USRE38708E1 - Disposable loading unit for surgical stapler - Google Patents

Abstract

A disposable loading unit is disclosed for use in conjunction with a surgical stapling apparatus configured to sequentially apply a plurality of surgical fasteners to body tissue. The apparatus includes an actuation assembly for effectuating a fastener applying operation, and a housing for receiving and releasably supporting the disposable loading unit. The disposable loading unit includes a staple cartridge body having a longitudinal pathway extending therethrough and a plurality of spaced apart retention slots defined therein each supporting a respective surgical fastener, a plurality of fastener ejection members disposed adjacent the plurality of spaced apart retention slots and communicating with the longitudinal pathway, and an actuator supported within the staple cartridge body and configured to engage the actuation assembly of the apparatus and translate through the longitudinal pathway to contact the fastener ejection members and thereby sequentially eject the surgical fasteners from their respective retention slots.

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Description

This application is a continuation of U.S. application Ser. No. 08/501,197 filed Jul. 11, 1995, now U.S. Pat. No. 5,752,644.

BACKGROUND

1. Technical Field

This invention relates to a disposable loading unit for a surgical stapler, and more particularly, to a disposable loading unit for an apparatus configured to sequentially apply a plurality of surgical fasteners to body tissue and optionally incise the fastened tissue.

2. Background of Related Art

Surgical devices wherein tissue is first grasped or clamped between opposing jaw structure and then joined by surgical fasteners are well known in the art. In some instruments a knife is provided to cut the tissue which has been joined by the fasteners. The fasteners are typically in the form of surgical staples but two part polymeric fasteners can also be utilized.

Instruments for this purpose can include two elongated members which are respectively used to capture or clamp tissue. Typically, one of the members carries a staple cartridge which houses a plurality of staples arranged in at least two lateral rows while the other member has an anvil that defines a surface for forming the staple legs as the staples are driven from the staple cartridge. Generally, the stapling operation is effected by cam bars that travel longitudinally through the staple cartridge, with the cam bars acting upon staple pushers to sequentially eject the staples from the staple cartridge. A knife can travel between the staple rows to longitudinally cut and/or open the stapled tissue between the rows of staples. Such instruments are disclosed, for example, in U.S. Pat. No. 3,079,606 and U.S. Pat. No. 3,490,675.

A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a double row of staples on each side of the incision. This is accomplished by providing a disposable loading unit in which a cam member moves through an elongate guide path between two sets of staggered staple carrying grooves. Staple drive members are located within the grooves and are positioned in such a manner so as to be contacted by the longitudinally moving cam to effect ejection of the staples. Other examples of such staplers are disclosed in U.S. Pat. Nos. 4,429,695 and 5,065,929.

Each of the instruments described above were designed for use in conventional surgical procedures wherein surgeons have direct manual access to the operative site. However, in endoscopic or laproscopic procedures, surgery is performed through a small incision or through a narrow cannula inserted through small entrance wounds in the skin. In order to address the specific needs of endoscopic and/or laparoscopic surgical procedures, endoscopic surgical stapling devices have been developed and are disclosed in, for example, U.S. Pat. Nos. B5,040,715 (Green, et al.); 5,307,976 (Olson, et al.); 5,312,023 (Green, et al.); 5,318,221 (Green, et al.); 5,326,013 (Green, et al.); and 5,332,142 (Robinson et al.).

U.S. Surgical, the assignee of the present application, has manufactured and marketed endoscopic stapling instruments, such as the Multifire ENDO GIA* 30 and Multifire ENDO GIA* 60 instruments, for several years. These instruments have provided significant clinical benefits. Nonetheless, improvements are possible, for example, by reducing the cost and complexity of manufacture and/or reducing the amount of material discarded at the conclusion of a surgical procedure. In making any such improvements, it would be highly desirable not to sacrifice any of the important benefits of the MULTIFIRE ENDO GIA* 30 and 60 instruments as compared to other commercially available products, e.g., the endoscopic stapling instruments manufactured and marketed by Ethicon, Inc. For example, any improvement should advantageously provide a fresh knife blade for each firing of the instrument and ensure that the disposable loading unit is securely retained in the stapling instrument unless and until the operating team chooses to remove it. These advantages have historically been found in the U.S. Surgical instruments, but not in the Ethicon instruments.

Therefore, a need exists for a disposable loading unit that exhibits all of the benefits of the present assignee's commercially available instruments while also reducing the cost and complexity of manufacture and/or reducing the amount of material discarded at the conclusion of a surgical procedure.

SUMMARY

The subject application is directed to a disposable loading unit for a surgical stapling apparatus configured to sequentially apply a plurality of surgical fasteners to body tissue during a surgical procedure. The apparatus with which the disposable loading unit is associated includes an actuation assembly for effectuating a fastener applying operation, and a housing mountable to a surgical stapling instrument for receiving and detachably supporting the disposable loading unit. The housing may be removably mounted to the stapler apparatus.

The disposable loading unit includes a staple cartridge body having a longitudinal pathway extending therethrough and a plurality of spaced apart retention slots defined therein each supporting a respective surgical fastener, a plurality of fastener ejection members disposed within the plurality of spaced apart retention slots and communicating with the longitudinal pathway. The disposable loading unit also includes an actuator supported within the staple cartridge body and configured to engage the actuation assembly of the apparatus and translate through the longitudinal pathway to contact the fastener ejection members and thereby sequentially eject the surgical fasteners from their respective retention slots.

The actuator includes a base portion and at least two upstanding parallel cam plates each preferably defining an angled leading edge for contacting the fastener ejection members. In one embodiment, the leading edge of each cam plate is configured to controllably deform as the actuator translates through the staple cartridge body. Alternatively, each of the cam plates is configured to be reduced in size or mass as the actuator translates through the staple cartridge body. In a further alternative embodiment, the cam plates can be fabricated from a rigid material that does not significantly deform during fastener ejection.

The disposable loading unit can also include an optical cutting member that is configured to translate through the staple cartridge body in association with the actuator to form an incision in the stapled body tissue. In operation, the cutting member intersects the tissue contacting plane during its translation through the staple cartridge body, and is moved out of intersection with the tissue contacting plane at the conclusion of a stapling operation. The cutting member is single use only, thereby ensuring maximum sharpness for each firing.

In a preferred embodiment of the disposable loading unit, structure is associated with the disposable loading unit for releasably engaging the housing to inhibit movement of the disposable loading unit within the housing during a fastener applying operation. Structure associated with the disposable loading unit for releasably engaging the housing includes a pair of elongate struts dimensioned and configured to engage the opposed side walls of the housing to inhibit lateral movement of the disposable loading unit. A pair of opposed detents which are dimensioned and configured to engage a pair of corresponding notches defined in the opposed side walls of the housing can also be provided to inhibit longitudinal movement of the disposable loading unit. Furthermore, a pair of opposed outwardly extending protuberances which are dimensioned and configured to engage a pair of corresponding indentations defined in the opposed side walls of the housing can be provided to inhibit vertical movement of the disposable loading unit. The disposable loading unit can also include a pair of spaced apart wings which extend from a proximal end of the staple cartridge body and include angled guide surfaces for guiding the disposable loading unit into the housing during assembly.

In another preferred embodiment of the disposable loading unit, at least one camming surface is provided for facilitating engagement of the actuator and the actuation assembly of the surgical apparatus to enable the performance of a fastener applying operation. Preferably, a first cam wing depends from a proximal end of the staple cartridge body and defines a first angled cam surface, and a second cam wing depends from a proximal end of the actuator and defines a second angled cam surface. When the first and second angled cam surfaces are aligned, the actuation assembly of the stapler can engage the actuator and drive it through the staple cartridge body. However, when the angled cam surfaces are spaced from one another, i.e. when the actuator is at the distal end of the staple cartridge body, the actuation assembly will be unable to engage the actuator and the apparatus will be rendered inoperative until the used disposable loading unit is removed from the apparatus.

In another preferred embodiment, structure is provided on the fastener actuator and the staple cartridge body for retaining the actuator at the distal end of the staple cartridge body after the fasteners have been fired.

Advantageously, the disposable loading unit disclosed herein provides a replaceable unit which preserves the advantage of a disposable loading unit over a replaceable staple cartridge; namely, providing new cam plates and/or knife with each disposable loading unit.

Further features of the surgical apparatus will become more readily apparent to those skilled in the art from the following detailed description of the invention taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various preferred embodiments of the disposable loading unit of the subject application will be described hereinbelow with reference to the drawings wherein:

FIG. 1 is a perspective view of a surgical stapling apparatus which employs a disposable loading unit constructed in accordance with a preferred embodiment;

FIG. 2 is a perspective view of a disposable loading unit constructed in accordance with a preferred embodiment and illustrating the position of the actuator prior to a fastener applying operation;

FIGS. 3-5 are perspective views of the disposable loading unit ofFIG. 2, during a fastener applying operation as the actuator translates through the staple cartridge body to sequentially eject surgical fasteners from the staple cartridge and drive them against the anvil member to be formed thereby;

FIG. 6 is an exploded perspective view of another disposable loading unit constructed in accordance with a preferred embodiment that has a cutting blade associated with the actuator;

FIG. 6A is an enlarged view of the indicated area of detail ofFIG. 6;

FIG. 7 is a top plan view of the disposable loading unit ofFIG. 6;

FIG. 8 is a side elevational view in cross-section taken alongline8—8 ofFIG. 7 with the actuation disposed in a proximal position within the staple cartridge body;

FIG. 9 is a side elevational view of the disposable loading unit ofFIG. 8, with the actuator disposed in a distal position prior to the cutting blade being moved out of intersection with the tissue contacting surface of the staple cartridge body;

FIGS. 10A and 10B are perspective views of the actuator and the cutting blade carrier in an orientation corresponding to their respective position shown inFIG. 9;

FIG. 11A is a side elevational view in cross-section of the distal portion of the disposable loading unit as the cutting blade is moved out of intersection with the tissue contacting surface of the staple cartridge body;

FIG. 11B is a perspective view of the actuator and cutting blade carrier in an orientation corresponding to their respective position shown inFIG. 11A;

FIG. 12A is a side elevational view in cross-section of the distal portion of the disposable loading unit with the cutting blade moved out of intersection with the tissue contacting surface of the staple cartridge body;

FIG. 12B is a perspective view of the actuator and the cutting blade carrier in an orientation corresponding to their respective positions shown inFIG. 12A;

FIG. 13 is a cross-sectional view of the disposable loading unit taken alongline13—13 ofFIG. 12A;

FIG. 14 is a cross-sectional view of the disposable loading unit taken alongline14—14 ofFIG. 13 illustrating the actuator in a locked position at the distal end of the disposable loading unit;

FIG. 15 is a side elevational view in cross-section of a disposable loading unit and housing constructed in accordance with a preferred embodiment prior to a fastening procedure wherein the actuator is disposed in a proximal position, spaced from the cutting blade carrier, and partially engaged by an actuation channel;

FIG. 16 is a side elevational view in cross-section of the disposable loading unit illustrated inFIG. 15 with the actuator fully engaged by the actuation channel;

FIG. 17 is a top plan view of the disposable loading unit, housing, and actuation channel;

FIG. 18 is a side elevational view in cross-section taken alongline18—18 ofFIG. 17 illustrating the actuator and cutting blade in a locked position at the distal end of the staple cartridge body, and the actuation channel disposed in a retracted and elevated position adjacent the proximal end of the disposable loading unit;

FIG. 19 is a side elevational view of the disposable loading unit illustrated inFIG. 18 wherein the actuation channel is engaged with a camming member extending from the rear end portion of the staple cartridge body;

FIG. 20 is a side elevational view of the disposable loading unit illustrated inFIG. 18 wherein a distal end of the actuation channel is in abutment with a proximal end portion of the staple cartridge body;

FIG. 21 is an exploded perspective view of a disposable loading unit and a housing constructed in accordance with a preferred embodiment illustrating structures for inhibiting movement of the disposable loading unit relative to the housing during a fastening operation;

FIG. 21A is an enlarged view of the indicated area of detail ofFIG. 21;

FIG. 21B is an enlarged view of the indicated area of detail ofFIG. 21;

FIG. 22 is a perspective view of the disposable loading unit and the housing illustrated inFIG. 21 in an assembled condition; and

FIGS. 23A-23C are perspective views of another actuator constructed in accordance with a preferred embodiment which has staggered cam plates to balance fastener driving forces during a fastening operation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the drawings and in the description which follows, the term “proximal”, as is traditional, will refer to the end of the stapling apparatus which is closed to the operator, while the term “distal” will refer to the end of the apparatus which is furthest from the operator.

The stapling apparatus with which the disposable loading unit of the present disclosure is associated shall be discussed in terms of both conventional and endoscopic procedures. However, use herein of terms such as “endoscopic”, “endoscopically”, and “endoscopic portion”, among others, should not be construed to limit the present apparatus for use only in an endoscopic environment. To the contrary, it is believed that the apparatus and disposable loading unit described herein may find use in procedures wherein access is limited to a small incision including but not limited to arthroscopic and/or laparoscopic procedures, and in other non-endoscopic procedures.

Referring now to the drawings wherein like reference numerals identify similar structural elements of the subject apparatus, there is illustrated inFIG. 1 a surgical stapling apparatus designated generally byreference numeral10.Stapling apparatus10 is configured for utilization during laparoscopic and endoscopic surgical procedures and includes ahandle assembly12, anelongated body portion14, and afastener applying assembly16 which is associated with a distal end ofelongated portion14.Fastener applying assembly16 includes afastener containing portion18 and ananvil member20. Handleassembly12 includes a clampinghandle22 for effectuating approximation ofanvil member20 andfastener containing portion18, and anactuation handle24 for effectuating a fastener applying operation. A stapling apparatus of this type is disclosed in commonly assigned U.S. Pat. No. 5,318,221, the disclosure of which is herein incorporated by reference.

Referring now toFIGS. 2-5A, thefastener containing portion18 offastener applying assembly16 includes ahousing28 dimensioned and configured to receive and detachably support a disposable loading unit. The disposable loading unit includes astaple cartridge body30 having alongitudinal pathway32 extending therethrough, and a plurality of spaced apartfastener retention slots36 formed therein. Eachretention slot36 is dimensioned and configured to support a respectivesurgical fastener35 as shown. A plurality offastener ejectors40 are also supported within thestaple cartridge body30 and are each associated withsurgical fasteners35. As shown,ejectors40 are each preferably associated with three surgical fasteners. However, other quantities of surgical fasteners can be associated therewith, such as one or two fasteners per ejector. Eachejector40 has an angledcamming surface42 which is dimensioned and configured to engage anactuator50, included in the disposable loading unit, as the actuator translates throughpathway32 under the influence of an actuation shaft orchannel44 of the stapling apparatus.Actuation channel44 is configured to translate through thebody portion14 ofsurgical apparatus10 and is controlled through manipulation of the actuation handle24 ofhandle assembly12.

As best seen inFIGS. 3 and 3A,actuator50 includes abase portion52 and four spaced apartupstanding cam plates54. Eachcam plate54 has an angledcamming surface56 for sequentially engaging thecamming surface42 of eachfastener ejector40 asactuator50 translates throughpathway32. Once contacted or engaged byactuator50, eachejector40 is driven vertically in the direction indicated by arrow “Y”, urging threeadjacent fasteners35 from theirrespective retention slots36 to be driven and formed against the fastener forming surface of anvil member20 (shown in phantom).

Referring toFIGS. 3-5A,cam plates54 can be formed of a material such as plastic, or a fibrous composite, which deforms asactuator50 translates distally and engagesfastener ejectors40. More particularly,cam plates54 are configured to reduce in mass or decrease in size asactuator50 is driven throughstaple cartridge body30 in the direction indicated by arrow “X₀”. The reduction in mass and the decrease in size results from the forced frictional contact between the camming surfaces56 ofcam plates54 and the camming surfaces42 offastener ejectors40 under the influence ofactuation shaft44. To compensate for the change in size ofactuator50,ejectors40 can gradually increase in vertical height to maintain consistent staple formation.Cam plates54 can also be fabricated from a relatively non-deformable material such as, for example, stainless steel which will not significantly deform.

Following a fastener applying procedure illustrated inFIGS. 3-5A, the disposable loading unit includingstaple cartridge body30 together with the actuatedfastener ejectors40 and the displacedactuator50, is removed fromhousing28, discarded, and replaced with a new fully loaded disposable loading unit that includes fasteners, ejectors, and a new actuator.

Referring now toFIGS. 6 and 6A, there is illustrated an alternativedisposable loading unit100 constructed in accordance with a preferred embodiment. The disposable loading unit is received inhousing128 and includes analternative actuator110.Actuator110 includes abase portion102 having an angled leadingedge102a, and four spaced apartupstanding cam plates104 each defining arespective camming surface106 in angular alignment with leadingedge102a.Base portion102 includes adeflectable beam section108 which supports anupstanding shank112. Aslot114 is formed inshank112 for receiving and engaging a correspondingly dimensioned and configuredflange115 associated withblade carrier116 asactuator110 beings its translation throughstaple cartridge body130.Blade carrier116 supportsknife blade118 which incises stapled body tissue asactuator110 translates throughstaple cartridge body130 during a fastener applying operation.

As best seen inFIG. 7, alongitudinal slot125 is formed instaple cartridge body130 for accommodating the longitudinal translation ofknife blade118 as it intersects thetissue contacting surface120 ofstaple cartridge body130 to engage and form an incision in stapled body tissue. As knife baled118 approaches the distal end ofpathway132, it is advantageously moved out of the plane defined bytissue contacting surface120, to prevent injurious contact therewith during removal of the disposable loading unit fromhousing128. Alternatively, it is contemplated that the disposable loading unit can further includehousing128, such that the disposable loading unit includes the staple cartridge, actuator and housing.

Referring toFIG. 9, the advantageous displacement ofknife blade118 is caused by the interaction of an angled cam surface122 (FIG. 8) formed at a leading edge ofblade support116 and anangled abutment surface124 formed at the distal end ofstaple cartridge body130. During a fastening operation, whencam surface122 initially engagesabutment surface124, thebeam section108 ofactuator110 is in substantially planar alignment withbase portion102, as illustrated inFIGS. 10A and 10B. Asactuator110 continues to translate distally withinstaple cartridge body130, further interaction betweencam surface122 andabutment surface124 causesbeam section108 to deflect angularly away frombase portion102. Preferably,beam section108 is caused to deflect sufficiently so that theentire knife blade118 is withdrawn intostaple cartridge body130 beneathtissue contacting surface120, as illustrated inFIGS. 11A-11B. During the angular deflection ofbeam section108, the forces generated by the interaction ofcam surface122 andabutment surface124 can be counteracted by a pair ofopposed support wings134a and134b which depend proximally fromactuator110 and contact the floor ofhousing128.Support wings134a and b are preferably formed monolithically withactuator110.

Referring toFIGS. 13 and 14, whenactuator110 reaches its distal-most position withinpathway132 ofstaple cartridge body130, a plurality ofangular ridges136 formed onbase portion102 are engaged by a plurality of correspondingangular teeth138 formed onstaple cartridge body130. At such a time,actuator110 is fixedly retained at the distal end of thestaple cartridge body130 and cannot be withdrawn therefrom.Ridges136 andteeth138 prevent the actuator and associated knife blade from becoming dislodging from the staple cartridge body after it has been discarded. Of course,ridges136 andteeth138 can be interchanged or other structures to prevent dislodgment of the actuator can be used.

Referring now toFIGS. 15 and 16, there is illustrated the actuator mechanism for effecting the longitudinal translation ofactuator110 during a fastening operation, and for preventing the actuation ofsurgical apparatus10 afteractuator110 has been driven throughstaple cartridge body130. The actuation mechanism includes anelongated actuation channel150 that translates in a longitudinal direction in response to manipulation of actuation handle24 (See FIG.1).Actuation channel150 is preferably U-shaped and is configured to interact with afirst camming wing152 extending integrally from the proximal end ofstaple cartridge body130, and asecond camming wing154 extending integrally from the proximal end ofactuator110.

As illustrated inFIG. 15, at the beginning of a fastening operation, asactuation channel150 translates distally, it initially encounters thefirst camming wing152 ofstaple cartridge body130.Camming wing152 guideschannel150 toward thesecond camming wing154 ofactuator110, against the bias of anintegral leaf spring156 extending fromactuation channel150. Alternatively, the channel could be cambered to eliminate the need forleaf spring156. Asactuation channel150 continues to travel distally, guided by cammingwing152, it encounters thesecond camming wing154 and is guided into contact with a proximal portion ofbase portion102 ofactuator110, as illustrated in FIG.16. Thereafter, continued distal translation ofactuation channel150 drives actuator110 throughstaple cartridge body130 to sequentially eject surgical fasteners therefrom, as illustrated, for example, inFIGS. 3-5.

Referring toFIGS. 17 and 18, at the conclusion of a fastening operation,actuator110 is disposed within the distal end portion ofstaple cartridge body130,knife blade118 is moved out of intersection withtissue contacting surface120, andactuation channel150 is retracted proximally to the position illustrated in FIG.18. In this position,actuation channel150 is biased into engagement with thefirst camming wing152 byleaf spring156, or by its natural camber. If, at such a time,actuation channel150 is driven distally, it will interact with thefirst camming wing152, as shown inFIG. 19, but will be unable to interact with thesecond camming wing154 ofactuator110. Thus, as illustrated inFIG. 20, the distal end ofactuation channel150 will abut and engage the proximal end ofstaple cartridge body130 and will be prevented from translating distally.Actuation channel150 will remain inoperative until the disposable loading unit from which fasteners have been expelled is removed fromhousing128 and replaced with a new disposable loading unit having an actuator and knife disposed in a proximal position. As will be appreciated, if less than all fasteners are ejected from the staple cartridge and actuation handle24 is released by the operator, the channel will return to the position shown in FIG.18 and will be unable to re-enter the staple cartridge body. This desirably prevents re-use of a partially fired staple cartridge.

Referring now toFIGS. 21,21A,21B, and22, an alternative disposable loading unit and housing constructed in accordance with a preferred embodiment are illustrated and are designated byreference numerals200 and210 respectively.Disposable loading unit200 andhousing210 are provided with cooperative structures which function to releasably securedisposable loading unit200 withinhousing210 and inhibit lateral, longitudinal, and elevational movement of the disposable loading unit during a stapling procedure. In particular,disposable loading unit200 includes astaple cartridge body230 having opposedlateral struts232a and232b which are formed monolithically therewith and which extend substantially along the length thereof and define channels233a (not shown) and233b.Struts232a and232b releasably engage the upper portion ofopposed side walls242a and242b ofhousing210 and inhibit movement of the disposable loading unit withinhousing210.

A pair of opposed detents234a (not shown) and234b are formed adjacent the distal end of thestaple cartridge230 for engaging a pair ofcorresponding notches244a and244b formed in theopposed side walls242a and242b ofhousing210. The notches and the detents are configured to lockingly engage with each other and inhibit longitudinal or distal-to-proximal movement of the disposable loading unit withinhousing210. In addition, a pair of outwardly depending protuberances236a (not shown) and236b are formed onstaple cartridge230 for engaging a pair of correspondingdepressions246a and246b formed in theopposed side walls242a and242b ofhousing210. The protuberances and depressions are configured to inhibit vertical or elevational movement of the disposable loading unit withinhousing210.

Cartridge body230 further includes a pair of proximally extendingguide wings238a and238b which serve to guidestaple cartridge body230 intohousing210 during assembly. More particularly, guidewings238a and238b have respective angled guide surfaces which are dimensioned and configured to cause the proximal end ofstaple cartridge body230 to slide relative to the floor242c ofhousing210 as the staple cartridge body is engaged beneath a pair of inwardly extendinghousing projections248a and248b (FIG.22).

Referring now toFIGS. 23a-23c, there is illustrated another actuator constructed in accordance with an alternative embodiment and designated generally byreference numeral310.Actuator310 is configured to translate throughstaple cartridge body230 in the same manner asactuator110 to sequentially eject a plurality of surgical fasteners therefrom, and includes abase portion312, a first set ofupstanding cam plates314a and314b, and a second set ofupstanding cam plates316a and316b.Cam plates314a and314b preferably have generally flattop portions320 and have aleading edge322 disposed distal of bothbase portion312 andleading edge324 ofcam plates314a and314b. The first set of cam plates are advantageously offset or staggered from the second set of cam plates to balance the fastener driving forces generated within the disposable loading unit during a fastening operation.

As used in the claims, “securing means” is intended to refer toridges136 andteeth138 formed onactuator110 andpathway132, respectively, and equivalents thereof.

As used in the claims, “camming means” is intended to refer to the camming wings of the actuator and equivalents thereof.

Although the foregoing description contains many specifics with respect to preferred embodiments, it will be readily apparent to those having ordinary skill in the art that changes and modifications may be made thereto without departing from the spirit or scope of the subject invention as defined by the appended claims. By way of example only, it is contemplated that the housing can be permanently mounted to the stapling apparatus with the disposable loading unit removably mounted thereto. Alternatively, the disposable loading unit can further include the housing, such that the housing is removably mounted to the stapling apparatus. It also is contemplated that greater or fewer cam plates can be included on the actuator.

Claims (11)

1. A disposable loading unit for a surgical stapling apparatus comprising:

a) a staple cartridge body having a longitudinal pathway extending therethrough and a plurality of spaced apart retention slots defined therein, each supporting a respective surgical fastener;

b) a plurality of fastener ejection members disposed adjacent the plurality of spaced apart retention slots and communicating with the longitudinal pathway;

c) an actuator at least partially disposed within the staple cartridge body and configured to be translated through the longitudinal pathway to contact the fastener ejection members and thereby sequentially eject the surgical fasteners from their respective retention slots, the actuator including a base portion defining a plane and having at least two upstanding parallel cam plates each defining an angled leading edge for contacting the fastener ejection members;

d) a cutting member configured to translate through the staple cartridge body, the cutting member having a blade and a blade support, the blade support including a camming surface spaced from the blade configured to interact with an abutment surface defined within a distal end portion of the staple cartridge body, wherein the staple cartridge body includes a planar tissue contacting surface through which extends a linear slot to accommodate translation of the cutting member, the planar tissue contacting surface defining a tissue contacting plane, the cutting member intersecting the tissue contacting plane during the translation thereof, and moving out of intersection with the tissue contacting plane when the camming surface of the cutting member contacts the abutment surface of the staple cartridge body.

2. A disposable loading unit according toclaim 1, wherein the cutting member is pivotably supported at least partially within the staple cartridge body.

3. A disposable loading unit according toclaim 2, wherein the cutting member is pivotably supported by the actuator about a pivot axis located distally of the blade.

4. A disposable loading unit for a surgical stapling apparatus comprising:

a) a staple cartridge body having a longitudinal pathway extending therethrough and at least two rows of spaced apart retention slots defined therein, each slot supporting a respective surgical fastener, the staple cartridge body defining a planar tissue contacting surface having a linear slot extending therethrough, the staple cartridge body further defining an abutment surface formed near a distal end thereof;

b) a plurality of fastener ejection members disposed adjacent the plurality of spaced apart retention slots and communicating with the longitudinal pathway;

c) an actuator at least partially disposed within the staple cartridge body, the actuator having:

i) a base portion; and

ii) at least two upstanding parallel cam plates extending from a base portion, each of the at least two cam plates defining an angled leading edge, such that the angled leading edges are longitudinally aligned with the at least two rows of spaced apart retention slots so as to contact the fastener ejection members upon translational movement of the actuator through the longitudinal pathway and to thereby sequentially eject the surgical fasteners from their respective retention slots; and

d) a cutting member pivotably mounted with respect to the actuator and translatably slidable with the actuator in the linear slot of the staple cartridge body, the cutting member having a blade and a flange including an upper surface which interacts with the abutment surface of the staple cartridge body, the flange being spaced distally of the blade, the cutting member being pivotable from a first position intersecting a tissue contacting plane defined by the planar tissue cutting surface, to a second position out of intersection with the tissue contacting plane, the cutting member being pivotable to the second position when the camming surface of the cutting member contacts the abutment surface of the staple cartridge body.

5. A disposable loading unit for a surgical stapling apparatus comprising:

a staple cartridge body defining a longitudinal pathway and a plurality of spaced apart retention slots, each retention slot being dimensioned to receive a surgical fastener;

a plurality of fastener ejection members disposed adjacent the plurality of spaced apart retention slots and communicating with the longitudinal pathway;

an actuator at least partially disposed within the staple cartridge body and configured to be translated through the longitudinal pathway to contact the fastener ejection members and sequentially eject the surgical fasteners from their respective retention slots, the actuator including a base portion defining a plane and having at least two upstanding parallel cam plates each defining an angled leading edge for contacting the fastener ejection members;

a cutting member including a blade and a blade carrier, the cutting member being configured to translate through the staple cartridge body, the blade carrier including a flange configured to engage the base portion of the actuator;

wherein the staple cartridge body includes a planar tissue contacting surface through which extends a linear slot to accommodate translation of the cutting member, the planar tissue contacting surface defining a tissue contacting plane, the cutting member being movable from a first position intersecting the tissue contacting plane to a second position located beneath the tissue contacting plane.

6. A disposable loading unit according toclaim 5, wherein the at least two upstanding parallel cam plates includes four upstanding parallel cam plates.

7. A disposable loading unit according toclaim 6, wherein two of the four upstanding parallel cam plates are positioned on each side of the linear slot.

8. A disposable loading unit according toclaim 5, wherein the blade is located proximally of the angled leading edge of each of the at least two upstanding parallel cam plates.

9. A disposable loading unit for a surgical stapling apparatus comprising:

a staple cartridge body having a planar tissue contacting surface defining a tissue contacting plane, said body defining a longitudinal pathway therethrough and a linear slot traversing said planar tissue contacting surface, said body further defining a plurality of fastener retention slots on both sides of said linear slot, said fastener retention slots slidably supporting a respective surgical fastener and at least a portion of a surgical fastener ejection member;

an actuator having a beam portion and at least two cam plates having distal camming surfaces, said actuator configured to move in at least a distal direction through said longitudinal pathway to sequentially engage said cam plates with a portion of said surgical fastener ejection members to drive said surgical fasteners transversely with respect to said longitudinal pathway;

a cutting member having a blade support and a blade, the blade support of said cutting member being connected to said beam portion of said actuator in a manner that allows said blade to translate with said actuator from adjacent a proximal end of said linear slot to adjacent a distal end of said linear slot to bisect said tissue contacting plane, said blade support including a proximally projecting flange which contacts the actuator, wherein when the actuator moves distally through said longitudinal pathway, the blade support, in cooperation with the beam portion of the actuator, maintains the blase in a cutting position.

10. A disposable loading unit according toclaim 9, wherein said blade support is positioned proximal to said distal camming surfaces of said cam plates.

11. A disposable loading unit according toclaim 9, wherein said longitudinal pathway defined in said staple cartridge body is configured to allow said blade to be lowered substantially out of said tissue contacting plane adjacent a distal portion of said linear slot.

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