Patent Description:
Merely exemplary surgical staplers are disclosed in <CIT>; <CIT>; <CIT>, <CIT>; <CIT>; and <CIT>. Additional merely exemplary surgical staplers are disclosed in <CIT>; <CIT>; and <CIT>.

<CIT> discloses a surgical staple including a crown and a deformable member extending from the crown, the deformable member having a notch configured to cause the deformable member to bend at the notch when the staple is deformed from a first shape into a second shape.

<CIT> discloses a method for manipulating tissue of a patient including a surgical instrument having a handle assembly, a shaft assembly, and an end effector.

A surgical stapler may be inserted into a patient to perform colorectal surgery. Such procedures may include the use of the stapler to operatively seal, sever, and remove the colon of the patient, in whole or in part. For instance, a proctocolectomy may be performed during a lower anterior resection ("LAR") for treating and inhibiting the spread of colorectal cancer cells. Of course, surgical staplers may be used in various other settings and procedures.

For clarity of disclosure, the terms "proximal" and "distal" are defined herein relative to a human or robotic operator of the surgical instrument. The term "proximal" refers the position of an element closer to the human or robotic operator of the surgical instrument and further away from the surgical end effector of the surgical instrument. The term "distal" refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the human or robotic operator of the surgical instrument. It will be further appreciated that for convenience and clarity, spatial terms such as "vertical," "horizontal," "lower," "upper," "front," and "rear" are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

As used herein, the terms "about," "approximately," and the like in connection with any numerical values or ranges of values are intended to encompass the exact value(s) referenced, as well as a suitable dimensional tolerance that enables the referenced feature or combination of features to function for the intended purpose described herein.

<FIG> depict an exemplary surgical stapler (<NUM>) that includes a handle assembly (<NUM>), a shaft assembly (<NUM>) extending distally from handle assembly (<NUM>), and an end effector (<NUM>) at a distal end of shaft assembly (<NUM>). It should be understood that terms such as "proximal," "distal," "right," and "left" are used herein with reference to a clinician gripping handle assembly (<NUM>) of surgical stapler (<NUM>). Thus, end effector (<NUM>) is distal with respect to the relatively proximal handle assembly (<NUM>). Except as otherwise described herein, surgical stapler (<NUM>) may be configured and operable in accordance with at least some of the teachings of <CIT>, and/or <CIT>.

Handle assembly (<NUM>) includes several actuation mechanisms for operating end effector (<NUM>) during the surgical procedure. To this end, exemplary handle assembly (<NUM>) includes a saddle shaped slide (<NUM>), a closure trigger (<NUM>), and a firing trigger (<NUM>) in communication with end effector (<NUM>) via shaft assembly (<NUM>). <FIG> shows slide (<NUM>) and closure trigger (<NUM>) in open configurations such that end effector (<NUM>) is configured to receive tissue laterally within a gap (<NUM>) of a replaceable cartridge unit (<NUM>) mounted within end effector (<NUM>), between an anvil (<NUM>) and a cartridge housing (<NUM>) of cartridge unit (<NUM>). As described in greater detail below, translating slide (<NUM>) distally toward end effector (<NUM>) slides a retaining pin (<NUM>) of end effector (<NUM>) distally, as shown in <FIG>, for capturing the tissue between anvil (<NUM>) and cartridge housing (<NUM>). As shown in <FIG> and <FIG>, sequentially actuating closure trigger (<NUM>) and firing trigger (<NUM>) respectively compresses the tissue between anvil (<NUM>) and cartridge housing (<NUM>) in a closed configuration, and then forms a plurality of staples (not shown) within the tissue and severs the tissue with a curved knife (<NUM>) (see <FIG>).

As shown in <FIG>, handle assembly (<NUM>) of surgical stapler (<NUM>) includes a handle housing (<NUM>) and a pair of handle frame plates (<NUM>, <NUM>) having proximal portions (not shown) housed within handle housing (<NUM>) and elongate distal portions that extend distally along shaft assembly (<NUM>). As briefly described above, handle assembly (<NUM>) further includes saddle shaped slide (<NUM>), closure trigger (<NUM>), and firing trigger (<NUM>). Handle housing (<NUM>) defines a hand grip (<NUM>), which the operator may grasp with the palm of at least one hand. Handle housing (<NUM>) of the present example is formed by a right shroud handle portion (<NUM>) and a left shroud handle portion (<NUM>). Closure trigger (<NUM>) is proximally positioned relative to firing trigger (<NUM>), and each trigger (<NUM>, <NUM>) is pivotally mounted to frame plates (<NUM>, <NUM>) and are exposed through an underside of handle housing (<NUM>) to be manipulated by the fingers of the operator. <FIG> shows closure and firing triggers (<NUM>, <NUM>) in unactuated positions prior to the closing of end effector (<NUM>) and firing of staples (not shown) and curved knife (<NUM>). Accordingly, cartridge housing (<NUM>) is spaced proximally from anvil (<NUM>) for receiving tissue within gap (<NUM>) therebetween.

Surgical stapler (<NUM>) is operable to capture tissue via a tissue retaining pin actuation mechanism (<NUM>) prior to actuation of the closure and firing triggers (<NUM>, <NUM>). Tissue retaining pin actuation mechanism (<NUM>) includes slide (<NUM>) of handle assembly (<NUM>), a tissue retaining pin (<NUM>) of end effector (<NUM>), and an elongate pushrod (<NUM>) of shaft assembly (<NUM>). Slide (<NUM>) is mounted on an upper surface of handle housing (<NUM>) and is configured to linearly translate between proximal and distal positions. Pushrod (<NUM>) operatively couples slide (<NUM>) with tissue retaining pin (<NUM>), such that longitudinal translation of slide (<NUM>) drives longitudinal actuation of tissue retaining pin (<NUM>) between a proximal open position (see <FIG>) and a distal closed position (see <FIG>), via pushrod (<NUM>).

A closure mechanism (<NUM>) of surgical stapler (<NUM>) is configured to selectively actuate cartridge housing (<NUM>) of cartridge unit (<NUM>) between a proximal open position (<FIG>) and a distal closed position (<FIG>) for clamping tissue between cartridge housing (<NUM>) and anvil (<NUM>). Closure mechanism (<NUM>) includes closure trigger (<NUM>) of handle assembly (<NUM>) and an elongate closure member (<NUM>) coupled at its proximal end with closure trigger (<NUM>). Closure member (<NUM>) has a generally U-shaped cross-section and extends distally from handle assembly (<NUM>), through shaft assembly (<NUM>), and into end effector (<NUM>), such that a distal end of closure member (<NUM>) is configured to receive cartridge unit (<NUM>) within end effector (<NUM>), as shown in <FIG>. A proximal end of closure member (<NUM>) is operatively connected with closure trigger (<NUM>) by a plurality of linkages (not shown) configured to convert pivoting motion of closure trigger (<NUM>) into translation of closure member (<NUM>). Accordingly, pivoting of closure trigger (<NUM>) toward pistol grip (<NUM>) to a closed position (<FIG>) drives closure member (<NUM>) distally, which in turn drives cartridge housing (<NUM>) distally toward anvil (<NUM>) for clamping tissue therebetween. Subsequently, pivoting of closure trigger (<NUM>) away from pistol grip (<NUM>) to an open position (<FIG>) drives closure member (<NUM>) proximally, which in turn drives cartridge housing (<NUM>) proximally away from anvil (<NUM>) for releasing stapled tissue.

In some versions, closure member (<NUM>) may be further configured to cooperate with tissue retaining pin actuation mechanism (<NUM>) to automatically actuate retaining pin (<NUM>) distally to its closed position when the operator squeezes closure trigger (<NUM>). Such automation may be useful in the event that the operator did not manually actuate retaining pin (<NUM>) distally via slide (<NUM>) prior to squeezing closure trigger (<NUM>). Closure trigger (<NUM>) may be biased toward the open position by a resilient member (not shown) housed within handle housing (<NUM>).

A firing mechanism (<NUM>) of surgical stapler (<NUM>) is configured to actuate end effector (<NUM>) to staple and sever tissue clamped between anvil (<NUM>) and cartridge housing (<NUM>) in response to manipulation of firing trigger (<NUM>) of handle assembly (<NUM>). In that regard, firing mechanism (<NUM>) includes firing trigger (<NUM>), cartridge unit (<NUM>), and an elongate firing bar (not shown) that extends longitudinally through shaft assembly (<NUM>) and operatively couples firing trigger (<NUM>) with cartridge unit (<NUM>). Firing trigger (<NUM>) is positioned distally of closure trigger (<NUM>) such that firing trigger (<NUM>) may be pivoted closed only once closure trigger (<NUM>) has first been pivoted closed. Pivoting of firing trigger (<NUM>) from an open position (<FIG>) toward a closed (or "fired") position (<FIG>) drives the firing bar distally, which in turn drives internal components of cartridge housing (<NUM>) distally to thereby staple and sever the tissue clamped by end effector (<NUM>), as described in greater detail below.

One or both of closure trigger (<NUM>) and firing trigger (<NUM>) may be configured to releasably lock in one or more pivot positions, such as a fully closed position and/or one or more intermediate positions between fully open (i.e., unactuated) and fully closed (i.e., fully actuated), for example. Accordingly, and advantageously, the operator may release one or more hands from the trigger (<NUM>, <NUM>) and hand grip (<NUM>) to perform another task during the surgical procedure, while the trigger (<NUM>, <NUM>) maintains its position. The operator may then release the trigger (<NUM>, <NUM>) from its locked state by depressing a release button (<NUM>) arranged on a proximal end of handle assembly (<NUM>).

Though not shown, shaft assembly (<NUM>) of surgical stapler (<NUM>) may include various additional components, such as an articulating joint, or may include a rearrangement of various components such that shaft assembly (<NUM>) may be modular relative to handle assembly (<NUM>).

As shown best in <FIG>, end effector (<NUM>) of the present example includes a C-shaped support structure (<NUM>) and replaceable cartridge unit (<NUM>) removably received by C-shaped support structure (<NUM>). The support structure (<NUM>) includes a proximal base portion (<NUM>), a medial arm (<NUM>) that extends distally from proximal base portion (<NUM>), and a distal arm (<NUM>) that projects laterally (e.g., upwardly) from a distal end of medial arm (<NUM>). Proximal base portion (<NUM>) is secured to the distal end of handle frame plates (<NUM>, <NUM>) at the distal end of shaft assembly (<NUM>) by a shoulder rivet (<NUM>) and a pair of posts (<NUM>). Distal arm (<NUM>) includes a fixed end (<NUM>) secured to medial arm (<NUM>), and a free end (<NUM>). Proximal base portion (<NUM>) is configured to releasably receive and support cartridge housing (<NUM>), and distal arm (<NUM>) is configured to releasably receive and support anvil (<NUM>) and washer (<NUM>).

The term "C-shaped" is used herein as reference to the curvature of support structure (<NUM>) and cartridge unit (<NUM>), each of which has a concave first lateral side and a convex second lateral side opposed from one another. In other words, support structure (<NUM>) and each component of cartridge unit (<NUM>) extends along a respective arcuate path in a respective plane that is orthogonal to and intersected by the longitudinal shaft axis (LAS). Such a configuration provides enhanced functionality and access to tissue within the patient. By way of example only, the C-shaped construction of support structure (<NUM>) and cartridge unit (<NUM>) may enable end effector (<NUM>) to easily access the lower colon within the pelvic bowl of a patient, for example for performing a lower anterior resection ("LAR") in a proctocolectomy procedure. Accordingly, the term "C-shaped" as used herein should be construed to include a variety of concave shapes that would similarly enhance the functionality of surgical stapling and cutting instruments. In other versions, cartridge unit (<NUM>) and support structure (<NUM>) may be shaped in various other curved and non-curved manners. For instance, cartridge unit (<NUM>) and support structure (<NUM>) may be formed shaped with a linear configuration, for example as described in <CIT>.

Replaceable cartridge unit (<NUM>) includes anvil (<NUM>) and cartridge housing (<NUM>), movably coupled to one another by a guide pin (<NUM>) and an anvil arm (<NUM>), as described in greater detail below. A distal end of cartridge housing (<NUM>) defines a distally facing staple deck (<NUM>) configured to contact tissue. Staple deck (<NUM>) includes a plurality of staple openings (<NUM>) arranged in staggered formation in a pair of rows on each side of an arcuate knife slot (<NUM>). Various other quantities of rows of staple openings (<NUM>) may be provided in other versions. Cartridge housing (<NUM>) houses a plurality of staples (not shown) configured to be driven distally through staple openings (<NUM>) and against anvil (<NUM>) to thereby form the staples in patient tissues. Though not shown, cartridge unit (<NUM>) may further include a retainer configured to removable couple to staple deck (<NUM>) to cover staple openings (<NUM>) and knife slot (<NUM>) before use of cartridge unit (<NUM>), for instance when cartridge unit (<NUM>) is stored, and optionally also after use of cartridge unit (<NUM>).

As shown in <FIG>, cartridge housing (<NUM>) additionally houses retaining pin (<NUM>), a staple driver assembly (<NUM>), and a knife holder (<NUM>). Staple driver assembly (<NUM>) is positioned just proximally of the staples (not shown) housed within cartridge housing (<NUM>) and distally of knife holder (<NUM>). Staple driver assembly (<NUM>) of the present example is formed as a unitary structure defining a plurality of staple drivers (<NUM>). Thus, the term "assembly," as used in connection with staple driver assembly (<NUM>), is not intended to be limited to an assembly of individual components, but may also include integrally formed components with unitary structures. Driver assembly (<NUM>) is configured to translate distally within cartridge housing (<NUM>) so that staple drivers (<NUM>) drive staples distally from respective staple openings (<NUM>) and toward anvil (<NUM>) for formation within tissue clamped between anvil (<NUM>) and cartridge housing (<NUM>).

Knife holder (<NUM>) is movably disposed within cartridge housing (<NUM>) just proximally of staple driver assembly (<NUM>). Knife holder (<NUM>) supports curved knife (<NUM>) along a distal side thereof, and knife holder (<NUM>) is configured to translate within cartridge housing (<NUM>) such that curved knife (<NUM>) extends distally through an arcuate slot (<NUM>) of driver assembly (<NUM>) and arcuate slot (<NUM>) of staple deck (<NUM>). A proximal side of knife holder (<NUM>) includes a slot (<NUM>) and a ledge (<NUM>) configured to couple with a knife retractor hook (not shown) for retraction of curved knife (<NUM>) after firing of cartridge unit (<NUM>), for example as disclosed in <CIT>.

As shown in <FIG>, cartridge housing (<NUM>) includes two longitudinally extending, generally circular holes (<NUM>, <NUM>) at respective upper and lower ends of arcuate knife slot (<NUM>) on staple deck (<NUM>). Holes (<NUM>, <NUM>) of the present example are positioned such that staple openings (<NUM>), and the staples ejected therefrom, extend beyond holes (<NUM>, <NUM>) at the upper and lower ends of staple deck (<NUM>). Lower hole (<NUM>) is shaped and dimensioned to slidably receive a guide pin (<NUM>) that extends longitudinally between cartridge housing (<NUM>) and anvil (<NUM>). Upper hole (<NUM>) is shaped and dimensioned to slidably receive retaining pin (<NUM>) therethrough, such that retaining pin (<NUM>) may actuate longitudinally relative to cartridge housing (<NUM>) and anvil (<NUM>) between the proximal retracted position (<FIG>) and the distal extended position (<FIG>).

As shown in <FIG>, a lateral side of cartridge housing (<NUM>) includes a longitudinally extending detent slot (<NUM>) defined between a confronting pair of resilient members. A first side of detent slot (<NUM>) includes a first proximal detent protrusion (<NUM>), and an opposed second side of detent slot (<NUM>) includes a second proximal detent protrusion (<NUM>) and a distal detent protrusion (<NUM>). Detent slot (<NUM>) is configured to slidably receive a detent post (<NUM>) of knife holder (<NUM>) and a detent post (<NUM>) of staple driver assembly (<NUM>). As staple driver assembly (<NUM>) and knife holder (<NUM>) translate distally within cartridge housing (<NUM>), detent post (<NUM>) resiliently engages detent protrusion (<NUM>), and detent post (<NUM>) resiliently engages detent protrusions (<NUM>, <NUM>).

As shown in <FIG>, a proximal end of retaining pin (<NUM>) includes a first coupling feature (<NUM>) (e.g., a projection) configured to couple with a corresponding coupling feature (not shown) (e.g., a groove) of a couplet (<NUM>), so that retaining pin (<NUM>) is secured to couplet (<NUM>). Couplet (<NUM>) and retaining pin (<NUM>) are slidably disposed within an upper arm (<NUM>) of cartridge housing (<NUM>), and are captured proximally therein by an end cap (<NUM>) secured to upper arm (<NUM>) proximally of couplet (<NUM>). A distal end of pushrod (<NUM>) of tissue retaining pin actuation mechanism (<NUM>), described above, is operatively coupled with couplet (<NUM>). Accordingly, longitudinal actuation of pushrod (<NUM>) via slide (<NUM>) of handle assembly (<NUM>) drives couplet (<NUM>) and thus retaining pin (<NUM>) longitudinally relative to cartridge housing (<NUM>) for capturing tissue to be stapled by end effector (<NUM>).

Anvil (<NUM>) of the present example includes a plate portion (<NUM>), which is secured to a proximal side of an anvil plate backing member in the form of a plastic cutting washer (<NUM>). Anvil plate portion (<NUM>) includes an elongate arcuate slot (<NUM>) configured to receive a cutting feature of cutting washer (<NUM>) in the form of an arcuate projection (<NUM>) therethrough to anvil plate portion (<NUM>) relative to cutting washer (<NUM>). As shown best in <FIG>, anvil plate portion (<NUM>) further includes a plurality of pockets arranged in rows along either side of arcuate slot (<NUM>). These pockets are configured to receive and form the legs of staples (not shown) driven distally from staple openings (<NUM>) of staple deck (<NUM>). Accordingly, anvil (<NUM>) is spaced distally from and is aligned with staple deck (<NUM>) such that each pocket of anvil plate portion (<NUM>) aligns with a respective staple opening (<NUM>).

Anvil plate portion (<NUM>) further includes a first circular opening (<NUM>) disposed at an upper end of arcuate slot (<NUM>), and a second circular opening (see <FIG>) disposed at a lower end of arcuate slot (<NUM>). First opening (<NUM>) is configured to slidably receive a pointed distal tip of tissue retaining pin (<NUM>) when tissue retaining pin (<NUM>) is actuated distally to capture tissue positioned between anvil (<NUM>) and cartridge housing (<NUM>). The lower second opening of anvil plate portion (<NUM>) receives a distal end (<NUM>) of guide pin (<NUM>) therethrough, which extends into and fixedly couples to a lower end of cutting washer (<NUM>), such that guide pin (<NUM>) is longitudinally fixed relative to anvil (<NUM>).

A proximal end (<NUM>) of guide pin (<NUM>) is slidably received through lower hole (<NUM>) formed in staple deck (<NUM>) of cartridge housing (<NUM>), as described above. An anvil arm (<NUM>) projecting proximally from a lower end of anvil plate portion (<NUM>) is movably received through an open lower end of cartridge housing (<NUM>) to thereby trap proximal end (<NUM>) of guide pin (<NUM>) within cartridge housing (<NUM>), while still permitting cartridge housing (<NUM>) to actuate toward anvil (<NUM>). Accordingly, cartridge housing (<NUM>) is configured to slide longitudinally along guide pin (<NUM>) (and tissue retaining pin (<NUM>)) relative to anvil (<NUM>) in response to actuation of closure trigger (<NUM>), described above. As shown in <FIG>, an interior side of guide pin (<NUM>) includes a longitudinal slot (<NUM>) configured to slidably receive a corresponding lower end (<NUM>) of curved knife (<NUM>) as cartridge housing (<NUM>) actuates longitudinally relative to anvil (<NUM>). An interior side of tissue retaining pin (<NUM>) may include a similar longitudinal slot (not shown) configured to slidably receive a corresponding upper end (<NUM>) of curved knife (<NUM>) as cartridge housing (<NUM>) actuates longitudinally relative to anvil (<NUM>).

Having described various structural features of surgical stapler (<NUM>) above, including cartridge unit (<NUM>), exemplary actuation of surgical stapler (<NUM>) during a surgical procedure will now be described below. Surgical stapler (<NUM>) is first suitably manipulated within a body cavity of a patient to position patient tissue within gap (<NUM>) (see <FIG>) between anvil (<NUM>) and cartridge housing (<NUM>). As shown in <FIG>, slide (<NUM>) is then actuated distally to drive pushrod (<NUM>) distally, thereby driving tissue retaining pin (<NUM>) distally from cartridge housing (<NUM>) toward anvil (<NUM>). The pointed distal tip of tissue retaining pin (<NUM>) securely engages (e.g., pierces) the tissue and thereby captures the tissue within gap (<NUM>).

As shown in <FIG>, closure trigger (<NUM>) is then squeezed toward pistol grip (<NUM>) to drive closure member (<NUM>) distally, thereby driving cartridge housing (<NUM>) distally toward anvil (<NUM>) along tissue retaining pin (<NUM>) and guide pin (<NUM>) to clamp the tissue between cartridge deck (<NUM>) and anvil (<NUM>). Cartridge housing (<NUM>) may be maintained in this closed position relative to anvil (<NUM>) by an internal locking mechanism (not shown) of handle assembly (<NUM>) that holds closure trigger (<NUM>) in the squeezed position, as described above. As shown in <FIG>, while cartridge unit (<NUM>) remains in this closed position, firing trigger (<NUM>) is then squeezed toward closure trigger (<NUM>) and pistol grip (<NUM>) to drive the elongate firing bar (not shown) distally, thereby driving staple driver assembly (<NUM>) and knife holder (<NUM>) distally within cartridge housing (<NUM>). Stapler drivers (<NUM>) of driver assembly (<NUM>) drive staples (not shown) distally through the captured tissue and against anvil plate portion (<NUM>) of anvil (<NUM>) to form the staples within the tissue and thereby fluidly seal the tissue. As the staples are being formed, curved knife (<NUM>) is driven distally by knife holder (<NUM>) through arcuate slots (<NUM>, <NUM>), through the clamped tissue, and against arcuate projection (<NUM>) (see <FIG>) of cutting washer (<NUM>), thereby severing the clamped tissue along an arcuate path (AP) extending between the two innermost rows of the formed staples. Upon cutting fully through the clamped tissue, curved knife (<NUM>) may penetrate distally into the arcuate projection (<NUM>) of cutting washer (<NUM>). Optionally, in response to such penetration, a body of cutting washer (<NUM>) may fracture along the distal cutting edge of curved knife (<NUM>), thereby providing an audible indication (e.g., via a "snapping" sound) to the surgeon that the firing stroke is complete and that the clamped tissue has been fully stapled and severed.

Similar to closure trigger (<NUM>), firing trigger (<NUM>) may be held in its squeezed position by the internal locking mechanism (not shown) of handle assembly (<NUM>). It will be appreciated that surgical stapler (<NUM>) may be configured in some versions such that the tissue clamped by end effector (<NUM>) within gap (<NUM>) is stapled and cut simultaneously; and be alternatively configured in other versions such that the tissue is fully stapled and subsequently cut in sequential steps.

Once surgical stapler (<NUM>) has been fully fired into the patient tissue as described above, the operator may depress release button (<NUM>) of handle assembly (<NUM>) to release firing trigger (<NUM>) and closure trigger (<NUM>) from their squeezed positions. In this manner, curved knife (<NUM>) may be retracted proximally back into cartridge housing (<NUM>), and cartridge housing (<NUM>) may be retracted proximally along pins (<NUM>, <NUM>) to thereby release the newly stapled and severed tissue from between anvil (<NUM>) and cartridge deck (<NUM>). The fired cartridge unit (<NUM>) may then be removed from support structure (<NUM>) of end effector (<NUM>), discarded, and replaced for further treatment if so desired.

Surgical stapler (<NUM>) may be further configured and operable in accordance with any of the teachings of the references cited herein.

As described above, support structure (<NUM>) supports and provides rigidity to cartridge unit (<NUM>) to define end effector (<NUM>). However, in some instances, the free end (<NUM>) of support structure distal arm (<NUM>) may pivotally deflect in a distal direction about the attached end (<NUM>), similar to a cantilever, in response to distally-directed tissue compression and firing forces exerted by cartridge housing (<NUM>) and knife (<NUM>). In such instances, the staples may be formed with a proper height (i.e., in a distal direction) at the attached end (<NUM>) because the attached end (<NUM>) does not deflect distally. However, staples may be formed with increasingly greater staple heights in a direction toward free end (<NUM>) due to the distal deflection of free end (<NUM>) relative to fixed end (<NUM>). Accordingly, the resulting heights of formed staples along the arcuate length of staple deck (<NUM>) and anvil plate portion (<NUM>) may be relatively non-uniform, particularly in instances when tissue thickness varies along this arcuate length. The larger-height formed staples in the region of free end (<NUM>) may be incapable of proving effective hemostasis in the corresponding region of tissue.

In addition to or in place of such distal cantilever deflection of free end (<NUM>) of distal arm (<NUM>), a portion of distal arm (<NUM>) inward of free end (<NUM>) (i.e., in a direction toward attached end (<NUM>)) may deflect proximally in response to closure and/or firing of end effector (<NUM>). In some instances, such proximal deflection may be a result of three-point bending effects resulting from the interaction between tissue gap setting protrusions disposed at the inner and/or outer ends of washer (<NUM>) and/or anvil plate portion (<NUM>), and at the inner and/or outer ends of staple deck (<NUM>). Such proximal deflection of a portion of distal arm (<NUM>) may also undesirably result in non-uniformity of formed staple heights.

Accordingly, it may be desirable to provide end effector (<NUM>) with one or more features that mitigate or otherwise compensate for this deflection of support structure distal arm (<NUM>) and thereby promote formation of staples with a uniform staple height along the arcuate length of end effector (<NUM>). As described in greater detail below, end effector (<NUM>) may include a recess that is defined by a concave surface of the end effector (<NUM>). This recess allows a portion of the anvil (<NUM>) and/or cutting washer (<NUM>) to distally deflect relative to adjacent components of end effector (<NUM>) when stapler (<NUM>) is fired. Such a configuration may mitigate and compensate for deflection of distal arm (<NUM>) to thereby minimize variations in staple height across the arcuate length of the staple deck (<NUM>) and anvil plate portion (<NUM>), thus providing improved hemostasis by the formed staples.

<FIG> shows an exemplary configuration in which cutting washer (<NUM>) includes a concave proximal surface (<NUM>) that allows the anvil plate portion (<NUM>) to deflect distally relative to cutting washer (<NUM>) during firing of the end effector (<NUM>), thereby creating more uniform staple heights. Cutting washer (<NUM>) is distally positioned relative to the anvil plate portion (<NUM>) and proximally positioned relative to the support structure (<NUM>), as shown in <FIG>. The cutting washer (<NUM>) includes a body (<NUM>) that transversely extends relative to the shaft longitudinal axis (LAS) (see <FIG>) from a first end (<NUM>) to a second end (<NUM>), and a tang (<NUM>) that extends proximally from the first end (<NUM>). The body (<NUM>) may be C-shaped, J-shaped, or straight, for example. In the present example, the body (<NUM>) extends along an arcuate path (AP) in a plane that is orthogonal to and intersected by the shaft longitudinal axis (LAS), and is C-shaped. The curved body (<NUM>) includes a distal side (<NUM>) that confronts distal arm (<NUM>) of support structure (<NUM>), and a proximal side (<NUM>) that confronts and supports the anvil plate portion (<NUM>).

The proximal side (<NUM>) of cutting washer body (<NUM>) includes a first end portion (<NUM>), a second end portion (<NUM>), and a middle portion (<NUM>). The first end portion (<NUM>) extends from the first end (<NUM>) toward the middle portion (<NUM>), and the middle portion (<NUM>) further extends toward the second end portion (<NUM>). The second end portion (<NUM>) extends to the second end (<NUM>). The proximal side (<NUM>) also includes a recess (<NUM>) that is defined by a concave surface (<NUM>), a rim (<NUM>), and arcuate protrusion (<NUM>). The concave surface (<NUM>) extends along the curved longitudinal axis of washer body (<NUM>) from the first end (<NUM>) to the second end (<NUM>). The concave surface (<NUM>) proximally faces and extends along the arcuate path (AP).

A rim plane (P1) is defined at the proximal most side of the rim (<NUM>). The rim (<NUM>) is disposed along an outside edge of the concave surface (<NUM>) and extends both proximally and distally from the concave surface (<NUM>). The distally extending portion of rim (<NUM>) is configured to secure the cutting washer (<NUM>) relative to the proximal side of the support structure (<NUM>). In the present example, the rim (<NUM>) extends distally on three sides of the support structure (<NUM>), and includes a pair of clips (<NUM>) on the distal side (<NUM>) of the concave surface (<NUM>) that are configured to aid the support structure (<NUM>) in retaining the cutting washer (<NUM>). In addition to extending distally, the rim (<NUM>) proximally extends around the outside edge of the concave surface (<NUM>) along a first elongate edge (<NUM>), an edge end (<NUM>), and the second elongate edge (<NUM>) to the rim plane (P1). The edge end (<NUM>) of the rim (<NUM>) bends in an arcuate path from the first elongate edge (<NUM>) to the second elongate edge (<NUM>). The edge end (<NUM>) also includes an end retainer (<NUM>) configured to retain a corresponding end of the anvil plate portion (<NUM>).

The arcuate protrusion (<NUM>) proximally extends from concave surface (<NUM>) toward the rim plane (P1). The arcuate protrusion (<NUM>) extends transversely along the arcuate path (AP) generally between the first elongate edge (<NUM>) and the second elongate edge (<NUM>). In the present example, the arcuate protrusion (<NUM>) generally separates the concave surface (<NUM>) and recess (<NUM>) to create first and second longitudinal portions of recess (<NUM>), each of which is disposed between the arcuate protrusion (<NUM>) and a respective one of the first and second elongate edges (<NUM>, <NUM>). As described above, arcuate protrusion (<NUM>) is configured to be received by the arcuate knife slot (<NUM>) of the anvil plate portion (<NUM>).

The first end and second end portions (<NUM>, <NUM>) of cutting washer body (<NUM>) include first and second washer holes (<NUM>, <NUM>), respectively, that longitudinally extend through the concave surface (<NUM>) and are configured to align with the holes (<NUM>, <NUM>), respectively, of cartridge housing (<NUM>). The first and second washer holes (<NUM>, <NUM>) are configured to align the anvil plate portion (<NUM>) with the cutting washer (<NUM>) when the first and second washer holes (<NUM>, <NUM>) receive guide pin (<NUM>) and retaining pin (<NUM>), therethrough respectively.

Tang (<NUM>) of cutting washer (<NUM>) is mated to the first end (<NUM>) and extends proximally and follows the contour of the anvil arm (<NUM>) as the anvil arm (<NUM>) extends proximally. The tang (<NUM>) includes a tang bore (not shown) that extends transversely through the tang (<NUM>) and a tang nub (<NUM>) that extends transversely opposite the direction the body (<NUM>) extends. The tang bore aligns with an anvil arm bore (not shown) on the anvil arm (<NUM>) to accept a pin (not shown) therethrough to secure the anvil arm (<NUM>) to the tang (<NUM>). This locking of the tang (<NUM>) to the anvil arm (<NUM>) longitudinally secures the anvil plate portion (<NUM>) relative to the cutting washer (<NUM>). The tang nub (<NUM>) extends transversely relative to the longitudinal axis of the shaft and is configured to be received within the support structure (<NUM>) to longitudinally locate the cutting washer (<NUM>) relative to the support structure (<NUM>).

As shown best in <FIG>, concave surface (<NUM>) of cutting washer (<NUM>) is shaped such that a middle portion depth (D1) of recess (<NUM>) in the middle portion (<NUM>) of cutting washer body (<NUM>) is greater than first and second end depths (D2, D3) of recess (<NUM>) in the first and second end portions (<NUM>, <NUM>). The depth of recess (<NUM>) is defined by the distance, in a proximal-distal direction, from the rim plane (P1) to the concave surface (<NUM>). As mentioned above, the rim plane (P1) is defined by the proximal most part of the rim (<NUM>) and the proximal most part of the elongate protrusion (<NUM>) when the end effector is in a non-deflected state (see <FIG>). The first and second end portions (<NUM>, <NUM>) of cutting washer body (<NUM>) are sized so that the recess (<NUM>) accepts the anvil plate portion (<NUM>) such that the proximal side of the anvil plate portion (<NUM>) generally lies within the rim plane (P1). In some instances, middle portion (<NUM>) of concave surface (<NUM>) may be formed with a maximum distal depth of approximately <NUM> (<NUM> inches) to approximately <NUM> (<NUM> inches) relative to first and second end portions (<NUM>, <NUM>) of surface (<NUM>).

In the present example, the concave surface (<NUM>) of cutting washer (<NUM>) slopes distally away from the rim plane (P1) as the first end portion (<NUM>) extends towards the middle portion (<NUM>). In some versions, the curvature of the concave surface (<NUM>) may be defined by a single radius that extends around the first end portion (<NUM>), through the middle portion (<NUM>) to the second end portion (<NUM>). In other versions, the curvature of concave surface (<NUM>) may be defined by multiple radii. In the middle portion (<NUM>), the concave surface (<NUM>) continues to slope distally away as the concave surface (<NUM>) extends towards the midpoint (<NUM>) of the middle portion (<NUM>). Once reaching the midpoint (<NUM>) of the middle portion (<NUM>), the concave surface (<NUM>) slopes proximally as it extends towards the second end portion (<NUM>). Once reaching the second end portion (<NUM>) the concave surface (<NUM>) continues to slope proximally until obtaining a depth that generally equals the thickness of anvil plate portion (<NUM>) between the rim (<NUM>) and the concave surface (<NUM>).

In the present version, concave surface (<NUM>) is shaped such that first and second end portions (<NUM>, <NUM>) are generally planar and lie along a datum plane (not shown) defined by the distal side of the anvil plate portion (<NUM>). Additionally, surface (<NUM>) may be shaped such that concave middle portion (<NUM>) comprises approximately <NUM>% of the arcuate length of surface (<NUM>), while first and second planar end portions (<NUM>, <NUM>) jointly comprise the remaining <NUM>% of the arcuate length of surface (<NUM>). Additionally, relative to a center point along the arcuate length of surface (<NUM>), concave middle portion (<NUM>) may extend angularly along an arc of approximately <NUM> degrees in each of a first direction toward first end (<NUM>) of washer body (<NUM>) and also a second direction toward second end (<NUM>) of washer body (<NUM>).

The first and second end portions (<NUM>, <NUM>) are configured to engage the anvil plate portion (<NUM>) in a non-deflected state along the datum plane before stapler (<NUM>) is fired. Accordingly, the datum plane acts as a deflection baseline for the deflection of the anvil plate portion (<NUM>). The middle portion (<NUM>) of concave surface (<NUM>) is a distance distal from the first and second end portions (<NUM>, <NUM>) and smoothly blends with a curvature into the first and second end portions (<NUM>, <NUM>). The concave surface (<NUM>) is shaped such that a deepest, distal-most point of middle portion (<NUM>) defining recess (<NUM>) is centered along the arcuate length of arcuate protrusion (<NUM>). In the present version, the first and second end portions (<NUM>, <NUM>) engage the anvil plate portion (<NUM>) evenly along their lengths as the first and second end portions (<NUM>, <NUM>) gradually transition to middle portion (<NUM>), which contours smoothly away from the anvil plate portion (<NUM>) in the non-deflected state before firing. In some versions, the contour of the middle portion (<NUM>) of concave surface (<NUM>) may be stepped distally away from the first and second end portions (<NUM>, <NUM>).

In the non-deflected state of anvil plate portion (<NUM>) (see <FIG>), the distal side of a first end of the anvil plate portion (<NUM>) rests against the proximal side of the first end (<NUM>) of the cutting washer (<NUM>), and the distal side of a second end of the anvil plate portion (<NUM>) rests against the second end (<NUM>) of the cutting washer (<NUM>). The distal side of the anvil plate portion (<NUM>) and the concave surface (<NUM>) define a gap (<NUM>) (see <FIG>) that is bordered on the sides by the rim (<NUM>) and the arcuate protrusion (<NUM>) within the recess (<NUM>).

<FIG> schematically shows anvil plate portion (<NUM>) in the non-deflected state when end effector (<NUM>) is in an open position (see <FIG>). A proximal side of the laterally projecting distal arm (<NUM>) of support structure (<NUM>) is shown abutting distal side (<NUM>) of the cutting washer (<NUM>). The concave surface (<NUM>) is located on the proximal side (<NUM>) of the cutting washer (<NUM>) as described above and confronts the distal side of anvil plate portion (<NUM>) such that first and second ends (<NUM>, <NUM>) or first and second end portions (<NUM>, <NUM>) of cutting washer body (<NUM>) may directly contact and support the first and second ends of the anvil plate portion (<NUM>). The gap (<NUM>) that is distally rounded lies between the concave surface (<NUM>) and the distal side of the anvil plate portion (<NUM>). Accordingly, in this non-deflected state of anvil plate portion (<NUM>), at least a middle portion of anvil plate portion (<NUM>) is spaced proximally from middle portion (<NUM>) of cutting washer body (<NUM>).

As shown schematically in <FIG>, anvil plate portion (<NUM>) has transitioned into a distally deflected state relative to cutting washer (<NUM>). Such deflection of anvil plate portion (<NUM>) may occur in response to actuation of end effector (<NUM>) to the closed position (see <FIG>) for clamping tissue, and/or upon actuation of end effector (<NUM>) to a fired state (see <FIG>) in which staples (not shown) and knife (<NUM>) have been driven distally through the clamped tissue. The distally-directed staple forming forces and/or tissue compression forces exerted on anvil plate portion (<NUM>) cause the middle portion of anvil plate portion (<NUM>) to deflect distally into the gap (<NUM>) (see <FIG>) defined by recess (<NUM>) of cutting washer (<NUM>) such that the distal side of the anvil plate portion (<NUM>) confronts, generally conforms to, and optionally contacts the concave surface (<NUM>) of cutting washer (<NUM>) from the first end (<NUM>) to the second end (<NUM>).

This permitted distal deflection of the anvil plate portion (<NUM>) into the gap (<NUM>) provides an optimized staple forming surface that results in more uniform staple heights across the length of anvil plate portion (<NUM>) when stapler (<NUM>) is fired. More specifically, the distal deflection of the middle portion of anvil plate portion (<NUM>) into the gap (<NUM>) may mitigate and/or compensate for cantilevered distal displacement of the free end (<NUM>) of support structure distal arm (<NUM>) relative to fixed end (<NUM>) (see <FIG>) when end effector (<NUM>) is closed and fired, as well as any proximal deflection of an inward portion of distal arm (<NUM>), by providing a relatively uniform distal spacing between staple deck (<NUM>) and anvil plate portion (<NUM>) along the arcuate lengths thereof while end effector (<NUM>) remains closed on tissue. Uniformity of this distal spacing (also referred to as "tissue gap distance") along the lengths of staple deck (<NUM>) and anvil plate portion (<NUM>) enables the staples ejected by cartridge housing (<NUM>) to be formed by anvil plate portion (<NUM>) with relatively uniform heights along the lengths of staple deck (<NUM>) and anvil plate portion (<NUM>). The resulting uniformity of formed staple heights yields consistent and effective hemostasis along the stapled section of tissue. In some instances, all or a portion of surface (<NUM>) of washer (<NUM>) may be tapered along its arcuate length to further mitigate the undesirable effects described above caused by the cantilever distal deflection of distal arm (<NUM>) during closure and/or firing of end effector (<NUM>).

In some instances, it may be desirable to substitute or supplement concave proximal surface (<NUM>) of cutting washer (<NUM>) with a concave surface formed on another portion of end effector (<NUM>) to promote uniform staple heights. <FIG> shows a portion of another example of an end effector (<NUM>) including a concave surface (<NUM>) that provides such functional benefits. End effector (<NUM>) is constructed and operable similar to end effector (<NUM>) described above, except as otherwise described below.

In this example, the concave surface (<NUM>) is on the proximal side of the laterally projecting distal arm (<NUM>) may be shaped similar to concave surface (<NUM>) described above. The end effector (<NUM>) is shown in an open position (see <FIG>). The concave surface (<NUM>) of the laterally projecting distal arm (<NUM>) is configured to engage a distal side of the cutting washer (<NUM>) at first and second ends (<NUM>, <NUM>) and defines a gap (<NUM>) that is distally rounded between the concave surface (<NUM>) and the distal side of the cutting washer (<NUM>). The distal side of the cutting washer (<NUM>) defines a datum plane that serves as a plane of engagement along which the first and second ends (<NUM>, <NUM>) of the cutting washer (<NUM>) engage the laterally projecting distal arm (<NUM>) in the non-deflected state. The proximal side of the cutting washer (<NUM>) is mated flush with the anvil plate portion (<NUM>).

When the end effector (<NUM>) transitions to the closed position to clamp tissue (see <FIG>) and is subsequently fired to staple and cut the clamped tissue, as detailed above, the staple forming forces and/or tissue compression forces deflect at least the middle portion of the anvil plate portion (<NUM>) and the middle portion of the cutting washer (<NUM>) in a distal direction and fills the gap (<NUM>). During such deflection, the distal side of the cutting washer (<NUM>) is configured to mate with the concave surface (<NUM>), and the distal side of the anvil plate portion (<NUM>) is configured to remain mated to the proximal side of the cutting washer (<NUM>) such that anvil plate portion (<NUM>) and washer (<NUM>) are configured to deflect distally together into the gap (<NUM>). The deflection of the cutting washer (<NUM>) and the anvil plate portion (<NUM>) into the gap (<NUM>) may provide a uniform tissue gap distance between staple deck (<NUM>) and anvil plate portion (<NUM>) along the lengths thereof that compensates for and minimizes distal displacement of free end (<NUM>) of support structure distal arm (<NUM>) relative to its fixed end (<NUM>). This uniformity of tissue gap distance promotes uniform, proper staple heights along end effector (<NUM>) that provide effective hemostasis in the stapled tissue.

<FIG> shows a portion of yet another example of an end effector (<NUM>) including a concave surface (<NUM>) that provides similar functional benefits to concave surfaces (<NUM>, <NUM>) described above. End effector (<NUM>) is similar in construction and function to end effector (<NUM>) described above, except as otherwise described below.

In this example, the concave surface (<NUM>) is on the distal side of the anvil plate portion (<NUM>). The end effector (<NUM>) is shown in an open position (see <FIG>) and extends from a first end (<NUM>) to a second end (<NUM>). A distal side of the anvil plate portion (<NUM>) includes concave surface (<NUM>), which may be shaped similar to concave surface (<NUM>) described above. The concave surface (<NUM>) engages the proximal side of the cutting washer (<NUM>) at the first and second ends (<NUM>, <NUM>). The proximal side of the cutting washer (<NUM>) defines a datum plane that serves as a plane of engagement along which the first and second ends (<NUM>, <NUM>) of the cutting washer (<NUM>) engage the anvil plate portion (<NUM>) in the non-deflected state. The cutting washer (<NUM>) is mated flush with the laterally projecting distal arm (<NUM>) of support structure (<NUM>). The concave surface (<NUM>) and the cutting washer (<NUM>) define a gap (<NUM>) that is proximally rounded between the first and second ends (<NUM>, <NUM>).

When the end effector (<NUM>) transitions to the closed position to clamp tissue (see <FIG>) and is subsequently fired to staple and cut the clamped tissue as detailed above, the staple forming forces and/or tissue compression forces deflect the middle portion of the anvil plate portion (<NUM>) in a distal direction and fills the gap (<NUM>). The concave surface (<NUM>) of the anvil plate portion (<NUM>) is configured to deflect distally and mate with the proximal side of the cutting washer (<NUM>) while the distal side of the cutting washer (<NUM>) remains mated to the proximal side of the laterally projecting distal arm (<NUM>). The deflection of the anvil plate portion (<NUM>) into the gap (<NUM>) may provide a uniform tissue gap distance between staple deck (<NUM>) and anvil plate portion (<NUM>) along the lengths thereof that compensates for and minimizes distal displacement of free end (<NUM>) of support structure distal arm (<NUM>) relative to its fixed end (<NUM>). This uniformity of tissue gap distance promotes uniform, proper staple heights along end effector (<NUM>) that provide effective hemostasis in the stapled tissue.

<FIG> shows yet another example of an end effector (<NUM>) including a concave surface (<NUM>) that provides similar functional benefits to concave surfaces (<NUM>, <NUM>, <NUM>) described above. End effector (<NUM>) is similar in construction and function to end effector (<NUM>) described above, except as otherwise described below.

In this example, the concave surface (<NUM>) is on the distal side of the cutting washer (<NUM>). The end effector (<NUM>) is shown in an open position (see <FIG>) and extends from a first end (<NUM>) to a second end (<NUM>). A distal side of the cutting washer (<NUM>) includes the concave surface (<NUM>), which may be shaped similar to concave surface (<NUM>) described above. The proximal side of the laterally projecting distal arm (<NUM>) defines a datum plane that serves as a plane of engagement along which the first and second ends (<NUM>, <NUM>) of the cutting washer (<NUM>) engage the laterally projecting distal arm (<NUM>) in the non-deflected state. The proximal side of cutting washer (<NUM>) is mated flush with the distal side of the anvil plate portion (<NUM>). The concave surface (<NUM>) and the laterally projecting distal arm (<NUM>) define a gap (<NUM>) that is proximally rounded between the first and second ends (<NUM>, <NUM>). The proximal side of the cutting washer (<NUM>) is mated flush with the anvil plate portion (<NUM>).

When the end effector (<NUM>) transitions to the closed position to clamp tissue (see <FIG>) and is subsequently fired to staple and cut the clamped tissue as detailed above, the staple forming forces and/or tissue compression forces deflect the middle portion of the cutting washer (<NUM>) distally into the gap (<NUM>). In particular, concave surface (<NUM>) of the cutting washer (<NUM>) deflects distally and mates with the proximal side of the laterally projecting distal arm (<NUM>) while the proximal side of the cutting washer (<NUM>) remains mated to the distal side of anvil plate portion (<NUM>). Accordingly, in the present version, the middle portions of anvil plate portion (<NUM>) and cutting washer (<NUM>) are configured to deflect distally together into the gap (<NUM>) when end effector (<NUM>) is fired. The deflection of the anvil plate portion (<NUM>) and washer (<NUM>) into the gap (<NUM>) may provide a uniform tissue gap distance between staple deck (<NUM>) and anvil plate portion (<NUM>) along the lengths thereof that compensates for and minimizes distal displacement of free end (<NUM>) of support structure distal arm (<NUM>) relative to its fixed end (<NUM>). This uniformity of tissue gap distance promotes uniform, proper staple heights along end effector (<NUM>) that provide effective hemostasis in the stapled tissue.

Similarly, those of ordinary skill in the art will recognize that various teachings herein may be readily combined with various teachings of any of the following: <CIT>; <CIT>; and/or <CIT>.

Upon cleaning and/or replacement of particular parts, some versions of the device may be reassembled for subsequent use either at a reconditioning facility, or by an operator immediately prior to a procedure.

Claim 1:
An apparatus comprising:
(a) a housing (<NUM>) that includes a plurality of staples;
(b) an anvil (<NUM>) opposed from the housing, the anvil including an anvil plate portion (<NUM>), wherein the anvil and the housing are configured to cooperate to clamp tissue, wherein the anvil is configured to form staples ejected from the housing into the clamped tissue;
(c) a backing member (<NUM>) comprising a proximal side coupled with the anvil plate portion; and
(d) a concave surface (<NUM>, <NUM>, <NUM>, <NUM>) that defines a gap (<NUM>, <NUM>, <NUM>, <NUM>) between the backing member and an adjacent component of the apparatus,
characterised in that
the anvil plate portion comprises a middle portion configured to deflect distally in a direction toward the gap in response to actuation of the apparatus to at least one of clamp tissue or staple tissue such that, when deflected, the anvil plate portion generally conforms to the concave surface.