Severing the left ureter
This can be avoided by dissecting in the correct layers and carefully mobilizing only the mesosigmoid from laterally. Furthermore, identify the ureter but do not expose it extensively because this might injure the nerve plexus in this region. In our department we also do not pass a tape around it.
Bleeding from the sacral plexus
This very serious complication, which quickly can become life-threatening, is avoided by continuing the dissection only in the areolar layer of the mesorectum. If bleeding should occur, it is usually impossible to control it by suture ligatures (exception: Hemorrhage after injury to the external or internal iliac artery). In such a situation, early packing of the local field for several minutes while the blood coagulation is still stable is the better solution. Prolonged compression alone can safely control at least minor bleeding. If extensive bleeding does occur, it is recommended to complete the rectal resection under temporary compression, transect the rectum distally with the stapler, pack the lesser pelvis and, if necessary, exteriorize the stoma along the lines of a Hartmann procedure. Once the patient has stabilized and the packing can be removed later (e.g., after 2 days), the anastomosis could be constructed or deferred to a later date, depending on the condition of the patient.
Anastomotic leakage
The anastomosis should be constructed under direct view, and when employing a circular stapler its anvil should be secured very carefully with a purse-string suture. If there is a leak oversaw it directly, and for safety reasons construct a diverting stoma.