Patent Description:
A typical surgical stapler apparatus comprises a handle at a proximal end and two elongated jaw-like members joined together at a hinge at a distal end. The jaw-like members articulate to open and close to capture tissue between the jaw-like members. The user controls the device from the handle to open and close the jaw-like members, actuate deployment of staples and in general manipulate and control the device. One of the jaw members carries a disposable cartridge containing staples arranged in two or more rows. The other one of the jaw-like members comprises an anvil against which the staples are driven to deform the staple legs. Staples are driven out of the cartridge by a caming surface or slider that moves longitudinally against a plurality of laterally positioned pushers that push each staple out of the cartridge individually. The caming surface of the slider is angled to compliment the angular surface of the pushers. The cooperation between the angular surfaces of the pushers and the slider is a key step of the surgical stapling process. Misalignment can cause the staples to jam the device. Some staplers include a blade that follows the caming surface so as to cut the tissue between the two or more rows of delivered staples.

Surgical staplers are used in a variety of surgical techniques including laparoscopic and/or endoscopic or other minimally invasive surgical procedures in which the stapler is inserted through a cannula or tube positioned within a small incision in a patient's body. In laparoscopic, endoscopic or minimally invasive surgery, a trocar or cannula is inserted across body tissue of a patient to access a body cavity and to create a channel for the insertion of a camera, such as a laparoscope. The camera provides a live video feed capturing images that are then displayed to the surgeon on one or more monitors. Additional trocars are inserted to create additional pathways through which surgical instruments, including surgical staplers, can be inserted for performing procedures observed on the monitor. The targeted tissue location such as the abdomen is typically enlarged by delivering carbon dioxide gas to insufflate the body cavity and create a working space large enough to accommodate the scope and instruments used by the surgeon. The insufflation pressure in the tissue cavity is maintained by using specialized trocars having seals that prevent the insufflation gas from escaping and collapsing the surgical working space. Laparoscopic surgery offers a number of advantages when compared with an open procedure. These advantages include reduced pain and hemorrhaging and shorter recovery times.

As laparoscopic surgery evolves to become even more minimally invasive with incisions and cannula diameters becoming smaller and smaller, surgical staplers for use in laparoscopic/endoscopic procedures must be designed to fit within the small lumen of a cannula. Generally, a surgical stapler is inserted into a cannula such that the jaw-like members are in a closed orientation to inside the patient where the jaw-like members are opened to grasp and staple tissue. The handle of the stapler resides outside of the patient in control of the surgeon user. A portion of the shaft of the stapler between the jaw-like members and the handle is long enough to extend from outside the patient to inside the patient. During the surgical procedure, the elongate shaft of the stapler resides inside the cannula into which it was inserted. The distal jaw-like members include many components such as an anvil for forming staples, a staple cartridge with a plurality of staples, a caming surface such as a slider, pushers, a blade and other components which must all be small enough to fit through a small diameter cannula and made to function reliably and repeatedly from outside the patient. While conventional laparoscopic staplers are approximately <NUM> millimeters in diameter, the present invention provides a surgical stapler designed to fit inside a cannula having a diameter as small as approximately <NUM>-<NUM>.

Documents <CIT>, <CIT> and <CIT> disclose examples of known surgical staplers.

Referring to <FIG>, there is shown a perspective view of a surgical stapler <NUM> according to the present invention. The stapler <NUM> is comprised of a handle assembly <NUM> removably connected to a stapler cartridge assembly <NUM>. The handle assembly <NUM> is configured to control the instrument and actuate deployment of staples located in the distal end of the stapler cartridge assembly <NUM>. After the staples have been expended from the stapler <NUM>, the stapler cartridge assembly <NUM> is removed from the handle assembly <NUM> and a new stapler cartridge assembly <NUM> is connected to the handle assembly <NUM> for continued stapling.

Turning to <FIG>, the stapler cartridge assembly <NUM> will now be discussed in detail. The stapler cartridge assembly <NUM> includes a connector <NUM> at the proximal end and an end effector <NUM> at the distal end. An outer tube <NUM> is connected to the end effector <NUM> at the distal end and to the connector <NUM> at the proximal end. An actuator shaft <NUM> is disposed inside the lumen of the outer tube <NUM>. The outer tube <NUM> is substantially cylindrical having an outer diameter of approximately <NUM>-<NUM>. The actuator shaft <NUM> is configured to slide longitudinally relative to the outer tube <NUM>. Detail of the proximal end of the stapler cartridge assembly <NUM> is shown in <FIG>.

Turning to <FIG>, the proximal end of the stapler cartridge assembly <NUM> is shown. The connector <NUM> includes a bolt <NUM> that extends laterally outwardly from the outer surface of the connector <NUM>. A similar bolt <NUM> extends on the opposite side of the connector <NUM> and is not visible in <FIG>. The bolt <NUM> is configured for a bayonet-like connection with the handle assembly <NUM> of the stapler <NUM> that includes a complementary slot for receiving the bolt <NUM> to secure the cartridge assembly <NUM> to the handle assembly <NUM>. <FIG> also illustrates the actuator shaft <NUM> moved proximally relative to the outer tube <NUM> when compared to <FIG> in which the actuator shaft <NUM> is shown to be moved more distally relative to the outer tube <NUM>. As seen in <FIG>, the proximal end of the actuator shaft <NUM> includes a bolt <NUM> that extends laterally outwardly from the actuator shaft <NUM>. The bolt <NUM> is configured for a bayonet-like connection with an actuator shaft of the handle assembly <NUM> which includes a complementary slot for receiving the bolt <NUM>. Mating the bolt <NUM> of the connector <NUM> to handle assembly <NUM> simultaneously mates the bolt <NUM> of the actuator shaft <NUM> to the actuator shaft of the handle assembly <NUM>. When connected to the handle assembly <NUM>, the handle assembly <NUM> is used to move the actuator shaft <NUM> forward and backward inside the outer tube <NUM> to effect opening and closing of the distal jaw-like members and the deployment of staples.

Turning to <FIG>, the actuator shaft <NUM> will now be described. The actuator shaft <NUM> is an elongated shaft having a substantially cylindrical proximal portion <NUM> having actuator bolts <NUM> at the proximal end for connection with the actuator of the handle assembly <NUM>. The substantially cylindrical portion <NUM> is sized to fit closely inside lumen of the outer tube <NUM>. The cylindrical portion <NUM> is connected with pins to an extended I-beam portion <NUM> toward the distal end of the actuator shaft <NUM>. The distal end of the actuator shaft <NUM> includes an I-beam <NUM> connected to the extended I-beam portion <NUM>. The I-beam <NUM> is connected to the extended I-beam portion <NUM> as shown in <FIG>.

Turning now to <FIG>, the I-beam <NUM> will now be described. The I-beam <NUM> includes a top portion <NUM> and a bottom portion <NUM> interconnected by a middle portion <NUM>. The top portion <NUM> includes a beveled front end <NUM> and a curved top. The middle portion <NUM> includes a blade <NUM> and an angled portion <NUM> at the front end. At the back end, the middle portion <NUM> includes an extension <NUM> for connecting with the extended I-beam portion <NUM> as shown in <FIG>. The bottom portion <NUM> leads the front end of the I-beam <NUM> and includes a curved bottom. The front-elevational view of the l-beam is shown in <FIG> which illustrates the profile to be in the shape of a capital letter "I".

Turning now to <FIG>, the end effector <NUM> will be described. The end effector <NUM> includes an upper jaw <NUM> hinged to a lower jaw <NUM>. At least one staple cartridge <NUM> containing a plurality of staples <NUM> is disposed inside the lower jaw <NUM>. The at least one staple cartridge <NUM> is configured to received a plurality of staples <NUM> that are not visible in <FIG>. The end effector <NUM> further includes a slider <NUM> configured to urge the staples <NUM> out of the cartridge <NUM>. The slider <NUM> is not visible in <FIG>.

Turning to <FIG>, the upper jaw <NUM> will now be described. The upper jaw <NUM> includes a flat anvil surface <NUM> or plate defining a central slot <NUM>. The central slot <NUM> is elongated with an open proximal end. The central slot <NUM> is sized and configured to receive at least a portion of the middle portion <NUM> of the I-beam <NUM> such that the I-beam <NUM> slides relative to the upper jaw <NUM> inside and along the central slot <NUM>. The outer surface of the upper jaw <NUM> is curved and substantially semicircular in shape to conform to a cylindrical lumen of a cannula in which it is inserted. The upper jaw <NUM> includes a top cover <NUM>. The top cover <NUM> forms part of the outer circumference of the upper jaw <NUM> and together with the anvil surface <NUM> define therebetween a passageway <NUM> for receiving the top portion <NUM> of the I-beam <NUM> such that the top portion <NUM> slides relative to the upper jaw <NUM> inside the passageway <NUM>. At the proximal end, the upper jaw <NUM> further includes flanges having apertures for receiving pins and connecting to the lower jaw <NUM>.

A typical anvil of a conventional surgical stapler includes staple-forming pockets in the surface of the anvil that are designed to receive the legs of a staple and guide, angulate and bend the staple legs as the staple is urged against the anvil. These surface formations of a typical anvil aid in the deformation of the staple as it is deployed to achieve proper staple formation. Any misalignment between the staple-forming pockets and the staple leads to the staples missing the staple forming pockets, resulting in catastrophic failure of the staple line. The detailed staple-forming pockets introduce significant manufacturing difficulties and increase costs of production. Advantageously, the present invention does not utilize staple-forming pockets in the surface of the anvil. The anvil surface is smooth and/or flat. By redesigning the staple to not require anvil pockets to be formed, anvil pockets are eliminated completely simplifying the design while advantageously bringing an additional level of reliability to the stapler <NUM>. Slight misalignment is no longer a concern especially with flat plate designs. The simplified design is also a major benefit for manufacturing as the anvil costs are reduced and the need for ultra-high precision parts to maintain perfect alignment are no longer needed. In one variation, the anvil surface <NUM> is completely flat as shown in <FIG>. In another variation shown in <FIG>, the anvil surface includes a series of curved channels <NUM> having substantially smooth surfaces against which staples can deform into the proper configuration. The lengths of the channels <NUM> are perpendicular to the longitudinal axis of the upper jaw <NUM>. The wave-like arrangement of channels <NUM> defines a central slot <NUM> in the anvil surface and reduces the need for critical alignment from side to side. Critical alignment of the staple is not required as the channels <NUM> are wide enough to easily receive the staple legs. The curvature of the channels <NUM> assists in deflecting the staple legs in the proper direction. In another variation, the anvil surface includes two or more longitudinal curved channels <NUM> that extend along the axis of the device as shown in <FIG>. The elongate curved channels <NUM>, <NUM> permit the formation of staples <NUM> without the worry and cost of proper alignment of each staple with each staple-forming pocket. Although the channels <NUM>, <NUM> are shown to be curved, they can have square or rectangular cross-sections for assisting in closing the staple in the desired direction.

Referring now to <FIG>, the lower jaw <NUM> will be described. The lower jaw <NUM> is an elongate piece sized and configured to complementarily mate with the upper jaw <NUM>. The lower jaw <NUM> has an open top and a curved outer surface. The cross-section of the lower jaw <NUM> is substantially semi-circular in shape except at the proximal end where it is substantially circular in cross-section. The depending flanges of the upper jaw <NUM> attach to the lower jaw <NUM> via pins inserted into apertures in the lower jaw <NUM> near the proximal end. When attached together, the upper jaw <NUM> and lower jaw <NUM> create a substantially cylindrical profile. The distal end of the lower jaw <NUM> is angled and the cylindrical proximal end defines a vertically oriented slot <NUM> visible in <FIG>. This slot <NUM> is sized and configured to receive the extended I-beam portion <NUM> of the actuator shaft <NUM> with the I-beam itself <NUM> residing inside the lower jaw <NUM> distal of the slot <NUM>. The cylindrical proximal end is adapted for attachment to the outer tube <NUM>. The lower jaw <NUM> further includes a staple cartridge receiving portion <NUM>. When one or more staple cartridges <NUM> are inserted into the staple cartridge receiving portion <NUM> of the lower jaw <NUM>, a passageway is defined between the one or more staple cartridges <NUM> and a bottom cover <NUM>. This passageway is sized and configured to receive the bottom portion <NUM> of the I-beam <NUM> such that the bottom portion <NUM> slides longitudinally with respect to lower jaw <NUM> inside the passageway. Inside the staple cartridge receiving portion <NUM>, there is a ledge <NUM> at the distal end for securing the front end of one or more staple cartridges <NUM>. A tongue <NUM> is formed at the proximal end for mating with a groove of the staple cartridge <NUM> to secure the proximal end of the staple cartridge <NUM> to the lower jaw <NUM>. A cartridge retainer <NUM>, shown in <FIG>, covers the distal end tongues of staple cartridges <NUM> after being inserted into the lower jaw <NUM>.

Referring now to <FIG>, the staple cartridge <NUM> will be described. The staple cartridge <NUM> comprises first plate <NUM>, a second plate <NUM> and a third plate <NUM> connected together. The plates <NUM>, <NUM>, <NUM> are made from any polymer material, metal such as aluminum or stainless steel or glass filled nylon. The first plate <NUM> is elongate and substantially rectangular in shape and includes an outer surface <NUM> and an inner surface <NUM>. The outer surface <NUM> is smooth and the inner surface <NUM> is formed with a plurality of staple holding locations <NUM>. The staple holding locations <NUM> are recesses formed in the inner surface <NUM> of the first plate <NUM>. Each staple holding location <NUM> is substantially U-shaped and defined by a front sidewall <NUM> formed oppositely and substantially parallel to a rear sidewall <NUM>. The rear sidewall <NUM> is interconnected to a bottom wall <NUM> forming an L-shaped continuous wall defining a gap <NUM> between the bottom wall <NUM> and the front sidewall <NUM>. In one variation, no gap <NUM> is formed. Instead, the bottom wall <NUM> interconnects with both the front sidewall <NUM> and rear sidewall <NUM> to form a complete U-shaped staple holding location <NUM>. The U-shaped staple holding locations are angled approximately <NUM>-<NUM> degrees with <NUM> degrees being a vertical non-angled orientation. The recessed wall <NUM> is recessed with respect to the inner surface <NUM>. The first plate is approximately <NUM>-<NUM> (<NUM>-<NUM> inches) thick and the depth of each recess or thickness of each sidewall <NUM>, <NUM>, <NUM> is approximately <NUM>-<NUM> (<NUM>-<NUM> inches). The staple holding locations <NUM> are configured for partially receiving and holding a complementary, substantially U-shaped staple that is thicker than the thickness of the sidewalls <NUM>, <NUM>, <NUM>. The distal end of the first plate <NUM> includes a tongue <NUM> and the proximal end of the first plate <NUM> includes a groove <NUM> for connecting with the ledge <NUM> and tongue <NUM> of the lower jaw <NUM>. The distal end and proximal end of the first plate <NUM> further include spacers <NUM>, <NUM>, respectively, that extend inwardly and are configured to space the inner surface <NUM> from the second plate <NUM>. The first plate <NUM> is made of metal or plastic.

The second plate <NUM> or middle shim <NUM> is a thin elongate substantially rectangular shaped plate of metal or plastic having smooth outer surfaces. The second plate <NUM> is approximately <NUM>-<NUM> (<NUM>-<NUM> inches) thick. The distal end includes a tongue <NUM> and the proximal end includes a groove <NUM> that are configured for connecting with the ledge <NUM> and tongue <NUM> of the lower jaw <NUM>. In another variation, two second plates 84a, 84b are provided and each is approximately <NUM> (<NUM> inches) in thickness. The first second plate 84a is sprung such that the first second plate exerts a force towards the first plate <NUM> and the other second plate 84b is also sprung such that it exerts a force towards the third plate <NUM>.

The third plate <NUM> is substantially identical to and a mirror image of the first plate <NUM>. The third plate <NUM> is elongate and substantially rectangular in shape and includes an outer surface <NUM> and an inner surface <NUM>. The outer surface <NUM> is smooth and the inner surface <NUM> is formed with a plurality of staple holding locations <NUM> substantially identical to and a mirror image of the staple holding locations <NUM> of the first plate <NUM>. The staple holding locations <NUM> are recesses formed in the inner surface <NUM> of the third plate <NUM>. Each staple holding location <NUM> is substantially U-shaped and defined by two oppositely formed substantially parallel sidewalls, a front sidewall <NUM> and a rear sidewall <NUM>. The rear sidewall <NUM> is interconnected to a bottom wall <NUM> forming an L-shape continuous wall defining a gap <NUM> between the bottom wall <NUM> and the front sidewall. In one variation, no gap <NUM> is formed. Instead, the bottom wall <NUM> interconnects with both the front sidewall <NUM> and rear sidewall <NUM> to form a complete U-shaped staple holding location <NUM>. The recessed wall <NUM> is recessed with respect to the inner surface <NUM>. The U-shaped staple holding locations are angled approximately <NUM>-<NUM> degrees with <NUM> degrees being a vertical non-angled orientation. The third plate is approximately <NUM>-<NUM> (<NUM>-<NUM> inches) thick and the depth of each recess or thickness of each sidewall <NUM>, <NUM>, <NUM> is approximately <NUM>-<NUM> (<NUM>-<NUM> inches). The staple holding locations <NUM> are configured for partially receiving and holding a complementary, substantially U-shaped staple that is thicker than the thickness of the sidewalls <NUM>, <NUM>, <NUM>. The distal end of the third plate <NUM> includes a tongue <NUM> and the proximal end of the third plate <NUM> includes a groove <NUM> for connecting with the ledge <NUM> and tongue <NUM> of the lower jaw <NUM>. The distal end and proximal end of the third plate <NUM> further include spacers <NUM>, <NUM>, respectively, that extend inwardly and are configured to space the inner surface <NUM> of the third plate <NUM> from the second plate <NUM>.

The first plate <NUM>, second plate <NUM> and third plate <NUM> are connected or sandwiched together to form a staple cartridge <NUM> having two rows of staggered staple pockets <NUM> for placement on one side of the blade <NUM> of the I-beam <NUM>. The staple pockets <NUM> are staggered to form a more complete closed line of staples. A second staple cartridge <NUM> is placed on the other side of the blade <NUM> of the I-beam <NUM> forming two rows of staple pockets <NUM> on the other side of the blade <NUM> for a total of four rows of staple pockets <NUM>. The cartridges <NUM> can be modified with additional plates to create more than two rows of staples and can include three or four rows of staples on each side of the I-beam <NUM>. The staple pockets <NUM> are defined by the recessed wall <NUM>, the front sidewall <NUM>, rear sidewall <NUM>, bottom wall <NUM> and the outer surface of the second plate <NUM>. Each pocket <NUM> includes an open top and a partially open bottom. In one variation, the bottom is closed. Because the spacers <NUM>, <NUM> of the first plate <NUM> space the inner surface <NUM> of the first plate <NUM> from the second plate <NUM>, a first slot <NUM> is formed between the first plate <NUM> and the second plate <NUM>. The first slot <NUM> is configured for receiving a first angled caming surface of the slider <NUM> that will be described in greater detail herein below. The first slot <NUM> intersects with the first row of staple pockets <NUM>. Because the spacers <NUM>, <NUM> of the third plate <NUM> space the inner surface <NUM> of the third plate <NUM> from the second plate <NUM>, a second slot <NUM> is formed between the third plate <NUM> and the second plate <NUM>. The second slot <NUM> is configured for receiving a second angled caming surface of the slider <NUM> that will be described in greater detail herein below. The second slot <NUM> intersects with the second row of staple pockets <NUM>. The same configuration appears on the staple cartridge disposed on the other side of the I-beam <NUM>. The staple cartridge <NUM> is considered to be a single unit holding all the staples on either side of the I-beam <NUM> or alternatively, there are two staple cartridge units, one disposed on either side of the l-beam <NUM>.

Turning now to <FIG>, there is shown another variation of the staple cartridge <NUM> wherein the second plate <NUM> is not smooth but also includes a plurality of staple holding locations <NUM> similar to the staple holding locations <NUM> of the first and third plates <NUM>, <NUM>. In this variation, both opposite outer surfaces of the second plate <NUM> include recesses defined by a recessed wall <NUM> that is recessed from the outer surface, a front sidewall <NUM>, a rear sidewall <NUM> and a bottom wall (not shown). The bottom wall may or may not include a gap. The staple holding locations <NUM> in a first outer surface of the second plate <NUM> are located opposite to the staple holding locations <NUM> of the first plate <NUM> which together define the staple pocket <NUM>. Also, the staple holding locations <NUM> formed in a second outer surface of the second plate <NUM> are located opposite to the staple holding locations <NUM> of the third plate <NUM> which together define the staple pockets <NUM>. The staple holding locations <NUM> have the same angle as their opposite staple holding locations <NUM> in the first and third plates <NUM>, <NUM>. Each pocket <NUM> defined by staple holding locations <NUM> and <NUM> are configured to receive substantially U-shaped staples <NUM> such that they are supported by the sidewalls yet include an unsupported portion of the staple <NUM> that resides in the first and second slots <NUM>, <NUM>. This unsupported portion of the staple <NUM> that resides in either the first or second slots <NUM>, <NUM> is exposed for contact with the angled caming surface of the slider <NUM> as it passes through the slot and urges the staple <NUM> upwardly out of the pocket <NUM>. In this variation in which the second plate <NUM> includes staple holding locations <NUM>, the depth of the staple receiving portions <NUM>, <NUM> are approximately <NUM> (<NUM> inches) each and the width of each slot <NUM>, <NUM> is approximately <NUM>-<NUM> (<NUM>-<NUM> inches) with the total thickness of the staple <NUM> being approximately <NUM> (<NUM> inches) with approximately <NUM> (<NUM> inches) of the staple residing in the slot <NUM>, <NUM>, approximately <NUM> (<NUM> inches) of the staple residing in and supported by the staple holding location <NUM> of the first plate <NUM> and approximately <NUM> (<NUM> inches) of the staple residing in and supported by the staple holding location <NUM> of the third plate <NUM>. <FIG> illustrates the standard arrangement in which two rows of staggered staple pockets <NUM> are located on either side of the slider I-beam <NUM> blade <NUM> for delivering a total of four lines of staggered staples <NUM>. In another variation, the staple cartridge <NUM> is configured to include an additional fourth plate (not shown) sandwiched together for creating a third row of staples pockets <NUM> on either side of the blade <NUM> for a total of six rows of staggered staples <NUM>. Any number of staple rows is within the scope of the present invention achieved by the adding additional plates.

Turning now to <FIG>, in one variation of the invention, an asymmetrical staple cartridge is provided. The asymmetrical staple cartridge utilizes a different number of rows of staple pockets on either side of the I-beam <NUM> blade <NUM>. In one variation, the staple cartridge includes two or three rows of staple pockets on one side of the I-beam <NUM> blade <NUM> and only one row of staple pockets on the other side of the I-beam <NUM> blade <NUM> creating a total of three or four rows of staples with one row of staples delivered on one side of the cutting line. The staple cartridge may be a single unitary piece or be comprised of two cartridges, one having two or three rows of staple pockets for delivering two or three rows of staples placed on one side of the blade <NUM> and a second staple cartridge having only one row of staple pockets for delivering only one row of staples on the other side of the blade <NUM>. The asymmetric stapler advantageously results in a smaller device with a decreased diameter of the end effector <NUM>. Alternatively, the saved space in the end effector <NUM> can be utilized to advantageously provide additional structural support in a device of the same diameter. While two to three rows of staples on both sides of the blade <NUM> may be preferred for holding living tissue, a specimen to be removed may only require one row of staples on one side of the cutting line designed for short term holding onto tissue to be removed. The resulting smaller device diameter would be beneficial in certain procedures such as in the removal of an endoluminal polyp. In such a procedure, the endoluminal polyp removal stapler would have two or three rows of staples on one side of the blade for delivering two or three rows of staples into the colon side of the cutting line and one row of staples for delivering one row of staples into the polyp side of the cutting line. Through the use of different number of staple rows on either side of the cutting line, the staplers can be tailored to their specific surgical applications. The result is a dramatic reduction in instrument size, in particular, the diameter of the end effector <NUM>, or alternatively an instrument with of same size but having increased instrument strength and reliability. <FIG> illustrates the resulting cut employing an asymmetrical stapler according to the present invention. <FIG> shows three lines <NUM> of staggered staples delivered into the organ side <NUM> and one line of staples <NUM> delivered into the removed tissue <NUM>. In order to provide to the surgeon user visual indication as to which side of the stapler <NUM> delivers fewer rows, the end effector <NUM> of the stapler <NUM> is color coded such that the side of the stapler <NUM> that has fewer rows of staples is colored a different color from the side of the stapler that has two or more rows of staples as shown in <FIG>. For example, the side of the stapler with a single line of staples is colored red and the other side of the blade is colored green. Other markings on the stapler <NUM> are possible. In another variation shown in <FIG>, the end effector <NUM> of the stapler is curved such that the surgeon knows to place the concave portion of the curvature against or on the side of the polyp <NUM>, for example, and the convex side of the curved end effector against the colon side <NUM>. The curved jaws assist the surgeon user in denoting proper orientation of the stapler with the concave side of the curvature having few rows of staples compared with the concave side of the blade which has a greater number of rows of staples. In another variation, the concave side of the stapler blade includes fewer rows of staples relative to the convex side of the stapler blade.

Turning now to <FIG>, the slider <NUM> will be described. The slider <NUM> includes a slider base <NUM> having a bottom surface <NUM> and a top surface <NUM>. At least a portion of the bottom surface <NUM> toward the distal end is curved to conform to the curved bottom <NUM> of the lower jaw <NUM>. At the proximal end of the slider <NUM>, the bottom surface <NUM> includes a recessed portion <NUM> sized and configured to receive the bottom portion <NUM> of the I-beam <NUM>. A slot <NUM> is formed in the slider base <NUM> that opens at the proximal end and extends toward the distal end of the slider base <NUM>. The slot <NUM> is sized and configured to receive at least the lower middle portion <NUM> of the I-beam <NUM>. In one variation, the front end of the slider <NUM> that leads distal translation includes a beveled or angled front surface to assist in urging staples from the device. Upstanding from the top surface <NUM> of the slider base <NUM> are at least two angled caming surfaces <NUM>. <FIG> depict a slider <NUM> that includes four upstanding angled caming surfaces 150a, 150b, 150c, 150d. An asymmetrical staple cartridge according to the present invention will have a slider <NUM> that corresponds to the number of staple rows on each side of the I-beam blade <NUM>. Two angled caming surfaces 150a, 150b are separated by an I-beam receiving portion <NUM> from the two angled caming surfaces 150c, 150d. The I-beam receiving portion <NUM> is sized and configured to receive the middle portion <NUM> of the I-beam <NUM>. Each caming surface <NUM> is approximately <NUM> (<NUM> inches) thick and includes an angled distal end. The angle of the caming surface <NUM> corresponds to the angle of the staple holding locations <NUM> and <NUM> which ranges from approximately <NUM>-<NUM> degrees wherein <NUM> degrees is a vertical caming surface <NUM>. The slider <NUM> is disposed inside the lower jaw <NUM> inside a lower passageway defined between the one or more staple cartridges <NUM> and the bottom cover <NUM>. The slider <NUM> is retained in the lower jaw <NUM> between the one or more staple cartridges <NUM> and bottom cover <NUM> yet the slider <NUM> is free to translate longitudinally distally and proximally with respect to the lower jaw <NUM>. The upwardly extending caming surfaces 150a and 150b extend upwardly through slots <NUM> and <NUM>, respectively, of the staple cartridge <NUM> on one side of the blade <NUM> of the I-beam <NUM>. The other two upwardly extending caming surfaces 150c and 150d extend upwardly through slots <NUM> and <NUM>, respectively, of the other side of the staple cartridge <NUM> or second staple cartridge <NUM> on the other side of the blade <NUM> of the I-beam <NUM>. The slider caming surfaces <NUM> are configured to contact staples residing inside staple pockets <NUM> and sequentially urge them out towards the anvil surface <NUM> of the upper jaw <NUM> as the slider <NUM> translates along the end effector <NUM>.

Turning now to <FIG>, a staple <NUM> according to the present invention will be described. The staple <NUM> is shown in its undeformed or open condition. The staple <NUM> includes a first leg <NUM> and a second leg <NUM> interconnected by a base <NUM>. The first leg <NUM> intersects with the base <NUM> at approximately <NUM> degrees and defines a first intersection <NUM>. The second leg <NUM> intersects with the base <NUM> at approximately <NUM> degrees and defines a second intersection <NUM>. The first leg <NUM> is longer than the second leg <NUM>. The staple <NUM> includes an inner surface <NUM> and an outer surface <NUM> interconnected by a first sidewall <NUM> and second sidewall <NUM>. The inner surface <NUM> intersects with the outer surface <NUM> at a first point <NUM> at the first leg <NUM> and at a second point <NUM> at the second leg <NUM>. The first point <NUM> and second point <NUM> are line intersections in <FIG> that are perpendicular to the length of the staple <NUM>. In another variation, the line intersections are parallel to the length of the staple <NUM>. In another variation, the first point <NUM> and/or the second point <NUM> are point intersections. In another variation, the first point <NUM> and/or second point <NUM> are planar surfaces or any other geometric shape that is suitable for puncturing and penetrating tissue through which the staple is delivered. The first leg <NUM> includes a first tip <NUM> at the free distal end of the first leg <NUM> and the second leg <NUM> includes a second tip <NUM> at the free distal end of the second leg <NUM>. The first and second tips <NUM>, <NUM> begin where the first and second legs <NUM>, <NUM>, respectively, begin to taper or decrease in cross-sectional area in the direction distally along the leg <NUM>, <NUM>.

With particular attention to <FIG>, the first leg <NUM> is approximately <NUM> (<NUM> inches) long and the second leg <NUM> is approximately <NUM> (<NUM> inches) long. The ratio of the shorter second leg <NUM> to the longer first leg <NUM> is approximately ½. The overall length of the base <NUM> is approximately <NUM> (<NUM> inches) and each leg <NUM>, <NUM> is perpendicular to the base <NUM>. The radius of curvature of the outer surface <NUM> at the first and second intersections <NUM>, <NUM> is approximately <NUM> (<NUM> inches). The distance between the first sidewall <NUM> and the second sidewall <NUM> or thickness of the staple is approximately <NUM> (<NUM> inches). The distance between the inner surface <NUM> and the outer surface <NUM> or width of the first and second legs <NUM>, <NUM> is approximately <NUM> (<NUM> inches). The distance between the inner surface <NUM> and the outer surface <NUM> or width of the base <NUM> is also approximately <NUM> (<NUM> inches). The first tip <NUM> includes a curved outer surface <NUM> having a radius of curvature of approximately <NUM> (<NUM> inches). This curve forms a concave outer surface <NUM> in the location of the first tip <NUM>. The inner surface <NUM> at the first tip <NUM> is perpendicular to the base <NUM> and intersects with the curved outer surface <NUM> at a line intersection defining the first point <NUM>. The second tip <NUM> includes an angled outer surface <NUM>. The portion of the outer surface <NUM> in the location of the second tip <NUM> is angled approximately <NUM> degrees from vertical towards the inner surface <NUM>. The portion of the inner surface <NUM> in the location of the second tip <NUM> is angled approximately <NUM> degrees from vertical towards the outer surface <NUM>. Together the angled outer surface <NUM> and the angled inner surface <NUM> in the location of the second tip <NUM> form an angle of approximately <NUM> degrees therebetween and define a line intersection at the second point <NUM>.

With particular attention to <FIG>, the staple <NUM> is shown in its deformed or closed configuration in which the first leg <NUM> is angled towards the second leg <NUM> to form a triangular shape or delta or D-shaped configuration. The triangular shape results when the first leg <NUM> is deformed as a result of urging the undeformed staple <NUM> from staple pockets <NUM> in the lower jaw <NUM> against the anvil surface <NUM> of the upper jaw <NUM> of the stapler <NUM> of the present invention. In this delta configuration, the second leg <NUM> remains upstanding and substantially perpendicular to the base <NUM> and the first leg <NUM> is deflected to towards the second leg <NUM> until the first and second tips <NUM>, <NUM> meet or are substantially in juxtaposition to each other. The resulting angle of the deflected first leg <NUM> with respect to the base <NUM> is approximately <NUM> degrees. In one variation, the staple has a circular cross-section. In another variation of the staple <NUM>, a stress concentration is formed in the first leg <NUM> to create a weaker location in the first leg <NUM> so that deformation, bending or deflection of the first leg <NUM> takes place in the location of the stress concentration. An example of a stress concentration is at least one notch formed in the inner surface <NUM> at a location along the first leg <NUM> to encourage bending of the first leg <NUM> to occur at the stress concentration. An example of stress concentration in the form of a notch <NUM> is shown in <FIG>. In another variation, stress concentrations such as one or more notches are strategically placed to effect a variety of closed staple shapes. For example, closed staple shapes are not limited to a triangular shaped staple but also include rectangular, square, rhombus, and trapezoid shapes. Furthermore, in another variation, notches are formed to capture one leg inside the notch formed in the opposite staple leg to create a locking variant in which the closed staple shape includes interlocked first and second legs configured resist forces that would open the staple from a closed and interlocked configuration.

Turning to <FIG>, the staple <NUM> is shown to include at least one barb <NUM>. In the variation shown in <FIG>, a single barb <NUM> is provided near the distal end of each leg <NUM>, <NUM> formed in the inner surface <NUM> of the staple <NUM>. Barbs assist in providing an increased mechanical hold of the staple into tissue and can be formed on either or both legs and on the inner surface <NUM> or outer surface <NUM>. Multiple barbs <NUM> along one of the legs are shown in <FIG>. In <FIG>, four barbs <NUM> are formed in the inner surface of the first leg <NUM> and one barb <NUM> is formed in the inner surface of the second leg <NUM>. Smaller barbs <NUM> such as micro and nano sized barbs are also within the scope of the present invention.

Turning now to <FIG>, there is shown a four-pronged staple <NUM>. The four-pronged staple <NUM> includes a longer first leg 154a interconnected to a shorter second leg 156a by a base 158a and a second longer first leg 154b interconnected to a shorter second leg 156b by a base 158b. Each pair of staple legs 154a, 156a and 154b, 156b and their interconnected bases 158a, 158b are substantially identical to the staple <NUM> depicted and described with respect to <FIG>, except in the four-pronged staple <NUM> the two pairs of legs are interconnected by a enlarged base portion <NUM> that has the same thickness as staple bases 158a, 158b which are approximately <NUM> (<NUM> inches) thick. The enlarged base portion <NUM> is connected to base 158a and base 158b and serves as a caming surface for engagement with a slider <NUM> that includes an enlarged angled slider caming surface <NUM>. The staple cartridge <NUM> is still formed in a similar manner as described with respect to <FIG> except that it is adapted to receive a wider staple having wider slots <NUM>, <NUM> to accommodate the wider four-pronged staple <NUM> and wider slider <NUM>. The cartridge <NUM> adapted for the four-pronged staple <NUM> is preferably similar to that described with respect to <FIG> in which the first plate <NUM> and second plate <NUM> include oppositely formed angled staple holding locations <NUM>, <NUM>, respectively. At least a portion of the first leg 154a, second leg 156a and base 158a is disposed in the staple holding location <NUM> of the first plate <NUM> and at least a portion of the first leg 154b, second leg 156b and base 158b is disposed in the staple holding location <NUM> of the second plate <NUM>. An additional third plate <NUM> may hold another row of four-pronged staples <NUM> between the third plate <NUM> and second plate <NUM> as described above with another slider caming surface <NUM> residing in the second slot <NUM>. The four-pronged staples <NUM> are angled to match the angle of the slider <NUM> caming surface <NUM> such that when the slider <NUM> is pushed forward by the translating I-beam <NUM>, the angled slider caming surface <NUM> contacts the enlarged base portion <NUM> of the staple <NUM> to urge the staple <NUM> upwardly and out of the cartridge <NUM> and against the anvil surface <NUM> of the upper jaw <NUM> where the staple <NUM> is deformed into tissue. The deformed staple includes two triangular shaped closures wherein the first legs 154a, 154b are bent towards the second legs 156a, 156b, respectively.

<FIG> illustrate various views of a four-pronged staple <NUM> that includes an even larger base portion <NUM> to provide additional strength to the staple <NUM>. The first and second tips 176a, 176b, 178a, 178b include angled first and second sidewalls 168a, 168b, 170a, 170b to form line intersections that are parallel to the length of the staple <NUM>. A four-pronged staple <NUM> having flat, blunt first tips 176a, 176b and second tips 178a, 178b are shown in <FIG>. The four-pronged staple <NUM> of <FIG> may be cut along dotted lines to form two single staples <NUM> having only two legs <NUM>, <NUM> each with flat first and second tips <NUM>, <NUM> as shown in <FIG>.

Turning now to <FIG>, there is shown a four-pronged staple <NUM> having notches <NUM> formed in the inner surface of first legs 154a, 154b. The notches <NUM> are curved semi-cylindrically shaped indentations that create stress concentrations in the legs 154a, 154b such that while being deformed the legs 154a, 154b will tend to bend in the location of the notches <NUM>. In the variation of the four-pronged staple <NUM> of <FIG>, the first tips 176a, 176b include curved outer surfaces 166a, 166b intersecting with straight inner surfaces 164a, 164b to form line intersections that are perpendicular to the length of the staple <NUM>. The second tips 178a, 178b are formed by angled outer surfaces 166a, 166b intersecting with straight inner surfaces 164a, 164b to form line intersections that are perpendicular to the length of the staple <NUM>. When deformed, the first legs 154a, 154b are bent at the notches <NUM> such that first tips 176a, 176b contact second tips 178a, 178b to form two connected triangular shaped closures.

With reference to <FIG>, a four-pronged staple <NUM> having staggered legs is shown. A first two-pronged staple having a longer first leg 154a interconnected to a shorter second leg 156a by a base 158a is connected via an angled enlarged planar base portion <NUM> to a second two-pronged staple having a longer first leg 154b interconnected to a shorter second leg 156b by a base 158b such that the first two-pronged staple is offset or staggered with respect to the second two-pronged staple. The first and second two pronged staples are substantially identical to the staple described above with respect to <FIG>. The angled base portion <NUM> interconnecting the two two-pronged staples allows the first two-pronged staple to be offset from the second two-pronged staple resulting in a four-pronged staple <NUM> with staggered legs 154a, 154b, 156a, 156b. The enlarged base portion <NUM> serves as a caming surface for caming against the angled caming surface <NUM> of the slider <NUM>. When actuated the two longer first legs 154a, 154b are deformed against the anvil surface <NUM> towards the second legs 156a, 156b, respectively, to form two triangular shaped closures capturing tissue therebetween. When an entire row of four-pronged staples <NUM> are deployed, the result is two effective rows of staggered staples.

Turning now to <FIG>, there is shown a six-pronged staple <NUM>. The six-pronged staple <NUM> includes a first two-pronged staple <NUM> connected to a second two-pronged staple <NUM> connected to a third two-pronged staple <NUM> in a staggered fashion. The first, second and third two-pronged staples <NUM>, <NUM>, <NUM> are substantially identical to the two pronged staple <NUM> of <FIG> described above. The first two-pronged staple <NUM> includes a longer first leg 154a interconnected to a shorter second leg 156a by a base 158a. The second two-pronged staple <NUM> includes a longer first leg 154b interconnected to a shorter second leg 156b by a base 158b. The third two-pronged staple <NUM> includes a longer first leg 154c interconnected to a shorter second leg 156c by a base 158c. Each of the two-pronged staples <NUM>, <NUM>, <NUM> is connected to each other at their bases 158a, 158b, 158c, respectively. The first two-pronged staple <NUM> is connected to the second two-pronged staple <NUM> by an angled extended base portion therebetween such that the first two-pronged staple <NUM> is offset from the second two-pronged staple <NUM>. The second two-pronged staple <NUM> is connected to the third two-pronged staple <NUM> by an angled extended base portion therebetween such that the second two-pronged staple <NUM> is offset from the third two-pronged staple <NUM>. The three two-pronged staples <NUM>, <NUM>, <NUM> are connected such that the first and third two-pronged staples <NUM>, <NUM> are in alignment with respect to each other and the middle second two-pronged staple <NUM> is offset relative to the first and third two-pronged staples <NUM>, <NUM>. The six-pronged staple <NUM> is loaded in an angled manner into a cartridge as described above with respect to <FIG>, and <FIG> wherein the first two-pronged staple <NUM> is disposed at least in part into a staple holding location <NUM> of the first plate <NUM> and the third two-pronged staple <NUM> is disposed at least in part into a staple holding location <NUM> of the second plate <NUM> such that the middle or second two-pronged staple <NUM> resides inside the first slot <NUM> together with a slider <NUM> having an enlarged caming surface <NUM> of the like described with respect to <FIG> against which the base portions engage for deployment. Of course a third-plate <NUM> with staple holding locations <NUM> is loaded with staples <NUM> in the same manner for engagement with a second slider <NUM> residing inside the second slot <NUM>. After the six-pronged staple <NUM> is urged by the slider against the anvil surface <NUM>, the first legs 154a, 154b, 154c are deflected towards the second legs 156a, 156b, 156c, respectively, to form three triangular shaped closures that capture tissue. These three triangular shaped closures are staggered with respect to each other yet interconnected to form a wide and strong stapling of tissue.

Referring now to <FIG>, another staple variation is shown. In this variation, the staple <NUM> includes a first leg <NUM> interconnected to a second leg <NUM> by a base <NUM>. The first leg <NUM> is substantially straight when undeformed and includes a first tip <NUM> having an angled or chamfered outer surface. The second leg <NUM> is slightly longer than the first leg <NUM>. The second leg <NUM> also includes an elbow <NUM> at which the second leg <NUM> is bent slightly towards the first leg <NUM> while in the undeformed condition as shown in <FIG>. The second leg <NUM> includes a second tip <NUM> which in one variation commences to taper from the elbow <NUM>. Since the staple <NUM> is disposed inside a cartridge at an angle as described above, when the staple <NUM> is urged upwardly by an advancing slider (not shown), both the first and second tips <NUM> and <NUM> contact the flat anvil surface <NUM> substantially simultaneously as shown in <FIG>. Continued urging of the staple <NUM> into the anvil surface <NUM> results in the first leg <NUM> bending towards the second leg <NUM> and the second leg <NUM> bending towards the first leg <NUM> as shown in <FIG>. The angled or chamfered outer surface at the first tip <NUM> assists in directing the first leg <NUM> towards the second leg <NUM>. The elbow <NUM> and angled second leg <NUM> assist in directing the second leg <NUM> towards the first leg <NUM>. Because the staple pockets <NUM> retain the staples <NUM> at an angle to the flat anvil surface <NUM>, the second leg <NUM> has to be slightly longer and angled such that the portion of the second leg <NUM> that is distal to the elbow <NUM> is substantially perpendicular to the flat anvil surface <NUM> when the second tip <NUM> contacts the flat anvil surface <NUM>. This variation advantageously does not require anvil pockets formed in the anvil surface and precise alignment of the staple legs <NUM>, <NUM> with anvil pockets to effect deflection of staple legs <NUM>, <NUM> towards each other. Such deflection is accomplished against a flat anvil surface <NUM>.

With reference to <FIG>, there is shown a plurality of staples <NUM> connected to a backbone <NUM> illustrating the formation of staples <NUM> in a fishbone style for ease of manufacturing, assembly and handling. A sheet of metal such as surgical steel, stainless steel, or titanium is provided and a plurality of staples <NUM> is cut into the sheet of metal on a wire electrical discharge machining (EDM) machine. The staples <NUM> may also be formed utilizing a micro-water jet, photo etching or by stamping. The staples <NUM> remain connected to the backbone <NUM> via narrow connecting tabs <NUM> until the staples <NUM> are broken off at the tabs <NUM> and then loaded into a staple cartridge. After a staple <NUM> is broken off a portion of the connecting tab <NUM> remains attached to the staple <NUM>. The remnant tab <NUM> serves as a barb <NUM> for increasing mechanical holding onto tissue captured inside a closed staple <NUM> after deployment. Therefore, the staple <NUM> is manufactured without the need for post-processing such as bending and sharpening. Also, the backbone <NUM> can be an aid in the storage of staples <NUM> and in the assembly of staple cartridges.

Turning to <FIG>, a staple cartridge <NUM> in the form of a single unit is inserted into the staple cartridge receiving portion <NUM> of the lower jaw <NUM>. The staple cartridge <NUM> may also be in the form of two units 52a, 52b with each unit having two slots <NUM>, <NUM> with two rows of staples <NUM> residing inside staple pockets <NUM>. An asymmetrical cartridge as described above can also be employed. The staple cartridge <NUM> is inserted such that the grooves <NUM>, <NUM>, <NUM> of first, second and third plates <NUM>, <NUM>, <NUM>, respectively, engage the tongue <NUM> at the proximal end of the lower jaw <NUM> and the tongues <NUM>, <NUM>, <NUM> of the first, second and third plates <NUM>, <NUM>, <NUM>, respectively, engage the ledge <NUM> at the distal end of the lower jaw <NUM>. A cartridge retainer <NUM> is connected covering the tongues <NUM>, <NUM>, <NUM> as shown in <FIG> to secure the cartridge in position. Each cartridge <NUM> can include a cover slip of paper (not shown) covering the staple pockets <NUM> to retain the staples <NUM> inside the pockets <NUM> during storage and handling. The cover slip is then removed by peeling away just prior to or after installation of the cartridge <NUM>. Each cartridge <NUM> also contains a slider <NUM> disposed inside the cartridge <NUM> such that the angled caming surfaces 150a, 150b of the slider <NUM> reside in slots <NUM>, <NUM>, respectively on one side of the I-beam receiving portion <NUM> and the angled caming surfaces 150c, 150d of the slider <NUM> reside in slots <NUM>, <NUM>, respectively on the other side of the I-beam receiving portion <NUM>. One side of the cartridge 52a is spaced apart from the other side of the cartridge 52b to create a central passageway <NUM> to allow passage of the translating I-beam <NUM>.

Another variation of cartridge <NUM> installation is shown in <FIG>. In this variation, the front or distal end of the lower jaw <NUM> is open and the cartridge <NUM> includes rails <NUM> that engage tracks <NUM> formed in the staple cartridge receiving portion <NUM> of the lower jaw <NUM>. The cartridge <NUM> slides in through the open distal end of the lower jaw <NUM> which is then closed with a cap or latch (not shown). The cartridge <NUM> is shown to include a top plate <NUM> which increases the strength across the width of the device. After the staples <NUM> are expended, the staple cartridge <NUM> can be removed and disposed and a new cartridge inserted for continued stapling. In another variation, the staple cartridge <NUM> is pre-installed inside the stapler cartridge assembly <NUM> and after the staples <NUM> are expended the entire stapler cartridge assembly <NUM> is removed and disposed and a new stapler cartridge assembly <NUM> is connected to the handle assembly <NUM> for continue stapling.

With the stapler cartridge assembly <NUM> connected to the handle assembly <NUM>, the actuator shaft <NUM> connects to the actuator shaft <NUM> inside the handle assembly <NUM>. The handle assembly <NUM> is then used to operate the stapler <NUM> in three different functions or modes of operation. The first mode allows the user to open and close the jaws <NUM>, <NUM> of the end effector <NUM>. The second mode fires the staples and the third mode of operation returns the I-beam <NUM> to its original proximal position following the firing of staples.

With reference to <FIG>, the handle <NUM> is connected to a forward driver <NUM> which engages a forward tooth on the actuator shaft <NUM>. When the handle <NUM> is depressed, the actuator <NUM> is moved slightly forward which in turn moves the actuator shaft <NUM> of the stapler cartridge assembly <NUM> forward. Since the actuator shaft <NUM> is connected to the I-beam <NUM>, the I-beam <NUM> advances forward with the depression of the handle <NUM>. As the I-beam <NUM> advances, the beveled front end <NUM> of the top portion <NUM> of the I-beam <NUM> enters the passageway <NUM> in the upper jaw <NUM> which deflects the open and spring biased upper jaw <NUM> downward from an open position to a closed position as shown in <FIG>. The upper jaw <NUM> is connected to the lower jaw <NUM> with a pin such that the upper jaw <NUM> pivots with respect to the lower jaw <NUM>. Springs (not shown) are included to create a spring bias that urges the upper jaw <NUM> in an open position with respect to the lower jaw <NUM>. The top portion <NUM> of the I-beam <NUM> is shown entering the passageway <NUM> in <FIG> with the jaws biased in an open position. In <FIG>, the top portion <NUM> of the I-beam <NUM> has entered the passageway <NUM> and moved the upper jaw <NUM> into a closed orientation with respect to the lower jaw <NUM>. When the handle <NUM> is released the actuator shafts <NUM>, <NUM> move proximally pulling the I-beam <NUM> also proximally allowing the spring bias to open the jaws as the top portion <NUM> exits the passageway <NUM>. The user can open and close the jaws of the end effector <NUM> by pressing and releasing the handle <NUM> to position the targeted tissue between the upper and lower jaws of stapler <NUM>. The end effector <NUM> is shown in an open position in <FIG> and in a closed position in <FIG> in which the distance across the gap between the upper jaw <NUM> and lower jaw <NUM> is approximately <NUM> (<NUM> inches) when in the closed position.

After the jaws are closed in position at the targeted tissue location, the stapler <NUM> is switched to operate in fire mode by depressing a fire button <NUM> on the handle assembly <NUM> as shown in <FIG>. The fire button <NUM> disengages an open driver <NUM> from the actuator shaft <NUM> as shown in <FIG> freeing it for longitudinal movement. The open driver <NUM> is shown engaged with the teeth of the actuator shaft <NUM> in <FIG>. In <FIG>, the open driver <NUM> is shown disengaged from the teeth of the actuator shaft <NUM> with the fire button <NUM> depressed. With the open driver <NUM> disengaged, the trigger handle <NUM> swings out and the forward driver <NUM> engages with forward teeth on the actuator <NUM>. Depressing the handle <NUM> advances the actuator shaft <NUM> forward as the forward driver <NUM> freely engages teeth with each squeeze of the trigger handle <NUM>. The handle <NUM> is squeezed multiple times to advance the I-beam <NUM> all the way to the distal end of the cartridge <NUM>. The handle assembly <NUM> may also include a rotatable rack.

Turning now to <FIG>, there is shown the end effector <NUM> with the jaws <NUM>, <NUM> in a closed position. As the I-beam <NUM> is advanced distally, the top portion <NUM> of the I-beam <NUM> travels in the upper passageway <NUM> and the bottom portion <NUM> of the I-beam <NUM> enters the slot <NUM> of the slider <NUM> engaging with the slider <NUM> and pushing it distally. As the angled caming surface <NUM> leads, it contacts staples (not shown) to urge them out of staple holding locations <NUM>. The blade <NUM> of the I-beam <NUM> resides in the gap <NUM> between the upper jaw <NUM> and the lower jaw <NUM> cutting tissue captured between the jaws in between tissue resolved with two or more rows of staples on either side of the blade <NUM>.

<FIG> illustrate the deployment of staples <NUM> as the slider <NUM> and I-beam <NUM> advance in the distal direction. The staples <NUM> are disposed inside staple pockets <NUM> such that at least a portion of the staple <NUM> rests against U-shaped staple holding locations <NUM> such that the longer first leg <NUM> is located proximally relative to the shorter second leg <NUM>. As the slider <NUM> advances, the angled caming surfaces <NUM> sequentially contact the staples. In one variation, a beveled front end <NUM> of the slider <NUM> contacts that portion of the outer surface <NUM> of the staple <NUM> such as the base <NUM> of the staple <NUM> that is in the gap <NUM> in the bottom wall <NUM> of the U-shaped staple holding location <NUM> and urges the staple <NUM> upwardly. As the slider <NUM> advances the angled caming surfaces <NUM> of the slider <NUM> contact the staples <NUM> and continue to urge them sequentially upwardly with distal translation of the slider <NUM>. With sufficient deployment height, the longer first leg <NUM> of the staple <NUM> contacts the flat anvil surface <NUM> of the upper jaw <NUM>. In particular, the first tip <NUM> contacts the flat anvil surface <NUM>. Because the first tip <NUM> includes a curved, chamfered or beveled outer surface <NUM>, contact of this curved outer surface with the flat anvil surface <NUM> assists in bending the first leg <NUM> towards the second leg <NUM>. The curved outer surface <NUM> of the first tip <NUM> slides against the flat anvil surface <NUM> as the first leg <NUM> bends into a closed triangular configuration. The shorter second leg <NUM> is not bent or deformed. Unlike a conventional staple, which is fired with the staple legs perpendicular to the forming anvil, the staple of the present invention is fired at an angle with respect to a flat anvil surface <NUM>. There are no staple forming pockets in the anvil surface of the present invention. As the long leg <NUM> contacts the flat anvil surface <NUM>, the tip <NUM> of the long leg <NUM> slides freely along the anvil surface while the staple <NUM> is progressively pushed normal to the staple base <NUM> because the staple is at the same angle as the angled caming surface <NUM> of the slider <NUM> until the tip <NUM> of the long leg <NUM> meets the tip of the shorter second leg <NUM> and the staple is closed capturing tissue inside the triangular shaped closure. The closure force of the staple <NUM> of the present invention is advantageously relatively low when compared to conventional staples because only one leg is being deformed, the longer first leg <NUM>; whereas, in conventional staplers, both legs of a staple are deformed simultaneously. Furthermore, closure forces are further reduced by the fact that the long leg is simply being bent over as opposed to being forced to buckle against an anvil pocket. Buckling forces of a beam are much greater than bending forces and conventional staples require the buckling of two staple legs simultaneously. Conventional stapling devices require high firing forces to apply the staple lines. The staple legs are forced perpendicular to the anvil pockets forcing them to buckle. These high forces apply significant stresses to the device components and can cause fatigue for the user. Therefore, the present stapler <NUM> greatly reduces forces required to deploy and deform staples. The staple forming forces of the present invention are relatively low when compared with conventional staple designs. Since only a single leg bends over in contact with the anvil surface, the user and device is benefited through reduced stresses on the components and reduced actuation forces for the user.

The staple deployment method of the present invention drives a slanted slider down the jaws of the stapling device. The slider <NUM> comes in direct contact with the staples <NUM> as it passes through the same space as the staples being deployed. The staples are partially held in place by pockets <NUM> in the interior jaws or cartridge <NUM> of the device. These pockets provide guidance for the staples as they are pushed out of the device and formed into tissue. The staples are held in the cartridge in such a way that only part of the staple thickness is resting in a pocket while the other part is in an open channel that is coplanar with the slider <NUM>. One side of the staple is held against the first plate inside staple receiving locations <NUM> while the other side of the staple is held against the smooth wall of the second plate or, alternatively, in staple holding locations <NUM> also formed in the second plate. Each slider caming surface <NUM> travels down the center of the staple in each slot <NUM>, <NUM>. As the slider <NUM> is pushed distally along the length of the jaw, the angled slider ramp drives the staples out of the guided cartridge pockets. The angled caming surface <NUM> of the slider pushes normal to the staple base <NUM>. The slider only contacts a part of the staple, while the remaining part of the staple is held against the staple holding locations <NUM> which serve as guides directing the staple out of the cartridge.

Turning now to <FIG>, after the staples are fired, the handle assembly <NUM> is switched into the third mode of operation in which the I-beam <NUM> is returned proximally to its starting position. A gear switch button <NUM> is depressed which rotates the actuator shaft <NUM><NUM> degrees so that the reverse teeth on the actuator <NUM> come into contact with the reverse driver <NUM>. The reverse driver <NUM> is connected to the handle <NUM> by a series of gears. When the handle <NUM> is squeezed, the reverse driver <NUM> pulls the actuator <NUM> and I-beam <NUM> back. The trigger handle <NUM> is squeezed multiple times to return the I-beam <NUM> to its original position. The I-beam <NUM> is returned to its original proximal position to open the jaws <NUM>, <NUM>. With the I-beam <NUM> returned, the slider <NUM> is left in its distal fired position. <FIG> illustrates, the I-beam <NUM> returned and fully retracted resulting in the spring biased upper jaw <NUM> becoming open while the slider <NUM> is left in its distal location allowing the stapled tissue to be released from the jaws. When the actuator <NUM> and I-beam <NUM> is returned, the stapler cartridge assembly <NUM> can be detached from the handle assembly <NUM> and new stapler cartridge assembly <NUM> can be attached to continue stapling.

The conventional laparoscopic stapler is currently approximately <NUM> millimeters in diameter which requires a larger sized cannula for insertion and, hence, a larger incision in the patient. The laparoscopic stapler <NUM> of the present invention has a diameter of approximately <NUM> (<NUM> inches) as shown in <FIG> which will advantageously fit inside smaller diameter cannulas that require smaller incisions in the patient. The smaller incision results in less pain, faster patient recovery times and a smaller scar visible after the operation. <FIG> illustrates that the I-beam <NUM> substantially defines the diameter of the end effector <NUM>. Approximately a little less than half the diameter of the device is consumed with the upper jaw and gap between the upper and lower jaw leaving approximately half the diameter of the device, approximately <NUM> (<NUM> inches) for housing the staples and mechanisms for staple deployment including the slider.

The problem presented in traditional staplers is that they require larger diameters and larger incisions as well as higher firing forces in order to deploy staples. This is due to the fact that traditional staples require a pusher to deploy staples. The pusher is an intermediate caming surface disposed between each staple and the slider. Typically, each pusher is of equal height as the staple and resides directly below the staple. The height of the pusher has to be approximately equal to the height of the staple in order to fully urge the staple out of the staple pockets and into the gap between the upper and lower jaws. The pusher typically includes an angled lower surface that cams against an angled slider. The upper surface of the pusher is typically flat and horizontal and cams normal to the base of the staple. In essence, the pusher takes up valuable space when trying to achieve a smaller stapler that will fit in a smaller sized cannula which is typically called a <NUM> millimeter cannula. The present invention successfully eliminates the pusher altogether due to the angled positioning of the staple such that the base of the staple is parallel to the angled caming surface of the slider. Because the staple of the present invention is placed at an angle, the horizontally traveling slider comes in direct contact with the staple during deployment without having any additional pusher between the staple and slider. Because there is no pusher required in the present invention, a great deal of space is saved resulting in a much smaller diameter device.

It is not just a matter of reducing staple size but also effectively deploying staples that form a closed staple configuration capable of holding tissue in a manner that is just as strong as a conventional stapler and doing so in a reliable and repeatable manner that is an important factor achieved by the stapler of the present invention. Another problem of conventional staplers that the present invention addresses and successfully avoids pertains to the anvil surface. Traditional anvil surfaces include detailed anvil pockets formed in the anvil surface. These anvil surface formations are necessary in order to reliably and repeatedly form staples in conventional staplers. The anvil surface is especially important as traditional staples are placed normal to the anvil surface and without anvil surface formations to guide the buckling staple legs the staple legs would splay in any direction and not form a nice closure important for securing tissue. Furthermore, the anvil pockets of traditional staplers require that the anvil of the upper jaw be perfectly aligned with the staple pockets and in particular, the staples residing in the pockets in order to effect perfect staple formation. Anvil surface formations or pockets are a necessity for staple formation reliability; however, they also increase manufacturing costs that result from not only forming detailed surface formation but also in making sure the anvil surface formations are in alignment with the staple trajectory. The present invention advantageously eliminates anvil surface formations and provides a smooth, flat anvil surface against which the staple legs are deformed. Typically, without anvil surface formations the staple legs would splay in any direction and not form a perfect closure. However, the present invention provides for angled staple holding locations that hold the staple at an angle with respect to the anvil surface. Furthermore, the staple has one longer leg and a shorter leg. As a result of this design, as the staple is ejected from the lower jaw, it is the longer leg that leads staple ejection. Because the longer leg leads, this leg will be the first leg to contact the anvil surface and instead of splaying in any direction the first leg is reliably bent towards the second leg. Misalignment of staple tips is eliminated because as the longer leg is being deformed against the flat anvil surface the remaining portion of the staple including the shorter leg remains substantially contained and guided in the staple pocket or staple holding location and prevented from lateral displacement that would result in a malformed staple. Also, the tip of the longer leg is curved or chamfered which provides a predilection for the staple to bend towards the second leg. Also, the curved tip allows the tip of the longer leg to slide against the smooth anvil surface as the longer leg of the staple is being deformed. Hence, the present invention not only reduces the overall diameter of the end effector, it also does so without sacrificing staple formation repeatability and reliability.

The problem of fitting a surgical stapler into a <NUM> cannula is solved by the absence of intermediate caming portions that are also known as "pushers" located between the slider and the staple. Typically, the legs of a staple are located in receiving pockets such that they are perpendicular to the anvil. The angled slider contacts the pushers which then contact the staple to drive it out of the staple pocket. Without an intermediate caming portion or pusher, the slider would have to contact the staple directly risking angular forces upon the staple that would angulate the staple legs out of alignment with the anvil surface formations resulting in malformed staples or angulate the staple legs with respect to the pocket resulting in the staple jamming against the pocket. Typically, the staples are stacked above the pushers. Therefore, removal of pushers saves tremendous space in the design and angled staples contact an angled slider directly. The elimination of pushers also further reduces manufacturing costs as the number of components is reduced and eases manufacturing as pushers are no longer required to be assembled. The angled orientation of the staples themselves is also a tremendous space saver as opposed to the staples being vertically oriented as in traditional staplers. Since there is no target pocket or anvil surface formation for the staple legs to come into contact with, the reliability of staple formation is greatly improved as the staple is free to deform against a smooth anvil surface without risking misalignment with anvil pockets as in traditional staplers. Valuable space is also saved by the slider moving through the same space or slots in which the staples reside.

Turning now to <FIG>, there is shown another variation of a staple cartridge <NUM> similar to that described above with respect to <FIG> wherein like numbers are used to describe like parts. As described above, the cartridge <NUM> comprises at least two plates sandwiched together to form a single row of staple receiving pockets with additional plates added to increase the desired number of staple rows. The outer surface <NUM> of the first plate <NUM> is smooth and the inner surface <NUM> is formed with a plurality of staple holding locations <NUM>. The staple holding locations <NUM> are recesses formed in the inner surface <NUM> of the first plate <NUM>. Each staple holding location <NUM> is substantially U-shaped and defined by a front sidewall <NUM> formed oppositely and substantially parallel to a rear sidewall <NUM>. The rear sidewall <NUM> is interconnected to a bottom wall <NUM> forming an L-shaped wall defining a gap <NUM> between the bottom wall <NUM> and the front sidewall <NUM>. In one variation, no gap <NUM> is formed. Instead, the bottom wall <NUM> interconnects with both the front sidewall <NUM> and rear sidewall <NUM> to form a complete U-shaped staple holding location <NUM>. The U-shaped staple holding locations are angled approximately <NUM>-<NUM> degrees with <NUM> degrees being a vertical non-angled orientation. <FIG> illustrates the U-shaped staple holding location being at <NUM> degrees or substantially perpendicular. The recessed wall <NUM> is recessed with respect to the inner surface <NUM>. Segments of the inner surface <NUM> that are located between the staple holding locations <NUM> include a plurality of horizontal grooves <NUM> that extend between the staple receiving locations <NUM>. The grooves <NUM> are rectangular and have square or rectangular cross-sections. The grooves <NUM> have a depth equal to the depth of the recessed wall <NUM>. The grooves <NUM> are separated by lands <NUM> that constitute the inner surface <NUM> and therefore are equal in height to the inner surface <NUM>. The grooves <NUM> stretch across the entire length of the first plate intersecting each sidewall <NUM>, <NUM> and bottom wall <NUM> of the staple holding locations <NUM>. The staple holding locations <NUM> are configured for partially receiving and holding a complementary, substantially U-shaped staple that is thicker than the thickness of the grooved sidewalls <NUM>, <NUM>, <NUM>. In one variation, the staple holding locations <NUM> receive the entire thickness of a complementarily U-shaped staple as shown in <FIG> such that no portion of the staple <NUM> resides outside the staple holding location <NUM>. The slider <NUM> includes an angled caming surface <NUM> with a side surface that is also formed with a plurality of horizontal grooves <NUM> forming channels for receiving the upstanding lands <NUM> that are located between staple holding locations <NUM>. A second plate <NUM> or shim is not shown in <FIG> but together with the first plate <NUM> define a slot <NUM> therebetween inside which the angled caming surface <NUM> of the slider <NUM> is capable of translating interconnected on the side surface with interlocked grooves <NUM> and lands <NUM>. Because a staple <NUM> is resident in a grooved staple receiving portion <NUM>, the angled caming surface <NUM> of the slider <NUM> is still able to contact the outer surface <NUM> of the staple <NUM> as the angled caming surface <NUM> translates through the grooves <NUM> to urge staple <NUM> upwardly and out. The grooved inner surface <NUM> of the first plate <NUM> advantageously allows the use of very thin staples; for example, staples that are the same depth as the staple pocket depth or depth of the staple holding location <NUM>. The depth of the staple pocket is approximately <NUM> ( <NUM> inches) which is also the thickness of the staple <NUM> that can be used in this variation of the invention. Therefore, the grooved plate <NUM> not only allows for extremely thin staples, it further reduces the size of the staple or allows additional space for structures that make the end effector stronger.

The stapler of the present invention is particularly suited for laparoscopic procedures; however, the invention is not so limited and the stapler of the present invention can be used in open surgical procedures equally effectively. In laparoscopic procedures, the stapler of the present invention can be used, for example, for the closure and anastomosis of tissue such as colon, small intestines, and stomach.

Claim 1:
A surgical stapler comprising:
a cartridge assembly (<NUM>) having a proximal end and a distal end; and
a jaw assembly (<NUM>) at the distal end of elongate shaft assembly;
the jaw assembly (<NUM>) comprising:
a first jaw (<NUM>) having an anvil surface (<NUM>);
a second jaw (<NUM>); the first jaw (<NUM>) being movable relative to the second jaw (<NUM>) and having a closed position in which the anvil surface (<NUM>) is adjacent to the second jaw (<NUM>) and a gap is defined between the second jaw (<NUM>) and the anvil surface (<NUM>); the second jaw (<NUM>) comprising a staple cartridge receiving portion (<NUM>); and
a staple cartridge (<NUM>) positionable in the staple cartridge receiving portion (<NUM>), characterized in that the staple cartridge (<NUM>) comprises:
a first plate (<NUM>), a second plate (<NUM>), and a third plate (<NUM>) connected together, the first plate (<NUM>) having an inner surface (<NUM>) and an outer surface (<NUM>) opposite the inner surface (<NUM>), the first plate (<NUM>) comprising a plurality of staple holding locations (<NUM>) formed therein, each staple holding location (<NUM>) defined by a recess formed in the inner surface (<NUM>) of the first plate (<NUM>); and
a plurality of staples (<NUM>) positioned in the plurality of staple holding locations (<NUM>).