Surgical Anatomy of Pelvic Plexus for Autonomic

Nerve Preserving Operation for Rectal Cancer

Abstract

Detailed dissections were performed on 20 adult cadavers to examine the surgical anatomy of the pelvic autonomic nerve plexus from a lateral view of the pelvis. The pelvic plexus was situated in the upper part of the peritoneal reflection of Douglas' pouch under the pelvic fascia and averaged 3.5 x 2.2 cm in size. A point of intersection was determined on the tangent line (O-Sn) between the bottom of the sacrum and the pubis, and the line (Sn (O-P)) through the bottom of sacrum, that was drawn parallel to the line (O-P) between the promontrium and the pubis. The upper angle of the pelvic plexus, seen from a lateral view, was located in the anterior area between S1 (O-P) and S2 (O-P). The anterior angle of the pelvic plexus was located in the area surrounded by O-S3, O-S4 and S2 (O-P) in men, and by O-S3, O-S5, S2 (O-P) and S3 (O-P) in women. The 4th pelvic splanchnic nerve (S4n) was traced to the direction of the upper margin of the pubis through the 4th pelvic sacral foramen in men and the lower margin of the pubis in women. It was concluded that if the positional relation between rectal cancer and the pelvic plexus becomes clear, total autonomic nerve preserving operation and S4n preserving operation will be performed precisely.