Studies of the vascular anatomy of the mesorectum support the concept of the total mesorectal excision

The relation between the mesorectal vessels and the mesorectal fascia needs to be clarified, as a total mesorectal excision (TME) probably derives its advantage from the fact that the visceral or mesorectal fascia can be regarded as a “tumor-tight packaging” and does not contain anatomically preformed perforations. The purpose of this investigation was to study both rectal arterial supply and vascular distribution pattern within the mesorectum. The arterial supply to the rectum was studied with the injection technique in 12 porcine and 28 human TME specimens. We stain-marked 12 porcine and 15 human specimens. Thirteen human specimens were angiographed after filling their arterial bed with a radio-opaque substance. The superior rectal artery is the main rectal artery. Terminal branches extend downwards and forward around the rectum to the level of the levator and muscle. The superior rectal artery and vein were found to be enclosed in a fibrous sheath. The main mesorectal vessels do not penetrate the mesorectal fascia. This study supports the hypothesis of bilateral somatic and one central visceral compartment in the pelvis and implies the absolute necessity of tumor removal within an intact mesorectal fascia.