Devices and methods for shortening rectal stumps during low anterior resection procedures - Patents.com

Abstract

A loading unit for a circular stapling device includes a shell member, a staple pusher assembly operably disposed within the shell member, a knife pusher assembly operably disposed within the shell member, a trocar assembly operably disposed within the shell member, and a tissue retracting assembly disposed within the shell member between the knife pusher assembly and the trocar assembly. The shell member includes an elongated tubular portion. The trocar assembly includes a trocar member movable from an advanced position and a retracted position. The tissue retracting assembly includes a tissue retracting device.

Description

[Technical field]

[0001] The present disclosure relates generally to devices and methods for forming an anastomosis after removing a portion of diseased tissue from a tubular organ, and more specifically to devices and methods for shortening a rectal stump prior to forming an anastomosis during a low anterior resection procedure. [Background technology]

[0002] Devices are known for performing a low anterior resection (LAR) procedure to treat rectal cancer. During a LAR procedure, a diseased portion of the rectum is removed and a healthy portion of the rectum is reconnected to the colon. Circular stapling devices are known for forming an end-to-end anastomosis. Typically, a portion of the colon is secured to an anvil assembly of the circular stapling device and a portion of the rectal stump is secured around a loading unit of the circular stapling device. The rectal stump is usually shortened as much as possible. To shorten the rectal stump to a desired length using conventional methods requires additional devices that may be bulky or difficult to manipulate.

[0003] Therefore, it would be beneficial to have a circular stapling device configured to shorten the rectal stump prior to creating the anastomosis. Summary of the Invention [Means for solving the problem]

[0004] A loading unit for a circular stapling device includes a shell member, a staple pusher assembly operably disposed within the shell member, a knife pusher assembly operably disposed within the shell member, a trocar assembly operably disposed within the shell member, and a tissue retracting assembly disposed within the shell member between the knife pusher assembly and the trocar assembly. The shell member includes an elongated tubular portion. The trocar assembly includes a trocar member movable from an advanced position and a retracted position. The tissue retracting assembly includes a tissue retracting device.

[0005] In certain aspects of the present disclosure, the elongated tubular portion of the shell member is between 6 and 12 inches long. The elongated tubular portion may include inner and outer portions and define a cavity between the inner and outer portions. The staple pusher assembly and the knife pusher assembly may be operably received within the cavity and may be movable between advanced and retracted positions.

[0006] In another aspect of the present disclosure, a tissue retraction assembly includes a holder. The holder may define a longitudinal opening and may be selectively movable along the inner portion of the shell member. The tissue retraction device may extend through the longitudinal opening of the holder. The tissue retraction device may be longitudinally fixed relative to the holder.

[0007] The circular stapler includes an adapter assembly configured for operative connection to an actuation assembly and a loading unit. It includes a shell member, a staple pusher assembly operatively disposed within the shell member, a knife pusher assembly operatively disposed within the shell member, a trocar assembly operatively disposed within the shell member, and a tissue retracting assembly disposed within the shell member between the knife pusher assembly and the trocar assembly. The shell member includes an elongated tubular portion. The trocar assembly includes a trocar member movable from an advanced position and a retracted position. The tissue retracting assembly includes a tissue retracting device.

[0008] In certain aspects of the present disclosure, the elongated tubular portion of the shell member is between 6 and 12 inches in length. The elongated tubular portion may include inner and outer portions and define a cavity between the inner and outer portions. The staple pusher assembly and the knife pusher assembly may be operably received within the cavity and may be movable between advanced and retracted positions.

[0009] In another aspect of the present disclosure, a tissue retraction assembly includes a holder. The holder may define a longitudinal opening and may be selectively movable along the inner portion of the shell member. The tissue retraction device may extend through the longitudinal opening of the holder. The tissue retraction device may be longitudinally fixed relative to the holder.

[0010] A method of forming an anastomosis includes receiving a loading unit into a patient's rectal stump, advancing a tissue retraction device from the loading unit, securing the tissue retraction device to the rectal stump, retracting the tissue retraction device into the loading unit such that the rectal stump is retracted into the loading unit to shorten the rectum and stump, and clamping, stapling and severing the rectal stump.

[0011] In certain aspects of the present disclosure, securing the tissue retraction device to the rectal stump includes suturing the rectal stump to the tissue retraction device. Advancing the tissue retraction device from the loading unit may also include advancing a holder. Retracting the tissue retraction device includes retracting the holder. The method may further include positioning a staple cartridge of the loading unit adjacent the patient's anus as the rectal stump is retracted into the loading unit. The method may also include securing the colon to an anvil assembly and securing the anvil assembly relative to the loading unit.

[0012] Aspects of the disclosed devices and methods for shortening a rectal stump during a low anterior resection procedure are described herein with reference to the drawings. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective side view of a circular stapling instrument according to an aspect of the present disclosure; [Diagram 2] FIG. 2 is a perspective end view of the circular stapling instrument shown in FIG. 1; [Diagram 3]FIG. 3 is a perspective side view, with parts separated, of a loading unit of the circular stapling instrument shown in FIGS. 1 and 2; [Figure 4] FIG. 3 is an enlarged view of the indicated area of ​​detail shown in FIG. 2. [Diagram 5] FIG. 4 is a cross-sectional side view of the loading unit shown in FIG. 3 received within the rectal stump of a patient. [Figure 6] FIG. 6 is an enlarged view of the indicated area of ​​detail shown in FIG. 5. [Figure 7] FIG. 6 is an enlarged view of the indicated area of ​​detail shown in FIG. 5. [Figure 8] FIG. 8 is a cross-sectional end view taken along line 8-8 shown in FIG. 6. [Figure 9] 4 is a perspective end view of a shell member of the loading unit shown in FIG. 3. [Figure 10] FIG. 4 is a cross-sectional side view of the distal portion of the loading unit shown in FIG. 3, with the tissue retraction device of the loading unit in an advanced position and secured to the rectal stump. [Figure 11] FIG. 11 is a cross-sectional side view of the loading unit shown in FIG. 10 with the tissue retraction device in a retracted position. [Figure 12] FIG. 12 is a cross-sectional side view of the loading unit shown in FIG. 11 , the anvil assembly being secured to the trocar assembly of the loading unit; [Figure 13] FIG. 13 is a cross-sectional side view of the loading unit shown in FIG. 12 with the anvil assembly in the clamping position and each of the staple pusher assembly and the knife pusher assembly in the advanced position; [Figure 14] FIG. 14 is a cross-sectional side view of the loading unit shown in FIG. 13 after forming the anastomosis and after removal from the anus. [Figure 15] 1 is a flow chart of a method for creating an anastomosis during a low anterior resection procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The disclosed device and method will now be described in detail with reference to the drawings, in which like reference numerals indicate the same or corresponding elements in each of the several views. However, it should be understood that the aspects of the disclosure provided herein are merely exemplary of the disclosure, which may be embodied in various forms. Well-known functions or structures are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be construed as limiting, but merely as a representative basis for teaching those skilled in the art to employ the present disclosure in various ways in substantially any appropriately detailed structure.

[0015] In this description, the term "proximal" is generally used to refer to the portion of the device closer to the clinician, while the term "distal" is generally used to refer to the portion of the device further from the clinician. Additionally, the term "endoscopic" is generally used to refer to endoscopes, laparoscopes, arthroscopes, and / or any other procedure performed through a small diameter incision or cannula. Additionally, the term "clinician" is generally used to refer to medical personnel, including doctors, nurses, and support personnel. As used herein, the term "about" means that the numerical value is an approximate value, and small variations do not significantly affect the practice of the disclosed embodiments. When a numerical limitation is used, unless otherwise indicated by the context, "about" means that the numerical value can vary by ±10% and remain within the scope of the disclosed embodiments.

[0016] 1 and 2 show a circular stapling device, generally indicated as circular stapler 10, including a circular loading unit, generally indicated as loading unit 100. Circular stapler 10 includes a handle assembly 12, an adapter assembly or elongated body 14, a loading unit 100, and an anvil assembly 18 movably supported relative to loading unit 100 between a spaced ( FIG. 12 ) position and an approximated ( FIG. 13 ) or clamped position, as known in the art. A proximal portion 14a of adapter assembly 14 is releasably coupled to handle assembly 12, and loading unit 100 is releasably coupled to a distal portion 14b of adapter assembly 14. Handle assembly 12 includes a stationary grip 20 that supports actuation buttons 22 for controlling actuation of various functions of circular stapler 10, including approximation of loading unit 100 and anvil assembly 18, firing staples from circular stapler 100, and cutting or coring tissue (not shown) clamped between loading unit 100 and anvil assembly 18. Although handle assembly 12, adapter assembly 14, and loading unit 100 are shown as separate components releasably coupled to one another, it is envisioned that any one or all of the components may be integrally formed.

[0017] The circular stapler 10 is shown as a powered stapling device including a powered handle assembly 12 that may support one or more batteries (not shown). The elongated body 14 is in the form of an adapter assembly that transfers power from the handle assembly 12 to the loading unit 100 and the anvil assembly 18. Examples of powered stapling devices can be found in U.S. Pat. Nos. 9,055,943, 9,023,014, and U.S. Patent Application Publication Nos. 2018 / 0125495 ("'495 Publication") and 2017 / 0340351, the entire contents of which are incorporated herein by reference in their entireties. Although shown and disclosed as relating to a powered handle assembly, it is envisioned that aspects of the present disclosure may be incorporated into manually operated stapling devices. See U.S. Pat. Nos. 7,364,760 and 7,303,106 for exemplary manually operated stapling devices. It is also envisioned that aspects of the present disclosure may be incorporated into a robotically controlled stapling device.

[0018] 3 illustrates a loading unit 100 of circular stapler 10 including a shell member or housing 110, a staple cartridge 120 for supporting a plurality of staples "S", a staple pusher assembly 130, a knife pusher assembly 140 positionable radially inward of staple pusher assembly 130, a trocar assembly 150 positionable radially inward of knife pusher assembly 140, and a tissue retracting assembly 160 positionable between trocar assembly 150 and knife pusher assembly 140. As will become apparent from the following disclosure, loading unit 100 is structurally and functionally similar to known loading units and therefore only the differences therebetween will be described in detail. For a detailed description of an exemplary loading unit, see the '495 publication.

[0019] Shell member 110 of loading unit 100 includes a connector portion 112 on proximal portion 110a for operatively connecting to adapter assembly 14 and a tubular portion 114 extending from connector portion 112. Connector portion 112 supports a locking sleeve 116 and a locking ring 118. Although shown including a locking sleeve 116 and a locking ring 118, it is envisioned that loading unit 100 may be releasably secured to adapter assembly 14 in any suitable manner. Tubular portion 114 of shell member 110 includes an outer housing portion 114a and an inner housing portion 114b spaced apart from outer housing portion 112 to define an annular cavity 113 ( FIG. 9 ). Annular cavity 113 is configured to operatively receive staple pusher assembly 130, knife pusher assembly 140 and tissue retraction assembly 160. The inner housing portion 114b is configured to operably receive the trocar assembly 140 and includes a tapered distal end 114c. The shell member 110 of the loading unit 100 is disposed between the connector portion 112 and the tubular portion 114 and defines an opening 115 (FIG. 4) in fluid communication with the annular cavity 113. The distal portion 110b of the shell member 110 is configured to support a staple cartridge 120. The shell member 110 includes a length sufficient to accommodate shortening of the rectal stump, as described below. The shell member 110 may be about two to about six times longer than the shell members of conventional circular staple loading units. It is envisioned that the length of the shell member 110 may be anywhere from three inches (3'') to ten inches (10'').

[0020] Staple cartridge 120 of loading unit 100 is supportable in distal portion 110b of shell member 110 and defines an annular row of staple pockets 121. Each of staple pockets 121 supports one of a plurality of staples "S." Although shown including three rows of staple pockets 121, it is envisioned that staple cartridge 120 may support any number of rings of staples "S" in any suitable configuration.

[0021] The staple pusher assembly 130 of the loading unit 100 includes a staple pusher base 132, a staple pusher extension 134, and a staple pusher member 136. The staple pusher assembly 130 is movable within the annular cavity 113 (FIG. 4) of the shell member 110 between a retracted position (FIG. 5) and an advanced position (FIG. 13) to eject staples "S" from the staple cartridge 120. The staple pusher member 136 of the staple pusher assembly 130 includes a plurality of fingers 138 that correspond to the staple pockets 121 of the staple cartridge 120. The plurality of fingers 138 are movable through respective staple pockets 121 to eject staples "S" from the staple pockets 121 when the staple pusher assembly 130 is moved from the retracted position (FIG. 5) to the advanced position (FIG. 13) within the shell member 110. Staple pusher extension 134 includes a length configured to accommodate the increased length of shell member 110. A detailed description of the structure and function of an exemplary staple pusher assembly is provided in the '495 publication, the contents of which were previously incorporated by reference in their entirety.

[0022] Knife pusher assembly 140 of loading unit 100 includes a knife pusher base 142, a knife pusher extension 144, and an annular knife 146. Knife assembly 140 is movable within annular cavity 113 (FIG. 4) of shell member 110 between a retracted position (FIG. 5) and an advanced position (FIG. 13) to sever tissue. Knife pusher assembly 140 is advanceable independently of advancement of staple pusher assembly 130, although simultaneous advancement is contemplated. Knife pusher extension 144 includes a length configured to accommodate the increased length of shell member 110. A detailed description of the structure and function of an exemplary knife pusher assembly is provided in the '495 publication.

[0023] The trocar assembly 150 of the loading unit 100 includes a trocar housing 152, a trocar member 154 extending from the trocar housing 152, and a drive member 156 rotatably supported within the trocar housing 152. A sleeve 158 is receivable around the trocar member 154 and configured to reduce friction between the trocar member 154 and the inner wall 114b of the shell member 110. The trocar housing 152 of the trocar assembly 150 is configured to be releasably secured within the distal portion 14b of the adapter assembly 14 (FIG. 1) of the annular stapler 10, allowing for sterilization and reuse of the trocar assembly 150. Alternatively, the trocar assembly 150 is integrally formed with the adapter assembly 14.

[0024] Trocar member 154 of trocar assembly 150 includes an internally threaded proximal portion 154a (FIG. 5), an elongated central portion 154b, and a sharpened distal portion 154c. Proximal, central, and distal portions 154a, 154b, 154c may be integrally formed and / or may be formed as separate components secured together in any suitable manner. Drive member 156 of trocar assembly 150 includes a proximal portion 156a configured to engage a rotational drive member (not shown) extending through adapter assembly 14, and a threaded distal portion 156b for engaging with internally threaded proximal portion 154a of trocar member 154. Rotation of drive member 156 in a first direction causes advancement of trocar member 154 relative to trocar housing 154, and rotation of drive member 156 in a second direction causes retraction of trocar member 154 relative to trocar housing 152. Elongated central portion 154b of trocar member 154 includes a length configured to accommodate the increased length of shell member 110. A detailed description of the structure and function of an exemplary trocar assembly is provided in the '495 publication.

[0025] The tissue retraction assembly 160 of the loading unit 100 includes a holder or guide 162 and a tissue retraction device 164 extending through the holder 162. The holder 162 is configured to be received about the inner housing portion 114b of the tubular portion 114 of the shell member 110. As described in further detail below, the holder 162 of the tissue retraction assembly 160 is configured to slide along the inner housing portion 114a of the shell assembly 110 during tissue retraction. The holder 162 defines a longitudinal opening 163 for receiving a distal portion of the tissue retraction device 164. The tissue retraction device 164 includes a piercing distal tip 164b and defines an eye 165 along a distal portion thereof.

[0026] The loading unit 100 includes a bushing 170 positionable within the connector portion 112 of the shell member 110 to secure the connection between the staple pusher base 132 of the staple pusher assembly 130 and a staple driver (not shown) and between the knife pusher base 142 of the knife pusher assembly 140 and a knife drive (not shown).

[0027] A method of performing an anastomosis procedure including shortening of the rectal stump during a low anterior resection (LAR) procedure utilizing the loading unit 100 will now be described in detail with reference to Figures 5-15. First, using conventional means, the clinician removes the diseased portion of the tubular organ leaving a rectal stump "St" (Figure 5). The rectal stump "St" can have any length "L" and does not need to be shortened prior to using the circular stapler 10 (Figure 1).

[0028] 5-8 show the loading unit 100 of the circular stapler 10 received through a patient's anus "A" and into the rectal stump "St" during a LAR procedure. The loading unit 100 is configured such that a proximal portion of the shell member 110 remains outside of the anus "A" while the cartridge assembly 120 at a distal portion of the shell member 110 is positioned adjacent to a distal portion of the rectal stump "St". In this manner, the tissue retraction device 164 of the tissue retraction assembly 160 remains accessible to the clinician.

[0029] Prior to introduction of loading unit 100 through the anus "A" into the patient's rectal stump "St," each of stapler pusher assembly 130, knife pusher assembly 140, trocar member 154 of trocar assembly 150, and tissue retracting assembly 160 of loading unit 100 are in their retracted positions. More specifically, staple pusher assembly 130 and knife pusher assembly 140 are in their proximal-most positions within shell member 110, and trocar member 154 is fully retained in inner housing portion 114b of shell member 110. Tissue retracting assembly 160 is positioned within cavity 113 between knife pusher assembly 130 and inner housing portion 114b. The holder 162 of the tissue retracting assembly 160 is in its distal-most position about the inner housing portion 114 b of the shell member 110 and a piercing distal tip 164 b of the tissue retracting device 164 of the tissue retracting assembly 160 is spaced from the staple cartridge 120 .

[0030] FIG. 10 illustrates securing the rectal stump "St" to the tissue retraction device 164 of the tissue retraction assembly 160. More specifically, the tissue retraction device 164 is moved, e.g., advanced, distally as indicated by arrow "a" such that the piercing distal tip 164b of the tissue retraction device 164 pierces the rectal stump "St". The tissue retraction device 164 is advanced until the eye 165 of the tissue retraction device 164 is positioned adjacent a distal portion of the rectal stump "St". The rectal stump "St" is then secured to the tissue retraction device 164 in any suitable manner. As illustrated, the rectal stump "St" is secured to the tissue retraction device 164 using sutures "s". It is also envisioned that the tissue retraction device may include a hook or other gripping mechanism for securing the rectal stump "St" to the tissue retraction device 164. As shown, tissue retraction device 164 of tissue retraction assembly 160 is longitudinally fixed relative to holder 162. In this manner, advancement of tissue retraction device 164 causes advancement of holder 162, and retraction of tissue retraction device 164 causes retraction of holder 162. It is also envisioned that tissue retraction device 164 may move independently of holder 162.

[0031] 11 illustrates the patient's rectal stump "St" being retracted, more specifically, invaginated, into the loading unit 100. More specifically, proximal movement, e.g., retraction as indicated by arrow "b," of the tissue retraction device 164 retracts the rectal stump "St" into the cavity 113 of the shell member 110 between the knife pusher extension 144 and the annular knife 146 of the knife pusher assembly 140 and the inner housing portion 114b of the shell member 110. As described above, the tissue retraction device 164 is longitudinally fixed relative to the holder 162, so that retraction of the tissue retraction device 164 causes a simultaneous retraction of the holder 162. The tissue retraction device 164 retracts relative to the shell member 110 unit, and the rectal stump "St" includes a length "l." The length "l" may include any length that the clinician determines is most suitable for the anastomosis procedure. The length of the shell member 110 can be increased to accommodate any length of rectal stump "St."

[0032] As the rectal stump "St" is drawn into the shell member 110 of the loading unit 100, the loading unit 100 is gradually drawn through the anus "A" until the staple cartridge 120 at the distal end of the loading unit 100 is positioned adjacent the anus "A".

[0033] 12 illustrates anvil assembly 18 being secured to trocar member 154 of trocar assembly 150 of loading unit 100. Prior to securing anvil assembly 18 to trocar member 154, a portion of intestine "I" is secured around head assembly 18a of anvil assembly 18. Conventionally, tissue is secured to head assembly 18a of anvil assembly 18 using a purse string suture (not shown). Trocar member 154 is moved to a distal position to facilitate attachment of anvil assembly 18 to trocar member 154.

[0034] 13 illustrates the loading unit 100 during stapling and severing the rectal stump "St" and the portion of intestine "I" to form the anastomosis "α". More specifically, the staple pusher assembly 130 and the knife pusher assembly 140 are shown in their advanced positions. As previously discussed, the staple pusher assembly 130 and the knife pusher assembly 140 may advance independently or simultaneously. Prior to advancement of the staple pusher assembly 130, retraction of the trocar member 154 of the trocar assembly 150 approximates the anvil assembly 18 relative to the staple cartridge 120 for clamping tissue of the rectal stump "St" and the portion of intestine "I" between the head assembly 18a of the anvil assembly 18 and the staple cartridge 120 of the loading unit 100.

[0035] FIG. 14 illustrates the loading unit 100 after formation of anastomosis "α" and removal of the loading unit 100 from the patient's anus "A". To allow tilting of the head assembly 18a of the anvil assembly 18, the anvil assembly 18 is first advanced relative to the loading unit 100 by advancing the trocar member 154 of the trocar assembly 100. As the head assembly 18a of the anvil assembly 18 clears the staple cartridge 120 of the loading unit 100, the head assembly 18a pivots to a tilted position to allow removal of the anvil assembly 18 and the loading unit 100 from the anus "A". The discard portion "StW" of the rectal stump is removed with the loading unit 100 and discarded in a conventional manner. The remaining portion "StR" of the rectal stump is secured to the intestinal portion "I" at the anastomosis "α".

[0036] It is envisioned that the loading unit may be configured for single use, e.g., disposable, or may be configured for sterilization and reuse. The loading unit 100 is available in a variety of lengths and diameters, as well as a variety of staple configurations.

[0037] FIG. 15 is a flow chart of a method 500 of forming an anastomosis including shortening of a rectal stump. In review, initially, the method includes identifying diseased tissue and separating the diseased tissue from surrounding healthy tissue (510). Next, the method includes introducing a loading unit of a circular stapler through the patient's anus into the rectal stump (520). Next, the method includes advancing a tissue retracting device of the loading unit distally to penetrate the rectal stump (530) and secure the rectal stump to the tissue retracting device (540). Next, the method includes retracting the tissue retracting device to retract the rectal stump into the loading unit, thereby shortening the rectal stump (550). At any point after forming the first and second portions of the tubular tissue, the method includes securing the first portion of tissue to the anvil assembly (560). The method then includes completing the anastomosis procedure (570) with securing the anvil assembly to the loading unit, clamping the tissue to be stapled, stapling the clamped tissue, and cutting the clamped tissue.

[0038] Those 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 of the present disclosure. It is contemplated that elements and features shown or described in connection with one exemplary embodiment of the present disclosure may be combined with other elements and features without departing from the scope of the present disclosure. Similarly, those skilled in the art will appreciate further features and advantages of the present disclosure based on the above-described embodiments of the present disclosure. Thus, the present disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

Claims

1. 1. A loading unit for a circular stapling device, said loading unit comprising: a shell member having an elongated tubular portion; a staple pusher assembly operably disposed within said shell member; a knife pusher assembly operably disposed within the shell member; a trocar assembly including a trocar member operatively disposed within the shell member and movable from an advanced position and a retracted position; a tissue retraction assembly disposed within the shell member between the knife pusher assembly and the trocar assembly, the tissue retraction assembly including a tissue retraction device; A loading unit comprising:

2. The loading unit of claim 1 , wherein the elongated tubular portion of the shell member is between 6 and 12 inches in length.

3. The loading unit of claim 1 , wherein the elongated tubular portion includes an inner portion and an outer portion and defines a cavity between the inner portion and the outer portion.

4. The loading unit of claim 1 , wherein the staple pusher assembly and the knife pusher assembly are operably received within a cavity and are movable between an advanced position and a retracted position.

5. The loading unit of claim 3 , wherein the tissue retraction assembly includes a holder, the holder defining a longitudinal opening and selectively movable along the inner portion of the shell member.

6. The loading unit of claim 5 , wherein the tissue retractor extends through the longitudinal opening of the holder.

7. The loading unit of claim 6 , wherein the tissue retraction device is longitudinally fixed to the holder.

8. 1. A circular stapler, comprising: an adapter assembly configured for operative connection to the actuation assembly; A loading unit, the loading unit comprising: a shell member having an elongated tubular portion; a staple pusher assembly operably disposed within said shell member; a knife pusher assembly operably disposed within the shell member; a trocar assembly including a trocar member operatively disposed within the shell member and movable from an advanced position and a retracted position; a tissue retraction assembly disposed within the shell member between the knife pusher assembly and the trocar assembly, the tissue retraction assembly including a tissue retraction device; A loading unit including A circular stapler comprising:

9. The circular stapler of claim 8, wherein the elongated tubular portion of the shell member is between 6 and 12 inches in length.

10. The circular stapler of claim 8 , wherein the elongated tubular portion includes an inner portion and an outer portion and defines a cavity between the inner and outer walls.

11. The circular stapler of claim 8, wherein the staple pusher assembly and the knife pusher assembly are operably received within a cavity and are movable between advanced and retracted positions.

12. The circular stapler of claim 10, wherein the tissue retracting assembly includes a holder defining a longitudinal opening and selectively movable along the inner portion of the shell member.

13. The circular stapler of claim 12 , wherein the tissue retracting device extends through the longitudinal opening of the holder.

14. The circular stapler of claim 13 , wherein the tissue retraction device is longitudinally fixed relative to the holder.

15. 1. A circular stapling device for forming an anastomosis, said circular stapling device comprising: A loading unit configured to be received within a rectal stump of a patient, the loading unit includes a tissue retraction device configured to be advanced from the loading unit and secured to the rectal stump; the tissue retraction device is further configured to be retracted into the loading unit such that the rectal stump is retracted into the loading unit to shorten the rectal stump. A loading unit; means for clamping, stapling and severing said rectal stump; 1. A circular stapling device comprising:

16. The circular stapling device of claim 15, wherein the rectal stump is configured to be sutured to the tissue retraction device.

17. The circular stapling device of claim 15, wherein the tissue retraction device includes a holder, and advancement of the tissue retraction device causes advancement of the holder.

18. The circular stapling device of claim 17, wherein retraction of the tissue retracting apparatus causes retraction of the holder.

19. The circular stapling device of claim 15, wherein the loading unit further includes a staple cartridge configured to be positioned adjacent to the patient's anus when the rectal stump is pulled into the loading unit.

20. The circular stapling device of claim 15, further comprising an anvil assembly configured to be secured to the colon and secured to the loading unit.

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