Anterior resection with total mesorectal excision (TME) is the standard procedure for mid and low rectal cancers . A colo-rectal anastomosis under peritoneal reflection is, most of the time, protected by a temporary loop stoma to decrease the risk and severity of anastomotic morbidity. This stoma, which is intended to be temporary, appears to be permanent in 6 to 32% of cases in the literature. The main risk factor being anastomotic leakage. Two major risk factors for anastomotic leakage after colorectal surgery are " male sex " and " Body mass index ", which are responsible of a higher anatomical difficulty (Narrow pelvis and bulky mesorectal fat) Therefore, the objective of this study is to look for a statistical link between permanent stoma and intraoperative difficulty represented by pelvic anatomical constraints.

Anterior resection with total mesorectal excision (TME) is the standard procedure for mid and low rectal cancers . A colo-rectal anastomosis under peritoneal reflection is, most of the time, protected by a temporary loop stoma to decrease the risk and severity of anastomotic morbidity. This stoma, which is intended to be temporary, appears to be permanent in 6 to 32% of cases in the literature. The main risk factor being anastomotic leakage. Two major risk factors for anastomotic leakage after colorectal surgery are " male sex " and " Body mass index ", which are responsible of a higher anatomical difficulty (Narrow pelvis and bulky mesorectal fat) Studies focused on surgical difficulties usually evaluated criteria such as, total surgery duration, blood loss or surgeon's subjective evaluation. The investigators of this retrospective study hypothesize that when a stoma,primarily intended to be temporary, is not reversed after a long (2 years) post operative delay, it all comes to surgical difficulties and that these surgical difficulties are essentially represented by anatomical constraints. Therefore, the objective of this study is to look for a statistical link between permanent stoma and intraoperative difficulty represented by pelvic anatomical constraints.

Inclusion Criteria:

• Adult patients who underwent a sphincter saving resection for low rectal cancer between January 2019 and December 2017.

Exclusion Criteria:

• Minor patients.
• Patients who have undergone a cancer proctectomy with no restoration of continuity expected.
• Patients who did not have total Mesorectal excision

Adult patients who underwent a cancer proctectomy with sphincter conservation