Anvil for circular surgical stapler and related manufacturing method using MIM

Abstract

The present invention discloses a method for manufacturing an anvil (10) of a surgical circular stapler (100). The anvil (10) includes a head (12) and a handle (18) extending proximally from the head (12). The method includes forming the head (12) of the surgical circular stapler (100) using a metal injection molding process. The method also includes forming an annular array of nail forming pits (24) in the head (12). The method also includes machining the handle (18) of the surgical circular stapler (100). The method also includes connecting the separately manufactured head (12) and handle (18) of the surgical circular stapler (100) together.

Description

Background Art

[0001] In some surgical procedures (e.g., colorectal, bariatric, thoracic, etc. related surgeries), portions of a patient's digestive tract (e.g., gastrointestinal tract and / or esophagus, etc.) may be cut and removed to remove unwanted tissue or for other reasons. Once the tissue is removed, the remaining portions of the digestive tract may be joined together in an end-to-end, end-to-side, or side-to-side anastomosis. The anastomosis may provide a substantially unobstructed flow path from one portion of the digestive tract to another portion of the digestive tract without causing any type of leakage at the site of the anastomosis.

[0002] An example of an instrument that can be used to provide anastomosis is a circular stapler. Some such staplers can operate to clamp tissue layers, cut through the clamped tissue layers, and drive staples through the clamped tissue layers, so that the tissue layers are basically sealed together near the cut ends of the tissue layers, thereby joining the two cut ends of the anatomical lumen together. The circular stapler is configured to be able to cut off tissue and seal tissue substantially at the same time. For example, the circular stapler can cut off the redundant tissue in the annular array of staples at the anastomosis portion, so as to provide a substantially smooth transition portion between the anatomical lumen segments engaged at the anastomosis portion. The circular stapler can be used in laparotomy or endoscopic surgery. In some cases, a part of the circular stapler is inserted through the naturally occurring orifice of the patient.

[0003] Examples of circular staplers are described in U.S. Pat. No. 5,205,459, entitled "Surgical Anastomosis Stapling Instrument," issued April 27, 1993; U.S. Pat. No. 5,271,544, entitled "Surgical Anastomosis Stapling Instrument," issued December 21, 1993; U.S. Pat. No. 5,275,322, entitled "Surgical Anastomosis Stapling Instrument," issued January 4, 1994; U.S. Pat. No. 5,285,945, entitled "Surgical Anastomosis Stapling Instrument," issued February 15, 1994; U.S. Pat. No. 5,292,053, entitled "Surgical Anastomosis Stapling Instrument," issued March 8, 1994; U.S. Pat. No. 5,292,053, entitled "Surgical Anastomosis Stapling Instrument," issued August 2, 1994; and U.S. Patent No. 5,333,773, entitled “Surgical Anastomosis Stapling Instrument”, issued on September 27, 1994; U.S. Patent No. 5,350,104, entitled “Surgical Anastomosis Stapling Instrument”, issued on July 9, 1996; and U.S. Patent No. 8,910,847, entitled “Low Cost Anvil Assembly for a Circular Stapler”, issued on December 16, 2014. The disclosure of each of the above-cited U.S. patents is incorporated herein by reference.

[0004] Some circular staplers may include an electric actuation mechanism. Examples of circular staplers with electric actuation mechanisms are described in the following patents: U.S. Publication 2015 / 0083772, published on March 26, 2015, entitled "Surgical Stapler with Rotary Cam Drive and Return," now abandoned; U.S. Publication 2015 / 0083773, published on March 26, 2015, entitled "Surgical Stapling Instrument with Drive Assembly Having Toggle Features," now U.S. Patent 9,936,949, published on April 10, 2018; U.S. Publication 2015 / 0083774, published on March 26, 2015, entitled "Control Features for Motorized Surgical Stapling Instrument," now U.S. Patent 9,907,552, published on March 6, 2018; and U.S. Patent 9,907,552, published on March 26, 2015, entitled "Surgical Stapler with Rotary Cam Drive and Return." Drive” and now U.S. Patent 9,713,469, issued on July 25, 2017. The disclosures of each of the above-referenced U.S. patent publications are incorporated herein by reference.

[0005] While various surgical stapling instruments and associated components have been made and used, it is believed that no one prior to the inventor has made or used the invention described in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] While this specification results in claims that particularly point out and distinctly claim such technology, it is believed that such technology will be better understood from certain examples described below in conjunction with the accompanying drawings, wherein like reference numerals indicate the same elements, and wherein:

[0007] Figure 1 shows a perspective view of an exemplary circular stapler;

[0008] Figure 2 Shows Figure 1 A perspective view of a circular stapler with the battery pack removed from the handle assembly and the anvil removed from the stapling head assembly;

[0009] Figure 3 Show Figure 1 A perspective view of an anvil of a circular stapler;

[0010] Figure 4 Shows Figure 3 Another perspective view of the anvil;

[0011] Figure 5 Shows Figure 3 An exploded side elevation view of an anvil;

[0012] Figure 6 Shows Figure 1 A perspective view of a suturing head assembly of a circular stapler;

[0013] Figure 7 Shows Figure 6 A perspective cutaway view of an inner body member of a suture head assembly;

[0014] Figure 8 Shows that it can be combined with Figure 1 A perspective view of a first exemplary alternative anvil of a circular stapler;

[0015] Fig. 9 Shows Figure 8 An exploded perspective view of an anvil of , wherein the anvil includes a handle, a head and a cover;

[0016] Fig.10 Shows Figure 8 An exploded perspective view of a handle and a head of an anvil, wherein the head includes an annular array of staple forming pockets;

[0017] Fig.11 Shows Fig.10 A perspective view of the head of the annular array of nail forming recesses, wherein the annular array of nail forming recesses have not yet been formed;

[0018] Fig.12 Shows Fig.11 Another perspective view of the head;

[0019] Fig.13A shows the nail-forming dimples before being stamped or electrochemically machined;

[0020] Fig. 13B Shows Fig.13A of nail-forming pits, but after being stamped or electrochemically machined;

[0021] Fig.14A Shown along Fig.13A The line 14A-14A is intercepted Fig.13A a central portion of the nail-forming recess;

[0022] Fig. 14B Shown along Fig. 13B The line 14B-14B is intercepted Fig. 13B a central portion of the nail-forming recess;

[0023] Fig.15A Shown along Fig.13A The line 15A-15A is intercepted Fig.13A a portion of a nail-forming recess;

[0024] Fig. 15B Shown along Fig. 13B The line 15B-15B is intercepted Fig. 13B a portion of a nail-forming recess;

[0025] Fig.16 shows the printed or electrochemically processed Fig. 13B An annular array of individual nail-forming recesses;

[0026] Fig.17 Another annular array of individual staple-forming dimples is shown after being embossed or electrochemically machined;

[0027] Fig.18 Shows that it can be combined with Figure 1 An exploded perspective view of a second exemplary alternative anvil of a circular stapler;

[0028] Fig.19 Shows that it can be combined with Figure 1 An exploded perspective view of a third exemplary alternative anvil of a circular stapler of ; and

[0029] Fig. 20 Shows that it can be combined with Figure 1 Circular stapler Figure 8 An exemplary method of manufacturing an anvil.

[0030] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be performed in a variety of other ways, including those not necessarily shown in the drawings. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the technology and, together with the description, serve to explain the principles of the technology; however, it should be understood that the technology is not limited to the precise arrangements shown. DETAILED DESCRIPTION

[0031] The following description of certain examples of the present technology should not be used to limit the scope of the present technology. Other examples, features, aspects, embodiments and advantages of the present technology will become apparent to those skilled in the art from the following description, which is by way of example, one of the best ways contemplated for implementing the present technology. As will be appreciated, the technology described herein can have other different and obvious aspects, all of which do not depart from the present technology. Therefore, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

[0032] It should also be understood that any one or more of the teachings, expressions, implementations, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, implementations, examples, etc. described herein. Therefore, the following teachings, expressions, implementations, examples, etc. should not be considered isolated from each other. With reference to the teachings herein, various suitable ways in which the teachings herein can be combined will be apparent to those of ordinary skill in the art. Such modifications and variations are intended to be included within the scope of the claims.

[0033] For clarity of the disclosure, the terms "proximal" and "distal" are defined herein relative to a human or robotic operator of a surgical instrument. The term "proximal" refers to a position of an element that is closer to a human or robotic operator of a surgical instrument and further away from a surgical end effector of the surgical instrument. The term "distal" refers to a position of an element that is closer to a surgical end effector of a surgical instrument and further away from a human or robotic operator of a surgical instrument. In addition, the terms "first" and "second" are used herein to distinguish one or more parts of a surgical instrument. For example, a first component and a second component may alternatively and respectively be described as a second component and a first component. The terms "first" and "second" and other numerical designations are merely examples of such terms and are not intended to unnecessarily limit the invention described herein.

[0034] I. Overview of Exemplary Circular Stapling Surgical Instruments

[0035] A. Exemplary Circular Stapling Surgical Instrument

[0036] Figure 1 to Figure 2 An exemplary surgical circular stapling instrument (10) is shown, which can be used to provide an end-to-end, side-to-side, or end-to-side anastomosis between two segments of an anatomical lumen (such as a portion of a patient's digestive tract). The instrument (10) of this example includes a handle assembly (100), a shaft assembly (200), a suturing head assembly (300), and an anvil (400). The handle assembly (100) includes a housing (110) that defines a pistol grip (112) oriented obliquely. In some versions, the pistol grip (112) is vertically oriented. In some other versions, the pistol grip (112) is omitted. The handle assembly (100) also includes a user feedback feature (114) that allows observation of a movable indicator needle (not shown), as will be described in more detail below. In some versions, a series of hash marks, colored areas, and / or other fixed indicators are positioned adjacent to user feedback feature (114) to provide visual context for the indicator needle.

[0037] The device (10) includes a battery pack (120). The battery pack (120) is operable to provide power to a motor (160) in the pistol grip (112). Specifically, Figure 1 to Figure 2 As shown, the battery pack (120) can be inserted into a socket (116) defined by the housing (110). Once the battery pack (120) is fully inserted into the socket (116), the latch (122) of the battery pack (120) can resiliently engage the internal features of the housing (110) to provide a snap-fit ​​engagement. It should be understood that the battery pack (120) and the handle assembly (100) can have complementary electrical contacts, pins and sockets, and / or other features that provide a path for electrical communication from the battery pack (120) to the electric components in the handle assembly (100) when the battery pack (120) is inserted into the socket (116). The shaft assembly (200) extends distally from the handle assembly (100) and includes a preformed bend. In some versions, the preformed bend is configured to facilitate positioning of the suture head assembly (300) within the patient's colon. Various suitable bend angles and radii that may be used will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0038] The suturing head assembly (300) is located at the distal end of the shaft assembly (200). Figure 1 to Figure 2 As shown, the anvil (400) is configured to be removably coupled to the shaft assembly (200) adjacent to the suturing head assembly (300). The anvil (400) and the suturing head assembly (300) are configured to cooperate to manipulate tissue in three ways, including clamping tissue, cutting tissue, and suturing tissue. The knob (130) at the proximal end of the handle assembly (100) can be rotated relative to the housing (110) to provide precise clamping of tissue between the anvil (400) and the suturing head assembly (300). When the safety trigger (140) of the handle assembly (100) pivots away from the firing trigger (150) of the handle assembly (100), the firing trigger (150) can be actuated to provide cutting and suturing of tissue.

[0039] A. Exemplary Anvils

[0040] like Figures 3 to 5As shown, the anvil (400) includes a head (410) and a handle (420). The head (410) includes a proximal surface (412) that defines an annular array of nail forming pockets (414). In the present example, the nail forming pockets (414) are arranged in two concentric annular arrays. In some other versions, the nail forming pockets (414) are arranged in three or more concentric annular arrays. The nail forming pockets (414) are configured to deform the nail when the nail is driven into the nail forming pocket (414). For example, as is known in the art, each nail forming pocket (414) can deform a nail that is generally "U" shaped into a "B" shape. As shown in Figure 4 As best seen in FIG. 4 , proximal surface ( 412 ) terminates at an inner edge ( 416 ) that defines the outer boundary of an annular recess ( 418 ) surrounding stem ( 420 ).

[0041] The handle (420) defines a hole (422) and includes a pair of pivoting latch members (430) positioned in the hole (422). Figure 5 As best shown in FIG. 4 , each latch member (430) includes a "T" shaped distal end (432), a rounded proximal end (434), and a latch shelf (436) positioned from the distal to the proximal end (434). The "T" shaped distal end (432) secures the latch member (430) within the hole (422). The latch member (430) is positioned within the hole (422) such that the distal end (434) is positioned at the proximal end of a transverse opening (424) formed through the side wall of the handle (420). The transverse opening (424) thus provides clearance for the distal end (434) and the latch shelf (436) to deflect radially outward from the longitudinal axis defined by the handle (420). However, the latch member (430) is configured to resiliently bias the distal end (434) and the latch shelf (436) to pivot radially inwardly toward the longitudinal axis defined by the handle (420). The latch member (430) thus acts as a retaining fixture. This allows the anvil (400) to be removably fixed to the trocar (330) of the suture head assembly (300), as will be described in more detail below. When the handle (420) is fixed to the trocar (330) and the trocar (330) is retracted toward the proximal side, the inner diameter of the hole (314) in the inner core member (312) of the body member (310) laterally constrains the latch member (430) to maintain the engagement between the latch shelf (436) and the proximal surface (338) of the head (334) of the trocar (330). This engagement prevents anvil (400) from being released from trocar (330) during firing of stapling head assembly (300). However, it should be understood that latch member (436) is merely optional. Any other suitable components, features, or techniques may be used to removably secure anvil (400) to trocar (330). Figure 4As shown, the anvil (400) of this example includes a breakable washer (417) within an annular recess (418). The washer (417) is broken by the knife member (340) when the knife member (340) completes a complete distal range of motion.

[0042] like Figure 3 to Figure 4 As shown, the handle (420) of this example includes a set of longitudinally extending key teeth (426) that are spaced apart in an angled array around the handle (420). The proximal end of each key tooth (426) includes a corresponding lead-in edge (428). As described in more detail below, the key teeth (426) are configured to engage the corresponding key teeth (316) of the inner body member (310) of the suture head assembly (300) so as to consistently provide a predetermined angular alignment between the anvil (400) and the suture head assembly (300). As also described below, this angular alignment ensures that the staple forming recess (414) of the anvil (400) is always properly angularly aligned with the staple opening (324) of the suture head assembly (300). Therefore, in this example, the key teeth (426) are accurately and consistently positioned relative to the staple forming recess (414). In versions where the head (410) and handle (420) are initially formed as separate pieces and subsequently joined together, the machine or other device used to join the head (410) and handle (420) together may have appropriate indexing capabilities to reliably and consistently achieve the proper angular positioning of the head (410) and handle (420) to provide accurate and consistent positioning of the key teeth (426) relative to the nail forming pockets (414). Various suitable ways in which this result may be achieved will be apparent to those of ordinary skill in the art in view of the teachings herein. In some other versions, the head (410) and handle (420) are simultaneously formed together as a single, integral construction.

[0043] C. Exemplary Suturing Head Assembly

[0044] like Figures 7 and 8 As best shown in FIG. 1 , the suture head assembly (300) of the present example is coupled to the distal end of the shaft assembly (200) and includes a body member (310) and a slidable staple drive member (not shown). The body member (310) includes a cylindrical inner core member (312) extending distally. The body member (310) is securely fixed to the outer sheath (210) of the shaft assembly (200). Thus, the body member (310) and the outer sheath (210) together serve as a mechanical ground for the suture head assembly (300).

[0045] like Figure 7As shown, the inner core member (312) of the main body member (310) defines a hole (314). A plurality of longitudinally extending key teeth (316) are equally spaced in an angled array within the hole (314). The distal end of the key teeth (316) includes a lead-in edge (318) that is configured to be complementary to the lead-in edge (428) of the key teeth (426) on the handle (420) of the anvil (400). Specifically, after the handle (420) is secured to the trocar (330), as described in more detail below, and when the anvil (420) is subsequently retracted proximally relative to the stapling head assembly (300), as also described in more detail below, the lead-in edges (318, 428) can cooperatively engage with each other to drive the anvil (400) to rotate relative to the trocar (330), thereby angularly aligning the key teeth (426) of the anvil (400) with the gap between the key teeth (316) of the body member (310). The gap between the key teeth (316) can be configured to have a width that is substantially equal to the width of the key teeth (426). In this way, when the key teeth (426) of the anvil (400) are positioned within the gap between the key teeth (316) of the body member (310), the anvil (400) can achieve a predetermined angular alignment relative to the stapling head assembly (300). This predetermined angular alignment ensures that the staple openings (324) of the platform member (320) are precisely aligned with the corresponding staple forming recesses (414) of the anvil (400). Thus, the key teeth (316, 426) are configured to cooperate with each other to ensure that staples ejected through the staple openings (324) are consistently and accurately driven into the corresponding staple forming recesses (414, 510, 530), regardless of the angular orientation of the anvil (400) relative to the stapling head assembly (300) when the anvil (400) is initially secured to the trocar (330).

[0046] The trocar (330) is coaxially positioned within the inner core member (312) of the main body member (310). The trocar (330) includes a colored area (333). As will be described in more detail below, the trocar (330) is operable to translate distally and proximally relative to the main body member (310) in response to the rotation of the knob (130) relative to the housing (110) of the handle assembly (100). The trocar (330) includes a shaft (332) and a head (334). The head (334) includes a pointed end (336) and a proximal surface (338) extending inwardly. Therefore, the shaft (332) provides a reduced outer diameter adjacent to the head (334), wherein the surface (338) provides a transition between the reduced outer diameter of the shaft (332) and the outer diameter of the head (334). Although the end (336) is pointed in this example, the end (336) is not sharp. The end (336) will not easily cause tissue trauma due to accidental contact with the tissue. The distal portion of the head (334) and the shaft (332) are configured to be inserted into the hole (422) of the anvil (420). The proximal surface (338) and the latch shelf (436) have complementary positions and configurations so that the latch shelf (436) engages the proximal surface (338) when the handle (420) of the anvil (400) is fully placed on the cannula needle (330). Therefore, the anvil (400) is fixed to the cannula needle (330) via the snap-fit ​​engagement formed by the latch member (430). The knife member (340) includes a sharp circular cutting edge (342) presented distally. The knife member (340) also defines an opening configured to coaxially receive the core member (312) of the main body member (310).

[0047] The platform member (320) is securely fixed to the body member (310). The platform member (320) includes a platform surface (322) that is presented distally of two concentric annular arrays of nail openings (324). The nail openings (324) are arranged to correspond to the arrangement of the nail drivers and nail forming recesses (414) described above. Therefore, each nail opening (324) is configured to provide a path for the corresponding nail driver to drive the corresponding nail through the platform member (320) and into the corresponding nail forming recess (414) when the suture head assembly (300) is actuated. It should be understood that the arrangement of the nail openings (322) can be modified similarly to the arrangement of the nail forming recesses (414) described above. It should also be understood that various structures and techniques can be used to accommodate the nails in the suture head assembly (300) before the suture head assembly (300) is actuated. Such structures and techniques for containing staples within stapling head assembly (300) may prevent staples from inadvertently falling through staple openings (324) before stapling head assembly (300) is actuated. Various suitable forms that such structures and techniques may take will be apparent to those of ordinary skill in the art in view of the teachings herein. Figure 7As best shown in , platform member (320) defines an inner diameter that is only slightly larger than the outer diameter defined by knife member (340). Thus, platform member (320) is configured to allow knife member (340) to translate distally to a point where cutting edge (342) is away from platform surface (322).

[0048] II. Exemplary Anvils and Methods of Manufacturing

[0049] As described above, the anvil (400) of the instrument (10) can be machined as a single integral component, or the anvil (400) can be manufactured by initially forming the head (410) and the handle (420) as separate pieces and subsequently joining the head (410) and the handle (420) together. Because the head (410) and the handle (420) can be initially formed as separate pieces, it can be desirable to strengthen the connection between the head (410) and the handle (420). In addition, it can be desirable to use different manufacturing processes and manufacture the head (410) and the handle (420) in a low-cost manner. In addition, it can be desirable to refine certain portions and surfaces of the head (410) and / or the handle (420) to improve the operability of the anvil (400) with the instrument (10). Therefore, it can be desirable to manufacture exemplary anvils (500, 600, 700) that address these and other shortcomings, while also enabling the anvils (500, 600, 700) to be compatible with the anvils described above. Figures 1 to 5 The anvils (400) described act interchangeably.

[0050] If you will refer to Figures 9 to 20 The surgical instrument (10) includes an anvil (500, 600, 700) which is intended to replace the above-referenced Figures 1 to 5 The anvil (400) is described. As previously described, the surgical instrument (10) includes a body (shown as a handle assembly (100)), a shaft assembly (200) extending distally from the handle assembly (100), a suturing head assembly (300), and an anvil (400). The suturing head assembly (300) is positioned at the distal end of the shaft assembly (200). The suturing head assembly (300) includes an anvil coupling feature (shown as a trocar (330)), at least one annular array of nails, and a nail driver. As will be described in more detail below and similar to the function of the anvil (400), the anvils (500, 600, 700) are each configured to be coupled to the trocar (330) and each configured to deform a nail driven by the nail driver.

[0051] A. First Exemplary Alternative Anvil

[0052] Figures 9 to 12 Shows that it can be combined with Figure 1Various perspective views of a first exemplary anvil (500) in an instrument (10) of the present invention. Anvil (500) includes a head (510) and a handle (520). The handle (520) extends proximally from the head (510) and is configured to be coupled to the head (510) once formed. The head (510) includes a Fig.10 The proximal surface (512) of the annular array of staple forming recesses (514) is shown. As shown, the staple forming recesses (514) are arranged similar to Fig.16 Alternatively, the staple forming pockets (514b) may be arranged similar to those shown. Fig.17 Three or more concentric annular arrays of those shown.

[0053] The staple forming pockets (514) are configured to deform the staples as they are driven into the staple forming pockets (514). For example, each staple forming pocket (514) may deform a generally "U" shaped staple into a "B" shaped staple, as is known in the art. Fig.10 and Fig.11 As shown, the proximal surface (512) of the head (510) terminates at an inner edge (516) that defines the outer boundary of an annular recess (518) surrounding the handle (520). Fig.10 In more detail, the head (510) including the nail forming dimples (514) can be formed using an injection molding process such as a metal injection molding process. Metal injection molding (MIM) refers to any metalworking process that mixes finely powdered metal with a binder material to produce a raw material that is then formed and cured using a molding process (such as injection molding). Metal injection molding allows for the molding of large volume and complex parts. Alternatively, the head (510) can be formed from a polymer material using an injection molding process. As will be described with reference to FIG. 13A to FIG. 16 In greater detail, at least a portion of at least one staple forming pocket (514) can be embossed or electrochemically processed to improve one or more characteristics of the staple forming pocket (514).

[0054] The handle (520) includes a longitudinally extending body (521) that defines a hole (522) and may include a pair of pivoting latch members (not shown) positioned in the hole (522), which may be similar in structure and function to the latch members (430) described above with reference to the handle (420) of the anvil (400). The latch members are located within the hole (522) so that the distal ends are positioned at the proximal ends of the transverse openings (524) formed through the sidewalls of the handle (520). The transverse openings (524) provide clearance for the latch members to deflect radially outward from the longitudinal axis defined by the handle (520). The latch members allow the anvil (500) to be removably secured to the trocar (330) of the stapling head assembly (300). When the handle (520) is secured to the trocar (330) and the trocar (330) is retracted proximally, the inner diameter of the hole (314) in the inner core member (312) of the body member (310) laterally constrains the latch member to maintain engagement with the proximal surface (338) of the head (334) of the trocar (330). This engagement prevents the anvil (500) from being released from the trocar (330) during firing of the stapling head assembly (300). The latch member may be omitted such that the anvil (500) is removably secured to the trocar (330) using any other suitable component, feature, or technique.

[0055] like Figures 8 to 10 As shown, the handle (520) includes a set of longitudinally extending key teeth (526) that are spaced apart in an angular array around the handle (520). The proximal end of each key tooth (526) includes a corresponding lead-in edge (528). The key teeth (526) are configured to engage corresponding key teeth (316) of the internal body member (310) of the suturing head assembly (300) to consistently provide a predetermined angular alignment between the anvil (500) and the suturing head assembly (300). This angular alignment ensures that the staple forming recesses (514) of the anvil (500) are always properly angularly aligned with the staple openings (324) of the suturing head assembly (300). Therefore, the key teeth (526) are accurately and consistently positioned relative to the staple forming recesses (514). As shown Fig. 9 As shown, the handle (520) further includes a flange (540) extending radially outward from the distal end (542) of the handle (520). Therefore, the flange (540) has a larger area than the longitudinally extending body (521) of the handle (520). The flange (540) includes opposing proximal and distal surfaces (544, 546). As shown in reference Fig. 20 In more detail, handle (520) may be machined using one or more machining processes.

[0056] like Fig. 9 and Fig.12As shown, the head (510) includes a recessed portion (548) extending proximally from the distal outer surface (550). The recessed portion (548) includes a recessed surface (552) surrounded by an annular wall (554), wherein a hole (556) extends through the recessed surface (552), the recessed surface being configured to receive the longitudinally extending body (521) of the handle (520). As shown, the hole (556) is concentric with both the distal outer surface (550) and the recessed surface (552); however, other positioning of the hole (556) relative to the distal outer surface (550) and the recessed surface (552) are also contemplated. As shown in FIG. Figures 8 to 10 As shown, recess (548) is sized and configured to receive flange (540) of handle (520). Although recess (548) and flange (540) are shown as being circular, it is also contemplated that recess (548) and flange (540) may have various other shapes (e.g., rectangular) that may prevent relative rotation of head (510) and handle (520), if desired.

[0057] The distal outer surface (555) also includes one or more recessed portions (558), two of which are shown, which can be used to secure distal features (such as a cap). The head (510) can also include a tapered portion (560) extending proximally from the distal outer surface (550). The tapered portion (560) is shown as a bevel. Once the head (510) is coupled to the handle (520), the recessed surface (552) of the recessed portion (548) can be in direct contact with the proximal surface (544) of the flange (520). Figure 8 As shown, after the head (510) is coupled to the handle (520), the distal outer surface (550) of the head (510) is generally flush with the distal surface of the flange (540). In other words, the depth of the recessed portion (548) is approximately the same as the thickness of the flange (540). However, the depth of the recessed portion (548) and / or the thickness of the flange (540) may vary. In addition, if desired, the distal outer surface (550) may be curved.

[0058] like Fig. 9As shown, the head (510) can be connected to the handle (520) using a cover (562) (shown as a thin anvil plate). The cover (562) is configured to sandwich the flange (540) of the handle (520) between the cover (562) and the head (510). The cover (562) includes a proximal surface and a distal surface (564, 566). According to one embodiment, the cover (562) may be a material (e.g., a polymer material) that is overmolded onto the head (510) using one or more overmolding processes. More specifically, the cover (562) may be overmolded onto the distal surface (546) of the flange (540) and / or the distal outer surface (550) of the head (510). Therefore, the cover (562) may not be a separate component. Alternatively, the cover (562) may be selectively connected to the head (510) using one or more fixing features that are configured to be connected to the recess (558). As shown, cover (562) is formed from a polymer material; however, cover (562) may be formed from any suitable material.

[0059] The staple forming recess (514) may be formed simultaneously with the head (510) or after the head is formed. Fig.11 and Fig.12 A perspective view of the head (510) is shown, but the staple forming recess (514) has not yet been formed. Fig. 20 In more detail, if desired, at least a portion of head (510) may be machined after forming head (510).

[0060] like FIG. 13A to FIG. 16 As shown, at least a portion of the staple forming recess (514) may be stamped or electrochemically machined after the staple forming recess (514) is formed using an injection molding process (eg, a metal injection molding process). More specifically, Fig.13A The staple forming recess (514a) is shown before being stamped or electrochemically processed, and Fig. 13B Shows the printed or electrochemically processed Fig.13A The nail forming pit (514). Fig.13A As shown, the staple forming pocket (514a) includes a central portion (570a) disposed between outer portions (572a, 574a). Fig. 13B , Fig. 14B and Fig. 15BAs shown, the central portion (570) of the staple forming pocket (514) is subsequently embossed or electrochemically processed, which produces a smoother surface and a more dense surface than another portion (e.g., the outer portions (572, 574)) that has not been embossed or electrochemically processed. As a result, the outer portions (572, 574) have a rougher and less dense surface than the central portion (570) of the staple forming pocket (514). Alternatively, if desired, the entire staple forming pocket (514) including the outer portions (572, 574) can be embossed or electrochemically processed.

[0061] "Imprinting" is a form of precision stamping in which the workpiece is subjected to sufficiently high stresses to induce plastic flow on the surface of the material. Plastic flow reduces the surface grain size and hardens the surface of the workpiece, while the deeper material in the workpiece retains its toughness and ductility. Imprinting also improves the dimensional tolerance of the nail forming pit (514). Electrochemical machining (ECM) is a method of removing metal using one or more electrochemical processes. Electrochemical machining can be used for mass production due to cost effectiveness, and is used to machine extremely hard materials or materials that are difficult to machine using conventional methods. Electrochemical machining can cut small or uniquely shaped angles, complex contours or cavities in hard metal workpieces.

[0062] Fig.14A Shown along Fig.13A The center portion (570a) of the nail forming recess (514a) is intercepted by the line 14A-14A, and Fig. 14B Shown along Fig. 13B The center portion 570 of the nail forming pit (514) is intercepted by the line 14B-14B. As shown in the figure, when comparing Fig.14A and Fig. 14B When the center portion (570a) has been stamped or electrochemically processed, it is smoother and denser than another portion (e.g., the outer portion (572, 574)) of the same nail forming pit (514) that has not been stamped or electrochemically processed.

[0063] Fig.15A Shown is a view taken along line 15A-15A. Fig.13A The nail forming recess (514a) is a part of Fig. 15B Shown is a view taken along line 15B-15B Fig. 13B As shown in the figure, when comparing Fig.15A and Fig. 15B When the channel (576) is created after the embossing or electrochemical machining process. Fig.16 Shown after being stamped or electrochemically processed Fig. 13B The center portion (570) is provided with an annular array of nail-forming recesses (514). More specifically, the center portion (570) is stamped or electrochemically machined.

[0064] Fig.17 Another annular array of staple forming dimples (514b) is shown after being embossed or electrochemically processed. Similar to staple forming dimples (514), staple forming dimples (514b) also include a center portion (570b) and outer portions (572b, 574b). As shown, the center portion (570b) is embossed or electrochemically processed and is therefore smoother and denser than another portion of the same staple forming dimples (514b) that is not embossed or electrochemically processed (e.g., outer portions (572b, 574b)).

[0065] B. Second Exemplary Alternative Anvil

[0066] Fig.18 Shows that it can be combined with Figure 1 A perspective view of a second exemplary anvil (600) in an instrument (10) of the present invention that replaces the anvils (400, 500) described above. Similar to anvil (500), anvil (600) includes a head (610), a handle (620) and a cover (662). As described in more detail below, unlike cover (562), cover (662) includes one or more engagement features. Similar to head (510), head (610) includes a proximal surface (612), a nail forming recess (614), a recessed portion (648), a distal outer surface (650), a recessed surface (652), an annular wall (654), a hole (656), a recessed portion (658) and a tapered portion (660). Similar to handle (520), handle (620) includes a hole (622), a transverse opening (624), a set of longitudinally extending key teeth (626), a lead-in edge (628), a flange (640), and a distal end (642). Similar to flange (540), flange (640) includes opposing proximal and distal surfaces (644, 646). Similar to cap (562), cap (662) includes opposing proximal and distal surfaces (664, 666).

[0067] The proximal surface (612) of the head (610) defines an annular array of staple forming recesses (614) similar to Fig.10 As shown in reference Fig. 20 In more detail, the head (610) including the staple forming recess (614) may be formed using a metal injection molding process and subsequently machined using one or more machining processes. FIG. 13A to FIG. 16As described above, at least a portion of at least one of the nail forming recesses (614) may be stamped or electrochemically processed to improve one or more characteristics of the nail forming recess (614). The recessed portion (648) of the head (610) extends proximally from the distal outer surface (650). The recessed surface (652) is surrounded by an annular wall (654), wherein a hole (656) extends through the recessed surface (652). The hole (656) is configured to receive the longitudinally extending body 621 of the handle (620) therethrough. The size and configuration of the recessed portion (648) are configured to receive the flange (640) of the handle (620). Once the head (610) is coupled to the handle (620), the recessed portion (648) of the head (610) can directly contact the proximal surface (644) of the flange (620). The distal outer surface (655) of the head (610) also includes one or more recesses (658), two of which are shown, which may be used to secure distal features such as a cap (662). A tapered portion (660) extends proximally from the distal outer surface (650).

[0068] like Fig.18 As shown, handle (620) extends proximally from head (610) and is configured to be coupled to head (610) once formed. Figures 8 to 12 As shown in FIG. 6 , the handle ( 620 ) includes an outwardly extending portion ( 630 ). Fig.18 As shown, the flange (640) extends radially outward from the distal end (642) of the handle (620). The flange (640) includes opposing proximal and distal surfaces (644, 646). Fig. 20 In more detail, the handle (620) can be formed using a metal injection molding process and subsequently machined using one or more machining processes. Thus, the head (610) and the handle (620) can each be formed separately using a metal injection molding process. Additionally, the head (610) and the handle (620) can each be machined separately after being formed by the respective metal injection molding processes.

[0069] The head (610) can be coupled to the handle (620) using a cover (662) (shown as an arcuate cover in this exemplary embodiment). The cover (662) is configured to sandwich the flange (640) of the handle (620) between the cover (662) and the head (610). Unlike the cover (562), the cover (662) can be selectively coupled to the head (610) using one or more fixing features. For example, the cover (662) can include at least one proximally facing protrusion (668) that is configured to be coupled to at least one corresponding recess (658). Thus, coupling the cover (662) to the head (610) includes inserting the proximally facing protrusion (668) into the recess (658). Although each recess (662) is shown as extending completely through the distal outer surface (650), it is contemplated that the recess (658) may only partially extend through the distal outer surface (650). While cap (662) is shown as being formed from a polymer material; it is contemplated that cap (662) may be formed from any suitable material. As shown, distal surface (666) of cap (662) is rounded, thereby forming a hemispherical shape.

[0070] C. Third Exemplary Alternative Anvil

[0071] Fig.19 It is shown that the anvil (400, 500) can be replaced by the above-mentioned Figure 1 10 . A perspective view of a third exemplary anvil (700) in an instrument (10) of the present invention. Similar to anvil (500), anvil (700) includes a head (710) and a handle (720). Similar to head (510), head (710) includes a proximal surface (712), a nail forming pit (714), a recessed portion (748), a distal outer surface (750), a recessed surface (752), an annular wall (754), a hole (756) and a tapered portion (760). Similar to handle (520), handle (720) includes a hole (722), a transverse opening (724), a set of longitudinally extending key teeth (726), an introduction edge (728), and a flange (740) and a distal end (742). Similar to flange (540), flange (740) includes opposing proximal and distal surfaces (744, 746).

[0072] The proximal surface (712) of the head (710) defines an annular array of staple forming recesses (714) similar to Fig.10 As shown in reference Fig. 20 In more detail, the head (710) including the staple forming recess (714) may be formed using a metal injection molding process and subsequently machined using one or more machining processes. FIG. 13A to FIG. 16As described above, at least a portion of at least one of the nail forming recesses (714) can be stamped or electrochemically processed to improve one or more characteristics of the nail forming recess (714). The recessed portion (748) of the head (710) extends proximally from the distal outer surface (750). The recessed surface (752) is surrounded by an annular wall (754), wherein a hole (756) extends through the recessed surface (752). The hole (756) is configured to receive the longitudinally extending body (721) of the handle (720) therethrough. The size and configuration of the recessed portion (748) are configured to receive the flange (740) of the handle (720). Once the head (710) is coupled to the handle (720), the recessed surface (752) of the recessed portion (748) can be in direct contact with the proximal surface (744) of the flange (720). The tapered portion (760) extends proximally from the distal outer surface (750).

[0073] like Fig.19 As shown, handle (720) extends proximally from head (710) and is configured to be coupled to head (710) once formed. Figures 8 to 12 As shown in FIG. 1 , the handle (720) includes an outwardly extending portion (730). Fig.19 As shown, the flange (740) extends radially outward from the distal end (742) of the handle (720). The flange (740) includes opposing proximal and distal surfaces (744, 746). The distal surface (746) of the flange (740) includes an inner shallow portion (762) and a circular outer edge portion (764). As shown, the circular outer edge portion (764) includes a distal-most portion (766) as the farthest point of the handle (720). The proximal surface (744) of the flange (740) is coupled to the distal outer surface (750) of the head (710). The handle (720) can be formed using a metal injection molding process and subsequently machined using one or more machining processes.

[0074] D. Exemplary Manufacturing Methods

[0075] Fig. 20 shows that manufacturing can be combined with Figure 1An exemplary method (800) of an anvil (500, 600, 700) in an instrument (10) of the present invention. As previously described, the anvil (500, 600, 700) includes a head (510, 610, 710) and a handle (520, 620, 720) extending proximally from the head (510, 610, 710). At step (802), the method (800) includes using an injection molding machine (812) to form a head (510, 610, 710) including a nail forming recess (514, 614, 714). The nail forming recess (514, 614, 714) can be formed simultaneously with the head (510, 610, 710) or after the head is formed using metal injection molding. For example, the head (510, 610, 710) can be formed using a metal injection molding process and using a metal injection molding machine. At step (804), the method (800) includes machining at least a portion of the head (510, 610, 710). Machining may include stamping or electrochemically machining at least a portion of at least one staple forming pocket (514, 614, 714) using a punch or ECM machine (814). As previously described, the portion of the staple forming pocket (514, 614, 714) that is stamped or electrochemically machined is smoother and denser than another portion that is not stamped or electrochemically machined. Other benefits may also be obtained.

[0076] At step (806), the method (800) includes forming the handle (520, 620, 720) using an injection molding machine (816). The injection molding machine (816) may be the same as or different from the injection molding machine (812). The handle (520, 620, 720) may be formed using a metal injection molding process and using the metal injection molding machine. At step (808), the method (800) includes machining the handle (520, 620, 720) using a lathe (818). If desired, the handle (520, 620, 720) may be machined from a single piece of material without being previously formed using an injection molding process.

[0077] At step (810), the method (800) includes coupling a separately manufactured head (510, 610, 710) to a handle (520, 620, 720). Coupling the handle (520, 620) to the head (510, 610) may include coupling a cover (562, 662) to the head (510, 610) to sandwich a flange (540, 640) of the handle (520, 620) between the cover (562, 662) and the head (510, 610). More specifically, where the cover (662) includes a proximally facing protrusion (668), coupling the cover (662) to the head (610) includes inserting the proximally facing protrusion (668) into a recess (658) of the head (610). It is contemplated that coupling handle (520, 620, 720) to head (510, 610, 710) may include, for example, one or more overmolding, welding, adhesives, and / or mechanical securing features (eg, protrusion (668)).

[0078] One of ordinary skill in the art will appreciate that the staples formed by the anvils (400, 500, 600, 700) will have a three-dimensional profile in which the legs are angularly offset from a plane passing through the crown of the staple; in addition to being generally curved toward each other. By way of example only, staples formed using the anvils (400, 500, 600, 700) may have an appearance similar to at least some of the staples shown and described in the following U.S. publications: U.S. Publication 2014 / 0239037, entitled “Staple Forming Features for Surgical Stapling Instrument,” published on August 28, 2014, now U.S. Patent 10,092,292, published on October 9, 2018, the disclosures of which are incorporated herein by reference. By way of further example only, staples formed using anvils (400, 500, 600, 700) may have an appearance similar to at least some of the staples shown and described in the following U.S. publication: U.S. Publication 2018 / 0132849, entitled “Staple Forming Pocket Configurations for Circular Surgical Stapler Anvil,” published on May 17, 2018, the disclosure of which is incorporated herein by reference. Additional features of the anvil are disclosed in U.S. Publication Nos. 2017 / 0258471, published on September 14, 2017; 2015 / 0083772, published on March 26, 2015, now abandoned; 2015 / 0083774, published on March 26, 2015, now U.S. Patent No. 9,907,552, published on March 6, 2018. U.S. Publication Nos. 2016 / 0374672, published on December 29, 2016; 2018 / 0132853, published on May 17, 2018; 2018 / 0132849, published on May 17, 2018; and U.S. Publication No. 2017 / 04 / 28, entitled “Liquid-Immune Trigger Circuit for Surgical Implants.” and U.S. patent application Ser. No. 15 / 581,546, entitled “Hysteresis Removal Feature in Surgical Stapling Instrument,” published on April 28, 2017, the disclosures of which are incorporated herein by reference.

[0079] In addition to or in lieu of the foregoing, anvils (400, 500, 600, 700) may be further constructed and operated in accordance with at least some of the teachings of the following U.S. Patents: U.S. Patent 5,205,459; U.S. Patent 5,271,544; U.S. Patent 5,275,322; U.S. Patent 5,285,945; U.S. Patent 5,292,053; U.S. Patent 5,333,773; U.S. Patent 5,350,104; U.S. Patent 5,533,661; and / or U.S. Patent 8,910,847, the disclosures of which are incorporated herein by reference. Other suitable configurations will be apparent to one of ordinary skill in the art in view of the teachings herein.

[0080] III. Exemplary Combinations

[0081] The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. The following examples are not intended to limit the coverage of any claims that may be proposed at any time in this patent application or in the subsequent submissions of this patent application. It is not intended to make a disclaimer. The following examples are provided only for illustrative purposes. It is expected that the various teachings herein may be arranged and applied in a variety of other ways. It is also contemplated that some variations may omit certain features mentioned in the following examples. Therefore, any of the aspects or features mentioned below should not be considered decisive, unless otherwise, for example, by the inventor or the successor of the inventor concerned clearly indicates so at a later date. If any claim proposed in this patent application or in the subsequent submissions related to this patent application includes additional features other than those mentioned below, these additional features should not be assumed to be added for any reason related to patentability.

[0082] Example 1

[0083] A method for manufacturing an anvil of a surgical circular stapler, wherein the anvil includes a head and a handle extending proximally from the head, the method comprising: (a) forming the head of the surgical circular stapler using a metal injection molding process; (b) forming an annular array of staple forming recesses in the head; (c) machining the handle of the surgical circular stapler; and (d) connecting the separately manufactured head and handle of the surgical circular stapler together.

[0084] Example 2

[0085] The method according to Example 1 also includes: forming the handle using a metal injection molding process before machining the handle.

[0086] Example 3

[0087] The method according to any one or more of embodiments 1 to 2 further includes: machining at least a portion of the head after forming the head using a metal injection molding process.

[0088] Example 4

[0089] The method according to any one or more of embodiments 1 to 2, wherein forming the head using a metal injection molding process and forming the annular array of nail forming pits in the head are performed simultaneously.

[0090] Example 5

[0091] A method according to any one or more of embodiments 1 to 2, wherein the head is formed using a metal injection molding process before the annular array of nail forming recesses are formed in the head.

[0092] Example 6

[0093] According to the method described in any one or more of embodiments 1 to 5, after forming the nail forming pits of the annular array using a metal injection molding process, the method also includes stamping or electrochemically machining at least a portion of at least one of the nail forming pits of the annular array.

[0094] Example 7

[0095] The method according to Embodiment 6, wherein the embossed or electrochemically processed portion is smoother and denser than another portion that is not embossed or electrochemically processed.

[0096] Example 8

[0097] A method according to any one or more of embodiments 6 to 7, wherein the embossed or electrochemically processed portion is a central portion of at least one of the nail forming pits of the annular array of nail forming pits.

[0098] Example 9

[0099] A method according to any one or more of embodiments 1 to 8, wherein the handle includes a flange extending radially outward from a distal end of the handle.

[0100] Example 10

[0101] A method according to Example 9, wherein forming the head further comprises forming the head to include a distal outer surface and a distal recessed portion disposed proximal to the distal outer surface, wherein the size and structure of the distal recessed portion are configured to receive the flange of the handle.

[0102] Embodiment 11

[0103] A method according to Example 10, wherein the flange includes opposing proximal and distal surfaces, wherein coupling the head to the handle further includes contacting the proximal surface of the flange with the distal recessed portion of the head.

[0104] Example 12

[0105] According to the method described in Example 11, making the proximal surface of the flange contact with the distal recessed portion of the head also includes making the proximal surface of the flange contact with the distal recessed portion of the head so that the distal outer surface of the head is substantially flush with the distal surface of the flange.

[0106] Example 13

[0107] A method according to any one or more of embodiments 9 to 12, wherein the flange includes an inner shallow portion and a rounded outer edge portion, and wherein coupling the head to the handle further includes coupling a proximal surface of the flange to a distal surface of the head.

[0108] Embodiment 14

[0109] A method according to any one or more of embodiments 9 to 13, wherein coupling the head to the handle further comprises coupling a cover to the head to sandwich the flange of the handle between the cover and the head.

[0110] Embodiment 15

[0111] A method according to Example 14, wherein the cover includes at least one proximal-facing protrusion and the head includes at least one corresponding recess, wherein connecting the cover to the head also includes inserting the at least one proximal-facing protrusion into the at least one recess.

[0112] Example 16

[0113] A method for manufacturing an anvil of a surgical circular stapler, wherein the anvil includes a head and a handle extending proximally from the head, wherein the head includes an annular array of nail forming recesses, the method comprising: (a) forming the head including the annular array of nail forming recesses; (b) stamping or electrochemically machining at least a portion of at least one of the annular array of nail forming recesses; (c) machining the handle; and (d) connecting the separately manufactured head to the handle.

[0114] Embodiment 17

[0115] A method according to Example 16, wherein the embossed or electrochemically processed portion is a central portion of the at least one nail forming pit, wherein the central portion, once embossed or electrochemically processed, is smoother and denser than another portion that has not been embossed or electrochemically processed.

[0116] Embodiment 18

[0117] The method as recited in any one or more of Embodiments 16 to 17, further comprising: forming the handle using a metal injection molding process prior to machining the handle.

[0118] Embodiment 19

[0119] A surgical instrument comprises: (a) a body; (b) a shaft extending distally from the body; (c) a suturing head assembly positioned at the distal end of the shaft, wherein the suturing head assembly comprises: (i) an anvil coupling feature, (ii) at least one annular array of nails, and (iii) a nail driver, wherein the nail driver is operable to drive the at least one annular array of nails; and (d) an anvil, wherein the anvil is configured to be coupled to the anvil coupling feature, wherein the anvil is further configured to deform the nail driven by the nail driver, wherein the anvil comprises: (i) a handle and (ii) a head configured to be coupled to the handle, wherein the head comprises an annular array of nail forming recesses, wherein a portion of at least one of the annular array of nail forming recesses has a smoother and denser surface than the remainder of the nail forming recess.

[0120] Embodiment 20

[0121] According to the surgical instrument described in Example 19, the part is a central part inserted between the first outer part and the second outer part, wherein the first outer part and the second outer part have a surface that is rougher and less dense than the central part of the nail forming recess.

[0122] Embodiment 21

[0123] A surgical instrument comprises: (a) a body; (b) a shaft extending distally from the body; (c) a suturing head assembly positioned at the distal end of the shaft, wherein the suturing head assembly comprises: (i) an anvil coupling feature, (ii) at least one annular array of nails, and (iii) a nail driver, wherein the nail driver is operable to drive the at least one annular array of nails; and (d) an anvil, wherein the anvil is configured to be coupled to the anvil coupling feature, wherein the anvil is further configured to deform the nail driven by the nail driver, wherein the anvil comprises: (i) a handle and (ii) a head configured to be coupled to the handle and formed using a metal injection molding process, wherein the head comprises an annular array of nail forming recesses.

[0124] Embodiment 22

[0125] A surgical instrument according to Example 21, wherein the head is machined after being formed using a metal injection molding process.

[0126] Embodiment 23

[0127] A surgical instrument according to any one or more of embodiments 21 to 22, wherein the head and the annular array of nail forming pits are formed simultaneously during a metal injection molding process.

[0128] Embodiment 24

[0129] A surgical instrument according to any one or more of embodiments 21 to 23, wherein a portion of the staple forming recess is embossed or electrochemically processed to produce a smoother and denser surface than the remainder of the staple forming recess.

[0130] Embodiment 25

[0131] A surgical instrument according to embodiment 24, wherein the stamped or electrochemically processed portion is a central portion of at least one of the nail forming pits of the annular array of nail forming pits.

[0132] Embodiment 26

[0133] A surgical instrument according to any one or more of embodiments 21 to 25, wherein the handle is formed using a metal injection molding process, wherein the handle includes a flange extending radially outward from a distal end of the handle.

[0134] Embodiment 27

[0135] A surgical instrument according to Example 26, wherein the head further comprises a distal outer surface and a distal recessed portion disposed proximal to the distal outer surface, wherein the size and configuration of the distal recessed portion are configured to receive the flange of the handle.

[0136] Embodiment 28

[0137] A surgical instrument according to Example 27, wherein the flange includes opposing proximal and distal surfaces, wherein the proximal surface of the flange is configured to contact the distal recessed portion of the head.

[0138] Embodiment 29

[0139] A surgical instrument according to Example 28, wherein the proximal surface of the flange is configured to contact the distal recessed portion of the head so that the distal outer surface of the head is substantially flush with the distal surface of the flange.

[0140] Embodiment 30

[0141] A surgical instrument according to any one or more of embodiments 26 to 28, wherein the flange includes an inner shallow portion and a rounded outer edge portion, wherein the proximal surface of the flange is connected to the distal surface of the head.

[0142] Embodiment 31

[0143] A surgical instrument according to any one or more of embodiments 26 to 29, wherein the cover is fixably coupled to the head so that a flange of the handle is sandwiched between the cover and the head.

[0144] Embodiment 32

[0145] A surgical instrument according to Example 31, wherein the cover includes at least one proximal-facing protrusion, wherein the head includes at least one corresponding recess, wherein the at least one proximal-facing protrusion is configured to be inserted into the at least one recess.

[0146] IV. Miscellaneous

[0147] It should also be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, implementations, examples, etc. described herein. Therefore, the above teachings, expressions, implementations, examples, etc. should not be considered isolated from each other. With reference to the teachings herein, various suitable ways in which the teachings herein may be combined will be apparent to those of ordinary skill in the art. Such modifications and variations are intended to be included within the scope of the claims.

[0148] At least some of the teachings herein may also be readily combined with one or more teachings of U.S. Publication No. 2017 / 0258471, entitled “Methods and Systems for Performing Circular Stapling,” published on September 14, 2017, the disclosure of which is incorporated herein by reference. Other suitable types of instruments to which the teachings herein may be applied, and the various ways in which the teachings herein may be applied to such instruments, will be apparent to those of ordinary skill in the art.

[0149] It should be understood that any patent, patent publication, or other public material, whether in whole or in part, allegedly incorporated herein by reference is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other public materials described in the present disclosure. Therefore, and to the extent necessary, the disclosure explicitly listed herein supersedes any conflicting material incorporated herein by reference. Any material or portion thereof allegedly incorporated herein but conflicting with existing definitions, statements, or other public materials listed herein will be incorporated only to the extent that there is no conflict between the incorporated material and the existing public materials.

[0150] The above-described device versions may be used in conventional medical treatments and surgeries performed by medical professionals, as well as robotic-assisted medical treatments and surgeries. By way of example only, the various teachings herein may be readily incorporated into a robotic surgical system, such as the DAVINCI® by Intuitive Surgical, Inc. (Sunnyvale, California). TM system.

[0151] The patterns described above can be designed to be discarded after a single use, or they can be designed to be able to be used multiple times. In either case or both, these patterns can be repaired to be reused after at least one use. Repair can include any combination of the following steps: disassembling the device, then cleaning or replacing specific parts and subsequently reassembling. Specifically, some patterns of the device can be disassembled, and any number of specific parts or parts of the device can be selectively replaced or removed in any combination. When cleaning and / or replacing specific parts, some patterns of the device can be reassembled at a repair facility or reassembled by the user before surgery is about to be performed for subsequent use. Those skilled in the art will appreciate that the repair of the device can be disassembled, cleaned / replaced, and reassembled using a variety of techniques. The use of such technology and the resulting repair device are all within the scope of the present application.

[0152] By way of example only, the types described herein may be sterilized before and / or after surgery. In one sterilization technique, the device is placed in a closed and sealed container such as a plastic bag or a TYVEK bag. The container and device may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the device and in the container. The sterilized device may then be stored in a sterile container for later use. The device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam.

[0153] Various embodiments of the present invention have been shown and described, and further improvements of the methods and systems described herein may be achieved by appropriate modifications by those of ordinary skill in the art without departing from the scope of the present invention. Several such possible modifications have been mentioned, and other modifications will be apparent to those of skill in the art. For example, the embodiments, embodiments, geometries, materials, dimensions, ratios, steps, etc. discussed above are illustrative and not required. Therefore, the scope of the present invention should be considered in light of the following claims, and should be understood not to be limited to the details of the structure and operation shown and described in the specification and drawings.

Claims

1. A method for manufacturing an anvil of a surgical circular stapler, wherein the anvil comprises a head and a handle extending proximally from the head, the method comprising: (a) forming the head of the anvil of the surgical circular stapler using a metal injection molding process with a raw material including fine powder metal and a binder; (b) forming an annular array of staple forming pockets in the head of the anvil; (c) machining the shank of the anvil; (d) inserting the handle of the anvil through the central hole of the head of the anvil; as well as (e) coupling the head and handle of the anvil of the surgical circular stapler together by overmolding a cover onto the anvil to sandwich a flange of the handle between the cover and the head.

2. The method according to claim 1, further comprising: Prior to machining the handle, the handle is formed using a metal injection molding process.

3. The method according to claim 1, further comprising: At least a portion of the head is machined after the head is formed using the metal injection molding process.

4. The method of claim 1, wherein forming the head using the metal injection molding process and forming the annular array of nail forming recesses in the head are performed simultaneously.

5. The method of claim 1, wherein the head is formed using the metal injection molding process prior to forming the annular array of staple forming pockets in the head.

6. A method according to claim 1, wherein after forming the nail forming pits of the annular array using the metal injection molding process, the method further includes stamping or electrochemically machining at least a portion of at least one of the nail forming pits of the annular array.

7. The method of claim 6, wherein the embossed or electrochemically processed portion is smoother and denser than other portions of the nail forming recess.

8. The method of claim 1 , wherein the handle includes a flange extending radially outward from a distal end of the handle, wherein inserting the handle through the central hole of the head further comprises inserting the handle through the central hole of the head until the flange contacts the head.

9. The method of claim 8, wherein forming the head further comprises forming the head to include a distal outer surface and a distal recessed portion disposed proximal to the distal outer surface, wherein inserting the handle through the central hole of the head until the flange contacts the head further comprises: The handle is inserted through the central aperture of the head until the distal recessed portion contacts the flange of the handle.

10. The method of claim 8, wherein the flange includes an inner shallow portion and a rounded outer edge portion, wherein coupling the head to the handle further comprises coupling a proximal surface of the flange to a distal surface of the head.

11. The method of claim 1 , wherein the cover comprises at least one proximally facing protrusion and the head comprises at least one corresponding recess, wherein coupling the cover to the head further comprises inserting the at least one proximally facing protrusion into the at least one recess.

12. A method of manufacturing an anvil of a surgical circular stapler, wherein the anvil comprises a head and a handle extending proximally from the head, wherein the head comprises an annular array of staple forming pockets, the method comprising: (a) forming a head portion of the anvil, the head portion comprising the annular array of staple forming recesses; (b) stamping or electrochemically machining only a predetermined portion of at least one staple forming recess of the annular array of staple forming recesses to form a surface that is smoother and denser than other portions of the staple forming recess, the other portions being less dense than the predetermined portion; (c) machining the shank of the anvil with the shank separated from the head of the anvil; (d) inserting the handle of the anvil through the central hole of the head of the anvil; as well as (e) Connecting the head and the handle together.

13. A method according to claim 12, wherein the predetermined portion to be embossed or electrochemically processed is a central portion of the at least one nail forming pit, and wherein the central portion, once embossed or electrochemically processed, is smoother and denser than another portion that has not been embossed or electrochemically processed.

14. The method according to claim 12, further comprising: Prior to machining the handle, the handle is formed using a metal injection molding process.

15. A surgical instrument comprising: (a) the subject; (b) a shaft extending distally from the body; (c) a suturing head assembly located at the distal end of the shaft, wherein the suturing head assembly comprises: (i) anvil coupling feature, (ii) at least one annular array of spikes, and (iii) a staple driver, wherein the staple driver is operable to drive the at least one annular array of staples; and (d) An anvil made by the method of any one of claims 1-14, wherein the anvil is configured to couple with the anvil coupling feature, wherein the anvil is further configured to deform the staples driven by the staple driver, wherein the anvil comprises: (i) a handle, and (ii) a head configured to be coupled to the handle, wherein the head comprises an annular array of nail forming recesses, wherein only a predetermined portion of at least one of the annular array of nail forming recesses has a surface that is smoother and denser than the remainder of the nail forming recess, the remainder having a density less than the predetermined portion.

16. The surgical instrument according to claim 15, wherein the predetermined portion is a central portion inserted between a first outer portion and a second outer portion, wherein the first outer portion and the second outer portion have a surface with a lower density than the central portion of the nail forming recess.

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