[Rectal carcinoma. Optimizing therapy by knowledge of anatomy with special reference to the mesorectum].

The connective tissue spaces of the pelvis and pelvic floor originate from an urogenital and perirectal mesenchymal cell complex, which can be clearly discerned. In the adult, the final compartments, which arise from these distinct tissue complexes, are still functionally separated. The perirectal tissue gives rise to the rectal fascia or rectal adventitia, also known as mesorectum. The connective tissue space between rectal and parietal pelvic fascia can be dissected as a plane free of vessels and nerves. Surgical dissection along this plane with complete mesorectum excision results in reliable excision of all relevant lymphatic pathways with extensive preservation of continence and sexual function.