Shaft attachment features for circular surgical staplers

Abstract

An apparatus includes a body, a shaft, and a stapling head assembly. The shaft extends distally from the body and includes a coupling feature. The coupling feature includes a thread or at least one barb. The stapling head assembly is configured to cut and staple tissue. The stapling head assembly is positioned at a distal end of the shaft. The stapling head assembly includes a knife member and a body member. The knife member includes a circular cutting edge configured to cut through tissue. The body member is configured to house the knife member. The body member includes a coupling feature configured to mechanically couple with the coupling feature of the shaft. The coupling feature of the body member includes a thread or at least one barb.

Description

BACKGROUND

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

[0002] One example of an instrument that can be used to provide an anastomosis is a circular stapler. Some such staplers can be operable to clamp tissue layers, cut through the clamped tissue layers, and drive staples through the clamped tissue layers to substantially seal the tissue layers together near the severed ends of the tissue layers to join the two severed ends of the anatomical lumen together. Circular staplers are configured to sever tissue and seal tissue substantially simultaneously. For example, a circular stapler can sever excess tissue at an anastomosis site within an annular array of staples to provide a substantially smooth transition between anatomical lumen segments joined at the anastomosis site. Circular staplers can be used in open or endoscopic procedures. In some cases, a portion of the circular stapler is inserted through a naturally occurring orifice of a patient.

[0003] Examples of circular staplers are described in U.S. Patent Nos. 5,205,459, entitled “Surgical Anastomosis Stapling Instrument,” issued April 27, 1993; 5,271,544, entitled “Surgical Anastomosis Stapling Instrument,” issued December 21, 1993; 5,275,322, entitled “Surgical Anastomosis Stapling Instrument,” issued January 4, 1994; 5,285,945, entitled “Surgical Anastomosis Stapling Instrument,” issued February 15, 1994; 5,292,053, entitled “Surgical Anastomosis Stapling Instrument,” issued March 8, 1994; 5,333,773, entitled “Surgical Anastomosis Stapling Instrument,” issued August 2, 1994; 5,350,104, entitled “Surgical Anastomosis Stapling Instrument,” issued September 27, 1994; and 5,533,661, entitled “Surgical Anastomosis Stapling Instrument,” issued July 9, 1996; and U.S. Patent No. 8,910,847, entitled “Low Cost Anvil Assembly for a Circular Stapler,” issued December 16, 2014. The disclosures of each of the above-cited U.S. Patents are incorporated by reference herein.

[0004] Some circular staplers can include a motorized actuation mechanism. Examples of circular staplers having motorized actuation mechanisms are described in U.S. Pub. No. 2015 / 0083772, entitled “Surgical Stapler with Rotary Cam Drive and Return,” published March 26, 2015, now abandoned; U.S. Patent No. 9,936,949, entitled “Surgical Stapling Instrument with Drive Assembly Having Toggle Features,” issued April 10, 2018; U.S. Patent No. 9,907,552, entitled “Control Features for Motorized Surgical Stapling Instrument,” issued March 6, 2018; and U.S. Patent No. 9,713,469, entitled “Surgical Stapler with Rotary Cam Drive,” issued July 25, 2017. The disclosure of each of the above-cited U.S. Patent Publications is incorporated by reference herein.

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

[0006] Although the present specification describes particular features of the technology, it is not to be limited to those features. It is to be understood that in this application, relative terms are used to describe one feature in terms of or relative to another feature, which is then readily transferred to other features without additional language. Other examples and use cases for the technology will be recognized by those of ordinary skill in the art from the following description of certain examples described with reference to the Figures.

[0007] FIG. 1 depicts a perspective view of an exemplary circular stapler;

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

[0009] FIG. 3 depicts an exploded perspective view of the circular stapler of FIG. 1 with portions of the shaft assembly shown apart from one another;

[0010] FIG. 4 depicts a perspective view of the anvil of the circular stapler of FIG. 1

[0011] FIG. 5 depicts a perspective view of the anvil of the circular stapler of FIG. 4 ​another perspective view of the anvil of

[0012] FIG. 6 depicts FIG. 4 an exploded side elevational view of the anvil of

[0013] FIG. 7 depicts FIG. 1 a perspective view of a stapling head assembly coupled with a shaft assembly of the circular stapler of

[0014] FIG. 8 depicts FIG. 7 an exploded perspective view of a stapling head assembly coupled with the shaft assembly of

[0015] FIG. 9 depicts FIG. 8 a perspective view of a body member of the stapling head assembly of

[0016] FIG. 10 depicts FIG. 9 a perspective cross-sectional view of the body member of

[0017] FIG. 11 depicts FIG. 1 a perspective view of an outer shaft of the shaft assembly of

[0018] FIG. 12 depicts FIG. 11 a cross-sectional side view of the outer shaft of

[0019] FIG. 13A shows FIG. 4 a side elevational view of the anvil of FIG. 7 in a first longitudinal position relative to the stapling head assembly of

[0020] FIG. 13B shows FIG. 4 a side elevational view of the anvil of FIG. 7 in a second longitudinal position relative to the stapling head assembly of

[0021] FIG. 14A depicts FIG. 4 a cross-sectional side view of the anvil of FIG. 7 positioned within a first segment of a digestive tract and the stapling head assembly of

[0022] FIG. 14B depicts FIG. 4 a cross-sectional side view of the anvil of FIG. 7 positioned within a first segment of a digestive tract and the stapling head assembly of

[0023] FIG. 14C depictsFIG. 4 The anvil located in the first segment of the digestive tract and FIG. 7 A cross-sectional side view of the suture head assembly located in the second segment of the digestive tract, wherein the anvil retracts toward the suture head assembly, thereby clamping the tissue between the anvil and the suture head assembly;

[0024] FIG. 14D Depicting FIG. 4 The anvil located in the first segment of the digestive tract and FIG. 7 A cross-sectional side view of a suture head assembly located in the second segment of the digestive tract, wherein the suture head assembly is actuated to cut and suture the held tissue.

[0025] FIG. 14E Depicting FIG. 14A A cross-sectional side view of the first and second segments of the digestive tract joined together at the end-to-end anastomosis.

[0026] FIG. 15 A perspective view depicts a first exemplary alternative suture head assembly coupled to a first exemplary alternative shaft assembly, the first exemplary alternative shaft assembly being able to be combined with... FIG. 1 In a circular suture device, the suture head assembly and FIG. 4 Anvil connection;

[0027] FIG. 16 The stitched head assembly and FIG. 15 An exploded perspective view of the distal portion of the shaft assembly, showing a first exemplary alternative body member of the stitched head assembly and FIG. 15 A first exemplary alternative outer shaft of a shaft assembly, wherein the body member and the outer shaft include a first exemplary coupling feature;

[0028] FIG. 17 Depicting along FIG. 15 The line 17-17 was cut off FIG. 15 A cross-sectional side view of the stitched head assembly and shaft assembly, wherein the main body component uses FIG. 16 The connecting feature is connected to the outer shaft;

[0029] FIG. 18 Depicting FIG. 16 A perspective view of the outer shaft of the shaft assembly;

[0030] FIG. 19 Depicting along FIG. 18 The line 19-19 was cut off FIG. 18 A side view of the cross-section of the outer axis;

[0031] FIG. 20 Depicting FIG. 16 A perspective view of the main components of the sutured head assembly;

[0032] FIG. 21 depicts a cross-sectional side view of the body member of FIG. 20 taken along line 21-21 of FIG. 20 ;

[0033] FIG. 22 depicts a perspective view of the outer shaft and body member of FIG. 16 ;

[0034] FIG. 23 depicts a graph of deflection of the arm of a second example alternative body member when loaded;

[0035] FIG. 24 depicts a graph showing the extension of the arm of the body member of FIG. 23 versus load;

[0036] FIG. 25 depicts a perspective view of a second example alternative stapling head assembly coupled with a second example alternative shaft assembly that can be incorporated into the circular stapler of FIG. 1 , wherein the stapling head assembly is coupled with the anvil of FIG. 4 ;

[0037] FIG. 26 depicts an exploded perspective view of a third example alternative body member of a stapling head assembly and a second example alternative outer shaft of the shaft assembly of FIG. 25 , wherein the body member and the outer shaft include a second example alternative coupling feature; and

[0038] FIG. 27 depicts a cross-sectional side view of the stapling head assembly and shaft assembly of FIG. 25 taken along line 27-27 of FIG. 25 , wherein the body member is coupled together with the outer shaft using the coupling feature of FIG. 26 .

[0039] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology can be carried out in a variety of other ways, including those not necessarily depictured. The drawings are intended to illustrate several aspects of the technology, and to provide a conceptual understanding of various embodiments thereof; it being appreciated that the technology is not limited to the precise arrangements shown. DETAILED DESCRIPTION

[0040] The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those of ordinary skill in the art from the following description, which is by way of illustration one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

[0041] The disclosure of the following patents is incorporated by reference: U.S. Pub. No. 2015 / 0083772, entitled “Surgical Stapler with Rotary Cam Drive and Return,” published March 26, 2015, now abandoned; U.S. Patent No. 9,907,552, entitled “Control Features for Motorized Surgical Stapling Instrument,” issued March 6, 2018; U.S. Patent No. 10,478,189, entitled “Method of Applying an Annular Array of Staples to Tissue,” issued November 19, 2019; U.S. Pub. No. 2018 / 0132853, entitled “Circular Stapler with Recessed Deck,” published May 17, 2018; U.S. Pub. No. 2018 / 0132849, entitled “Staple Forming Pocket Configurations for Circular Surgical Stapler Anvil,” published May 17, 2018; U.S. Pub. No. 2018 / 0310938, entitled “Hysteresis Removal Feature in Surgical Stapling Instrument,” published November 1, 2018.

[0042] I. Overview of an Exemplary Circular Stapling Surgical Instrument

[0043] FIGS. 1-2An exemplary surgical circular suture instrument (10) is depicted, which can be used to provide 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 suture head assembly (300), and an anvil (400). The handle assembly (100) includes a housing (110) defining an angled pistol grip (112). In some models, the pistol grip (112) is vertically oriented. In some other models, the pistol grip (112) is omitted. The handle assembly (100) also includes a user feedback feature (114). In some models, a series of hash marks, colored areas, and / or other fixed indicators are positioned adjacent to the user feedback feature (114). Various suitable alternative features and configurations for the handle assembly (100) will be apparent to those skilled in the art in light of the teachings herein.

[0044] The device (10) in this example also includes a battery pack (120). As will be described in more detail below, the battery pack (120) is operable to provide power to a motor (not shown) in the pistol grip (112). The battery pack (120) is removable from the handle assembly (100). Specifically, as FIGS. 1-2 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), a latch (122) of the battery pack (120) resiliently engages an internal feature of the housing (110) to provide a snap-fit ​​engagement. To remove the battery pack (120), an operator can press the latch (122) inward to disengage the latch (122) from the internal feature of the housing (110) and then pull the battery pack (120) proximally from the socket (116). It should be understood that the battery pack (120) and the handle assembly (100) may 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 electrical components in the handle assembly (100) when the battery pack (120) is inserted into the socket (116). It should also be understood that in some models, the battery pack (120) is integrally integrated into the handle assembly (100), so that the battery pack (120) cannot be removed from the handle assembly (100).

[0045] The shaft assembly (200) extends distally from the handle assembly (100) and includes a pre-formed bend. In some embodiments, the pre-formed 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 skilled in the art from the teachings herein. In some other embodiments, the shaft assembly (200) is straight, thus lacking the pre-formed bend. Various exemplary components that may be incorporated into the shaft assembly (200) will be described in more detail below.

[0046] The suture head assembly (300) is located at the distal end of the shaft assembly (200). For example... FIGS. 1-2 As shown and as will be described in more detail below, the anvil (400) is configured to be removably coupled adjacent to the suture head assembly (300) and the shaft assembly (200). Furthermore, as will be described in more detail below, the anvil (400) and the suture head assembly (300) are configured to cooperate in manipulating tissue in three ways, including clamping, cutting, and suturing. A knob (130) at the proximal end of the handle assembly (100) is rotatable relative to the housing (110) to provide precise clamping of tissue between the anvil (400) and the suture head assembly (300). The firing trigger (150) can be actuated to provide cutting and suturing of tissue when the safety trigger (140) of the handle assembly (100) pivots away from the firing trigger (150) of the handle assembly (100).

[0047] II. Exemplary Drive Assembly

[0048] FIG. 3 Various components of a shaft assembly (200) are shown, which connect the parts of the sewn head assembly (300) to the parts of the handle assembly (100). Specifically, and as described above, the shaft assembly (200) includes an outer sheath (210) (also referred to as a housing) extending between the handle assembly (100) and the body member (310). In this example, the outer sheath (210) is rigid and includes a pre-formed curved section as described above.

[0049] The shaft assembly (200) further includes a trocar actuation rod (220) and a trocar actuation band assembly (230). A distal end of the trocar actuation band assembly (230) is fixedly secured to a proximal end of a shaft (332) of a trocar (330). A proximal end of the trocar actuation band assembly (230) is fixedly secured to a distal end of the trocar actuation rod (220). It will be appreciated, therefore, that the trocar (330) will translate longitudinally relative to the outer sheath (210) in response to translation of the trocar actuation band assembly (230) and the trocar actuation rod (220) relative to the outer sheath (210). The trocar actuation band assembly (230) is configured to bend such that the trocar actuation band assembly (230) can progress in a pre-formed curve in the shaft assembly (200) as the trocar actuation band assembly (230) translates longitudinally relative to the outer sheath (210). However, the trocar actuation band assembly (230) has sufficient column strength and tensile strength to transmit distal and proximal forces from the trocar actuation rod (220) to the shaft (332) of the trocar (330). The trocar actuation rod (220) is rigid. A clamp (222) is fixedly secured to the trocar actuation rod (220) and is configured to cooperate with a complementary feature within the handle assembly (100) to prevent rotation of the trocar actuation rod (220) within the handle assembly (100) while still allowing longitudinal translation of the trocar actuation rod (220) within the handle assembly (100). The trocar actuation rod (220) further includes a coarse helical thread (224) and a fine helical thread (226).

[0050] The shaft assembly (200) further includes a suture head assembly driver (240) slidably received within the outer sheath (210). A distal end of the suture head assembly driver (240) is fixed to a proximal end of the staple drive member (350). A proximal end of the suture head assembly driver (240) is fixed to the drive carriage (250) via a pin (242). It will be appreciated, therefore, that the staple drive member (350) will translate longitudinally relative to the outer sheath (210) in response to translation of the suture head assembly driver (240) and the drive carriage (250) relative to the outer sheath (210). The suture head assembly driver (240) is configured to bend such that the suture head assembly driver (240) can progress in a pre-formed curve in the shaft assembly (200) as the suture head assembly driver (240) translates longitudinally relative to the outer sheath (210). However, the suture head assembly driver (240) has sufficient column strength to transmit distal forces from the drive carriage (250) to the staple drive member (350). The drive carriage (250) includes a notch (252).

[0051] Although in the foregoing detailed description of embodiments of the application, specific embodiments were described, these specific embodiments were only used to illustrate various aspects of the application. The skilled person will understand that other embodiments can be used and that not all of the features of the embodiments have to be present in any single embodiment. For example, in some embodiments, the staple driver can be omitted. In some embodiments, the staple driver can be replaced by a suture driver. In some embodiments, the staple driver and the suture driver can be combined into a single driver. In some embodiments, the staple driver and the suture driver can be combined into a single driver that is configured to drive both staples and sutures. In some embodiments, the staple driver and the suture driver can be combined into a single driver that is configured to drive both staples and sutures in a single firing stroke. In some embodiments, the staple driver and the suture driver can be combined into a single driver that is configured to drive both staples and sutures in a single firing stroke. FIG. 3Not shown, but it should be understood that the shaft assembly (200) may also include one or more spacer elements within the outer sheath (210). Such spacer elements may be configured to support the trocar actuation band assembly (230) and / or suture head assembly driver (240) as they translate through the outer sheath (210). For example, such spacer elements prevent the trocar actuation band assembly (230) and / or suture head assembly driver (240) from collapsing as they translate through the outer sheath (210). Various suitable forms of such spacer elements will be apparent to those skilled in the art from the teachings herein.

[0052] like FIG. 3 As shown, the handle assembly (100) includes several components operable to actuate the anvil (400) and the suture head assembly (300). The handle assembly (100) also includes components operable to selectively lock triggers (140, 150) based on the position of the anvil (400) relative to the suture head assembly (300). When the triggers (140, 150) are locked, the trigger (150) is prevented from firing actuation of the suture head assembly (300). Therefore, the trigger (150) can only be operated to initiate actuation of the suture head assembly (300) when the position of the anvil (400) relative to the suture head assembly (300) is within a predetermined range. The components of the handle assembly (100) providing the aforementioned operability will be described in more detail below.

[0053] III. Exemplary Anvil

[0054] In the following discussion of the anvil (400), when the anvil (400) is connected to the component (200) of the instrument (10), the terms "distal" and "proximal" (and their variations) will be used relative to the orientation of the anvil (400). Thus, the proximal features of the anvil (400) will be closer to the operator of the instrument (10); while the distal features of the anvil (400) will be farther from the operator of the instrument (10).

[0055] As in FIGS. 4-6As most clearly seen, the anvil (400) of this example includes a head (420) and a handle (410). The head (410) includes a proximal surface (412) defining a plurality of nail-forming recesses (414). In this example, the nail-forming recesses (414) are arranged in two concentric annular arrays. In some other forms, the nail-forming recesses (414) are arranged in three or more concentric annular arrays. The nail-forming recesses (414) are configured to deform a nail when it is driven into the nail-forming recess (414). For example, as is known in the art, each nail-forming recess (414) can deform a generally “U”-shaped nail into a “B”-shaped shape. FIG. 4 As can be seen most clearly, the proximal surface (412) terminates at the inner edge (416) of the outer boundary of the annular recess (418) that defines the handle (420).

[0056] The handle (420) defines a hole (422) and includes a pair of pivoting latching members (430) positioned in the hole (422). FIG. 4 As most clearly seen, each latching 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 latching member (430) within a bore (422). The latching member (430) is located within the bore (422) such that the proximal end (434) is positioned at the proximal end of a lateral opening (424) formed through the sidewall of the handle (420). Thus, the lateral opening (424) provides a clearance for the proximal end (434) and the latch shelf (436) that deflects radially outward from the longitudinal axis defined by the handle (420). However, the latching member (430) is configured to resiliently bias the proximal end (434) and the latching shelf (436) to pivot radially inward toward the longitudinal axis defined by the shank (420). The latching member (430) thus functions as a retaining clamp. This allows the anvil (400) to be removably secured to the trocar (330) of the suture head assembly (300), as will be described in more detail below. However, it should be understood that the latching shelf (436) is merely optional. Any other suitable component, feature, or technique may be used to removably secure the anvil (400) to the trocar (330).

[0057] As in FIGS. 4-5 As most clearly seen, the handle (420) of this example includes a set of longitudinally extending teeth (426) spaced in an angular array around the handle (420). The proximal end of each tooth (426) includes a corresponding lead edge (428). Multiple longitudinally extending teeth (316) (see...) FIG. 8) are equidistantly spaced in an angular array within the bore (314). As described in greater detail below, the key teeth (426) are configured to engage corresponding key teeth (316) of the body member (310) of the stapling head assembly (300) to consistently provide a predetermined angular alignment between the anvil (400) and the stapling head assembly (300). As also described below, this angular alignment can ensure that the staple-forming pockets (414) of the anvil (400) are always properly angularly aligned with the staple openings (324) of the stapling head assembly (300).

[0058] In some instances, it can be desirable to vary the configuration and arrangement of the staple-forming pockets (414) in the anvil (400). It will be appreciated that reconfiguring and rearranging the staple-forming pockets (414) can result in a reconfiguration and rearrangement of the staples (90) formed by the staple-forming pockets (414). For example, the configuration and arrangement of the staple-forming pockets (414) can affect the structural integrity of the anastomosis (70) secured by the staples (90). Additionally, the configuration and arrangement of the staple-forming pockets (414) can affect the hemostasis achieved at the anastomosis (70) secured by the staples (90). The following descriptions relate to several exemplary variations of the anvil (400), providing different staple-forming pocket configurations and arrangements from the staple-forming pocket (414). Various suitable ways of incorporating the alternative anvils described below into the instrument (10) will be apparent to those of ordinary skill in the art in light of the teachings herein.

[0059] For example, staples formed using the exemplary alternative anvils can have an appearance similar to at least some of the staples shown and described in U.S. Patent 10,092,292, entitled “Staple Forming Features for Surgical Stapling Instrument,” issued October 9, 2018, the disclosure of which is incorporated by reference herein. By way of further example only, the formed staples can have an appearance similar to at least some of the staples shown and described in U.S. Publication 2018 / 0132849, entitled “Staple Forming Pocket Configurations for Circular Surgical Stapler Anvil,” published May 17, 2018, the disclosure of which is incorporated by reference herein.

[0060] In addition to or in lieu of the foregoing, the anvil (400) can be further constructed and operated in accordance with at least some of the teachings of 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 by reference herein. Other suitable configurations will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0061] IV. Exemplary Stapling Head Assembly

[0062] A. Overview

[0063] As best seen in FIGS. 7-8 The stapling 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 driving member (350). The body member (310) includes a distally extending cylindrical inner core member (312). The body member (310) is fixedly secured to the outer sheath (210) of the shaft assembly (200). Thus, the body member (310) and the outer sheath (210) together act as the mechanical ground for the stapling head assembly (300).

[0064] As FIG. 8As shown in FIGS. 1 and 2, the anvil 400 includes a body member 410 that defines a plurality of staple cavities 412 that are arranged in a circular pattern about a central longitudinal axis of the anvil 400. The body member 410 further defines a plurality of staple forming pockets 414 that are arranged in a circular pattern about the central longitudinal axis of the anvil 400. The staple forming pockets 414 are arranged in a circular pattern concentric with the circular pattern of the staple cavities 412. The staple cavities 412 and the staple forming pockets 414 are arranged in a circular pattern that is concentric with the circular pattern of the staple cavities 412. The anvil 400 further includes a handle member 420 that is coupled to the body member 410. The handle member 420 includes a plurality of key teeth 426 that are arranged in a circular pattern about the central longitudinal axis of the anvil 400. The key teeth 426 are arranged in a circular pattern that is concentric with the circular pattern of the staple cavities 412 and the staple forming pockets 414. The key teeth 426 are configured to mate with a corresponding plurality of key teeth 316 that are arranged in a circular pattern about the central longitudinal axis of the staple head assembly 300. The key teeth 316 are arranged in a circular pattern that is concentric with the circular pattern of the staple cavities 324 and the staple forming pockets 324. The key teeth 316, 426 are configured to mate with one another to ensure that the staples that are ejected through the staple openings 324 are consistently and accurately driven into the corresponding staple forming pockets 414 regardless of the angular orientation of the anvil 400 relative to the staple head assembly 300 when the anvil 400 is initially secured to the staple head assembly 300.

[0065] A trocar needle (330) is coaxially positioned within an inner core member (312) of the body member (310). As will be described in greater detail below, the trocar needle (330) is operable to translate distally and proximally relative to the body member (310) in response to rotation of the knob (130) relative to the housing (110) of the handle assembly (100). The trocar needle (330) includes a shaft (332) and a head (334). The head (334) includes a pointed tip (336) and an inwardly extending proximal surface (338). Thus, the shaft (332) provides a reduced outer diameter immediately adjacent the head (334), with the proximal surface (338) providing a transition between this reduced outer diameter of the shaft (332) and the outer diameter of the head (334). Although the tip (336) is pointed in this example, the tip (336) is not sharp. Thus, the tip (336) will not readily cause trauma to tissue with unintended contact with the tissue. The head (334) and a distal portion of the shaft (332) are configured for insertion into the aperture (422) of the anvil (400). The proximal surface (338) and the latching shelf (436) have complementary locations and configurations such that the latching shelf (436) engages the proximal surface (338) when the handle (420) of the anvil (400) is fully seated on the trocar needle (330). Thus, the anvil (400) is secured to the trocar needle (330) by a snap engagement formed by the latching member (430).

[0066] The staple driving member (350) is operable to be longitudinally actuated within the body member (310) in response to activation of the motor, as will be described in greater detail below. The staple driving member (350) includes two distally presented concentric annular arrays of staple drivers (352). The staple drivers (352) are arranged to correspond with the arrangement of the staple forming pockets (414) described above. Thus, each staple driver (352) is configured to drive a corresponding staple into a corresponding staple forming pocket (414) when the stapling head assembly (300) is actuated. It will be appreciated that the arrangement of staple drivers (352) can be modified similar to the arrangement of staple forming pockets (414) described above. The staple driving member (350) further defines a bore (354) configured to coaxially receive the inner core member (312) of the body member (310). Bolts (356) of the annular arrays protrude distally from a distally presented surface surrounding the bore (354).

[0067] The knife member (340) is coaxially positioned within the staple driving member (350). The knife member (340) includes a distally presented sharp circular cutting edge (342). The knife member (340) is sized so that it defines an outer diameter that is less than a diameter defined by the inner annular array of the staple drivers (352). The knife member (340) defines an opening (344) configured to coaxially receive an inner core member (e.g., the inner core member (312) of the body member (310)). The knife member (340) includes an annular array of openings (346). The annular array of openings (346) formed in the knife member (340) are configured to complement the annular array of studs (356) of the staple driving member (350) so that the knife member (340) is fixedly secured to the staple driving member (350) via the studs (356) and openings (346). By way of example only, the studs (356) can be heat staked to the knife member (340) using techniques known in the art. Other suitable structural relationships between the knife member (340) and the staple driving member (350) will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0068] The platform member (320) is fixedly secured to the body member (310). The platform member (320) includes a distally presented platform surface (322) that defines two concentric annular arrays of staple openings (324). The staple openings (324) are arranged to correspond to the arrangement of staple drivers (352) and staple-forming pockets (414) described above. Thus, each staple opening (324) is configured to provide a path for a corresponding staple driver (352) to drive a corresponding staple through the platform member (320) and into a corresponding staple-forming pocket (414) when the stapling head assembly (300) is actuated. It will also be appreciated that, in some cases, the configuration and arrangement of the staple openings (324) in the platform member (320) can be modified like the arrangement of staple-forming pockets. It will also be appreciated that various structures and techniques can be used to contain the staples within the stapling head assembly (300) prior to actuation of the stapling head assembly (300). Such structures and techniques for containing the staples within the stapling head assembly (300) can prevent the staples from inadvertently falling through the staple openings (324) prior to actuation of the stapling head assembly (300). Various suitable forms that such structures and techniques can take will be apparent to those of ordinary skill in the art in view of the teachings herein. As seen most clearly in FIG. 7 The platform member (320) defines an inner diameter that is only slightly larger than the outer diameter defined by the knife member (340). Thus, the platform member (320) is configured to allow the knife member (340) to be translated distally to a point where the cutting edge (342) is distanced from the platform surface (322).

[0069] B. Coupling Between Shaft Assembly and Stapling Head Assembly

[0070] FIG. 9 It shows FIG. 8 A perspective view of the internal main body component (310) of the sutured head assembly (300). FIG. 10 It shows FIG. 9 A perspective cross-sectional view of the internal main component (310). For example... FIGS. 9-10 As shown, the main body member (312) of the main body member (310) defines a hole (314). A plurality of longitudinally extending key teeth (316) are equidistantly spaced in an angular array within the hole (314). The distal end of the key teeth (316) includes an introduction edge (318) configured to be complementary to the introduction edge (428) of the key teeth (426) on the shank (420) of the anvil (400). The main body member (310) includes a proximal end and a distal end (358, 360). The proximal end (358) includes an annular protrusion (362) for joining the main body member (310) and the outer shaft (210) together using the magnetoforming process described below. The annular protrusion (362) is formed on the outer surface (364) of the main body member (310). The proximal end (358) also includes a tab (366).

[0071] FIG. 11 It shows FIG. 1 A perspective view of the outer shaft (210) of the shaft assembly (200). FIG. 12 It shows FIG. 11 A perspective cross-sectional view of the outer shaft (210). The outer shaft (210) includes a proximal end and a distal end (260, 262). The outer shaft (210) includes an inner surface and an outer surface (264, 266). The inner surface (264) defines a lumen (268). The outer shaft (210) also includes a proximal recessed surface and a distal recessed surface (270, 272). The outer shaft (210) includes an annular protrusion (274) disposed adjacent to the distal end (262). FIG. 11 A sleeve (274) is also shown surrounding at least a portion of the protrusion (274) and the distal recessed surface (272).

[0072] C. Exemplary Anvil Coupling Detection

[0073] In some forms of the instrument (10), it may be desirable to provide an instrument (10) with certain features configured to indicate whether the anvil (400) is properly attached to the cannula (330) of the suture head assembly (300). FIGS. 13A-13B In the example shown, the cannula (330) includes a colored area (333) that is longitudinally positioned at the exposed location of the colored area (333) before the shank (420) is fully positioned on the cannula (330). FIG. 14A) and is covered when the handle (420) is fully seated on the trocar (330) FIG. 13B

[0074] In addition to the foregoing or in lieu of the foregoing, the stapling head assembly (300) can be further constructed and operative in accordance with at least some of the teachings of 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 by reference herein. Other suitable configurations will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0075] D. Exemplary Tissue Gripping Features

[0076] It can be desirable to provide a version of a stapling head assembly (300) that includes features that enhance the grip on tissue during actuation of the stapling head assembly (300), thereby facilitating successful tissue cutting and staple deployment without increasing the risk of damaging patient tissue when the stapling head assembly (300) is slid along the tissue during positioning of the stapling head assembly (300). By way of further example only, one such deck member is shown and described in U.S. Application 16 / 583,690, entitled “Circular Surgical Stapler,” filed September 26, 2019, the disclosure of which is incorporated by reference herein.

[0077] V. Exemplary Clamping and Firing Sequence

[0078] FIGS. 14A-14E An instrument (10) is shown for forming an anastomosis (70) between two tubular anatomical structures (20, 40). By way of example only, the tubular anatomical structures (20, 40) can comprise segments of a patient’s esophagus, segments of a patient’s colon, other segments of a patient’s digestive tract, or any other tubular anatomical structures. As shown in FIG. 14A The anvil (400) is positioned in one tubular anatomical structure (20), and the stapling head assembly (300) is positioned in the other tubular anatomical structure (40). In versions in which the tubular anatomical structures (20, 40) comprise segments of a patient’s colon, the stapling head assembly (300) can be inserted via the patient’s rectum. It will also be appreciated that, FIGS. 14A-14E ​The procedure shown is an open surgical procedure, although it can be performed laparoscopically as an alternative. Based on the teachings herein, the various suitable ways in which the instrument (10) can be used to form an anastomosis (70) in laparoscopic surgery will be apparent to those skilled in the art.

[0079] like FIG. 14A As shown, the anvil (400) is positioned within the tubular anatomical structure (20) such that the handle (420) protrudes from the open, cut end (22) of the tubular anatomical structure (20). In this example, a purse-string suture (30) is positioned around the middle region of the handle (420) to substantially fix the position of the anvil (400) within the tubular anatomical structure (20). In some other variations, the purse-string suture (30) is tightened around the proximal end of the handle (420). In some such variations, the proximal end of the handle (420) may include a notch or other feature to securely capture the purse-string suture (30). Continuing with this example, the suture head assembly (300) is positioned within the tubular anatomical structure (40) such that the cannula (330) protrudes from the open, cut end (42) of the tubular anatomical structure (20). A purse-string suture (50) is positioned around the middle region of the axis (332) to substantially fix the position of the suture head assembly (300) within the tubular anatomical structure (40). The suture head assembly (300) is then pushed distally to ensure that it is fully positioned at the distal end of the tubular anatomical structure (40).

[0080] Next, the anvil (400) is secured to the cannula (330) by inserting the cannula (330) into the hole (422), as follows: FIG. 14B As shown in the diagram. The latching member (430) engages the head (334) of the cannula (330), thereby providing a secure fit between the anvil (400) and the cannula (330). The operator then rotates the knob (130) while keeping the housing (110) stationary via the pistol grip (112). This rotation of the knob (130) causes the cannula (330) and the anvil (400) to retract proximally. FIG. 14CAs shown, this proximal retraction of the cannula (330) and anvil (400) compresses the tissue of the tubular anatomical structure (20, 40) between the surfaces (412, 322) of the anvil (400) and the suture head assembly (300). When this occurs, the operator can observe tactile resistance or feedback via the knob (130) as the knob (130) is turned, where such tactile resistance or feedback indicates that the tissue is being compressed. When the tissue is compressed, the operator can use the user feedback feature (114) to determine whether the gap distance (d) between the opposing surfaces (412, 322) of the anvil (400) and the suture head assembly (300) is appropriate; and make any necessary adjustments via the knob (130).

[0081] Once the operator has properly set the clearance distance (d) via the knob (130), the operator actuates the safety trigger (140) to actuate the firing trigger (150). The operator then actuates the firing trigger (150). This is achieved by... FIG. 14C The distally driven blade member (340) and nail drive member (350) actuate the suture head assembly (300). As the blade member (340) translates distally, the cutting edge (342) of the blade member (340) cuts excess tissue located in the annular recess (418) of the anvil (400) and inside the blade member (340).

[0082] like FIG. 5 As shown, the anvil (400) of this example includes a detachable washer (417) within an annular recess (418). When the knife member (340) is removed from... FIG. 14C The location shown is to FIG. 14D When the indicated position completes its full distal range of motion, the washer (417) is disconnected by the blade member (340). As the blade member (340) reaches the end of its distal movement, the gradually increasing radius of curvature of the second surface region provides an increased mechanical advantage, thus providing a greater force to disconnect the washer (417). Of course, in some configurations, the disconnectable washer (417) can be omitted entirely. In configurations that include the washer (417), it should be understood that the washer (417) can also act as a cutting plate for the blade member (340) to cut the tissue.

[0083] When the nail driving component (350) is from FIG. 14C The location shown is to FIG. 14D As the indicated position is translated distally, the nail driving member (350) drives the nail (90) through the tissue of the tubular anatomical structure (20, 40) and into the nail-forming recess (414) of the anvil (400). The nail-forming recess (414) deforms the driven nail (90) into a "B" shape known in the art; or into a three-dimensional shape. Thus, the shaped nail (90) holds the ends of the tissue together.

[0084] After the operator has actuated the stapling head assembly (300) as shown in FIG. 14D FIG. 6, the operator rotates the knob (130) to drive the anvil (400) distally away from the stapling head assembly (300), thereby increasing the gap distance (d) to facilitate release of the tissue between the surfaces (412, 322). The operator then removes the instrument (10) from the patient, with the anvil (400) still secured to the trocar (330). Referring back to the example of the tubular anatomical structure (20, 40) comprising a segment of the patient’s colon, the instrument (10) can be removed via the patient’s rectum. With the instrument (10) removed, the tubular anatomical structure (20, 40) is secured together at the anastomosis (70) by the two annular arrays of staples (90), as shown in FIG. 14E FIG. 7. The inner diameter of the anastomosis (70) is defined by the severed edges (60) left by the knife member (340).

[0085] VI. Exemplary Coupling of Shaft Assembly to Stapling Head Assembly

[0086] As previously described, the shaft assembly (200) can be coupled with the stapling head assembly (300). In particular, the outer shaft (210) of the shaft assembly (200) can be coupled together with the body member (310) of the stapling head assembly (300) using a magnetic forming process. Magnetic forming, also known as electromagnetic forming (EM forming), is a high velocity cold forming process for electrically conductive metals. For example, the electrically conductive metals can include copper and aluminum. The workpiece is reshaped by a high intensity pulsed magnetic field that induces a current in the workpiece and a corresponding repulsive magnetic field that rapidly repels portions of the workpiece. Thus, the desired portions of the workpiece can be suitably formed without the need for contact with a tool, although in some versions the workpiece can be pressed against a die.

[0087] With respect to the instrument (10), the outer shaft (210) and the body member (310) can be aligned with a sleeve (276) disposed over the annular protrusion (274) of the outer shaft (210) and the annular protrusion (362) of the body member (310). Once the sleeve (276) is aligned, a magnetic forming machine can apply a magnetic field to crimp the sleeve (276) over the annular protrusion (274) of the outer shaft (210) and the annular protrusion (362) of the body member (310). This crimping of the sleeve (276) couples the outer shaft (210) and the body member (310) together. However, the magnetic forming machine can be expensive, bulky, and utilize a significant amount of energy to form the magnetic field to properly crimp the sleeve (276). The amount of energy and location of the magnetic field concentration resulting from the magnetic forming can make it more difficult to produce an acceptable crimp groove in the sleeve (276) to couple the outer shaft (210) and the body member (310) together. Additionally, the fixture can limit the manner in which the outer shaft (210) and the body member (310) are held. Waste can also be produced on the assembly line due to the fixture to form the magnetic field. Additionally, the body member (310) can stick during a pre-load process that occurs prior to the application of the magnetic field of the magnetic forming.

[0088] Accordingly, it can be desirable to form a suitable coupling between the outer shaft (210) and the body member (310) that eliminates the magnetic forming step involving the magnetic forming machine and the associated magnetic field and sleeve (276). Exemplary alternative couplings are described below in connection with FIGS. 15-27 Exemplary versions of such alternative couplings are described. Each exemplary alternative coupling is illustrated in combination with an instrument body (illustrated as a handle assembly (100) in FIGS. 1-3 below in greater detail, the exemplary body member (610, 810) of the stapling head assembly (600, 800) (also referred to as a "housing") can be coupled with the exemplary outer shaft (510, 710) of the shaft assembly (500, 700) using exemplary coupling features (528, 672, 728, 872). The coupling features (528, 672, 728, 872) can provide a higher tensile strength configured to withstand a higher tensile load than the coupling features formed by the magnetic forming process described above. Accordingly, the coupling features (528, 728) of the outer shaft (510, 710) and the coupling features (672, 872) of the body member (610, 810) can eliminate the use of the magnetic forming step described above.

[0089] A. First Exemplary Alternative Coupling

[0090] 1. Overview

[0091] FIGS. 15-22 A first example alternative shaft assembly (500) is shown coupled with a first example alternative stapling head assembly (600). Specifically, FIG. 15 A shaft assembly (500) is shown coupled with a stapling head assembly (600), and previously referenced FIGS. 4-6 A first example alternative anvil (400) is described coupled with a stapling head assembly (600). FIG. 16 A first example alternative outer shaft (510) of a shaft assembly (500) and FIG. 15 An exploded perspective view of a first example alternative body member (610) of a stapling head assembly (600). FIG. 17 A cross-sectional side view of the shaft assembly (500) and stapling head assembly (600) is shown taken along FIG. 15 line 17-17. FIG. 15 line 17-17.

[0092] The outer shaft (510) and body member (610) can be incorporated into a modified version of the instrument (10) that can include a body (shown in FIGS. 1-3 as handle assembly (100)), an anvil (shown as anvil (400)), a shaft (shown as shaft assembly (500)), and a stapling head assembly (600). The outer shaft (510) and body member (610) of this example are configured and operable similar to the outer shaft (210) and body member (310), with differences described below. For example, the outer shaft (510) can be capable of being inserted into the shaft assembly (200) in place of the outer shaft (210). Similarly, the body member (610) can be capable of being inserted into the stapling head assembly (300) in place of the body member (310).

[0093] 2. First Exemplary Alternative Shaft Assembly Including a First Exemplary Alternative Outer Shaft

[0094] As shown in FIGS. 15-17 , the shaft assembly (500) extends between the handle assembly (100) and the stapling head assembly (600). FIGS. 18-19 The outer shaft (510) is shown in more detail. Specifically, FIG. 18 A perspective view of the outer shaft (510) of the shaft assembly (500) is shown, and FIG. 16 A cross-sectional side view of the outer shaft (510) of the shaft assembly (500) is shown taken along FIG. 19 line 19-19. FIG. 18 line 19-19. FIG. 18a cross-sectional side view of the outer shaft (510). The outer shaft (510) includes proximal and distal ends (512, 514). The outer shaft (510) includes inner and outer surfaces (516, 518). The inner surface (516) defines a lumen (520). The outer shaft (510) also includes proximal and distal recessed surfaces (522, 524). The outer shaft (510) is tubular and can include a pre-formed curve (526).

[0095] The outer shaft (510) includes a coupling feature (528). The coupling feature (528) includes at least one barb (530). As shown, the coupling feature (528) of the present example includes a plurality of annular barbs (530) equally spaced from one another in the axial direction. While the barbs (530) are shown as annular and extending completely around the circumference of the inner surface (516), it is also contemplated that the barbs (530) can have a variety of other suitable shapes and sizes. The inner surface (516) of the outer shaft (510) includes the barbs (530) of the outer shaft (510). The outer shaft (510) also includes a tab receiving portion (532) configured to receive a tab (676) to assist in rotational alignment of the outer shaft (510) and the body member (610).

[0096] Similar to the shaft assembly (200), and although not shown in FIGS. 15-17 , the shaft assembly (500) also includes a trocar actuation rod (similar to the trocar actuation rod (220)) and a trocar actuation band assembly (similar to the trocar actuation band assembly (230)), which are shown in FIG. 3 . The distal end of the trocar actuation band assembly (230) can be fixedly secured to the proximal end of the shaft (632) of the trocar (630). The proximal end of the trocar actuation band assembly (230) is fixedly secured to the distal end of the trocar actuation rod (220). The trocar (630) translates longitudinally relative to the outer shaft (210) in response to translation of the trocar actuation band assembly (230) and the trocar actuation rod (220) relative to the outer shaft (210).

[0097] 3. A first example suturing head assembly including a first example alternative body member

[0098] As FIGS. 15-17As shown, the stapling head assembly (600) can be operable to drive at least one annular array of staples (90), similar to the tissue stapling head assembly (300). As shown, the stapling head assembly (600) includes a body member (610), a deck member (620), an anvil coupling feature (shown as a trocar (630)), a knife member (640), a staple driving member (650), and at least one annular array of staples (90). The stapling head assembly (600) defines a longitudinal axis (LA). The stapling head assembly (600) is positioned at the distal end (514) of the outer shaft (510) of the shaft assembly (500). The stapling head assembly (600) is configured to cut and staple tissue, similar to the stapling head assembly (300) as shown and described with reference to FIGS. 1-3. FIGS. 4-6 The anvil (400) is configured to couple with the anvil coupling feature (shown as a trocar (330)). The anvil (400) is configured to deform at least one annular array of staples (90) driven by the staple driving member (650). The staple driving member (650) is operable to drive at least one annular array of staples (90) through tissue.

[0099] Similar to the deck member (320), the deck member (620) is fixedly secured to the body member (610). The deck member (620) includes a distally presented deck surface (622) defining two concentric annular arrays of staple openings (624). The staple openings (624) are arranged to correspond with the arrangement of staple drivers (652) of the staple driving member (650) and staple-forming pockets (414) of the anvil (400) described above. The staple driving member (650) is similar to the staple driving member (350) described in detail above. The deck member (620) is configured to allow the knife member (640) to translate distally to a point where the cutting edge (642) is distanced from the deck surface (622). Similar to the trocar (330), when the trocar (630) is fixed to the handle (420) and the trocar (630) is retracted proximally, the inner diameter of the bore (614) of the inner core member (612) of the body member (610) laterally constrains the latch member (430) to maintain engagement between the latch shelf (436) and the proximal surface (638) of the head (634) of the trocar (630).

[0100] Similar to the knife member (340), the knife member (640) is coaxially positioned within the staple driving member (650). The knife member (640) includes a sharp, circular cutting edge (642) distally presented configured to cut through tissue. The knife member (640) is dimensioned so that it defines an outer diameter that is less than the diameter defined by the inner annular array of the staple driver (652). The knife member (640) also defines an opening (644) configured to coaxially receive the inner core member (612) of the body member (610). The annular array of openings (646) formed in the knife member (640) are configured to complement the annular array of studs (656) of the staple driving member (650) so that the knife member (640) is securely fixed to the staple driving member (650) via the studs (656) and openings (646). The arrangement of studs (656) of the staple driving member (650) and openings (646) of the knife member (640) can be different than the studs (456) of the staple driving member (450) and the openings (446) of the knife member (440) described above. By way of example only, the studs (456, 656) can be heat staked to the knife member (640) using techniques known in the art. Alternatively, the knife member and staple driving member can be coupled together using any one or more of the teachings disclosed in U.S. Patent Application entitled “Knife for Circular Surgical Stapler” [Attorney Reference No. END9262USNP1.0731766] filed on even date herewith.

[0101] The body member (610) is similar to the body member (310) wherein the following FIGS. 20-22 differences are described. FIG. 20 A perspective view of the body member (610) of the stapling head assembly (600) is shown. FIG. 16 A perspective view of the body member (610) of the stapling head assembly (600) is shown. FIG. 21 A perspective view of the body member (610) of the stapling head assembly (600) is shown. FIG. 20 A perspective view of the body member (610) of the stapling head assembly (600) is shown. FIG. 20FIG. 7 is a cross-sectional side view of the body member (610). The body member (610) can house a staple driving member (650) and a knife member (640). A plurality of longitudinally extending key teeth (616) are equidistantly spaced in an angled array within a bore (614). The distal end of the key teeth (616) include an introduction edge (618) configured to complement the introduction edge (428) of the key teeth (426) on the handle (420) of the anvil (400). Similar to the inner core member (312), the inner core member (612) of the body member (610) defines a bore (614) configured to at least partially receive the staple driving member (650) therein. This engagement prevents the anvil (400) from releasing from the trocar (630) during firing of the stapling head assembly (600). Specifically, after securing the handle (420) to the trocar (630), and when the anvil (400) is subsequently retracted proximally relative to the stapling head assembly (600), the introduction edges (428, 618) can cooperatively engage one another to drive the anvil (400) to rotate relative to the trocar (630) to angularly align the clearance between the key teeth (426) of the anvil (400) and the key teeth (616) of the body member (610). Thus, the key teeth (426, 616) are configured to mate with one another to ensure that staples ejected through the staple openings (624) are consistently and accurately driven into corresponding staple-forming pockets (414) regardless of the angular orientation of the anvil (400) relative to the stapling head assembly (600) when the anvil (400) is initially secured to the trocar (630). The key teeth (426, 616) are configured to engage one another to provide a predetermined angular alignment between the anvil (400) and the stapling head assembly (600).

[0102] The body member (610) includes proximal and distal ends (658, 660). The body member (610) includes an inner surface (662) and an outer surface (664). The inner surface (662) defines a lumen (666) that can be concentrically aligned with the bore (614) along the longitudinal axis (LA). As shown, the body member (610) includes a plurality of arms (668) disposed generally adjacent the proximal end (658). The arms (668) can be separated by slots (670) that extend distally such that each arm (668) can be elastically deflected in a radial direction relative to one or more adjacent arms (668) when the body member (610) is engaged with the outer shaft (510) in the manner described below. While six arms (668) separated by six slots (670) are shown, more or fewer arms (668) and / or slots (670) are also contemplated. Each arm (668) can have the same or different shape and / or size. Similarly, each arm (670) can have the same or different shape and / or size. The shaft member (510) and the body member (610) can be formed from a polymeric material. One such suitable polymeric material can have a filler content (ash) of between approximately 38-42%, a tensile strength of approximately 38,000 psi, a tensile modulus of approximately 4,000,000 psi, a flexural modulus of approximately 3, 100,000 psi, a notched Izod (73F) of 1.4 ft-lb / in, and a specific gravity of between approximately 1.3-1.36 g / cm 3

[0103] The body member (610) includes at least one coupling feature (672) that is configured to mechanically couple with the coupling feature (528) of the outer shaft (510). The coupling feature (672) of the present example includes at least one annular barb (674). As shown, the barbs (674) are equally spaced from one another in the axial direction. The barbs (674) of the body member (610) are circumferentially disposed on each of the respective arms (668). While the barbs (674) are shown as generally annular and disposed on the arms (668) in addition to the slots (670), it is also contemplated that the barbs (674) can have a variety of suitable shapes and sizes. As FIG. 17 ​As shown in FIG. 6, the barb (674) of the arm (668) can be in locking engagement with the barb (530) of the outer shaft (510). For example, at least one barb (674) of the body member (610) can be coupled with at least one barb (530) of the outer shaft (510) using a friction push fit. The barb (674) of the body member (610) can comprise a ratcheting barb. The barbs (530, 674) can be coupled together by translating at least one of the outer shaft (510) or the body member (610) relative to the other of the outer shaft (510) or the body member (610). The coupling feature (672) of the body member (610) can form a one-way permanent connection with the coupling feature (528) of the outer shaft (510) such that, once coupled together, the coupling features (528, 672) do not allow the outer shaft (510) and the body member (610) to separate.

[0104] FIG. 22 A perspective view of a body member (610) and an outer shaft (510) is shown. FIG. 16 As shown, the barb (674) is disposed on an outer surface (664) of the body member (610) to suitably couple with the barb (530) disposed on an inner surface (516) of the outer shaft (510). Alternatively, the barb (530) can be disposed on an outer surface (518) of the outer shaft (510), with a corresponding barb (530) of the body member (610) disposed on an inner surface (662) of the body member (610). One or more arms (668) of the body member (610) can be deflected radially inward and then reflect radially outward upon coupling with the barb (530) of the outer shaft (510). In other words, the slot (670) can allow the arm (668) to bend inward. As shown, the proximal end (658) of the body member (610) also includes a tab (676) to rotatably align with the tab receiving portion (532).

[0105] 4. Second Alternative Exemplary Coupling Feature

[0106] FIGS. 23-24 An example distal end of a second example alternative body member (610a) is shown. FIG. 23 An example graph (600a) is depicted showing radial inward deflection of a single arm (668a) of a body member (600a) under an example loading condition. As shown, FIG. 23 As shown in FIG. 6A, the body member (610a) includes an arm (668a). As shown, a coupling feature (672a) is disposed on the arm (668a). The coupling feature (672a) includes a ring-shaped barb (674a). The body member (610a) is similar to the body member (610) and can be formed of a polymeric material. For example, the polymeric material of the body member (610a) can have a tensile strength of approximately 120 lbs.

[0107] FIG. 24 A plot of load (measured in lbf) versus radial deflection (labeled "Extension") for the arm (668a) of the FIG. 23 As shown by plot (600b), the body member (610a) can be configured to separate from an outer shaft (e.g., outer shaft (510)) when an axial separation load greater than or equal to about 225 lbs is applied. For example, the tensile strength of the polymer material of the body member (610) can be about 38,000 psi. The tensile strength of the polymer material of the body member (610a) can be about 52 MPa, which is equal to about 7,541 psi. An exemplary tensile strength ratio of the body member (610) relative to the body member (610a) can be about 5.04 (38,000 psi / 7,541 psi). The separation load to separate the outer shaft (510) from the body member (610) can be about 1134 pounds (225 lbs x 5.04).

[0108] B. First Exemplary Alternative Coupling

[0109] 1. Overview

[0110] FIGS. 25-27 A second exemplary alternative shaft assembly (700) is shown coupled with a second exemplary alternative stapling head assembly (800). Specifically, FIG. 25 A shaft assembly (700) is shown coupled with a stapling head assembly (800), and a first exemplary alternative anvil (400) is shown coupled with the stapling head assembly (800) as previously described with reference to FIGS. 1-6. FIGS. 4-6 A shaft assembly (700) is shown coupled with a stapling head assembly (800), and a first exemplary alternative anvil (400) is shown coupled with the stapling head assembly (800) as previously described with reference to FIGS. 1-6. FIG. 26 An exploded perspective view of a second exemplary alternative body member (810) of the stapling head assembly (800) of FIG. 25 A cross-sectional side view of the stapling head assembly (800) and the shaft assembly (700) of FIG. 27 A cross-sectional side view of the stapling head assembly (800) and the shaft assembly (700) of FIG. 25 A cross-sectional side view of the stapling head assembly (800) and the shaft assembly (700) of FIG. 25 A cross-sectional side view of the stapling head assembly (800) and the shaft assembly (700) of FIG. 26 A cross-sectional side view of the stapling head assembly (800) and the shaft assembly (700) of

[0111] Similar to the outer shaft (510) and the body member (610), the outer shaft (710) and the body member (810) can be incorporated into modified versions of the instrument (10), which can include a body (in FIGS. 1-3The diagram shows a handle assembly (100), an anvil (400), a shaft (700), and a suture head assembly (800). In this example, the outer shaft (710) and body member (810) are configured and can operate similarly to the outer shaft (210) and body member (310), with differences described below. For example, the outer shaft (710) may be able to be inserted into the shaft assembly (200) instead of the outer shaft (210). Similarly, the body member (810) may be able to be inserted into the suture head assembly (300) instead of the body member (310).

[0112] 2. First Exemplary Alternative Shaft Assembly Including a First Exemplary Alternative Outer Shaft

[0113] like FIGS. 25-27 As shown, a shaft assembly (700) extends between a shank assembly (100) and a stitch head assembly (800). The stitch head assembly (800) is positioned at the distal end (714) of the outer shaft (710). The outer shaft (710) includes a proximal end and a distal end (712, 714). The outer shaft (710) includes an inner surface and an outer surface (716, 718). The inner surface (716) defines a lumen (720). The outer shaft (710) also includes a proximal recessed surface and a distal recessed surface (722, 724). The outer shaft (710) is tubular and may include a pre-formed bend (726).

[0114] The outer shaft (710) includes a connecting feature (728). The connecting feature (728) includes a thread (730). Although the thread (730) is shown as a helical thread and completely surrounds the circumference of the inner surface (716), it is also contemplated that the thread (730) may vary. The inner surface (716) of the outer shaft (710) includes the thread (730) of the outer shaft (710). The outer shaft (710) also includes a tab receiving portion (732) configured to receive tabs (876) to assist in the rotational alignment of the outer shaft (710) and the body member (810). Similar to the shaft assembly (200), the shaft assembly (700) also includes a needle actuating rod (similar to a needle actuating rod (220)) and a needle actuating band assembly (similar to a needle actuating band assembly (230)), which in FIG. 3 As shown in the image.

[0115] 3. A first exemplary stitched head assembly including a first exemplary alternative body component.

[0116] like FIGS. 25-27As shown, the stapling head assembly (800) can be operable to drive at least one annular array of staples (90), similar to the tissue of the stapling head assembly (300). As shown, the stapling head assembly (800) includes a body member (810), a deck member (820), an anvil coupling feature (shown as a trocar (830)), a knife member (840), a staple drive member (850), and at least one annular array of staples (90). The stapling head assembly (800) defines a longitudinal axis (LA). The stapling head assembly (800) can be coupled with the anvil (400), as shown and described with reference to FIGS. 4-6

[0117] Similar to the deck member (320), the deck member (820) is fixedly secured to the body member (810). The deck member (820) includes a distally presented deck surface (822) defining two concentric annular arrays of staple openings (824). The staple openings (824) are arranged to correspond with the arrangement of staple drivers (852) of the staple drive member (850) and the staple-forming pockets (414) of the anvil (400). Similar to the staple drive member (350, 650), the staple drive member (850) is operable to drive at least one annular array of staples (80) through tissue. Similar to the trocar (330, 630), the trocar (830) includes a latching member (430), a latching shelf (436), a proximal surface (838) of a head (834) of the trocar (830).

[0118] Similar to the knife member (340, 640), the knife member (840) includes a distally presented sharp circular cutting edge (842) configured to cut through tissue. The knife member (840) defines an opening (844) configured to coaxially receive the inner core member (812) of the body member (810). An annular array of openings (846) formed in the knife member (840) are configured to complement the annular array of bolts (856) of the staple drive member (850) such that the knife member (840) is fixedly secured to the staple drive member (850) via the bolts (856) and the openings (846).

[0119] ​Similar to the inner core member (612), the inner core member (812) of the body member (810) defines a hole (814) configured to receive at least partially a nail drive member (850) therein. A plurality of longitudinally extending key teeth (816) are equidistantly spaced in an angular array within the hole (814). The distal ends of the key teeth (816) include an introduction edge (818) configured to complement the introduction edge (428) of a key tooth (426) on the shank (420) of the anvil (400). The body member (810) can accommodate both the nail drive member (850) and the blade member (840). The body member (810) includes proximal and distal ends (858, 860). The body member (810) includes an inner surface (862) and an outer surface (864). An inner surface (862) defines a cavity (866) which is concentrically aligned with a hole (614) along a longitudinal axis (LA). Unlike the body member (610), which includes an arm (668) and a slot (670), the body member (810) is not shown as including an arm or a slot. Similar to the outer shaft (510) and the body member (610), the outer shaft (510) and the body member (810) may be formed of a polymer material.

[0120] The main component (810) includes at least one connecting feature (872) configured to mechanically engage with a connecting feature (728) of the outer shaft (710). The connecting feature (872) includes a thread (874) formed by a plurality of individually spaced threads. Although the thread (874) is shown as a helical thread extending along the entire circumference, variations in the thread (874) are possible. FIG. 27 As shown, when properly connected, the thread (874) can rotatably engage with the thread (730) of the outer shaft (710). The threads (730, 874) can be connected together by rotating at least one of the outer shaft (710) or the body member (810) relative to the other of the outer shaft (710) or the body member (810). The connecting feature (872) of the body member (810) can form a removable connection with the connecting feature (728) of the outer shaft (710) such that, once connected, the connecting features (728, 872) allow the outer shaft (710) and the body member (810) to separate. As shown, the thread (874) is provided on the outer surface (864) of the body member (810) to be properly engaged with the thread (730) provided on the inner surface (716) of the outer shaft (710). Alternatively, this arrangement can be reversed so that the thread (730) can be provided on the outer surface (718) of the outer shaft (710), wherein the corresponding thread (730) of the main body (810) is provided on the inner surface (862) of the main body (810).

[0121] C. Exemplary Coupling Method

[0122] A method of manufacturing the instrument (10) by coupling the shaft assembly (500, 700) with the stapling head assembly (600, 800) is also described. The method can include coaxially aligning a proximal end (658, 858) of the body member (610, 810) with a distal end (514, 714) of the outer shaft (510, 710). The method can also include engaging a coupling feature (672, 872) disposed on the proximal end of the body member (610, 810), wherein the coupling feature (528, 728) is disposed on the distal end of the outer shaft (510, 710) to couple the stapling head assembly (600, 800) with the shaft assembly (500, 700) in the absence of a magnetic field.

[0123] As shown, in FIG. 17 and FIG. 22 the coupling step can include engaging at least one barb (530) of the outer shaft (510) with at least one barb (674) of the body member (610) to non-releasably couple the shaft assembly (500) and the stapling head assembly (600) together. Alternatively, the coupling step can include rotatably engaging threads (730) of the outer shaft (710) with threads (874) of the body member (810) to rotatably couple the shaft assembly (700) and the stapling head assembly (800) together. The coupling features (528, 672, 728, 872) (e.g., the barbs (530, 674) and the threads (730, 874)) can eliminate the magnetic forming step. Eliminating the magnetic forming step can eliminate the use of the magnetic field and the sleeve (276). Additionally, using discrete coupling features (528, 672, 728, 872) can allow the coupling between the outer shaft (510, 710) and the body member (610, 810) to be twisted to a desired force, or pushed together to a desired displacement to ensure that a desired connection between the outer shaft (510, 710) and the body member (610, 810) has been achieved. For example, this can include reducing over-torquing or under-torquing of the threads (730) of the outer shaft (710) and the threads (874) of the body member (810).

[0124] VII. Exemplary Combinations

[0125] The following embodiments relate to various non-exhaustive ways in which the teachings herein can be combined or applied. The following embodiments are not intended to limit the scope of any claims that can be presented by subsequent filings, which can utilize the contents of this patent application in whole or in part. The following embodiments are not intended to limit the scope of any claims that can be presented by subsequent filings, which can utilize the contents of this patent application in whole or in part. The following embodiments are provided for illustrative purposes only. Various teachings herein can be arranged and combined in a variety of other ways. It is contemplated that some variations can omit, substitute, or add certain features. Accordingly, although specific implementations have been illustrated and described, any or all the features and / or functions can be combined, some can be left out, and some can be added. Thus, the scope of the application should be determined by the following claims and equivalents thereof.

[0126] EMBODIMENT 1

[0127] An apparatus comprising: (a) a body; (b) a shaft extending distally from the body, wherein the shaft comprises a coupling feature, wherein the coupling feature comprises threads or at least one barb; and (c) a stapling head assembly configured to cut and staple tissue, wherein the stapling head assembly is positioned at a distal end of the shaft, wherein the stapling head assembly comprises: (i) a knife member, wherein the knife member comprises a circular cutting edge configured to cut through tissue, and (ii) a body member configured to house the knife member, wherein the body member comprises a coupling feature configured to mechanically couple with the coupling feature of the shaft, wherein the coupling feature of the body member comprises threads or at least one barb.

[0128] EMBODIMENT 2

[0129] The apparatus of any one or more of embodiments 1-2, wherein the at least one barb of the body member is configured to be translated into engagement with the at least one barb of the shaft with a push fit.

[0130] EMBODIMENT 3

[0131] The apparatus of any one or more of embodiments 1-2, wherein the at least one barb of the shaft comprises a plurality of ratchet barbs, wherein the at least one barb of the body member comprises a plurality of ratchet barbs, wherein at least one of the ratchet barbs of the shaft is in locked engagement with at least one of the ratchet barbs of the body member.

[0132] EMBODIMENT 4

[0133] The apparatus of example 3, wherein the body member comprises an outer surface, wherein the outer surface comprises the ratchet barb of the body member, wherein the shaft comprises an inner surface, wherein the inner surface comprises the ratchet barb of the shaft.

[0134] EMBODIMENT 5

[0135] The apparatus of any one or more of examples 1-4, wherein one of the body member or the shaft comprises at least one arm configured to deflect radially upon coupling with the other of the body member or the shaft.

[0136] EMBODIMENT 6

[0137] The apparatus of any one or more of examples 1, 2, and 5, wherein the body member comprises a plurality of arms, wherein the at least one barb of the body member is circumferentially disposed on each of the arms, wherein the at least one barb of the shaft comprises a plurality of barbs in locking engagement with the at least one barb formed on the arms.

[0138] EMBODIMENT 7

[0139] The apparatus of example 1, wherein the threads of the body member are configured to rotate into engagement with the threads of the shaft.

[0140] EMBODIMENT 8

[0141] The apparatus of any one or more of examples 1 and 7, wherein the threads of the shaft comprise helical threads, wherein the threads of the body member comprise helical threads in locking engagement with the helical threads of the shaft.

[0142] EMBODIMENT 9

[0143] The apparatus of any one or more of examples 1, 7, and 8, wherein the body member comprises an outer surface, wherein the outer surface comprises the helical threads of the body member, wherein the shaft comprises an inner surface, wherein the inner surface comprises the helical threads of the shaft.

[0144] EMBODIMENT 10

[0145] The apparatus of any one or more of embodiments 1-6, wherein one of the shaft or the body member includes a tab, wherein the other of the shaft or the body member includes a receiving portion that receives the tab to ensure the coupling feature of the shaft and the body member and rotatable alignment.

[0146] EMBODIMENT 11

[0147] The apparatus of any one or more of embodiments 1-10, wherein the body member includes an inner core member that defines a bore configured to receive an anvil coupling feature therethrough.

[0148] EMBODIMENT 12

[0149] The apparatus of any one or more of embodiments 1-11, further comprising an anvil having a plurality of key teeth, wherein the body member includes a plurality of key teeth configured to engage the key teeth of the anvil to provide a predetermined angular alignment between the anvil and the stapling head assembly.

[0150] EMBODIMENT 13

[0151] The apparatus of any one or more of embodiments 1-12, wherein the stapling head assembly includes a staple drive member and at least one annular array of staples, wherein the staple drive member is operable to drive the at least one annular array of staples through the tissue.

[0152] EMBODIMENT 14

[0153] The apparatus of embodiment 13, wherein the body member includes a cavity configured to at least partially receive the staple drive member therein.

[0154] EMBODIMENT 15

[0155] The apparatus of any one or more of embodiments 13 and 14, wherein the stapling head assembly includes an anvil coupling feature, wherein the apparatus further comprises an anvil, wherein the anvil is configured to couple with the anvil coupling feature, wherein the anvil is further configured to deform the at least one annular array of staples driven by the staple drive member.

[0156] EMBODIMENT 16

[0157] An apparatus comprising: (a) a body; (b) a shaft extending distally from the body, wherein the shaft comprises a distal end, wherein the distal end comprises a helical thread or at least one barb; and (c) a stapling head assembly positioned at the distal end of the shaft, wherein the stapling head assembly comprises: (i) at least one annular array of staples, (ii) a staple drive member operable to drive the at least one annular array of staples through tissue, (iii) a knife member configured to cut through the tissue, and (iv) a body member configured to house the staple drive member and the knife member, wherein the body member comprises a helical thread or at least one barb, the helical thread or at least one barb of the body member configured to couple with the helical thread or the at least one barb of the distal end of the shaft.

[0158] EMBODIMENT 17

[0159] The apparatus of Example 16, wherein the stapling head assembly comprises an anvil coupling feature, wherein the apparatus further comprises an anvil, wherein the anvil is configured to couple with the anvil coupling feature, wherein the anvil is further configured to deform the at least one annular array of staples driven by the staple drive member.

[0160] EMBODIMENT 18

[0161] A method of manufacturing an apparatus, wherein the apparatus comprises a body, a shaft extending distally from the body, and a stapling head assembly positioned at a distal end of the shaft, wherein the stapling head assembly comprises a body member and a knife member, wherein the knife member comprises a circular cutting edge configured to cut through tissue, the method comprising: (a) coaxially aligning a proximal end of the body member with a distal end of the shaft; and (b) engaging a first coupling feature disposed on the proximal end of the body member with a second coupling feature disposed on the distal end of the shaft to non-releasably couple the stapling head assembly with the shaft in the absence of a magnetic field.

[0162] EMBODIMENT 19

[0163] The method of Example 18, wherein the first coupling feature comprises at least one ratchet barb, wherein the second coupling feature comprises at least one ratchet barb, wherein the engaging step further comprises engaging the at least one ratchet barb of the body member with the at least one ratchet barb of the shaft to couple the shaft and the stapling head assembly together.

[0164] EMBODIMENT 20

[0165] According to the method of embodiment 18, wherein the first coupling feature comprises a helical thread, wherein the second coupling feature comprises a helical thread, wherein the coupling step further comprises engaging the helical thread of the body member with the helical thread of the shaft to couple the shaft and the stapling head assembly together.

[0166] XIII. Miscellaneous

[0167] It is also to be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein can be combined with any one or more of the other teachings, expressions and / or embodiments discussed herein. The above-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable methods, features, objects, etc. described herein can be implemented in any suitable combination depending on the context and / or desires of a particular implementation. Various modifications and changes can be made thereunto without departing from the spirit and scope of the following claims.

[0168] At least some of the teachings herein can also be readily incorporated into one or more teachings of U.S. Pub. No. 2017 / 0258471, entitled “Methods and Systems for Performing Circular Stapling,” published September 14, 2017, the disclosure of which is incorporated by reference herein. U.S. Pub. No. 2015 / 0083772, entitled “Surgical Stapler with Rotary Cam Drive and Return,” published March 26, 2015, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 9,936,949, entitled “Surgical Stapling Instrument with Drive Assembly Having Toggle Features,” issued April 10, 2018, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 9,907,552, entitled “Control Features for Motorized Surgical Stapling Instrument,” issued March 6, 2018, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 9,713,469, entitled “Surgical Stapler with Rotary Cam Drive,” issued July 25, 2017, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 10,226,253, entitled “Firing Assembly for Circular Stapler,” issued March 12, 2019, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 10,478,189, entitled “Method of Applying an Annular Array of Staples to Tissue,” issued November 19, 2019, the disclosure of which is incorporated by reference herein; the teachings herein can be combined in various suitable ways by one of ordinary skill in the art with the teachings of the patents, publications, and patent applications referenced above.

[0169] While examples herein have been provided in the context of circular stapling instruments, it will be appreciated that various teachings herein can be readily applied to various other types of surgical instruments. By way of example only, various teachings herein can be readily applied to linear stapling devices (e.g., an endocutter). As another example only, various teachings herein can be readily applied to motorized electrosurgical devices. For example, various teachings herein can be readily combined with the various teachings of U.S. Patent No. 9,161,803, entitled "Motor Driven Electrosurgical Device with Mechanical and Electrical Feedback," issued October 20, 2015, the disclosure of which is incorporated by reference herein, as will be apparent to those of ordinary skill in the art. Other suitable types of instruments to which the teachings herein can be applied, as well as various ways in which the teachings herein can be applied to such instruments, will be apparent to those of ordinary skill in the art.

[0170] It should be understood that any patents, publications, or other disclosures that are cited herein are incorporated by reference herein to the extent that the same are not inconsistent with the present disclosure. To the extent that the material incorporated by reference is inconsistent with the present disclosure, the present disclosure will control. It should also be understood that, where possible, any of the examples described herein can be performed in a similar manner with the use of alternative components and / or substitutions therefor.

[0171] Versions of the devices described above can have application in conventional medical treatments and procedures conducted by a medical professional, as well as application in robotic-assisted medical treatments and procedures. By way of example only, various teachings herein can be readily incorporated into a robotic surgical system such as the DAVINCI® TM system by Intuitive Surgical, Inc., of Sunnyvale, California.

[0172] The versions described above can be designed to be disposed of after a single use or they can be designed to be used multiple times. Versions may, in either case, be reconditioned for reuse after at least one use. Reconditioning can include an combination of the steps of disassembly of the device, followed by cleaning and / or replacement of particular pieces, and subsequent reassembly. In particular, many versions of the device can be disassembled, and certain subassemblies and / or components of the device can be selectively replaced or removed in any combination. Upon cleaning and / or replacement of particular parts, some versions of the device can be reassembled for subsequent use either at a reconditioning facility, or by a user immediately prior to a procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning / replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

[0173] By way of example only, versions described herein can be sterilized prior to, and / or following, a procedure. In one sterilization technique, the device is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and device can 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 can kill bacteria on the device and in the container. The sterilized device can then be stored in the sterile container for later use. A device can also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam.

[0174] Having shown and described various embodiments of the present application, further adaptations and modifications can be made thereto by one of ordinary skill in the art without departing from the scope of the application. Several of such possible modifications have already been mentioned, and others will be apparent to those skilled in the art. For instance, the example embodiments, implementations, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative only and are not intended to be limiting. Therefore, the scope of the application should be considered in terms of the following claims and any equivalents thereof, and should be understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

Claims

1. An apparatus comprising: (a) a body; (b) a shaft extending distally from the body, wherein the shaft comprises a coupling feature, wherein the coupling feature comprises threads or at least one barb; and (c) a stapling head assembly configured to cut and staple tissue, wherein the stapling head assembly is positioned at a distal end of the shaft, wherein the stapling head assembly comprises: (i) a knife member, wherein the knife member comprises a circular cutting edge configured to cut through tissue, and (ii) a body member configured to house the knife member, wherein the body member comprises a coupling feature configured to mechanically couple with the coupling feature of the shaft, wherein the coupling feature of the body member comprises threads or at least one barb; wherein the body member comprises a plurality of arms, wherein the at least one barb of the body member is circumferentially disposed on each of the arms, wherein the at least one barb of the shaft comprises a plurality of barbs that lockingly engage with the at least one barb formed on the arms.

2. The apparatus of claim 1, wherein, The at least one barb of the body member is configured to be translated into engagement with the at least one barb of the shaft with a push fit.

3. The apparatus of claim 1, wherein, The at least one barb of the shaft comprises a plurality of ratcheting barbs, wherein the at least one barb of the body member comprises a plurality of ratcheting barbs, wherein at least one of the ratcheting barbs of the shaft lockingly engages with at least one of the ratcheting barbs of the body member.

4. The apparatus of claim 3, wherein, The body member comprises an outer surface, wherein the outer surface comprises the ratcheting barbs of the body member, wherein the shaft comprises an inner surface, wherein the inner surface comprises the ratcheting barbs of the shaft.

5. The apparatus of claim 1, wherein, The plurality of arms are configured to deflect radially when coupled with the shaft.

6. The apparatus of claim 1, wherein, One of the shaft or the body member comprises a tab, wherein the other of the shaft or the body member comprises a receiving portion that receives the tab to ensure the coupling features of the shaft and the body member are rotationally aligned.

7. The apparatus of claim 1, wherein, The body member comprises an inner core member that defines a bore configured to receive an anvil coupling feature therethrough.

8. The apparatus of claim 1, further comprising an anvil having a plurality of key teeth, wherein, The body member comprises a plurality of key teeth that are configured to engage the key teeth of the anvil to provide a predetermined angular alignment between the anvil and the stapling head assembly.

9. The apparatus of claim 1, wherein, The stapling head assembly comprises a staple drive member and at least one annular array of staples, wherein the staple drive member is operable to drive the at least one annular array of staples through the tissue.

10. The apparatus of claim 9, wherein, The body member comprises a cavity configured to at least partially receive the staple drive member therein.

11. The apparatus of claim 1, wherein, The shaft comprises a distal end, wherein the distal end comprises at least one barb; and wherein the stapling head assembly further comprises: (iii) at least one annular array of staples, and (iv) a staple driving member operable to drive the staples of the at least one annular array through tissue, wherein the body member is configured to house the staple driving member.

12. The apparatus of claim 11, wherein, The stapling head assembly includes an anvil coupling feature, wherein the apparatus further includes an anvil, wherein the anvil is configured to couple with the anvil coupling feature, wherein the anvil is further configured to deform the staples of the at least one annular array driven by the staple driving member.

13. A method of manufacturing a device, wherein, The apparatus includes a body, a shaft extending distally from the body, and a stapling head assembly positioned at a distal end of the shaft, wherein the stapling head assembly includes a body member and a knife member, wherein the knife member includes a circular cutting edge configured to cut through tissue, the method comprising: (a) coaxially aligning a proximal end of the body member with a distal end of the shaft; and (b) engaging a first coupling feature disposed on the proximal end of the body member with a second coupling feature disposed on the distal end of the shaft to non-releasably couple the stapling head assembly with the shaft in the absence of a magnetic field, wherein the first coupling feature includes at least one first barb and the second coupling feature includes at least one second barb, wherein the body member includes a plurality of arms, wherein the at least one first barb of the body member is disposed circumferentially on each of the arms, wherein the at least one second barb includes a plurality of second barbs, wherein the engaging step further comprises locking engagement of the plurality of second barbs with the at least one first barb.

14. The method of claim 13, wherein, The at least one barb includes at least one first ratcheting barb, wherein the at least one second barb includes at least one second ratcheting barb, wherein the engaging step further comprises engagement of the at least one first ratcheting barb with the at least one second ratcheting barb to couple the shaft and the stapling head assembly together.

Images