[The mesorectum: improvement and anatomy of a semantic error]

The cancer of the rectum touches 10,000 patients per year in France. Its treatment is mainly surgical. 50% of the treated patients will die of their cancer, either by loco-regional recurrence, or by metastatic disease. The rates of local recurrence vary from 10 to 40%. Heald is first who brought back recurrence rates lower than 4%, results obtained by the only surgical treatment. This treatment included the total exeresis of cellulo-fatty tissue surrounding the rectum, tissue which was baptized mesorectum. The aims of this work is to define and describe this space, and to discuss its Christian name.

The anatomical study carries on the dissection of 2 frozen pelvis of fresh man, one cut transversely on the level of L4, the other half-compartment sagittaly, then defrosted for the dissection.

The mesorectum is defined and its various structures, fascia, vessels and nerves, are detailed.

The mesorectum is an anatomical and surgical structure individualisable. Its recognition and its importance were born from the understanding of the fascia and the rectal anatomy. Its exeresis decreases the rate of the local recurrence (18). The technique of exeresis of the mesorectum must be validated, standardized, in order to be reproducible in the treatment of the cancer of the rectum.