Patent Description:
The present disclosure relates to surgical stapling instruments for applying surgical fasteners or staples to body tissue and, more particularly to surgical stapling instruments utilizing bent backspan staples and having a corresponding anvil including bent staple forming buckets.

Surgical stapling devices for applying an annular array of staples or fasteners to tissue are well known in the art. For example, such surgical stapling devices have particular utility in performing small bowl resection with end-to-end anastomosis. These devices, typically, include a staple pusher assembly or member and an anvil assembly or member at the distal end of the surgical stapling device. The anvil member is movable from a retracted configuration for positioning tissue between the anvil member and the cartridge assembly, to an advanced configuration for joining tissue, i.e., stapling the ends of a tubular organ in a body of the patient organ to be joined. One or more annular or circular arrays of fasteners, such as, for example, staples, is operably housed in the cartridge assembly. The anvil member includes one or more corresponding annular arrays of staple forming bucket members that clinch or form (e.g., in a "B" staple formation) the staples after the staples are expelled from the cartridge assembly. Generally, the staples include a straight backspan. As can be appreciated, the anvil bucket members and/or pushers associated with the cartridge assembly include a corresponding configuration, i.e., a generally straight configuration, to accommodate the straight backspan of the staples.

For a given staple pusher configuration configured for use with straight backspan staples, the number of staples that may be present in a given annular array of staples is limited by the length of the backspan of the staples and an inside and outside diameter of the cartridge assembly. Moreover, it is, typically, an inside annular array of the staples that determine the number of staples that may be present in each additional annular array of staples, e.g., middle and outer annular arrays, of the cartridge assembly. That is, an equal number of staples in each of the annular arrays is, typically, provided to allow for consistent overlap at a gap between each consecutive staple; a specific gap distance exists between each consecutive staple for each annular array of staples, with, typically, the smallest gap distance between each consecutive staple existing in the inner annular array and the gap distance between consecutive staples increasing from the inner annular array to the outer annular array(s). As a result thereof, the gap distances between consecutive staples in the inner and subsequent annular array(s) are unequal. These unequal gap distances are not conducive to obtaining a "tight" staple line. That is, an equal gap distance between consecutive staples in each annular array of staples may promote better healing of the stapled tissue, which, in turn, results in less bleeding and leakage at the stapled tissue line. Unfortunately, the length of the backspan of the aforementioned staples is limited by geometry from interfering with, i.e., extending into, the next row of staples. As a result thereof, subsequent to tissue being stapled with conventional surgical stapling devices, there exists a chance of bleeding and leakage occurring at the stapled tissue line, i.e., adjacent the area between consecutive staples in the annular array of staples in the outer annular array(s). Or, in certain instance, a compromised stapled tissue line being formed, which, in turn, may result in the stapled tissue separating.

Document <CIT> discloses an anvil assembly, an end effector and/or a surgical stapler suitable for performing curved or circular anastomosis and/or treatment to internal walls of hollow tissue organs wherein the anvil assembly includes an anvil center rod having a proximal end and a distal end, the center rod defining a central longitudinal axis; and an anvil head secured to the distal end of the anvil center rod. The anvil head includes an anvil plate defining a tissue contact surface; and a plurality of staple forming pockets formed in the tissue contact surface of the anvil plate, wherein each of the plurality of staple pockets defines an arcuate longitudinal axis.

Document <CIT> discloses a surgical stapler with mechanisms for reducing the firing force. This documents discloses a staple that includes a backspan with a lateral displacement, and legs with tips. This feature allows the tips of the staple to avoid contact with the backspan when used with a prior art dimple.

According to the invention and as defined in claim <NUM>, a surgical stapler comprises: a tubular body portion; an anvil member disposed at the end of the tubular body portion with straight buckets arranged as an inner and outer annular array; and a surgical staple cartridge assembly disposed at a distal end of the body portion opposite the anvil member. The cartridge has a first inner and a second outer annular array of staples arranged to be ejected therefrom and the straight buckets of the first inner array have a length which is shorter than the length of the buckets in the outer array. The staples have backspans which are generally bent, angled or curved in a plane different to the plane of the legs such that the legs may be crimped to or beyond the backspan when crimped by the straight buckets of the anvil member and such that the staples of the first inner array have a length of backspan which is smaller than the length of the backspan of the outer array such that gaps between each consecutive staple of the first inner array is equal to the gap between each consecutive staple in the outer array and a gap between each consecutive staple forming bucket in the inner annular array of staple forming buckets is equal to a gap between each consecutive staple forming bucket in the outer annular array of the staple forming buckets.

Specific embodiments of the invention are set forth in the dependent claims.

In an aspect of the present disclosure, a surgical stapler comprises: a tubular body portion; a cartridge assembly disposed at a distal end of the body portion for expelling an annular array of staples, each of the staples of the annular array of staples having legsand a generally bent or curved backspan; and an anvil member disposed at the distal end of the tubular body portion and positioned opposite the cartridge assembly to crimp the staples in tissue upon expulsion of the staples from the cartridge assembly, the anvil member having a corresponding annular array of staple forming buckets, each of the buckets having a straight configuration, the staples being crimped by the buckets so that the legs extend to or beyond the backspan.

In certain examples, the cartridge assembly includes an inner annular array of staples and an outer annular array of staples, and the anvil member includes an inner annular array and an outer annular array of staple forming buckets. A length of each of the staples in the inner annular array of staples can be shorter than a length of the each of the staples in the outer annular array of staples and a length of each of the staple forming buckets in the inner annular array of staple forming buckets can be shorter than a length of the each of the staple forming buckets in the outer annular array of staple forming buckets. A gap between each consecutive staple in the inner annular array of staples can be equal to a gap between each consecutive staple in the outer annular array of staples and a gap between each consecutive staple forming bucket in the inner annular array of staple forming buckets can be equal to a gap between each consecutive staple forming bucket in the outer annular array of staple forming buckets.

A gap between each consecutive staple in the inner annular array of staples can be equal to a gap between each consecutive staple in the outer annular array of staples and a gap between each consecutive staple forming bucket in the inner annular array of staple forming buckets can be equal to a gap between each consecutive staple forming bucket in the outer annular array of staple forming buckets.

In certain examples, a length of each of the staples in the inner and outer annular array of staples are equal to one another and a length of each of the staple forming buckets in the inner and outer annular array of staple forming buckets are equal to one another.

In another aspect of the present disclosure, a surgical stapler comprises: a tubular body portion; a cartridge assembly disposed at a distal end of the body portion for expelling inner and outer annular arrays of staples having legs and a generally bent or curved backspan, wherein a length of the backspan of the staples in the outer annular array of staples is greater than a length of the backspan of the staples in the inner annular array of staples; and an anvil member disposed at the distal end of the tubular body portion and positioned opposite the cartridge assembly to crimp the staples in tissue upon expulsion of the staples from the cartridge assembly, the anvil member having corresponding inner and outer annular arrays of staple forming buckets, each of the staple forming buckets having a straight configuration, the staples being crimped by the buckets so that the legs extend to or beyond the backspan.

In certain examples, a gap between each consecutive staple in the inner annular array of staples is equal to a gap between each consecutive staple in the outer annular array of staples and a gap between each consecutive staple forming bucket in the inner annular array of staple forming buckets is equal to a gap between each consecutive staple forming bucket in the outer annular array of staple forming buckets.

In another aspect of the present disclosure, a surgical stapler comprises: a tubular body portion; a cartridge assembly disposed at a distal end of the body portion for expelling a first annular array of staples, each of the staples of the first annular array of staples having a generally straight backspan; and an anvil member disposed at the distal end of the tubular body portion and positioned opposite the cartridge assembly to crimp the staples in tissue upon expulsion of the staples from the cartridge assembly, the anvil member having a corresponding first annular array of staple forming buckets, each of the buckets having a curved or bent configuration such that the annular arrays of staples are crimped beyond the generally straight backspan during formation thereof to provide a first compressive space.

The surgical stapler may have a second annular array of staples and a corresponding second annular array of staple forming buckets, wherein the second annular array of staple forming buckets includes a depth that is less than a depth of the first annular array of staple forming buckets. The formed staples of the second annular array of staples may be crimped to provide a second compressive space that is different than the first compressive space.

In another aspect, a surgical stapler comprises: a tubular body portion; a cartridge assembly disposed at a distal end of the body portion for expelling a first annular array of staples, each of the staples of the first annular array of staples having a generally angled backspan; and an anvil member disposed at the distal end of the tubular body portion and positioned opposite the cartridge assembly to clinch the staples in tissue upon expulsion of the staples from the cartridge assembly, the anvil member having a corresponding first annular array of staple forming buckets, each of the buckets configured to accommodate the generally straight configuration of the staples to facilitate formation thereof such that the annular arrays of staples are crimped beyond the generally angled backspan during formation thereof to provide a first compressive space.

Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein:.

Detailed embodiments of the present disclosure are disclosed herein; however, the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. 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 present disclosure in virtually any appropriately detailed structure.

In the drawings and in the descriptions that follow, the term "proximal," as is traditional, will refer to the end of a surgical instrument that is closer to the user, while the term "distal" will refer to the end of the surgical instrument that is farther from the user.

Referring now in specific detail to the drawings, in which like reference numerals identify similar or identical elements throughout the several views, <FIG> shows a surgical stapling apparatus <NUM> (apparatus <NUM>) in accordance with an embodiment of the present disclosure. Apparatus <NUM> is configured to perform a circular anastomosis of a tubular organ. Briefly, apparatus <NUM> includes a handle assembly <NUM> having one or more pivotable actuating handle members <NUM> (two pivotable handle members <NUM> shown in the drawings). Apparatus <NUM> includes an advancing device <NUM> including a rotatable grip member <NUM> that is configured to approximate an anvil member <NUM> towards a cartridge assembly <NUM>. Extending from handle assembly <NUM> is a tubular body portion <NUM> that includes a generally curved configuration. In certain embodiments, body portion <NUM> may also be straight and, in other embodiments, may be flexible to bend to any configuration. Body portion <NUM> terminates in cartridge assembly <NUM> that is associated with an annular array of staples <NUM>, see <FIG>, <FIG> and <FIG>. Anvil member <NUM> is positioned opposite cartridge assembly <NUM> and is connected to apparatus <NUM> by shaft <NUM> at connection device or structure (not explicitly shown) operably disposed within the cartridge assembly <NUM>. For a more detailed description of the body portion <NUM>, advancing device <NUM>, handle assembly <NUM> including handle members <NUM> reference is made to commonly-owned <CIT>. For example, the tubular body portion <NUM> can include a shaft for connection to the shaft <NUM> and the rotatable grip member <NUM> when rotated moves the shaft of the body portion <NUM> and approximates the anvil member <NUM> with the staple cartridge assembly <NUM>. The stapling apparatus <NUM> further includes a pusher member, having a plurality of fingers for advancing the staples out of the cartridge assembly <NUM> and toward the anvil member. Movement of the pivoting actuating handle members <NUM> moves the pusher member to eject the staples. The handle assembly <NUM> includes assemblies for moving the shaft of the body portion <NUM> and pusher member. For example, a cam member having a helical groove receives a pin of the grip member <NUM> so that as the grip member is rotated, the cam member moves proximally, moving the shaft of the body portion <NUM>. Threaded members and other means can be used to actuate the pusher member and move the anvil member <NUM> toward and away from the cartridge assembly <NUM>. It is contemplated that the cartridge assembly is a removable and replaceable unit, so that the stapling apparatus <NUM> can be reloaded and used again.

It is also contemplated that the apparatus has a replaceable head including the cartridge assembly, anvil member and associated mechanisms. The stapling apparatus <NUM> can include the manually actuated handle assembly of <FIG> and as described above, or can include a powered actuator assembly having first and second drive members. For example, <CIT>, discloses a surgical device having a powered actuator assembly. Such actuator assembly can be powered by a motorized handle.

With reference to now to <FIG>, <FIG>, anvil member <NUM> and cartridge assembly <NUM> according to an embodiment of the present disclosure is illustrated.

Cartridge assembly <NUM> is configured to house a plurality of staples <NUM> (<FIG>, <FIG> and <FIG>). In particular, cartridge assembly <NUM> includes an array of annular slots <NUM> (<FIG> and <FIG>) that are configured to house a corresponding annular array of staples <NUM> (<FIG> and <FIG>). In the illustrated embodiment, there are three annular arrays of slots <NUM> including an inner annular array of slots 30a, a middle annular array of slots 30b and an outer annular array of slots 30c (collectively referred to herein as slots <NUM> unless otherwise noted) and three corresponding annular arrays of staples including an inner annular array of staples 24a, a middle annular array of staples 24b and an outer annular array of staples 24c (collectively referred to herein as staples <NUM> unless otherwise noted), see <FIG>. In certain embodiments, cartridge assembly <NUM> and anvil member <NUM> may include two annular arrays of staples and corresponding slots.

Slots <NUM> are aligned with a plurality of corresponding staple pushers (not explicitly shown). In certain embodiments, the staple pushers include a generally bent configuration to facilitate expelling the staples <NUM> from the cartridge assembly <NUM>. In other embodiments, the staple pushers may be configured with other configurations, i.e., straight, rounded, etc..

Staples <NUM> may be made from any suitable biocompatible material including, but not limited, to surgical steel, shape memory alloys, polymeric materials, etc. In the illustrated embodiment, the staples <NUM> are made from surgical steel. In certain embodiments, it may prove advantageous to have one or more annular array of staples, e.g., inner annular array of staples 24a, made from one material and one or more annular array of staples, e.g., middle annular array of staples 24b and outer annular array of staples 24c, made from a different material.

Staples <NUM> are similar to conventional staples, however, unlike conventional staples (<FIG>), staples <NUM> include a backspan <NUM> having a generally bent or angled configuration, as best seen in <FIG>. The bent backspan of the staples <NUM> allows the staples to be arranged such that an equal or consistent gap distance "G" between each consecutive staple in the inner annular array of staples 24a, middle annular array of staples 24b, and outer annular array of staples 24c is achievable (<FIG>), as described in greater detail below.

Continuing with reference to <FIG>, the operative features of the staples <NUM> are described in terms of staples 24a of the inner annular array of staples 24a. Staples 24a include a pair of legs 36a having a generally pointed tip (as best seen in <FIG>), although the tip may include other suitable configurations, e.g., blunt, flat, beveled, etc. Legs 36a extend from a backspan 32a.

Backspan 32a includes a generally bent or curved configuration, wherein a radius of curvature of the backspan 32a is greatest at a medial portion 38a (<FIG>). The radius of curvature at the medial portion 38a may be adjusted to accommodate specific surgical procedures, specific surgical devices, a number of annular arrays of staples, a manufacturer's contemplated uses, etc. The bent backspan 32a of the staples 24a allows the staples 24a to be arranged in the inner annular array staples 24a with a minimum gap distance "G" between each consecutive staple 24a. That is, unlike conventional staples with straight backspans, the bent backspan 32a of the staple 24a is configured to follow a contour of the cartridge assembly <NUM> and, thus, allow a "tighter" grouping of the staples 24a (i.e., a higher density of staples) in the inner annular array of staples 24a. Moreover, a bent backspan 32b and 32c of the staples 24b and 24c, respectively, allows the lengths of the staples in these annular arrays to be larger than the lengths of the staples 24a in the annular array of staples 24a. That is, because of the bent backspans 32b and 32c of respective staples 24b and 24c, a length of the staples 24b and 24c can be increased to accommodate "overlapping" of specific gap distances "G" between consecutive staples 24a in the annular array of staples 24a. For example, and with specific reference to <FIG>, each staple 24a in the inner annular array of staples 24a includes a length "A" and a gap between each consecutive staple 24a in the inner annular array of staples 24a is equal to gap "G. " The length of staples 24b in the middle annular array of staples 24b includes a length "B" that is larger than the length "A" of the staples 24a, and a gap between each consecutive staple 24b in the middle annular array of staples 24b is equal to the gap "G" (see <FIG>). The length of staples 24c in the outer annular array of staples 24c includes a length "C" that is larger than the lengths "A" and "B" of the respective staples 24a and 24c, and a gap between each consecutive staple 24c in the outer annular array of staples 24c is equal to the gap "G" (see <FIG>).

As can appreciated, the "tighter" grouping of the staples 24a-24c allows the staples to "nested" and, thus, more closely packed together with respect to one another for a given cartridge assembly <NUM> when compared to staples with straight backspans. This "nested" configuration of the staples 24a-24c provides an increased inside diameter of staples 24a when compared to staples with straight backspans.

With reference now to <FIG> and <FIG>, anvil member <NUM> includes corresponding annular arrays of staple forming buckets <NUM> including an inner annular array of staple forming buckets 40a, a middle annular array of buckets 40b and an outer annular array of buckets 40c. Unlike conventional staple forming buckets (<FIG> and <FIG>), each of the staple forming buckets 40a, 40b and 40c are configured to accommodate the generally bent configuration of the corresponding staples 24a, 24b and 24c to facilitate formation thereof. To this end, each of the buckets 40a, 40b and 40c include a generally bent or curved configuration and is proportioned to respective staples 24a, 24b and 24c therein such that the staples 24a, 24b and 24c have a generally "B" configuration upon formation thereof. A radius of curvature of the staple forming buckets 40a, 40b and 40c is greatest at a medial portion 38a to match the radius of curvature of the corresponding staples 24a, 24b and 24c.

Continuing with reference to <FIG> and <FIG>, the dimensions of the staple forming bucket 40a in the inner annular array of staple forming buckets 40a is substantially equal to the dimensions of the corresponding staples 24a. In particular, the staple forming bucket 40a is slightly larger than the staple 24a to facilitate forming the staple 24a into the "B" formation. A gap between each consecutive staple forming bucket 40a in the inner annular array of staple forming bucket 40a is equal to gap "G<NUM>. " In the illustrated embodiment, the gap "G<NUM>" is illustrated less than the gap "G" as a result of the staple forming bucket 40a being larger than the staple 24a. Alternatively, and in certain embodiments, the gap "G<NUM>" may be equal to the gap "G. " Similarly, the dimensions of the staple forming buckets 40b and 40c of the middle and outer annular arrays of staple forming buckets 40b and 40c are substantially equal to the dimensions of the corresponding staples 24b and 24c of the middle and outer annular arrays of staples 24b and 24c. The gap between each consecutive staple forming buckets 40b and 40c is equal to the gap "G<NUM>" between each consecutive staple forming bucket 40a, see <FIG>.

In use, tissue, e.g., a portion of a tubular organ, is positioned between the anvil member <NUM> and cartridge assembly <NUM>. Rotatable grip <NUM> of the advancing device <NUM> is actuated to approximate the anvil member <NUM> towards the cartridge assembly <NUM>. Handles <NUM> may be pivoted to drive or expel the staples <NUM> through the tissue against the anvil member <NUM> to complete a circular anastomosis of a tubular organ.

In accordance with the present disclosure, the annular arrays of formed staples 24a, 24b and 24c form a "tight" staple line by virtue of the consistent gap "G" between consecutive staples 24a, 24b and 24c in the inner, middle and outer annular arrays of staples 24a, 24b and 24c, and the likelihood of bleeding or leaking occurring between consecutive staples 24a, 24b and 24c in the inner, middle and outer annular arrays of staples 24a, 24b and 24c is reduced, if not eliminated. The unique bent configuration of the staples 24a, 24b and 24c and corresponding staple forming buckets 40a, 40b and 40c overcomes the aforementioned drawbacks typically associated with conventional surgical stapling devices. That is, gaps "g1," "g2," and "g3" (<FIG> and <FIG>) between consecutive staple forming buckets in respective inner, middle and outer annular arrays of conventional surgical stapling devices, increase from the inner annular array toward the outer annular array, i.e., "g1"<"g2"<"g3;" as can be appreciated, the formed staples in tissue will be spaced apart from one another at a distance that corresponds to the gap distances "g1," "g2," and "g3, of the staple forming buckets. As noted above, these "unequal" gap distances are not conducive in obtaining a "tight" staple line.

From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, while the staples 24a, 24b and 24c and corresponding staple forming buckets 40a, 40b and 40c have been described herein as having different lengths, it is within the purview of the present disclosure that the staples 24a, 24b and 24c and corresponding staple forming buckets 40a, 40b and 40c may have the same lengths (<FIG> and <FIG>). In this embodiment, the staples (not explicitly shown) and corresponding staple forming buckets <NUM> including inner, middle and outer annular arrays of staple forming buckets 140a-140c have the same length. In the embodiment illustrated in <FIG> and <FIG>, an equal number of staple forming buckets <NUM> are shown in the inner annular array of staple forming buckets 140a, middle annular array of staple forming buckets 140b and outer annular array of staple forming buckets 140c. This embodiment may prove advantageous where a "tight" staple line is not required.

In the instance where a "tight" staple line is required, however, the unique bent backspan of the staples and corresponding staple forming buckets 140b-140c allows for one or more extra staples (or larger staples) and corresponding staple forming buckets 140b-140c to be provided in the middle and outer annular arrays of staples and corresponding staple forming buckets 140b-140c. That is, for a given cartridge assembly and anvil, the geometry, e.g., bent backspan, of the staples and corresponding staple forming buckets 140b-140c follows a contour of the cartridge assembly and anvil, respectively, and, as a result thereof, allows extra staples and staple forming buckets 140b to be provided in the annular array of staple forming buckets 140b without interfering with staples and staple forming buckets 140c. And, likewise, allows extra staples and staple forming buckets 140c to be provided in the annular array of staple forming buckets 140c without interfering or extending into an outer peripheral edge of the cartridge assembly and anvil. The extra staples and corresponding staple forming buckets 140a-140c may be provided to sufficiently overlap the gaps between consecutive staples and staple forming buckets 140a-140c.

With reference to <FIG> an alternate embodiment of the staple and staple forming buckets are illustrated designated <NUM> (<FIG>) and <NUM> (<FIG> and <FIG>), respectively. Only those features unique to staples <NUM> and staple forming buckets <NUM> are discussed herein.

In the embodiment illustrated in <FIG>, staples <NUM> and staple forming buckets <NUM> may be utilized to provide formed staples with different internal spaces for compressing tissue to achieve a desired level of hemostasis and blood flow in stapled tissue segments. In one particular embodiment, for example, an inner annular row of staples 224a (staples 224a) may provide a greater compressive space (<FIG> and <FIG>) for stapling tissue than an outer annular row of staples 224b (staples 224b), see <FIG>. In other words, staples 224b in a formed configuration provide a greater compressive force to stapled tissue than the staples 224a in a formed configuration. Thus, because a pressure exerted on tissue stapled by staples 224b is greater than the pressure exerted on tissue stapled by staples 224a, the blood flow through the tissue surrounding staples 224b will be less (more restricted) than the blood flow through the tissue surrounding staples 224a, thereby further facilitating hemostasis. However, because blood flow is not completely restricted through tissue stapled by staples 224b, blood perfusion is improved and unnecessary necrosis of the stapled tissue may be prevented and/or impeded.

Staples 224a and 224b include respective staple legs 236a (<FIG>) and 236b (<FIG>) that extend from backspans 232a, 232b. In the embodiment illustrated in <FIG>, staple legs 236a and 236b have the same length as each other, and backspans 232a, 232b include a "straight" configuration to facilitate forming staples 224a, 224b in the staple forming buckets 240a, 240b (<FIG> and <FIG>).

Staple forming buckets <NUM> are described herein in terms of inner annular row of staple forming buckets 240a (buckets 240a) and outer annular row of staple forming buckets 240b (buckets 240a), see <FIG> and <FIG>. As can be appreciated, greater or fewer rows of buckets <NUM> may be utilized.

Each of buckets 240a and 240b are configured to receive corresponding staples 224a and 224b therein to form the staples 224a and 224b. Buckets 240a and 240b include an angled configuration to facilitate forming the respective staples 224a and 224b. Unlike the previously described staple forming buckets, however, buckets 240a include depth that is different from a depth of buckets 240b to facilitate forming the staples 224a and 224b with different compressive spaces. For example, and in one particular embodiment, buckets 240a include a depth that is greater than a depth of the buckets 240b to form the staples 224a with a compressive space "CS1" (<FIG>) that is greater than a compressive space "CS2" (<FIG>) of the staples 224b. Specifically, the angled buckets 240a, 240b having different depths in combination with the staples 224a, 224b having respective straight backspans 232a, 232b and legs 236a and 236b with the same length allows the staples 224a, 224b to formed with different compressive spaces, see <FIG> for example. That is, this specific combination of staples 224a, 224b and buckets 240a, 240b allows staples 224b to be crimped beyond the backspan 232b (<FIG>) to provide a compressive space "CS2" that is less than a compressive space "CS1" provided by the staples 224a such that tissue stapled by staples 224b is under greater pressure than tissue stapled by staples 224a. In this way, the backspan does not interfere with the deformation of the legs of the staples, and the degree of crimping can be varied. The staples can be crimped by the buckets so that the legs of the staples extend to or beyond the backspan without interference from the backspan.

In certain embodiments, it may prove advantageous to have the staples 224a exert a greater pressure to stapled tissue than the staples 224b. In this embodiment, buckets 240a will include a depth that is less than a depth of the buckets 240b.

In certain embodiments, each of the staples 224a, 224b may be crimped beyond the respective backspans 232a, 232b. For example, the buckets 240a may have a depth that is configured to crimp the staples 224a beyond the backspan 232a such that the compressive space provided therefrom is greater than or less than the compressive space provided by staples 224b.

In one particular embodiment, the buckets 240a, 240b may have the same depth and the staple legs 236a, 236b may have different lengths to achieve the aforementioned compressive spaces. Those skilled in the art will appreciate the various lengths of the staple legs 236a, 236b that will be needed to achieve a specific compressive space when the staples 224a and 224b are formed.

In certain embodiments, the operation of the advancing device <NUM>, the pusher member, or both, can be utilized to vary the degree to which the staples are deformed or crimped. For example, by approximating the anvil member more closely with the cartridge assembly, the staples are crimped with a relatively smaller internal space and the tissue is compressed to a greater degree. Alternatively, the pusher member can be further advanced, further crimping or deforming the staples. Desirably, there is an indicator on the stapling apparatus handle assembly <NUM> that allows the surgeon to gauge the degree to which the staples will be crimped. The varyable crimp can be used in any of the embodiments disclosed herein, including embodiments in which different sized (preformation) staples are used, same sized staples are used, bent or curved backspan staples are used, and/or bent or curved staple forming buckets are used.

In some embodiments, such as the one illustrated in <FIG>, the buckets (not explicitly shown) may have a generally straight configuration and the staples <NUM> may include a backspan <NUM> having a generally angled configuration to facilitate crimping the staples <NUM> beyond the backspan <NUM>. In this way, the backspan does not interfere with the deformation or crimping of the legs of the staples. The staples can be crimped by the buckets so that the legs extend to or beyond the backspan, without interference from the backspan. In one particular embodiment, for example, a formed staple 324a with legs 336a extending from an angled backspan 332a may provide a compressive space that is similar to compressive space "CS1" (<FIG>) and formed staple 324b with legs 336b extending from an angled backspan 332b may provide a compressive space that is similar to compressive space "CS2" (<FIG>). The straight configuration of the buckets can be used with any of the embodiments disclosed herein, including stapling apparatus that vary the degree of crimping or deformation of the staples, as well as embodiments in which different sized (preformation) staples are used, or same sized staples are used.

It is also contemplated that the stapling apparatus can be configured to apply three rows of staples, and that the staples can have more than one bend in the backspan, or a curved backspan that is irregular (i.e., having more than one radius), in any of the embodiments disclosed herein.

Claim 1:
A surgical stapler, comprising:
a tubular body portion;
an anvil member disposed at the end of the tubular body portion with straight buckets arranged as an inner and outer annular array; and
a surgical staple cartridge assembly disposed at a distal end of the body portion opposite the anvil member which cartridge having a first inner and a second outer annular array of staples arranged to be ejected therefrom
wherein the straight buckets of the first inner array have a length which is shorter than the length of the buckets in the outer array and
wherein the staples have backspans which are generally bent, angled or curved in a plane different to the plane of the legs such that the legs may be crimped to or beyond the backspan when crimped by the straight buckets of the anvil member and such that the staples of the first inner array have a length of backspan which is smaller than the length of the backspan of the outer array such that gaps between each consecutive staple of the first inner array is equal to the gap between each consecutive staple in the outer array and a gap between each consecutive staple forming bucket in the inner annular array of staple forming buckets is equal to a gap between each consecutive staple forming bucket in the outer annular array of the staple forming buckets.