Patent Description:
Circular stapling devices typically include a shell or reload assembly that includes a staple cartridge that supports one or more annular rows of staples, a staple pusher for ejecting the staples from the staple cartridge, and an annular knife that is positioned radially inward of the annular rows of staples for cutting tissue. The knife can be movable simultaneously with the staple pusher or independently of the staple pusher to cut tissue during a surgical procedure, e.g., an anastomosis procedure.

During an anastomosis procedure, two tubular sections of tissue are attached to one another and the sections of tissue within the annular knife are cored with the knife to define a hollow passage between the joined tubular sections. Generally, a tissue donut remains within the annular knife of the reload assembly after the tissue sections have been cut. When the reload assembly is removed from a patient, the tissue donut is removed from within the knife by the clinician.

After a circular stapling device is actuated to cut tissue during an anastomosis procedure, the knife is moved from an advanced position to a retracted position in which a cutting edge of the knife is recessed and shielded within a shell housing of the reload assembly. During removal of the tissue donut from within the annular knife, the cutting edge of the knife is pulled in a direction back towards the advanced position and may become exposed.

<CIT> discloses a circular stapler with a cartridge assembly.

Certain optional features of the invention are defined in the dependent claims.

The techniques of this disclosure generally relate to circular stapling devices having a knife to cut tissue.

One aspect of the disclosure is directed to a reload assembly that includes a shell housing, a staple cartridge, a staple pushing member, a knife carrier, and a knife assembly. The shell housing defines a cavity and has a proximal portion and a distal portion. The staple cartridge is supported on the distal portion of the shell housing and supports a plurality of staples. The staple pushing member is movable within the shell housing between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge. The staple pushing member defines a longitudinal bore. The knife carrier is supported within the longitudinal bore of the staple pushing member and is movable between retracted and advanced positions within the shell housing. The knife assembly includes a distal knife portion and a proximal knife portion. The proximal knife portion is secured to the knife carrier and is movable with the knife carrier as the knife carrier is moved between its retracted and advanced positions. The distal knife portion is in abutting relation with the proximal knife portion, such that the knife carrier is movable from its advanced position to its retracted position independently of the distal knife portion.

Another aspect of the disclosure is directed to a stapling device including a handle assembly, an adaptor assembly, an anvil assembly, and a reload assembly. The adaptor assembly extends from the handle assembly and has a distal end portion. The anvil assembly includes a cut ring. The reload assembly is supported on the distal end portion of the adaptor assembly and includes a shell housing, a staple cartridge, a staple pushing member, a knife carrier, and a knife assembly. The shell housing defines a cavity and has a proximal portion and a distal portion. The staple cartridge is supported on the distal portion of the shell housing and supports a plurality of staples. The staple pushing member is movable within the shell housing between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge. The staple pushing member defines a longitudinal bore. The knife carrier is supported within the longitudinal bore of the staple pushing member. The knife carrier is movable between retracted and advanced positions within the shell housing. The knife assembly includes a distal knife portion and a proximal knife portion. The proximal knife portion is secured to the knife carrier and is movable with the knife carrier between retracted and advanced positions as the knife carrier is moved between its retracted and advanced positions. The distal knife portion is in abutting relation with the proximal knife portion such that movement of the proximal knife portion to its advanced position moves the distal knife portion to an advanced position. The knife carrier is movable from its advanced position to its retracted position independently of the distal knife portion.

Another aspect of the disclosure is directed to a reload assembly including a shell housing, a staple cartridge, a staple pushing member, and a knife assembly. The shell housing defines a cavity and has a proximal portion and a distal portion. The staple cartridge is supported on the distal portion of the shell housing and supports a plurality of staples. The staple pushing member is movable within the shell housing between an advanced position and a retracted position to eject the plurality of staples from the staple cartridge. The staple pushing member defines a longitudinal bore. The knife assembly includes a distal knife portion and a proximal knife portion. The distal knife portion is in abutting relation with the proximal knife portion such that the proximal knife portion is movable from its advanced position to its retracted position independently of the distal knife portion.

In aspects of the disclosure, the proximal and distal knife portions are annular.

In some aspects of the disclosure, the proximal knife portion has a first diameter and the distal knife portion has a second diameter, wherein the first diameter is equal to the second diameter.

In certain aspects of the disclosure, the distal knife portion includes an annular cutting edge.

In aspects of the disclosure, the knife carrier includes a distal body portion that includes distal extensions that extend along the knife assembly to maintain alignment of the proximal and distal knife portions.

In some aspects of the disclosure, the distal knife portion includes an opening positioned adjacent and proximal to the annular cutting edge.

In aspects of the disclosure, the opening is dimensioned to receive a retention member of an anvil assembly.

In certain aspects of the disclosure, the reload assembly includes a coupling mechanism that is adapted to secure the reload assembly to a stapling device.

Various aspects and features of the disclosure are described with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views and:.

The disclosed reload assembly in association with a surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the disclosed aspects are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

In this description, the term "proximal" is used generally to refer to that portion of the device that is closer to a clinician during use of the device in its customary manner, while the term "distal" is used generally to refer to that portion of the device that is farther from the clinician during use of the device in its customary manner. Further, the term "clinician" is used generally to refer to medical personnel including doctors, nurses, and support personnel.

<FIG> illustrates a circular stapling device <NUM> including a reload assembly in accordance with aspects of the disclosure shown generally as a reload assembly <NUM>. The circular stapling device <NUM> includes a handle assembly <NUM>, an elongate body or adaptor assembly <NUM>, the reload assembly <NUM>, and an anvil assembly <NUM> that is supported for movement in relation to the reload assembly <NUM> between a spaced position (<FIG>) and a clamped position (<FIG>). The reload assembly <NUM> includes a proximal portion <NUM> that is releasably coupled to a distal portion of the adaptor assembly <NUM> and the adaptor assembly <NUM> includes a proximal portion that is releasably coupled to the handle assembly <NUM>. The handle assembly <NUM> includes a stationary grip <NUM> that supports actuation buttons <NUM> for controlling operation of various functions of the circular stapling device <NUM> including approximation of the reload assembly <NUM> and anvil assembly <NUM>, firing of staples from the reload assembly <NUM>, and cutting or coring of tissue as described in further detail below. It is envisioned that the handle assembly <NUM>, the adaptor assembly <NUM>, and/or the reload assembly could be fixedly secured to each other.

The circular stapling device <NUM> is illustrated as an electrically powered stapling device including an electrically powered handle assembly <NUM> that may support one or more batteries (not shown). The adaptor assembly <NUM> translates power from the handle assembly <NUM> to the reload and anvil assemblies <NUM>, <NUM>, respectively, to staple and cut tissue. Examples of electrically powered stapling devices can be found in <CIT>, <CIT>, and <CIT>, and <CIT>. Alternately, it is envisioned that aspects of the reload assembly <NUM> disclosed herein could also be incorporated into a manually powered stapling device such as disclosed in, e.g., <CIT> (the '<NUM> Patent), or a stapling device that is configured for use with a robotic system as disclosed in, e.g., <CIT>, that does not include a handle assembly.

<FIG> illustrates an exploded view of the reload assembly <NUM> which includes a shell housing <NUM>, a staple actuator <NUM>, a staple pushing member 112a, a knife carrier <NUM>, an annular knife assembly <NUM> supported on the knife carrier <NUM>, a staple cartridge <NUM>, and a plurality of staples <NUM> supported within the staple cartridge <NUM>. The shell housing <NUM> includes an outer housing portion <NUM> and an inner housing portion <NUM> that are spaced from each other to define an annular cavity <NUM> (<FIG>) positioned between the outer and inner housing portions <NUM> and <NUM>. The staple actuator <NUM> and the staple pushing member 112a are movable within the annular cavity <NUM> of the shell housing <NUM> from a retracted position to an advanced position to eject the staples <NUM> from the staple cartridge <NUM> as described in further detail below.

The staple cartridge <NUM> is annular and defines annular rows of staple pockets <NUM>. Each of the staple pockets <NUM> supports one of the staples <NUM>. The staple actuator <NUM> and the staple pushing member 112a together define a longitudinal through bore <NUM> (<FIG>) that receives the knife carrier <NUM>. The staple actuator <NUM> has a distal portion that abuts a proximal portion of the staple pushing member 112a such that distal movement of the staple actuator <NUM> within the shell housing <NUM> causes distal movement of the staple pushing member 112a within the shell housing <NUM>. The staple pushing member 112a of the reload assembly <NUM> has a plurality of fingers <NUM>. Each of the plurality of fingers <NUM> is received within a respective one of the staple pockets <NUM> of the staple cartridge <NUM> and is movable through the respective staple pocket <NUM> to eject the staples <NUM> from the staple pockets <NUM> when the staple pushing member 112a is moved from its retracted position to its advanced position within the shell housing <NUM>.

The knife carrier <NUM> is received within the longitudinal through bore <NUM> of the staple actuator <NUM> and includes a distal body portion <NUM> and a plurality of spaced longitudinally extending proximal body portions <NUM>. The distal body portion <NUM> and the proximal body portions <NUM> define a stepped central bore having a proximal portion 144a and a distal portion 144b. The proximal portion 144a of the stepped central bore of the knife carrier <NUM> slidably receives the inner housing portion <NUM> of the shell housing <NUM> such that the knife carrier <NUM> is movable within the staple actuator <NUM> about the inner housing portion <NUM> of the shell housing <NUM> between a retracted position (<FIG>) and an advanced position (<FIG>). The distal body portion <NUM> of the knife carrier <NUM> includes a plurality of longitudinal extensions <NUM> that are described in further detail below. The proximal body portions <NUM> of the knife carrier <NUM> defines slots <NUM> that receive guide portions (not shown) of the shell housing <NUM> to limit the knife carrier <NUM> to longitudinal movement within the shell housing <NUM>.

<FIG> illustrate the annular knife assembly <NUM> of the reload assembly <NUM> which includes a proximal knife portion <NUM> and a distal knife portion <NUM>. The proximal knife portion <NUM> is annular and includes inwardly extending tangs <NUM> that are received within recesses <NUM> (<FIG>) defined within the distal body portion <NUM> of the knife carrier <NUM> to secure the proximal knife portion <NUM> about the knife carrier <NUM>. Alternately, other techniques can be used to secure the proximal knife portion <NUM> to the knife carrier <NUM>. The distal knife portion <NUM> of the knife assembly <NUM> is also annular and includes a proximal end 152a and a distal end 152b. The distal knife portion <NUM> has a diameter that is substantially equal to the diameter of the proximal knife portion <NUM> such that the proximal end 152a of the distal knife portion <NUM> is positioned in abutting relation to a distal end 150a of the proximal knife portion <NUM>. The distal end 152b of the distal knife portion <NUM> defines an annular cutting edge <NUM>. The distal knife portion <NUM> of the knife assembly <NUM> is received about the longitudinal extensions <NUM> (<FIG>) of the knife carrier <NUM>. Engagement between the distal knife portion <NUM> of the knife assembly <NUM> and the longitudinal extensions <NUM> of the knife carrier <NUM> maintains alignment between the distal knife portion <NUM> and the proximal knife portion <NUM> (<FIG>).

<FIG> illustrates a proximal portion <NUM> of the shell housing <NUM> that supports a coupling mechanism <NUM> (<FIG>). The coupling mechanism <NUM> is operable to releasably couple the reload assembly <NUM> to the adaptor assembly <NUM> of the stapling device <NUM> (<FIG>) to facilitate replacement of the reload assembly <NUM> and reuse of the stapling device <NUM>. The coupling mechanism <NUM> includes a retaining member <NUM> and a coupling member <NUM>. The coupling member <NUM> is received about the proximal portion <NUM> of the shell housing <NUM> and is configured to engage the distal portion 14a (<FIG>) of the adaptor assembly <NUM> to couple the adaptor assembly <NUM> to the reload assembly <NUM>. It is envisioned that other coupling mechanisms can be used to secure the reload assembly <NUM> to the adaptor <NUM>.

The reload assembly <NUM> may include an e-prom holder <NUM> (<FIG>) that is supported on the shell housing <NUM> to support an e-prom (not shown). As is known in the art, an e-prom communicates with the adaptor assembly <NUM> to provide information to the adaptor assembly <NUM> and the handle assembly <NUM> related to characteristics of the reload assembly <NUM>.

<FIG> illustrates the reload assembly <NUM> and the anvil assembly <NUM> in a pre-fired, unclamped position. In this position, the staple actuator <NUM>, the staple pushing member 112a, the knife carrier <NUM>, and the annular knife assembly <NUM> are in their retracted positions with the proximal knife portion <NUM> secured to the knife carrier <NUM> and the distal knife portion <NUM> positioned in abutting relation with the proximal knife portion <NUM> between the longitudinal extensions <NUM> of the knife carrier <NUM> and an inner wall of the staple cartridge <NUM>.

The anvil assembly <NUM> includes housing <NUM> and a cut ring assembly <NUM> that is received within a cavity 48a defined by the housing <NUM> and includes a compliant cut ring <NUM> and a rigid backup plate <NUM>. In aspects of the disclosure, the cut ring assembly <NUM> is movable within the cavity 48a from a retracted position to an advanced position in response to being engaged by the knife assembly <NUM> as described below. The compliant cut ring <NUM> is formed of a material that can be penetrated by the knife assembly <NUM> to facilitate the cutting of tissue clamped between the anvil assembly <NUM> and the staple cartridge <NUM> of the reload assembly <NUM>.

<FIG> illustrates the reload assembly <NUM> and the anvil assembly <NUM> in a clamped and fired position. In this position, the staple actuator <NUM>, the staple pushing member 112a, the knife carrier <NUM>, and the annular knife assembly <NUM> have been moved in the direction indicated by arrow "A" to their advanced positions. As illustrated, in the advanced position of the staple pushing member 112a, the fingers <NUM> of the staple pushing member 112a are received within the staple pockets <NUM> of the staple cartridge <NUM> to drive the staples <NUM> from the staple pockets <NUM> and form the staples against the anvil assembly <NUM>. In the advanced position of the knife assembly <NUM>, the distal knife portion <NUM> of the knife assembly <NUM> is engaged with and penetrates the compliant cut ring <NUM>.

<FIG> and <FIG> illustrate the reload assembly <NUM> and the anvil assembly <NUM> in a post-fired unclamped position. In this position, the staple actuator <NUM> and the knife carrier <NUM> are returned in the direction indicated by arrows "B" to their retracted positions. Since the staple pushing member 112a and the staple actuator <NUM> are only in abutting relation, the staple pushing member 112a remains in an advanced position with the fingers <NUM> received within the staple pockets <NUM> of the staple cartridge <NUM>. Similarly, since the proximal knife portion <NUM> is only in abutting relation to the distal knife portion <NUM> of the knife assembly <NUM>, the distal knife portion <NUM> remains in its advanced position engaged with the compliant cut ring <NUM> when the knife carrier <NUM> and proximal knife portion <NUM> return to their retracted position. It is noted frictional engagement between the distal knife portion <NUM> and the compliant cut ring <NUM> of the cut ring assembly <NUM> retains the distal knife portion <NUM> in its advanced position with the annular cutting edge <NUM> of the distal knife portion <NUM> of the knife assembly <NUM> buried within and shielded by the compliant cut ring <NUM>.

<FIG> illustrate another reload assembly according to other aspects of the disclosure shown generally as reload assembly <NUM>. The reload assembly <NUM> is substantially identical to reload assembly <NUM> except that the distal knife portion <NUM> of the knife assembly <NUM> includes a recess or opening <NUM>. The anvil assembly <NUM> also includes a cut ring assembly <NUM> including a compliant cut ring <NUM> that defines a bore <NUM> that is positioned to receive the distal knife portion <NUM> of the knife assembly <NUM> when the knife assembly <NUM> is moved from its retracted position (<FIG>) to its advanced position. The compliant cut ring <NUM> includes a retention member <NUM> that extends into the bore <NUM> and is received within the opening <NUM> in the distal knife portion <NUM> when the knife assembly <NUM> is in its advanced position (<FIG>) and the distal knife portion <NUM> is positioned within the bore <NUM>.

<FIG> illustrates the reload assembly <NUM> with the staple pushing member 212a and the annular knife assembly <NUM>, including the distal knife portion <NUM>, in a retracted position. In this position, the fingers <NUM> of the staple pushing member 212a are spaced proximally of the staples <NUM> within the staple pockets <NUM> of the staple cartridge <NUM>. In addition, the annular knife assembly <NUM> is recessed within the shell housing <NUM> such that the cutting edge <NUM> of the distal knife portion <NUM> is shielded by the shell housing <NUM>. As illustrated, the longitudinal extensions <NUM> of the knife carrier <NUM> extend along the proximal and distal knife portions <NUM> and <NUM> respectively to maintain alignment between the proximal and distal knife portions <NUM> and <NUM>.

<FIG> illustrates the reload assembly <NUM> as the staple pushing member 212a and the knife carrier <NUM> and knife assembly <NUM> are moved towards their advanced positions. As the staple pushing member 212a moves towards its advanced position, the fingers <NUM> of the staple pushing member 212a move through the staple pockets <NUM> of the staple cartridge <NUM> to eject the staples <NUM> from the staple cartridge <NUM>. In addition, the knife carrier <NUM> advances to advance the knife assembly <NUM> in the direction indicated by arrow "C" to move the distal knife portion <NUM> of the knife assembly <NUM> into the bore <NUM> formed in the compliant cut ring <NUM> of the cut ring assembly <NUM>. As the cutting edge <NUM> of the distal knife portion <NUM> of the knife assembly <NUM> enters the bore <NUM>, the cutting edge <NUM> engages and passes over the retention member <NUM>.

<FIG> illustrates the knife carrier <NUM> and the knife assembly <NUM> in their advanced positions. In the advanced position of the knife assembly <NUM>, the distal knife portion <NUM> is positioned such that the retention member <NUM> of the compliant cut ring <NUM> is received in the opening <NUM> in the distal knife portion <NUM> to retain the distal knife portion <NUM> in its advanced position. When the knife carrier <NUM> is returned to its retracted position with the proximal knife portion <NUM> attached to the knife carrier <NUM>, the distal knife portion <NUM> remains attached to the compliant cut ring <NUM> to retain the cutting edge <NUM> of the distal knife portion <NUM> shielded within the bore <NUM> of the compliant cut ring <NUM>.

<FIG> the reload assembly <NUM> and the anvil assembly <NUM> in a post-fired unclamped position. In this position, the staple actuator (not shown) and the knife carrier <NUM> are returned in the direction indicated by arrows "D" to their retracted positions. Since the staple pushing member 212a and the staple actuator (not shown) are only in abutting relation, the staple pushing member 212a remains in an advanced position with the fingers <NUM> received within the staple pockets <NUM> of the staple cartridge <NUM>. Similarly, since the proximal knife portion <NUM> is only in abutting relation to the distal knife portion <NUM> of the knife assembly <NUM>, the distal knife portion <NUM> remains in its advanced position engaged with the compliant cut ring <NUM> when the knife carrier <NUM> and proximal knife portion <NUM> return to their retracted position. It is noted that receipt of the retention member <NUM> of the compliant cut ring <NUM> within the opening <NUM> of the distal knife portion <NUM> retains the distal knife portion <NUM> in its advanced position with the annular cutting edge <NUM> of the distal knife portion <NUM> of the knife assembly <NUM> buried within and shielded by the compliant cut ring <NUM>.

Although not illustrated herein, it is envisioned that the knife assembly <NUM>, <NUM> can be directly secured to the staple actuator <NUM>, <NUM> such that the knife assembly <NUM>, <NUM> is moved simultaneously with the staple actuator <NUM>, <NUM> and the staple pushing member 112a, 212a. In such a device, the knife carrier <NUM> need not be included in the reload assembly <NUM>, <NUM>.

Claim 1:
A stapling device (<NUM>) comprising:
a handle assembly (<NUM>);
an adaptor assembly (<NUM>) extending from the handle assembly, the adaptor assembly having a distal end portion (14a);
an anvil assembly (<NUM>) including a cut ring (<NUM>, <NUM>); and
a reload assembly (<NUM>, <NUM>) supported on the distal end portion (14a) of the adaptor assembly (<NUM>), the reload assembly including:
a shell housing (<NUM>, <NUM>) defining a cavity (<NUM>) and having a proximal portion and a distal portion;
a staple cartridge (<NUM>, <NUM>) supported on the distal portion of the shell housing, the staple cartridge supporting a plurality of staples (<NUM>, <NUM>);
a staple pushing member (112a, 212a) movable within the shell housing (<NUM>, <NUM>) between an advanced position and a retracted position to eject the plurality of staples (<NUM>, <NUM>) from the staple cartridge (<NUM>, <NUM>), the staple pushing member defining a longitudinal bore; and
a knife assembly (<NUM>, <NUM>);
characterised in that the knife assembly includes a distal knife portion (<NUM>, <NUM>) and a proximal knife portion (<NUM>, <NUM>), the distal knife portion positioned in abutting relation with the proximal knife portion such that movement of the proximal knife portion to an advanced position moves the distal knife portion to an advanced position, wherein the distal knife portion in its advanced position is retained in the cut ring (<NUM>, <NUM>) of the anvil assembly (<NUM>), whereby the proximal knife portion is movable from its advanced position to its retracted position independently of the distal knife portion when the distal knife portion is retained in engagement with the cut ring (<NUM>, <NUM>).