Cutting ring assembly with rigid cutting member

Abstract

The present disclosure relates to a cut ring assembly including a backup member, an intermediate member and a cutting ring body. The intermediate member is formed of a thin, rigid material that is sandwiched between the backup member and the cutting ring body. The thin, rigid material is formed of a material having a hardness less than the hardness of the backup member and greater than the hardness of the cutting ring body. The present disclosure also relates to an anvil assembly including such a cut ring assembly.

Description

BACKGROUND

1. Technical Field

The present disclosure relates to a cutting ring assembly for use with a surgical stapling device. More specifically, the present disclosure relates to a cutting ring assembly for use with a circular stapling device having a thin, rigid cutting member.

2. Background of Related Art

Surgical stapling devices having an end effector configured to clamp and suture tissue are well known in the medical arts. Typically, these devices include a first jaw that supports an anvil assembly and a second jaw that supports a cartridge assembly which houses a plurality of staples. The first and second jaws are movable in relation to each other between spaced and approximated positions to clamp tissue between the jaws prior to firing the staples into the tissue. The first and second jaws may also support two part fasteners or first and second compression members that interact to suture tissue.

Circular stapling devices are used to perform end-to-end anastomosis procedures within a patient. During an end-to-end anastomosis procedure, an end of a first vessel portion is joined to an end of a second vessel portion. It is not uncommon in such procedures for the ends of the vessel portions to be joined to include staple lines that seal the end of each of the vessel portions.

Typically, circular stapling devices include an annular knife which translates through the anvil and cartridge assemblies to core tissue within the first and second vessel portions to provide an unobstructed passage within the joined vessel portions. It is common for the anvil assembly to include a backup member, e.g., a cutting washer, positioned to engage the annular knife to allow the knife to more easily cut through tissue. However, even with the inclusion of a backup member, the annular knife of conventional circular stapling devices may have difficulty cutting through staples or sutures positioned in tissue between the annular knife and the cutting washer.

A need exists in the medical arts for an improved backup member for use with a circular stapling device that allows for effective coring of tissue and sutures positioned in tissue.

SUMMARY

One aspect of the present disclosure is directed to an anvil assembly including an anvil center rod, an anvil head supporting an anvil plate having a plurality of staple deforming pockets, and a cut ring assembly supported within the anvil head adjacent the anvil plate. The cut ring assembly includes a backup member, an intermediate member and a cutting ring body. The intermediate member is formed of a thin, rigid material and is sandwiched between the backup member and the cutting ring body. The thin, rigid material is formed of a material having a hardness less than the hardness of the backup member and greater than the hardness of the cutting ring body.

In embodiments, the intermediate member has a thickness of between 0.005 inch and 0.020 inch. In certain embodiments, the intermediate member has a thickness of 0.010 inch.

In some embodiments, the intermediate member is secured to the backup member with an adhesive and the cutting ring body is secured to the intermediate member with an adhesive.

In some embodiments, the cutting ring body is molded onto the backup member and the intermediate member.

In certain embodiments, the backup member is formed from a metal, the cutting ring body is formed of a plastomer and the intermediate member is formed of a rigid plastic material. The backup member can be formed from stainless steel and the intermediate member can be formed from a polymer such as a polyester, e.g., polyethylene terephthalate (PET or PETG).

In embodiments, the anvil head defines an anvil post and each of the backup member, the cutting ring body, and the intermediate member defines a central opening. The cutting ring assembly is slidable about the post of the anvil head.

In embodiments, the backup member defines a platform which is received within the openings of the cutting ring body and the intermediate member.

In some embodiments, the backup member forms an inner surface of the anvil head.

In another aspect of the disclosure a cut ring assembly includes a backup member, an intermediate member and a cutting ring body. The intermediate member is sandwiched between the backup member and the cutting ring body and is formed of a thin, rigid material having a hardness less than the hardness of the backup member and greater than the hardness of the cutting ring body.

In embodiments, the intermediate member has a thickness of between 0.005 inch and 0.020 inch. In certain embodiments, the intermediate member has a thickness of 0.010 inch.

In some embodiments, the intermediate member is secured to the backup member with an adhesive and the cutting ring body is secured to the intermediate member with an adhesive.

In certain, embodiments, the cutting ring body is molded onto the backup member and the intermediate member.

In some embodiments, the backup member is formed from a metal, the cutting ring body is formed of a plastomer and the intermediate member is formed of a rigid plastic material.

In embodiments, the backup member is formed from stainless steel and the intermediate member is formed from a polymer such as a polyester, e.g., polyethylene terephthalate (PET or PETG).

In embodiments, the backup member defines a platform which is received within the openings of the cutting ring body and the intermediate member.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed cutting ring assembly are described herein with reference to the drawings, wherein:

FIG. 1 is a side perspective view of a surgical stapling device including an end effector in an unapproximated position;

FIG. 2 is an enlarged view of the indicated area of detail shown in FIG. 1;

FIG. 3 is a side cross-sectional view through the end effector of a conventional surgical stapler;

FIG. 4 is a side perspective view of one embodiment of the presently disclosed cutting ring assembly;

FIG. 5 is a side perspective view of the cutting ring assembly shown in FIG. 4 with parts separated;

FIG. 6 is a cross-sectional view taken along section lines 6-6 of FIG. 4;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG. 6;

FIG. 8 is a side perspective view of another embodiment of the presently disclosed cutting ring assembly;

FIG. 9 is a side perspective view of the cutting ring assembly shown in FIG. 8 with parts separated; and

FIG. 10 is a cross-sectional view of the cutting ring assembly taken along section line 10-10 of FIG. 8.

DETAILED DESCRIPTION OF EMBODIMENTS

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. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

As used herein, the term distal refers to that portion of the device which is farthest from the clinician, while the term proximal refers to that portion of the instrument which is closest to the clinician. In addition, as used herein, the term clinician refers to medical staff including doctors, nurses and support personnel.

The present disclosure is directed to a cutting ring assembly, described in detail below, which includes a thin, rigid member positioned between a hard back up member and a softer cutting member. The thin rigid member provides a shearing surface that facilitates cutting through hard staples which may be positioned in tissue being sutured. The thin rigid member also allows a knife blade which may be deformed as the knife blade engages a hard staple to pass cleanly through the staple. Additional advantages of the presently disclosed cutting ring assembly are described below.

FIGS. 1 and 2 illustrate a surgical stapling device 10 including a handle assembly 12, an elongated body portion 14 which is supported by and extends distally from the handle assembly 12, and an end effector 16 supported on a distal end of the elongated body portion 14. Although the handle assembly 12 is illustrated as including an electro-mechanical hand piece, it is envisioned that the presently disclosed cutting ring assembly discussed in further detail below is suitable for use with stapling devices having manually actuated handpieces such as disclosed in U.S. Pat. No. 7,303,106 (“the '106 patent”) which is incorporated herein by reference in its entirety. The end effector 16 includes an anvil assembly 18 and a shell or cartridge assembly 20.

FIG. 3 illustrates a conventional anvil assembly 18 that includes, inter alia, an anvil center rod 22, a pivotal anvil head 24 supported on the anvil center rod 22 about a pivot member 26, and a cutting ring assembly 28 that is slidable about a post 30 of the anvil head 24. The cutting ring assembly 28 is axially aligned with and positioned to engage an annular knife 32 of the cartridge assembly 20. U.S. Pat. No. 7,494,038 (“the '038 patent”) discloses an anvil assembly similar to that shown in FIG. 3 and is incorporated herein by reference in its entirety.

As best shown in FIG. 3, the cutting ring assembly 28 of the anvil assembly 18 includes a backup plate 40 and a cutting ring body 42 that is positioned on the backup plate 40. The backup plate 40 is formed from a hard material such as a metal, e.g., sintered stainless steel, and the cutting ring body 42 is formed of a softer material such as polyethylene or a plastomer, e.g., metallocene.

FIGS. 4 and 5 illustrate one embodiment of the presently disclosed cutting ring assembly shown generally as 100. The cutting ring assembly 100 is suitable for use in the anvil head 24. Thus, the components of the anvil head 24, excluding the cutting ring assembly 100, will be described with reference to FIG. 3. Cutting ring assembly 100 includes a backup member 120, a cutting ring body 122 and an intermediate member 124. The backup member 120 includes a substantially centrally located opening 134 which is dimensioned to be positioned about the post 30 (FIG. 3) of the anvil head 24 within an inner annular recess 50 of the anvil head 24. The inner annular recess 50 of the anvil head 24 is located between the post 30 and an outer annular recess 52 which receives an anvil plate 51 having a plurality of staple forming depressions 51a.

Backup member 120 includes a raised center platform 120a. The cutting ring body 122 defines an opening 122a that has an inner configuration substantially the same as the platform 120a such that the cutting ring body 122 is received about the platform 120a. A pair of diametrically opposed fingers 123 extend inwardly from the platform 120a and function to prevent the anvil head 24 (FIG. 1) from tilting prior to firing of the stapling device 10 such as taught in '038 patent which is incorporated herein by reference as discussed above.

The intermediate member 124 also defines an opening 124a that is configured to receive the post 30 of the anvil head 24. The intermediate member 124 is sandwiched between the backup member 120 and the cutting ring body 122. The backup member 120, cutting ring body 122 and the intermediate member 124 can be fixedly secured together using adhesives. Alternately, the cutting ring body 122 can be molded about the backup member 120 and the intermediate member 120 after the intermediate member 124 is assembled onto the backup member 120.

In embodiments, the backup member 120 includes a plurality of radially extending tabs 136 that extend outwardly from the raised platform 120a and the cutting ring body 122 includes a series of tabs 138 and recesses 140 defined along an inner periphery of the cutting ring body 122 about the opening 122a. The tabs 136 are received within the recesses 140 and the tabs 138 engage an outer periphery of the raised platform 120a to properly position the cutting ring body 122 about the raised platform 120a. Similarly, the intermediate member 124 includes a series of inwardly extending tabs 142 formed about the opening 124a which engage the outer periphery of the raised platform 120a to properly position the intermediate member 124 about the raised platform 120a.

As shown in FIG. 5, the backup member 120 also defines openings 144 and the intermediate member 124 defines scallops 146. When the cutting ring assembly 100 is assembled, the openings 144 in the backup member 120, the scallops 146 in the intermediate member 124 and the recesses 140 in the cutting ring body 122 communicate with each other to allow fluid to pass through the cutting ring assembly 100.

In embodiments, the cutting ring assembly 100 is configured to be slidable about the post 30 of the anvil head 24. In such embodiments, the backup member 120 can include a pair of inwardly extending fingers 145 which are configured to engage a surface of the anvil center rod 22 (FIG. 3) to prevent the anvil head 24 from tilting in relation to the anvil center rod 22. This tilting operation is described in detail in the '038 patent which has been incorporated by reference into this application as discussed above. As such, no further discussion of the operation of the tilting anvil head 24 is included in this application.

The outer surface of the cutting ring body 122 may include a series of outwardly extending projections 123 which are positioned to be received within recesses or an annular recess (not shown) within the anvil head 24 to secure the cutting ring body 122 within the anvil head 124. Alternately, other fastening techniques can be used to secure the cutting ring body 122 within the anvil head 24.

As discussed above with regard to the cutting ring assembly 28, the backup member 120 of the cutting ring assembly 100 is formed of a hard material such as a metal, e.g., sintered stainless steel, and the cutting ring body 122 is formed of a softer material, e.g., a plastomer or polyethylene. The intermediate member 124 is formed of a material that is harder than the cutting ring body 122 but softer than the backup member 120. In one embodiment, the intermediate member 124 is formed of a thin, rigid plastic material. For example, the intermediate member can be formed of a polymer, such as a polyester, e.g., a polyethylene terephthalate (PET or PETG). In embodiments, the intermediate member 124 is sandwiched between the backup member 120 and the cutting ring body 122 and has a thickness of from about 0.005 of an inch to about 0.020 of an inch. In other embodiments, the cutting ring body 122 has a thickness of about 0.010 of an inch.

Although the cutting ring assembly 100 is disclosed as being slidably positioned about the post 30 of the anvil head 24, it envisioned that the cutting ring assembly 100 can be securely fastened within the anvil head 24 and that the backup member 120 can be defined by or form an inner surface of the anvil head 24. More specifically, the backup member 120 can be integrally formed with the inner surface of the anvil head 24 (FIG. 3). In such an embodiment, the intermediate member 124 is secured directly to the inner surface of the anvil head 24 and the cutting ring body 122 is secured to an upper surface of the intermediate member 124.

Referring to FIGS. 6 and 7, when the stapling device 10 (FIG. 1) is actuated to advance the annular knife 32 towards the cutting ring assembly 100, the annular knife 32 travels through the softer material of the cutting ring body 122, into the harder surface of the intermediate member 124, and into the harder surface of the backup member 120. As discussed above, the backup member 120 may be movably supported about the post 30 of the anvil head 24 or define a inner wall of the anvil head 24.

The provision of an intermediate member 124 as described above between the backup member 120 and the cutting ring body 122 provides a number of advantages over conventional cutting ring assemblies in addition to those discussed above. For example, the thin, hard surface of the intermediate member 124 provides a shearing surface for cutting through harder staples that may get embedded in the softer cutting ring body. The use of a thin, hard surface may also reduce the cutting forces required to cut tissue as compared to cutting tissue against a metal surface. The provision of a thin, rigid material also enables the use of less expensive metal materials which have rough surface finishes to form the backup member (or inner surface of the anvil head) against which the annular knife bottoms out and the flatness tolerance of the metal surface below the cutting ring body to be less tight since the thickness of the thin, rigid material will compensate for the imperfections in the metal surface.

FIGS. 8-10 illustrate an alternate embodiment of the presently disclosed cutting ring assembly shown generally as 200. Cutting ring assembly 200 is substantially similar to cutting ring assembly 100 and includes a backup member 220, a cutting ring body 222 and an intermediate member 224. The backup member 220 is identical to the backup member 120 and will not be discussed in further detail herein. The cutting ring member 222 is similar to cutting ring member 122 except that the opening 222a is circular and does not include the series of tabs 138 and recesses 140 that are provided along the inner periphery of the cutting ring body 122 of cutting ring assembly 100. Similarly, the intermediate member 224 is similar to the intermediate member 124 except that the inner periphery of the intermediate member 224 is circular and does not include the tabs 142 and scallops 146 of the intermediate member 124. The cutting ring assembly 200 functions in a substantially similar manner to the cutting ring assembly 100 and will not be described in further detail herein.

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. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

Claims

1. An anvil assembly comprising: an anvil center rod;an anvil head supporting an anvil plate having a plurality of staple deforming pockets; anda cut ring assembly supported within the anvil head adjacent the anvil plate, the cut ring assembly including a backup member, an intermediate member and a cutting ring body, the backup member formed of a single integral material, wherein the intermediate member is formed of a thin, rigid material and is sandwiched directly between the backup member and the cutting ring body, wherein the intermediate member is in direct contact with the backup member and the cutting ring body, the thin, rigid material being formed of a material having a hardness less than the hardness of the backup member and greater than the hardness of the cutting ring body.

2. The anvil assembly according to claim 1, wherein the intermediate member has a thickness of between 0.005 of an inch and 0.020 of an inch.

3. The anvil assembly according to claim 1, wherein the intermediate member has a thickness of 0.010 of an inch.

4. The anvil assembly according to claim 1, wherein the intermediate member is secured to the backup member with an adhesive.

5. The anvil assembly according to claim 4, wherein the cutting ring body is secured to the intermediate member with an adhesive.

6. The anvil assembly according to claim 1, wherein the cutting ring body is molded onto the backup member and the intermediate member.

7. The anvil assembly according to claim 1, wherein the backup member is formed from a metal, the cutting ring body is formed of a plastomer and the intermediate member is formed of a rigid plastic material.

8. The anvil assembly according to claim 7, wherein the backup member is formed from stainless steel and the intermediate member is formed from a polymer.

9. The anvil assembly according to claim 1, wherein the anvil head defines an anvil post and each of the backup member, the cutting ring body, and the intermediate member defines a central opening, the cutting ring assembly being slidably positioned about the post of the anvil head.

10. The anvil assembly according to claim 9, wherein the backup member defines platform which is received within the openings of the cutting ring body and the intermediate member.

11. The anvil assembly according to claim 1, wherein the backup member forms an inner surface of the anvil head.

12. A cut ring assembly comprising: a backup member, an intermediate member and a cutting ring body, the intermediate member being sandwiched directly between the backup member and the cutting ring body and being formed of a thin, rigid material having a hardness less than the hardness of the backup member and greater than the hardness of the cutting ring body, the backup member formed of a single integral material.

13. The anvil assembly according to claim 12, wherein the intermediate member has a thickness of between 0.005 inch and 0.020 inch.

14. The anvil assembly according to claim 13, wherein the intermediate member has a thickness of 0.010 inch.

15. The anvil assembly according to claim 12, wherein the intermediate member is secured to the backup member with an adhesive.

16. The anvil assembly according to claim 12, wherein the cutting ring body is secured to the intermediate member with an adhesive.

17. The anvil assembly according to claim 12, wherein the cutting ring body is molded onto the backup member and the intermediate member.

18. The anvil assembly according to claim 12, wherein the backup member is formed from a metal, the cutting ring body is formed of a plastomer and the intermediate member is formed of a rigid plastic material.

19. The anvil assembly according to claim 18, wherein the backup member is formed from stainless steel and the intermediate member is formed from a polymer.

20. The anvil assembly according to claim 12, wherein the backup member defines platform which is received within the openings of the cutting ring body and the intermediate member.