Atraumatic circular stapling instrument

Abstract

Circular stapling instruments and retractable distal tips for such instruments are provided herein. A circular stapling instrument for joining tissue structures comprises a staple assembly comprising an elongate shaft and a staple assembly on a distal end of the shaft with a substantially flat distal surface and a plurality of staples. The instrument includes a tip member configured for positioning in contact with the distal surface of the staple assembly. The tip member is retractable proximally through the staples to a position proximal of the distal surface. The tip member is designed to provide a more atraumatic leading end for the stapling instrument as it is introduced through the anus and navigated through the bowel of the patient. In addition, the tip member may be removed prior to the stapling operation to properly orient the staple assembly with the anvil during the clamping, dissection and / or stapling of tissue.

Description

ATRAUMATIC CIRCULAR STAPLING INSTRUMENTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 671,878, filed July 16, 2024, the complete disclosure of which is incorporated herein by reference for all purposes.TECHNICAL FIELD

[0002] This description generally relates to endoscopic surgical instruments for dissecting, occluding and / or sealing tissue, and more particularly to endoscopic circular staplers that are particularly useful for joining tubular tissue structures together.BACKGROUND

[0003] In certain types of surgical procedures, the use of surgical staples has become the preferred method of joining tissues and, therefore, specially configured surgical staplers have been developed for different applications. For example, intraluminal or circular staplers have been developed for use in joining two tubular structures together, such as surgical procedures involving the lower colon wherein two separated regions of the lower colon are joined together in an anastomosis after a target area has been resected.

[0004] Circular staplers typically comprise an elongate shaft, which has a proximal actuation mechanism and a distal stapling mechanism mounted on the shaft. The distal stapling mechanism typically includes a stapling cartridge that houses a plurality of staples arranged in a concentric circular array. An annular cutting knife is mounted concentrically with the staples within the cartridge or the end effector of the instrument so that it can move axially relative to the cartridge. A movable trocar shaft or capturing spike extends axially from the center of the instrument to detachably couple the anvil to the stapling mechanism. The anvil is configured to shape the end of the staple as the staple is driven into the anvil. The distance between the distal surface of the staple cartridge and the staple anvil is typically controlled by an adjustment mechanism mounted at the proximal end of the stapler shaft to control the axial movement of the capturing spike.

[0005] When performing a lower colon procedure using a circular stapler, the surgeon typically uses a conventional linear stapler with two rows of staples placed on either side of the affected intestinal lesion to be removed and stapled. The target area is cut at the same time as the adjacent ends are stapled. After removing the affected area, the surgeon typically insertsthe anvil of the circular stapler into the proximal end of the lumen, proximal of the staple line. This is done by inserting the anvil head into an entrance that has been cut into the proximal lumen by the surgeon. Sometimes an anvil can be placed transanally by placing the anvil head at the distal end of the stapler and inserting the instrument through the rectum. The proximal end of the intestine is then tied to the anvil shaft using a purse string suture or other conventional tying device and the proximal and distal ends of the intestine are tightened within the gap by closing the gap between the anvil and the cartridge. The circular stapler is then actuated to join the ends and form a tubular passage by driving and forming multiple annular rows of staples through both ends of the intestine. At the same time as the staples are driven and formed, a concentric circular knife blade is driven through the end of the intestinal tissue to cut the end adjacent to the inner row of staples.

[0006] Circular staplers are designed to deliver staples perpendicular to the bowel after the ends have been stapled or gathered via the linear staple line or purse string suture. To orient the tissue correctly, the mating anvil surface is typically designed to be parallel to the staple surface to properly orient the tissue during clamping. As a result, these devices have been designed with a substantially flat distal face.

[0007] A flat faced instrument is difficult to insert into the anal sphincter because it requires a high force to dilate the sphincter. In addition, this non-gradual dilation of the sphincter could lead to soft tissue trauma for the patient. Moreover, for low anterior resection (LAR) procedures in which the distal rectal stump is very low (e.g., 2 cm from the dentate line), after applying high force to insert the instrument beyond the sphincter, the user must suddenly stop the instrument to not cause trauma to the closed distal stump. This “stick-slip” phenomenon requires a high degree of skill by the user.

[0008] For higher up LAR procedures, in which the distal rectal stump is longer, the user is typically required to navigate down the lumen of the bowel to get the instrument distal face to the stapled / suture bowel end. The sharp edges of conventional circular stapler instruments make navigation challenging because the edges may catch the small pouches or “haustra” in the internal topography of the bowel. These challenges are exacerbated by two variables: (1) the patient cavity insufflation causes the bowel walls to squeeze around the instrument, increasing the amount of contact with the distal edge (see FIG. 1 IB); and (2) users typically desire to use the largest diameter stapler that can comfortably fit into the bowel diameter to achieve the largest internal diameter for the stapling procedure.

[0009] Accordingly, it would be desirable to provide circular stapling instruments that have a more atraumatic distal tip for insertion into the anal sphincter and navigation through the bowel of the patient. It would be particularly desirable to provide such instruments that allow the user to remove this atraumatic distal tip from the surgical site during the procedure to present a substantially flat staple assembly that is parallel with the mating anvil surface to properly orient the tissue during clamping.SUMMARY

[0010] The following presents a simplified summary of the claimed subj ect matter in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview of the claimed subject matter. It is intended to neither identify key or critical elements of the claimed subject matter nor delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts of the claimed subject matter in a simplified form as a prelude to the more detailed description that is presented later.

[0011] Circular stapling instruments and retractable distal tips for such instruments are provided herein. Control systems for the stapling instruments and the retractable tips are also provided. The retractable distal tips are designed to provide a more atraumatic leading end for the stapling instrument as it is introduced through the anus and navigated through the bowel of the patient. The retractable tips may be removed prior to the stapling operation to properly orient the staple assembly with the anvil during the clamping, dissection and / or stapling of tissue.

[0012] In one aspect, a circular stapling instrument comprises an elongate shaft and a staple assembly on a distal end of the shaft. The staple assembly comprises a distal surface with a plurality of staples. The instrument further comprises a tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface. The tip member is retractable proximally through the staples on the staple assembly.

[0013] In embodiments, the tip member is retractable through a central opening disposed within the staples in the distal surface of the staple assembly. In certain embodiments, the tip member is retractable through the shaft of the instrument. This ensures that the tip member does not contact, distend or otherwise damage bowel tissue as it is removed from the surgical site.

[0014] In embodiments, the tip member comprises a proximal end adjacent to, or near, thedistal surface of the staple assembly and a distal end having a smaller diameter than the proximal end. In some embodiments, the tip member tapers towards the distal end to create a gradual transition, which allows the user to splay the anal sphincter with minimal trauma. The tip member may have a shape that creates a substantially pointed or rounded tip, such as a cone, a triangular based pyramid, a square based pyramid or the like. This design more easily expands or splays the bowel tissue, which improves navigation through the bowels and inhibits the bowel walls from contacting the distal edge of the staple assembly as insufflation causes the bowel walls to squeeze around the instrument.

[0015] In embodiments, the tip member is movable from an expanded position, wherein the proximal end contacts the staple assembly, to a collapsed position, wherein the tip member is movable proximally through the plurality of staples. In one embodiment, the proximal end of the tip member is in contact with the distal surface of the staple assembly in the expanded position. In other embodiments, the proximal end of the tip member is disposed radially outward from (or inward from) the distal surface of the staple assembly in the expanded position.

[0016] The tip member is preferably designed to substantially cover the entire distal surface of the staple assembly in the expanded position. In an exemplary embodiment, the out4er surface of the tip member creates a substantially continuous surface with the outer surface of the staple assembly when the tip member is expanded. This ensures that the sharp edges of the circular staple assembly generally do not contact or “catch” on the bowel tissue as the instrument is navigated therethrough. In addition, it allows the user to employ a staple assembly with a relatively large diameter to improve the stapling process without impacting navigation of the staple assembly to the target location within the bowel.

[0017] In embodiments, the stapling instrument further comprises a retraction member coupled to the tip member for proximally retracting the tip member. In an exemplary embodiment, the retraction member comprises an elongate flexible member extending through the staple assembly.

[0018] In embodiments, the tip member comprises an internal surface and a groove, perforation, fold, cleft or other discontinuity extending along the internal surface. In an exemplary embodiment, the groove comprises a groove or perforation. The elongate flexible member has a proximal end coupled to the groove or perforation.

[0019] In one embodiment, the groove / perf oration extends along the internal surface of thetip member in a substantially spiral direction. The tip member comprises at least a first portion and a second portion. The first portion is detachable from the second portion at the groove. When the retraction member is translated in a proximal direction, the groove / perforation enables the tip to separate from itself, peeling along the spiral groove / perforation. In some embodiments, this changes the shape of the design from a cone to a substantially linear shape, such as ribbon, which allows the tip to be retracted from the bowel from within the instrument.

[0020] In embodiments, the surgical instrument further comprises an actuator for translating the retractable member in the proximal direction to collapse the tip member and withdraw the tip member through the staple assembly. In one embodiment, the actuator is coupled to a motor for automatic retraction of the tip member. The motor may be actuated by a user, or it may be coupled to a remote controller, such as a robotic control system.

[0021] In another embodiment, the tip member comprises a plurality of components removably coupled to each other. The plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly. The components may be positioned within the staple assembly in the second position, or they may be retracted through the shaft of the instrument.

[0022] In an exemplary embodiment, the components comprise spring loaded lobes that extend over the central opening of the staple assembly. The lobes may be positioned laterally inside of the plurality of staples. The lobes may protrude distally of the staple assembly to create an atraumatic (e.g., cone) shape in front of the distal surface of the staple assembly.

[0023] In some embodiments, the surgical instrument may further comprise a retraction member for collapsing the lobes into the second position proximal to the distal surface of the staple assembly. In another embodiment, the lobes are designed such that the tissue urges the lubes through the central opening of the staple assembly as the anvil is clamped thereto.

[0024] In certain embodiments, the lobes may be designed for positioning within an inner cavity of the staple assembly. In other embodiments, the lobes may be withdrawn through the shaft of the instrument.

[0025] In an exemplary embodiment, the lobes may each comprise a magnet disposed within the lobe, or on a surface thereof. The magnet(s) are designed to cooperate with anactuator, such as a permanent magnet, or one or more magnets having opposite polarity with the magnets within the lobes. The actuator may be used to move the lobes between the first and second positions. In some embodiments, the actuator is coupled to a remote controller, such as a robotic control system.

[0026] In yet another embodiment, the tip member comprises a plurality of components that generally curve towards a longitudinal axis of the instrument to create an atraumatic tip shape. The components may comprise petals, leaves, blades or the like that are designed to advance or sleeve over the staple assembly and retract proximally to expose the staple assembly during the clamping, dissection and stapling operation. The petals may be designed with a relatively thin thickness to inhibit distension of the bowel as they are retracted around the staple assembly. In certain embodiments, the petals may be designed to deform as they slide proximally past the staple assembly such that they can be positioned proximal of the staple assembly in the empty space of the bowel.

[0027] In embodiments, the instrument further comprises an anvil positioned distal to the staple assembly, a cutting element and a driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly. With this configuration, the staples are fully formed before the cutting element contacts the tissue. Thus, cutting of the tissue only begins after the staples have deformed against the anvil and joined the tissue structures together. This inhibits or prevents tissue displacement during staple formation, resulting in proper staple formation, a more uniform thickness of stapled tissue and an improvement in cut quality, which reduces the risk of an anastomotic leak.

[0028] In embodiments, the driver comprises one or more mechanisms configured to advance the staples and the cutting element towards the anvil simultaneously. In other embodiments, the driver comprises one or more mechanisms configured to sequentially advance the staples and then the cutting element towards the anvil.

[0029] In embodiments, the instrument comprises a first pusher coupled to the staples and a second pusher coupled to the cutting element or knife. The first and second pushers cooperate with the driver to advance the staples and the knife distally towards the anvil.

[0030] In embodiments, the driver comprises a rotatable element coupled to the first and second pushers. Rotation of the driver causes longitudinal movement of the first and second pushers. In certain of these embodiments, the knife is proximally recessed from the staples inthe initial position prior to the advancement of the knife and the staples by the driver. Thus, the driver must advance the knife a greater distance than the staples, which ensures that the staples deploy before the knife extends from the distal end of the staple assembly to sever the tissue.

[0031] In embodiments, the driver comprises proximal threads coupled to the first pusher and distal threads coupled to the second pusher. The first and second pushers each comprise threads configured to cooperate with the proximal and distal threads of the driver, respectively, to advance the first and second pushers upon rotation of the driver.

[0032] In an exemplary embodiment, the proximal and distal threads of the driver are longitudinally spaced from each other to define a gap therebetween. After the staples are fully deployed, the proximal threads on the driver disengages from the threads on the staple pusher while the distal threads of the driver are still engaged with the threads of the knife pusher. This ensures that the staple pusher no longer advances after staple formation, while the knife pusher continues to advance distally to cut the tissue.

[0033] In another embodiment, the staple pusher comprises a proximal cam surface and the driver comprises one or more distal protrusions or “followers” configured to contact the proximal cam surface such that rotation of the driver causes the follower(s) to move along the proximal cam surface. The proximal cam surface is inclined such that it extends at a transverse angle relative to a vertical plane that is substantially perpendicular to the longitudinal axis of the instrument. Rotation of the driver and the follower(s) translates the staple pusher in a longitudinal direction.

[0034] In embodiments, the proximal cam surface of the staple pusher includes a first portion that is inclined as described above and a second portion that is substantially flat such that it is substantially parallel to the plane perpendicular to the longitudinal axis of the instrument. This second portion creates a “dead zone” wherein rotation of the driver no longer advances the staple pusher in the longitudinal direction.

[0035] In embodiments, the knife pusher also includes a proximal cam surface and the driver includes one or more distal protrusions or followers configured to contact the proximal cam surface of the knife pusher such that rotation of the driver causes the distal protrusion to move along the proximal cam surface. The proximal cam surface is inclined such that it extends at a transverse angle relative to a vertical plane that is substantially perpendicular to the longitudinal axis of the instrument. Similar to the staple pusher, rotation of the driver andthe distal protrusion translates the knife pusher in a longitudinal direction.

[0036] In embodiments, the staple pusher comprises an internal channel and the proximal cam surface of the knife pusher extends through the internal channel proximally of the proximal cam surface of the staple pusher. The proximal cam surface of the knife pusher is substantially aligned with the second portion or “dead zone” of the proximal cam surface of the staple pusher. With this configuration, the follower simultaneously contacts the proximal cam surface of the knife pusher and the dead zone of the staple pusher cam surface such that the knife is advanced distally while the staple pusher remains in place.

[0037] In embodiments, the anvil head comprises first and second components movable relative to each other and configured for deploying between a collapsed configuration with a first diameter and an expanded configuration with a second diameter larger than the first diameter.

[0038] The first and second components are configured, in the expanded configuration, to form a tissue contacting surface that resists the forces applied by the stapler instrument during the clamping and stapling operations. In addition, the staple pockets on the tissue contact surface are configured, in the expanded configuration, to align with the staples in the staple assembly such that the staples form properly within the pockets.

[0039] In an exemplary embodiment, the anvil has an outer dimension or diameter of less than about 14 mm in the collapsed configuration such that the anvil may be advanced through a cannula or other percutaneous entry point in the patient. This allows the surgeon to introduce the anvil in a collapsed state through a percutaneous penetration in the patient, such as a cannula, and then expand the anvil within the target site, such as the proximal bowel, for the stapling operation. In addition, the anvil may be collapsed after the procedure to facilitate removal of the anvil and reduction of stress on the staple line.

[0040] In another embodiment, the instrument further comprises a delivery instrument for the anvil comprising an elongate shaft with first and second jaws movable between open and closed positions and a driver extending through the shaft. The driver has an engagement mechanism for engaging the anvil and moving the anvil between a collapsed configuration and an expanded configuration. The instrument allows the surgeon to introduce the anvil in a collapsed state through a percutaneous penetration in the patient, such as a cannula, and then expand the anvil within the target site, such as the proximal bowel, for the stapling operation. In addition, the instrument allows the surgeon to collapse the anvil to facilitate removal of theanvil and reduction of stress on the staple line.

[0041] In embodiments, the driver comprises a rod extending at least partially through the first and second jaws. The engagement element may comprise a rotatable element on a distal end of the rod, or the engagement element may comprise a distal portion of the rod. The rod is configured to cooperate with an interface on the anvil such that rotation of the rod relative to the instrument shaft (or rotation of the rotatable element relative to the rod) causes the anvil to move between the collapsed and expanded configurations.

[0042] In another aspect, a retractable tip for use with a circular stapling instrument is provided. The tip comprises a main body having a substantially circular proximal end and a distal end having a diameter smaller than a diameter of the proximal end. The tip further comprises an actuator configured to move the main body from an expanded position to a collapsed position, wherein the tip is retractable through at least a portion of the circular stapling instrument in the collapsed position.

[0043] In embodiments, the tip member is retractable through the shaft of the instrument. The tip member may for retractable through a central opening disposed within the staples in the distal surface of the staple assembly. This ensures that the tip member does not contact, distend or otherwise damage bowel tissue as it is removed from the surgical site.

[0044] In embodiments, the tip member comprises a proximal end adjacent to, or near, the distal surface of the staple assembly and a distal end having a smaller diameter than the proximal end. In some embodiments, the tip member tapers towards the distal end to create a gradual transition, which allows the user to splay the anal sphincter with minimal trauma. The tip member may have a shape that substantially resembles a cone, a triangular based pyramid, a square based pyramid or the like.

[0045] In an exemplary embodiment, the retraction member comprises an elongate flexible member extending through the staple assembly. The tip member comprises an internal surface and a groove or perforation extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove. The groove may extend along the internal surface of the tip member in a substantially spiral direction. The tip member comprises a first portion and a second portion. The first portion is detachable from the second portion at the groove. When the retraction member is translated in a proximal direction, the groove / perforation enables the tip to separate from itself, peeling along the spiral groove / perforati on .

[0046] In another embodiment, the tip member comprises a plurality of components removably coupled to each other. The plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly. The components are positioned with the staple assembly in the second position.

[0047] In an exemplary embodiment, the components comprise spring loaded lobes that just cover the central opening of the staple assembly. The lobes may be positioned disposed laterally inside of the plurality of staples. The lobes may protrude distally of the staple assembly to create an atraumatic (e.g., cone) shape in front of the distal surface of the staple assembly

[0048] In another aspect, a surgical system comprises a circular stapler instrument comprising an elongate shaft and a staple assembly with a plurality of staples, a retractable tip configured for positioning distal to the staple assembly and an actuator configured to retract the retractable tip proximally through the staple assembly. The system further comprises a controller coupled to the actuator for causing the actuator to retract the tip.

[0049] In embodiments, the system comprises manipulator arm coupled to the actuator and an input device movable to provide a desired movement of the actuator. The controller is configured to control movement of the retractable tip based on the movement of the input device.

[0050] In embodiments, the circular stapling instrument further comprises an anvil and a driver for advancing the staples towards the anvil. The system further comprises a second controller for actuating the driver.

[0051] In embodiments, the staple assembly further comprises a cutting element. The system comprises a third controller configured to advance the cutting element towards the anvil. In some embodiments, the second and third controllers are the same element and may advance the cutting element simultaneously or sequentially with the staples.

[0052] In embodiments, the actuator comprises a retraction member extending through the staple assembly. In an exemplary embodiment, the retraction member comprises an elongate flexible member extending through the staple assembly.

[0053] In another aspect, a circular stapling instrument comprises an elongate shaft, astaple assembly on a distal end portion of the shaft and comprising a distal surface and a plurality of staples, an anvil positioned distal to the staple assembly, cutting element and driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly. The instrument further comprises an atraumatic tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface of the staple assembly.

[0054] In embodiments, the tip member is retractable through the staples to a position proximal of the distal surface. In one embodiment, the tip member is retractable into the central opening of the staple assembly to a position proximal of the distal surface. The tip member may be retractable through an internal lumen with the shaft.

[0055] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the description. Additional features will be set forth in part in the description which follows or may be learned by practice of the description.BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and other aspects, features, and advantages of the present surgical instruments will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

[0057] FIG. 1 A is a perspective view of a circular stapling instrument;

[0058] FIG. IB is a perspective view of another circular stapling instrument;

[0059] FIG. 2 is an exploded view of a representative circular stapling instrument with an anvil and without the distal tip;

[0060] FIG. 3 is an enlarged view of a staple pusher of the representative circular stapling instrument of FIG. 2;

[0061] FIG. 4 is an enlarged view of a distal tip of a circular stapling instrument;

[0062] FIGS. 5A-5C illustrate collapsing the distal tip for retraction;

[0063] FIGS. 6A and 6B illustrate retraction of the distal tip through the circular stapling instrument;

[0064] FIG. 7A is a perspective view of another embodiment of a distal tip for a circular stapling instrument in a forward position;

[0065] FIG. 7B illustrates the distal tip in a retracted position;

[0066] FIG. 7C is a front view of the distal tip in the retracted position;

[0067] FIG. 7D illustrates separation of first and second components of the distal tip;

[0068] FIG. 8A is a partial side-sectional view of a circular stapling instrument with the distal tip of FIG. 7A in a forward position;

[0069] FIG. 8B is a partial si de- sectional view of a circular stapling instrument with the distal tip in a retracted position;

[0070] FIG. 9A is a perspective view of another embodiment of a distal tip for a circular stapling instrument, in a forward position;

[0071] FIG. 9B illustrates the distal tip of FIG. 9A in a retracted position;

[0072] FIG. 10 illustrates a circular stapling instrument being inserted into an anus of a patient for a bowel resection procedure

[0073] FIG. 11A is a side view of a circular stapling instrument advancing through the bowel;

[0074] FIG 1 IB is a side view of a prior art circular stapling instrument advancing through the bowel;

[0075] FIG. 12 is a perspective view of a distal end of a circular stapler;

[0076] FIG. 13 is a perspective view of a staple assembly for the circular stapler of FIG.12;

[0077] FIG. 14 is an exploded view of the staple assembly;

[0078] FIG. 15 is a proximal view of one portion of the staple assembly;

[0079] FIG. 16 illustrates the staple assembly in an initial position;

[0080] FIG. 17 illustrates the staple assembly in a second position;

[0081] FIG. 18 illustrates the staple assembly in a third position;

[0082] FIGS. 19 illustrates the staple assembly in a fourth position;

[0083] FIG. 20 illustrates the staple assembly in a final position;

[0084] FIG. 21 is an alternative embodiment of a driver for the staple assembly;

[0085] FIGS. 22A-22D schematically illustrate operation of the devices described herein for sealing and cutting tissue;

[0086] FIG. 23 is a partial cross-sectional view of a staple assembly of a circular stapler;

[0087] FIG. 24 is an exploded view of an end effector of the circular stapler of FIG. 23;

[0088] FIG. 25A is an enlarged view of a staple pusher;

[0089] FIG. 25B is an end view of a housing for the staple assembly;

[0090] FIG. 26 illustrates the end effector of the circular stapler in an initial position;

[0091] FIG. 27 illustrates the end effector with a plurality of staples engaging an anvil;

[0092] FIG. 28 illustrates the end effector with a knife deploying past the distal end of the channel to cut tissue;

[0093] FIGS. 29A-29D illustrate the operation of an alternative embodiment of a circular stapler;

[0094] FIGS. 30A-30D illustrate the operation of an alternative embodiment of a circular stapler;

[0095] FIGS. 31A-31C illustrate the operation of an alternative embodiment of a circular stapler;

[0096] FIG. 32 is a partial cross-sectional view of another alternative embodiment of a circular staple;

[0097] FIG. 33 illustrates the circular stapler of FIG. 32 deploying a plurality of staples;

[0098] FIG. 34 illustrates the circular stapler of FIG. 32 deploying the knife to cut tissue;

[0099] FIGS. 35A-35C are cross-sectional views of another embodiment of a circular stapler;

[0100] FIGS. 36A-36C illustrate one embodiment of a collapsible anvil for a circular stapler;

[0101] FIG. 37 illustrates another embodiment of a collapsible anvil for a circular stapler;

[0102] FIGS. 38A-38C illustrate the deployment of an anvil head of the anvil of FIG. 37;

[0103] FIGS. 39A and 39B illustrates another embodiment of an anvil for a circular stapler;

[0104] FIG. 40 A illustrates another embodiment of an anvil for a circular stapler in anexpanded configuration;

[0105] FIG. 40B illustrates the anvil of FIG. 40A in an expanded configuration;

[0106] FIGS. 41A and 41B illustrate another embodiment of a collapsible anvil for a circular stapler;

[0107] FIGS. 42A-42C illustrate deployment of the anvil of FIGS. 41A and 41B;

[0108] FIGS. 43A and 43B illustrate another embodiment of a collapsible anvil for a circular stapler;

[0109] FIGS. 44A-44C illustrate another embodiment of a collapsible anvil for a circular stapler;

[0110] FIGS. 45A and 45B illustrate another embodiment of a collapsible anvil for a circular stapler;

[0111] FIGS. 46A-46C illustrates deployment of the anvil of FIGS 45 A and 45B;

[0112] FIG. 47 is a perspective view of the distal end portion of a delivery instrument for the anvil;

[0113] FIG. 48 illustrates the delivery instrument with closed jaws for advancing the anvil to a target region within a patient;

[0114] FIG. 49 illustrates the delivery instrument after expanding the anvil at the target region;

[0115] FIG. 50 illustrates the delivery instrument manipulating a shaft of an anvil of a circular stapler;

[0116] FIG. 51 illustrates the jaws of the delivery instrument grasping the anvil shaft;

[0117] FIG. 52 is a perspective view of a representative teleoperated surgical instrument;

[0118] FIG. 53 illustrates a top view of an operating room employing a robotic surgical system; and

[0119] FIG. 54 illustrates a simplified side view of a robotic arm assembly.DETAILED DESCRIPTION

[0120] Particular embodiments of the present surgical instruments are described hereinbelow with reference to the accompanying drawings; however, it is to be understood thatthe disclosed embodiments are merely exemplary and may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the devices herein in virtually any appropriately detailed structure. Well-known functions or constructions are not described in detail to avoid obscuring the present description in any unnecessary detail. Like numbers in two or more figures represent the same or similar elements. Furthermore, elements and their associated aspects that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. Moreover, the depictions herein are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the system or illustrated components.

[0121] While the following is presented with respect to circular stapling instruments, it should be understood that certain features of the presently described surgical instruments may be readily adapted for use in any type of surgical clamping, cutting, ligating, dissecting, clipping, cauterizing, suturing and / or sealing instrument, whether or not the surgical instrument applies a clip or other type of fastener. Additionally, the features of the presently described circular stapling instruments may be readily adapted for use in surgical instruments that are actuated using any technique within the purview of those skilled in the art, such as, for example, manually activated surgical instruments, powered surgical instruments (e.g., electro- mechanically powered instruments), robotic surgical instruments, and the like.

[0122] The devices described herein, or certain components of the devices, may also be incorporated into a variety of different circular stapling instruments, such as those described in commonly assigned, co-pending US. Provisional Patent Application Nos. 63,621,476, 63 / 621,469, and 63,621,462, all filed on January 16, 2024, the complete disclosures of which are incorporated by reference herein in their entirety for all purposes as if copied and pasted herein.

[0123] Fig. 1A illustrates a distal portion of a surgical circular stapling instrument 100 in accordance with an illustrative embodiment. Surgical instrument 100 includes an end effector 110, an elongated shaft 105 and, in some embodiments, a wrist assembly (not shown) couplingend effector 110 to shaft 105. End effector 110 generally comprises a circular stapling assembly 120, an anvil 130 and a capturing device 140 (see FIG. 2) for advancing and retracting anvil 130 relative to stapling assembly 120, as discussed in more detail below. Surgical instrument 100 further comprises a retractable tip member 150 that may be positioned distal to stapling assembly 120 (discussed below in reference to 4 and 5A-5C).

[0124] In these embodiments, instrument 100 will generally include an actuation mechanism that controls the orientation and movement of the end effector 110. The actuation mechanism will typically be controlled by a robotic manipulator assembly that is controlled remotely by a user. In certain embodiments, surgical instrument 100 will further include a backend mechanism 115 coupled to the proximal end portion of elongate shaft 105. The backend mechanism typically provides a mechanical coupling between the drive tendons, rods or cables of the instrument and motorized axes of the mechanical interface of a drive system. Further details of known backend mechanisms and surgical systems are described, for example, in U.S. Pat. No. 8,597,280, U.S. Pat. No. 7,048,745, and U.S. Pat No. 10,016,244. Each of these patents is hereby incorporated by reference in its entirety.

[0125] The input couplers may interface with, and be driven by, corresponding output couplers (not shown) of a telesurgical surgery system, such as the system disclosed in U.S Pub. No. 2014 / 0183244A1, the entire disclosure of which is incorporated by reference herein. The input couplers are drivingly coupled with one or more input members (not shown) that are disposed within the instrument shaft 105. The input members are drivingly coupled with the end effector 110. Suitable input couplers can be adapted to mate with various types of motor packs (not shown), such as the stapler-specific motor packs disclosed in U.S. Pat. No. 8,912,746, or the universal motor packs disclosed in U.S. Pat. No. 8,529,582, the disclosures of both of which are incorporated by reference herein in their entirety. Further details of known input couplers and surgical systems are described, for example, in U.S. Pat. No. 8,597,280, U.S. Pat. No. 7,048,745, and U.S. Pat No. 10,016,244. Each of these patents is hereby incorporated by reference in its entirety for all purposes.

[0126] Proximal housing 115 may include an instrument memory or storage device (not shown). The memory can perform a number of functions when the instrument is loaded on a manipulator arm (not shown) of a robotic control system. For example, the memory can provide a signal verifying that the instrument is compatible with that particular surgical system. Additionally, the memory may identify the instrument and end effector type (whether it is ascalpel, a needle grasper, jaws, scissors, a clip applier, an electrocautery blade, or the like) to the surgical system so that the system can reconfigure its programming to take full advantage of the instrument's specialized capabilities. As further discussed below, the memory may include specifics on the architecture of the instrument, and include particular values that should be employed in control algorithms, such as tool compliance and gain values.

[0127] Proximal housing 115 also may include a force / torque drive transmission mechanism (not shown) for receiving output from the motors of the manipulator arm. The force / torque drive transmission mechanism transmits the output from the motors to end effector 110 of the instrument through instrument shaft 105. Exemplary surgical robotic instruments, instrument / manipulator arm interface structures, and data transfer between the instruments and servomechanism is more fully described in U.S. Pat. No. 6,331,181, the full disclosure of which is incorporated herein by reference.

[0128] While described herein with respect to an instrument configured for use with a robotic surgical system, it should be understood that the actuation and drive assemblies described herein may be incorporated into manually actuated instruments, electro-mechanical powered instruments, or instruments actuated in any other way. For example, as shown in FIG. IB, an instrument 100a may comprise a handle assembly 115a for gripping by the user that includes a stationary handle 116 and a moveable handle 117 for controlling the orientation and movement of end effector 110a. Similar to the above embodiment, end effector 110a may comprise a staple assembly 120a and a retractable tip member 150a coupled thereto.

[0129] FIGS. 2 and 3 illustrate a representative stapling assembly 120 for use with retractable tip member 150 and instruments 100, 100a. Although it will be understood that retractable tip member 150 may be used with a wide variety of different staple assemblies 120 for use with circular staplers. As shown, assembly 120 comprises a proximal housing 150 having a substantially cylindrical main body 152 with an internal channel 154 for receiving a cutting element assembly 160, a staple pusher 170 and a staple cartridge 180. Housing 150 couples the stapling assembly 120 to shaft 105. In some embodiments, housing 150 may comprise an inclined surface 153 that tapers inwardly in the proximal direction to accommodate a stapling assembly 120 having a larger diameter than shaft 105.

[0130] Stapling assembly 120 may be removably coupled to shaft 105, or permanently affixed thereto. In certain embodiments, stapling assembly 120 is a disposable component of instrument 120 and may be removably attached to shaft 105. In other embodiments, staplecartridge 180 is a disposable component of instrument and may be removably coupled to staple assembly 120. In other embodiments, the entire instrument 120 is manufactured together and may be either a disposable or reusable instrument.

[0131] As shown in FIG. 2, anvil 130 includes an anvil head 132 and an anvil shaft 134. Anvil shaft 134 is insertable into internal channel 154 of housing 150 and is removably and slidably securable therein. Capturing device 140 is configured to advance and withdraw through channel 154 to translate anvil 130 along a longitudinal axis relative to staple assembly 120 to approximate or un-approximate anvil 130 relative to staple assembly 120. Anvil head 132 includes a tissue contacting surface 136 defining staple forming pockets (not shown) for receiving staples 200, as discussed below in reference to FIGS. 22A-22D.

[0132] As shown in FIG. 3, staple pusher 170 defines a substantially cylindrical shape and is coaxially and slidably disposed within internal channel 154 of housing 150. Staple pusher 170 includes a main body 174 and at least one annular array of staple engagement members or fingers 176 extending from the distal end of body 174. Each finger 176 is configured to be received within a slot of staple cartridge 180 to engage staples 200. Staple pusher 170 is configured to advance relative to housing 150 to engage, drive and eject staples 200 against the staple forming pockets of anvil 130. As shown in FIG 2., fingers 176 of staple pusher 170 are recessed proximally from the distal end of housing 150 to provide room for staple cartridge 180.

[0133] Staple cartridge 180 may include one, two or more than two annular arrays or rows of fingers with staple receiving slots (not shown) for receiving one or more sets of concentric staple arrays 200. Staple cartridge 180 is removably or permanently coupled to staple pusher 170 such that staple pusher 170 may drive staples 200 from cartridge 180 into tissue (discussed in more detail below). In particular, distal fingers 176 of staple pusher 170 are configured to advance into the slots of cartridge 180 to drive staples 200 distally.

[0134] In certain embodiments, staple cartridge 180 comprises an annular main body 182 with circumferential slots (not shown) that extend between the distal end of an array of distal fingers 176 on staple pusher 170 and the inner surface of housing 150. The circumferential slots function to align staples 200 with fingers 176 of staple pusher 170 such that distal movement of staple pusher 170 causes staples 200 to move distally to engage and deform against tissue contacting surface 136 of anvil 130.

[0135] Cutting element assembly 160 generally comprises an annular pusher 164 and anannular cutting element or knife 166 at the distal end of pusher 164. Pusher 164 is configured to advance relative to housing 150 to drive knife 166 through tissue disposed between anvil 130 and stapling assembly 120.

[0136] Staple assembly 120 comprises a distal surface 202 of the annular main body 182 of staple cartridge 180 (see FIG. 4). Distal surface 202 is substantially flat and circular and surrounds an internal channel 204 that receives cutting element 166 and capturing element 140 (see FIG. 2).

[0137] Referring now to FIG. 4, retractable tip member 150 comprises a proximal end 212 adjacent to, or in contact with, distal surface 202 of staple cartridge 180. Proximal end 212 preferably has a diameter substantially equal to the diameter of distal surface 202 of staple cartridge 180. In certain embodiments, proximal end 212 of tip member 150 substantially covers distal surface 202 such that the instrument defines a relatively smooth outer surface between staple assembly 120 and tip member 150 (see FIG. 5 A discussed in more detail below). In other embodiments, proximal end 212 may have a larger diameter than distal surface 202 such that proximal end 212 extends past the outer diameter of distal surface 202. In yet another embodiment, proximal end 212 may also extend proximally of distal surface 202 along a distal portion of the outer surface of staple cartridge 180.

[0138] Tip member 150 further comprises a distal end 214 having a smaller diameter than proximal end 212. Distal end 214 may comprise a rounded or sharp tip at the distal end of member 150. In an exemplary embodiment, distal end 214 has an outer dimension or diameter that is a ratio of the outer dimension or diameter of proximal end 212. This ratio is preferably about 1 :2 or less, or about 1 :3 or less, or about 1 :4 or less.

[0139] Tip member 210 may comprise any suitable shape, such as conical or pyramidal, so long as distal end 214 has a smaller diameter than proximal end 212 and the main body 216 substantially tapers therebetween. In an exemplary embodiment, tip member 150 comprises a generally conical main body 216 between proximal and distal ends 212, 214 that creates a gradual transition from staple cartridge 180 to distal end 214. Tip member 150 may comprise any suitable material that is strong enough to resist forces applied to tip member 150 as it splays the anal sphincter and navigates through the bowel (discussed below).

[0140] Referring now to FIG. 5B, tip member 150 comprises one or more grooves, perforations, folds, clefts or other discontinuities extending along its inside surface. In certain embodiments, a groove 260 extends in a substantially spiral direction around the inside surfacefrom proximal end 212 to distal end 214 although it will be recognized that other configurations are contemplated. The interior of tip member 150 may be substantially hollow, or it may comprise a central channel or lumen (not shown) sized for receiving an actuator (discussed below).

[0141] Instrument 100 further comprises an actuator or drive member for retracting tip member 150 through internal channel 204 of staple assembly 120. In certain embodiments, the actuator or drive member is configured to collapse tip member 150 into a configuration that has a smaller overall diameter such that tip member 150 may be withdrawn through channel 204 and into staple assembly 120. In one such embodiment, tip member 150 may be collapsed into a small enough diameter to be withdrawn through a lumen in shaft 105.

[0142] In an exemplary embodiment, the actuator or drive member comprises an elongate flexible member 250, such as a tail, string, thread, filament or the like, that is coupled to groove 260 within the interior of tip member 150, preferably near distal end 214 (see FIG. 5B). Tail 250 is configured such that proximal withdrawal of tail 250 causes tip member 250 to separate from itself along groove 260, which in certain embodiments, changes the shape of tip member 250 to change from a cone to a substantially linear or elongate shape, such as a ribbon or the like (see FIG. 5C). Further withdrawal of tail 250 causes the tip member 250 to be withdrawn into channel 204 and through the shaft 105 of instrument 100 (see FIGS. 6A and 6B).

[0143] Tail 250 may be operated manually or automatically. In one embodiment, proximal housing 115 (or handle 115a) may include an opening 280 that allows tail 250 to pass therethrough. Tail 250 may include a proximal end 282 for grasping by the user to pull tail 250 proximally. Proximal end 282 may comprise a loop, coil, twist or other configuration to facilitate handling. In another embodiment, the actuator is coupled to a motor (not shown) within housing 115 for automatic retraction of the tip member. The motor may be actuated by a user, or it may be coupled to a remote controller, such as a robotic control system.

[0144] Referring now to FIG. 10, instrument 100 is particularly useful for joining two tubular structures in a patient, such as arteries, veins, and / or intestinal tissue. For example, in a lower colon procedure, the surgeon typically uses a conventional linear stapler with two rows of staples placed on either side of the affected intestinal lesion to be removed and stapled. The target area is cut at the same time as the adjacent ends are stapled. After removing the affected area, the surgeon typically inserts anvil 130 (discussed below) and then must introduce staple assembly 120 through the anal sphincter 400 and navigate it through the bowel 402 to the targetsite in a more distal region 408 of the bowel.

[0145] As shown in FIG. 10, tip member 150 provides a more atraumatic leading end for the stapling instrument as it is introduced through the anus 400 and navigated through the bowel 402 of the patient. This reduces soft tissue trauma to the patient. In addition, since tip member 150 can be inserted gradually through anus 400, the user is not required to apply high force to insert the instrument, which eliminates the “stick-slip” phenomenon that would otherwise occur (i.e., a user must suddenly stop the instrument after passing through the anus 400 to avoid trauma to the distal rectal stump beyond the anus).

[0146] Almost immediately after passing through anus 400, tip member 150 must be navigated around a relatively sharp curve 404 in the bowel 402 to reach the target region, which is typically distal to this curve 404 (i.e., region 408 in FIG. 10). At this point in the procedure, the surgeon cannot see tip member 150 and must navigate through feel and experience. With a conventional circular stapling instrument, the flat head of staple assembly contacts curve 404, which presents a significant amount of resistance to further advancement of staple assembly 120. In addition, this resistance tends to cause the proximal end of instrument 100 to rotate downwards (relative to the structures shown in FIG. 10) such that staple assembly 120 rotates into the curve 404 (i.e., the resistance naturally causes staple assembly 120 to want to rotate into the curve, which causes more resistance and provides the feeling to the user that the staple assembly has run into a wall within the bowel).

[0147] With the atraumatic tip member 150 described herein, the tapered main body 216 contacts curve 404 and naturally curves downward (relative to the structures in the page), causing the proximal end of the instrument to rotate upwards. Thus, tip member 150 automatically orients the instrument in the proper direction to pass curve 404 and advance into the distal region 408 of bowl 402.

[0148] Referring now to FIGS. 11A and 11B, tip member 150 provides additional advantages for navigating through the bowel, particularly when the patient cavity has been insufflated. As shown in FIG. 1 IB, with a conventional circular stapling instrument 450, this insufflation causes the walls 432 of the bowel to squeeze around the annular surface 454 of the circular staple assembly 452, which increases the amount of contact with the sharp distal edges 456 of the staple assembly 452. In addition, the bowl walls 432 tend to squeeze into the internal cavity 458 within the staple assembly 452, which increases resistance to further advancement of the instrument.

[0149] With the tip members described herein, there are no sharp edges around staple assembly 120 that contact the bowel 402 (see FIG. 11 A). In addition, the bowel walls do not squeeze around the sharp distal ends of staple assembly 120 and cannot enter the internal cavity of staple assembly 120. This significantly improves navigation. In addition, this allows the user to select a larger diameter stapler to achieve the largest internal diameter after stapling, thereby improving the seal on the anastomosis.

[0150] Referring now to FIGS. 7A-7D, 8A and 8B another embodiment of a retractable tip member 300 will now be described. As shown, tip member 300 includes a plurality of separate components 302, 304, 306 that are configured to move between a forward deployed position (see FIG. 8A), wherein the components combine to form an atraumatic shape with a distal end having a smaller diameter than the proximal end, to a retracted position within channel 204 of staple assembly 120 (see FIG 8B). In one embodiment, components 302, 304, 306 each form a lobe having a semi -spherical cross-sectional shape that tapers inwardly from the proximal end to the distal end. Components 302, 304, 306 may each comprise a magnet 310 disposed within each component, or on the surface of the components. Magnets 310 may serve to draw components together in the forward position such that they remain in this position as tip member 300 is advanced through the patient’s bowel. In certain embodiments, instrument 100 may also comprise one or more biasing elements, such as springs or the like (not shown) that bias tip member 300 into the forward position. This ensures that components 302, 304, 306 will not retract as instrument 100 is advanced through the bowel.

[0151] Tip member 300 may comprise an actuator or drive member for retracting components 302, 304, 306 into the internal channel of staple assembly 120. In certain embodiments, the actuator may comprise a magnet that acts on the magnets 310 within components 302, 304, 306 to retract tip member 300. In other embodiments, each of the components may be coupled to an elongate flexible member 330, such as the tail or string described above, and may be retracted in a similar manner. Components 302, 304, 306 are preferably sized to pass around capture element 140 so that they do not interfere with the operation of capturing the anvil 130 described above.

[0152] Referring now to FIGS. 9A and 9B, another embodiment of a retractable tip member 400 will now be described. As shown, tip member 400 includes a plurality of separate petals 402, 404, 406 that are configured to move between a forward deployed position (see FIG. 9A), wherein the petals combine to form an atraumatic shape with a distal end having asmaller diameter than the proximal end, to a retracted position proximal of distal surface 202 of staple assembly 120 (see FIG 9B). In this embodiment, pedals 402, 404, 406 are retracted along the outer surface of staple assembly 120.

[0153] Tip member 400 preferably comprises a thin cut tube having petals 402, 404, 406 that curve towards the longitudinal axis of instrument 100 in the forward position to create an atraumatic shape. Petals 402, 404, 406 preferably comprise a material that will remain substantially rigid during insertion and navigation. Petals 402, 404, 406 may be retracted by pulling tip member 400 in the proximal direction. Petals 402, 404, 406 deform as they slide proximally over staple assembly 120 so that they can be stored in the retracted position shown in FIG. 9B. Since the petals 402, 404, 406 are relatively thin, they will not substantially distend the bowel or cause tissue damage as they slide proximally over staple assembly 120.

[0154] Referring now to FIGS. 12-22D, one embodiment of circular stapling instrument 100b that may be used with the retractable tip members described herein includes an end effector 110, an elongated shaft 105 and, in some embodiments, a wrist assembly (not shown) coupling end effector 110 to shaft 105. End effector 110 generally comprises a circular stapling assembly 120, an anvil 130 and a capturing device 140 (see FIG. 13) for advancing and retracting anvil 130 relative to stapling assembly 120, as discussed in more detail below. The proximal end portion of elongate shaft 105 is operatively connected to an actuation mechanism (not shown), although as those skilled in the art reading this description will appreciate, components of the actuation mechanism may extend into, and / or pass through elongated shaft 105 and / or the wrist assembly.

[0155] Referring now to FIGS. 13 and 14, stapling assembly 120 comprises a housing 151 having a substantially cylindrical main body 152 with an internal channel 154 for receiving a cutting element assembly 160, a staple pusher 170 and a staple cartridge 180. Housing 151 couples the stapling assembly 120 to shaft 105. In some embodiments, housing 151 may comprise an inclined surface 153 that tapers inwardly in the proximal direction to accommodate a stapling assembly 120 having a larger diameter than shaft 105.

[0156] Stapling assembly 120 may be removably coupled to shaft 105, or permanently affixed thereto. In certain embodiments, stapling assembly 120 is a disposable component of instrument 120 and may be removably attached to shaft 105. In other embodiments, staple cartridge 180 is a disposable component of instrument and may be removably coupled to staple assembly 120. In other embodiments, the entire instrument 120 is manufactured together andmay be either a disposable or reusable instrument.

[0157] As shown in FIG. 12, anvil 130 includes an anvil head 132 and an anvil shaft 134. Anvil shaft 134 is insertable into internal channel 154 of housing 150 and is removably and slidably securable therein. Capturing device 140 is configured to advance and withdraw through channel 154 to translate anvil 130 along a longitudinal axis relative to staple assembly 120 to approximate or un-approximate anvil 130 relative to staple assembly 120. Anvil head 132 includes a tissue contacting surface 136 defining staple forming pockets (not shown) for receiving staples 200, as discussed below in reference to FIGS. 22A-22D.

[0158] As shown in FIG. 14, staple pusher 170 defines a substantially cylindrical shape and is coaxially and slidably disposed within internal channel 154 of housing 150. Staple pusher 170 includes a main body 174 and at least one annular array of staple engagement members or fingers 176 extending from the distal end of body 174. Each finger 176 is configured to be received within a slot of staple cartridge 180 to engage staples 200. Staple pusher 170 is configured to advance relative to housing 150 to engage, drive and eject staples 200 against the staple forming pockets of anvil 130. As shown in FIG. 13, fingers 176 of staple pusher 170 are recessed proximally from the distal end of housing 150 to provide room for staple cartridge 180.

[0159] Staple cartridge 180 may include one, two or more than two annular arrays or rows of fingers with staple receiving slots (not shown) for receiving one or more sets of concentric staple arrays 200. Staple cartridge 180 is removably or permanently coupled to staple pusher 170 such that staple pusher 170 may drive staples 200 from cartridge 180 into tissue (discussed in more detail below). In particular, distal fingers 175 of staple pusher 170 are configured to advance into the slots of cartridge 180 to drive staples 200 distally.

[0160] In certain embodiments, staple cartridge 180 comprises an annular main body 182 with circumferential slots (not shown) that extend between the distal end of an array of distal fingers 176 on staple pusher 170 and the inner surface of housing 151. The circumferential slots function to align staples 200 with fingers 176 of staple pusher 170 such that distal movement of staple pusher 170 causes staples 200 to move distally to engage and deform against tissue contacting surface 136 of anvil 130.

[0161] Referring now to FIG. 15, staple pusher 170 comprises a proximal cam surface 211 for engagement with a driver 190, which is discussed in more detail below. Cam surface 211 has a generally annular shape and extends around a central channel 2123 within staple pusher170 that extends substantially parallel to a longitudinal axis 215 of staple pusher 170 and stapling assembly 120. Cam surface 210 includes a first portion 220 that has an inclined surface, preferably having an angle transverse to a plane that is substantially perpendicular to longitudinal axis 215 (see FIG. 16). Thus, as first portion 220 of cam surface 211 extends in the clockwise direction, it also extends proximally (i.e., in the direction towards shaft 105) such that an upper section 222 of first portion 220 is disposed proximal to a lower section 224 of first portion 220. Of course, it will be recognized that the terms “upper” and “lower” are only used herein in reference to the orientation shown in FIG. 4. Sections 222, 224 may be in any orientation relative to each other depending on the overall orientation of instrument 100. Cam surface 211 includes a second portion 230 or “dead zone” (discussed below) that is substantially flat such that it extends generally parallel to the plane that is substantially perpendicular to longitudinal axis 215.

[0162] Cutting element assembly 160 generally comprises an annular pusher 164 and an annular cutting element or knife 166 at the distal end of pusher 164. In some embodiments, knife 166 is a sharpened distal extension of pusher 164. Pusher 164 is configured to advance relative to housing 150 to drive knife 166 through tissue disposed between anvil 130 and stapling assembly 120.

[0163] As shown in FIGS. 15 and 16, knife pusher 164 has a proximal cam surface 240 extending laterally inside of, and proximal to, cam surface 211 of staple pusher 170. As shown, cam surface 240 has an inclined surface having an angle transverse to the plane that is substantially perpendicular to longitudinal axis 215. Thus, as cam surface 240 extends in the clockwise direction, it extends proximally (i.e., in a direction towards shaft 105) such that a lower section 242 of surface 240 is disposed proximal to an upper section 224 of surface 220. Again, it will be recognized that the terms “upper” and “lower” are only used herein in reference to the orientation shown in FIG. 4. Cam surface 240 of knife pusher 164 is circumferentially aligned with the second portion 230 or dead zone of staple pusher cam surface 211 for reasons discussed below.

[0164] Instrument 100b further includes a driver 190 for advancing cutting element assembly 160 and staple pusher 170 towards anvil 130. Driver 190 comprises an internal lumen 198 extending therethrough. Capturing device 140 is configured for advancement through internal lumen 198 to engage and translate anvil 130 towards and away from stapling assembly 120. Driver 190 has a proximal end suitably coupled to an actuation mechanism (notshown) for rotating driver 190 relative to end effector 110. In some embodiments, instrument 100b comprises a wrist assembly (not shown) pivotally coupling end effector 110 with shaft 105. At least a portion of driver 190 is movable through the wrist assembly between shaft 105 and end effector 110. In one such embodiment, the wrist assembly comprises one or more linkages for articulating the end effector around first and second axes, respectively. The first and second axes may be, for example, yaw and pitch axes.

[0165] In embodiments, driver 190 comprises the distal portion described above for engaging the staple and knife pushers and a flexible portion (not shown) that extends through the wrist member when the distal portion is within end effector 110. The flexible portion allows the distal portion to articulate relative to the proximal portion when end effector 110 articulates about the wrist member. The drive member further comprises a proximal portion (not shown) extending through the shaft and configured for coupling to an actuator, such as instrument handle or an external control system. In embodiments, the flexible portion of driver 190 comprises a bendable laser cut hypo tube that extends through shaft 105 of instrument 100b. The hypo tube has sufficiently flexibility to bend as the end effector 110 is rotated relative to shaft 105.

[0166] As shown in FIG. 14, driver 190 comprises an annular body 250 having a distal surface 252 with at least one protrusion or follower 254 extending distally therefrom. Follower 254 is configured to contact cam surfaces 211, 240 of staple pusher 170 and knife pusher 164 and to ride along these cam surfaces 211, 240 as driver 190 rotates to translate this rotational movement into distal movement of staple pusher 170 and knife pusher 164. In one embodiment, driver 190 is rotatable such that follower 254 rotates therewith. In another embodiment, driver 190 comprises a mechanism for rotating follower 254 relative to body 250 such that the main body of driver 190 does not rotate, but follower 254 rotates around distal surface 252.

[0167] Referring now to FIG. 5, driver 190 starts in an initial position wherein follower 254 engages first portion 220 of staple pusher cam surface 211 near the lower section 224 of surface 210. As driver 190 rotates in the clockwise direction, follower 254 rides along first portion 220 of cam surface 211. Since this surface is inclined, this rotation causes staple pusher 170 to advance distally (i.e., in a direction away from shaft 105). Note that at this stage, follower 254 does not contact cam surface 240 of knife pusher 164 and, therefore, the knife 166 is not advanced distally.

[0168] Referring now to FIGS. 17 and 18, as follower 254 rides towards upper portion 222 of cam surface 211, staple pusher 170 continues to advance distally. Once follower 254 reaches second portion 230 or the dead zone of cam surface 211, it no longer advances staple pusher 170 because this portion 230 of cam surface 211 is substantially parallel to the plane perpendicular to longitudinal axis 214. At this point, the staples 200 have been driven against the anvil 130 and have fully formed through the tissue between anvil 130 and stapler assembly 120. Note that at this stage, follower 254 does not contact cam surface 240 of knife pusher 164 and, therefore, the knife 166 is not advanced distally. Thus, staples 200 are driven into the tissue and against tissue contacting surface 136 of anvil 130 before knife 166 extends distally of housing 151.

[0169] Referring now to FIGS. 18-20, as follower 254 continues to rotate in the clockwise direction, it contacts proximal cam surface 240 of knife pusher 164. Again, since this surface is inclined at an angle relative to the plane perpendicular to longitudinal axis 215, this rotation advances knife pusher 164 and knife 166 in the distal direction until knife 166 extends beyond the distal end of housing 151 and severs the tissue.

[0170] Applicant notes that in the embodiment shown in FIGS. 13-20, driver 190 includes only one protrusion or follower 254 that rides along the cam surfaces 211, 240 of staple pusher 170 and knife pusher 160 about 360 degrees in order to completely deploy both the staples 200 and the knife 166. However, it should be understood that other embodiments are contemplated. For example, first and / or second portions 220, 230 of the staple pusher cam surface 211 may extend less than 180 degrees around central channel 212. Alternatively, one of these portions may extend more than 180 degrees around central channel 212. For example, first portion 220 may extend between about 90 degrees to about 270 degrees and second portion 230 may extend between about 90 degrees to about 270 degrees.

[0171] In certain alternative embodiments, driver 190 is configured to advance knife pusher 160 and staple pusher 160 simultaneously such that staples 200 are fully formed prior to the knife 166 contacting the tissue. In one such embodiment, proximal cam surface 240 of knife pusher 160 may be aligned with first portion 220 of staple pusher cam surface 211 such that follower 254 contacts both of these surfaces simultaneously. However, knife 166 is proximally recessed from the distal end of staple pusher 160 such that driver 190 must advance knife pusher 164 a greater distance than staple pusher 160 in order for the respective knife and staples to contact tissue. Thus, staple pusher 160 is advanced distal of staple assembly 120before knife 166. In this embodiment, proximal cam surface 240 of knife pusher 160 may be aligned with both inclined cam surface 220 and flat or dead zone cam surface 230 of stapler pusher 160 such that rotation of driver 190 initially causes both staple pusher 170 and knife pusher 160 to move distally, and then the staple pusher 170 stops moving distally as knife pusher 160 continues to drive knife 166 into tissue.

[0172] In another such embodiment, the angle of staple pusher cam surface 211 is greater than the angle of knife pusher cam surface 240. In this embodiment, driver 190 advances staple pusher 170 more rapidly than knife pusher 170 such that the staples are fully formed before the knife contacts the tissue. Similar to the above embodiment, proximal cam surface 240 of knife pusher 160 may be aligned with both inclined cam surface 220 and flat or dead zone cam surface 230 of stapler pusher 160 such that rotation of driver 190 initially causes both staple pusher 170 and knife pusher 160 to move distally, and then the staple pusher 170 stops moving distally as knife pusher 160 continues to drive knife 166 into tissue.

[0173] In another alternative embodiment, driver 190 includes more than one follower 254 extending from distal surface 252. In this embodiment, for example, driver 190 may include two, three, four or more followers that ride along cam surfaces 210, 240 of staple pusher 170 and / or knife pusher 164 to provide additional stability and / or mechanical advantage to the instrument.

[0174] Referring now to FIG. 21, an alternative embodiment of a driver 290 comprises an annular body 261 having a distal surface 260 with first and second distal protrusions or followers 254, 255 extending therefrom. As shown, followers 254, 255 are spaced circumferentially about 180 degrees from each other around the annular body 261, although it should be recognized that other configurations are contemplated (i.e., followers 254, 255 may be spaced from each other about 90 to about 270 degrees around annular body 261, or driver 290 may comprises more than two followers). In this embodiment, cam surface 210 of staple pusher 170 may include four separate sections (two for each of the followers 254, 255). The first and second portions would be similar to the first and second portions 220, 230 described above, except that each would extend about 90 degrees around central channel 212. The third and fourth portions (not shown) would be similar to the first and second portions except that each would extend 90 degrees around central channel 212 on the opposite side of central channel 212 from the first and second portions. Thus, each follower 254, 255 would first ride along an inclined portion of the cam surface (simultaneously) to advance staple pusher forwardand then along a non-inclined or a flat surface that is substantially perpendicular to the longitudinal axis (i.e., the dead zone wherein the staple pusher is not advanced distally).

[0175] In this embodiment, knife pusher 164 may include one or two cam surfaces extending proximally of the staple pusher cam surface 211 and circumferentially aligned with the flat portion(s) 230 of cam surface 211 of staple pusher 270. Similar to the above embodiment, once the followers 254, 255 reach the knife pusher cam surfaces, the staples are fully driven and formed into the tissue.

[0176] Referring now to FIGS. 22A -22D, instrument 100b is particularly useful for joining two tubular structures in a patient, such as arteries, veins, and / or intestinal tissue 412. For example, in a lower colon procedure, the surgeon typically uses a conventional linear stapler with two rows of staples placed on either side of the affected intestinal lesion to be removed and stapled. The target area is cut at the same time as the adjacent ends are stapled. After removing the affected area, the surgeon typically inserts anvil 130 of instrument 100b into the proximal end of the lumen, proximal of the staple line. This is done by inserting anvil head 132 into an entrance that has been cut into the proximal lumen by the surgeon. In some embodiments, anvil 130 is placed transanally by placing anvil head 132 at the distal end of instrument 100b and inserting instrument 100b through the rectum. The proximal end of the intestine is then tied to anvil shaft 134 using a suture or other conventional tying device and the proximal and distal ends of the intestine are tightened within the gap by closing the gap between anvil 130 and staple cartridge 180

[0177] As shown in FIG. 22A, anvil 130 is positioned within a first section 414 of separated intestinal tissue 142 and housing 151 is positioned with a second section 146 of the intestinal tissue. As shown in FIGS. 22B and 22C, staple pusher 170 is advanced distally such that staples 200 pass through first and second sections 414, 416 and deform against anvil 130 to join and seal the tissue sections 414, 416. At this point, tissue sections 414, 416 are stable and generally do not move relative to each other or instrument 100b. As shown in FIG. 1 ID, knife 166 is then advanced distally to sever tissue structures 414, 416 inwardly from staples 200 to complete the anastomosis.

[0178] Referring now to FIGS. 23-34, another embodiment of surgical instrument 100 that may be used with one of the retractable tip members described herein. Instrument 100c comprises many of the same components as the circular stapling instruments described above. A stapling assembly 120 comprises a housing 151 having a substantially cylindrical main body152 with an internal channel 154 for receiving a cutting element assembly 160, a staple pusher 170 and a staple cartridge 180. Housing 151 couples the stapling assembly 120 to shaft 105. In some embodiments, housing 150 may comprise an inclined surface 153 that tapers inwardly in the proximal direction to accommodate a stapling assembly 120 having a larger diameter than shaft 105.

[0179] Stapling assembly 120 may be removably coupled to shaft 105, or permanently affixed thereto. In certain embodiments, stapling assembly 120 is a disposable component of instrument 120 and may be removably attached to shaft 105. In other embodiments, staple cartridge 180 is a disposable component of instrument and may be removably coupled to staple assembly 120. In other embodiments, the entire instrument 120 is manufactured together and may be either a disposable or reusable instrument.

[0180] In an exemplary embodiment, housing 151 includes one or more keying features within channel 154 that inhibit or prevent rotation of stapler pusher 170 and cutting element assembly 160. In a preferred embodiment, the keying features comprise one or more projections 156 extending into channel 154 that cooperate with slots 172 in stapler pusher 170 (see FIGS. 25A and 25B). In one embodiment, cutting element assembly 160 also includes slots 161 aligned with slots 172 such that projections 156 extend through both sets of slots 161, 172 to inhibit or prevent rotation of stapler pusher 170 and cutting element assembly 160 relative to housing 151. Alternatively, housing 151 may further include additional projections (not shown) that extend into corresponding slots in cutting element assembly 160.

[0181] As shown in FIG. 24, anvil 130 includes an anvil head 132 and an anvil shaft 134. Anvil shaft 134 is removably and slidably securable within internal channel 154 of housing 151. Capturing device 140 is configured to advance and withdraw through and internal bore 158 in housing 151 to translate anvil 130 along a longitudinal axis relative to staple assembly 120 to approximate or un-approximate anvil 130 relative to staple assembly 120. Anvil head 132 includes a tissue contacting surface 136 defining staple forming pockets (not shown) for receiving staples 200, as discussed below in reference to FIGS. 26-28.

[0182] As shown in FIG. 25 A, staple pusher 170 defines a substantially cylindrical shape and is coaxially and slidably disposed within internal channel 154 of housing 151. Staple pusher 170 includes a main body 174 and at least one annular array of distally extending fingers 176 extending from body 174. Each finger 176 is configured to be received within a slot of a staple cartridge 180 to engage staples 200, as discussed above. Staple pusher 170 is configuredto advance relative to housing 151 to engage, drive and eject staples 200 against the staple forming pockets of anvil 130. As shown in FIG 23, fingers 176 of staple pusher 170 are preferably recessed proximally from the distal end of housing 150 to provide room for staple cartridge 180.

[0183] Staple cartridge 180 may include one, two or more than two annular arrays or rows of fingers with staple receiving slots (not shown) for receiving one or more sets of concentric staple arrays 200 (see FIG. 24). Staple cartridge 180 is removably or permanently coupled to staple pusher 170 such that staple pusher 170 may drive staples 200 from cartridge 180 into tissue (discussed in more detail below). In particular, distal fingers 176 of staple pusher 170 are configured to advance into the slots of cartridge 180 to drive staples 200 distally.

[0184] In certain embodiments, staple cartridge 180 comprises an annular main body 182 with circumferential slots 184 that extend between the distal end of an array of distal fingers 176 on staple pusher 170 and the inner surface of housing 151. Slots 184 function to align staples 200 with fingers 176 of staple pusher 170 such that distal movement of staple pusher 170 causes staples 200 to move distally to engage and deform against tissue contacting surface 136 of anvil 130.

[0185] Referring to FIG. 24, cutting element assembly 160 generally comprises an annular pusher 164 and an annular cutting element or knife 166 at the distal end of pusher 164. Pusher 164 is configured to advance relative to housing 151 to drive knife 166 through tissue disposed between anvil 130 and stapling assembly 120.

[0186] Instrument 100c further includes a driver 190 for advancing cutting element assembly 160 and staple pusher 170 towards anvil 130. Driver 190 comprises an internal lumen 198 extending therethrough. Capturing device 140 is configured for advancement through internal lumen 198 to engage and translate anvil 130 towards and away from stapling assembly 120. Driver 190 has a proximal end suitably coupled to an actuation mechanism (not shown) for rotating driver 190 relative to end effector 110. In some embodiments, instrument 100c comprises a wrist assembly (not shown) pivotally coupling end effector 110 with shaft 105. At least a portion of driver 190 is movable through the wrist assembly between shaft 105 and end effector 110. In one such embodiment, the wrist assembly comprises one or more linkages for articulating the end effector around first and second axes, respectively. The first and second axes may be, for example, yaw and pitch axes.

[0187] In embodiments, driver 190 comprises the distal portion described above forengaging the staple and knife pushers and a flexible portion (not shown) that extends through the wrist member when the distal portion is within end effector 110. The flexible portion allows the distal portion to articulate relative to the proximal portion when end effector 110 articulates about the wrist member. The drive member further comprises a proximal portion (not shown) extending through the shaft and configured for coupling to an actuator, such as instrument handle or an external control system. In embodiments, the flexible portion of driver 190 comprises a bendable laser cut hypo tube that extends through shaft 105 of instrument 100c. The hypo tube has sufficiently flexibility to bend as the end effector 110 is rotated relative to shaft 105.

[0188] As shown in FIGS. 23 and 24, driver 190 comprises an elongate rod 191 that includes proximal and distal sets of external threads 192, 194 (with proximal being defined as the direction towards shaft 105). In an exemplary embodiment, distal threads 194 of driver 190 are spaced from proximal threads 192 by a gap 196 (discussed in more detail below).

[0189] Referring again to FIGS. 23 and 26, staple pusher 170 comprises a proximal shaft 175 slidably disposed within channel 154 of housing 151. Shaft 175 includes internal threads 178 configured to cooperate and engage with proximal threads 192 of driver 190 such that rotation of driver 190 causes longitudinal movement of stapler pusher 170. Similarly, cutting element assembly 160 comprises a proximal shaft 168 disposed within central bore 158 of housing 151. Shaft 168 includes internal threads 169 to cooperate and engage with distal threads 194 of driver 190 such that rotation of driver 190 causes longitudinal movement of cutting element assembly 160.

[0190] Referring now to FIGS. 26-28, in an initial position prior to deployment of staples 200 and knife 166, the distal surface of knife 166 is proximally recessed from the distal surface of staple cartridge 180 (see FIGS. 26 and 27). As driver 190 is rotated, it causes both knife pusher 164 and stapler pusher 170 to advance distally. Since knife 166 is proximally recessed from the distal surface of staple cartridge 180, the staples 200 are driven into the tissue and against tissue contacting surface 136 of anvil 130 before knife 166 extends distally of housing 151 (see FIG. 27). Thus, staples 200 are fully formed through the tissue before the knife 166 cuts into the tissue. This ensures that the tissues structures are sealed or attached to each other before the knife 166 cuts through them, ensuring that the tissue structures have not displace relative to each other or instrument 100c between the time the staples are formed and the knife cuts the tissue.

[0191] As shown in FIG. 27, after the staples 200 have been fully formed, internal threads 178 of staple pusher 170 move distally of proximal threads 192 of driver 190 such that they are aligned with gap 196. This causes staple pusher 170 to disengage from driver 190 such that further rotation of driver 190 does not move stapler pusher 170 in the distal direction.

[0192] Referring now to FIG. 28, after the staples 200 have been fully formed in the tissue, driver 190 continues to rotate to advance knife pusher 164 and knife 166 in the distal direction until knife 166 extends beyond the distal end of housing 151 and severs the tissue.

[0193] Referring now to FIGS. 35A-35C, an alternative embodiment of circular stapler lOOd will now be described. In this embodiment, distal threads 194 of driver 190 have a different pitch than proximal threads 192 of driver 190 such that each single rotation of driver 190 moves staple pusher 170 a different distance than knife pusher 164. In addition, this configuration may provide a stronger mechanical advantage to either stapler pusher 170 or knife pusher depending on which thread has a higher thread count per inch. In one embodiment, proximal threads 192 have a shorter distance between adjacent threads, i.e., a higher thread count per inch, than the distance between adjacent threads of distal threads 194. Thus, staple pusher 170 will be provided with a higher mechanical advantage than knife pusher 164. In addition, knife pusher 164 will travel further (and / or faster) than staple pusher 192 for each single rotation of driver 190.

[0194] In an exemplary embodiment, the ratio of the thread count per inch between distal threads 194 and proximal threads 192 is about 1 to 1.25 to about 1 to 2, or about 1 to 1.5. Thus the ratio of the force applied by driver 190 to knife pusher 164 relative to staple pusher 170 is about 1 to 1.25 to about 1 to 2.0, or about 1 to about 1.5.

[0195] As shown in FIG. 35A, in the initial position, the distal surface of knife 166 is recessed further from the distal surface of staple pusher 170 to account for the increased travel distance of knife 166. Rotation of driver 190 causes both pushers to move distally until staples 200 are fully formed (see FIG. 35B). At this point, the distal surface of knife 166 is still proximal of the distal surface of staple assembly 120. In addition, proximal threads 192 of driver 190 have disengaged from 178 internal threads of stapler pusher 170 such that staple pusher 170 no longer advances distally. As shown in FIG. 35C, further rotation of driver 190 causes knife 166 to advance distal of staple assembly 120 to sever tissue between staple assembly 120 and anvil 130.

[0196] Referring now to FIGS. 29A-29D, an alternative embodiment of a circular staplinginstrument 500 will now be described. As shown, instrument 500 includes a staple assembly 502 having a driver 504, a staple pusher 506 and a knife pusher 508 as described above. In this embodiment, driver 504 includes a single set of threads 510 rather than two sets of threads as described with instrument 100c. In addition, driver 504 is disposed laterally outward from staple pusher 506 and knife pusher 508. Staple pusher 506 comprises screw threads 512 on a laterally outward surface of staple pusher 506 and knife pusher 508 comprises threads 514 on a laterally outward surface of knife pusher 508. Threads 512 are positioned proximally of threads 510.

[0197] As shown in FIG. 29A, threads 506 of driver 504 initially engage only the distal threads 510 on staple pusher 506. As driver 504 is rotated, it advances stapler pusher 506 in the distal direction (see FIG. 29B). Once stapler pusher 506 has advanced to the point where staples 330 are formed against anvil 322, threads 310 of driver 304 disengage from the distal threads 512 of staple pusher 506 and driver threads 510 contact threads 514 of knife pusher 508 to advance knife pusher 508 distally (see FIG. 29C). Further rotation of driver 504, then causes distal movement of knife pusher 508 until the knife 520 contacts and severs tissue between anvil 522 and the distal surface of staple assembly 502 (see FIG. 29D).

[0198] Referring now to FIGS. 30A-30D, in this embodiment, an instrument 800 includes a staple assembly 802 having a driver 804, a staple pusher 806 and a knife pusher 808 as described above. In this embodiment, driver 804 includes a single set of threads 810 and is disposed laterally inward from staple pusher 806 and knife pusher 808 (similar to the embodiment shown in FIGS. 23 and 24). Staple pusher 806 comprises screw threads 812 on a laterally inward surface of staple pusher 806 and knife pusher 808 comprises threads 814 on a laterally inward surface of knife pusher 808. Threads 814 are positioned proximally of threads 812.

[0199] As shown in FIG. 30A, threads 810 of driver 804 initially engage only the distal threads 812 on staple pusher 806. As driver 804 is rotated, it advances stapler pusher 806 in the distal direction and threads 810 move proximally (see FIG. 30B). Once stapler pusher 806 has advanced to the point where staples 820 are formed against anvil 822, threads 810 of driver 804 disengage from the distal threads 812 of staple pusher 806 engage the proximal threads 814 of knife pusher 808 (see FIG. 30C). Further rotation of driver 804, then causes distal movement of knife pusher 808 until the knife 830 contacts and severs tissue between anvil 822 and the distal surface of staple assembly 802 (see FIG. 3 ID).

[0200] Referring now to FIGS. 31 A-3 ID, in this embodiment, an instrument 850 includes a staple assembly 852 having a driver (not shown), a staple pusher 856 and a knife pusher 858 as described above. In this embodiment, the driver includes a single set of threads 860 and is disposed laterally inward from staple pusher 856 and laterally outward from knife pusher 858 (i.e., between staple pusher 856 and knife pusher 858). Staple pusher 856 comprises screw threads (not shown) on a laterally inward surface of staple pusher 856 and knife pusher 858 comprises threads (not shown) on a laterally outward surface of knife pusher 858. The knife pusher threads are positioned proximally of the staple pusher threads

[0201] As shown in FIG. 31 A, threads 860 of the driver initially engage only the distal threads on staple pusher 856. As driver 854 is rotated, it advances stapler pusher 856 in the distal direction and threads 860 move proximally (see FIG. 3 IB). Once stapler pusher 856 has advanced to the point where the staples are formed against anvil 870, threads 860 of driver 854 disengage from the distal threads of staple pusher 856 and engage the proximal threads of knife pusher 858 (see FIG. 31C). Further rotation of driver 854, then causes distal movement of knife pusher 858 until the knife 872 contacts and severs tissue between anvil 870 and the distal surface of staple assembly 852 (see FIG. 3 ID).

[0202] Referring now to FIGS. 32-34, another embodiment of a circular stapling instrument 900 will now be described. As shown, instrument 900 comprises a circular stapling assembly 920, an anvil 930 and a capturing device 940 for advancing and retracting anvil 930 relative to stapling assembly 920. Stapling assembly 920 comprises a housing 950 having a substantially cylindrical main body with an internal channel for receiving a cutting element assembly 960, a staple pusher 970 and a staple cartridge 980.

[0203] Similar to the embodiment described previously, anvil 930 includes an anvil head and an anvil shaft. The anvil shaft is insertable into an inner bore of housing 950 and is removably and slidably securable within this bore. Capturing device 940 is configured to translate through the bore to translate anvil 934 along a longitudinal axis relative to staple assembly 920 to approximate or un-approximate anvil 930 relative to staple assembly 920. The anvil head includes a tissue contacting surface defining staple forming pockets (now shown) for receiving the staples, as discussed previously.

[0204] Staple pusher 970 defines a substantially cylindrical shape and is coaxially and slidably disposed within an internal channel of housing 950. Cutting element assembly 960 generally comprises an annular pusher and an annular cutting element or knife. Pusher 964 isconfigured to advance relative to housing 950 to drive the knife through tissue disposed between anvil 930 and staple assembly 920.

[0205] Instrument 900 further includes first and second drivers 990, 992 for advancing cutting element assembly 960 and staple pusher 970, respectively, towards anvil 930. In this embodiment, drivers 990, 992 comprise compressive drive mechanisms configured to advance longitudinally through housing 950 to advance staple pusher 970 and the knife pusher. In an exemplary embodiment, these compressive drive mechanism comprise a bendable laser cut hypo tube that extends through shaft 905 of instrument 900. The hypo tubes have a proximal end (not shown) suitably coupled to an actuator that advances and retracts drivers 990, 992. The hypo tubes may be configured to extend through a wrist (not shown) of the instrument. Therefore, they have sufficiently flexibility to bend as the end effector 910 is rotated relative to shaft 905.

[0206] Referring now to FIG. 32, the distal surface of knife 966 is initially recessed from the distal end of housing 950. In one embodiment, the distal surface of knife 966 is recessed from the distal end of staples 200 and substantially aligned with the distal surface of staple pusher 970. In this embodiment, drivers 990, 992 may be configured to simultaneously drive staple pusher and knife pusher such that the staples 200 contact anvil 930 before knife 966 cuts the tissue. Thus, staples 200 are fully formed through the tissue before the knife 966 cuts into the tissue. This ensures that the tissues structures are sealed or attached to each other before the knife 966 cuts through them, ensuring that the tissue structures have not moved relative to each other or instrument 900 between the time the staples are formed and the knife cuts the tissue.

[0207] In an alternative embodiment, the distal surface of knife 966 may, or may not, be recessed from the distal surface of staple assembly 920. In this embodiment, first and second drivers 990, 992 advance the knife and staple pushers sequentially. Specifically, first driver 990 advances staple pusher until the staples engage anvil 930 and are fully formed through the tissue. After that occurs, second driver 992 advances knife pusher to drive knife 966 through the tissue. Alternatively, second drive 992 may advance staple pusher 970 at a faster rate than knife pusher 960 (even if they start at the same relative location) such that the staples contact the tissue before the knife.

[0208] Referring now to FIGS. 36A-36C, another embodiment of an anvil 1130 for a circular stapler includes an anvil head 1132 and an anvil shaft 1134. Anvil shaft 1134 isinsertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. The capturing device (not shown) is configured to advance and withdraw through this internal channel to translate anvil 1130 along a longitudinal axis relative to staple assembly 120 to approximate or un-approximate anvil 1130 relative to staple assembly 120.

[0209] In this embodiment, anvil head 1132 comprises a central component 1140 and first and second lateral components 1142, 1144. In one embodiment, central component 1140 forms the central portion of a generally circular head 1132 and lateral components 1142, 1144 each comprise a semi-circular outer portion of the circular head 1132. In an exemplary embodiment, lateral components 1142, 1144 generally have the same size and shape, although it will be understood that one of the lateral components may be larger than the other.

[0210] As shown in FIG. 36B, central component 1140 is pivotally coupled to shaft 1134 such that it is movable from a collapsed configuration, wherein central component 1140 extends in a direction transverse, or substantially parallel to. shaft 1134 (FIG. 36B), to an expanded configuration, wherein central component 1140 extends in a direction traverse to, or substantially perpendicular to. shaft 1134 (FIG. 36C). In addition, first and second lateral components 1142, 1144 are pivotally coupled to central component 1140 such that they are movable between a collapsed configuration (FIG. 36B), wherein they are folded together towards central component 1140 and extend substantially perpendicular to central component 1140, to an expanded configuration, wherein lateral components 1142, 1144 extends substantially parallel to central component 140 to form an anvil suitable for cooperation with staple assembly 120 (FIG. 36C).

[0211] Anvil 1130 is configured such that it has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1134) in the collapsed configuration than in the expanded configuration. Lateral dimension is herein defined as the radial distance from the longitudinal axis of shaft to the furthest radial surface or point of the anvil 1130 from the longitudinal axis. In certain embodiments, anvil 1130 has a lateral dimension (or diameter in certain embodiments) of less than about 14 mm in the collapsed configuration such that anvil 1130 may be advanced through a cannula or other percutaneous entry point in the patient. Anvil 1130 may have a lateral dimension (or diameter) of at least about 20 mm or at least about 25 mm, or about 21 to about 33 mm in the expanded configuration, although it will be recognized that the dimensions of anvil 1130 may vary depending on the surgical procedure and the size of the percutaneous entry point into the patient.

[0212] Anvil head 1132 is configured such that when central portion 1140 and lateral portions 1142, 1144 are in the expanded configuration, they form a substantially circular disc. The disc has sufficient rigidity to withstand the forces of clamping and / or driving staples through the tissue against the staple pockets on the proximal surface of head 1132. In addition, the staples pockets are aligned with the circumferential staples that are driven against these pockets by staple assembly 120.

[0213] Anvil 1130 may further include one or more driver(s) (not shown) within shaft 1134 that have a distal end portion coupled to the pivot joints between shaft 1134 and central component 1140 and / or the pivot joints between lateral components 1142, 1144 and central component 1140 for pivoting or rotating these components relative to each other. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The driver(s) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0214] Referring now to FIGS. 37 and 38A-38C, another embodiment of an anvil 1200 includes an anvil head 1202 and an anvil shaft 1204. Anvil shaft 1204 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. The capturing device (not shown) is configured to advance and withdraw through this internal channel to translate anvil 1200 along a longitudinal axis relative to staple assembly 120 to approximate or un-approximate anvil 1200 relative to staple assembly 120. Anvil head 1202 is movable between a collapsed or substantially linear configuration (see FIGS. 37 and 38C) and an expanded or circular disc-shaped configuration (see FIG. 38A). Head 1202 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1204) in the linear configuration than in the circular configuration.

[0215] Anvil head 1202 comprises one or more linkages that are movable between the linear and circular configurations. In one embodiment, head 1202 comprises first, second and third linkages 1206, 1208, 1210. Each linkage comprises an outer surface 1217 and an inner surface 1218 that form at least a partial sector of a circle (or a sector of a circle having a hollow central area). All of the linkages are designed to pivot towards each other such that the linkages form a circular disc 1240 (see FIG. 38A). Each linkage 1206, 1208, 2110 further comprises a tissue contacting surface defining staple forming pockets (not shown) for receiving staples 1200 (see FIGS. 11 A-l ID discussed above).

[0216] In an exemplary embodiment, each linkage 1206, 1208, 1210 is substantially thesame shape (i.e., sector) and thus forms one-third of the circular disc 1240 (see FIG. 38A), although it will be recognized that each linkage may have different shapes. In addition, it will be recognized that anvil head 1202 may comprise 2 linkages or 4 or more linkages. In addition, it should be recognized that certain of the linkages may be larger than the other linkages. For example, linkage 1206 may be semicircular, i.e., forming one-half of the disc 1240, while the remaining half is formed of 2 or more linkages. The staple forming pockets are circumferentially arranged on each linkage such that they align with staple bays in staple assembly 120 when the linkages are formed into disc 1240.

[0217] First linkage 1206 includes a pin 1224 pivotally coupled to a universal joint or disc 1212 on a distal end portion 1240 of anvil shaft 1204. Second linkage 1208 is pivotally coupled to first and third linkages 1206, 1210 with connecting pins 1214, 1216, respectively. Each linkage 1206, 1208, 1210 has a distance or radius between inner and outer surfaces 1217, 1218 that may be less than the overall radius of the circular disc when the linkages have formed together. Thus, as shown in FIG. 38 A, the linkages form a central opening 1232 in the expanded configuration. This configuration reduces the overall size of the linkages, which facilitates the deployment process.

[0218] In one embodiment, disc 1212 of anvil shaft 1204 is a universal joint configured to transmit rotary power from shaft 1204 or an actuator within shaft 1204. Disc 1212 is rotatably coupled to distal end portion 1240 of shaft 1204 at pin 1222. Disc 1212 may be rotatable relative to shaft 1204 such that, for example, counterclockwise (or clockwise) rotation of disc 1212 causes linkage 1206 to rotate in a clockwise (or counterclockwise) direction. This rotation further causes linkage 1208 to rotate in a clockwise direction which, in turn causes linkage 1210 to rotate in the same direction until the side surfaces of each linkage contact each other to form the circular disc 1240 (see FIGS. 38A-38C).

[0219] Disc 1212 is also configured to pivot between a first configuration, wherein disc 1212 is substantially parallel to shaft 1204, and a second configuration, wherein disc 1212 is transverse to shaft 1204, or preferably perpendicular to shaft 1204. Disc 1212 is coupled to first linkage 1206 such that this rotation, in turn, rotates circular disc 1240 until it is substantially perpendicular to anvil shaft 1204 and presents the tissue contacting surface in the proximal direction for receiving staples from staple assembly 120.

[0220] In use, disc 1212 and that attached linkages 1206, 1208, 1210 first rotate about pin 1222 until they are substantially perpendicular to shaft 1204. Then, linkages 1206, 1208, 1210sequentially rotate about their connecting pins 1224, 1214 and 1216 until they each contact disc 1212 to form the overall circular disc 1240.

[0221] Anvil 1200 may further include one or more driver(s) (not shown) within shaft 1204 that has a distal end portion coupled to joint 1212 for rotating and / or pivoting joint 1212. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The driver(s) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0222] Referring now to FIGS. 39A and 39B, another embodiment of an anvil 1300 includes an anvil head 1304 and an anvil shaft 1302. As in previous embodiments, anvil shaft 1302 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1304 comprises one or more linkages 1306, 1308 that are movable between linear and circular configurations. Each linkage comprises an outer surface 1316 and an inner surface 1318 that form a sector of a circle. All of the linkages are designed to pivot towards each other such that the linkages form a circular disc (similar to disc 1240 in FIG. 38 A). Each linkage further comprises a tissue contacting surface defining staple forming pockets (not shown) for receiving staples 200.

[0223] In an exemplary embodiment, anvil head 1302 comprises four linkages that are substantially the same shape (i.e., a partial sector of a circle) and thus form one-fourth of the circular disc, although it will be recognized that each linkage may have different shapes. In addition, it will be recognized that anvil head 1302 may comprise 2, linkages, 3 linkages or 5 or more linkages. For example, FIG. 39B illustrates an embodiment with 2 linkages 1306, 1308 that each comprise a semicircle. In addition, it should be recognized that certain of the linkages may be larger than the other linkages. For example, linkage 1306 may be a semicircular, forming one-half of the discs, while the remaining half is formed of 2 or more linkages.

[0224] Linkages 1306, 1308 are pivotally coupled to each other at a joint 1340, 1342 on their side surfaces. The proximal linkage 1306 is also pivotally coupled to a bar or rod 1320 at a joint 1330. Bar 1320 is, in turn, pivotally coupled to a head 1322 of a distal end portion 1326 of shaft 1302 by a joint 1332. Distal end portion 1326 is, in turn, is pivotally coupled to the remainder of shaft 1302 by a hinge or pin 1324 that extends through a channel (not shown) in shaft 1302 such that distal end portion 1326 may pivot between a substantially parallel orientation relative to shaft 1304 (see FIG. 39A) to a substantially perpendicular orientation(see FIG. 39B).

[0225] In use, distal end portion 1326 rotates about pin 1332 into a substantially perpendicular orientation relative to shaft 1302 (see FIG. 39B). Then, the various linkages 1306, 1308 rotate about head 1322 until they form the circular disc that presents the tissue contacting surface in the proximal direction for receiving staples from staple assembly 120.

[0226] Anvil 1300 may further include one or more driver(s) (not shown) within shaft 1304 that has a distal end portion coupled to head 1322 for rotating and / or pivoting head 1322. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The driver(s) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0227] Referring now to FIGS. 40A and 40B, another embodiment of an anvil 1350 includes an anvil head 1352 and an anvil shaft 1354. Similar to previous embodiments, anvil shaft 1354 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1352 is movable between a collapsed or stacked configuration (FIG. 40A) and an expanded or circular disc-shaped configuration (FIG. 40B). Head 1352 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1354) in the stacked configuration than in the circular configuration.

[0228] In this embodiment, anvil head 1352 comprises one or more linkages that are movable between “stacked” and “unstacked” configurations. In one embodiment, head 1352 comprises first, second, third and fourth linkages 1356, 1358, 1360, 1362. Each linkage comprises an outer surface and an inner surface that form a sector of a circle. All of the linkages are designed to move from a stacked configuration (FIG. 40A) to an unstacked configuration such that the linkages form a circular disc (see FIG. 40B). The linkages are substantially aligned with the longitudinal axis of shaft 1354 in the stacked configuration. Anvil 1350 may further include one or more driver(s) (not shown) within shaft 1354 having a distal end portion coupled to a joint or linkage at the distal end of shaft 1354 for rotating and / or pivoting linkages 1356, 1358, 1360, 1362. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The driver(s) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0229] As shown in FIG. 40B, in the stacked configuration, each linkage comprises proximal and distal surfaces 1382, 1380. The proximal surfaces 1382 contain staple pockets(not shown) for receiving staples from staple assembly 120. In this configuration, the proximal surface 1382 of linkage 1356 faces anvil shaft 1354 and may be in contact with shaft 1354. The proximal surface 1382 of linkage 1358 faces the distal surface 1380 of linkage 1360 and may be in contact with this surface (and so on for each linkage in the stack).

[0230] Each linkage 1356, 1358, 1360, 1362 has a distance or radius between their inner and outer surfaces that may be less than the overall radius of the circular disc when the linkages have formed together. Thus, as shown in FIG. 40B, the linkages form a central opening 1370 in the expanded configuration. This configuration reduces the overall size of the linkages, which facilitates the deployment process.

[0231] In an exemplary embodiment, linkages 1356, 1358, 1360, 1362 are substantially the same shape (i.e., sector) and thus form one-fourth of the circular disc, although it will be recognized that each linkage may have different shapes. In addition, it will be recognized that anvil head 1352 may comprise 2 or 3 linkages or 5 or more linkages. In addition, it should be recognized that certain of the linkages may be larger than the other linkages. For example, linkage 356 may be a semicircular, forming one-half of the discs, while the remaining half is formed of 2 or more linkages.

[0232] Referring now to FIGS. 41A, 41B and 42A-42C, another embodiment of an anvil 1400 includes an anvil head 1402 and an anvil shaft 1404. Similar to previous embodiments, anvil shaft 1404 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1402 is movable between a collapsed or folded configuration (see FIG. 42A) and an expanded or dome-shaped configuration (see FIG. 42C). Head 1402 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1404) in the collapsed configuration than in the expanded configuration.

[0233] As shown in FIGS. 42A-42C, anvil head 1402 comprises a plurality of leaves or petals 1406 coupled to each other such that the petals 1406 overlap with each other in the folded configuration. Upon expansion, petals 1406 are configured to form a substantially domed or umbrella shape with a convex outer surface 1440 having an apex 1442 and a concave inner surface 1436 (see FIGS. 41A and 41B). Apex 1442 may be coupled to a distal end portion of shaft 1404. Alternatively, petals 1406 may be configured to expand further such that anvil head 1402 has a substantially flat or circular disc shape in the expanded configuration (similar to previous embodiments). Head 1402 may include at least two petals 1406, or three or more petals 1406.

[0234] One or more of the petals 1406 (or all of the pedals) comprise a tissue contacting surface 1436 that comprises staple forming pockets (not shown) for receiving staples from staple assembly 120. The petals 1406 are configured such that, in the expanded configuration, the staple pockets are configured to align with the staples in staple assembly 120. In certain embodiments, each of the petals 1406 comprises one or more staple forming pockets. In other embodiments, the staple forming pockets may alternate between pedals 1406 such that, for example, one pedal may contain a staple forming pocket while its adjacent pedals do not contain a staple forming pocket.

[0235] In this embodiment, petals 1406 are designed to overlap with each other in both the expanded and collapsed or folded configurations. Thus, in the expanded configuration, petals 406 overlap with each other to provide mutual support and rigidity to anvil head 1402 such that it can resist the forces of the stapling operation. Anvil 1400 may further include a driver (not shown) within shaft 1404 that has a distal end portion coupled to head 1402 for expanding and collapsing pedals 1406. For example, anvil head 1402 may include one or more rigid elements coupled to pedals 1406 designed to telescope or move radially outward to push pedals outward and expand head 1402. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The actuator may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0236] Referring now to FIGS. 43 A and 43B, another embodiment of an anvil 1500 includes an anvil head 1502 and an anvil shaft 1504. As with previous embodiments, anvil shaft 1504 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1502 is movable between a collapsed or folded configuration (see FIG. 43B) and an expanded or dome-shaped configuration (see FIG. 43 A). Head 1502 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1504) in the folded configuration than in the dome-shaped configuration.

[0237] Anvil head 1502 comprises a plurality leaves or petals 1506 coupled to each other such that the petals 1506 overlap with each other in the folded configuration. Upon expansion, petals 1506 are configured to form a substantially domed or umbrella shape with a convex outer surface 1508 and a concave inner surface (not shown). Alternatively, petals 1506 may be configured to expand further such that anvil head 1502 has a substantially flat or circular disc shape in the expanded configuration. Head 1502 may include at least two petals 1506, orthree or more petals 1506.

[0238] One or more of the petals 1506 (or all of the pedals) have a tissue contacting surface comprising one or more staple forming pockets (not shown) for receiving staples from the staple assembly 120. The petals 1506 are configured such that, in the expanded configuration, the staple pockets are configured to align with the staples in staple assembly 120. In certain embodiments, each of the petals 1506 comprises one or more staple forming pockets. In other embodiments, the staple forming pockets may alternate between pedals 1506 such that, for example, one pedal may contain a staple forming pocket while its adjacent pedals do not contain a staple forming pocket.

[0239] Anvil head 1502 further comprises one or more substantially rigid elements or rods 1510 extending substantially from a proximal surface edge 1512 to a central portion or apex 1514 ofhead 1502. Rods 1510 are configured to expand outward with petals 1506 and provide stability and rigidity to head 1502 in the expanded configuration. Rods 1510 may include one or more ridges or other surface features thereon to provide additional stability to head 1502 as it is expanded. Rods 1510 are configured to pivot at apex 1514 and proximal surface 1512 to allow transformation of anvil head 1502 between the expanded and collapsed configurations.

[0240] In some embodiments, anvil head 1502 may further include one or more cables extending around head 1502 to transition the head between the collapsed and expanded configurations. In one such embodiment, head 1502 comprise a lower cable 1530 and an upper cable 1532. Lower cable 1530 is disposed in a proximal region of pedals 1506 near proximal surface 1512 and upper cable 1532 is disposed in a distal region of head 1502 near apex 1514. Cables 1530, 1532 are coupled to one or more driver(s) (not shown) that extend through shaft 1504 of anvil 1500 and are configured to tension cables 1530, 1532 to expand anvil head 1502 into the umbrella or dome shape. The driver(s) (not shown) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0241] Referring now to FIGS. 44A-44C, another embodiment of an anvil 1600 includes an anvil head 1602 and an anvil shaft 1604. Similar to previous embodiments, anvil shaft 1604 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1602 is movable between a collapsed or folded configuration (see FIG. 44A) and an expanded or dome-shaped configuration (see FIGS. 44B and 44C). Head 1602 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1604) in the collapsed configuration than in the expanded configuration.

[0242] As shown in FIG. 44A, anvil head 1602 comprises a plurality leaves or petals 1606 coupled to each other such that the petals 1606 overlap with each other in the collapsed configuration. Upon expansion, petals 1606 are configured to form a substantially domed or umbrella shape with a convex outer surface 1608 and a concave inner surface 1612. Alternatively, petals 1606 may be configured to expand further such that anvil head 1602 has a substantially flat or circular disc shape in the expanded configuration. Head 1602 may include at least two petals 1606, or three or more petals 1606.

[0243] One or more of the petals 1606 (or all of the pedals) comprise a tissue contacting surface 1636 defining staple forming pockets (not shown) for receiving staples 200. The petals 1606 are configured such that, in the expanded configuration, the staple pockets are configured to align with the staples in staple assembly 120 (i.e., such that the staple legs or tines align with the staple bays or pockets so that the staples form properly. In certain embodiments, each of the petals 1606 comprises one or more staple forming pockets. In other embodiments, the staple forming pockets may alternate between pedals 1606 such that, for example, one pedal may contain a staple forming pocket while its adjacent pedals do not contain a staple forming pocket.

[0244] Similar to previous embodiments, anvil 1600 may further include one or more driver(s) (not shown) within shaft 1604 that each have a distal end portion coupled to head 1602 for expanding and collapsing pedals 1606. For example, anvil head 1602 may include one or more rigid elements coupled to pedals 1606 designed to telescope or move radially outward to push pedals outward and expand head 1602. Alternatively, the driver(s) may be disposed within the circular stapler assembly 120, or within a separate anvil delivery instrument (not shown). The driver(s) may have a proximal end coupled to a suitable actuation mechanism (discussed in more detail below).

[0245] In this embodiment, anvil 1600 further comprises an expandable element 1610, such as a balloon or the like, configured to expand and apply pressure to outer surface 1608 of head 1602. This ensures that the staple pocket plane is capable of resisting the force from the clamping of tissue and then from the firing and cutting forces. Balloon 1610 may be inflated in any suitable manner, such as fluid inflation (e.g., air or other gases, or fluid), chemical inflation or (e.g., mixing certain materials together to form an expanding gas within the balloon) and the like. In one embodiment, balloon 1610 comprises a proximal end configured for coupling to a suitable fluid source, such as carbon dioxide, saline or the like. The fluidsource may be any suitable source, such as a carbon dioxide tank under pressure, a syringe filled with gas to fluid, such as saline, or a source of insufflation.

[0246] Referring now to FIGS. 45 A, 45B and 46A-46C, another embodiment of an anvil 1700 includes an anvil head 1702 and an anvil shaft 1704. Anvil shaft 1704 is insertable into an internal channel of staple assembly 120 and is removably and slidably securable therein. Anvil head 1702 is movable between a collapsed configuration (see FIG. 46A) and an expanded configuration (see FIG 46C). Head 1702 has a smaller cross-sectional area or lateral dimension (relative to the longitudinal axis of shaft 1704) in the collapsed configuration than in the expanded configuration.

[0247] In this embodiment, anvil head 1702 comprises an expandable element 1710, such as a balloon or the like. Balloon 1710 may be inflated in any suitable manner, such as fluid inflation (e.g., air or other gases, or fluid), chemical inflation or (e.g., mixing certain materials together to form an expanding gas within the balloon) and the like. In one embodiment, balloon 1710 comprises a proximal end configured for coupling to a suitable fluid source, such as carbon dioxide, saline or the like. The fluid source may be any suitable source, such as a carbon dioxide tank under pressure, a syringe filled with gas to fluid, such as saline, or a source of insufflation.

[0248] Anvil 1700 further comprises an annular film 1720 having an inner surface 1722 with a larger diameter than shaft 1704. Film 1720 includes a tissue contacting surface 7136 defining staple forming pockets (not shown) for receiving staples 200. Film 1720 preferably comprises any suitable material, such as metal or a hard polymer, having sufficient stiffness to configured to resist the forces applied by clamping of tissue and then from the firing and cutting forces of the stapler assembly.

[0249] In one embodiment, film 1720 is coupled to a proximal surface of balloon 1710 (see FIGS. 46A-46C). Film 1720 may be configured to expand radially outward as the balloon 1710 is inflated such that, in the expanded configuration, the staple pockets are configured to align with the staples in staple assembly 120 (i.e., such that the staple legs or tines align with the staple bays or pockets so that the staples form properly). In another embodiment, film 1720 is configured to advance along anvil shaft 1704 in the distal direction after balloon 1710 has been expanded. In this embodiment, film 1720 may be configured to expand via a separate actuator after film 1720 has been advanced in contact with balloon 1710. Balloon 1710 is configured to apply pressure to a distal surface of film 1720 to ensure that film 1720 resists theforces applied during the stapling operation.

[0250] The proximal end portion of the anvils described above are operatively connected to one or more drivers or actuation mechanisms (not shown), although as those skilled in the art reading this description will appreciate, components of the drivers may extend into, and / or pass through the anvil shafts and / or the stapler instrument 100. In embodiments, the anvils and / or instrument 100 will include a proximal handle (not shown) for actuating the drivers that move the anvils between the collapsed and expanded configurations, and, in some embodiments, for controlling the orientation and movement of the anvils. Alternatively, the system may include an anvil delivery instrument that includes one or more drivers for expanding and collapsing the anvils.

[0251] Referring now to FIG. 47, an anvil delivery instrument 1800 includes an elongate shaft 1802 sized to advance through a suitable percutaneous penetration in the patient, such as a trocar, cannular and the like. In certain embodiments, shaft 1802 has an outer dimension of less than about 14 mm, although it will be recognized that the dimensions of shaft 1802 may vary depending on the surgical procedure and the size of the percutaneous entry point into the patient.

[0252] Instrument 1800 further includes first and second jaws 1804, 1806, that are movable between open and closed positions relative to each other. In certain embodiments, second jaw 1806 is a movable jaw configured to move from an open position to a closed position relative to first jaw 1804. In other embodiments, first jaw 1804 is a movable jaw configured to move between open and closed positions relative to second jaw 1806. In the exemplary embodiment, both jaws 1804, 1806 are movable relative to each other.

[0253] As shown in FIG. 47, jaws 1804, 1806 preferably pivot about a hinge that may include a pivot pin 1810 extending through a slot (not shown) in each of the jaws 1804, 1806. Instrument 1800 includes a driver (not shown) within shaft 1802 that opens and closes jaws 1804, 1806 about pivot pin 1810. Jaws 1804, 1806 may be opened and closed may any suitable mechanisms including, but not limited to, those described in any of the publications incorporated herein by reference. First and second jaws 1804, 1806 may also be capable of articulating together relative to shaft 1802 about an axis substantially perpendicular to the longitudinal axis (e.g., the yaw or pitch axes). In these embodiments, instrument 1800 may further include a wrist assembly (not shown) that allows jaws 1804, 1806 to articulate relative to shaft 1802.

[0254] In an exemplary embodiment, jaws 1804, 1806 are configured to move into a substantially parallel position with each other in the closed position (as shown in FIG. 51). Jaws 1804, 1806 are preferably sized such that each jaw contacts and grips onto an outer surface of anvil shaft 1134 in the closed position. This configuration provides a stronger grip on shaft 1134 and inhibits the shaft from watermelon seeding from the jaws, as is the case with typical prior art instruments that do not close in a substantially parallel orientation.

[0255] In an exemplary embodiment, jaw 1804 includes a jaw grasping portion 1840 and a proximal support 1842. Proximal support 1842 extends downward towards a jaw grasping portion 1844 of jaw 1806 and is coupled thereto by pivot pin 1810. Proximal support 1842 is sized and shaped such that pivot pin 1810 is located closer to jaw grasping portion 1844 of jaw 1806 than jaw grasping portion 1842 of jaw 1804. Thus, pin 1810 and grasping portion 1842 are disposed on one side of a central longitudinal axis 1850 of shaft 1802 and jaw grasping portion 1840 is located on the other side of longitudinal axis 1850. This provides an asymmetrical location for the hinge or pivot point between jaws 1804, 1806 such that the jaws can be position in a closed position around shaft 1134 of anvil 1130 with substantially parallel surfaces facing shaft 1134.

[0256] Referring again to FIG. 47, delivery instrument 1800 includes a driver for moving anvil head 1132 between the collapsed and expanded configurations. In one embodiment, the driver comprises a rod 1820 that extends through shaft 1802. Rod 1820 includes a distal end portion 1822 configured to extend at least partially through jaws 1804, 1806. In one embodiment, rod 1820 is sized and configured to extend through an internal lumen (not shown) in anvil shaft 1134 and is configured for distal advancement through shaft 1134 to engage anvil head 1132 (see FIGS. 24 and 25). Rod 1820 includes an engagement mechanism (not shown) on distal end portion 1822 that cooperates with an engagement mechanism on anvil head 1134 to move anvil head 1132 between the collapsed and expanded configurations.

[0257] In one embodiment, rod 1820 includes a rotatable element (not shown) configured to rotate relative to rod 1820. In another embodiment, the entire rod 1820 is configured to rotate relative to shaft 1802. Rotation of rod 1820 or the rotation element causes central component 1140 of anvil head 1132 to pivot about a hinge on anvil shaft 1134 between the collapsed and expanded configurations. In addition, rotation of rod 1820 causes lateral components 1142, 1144 to pivot about hinges between lateral components 1142, 1414 and central component 1140. In an alternative embodiment, instrument 1800 includes a seconddriver on rod 1820 or on another element of instrument 1800 that causes lateral components 1142, 1144 to pivot relative to central component 1140 (i.e., movement of anvil head 1132 into the collapsed configuration may be caused by a single or multiple drivers in instrument 1800).

[0258] In another embodiment, distal end portion 1822 of rod 1820 is configured to actuate anvil head 1132 through a push-pull mechanism. For example, longitudinal movement of rod 1820 relative to instrument 1800 causes central component 1140 to pivot about anvil shaft 1134 and / or lateral components 1142, 1144 to pivot about central component 1140.

[0259] The surgical instruments described herein may be coupled to a proximal control system that monitors and controls the drive member or actuator that proximally retracts the tip member from distal end of the instrument. For example, the control system may monitor and control the actuator or drive member 250 to proximally withdraw tip member 150 after staple assembly 120 has been navigated to the target site in the bowel. This control system may be a manual control system with user interfaces that allow the user to control each of the functions of the instrument, or it may be an automatic control system that monitors and controls these functions. In some embodiments, the control system is a combination of manual and automatic that allows the user to adjust or control certain functions, while automatically limiting those functions within certain ranges or parameters.

[0260] With reference to Fig. 52, an exemplary embodiment of a teleoperated surgical instrument 500 that may support a previously described instrument is depicted. As shown, the instrument 500 generally includes a proximal housing 510 at its proximal end and coupled to shaft 520 of the instrument and a circular stapling assembly 530 at the distal end of shaft 520. Proximal housing 510 may include an instrument memory or storage device (not shown). The memory can perform a number of functions when the instrument is loaded on a manipulator arm (not shown) of a robotic control system. For example, the memory can provide a signal verifying that the instrument is compatible with that particular surgical system. Additionally, the memory may identify the instrument and end effector type (whether it is a scalpel, a needle grasper, j aws, scissors, a clip applier, an electrocautery blade, or the like) to the surgical system so that the system can reconfigure its programming to take full advantage of the instrument's specialized capabilities. As further discussed below, the memory may include specifics on the architecture of the instrument, and include particular values that should be employed in control algorithms, such as tool compliance and gain values.

[0261] Proximal housing 510 also may include a force / torque drive transmissionmechanism (not shown) for receiving output from the motors of the manipulator arm. The force / torque drive transmission mechanism transmits the output from the motors to an end effector 530 of the instrument through an instrument shaft 520 mounted to the transmission mechanism. Exemplary surgical robotic instruments, instrument / manipulator arm interface structures, and data transfer between the instruments and servomechanism is more fully described in U.S. Pat. No. 6,331,181, the full disclosure of which is incorporated herein by reference.

[0262] In certain embodiments, the instrument may include sensors (not shown) for detecting a location of the engagement elements. The sensors may include any suitable sensors for detecting location, force and / or torque. In one embodiment, the sensors include fiber optic bend sensors, such as Fiber Bragg Gratings (FBG) for providing strain measurements in the tip member, drive member, staple assembly and / or other components of the surgical instrument. Various systems and methods for monitoring the shape and relative position of an optical fiber in three dimensions are described in U.S. patent application publication no. 2006 / 0013523, filed on Jul. 13, 2005, and U.S. Pat. No. 6,389,187, filed on Jun. 17, 1998, the completed disclosures of which are incorporated herein by reference for all purposes.

[0263] As noted above, the present surgical instruments may be employed in a robotic teleoperated surgical system. FIG. 53 illustrates, as an example, a top view of an operating room employing a robotic surgical system. The robotic surgical system in this case is a robotic surgical system 600 including a Console (“C”) utilized by a Surgeon (“S”) while performing a minimally invasive diagnostic or surgical procedure, usually with assistance from one or more Assistants (“A”), on a Patient (“P”) who is lying down on an Operating table (“O”).

[0264] The servomechanism used for telesurgery will often accept input from two master controllers (one for each of the surgeon's hands) and may include two or more robotic arms. A surgical instrument is mounted on each of the robotic arms. Operative communication between master controllers and associated robotic arm and instrument assemblies is typically achieved through a control system. The control system typically includes at least one processor that relays input commands from the master controllers to the associated robotic arm and instrument assemblies and back in the case of, for example, force feedback or the like. One example of a robotic surgical system is the DA VINCI™ system commercialized by Intuitive Surgical, Inc. of Sunnyvale, California.

[0265] A variety of structural arrangements have been used to support the surgicalinstrument at the surgical site during robotic surgery. The driven linkage or "slave" is often called a robotic surgical manipulator, and exemplary linkage arrangements for use as a robotic surgical manipulator during minimally invasive robotic surgery are described in U.S. Pat. Nos. 7,594,912, 6,758,843, 6,246,200, and 5,800,423, the full disclosures of which are incorporated herein by reference in their entirety for all purposes. These linkages often manipulate an instrument holder to which an instrument having a shaft is mounted. Such a manipulator structure can include a parallelogram linkage portion that generates motion of the instrument holder that is limited to rotation about a pitch axis that intersects a remote center of manipulation located along the length of the instrument shaft. Such a manipulator structure can also include a yaw joint that generates motion of the instrument holder that is limited to rotation about a yaw axis that is perpendicular to the pitch axis and that also intersects the remote center of manipulation. By aligning the remote center of manipulation with the incision point to the internal surgical site (for example, with a trocar or cannula at an abdominal wall during laparoscopic surgery), an end effector of the surgical instrument can be positioned safely by moving the proximal end of the shaft using the manipulator linkage without imposing potentially hazardous forces against the abdominal wall. Alternative manipulator structures are described, for example, in U.S. Pat. Nos. 6,702,805, 6,676,669, 5,855,583, 5,808,665, 5,445,166, and 5,184,601, the full disclosures of which are incorporated herein by reference in their entirety for all purposes.

[0266] During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors that perform various functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting tissue, or the like, in response to manipulation of the master input devices. Manipulation and control of these end effectors is a particularly beneficial aspect of robotic surgical systems. For this reason, it is desirable to provide surgical tools that include mechanisms that provide two or three degrees of rotational movement of an end effector to mimic the natural action of a surgeon's wrist. Such mechanisms should be appropriately sized for use in a minimally invasive procedure and relatively simple in design to reduce possible points of failure. In addition, such mechanisms should provide an adequate range of motion to allow the end effector to be manipulated in a wide variety of positions.

[0267] The Console includes a monitor 604 for displaying an image of a surgical site to the Surgeon, left and right manipulatable control devices 608 and 609, a foot pedal 605, and aprocessor 602. The control devices 608 and 609 may include any one or more of a variety of input devices such as joysticks, gloves, trigger-guns, hand-operated controllers, or the like. The processor 602 may be a dedicated computer that may be integrated into the Console or positioned next to it.

[0268] The Surgeon performs a minimally invasive surgical procedure by manipulating the control devices 608 and 609 (also referred to herein as “master manipulators”) so that the processor 602 causes their respectively associated robotic arm assemblies, 628 and 629, (also referred to herein as “slave manipulators”) to manipulate their respective removably coupled surgical instruments 638 and 639 (also referred to herein as “tools”) accordingly, while the Surgeon views the surgical site in 3-D on the Console monitor 604 as it is captured by a stereoscopic endoscope 640.

[0269] Each of the tools 638 and 639, as well as the endoscope 640, may be inserted through a cannula or other tool guide (not shown) into the Patient so as to extend down to the surgical site through a corresponding minimally invasive incision such as incision 666. Each of the robotic arms is conventionally formed of links, such as link 662, which are coupled together and manipulated through motor controlled or active joints, such as joint 663.

[0270] The number of surgical tools used at one time and consequently, the number of robotic arms being used in the system 600 will generally depend on the diagnostic or surgical procedure and the space constraints within the operating room, among other factors. If it is necessary to change one or more of the tools being used during a procedure, the Assistant may remove the tool no longer being used from its robotic arm, and replace it with another tool 331 from a Tray (“T”) in the operating room.

[0271] The monitor 604 may be positioned near the Surgeon's hands so that it will display a projected image that is oriented so that the Surgeon feels that he or she is actually looking directly down onto the operating site. To that end, images of the tools 638 and 639 may appear to be located substantially where the Surgeon's hands are located.

[0272] The processor 602 performs various functions in the system 600. One function that it performs is to translate and transfer the mechanical motion of control devices 608 and 609 to their respective robotic arms 628 and 629 through control signals overbus 610 so that the Surgeon can effectively manipulate their respective tools 638 and 639. Another important function is to implement various control system processes as described herein.

[0273] Robotic surgery systems and methods are further described in U.S. Pat. No. 5,797,900, filed on May 16, 1997, issued on Aug. 25, 1998, U.S. Pat. No. 6,132,368, filed on Nov. 21, 1997, issued on Oct. 17, 2000, U.S. Pat. No. 6,331,181, filed on Oct. 15, 1999, issued on Dec. 18, 2001, U.S. Pat. No. 6,441,577, filed on Apr. 3, 2001, issued on Aug. 27, 2002, U.S. Pat. No. 6,902,560, filed on Jan. 6, 2004, issued on Jun. 7, 2005, U.S. Pat. No. 6,936,042, filed on Apr. 16, 2002, issued on Aug. 30, 2005, and U.S. Pat. No. 6,994,703, filed on Dec. 4, 2002, issued on Feb. 7, 2006, the full disclosures of which are incorporated herein by reference for all purposes. A suitable robotic surgical system currently in use is the da Vinci S Surgical System by Intuitive Surgical, Inc.

[0274] FIG. 54 illustrates, as an example, a side view of a simplified (not necessarily in proportion or complete) illustrative robotic arm assembly 700 (which is representative of robotic arm assemblies 628 and 629) holding a surgical instrument 750 (which is representative of tools 638 and 639) for performing a surgical procedure. The surgical instrument 750 is removably held in tool holder 740. The arm assembly 700 is mechanically supported by a base 701, which may be part of a patient-side movable cart or affixed to the operating table or ceiling. It includes links 702 and 703 which are coupled together and to the base 701 through setup joints 704 and 705.

[0275] The setup joints 704 and 705 in this example are passive joints that allow manual positioning of the arm 700 when their brakes are released. For example, setup joint 704 allows link 702 to be manually rotated about axis 706, and setup joint 705 allows link 703 to be manually rotated about axis 707.

[0276] Although only two links and two setup joints are shown in this example, more or less of each may be used as appropriate in this and other robotic arm assemblies described herein. For example, although setup joints 704 and 705 are useful for horizontal positioning of the arm 700, additional setup joints may be included and useful for limited vertical and angular positioning of the arm 700. For major vertical positioning of the arm 700, however, the arm 700 may also be slidably moved along the vertical axis of the base 701 and locked in position.

[0277] The robotic arm assembly 700 also includes three active joints driven by motors. A yaw joint 710 allows arm section 730 to rotate around an axis 761, and a pitch joint 720 allows arm section 730 to rotate about an axis perpendicular to that of axis 761and orthogonal to the plane of the drawing. The arm section 730 is configured so that sections 731 and 732 arealways parallel to each other as the pitch joint 720 is rotated by its motor. As a consequence, the instrument 770 may be controllably moved by driving the yaw and pitch motors so as to pivot about the pivot point 762, which is generally located through manual positioning of the setup joints 704 and 705 so as to be at the point of incision into the patient. In addition, an insertion gear 745 may be coupled to a linear drive mechanism (not shown) to extend or retract the instrument 750 along its axis 763.

[0278] Although each of the yaw, pitch and insertion joints or gears, 710, 720 and 745, is controlled by an individual joint or gear controller, the three controllers are controlled by a common master / slave control system so that the robotic arm assembly 700 (also referred to herein as a “slave manipulator”) may be controlled through user (e.g., surgeon) manipulation of its associated master manipulator.

[0279] In certain embodiments, the robotic surgery system may comprise an input device having a first end and a second end opposite the first end, the first end being movable to provide a desired movement of the surgical instrument, and a secondary control input removably coupled to the second end of the input device such that movement of the control input causes movement of the input device to provide the desired movement of the surgical instrument.

[0280] In embodiments, movement of the secondary control input in a first direction causes movement of the input device in a second direction opposite the first direction. The system may further comprise an endoscope having a distal viewing end facing the first direction. In one such embodiment, the surgical instrument has a distal end facing a second direction, wherein the second direction is between about 90 degrees to about 270 degrees relative to the first direction or substantially 180 degrees relative to the first direction (i.e., the instrument is opposed to, or inverted relative to the endoscope). The secondary control input allows the user to, for example, easily and intuitively operate an instrument that is introduced opposed to the surgical view (i.e., the controls become flipped 180 degrees to control an instrument inverted relative to the endoscope).

[0281] In embodiments, the control input provides a first degree of freedom and the input device provides a second degree of freedom in the opposite direction as the first degree of freedom. In one such embodiment, the system further comprises a monitor coupled to the endoscope for providing an image of an area distal to the endoscope. The first degree of freedom may be a clockwise rotation of the control input, which causes counterclockwise rotation of the input device and clockwise rotation of the surgical instrument relative to theimage provided by the endoscope on the monitor. In another embodiment, the first degree of freedom of the control input may be a longitudinal movement of the control input relative to the user, which causes the surgical instrument to move longitudinally in the same direction relative to the view provided by the endoscope on the monitor.

[0282] In embodiments, the input device comprises a primary user interface on the first end and a shaft on the second end. The secondary control input comprises a shaft having an internal channel with a diameter greater than a diameter of the shaft of the input device. The shaft of the control input is configured to advance over the shaft of the input device to removably coupled the control input to the input device. This allows a user to quickly attach and use the secondary control input to manipulate an instrument that, for example, is opposed to the view of the endoscope.

[0283] In various embodiment, the secondary control unit comprises a handle configured for grasping by the user. In one such embodiment, the handle comprises a substantially cylindrical shape. In another embodiment, the handle comprises a shaft with an end effector. In yet another embodiment, the handle comprises a shaft and first and second arms extending laterally away from the shaft and pivotally coupled to the shaft. By simply feeling the shape of the handle with the user’s hands, the control input focuses the user’s perception of the controls and disambiguates the controls, allowing the user to quickly understand how to manipulate the controls and move the instrument as they expect it to move. This eliminates the confusion of an ambiguous / universal control input. This also eliminates differences between populations of users that prefer “regular” versus “inverted” controls, by making their reference for motion more specific. A more complete description of these elements can be found in commonly assigned co-pending U.S. Provisional Application Serial Nos. 63 / 566,478 and 63 / 566,489, previously incorporated herein by reference.

[0284] In another embodiment, the robotic surgical system may comprise a manipulator assembly having a support structure and one or more manipulators for the surgical instruments coupled to the support structure. Each of the manipulators have a remote center of motion which may be, for example, aligned with the incision point for the instrument being controlled by that manipulator. The system includes a controller configured to generate a central target position over a surgical site and a regulator mechanism for limiting a range of motion of the manipulators relative to the central target position. The system further includes an actuator for unlocking or releasing the central target position to move at least one of the manipulators to alocation outside of its range of motion.

[0285] The system allows surgical teams to establish the central target position in a standard and uniform location for all surgical procedures (i.e., without having to pre- operatively calculate the degrees of freedom required for each manipulator to establish a different central target position for each procedure). In addition, this system allows the central target position to be quickly and easily adjusted before or during the procedure by shifting the working space of the manipulators, which decreases the overall time of the procedure and increases the efficiency of the surgical team, while avoiding potential collisions between the instruments and / or the manipulators. A more complete description of these elements can be found in commonly assigned co-pending U.S. Provisional Application Serial No. 63 / 566,517, previously incorporated herein by reference.

[0286] While several embodiments have been shown in the drawings, it is not intended that the description be limited thereto, as it is intended that the description be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as, exemplifications of presently disclosed embodiments. Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.

[0287] Further, this description's terminology is not intended to limit the devices described herein. The term “force” is to be construed as encompassing both force and torque, unless otherwise indicated herein or clearly contradicted by context. The terms “tools” and “instruments” are used interchangeably herein to refer to the surgical instruments. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The terms “connected” and “coupled” are to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening.

[0288] Spatially relative terms — such as “proximal” and “distal — may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., locations) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, the terms “proximal” and “distal”are relative terms, where the term “distal” refers to the portion of the object furthest from an operator of the instrument and closest to the surgical site, such as the opening of the tool cover or the end effector of the instrument. The term “proximal” indicates the relative proximity to the operator of the surgical instrument and refers to the portion of the object closest to the operator and furthest from the surgical site. In this application, an end effector refers to a tool installed at the distal end of an instrument, including but not limited to forceps or graspers, needle drivers, scalpels, scissors, spatulas, blades, and other tools, which may or may not use energy to cauterize tissue (i.e., a monopolar or bipolar tool).

[0289] Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present description is intended to embrace all such alternatives, modifications and variances. As well, one skilled in the art will appreciate further features and advantages of the present disclosure based on the above-described embodiments. Accordingly, the present description is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

[0290] For example, in a first aspect, a first embodiment is a circular stapling instrument comprising: an elongate shaft; a staple assembly on a distal end portion of the shaft and comprising a distal surface and a plurality of staples; and a tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface of the staple assembly, the tip member being retractable through the staples to a position proximal of the distal surface.

[0291] A second embodiment is the first embodiment, wherein the staple assembly comprises a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the distal surface.

[0292] A third embodiment is any combination of the above embodiments, wherein the tip member is retractable through an internal lumen with the shaft.

[0293] A 4th embodiment is any combination of the above embodiments, wherein the tip member comprises a distal end and a proximal end, wherein the distal end has a smaller diameter than the proximal end.

[0294] A 5th embodiment is any combination of the above embodiments, wherein the tip member tapers from the proximal end to the distal end.

[0295] A 6th embodiment is any combination of the above embodiments, wherein the tip member comprises a substantially cone shape.

[0296] A 7th embodiment is any combination of the above embodiments, wherein the tip member is movable from an expanded position, wherein the proximal end contacts the staple assembly, to a collapsed position, wherein the tip member is movable proximally through the plurality of staples.

[0297] An 8th embodiment is any combination of the above embodiments, wherein the proximal end of the tip member is in contact with the distal surface of the staple assembly in the expanded position.

[0298] A 9th embodiment is any combination of the above embodiments, wherein a portion of the proximal end of the tip member is disposed radially outward from the distal surface of the staple assembly in the expanded position.

[0299] A 10th embodiment is any combination of the above embodiments, wherein the proximal end of the tip member forms a substantially continuous surface with an outer surface of the staple assembly in the expanded position.

[0300] An 11th embodiment is any combination of the above embodiments, further comprising a retraction member coupled to the tip member for proximally retracting the tip member.

[0301] A 12th embodiment is any combination of the above embodiments, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

[0302] A 13th embodiment is any combination of the above embodiments, wherein the tip member comprises an internal surface and a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

[0303] A 14th embodiment is any combination of the above embodiments, wherein the groove is a perforation.

[0304] A 15th embodiment is any combination of the above embodiments, wherein the groove extends along the internal surface of the tip member in a substantially spiral direction.

[0305] A 16th embodiment is any combination of the above embodiments, wherein the tip member comprises a first portion and a second portion, wherein the first portion is detachable from the second portion at the groove.

[0306] A 17th embodiment is any combination of the above embodiments, further comprising an actuator coupled to a proximal end of the retraction member, wherein the actuator is configured to translate the retraction member in a proximal direction.

[0307] An 18th embodiment is any combination of the above embodiments, wherein the actuator is coupled to a motor.

[0308] A 19th embodiment is any combination of the above embodiments, wherein the motor is configured for coupling to a robotic control system.

[0309] A 20th embodiment is any combination of the above embodiments, wherein the tip member comprises a plurality of components removably coupled to each other.

[0310] A 21st embodiment is any combination of the above embodiments, wherein the plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly.

[0311] A 22nd embodiment is any combination of the above embodiments, wherein the components are positioned with the staple assembly in the second position.

[0312] A 23rd embodiment is any combination of the above embodiments, further comprising a biasing member for biasing the components into the first position.

[0313] A 24th embodiment is any combination of the above embodiments, wherein the tip member further comprises an actuator for moving the components between the first and second positions.

[0314] A 25th embodiment is any combination of the above embodiments, wherein the actuator comprises a magnet disposed on, or within, each of the plurality of components.

[0315] A 26th embodiment is any combination of the above embodiments, further comprising an anvil positioned distal to the staple assembly, a cutting element and a driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly

[0316] A 27th embodiment is any combination of the above embodiments, further comprising a first pusher coupled to the staples and a second pusher coupled to the cutting element, wherein the driver comprises a rotatable element coupled to the first and second pushers, wherein rotation of the driver causes longitudinal movement of the first and second pushers.

[0317] A 28th embodiment is any combination of the above embodiments, wherein the first pusher comprises a proximal cam surface and the driver comprises a distal protrusion configured to contact the proximal cam surface, wherein rotation of the driver causes the distal protrusion to move along the proximal cam surface, wherein the first pusher has a longitudinal axis; the proximal cam surface comprises a first portion that extends at a transverse angle to a vertical plane substantially perpendicular to the longitudinal axis such that rotation of the driver and the distal protrusion translates the first pusher in a longitudinal direction, and wherein the proximal cam surface comprises a second portion that is substantially parallel to said vertical plane such that movement of the distal protrusion along the second portion does not translate the first pusher in the longitudinal direction.

[0318] A 29th embodiment is any combination of the above embodiments, wherein the driver advances the staples a first distance and the cutting element a second distance, wherein the second distance is greater than the first distance.

[0319] A 30th embodiment is any combination of the above embodiments, wherein the driver comprises a first set of threads coupled to the first pusher and a second set of threads coupled to the second pusher, wherein the first and second sets of threads are longitudinally spaced from each other to define a gap therebetween.

[0320] A 31 st embodiment is any combination of the above embodiments, wherein the first and second pushers each comprise threads configured to cooperate with the first and second sets of threads of the driver, respectively, to advance the first and second pushers upon rotation of the driver, wherein the first set of threads on the driver disengages from the threads on the first pusher while the second set of threads are still engaged with the threads of the second pusher.

[0321] A 32nd embodiment is any combination of the above embodiments, further comprising an anvil positioned distal to the staple assembly, wherein the anvil comprises a head and a shaft, wherein the head comprises a tissue contacting surface defining staple forming pockets.

[0322] A 33rd embodiment is any combination of the above embodiments, wherein the anvil head comprises first and second components movable relative to each other and configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

[0323] A 34th embodiment is any combination of the above embodiments, wherein the head comprises a plurality of petals each comprising a tissue contacting surface defining staple forming pockets and wherein the petals are configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

[0324] A 35th embodiment is any combination of the above embodiments, wherein the anvil comprises an expandable element coupled to the annular tissue contact surface and configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

[0325] A 36th embodiment is any combination of the above embodiments, further comprising a delivery instrument comprising an elongate shaft with first and second jaws movable between open and closed position and a driver extending through the shaft, the driver including an engagement mechanism for engaging the anvil and moving the anvil between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

[0326] In another aspect, a first embodiment is a retractable tip for use with a circular stapling instrument, the tip comprising: a main body having a substantially circular proximal end and a distal end having a diameter smaller than a diameter of the first end; and an actuator configured to move the main body from an expanded position to a collapsed position, wherein the tip is retractable through at least a portion of the circular stapling instrument in the collapsed position.

[0327] A second embodiment is the first embodiment, wherein the tip member is retractable through a shaft of the stapling instrument in the collapsed position.

[0328] A third embodiment is any combination of the above embodiments, wherein thestapling instrument comprises a staple assembly having a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the staples.

[0329] A 4th embodiment is any combination of the above embodiments, wherein the tip member tapers from the proximal end to the distal end.

[0330] A 5th embodiment is any combination of the above embodiments, wherein the tip member comprises a substantially cone shape.

[0331] A 6th embodiment is any combination of the above embodiments, wherein the proximal end of the tip member is in contact with a distal surface of the staple assembly in the expanded position.

[0332] A 7th embodiment is any combination of the above embodiments, wherein the proximal end of the tip member is disposed radially inward from a distal surface of the staple assembly in the expanded position.

[0333] An 8th embodiment is any combination of the above embodiments, wherein the proximal end of the tip member forms a substantially continuous surface with an outer surface of the staple assembly in the expanded position.

[0334] A 9th embodiment is any combination of the above embodiments, further comprising a retraction member coupled to an internal surface of the tip member for retracting the tip member.

[0335] A 10th embodiment is any combination of the above embodiments, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

[0336] An 11th embodiment is any combination of the above embodiments, wherein the tip member comprises a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

[0337] A 12th embodiment is any combination of the above embodiments, wherein the groove is a perforation.

[0338] A 13th embodiment is any combination of the above embodiments, wherein the groove extends along the internal surface of the tip member in a substantially spiral direction.

[0339] A 14th embodiment is any combination of the above embodiments, wherein the tipmember comprises a first portion and a second portion, wherein the first portion is detachable from the second portion at the groove.

[0340] A 15th embodiment is any combination of the above embodiments, wherein the tip member comprises a plurality of components removably coupled to each other.

[0341] A 16th embodiment is any combination of the above embodiments, wherein the plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly.

[0342] A 17th embodiment is any combination of the above embodiments, wherein the components are positioned with the staple assembly in the second position.

[0343] An 18th embodiment is any combination of the above embodiments, further comprising a biasing member for biasing the components into the first position.

[0344] A 19th embodiment is any combination of the above embodiments, wherein the tip member further comprises an actuator for moving the components between the first and second positions.

[0345] A 20th embodiment is any combination of the above embodiments, wherein the actuator comprises a magnet disposed on, or within, each of the plurality of components.

[0346] In another aspect, a first embodiment is a surgical system comprising: a circular stapler instrument comprising an elongate shaft and a staple assembly with a plurality of staples; a retractable tip configured for positioning distal to the staple assembly; an actuator configured to retract the retractable tip proximally through the staple assembly; and a controller coupled to the actuator for causing the actuator to retract the tip.

[0347] A second embodiment is the first embodiment, further comprising a manipulator arm coupled to the actuator.

[0348] A third embodiment is any combination of the above embodiments, further comprising an input device movable to provide a desired movement of the actuator, wherein the controller is configured to control movement of the retractable tip based on the movement of the input device.

[0349] A 4th embodiment is any combination of the above embodiments, wherein thecircular stapling instrument further comprises an anvil and a driver for advancing the staples towards the anvil, the system further comprising a second controller for actuating the driver.

[0350] A 5th embodiment is any combination of the above embodiments, wherein the staple assembly further comprises a cutting element and wherein the second controller advances the cutting element towards the anvil.

[0351] A 6th embodiment is any combination of the above embodiments, wherein the actuator comprises a retraction member extending through the staple assembly.

[0352] A 7th embodiment is any combination of the above embodiments, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

[0353] An 8th embodiment is any combination of the above embodiments, wherein the tip member comprises an internal surface and a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

[0354] A 9th embodiment is any combination of the above embodiments, wherein the actuator comprises a magnet disposed within the tip member.

[0355] In another aspect, a first embodiment is a circular stapling instrument comprising: an elongate shaft; a staple assembly on a distal end portion of the shaft and comprising a distal surface and a plurality of staples; an anvil positioned distal to the staple assembly; a cutting element; driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly; and an atraumatic tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface of the staple assembly.

[0356] A second embodiment is the first embodiment, wherein the tip member is retractable through the staples to a position proximal of the distal surface.

[0357] A third embodiment is any combination of the above embodiments, wherein the staple assembly comprises a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the distal surface.

[0358] A 4th embodiment is any combination of the above embodiments, wherein the tip member is retractable through an internal lumen with the shaft.

[0359] A 5th embodiment is any combination of the above embodiments, wherein the tipmember comprises a distal end and a proximal end, wherein the distal end has a smaller diameter than the proximal end.

[0360] A 6th embodiment is any combination of the above embodiments, wherein the tip member tapers from the proximal end to the distal end.

[0361] A 7th embodiment is any combination of the above embodiments, wherein the tip member comprises a substantially cone shape.

[0362] An 8th embodiment is any combination of the above embodiments, wherein the tip member is movable from an expanded position, wherein the proximal end contacts the staple assembly, to a collapsed position, wherein the tip member is movable proximally through the plurality of staples.

Claims

1. CLAIMS1. A circular stapling instrument comprising: an elongate shaft; a staple assembly on a distal end portion of the shaft comprising a distal surface and a plurality of staples; and a tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface of the staple assembly, the tip member being retractable through the staples to a position proximal of the distal surface.

2. The circular stapling instrument of claim 1, wherein the staple assembly comprises a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the distal surface.

3. The circular stapling instrument of claim 1, wherein the tip member is retractable through an internal lumen with the shaft.

4. The circular stapling instrument of any one of claims 1 to 3, wherein the tip member comprises a distal end and a proximal end, wherein the distal end has a smaller diameter than the proximal end.

5. The circular stapling instrument of claim 4, wherein the tip member tapers from the proximal end to the distal end.

6. The circular stapling instrument of any one of claims 1 to 5, wherein the tip member comprises a substantially cone shape.

7. The circular stapling instrument of any one of claims 4 to 6, wherein the tip member is movable from an expanded position, wherein the proximal end contacts the staple assembly, to a collapsed position, wherein the tip member is movable proximally through the plurality of staples.

8. The circular stapling instrument of claim 7, wherein the proximal end of the tip member is in contact with the distal surface of the staple assembly in the expanded position.

9. The circular stapling instrument of claim 7, wherein a portion of the proximalend of the tip member is disposed radially outward from the distal surface of the staple assembly in the expanded position.

10. The circular stapling instrument of claim 7, wherein the proximal end of the tip member forms a substantially continuous surface with an outer surface of the staple assembly in the expanded position.

11. The circular stapling instrument of any one of claims 1 to 10, further comprising a retraction member coupled to the tip member for proximally retracting the tip member.

12. The circular stapling instrument of claim 11, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

13. The circular stapling instrument of any one of claims 11 and 12, wherein the tip member comprises an internal surface and a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

14. The circular stapling instrument of claim 13, wherein the groove is a perforation.

15. The circular stapling instrument of any one of claims 13 and 14, wherein the groove extends along the internal surface of the tip member in a substantially spiral direction.

16. The circular stapling instrument of any one of claims 13 to 15, wherein the tip member comprises a first portion and a second portion, wherein the first portion is detachable from the second portion at the groove.

17. The circular stapling instrument of any one of claims 12 to 16, further comprising an actuator coupled to a proximal end of the retraction member, wherein the actuator is configured to translate the retraction member in a proximal direction.

18. The circular stapling instrument of claim 17, wherein the actuator is coupled to a motor.

19. The circular stapling instrument of claim 18, wherein the motor is configuredfor coupling to a robotic control system.

20. The circular stapling instrument of any one of claims 1 to 19, wherein the tip member comprises a plurality of components removably coupled to each other.

21. The circular stapling instrument of claim 20, wherein the plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly.

22. The circular stapling instrument of claim 21, wherein the components are positioned with the staple assembly in the second position.

23. The circular stapling instrument of claim 21, further comprising a biasing member for biasing the components into the first position.

24. The circular stapling instrument of claim 20, wherein the tip member further comprises an actuator for moving the components between the first and second positions.

25. The circular stapling instrument of claim 24, wherein the actuator comprises a magnet disposed on, or within, each of the plurality of components.

26. The circular stapling instrument of any one of claims 1 to 25, further comprising an anvil positioned distal to the staple assembly, a cutting element and a driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly27. The circular stapling instrument of claim 26, further comprising a first pusher coupled to the staples and a second pusher coupled to the cutting element, wherein the driver comprises a rotatable element coupled to the first and second pushers, wherein rotation of the driver causes longitudinal movement of the first and second pushers.

28. The circular stapling instrument of claim 27, wherein: the first pusher comprises a proximal cam surface and the driver comprises a distal protrusion configured to contact the proximal cam surface, wherein rotation of the driver causes the distal protrusion to move along the proximal cam surface, wherein the firstpusher has a longitudinal axis; the proximal cam surface comprises a first portion that extends at a transverse angle to a vertical plane substantially perpendicular to the longitudinal axis such that rotation of the driver and the distal protrusion translates the first pusher in a longitudinal direction, and wherein the proximal cam surface comprises a second portion that is substantially parallel to said vertical plane such that movement of the distal protrusion along the second portion does not translate the first pusher in the longitudinal direction.

29. The circular stapling instrument of claim 27, wherein the driver advances the staples a first distance and the cutting element a second distance, wherein the second distance is greater than the first distance.

30. The circular stapling instrument of claim 29, wherein the driver comprises a first set of threads coupled to the first pusher and a second set of threads coupled to the second pusher, wherein the first and second sets of threads are longitudinally spaced from each other to define a gap therebetween.

31. The circular stapling instrument of claim 30, wherein the first and second pushers each comprise threads configured to cooperate with the first and second sets of threads of the driver, respectively, to advance the first and second pushers upon rotation of the driver, wherein the first set of threads on the driver disengages from the threads on the first pusher while the second set of threads are still engaged with the threads of the second pusher.

32. The circular stapling instrument of any one of claims 1 to 31, further comprising an anvil positioned distal to the staple assembly, wherein the anvil comprises a head and a shaft, wherein the head comprises a tissue contacting surface defining staple forming pockets.

33. The circular stapling instrument of claim 32, wherein the anvil head comprises first and second components movable relative to each other and configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

34. The circular stapling instrument of claim 33, wherein the head comprises a plurality of petals each comprising a tissue contacting surface defining staple forming pockets and wherein the petals are configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

35. The circular stapling instrument of claim 33, wherein the anvil comprises an expandable element coupled to the annular tissue contact surface and configured for deploying between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

36. The circular stapling instrument of any of claims 26 to 35, further comprising a delivery instrument comprising an elongate shaft with first and second jaws movable between open and closed position and a driver extending through the shaft, the driver including an engagement mechanism for engaging the anvil and moving the anvil between a collapsed configuration with a first lateral dimension and an expanded configuration with a second lateral dimension, wherein the first lateral dimension is smaller than the second lateral dimension.

37. A retractable tip for use with a circular stapling instrument, the tip comprising: a main body having a substantially circular proximal end and a distal end having a diameter smaller than a diameter of the first end; and an actuator configured to move the main body from an expanded position to a collapsed position, wherein the tip is retractable through at least a portion of the circular stapling instrument in the collapsed position.

38. The retractable tip of claim 37, wherein the tip member is retractable through a shaft of the stapling instrument in the collapsed position.

39. The retractable tip of claim 37, wherein the stapling instrument comprises a staple assembly having a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the staples.

40. The retractable tip of any one of claims 37 to 39, wherein the tip member tapers from the proximal end to the distal end.

41. The retractable tip of any one of claims 37 to 40, wherein the tip member comprises a substantially cone shape.

42. The retractable tip of any one of claims 37 to 41, wherein the proximal end of the tip member is in contact with a distal surface of the staple assembly in the expanded position.

43. The retractable tip of any one of claims 37 to 42, wherein the proximal end of the tip member is disposed radially inward from a distal surface of the staple assembly in the expanded position.

44. The retractable tip of any one of claims 37 to 43, wherein the proximal end of the tip member forms a substantially continuous surface with an outer surface of the staple assembly in the expanded position.

45. The retractable tip of any one of claims 37 to 44, further comprising a retraction member coupled to an internal surface of the tip member for retracting the tip member.

46. The retractable tip of claim 45, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

47. The retractable tip of claim 45, wherein the tip member comprises a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

48. The retractable tip of claim 47, wherein the groove is a perforation.

49. The retractable tip of any one of claims 47 and 48, wherein the groove extends along the internal surface of the tip member in a substantially spiral direction.

50. The retractable tip of any one of claims 47 to 49, wherein the tip member comprises a first portion and a second portion, wherein the first portion is detachable fromthe second portion at the groove.

51. The retractable tip of any one of claims 37 to 50, wherein the tip member comprises a plurality of components removably coupled to each other.

52. The retractable tip of claim 51, wherein the plurality of components are movable between a first position, wherein the components are in contact with each other and positioned distal of the distal surface of the staple assembly, and a second position, wherein the components are spaced from each other and positioned proximal to the distal surface of the staple assembly.

53. The retractable tip of claim 52, wherein the components are positioned with the staple assembly in the second position.

54. The retractable tip of claim 53, further comprising a biasing member for biasing the components into the first position.

55. The retractable tip of claim 54, wherein the tip member further comprises an actuator for moving the components between the first and second positions.

56. The retractable tip of claim 55, wherein the actuator comprises a magnet disposed on, or within, each of the plurality of components.

57. A surgical system comprising: a circular stapler instrument comprising an elongate shaft and a staple assembly with a plurality of staples; a retractable tip configured for positioning distal to the staple assembly; an actuator configured to retract the retractable tip proximally through the staple assembly; and a controller coupled to the actuator for causing the actuator to retract the tip.

58. The surgical system of claim 57, further comprising a manipulator arm coupled to the actuator.

59. The surgical system of claim 58, further comprising an input device movable to provide a desired movement of the actuator, wherein the controller is configured to control movement of the retractable tip based on the movement of the input device.

60. The surgical system of any one of claims 57 to 59, wherein the circular stapling instrument further comprises an anvil and a driver for advancing the staples towards the anvil, the system further comprising a second controller for actuating the driver.

61. The surgical system of claim 60, wherein the staple assembly further comprises a cutting element and wherein the second controller advances the cutting element towards the anvil.

62. The surgical system of any one of claims 57 to 61, wherein the actuator comprises a retraction member extending through the staple assembly.

63. The surgical system of claim 62, wherein the retraction member comprises an elongate flexible member extending through the staple assembly.

64. The circular stapling instrument of claim 63, wherein the tip member comprises an internal surface and a groove extending along the internal surface and the elongate flexible member has a proximal end coupled to the groove.

65. The surgical system of any one of claims 57 to 64, wherein the actuator comprises a magnet disposed within the tip member.

66. A circular stapling instrument comprising: an elongate shaft; a staple assembly on a distal end portion of the shaft and comprising a distal surface and a plurality of staples; an anvil positioned distal to the staple assembly; a cutting element; driver configured to sequentially advance the staples and the cutting element such that the staples contact the anvil before the cutting element is advanced distal of the staple assembly; andan atraumatic tip member removably coupled to the staple assembly adjacent to, or in contact with, the distal surface of the staple assembly.

67. The circular stapling instrument of claim 66, wherein the tip member is retractable through the staples to a position proximal of the distal surface.

68. The circular stapling instrument of claim 67, wherein the staple assembly comprises a central opening within the plurality of staples, wherein the tip member is retractable into the central opening to a position proximal of the distal surface.

69. The circular stapling instrument of claim 67, wherein the tip member is retractable through an internal lumen with the shaft.

70. The circular stapling instrument of any one of claims 66 to 69, wherein the tip member comprises a distal end and a proximal end, wherein the distal end has a smaller diameter than the proximal end.

71. The circular stapling instrument of claim 70, wherein the tip member tapers from the proximal end to the distal end.

72. The circular stapling instrument of any one of claims 66 to 72, wherein the tip member comprises a substantially cone shape.

73. The circular stapling instrument of any one of claims 70 to 72, wherein the tip member is movable from an expanded position, wherein the proximal end contacts the staple assembly, to a collapsed position, wherein the tip member is movable proximally through the plurality of staples.

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