Knife bar for surgical instrument

[0001] 1. Technical field

[0002] The present disclosure relates generally to surgical instruments and, more specifically, to surgical instruments for surgically joining tissue.

[0003] 2. Background of Related Art

[0004] Surgical stapling instruments used for applying parallel rows of staples through compressed living tissue are well known in the art. These surgical instruments are commonly employed for closing tissue or organs prior to transaction or resection, for occluding organs in thoracic and abdominal procedures, and for fastening tissue in anastomoses.

[0005] Typically, such surgical stapling instruments include an anvil assembly, a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the anvil and cartridge and anvil assemblies, and a firing mechanism for ejecting the surgical staples from the cartridge assembly.

[0006] In use, a surgeon generally initially approximates the anvil and cartridge members. Next, the surgeon can fire the instrument to place staples in tissue. Additionally, the surgeon may use the same instrument or a separate to cut the tissue adjacent or between the row(s) of staples. Alternatively, the surgical stapling instrument can sequentially eject the staples while the anvil approximates the cartridge.

[0007] The present disclosure relates to a surgical instrument for surgically joining tissue. Generally, this surgical instrument includes a handle assembly, an elongate member extending distally from the handle assembly, an end effector (e.g., having a curved shape) disposed adjacent a distal portion of the elongate member, and an actuation assembly operatively associated with the handle assembly. The actuation mechanism includes a thrust bar disposed at least partially within the elongate member and a distal slide member. The thrust bar has a proximal portion, a distal portion, a first lateral side and a second lateral side and is configured to move between proximal and distal positions with respect to the handle assembly. The distal slide member is positioned adjacent the first lateral side of the thrust bar and is adjacent the distal portion of the thrust bar. The proximal portion of the distal slide member is adapted to slide relative to the thrust bar when thrust bar moves in a curvilinear direction.

[0008] In certain embodiments, the proximal portion of the thrust bar extends proximally beyond a proximal-most end of the distal slide member.

[0009] The surgical instrument may further include a proximal slide member positioned adjacent the first lateral side of the thrust bar. In some embodiments, a distal portion of the proximal slide member is rigidly affixed to the thrust bar. In various embodiments, a distal-most end of the proximal slide member is positioned proximally of a proximal-most end of the thrust bar.

[0010] The surgical instrument may further include an actuation mechanism disposed in mechanical cooperation with the thrust bar and the handle assembly. The actuation mechanism is configured to move the thrust bar between the proximal and distal positions upon actuation of the handle assembly.

[0011] In addition, the surgical instrument may include a knife operatively coupled to the distal end portion of the thrust bar. The knife moves between a proximal position and a distal position in response to a translation of the thrust bar.

[0012] The surgical instrument may further include a second distal slide member positioned adjacent the second lateral side of the thrust bar.

[0013] Moreover, the surgical instrument may further include a second proximal slide member positioned adjacent the second lateral side of the thrust bar.

[0014] The present disclosure further relates to an actuation assembly for use with a surgical instrument. Briefly, the actuation assembly includes a thrust bar including a proximal portion, a distal portion, a first lateral side and a second lateral side and is configured to move between proximal and distal positions with respect to a handle assembly of the surgical instrument. The distal slide member is positioned adjacent the first lateral side of the thrust bar and is adjacent the distal portion of the thrust bar. The proximal portion of the distal slide member is adapted to slide relative to the thrust bar when thrust bar moves in a curvilinear direction.

[0015] In some embodiments, the proximal portion of the thrust bar extends proximally beyond a proximal-most end of the distal slide member.

[0016] The actuation assembly may further include a proximal slide member positioned adjacent the first lateral side of the thrust bar. In various embodiments, a distal portion of the proximal slide member is rigidly affixed to the thrust bar. In several embodiments, a distal-most end of proximal slide member is positioned proximally of a proximal-most end of the thrust bar.

[0017] The actuation assembly may further include a knife operatively coupled to the distal end portion of the thrust bar. The knife moves between a proximal position and a distal position in response to a translation of the thrust bar.

[0018] The actuation assembly may further include a second distal slide member positioned adjacent the second lateral side of the thrust bar. In addition, the actuation assembly may include a second proximal slide member positioned adjacent the second lateral side of the thrust bar.

[0019] The actuation assembly may further include knife attached to the distal portion of the thrust bar.

[0026] Embodiments of the presently disclosed surgical instrument are described in detail with reference to the drawings, wherein like reference numerals designate similar or identical elements in each of the several views. In the drawings and the description that follows, the term “proximal” refers to the end of the surgical instrument that is closest to the operator, whereas the term “distal” refers to the end of the surgical instrument that is farthest from the operator. As appreciated by one skilled in the art, the depicted surgical instrument fires staples, but it may be adapted to fire any other suitable fastener such as clips and two-part fasteners. Additionally, the disclosed actuation assembly may be used with an electrosurgical forceps. Further details of electrosurgical forceps are described in commonly-owned patent application Ser. No. 10/369,894, filed on Feb. 20, 2003, entitled VESSEL SEALER AND DIVIDER AND METHOD OF MANUFACTURING THE SAME, the entire contents of which are hereby incorporated by reference herein.

[0027] With reference to FIG. 1, reference numeral 100 designates an embodiment of the presently disclosed surgical instrument. In the interest of brevity, the present disclosure focuses on an actuation assembly of surgical instrument 100. U.S. Patent Applications Publication Nos. 2008/0105730, filed on Nov. 28, 2007; 2008/0110960, flied on Jan. 8, 2008; 2008/0142565, filed on Jan. 24, 2008; 2008/0041916, filed on Oct. 15, 2007; 2007/0187456, filed on Apr. 10, 2007; U.S. Provisional Patent Application Ser. No. 61/050273, filed on May 5, 2008; and U.S. Pat. Nos. 7,407,076 and 7,097,089 describe in detail the structure and operation of other surgical fastening assemblies. The entire contents of these prior applications and issued patents are incorporated herein by reference. Any of the surgical instruments disclosed in the cited patent applications may include the presently disclosed actuation assembly.

[0028] Surgical instrument 100 is configured to clamp, fasten, and/or cut tissue. In general, surgical instrument 100 includes a handle assembly 160, an elongate portion 120 extending distally from handle assembly 160 and defining a longitudinal axis “A-A,” and a tool assembly 150 adapted to clamp, cut, and join tissue. Elongate portion 120 has a proximal portion 122 and a distal portion 124 and operatively couples handle assembly 160 with tool assembly 150. In one embodiment, elongate portion 120 is made of a flexible material capable of bending. During use, a user can bend elongate portion 120 to reach the target tissue. Tool assembly 150 includes end effector 154, which may be configured to articulate relative to longitudinal axis A-A upon actuation of an articulation knob 166. It is envisioned that any other mechanism or means may be utilized to articulate end effector 154. End effector 154, which is disposed adjacent distal portion 124 of elongated portion 120, includes a first jaw member 130 and a second jaw member 140. First and second jaw members 130, 140 have has a curved shape with respect to longitudinal axis A-A. It is envisioned that curved jaw members may facilitate performing certain types of surgical procedures. For example, curved jaw members, as compared to straight jaw members (such as the jaw members illustrated in FIG. 1), may help facilitate access to lower pelvis regions, e.g., during lower anterior resection (“LAR”). At least one of the jaw members 130, 140 is adapted to move relative to the other jaw member (130 or 140) between spaced and approximated positions, e.g., upon actuation of handle assembly 160. However, it is also envisioned that other methods of approximating the jaw members are also usable, including sliding a clamp bar 168. In the illustrated embodiment, first jaw member 130 contains a cartridge assembly 132, while second jaw member 140 includes an anvil assembly 142.

[0029] Handle assembly 160 includes a stationary handle 162 and a movable handle 164. Movable handle 164 is adapted to move pivotally toward or away from stationary handle 162. Further, movable handle 164 is operatively connected to a jaw member (e.g., second jaw member 140) through a mechanism adapted to convert at least a partial actuation of movable handle 164 into a pivoting motion of at least one of cartridge assembly 132 and anvil assembly 142 between spaced and approximated positions. As recognized by one skilled in the art, any conventional actuation mechanism may be employed to operatively couple movable handle 164 to tool assembly 150.

[0030] Cartridge assembly 132 has a tissue-contacting surface 134 and a plurality of fastener retaining slots 136. Tissue-contacting surface 134 generally faces anvil assembly 142 and, during operation, engages tissue when the anvil assembly 142 is approximated with cartridge assembly 132. Fastener retaining slots 136 are arranged in rows along tissue contacting surface 134. Each fastener retaining slot 136 is adapted to hold a fastener (not shown) until a user actuates handle assembly 160 (see FIG. 1), for example. In an envisioned embodiment, when movable handle 164 is pivoted toward stationary handle 162, the fasteners are ejected from fastener retaining slots 134 and move toward anvil assembly 142.

[0031] In addition to fastener retaining slots 134, cartridge assembly 132 has a knife channel 138 adapted to slidably receive a knife 192 (see FIG. 2) or any other suitable cutting tool such as a blade. Knife channel 138 is disposed between rows of fastener retaining slots 136 and extends along tissue-contacting surface 134. In operation, knife 192 slides through knife channel 138, e.g. in response to movable handle 164 pivoting toward stationary handle 162. Alternatively, other mechanisms can be used to drive knife 192 through knife channel 138.

[0032] Referring to FIGS. 2-3, reference numeral 180 designates an actuation assembly for driving knife assembly 190 along knife channel 138. Knife assembly 190 is coupled to a distal portion 184 of actuation assembly 180 and includes a knife mount 194, which supports a blade or knife 192. At least a portion of actuation assembly 180 is made of a flexible material capable of bending. In operation, knife 192 is distally translatable between first and second jaw members 130, 140 (e.g., to sever tissue) as actuation assembly 108 moves distally. When actuation assembly 180 moves distally (e.g., in response to an actuation of handle assembly 160 or a distal motion of clamp bar 168), knife 192 translates along knife channel 138.

[0033] Actuation assembly 180 is operatively associated with handle assembly 160 and includes a thrust bar 200, a first distal slide member 220, a second distal slide member 240, a first proximal slide member 260, and a second proximal slide member 280. Thrust bar 200 is disposed at least partially within elongate member 120 (see FIG. 1) and has a proximal portion 202, a distal portion 204, a first lateral side 206, and a second lateral side 208 (see FIG. 4). Knife assembly 190 is configured to engage distal portion 204 of thrust bar 200. In addition, thrust bar 200 is configured to move along with knife assembly 190 between proximal and distal positions with respect to handle assembly 160 upon actuation of handle assembly 160, for instance.

[0034] First distal slide member 220 has proximal and distal portions 222, 224, respectively, and is positioned adjacent first lateral side 206 of thrust bar 200. Distal portion 224 of first distal slide member 220 is fixed adjacent distal portion 204 of thrust bar 200 such as by example on or more spot welds. This attachment can be made using adhesives, molding, welding, spot-welding or other methods. Proximal portion 222 of first distal slide member 220 is adapted to slide relative to thrust bar 200 when a portion of thrust bar 200 moves in a curvilinear direction (e.g., through an articulated joint, around a curved jaw member, etc.), as seen in FIG. 6. Proximal portion 202 of thrust bar 200 extends proximally beyond a proximal-most end 226 of first slide member 220.

[0035] Second distal slide member 240 has proximal and distal portions 242, 244 and is positioned adjacent second lateral side 208 of thrust bar 200. Distal portion 244 of second distal slide member 240 is fixed adjacent distal portion 204 of thrust bar 200. Proximal portion 242 of second distal slide member 240 is adapted to slide relative to thrust bar 200 when a portion of thrust bar 200 moves in a curvilinear direction, as shown in FIG. 6. Proximal portion 202 of thrust bar 200 extends proximally beyond a proximal-most end 246 of second distal slide member 240.

[0036] First proximal slide member 260 has proximal portion 262 and distal portion 264. Distal portion 264 of first proximal slide member 260 is rigidly affixed to proximal portion 202 of thrust bar 200 and adjacent first lateral side 206 of thrust bar 200. A distal-most end 268 of first proximal slide member 260 is positioned distally of proximal-most end 210 of thrust bar 200 and rigidly attached to thrust bar 200. The attachment can be made using adhesive, molding, welding, spot-welding and other methods. Proximal portion 262 of first proximal slide member 260 is not affixed to proximal-most end 210 of thrust bar 200.

[0037] Second proximal slide member 280 has proximal portion 282 and distal portion 284. Distal portion 284 of second proximal slide member 280 is rigidly affixed to proximal portion 202 of thrust bar 200 and adjacent second lateral side 208 of thrust bar 200. This attachment can be made using adhesives, molding, welding, spot-welding or other methods. A distal-most end 288 of second proximal slide member 280 is positioned distally of proximal-most end 210 of thrust bar 200. Proximal portion 282 of second slide member 280 is not attached to proximal-most end 210 of thrust bar 200. Referring to FIGS. 5 and 6, a user employs surgical instrument 100 to join and/or cut tissue during operation. Initially, the user locates the target tissue and places said target tissue between first and second jaw members 130, 140. To place the target tissue between first and second jaw members 130, 140, the user might need to articulate end effector 154 with respect to longitudinal axis A-A by moving articulation knob 166 in the desired direction. In such case, end effector 154 defines an oblique angle relative to longitudinal axis A-A. Also, the user can bend elongate portion 120 relative to longitudinal axis A-A to reach the target tissue with end effector 154. In any case, at least a portion of actuation assembly 180 is capable of bending to mirror the path of the elongate portion 120 and end effector 124.

[0038] Once the target tissue has been positioned between first and second jaw members 130, 140, the users pivots movable handle 164 toward stationary handle 162 or slides clamp bar in a distal direction to drive actuation assembly 180 distally and to move first and second jaw members 130, 140 from a spaced position to an approximated position. In the approximated position, first and second jaw members 130, 140 capture the target tissue therebetween.

[0039] In use, when elongate portion 120 has not been bent, end effector 154 has not been articulated, and jaw members 130, 140 are in-line with longitudinal axis “A-A,” then actuation assembly 180 moves distally and none of the slide members 220, 240, 260, 280 slide relative to thrust bar 280. That is, slide members 220, 240, 260, 280 move distally along with thrust bar 200 when the elongate portion 120 and end effector 154 are oriented substantially parallel to the longitudinal axis A-A, as seen in FIG. 5.

[0040] In use, when elongate portion 120 has been bent, end effector 154 has been articulated with respect to longitudinal axis “A-A,” or jaw members 130, 140 are curved with respect to longitudinal axis “A-A,” a portion of actuation assembly 180 flexes and follows the path of elongate portion 120 and end effector 154. Specifically, proximal portions 222, 242 of first and second distal slide members 220, 240, respectively, slide relative to thrust bar 200, as thrust bar 200 moves in a curvilinear direction, as shown in FIG. 6. Actuation assembly 180 is confined within elongate portion 120 so as to inhibit first and second distal slide members 220, 240, respectively, from separating from thrust bar 200 while actuation assembly advances in a curvilinear direction. While moving actuation assembly 180 along a curved path, distal portions 224, 244 of first and second distal slide members 220, 240, respectively, remain rigidly attached to distal portion 204 of thrust bar 200 and do not slide relative to thrust bar 200. Further, a portion of proximal slide members 260, 280 remain fixed to proximal portion 202 of thrust bar 200 and do not slide relative to thrust bar 200 when actuation assembly is moving in curvilinear direction. The sliding motion of first and second distal slide members 220, 240 with respect to thrust bar 200 reduces the stress on actuation assembly 180 when actuation assembly moves in a curvilinear direction. That is, less force is required to advance actuation assembly 180 in a curvilinear direction. Regardless of whether actuation assembly 180 moves along a curved path or a straight line, actuation assembly 180 drives knife assembly 190 distally upon actuation of handle assembly 160. As knife assembly 190 moves distally toward the target tissue, knife 192 moves along knife channel 138 and cuts tissue captured between first and second jaw members 130, 140.

[0041] It will be understood that various modifications may be made to the embodiments of the presently disclosed surgical instruments. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.