The patient is placed in the appropriate positioning specific to the operative approach (open, laparoscopic, or robotic). However, despite the approach a few key principles will facilitate fashioning the anastomosis:

The splenic flexure and the distal large bowel are fully mobilized along with the rectum as described elsewhere in this chapter. For there to be enough proximal colon to fashion a tension-free anastomosis, a high ligation of the inferior mesenteric artery and inferior mesenteric vein is usually necessary. Rectal resection with total or partial mesorectal excision, as indicated by the location of the tumor, is performed. The posterior dissection plane is developed in an avascular areolar tissue plane all the way to the pelvic floor. The dissection plane can be followed around the pelvis to the lateral peritoneal attachments. The attachments are incised to release the rectum. For mid to low rectal tumors, the anterior lateral ligaments containing the middle hemorrhoid vessel are divided with electrocautery at the sidewall of the pelvis to remove all of the mesenteric fat.

The distal resection margin is chosen and the mesorectal fat is circumferentially cleared off. A linear stapler is fired across the rectum; this can be laparoscopically done using an Echelon® (Ethicon, Cincinnati, OH, USA) or Endo GIA® (Ethicon, Cincinnati, OH, USA) or in an open procedure using a number of stapling devices including the Contour curved cutter® (Ethicon, Cincinnati, OH, USA) or TA stapler. It is imperative to ensure that the rectum has been completely stapled and closed (Fig. 16.1).

This technique is the standard method to construct low colorectal anastomoses. Since the advent of the circular end-to-end stapler and the description of the EEA anastomosis
in 1979, this technique has evolved from a double purse-string EEA anastomosis to a double-stapled EEA anastomosis (9,10).