SURGICAL STAPLING DEVICE WITH FORCE REDUCTION MECHANISM

A manually operated surgical stapling device includes an end effector and a firing mechanism that is configured to reduce the torque required to fire staples from the end effector of the stapling device. The firing mechanism includes a trigger, a thrust bar, and a firing link that is secured to the trigger and engaged with the thrust bar. The trigger is coupled to a handle assembly of the stapling device and to the firing link to minimize the torque required to move the trigger between unactuated and actuated positions.

FIELD

This technology is generally related to surgical stapling devices and, more particularly, to a manually actuated surgical stapling device with a firing force reduction mechanism.

BACKGROUND

Surgical stapling devices are commonly used during a variety of surgical procedures to expedite dissection and suturing of tissue and minimize trauma to a patient. These devices can be manually operated or powered, e.g., motorized, and are available in a variety of configurations including linear stapling devices, circular stapling devices, and transverse stapling devices. Transverse stapling devices include an end effector that has an anvil assembly and a cartridge assembly that have axes that are transverse to a longitudinal axis of the surgical stapling device. The cartridge supports a plurality of staples that are simultaneously advanced into the anvil assembly when the stapling device is fired to form staples in tissue.

Manually actuated stapling devices include a trigger that is engaged with a thrust bar via a link such that operation of the trigger advances the thrust bar within the stapling device. The thrust bar is operatively engaged with a pusher that is supported within a staple cartridge of the cartridge assembly. When the thrust bar is advanced, the pusher is advanced within the staple cartridge to simultaneously eject the staples from the cartridge assembly into the anvil assembly. Typically, these stapling devices also include a knife assembly that is engaged with the pusher and the thrust bar and is advanced upon operation of the trigger to simultaneously cut tissue clamped between the anvil and cartridge assemblies as the staples are ejected into the anvil assembly. The simultaneous stapling and cutting of tissue requires a substantial driving torque to be applied to the trigger by a clinician to actuate the stapling device.

A continuing need exists in the art for a surgical stapling device that includes a mechanism for minimizing the driving torque required to actuate the stapling device.

SUMMARY

This disclosure is directed to a manually operated surgical stapling device that includes an end effector and a firing mechanism to reduce the torque required to actuate a trigger to fire staples and cut tissue.

Aspects of this disclosure are directed to a surgical stapling device that includes a handle assembly, an elongate body, and an end effector. The handle assembly includes a housing, a firing link, and a trigger. The housing defines a stationary handle. The trigger is mounted to the housing by a first pivot member and has a first portion defining a grip and a second portion having a second end spaced from the first portion. The firing link defines a longitudinal axis “Y” and has a first end portion and a second end portion. The first end portion of the firing link is coupled to the second portion of the trigger by a second pivot member. The trigger is pivotable about the first pivot member towards the stationary handle through a firing stroke from an unactuated position to an actuated position. An axis “Z” extends through the first and second pivot members. The elongate body extends distally from the handle assembly and includes a frame and a thrust bar. The thrust bar is movably supported on the frame between retracted and advanced positions. The frame has a distal portion and a proximal portion. The thrust bar defines a longitudinal axis “X” and has a distal portion and a proximal portion. The proximal portion of the thrust bar is engaged with the second end portion of the firing link such that movement of the trigger through the firing stroke moves the thrust bar from the retracted position to the advanced position. The end effector is supported on the distal portion of the frame of the elongate body and includes an end effector frame, an anvil assembly, and a cartridge assembly. The end effector frame supports the anvil assembly and the cartridge assembly. The cartridge assembly includes a cartridge body, a knife assembly, and a pusher. The knife assembly is engaged with the distal portion of the thrust bar such that movement of the thrust bar from its retracted position to its advanced position moves the knife assembly and the pusher within the cartridge body from retracted positions to advanced positions. The axes “Y” and “Z” define an angle3, wherein the angle β is from about 95 degrees to about 110 degrees when the trigger is in the unactuated position and from about 155 degrees to about 170 degrees when the trigger is in the actuated position.

Other aspects of the disclosure are directed to a handle assembly that includes a housing, a firing link, a trigger, and a thrust bar. The housing defines a stationary handle. The trigger is mounted to the housing by a first pivot member and has a first portion defining a grip and a second portion having a second end spaced from the first portion. The firing link defines a longitudinal axis “Y” and has a first end portion and a second end portion. The first end portion of the firing link is coupled to the second portion of the trigger by a second pivot member. The trigger is pivotable about the first pivot member towards the stationary handle through a firing stroke from an unactuated position to an actuated position. The thrust bar extends from a distal portion of the housing and defines a longitudinal axis “X”. An axis “Z” extends through the first and second pivot members. The axes “Y” and “Z” define an angle β, wherein the angle β is from about 95 degrees to about 110 degrees when the trigger is in the unactuated position and from about 155 degrees to about 170 degrees when the trigger is in the actuated position.

Other aspects of this disclosure are directed to a surgical stapling device that includes a handle assembly, an elongate body, and an end effector. The handle assembly includes a housing, a firing link, and a trigger. The housing defines a stationary handle. The trigger is mounted to the housing by a first pivot member and has a first portion defining a grip and a second portion having a second end spaced from the first portion. The firing link defines a longitudinal axis “Y” and has a first end portion and a second end portion. The first end portion of the firing link is coupled to the second portion of the trigger by a second pivot member. The trigger is pivotable about the first pivot member towards the stationary handle through a firing stroke from an unactuated position to an actuated position. An axis “Z” extends through the first and second pivot members. The elongate body extends distally from the handle assembly and includes a frame and a thrust bar. The thrust bar is movably supported on the frame between retracted and advanced positions. The frame has a distal portion and a proximal portion. The thrust bar defines a longitudinal axis “X” and has a distal portion and a proximal portion. The proximal portion of the thrust bar is engaged with the second end portion of the firing link such that movement of the trigger through the firing stroke moves the thrust bar from the retracted position to the advanced position. The end effector is supported on the distal portion of the frame of the elongate body and includes an end effector frame, an anvil assembly, and a cartridge assembly. The end effector frame supports the anvil assembly and the cartridge assembly. The cartridge assembly includes a cartridge body, a knife assembly, and a pusher. The knife assembly is engaged with the distal portion of the thrust bar such that movement of the thrust bar from its retracted position to its advanced position moves the knife assembly and the pusher within the cartridge body from retracted positions to advanced positions. The axes “X” and “Y” define an angle α, wherein the angle α, when the trigger is in the unactuated position, is greater the angle α when the trigger is in the actuated position.

In some aspects of the disclosure, the end effector frame includes first and second transverse portions and a longitudinal portion that interconnects the first and second transverse portions.

In certain aspects of the disclosure, the first and second transverse portions define a gap.

In aspects of the disclosure, the anvil assembly is supported on the first transverse portion and the cartridge assembly is supported adjacent the second transverse portion.

In some aspects of the disclosure, the stapling device includes a clamp slide assembly having a distal portion supported within the gap.

In certain aspects of the disclosure, the clamp slide assembly is movable between retracted and advanced positions to move the cartridge assembly in relation to the anvil assembly between open and clamped positions.

In aspects of the disclosure, the proximal portion of the thrust bar defines a recess and the distal portion of the firing link is received within the recess.

In some aspects of the disclosure, the first end portion of the firing link includes a C-shaped clip that receives the second pivot member.

In certain aspects of the disclosure, the first pivot member is positioned between the second pivot member and the grip of the trigger.

In aspects of the disclosure, the first pivot member is positioned proximally of the second pivot member when the trigger is in the unactuated position.

Other features of the disclosure will be appreciated from the following description.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. 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 disclosure in virtually any appropriately detailed structure.

In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician during use of the stapling device in its customary manner, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician during use of the stapling device in its customary manner. In addition, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. Further, directional terms such as front, rear, upper, lower, top, bottom, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

This disclosure is directed to a manually operated surgical stapling device that includes an end effector and a firing mechanism to reduce the torque required to fire staples and cut tissue. The firing mechanism includes a trigger, a thrust bar, and a firing link that is secured to the trigger and engaged with the thrust bar. The trigger is coupled to a housing of a handle assembly of the stapling device about a first pivot member and coupled to a first end of the firing link about a second pivot member. A second end of the firing link is engaged with the thrust bar such that movement of the trigger about the first pivot member effects longitudinal movement of the thrust bar in relation to the end effector. The first and second pivot members are positioned on the trigger to minimize the torque required to move the trigger between unactuated and actuated positions.

FIGS.1and2illustrate a “Prior Art” surgical stapling device according to aspects of the disclosure shown generally as stapling device10. The stapling device10includes a handle assembly12, an elongate body14that extends distally from the handle assembly12, and an end effector16that is supported on a distal portion of the elongate body14. The elongate body14defines a longitudinal axis “X”. The handle assembly12includes a housing18that defines a stationary handle20and supports a movable trigger22. In aspects of the disclosure, the trigger22is supported by the housing18to pivot towards the stationary handle20in the direction of arrow “A” between non-actuated and actuated positions to actuate the end effector16, i.e., move the end effector16between open and clamped positions and fire the stapling device10. The handle assembly12includes a release button28that can be depressed to move the end effector16from the clamped position to the open position. For a more detailed description of a representative handle assembly12, see, e.g., U.S. Pat. No. 6,817,508 (“the '508 patent”).

The stapling device10includes a frame32that extends from the handle assembly12and includes a distal portion that supports the end effector16. The frame32includes spaced frame members that define a channel that receives a thrust bar38and the alignment pin pusher (not shown). The thrust bar38is movable within the channel of the frame32between retracted and advanced positions in response to movement of the trigger22in the direction of arrow “A” to actuate the stapling device10. The channel defined by the frame32also receives a clamp slide assembly (not shown) that extends into the end effector16as described in further detail below. For a more detailed description of the interaction between the trigger22, the thrust bar38, and the clamp slide assembly, see the '508 patent.

The end effector16includes an end effector frame42and a cartridge assembly44. The end effector frame42is secured to the distal portion of the frame32of the stapling device10and includes a first transverse portion46, a second transverse portion48, and a longitudinal portion50that interconnects the first transverse portion46and the second transverse portion48. The first and second transverse portions46,48are spaced from each other to define a gap52between the first and second transverse portions46,48. In some aspects of the disclosure, the first and second transverse portions46,48are curved along axes transverse to the longitudinal axis “X” of the elongate body14of the stapling device10. In some aspects of the disclosure, the first and second transverse portions46,48are formed from a plurality of linear portions, e.g., three, that are positioned at angles in relation to each other to define a curved configuration. The first transverse portion46of the end effector frame42supports an anvil assembly51.

FIG.2illustrates a central portion of a firing mechanism of the stapling device10(FIG.1) which includes the thrust bar38, the trigger22, and a firing link54. In aspects of the disclosure, the trigger22includes a first end portion56forming a grip (FIG.1) and a second end portion58. The second end portion58of the trigger22is pivotably secured to the housing18(FIG.1) by a first pivot member60and pivotably secured to the firing link54by a second pivot member62. The second pivot member62is positioned nearer an end of the trigger22opposite the first end portion56of the trigger22such that when the trigger22is moved in the direction of arrow “A” from the unactuated position (FIG.1) towards the actuated position, the second pivot member62moves distally in the direction indicated by arrow “B” about the first pivot member60.

The firing link54defines a longitudinal axis “Y” that extends through the second pivot member62and has a proximal portion70and a distal portion72. The proximal portion70is pivotably secured to the second end portion58of the trigger22by the second pivot member62. The distal portion72of the firing link54has a tapered configuration that is received in a recess76in the proximal end portion38aof the thrust bar38. An axis “Z” extends through the first and second pivot members60,62. The thrust bar38defines a longitudinal axis “X1” that is substantially parallel to the longitudinal axis “X” of the elongate body14.

When the trigger22is in the unactuated position, the axes “X1” and “Y” define an angle α and the axes “Y” and “Z” define an angle β. In this position, the first pivot member60is positioned distally of the second pivot member62. When tissue is clamped between the anvil assembly51and the cartridge assembly44and the stapling device10(FIG.1) is fired by pivoting the trigger22in the direction indicated by arrow “A” inFIG.1from its unactuated position to its actuated position, the torque needed to pivot the trigger22to the actuated position (assuming a constant load) can be calculated using the following formula:

where T is the torque, L is the load, and c (FIG.4A) is the distance between the first pivot member160and the second pivot member162. When the trigger22is moved from its unactuated position towards its actuated position, α changes from about 15 degrees to about 11 degrees and β changes from about 65 degrees to about 106 degrees. As is evident from the formula, where the load L is constant, the torque T increases most notably as β approaches 90 degrees. When β is 90 degrees, mechanical advantage of the trigger22is at its minimum. In the prior art stapling device10, β approaches 90 degrees at the end of the firing stroke. It is at this point that the load is at its maximum due to staple formation and cutting of tissue. This makes it difficult and tiresome for a clinician to move the trigger all the way through the firing stroke.

The present disclosure is directed to a stapling device shown generally as stapling device100in which the firing mechanism is modified to minimize the torque required to fire the stapling device100, i.e., move the trigger122from an unactuated position (FIG.5) towards an actuated position.

FIGS.3-6illustrate the stapling device100according to aspects of the disclosure. The stapling device100is similar to the stapling device10(FIG.1) and includes a handle assembly112, an elongate body114that extends distally from the handle assembly112, and an end effector116that is supported on a distal portion of the elongate body114. The elongate body114defines a longitudinal axis “X” (FIG.5). The handle assembly112includes a housing118that defines a stationary handle120and supports a movable trigger122. In aspects of the disclosure, the trigger122is supported by the housing118to pivot towards the stationary handle120in the direction of arrow “A” inFIG.3through a firing stroke from a non-actuated position (FIG.3) to an actuated position (FIG.6) to actuate the end effector116, i.e., move the end effector116between open and clamped positions and fire the stapling device100. The handle assembly112includes a release button128that can be depressed to move the end effector116from the clamped position to the open position. For a more detailed description of a representative handle assembly, see the '508 patent.

The stapling device100includes a frame132that extends distally from the handle assembly112and includes a distal portion132athat supports the end effector116. The frame132includes spaced frame members that define a channel that receives a thrust bar138and an alignment pin pusher (not shown). The thrust bar138is movable within the channel of the frame132between retracted and advanced positions in response to movement of the trigger122through the firing stroke to actuate the stapling device100. The channel defined by the frame132also receives a clamp slide assembly140(FIG.5A) that extends into the end effector116as described in further detail below. For a more detailed description of the interaction between the trigger122, the thrust bar138, and the clamp slide assembly140, see the '508 patent.

The end effector116includes an end effector frame142and a cartridge assembly144. The end effector frame142is secured to the distal portion of the frame132of the stapling device100and includes a first transverse portion146, a second transverse portion148, and a longitudinal portion150that interconnects the first transverse portion146and the second transverse portion148. The first and second transverse portions146,148are spaced from each other to define a gap152(FIG.5) between the first and second transverse portions146,148. In some aspects of the disclosure, the first and second transverse portions146,148are curved along axes transverse to the longitudinal axis “X” of the elongate body114of the stapling device100. In some aspects of the disclosure, the first and second transverse portions146,148are formed from a plurality of linear portions, e.g., three, that are positioned at angles in relation to each other to define a curved configuration. The first transverse portion146of the end effector frame142supports an anvil assembly151.

FIG.4illustrates a firing mechanism of the stapling device100which includes the thrust bar138, the trigger122, and a firing link154. In aspects of the disclosure, the trigger122includes a first end portion156that forms a grip and a second end portion158. The second end portion158of the trigger122is pivotably secured to the housing118(FIG.3) by a first pivot member160and pivotably secured to the firing link154by a second pivot member162. In aspects of the disclosure, the first pivot member160in integrally formed with the trigger122. The second pivot member162is positioned nearer a second end158aof the trigger122than the first pivot member160such that when the trigger122is moved through the firing stroke from the unactuated position (FIG.3) towards the actuated position (FIG.6), the second pivot member162moves distally in the direction indicated by arrow “B” inFIG.6about the first pivot member160.

In aspects of the disclosure, the firing link154has a first end154athat defines a C-shaped clip and the second end portion158of the trigger122defines a clevis164. The second pivot member162is supported within the clevis164and the first end154aof the firing link154is clipped about the second pivot member162to pivotably secure the firing link154to the second end portion158of the trigger122.

FIG.4Aillustrates the firing mechanism of the stapling device100. As illustrated, the firing link154defines a longitudinal axis “Y” that extends through the second pivot member162and has a distal portion154b. The proximal portion154aof the firing link is pivotably secured to the second end portion158of the trigger122by the second pivot member162. The distal portion154bof the firing link154has a tapered configuration that is received in a recess176formed in the proximal end portion138aof the thrust bar138. When the firing mechanism of the stapling device100is assembled, an axis “Z” extends through the first and second pivot members160,162, and the thrust bar138defines a longitudinal axis “X1” that is substantially parallel to the longitudinal axis “X” of the elongate body114. As illustrated, the first pivot member160is positioned proximally of the second pivot member162. The axes “X” and “Y” define an angle define an angle Q and the axes “Y” and “Z” define an angle β.

The firing mechanism of the stapling device100is configured such that the angle β is larger in the unactuated position than in the prior art such that the mechanical advantage is greatest at the end of the firing stroke where load is at its highest. In aspects of the disclosure, angle β can be from about 95 degrees to about 110 degrees in the unactuated position of the trigger122, and from about 155 degrees to about 170 degrees in the actuated position of the trigger122. In the unactuated position, Ω is from about 9 degrees to about 13 degrees when the trigger122is in the unactuated position and from about 7 degrees to about 11 degrees when the trigger122is in the actuated position. In some aspects of the disclosure, Ω is greater in the unactuated position than it is in the actuated position.

FIG.5Aillustrates a distal portion of the stapling device10including the end effector116, the clamp slide assembly140, and portions of the cartridge assembly144(FIG.3). The cartridge assembly144is supported within a distal portion of the clamp slide assembly140. The clamp slide assembly140is movable within the gap152to move the cartridge assembly144in relation to the anvil assembly151(FIG.3) between spaced and clamped positions. The cartridge assembly144includes a cartridge body170(FIG.3), a knife assembly172and a pusher174. The cartridge body170defines a cavity that receives the knife assembly172and the pusher174such that the knife assembly172and the pusher174are movable within the cartridge body170(FIG.3) between retracted and advanced positions. The knife assembly172includes a knife holder178and a cutting blade180that is secured to and extends distally from the knife holder178. The pusher174is positioned within the cartridge body170(FIG.3) distally of the knife holder178and defines a knife slot (not shown) that receives the cutting blade180. The pusher174includes fingers182that engage staples (not shown) supported within staple receiving slots of the cartridge body170.

The distal portion of the thrust bar138includes a widened portion138bthat is received in the end effector116and is engaged with the knife holder178of the knife assembly172. When the thrust bar138is advanced via movement of the trigger122through the firing stroke, the knife assembly172is moved within the cartridge body170(FIG.3) from its retracted position towards its advanced position to advance the cutting blade180from a position recesses within the cartridge body170to a position extending from the cartridge body170. The knife holder178is engaged with the pusher174such that movement of the knife assembly172from its retracted position towards its advanced position moves the pusher174within the cartridge body170(FIG.3) from its retracted position towards it advanced position to eject staples from the cartridge body170(FIG.3into the anvil assembly151.

FIG.6illustrates the stapling device100as the stapling device100is fired, i.e., as the trigger122in moved through the firing stroke from its unactuated position to its actuated position. When the trigger122is moved through its firing stroke in the direction of arrow “A”, the second pivot member162is rotated in a distal direction about the first pivot member160to advance the firing link154distally. As described above, the distal portion154bof the firing link154is received in the recess176in the proximal end portion138aof the thrust bar138such that the advancement of the firing link154causes longitudinal advancement of the thrust bar138. Advancement of the thrust bar138causes movement of the knife assembly172(FIG.5A) and the pusher174within the cartridge body170(FIG.3).