Method of stapling tissues with a staple assembly

[0001] This application is a National Stage Application of PCT/US2008/062635 filed May 5, 2008 under 35 USC §371(a), which claims priority of U.S. Provisional Application Ser. No. 60/928,244 filed on May 7, 2007, the entire contents of which are incorporated herein by reference.

[0002] Technical Field

[0003] The present disclosure relates to a variable size, uniform compression staple assembly and an associated anvil for use with a surgical stapling device. More particularly, the present disclosure relates to a two part, variable size, and uniform compression staple assembly for use with various thickness of tissue and an associated anvil for forming the staple assembly about the tissue.

[0004] Background of Related Art

[0005] Surgical stapling instruments or surgical staplers are used in many surgical operations to secure or join two or more tissue sections together. Some known surgical staplers are preloaded with a pre-chosen specific size staple for use in the surgical operations. However, the chosen staple is only capable of effectively sealing together a limited range of thicknesses of tissues. If the tissues are too thick for the chosen staple, the surgical stapler may not fully crimp the staple about the tissue resulting in the tissues pulling apart. Conversely, if the tissues are too thin for the chosen staple, the crimped or formed staple may not have enough compression to fully seal the tissues together resulting in leakage between the tissues. In other situations where the tissues are too thin for the chosen staple, the staple may be over crimped causing tissue penetrating tips of the staple to recurve back upon itself resulting in unnecessary puncturing of the tissues and again the possibility of leakage between the tissues.

[0006] Some surgical staplers are capable of accepting replaceable staple containing cartridges. Various ranges of different size staples may be provided by these cartridges for selection by a surgeon depending on the anticipated tissue thickness to be encountered. However, during a surgical operation, the surgical stapler needs to be removed from the operative site in order to replace one size staple cartridge with another when encountering differing thicknesses of tissues other than those anticipated.

[0007] Thus, it is desirable to provide a single size staple assembly capable of effectively stapling and sealing various thicknesses of tissue together. It is further desirable to provide an anvil for use with a surgical stapler and capable of securing components of a single size staple assembly together about tissue.

[0008] There is provided a staple assembly for use with various thicknesses of tissues. The staple assembly includes a staple having a backspan and a pair of legs extending from the backspan. Each of the legs terminates in a tissue penetrating tip. The staple assembly further includes a staple block for receipt of the tissue penetrating tips such that the tissue penetrating tips lodge in the staple block upon being formed in a surgical stapler.

[0009] In one use of the disclosed staple assembly, the staple block receives the tissue penetrating tips along a common axis. In an alternative use of the staple assembly the staple block receives the tissue penetrating tips along parallel axes.

[0010] The staple and staple block of the staple assembly cooperate such that the tissue penetrating tips lodge into the staple block to a first depth upon passage through a first tissue having a first thickness. When formed about a second tissue having a second tissue thickness, the tissue penetrating tips lodge into the staple block to a second depth different from the first depth. The depth of penetration of the tissue penetrating tips into the staple block is inversely proportional to the tissue thickness encountered.

[0011] In one embodiment, the staple block is formed of a composite material. In alternative embodiments, the staple block is formed from materials such as, a plastic material, a polymeric material, an absorbable material, etc.

[0012] There is also provided an anvil for use with the disclosed two part staple assembly. The anvil includes an anvil plate having a first staple clinching pocket, a second staple clinching pocket spaced apart from the first staple clinching pocket and a recess for receipt of a component of a two part staple assembly. The recess is defined between the first and second staple clinching pockets.

[0013] In one embodiment, the recess is rectangular for receipt of a staple block of the staple assembly.

[0014] In one embodiment, the first staple clinching pocket lies along a first axis and the second staple clinching pocket lies along a second axis, wherein the second axis is parallel to the first axis. In another embodiment, the first and second axes lie along a common axis.

[0015] There is further provided a method of stapling tissues of differing thicknesses with a uniform size staple assembly. The method includes providing a surgical stapler having a staple head containing a staple and an anvil, the staple head and anvil being relatively movable. The anvil releasably contains a staple block. A tissue having a first thickness is captured between the staple head and the anvil. The staple is passed through the tissue such that tips of the staple lodge into the staple block to a depth inversely proportional to the first thickness of the tissue.

[0016] In one embodiment of the disclosed method, the tips of the staple pass into the staple block along parallel axes. In another embodiment of the disclosed method, the tips of the staple pass into the staple block along a common axis.

[0030] Embodiments of the presently disclosed variable size, uniform compression staple assembly and associated anvil will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term “proximal” refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term “distal” refers to that part or component further away from the user.

[0031] Referring initially to FIG. 1, there is disclosed an anvil 10 for use with a surgical stapler 12. Surgical stapler 12 is of a type typically used for open surgery procedures and includes a pistol grip handle 14 having an elongate member 16 extending distally from handle 14. Elongate member 16 terminates in a generally U-shaped anvil support 18. Anvil 10 is mounted on anvil support 18. Surgical stapler 12 also includes a staple containing head or staple head 20 which contains a plurality of uniform size staples as described in more detail hereinbelow. Staple head may be removable and replaceable. An adjustment knob 22 is provided on handle 14 and operates to move staple head 20 relative to anvil 10 in known manner in order to capture the tissue to be stapled therebetween. A trigger 24 is provided to actuate stapler 12 and eject a staple out of staple head 20, through tissue and into anvil 10.

[0032] Referring now to FIG. 2, anvil 10 includes an anvil plate 28 which is mounted to anvil support 18. Anvil plate 28 defines a plurality of staple forming pockets 30 which cooperate with staple head 20 to form, and support part of, a staple assembly. Anvil plate includes an alignment pin 32 and an alignment recess 34 which cooperate with a corresponding recess and pin on staple head 20 to ensure staples contained within staple head 20 are in proper alignment with staple forming pockets 30 during stapling of tissue.

[0033] With reference to FIG. 3, staple forming pocket 30 generally includes a first staple clinching depression or pocket 36 and a second staple clinching pocket 38 spaced apart from first staple clinching pocket 36. Pockets 36 and 38 are provided to receive tips of a staple and direct them toward a staple block 40 positioned in a narrowed central area 42 of staple forming pocket 30. A center point 44 of first staple clinching pocket 36 lies along an axis X-X while a center point 46 of second staple clinching pocket 38 lies along an axis Y-Y. In one embodiment, axis X-X is parallel to axis Y-Y. In an alternative embodiment, axis X-X is a common axis with axis Y-Y. The orientation of axis X-X relative to axis Y-Y determines how tips of a staple received within staple pockets 36 and 38, respectively, are guided into staple block 40 in a manner described in more detail hereinbelow.

[0034] As shown in FIG. 4, staple forming pocket 30 is provided with a rectangular recess 48 defined in narrowed central area 42. Recess 48 is provided to releasably retain staple block 40 within staple forming pocket 30. Staple block 40 may be retained in friction fit fashion or otherwise relasably held within recess 48 in staple forming pocket 30.

[0035] Referring now to FIG. 5, there is disclosed a novel, two part staple assembly 50 including staple block 40 and a staple 52 for use in stapling various thicknesses of tissue. By providing staple assembly with staple block 40, a single size staple 52 can be used to staple and effectively seal various thicknesses of tissues without having to change staple sizes as discussed herein. U-shaped staple 52 generally includes a backspan 54 and a pair of legs 56 and 58 extending from backspan 54. Legs 56 and 58 terminate in tissue penetrating tip sections 60 and 62, respectively.

[0036] As best shown in FIG. 6, when assembled, tip sections 60, 62 penetrate, and are lodged in, staple block 40. Staple block 40 may be formed from a variety of materials including composite, plastic or polymeric materials, absorbable materials, etc, or any other material capable of being penetrated by staple 52. Tip sections 60, 62 penetrate staple block 40 to a depth d1 which may vary depending on the thickness of tissue being stapled. Thus, staple block 40 is available to “take up” any excess length in legs 56 and 58 and allow a uniform or single size staple 52 to be used with various thicknesses of tissue. It should be noted that, while tip sections 60 and 62 are illustrated as entering staple block 40 substantially straight and parallel to the surfaces of rectangular staple block 40, in some instances tip sections 60 and 62 may be deformed or curved back toward backspan 54 slightly due to engagement with first and second staple clinching pockets 36 and 38, respectively.

[0037] As noted above, first and second clinching pockets 36 and 38, respectively, of staple forming pocket 30 are provided to direct tip sections 60, 62 into staple block 40. When axis X-X of first staple clinching pocket 36 lies along a common axis with axis Y-Y of second staple clinching pocket 38, tip sections 60,62 enter staple block 40 along a common axis.

[0038] Referring for the moment to FIG. 7, when staple forming pocket 30 is configured such that axis X-X of first staple clinching pocket 36 lies along a parallel but not common axis with axis Y-Y of second staple clinching pocket 38, tip sections 60, 62 enter staple block 40 on parallel but uncommon axes. In this embodiment of staple forming pocket 30, staple block 40 is capable of “taking up” an even greater amount of excess length in legs 56 and 58. Configuring staple forming pocket 30 in this manner is useful when a large range of tissue thicknesses are anticipated to be encountered during surgery.

[0039] It is also contemplated that the staple legs can enter the staple block on different non-parallel axes, with the anvil pockets formed to direct the legs in such manner.

[0040] Referring now to FIGS. 8-12, and initially with regard to FIG. 8, the use of staple assembly 50 and anvil 10, incorporated into surgical stapler 12 by way of example, to staple a tubular tissue T having a given thickness will now be described. It should be noted that, while the following discussion of the use of staple assembly 50 and anvil 10 is given in connection with one type of open surgery style surgical stapler 12, staple assembly 50 and anvil 10 find equal application when used in other types of open or minimally invasive surgical staplers, such as, for example, endoscopic or laparoscopic staplers, circular or anastomotic staplers, etc. Further, staple assembly 50 and anvil 10 are equally suited for use in stapling tissues other than tubular tissue sections.

[0041] Surgical stapler 12 is provided with a plurality of staples 52 loaded in staple head 20 in a manner discussed in more detail hereinbelow. Surgical stapler 12 is initially placed such that tissue section T is positioned between anvil 10 and staple head 20. Thereafter, adjustment knob 22 is manipulated to move staple head 20 toward anvil 10 and capture tissue T therebetween.

[0042] As shown in FIG. 9, captured tissue T has a thickness d2. Upon movement of staple head 20 toward anvil 10, alignment pin 32 on anvil plate 28 enters a recess 64 in staple head 20 and a staple head pin 66 on staple head 20 enters alignment recess 34 in anvil plate 28 to ensure proper alignment of staple legs 56 and 58 with staple clinching pockets 36 and 38, respectively. As noted above, staple head 20 is provided with a plurality of staples 52. Specifically, staples 52 are contained within staple pockets, such as staple pocket 68, formed in staple head 20. A pusher 70 is positioned within staple pocket 68 and is movable within staple pocket 68 in response to actuation of trigger 24 of surgical stapler 12. Movement of pusher 70 within staple pocket 68 causes pusher 70 to engage backspan 54 of staple 52 and drive staple 52 out of staple head 20 toward anvil 10.

[0043] Referring now to FIGS. 8 and 10, once surgical stapler 12 has been positioned about tissue T, lock lever 26 is disengaged from trigger 24 and trigger 24 is actuated (FIG. 8) to cause driver 70 to move distally within staple pocket 68 (FIG. 10). With continued reference to FIG. 10, pusher 70 drives staple 52 distally within staple pocket 68 such that tissue penetrating tip sections 60, 62 pass through tissue T. Upon engagement of tip sections 60, 62 with first and second staple clinching pockets 36 and 38, respectively, tip sections 60, 62 are clinched or deflected toward staple block 40 and penetrate tissue block 40 to depth d1. Tissue T is thus stapled between backspan 54 of staple 52 and staple block 40 and tip sections 60, 62. It should be noted that the depth d1 of penetration of tip sections 60, 62 into staple block 40 is inversely proportional to the thickness d2 of tissue T captured between anvil 10 and staple head 20 of surgical stapler 12. That is to say that the greater the thickness d2 of tissue t the less the depth d1 of penetration of tip sections 60, 62 into staple block 40. Tissue T is effectively sealed and stapled with staple assembly 50 without over or under penetration of staple 52.

[0044] Referring now to FIG. 11, staple assembly 50 is illustrated stapling an alternative tissue section T2 having a captured thickness d3 different from tissue thickness d2 described hereinabove. As shown, tip sections 60, 62 penetrate staple block 40 to a depth d4, which is inversely proportional to thickness d3, to effectively seal and staple tissue section T2 with staple assembly 50.

[0045] Referring further to FIG. 12, staple assembly 50 is illustrated stapling a further tissue section T3 having a captured tissue thickness d5 different from thickness d2 and d3 of tissue sections T and T2 described hereinabove (d5>d3>d2). Tip sections 60, 62 penetrate staple block 40 to a depth d6 which is inversely proportional to tissue thickness d5. Thus, it can be seen that staple assembly 50 in conjunction with anvil 10 is capable of stapling tissues of differing thickness utilizing only a single size staple 52 without over or under penetration of the subject tissue and attendant undesirable consequences.

[0046] It will be understood that various modifications may be made to the embodiments disclosed herein. For example, as noted above, the disclosed staple assembly and anvil configuration may find uses in other surgical stapling apparatuses than that shown. Also, although the stapling head is shown movable toward the anvil, the anvil could be movable instead, or both the anvil and staple head could be movable, to obtain the relative movement for approximation of the stapling head and anvil. Further, while the disclosed staple block and anvil pocket recess are shown as being rectangular, other shapes, such as round oval, triangular, etc. are contemplated herein to take up excess length of staple legs and provide a secure sealing and stapling of tissue. The staple block can be made up of a material which is loaded with or coated with a drug to aid in the healing of the tissue. Additionally, when used with a surgical stapling instrument capable of orienting the anvil at an angle relative to the staple head, the tips of the staple legs of specific staples within the staple head may enter their associated staple blocks to differing depths. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.