Patent Description:
Surgical stapling devices for ejecting staples to join tissue or tissue segments in a fast and efficient manner in a variety of surgical procedures, e.g., anastomoses procedures, are well known. Surgical stapling devices include a tool assembly having a cartridge assembly and an anvil assembly. The cartridge assembly and the anvil assembly define tissue contact surfaces that define a tissue gap when the tool assembly is in a clamped position. The tissue gap is dimensioned to receive tissue of a given thickness range to effect hemostasis. If the tissue positioned between the jaws is outside the defined range, either too thick or too thin, the tissue contact surfaces of the cartridge and anvil assemblies may not be properly positioned during firing of the stapling device to provide effective hemostasis. In addition, if the tissue thickness is misidentified by the clinician or if the tissue thickness falls near the outer edges of the range for a given staple size, the likelihood of ineffective hemostasis is increased.

<CIT> shows a surgical stapling device relevant to the background to the invention. This document discloses a cartridge assembly which comprises compression members between the cartridge channel and the cartridge.

Accordingly, a continuing need exists in the suturing arts for a surgical stapling device that is capable of providing effective hemostasis for a greater range of tissue thicknesses.

According to the invention there is provided, in a first aspect, a cartridge assembly as recited in claim <NUM> with preferred features as set forth in the claims dependent therefrom. In a second aspect of the invention there is provided a surgical stapling device incorporating a staple cartridge in accordance with the first aspect.

Various embodiments of the presently disclosed tool assembly are described herein below with reference to the drawings, wherein:.

The presently disclosed surgical stapling device including a tool assembly with a floating staple cartridge 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. In this description, the term "proximal" is used generally to refer to that portion of the device that is closer to a clinician, while the term "distal" is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term "endoscopic" is used generally used to refer to endoscopic, laparoscopic, arthroscopic, and/or any other procedure conducted through small diameter incision or cannula. In addition, the term clinician is used generally to refer to medical personnel including doctors, nurses, and support personnel.

The presently disclosed surgical stapling device includes a tool assembly having an anvil assembly and a cartridge assembly including a cartridge channel and a staple cartridge supported within the cartridge channel. The cartridge assembly includes a cartridge channel having a pair of spaced sidewalls and a bottom wall. The cartridge assembly includes compression strips that are supported on upper edges of the side walls of the cartridge channel and are positioned to support the staple cartridge. In embodiments, each of the compression strips includes a connecting portion and the upper edge of each of the side walls defines a slot that is configured to receive the connecting portion of a respective compression strip to secure the compression strips to the side walls of the cartridge channel. The compression strips allow the staple cartridge to move or float in relation to the anvil assembly of the tool assembly to accommodate tissues of different thicknesses.

In some embodiments, the tool assembly also includes a compressible pad that is supported on the bottom wall of the channel. The staple cartridge is supported on the compressible pad within the cartridge channel such that the staple cartridge can move or float within the cartridge channel.

<FIG> illustrates an exemplary embodiment of the presently disclosed surgical stapling device shown generally as <NUM>. The stapling device <NUM> includes a handle assembly <NUM>, a body portion <NUM> that defines a longitudinal axis "X" and extends from a distal portion of the handle assembly <NUM>, and a tool assembly <NUM> supported on a distal portion of the body portion <NUM>. In embodiments, the handle assembly <NUM> includes a stationary hand grip <NUM>, a firing trigger <NUM>, a rotation knob <NUM>, and an articulation lever <NUM>. The firing trigger <NUM> is actuable to move the tool assembly <NUM> between an unclamped position (<FIG>) and a clamped position (<FIG>) and to fire the stapling device <NUM>. The articulation lever <NUM> is rotatable to pivot the tool assembly <NUM> in relation to the body portion <NUM> about an axis transverse to the longitudinal axis "X". The rotation knob <NUM> pivotally supports the body portion <NUM> and the tool assembly <NUM> on the distal portion of the handle assembly <NUM>. Rotation of the rotation knob <NUM> in relation to the handle assembly <NUM> causes corresponding rotation of the body portion <NUM> and tool assembly <NUM> in relation to the handle assembly <NUM>.

For a detailed description of a handle assembly <NUM> including the firing trigger <NUM>, rotation knob <NUM>, and articulation lever <NUM>, and other components of the stapling device <NUM> including the body portion <NUM>, see <CIT> ("the '<NUM> Patent"). Although the presently disclosed tool assembly <NUM> is illustrated as part of a manually powered surgical stapling device <NUM>, it is also envisioned that the tool assembly <NUM> could be incorporated into a powered surgical stapling device such as disclosed in <CIT> and <CIT> and <CIT>.

Referring to <FIG> and <FIG>, the tool assembly <NUM> includes an anvil assembly <NUM> and a cartridge assembly <NUM>. A proximal portion of the anvil assembly <NUM> is pivotally coupled to a proximal portion of the cartridge assembly <NUM> by a pair of pivot members <NUM> such that the anvil assembly <NUM> is pivotal in relation to the cartridge assembly <NUM> to move the tool assembly <NUM> between an unclamped position (<FIG>) and a clamped position (<FIG>). It is envisioned that the cartridge assembly could also be pivotally supported to the anvil assembly <NUM>. Although not shown, the anvil assembly <NUM> includes a tissue contact surface that includes a plurality of staple deforming depressions. See, e.g., the anvil assembly disclosed in the '<NUM> Patent.

Referring to <FIG>, in some embodiments the cartridge assembly <NUM> includes a staple cartridge <NUM> that supports a plurality of staples <NUM> and a plurality of pushers <NUM>, a cartridge channel <NUM>, a staple cartridge support plate <NUM>, compression strips <NUM>, compression pads <NUM>, and an actuation sled <NUM>. It is envisioned that the cartridge assembly <NUM> may include only compression strips <NUM> or compression pads <NUM> as discussed in further detail below. The staple cartridge <NUM> includes a tissue contact surface <NUM> (<FIG>) that defines a central knife slot 106a, and a plurality of rows of laterally spaced staple retention slots 124a in the tissue contact surface <NUM>. In embodiments, the tissue contact surface <NUM> is stepped downwardly from the central knife slot 106a towards the outer edge of the staple cartridge <NUM>. Alternately, the tissue contact surface <NUM> of the staple cartridge <NUM> can be planar. Each staple retention slot 124a receives one of the staples <NUM> and a drive member 110a of a respective pusher <NUM>.

The support plate <NUM> of the cartridge assembly <NUM> is secured to an open, lower end of the staple cartridge <NUM> opposite to the tissue contact surface <NUM> by a snap-fit or other type connection. The support plate <NUM> covers the open lower end of the staple cartridge <NUM> to retain the staples <NUM> and pushers <NUM> within the staple cartridge <NUM>. The staple cartridge <NUM> also defines a plurality of longitudinal slots <NUM> (<FIG>). The longitudinal slots <NUM> communicate with the open, lower end of the staple cartridge <NUM> and the staple retention slots 124a to accommodate the staple pushers <NUM> and facilitate passage of the actuation sled <NUM> through the staple cartridge <NUM>. As known in the art, advancement of the actuation sled <NUM> through the staple cartridge <NUM> lifts the pushers <NUM> within the retention slots 124a to eject the staples <NUM> from the retention slots 124a. See, e.g., the '<NUM> Patent for a detailed description of the operation, and interaction of the actuation sled <NUM> and pushers <NUM>.

The staple cartridge <NUM> includes opposite sidewalls <NUM> and an upper wall <NUM> that defines the tissue contact surface <NUM> and the staple retention slots 124a. The upper wall <NUM> extends radially outward of the side walls <NUM> to define shoulders <NUM> (<FIG>). The staple cartridge <NUM> also includes protrusions <NUM> (<FIG>) that extend radially outwardly of each of the side walls <NUM> of the staple cartridge <NUM> and facilitate securement of the staple cartridge <NUM> within the cartridge channel <NUM>.

Referring also to <FIG>, the cartridge channel <NUM> includes a bottom wall <NUM> and spaced side walls <NUM> that together define a recess <NUM> that is dimensioned to receive the staple cartridge <NUM> and support plate <NUM> when the staple cartridge <NUM> and the support plate <NUM> are assembled. The bottom wall <NUM> defines a central longitudinal knife slot <NUM> that is aligned with the central knife slot 106a defined in the staple cartridge <NUM> as well as a longitudinal knife slot <NUM> defined by the support plate <NUM>. The knife slots 106a, <NUM> and <NUM> are dimensioned to facilitate passage of a drive member and knife (not shown) through the staple cartridge <NUM>. See, e.g., the '<NUM> Patent for a detailed description of an exemplary embodiment of a drive member and knife of a surgical stapling device.

Referring also to <FIG> and <FIG>, the compression strips <NUM> are formed of a compressible and/or elastic material such as such as elastomeric polymers. Elastic polymers include natural or synthetic rubbers, polyurethane, polyisoprene, polybutadiene, chloroprene, polyisobutylene, combinations thereof, or copolymers thereof. Each of the compression strips <NUM> includes a support portion <NUM> and a connecting portion <NUM>. In embodiments, the support portion <NUM> of each of the compression strips <NUM> defines a flat surface 156a that is positioned and configured to support the shoulders <NUM> of the staple cartridge <NUM> (<FIG>).

In embodiments, the spaced side walls <NUM> of the cartridge channel <NUM> each define a retention slot <NUM> (<FIG>) that is configured to receive a connecting portion <NUM> of the compression strips <NUM>. In embodiments, the retention slots <NUM> and the connecting portions <NUM> of the compression strips <NUM> have interlocking configurations which mate to securely fasten the compression strips <NUM> within the retention slots <NUM>. In some embodiments, the retention slots <NUM> and the connecting portion of the compression strips <NUM> each include have a dove-tail configuration although other interlocking configurations are envisioned, e.g., T-shaped slots, etc. The connecting portion <NUM> of the compression strips <NUM> are slidably received within the retention slots <NUM> to secure the compression strips <NUM> to the upper edges of the side walls <NUM> of the cartridge channel <NUM>. In addition, adhesives, welding, friction fitting, or the like can be used to secure the compression strips from moving axially within the slots <NUM>.

Referring briefly back to <FIG>, the side walls <NUM> of the cartridge channel <NUM> each include a plurality of notches <NUM>. The notches <NUM> provide access to ends of the retention slots <NUM> at a plurality of locations along the side walls <NUM> of the cartridge channel <NUM> to allow the connecting portions <NUM> of the compression strips <NUM> to be inserted into the retention slots <NUM> at multiple locations along the side walls <NUM>.

Referring again to <FIG>, <FIG>, in embodiments, the compression pads <NUM> are supported on the bottom wall <NUM> of the cartridge channel <NUM> between the bottom wall <NUM> and the support plate <NUM> of the cartridge assembly <NUM> (<FIG>) on opposite sides of the knife slot <NUM>. As discussed above in regard to the compression strips <NUM>, the compression pads <NUM> are formed of an elastic and/or compressible material and support the staple cartridge <NUM> to facilitate movement of the staple cartridge <NUM> in relation to the anvil assembly <NUM> during clamping and firing of the surgical stapling device <NUM>. In embodiments, the compression pads <NUM> include cut outs 118a that provide space for expansion of the compression pad <NUM> during firing. Although shown as being circular, the cut outs 118a can be of any configuration.

Referring to <FIG>, when thin tissue T1 is clamped between the tissue contact surface <NUM> of the staple cartridge <NUM> and the tissue contact surface 102a of the anvil assembly <NUM> and the surgical stapling device <NUM> is fired, the forces applied to the compression strips <NUM> and the compression pads <NUM> is minimal such that the compressible strips <NUM> and pads <NUM> undergo minimal deformation or compression. As such, very little movement of the staple cartridge <NUM> in relation to the anvil assembly <NUM> occurs. Thus, the staple cartridge <NUM> remains in close relation to the anvil assembly <NUM> and the staple 108a (<FIG>) undergoes substantial deformation.

Referring to <FIG>, when thicker tissue T2 is clamped between the tissue contact surface <NUM> of the staple cartridge <NUM> and the tissue contact surface 102a of the anvil assembly <NUM> and the surgical stapling device <NUM> is fired, the forces applied to the compression strips <NUM> and the compression pads <NUM> increases such that the compressible strips <NUM> and compression pads <NUM> undergo more substantial deformation or compression. As such, the staple cartridge <NUM> moves further downwardly away from the anvil assembly <NUM> to compensate for the thicker tissue T2. Thus, the staple cartridge <NUM> becomes spaced further from the anvil assembly <NUM> and the staple 108b undergoes more substantial deformation.

Referring to <FIG>, when even thicker tissue T3 is clamped between the tissue contact surface <NUM> of the staple cartridge <NUM> and the tissue contact surface 102a of the anvil assembly <NUM> and the surgical stapling device <NUM> is fired, the forces applied to the compression strips <NUM> and the compression pads <NUM> increases even further such that the compressible strips <NUM> and pads <NUM> undergo even more substantial deformation or compression. As such, the staple cartridge <NUM> moves further downwardly away from the anvil assembly <NUM> to compensate for the thicker tissue T3. Thus, the staple cartridge <NUM> becomes spaced even further from the anvil assembly <NUM> and the staple 108b undergoes even more substantial deformation.

Although the surgical stapling device <NUM> is illustrated to include both compression strips <NUM> and compression pads <NUM>, it is envisioned that the surgical stapling device need only include the strips <NUM> or the pads <NUM>.

<FIG> illustrate an alternate embodiment of the presently disclosed tool assembly of the stapling device <NUM> shown generally as <NUM>. Referring to <FIG>, the tool assembly <NUM> is similar to the tool assembly <NUM> (<FIG>) and, thus, only the differences will be described in detail in this specification. The tool assembly <NUM> includes an anvil assembly <NUM> and a cartridge assembly <NUM>. A proximal portion of the anvil assembly <NUM> is pivotally coupled to a proximal portion of the cartridge assembly <NUM> by pivot members <NUM> (only one pivot member is shown) such that the anvil assembly <NUM> is pivotal in relation to the cartridge assembly <NUM> to move the tool assembly <NUM> between an unclamped position (<FIG>) and a clamped position (<FIG>).

Referring also to <FIG> and <FIG>, the cartridge assembly <NUM> includes a staple cartridge <NUM> that supports a plurality of staples <NUM> (<FIG>) and a plurality of pushers <NUM> (<FIG>), a cartridge channel <NUM>, a staple cartridge support plate <NUM>, compression members such as compression strips <NUM>, and an actuation sled (not shown). The staple cartridge <NUM> includes a tissue contact surface <NUM> that defines a central knife slot 206a and a plurality of rows of laterally spaced staple retention slots 224a. In embodiments, the tissue contact surface <NUM> is stepped downwardly from the central knife slot 206a towards the outer edge of the staple cartridge <NUM> (<FIG>). Alternately, the tissue contact surface <NUM> of the staple cartridge <NUM> can be planar. Each staple retention slot 224a receives one of the staples <NUM> (<FIG>) and a drive member 210a of a respective pusher <NUM>.

Referring to <FIG>, the support plate <NUM> of the cartridge assembly <NUM> is secured to an open, lower end of the staple cartridge <NUM> opposite to the tissue contact surface <NUM> by a snap-fit or other type connection. The support plate <NUM> covers the open lower end of the staple cartridge <NUM> to retain the staples <NUM> (<FIG>) and pushers <NUM> (<FIG>) within the staple cartridge <NUM>. In embodiments, the support plate <NUM> defines a substantially U-shaped channel 214a that receives the staple cartridge <NUM> and includes a bottom wall <NUM>, and spaced side walls <NUM>. The end of each of the side walls <NUM> opposite the bottom wall <NUM> includes a compression strip support flange <NUM>. The support flanges <NUM> include a base 254a and a side wall 254b. The compression strips <NUM> are supported on the base 254a of a respective one of the support flanges <NUM> such that the side wall 254b of each support flange <NUM> is positioned alongside the compression strip <NUM>.

The staple cartridge <NUM> also defines a plurality of longitudinal slots <NUM> (<FIG>). The longitudinal slots <NUM> communicate with the open, lower end of the staple cartridge <NUM> and the staple retention slots 224a to accommodate drive members 210a of the staple pushers <NUM> and allow passage of the actuation sled (not shown) through the staple cartridge <NUM>. As known in the art, advancement of the actuation sled through the staple cartridge <NUM> lifts the pushers <NUM> within the retention slots 224a to eject the staples <NUM> from the retention slots 224a. See, e.g., the '<NUM> Patent for a detailed description of the operation, and interaction of the actuation sled <NUM> and pushers <NUM>.

Referring also to <FIG>, the staple cartridge <NUM> includes opposite sidewalls <NUM> and an upper wall <NUM> that defines the tissue contact surface <NUM> and the staple retention slots 224a. The upper wall <NUM> extends radially outward of the side walls <NUM> to define shoulders <NUM> (<FIG>). The side walls <NUM> of the staple cartridge <NUM> include protrusions <NUM> and <NUM> that extend radially outwardly of each of the side walls <NUM>. The protrusions <NUM> are received within cutouts <NUM> (<FIG>) defined in the cartridge channel <NUM> to align the staple cartridge <NUM> within the cartridge channel <NUM>. The protrusions <NUM> are received within openings <NUM> (<FIG>) defined within the support plate <NUM> to secure the staple cartridge <NUM> within the support plate <NUM>.

The cartridge channel <NUM> includes a bottom wall <NUM> and spaced side walls <NUM> that together define a recess <NUM> that is dimensioned to receive the staple cartridge <NUM> and support plate <NUM> when the staple cartridge <NUM> and the support plate <NUM> are assembled. The bottom wall <NUM> defines a central longitudinal knife slot <NUM> that is aligned with the central knife slot 206a defined in the staple cartridge <NUM> as well as a longitudinal knife slot <NUM> defined in the support plate <NUM>. The knife slots 206a, <NUM> and <NUM> are dimensioned to facilitate passage of a drive member <NUM> (<FIG>) that supports a knife <NUM> through the staple cartridge <NUM>. See, e.g., the '<NUM> Patent for a detailed description of an exemplary embodiment of a drive member and knife of a surgical stapling device.

In embodiments, the spaced side walls <NUM> of the cartridge channel <NUM> have a first end positioned adjacent the bottom wall <NUM> and a second end that defines a support surface <NUM> (<FIG>) that is configured to support the base 254a of the support flanges <NUM> of the support plate <NUM>. In embodiments, the support surfaces <NUM> of the cartridge channel <NUM> are bounded by a raised longitudinal rail <NUM> that extends along at least a portion of the length of the support surfaces <NUM>.

In some embodiments, the compression strips <NUM> have a body <NUM> that has an elongated upper portion <NUM> and a lower portion defined by a plurality of alternating fingers <NUM> and grooves <NUM>. The elongated upper portion <NUM> includes an upper surface 272a that is configured to support the shoulders <NUM> of the staple cartridge <NUM> (<FIG>). The lower portion of the body <NUM> of the compression strips <NUM> including the alternating fingers <NUM> is supported on the base 254a of the support flange <NUM> of the support plate <NUM>. The provision of alternating grooves <NUM> improves the compressibility of the compression strips <NUM>.

As discussed above in regard to the compression strips <NUM> (<FIG>), the compression strips <NUM> are formed of a compressible and/or elastic material such as an elastomeric polymer. Suitable elastic polymers include natural or synthetic rubbers, polyurethanes, polyisoprenes, polybutadienes, chloroprenes, polyisobutylenes, combinations thereof, or copolymers thereof.

Referring to <FIG>, when the tool assembly <NUM> is assembled, the staple cartridge <NUM> is supported within the U-shaped channel 214a of the support plate <NUM> with the compression strip <NUM> clamped between the base 254a of the support flange <NUM> of the support plate <NUM> and the shoulders <NUM> of the staple cartridge <NUM>.

The compression strips <NUM> function in a substantially similar manner to the compression strips <NUM> (<FIG>) described above. More specifically, when tissue is clamped between the tissue contact surface <NUM> of the staple cartridge <NUM> and the tissue contact surface 202a of the anvil assembly <NUM> and the surgical stapling device <NUM> is fired, the forces applied to the compression strips <NUM> undergo deformation or compression. As discussed above, the amount of deformation will depend upon the thickness of the tissue being treated.

Referring to <FIG>, the cartridge assembly <NUM> may include staple cartridges <NUM> having a variety of sizes that may include a variety of different staple types and sizes. For example, as described above, the staple cartridge <NUM> may include a tissue contact surface <NUM> that is stepped downwardly from the central knife slot 206a towards the outer edge of the staple cartridge <NUM>. Alternately, the tissue contact surface <NUM> of the staple cartridge <NUM> can be planar. In embodiments, the inner row and outer rows of staples <NUM> may vary in size to vary the degree of tissue compression applied to tissue outwardly of the central knife slot 206a as is known in the art. In addition, the staples <NUM> may include universal staples <NUM> that have a backspan 208a that has a thickness that is variable based in part on the thickness of the tissue being compressed to accommodate tissues of different thicknesses.

Referring to <FIG>, an alternate embodiment of support plate of the cartridge assembly <NUM> is shown as support plate <NUM>. The support plate <NUM> includes compression members in the form of leaf springs <NUM>. In embodiments, the leaf springs <NUM> are supported on a base 354a of support flanges <NUM> of the staple cartridge support plate <NUM>. In certain embodiments, the leaf springs <NUM> (<FIG>) define a longitudinal axis that is parallel to the longitudinal axis "X" of the staple cartridge support plate <NUM> and are secured to the support flanges <NUM> by welding. Alternately, other fastening techniques can be used to secure the leaf springs <NUM> to the staple cartridge support plate <NUM>.

Referring to <FIG>, in another embodiment of the presently disclosed support plate shown generally as support plate <NUM>, leaf springs <NUM> are formed integrally with the support plate <NUM> and are spaced longitudinally along spaced side walls <NUM> of the support plate <NUM>. In embodiments, the leaf springs <NUM> have a substantially C-shaped transverse cross-section with a lower end that defines the support flange <NUM>.

In the embodiments of the support plates <NUM> and <NUM>, the shoulders <NUM> (<FIG>) of the staple cartridge <NUM> rest atop the leaf springs <NUM> and <NUM>. When tissue is compressed between the anvil assembly <NUM>, <NUM>, the leaf springs <NUM> and <NUM> function a manner similar to the compression members <NUM> described above. As such, no further description will be described herein.

Claim 1:
A cartridge assembly (<NUM>; <NUM>) comprising:
a cartridge channel (<NUM>; <NUM>) including a bottom wall (<NUM>:<NUM>) and side walls (<NUM>: <NUM>:<NUM>) defining a recess, each of the side walls having a first end secured to the bottom wall and a second end spaced from the bottom wall, the second end of each of the side walls defining a support surface;
a staple cartridge (<NUM>;<NUM>) defining a longitudinal axis and including an upper wall defining a tissue contact surface and side walls, the upper wall extending radially outward of the side walls of the staple cartridge to define a longitudinally extending shoulder, the cartridge assembly further including a support plate secured to the staple cartridge wherein the support plate includes a bottom wall, and first and second side walls that define a U-shaped channel dimensioned to receive the staple cartridge, each of the first and the second side walls of the support plate having a first end connected to the bottom wall of the support plate and a second end having a support flange wherein the support flanges are supported on the support surface of the cartridge channel ; and
a compression member (<NUM>; <NUM>) supported on each of the support flanges of the support plate each of the compression members being positioned between one of the shoulders of the staple cartridge and one of the support flange of the support plate, each of the compression members including a body having an elongated upper portion positioned to engage the shoulders of the staple cartridge and a lower portion defined by a plurality of spaced fingers and grooves,
the staple cartridge being dimensioned to be received within the recess of the cartridge channel such that the shoulders of the cartridge rest atop the elongated upper portion of each of the compression members (<NUM>; <NUM>).