Topography of the pelvic autonomic nerves - an anatomical study to facilitate nerve-preserving total mesorectal excision.

INTRODUCTION

Urogenital dysfunction caused by iatrogenic injury to the autonomic nerves persists as a common complication of rectal cancer surgery. This study aims to investigate the relationship between autonomic nerves and the 'holy plane' with the intention of identifying hazardous sites at which urogenital dysfunction may occur.

PATIENTS AND

METHODS

Dissection of the 'holy plane' and preparation of the autonomic nerves were performed on Thiel-embalmed bodies. The morphology of the inferior hypogastric plexus and its distance to nearby reference points was recorded.

RESULTS

In all 28 bodies (13 females, 15 males), we observed that the autonomic nerves were enveloped in parietal pelvic fascia and thereby absent from the 'holy plane' of total mesorectal excision. The midpoint of the inferior hypogastric plexus resided 85 mm from the sacral promontory, and 47 mm from the coccygeal apex. Both distances were significantly longer in men than in women (p < 0.01, p < 0.01). The ureter coursed 11 mm superiorly to the inferior hypogastric plexus. Distal to the ischial spine, it ran 13 mm laterally to the mesorectal fascia. Differences between females and males were not statistically significant (p = 0.32, p = 0.85).

CONCLUSIONS

Pursuit of the 'holy plane' spares the autonomic nerves. Restricted visibility may complicate the identification and sparing of the autonomic nerves, and, thus, requires the meticulous planning and execution of surgery. Contextual, the ureter may act as another landmark for the localisation of the inferior hypogastric plexus, additionally to the already established lateral ligaments of the rectum.