Two piece anvil for surgical stapler

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 60/981,129, filed Oct. 19, 2007, the entire disclosure of which is incorporated by reference herein.

[0002] 1. Technical Field

[0003] The present disclosure relates to surgical stapling apparatus, and more particularly, relates to a surgical stapler having a two piece anvil for deforming a staple.

[0004] 2. Background of Related Art

[0005] Surgical staplers and other such devices for applying a staple to tissue are known in the art. Conventional stapling devices may be configured for use externally, i.e. wound closure, for use in open procedures, or for use in closed procedures, i.e. endoscopic or laparoscopic. When a surgical stapler is being used to join tissue, whether it be for wound closure or in an anastomotic procedure, the two portions of tissue must be approximated towards one another prior to stapling to ensure that each portion of tissue is pierced by at least one leg of the staple. Approximating the tissue portions towards one another requires manipulation of the tissue prior to stapling. Manipulating the tissue prior to stapling requires some degree of traction on the tissue and may require a free hand or additional instruments to accomplish. This problem is magnified during endoscopic and laparoscopic procedures where space is limited and access is minimal.

[0006] A surgical stapling assembly for applying staples is disclosed. The stapling assembly includes a staple cartridge for retaining and selectively releasing a plurality of staples, a forming member engageable by a staple during formation thereof, and first and second anvil sections for forming the staples, wherein the first and second anvil sections are configured for independent actuation.

[0007] In a preferred embodiment, the forming member comprises a forming bar mounted to a distal portion of the staple cartridge, and the anvil sections from the staples around the forming bar. In a preferred embodiment, the anvil sections are operably mounted on the staple cartridge between the forming bar and the staple cartridge and actuation of the first anvil section deforms a first leg of a staple and actuation of the second anvil section deforms a second leg of a staple.

[0008] In a preferred embodiment, each of the staples in the staple cartridge has a backspan and first and second legs extending from the backspan, and the deforming leg of the first anvil section initially deforms the first leg of the staple and the deforming leg of the second anvil section subsequently deforms the second leg of the staple.

[0009] Further disclosed is a method of stapling tissue. The method of stapling includes the steps of providing a surgical stapler including a staple assembly having first and second anvil sections, positioning the surgical stapler near a first flap of tissue to be stapled, actuating the staple assembly such that first anvil section deforms a first leg of a staple, approximating the first tissue flap towards a second tissue flap, and further actuating the staple assembly, thereby causing the second anvil section to deform a second leg of the staple. The method may further include the step of releasing the actuation member, thereby disengaging first and second anvil section from about the staple.

[0010] A method of stapling first and second sections of tissue is also disclosed wherein the method comprises the steps of:

[0011] providing a surgical stapler including at least one staple having first and second legs and first and second anvil sections;

[0012] positioning the surgical stapler near the first portion of tissue to be stapled;

[0013] advancing the first anvil section to deform the first leg of a staple;

[0014] approximating the first tissue section towards the second tissue section; and

[0015] subsequently advancing the second anvil section to deform the second leg of the staple.

[0016] Preferably, advancing the first anvil section deforms the first staple leg to extend inwardly toward the second staple leg and advancing the second anvil section deforms the second staple leg to extend inwardly toward the first staple leg to form a substantially box-shaped staple.

[0017] In one embodiment, the step of subsequently advancing the second anvil section comprises the step of fully actuating an actuator after partial actuation to advance the first anvil section. In another embodiment, the step of subsequently advancing the second anvil section comprises the step of actuating a second actuator after actuation of a first actuator to advance the first anvil section.

[0033] Reference will now be made to the drawings wherein like reference numerals illustrate similar components throughout the several views. As shown in the drawings and as described throughout the following description, as is traditional when referring to relative positioning of an object, the term “proximal” refers to the end of the apparatus which is closer to the user and the term “distal” refers to the end of the apparatus which is further from the user.

[0034] Referring initially to FIGS. 1-4, a prior art staple assembly is shown generally as staple assembly 10. Briefly, staple assembly 10 includes a staple cartridge 12 including a mounting assembly 13 on a distal end 12b thereof, a forming bar 14 mounted on a tab 13a formed on mounting assembly 13, and a one piece anvil 20 slidably mounted on tab 13a of mounting assembly 13 between forming bar 14 and distal end 12b of cartridge 12. Cartridge 12 is configured to retain a plurality of staples (not shown). Staple assembly 10 is further configured to deform and release a staple 50 (FIG. 3) upon actuation thereof. For purposes of the following disclosure, prior to deformation (FIG. 3), staple 50 is a generally U-shaped member having a backspan 52 and parallel first and second legs 52a, 52b extending therefrom. Once deformed, staple 50 defines a substantial box shape (FIG. 4) wherein first and second legs 52a, 52b are moved towards one another. The actuation of stapling assembly 10 is described in commonly assigned U.S. Pat. Nos. 5,289,963 and 5,560,532, the entire contents of each are hereby incorporated by reference, and will not be discussed in further detail herein.

[0035] With particular reference to FIGS. 2 and 3, prior art one piece anvil 20 includes a base 22, a pair of forming legs 24, 26 for deforming staple 50 and a corresponding pair of prongs 25, 27 for engaging an actuation member. Turning now to FIGS. 3 and 4, forming bar 14 includes a forming member 14a. Forming member 14a is substantially parallel to the staple backspan 52 and is configured to retain staple 50 as forming legs 24, 26 of anvil 20 deform staple 50 thereabout.

[0036] Staple assembly 10 operates to deform staple 50 so as to pinch or retain a first and second flap of tissue T₁, T₂ (FIG. 14) between first and second legs 52a, 52b of staple 50. Operation of staple assembly 10 requires that the first and second flaps of tissue be approximated towards one another prior to stapling. As discussed above, manipulation of either or both flaps of tissue requires some degree of traction on the tissue. This additional manipulation of the tissue to approximate the flaps sufficiently so that they may be stapled together using a device having a one piece anvil may not be possible, depending on the location of the target site and the condition of the surrounding tissue. This is especially true for endoscopic or laparoscopic procedures where space is limited and access is minimal.

[0037] Referring now to FIGS. 5-14, a staple assembly 110 of the present disclosure including a two piece anvil 120 is shown. Staple assembly 110 is substantially similar to staple assembly 10 in some respect and will only be described in relation to the differences therebetween.

[0038] Referring initially to FIG. 5, two piece anvil 120 includes first and second anvil sections 122a, 122b slidable relative to each other. First and second anvil sections 122a, 122b are substantial mirror images of one another. Each of first and second anvil sections 122a, 122b includes a forming leg 124, 126 and an engagement prong 125, 127, respectively. Distal end 124a, 126a of forming legs 124, 126, respectively, may define a lip or groove for more securely engaging base 52 of staple 50 (FIG. 6) during actuation of staple assembly 110. As will be discussed in greater detail below, first and second anvil sections 122a, 122b are configured to be actuated independently of one another.

[0039] Turning briefly to FIG. 6, staple assembly 110 includes a mounting assembly 113 on a distal end 112b of cartridge assembly 112. Mounting assembly 113 includes a tab 113a. Two piece anvil 120 is slidably mounted on a tab 113a between forming member (bar) 114 and distal end 112a of cartridge assembly 112, with the tab 113a extending through the opening in the forming bar 114. A staple pusher 115 biases staples 50 towards forming surface 114a of forming bar 114.

[0040] The operation of staple assembly 110 will now be described with reference to FIGS. 7-14. Initially, staple 50 is positioned between forming member 114a of forming bar 114 and distal ends 124a, 126a of forming legs 124, 126 of two piece anvil 120 (FIG. 7). The distal end 60 of a surgical stapling device (not shown) is approximated near a first flap of tissue T₁ to be stapled. Partial actuation of an actuation mechanism (not shown) causes first anvil section 122a of two piece anvil 120 to advance towards forming member 114a, thereby deforming first leg 52a of staple 50 about forming bar 114 and piercing first flap of tissue T₁ (FIG. 10). The piercing of first flap of tissue T₁ with first leg 52a of staple 50 permits a surgeon to approximate first flap of tissue T₁ towards second flap of tissue T₂.

[0041] Once first and second flaps of tissue T₁, T₂ are sufficiently approximated towards one another (FIG. 11) the stapling thereof may be completed. Further actuation of actuation mechanism (not shown) causes second anvil section 126 of two piece anvil 120 to advance towards forming bar 114, thereby deforming second leg 52b of staple 50 about forming bar 114(FIG. 12). In this manner, second leg 52b of staple 50 pierces second tissue flap T₂, thereby retaining first and second tissue flaps T₁, T₂ in an approximated relationship with one another (FIG. 13). Release of the actuation mechanism (not shown) causes the retraction of two piece anvil 120, thereby releasing deformed staple 50 from stapling assembly 110 (FIG. 14).

[0042] Unlike with prior art staplers, during wound closure procedures using a surgical stapler incorporating a two piece anvil 120, first and second flaps of tissue T₁, T₂ do not need to be manipulated prior to stapling. Thus, traction on either the first and/or second flap of tissue T₁, T₂ prior to stapling is unnecessary to effect proper closure. In this manner, a surgeon need not need touch tissue T prior to stapling, nor does the surgeon need a free hand or second device to approximate the first and second flaps of tissue T₁, T₂ towards one another. It is envisioned that the aspects of the present disclosure may be adapted for staples having any number of sizes and configurations.

[0043] As described above, independent actuation of the anvil sections occurs as the actuator upon partial advancement advances the first anvil section and upon further advancement (e.g. full actuation) advances the second anvil section. However, alternatively, a separate actuator could be utilized to advance each of the anvil sections which can occur in sequential steps, e.g. the second actuator can be actuated after full or partial actuation of the first actuator.

[0044] Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.