Patent Description:
<CIT> discloses a surgical stapler with a first handle portion that can include a latching mechanism rotatably mounted thereto which can be utilized to engage latch projections extending from a second handle porton and secure the first and second handle portions together. A locking mechanism can be configured to prevent, or at least inhibit, a drive bar from being advanced distally prior to the latching mechanism being moved into a predetermined position, such as, for example, a closed position and/or partially-closed position.

The present invention provides a surgical stapler as recited in claim <NUM>. Optional features are recited in the dependent claims.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate surgical devices including embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.

As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention as defined by the claims.

For clarity of disclosure, the terms "proximal" and "distal" are defined herein relative to a surgeon, or other operator, grasping a surgical instrument having a distal surgical end effector. The term "proximal" refers to the position of an element arranged closer to the surgeon, and the term "distal" refers to the position of an element arranged closer to the surgical end effector of the surgical instrument and further away from the surgeon. Moreover, to the extent that spatial terms such as "upper," "lower," "vertical," "horizontal," or the like are used herein with reference to the drawings, it will be appreciated that such terms are used for exemplary description purposes only and are not intended to be limiting or absolute. In that regard, it will be understood that surgical instruments such as those disclosed herein may be used in a variety of orientations and positions not limited to those shown and described herein.

As used herein, the terms "about" and "approximately" for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.

<FIG> and <FIG> show an exemplary linear surgical stapler (<NUM>) (also referred to as a "linear cutter") suitable for use in a variety of cutting and stapling procedures, such as a gastrointestinal anastomosis procedure. Linear surgical stapler (<NUM>) includes a cartridge half (<NUM>) (also referred to as a "reload half") and an anvil half (<NUM>) configured to releasably couple together to clamp tissue therebetween. Cartridge half (<NUM>) includes an elongate cartridge channel (<NUM>) having a proximal frame portion (<NUM>) that slidably retains a portion of a firing assembly (<NUM>), a distal jaw portion (<NUM>) that supports a staple cartridge (<NUM>) (or "reload"), and a pair of upright side flanges (<NUM>) arranged medially therebetween.

Cartridge half (<NUM>) further includes a clamp lever (<NUM>) pivotably coupled to an underside of cartridge channel (<NUM>) in approximate alignment with side flanges (<NUM>). Clamp lever (<NUM>) includes an elongate lever arm (<NUM>) having a free proximal end and a distal end that is pivotably coupled to cartridge channel (<NUM>) with a pivot pin (<NUM>). A pair of opposed jaws (<NUM>) extends distally from the distal end of lever arm (<NUM>) alongside flanges (<NUM>) of cartridge channel (<NUM>). Each jaw (<NUM>) includes a respective elongate slot (<NUM>) having a closed proximal end and an open distal end, and which defines upper and lower camming surfaces configured to engage a respective latch projection (<NUM>) of anvil half (<NUM>). As described below, clamp lever (<NUM>) is operable to pivot relative to cartridge channel (<NUM>) between open and closed positions to releasably clamp anvil half (<NUM>) against cartridge half (<NUM>) and thereby capture tissue layers therebetween.

As shown best in <FIG>, firing assembly (<NUM>) of cartridge half (<NUM>) includes a slider block (<NUM>) slidably retained within proximal frame portion (<NUM>) of cartridge channel (<NUM>), an actuator (<NUM>) (or "firing knob") movably coupled with slider block (<NUM>), and an elongate actuating beam (not shown) extending distally from slider block (<NUM>) and configured to couple with a sled (<NUM>) (see <FIG>) housed within staple cartridge (<NUM>). Actuator (<NUM>) of the present example is configured to pivot about the proximal end of cartridge half (<NUM>) to provide for "dual-sided firing" of stapler (<NUM>). Specifically, actuator (<NUM>) may be positioned along either lateral side of cartridge half (<NUM>) to perform a distal firing stroke, such that stapler (<NUM>) may be conveniently fired in a variety of orientations during a surgical procedure.

Slider block (<NUM>) is configured to be translatably driven within proximal frame portion (<NUM>) by actuator (<NUM>) between a proximal home position shown in <FIG> and <FIG>, and a distal fired position shown in <FIG>. In the proximal home position, slider block (<NUM>) abuts a post (<NUM>) fixed at a proximal end of cartridge channel (<NUM>). A free end of post (<NUM>) supports a laterally extending pivot pin (<NUM>). As described below, actuator (<NUM>) may be driven distally when stapler halves (<NUM>, <NUM>) are fully coupled together and clamp lever (<NUM>) is closed. Distal advancement of actuator (<NUM>) along either lateral side of stapler (<NUM>) drives slider block (<NUM>) and the elongate actuating beam distally, which in turn drives sled (<NUM>) distally through staple cartridge (<NUM>). As described below, distal translation of sled (<NUM>) through staple cartridge (<NUM>) provides for simultaneous stapling and cutting of tissue clamped between stapler halves (<NUM>, <NUM>).

As shown best in <FIG> and <FIG>, anvil half (<NUM>) of linear surgical stapler (<NUM>) includes an elongate anvil channel (<NUM>) having a proximal frame portion (<NUM>) and a distal jaw portion (<NUM>). Anvil channel (<NUM>) further includes a latch feature in the form of a pair of projections (<NUM>) that extend transversely from a medial portion of anvil channel (<NUM>) in a direction toward cartridge half (<NUM>). Each latch projection (<NUM>) may include a circular rotating cap configured to be captured within the slot (<NUM>) of a respective clamp lever jaw (<NUM>) when anvil half (<NUM>) is coupled with cartridge half (<NUM>) and clamp lever (<NUM>) is pivoted from the open position to the closed position, as described below. A pair of hooks (<NUM>) extend proximally from a proximal end of frame portion (<NUM>) and are configured to releasably capture opposed lateral ends of proximal pivot pin (<NUM>) of cartridge half (<NUM>). Distal jaw portion (<NUM>) supports an anvil surface in the form of an anvil plate (<NUM>) having a plurality of staple forming pockets (not shown), and additionally supports a distal tip member (<NUM>). In other versions of stapler (<NUM>), the anvil surface may be formed integrally with or otherwise be rigidly connected to distal jaw portion (<NUM>) of anvil channel (<NUM>).

Anvil half (<NUM>) of the present example further includes a staple height adjustment mechanism (<NUM>) mounted to a medial portion of anvil channel (<NUM>). Staple height adjustment mechanism (<NUM>) is operatively coupled with anvil plate (<NUM>), for example via one or more camming features (not shown), and includes a pair of user-engageable projections (<NUM>). Longitudinal adjustment of projections (<NUM>) between a plurality of predetermined positions causes anvil plate (<NUM>) to move transversely relative to distal jaw portion (<NUM>) of anvil channel (<NUM>). This enables adjustment of a transverse gap distance between anvil plate (<NUM>) and a deck (<NUM>) of staple cartridge (<NUM>) that defines the height of staples being formed. A larger gap distance, and thus a greater staple height, may be set when stapling tissues of greater thicknesses. Conversely, a smaller gap distance, and thus a smaller staple height, may be set when stapling tissues of lesser thicknesses. It will be appreciated that staple height adjustment mechanism (<NUM>) may be omitted in some versions, in which case the anvil surface may be fixed relative to anvil channel (<NUM>). For instance, the anvil surface may be formed integrally with or otherwise fixedly secured to distal jaw portion (<NUM>).

As shown best in in <FIG> and <FIG>, linear surgical stapler (<NUM>) further includes a plurality of shrouds (<NUM>, <NUM>, <NUM>) that cover select portions of stapler (<NUM>) and promote effective grip and manipulation of stapler (<NUM>) by an operator during use. In the present example, cartridge half (<NUM>) includes a first shroud (<NUM>) that covers an outwardly facing side of proximal frame portion (<NUM>) of cartridge channel (<NUM>). Cartridge half (<NUM>) further includes a second shroud (<NUM>) that covers an outwardly facing side of clamp lever (<NUM>) and is configured to pivot with clamp lever (<NUM>) relative to cartridge channel (<NUM>) and first shroud (<NUM>). Anvil half (<NUM>) includes a third shroud (<NUM>) that covers an outwardly facing side of proximal frame portion (<NUM>) of anvil channel (<NUM>), including proximal hooks (<NUM>). Each shroud (<NUM>, <NUM>, <NUM>) may be coupled with its respective components of stapler (<NUM>) by any suitable means apparent to those of ordinary skill in the art. Additionally, each shroud (<NUM>, <NUM>, <NUM>) may be formed of one or more materials and be provided with texturing suitable to promote effective gripping of the shroud (<NUM>, <NUM>, <NUM>) by an operator to enable safe and efficient use of stapler (<NUM>) during a surgical procedure.

As shown in <FIG> and <FIG>, staple cartridge (<NUM>) of the present example is an assembly that comprises a cartridge body (<NUM>), a pan (<NUM>) that covers an open lower side of cartridge body (<NUM>), and a plurality of staple drivers (<NUM>) housed within cartridge body (<NUM>) and each being configured to drive a respective staple (<NUM>). Cartridge body (<NUM>) includes a proximal end having coupling features (<NUM>) configured to releasably engage corresponding coupling features (not shown) of distal jaw portion (<NUM>) of cartridge channel (<NUM>), and a distal end defining a tapered nose (<NUM>). An upper side of cartridge body (<NUM>) defines a generally planar deck (<NUM>) through which a longitudinal slot (<NUM>) and a plurality of staple cavities (<NUM>) open. Each staple cavity (<NUM>) houses a respective staple driver (<NUM>) and a staple (<NUM>). As shown in <FIG>, an interior of cartridge body (<NUM>) slidably houses a sled (<NUM>) that comprises a sled body (<NUM>) and knife member (<NUM>). Lateral sides of sled body (<NUM>) support a plurality of cam ramps (<NUM>) that taper distally. A proximal end of sled body (<NUM>) includes a downwardly extending tab (<NUM>) configured to lockingly engage a distal end of the elongate actuating beam (not shown) of firing assembly (<NUM>) when staple cartridge (<NUM>) is mounted to cartridge half (<NUM>) of stapler (<NUM>). Knife member (<NUM>) extends upwardly from an upper side of sled body (<NUM>) and presents a distally facing cutting edge (<NUM>) configured to cut tissue.

Sled (<NUM>) is configured to translate distally through cartridge body (<NUM>) in response to distal actuation of firing assembly (<NUM>), such that knife member (<NUM>) translates distally through longitudinal slot (<NUM>) to cut tissue clamped between stapler halves (<NUM>, <NUM>). Simultaneously, cam ramps (<NUM>) translate distally through respective interior slots (not shown) of cartridge body (<NUM>) to actuate staple drivers (<NUM>) and staples (<NUM>) upwardly through staple cavities (<NUM>) so that free ends of staples (<NUM>) pierce through the clamped tissue and deform against staple forming pockets of anvil plate (<NUM>). In this manner, distal actuation of firing assembly (<NUM>) provides for simultaneous severing and stapling of tissue clamped between the distal end effector portions of stapler halves (<NUM>, <NUM>).

Linear surgical stapler (<NUM>) and staple cartridge (<NUM>) may be further configured and operable in accordance with one or more teachings of <CIT>; <CIT>; <CIT>; and/or <CIT>.

<FIG> show exemplary coupling of stapler halves (<NUM>, <NUM>) during a surgical procedure. As shown in <FIG>, the proximal end of anvil half (<NUM>) is aligned with the proximal end of cartridge half (<NUM>) such that proximal pivot pin (<NUM>) of cartridge half (<NUM>) is received by proximal hooks (<NUM>) of anvil half (<NUM>). With clamp lever (<NUM>) in the open position, anvil half (<NUM>) is then pivoted toward cartridge half (<NUM>), about proximal pivot pin (<NUM>), to direct latch projections of anvil half (<NUM>) into slots (<NUM>) of clamp lever jaws (<NUM>). Once latch projections (<NUM>) are received by clamp lever jaws (<NUM>), clamp lever (<NUM>) is pivoted toward the partially closed position shown in <FIG>. In this partially closed position of clamp lever (<NUM>), anvil half (<NUM>) is partially clamped with cartridge half (<NUM>) such that stapler (<NUM>) may now be held with a single hand without halves (<NUM>, <NUM>) undesirably separating from one another. Additionally, in this state, the distal portions of stapler halves (<NUM>, <NUM>) remain spaced apart from one another to permit positioning of tissue between the distal portions. It will be appreciated that tissue may be positioned between the distal portions of stapler halves (<NUM>, <NUM>) before or upon achieving this partially clamped state.

As shown in <FIG>, clamp lever (<NUM>) is then pivoted further toward its fully closed position such that the camming surfaces of clamp lever jaws (<NUM>) draw latch projections of anvil half (<NUM>) proximally against the closed proximal ends of slots (<NUM>) of clamp lever jaws (<NUM>), thereby fully clamping stapler halves (<NUM>, <NUM>) together with tissue positioned securely therebetween. Once halves (<NUM>, <NUM>) of stapler (<NUM>) are in a fully clamped state, actuator (<NUM>) may be manipulated to fire staple cartridge (<NUM>). In particular, as shown in <FIG>, actuator (<NUM>) is pivoted about the proximal end of stapler (<NUM>) to overlie one of the lateral sides of stapler (<NUM>). Actuator (<NUM>) is then driven distally to actuate firing assembly (<NUM>) in the manner described above and thereby simultaneously sever and staple the clamped tissue. Upon completing a distal firing stroke, actuator (<NUM>) may be returned to its proximal home position shown in <FIG>, and clamp lever (<NUM>) may then be opened to separate stapler halves (<NUM>, <NUM>) from one another and release the stapled and severed tissue.

As described above in connection with <FIG>, clamp lever (<NUM>) must be actuated from its fully open position to at least a partially closed position in which lever jaws (<NUM>) initially capture latch projections (<NUM>) of anvil half (<NUM>) in order to prevent separation of anvil half (<NUM>) from cartridge half (<NUM>). However, this initial coupling process requires the use of both hands of an operator, thus preventing the operator from being able to mount tissue to stapler (<NUM>) when clamp lever (<NUM>) is fully opened. Because it is generally easier to mount tissue to stapler halves (<NUM>, <NUM>) while clamp lever (<NUM>) is fully opened, thus allowing the distal portions of stapler halves (<NUM>, <NUM>) to be spaced further apart from one another, the operator will often enlist the help of an assistant in a "<NUM>-hands" assembly approach.

In many instances, it may be desirable for an operator to be able to mount tissue to the separate halves of a linear surgical stapler with the clamp lever in a fully open position and without the aid of an assistant, such that the operator may use a first hand to hold the stapler and a second hand to position tissue relative to the stapler. The exemplary stapler (<NUM>) described below includes features that enable proximal ends of the first and second stapler halves to remain coupled together while the clamp lever is in a fully open position. This configuration enables the operator to suitably manipulate stapler (<NUM>) with a first hand, while leaving the other hand free to manipulate tissue relative to stapler (<NUM>).

<FIG> and <FIG> show another exemplary linear surgical stapler (<NUM>) (or "linear cutter") that is generally similar to linear surgical stapler (<NUM>) described above except as otherwise described below. Linear surgical stapler (<NUM>) includes a cartridge half (<NUM>) (or "reload half") and an anvil half (<NUM>) configured to releasably couple together to clamp tissue therebetween for simultaneous cutting and stapling of the clamped tissue.

Cartridge half (<NUM>) includes an elongate cartridge channel (<NUM>) having a proximal frame portion (<NUM>) and distal jaw portion (<NUM>). Proximal frame portion (<NUM>) slidably retains a firing assembly (<NUM>) and includes a laterally opposed pair of upright side flanges (<NUM>). Each side flange (<NUM>) includes a vertical slot (<NUM>) arranged at a distal end thereof, and a tapered notch (<NUM>) arranged at a proximal end thereof. An outwardly projecting stiffening rib (<NUM>) extends longitudinally between distal slot (<NUM>) and the proximal notch (<NUM>) of each side flange (<NUM>) and is configured to provide the side flange (<NUM>) with enhanced stiffness. An outwardly flared upper segment (<NUM>) defines an upper edge of a proximal portion of each side flange (<NUM>) and is configured to facilitate receipt of anvil half (<NUM>) by cartridge half (<NUM>), as described in greater detail below. Each side flange (<NUM>) further includes an elongate firing slot (<NUM>) extending longitudinally between proximal notch (<NUM>) and distal slot (<NUM>) along a lower side of side flange (<NUM>). Elongate firing slots (<NUM>) are configured to guide firing assembly (<NUM>) between proximal and distal positions. Firing assembly (<NUM>) is described in greater detail below in connection with <FIG>.

Distal jaw portion (<NUM>) of cartridge channel (<NUM>) is configured to receive a staple cartridge (<NUM>) (or "reload"), which may be similar to staple cartridge (<NUM>) described above except as otherwise described below. Staple cartridge (<NUM>) includes a cartridge body (<NUM>) that houses a plurality of staple drivers and staples (not shown) similar to staple drivers (<NUM>) and staples (<NUM>). Cartridge body (<NUM>) further includes a longitudinal slot (<NUM>) configured to slidably receive a knife member (<NUM>) (see <FIG>) of firing assembly (<NUM>), and a pair of interior slots (not shown) configured to slidably receive a pair of cam ramps (<NUM>) (see <FIG>) of firing assembly (<NUM>). In other versions, staple cartridge (<NUM>) and firing assembly (<NUM>) may be alternatively configured such that knife member (<NUM>) and cam ramps (<NUM>) are housed within cartridge body (<NUM>), similar to staple cartridge (<NUM>). Staple cartridge (<NUM>) of the present version further includes a pair of proximal coupling legs (<NUM>) configured to be directed through an opening (not shown) in a lower wall of cartridge channel (<NUM>) and releasably couple to a clamp lever pivot pin (<NUM>) with a snap-fit engagement.

Cartridge half (<NUM>) further includes a clamp lever (<NUM>) pivotably coupled to cartridge channel (<NUM>) with clamp lever pivot pin (<NUM>), which is arranged in approximate alignment with distal slots (<NUM>) of cartridge channel side flanges (<NUM>). Clamp lever (<NUM>) includes an elongate lever arm (<NUM>) having a free proximal end (<NUM>) and a distal end that is pivotably coupled to a lower portion of cartridge channel (<NUM>) with pivot pin (<NUM>). A pair of opposed jaws (<NUM>) extend distally from the distal end of lever arm (<NUM>) alongside cartridge channel side flanges (<NUM>). Each jaw (<NUM>) includes a curved slot (<NUM>) having a closed proximal end and an open distal end configured to receive a latch projection of anvil half (<NUM>), as described below.

Clamp lever (<NUM>) is operable to pivot relative to cartridge channel (<NUM>) between an open position in which proximal end (<NUM>) of lever arm (<NUM>) is spaced from cartridge channel frame portion (<NUM>), and a closed position in which proximal end (<NUM>) confronts cartridge channel frame portion (<NUM>). Actuation of clamp lever (<NUM>) from the open position to the closed position operates to clamp anvil half (<NUM>) against cartridge half (<NUM>). In particular, the curvature of each jaw slot (<NUM>) defines respective upper and lower camming surfaces configured to engage and draw the respective latch projection of anvil half (<NUM>) toward cartridge channel (<NUM>) as clamp lever (<NUM>) is pivotably closed, as described below.

Cartridge half (<NUM>) of the present example further includes a resilient member shown in the form of a flat spring (<NUM>) that biases lever arm (<NUM>) toward the open position. Accordingly, flat spring (<NUM>) promotes disengagement of lever jaws (<NUM>) from anvil half (<NUM>) upon initial advancement of clamp lever (<NUM>) from the closed position toward the open position. Cartridge half (<NUM>) further includes a clamp lever latch member (<NUM>) arranged at proximal end (<NUM>) of lever arm (<NUM>). As described in greater detail below, clamp lever latch member (<NUM>) is resiliently biased to engage a proximal end of cartridge channel (<NUM>) and thereby releasably retain clamp lever (<NUM>) in the closed position, for instance while stapler (<NUM>) is being fired.

Anvil half (<NUM>) of linear surgical stapler (<NUM>) includes an elongate anvil channel (<NUM>) having a proximal frame portion (<NUM>) and a distal jaw portion (<NUM>). Proximal frame portion (<NUM>) includes a laterally opposed pair of upright side flanges (<NUM>) that are configured to be received between cartridge channel side flanges (<NUM>) when anvil half (<NUM>) is coupled with cartridge half (<NUM>). A distal latch projection in the form of a distal pin (<NUM>) extends laterally through the distal ends of anvil channel side flanges (<NUM>), and a proximal pivot projection in the form of a proximal pin (<NUM>) extends laterally through the proximal ends of anvil channel side flanges (<NUM>). Anvil pins (<NUM>, <NUM>) are configured to facilitate coupling of anvil half (<NUM>) with cartridge half (<NUM>) as described below.

Distal jaw portion (<NUM>) of anvil half (<NUM>) supports an anvil surface (<NUM>) having a plurality of staple forming pockets (not shown) configured to deform the legs of staples ejected by staple cartridge (<NUM>) when stapler (<NUM>) is fired. In some versions, anvil surface (<NUM>) may be formed integrally with or otherwise be rigidly connected to distal jaw portion (<NUM>), for example as described below in connection with <FIG>. In other versions, anvil surface (<NUM>) may be adjustable relative to distal jaw portion (<NUM>) in a manner similar to anvil plate (<NUM>) of stapler (<NUM>) described above. Distal jaw portion (<NUM>) of anvil half (<NUM>) additionally supports a tapered distal tip member (<NUM>).

Similar to linear surgical stapler (<NUM>), linear surgical stapler (<NUM>) includes a plurality of shrouds (<NUM>, <NUM>) that cover select portions of stapler (<NUM>) and promote effective grip and manipulation of stapler (<NUM>) by an operator during use. In particular, a clamp lever shroud (<NUM>) is affixed to and covers an outwardly facing side of clamp lever (<NUM>) such that clamp lever shroud (<NUM>) is configured to pivot with clamp lever (<NUM>) relative to cartridge channel (<NUM>). Additionally, an anvil shroud (<NUM>) is affixed to and covers an outwardly facing side of anvil channel (<NUM>). In some versions, anvil shroud (<NUM>) may be coupled with anvil channel (<NUM>) in accordance with the teachings of <CIT>, entitled "Clamping Assembly for Linear Surgical Stapler". It will be appreciated that in other versions, shrouds (<NUM>, <NUM>) may be coupled with clamp lever (<NUM>) and anvil channel (<NUM>) in a variety of other manners readily apparent to those of ordinary skill in the art.

During assembly of stapler halves (<NUM>, <NUM>), proximal pin (<NUM>) of anvil half (<NUM>) is directed into proximal tapered notches (<NUM>) of cartridge channel (<NUM>). Meanwhile, clamp lever (<NUM>) is held in the open position by resilient member (<NUM>) such that the open distal ends of curved jaw slots (<NUM>) align with the open upper ends of cartridge channel distal slots (<NUM>). Anvil half (<NUM>) is then pivoted about proximal pin (<NUM>) to direct distal pin (<NUM>) of anvil half (<NUM>) into vertical distal slots (<NUM>) of cartridge channel (<NUM>) and curved jaw slots (<NUM>) of clamp lever (<NUM>). Clamp lever (<NUM>) is then pivoted from the open position to the closed position, which causes the upper and lower camming surfaces of curved jaw slots (<NUM>) to engage and draw distal pin (<NUM>) toward the closed proximal ends of curved jaw slots (<NUM>). This action draws distal jaw portion (<NUM>) of anvil channel (<NUM>) closer toward distal jaw portion (<NUM>) of cartridge channel (<NUM>), thereby clamping any tissue positioned between anvil surface (<NUM>) and staple cartridge (<NUM>). When clamp lever (<NUM>) reaches the fully closed position, clamp lever latch member (<NUM>) engages the proximal end of cartridge channel (<NUM>) to maintain clamp lever (<NUM>) in the closed position. Stapler (<NUM>) may then be fired by actuating firing assembly (<NUM>) distally similar to firing assembly (<NUM>). After firing, firing assembly (<NUM>) is returned to its proximal home position, and clamp lever latch member (<NUM>) is disengaged from cartridge channel (<NUM>) to enable opening of clamp lever (<NUM>) and subsequent separation of stapler halves (<NUM>, <NUM>).

<FIG> show details of an exemplary retaining assembly (<NUM>) arranged at a proximal end of linear surgical stapler (<NUM>) and which is configured to releasably retain portions of anvil half (<NUM>) and firing assembly (<NUM>) as described below. Retaining assembly (<NUM>) of the present example includes an anvil latch member (<NUM>) and a detent member (<NUM>), both of which are rotatably coupled with a proximal end of cartridge channel (<NUM>) via a laterally extending pin (<NUM>) arranged proximally of firing slots (<NUM>).

As shown best in <FIG>, anvil latch member (<NUM>) includes a central body (<NUM>), a latch finger (<NUM>) extending upwardly from an upper side of central body (<NUM>), a release button (<NUM>) extending downwardly from a lower side central body (<NUM>), and a stop tab (<NUM>) arranged on an outwardly facing lateral side of central body (<NUM>) opposed from detent member (<NUM>). An upper end of latch finger (<NUM>) tapers distally and defines an upper cam ramp (<NUM>) configured to engage proximal pin (<NUM>) of anvil half (<NUM>) in the manner described below. Anvil latch member (<NUM>) further includes a central cutout feature (<NUM>) shaped to receive a portion of detent member (<NUM>) as described below, and an opening (<NUM>) extending laterally through central body (<NUM>).

Detent member (<NUM>) includes a generally cylindrical central body (<NUM>), a distal finger (<NUM>) extending distally from a distal side of central body (<NUM>), a hook element (<NUM>) extending proximally from a proximal side of central body (<NUM>), and a stop tab (<NUM>) arranged on an outwardly facing lateral side of central body (<NUM>) opposed from anvil latch member (<NUM>). As shown in <FIG>, a lateral side of detent member (<NUM>) that confronts anvil latch member (<NUM>) includes an annular recess (<NUM>) and a shaft (<NUM>) extending laterally from annular recess (<NUM>) in a direction toward anvil latch member (<NUM>). Distal finger (<NUM>) of detent member (<NUM>) includes a proximal uppercut feature (<NUM>) that defines a proximal cam ramp of distal finger (<NUM>), and a sloped distal end that defines a distal cam ramp of distal finger (<NUM>). These proximal and distal cam ramps of distal finger (<NUM>) are configured to interact with firing assembly (<NUM>) as described in greater detail below.

Anvil latch member (<NUM>) and detent member (<NUM>) are configured to mate together such that their inwardly facing lateral sides confront one another along a plane that extends generally parallel to a longitudinal axis of linear surgical stapler (<NUM>). Central body (<NUM>) of detent member (<NUM>) is received within central cutout feature (<NUM>) of anvil latch member (<NUM>) such that latch finger (<NUM>) and release button (<NUM>) of anvil latch member (<NUM>) laterally overlie central body (<NUM>) of detent member (<NUM>). Additionally, lateral shaft (<NUM>) of detent member (<NUM>) is received through lateral opening (<NUM>) of anvil latch member (<NUM>), such that anvil latch member (<NUM>) may rotate about shaft (<NUM>). Pin (<NUM>) is then received through a central bore of lateral shaft (<NUM>) and is secured at its lateral ends to cartridge channel side flanges (<NUM>), as shown in <FIG> and <FIG>. Accordingly, anvil latch member (<NUM>) and detent member (<NUM>) are arranged coaxially about a lateral axis defined by pin (<NUM>) and shaft (<NUM>). As described below, anvil latch member (<NUM>) and detent member (<NUM>) are configured to rotate independently from and relative to one another about the shared axis.

Retaining assembly (<NUM>) further includes a resilient member shown in the form of a torsion spring (<NUM>) positioned between anvil latch member (<NUM>) and detent member (<NUM>). A first lateral side of torsion spring (<NUM>) and a corresponding first spring leg (<NUM>) is captured within a complementary shaped recess (<NUM>) formed in central body (<NUM>) of anvil latch member (<NUM>). A second lateral side of torsion spring (<NUM>) is received within annular recess (<NUM>) of detent member (<NUM>) such that a corresponding second spring leg (<NUM>) is captured within a radially extending slot (<NUM>) formed in central body (<NUM>) of detent member (<NUM>). Torsion spring (<NUM>) is configured to resiliently bias anvil latch member (<NUM>) and detent member in opposite rotational directions about the lateral axis defined by pin (<NUM>). In particular, in the views depicted in <FIG> and <FIG>, torsion spring (<NUM>) is configured to bias anvil latch member (<NUM>) in a counter-clockwise direction about pin (<NUM>) such that latch finger (<NUM>) is biased distally. Additionally, torsion spring (<NUM>) is configured to bias detent member (<NUM>) in a clockwise direction such that distal finger (<NUM>) is biased upwardly and proximal hook element (<NUM>) is biased downwardly.

As shown in <FIG>, stop tab (<NUM>) of anvil latch member (<NUM>) is configured to abut the upper surface of an adjacent first stop notch (<NUM>) formed in the distal end of a corresponding first side flange (<NUM>) of cartridge channel (<NUM>). Additionally, stop tab (<NUM>) of detent member (<NUM>) is configured to abut the lower surface of an adjacent second stop notch (<NUM>) formed in the distal end of a corresponding second side flange (<NUM>) of cartridge channel (<NUM>). Anvil latch member stop tab (<NUM>) and its respective channel stop notch (<NUM>) are configured to interact such that anvil latch member (<NUM>) is biased toward a rotational orientation in which latch finger (<NUM>) extends generally vertically. Additionally, detent member stop tab (<NUM>) and its respective channel stop notch (<NUM>) are configured to interact such that detent member (<NUM>) is biased toward a rotational orientation in which distal finger (<NUM>) and proximal hook element (<NUM>) extend generally horizontally.

<FIG> show engagement of anvil latch member (<NUM>) with proximal pin (<NUM>) of anvil half (<NUM>) to provide for releasable coupling of the proximal end of anvil half (<NUM>) with the proximal end of cartridge half (<NUM>). <FIG> shows cartridge half (<NUM>) and anvil half (<NUM>) in a pre-assembled state in which anvil half (<NUM>) is separated from cartridge half (<NUM>), clamp lever (<NUM>) (not depicted) is in a fully open position, and firing assembly (<NUM>) is held in a proximal home position by distal finger (<NUM>) of detent member (<NUM>), as described in greater detail below. As shown in <FIG>, the proximal end of anvil half (<NUM>) is aligned with and brought toward the proximal end of cartridge half (<NUM>) such that proximal pin (<NUM>) is directed into proximal tapered notches (<NUM>) of cartridge channel (<NUM>) and contacts upper cam ramp (<NUM>) of anvil latch member (<NUM>). This engagement forces anvil latch member (<NUM>) to rotate clockwise such that latch finger (<NUM>) moves proximally, which allows proximal pin (<NUM>) to slip over the tapered distal tip of latch finger (<NUM>). As shown in <FIG>, anvil latch member (<NUM>) then snaps back counter-clockwise such that latch finger (<NUM>) hooks over and captures proximal pin (<NUM>), thereby coupling the proximal end of anvil half (<NUM>) with the proximal end of cartridge half (<NUM>). Because anvil latch member (<NUM>) is rotatable independently of detent member (<NUM>), detent member (<NUM>) remains rotationally stationary throughout the coupling steps shown in <FIG>.

As shown in <FIG>, release button (<NUM>) of anvil latch member (<NUM>) is exposed and accessible to an operator only when clamp lever (<NUM>) is in the open position. As shown in <FIG>, release button (<NUM>) extends through an opening formed in a bottom wall (<NUM>) of cartridge channel (<NUM>). As shown in <FIG>, clamp lever (<NUM>) in the closed position conceals and blocks access to release button (<NUM>), thereby preventing unintentional actuation of release button (<NUM>) and resulting separation of the proximal ends of stapler halves (<NUM>, <NUM>) during or immediately before a firing stroke. As shown in <FIG>, separation of the proximal ends of stapler halves (<NUM>, <NUM>) is achieved by opening clamp lever (<NUM>) and actuating release button (<NUM>) distally. As shown in <FIG>, this causes anvil latch member (<NUM>) to rotate clockwise, thereby driving latch finger (<NUM>) proximally to release proximal pin (<NUM>) of anvil half (<NUM>) so anvil half (<NUM>) may be pulled away from cartridge half (<NUM>).

As shown in <FIG>, a slider block (<NUM>) of firing assembly (<NUM>) is configured to releasably engage detent member (<NUM>) of retaining assembly (<NUM>) to provide an operator with a tactile indication of when firing assembly (<NUM>) is in a proximal home assembly, as described below. Referring briefly to <FIG>, slider block (<NUM>) includes a block body (<NUM>) that is slidably housed between side flanges (<NUM>) of cartridge channel (<NUM>), and a finger (<NUM>) extending proximally from a proximal end of block body (<NUM>). Block finger (<NUM>) has a rounded proximal end that defines a proximal cam ramp of block finger (<NUM>), and an undercut feature (<NUM>) that defines a distal cam ramp of block finger (<NUM>).

<FIG> shows firing assembly (<NUM>) in a proximal home position in which slider block (<NUM>) is arranged proximally within cartridge channel (<NUM>). In this proximal position, block finger (<NUM>) hooks over and interlocks with detent finger (<NUM>) such that the proximal cam ramp of detent finger (<NUM>) contacts the distal cam ramp of block finger (<NUM>). This interaction between block finger (<NUM>) and detent finger (<NUM>) urges detent member (<NUM>) slightly in a counter-clockwise direction (in the view of <FIG>), against the bias of torsion spring (<NUM>), such that detent stop tab (<NUM>) is slightly spaced from the lower surface of the respective cartridge channel stop notch (<NUM>). In response, torsion spring (<NUM>) urges detent member (<NUM>) in a clockwise direction so that detent finger (<NUM>) exerts an upwardly directed force on block finger (<NUM>). This exertion of forces provides a detent engagement that releasably retains firing assembly (<NUM>), via slider block (<NUM>), in the proximal home position.

As shown in <FIG>, when firing assembly (<NUM>) is actuated distally by an operator performing a firing stroke, block finger (<NUM>) drives detent finger (<NUM>) downwardly such that detent member (<NUM>) rotates in a counter-clockwise direction. As shown in <FIG>, as firing assembly (<NUM>) advances further distally, block finger (<NUM>) disengages detent finger (<NUM>) and the bias of torsion spring (<NUM>) rotates detent member (<NUM>) in a clockwise direction so that detent stop tab (<NUM>) abuts the lower surface of the respective cartridge channel stop notch (<NUM>). When detent member (<NUM>) assumes this rotational position, proximal hook element (<NUM>) of detent member (<NUM>) hooks over an upper tip (<NUM>) of clamp lever latch member (<NUM>), thereby preventing clamp lever latch member (<NUM>) from being actuated to release clamp lever (<NUM>) from cartridge channel (<NUM>). Accordingly, hook element (<NUM>) functions as a safety lockout feature that prevents clamp lever (<NUM>) from be opened unless firing assembly (<NUM>) is in the proximal home position. Advantageously, this feature ensures that stapler halves (<NUM>, <NUM>) cannot be separated from one another while a knife member (<NUM>) (see <FIG>) of stapler (<NUM>) is exposed through an upper deck of staple cartridge (<NUM>) during a firing stroke.

As shown in <FIG>, after stapler (<NUM>) has been fired, firing assembly (<NUM>) is returned to its proximal home position within cartridge channel (<NUM>). As firing assembly (<NUM>) is advanced proximally, the proximal cam ramp of block finger (<NUM>) engages the distal cam ramp of detent finger (<NUM>), thereby driving detent finger (<NUM>) downwardly and rotating detent member (<NUM>) in the counter-clockwise direction against the bias of torsion spring (<NUM>). As firing assembly (<NUM>) reaches the proximal home position shown in <FIG>, block finger (<NUM>) settles within uppercut feature (<NUM>) of detent finger (<NUM>) and block finger (<NUM>) holds detent member (<NUM>) in a slightly counter-clockwise position such that proximal hook element (<NUM>) no longer obstructs upper tip (<NUM>) of clamp lever latch member (<NUM>). Accordingly, clamp lever latch member (<NUM>) may be actuated to disengage cartridge channel (<NUM>) and permit opening of clamp lever (<NUM>) for separation of stapler halves (<NUM>, <NUM>). It will be appreciated that the detent interaction between detent member (<NUM>) and slider block (<NUM>) as described above provides an operator with a tactile indication of when firing assembly (<NUM>) is separated from and returned to its proximal home position, thereby signaling to the operator when it is safe to open clamp lever (<NUM>) and separate stapler halves (<NUM>, <NUM>).

<FIG> show additional details of firing assembly (<NUM>) of linear surgical stapler (<NUM>). As shown best in <FIG>, firing assembly (<NUM>) of the present example includes a slider block (<NUM>), a pair of actuators (<NUM>, <NUM>) (or "firing knobs") pivotably coupled to slider block (<NUM>), and a plurality of elongate beams (<NUM>, <NUM>) extending distally from slider block (<NUM>). A pair of side beams (<NUM>) are coupled at their proximal ends to a distal end of slider block (<NUM>) and terminate distally in a pair of cam ramps (<NUM>). Cam ramps (<NUM>) are configured to actuate staple drivers (not shown) housed within staple cartridge (<NUM>) to fire staples (not shown) from cartridge (<NUM>), in a manner similar to cam ramps (<NUM>) of sled (<NUM>) described above. A center beam (<NUM>) is coupled with side beams (<NUM>) via a bridge element (<NUM>) spaced distally from slider block (<NUM>). Center beam (<NUM>) terminates distally in an angled knife member (<NUM>) having a distal cutting edge (<NUM>) configured to cut tissue clamped between the distal portions of stapler halves (<NUM>, <NUM>). Firing assembly (<NUM>) is operable to be driven distally through cartridge channel (<NUM>) to simultaneously cut and staple tissue clamped between stapler halves (<NUM>, <NUM>), in response to an operator pushing distally on an exposed one of actuators (<NUM>, <NUM>) as described below.

As shown best in <FIG>, actuators (<NUM>, <NUM>) are rotationally coupled to slider block body (<NUM>) with a pivot pin (<NUM>) such that each actuator (<NUM>, <NUM>) extends outwardly from a respective lateral side of block body (<NUM>) and is configured to rotate through a lateral opening (<NUM>) formed in block body (<NUM>). Each actuator (<NUM>, <NUM>) includes an actuator body (<NUM>) and a paddle (<NUM>) extending transversely from an outer end of actuator body (<NUM>), such that actuator bodies (<NUM>) are generally horizontal and paddles (<NUM>) are generally vertical in the orientations depicted herein. As shown in <FIG>, each actuator body (<NUM>) includes a wedge feature (<NUM>) at its inner end that is configured to move through lateral opening (<NUM>) of block body (<NUM>). Wedge features (<NUM>) are configured to abut one another such that each actuator (<NUM>, <NUM>) is configured automatically, rotationally retract relative to slider block (<NUM>) when the opposing actuator (<NUM>, <NUM>) is rotationally exposed by an operator, as described in greater detail below in connection with <FIG>.

As seen best in <FIG> and <FIG>, each actuator body (<NUM>) further includes a detent projection (<NUM>) and a stop tab (<NUM>) projecting downwardly from a lower surface of actuator body (<NUM>). Each detent projection (<NUM>) is configured to slidably engage a respective detent groove (<NUM>) formed in the proximal portion of a respective lateral side of slider block body (<NUM>). Each stop tab (<NUM>) is configured to be received within a recess (<NUM>) formed in the distal portion of a respective lateral side of slider block body (<NUM>). As each actuator (<NUM>, <NUM>) rotates between a retracted rotational positional and an exposed rotational position, its detent projection (<NUM>) slides longitudinally within the respective detent groove (<NUM>). Additionally, as an actuator (<NUM>, <NUM>) is rotated from its exposed rotational position to its retracted rotational position, its stop tab (<NUM>) is received within and abuts an inner side wall of the respective recess (<NUM>).

Actuators (<NUM>, <NUM>) of linear surgical stapler (<NUM>) are configured to enable dual-sided firing of stapler (<NUM>) such that stapler (<NUM>) may be fired by driving an actuator (<NUM>, <NUM>) distally along either lateral side of stapler (<NUM>). Actuators (<NUM>, <NUM>) are further configured such that at least one actuator (<NUM>, <NUM>) remains retracted at all times to prevent an unused actuator (<NUM>, <NUM>) from interfering with an operator's ability to securely grip stapler (<NUM>) with a supporting hand while firing stapler (<NUM>) with a firing hand. As described below, each actuator (<NUM>, <NUM>) of the present version is rotatable relative to slider block (<NUM>) by approximately <NUM> degrees between a retracted rotational position and an exposed rotational position.

<FIG> shows first actuator (<NUM>) in an exposed rotational position in which its paddle (<NUM>) is oriented distally and extends transversely to a longitudinal axis of firing assembly (<NUM>), and second actuator (<NUM>) in a retracted rotational position in which its paddle (<NUM>) is oriented proximally and extends parallel to the longitudinal axis. In this configuration, an operator may grip, with a first hand, the second lateral side of stapler (<NUM>) along which paddle (<NUM>) of second actuator (<NUM>) is retracted, and simultaneously drive with a second hand the exposed paddle (<NUM>) of first actuator (<NUM>) distally to perform a firing stroke.

<FIG> shows actuators (<NUM>, <NUM>) in an opposite orientation achieved by driving paddle (<NUM>) of retracted second actuator (<NUM>) distally to rotate second actuator body (<NUM>) about pin (<NUM>) such that wedge feature (<NUM>) of second actuator (<NUM>) drives against wedge feature (<NUM>) of first actuator (<NUM>). This interaction causes first actuator (<NUM>) to automatically rotate from an exposed rotational position to a retracted rotational position, shown in <FIG>. In this configuration, an operator grips, with a first hand, the first lateral side of stapler (<NUM>) along which paddle (<NUM>) of first actuator (<NUM>) is retracted, and simultaneously drive with a second hand the exposed paddle (<NUM>) of second actuator (<NUM>) distally to perform a firing stroke. It will be appreciated that second actuator (<NUM>) may also automatically rotate from its exposed rotational position to its retracted rotational position in response to rotation of first actuator (<NUM>).

<FIG> shows both actuators (<NUM>, <NUM>) in retracted rotational positions in which both paddles (<NUM>) are oriented proximally such that they extend generally parallel to the longitudinal axis of firing assembly (<NUM>). Such a configuration may provide surgical stapler (<NUM>) with a compact profile suitable for device packaging and other storage or transportation purposes, for example.

As shown in <FIG> and <FIG>, the proximal portion of each longitudinal firing slot (<NUM>) of cartridge channel (<NUM>) is suitably shaped to permit the respective actuator (<NUM>, <NUM>) to rotate between its retracted and exposed positions while firing assembly (<NUM>) is in its proximal home position. Once firing assembly (<NUM>) is actuated distally during a firing stroke, firing slots (<NUM>) prevent actuators (<NUM>, <NUM>) from rotating until firing assembly (<NUM>) is returned to its proximal home position following completion of the firing stroke. For instance, <FIG> shows first actuator (<NUM>) in an exposed position and being driven distally through a respective longitudinal firing slot (<NUM>) such that its stop tab (<NUM>), and subsequently its detent projection (<NUM>), are captured between slider block body (<NUM>) and a confronting inner surface of the respective side flange (<NUM>) of cartridge channel (<NUM>). Accordingly, stop tab (<NUM>) and detent projection (<NUM>) of first actuator (<NUM>) become constrained to prevent unintentional rotation of first actuator (<NUM>) from its exposed position to its retracted position while stapler (<NUM>) is being fired. It will be understood that second actuator (<NUM>) is constrained in a similar manner by slider block body (<NUM>) and the adjacent cartridge channel side flange (<NUM>) when second actuator (<NUM>) is in the exposed position and is being driven distally to fire stapler (<NUM>).

In some instances, it may be desirable to provide linear surgical stapler (<NUM>) with rotatable actuators that are configured to be oriented in exposed rotational positions simultaneously, unlike actuators (<NUM>, <NUM>) described above. The exemplary alternative actuators (<NUM>, <NUM>, <NUM>, <NUM>) described below exhibit such functionality.

<FIG> show another exemplary slider block (<NUM>) and a pair of actuators (<NUM>, <NUM>) (or "firing knobs") suitable for use with linear surgical stapler (<NUM>). Slider block (<NUM>) and actuators (<NUM>, <NUM>) are similar to slider block (<NUM>) and actuators (<NUM>, <NUM>) described above in that actuators (<NUM>, <NUM>) are rotatably coupled with slider block (<NUM>) about a shared vertical pivot axis defined by a pivot pin (<NUM>). Additionally, each actuator (<NUM>, <NUM>) is rotatable by approximately <NUM> degrees between an exposed rotational position and a retracted rotational position to provide dual-sided firing. Each actuator (<NUM>, <NUM>) includes a generally triangular actuator body (<NUM>) having an inner end that is rotatably coupled with slider block (<NUM>) and outer end from which a paddle (<NUM>) extends transversely. Though not shown, slider block (<NUM>) and actuators (<NUM>, <NUM>) may include detent features that provide an operator with a tactile indication of the rotational position of each actuator (<NUM>, <NUM>). In some versions, such detent features may be similar to those of slider block (<NUM>) and actuators (<NUM>, <NUM>) described above. In some versions, such detent features may be supplemented or substituted with other suitable friction-inducing elements, such as o-rings, to enhance tactile feel for an operator.

As shown best in <FIG>, the inner end of each actuator body (<NUM>) includes a plurality of laterally extending, pointed arms (<NUM>) configured to overlap and mesh with similar pointed arms (<NUM>) of the opposing actuator body (<NUM>). Pointed arms (<NUM>) of each actuator (<NUM>, <NUM>) are configured such that when a given actuator (<NUM>, <NUM>) is rotated from an exposed rotational position to a retracted rotational position, its pointed arms (<NUM>) engage the outer end of the opposing actuator body (<NUM>) and automatically rotate the opposing actuator (<NUM>, <NUM>) from a retracted position to an extended position. In other words, in the present example, each actuator (<NUM>, <NUM>) is configured to rotatably drive the opposing actuator (<NUM>, <NUM>) when actuators (<NUM>, <NUM>) are rotationally offset from one another by <NUM> degrees.

<FIG> shows actuators (<NUM>, <NUM>) in an exemplary configuration in which first actuator (<NUM>) is retracted and second actuator (<NUM>) is extended. <FIG> shows actuators (<NUM>, <NUM>) in an opposite configuration in which first actuator (<NUM>) is extended and second actuator (<NUM>) is retracted, which may be achieved from the configuration shown in <FIG> simply by rotating second actuator (<NUM>) from its extended position to its retracted position. <FIG> shows the proximal end of an exemplary linear surgical stapler (<NUM>) that incorporates slider block (<NUM>) and actuators (<NUM>, <NUM>), showing the slider block (<NUM>) in a proximal home position with both actuators (<NUM>, <NUM>) extended, similar to <FIG>. <FIG> shows the proximal end of stapler (<NUM>) with slider block (<NUM>) in the proximal home position with first actuator (<NUM>) retracted and second actuator (<NUM>) extended, similar to <FIG>. <FIG> shows the proximal end of stapler (<NUM>) with slider block (<NUM>) in the proximal home position with first actuator (<NUM>) extended and second actuator (<NUM>) retracted, similar to <FIG>.

<FIG> shows first actuator (<NUM>) in the extended rotational position and in a distal longitudinal position after having been translated distally with slider block (<NUM>) to fire stapler (<NUM>). As shown best in <FIG>, and <FIG>, each actuator (<NUM>, <NUM>) includes a pair of vertically extending projections (<NUM>) arranged at an outer end of actuator body (<NUM>). Vertical projections (<NUM>) of each actuator (<NUM>, <NUM>) are configured to track longitudinally within a respective guide channel (<NUM>) defined between confronting lateral sides of a cartridge channel (<NUM>) and a cartridge half shroud (<NUM>) when slider block (<NUM>) and actuators (<NUM>, <NUM>) are driven distally. This tracking of vertical projections (<NUM>) within guide channels (<NUM>) prevents unintentional rotation of actuators (<NUM>, <NUM>) during a firing stroke. As demonstrated by projections (<NUM>) of first actuator (<NUM>) in <FIG>, projections (<NUM>) are aligned parallel to the longitudinal axis of cartridge channel (<NUM>) when the respective actuator (<NUM>, <NUM>) is in the exposed rotational position, such that both projections (<NUM>) are captured and track within the guide channel (<NUM>). As demonstrated by projections (<NUM>) of second actuator (<NUM>) in <FIG>, only one of the projections (<NUM>) of an actuator (<NUM>, <NUM>) tracks within the respective guide channel (<NUM>) when an actuator (<NUM>, <NUM>) is in the retracted rotational position.

<FIG> shows another exemplary slider block (<NUM>) and a corresponding pair of rotatable actuators (<NUM>, <NUM>) suitable for use with linear surgical stapler (<NUM>). Slider block (<NUM>) and actuators (<NUM>, <NUM>) are similar to slider block (<NUM>) and actuators (<NUM>, <NUM>) described above, except that each actuator (<NUM>, <NUM>) has a rounded inner end (<NUM>) that omits pointed arms (<NUM>). Consequently, rotation of an actuator (<NUM>, <NUM>) from its extended rotational position to its retracted rotational position while the opposing actuator (<NUM>, <NUM>) is retracted does not operate to automatically extend the opposing actuator (<NUM>, <NUM>). Accordingly, unlike actuators (<NUM>, <NUM>), actuators (<NUM>, <NUM>) are configured to both assume a retracted rotational position simultaneously, as exemplified by linear surgical stapler (<NUM>) shown in <FIG>.

In some instances, it may be desirable to configure the firing assembly of a linear surgical stapler such that it includes a slider block that omits proximally extending projections, unlike slider block (<NUM>) of firing assembly (<NUM>) described above. The exemplary alternative linear surgical stapler (<NUM>) described below includes a firing assembly that is configured in such a manner.

<FIG> and <FIG> show the proximal portion of another exemplary linear surgical stapler (<NUM>) having a cartridge half (<NUM>) and an anvil half (<NUM>) configured to be releasably coupled together to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. Stapler (<NUM>) may be generally similar to stapler (<NUM>) described above, except as otherwise described below. Cartridge half (<NUM>) includes an elongate cartridge channel (<NUM>) and a clamp lever (<NUM>) coupled with cartridge channel (<NUM>) and configured to pivot between open and closed positions to clamp stapler halves (<NUM>, <NUM>) together. Cartridge half (<NUM>) further includes, among other features, a firing assembly (<NUM>) and a proximal retaining assembly (<NUM>) supported by a proximal frame portion of cartridge channel (<NUM>). Anvil half (<NUM>) includes, among other features, an elongate anvil channel (<NUM>) and a proximal pin (<NUM>) coupled to a proximal end of anvil channel (<NUM>) and configured to be engaged by proximal retaining assembly (<NUM>) of cartridge half (<NUM>), as described below.

Firing assembly (<NUM>) of linear surgical stapler (<NUM>) is similar to firing assembly (<NUM>) of stapler (<NUM>) in that firing assembly (<NUM>) includes a slider block (<NUM>) and a pair of rotatable actuators (<NUM>) coupled with slider block (<NUM>), with only one actuator (<NUM>) being shown in <FIG>. Similar to actuators (<NUM>, <NUM>), each actuator (<NUM>) is rotatable relative to slider block (<NUM>) between a retracted rotational position and an exposed rotational position. A proximal end of slider block (<NUM>) includes an upwardly extending finger (<NUM>) having rounded proximal and distal ends defining respective proximal and distal cam ramps configured to releasably engage proximal retaining assembly (<NUM>), as described below.

Retaining assembly (<NUM>) of linear surgical stapler (<NUM>) is similar to retaining assembly (<NUM>) of stapler (<NUM>) in that retaining assembly (<NUM>) includes an anvil latch member (<NUM>) configured to releasably couple a proximal end of cartridge half (<NUM>) with a proximal end of anvil half (<NUM>), and a detent member (<NUM>) configured to releasably retain firing assembly (<NUM>) in a proximal home position. Anvil latch member (<NUM>) and detent member (<NUM>) are rotatably coupled with a proximal end of cartridge channel (<NUM>) about a shared rotational axis defined by a laterally extending pivot pin (<NUM>). Additionally, anvil latch member (<NUM>) and detent member (<NUM>) are resiliently biased in opposite rotational directions by a resilient member (not shown) similar to torsion spring (<NUM>). In particular, in the view shown in <FIG>, detent member (<NUM>) is biased in a counter-clockwise direction and anvil latch member (<NUM>) is biased in a clockwise direction. Anvil latch member (<NUM>) includes a latch feature (not shown), which may be similar to latch finger (<NUM>) of anvil latch member (<NUM>), configured to releasably capture proximal pin (<NUM>) of anvil half (<NUM>) to couple anvil half (<NUM>) with cartridge half (<NUM>). Anvil latch member (<NUM>) further includes a proximally extending release button (<NUM>) configured to selectively disengage the latch feature from proximal pin (<NUM>) to permit separation of stapler halves (<NUM>, <NUM>). Detent member (<NUM>) includes a distally extending finger (<NUM>) having a distal tip that tapers downwardly so as to define opposed proximal and distal cam ramps configured to engage slider block finger (<NUM>), as described below.

<FIG> show interactions between slider block (<NUM>) and detent member (<NUM>) during firing of linear surgical stapler (<NUM>). <FIG> shows slider block (<NUM>) in a proximal home position in which detent finger (<NUM>) overlies an upper end of slider block finger (<NUM>). As slider block (<NUM>) is driven distally during a firing stroke, the proximal rounded end of slider block finger (<NUM>) pushes distally on the proximal cam ramp of detent finger (<NUM>), thereby causing detent member (<NUM>) to rotate such that detent finger (<NUM>) moves upwardly, as shown in <FIG>. As slider block (<NUM>) advances further distally, detent finger (<NUM>) disengages slider block finger (<NUM>) and detent member (<NUM>) returns to its original rotational position, as shown in <FIG>. As shown in <FIG>, when slider block (<NUM>) is retracted proximally after stapler (<NUM>) is fired, the rounded proximal end of slider block finger (<NUM>) engages the distal cam surface of detent finger (<NUM>). This causes detent member (<NUM>) to rotate such that detent finger (<NUM>) moves upwardly and receives slider block finger (<NUM>) once again as slider block (<NUM>) returns to the proximal home position shown in <FIG>. Advantageously, the above described detent interaction between detent finger (<NUM>) and slider block finger (<NUM>) provides the operator with a tactile indication of when firing assembly (<NUM>) is advanced distally from and returned proximally to its proximal home position.

As described above, linear surgical stapler (<NUM>) includes a first releasable latching feature in the form of anvil latch member (<NUM>) that releasably couples the proximal end of anvil half (<NUM>) with the proximal end of cartridge half (<NUM>). Stapler (<NUM>) further includes a second releasable latching feature in the form of clamp lever latch member (<NUM>) that releasably maintains clamp lever (<NUM>) in the closed position. Cartridge half (<NUM>) is configured such that release button (<NUM>) of anvil latch member (<NUM>) is concealed by clamp lever (<NUM>) while clamp lever (<NUM>) is in the closed position, thereby preventing unwanted confusion for an operator between anvil release button (<NUM>) and clamp lever latch member (<NUM>) during a surgical procedure. The exemplary linear surgical staplers (<NUM>, <NUM>) described below present alternative configurations that conceal an anvil half release feature when the clamp lever is closed to prevent unwanted confusion between an anvil half release feature and a clamp lever release feature.

<FIG> show an exemplary linear surgical stapler (<NUM>) that is similar to stapler (<NUM>) described above except as otherwise described below. Stapler (<NUM>) includes a cartridge half (<NUM>) and an anvil half (<NUM>) configured to releasably couple together to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. Cartridge half (<NUM>) includes an elongate cartridge channel (<NUM>), a clamp lever (<NUM>) pivotably coupled to cartridge channel (<NUM>), and a firing assembly (<NUM>) slidably supported by cartridge channel (<NUM>). Clamp lever (<NUM>) includes a clamp lever latch member (<NUM>) configured to releasably maintain clamp lever (<NUM>) in the closed position. Clamp lever (<NUM>) includes a clamp lever shroud (<NUM>), and anvil half (<NUM>) includes an anvil shroud (<NUM>).

Cartridge half (<NUM>) further includes, among other features, an anvil latch member (<NUM>) configured to releasably couple a proximal end of cartridge half (<NUM>) with a proximal end of anvil half (<NUM>), similar to anvil latch member (<NUM>) described above. Anvil latch member (<NUM>) includes an anvil release button (<NUM>) exposed through a base wall of cartridge channel (<NUM>). Anvil release button (<NUM>) is actuatable by an operator to disengage anvil latch member (<NUM>) from anvil half (<NUM>) and thereby permit separation of stapler halves (<NUM>, <NUM>). As shown, a proximal end of clamp lever shroud (<NUM>) is suitably shaped to conceal anvil release button (<NUM>) within an interior of shroud (<NUM>) when clamp lever (<NUM>) is in the closed position. Accordingly, an operator is prevented from unintentionally actuating anvil release button (<NUM>) before first actuating clamp lever latch member (<NUM>) to open clamp lever (<NUM>).

<FIG> show another exemplary linear surgical stapler (<NUM>) that is similar to stapler (<NUM>) described above except as otherwise described below. Stapler (<NUM>) includes a cartridge half (<NUM>) and an anvil half (<NUM>) configured to releasably couple together to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. Cartridge half (<NUM>) includes an elongate cartridge channel (<NUM>), a clamp lever (<NUM>) pivotably coupled to cartridge channel (<NUM>), and a firing assembly (<NUM>) slidably supported by cartridge channel (<NUM>). Clamp lever (<NUM>) includes a clamp lever latch member (<NUM>) configured to releasably maintain clamp lever (<NUM>) in the closed position. Clamp lever (<NUM>) includes a clamp lever shroud (<NUM>), and anvil half (<NUM>) includes an anvil shroud (<NUM>). Clamp lever shroud (<NUM>) includes an elongate tab (<NUM>) arranged at a proximal end thereof and extending transversely toward a proximal end of anvil shroud (<NUM>). The proximal end of anvil shroud (<NUM>) includes a cutout (<NUM>) configured to receive a free end of tab (<NUM>) when clamp lever (<NUM>) is closed, as shown in <FIG>.

Cartridge half (<NUM>) further includes, among other features, an anvil latch member (<NUM>) configured to releasably couple a proximal end of cartridge half (<NUM>) with a proximal end of anvil half (<NUM>), similar to anvil latch member (<NUM>). Anvil latch member (<NUM>) includes an anvil release button (<NUM>) exposed through a proximal end of cartridge channel (<NUM>). Anvil release button (<NUM>) is actuatable by an operator to disengage anvil latch member (<NUM>) from anvil half (<NUM>) and thereby permit separation of stapler halves (<NUM>, <NUM>). As shown, proximal tab (<NUM>) of clamp lever shroud (<NUM>) is configured to extend proximally about and thereby conceal anvil release button (<NUM>) when clamp lever (<NUM>) is in the closed position in which tab (<NUM>) is received within anvil shroud cutout (<NUM>). Accordingly, an operator is prevented from unintentionally actuating anvil release button (<NUM>) before first actuating clamp lever latch member (<NUM>) to open clamp lever (<NUM>).

In some versions, staplers (<NUM>, <NUM>) may further include a clamp lever lockout feature (not shown) that prevents release of clamp lever latch member (<NUM>, <NUM>) from cartridge channel (<NUM>, <NUM>) until firing assembly (<NUM>, <NUM>) has been returned to its proximal home position. In some versions, such a lockout feature may be configured similar to proximal hook (<NUM>) of detent member (<NUM>) described above.

In many instances, it is desirable to configure a linear surgical stapler to minimize the input force required by an operator to fire the stapler. The exemplary linear surgical stapler (<NUM>) shown in <FIG> includes a firing assembly (<NUM>) that is fired by pulling an actuator (<NUM>) with a tension force rather than pushing actuator (<NUM>) with a compression force. As described in greater detail below, this "pull-to-fire" configuration provides enhanced mechanical advantage while maintaining dual-sided firing capability.

Linear surgical stapler (<NUM>) is similar to stapler (<NUM>) in that stapler (<NUM>) includes a cartridge half (<NUM>) and an anvil half (<NUM>) configured to releasably couple together to clamp tissue therebetween and simultaneously cut and staple the clamped tissue. Cartridge half (<NUM>) includes a firing assembly (<NUM>) having an actuator (<NUM>) (or "firing knob") arranged at the proximal end of stapler (<NUM>) and secured to the proximal end of an elongate drive beam (<NUM>). Drive beam (<NUM>) extends distally into cartridge half (<NUM>) and is in the form of a rack having a plurality of gear teeth (not shown) arranged on an underside thereof. Firing assembly (<NUM>) further includes an elongate firing beam (<NUM>) extending distally through cartridge half (<NUM>) and terminating at a distal knife member (<NUM>) configured to translate through a staple cartridge (<NUM>) to cut tissue. A proximal portion of firing beam (<NUM>) comprises a rack (<NUM>) having a plurality of gear teeth (not shown) arranged on an upper side thereof. Though not shown, firing beam (<NUM>) may further include one or more additional structures that provide cam ramps configured to actuate staple pushers (not shown) of staple cartridge (<NUM>), similar to side beams (<NUM>) and cam ramps (<NUM>) of stapler (<NUM>), for example.

Drive rack (<NUM>) and knife rack (<NUM>) are operatively coupled with one another via a compound pinion gear (<NUM>) rotatably mounted within cartridge half (<NUM>). Compound pinion gear (<NUM>) includes an outer gear portion (<NUM>) having a first diameter, and an inner gear portion (<NUM>) provided concentrically on a lateral face of outer gear portion (<NUM>) and having a smaller second diameter. Compound pinion gear (<NUM>) is mounted within cartridge half (<NUM>) such that outer gear portion engages drive rack (<NUM>) and inner gear portion (<NUM>) simultaneously engages knife rack (<NUM>), and such that pinion gear (<NUM>) is configured to rotate about an axis that extends transversely to a longitudinal axis of stapler (<NUM>).

To fire stapler (<NUM>), actuator (<NUM>) is pulled proximally by an operator from a distal home position to thereby translate drive rack (<NUM>) proximally. This causes compound pinion gear (<NUM>) to rotate in a first direction (e.g., counter-clockwise in the view of <FIG>), which drives firing beam (<NUM>) distally such that knife member (<NUM>) and cam ramps (not shown) are driven distally through staple cartridge (<NUM>) to thereby simultaneously cut and staple tissue clamped between stapler halves (<NUM>, <NUM>). After reaching its fully proximal position, actuator (<NUM>) is then pushed distally to rotate compound pinion gear (<NUM>) in an opposite second direction (e.g., clockwise in the view of <FIG>) and thereby retract firing beam (<NUM>) proximally to its home position.

The power transmission between racks (<NUM>, <NUM>) and compound pinion gear (<NUM>) described above yields an output force at knife member (<NUM>) that is greater than the input force exerted on actuator (<NUM>) by the operator, thereby providing firing assembly (<NUM>) with mechanical advantage. It will be appreciated that outer and inner gear portions (<NUM>, <NUM>) of compound pinion gear (<NUM>) may be suitably sized to provide firing assembly (<NUM>) with any desired degree of mechanical advantage during operation.

As described above in connection linear surgical stapler (<NUM>), distal jaw portion (<NUM>) of anvil channel (<NUM>) supports an anvil surface (<NUM>) that provides a plurality of staple forming pockets. In some instances, it may be desirable to form anvil surface (<NUM>) separately from anvil channel (<NUM>) in the form of an anvil plate, and then rigidly attach the anvil plate to distal jaw portion (<NUM>). <FIG> show exemplary variations of such a process.

<FIG> show an anvil channel (<NUM>) having a distal jaw portion (<NUM>), and an anvil surface in the form of an anvil plate (<NUM>) formed separately from anvil channel (<NUM>). Anvil channel (<NUM>) may be similar to anvil channel (<NUM>) described above, and anvil channel (<NUM>) and anvil plate (<NUM>) are suitable for use with linear surgical stapler (<NUM>). Anvil plate (<NUM>) includes a plurality of staple forming pockets (<NUM>) and a longitudinal knife slot (<NUM>) configured to slidably receive a knife member (not shown) therethrough, which may be similar to knife member (<NUM>) described above. The features of anvil plate (<NUM>), including staple forming pockets (<NUM>) and longitudinal knife slot (<NUM>) may be formed via any one or more suitable machining processes, such as electrochemical machining (ECM) and/or coining, for example.

As shown in <FIG>, after at least staple forming pockets (<NUM>) have been formed in anvil plate (<NUM>), a bottom surface of anvil plate (<NUM>) is aligned with and lowered onto side rails (<NUM>) of distal jaw portion (<NUM>) of anvil channel (<NUM>). Anvil plate (<NUM>) may be provided with one or more fiducial features during its machining process that aid in alignment of anvil plate (<NUM>) with anvil channel side rails (<NUM>). Such fiducial features may be in the form of, or alternatively may be provided in addition to, existing features of anvil plate (<NUM>). For instance, in some versions such fiducial features may comprise one or more of the bottom surface of anvil plate (<NUM>), longitudinal knife slot (<NUM>) or a select portion(s) of knife slot (<NUM>), or a proximal edge of anvil plate (<NUM>).

Once anvil plate (<NUM>) is mounted to distal side rails (<NUM>) of anvil channel (<NUM>), anvil plate (<NUM>) is securely attached to side rails (<NUM>). <FIG> shows a first exemplary attachment method in which each lateral edge of anvil plate (<NUM>) is secured to the respective anvil channel side rail (<NUM>) with a plurality of spot welds (<NUM>) spaced longitudinally from one another. <FIG> shows a second exemplary attachment method in which each lateral edge of anvil plate (<NUM>) is secured to the respective anvil channel side rail (<NUM>) with a seam weld (<NUM>) that extends longitudinally for substantially a full length of anvil plate (<NUM>). In other versions, a plurality of shorter seam welds (<NUM>) may be provided along each lateral edge of anvil plate (<NUM>), or a combination of spot welds (<NUM>) and seam welds (<NUM>) may be provided. Furthermore, longitudinal knife slot (<NUM>) may be formed in anvil plate (<NUM>) before or after attachment of anvil plate (<NUM>) to anvil channel (<NUM>). It will be appreciated that forming pockets (<NUM>) in anvil plate (<NUM>) before anvil plate (<NUM>) is attached to anvil channel (<NUM>) advantageously reduces the size of the component being handled during the pocket formation process, thereby simplifying and reducing costs for manufacturing of the anvil half of a respective linear surgical stapler.

Further, any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the teachings, expressions, embodiments, examples, etc. described in<CIT>, entitled "Release Mechanism for Linear Surgical Stapler"; <CIT>, entitled "Lockout Assembly for Linear Surgical Stapler"; <CIT>, entitled "Features to Align and Close Linear Surgical Stapler"; <CIT>, entitled "Releasable Coupling Features for Proximal Portions of Linear Surgical Stapler"; <CIT>, entitled "Firing Lever Assembly for Linear Surgical Stapler"; and/or <CIT>, entitled "Clamping Mechanism for Linear Surgical Stapler".

Claim 1:
A surgical stapler (<NUM>) comprising:
(a) a first elongate member (<NUM>) having a distal portion (<NUM>) that supports an anvil surface (<NUM>), wherein the anvil surface (<NUM>) includes a plurality of staple forming pockets;
(b) a second elongate member (<NUM>) having a distal portion (<NUM>) configured to receive a staple cartridge (<NUM>);
(c) a clamp member (<NUM>) operable to releasably clamp the first elongate member (<NUM>) against the second elongate member (<NUM>);
(c) a firing assembly (<NUM>), wherein the firing assembly (<NUM>) is translatable from a first longitudinal position to a second longitudinal position to fire the staple cartridge (<NUM>) when the first elongate member (<NUM>) is clamped against the second elongate member (<NUM>); and
(d) a retaining assembly (<NUM>), wherein the retaining assembly (<NUM>) comprises:
(i) a first retaining member (<NUM>) configured to releasably couple a proximal end of the first elongate member (<NUM>) with a proximal end of the second elongate member (<NUM>), and
(ii) a second retaining member (<NUM>) configured to releasably retain the firing assembly (<NUM>) in the first longitudinal position, wherein
characterized in that: the first retaining member (<NUM>) comprises a latch member, wherein the second retaining member (<NUM>) comprises a detent member, wherein the clamp member (<NUM>) is moveable from an unclamped position to a clamped position to clamp the first elongate member (<NUM>) against the second elongate member (<NUM>), wherein the detent member (<NUM>) is configured to prevent the clamp member (<NUM>) from returning to the unclamped position from the clamped position when the firing assembly (<NUM>) is advanced longitudinally away from its first longitudinal position.