Suturing reload assembly with detachable knife

Abstract

A surgical stapling device includes an anvil assembly and a reload assembly including a knife and a knife carriage. The knife is detachably coupled to the knife carriage and is embedded in a cutting loop of the anvil assembly when the stapling device is fired. The knife is separable from the knife carriage after a predetermined force is applied to the knife. The predetermined force is applied to the knife after the stapling device is fired by moving the anvil assembly relative to the reload assembly from a clamped position to an open position.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62 / 981,636, filed February 26, 2020, the entire disclosure of which is incorporated by reference herein. TECHNICAL FIELD

[0003] The present disclosure relates generally to surgical stapling devices, and more particularly to circular surgical stapling devices including a knife for cutting tissue. BACKGROUND

[0004] Circular stapling devices generally include a housing or reload assembly having a cartridge, a pusher, and an annular knife. The cartridge supports one or more annular rows of staples, and the pusher is movable within the cartridge to eject the staples from the cartridge. The annular knife is positioned radially inward of the annular rows of staples and is movable from a retracted position to an advanced position to cut or core tissue. The annular knife can be moved synchronously with the pusher or can be moved independently of the pusher to cut tissue during a surgical procedure, such as an anastomotic procedure.

[0005] During an anastomotic procedure, two tubular sections of tissue are connected to one another, and tissue within the tubular sections is cored with a knife to define a hollow passageway between the connected tubular sections. Generally, after the sections of tissue are cut, a tissue torus remains within the annular knife of the reload assembly. The clinician removes the tissue torus from within the annular knife when the reload assembly is removed from the patient.

[0006] After actuating the circular stapling device to cut tissue during an anastomotic procedure, the knife is moved from an advanced position in which a cutting edge of the annular knife is exposed to a retracted position in which the cutting edge of the knife is recessed within and shielded by the cartridge of the reload assembly. During removal of the tissue torus from within the annular knife, the clinician can inadvertently expose the cutting edge of the knife by pulling the cutting edge of the knife in a distal direction. Exposure of the cutting edge of the knife presents a hazard to the clinician operating the stapling device. SUMMARY

[0007] The technology of the present disclosure generally relates to circular stapling devices having a knife for cutting tissue. In aspects of the present disclosure, a housing stapling device includes an anvil assembly and a reload assembly including a knife and a knife holder. The knife is detachably coupled to the knife holder and is embedded in a cutting ring of the anvil assembly when the stapling device is fired. The knife is separable from the knife holder after a predetermined force is applied to the knife. The predetermined force is applied to the knife after the stapling device is fired by moving the anvil assembly relative to the reload assembly from a clamped position to an open position.

[0008] One aspect of the present disclosure relates to a reload assembly including a housing case, a staple cartridge, a pusher member, a knife holder, and a knife. The housing case defines a cavity and has a proximal portion and a distal portion. The staple cartridge is supported on the distal portion of the housing case and supports a plurality of staples. The pusher member is movable within the housing case between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge. The pusher member defines a longitudinal bore. The knife holder is supported within the longitudinal bore of the pusher member and has a distal portion defining a first engagement portion. The knife holder is movable within the housing case between a retracted position and an advanced position. The knife has a proximal portion and a distal portion. The proximal portion defines a second engagement portion that is coupled to the first engagement portion to detachably secure the knife to the knife holder. Upon application of a predetermined force to the knife in a distal direction, the knife can decouple from the first engagement portion of the knife holder.

[0009] In aspects of the present disclosure, the knife is annular.

[0010] In some aspects of the present disclosure, the first engagement portion is defined by a plurality of resilient fingers formed on the distal portion of the knife holder.

[0011] In certain aspects of the present disclosure, each of the plurality of resilient fingers defines a concave surface to define an annular recess about the distal portion of the knife holder.

[0012] In aspects of the present disclosure, the second engagement portion is formed on the proximal portion of the knife and includes an annular protrusion that is received within an annular recess defined by the plurality of resilient fingers of the knife holder to detachably secure the knife to the knife holder.

[0013] In aspects of the present disclosure, the second engagement portion is formed on the proximal portion of the knife by inverting the proximal portion of the knife.

[0014] Another aspect of this disclosure relates to a surgical stapling device comprising an adapter assembly, a reload assembly, and an anvil assembly. The adapter assembly has a distal end portion. The reload assembly is secured to the distal end portion of the adapter assembly and comprises a housing shell, a staple cartridge assembly, a pusher member, a knife holder, and a knife. The housing shell defines a cavity and has a proximal portion and a distal portion. The staple cartridge is supported on the distal portion of the housing shell and supports a plurality of staples. The pusher member is movable within the housing shell between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge. The pusher member defines a longitudinal bore. The knife holder is supported within the longitudinal bore of the pusher member and has a distal portion that defines a first engagement portion. The knife holder is movable within the housing shell between a retracted position and an advanced position. The knife has a proximal portion and a distal portion. The distal portion defines a cutting edge. The proximal portion defines a second engagement portion that is coupled to the first engagement portion to detachably secure the knife to the knife holder. The knife can uncouple from the first engagement portion of the knife holder after a predetermined force is applied to the knife in a distal direction. The anvil assembly is movable relative to the staple cartridge between an open position and a clamped position and comprises a cutting ring formed of a material that can be penetrated by the knife. The knife is embedded in the cutting ring when the surgical stapling device is fired, and the knife is separated from the knife holder when the anvil assembly is moved from the clamped position to the open position after the surgical stapling device is fired.

[0015] Another aspect of this disclosure relates to a knife assembly comprising a knife holder and a knife. The knife holder has a distal portion that defines a first engagement portion. The knife has a proximal portion and a distal portion. The distal portion defines a cutting edge. The proximal portion defines a second engagement portion that is coupled to the first engagement portion to detachably secure the knife to the knife holder. The knife can uncouple from the first engagement portion of the knife holder after a predetermined force is applied to the knife.

[0016] The specifics of one or more aspects of the present disclosure are set forth in the accompanying drawings and description below. Other features, objects, and advantages of the technology described in this disclosure will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0017] Various aspects and features of the present disclosure are described with reference to the drawings, in which like reference numerals designate like or corresponding elements in the several views, and:

[0018] Figure 1 is a side perspective view of a surgical stapling device comprising a tool assembly having a reload assembly in accordance with aspects of the present disclosure;

[0019] Figure 2 is Figure 1 is an enlarged view of a distal portion of the surgical stapling device shown in FIG. 1 with the anvil assembly removed;

[0020] Figure 3 is a side perspective exploded view of a reload assembly of a surgical stapling device of Figure 1

[0021] Figure 4 is a magnified view of a designated detail area shown in Figure 3

[0022] Figure 5 is a side perspective view of a cartridge and annular knife of a surgical stapling device shown in Figure 3

[0023] Figure 6 is a cross-sectional view of the annular knife separated from the cartridge taken along section line 6-6 of Figure 4

[0024] Figure 7 is a cross-sectional view through the distal portions of the cartridge and annular knife as the annular knife is moved into engagement with the cartridge;

[0025] Figure 8 is a cross-sectional view through the distal portions of the cartridge and annular knife with the annular knife in engagement with the cartridge;

[0026] Figure 9 is a cross-sectional view through the distal portions of the cartridge and annular knife with the annular knife in engagement with the cartridge;

[0027] Figure 10 is a cross-sectional view taken along section line 10-10 of Figure 2

[0028] Figure 11 is a cross-sectional view taken along section line 11-11 of Figure 2

[0029] Figure 12 is a cross-sectional view taken along section line 11-11 of Figure 2

[0030] Figure 13 is a cross-sectional view taken along section line 11-11 of Figure 2

[0031] Figure 14 is a cross-sectional view taken along section line 11-11 of Figure 1 ​​​​​​​​a cross-sectional view of a distal portion of the surgical stapling device shown with the surgical stapling device in a fired, undamped position, the anvil assembly in an inclined position, and the annular knife separated from the knife carriage; and

[0032] Figure 15 is Figure 14 a side perspective view of a distal portion of the surgical stapling device shown with the surgical stapling device in an undamped, fired position and the annular knife separated from the knife carriage. DETAILED DESCRIPTION

[0033] Various aspects of the disclosed surgical stapling device including a reload assembly comprising the present disclosure will now be described in detail with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout several views. It is understood that the disclosed aspects are only examples of the disclosure and can be embodied in various forms. Well-known functions or structures have not been described in detail to avoid obscuring the present disclosure. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Furthermore, directional terms as used herein— for example up, down, right, left, front, back, top, bottom, over, under, upper, lower, inner, outer, clockwise, and counterclockwise— are used to facilitate describing the illustrated embodiments and are not intended to limit the scope of the disclosure. It is to be understood that these and other terms are not intended to limit the scope of the disclosure.

[0034] In this description, the term "proximal" is used to refer generally to the portion of the device closer to the clinician, while the term "distal" is used to refer generally to the portion of the device further from the clinician. Additionally, the term "clinician" is used to refer generally to medical personnel, including doctors, nurses, and support staff.

[0035] The present disclosure relates to a circular surgical stapling device including a reload assembly having a knife carriage that is detachably coupled to a knife having a cutting edge and can be separated from the knife carriage after a predetermined force is applied to the knife. The knife is positioned to engage and penetrate a cutting ring assembly on an anvil assembly of the stapling device when the stapling device is fired. The engagement of the knife with the cutting ring assembly is sufficient to separate the knife from the knife carriage when the knife carriage returns to a retracted position after the stapling device has been fired. When the knife is separated from the knife carriage, the cutting edge of the knife is embedded in the cutting ring assembly to avoid exposing the cutting edge of the knife to the clinician.

[0036] Figure 1The description includes a circular stitching device 10, typically shown as a reloading assembly 100, according to various aspects of this disclosure. The circular stitching device 10 includes a handle or actuator assembly 12, an elongated body or adapter assembly 14, a reloading assembly 100, and an anvil assembly 18, which is supported relative to the reloading assembly 100 in an unclamped position and a clamped position. Figure 10 The reloading assembly 100 moves between the reloading assembly 100 and the anvil assembly 18. In various aspects of this disclosure, the reloading assembly 100 includes a proximal portion 102 detachably coupled to the distal portion of the adapter assembly 14, and the adapter assembly 14 includes a proximal portion detachably coupled to the handle assembly 12. Alternatively, it is conceivable that the reloading assembly 100 can be securely fixed to the adapter assembly 14 and / or the adapter assembly can be securely fixed to the handle assembly 12. The handle assembly 12 includes a body 22 that defines a fixed handle 22a supporting an actuation button 24 for operating various functions of the circular suture device 10, including approaching the reloading assembly 100 and the anvil assembly 18, firing a pin from the reloading assembly 100, and cutting or coring tissue, as described in further detail below.

[0037] The circular suture device 10 is described as an electrically powered suture device including an electrically powered handle assembly 12, which may support one or more batteries (not shown). An adapter assembly 14 transfers power from the handle assembly 12 to the reloading assembly 100 and the anvil assembly 18, respectively, for suturing and cutting tissue. Examples of electrically powered suture devices can be found in U.S. Patents Nos. 9,055,943 and 9,023,014, and U.S. Publications Nos. 2018 / 0125495 and 2017 / 0340351. Alternatively, it is conceivable that aspects of the reloading assembly 100 disclosed herein may also be incorporated into, for example, a manually powered suture device disclosed in U.S. Patent No. 7,303,106 ('106 patent) or a suture device disclosed, for example, in U.S. Patent No. 9,962,159, configured for use with a robotic system and not including a handle assembly.

[0038] Figure 2 and 3 The reloading assembly 100 includes a housing 110, a nail actuator 112, a nail pusher 112a, a blade holder 114, an annular blade 116 supported on the blade holder 114, a nail magazine 118, and a plurality of nails 120 supported within the nail magazine 118. The housing 110 includes an outer housing portion 121 and an inner housing portion 122 spaced apart from each other to define an annular cavity 124. The nail actuator 112 and the nail pusher 112a are movable from a retracted position to an advanced position within the annular cavity 124 of the housing 110 to eject the nails 120 from the nail magazine 118.

[0039] The staple cartridge 118 is annular and defines an annular row of staple recesses 126. Each staple recess 126 supports one of the staples 120. The staple actuator 112 and the staple pusher 112a define a longitudinal through-hole 128 for receiving the tool holder 114. Figure 10 The nail actuator 112 has a distal portion adjacent to the proximal portion of the nail pusher member 112a, such that distal movement of the nail actuator 112 within the housing 110 causes distal movement of the nail pusher member 112a within the housing 110. The nail pusher member 112a of the reloading assembly 100 has a plurality of fingers 130 ( Figure 3 Each of the plurality of fingers 130 is housed in a corresponding recess in the nail recess 126 of the nail cartridge 118 and is movable through the corresponding nail recess 126 to move the pusher member 112a from the retracted position within the housing 110. Figure 10 Move to the propulsion position. Figure 11 When the nail 120 pops out from the nail recess 126, the nail 120 will be ejected.

[0040] The tool holder 114 is housed within the longitudinal through-hole 128 of the nail actuator 112 and includes a distal portion 140 and a plurality of spaced, longitudinally extending proximal portions 142. Figure 3 The distal portion 140 and the proximal portion 142 define the inner housing portion 122 for receiving the outer housing 110. Figure 3 The stepped center hole allows the tool holder 114 to be in the retracted position around the inner housing portion 122 of the outer housing 110 within the nail actuator 112. Figure 10 ) and propulsion position ( Figure 11 The tool holder 114 moves between the two sides. The proximal portion 142 of the tool holder 114 defines a slot 148 that receives a guide portion 110a of the housing 110 to limit the tool holder 114 to longitudinal movement within the housing 110.

[0041] The housing 110 includes a support connection mechanism 160. Figure 3 The proximal portion 158 of the ) is connected by a coupling mechanism that detachably connects the reloading assembly 100 to the suture device 10. Figure 1 The adapter assembly 14 facilitates the replacement of the reloading assembly 100 and the reuse of the stitching device 10. The coupling mechanism 160 includes a retaining member 162 and a coupling member 164. The retaining member 162 secures the coupling member 164 around the proximal portion 158 of the housing 110. The coupling member 164 is housed around the proximal portion 158 of the housing 110 and is attached to the distal portion 14a of the adapter assembly 14. Figure 1 The adapter assembly 14 is engaged to connect to the reloading assembly 100. It is conceivable that other coupling mechanisms could be used to secure the reloading assembly 100 to the adapter 14.

[0042] Figures 4 to 6 A distal portion 140 of the knife carriage 114 and the annular knife 116 of the reload assembly 100 are illustrated. The distal portion 140 of the knife carriage 114 is generally cylindrical and includes a reduced diameter region 170. In aspects of the disclosure, the reduced diameter region 170 is defined in part by a plurality of resilient fingers or detents 172. Each of the plurality of resilient fingers 172 includes an engagement portion 174 that detachably engages the annular knife 116 to secure the annular knife 116 to the knife carriage 114. In certain aspects of the disclosure, the engagement portion 174 of each of the resilient fingers 172 defines an outwardly facing concave surface 174a, such that the reduced diameter region 170 on the distal portion 140 of the knife carriage 114 defines an annular recess.

[0043] The annular knife 116 includes a body 180 having an annular cutting edge 182 at a distal end thereof and an engagement portion 184 on a proximal end portion thereof. In aspects of the disclosure, the engagement portion 184 on the proximal end of the annular knife 116 includes an annular or generally annular protruding portion 186 Figure 6 that is received within the annular recess defined by the engagement portion 174 of the resilient fingers 172 to detachably secure the annular knife 116 to the distal portion 140 of the knife carriage 114. In certain aspects of the disclosure, the engagement portion 184 on the proximal end portion of the annular knife 116 is formed by crimping or inverting the proximal end portion of the annular knife 116 in on itself.

[0044] Figures 7 to 9 The annular knife 116 is illustrated when coupled to the distal portion 140 of the knife carriage 114. To couple the annular knife 116 to the knife carriage 114, the proximal end portion of the annular knife 116 is aligned with the distal portion 140 of the knife carriage 114 and the annular knife 116 is moved toward the knife carriage 114 in the direction indicated by arrow “A” in Figure 7 When the engagement portion 184 on the proximal end portion of the annular knife 116 engages the resilient fingers 172 on the distal portion 184 of the knife carriage 114, the resilient fingers 172 deform inwardly in the direction indicated by arrow “B” in Figure 7 to allow the engagement portion 184 on the proximal end of the annular knife 116 to pass over the resilient fingers 172 and into the annular recess defined by the concave surface 174a of the resilient fingers 172. When the engagement portion 184 of the annular knife 116 passes over the resilient fingers 172 and into the annular recess defined by the resilient fingers 172, the resilient fingers 172 deform outwardly in the direction indicated by arrow “C” in Figure 8The arrow "C" returns to its undeformed position to hold the ring cutter 116 on the distal portion of the tool holder 114. The ring cutter 116 will remain on the distal portion of the tool holder 114 until a predetermined force is applied to the ring cutter 116, sufficient to separate the engaging portion 184 on the proximal end of the ring cutter 116 from the annular recess defined by the concave surface 174a of the resilient finger 172. The predetermined force can be set to a desired level by selecting the material for forming the finger 172 of the tool holder 114 with suitable elasticity and / or thickness.

[0045] It is conceivable that the engagement portion of the tool holder 114 and the ring cutter 116 may have a variety of different configurations, not shown here, for detachably connecting the ring cutter 116 to the tool holder 114. It is also conceivable that the engagement portion of the ring cutter 116 and the tool holder 114 may be configured as an interlocking device via friction and / or breakage operation.

[0046] Figure 10 The reloading assembly 100 and anvil assembly 18 of the suture device 10 are described in the clamped, unfired position, with the staple actuator 112, staple pusher 112a, blade holder 114, and annular blade 116 in their retracted positions, and the anvil assembly 18 aligned side-by-side with the staple cartridge 118. In this position, the annular cutting edge 182 is recessed into the staple cartridge 118.

[0047] As described, the anvil assembly 18 includes an anvil head 30 pivotally supported on a central rod 32. The anvil head 30 can be positioned on the central rod 32 from an operating position ( Figure 10 Pivot to a tilted or reduced profile position. Figure 14 For a description of an exemplary aspect of the operation of an anvil assembly including a tiltable anvil head, see patent '106. The anvil head 30 supports a cutting ring assembly 40, which includes a cutting ring 42 aligned with the cutting edge 182 of the blade 116. The cutting ring 42 is formed when the suture device 10 ( Figure 1 When the blade 116 is propelled into the cutting ring 42 upon firing, material that can be penetrated by the cutting edge 182 of the blade 116 is formed.

[0048] Figure 11The reload assembly 100 and the anvil assembly 18 of the stapling device 10 in the clamped and fired position are illustrated. In this position, the staple actuator 112 and the pusher member 112a have been moved in the direction indicated by arrow "D" to the advanced position to eject the staples 120 from the staple cartridge 118 into the anvil head 30. In addition, the knife carriage 114 and the annular knife 116 coupled to the distal portion 140 of the knife carriage 114 have been moved in the direction of arrow "E" to its advanced position to advance the cutting edge 182 of the annular knife 116 into the cutting ring 42 of the anvil assembly 18. In this position, the distal portion of the annular knife 116 is embedded in the cutting ring 42 of the anvil assembly 18.

[0049] Figure 12 and 13 The reload assembly 100 and the anvil assembly 18 of the stapling device 10 in the fired position are illustrated as the anvil assembly 18 moves from the clamped position in which the anvil head 30 is in juxtaposed alignment with the staple cartridge 118 to the open position in which the anvil head 30 is spaced apart from the staple cartridge 118. In this position, the anvil assembly 18 is moved away from the knife carriage 114 in the direction of arrow "F". Since the annular knife 116 is embedded in the cutting ring 42 of the anvil head 30, movement of the anvil head 30 in the direction of arrow "F" will cause the knife carriage 114 to move in the direction of arrow "G" as Figure 12 indicated. Further distal movement of the anvil head 30 relative to the knife carriage 114 in the direction of arrow "H" in Figure 13 will cause the engagement portion 184 on the proximal portion of the annular knife 116 to exert a force on the resilient fingers 172 on the distal end of the knife carriage 114 to cause the annular knife 116 to separate from the knife carriage 114. The cutting edge 182 of the annular knife 116 will remain embedded in the cutting ring 42 of the cutting ring assembly 40 in the anvil head 30 of the anvil assembly 18 to safely protect the clinician from the cutting edge 182 of the annular knife 116.

[0050] Figure 14 and 15 The reload assembly 100 and the anvil assembly 18 of the stapling device 10 are illustrated with the anvil head 30 of the anvil assembly 18 in the tilted position and the annular knife 116 embedded in the cutting ring 42 of the cutting ring assembly 40 of the anvil assembly 18. The anvil head 30 is urged to the tilted position by the biasing mechanism 50 supported within the central rod 32 of the anvil assembly 18. For a detailed description of exemplary aspects of the biasing mechanism 50, see, for example, the '106 patent.

[0051] Those skilled in the art will appreciate that the apparatus and methods specifically described herein are non-limiting example embodiments. It is contemplated that elements and features of one example embodiment can be combined with elements and features of another without departing from the scope of the present disclosure. Likewise, other features and advantages of the present disclosure will be appreciated based on the above-described embodiments. Accordingly, the present disclosure is not to be limited as by the appended claims to the specific examples described herein.

Claims

1. A reload assembly comprising: a housing shell defining a cavity and having a proximal portion and a distal portion; a staple cartridge supported on the distal portion of the housing shell, the staple cartridge supporting a plurality of staples; a pusher member movable within the housing shell between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge, the pusher member defining a longitudinal bore; a knife holder supported within the longitudinal bore of the pusher member, the knife holder having a distal portion defining a first engagement portion, the first engagement portion defined by a plurality of resilient fingers formed on the distal portion of the knife holder, each of the plurality of resilient fingers defining a concave surface to define an annular recess about the distal portion of the knife holder, the knife holder movable within the housing shell between a retracted position and an advanced position; and a knife having a proximal portion and a distal portion, the proximal portion defining a second engagement portion coupled to the first engagement portion to detachably secure the knife to the knife holder, wherein upon application of a predetermined force to the knife in a distal direction, the knife is decouplable from the first engagement portion of the knife holder, wherein the second engagement portion formed on the proximal portion of the knife includes an annular ledge received within the annular recess defined by the plurality of resilient fingers of the knife holder to detachably secure the knife to the knife holder, the second engagement portion formed on the proximal portion of the knife by inverting the proximal portion of the knife.

2. The reload assembly of Claim 1, wherein the knife is annular.

3. A stapling device comprising: an adapter assembly having a distal end portion; a reload assembly secured to the distal end portion of the adapter assembly, the reload assembly including: a housing shell defining a cavity and having a proximal portion and a distal portion; a staple cartridge supported on the distal portion of the housing shell, the staple cartridge supporting a plurality of staples; a pusher member movable within the housing shell between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge, the pusher member defining a longitudinal bore; a knife holder supported within the longitudinal bore of the pusher member, the knife holder having a distal portion defining a first engagement portion, the first engagement portion defined by a plurality of resilient fingers formed on the distal portion of the knife holder, each of the plurality of resilient fingers defining a concave surface to define an annular recess about the distal portion of the knife holder, the knife holder movable within the housing shell between a retracted position and an advanced position; and a knife having a proximal portion and a distal portion, the distal portion defining a cutting edge, the proximal portion defining a second engagement portion coupled to the first engagement portion to detachably secure the knife to the knife holder, wherein upon application of a predetermined force to the knife in a distal direction, the knife is decouplable from the first engagement portion of the knife holder; and an anvil assembly movable relative to the cartridge between an open position and a clamped position, the anvil assembly including a cutting loop formed of a material that can be penetrated by the knife, wherein the knife is embedded in the cutting loop when the stapling device is fired and the knife is separated from the knife holder after the stapling device is fired when the anvil assembly is moved from the clamped position to the open position, wherein the second engagement portion formed on the proximal portion of the knife includes an annular protrusion portion that is received within the annular recess defined by the plurality of resilient fingers of the knife holder to removably secure the knife to the knife holder, the second engagement portion formed on the proximal portion of the knife by inverting the proximal portion of the knife.

4. The stapling device of claim 3, wherein the knife is annular.

5. The stapling device of claim 3, wherein the anvil assembly includes an anvil head and a central rod, the anvil head pivotably coupled to the central rod and movable from an operational position to a tilted position.

6. A knife assembly comprising: a knife holder having a distal portion defining a first engagement portion, the first engagement portion defined by a plurality of resilient fingers formed on the distal portion of the knife holder, each of the plurality of resilient fingers defining a concave surface to define an annular recess about the distal portion of the knife holder; and a knife having a proximal portion and a distal portion, the distal portion defining a cutting edge, the proximal portion defining a second engagement portion coupled to the first engagement portion to removably secure the knife to the knife holder, wherein the knife can be uncoupled from the first engagement portion of the knife holder after a predetermined force is applied to the knife, wherein the second engagement portion formed on the proximal portion of the knife includes an annular protrusion portion that is received within the annular recess defined by the plurality of resilient fingers of the knife holder to removably secure the knife to the knife holder, the second engagement portion formed on the proximal portion of the knife by inverting the proximal portion of the knife.

7. The knife assembly of claim 6, wherein the knife is annular.

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