Reloading assembly with toolholder lock

Abstract

This invention relates to a reloading assembly with a scalpel holder locking mechanism. A surgical suturing device includes a reloading assembly comprising at least one locking tab to hold the scalpel holder of the reloading assembly in a retracted position after the suturing device is fired. The at least one locking tab is disposed on the scalpel holder and configured to engage with a stop surface of a staple actuator to prevent the scalpel holder from advancing further relative to the staple actuator.

Description

Technical Field

[0001] This disclosure relates to a circular suturing device, and more particularly, to a reloading assembly for a circular suturing device having a structure for holding the blade holder of the reloading assembly in a retracted position after the suturing device is fired. Background Technology

[0002] A typical circular suturing device comprises an elongated body and a housing or reloading assembly supported on a distal portion of the elongated body. The reloading assembly includes the housing, a staple cartridge with multiple staples supported on the housing, a pusher assembly, a blade defining a cylindrical cavity, and a blade holder supporting the blade. The pusher assembly includes a ring pusher and a staple pushing member, which engages with the ring pusher and is movable to move the staple pushing member to eject staples from the staple cartridge. The blade holder is movable to advance the blade through the staple cartridge for core extraction or tissue cutting.

[0003] After the suturing device has been operated to suture and cut the tissue, the scalpel holder and scalpel are retracted to withdraw the scalpel into the housing. This serves two purposes. The first is to move the scalpel to a position that allows for the removal of a tissue ring from the cavity defined by the scalpel. The second is to position the scalpel in a recessed position within the housing to prevent injury to the clinician during manipulation and placement of the reloading assembly.

[0004] In some cases, tissue rings are compressed to such an extent within the cavity defined by the blade that they become difficult to remove from the cavity. There has been a need in the art for a reloading assembly that includes an improved structure for holding the blade / blade holder in the retracted position. Summary of the Invention

[0005] A surgical suturing device includes: an adapter assembly having a proximal end portion and a distal end portion; and a reloading assembly supported on the distal end portion of the adapter assembly. The reloading assembly includes a housing and a staple cartridge supporting a plurality of staples, the staple cartridge being supported on the housing. The housing includes an outer shell portion and an inner shell portion. The inner shell portion and the outer shell portion define an annular cavity therebetween. A staple pusher is supported within the annular cavity of the housing and is movable from a retracted position to an advanced position to eject staples from the staple cartridge. A staple actuator is supported within the annular cavity of the housing and has a stop surface. The staple actuator is positioned to engage the staple pusher and is movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position. The staple actuator and the staple pusher define a through-hole. A scalpel holder is supported within the through-hole and is movable between a retracted position and an advanced position. The scalpel holder defines a longitudinal axis and includes at least one locking tab. When the staple actuator is in its forward position and the cutter holder is in its retracted position to prevent further forward movement, the at least one locking tab is positioned proximal to the stop surface on the staple actuator. The cutter is supported on the cutter holder.

[0006] In various embodiments, the surgical suturing device further includes a handle assembly, on which the proximal end portion of the adapter assembly is supported. When the staple actuator and the scalpel holder are in their retracted position, the at least one locking tab of the scalpel holder can be positioned distal to the stop surface of the staple actuator.

[0007] In some embodiments, the cutter holder includes at least one hook member. The at least one hook member can be aligned with the stop surface of the stitching actuator such that the stitching actuator holds the cutter holder within the housing. The at least one hook member can be aligned with the stop surface of the stitching actuator to prevent the cutter holder from advancing before the stitching actuator advances. The at least one locking tab can be disposed on the at least one hook member distal to the proximal end.

[0008] In various embodiments, the at least one locking tab includes an angled surface and the pin actuator may include an angled inner surface. Engagement of the angled surface of the at least one locking tab with the angled inner surface of the pin actuator causes the at least one hook member to deflect radially inward. Engagement of the stop surface with the locking surface prevents the tool holder from advancing.

[0009] In some embodiments, the surgical suture device includes a coupling mechanism configured to connect the reloading component to an adapter component to facilitate release of the reloading component from the adapter component.

[0010] A reloading assembly for a surgical suture device includes: a housing; and a staple cartridge supporting a plurality of staples, the staple cartridge being supported on the housing. The housing includes an outer shell portion and an inner shell portion. The inner shell portion and the outer shell portion define an annular cavity therebetween. A staple pusher is supported within the annular cavity of the housing and is movable from a retracted position to an advanced position to eject staples from the staple cartridge. A staple actuator is supported within the annular cavity of the housing and has a stop surface. The staple actuator is positioned to engage the staple pusher and is movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position. The staple actuator and the staple pusher define a through-hole. The tool holder is supported within the through-hole and is movable between a retracted position and an advanced position. The tool holder defines a longitudinal axis and includes at least one locking tab. When the stitching actuator is in its retracted position to allow the tool holder to advance, the at least one locking tab is positioned distal to the stop surface on the stitching actuator. When the stitching actuator is in its advanced position and the tool holder is in its retracted position to prevent further advancement of the tool holder, the at least one locking tab is positioned proximal to the stop surface on the stitching actuator. The tool is supported on the tool holder.

[0011] In various embodiments, the cutter holder includes at least one hook member. The at least one hook member can be aligned with the stop surface of the stitching actuator, such that the stitching actuator holds the cutter holder within the housing. The at least one hook member can be aligned with the stop surface of the stitching actuator to prevent the cutter holder from advancing before the stitching actuator advances. The at least one locking tab can be disposed on the at least one hook member distal to the proximal end.

[0012] In various embodiments, the at least one locking tab includes an angled surface and the pin actuator includes an angled inner surface. Engagement of the angled surface of the at least one locking tab with the angled inner surface of the pin actuator causes the at least one hook member to deflect radially inward. The at least one locking tab may include a locking surface. Engagement of the stop surface with the locking surface prevents the tool holder from advancing.

[0013] In some embodiments, the reloading component includes a coupling mechanism configured to couple the reloading component to an adapter assembly of the surgical suture device to facilitate release of the reloading component from the adapter assembly. Attached Figure Description

[0014] Various embodiments of the reloading assembly for a surgical suture device disclosed herein are described below with reference to the accompanying drawings, in which:

[0015] Figure 1 This is a side perspective view of a surgical suturing device including an exemplary embodiment of the disclosed reloading component, wherein the suturing device is in a clamping position;

[0016] Figure 2 yes Figure 1 The exploded side perspective view of the reloaded component shown;

[0017] Figure 3 From Figure 2 Side perspective view of the distal end of the tool holder of the reloading assembly shown;

[0018] Figure 4 From Figure 2 Side perspective view of the proximal end of the stitch actuator of the reloading assembly shown;

[0019] Figure 5 yes Figure 2 The cross-sectional view shown is of the reload assembly in the pre-firing state.

[0020] Figure 6 yes Figure 2 The cross-sectional view of the reloading assembly is shown, with the pin actuator of the reloading assembly in a partially advanced position.

[0021] Figure 7 yes Figure 2 The cross-sectional view of the reloading assembly is shown, with the tool holder of the reloading assembly in a partially forward position.

[0022] Figure 8 yes Figure 2 The cross-sectional view of the reloading assembly is shown, with the stud actuator of the reloading assembly in the forward position;

[0023] Figure 9 yes Figure 2 The cross-sectional view shown is of the reloading assembly with the tool holder in the forward position.

[0024] Figure 10 yes Figure 2 The cross-sectional view of the reload is shown, with the tool holder of the reload assembly in a partially retracted position;

[0025] Figure 11 yes Figure 2 The cross-sectional view shown is of the reloaded assembly with the tool holder in the retracted position.

[0026] Figure 12 From Figure 2 The diagram shows a perspective view of the proximal end of the reloading assembly, with the housing assembly shown in dashed lines and the tool holder in the retracted position; and

[0027] Figure 13 yes Figure 12 The enlarged view showing the detailed area is shown. Detailed Implementation

[0028] The disclosed reloading assembly for a surgical suture device will now be described in detail with reference to the accompanying drawings, wherein in each of the several views, the same reference numerals denote the same or corresponding elements. However, it should be understood that the disclosed embodiments are merely examples of this disclosure and can be implemented in various forms. To avoid unnecessarily obscuring this disclosure, well-known functions or constructions have not been described in detail. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather serve only as the basis for the claims and as a representative basis for teaching those skilled in the art to adopt this disclosure differently in virtually any suitable detailed construction. Furthermore, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to aid understanding of the description and are not intended to limit this disclosure.

[0029] In this description, the term "proximal" is generally used to refer to the part of the device closer to the clinician, while the term "distal" is generally used to refer to the part of the device farther from the clinician. Furthermore, the term "clinician" is generally used to refer to medical personnel, including doctors, nurses, and support staff.

[0030] Figure 1A circular suture device 10 is shown, comprising an exemplary embodiment of a reloading assembly generally shown as a reloading assembly 100. The suture device 10 includes a handle assembly 12, an elongated body or adapter assembly 14, a reloading assembly 100, and an anvil assembly 18 supported for movement relative to the reloading assembly 100 between a spaced-out position and a proximal position, as is known in the art. In various embodiments, the reloading assembly 100 includes a proximal portion 102 releasably coupled to a distal portion 14a of the adapter assembly 14. In some embodiments, the handle assembly 12 includes a fixed handle 22 supporting an actuation button 24 for controlling various functions of the suture device 10, including approaching the reloading assembly 100 and the anvil assembly 18 respectively, firing staples from the reloading assembly 100, and cutting or core-taking tissue.

[0031] The suturing device 10 is shown as an electric suturing device, comprising an electric handle assembly 12 capable of supporting one or more batteries (not shown). An adapter assembly 14 is in the form of an adapter assembly that transmits power from the handle assembly 12 to the reloading assembly 100 and the anvil assembly 18, respectively. Examples of electric suturing devices can be found in U.S. Patent Nos. 9,055,943, 9,023,014, and U.S. Publications 2018 / 0125495 and 2017 / 0340351. Alternatively, it is envisioned that the reloading assembly may also be incorporated into a manual suturing device as disclosed in U.S. Patent No. 7,303,106 ('106 patent), or a suturing device configured for use with a robotic system and not comprising a handle assembly as disclosed in U.S. Patent No. 9,962,159.

[0032] Figure 2 A reloading assembly 100 is shown, comprising a housing 110, a staple actuator 112, a staple pushing member 112a, a blade holder 114, an annular blade 116 supported on the blade holder 114, a staple cartridge 118, and a plurality of staples 120 supported within the staple cartridge 118. The staple cartridge 118 is annular and defines an annular row of staple recesses 124. Each of the staple recesses 124 supports one of the plurality of staples 120. The staple actuator 112 and the staple pushing member 112a together define a longitudinal through-hole 132. Figure 8The staple actuator 112 has a distal portion that abuts against a proximal portion of the staple pusher member 112a, such that distal movement of the staple actuator 112 within the housing 110 causes distal movement of the staple pusher member 112a within the housing 110. The staple pusher member 112a of the reloading assembly 100 has a plurality of fingers 134. Each of the plurality of fingers 134 is received within a corresponding staple recess 124 of the staple cartridge 118 and is movable through the corresponding staple recess 124 to eject a staple 120 from the staple recess 124 when the staple pusher member 112a moves from a retracted position to an advanced position within the housing 110.

[0033] The outer housing 110 includes an outer housing portion 140 and an inner housing portion 142, which are spaced apart from each other to define an annular cavity 144 between the outer housing portion 140 and the inner housing portion 142. The staple actuator 112 and the staple pushing member 112a can move from a retracted position to an advanced position within the annular cavity 144 of the outer housing 110 to eject the staple 120 from the staple cartridge 118.

[0034] An annular blade 116 is supported around the outer surface of the blade holder 114, defining a cylindrical cavity 117 and including a distal cutting edge 117a. In various embodiments, the annular blade 116 includes an inwardly extending shank 117b that is received within a recess 114a defined in the outer surface of the blade holder 114 to secure the annular blade 116 to the blade holder 114. The blade holder 114 and the annular blade 116 are positioned within a through-hole 132 of the staple actuator 112 and are movable from a retracted position to an advanced position to cut tissue radially inwardly positioned from the staple cartridge 118.

[0035] The inner housing portion 142 of the outer housing 110 defines a through hole 150. Figure 3 ), which receives the anvil shaft (not shown) of the anvil assembly 18. For a more detailed description of the exemplary anvil assembly 18, see, for example, patent '106. The through hole 150 has a receiving bushing 152 ( Figure 5 The bushing 152 defines a through-hole 150a in the proximal portion of the inner housing portion 142. The through-hole 150a is coaxial and forms an extension of the through-hole 150 forming the inner housing portion 142. In various embodiments, the bushing 152 is formed of a high-strength material, such as metal, to provide additional strength to the inner housing portion 142 of the outer housing 110, and includes an annular flange 152a.

[0036] The housing 110 includes a proximal portion 158 supporting a coupling mechanism 160, which is operable to releasably couple the reloading assembly 100 to the suture device 10. Figure 1The adapter assembly 14. The coupling mechanism 160 allows for the removal and replacement of the reloading assembly 100 to facilitate the reuse of the suture device 10. In various embodiments, the coupling mechanism 160 includes a retaining member 162 and a coupling member 164. The coupling member 164 is received around the proximal portion 158 of the housing 110 and is configured to engage with the distal portion 14a of the adapter assembly 14. Figure 1 The reloading component 100 is engaged to connect to the adapter component 14. Alternatively, other coupling mechanisms may be used to secure the reloading component 100 to the adapter component 14.

[0037] Reload component 100 may include EPROM holder 170. Figure 3 The EPROM (not shown) is supported on the housing 110 and configured to support the EPROM assembly 10. As is known in the art, the EPROM can communicate with the adapter assembly 14 to provide information to the adapter assembly 14 and the handle assembly 12 about the characteristics of the reloading assembly 10. In some embodiments, the EPROM holder 70 may define a cylindrical sleeve housed around the distal portion of the bushing 52.

[0038] Figure 3 A tool holder 114 is shown, comprising a plurality of spaced-apart resilient longitudinal body portions 173 that are spaced apart from each other and together define a central bore 172. The central bore 172 of the tool holder 114 receives an inner housing portion 142 of the outer housing 110, such that the tool holder 114 can be in a retracted position around the inner housing portion 142 of the outer housing 110. Figure 5 ) and forward position ( Figure 9 The tool holder 114 moves between the longitudinal body portion 173, which defines a slot 176 that receives a guide portion (not shown) of the housing 110 to restrict the tool holder 114 to move longitudinally within the housing 110.

[0039] In various embodiments, the knife holder 114 includes a hook member 178 positioned to engage with the staple actuator 112 to move the staple actuator 112 from its retracted position to its forward position. The hook member 178 is located in the annular cavity 144 of the housing 110. Figure 2 The hook members 178 extend radially outward from the cutter holder 114 toward the staple actuator 112. Each of the hook members 178 includes an engagement surface 178a and supports a locking tab 180. The locking tab 180 is positioned distal to the engagement surface 178a of the hook member 178 and extends radially outward from the cutter holder 114 toward the staple actuator 112. Each of the locking tabs 180 includes an angled surface 180a facing proximal and a locking surface 180b facing distal.

[0040] Figure 4 A stud actuator 112 comprising a body 182 is shown, the body 182 also being housed within the inner housing portion 142 of the outer housing 110. Figure 3 Around, and in response to the tool holder 114 moving from its retracted position to its forward position, it can move from the retracted position ( Figure 5 Move to the forward position ( Figure 9 The body 182 defines a plurality of guide slots 182a and at least one stop surface 184. In some embodiments, at least one stop surface 184 is positioned at the distal end of a channel 186 formed in the body 182. The channel 186 is positioned and sized to receive a hook member 178. The guide slots 182a of the staple actuator 112 receive a guide member (not shown) of the housing 110 to restrict the staple actuator 112 to longitudinal movement within the housing 110. At least one stop surface 184 of the staple actuator 112 is associated with the hook member 178 of the tool holder 114. Figure 3 The engagement surfaces 178a of the hook member 178 of the stapler 112 are longitudinally aligned such that the advancement of the stapler 114 within the through-hole 132 of the stapler 112 causes the engagement surface 178a of the hook member 178 of the stapler 112 to engage with at least one stop surface 184 of the stapler 112. In this manner, the engagement of the engagement surface 178a of the hook member 178 with the stop surface 184 of the stapler 112 prior to the advancement of the stapler 112 prevents the stapler 114 from advancing. Alternatively, the stapler 112 and the stapler 114 can be configured such that the advancement of the stapler 114 causes the stapler 112 to advance within the housing 110 to its advanced position to complete the staple forming process.

[0041] Figure 5 The reloading assembly 100 in a pre-firing state is shown, wherein the reloading assembly 100 ( Figure 3 The blade holder 114 and the pin actuator 112 are in the retracted position. When the blade holder 114 and the pin actuator 112 are in the pre-firing retracted position, the engagement surface 178a of each of the hook members 178 is aligned with and slightly spaced from the proximal side of the corresponding stop surface 184 of the pin actuator 112, and each of the locking tabs 180 is positioned distal to the corresponding stop surface 184.

[0042] Figure 6The reloading assembly 100 is shown when the staple actuator 112 is moved to a partially advanced position independently of the tool holder 114. As the staple actuator 112 moves distally within the housing 110, the staple pusher member 112a moves distally in the direction indicated by arrow "A" to advance a plurality of fingers 134 of the staple pusher member 112a into the staple recess 124 of the staple cartridge 118 to partially eject the staples 120 from the staple cartridge 118 into the anvil assembly 18. In the partially advanced position, the stop surface 184 is positioned proximal to the locking tab 180, and the engagement surface 178a of the hook member 178 is spaced proximal to the stop surface 184 of the staple actuator 112.

[0043] Figure 7 The reloading assembly 100 is shown when the scalpel holder 114 moves to a partially advanced position independently of the staple actuator 112. To prevent the scalpel holder 114 from locking prematurely, and thus preventing it from moving to its advanced position to cut tissue, the scalpel holder 114 is reloaded by the suture device 10 after the staple actuator 112 has moved to its advanced position. Figure 1 ) tool holder driver 30 ( Figure 5 The tool holder 114 moves to a partially advanced position in the direction indicated by arrow "B". In this way, the locking tab 180 of the tool holder 114 moves to a position further away from the stop surface 184 of the stitch actuator 112, so as to allow the tool holder 114 and the attached annular cutter 116 to subsequently move to their advanced positions.

[0044] Figure 8 The reloading assembly 100 is shown when the staple actuator 112 moves independently of the tool holder 114 from its partially advanced position to its fully advanced position. As the staple actuator 112 moves distally within the housing 110, the staple pushing member 112a moves distally in the direction indicated by arrow "C" so that the plurality of fingers 134 of the staple pushing member 112a further advance through the staple recess 124 of the staple cartridge 118 to eject staples 120 from the staple cartridge 118 into the anvil assembly 18 to form staples 120 in tissue (not shown). In the fully advanced position, the stop surface 184 of the staple actuator 112 is positioned proximal to the locking tab 180 of the tool holder 114.

[0045] Figure 9The reloading assembly 100 is shown when the scalpel holder 114 moves independently of the staple actuator 112 to its fully forward position, with the staple actuator 112 in its fully forward position. As shown, the annular blade 116, attached to the scalpel holder 114, moves distally together with the scalpel holder 114 in the direction indicated by arrow "D" to cut tissue held between the anvil 18 and the staple cartridge 118. When both the staple actuator 112 and the scalpel holder 114 are in their fully forward positions, the engagement surface 178a of the hook member 178 is positioned proximal to the stop surface 184, and the stop surface 184 of the staple actuator 112 is spaced proximal to the locking tab 180 of the scalpel holder 114.

[0046] Although shown and described in separate actions, it is contemplated that the stitching actuator 112 and the stitching holder 114 can be moved simultaneously as long as the locking tab 180 of the tool holder 114 remains on the far side of the stop surface 184 of the stitching actuator 112.

[0047] Figure 10 and 11 The diagram illustrates the reloading assembly 100 after it has been fired, with the blade holder 114 moving independently of the staple actuator 114 from its forward position to its retracted position. As the blade holder 114 moves proximally toward its retracted position in the direction indicated by arrow "E", the annular blade 116 also moves proximally to a position concealed within the housing 110. In this position, the clinician is protected from accidental injury by the cutting edge 117a of the annular blade 116. As the blade holder 114 and the annular blade 116 move proximally within the housing 110, the staple actuator 112 remains in its forward position within the housing 110. As the blade holder 114 moves proximally relative to the staple actuator 112, the angled surface 180a of each of the locking tabs 180 engages with the angled inner surface 113 of the staple actuator 112, such that the hook member 178 is engaged by... Figure 10 The arrow "F" indicates the direction in which the pin actuator 112 deforms inward. In its deformed state, the locking tab 180 of the tool holder 114 passes inward and moves proximally beyond the corresponding stop surface 184 of the pin actuator 112. Figure 11 When the locking tab 180 moves proximally past the corresponding stop surface 184, the locking tab 180 is in contact with the stop surface 184. Figure 11 The arrow "G" indicates that the blade 112 bounces outward in its undeformed state until it reaches a position aligned with the corresponding stop surface 184. In this position, the locking tab 180 prevents the tool holder 112 from advancing further to retain the ring blade 116 within the housing 110 of the reloading assembly 100.

[0048] Figure 12 and 13The reloading assembly 100 in the post-firing state is shown. In the post-firing state, the staple actuator 112, the knife holder 114, and the ring cutter 116 are shown. Figure 11 The tool holder 114 is held in its retracted position by the stop surface 184. More specifically, the locking tab 180 of the tool holder 114 is positioned proximal to the stop surface 184 of the staple actuator 112 to prevent the tool holder 114 from advancing.

[0049] Those skilled in the art will understand that the apparatuses and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is contemplated that elements and features illustrated or described in connection with one exemplary embodiment may be combined with elements and features of another exemplary embodiment without departing from the scope of this disclosure. Similarly, those skilled in the art will understand other features and advantages of this disclosure based on the embodiments described above. Therefore, this disclosure is not limited to what has been specifically shown and described, except as indicated by the appended claims.

Claims

1. A surgical suturing device comprising: an adapter assembly having a proximal end portion and a distal end portion; and a reload assembly supported on the distal end portion of the adapter assembly, the reload assembly including: an outer shell housing including an outer housing portion and an inner housing portion, the inner housing portion and the outer housing portion defining an annular cavity therebetween; a staple cartridge supporting a plurality of staples, the staple cartridge supported on the outer shell housing; a staple pusher supported within the annular cavity and movable from a retracted position to an advanced position to eject a staple from the staple cartridge; a staple actuator supported within the annular cavity and having a stop surface, the staple actuator positioned in engagement with the staple pusher and movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position, the staple actuator and the staple pusher defining a through hole; a knife carriage supported within the through hole and movable between a retracted position and an advanced position, the knife carriage defining a longitudinal axis and including at least one locking tab positioned proximal to the stop surface on the staple actuator when the staple actuator is in its advanced position and the knife carriage is in its retracted position to prevent further advancement of the knife carriage; and a knife supported on the knife carriage, wherein the knife carriage includes at least one hook member aligned with the stop surface of the staple actuator to prevent advancement of the knife carriage before advancement of the staple actuator, wherein the at least one locking tab includes an angled surface and the staple actuator includes an angled inner surface, wherein engagement of the angled surface of the at least one locking tab with the angled inner surface of the staple actuator deflects the at least one hook member radially inward, wherein the at least one locking tab includes a locking surface, engagement of the stop surface with the locking surface prevents advancement of the knife carriage.

2. The surgical suturing device of claim 1, further including a handle assembly, the proximal end portion of the adapter assembly supported on the handle assembly.

3. The surgical suturing device of claim 1, wherein the at least one locking tab of the knife carriage is positioned distal to the stop surface of the staple actuator when the staple actuator and the knife carriage are in their retracted positions.

4. The surgical suturing device of claim 1, wherein the knife carriage includes at least one hook member aligned with the stop surface of the staple actuator such that the staple actuator maintains the knife carriage within the outer shell housing.

5. The surgical suturing device of claim 1, further including a coupling mechanism coupling the reload assembly to the adapter assembly to facilitate release of the reload assembly from the adapter assembly.

6. The surgical stapling device of claim 1, wherein the knife carriage includes at least one hook member having a proximal end, the at least one locking tab disposed on the at least one hook member distally of the proximal end.

7. A reload assembly for a surgical stapling device, the reload assembly comprising: a housing shell including an outer housing portion and an inner housing portion, the inner housing portion and the outer housing portion defining an annular cavity therebetween; a cartridge supporting a plurality of staples, the cartridge supported on the housing shell; a staple pusher supported within the annular cavity and movable from a retracted position to an advanced position to eject a staple from the cartridge; a staple actuator supported within the annular cavity and having a stop surface, the staple actuator positioned in engagement with the staple pusher and movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position, the staple actuator and the staple pusher defining a through hole; a knife carriage supported within the through hole and movable between a retracted position and an advanced position, the knife carriage defining a longitudinal axis and including at least one locking tab, the at least one locking tab positioned distally of the stop surface on the staple actuator when the staple actuator is in its retracted position to permit advancement of the knife carriage, and the at least one locking tab positioned proximally of the stop surface on the staple actuator when the staple actuator is in its advanced position and the knife carriage is in its retracted position to prevent further advancement of the knife carriage; and a knife supported on the knife carriage, wherein the knife carriage includes at least one hook member aligned with the stop surface of the staple actuator to prevent advancement of the knife carriage prior to advancement of the staple actuator, wherein the at least one locking tab includes an angled surface and the staple actuator includes an angled inner surface, wherein engagement of the angled surface of the at least one locking tab with the angled inner surface of the staple actuator deflects the at least one hook member radially inwardly, wherein the at least one locking tab includes a locking surface, engagement of the stop surface with the locking surface prevents advancement of the knife carriage.

8. The reload assembly of claim 7, wherein the knife carriage includes at least one hook member aligned with the stop surface of the staple actuator such that the staple actuator maintains the knife carriage within the housing shell.

9. The reload assembly of claim 7, further comprising a coupling mechanism configured to couple the reload assembly to an adapter assembly of the surgical stapling device to facilitate release of the reload assembly from the adapter assembly.

10. The reload assembly of claim 7, wherein the knife carriage includes at least one hook member having a proximal end, the at least one locking tab disposed on the at least one hook member distally of the proximal end. ​

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