# Patent

## Title
Surgical stapling device including a manual retraction assembly

## Abstract

A surgical stapling device includes a tool assembly and a handle assembly. The tool assembly includes first and second jaw members. The handle assembly includes a rack and a retraction assembly. The rack is operatively coupled to the tool assembly and slidably supported in the handle assembly. The rack includes teeth extending along a length of the rack. The retraction assembly includes a shaft, a lever including a wheel and a lever handle extending from the wheel, and a pawl pivotably secured to the wheel. The lever is secured to the shaft for concomitant rotation therewith. The shaft is transitionable between a disengage state, in which, the pawl is disengaged from the teeth of the rack, and an engaged state, in which, the pawl engages the teeth of the rack such that when the lever handle is rotate about the shaft, the rack is retracted.

## Background
FIELD
The disclosure relates to surgical stapling devices, and more particularly, to a surgical stapling device having a manual retraction assembly.
BACKGROUND
Various types of surgical devices used to endoscopically treat tissue are known in the art. Such surgical devices are commonly used, e.g., for closure of tissue or organs in transection, resection, and anastomoses procedures, for occlusion of organs in thoracic and abdominal procedures, and for electrosurgically fusing or sealing tissue.
One example of such a surgical device is a surgical stapling device. Typically, surgical stapling devices include a tool assembly having an anvil assembly and a cartridge assembly, and a drive assembly. Typically, the drive assembly includes a flexible drive beam and a clamp member that is supported on a distal end of the drive beam. The drive assembly is movable to advance the clamp member through the tool assembly to approximate the cartridge and anvil assemblies and to advance an actuation sled through the cartridge assembly to eject staples from the cartridge assembly.
Surgical stapling devices can be manually actuated devices in which a clinician squeezes a trigger to actuate the stapling device, or powered stapling devices in which a clinician activates a motor within the stapling device to actuate the stapling device. Although powered stapling devices require less force to operate, difficulties may arise when the device loses power or components of the device break. In such instances, the device can remain clamped about tissue preventing removal of the device from a patient.
A continuing need exists in the art for a powered stapling device that includes a manual retraction assembly that can be manually operated to retract a drive assembly when power is lost or when the device is inoperable.
SUMMARY
In accordance with the disclosure, a surgical stapling device includes a tool assembly and a handle assembly. The tool assembly includes a first jaw member and a second jaw member that is transitionable between open and closed configurations in relation to the first jaw member. The handle assembly includes a rack and a retraction assembly. The rack is operatively coupled to the tool assembly and slidably supported in the handle assembly. The rack includes teeth extending along a length of the rack. The retraction assembly includes a shaft, a lever including a wheel and a lever handle extending from the wheel, and a pawl pivotably secured to the wheel. The lever is secured to the shaft for concomitant rotation therewith. The shaft is transitionable between a disengage state, in which, the pawl is disengaged from the teeth of the rack, and an engaged state, in which, the pawl engages the teeth of the rack such that when the lever handle is rotate about the shaft, the rack is retracted.
In an aspect, the shaft of the retraction assembly may be disposed orthogonal to the rack.
In another aspect, the shaft may be laterally slidable between the disengaged and engaged states.
In yet another aspect, the lever handle of the lever may extend tangentially from the wheel.
In still yet another aspect, the shaft may have a detent that secures the shaft to the handle assembly.
In still yet another aspect, the handle assembly may define first and second circular grooves to receive the detent of the shaft such that when the detent is received in the first circular groove of the handle assembly the shaft is in the disengaged state and when the detent is received in the second circular groove of the handle assembly the shaft is in the engaged state.
In an aspect, the rack may include a flat portion extending along the length of the rack. The pawl may engage the flat portion when the shaft is in the disengaged state.
In another aspect, the retraction assembly may further include a spring to bias the pawl towards the teeth of the rack.
In yet another aspect, the pawl may be pivotable about a pivot on the wheel. The pivot may be radially offset from the center of the wheel.
In still yet another aspect, the handle assembly may further include an electric motor operatively coupled to the rack to cause axial displacement of the rack.
In still yet another aspect, the handle assembly may include a housing defining a window. The window may provide access to the lever handle of the retraction assembly disposed within the housing.
In accordance with another aspect of the disclosure, a surgical stapling device includes a tool assembly and a handle assembly. The tool assembly includes a first jaw member and a second jaw member that is transitionable between open and closed configurations in relation to the first jaw member. The handle assembly includes a support frame, a rack slidably disposed on the support frame, and a retraction assembly. The rack includes lateral sides having respective teeth extending along a length of the rack. The rack is operatively coupled to the tool assembly. The retraction assembly includes a lever and a pair of pawls. The lever includes an elongate portion and lateral wings extending laterally outwards form the elongate portion. The pair of pawls is selectively positioned to engage the teeth on the lateral sides of the rack. The lever is transitionable between a disengaged state, in which, the pair of pawls is disengaged from the teeth of the rack, and an engaged state, in which, the pair of pawls is engaged with the teeth of the rack such that lateral displacement of the lever causes retraction of the rack.
In an aspect, the elongate portion of the lever may have a distal portion. The lateral wings may extend laterally outwards from the distal portion of the elongate portion.
In another aspect, each lateral wing of the lever may include a peg configured to pivotably support a corresponding pawl of the pair of pawls.
In yet another aspect, each pawl of the pair of pawls may include a tubular member configured to receive the corresponding peg of the lateral wing of the lever.
In still yet another aspect, the lateral sides of the rack may include respective flat portions extending along a length of the rack such that the pair of pawls engage the flat portions of the rack when the lever is in the disengaged state.
In still yet another aspect, the retraction assembly may further include a spring configured to bias the pair of pawls towards the lateral sides of the rack.
In still yet another aspect, the handle assembly may further include an electric motor that is operatively coupled to the rack.
In an aspect, the handle assembly may further include a battery that supplies power to the electric motor.
In another aspect, the support frame of the handle assembly may include a hitch having a boss that pivotably couples the lever thereto.



BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects and features of this disclosure will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings wherein like reference numerals identify similar or identical elements.
FIG. 1 is a perspective view of a surgical stapling device in accordance with the disclosure;
FIG. 2 is a partial perspective view of a handle assembly of the surgical stapling device of FIG. 1 with a housing half removed;
FIG. 3 is an enlarged view of the indicated area of detail of FIG. 2;
FIG. 4 is an exploded perspective view of a manual retraction assembly of the surgical stapling device of FIG. 1;
FIG. 5 is a cross-sectional view of the manual retraction assembly of FIG. 3 taken along section line 5-5 of FIG. 3;
FIG. 6 is a cross-sectional view of the manual retraction assembly of FIG. 5, illustrating a shaft of the manual retraction assembly in an engaged state;
FIGS. 7 and 8 are partial perspective views of the manual retraction assembly of FIG. 6, illustrating use thereof;
FIG. 9 is a perspective view of a handle assembly for use with the surgical stapling device of FIG. 1 in accordance with another aspect of the disclosure;
FIG. 10 is a partial perspective view of the handle assembly of FIG. 9 with a housing half removed;
FIG. 11 is an enlarged perspective view of the indicated area of detail of FIG. 10;
FIG. 12 is an exploded perspective view of a manual retraction assembly of the handle assembly shown in FIG. 9;
FIG. 13 is a side cross-sectional view taken along section line 13-13 of FIG. 11;
FIGS. 14 and 15 are side cross-sectional views of a hitch of a support frame of the manual retraction assembly of FIG. 12, illustrating use thereof; and
FIGS. 16 and 17 are top views of the manual retraction assembly of FIG. 10, illustrating use thereof.



DETAILED DESCRIPTION
The surgical stapling device including a manual retraction assembly disclosed herein is described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term “distal” refers to the portion of the device that is being described which is farther from a user in a conventional use of the surgical stapling device, while the term “proximal” refers to the portion of the device that is being described which is closer to a user in a conventional use of the surgical stapling device. In addition, the terms parallel and perpendicular are understood to include relative configurations that are substantially parallel and substantially perpendicular up to about + or −10 degrees from true parallel and true perpendicular. Further, to the extent consistent, any or all of the aspects detailed herein may be used in conjunction with any or all of the other aspects detailed herein.
With reference to FIGS. 1 and 2, there is provided a surgical stapling device 200 for use in stapling tissue. The surgical stapling device 200 generally includes a handle assembly 202 and an elongate tubular member 205 extending distally from the handle assembly 202. A reload 106 is removably coupled to a distal end 105 of the elongate tubular member 205 and includes a shaft portion 109 and a tool assembly 107 supported on the shaft portion 109. The tool assembly 107 includes first jaw member 108 and a second jaw member 110 that is movable in relation to the first jaw member 108 between an open configuration for positioning tissue between the first and second jaw members 108, 110 and a closed configuration for clamping tissue between the first and second jaw members 108, 110 and subsequently stapling tissue. The first jaw member 108 supports an anvil 111 and the second jaw member 110 releasably supports a staple cartridge 112. It is envisioned that the staple cartridge 112 may be removable and replaceable. It is also envisioned that the reload 106 may be part of a robotic surgical system.
The handle assembly 202 of the surgical stapling device 200 includes a housing 204, a stationary grip 222 and a rotation knob assembly 234. Buttons 26a, 26b on the stationary grip 222 of the handle assembly 202 allow for actuation of the tool assembly 107. When the button 26a is pressed, an actuation shaft (not shown) is advanced to transition the tool assembly 107 from the open configuration to the closed configuration and subsequently actuates the surgical stapling device 200 to apply lines of staples to tissue. In particular, when the button 26a is pressed, an electrical motor 300 in the stationary grip 222 is activated to impart rotational output of the electrical motor 300 to gears such as, e.g., a bevel gear 170 (FIG. 5), which operatively engages a pinion gear that operatively engages teeth 332 of a rack 330 to cause axial displacement of the rack 330. The rack 330 is operatively coupled to the actuation shaft to impart axial displacement to the actuation shaft to perform the functions of the tool assembly 107. In particular, the rack 330 is slidably supported on a support frame 400. In an aspect, the handle assembly 202 may include a battery 310 to supply power to the electrical motor 300. When the button 26b is pressed, a firing mechanism of the surgical stapling device 200 is retracted and the tool assembly 107 is transitioned from the closed configuration to the open configuration.
In order to provide proper orientation of the tool assembly 107 relative to tissue to be stapled, the surgical stapling device 200 is additionally provided with the rotation knob assembly 234 mounted on the handle assembly 202. Rotation of the rotation knob assembly 234 about a longitudinal axis “A-A” of the surgical stapling device 200 rotates the tool assembly 107 about the longitudinal axis “A-A.” The surgical stapling device 200 is illustrated as an electrically powered stapling device including the electrically powered handle assembly 202 that may support one or more batteries. Examples of electrically powered surgical stapling devices can be found in U.S. Pat. Nos. 9,055,943 and 9,023,014. In addition, reference may be made to U.S. Pat. No. 9,717,498, the entire contents of which is incorporated herein by reference, for a detailed discussion of the construction and operation of the surgical stapling device 200.
FIGS. 2 and 3 illustrate the handle assembly 202 including a manual retraction assembly 500 in accordance with the disclosure. The manual retraction assembly 500 serves as an alternative, fail-safe mechanism to the powered retraction mechanism. As best shown in FIGS. 3 and 4, the manual retraction assembly 500 includes a shaft 502, a lever 520, a spring 540, a pawl 550, and retraction teeth 560 positioned on the rack 330. The shaft 502 extends transversely across the support frame 400 that slidably supports the rack 330. Opposing end portions 502a (only one shown) of the shaft 502 are slidably supported on the housing of the handle assembly 202. In particular, the housing 204 of the handle assembly 202 includes bosses 206 (only one shown) that laterally oppose each other and extend inwardly from the housing 204. Each boss 206 defines a bore to slidably receive the shaft 502. One end portion 502a of the opposing end portions 502a of the shaft 502 has a detent 504 (FIG. 4) configured to engage an inner or outer circular groove 207a, 207b (FIG. 5) in the boss 206. Placement of the detent 504 in the outer or inner circular groove 207a, 207b corresponds to a disengaged or engaged state of the shaft 502, as will be described below.
The lever 520 includes a wheel 522 and a lever handle 526 that tangentially extends from the wheel 522. The wheel 522 concentrically defines a bore 524. The bore 524 receives the shaft 502 therethrough. The wheel 522 is secured to the shaft 502 to be movable as a single construct therewith. The wheel 522 includes a boss 528 that is radially offset from the center of the wheel 522. The boss 528 is received through a bore 552 of the pawl 550. The spring 540 is provided to bias the pawl 550 away from the lever 520 and towards the retraction teeth 560 of the rack 330. The rack 330 has the retraction teeth 560 on a first side 330a of the rack 330, and teeth 332 on a second side 330b of the rack 330 for use with the powered retraction mechanism. The retraction teeth 560 are arranged along a length of the rack 330. In addition, the first side 330a of the rack 330 further includes a flat portion 331 that extends along a length of the rack 330 adjacent the retraction teeth 560. Under such a configuration, the shaft 502 of the manual retraction assembly 500 is movable laterally between a disengaged state, in which, the pawl 550 is in registration with the flat portion 331 of the rack 330 during the use of the powered retraction mechanism, and an engaged state, in which, the pawl 550 is in registration with the retraction teeth 560 of the rack 330 for manual retraction of the rack 330, as will be described below.
FIGS. 5 and 6 illustrate the shaft 502 of the manual retraction assembly 500 that is movable laterally between the disengaged state (FIG. 5) and the engaged state (FIG. 6). As shown in FIG. 5, when the shaft 502 is in the disengaged state, the detent 504 of the shaft 502 is received in the outer circular groove 207a of the boss 206 of the housing 204 of the handle assembly 202. At this time, the pawl 550 is in registration with the flat portion 331 of the rack 330 such that the manual retraction assembly 500 does not interfere with axial displacement of the rack 330 by the motor 300 (FIG. 2). As shown in FIG. 6, the clinician may transition the shaft 502 to the engaged state by moving the shaft 502 in the direction of an arrow “A” such that the detent 504 of the shaft 502 is received in the inner circular groove 207b of the boss 206 of the housing 204. Movement of the shaft 502 to the engaged state imparts movement to the lever 520 in the direction of arrows “E” such that the pawl 550 supported on the lever 520 is in registration with the retraction teeth 560 of the rack 330.
FIGS. 7 and 8 illustrate the retraction of the rack 330 through the use of the lever 520 after the shaft 502 is transitioned to the engaged state. In use, in order to access the lever 520, the clinician removes the cover 209 (FIG. 1) of the handle assembly 202. The lever handle 526 of the lever 520 may rest on a surface of the support frame 400 or may be substantially parallel to the longitudinal axis “A-A” (FIG. 1) of the surgical stapling device 200. The clinician may rotate the lever handle 526 in the direction of an arrow “C” in FIG. 7, which, in turn, causes the pawl 550 to displace the rack 330 in the direction of an arrow “P” in FIG. 8, thereby retracting the rack 330. The ratchet teeth 560 are angled, e.g., define an acute angle with respect to the longitudinal axis “A-A”, to enable axial displacement of the rack 330 in a single direction (in the direction of the arrow “P”) when the lever handle 526 is rotated. Under such a configuration, for example, the lever handle 526 may be moved in a direction opposite of the arrow “C” while the rack 330 remains stationary. The lever handle 526 may be moved in the direction opposite of the arrow “C” to reset the pawl 550 for additional axial displacement of the rack 330.
FIG. 9 illustrates a handle assembly 1202 in accordance with another aspect of the disclosure. Components of the handle assembly 1202 that are substantially similar to the components of the handle assembly 202 (FIG. 1) will not be described to avoid obscuring the disclosure in unnecessary detail. The handle assembly 1202 includes a manual retraction assembly 1500 (FIG. 10). A proximal portion 1204a of a housing 1204 of the handle assembly 1202 defines a window 1206 through which a proximal end portion 1520a of a lever 1520 of the manual retraction assembly 1500 extends. The housing 1204 of the handle assembly 1202 further includes a battery cover 315 that may be removed to provide access to the lever 1520 after the batteries 310 are removed from the housing 1204, as will be described below.
FIGS. 10 and 11 illustrate the manual retraction assembly 1500 that includes a lever 1520, a spring 1540, pawls 1550, and retraction teeth 1560 positioned on a rack 1330. The rack 1330 is slidably supported on a support frame 1400. The rack 1330 is operatively coupled to the motor 300 via a bevel gear 1170 (FIG. 16) and a pinion gear to convert rotational output of the motor 300 to axial displacement of the rack 1330. The manual retraction assembly 1550 serves as an alternative, fail-safe mechanism to the powered retraction mechanism in the event of loss of power or malfunction. As shown in FIG. 12, the support frame 1400 includes a proximal portion 1400a having a hitch 1402. The hitch 1402 has a boss 1404 that is substantially orthogonal to a longitudinal axis “L-L” (FIG. 10) defined by the handle assembly 1202. In particular, the boss 1404 has detents 1406a, 1406b that are spaced apart along a length of the boss 1404. The detents 1406a, 1406b are used to support the lever 1520 at a position along the length of the boss 1404, as will be described below.
FIG. 12 further illustrates the lever 1520 that includes an elongate portion 1522 and lateral wings 1524 extending laterally outwards from a distal portion 1522b of the elongate portion 1522. Each lateral wing 1524 has a peg 1526 that is configured to receive a corresponding pawl 1552, 1554. The distal portion 1522b of the elongate portion 1522 defines a bore 1528 that is configured to receive the boss 1404 of the support frame 1400. In addition, an inner wall defining the bore 1528 may define a circumferential groove (not shown) to receive the detents 1406a, 1406b to facilitate placement of the lever 1520 on the boss 1404. The proximal portion 1520a of the lever 1520 extends proximally through a window 1204 (FIG. 10) of the handle assembly 1202. Under such a configuration, the lever 1520 is laterally movable relative to the rack 1330 about the boss 1404 of the support frame 1400. The rack 1330 is in a superposed relation to the lever 1520. The pawls 1552, 155 include respective tubular members 1552a, 1554a and respective fingers 1552b, 1554b. The tubular members 1552a, 1554a receive a corresponding peg 1526 of the lever 1520 such that the pawls 1552, 1554 are pivotable about the respective tubular members 1552a, 1554a. 
The spring 1540 is supported on the rack 1330 and is coupled to the pawls 1552, 1554 to bias the pawls 1552, 1554 towards each other and towards the rack 1330. The rack 1330 has lateral sides 1336, 1338 that have respective retraction teeth 1560 along a length of thereof and further include respective flat portions 1331 extending along the length thereof. Under such a configuration, the lever 1520 is selectively transitionable between a disengaged state, in which, the pawls 1552, 1554 engage the respective flat portions 1331 of the rack 1330, and an engaged state, in which, the pawls 1552, 1554 engage the respective retraction teeth 1560 of the rack 1330. The retraction teeth 1560 are angled (e.g., defining an acute angle relative to an axis defined by the rack 1330) to enable axial displacement of the rack 330 in a single direction when lever handle 526 is moved.
In use, the battery cover 315 (FIG. 9) and the batteries 310 are removed from the housing 1204 to create an opening 1207 to access the lever 1520, as shown in FIG. 13. The clinician moves the lever 1520 in the direction of arrows “U” such that the lever 1520 engages the detent 1406a (FIG. 12) on the boss 1404 of the hitch 1402, as shown in FIGS. 14 and 15. In this manner, the pawls 1552, 1554 are transitioned from the disengaged state, in which, the pawls 1552, 1554 engage the respective flat portions 1331 (FIG. 11) of the rack 1330, to the engaged state, in which, the pawls 1552, 1554 engage the respective retraction teeth 1560. At this time, the clinician pivots the lever 1520 in the direction of an arrow “F” (FIG. 16) about the boss 1404 (FIG. 12) of the hitch 1402 such that the pawls 1552, 1554 displace the rack 1330 in the direction of an arrow “M”, as shown in FIG. 16. Then the clinician pivots the lever 1520 in the direction of an arrow “S” (FIG. 17) about the boss 1404 of the hitch 1402 such that the pawls 1552, 1554 further displace the rack 1330 in the direction of the arrow “M”, as shown in FIG. 17. In this manner, the clinician may manually retract the rack 1330. The clinician may repeat such pivoting of the lever 1520 as needed to effect the desired amount of retraction.
While the disclosure has been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

## Claims

1. A surgical stapling device comprising:
a tool assembly including a first jaw member and a second jaw member that is transitionable between open and closed configurations in relation to the first jaw member; and
a handle assembly including:
a boss defining a bore;
a rack operatively coupled to the tool assembly and slidably supported in the handle assembly, the rack including teeth extending along a length of the rack; and
a retraction assembly including:
a shaft slidably disposed in the bore of the boss, the shaft slidable between a first position defining a disengaged state of the shaft and a second position defining an engaged state of the shaft;
a lever including a wheel and a lever handle extending from the wheel, the lever secured to the shaft for concomitant rotation therewith; and
a pawl pivotably secured to the wheel, wherein when the shaft is in the disengaged state, the pawl is disengaged from the teeth of the rack, and when the shaft is in the engaged state, the pawl engages the teeth of the rack such that when the lever handle is rotated about the shaft, the rack is retracted.

2. The surgical stapling device according to claim 1, wherein the shaft of the retraction assembly is disposed orthogonal to the rack.

3. The surgical stapling device according to claim 1, wherein the lever handle of the lever extends tangentially from the wheel.

4. The surgical stapling device according to claim 1, wherein the shaft has a detent that secures the shaft to the handle assembly.

5. The surgical stapling device according to claim 4, wherein the handle assembly defines first and second circular grooves to receive the detent of the shaft such that when the detent is received in the first circular groove of the handle assembly the shaft is in the disengaged state and when the detent is received in the second circular groove of the handle assembly the shaft is in the engaged state.

6. The surgical stapling device according to claim 1, wherein the rack includes a flat portion extending along the length of the rack, the pawl engaging the flat portion when the shaft is in the disengaged state.

7. The surgical stapling device according to claim 1, wherein the retraction assembly further includes a spring to bias the pawl towards the teeth of the rack.

8. The surgical stapling device according to claim 1, wherein the pawl is pivotable about a pivot on the wheel, the pivot being radially offset from the center of the wheel.

9. The surgical stapling device according to claim 1, wherein the handle assembly further includes an electric motor operatively coupled to the rack to cause axial displacement of the rack.

10. The surgical stapling device according to claim 1, wherein the handle assembly includes a housing defining a window, the window providing access to the lever handle of the retraction assembly disposed within the housing.

11. A surgical stapling device comprising:
a tool assembly including a first jaw member and a second jaw member that is transitionable between open and closed configurations in relation to the first jaw member; and
a handle assembly including:
a support frame;
a rack slidably disposed on the support frame, the rack including lateral sides having respective teeth extending along a length of the rack, the rack operatively coupled to the tool assembly; and
a retraction assembly including:
a lever including an elongate portion and lateral wings extending laterally outwards form the elongate portion; and
a pair of pawls selectively positioned to engage the teeth on the lateral sides of the rack, wherein the lever is transitionable between a disengaged state, in which, the pair of pawls is disengaged from the teeth of the rack, and an engaged state, in which, the pair of pawls is engaged with the teeth of the rack such that lateral displacement of the lever causes retraction of the rack.

12. The surgical stapling device according to claim 11, wherein the elongate portion of the lever has a distal portion, the lateral wings extending laterally outwards from the distal portion of the elongate portion.

13. The surgical stapling device according to claim 11, wherein each lateral wing of the lever includes a peg configured to pivotably support a corresponding pawl of the pair of pawls.

14. The surgical stapling device according to claim 13, wherein each pawl of the pair of pawls includes a tubular member configured to receive the corresponding peg of the lateral wing of the lever.

15. The surgical stapling device according to claim 11, wherein the lateral sides of the rack include respective flat portions extending along a length of the rack such that the pair of pawls engage the flat portions of the rack when the lever is in the disengaged state.

16. The surgical stapling device according to claim 11, wherein the retraction assembly further includes a spring configured to bias the pair of pawls towards the lateral sides of the rack.

17. The surgical stapling device according to claim 11, wherein the handle assembly further includes an electric motor that is operatively coupled to the rack.

18. The surgical stapling device according to claim 17, wherein the handle assembly further includes a battery that supplies power to the electric motor.

19. The surgical stapling device according to claim 11, wherein the support frame of the handle assembly includes a hitch having a boss that pivotably couples the lever thereto.

20. A surgical stapling device comprising:
a tool assembly including a first jaw member and a second jaw member that is transitionable between open and closed configurations in relation to the first jaw member; and
a handle assembly including:
a rack operatively coupled to the tool assembly and slidably supported in the handle assembly, the rack including teeth extending along a length of the rack; and
a retraction assembly including:
a shaft having a detent that secures the shaft to the handle assembly, the handle assembly defining first and second circular grooves to receive the detent such that when the detent is received in the first circular groove the shaft is in a disengaged state and when the detent is received in the second circular groove the shaft is in an engaged state;
a lever including a wheel and a lever handle extending from the wheel, the lever secured to the shaft for concomitant rotation therewith; and
a pawl pivotably secured to the wheel such that when the shaft is in the disengaged state, the pawl is disengaged from the teeth of the rack, and when the shaft is in the engaged state, the pawl engages the teeth of the rack such that when the lever handle is rotated about the shaft, the rack is retracted.