The present disclosure relates to a surgical instrument and method for performing anastomosis of tubular body structures, and more particularly to an instrument for joining tubular tissues, for example, during gastrointestinal procedures. 
Surgical stapling devices for applying an annular array of staples or fasteners to tissue are well known in the art.  For example, surgical stapling devices for applying an annular array of staples, as well as devices for completing a surgical anastomosis through the provision of anastomosis rings, are well known in gastric and esophageal surgery, for example in classic or modified gastric reconstruction typically formed in an end to end, end to side, or side to side manner. 
These devices generally include a circular array of fasteners such as staples, anastomosis rings, and the like, while the anvil member includes means for completing the circular anastomosis, typically an array of bucket members that cinch the staples after the staples are expelled from the fastener assembly, or may include a locking member for the anastomosis ring. 
In use, the anvil is positioned within the lumen of an organ such as the stomach, esophagus, or intestine and the tissue is pulled about and around the anvil member and tied off, e.g., by a purse string suture, ring mechanism or the like.  The fastener assembly is then positioned within the opposite end of the lumen and the tissue is pulled about and around the fastener assembly over the staple array and also tied off.  At this point the tissue is positioned between the anvil and the fastener assembly.  The anvil is typically slowly retracted (or advanced) to approximate the two tissue halves prior to deformation of the staples usually by virtue of a wing-nut and worm gear assembly which allows a surgeon to methodically advance the anvil towards the staple array to hold the tissue between the anvil and the fastener assembly.  Many prior art devices also provide a visual indicator to signal the surgeon when the anvil has reached a firing position adjacent the staple or fastener assembly. 
The surgeon then unlocks a safety device deform the staples against the anvil.  As the staples or the fasteners are expelled from the fastener assembly, a circular knife typically follows the application of the staples to excise unwanted tissue at the anastomosis site.  The instrument is then removed from the lumen of the organ. 
The closing mechanisms associated with the prior art stapling or fastening devices typically utilize a complex worm gear arrangement or screw bearing member to approximate the spacing between the anvil and the fastener assembly.  As mentioned above, this requires additional manipulation of the instrument by the surgeon during the surgery, e.g., the surgeon must grasp the device with one hand while rotating the knob or wing-like assembly with the other hand.  As can be appreciated, moving the anvil member the full distance towards the fastener assembly can be a time consuming process during the surgical procedure.  For example, many of the known prior art devices require 15 to 20 full 360° rotations of the knob or wing nut assembly to fully close the instrument in order to fire or expel the staples or fasteners into the tissue. 
As can be appreciated, it would be advantageous to eliminate many of the above steps for performing the circular anastomosis of these tissue structures to expedite the overall surgical procedure.  It would also be extremely advantageous to simplify the overall anastomosis procedure and reduce the level of manual intervention by the surgeon with respect to tying off the tubular ends prior to staple deformation.  Moreover, it would be advantageous to provide an instrument which can perform end-to-end anastomosis deep within a tubular structure, e.g., colon, where known prior art devices cannot reach and the surgeon is forced to perform an gastrotomy and then make an incision within the side of the tubular structure to utilize these prior art devices. 
A need also exists to develop a device which can be useful for low anterior resection of the colon which has proven difficult with a number of prior art devices.  In addition, it would be useful to provide a device where the eversion of the tissue is exterior to the colon which facilitates future repair if needed and reduces the chances of stenosis at the anastomosis site.  It would also be helpful to provide an instrument which reduces the amount of healthy tissue removed from the site during the anastomosis.