The main instrument used is called a circular anus dilator. This dilator reduces the prolapse of the anus skin and parts of the anus mucous membrane. After the obturator is removed, the prolapsed membrane falls into the dilator lumen.
Another instrument is then inserted through the dilator called a purse-string suture anoscope. This instrument will push the prolapsed mucous back against the rectum wall 270 degrees around. The mucous membrane that comes through the anoscope window can be contained in a suture that includes only mucous membrane. By rotating theinstrument it is possible to suture the entire rectum circumference in a purse-string suture.
The hemorrhoidal circular stapler is then opened to its maximum position, and inserted through the dilator. It is positioned proximal to the purse-string suture. The ends of the suture are knotted externally.
With moderate traction on the suture, a simple maneuver draws the prolapsed membrane into the circular stapling instrument. The instrument is tightened, and then staples the prolapse. They will generally keep the instrument in the closed position for 30 seconds before firing, and 20 seconds after firing to act as a tamponade, which may help promote hemostasis.
When the stapler is fired, it releases a double staggered row of titanium staples into the tissue. A circular knife then excises the extra tissue. A circumferential column of mucosa is removed from the upper rectum canal. Finally, the staples are examined through the anoscope to check for bleeding. If bleeding occurs, additional absorbable sutures may sometimes be placed.