Vascular organization in the mesorectum: angiography of rectal resection specimens

The technical advances in rectal cancer surgery are known as the total meso rectal excision. The resection in an anatomically defined plane under direc t vision and with sharp dissection distinguishes it conventional rectal sur gery. The result must be a complete mesorectum without deep gouges, We perf ormed specimen angiography to confirm completeness of the removed mesorectu m, Thirteen total mesorectal excision specimens were examined by angiograph y after continence-preserving resection of rectal carcinoma, In 11 of the 1 3 cases the vascular supply was exclusively via the superior rectal artery. In two cases with hypoplastic left terminating branches of the superior re ctal artery there was additional perfusion via a caudally ascending vessel or via smaller vessels connected laterally. In all specimens both arterial supply and venous outflow were located within the mesorectal fascial sheath . There was no radio-opaque substance leaking from the mesorectal surface i n the case of a complete mesorectal specimen. Tiny vascular branches runnin g laterally occurred in 7 of the 13 cases. We found no larger vascular conn ections branching off in the lateral direction. The rectal blood supply com es almost exclusively through the superior rectal vessels. Thus the fascia covering the mesorectum forms, as far as rectal vascularization is concerne d, a closed compartment. The mesorectal vessels are enclosed in the fibrous avascular mesorectal fascia. They run close above the fascia. In the case of an incomplete mesorectal excision the specimen angiography shows a stain leaking from the mesorectal fascia. Our method can be used to confirm the completeness of the removed mesorectum.