Total mesorectal excision for rectal cancer: the truth lies underneath.

The surgical technique itself has emerged as a crucial factor for local recurrence since the popularization of total mesorectal excision for the treatment of rectal cancer. This procedure is associated with lower local recurrence rates after "curative" surgery compared to traditional dissection of the rectum. The aim is to remove an intact mesorectal envelope from the promontorium down to the pelvic floor by sharp dissection with tumor-free margins and without causing injury to the pelvic nerves. However, the description of total mesorectal excision has been confusing. Moreover, the implication that total excision of all the perirectal fat contained within the perirectal fascia en bloc in all patients with rectal cancer can minimize local recurrence remains contentious. Therefore a critical appraisal of the procedure is required. Nonrandomized clinical studies have shown that total mesorectal excision reduces the local recurrence rate and increases disease-free survival in patients with adenocarcinoma of the middle and distal third of the rectum. Circumferential resection margins of 2 mm or more are associated with a lower local recurrence rate. Additional benefits in local control can be obtained with neoadjuvant treatment. Thus the modern treatment of rectal cancer combining total mesorectal excision with neoadjuvant chemoradiation results in excellent local tumor control. However, it is achieved at the cost of significant functional sequelae and impaired quality of life. The development of therapeutic alternatives that can achieve similar rates of local and distant tumor control without the mortality, morbidity, and functional consequences of radical surgery is a major challenge for colorectal surgeons.