Surgical stapling device with tissue gap control - Patent Application 20070122997

Abstract

The surgical stapling device includes a cartridge assembly for accommodating tissue of different thicknesses. The cartridge assembly includes a channel member and a staple cartridge received within the channel member for movement between positions to vary the size of a tissue gap defined between the staple cartridge and an anvil of the stapling device. The cartridge assembly also includes features formed on a pusher or cartridge body of the staple cartridge of the cartridge assembly to improve staple formation when stapling thin tissue.

Description

[Technical Field]

[0001] The present disclosure relates to a surgical stapling device and, more particularly, to a surgical stapling device that includes a tool assembly having a cartridge assembly for accommodating different tissue thicknesses. [Background technology]

[0002] Surgical stapling devices for discharging staples to quickly and efficiently join tissue or tissue segments in various surgical procedures, such as anastomosis procedures, are well known. Typically, surgical stapling devices include a tool assembly having first and second jaws supporting a cartridge assembly and an anvil, respectively. The cartridge assembly includes a staple cartridge supporting a plurality of staples. The first and second jaws are attached together to enable movement of the tool assembly between an open position and a clamping position. In the clamping position, the staple cartridge and anvil of the cartridge assembly are supported in side-by-side alignment and include tissue contacting surfaces that define a predetermined tissue gap. The tissue gap and staple size within the staple cartridge are dimensioned to receive and suture tissue having a predetermined range of thickness to adequately achieve hemostasis. If the tissue positioned between the jaws is outside the predetermined range, i.e., too thick or too thin, the staples may become malformed and may not provide effective hemostasis. Additionally, if the clinician misidentifies the tissue thickness or if the tissue thickness is near the outer edge of the range for a given staple size, the chances of ineffective hemostasis increase.

[0003] There is a continuing need in the suturing art for surgical stapling devices that can provide effective hemostasis over a wider range of tissue thicknesses. Summary of the Invention [Means for solving the problem]

[0004] The present disclosure relates to various aspects of a cartridge assembly of a stapling device for accommodating tissue of different thicknesses. In some aspects of the present disclosure, the cartridge assembly includes a channel member and a staple cartridge received within the channel member for movement relative to the channel member between positions to alter a tissue gap defined between the staple cartridge and an anvil of the stapling device. Other aspects of the present disclosure relate to features formed on a pusher or cartridge body of the staple cartridge of the cartridge assembly to improve staple formation when stapling thin tissue.

[0005] One aspect of the present disclosure relates to a cartridge assembly including a channel member, a staple cartridge, and a spring. The channel member has a proximal portion and a distal portion and includes side walls and a bottom wall defining a cavity. The bottom wall defines a knife slot. The staple cartridge is received within the cavity of the channel member and includes a cartridge body, staples, a pusher, and a staple guard. The cartridge body defines a knife slot and staple-receiving pockets arranged in a row on each side of the knife slot. The staples and the pusher are received within the staple-receiving pockets, and the pusher is movable from a lowered position within the staple-receiving pockets to a raised position to eject the staples from the staple-receiving pockets. The staple guard is supported on the cartridge body and positioned to retain the staples and the pusher within the cartridge body. The spring is secured to the bottom wall of the channel member in a preloaded state.

[0006] In aspects of the present disclosure, the channel member includes a distal portion and a proximal portion, the distal portion of the channel member defining an opening extending through a bottom wall of the channel member.

[0007] In some aspects of the present disclosure, the spring includes a wave spring having a distal portion including a hook received in an opening in the channel member to secure the distal portion of the wave spring to the channel member.

[0008] In certain aspects of the present disclosure, the wave spring includes a base portion and two elongated spring legs extending distally from the base portion on opposite sides of the knife slot, the base portion supporting the hook.

[0009] In an embodiment of the present disclosure, each of the two elongated spring legs includes a proximal portion that is secured to the bottom wall of the channel member to secure the wave spring to the channel member in a preloaded state.

[0010] In some embodiments of the present disclosure, a proximal portion of each of the two elongated spring legs is welded to the bottom wall of the channel member.

[0011] In certain aspects of the present disclosure, the channel member includes a finger that extends into the opening, and the hook is received around the finger.

[0012] In aspects of the present disclosure, the base portion is formed separately from the two elongated spring legs, and the two elongated spring legs are secured to the base portion.

[0013] In some aspects of the present disclosure, the opening is sized to facilitate longitudinal movement of the hook within the opening when the wave spring is compressed beyond a preload state.

[0014] In certain aspects of the present disclosure, the channel member includes a distal portion and a proximal portion, the distal portion of the channel member defining spaced apart notches on opposite sides of a bottom wall of the channel member.

[0015] In an embodiment of the present disclosure, the spring includes a wave spring having a distal portion including two spaced apart hooks, the hooks being received within spaced apart notches in the channel member to secure the distal portion of the wave spring to the channel member.

[0016] In some aspects of the present disclosure, the hook is longitudinally movable within the notch in the channel member when the wave spring is compressed beyond a preload state.

[0017] In certain aspects of the present disclosure, each of the pushers includes at least one pusher plate and each of the staples includes a backspan and staple legs extending from the backspan.

[0018] In aspects of the present disclosure, the pusher plates each have an upper surface that defines a staple channel that receives the backspan of the staple to support the staple on the pusher plate.

[0019] In some aspects of the present disclosure, each of the pusher plates includes a rounded surface positioned on each side of the staple channel, the rounded surfaces configured to direct the staple legs of a respective one of the staples outward from the backspan as the staple is formed.

[0020] In certain aspects of the present disclosure, each of the pusher plates includes a chamfered surface positioned on each side of the staple channel, the chamfered surfaces configured to direct the staple legs of a respective one of the staples outward from the backspan when the staple is formed.

[0021] Another aspect of the present disclosure relates to a channel member having a body and a spring. The body has a proximal portion and a distal portion and includes side walls and a bottom wall that define a cavity. The bottom wall of the body of the channel member defines a knife slot. The spring is secured to the bottom wall of the channel member in a preloaded state.

[0022] Another aspect of the present disclosure relates to a cartridge assembly including a channel member, a staple cartridge, and a wave spring. The channel member has a proximal portion and a distal portion and includes side walls and a bottom wall defining a cavity. The bottom wall defines a knife slot. The staple cartridge is received within the cavity of the channel member and includes a cartridge body, staples, a pusher, and a staple guard. The cartridge body defines a knife slot and staple-receiving pockets arranged in a row on each side of the knife slot. The staples and the pusher are received in the staple-receiving pockets, and the pusher is movable from a lowered position within the staple-receiving pockets to a raised position to eject the staples from the staple-receiving pockets. The staple guard is supported on the cartridge body and positioned to retain the staples and the pusher within the cartridge body. The wave spring is supported on the channel member between the bottom wall of the channel member and the staple guard of the staple cartridge. The wave spring includes a base portion and two spring legs extending distally from the base portion along opposite sides of the knife slot, the two spring legs being secured to the bottom wall of the channel member in a preloaded state.

[0023] Yet another aspect of the present disclosure relates to a cartridge assembly including a channel member and a staple cartridge. The channel member has a proximal portion and a distal portion and includes side walls and a bottom wall defining a cavity. The bottom wall defines a knife slot. The staple cartridge is received within the cavity of the channel member and includes a cartridge body, staples, a pusher, and a staple guard. The cartridge body defines a knife slot and a row of staple-receiving pockets arranged on each side of the knife slot. The staples and the pusher are received in the staple-receiving pockets, and the pusher is movable from a lowered position within the staple-receiving pockets to a raised position to eject the staples from the staple-receiving pockets. The staple guard is supported on the cartridge body and positioned to retain the staples and the pusher within the cartridge body. The staple guard supports at least one spring member and includes a bottom wall defining the knife slot in longitudinal alignment with the knife slot of the cartridge body. At least one spring member is positioned to engage the bottom wall of the channel member to facilitate vertical movement of the bottom wall of the staple guard relative to the bottom wall of the channel member.

[0024] In an aspect of the present disclosure, the at least one spring member includes at least one spring member positioned on each side of the knife slot of the staple guard.

[0025] In some aspects of the present disclosure, the at least one spring member includes multiple spring members positioned on each side of the knife slot of the staple guard.

[0026] In certain aspects of the present disclosure, each of the plurality of spring members on each side of the knife slot is longitudinally aligned with at least one other spring member of the plurality of spring members.

[0027] In aspects of the present disclosure, each of the plurality of spring members on each side of the knife slot is longitudinally aligned with at least two other spring members of the plurality of spring members.

[0028] In some aspects of the present disclosure, the bottom wall of the staple guard includes at least one spring member.

[0029] In certain aspects of the present disclosure, at least one spring member is coupled to the bottom wall of the staple guard.

[0030] In an aspect of the present disclosure, the bottom wall of the staple guard defines an opening, and the at least one spring member includes a proximal extension and a distal extension that are received in the opening in the bottom wall of the staple guard to couple the at least one spring member to the staple guard.

[0031] In some aspects of the present disclosure, at least one spring member is a wave spring.

[0032] Another aspect of the present disclosure relates to a tool assembly including an anvil and a cartridge assembly. The cartridge assembly is coupled to the anvil to facilitate pivotable movement of the tool assembly between an open position and a clamped position. The cartridge assembly includes a channel member and a staple cartridge. The channel member has a proximal portion and a distal portion and includes side walls and a bottom wall defining a cavity. The bottom wall defines a knife slot. The staple cartridge is received within the cavity of the channel member and includes a cartridge body, staples, a pusher, and a staple guard. The cartridge body defines the knife slot and staple-receiving pockets arranged in a row on each side of the knife slot. The staples and the pusher are received within the staple-receiving pockets, and the pusher is movable from a lowered position within the staple-receiving pockets to a raised position to eject the staples from the staple-receiving pockets. The staple guard is supported on the cartridge body and positioned to retain the staples and the pusher within the cartridge body. The staple guard includes a bottom wall supporting at least one spring member and defining a knife slot longitudinally aligned with the knife slot of the cartridge body, the at least one spring member positioned to engage the bottom wall of the channel member and facilitating vertical movement of the staple cartridge relative to the anvil.

[0033] Yet another aspect of the present disclosure relates to a staple cartridge including a cartridge body, staples, a pusher, and a staple guard. The cartridge body defines a knife slot and staple-receiving pockets arranged in a row on each side of the knife slot. The staples and the pusher are received in the staple-receiving pockets, and the pusher is movable from a lowered position within the staple-receiving pocket to an elevated position to eject the staples from the staple-receiving pockets. The staple guard is supported on the cartridge body and positioned to retain the staples and the pusher within the cartridge body. The staple guard includes a bottom wall defining a knife slot that is longitudinally aligned with the knife slot of the channel member. The bottom wall of the staple guard supports spring members positioned on either side of the knife slot of the staple guard.

[0034] Other aspects of the present disclosure will be understood from the following description. [Brief explanation of the drawings]

[0035] Various aspects of the disclosed surgical stapling device are described herein below with reference to the drawings, in which:

[0036] [Figure 1] FIG. 10 is a side perspective view of a surgical stapling device including aspects of the present disclosure with the tool assembly of the surgical stapling device in an open position;

[0037] [Figure 2] 2 is an enlarged view of the indicated area of ​​detail shown in FIG. 1;

[0038] [Figure 3] FIG. 3 is a side perspective view of a cartridge assembly of the tool assembly shown in FIG. 2.

[0039] [Figure 3A] FIG. 4 is an enlarged view of the indicated area of ​​detail shown in FIG. 3;

[0040] [Figure 4] FIG. 4 is a side perspective view of the cartridge assembly shown in FIG. 3 with the staple cartridge separated from the channel member of the cartridge assembly;

[0041] [Figure 5] FIG. 5 is an exploded view of the cartridge assembly shown in FIG. 4.

[0042] [Figure 5A] FIG. 10 is a side view of the tool assembly of the stapling device 10 with thin tissue clamped between the anvil and cartridge assembly.

[0043] [Figure 5B] FIG. 10 is a side view of the tool assembly of the stapling device 10 with thick tissue clamped between the anvil and cartridge assembly.

[0044] [Figure 5C] FIG. 10 is a side view of the tool assembly of the stapling device 10 with tissue having uneven thickness clamped between the anvil and cartridge assembly.

[0045] [Figure 5D] 5D is a cross-sectional view taken along section line 5D-5D of FIG. 5.

[0046] [Figure 6] 6 is a top perspective view of the channel member and wave spring of the cartridge assembly shown in FIG. 5, with the wave spring secured to the channel member. FIG.

[0047] [Figure 7] FIG. 6 is a side perspective view, with parts separated, of an alternative version of the channel member and wave spring of the cartridge assembly shown in FIG. 5;

[0048] [Figure 8]8 is a top perspective view of the channel member and wave spring shown in FIG. 7, with the wave spring secured to the channel member.

[0049] [Figure 9] 9 is a cross-sectional view taken along section line 9-9 of FIG. 8.

[0050] [Figure 10] 10 is a cross-sectional view taken along the longitudinal axis of a channel member when a wave spring is secured to the channel member. FIG.

[0051] [Figure 11] 11 is a cross-sectional view of the channel member and wave spring shown in FIG. 10 with a staple cartridge loaded within the channel member;

[0052] [Figure 12] FIG. 12 is an enlarged view of the indicated area of ​​detail shown in FIG.

[0053] [Figure 13] 2 is a side cross-sectional view taken along the longitudinal axis of the cartridge assembly of the stapling device shown in FIG. 1 when fired; FIG.

[0054] [Figure 14] FIG. 6 is a side perspective view, with parts separated, of another alternative version of the channel member and wave spring of the cartridge assembly shown in FIG. 5;

[0055] [Figure 15] 15 is an enlarged perspective view from below of the assembled channel member and distal portion of the wave spring shown in FIG. 14. FIG.

[0056] [Figure 16] FIG. 6 is a side perspective view from above of a distal portion of another alternative version of the wave spring of the cartridge assembly shown in FIG. 5.

[0057] [Figure 17]FIG. 17 is a side view of the distal portion of the wave spring shown in FIG. 16.

[0058] [Figure 18] 17 is a top side perspective view of the wave spring shown in FIG. 16 assembled into a channel member. FIG.

[0059] [Figure 19] FIG. 6 is a top side perspective view of another alternative version of the channel member and wave spring of the cartridge assembly shown in FIG. 5.

[0060] [Figure 20] FIG. 20 is a top perspective view of the distal portion of the wave spring shown in FIG. 19.

[0061] [Figure 21] FIG. 5 is a bottom perspective view of an alternative version of the staple cartridge of the cartridge assembly shown in FIG. 4;

[0062] [Figure 22] FIG. 22 is a side view of the staple cartridge shown in FIG. 21;

[0063] [Figure 23] FIG. 5 is a bottom perspective view of another alternative version of the staple cartridge of the cartridge assembly shown in FIG. 4;

[0064] [Figure 24] 24 is a bottom perspective view of the staple cartridge of the cartridge assembly shown in FIG. 23 with the wave spring separated from the staple guard of the staple cartridge;

[0065] [Figure 25] FIG. 4 is a side perspective view of a distal portion of another version of the cartridge assembly shown in FIG. 3.

[0066] [Figure 26]FIG. 26 is an enlarged view of the indicated area of ​​detail shown in FIG. 25;

[0067] [Figure 27] FIG. 26 is a perspective view from the distal end of the pusher and staple of the cartridge assembly shown in FIG. 25 after the staple has been formed;

[0068] [Figure 28] 28 is a cross-sectional view taken along section line 28-28 of FIG. 27.

[0069] [Figure 29] 26 is a perspective view from the distal end of an alternative version of the pusher and staple of the cartridge assembly shown in FIG. 25 after the staple has been formed.

[0070] [Figure 30] 30 is a cross-sectional view taken along section line 30-30 of FIG. 29.

[0071] [Figure 31] FIG. 5 is a side perspective view of a portion of an alternative version of the cartridge body of the staple cartridge shown in FIG. 4;

[0072] [Figure 32] FIG. 32 is a top perspective view of the cartridge body shown in FIG. 31 as the staples are formed.

[0073] [Figure 33] 5 is an alternative version of the cartridge body of the staple cartridge shown in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0074] The disclosed surgical stapling device will now be described in detail with reference to the drawings, in which like reference numerals indicate identical or corresponding elements in each of the several views. However, it should be understood that the disclosed aspects are merely exemplary of the present disclosure, which may be embodied in various forms. To avoid obscuring the present disclosure with unnecessary detail, well-known functions or configurations have not been described in detail. Therefore, specific structural and functional details disclosed herein should not be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art to variously employ the present disclosure in substantially any appropriately detailed structure.

[0075] In this description, the term "proximal" is generally used to refer to the portion of the device that is closer to the clinician when using the device in a normal manner, and the term "distal" is generally used to refer to the portion of the device that is further from the clinician when using the device in a normal manner. In addition, the term "clinician" is generally used to refer to medical personnel, including doctors, nurses, and support personnel. Furthermore, directional terms such as front, back, superior, inferior, top, bottom, and similar terms are used to aid in understanding this specification and are not intended to limit the present disclosure.

[0076] Surgical stapling devices are used in a variety of surgical procedures to treat tissues having various thicknesses. Typically, during a surgical procedure, a surgeon selects a staple size to be used during the surgical procedure based on various factors, such as the tissue being treated, the type of procedure being performed, personal preference, and personal experience. The inventors have recognized, among other things, that a problem to be solved may include a surgeon selecting a stapling device having a staple size that does not provide effective hemostasis. The present disclosure may help provide a solution to this problem, such as by providing a stapling device cartridge assembly that can accommodate tissues of different thicknesses. Providing a cartridge assembly that can accommodate a wide range of tissue thicknesses may simplify staple size selection, reduce surgeon error, and therefore improve clinical outcomes. Additionally, because fewer options are needed to cover the range of target tissue thicknesses, the present disclosure simplifies logistics and provides savings to hospitals because they do not need to have a large number of options in inventory.

[0077] The disclosed surgical stapling device includes a tool assembly having a cartridge assembly for accommodating tissue of different thicknesses. The cartridge assembly includes a channel member and a staple cartridge received within the channel member for movement relative to the channel member between positions to alter the tissue gap defined between the staple cartridge and the anvil of the stapling device. The cartridge assembly can also include features formed on a pusher or cartridge body of the staple cartridge of the cartridge assembly to improve staple formation when stapling thin tissue.

[0078] 1 illustrates a surgical stapling device, generally designated as stapling device 10, including a handle assembly 12, an elongated body or adapter assembly 14, and a tool assembly 16. Handle assembly 12 is powered and includes a stationary handgrip 18 and one or more actuator buttons 20. Actuation buttons 20 are operable to actuate various functions of tool assembly 16 via adapter assembly 14, including approximation, stapling, and cutting. In certain aspects of the present disclosure, handle assembly 12 supports a battery (not shown) that provides power to handle assembly 12 to operate stapling device 10. While stapling device 10 is shown as a powered stapling device, it is envisioned that tool assembly 16 of the present disclosure is suitable for use in manual surgical stapling devices as well as robotically controlled stapling devices.

[0079] Adapter assembly 14 includes proximal portion 14a and distal portion 14b. Proximal portion 14a is coupled to handle assembly 12, and distal portion 14b supports tool assembly 16. In an embodiment of the present disclosure, tool assembly 16 is removably supported on distal portion 14b of adapter assembly 14 and forms part of a reloading assembly 21 that can be replaced after stapling apparatus 10 has been fired to facilitate reuse of stapling apparatus 10. It is also envisioned that tool assembly 16 can be fixedly coupled to distal portion 14b of adapter assembly 14.

[0080] Tool assembly 16 of stapling device 10 includes a cartridge assembly 30 and an anvil 32. Cartridge assembly 30 and anvil 32 are coupled together such that tool assembly 16 can pivot between an open position (FIG. 1) and a clamped position. In the clamped position, anvil 32 and cartridge assembly 30 are aligned alongside one another to define a tissue gap for receiving tissue. Anvil 32 includes a tissue-engaging surface 32a (FIG. 5A) that defines staple-forming pockets (not shown).

[0081] 2-5 illustrate cartridge assembly 30, including channel member 34 and staple cartridge 40. Channel member 34 includes side walls 36 and a bottom wall 38 (FIG. 4) that define a cavity 34a (FIG. 5) that receives staple cartridge 40. Bottom wall 38 defines knife slot 38a. In an embodiment of the present disclosure, staple cartridge 40 can be removably received within cavity 34a of channel member 34 to allow replacement of staple cartridge 40 after each firing of stapling device 10 (FIG. 1), facilitating reuse of stapling device 10 (FIG. 1).

[0082] FIG. 5 shows an exploded view of staple cartridge 40 including cartridge body 42, staples 44, pusher 46, actuation sled 48, and staple guard 50. Cartridge body 42 of staple cartridge 40 is received within cavity 34a defined by channel member 34 and includes tissue-engaging surface 52. Cartridge body 42 defines knife slot 54 and a plurality of staple-receiving pockets 56 arranged in a row on each side of knife slot 54. Knife slot 54 and staple-receiving pockets 56 open onto tissue-engaging surface 52 of cartridge body 42. In a specific embodiment of the present disclosure, tissue-engaging surface 52 of staple cartridge 40 has a stepped configuration with a raised surface adjacent central knife slot 54 and a lower surface positioned outwardly of central knife slot 54, toward sidewall 36 of channel member 34. Each of staple-receiving pockets 56 receives a staple 44 ( FIG. 3 ) and at least a portion of one of pushers 46. In some embodiments of the present disclosure, staples 44 in the inner row of staple receiving pockets 56 are shorter in length than staples 46 in the outer row of staple receiving pockets 56. Actuation sled 48 is movable distally from the proximal end of cartridge body 42 to sequentially engage pusher 46 and force pusher 46 upwardly, as seen in FIG. 5 , ejecting staples 44 from staple receiving pockets 56 of cartridge body 42, through tissue engaging surface 52, and into engagement with anvil 32 ( FIG. 1 ).

[0083] Staple guard 50 is secured to the bottom side of cartridge body 42 to retain staples 44, pusher 46, and actuation sled 48 within cartridge body 42. In embodiments of the present disclosure, staple guard 50 includes flexible links 58 that define openings 60 that receive protrusions 62 formed on the exterior surface of cartridge body 42 to secure staple guard 50 to cartridge body 42. In some embodiments of the present disclosure, staple guard 50 also includes hooked fingers 64 that engage a proximal portion of cartridge body 42 to secure staple guard 50 to cartridge body 42. U.S. Patent No. 6,241,139 discloses exemplary embodiments of the structure and operation of a staple cartridge for a surgical stapling apparatus.

[0084] The cartridge body 42 of the staple cartridge 40 includes a tab 66, and the channel member defines a window 68 that receives the tab 66. The window 68 is sized to allow the tab 66 of the cartridge body 42 to move vertically within the window 68 but to prevent substantial longitudinal movement of the staple cartridge 40 within the cavity 34a of the channel member 34. In embodiments of the present disclosure, the upper end of the window 68 is surrounded by a bar 68a that prevents the tab 66 from exiting the window 68. In some embodiments of the present disclosure, the tab 66 can have convex wall portions 66a on opposing ends and / or side walls of the tab 66. The convex wall portions 66a allow the cartridge body 42 to pitch (FIG. 5C) and / or roll (FIG. 5D) within the cavity 34a of the channel member 34 to account for differences in tissue thickness along the staple line. It should be noted that tab 66 need not have a convex wall portion to accommodate pitching and rolling of cartridge body 42 within cavity 34a of channel member 34. Alternatively, window 68 and tab 66 can be dimensioned to facilitate pitching and rolling of cartridge body 42. Thus, even if the staples 44 are the same size along each of the rows of staples 44, movement of cartridge body 42 within cavity 34a of channel member 34 can allow the formed configuration of the staples to vary along the staple line in a single firing of stapling device 10.

[0085] Cartridge assembly 30 includes one or more elongated springs or biasing members 70 positioned between staple guard 50 and bottom wall 38 of channel member 34. The biasing members urge staple cartridge 40 upward within cavity 34a of channel member 34 toward anvil 32. In embodiments of the present disclosure, biasing members 70 may be elongated wave springs 72 positioned on either side of knife slot 38a between staple guard 50 of staple cartridge 40 and bottom wall 38 of channel member 34 and having a sinusoidal shape along the longitudinal axis of channel member 34. In embodiments of the present disclosure, wave springs 72 may be spot welded to channel member 34 and compressible to allow vertical movement of staple cartridge 40 within cavity 34a of channel member 34. In some embodiments of the present disclosure, spot welds 72a (FIG. 6) are positioned at a central portion of wave spring 70 and a central portion of channel member 34. However, the wave spring 72 can be spot welded or secured to the channel member 34 using other fastening techniques at any location along the length of the wave spring 72 that allows the wave spring 72 to compress so that the cartridge body 42 can move vertically within the channel member 34.

[0086] When tissue is positioned between the anvil 32 and the cartridge assembly 30, and the tool assembly 16 is moved from the open position to the clamping position, the force of the tissue on the cartridge body 42 of the staple cartridge 40 compresses the biasing member 70, causing the staple cartridge 40 to move vertically (or toward the bottom wall 38 of the channel member 34) within the cavity 34a of the channel member 34. The amount of movement of the staple cartridge 40 within the cavity 34a of the channel member 34 during clamping and firing of the stapling device 10 (FIG. 1) will depend on the thickness of the tissue. More specifically, the staple cartridge 40 may move downwardly a greater distance within the cavity 34a of the channel member 34 as the tissue thickness increases. As the staple cartridge 40 moves within the channel member 34, the tabs 66 move within the windows 68 defined in the side walls 36 of the channel member 34. As described above, tabs 66 and windows 68 allow staple cartridge 40 to move vertically within cavity 34a defined by channel member 34, but prevent longitudinal movement of staple cartridge 40 within cavity 34a. As staple cartridge 40 moves within channel member 34, the relative position of pusher 46 changes with respect to anvil 32, which affects staple formation. More specifically, when thicker tissue is clamped, the wave spring 72 supporting the staple cartridge 40 compresses, allowing the cartridge body 42 to move within the cavity 34a of the channel member 34 to define a first tissue gap G2 (FIG. 5B) between the tissue engaging surface 52 of the cartridge body 42 and the tissue engaging surface 32a of the anvil 32; when thinner tissue is clamped, the wave spring 72 supporting the staple cartridge 40 compresses, allowing the cartridge body 42 to move within the cavity 34a of the channel member 34 to define a second tissue gap G1 (FIG. 5A) between the tissue engaging surface 52 of the cartridge body 42 and the tissue engaging surface 32a of the anvil 32, the first tissue gap G2 being larger than the second tissue gap G1.

[0087] The staples 44 in the inner, middle, and outer rows of staples 44 can have the same unformed size. Alternatively, the staples 44 in the inner, middle, and outer rows of staples 44 can have different unformed sizes in each of the rows of staples. For example, the staples 44 in the inner row of staples 44 can have a smaller unformed size than the staples in the middle and / or outer rows of staples 44. Additionally, the tissue-engaging surface 52 (FIG. 5A) of the cartridge body 42 of the staple cartridge 40 can be planar, or alternatively, the tissue-engaging surface 52 can be stepped.

[0088] It should be noted that the staples 44 may have different formed sizes, although they have the same unformed size in a particular row of staples 44. This difference results from movement of the cartridge body 42 within the cavity 34a of the channel member 34 caused by variations in tissue thickness along the length of the staple line. As described above, the cartridge body 42 can rock back and forth within the cavity 34a of the channel member 34. This can occur when the tissue at the distal portion of the tool assembly 16 is thicker than the tissue at the proximal portion of the tool assembly 16, such that the tissue gap at the distal portion of the cartridge body 42 is larger than the tissue gap at the proximal portion of the cartridge body 42.

[0089] 7-9 show an alternative version of the channel member and wave spring of cartridge assembly 30 (FIG. 3), generally designated as channel member 134 and wave spring 170. Channel member 134 is similar to channel member 34 (FIG. 5) and includes side walls 136 and a bottom wall 138 that together define a cavity 134a for receiving staple cartridge 40 (FIG. 4). Channel member bottom wall 138 defines a knife slot 138a and an opening 140 that extends through bottom wall 138 of channel member 134 and communicates with knife slot 138a.

[0090] The wave spring 170 includes a base portion 172 and two elongated spring legs 174 extending from the base portion 170 and positioned along either side of the knife slot 138a (FIG. 8). The base portion 172 of the wave spring 170 supports or includes a hook 176. The wave spring 170 is secured to the bottom wall 138 of the channel member 134 by positioning the hook 176 of the wave spring 170 through the opening 140. More specifically, as shown in FIGS. 8 and 9, the hook 176 is positioned through the opening 140 and engages the outer surface of the channel member 134 to secure the distal end of the wave spring 170 to the channel member 134. The opening 140 of the channel member 134 has a length that is longer than the length of the hook 176 of the wave spring 170 to facilitate longitudinal movement of the hook 176 within the opening 140. In an embodiment of the present disclosure, the bottom wall 138 of the channel member 134 includes a finger 144 (FIG. 9) that extends partially across the opening 140, and the hook 176 is received around the finger 144 to secure the distal portion of the wave spring 170 to the distal portion of the channel member 134.

[0091] It is envisioned that other fastening structures or techniques that allow for spring compression within cavity 134a of channel member 134 may be used instead of hooks 176 and openings 140 to secure wave spring 170 to channel member 134. For example, wave spring may include a pin (not shown) and channel member 134 may define a slot (not shown) that receives the pin.

[0092] When the distal portion of wave spring 170 is secured to the distal portion of channel member 134, two elongated spring legs 174 of wave spring 170 extend proximally from base portion 172 of wave spring 170 along either side of knife slot 138a. Each of spring legs 174 of wave spring 170 has a sinusoidal shape and is compressible to facilitate vertical movement of staple cartridge 40 within cavity 134a of channel member 134.

[0093] 10 illustrates the wave spring 170 as it is secured to the channel member 134 during manufacture of the cartridge assembly 30. In an embodiment of the present disclosure, when the wave spring 170 is secured to the bottom wall 138 of the channel member 134, the wave spring 170 is preloaded to facilitate placement of the staple cartridge 40 within the cavity 134a of the channel member 134 by a clinician. In an embodiment of the present disclosure, during the manufacturing process, the wave spring 170 is preloaded within the cavity 134a of the channel member 134 by inserting the hooks 176 into the openings 140 of the channel member 134 to receive the fingers 144, subsequently compressing the wave spring 170 in the direction of arrow "A," and finally welding the proximal portions of the spring legs 174 to the bottom wall 138 of the channel member 134 while partially compressing or preloading the spring legs 174. As shown, the distal portion of the wave spring 170 moves in the direction of arrow "B" when the wave spring 170 is preloaded. It is envisioned that other portions of the wave spring 170 may be welded or secured to the channel member 134 at locations other than the proximal portions of the spring legs 174 (e.g., a central portion of the wave spring 170).

[0094] In embodiments of the present disclosure, wave spring 170 is secured to the bottom wall 138 of channel member 134 in a preloaded state to permit vertical movement of staple cartridge 40 within cavity 134a of channel member 134. In one embodiment of the present disclosure, staple cartridge 40 moves vertically within cavity 134a of channel member 134 by approximately 0.015 inches (0.381 millimeters (mm)) to approximately 0.025 inches (0.635 millimeters (mm)). In certain embodiments of the present disclosure, wave spring 170 is secured to the bottom wall 138 of channel member 134 in a preloaded state to permit vertical movement of staple cartridge 40 ( FIG. 4 ) by approximately 0.020 inches (0.0508 millimeters (mm)) within cavity 134a of channel member 134. Alternatively, wave spring 170 and channel member 134 can be configured to provide a greater range of movement of staple cartridge 40 within channel member 134.

[0095] Preloading of the wave spring 170 can be achieved during the manufacturing process by positioning the channel member 134 and wave spring 170 in a fixture (not shown), pre-compressing the wave spring 170, and then spot welding or fastening the proximal portions of the spring legs 174 to the channel member 134 using some other fastening technique.

[0096] 11 and 12 show staple cartridge 40 (FIG. 5) when loaded into cavity 134a of channel member 134 and wave spring 170 is in a preloaded state within cavity 134a of channel member 134. When staple cartridge 40 is loaded into cavity 134a of channel member 134, tab 66 on cartridge body 42 (FIG. 5) of staple cartridge 40 (FIG. 5) is received within window 168 of channel member 134. When staple cartridge 40 is received within cavity 134a of channel member 134, guard 50 is seated on wave spring 170 and tab 66 (FIG. 5A) of cartridge body 42 is positioned at the upper end of window 168. When tool assembly 16 is moved to a clamping position around thin tissue "T1," tab 66 is positioned at the upper end of window 168, and tissue gap "G1" (FIG. 5A) defined between staple cartridge 40 of the cartridge assembly and anvil 32 is at its minimum distance. When tool assembly 16 is moved to a clamping position around thick tissue "T2," tab 66 is positioned at the lower end of window 168, and tissue gap "G2" (FIG. 5B) defined between staple cartridge 40 of the cartridge assembly and anvil 32 is at its maximum distance. As explained, the distance from the bottom surface of tab 66 to the bottom surface of window 68 is the maximum distance that cartridge body 42 can travel within cavity 34a of channel member 34. Note that pre-compressing wave spring 170 allows staple cartridge 40 to be inserted into cavity 134a of channel member 134 with minimal force.

[0097] FIG. 13 shows cartridge assembly 30 (FIG. 3), including staple cartridge 40 and channel member 134, when stapling device 10 (FIG. 1) is fired. When stapling device 10 is fired and a clamping member (not shown) is driven through tool assembly 16, the force exerted by the tissue on tissue engaging surface 52 of cartridge body 42 of staple cartridge 40 causes staple cartridge 40 to move downward in the direction of arrow "C" within cavity 134a of channel member 134 to accommodate thicker tissue. The extent of movement of staple cartridge 40 within cavity 134a of channel member 134 is proportional to the thickness of the tissue compressed between staple cartridge 40 and anvil 32 (FIG. 1). As discussed above, proximal portions of spring legs 174 of wave spring 170 are secured to bottom wall 138 of channel member 134. Thus, as staple cartridge 40 moves within cavity 134a of channel member 134 during firing, further compressing spring 134 from the preloaded state, wave spring 170 flattens such that the distal end of wave spring 170 moves distally in the direction of arrow "D" within opening 140 of channel member 134. Hooks 176 of wave spring 170 and fingers 144 of channel member 134 should be sized to prevent separation of hooks 176 from fingers 144 during maximum compression of wave spring 170.

[0098] 14 and 15 show an alternative version of the channel member and wave spring of cartridge assembly 30 (FIG. 3), generally designated channel member 234 and wave spring 270. Channel member 234 is similar to channel members 34, 134 described above, except that opening 140 (FIG. 7) in channel member 134 is replaced with two spaced-apart notches 240a, 240b. Wave spring 270 is similar to wave spring 170 (FIG. 7), except that hook 176 is replaced with two spaced-apart hooks 276a, 276b supported on a base portion 272 of wave spring 270. Each of hooks 276a, 276b is received in one of notches 240a, 240b in channel member 234, and spring legs 274 of wave spring 270 extend proximally from base portion 272. Providing two spaced apart notches 240a, 240b and two hooks 276a, 276b, as compared to a single larger opening and one large hook, allows for better maintenance of the structural integrity of the channel member 234. The wave spring 270 can be secured to the bottom wall 238 of the channel member 234 in a preloaded state, as described above with respect to the wave spring 170.

[0099] 16-18 illustrate another alternative version of the generally depicted channel member and wave spring as channel member 334 (FIG. 18) and wave spring 370. Channel member 334 is similar to channel member 134 (FIG. 8) and includes openings 340 (FIG. 18). Wave spring 370 is similar to spring 170 (FIG. 7), except that base portions 372 and hooks 376 are formed separately from each of the spring legs 374, and the spring legs 374 are joined to the base portion 372, such as by welding or crimping. Hooks 376 of wave spring 370 are secured to channel member 334, as described above with respect to wave spring 170 and channel member 134. As shown in FIG. 18, hooks 376 are movable within openings 340 when wave spring 370 is compressed. The wave spring 370 may be secured in a preloaded state to the bottom wall 338 of the channel member 334 as described above with respect to the wave spring 170 .

[0100] 19 and 20 show another version of the generally designated channel member and spring as channel member 434 and spring 470. Channel member 434 is similar to channel member 34 (FIG. 4) and includes side walls 436 and a bottom wall 438 that define a cavity 438a that receives staple cartridge 40 (FIG. 5). Bottom wall 438 supports spring 470 and defines knife slot 438a.

[0101] Spring 470 includes a base portion 472 and two spaced apart elongated semicircular portions 474 extending proximally from base portion 472. Semicircular portions 474 are positioned on either side of knife slot 438a and extend along most of the length of channel member 434. Base portion 472 of spring 470 includes a central portion 472a that is secured to a distal portion of bottom wall 438 of channel member 434 by spot welding.

[0102] Staple cartridge 40 (FIG. 5) is supported within cavity 438a of channel member 434 and rests on spring 470. When a downward force is applied to staple cartridge 40, semicircular portion 474 of spring 470 flattens, allowing staple cartridge 40 (FIG. 5) to move vertically within cavity 438a of channel member 434 to accommodate tissue of different thicknesses.

[0103] 21-22 illustrate an alternative version of a generally designated staple cartridge as staple cartridge 540. Staple cartridge 540 is similar to staple cartridge 40 (FIG. 5) and includes a cartridge body 542 and a staple guard 550. Cartridge body 542 defines staple receiving slots 56 (FIG. 5) and knife slot 54 (FIG. 5). Staple guard 550 includes a bottom wall 552 defining a knife slot 552a that is aligned with knife slot 54 (FIG. 5) in cartridge body 542. Bottom wall 552 includes curved spring members 570 positioned on either side of knife slot 54. In an embodiment of the present disclosure, spring members 570 curve outward from bottom wall 552 of staple guard 550 along a longitudinal axis of staple guard 550. In some embodiments of the present disclosure, the bottom wall 552 of the staple guard 550 includes a plurality of spring members 570 on each side of the knife slot 552a. In a particular embodiment of the present disclosure, the bottom wall 552 of the staple guard 550 includes six spring members 570 on each side of the knife slot 552a, each of the spring members 570 being longitudinally aligned with two other spring members 570.

[0104] When staple cartridge 540 is positioned within a channel member, such as channel member 434 (FIG. 19), spring member 570 rests on bottom wall 438 of channel member 434. When a force is applied to staple cartridge 540, spring member 570 flattens, allowing staple cartridge 540 to move vertically within cavity 438a of channel member 434 to accommodate tissue of different thicknesses.

[0105] 23 and 24 illustrate another version of a staple cartridge generally designated as staple cartridge 640. Staple cartridge 640 is similar to staple cartridge 540 (FIG. 21) and includes a cartridge body 642 and a staple guard 650. Cartridge body 642 defines staple receiving slots 56 (FIG. 5) and knife slot 54 (FIG. 5). Staple guard 650 includes a bottom wall 652 defining a knife slot 652a that is aligned with knife slot 54 (FIG. 5) in cartridge body 642. Staple cartridge 640 differs from staple cartridge 540 (FIG. 21) in that staple guard 650 includes a spring member 670 coupled to bottom wall 652 of staple guard 650. In an embodiment of the present disclosure, spring member 670 is in the form of a wave spring 672. Each of the wave springs 672 includes proximal and distal extensions 674 that are received within openings 676 in the bottom wall 652 of the staple guard 650 to secure the spring members 670 to the staple guard 650. In an embodiment of the present disclosure, the proximal and distal extensions 674 are dimensioned to be slidably received within the openings 676 of the staple guard 650, allowing the wave springs 672 to flatten and enable the staple cartridge 640 to move vertically within the cavity of a channel member, such as channel member 434 ( FIG. 19 ), to accommodate tissue of different thicknesses.

[0106] 25-28 illustrate another version of a staple cartridge generally designated as staple cartridge 740. Staple cartridge 740 includes staples 744 and a pusher 746. Pusher 746 is configured to improve staple formation in situations where staples 744 may be over-crimped. More specifically, each of staple pushers 746 (FIG. 27) includes one or more pusher plates 750. Each of pusher plates 746 defines a staple channel 752 configured to support a backspan 756 of one of staples 744. Pusher plate 750 also includes chamfered surfaces 754 positioned along either side of staple channel 752. Chamfered surfaces 754 are configured to direct legs 758 of a respective one of staples 744 outward from backspan 756 of staple 744 when staple 744 is formed by anvil 32 (FIG. 1).

[0107] 25 and 26 show tool assembly 16 when it is fired with pusher 746. When stapling device 10 (FIG. 1) is fired, pusher 746 is pushed through staple receiving slots 770 in cartridge body 772 of staple cartridge 740. When pusher 746 reaches a raised position within cartridge body 772, pusher plate 750 extends outward beyond tissue engaging surface 774 of cartridge body 772, exposing chamfered surface 754 of pusher plate 750. When the tissue to be stapled is thin and legs 758 of staples 744 curl back toward backspan 756 of staples 744, legs 758 engage chamfered surface 754 of pusher plate 750, directing legs 758 of staples 744 outward from backspan 756 to prevent malformation of staples 744.

[0108] 29 and 30 show an alternative version of the pusher generally shown as pusher 846. Pusher 846 is similar to pusher 746 (FIG. 27) except that chamfered surface 754 on pusher plate 750 is replaced with a rounded surface 854 on pusher plate 850. Pusher 846 functions similarly to pusher 746 and will not be described in further detail herein.

[0109] 31-33 show an alternative version of the cartridge body of the stapling device of FIG. 1 , generally designated as cartridge body 942. Cartridge body 942 defines a knife slot 954 and staple receiving pockets 956 positioned on each side of knife slot 954. Cartridge body 942 also defines scalloped pockets 958 positioned adjacent each of staple receiving pockets 956. Each of scalloped pockets 958 is configured to curl legs 960 of staples 962 upwardly toward anvil 32 ( FIG. 1 ) to prevent pointed tips 960 a of legs 960 of staples 962 from extending below backspan 964 of staples 962.

[0110] Although each aspect of the present disclosure is described separately, it is contemplated that each aspect of the present disclosure may be used with other aspects of the present disclosure in a single cartridge assembly. For example, a cartridge assembly having preloaded wave spring 170, 270, or 370 can also include pusher 746 or 846 and / or cartridge body 942. Similarly, a cartridge assembly including spring 470 can also include pusher 746 or 846 and / or cartridge body 942.

[0111] Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments of the present disclosure. It is contemplated that elements and features illustrated or described in connection with one exemplary embodiment of the present disclosure may be combined with other elements and features without departing from the scope of the present disclosure. Similarly, those skilled in the art will appreciate additional features and advantages of the present disclosure based on the above-described embodiments of the present disclosure. Accordingly, the present disclosure is not limited by what has been particularly shown and described, except as indicated by the appended claims.

Claims

1. 1. A cartridge assembly comprising: a channel member having a proximal portion and a distal portion, the channel member including side walls and a bottom wall defining a cavity, the bottom wall defining a knife slot; a staple cartridge received within the cavity of the channel member, the staple cartridge including a cartridge body, staples, a pusher, and a staple guard, the cartridge body defining a knife slot and a row of staple receiving pockets disposed on each side of the knife slot, the staples and the pusher being received in the staple receiving pockets, the pusher being movable from a lowered position within the staple receiving pockets to a raised position to eject the staples from the staple receiving pockets, and the staple guard being supported on the cartridge body and positioned to retain the staples and pusher within the cartridge body; a spring supported on the channel member between the bottom wall of the channel member and the staple guard of the staple cartridge, the spring being fixed to the bottom wall of the channel member in a preloaded state.

2. The cartridge assembly of claim 1 , wherein the channel member includes a distal portion and a proximal portion, the distal portion of the channel member defining an opening extending through the bottom wall of the channel member.

3. 3. The cartridge assembly of claim 2, wherein the spring comprises a wave spring having a distal portion including a hook, the hook being received in the opening of the channel member to secure the distal portion of the wave spring to the channel member.

4. The cartridge assembly of claim 3 , wherein the wave spring includes a base portion and two elongated spring legs extending distally from the base portion on opposite sides of the knife slot, the base portion supporting the hook.

5. The cartridge assembly of claim 4 , wherein each of the two elongated spring legs includes a proximal portion secured to the bottom wall of the channel member to secure the wave spring to the channel member in the preloaded state.

6. The cartridge assembly of claim 5 , wherein the proximal portion of each of the two elongated spring legs is welded to the bottom wall of the channel member.

7. The cartridge assembly of claim 6 , wherein the channel member includes a finger extending into the opening, the hook being received around the finger.

8. The cartridge assembly of claim 7 , wherein the base portion is formed separately from the two elongated spring legs, and the spring legs are fixed to the base portion.

9. The cartridge assembly of claim 5 , wherein the opening is sized to facilitate longitudinal movement of the hook within the opening when the wave spring is compressed beyond the preload state.

10. The cartridge assembly of claim 1 , wherein the channel member includes a distal portion and a proximal portion, the distal portion of the channel member defining spaced apart notches on opposite sides of the bottom wall of the channel member.

11. 11. The cartridge assembly of claim 10, wherein the spring comprises a wave spring having a distal portion including two spaced apart hooks, the hooks being received within the spaced apart notches of the channel member to secure the distal portion of the wave spring to the channel member.

12. The cartridge assembly of claim 11 , wherein the hook is longitudinally movable within the notch in the channel member when the wave spring is compressed beyond the preload state.

13. 2. The cartridge assembly of claim 1, wherein each of the pushers includes at least one pusher plate, each of the staples includes a backspan and staple legs extending from the backspan, and each of the pusher plates has an upper surface defining a staple channel that receives the backspan of the staple to support the staple on the pusher plate.

14. 14. The cartridge assembly of claim 13, wherein each of the pusher plates includes a rounded surface positioned on each side of the staple channel, the rounded surfaces configured to direct the staple legs of a respective one of the staples outward from the backspan when the staple is formed.

15. 14. The cartridge assembly of claim 13, wherein each of the pusher plates includes a chamfered surface positioned on each side of the staple channel, the chamfered surfaces configured to direct the staple legs of a respective one of the staples outward from the backspan when the staple is formed.

16. A channel member, a body having a proximal portion and a distal portion, the body including a side wall and a bottom wall defining a cavity, the bottom wall defining a knife slot; a spring secured to the bottom wall of the body in a preloaded state.

17. 17. The channel member of claim 16, wherein the distal portion of the body of the channel member defines an opening extending through the bottom wall of the body, and the spring comprises a wave spring having a distal portion including a hook, the hook being received within the opening of the body of the channel member to secure the distal portion of the wave spring to the body.

18. 18. The channel member of claim 17, wherein the wave spring includes a base portion and two elongated spring legs extending distally from the base portion on opposite sides of the knife slot, the base portion supporting the hook, and each of the two elongated spring legs including a proximal portion secured to the bottom wall of the body of the channel member to secure the wave spring to the body of the channel member in the preloaded state.

19. 17. The channel member of claim 16, wherein the distal portion of the channel member body defines spaced notches on either side of the bottom wall of the channel member body, and the spring comprises a wave spring having a distal portion including two spaced hooks that are received within the spaced notches of the channel member body to secure the distal portion of the wave spring to the channel member body.

20. 1. A cartridge assembly comprising: a channel member having a proximal portion and a distal portion, the channel member including side walls and a bottom wall defining a cavity, the bottom wall defining a knife slot; a staple cartridge received within the cavity of the channel member, the staple cartridge including a cartridge body, staples, a pusher, and a staple guard, the cartridge body defining a knife slot and a row of staple receiving pockets disposed on each side of the knife slot, the staples and the pusher being received in the staple receiving pockets, the pushers being movable within the staple receiving pockets from a lowered position to a raised position to eject the staples from the staple receiving pockets, and the staple guard being supported on the cartridge body and positioned to retain the staples and pusher within the cartridge body; a wave spring supported on the channel member between the bottom wall of the channel member and the staple guard of the staple cartridge, the wave spring including a base portion and two spring legs extending distally from the base portion along opposite sides of the knife slot, the two spring legs being fixed to the bottom wall of the channel member in a preloaded state.

Images