular reference to FIGS. 1-4, and 8, elongated central body portion 30 of surgical stapling apparatus 10 includes a curved elongated outer tube 32, a proximal bushing 34, and a distal engagement shell 36. Outer tube 32 is configured to receive components of approximation assembly 200 (FIG. 8) and firing assembly 300 (FIG. 8). As will be discussed in further detail below, proximal bushing 34 is provided to facilitate releasable engagement of the proximal end of outer tube 32 with stationary handle 22 of handle portion 20 and engagement shell 36 is provided to facilitate releasable engagement of replaceable stapling assembly 100 with the distal end of outer tube 32.

[0079] With particular reference to FIGS. 1 , 8-13, and 18-19, distal head portion 40 of surgical stapling apparatus 10 includes an anvil assembly 400 (FIG. 1) that is releasably engagable with the distal end of approximation assembly 200 (FIG. 8), and a replaceable stapling assembly 100 that is releasably engagable with the distal end of elongated central body portion 30. Replaceable stapling assembly 100 (or portions thereof) is configured as a disposable component that is to be replaced with a new replaceable stapling assembly 100 (or portions thereof) after each firing. The remaining components of surgical stapling apparatus 10 are configured as reusable, sterilizable components, although one or more of these components may alternatively be configured as a disposable component. Distal head portion 40 will be described in greater detail below.

[0080] The various components of surgical stapling apparatus 10 described hereinbelow are configured to facilitate the assembly and disassembly of surgical stapling apparatus 10, thus facilitating the disposal and replacement of those components that are disposable and the sterilization and reassembly of those components that are reusable. The materials used to form the various components of surgical stapling apparatus 10 will depend upon the strength requirements of the particular component and the use requirements of the particular component, e.g., whether the component is reusable or disposable. The reusable components, for example, may generally be formed from thermoplastics including polycarbonates, and metals including stainless steel and aluminum, that are suited to withstand repeated sterilization procedures, e.g., autoclaving.

[0081] Referring to FIGS. 1 , 4-8, and 16-17, approximation mechanism 200 of surgical stapling apparatus 10 includes an approximation knob 26, a drive screw 220, a rotatable sleeve 230, first and second screw extensions 240 and 250 (FIG. 8), respectively, and an anvil retainer 260 (FIG. 8). Rotatable sleeve 230 (FIGS. 16-17) includes a substantially cylindrical hollow body portion 231 and a substantially cylindrical collar 232 that together define a central bore 233. Collar 232 has an annular groove 234 (FIG. 4) formed about the outer periphery thereof that is dimensioned to receive an inwardly extending flange 22c formed by the cooperating proximal ends of handle sections 22a and 22b of stationary handle 22 of handle portion 20 (see FIGS. 22- 24). The engagement between groove 234 and flange 22c axially fixes sleeve 230 relative to stationary handle 22 while permitting rotation of sleeve 230 relative to stationary handle 22. The proximal end of body portion 231 of rotatable sleeve 230 extends through an opening 22d in the proximal end of stationary handle 22. A pair of diametrically opposed elongated ribs 235 are positioned or formed on the outer surface of body portion 231. Approximation knob 26 includes a pair of internal slots 212 positioned to receive ribs 235 of sleeve 230 to rotatably fix sleeve 230 to knob 26 such that rotation of knob 26 effects similar rotation of sleeve 230. Greater or fewer ribs 235 and slots 212 may alternatively provided. Further, this configuration may be reversed, e.g., where ribs 235 are disposed on approximation knob 26 and slots 212 are defined within sleeve 230.

[0082] As shown in FIGS. 16-17, the proximal portion of screw 220 includes a helical channel 222 and is dimensioned to be slidably positioned within central bore 233 (FIG. 17) of rotatable sleeve 230. A tracking pin 224 extends through cylindrical collar 232 of sleeve 230 into helical channel 222 of screw 220. Tracking pin 224 includes a head 225 defining a pair of spaced-apart plates 225a, 225b. Head plates 225a, 225b are configured to surround a receiving plate 236a disposed within a recess 236 defined within cylindrical collar 232 of sleeve 230 to secure tracking pin 224 within sleeve 230 and inhibit tracking pin 224 from backing out. More specifically, once tracking pin 224 is inserted through collar 232, tracking pin 224 is rotated such that head plates 225a, 225b surround receiving plate 236a, thereby securing tracking pin 224 in position.

[0083] The distal end of screw 220 includes a transverse slot 226. First and/or second screw extensions 240 and 250 may each include at least one flexible band portion, such as flexible band portions 242 and 252, although other configurations are also contemplated. For example, in some embodiments, first and/or second screw extensions 240 and 250 contain alternating segments of flexible and non-flexible band portions. In some embodiments, first screw extension 240 or second screw extension 250 may contain a flexible band portion while the other one does not. The flexibility of the flexible band portion may be accomplished in any number of ways. For example, the flexible band portion may be constructed of a flexible material. In an embodiment, the flexible band portion may include a plurality of segments. In an embodiment, the flexible band portion may have material removed from it, for example in notches, to increase flexibility. The flexibility of band portions 242 and 252 permits translation of screw extensions 240 and 250 through curved elongated outer tube 32 of elongated body portion 30. The proximal end of each band portion 242 and 252 includes a respective hole 244 and 254 dimensioned to receive a pin 246 for securing the proximal end of screw extensions 240 and 250 within transverse slot 226 of screw 220. The band portion 242 and 252 of each screw extension 240 and 250 is dimensioned to be received within a transverse slot 262 formed in a proximal end of anvil retainer 260 to fasten anvil retainer 260 to the distal end of screw extensions 240 and 250. More specifically, a pair of pins 264 extends through the proximal end of anvil retainer 260 and band portions 240 and 250 to secure screw extensions 240 and 250 to anvil retainer 260. Alternately, other fastening techniques may be used to secure screw extensions 240, 250 to anvil retainer 260 and screw 220, e.g., friction fitting, welding, crimping, etc.

[0084] Each screw extension 240 and 250 includes a plurality of apertures 248 and 258

(FIG. 17), respectively, defined along the length of the respective screw extension 240 and 250. Apertures 248 and 258 are configured to align with one another for receipt of pins 249 therethrough to secure screw extensions 240 and 250 to one another. Each pin 249 includes a head 249a and a shaft 249b. Pins 249 are positioned such that shafts 249b extend through apertures 248 and 258 of screw extensions 240 and 250, respectively, and such that heads 249a are alternatingly disposed on either side of screw extensions 240 and 250. Heads 249a of pins 249 serve as spacers to guide translation of screw extensions 240, 250 through curved elongated outer tube 32 of elongated central body portion 30. By alternatively positioning heads 249a on either side of screw extensions 240 and 250, screw extensions 240 and 250 are maintained in substantially centered position within elongated outer tube 32 during translation therethrough (see FIGS. 32, 42, and 44).

[0085] With reference to FIGS. 8, 16, and 17, anvil retainer 260 includes a trocar portion

265a, a body portion 265b, and an attachment portion 265c. Trocar portion 265a includes a blunt trocar tip 267, although other configurations are also contemplated. Body portion 265b is substantially cylindrical and has a diameter which is larger than the diameter of trocar portion 265a. An annular protrusion 268 is disposed about body portion 265b of anvil retainer 260 and is configured to engage anvil assembly 400 (FIG. 1) to retain anvil assembly 400 (FIG. 1) about anvil retainer 260, as will be described in greater detail below.

[0086] In use, when approximation knob 26 is manually rotated, rotatable sleeve 230 is likewise rotated about the proximal end of screw 220. Since sleeve 230 is axially fixed with respect to stationary handle 22, and with tracking pin 224 disposed within helical channel 222 and rotationally fixed relative to sleeve 230, axial rotation of sleeve 230 about screw 220 causes tracking pin 224 (FIG. 17) to move along channel 222 of screw 220 to thereby urge screw 220 to translate axially within stationary handle 22 relative to sleeve 230. Upon axial translation of screw 220, first and second screw extensions 240 and 250, which are fastened to the distal end of screw 220, and anvil retainer 260, which is fastened to the distal end of screw extensions 240 and 250, are moved axially through outer tube 32 of elongated body portion 30. Thus, with anvil assembly 400 (FIG. 1) releasably engaged about the distal end of anvil retainer 260, knob 26 may be rotated to effect movement of anvil assembly 400 (FIG. 1) relative to stapling assembly 100 between spaced-apart and approximated positions, i.e., to move anvil assembly 400 closer to or further from stapling assembly 100, depending on the direction of rotation of knob 26.

[0087] With reference to FIGS. 4-8 and 16-17, approximation assembly 200 further includes a screw stop 270 disposed about screw 220 and configured to function as a proximal stop for defining the minimum tissue receiving clearance between anvil assembly 400 and stapling assembly 100. Screw stop 270 includes a cam adjustment member 272 (FIG. 7) that allows the minimum tissue gap defined between the stapling assembly 100 and the anvil assembly 400 to be selectively adjusted. Screw stop 270 includes a pair of wings 274 (FIG. 6) that extend radially outwardly from screw stop 270. Wings 274 are dimensioned to slide along channels 27 (FIG. 6) formed along the interior walls of handle sections 22a, 22b of stationary handle 22 to maintain proper alignment and guide translation of approximation assembly 200 through stationary handle 22. Upon reaching the proximal ends of channels 27 (FIG. 6) of handle sections 22a, 22b, wings 274 inhibit further proximal translation of screw 220 and, thus, further approximation of anvil assembly 400 to define the minimum tissue gap between anvil assembly 400 and stapling assembly 100.

[0088] Cam adjustment member 272 (FIG. 17) is secured by a set screw 275 within a recess 276 formed in a sidewall of screw stop 270 and includes a circular disc 277 having a bore 278 that is eccentrically formed through disc 277 and is dimensioned to receive set screw 275. Cam adjustment member 272 functions to adjust the axial position of screw stop 270 on screw 220. More specifically, due to the eccentric configuration of bore 278 of disc 277, set screw 275 can be rotated to rotate disc 277 within recess 276 of screw stop 270. Since disc 277 is eccentrically mounted about screw 220 and is engaged within portions of screw stop 270 defining recess 276, rotation of disc 277 about set screw 275 may be effected to adjust the axial position of screw stop 270 on screw 220 to a desired position corresponding to the desired minimum tissue gap between stapling assembly 100 and anvil assembly 400 (FIG. 1) when anvil assembly 400 (FIG. 1) is moved to the approximated position. Cam adjustment member 272 is described in greater detail in U.S. Patent No. 7,857,187 to Milliman, previously incorporated by reference herein in its entirety.

[0089] Referring to FIGS. 4 and 14-15, firing assembly 300 includes firing trigger 24, a firing link 310, an elongated tubular pusher link 330, and a coupling member 350. The distal end of firing trigger 24 is pivotally connected to coupling member 350 by a pivot member 352. Coupling member 350, in turn, is secured to the proximal end of elongated tubular pusher link 330 using any known fastening technique, e.g., snap-fit, threading, adhesion, etc. Alternatively, coupling member 350 may be formed integrally with pusher link 330. Coupling member 350 includes a flange 354 that is configured to maintain a spring 356 between a proximal end of outer tube 32 of elongated body portion 30 and flange 354. Spring 356 biases pusher link 330 proximally towards a retracted, non-fired position. A pair of wings 358 extends radially outwardly from coupling member 350. Wings 358 are dimensioned to slide along channels 29 (FIG. 5) formed along the interior walls of handle sections 22a, 22b of stationary handle 22 to maintain proper alignment and guide translation of coupling member 350 and pusher link 330 through stationary handle 22. Elongated tubular pusher link 330 may be formed from a flexible material to facilitate translation through curved elongated outer tube 32 of elongated body portion 30 and defines a hollow interior configured to slidably receive approximation assembly 200. Elongated tubular pusher link 330 may further include one or more guide rings (not shown) disposed about the outer periphery thereof to guide translation of elongated tubular pusher link 330 through outer tube 32. Inner assembly 180 (FIG. 28), which will be described in detail below, is disposed within outer tube 32 adjacent the distal end of elongated tubular pusher link 330.

[0090] Firing link 310 has a distal end pivotally secured to firing trigger 24 by a pivot member 312 and a proximal end that is pivotably secured to stationary handle 22. More specifically, the proximal end of firing link 310 defines a bifurcated configuration having first and second flanges 313, 315 that are configured to receive a pivot member 316 therethrough. Pivot member 316 extends between and outwardly from each of first and second flanges 313, 315 for receipt within vertical slots 28 (FIG. 22) formed within each of handle sections 22a and 22b, respectively. As such, pivot member 316 is free to move vertically within slots 28 (FIG. 22) but is substantially inhibited from horizontal translation relative to stationary handle 22, thus inhibiting the proximal end of firing link 310 from horizontal translation relative to stationary handle 22. Although not shown, it is contemplated that a spring may be supported within housing 20 to urge pivot member 316 downwardly towards the bottom of slots 28. A more detailed description of a spring configured for supporting pivot member 316 is provided in commonly owned U.S. Patent 7,303,106 to Milliman et al., the entire contents of which are incorporated by reference herein. Trigger 24 may further include a trigger lock (not shown) to prevent unintended actuation of trigger 24 or actuation of trigger 24 prior to approximation of surgical stapling apparatus 10. A more detailed description of an embodiment of a trigger lock is described in U.S. Patent 7,303,106 to Milliman et al., previously incorporated by reference herein.

[0091] Upon actuation of firing trigger 24 by pivoting firing trigger 24 about pivot members 312, 352 towards stationary handle 22 in a counter-clockwise direction (from the position shown in FIG. 4), firing link 310 is pivoted about pivot member 316 in a clockwise direction (from the position shown in FIG. 4) towards stationary handle 22 to urge firing trigger 24 and coupling member 350 distally relative to stationary handle 22. Distal translation of coupling member 350, in turn, urges pusher link 330 distally against the bias of spring 356. With the distal end of pusher link 330 coupled to pusher 1 12 of stapling assembly 100 via inner assembly 180 (FIG. 28), distal translation of pusher link 330 may be effected to translate pusher 112 distally through cartridge assembly 1 10. Thus, as will be described below, actuation of firing trigger 24 may be effected to eject surgical staples 600 (FIG. 1 1) from stapling assembly 100. Firing assembly 300 may further include a lockout mechanism, indicator mechanism, and/or feedback mechanism similar to those disclosed in U.S. Patent No. 7,857,187 to Milliman or U.S. Patent No. 6,945,444 to Gresham et al., previously incorporated by reference herein in their entirety.

[0092] Turning now to FIGS. 1 , 42, and 44, anvil assembly 400 includes an anvil head assembly 410 and an anvil center rod assembly 420. Anvil head assembly 410 includes a post 412 and an anvil head 414 that defines a plurality of pockets 419 for receiving and forming staples 600 (FIG. 1 1) about tissue. Anvil center rod assembly 420 includes an anvil center rod 422 that is pivotably engaged to post 412 of anvil head assembly 410 via a pivot member 424 to permit anvil head assembly 410 to pivot relative to anvil center rod assembly 420. Anvil center rod 422 defines a hollow interior that is configured to receive anvil retainer 260. Upon insertion of anvil retainer 260 into anvil center rod 422, annular recess 426, which extends inwardly into the hollow interior of anvil center rod 422, receives annular protrusion 268 of anvil retainer 260 such that anvil center rod 422 and, thus, anvil assembly 400 is secured about anvil retainer 260. Anvil assembly 400 may further be configured to include any or all of the features of the anvil assembly described in U.S. Patent No. 7,857,187 to Milliman or U.S. Patent No. 6,945,444 to Gresham et al., previously incorporated by reference herein in their entirety.

[0093] Turning to FIGS. 8-13 and 18-19, stapling assembly 100 includes a cartridge assembly 1 10 and an engagement assembly 140 (FIG. 8). Cartridge assembly 1 10 is configured to house a plurality of surgical staples 600 therein, arranged in annular rows, and, upon actuation of firing assembly 300, to facilitate the ejection of surgical staples 600 therefrom, through tissue, and into anvil head 414 (FIGS. 42 and 44) for formation of the surgical staples 600 about tissue. Engagement assembly 140 is configured to facilitate operable engagement of stapling assembly 100 to engagement shell 36 at the distal end of outer tube 32 of elongated central body portion 30. Stapling assembly 100 (or component(s) thereof) is preferably formed as a disposable assembly that is configured to be replaced with a new stapling assembly after each firing.

[0094] Engagement assembly 140 includes a distal shell 142 that may be formed from any suitable material, e.g., polyethylene, and is configured as a disposable component. Distal shell 142 (FIG. 1 1) includes an outer housing portion 144 and an inner guide portion 146. Outer housing portion 144 has a distal cylindrical section 147, a central conical section 148, and a proximal cylindrical section 149 that defines a smaller diameter than distal cylindrical section 147. A plurality of openings 150 are formed in conical section 148 to permit fluid and tissue passage during operation of surgical stapling apparatus 10. A pair of diametrically opposed engagement tabs 151 , each including an engagement nub 152, is formed on the exterior surface of proximal cylindrical section 149. Engagement tabs 151 , as will be described below, are positioned to be received in engagement slots 165 defined within engagement shell 36 of central elongated body portion 30 to facilitate re leasable securement of stapling assembly 100 at the distal end of outer tube 32 of elongated body portion 30. Distal shell 142 further includes a plurality of spaced-apart orientation bars 154 (FIG. 12) disposed about the interior surface of proximal cylindrical section 149. Orientation bars 154 (FIG. 12) are configured for receipt within slots 33 defined about the distal end of outer tube 32 to rotationally fix distal shell 142 about the distal end of outer tube 32 of elongated body portion 30 during assembly.

[0095] Referring also to FIGS. 27-35, engagement shell 36 (FIG. 8) of central elongated body portion 30 includes a distal cylindrical section 161 (FIG. 27), a central conical section 162 (FIG. 27), and a proximal cylindrical section 163 (FIG. 27) that defines a smaller diameter than distal cylindrical section 161. Engagement shell 36, outer tube 32, and/or proximal bushing 34 of central elongated body portion 30 may be formed from a sterilizable material, e.g., stainless steel or other suitable metal or sterilizable material, such that these components may be sterilized and reused without the material substantially degrading. A plurality of openings 164 (FIG. 27) are formed in conical section 162 to permit fluid and tissue passage during operation of surgical stapling apparatus 10. Proximal cylindrical section 163 of engagement shell 36 is rotatably disposed about the distal end of outer tube 32 of elongated body portion 30 in any suitable fashion, e.g., via engagement between first and second annular protrusions 39a, 39b defined towards the distal end of outer tube 32. With engagement shell 36 disposed about outer tube 32 between annular protrusions 39a, 39b, a relatively small amount of longitudinal translation of engagement shell 36 relative to outer tube 32 is permitted, e.g., engagement shell 36 is permitted to move between first annular protrusion 39a and second annular protrusion 39b (FIG. 34). [0096] Distal cylindrical section 161 of engagement shell 36 is configured to receive proximal cylindrical section 149 of distal shell 142. More specifically, distal cylindrical section 161 of engagement shell 36 includes at least one protrusion such as a pair of opposed engagement slots 165 configured to receive engagement tabs 151 of distal shell 142. Engagement slots 165 each define an open end configured to permit passage of engagement tabs 151 therethrough upon insertion of proximal cylindrical section 149 of distal shell 142 into distal cylindrical section 161 of engagement shell 36, and a transverse portion configured to permit translation of one of the engagement tabs 151 therethrough upon relative rotation between distal shell 142 and engagement shell 36. Slots 165 each further include an engagement notch 166 configured for receipt of a respective engagement nub 152 therein to facilitate releasable securement of stapling assembly 100 at the distal end of outer tube 32 of elongated body portion 30, as will be described below. Other configurations are also contemplated. For example, shell 142 may include any number of protrusions or engagement tabs 151. Engagement tabs 151 may take on any number of shapes, including but not limited to straight or L-shaped. Engagement slot 165 may also take on any shape, such as curved or L-shaped. It is also envisioned that distal cylindrical section 161 of engagement shell 36 may include engagement tabs while distal shell 142 includes engagement slots. Further, a biasing member 170 is positioned about outer tube 32 between outer tube 32 and engagement shell 36 and, more particularly, between first annular protrusion 39a and proximal cylindrical section 163. Biasing member 170 is configured to bias engagement shell 36 proximally.

[0097] Referring to FIGS. 8, 18, and 19, inner assembly 180, as mentioned above, is disposed within outer tube 30 adjacent the distal end of elongated tubular pusher link 330 of firing assembly 300 (FIG. 8). Inner assembly 180 includes a base member 182, first and second rings 183, 185, respectively, and a biasing member 186. Base member 182 includes a collar 187 and a shaft 189 extending proximally from collar 187. Collar 187 includes a pair of resilient finger tabs 190 that, as will be described below, are configured to releasably-engage pusher 1 12 of cartridge assembly 1 10, e.g., via snap-fit or other suitable engagement. First and second rings 183, 185, respectively, are configured for positioning about shaft 189 with biasing member 186 disposed about shaft 189 between rings 183, 185. More specifically, first ring 183 is fixedly engaged to shaft 189 and is configured to abut the distal end of elongated tubular pusher link 330 of firing assembly 300 (FIG. 8), while second ring 185 is fixedly engaged to the interior surface of outer tube 32 and is biased into abutment with collar 187 via biasing member 186. Biasing member 186 biases first and second rings 183, 185 apart from one another, thus biasing collar 187 and elongated tubular pusher link 330 apart from one another.

[0098] With reference to FIGS. 8-13 and 18-19, cartridge assembly 1 10 is housed within distal shell 142 of engagement assembly 140 and includes a pusher 112 (FIG. 1 1), a cylindrical knife 114, and a staple guide cap 1 16. As mentioned above, cartridge assembly 110 and distal shell 142 are configured as disposable components. Thus, a new cartridge assembly 110 is provided when distal shell 142 is replaced after each use. Pusher 1 12 of cartridge assembly 1 10 includes a central bore 118 and is configured to be received within distal shell 142. More specifically, pusher 1 12 includes a distal cylindrical section 1 19, which is slidably positioned within distal cylindrical section 147 of distal shell 142, a central conical section 121 , which is slidably positioned within central conical section 148 of distal shell 142, and a proximal cylindrical section 123 having a smaller diameter than distal cylindrical section 119, which is slidably positioned within proximal cylindrical section 149 of distal shell 142. The proximal end of pusher 1 12 includes a pair of proximally-extending arm members 125. Arm members 125 each include a slot 127 that is configured to receive and lockingly engage one of the resilient finger tabs 190 of collar 187 of base member 182 to secure base member 182 of inner assembly 180 to pusher 1 12 of cartridge assembly 110. Thus, as will be described below, with elongated tubular pusher link 330 engaged to inner assembly 180 and with inner assembly 180 engaged to pusher 112, actuation of firing trigger 24 urges pusher 112 distally to eject staples from cartridge assembly 110 of stapling assembly 100. Biasing member 186 biases base member 182 to return proximally upon return of pusher link 330 to its initial position.

[0099] The distal end of pusher 1 12 includes a plurality of distally-extending pusher fingers 129 dimensioned to be slidably received within slots 131 formed in staple guide cap 1 16. Staple guide cap 116 is engaged about the distal end of distal shell 142 via the engagement of tabs 133 and recesses 135, e.g., via snap-fit, welding, adhesion, etc. Each slot 131 formed within staple guide cap 116 is configured to retain a surgical staple 600 such that, upon advancement of pusher 112 via actuation of firing trigger 24, surgical staples 600 are ejected from slots 131 of staple guide cap 116, through tissue, and into anvil head 414 (FIGS. 42 and 44) of anvil assembly 400 (FIGS. 42 and 44) for formation about tissue. Cylindrical knife 114 is pinned within bore 1 18 of pusher 1 12 to fixedly secure knife 1 14 in relation to pusher fingers 129 such that advancement of pusher 1 12 to eject surgical staples 600 from staple guide 116 is effected simultaneously with advancement of knife 114 through tissue. The distal end of knife 1 14 includes a circular cutting edge 115 to facilitate the cutting of tissue.

[00100] With reference to FIGS. 4 and 20-26, as mentioned above, stationary handle 22 is formed from first and second releasably engagable handle sections 22a and 22b (FIG. 22) that cooperate to house the internal components of handle portion 20. Handle sections 22a, 22b are configured as reusable, sterilizable components, although handle sections 22a, 22b may alternatively be configured as disposable components. In either configuration, handle sections 22a, 22b facilitate engagement and disengagement from one another, as described below. More specifically, first and second lower engagements 510, 512 (FIG. 20) disposed at the proximal and distal ends, respectively, of handle sections 22a, 22b, and first and second upper engagements 540, 542 disposed at the proximal and distal ends, respectively, of handle sections 22a, 22b, cooperate to facilitate the re leasable coupling of handle sections 22a, 22b to one another. That is, engagements 510, 512, 540, 542 facilitate both the assembly of handle portion 20 in preparation for use and the disassembly of handle portion 20 for sterilization of handle portion 20 and the components disposed therein and/or replacement of handle portion 20 or the components disposed therein in preparation for subsequent use.

[00101] With respect to first and second lower engagements 510, 512 disposed at the proximal and distal ends of handle sections 22a, 22b, respectively, each lower engagement 510, 512 is substantially similar to the other and, thus, only first lower engagement 510 will be described herein to avoid unnecessary repetition. First lower engagement 510 includes a hook assembly 513 (FIG. 23) disposed on one of the handle sections, e.g., handle section 22a, and a receiving member 520 (FIG. 24) disposed on the other handle section, e.g., handle section 22b. Hook assembly 513 includes a hook base member 514 disposed within a recess 516 defined within handle section 22a and is pivotably coupled to handle section 22a via a pivot member 517. Hook base member 514 includes a first end 514a disposed on one side of pivot member 517 and a second end 514b disposed on the other side of pivot member 517 and defining a hook 518. A biasing member 519 (FIG. 25) is disposed within recess 516 and is positioned adjacent first end 514a of hook base member 514 to bias first end 514a of hook base member 514 upwardly out of recess 516, thereby biasing second end 514b of hook base member 514 downwardly into recess 516. Receiving member 520 of handle section 22b defines a recess 522 having a shallow portion 524 and a relatively-deeper hook-receiving portion 526. To engage handle sections 22a, 22b to one another, as will be described below, second end 514b of hook base member 514 of hook assembly 513 is inserted into recess 522 of receiving member 520 until hook 518 is biased into engagement within hook-receiving portion 526 of recess 522.

[00102] With respect to first and second upper engagements 540, 542 disposed at the proximal and distal ends of handle sections 22a, 22b, each upper engagement 540, 542 is substantially similar to the other and, thus, only first upper engagement 540 will be described herein to avoid unnecessary repetition. First upper engagement 540 includes a plunger assembly 543 (FIG. 21) disposed on one of the handle sections, e.g., handle section 22a, and a protrusion member 550 disposed on the other handle section, e.g., handle section 22b. Plunger assembly 543 includes a central recess 544 and two opposed spring-biased plungers 545 extending into central recess 544. Plungers 545 each include a body 546 and a tip member 547 and are biased inwardly into recess 544 and towards one another, e.g., via torsion springs (not shown) disposed about plunger bodies 546 or other suitable biasing member. As such, with plungers 545 extending into central recess 544, tip members 547 are biased towards one another and into central recess 544. Protrusion member 550 of handle section 22b extends towards handle section 22a and includes a receiving hole 552 disposed on either side thereof. During approximation of handle sections 22a, 22b to engage handle sections 22a, 22b to one another, protrusion member 550 is inserted into central recess 544. As protrusion member 550 is inserted into central recess 544, tip members 547 of plungers 545 are initially urged outwardly against their bias until protrusion member 550 is inserted sufficiently into central recess 544 so that tip members 547 align with receiving holes 552. Once aligned with receiving holes 552, tip members 547 are permitted to return towards one another and further into central recess 544 under bias such that tip members 547 of plungers 545 are biased into receiving holes 552 to engage protrusion member 550 within central recess 544.

[00103] The use of surgical stapling apparatus 10, disassembly of surgical stapling apparatus 10 for sterilization of the reusable components after use, replacement of the disposable components, and reassembly of surgical stapling apparatus 10 for subsequent use is now described in detail.

[00104] With reference to FIGS. 36-44, in use, distal head portion 40 (FIG. 37) of surgical stapling apparatus 10 inserted into an internal surgical site such that anvil assembly 400 and stapling assembly 100 are positioned adjacent tissue to be stapled. Once positioned as desired, anvil assembly 400 is approximated relative to stapling assembly 100 to clamp tissue therebetween via manipulating approximation assembly 200 (FIG. 42). More specifically, referring to FIGS. 39-42, anvil assembly 400 (FIG. 42) is moved proximally to the approximated or closed position to grasp tissue between anvil assembly 400 and stapling assembly 100 by rotating rotation knob 26 in a first direction. Rotation of knob 26 in the first direction causes cylindrical sleeve 230 to rotate to move pin 224 (FIG. 40) along helical channel 222 of screw 220 such that screw 220 is translated proximally. The distal end of screw 220 is connected to screw extensions 240 and 250 which, in turn, are fastened at their distal ends to anvil retainer 260, such that anvil retainer 260 is likewise translated proximally to approximate anvil assembly 400 relative to stapling assembly 100. Knob 26 may be rotated to approximate anvil assembly 400 relative to stapling assembly 100 to clamp tissue therebetween until the minimum tissue gap between anvil assembly 400 and stapling assembly 100, which is set via screw stop 270, is achieved. [00105] With anvil assembly 400 disposed in the approximated position clamping tissue between anvil head 414 and staple guide cap 1 16 of stapling assembly 100, firing assembly 300 may be actuated to staple and core the clamped tissue. More specifically, in order to fire surgical stapling apparatus 10, trigger 24 is compressed towards stationary handle 22. As described above, the distal end of firing trigger 24 is connected through coupling member 350 to the proximal end of pusher link 330. Accordingly, as firing trigger 24 is actuated, pusher link 330 is moved distally to urge inner assembly 180 and, thus, pusher 1 12 of cartridge assembly 110 distally. Upon distal translation of pusher 112 relative to staple guide cap 116, which retains the surgical staples 600 therein, fingers 129 of pusher 1 12 engage and eject staples 600 from staple guide cap 116, through tissue, and into anvil head 414 of anvil assembly 400, which form staples 600 about tissue. Cylindrical knife 1 14 is moved concurrently with pusher 112 such that knife 114 is likewise advanced distally to core tissue.

[00106] In one exemplary method of use, surgical stapling apparatus 10 is used to perform a circular anastomosis. 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 and the end portions of the remaining first and second vessel sections are joined together using the surgical stapling apparatus 10.

[00107] During such a procedure using the surgical stapling apparatus 10, prior to removing the diseased vessel portion from the diseased vessel, the anvil assembly 400 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 400 is disclosed in U.S. Patent No. 6,945,444 to Gresham et al., which, as discussed above, is incorporated herein by reference in its entirety. After the diseased vessel portion is removed and the open ends of the first and second vessel sections have been sutured, the distal end of apparatus 10 is positioned in the second vessel section on the other side of the diseased vessel portion which has been removed. At this time, the removable trocar (not shown) is pushed through the suture line in the end of the first vessel section and removed from the anvil assembly. Next, trocar tip 267 of anvil retainer 260 is pushed through the suture line in the second vessel section and is joined to the center rod of the anvil assembly 400. The surgical stapling apparatus 10 can 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.

[00108] At the completion of the stapling operation, surgical stapling apparatus 10 may be removed from the internal surgical site. More specifically, anvil assembly 400 may be configured to pivot to a low-profile configuration after firing and upon un-approximation of anvil assembly 400 relative to stapling assembly 100 to facilitate removal of surgical stapling apparatus 10 from the internal surgical site. A suitable tilting mechanism is described in U.S. Patent No. 7,857,187 to Milliman, previously incorporated by reference herein in its entirety. Alternatively, anvil assembly 400 need not have a pivotal head and may be removed from the surgical site in the same orientation as it was advanced into the surgical site.

[00109] Upon removal from the internal surgical site at the completion of the surgical procedure, surgical stapling apparatus 10 may be disassembled to facilitate sterilizing the reusable components and replacing the disposable components. More specifically, and with reference to FIGS. 22-44, to disassemble surgical stapling apparatus 10, anvil assembly 400 is first removed from anvil retainer 260. In order to disengage anvil assembly 400 from anvil retainer 260, anvil assembly 400 is spaced-apart from stapling assembly 100, e.g., via rotating knob 26 in a second, opposite direction, sufficiently such that annular protrusion 268 of anvil retainer 260 and annular recess 426 of anvil center rod 422 are no longer positioned within stapling assembly 100. Once this position has been achieved, anvil assembly 400 may be urged apart from anvil retainer 260 with sufficient force so as to flex center rod 422 radially outwardly to disengage annular protrusion 268 from annular recess 426, thus allowing anvil assembly 400 to be removed from anvil retainer 260. Anvil assembly 400 is configured as a sterilizable, reusable component although it is also contemplated that anvil assembly be configured as a disposable component and discarded after use to be replaced by a new anvil assembly.

[00110] Once anvil assembly 400 has been removed, stapling assembly 100 may be disengaged from surgical stapling apparatus 10. More specifically, stapling assembly 100 is disengaged from the distal end of outer tube 32 by first urging engagement shell 36 distally against the bias of biasing member 170 and relative to distal shell 142 such that engagement nubs 152 of distal shell 142 are disengaged from engagement notches 166 of engagement shell 36. Thereafter, engagement shell 36 is rotated relative to distal shell 142 such that engagement tabs 151 are translated along the transverse portions of engagement slots 165 to the open ends thereof. Once sufficiently rotated such that engagement tabs 151 are aligned with the open ends of engagement slots 165, engagement shell 36 may be released, allowing engagement shell 36 to return proximally under the bias of biasing member 170 and such that engagement tabs 151 are released from engagement slots 165, thereby disengaging distal shell 142 from engagement shell 36.

[00111] With distal shell 142 no longer engaged to engagement shell 36, stapling assembly 100 may be translated proximally relative to surgical stapling apparatus 10 with sufficient urging so as to disengage proximally-extending arm members 125 of pusher 112 from resilient finger tabs 190 of collar 187 of inner assembly 180 to fully disengage stapling assembly 100 from the remainder of surgical stapling apparatus 10. Arms 125 may additionally or alternatively be squeezed inwardly towards one another to facilitate disengagement from finger tabs 190. Once disengaged, stapling assembly 100 may then be removed from positioning about anvil retainer 260 and may be disposed of, although it is also contemplated that one or more components of stapling assembly 100 be sterilizable for reuse.

[00112] In order to disassembly handle portion 22 in preparation for sterilization, bushing 34 is disengaged from handle portion 22, e.g., by translating bushing 34 distally relative to handle portion 22 over outer tube 32. Next, handle sections 22a, 22b are moved in sheering relation relative to one another, e.g., handle portion 22a is moved upwardly and/or handle portion 222b is moved downwardly relative to the other, to disengage hook assemblies 513 from receiving members 520 and, simultaneously or near-simultaneously, to disengage protrusion members 550 from plunger assemblies 543, thereby separating handle portions 22a, 22b from one another (see FIG. 22). It is also contemplated that handle sections 22a, 22b be manipulated in any other suitable fashion so as to facilitate the disengagement of handle sections 22a, 22b from one another.

[00113] Once handle sections 22a, 22b have been disengaged from one another and removed from surgical stapling apparatus 10, approximation assembly 200 may be removed from firing assembly 300 by sliding approximation assembly 200 out of pusher link 330 and coupling member 350. Thus, with handle sections 22a, 22b, approximation assembly 200, and firing assembly 300 disengaged from one another, sterilization of each of these components for reuse may be readily achieved. Alternatively, one or more of these components may be configured as a disposable component and, thus, may be replaced with a new component rather than being sterilized.

[00114] Once the reusable components, e.g., handle sections 22a, 22b, approximation assembly 200, and firing assembly 300, have been sterilized and the replaceable components, e.g., stapling assembly 100, replaced with a fresh stapling assembly 100, surgical stapling apparatus 10 may be reassembled for subsequent use. Initially, with reference to FIGS. 4-8 and 14-17 the distal end of approximation assembly 200 is inserted through coupling member 350 and pusher link 330 of firing assembly 300. Next, both the approximation assembly 200 and firing assembly 300 are positioned within one of the handle sections 22a, 22b, e.g., handle section 22b, such that collar 232 of rotatable sleeve 230 receives flange 22c of handle section 22b, a wing 274 of screw stop 270 is slidably received within channel 27 of handle section 22b, a wing 358 of coupling member 350 is slidably received within channel 29 of handle section 22b, and pivot member 316 is received within vertical slot 28 of handle section 22b. Once approximation assembly 200 and firing assembly 300 are engaged within one of handle sections 22a, 22b, handle sections 22a, 22b may be engaged to one another to house the proximal components of firing assembly 300 and approximation assembly 200 therein.

[00115] With reference to FIGS. 22-26, in order to engage handle sections 22a, 22b to one another, handle sections 22 a, 22b are approximated relative to one another such that hook assemblies 513 and receiving members 520 of lower engagements 510, 512 are aligned with one another and plunger assemblies 543 and protrusion members 550 of upper engagements 540, 542 are aligned with one another. Once aligned, handle sections 22a, 22b may be further approximated relative to one another such that hooks 518 of hook base member 514 are secured within hook-receiving portions 526 of recesses 522 and such that protrusions members 550 are secured within recesses 544 via plungers 545, thereby engaging handle sections 22a, 22b to one another at the proximal and distal ends thereof and on the top and bottom sides thereof. Upon engagement of handle sections 22a, 22b to one another, collar 232 of rotatable sleeve 230 receives flange 22c of handle section 22a, the other wing 274 of screw stop 270 is slidably received within channel 27 of handle section 22a, the other wing 358 of coupling member 350 is slidably received within channel 29 of handle section 22a, and pivot member 316 is received within vertical slot 28 of handle section 22a.

[00116] Referring again to FIGS. 4-8 and 14-17, next, elongated central body portion 30 may be maneuvered into position such that outer tube 32 is disposed about pusher link 330 of firing assembly 300, which is disposed about screw extensions 240, 250 of approximation assembly 200, with anvil retainer 260 extending distally from both pusher link 330 and outer tube 32. The proximal end of outer tube 32 may be secured relative to stationary handle 22 via bushing 24 by snap-fitting bushing 24 about both outer tube 32 and the distal end of stationary handle 18. Alternatively, other suitable engagement configurations are also contemplated.

[00117] With reference to FIGS. 27-35, in order to assemble stapling assembly 100 and anvil assembly 400 at the distal end of outer tube 32, cartridge assembly 1 10, which is engaged within distal shell 142, is approximated relative to the engagement shell 36 disposed at the distal end of outer tube 32. More specifically, distal shell 142, including cartridge assembly 1 10, is positioned about anvil retainer 260 and is approximated relative to the distal end of outer tube 32 such that orientation bars 154 of distal shell 142 are received within slots 33 defined at the distal end of outer tube 32 to ensure proper alignment therebetween. Upon further advancement of cartridge assembly 1 10 and distal shell 142 towards the distal end of outer tube 32, resilient finger tabs 190 of collar 187 of inner assembly 180 are flexed inwardly upon contact with proximally-extending arm members 125 of pusher 112 of cartridge assembly 110 and, ultimately, are biased into engagement within slots 127 defined within arm members 125 of cartridge assembly 110 to engage inner assembly 180 and cartridge assembly 110 to one another.

[00118] With inner assembly 180 and cartridge assembly 110 engaged to one another, engagement shell 36 is moved distally against the bias of biasing member 170 such that engagement tabs 151 of distal shell 142 are inserted through the open ends of engagement slots 165 of engagement shell 36. Once engagement tabs 151 of distal shell 142 are inserted into engagement slots 165 of engagement shell 36, engagement shell 36 is rotated relative to distal shell 142 such that engagement tabs 151 are translated along the transverse portions of engagement slots 165 and away from the open ends thereof. Once sufficiently rotated to the position shown in FIG. 33, engagement shell 36 may be released, allowing biasing member 170 to bias engagement shell 36 proximally and away from distal shell 142 such that engagement nubs 152 are received within engagement notches 166 to secure distal shell 142 and engagement shell 36 to one another about the distal end of outer tube 32.

[00119] Once stapling assembly 100 is engaged about the distal end of outer tube 32, as shown in FIGS. 36 and 37 and as described above, anvil assembly 400 may be engaged to anvil retainer 260, which extends distally through and from stapling assembly 100. In order to engage anvil assembly 400 about anvil retainer 260, anvil center rod 422 is disposed about anvil retainer 260 until annular recess 426 receives annular protrusion 268 of anvil retainer 260 to secure anvil assembly 400 about anvil retainer 260. Upon retraction of anvil retainer 260 during movement of anvil assembly 400 to the approximated position to clamp tissue between stapling assembly 100 and anvil assembly 400, annular protrusion 268 is positioned within stapling assembly 100, thus inhibiting removal of anvil assembly 400 therefrom due to the inability of annular recess 426 of anvil center rod 422 to flex outwardly to disengage from annular protrusion 268. Rather, removal of anvil assembly 422 is only permitted when anvil retainer 260 is disposed in an extended position, e.g., the position shown in FIG. 37.

[00120] As can be appreciated, the above-described cycle of use, disassembly, sterilization and replacement, and reassembly, may be repeated for a plurality of usage cycles.

[00121] It will be understood that various modifications may be made to the embodiments of the surgical stapling apparatus disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. A surgical stapling apparatus, comprising:

a handle portion;

an elongated body portion extending distally from the handle portion, the elongated body portion including an engagement member rotatably coupled to the elongated body portion towards a distal end thereof and defining an engagement slot;

a firing assembly including a firing trigger and a firing link extending at least partially through the elongated body portion, the firing link configured for distal translation through the elongated body portion in response to actuation of the firing trigger; and

a replaceable stapling assembly configured to house a plurality of surgical staples therein, the replaceable stapling assembly including an outer shell having an engagement tab, wherein the engagement member is rotatable relative to the elongated body portion and the replaceable stapling assembly to releasably engage the engagement tab within the engagement slot, thereby securing the replaceable stapling assembly at the distal end of the elongated body portion and operably coupling the replaceable stapling assembly to the firing link such that, in response to distal advancement of the firing link, the plurality of surgical staples are ejected from the replaceable stapling assembly.

2. The surgical stapling apparatus according to claim 1, wherein the firing trigger extends from the handle portion and is coupled to the firing link, the firing trigger selectively actuatable to translate the firing link distally through the elongated body portion.

3. The surgical stapling apparatus according to claim 1 , further comprising an approximation assembly, the approximation assembly including a drive member configured to extend distally from the elongated body potion and the replaceable stapling assembly, the distal end of the drive member configured to releasably engage an anvil assembly.

4. The surgical stapling apparatus according to claim 3, further comprising an approximation knob extending from the handle portion, the approximation knob coupled to the drive member and selectively actuatable to move the anvil assembly between a spaced-apart position and an approximated position relative to the replaceable stapling assembly.

5. The surgical stapling apparatus according to claim 4, wherein the drive member defines a helical channel and wherein the approximation knob is coupled to a pin disposed within the helical channel such that rotation of the approximation knob effects translation of the drive member.

6. The surgical stapling apparatus according to claim 1 , wherein a biasing member is disposed between the elongated body portion and the engagement member to bias the engagement member proximally.

7. The surgical stapling apparatus according to claim 6, wherein the engagement tab is retained in engagement within the engagement slot under the bias of the biasing member.

8. The surgical stapling apparatus according to claim 1, wherein the engagement tab further includes an engagement nub and wherein the engagement slot further includes an engagement notch, the engagement nub configured to engage the engagement notch to secure the replaceable stapling assembly at the distal end of the elongated body portion and operably couple the replaceable stapling assembly to the firing link.

9. The surgical stapling apparatus according to claim 1 , wherein the replaceable stapling assembly includes a cartridge assembly disposed within the outer shell.

10. The surgical stapling apparatus according to claim 9, wherein the cartridge assembly includes a pusher including a plurality of pusher fingers configured to support the plurality of surgical staples and a staple guide member configured to guide ejection of the surgical staples from the replaceable stapling assembly.

11. The surgical stapling apparatus according to claim 1, wherein the handle portion is formed from first and second handle sections, the first and second handle sections releasably engagable with one another.

12. The surgical stapling apparatus according to claim 11, wherein the first and second handle sections are releasably engaged with one another via at least one of a hook assembly and a plunger assembly.

13. A surgical stapling apparatus, comprising:

a handle portion;

a curved elongated body portion extending distally from the handle portion;

a stapling assembly disposed at a distal end of the curved elongated body portion, the stapling assembly configured to house a plurality of surgical staples therein; and

an approximation assembly including a drive member configured to engage an anvil assembly at a distal end of the drive member, the drive member configured for selective translation through and relative to the curved elongated body portion and the stapling assembly to move the anvil assembly relative to the stapling assembly, the drive member including a pair of opposed flexible portions configured to facilitate translation of the drive member through the curved elongated body portion, the opposed flexible portions engaged to one another along at least a portion of lengths thereof via a plurality of pins arranged so that heads of the pins are alternatingly disposed on either side of the flexible portions along the lengths thereof.

14. The surgical stapling apparatus according to claim 13, further comprising an approximation knob extending from the handle portion, the approximation knob coupled to the drive member and selectively actuatable to move the anvil assembly between a spaced-apart position and an approximated position relative to the stapling assembly.

15. The surgical stapling apparatus according to claim 14, wherein the drive member defines a helical channel and wherein the approximation knob is coupled to a pin disposed within the helical channel such that rotation of the approximation knob effects translation of the drive member.

16. The surgical stapling apparatus according to claim 13, wherein first and second flat bands form the opposed flexible portions of the drive member.

17. The surgical stapling apparatus according to claim 13, wherein the drive member further includes a proximal shaft portion, and wherein the opposed flexible portions are engaged to and extend distally from a distal end of the proximal shaft portion.

18. The surgical stapling apparatus according to claim 17, wherein the drive member further includes a distal anvil retainer configured to engage the anvil assembly, the opposed flexible portions engaged to the anvil retainer at distal ends of the opposed flexible portions.

19. The surgical stapling apparatus according to claim 13, further comprising a firing assembly including a firing trigger and a firing link disposed about the drive member and extending at least partially through the curved elongated body portion, the firing link configured for distal advancement through the elongated body portion in response to actuation of the firing trigger to eject the plurality of surgical staples from the stapling assembly.

20. A surgical stapling apparatus, comprising:

a handle portion formed from first and second handle sections;

an elongated body portion extending distally from the handle portion; a stapling assembly disposed at a distal end of the elongated body portion, the stapling assembly configured to house a plurality of surgical staples therein, an approximation assembly including an approximation actuator extending from the handle portion and a drive member coupled to the approximation actuator, the drive member configured to engage an anvil assembly at a distal end thereof, the drive member configured for translation through the elongated body portion in response to actuation of the approximation actuator to move the anvil assembly relative to the stapling assembly; and

a firing assembly including a firing trigger extending from the handle portion and a firing link coupled to the firing trigger, the firing link configured for distal translation through the elongated body portion in response to actuation of the firing trigger to eject the plurality of surgical staples from the stapling assembly,

wherein the first and second handle sections are releasably engagable with one another to house at least a portion of the approximation assembly and at least a portion of the firing assembly therein via at least one hook and recess engagement and at least one plunger and protrusion engagement.

21. The surgical stapling apparatus according to claim 20, wherein the hook and recess engagement includes a hook assembly coupled to one of the first and second handle sections and a recess defined within the other of the first and second handle sections, the hook assembly including a hook and a biasing member configured to bias the hook into engagement with the recess upon approximation of the first and second handle sections.

22. The surgical stapling apparatus according to claim 20, wherein the plunger and protrusion engagement includes a pair of opposed, inwardly-biased plungers disposed on one of the first and second handle sections, and a protrusion disposed on the other of the first and second handle sections, the plungers configured to bias inwardly into engagement with the protrusion upon approximation of the first and second handle sections.

23. The surgical stapling apparatus according to claim 20, wherein the first and second handle sections each include first channels configured to receive a portion of the drive member to guide translation of the drive member.

24. The surgical stapling apparatus according to claim 20, wherein the first and second handle sections each include second channels configured to receive a portion of the firing link to guide translation of the firing link.

25. A method of surgery, comprising the steps of:

providing a surgical stapling apparatus, including:

a handle portion formed from first and second handle sections releasably engaged to one another;

an elongated body portion extending distally from the handle portion and having an engagement member coupled thereto towards a distal end thereof;

a firing assembly disposed at least partially within the handle portion and the elongated body portion;

an approximation assembly disposed at least partially within the handle portion and the elongated body portion and extending distally therefrom;

an anvil assembly disposed at a distal end of the approximation assembly; and a first replaceable stapling assembly housing a first plurality of surgical staples therein, the first replaceable stapling assembly engaged to the engagement member of the elongated body portion;

inserting the surgical stapling apparatus into an internal surgical site; actuating the approximation assembly to clamp tissue between the first replaceable stapling assembly and the anvil assembly;

actuating the firing assembly to eject the first plurality of surgical staples from the first replaceable stapling assembly, through the clamped tissue, and into the anvil assembly to form the first plurality of surgical staples about the clamped tissue;

removing the surgical stapling apparatus from the internal surgical site;

disengaging the first replaceable stapling assembly from the engagement member; and

disengaging the first and second handle sections from one another.

26. The method according to claim 25, further comprising the steps of:

disassembling the first and second handle sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly from one another;

sterilizing the first and second housing sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly;

reassembling the first and second handle sections, the elongated body portion, the anvil assembly, the firing assembly, and the approximation assembly to one another; and

engaging a second replaceable stapling assembly with the engagement member, the second replaceable stapling assembly housing a second plurality of surgical staples therein.

27. The method according to claim 26, further comprising the steps of:

inserting the surgical stapling apparatus into an internal surgical site; actuating the approximation assembly to clamp tissue between the second replaceable stapling assembly and the anvil assembly;

actuating the firing assembly to eject the second plurality of surgical staples from the second replaceable stapling assembly, through the clamped tissue, and into the anvil assembly to form the second plurality of surgical staples about the clamped tissue.