The benefits of total mesorectal excision are due to the complete excision
of the mesorectum with preservation of the pelvic autonomic nerve plexuses,
the hypogastric nerves and nervi erigentes. Several important structures a
re incompletely seen at operation, and cadaveric dissection of an intact lo
wer trunk and a sagittally hemisected pelvis is a valuable exercise in demo
nstrating them. A method for dissection is described which illustrates the
key anatomical points.