[Anatomical basis of autonomic nerve-preserving radical resection for rectal cancer]

To clarify anatomical basis of autonomic nerve-preserving radical resection for rectal cancer.

Of 10 cadavers, 4 were male and 2 female. Four had hemisected pelvis in the mid-sagittal plane without damaging the retrorectal anatomy. All stages of each dissection were recorded photographically.

Hypogastric nerves were identified. The superior hypogastric plexus is the direct extension of the aortic plexus below the aortic bifurcation. It lies immediately behind the peritoneum and descends over the anterior surface of the 5th lumbar vertebra in the retroperitoneal tissue. The superior hypogastric plexus ends by bifurcating into the right and left hypogastric nerves. The two hypogastric nerves diverge from each other at about the level of the sacral promontory and run down and forward along the walls of the pelvis in the lamina of the pelvic fascia closest to the peritoneum. Both of them are strong fibres with white-grey and reticular appearance and well located just below and close to the aortic bifurcation. And after bifurcation each of them also gives rise to several branches. But it is difficult to identify the pelvic splanchnic nerves in complete samples. In mid-sagitted samples they take origin from the second to fourth sacral ventral rami just after the sacral nerves have emerged from the pelvic sacral foramina. They always form plexus at the lateral ligament and are crossed by middle rectal artery.

It is not very difficult to preserve the hypogastric nerves to spare functions in resection for rectal cancer to the anatomical knowledge of the pelvic autonomic nerves. When the pelvic splanchnic nerves are to be preserved, dissection must be cautious at the level of the lateral ligment on the side of nerve-preservation. The operation should be performed near the rectum as close as possible to achieve functional preservation.